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Sample records for aromatase inhibitor sensitivity

  1. Update on Aromatase Inhibitors

    Directory of Open Access Journals (Sweden)

    Seifert-Klauss V

    2015-01-01

    Full Text Available Aromatase inhibitors (AI block the last phase of estrogen production in many types of tissues which express the enzym aromatase, among them muscle, liver, adrenal, brain and fat. The enzyme catalyzes the last step of the biosynthesis of the estrogens, i. e. the aromatisation of testosterone to estradiol and of androstendion to estrone. Aromatase is localized in the membrane of the endoplasmatic reticulum and is also produced in the placenta and the gonads. Mutations in the gene CYP19A1, which codes for aromatase, can lead either to lack or excess of aromatase. Gene polymorphisms also influence the amount of bioavailable estrogen and bone density.br Indications: AI are approved for the treatment of postmenopausal women with hormone receptor positive breast cancer, both in the adjuvant setting as well as after recurrence and in progressive disease. In premenopausal and in perimenopausal women AI cause an increased sensitivity of the ovaries to follicle stimulating hormone (FSH and can thereby lead to a boosted estrogen answer – this effect is particularly pronounced in early perimenopausal women – so that these situations demand a combination with GnRH-analogue if AI treatment is to be initiated. Alternatively, tamoxifene may be used in premenopausal patients, with or without GnRH analogues. Treatment of premenopausal patients with hormone receptor positive breast cancer with aromatase inhibiting therapy alone constitutes an absolute contraindication. Aromatase inhibitors do not lead to estrogen receptor downregulation or block the receptor such as tamoxifene. An exceptional application is the application in reproductive medicine in women who do not have hormone receptor positive breast cancer: because of the higher sensitivity induced by AI-co-therapy, FSH-doses and -costs for assisted reproduction are reduced, and ovarian hyperstimulation syndrome (OHSS may be avoided. For premenopausal diseases which are said to be positively affected by

  2. Molecular Docking of Aromatase Inhibitors

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    Virapong Prachayasittikul

    2011-04-01

    Full Text Available Aromatase is an enzyme that plays a critical role in the development of estrogen receptor positive breast cancer. As aromatase catalyzes the aromatization of androstenedione to estrone, a naturally occurring estrogen, it is a promising drug target for therapeutic management. The undesirable effects found in aromatase inhibitors (AIs that are in clinical use necessitate the discovery of novel AIs with higher selectivity, less toxicity and improving potency. In this study, we elucidate the binding mode of all three generations of AI drugs to the crystal structure of aromatase by means of molecular docking. It was demonstrated that the docking protocol could reliably reproduce the interaction of aromatase with its substrate with an RMSD of 1.350 Å. The docking study revealed that polar (D309, T310, S478 and M374, aromatic (F134, F221 and W224 and non-polar (A306, A307, V370, L372 and L477 residues were important for interacting with the AIs. The insights gained from the study herein have great potential for the design of novel AIs.

  3. Natural Products as Aromatase Inhibitors

    OpenAIRE

    Balunas, Marcy J.; Su, Bin; Brueggemeier, Robert W.; Kinghorn, A. Douglas

    2008-01-01

    With the clinical success of several synthetic aromatase inhibitors (AIs) in the treatment of postmenopausal estrogen receptor-positive breast cancer, researchers have also been investigating also the potential of natural products as AIs. Natural products from terrestrial and marine organisms provide a chemically diverse array of compounds not always available through current synthetic chemistry techniques. Natural products that have been used traditionally for nutritional or medicinal purpos...

  4. Managing arthralgia in a postmenopausal woman taking an aromatase inhibitor for hormone-sensitive early breast cancer: a case study

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    Bryce J

    2012-03-01

    Full Text Available Jane Bryce1, Martina Bauer2, Peyman Hadji21National Cancer Institute, Naples, Italy; 2Philipps University of Marburg, Marburg, GermanyBackground: In order to reduce the risk of recurrence, adjuvant treatment with an aromatase inhibitor (AI is recommended for postmenopausal women following surgery for hormone receptor-positive breast cancer. AIs are associated with improved disease-free survival compared with tamoxifen. The adverse events associated with AIs resemble those of menopause, such as bone density loss and musculoskeletal symptoms.Purpose: We examine the case of a postmenopausal woman who was prescribed anastrozole, a nonsteroidal AI, as adjuvant therapy following surgery for estrogen and progesterone receptor-positive (ER and PgR+ breast cancer.Methods and sample: A 58-year-old postmenopausal woman diagnosed with ER and PgR+ breast cancer was prescribed anastrozole as adjuvant therapy following a right-inferior quadrantectomy. After experiencing joint pain and stiffness, she was prescribed paracetamol and a topical nonsteroidal anti-inflammatory drug. She was also counseled on nonpharmacological interventions. However, she continued to experience symptoms, and reported that she was not taking anastrozole regularly.Results: The case study patient ultimately found relief by switching to letrozole, another aromatase inhibitor. This approach is supported by recent studies examining the benefits of switching strategies between aromatase inhibitors in order to relieve symptoms of arthralgia/myalgia.Conclusions: Both adherence and strategies for managing aromatase inhibitor-associated arthralgia are key to deriving maximal clinical benefit from AI therapy. Switching from one aromatase inhibitor to another may provide a viable option in managing adverse events and enhancing adherence to medication.Keywords: adherence, anastrozole, aromatase inhibitor, arthralgia, breast cancer, letrozole

  5. Aromatase inhibitors in the treatment of endometriosis.

    Science.gov (United States)

    Słopień, Radosław; Męczekalski, Błażej

    2016-03-01

    Endometriosis is a chronic inflammatory condition in which foci of endometrial tissue grow outside of the uterine cavity. Endometriosis was estimated to affect 176 million women of childbearing potential all over the world in 2010. The presence of extrauterine endometrial tissue is associated with pain and infertility. Typical symptoms of endometriosis include dysmenorrhoea, dyspareunia, heavy menstrual periods (menorrhagia), pelvic pain that is not related to menstrual cycles, dysuria, and chronic fatigue. Medical treatments for endometriosis include combined oral contraceptive pills, danazol, gestrinone, medroxyprogesterone acetate, and gonadotropin-releasing hormone agonists (aGnRHs). A new class of medications called aromatase inhibitors has been identified in recent years as potential therapeutic agents for endometriosis. This article provides general information about aromatase inhibitors, their use in gynaecology, and their adverse effects. In particular, the paper discusses the use of aromatase inhibitors in the treatment of endometriosis in postmenopausal women. Unlike oral contraceptives, gestagens, aGnRHs, and danazol, which suppress ovarian oestrogen synthesis, aromatase inhibitors inhibit mainly extra-ovarian synthesis of oestrogens. Therefore, the use of aromatase inhibitors seems to be particularly relevant in older patients, as most of the body's oestrogen is produced outside the ovaries after menopause. The paper discusses also the use of aromatase inhibitors in the treatment of pain associated with endometriosis and infertility caused by endometriosis. PMID:27095958

  6. Aromatase inhibitors in the treatment of endometriosis

    Science.gov (United States)

    Męczekalski, Błażej

    2016-01-01

    Endometriosis is a chronic inflammatory condition in which foci of endometrial tissue grow outside of the uterine cavity. Endometriosis was estimated to affect 176 million women of childbearing potential all over the world in 2010. The presence of extrauterine endometrial tissue is associated with pain and infertility. Typical symptoms of endometriosis include dysmenorrhoea, dyspareunia, heavy menstrual periods (menorrhagia), pelvic pain that is not related to menstrual cycles, dysuria, and chronic fatigue. Medical treatments for endometriosis include combined oral contraceptive pills, danazol, gestrinone, medroxyprogesterone acetate, and gonadotropin-releasing hormone agonists (aGnRHs). A new class of medications called aromatase inhibitors has been identified in recent years as potential therapeutic agents for endometriosis. This article provides general information about aromatase inhibitors, their use in gynaecology, and their adverse effects. In particular, the paper discusses the use of aromatase inhibitors in the treatment of endometriosis in postmenopausal women. Unlike oral contraceptives, gestagens, aGnRHs, and danazol, which suppress ovarian oestrogen synthesis, aromatase inhibitors inhibit mainly extra-ovarian synthesis of oestrogens. Therefore, the use of aromatase inhibitors seems to be particularly relevant in older patients, as most of the body's oestrogen is produced outside the ovaries after menopause. The paper discusses also the use of aromatase inhibitors in the treatment of pain associated with endometriosis and infertility caused by endometriosis. PMID:27095958

  7. Aromatase inhibitor strategies in metastatic breast cancer

    Directory of Open Access Journals (Sweden)

    Heather L McArthur

    2009-07-01

    Full Text Available Heather L McArthur, Patrick G MorrisBreast Cancer Medicine Service, Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, NY, USAAbstract: Despite ongoing therapeutic innovations, metastatic breast cancer (MBC remains a treatable but incurable disease. In the developed world, a diagnosis of MBC without a preceding diagnosis of early stage disease is a rare event. However, approximately one-third of women with early stage breast cancer ultimately experience a distant recurrence. Because the majority of breast cancers express estrogen and/or progesterone receptors and are accordingly considered hormone-sensitive, therapeutic strategies that interfere with hormone-mediated tumorigenesis have been a cornerstone of the breast cancer management paradigm for decades. Historically, the selective estrogen receptor modulator tamoxifen has been the most extensively studied and widely used hormone maneuver in breast cancer. However, a recent therapeutic innovation, namely the successful development of third-generation aromatase inhibitors (AIs, has had a dramatic impact on the treatment paradigm for women with hormone-sensitive MBC. Because of the demonstrated efficacy in postmenopausal breast cancer patients, the generally favorable side-effect profile, and the convenience of oral administration, AIs are now in widespread clinical use. Currently, there are three clinically available third-generation AIs: two reversible, nonsteroidal AIs, letrozole and anastrozole; and one irreversible, steroidal AI, exemestane. All three agents are at least as efficacious as tamoxifen as monotherapy for postmenopausal women with hormone-sensitive MBC. Current clinical research aims to improve upon existing strategies by evaluating AIs in combination with systemic chemotherapy regimens and/or novel targeted agents. It is hoped that these therapeutic innovations will lead to ongoing improvements in quality of life parameters and ideally survival for women

  8. Aromatase inhibitors and anti-synthetase syndrome.

    Science.gov (United States)

    Mascella, Fabio; Gianni, Lorenzo; Affatato, Alessandra; Fantini, Manuela

    2016-09-01

    Adjuvant therapy in postmenopausal women with endocrine-responsive breast cancer (BC) is actually centered on the use of anti-aromatase inhibitors (AI). Several reports, however, are emerging in literature associating the use of this drugs to rheumatic disorders. This case report describes the first case of anti-synthetase syndrome diagnosis after treatment with anti-estrogen agents in a patient with pre-existing rheumatoid arthritis. PMID:27225465

  9. Aromatase inhibitors in men: effects and therapeutic options

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    de Jong Frank H

    2011-06-01

    Full Text Available Abstract Aromatase inhibitors effectively delay epiphysial maturation in boys and improve testosterone levels in adult men Therefore, aromatase inhibitors may be used to increase adult height in boys with gonadotropin-independent precocious puberty, idiopathic short stature and constitutional delay of puberty. Long-term efficacy and safety of the use of aromatase inhibitors has not yet been established in males, however, and their routine use is therefore not yet recommended.

  10. The effect of aromatase inhibitors on bone metabolism

    DEFF Research Database (Denmark)

    Folkestad, Lars; Bjarnason, Nina H; Bjerregaard, Jon Kroll;

    2009-01-01

    Aromatase inhibitors increase the disease-free survival in patients with receptor-positive breast cancer. Aromatase is a cytochrome P450 enzyme complex catalysing the conversion of androgens to oestrogens. These properties cause a significant increase in bone loss. In this MiniReview, we present ...... in comparison with tamoxifen. We conclude that treatment with aromatase inhibitors leads to an increased bone loss and thus an increase in the risk of fractures in women with breast cancer.......Aromatase inhibitors increase the disease-free survival in patients with receptor-positive breast cancer. Aromatase is a cytochrome P450 enzyme complex catalysing the conversion of androgens to oestrogens. These properties cause a significant increase in bone loss. In this MiniReview, we present...... data from the aromatase inhibitor studies and the studies designed to investigate aromatase inhibitor effect on bone metabolism. At the cellular level, oestrogen has profound effects on both osteoblasts and osteoclasts. Oestrogen decreases the osteoblastic production of resorptive cytokines...

  11. Committee Opinion No. 663: Aromatase Inhibitors in Gynecologic Practice.

    Science.gov (United States)

    2016-06-01

    Aromatase inhibitors have been used for the treatment of breast cancer, ovulation induction, endometriosis, and other estrogen-modulated conditions. For women with breast cancer, bone mineral density screening is recommended with long-term aromatase inhibitor use because of risk of osteoporosis due to estrogen deficiency. Based on long-term adverse effects and complication safety data, when compared with tamoxifen, aromatase inhibitors are associated with a reduced incidence of thrombosis, endometrial cancer, and vaginal bleeding. For women with polycystic ovary syndrome and a body mass index greater than 30, letrozole should be considered as first-line therapy for ovulation induction because of the increased live birth rate compared with clomiphene citrate. Lifestyle changes that result in weight loss should be strongly encouraged. Aromatase inhibitors are a promising therapeutic option that may be helpful for the management of endometriosis-associated pain in combination therapy with progestins. PMID:27214191

  12. Committee Opinion No. 663 Summary: Aromatase Inhibitors in Gynecologic Practice.

    Science.gov (United States)

    2016-06-01

    Aromatase inhibitors have been used for the treatment of breast cancer, ovulation induction, endometriosis, and other estrogen-modulated conditions. For women with breast cancer, bone mineral density screening is recommended with long-term aromatase inhibitor use because of risk of osteoporosis due to estrogen deficiency. Based on long-term adverse effects and complication safety data, when compared with tamoxifen, aromatase inhibitors are associated with a reduced incidence of thrombosis, endometrial cancer, and vaginal bleeding. For women with polycystic ovary syndrome and a body mass index greater than 30, letrozole should be considered as first-line therapy for ovulation induction because of the increased live birth rate compared with clomiphene citrate. Lifestyle changes that result in weight loss should be strongly encouraged. Aromatase inhibitors are a promising therapeutic option that may be helpful for the management of endometriosis-associated pain in combination therapy with progestins. PMID:27214185

  13. Aromatase inhibitors and antiepileptic drugs: a computational systems biology analysis

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    Mustata Gabriela

    2011-06-01

    Full Text Available Abstract Background The present study compares antiepileptic drugs and aromatase (CYP19 inhibitors for chemical and structural similarity. Human aromatase is well known as an important pharmacological target in anti-breast cancer therapy, but recent research demonstrates its role in epileptic seizures, as well. The current antiepileptic treatment methods cause severe side effects that endanger patient health and often preclude continued use. As a result, less toxic and more tolerable antiepileptic drugs (AEDs are needed, especially since every individual responds differently to given treatment options. Methods Through a pharmacophore search, this study shows that a model previously designed to search for new classes of aromatase inhibitors is able to identify antiepileptic drugs from the set of drugs approved by the Food and Drug Administration. Chemical and structural similarity analyses were performed using five potent AIs, and these studies returned a set of AEDs that the model identifies as hits. Results The pharmacophore model returned 73% (19 out of 26 of the drugs used specifically to treat epilepsy and approximately 82% (51 out of 62 of the compounds with anticonvulsant properties. Therefore, this study supports the possibility of identifying AEDs with a pharmacophore model that had originally been designed to identify new classes of aromatase inhibitors. Potential candidates for anticonvulsant therapy identified in this manner are also reported. Additionally, the chemical and structural similarity between antiepileptic compounds and aromatase inhibitors is proved using similarity analyses. Conclusions This study demonstrates that a pharmacophore search using a model based on aromatase inhibition and the enzyme's structural features can be used to screen for new candidates for antiepileptic therapy. In fact, potent aromatase inhibitors and current antiepileptic compounds display significant - over 70% - chemical and structural similarity

  14. Aromatase inhibitors in stimulated IVF cycles

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    Tournaye Herman

    2011-06-01

    Full Text Available Abstract Aromatase inhibitors have been introduced as a new treatment modality that could challenge clomiphene citrate as an ovulation induction regiment in patients with PCOS. Although several randomized trials have been conducted regarding their use as ovulation induction agents, only few trials are available regarding their efficacy in IVF stimulated cycles. Current available evidence support that letrozole may have a promising role in stimulated IVF cycles, either when administered during the follicular phase for ovarian stimulation. Especially for women with poor ovarian response, letrozole appears to have the potential to increase clinical pregnancy rates when combined with gonadotropins, whereas at the same time reduces the total gonadotropin dose required for ovarian stimulation. However, given that in all of the trials letrozole has been administered in GnRH antagonist cycles, it is intriguing to test in the future how it may perform when used in GnRH agonist cycles. Finally administration of letrozole during luteal phase in IVF cycles offers another treatment modality for patients at high risk for OHSS taking into account that it drastically reduces estradiol levels

  15. Aromatase inhibitors for subfertile women with polycystic ovary syndrome (Review)

    NARCIS (Netherlands)

    Franik, S.; Kremer, J.A.M.; Nelen, W.L.D.M.; Farquhar, C.

    2014-01-01

    BACKGROUND: Polycystic ovary syndrome (PCOS) is the most common cause of infrequent periods (oligomenorrhoea) and absence of periods (amenorrhoea). It affects about 4% to 8% of women worldwide and often leads to anovulatory subfertility. Aromatase inhibitors (AIs) are a novel class of drugs that wer

  16. Which patients benefit most from adjuvant aromatase inhibitors?

    DEFF Research Database (Denmark)

    Viale, G; Regan, M M; Dell'Orto, P;

    2011-01-01

    On average, aromatase inhibitors are better than tamoxifen when used as initial or sequential therapy for postmenopausal women with endocrine-responsive early breast cancer. Because there may be contraindications to their use based on side-effects or cost, we investigated subgroups in which...

  17. Aromatase inhibitors for subfertile women with polycystic ovary syndrome (Review)

    OpenAIRE

    Franik, S.; Kremer, J.A.M.; Nelen, W.L.D.M.; Farquhar, C

    2014-01-01

    BACKGROUND: Polycystic ovary syndrome (PCOS) is the most common cause of infrequent periods (oligomenorrhoea) and absence of periods (amenorrhoea). It affects about 4% to 8% of women worldwide and often leads to anovulatory subfertility. Aromatase inhibitors (AIs) are a novel class of drugs that were introduced for ovulation induction in 2001. Over the last ten years clinical trials have reached differing conclusions as to whether the AI letrozole is at least as effective as the first-line tr...

  18. Aromatase inhibitors in the treatment of deep endometriosis

    Directory of Open Access Journals (Sweden)

    Simone Ferrero

    2009-09-01

    Full Text Available Recent case reports and pilot studies suggested that aromatase inhibitors might be effective in treating pain symptoms related to the presence of endometriosis. We present the case of a 32-year-old woman who suffered dysmenorrhea, dyspareunia, chronic pelvic pain, and dyschezia caused by rectovaginal endometriosis. Pain symptoms recurred after treatment with the oral contraceptive pill; the patient refused surgery. Therefore a double-drug regimen including letrozole (2.5 mg/day and norethisterone acetate (2.5 mg/day was offered to the patient. The scheduled length of treatment was six months. This double-drug regimen determined a quick and significant improvement in all pain symptoms. During treatment, the patient complained mild arthralgia. After the interruption of treatment, pain symptoms quickly recurred and at 6-month follow-up their intensity was similar to baseline values. Operative laparoscopy was performed, the presence of rectovaginal endometriosis was confirmed and all visible endometriotic lesions were excised. Aromatase inhibitors might be offered when pain symptoms caused by endometriosis persist during the administration of other hormonal therapies and the patient refuses surgery. However, women must be informed that these drugs determine only a temporary relief of pain symptoms and might cause adverse effects (such as arthralgia.

  19. Developing steroidal aromatase inhibitors-an effective armament to win the battle against breast cancer.

    Science.gov (United States)

    Yadav, Mange Ram; Barmade, Mahesh A; Tamboli, Riyaj S; Murumkar, Prashant R

    2015-11-13

    Breast cancer, an emerging disease among the women population, occurs due to overexpression of estrogens. The enzyme aromatase plays a key rate limiting role in the biosynthesis of estrogens. Certain clinical advantages of the use of exemestane, a steroidal aromatase inhibitor over non-steroidal aromatase inhibitors have drawn the attention of researchers for the development of novel steroidal aromatase inhibitors.The current review is a humble attempt to compile the reports by various researchers till date on the synthesis of steroidal aromatase inhibitors. It has been tried to encompass the structural modifications carried out by various researchers in the steroid ring system by taking up the functional group modifications on rings A, B, ring A/B junction, ring-D, ring modifications, bridged derivatives and heterocyclic ring-fused derivatives in a systematic way.

  20. Potential role of aromatase inhibitors in the treatment of endometriosis

    Directory of Open Access Journals (Sweden)

    Abu Hashim H

    2014-07-01

    Full Text Available Hatem Abu HashimDepartment of Obstetrics and Gynecology, Faculty of Medicine, Mansoura University, Mansoura, EgyptAbstract: Endometriosis is an estrogen-dependent chronic inflammatory disease affecting 5%–10% of reproductive-age women, with a prevalence of 5%–50% in infertile women and >33% of women with chronic pelvic pain. Third-generation aromatase inhibitors (AIs are approved adjuvants for the treatment of estrogen receptor-positive breast cancer. Molecular studies have revealed the presence of aromatase P450, the key enzyme in the biosynthesis of ovarian estradiol, inside the endometriotic tissue, indicating local synthesis of estradiol. Thereby, AIs represent an appealing medical option for the management of different aspects of this enigmatic disease, especially pelvic pain and infertility. Accordingly, this review aims to evaluate the potential role of AIs in the treatment of endometriosis-associated symptoms, mainly pain and infertility. Notably, several studies have demonstrated that the combination of AIs with conventional therapy as oral contraceptive pills, progestins, or gonadotropin-releasing hormone analogs can be used to control endometriosis-associated pain and pain recurrence in premenopausal women, particularly those with pain due to rectovaginal endometriosis refractory to other medical or surgical treatment. Some case reports have shown promising results in the treatment of postmenopausal endometriosis as first-line treatment, when surgery is contraindicated, or as second-line treatment in the case of postoperative recurrence. Third-generation AIs, especially letrozole, have challenged clomiphene citrate as an ovulation-induction agent in patients with polycystic ovary syndrome and in cases of unexplained infertility. However, few studies are available regarding the use of AIs to treat endometriosis-associated infertility. Therefore, larger multicenter randomized trials using AIs for the treatment of endometriosis

  1. Use of Network Inference to Unravel the Mechanisms of Action and Specificity of Aromatase Inhibitors

    Science.gov (United States)

    The vertebrate hypothalamus-pituitary-gonadal (HPG) axis is controlled through various feedback mechanisms in order to maintain a dynamic homeostasis during changing environmental conditions, including exposure to chemical stressors. In this study, three aromatase inhibitors, fad...

  2. A feasibility study of a Nordic walking intervention for women experiencing aromatase inhibitor associated arthralgia

    OpenAIRE

    Fields, Jo

    2015-01-01

    Background: Women taking AIs (Aromatase Inhibitors) as treatment for breast cancer commonly experience joint pain and stiffness (aromatase inhibitor associated arthralgia; AIAA) which can lead to early discontinuation of treatment. Exercise is often recommended and there is preliminary evidence it might prove helpful. Nordic Walking is a popular form of exercise in women with breast cancer, and based on a biopsychosocial model, could provide additional benefits over normal walking alone. Ther...

  3. Bilateral De Quervain Syndrome after Aromatase Inhibitor Administration: A Case Report and Review of the Literature

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    Konstantinos Papadimitriou

    2012-01-01

    Full Text Available Aromatase inhibitors are widely used as one of the main treatment options of both early and advanced hormone receptor-positive breast cancer in postmenopausal women. Unfortunately, musculoskeletal symptoms are often presented in patients treated with aromatase inhibitors (AIs, and, although the pathogenesis is unknown, postulated mechanisms have been described. Herein, to our knowledge, we present the first report of bilateral De Quervain syndrome related with AIs therapy with a review of the relevant literature.

  4. Aromatase Inhibitor-Induced Erythrocytosis in a Patient Undergoing Hormonal Treatment for Breast Cancer

    Directory of Open Access Journals (Sweden)

    Sri Lakshmi Hyndavi Yeruva

    2015-01-01

    Full Text Available Aromatase inhibitors (AIs are most commonly used for breast cancer patients with hormone receptor positive disease. Although the side effect profile of aromatase inhibitors is well known, including common side effects like arthralgia, bone pain, arthritis, hot flashes, and more serious problems like osteoporosis, we present a case of an uncommon side effect of these medications. We report the case of a postmenopausal woman on adjuvant hormonal therapy with anastrozole after completing definitive therapy for stage IIIB estrogen receptor-positive breast cancer, who was referred to hematology service for evaluation of persistent erythrocytosis. Primary and known secondary causes of polycythemia were ruled out. On further evaluation, we found that her erythrocytosis began after initiation of anastrozole and resolved after it was discontinued. We discuss the pathophysiology of aromatase inhibitor-induced erythrocytosis and reference of similar cases reported in the literature.

  5. A Study to Evaluate Genetic Predictors of Aromatase Inhibitor Musculoskeletal Symptoms (AIMSS) | Division of Cancer Prevention

    Science.gov (United States)

    E1Z11 is a study to determine whether certain genetic information can predict which breast cancer patients will discontinue treatment with AIs due to the development of musculoskeletal symptoms (MSS). Women with stage 1-111 breast cancer who are prescribed the aromatase inhibitor anastrozole as treatment may join. |

  6. Direct Effects, Compensation, and Recovery in Female Fathead Minnows Exposed to a Model Aromatase Inhibitor

    Science.gov (United States)

    The paper reports on the effects of a model aromatase inhibitor, fadrozole, on molecular and biochemical endpoints within the fathead minnow reproductive axis. Unlike previous studies, this work incorporated extensive time-course characterization over the course of an 8 d exposu...

  7. Combined down-regulation by aromatase inhibitor and GnRH-agonist in IVF patients with endometriomas-A pilot study

    DEFF Research Database (Denmark)

    Lossl, Kristine; Løssl, Kristine; Loft, Anne;

    2009-01-01

    OBJECTIVE: The key enzyme in the biosynthesis of estradiol, aromatase, has been demonstrated within endometriosis. Combined administration of aromatase inhibitor and GnRH-agonist may efficiently suppress estrogen biosynthesis through a combined pituitary, ovarian, peripheral and "in situ" action...

  8. Aromatase expression is linked to estrogenic sensitivity of periurethral muscles in female rabbits.

    Science.gov (United States)

    de los Ángeles Carrasco-Ruiz, María; García-Villamar, Verónica; López-García, Kenia; Sánchez-García, Octavio; Pacheco, Pablo; Cuevas, Estela; Martínez-Gómez, Margarita; Castelán, Francisco

    2015-06-01

    Beyond its role in the conversion of androgens to estrogens, the expression of aromatase could influence on the estrogenic signalling in targeted tissues. Considering the well-defined biochemical and physiological differences between the pubococcygeus (Pcm) and bulbospongiosus (Bsm) muscles in female rabbits, it is presently hypothesized that the aromatase expression is differentially linked to the estrogen sensitivity of each muscle. To this end, serum estradiol levels and the aromatase expression, presence of ERα and ERβ and morphometry were evaluated in the Pcm and Bsm of female rabbits allocated in control, ovariectomized (OVX) and OVX treated with estradiol benzoate (OVX + EB) groups. Aromatase expression was high in the Pcm. Independently to serum estradiol, ovariectomy increased aromatase expression in the Pcm while decreased it in the Bsm. The EB treatment avoided the effect of ovariectomy only in the Pcm. The number of immunoreactive nuclei anti-ERα and anti-ERβ was high in the Pcm of OVX and OVX + EB rabbits, while those in the Bsm remained unchanged. The number of peripheral nuclei per fibre and the cross-sectional area-to-myonucleus ratio were modified only in the Pcm. Our findings support aromatase expression in the Pcm, and Bsm of rabbits is differentially linked to estrogenic sensitivity of each muscle.

  9. Postmenopausal Breast Cancer, Aromatase Inhibitors, and Bone Health: What the Surgeon Should Know.

    Science.gov (United States)

    Baatjes, K J; Apffelstaedt, J P; Kotze, M J; Conradie, M

    2016-09-01

    Breast cancer, as the most common malignancy in women, remains a major public health issue despite countless advances across decades. Endocrine therapy is the cornerstone of treatment of the hormone-sensitive subtype of breast cancer. The use of aromatase inhibitors (AIs) in the postmenopausal women has extended the survival beyond that of Tamoxifen, but harbors a subset of side effects, most notably accelerated bone loss. This, however, does not occur in all women undergoing treatment. It is vital to identify susceptible patients early, to limit such events, employ early treatment thereof, or alter drug therapy. International trials on AIs, predominantly performed in North American and European females, provide little information on what to expect in women in developing countries. Here, surgeons often prescribe and manage endocrine therapy. The prescribing surgeon should be aware of the adverse effect of the endocrine therapy and be able to attend to side effects. This review highlights clinical and biochemical factors associated with decrease in bone mineral density in an, as yet, unidentified subgroup of postmenopausal women. In the era of personalized medical care, appropriate management of bone health by surgeons based on these factors becomes increasingly important. PMID:27189076

  10. Design, synthesis, and biological evaluation of resveratrol analogues as aromatase and quinone reductase 2 inhibitors for chemoprevention of cancer

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Bin; Hoshino, Juma; Jermihov, Katie; Marler, Laura; Pezzuto, John M.; Mesecar, Andrew D.; Cushman, Mark (Hawaii); (Purdue); (UIC)

    2012-07-11

    A series of new resveratrol analogues were designed and synthesized and their inhibitory activities against aromatase were evaluated. The crystal structure of human aromatase (PDB 3eqm) was used to rationalize the mechanism of action of the aromatase inhibitor 32 (IC{sub 50} 0.59 {mu}M) through docking, molecular mechanics energy minimization, and computer graphics molecular modeling, and the information was utilized to design several very potent inhibitors, including compounds 82 (IC{sub 50} 70 nM) and 84 (IC{sub 50} 36 nM). The aromatase inhibitory activities of these compounds are much more potent than that for the lead compound resveratrol, which has an IC{sub 50} of 80 {mu}M. In addition to aromatase inhibitory activity, compounds 32 and 44 also displayed potent QR2 inhibitory activity (IC{sub 50} 1.7 {mu}M and 0.27 {mu}M, respectively) and the high-resolution X-ray structures of QR2 in complex with these two compounds provide insight into their mechanism of QR2 inhibition. The aromatase and quinone reductase inhibitors resulting from these studies have potential value in the treatment and prevention of cancer.

  11. Design, synthesis, and biological evaluation of resveratrol analogues as aromatase and quinone reductase 2 inhibitors for chemoprevention of cancer

    International Nuclear Information System (INIS)

    A series of new resveratrol analogues were designed and synthesized and their inhibitory activities against aromatase were evaluated. The crystal structure of human aromatase (PDB 3eqm) was used to rationalize the mechanism of action of the aromatase inhibitor 32 (IC50 0.59 μM) through docking, molecular mechanics energy minimization, and computer graphics molecular modeling, and the information was utilized to design several very potent inhibitors, including compounds 82 (IC50 70 nM) and 84 (IC50 36 nM). The aromatase inhibitory activities of these compounds are much more potent than that for the lead compound resveratrol, which has an IC50 of 80 μM. In addition to aromatase inhibitory activity, compounds 32 and 44 also displayed potent QR2 inhibitory activity (IC50 1.7 μM and 0.27 μM, respectively) and the high-resolution X-ray structures of QR2 in complex with these two compounds provide insight into their mechanism of QR2 inhibition. The aromatase and quinone reductase inhibitors resulting from these studies have potential value in the treatment and prevention of cancer.

  12. Managing arthralgia in a postmenopausal woman taking an aromatase inhibitor for hormonesensitive early breast cancer: a case study

    International Nuclear Information System (INIS)

    In order to reduce the risk of recurrence, adjuvant treatment with an aromatase inhibitor (AI) is recommended for postmenopausal women following surgery for hormone receptor-positive breast cancer. AIs are associated with improved disease-free survival compared with tamoxifen. The adverse events associated with AIs resemble those of menopause, such as bone density loss and musculoskeletal symptoms. We examine the case of a postmenopausal woman who was prescribed anastrozole, a nonsteroidal AI, as adjuvant therapy following surgery for estrogen and progesterone receptor-positive (ER and PgR+) breast cancer. A 58-year-old postmenopausal woman diagnosed with ER and PgR+ breast cancer was prescribed anastrozole as adjuvant therapy following a right-inferior quadrantectomy. After experiencing joint pain and stiffness, she was prescribed paracetamol and a topical nonsteroidal anti-inflammatory drug. She was also counseled on nonpharmacological interventions. However, she continued to experience symptoms, and reported that she was not taking anastrozole regularly. The case study patient ultimately found relief by switching to letrozole, another aromatase inhibitor. This approach is supported by recent studies examining the benefits of switching strategies between aromatase inhibitors in order to relieve symptoms of arthralgia/myalgia. Both adherence and strategies for managing aromatase inhibitor-associated arthralgia are key to deriving maximal clinical benefit from AI therapy. Switching from one aromatase inhibitor to another may provide a viable option in managing adverse events and enhancing adherence to medication

  13. Synthesis of Triphenylethylene Bisphenols as Aromatase Inhibitors That Also Modulate Estrogen Receptors.

    Science.gov (United States)

    Lv, Wei; Liu, Jinzhong; Skaar, Todd C; O'Neill, Elizaveta; Yu, Ge; Flockhart, David A; Cushman, Mark

    2016-01-14

    A series of triphenylethylene bisphenol analogues of the selective estrogen receptor modulator (SERM) tamoxifen were synthesized and evaluated for their abilities to inhibit aromatase, bind to estrogen receptor α (ER-α) and estrogen receptor β (ER-β), and antagonize the activity of β-estradiol in MCF-7 human breast cancer cells. The long-range goal has been to create dual aromatase inhibitor (AI)/selective estrogen receptor modulators (SERMs). The hypothesis is that in normal tissue the estrogenic SERM activity of a dual AI/SERM could attenuate the undesired effects stemming from global estrogen depletion caused by the AI activity of a dual AI/SERM, while in breast cancer tissue the antiestrogenic SERM activity of a dual AI/SERM could act synergistically with AI activity to enhance the antiproliferative effect. The potent aromatase inhibitory activities and high ER-α and ER-β binding affinities of several of the resulting analogues, together with the facts that they antagonize β-estradiol in a functional assay in MCF-7 human breast cancer cells and they have no E/Z isomers, support their further development in order to obtain dual AI/SERM agents for breast cancer treatment. PMID:26704594

  14. Aromatase Inhibitors for Endometriosis-Associated Infertility; Do We Have Sufficient Evidence?

    Science.gov (United States)

    Abu Hashim, Hatem

    2016-01-01

    Orally active aromatase inhibitors (AIs) have gained attention for treatment of infertile women with endometriosis in whom aromatase p450 is aberrantly expressed. This review aimed to critically appraise and summarize the available evidence concerning the use of AIs for management of endometriosis-associated infertility. PubMed was searched to May 2015 with the following key words: endometriosis, infertility and aromatase. Priority was given for randomized controlled trials (RCTs) followed by other study designs. Main outcome measures were as follows: rates of clinical pregnancy, miscarriage and live birth as well as endocrine outcomes. Eighty-two abstracts were screened and six original articles were included. A RCT demonstrated that post-operative letrozole treatment did not improve spontaneous pregnancy rate. Another RCT reported no superiority of letrozole superovulation over clomiphene citrate (each combined with intrauterine insemination) in minimalmild endometriosis and previous laparoscopic treatment. Anastrozole significantly inhibited the growth of endometriotic cells and their estrogen production in culture. In assisted reproductive technology (ART) cycles, dual suppression (Agonist/anastrozole) was tested in a pilot study with a pregnancy rate of 45% however, high pregnancy loss (30%) occurred. A retrospective study showed that letrozole may improve endometrial receptivity in endometriotic patients undergoing in vitro fertilization (IVF). An opposite view from an in vitro study showed lower estradiol production and aromatase expression in cultured granulosa cells from endometriotic women undergoing IVF and marked reduction under letrozole. In conclusion, current evidence is limited. More trials are warranted to enhance our knowledge and provide a clear and unequivocal evidence to guide our clinical management of infertile women with endometriosis using AIs. PMID:27695608

  15. Everolimus downregulates estrogen receptor and induces autophagy in aromatase inhibitor-resistant breast cancer cells

    OpenAIRE

    Lui, Asona; New, Jacob; Ogony, Joshua; Thomas, Sufi; Lewis-Wambi, Joan

    2016-01-01

    Background mTOR inhibition of aromatase inhibitor (AI)-resistant breast cancer is currently under evaluation in the clinic. Everolimus/RAD001 (Afinitor®) has had limited efficacy as a solo agent but is projected to become part of combination therapy for AI-resistant breast cancer. This study was conducted to investigate the anti-proliferative and resistance mechanisms of everolimus in AI-resistant breast cancer cells. Methods In this study we utilized two AI-resistant breast cancer cell lines...

  16. Synthesis and PET studies of [11C-cyano]letrozole (Femara), an aromatase inhibitor drug

    International Nuclear Information System (INIS)

    Introduction: Aromatase, a member of the cytochrome P450 family, converts androgens such as androstenedione and testosterone into estrone and estradiol, respectively. Letrozole (1-[bis-(4-cyanophenyl)methyl]-1H-1,2,4-triazole; Femara) is a high-affinity aromatase inhibitor (Ki=11.5 nM) that has Food and Drug Administration approval for breast cancer treatment. Here we report the synthesis of carbon-11-labeled letrozole and its assessment as a radiotracer for brain aromatase in the baboon. Methods: Letrozole and its precursor (4-[(4-bromophenyl)-1H-1,2,4-triazol-1-ylmethyl]benzonitrile) were prepared in a two-step synthesis from 4-cyanobenzyl bromide and 4-bromobenzyl bromide, respectively. The [11C]cyano group was introduced via tetrakis(triphenylphosphine)palladium(0)-catalyzed coupling of [11C]cyanide with the bromo precursor. Positron emission tomography (PET) studies in the baboon brain were carried out to assess regional distribution and kinetics, reproducibility of repeated measures and saturability. Log D, the free fraction of letrozole in plasma and the [11C-cyano]letrozole fraction in arterial plasma were also measured. Results: [11C-cyano]Letrozole was synthesized in 60 min with a radiochemical yield of 79-80%, with a radiochemical purity greater than 98% and a specific activity of 4.16±2.21 Ci/μmol at the end of bombardment (n=4). PET studies in the baboon revealed initial rapid and high uptake and initial rapid clearance, followed by slow clearance of carbon-11 from the brain, with no difference between brain regions. Brain kinetics was not affected by coinjection of unlabeled letrozole (0.1 mg/kg). The free fraction of letrozole in plasma was 48.9%, and log D was 1.84. Conclusion: [11C-cyano]Letrozole is readily synthesized via a palladium-catalyzed coupling reaction with [11C]cyanide. Although it is unsuitable as a PET radiotracer for brain aromatase, as revealed by the absence of regional specificity and saturability in brain regions such as

  17. Long-term safety of aromatase inhibitors in the treatment of breast cancer

    Directory of Open Access Journals (Sweden)

    Jean-Marc A Nabholtz

    2008-03-01

    Full Text Available Jean-Marc A NabholtzBreast Cancer Research Institute La Prandie, Valojoulx, FranceAbstract: Following promising data for metastatic breast cancer in terms of efficacy and safety profile, third-generation aromatase inhibitors (AI, anastrozole, letrozole, and exemestane, underwent a full development in early setting. If recent results consistently show the superiority of these agents over tamoxifen, the therapeutic strategies of AIs in adjuvant setting are still debated. Beyond the choice of clinical strategy, the long duration of exposure to AI in adjuvant setting required a full determination of the long-term toxicity profile of these agents. While all three AIs have either favorable (decreased incidence of hot flashes, gynecologic and thromboembolic side-effects or unfavorable (skeletal complications, arthralgia, musculoskeletal pain, sexual dysfunction class adverse events, some variability between AIs has been reported in side-effects as well as gastrointestinal, urogenital, neurologic, and visual disturbances, confirming the lack of interchangeability between the three AIs. The overall therapeutic index of AIs appears today superior to that of tamoxifen with proven improved efficacy and better toxicity profile. This review will explore the results from the available adjuvant AIs trials with a particular emphasis on safety profiles, quality of life, and therapeutic index, helping to define the present role of AIs in the adjuvant management of postmenopausal patients with breast cancer.Keywords: breast cancer, aromatase inhibitors, adjuvant, safety profile

  18. Aromatase inhibitor-associated bone loss and its management with bisphosphonates in patients with breast cancer

    Directory of Open Access Journals (Sweden)

    Bauer M

    2012-06-01

    Full Text Available M Bauer,1 J Bryce,2 P Hadji11University of Marburg, Marburg, Germany; 2National Cancer Institute, Naples, ItalyAbstract: Postmenopausal women have an increased risk of osteopenia and osteoporosis due to loss of the bone-protective effects of estrogen. Disease-related processes may also contribute to the risk of bone loss in postmenopausal women with breast cancer. One of the most common and severe safety issues associated with cancer therapy for patients with breast cancer is bone loss and the associated increase in risk of fractures. This paper reviews the recent literature pertaining to aromatase inhibitor (AI-associated bone loss, and discusses suggested management and preventative approaches that may help patients remain on therapy to derive maximum clinical benefit. A case study is presented to illustrate the discussion. We observed that AIs are in widespread use for women with hormone receptor-positive breast cancer and are now recommended as adjuvant therapy, either as primary therapy or sequential to tamoxifen, for postmenopausal women. AIs target the estrogen biosynthetic pathway and deprive tumor cells of the growth-promoting effects of estrogen, and AI therapies provide benefits to patients in terms of improved disease-free survival. However, there is a concern regarding the increased risk of bone loss with prolonged AI therapy, which can be managed in many cases with the use of bisphosphonates and other interventions (eg, calcium, vitamin D supplementation, exercise.Keywords: aromatase inhibitors, bisphosphonates, bone loss, breast cancer, estrogen

  19. Arthralgia during aromatase inhibitor treatment in early breast cancer patients: prevalence, impact, and recognition by healthcare providers

    NARCIS (Netherlands)

    Boonstra, A.; Zadelhoff, J. van; Timmer-Bonte, J.N.H.; Ottevanger, P.B.; Beurskens, C.H.G.; Laarhoven, H.W.M. van

    2013-01-01

    BACKGROUND: : Many breast cancer patients experience arthralgia symptoms during aromatase inhibitor (AI) treatment, which leads to poor compliance and a lower quality of life. OBJECTIVE: : The research questions of this study were as follows: (1) What is the incidence of arthralgia during AI treatme

  20. Induction of Female-to-Male Sex Change in Adult Zebrafish by Aromatase Inhibitor Treatment

    Science.gov (United States)

    Takatsu, Kanae; Miyaoku, Kaori; Roy, Shimi Rani; Murono, Yuki; Sago, Tomohiro; Itagaki, Hideyuki; Nakamura, Masaru; Tokumoto, Toshinobu

    2013-12-01

    This study investigated whether undifferentiated germ and/or somatic stem cells remain in the differentiated ovary of a species that does not undergo sex changes under natural conditions and retain their sexual plasticity. The effect of aromatase inhibitor (AI)-treatment on sexually mature female zebrafish was examined. A 5-month AI treatment caused retraction of the ovaries after which testes-like organs appeared, and cyst structures filled with spermatozoa-like cells were observed in sections of these tissues. Electron microscopic observations revealed that these cells appeared as large sperm heads without tails. Sperm formation was re-examined after changing the diet to an AI-free food. A large number of normal sperm were obtained after eight weeks, and no formation of ovarian tissue was observed. Artificial fertilization using sperm from the sex-changed females was successful. These results demonstrated that sex plasticity remains in the mature ovaries of this species.

  1. Aromatase inhibitors, efficacy and metabolic risk in the treatment of postmenopausal women with early breast cancer

    Directory of Open Access Journals (Sweden)

    Stefano Gonnelli

    2008-11-01

    Full Text Available Stefano Gonnelli1, Roberto Petrioli21Department of Internal Medicine, Endocrine-Metabolic Science and Biochemistry, University of Siena, Italy (Dir. R. Nuti.; 2Department of Human Pathology and Oncology, Medical Oncology Section, University of Siena, Italy (Dir. G. FranciniAbstract: The third-generation aromatase inhibitors (AIs, letrozole, anastrozole and exemestane, are becoming the first choice endocrine drugs for post-menopausal women with breast cancer, since they present greater efficacy when compared with tamoxifen in both adjuvant and metastatic setting. In particular, several large and well designed trials have suggested an important role for AIs in the adjuvant treatment of postmenopausal women with estrogen-receptor positive breast cancer either in the upfront, sequential or extended adjuvant mode. Overall, AIs are associated with a small but significant improvement in disease free survival. The expanding use of AIs in the treatment of early breast cancer means that individual patients will be exposed to the agents for longer durations, making it increasingly important to establish their long-term safety. This review focused on the effects of AIs on bone metabolism, serum lipids and cardiovascular risk. AIs have adverse effects on bone turnover with a reduction of bone mineral density and an increase in the rate of fragility fractures. With respect to tamoxifen AIs present lower thrombotic risk and a less favorable impact on lipid profile, whereas the true effects on cardiovascular risk still remain to be clarified. An adequate monitoring of bone mineral density (BMD and lipid profile could be recommended for post-menopausal women candidate to AIs.Keywords: breast cancer, aromatase inhibitors, bone loss, lipids, cardiovascular risk

  2. Aromatase inhibitors, efficacy and metabolic risk in the treatment of postmenopausal women with early breast cancer

    Directory of Open Access Journals (Sweden)

    Stefano Gonnelli

    2008-12-01

    Full Text Available Stefano Gonnelli1, Roberto Petrioli21Department of Internal Medicine, Endocrine-Metabolic Science and Biochemistry, University of Siena, Italy (Dir. R. Nuti.; 2Department of Human Pathology and Oncology, Medical Oncology Section, University of Siena, Italy (Dir. G. FranciniAbstract: The third-generation aromatase inhibitors (AIs, letrozole, anastrozole and exemestane, are becoming the first choice endocrine drugs for post-menopausal women with breast cancer, since they present greater efficacy when compared with tamoxifen in both adjuvant and metastatic setting. In particular, several large and well designed trials have suggested an important role for AIs in the adjuvant treatment of postmenopausal women with estrogen-receptor positive breast cancer either in the upfront, sequential or extended adjuvant mode. Overall, AIs are associated with a small but significant improvement in disease free survival. The expanding use of AIs in the treatment of early breast cancer means that individual patients will be exposed to the agents for longer durations, making it increasingly important to establish their long-term safety. This review focused on the effects of AIs on bone metabolism, serum lipids and cardiovascular risk. AIs have adverse effects on bone turnover with a reduction of bone mineral density and an increase in the rate of fragility fractures. With respect to tamoxifen AIs present lower thrombotic risk and a less favorable impact on lipid profile, whereas the true effects on cardiovascular risk still remain to be clarified. An adequate monitoring of bone mineral density (BMD and lipid profile could be recommended for post-menopausal women candidate to AIs.Keywords: breast cancer, aromatase inhibitors, bone loss, lipids, cardiovascular risk

  3. Molecular characterization of aromatase

    OpenAIRE

    Hong, Yanyan; Li, Hongzhi; Yuan, Yate-Ching; Chen, Shiuan

    2009-01-01

    Aromatase is an estrogen synthetase. Estrogens are female sex hormones involved in the development and growth of breast tumors. It has been of significant interest to elucidate the structure-function relationship of aromatase since its inhibitors have shown great promise in fighting breast cancer. Aromatase belongs to the cytochrome P450 family, and forms an electron-transfer complex with its partner, NADPH-cytochrome P450 reductase. Because of the membrane-bound character and heme-binding in...

  4. Advances in breast cancer treatment and prevention: preclinical studies on aromatase inhibitors and new selective estrogen receptor modulators (SERMs)

    OpenAIRE

    Schiff, Rachel; Chamness, Gary C.; Brown, Powel H.

    2003-01-01

    Intensive basic and clinical research over the past 20 years has yielded crucial molecular understanding into how estrogen and the estrogen receptor act to regulate breast cancer and has led to the development of more effective, less toxic, and safer hormonal therapy agents for breast cancer management and prevention. Selective potent aromatase inhibitors are now challenging the hitherto gold standard of hormonal therapy, the selective estrogen-receptor modulator tamoxifen. Furthermore, new s...

  5. Use of aromatase inhibitors to treat endometriosis-related pain symptoms: a systematic review

    Directory of Open Access Journals (Sweden)

    Venturini Pier L

    2011-06-01

    Full Text Available Abstract This systematic review aims to assess the efficacy of aromatase inhibitors (AIs in treating pain symptoms caused by endometriosis. A comprehensive literature search was conducted to identify all the published studies evaluating the efficacy of type II nonsteroidal aromatase inhibitors (anastrozole and letrozole in treating endometriosis-related pain symptoms. The MEDLINE, EMBASE, PubMed, and SCOPUS databases and the Cochrane System Reviews were searched up to October 2010. This review comprises of the results of 10 publications fitting the inclusion criteria; these studies included a total of 251 women. Five studies were prospective non-comparative, four were randomized controlled trials (RCTs and one was a prospective patient preference trial. Seven studies examined the efficacy of AIs in improving endometriosis-related pain symptoms, whilst three RCTs investigated the use of AIs as post-operative therapy in preventing the recurrence of pain symptoms after surgery for endometriosis. All the observational studies demonstrated that AIs combined with either progestogens or oral contraceptive pill reduce the severity of pain symptoms and improve quality of life. One patient preference study demonstrated that letrozole combined with norethisterone acetate is more effective in reducing pain and deep dyspareunia than norethisterone acetate alone. However, letrozole causes a higher incidence of adverse effects and does not improve patients' satisfaction or influence recurrence of symptoms after discontinuation of treatment. A RCT showed that combining letrozole with norethisterone acetate causes a lower incidence of adverse effects and lower discontinuation rate than combining letrozole with triptorelin. Two RCTs demonstrated that, after surgical treatment of endometriosis, the administration of AIs combined with gonadotropin releasing hormone analogue for 6 months reduces the risk of endometriosis recurrence when compared with gonadotropin

  6. Vaginal estrogen products in hormone receptor-positive breast cancer patients on aromatase inhibitor therapy.

    Science.gov (United States)

    Sulaica, Elisabeth; Han, Tiffany; Wang, Weiqun; Bhat, Raksha; Trivedi, Meghana V; Niravath, Polly

    2016-06-01

    Atrophic vaginitis represents a major barrier to compliance with aromatase inhibitor (AI) therapy in breast cancer (BC) survivors. While local estrogen therapy is effective for postmenopausal vaginal dryness, the efficacy of such therapies has not been evaluated systematically in hormone receptor-positive (HR+) BC patients on AI therapy. Furthermore, the potential risk of breast cancer recurrence with vaginal estrogen therapy represents a long-term safety concern for the patients with HR + BC. Unfortunately, there is no standardized assay to measure very low concentrations of estradiol (E2) in these women being treated with AI therapy. This makes it difficult to evaluate even indirectly the potential risk of BC recurrence with vaginal estrogen therapy in HR + BC patients on AI therapy. In this review, we describe available assays to measure very low concentrations of E2, discuss the Food and Drug Administration-approved vaginal estrogen products on the market, and summarize published and ongoing clinical trials evaluating the safety and efficacy of vaginal estrogen in HR + BC patients on AI therapy. In the absence of any randomized controlled clinical trials, this review serves as a summary of available clinical data and ongoing studies to aid clinicians in selecting the best available option for their patients. PMID:27178335

  7. Masculinization of female golden rabbitfish Siganus guttatus using an aromatase inhibitor treatment during sex differentiation.

    Science.gov (United States)

    Komatsu, Toru; Nakamura, Shigeo; Nakamura, Masaru

    2006-08-01

    To elucidate the involvement of endogenous estrogen (estradiol-17beta; E2) and the decisive factor (somatic or germinal element) in the ovarian differentiation of tropical marine teleosts, the effect of the aromatase inhibitor (AI) fadrozole on gonadal sex differentiation in the golden rabbitfish Siganus guttatus (Bloch) was examined for different dosages and periods of treatment. Fadrozole interrupted ovarian cavity formation at a dose of 500 microg g(-1) diet, while there was little effect at 10 or 100 microg g(-1). The gonads from both the 30-day and 90-day administration (500 microg g(-1) diet) groups were significantly biased toward testes (P=0.002 and <0.0001, respectively), which suggests strongly that E2 is involved in early ovarian differentiation and that its suppression is an indispensable condition for testicular differentiation in S. guttatus. The results from the two different AI treatment periods imply that the initial feminization of somatic gonadal elements determines subsequent ovarian differentiation, including oogenesis: a conclusion supported by the considerable time lag between ovarian cavity formation and subsequent oogenesis during normal ovarian differentiation in S. guttatus.

  8. Aromatase inhibitors induced autoimmune disorders in patients with breast cancer: A review

    Directory of Open Access Journals (Sweden)

    George Zarkavelis

    2016-09-01

    Full Text Available Subacute cutaneous lupus erythematosus (SCLE is characterized by particular cutaneous manifestations such as non-scaring plaques mainly in sunlight exposed parts of the body along with specific serum autoantibodies (i.e. antinuclear antibodies (ANA, Ro/SSa, La/SSb. It is considered either idiopathic or drug induced. The role of chemotherapeutic agents in causing SCLE has been investigated with the taxanes being the most common anticancer agents. However, recent data emerging point toward antiestrogen therapies as a causative factor not only for SCLE but also for a variety of autoimmune disorders. This is a report of a case of a 42 year old woman who developed clinical manifestations of SCLE after letrozole treatment in whom remission of the cutaneous manifestations was noticed upon discontinuation of the drug. In addition, an extensive review of the English literature has been performed regarding the association of antiestrogen therapy with autoimmune disorders. In conclusion, Oncologists should be aware of the potential development of autoimmune reactions in breast cancer patients treated with aromatase inhibitors.

  9. A Case of Erythrocytosis in a Patient Treated with an Aromatase Inhibitor for Breast Cancer

    Directory of Open Access Journals (Sweden)

    Abhinav Iyengar

    2013-01-01

    Full Text Available A previously healthy 79-year-old female was referred to hematology for further evaluation of erythrocytosis. Two years earlier she had been diagnosed with ER/PR-positive ductal carcinoma of the breast and was receiving hormonal therapy with exemestane. No secondary cause of erythrocytosis was identified. Serum erythropoietin (EPO level was normal, and molecular testing for the JAK2 V617F and exon 12 mutations was negative. A bone marrow biopsy showed a mild increase in erythropoiesis, and no spontaneous erythroid colonies were demonstrated. Erythrocytosis is common reason for referral to a hematologist. The myeloproliferative disorder, polycythemia vera, and the rare congenital polycythemias represent primary erythrocytosis. Common secondary causes include smoking, obstructive sleep apnea, and other pulmonary diseases. Erythrocytosis is well described with certain classes of drugs, including androgens. We hypothesize that exemestane contributed to the development of erythrocytosis in our patient. To our knowledge, erythrocytosis has not been previously described in association with aromatase inhibitors. These drugs prevent the conversion of androstenedione and testosterone to estrogen; thus the physiologic mechanisms may be similar to those responsible for erythrocytosis seen with exogenous androgens. These mechanisms are not well understood, but may include altered iron metabolism by a reduction in hepcidin levels.

  10. Comparative study on individual aromatase inhibitors on cardiovascular safety profile: a network meta-analysis

    Science.gov (United States)

    Zhao, Xihe; Liu, Lei; Li, Kai; Li, Wusheng; Zhao, Li; Zou, Huawei

    2015-01-01

    The third-generation aromatase inhibitors (AIs: anastrozole, letrozole, and exemestane) have now become standard adjuvant endocrine treatment for postmenopausal estrogen receptor-positive breast cancer complementing chemotherapy and surgery. Because of the absence of direct head-to-head comparisons of these AIs, an indirect comparison is needed for individual treatment choice. In this network systemic assessment, the cardiovascular (CV) side effects in using anastrozole, letrozole, and exemestane based on original studies on AIs vs placebo or tamoxifen were compared. We integrated all available direct and indirect evidences. The odds ratio (OR) of severe CV events for indirect comparisons between exemestane and anastrozole was 1.41 (95% confidence interval [CI] =0.49–2.78), letrozole and anastrozole was 1.80 (95% CI =0.40–3.92), and letrozole and exemestane was 1.46 (95% CI =0.34–3.4). OR of subgroup risk for AIs and tamoxifen were all >1 except for thrombolism risk subgroup. The results showed that the total and severe CV risk ranking is letrozole, exemestane, and anastrozole in descending order. None of the AIs showed advantages in CV events than tamoxifen except for thromboembolism event incidence. PMID:26491345

  11. Vaginal estrogen products in hormone receptor-positive breast cancer patients on aromatase inhibitor therapy.

    Science.gov (United States)

    Sulaica, Elisabeth; Han, Tiffany; Wang, Weiqun; Bhat, Raksha; Trivedi, Meghana V; Niravath, Polly

    2016-06-01

    Atrophic vaginitis represents a major barrier to compliance with aromatase inhibitor (AI) therapy in breast cancer (BC) survivors. While local estrogen therapy is effective for postmenopausal vaginal dryness, the efficacy of such therapies has not been evaluated systematically in hormone receptor-positive (HR+) BC patients on AI therapy. Furthermore, the potential risk of breast cancer recurrence with vaginal estrogen therapy represents a long-term safety concern for the patients with HR + BC. Unfortunately, there is no standardized assay to measure very low concentrations of estradiol (E2) in these women being treated with AI therapy. This makes it difficult to evaluate even indirectly the potential risk of BC recurrence with vaginal estrogen therapy in HR + BC patients on AI therapy. In this review, we describe available assays to measure very low concentrations of E2, discuss the Food and Drug Administration-approved vaginal estrogen products on the market, and summarize published and ongoing clinical trials evaluating the safety and efficacy of vaginal estrogen in HR + BC patients on AI therapy. In the absence of any randomized controlled clinical trials, this review serves as a summary of available clinical data and ongoing studies to aid clinicians in selecting the best available option for their patients.

  12. Gene expression alterations associated with outcome in aromatase inhibitor-treated ER+ early-stage breast cancer patients.

    Science.gov (United States)

    Thomsen, Karina G; Lyng, Maria B; Elias, Daniel; Vever, Henriette; Knoop, Ann S; Lykkesfeldt, Anne E; Lænkholm, Anne-Vibeke; Ditzel, Henrik J

    2015-12-01

    Aromatase inhibitors (AI), either alone or together with chemotherapy, have become the standard adjuvant treatment for postmenopausal, estrogen receptor-positive (ER+) breast cancer. Although AIs improve overall survival, resistance is still a major clinical problem, thus additional biomarkers predictive of outcome of ER+ breast cancer patients treated with AIs are needed. Global gene expression analysis was performed on ER+ primary breast cancers from patients treated with adjuvant AI monotherapy; half experienced recurrence (median follow-up 6.7 years). Gene expression alterations were validated by qRT-PCR, and functional studies evaluating the effect of siRNA-mediated gene knockdown on cell growth were performed. Twenty-six genes, including TFF3, DACH1, RGS5, and GHR, were shown to exhibit altered expression in tumors from patients with recurrence versus non-recurrent (fold change ≥1.5, p proliferation, growth, and development. TFF3, which encodes for trefoil factor 3 and is an estrogen-responsive oncogene shown to play a functional role in tamoxifen resistance and metastasis of ER+ breast cancer, was also shown to be upregulated in an AI-resistant cell line model, and reduction of TFF3 levels using TFF3-specific siRNAs decreased the growth of both the AI-resistant and -sensitive parental cell lines. Moreover, overexpression of TFF3 in parental AI-sensitive MCF-7/S0.5 cells resulted in reduced sensitivity to the AI exemestane, whereas TFF3 overexpression had no effect on growth in the absence of exemestane, indicating that TFF3 mediates growth and survival signals that abrogate the growth inhibitory effect of exemestane. We identified a panel of 26 genes exhibiting altered expression associated with disease recurrence in patients treated with adjuvant AI monotherapy, including TFF3, which was shown to exhibit a growth- and survival-promoting effect in the context of AI treatment.

  13. Evaluation of the quality and accuracy of information regarding aromatase inhibitors available on the internet.

    Science.gov (United States)

    Beaton, Ceri; Codd, Rhodri J; Holland, Phillip A; Gateley, Christopher A

    2008-01-01

    The internet is commonly used by patients to access medical information, particularly where new treatments become available and are highlighted in the press. There is however, no regulation of the quality or accuracy of the information presented on web sites. The aim of this study was to evaluate the quality and accuracy of the information concerning the aromatase inhibitors (AIs). The three most popular search engines: Google, Yahoo, and MSN were utilized. The top ten "hits" for the generic and proprietary names of each AIs: anastrozole (Arimidex), exemestane (Aromasin), and letrozole (Femara) were evaluated using a 12-point score by a single assessor. The accuracy of the information provided was compared with the National Institute for Health and Clinical Excellence guidelines. The mean score for the 180 web sites was only 6.13 out of 12 (0-11). If we consider a score of 9 or more out of 12 (> or =75%) for a web site to represent good quality information, then 51 (28%) of pages scored well. Google was slightly better than Yahoo and MSN; with the highest percentage of web sites scoring well. In evaluating hits according to type of web sites, 50 (28%) were charity web sites and 30 (17%) were drug company web sites and both groups scored significantly higher than the overall mean (charity p = 0.014, drug company p = 0.001). Only 2 of 180 hits gave accurate statistical evidence regarding the benefits of AIs over tamoxifen. We have found that the quality and accuracy of information concerning AIs provided on the Internet is poor and patients using it are unlikely to find accurate information. It is therefore our duty as healthcare providers to guide patients, so as to avoid them from being overwhelmed by irrelevant and conflicting information. PMID:18537915

  14. Reduced estradiol synthesis by letrozole, an aromatase inhibitor, is protective against development of pentylenetetrazole-induced kindling in mice.

    Science.gov (United States)

    Rashid, Davood; Panda, B P; Vohora, Divya

    2015-11-01

    Neurosteroids, such as testosterone and their metabolites, are known to modulate neuronal excitability. The enzymes regulating the metabolism of these neurosteroids, thus, may be targeted as a noval strategy for the development of new antiepileptic drugs. The present work targeted two such enzymes i,e aromatase and 5α-reductase in order to explore the potential of letrozole (an aromatase inhibitor) on pentylenetetrazole (PTZ)-induced kindling in mice and the ability of finasteride (a 5α-reductase inhibitor) to modulate any such effects. PTZ (30 mg/kg, i.p.), when administered once every two days (for a total of 24 doses) induced kindling in Swiss albino mice. Letrozole (1 mg/kg, p.o.), administered prior to PTZ, significantly reduced the % incidence of kindling, delayed mean onset time of seizures and reduced seizure severity score. Letrozole reduced the levels of plasma 17β-estradiol after induction of kindling. The concurrent administration of finasteride and letrozole produced effects similar to letrozole on PTZ-kindling and on estradiol levels. This implies that the ability of letrozole to redirect the synthesis of dihydrotestosterone (DHT) and 5α-androstanediol from testosterone doesn't appear to play a significant role in the protective effects of letrozole against PTZ kindling. Letrozole, however, increased the levels of 5α-DHT in mice plasma. The aromatase inhibitors, thus, may be exploited for inhibiting the synthesis of proconvulsant (17β-estradiol) and/or redirecting the synthesis of anticonvulsant (DHT and 5α-androstanediol) neurosteroids.

  15. Synthesis and PET studies of [11C-cyano]letrozole (Femara®), an aromatase inhibitor drug

    Science.gov (United States)

    Kil, Kun-Eek; Biegon, Anat; Ding, Yu-Shin; Fischer, Andre; Ferrieri, Richard A.; Kim, Sung Won; Pareto, Deborah; Schueller, Michael J.; Fowler, Joanna S.

    2011-01-01

    Introduction Aromatase, a member of the cytochrome P450 family, converts androgens such as androstenedione and testosterone to estrone and estradiol respectively. Letrozole (1-[bis-(4-cyanophenyl)methyl]-1H-1,2,4-triazole, Femara®) is a high affinity aromatase inhibitor (Ki=11.5 nM) which has FDA approval for breast cancer treatment. Here we report the synthesis of carbon-11 labeled letrozole and its assessment as a radiotracer for brain aromatase in the baboon. Methods Letrozole and its precursor (4-[(4-bromophenyl)-1H-1,2,4-triazol-1-ylmethyl]benzonitrile, 3) were prepared in two-step syntheses from 4-cyanobenzyl bromide and 4-bromobenzyl bromide, respectively. The [11C]cyano group was introduced via the tetrakis(triphenylphosphine)palladium(0) catalyzed coupling of [11C]cyanide with the bromo-precursor (3). PET studies in the baboon brain were carried out to assess regional distribution and kinetics, reproducibility of repeated measures and saturability. The free fraction of letrozole in the plasma, log D, and the [11C-cyano]letrozole fraction in the arterial plasma were also measured. Results [11C-cyano]Letrozole was synthesized in 60 min with a radiochemical yield of 79–80%, with a radiochemical purity greater than 98% and a specific activity of 4.16±2.21 Ci/μmol at the end of bombardment (n=4). PET studies in the baboon revealed initial rapid and high uptake and initial rapid clearance followed by slow clearance of carbon-11 from the brain with no difference between brain regions. The brain kinetics was not affected by co-injection of unlabeled letrozole (0.1 mg/kg). The free fraction of letrozole in plasma was 48.9% and log D was 1.84. Conclusion [11C-cyano]Letrozole is readily synthesized via a palladium catalyzed coupling reaction with [11C]cyanide. Although it is unsuitable as a PET radiotracer for brain aromatase as revealed by the absence of regional specificity and saturability in brain regions, such as amygdala, which are known to contain

  16. Uso de inibidores da aromatase no tratamento do câncer de mama e osteoporose = The use of aromatase inhibitors for breast cancer treatment and osteoporosis

    Directory of Open Access Journals (Sweden)

    Cassol, Lina Barbosa

    2005-01-01

    Conclusão: Estratégias diagnósticas, preventivas e, eventualmente, terapêuticas de osteoporose devem ser empregadas precocemente em pacientes com câncer de mama tratadas com inibidores da aromatase

  17. Aromatase inhibitors with or without gonadotropin-releasing hormone analogue in metastatic male breast cancer: a case series

    Science.gov (United States)

    Zagouri, F; Sergentanis, T N; Koutoulidis, V; Sparber, C; Steger, G G; Dubsky, P; Zografos, G C; Psaltopoulou, T; Gnant, M; Dimopoulos, M-A; Bartsch, R

    2013-01-01

    Background: Data regarding the safety and effectiveness of aromatase inhibitors (AIs) as monotherapy or combined with gonadotropin-releasing hormone (GnRH) analogue in male breast cancer are scarce. Methods: In this retrospective chart review, cases of male breast cancer patients treated with AIs with or without a GnRH analogue were evaluated. Results: Twenty-three men were included into this case series. Aromatase inhibitors in combination with or without a GnRH analogue were given as first-line therapy in 60.9% and as second-line therapy in 39.1% of patients, respectively. All patients had visceral metastases, whereas in five of them bone lesions coexisted. In all cases AIs were tolerated well, and no case of grade 3 and 4 adverse events was reported. A partial response was observed in 26.1% of patients and stable disease in 56.5%. Median overall survival (OS) was 39 months and median progression-free survival (PFS) was 13 months. Regarding OS and PFS, no significant effects of GnRH analogue co-administration or type of AI were noted. Conclusion: Our study shows that AIs with or without GnRH analogues may represent an effective and safe treatment option for hormone-receptor positive, pretreated, metastatic, male breast cancer patients. PMID:23722469

  18. Effects of the aromatase inhibitor Letrozole on serum immunoglobulin and lysozyme levels in immunized rainbow trout (Oncorhynchus mykiss Walbaum females

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    Paria Akbary

    2013-12-01

    Full Text Available Letrozole is a synthetic aromatase inhibitor and interfere in the committed step in the synthesis of endogenous estrogens from androgens. Also estrogens regulate the immune system in teleost. Changes of 17- β- esrtradiol (E2, serum immunoglobulin and lysozyme levels were measured using a method based on the ability of lysozyme to lyse the bacterium Micrococcus lysodeikticus, enzyme-linked immunosorbent assay (ELISA and ELISA respectively. Twelve broodstocks were injected weekly with 2.5 mg kg-1 letrozole (an endocrine disrupter component two months before spawning season and vaccinated intraperitoneally (i.p with a bacterin (inactivated L. garviae one month before spawning. Twelve broodstocks for vaccination and twelve female rainbow trout as control group were also immiunised (i.p with the bacterin and injected (i.p with PBS, respectively. In the group received 2.5 mg AI kg-1 per week, serum E2 levels were significantly lower than that of other groups. Total immunoglobulin level and lysozyme activity were significantly higher in the parents received 2.5 mg kg-1 per week and were immunized with 10-9 cells ml-1 Lactococcus garvieae  compared to the group which immunized with L. garvieae and the control (non- immunized. The present study, suggests that aromatase inhibitors such as letrozole may be a potential tool to regulate the synthesis of E2, is involved in the hormone- immune system interaction in rainbow trout.

  19. A systematic review and methodological evaluation of published cost-effectiveness analyses of aromatase inhibitors versus tamoxifen in early stage breast cancer.

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    Ava A John-Baptiste

    Full Text Available BACKGROUND: A key priority in developing policies for providing affordable cancer care is measuring the value for money of new therapies using cost-effectiveness analyses (CEAs. For CEA to be useful it should focus on relevant outcomes and include thorough investigation of uncertainty. Randomized controlled trials (RCTs of five years of aromatase inhibitors (AI versus five years of tamoxifen in the treatment of post-menopausal women with early stage breast cancer, show benefit of AI in terms of disease free survival (DFS but not overall survival (OS and indicate higher risk of fracture with AI. Policy-relevant CEA of AI versus tamoxifen should focus on OS and include analysis of uncertainty over key assumptions. METHODS: We conducted a systematic review of published CEAs comparing an AI to tamoxifen. We searched Ovid MEDLINE, EMBASE, PsychINFO, and the Cochrane Database of Systematic Reviews without language restrictions. We selected CEAs with outcomes expressed as cost per life year or cost per quality adjusted life year (QALY. We assessed quality using the Neumann checklist. Using structured forms two abstractors collected descriptive information, sources of data, baseline assumptions on effectiveness and adverse events, and recorded approaches to assessing parameter uncertainty, methodological uncertainty, and structural uncertainty. RESULTS: We identified 1,622 citations and 18 studies met inclusion criteria. All CE estimates assumed a survival benefit for aromatase inhibitors. Twelve studies performed sensitivity analysis on the risk of adverse events and 7 assumed no additional mortality risk with any adverse event. Sub-group analysis was limited; 6 studies examined older women, 2 examined women with low recurrence risk, and 1 examined women with multiple comorbidities. CONCLUSION: Published CEAs comparing AIs to tamoxifen assumed an OS benefit though none has been shown in RCTs, leading to an overestimate of the cost-effectiveness of AIs

  20. Insight into the binding interactions of CYP450 aromatase inhibitors with their target enzyme: a combined molecular docking and molecular dynamics study.

    Science.gov (United States)

    Galeazzi, Roberta; Massaccesi, Luca

    2012-03-01

    CYP450 aromatase catalyzes the terminal and rate-determining step in estrogen synthesis, the aromatization of androgens, and its inhibition is an efficient approach to treating estrogen-dependent breast cancer. Insight into the molecular basis of the interaction at the catalytic site between CYP450 aromatase inhibitors and the enzyme itself is required in order to design new and more active compounds. Hence, a combined molecular docking-molecular dynamics study was carried out to obtain the structure of the lowest energy association complexes of aromatase with some third-generation aromatase inhibitors (AIs) and with other novel synthesized letrozole-derived compounds which showed high in vitro activity. The results obtained clearly demonstrate the role of the pharmacophore groups present in the azaheterocyclic inhibitors (NSAIs)-namely the triazolic ring and highly functionalized aromatic moieties carrying H-bond donor or acceptor groups. In particular, it was pointed out that all of them can contribute to inhibition activity by interacting with residues of the catalytic cleft, but the amino acids involved are different for each compound, even if they belong to the same class. Furthermore, the azaheterocyclic group strongly coordinates with the Fe(II) of heme cysteinate in the most active NSAI complexes, while it prefers to adopt another orientation in less active ones.

  1. Gene expression alterations associated with outcome in aromatase inhibitor-treated ER+ early-stage breast cancer patients

    DEFF Research Database (Denmark)

    Gravgaard Thomsen, Karina Hedelund; Lyng, Maria Bibi; Elias, Daniel;

    2015-01-01

    Aromatase inhibitors (AI), either alone or together with chemotherapy, have become the standard adjuvant treatment for postmenopausal, estrogen receptor-positive (ER+) breast cancer. Although AIs improve overall survival, resistance is still a major clinical problem, thus additional biomarkers...... predictive of outcome of ER+ breast cancer patients treated with AIs are needed. Global gene expression analysis was performed on ER+ primary breast cancers from patients treated with adjuvant AI monotherapy; half experienced recurrence (median follow-up 6.7 years). Gene expression alterations were validated...... by qRT-PCR, and functional studies evaluating the effect of siRNA-mediated gene knockdown on cell growth were performed. Twenty-six genes, including TFF3, DACH1, RGS5, and GHR, were shown to exhibit altered expression in tumors from patients with recurrence versus non-recurrent (fold change ≥1.5, p

  2. miR-155 Drives Metabolic Reprogramming of ER+ Breast Cancer Cells Following Long-Term Estrogen Deprivation and Predicts Clinical Response to Aromatase Inhibitors.

    Science.gov (United States)

    Bacci, Marina; Giannoni, Elisa; Fearns, Antony; Ribas, Ricardo; Gao, Qiong; Taddei, Maria Letizia; Pintus, Gianfranco; Dowsett, Mitch; Isacke, Clare M; Martin, Lesley-Ann; Chiarugi, Paola; Morandi, Andrea

    2016-03-15

    Aromatase inhibitors (AI) have become the first-line endocrine treatment of choice for postmenopausal estrogen receptor-positive (ER(+)) breast cancer patients, but resistance remains a major challenge. Metabolic reprogramming is a hallmark of cancer and may contribute to drug resistance. Here, we investigated the link between altered breast cancer metabolism and AI resistance using AI-resistant and sensitive breast cancer cells, patient tumor samples, and AI-sensitive human xenografts. We found that long-term estrogen deprivation (LTED), a model of AI resistance, was associated with increased glycolysis dependency. Targeting the glycolysis-priming enzyme hexokinase-2 (HK2) in combination with the AI, letrozole, synergistically reduced cell viability in AI-sensitive models. Conversely, MCF7-LTED cells, which displayed a high degree of metabolic plasticity, switched to oxidative phosphorylation when glycolysis was impaired. This effect was ER dependent as breast cancer cells with undetectable levels of ER failed to exhibit metabolic plasticity. MCF7-LTED cells were also more motile than their parental counterparts and assumed amoeboid-like invasive abilities upon glycolysis inhibition with 2-deoxyglucose (2-DG). Mechanistic investigations further revealed an important role for miR-155 in metabolic reprogramming. Suppression of miR-155 resulted in sensitization of MCF7-LTED cells to metformin treatment and impairment of 2-DG-induced motility. Notably, high baseline miR-155 expression correlated with poor response to AI therapy in a cohort of ER(+) breast cancers treated with neoadjuvant anastrozole. These findings suggest that miR-155 represents a biomarker potentially capable of identifying the subset of breast cancers most likely to adapt to and relapse on AI therapy. PMID:26795347

  3. 芳香化酶抑制剂在男性中的应用%Application of Aromatase Inhibitors in Male Patients

    Institute of Scientific and Technical Information of China (English)

    茅江峰; 伍学焱

    2016-01-01

    芳香化酶抑制剂(Aromatase Inhibitor,AI)能抑制睾酮向雌二醇的转化,从而减少雌激素对下丘脑和垂体的负反馈抑制作用,促进垂体分泌促性腺激素。对男性部分性低促性腺激素性性腺功能减退症、男性身材矮小、肥胖相关性性腺功能减退症以及少精症,都具有一定的治疗作用。%Aromatase inhibitors (Aromatase Inhibitor, AI) can inhibit the conversion of testosterone to estradiol, thus reducing the feedback inhibition of estrogen to the hypothalamus and pituitary gland, promote the secretion of pituitary gonadotropins. And it is useful for the treatment of male sexual lower gonadotropin induced gonad hypofunction, men short stature, obesity relevance gonad hypofunction and oligospermia.

  4. Comparative study on individual aromatase inhibitors on cardiovascular safety profile: a network meta-analysis

    Directory of Open Access Journals (Sweden)

    Zhao XH

    2015-09-01

    Full Text Available Xihe Zhao,1 Lei Liu,2 Kai Li,1 Wusheng Li,1 Li Zhao,1 Huawei Zou1 1Department of Oncology, 2Department of General Surgery, Shengjing Hospital of China Medical University, Shenyang, People’s Republic of China Abstract: The third-generation aromatase inhibitors (AIs: anastrozole, letrozole, and exemestane have now become standard adjuvant endocrine treatment for postmenopausal estrogen receptor-positive breast cancer complementing chemotherapy and surgery. Because of the absence of direct head-to-head comparisons of these AIs, an indirect comparison is needed for individual treatment choice. In this network systemic assessment, the cardiovascular (CV side effects in using anastrozole, letrozole, and exemestane based on original studies on AIs vs placebo or tamoxifen were compared. We integrated all available direct and indirect evidences. The odds ratio (OR of severe CV events for indirect comparisons between exemestane and anastrozole was 1.41 (95% confidence interval [CI] =0.49–2.78, letrozole and anastrozole was 1.80 (95% CI =0.40–3.92, and letrozole and exemestane was 1.46 (95% CI =0.34–3.4. OR of subgroup risk for AIs and tamoxifen were all >1 except for thrombolism risk subgroup. The results showed that the total and severe CV risk ranking is letrozole, exemestane, and anastrozole in descending order. None of the AIs showed advantages in CV events than tamoxifen except for thromboembolism event incidence. Keywords: CV risk, breast cancer, AI, network meta-analysis

  5. Targeted Metabolomics Approach To Detect the Misuse of Steroidal Aromatase Inhibitors in Equine Sports by Biomarker Profiling.

    Science.gov (United States)

    Chan, George Ho Man; Ho, Emmie Ngai Man; Leung, David Kwan Kon; Wong, Kin Sing; Wan, Terence See Ming

    2016-01-01

    The use of anabolic androgenic steroids (AAS) is prohibited in both human and equine sports. The conventional approach in doping control testing for AAS (as well as other prohibited substances) is accomplished by the direct detection of target AAS or their characteristic metabolites in biological samples using hyphenated techniques such as gas chromatography or liquid chromatography coupled with mass spectrometry. Such an approach, however, falls short when dealing with unknown designer steroids where reference materials and their pharmacokinetics are not available. In addition, AASs with fast elimination times render the direct detection approach ineffective as the detection window is short. A targeted metabolomics approach is a plausible alternative to the conventional direct detection approach for controlling the misuse of AAS in sports. Because the administration of AAS of the same class may trigger similar physiological responses or effects in the body, it may be possible to detect such administrations by monitoring changes in the endogenous steroidal expression profile. This study attempts to evaluate the viability of using the targeted metabolomics approach to detect the administration of steroidal aromatase inhibitors, namely androst-4-ene-3,6,17-trione (6-OXO) and androsta-1,4,6-triene-3,17-dione (ATD), in horses. Total (free and conjugated) urinary concentrations of 31 endogenous steroids were determined by gas chromatography-tandem mass spectrometry for a group of 2 resting and 2 in-training thoroughbred geldings treated with either 6-OXO or ATD. Similar data were also obtained from a control (untreated) group of in-training thoroughbred geldings (n = 28). Statistical processing and chemometric procedures using principle component analysis and orthogonal projection to latent structures-discriminant analysis (OPLS-DA) have highlighted 7 potential biomarkers that could be used to differentiate urine samples obtained from the control and the treated groups

  6. Nuclear receptor co-activators and HER-2/neu are upregulated in breast cancer patients during neo-adjuvant treatment with aromatase inhibitors

    Science.gov (United States)

    Flågeng, M Hauglid; Haugan Moi, L L; Dixon, J M; Geisler, J; Lien, E A; Miller, W R; Lønning, P E; Mellgren, G

    2009-01-01

    Background: Acquired resistance to endocrine therapy in breast cancer is poorly understood. Characterisation of the molecular response to aromatase inhibitors in breast cancer tissue may provide important information regarding development of oestrogen hypersensitivity. Methods: We examined the expression levels of nuclear receptor co-regulators, the orphan nuclear receptor liver receptor homologue-1 and HER-2/neu growth factor receptor using real-time RT-PCR before and after 13–16 weeks of primary medical treatment with the aromatase inhibitors anastrozole or letrozole. Results: mRNA expression of the steroid receptor co-activator 1 (SRC-1) and peroxisome-proliferator-activated receptor γ co-activator-1α (PGC-1α) was correlated (P=0.002), and both co-activators increased during treatment in the patient group as a whole (P=0.008 and P=0.032, respectively), as well as in the subgroup of patients achieving an objective treatment response (P=0.002 and P=0.006). Although we recorded no significant change in SRC-3/amplified in breast cancer 1 level, the expression correlated positively to the change of SRC-1 (P=0.002). Notably, we recorded an increase in HER-2/neu levels during therapy in the total patient group (18 out of 26; P=0.016), but in particular among responders (15 out of 21; P=0.008). Conclusion: Our results show an upregulation of co-activator mRNA and HER-2/neu during treatment with aromatase inhibitors. These mechanisms may represent an early adaption of the breast cancer cells to oestrogen deprivation in vivo. PMID:19755984

  7. Targeted Metabolomics Approach To Detect the Misuse of Steroidal Aromatase Inhibitors in Equine Sports by Biomarker Profiling.

    Science.gov (United States)

    Chan, George Ho Man; Ho, Emmie Ngai Man; Leung, David Kwan Kon; Wong, Kin Sing; Wan, Terence See Ming

    2016-01-01

    The use of anabolic androgenic steroids (AAS) is prohibited in both human and equine sports. The conventional approach in doping control testing for AAS (as well as other prohibited substances) is accomplished by the direct detection of target AAS or their characteristic metabolites in biological samples using hyphenated techniques such as gas chromatography or liquid chromatography coupled with mass spectrometry. Such an approach, however, falls short when dealing with unknown designer steroids where reference materials and their pharmacokinetics are not available. In addition, AASs with fast elimination times render the direct detection approach ineffective as the detection window is short. A targeted metabolomics approach is a plausible alternative to the conventional direct detection approach for controlling the misuse of AAS in sports. Because the administration of AAS of the same class may trigger similar physiological responses or effects in the body, it may be possible to detect such administrations by monitoring changes in the endogenous steroidal expression profile. This study attempts to evaluate the viability of using the targeted metabolomics approach to detect the administration of steroidal aromatase inhibitors, namely androst-4-ene-3,6,17-trione (6-OXO) and androsta-1,4,6-triene-3,17-dione (ATD), in horses. Total (free and conjugated) urinary concentrations of 31 endogenous steroids were determined by gas chromatography-tandem mass spectrometry for a group of 2 resting and 2 in-training thoroughbred geldings treated with either 6-OXO or ATD. Similar data were also obtained from a control (untreated) group of in-training thoroughbred geldings (n = 28). Statistical processing and chemometric procedures using principle component analysis and orthogonal projection to latent structures-discriminant analysis (OPLS-DA) have highlighted 7 potential biomarkers that could be used to differentiate urine samples obtained from the control and the treated groups

  8. QUALITY OF LIFE OF WOMEN RECIEVING ADJUVANT HORMONAL TREATMENT FOR BREAST CANCER – A RANDOMIZED TRIAL COMPARING TAMOXIFEN WITH AROMATASE INHIBITORS

    Directory of Open Access Journals (Sweden)

    C. Volovat

    2011-05-01

    Full Text Available Purpose: The assessment and comparison of the quality of life in women with early stages breast cancer receiving Tamoxifen versus aromatase inhibitors (AINs. Methods: There were selected 223 patients treated at Center of Medical Oncology Iasi, with early stages breast cancer. The patients were divided in two groups: 115 patients receiving Tamoxifen and 107 patients receiving aromatase inhibitors. From the patients receiving AINs, 33 of patients have received Exemestane, 60 patients Letrozole and 14 patients Anastrazole. The patients have completed an EORTC C30 and EORTC BR23 questionnaire at the beginning of the treatment (after one month and after 2 years of treatment. There was calculated the difference related with global status, functional scales, emotional scales, cognitive scales and symptom scales. Results: Statistic results show a better quality of life for Anastrazole vs. Letrozole and for AINs vs. Tamoxifen group, mainly on physical scales both after 2 months and after 2 years of treatment. In the same time, the physical scales were with better results after 1 month of treatment vs. 2 years of treatment. Conclusions: Following the hormonal treatment period, there is a mild worsening of quality of life for Tamoxifen and AINs too. In the same time, the quality of life is better in the group with AINs treatment comparative with the Tamoxifen treatment.

  9. Paradoxal metabolic flare detected by 18F-fluorodeoxyglucose positron emission tomography in a patient with metastatic breast cancer treated with aromatase inhibitor and biphosphonate

    International Nuclear Information System (INIS)

    Patients with estrogen-receptor-positive advanced breast cancer are treated with endocrine therapy. The majority of breast cancer localizations show 18F-fluorodeoxyglucose (FDG) uptake at positron emission tomography (PET) examination. In these patients, the metabolic flare after therapy is common and was proposed as an index of therapy efficacy. Nevertheless, prolonged persistence of flare can lead to misinterpretation. We describe a case of a patient with invasive ductal breast cancer with bone metastases at bone scintigraphy and FDG PET scan and with expression of estrogen receptors. Initially, the patient underwent endocrine therapy in addition to a biphosfonate. Owing to progression observed in a bone scan, Tamoxifen was substituted with aromatase inhibitors. Successive bone scan examinations showed stabilization with a marked clinical improvement. A second FDG PET was performed 28 months after the first examination and showed a metabolic flare phenomenon with concomitant partial calcification of osteolitic lesions. This is an unusual case of prolonged metabolic flare

  10. Complementary or alternative medicine as possible determinant of decreased persistence to aromatase inhibitor therapy among older women with non-metastatic breast cancer.

    Directory of Open Access Journals (Sweden)

    Laetitia Huiart

    Full Text Available PURPOSE: Aromatase inhibitor therapy (AI significantly improves survival in breast cancer patients. Little is known about adherence and persistence to aromatase inhibitors and about the causes of treatment discontinuation among older women. METHODS: We constituted a cohort of women over 65 receiving a first AI therapy for breast cancer between 2006 and 2008, and followed them until June 2011. Women were selected in the population-based French National Health Insurance databases, and data was collected on the basis of pharmacy refills, medical records and face-to-face interviews. Non-persistence to treatment was defined as the first treatment discontinuation lasting more than 3 consecutive months. Time to treatment discontinuation was studied using survival analysis techniques. RESULTS: Overall among the 382 selected women, non-persistence to treatment went from 8.7% (95%CI: 6.2-12.1 at 1 year, to 15.6% (95%CI: 12.2-19.8 at 2 years, 20.8% (95%CI: 16.7-25.6 at 3 years, and 24.7% (95%CI: 19.5-31.0 at 4 years. In the multivariate analysis on a sub-sample of 233 women with available data, women using complementary or alternative medicine (CAM (HR = 3.2; 95%CI: 1.5-6.9 or suffering from comorbidities (HR = 2.2; 95%CI: 1.0-4.8 were more likely to discontinue their treatment, whereas women with polypharmacy (HR = 0.4; 95%CI: 0.2-0.91 were less likely to discontinue. In addition, 13% of the women with positive hormonal receptor status did not fill any prescription for anti-hormonal therapy. CONCLUSION: AI therapy is discontinued prematurely in a substantial portion of older patients. Some patients may use CAM not as a complementary treatment, but as an alternative to conventional medicine. Improving patient-physician communication on the use of CAM may improve hormonal therapy adherence.

  11. Germline variants in the CYP19A1 gene are related to specific adverse events in aromatase inhibitor users: a substudy of Dutch patients in the TEAM trial.

    Science.gov (United States)

    Fontein, Duveken B Y; Houtsma, Daniel; Nortier, Johan W R; Baak-Pablo, Renee F; Kranenbarg, Elma Meershoek-Klein; van der Straaten, Tahar R J H M; Putter, Hein; Seynaeve, Caroline; Gelderblom, Hans; van de Velde, Cornelis J H; Guchelaar, Henk-Jan

    2014-04-01

    Musculoskeletal adverse events (MSAEs) and vasomotor symptoms (VMSs) are known side-effects of aromatase inhibitors, and may be related to genetic variations of the aromatase gene (CYP19A1). We investigated the relationship between these specific AEs and single nucleotide polymorphisms (SNPs) in the CYP19A1 gene in postmenopausal, hormone receptor-positive early breast cancer (BC) patients treated with adjuvant exemestane for 5 years. Dutch patients who were randomized to receive 5 years of exemestane in the Tamoxifen Exemestane Adjuvant Multinational (TEAM) trial were included. A tagging-SNP approach was performed, covering 80 % of variations of the CYP19A1 gene with 30 SNPs. Logistic regression analyses were used to assess the risk of reporting VMSs or MSAEs in relation to genotypes within selected SNPs. Of 737 included patients, 281 patients reported at least one MSAE (n = 210) or VMS (n = 163). Homozygous AA genotype of rs934635 was associated with a significantly higher odds of MSAEs (multivariate odds ratio (OR) 4.66, p = 0.008) and VMSs (multivariate OR 2.78, p = 0.044). Regarding both rs1694189 and rs7176005, the homozygous variant genotypes (TT) were associated with a higher odds of VMSs, but not MSAEs (OR 1.758, p = 0.025 and OR 6.361, p = 0.021, respectively). Our exploratory analysis demonstrated that some CYP19A1 gene variations may be associated with MSAEs and/or VMSs. Specifically, patients with the homozygous variant rs934635 genotype reported more MSAEs and VMSs. Although further confirmatory studies are warranted, genomic profiling can help identify patients at an increased risk of reporting these specific AEs, potentiating further personalized BC treatment. PMID:24590773

  12. The Efficacy of Bisphosphonates in Preventing Aromatase Inhibitor Induced Bone Loss for Postmenopausal Women with Early Breast Cancer: A Systematic Review and Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Pooleriveetil Padikkal Anagha

    2014-01-01

    Full Text Available Objectives. We aim to determine the efficacy of bisphosphonates in preventing aromatase inhibitor induced bone loss (AIBL in postmenopausal women with early breast cancer. The secondary objective was to determine the safety of bisphosphonates. Materials and Methods. We searched electronic databases in a time period of 1995 January to 2013 June. Random effects meta-analytical models were used; between study heterogeneity and publication bias was assessed. Results. A total of six eligible studies reported the BMD T score of LS at 12 months and from that 3 trials of Zoledronic acid compared the change in BMD in immediate ZOL versus delayed ZOL done with subgroups like patients with normal BMD at baseline (OR = 5.402, 95% CI = 1.329–21.959, P value = 0.018 and osteopenic BMD at baseline (OR = 4.008, 95% CI = 2.249–7.143, P value = 0.0002. Both had a significant decrease in BMD that favoured the delayed ZOL; 3 trials of risedronate and ibandronate also had a significant decrease in BMD in AIs alone group. Immediate ZOL versus delayed ZOL also showed increased risk of getting an ADR in immediate group. Conclusion. Third generation bisphosphonates has an effect on BMD of patients who are on treatment of AIs in breast cancer. Furthermore, the patients treated with immediate ZOL had a significantly high risk of musculoskeletal ADR’s than patients with delayed ZOL.

  13. 芳香化酶抑制剂致骨质疏松研究进展%Research of aromatase inhibitor induced osteoporosis

    Institute of Scientific and Technical Information of China (English)

    马翠翠

    2008-01-01

    Breast cancer patients treated by aromatase inhibitor(AI) may cause ovarian failure, resulting in decreased hormone levels. Then bone loss increases, which may result in thinning bone and osteoporosis. In clinic, attention should be given and appropriate means must be chosen to prevent and treat this disease. Calcium + vitamin D, diphosphonate, selective estrogen receptor modulator, Chinese medicine are recommen-ded to reduce the incidence of esteoporosis.%乳腺癌患者服用芳香化酶抑制剂(AI)使得卵巢功能缺失导致体内雌激素水平下降,从而加速骨代谢发生骨质疏松.在临床中应给予重视并根据具体情况选择适当防治手段.推荐使用钙剂+维生素D、双膦酸盐、选择性雌激素受体调节剂、中药等药物治疗,减少骨质疏松的发病率.

  14. Serum estradiol should be monitored not only during the peri-menopausal period but also the post-menopausal period at the time of aromatase inhibitor administration

    Directory of Open Access Journals (Sweden)

    Zembutsu Hitoshi

    2009-11-01

    Full Text Available Abstract Background Aromatase inhibitor (AI therapy is being extensively used as postoperative adjuvant therapy in patients with hormone receptor-positive postmenopausal breast cancer. On the other hand, it has been reported that ovarian function was restored when AI was administered to patients who had undergone chemical menopause with chemotherapy or tamoxifen. However, there have been no reports of comprehensive monitoring of estradiol (E2 in breast cancer patients with ordinary menopause who were being administered AI. Patients and Methods Beginning in March 2008, regular monitoring of the serum levels of E2, luteinizing hormone (LH and follicle-stimulating hormone (FSH was performed for 66 postmenopausal breast cancer patients who had been started on AI therapy. For this study, we chose anastrozole as the AI. The assays of those hormones were outsourced to a commercial clinical laboratory. Results In 4 of the 66 patients the serum E2 level was decreased at 3 months but had then increased at 6 months, while in 2 other patients E2 was decreased at both 3 and 6 months but had increased at 9 months. Conclusion The results indicate that, in some breast cancer patients with ordinary menopause, E2 rebounds following AI therapy. In the future, E2 monitoring should be performed for a larger number of patients being administered AI therapy. Trial registration Our trial registration number is 19-11-1211.

  15. Inhibition of human CYP19 by azoles used as antifungal agents and aromatase inhibitors, using a new LC-MS/MS method for the analysis of estradiol product formation

    International Nuclear Information System (INIS)

    Azoles are used as fungicides in agriculture or antifungal drugs in medicine. Their therapeutic activity is based on the inhibition of fungal lanosterol-14α-demethylase (CYP51). Azoles are also used for the treatment of estrogen-dependent diseases, e.g. in breast cancer therapy. Inhibition of CYP19 (aromatase) is the working principle for tumor therapy, but is an unwanted side effect of azoles used as fungicides or antifungal drugs. The inhibition of recombinant human CYP19 by 21 azoles in use for the three different purposes was investigated using the natural substrate testosterone. Estradiol product formation was measured by a newly developed and fully validated analytical method based on liquid chromatography-tandem mass spectrometry utilizing photospray ionization (APPI). Potency of enzyme inhibition was expressed in terms of IC5 concentrations. The two cytostatic drugs fadrozole and letrozole were the most potent inhibitors. However, azoles used as fungicides, e.g. prochloraz, or as antifungal drugs, e.g. bifonazole, were almost as potent inhibitors of aromatase as the drugs used in tumor therapy. Comparison of plasma concentrations that may be reached in antifungal therapy do not allow for large safety factors for bifonazole and miconazole. The IC5 values were compared to data obtained with other substrates, such as the pseudo-substrate dibenzylfluorescein (DBF). A high correlation was found, indicating that the fluorescence assay with DBF can well be used for potency ranking and screening of chemicals for aromatase inhibition. The data for antifungal drugs show that side effects on steroid hormone synthesis in humans due to inhibition of aromatase should be considered

  16. Effects of 17α-Methyltestosterone and Aromatase Inhibitor Letrozole on Sex Reversal, Gonadal Structure, and Growth in Yellow Catfish Pelteobagrus fulvidraco.

    Science.gov (United States)

    Shen, Zhi-Gang; Fan, Qi-Xue; Yang, Wei; Zhang, Yun-Long; Wang, Han-Ping

    2015-04-01

    Monosex populations are in demand in many fish species with sexual dimorphism, e.g., better growth performance, higher gonad value, superior ornamental value. From the point of view of research, a monosex population is one of the best materials for investigating sex-determining mechanisms, sex differentiation, and sex-linked markers. Sex reversal of females (phenotypic reversal from XX female to XX male) is the first step in all-female production in species with an XX/XY system for sex determination. In the present study, masculinization of yellow catfish, a species with XX/XY sex determination, was investigated by oral administration of various doses of 17α-methyltestosterone (MT) or an aromatase inhibitor (AI) letrozole (LZ); effects on survival, growth performance, sex ratio, and changes in gonadal structure were evaluated. Three doses (20, 50, and 100 mg kg(-1) diet) of oral MT or LZ were administered to fry from 10 days post-hatching (DPH) to 59 DPH. Oral administration of MT at all doses did not significantly change the ratio of males (45.8%, 33.3%, and 50.0% respectively) compared to the control group (37.5%), while yielding intersex fish at all doses (4.2% to 8.3%). Oral administration of LZ produced a significantly higher proportion of males in all doses (75.5%, 83.3%, and 75.0%, respectively). Additionally, the lowest dose of LZ improved the growth of treated fish compared to the control, and all doses of LZ enhanced spermatogenesis in treated males. PMID:25920714

  17. Developmental regulation of aromatase activity in the rat hypothalamus

    Energy Technology Data Exchange (ETDEWEB)

    Lephart, E.D.

    1989-01-01

    The brain of all mammalian species studied thus far contain an enzymatic activity (aromatase) that catalyzes the conversion of androgens to estrogens. The activity is highest during prenatal development and contributes to the establishment of sex differences which determine adult gonadotropin secretion patterns and reproductive behavior. The studies presented in this dissertation represent a systematic effort to elucidate the mechanism(s) that control the initiation of and contribute to maintaining rat hypothalamic aromatase activity during pre- and postnatal development. Aromatase enzyme activity was measured by the {sup 3}H{sub 2}O release assay or by traditional estrogen product isolation. Brain aromatase mRNA was detected by hybridization to a cDNA encoding rat aromatase cytochrome P-450. In both males and females the time of puberty was associated with a decline in hypothalamic aromatase activity. This decline may represent a factor underlying the peri-pubertal decrease in the sensitivity to gonadal steroid feedback that accompanies completion of puberty. The results also indicate that androgens regulate brain aromatase levels during both the prepubertal and peri-pubertal stages of sexual development and that this regulation is transiently lost in young adults. Utilizing a hypothalamic organotypic culture system, aromatase activity in vitro was maintained for as long as two days. The results of studies of a variety of hormonal and metabolic regulators suggest that prenatal aromatase activity is regulated by factor(s) that function independently from the classical cyclic AMP and protein kinase C trans-membrane signaling pathways.

  18. Vitamin D and aromatase inhibitor-induced musculoskeletal symptoms (AIMSS): a phase II, double-blind, placebo-controlled, randomized trial.

    Science.gov (United States)

    Rastelli, Antonella L; Taylor, Marie E; Gao, Feng; Armamento-Villareal, Reina; Jamalabadi-Majidi, Shohreh; Napoli, Nicola; Ellis, Matthew J

    2011-08-01

    A double-blind placebo-controlled randomized phase II trial was performed to determine whether High Dose Vitamin D2 supplementation (HDD) in women receiving adjuvant anastrozole improves aromatase inhibitor-induced musculoskeletal symptoms (AIMSS) and bone loss. Patients with early breast cancer and AIMSS were stratified according to their baseline 25-hydroxy vitamin D (25OHD) level. Stratum A (20-29 ng/ml) received either HDD 50,000 IU capsules weekly for 8 weeks then monthly for 4 months or placebo. Stratum B (10-19 ng/ml) received either HDD for 16 weeks and then monthly for 2 months, or placebo. AIMSS was assessed by the Brief Pain Inventory-Short Form (BPI-SF), the Fibromyalgia Impact Questionnaire (FIQ), and the Health Assessment Questionnaire-Disability Index (HAQ-DI) at baseline, 2, 4, and 6 months. Bone Mineral Density (BMD) was measured at baseline and at 6 months. The primary endpoint of the study was the change-from-baseline musculoskeletal pain. The secondary endpoint was the percent change in BMD at 6 months. Sixty women were enrolled. Baseline characteristics were comparable between the groups. At 2 months, FIQ pain (P = 0.0045), BPI worst-pain (P = 0.04), BPI average-pain (P = 0.0067), BPI pain-severity (P = 0.04), and BPI interference (P = 0.034) scores were better in the HDD than placebo group. The positive effect of HDD on AIMSS was stronger across all time points in Stratum B than Stratum A (FIQ pain, P = 0.04; BPI average, P = 0.03; BPI severity, P = 0.03; BPI interference, P = 0.04). BMD at the femoral neck decreased in the placebo and did not change in the HDD group (P = 0.06). Weekly HDD improves AIMSS and may have a positive effect on bone health. Vitamin D supplementation strategies for breast cancer patients on AI should be further investigated. PMID:21691817

  19. Combining Computational and Biochemical Studies for a Rationale on the Anti-Aromatase Activity of Natural Polyphenols

    OpenAIRE

    Neves, Marco A. C.; Dinis, Teresa C. P.; Colombo, Giorgio; Melo, M. Luísa Sá e

    2007-01-01

    Aromatase, an enzyme of the cytochrome P450 family, is a very important pharmacological target, particularly for the treatment of breast cancer. The anti-aromatase activity of a set of natural polyphenolic compounds was evaluated in vitro. Strong aromatase inhibitors including flavones, flavanones, resveratrol, and oleuropein, with activities comparable to that of the reference anti-aromatase drug aminoglutethimide, were identified. Through the application of molecular modeling techniques bas...

  20. Origin of aromatase inhibitory activity via proteochemometric modeling.

    Science.gov (United States)

    Simeon, Saw; Spjuth, Ola; Lapins, Maris; Nabu, Sunanta; Anuwongcharoen, Nuttapat; Prachayasittikul, Virapong; Wikberg, Jarl E S; Nantasenamat, Chanin

    2016-01-01

    Aromatase, the rate-limiting enzyme that catalyzes the conversion of androgen to estrogen, plays an essential role in the development of estrogen-dependent breast cancer. Side effects due to aromatase inhibitors (AIs) necessitate the pursuit of novel inhibitor candidates with high selectivity, lower toxicity and increased potency. Designing a novel therapeutic agent against aromatase could be achieved computationally by means of ligand-based and structure-based methods. For over a decade, we have utilized both approaches to design potential AIs for which quantitative structure-activity relationships and molecular docking were used to explore inhibitory mechanisms of AIs towards aromatase. However, such approaches do not consider the effects that aromatase variants have on different AIs. In this study, proteochemometrics modeling was applied to analyze the interaction space between AIs and aromatase variants as a function of their substructural and amino acid features. Good predictive performance was achieved, as rigorously verified by 10-fold cross-validation, external validation, leave-one-compound-out cross-validation, leave-one-protein-out cross-validation and Y-scrambling tests. The investigations presented herein provide important insights into the mechanisms of aromatase inhibitory activity that could aid in the design of novel potent AIs as breast cancer therapeutic agents.

  1. Potential utility of natural products as regulators of breast cancer-associated aromatase promoters

    Directory of Open Access Journals (Sweden)

    Walker Larry A

    2011-06-01

    Full Text Available Abstract Aromatase, the key enzyme in estrogen biosynthesis, converts androstenedione to estrone and testosterone to estradiol. The enzyme is expressed in various tissues such as ovary, placenta, bone, brain, skin, and adipose tissue. Aromatase enzyme is encoded by a single gene CYP 19A1 and its expression is controlled by tissue-specific promoters. Aromatase mRNA is primarily transcribed from promoter I.4 in normal breast tissue and physiological levels of aromatase are found in breast adipose stromal fibroblasts. Under the conditions of breast cancer, as a result of the activation of a distinct set of aromatase promoters (I.3, II, and I.7 aromatase expression is enhanced leading to local overproduction of estrogen that promotes breast cancer. Aromatase is considered as a potential target for endocrine treatment of breast cancer but due to nonspecific reduction of aromatase activity in other tissues, aromatase inhibitors (AIs are associated with undesirable side effects such as bone loss, and abnormal lipid metabolism. Inhibition of aromatase expression by inactivating breast tumor-specific aromatase promoters can selectively block estrogen production at the tumor site. Although several synthetic chemical compounds and nuclear receptor ligands are known to inhibit the activity of the tumor-specific aromatase promoters, further development of more specific and efficacious drugs without adverse effects is still warranted. Plants are rich in chemopreventive agents that have a great potential to be used in chemotherapy for hormone dependent breast cancer which could serve as a source for natural AIs. In this brief review, we summarize the studies on phytochemicals such as biochanin A, genistein, quercetin, isoliquiritigenin, resveratrol, and grape seed extracts related to their effect on the activation of breast cancer-associated aromatase promoters and discuss their aromatase inhibitory potential to be used as safer chemotherapeutic agents for

  2. Modulation of Δ9-tetrahydrocannabinol-induced MCF-7 breast cancer cell growth by cyclooxygenase and aromatase

    International Nuclear Information System (INIS)

    Δ9-Tetrahydrocannabinol (Δ9-THC), a major constituent of marijuana, has been shown to stimulate the growth of MCF-7 breast cancer cells through cannabinoid receptor-independent signaling [Takeda, S., Yamaori, S., Motoya, E., Matsunaga, T., Kimura, T., Yamamoto, I., Watanabe, K., 2008. Δ9-Tetrahydrocannabinol enhances MCF-7 cell proliferation via cannabinoid receptor-independent signaling. Toxicology 245, 141-146]. Although the growth of MCF-7 cells is known to be stimulated by 17β-estradiol (E2), the interaction of Δ9-THC and E2 in MCF-7 cell growth is not fully clarified so far. In the present study, by using E2-sensitive MCF-7 cells that have expressed cyclooxygenase-2 (COX-2) and cytochrome P450 19 (aromatase), we studied whether or not COX-2 and aromatase are involved in Δ9-THC-mediated MCF-7 cell proliferation. It was shown that Δ9-THC-induced MCF-7 cell growth was inhibited by COX-2 inhibitors and was stimulated by arachidonic acid (a COX substrate). However, the growth of MCF-7 cells induced by Δ9-THC was not stimulated by PGE2, and the expression of aromatase was not affected by COX-2 inhibitors, arachidonic acid, and PGE2, suggesting that there is a disconnection between COX-2 (PGE2) and aromatase in Δ9-THC-mediated MCF-7 cell proliferation. On the other hand, Δ9-THC-induced MCF-7 cell growth was elevated by two kinds of aromatase inhibitors. Taken together with the evidence that Δ9-THC-induced MCF-7 cell proliferation was interfered with testosterone (an aromatase substrate) and exogenously provided E2, it is suggested that (1) the growth stimulatory effects of Δ9-THC are mediated by the product(s) of COX-2 except for PGE2, (2) the action of Δ9-THC is modulated by E2, and (3) COX-2 and aromatase are individually engaged in the proliferation of MCF-7 cells induced by Δ9-THC.

  3. Effect of ultra-low-dose estriol and lactobacilli vaginal tablets (Gynoflor®) on inflammatory and infectious markers of the vaginal ecosystem in postmenopausal women with breast cancer on aromatase inhibitors.

    Science.gov (United States)

    Donders, G; Bellen, G; Neven, P; Grob, P; Prasauskas, V; Buchholz, S; Ortmann, O

    2015-10-01

    This study was a detailed microscopic analysis of the changes of vaginal microflora characteristics after application of 0.03 mg estriol-lactobacilli combination on the vaginal ecosystem in postmenopausal breast cancer (BC) survivors on aromatase inhibitors (AI) with severe atrophic vaginitis. A total of 16 BC women on AI applied daily one vaginal tablet of Gynoflor® for 28 days followed by a maintenance therapy of three tablets weekly for 8 weeks. During four follow up visits a smear from the upper lateral vaginal wall was analysed by phase contrast microscopy at 400 times magnification in order to classify the lactobacillary grades(LBG), bacterial vaginosis (BV), aerobic vaginitis (AV), vulvovaginal candidosis (VVC), proportional number of leukocytes and evidence of parabasal cells and epitheliolysis. LBG improved from 81% LBG-III at entry to 88% LBG-I&IIa after 2 weeks of initial therapy, which further improved upon follow up (p lactobacilli results in rapid and enduring improvement of all markers of the vaginal microflora and epithelial vaginal cell quality in women with breast cancer on AI with dyspareunia. Candida may develop soon after its use, but rapidly disappears again upon their prolonged use. Due to its excellent safety profiles and clinical efficacy we recommend this product as first choice in women on AI with severe dyspareunia.

  4. Nicotine Blocks Brain Estrogen Synthase (Aromatase): In Vivo Positron Emission Tomography Studies in Female Baboons

    Energy Technology Data Exchange (ETDEWEB)

    Biegon, A.; Biegon, A.; Kim, S.-W.; Logan, J.; Hooker, J.M.; Muench, L.; Fowler, J.S.

    2010-01-12

    Cigarette smoking and nicotine have complex effects on human physiology and behavior, including some effects similar to those elicited by inhibition of aromatase, the last enzyme in estrogen biosynthesis. We report the first in vivo primate study to determine whether there is a direct effect of nicotine administration on brain aromatase. Brain aromatase availability was examined with positron emission tomography and the selective aromatase inhibitor [{sup 11}C]vorozole in six baboons before and after exposure to IV nicotine at .015 and .03 mg/kg. Nicotine administration produced significant, dose-dependent reductions in [{sup 11}C]vorozole binding. The amygdala and preoptic area showed the largest reductions. Plasma levels of nicotine and its major metabolite cotinine were similar to those found in cigarette smokers. Nicotine interacts in vivo with primate brain aromatase in regions involved in mood, aggression, and sexual behavior.

  5. Effects of selective serotonin reuptake inhibitors on three sex steroids in two versions of the aromatase enzyme inhibition assay and in the H295R cell assay

    DEFF Research Database (Denmark)

    Jacobsen, Naja Wessel; Hansen, Cecilie Hurup; Nellemann, Christine;

    2015-01-01

    Selective serotonin reuptake inhibitors are known to have a range of disorders that are often linked to the endocrine system e.g. hormonal imbalances, breast enlargement, sexual dysfunction, and menstrual cycle disorders. The mechanisms behind most of these disorders are not known in details...

  6. Aromatase expression increases the survival and malignancy of estrogen receptor positive breast cancer cells.

    Directory of Open Access Journals (Sweden)

    Keya De Mukhopadhyay

    Full Text Available In postmenopausal women, local estrogen produced by adipose stromal cells in the breast is believed to support estrogen receptor alpha (ERα positive breast cancer cell survival and growth. This raises the question of how the ERα positive metastatic breast cancer cells survive after they enter blood and lymph circulation, where estrogen level is very low in postmenopausal women. In this study, we show that the aromatase expression increased when ERα positive breast cancer cells were cultured in suspension. Furthermore, treatment with the aromatase substrate, testosterone, inhibited suspension culture-induced apoptosis whereas an aromatase inhibitor attenuated the effect of testosterone suggesting that suspended circulating ERα positive breast cancer cells may up-regulate intracrine estrogen activity for survival. Consistent with this notion, a moderate level of ectopic aromatase expression rendered a non-tumorigenic ERα positive breast cancer cell line not only tumorigenic but also metastatic in female nude mice without exogenous estrogen supplementation. The increased malignant phenotype was confirmed to be due to aromatase expression as the growth of orthotopic tumors regressed with systemic administration of an aromatase inhibitor. Thus, our study provides experimental evidence that aromatase plays an important role in the survival of metastatic ERα breast cancer cells by suppressing anoikis.

  7. Mitochondrial inhibitor as a new class of insulin sensitizer.

    Science.gov (United States)

    Zhang, Yong; Ye, Jianping

    2012-08-01

    Insulin resistance is a major risk factor for type 2 diabetes. AMP-activated protein kinase (AMPK) is a drug target in the improvement of insulin sensitivity. Several insulin-sensitizing medicines are able to activate AMPK through inhibition of mitochondrial functions. These drugs, such as metformin and STZ, inhibit ATP synthesis in mitochondria to raise AMP/ATP ratio in the process of AMPK activation. However, chemicals that activate AMPK directly or by activating its upstream kinases have not been approved for treatment of type 2 diabetes in humans. In an early study, we reported that berberine inhibited oxygen consumption in mitochondria, and increased AMP/ATP ratio in cells. The observation suggests an indirect mechanism for AMPK activation by berberine. Berberine stimulates glycolysis for ATP production that offsets the cell toxicity after mitochondria inhibition. The study suggests that mitochondrial inhibition is an approach for AMPK activation. In this review article, literature is critically reviewed to interpret the role of mitochondria function in the mechanism of insulin resistance, which supports that mitochondria inhibitors represent a new class of AMPK activator. The inhibitors are promising candidates for insulin sensitizers. This review provides a guideline in search for small molecule AMPK activators in the drug discovery for type 2 diabetes. PMID:23710432

  8. Screening of selected pesticides for inhibition of CYP19 aromatase activity in vitro.

    Science.gov (United States)

    Vinggaard, A M; Hnida, C; Breinholt, V; Larsen, J C

    2000-06-01

    Many pesticides are able to block or activate the steroid hormone receptors and/or to affect the levels of sex hormones, thereby potentially affecting the development or expression of the male and female reproductive system or both. This emphasizes the relevance of screening pesticides for a wide range of hormone-mimicking effects. Twenty-two pesticides were tested for their ability to affect CYP19 aromatase activity in human placental microsomes using the classical [(3)H](2)O method. Prochloraz, imazalil, propioconazole, fenarimol, triadimenol, triadimefon (all fungicides), and dicofol (an acaricide) gave rise to a statistically significant inhibition of aromatase activity. The IC(50)s of prochloraz, imazalil, propioconazole fenarimol, triadimenol, and triadimefon were calculated from dose-response curves to be 0.04, 0.34, 6.5, 10, 21 and 32 microM, respectively. The IC(50) of dicofol was greater than 50 microM. The positive control 4-hydroxyandrostendione (1 microM) caused an inhibition of aromatase activity by 74%. The compounds, which did not affect the aromatase activity, were bromopropylate, chlorfenvinphos, chlorobenzilate, chlorpyrifos, diuron, heptachlor, iprodion, linuron, pentachlorphenol, procymidon, propyzamide, quintozen, tetrachlorvinphos and tetradifon. With the purpose of comparing the results for fenarimol obtained with the microsomal system with data from an intact cell system, an aromatase assay based on JEG-3 cells was established. 4-Hydroxyandrostendione (1 microM) inhibited the aromatase activity in JEG-3 cells by 94%. The IC(50) for fenarimol in this system was 2 microM, slightly lower than that observed in the microsomal system. For the first time, fenarimol has been demonstrated to inhibit aromatase activity in human tissues and, furthermore, propioconazole, triadimefon, and triadimenol were identified as weak aromatase inhibitors. In conclusion, seven out of 22 tested pesticides turned out to be weak to moderate aromatase inhibitors in

  9. Genetics Home Reference: aromatase excess syndrome

    Science.gov (United States)

    ... males, the increased aromatase and subsequent conversion of androgens to estrogen are responsible for the gynecomastia and limited bone growth characteristic of aromatase excess syndrome . Increased estrogen in females can cause symptoms ...

  10. Effect of ultra-low-dose estriol and lactobacilli vaginal tablets (Gynoflor®) on inflammatory and infectious markers of the vaginal ecosystem in postmenopausal women with breast cancer on aromatase inhibitors.

    Science.gov (United States)

    Donders, G; Bellen, G; Neven, P; Grob, P; Prasauskas, V; Buchholz, S; Ortmann, O

    2015-10-01

    This study was a detailed microscopic analysis of the changes of vaginal microflora characteristics after application of 0.03 mg estriol-lactobacilli combination on the vaginal ecosystem in postmenopausal breast cancer (BC) survivors on aromatase inhibitors (AI) with severe atrophic vaginitis. A total of 16 BC women on AI applied daily one vaginal tablet of Gynoflor® for 28 days followed by a maintenance therapy of three tablets weekly for 8 weeks. During four follow up visits a smear from the upper lateral vaginal wall was analysed by phase contrast microscopy at 400 times magnification in order to classify the lactobacillary grades(LBG), bacterial vaginosis (BV), aerobic vaginitis (AV), vulvovaginal candidosis (VVC), proportional number of leukocytes and evidence of parabasal cells and epitheliolysis. LBG improved from 81% LBG-III at entry to 88% LBG-I&IIa after 2 weeks of initial therapy, which further improved upon follow up (p treatment (p < 0.01). While at entry most patients had moderate or severe AV, after maintenance therapy no patient except one had AV. The number of leukocytes dropped dramatically from a score of 1.78 ± 0.70 to 1.06 ± 0.25 which was consistent till the end of the study (p < 0.01). Parabasal cells dropped from a score of 3.4 ± 0.64 at entry to 1.3 ± 0.60 at the final visit (p trend < 0.01). Starting from a low rate of Candida colonisation of 2/14 (14%), a sudden rise to 7/16 (44%) occurred after 2 weeks, to return back to base levels at subsequent visits. The vaginal use of ultra-low dose estriol and lactobacilli results in rapid and enduring improvement of all markers of the vaginal microflora and epithelial vaginal cell quality in women with breast cancer on AI with dyspareunia. Candida may develop soon after its use, but rapidly disappears again upon their prolonged use. Due to its excellent safety profiles and clinical efficacy we recommend this product as first choice in women on AI with severe dyspareunia. PMID:26223323

  11. Structural basis for androgen specificity and oestrogen synthesis in human aromatase

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Debashis; Griswold, Jennifer; Erman, Mary; Pangborn, Walter; (HWMRI)

    2009-03-06

    Aromatase cytochrome P450 is the only enzyme in vertebrates known to catalyse the biosynthesis of all oestrogens from androgens. Aromatase inhibitors therefore constitute a frontline therapy for oestrogen-dependent breast cancer. In a three-step process, each step requiring 1 mol of O{sub 2}, 1 mol of NADPH, and coupling with its redox partner cytochrome P450 reductase, aromatase converts androstenedione, testosterone and 16{alpha}-hydroxytestosterone to oestrone, 17{beta}-oestradiol and 17{beta},16{alpha}-oestriol, respectively. The first two steps are C19-methyl hydroxylation steps, and the third involves the aromatization of the steroid A-ring, unique to aromatase. Whereas most P450s are not highly substrate selective, it is the hallmark androgenic specificity that sets aromatase apart. The structure of this enzyme of the endoplasmic reticulum membrane has remained unknown for decades, hindering elucidation of the biochemical mechanism. Here we present the crystal structure of human placental aromatase, the only natural mammalian, full-length P450 and P450 in hormone biosynthetic pathways to be crystallized so far. Unlike the active sites of many microsomal P450s that metabolize drugs and xenobiotics, aromatase has an androgen-specific cleft that binds the androstenedione molecule snugly. Hydrophobic and polar residues exquisitely complement the steroid backbone. The locations of catalytically important residues shed light on the reaction mechanism. The relative juxtaposition of the hydrophobic amino-terminal region and the opening to the catalytic cleft shows why membrane anchoring is necessary for the lipophilic substrates to gain access to the active site. The molecular basis for the enzyme's androgenic specificity and unique catalytic mechanism can be used for developing next-generation aromatase inhibitors.

  12. Genetics Home Reference: aromatase deficiency

    Science.gov (United States)

    ... regulating bone growth and blood sugar levels. During fetal development, aromatase converts androgens to estrogens in the placenta, ... link between the mother's blood supply and the fetus. This conversion in the ... sexual development in female fetuses. After birth, the conversion of ...

  13. Aromatase inhibitors in the treatment of endometriosis

    OpenAIRE

    Słopień, Radosław; Męczekalski, Błażej

    2016-01-01

    Endometriosis is a chronic inflammatory condition in which foci of endometrial tissue grow outside of the uterine cavity. Endometriosis was estimated to affect 176 million women of childbearing potential all over the world in 2010. The presence of extrauterine endometrial tissue is associated with pain and infertility. Typical symptoms of endometriosis include dysmenorrhoea, dyspareunia, heavy menstrual periods (menorrhagia), pelvic pain that is not related to menstrual cycles, dysuria, and c...

  14. Aromatase Inhibitors for IVF Poor Responders

    Institute of Scientific and Technical Information of China (English)

    R.B. Quintero; L.C Giudice; L.M. Westphal

    2006-01-01

    Objective To evaluate whether letrozole enhanced follicular recruitment, embryo numbers, and pregnancy rates in poor responders undergoing IVF.Methods We reviewed all IVF cycles between January 2002 and September 2003 using letrozole at Stanford University Medical Center. The entry criteria were the requirement of at least 450 IU/d of injectable gonadotropins in a prior failed cycle,which was used as a control.Results A total of 27 charts were reviewed revealing information on 54 cycles. The number of oocytes retrieved, fertilization embryo quality and embryos transferred yielded no statistical significance, although there appeared to be a trend toward higher numbers of each in the letrozole group. The clinical pregnancy rate was 9/27 (33.3%, P<0. 001)with a viable pregnancy rate of 7/27 (25.9%, P=0.002) in the letrozole cycle.Conclusion Our study is one of the first to evaluate letrozole with in vitro fertilization.Although this study showed no difference in number of oocytes or embryos, 25.9% of these "poor responding" patients achieved a pregnancy after a failed cycle at our center.

  15. Aromatase inhibitors in stimulated IVF cycles

    DEFF Research Database (Denmark)

    Papanikolaou, Evangelos G; Polyzos, Nikolaos P; Al Humaidan, Peter Samir Heskjær;

    2011-01-01

    are available regarding their efficacy in IVF stimulated cycles. Current available evidence support that letrozole may have a promising role in stimulated IVF cycles, either when administered during the follicular phase for ovarian stimulation. Especially for women with poor ovarian response, letrozole appears...... to test in the future how it may perform when used in GnRH agonist cycles. Finally administration of letrozole during luteal phase in IVF cycles offers another treatment modality for patients at high risk for OHSS taking into account that it drastically reduces estradiol levels....

  16. Novel proteasome inhibitor ixazomib sensitizes neuroblastoma cells to doxorubicin treatment

    Science.gov (United States)

    Li, Haoyu; Chen, Zhenghu; Hu, Ting; Wang, Long; Yu, Yang; Zhao, Yanling; Sun, Wenijing; Guan, Shan; Pang, Jonathan C.; Woodfield, Sarah E.; Liu, Qing; Yang, Jianhua

    2016-01-01

    Neuroblastoma (NB) is the most common extracranial malignant solid tumor seen in children and continues to lead to the death of many pediatric cancer patients. The poor outcome in high risk NB is largely attributed to the development of chemoresistant tumor cells. Doxorubicin (dox) has been widely employed as a potent anti-cancer agent in chemotherapeutic regimens; however, it also leads to chemoresistance in many cancer types including NB. Thus, developing novel small molecules that can overcome dox-induced chemoresistance is a promising strategy in cancer therapy. Here we show that the second generation proteasome inhibitor ixazomib (MLN9708) not only inhibits NB cell proliferation and induces apoptosis in vitro but also enhances dox-induced cytotoxicity in NB cells. Ixazomib inhibits dox-induced NF-κB activity and sensitizes NB cells to dox-induced apoptosis. More importantly, ixazomib demonstrated potent anti-tumor efficacy in vivo by enhancing dox-induced apoptosis in an orthotopic xenograft NB mouse model. Collectively, our study illustrates the anti-tumor efficacy of ixazomib in NB both alone and in combination with dox, suggesting that combination therapy including ixazomib with traditional therapeutic agents such as dox is a viable strategy that may achieve better outcomes for NB patients. PMID:27687684

  17. Effects of currently used pesticides in assays for estrogenicity, androgenicity, and aromatase activity in vitro

    DEFF Research Database (Denmark)

    Andersen, Helle Raun; Vinggaard, Anne; Rasmussen, Thomas Høj;

    2002-01-01

    . Prochloraz reacted as both an estrogen and an androgen antagonist. Furthermore, fenarimol and prochloraz were potent aromatase inhibitors while endosulfan was a weak inhibitor. Hence, these three pesticides possess at least three different ways to potentially disturb sex hormone actions. In addition...... assay. Vinclozolin reacted as a potent AR antagonist and dichlorvos as a very weak one. Methomyl, pirimicarb, propamocarb, and iprodion weakly stimulated aromatase activity. Although the potencies of the pesticides to react as hormone agonists or antagonists are low compared to the natural ligands...

  18. Selective inhibition of aromatase by a dihydroisocoumarin from Xyris pterygoblephara.

    Science.gov (United States)

    Endringer, Denise C; Guimarães, Keller G; Kondratyuk, Tamara P; Pezzuto, John M; Braga, Fernão C

    2008-06-01

    Aromatase is a well-established target for the chemoprevention of breast cancer. The dihydroisocoumarin (3 R,4 R)-(-)-6-methoxy-1-oxo-3-pentyl-3,4-dihydro-1 H-isochromen-4-yl acetate (1) (IC 50 = 1.6 +/- 0.1 microM), isolated from aerial parts of Xyris pterygoblephara, showed aromatase inhibitory activity. The specificity of 1 was evaluated by inhibition assays with cytochrome P450 enzymes. CYP1A1 was inhibited modestly (IC 50 = 38.0 +/- 2.0 microM), while CYP2C8 and CYP3A4 enzymes were not affected. Dihydroisocoumarin 1 showed weak antiproliferative activity against MCF-7 (IC 50 = 66.9 +/- 2.3 microM) and LNCaP (IC 50 = 57.5 +/- 2.0 microM) cells and was inactive against LU-1 and HepG2 cells in culture. These results demonstrate the potential of dihydroisocoumarin 1 to serve as a selective aromatase inhibitor. PMID:18462007

  19. Sex change in the protandrous black porgy, Acanthopagrus schlegeli: a review in gonadal development, estradiol, estrogen receptor, aromatase activity and gonadotropin.

    Science.gov (United States)

    Lee, Y H; Du, J L; Yueh, W S; Lin, B Y; Huang, J D; Lee, C Y; Lee, M F; Lau, E L; Lee, F Y; Morrey, C; Nagahama, Y; Chang, C F

    2001-12-01

    Black porgy, Acanthopagrus schlegeli Bleeker, a marine protandrous hermaphrodite, is functional male for the first two years of life but begins to sexually change to female after the third year. Testicular tissue and ovarian tissue was separated by connective tissue in the bisexual gonad. This sex pattern provides a very good model to study the endocrine mechanism of sex change in fish. The annual profiles of plasma estradiol, vitellogenin and 11-ketotestosterone concentrations in males were significantly different from those in the three-year-old females. Significantly high levels of plasma estradiol during the prespawning/spawning season and low levels of plasma 11-ketotestosterone during the spawning season were observed in the inversing females. No difference of plasma testosterone levels was observed in males and females. Oral administration of estradiol stimulated high levels of gonadal aromatase activity, plasma gonadotropin II levels and sex change in the two-year-old fish. Exogenous estradiol administered for 5-6 months induced a reversible sex change in one- and two-year-old fish. The sensitive period for estradiol treatment of sex change is from early prespawning to spawning season. Implantation with testosterone for more than a year could not block the natural sex change in three-year-old fish. Exogenous aromatase inhibitors (1,4,6-androstatriene-3,17-dione or fadrozole) suppressed aromatase activity in the brain. Oral administration with aromatase inhibitors for a year further inhibited the natural sex change in three-year-old black porgy and all fish became functional male with spermiation. Estrogen receptor alpha gene in the ovarian tissue of bisexual gonad is significantly less expressed than that in the vitellogenic ovary of female on the basis of reverse-transcription polymerase-chain reaction. There was no difference in the annual profiles of the plasma gonadotropin II levels in the males and natural inversing females. Plasma gonadotropin II

  20. Aromatase inhibitors in adjuvant endocrine treatment of breast cancer: ending the debate of sequence or upfront?——interpretation of BIG 1-98 clinical trial%乳腺癌芳香化酶抑制剂辅助内分泌治疗:序贯或初始应用争论的结束?——解读BIG 1-98临床试验

    Institute of Scientific and Technical Information of China (English)

    陈小松; 沈坤炜

    2010-01-01

    The third generation of aromatase inhibitors (AI) play an important role in the adjuvant treatment of hormonal positive postmenopausal breast cancer. Compared with tamoxifen, either upfront or sequential using of Al can both significantly improve the outcome of breast cancer patients. However, there is a continuous debate of sequence or upfront usage of Al in clinical applications. With the publication result of BIG 1-98 clinical trial and interpretation of the data, we can further recognize and optimize the usage of Al in breast cancer treatment.%第三代芳香化酶抑制剂(aromatase inhibitors,AI)在绝经后激素受体阳性乳腺癌辅助治疗中占据着重要的地位.与他莫昔芬相比,初始或序贯应用AI均可显著提高乳腺癌患者的预后,但在临床实践中,具体是选择初始还是序贯应用AI一直存在争议.随着BIG 1-98临床试验结果的公布及对其数据的解读,可进一步认识并优化AI在乳腺癌临床上的应用.

  1. Effects of transferrin on aromatase activity in porcine granulosa cells in vitro.

    Directory of Open Access Journals (Sweden)

    Małgorzata Duda

    2009-01-01

    Full Text Available Proliferating cells have an absolute requirement for iron, which is delivered by transferrin with subsequent intracellular transport via the transferrin receptor. Recent studies have reported that transferrin plays a crucial role in the local regulation of ovarian function, apart from its iron-binding characteristic. Therefore, the present study was undertaken to explore the possible role of transferrin in porcine granulosa cells function by examining its influence on aromatase activity, the most important indicator of follicular cell differentiation. In the first series of studies, pig granulosa cells isolated from small, immature follicles were cultured in the presence of transferrin alone (10 microg/ml or 100 microg/ml or with the addition of FSH (100ng/ml. The second series of studies was undertaken to determine transferrin-stimulated granulosa cells ability to aromatize exogenous testosterone (1x10(-7M. One hour after the establishment of cultures an aromatase inhibitor CGS16949A was added to test its influence on estradiol production. After 48 hours, cultures were terminated and cells were processed for immunocytochemical staining of aromatase. Media were frozen for further estradiol level analysis. Positive immunostaining for aromatase was found in all granulosa cell cultures. The intensity of immunostaining was always stronger in cultures supplemented with FSH whereas the addition of transferrin had no effect. Granulosa cells in vitro synthesized the highest amount of estradiol after the addition of FSH and exogenous testosterone as measured radioimmunologically. Concomitant treatment with FSH and transferrin caused an inhibition of FSH-stimulated aromatase activity. The production of estradiol also declined in the presence of FSH, testosterone and transferrin. This study demonstrates that transferrin had a dose-dependent inhibitory effect on FSH-stimulated aromatase activity, which was confirmed by radioimmunoassay. Our results indicate

  2. Brain aromatase (Cyp19A2) and estrogen receptors, in larvae and adult pejerrey fish Odontesthes bonariensis: Neuroanatomical and functional relations

    Science.gov (United States)

    Strobl-Mazzulla, P. H.; Lethimonier, C.; Gueguen, M.M.; Karube, M.; Fernandino, J.I.; Yoshizaki, G.; Patino, R.; Strussmann, C.A.; Kah, O.; Somoza, G.M.

    2008-01-01

    Although estrogens exert many functions on vertebrate brains, there is little information on the relationship between brain aromatase and estrogen receptors. Here, we report the cloning and characterization of two estrogen receptors, ?? and ??, in pejerrey. Both receptors' mRNAs largely overlap and were predominantly expressed in the brain, pituitary, liver, and gonads. Also brain aromatase and estrogen receptors were up-regulated in the brain of estradiol-treated males. In situ hybridization was performed to study in more detail, the distribution of the two receptors in comparison with brain aromatase mRNA in the brain of adult pejerrey. The estrogen receptors' mRNAs exhibited distinct but partially overlapping patterns of expression in the preoptic area and the mediobasal hypothalamus, as well as in the pituitary gland. Moreover, the estrogen receptor ??, but not ??, were found to be expressed in cells lining the preoptic recess, similarly as observed for brain aromatase. Finally, it was shown that the onset expression of brain aromatase and both estrogen receptors in the head of larvae preceded the morphological differentiation of the gonads. Because pejerrey sex differentiation is strongly influenced by temperature, brain aromatase expression was measured during the temperature-sensitive window and was found to be significantly higher at male-promoting temperature. Taken together these results suggest close neuroanatomical and functional relationships between brain aromatase and estrogen receptors, probably involved in the sexual differentiation of the brain and raising interesting questions on the origin (central or peripheral) of the brain aromatase substrate. ?? 2008 Elsevier Inc.

  3. EXAMINATION OF THE ANTICONVULSANT PROPERTIES OF VOLTAGE-SENSITIVE CALCIUM CHANNEL INHIBITORS IN AMYGDALA KINDLED SEIZURES

    Science.gov (United States)

    Representatives from three different classes of voltage-sensitive calcium (VSC) channel inhibitors were assessed for their protection against amygdala kindled seizures. dult male long Evans rats (n=12) were implanted with electrodes in the amygdala and were stimulated once daily ...

  4. Mesenchymal stem cells are sensitive to treatment with kinase inhibitors and ionizing radiation

    International Nuclear Information System (INIS)

    Mesenchymal stem cells (MSCs) can regenerate damaged tissues and may therefore be of importance for normal tissue repair after cancer treatment. Small molecule receptor kinase inhibitors (RKIs) have recently been introduced into cancer treatment. However, the influence of these drugs - particularly in combination with radiotherapy - on the survival of MSCs is largely unknown. The sensitivity of human primary MSCs from healthy volunteers and primary human fibroblast cells to small molecule kinase inhibitors of the vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF) and transforming growth factor β (TGFβ) receptors, as well to inhibitors of c-Kit, was examined in combination with ionizing radiation (IR); cell survival and proliferation were assessed. Expression patterns of different kinase receptors and ligands were investigated using gene arrays. MSCs were highly sensitive to the tyrosine kinase inhibitors SU14816 (imatinib) and SU11657 (sunitinib), but showed only moderate sensitivity to the selective TGFβ receptor 1 inhibitor LY2109761. Primary adult human fibroblasts were comparably resistant to all three inhibitors. The addition of IR had an additive or supra-additive effect in the MSCs, but this was not the case for differentiated fibroblasts. Proliferation was markedly reduced in MSCs following kinase inhibition, both with and without IR. Gene expression analysis revealed high levels of the PDGF α and β receptors, and lower levels of the TGFβ receptor 2 and Abl kinase. IR did not alter the expression of kinase receptors or their respective ligands in either MSCs or adult fibroblasts. These data show that MSCs are highly sensitive to RKIs and combination treatments incorporating IR. Expression analyses suggest that high levels of PDGF receptors may contribute to this effect. (orig.)

  5. Evaluation of candidate biomarkers to predict cancer cell sensitivity or resistance to PARP-1 inhibitor treatment

    DEFF Research Database (Denmark)

    Oplustilova, L.; Wolanin, K.; Bartkova, J.;

    2012-01-01

    to PARP-1i. Here we addressed these issues using PARP-1i on 20 human cell lines from carcinomas of the breast, prostate, colon, pancreas and ovary. Aberrations of the Mre11-Rad50-Nbs1 (MRN) complex sensitized cancer cells to PARP-1i, while p53 status was less predictive, even in response to PARP-1i......Impaired DNA damage response pathways may create vulnerabilities of cancer cells that can be exploited therapeutically. One such selective vulnerability is the sensitivity of BRCA1- or BRCA2-defective tumors (hence defective in DNA repair by homologous recombination, HR) to inhibitors of the poly......(ADp-ribose) polymerase-1 (PARP-1), an enzyme critical for repair pathways alternative to HR. While promising, treatment with PARP-1 inhibitors (PARP-1i) faces some hurdles, including (1) acquired resistance, (2) search for other sensitizing, non-BRCA1/2 cancer defects and (3) lack of biomarkers to predict response...

  6. Molecular simulations of aromatase reveal new insights into the mechanism of ligand binding.

    Science.gov (United States)

    Park, Jiho; Czapla, Luke; Amaro, Rommie E

    2013-08-26

    CYP19A1, also known as aromatase or estrogen synthetase, is the rate-limiting enzyme in the biosynthesis of estrogens from their corresponding androgens. Several clinically used breast cancer therapies target aromatase. In this work, explicitly solvated all-atom molecular dynamics simulations of aromatase with a model of the lipid bilayer and the transmembrane helix are performed. The dynamics of aromatase and the role of titration of an important amino acid residue involved in aromatization of androgens are investigated via two 250-ns long simulations. One simulation treats the protonated form of the catalytic aspartate 309, which appears more consistent with crystallographic data for the active site, while the simulation of the deprotonated form shows some notable conformational shifts. Ensemble-based computational solvent mapping experiments indicate possible novel druggable binding sites that could be utilized by next-generation inhibitors. In addition, the effects of protonation on the ligand positioning and channel dynamics are investigated using geometrical models that estimate the opening width of critical channels. Significant differences in channel dynamics between the protonated and deprotonated trajectories are exhibited, suggesting that the mechanism for substrate and product entry and the aromatization process may be coupled to a "locking" mechanism and channel opening. Our results may be particularly relevant in the design of novel drugs, which may be useful therapeutic treatments of cancers such as those of the breast and prostate. PMID:23927370

  7. Preparation and characterization of a chitosan-based low-pH-sensitive intelligent corrosion inhibitor

    Institute of Scientific and Technical Information of China (English)

    Yu-ning Wang; Chao-fang Dong; Da-wei Zhang; Pan-pan Ren; Li Li; Xiao-gang Li

    2015-01-01

    A chitosan (CS)-based low-pH-sensitive intelligent corrosion inhibitor was prepared by loading a pH-sensitive hydrogel with benzotriazole (BTA); the pH-sensitive hydrogel was synthetized by crosslinking CS with glutaraldehyde (GTA). Analysis by Fou-rier-transform infrared (FT–IR) spectroscopy showed that Schiff reactions occurred between amino and aldehyde groups. The swelling abil-ity of the hydrogel was investigated using a mass method, and it was observed to swell more in an acidic environment than in an alkaline en-vironment. The hydrogel’s loading capacity of BTA was approximately 0.377 g·g−1, and its release speed was faster in an acidic environment than in an alkaline environment because of its swelling behavior. The corrosion inhibition ability of the intelligent inhibitor was tested by immersion and electrochemical methods. The results showed that after 4 h of immersion, the polarization resistance (Rp) value of copper with the intelligent inhibitor was approximately twice of that of copper with BTA, indicating that the intelligent inhibitor could effectively prevent copper from corroding.

  8. Aromatase inhibition attenuates desflurane-induced preconditioning against acute myocardial infarction in male mouse heart in vivo.

    Directory of Open Access Journals (Sweden)

    Virginija Jazbutyte

    Full Text Available The volatile anesthetic desflurane (DES effectively reduces cardiac infarct size following experimental ischemia/reperfusion injury in the mouse heart. We hypothesized that endogenous estrogens play a role as mediators of desflurane-induced preconditioning against myocardial infarction. In this study, we tested the hypothesis that desflurane effects local estrogen synthesis by modulating enzyme aromatase expression and activity in the mouse heart. Aromatase metabolizes testosterone to 17β- estradiol (E2 and thereby significantly contributes to local estrogen synthesis. We tested aromatase effects in acute myocardial infarction model in male mice. The animals were randomized and subjected to four groups which were pre-treated with the selective aromatase inhibitor anastrozole (A group and DES alone (DES group or in combination (A+DES group for 15 minutes prior to surgical intervention whereas the control group received 0.9% NaCl (CON group. All animals were subjected to 45 minutes ischemia following 180 minutes reperfusion. Anastrozole blocked DES induced preconditioning and increased infarct size compared to DES alone (37.94 ± 15.5% vs. 17.1 ± 3.62% without affecting area at risk and systemic hemodynamic parameters following ischemia/reperfusion. Protein localization studies revealed that aromatase was abundant in the murine cardiovascular system with the highest expression levels in endothelial and smooth muscle cells. Desflurane application at pharmacological concentrations efficiently upregulated aromatase expression in vivo and in vitro. We conclude that desflurane efficiently regulates aromatase expression and activity which might lead to increased local estrogen synthesis and thus preserve cellular integrity and reduce cardiac damage in an acute myocardial infarction model.

  9. Unique distribution of aromatase in the human brain: in vivo studies with PET and [N-methyl-11C]vorozole.

    Science.gov (United States)

    Biegon, Anat; Kim, Sung Won; Alexoff, David L; Jayne, Millard; Carter, Pauline; Hubbard, Barbara; King, Payton; Logan, Jean; Muench, Lisa; Pareto, Deborah; Schlyer, David; Shea, Colleen; Telang, Frank; Wang, Gene-Jack; Xu, Youwen; Fowler, Joanna S

    2010-11-01

    Aromatase catalyzes the last step in estrogen biosynthesis. Brain aromatase is involved in diverse neurophysiological and behavioral functions including sexual behavior, aggression, cognition, and neuroprotection. Using positron emission tomography (PET) with the radiolabeled aromatase inhibitor [N-methyl-(11)C]vorozole, we characterized the tracer distribution and kinetics in the living human brain. Six young, healthy subjects, three men and three women, were administered the radiotracer alone on two separate occasions. Women were scanned in distinct phases of the menstrual cycle. Specificity was confirmed by pretreatment with a pharmacological (2.5 mg) dose of the aromatase inhibitor letrozole. PET data were acquired over a 90-min period and regions of interest placed over selected brain regions. Brain and plasma time activity curves, corrected for metabolites, were used to derive kinetic parameters. Distribution volume (V(T)) values in both men and women followed the following rank order: thalamus > amygdala = preoptic area > medulla (inferior olive) > accumbens, pons, occipital and temporal cortex, putamen, cerebellum, and white matter. Pretreatment with letrozole reduced V(T) in all regions, though the size of the reduction was region-dependent, ranging from ∼70% blocking in thalamus andpreoptic area to ∼10% in cerebellum. The high levels of aromatase in thalamus and medulla (inferior olive) appear to be unique to humans. These studies set the stage for the noninvasive assessment of aromatase involvement in various physiological and pathological processes affecting the human brain.

  10. Unique Distribution of Aromatase in the Human Brain: In Vivo Studies With PET and [N-Methyl-11C]Vorozole

    Energy Technology Data Exchange (ETDEWEB)

    Biegon, A.; Biegon, A.; Kim, S.W.; Alexoff, D.; Millard, J.; Carter, P.; Hubbard, B.; King, P.; Logan, J.; Muench, L.; Pareto, D.; Schlyer, D.; Shea, C.; Telang, F.; Wang, G.-J.; Xu, Y.; Fowler, J.

    2010-10-01

    Aromatase catalyzes the last step in estrogen biosynthesis. Brain aromatase is involved in diverse neurophysiological and behavioral functions including sexual behavior, aggression, cognition, and neuroprotection. Using positron emission tomography (PET) with the radiolabeled aromatase inhibitor [N-methyl-{sup 11}C]vorozole, we characterized the tracer distribution and kinetics in the living human brain. Six young, healthy subjects, three men and three women, were administered the radiotracer alone on two separate occasions. Women were scanned in distinct phases of the menstrual cycle. Specificity was confirmed by pretreatment with a pharmacological (2.5 mg) dose of the aromatase inhibitor letrozole. PET data were acquired over a 90-min period and regions of interest placed over selected brain regions. Brain and plasma time activity curves, corrected for metabolites, were used to derive kinetic parameters. Distribution volume (V{sub T}) values in both men and women followed the following rank order: thalamus > amygdala = preoptic area > medulla (inferior olive) > accumbens, pons, occipital and temporal cortex, putamen, cerebellum, and white matter. Pretreatment with letrozole reduced VT in all regions, though the size of the reduction was region-dependent, ranging from {approx}70% blocking in thalamus andpreoptic area to {approx}10% in cerebellum. The high levels of aromatase in thalamus and medulla (inferior olive) appear to be unique to humans. These studies set the stage for the noninvasive assessment of aromatase involvement in various physiological and pathological processes affecting the human brain.

  11. Crizotinib-resistant NPM-ALK mutants confer differential sensitivity to unrelated Alk inhibitors.

    Science.gov (United States)

    Ceccon, Monica; Mologni, Luca; Bisson, William; Scapozza, Leonardo; Gambacorti-Passerini, Carlo

    2013-02-01

    The dual ALK/MET inhibitor crizotinib was recently approved for the treatment of metastatic and late-stage ALK+ NSCLC, and is currently in clinical trial for other ALK-related diseases. As predicted after other tyrosine kinase inhibitors' clinical experience, the first mutations that confer resistance to crizotinib have been described in patients with non-small cell lung cancer (NSCLC) and in one patient inflammatory myofibroblastic tumor (IMT). Here, we focused our attention on the anaplastic large cell lymphoma (ALCL), where the oncogenic fusion protein NPM-ALK, responsible for 70% to 80% of cases, represents an ideal crizotinib target. We selected and characterized 2 human NPM-ALK+ ALCL cell lines, KARPAS-299 and SUP-M2, able to survive and proliferate at different crizotinib concentrations. Sequencing of ALK kinase domain revealed that a single mutation became predominant at high crizotinib doses in each cell line, namely L1196Q and I1171N in Karpas-299 and SUP-M2 cells, respectively. These mutations also conferred resistance to crizotinib in Ba/F3 cells expressing human NPM-ALK. The resistant cell populations, as well as mutated Ba/F3 cells, were characterized for sensitivity to two additional ALK inhibitors: the dual ALK/EGFR inhibitor AP26113 and NVP-TAE684. While L1196Q-positive cell lines were sensitive to both inhibitors, cells carrying I1171N substitution showed cross-resistance to all ALK inhibitors tested. This study provides potentially relevant information for the management of patients with ALCL that may relapse after crizotinib treatment.

  12. The effect of opiates on the activity of human placental aromatase/CYP19.

    Science.gov (United States)

    Zharikova, Olga L; Deshmukh, Sujal V; Kumar, Meena; Vargas, Ricardo; Nanovskaya, Tatiana N; Hankins, Gary D V; Ahmed, Mahmoud S

    2007-01-15

    Aromatase, cytochrome P450 19, is a key enzyme in the biosynthesis of estrogens by the human placenta. It is also the major placental enzyme that metabolizes the opiates L-acetylmethadol (LAAM), methadone, and buprenorphine (BUP). Methadone and BUP are used in treatment of the opiate addict and are competitive inhibitors of testosterone conversion to estradiol (E(2)) and 16alpha-hydroxytestosterone (16-OHT) to estriol (E(3)) by aromatase. The aim of this investigation is to determine the effect of 20 opiates, which can be administered to pregnant patients for therapeutic indications or abused, on E(2) and E(3) formation by placental aromatase. Data obtained indicated that the opiates increased, inhibited, or had no effect on aromatase activity. Their effect on E(3) formation was more pronounced than that on E(2) due to the lower affinity of 16-OHT than testosterone to aromatase. The K(i) values for the opiates that inhibited E(3) formation were sufentanil, 7 +/- 1 microM; LAAM, 13 +/- 8 microM; fentanyl, 25 +/- 5 microM; oxycodone, 92 +/- 22 microM; codeine, 218 +/- 69 microM; (+)-pentazocine, 225 +/- 73 microM. The agonists morphine, heroin, hydromorphone, oxymorphone, hydrocodone, propoxyphene, meperidine, levorphanol, dextrorphan, and (-)-pentazocine and the antagonists naloxone and naltrexone caused an increase in E(3) formation by 124-160% of control but had no effect on E(2) formation. Moreover, oxycodone and codeine did not inhibit E(2) formation and the IC(50) values for fentanyl, sufentanil, and (+)-pentazocine were >1000 microM. It is unlikely that the acute administration of the opiates that inhibit estrogen formation would affect maternal and/or neonatal outcome. However, the effects of abusing any of them during the entire pregnancy are unclear at this time. PMID:17118343

  13. Kinase Inhibitors that Increase the Sensitivity of Methicillin Resistant Staphylococcus aureus to β-Lactam Antibiotics

    Directory of Open Access Journals (Sweden)

    Jay Vornhagen

    2015-10-01

    Full Text Available Staphylococcus aureus are Gram-positive bacteria that are the leading cause of recurrent infections in humans that include pneumonia, bacteremia, osteomyelitis, arthritis, endocarditis, and toxic shock syndrome. The emergence of methicillin resistant S. aureus strains (MRSA has imposed a significant concern in sustained measures of treatment against these infections. Recently, MRSA strains deficient in expression of a serine/threonine kinase (Stk1 or PknB were described to exhibit increased sensitivity to β-lactam antibiotics. In this study, we screened a library consisting of 280 drug-like, low-molecular-weight compounds with the ability to inhibit protein kinases for those that increased the sensitivity of wild-type MRSA to β-lactams and then evaluated their toxicity in mice. We report the identification of four kinase inhibitors, the sulfonamides ST085384, ST085404, ST085405, and ST085399 that increased sensitivity of WT MRSA to sub-lethal concentrations of β-lactams. Furthermore, these inhibitors lacked alerting structures commonly associated with toxic effects, and toxicity was not observed with ST085384 or ST085405 in vivo in a murine model. These results suggest that kinase inhibitors may be useful in therapeutic strategies against MRSA infections.

  14. The osteoporosis knowledge and self-efficacy investigation in patients of breast cancer treated with aromatase inhibitors%乳腺癌芳香化酶抑制剂治疗患者骨质疏松知识掌握情况与自我效能水平的调查

    Institute of Scientific and Technical Information of China (English)

    倪建芬; 方群英; 吴怡; 张永芳; 蒋春儿; 江子芳

    2015-01-01

    Objective To investigate the mastering of osteoporosis knowledge and the level of self-efficacy in patients treated with aromatase inhibitors and to provide references for further preventive interventions. Methods A total of seventy five patients with breast cancer treated with aromatase inhibitors were recruited from Zhejiang Cancer Hospital using convenience sampling method. They were investigated with osteoporosis knowledge test ( OKT ) and osteoporosis self-efficacy scale ( OSES ) . Results The total score of osteoporosis knowledge was 51. 90, in which the score of risk factors of osteoporosis, exercise and calcium intake were 55. 75,50. 67 and 47. 67, respectively. The correct rate of osteoporosis knowledge was statistically different in people with different educational level and approach of health education (P<0. 05). The total score of self-efficacy and factor scores of exercise and calcium intake were (59. 80 ± 19. 88),(60. 25 ± 21. 99),(59. 35 ± 17. 76)respectively. Conclusions It is suggested to strengthen osteoporosis related health education for patients with breast cancer, and to increase their health information and beliefs, and help them to formulate health behaviors to prevent osteoporosis.%目的:探讨乳腺癌芳香化酶抑制剂治疗患者的骨质疏松知识掌握情况和自我效能的水平,为进一步预防干预提供依据。方法应用便利抽样的方法,于2014年1—6月在浙江省肿瘤医院选取符合标准的75例患者,采用骨质疏松知识问卷、骨质疏松自我效能问卷进行调查。结果75例芳香化酶抑制剂治疗的乳腺癌患者骨质疏松知识总标准分为51.90分,其中,危险因素、运动量表和钙量表的标准分分别为55.75,50.67,47.67分。不同文化程度、健康教育接受情况患者骨质疏松知识正确率差异有统计学意义(P<0.05)。75例乳腺癌患者骨质疏松自我效能总量表、运动分量表和钙摄入分量表的平均得分分别为(59.80±19

  15. Potential contribution of aromatase inhibition to the effects of nicotine and related compounds on the brain.

    Science.gov (United States)

    Biegon, Anat; Alia-Klein, Nelly; Fowler, Joanna S

    2012-01-01

    Cigarette smoking continues to be a major public health problem, and while smoking rates in men have shown some decrease over the last few decades, smoking rates among girls and young women are increasing. Practically all of the important aspects of cigarette smoking and many effects of nicotine are sexually dimorphic (reviewed by Pogun and Yararbas, 2009). Women become addicted more easily than men, while finding it harder to quit. Nicotine replacement appears to be less effective in women. This may be linked to the observation that women are more sensitive than men to non-nicotine cues or ingredients in cigarettes. The reasons for these sex differences are mostly unknown. Several lines of evidence suggest that many of the reported sex differences related to cigarette smoking may stem from the inhibitory effects of nicotine and other tobacco alkaloids on estrogen synthesis via the enzyme aromatase (cyp19a gene product). Aromatase is the last enzyme in estrogen biosynthesis, catalyzing the conversion of androgens to estrogens. This review provides a summary of experimental evidence supporting brain aromatase as a potential mediator and/or modulator of nicotine actions in the brain, contributing to sex differences in smoking behavior. Additional research on the interaction between tobacco smoke, nicotine, and aromatase may help devise new, sex specific methods for prevention and treatment of smoking addiction.

  16. Potential contribution of aromatase inhibition to the effects of nicotine and related compounds on the brain

    Directory of Open Access Journals (Sweden)

    Anat eBiegon

    2012-11-01

    Full Text Available Cigarette smoking continues to be a major public health problem, and while smoking rates in men have shown some decrease over the last few decades, smoking rates among girls and young women are increasing. Practically all of the important aspects of cigarette smoking are sexually dimorphic. Women become addicted more easily than men, while finding it harder to quit. Nicotine replacement appears to be less effective in women. This may be linked to the observation that women are more sensitive than men to non-nicotine cues or ingredients in cigarettes. The reasons for these sex differences are mostly unknown. Several lines of evidence suggest that many of the reported sex differences related to cigarette smoking may stem from the inhibitory effects of nicotine and other tobacco alkaloids on estrogen synthesis via the enzyme aromatase (cyp19a gene product. Aromatase is the last enzyme in estrogen biosynthesis, catalyzing the conversion of androgens to estrogens. This review provides a summary of experimental evidence supporting brain aromatase as a potential mediator and/or modulator of nicotine actions in the brain, contributing to sex differences in smoking behavior. Additional research on the interaction between tobacco smoke, nicotine and aromatase may help devise new, sex specific methods for prevention and treatment of smoking addiction.

  17. Investigation of aromatase inhibitory activity of metal complexes of 8-hydroxyquinoline and uracil derivatives

    Directory of Open Access Journals (Sweden)

    Prachayasittikul V

    2014-08-01

    Full Text Available Veda Prachayasittikul,1 Ratchanok Pingaew,2 Chanin Nantasenamat,3 Supaluk Prachayasittikul,3 Somsak Ruchirawat,4,5 Virapong Prachayasittikul1 1Department of Clinical Microbiology and Applied Technology, Faculty of Medical Technology, Mahidol University, Bangkok, Thailand; 2Department of Chemistry, Faculty of Science, Srinakharinwirot University, Bangkok, Thailand; 3Center of Data Mining and Biomedical Informatics, Faculty of Medical Technology, Mahidol University, Bangkok, Thailand; 4Laboratory of Medicinal Chemistry, Chulabhorn Research Institute, 5Chulabhorn Graduate Institute, Bangkok, Thailand Purpose: Estrogens play important roles in the pathogenesis and progression of breast cancer as well as estrogen-related diseases. Aromatase is a key enzyme in the rate-limiting step of estrogen production, in which its inhibition is one strategy for controlling estrogen levels to improve prognosis of estrogen-related cancers and diseases. Herein, a series of metal (Mn, Cu, and Ni complexes of 8-hydroxyquinoline (8HQ and uracil derivatives (4–9 were investigated for their aromatase inhibitory and cytotoxic activities. Methods: The aromatase inhibition assay was performed according to a Gentest™ kit using CYP19 enzyme, wherein ketoconazole and letrozole were used as reference drugs. The cytotoxicity was tested on normal embryonic lung cells (MRC-5 using 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay. Results: Only Cu complexes (6 and 9 exhibited aromatase inhibitory effect with IC50 0.30 and 1.7 µM, respectively. Cytotoxicity test against MRC-5 cells showed that Mn and Cu complexes (5 and 6, as well as free ligand 8HQ, exhibited activity with IC50 range 0.74–6.27 µM. Conclusion: Cu complexes (6 and 9 were found to act as a novel class of aromatase inhibitor. Our findings suggest that these 8HQ–Cu–uracil complexes are promising agents that could be potentially developed as a selective anticancer agent for breast cancer

  18. JAK2 inhibition sensitizes resistant EGFR-mutant lung adenocarcinoma to tyrosine kinase inhibitors.

    Science.gov (United States)

    Gao, Sizhi P; Chang, Qing; Mao, Ninghui; Daly, Laura A; Vogel, Robert; Chan, Tyler; Liu, Shu Hui; Bournazou, Eirini; Schori, Erez; Zhang, Haiying; Red Brewer, Monica; Pao, William; Morris, Luc; Ladanyi, Marc; Arcila, Maria; Manova-Todorova, Katia; de Stanchina, Elisa; Norton, Larry; Levine, Ross L; Altan-Bonnet, Gregoire; Solit, David; Zinda, Michael; Huszar, Dennis; Lyden, David; Bromberg, Jacqueline F

    2016-01-01

    Lung adenocarcinomas with mutant epidermal growth factor receptor (EGFR) respond to EGFR-targeted tyrosine kinase inhibitors (TKIs), but resistance invariably occurs. We found that the Janus kinase (JAK)/signal transduction and activator of transcription 3 (STAT3) signaling pathway was aberrantly increased in TKI-resistant EGFR-mutant non-small cell lung cancer (NSCLC) cells. JAK2 inhibition restored sensitivity to the EGFR inhibitor erlotinib in TKI-resistant cell lines and xenograft models of EGFR-mutant TKI-resistant lung cancer. JAK2 inhibition uncoupled EGFR from its negative regulator, suppressor of cytokine signaling 5 (SOCS5), consequently increasing EGFR abundance and restoring the tumor cells' dependence on EGFR signaling. Furthermore, JAK2 inhibition led to heterodimerization of mutant and wild-type EGFR subunits, the activity of which was then blocked by TKIs. Our results reveal a mechanism whereby JAK2 inhibition overcomes acquired resistance to EGFR inhibitors and support the use of combination therapy with JAK and EGFR inhibitors for the treatment of EGFR-dependent NSCLC. PMID:27025877

  19. Ligula intestinalis infection is associated with alterations of both brain and gonad aromatase expression in roach (Rutilus rutilus).

    Science.gov (United States)

    Boulange-Lecomte, C; Geraudie, P; Forget-Leray, J; Gerbron, M; Minier, C

    2011-09-01

    The tapeworm Ligula intestinalis commonly infests roach (Rutilus rutilus) and is responsible for the inhibition of gonad development. In order to better understand the effect of the plerocercoid on fish physiology, and to discriminate parasitization effects from those of endocrine-disrupting compounds (EDC), Cyp19b and Cyp19a aromatase expression was investigated by real-time quantitative polymerase chain reaction (PCR) in brain and gonads of ligulosed roach, caught from a reference site. Data were compared to reproductive and endocrine endpoints previously reported in a larger cohort study (including the sampled population of the present one), such as gonadosomatic index, Fulton index, gonadal histology, plasma sex steroid levels and brain aromatase activity. A decrease in Cyp19b expression in the brain of infected fish was demonstrated, in agreement with the reduction of aromatase activity previously described. In contrast, Cyp19a expression in the gonads appeared to be enhanced in ligulosed fish, in accordance with the presence of immature but differentiated sexual tissues. Together these results show that: (1) L. intestinalis infestation results in an alteration of aromatase expression which, in particular, may have profound effects on the fish brain; and (2) L. intestinalis infection must be considered as a major confounding factor in ecotoxicological studies using aromatase expression as an EDC biomarker. Moreover, the concordance between activity and expression--investigated for the first time in the same population--gives a functional relevance to the transcript aromatase dosage in the brain. Finally, quantitative PCR was confirmed as a sensitive approach, enabling aromatase status to be defined in the poorly developed gonads of ligulosed individuals. PMID:21062527

  20. Energy metabolism determines the sensitivity of human hepatocellular carcinoma cells to mitochondrial inhibitors and biguanide drugs.

    Science.gov (United States)

    Hsu, Chia-Chi; Wu, Ling-Chia; Hsia, Cheng-Yuan; Yin, Pen-Hui; Chi, Chin-Wen; Yeh, Tien-Shun; Lee, Hsin-Chen

    2015-09-01

    Human hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide particularly in Asia. Deregulation of cellular energetics was recently included as one of the cancer hallmarks. Compounds that target the mitochondria in cancer cells were proposed to have therapeutic potential. Biguanide drugs which inhibit mitochondrial complex I and repress mTOR signaling are clinically used to treat type 2 diabetes mellitus patients (T2DM) and were recently found to reduce the risk of HCC in T2DM patients. However, whether alteration of energy metabolism is involved in regulating the sensitivity of HCC to biguanide drugs is still unclear. In the present study, we treated four HCC cell lines with mitochondrial inhibitors (rotenone and oligomycin) and biguanide drugs (metformin and phenformin), and found that the HCC cells which had a higher mitochondrial respiration rate were more sensitive to these treatments; whereas the HCC cells which exhibited higher glycolysis were more resistant. When glucose was replaced by galactose in the medium, the altered energy metabolism from glycolysis to mitochondrial respiration in the HCC cells enhanced the cellular sensitivity to mitochondrial inhibitors and biguanides. The energy metabolism change enhanced AMP-activated protein kinase (AMPK) activation, mTOR repression and downregulation of cyclin D1 and Mcl-1 in response to the mitochondrial inhibitors and biguanides. In conclusion, our results suggest that increased mitochondrial oxidative metabolism upregulates the sensitivity of HCC to biguanide drugs. Enhancing the mitochondrial oxidative metabolism in combination with biguanide drugs may be a therapeutic strategy for HCC.

  1. Synergistic Effects of Calcineurin Inhibitors and Steroids on Steroid Sensitivity of Peripheral Blood Mononuclear Cells.

    Science.gov (United States)

    Takeuchi, Hironori; Iwamoto, Hitoshi; Nakamura, Yuki; Hirano, Toshihiko; Konno, Osamu; Kihara, Yu; Chiba, Naokazu; Yokoyama, Takayoshi; Takano, Kiminori; Toraishi, Tatsunori; Okuyama, Kiyoshi; Ikeda, Chie; Tanaka, Sachiko; Onda, Kenji; Soga, Akiko; Kikuchi, Yukiko; Kawaguchi, Takashi; Kawachi, Shigeyuki; Unezaki, Sakae; Shimazu, Motohide

    2015-02-01

    The steroid receptor (SR) complex contains FKBP51 and FKBP52, which bind to tacrolimus (TAC) and cyclophilin 40, which, in turn, bind to cyclosporine (CYA); these influence the intranuclear mobility of steroid-SR complexes. Pharmacodynamic interactions are thought to exist between steroids and calcineurin inhibitors (CNIs) on the SR complex. We examined the effect of CNIs on steroid sensitivity. Methylprednisolone (MPSL) sensitivity was estimated as the concentration inhibiting mitosis in 50% (IC50) of peripheral blood mononuclear cells and as the area under the MPSL concentration-proliferation suppressive rate curves (CPS-AUC) in 30 healthy subjects. MPSL sensitivity was compared between the additive group (AG) as the MPSL sensitivity that was a result of addition of the proliferation suppressive rate of CNIs to that of MPSL and the mixed culture group (MCG) as MPSL sensitivity of mixed culture with both MPSL and CNIs in identical patients. IC50 values of MPSL and cortisol sensitivity were examined before and 2 months after CNI administration in 23 renal transplant recipients. IC50 and CPS-AUC values of MPSL were lower in the MCG than in the AG with administration of TAC and CYA. The CPS-AUC ratio of MCG and AG was lower in the TAC group. IC50 values of MPSL and cortisol tended to be lower after administration of TAC and CYA, and a significant difference was observed in the IC50 of cortisol after TAC administration. Steroid sensitivity increased with both TAC and CYA. Furthermore, TAC had a greater effect on increasing sensitivity. Thus, concomitant administration of CNIs and steroids can increase steroid sensitivity. PMID:26858893

  2. NHE1 inhibition by amiloride- and benzoylguanidine-type compounds. Inhibitor binding loci deduced from chimeras of NHE1 homologues with endogenous differences in inhibitor sensitivity

    DEFF Research Database (Denmark)

    Pedersen, Stine F; King, Scott A; Nygaard, Eva B;

    2007-01-01

    The interaction of the ubiquitous Na(+)/H(+) exchanger, NHE1, with its commonly used inhibitors, amiloride- and benzoylguanidine (Hoechst type inhibitor (HOE))-type compounds, is incompletely understood. We previously cloned NHE1 from Amphiuma tridactylum (AtNHE1) and Pleuronectes americanus (Pa......NHE1). Although highly homologous to the amiloride- and HOE-sensitive human NHE1 (hNHE1), AtNHE1 is insensitive to HOE-type and PaNHE1 to both amiloride- and HOE-type compounds. Here we generated chimeras to "knock in" amiloride and HOE sensitivity to PaNHE1, and we thereby identified several NHE1...

  3. Mesenchymal stem cells are sensitive to treatment with kinase inhibitors and ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Nicolay, Nils H.; Debus, Juergen; Huber, Peter E. [Heidelberg University Hospital, Department of Radiation Oncology, Heidelberg (Germany); German Cancer Research Center (dkfz), Department of Molecular and Radiation Oncology, Heidelberg (Germany); Sommer, Eva; Lopez Perez, Ramon; Wirkner, Ute [German Cancer Research Center (dkfz), Department of Molecular and Radiation Oncology, Heidelberg (Germany); Bostel, Tilman [Heidelberg University Hospital, Department of Radiation Oncology, Heidelberg (Germany); Ho, Anthony D.; Saffrich, Rainer [Heidelberg University Hospital, Department of Hematology, Oncology and Rheumatology, Heidelberg (Germany); Lahn, Michael [Lilly Research Laboratories, Oncology Early Clinical Investigation, Indianapolis, IN (United States)

    2014-11-15

    Mesenchymal stem cells (MSCs) can regenerate damaged tissues and may therefore be of importance for normal tissue repair after cancer treatment. Small molecule receptor kinase inhibitors (RKIs) have recently been introduced into cancer treatment. However, the influence of these drugs - particularly in combination with radiotherapy - on the survival of MSCs is largely unknown. The sensitivity of human primary MSCs from healthy volunteers and primary human fibroblast cells to small molecule kinase inhibitors of the vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF) and transforming growth factor β (TGFβ) receptors, as well to inhibitors of c-Kit, was examined in combination with ionizing radiation (IR); cell survival and proliferation were assessed. Expression patterns of different kinase receptors and ligands were investigated using gene arrays. MSCs were highly sensitive to the tyrosine kinase inhibitors SU14816 (imatinib) and SU11657 (sunitinib), but showed only moderate sensitivity to the selective TGFβ receptor 1 inhibitor LY2109761. Primary adult human fibroblasts were comparably resistant to all three inhibitors. The addition of IR had an additive or supra-additive effect in the MSCs, but this was not the case for differentiated fibroblasts. Proliferation was markedly reduced in MSCs following kinase inhibition, both with and without IR. Gene expression analysis revealed high levels of the PDGF α and β receptors, and lower levels of the TGFβ receptor 2 and Abl kinase. IR did not alter the expression of kinase receptors or their respective ligands in either MSCs or adult fibroblasts. These data show that MSCs are highly sensitive to RKIs and combination treatments incorporating IR. Expression analyses suggest that high levels of PDGF receptors may contribute to this effect. (orig.) [German] Mesenchymale Stammzellen (MSCs) koennen die Geweberegeneration unterstuetzen und haben daher moeglicherweise eine Rolle bei der Reparatur

  4. Calcineurin inhibitors acutely improve insulin sensitivity without affecting insulin secretion in healthy human volunteers

    DEFF Research Database (Denmark)

    Øzbay, Aygen; Møller, Niels; Juhl, Claus;

    2012-01-01

    of calcineurin inhibitors (CNIs) ciclosporin (CsA) and tacrolimus (Tac) has improved the outcome of organ transplants, but complications such as new onset diabetes mellitus after transplantation (NODAT) cause impairment of survival rates. The relative contribution of each CNI to the pathogenesis and development.......047), whereas first phase and pulsatile insulin secretion were unaffected. Coinciding with the CNI induced improved insulin sensitivity, glucose oxidation rates increased, while insulin clearance rates decreased, only non-significantly. Tac singularly lowered hsCRP concentrations, otherwise no changes were...

  5. Two natural products, trans-phytol and (22E)-ergosta-6,9,22-triene-3β,5α,8α-triol, inhibit the biosynthesis of estrogen in human ovarian granulosa cells by aromatase (CYP19)

    International Nuclear Information System (INIS)

    Aromatase is the only enzyme in vertebrates to catalyze the biosynthesis of estrogens. Although inhibitors of aromatase have been developed for the treatment of estrogen-dependent breast cancer, the whole-body inhibition of aromatase causes severe adverse effects. Thus, tissue-selective aromatase inhibitors are important for the treatment of estrogen-dependent cancers. In this study, 63 natural products with diverse structures were examined for their effects on estrogen biosynthesis in human ovarian granulosa-like KGN cells. Two compounds—trans-phytol (SA-20) and (22E)-ergosta-6,9,22-triene-3β,5α,8α-triol (SA-48)—were found to potently inhibit estrogen biosynthesis (IC50: 1 μM and 0.5 μM, respectively). Both compounds decreased aromatase mRNA and protein expression levels in KGN cells, but had no effect on the aromatase catalytic activity in aromatase-overexpressing HEK293A cells and recombinant expressed aromatase. The two compounds decreased the expression of aromatase promoter I.3/II. Neither compound affected intracellular cyclic AMP (cAMP) levels, but they inhibited the phosphorylation or protein expression of cAMP response element-binding protein (CREB). The effects of these two compounds on extracellular regulated kinase (ERK), c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinases (MAPKs), and AKT/phosphoinositide 3-kinase (PI3K) pathway were examined. Inhibition of p38 MAPK could be the mechanism underpinning the actions of these compounds. Our results suggests that natural products structurally similar to SA-20 and SA-48 may be a new source of tissue-selective aromatase modulators, and that p38 MAPK is important in the basal control of aromatase in ovarian granulosa cells. SA-20 and SA-48 warrant further investigation as new pharmaceutical tools for the prevention and treatment of estrogen-dependent cancers. - Highlights: • Two natural products inhibited estrogen biosynthesis in human ovarian granulosa cells. • They inhibited

  6. Two natural products, trans-phytol and (22E)-ergosta-6,9,22-triene-3β,5α,8α-triol, inhibit the biosynthesis of estrogen in human ovarian granulosa cells by aromatase (CYP19)

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Jiajia [Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu (China); Yuan, Yun [Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu (China); School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang (China); Lu, Danfeng; Du, Baowen [Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu (China); Xiong, Liang; Shi, Jiangong [State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing (China); Yang, Lijuan [Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu (China); Liu, Wanli [MOE Key Laboratory of Protein Science, School of Life Sciences, Tsinghua University, Beijing 100084 (China); Yuan, Xiaohong [School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang (China); Zhang, Guolin, E-mail: zhanggl@cib.ac.cn [Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu (China); Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu (China); Wang, Fei, E-mail: wangfei@cib.ac.cn [Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu (China); Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu (China)

    2014-08-15

    Aromatase is the only enzyme in vertebrates to catalyze the biosynthesis of estrogens. Although inhibitors of aromatase have been developed for the treatment of estrogen-dependent breast cancer, the whole-body inhibition of aromatase causes severe adverse effects. Thus, tissue-selective aromatase inhibitors are important for the treatment of estrogen-dependent cancers. In this study, 63 natural products with diverse structures were examined for their effects on estrogen biosynthesis in human ovarian granulosa-like KGN cells. Two compounds—trans-phytol (SA-20) and (22E)-ergosta-6,9,22-triene-3β,5α,8α-triol (SA-48)—were found to potently inhibit estrogen biosynthesis (IC{sub 50}: 1 μM and 0.5 μM, respectively). Both compounds decreased aromatase mRNA and protein expression levels in KGN cells, but had no effect on the aromatase catalytic activity in aromatase-overexpressing HEK293A cells and recombinant expressed aromatase. The two compounds decreased the expression of aromatase promoter I.3/II. Neither compound affected intracellular cyclic AMP (cAMP) levels, but they inhibited the phosphorylation or protein expression of cAMP response element-binding protein (CREB). The effects of these two compounds on extracellular regulated kinase (ERK), c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinases (MAPKs), and AKT/phosphoinositide 3-kinase (PI3K) pathway were examined. Inhibition of p38 MAPK could be the mechanism underpinning the actions of these compounds. Our results suggests that natural products structurally similar to SA-20 and SA-48 may be a new source of tissue-selective aromatase modulators, and that p38 MAPK is important in the basal control of aromatase in ovarian granulosa cells. SA-20 and SA-48 warrant further investigation as new pharmaceutical tools for the prevention and treatment of estrogen-dependent cancers. - Highlights: • Two natural products inhibited estrogen biosynthesis in human ovarian granulosa cells. • They

  7. Inhibitors

    Science.gov (United States)

    ... wrong place in the body. Immune Tolerance Induction (ITI) Therapy: The goal of ITI therapy is to stop the inhibitor reaction from ... body to accept clotting factor concentrate treatments. With ITI therapy, people receive large amounts of clotting factor ...

  8. Roles of PARP inhibitor in synthetic lethality and as a sensitizer in cancer therapy

    International Nuclear Information System (INIS)

    In a search for novel chemotherapeutic targets for cancer, recent interest has focused on DNA repair pathways. Poly (ADP-ribose) polymerase (PARP)-1 is an important protein for base excision repair and inhibitors of this pathway show anti-cancer effects when used as a mono-therapy for BRCA-deficient cancers in clinical trials. The results of such studies proved the concept of ''synthetic lethality'' by targeting DNA repair pathways. Considering the action of the PARP inhibitor (PARPi) in DNA repair pathways, PARPi is also predicted to act as a sensitizer for DNA damaging agents, such as certain chemotherapeutic drugs and radiation. A number of clinical trials using PARPi in combination with existing therapies are underway. We investigated the use of PARPi as a radiosensitizer for high LET (linear energy transfer) radiation. PARPi showed the radiosensitization effect of carbon-ion radiation, and the radiosensitization effect of PARPi was attributed to a delay in the DNA damage response and double strand break processing. Via its effects on DNA repair, the PARP inhibitor might be applicable as a radiosensitizer for a wide range of therapeutic LET radiation. This study suggests that development of research into DNA repair pathways could yield still further targets for cancer therapy. (author)

  9. Melatonin modulates aromatase activity and expression in endothelial cells.

    Science.gov (United States)

    Alvarez-García, Virginia; González, Alicia; Martínez-Campa, Carlos; Alonso-González, Carolina; Cos, Samuel

    2013-05-01

    Melatonin is known to suppress the development of endocrine-responsive breast cancers by interacting with the estrogen signaling pathways. Paracrine interactions between malignant epithelial cells and proximal stromal cells are responsible for local estrogen biosynthesis. In human breast cancer cells and peritumoral adipose tissue, melatonin downregulates aromatase, which transforms androgens into estrogens. The presence of aromatase on endothelial cells indicates that endothelial cells may contribute to tumor growth by producing estrogens. Since human umbilical vein endothelial cells (HUVECs) express both aromatase and melatonin receptors, the aim of the present study was to evaluate the ability of melatonin to regulate the activity and expression of aromatase on endothelial cells, thus, modulating local estrogen biosynthesis. In the present study, we demonstrated that melatonin inhibits the growth of HUVECs and reduces the local biosynthesis of estrogens through the downregulation of aromatase. These results are supported by three lines of evidence. Firstly, 1 mM of melatonin counteracted the testosterone-induced cell proliferation of HUVECs, which is dependent on the local biosynthesis of estrogens from testosterone by the aromatase activity of the cells. Secondly, we found that 1 mM of melatonin reduced the aromatase activity of HUVECs. Finally, by real‑time RT-PCR, we demonstrated that melatonin significantly downregulated the expression of aromatase as well as its endothelial-specific aromatase promoter region I.7. We conclude that melatonin inhibits aromatase activity and expression in HUVECs by regulating gene expression of specific aromatase promoter regions, thereby reducing the local production of estrogens. PMID:23450505

  10. 芳香化酶抑制剂对暗纹东方鲀CYP19A、DMRT1基因表达及性腺分化的影响%Effect of aromatase inhibitor on expression of CYP19A, DMRT1, and gonadal sex differentiation in Takifugu obscures

    Institute of Scientific and Technical Information of China (English)

    黄波; 杨小玉; 戴奇; 汪奇; 云丹; 周忠良

    2013-01-01

      采用组织学和分子生物学方法,研究了投喂芳香化酶抑制剂来曲唑(LE)后暗纹东方(Takifugu obscures)初鲀孵仔鱼CYP19A、DMRT1基因表达以及性腺的组织学变化,以期进一步了解P450芳香化酶(P450arom)在鱼类早期性别分化过程中的作用.RT-PCR 结果显示,对照组样品 CYP19A 和 DMRT1表达显示性二态,雌性表达 CYP19A基因,雄性表达 DMRT1基因.LE 处理组在性别分化期间,雄性样品单一表达 DMRT1,雌性样品则同时表达CYP19A 和 DMRT1.qRT-PCR 结果显示: LE 处理组雌性仔鱼 CYP19A 基因表达被显著抑;虽然在仔鱼出膜后22 d(dph)的表达水平高于9 dph,但仅为同日对照组的2.11%.LE处理组雌性样品22 dph时DMRT1基因表达量上调,至150 dph时达对照组雄性水平.55 dph的性腺组织学结果表明, LE处理可导致暗纹东方稚鱼原始卵巢退化,并鲀向功能性精巢发育.150 dph的LE处理组性腺均为精巢,并与对照组精巢发育同步.结论认为,暗纹东方性腺鲀分化期间P450arom是卵巢形成和维持发育所必须的,抑制P450arom活性可导致雌性暗纹东方发生雄性化逆转.鲀%As in all other lower vertebrates, sex differentiation in fish is susceptible to environmental and steroi-dogenic stimulation or inhibition. Alteration of the sex differentiation process is possible in many fishes through the manipulation of the environment and steroid function. Some chemicals, which have androgenic or estrogenic function, are known to alter the gonadal sex in fish from female to male or vice versa if administered during the period of gonadal sex differentiation. Other than direct androgenic or estrogenic effects, there are chemicals which are capable of disrupting the enzymatic pathway of natural androgenic-estrogenic balance in fish. Among the non-steroidal aromatase inhibitors (AI), letrozole is typically used as an effective human drug in the treatment of estrogen-dependent disease, including breast

  11. The Proteasome Inhibitor Bortezomib Sensitizes AML with Myelomonocytic Differentiation to TRAIL Mediated Apoptosis

    International Nuclear Information System (INIS)

    Acute myeloid leukemia (AML) is an aggressive stem cell malignancy that is difficult to treat. There are limitations to the current treatment regimes especially after disease relapse, and therefore new therapeutic agents are urgently required which can overcome drug resistance whilst avoiding unnecessary toxicity. Among newer targeted agents, both tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) and proteasome inhibitors show particular promise. In this report we show that a combination of the proteasome inhibitor bortezomib and TRAIL is effective against AML cell lines, in particular, AML cell lines displaying myelomonocytic/monocytic phenotype (M4/M5 AML based on FAB classification), which account for 20-30% of AML cases. We show that the underlying mechanism of sensitization is at least in part due to bortezomib mediated downregulation of c-FLIP and XIAP, which is likely to be regulated by NF-κB. Blockage of NF-κB activation with BMS-345541 equally sensitized myelomonocytic AML cell lines and primary AML blasts to TRAIL

  12. The Proteasome Inhibitor Bortezomib Sensitizes AML with Myelomonocytic Differentiation to TRAIL Mediated Apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Dijk, Marianne van; Murphy, Eoin [Apoptosis Research Center, National University of Ireland, University Road, Galway (Ireland); School of Natural Sciences, National University of Ireland, University Road, Galway (Ireland); Morrell, Ruth [Apoptosis Research Center, National University of Ireland, University Road, Galway (Ireland); School of Natural Sciences, National University of Ireland, University Road, Galway (Ireland); School of Medicine, National University of Ireland, University Road, Galway (Ireland); Knapper, Steven [Department of Haematology, School of Medicine, Cardiff University, Heath Park, CF14 4XN Cardiff (United Kingdom); O' Dwyer, Michael [Apoptosis Research Center, National University of Ireland, University Road, Galway (Ireland); School of Medicine, National University of Ireland, University Road, Galway (Ireland); Samali, Afshin; Szegezdi, Eva, E-mail: eva.szegezdi@nuigalway.ie [Apoptosis Research Center, National University of Ireland, University Road, Galway (Ireland); School of Natural Sciences, National University of Ireland, University Road, Galway (Ireland)

    2011-03-15

    Acute myeloid leukemia (AML) is an aggressive stem cell malignancy that is difficult to treat. There are limitations to the current treatment regimes especially after disease relapse, and therefore new therapeutic agents are urgently required which can overcome drug resistance whilst avoiding unnecessary toxicity. Among newer targeted agents, both tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) and proteasome inhibitors show particular promise. In this report we show that a combination of the proteasome inhibitor bortezomib and TRAIL is effective against AML cell lines, in particular, AML cell lines displaying myelomonocytic/monocytic phenotype (M4/M5 AML based on FAB classification), which account for 20-30% of AML cases. We show that the underlying mechanism of sensitization is at least in part due to bortezomib mediated downregulation of c-FLIP and XIAP, which is likely to be regulated by NF-κB. Blockage of NF-κB activation with BMS-345541 equally sensitized myelomonocytic AML cell lines and primary AML blasts to TRAIL.

  13. Tumour growth environment modulates Chk1 signalling pathways and Chk1 inhibitor sensitivity

    Science.gov (United States)

    Massey, Andrew J.

    2016-01-01

    Clinical development of Chk1 inhibitors is currently focussed on evaluating activity as monotherapy and as potentiators of chemotherapy. To aid translation of pre-clinical studies, we sought to understand the effects of the tumour growth environment on Chk1 signalling and sensitivity to small molecule Chk1 inhibition. Spheroid culture altered Chk1 signalling to a more xenograft like state but decreased sensitivity to Chk1 inhibition. Growth in low serum did not alter DDR signalling but increased the sensitivity of A2058 and U2OS tumour cells to Chk1 inhibition. An analysis of the expression levels of replication associated proteins identified a correlation between Cdc6 and pChk1 (S296) as well as total Chk1 in xenograft derived samples and between Cdc6 and total Chk1 in anchorage-dependent growth derived protein samples. No apparent correlation between Chk1 or Cdc6 expression and sensitivity to Chk1 inhibition in vitro was observed. A database analysis revealed upregulation of CDC6 mRNA expression in tumour compared to normal tissue and a correlation between CDC6 and CHEK1 mRNA expression in human cancers. We suggest that Cdc6 overexpression in human tumours requires a concomitant increase in Chk1 to counterbalance the deleterious effects of origin hyperactivation-induced DNA damage. PMID:27775084

  14. The MCL-1 BH3 helix is an exclusive MCL-1 inhibitor and apoptosis sensitizer

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, Michelle L.; Fire, Emiko; Keating, Amy E.; Walensky, Loren D. (MIT); (DFCI)

    2010-08-30

    The development of selective inhibitors for discrete anti-apoptotic BCL-2 family proteins implicated in pathologic cell survival remains a formidable but pressing challenge. Such precisely tailored compounds would serve as molecular probes and targeted therapies to study and treat human diseases driven by specific anti-apoptotic blockades. In particular, MCL-1 has emerged as a major resistance factor in human cancer. By screening a library of stabilized alpha-helix of BCL-2 domains (SAHBs), we determined that the MCL-1 BH3 helix is itself a potent and exclusive MCL-1 inhibitor. X-ray crystallography and mutagenesis studies defined key binding and specificity determinants, including the capacity to harness the hydrocarbon staple to optimize affinity while preserving selectivity. MCL-1 SAHB directly targets MCL-1, neutralizes its inhibitory interaction with pro-apoptotic BAK and sensitizes cancer cells to caspase-dependent apoptosis. By leveraging nature's solution to ligand selectivity, we generated an MCL-1-specific agent that defines the structural and functional features of targeted MCL-1 inhibition.

  15. Causal reasoning identifies mechanisms of sensitivity for a novel AKT kinase inhibitor, GSK690693

    Directory of Open Access Journals (Sweden)

    Macoritto Michael

    2010-07-01

    Full Text Available Abstract Background Inappropriate activation of AKT signaling is a relatively common occurrence in human tumors, and can be caused by activation of components of, or by loss or decreased activity of inhibitors of, this signaling pathway. A novel, pan AKT kinase inhibitor, GSK690693, was developed in order to interfere with the inappropriate AKT signaling seen in these human malignancies. Causal network modeling is a systematic computational analysis that identifies upstream changes in gene regulation that can serve as explanations for observed changes in gene expression. In this study, causal network modeling is employed to elucidate mechanisms of action of GSK690693 that contribute to its observed biological effects. The mechanism of action of GSK690693 was evaluated in multiple human tumor cell lines from different tissues in 2-D cultures and xenografts using RNA expression and phosphoproteomics data. Understanding the molecular mechanism of action of novel targeted agents can enhance our understanding of various biological processes regulated by the intended target and facilitate their clinical development. Results Causal network modeling on transcriptomic and proteomic data identified molecular networks that are comprised of activated or inhibited mechanisms that could explain observed changes in the sensitive cell lines treated with GSK690693. Four networks common to all cell lines and xenografts tested were identified linking GSK690693 inhibition of AKT kinase activity to decreased proliferation. These networks included increased RB1 activity, decreased MYC activity, decreased TFRC activity, and increased FOXO1/FOXO3 activity. Conclusion AKT is involved in regulating both cell proliferation and apoptotic pathways; however, the primary effect with GSK690693 appears to be anti-proliferative in the cell lines and xenografts evaluated. Furthermore, these results indicate that anti-proliferative responses to GSK690693 in either 2-D culture or

  16. Effects of phosphodiesterase 4 inhibitor on cough response in guinea pigs sensitized and challenged with ovalbumin

    Institute of Scientific and Technical Information of China (English)

    吕寒静; 邱忠民; 魏为利; 余莉; 刘瑞麟; 张敏

    2004-01-01

    Background There is currently considerable interest in the potential value of selective inhibitors of cyclic nucleotide phosphodiesterase 4 in the treatment of asthma. However, whether they influence eosinophilic airway inflammation-associated cough remains unclear. The objective of this study was to investigate the effects of selective phosphodiesterase 4 inhibitor SB207499 on cough response and airway inflammation in guinea pigs sensitized and challenged with ovalbumin. Methods Forty sensitized guinea pigs were randomly divided into four groups: control (n=10), challenge (n=10), SB207499 (n=10) and aminophylline (n=10), then challenged with aerosol of 1% ovalbumin or saline. Two hours later, animals were intraperitoneally injected with either saline, 25 mg/kg of SB207499 or aminophylline. At the 24th hour, the injection was repeated with 2.5 mg/kg and 25 mg/kg SB207499 or aminophylline, then cough response to inhaled capsaicin and airway responsiveness to methacholine inducing a 150% of the peak airway pressure to the baseline (PC150) was measured. Finally, total cell number and differentials in bronchoalveolar lavage fluid were analysed. Results The cough frequency per 3 minutes and PC150 in the challenge group were (22±4) times/3 minutes and (198±54) μg/ml, which were significantly different from (6±2) times/3 minutes and (691±81) μg/ml in the control group (P<0.05, respectively). The injection of 25 mg/kg SB207499 significantly inhibited the increased cough response and airway hyperresponsiveness, the cough frequency and PC150 in guinea pigs were (13±2) times/3 minutes and (680±81) μg/ml (P<0.05), which differed significantly from (18±2) times/3 minutes and (400±86) μg/ml after the administration of the same dose of aminophylline (P<0.05). The inhibition of SB207499 on cough response was dose-dependent. Similarly, SB207499 decreased the total cell number and percentage of eosinophils in bronchoalveolar lavage fluid to (2.1±0.5)×106/ml and (20±5

  17. Neuroinflammation induces glial aromatase expression in the uninjured songbird brain

    Directory of Open Access Journals (Sweden)

    Saldanha Colin J

    2011-07-01

    Full Text Available Abstract Background Estrogens from peripheral sources as well as central aromatization are neuroprotective in the vertebrate brain. Under normal conditions, aromatase is only expressed in neurons, however following anoxic/ischemic or mechanical brain injury; aromatase is also found in astroglia. This increased glial aromatization and the consequent estrogen synthesis is neuroprotective and may promote neuronal survival and repair. While the effects of estradiol on neuroprotection are well studied, what induces glial aromatase expression remains unknown. Methods Adult male zebra finches (Taeniopygia guttata were given a penetrating injury to the entopallium. At several timepoints later, expression of aromatase, IL-1β-like, and IL-6-like were examined using immunohisotchemistry. A second set of zebra birds were exposed to phytohemagglutinin (PHA, an inflammatory agent, directly on the dorsal surface of the telencephalon without creating a penetrating injury. Expression of aromatase, IL-1β-like, and IL-6-like were examined using both quantitative real-time polymerase chain reaction to examine mRNA expression and immunohistochemistry to determine cellular expression. Statistical significance was determined using t-test or one-way analysis of variance followed by the Tukey Kramers post hoc test. Results Following injury in the zebra finch brain, cytokine expression occurs prior to aromatase expression. This temporal pattern suggests that cytokines may induce aromatase expression in the damaged zebra finch brain. Furthermore, evoking a neuroinflammatory response characterized by an increase in cytokine expression in the uninjured brain is sufficient to induce glial aromatase expression. Conclusions These studies are among the first to examine a neuroinflammatory response in the songbird brain following mechanical brain injury and to describe a novel neuroimmune signal to initiate aromatase expression in glia.

  18. Patient adherence to aromatase inhibitor treatment in the adjuvant setting

    OpenAIRE

    Verma, S.; Madarnas, Y.; Sehdev, S.; Martin, G; Bajcar, J.

    2011-01-01

    Improvements in adjuvant systemic therapy and detection of early disease have resulted in a decline of breast cancer death rates across all patient age groups in Canada. Non-adherence to adjuvant hormonal therapy in the setting of early breast cancer may significantly affect patient outcome. Factors associated with medication adherence are complex and may be patient-related, therapy-related, and health care provider–related. To date, there is a gap in the literature concerning a comprehensive...

  19. Aromatase Inhibitors and Other Compounds for Lowering Breast Cancer Risk

    Science.gov (United States)

    ... Cancer? Breast Cancer Colon/Rectum Cancer Lung Cancer Prostate Cancer Skin Cancer Show All Cancer Types News and Features Cancer Glossary ACS Bookstore Cancer Information Cancer Basics Cancer Prevention & Detection Signs & Symptoms of Cancer Treatments & Side Effects ...

  20. Paternal Retrieval Behavior Regulated by Brain Estrogen Synthetase (Aromatase) in Mouse Sires that Engage in Communicative Interactions with Pairmates

    Science.gov (United States)

    Akther, Shirin; Huang, Zhiqi; Liang, Mingkun; Zhong, Jing; Fakhrul, Azam A. K. M.; Yuhi, Teruko; Lopatina, Olga; Salmina, Alla B.; Yokoyama, Shigeru; Higashida, Chiharu; Tsuji, Takahiro; Matsuo, Mie; Higashida, Haruhiro

    2015-01-01

    Parental behaviors involve complex social recognition and memory processes and interactive behavior with children that can greatly facilitate healthy human family life. Fathers play a substantial role in child care in a small but significant number of mammals, including humans. However, the brain mechanism that controls male parental behavior is much less understood than that controlling female parental behavior. Fathers of non-monogamous laboratory ICR mice are an interesting model for examining the factors that influence paternal responsiveness because sires can exhibit maternal-like parental care (retrieval of pups) when separated from their pups along with their pairmates because of olfactory and auditory signals from the dams. Here we tested whether paternal behavior is related to femininity by the aromatization of testosterone. For this purpose, we measured the immunoreactivity of aromatase [cytochrome P450 family 19 (CYP19)], which synthesizes estrogen from androgen, in nine brain regions of the sire. We observed higher levels of aromatase expression in these areas of the sire brain when they engaged in communicative interactions with dams in separate cages. Interestingly, the number of nuclei with aromatase immunoreactivity in sires left together with maternal mates in the home cage after pup-removing was significantly larger than that in sires housed with a whole family. The capacity of sires to retrieve pups was increased following a period of 5 days spent with the pups as a whole family after parturition, whereas the acquisition of this ability was suppressed in sires treated daily with an aromatase inhibitor. The results demonstrate that the dam significantly stimulates aromatase in the male brain and that the presence of the pups has an inhibitory effect on this increase. These results also suggest that brain aromatization regulates the initiation, development, and maintenance of paternal behavior in the ICR male mice. PMID:26696812

  1. Human intestinal acyl-CoA synthetase 5 is sensitive to the inhibitor triacsin C

    Institute of Scientific and Technical Information of China (English)

    Elke Kaemmerer; Anne Peuscher; Andrea Reinartz; Christian Liedtke; Ralf Weiskirchen; Jürgen Kopitz; Nikolaus Gassler

    2011-01-01

    AIM: To investigate whether human acyl-CoA synthetase 5 (ACSL5) is sensitive to the ACSL inhibitor triacsin C.METHODS: The ACSL isoforms ACSL1 and ACSL5 from rat as well as human ACSL5 were cloned and recombinantly expressed as 6xHis-tagged enzymes. Ni2+-affinity purified recombinant enzymes were assayed at pH 7.5 or pH 9.5 in the presence or absence of triacsin C. In addition, ACSL5 transfected CaCo2 cells and intestinal human mucosa were monitored. ACSL5 expression in cellular systems was verified using Western blot and immunofluorescence.The ACSL assay mix included TrisHCl (pH 7.4), ATP, CoA, EDTA, DTT, MgCl2, [9,10-3H] palmitic acid, and triton X-100. The 200 μL reaction was initiated with the addition of solubilized, purified recombinant proteins or cellular lysates. Reactions were terminated after 10, 30 or 60 min of incubation with Doles medium.RESULTS: Expression of soluble recombinant ACSL pro-teins was found after incubation with isopropyl beta-D-1-thiogalactopyranoside and after ultracentrifugatio these were further purified to near homogeneity with Ni2+-affinity chromatography. Triacsin C selectively and strongly inhibited recombinant human ACSL5 protein at pH 7.5 and pH 9.5, as well as recombinant rat ACSL1 (sensitive control), but not recombinant rat ACSL5 (insensitive control). The IC50 for human ACSL5 was about 10 μmol/L. The inhibitory triacsin C effect was similar for different incubation times (10, 30 and 60 min) and was not modified by the N- or C-terminal location of the 6xHis-tag. In order to evaluate ACSL5 sensitivity to triacsin C in a cellular environment, stable human ACSL5 CaCo2 transfectants and mechanically dissected normal human intestinal mucosa with high physiological expression of ACSL5 were analyzed. In both models, ACSL5 peak activity was found at pH 7.5 and pH 9.5, corresponding to the properties of recombinant human ACSL5 protein. In the presence of triacsin C (25 μmol/L), total ACSL activity was dramatically diminished in

  2. Development of potent autophagy inhibitors that sensitize oncogenic BRAF V600E mutant melanoma tumor cells to vemurafenib.

    Science.gov (United States)

    Goodall, Megan L; Wang, Tong; Martin, Katie R; Kortus, Matthew G; Kauffman, Audra L; Trent, Jeffrey M; Gately, Stephen; MacKeigan, Jeffrey P

    2014-06-01

    Autophagy is a dynamic cell survival mechanism by which a double-membrane vesicle, or autophagosome, sequesters portions of the cytosol for delivery to the lysosome for recycling. This process can be inhibited using the antimalarial agent chloroquine (CQ), which impairs lysosomal function and prevents autophagosome turnover. Despite its activity, CQ is a relatively inadequate inhibitor that requires high concentrations to disrupt autophagy, highlighting the need for improved small molecules. To address this, we screened a panel of antimalarial agents for autophagy inhibition and chemically synthesized a novel series of acridine and tetrahydroacridine derivatives. Structure-activity relationship studies of the acridine ring led to the discovery of VATG-027 as a potent autophagy inhibitor with a high cytotoxicity profile. In contrast, the tetrahydroacridine VATG-032 showed remarkably little cytotoxicity while still maintaining autophagy inhibition activity, suggesting that both compounds act as autophagy inhibitors with differential effects on cell viability. Further, knockdown of autophagy-related genes showed no effect on cell viability, demonstrating that the ability to inhibit autophagy is separate from the compound cytotoxicity profiles. Next, we determined that both inhibitors function through lysosomal deacidification mechanisms and ultimately disrupt autophagosome turnover. To evaluate the genetic context in which these lysosomotropic inhibitors may be effective, they were tested in patient-derived melanoma cell lines driven by oncogenic BRAF (v-raf murine sarcoma viral oncogene homolog B). We discovered that both inhibitors sensitized melanoma cells to the BRAF V600E inhibitor vemurafenib. Overall, these autophagy inhibitors provide a means to effectively block autophagy and have the potential to sensitize mutant BRAF melanomas to first-line therapies.

  3. The dipeptidyl peptidase-4 inhibitor vildagliptin improves beta-cell function and insulin sensitivity in subjects with impaired fasting glucose

    DEFF Research Database (Denmark)

    Utzschneider, Kristina M; Tong, Jenny; Montgomery, Brenda;

    2007-01-01

    OBJECTIVE: To evaluate the effect of treatment with the dipeptidyl peptidase (DPP)-4 inhibitor vildagliptin on insulin sensitivity and beta-cell function in subjects with impaired fasting glucose (IFG). RESEARCH DESIGN AND METHODS: A total of 22 subjects with IFG (11 female and 11 male, mean +/- ...

  4. The effect of free radical inhibitor on the sensitized radiation crosslinking and thermal processing stabilization of polyurethane shape memory polymers

    International Nuclear Information System (INIS)

    The effects of free radical inhibitor on the electron beam crosslinking and thermal processing stabilization of novel radiation crosslinkable polyurethane shape memory polymers (SMPs) blended with acrylic radiation sensitizers have been determined. The SMPs in this study possess novel processing capabilities—that is, the ability to be melt processed into complex geometries as thermoplastics and crosslinked in a secondary step using electron beam irradiation. To increase susceptibility to radiation crosslinking, the radiation sensitizer pentaerythritol triacrylate (PETA) was solution blended with thermoplastic polyurethane SMPs made from 2-butene-1,4-diol and trimethylhexamethylene diisocyanate (TMHDI). Because the thermoplastic melt processing methods such as injection molding are often carried out at elevated temperatures, sensitizer thermal instability is a major processing concern. Free radical inhibitor can be added to provide thermal stabilization; however, inhibitor can also undesirably inhibit radiation crosslinking. In this study, we quantified both the thermal stabilization and radiation crosslinking inhibition effects of the inhibitor 1,4-benzoquinone (BQ) on polyurethane SMPs blended with PETA. Sol/gel analysis of irradiated samples showed that the inhibitor had little to no inverse effects on gel fraction at concentrations of 0–10,000 ppm, and dynamic mechanical analysis showed only a slight negative correlation between BQ composition and rubbery modulus. The 1,4-benzoquinone was also highly effective in thermally stabilizing the acrylic sensitizers. The polymer blends could be heated to 150 °C for up to 5 h or to 125 °C for up to 24 h if stabilized with 10,000 ppm BQ and could also be heated to 125 °C for up to 5 h if stabilized with 1000 ppm BQ without sensitizer reaction occurring. We believe this study provides significant insight into methods for manipulation of the competing mechanisms of radiation crosslinking and thermal stabilization of

  5. 他莫昔芬治疗芳香化酶抑制剂耐药的激素受体阳性绝经后转移性乳腺癌患者的临床研究%Clinical observation of tamoxifen in hormone receptor - positive postmenopausal patients with metastatic breast cancer failing to Aromatase inhibitors

    Institute of Scientific and Technical Information of China (English)

    童刚领; 李柱; 农巧红; 何艳玲; 申东兰; 王树滨

    2015-01-01

    Objective:To investigate the curative effect and safety of tamoxifen in hormone receptor - positive (HR + )postmenopausal patients with metastatic breast cancer(MBC)failing to Aromatase inhibitors(AIs). Meth-ods:Retrospectively analyzed clinical data of 30 patients with HR + postmenopausal MBC treated with tamoxifen after AIs resistance. The endpoints were response rate(RR),clinical benefit rate(CBR),time of tumor progression(TTP) and safety. Results:In 30 patients,the patients who acquired CR,PR and SD were 1,9 and 15. The RR and CBR were 33. 3% and 50% . The median TTP was 6. 1 months. The RR and CBR in 23 cases with bone and/ or soft tissue me-tastasis and 7 cases of liver and/ or pulmonary metastasis were 34. 8% ,52. 2% and 28. 6% ,42. 8% . The median TTP were 7. 3 and 4. 8 months in two groups(P = 0. 019). The most common adverse reactions were hot flashes,vaginal dryness,vaginal discharge,vaginal bleeding,nausea,vomiting,diarrhea and so on. Most side effects were grade Ⅰ orⅡ on the WHO scale. Conclusion:Treatment with tamoxifen in AIs resistant HR + postmenopausal patients with MBC is safe and effective,can improve prognosis of patients.%目的:探讨他莫昔芬治疗芳香化酶抑制剂(AIs)耐药的激素受体阳性(HR +)绝经后转移性乳腺癌(MBC)患者的疗效和安全性。方法:回顾性分析他莫昔芬治疗 AIs 耐药的30例 HR +绝经后 MBC 患者的临床资料,观察终点为缓解率(RR)、临床获益率(CBR)、疾病进展时间(TTP)和安全性。结果:30例患者中,CR 1例,PR 9例,SD 15例,RR 为33.3%,CBR 为50%,中位 TTP 6.1个月。23例骨和/或软组织转移患者中,RR为34.8%,CBR 为52.2%,中位 TTP 7.3 个月;7例肝脏和/或肺部转移患者中,RR 为28.6%,CBR 为42.8%,中位 TTP 4.8 个月(P =0.019)。不良反应多为面部潮红、阴道干燥、白带增多、阴道出血、恶心、呕吐、腹泻等,均为 I、II 级

  6. Cytochrome P450 aromatase expression in human seminoma

    OpenAIRE

    Montanaro Daniela; Aquila Saveria; Romeo Francesco; Rago Vittoria; Andò Sebastiano; Carpino Amalia

    2005-01-01

    Abstract Background The enzyme cytochrome P450 aromatase, catalysing the conversion of androgens into estrogens, has been detected in normal human testicular cells suggesting a physiological role of local estrogen biosynthesis on spermatogenesis control. Estrogens, regulating cell growth and apoptosis, can also be involved in tumorigenesis process, but the possible link between estrogens and testicular neoplastic process is, up to now, scarcely known. This study examined aromatase expression ...

  7. MiR-200c regulates Noxa expression and sensitivity to proteasomal inhibitors.

    Directory of Open Access Journals (Sweden)

    Mikael Lerner

    Full Text Available The pro-apoptotic p53 target Noxa is a BH3-only protein that antagonizes the function of selected anti-apoptotic Bcl-2 family members. While much is known regarding the transcriptional regulation of Noxa, its posttranscriptional regulation remains relatively unstudied. In this study, we therefore investigated whether Noxa is regulated by microRNAs. Using a screen combining luciferase reporters, bioinformatic target prediction analysis and microRNA expression profiling, we identified miR-200c as a negative regulator of Noxa expression. MiR-200c was shown to repress basal expression of Noxa, as well as Noxa expression induced by various stimuli, including proteasomal inhibition. Luciferase reporter experiments furthermore defined one miR-200c target site in the Noxa 3'UTR that is essential for this direct regulation. In spite of the miR-200c:Noxa interaction, miR-200c overexpression led to increased sensitivity to the clinically used proteasomal inhibitor bortezomib in several cell lines. This apparently contradictory finding was reconciled by the fact that in cells devoid of Noxa expression, miR-200c overexpression had an even more pronounced positive effect on apoptosis induced by proteasomal inhibition. Together, our data define miR-200c as a potentiator of bortezomib-induced cell death. At the same time, we show that miR-200c is a novel negative regulator of the pro-apoptotic Bcl-2 family member Noxa.

  8. Medial Amygdalar Aromatase Neurons Regulate Aggression in Both Sexes

    Directory of Open Access Journals (Sweden)

    Elizabeth K. Unger

    2015-02-01

    Full Text Available Aromatase-expressing neuroendocrine neurons in the vertebrate male brain synthesize estradiol from circulating testosterone. This locally produced estradiol controls neural circuits underlying courtship vocalization, mating, aggression, and territory marking in male mice. How aromatase-expressing neuronal populations control these diverse estrogen-dependent male behaviors is poorly understood, and the function, if any, of aromatase-expressing neurons in females is unclear. Using targeted genetic approaches, we show that aromatase-expressing neurons within the male posterodorsal medial amygdala (MeApd regulate components of aggression, but not other estrogen-dependent male-typical behaviors. Remarkably, aromatase-expressing MeApd neurons in females are specifically required for components of maternal aggression, which we show is distinct from intermale aggression in pattern and execution. Thus, aromatase-expressing MeApd neurons control distinct forms of aggression in the two sexes. Moreover, our findings indicate that complex social behaviors are separable in a modular manner at the level of genetically identified neuronal populations.

  9. Metformin Reverses Development of Pulmonary Hypertension via Aromatase Inhibition.

    Science.gov (United States)

    Dean, Afshan; Nilsen, Margaret; Loughlin, Lynn; Salt, Ian P; MacLean, Margaret R

    2016-08-01

    Females are more susceptible to pulmonary arterial hypertension than males, although the reasons remain unclear. The hypoglycemic drug, metformin, is reported to have multiple actions, including the inhibition of aromatase and stimulation of AMP-activated protein kinase. Inhibition of aromatase using anastrazole is protective in experimental pulmonary hypertension but whether metformin attenuates pulmonary hypertension through this mechanism remains unknown. We investigated whether metformin affected aromatase activity and if it could reduce the development of pulmonary hypertension in the sugen 5416/hypoxic rat model. We also investigated its influence on proliferation in human pulmonary arterial smooth muscle cells. Metformin reversed right ventricular systolic pressure, right ventricular hypertrophy, and decreased pulmonary vascular remodeling in the rat. Furthermore, metformin increased rat lung AMP-activated protein kinase signaling, decreased lung and circulating estrogen levels, levels of aromatase, the estrogen metabolizing enzyme; cytochrome P450 1B1 and its transcription factor; the aryl hydrocarbon receptor. In human pulmonary arterial smooth muscle cells, metformin decreased proliferation and decreased estrogen synthesis by decreasing aromatase activity through the PII promoter site of Cyp19a1 Thus, we report for the first time that metformin can reverse pulmonary hypertension through inhibition of aromatase and estrogen synthesis in a manner likely to be mediated by AMP-activated protein kinase. PMID:27296990

  10. A haploid genetic screen identifies the G1/S regulatory machinery as a determinant of Wee1 inhibitor sensitivity.

    Science.gov (United States)

    Heijink, Anne Margriet; Blomen, Vincent A; Bisteau, Xavier; Degener, Fabian; Matsushita, Felipe Yu; Kaldis, Philipp; Foijer, Floris; van Vugt, Marcel A T M

    2015-12-01

    The Wee1 cell cycle checkpoint kinase prevents premature mitotic entry by inhibiting cyclin-dependent kinases. Chemical inhibitors of Wee1 are currently being tested clinically as targeted anticancer drugs. Wee1 inhibition is thought to be preferentially cytotoxic in p53-defective cancer cells. However, TP53 mutant cancers do not respond consistently to Wee1 inhibitor treatment, indicating the existence of genetic determinants of Wee1 inhibitor sensitivity other than TP53 status. To optimally facilitate patient selection for Wee1 inhibition and uncover potential resistance mechanisms, identification of these currently unknown genes is necessary. The aim of this study was therefore to identify gene mutations that determine Wee1 inhibitor sensitivity. We performed a genome-wide unbiased functional genetic screen in TP53 mutant near-haploid KBM-7 cells using gene-trap insertional mutagenesis. Insertion site mapping of cells that survived long-term Wee1 inhibition revealed enrichment of G1/S regulatory genes, including SKP2, CUL1, and CDK2. Stable depletion of SKP2, CUL1, or CDK2 or chemical Cdk2 inhibition rescued the γ-H2AX induction and abrogation of G2 phase as induced by Wee1 inhibition in breast and ovarian cancer cell lines. Remarkably, live cell imaging showed that depletion of SKP2, CUL1, or CDK2 did not rescue the Wee1 inhibition-induced karyokinesis and cytokinesis defects. These data indicate that the activity of the DNA replication machinery, beyond TP53 mutation status, determines Wee1 inhibitor sensitivity, and could serve as a selection criterion for Wee1-inhibitor eligible patients. Conversely, loss of the identified S-phase genes could serve as a mechanism of acquired resistance, which goes along with development of severe genomic instability. PMID:26598692

  11. A Genome-wide CRISPR Screen Identifies CDC25A as a Determinant of Sensitivity to ATR Inhibitors.

    Science.gov (United States)

    Ruiz, Sergio; Mayor-Ruiz, Cristina; Lafarga, Vanesa; Murga, Matilde; Vega-Sendino, Maria; Ortega, Sagrario; Fernandez-Capetillo, Oscar

    2016-04-21

    One recurring theme in drug development is to exploit synthetic lethal properties as means to preferentially damage the DNA of cancer cells. We and others have previously developed inhibitors of the ATR kinase, shown to be particularly genotoxic for cells expressing certain oncogenes. In contrast, the mechanisms of resistance to ATR inhibitors remain unexplored. We report here on a genome-wide CRISPR-Cas9 screen that identified CDC25A as a major determinant of sensitivity to ATR inhibition. CDC25A-deficient cells resist high doses of ATR inhibitors, which we show is due to their failure to prematurely enter mitosis in response to the drugs. Forcing mitotic entry with WEE1 inhibitors restores the toxicity of ATR inhibitors in CDC25A-deficient cells. With ATR inhibitors now entering the clinic, our work provides a better understanding of the mechanisms by which these compounds kill cells and reveals genetic interactions that could be used for their rational use. PMID:27067599

  12. Organizing effects of sex steroids on brain aromatase activity in quail.

    Directory of Open Access Journals (Sweden)

    Charlotte A Cornil

    Full Text Available Preoptic/hypothalamic aromatase activity (AA is sexually differentiated in birds and mammals but the mechanisms controlling this sex difference remain unclear. We determined here (1 brain sites where AA is sexually differentiated and (2 whether this sex difference results from organizing effects of estrogens during ontogeny or activating effects of testosterone in adulthood. In the first experiment we measured AA in brain regions micropunched in adult male and female Japanese quail utilizing the novel strategy of basing the microdissections on the distribution of aromatase-immunoreactive cells. The largest sex difference was found in the medial bed nucleus of the stria terminalis (mBST followed by the medial preoptic nucleus (POM and the tuberal hypothalamic region. A second experiment tested the effect of embryonic treatments known to sex-reverse male copulatory behavior (i.e., estradiol benzoate [EB] or the aromatase inhibitor, Vorozole on brain AA in gonadectomized adult males and females chronically treated as adults with testosterone. Embryonic EB demasculinized male copulatory behavior, while vorozole blocked demasculinization of behavior in females as previously demonstrated in birds. Interestingly, these treatments did not affect a measure of appetitive sexual behavior. In parallel, embryonic vorozole increased, while EB decreased AA in pooled POM and mBST, but the same effect was observed in both sexes. Together, these data indicate that the early action of estrogens demasculinizes AA. However, this organizational action of estrogens on AA does not explain the behavioral sex difference in copulatory behavior since AA is similar in testosterone-treated males and females that were or were not exposed to embryonic treatments with estrogens.

  13. Sensitivity of MRI tumor biomarkers to VEGFR inhibitor therapy in an orthotopic mouse glioma model.

    Directory of Open Access Journals (Sweden)

    Christian T Farrar

    Full Text Available MRI biomarkers of tumor edema, vascular permeability, blood volume, and average vessel caliber are increasingly being employed to assess the efficacy of tumor therapies. However, the dependence of these biomarkers on a number of physiological factors can compromise their sensitivity and complicate the assessment of therapeutic efficacy. Here we examine the response of these MRI tumor biomarkers to cediranib, a potent vascular endothelial growth factor receptor (VEGFR inhibitor, in an orthotopic mouse glioma model. A significant increase in the tumor volume and relative vessel caliber index (rVCI and a slight decrease in the water apparent diffusion coefficient (ADC were observed for both control and cediranib treated animals. This contrasts with a clinical study that observed a significant decrease in tumor rVCI, ADC and volume with cediranib therapy. While the lack of a difference between control and cediranib treated animals in these biomarker responses might suggest that cediranib has no therapeutic benefit, cediranib treated mice had a significantly increased survival. The increased survival benefit of cediranib treated animals is consistent with the significant decrease observed for cediranib treated animals in the relative cerebral blood volume (rCBV, relative microvascular blood volume (rMBV, transverse relaxation time (T2, blood vessel permeability (K(trans, and extravascular-extracellular space (ν(e. The differential response of pre-clinical and clinical tumors to cediranib therapy, along with the lack of a positive response for some biomarkers, indicates the importance of evaluating the whole spectrum of different tumor biomarkers to properly assess the therapeutic response and identify and interpret the therapy-induced changes in the tumor physiology.

  14. Motion and flexibility in human cytochrome p450 aromatase.

    Directory of Open Access Journals (Sweden)

    Wenhua Jiang

    Full Text Available The crystal structures of human placental aromatase in complex with the substrate androstenedione and exemestane have revealed an androgen-specific active site and the structural basis for higher order organization. However, X-ray structures do not provide accounts of movements due to short-range fluctuations, ligand binding and protein-protein association. In this work, we conduct normal mode analysis (NMA revealing the intrinsic fluctuations of aromatase, deduce the internal modes in membrane-free and membrane-integrated monomers as well as the intermolecular modes in oligomers, and propose a quaternary organization for the endoplasmic reticulum (ER membrane integration. Dynamics of the crystallographic oligomers from NMA is found to be in agreement with the isotropic thermal factors from the X-ray analysis. Calculations of the root mean square fluctuations of the C-alpha atoms from their equilibrium positions confirm that the rigid-core structure of aromatase is intrinsic regardless of the changes in steroid binding interactions, and that aromatase self-association does not deteriorate the rigidity of the catalytic cleft. Furthermore, NMA on membrane-integrated aromatase shows that the internal modes in all likelihood contribute to breathing of the active site access channel. The collective intermolecular hinge bending and twisting modes provide the flexibility in the quaternary association necessary for membrane integration of the aromatase oligomers. Taken together, fluctuations of the active site, the access channel, and the heme-proximal cavity, and a dynamic quaternary organization could all be essential components of the functional aromatase in its role as an ER membrane-embedded steroidogenic enzyme.

  15. Hyaluronic acid-bound letrozole nanoparticles restore sensitivity to letrozole-resistant xenograft tumors in mice.

    Science.gov (United States)

    Nair, Hareesh B; Huffman, Steven; Veerapaneni, Poornachand; Kirma, Nameer B; Binkley, Peter; Perla, Rao P; Evans, Dean B; Tekmal, Rajeshwar R

    2011-05-01

    Letrozole is a potent aromatase inhibitor and superior to other defined selective estrogen receptor modulators such as tamoxifen in treating hormone-responsive postmenopausal breast cancer patients. Patients who receive this drug may become insensitive to the effects of estrogen deprivation induced by letrozole. Letrozole has known side effects on bone metabolism due to systemic ablation of estrogen production. The purpose of this study was to examine the therapeutic efficacy of hyaluronic acid-bound letrozole nanoparticles (HA-Letr-NPs) in restoring sensitivity to letrozole-resistant (LTLT-Ca) cells. To target letrozole to LTLT-Ca cells, hyaluronic acid-bound letrozole nanoparticles were prepared by nanoprecipitation using biodegradable PLGA-PEG co-polymer. Binding specificity of HA to CD44 on the cell surface was analyzed in vitro using FITC-CD44 Ab and CD44 siRNA by flow cytometry. Effects on in vitro cytotoxicity and aromatase enzymatic activity of HA-Letr-NPs were performed in MCF-7 breast cancer cells, MCF-7 cells over-expressing aromatase (MCF-7/Aro), and LTLT-Ca cells resistant to letrozole. Preclinical efficacy of HA-Letr-NPs was examined in mice using LTLT-Ca xenograft tumors. HA-Letr-NPs were restricted to a maximum size of 100 nm. The in vitro drug release assay showed that the highest released concentration of letrozole occurred after 23 hours at 37 degrees C in phosphate-buffered saline. HA-Letr-NPs on MCF-7/Aro and LTLT-Ca cells showed an IC50 of 2 microM and 5 microM, respectively. HA-Letr-NPs were more efficacious in inhibiting tumor growth, reducing in vitro cellular and in vivo tumor aromatase enzyme activity more than the corresponding Letr-NPs or letrozole. HA-Letr-NPs restored and maintained a prolonged sensitivity and targeted delivery of letrozole in letrozole-resistant tumors in vivo. PMID:21780370

  16. Chemo-genomic interrogation of CEBPA mutated AML reveals recurrent CSF3R mutations and subgroup sensitivity to JAK inhibitors.

    Science.gov (United States)

    Lavallée, Vincent-Philippe; Krosl, Jana; Lemieux, Sébastien; Boucher, Geneviève; Gendron, Patrick; Pabst, Caroline; Boivin, Isabel; Marinier, Anne; Guidos, Cynthia J; Meloche, Sylvain; Hébert, Josée; Sauvageau, Guy

    2016-06-16

    In this study, we analyzed RNA-sequencing data of 14 samples characterized by biallelic CEBPA (CEBPA(bi)) mutations included in the Leucegene collection of 415 primary acute myeloid leukemia (AML) specimens, and describe for the first time high frequency recurrent mutations in the granulocyte colony-stimulating factor receptor gene CSF3R, which signals through JAK-STAT proteins. Chemical interrogation of these primary human specimens revealed a uniform and specific sensitivity to all JAK inhibitors tested irrespective of their CSF3R mutation status, indicating a general sensitization of JAK-STAT signaling in this leukemia subset. Altogether, these results identified the co-occurrence of mutations in CSF3R and CEBPA in a well-defined AML subset, which uniformly responds to JAK inhibitors and paves the way to personalized clinical trials for this disease. PMID:27034432

  17. Variation in HIV-1 R5 macrophage-tropism correlates with sensitivity to reagents that block envelope: CD4 interactions but not with sensitivity to other entry inhibitors

    Directory of Open Access Journals (Sweden)

    Simmonds Peter

    2008-01-01

    Full Text Available Abstract Background HIV-1 R5 viruses cause most of the AIDS cases worldwide and are preferentially transmitted compared to CXCR4-using viruses. Furthermore, R5 viruses vary extensively in capacity to infect macrophages and highly macrophage-tropic variants are frequently identified in the brains of patients with dementia. Here, we investigated the sensitivity of R5 envelopes to a range of inhibitors and antibodies that block HIV entry. We studied a large panel of R5 envelopes, derived by PCR amplification without culture from brain, lymph node, blood and semen. These R5 envelopes conferred a wide range of macrophage tropism and included highly macrophage-tropic variants from brain and non-macrophage-tropic variants from lymph node. Results R5 macrophage-tropism correlated with sensitivity to inhibition by reagents that inhibited gp120:CD4 interactions. Thus, increasing macrophage-tropism was associated with increased sensitivity to soluble CD4 and to IgG-CD4 (PRO 542, but with increased resistance to the anti-CD4 monoclonal antibody (mab, Q4120. These observations were highly significant and are consistent with an increased affinity of envelope for CD4 for macrophage-tropic envelopes. No overall correlations were noted between R5 macrophage-tropism and sensitivity to CCR5 antagonists or to gp41 specific reagents. Intriguingly, there was a relationship between increasing macrophage-tropism and increased sensitivity to the CD4 binding site mab, b12, but decreased sensitivity to 2G12, a mab that binds a glycan complex on gp120. Conclusion Variation in R5 macrophage-tropism is caused by envelope variation that predominantly influences sensitivity to reagents that block gp120:CD4 interactions. Such variation has important implications for therapy using viral entry inhibitors and for the design of envelope antigens for vaccines.

  18. Differential sensitivity of melanoma cell lines with BRAFV600E mutation to the specific Raf inhibitor PLX4032

    Directory of Open Access Journals (Sweden)

    Kehoe Sarah M

    2010-04-01

    Full Text Available Abstract Blocking oncogenic signaling induced by the BRAFV600E mutation is a promising approach for melanoma treatment. We tested the anti-tumor effects of a specific inhibitor of Raf protein kinases, PLX4032/RG7204, in melanoma cell lines. PLX4032 decreased signaling through the MAPK pathway only in cell lines with the BRAFV600E mutation. Seven out of 10 BRAFV600E mutant cell lines displayed sensitivity based on cell viability assays and three were resistant at concentrations up to 10 μM. Among the sensitive cell lines, four were highly sensitive with IC50 values below 1 μM, and three were moderately sensitive with IC50 values between 1 and 10 μM. There was evidence of MAPK pathway inhibition and cell cycle arrest in both sensitive and resistant cell lines. Genomic analysis by sequencing, genotyping of close to 400 oncogeninc mutations by mass spectrometry, and SNP arrays demonstrated no major differences in BRAF locus amplification or in other oncogenic events between sensitive and resistant cell lines. However, metabolic tracer uptake studies demonstrated that sensitive cell lines had a more profound inhibition of FDG uptake upon exposure to PLX4032 than resistant cell lines. In conclusion, BRAFV600E mutant melanoma cell lines displayed a range of sensitivities to PLX4032 and metabolic imaging using PET probes can be used to assess sensitivity.

  19. Differential sensitivity of melanoma cell lines with BRAFV600E mutation to the specific raf inhibitor PLX4032

    DEFF Research Database (Denmark)

    Søndergaard, Jonas Nørskov; Nazarian, R.; Wang, Q.;

    2010-01-01

    Blocking oncogenic signaling induced by the BRAFV600E mutation is a promising approach for melanoma treatment. We tested the anti-tumor effects of a specific inhibitor of Raf protein kinases, PLX4032/RG7204, in melanoma cell lines. PLX4032 decreased signaling through the MAPK pathway only in cell...... differences in BRAF locus amplification or in other oncogenic events between sensitive and resistant cell lines. However, metabolic tracer uptake studies demonstrated that sensitive cell lines had a more profound inhibition of FDG uptake upon exposure to PLX4032 than resistant cell lines. In conclusion, BRAFV...

  20. Selective trihydroxyazepane NagZ inhibitors increase sensitivity of Pseudomonas aeruginosa to β-lactams.

    Science.gov (United States)

    Mondon, Martine; Hur, Soo; Vadlamani, Grishma; Rodrigues, Prerana; Tsybina, Polina; Oliver, Antonio; Mark, Brian L; Vocadlo, David J; Blériot, Yves

    2013-12-01

    AmpC β-lactamase confers resistance to β-lactam antibiotics in many Gram negative bacteria. Inducible expression of AmpC requires an N-acetylglucosaminidase termed NagZ. Here we describe the synthesis and characterization of hydroxyazepane inhibitors of NagZ. We find that these inhibitors enhance the susceptibility of clinically relevant Pseudomonas aeruginosa to β-lactams. PMID:24136176

  1. Aromatase immunolocalization in human ductuli efferentes and proximal ductus epididymis.

    Science.gov (United States)

    Carpino, A; Romeo, F; Rago, V

    2004-03-01

    Abstract Cytochrome P450 aromatase is a terminal enzyme that catalyses the conversion of androgens into oestrogens. This study investigated the immunohistochemical localization of aromatase in human efferent ductules and proximal ductus epididymis using a mouse anti-human monoclonal P450arom IgG as primary antibody and a goat anti-mouse biotinylated IgG as secondary antibody. A strong immunoreaction was observed in the epithelial cell cytoplasm of both ductuli efferentes and proximal ductus epididymis, whereas the smooth muscle cells were immunonegative in the two regions. The results show, for the first time in humans, that epithelial cells of ductuli efferentes and proximal caput epididymis express aromatase, suggesting that locally produced oestrogens may have a role in epididymal function. PMID:15032911

  2. Mps1 Mediated Phosphorylation of Hsp90 Confers Renal Cell Carcinoma Sensitivity and Selectivity to Hsp90 Inhibitors

    Directory of Open Access Journals (Sweden)

    Mark R. Woodford

    2016-02-01

    Full Text Available The molecular chaperone Hsp90 protects deregulated signaling proteins that are vital for tumor growth and survival. Tumors generally display sensitivity and selectivity toward Hsp90 inhibitors; however, the molecular mechanism underlying this phenotype remains undefined. We report that the mitotic checkpoint kinase Mps1 phosphorylates a conserved threonine residue in the amino-domain of Hsp90. This, in turn, regulates chaperone function by reducing Hsp90 ATPase activity while fostering Hsp90 association with kinase clients, including Mps1. Phosphorylation of Hsp90 is also essential for the mitotic checkpoint because it confers Mps1 stability and activity. We identified Cdc14 as the phosphatase that dephosphorylates Hsp90 and disrupts its interaction with Mps1. This causes Mps1 degradation, thus providing a mechanism for its inactivation. Finally, Hsp90 phosphorylation sensitizes cells to its inhibitors, and elevated Mps1 levels confer renal cell carcinoma selectivity to Hsp90 drugs. Mps1 expression level can potentially serve as a predictive indicator of tumor response to Hsp90 inhibitors.

  3. Inhibition of human aromatase complex (CYP19) by antiepileptic drugs

    DEFF Research Database (Denmark)

    Jacobsen, Naja Wessel; Halling-Sørensen, Bent; Birkved, Franziska Maria A Kramer

    2008-01-01

    Antiepileptic drugs and epilepsy are often associated with sexual disorder in women such as hyperandrogenism, menstrual disorders and ovarian cysts. In children, until puberty, a hormone imbalance may influence many aspects of development, e.g. growth and sexual maturation. The aromatase complex ...... with valproate and phenobarbital. When adding carbamazepine to a range of valproate concentrations no additional inhibition was seen. The data for some of the AEDs show that side effects on steroid synthesis in humans due to inhibition of aromatase should be considered....

  4. Contribution of intrinsic reactivity of the HIV-1 envelope glycoproteins to CD4-independent infection and global inhibitor sensitivity.

    Directory of Open Access Journals (Sweden)

    Hillel Haim

    2011-06-01

    inhibitor/antibody binding to the envelope glycoprotein trimer and by envelope glycoprotein reactivity to the inhibitor/antibody binding event. Quantitative differences in intrinsic reactivity contribute to HIV-1 strain variability in global susceptibility to neutralization and explain the long-observed relationship between increased inhibitor sensitivity and decreased entry requirements for target cell CD4.

  5. Recombinant HCV variants with NS5A from genotypes 1-7 have different sensitivities to an NS5A inhibitor but not interferon-a

    DEFF Research Database (Denmark)

    Scheel, Troels K H; Gottwein, Judith M; Mikkelsen, Lotte S;

    2011-01-01

    Heterogeneity in the hepatitis C virus (HCV) protein NS5A influences its sensitivity to interferon-based therapy. Furthermore, NS5A is an important target for development of HCV-specific inhibitors. We aimed to develop recombinant infectious cell culture systems that express NS5A from isolates...... of the 7 major HCV genotypes, and determining their sensitivity to a specific NS5A inhibitor and to interferon-a....

  6. Effect of Candesartan Cilexetil as a Sensitive and Effective Inhibitor of SHP-1 on Insulin Signaling Pathway

    Institute of Scientific and Technical Information of China (English)

    ZHANG Lei; ZHANG Shi-tao; ZHANG Xiao-ping; SUN Jing; WANG Yong-sen; LIU Yue-long; XUE Miao-miao

    2013-01-01

    The protein tyrosine phosphatases(PTPs) comprise a family of enzymes that specifically dephosphorylate tyrosyl residues.Among them,SHP-1 has been regarded as one of the best validated intracellular tyrosine phosphatases.Downregulation of SHP-1 has shown remarkable efficacy in improving insulin sensitivity in vivo in insulin signaling pathway.In this study,we found the role of Candesartan cilexetil targeting at SHP-1.The results indicate that Candesartan cilexetil was a competitive inhibitor to SHP-1(IC50=85.6 μmol/L and Ki=24 μmol/L).We also found that Candesartan cilexetil was more sensitive towards SHP-1 compared with other PTPs.Through the consequence of Western blotting,it showed that Candesartan cilexetil can strengthen the level of tyrosine phosphorylation of several key cellular proteins[such as insulin receptor(IR),insulin receptor substrate(IRS) and ERK] in insulin signaling pathway in HepG2 cells and improve the insulin sensitivity through inhibiting the protein phosphorylation of SHP-1.These findings showed that Candesartan cilexetil might be an important inhibitor of SHP-1 and had a great application potential in the treatment of diabetes through inhibiting the level of SHP-1 in insulin signaling pathway.

  7. A redox-sensitive loop regulates plasminogen activator inhibitor type 2 (PAI-2) polymerization

    OpenAIRE

    Wilczynska, Malgorzata; Lobov, Sergei; Ohlsson, Per-Ingvar; Ny, Tor

    2003-01-01

    Plasminogen activator inhibitor type 2 (PAI-2) is the only wild-type serpin that polymerizes spontaneously under physiological conditions. We show that PAI-2 loses its ability to polymerize following reduction of thiol groups, suggesting that an intramolecular disulfide bond is essential for the polymerization. A novel disulfide bond was identified between C79 (in the CD-loop) and C161 (at the bottom of helix F). Substitution mutants in which this disulfide bond was broken did not polymerize....

  8. P-glycoprotein inhibitors of natural origin as potential tumor chemo-sensitizers: A re

    Directory of Open Access Journals (Sweden)

    Hossam M. Abdallah

    2015-01-01

    Full Text Available Resistance of solid tumors to treatment is significantly attributed to pharmacokinetic reasons at both cellular and multi-cellular levels. Anticancer agent must be bio-available at the site of action in a cytotoxic concentration to exert its proposed activity. P-glycoprotein (P-gp is a member of the ATP-dependent membrane transport proteins; it is known to pump substrates out of cells in ATP-dependent mechanism. The over-expression of P-gp in tumor cells reduces the intracellular drug concentrations, which decreases the cytotoxicity of a broad spectrum of antitumor drugs. Accordingly, P-gp inhibitors/blockers are potential enhancer for the cellular bioavailability of several clinically important anticancer drugs such as, anthracyclines, taxanes, vinca alkaloids, and podophyllotoxins. Besides several chemically synthesized P-gp inhibitors/blockers, some naturally occurring compounds and plant extracts were reported for their modulation of multidrug resistance; however, this review will focus only on major classes of naturally occurring inhibitors viz., flavonoids, coumarins, terpenoids, alkaloids and saponins.

  9. PARP1 expression, activity and ex vivo sensitivity to the PARP inhibitor, talazoparib (BMN 673), in chronic lymphocytic leukaemia.

    Science.gov (United States)

    Herriott, Ashleigh; Tudhope, Susan J; Junge, Gesa; Rodrigues, Natalie; Patterson, Miranda J; Woodhouse, Laura; Lunec, John; Hunter, Jill E; Mulligan, Evan A; Cole, Michael; Allinson, Lisa M; Wallis, Jonathan P; Marshall, Scott; Wang, Evelyn; Curtin, Nicola J; Willmore, Elaine

    2015-12-22

    In chronic lymphocytic leukemia (CLL), mutation and loss of p53 and ATM abrogate DNA damage signalling and predict poorer response and shorter survival. We hypothesised that poly (ADP-ribose) polymerase (PARP) activity, which is crucial for repair of DNA breaks induced by oxidative stress or chemotherapy, may be an additional predictive biomarker and a target for therapy with PARP inhibitors.We measured PARP activity in 109 patient-derived CLL samples, which varied widely (192 - 190052 pmol PAR/10⁶ cells) compared to that seen in healthy volunteer lymphocytes (2451 - 7519 pmol PAR/10⁶ cells). PARP activity was associated with PARP1 protein expression and endogenous PAR levels. PARP activity was not associated with p53 or ATM loss, Binet stage, IGHV mutational status or survival, but correlated with Bcl-2 and Rel A (an NF-kB subunit). Levels of 8-hydroxy-2'-deoxyguanosine in DNA (a marker of oxidative damage) were not associated with PAR levels or PARP activity. The potent PARP inhibitor, talazoparib (BMN 673), inhibited CD40L-stimulated proliferation of CLL cells at nM concentrations, independently of Binet stage or p53/ATM function.PARP activity is highly variable in CLL and correlates with stress-induced proteins. Proliferating CLL cells (including those with p53 or ATM loss) are highly sensitive to the PARP inhibitor talazoparib. PMID:26539646

  10. The CYP3A4 inhibitor intraconazole does not affect the pharmacokinetics of a new calcium-sensitizing drug levosimendan.

    Science.gov (United States)

    Antila, S; Honkanen, T; Lehtonen, L; Neuvonen, P J

    1998-08-01

    Itraconazole is a potent inhibitor of CYP3A4 isoenzyme and it can cause clinically significant interactions with some other drugs. Levosimendan is a new calcium-sensitizing drug intended for congestive heart failure. We aimed to study possible interactions of itraconazole with levosimendan in healthy volunteers. Twelve healthy male volunteers were included into a randomized, double-blind, two-phase crossover study. A wash-out period of 4 weeks was held between the phases. The subjects were given orally itraconazole 200 mg or placebo daily for 5 days. On the fifth day, they received a single oral dose of 2 mg of levosimendan. Levosimendan plasma concentrations were determined up to 12 hours and ECG, heart rate, and blood pressure followed-up to 8 hours after intake of levosimendan. Itraconazole had no significant effects on the pharmacokinetic parameters of levosimendan. Neither were there any differences in heart rate, PQ-, QTc- or QRS intervals between the placebo and itraconazole phases. The systolic blood pressure was decreased slightly more (p < 0.05) during the itraconazole phase than during the placebo phase. In conclusion, because the potent CYP3A4 inhibitor itraconazole had no significant pharmacokinetic interaction with levosimendan, interactions with CYP3A4 inhibitor, and oral levosimendan are unlikely.

  11. Aromatase, estrogen receptors and brain development in fish and amphibians.

    Science.gov (United States)

    Coumailleau, Pascal; Pellegrini, Elisabeth; Adrio, Fátima; Diotel, Nicolas; Cano-Nicolau, Joel; Nasri, Ahmed; Vaillant, Colette; Kah, Olivier

    2015-02-01

    Estrogens affect brain development of vertebrates, not only by impacting activity and morphology of existing circuits, but also by modulating embryonic and adult neurogenesis. The issue is complex as estrogens can not only originate from peripheral tissues, but also be locally produced within the brain itself due to local aromatization of androgens. In this respect, teleost fishes are quite unique because aromatase is expressed exclusively in radial glial cells, which represent pluripotent cells in the brain of all vertebrates. Expression of aromatase in the brain of fish is also strongly stimulated by estrogens and some androgens. This creates a very intriguing positive auto-regulatory loop leading to dramatic aromatase expression in sexually mature fish with elevated levels of circulating steroids. Looking at the effects of estrogens or anti-estrogens in the brain of adult zebrafish showed that estrogens inhibit rather than stimulate cell proliferation and newborn cell migration. The functional meaning of these observations is still unclear, but these data suggest that the brain of fish is experiencing constant remodeling under the influence of circulating steroids and brain-derived neurosteroids, possibly permitting a diversification of sexual strategies, notably hermaphroditism. Recent data in frogs indicate that aromatase expression is limited to neurons and do not concern radial glial cells. Thus, until now, there is no other example of vertebrates in which radial progenitors express aromatase. This raises the question of when and why these new features were gained and what are their adaptive benefits. This article is part of a Special Issue entitled: Nuclear receptors in animal development.

  12. Selenium-containing thioredoxin reductase inhibitor ethaselen sensitizes non-small cell lung cancer to radiotherapy.

    Science.gov (United States)

    Wang, Lei; Fu, Jia-Ning; Wang, Jing-Yu; Jin, Cun-Jing; Ren, Xiao-Yuan; Tan, Qiang; Li, Jing; Yin, Han-Wei; Xiong, Kun; Wang, Tian-Yu; Liu, Xin-Min; Zeng, Hui-Hui

    2011-09-01

    It has been proposed that thioredoxin reductase (TR) is a mediator that allows non-small cell lung cancer (NSCLC) to develop resistance to irradiation; however, little is known regarding the detailed mechanisms of action. Thus, ethaselen {1, 2-[bis (1,2-benzisoselenazolone-3 (2H)-ketone)] ethane, BBSKE}, a novel organoselenium TR inhibitor, is currently being investigated in a phase I clinical trial in China. However, its radiosensitizing effect remains unexplored. In this study, we found that the activity of TR increased dramatically in both A549 and H1299 cells after radiation, and moreover, could be inhibited by pretreatment with BBSKE (5 μmol/l). As a TR inhibitor, BBSKE enhanced the efficacy of radiation therapy both in vivo and in vitro without observable toxicity. BBSKE was found to suppress irradiation-induced NF-κB activation dramatically when using A549 cells stably transfected with NF-κB luciferase reporter. These results show the critical role of TR in the radioresistance of NSCLC and suggest that BBSKE is a potentially promising agent for the treatment of patients with NSCLC clinically. PMID:21562407

  13. A Highly Sensitive Telomerase Activity Assay that Eliminates False-Negative Results Caused by PCR Inhibitors

    Directory of Open Access Journals (Sweden)

    Hidenobu Yaku

    2013-09-01

    Full Text Available An assay for telomerase activity based on asymmetric polymerase chain reaction (A-PCR on magnetic beads (MBs and subsequent application of cycling probe technology (CPT is described. In this assay, the telomerase reaction products are immobilized on MBs, which are then washed to remove PCR inhibitors that are commonly found in clinical samples. The guanine-rich sequences (5'-(TTAGGGn-3' of the telomerase reaction products are then preferentially amplified by A-PCR, and the amplified products are subsequently detected via CPT, where a probe RNA with a fluorophore at the 5' end and a quencher at the 3' end is hydrolyzed by RNase H in the presence of the target DNA. The catalyst-mediated cleavage of the probe RNA enhances fluorescence from the 5' end of the probe. The assay allowed us to successfully detect HeLa cells selectively over normal human dermal fibroblast (NHDF cells. Importantly, this selectivity produced identical results with regard to detection of HeLa cells in the absence and presence of excess NHDF cells; therefore, this assay can be used for practical clinical applications. The lower limit of detection for HeLa cells was 50 cells, which is lower than that achieved with a conventional telomeric repeat amplification protocol assay. Our assay also eliminated false-negative results caused by PCR inhibitors. Furthermore, we show that this assay is appropriate for screening among G-quadruplex ligands to find those that inhibit telomerase activity.

  14. BIIB021, a novel Hsp90 inhibitor, sensitizes esophageal squamous cell carcinoma to radiation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xin-Tong; Bao, Ci-Hang; Jia, Yi-Bin; Wang, Nana [Department of Radiation Oncology, Qilu Hospital of Shandong University, Jinan 250012 (China); Ma, Wei [Department of Radiation Oncology, Cancer Hospital, General Hospital of Ningxia Medical University, Yinchuan 750000 (China); Liu, Fang [Medical Imaging, Shandong Medical College, Jinan 250002 (China); Wang, Cong; Wang, Jian-Bo; Song, Qing-Xu [Department of Radiation Oncology, Qilu Hospital of Shandong University, Jinan 250012 (China); Cheng, Yu-Feng, E-mail: qlcyf1965@126.com [Department of Radiation Oncology, Qilu Hospital of Shandong University, Jinan 250012 (China)

    2014-10-03

    Highlights: • BIIB021 downregulated radioresistant proteins in ESCC cell lines. • BIIB021 increased radiation-induced apoptotic cells. • BIIB021 enhanced G{sub 2} arrest in ESCC cell lines. • BIIB021 is a good candidate for radiosensitizer in radiotherapy of ESCC patients. - Abstract: BIIB021 is a novel, orally available inhibitor of heat shock protein 90 (Hsp90) that is currently in phase I/II clinical trials. BIIB021 induces the apoptosis of various types of tumor cells in vitro and in vivo. The aim of this study is to investigate the effect of BIIB021 on the radiosensitivity of esophageal squamous cell carcinoma (ESCC). The results indicated that BIIB021 exhibited strong antitumor activity in ESCC cell lines, either as a single agent or in combination with radiation. BIIB021 significantly downregulated radioresistant proteins including EGFR, Akt, Raf-1 of ESCC cell lines, increased apoptotic cells and enhanced G{sub 2} arrest that is more radiosensitive cell cycle phase. These results suggest that this synthetic Hsp90 inhibitor simultaneously affects multiple pathways involved in tumor development and progression in the ESCC setting and may represent a better strategy for the treatment of ESCC patients, either as a monotherapy or a radiosensitizer.

  15. The impact of calcineurin inhibitors on insulin sensitivity and insulin secretion

    DEFF Research Database (Denmark)

    Øzbay, Aygen; Møller, N; Juhl, C;

    2012-01-01

    pulsatile insulin secretion were not significantly affected by the drugs. CONCLUSION: In conclusion, 8-10 days of treatment with cyclosporine and tacrolimus impairs insulin sensitivity to a similar degree in haemodialysis patients, while acute insulin responses and pulsatile insulin secretion remain...

  16. Anti-aromatase effect of resveratrol and melatonin on hormonal positive breast cancer cells co-cultured with breast adipose fibroblasts.

    Science.gov (United States)

    Chottanapund, Suthat; Van Duursen, M B M; Navasumrit, Panida; Hunsonti, Potchanee; Timtavorn, Supatchaya; Ruchirawat, Mathuros; Van den Berg, Martin

    2014-10-01

    Targeting the estrogen pathway has been proven effective in the treatment for estrogen receptor positive breast cancer. There are currently two common groups of anti-estrogenic compounds used in the clinic; Selective Estrogen Receptor Modulators (SERMs, e.g. tamoxifen) and Selective Estrogen Enzyme Modulators (SEEMs e.g. letrozole). Among various naturally occurring, biologically active compounds, resveratrol and melatonin have been suggested to act as aromatase inhibitors, which make them potential candidates in hormonal treatment of breast cancer. Here we used a co-culture model in which we previously demonstrated that primary human breast adipose fibroblasts (BAFs) can convert testosterone to estradiol, which subsequently results in estrogen receptor-mediated breast cancer T47D cell proliferation. In the presence of testosterone in this model, we examined the effect of letrozole, resveratrol and melatonin on cell proliferation, estradiol (E2) production and gene expression of CYP19A1, pS2 and Ki-67. Both melatonin and resveratrol were found to be aromatase inhibitors in this co-culture system, albeit at different concentrations. Our co-culture model did not provide any indications that melatonin is also a selective estrogen receptor modulator. In the T47D-BAF co-culture, a melatonin concentration of 20 nM and resveratrol concentration of 20 μM have an aromatase inhibitory effect as potent as 20 nM letrozole, which is a clinically used anti-aromatase drug in breast cancer treatment. The SEEM mechanism of action of especially melatonin clearly offers potential advantages for breast cancer treatment. PMID:24929094

  17. Differential expression of genes for aromatase and estrogen receptor during the gonadal development in chicken embryos.

    Science.gov (United States)

    Nakabayashi, O; Kikuchi, H; Kikuchi, T; Mizuno, S

    1998-04-01

    In birds, differentiation of embryonic gonads is not as strictly determined by the genetic sex as it is in mammals, and can be influenced by early manipulation with a sex steroid hormone. Thus administration of an aromatase inhibitor induces testis development in the genetic female, and administration of estrogen induces a left ovotestis in the genetic male embryo. Another feature of avian gonadogenesis is that only the left ovary develops in most species. Molecular mechanisms underlying these features at the level of gene expression have not been elucidated. In this paper, we present evidence that a gene for aromatase cytochrome P-450, an enzyme required for the last step in the synthesis of estradiol-17beta, is expressed in medullae of the left and right gonads of a female chicken embryo, but not in those of a male chicken embryo, and that an estrogen receptor gene is expressed only in epithelium (and cortex later, in the female) of the left, not the right, gonad of both sexes, but the expression in the male left gonad is temporary and restricted to an early stage of development. Differential expression of these two genes serves well to explain the above features of gonadal development in birds. Furthermore, in ovo administration of estradiol-17beta from the 5th to the 14th day of incubation does not cause expression of the estrogen receptor gene in the right gonad of chicken embryos of either sex, suggesting that the absence of expression of the estrogen receptor gene in the right gonad is not the result of down-regulation, but may be regarded as an important cause of the unilateral ovarian development. PMID:9584834

  18. Metabolic alterations and drug sensitivity of tyrosine kinase inhibitor resistant leukemia cells with a FLT3/ITD mutation.

    Science.gov (United States)

    Huang, Amin; Ju, Huai-Qiang; Liu, Kaiyan; Zhan, Guilian; Liu, Daolu; Wen, Shijun; Garcia-Manero, Guillermo; Huang, Peng; Hu, Yumin

    2016-07-28

    Internal tandem duplication (ITD) of the juxtamembrane region of FMS-like tyrosine kinase-3 (FLT3) receptor is a common type of mutation in adult acute myeloid leukemia (AML), and patient response to FLT3 inhibitors appears to be transient due to the emergence of drug resistance. We established two sorafenib-resistant cell lines carrying FLT3/ITD mutations, including the murine BaF3/ITD-R and human MV4-11-R cell lines. Gene expression profile analysis of the resistant and parental cells suggests that the highest ranked molecular and cellular functions of the differentially expressed genes are related to mitochondrial dysfunction. Both murine and human resistant cell lines display a longer doubling time, along with a significant inhibition of mitochondrial respiratory chain activity and substantial upregulation of glycolysis. The sorafenib-resistant cells exhibit increased expression of a majority of glycolytic enzymes, including hexokinase 2, which is also highly expressed in the mitochondrial fraction and is associated with resistance to apoptotic cell death. The sorafenib-resistant cells are collaterally sensitive to a number of glycolytic inhibitors including 2-deoxyglucose and 3-bromopyruvate propylester. Our study reveals a metabolic signature of sorafenib-resistant cells and suggests that glycolytic inhibition may override such resistance and warrant further clinical investigation. PMID:27132990

  19. Knockdown of TAZ modifies triple-negative breast cancer cell sensitivity to EGFR inhibitors by regulating YAP expression.

    Science.gov (United States)

    Guo, Liwen; Zheng, Jiaping; Zhang, Jing; Wang, Haohao; Shao, Guoliang; Teng, Lisong

    2016-08-01

    Triple-negative breast cancer (TNBC) constitutes ~10-15% of breast cancer patients and represents an aggressive subtype with poor overall prognosis. TNBC is an important clinical challenge because it does not respond well to endocrine therapy and have a higher rate of early recurrence and distant metastasis following chemotherapy. Although it has been reported that the epidermal growth factor receptor (EGFR) was overexpressed in ~80% of TNBC, anti-EGFR therapy showed limited clinical benefit according to phase II studies. In this study, we first observed that knockdown of the transcriptional coactivator with PDZ-binding domain (TAZ) gene can regulate the sensitivity of TNBC cell lines to EGFR inhibitors (EGFRI) in a cell context-depended manner. Furthermore, in certain breast cancer cell lines the YES-associated protein, paralog of TAZ (YAP) expression can be upregulated by TAZ inhibition which leads to EGFRI resistance. These results suggest a specific inhibitor to TAZ/YAP combined with anti-EGFR therapy may prove effective and provide a reason why targeting EGFR showed limited clinical benefit in TNBC treatment. PMID:27373987

  20. Role of oxidative stress and intracellular glutathione in the sensitivity to apoptosis induced by proteasome inhibitor in thyroid cancer cells

    Directory of Open Access Journals (Sweden)

    Guan Yifu

    2009-02-01

    Full Text Available Abstract Background The proteasome inhibitor bortezomib has shown impressive clinical activity alone and in combination with conventional and other novel agents for the treatment of multiple myeloma (MM and some solid cancers. Although bortezomib is known to be a selective proteasome inhibitor, the downstream mechanisms of cytotoxicity and drug resistance are poorly understood. Methods Proteasome activity, intracellular glutathione (GSH and ROS levels, as well as activities of GSH synthesis enzymes were measured using spectrophotometric methods. Cell death was analyzed using flow cytometry and caspase activity assay. The expression level of GSH synthesis enzymes were measured using real-time RT-PCR. Results At concentrations that effectively inhibited proteasome activity, bortezomib induced apoptosis in FRO cells, but not in ARO cells. Bortezomib elevated the amount of glutathione (GSH and the treatment with bortezomib increased the level of mRNA for GCL, a rate-limiting enzyme in glutathione synthesis. Furthermore, depletion of GSH increases apoptosis induced by bortezomib, in contrast, repletion of GSH decreases bortezomib-mediated cell death. Conclusion GSH protects cells from proteasome inhibition-induced oxidative stress and glutathione-dependent redox system might play an important role in the sensitivity to proteasome inhibition-induced apoptosis.

  1. Structure-guided Inhibitor Design Expands the Scope of Analog-Sensitive Kinase Technology

    OpenAIRE

    Zhang, Chao; Lopez, Michael S.; Dar, Arvin C.; LaDow, Eva; Finkbeiner, Steven; Yun, Cai-Hong; Eck, Michael J; Shokat, Kevan M.

    2013-01-01

    Engineered analog-sensitive (AS) protein kinases have emerged as powerful tools for dissecting phospho-signaling pathways, for elucidating the cellular function of individual kinases, and for deciphering unanticipated effects of clinical therapeutics. A crucial and necessary feature of this technology is a bioorthogonal small molecule that is innocuous towards native cellular systems but can potently inhibit the engineered kinase. In order to generalize this method we sought a molecule capabl...

  2. Hepatocyte growth factor reduces sensitivity to the epidermal growth factor receptor-tyrosine kinase inhibitor, gefitinib, in lung adenocarcinoma cells harboring wild-type EGFR

    Science.gov (United States)

    Yang, Hua; Wang, Rong; Peng, Shunli; Chen, Longhua; Li, Qi; Wang, Wei

    2016-01-01

    Epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) therapy is an option for lung cancers harboring wild-type EGFR when chemotherapeutic reagents have failed. In this study, we found that the EGFR-TKI, gefitinib, modestly suppressed proliferation of the lung cancer cell lines, A549 and H358, which both harbor wild-type EGFR. Treatment with hepatocyte growth factor (HGF) reduced the sensitivity to gefitinib, whereas sensitivity was restored by treatment with an HGF antibody, a MET inhibitor, or depletion of MET but not ErbB3 gene. Moreover, both PI3K/mTOR inhibitors and MEK inhibitors suppressed proliferation of A549 cells, whereas only PI3K/mTOR inhibitors effectively suppressed cell viability of EGFR mutant PC-9 cells. Our findings suggest that HGF reduced the gefitinib sensitivity through MET and downstream PI3K and MAPK pathways. Combined use of EGFR-TKI and MET inhibitors or inhibition of downstream signaling molecules might be a better second or third line choice for a group of patients with advanced lung cancer harboring wild-type EGFR. PMID:26919104

  3. KDR activating mutations in human angiosarcomas are sensitive to specific kinase inhibitors.

    Science.gov (United States)

    Antonescu, Cristina R; Yoshida, Akihiko; Guo, Tianhuo; Chang, Ning-En; Zhang, Lei; Agaram, Narasimhan P; Qin, Li-Xuan; Brennan, Murray F; Singer, Samuel; Maki, Robert G

    2009-09-15

    Angiosarcomas (AS) represent a heterogeneous group of malignant vascular tumors occurring not only in different anatomic locations but also in distinct clinical settings, such as radiation or associated chronic lymphedema. Although representing only 1% to 2% of soft tissue sarcomas, vascular sarcomas provide unique insight into the general process of tumor angiogenesis. However, no molecular candidates have been identified to guide a specific therapeutic intervention. By expression profiling, AS show distinct up-regulation of vascular-specific receptor tyrosine kinases, including TIE1, KDR, SNRK, TEK, and FLT1. Full sequencing of these five candidate genes identified 10% of patients harboring KDR mutations. A KDR-positive genotype was associated with strong KDR protein expression and was restricted to the breast anatomic site with or without prior exposure to radiation. Transient transfection of KDR mutants into COS-7 cells showed ligand-independent activation of the kinase, which was inhibited by specific KDR inhibitors. These data provide a basis for the activity of vascular endothelial growth factor receptor-directed therapy in the treatment of primary and radiation-induced AS. PMID:19723655

  4. Effect of protein kinase C inhibitor (PKCI) on radiation sensitivity and c-fos transcription activity

    International Nuclear Information System (INIS)

    The human genetic disorder ataxia-telangiectasia (AT) is a multisystem disease characterized by extreme radiosensitivity. The recent identification of the gene mutated in AT, ATM, and the demonstration that it encodes a homologous domain of phosphatidylinositol 3-kinase (PI3-K), the catalytic subunit of an enzyme involved in transmitting signals from the cell surface to the nucleus, provide support for a role of this gene in signal transduction. Although ionizing radiation was known to induce c-fos transcription, nothing is known about how ATM or PKCI mediated signal transduction pathway modulates the c-fos gene transcription and gene expression. Here we have studied the effect of PKCI on radiation sensitivity and c-fos transcription in normal and AT cells. Normal (LM217) and AT (AT58IVA) cells were transfected with PKCI expression plasmid and the overexpression and integration of PKCI was evaluated by northern blotting and polymerase chain reaction, respectively. 5 Gy of radiation was exposed to LM and AT cells transfected with PKCI expression plasmid and cells were harvested 48 hours after radiation and investigated apoptosis with TUNEL method. The c-fos transcription activity was studied by performing CAT assay of reporter gene after transfection of c-fos CAT plasmid into AT and LM cells. Our results demonstrate for the first time a role of PKCI on. the radiation sensitivity and c-fos expression in LM and AT cells. PKCI increased radiation induced apoptosis in LM cells but reduced apoptosis in AT cells. The basal c-fos transcription activity is 70 times lower in AT cells than that in LM cells. The c-fos transcription activity was repressed by overexpression of PKCI in LM cells but not in AT cells. After induction of c-fos by Ras protein, overexpression of PKCI repressed c-fos transcription in LM cells but not in AT cells. Overexpression of PKCI increased radiation sensitivity and repressed c-fos transcription in LM cells but not in AT cells. The results may be a

  5. Cytochrome P450 aromatase expression in human seminoma

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    Montanaro Daniela

    2005-12-01

    Full Text Available Abstract Background The enzyme cytochrome P450 aromatase, catalysing the conversion of androgens into estrogens, has been detected in normal human testicular cells suggesting a physiological role of local estrogen biosynthesis on spermatogenesis control. Estrogens, regulating cell growth and apoptosis, can also be involved in tumorigenesis process, but the possible link between estrogens and testicular neoplastic process is, up to now, scarcely known. This study examined aromatase expression in human seminoma, which is the most common germ cell tumour of the testis. Methods The tumour-bearing testes were obtained from 20 patients with classic seminoma undergoing to therapeutic orchidectomy. Paraffin embedded tissues were processed for immunohistochemistry using a mouse monoclonal antibody generated against human placental cytochrome P450 arom, as primary antibody, and a biotinylated goat-anti-mouse IgG, as secondary antibody. Furthermore, Western blot analysis of seminoma extracts was carried out. Results Intense P450 arom immunoreactivity was observed in the seminoma cells and Western blot analysis confirmed the immunodetection. A strong immunostaining was also detected in cells of intratubular germ cell neoplasia (IGCN, adjacent to seminoma. Conclusion The present study demonstrated, for the first time in human, aromatase expression in neoplastic cells of seminoma suggesting a relation between local estrogen biosynthesis and germ cell tumorigenesis. The P450 arom immunolocalization in the cells of IGCN, representing the common precursor of most germ cell tumors, seems to support these findings.

  6. Perfluorinated chemicals: Differential toxicity, inhibition of aromatase activity and alteration of cellular lipids in human placental cells

    Energy Technology Data Exchange (ETDEWEB)

    Gorrochategui, Eva; Pérez-Albaladejo, Elisabet [Department of Environmental Chemistry, IDAEA–CSIC, 08034 Barcelona, Catalonia (Spain); Casas, Josefina [Department of Biomedicinal Chemistry, IQAC–CSIC, 08034 Barcelona, Catalonia (Spain); Lacorte, Sílvia, E-mail: slbqam@cid.csic.es [Department of Environmental Chemistry, IDAEA–CSIC, 08034 Barcelona, Catalonia (Spain); Porte, Cinta, E-mail: cinta.porte@cid.csic.es [Department of Environmental Chemistry, IDAEA–CSIC, 08034 Barcelona, Catalonia (Spain)

    2014-06-01

    The cytotoxicity of eight perfluorinated chemicals (PFCs), namely, perfluorobutanoic acid (PFBA), perfluorohexanoic acid (PFHxA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorododecanoic acid (PFDoA), perfluorobutanesulfonate (PFBS), perfluorohexanesulfonate (PFHxS) and perfluorooctanesulfonate (PFOS) was assessed in the human placental choriocarcinoma cell line JEG-3. Only the long chain PFCs – PFOS, PFDoA, PFNA, PFOA – showed significant cytotoxicity in JEG-3 cells with EC50 values in the range of 107 to 647 μM. The observed cytotoxicity was to some extent related to a higher uptake of the longer chain PFCs by cells (PFDoA > PFOS ≫ PFNA > PFOA > PFHxA). Moreover, this work evidences a high potential of PFOS, PFOA and PFBS to act as aromatase inhibitors in placental cells with IC50s in the range of 57–80 μM, the inhibitory effect of PFBS being particularly important despite the rather low uptake of the compound by cells. Finally, exposure of JEG-3 cells to a mixture of the eight PFCs (0.6 μM each) led to a relative increase (up to 3.4-fold) of several lipid classes, including phosphatidylcholines (PCs), plasmalogen PC and lyso plasmalogen PC, which suggests an interference of PFCs with membrane lipids. Overall, this work highlights the ability of the PFC mixture to alter cellular lipid pattern at concentrations well below those that generate toxicity, and the potential of the short chain PFBS, often considered a safe substitute of PFOS, to significantly inhibit aromatase activity in placental cells. - Highlights: • Eight perfluorinated chemicals of different chain lengths have been selected. • Long chain ones – PFOS, PFDoA, PFNA, PFOA – were cytotoxic in placenta cells. • The uptake of long chain perfluorinated chemicals by cells was comparatively higher. • PFOS, PFOA and the short chain PFBS significantly inhibited aromatase activity. • A mixture of perfluorinated chemicals significantly altered placenta cell

  7. Sensitivity to the MEK inhibitor E6201 in melanoma cells is associated with mutant BRAF and wildtype PTEN status

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    Byron Sara A

    2012-10-01

    Full Text Available Abstract Background Melanoma is the most lethal form of skin cancer, but recent advances in molecularly targeted agents against the Ras/Raf/MAPK pathway demonstrate promise as effective therapies. Despite these advances, resistance remains an issue, as illustrated recently by the clinical experience with vemurafenib. Such acquired resistance appears to be the result of parallel pathway activation, such as PI3K, to overcome single-agent inhibition. In this report, we describe the cytotoxicity and anti-tumour activity of the novel MEK inhibitor, E6201, in a broad panel of melanoma cell lines (n = 31 of known mutational profile in vitro and in vivo. We further test the effectiveness of combining E6201 with an inhibitor of PI3K (LY294002 in overcoming resistance in these cell lines. Results The majority of melanoma cell lines were either sensitive (IC50 PTEN and mutant BRAF status, whereas mutant RAS and PI3K pathway activation were associated with resistance. Although MEK inhibitors predominantly exert a cytostatic effect, E6201 elicited a potent cytocidal effect on most of the sensitive lines studied, as evidenced by Annexin positivity and cell death ELISA. Conversely, E6201 did not induce cell death in the two resistant melanoma cell lines tested. E6201 inhibited xenograft tumour growth in all four melanoma cell lines studied to varying degrees, but a more pronounced anti-tumour effect was observed for cell lines that previously demonstrated a cytocidal response in vitro. In vitro combination studies of E6201 and LY294002 showed synergism in all six melanoma cell lines tested, as defined by a mean combination index  Conclusions Our data demonstrate that E6201 elicits a predominantly cytocidal effect in vitro and in vivo in melanoma cells of diverse mutational background. Resistance to E6201 was associated with disruption of PTEN and activation of downstream PI3K signalling. In keeping with these data we demonstrate that co-inhibition of

  8. Aromatase inhibition abolishes courtship behaviours in the ring dove (Streptopelia risoria) and reduces androgen and progesterone receptors in the hypothalamus and anterior pituitary gland.

    Science.gov (United States)

    Belle, M D C; Sharp, P J; Lea, R W

    2005-08-01

    The aim of this study was to determine in the ring dove, the effects of aromatase inhibition on the expression of aggressive courtship and nest-soliciting behaviours in relation to the distribution of cells containing immunoreactive androgen (AR) and progesterone (PR) receptor in the hypothalamus and pituitary gland. Isolated sexually experienced ring doves were transferred in opposite sex pairs to individual breeding cages, and then injected with the aromatase inhibitor, fadrozole (four males and four females), or saline vehicle (four males and four females) for 3 days at 12 hourly intervals. Saline-injected control males displayed aggressive courtship behaviours (bow-cooing and hop-charging) and nest-soliciting throughout the study, and control females displayed nest-soliciting. By day 3, fadrozole treatment resulted in the disappearance of all these behaviours and in a decrease or disappearance of AR and PR in the anterior pituitary gland, and in the nucleus preopticus paraventricularis magnocellularis (PPM), nucleus preopticus medialis (POM), nucleus hypothalami lateralis posterioris (PLH), and ventral, lateral and dorsal nucleus tuberalis in the hypothalamus (VTu, LTu, DTu). In the nucleus preopticus anterior (POA), fadrozole treatment decreased AR in both sexes and decreased PR in females but not in males. Cells containing co-localized nuclear AR and PR were found in all hypothalamic areas examined, and in the anterior pituitary gland. Fadrozole is suggested to reduce the local availability of estrogen required indirectly for the induction of AR, and except in cells containing PR in the male POA, for the direct induction of PR. It is suggested that aggressive courtship behaviour is terminated by "cross talk" between aromatase-independent PR and aromatase-dependent AR co-localized in neurons in the POA. Aromatase-independent PR may increase in the male POA in response to visual cues provided by a partner. Aromatase-dependent PR in the POM, and basal

  9. Sensitive assessment of the virologic outcomes of stopping and restarting non-nucleoside reverse transcriptase inhibitor-based antiretroviral therapy.

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    Anna Maria Geretti

    Full Text Available BACKGROUND: Non-nucleoside reverse transcriptase inhibitor (NNRTI-resistant mutants have been shown to emerge after interruption of suppressive NNRTI-based antiretroviral therapy (ART using routine testing. The aim of this study was to quantify the risk of resistance by sensitive testing and correlate the detection of resistance with NNRTI concentrations after treatment interruption and virologic responses after treatment resumption. METHODS: Resistance-associated mutations (RAMs and NNRTI concentrations were studied in plasma from 132 patients who interrupted suppressive ART within SMART. RAMs were detected by Sanger sequencing, allele-specific PCR, and ultra-deep sequencing. NNRTI concentrations were measured by sensitive high-performance liquid chromatography. RESULTS: Four weeks after NNRTI interruption, 19/31 (61.3% and 34/39 (87.2% patients showed measurable nevirapine (>0.25 ng/ml or efavirenz (>5 ng/ml concentrations, respectively. Median eight weeks after interruption, 22/131 (16.8% patients showed ≥1 NNRTI-RAM, including eight patients with NNRTI-RAMs detected only by sensitive testing. The adjusted odds ratio (OR of NNRTI-RAM detection was 7.62 (95% confidence interval [CI] 1.52, 38.30; p = 0.01 with nevirapine or efavirenz concentrations above vs. below the median measured in the study population. Staggered interruption, whereby nucleos(tide reverse transcriptase inhibitors (NRTIs were continued for median nine days after NNRTI interruption, did not prevent NNRTI-RAMs, but increased detection of NRTI-RAMs (OR 4.25; 95% CI 1.02, 17.77; p = 0.03. After restarting NNRTI-based ART (n = 90, virologic suppression rates <400 copies/ml were 8/13 (61.5% with NNRTI-RAMs, 7/11 (63.6% with NRTI-RAMs only, and 51/59 (86.4% without RAMs. The ORs of re-suppression were 0.18 (95% CI 0.03, 0.89 and 0.17 (95% CI 0.03, 1.15 for patients with NNRTI-RAMs or NRTI-RAMs only respectively vs. those without RAMs (p = 0.04. CONCLUSIONS

  10. Highly sensitive measurements of substrates and inhibitors on the basis of tyrosinase sensors and recycling systems

    Science.gov (United States)

    Streffer, Katrin

    2002-12-01

    compounds in river and sea water and the results could correlated very well with the corresponding DIN-test for the determination of phenolic compounds. An other developed tyrosinasesensor showed a very high sensitiveness for catecholamines, substances which are of special importance in the medical diagnostics. In addition, the investigations of two different tyrosinases, which were carried out also in the context of this thesis, have shown, that a special tyrosinase (tyrosinase from Streptomyces antibioticus) will be the better choice as tyrosinase from Agaricus bisporus, which is used in the area of biosensor research till now, if one wants to develop in future even more sensitive tyrosinasesensors. Furthermore, first successes became reached on a molecular biological field, the production of tyrosinasemutants with special, before well-considered features. These successes can be used to develop a new generation of tyrosinasesensors, tyrosinasesensors in which tyrosinase can be bound directionally both to the corresponding physical pickup or also to another enzyme. From this one expects to achieve ways minimized which the substance to be determined (or whose product) otherwise must cover. Finally, this should result in an clearly visible increase of sensitivity of the Biosensor. Analytische Chemie heute meint nicht länger nur die große Messtechnik, die zeit- und kostenintensiv ist, die außerdem nur von qualifiziertem Personal zu bedienen ist und deren Resultate nur durch dieses Personal auswertbar sind. Meist erfordert diese sagen wir 'klassische analytische Messtechnik' auch noch spezielle Räumlichkeiten und oft eine relative große Menge an speziell vorbereiteten Proben. Neben dieser klassischen analytischen Messtechnik hat sich besonders in den letzten Jahren eine auf bestimmte Stoffgruppen und Anforderungen zugeschnittene Messtechnik durchgesetzt, die oft auch durch einen Laien bedient werden kann. Meist sind es sehr kleine Geräte. Auch die ben

  11. Xc- inhibitor sulfasalazine sensitizes colorectal cancer to cisplatin by a GSH-dependent mechanism.

    Science.gov (United States)

    Ma, Ming-zhe; Chen, Gang; Wang, Peng; Lu, Wen-hua; Zhu, Chao-feng; Song, Ming; Yang, Jing; Wen, Shijun; Xu, Rui-hua; Hu, Yumin; Huang, Peng

    2015-11-01

    Sulfasalazine (SSZ) is an anti-inflammatory drug that has been demonstrated to induce apoptosis and tumor regression through inhibition of plasma membrane cystine transporter xc(-). Cysteine is a rate-limiting precursor for intracellular glutathione (GSH) synthesis, which is vital for compound detoxification and maintaining redox balance. Platinum-based chemotherapy is an important regimen used in clinics for various cancers including colorectal cancer (CRC). We hypothesized that targeting xc(-) transporter by SSZ may annihilate cellular detoxification through interruption of GSH synthesis and may enhance the anti-cancer activity of cisplatin (CDDP) by increasing drug transport. In the present study, we revealed that xCT, the active subunit of xc(-), is highly expressed in CRC cell lines and human colorectal carcinoma tissues compared with their normal counterparts. SSZ effectively depleted cellular GSH, leading to significant accumulation of reactive oxygen species and growth inhibition in CRC cells. In contrast, the normal epithelial cells of colon origin were less sensitive to SSZ, showing a moderate ROS elevation. Importantly, SSZ effectively enhanced the intracellular platinum level and cytotoxicity of CDDP in CRC cells. The synergistic effect of SSZ and CDDP was reversed by antioxidant N-acetyl-L-cysteine (NAC). Together, these results suggest that SSZ, a relatively non-toxic drug that targets cystine transporter, may, in combination with CDDP, have effective therapy for colorectal cancer.

  12. Sensitivity pattern of Gram negative bacteria to the new β-lactam/ β-lactamase inhibitor combination: Cefepime/tazobactam

    Directory of Open Access Journals (Sweden)

    Abdul Ghafur

    2012-03-01

    Full Text Available Objectives: Increasing prevalence of carbapenem-resistant Gram negative bacteria has prompted researchers to explorealternative antibiotic options. Different ß-lactam/ß-lactamase inhibitor (BL/BLI combinations are used in manycountries, as a carbapenem saving strategy. The purpose of our study was to evaluate the sensitivity pattern of cefepime/tazobactam combination in comparison to piperacillin/tazobactam, cefoperazone/sulbactam, cefepime andcarbapenem agents.Materials and methods: We conducted retrospective analysis of the sensitivity pattern of Gram negative bacterialisolates in Apollo Speciality Hospital; a 300 bedded, tertiary care Oncology, Neurosurgical and Orthopaedic Centre inSouth India.Results: Out of the 1003 Gram negative, non-repetitive isolates collected over a period of one year; 60.5% were sensitiveto piperacillin-tazobactam, 46.2% to cefepime, 80.4% to cefepime/tazobactam, 71.3% to cefoperazone-sulbactam,79.1% to imipenem and 78.2% to meropenem. Addition of tazobactam increased the susceptibility of cefepime from46.2% to 80.4% in gram negative isolates in general; from 34.4 to 87.9% in E. coli, from 42.3 to 81.0% to Klebsiella, from72.0 to 81.4% in Pseudomonas and 17.2-54.5% to Acinetobacter.Conclusion: Cefepime/tazobactam provided a better invitro sensitivity profile than other BL-BLI combinations studied.This in vitro data needs to be confirmed by clinical studies. J Microbiol Infect Dis 2012; 2(1: 5-8

  13. Disruptions in aromatase expression in the brain, reproductive behavior, and secondary sexual characteristics in male guppies (Poecilia reticulata) induced by tributyltin.

    Science.gov (United States)

    Tian, Hua; Wu, Peng; Wang, Wei; Ru, Shaoguo

    2015-05-01

    Although bioaccumulation of tributyltin (TBT) in fish has been confirmed, information on possible effects of TBT on reproductive system of fish is still relatively scarce, particularly at environmentally relevant levels. To evaluate the adverse effects and intrinsic toxicological properties of TBT in male fish, we studied aromatase gene expression in the brain, sex steroid contents, primary and secondary sexual characteristics, and reproductive behavior in male guppies (Poecilia reticulata) exposed to tributyltin chloride at the nominal concentrations of 5, 50, and 500 ng/L for 28 days in a semi-static exposure system. Radioimmunoassay demonstrated that treatment with 50 ng/L TBT caused an increase in systemic levels of testosterone of male guppies. Gonopodial index, which showed a positive correlation with testosterone levels, was elevated in the 5 ng/L and 50 ng/L TBT treated groups. Real-time PCR revealed that TBT exposure had inhibiting effects on expression of two isoforms of guppy aromatase in the brain, and these changes at the molecular levels were associated with a disturbance of reproductive behavior of the individuals, as measured by decreases in frequencies of posturing, sigmoid display, and chase activities when males were paired with females. This study provides the first evidence that TBT can cause abnormalities of secondary sexual characteristics in teleosts and that suppression of reproductive behavior in teleosts by TBT is due to its endocrine-disrupting action as an aromatase inhibitor targeting the nervous system.

  14. Connecting lignin-degradation pathway with pretreatment inhibitor sensitivity of Cupriavidus necator

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    Wei eWang

    2014-05-01

    Full Text Available To produce lignocellulosic biofuels economically, the complete release of monomers from the plant cell wall components, cellulose, hemicellulose and lignin, through pretreatment and hydrolysis (both enzymatic and chemical, and the efficient utilization of these monomers as carbon sources, is crucial. In addition, the identification and development of robust microbial biofuel production strains that can tolerate the toxic compounds generated during pretreatment and hydrolysis is also essential. In this work, Cupriavidus necator was selected due to its capabilities for utilizing lignin monomers and producing polyhydroxylbutyrate (PHB, a bioplastic as well as an advanced biofuel intermediate. We characterized the growth kinetics of C. necator in pretreated corn stover slurry as well as individually in the presence of 11 potentially toxic compounds in the saccharified slurry. We found that C. necator was sensitive to the saccharified slurry produced from dilute acid pretreated corn stover. Five out of 11 compounds within the slurry were characterized as toxic to C. necator, namely ammonium acetate, furfural, hydroxymethylfurfural (HMF, benzoic acid, and p-coumaric acid. Aldehydes (e.g., furfural and HMF were more toxic than the acetate and the lignin degradation products benzoic acid and p-coumaric acid; furfural was identified as the most toxic compound. Although toxic to C. necator at high concentration, ammonium acetate, benzoic acid, and p-coumaric acid could be utilized by C. necator with a stimulating effect on C. necator growth. Consequently, the lignin degradation pathway of C. necator was reconstructed based on genomic information and literature. The efficient conversion of intermediate catechol to downstream products of cis,cis-muconate or 2-hydroxymuconate-6-semialdehyde may help improve the robustness of C. necator to benzoic acid and p-coumaric acid as well as improve PHB productivity.

  15. Connecting Lignin-Degradation Pathway with Pre-Treatment Inhibitor Sensitivity of Cupriavidus necator

    Energy Technology Data Exchange (ETDEWEB)

    Wang, W. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Yang, S. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Hunsinger, G. B. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Pienkos, P. T. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Johnson, D. K. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2014-05-27

    In order to produce lignocellulosic biofuels economically, the complete release of monomers from the plant cell wall components, cellulose, hemicellulose, and lignin, through pre-treatment and hydrolysis (both enzymatic and chemical), and the efficient utilization of these monomers as carbon sources, is crucial. In addition, the identification and development of robust microbial biofuel production strains that can tolerate the toxic compounds generated during pre-treatment and hydrolysis is also essential. In this work, Cupriavidus necator was selected due to its capabilities for utilizing lignin monomers and producing polyhydroxylbutyrate (PHB), a bioplastic as well as an advanced biofuel intermediate. We characterized the growth kinetics of C. necator in pre-treated corn stover slurry as well as individually in the pre-sence of 11 potentially toxic compounds in the saccharified slurry. We found that C. necator was sensitive to the saccharified slurry produced from dilute acid pre-treated corn stover. Five out of 11 compounds within the slurry were characterized as toxic to C. necator, namely ammonium acetate, furfural, hydroxymethylfurfural (HMF), benzoic acid, and p-coumaric acid. Aldehydes (e.g., furfural and HMF) were more toxic than the acetate and the lignin degradation products benzoic acid and p-coumaric acid; furfural was identified as the most toxic compound. Although toxic to C. necator at high concentration, ammonium acetate, benzoic acid, and p-coumaric acid could be utilized by C. necator with a stimulating effect on C. necator growth. Consequently, the lignin degradation pathway of C. necator was reconstructed based on genomic information and literature. The efficient conversion of intermediate catechol to downstream products of cis,cis-muconate or 2-hydroxymuconate-6-semialdehyde may help improve the robustness of C. necator to benzoic acid and p-coumaric acid as well as improve PHB productivity.

  16. Synthesis of highly-labeled with tritium steroid hormones and their use for estimation of aromatase activity

    International Nuclear Information System (INIS)

    Highly-labeled steroids - progesterone, estradiol, and androsterone are synthesized. They are used for determination of aromatase activity in different pathologies. It is shown that high activity of aromatase in endometrium in patients with endometrium neoplasms without myome deteriorates disease prognosis. At the same time high aromatase activity in endometrium in patients with endometrium neoplasms with myome has frequently opportune result

  17. Aromatase enzyme expression in acromegaly and its possible relationship with disease prognosis.

    Science.gov (United States)

    Selek, Alev; Cetinarslan, Berrin; Gurbuz, Yesim; Tarkun, Ilhan; Canturk, Zeynep; Cabuk, Burak

    2015-05-01

    The purpose of this study was to evaluate aromatase enzyme expression in growth hormone (GH) secreting adenomas and comparison with prolactinomas, nonfunctional adenomas, and normal pituitary tissues. Also the impact of its expression on clinical and prognostic features was evaluated. 38 acromegaly, 26 prolactinoma, and 31 nonfunctional pituitary adenoma and 11 normal pituitary gland samples from autopsies were included. Aromatase and estrogen receptor-alpha (ERα) were evaluated by Immunohistochemical method; demographic, pre- and postoperative features of the patients were noted. Aromatase was expressed in varying degrees in all cases in study including controls. Aromatase expression in patients with acromegaly was significantly higher than patients with prolactinoma, nonfunctional adenoma, and controls (p = 0.04, p = 0.01 and p acromegaly, aromatase expression was negatively correlated with ER-alpha (p = 0.02, r = -0.34). Also, Ki-67 immunohistochemical results were negatively correlated with aromatase expression (p = 0.03, r = -0.27) while positively correlated with ER expression (p acromegaly. In patients with acromegaly and prolactinoma, aromatase expression was negatively correlated with Ki-67 score, and also it was higher in patients with complete postoperative remission than without remission. Therefore, aromatase expression may be a good prognostic marker predominantly in acromegaly.

  18. Effects of Nutrition Relevant Mixtures of Phytoestrogens on Steroidogenesis, Aromatase, Estrogen, and Androgen Activity

    DEFF Research Database (Denmark)

    Taxvig, Camilla; Engell-Kofoed, Anders Elleby; Sonne-Hansen, Katrine;

    2010-01-01

    aromatase activity. Furthermore, exposure of the H295R cells to isoflavonoids caused a decrease in testosterone production, and various mixtures of PEs significantly stimulated MCF-7 human breast adenocarcinoma cell growth and induced aromatase activity in JEG-3 choriocarcinoma cells. The estrogenic effect...

  19. HIV Protease Inhibitors Sensitize Human Head and Neck Squamous Carcinoma Cells to Radiation by Activating Endoplasmic Reticulum Stress.

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    Runping Liu

    Full Text Available Human head and neck squamous cell carcinoma (HNSCC is the sixth most malignant cancer worldwide. Despite significant advances in the delivery of treatment and surgical reconstruction, there is no significant improvement of mortality rates for this disease in the past decades. Radiotherapy is the core component of the clinical combinational therapies for HNSCC. However, the tumor cells have a tendency to develop radiation resistance, which is a major barrier to effective treatment. HIV protease inhibitors (HIV PIs have been reported with radiosensitizing activities in HNSCC cells, but the underlying cellular/molecular mechanisms remain unclear. Our previous study has shown that HIV PIs induce cell apoptosis via activation of endoplasmic reticulum (ER stress. The aim of this study was to examine the role of ER stress in HIV PI-induced radiosensitivity in human HNSCC.HNSCC cell lines, SQ20B and FaDu, and the most commonly used HIV PIs, lopinavir and ritonavir (L/R, were used in this study. Clonogenic assay was used to assess the radiosensitivity. Cell viability, apoptosis and cell cycle were analyzed using Cellometer Vision CBA. The mRNA and protein levels of ER stress-related genes (eIF2α, CHOP, ATF-4, and XBP-1, as well as cell cycle related protein, cyclin D1, were detected by real time RT-PCR and Western blot analysis, respectively. The results demonstrated that L/R dose-dependently sensitized HNSCC cells to irradiation and inhibited cell growth. L/R-induced activation of ER stress was correlated to down-regulation of cyclin D1 expression and cell cycle arrest under G0/G1 phase.HIV PIs sensitize HNSCC cells to radiotherapy by activation of ER stress and induction of cell cycle arrest. Our results provided evidence that HIV PIs can be potentially used in combination with radiation in the treatment of HNSCC.

  20. p62/SQSTM1 accumulation in squamous cell carcinoma of head and neck predicts sensitivity to phosphatidylinositol 3-kinase pathway inhibitors.

    Directory of Open Access Journals (Sweden)

    Wen-Liang Kuo

    Full Text Available The phosphoinositol-3 kinase (PI3K pathway is highly dysregulated in squamous cell carcinoma of the head and neck (SCCHN. While inhibitors of the PI3K/AKT pathway are being developed in cancer, their efficacy does not appear to be related to the presence of mutations or amplification in pathway genes. The PI3K pathway is a major regulator of macro-autophagy, an evolutionarily conserved catabolic process that degrades cellular materials to promote cellular homeostasis and survival under stress. Employing a panel of SCCHN cell lines, we observed a significant correlation between the activity of PI3K/AKT inhibitors and their ability to induce autophagy. More specifically, resistance to these inhibitors was associated with accumulation of p62/SQSTM1, a pleotropic protein that is consumed during autophagy, while loss of autophagy was, for the first time, found to be due to silencing of an essential autophagy gene, ATG7. Moreover, modulating ATG7 and p62/SQSTM1 could regulate sensitivity to PI3K/AKT inhibitors, underscoring a mechanistic link between autophagy and drug sensitivity. Analysis of human tissues revealed progressive accumulation of p62/SQSTM1 in a significant proportion of cancer samples compared to normal tissue, suggesting that defective autophagy has relevance to SCCHN. These findings are further validated by analysis of TCGA data confirming homozygous deletion and mRNA down-regulation of ATG7 in 10.0% of SCCHN samples. Taken together, these data indicate that p62/SQSTM1 levels modulate sensitivity to PI3K/AKT inhibitors; cancers vary in their capacity to undergo autophagy through epigenetic modification and, when deficient, accumulate p62/SQSTM1; and expression of autophagy-related proteins may serve as markers for resistance to PI3K/AKT inhibitors in SCCHN.

  1. MSH3 mismatch repair protein regulates sensitivity to cytotoxic drugs and a histone deacetylase inhibitor in human colon carcinoma cells.

    Directory of Open Access Journals (Sweden)

    Jae Myung Park

    Full Text Available BACKGROUND: MSH3 is a DNA mismatch repair (MMR gene that undergoes frequent somatic mutation in colorectal cancers (CRCs with MMR deficiency. MSH3, together with MSH2, forms the MutSβ heteroduplex that interacts with interstrand cross-links induced by drugs such as cisplatin. To date, the impact of MSH3 on chemosensitivity is unknown. METHODS: We utilized isogenic HCT116 (MLH1-/MSH3- cells where MLH1 is restored by transfer of chromosome 3 (HCT116+ch3 and also MSH3 by chromosome 5 (HCT116+3+5. We generated HCT116+3+5, SW480 (MLH1+/MSH3+ and SW48 (MLH1-/MSH3+ cells with shRNA knockdown of MSH3. Cells were treated with 5-fluorouracil (5-FU, SN-38, oxaliplatin, or the histone deacetylase (HDAC inhibitor PCI-24781 and cell viability, clonogenic survival, DNA damage and apoptosis were analyzed. RESULTS: MSH3-deficient vs proficient CRC cells showed increased sensitivity to the irinotecan metabolite SN-38 and to oxaliplatin, but not 5-FU, as shown in assays for apoptosis and clonogenic survival. In contrast, suppression of MLH1 attenuated the cytotoxic effect of 5-FU, but did not alter sensitivity to SN-38 or oxaliplatin. The impact of MSH3 knockdown on chemosensitivity to SN-38 and oxaliplatin was maintained independent of MLH1 status. In MSH3-deficient vs proficient cells, SN-38 and oxaliplatin induced higher levels of phosphorylated histone H2AX and Chk2, and similar results were found in MLH1-proficient SW480 cells. MSH3-deficient vs proficient cells showed increased 53BP1 nuclear foci after irradiation, suggesting that MSH3 can regulate DNA double strand break (DSB repair. We then utilized PCI-24781 that interferes with homologous recombination (HR indicated by a reduction in Rad51 expression. The addition of PCI-24781 to oxaliplatin enhanced cytotoxicity to a greater extent compared to either drug alone. CONCLUSION: MSH3 status can regulate the DNA damage response and extent of apoptosis induced by chemotherapy. The ability of MSH3 to regulate

  2. The hepatitis B virus ribonuclease H is sensitive to inhibitors of the human immunodeficiency virus ribonuclease H and integrase enzymes.

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    John E Tavis

    2013-01-01

    Full Text Available Nucleos(tide analog therapy blocks DNA synthesis by the hepatitis B virus (HBV reverse transcriptase and can control the infection, but treatment is life-long and has high costs and unpredictable long-term side effects. The profound suppression of HBV by the nucleos(tide analogs and their ability to cure some patients indicates that they can push HBV to the brink of extinction. Consequently, more patients could be cured by suppressing HBV replication further using a new drug in combination with the nucleos(tide analogs. The HBV ribonuclease H (RNAseH is a logical drug target because it is the second of only two viral enzymes that are essential for viral replication, but it has not been exploited, primarily because it is very difficult to produce active enzyme. To address this difficulty, we expressed HBV genotype D and H RNAseHs in E. coli and enriched the enzymes by nickel-affinity chromatography. HBV RNAseH activity in the enriched lysates was characterized in preparation for drug screening. Twenty-one candidate HBV RNAseH inhibitors were identified using chemical structure-activity analyses based on inhibitors of the HIV RNAseH and integrase. Twelve anti-RNAseH and anti-integrase compounds inhibited the HBV RNAseH at 10 µM, the best compounds had low micromolar IC(50 values against the RNAseH, and one compound inhibited HBV replication in tissue culture at 10 µM. Recombinant HBV genotype D RNAseH was more sensitive to inhibition than genotype H. This study demonstrates that recombinant HBV RNAseH suitable for low-throughput antiviral drug screening has been produced. The high percentage of compounds developed against the HIV RNAseH and integrase that were active against the HBV RNAseH indicates that the extensive drug design efforts against these HIV enzymes can guide anti-HBV RNAseH drug discovery. Finally, differential inhibition of HBV genotype D and H RNAseHs indicates that viral genetic variability will be a factor during drug

  3. The effects of protein phosphatase inhibitors on the duration of central sensitization of rat dorsal horn neurons following injection of capsaicin

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    Fang Li

    2006-07-01

    Full Text Available Abstract Protein kinases and phosphatases catalyze opposing reactions of phosphorylation and dephosphorylation, which may modulate the function of crucial signaling proteins in central nervous system. This is an important mechanism in the regulation of intracellular signal transduction pathways in nociceptive neurons. To explore the role of protein phosphatase in central sensitization of spinal nociceptive neurons following peripheral noxious stimulation, using electrophysiological recording techniques, we investigated the role of two inhibitors of protein phosphatase type 2A (PP2A, fostriecin and okadaic acid (OA, on the responses of dorsal horn neurons to mechanical stimuli in anesthetized rats following intradermal injection of capsaicin. Central sensitization was initiated by injection of capsaicin into the plantar surface of the left paw. A microdialysis fiber was implanted in the spinal cord dorsal horn for perfusion of ACSF and inhibitors of PP2A, fostriecin and okadaic acid. We found that in ACSF pretreated animals, the responses to innocuous and noxious stimuli following capsaicin injection increased over a period of 15 min after injection and had mostly recovered by 60 min later. However, pre- or post-treatment with the phosphatase inhibitors, fostriecin or OA, significantly enhanced the effects of capsaicin injection by prolonging the responses to more than 3 hours. These results confirm that blockade of protein phosphatase activity may potentiate central sensitization of nociceptive transmission in the spinal cord following capsaicin injection and indicate that protein phosphatase type 2A may be involved in determining the duration of capsaicin-induced central sensitization.

  4. Aromatase inhibition remodels the clonal architecture of estrogen-receptor-positive breast cancers

    Science.gov (United States)

    Miller, Christopher A.; Gindin, Yevgeniy; Lu, Charles; Griffith, Obi L; Griffith, Malachi; Shen, Dong; Hoog, Jeremy; Li, Tiandao; Larson, David E.; Watson, Mark; Davies, Sherri R; Hunt, Kelly; Suman, Vera J.; Snider, Jacqueline; Walsh, Thomas; Colditz, Graham A.; DeSchryver, Katherine; Wilson, Richard K.; Mardis, Elaine R.; Ellis, Matthew J.

    2016-01-01

    Resistance to oestrogen-deprivation therapy is common in oestrogen-receptor-positive (ER+) breast cancer. To better understand the contributions of tumour heterogeneity and evolution to resistance, here we perform comprehensive genomic characterization of 22 primary tumours sampled before and after 4 months of neoadjuvant aromatase inhibitor (NAI) treatment. Comparing whole-genome sequencing of tumour/normal pairs from the two time points, with coincident tumour RNA sequencing, reveals widespread spatial and temporal heterogeneity, with marked remodelling of the clonal landscape in response to NAI. Two cases have genomic evidence of two independent tumours, most obviously an ER− ‘collision tumour', which was only detected after NAI treatment of baseline ER+ disease. Many mutations are newly detected or enriched post treatment, including two ligand-binding domain mutations in ESR1. The observed clonal complexity of the ER+ breast cancer genome suggests that precision medicine approaches based on genomic analysis of a single specimen are likely insufficient to capture all clinically significant information. PMID:27502118

  5. Ron knockdown and Ron monoclonal antibody IMC-RON8 sensitize pancreatic cancer to histone deacetylase inhibitors (HDACi.

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    Yi Zou

    Full Text Available Recepteur d'origine nantais (Ron is overexpressed in a panel of pancreatic cancer cells and tissue samples from pancreatic cancer patients. Ron can be activated by its ligand macrophage stimulating protein (MSP, thereby activating oncogenic signaling pathways. Crosstalk between Ron and EGFR, c-Met, or IGF-1R may provide a mechanism underlying drug resistance. Thus, targeting Ron may represent a novel therapeutic strategy. IMC-RON8 is the first Ron monoclonal antibody (mAb entering clinical trial for targeting Ron overexpression. Our studies show IMC-RON8 downmodulated Ron expression in pancreatic cancer cells and significantly blocked MSP-stimulated Ron activation, downstream Akt and ERK phosphorylation, and survivin mRNA expression. IMC-RON8 hindered MSP-induced cell migration and reduced cell transformation. Histone deacetylase inhibitors (HDACi are reported to target expression of various genes through modification of nucleosome histones and non-histone proteins. Our work shows HDACi TSA and Panobinostat (PS decreased Ron mRNA and protein expression in pancreatic cancer cells. PS also reduced downstream signaling of pAkt, survivin, and XIAP, as well as enhanced cell apoptosis. Interestingly, PS reduced colony formation in Ron knockdown cells to a greater extent than Ron scramble control cells in colony formation and soft agarose assays. IMC-RON8 could also sensitize pancreatic cancer cells to PS, as reflected by reduced colony numbers and size in combination treatment with IMC-RON8 and PS compared to single treatment alone. The co-treatment further reduced Ron expression and pAkt, and increased PARP cleavage compared to either treatment alone. This study suggests the potential for a novel combination approach which may ultimately be of value in treatment of pancreatic cancer.

  6. Ron knockdown and Ron monoclonal antibody IMC-RON8 sensitize pancreatic cancer to histone deacetylase inhibitors (HDACi).

    Science.gov (United States)

    Zou, Yi; Howell, Gillian M; Humphrey, Lisa E; Wang, Jing; Brattain, Michael G

    2013-01-01

    Recepteur d'origine nantais (Ron) is overexpressed in a panel of pancreatic cancer cells and tissue samples from pancreatic cancer patients. Ron can be activated by its ligand macrophage stimulating protein (MSP), thereby activating oncogenic signaling pathways. Crosstalk between Ron and EGFR, c-Met, or IGF-1R may provide a mechanism underlying drug resistance. Thus, targeting Ron may represent a novel therapeutic strategy. IMC-RON8 is the first Ron monoclonal antibody (mAb) entering clinical trial for targeting Ron overexpression. Our studies show IMC-RON8 downmodulated Ron expression in pancreatic cancer cells and significantly blocked MSP-stimulated Ron activation, downstream Akt and ERK phosphorylation, and survivin mRNA expression. IMC-RON8 hindered MSP-induced cell migration and reduced cell transformation. Histone deacetylase inhibitors (HDACi) are reported to target expression of various genes through modification of nucleosome histones and non-histone proteins. Our work shows HDACi TSA and Panobinostat (PS) decreased Ron mRNA and protein expression in pancreatic cancer cells. PS also reduced downstream signaling of pAkt, survivin, and XIAP, as well as enhanced cell apoptosis. Interestingly, PS reduced colony formation in Ron knockdown cells to a greater extent than Ron scramble control cells in colony formation and soft agarose assays. IMC-RON8 could also sensitize pancreatic cancer cells to PS, as reflected by reduced colony numbers and size in combination treatment with IMC-RON8 and PS compared to single treatment alone. The co-treatment further reduced Ron expression and pAkt, and increased PARP cleavage compared to either treatment alone. This study suggests the potential for a novel combination approach which may ultimately be of value in treatment of pancreatic cancer.

  7. Role of chromatin structure modulation by the histone deacetylase inhibitor trichostatin A on the radio-sensitivity of ataxia telangiectasia

    Energy Technology Data Exchange (ETDEWEB)

    Meschini, Roberta, E-mail: meschini@unitus.it; Morucci, Elisa; Berni, Andrea; Lopez-Martinez, Wilner; Palitti, Fabrizio

    2015-07-15

    Highlights: • Role of chromatin compaction on chromosomal instability. • Reduced radiation-induced clastogenicity in Ataxia telangiectasia cell lines. • Histone tails hyperacetylation reduces heterochromatin content favouring DSBs repair. - Abstract: At present, a lot is known about biochemical aspects of double strand breaks (DBS) repair but how chromatin structure affects this process and the sensitivity of DNA to DSB induction is still an unresolved question. Ataxia telangiectasia (A-T) patients are characterised by very high sensitivity to DSB-inducing agents such as ionising radiation. This radiosensitivity is revealed with an enhancement of chromosomal instability as a consequence of defective DNA repair for a small fraction of breaks located in the heterochromatin, where they are less accessible. Besides, recently it has been reported that Ataxia Telangiectasia Mutated (ATM) mediated signalling modifies chromatin structure. In order to study the impact of chromatin compaction on the chromosomal instability of A-T cells, the response to trichostatin-A, an histone deacetylase inhibitor, in normal and A-T lymphoblastoid cell lines was investigated testing its effect on chromosomal aberrations, cell cycle progression, DNA damage and repair after exposure to X-rays. The results suggest that the response to both trichostatin-A pre- and continuous treatments is independent of the presence of either functional or mutated ATM protein, as the reduction of chromosomal damage was found also in the wild-type cell line. The presence of trichostatin-A before exposure to X-rays could give rise to prompt DNA repair functioning on chromatin structure already in an open conformation. Differently, trichostatin-A post-treatment causing hyperacetylation of histone tails and reducing the heterochromatic DNA content might diminish the requirement for ATM and favour DSBs repair reducing chromosomal damage only in A-T cells. This fact could suggest that trichostatin-A post

  8. High-Resolution Mapping of RNA Polymerases Identifies Mechanisms of Sensitivity and Resistance to BET Inhibitors in t(8;21) AML.

    Science.gov (United States)

    Zhao, Yue; Liu, Qi; Acharya, Pankaj; Stengel, Kristy R; Sheng, Quanhu; Zhou, Xiaofan; Kwak, Hojoong; Fischer, Melissa A; Bradner, James E; Strickland, Stephen A; Mohan, Sanjay R; Savona, Michael R; Venters, Bryan J; Zhou, Ming-Ming; Lis, John T; Hiebert, Scott W

    2016-08-16

    Bromodomain and extra-terminal domain (BET) family inhibitors offer an approach to treating hematological malignancies. We used precision nuclear run-on transcription sequencing (PRO-seq) to create high-resolution maps of active RNA polymerases across the genome in t(8;21) acute myeloid leukemia (AML), as these polymerases are exceptionally sensitive to BET inhibitors. PRO-seq identified over 1,400 genes showing impaired release of promoter-proximal paused RNA polymerases, including the stem cell factor receptor tyrosine kinase KIT that is mutated in t(8;21) AML. PRO-seq also identified an enhancer 3' to KIT. Chromosome conformation capture confirmed contacts between this enhancer and the KIT promoter, while CRISPRi-mediated repression of this enhancer impaired cell growth. PRO-seq also identified microRNAs, including MIR29C and MIR29B2, that target the anti-apoptotic factor MCL1 and were repressed by BET inhibitors. MCL1 protein was upregulated, and inhibition of BET proteins sensitized t(8:21)-containing cells to MCL1 inhibition, suggesting a potential mechanism of resistance to BET-inhibitor-induced cell death. PMID:27498870

  9. Optimal Classes of Chemotherapeutic Agents Sensitized by Specific Small-Molecule Inhibitors of Akt In Vitro and In Vivo

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    Yan Shi

    2005-11-01

    Full Text Available Akt is a serine/threonine kinase that transduces survival signals from survival/growth factors. Deregulation and signal imbalance in cancer cells make them prone to apoptosis. Upregulation or activation of Akt to aid the survival of cancer cells is a common theme in human malignancies. We have developed small-molecule Akt inhibitors that are potent and specific. These Akt inhibitors can inhibit Akt activity and block phosphorylation by Akt on multiple downstream targets in cells. Synergy in apoptosis induction was observed when Akt inhibitors were combined with doxorubicin or camptothecin. Akt inhibitor-induced enhancement of topoisomerase inhibitor cytotoxicity was also evident in long-term cell survival assay. Synergy with paclitaxel in apoptosis induction was evident in cells pretreated with paclitaxel, and enhancement of tumor delay by paclitaxel was demonstrated through cotreatment with Akt inhibitor Compound A (A-443654. Combination with other classes of chemotherapeutic agents did not yield any enhancement of cytotoxicity. These findings provide important guidance in selecting appropriate classes of chemotherapeutic agents for combination with Akt inhibitors in cancer treatment.

  10. A subset of cancer cell lines is acutely sensitive to the Chk1 inhibitor MK-8776 as monotherapy due to CDK2 activation in S phase.

    Science.gov (United States)

    Sakurikar, Nandini; Thompson, Ruth; Montano, Ryan; Eastman, Alan

    2016-01-12

    DNA damage activates Checkpoint kinase 1 (Chk1) to halt cell cycle progression thereby preventing further DNA replication and mitosis until the damage has been repaired. Consequently, Chk1 inhibitors have emerged as promising anticancer therapeutics in combination with DNA damaging drugs, but their single agent activity also provides a novel approach that may be particularly effective in a subset of patients. From analysis of a large panel of cell lines, we demonstrate that 15% are very sensitive to the Chk1 inhibitor MK-8776. Upon inhibition of Chk1, sensitive cells rapidly accumulate DNA double-strand breaks in S phase in a CDK2- and cyclin A-dependent manner. In contrast, resistant cells can continue to grow for at least 7 days despite continued inhibition of Chk1. Resistance can be circumvented by inhibiting Wee1 kinase and thereby directly activating CDK2. Hence, sensitivity to Chk1 inhibition is regulated upstream of CDK2 and correlates with accumulation of CDC25A. We conclude that cells poorly tolerate CDK2 activity in S phase and that a major function of Chk1 is to ensure it remains inactive. Indeed, inhibitors of CDK1 and CDK2 arrest cells in G1 or G2, respectively, but do not prevent progression through S phase demonstrating that neither kinase is required for S phase progression. Inappropriate activation of CDK2 in S phase underlies the sensitivity of a subset of cell lines to Chk1 inhibitors, and this may provide a novel therapeutic opportunity for appropriately stratified patients. PMID:26595527

  11. Apoptosis-related molecular differences for response to tyrosin kinase inhibitors in drug-sensitive and drug-resistant human bladder cancer cells

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    Jixia Li

    2013-01-01

    Full Text Available Context: The epidermal growth factor receptor (EGFR family is reportedly overexpressed in bladder cancer, and tyrosine kinaseinhibitors (TKIs have been suggested as treatment. Gefitinib is a selective inhibitor of the EGFR and lapatinib is a dual inhibitor of both the EGFR and HER2 (human EGFR type 2 receptor. Both compounds compete with the binding of adenosine triphosphate (ATP to the tyrosine kinase domain of the respective receptors to inhibit receptor autophosphorylation causing suppression of signal transduction. Unfortunately, resistance to these inhibitors is a major clinical problem. Aims: To compare the apoptosis signaling pathway(s induced by gefitinib and lapatinib, in UM-UC-5 (drug-sensitive and UM-UC-14 (drug-resistant bladder cancer cells and to identify molecular differences that might be useful predictors of their efficacy. Materials and Methods: Cell proliferation, cell cycle and apoptosis assay were used to detect the effect of TKIs on UM-UC-5 and UM-UC-14 cells. Molecular differences for response to TKIs were examined by protein array. Results: TKIs strongly inhibited cell proliferation and induced cell cycle G1 arrest and apoptosis in UM-UC-5 cells. Most notable apoptosis molecular differences included decreased claspin, trail, and survivin by TKIs in the sensitive cells. In contrast, TKIs had no effect on resistant cells. Conclusions: Claspin, trail, and survivin might be used to determine the sensitivity of bladder cancers to TKIs.

  12. A small molecule inhibitor of RAD51 reduces homologous recombination and sensitizes multiple myeloma cells to doxorubicin

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    David A. Alagpulinsa

    2014-10-01

    Full Text Available We previously reported high expression of RAD51 and increased homologous recombination (HR rates in multiple myeloma (MM cells, and showed that genomic instability and disease progression are commensurate with HR levels. Moreover, high RAD51 expression in vivo is associated with chemoresistance and poor patient survival. Doxorubicin (DOX is one of the most widely used drug treatments in MM chemotherapy. DOX is cytotoxic because it induces DNA double-strand breaks, which can be repaired by RAD51-mediated HR; activation of this pathway thus contributes to resistance. To investigate the role of RAD51 in MM drug resistance, we assessed the ability of B02, a small-molecule inhibitor of RAD51, to enhance DOX sensitivity of MM cells. Combining low-toxicity doses of DOX and B02 resulted in significant synthetic lethality, observed as increased apoptosis and reduced viability compared to either agent alone, or to the product of their individual effects. In contrast, the combination did not produce significant synergy against normal human CD19+ B cells from peripheral blood. DOX induced RAD51 at both mRNA and protein levels, while arresting cells in S and G2. DOX treatment also increased the number of RAD51 foci, a marker of HR repair, so that the fraction of cells with ≥5 foci rose 4-fold, whereas γH2AX foci rose far less, implying that most new breaks are repaired. When B02 treatment preceded DOX exposure, the induction of RAD51 foci was severely blunted, whereas γH2AX foci rose significantly relative to basal levels or either agent alone. In MM cells carrying a chromosomally integrated reporter of HR repair, DOX increased HR events while B02 inhibition of RAD51 blocked the HR response. These studies demonstrate the crucial role of RAD51 in protecting MM cells from genotoxic agents such as DOX, and suggest that specific inhibition of RAD51 may be an effective means to block DNA repair in MM cells and thus to enhance the efficacy of chemotherapy.

  13. Effects of aromatase inhibition on spatial working memory and hippocampal astrocyte numbers

    OpenAIRE

    José I. Arias; Héctor González-Pardo; Nélida M. Conejo; Jorge L. Arias

    2012-01-01

    Sex hormones are known to induce the sexual differentiation of the brain during early development in mammals. Testosterone secreted by males already during gestation is classically believed to contribute to brain and behavioural sexual differentiation thanks to its conversion to estradiol by the enzyme aromatase. However, there is evidence suggesting that aromatase inhibition may also impair cognitive functions in women receiving hormonal treatment for breast cancer. In order to evaluate the ...

  14. Correlation between aromatase expression in the eutopic endometrium of symptomatic patients and the presence of endometriosis

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    Maia Jr H

    2012-02-01

    Full Text Available Hugo Maia Jr1,2, Clarice Haddad1,2, Julio Casoy11CEPARH, 2Itaigara Memorial Day Hospital, Salvador, Bahia, BrazilObjective: To investigate whether aromatase expression in the eutopic endometrium correlates with the presence and severity of endometriosis in patients with infertility and/or dysmenorrhea undergoing laparoscopy and hysteroscopy.Patients: The study involved 106 patients of reproductive age with symptoms of dysmenorrhea and infertility. Sixteen endometriosis-free asymptomatic patients were used as a control group.Methods: Concomitant laparoscopy and hysteroscopy was carried out in all cases. An endometrial biopsy was taken to determine aromatase p450 expression by immunohistochemistry. Endometriosis was staged according to the American Society of Reproductive Medicine classification.Results: Endometriosis was diagnosed by laparoscopy in 92/106 symptomatic patients. In this group, aromatase expression was detected in the eutopic endometrium of 66/92 patients with endometriosis (72% and in 13/14 (95% patients in the symptomatic, endometriosis-free group (P = 0.09. Aromatase expression was not detected in any patients from the control group. In the endometriosis group, aromatase expression was detected in the eutopic endometrium of 28/45 patients (62% with American Society of Reproductive Medicine classification stage 1 of the disease, in 11/14 patients (78% with stage II, 14/20 patients (70% with stage III, and in 12/13 patients (92% with stage IV; however, the difference was only statistically significant between stages I and IV (P = 0.04.Conclusion: Aromatase expression in the endometrium was associated with the presence of dysmenorrhea and infertility irrespective of the presence of endometriosis. When endometriosis was present, however, there was a tendency for aromatase expression to be positively correlated with dysmenorrhea severity.Keywords: aromatase, endometrium, endometriosis, Cox-2, dysmenorrhea

  15. Constitutional genetic variation at the human aromatase gene (Cyp19) and breast cancer risk

    OpenAIRE

    Siegelmann-Danieli, N; Buetow, K H

    1999-01-01

    The activity of the aromatase enzyme, which converts androgens into oestrogens and has a major role in regulating oestrogen levels in the breast, is thought to be a contributing factor in the development of breast cancer. We undertook this study to assess the role of constitutional genetic variation in the human aromatase gene (Cyp19) in the development of this disease. Our genotyping of 348 cases with breast cancer and 145 controls (all Caucasian women) for a published tetranucleotide repeat...

  16. Overexpression of aromatase alone is sufficient for ovarian development in genetically male chicken embryos.

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    Luke S Lambeth

    Full Text Available Estrogens play a key role in sexual differentiation of both the gonads and external traits in birds. The production of estrogen occurs via a well-characterised steroidogenic pathway, which is a multi-step process involving several enzymes, including cytochrome P450 aromatase. In chicken embryos, the aromatase gene (CYP19A1 is expressed female-specifically from the time of gonadal sex differentiation. To further explore the role of aromatase in sex determination, we ectopically delivered this enzyme using the retroviral vector RCASBP in ovo. Aromatase overexpression in male chicken embryos induced gonadal sex-reversal characterised by an enlargement of the left gonad and development of ovarian structures such as a thickened outer cortex and medulla with lacunae. In addition, the expression of key male gonad developmental genes (DMRT1, SOX9 and Anti-Müllerian hormone (AMH was suppressed, and the distribution of germ cells in sex-reversed males followed the female pattern. The detection of SCP3 protein in late stage sex-reversed male embryonic gonads indicated that these genetically male germ cells had entered meiosis, a process that normally only occurs in female embryonic germ cells. This work shows for the first time that the addition of aromatase into a developing male embryo is sufficient to direct ovarian development, suggesting that male gonads have the complete capacity to develop as ovaries if provided with aromatase.

  17. NPM/ALK mutants resistant to ASP3026 display variable sensitivity to alternative ALK inhibitors but succumb to the novel compound PF-06463922.

    Science.gov (United States)

    Mologni, Luca; Ceccon, Monica; Pirola, Alessandra; Chiriano, Gianpaolo; Piazza, Rocco; Scapozza, Leonardo; Gambacorti-Passerini, Carlo

    2015-03-20

    ALK is involved in the onset of several tumors. Crizotinib (XalkoriTM), a potent ALK inhibitor, represents the current front-line treatment for ALK+ NSCLC and shows great clinical efficacy. However, resistant disease often develops after initial response. ASP3026 is a novel second-generation ALK inhibitor with activity on crizotinib-resistant ALK-L1196M gatekeeper mutant. As resistance is likely to be a relevant hurdle for any drug, we sought to determine the resistance profile of ASP3026 in the context of NPM/ALK+ ALCL. We selected six ASP3026-resistant cell lines by culturing human ALCL cells in the presence of increasing concentrations of drug. The established resistant cell lines carry several point mutations in the ALK kinase domain (G1128S, C1156F, I1171N/T, F1174I, N1178H, E1210K and C1156F/D1203N were the most frequent) that are shown to confer resistance to ASP3026 in the Ba/F3 cell model. All mutants were profiled for cross-resistance against a panel of clinically relevant inhibitors including ceritinib, alectinib, crizotinib, AP26113 and PF-06463922. Finally, a genetically heterogeneous ASP3026-resistant cell line was exposed to second-line treatment simulations with all inhibitors. The population evolved according to relative sensitivity of its mutant subclones to the various drugs. Compound PF-06463922 did not allow the outgrowth of any resistant clone, at non-toxic doses.

  18. Sex differences, developmental changes, response to injury and cAMP regulation of the mRNA levels of steroidogenic acute regulatory protein, cytochrome p450scc, and aromatase in the olivocerebellar system.

    Science.gov (United States)

    Lavaque, Esteban; Mayen, Aurora; Azcoitia, Iñigo; Tena-Sempere, Manuel; Garcia-Segura, Luis M

    2006-02-15

    Compelling evidence has now demonstrated direct biological actions of sex steroids at the cerebellum. Likewise, the expression of key steroidogenic factors, such as the steroidogenic acute regulatory protein (StAR), cytochrome P450 side chain cleavage (P450scc), and aromatase, at this neural site has been reported. Little is known, however, about the regulation of their genes in the cerebellum. Assessment of StAR, P450scc, and aromatase mRNAs in the cerebellum of male and female rats revealed that the expression of these genes is developmentally regulated, with the highest levels at early postnatal ages in both sexes and with significantly higher mRNA levels in postnatal males. Expression of these genes in the female remained unaltered after perinatal androgenization and along the estrous cycle. In contrast, damage of cerebellar afferent neurons of the inferior olivary nucleus evoked a significant increase in StAR, P450scc, and aromatase mRNA levels at this site, as well as a transient elevation in StAR mRNA at the cerebellum. Finally, enhancement of cAMP levels in cultured cerebellar neurons induced a significant increase in StAR and aromatase mRNA levels. In summary, we present herein novel evidence for the developmentally regulated and partially sexually dimorphic pattern of expression of StAR, P450scc, and aromatase genes in the rat cerebellum. These observations, together with the finding that the mRNA levels of these steroidogenic molecules are sensitive to injury and are regulated by intracellular cAMP, strongly suggest that local steroidogenesis is likely to play an important role during development and adaptation to neurodegenerative processes in the olivocerebellar system. PMID:16329132

  19. A haploid genetic screen identifies the G1/S regulatory machinery as a determinant of Wee1 inhibitor sensitivity

    NARCIS (Netherlands)

    Heijink, Anne Margriet; Blomen, Vincent A.; Bisteau, Xavier; Degener, Fabian; Matsushita, Felipe Yu; Kaldis, Philipp; Foijer, Floris; van Vugt, Marcel A. T. M.

    2015-01-01

    The Wee1 cell cycle checkpoint kinase prevents premature mitotic entry by inhibiting cyclin-dependent kinases. Chemical inhibitors of Wee1 are currently being tested clinically as targeted anticancer drugs. Wee1 inhibition is thought to be preferentially cytotoxic in p53-defective cancer cells. Howe

  20. A haploid genetic screen identifies the G(1)/S regulatory machinery as a determinant of Wee1 inhibitor sensitivity

    NARCIS (Netherlands)

    Heijink, Anne Margriet; Blomen, Vincent A.; Bisteau, Xavier; Degener, Fabian; Matsushita, Felipe Yu; Kaldis, Philipp; Foijer, Floris; van Vugt, Marcel A. T. M.

    2015-01-01

    The Wee1 cell cycle checkpoint kinase prevents premature mitotic entry by inhibiting cyclin-dependent kinases. Chemical inhibitors of Wee1 are currently being tested clinically as targeted anticancer drugs. Wee1 inhibition is thought to be preferentially cytotoxic in p53-defective cancer cells. Howe

  1. The cyclin-dependent kinase inhibitor p57Kip2 is epigenetically regulated in carboplatin resistance and results in collateral sensitivity to the CDK inhibitor seliciclib in ovarian cancer

    Science.gov (United States)

    Coley, H M; Safuwan, N A M; Chivers, P; Papacharalbous, E; Giannopoulos, T; Butler-Manuel, S; Madhuri, K; Lovell, D P; Crook, T

    2012-01-01

    Background: Carboplatin remains a first-line agent in the management of epithelial ovarian cancer (EOC). Unfortunately, platinum-resistant disease ultimately occurs in most patients. Using a novel EOC cell line with acquired resistance to carboplatin: PEO1CarbR, genome-wide micro-array profiling identified the cyclin-dependent kinase inhibitor p57Kip2 as specifically downregulated in carboplatin resistance. Presently, we describe confirmation of these preliminary data with a variety of approaches. Methods: Cytotoxicity testing (MTT) and cell cycle blockade assessed drug responsiveness. Methylation specific PCR and pyrosequencing identified sites of promoter methylation in p57Kip2. siRNA to p57Kip2 was used to look at the changes in apoptosis of carboplatin treated EOC cells. EOC tissues (20 cases) were assessed for mRNA levels of p57Kip2. Results: Carboplatin resistance was reversed using 5-aza-cytidine in vitro. Promoter methylation sites and preferential sensitivity to seliciclib were seen in PEO1CarbR cells. Silencing p57Kip2 decreased the apoptotic response to the effects of platinum but produced sensitisation to seliciclib. EOC biopsies indicated an association of high levels of p57Kip2mRNA with complete responses to chemotherapy and improved outcome. Conclusion: We conclude that p57Kip2 is a candidate biomarker of platinum sensitivity/resistance in EOC and such cases may show preferential response to the cyclin-dependent kinase inhibitor seliciclib. PMID:22233925

  2. Sensitivities to various epidermal growth factor receptor-tyrosine kinase inhibitors of uncommon epidermal growth factor receptor mutations L861Q and S768I: What is the optimal epidermal growth factor receptor-tyrosine kinase inhibitor?

    Science.gov (United States)

    Banno, Eri; Togashi, Yosuke; Nakamura, Yu; Chiba, Masato; Kobayashi, Yoshihisa; Hayashi, Hidetoshi; Terashima, Masato; de Velasco, Marco A; Sakai, Kazuko; Fujita, Yoshihiko; Mitsudomi, Tetsuya; Nishio, Kazuto

    2016-08-01

    Most patients with non-small cell lung cancer (NSCLC) harboring common epidermal growth factor receptor (EGFR) mutations, such as deletions in exon 19 or the L858R mutation in exon 21, respond dramatically to EGFR tyrosine kinase inhibitors (EGFR-TKI), and their sensitivities to various EGFR-TKI have been well characterized. Our previous article showed the in vitro sensitivities of EGFR exon 18 mutations to EGFR-TKI, but little information regarding the sensitivities of other uncommon EGFR mutations is available. First, stable transfectant Ba/F3 cell lines harboring EGFR L858R (Ba/F3-L858R), L861Q (Ba/F3-L861Q) or S768I (Ba/F3-S768I) mutations were created and their drug sensitivities to various EGFR-TKI were examined. Both the Ba/F3-L861Q and Ba/F3-S768I cell lines were less sensitive to erlotinib, compared with the Ba/F3-L858R cell line, but their sensitivities to afatinib were similar to that of the Ba/F3-L858R cell line. The Ba/F3-L861Q cell line was similarly sensitive and the Ba/F3-S768I cell line was less sensitive to osimertinib, compared with the Ba/F3-L858R cell line. The results of western blot analyses were consistent with these sensitivities. Next, similar experiments were also performed using the KYSE270 (L861Q) and KYSE 450 (S768I) cell lines, and their results were compatible with those of the transfectant Ba/F3 cell lines. Our findings suggest that NSCLC harboring the EGFR L861Q mutation might be sensitive to afatinib or osimertinib and that NSCLC harboring the EGFR S768I mutation might be sensitive to afatinib. Overall, afatinib might be the optimal EGFR-TKI against these uncommon EGFR mutations. PMID:27240419

  3. P450-aromatase activity and expression in human testicular tissues with severe spermatogenic failure.

    Science.gov (United States)

    Lardone, M C; Castillo, P; Valdevenito, R; Ebensperger, M; Ronco, A M; Pommer, R; Piottante, A; Castro, A

    2010-08-01

    There is evidence that impaired spermatogenesis is associated with an imbalance in the oestradiol/testosterone ratio and with Leydig cell (LC) dysfunction. In testis, P450-aromatase, encoded by CYP19, is responsible for the conversion of testosterone to oestradiol. The aims of this study were to quantify CYP19 mRNA expression, aromatase activity and protein localization, and to measure the oestradiol to testosterone ratio in testicular tissues of men with spermatogenic impairment. Twenty-four men with complete Sertoli cell-only syndrome (SCOS), 14 with focal SCOS, 14 with maturation arrest (MA), 8 with mixed atrophy and 30 controls with normal spermatogenesis were subjected to testicular biopsy. All subjects underwent a physical examination, cytogenetic and serum hormonal studies. Testicular CYP19 mRNA was quantified using real time RT-PCR. Testicular aromatase activity was measured using the (3)H(2)0 assay and protein expression was evaluated using immunohistochemistry. In cases, serum testosterone and oestradiol were normal, but the testosterone/LH ratio was lower compared with controls (p < 0.05). Aromatase was localized in the Leydig, Sertoli and germ cells of all tissues, although stronger intensity was observed in LC. Aromatase mRNA and activity were not altered in cases and correlated positively with LC number (r = 0.516 and r = 0.369; p < 0.008). The intratesticular oestradiol/testosterone ratio was elevated (p = 0.005) in complete SCOS patients compared with controls. In conclusion, testicular aromatase seems to be normal in most subjects with impaired spermatogenesis. However, an altered intratesticular oestradiol/testosterone ratio in some patients with complete SCOS suggests that aromatase is increased, which might contribute to Leydig cell dysfunction.

  4. Insulin-sensitizing and cardiovascular effects of the sodium-hydrogen exchange inhibitor, cariporide, in the JCR: LA-cp rat and db/db mouse.

    Science.gov (United States)

    Russell, J C; Proctor, S D; Kelly, S E; Löhn, M; Busch, A E; Schäfer, S

    2005-12-01

    The effects of the sodium-hydrogen (Na/H) exchange inhibitor cariporide (HOE642), on insulin sensitivity and vascular function were studied in the JCR:LA-cp rat and the db/db mouse. In the insulin-resistant rat, cariporide reduced fasting insulin levels (42%, P JCR:LA-cp insulin-resistant rat, which develops advanced cardiovascular disease and ischemic myocardial lesions. It also improved vascular function in a similar mouse model of insulin resistance. These effects were markedly greater than those of ramipril.

  5. Neomorphic Mutations in PIK3R1 Confer Sensitivity to MAPK Inhibitors due to Activation of ERK and JNK Pathways | Office of Cancer Genomics

    Science.gov (United States)

    In a recent publication in Cancer Cell, CTD2 investigators discovered that a known cancer-associated gain-of-function alteration in phosphoinositide-3-kinase regulatory subunit 1 (PIK3R1) results in novel protein activity that confers sensitivity to mitogen-activated protein kinase (MAPK) inhibitors. The PIK3R1 gene encodes the p85α regulatory subunit of PIK3. Under normal conditions, p85α suppresses PIK3 mediated activation of downstream pathways that promote cell growth and survival.

  6. Histone Deacetylase Inhibitors Sensitize Lung Cancer Cells to Hyperthermia: Involvement of Ku70/SirT-1 in Thermo-Protection

    OpenAIRE

    Hassan, Mohamed K.; Watari, Hidemichi; Salah-eldin, Alaa-eldin; Sultan, Ahmed S.; Mohamed, Zainab; Fujioka, Yoichiro; Ohba, Yusuke; Sakuragi, Noriaki

    2014-01-01

    This study describes the sensitization mechanism to thermal stress by histone deacetylase inhibitors (HDACIs) in lung cancer cells and shows that Ku70, based on its acetylation status, mediates the protection of lung cancer from hyperthermia (42.5°C, 1-6 hrs). Ku70 regulates apoptosis by sequestering pro-apoptotic Bax. However, its role in thermal stress is not fully understood. The findings showed that, pre-treating lung cancer cells with HDACIs, nicotinamide (NM) or Trichostatin A (TsA) or ...

  7. Mechanical deformation of monocytic THP-1 cells : occurrence of two seqential phases with differential sensitivity to metabolic inhibitors

    CERN Document Server

    Bongrand, Pierre; Richelme, Fabienne

    1997-01-01

    Blood leukocytes can exhibit extensive morphological changes during their passage through small capillary vessels. The human monocytic THP-1 cell line was used to explore the metabolic dependence of these shape changes. Cells were aspirated into micropipettes for determination of the rate of protrusion formation. They were then released and the kinetics of morphological recovery was studied. Results were consistent with Evans' model (Blood, 64 : 1028, 1984) of a viscous liquid droplet surrounded by a tensile membrane. The estimated values of cytoplasmic viscosity and membrane tension were 162 Pa.s and 0.0142 millinewton/m respectively. The influence of metabolic inhibitors on cell mechanical behaviour was then studied : results strongly suggested that deformation involved two sequential phases. The cell elongation rate measured during the first 30 seconds following the onset of aspiration was unaffected by azide, an inhibitor of energy production, and it was about doubled by cytochalasin D, a microfilament in...

  8. pH-Sensitive gold nanoclusters: preparation and analytical applications for urea, urease, and urease inhibitor detection.

    Science.gov (United States)

    Deng, Hao-Hua; Wu, Gang-Wei; Zou, Zhi-Qiang; Peng, Hua-Ping; Liu, Ai-Lin; Lin, Xin-Hua; Xia, Xing-Hua; Chen, Wei

    2015-05-01

    Herein, we reported for the first time a facile synthetic process of gold nanoclusters (AuNCs) by using N-acetyl-L-cysteine both as a reducing agent and as a protection ligand. Based on the pH stimuli-responsive properties of the as-prepared AuNCs, we constructed a pH-sensing platform for the detection of urea, urease, and urease inhibitors.

  9. Total levels of tissue inhibitor of metalloproteinases 1 in plasma yield high diagnostic sensitivity and specificity in patients with colon cancer

    DEFF Research Database (Denmark)

    Holten-Andersen, Mads N; Christensen, Ib Jarle; Nielsen, Hans Jørgen;

    2002-01-01

    PURPOSE: The purpose of this study was to measure total levels of tissue inhibitor of metalloproteinases (TIMP-1) by ELISA in plasma from blood donors, patients with inflammatory bowel disease (IBD), and patients with cancer and to correlate the results to patient diagnosis. EXPERIMENTAL DESIGN......: Total TIMP-1 plasma levels were measured by ELISA in blood samples from two different blood donor populations from IBD patients, and preoperative samples from patients with primary colon cancer (CC), rectal cancer (RC), or breast cancer. RESULTS: There were no significant differences in plasma TIMP-1...... levels between healthy donors and IBD or breast cancer patients, whereas patients with CC or RC had significantly elevated TIMP-1 levels. Total TIMP-1 levels identified patients with CC with a sensitivity of 63% at 98% specificity, patients with early CC (Dukes' A+B) with a sensitivity of 56% at 98...

  10. Purification of human placental aromatase cytochrome P-450 with monoclonal antibody and its characterization

    International Nuclear Information System (INIS)

    A simple and efficient method is described for the purification of microsomal aromatase cytochrome P-450 from human placenta. The enzyme was solubilized with Emulgen 913 and sodium cholate and subjected to chromatography on a column of Sepharose 4B couples with a specific monoclonal antibody, followed by hydroxyapatite column chromatography. The specific cytochrome P-450 content of purified aromatase was 13.1 (12-14.8) nmol/mg of protein. Aromatase assays were carried out with reconstituted systems of bovine liver P-450 reductase and dilauroyl-L-α-phosphatidylcholine with [1β-3H,4-14C]androstenedione as substrate. The total recovery of purified aromatase activity was 32.2%, and P-450 recovery was 17.6%. The very high Km value for 16α-hydroxytestosterone aromatization gives a reasonable indication that estriol is not the directly aromatized product in the fetoplacental unit of human pregnancy. The aromatase P-450 was subjected to SDS-polyacrylamide gel electrophoresis in increasing quantities. Silver stain detection techniques indicated a single band having a molecular mass of 55 kDa with greater than 97% purity. The stability analysis showed a half-life of over 4 years on storage at -80C

  11. Inhibition of ceramide glucosylation sensitizes lung cancer cells to ABC294640, a first-in-class small molecule SphK2 inhibitor.

    Science.gov (United States)

    Guan, Shuhong; Liu, Yuan Y; Yan, Tingzan; Zhou, Jun

    2016-08-01

    Sphingosine kinase 2 (SphK2) is proposed as a novel oncotarget for lung cancer. Here, we studied the anti-lung cancer cell activity by ABC294640, a first-in-class SphK2 inhibitor. We showed that ABC294640 suppressed growth of primary and A549 human lung cancer cells, but sparing SphK2-low lung epithelial cells. Inhibition of SphK2 by ABC294640 increased ceramide accumulation, but decreased pro-survival sphingosine-1-phosphate (S1P) content, leading to lung cancer cell apoptosis activation. Significantly, we show that glucosylceramide synthase (GCS) might be a major resistance factor of ABC294640. The GCS inhibitor 1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP) or GCS shRNA/siRNA knockdown facilitated ABC294640-induced ceramide production and lung cancer cell apoptosis. Reversely, forced overexpression of GCS reduced ABC294640's sensitivity, resulting in decreased ceramide accumulation and apoptosis induction in A549 cells. These findings provide further evidences to support that targeting SphK2 by ABC294640 may be a rational treatment option for lung cancer. Ceramide glucosylation inhibition may further sensitize lung cancer cells to ABC294640. PMID:27221045

  12. Mitotic slippage and expression of survivin are linked to differential sensitivity of human cancer cell-lines to the Kinesin-5 inhibitor monastrol.

    Directory of Open Access Journals (Sweden)

    Hila Asraf

    Full Text Available The mitotic Kinesin-5 motor proteins crosslink and slide apart antiparallel spindle microtubules, thus performing essential functions in mitotic spindle dynamics. Specific inhibition of their function by monastrol-like small molecules has been examined in clinical trials as anticancer treatment, with only partial success. Thus, strategies that improve the efficiency of monastrol-like anticancer drugs are required. In the current study, we examined the link between sensitivity to monastrol and occurrence of mitotic slippage in several human cell-lines. We found that the rank of sensitivity to monastrol, from most sensitive to least sensitive, is: AGS > HepG2 > Lovo > Du145 ≥ HT29. We show correlation between the sensitivity of a particular cell-line to monastrol and the tendency of the same cell-line to undergo mitotic slippage. We also found that in the monastrol resistant HT29 cells, prolonged monastrol treatments increase mRNA and protein levels of the chromosomal passenger protein survivin. In contrast, survivin levels are not increased by this treatment in the monastrol-sensitive AGS cells. We further show that over-expression of survivin in the monastrol-sensitive AGS cells reduces mitotic slippage and increases resistance to monastrol. Finally, we show that during short exposure to monastrol, Si RNA silencing of survivin expression reduces cell viability in both AGS and HT29 cells. Our data suggest that the efficiency of anti-cancer treatment with specific kinesin-5 inhibitors may be improved by modulation of expression levels of survivin.

  13. ALK kinase domain mutations in primary anaplastic large cell lymphoma: consequences on NPM-ALK activity and sensitivity to tyrosine kinase inhibitors.

    Directory of Open Access Journals (Sweden)

    Federica Lovisa

    Full Text Available ALK inhibitor crizotinib has shown potent antitumor activity in children with refractory Anaplastic Large Cell Lymphoma (ALCL and the opportunity to include ALK inhibitors in first-line therapies is oncoming. However, recent studies suggest that crizotinib-resistance mutations may emerge in ALCL patients. In the present study, we analyzed ALK kinase domain mutational status of 36 paediatric ALCL patients at diagnosis to identify point mutations and gene aberrations that could impact on NPM-ALK gene expression, activity and sensitivity to small-molecule inhibitors. Amplicon ultra-deep sequencing of ALK kinase domain detected 2 single point mutations, R335Q and R291Q, in 2 cases, 2 common deletions of exon 23 and 25 in all the patients, and 7 splicing-related INDELs in a variable number of them. The functional impact of missense mutations and INDELs was evaluated. Point mutations were shown to affect protein kinase activity, signalling output and drug sensitivity. INDELs, instead, generated kinase-dead variants with dominant negative effect on NPM-ALK kinase, in virtue of their capacity of forming non-functional heterocomplexes. Consistently, when co-expressed, INDELs increased crizotinib inhibitory activity on NPM-ALK signal processing, as demonstrated by the significant reduction of STAT3 phosphorylation. Functional changes in ALK kinase activity induced by both point mutations and structural rearrangements were resolved by molecular modelling and dynamic simulation analysis, providing novel insights into ALK kinase domain folding and regulation. Therefore, these data suggest that NPM-ALK pre-therapeutic mutations may be found at low frequency in ALCL patients. These mutations occur randomly within the ALK kinase domain and affect protein activity, while preserving responsiveness to crizotinib.

  14. ALK kinase domain mutations in primary anaplastic large cell lymphoma: consequences on NPM-ALK activity and sensitivity to tyrosine kinase inhibitors.

    Science.gov (United States)

    Lovisa, Federica; Cozza, Giorgio; Cristiani, Andrea; Cuzzolin, Alberto; Albiero, Alessandro; Mussolin, Lara; Pillon, Marta; Moro, Stefano; Basso, Giuseppe; Rosolen, Angelo; Bonvini, Paolo

    2015-01-01

    ALK inhibitor crizotinib has shown potent antitumor activity in children with refractory Anaplastic Large Cell Lymphoma (ALCL) and the opportunity to include ALK inhibitors in first-line therapies is oncoming. However, recent studies suggest that crizotinib-resistance mutations may emerge in ALCL patients. In the present study, we analyzed ALK kinase domain mutational status of 36 paediatric ALCL patients at diagnosis to identify point mutations and gene aberrations that could impact on NPM-ALK gene expression, activity and sensitivity to small-molecule inhibitors. Amplicon ultra-deep sequencing of ALK kinase domain detected 2 single point mutations, R335Q and R291Q, in 2 cases, 2 common deletions of exon 23 and 25 in all the patients, and 7 splicing-related INDELs in a variable number of them. The functional impact of missense mutations and INDELs was evaluated. Point mutations were shown to affect protein kinase activity, signalling output and drug sensitivity. INDELs, instead, generated kinase-dead variants with dominant negative effect on NPM-ALK kinase, in virtue of their capacity of forming non-functional heterocomplexes. Consistently, when co-expressed, INDELs increased crizotinib inhibitory activity on NPM-ALK signal processing, as demonstrated by the significant reduction of STAT3 phosphorylation. Functional changes in ALK kinase activity induced by both point mutations and structural rearrangements were resolved by molecular modelling and dynamic simulation analysis, providing novel insights into ALK kinase domain folding and regulation. Therefore, these data suggest that NPM-ALK pre-therapeutic mutations may be found at low frequency in ALCL patients. These mutations occur randomly within the ALK kinase domain and affect protein activity, while preserving responsiveness to crizotinib.

  15. Nontoxic concentration of DNA-PK inhibitor NU7441 radio-sensitizes lung tumor cells with little effect on double strand break repair.

    Science.gov (United States)

    Sunada, Shigeaki; Kanai, Hideki; Lee, Younghyun; Yasuda, Takeshi; Hirakawa, Hirokazu; Liu, Cuihua; Fujimori, Akira; Uesaka, Mitsuru; Okayasu, Ryuichi

    2016-09-01

    High-linear energy transfer (LET) heavy ions have been increasingly employed as a useful alternative to conventional photon radiotherapy. As recent studies suggested that high LET radiation mainly affects the nonhomologous end-joining (NHEJ) pathway of DNA double strand break (DSB) repair, we further investigated this concept by evaluating the combined effect of an NHEJ inhibitor (NU7441) at a non-toxic concentration and carbon ions. NU7441-treated non-small cell lung cancer (NSCLC) A549 and H1299 cells were irradiated with X-rays and carbon ions (290 MeV/n, 50 keV/μm). Cell survival was measured by clonogenic assay. DNA DSB repair, cell cycle distribution, DNA fragmentation and cellular senescence induction were studied using a flow cytometer. Senescence-associated protein p21 was detected by western blotting. In the present study, 0.3 μM of NU7441, nontoxic to both normal and tumor cells, caused a significant radio-sensitization in tumor cells exposed to X-rays and carbon ions. This concentration did not seem to cause inhibition of DNA DSB repair but induced a significant G2/M arrest, which was particularly emphasized in p53-null H1299 cells treated with NU7441 and carbon ions. In addition, the combined treatment induced more DNA fragmentation and a higher degree of senescence in H1299 cells than in A549 cells, indicating that DNA-PK inhibitor contributes to various modes of cell death in a p53-dependent manner. In summary, NSCLC cells irradiated with carbon ions were radio-sensitized by a low concentration of DNA-PK inhibitor NU7441 through a strong G2/M cell cycle arrest. Our findings may contribute to further effective radiotherapy using heavy ions. PMID:27341700

  16. Targeting TORC1/2 enhances sensitivity to EGFR inhibitors in head and neck cancer preclinical models.

    Science.gov (United States)

    Cassell, Andre; Freilino, Maria L; Lee, Jessica; Barr, Sharon; Wang, Lin; Panahandeh, Mary C; Thomas, Sufi M; Grandis, Jennifer R

    2012-11-01

    Head and neck squamous cell carcinoma (HNSCC) is characterized by overexpression of the epidermal growth factor receptor (EGFR) where treatments targeting EGFR have met with limited clinical success. Elucidation of the key downstream-pathways that remain activated in the setting of EGFR blockade may reveal new therapeutic targets. The present study was undertaken to test the hypothesis that inhibition of the mammalian target of rapamycin (mTOR) complex would enhance the effects of EGFR blockade in HNSCC preclinical models. Treatment of HNSCC cell lines with the newly developed TORC1/TORC2 inhibitor OSI-027/ASP4876 resulted in dose-dependent inhibition of proliferation with abrogation of phosphorylation of known downstream targets including phospho-AKT (Ser473), phospho-4E-BP1, phospho-p70s6K, and phospho-PRAS40. Furthermore, combined treatment with OSI-027 and erlotinib resulted in enhanced biochemical effects and synergistic growth inhibition in vitro. Treatment of mice bearing HNSCC xenografts with a combination of the Food and Drug Administration (FDA)-approved EGFR inhibitor cetuximab and OSI-027 demonstrated a significant reduction of tumor volumes compared with either treatment alone. These findings suggest that TORC1/TORC2 inhibition in conjunction with EGFR blockade represents a plausible therapeutic strategy for HNSCC. PMID:23226094

  17. Targeting TORC1/2 Enhances Sensitivity to EGFR Inhibitors in Head and Neck Cancer Preclinical Models

    Directory of Open Access Journals (Sweden)

    Andre Cassell

    2012-11-01

    Full Text Available Head and neck squamous cell carcinoma (HNSCC is characterized by overexpression of the epidermal growth factor receptor (EGFR where treatments targeting EGFR have met with limited clinical success. Elucidation of the key downstream-pathways that remain activated in the setting of EGFR blockade may reveal new therapeutic targets. The present study was undertaken to test the hypothesis that inhibition of the mammalian target of rapamycin (mTOR complex would enhance the effects of EGFR blockade in HNSCC preclinical models. Treatment of HNSCC cell lines with the newly developed TORC1/TORC2 inhibitor OSI-027/ASP4876 resulted in dose-dependent inhibition of proliferation with abrogation of phosphorylation of known downstream targets including phospho-AKT (Ser473, phospho-4E-BP1, phospho-p70s6K, and phospho-PRAS40. Furthermore, combined treatment with OSI-027 and erlotinib resulted in enhanced biochemical effects and synergistic growth inhibition in vitro. Treatment of mice bearing HNSCC xenografts with a combination of the Food and Drug Administration (FDA-approved EGFR inhibitor cetuximab and OSI-027 demonstrated a significant reduction of tumor volumes compared with either treatment alone. These findings suggest that TORC1/TORC2 inhibition in conjunction with EGFR blockade represents a plausible therapeutic strategy for HNSCC.

  18. Transgenic Chickens Overexpressing Aromatase Have High Estrogen Levels but Maintain a Predominantly Male Phenotype.

    Science.gov (United States)

    Lambeth, Luke S; Morris, Kirsten R; Wise, Terry G; Cummins, David M; O'Neil, Terri E; Cao, Yu; Sinclair, Andrew H; Doran, Timothy J; Smith, Craig A

    2016-01-01

    Estrogens play a key role in sexual differentiation of both the gonads and external traits in birds. The production of estrogen occurs via a well-characterized steroidogenic pathway, which is a multistep process involving several enzymes, including cytochrome P450 aromatase. In chicken embryos, the aromatase gene (CYP19A1) is expressed female-specifically from the time of gonadal sex differentiation. Ectopic overexpression of aromatase in male chicken embryos induces gonadal sex reversal, and male embryos treated with estradiol become feminized; however, this is not permanent. To test whether a continuous supply of estrogen in adult chickens could induce stable male to female sex reversal, 2 transgenic male chickens overexpressing aromatase were generated using the Tol2/transposase system. These birds had robust ectopic aromatase expression, which resulted in the production of high serum levels of estradiol. Transgenic males had female-like wattle and comb growth and feathering, but they retained male weights, displayed leg spurs, and developed testes. Despite the small sample size, this data strongly suggests that high levels of circulating estrogen are insufficient to maintain a female gonadal phenotype in adult birds. Previous observations of gynandromorph birds and embryos with mixed sex chimeric gonads have highlighted the role of cell autonomous sex identity in chickens. This might imply that in the study described here, direct genetic effects of the male chromosomes largely prevailed over the hormonal profile of the aromatase transgenic birds. This data therefore support the emerging view of at least partial cell autonomous sex development in birds. However, a larger study will confirm this intriguing observation. PMID:26556534

  19. Sex differences in brain aromatase activity: genomic and non-genomic controls

    Directory of Open Access Journals (Sweden)

    Jacques eBalthazart

    2011-09-01

    Full Text Available Aromatization of testosterone into estradiol in the preoptic area plays a critical role in the activation of male copulation in quail and in many other vertebrate species. Aromatase expression in quail and in other birds is higher than in rodents and other mammals, which has facilitated the study of the controls and functions of this enzyme. Over relatively long time periods (days to months, brain aromatase activity and transcription are markedly (4-6 fold increased by genomic actions of sex steroids. Initial work indicated that the preoptic aromatase activity is higher in males than in females and it was hypothesized that this differential production of estrogen could be a critical factor responsible for the lack of behavioral activation in females. Subsequent studies revealed, however, that this enzymatic sex difference might contribute but is not sufficient to explain the sex difference in behavior. Studies of aromatase activity, immunoreactivity and mRNA concentrations revealed that sex differences observed when measuring enzymatic activity are not necessarily observed when one measures mRNA concentrations. Discrepancies potentially reflect post-translational controls of the enzymatic activity. Aromatase activity in quail brain homogenates is rapidly inhibited by phosphorylation processes. Similar rapid inhibitions occur in hypothalamic explants maintained in vitro and exposed to agents affecting intracellular calcium concentrations or to glutamate agonists. Rapid changes in aromatase activity have also been observed in vivo following sexual interactions or exposure to short-term restraint stress and these rapid changes in estrogen production modulate expression of male sexual behaviors. These data suggest that brain estrogens display most if not all characteristics of neuromodulators if not neurotransmitters. Many questions remain however concerning the mechanisms controlling these rapid changes in estrogen production and their behavioral

  20. Transgenic Chickens Overexpressing Aromatase Have High Estrogen Levels but Maintain a Predominantly Male Phenotype.

    Science.gov (United States)

    Lambeth, Luke S; Morris, Kirsten R; Wise, Terry G; Cummins, David M; O'Neil, Terri E; Cao, Yu; Sinclair, Andrew H; Doran, Timothy J; Smith, Craig A

    2016-01-01

    Estrogens play a key role in sexual differentiation of both the gonads and external traits in birds. The production of estrogen occurs via a well-characterized steroidogenic pathway, which is a multistep process involving several enzymes, including cytochrome P450 aromatase. In chicken embryos, the aromatase gene (CYP19A1) is expressed female-specifically from the time of gonadal sex differentiation. Ectopic overexpression of aromatase in male chicken embryos induces gonadal sex reversal, and male embryos treated with estradiol become feminized; however, this is not permanent. To test whether a continuous supply of estrogen in adult chickens could induce stable male to female sex reversal, 2 transgenic male chickens overexpressing aromatase were generated using the Tol2/transposase system. These birds had robust ectopic aromatase expression, which resulted in the production of high serum levels of estradiol. Transgenic males had female-like wattle and comb growth and feathering, but they retained male weights, displayed leg spurs, and developed testes. Despite the small sample size, this data strongly suggests that high levels of circulating estrogen are insufficient to maintain a female gonadal phenotype in adult birds. Previous observations of gynandromorph birds and embryos with mixed sex chimeric gonads have highlighted the role of cell autonomous sex identity in chickens. This might imply that in the study described here, direct genetic effects of the male chromosomes largely prevailed over the hormonal profile of the aromatase transgenic birds. This data therefore support the emerging view of at least partial cell autonomous sex development in birds. However, a larger study will confirm this intriguing observation.

  1. Screening of selected pesticides for inhibition of CYP19 aromatase activity in vitro

    DEFF Research Database (Denmark)

    Vinggaard, A.M.; Hnida, C.; Breinholt, V.;

    2000-01-01

    range of hormone-mimicking effects. Twenty-two pesticides were tested for their ability to affect CYP19 aromatase activity in human placental microsomes using the classical [H-3](2)O method. Prochloraz, imazalil, propioconazole, fenarimol, triadimenol, triadimefon tall fungicides), and dicofol tan...... acaricide) gave rise to a statistically significant inhibition of aromatase activity. The IC(50)s of prochloraz, imazalil, propioconazole fenarimol, triadimenol, and triadimefon were calculated from dose-response curves to be 0.04, 0.34, 6.5, 10, 21 and 32 mu M, respectively, The IC50 Of dicofol was greater...

  2. Xanthones from the Botanical Dietary Supplement Mangosteen (Garcinia mangostana) with Aromatase Inhibitory Activity

    OpenAIRE

    Balunas, Marcy J.; Su, Bin; Brueggemeier, Robert W.; Kinghorn, A. Douglas

    2008-01-01

    Twelve xanthone constituents of the botanical dietary supplement, mangosteen (the pericarp of Garcinia mangostina) were screened using a non-cellular, enzyme-based microsomal aromatase inhibition assay. Of these compounds, garcinone D (3), garcinone E (5)α-mangostin (8), and γ-mangostin (9) exhibited dose-dependent inhibitory activity. In a follow-up cell-based assay using SK-BR-3 breast cancer cells that express high levels of aromatase, the most potent of these four xanthones was γ-mangosti...

  3. DNA methylation of the gonadal aromatase (cyp19a promoter is involved in temperature-dependent sex ratio shifts in the European sea bass.

    Directory of Open Access Journals (Sweden)

    Laia Navarro-Martín

    2011-12-01

    Full Text Available Sex ratio shifts in response to temperature are common in fish and reptiles. However, the mechanism linking temperature during early development and sex ratios has remained elusive. We show in the European sea bass (sb, a fish in which temperature effects on sex ratios are maximal before the gonads form, that juvenile males have double the DNA methylation levels of females in the promoter of gonadal aromatase (cyp19a, the enzyme that converts androgens into estrogens. Exposure to high temperature increased the cyp19a promoter methylation levels of females, indicating that induced-masculinization involves DNA methylation-mediated control of aromatase gene expression, with an observed inverse relationship between methylation levels and expression. Although different CpGs within the sb cyp19a promoter exhibited different sensitivity to temperature, we show that the increased methylation of the sb cyp19a promoter, which occurs in the gonads but not in the brain, is not a generalized effect of temperature. Importantly, these effects were also observed in sexually undifferentiated fish and were not altered by estrogen treatment. Thus, methylation of the sb cyp19a promoter is the cause of the lower expression of cyp19a in temperature-masculinized fish. In vitro, induced methylation of the sb cyp19a promoter suppressed the ability of SF-1 and Foxl2 to stimulate transcription. Finally, a CpG differentially methylated by temperature and adjacent to a Sox transcription factor binding site is conserved across species. Thus, DNA methylation of the aromatase promoter may be an essential component of the long-sought-after mechanism connecting environmental temperature and sex ratios in vertebrate species with temperature-dependent sex determination.

  4. DNA Methylation of the Gonadal Aromatase (cyp19a) Promoter Is Involved in Temperature-Dependent Sex Ratio Shifts in the European Sea Bass

    Science.gov (United States)

    Navarro-Martín, Laia; Viñas, Jordi; Ribas, Laia; Díaz, Noelia; Gutiérrez, Arantxa; Di Croce, Luciano; Piferrer, Francesc

    2011-01-01

    Sex ratio shifts in response to temperature are common in fish and reptiles. However, the mechanism linking temperature during early development and sex ratios has remained elusive. We show in the European sea bass (sb), a fish in which temperature effects on sex ratios are maximal before the gonads form, that juvenile males have double the DNA methylation levels of females in the promoter of gonadal aromatase (cyp19a), the enzyme that converts androgens into estrogens. Exposure to high temperature increased the cyp19a promoter methylation levels of females, indicating that induced-masculinization involves DNA methylation-mediated control of aromatase gene expression, with an observed inverse relationship between methylation levels and expression. Although different CpGs within the sb cyp19a promoter exhibited different sensitivity to temperature, we show that the increased methylation of the sb cyp19a promoter, which occurs in the gonads but not in the brain, is not a generalized effect of temperature. Importantly, these effects were also observed in sexually undifferentiated fish and were not altered by estrogen treatment. Thus, methylation of the sb cyp19a promoter is the cause of the lower expression of cyp19a in temperature-masculinized fish. In vitro, induced methylation of the sb cyp19a promoter suppressed the ability of SF-1 and Foxl2 to stimulate transcription. Finally, a CpG differentially methylated by temperature and adjacent to a Sox transcription factor binding site is conserved across species. Thus, DNA methylation of the aromatase promoter may be an essential component of the long-sought-after mechanism connecting environmental temperature and sex ratios in vertebrate species with temperature-dependent sex determination. PMID:22242011

  5. The PARP inhibitor PJ-34 sensitizes cells to UVA-induced phototoxicity by a PARP independent mechanism.

    Science.gov (United States)

    Lakatos, Petra; Hegedűs, Csaba; Salazar Ayestarán, Nerea; Juarranz, Ángeles; Kövér, Katalin E; Szabó, Éva; Virág, László

    2016-08-01

    A combination of a photosensitizer with light of matching wavelength is a common treatment modality in various diseases including psoriasis, atopic dermatitis and tumors. DNA damage and production of reactive oxygen intermediates may impact pathological cellular functions and viability. Here we set out to investigate the role of the nuclear DNA nick sensor enzyme poly(ADP-ribose) polymerase 1 in photochemical treatment (PCT)-induced tumor cell killing. We found that silencing PARP-1 or inhibition of its enzymatic activity with Veliparib had no significant effect on the viability of A431 cells exposed to 8-methoxypsoralen (8-MOP) and UVA (2.5J/cm(2)) indicating that PARP-1 is not likely to be a key player in either cell survival or cell death of PCT-exposed cells. Interestingly, however, another commonly used PARP inhibitor PJ-34 proved to be a photosensitizer with potency equal to 8-MOP. Irradiation of PJ-34 with UVA caused changes both in the UV absorption and in the 1H NMR spectra of the compound with the latter suggesting UVA-induced formation of tautomeric forms of the compound. Characterization of the photosensitizing effect revealed that PJ-34+UVA triggers overproduction of reactive oxygen species, induces DNA damage, activation of caspase 3 and caspase 8 and internucleosomal DNA fragmentation. Cell death in this model could not be prevented by antioxidants (ascorbic acid, trolox, glutathione, gallotannin or cell permeable superoxide dismutase or catalase) but could be suppressed by inhibitors of caspase-3 and -8. In conclusion, PJ-34 is a photosensitizer and PJ-34+UVA causes DNA damage and caspase-mediated cell death independently of PARP-1 inhibition. PMID:27427773

  6. Functional characterization, localization, and inhibitor sensitivity of the TPR-FGFR1 fusion in 8p11 myeloproliferative syndrome.

    Science.gov (United States)

    Malli, Theodora; Buxhofer-Ausch, Veronika; Rammer, Melanie; Erdel, Martin; Kranewitter, Wolfgang; Rumpold, Holger; Marschon, Renate; Deutschbauer, Sabine; Simonitsch-Klupp, Ingrid; Valent, Peter; Muellner-Ammer, Kirsten; Sebesta, Christian; Birkner, Thomas; Webersinke, Gerald

    2016-01-01

    Myeloid and lymphoid neoplasms with fibroblast growth factor receptor 1 (FGFR1) abnormalities, also known as 8p11 myeloproliferative syndrome (EMS), represent rare and aggressive disorders, associated with chromosomal aberrations that lead to the fusion of FGFR1 to different partner genes. We report on a third patient with a fusion of the translocated promoter region (TPR) gene, a component of the nuclear pore complex, to FGFR1 due to a novel ins(1;8)(q25;p11p23). The fact that this fusion is a rare but recurrent event in EMS prompted us to examine the localization and transforming potential of the chimeric protein. TPR-FGFR1 localizes in the cytoplasm, although the nuclear pore localization signal of TPR is retained in the fusion protein. Furthermore, TPR-FGFR1 enables cytokine-independent survival, proliferation, and granulocytic differentiation of the interleukin-3 dependent myeloid progenitor cell line 32Dcl3, reflecting the chronic phase of EMS characterized by myeloid hyperplasia. 32Dcl3 cells transformed with the TPR-FGFR1 fusion and treated with increasing concentrations of the tyrosine kinase inhibitors ponatinib (AP24534) and infigratinib (NVP-BGJ398) displayed reduced survival and proliferation with IC50 values of 49.8 and 7.7 nM, respectively. Ponatinib, a multitargeted tyrosine kinase inhibitor, is already shown to be effective against several FGFR1-fusion kinases. Infigratinib, tested only against FGFR1OP2-FGFR1 to date, is also efficient against TPR-FGFR1. Taking its high specificity for FGFRs into account, infigratinib could be beneficial for EMS patients and should be further investigated for the treatment of myeloproliferative neoplasms with FGFR1 abnormalities.

  7. Increased sensitivity of an adriamycin-resistant human small cell lung carcinoma cell line to mitochondrial inhibitors

    NARCIS (Netherlands)

    de Jong, Steven; Holtrop, M; de Vries, H; de Vries, Liesbeth; Mulder, N H

    1992-01-01

    The energy metabolism of an atypical multidrug resistant human small cell lung carcinoma cell line (GLC4/ADR) was studied. The glycolytic rate was 30% reduced and the glucose-6-phosphate dehydrogenase activity 2-fold increased in GLC4/ADR compared to the parental sensitive line (GLC4). Although mito

  8. Comparative study on individual aromatase inhibitors on cardiovascular safety profile: misleading analysis and doubtful methodology

    OpenAIRE

    Guo WQ; Li L

    2015-01-01

    Wenqin Guo, Lang Li Department of Cardiology, The First Affiliated Hospital of Guangxi Medical University, Nanning, People’s Republic of ChinaZhao et al have presented the result of the relative cardiovascular safety profile in using anastrozole, letrozole, and exemestane to treat the postmenopausal estrogen receptor-positive breast cancer, in which fatal or nonfatal myocardial infarction is the outcome measure and ten randomized controlled trials are used as the data sources.1 We cong...

  9. Comparative study on individual aromatase inhibitors on cardiovascular safety profile: misleading analysis and doubtful methodology

    OpenAIRE

    Guo, Wenqin; Li, Lang

    2015-01-01

    Wenqin Guo, Lang Li Department of Cardiology, The First Affiliated Hospital of Guangxi Medical University, Nanning, People’s Republic of ChinaZhao et al have presented the result of the relative cardiovascular safety profile in using anastrozole, letrozole, and exemestane to treat the postmenopausal estrogen receptor-positive breast cancer, in which fatal or nonfatal myocardial infarction is the outcome measure and ten randomized controlled trials are used as the data sources.1 We ...

  10. Comparative study on individual aromatase inhibitors on cardiovascular safety profile: misleading analysis and doubtful methodology

    Directory of Open Access Journals (Sweden)

    Guo WQ

    2015-11-01

    Full Text Available Wenqin Guo, Lang Li Department of Cardiology, The First Affiliated Hospital of Guangxi Medical University, Nanning, People’s Republic of ChinaZhao et al have presented the result of the relative cardiovascular safety profile in using anastrozole, letrozole, and exemestane to treat the postmenopausal estrogen receptor-positive breast cancer, in which fatal or nonfatal myocardial infarction is the outcome measure and ten randomized controlled trials are used as the data sources.1 We congratulate and applaud their important work, but there are some issues of concern.  View original article by Zhao et al 

  11. A Case of Erythrocytosis in a Patient Treated with an Aromatase Inhibitor for Breast Cancer

    OpenAIRE

    Abhinav Iyengar; Dawn Sheppard

    2013-01-01

    A previously healthy 79-year-old female was referred to hematology for further evaluation of erythrocytosis. Two years earlier she had been diagnosed with ER/PR-positive ductal carcinoma of the breast and was receiving hormonal therapy with exemestane. No secondary cause of erythrocytosis was identified. Serum erythropoietin (EPO) level was normal, and molecular testing for the JAK2 V617F and exon 12 mutations was negative. A bone marrow biopsy showed a mild increase in erythropoiesis, and no...

  12. Investigation of adaptive responses in fathead minnows (Pimephales promelas) exposed to the model aromatase inhibitor fadrozole

    Science.gov (United States)

    The vertebrate hypothalamic-pituitary-gonadal (HPG) axis is a highly dynamic system, which, through various feedback mechanisms, strives to maintain physiological conditions conducive to reproduction even in potentially stressful situations. The development of useful predictive m...

  13. Crystal Structures of Human Choline Kinase Isoforms in Complex with Hemicholinium-3 Single Amino Acid near the Active Site Influences Inhibitor Sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Bum Soo; Allali-Hassani, Abdellah; Tempel, Wolfram; Finerty, Jr., Patrick J.; MacKenzie, Farrell; Dimov, Svetoslav; Vedadi, Masoud; Park, Hee-Won (Toronto)

    2010-07-06

    Human choline kinase (ChoK) catalyzes the first reaction in phosphatidylcholine biosynthesis and exists as ChoK{alpha} ({alpha}1 and {alpha}2) and ChoK{beta} isoforms. Recent studies suggest that ChoK is implicated in tumorigenesis and emerging as an attractive target for anticancer chemotherapy. To extend our understanding of the molecular mechanism of ChoK inhibition, we have determined the high resolution x-ray structures of the ChoK{alpha}1 and ChoK{beta} isoforms in complex with hemicholinium-3 (HC-3), a known inhibitor of ChoK. In both structures, HC-3 bound at the conserved hydrophobic groove on the C-terminal lobe. One of the HC-3 oxazinium rings complexed with ChoK{alpha}1 occupied the choline-binding pocket, providing a structural explanation for its inhibitory action. Interestingly, the HC-3 molecule co-crystallized with ChoK{beta} was phosphorylated in the choline binding site. This phosphorylation, albeit occurring at a very slow rate, was confirmed experimentally by mass spectroscopy and radioactive assays. Detailed kinetic studies revealed that HC-3 is a much more potent inhibitor for ChoK{alpha} isoforms ({alpha}1 and {alpha}2) compared with ChoK{beta}. Mutational studies based on the structures of both inhibitor-bound ChoK complexes demonstrated that Leu-401 of ChoK{alpha}2 (equivalent to Leu-419 of ChoK{alpha}1), or the corresponding residue Phe-352 of ChoK{beta}, which is one of the hydrophobic residues neighboring the active site, influences the plasticity of the HC-3-binding groove, thereby playing a key role in HC-3 sensitivity and phosphorylation.

  14. In situ aromatase expression in primary tumor is associated with estrogen receptor expression but is not predictive of response to endocrine therapy in advanced breast cancer

    DEFF Research Database (Denmark)

    Lykkesfeldt, Anne E; Henriksen, Katrine L; Rasmussen, Birgitte B;

    2009-01-01

    whether in situ carcinoma cell aromatization is the primary source of estrogen production for tumor growth and whether the aromatase expression is predictive of response to endocrine therapy. Due to methodological difficulties in the determination of the aromatase protein, COX-2, an enzyme involved...... of advanced breast cancer. Semi-quantitative immunohistochemical (IHC) analysis was performed for ER, PR, COX-2 and aromatase using Tissue Microarrays (TMAs). Aromatase was also analyzed using whole sections (WS). Kappa analysis was applied to compare association of protein expression levels. Univariate...... TMAs. Expression of COX-2 and aromatase did not predict response to endocrine therapy. Aromatase in combination with high PR expression may select letrozole treated patients with a longer TTP. CONCLUSION: TMAs are not suitable for IHC analysis of in situ aromatase expression and we did not find COX-2...

  15. Diffusion-weighted MR imaging of metastatic abdominal and pelvic tumours is sensitive to early changes induced by a VEGF inhibitor using alternative diffusion attenuation models

    International Nuclear Information System (INIS)

    To assess the utility of diffusion weighted imaging for monitoring early treatment effects associated with a VEGF inhibitor. Twenty-nine patients with metastatic abdominal and pelvic tumours were recruited and imaged with DW-MRI: twice at baseline, and after 7 and 28 days of treatment with cediranib. Tumour measures were derived using mono-exponential, bi-exponential and stretched-exponential models, and parameter repeatability and treatment effects seen after 7 and 28 days were assessed. Correlations with volume changes and DCE-MRI metrics were also assessed. Diffusion coefficient repeatabilities from all models were < 6 %; f and D* (bi-exponential) were 22 % and 44 %; α (stretched-exponential) was 4.2 %. Significant increases in the diffusion coefficients from all models were observed at day 28 but not day 7. Significant decreases in D* and f.D* were observed at day 7 and in f at day 28; significant increases in α were observed at both time-points. Weak correlations between DW-MRI changes and volume changes and DCE-MRI changes were observed. DW-MRI is sensitive to early and late treatment changes caused by a VEGF inhibitor using non-mono-exponential models. Evidence of over-fitting using the bi-exponential model suggests that the stretched-exponential model is best suited to monitor such changes. (orig.)

  16. Diffusion-weighted MR imaging of metastatic abdominal and pelvic tumours is sensitive to early changes induced by a VEGF inhibitor using alternative diffusion attenuation models

    Energy Technology Data Exchange (ETDEWEB)

    Orton, Matthew R. [Institute of Cancer Research and Royal Marsden NHS Foundation Trust, CRUK and EPSRC Cancer Imaging Centre, Sutton, Surrey (United Kingdom); Institute of Cancer Research, Sutton, Surrey (United Kingdom); Messiou, Christina; DeSouza, Nandita [Institute of Cancer Research and Royal Marsden NHS Foundation Trust, CRUK and EPSRC Cancer Imaging Centre, Sutton, Surrey (United Kingdom); Royal Marsden NHS Foundation Trust, Department of Radiology, Sutton, Surrey (United Kingdom); Collins, David; Leach, Martin O. [Institute of Cancer Research and Royal Marsden NHS Foundation Trust, CRUK and EPSRC Cancer Imaging Centre, Sutton, Surrey (United Kingdom); Morgan, Veronica A. [Royal Marsden NHS Foundation Trust, Department of Radiology, Sutton, Surrey (United Kingdom); Tessier, Jean; Young, Helen [Early Clinical Development, AstraZeneca, Macclesfield (United Kingdom)

    2016-05-15

    To assess the utility of diffusion weighted imaging for monitoring early treatment effects associated with a VEGF inhibitor. Twenty-nine patients with metastatic abdominal and pelvic tumours were recruited and imaged with DW-MRI: twice at baseline, and after 7 and 28 days of treatment with cediranib. Tumour measures were derived using mono-exponential, bi-exponential and stretched-exponential models, and parameter repeatability and treatment effects seen after 7 and 28 days were assessed. Correlations with volume changes and DCE-MRI metrics were also assessed. Diffusion coefficient repeatabilities from all models were < 6 %; f and D* (bi-exponential) were 22 % and 44 %; α (stretched-exponential) was 4.2 %. Significant increases in the diffusion coefficients from all models were observed at day 28 but not day 7. Significant decreases in D* and f.D* were observed at day 7 and in f at day 28; significant increases in α were observed at both time-points. Weak correlations between DW-MRI changes and volume changes and DCE-MRI changes were observed. DW-MRI is sensitive to early and late treatment changes caused by a VEGF inhibitor using non-mono-exponential models. Evidence of over-fitting using the bi-exponential model suggests that the stretched-exponential model is best suited to monitor such changes. (orig.)

  17. Development of Nano-Liposomal Formulations of Epidermal Growth Factor Receptor Inhibitors and their Pharmacological Interactions on Drug-Sensitive and Drug-Resistant Cancer Cell Lines

    Science.gov (United States)

    Trummer, Brian J.

    , due to leaky tumor vasculature and the resulting Enhanced Permeability and Retention (EPR) phenomenon. In Chapter 2 we report that both gefitinib and the structurally similar EGFR inhibitor erlotinib display environment-dependent fluorescence properties. Peak excitation was 345 nm, and the emission peak ranged from 365 to 476 nm, depending upon the polarity of the environment and physical state of the drug. The fluorescence was negligible in aqueous solution, but intense in organic solvents or membrane bilayers. The environment-sensitive fluorescence properties of these drugs enabled rapid evaluation of numerous parameters affecting liposomal drug incorporation and performance. Up to 4-6 mol% of gefitinib could be incorporated in the liposome bilayer, based upon hydrophobic interactions with membrane bilayers. In contrast, 40-60 mol% could be loaded into the aqueous core of pre-formed liposomes at high efficiency, using a remote loading procedure. A stable formulation consisting of distearoylphosphatidylcholine: polyethylene glycol-distereoylphosphatidylethanolamine: cholesterol (DSPC:PEGDSPE:Chol, 9:1:5 mol:mol:mol) and containing drug at 50-60 mol% gefitinib (L-GEF) showed minimal leakage in serum-containing medium over 24 h at 37°C, which should be sufficient to improve biodistribution in vivo. Chapter 3 investigated the pharmacological activity of liposome-encapsulated gefitinib, alone and in combination with several prevalent anticancer agents. Experiments with MCF7 breast cancer cell lines demonstrated that liposome encapsulated gefitinib formulation (L-GEF) had a 2-fold higher IC50 (concentration of drug resulting in half-maximal growth inhibition) than free gefitinib. Lower in vitro potency would be consistent with delayed drug release from the carrier. Therapeutic effects were investigated in combination with the cytotoxic agents paclitaxel and doxorubicin. The drug-resistant MCF7R cell line was 23-fold more resistant to paclitaxel than the parental, drug-sensitive

  18. BRCA1-deficient breast cancer cell lines are resistant to MEK inhibitors and show distinct sensitivities to 6-thioguanine.

    Science.gov (United States)

    Gu, Yuexi; Helenius, Mikko; Väänänen, Kristiina; Bulanova, Daria; Saarela, Jani; Sokolenko, Anna; Martens, John; Imyanitov, Evgeny; Kuznetsov, Sergey

    2016-01-01

    Germ-line or somatic inactivation of BRCA1 is a defining feature for a portion of human breast cancers. Here we evaluated the anti-proliferative activity of 198 FDA-approved and experimental drugs against four BRCA1-mutant (HCC1937, MDA-MB-436, SUM1315MO2, and SUM149PT) and four BRCA1-wild-type (MDA-MB-231, SUM229PE, MCF10A, and MCF7) breast cancer cell lines. We found that all BRCA1-mutant cell lines were insensitive to inhibitors of mitogen-activated protein kinase kinase 1 and 2 (MEK1/2) Selumetinib and Pimasertib in contrast to BRCA1-wildtype control cell lines. However, unexpectedly, only two BRCA1-mutant cell lines, HCC1937 and MDA-MB-436, were hypersensitive to a nucleotide analogue 6-thioguanine (6-TG). SUM149PT cells readily formed radiation-induced RAD51-positive nuclear foci indicating a functional homologous recombination, which may explain their resistance to 6-TG. However, the reason underlying 6-TG resistance of SUM1315MO2 cells remains unclear. Our data reveal a remarkable heterogeneity among BRCA1-mutant cell lines and provide a reference for future studies. PMID:27313062

  19. Intragastric acidification increases the sensitivity of 14C-urea breath test in patients taking a proton pump inhibitor

    International Nuclear Information System (INIS)

    Objective: To investigate if intragastric acidification at the ingestion of 14C-urea can decrease the likelihood of false-negative (FN) results of urea breath test (UBT) in patients taking a proton pump inhibitor (PPI). Methods: Twenty-three patients with positive 14C-UBT (UBT-1) results underwent an acid suppression treatment with omeprazole 40 mg/d for 14 d. On day 13, patients underwent second standard UBT (YBT-2). On day 14, patients underwent a modified UBT (UBT-3), which included consuming 200 mL of 0.1 mol/L citric acid solution 30 min before and at the administration of 14C-urea. Mean 14CO2 expiration and the number of FN results were compared for the three UBTs. Results: Omeprazole caused a significant decrease in mean 14CO2 excretion between UBT-1[(5.57 +- 3.90) Bq/mmol] and UBT-2[(1.98 +- 1.42) Bq/mmol, t=5.867, P=0.000]. Omeprazole caused 10(43.5%) FN UBT-2 results. Mean 14CO2 expiration in UBT-3 [(4.93 +- 3.77) Bq/mmol] was greater than that in UBT-2 (t=-4.538, P=0.000). UBT-3 caused only 2 FN results (8.7%, x2=6.66, P14C-urea increases 14Co2 expiration and decreases FN 14C-UBT results in patients taking PPI

  20. Sensitization of human cancer cells to gemcitabine by the Chk1 inhibitor MK-8776: cell cycle perturbation and impact of administration schedule in vitro and in vivo

    International Nuclear Information System (INIS)

    Chk1 inhibitors have emerged as promising anticancer therapeutic agents particularly when combined with antimetabolites such as gemcitabine, cytarabine or hydroxyurea. Here, we address the importance of appropriate drug scheduling when gemcitabine is combined with the Chk1 inhibitor MK-8776, and the mechanisms involved in the schedule dependence. Growth inhibition induced by gemcitabine plus MK-8776 was assessed across multiple cancer cell lines. Experiments used clinically relevant “bolus” administration of both drugs rather than continuous drug exposures. We assessed the effect of different treatment schedules on cell cycle perturbation and tumor cell growth in vitro and in xenograft tumor models. MK-8776 induced an average 7-fold sensitization to gemcitabine in 16 cancer cell lines. The time of MK-8776 administration significantly affected the response of tumor cells to gemcitabine. Although gemcitabine induced rapid cell cycle arrest, the stalled replication forks were not initially dependent on Chk1 for stability. By 18 h, RAD51 was loaded onto DNA indicative of homologous recombination. Inhibition of Chk1 at 18 h rapidly dissociated RAD51 leading to the collapse of replication forks and cell death. Addition of MK-8776 from 18–24 h after a 6-h incubation with gemcitabine induced much greater sensitization than if the two drugs were incubated concurrently for 6 h. The ability of this short incubation with MK-8776 to sensitize cells is critical because of the short half-life of MK-8776 in patients’ plasma. Cell cycle perturbation was also assessed in human pancreas tumor xenografts in mice. There was a dramatic accumulation of cells in S/G2 phase 18 h after gemcitabine administration, but cells had started to recover by 42 h. Administration of MK-8776 18 h after gemcitabine caused significantly delayed tumor growth compared to either drug alone, or when the two drugs were administered with only a 30 min interval. There are two reasons why delayed

  1. Profile of Steroid Receptors and Increased Aromatase Immunoexpression in Canine Inflammatory Mammary Cancer as a Potential Therapeutic Target.

    Science.gov (United States)

    De Andrés, P J; Cáceres, S; Clemente, M; Pérez-Alenza, M D; Illera, J C; Peña, L

    2016-04-01

    Canine inflammatory mammary cancer (IMC) has been proposed as a model for the study of human inflammatory breast cancer (IBC). The aims of this study were to compare the immunohistochemical expression of aromatase (Arom) and several hormone receptors [estrogen receptor α (ERα), estrogen receptor β (ERβ), progesterone receptor (PR) and androgen receptor (AR)], in 21 IMC cases vs 19 non-IMC; and to study the possible effect of letrozole on canine IMC and human inflammatory breast cancer (IBC) in vitro using IPC-366 and SUM-149 cell lines. Significant elevations of the means of Arom Total Score (TS), ERβ TS and PR TS were found in the IMC group (p = 0.025, p = 0.038 and p = 0.037, respectively). Secondary IMC tumours expressed higher levels of Arom than primary IMC (p = 0.029). Non-IMC PR- tumours contained higher levels of Arom than non-IMC PR+ tumours (p = 0.007). After the addition of letrozole, the number of IMC and IBC cells dropped drastically. The overexpression of Arom found and the results obtained in vitro further support canine IMC as a model for the study of IBC and future approaches to the treatment of dogs with mammary cancer, and especially IMC, using Arom inhibitors. PMID:26899138

  2. Profile of Steroid Receptors and Increased Aromatase Immunoexpression in Canine Inflammatory Mammary Cancer as a Potential Therapeutic Target.

    Science.gov (United States)

    De Andrés, P J; Cáceres, S; Clemente, M; Pérez-Alenza, M D; Illera, J C; Peña, L

    2016-04-01

    Canine inflammatory mammary cancer (IMC) has been proposed as a model for the study of human inflammatory breast cancer (IBC). The aims of this study were to compare the immunohistochemical expression of aromatase (Arom) and several hormone receptors [estrogen receptor α (ERα), estrogen receptor β (ERβ), progesterone receptor (PR) and androgen receptor (AR)], in 21 IMC cases vs 19 non-IMC; and to study the possible effect of letrozole on canine IMC and human inflammatory breast cancer (IBC) in vitro using IPC-366 and SUM-149 cell lines. Significant elevations of the means of Arom Total Score (TS), ERβ TS and PR TS were found in the IMC group (p = 0.025, p = 0.038 and p = 0.037, respectively). Secondary IMC tumours expressed higher levels of Arom than primary IMC (p = 0.029). Non-IMC PR- tumours contained higher levels of Arom than non-IMC PR+ tumours (p = 0.007). After the addition of letrozole, the number of IMC and IBC cells dropped drastically. The overexpression of Arom found and the results obtained in vitro further support canine IMC as a model for the study of IBC and future approaches to the treatment of dogs with mammary cancer, and especially IMC, using Arom inhibitors.

  3. Different pH-sensitivity patterns of 30 sodium channel inhibitors suggest chemically different pools along the access pathway.

    Directory of Open Access Journals (Sweden)

    Alexandra eLazar

    2015-09-01

    Full Text Available The major drug binding site of sodium channels is inaccessible from the extracellular side, drug molecules can only access it either from the membrane phase, or from the intracellular aqueous phase. For this reason, ligand-membrane interactions are as important determinants of inhibitor properties, as ligand-protein interactions. One way to probe this is to modify the pH of the extracellular fluid, which alters the ratio of charged vs. uncharged forms of some compounds, thereby changing their interaction with the membrane. In this electrophysiology study we used three different pH values: 6.0, 7.3 and 8.6 to test the significance of the protonation-deprotonation equilibrium in drug access and affinity. We investigated drugs of several different indications: carbamazepine, lamotrigine, phenytoin, lidocaine, bupivacaine, mexiletine, flecainide, ranolazine, riluzole, memantine, ritanserin, tolperisone, silperisone, ambroxol, haloperidol, chlorpromazine, clozapine, fluoxetine, sertraline, paroxetine, amitriptyline, imipramine, desipramine, maprotiline, nisoxetine, mianserin, mirtazapine, venlafaxine, nefazodone and trazodone. We recorded the pH-dependence of potency, reversibility, as well as onset/offset kinetics. As expected, we observed a strong correlation between the acidic dissociation constant (pKa of drugs and the pH-dependence of their potency. Unexpectedly, however, the pH-dependence of reversibility or kinetics showed diverse patterns, not simple correlation. Our data are best explained by a model where drug molecules can be trapped in at least two chemically different environments: A hydrophilic trap (which may be the aqueous cavity within the inner vestibule, which favors polar and less lipophilic compounds, and a lipophilic trap (which may be the membrane phase itself, and/or lipophilic binding sites on the channel. Rescue from the hydrophilic and lipophilic traps can be promoted by alkalic and acidic extracellular pH, respectively.

  4. Inhibitory Aromatase Effects of Flavonoids from Ginkgo Biloba Extracts on Estrogen Biosynthesis.

    Science.gov (United States)

    Park, Yong Joo; Choo, Wun Hak; Kim, Ha Ryong; Chung, Kyu Hyuck; Oh, Seung Min

    2015-01-01

    Ginkgo biloba extract (GBE) is a popular phytomedicine and has been used for disorders of the central nervous system, cardiovascular, renal, respiratory, and circulatory diseases. Although GBE is a complex mixture of over 300 compounds, its major components are 24% flavonoids and 6% terpene lactones. In this study, we tested the inhibitory effects of the three major flavonoids (kaempferol, quercetin, and isorhamnetin) from GBE, independently and as mixtures, on aromatase activity using JEG-3 cells (human placental cells) and recombinant proteins (human placental microsome). In both systems, kaempferol showed the strongest inhibitory effects among the three flavonoids; the flavanoid mixtures exerted increased inhibitory effects. The results of exon I.1-driven luciferase reporter gene assays supported the increased inhibitory effects of flavonoid mixtures, accompanied by suppression of estrogen biosynthesis. In the RT-PCR analysis, decreased patterns of aromatase promoter I.1 mRNA expressions were observed, which were similar to the aromatase inhibition patterns of flavonoids and their mixtures. The present study demonstrated that three flavonoids synergistically inhibit estrogen biosynthesis through aromatase inhibition, decrease CYP19 mRNA, and induce transcriptional suppression. Our results support the usefulness of flavonoids in adjuvant therapy for breast cancer by reducing estrogen levels with reduced adverse effects due to estrogen depletion. PMID:26434836

  5. Is aromatase cytochrome P450 involved in the pathogenesis of endometrioid endometrial cancer?

    NARCIS (Netherlands)

    Jongen, VHWM; Thijssen, JHH; Hollema, H; Donker, GH; Santema, JG; Van Der Zee, AGJ; Heineman, MJ

    2005-01-01

    Prospectively, the relationship between androgen levels in the utero-ovarian circulation, aromatase activity in endometrial and body fat tissue, and the presence or absence of endometrioid endometrial cancer was studied in postmenopausal women. In 43 women with endometrioid endometrial cancer and 8

  6. Estrogen receptors α and β and aromatase as independent predictors for prostate cancer outcome

    Science.gov (United States)

    Grindstad, Thea; Skjefstad, Kaja; Andersen, Sigve; Ness, Nora; Nordby, Yngve; Al-Saad, Samer; Fismen, Silje; Donnem, Tom; Khanehkenari, Mehrdad Rakaee; Busund, Lill-Tove; Bremnes, Roy M.; Richardsen, Elin

    2016-01-01

    Androgens are considered important in normal prostate physiology and prostate cancer (PCa) pathogenesis. However, androgen-targeted treatment preventing PCa recurrence is still lacking. This indicates additional mediators contributing to cancer development. We sought to determine the prognostic significance of estrogen receptors, ERα and -β, and the aromatase enzyme in PCa. Tissue microarrays were created from 535 PCa patients treated with radical prostatectomy. Expression of ERα, ERβ and aromatase were evaluated using immunohistochemistry. Representative tumor epithelial (TE) and tumor stromal (TS) areas were investigated separately. Survival analyses were used to evaluate the markers correlation to PCa outcome. In univariate analyses, ERα in TS was associated with delayed time to clinical failure (CF) (p = 0.042) and PCa death (p = 0.019), while ERβ was associated with reduced time to biochemical failure (BF) (p = 0.002). Aromatase in TS and TE was associated with increased time to BF and CF respectively (p = 0.016, p = 0.046). Multivariate analyses supported these observations, indicating an independent prognostic impact of all markers. When stratifying the analysis according to different surgical centers the results were unchanged. In conclusion, significant prognostic roles of ERα, ERβ and aromatase were discovered in the in PCa specimens of our large multicenter cohort. PMID:27610593

  7. Inhibition of AKT with the orally active allosteric AKT inhibitor, MK-2206, sensitizes endometrial cancer cells to progestin.

    Directory of Open Access Journals (Sweden)

    Alok Pant

    Full Text Available Progestin resistance is a major obstacle to treating early stage, well-differentiated endometrial cancer as well as recurrent endometrial cancer. The mechanism behind the suboptimal response to progestin is not well understood. The PTEN tumor suppressor gene is frequently mutated in type I endometrial cancers and this mutation results in hyperactivation of the PI3K/AKT pathway. We hypothesized that increased activation of AKT promotes an inadequate response to progestins in endometrial cancer cells. Ishikawa cells stably transfected with progesterone receptor B (PRB23 cells were treated with the AKT inhibitor, MK-2206, which effectively decreased levels of p(Ser473-AKT in a dose-dependent (10 nM to 1 uM and time-dependent manner (0.5 h to 24 h. MK-2206 inhibited levels of p(Thr308-AKT and a downstream target, p(Thr246-PRAS40, but did not change levels of p(Thr202/Tyr204ERK or p(Thr13/Tyr185SAPK/JNK, demonstrating specificity of MK-2206 for AKT. Additionally, MK-2206 treatment of PRB23 cells resulted in a significant increase in levels of progesterone receptor B (PRB protein. Microarray analysis of PRB23 cells identified PDK4 as the most highly upregulated gene among 70 upregulated genes in response to R5020. Inhibition of AKT further upregulated progestin-mediated expression of PDK4 but did not affect another progestin-responsive gene, SGK1. Treatment of PRB23 cells with R5020 and MK-2206 independently decreased viability of cells while the combination of R5020 and MK-2206 caused the greatest decrease in cell viability. Furthermore, mice with xenografted tumors treated with MK-2206 alone or with progesterone alone exhibited modest reductions in their tumor volume. The largest decrease in tumor size was observed in the mice treated with both MK-2206 and progesterone; these tumors exhibited the least proliferation (Ki67 and the most apoptosis (cleaved caspase-3 of all the treatment groups. In summary, inhibition of AKT stabilizes the Progesterone

  8. Electrochemiluminescence resonance energy transfer between graphene quantum dots and graphene oxide for sensitive protein kinase activity and inhibitor sensing.

    Science.gov (United States)

    Liang, Ru-Ping; Qiu, Wei-Bin; Zhao, Hui-Fang; Xiang, Cai-Yun; Qiu, Jian-Ding

    2016-01-21

    Herein, a novel electrochemiluminescence resonance energy transfer (ECL-RET) biosensor using graphene quantum dots (GQDs) as donor and graphene oxide (GO) as acceptor for monitoring the activity of protein kinase was presented for the first time. Anti-phosphoserine antibody conjugated graphene oxide (Ab-GO) nonocomposite could be captured onto the phosphorylated peptide/GQDs modified electrode surface through antibody-antigen interaction in the presence of casein kinase II (CK2) and adenosine 5'-triphosphate (ATP), resulting in ECL from the GQDs quenching by closely contacting GO. This ECL quenching degree was positively correlated with CK2 activity. Therefore, on the basis of ECL-RET between GQDs and GO, the activity of protein kinase can be detected sensitively. This biosensor can also be used for quantitative analysis CK2 activity in serum samples and qualitative screening kinase inhibition, indicating the potential application of the developed method in biochemical fundamental research and clinical diagnosis.

  9. Product of aromatase activity in intact LNCaP and MCF-7 human cancer cells.

    Science.gov (United States)

    Castagnetta, L A; Granata, O M; Bellavia, V; Amodio, R; Scaccianoce, E; Notarbartolo, M; Follari, M R; Miceli, M D; Carruba, G

    1997-04-01

    We investigated conversion rates of androgens to estrogens in cultured, hormone-responsive prostate (LNCaP) and breast (MCF-7) human cancer cells. For this purpose, we adopted an intact cell analysis, whereby cells were incubated for different incubation times in the presence of close-to-physiological (1 nM) or supraphysiological (1 microM) concentrations of labelled androgen precursors, i.e. testosterone (T) and androstenedione (delta4Ad). The aromatase activity, as measured by estrogen formation, was detected in LNCaP cells (0.5 pmol/ml), even though to a significantly lower extent than in MCF-7 cells (5.4 pmol/ml), using 1 microM T after 72 h incubation. Surprisingly, LNCaP cells displayed a much higher aromatase activity when T was used as a substrate with respect to delta4Ad. In either cell line, T transformation to delta4Ad was relatively low, attaining only 2.8% in LNCaP and 7.5% MCF-7 cells. However, T was mostly converted to conjugates (over 95%), glucuronides and some sulphates, in LNCaP cells, whereas it was only partly converted to sulphates (<10%) in MCF-7 cells. Aromatase activity seems to be inconsistent in LNCaP cells, being strongly affected by culture conditions, especially by fetal calf serum (FCS). Further studies should assess the regulation of aromatase expression by serum or growth factors in different human cancer cells, also using anti-aromatase and/or anti-estrogen compounds, in different culture conditions.

  10. Treatment of erythrocytes with the 2-cys peroxiredoxin inhibitor, Conoidin A, prevents the growth of Plasmodium falciparum and enhances parasite sensitivity to chloroquine.

    Directory of Open Access Journals (Sweden)

    Mariana Brizuela

    Full Text Available The human erythrocyte contains an abundance of the thiol-dependant peroxidase Peroxiredoxin-2 (Prx2, which protects the cell from the pro-oxidant environment it encounters during its 120 days of life in the blood stream. In malarial infections, the Plasmodium parasite invades red cells and imports Prx2 during intraerythrocytic development, presumably to supplement in its own degradation of peroxides generated during cell metabolism, especially hemoglobin (Hb digestion. Here we demonstrate that an irreversible Prx2 inhibitor, Conoidin A (2,3-bis(bromomethyl-1,4-dioxide-quinoxaline; BBMQ, has potent cytocidal activity against cultured P. falciparum. Parasite growth was also inhibited in red cells that were treated with BBMQ and then washed prior to parasite infection. These cells remained susceptible to merozoite invasion, but failed to support normal intraerythrocytic development. In addition the potency of chloroquine (CQ, an antimalarial drug that prevents the detoxification of Hb-derived heme, was significantly enhanced in the presence of BBMQ. CQ IC50 values decreased an order of magnitude when parasites were either co-incubated with BBMQ, or introduced into BBMQ-pretreated cells; these effects were equivalent for both drug-resistant and drug-sensitive parasite lines. Together these results indicate that treatment of red cells with BBMQ renders them incapable of supporting parasite growth and increases parasite sensitivity to CQ. We also propose that molecules such as BBMQ that target host cell proteins may constitute a novel host-directed therapeutic approach for treating malaria.

  11. The receptor tyrosine kinase inhibitor amuvatinib (MP470) sensitizes tumor cells to radio- and chemo-therapies in part by inhibiting homologous recombination

    International Nuclear Information System (INIS)

    Background and purpose: RAD51 is a key protein involved in homologous recombination (HR) and a potential target for radiation- and chemotherapies. Amuvatinib (formerly known as MP470) is a novel receptor tyrosine kinase inhibitor that targets c-KIT and PDGFRα and can sensitize tumor cells to ionizing radiation (IR). Here, we studied amuvatinib mechanism on RAD51 and functional HR. Materials and methods: Protein and RNA analyses, direct repeat green fluorescent protein (DR-GFP) assay and polysomal fractioning were used to measure HR efficiency and global translation in amuvatinib-treated H1299 lung carcinoma cells. Synergy of amuvatinib with IR or mitomycin c (MMC) was assessed by clonogenic survival assay. Results: Amuvaninib inhibited RAD51 protein expression and HR. This was associated with reduced ribosomal protein S6 phosphorylation and inhibition of global translation. Amuvatinib sensitized cells to IR and MMC, agents that are selectively toxic to HR-deficient cells. Conclusions: Amuvatinib is a promising agent that may be used to decrease tumor cell resistance. Our work suggests that this is associated with decreased RAD51 expression and function and supports the further study of amuvatinib in combination with chemotherapy and radiotherapy.

  12. Short- and long-term effects of interleukin-2 treatment on the sensitivity of periadolescent female mice to interleukin-2 and dopamine uptake inhibitor.

    Directory of Open Access Journals (Sweden)

    James S Rankin

    Full Text Available Interleukin (IL-2, a T-helper 1 (Th1 cell-derived cytokine, which potently modulates dopamine activity and neuronal excitability in mesolimbic structures, is linked with pathological outcomes (e.g., schizophrenia, depression, etc. that at least partly reflect alterations in central dopaminergic processes. It has been suggested that dopamine neurons undergo pruning during adolescence and abnormalities in pruning predispose individuals to behavioral disorders. Since IL-2 is known as a neurodevelopmental factor affecting associated behavioral processes, the present study tested whether IL-2 can modulate stereotypic behaviors in both the periadolescent and adult periods. This study determined whether IL-2 treatment would produce long-lasting changes in sensitivity to a later challenge with IL-2 or GBR 12909, a highly selective dopamine uptake inhibitor. Four experiments were conducted. Firstly, a decrease in novelty-induced stereotypic behavior was observed in BALB/c periadolescent mice (38 days of age following IL-2 administration (0.4 µg/2 ml relative to vehicle control. In the second experiment, an initial dose of IL-2 was given in the periadolescent period, but did not affect rearing responses. A second dose of IL-2 given to the animals 30 days later as adults, resulted in a significant increase in rearing behaviors relative to control animals. In the third experiment, separate groups of experimental and control mice were administered GBR 12909, a highly selective dopamine reuptake inhibitor, 30 days following treatment with either IL-2 or vehicle. It was noted that this experimental group, which initially received IL-2, exhibited stereotypy, as evidenced by increased sniffing behavior. A fourth experiment revealed that IL-2 administered in periadolesecence and adulthood had no effect on other motor responses, indicating that IL-2 selectively modulates selective stereotypic behaviors. The results provide evidence, for the first time, that long

  13. MMP2-Sensitive PEG-Lipid Copolymers: A New Type of Tumor-Targeted P-Glycoprotein Inhibitor.

    Science.gov (United States)

    Dai, Zhi; Yao, Qing; Zhu, Lin

    2016-05-25

    Low tumor targetability and multidrug resistance (MDR) are two major impediments to the success of cancer treatments. Nanomaterials which possess high tumor targetability and the ability to reverse the MDR are rare. This report describes a new type of self-assembling polyethylene glycol-phosphoethanolamine-based copolymers (PEG-pp-PE) which showed both the matrix metalloproteinase 2 (MMP2)-sensitive tumor-targeted drug delivery and ability to inhibit the P-glycoprotein (P-gp)-mediated drug efflux. In this study, we synthesized a series of the homologous analogues of PEG-pp-PE copolymers and investigated the influence of their structures, including PEG lengths and peptide linkers, on the drug efflux, and identified the underlying mechanisms. We found that the whole structure (PEG-peptide-lipid) rather than any parts of the copolymers was key for the P-gp inhibition and a delicate balance between the hydrophilic and lipophilic segments of the PEG-pp-PE copolymers was needed for better modulating the P-gp-mediated drug efflux. The best copolymer, PEG2k-pp-PE, showed even higher P-gp inhibition effect than the d-α-tocopherol polyethylene glycol 1000 succinate (TPGS1k). We also found that the P-gp inhibition capability of PEG-pp-PE copolymers was highly associated with the P-gp down-regulation, the increase in the plasma membrane fluidity, and the inhibition of the P-gp ATPase activity. Besides, the excellent physicochemical properties, high drug loading, MMP2-dependent drug release, and improved drug efficacy in the MDR cancer cells suggested that the PEG-pp-PE copolymers might have great potential for building tumor-targeted drug delivery systems for treating drug-resistant cancers. PMID:27145021

  14. Effects of Pharmaceuticals Used for Breast Cancer Treatment on Reproduction and Aromatase Activity in a Marine Fish

    Science.gov (United States)

    Laboratory experiments were conducted with the marine fish cunner (Tautogolabrus adspersus) to evaluate whether four pharmaceuticals used in breast cancer treatment have an impact on reproduction or aromatase activity. Tamoxifen binds to estrogen receptors, while anastrozole, let...

  15. EFFECTS OF INCUBATION TEMPERATURE AND ESTROGEN EXPOSURE ON AROMATASE ACTIVITY IN THE BRAIN AND GONADS OF EMBRYONIC ALLIGATORS

    Science.gov (United States)

    During embryogenesis, incubation temperature and the hormonal environment influence gonadal differentiation of some reptiles, including all crocodilians. Current evidence suggests that aromatase, the enzyme that converts androgens to estrogens, has a role in sexual differentiatio...

  16. Post-proliferative immature radial glial cells female-specifically express aromatase in the medaka optic tectum.

    Directory of Open Access Journals (Sweden)

    Akio Takeuchi

    Full Text Available Aromatase, the key enzyme responsible for estrogen biosynthesis, is present in the brain of all vertebrates. Much evidence has accumulated that aromatase is highly and exclusively expressed in proliferating mature radial glial cells in the brain of teleost fish even in adulthood, unlike in other vertebrates. However, the physiological significance of this expression remains unknown. We recently found that aromatase is female-specifically expressed in the optic tectum of adult medaka fish. In the present study, we demonstrated that, contrary to the accepted view of the teleost brain, female-specific aromatase-expressing cells in the medaka optic tectum represent a transient subset of post-proliferative immature radial glial cells in the neural stem cell lineage. This finding led us to hypothesize that female-specific aromatase expression and consequent estrogen production causes some sex difference in the life cycle of tectal cells. As expected, the female tectum exhibited higher expression of genes indicative of cell proliferation and radial glial maturation and lower expression of an anti-apoptotic gene than did the male tectum, suggesting a female-biased acceleration of the cell life cycle. Complicating the interpretation of this result, however, is the additional observation that estrogen administration masculinized the expression of these genes in the optic tectum, while simultaneously stimulating aromatase expression. Taken together, these results provide evidence that a unique subpopulation of neural stem cells female-specifically express aromatase in the optic tectum and suggest that this aromatase expression and resultant estrogen synthesis have an impact on the life cycle of tectal cells, whether stimulatory or inhibitory.

  17. C6 ceramide sensitizes the anti-hepatocellular carcinoma (HCC) activity by AZD-8055, a novel mTORC1/2 dual inhibitor.

    Science.gov (United States)

    Liu, Mo; Gu, Peng; Guo, Wenjia; Fan, Xiwen

    2016-08-01

    Aberrant activation of mammalian target of rapamycin (mTOR) plays pivotal roles in promoting hepatocellular carcinoma (HCC) tumorigenesis and chemoresistance. Here, we tested the potential anti-HCC activity by a novel mTOR complex 1/2 (mTORC1/2) dual inhibitor AZD-8055 and, more importantly, the potential AZD-8055 sensitization effect by a cell-permeable short-chain ceramide (C6). We showed that AZD-8055 mainly exerted moderate cytotoxic effect against a panel of HCC cell lines (HepG2, Hep3B, and SMMC-7721). Co-treatment of C6 ceramide remarkably augmented AZD-8055-induced HCC cytotoxicity. Meanwhile, C6 ceramide dramatically potentiated AZD-8055-induced HCC cell apoptotic death. Further studies demonstrated that AZD-8055 and C6 ceramide synergistically induced anti-survival and pro-apoptotic activity in primary cultured human HCC cells, but not in the non-cancerous human hepatocytes. Signaling studies showed that AZD-8055 and C6 ceramide synergistically suppressed Akt-mTOR complex 1/2 cascade activation. In vivo, AZD-8055 oral administration suppressed HepG2 hepatoma xenograft growth in nude mice, while moderately improving mice survival. Its anti-tumor activity was dramatically potentiated with co-administration of a liposome-packed C6 ceramide. Together, these results demonstrate that concurrent targeting mTORC1/2 by AZD-8055 exerts anti-tumor ability in preclinical HCC models, and its activity is further sensitized with co-administration of C6 ceramide.

  18. TRIM5α and TRIMCyp form apparent hexamers and their multimeric state is not affected by exposure to restriction-sensitive viruses or by treatment with pharmacological inhibitors

    Directory of Open Access Journals (Sweden)

    Berthoux Lionel

    2009-11-01

    Full Text Available Abstract Proteins of the TRIM5 family, such as TRIM5α and the related TRIMCyp, are cytoplasmic factors that can inhibit incoming retroviruses. This type of restriction requires a direct interaction between TRIM5 proteins and capsid proteins that are part of mature, intact retroviral cores. In such cores, capsids are arranged as hexameric units. Multiple lines of evidence imply that TRIM5 proteins themselves interact with retroviral cores as multimers. Accordingly, stabilization by crosslinking agents has revealed that TRIM5α and TRIMCyp are present as trimers in mammalian cells. We report here that TRIM5 proteins seem to form dimers, trimers, hexamers and multimers of higher complexity in mammalian cells. The hexameric form in particular seems to be the most abundant multimer. Multimerization did not involve disulfide bridges and was not affected by infection with restriction-sensitive viruses or by treatment with the known TRIM5 inhibitors arsenic trioxide, MG132 and cyclosporine A. We conclude that TRIM5 multimerization results from more than one protein-protein interface and that it is seemingly not triggered by contact with retroviral cores.

  19. Activation of G551D-CFTR by Bicyclooctane Compounds Is cAMP-dependent and Exhibits Low Sensitivity to Thiazolidinone CFTR Inhibitor CFTRinh-172

    Institute of Scientific and Technical Information of China (English)

    WANG Ying; ZHAO Lu; HE Cheng-yan; XU Li-na; YANG Hong

    2005-01-01

    The G551D-CFTR mutation causing cystic fibrosis (CF) results from a missense mutation at codon 551(G551D) in the gene encoding of the cystic fibrosis transmembrane conductance regulator (CFTR). The G551D mutation in CFTR results in a reduced functional channel but G551D-CFTR is appropriately inserted in the apical membrane. In previous studies we discovered a class of high-affinity bicyclooctane (BCO)G551D-CFTR activators(G551DBCOs) with Kd down to 1μmol/L. In this study, we analyzed the pharmacological activation of G551D-CFTR by the G551DBcos by means of short circuit current analysis and cell-based fluorescence quenching assay. The G551DBCOs-induced G551D-CFTR activation is cAMP-dependent and is less sensitive to thiazolidinone CFTR inhibitor CFTRinh-172. These data suggest that (1) the phosphorylation of G551D-CFTR by protein kinase A is required for the activation by G551DBcos; (2) G551DBCos and CFTRinh-172 may act at the same site on the G551D-CFTR molecule.

  20. Xanthones from the botanical dietary supplement mangosteen (Garcinia mangostana) with aromatase inhibitory activity.

    Science.gov (United States)

    Balunas, Marcy J; Su, Bin; Brueggemeier, Robert W; Kinghorn, A Douglas

    2008-07-01

    Twelve xanthone constituents of the botanical dietary supplement mangosteen (the pericarp of Garcinia mangostana) were screened using a noncellular, enzyme-based microsomal aromatase inhibition assay. Of these compounds, garcinone D (3), garcinone E (5), alpha-mangostin (8), and gamma-mangostin (9) exhibited dose-dependent inhibitory activity. In a follow-up cell-based assay using SK-BR-3 breast cancer cells that express high levels of aromatase, the most potent of these four xanthones was gamma-mangostin (9). Because xanthones may be consumed in substantial amounts from commercially available mangosteen products, the consequences of frequent intake of mangosteen botanical dietary supplements require further investigation to determine their possible role in breast cancer chemoprevention.

  1. Novel irreversible EGFR tyrosine kinase inhibitor 324674 sensitizes human colon carcinoma HT29 and SW480 cells to apoptosis by blocking the EGFR pathway

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Zhiwei; Cui, Binbin; Jin, Yinghu; Chen, Haipeng [Division of Colorectal Surgery, Third Affiliated Hospital of Harbin Medical University, Harbin (China); Wang, Xishan, E-mail: wxshan_oncologist@yahoo.com.cn [Division of Colorectal Surgery, Third Affiliated Hospital of Harbin Medical University, Harbin (China)

    2011-08-12

    Highlights: {yields} This article described the effects of the EGFR tyrosine kinase inhibitor on the cell proliferation and the apoptosis induction of the colon carcinoma cell lines. {yields} Demonstrated that 326474 is a more potent EGFR inhibitor on colon cancer cells than other three TKIs. {yields} It can be important when considering chemotherapy for colonic cancer patients. -- Abstract: Background: Epidermal growth factor receptor (EGFR) is widely expressed in multiple solid tumors including colorectal cancer by promoting cancer cell growth and proliferation. Therefore, the inhibition of EGFR activity may establish a clinical strategy of cancer therapy. Methods: In this study, using human colon adenocarcinoma HT29 and SW480 cells as research models, we compared the efficacy of four EGFR inhibitors in of EGFR-mediated pathways, including the novel irreversible inhibitor 324674, conventional reversible inhibitor AG1478, dual EGFR/HER2 inhibitor GW583340 and the pan-EGFR/ErbB2/ErbB4 inhibitor. Cell proliferation was assessed by MTT analysis, and apoptosis was evaluated by the Annexin-V binding assay. EGFR and its downstream signaling effectors were examined by western blotting analysis. Results: Among the four inhibitors, the irreversible EGFR inhibitor 324674 was more potent at inhibiting HT29 and SW480 cell proliferation and was able to efficiently induce apoptosis at lower concentrations. Western blotting analysis revealed that AG1478, GW583340 and pan-EGFR/ErbB2/ErbB4 inhibitors failed to suppress EGFR activation as well as the downstream mitogen-activated protein kinase (MAPK) and PI3K/AKT/mTOR (AKT) pathways. In contrast, 324674 inhibited EGFR activation and the downstream AKT signaling pathway in a dose-dependent manner. Conclusion: Our studies indicated that the novel irreversible EGFR inhibitor 324674 may have a therapeutic application in colon cancer therapy.

  2. Inhibition of human placental aromatase activity by hydroxylated polybrominated diphenyl ethers (OH-PBDEs)

    International Nuclear Information System (INIS)

    Polybrominated diphenyl ethers (PBDEs) are widely used as flame retardants in many different polymers, resins and substrates. Due to their widespread production and use, their high binding affinity to particles, and their lipophilic properties, several PBDE congeners can bioaccumulate in the environment. As a result, PBDEs and their hydroxylated metabolites (OH-PBDEs) have been detected in humans and various wildlife samples, such as birds, seals, and whales. Furthermore, certain OH-PBDEs and their methoxylated derivatives (MeO-PBDEs) are natural products in the marine environment. Recently, our laboratory focused on the possible effects on steroidogenesis of PBDEs and OH-PBDEs, e.g. in the human adrenocortical carcinoma (H295R) cell line indicating that some OH-PBDEs can significantly influence steroidogenic enzymes like CYP19 (aromatase) and CYP17. In the present study, human placental microsomes have been used to study the possible interaction of twenty two OH-PBDEs and MeO-PBDEs with aromatase, the enzyme that mediates the conversion of androgens into estrogens. All OH-PBDE derivates showed significant inhibition of placental aromatase activity with IC50 values in the low micromolar range, while the MeO-PBDEs did not have any effect on this enzyme activity. Enzyme kinetics studies indicated that two OH-PBDEs, 5-hydroxy-2,2',4,4'-tetrabromodiphenyl ether (5-OH-BDE47) and 6-hydroxy-2,2',4,4'-tetrabromodiphenyl ether (6-OH-BDE47), had a mixed-type inhibition of aromatase activity with apparent Ki/Ki' of 7.68/0,02 μM and 5.01/0.04 μM respectively. For comparison, some structurally related compounds, a dihydroxylated polybrominated biphenyl, which is a natural product (2,2'-dihyroxy-3,3',5,5'-tetrabromobiphenyl (2,2'-diOH-BB80)) and its non-bromo derivative were also included in the study. Again inhibition of aromatase activity could be measured, but their potency was significantly less than those observed for the OH-PBDEs. These results show that a wide range of

  3. Neural stem cell sex dimorphism in aromatase (CYP19 expression: a basis for differential neural fate

    Directory of Open Access Journals (Sweden)

    Jay Waldron

    2010-11-01

    Full Text Available Jay Waldron1, Althea McCourty1, Laurent Lecanu1,21The Research Institute of the McGill University Health Centre, Montreal, Canada; 2Department of Medicine, McGill University, Quebec, CanadaPurpose: Neural stem cell (NSC transplantation and pharmacologic activation of endogenous neurogenesis are two approaches that trigger a great deal of interest as brain repair strategies. However, the success rate of clinical attempts using stem cells to restore neurologic functions altered either after traumatic brain injury or as a consequence of neurodegenerative disease remains rather disappointing. This suggests that factors affecting the fate of grafted NSCs are largely understudied and remain to be characterized. We recently reported that aging differentially affects the neurogenic properties of male and female NSCs. Although the sex steroids androgens and estrogens participate in the regulation of neurogenesis, to our knowledge, research on how gender-based differences affect the capacity of NSCs to differentiate and condition their neural fate is lacking. In the present study, we explored further the role of cell sex as a determining factor of the neural fate followed by differentiating NSCs and its relationship with a potential differential expression of aromatase (CYP19, the testosterone-metabolizing enzyme.Results: Using NSCs isolated from the subventricular zone of three-month-old male and female Long-Evans rats and maintained as neurospheres, we showed that differentiation triggered by retinoic acid resulted in a neural phenotype that depends on cell sex. Differentiated male NSCs mainly expressed markers of neuronal fate, including ßIII-tubulin, microtubule associated protein 2, growth-associated protein 43, and doublecortin. In contrast, female NSCs essentially expressed the astrocyte marker glial fibrillary acidic protein. Quantification of the expression of aromatase showed a very low level of expression in undifferentiated female NSCs

  4. Multiple CCR5 Conformations on the Cell Surface Are Used Differentially by Human Immunodeficiency Viruses Resistant or Sensitive to CCR5 Inhibitors

    NARCIS (Netherlands)

    R. Berro; P.J. Klasse; D. Lascano; A. Flegler; K.A. Nagashima; R.W. Sanders; T.P. Sakmar; T.J. Hope; J.P. Moore

    2011-01-01

    Resistance to small-molecule CCR5 inhibitors arises when HIV-1 variants acquire the ability to use inhibitor-bound CCR5 while still recognizing free CCR5. Two isolates, CC101.19 and D1/85.16, became resistant via four substitutions in the gp120 V3 region and three in the gp41 fusion peptide (FP), re

  5. Selective imidazoline agonist moxonidine plus the ACE inhibitor ramipril in hypertensive patients with impaired insulin sensitivity: partners in a successful MARRIAGE?

    Science.gov (United States)

    Rayner, Brian

    2004-03-01

    Hypertension in combination with clinically overt diabetes mellitus is recognized as a particularly powerful combination of risk factors that greatly increases cardiovascular vulnerability. There is also evidence that presumed pre-diabetic conditions such as insulin resistance, hyperinsulinaemia and compensatory hyperglycaemia may amplify overall cardiovascular risk in patients with hypertension, especially when encountered as part of the condition known as metabolic syndrome X (Reaven's syndrome). The long-term benefits of antihypertensive therapy may be compromised if these drugs exert adverse effects on metabolic parameters such as insulin sensitivity, or if they promote a transition from pre-diabetes to overt diabetes. Class differences in the effects of antihypertensives on metabolic indices may therefore be an important consideration when choosing treatment for patients who exhibit these characteristics. Experience from clinical trials suggests that drugs that target the renin-angiotensin system may have metabolic advantages over drugs such as beta-blockers and diuretics, but this conclusion has not been proved definitively. Moxonidine, which selectively targets imidazoline type-1 receptors in the sympathetic vasomotor centres of the rostral-ventrolateral medulla, is an effective antihypertensive and has been reported to exert favourable metabolic effects in preclinical and clinical studies. The MARRIAGE study (Moxonidine And Ramipril Regarding Insulin And Glucose Evaluation) will extend these preliminary observations by comparing the effects of moxonidine and the ACE inhibitor ramipril--and the combination of both drugs--on metabolic and haemodynamic parameters in patients with hypertension and impaired fasting glycaemia. A description is provided of the design and conduct of MARRIAGE.

  6. Histone deacetylase inhibitors sensitize lung cancer cells to hyperthermia: involvement of Ku70/SirT-1 in thermo-protection.

    Science.gov (United States)

    Hassan, Mohamed K; Watari, Hidemichi; Salah-Eldin, Alaa-Eldin; Sultan, Ahmed S; Mohamed, Zainab; Fujioka, Yoichiro; Ohba, Yusuke; Sakuragi, Noriaki

    2014-01-01

    This study describes the sensitization mechanism to thermal stress by histone deacetylase inhibitors (HDACIs) in lung cancer cells and shows that Ku70, based on its acetylation status, mediates the protection of lung cancer from hyperthermia (42.5°C, 1-6 hrs). Ku70 regulates apoptosis by sequestering pro-apoptotic Bax. However, its role in thermal stress is not fully understood. The findings showed that, pre-treating lung cancer cells with HDACIs, nicotinamide (NM) or Trichostatin A (TsA) or both significantly enhanced hyperthermia-induced Bax-dependent apoptosis in PC-10 cells. We found that hyperthermia induces SirT-1, Sirtuin, upregulation but not HDAC6 or SirT-3, therefore transfection with dominant negative SirT-1 (Y/H) also eliminated the protection and resulted in more cell death by hyperthermia, in H1299 cells through Bax activation. Hyperthermia alone primed lung cancer cells to apoptosis without prominent death. After hyperthermia Bax was upregulated, Bcl-2 was downregulated, the Bax/Bcl-2 ratio was inversed and Bax/Bcl-2 heterodimer was dissociated. Although hyperthermia did not affect total Ku70 expression level, it stimulated Ku70 deacetylation, which in turn could bind more Bax in the PC-10 cells. These findings suggest an escape mechanism from hyperthermia-induced Bax activation. To verify the role of Ku70 in this protection mechanism, Ku70 was silenced by siRNA. Ku70 silencing significantly sensitized the lung cancer cells to hyperthermia. The Ku70 KD cells underwent cytotoxic G1 arrest and caspase-dependant apoptosis when compared to scrambled transfectants which showed only G2/M cytostatic arrest in the cell lines investigated, suggesting an additional cell cycle-dependent, novel, role of Ku70 in protection from hyperthermia. Taken together, our data show a Ku70-dependent protection mechanism from hyperthermia. Targeting Ku70 and/or its acetylation during hyperthermia may represent a promising therapeutic approach for lung cancer. PMID:24728004

  7. Histone deacetylase inhibitors sensitize lung cancer cells to hyperthermia: involvement of Ku70/SirT-1 in thermo-protection.

    Directory of Open Access Journals (Sweden)

    Mohamed K Hassan

    Full Text Available This study describes the sensitization mechanism to thermal stress by histone deacetylase inhibitors (HDACIs in lung cancer cells and shows that Ku70, based on its acetylation status, mediates the protection of lung cancer from hyperthermia (42.5°C, 1-6 hrs. Ku70 regulates apoptosis by sequestering pro-apoptotic Bax. However, its role in thermal stress is not fully understood. The findings showed that, pre-treating lung cancer cells with HDACIs, nicotinamide (NM or Trichostatin A (TsA or both significantly enhanced hyperthermia-induced Bax-dependent apoptosis in PC-10 cells. We found that hyperthermia induces SirT-1, Sirtuin, upregulation but not HDAC6 or SirT-3, therefore transfection with dominant negative SirT-1 (Y/H also eliminated the protection and resulted in more cell death by hyperthermia, in H1299 cells through Bax activation. Hyperthermia alone primed lung cancer cells to apoptosis without prominent death. After hyperthermia Bax was upregulated, Bcl-2 was downregulated, the Bax/Bcl-2 ratio was inversed and Bax/Bcl-2 heterodimer was dissociated. Although hyperthermia did not affect total Ku70 expression level, it stimulated Ku70 deacetylation, which in turn could bind more Bax in the PC-10 cells. These findings suggest an escape mechanism from hyperthermia-induced Bax activation. To verify the role of Ku70 in this protection mechanism, Ku70 was silenced by siRNA. Ku70 silencing significantly sensitized the lung cancer cells to hyperthermia. The Ku70 KD cells underwent cytotoxic G1 arrest and caspase-dependant apoptosis when compared to scrambled transfectants which showed only G2/M cytostatic arrest in the cell lines investigated, suggesting an additional cell cycle-dependent, novel, role of Ku70 in protection from hyperthermia. Taken together, our data show a Ku70-dependent protection mechanism from hyperthermia. Targeting Ku70 and/or its acetylation during hyperthermia may represent a promising therapeutic approach for lung cancer.

  8. miR-378a-3p modulates tamoxifen sensitivity in breast cancer MCF-7 cells through targeting GOLT1A

    NARCIS (Netherlands)

    Ikeda, Kazuhiro; Horie-Inoue, Kuniko; Ueno, Toshihide; Suzuki, Takashi; Sato, Wataru; Shigekawa, Takashi; Osaki, Akihiko; Saeki, Toshiaki; Berezikov, Eugene; Mano, Hiroyuki; Inoue, Satoshi

    2015-01-01

    Breast cancer is a hormone-dependent cancer and usually treated with endocrine therapy using aromatase inhibitors or anti-estrogens such as tamoxifen. A majority of breast cancer, however, will often fail to respond to endocrine therapy. In the present study, we explored miRNAs associated with endoc

  9. Currently used pesticides and their mixtures affect the function of sex hormone receptors and aromatase enzyme activity

    International Nuclear Information System (INIS)

    The endocrine-disrupting potential of pesticides is of health concern, since they are found ubiquitously in the environment and in food items. We investigated in vitro effects on estrogen receptor (ER) and androgen receptor (AR) transactivity, and aromatase enzyme activity, of the following pesticides: 2-methyl-4-chlorophenoxyacetic acid (MCPA), terbuthylazine, iodosulfuron-methyl-sodium, mesosulfuron-methyl, metsulfuron-methyl, chlormequat chloride, bitertanol, propiconazole, prothioconazole, mancozeb, cypermethrin, tau fluvalinate, malathion and the metabolite ethylene thiourea (ETU). The pesticides were analyzed alone and in selected mixtures. Effects of the pesticides on ER and AR function were assessed in human breast carcinoma MVLN cells and hamster ovary CHO-K1 cells, respectively, using luciferase reporter gene assays. Effects on aromatase enzyme activity were analyzed in human choriocarcinoma JEG-3 cells, employing the classical [3H]2O method. Five pesticides (terbuthylazine, propiconazole, prothioconazole, cypermethrin and malathion) weakly induced the ER transactivity, and three pesticides (bitertanol, propiconazole and mancozeb) antagonized the AR activity in a concentration-dependent manner. Three pesticides (terbuthylazine, propiconazole and prothioconazole) weakly induced the aromatase activity. In addition, two mixtures, consisting of three pesticides (bitertanol, propiconazole, cypermethrin) and five pesticides (terbuthylazine, bitertanol, propiconazole, cypermethrin, malathion), respectively, induced the ER transactivity and aromatase activity, and additively antagonized the AR transactivity. In conclusion, our data suggest that currently used pesticides possess endocrine-disrupting potential in vitro which can be mediated via ER, AR and aromatase activities. The observed mixture effects emphasize the importance of considering the combined action of pesticides in order to assure proper estimations of related health effect risks. - Highlights:

  10. Currently used pesticides and their mixtures affect the function of sex hormone receptors and aromatase enzyme activity

    Energy Technology Data Exchange (ETDEWEB)

    Kjeldsen, Lisbeth Stigaard; Ghisari, Mandana; Bonefeld-Jørgensen, Eva Cecilie, E-mail: ebj@mil.au.dk

    2013-10-15

    The endocrine-disrupting potential of pesticides is of health concern, since they are found ubiquitously in the environment and in food items. We investigated in vitro effects on estrogen receptor (ER) and androgen receptor (AR) transactivity, and aromatase enzyme activity, of the following pesticides: 2-methyl-4-chlorophenoxyacetic acid (MCPA), terbuthylazine, iodosulfuron-methyl-sodium, mesosulfuron-methyl, metsulfuron-methyl, chlormequat chloride, bitertanol, propiconazole, prothioconazole, mancozeb, cypermethrin, tau fluvalinate, malathion and the metabolite ethylene thiourea (ETU). The pesticides were analyzed alone and in selected mixtures. Effects of the pesticides on ER and AR function were assessed in human breast carcinoma MVLN cells and hamster ovary CHO-K1 cells, respectively, using luciferase reporter gene assays. Effects on aromatase enzyme activity were analyzed in human choriocarcinoma JEG-3 cells, employing the classical [{sup 3}H]{sub 2}O method. Five pesticides (terbuthylazine, propiconazole, prothioconazole, cypermethrin and malathion) weakly induced the ER transactivity, and three pesticides (bitertanol, propiconazole and mancozeb) antagonized the AR activity in a concentration-dependent manner. Three pesticides (terbuthylazine, propiconazole and prothioconazole) weakly induced the aromatase activity. In addition, two mixtures, consisting of three pesticides (bitertanol, propiconazole, cypermethrin) and five pesticides (terbuthylazine, bitertanol, propiconazole, cypermethrin, malathion), respectively, induced the ER transactivity and aromatase activity, and additively antagonized the AR transactivity. In conclusion, our data suggest that currently used pesticides possess endocrine-disrupting potential in vitro which can be mediated via ER, AR and aromatase activities. The observed mixture effects emphasize the importance of considering the combined action of pesticides in order to assure proper estimations of related health effect risks

  11. Testosterone treatment increases androgen receptor and aromatase gene expression in myotubes from patients with PCOS and controls, but does not induce insulin resistance

    DEFF Research Database (Denmark)

    Eriksen, Mette Brandt; Glintborg, Dorte; Nielsen, Michael Friberg Bruun;

    2014-01-01

    Polycystic ovary syndrome (PCOS) is associated with insulin resistance and increased risk of type 2 diabetes. Skeletal muscle is the major site of insulin mediated glucose disposal and the skeletal muscle tissue is capable to synthesize, convert and degrade androgens. Insulin sensitivity is conse......Polycystic ovary syndrome (PCOS) is associated with insulin resistance and increased risk of type 2 diabetes. Skeletal muscle is the major site of insulin mediated glucose disposal and the skeletal muscle tissue is capable to synthesize, convert and degrade androgens. Insulin sensitivity...... is conserved in cultured myotubes (in vitro) from patients with PCOS, but the effect of testosterone on this insulin sensitivity is unknown. We investigated the effect of 7days testosterone treatment (100nmol/l) on glucose transport and gene expression levels of hormone receptors and enzymes involved...... in the synthesis and conversion of testosterone (HSD17B1, HSD17B2, CYP19A1, SRD5A1-2, AR, ER-α, HSD17B6 and AKR1-3) in myotubes from ten patients with PCOS and ten matched controls. Testosterone treatment significantly increased aromatase and androgen receptor gene expression levels in patients and controls...

  12. Gossypol enantiomers potently inhibit human placental 3β-hydroxysteroid dehydrogenase 1 and aromatase activities.

    Science.gov (United States)

    Dong, Yaoyao; Mao, Baiping; Li, Linxi; Guan, Hongguo; Su, Ying; Li, Xiaoheng; Lian, Qingquan; Huang, Ping; Ge, Ren-Shan

    2016-03-01

    Gossypol is a chemical isolated from cotton seeds. It exists as (+) or (-) enantiomer and has been tested for anticancer, abortion-inducing, and male contraception. Progesterone formed from pregnenolone by 3β-hydroxysteroid dehydrogenase 1 (HSD3B1) and estradiol from androgen by aromatase (CYP19A1) are critical for the maintenance of pregnancy or associated with some cancers. In this study we compared the potencies of (+)- and (-)-gossypol enantiomers in the inhibition of HSD3B1 and aromatase activities as well as progesterone and estradiol production in human placental JEG-3 cells. (+) Gossypol showed potent inhibition on human placental HSD3B1 with IC50 value of 2.3 μM, while (-) gossypol weakly inhibited it with IC50 over 100 μM. In contrast, (-) gossypol moderately inhibited CYP19A1 activity with IC50 of 23 μM, while (+) gossypol had no inhibition when the highest concentration (100 μM) was tested. (+) Gossypol enantiomer competitively inhibited HSD3B1 against substrate pregnenolone and showed mixed mode against NAD(+). (-) Gossypol competitively inhibited CYP19A1 against substrate testosterone. Gossypol enantiomers showed different potency related to their inhibition on human HSD3B1 and CYP19A1. Whether gossypol enantiomer is used alone or in combination relies on its application and beneficial effects. PMID:26709042

  13. Aromatase, adiposity, aging and disease. The hypogonadal-metabolic-atherogenic-disease and aging connection.

    Science.gov (United States)

    Cohen, P G

    2001-06-01

    In males, aging, health and disease are processes that occur over physiologic time and involve a cascade of hormonal, biochemical and physiological changes that accompany the down-regulation of the hypothalamic-anterior pituitary-testicular axis. As aging progresses there are relative increases of body fat and decreases in muscle mass. The increased adipose tissue mass is associated with the production of a number of newly generated factors. These include aromatase, leptin, PAI-1, insulin resistance, and the dyslipidemias, all of which can lead to tissue damage. Fatty tissue becomes the focal point for study as it represents the intersection between energy storage and mobilization. The increase in adipose tissue is associated with an increase in the enzyme aromatase that converts testosterone to estradiol and leads to diminished testosterone levels that favor the preferential deposition of visceral fat. As the total body fat mass increases, hormone resistance develops for leptin and insulin. Increasing leptin fails to prevent weight gain and the hypogonadal-obesity cycle ensues causing further visceral obesity and insulin resistance. The progressive insulin resistance leads to a high triglyceride-low HDL pattern of dyslipidemia and increased cardiovascular risk. All of these factors eventually contribute to the CHAOS Complex: coronary disease, hypertension, adult-onset diabetes mellitus, obesity and/or stroke as permanent changes unfold. Other consequences of the chronic hypogonadal state include osteopenia, extreme fatigue, depression, insomnia, loss of aggressiveness and erectile dysfunction all of which develop over variable periods of time. PMID:11399122

  14. Total levels of tissue inhibitor of metalloproteinases 1 in plasma yield high diagnostic sensitivity and specificity in patients with colon cancer

    DEFF Research Database (Denmark)

    Holten-Andersen, Mads N; Christensen, Ib Jarle; Nielsen, Hans Jørgen;

    2002-01-01

    PURPOSE: The purpose of this study was to measure total levels of tissue inhibitor of metalloproteinases (TIMP-1) by ELISA in plasma from blood donors, patients with inflammatory bowel disease (IBD), and patients with cancer and to correlate the results to patient diagnosis. EXPERIMENTAL DESIGN: ...

  15. Dissociation between skeletal muscle inhibitor-{kappa}B kinase/nuclear factor-{kappa}B pathway activity and insulin sensitivity in nondiabetic twins

    DEFF Research Database (Denmark)

    Friedrichsen, Martin; Ribel-Madsen, Rasmus; Wojtaszewski, Jørgen;

    2010-01-01

    Context: Several studies suggest a link between increased activity of the inflammatory inhibitor-kappaB kinase/nuclear factor-kappaB (IKK/NF-kappaB) pathway in skeletal muscle and insulin resistance. Objective: We aimed to study the regulation of skeletal muscle IKK/NF-kappaB pathway activity as ...

  16. 血清CA125联合子宫内膜芳香化酶检测诊断子宫内膜异位症%Diagnostic value of serum CA125 level and endometrial aromatase detection to endometriosis

    Institute of Scientific and Technical Information of China (English)

    邹华兰; 洛若愚; 熊霞鹂

    2011-01-01

    目的:探讨血清CA125、子宫内膜芳香化酶检测诊断子宫内膜异住症(endometriosis,EMs)的价值,方法:经腹腔镜或开腹手术确诊的EMs患者40例(EMs组),因盆腔炎行腹腔镜手术且排除EMs的患者20例(对照组),术前均抽血检测血清CA125水平,术中取其子宫内膜,采用免疫组织化学法检测芳香化酶的表达情况,并进行比较.结果:EMs组血清CA125水平高于对照组(P0.05).以血清CAl25≥35 μ/mL为临界值,诊断EMs的敏感性为55.0%,特异性为80.O%;免疫组织化学检测子宫内膜芳香化酶诊断EMs的敏感性为92.5%.特异性为90.0%;2种方法联合检测诊断EMs的敏感性95.0%,特异性70.5%.结论:血清CA125联合子宫内膜芳香化酶检测可提高EMs的早期诊断率和诊断准确性.%Objective To explore the value of serum CA125 level and endometrial aromatase detection to the diagnosis of endometriosis. Methods Forty patients with endometriosis diagnosed by laparoscopy or laparotomy (endometriosis group) and 20 patients receiving laparoscopy due to pelvic inflammatory disease(control group) were detected the serum CA125 level before operation. The expression of aromatase protein was detected with immunohistochemistry. The results were compared between two groups. Results Serum CA125 level was higher in endometriosis group than that in control group(P<0.05), and was higher in Ⅲ to Ⅳ stage of endometriosis than that in Ⅰ to Ⅱ stage (P<0.05). Aromatase expression of eutopic endometrium was higher in endometriosis group than that in control group(P<0.05), and showed no significant difference between Ⅲ to Ⅳ stage and Ⅰ to Ⅱ stages(P>0.05). As the cut-off of serum CA125≥35 u/mL, the sensitivity for endometriosis was 55.0% and the specificity was 80.0%. The diagnostic sensitivity of endometrial aromatase expression detected with immunohistochemistry was 92.5 % and the specificity was 90.0 %. The sensitivity of the combined methods for

  17. Currently used pesticides and their mixtures affect the function of sex hormone receptors and aromatase enzyme activity.

    Science.gov (United States)

    Kjeldsen, Lisbeth Stigaard; Ghisari, Mandana; Bonefeld-Jørgensen, Eva Cecilie

    2013-10-15

    The endocrine-disrupting potential of pesticides is of health concern, since they are found ubiquitously in the environment and in food items. We investigated in vitro effects on estrogen receptor (ER) and androgen receptor (AR) transactivity, and aromatase enzyme activity, of the following pesticides: 2-methyl-4-chlorophenoxyacetic acid (MCPA), terbuthylazine, iodosulfuron-methyl-sodium, mesosulfuron-methyl, metsulfuron-methyl, chlormequat chloride, bitertanol, propiconazole, prothioconazole, mancozeb, cypermethrin, tau fluvalinate, malathion and the metabolite ethylene thiourea (ETU). The pesticides were analyzed alone and in selected mixtures. Effects of the pesticides on ER and AR function were assessed in human breast carcinoma MVLN cells and hamster ovary CHO-K1 cells, respectively, using luciferase reporter gene assays. Effects on aromatase enzyme activity were analyzed in human choriocarcinoma JEG-3 cells, employing the classical [(3)H](2)O method. Five pesticides (terbuthylazine, propiconazole, prothioconazole, cypermethrin and malathion) weakly induced the ER transactivity, and three pesticides (bitertanol, propiconazole and mancozeb) antagonized the AR activity in a concentration-dependent manner. Three pesticides (terbuthylazine, propiconazole and prothioconazole) weakly induced the aromatase activity. In addition, two mixtures, consisting of three pesticides (bitertanol, propiconazole, cypermethrin) and five pesticides (terbuthylazine, bitertanol, propiconazole, cypermethrin, malathion), respectively, induced the ER transactivity and aromatase activity, and additively antagonized the AR transactivity. In conclusion, our data suggest that currently used pesticides possess endocrine-disrupting potential in vitro which can be mediated via ER, AR and aromatase activities. The observed mixture effects emphasize the importance of considering the combined action of pesticides in order to assure proper estimations of related health effect risks.

  18. CREB-regulated transcription co-activator family stimulates promoter II-driven aromatase expression in preadipocytes.

    Science.gov (United States)

    Samarajeewa, Nirukshi U; Docanto, Maria M; Simpson, Evan R; Brown, Kristy A

    2013-08-01

    The dramatically increased prevalence of breast cancer after menopause is of great concern and is correlated with elevated local levels of estrogens. This is mainly due to an increase in aromatase expression driven by its proximal promoter II (PII). We have previously demonstrated that the CREB co-activator CRTC2 binds directly to PII and stimulates its activity via mechanisms involving LKB1-AMPK in response to prostaglandin E(2) (PGE(2)). There are three members of the CRTC family (CRTC1-3) and this study aimed to characterize the role of other CRTCs in the activation of aromatase PII. The expression and subcellular localization of CRTCs were examined in preadipocytes using qPCR and immunofluorescence. Under basal conditions, CRTC1 expression was the lowest, whereas CRTC3 transcripts were present at higher levels. Basally, CRTC2 and CRTC3 were mainly cytoplasmic and PGE(2) caused their nuclear translocation. Reporter assays and chromatin immunoprecipitation (ChIP) were performed to assess the effect of CRTCs on PII activity and binding. Basal PII activity was significantly increased with all CRTCs. Forskolin (FSK)/phorbol 12-myristate 13-acetate (PMA), to mimic PGE(2), resulted in a further significant increase in PII activity with all CRTCs, with CRTC2 and CRTC3 having greater effects. This was consistent with ChIP data showing an increased binding of CRTCs to PII with FSK/PMA. Moreover, gene silencing of CRTC2 and CRTC3 significantly reduced the FSK/PMA-mediated stimulation of aromatase activity. Interestingly, CRTCs acted cooperatively with CREB1 to increase PII activity, and both CREs were found to be essential for the maximal induction of PII activity by CRTCs. Phosphorylation of CRTC2 at its AMPK target site, Ser 171, dictated its subcellular localization, and the activation of aromatase PII in preadipocytes. In conclusion, this study demonstrates that aromatase regulation in primary human breast preadipocytes involves more than one CRTC.

  19. Phospholemman-dependent regulation of the cardiac Na/K-ATPase activity is modulated by inhibitor-1 sensitive type-1 phosphatase.

    Science.gov (United States)

    El-Armouche, Ali; Wittköpper, Katrin; Fuller, William; Howie, Jacqueline; Shattock, Michael J; Pavlovic, Davor

    2011-12-01

    Cardiac Na/K-ATPase (NKA) is regulated by its accessory protein phospholemman (PLM). Whereas kinase-induced PLM phosphorylation has been shown to mediate NKA stimulation, the role of endogenous phosphatases is presently unknown. We investigated the role of protein phosphatase-1 (PP-1) on PLM phosphorylation and NKA activity in rat cardiomyocytes and failing human hearts. Incubation of rat cardiomyocytes with the chemical PP-1/PP-2A inhibitor okadaic acid or the specific PP-1-inhibitor peptide (I-1ct) identified PLM phosphorylation at Ser-68 as the main substrate for PP-1. Moreover, myocytes adenovirally overexpressing PP-1 inhibitor-1 protein (I-1,Ad-I-1/eGFP) showed a 70% increase in PLM Ser-68 phosphorylation and 65% increase in NKA current, compared with enhanced green fluorescence protein (eGFP)-infected controls (Ad-eGFP), using Western blotting and voltage clamping, respectively. Notably, in left ventricular myocardium from patients with heart failure, PLM Ser-68 phosphorylation was ≈ 50% lower (n=7) than in nonfailing controls (n=7). We provide the first physiological and biochemical evidence that PLM phosphorylation and cardiac Na/K-ATPase activity are negatively regulated by PP-1 and that this regulatory mechanism could be counteracted by I-1. This novel mechanism is markedly perturbed in failing hearts favoring PLM dephosphorylation and NKA deactivation and thus may contribute to maladaptive hypertrophy and arrhythmogenesis via chronically higher intracellular Na and Ca concentrations.

  20. Acute and chronic treatment with selective serotonin uptake inhibitors in mice: effects on nociceptive sensitivity and response to 5-methoxy-N,N-dimethyltryptamine.

    Science.gov (United States)

    Eide, P K; Hole, K

    1988-03-01

    The tail-flick and increasing temperature hot-plate tests were employed to study the effects of acute or chronic treatment with zimelidine, alaproclate or chlorimipramine on nociception and response to 5-methoxy-N,N-dimethyltryptamine (5-MeODMT) in mice. A single dose of the serotonin (5-HT) uptake inhibitors produced antinociception in the hot-plate test but not in the tail-flick test. After chronic administration, reduced tail-flick latencies were demonstrated 24, 48, 72 and 144 h after withdrawal of zimelidine treatment, 48 h after withdrawal of alaproclate and 48 and 96 h after withdrawal of chlorimipramine treatment. The hot-plate response temperatures were slightly lowered after chronic zimelidine treatment but not after treatment with alaproclate or chlorimipramine. The response to 5-MeODMT was not altered by a single dose of the 5-HT uptake inhibitors, however, after withdrawal of chronic treatment this response was increased in the tail-flick test but not in the hot-plate test. It was concluded that acute and chronic treatment with 5-HT uptake inhibitors modulate nociception differently, and that chronic treatment induces supersensitivity of spinal postsynaptic 5-HT receptors. Different modulation of different 5-HT receptor subpopulations by these compounds may possibly contribute to the test-dependent results. PMID:2966334

  1. The interaction between aromatase, metalloproteinase 2,9 and cd44 in breast cancer A interação entre aromatase, metalloproteinase 2, 9 e cd44 no câncer de mama

    Directory of Open Access Journals (Sweden)

    Fábio Bagnoli

    2010-01-01

    Full Text Available OBJECTIVE: This study intends to verify the expression levels and correlation of aromatase, matrix metalloproteinase 2 (MMP-2, matrix metalloproteinase 9 (MMP-9 and CD44 in ductal carcinoma in situ (DCIS and infiltrating ductal carcinoma (IDC when both are found in the same breast. METHODS: One hundred and ten cases were evaluated by tissue microarray (TMA and immunohistochemically screened with anti-aromatase polyclonal antibodies, anti-MMP-2 monoclonal antibodies, anti-MMP-9 policlonal antibodies and anti-CD44 monoclonal antibodies. RESULTS: Aromatase was expressed in IDC and DCIS in 63 (57.3% and 60 (67% of the cases respectively; MMP-2 was similarly expressed in IDC and DCIS in 15 (13.60% cases; MMP-9 was positively expressed in IDC and DCIS in 83 (75.50% and 82 (74.50% cases, respectively; CD44 was positively expressed in IDC and DCIS in 49 (44.50% and 48 (42.60% of the cases, respectively; all of them were highly correlated (pOBJETIVO: O objetivo desse estudo é verificar as expressões e correlações da aromatase, metalloproteinase 2 da matriz (MMP2, metalloproteinase 9 da matriz (MMP-9 e CD44 no carcinoma ductal in situ (CDIS e carcinoma ductal infiltrativo (CDI quando ambos estão presentes simultaneamente na mesma mama. MÉTODOS: Foram avaliados 110 casos pelo método de tissue microarray (TMA e através da utilização de anticorpos policlonais antiaromatase, anticorpos monoclonais anti-MMP-2, anticorpos policlonais anti-MMP-9 e anticorpos monoclonais anti-CD44. RESULTADOS: A aromatase estava expressa de forma positiva no CDI e CDIS em 63 (57,3% e 60 (67% casos, respectivamente. A expressão de MMP-2 estava expressa de forma positiva em 15 (13,6% casos tanto no CDI, quanto no CDIS. A expressão da MMP-9 estava expressa de forma positiva em 83 (75,5% e 82 (74,5% casos de CDI e CDIS, respectivamente. A expressão de CD44 estava expressa de forma positiva em 49 (44,5% e 48 (42,6% casos de CDI e CDIS, respectivamente. Todos eles

  2. Monitoring of epidermal growth factor receptor tyrosine kinase inhibitor-sensitizing and resistance mutations in the plasma DNA of patients with advanced non-small cell lung cancer during treatment with erlotinib

    DEFF Research Database (Denmark)

    Sorensen, Boe S; Wu, Lin; Wei, Wen;

    2014-01-01

    BACKGROUND: The feasibility of monitoring epidermal growth factor receptor (EGFR) mutations in plasma DNA from patients with advanced non-small cell lung cancer (NSCLC) during treatment with erlotinib and its relation to disease progression was investigated. METHODS: The amount of EGFR-mutant DNA...... was tested in plasma DNA from patients with advanced NSCLC with allele-specific polymerase chain reaction assays. Blood samples from 23 patients with adenocarcinoma of NSCLC that carried tyrosine kinase inhibitor-sensitizing EGFR mutations were taken immediately before treatment with erlotinib. Additional...... blood samples were taken at timed intervals until erlotinib treatment was withdrawn. RESULTS: The amount of plasma DNA with sensitizing EGFR mutations was found to be reduced after the first cycle of erlotinib treatment in 22 of 23 patients (96%). No patients presented with the resistant T790M mutation...

  3. Disruption of IκB Kinase (IKK)-mediated RelA Serine 536 Phosphorylation Sensitizes Human Multiple Myeloma Cells to Histone Deacetylase (HDAC) Inhibitors*

    OpenAIRE

    Dai, Yun; Chen, Shuang; Wang, Li; Pei, Xin-Yan; Funk, Vanessa L.; Kramer, Lora B.; Dent, Paul; Grant, Steven

    2011-01-01

    Post-translational modifications of RelA play an important role in regulation of NF-κB activation. We previously demonstrated that in malignant hematopoietic cells, histone deacetylase inhibitors (HDACIs) induced RelA hyperacetylation and NF-κB activation, attenuating lethality. We now present evidence that IκB kinase (IKK) β-mediated RelA Ser-536 phosphorylation plays a significant functional role in promoting RelA acetylation, inducing NF-κB activation, and limiting HDACI lethality in human...

  4. New insights about the evaluation of human sperm quality: the aromatase example.

    Directory of Open Access Journals (Sweden)

    A Saad

    2010-01-01

    Full Text Available Male contribution to the couple's infertility is at first evaluated by the routine examination of semen parameters upon optical microscopy providing valuable information for a rational initial diagnosis and for a clinical management of infertility. But the different forms of infertility defined according to the WHO criteria especially teratozoospermia are not always related to the chromatin structure or to the fertilization capacity. New investigations at the molecular level (transcript and protein could be developed in order to understand the nature of sperm malformation responsible of human infertility and thus to evaluate the sperm quality. The profile analysis of spermatozoal transcripts could be considered as a fingerprint of the past spermatogenic events. The selection of representative transcripts of normal spermatozoa remains complex because a differential expression (increased, decreased or not modified levels of specific transcripts has been revealed between immotile and motile sperm fractions issued from normozoospermic donors. Microarrays tests or real-time quantitative PCR could be helpful for the identification of factors involved in the male infertility. Differences in the expression of specific transcripts have been reported between normal and abnormal semen samples. With the aromatase example, we have noted a negative strong correlation between the amount of transcript and the percentage of abnormal forms especially in presence of head defects. Immunocytochemical procedures using fluorescent probes associated with either confocal microscopy or flow cytometry can be also helpful to proceed with further investigations about the localization of proteins in the compartmentalized spermatozoa or the acrosome reaction. The dual location of aromatase both in the equatorial segment, the mid-piece and the tail could explain the double role of this enzyme in acrosome reaction and motility.

  5. Frequency of Polymorphism in Aromatase Enzyme Coding Gene with Prostate Cancer Risk in North Indian Population

    Directory of Open Access Journals (Sweden)

    KH Onsory

    2015-10-01

    Full Text Available Background: A series of biochemical reactions are involved in the endogenous production of estrogens. Their final and rate-limiting step is catalyzed by aromatase belonging to the class XIX of cytochrome P450. CYP19 is a key enzyme for estrogen synthesis in males. It catalyzes the irreversible conversion of androstenedione and testosterone to estrone and estradiol-17β, respectively. Aromatase P450 is present in the endoplasmic reticulum of estrogen-reproducing cells in which it is expressed. The effects of the resulting estrogens are mediated through the estrogen receptor. One of the most important polymorphism, is a C to T variation in exon 7 resulting in an Arg264Cys amino acid exchange, has been shown to be very common in Asia. The purpose of this study was to determine the association of CYP19 gene polymorphism with the prostate cancer risk among the studied population. Methods: PCR-RFLP analysis of CYP19 gene was on 100 prostate cancer patients and an equal number of matching controls. The data was analyzed using the computer software SPSS for windows (version 19. Results: The frequency of CT genotype was higher in patients (37% as compared to controls (21.2% and this incidence was statistically significant (OR, 2.10; 95 % CI, 1.02-4.34; P=0.044. Stratification of patients according to the risk factors, resulted in a slightly improved OR in individuals carrying CT compared to CC genotype (OR, 2.35 95% CI, 1.11-4.96; P=0.024. The TT genotype was not significantly associated with prostate cancer risk (OR, 0.63; 95% CI, 0.16-2.50; P=0.519. Conclusion: It seems that CT genotype is more associated with cancer prostate compare with other genotypes. It appears to be an increased risk of prostate cancer associated with the Arg264Cys substitution in the CYP19 gene.

  6. Characterization of Aromatase Expression in the Adult Male and Female Mouse Brain. I. Coexistence with Oestrogen Receptors α and β, and Androgen Receptors

    OpenAIRE

    Davor Stanić; Sydney Dubois; Hui Kheng Chua; Bruce Tonge; Nicole Rinehart; Malcolm K Horne; Wah Chin Boon

    2014-01-01

    Aromatase catalyses the last step of oestrogen synthesis. There is growing evidence that local oestrogens influence many brain regions to modulate brain development and behaviour. We examined, by immunohistochemistry, the expression of aromatase in the adult male and female mouse brain, using mice in which enhanced green fluorescent protein (EGFP) is transcribed following the physiological activation of the Cyp19A1 gene. EGFP-immunoreactive processes were distributed in many brain regions, in...

  7. A novel autophagy/mitophagy inhibitor liensinine sensitizes breast cancer cells to chemotherapy through DNM1L-mediated mitochondrial fission.

    Science.gov (United States)

    Zhou, Jing; Li, Guobing; Zheng, Yi; Shen, Han-Ming; Hu, Xiaoye; Ming, Qian-Liang; Huang, Cheng; Li, Peng; Gao, Ning

    2015-01-01

    Autophagy inhibition has been widely accepted as a promising therapeutic strategy in cancer, while the lack of effective and specific autophagy inhibitors hinders its application. Here we found that liensinine, a major isoquinoline alkaloid, inhibits late-stage autophagy/mitophagy through blocking autophagosome-lysosome fusion. This effect is likely achieved via inhibiting the recruitment of RAB7A to lysosomes but not to autophagosomes. We further investigated the effects of autophagy inhibition by liensinine on the therapeutic efficacy of chemotherapeutic drugs and found that cotreatment of liensinine markedly decreased the viability and increased apoptosis in breast cancer cells treated with various chemotherapeutic agents. Mechanistically, we found that inhibition of autophagy/mitophagy by liensinine enhanced doxorubicin-mediated apoptosis by triggering mitochondrial fission, which resulted from dephosphorylation and mitochondrial translocation of DNM1L. However, blocking autophagosome/mitophagosome formation by pharmacological or genetic approaches markedly attenuated mitochondrial fission and apoptosis in cells with combinatatorial treatment. Moreover, liensinine was synergized with doxorubicin to inhibit tumor growth in MDA-MB-231 xenograft in vivo. Our findings suggest that liensinine could potentially be further developed as a novel autophagy/mitophagy inhibitor, and a combination of liensinine with classical chemotherapeutic drugs could represent a novel therapeutic strategy for treatment of breast cancer.

  8. A dual mTORC1 and mTORC2 inhibitor shows antitumor activity in esophageal squamous cell carcinoma cells and sensitizes them to cisplatin.

    Science.gov (United States)

    Huang, Yu; Xi, Qingsong; Chen, Yu; Wang, Jing; Peng, Ping; Xia, Shu; Yu, Shiying

    2013-10-01

    The mammalian target of rapamycin (mTOR) signaling pathway is critical for the growth and proliferation of various malignant tumors, including esophageal squamous cell carcinoma (ESCC). Therefore, targeting of mTOR protein is a promising strategy for therapy in this disease. In the present study, we examined the antitumor effects of a specific mTOR kinase inhibitor, PP242, which blocks both mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2) pathways, in two ESCC cell lines: Eca-109 and TE-1. We showed that PP242, but not rapamycin, attenuated the activities of both mTORC1 and mTORC2 signaling in ESCC. PP242 inhibited 4E-binding protein-1 phosphorylation and abrogated mTORC1-dependent PI3K/Akt feedback activation. Significantly, PP242 effectively suppressed ESCC cell proliferation, induced apoptosis, and arrested the cell cycle. Furthermore, PP242 promoted cisplatin-induced apoptosis and enhanced the antitumor efficacy of cisplatin in ESCC cells, which was likely to be associated with inhibition of Akt activity. Our results show that simultaneous targeting of both mTORC1 and mTORC2 pathways leads to effective antitumor actions in ESCC, and strongly suggest that dual mTORC1/2 inhibitors should be developed as potential agents for the treatment of ESCC.

  9. HDAC Inhibitors.

    Science.gov (United States)

    Olzscha, Heidi; Bekheet, Mina E; Sheikh, Semira; La Thangue, Nicholas B

    2016-01-01

    Lysine acetylation in proteins is one of the most abundant posttranslational modifications in eukaryotic cells. The dynamic homeostasis of lysine acetylation and deacetylation is dictated by the action of histone acetyltransferases (HAT) and histone deacetylases (HDAC). Important substrates for HATs and HDACs are histones, where lysine acetylation generally leads to an open and transcriptionally active chromatin conformation. Histone deacetylation forces the compaction of the chromatin with subsequent inhibition of transcription and reduced gene expression. Unbalanced HAT and HDAC activity, and therefore aberrant histone acetylation, has been shown to be involved in tumorigenesis and progression of malignancy in different types of cancer. Therefore, the development of HDAC inhibitors (HDIs) as therapeutic agents against cancer is of great interest. However, treatment with HDIs can also affect the acetylation status of many other non-histone proteins which play a role in different pathways including angiogenesis, cell cycle progression, autophagy and apoptosis. These effects have led HDIs to become anticancer agents, which can initiate apoptosis in tumor cells. Hematological malignancies in particular are responsive to HDIs, and four HDIs have already been approved as anticancer agents. There is a strong interest in finding adequate biomarkers to predict the response to HDI treatment. This chapter provides information on how to assess HDAC activity in vitro and determine the potency of HDIs on different HDACs. It also gives information on how to analyze cellular markers following HDI treatment and to analyze tissue biopsies from HDI-treated patients. Finally, a protocol is provided on how to detect HDI sensitivity determinants in human cells, based on a pRetroSuper shRNA screen upon HDI treatment. PMID:27246222

  10. Impact of the putative cancer stem cell markers and growth factor receptor expression on the sensitivity of ovarian cancer cells to treatment with various forms of small molecule tyrosine kinase inhibitors and cytotoxic drugs

    Science.gov (United States)

    Puvanenthiran, Soozana; Essapen, Sharadah; Seddon, Alan M.; Modjtahedi, Helmout

    2016-01-01

    Increased expression and activation of human epidermal growth factor receptor (EGFR) and HER-2 have been reported in numerous cancers. The aim of this study was to determine the sensitivity of a large panel of human ovarian cancer cell lines (OCCLs) to treatment with various forms of small molecule tyrosine kinase inhibitors (TKIs) and cytotoxic drugs. The aim was to see if there was any association between the protein expression of various biomarkers including three putative ovarian cancer stem cell (CSC) markers (CD24, CD44, CD117/c-Kit), P-glycoprotein (P-gp), and HER family members and response to treatment with these agents. The sensitivity of 10 ovarian tumour cell lines to the treatment with various forms of HER TKIs (gefitinib, erlotinib, lapatinib, sapitinib, afatinib, canertinib, neratinib), as well as other TKIs (dasatinib, imatinib, NVP-AEW541, crizotinib) and cytotoxic agents (paclitaxel, cisplatin and doxorubicin), as single agents or in combination, was determined by SRB assay. The effect on these agents on the cell cycle distribution, and downstream signaling molecules and tumour migration were determined using flow cytometry, western blotting, and the IncuCyte Clear View cell migration assay respectively. Of the HER inhibitors, the irreversible pan-TKIs (canertinib, neratinib and afatinib) were the most effective TKIs for inhibiting the growth of all ovarian cancer cells, and for blocking the phosphorylation of EGFR, HER-2, AKT and MAPK in SKOV3 cells. Interestingly, while the majority of cancer cells were highly sensitive to treatment with dasatinib, they were relatively resistant to treatment with imatinib (i.e., IC50 >10 μM). Of the cytotoxic agents, paclitaxel was the most effective for inhibiting the growth of OCCLs, and of various combinations of these drugs, only treatment with a combination of NVP-AEW541 and paclitaxel produced a synergistic or additive anti-proliferative effect in all three cell lines examined (i.e., SKOV3, Caov3, ES2

  11. Farnesoid X Receptor, through the Binding with Steroidogenic Factor 1-responsive Element, Inhibits Aromatase Expression in Tumor Leydig Cells*

    OpenAIRE

    Catalano, Stefania; Malivindi, Rocco; Giordano, Cinzia; Gu, Guowei; Panza, Salvatore; Bonofiglio, Daniela; Lanzino, Marilena; Sisci, Diego; Panno, Maria Luisa; Andò, Sebastiano

    2009-01-01

    The farnesoid X receptor (FXR) is a member of the nuclear receptor superfamily that regulates bile acid homeostasis. It is expressed in the liver and the gastrointestinal tract, but also in several non-enterohepatic tissues including testis. Recently, FXR was identified as a negative modulator of the androgen-estrogen-converting aromatase enzyme in human breast cancer cells. In the present study we detected the expression of FXR in Leydig normal and tumor cell lines and in rat testes tissue. ...

  12. Brain aromatase and circulating corticosterone are rapidly regulated by combined acute stress and sexual interaction in a sex specific manner

    OpenAIRE

    Dickens, M.J.; Balthazart, J.; Cornil, C. A.

    2012-01-01

    Neural production of 17β-oestradiol via aromatisation of testosterone may play a critical role in rapid, non-genomic regulation of physiological and behavioural processes. In brain nuclei implicated in the control of sexual behaviour, sexual or stressfull stimuli induce respectively a rapid inhibition or increase in preoptic aromatase activity (AA). Here, we tested quail that were either non-stressed or acutely stressed (15 min restraint) immediately prior to sexual interaction (5 min) with s...

  13. Dietary Polyphenols Suppress Elevated Levels of Proinflammatory Mediators and Aromatase in the Mammary Gland of Obese Mice

    OpenAIRE

    Subbaramaiah, Kotha; Sue, Erika; Bhardwaj, Priya; Du, Baoheng; Hudis, Clifford A.; Giri, Dilip; Kopelovich, Levy; Zhou, Xi Kathy; Dannenberg, Andrew J.

    2013-01-01

    In postmenopausal women, obesity is a risk factor for the development of hormone receptor-positive breast cancer driven by estrogen. After menopause, aromatization of androgen precursors in adipose tissue is a major synthetic source of estrogen. Recently, in mouse models and women, we identified an obesity-inflammation-aromatase axis. This obesity induced inflammation is characterized by crown-like structures (CLS) consisting of dead adipocytes encircled by macrophages in breast white adipose...

  14. Mitochondrial inhibitor sensitizes non-small-cell lung carcinoma cells to TRAIL-induced apoptosis by reactive oxygen species and Bcl-X(L)/p53-mediated amplification mechanisms.

    Science.gov (United States)

    Shi, Y L; Feng, S; Chen, W; Hua, Z C; Bian, J J; Yin, W

    2014-12-18

    Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a promising agent for anticancer therapy; however, non-small-cell lung carcinoma (NSCLC) cells are relatively TRAIL resistant. Identification of small molecules that can restore NSCLC susceptibility to TRAIL-induced apoptosis is meaningful. We found here that rotenone, as a mitochondrial respiration inhibitor, preferentially increased NSCLC cells sensitivity to TRAIL-mediated apoptosis at subtoxic concentrations, the mechanisms by which were accounted by the upregulation of death receptors and the downregulation of c-FLIP (cellular FLICE-like inhibitory protein). Further analysis revealed that death receptors expression by rotenone was regulated by p53, whereas c-FLIP downregulation was blocked by Bcl-X(L) overexpression. Rotenone triggered the mitochondria-derived reactive oxygen species (ROS) generation, which subsequently led to Bcl-X(L) downregulation and PUMA upregulation. As PUMA expression was regulated by p53, the PUMA, Bcl-X(L) and p53 in rotenone-treated cells form a positive feedback amplification loop to increase the apoptosis sensitivity. Mitochondria-derived ROS, however, promote the formation of this amplification loop. Collectively, we concluded that ROS generation, Bcl-X(L) and p53-mediated amplification mechanisms had an important role in the sensitization of NSCLC cells to TRAIL-mediated apoptosis by rotenone. The combined TRAIL and rotenone treatment may be appreciated as a useful approach for the therapy of NSCLC that warrants further investigation.

  15. Identification of cyclohexanone derivatives that act as catalytic inhibitors of topoisomerase I: effects on tamoxifen-resistant MCF-7 cancer cells.

    Science.gov (United States)

    Leung, Euphemia; Rewcastle, Gordon W; Joseph, Wayne R; Rosengren, Rhonda J; Larsen, Lesley; Baguley, Bruce C

    2012-12-01

    Breast cancer is commonly treated with anti-estrogens or aromatase inhibitors, but resistant disease eventually develops and new therapies for such resistance are of great interest. We have previously isolated several tamoxifen-resistant variant sub-lines of the MCF-7 breast cancer cell line and provided evidence that they arose from expansion of pre-existing minor populations. We have searched for therapeutic agents that exhibit selective growth inhibition of the resistant lines and here investigate 2,6-bis(pyridin-3-ylmethylene)-cyclohexanone (RL90) and 2,6-bis(pyridin-4-ylmethylene)-cyclohexanone (RL91). We found that two of the tamoxifen-resistant sub-lines (TamR3 and TamC3) unexpectedly showed increased sensitivity to RL90 and RL91. We utilized growth inhibition assays, flow cytometry and immunoblotting to establish a mechanistic basis for their action. Treated sensitive cells showed S-phase selective DNA damage, as detected by histone H2AX phosphorylation. Cellular responses were similar to those induced by the topoisomerase I poison camptothecin. Although IC(50) values of camptothecin, RL90, RL91 were correlated, studies with purified mammalian topoisomerase I suggested that RL90 and RL91 differed from camptothecin by acting as catalytic topoisomerase I inhibitors. These drugs provide a platform for the further development of DNA damaging drugs that have selective effects on tamoxifen resistant breast cancer cells. The results also raise the question of whether clinical topoisomerase I poisons such as irinotecan and topotecan might be active in the treatment of some types of tamoxifen-resistant cancer.

  16. 4-Phenylureido/thioureido-substituted 2,2-dimethylchroman analogs of cromakalim bearing a bulky 'carbamate' moiety at the 6-position as potent inhibitors of glucose-sensitive insulin secretion.

    Science.gov (United States)

    Pirotte, Bernard; Florence, Xavier; Goffin, Eric; Medeiros, Marlen Borges; de Tullio, Pascal; Lebrun, Philippe

    2016-10-01

    The synthesis of 2,2-dimethylchromans bearing a 3/4-chloro/cyano-substituted phenylureido or phenylthioureido moiety at the 4-position and an alkoxycarbonylamino ('carbamate') group at the 6-position is described. These new analogs of the potassium channel opener (±)-cromakalim were further tested on rat pancreatic islets as putative inhibitors of insulin release and on rat aorta rings as putative vasorelaxants. All compounds inhibited insulin secretion and induced a myorelaxant activity. Compound 14o [R/S-N-3-cyanophenyl-N'-(6-tert-butoxycarbonylamino-3,4-dihydro-2,2-dimethyl-2H-1-benzopyran-4-yl)urea; BPDZ 711] emerged as the most potent inhibitor of the glucose-sensitive insulin releasing process (IC50 = 0.24 μM) and displayed selectivity towards the pancreatic endocrine tissue. Radioisotopic, fluorimetric and pharmacological investigations were performed on rat pancreatic islet and rat vascular smooth muscle cells in order to decipher its mechanism of action. Our findings suggest that the mechanism of action of 14o is rather unspecific. The compound behaves as a KATP channel opener, a Ca(2+) entry blocker, and promotes an intracellular calcium translocation. PMID:27267004

  17. Ultra-high sensitivity analysis of estrogens for special populations in serum and plasma by liquid chromatography-mass spectrometry: Assay considerations and suggested practices.

    Science.gov (United States)

    Wang, Qingqing; Mesaros, Clementina; Blair, Ian A

    2016-09-01

    Estrogen measurements play an important role in the clinical evaluation of many endocrine disorders as well as in research on the role of hormones in human biology and disease. It remains an analytical challenge to quantify estrogens and their metabolites in specimens from special populations including older men, children, postmenopausal women and women receiving aromatase inhibitors. Historically, immunoassays have been used for measuring estrogens and their metabolites in biological samples for risk assessment. However, the lack of specificity and accuracy of immunoassay-based methods has caused significant problems when interpreting data generated from epidemiological studies and across different laboratories. Stable isotope dilution (SID) methodology coupled with liquid chromatography-selected reaction monitoring-mass spectrometry (LC-SRM/MS) is now accepted as the 'gold-standard' to quantify estrogens and their metabolites in serum and plasma due to improved specificity, high accuracy, and the ability to monitor multiple estrogens when compared with immunoassays. Ultra-high sensitivity can be obtained with pre-ionized derivatives when using triple quadruple mass spectrometers in the selected reaction monitoring (SRM) mode coupled with nanoflow LC. In this review, we have examined the special issues related to utilizing ultra-high sensitivity SID LC-SRM/MS-based methodology to accurately quantify estrogens and their metabolites in the serum and plasma from populations with low estrogen levels. The major issues that are discussed include: sample preparation for both unconjugated and conjugated estrogens, derivatization, chromatographic separation, matrix effects, and assay validation. PMID:26767303

  18. Enhancement of Radiation Sensitivity in Lung Cancer Cells by a Novel Small Molecule Inhibitor That Targets the β-Catenin/Tcf4 Interaction.

    Science.gov (United States)

    Zhang, Qinghao; Gao, Mei; Luo, Guifen; Han, Xiaofeng; Bao, Wenjing; Cheng, Yanyan; Tian, Wang; Yan, Maocai; Yang, Guanlin; An, Jing

    2016-01-01

    Radiation therapy is an important treatment choice for unresectable advanced human lung cancers, and a critical adjuvant treatment for surgery. However, radiation as a lung cancer treatment remains far from satisfactory due to problems associated with radiation resistance in cancer cells and severe cytotoxicity to non-cancer cells, which arise at doses typically administered to patients. We have recently identified a promising novel inhibitor of β-catenin/Tcf4 interaction, named BC-23 (C21H14ClN3O4S), which acts as a potent cell death enhancer when used in combination with radiation. Sequential exposure of human p53-null non-small cell lung cancer (NSCLC) H1299 cells to low doses of x-ray radiation, followed 1 hour later by administration of minimally cytotoxic concentrations of BC-23, resulted in a highly synergistic induction of clonogenic cell death (combination index radiation effectiveness mediated by BC-23. BC-23 therefore represents a promising new class of radiation enhancer.

  19. Regional selectivity of a gamma-aminobutyric acid-induced (/sup 3/H)acetylcholine release sensitive to inhibitors of gamma-aminobutyric acid uptake

    Energy Technology Data Exchange (ETDEWEB)

    Bonanno, G.; Raiteri, M.

    1987-05-01

    The effects of gamma-aminobutyric acid (GABA) on the release of (/sup 3/H)acetylcholine ((/sup 3/H)ACh) were studied in synaptosomes prepared from rat hippocampus, cerebral cortex, hypothalamus, and striatum and prelabelled with (/sup 3/H)choline. When synaptosomes were exposed in superfusion to exogenous GABA (0.01-0.3 mM) the basal release of newly synthesized (/sup 3/H)ACh was increased in a concentration-dependent way in hippocampus, cortex, and hypothalamus nerve endings. In contrast, the release of (/sup 3/H)ACh was not significantly affected by GABA in striatal synaptosomes. The effect of GABA was not antagonized significantly by bicuculline or picrotoxin. Muscimol caused only a slight not significant increase of (/sup 3/H)ACh release when tested at 0.3 mM whereas, at this concentration, (-)-baclofen was totally inactive. The GABA-induced release of (/sup 3/H)ACh was counteracted by SKF 89976A, SKF 100561, and SKF 100330A, three strong and selective GABA uptake inhibitors. The data suggest that, in selective areas of the rat brain, GABA causes release of (/sup 3/H)ACh following penetration into cholinergic nerve terminals through a GABA transport system.

  20. The proteasome inhibitor MG-132 sensitizes PC-3 prostate cancer cells to ionizing radiation by a DNA-PK-independent mechanism

    Directory of Open Access Journals (Sweden)

    McBride William H

    2005-07-01

    Full Text Available Abstract Background By modulating the expression levels of specific signal transduction molecules, the 26S proteasome plays a central role in determining cell cycle progression or arrest and cell survival or death in response to stress stimuli, including ionizing radiation. Inhibition of proteasome function by specific drugs results in cell cycle arrest, apoptosis and radiosensitization of many cancer cell lines. This study investigates whether there is also a concomitant increase in cellular radiosensitivity if proteasome inhibition occurs only transiently before radiation. Further, since proteasome inhibition has been shown to activate caspase-3, which is involved in apoptosis, and caspase-3 can cleave DNA-PKcs, which is involved in DNA-double strand repair, the hypothesis was tested that caspase-3 activation was essential for both apoptosis and radiosensitization following proteasome inhibition. Methods Prostate carcinoma PC-3 cells were treated with the reversible proteasome inhibitor MG-132. Cell cycle distribution, apoptosis, caspase-3 activity, DNA-PKcs protein levels and DNA-PK activity were monitored. Radiosensitivity was assessed using a clonogenic assay. Results Inhibition of proteasome function caused cell cycle arrest and apoptosis but this did not involve early activation of caspase-3. Short-time inhibition of proteasome function also caused radiosensitization but this did not involve a decrease in DNA-PKcs protein levels or DNA-PK activity. Conclusion We conclude that caspase-dependent cleavage of DNA-PKcs during apoptosis does not contribute to the radiosensitizing effects of MG-132.

  1. Membrane bound pyrophosphatase and P-type adenosine triphosphatase of Leishmania donovani as possible chemotherapeutic targets: similarities and differences in inhibitor sensitivities.

    Science.gov (United States)

    Sen, S S; Bhuyan, N R; Lakshman, K; Roy, A K; Chakraborty, B; Bera, T

    2009-12-01

    The activities of inorganic pyrophosphatase (PPase) and adenosine triphosphatase (ATPase) were studied in the plasma membrane of Leishmania donovani promastigotes and amastigotes. It was shown that the specific activity of PPase was greater than that of ATPase in the promastigote plasma membrane. We characterized H+-PPase present in the plasma membrane of L. donovani and investigated its possible role in the survival of promastigote and amastigote. PPase activity was stimulated by K+ and sodium orthovanadate and inhibited by pyrophosphate analogs (imidodiphosphate and alendronate), KF, N,N'-dicyclohexylcarbodiimide (DCCD), thiol reagents (p-chloromercuribenzenesulfonate (PCMBS), N-ethylmaleimide (NEM), and phenylarsine oxide (PAO)), the ABC superfamily transport modulator verapamil, and also by the F(1)F(o)-ATPase inhibitor quercetin. ATPase activity was stimulated by K+ and verapamil, inhibited by DCCD, PCMBS, NEM, sodium azide, sodium orthovanadate, and quercetin, and was unaffected by PAO. We conclude that there are significant differences within promastigote, amastigote, and mammalian host in cytosolic pH homeostasis to merit the inclusion of PPase transporter as a putative target for rational drug design. PMID:19961421

  2. 泵抑制剂提高肺炎克雷伯菌对环丙沙星的敏感性%Efflux pump Inhibitors improve the sensitivity of ciprofloxacin in drug-resistance Klebsiella pneumoniae

    Institute of Scientific and Technical Information of China (English)

    王若伦; 叶晓光

    2007-01-01

    目的 研究泵抑制剂利血平和羰基氰氯苯腙(CCCP)能否提高肺炎克雷伯菌对环丙沙星的敏感性.方法 收集临床分离对环丙沙星敏感的肺炎克雷伯菌20株,随机抽取10株,应用不同浓度梯度环丙沙星逐级诱导为高耐药株.用琼脂稀释法测定应用泵抑制剂前后,分离的临床敏感株和诱导耐药株的最小抑菌浓度(MIC).结果 应用泵抑制剂利血平和CCCP后,分别有6株(60%)和8株(80%)诱导耐药株的MIC值有所下降,泵阳性株分别有4株和7株.结论 起始低浓度后梯度环丙沙星可以人工诱导出肺炎克雷伯菌高度耐药株.泵抑制剂利血平和CCCP能提高耐药肺炎克雷伯菌对环丙沙星的敏感性.%Objective To explore whether efflux pump inhibitors can improve the sensitivity of ciprofloxacin in drug-resislance Klebsilla pneumoniae. Methods Twenty sensitive strains of Klebsiella pneumoniae were isolated from patients. Ten strains were induced by concentration gradient ciprofloxacin and changed into ciprofloxacin-high resistant Klebsiella pneumoniae. The MICs of ciprofloxacin in the absence or presence of reserpine or carbonyl cyanide m-chlorophenyl hydrazone(CCCP) were detected by agar dilution method. Results After treated with efflux pump inhibitor, the MICs of most induced-resistant bacteria to ciprofloxacin were decreased:6 strains (60%) and 8 strains (80%) in the presence of reserpine and CCCP respectively. The positive efflux pump Klebsiella prveumoniae strains in the presence of reserpine and CCCP were 4(40%) and 6(60%) respectively. Conclusions The high drug-resistance Klebsiella pneumoniae can be artificialy induced with concentration gradient of ciprofloxaein. The efflux pump inhibitors can obviously improve the antibacterial activities of ciprofloxacin in drug-resistance Klebsiella pneumoaiae.

  3. Next-generation sequencing for sensitive detection of BCR-ABL1 mutations relevant to tyrosine kinase inhibitor choice in imatinib-resistant patients

    Science.gov (United States)

    Soverini, Simona; De Benedittis, Caterina; Polakova, Katerina Machova; Linhartova, Jana; Castagnetti, Fausto; Gugliotta, Gabriele; Papayannidis, Cristina; Mancini, Manuela; Klamova, Hana; Salvucci, Marzia; Crugnola, Monica; Iurlo, Alessandra; Albano, Francesco; Russo, Domenico; Rosti, Gianantonio; Cavo, Michele; Baccarani, Michele; Martinelli, Giovanni

    2016-01-01

    In chronic myeloid leukemia (CML) and Philadelphia-positive (Ph+) acute lymphoblastic leukemia (ALL) patients who fail imatinib treatment, BCR-ABL1 mutation profiling by Sanger sequencing (SS) is recommended before changing therapy since detection of specific mutations influences second-generation tyrosine kinase inhibitor (2GTKI) choice. We aimed to assess i) in how many patients who relapse on second-line 2GTKI therapy next generation sequencing (NGS) may track resistant mutations back to the sample collected at the time of imatinib resistance, before 2GTKI start (switchover sample) and ii) whether low level mutations identified by NGS always undergo clonal expansion. To this purpose, we used NGS to retrospectively analyze 60 imatinib-resistant patients (CML, n = 45; Ph+ ALL, n = 15) who had failed second-line 2GTKI therapy and had acquired BCR-ABL1 mutations (Group 1) and 25 imatinib-resistant patients (CML, n = 21; Ph+ ALL, n = 4) who had responded to second-line 2GTKI therapy, for comparison (Group 2). NGS uncovered that in 26 (43%) patients in Group 1, the 2GTKI-resistant mutations that triggered relapse were already detectable at low levels in the switchover sample (median mutation burden, 5%; range 1.1%–18.4%). Importantly, none of the low level mutations detected by NGS in switchover samples failed to expand whenever the patient received the 2GTKI to whom they were insensitive. In contrast, no low level mutation that was resistant to the 2GTKI the patients subsequently received was detected in the switchover samples from Group 2. NGS at the time of imatinib failure reliably identifies clinically relevant mutations, thus enabling a more effective therapeutic tailoring. PMID:26980736

  4. Regulating Chondrogenesis of Human Mesenchymal Stromal Cells with a Retinoic Acid Receptor-Beta Inhibitor: Differential Sensitivity of Chondral Versus Osteochondral Development

    Directory of Open Access Journals (Sweden)

    Solvig Diederichs

    2014-05-01

    Full Text Available Aim: Main objective was to investigate whether the synthetic retinoic acid receptor (RAR-β antagonist LE135 is able to drive in vitro chondrogenesis of human mesenchymal stromal cells (MSCs or improve differentiation by suppressing hypertrophic chondrocyte development. Methods: Chondrogenesis of human bone marrow and adipose tissue-derived MSCs was induced in micromass pellet culture for six weeks. Effects of LE135 alone and in combinatorial treatment with TGF-β on deposition of cartilaginous matrix including collagen type II and glycosaminoglycans, on deposition of non-hyaline cartilage collagens type I and X, and on hypertrophy markers including alkaline phosphatase (ALP, indian hedghehog (IHH and matrix metalloproteinase (MMP-13 were assessed. Results: LE135 was no inducer of chondrogenesis and failed to stimulate deposition of collagen type II and glycosaminoglycans. Moreover, addition of LE135 to TGF-β-treated pellets inhibited cartilaginous matrix deposition and gene expression of COL2A1. In contrast, non-hyaline cartilage collagens were less sensitive to LE135 and hypertrophy markers remained unaffected. Conclusion: This demonstrates a differential sensitivity of chondral versus endochondral differentiation pathways to RARβ signaling; however, opposite to the desired direction. The relevance of trans-activating versus trans-repressing RAR signaling, including effects on activator protein (AP-1 is discussed and implications for overcoming current limits of hMSC chondrogenesis are considered.

  5. K-Ras突变对表皮生长因子受体抑制剂敏感细胞株的影响%The influence of K-Ras mutation on epidermal growth factor receptor inhibitor sensitive cell lines

    Institute of Scientific and Technical Information of China (English)

    杨帆; 陈克终; 隋锡朝; 李剑锋; 王俊; 姜冠潮

    2010-01-01

    目的 观察K-Ras突变对于携带表皮生长因子受体(EGFR)突变细胞的EGFR抑制剂敏感性的影响.方法 构建K-Ras突变真核表达质粒,采用脂质体转染技术转染肺癌细胞HCC827(EGFR突变,K-Ras野生)和H292(EGFR、K-Ras均野生),噻唑蓝(MTT)比色法测定转染K-Pas突变质粒和空白质粒后各细胞对EGFR抑制剂的半数抑制浓度(IC_(50)).结果 真核表达质粒构建成功.细胞HCC827未转染K-ras突变质粒对吉非替尼(Iressa)的IC_(50)为0.007,转染后对Iressa的IC_(50)为12.3,差异有统计学意义(P0.05).结论 野生型或突变型EGFR出现K-Ras突变均可引起吉非替尼耐药,其程度与K-Ras突变的细胞株相当.%Objective By comparing the sensitivity of gefitinib in different cell lines affected by K-Ras mutation,to investigate the change of epidermal growth factor receptor(EGFR)inhibitors sensitivity on EGFR mutation cells with K-Ras mutation.Methods The eukaryotic expression plasmid pcDNA3.1 (-)K-Ras(+)was constyructed,transfected into lung cancer cells HCC827(EGFR mutation,K-Ras Wild-type)and H292(EGFR Wild-type,K-Ras Wild-type)by liposome respectively.MTT was used to measured the semitivity and median lethal concentration IC_(50) of EGFR inhibitors gefitinib after K-Ras or blank plasmid was induced to ceils.Results The sequencing results confirmed the success of eukaryotic expression plasmid.IC_(50) H of gefitinib for HCC827(K-Ras mutation)and HCC827(K-Ras Wild-type)was 12.3,and 0.007(P0.05).Conclusion Whether with EGFR mutations or not,the sensitivity to gefitinib waft significantly decreased with K-Ras mutant transfection,and the extent of resistance Was close to cells carrying K-Ras mutation.

  6. The dynamin chemical inhibitor dynasore impairs cholesterol trafficking and sterol-sensitive genes transcription in human HeLa cells and macrophages.

    Directory of Open Access Journals (Sweden)

    Emmanuelle Girard

    Full Text Available Intracellular transport of cholesterol contributes to the regulation of cellular cholesterol homeostasis by mechanisms that are yet poorly defined. In this study, we characterized the impact of dynasore, a recently described drug that specifically inhibits the enzymatic activity of dynamin, a GTPase regulating receptor endocytosis and cholesterol trafficking. Dynasore strongly inhibited the uptake of low-density lipoprotein (LDL in HeLa cells, and to a lower extent in human macrophages. In both cell types, dynasore treatment led to the abnormal accumulation of LDL and free cholesterol (FC within the endolysosomal network. The measure of cholesterol esters (CE further showed that the delivery of regulatory cholesterol to the endoplasmic reticulum (ER was deficient. This resulted in the inhibition of the transcriptional control of the three major sterol-sensitive genes, sterol-regulatory element binding protein 2 (SREBP-2, 3-hydroxy-3-methyl-coenzymeA reductase (HMGCoAR, and low-density lipoprotein receptor (LDLR. The sequestration of cholesterol in the endolysosomal compartment impaired both the active and passive cholesterol efflux in HMDM. Our data further illustrate the importance of membrane trafficking in cholesterol homeostasis and validate dynasore as a new pharmacological tool to study the intracellular transport of cholesterol.

  7. miR-378a-3p modulates tamoxifen sensitivity in breast cancer MCF-7 cells through targeting GOLT1A

    OpenAIRE

    Kazuhiro Ikeda; Kuniko Horie-Inoue; Toshihide Ueno; Takashi Suzuki; Wataru Sato; Takashi Shigekawa; Akihiko Osaki; Toshiaki Saeki; Eugene Berezikov; Hiroyuki Mano; Satoshi Inoue

    2015-01-01

    Breast cancer is a hormone-dependent cancer and usually treated with endocrine therapy using aromatase inhibitors or anti-estrogens such as tamoxifen. A majority of breast cancer, however, will often fail to respond to endocrine therapy. In the present study, we explored miRNAs associated with endocrine therapy resistance in breast cancer. High-throughput miRNA sequencing was performed using RNAs prepared from breast cancer MCF-7 cells and their derivative clones as endocrine therapy resistan...

  8. Rapid increase in aggressive behavior precedes the decrease in brain aromatase activity during socially mediated sex change in Lythrypnus dalli

    OpenAIRE

    Black, Michael P; Balthazart, Jacques; Baillien, Michelle; Grober, Matthew S.

    2010-01-01

    In the bluebanded goby, Lythrypnus dalli, removal of the male from a social group results in a rapid behavioral response where one female becomes dominant and changes sex to male. In a previous study, within hours of male removal, aromatase activity in the brain (bAA) of dominant females was almost 50% lower than that of control females from a group in which the male had not been removed. For those females that displayed increased aggressive behavior after the male was removed, the larger the...

  9. Hepatic glucose intolerance precedes hepatic steatosis in the male aromatase knockout (ArKO mouse.

    Directory of Open Access Journals (Sweden)

    Michelle L Van Sinderen

    Full Text Available Estrogens are known to play a role in modulating metabolic processes within the body. The Aromatase knockout (ArKO mice have been shown to harbor factors of Metabolic syndrome with central adiposity, hyperinsulinemia and male-specific hepatic steatosis. To determine the effects of estrogen ablation and subsequent replacement in males on whole body glucose metabolism, three- and six-month-old male ArKO mice were subjected to whole body glucose, insulin and pyruvate tolerance tests and analyzed for ensuing metabolic changes in liver, adipose tissue, and skeletal muscle. Estrogen-deficient male ArKO mice showed increased gonadal adiposity which was significantly reduced upon 17β-estradiol (E2 treatment. Concurrently, elevated ArKO serum leptin levels were significantly reduced upon E2 treatment and lowered serum adiponectin levels were restored to wild type levels. Three-month-old male ArKO mice were hyperglycemic, and both glucose and pyruvate intolerant. These phenotypes continued through to 6 months of age, highlighting a loss of glycemic control. ArKO livers displayed changes in gluconeogenic enzyme expression, and in insulin signaling pathways upon E2 treatment. Liver triglycerides were increased in the ArKO males only after 6 months of age, which could be reversed by E2 treatment. No differences were observed in insulin-stimulated ex vivo muscle glucose uptake nor changes in ArKO adipose tissue and muscle insulin signaling pathways. Therefore, we conclude that male ArKO mice develop hepatic glucose intolerance by the age of 3 months which precedes the sex-specific development of hepatic steatosis. This can be reversed upon the administration of exogenous E2.

  10. Comparison of the effect of cortisol on aromatase activity and androgen metabolism in two human fibroblast cell lines derived from the same individual

    DEFF Research Database (Denmark)

    Svenstrup, B; Brünner, N; Dombernowsky, P;

    1990-01-01

    The effect of preincubation with cortisol on estrogen and androgen metabolism was investigated in human fibroblast monolayers grown from biopsies of genital and non-genital skin of the same person. The activity in the cells of aromatase, 5 alpha-reductase, 17 beta-hydroxysteroid oxidoreductase...... with 14C-labeled substrate the cells were incubated in medium, charcoal stripped of steroids without Phenol Red. Preincubation from 6 to 36 h with cortisol in concentrations of 10(-8) - 10(-6) M showed maximal stimulation of aromatase activity after 12 h preincubation with cortisol in concentrations of 0...... and for investigations of the in vitro regulation of the enzymes involved....

  11. Thioredoxin reductase inhibitor ethaselen increases the drug sensitivity of the colon cancer cell line LoVo towards cisplatin via regulation of G1 phase and reversal of G2/M phase arrest.

    Science.gov (United States)

    Fu, Jia-Ning; Li, Jing; Tan, Qiang; Yin, Han-Wei; Xiong, Kun; Wang, Tian-Yu; Ren, Xiao-Yuan; Zeng, Hui-Hui

    2011-08-01

    We evaluated the combination treatment of ethaselen (BBSKE) as a thioredoxin reductase (TrxR) inhibitor plus cisplatin (CDDP) on the human colon adenocarcinoma cell line LoVo. Therapeutic effects ranging from nearly additive to clearly synergistic demonstrated an effective combination, i.e., the cytostatic dose of CDDP could be reduced without a loss in efficacy. To further investigate the cellular response mechanisms of these favorable outcomes, we analyzed the cell-cycle profiles, mRNA expression patterns, and protein levels of several key genes after incubation with BBSKE or CDDP separately and in combination. In appropriate conditions, CDDP induced arrest at the G2/M phase accompanied by the enhanced inhibitory phosphorylation of Cdk1 and the elevated protein expression of cyclin B1. BBSKE downregulated expression of cyclin D1 by increasing mRNA and protein levels of p21, and thus induced G1 phase arrest. BBSKE returned Cdk1 to an activated state, and reduced the protein level of cyclin B1 after incubation in combination with CDDP, which was consistent with the reduction in the percentage of cells in G2/M identified by flow cytometry. By regulating the G1 phase and reversing CDDP-induced G2/M phase arrest, BBSKE increases drug sensitivity of LoVo cells toward CDDP, and probably provides a meaningful anticancer strategy for further clinical studies.

  12. In vivo imaging of brain aromatase in female baboons: [11C]vorozole kinetics and effect of the menstrual cycle.

    Science.gov (United States)

    Pareto, Deborah; Biegon, Anat; Alexoff, David; Carter, Pauline; Shea, Coreen; Muench, Lisa; Xu, Youwen; Fowler, Joanna S; Kim, Sunny W; Logan, Jean

    2013-01-01

    The aim of this work was to quantify the brain distribution of the enzyme aromatase in the female baboon with positron emission tomography and the tracer [11C]vorozole using three different quantification methods for estimating the total distribution volume (V(T)): a graphical method, compartment modeling, and a tissue to plasma ratio. The graphical model and the compartment modeling gave similar estimates to the data and similar values (correlation R  =  .988; p  =  .0001). [11C]Vorozole shows a rapid uptake by the brain followed by a relatively constant accumulation, suggesting the possibility of using the tissue to plasma ratio as an estimate of V(T). The highest uptake of [11C]vorozole in the baboon brain was measured in the amygdala, followed by the preoptic area and hypothalamus, basal ganglia, and cortical areas. Pretreatment studies with vorozole or letrozole showed a generalized decrease in brain accumulation and V(T). The results suggested that the physiologic changes in gonadal hormone levels accompanying the menstrual cycle had a significant effect on brain aromatase V(T).

  13. Brain cytochrome P450 aromatase activity in roach (Rutilus rutilus): seasonal variations and impact of environmental contaminants.

    Science.gov (United States)

    Geraudie, Perrine; Hinfray, Nathalie; Gerbron, Marie; Porcher, Jean-Marc; Brion, François; Minier, Christophe

    2011-10-01

    P450 aromatase catalyses the conversion of C19 androgens to C18 estrogens which is thought to be essential for the regulation of the reproductive function. In this study, brain aromatase activity (AA) was measured monthly over a reproductive cycle in wild roach (Rutilus rutilus) sampled in a reference site in Normandy. AA peaked during the breeding season, reaching 35 fmol mg(-1)min(-1) in both male and female fish, and was low during the rest of the year except for a significant rise in October. AA was correlated with ovary maturation (measured either as gonado-somatic index or by histological analysis of the gonads) and plasma sex-steroid levels (11-ketotestosterone in males and 17-β-estradiol in females). Measurements of AA in polluted sites showed that activity was significantly upregulated in sites with fish showing high levels of plasma vitellogenin and large proportion of intersexuality (20-50%) thus suggesting the occurrence of estrogenic compounds and their involvement in AA modulation. PMID:21820384

  14. Co-Formulants in Glyphosate-Based Herbicides Disrupt Aromatase Activity in Human Cells below Toxic Levels

    Science.gov (United States)

    Defarge, Nicolas; Takács, Eszter; Lozano, Verónica Laura; Mesnage, Robin; Spiroux de Vendômois, Joël; Séralini, Gilles-Eric; Székács, András

    2016-01-01

    Pesticide formulations contain declared active ingredients and co-formulants presented as inert and confidential compounds. We tested the endocrine disruption of co-formulants in six glyphosate-based herbicides (GBH), the most used pesticides worldwide. All co-formulants and formulations were comparably cytotoxic well below the agricultural dilution of 1% (18–2000 times for co-formulants, 8–141 times for formulations), and not the declared active ingredient glyphosate (G) alone. The endocrine-disrupting effects of all these compounds were measured on aromatase activity, a key enzyme in the balance of sex hormones, below the toxicity threshold. Aromatase activity was decreased both by the co-formulants alone (polyethoxylated tallow amine—POEA and alkyl polyglucoside—APG) and by the formulations, from concentrations 800 times lower than the agricultural dilutions; while G exerted an effect only at 1/3 of the agricultural dilution. It was demonstrated for the first time that endocrine disruption by GBH could not only be due to the declared active ingredient but also to co-formulants. These results could explain numerous in vivo results with GBHs not seen with G alone; moreover, they challenge the relevance of the acceptable daily intake (ADI) value for GBHs exposures, currently calculated from toxicity tests of the declared active ingredient alone. PMID:26927151

  15. Weight gain and inflammation regulate aromatase expression in male adipose tissue, as evidenced by reporter gene activity.

    Science.gov (United States)

    Polari, L; Yatkin, E; Martínez Chacón, M G; Ahotupa, M; Smeds, A; Strauss, L; Zhang, F; Poutanen, M; Saarinen, N; Mäkelä, S I

    2015-09-01

    Obesity and white adipose tissue (WAT) inflammation are associated with enhanced aromatization in women, but little is known about the regulation of aromatase (CYP19A1) gene expression in male WAT. We investigated the impact of weight gain and WAT inflammation on the regulation of CYP19A1 in males, by utilizing the hARO-Luc aromatase reporter mouse model containing a >100-kb 5'-region of the human CYP19A1 gene. We show that hARO-Luc reporter activity is enhanced in WAT of mice with increased adiposity and inflammation. Dexamethasone and TNFα, as well as forskolin and phorbol 12-myristate 13-acetate, upregulate hARO-Luc activity, suggesting the involvement of promoters I.4 and I.3/II. Furthermore, we show that diet enriched with antioxidative plant polyphenols attenuates WAT inflammation and hARO-Luc activity in obese males. In conclusion, our data suggest that obesity-associated WAT inflammation leads to increased peripheral CYP19A1 expression in males, and that polyphenol-enriched diet may have the potential to attenuate excessive aromatization in WAT of obese men. PMID:26054748

  16. Differential responsiveness of luteinized human granulosa cells to gonadotropins and insulin-like growth factor I for induction of aromatase activity

    International Nuclear Information System (INIS)

    The objective of this study was to examine the in vitro responsiveness of cultured luteinized human granulosa cells over time to insulin-like growth factor 1 (IGF-1), human follicle-stimulating hormone (FSH), and human chorionic gonadotropin (hCG) for the induction of aromatase activity. Granulosa cells were retrieved from preovulatory follicles in patients undergoing in vitro fertilization. Cells were cultured for a period of 72 hours or 10 days. The ability of hCG, human FSH, and/or IGF-I to induce aromatase activity was assayed by the stereospecific release of tritium from [1B-3H]androstenedione. Short-term cultures (72 hours) demonstrated a marked rise in aromatase activity in response to human FSH and IGF-I, whereas a smaller response to hCG was observed. In contrast, 10-day cultures demonstrated responsiveness predominantly to hCG rather than human FSH for the induction of aromatase activity with no remarkable effect of IGF-I. Luteinized human granulosa cells undergo a transformation from an initial human FSH and IGF-I responsive state to an hCG responsive state in long-term cultures

  17. Age-related decrease in aromatase and estrogen receptor(ERαand ERβ) expression in rat testes: protective effect of low caloric diets

    Institute of Scientific and Technical Information of China (English)

    Khaled Hamden; Dorothee Silandre; Christelle Delalande; Abdefattah El Feki; Serge Carreau

    2008-01-01

    Aim: To examine the effects on rat aging of caloric restriction (CR1) and undernutrition (CR2) on the body and on testicular weights, on two enzymatic antioxidants (superoxide dismutase and catalase), on lipid peroxidation and on the expression of testicular aromatase and estrogen receptors (ER). Methods: CR was initiated in 1-month-old rats and carried on until the age of 18 months. Results: In control and CR2 rats an age-related decrease of the aromatase and of ER (α and β) gene expression was observed; in parallel a diminution of testicular weights, and of the total number and motility of epididymal spermatozo was recorded. In addition, aging in control and CR2 rats was accom-panied by a significant decrease in testicular superoxide dismutase, catalase activities, and an increase in lipid peroxidation level (thiobarbituric acid reactive substance), associated with alterations of spermatogenesis. Conversely, caloric restriction-treatment exerted a protective effect and all the parameters were less affected by aging. Conclusion:These results indicate that during aging, a low caloric diet (not undernutrition) is beneficial for spermatogenesis and likely improves the protection of the cells via an increase of the cellular antioxidant defense system in which aromatase/ER could play a role.

  18. Isolation and characterization of goat ovarian aromatase cDNA: assessment of the activity using an intact cell system and placental expression.

    Science.gov (United States)

    Bobes, Raúl José; Miranda, Carolina; Pérez-Martinez, Mario; Luu-The, Van; Romano, Marta C

    2004-08-01

    Goat ovarian follicles produce estrone and estradiol from androgens. The synthesis of C18 estrogens from C19 androgens requires cytochrome P450 aromatase, but little information about this key enzyme is available in the goat. We report here for the first time the cDNA sequence of the goat ovarian aromatase, the activity of the enzyme in a cell system, and its expression in the term goat placenta. A cDNA library from goat ovarian poly(A)+ RNA was constructed. Human aromatase cDNA was selected as probe to screen the library; several clones were isolated, but none was complete. The longest clone was 3.1 kb long, but it lacked the sequence coding for a few amino acids in the NH(2)-terminal. To obtain the missing sequence, we performed reverse amplification of the cDNA end (RACE). Sequence analysis indicated that goat aromatase possessed a very long 3'-untranslated region ( approximately 1790 bp), and a polyadenylation signal (AATAAA) located at position 3320 downstream from the ATG start codon. The coding region of goat cDNA was inserted in an expression vector and transfected into HEK-293 cells that were cultured in presence of [14C]-androstenedione, steroids extracted and further separated by TLC. The transfected cells efficiently transformed [14C]-androstenedione into estrone. This activity was inhibited by 4-hydroxyandrostenedione. We also investigated the presence of mRNA for P450 aromatase in the goat placenta, using reverse transcription-polymerase chain reaction (RT-PCR) and primers derived from the cDNA ovarian sequence and confirmed the expression of the mRNA in term placenta.

  19. Reinvestigation of the synthesis and evaluation of [N-methyl-{sup 11}C]vorozole, a radiotracer targeting cytochrome P450 aromatase

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Won [Medical Department, Brookhaven National Laboratory, Upton, NY 11973 (United States)], E-mail: swkim@bnl.gov; Biegon, Anat; Katsamanis, Zachary E. [Medical Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Ehrlich, Carolin W. [Johannes-Gutenberg Universitaet Mainz, Institut fuer Organische Chemie, Duesbergweg 10-14, Mainz (Germany); Hooker, Jacob M.; Shea, Colleen [Medical Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Muench, Lisa [National Institute on Alcoholism and Alcohol Abuse, Bethesda, MD (United States); Xu Youwen; King, Payton; Carter, Pauline; Alexoff, David L. [Medical Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Fowler, Joanna S. [Medical Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Department of Psychiatry, Mount Sinai School of Medicine, New York, NY (United States); Department of Chemistry, State University of New York at Stony Brook, Stony Brook, NY (United States)

    2009-04-15

    Introduction: We reinvestigated the synthesis of [N-methyl-{sup 11}C]vorozole, a radiotracer for aromatase, and discovered the presence of an N-methyl isomer which was not removed in the original purification method. Herein we report the preparation and positron emission tomography (PET) studies of pure [N-methyl-{sup 11}C]vorozole. Methods: Norvorozole was alkylated with [{sup 11}C]methyl iodide as previously described and also with unlabeled methyl iodide. A high-performance liquid chromatography (HPLC) method was developed to separate the regioisomers. Nuclear magnetic resonance (NMR) spectroscopy ({sup 13}C and 2D-nuclear Overhauser effect spectroscopy NMR) was used to identify and assign structures to the N-methylated products. Pure [N-methyl-{sup 11}C]vorozole and the contaminating isomer were compared by PET imaging in the baboon. Results: Methylation of norvorozole resulted in a mixture of isomers (1:1:1 ratio) based on new HPLC analysis using a pentafluorophenylpropyl bonded silica column, in which vorozole coeluted one of its isomers under the original HPLC conditions. Baseline separation of the three labeled isomers was achieved. The N-3 isomer was the contaminant of vorozole, thus correcting the original assignment of isomers. PET studies of pure [N-methyl-{sup 11}C]vorozole with and without the contaminating N-3 isomer revealed that only [N-methyl-{sup 11}C]vorozole binds to aromatase. [N-methyl-{sup 11}C]Vorozole accumulated in all brain regions with highest accumulation in the aromatase-rich amygdala and preoptic area. Accumulation was blocked with vorozole and letrozole consistent with reports of some level of aromatase in many brain regions. Conclusions: The discovery of a contaminating labeled isomer and the development of a method for isolating pure [N-methyl-{sup 11}C]vorozole combine to provide a new scientific tool for PET studies of the biology of aromatase and for drug research and development.

  20. Reinvestigation of the synthesis and evaluation of [N-methyl-11C]vorozole, a radiotracer targeting cytochrome P450 aromatase

    International Nuclear Information System (INIS)

    Introduction: We reinvestigated the synthesis of [N-methyl-11C]vorozole, a radiotracer for aromatase, and discovered the presence of an N-methyl isomer which was not removed in the original purification method. Herein we report the preparation and positron emission tomography (PET) studies of pure [N-methyl-11C]vorozole. Methods: Norvorozole was alkylated with [11C]methyl iodide as previously described and also with unlabeled methyl iodide. A high-performance liquid chromatography (HPLC) method was developed to separate the regioisomers. Nuclear magnetic resonance (NMR) spectroscopy (13C and 2D-nuclear Overhauser effect spectroscopy NMR) was used to identify and assign structures to the N-methylated products. Pure [N-methyl-11C]vorozole and the contaminating isomer were compared by PET imaging in the baboon. Results: Methylation of norvorozole resulted in a mixture of isomers (1:1:1 ratio) based on new HPLC analysis using a pentafluorophenylpropyl bonded silica column, in which vorozole coeluted one of its isomers under the original HPLC conditions. Baseline separation of the three labeled isomers was achieved. The N-3 isomer was the contaminant of vorozole, thus correcting the original assignment of isomers. PET studies of pure [N-methyl-11C]vorozole with and without the contaminating N-3 isomer revealed that only [N-methyl-11C]vorozole binds to aromatase. [N-methyl-11C]Vorozole accumulated in all brain regions with highest accumulation in the aromatase-rich amygdala and preoptic area. Accumulation was blocked with vorozole and letrozole consistent with reports of some level of aromatase in many brain regions. Conclusions: The discovery of a contaminating labeled isomer and the development of a method for isolating pure [N-methyl-11C]vorozole combine to provide a new scientific tool for PET studies of the biology of aromatase and for drug research and development.

  1. Attenuation of the DNA Damage Response by Transforming Growth Factor-Beta Inhibitors Enhances Radiation Sensitivity of Non–Small-Cell Lung Cancer Cells In Vitro and In Vivo

    Energy Technology Data Exchange (ETDEWEB)

    Du, Shisuo; Bouquet, Sophie; Lo, Chen-Hao; Pellicciotta, Ilenia; Bolourchi, Shiva [Department of Radiation Oncology, New York University School of Medicine, New York, New York (United States); Parry, Renate [Varian Medical Systems, Palo Alto, California (United States); Barcellos-Hoff, Mary Helen, E-mail: mhbarcellos-hoff@nyumc.org [Department of Radiation Oncology, New York University School of Medicine, New York, New York (United States)

    2015-01-01

    Purpose: To determine whether transforming growth factor (TGF)-β inhibition increases the response to radiation therapy in human and mouse non–small-cell lung carcinoma (NSCLC) cells in vitro and in vivo. Methods and Materials: TGF-β–mediated growth response and pathway activation were examined in human NSCLC NCI-H1299, NCI-H292, and A549 cell lines and murine Lewis lung cancer (LLC) cells. Cells were treated in vitro with LY364947, a small-molecule inhibitor of the TGF-β type 1 receptor kinase, or with the pan-isoform TGF-β neutralizing monoclonal antibody 1D11 before radiation exposure. The DNA damage response was assessed by ataxia telangiectasia mutated (ATM) or Trp53 protein phosphorylation, γH2AX foci formation, or comet assay in irradiated cells. Radiation sensitivity was determined by clonogenic assay. Mice bearing syngeneic subcutaneous LLC tumors were treated with 5 fractions of 6 Gy and/or neutralizing or control antibody. Results: The NCI-H1299, A549, and LLC NSCLC cell lines pretreated with LY364947 before radiation exposure exhibited compromised DNA damage response, indicated by decreased ATM and p53 phosphorylation, reduced γH2AX foci, and increased radiosensitivity. The NCI-H292 cells were unresponsive. Transforming growth factor-β signaling inhibition in irradiated LLC cells resulted in unresolved DNA damage. Subcutaneous LLC tumors in mice treated with TGF-β neutralizing antibody exhibited fewer γH2AX foci after irradiation and significantly greater tumor growth delay in combination with fractionated radiation. Conclusions: Inhibition of TGF-β before radiation attenuated DNA damage recognition and increased radiosensitivity in most NSCLC cells in vitro and promoted radiation-induced tumor control in vivo. These data support the rationale for concurrent TGF-β inhibition and RT to provide therapeutic benefit in NSCLC.

  2. Bisphenol A exposure during adulthood alters expression of aromatase and 5α-reductase isozymes in rat prostate.

    Directory of Open Access Journals (Sweden)

    Beatriz Castro

    Full Text Available The high incidence of prostate cancer (PCa and benign prostatic hypertrophy (BPH in elderly men is a cause of increasing public health concern. In recent years, various environmental endocrine disruptors, such as bisphenol A (BPA, have been shown to disrupt sexual organs, including the prostate gland. However, the mechanisms underlying these effects remain unclear. Because androgens and estrogens are important factors in prostate physiopathology, our objective was to examine in rat ventral prostate the effects of adult exposure to BPA on 5α-Reductase isozymes (5α-R types 1, 2, and 3 and aromatase, key enzymes in the biosynthesis of dihydrotestosterone and estradiol, respectively. Adult rats were subcutaneously injected for four days with BPA (25, 50, 300, or 600 µg/Kg/d dissolved in vehicle. Quantitative RT-PCR, western blot and immunohistochemical analyses showed lower mRNA and protein levels of 5α-R1 and 5α-R2 in BPA-treated groups versus controls but higher mRNA levels of 5α-R3, recently proposed as a biomarker of malignancy. However, BPA treatment augmented mRNA and protein levels of aromatase, whose increase has been described in prostate diseases. BPA-treated rats also evidenced a higher plasma estradiol/testosterone ratio, which is associated with prostate disease. Our results may offer new insights into the role of BPA in the development of prostate disease and may be of great value for studying the prostate disease risk associated with exposure to BPA in adulthood.

  3. Evaluation of a bioluminescent mouse model expressing aromatase PII-promoter-controlled luciferase as a tool for the study of endocrine disrupting chemicals

    International Nuclear Information System (INIS)

    Dysfunction of the enzyme aromatase (CYP19) is associated with endocrine pathologies such as osteoporosis, impaired fertility and development of hormone-dependent cancers. Certain endocrine disrupting chemicals affect aromatase expression and activity in vitro, but little is known about their ability to do so in vivo. We evaluated a bioluminescent mouse model (LPTA (registered) )CD-1-Tg(Cyp19-luc)-Xen) expressing luciferase under control of the gonadal aromatase pII promoter as an in vivo screening tool for chemicals that may affect aromatase expression. We studied the effects of forskolin, pregnant mare serum gonadotropin and atrazine in this model (atrazine was previously shown to induced pII-promoter-driven aromatase expression in H295R human adrenocortical carcinoma cells). About 2-4 out of every group of 10 male or female Cyp19-luc mice injected i.p. with 10 mg/kg forskolin had increased gonadal bioluminescence after 3-5 days compared to controls; the others appeared non-responsive. Similarly, about 4 per group of 9 individual females injected with pregnant mare serum gonadotropin had increased ovarian bioluminescence after 24 h. There was a statistically significant correlation between ovarian bioluminescence and plasma estradiol concentrations (n = 14; p = 0.022). Males exposed to a single dose of 100 mg/kg or males and females exposed to 5 daily injections of 30 mg/kg atrazine showed no change in gonadal bioluminescence over a 7 day period, but a significant interaction was found between atrazine (100 mg/kg) and time in female mice (p < 0.05; two-way ANOVA). Ex vivo luciferase activity in dissected organs was increased by forskolin in testis, epididymis and ovaries. Atrazine (30 mg/kg/day) increased (30%) luciferase activity significantly in epididymis only. In conclusion, certain individual Cyp19-luc mice are highly responsive to aromatase inducers, suggesting this model, with further optimization, may have potential as an in vivo screening tool for

  4. AGN-2979, an inhibitor of tryptophan hydroxylase activation, does not affect serotonin synthesis in Flinders Sensitive Line rats, a rat model of depression, but produces a significant effect in Flinders Resistant Line rats.

    Science.gov (United States)

    Kanemaru, Kazuya; Nishi, Kyoko; Diksic, Mirko

    2009-12-01

    The neurotransmitter, serotonin, is involved in several brain functions, including both normal, physiological functions, and pathophysiological functions. Alterations in any of the normal parameters of serotonergic neurotransmission can produce several different psychiatric disorders, including major depression. In many instances, brain neurochemical variables are not able to be studied properly in humans, thus making the use of good animal models extremely valuable. One of these animal models is the Flinders Sensitive Line (FSL) of rats, which has face, predictive and constructive validities in relation to human depression. The objective of this study was to quantify the effect of the tryptophan hydroxylase (TPH) activation inhibitor, AGN-2979, on the FSL rats (rats with depression-like behaviour), and compare it to the effect on the Flinders Resistant Line (FRL) of rats used as the control rats. The effect was evaluated by measuring changes in regional serotonin synthesis in the vehicle treated rats (FSL-VEH and FRL-VEH) relative to those measured in the AGN-2979 treated rats (FSL-AGN and FRL-AGN). Regional serotonin synthesis was measured autoradiographically in more than 30 brain regions. The measurements were performed using alpha-[(14)C]methyl-l-tryptophan as the tracer. The results indicate that AGN-2979 did not produce a significant reduction of TPH activity in the AGN-2979 group relative to the vehicle group (a reduction would have been observed if there had been an activation of TPH by the experimental setup) in the FSL rats. On the other hand, there was a highly significant reduction of synthesis in the FRL rats treated by AGN-2979, relative to the vehicle group. Together, the results demonstrate that in the FSL rats, AGN-2979 does not affect serotonin synthesis. This suggests that there was no activation of TPH in the FSL rats during the experimental procedure, but such activation did occur in the FRL rats. Because of this finding, it could be

  5. Effect of butyrate on aromatase cytochrome P450 levels in HT29, DLD-1 and LoVo colon cancer cells.

    Science.gov (United States)

    Rawłuszko, Agnieszka Anna; Sławek, Sylwia; Gollogly, Armin; Szkudelska, Katarzyna; Jagodziński, Paweł Piotr

    2012-03-01

    Epidemiological studies suggest that colonic production of butyrate and estrogen may be involved in human susceptibility to colorectal cancer (CRC). Estrone (E1) can be produced by the aromatase pathway during the conversion of androstenedione (A) to E1. Therefore, we studied the effect of sodium butyrate (NaBu) on the CYP19A1 transcript and protein levels and on the conversion of A to E1 in HT29, DLD-1 and LoVo CRC cells. We found that NaBu significantly downregulated CYP19A1 transcript and protein levels, a phenomenon that was associated with reduced conversion of A to E1 in HT29, DLD-1 and LoVo cells. Our studies demonstrated that, although butyrate exhibited a protective role in CRC development, this compound may reduce aromatase activity and the production of E1 in colon cancer cells.

  6. Immunolocalization of aromatase, estrogen and estrogen receptor α and β in the epithelium of digestive tract and enteric neurons of amphioxus (Branchiostoma belcheri )

    Institute of Scientific and Technical Information of China (English)

    FANG Yongqiang; WENG Youzhu; YE Rongzhong; LIU Lili

    2005-01-01

    Immunohistochemical localization of aromatase, estrogen and estrogen receptor in the digestive tract and enteric neurons of amphioxus is investigated. It was found that immunoreactive proteins of aromatase, estrogen and ER-α and β are expressed in hepatic diverticulum, epithelial cells of anterior and posterior region of midgut, as well as in enteric neurons, while hindgut showed immunonegative. The results suggest that digestive tract of amphioxus may be able to synthesize estrogen and possess endocrine function, like rat gastric epithelium and enteric neurons in mammals. The present study provides authentic morphological evidence for explaining the action mechanism of estrogen in regulating the digestive function of gut and the functional evolution of estrogen, which has important theoretical significance in amphioxus.

  7. Use of mTOR inhibitors in the treatment of breast cancer: an evaluation of factors that influence patient outcomes

    Directory of Open Access Journals (Sweden)

    Jerusalem G

    2014-04-01

    Full Text Available Guy Jerusalem, Andree Rorive, Joelle Collignon Medical Oncology, CHU Sart Tilman Liege, Domaine Universitaire du Sart Tilman, Liege, Belgium Abstract: Many systemic treatment options are available for advanced breast cancer, including endocrine therapy, chemotherapy, anti-human epidermal growth factor receptor 2 (HER2 therapy, and other targeted agents. Recently, everolimus, a mammalian target of rapamycin (mTOR inhibitor, combined with exemestane, an aromatase inhibitor, has been approved in Europe and the USA for patients suffering from estrogen receptor-positive, HER2-negative advanced breast cancer previously treated by a nonsteroidal aromatase inhibitor, based on the results of BOLERO-2 (Breast cancer trials of OraL EveROlimus. This study showed a statistically significant and clinically meaningful improvement in median progression-free survival. Results concerning the impact on overall survival are expected in the near future. This clinically oriented review focuses on the use of mTOR inhibitors in breast cancer. Results reported with first-generation mTOR inhibitors (ridaforolimus, temsirolimus, everolimus are discussed. The current and potential role of mTOR inhibitors is reported according to breast cancer subtype (estrogen receptor-positive HER2-negative, triple-negative, and HER2-positive ER-positive/negative disease. Everolimus is currently being evaluated in the adjuvant setting in high-risk estrogen receptor-positive, HER2-negative early breast cancer. Continuing mTOR inhibition or alternatively administering other drugs targeting the phosphatidylinositol-3-kinase/protein kinase B-mTOR pathway after progression on treatments including an mTOR inhibitor is under evaluation. Potential biomarkers to select patients showing a more pronounced benefit are reviewed, but we are not currently using these biomarkers in routine practice. Subgroup analysis of BOLERO 2 has shown that the benefit is consistent in all subgroups and that it is

  8. Dual Use Corrosion Inhibitor and Penetrant for Anomaly Detection in Neutron/X Radiography

    Science.gov (United States)

    Hall, Phillip B. (Inventor); Novak, Howard L. (Inventor)

    2004-01-01

    A dual purpose corrosion inhibitor and penetrant composition sensitive to radiography interrogation is provided. The corrosion inhibitor mitigates or eliminates corrosion on the surface of a substrate upon which the corrosion inhibitor is applied. In addition, the corrosion inhibitor provides for the attenuation of a signal used during radiography interrogation thereby providing for detection of anomalies on the surface of the substrate.

  9. Combined effects of EGFR tyrosine kinase inhibitors and vATPase inhibitors in NSCLC cells

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Hyeon-Ok [KIRAMS Radiation Biobank, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 139–706 (Korea, Republic of); Hong, Sung-Eun [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 139–706 (Korea, Republic of); Kim, Chang Soon [Department of Microbiological Engineering, Kon-Kuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 143–701 (Korea, Republic of); Park, Jin-Ah; Kim, Jin-Hee; Kim, Ji-Young; Kim, Bora [KIRAMS Radiation Biobank, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 139–706 (Korea, Republic of); Chang, Yoon Hwan; Hong, Seok-Il; Hong, Young Jun [Department of Laboratory Medicine, Korea Cancer Center Hospital, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 139–706 (Korea, Republic of); Park, In-Chul, E-mail: parkic@kirams.re.kr [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 139–706 (Korea, Republic of); Lee, Jin Kyung, E-mail: jklee@kirams.re.kr [KIRAMS Radiation Biobank, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 139–706 (Korea, Republic of); Department of Laboratory Medicine, Korea Cancer Center Hospital, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 139–706 (Korea, Republic of)

    2015-08-15

    Despite excellent initial clinical responses of non-small cell lung cancer (NSCLC) patients to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs), many patients eventually develop resistance. According to a recent report, vacuolar H + ATPase (vATPase) is overexpressed and is associated with chemotherapy drug resistance in NSCLC. We investigated the combined effects of EGFR TKIs and vATPase inhibitors and their underlying mechanisms in the regulation of NSCLC cell death. We found that combined treatment with EGFR TKIs (erlotinib, gefitinib, or lapatinib) and vATPase inhibitors (bafilomycin A1 or concanamycin A) enhanced synergistic cell death compared to treatments with each drug alone. Treatment with bafilomycin A1 or concanamycin A led to the induction of Bnip3 expression in an Hif-1α dependent manner. Knock-down of Hif-1α or Bnip3 by siRNA further enhanced cell death induced by bafilomycin A1, suggesting that Hif-1α/Bnip3 induction promoted resistance to cell death induced by the vATPase inhibitors. EGFR TKIs suppressed Hif-1α and Bnip3 expression induced by the vATPase inhibitors, suggesting that they enhanced the sensitivity of the cells to these inhibitors by decreasing Hif-1α/Bnip3 expression. Taken together, we conclude that EGFR TKIs enhance the sensitivity of NSCLC cells to vATPase inhibitors by decreasing Hif-1α/Bnip3 expression. We suggest that combined treatment with EGFR TKIs and vATPase inhibitors is potentially effective for the treatment of NSCLC. - Highlights: • Co-treatment with EGFR TKIs and vATPase inhibitors induces synergistic cell death • EGFR TKIs enhance cell sensitivity to vATPase inhibitors via Hif-1α downregulation • Co-treatment of these inhibitors is potentially effective for the treatment of NSCLC.

  10. Kinetic analysis of the three-step steroid aromatase reaction of human cytochrome P450 19A1.

    Science.gov (United States)

    Sohl, Christal D; Guengerich, F Peter

    2010-06-01

    Cytochrome P450 19A1 (P450 19A1), the aromatase, catalyzes the conversion of androgens to estrogens through a sequential three-step reaction, generating 19-hydroxy and 19-aldehyde intermediates en route to the product estrogen. A procedure for the heterologous expression and purification of P450 19A1 in Escherichia coli was developed (k(cat) of 0.06 s(-1) for the conversion of androstenedione to estrone). Binding of the substrate and intermediates show low micromolar dissociation constants and are at least two-step processes. Rates of reduction of the iron were fast in the presence of substrate, either intermediate, or product. P450 19A1 is a distributive rather than a processive enzyme, with the sequential reaction allowing free dissociation of the intermediates as revealed by pulse-chase experiments. Conversion of androstenedione to estrone (under single turnover conditions) generated a progress curve showing changes in the concentrations of the substrate, intermediates, and product. A minimal kinetic model containing the individual rate constants for the steps in P450 19A1 catalysis was developed to globally fit the time course of the overall reaction, the dissociation constants, the two-step ligand binding, the distributive character, the iron-reduction rates, and the steady-state conversion of the 19-hydroxy androstenedione and 19-aldehyde androstenedione intermediates to estrone. PMID:20385561

  11. Analysis of the rs10046 Polymorphism of Aromatase (CYP19 in Premenopausal Onset of Human Breast Cancer

    Directory of Open Access Journals (Sweden)

    Karin Zins

    2014-01-01

    Full Text Available The CYP19 gene encodes aromatase, an enzyme catalyzing the conversion of androgens to estrogens. Studies analyzing associations between single nucleotide polymorphisms in CYP19 and breast cancer risk have shown inconsistent results. The rs10046 polymorphism is located in the 3' untranslated region of the CYP19 gene, but the influence of this polymorphism on breast cancer risk is unclear. In this study, we investigated the impact of rs10046 SNP on breast cancer risk, age at onset and association with clinical characteristics in an Austrian population of 274 breast cancer patients and 253 controls. The results show that a significantly increased fraction of patients with the TT genotype of rs10046 develop breast cancer under the age of 50 (41.8% of TT patients, compared to 26.6% of C carriers; p = 0.018, Chi-square test. No rs10046 genotypes were significantly associated with increased breast cancer risk or patient characteristics other than age at onset. These results suggest that the rs10046 polymorphism in the CYP19 gene may have an effect on breast cancer susceptibility at an age under 50 in the investigated population.

  12. Effects of butachlor on estrogen receptor, vitellogenin and P450 aromatase gene expression in the early life stage of zebrafish.

    Science.gov (United States)

    Chang, Juhua; Gui, Wenjun; Wang, Minghua; Zhu, Guonian

    2012-01-01

    Butachlor has adverse effects on fecundity and disrupts sex hormone homeostasis in adult zebrafish, but the underlying molecular mechanisms are still unclear. In the present study, zebrafish (Danio rerio) embryos were exposed to various concentrations of butachlor from 2 h post-fertilization (hpf) to 30 days post-fertilization (dpf). The transcription of genes involved estrogen receptors (ERα, ERβ1 and ERβ2), vitellogenins (VTG I and II), and cytochrome P450 aromatase (CYP19a) was analyzed by real-time quantitative PCR. The results showed that there was no significant alteration in the expression of VTGI, ERα, ERβ1, ERβ2 and CYP19a after 30 days of butachlor exposure, whereas the transcription of VTG II gene was significantly up-regulated in zebrafish exposed to 100 μg/L butachlor. It is suggested that butachlor may be a weak estrogen, and more endpoints need to be investigated to assess the effects of butachlor on the hypothalamus-pituitary-gonadal axis of zebrafish.

  13. Crosstalk between the IGF-1R/AKT/mTORC1 pathway and the tumor suppressors p53 and p27 determines cisplatin sensitivity and limits the effectiveness of an IGF-1R pathway inhibitor.

    Science.gov (United States)

    Davaadelger, Batzaya; Duan, Lei; Perez, Ricardo E; Gitelis, Steven; Maki, Carl G

    2016-05-10

    The insulin-like growth factor-1 receptor (IGF-1R) signaling pathway is aberrantly activated in multiple cancers and can promote proliferation and chemotherapy resistance. Multiple IGF-1R inhibitors have been developed as potential therapeutics. However, these inhibitors have failed to increase patient survival when given alone or in combination with chemotherapy agents. The reason(s) for the disappointing clinical effect of these inhibitors is not fully understood. Cisplatin (CP) activated the IGF-1R/AKT/mTORC1 pathway and stabilized p53 in osteosarcoma (OS) cells. p53 knockdown reduced IGF-1R/AKT/mTORC1 activation by CP, and IGF-1R inhibition reduced the accumulation of p53. These data demonstrate positive crosstalk between p53 and the IGF-1R/AKT/mTORC1 pathway in response to CP. Further studies showed the effect of IGF-1R inhibition on CP response is dependent on p53 status. In p53 wild-type cells treated with CP, IGF-1R inhibition increased p53s apoptotic function but reduced p53-dependent senescence, and had no effect on long term survival. In contrast, in p53-null/knockdown cells, IGF-1R inhibition reduced apoptosis in response to CP and increased long term survival. These effects were due to p27 since IGF-1R inhibition stabilized p27 in CP-treated cells, and p27 depletion restored apoptosis and reduced long term survival. Together, the results demonstrate 1) p53 expression determines the effect of IGF-1R inhibition on cancer cell CP response, and 2) crosstalk between the IGF-1R/AKT/mTORC1 pathway and p53 and p27 can reduce cancer cell responsiveness to chemotherapy and may ultimately limit the effectiveness of IGF-1R pathway inhibitors in the clinic. PMID:27050276

  14. Proton pump inhibitors

    Science.gov (United States)

    Proton pump inhibitors (PPIs) are medicines that work by reducing the amount of stomach acid made by ... Proton pump inhibitors are used to: Relieve symptoms of acid reflux, or gastroesophageal reflux disease (GERD). This ...

  15. Effect of prenatal androgen receptor antagonist or aromatase inhibitor on the differentiation of neuronal Fos responses to estrous female pheromones in the rat accessory olfactory system

    OpenAIRE

    Dominguez, Emilio; Portillo, Wendy; Baum, Michael J.; Bakker, Julie; Paredes, Raul

    2002-01-01

    Many socially relevant odors are detected in rodent species by the vomeronasal organ and subsequently processed by the accessory olfactory system (AOS). We previously found that gonadectomized male and female rats treated in adulthood with testosterone propionate (TP) showed equivalent Fos responses in the AOS to odors derived from estrous females. Likewise, in contrast with numerous other mammalian species, gonadectomized female rats show surprisingly high levels of male-typical mounting beh...

  16. In vitro and in vivo models for the evaluation of new inhibitors of human steroid sulfatase, devoid of residual estrogenic activity.

    Science.gov (United States)

    Shields-Botella, J; Bonnet, P; Duc, I; Duranti, E; Meschi, S; Cardinali, S; Prouheze, P; Chaigneau, A M; Duranti, V; Gribaudo, S; Rivière, A; Mengual, L; Carniato, D; Cecchet, L; Lafay, J; Rondot, B; Sandri, J; Pascal, J C; Delansorne, R

    2003-02-01

    The goal of our research project is to develop a new class of orally active drugs, estrone sulfatase inhibitors, for the treatment of estrogen-dependent (receptor positive) breast cancer. Several compounds were synthesized and their pharmacological potencies explored. Based on encouraging preliminary results, three of them, TX 1299, TX 1492 and TX 1506 were further studied in vitro as well as in vivo. They proved to be strong inhibitors of estrone sulfatase when measured on the whole human JEG-3 choriocarcinoma and MCF-7 breast cancer cells and their IC(50)s found to be in the range of known standard inhibitors. Their residual estrogenic activity was checked as negative in the test of induction of alkaline phosphatase (APase) activity in whole human endometrial adenocarcinoma Ishikawa cells. In addition, their effect on aromatase activity in JEG-3 cells was also examined, since the goal of inhibiting both sulfatase and aromatase activities appears very attractive. However, it has been unsuccessful so far. Then, in vivo potencies of TX 1299, the lead compound in our chemical series, were evaluated in comparison with 6,6,7-COUMATE, a non-steroidal standard, in two different rat models and by oral route. First, the absence of any residual estrogenic activity for these compounds was checked in the uterotrophic model in prepubescent female rats. Second, antiuterotrophic activity in adult ovariectomized rat supplemented with estrone sulfate (E(1)S), showed that both compounds were potent inhibitors, the power of TX 1299 relative to 6,6,7-COUMATE being around 80%. This assay was combined with uterine sulfatase level determination and confirmed the complete inhibition of this enzyme within the target organ. Preliminary studies indicated that other non-steroid compounds in the Théramex series were potent in vitro and in vivo inhibitors of estrone sulfatase in rats and further studies are in progress.

  17. Effects of phenol on ovarian P450arom gene expression and aromatase activity in vivo and antioxidant metabolism in common carp Cyprinus carpio.

    Science.gov (United States)

    Das, Sumana; Majumder, Suravi; Gupta, Shreyasi; Dutta, Sharmistha; Mukherjee, Dilip

    2016-02-01

    Ovarian cyp19a mRNA expression and P450 aromatase activity were measured in vivo in common carp Cyprinus carpio exposed to phenol for 96 h. Production of reactive oxygen species (ROS) and parameters of antioxidant defense system in serum ovary and liver of this fish after long-term phenol exposure were also studied. In vivo exposure of fish to sublethal dose of phenol for 96 h caused marked attenuation of ovarian cyp19a1a gene expression and P450 aromatase activity. Production of ROS like hydrogen peroxide and hydroxyl radicals in serum, liver and ovary in fish exposed to phenol for 15 days elevated significantly from day 1 to day 7 with no further significant increase thereafter compared to their respective control values. Total superoxide dismutase (SOD) and catalase activities in serum and ovary decreased gradually and significantly from day 1 to day 4, which then increased significantly for the rest of the exposure days. Liver SOD activity seemed to be distinctly responsive to phenol. SOD activity in liver of phenol-exposed fish started to increase gradually from day 1 to 4 with no further increase thereafter. Catalase activities in all the tissues showed significant inhibition up to day 4 which then increased gradually and significantly up to day 15 of phenol exposure compared to their respective control values. From our results, it appears that sublethal dose of phenol has the endocrine disruptive potential and effect is mediated via inhibition of ovarian P450arom gene expression and aromatase activity in vivo. Sublethal dose of phenol also caused oxidative stress, and antioxidant systems are very much effective to prevent the damages caused by the generation of ROS.

  18. Cyclin A1 and P450 Aromatase Promote Metastatic Homing and Growth of Stem-like Prostate Cancer Cells in the Bone Marrow.

    Science.gov (United States)

    Miftakhova, Regina; Hedblom, Andreas; Semenas, Julius; Robinson, Brian; Simoulis, Athanasios; Malm, Johan; Rizvanov, Albert; Heery, David M; Mongan, Nigel P; Maitland, Norman J; Allegrucci, Cinzia; Persson, Jenny L

    2016-04-15

    Bone metastasis is a leading cause of morbidity and mortality in prostate cancer. While cancer stem-like cells have been implicated as a cell of origin for prostate cancer metastasis, the pathways that enable metastatic development at distal sites remain largely unknown. In this study, we illuminate pathways relevant to bone metastasis in this disease. We observed that cyclin A1 (CCNA1) protein expression was relatively higher in prostate cancer metastatic lesions in lymph node, lung, and bone/bone marrow. In both primary and metastatic tissues, cyclin A1 expression was also correlated with aromatase (CYP19A1), a key enzyme that directly regulates the local balance of androgens to estrogens. Cyclin A1 overexpression in the stem-like ALDH(high) subpopulation of PC3M cells, one model of prostate cancer, enabled bone marrow integration and metastatic growth. Further, cells obtained from bone marrow metastatic lesions displayed self-renewal capability in colony-forming assays. In the bone marrow, cyclin A1 and aromatase enhanced local bone marrow-releasing factors, including androgen receptor, estrogen and matrix metalloproteinase MMP9 and promoted the metastatic growth of prostate cancer cells. Moreover, ALDH(high) tumor cells expressing elevated levels of aromatase stimulated tumor/host estrogen production and acquired a growth advantage in the presence of host bone marrow cells. Overall, these findings suggest that local production of steroids and MMPs in the bone marrow may provide a suitable microenvironment for ALDH(high) prostate cancer cells to establish metastatic growths, offering new approaches to therapeutically target bone metastases. Cancer Res; 76(8); 2453-64. ©2016 AACR. PMID:26921336

  19. PARP Inhibitors for the Treatment and Prevention of Breast Cancer

    OpenAIRE

    Vinayak, Shaveta; Ford, James M.

    2010-01-01

    Poly (ADP-ribose) polymerase (PARP) inhibitors, a novel class of drugs that target tumors with DNA repair defects, have received tremendous enthusiasm. Early preclinical studies identified BRCA1 and BRCA2 tumors to be highly sensitive to PARP inhibitors as a result of homologous recombination defect. Based on this premise, PARP inhibitors have been tested in early phase clinical trials as a single agent in BRCA1 or BRCA2 mutation carriers and in combination with chemotherapy in triple-negativ...

  20. Expression Patterns of Cytochrome P450 Aromatase Genes During Ovary Development and Their Responses to Temperature Stress in Female Yellow Catfish (Pelteobagrus fulvidraco)

    Institute of Scientific and Technical Information of China (English)

    LIU Miao; QI Baoxia; WEN Haishen; HE Feng; LI Jifang; SHI Dan; HU Jian; ZHANG Yuanqing; MA Ruiqin; MU Weijie

    2011-01-01

    Cytochrome P450 aromatase (P450arom) plays a pivotal role in ovary development.In this study,we used semi-quantitative reverse transcription PCR (RT-PCR) to analyze spatiotemporal expressions of two P450arom genes (CYP1gA and CYP19B)and their responses to temperature stress in female yellow catfish (Pelteobagrusfulvidraco).Tissue distribution pattern of CYP19showed that CYP19B was abundantly expressed in fish brain and ovary (brain>ovary),but weakly in intestines,whereas CYP19Awas exclusively expressed in ovary.Semi-quantitative RT-PCR analyses showed high transcript abundance of both CYP19A and CYP19B in the ovarian reproductive cycle,corresponding with serum estradiol-17β (E2) levels.Increases in aromatases,serum E2 and testosterone (T) levels in fish exposed to higher temperature indicated stimulation of ovarian maturation and recrudescence by heat stress in stages Ⅱ and V during the ovarian cycle,whereas associated decreases in stage III suggested vitellogenesis inhibition by heat stress.Gene expression of CYP19 was closely related to levels of serum E2.Results demonstrated CYP19 played a crucial role in the reproductive cycle of female yellow catfish.Different temperature stress affected CYP19 gene expression in the fish ovarian reproductive cycle.Associated P450arom genes could be useful for studying physiological aspects of yellow catfish.

  1. Effect of Yikun Neiyi Wan on the Expression of Aromatase P450,COX-2, and ER Related Receptor in Endometrial Cells in Vitro from Patients with Endometriosis

    Institute of Scientific and Technical Information of China (English)

    WANG Qing; ZHAO Hong; XIANG Qing; JU Hai; HAN Shu-min; WANG Ling-yan; XU Bo

    2009-01-01

    Objective: To investigate the effect of Yikun Neiyi Wan (益坤内异丸 YKNYW) and gestrinone on the expression of aromatase P450 (P450arom), cyclo-oxygenase-2 (COX-2) and estrogen receptor (ER) in isolated ectopic and normal endometrial stroma cells in vitro. Methods: Digestion and serial filtration were used to isolate and culture the ectopic and eutopic endometrial cells from patients with chocolate cyst in virto. Transformation of the cell morphology was observed in a inverted microscope. The effect of YKNYW on the expression of aromatase P450, cyclo-oxygenase-2, estrogen receptor in cultured endometriosis cells were detected by immunohistochemical method. Results: The expression levels of P450arom, COX-2 in glandular epithelium cells in vitro were decreased significantly by YKNYW compared with gestrinone (P<0.05). ER expression in mesenchymal cells of endometriosis was increased by YKNYW in the large and medium dosage groups compared with gestrinone. Conclusion: The mechanism by which YKNYW alleviates endometriosis pain is possibly related to the decrease in ectopic endometrial P450 arom and COX-2 expression in glandular epithelium, contrary to gestrinone, and the increase in ER expression in mesenchymalis, consistent with gestrione in patients with endometriosis.

  2. The sequence of the CA-SP1 junction accounts for the differential sensitivity of HIV-1 and SIV to the small molecule maturation inhibitor 3-O-{3',3'-dimethylsuccinyl}-betulinic acid

    Directory of Open Access Journals (Sweden)

    Aiken Christopher

    2004-06-01

    Full Text Available Abstract Background Despite the effectiveness of currently available antiretroviral therapies in the treatment of HIV-1 infection, a continuing need exists for novel compounds that can be used in combination with existing drugs to slow the emergence of drug-resistant viruses. We previously reported that the small molecule 3-O-{3',3'-dimethylsuccinyl}-betulinic acid (DSB specifically inhibits HIV-1 replication by delaying the processing of the CA-SP1 junction in Pr55Gag. By contrast, SIVmac239 replicates efficiently in the presence of high concentrations of DSB. To determine whether sequence differences in the CA-SP1 junction can fully account for the differential sensitivity of HIV-1 and SIV to DSB, we engineered mutations in this region of two viruses and tested their sensitivity to DSB in replication assays using activated human primary CD4+ T cells. Results Substitution of the P2 and P1 residues of HIV-1 by the corresponding amino acids of SIV resulted in strong resistance to DSB, but the mutant virus replicated with reduced efficiency. Conversely, replication of an SIV mutant containing three amino acid substitutions in the CA-SP1 cleavage site was highly sensitive to DSB, and the mutations resulted in delayed cleavage of the CA-SP1 junction in the presence of the drug. Conclusions These results demonstrate that the CA-SP1 junction in Pr55Gag represents the primary viral target of DSB. They further suggest that the therapeutic application of DSB will be accompanied by emergence of mutant viruses that are highly resistant to the drug but which exhibit reduced fitness relative to wild type HIV-1.

  3. Melatonin Sensitizes H1975 Non-Small-Cell Lung Cancer Cells Harboring a T790M-Targeted Epidermal Growth Factor Receptor Mutation to the Tyrosine Kinase Inhibitor Gefitinib

    Directory of Open Access Journals (Sweden)

    Miyong Yun

    2014-08-01

    Full Text Available Background/Aims: The use of tyrosine kinase inhibitors (TKIs to target active epidermal growth factor receptor (EGFR-harbouring mutations has been effective in patients with advanced non-small-cell lung cancer (NSCLC. However, the use of TKIs in NSCLS patients with somatic EGFR mutations, particularly T790M, causes drug resistance. Thus, in the present study, we investigated overcoming resistance against the TKI gefitinib by combination treatment with melatonin in H1975 NSCLC cells harbouring the T790M somatic mutation. Methods: H1975 and HCC827 cells were treated with melatonin in combination with gefitinib, and cell viability, cell cycle progression, apoptosis, and EGFR, AKT, p38, Bcl-2, Bcl-xL, caspase 3 and Bad protein levels were examined. Results: Treatment with melatonin dose-dependently decreased the viability of H1975 cells harbouring the T790M somatic mutation compared to HCC827 cells with an EGFR active mutation. Melatonin-mediated cell death resulted in decreased phosphorylation of EGFR and Akt, leading to attenuated expression of survival proteins, such as Bcl-2, Bcl-xL and survivin, and activated caspase 3 in H1975 cells, but not in HCC827 cells. However, we did not observe a significant change in expression of cell cycle proteins, such as cyclin D, cyclin A, p21 and CDK4 in H1975 cells. Surprisingly, co-treatment of gefitinib with melatonin effectively decreased the viability of H1975 cells, but not HCC827 cells. Moreover, co-treatment of H1975 cells caused consistent down-regulation of EGFR phosphorylation and induced apoptosis compared to treatment with gefitinib or melatonin alone. Conclusions: Our findings demonstrate that melatonin acts as a potent chemotherapeutic agent by sensitising to gefitinib TKI-resistant H1975 cells that harbour a EGFR T790M mutation.

  4. Efficacy of Epidermal Growth Factor Receptor-Tyrosine Kinase Inhibitors for Advanced Squamous Cell Lung Carcinoma Patients with Sensitive EGFR Mutations%EGFR-TKI治疗EGFR敏感突变的晚期肺鳞癌的疗效分析

    Institute of Scientific and Technical Information of China (English)

    刘咏梅; 赵倩; 唐源; 张衍; 李艳莹; 王永生; 卢铀

    2015-01-01

    目的 探讨表皮生长因子酪氨酸激酶抑制剂(Epidermal growth factor receptor-tyrosine kinase inhibitor,EGFR-TKI)治疗EGFR敏感突变的晚期肺鳞癌患者的疗效.方法 收集20例四川大学华西医院经病理确诊、EGFR检测敏感突变、并接受EGFR-TKI治疗的Ⅳ期或术后复发转移肺鳞癌患者,分析其与EGFR-TKI的疗效关系.结果 20例EGFR敏感突变的晚期鳞癌患者接受EGFR-TKI治疗,随访资料完整.10例19-del(+),8例L858R(+),1例同时存在外显子21(L858R)点突变和外显子20(T790M)突变,1例外显子18(G719X)突变.其中部分缓解(PR)9例,疾病稳定(SD)7例,疾病进展(PD)4例.客观缓解率(ORR) 45%,疾病控制率80%,中位无进展生存期(mPFS)为5.0月,中位生存期(mOS)为14.7月.结论 EGFR-TKI对部分EGFR敏感突变的鳞癌患者有一定疗效.在临床工作中,应重视这部分患者的EGFR基因检测,以便明确获益的患者.

  5. Sensitivity analysis

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003741.htm Sensitivity analysis To use the sharing features on this page, please enable JavaScript. Sensitivity analysis determines the effectiveness of antibiotics against microorganisms (germs) ...

  6. 非小细胞肺癌中微小RNA与表皮生长因子受体-酪氨酸激酶抑制剂敏感性关系的研究进展%MicroRNAs and epidermal growth factor receptor-tyrosine kinase inhibitors sensitivity in non-small cell lung cancer

    Institute of Scientific and Technical Information of China (English)

    裴冬; 陈晓锋; 束永前

    2012-01-01

    表皮生长因子受体(epidermal growth factor receptor,EGFR) -酪氨酸激酶抑制剂(tyrosine kinase inhibitor,TKI)被广泛应用于肿瘤的治疗,尤其是伴有EGFR基因突变的非小细胞肺癌(non-small cell lung cancer,NSCLC)的治疗,但EGFR- TKI耐药性的产生已成为制约其疗效的主要瓶颈.微小RNA (microRNAs,miRNAs)是一类非编码小分子RNA,在转录后水平调控基因的表达.近年来的研究发现,miRNAs在多个环节参与调节NSCLC对EGFR-TKI的敏感性,提示其可能在TKI耐药中扮演了重要角色,并有可能成为一种新的预测TKI敏感性的生物学标志物.因此,本文就有关NSCLC对EGFR-TKI的敏感性与miRNAs之间关系的最新研究进展进行综述.%Epidermal growth factor receptor-tyrosine kinase inhibitors (ECFR-TKIs) have been wildly used in cancer treatment, especially in non-small cell lung cancer (NSCLC) with EGFR mutation. However, the resistance to EGFR-TKIs has been a major problem which has resulted in a limitation for therapeutic effectiveness of ECFR-TKIs. MiRNAs (microRNAs) are a group of small non-coding RNAs, which are involved in the post-transcriptional regulation of gene expression. More recently, miRNAs have also been found to be involved in the regulation of EGFR-TKIs sensitivity in the treatment of NSCLC through multiple pathways, it suggests that EGFR-TKIs may play an important role in the resistance to TKI and it may be used as a new biomarker in the prediction of TKI sensitivity. This review summarizes the advance in the relationship between miRNAs and EGFR-TKI sensitivity in NSCLC.

  7. Plasma concentrations of estradiol and testosterone, gonadal aromatase activity and ultrastructure of the testis in Xenopus laevis exposed to estradiol or atrazine

    International Nuclear Information System (INIS)

    The ultrastructure of testicular cells of adult male African clawed frogs (Xenopus laevis) exposed to either estradiol (0.1 μg/L) or 2-chloro-4-ethylamino-6-isopropyl-amino-s-triazine (atrazine; 10 or 100 μg/L) was examined by electron microscopy and compared to plasma concentrations of the steroid hormones, testosterone (T) and estradiol (E2), testicular aromatase activity and gonad growth expressed as the gonado-somatic index (GSI). Exposure to E2 caused significant changes both at the sub-cellular and biochemical levels. Exposure to E2 resulted in significantly fewer sperm cells, inhibition of meiotic division of germ cells, more lipid droplets that are storage compartments for the sex steroid hormone precursor cholesterol, and lesser plasma T concentrations. Although not statistically significant, frogs exposed to E2 had slightly smaller GSI values. These results may be indicative of an inhibition of gonad growth and disrupted germ cell development by E2. Concentrations of E2 in plasma were greater in frogs exposed to E2 in water. Exposure to neither concentration of atrazine caused effects on germ cell development, testicular aromatase activity or plasma hormone concentrations. These results suggest that atrazine does not affect testicular function. In contrast, exposure of male X. laevis to E2 led to sub-cellular events that are indicative of disruption of testicular development, and demasculinization processes (decrease of androgen hormone titers). These results indicate that atrazine does not cause responses that are similar to those caused by exposure to E2

  8. A polymorphism at the 3'-UTR region of the aromatase gene defines a subgroup of postmenopausal breast cancer patients with poor response to neoadjuvant letrozole

    Directory of Open Access Journals (Sweden)

    Albaladejo Carlos

    2010-02-01

    Full Text Available Abstract Background Aromatase (CYP19A1 regulates estrogen biosynthesis. Polymorphisms in CYP19A1 have been related to the pathogenesis of breast cancer (BC. Inhibition of aromatase with letrozole constitutes the best option for treating estrogen-dependent BC in postmenopausal women. We evaluate a series of polymorphisms of CYP19A1 and their effect on response to neoadjuvant letrozole in early BC. Methods We analyzed 95 consecutive postmenopausal women with stage II-III ER/PgR [+] BC treated with neoadjuvant letrozole. Response to treatment was measured by radiology at 4th month by World Health Organization (WHO criteria. Three polymorphisms of CYP19A1, one in exon 7 (rs700519 and two in the 3'-UTR region (rs10046 and rs4646 were evaluated on DNA obtained from peripheral blood. Results Thirty-five women (36.8% achieved a radiological response to letrozole. The histopathological and immunohistochemical parameters, including hormonal receptor status, were not associated with the response to letrozole. Only the genetic variants (AC/AA of the rs4646 polymorphism were associated with poor response to letrozole (p = 0.03. Eighteen patients (18.9% reported a progression of the disease. Those patients carrying the genetic variants (AC/AA of rs4646 presented a lower progression-free survival than the patients homozygous for the reference variant (p = 0.0686. This effect was especially significant in the group of elderly patients not operated after letrozole induction (p = 0.009. Conclusions Our study reveals that the rs4646 polymorphism identifies a subgroup of stage II-III ER/PgR [+] BC patients with poor response to neoadjuvant letrozole and poor prognosis. Testing for the rs4646 polymorphism could be a useful tool in order to orientate the treatment in elderly BC patients.

  9. Glycine Transporters and Their Inhibitors

    Science.gov (United States)

    Gilfillan, Robert; Kerr, Jennifer; Walker, Glenn; Wishart, Grant

    Glycine plays a ubiquitous role in many biological processes. In the central nervous system it serves as an important neurotransmitter acting as an agonist at strychnine-sensitive glycine receptors and as an essential co-agonist with glutamate at the NMDA receptor complex. Control of glycine concentrations in the vicinity of these receptors is mediated by the specific glycine transporters, GlyT1 and GlyT2. Inhibition of these transporters has been postulated to be of potential benefit in several therapeutic indications including schizophrenia and pain. In this review we discuss our current knowledge of glycine transporters and focus on recent advances in the medicinal chemistry of GlyT1 and GlyT2 inhibitors.

  10. Sensitivity analysis

    International Nuclear Information System (INIS)

    General remarks on sensitivity analysis, the study of changes in a model output produced by varying model inputs, are made first. Sampling methods are discussed, and three sensitivity measures: partial rank correlation, derivative or response surface, and partial variance are described. Some sample results for a 16-input, 13-output hydrodynamics model are given. Both agreement and disagreement were found among the sensitivity measures. 4 figures

  11. Cholinesterase inhibitors from botanicals

    Directory of Open Access Journals (Sweden)

    Faiyaz Ahmed

    2013-01-01

    Full Text Available Alzheimer′s disease (AD is a progressive neurodegenerative disease, wherein a progressive loss of cholinergic synapses occurs in hippocampus and neocortex. Decreased concentration of the neurotransmitter, acetylcholine (ACh, appears to be critical element in the development of dementia, and the most appropriate therapeutic approach to treat AD and other form of dementia is to restore acetylcholine levels by inhibiting both major form of cholinesterase: Acetylcholinesterase (AChE and butyrylcholinesterase (BChE. Consequently, researches have focused their attention towards finding cholinesterase inhibitors from natural products. A large number of such inhibitors have been isolated from medicinal plants. This review presents a comprehensive account of the advances in field of cholinesterase inhibitor phytoconstituents. The structures of some important phytoconstituents (collected through www.Chemspider.com are also presented and the scope for future research is discussed.

  12. Gluten Sensitivity

    Science.gov (United States)

    Gluten is a protein found in wheat, rye, and barley. It is found mainly in foods but ... products like medicines, vitamins, and supplements. People with gluten sensitivity have problems with gluten. It is different ...

  13. Sunflower trypsin inhibitor-1.

    Science.gov (United States)

    Korsinczky, Michael L J; Schirra, Horst Joachim; Craik, David J

    2004-10-01

    SFTI-1 is a bicyclic 14 amino acid peptide that was originally isolated from the seeds of the sunflower Helianthus annuus. It is a potent inhibitor of trypsin, with a sub-nanomolar K(i) value and is homologous to the active site region of the well-known family of serine protease inhibitors known as the Bowman-Birk trypsin inhibitors. It has a cyclic backbone that is cross-braced by a single disulfide bridge and a network of hydrogen bonds that result in a well-defined structure. SFTI-1 is amenable to chemical synthesis, allowing for the creation of synthetic variants. Alterations to the structure such as linearising the backbone or removing the disulfide bridge do not reduce the potency of SFTI-1 significantly, and minimising the peptide to as few as nine residues results in only a small decrease in reactivity. The creation of linear variants of SFTI-1 also provides a tool for investigating putative linear precursor peptides. The mechanism of biosynthesis of SFTI-1 is not yet known but it seems likely that it is a gene-coded product that has arisen from a precursor protein that may be evolutionarily related to classic Bowman-Birk inhibitors. PMID:15544530

  14. Inhibitors of histone demethylases

    DEFF Research Database (Denmark)

    Lohse, Brian; Kristensen, Jesper L; Kristensen, Line H;

    2011-01-01

    Methylated lysines are important epigenetic marks. The enzymes involved in demethylation have recently been discovered and found to be involved in cancer development and progression. Despite the relative recent discovery of these enzymes a number of inhibitors have already appeared. Most of the i...

  15. Inhibitors of histone deacetylase

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to compounds of formula (I) or a pharmaceutically acceptable salt, hydrate, solvate, or prodrug thereof, wherein X1, X2, X3, X4, X5, W1, W2, W3, and W4 are as described. The present invention relates generally to inhibitors of histone deacetylase and to methods...

  16. Climate sensitivity

    OpenAIRE

    Roy THOMPSON

    2015-01-01

    Earth has been habitable through most of its history, but the anthropogenically mediated greenhouse effect, if sufficiently strong, can threaten Earth's long-standing equability. This paper's main aim is to determine the strength of the anthropogenic greenhouse effect (the climate sensitivity) from observational data and basic physics alone, without recourse to the parameterisations of earth-system models and their inevitable uncertainties. A key finding is that the sensitivity can be constra...

  17. Discovery of novel AKT inhibitors with enhanced anti-tumor effects in combination with the MEK inhibitor.

    Directory of Open Access Journals (Sweden)

    Melissa Dumble

    Full Text Available Tumor cells upregulate many cell signaling pathways, with AKT being one of the key kinases to be activated in a variety of malignancies. GSK2110183 and GSK2141795 are orally bioavailable, potent inhibitors of the AKT kinases that have progressed to human clinical studies. Both compounds are selective, ATP-competitive inhibitors of AKT 1, 2 and 3. Cells treated with either compound show decreased phosphorylation of several substrates downstream of AKT. Both compounds have desirable pharmaceutical properties and daily oral dosing results in a sustained inhibition of AKT activity as well as inhibition of tumor growth in several mouse tumor models of various histologic origins. Improved kinase selectivity was associated with reduced effects on glucose homeostasis as compared to previously reported ATP-competitive AKT kinase inhibitors. In a diverse cell line proliferation screen, AKT inhibitors showed increased potency in cell lines with an activated AKT pathway (via PI3K/PTEN mutation or loss while cell lines with activating mutations in the MAPK pathway (KRAS/BRAF were less sensitive to AKT inhibition. Further investigation in mouse models of KRAS driven pancreatic cancer confirmed that combining the AKT inhibitor, GSK2141795 with a MEK inhibitor (GSK2110212; trametinib resulted in an enhanced anti-tumor effect accompanied with greater reduction in phospho-S6 levels. Taken together these results support clinical evaluation of the AKT inhibitors in cancer, especially in combination with MEK inhibitor.

  18. Discovery of novel AKT inhibitors with enhanced anti-tumor effects in combination with the MEK inhibitor.

    Science.gov (United States)

    Dumble, Melissa; Crouthamel, Ming-Chih; Zhang, Shu-Yun; Schaber, Michael; Levy, Dana; Robell, Kimberly; Liu, Qi; Figueroa, David J; Minthorn, Elisabeth A; Seefeld, Mark A; Rouse, Meagan B; Rabindran, Sridhar K; Heerding, Dirk A; Kumar, Rakesh

    2014-01-01

    Tumor cells upregulate many cell signaling pathways, with AKT being one of the key kinases to be activated in a variety of malignancies. GSK2110183 and GSK2141795 are orally bioavailable, potent inhibitors of the AKT kinases that have progressed to human clinical studies. Both compounds are selective, ATP-competitive inhibitors of AKT 1, 2 and 3. Cells treated with either compound show decreased phosphorylation of several substrates downstream of AKT. Both compounds have desirable pharmaceutical properties and daily oral dosing results in a sustained inhibition of AKT activity as well as inhibition of tumor growth in several mouse tumor models of various histologic origins. Improved kinase selectivity was associated with reduced effects on glucose homeostasis as compared to previously reported ATP-competitive AKT kinase inhibitors. In a diverse cell line proliferation screen, AKT inhibitors showed increased potency in cell lines with an activated AKT pathway (via PI3K/PTEN mutation or loss) while cell lines with activating mutations in the MAPK pathway (KRAS/BRAF) were less sensitive to AKT inhibition. Further investigation in mouse models of KRAS driven pancreatic cancer confirmed that combining the AKT inhibitor, GSK2141795 with a MEK inhibitor (GSK2110212; trametinib) resulted in an enhanced anti-tumor effect accompanied with greater reduction in phospho-S6 levels. Taken together these results support clinical evaluation of the AKT inhibitors in cancer, especially in combination with MEK inhibitor.

  19. Estrogen receptor and aromatase expression in gingival carcinoma tissue%雌激素受体及芳香化酶在牙龈癌组织中的表达和意义

    Institute of Scientific and Technical Information of China (English)

    王秋锐; 杨健; 赵华平; 张英怀

    2015-01-01

    AIM:To investigate the expression of estrogen receptor (ER)and aromatase in gingival carcino-ma.METHODS:ER and aromatase were detected by immunohistochemical staining SP method in gingival carcinoma (n=28)and normal gingival tissues(n=15).RESULTS:Positive expression rates of ER and aromatase expression in gingival carcinoma were 50.00% and 42.86% ,in normal gingival tissues were 13.33% and 6.67%,respectively (P<0.05).No significant correlation was found between ER and aromatase in gingival carcinoma.CONCLUSION:Estrogen metablism might be related to gingival carcinoma.Aromatase is not the exclusive reason of the high positive rate of ER.%目的:观察牙龈癌中雌激素受体(ER)与芳香化酶的表达情况,探讨局部雌激素及芳香化酶在牙龈癌中的作用与关系。方法:免疫组化过氧化物酶标记的链酶卵白素法测定雌激素受体及芳香化酶在牙龈癌中的表达。结果:牙龈癌组雌激素受体及芳香化酶的表达阳性率分别为50%和42.86%,正常对照组分别为13.33%和6.67%(P<0.05);牙龈癌中雌激素受体与芳香化酶之间未见明显相关性。结论:牙龈癌有一定的雌激素依赖性;芳香化酶在牙龈癌组织中表达升高,但芳香化酶并不是影响局部雌激素受体升高的唯一因素。

  20. Path Sensitization

    Institute of Scientific and Technical Information of China (English)

    赵著行; 闵应骅; 等

    1997-01-01

    For different delay models,the concept of sensitization can be very different.Traditonal concepts of sensitization cannot precisely describe circuit behavior when the input vectors change very fast.Using Boolean process aporoach,this paper presents a new definition of sensitization for arbitrary input waveforms.By this new concept it is found that if the inputs of a combinational circuit can change at any time,and each gate's delay varies within an interval (bounded gate delay model),then every path,which is not necessarily a single topological path,is sensitizable.From the experimental results it can be seen that,all nonsensitizable paths for traditional concepts actually can propagate transitions along them for some input waveforms.However,specified time between input transitions(STBIT) and minimum permissible pulse width(ε)are two major factors to make some paths non-sensitizable.

  1. [JAK2 inhibitors].

    Science.gov (United States)

    Hernández Boluda, Juan Carlos; Gómez, Montse; Pérez, Ariadna

    2016-07-15

    Pharmacological inhibition of the kinase activity of JAK proteins can interfere with the signaling of immunomodulatory cytokines and block the constitutive activation of the JAK-STAT pathway that characterizes certain malignancies, including chronic myeloproliferative neoplasms. JAK inhibitors may, therefore, be useful to treat malignancies as well as inflammatory or immune disorders. Currently, the most significant advances have been made in the treatment of myelofibrosis, where these drugs may lead to a remarkable improvement in the control of hyperproliferative manifestations. However, available data suggest that this treatment is not curative of myelofibrosis. In general, JAK2 inhibition induces cytopaenias, with this being considered a class side-effect. By contrast, the extrahaematologic toxicity profile varies significantly among the different JAK inhibitors. At present, there are several clinical trials evaluating the combination of ruxolitinib with other drugs, in order to improve its therapeutic activity as well as reducing haematologic toxicity. PMID:27033437

  2. Alpha glucosidase inhibitors.

    Science.gov (United States)

    Kalra, Sanjay

    2014-04-01

    Alpha glucosidase inhibitors (AGIs) are a unique class of anti-diabetic drugs. Derived from bacteria, these oral drugs are enzyme inhibitors which do not have a pancreato -centred mechanism of action. Working to delay carbohydrate absorption in the gastrointestinal tract, they control postprandial hyperglycaemia and provide unquestioned cardiovascular benefit. Specially suited for a traditional Pakistani carbohydrate-rich diet, AGIs have been termed the 'untapped diamonds' of diabetology. The use of these oral antidiabetic drugs (OADs) that target pathophysiology in the early stages of type 2 diabetes, notably to reduce postprandial hyperglycaemia and hyperinsulinaemia will inevitably increase with time. This review describes the history of their development, mechanism of action, basic and clinical pharmacology, and suggests practical, evidence-based guidance for their optimal use. PMID:24864650

  3. Coagulation inhibitors in inflammation.

    Science.gov (United States)

    Esmon, C T

    2005-04-01

    Coagulation is triggered by inflammatory mediators in a number of ways. However, to prevent unwanted clot formation, several natural anticoagulant mechanisms exist, such as the antithrombin-heparin mechanism, the tissue factor pathway inhibitor mechanism and the protein C anticoagulant pathway. This review examines the ways in which these pathways are down-regulated by inflammation, thus limiting clot formation and decreasing the natural anti-inflammatory mechanisms that these pathways possess. PMID:15787615

  4. Osteocompatibility of Biofilm Inhibitors

    OpenAIRE

    Rawson, Monica; Haggard, Warren; Jennings, Jessica A.

    2014-01-01

    The demand for infection prevention therapies has led to the discovery of several biofilm inhibitors. These inhibiting signals are released by bacteria, fungi, or marine organisms to signal biofilm dispersal or disruption in Gram-positive, Gram-negative, and fungal microorganisms. The purpose of this study was to test the biocompatibility of five different naturally-produced biofilm chemical dispersal and inhibition signals with osteoblast-like cells: D-amino acids (D-AA), lysostaphin (LS), f...

  5. Chronic green tea consumption decreases body mass, induces aromatase expression, and changes proliferation and apoptosis in adult male rat adipose tissue.

    Science.gov (United States)

    Monteiro, Rosário; Assunção, Marco; Andrade, José P; Neves, Delminda; Calhau, Conceição; Azevedo, Isabel

    2008-11-01

    Green tea (GT) and its components have been shown to possess antiobesity properties and the corresponding mechanisms of action are being investigated, given the epidemic proportions of obesity incidence. In the current work, we used 12-mo-old male Wistar rats to test the effect of 6 mo of treatment with GT as the sole drinking beverage (52.8 +/- 6.4 mL/d) on adipose tissue (AT). AT aromatase expression was determined by Western blotting, plasma concentrations of 17beta-estradiol and testosterone were determined by RIA, and adipocyte size determined by measuring diameter in tissue sections. Proliferation and apoptosis were also assessed by Ki67 immunostaining and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling, respectively. Evaluations were made in subcutaneous (sc) AT and visceral (v) AT. Body weight increased over time in both groups (P rats had a higher percentage of proliferating cells (204.1 +/- 19.5% of control in scAT, P adipocytes (78.3 +/- 1.7% of control in scAT, P < 0.001, and 87.9 +/- 3.2% of control in vAT, P < 0.05). GT also increased the number of apoptotic cells in vAT (320.4 +/- 21.9% of control; P < 0.001). These results suggest new mechanisms for GT on body weight and highlight its potential benefit to prevent or treat obesity and the metabolic syndrome. PMID:18936213

  6. SMAC mimetic Debio 1143 synergizes with taxanes, topoisomerase inhibitors and bromodomain inhibitors to impede growth of lung adenocarcinoma cells.

    Science.gov (United States)

    Langdon, Casey G; Wiedemann, Norbert; Held, Matthew A; Mamillapalli, Ramanaiah; Iyidogan, Pinar; Theodosakis, Nicholas; Platt, James T; Levy, Frederic; Vuagniaux, Gregoire; Wang, Shaomeng; Bosenberg, Marcus W; Stern, David F

    2015-11-10

    Targeting anti-apoptotic proteins can sensitize tumor cells to conventional chemotherapies or other targeted agents. Antagonizing the Inhibitor of Apoptosis Proteins (IAPs) with mimetics of the pro-apoptotic protein SMAC is one such approach. We used sensitization compound screening to uncover possible agents with the potential to further sensitize lung adenocarcinoma cells to the SMAC mimetic Debio 1143. Several compounds in combination with Debio 1143, including taxanes, topoisomerase inhibitors, and bromodomain inhibitors, super-additively inhibited growth and clonogenicity of lung adenocarcinoma cells. Co-treatment with Debio 1143 and the bromodomain inhibitor JQ1 suppresses the expression of c-IAP1, c-IAP2, and XIAP. Non-canonical NF-κB signaling is also activated following Debio 1143 treatment, and Debio 1143 induces the formation of the ripoptosome in Debio 1143-sensitive cell lines. Sensitivity to Debio 1143 and JQ1 co-treatment was associated with baseline caspase-8 expression. In vivo treatment of lung adenocarcinoma xenografts with Debio 1143 in combination with JQ1 or docetaxel reduced tumor volume more than either single agent alone. As Debio 1143-containing combinations effectively inhibited both in vitro and in vivo growth of lung adenocarcinoma cells, these data provide a rationale for Debio 1143 combinations currently being evaluated in ongoing clinical trials and suggest potential utility of other combinations identified here.

  7. Design of highly potent urea-based, exosite-binding inhibitors selective for glutamate carboxypeptidase II.

    Science.gov (United States)

    Tykvart, Jan; Schimer, Jiří; Jančařík, Andrej; Bařinková, Jitka; Navrátil, Václav; Starková, Jana; Šrámková, Karolína; Konvalinka, Jan; Majer, Pavel; Šácha, Pavel

    2015-05-28

    We present here a structure-aided design of inhibitors targeting the active site as well as exosites of glutamate carboxypeptidase II (GCPII), a prostate cancer marker, preparing potent and selective inhibitors that are more than 1000-fold more active toward GCPII than its closest human homologue, glutamate carboxypeptidase III (GCPIII). Additionally, we demonstrate that the prepared inhibitor conjugate can be used for sensitive and selective imaging of GCPII in mammalian cells. PMID:25923815

  8. Sensitive innovation

    DEFF Research Database (Denmark)

    Søndergaard, Katia Dupret

    definition developed by Schumpeter that defines innovation as an effort by one or more individuals to create economic profit through a qualitative change by Schumpeter in 1934). These different lines are to do with acknowledging how innovative sources are heterogenic and intangible. Also, it is argued......Present paper discusses sources of innovation as heterogenic and at times intangible processes. Arguing for heterogeneity and intangibility as sources of innovation originates from a theoretical reading in STS and ANT studies (e.g. Callon 1986, Latour 1996, Mol 2002, Pols 2005) and from field work...... in the area of mental health (Dupret Søndergaard 2009, 2010). The concept of sensitive innovation is developed to capture and conceptualise exactly those heterogenic and intangible processes. Sensitive innovation is therefore primarily a way to understand innovative sources that can be...

  9. Detection of Legume Protease Inhibitors by the Gel-X-ray Film Contact Print Technique

    Science.gov (United States)

    Mulimani, Veerappa H.; Sudheendra, Kulkarni; Giri, Ashok P.

    2002-01-01

    Redgram (Cajanus cajan L.) extracts have been analyzed for the protease inhibitors using a new, sensitive, simple, and rapid method for detection of electrophoretically separated protease inhibitors. The detection involves equilibrating the gel successively in the protease assay buffer and protease solution, rinsing the gel in assay buffer, and…

  10. Inhibitors of lysosomal cysteine proteases

    Directory of Open Access Journals (Sweden)

    Lyanna O. L.

    2011-04-01

    Full Text Available The review is devoted to the inhibitors of cysteine proteinases which are believed to be very important in many biochemical processes of living organisms. They participate in the development and progression of numerous diseases that involve abnormal protein turnover. One of the main regulators of these proteinases is their specific inhibitors: cystatins. The aim of this review was to present current knowledge about endogenous inhibitors of lysosomal cysteine proteases and their synthetic analogs.

  11. Molecular similarity of MDR inhibitors

    OpenAIRE

    Simon Gibbons; Mire Zloh

    2004-01-01

    Abstract: The molecular similarity of multidrug resistance (MDR) inhibitors was evaluated using the point centred atom charge approach in an attempt to find some common features of structurally unrelated inhibitors. A series of inhibitors of bacterial MDR were studied and there is a high similarity between these in terms of their shape, presence and orientation of aromatic ring moieties. A comparison of the lipophilic properties of these molecules has also been conducted suggesting that this ...

  12. Therapeutic potential of an orally effective small molecule inhibitor of plasminogen activator inhibitor for asthma.

    Science.gov (United States)

    Liu, Rui-Ming; Eldridge, Stephanie; Watanabe, Nobuo; Deshane, Jessy; Kuo, Hui-Chien; Jiang, Chunsun; Wang, Yong; Liu, Gang; Schwiebert, Lisa; Miyata, Toshio; Thannickal, Victor J

    2016-02-15

    Asthma is one of the most common respiratory diseases. Although progress has been made in our understanding of airway pathology and many drugs are available to relieve asthma symptoms, there is no cure for chronic asthma. Plasminogen activator inhibitor 1 (PAI-1), a primary inhibitor of tissue-type and urokinase-type plasminogen activators, has pleiotropic functions besides suppression of fibrinolysis. In this study, we show that administration of TM5275, an orally effective small-molecule PAI-1 inhibitor, 25 days after ovalbumin (OVA) sensitization-challenge, significantly ameliorated airway hyperresponsiveness in an OVA-induced chronic asthma model. Furthermore, we show that TM5275 administration significantly attenuated OVA-induced infiltration of inflammatory cells (neutrophils, eosinophils, and monocytes), the increase in the levels of OVA-specific IgE and Th2 cytokines (IL-4 and IL-5), the production of mucin in the airways, and airway subepithelial fibrosis. Together, the results suggest that the PAI-1 inhibitor TM5275 may have therapeutic potential for asthma through suppressing eosinophilic allergic response and ameliorating airway remodeling. PMID:26702150

  13. ACE INHIBITORS: A COMPREHENSIVE REVIEW

    Directory of Open Access Journals (Sweden)

    Pradeep Kumar Arora* and Ashish Chauhan

    2013-02-01

    Full Text Available Hypertension is a chronic increase in blood pressure, characterized as primary and secondary hypertension. The disorder is associated with various risk factors like obesity, diabetes, age, lack of exercise etc. Hypertension is being treated since ancient times by Ayurvedic, Chinese and Unani medicine. Now various allopathic drugs are available which include diuretics, calcium channel blockers, α-blockers, β-blockers, vasodilators, central sympatholytics and ACE-inhibitors. Non-pharmacological treatments include weight reduction, dietary sodium reduction, increased potassium intake and reduction in alcohol consumption. ACE-inhibitors are widely used in the treatment of hypertension by inhibiting the angiotensin converting enzyme responsible for the conversion of angiotensin I to angiotensin II (responsible for vasoconstriction. Various structure activity relationship studies led to the synthesis of ACE-inhibitors, some are under clinical development. This comprehensive review gives various guidelines on classification of hypertension, hypertension therapy including ancient, pharmacological, non-pharmacological therapies, pharmacoeconomics, historical perspectives of ACE, renin, renin angiotensin system (circulating vs local RAS, mechanism of ACE inhibitors, and development of ACE inhibitors. Review also emphasizes on the recent advancements on ACE inhibitors including drugs in clinical trials, computational studies on ACE-inhibitors, peptidomimetics, dual, natural, multi-functional ACE inhibitors, and conformational requirements for ACE-inhibitors.

  14. A syndrome of female pseudohermaphrodism, hypergonadotropic hypogonadism, and multicystic ovaries associated with missense mutations in the gene encoding aromatase (P450arom)

    Energy Technology Data Exchange (ETDEWEB)

    Conte, F.A.; Grumbach, M.M. [Univ. of California, San Francisco, CA (United States); Ito, Y.; Fisher, C.R.; Simpson, E.R. [Univ. of Texas Southwestern Medical Center, Dallas, TX (United States)

    1994-06-01

    The authors report the features of a new syndrome of aromatase deficiency due to molecular defects in the CYP19 (P450arom) gene in a 46,XX female. At birth, the patient presented with a nonadrenal form of female pseudohermaphrodism. At 17 months of age, laparotomy revealed normal female internal genital structures; the histological appearance of the ovaries was normal. FSH concentrations were markedly elevated at 9.4 ng/mL LER 869, and estrone and estradiol levels were undetectable (<37 pmol/L). By 14 yr of age, she had failed to exhibit breast development. The clitoris has enlarged to 4 x 2 cm, and pubic hair was Tanner stage IV. The plasma concentration of testosterone was elevated at 3294 pmol/L, as was androstenedione at 9951 pmol/L. Plasma estradiol levels were below 37 pmol/L. ACTH and dexamethasone tests indicated a nonadrenal source of testosterone and androstenedione. Plasma gonadotropin levels were in the castrate range. Pelvic sonography and magnetic resonance imaging showed multiple 4- to 6-cm ovarian cysts bilaterally. Despite increased circulating androgens and clitoral growth, the bone age was 10 yr at chronologic age 14 2/12 yr. Estrogen replacement therapy resulted in a growth spurt, breast development, menarche, suppression of gonadotropin levels, and resolution of the cysts. The clinical findings suggested the diagnosis of P450arom deficiency. Analyses of genomic DNA from ovarian fibroblasts demonstrated two single base changes in the coding region of the P450arom gene, one at 1303 basepairs (C-T), R435C, and the other at 1310 basepairs (G-A), C437Y, in exon 10. The molecular genetic studies indicate that the patient is a compound heterozygote for these mutations. Expression of these mutations showed that the R435C mutation had 1.1% the activity of the wild-type P450arom enzyme, whereas the C437Y mutation demonstrated no activity. 32 refs., 6 figs., 2 tabs.

  15. Between-female variation in house sparrow yolk testosterone concentration is negatively associated with CYP19A1 (aromatase) mRNA expression in ovarian follicles.

    Science.gov (United States)

    Egbert, Jeremy R; Jackson, Melissa F; Rodgers, Buel D; Schwabl, Hubert

    2013-03-01

    Maternally-derived yolk androgens influence the development and long-term phenotype of offspring in oviparous species. Between-female variation in the amounts of these yolk androgens has been associated with a number of social and environmental factors, suggesting that the variation is adaptive, but the mechanisms behind it are unknown. Using two different approaches, we tested the hypothesis that variation in yolk androgen levels across individuals is associated with variation in their capacity to synthesize androgens. First, we injected female house sparrows with exogenous gonadotropin-releasing hormone (GnRH) to maximally stimulate ovarian steroidogenesis. Second, we collected pre-ovulatory follicle tissue and quantified the mRNA expression of four key enzymes of the steroid synthesis pathway: steroidogenic acute regulatory protein (StAR), cytochrome P450-side chain cleavage enzyme (CYP11A1), 17β-hydroxysteroid dehydrogenase (HSD17B1), and aromatase (CYP19A1). Thirty minutes after GnRH injection, androgen concentrations in both the plasma and in the yolks of pre-ovulatory follicles were significantly elevated compared to controls. However, this measure of steroidogenic capacity did not explain variation in yolk testosterone levels, although physiological differences between house sparrows and more widely studied poultry models were revealed by this approach. Steroidogenic enzyme mRNA levels were detectable in all samples and were significantly lower in the most mature pre-ovulatory follicles. Of the four measured genes, CYP19A1 expression exhibited a significant negative relationship with yolk testosterone concentrations in laid eggs, revealing a key mechanism for between-female variation in yolk testosterone. Furthermore, this suggests that any factors which alter the expression of CYP19A1 within an individual female could have dramatic effects on offspring phenotype. PMID:23247271

  16. Diverse inhibitor chemotypes targeting Trypanosoma cruzi CYP51.

    Directory of Open Access Journals (Sweden)

    Shamila S Gunatilleke

    Full Text Available BACKGROUND: Chagas Disease, a WHO- and NIH-designated neglected tropical disease, is endemic in Latin America and an emerging infection in North America and Europe as a result of population moves. Although a major cause of morbidity and mortality due to heart failure, as well as inflicting a heavy economic burden in affected regions, Chagas Disease elicits scant notice from the pharmaceutical industry because of adverse economic incentives. The discovery and development of new routes to chemotherapy for Chagas Disease is a clear priority. METHODOLOGY/PRINCIPAL FINDINGS: The similarity between the membrane sterol requirements of pathogenic fungi and those of the parasitic protozoon Trypanosoma cruzi, the causative agent of Chagas human cardiopathy, has led to repurposing anti-fungal azole inhibitors of sterol 14α-demethylase (CYP51 for the treatment of Chagas Disease. To diversify the therapeutic pipeline of anti-Chagasic drug candidates we exploited an approach that included directly probing the T. cruzi CYP51 active site with a library of synthetic small molecules. Target-based high-throughput screening reduced the library of ∼104,000 small molecules to 185 hits with estimated nanomolar K(D values, while cross-validation against T. cruzi-infected skeletal myoblast cells yielded 57 active hits with EC(50 <10 µM. Two pools of hits partially overlapped. The top hit inhibited T. cruzi with EC(50 of 17 nM and was trypanocidal at 40 nM. CONCLUSIONS/SIGNIFICANCE: The hits are structurally diverse, demonstrating that CYP51 is a rather permissive enzyme target for small molecules. Cheminformatic analysis of the hits suggests that CYP51 pharmacology is similar to that of other cytochromes P450 therapeutic targets, including thromboxane synthase (CYP5, fatty acid ω-hydroxylases (CYP4, 17α-hydroxylase/17,20-lyase (CYP17 and aromatase (CYP19. Surprisingly, strong similarity is suggested to glutaminyl-peptide cyclotransferase, which is unrelated to CYP

  17. Characterization of a mantle cell lymphoma cell line resistant to the Chk1 inhibitor PF-00477736.

    Science.gov (United States)

    Restelli, Valentina; Chilà, Rosaria; Lupi, Monica; Rinaldi, Andrea; Kwee, Ivo; Bertoni, Francesco; Damia, Giovanna; Carrassa, Laura

    2015-11-10

    Mantle cell lymphoma (MCL) is an aggressive B-cell lymphoma characterized by the chromosomal translocation t(11;14) that leads to constitutive expression of cyclin D1, a master regulator of the G1-S phase. Chk1 inhibitors have been recently shown to be strongly effective as single agents in MCL. To investigate molecular mechanisms at the basis of Chk1 inhibitor activity, a MCL cell line resistant to the Chk1 inhibitor PF-00477736 (JEKO-1 R) was obtained and characterized. The JEKO-1 R cell line was cross resistant to another Chk1 inhibitor (AZD-7762) and to the Wee1 inhibitor MK-1775. It displayed a shorter doubling time than parental cell line, likely due to a faster S phase. Cyclin D1 expression levels were decreased in resistant cell line and its re-overexpression partially re-established PF-00477736 sensitivity. Gene expression profiling showed an enrichment in gene sets involved in pro-survival pathways in JEKO-1 R. Dasatinib treatment partly restored PF-00477736 sensitivity in resistant cells suggesting that the pharmacological interference of pro-survival pathways can overcome the resistance to Chk1 inhibitors. These data further corroborate the involvement of the t(11;14) in cellular sensitivity to Chk1 inhibitors, fostering the clinical testing of Chk1 inhibitors as single agents in MCL. PMID:26439697

  18. Selection criteria for corrosion inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Webb, L.; Boivin, J. [Cormetrics, Calgary, AB (Canada)

    2008-07-01

    The use of a corrosion inhibitor is the primary method to control internal corrosion of pipelines and to reduce costly failures. This presentation discussed the selection criteria for corrosion inhibitors. The selection process requires a detailed analysis of system chemistry; modeling flow regime; and laboratory testing protocols that challenge the inhibitor under conditions analogous to the field. The nature of corrosion inhibitors and inhibitor requirements were described. Physical factors were also presented. These included viscosity and pour point; stability; density; effect on elastomers and other materials; emulsion tendency; foaming tendency; gunking; polymerization/sludging; and reaction with gases and liquids. Other topics that were discussed included compatibility; solubility; partitioning; environmental effects; and selection requirements. Film tenacity was described in terms of corrosivity; water chemistry; and flow. The presentation concluded with a discussion of performance testing and wheel testing. figs.

  19. Enantioselective Synthesis of Protease Inhibitors and AntiHIV Agents

    Institute of Scientific and Technical Information of China (English)

    WANG Zhe

    2001-01-01

    @@ Part 1: A highly enantio-and diastereoselective Ireland-Claisen rearrangement of chiral C3(acyloxy)-vinyl silanes for the synthesis of anti-disubstituted succinic acid, an important intermediate for matrix metalloprotease inhibitors, has been developed (enantio-and anti/syn selectivities up to 95% and 38/1). The diastereoselectivity of this reaction was found to be sensitive to remote hydroxyl protecting groups, for example, with-OMOM group, the anti/syn ratio was 19/1, while with-OTBDMS, the ratio was 38/1. The resultant Ireland-Claisen rearrangement product was applied to the synthesis of macrocyclic MMP inhibitors, such as SL 422.

  20. Increase in in utero exposure to a migrant, 4,4'-butylidenebis(6-t-butyl-m-cresol), from nitrile-butadiene rubber gloves on brain aromatase activity in male rats.

    Science.gov (United States)

    Satoh, Kanako; Nonaka, Ryouichi; Nakae, Dai; Ogata, Akio

    2010-01-01

    4,4'-Butylidenebis(6-t-butyl-m-cresol) (BBBC) can be eluted from disposable gloves made of nitrile-butadiene rubber and possibly also detected in food. It has been reported that BBBC is an androgen and estrogen antagonist in vitro. Previously, BBBC (1.0 mg/kg body weight (bw)/d) was subcutaneously administered to pregnant rats from gestation days 11 through 18, and the effects on male offspring (postnatal day 102) were examined. Altered levels and turnover of the monoamines dopamine, serotonin, and noradrenalin as well as their metabolites were detected. This report measured the level of serum testosterone following prenatal exposure to BBBC (0.1, 1.0, 10 mg/kg bw/d) in male rats, and measured aromatase activity of the hypothalamus-preoptic area with a close connection to the sexual differentiation and sexual behavior of BBBC-treated rat brains. The serum testosterone level rose depending on exposure, and aromatase activity of the basomedial nucleus of amygdale region was increased in the BBBC-treated group compared with the control. These results suggested that prenatal exposure to BBBC affects the central nervous system of male rat offspring, and BBBC may be an endocrine disrupting-chemical during the fetal period, and might influence the functional development of the brain.

  1. Inhibiting the inhibitors: retro-inverso Smac peptides.

    Science.gov (United States)

    Hossbach, Julia; Michalsky, Elke; Henklein, Peter; Jaeger, Marten; Daniel, Peter T; Preissner, Robert

    2009-12-01

    Resistance against apoptosis-inducing anti-cancer drugs remains a severe problem in therapy. One reason is the overexpression of inhibitors of apoptosis proteins (IAPs), a group of proteins responsible for the prevention of apoptosis induction by inactivation of initiator caspases. The natural inhibitor of the IAPs is the protein Smac, which impedes the binding to the caspases. Although Smac is a potent inhibitor, Smac peptides are not very stable in vivo and thus not applicable in therapy. Bioinformatical methods were applied to design Smac-derived peptides to break the therapy resistance in IAP high-expressing tumor cells. The exchange of amino acids in the Smac peptides AVPI and AVPF against unnatural amino acids leads to an improvement of the apoptosis sensitivity. The variety of Smac peptides was filtered by computational docking. Moreover, Smac-derived peptides with sufficient binding to the IAPs were tested in IAP-expressing Hodgkin Lymphoma cell lines.

  2. Biosensors for the determination of environmental inhibitors of enzymes

    International Nuclear Information System (INIS)

    Characteristic features of functioning and practical application of enzyme-based biosensors for the determination of environmental pollutants as enzyme inhibitors are considered with special emphasis on the influence of the methods used for the measurement of the rates of enzymic reactions, of enzyme immobilisation procedure and of the composition of the reaction medium on the analytical characteristics of inhibitor assays. The published data on the development of biosensors for detecting pesticides and heavy metals are surveyed. Special attention is given to the use of cholinesterase-based biosensors in environmental and analytical monitoring. The approaches to the estimation of kinetic parameters of inhibition are reviewed and the factors determining the selectivity and sensitivity of inhibitor assays in environmental objects are analysed. The bibliography includes 195 references.

  3. Synthesis of Lysine Methyltransferase Inhibitors

    Directory of Open Access Journals (Sweden)

    Tao eYe

    2015-07-01

    Full Text Available Lysine methyltransferase which catalyze methylation of histone and nonhistone proteins, play a crucial role in diverse biological processes and has emerged as a promising target for the development of various human diseases, including cancer, inflammation, and psychiatric disorders. However, inhibiting Lysine methyltransferases selectively has presented many challenges to medicinal chemists. During the past decade, lysine methyltransferase inhibitors covering many different structural classes have been designed and developed. In this review, we describe the development of selective, small-molecule inhibitors of lysine methyltransferases with an emphasis on their discovery and chemical synthesis. We highlight the current state of lysine methyltransferase inhibitors and discuss future directions and opportunities for lysine methyltransferase inhibitor discovery.

  4. Simplified assays of lipolysis enzymes for drug discovery and specificity assessment of known inhibitors.

    Science.gov (United States)

    Iglesias, Jose; Lamontagne, Julien; Erb, Heidi; Gezzar, Sari; Zhao, Shangang; Joly, Erik; Truong, Vouy Linh; Skorey, Kathryn; Crane, Sheldon; Madiraju, S R Murthy; Prentki, Marc

    2016-01-01

    Lipids are used as cellular building blocks and condensed energy stores and also act as signaling molecules. The glycerolipid/ fatty acid cycle, encompassing lipolysis and lipogenesis, generates many lipid signals. Reliable procedures are not available for measuring activities of several lipolytic enzymes for the purposes of drug screening, and this resulted in questionable selectivity of various known lipase inhibitors. We now describe simple assays for lipolytic enzymes, including adipose triglyceride lipase (ATGL), hormone sensitive lipase (HSL), sn-1-diacylglycerol lipase (DAGL), monoacylglycerol lipase, α/β-hydrolase domain 6, and carboxylesterase 1 (CES1) using recombinant human and mouse enzymes either in cell extracts or using purified enzymes. We observed that many of the reported inhibitors lack specificity. Thus, Cay10499 (HSL inhibitor) and RHC20867 (DAGL inhibitor) also inhibit other lipases. Marked differences in the inhibitor sensitivities of human ATGL and HSL compared with the corresponding mouse enzymes was noticed. Thus, ATGListatin inhibited mouse ATGL but not human ATGL, and the HSL inhibitors WWL11 and Compound 13f were effective against mouse enzyme but much less potent against human enzyme. Many of these lipase inhibitors also inhibited human CES1. Results describe reliable assays for measuring lipase activities that are amenable for drug screening and also caution about the specificity of the many earlier described lipase inhibitors.

  5. [Pharmacology of bone resorption inhibitor].

    Science.gov (United States)

    Menuki, Kunitaka; Sakai, Akinori

    2015-10-01

    Currently, bone resorption inhibitor is mainly used for osteoporosis. A number of these agents have been developed. These pharmacological action are various. Bisphosphonate inhibit functions of the osteoclasts by inducing apoptosis. On the one hand, RANK-ligand inhibitor and selective estrogen receptor modulator inhibit formation of osteoclasts. It is important to understand these pharmacological action for the selection of the appropriate medicine. PMID:26529923

  6. Antineoplastic effects of mammalian target of rapamycine inhibitors.

    Science.gov (United States)

    Salvadori, Maurizio

    2012-10-24

    Cancer after transplantation is the third cause of death and one of the more relevant comorbidities. Aim of this review is to verify the role of different pathogenetic mechanisms in cancer development in transplant patients and in general population as well. In particular has been outlined the different role exerted by two different families of drug as calcineurin inhibitor and mammalian target of rapamycin (mTOR) inhibitor. The role of mTOR pathways in cell homeostasis is complex but enough clear. As a consequence the mTOR pathway deregulation is involved in the genesis of several cancers. Hence the relevant role of mTOR inhibitors. The authors review the complex mechanism of action of mTOR inhibitors, not only for what concerns the immune system but also other cells as endothelial, smooth muscle and epithelial cells. The mechanism of action is still now not completely defined and understood. It implies the inhibition of mTOR pathway at different levels, but mainly at level of the phosphorylation of several intracellular kinases that contribute to activate mTOR complex. Many prospective and retrospective studies in transplant patients document the antineoplastic role of mTOR inhibition. More recently mTOR inhibitors proven to be effective in the treatment of some cancers also in general population. Kidney cancers, neuroendocrine tumors and liver cancers seem to be the most sensitive to these drugs. Best results are obtained with a combination treatment, targeting the mTOR pathway at different levels. PMID:24175199

  7. Undecaprenyl diphosphate synthase inhibitors: antibacterial drug leads.

    Science.gov (United States)

    Sinko, William; Wang, Yang; Zhu, Wei; Zhang, Yonghui; Feixas, Ferran; Cox, Courtney L; Mitchell, Douglas A; Oldfield, Eric; McCammon, J Andrew

    2014-07-10

    There is a significant need for new antibiotics due to the rise in drug resistance. Drugs such as methicillin and vancomycin target bacterial cell wall biosynthesis, but methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococci (VRE) have now arisen and are of major concern. Inhibitors acting on new targets in cell wall biosynthesis are thus of particular interest since they might also restore sensitivity to existing drugs, and the cis-prenyl transferase undecaprenyl diphosphate synthase (UPPS), essential for lipid I, lipid II, and thus, peptidoglycan biosynthesis, is one such target. We used 12 UPPS crystal structures to validate virtual screening models and then assayed 100 virtual hits (from 450,000 compounds) against UPPS from S. aureus and Escherichia coli. The most promising inhibitors (IC50 ∼2 μM, Ki ∼300 nM) had activity against MRSA, Listeria monocytogenes, Bacillus anthracis, and a vancomycin-resistant Enterococcus sp. with MIC or IC50 values in the 0.25-4 μg/mL range. Moreover, one compound (1), a rhodanine with close structural similarity to the commercial diabetes drug epalrestat, exhibited good activity as well as a fractional inhibitory concentration index (FICI) of 0.1 with methicillin against the community-acquired MRSA USA300 strain, indicating strong synergism. PMID:24827744

  8. Ximelagatran: direct thrombin inhibitor

    Directory of Open Access Journals (Sweden)

    Shir-Jing Ho

    2006-03-01

    -major orthopedic surgery. It has also been shown to be more effective than aspirin alone for prevention of recurrent major cardiovascular events in patients with recent myocardial infarction.Keywords: Ximelagatran, direct thrombin inhibitor, oral anticoagulants, thromboprophylaxis

  9. Transcriptome analysis of Zymomonas mobilis ZM4 reveals mechanisms of tolerance and detoxification of phenolic aldehyde inhibitors from lignocellulose pretreatment

    OpenAIRE

    Yi, Xia; Gu, Hanqi; Gao, Qiuqiang; Liu, Z. Lewis; Bao, Jie

    2015-01-01

    Background Phenolic aldehydes generated from lignocellulose pretreatment exhibited severe toxic inhibitions on microbial growth and fermentation. Numerous tolerance studies against furfural, 5-hydroxymethyl-2-furaldehyde (HMF), acetate, and ethanol were reported, but studies on inhibition of phenolic aldehyde inhibitors are rare. For ethanologenic strains, Zymomonas mobilis ZM4 is high in ethanol productivity and genetic manipulation feasibility, but sensitive to phenolic aldehyde inhibitors....

  10. Anti-tumor Action and Clinical Application of Proteasome Inhibitor

    Institute of Scientific and Technical Information of China (English)

    ZHOU Yong-ming; YU Mei-xia; LONG Hui; HUANG Shi-ang

    2008-01-01

    Ubiquitin-proteasome pathway mediates the degradation of cell protein,and cell cycle,gene translation and expression,antigen presentation and inflammatory development.Proteasome inhibitor Call inhibit growth and proliferation of tumor cell,induce apoptosis and reverse multipledrug resistance of tumor cell,increase the sensitivity of other chemomerapeutic drugs and radiotherapy,and is a novel class of potent anti-tumor agents.

  11. Sodium-Glucose Cotransporter 2 Inhibitors: Possible Anti-Atherosclerotic Effects Beyond Glucose Lowering.

    Science.gov (United States)

    Yanai, Hidekatsu; Katsuyama, Hisayuki; Hamasaki, Hidetaka; Adachi, Hiroki; Moriyama, Sumie; Yoshikawa, Reo; Sako, Akahito

    2016-01-01

    The new drug for type 2 diabetes, the sodium-glucose cotransporter 2 (SGLT-2) inhibitor, is reversible inhibitor of SGLT-2, leading to reduction of renal glucose reabsorption and decrease of plasma glucose, in an insulin-independent manner. In addition to glucose control, the management of coronary risk factors is very important for patients with diabetes. Here we reviewed published articles about the possible anti-atherosclerotic effects beyond glucose lowering of the SGLT-2 inhibitors. We searched by using Pubmed, and found 770 published articles about SGLT-2 inhibitors. Among 10 kinds of SGLT-2 inhibitors, the number of published articles about dapagliflozin was the greatest among SGLT-2 inhibitors. Since SGLT-2 inhibitors have similar chemical structures, we concentrated on the published articles about dapagliflozin. SGLT-2 inhibitors are proved to be significantly associated with weight loss and reduction of blood pressure by a relatively large number of studies. The studies investigating effects of dapagliflozin on visceral fat, insulin sensitivity, serum lipids, inflammation and adipocytokines are very limited. An influence of increase in glucagon secretion by SGLT-2 inhibitors on metabolic risk factors remains unknown. PMID:26668677

  12. Fragment-Based Screening for Enzyme Inhibitors Using Calorimetry.

    Science.gov (United States)

    Recht, Michael I; Nienaber, Vicki; Torres, Francisco E

    2016-01-01

    Isothermal titration calorimetry (ITC) provides a sensitive and accurate means by which to study the thermodynamics of binding reactions. In addition, it enables label-free measurement of enzymatic reactions. The advent of extremely sensitive microcalorimeters have made it increasingly valuable as a tool for hit validation and characterization, but its use in primary screening is hampered by requiring large quantities of reagents and long measurement times. Nanocalorimeters can overcome these limitations of conventional ITC, particularly for screening libraries of 500-1000 compounds such as those encountered in fragment-based lead discovery. This chapter describes how nanocalorimetry and conventional microcalorimetry can be used to screen compound libraries for enzyme inhibitors.

  13. PARP1 inhibitors attenuate AKT phosphorylation via the upregulation of PHLPP1

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shuai [State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025 (China); Division of Hematology and Oncology, Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL 35205 (United States); Wang, Huibo; Davis, Ben C. [Division of Hematology and Oncology, Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL 35205 (United States); Liang, Jiyong [Department of Systems Biology, University of Texas MD Anderson Cancer Center, Houston, TX 77054 (United States); Cui, Rutao [Department of Dermatology, Boston University School of Medicine, Boston, MA 02118 (United States); Chen, Sai-Juan, E-mail: sjchen@stn.sh.cn [State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025 (China); Xu, Zhi-Xiang, E-mail: zhi-xiang.xu@ccc.uab.edu [Division of Hematology and Oncology, Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL 35205 (United States)

    2011-08-26

    Highlights: {yields} PARP1 inhibitors cause a cytotoxic effect independent of DNA repair impairment. {yields} PARP1 inhibitors attenuated AKT-FOXO3A signaling by activating PHLPP1. {yields} PHLPP1 regulates the sensitivity of cancer cells to PARP1 inhibitors. -- Abstract: Poly(ADP-ribose) polymerase-1 (PARP1) inhibitors are emerging as an important class of drugs for treating BRCA-deficient cancers. Recent discoveries have shown that PARP1 inhibitors may treat other cancer patients in addition to the relatively small proportion of patients carrying BRCA mutations. However, the additional targets by which PARP1 inhibitor-mediated tumor suppression remain poorly understood. In this study, we show that two PARP1 inhibitors, PJ-34 and 3-AB, attenuate AKT phosphorylation at serine 473 (S473) independent of DNA repair impairment. These inhibitors decrease the AKT-associated phosphorylation of FOXO3A, enhance the nuclear retention of FOXO3A, and activate its transcriptional activity. We further demonstrate that treatment with PJ-34 or 3-AB dramatically increases the level of PHLPP1. Overexpression of PHLPP1 enhances the PARP1 inhibitor-induced downregulation of AKT phosphorylation and increases tumor cell death. In contrast, knockdown of PHLPP1 abrogates the PARP1 inhibitor-mediated AKT inhibition and desensitizes cells to its treatment. Therefore, our findings not only show the robust role of PARP1 inhibitors in AKT inhibition but also develop a novel strategy to increase the effectiveness of cancer treatment via PARP1 inhibitor-induced PHLPP1 upregulation.

  14. Microbial inhibitors of cysteine proteases.

    Science.gov (United States)

    Kędzior, Mateusz; Seredyński, Rafał; Gutowicz, Jan

    2016-08-01

    Cysteine proteases are one of the major classes of proteolytic enzymes involved in a number of physiological and pathological processes in plants, animals and microorganisms. When their synthesis, activity and localization in mammalian cells are altered, they may contribute to the development of many diseases, including rheumatoid arthritis, osteoporosis and cancer. Therefore, cysteine proteases have become promising drug targets for the medical treatment of these disorders. Inhibitors of cysteine proteases are also produced by almost every group of living organisms, being responsible for the control of intracellular proteolytic activity. Microorganisms synthesize cysteine protease inhibitors not only to regulate the activity of endogenous, often virulent enzymes, but also to hinder the host's proteolytic defense system and evade its immune responses against infections. Present work describes known to date microbial inhibitors of cysteine proteases in terms of their structure, enzyme binding mechanism, specificity and pathophysiological roles. The overview of both proteinaceous and small-molecule inhibitors produced by all groups of microorganisms (bacteria, archaea, fungi, protists) and viruses is provided. Subsequently, possible applications of microbial inhibitors in science, medicine and biotechnology are also highlighted. PMID:27048482

  15. Inhibitor degradation and lipid accumulation potentials of oleaginous yeast Trichosporon cutaneum using lignocellulose feedstock.

    Science.gov (United States)

    Wang, Juan; Gao, Qiuqiang; Zhang, Huizhan; Bao, Jie

    2016-10-01

    Oleaginous yeast Trichosporon cutaneum is robust to high levels of lignocellulose derived inhibitor compounds with considerable lipid accumulation capacity. The potential of lipid accumulation of T. cutaneum ACCC 20271 was investigated using corn stover hydrolysates with varying sugar and inhibitor concentrations. Biodiesel was synthesized using the extracted lipid and the product satisfied the ASTM standards. Among the typical inhibitors, T. cutaneum ACCC 20271 is relatively sensitive to furfural and 4-hydroxybenzaldehyde, but strongly tolerant to high titers of formic acid, acetic acid, levulinic acid, HMF, vanillin, and syringaldehyde. It is capable of complete degradation of formic acid, acetic acid, vanillin and 4-hydroxybenzaldehyde. Finally, the inhibitor degradation pathways of T. cutaneum ACCC 20271 were constructed based on the newly sequenced whole genome information and the experimental results. The study provided the first insight to the inhibitor degradation of T. cutaneum and demonstrated the potentials of lipid production from lignocellulose. PMID:27441826

  16. Diverse inhibitors of aflatoxin biosynthesis.

    Science.gov (United States)

    Holmes, Robert A; Boston, Rebecca S; Payne, Gary A

    2008-03-01

    Pre-harvest and post-harvest contamination of maize, peanuts, cotton, and tree nuts by members of the genus Aspergillus and subsequent contamination with the mycotoxin aflatoxin pose a widespread food safety problem for which effective and inexpensive control strategies are lacking. Since the discovery of aflatoxin as a potently carcinogenic food contaminant, extensive research has been focused on identifying compounds that inhibit its biosynthesis. Numerous diverse compounds and extracts containing activity inhibitory to aflatoxin biosynthesis have been reported. Only recently, however, have tools been available to investigate the molecular mechanisms by which these inhibitors affect aflatoxin biosynthesis. Many inhibitors are plant-derived and a few may be amenable to pathway engineering for tissue-specific expression in susceptible host plants as a defense against aflatoxin contamination. Other compounds show promise as protectants during crop storage. Finally, inhibitors with different modes of action could be used in comparative transcriptional and metabolomic profiling experiments to identify regulatory networks controlling aflatoxin biosynthesis.

  17. Corrosion inhibitors from expired drugs.

    Science.gov (United States)

    Vaszilcsin, Nicolae; Ordodi, Valentin; Borza, Alexandra

    2012-07-15

    This paper presents a method of expired or unused drugs valorization as corrosion inhibitors for metals in various media. Cyclic voltammograms were drawn on platinum in order to assess the stability of pharmaceutically active substances from drugs at the metal-corrosive environment interface. Tafel slope method was used to determine corrosion rates of steel in the absence and presence of inhibitors. Expired Carbamazepine and Paracetamol tablets were used to obtain corrosion inhibitors. For the former, the corrosion inhibition of carbon steel in 0.1 mol L(-1) sulfuric acid solution was about 90%, whereas for the latter, the corrosion inhibition efficiency of the same material in the 0.25 mol L(-1) acetic acid-0.25 mol L(-1) sodium acetate buffer solution was about 85%.

  18. Chemistry of the interaction between azole type corrosion inhibitor molecules and metal surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Kovacevic, Natasa [Department of Physical and Organic Chemistry, Jozef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia); Kokalj, Anton, E-mail: tone.kokalj@ijs.si [Department of Physical and Organic Chemistry, Jozef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia)

    2012-11-15

    By means of density functional theory calculations, it has been shown how typical organic corrosion inhibitors-molecules that have the ability to remarkably slow down the corrosion of metals and alloys-interact with bare surfaces of various types of metals. As representative model systems, benzimidazole and benzotriazole inhibitors on iron, copper, and aluminum surfaces are considered. It is found that bonding depends sensitively on the type of metal. On transition metals with open d-band the inhibitor molecules can chemisorb strongly either parallel to the surface with a pronounced {pi}-d hybridization or perpendicularly with unsaturated N atom(s) through {sigma}-molecular orbitals, whereas on transition metals with fully occupied d-band and on sp-metals the molecules weakly chemisorb only with the latter mode. In addition to neutral inhibitor molecules also inhibitors in deprotonated (anionic) and protonated (cationic) forms are considered, because many corrosion inhibitors possess acidic hydrogens as well as basic heteroatoms. It is shown that the chemisorptive bonding is far the strongest for deprotonated inhibitors and, moreover, that even protonated inhibitors may chemisorb, although such bonding is characteristic of more reactive metals. However adsorbed protonated inhibitors are likely to deprotonate on all considered metals, whereas further deprotonation from neutral to deprotonated form is more likely on more reactive metals. Highlights: Black-Right-Pointing-Pointer Bonding of azole corrosion inhibitors onto metal surfaces characterized by DFT calculations. Black-Right-Pointing-Pointer Adsorption bonding depends sensitively on the type of metal. Black-Right-Pointing-Pointer Azoles bond with either {pi}-system or {sigma}-orbitals to transition metals with open d-band. Black-Right-Pointing-Pointer Azoles bond with {sigma}-orbitals to transition metals with fully occupied d-band and to sp-metals. Black-Right-Pointing-Pointer Among various molecular forms

  19. Poly (ADP-ribose) polymerase inhibitor:an evolving paradigm in the treatment of prostate cancer

    Institute of Scientific and Technical Information of China (English)

    Jingsong Zhang

    2014-01-01

    Recent phase I studies have reported single-agent activities of poly (ADP-ribose) polymerase (PARP) inhibitor in sporadic and in BRCA-mutant prostate cancers. Two of the most common genetic alterations in prostate cancer, ETS gene rearrangement and loss of PTEN, have been linked to increased sensitivity to PARP inhibitor in preclinical models. Emerging evidence also suggests that PARP1 plays an important role in mediating the transcriptional activities of androgen receptor (AR) and ETS gene rearrangement. In this article, the preclinical work and early-phase clinical trials in developing PARP inhibitor-based therapy as a new treatment paradigm for metastatic prostate cancer are reviewed.

  20. Poly (ADP-ribose polymerase inhibitor: an evolving paradigm in the treatment of prostate cancer

    Directory of Open Access Journals (Sweden)

    Jingsong Zhang

    2014-06-01

    Full Text Available Recent phase I studies have reported single-agent activities of poly (ADP-ribose polymerase (PARP inhibitor in sporadic and in BRCA-mutant prostate cancers. Two of the most common genetic alterations in prostate cancer, ETS gene rearrangement and loss of PTEN, have been linked to increased sensitivity to PARP inhibitor in preclinical models. Emerging evidence also suggests that PARP1 plays an important role in mediating the transcriptional activities of androgen receptor (AR and ETS gene rearrangement. In this article, the preclinical work and early-phase clinical trials in developing PARP inhibitor-based therapy as a new treatment paradigm for metastatic prostate cancer are reviewed.

  1. Adaptation, Compensation, and Recovery: Unraveling the Mechanisms through Genomics

    Science.gov (United States)

    A variety of chemicals in the environment have the potential to inhibit aromatase, an enzyme critical to estrogen synthesis. We examined the responses of female fathead minnows (Pimephales promelas) to a model aromatase inhibitor, fadrozole, using transcriptional network inferen...

  2. Reduced Airway Hyperresponsiveness by Phosphodiesterase 3 and 4 Inhibitors in Guinea-Pigs

    Directory of Open Access Journals (Sweden)

    Nöella Germain

    1999-01-01

    Full Text Available The aim of the present study was to compare the effects of selective phosphodiesterase (PDE 3, 4 and 5 inhibitors on antigen-induced airway hyperresponsiveness in sensitized guinea-pigs. When the sensitized guinea-pigs were orally pre-treated with the selective PDE4 inhibitor, Ro 20-1724 (30 mg/kg, and studied 48 h after OA, a significant reduction (p<0.01 of the leftward shift of the dose-response curve to ACh was noted, whereas it was ineffective at the lower dose (10 mg/kg. Administration of the selective PDE3 inhibitor, milrinone (30 mg/kg also elicited a significant reduction (p<0.01 of the airway hyperresponsiveness, whereas the PDE5 inhibitor zaprinast (30 mg/kg was ineffective. These results show that both PDE3 and PDE4 inhibitors are able to inhibit the antigen-induced airway hyperresponsiveness in sensitized guinea-pigs and support the potential utility of selective PDE inhibitors in the treatment of asthma.

  3. Cadmium absorption inhibitors for soil

    Energy Technology Data Exchange (ETDEWEB)

    Kitamura, S.

    1974-05-25

    Cadmium absorption by soil is one cause of soil pollution. Cadmium adsorption inhibitors were prepared by mixing alginic acid which contained brown algae (Ascophyllum nodosum) and an inorganic material, shell fossils. This mixture was highly effective in preventing cadmium absorption by the soil.

  4. Renal targeting of kinase inhibitors

    NARCIS (Netherlands)

    Dolman, M. E. M.; Fretz, M. M.; Segers, Gj. W.; Lacombe, M.; Prakash, J.; Storm, G.; Hennink, W. E.; Kok, R. J.

    2008-01-01

    Activation of proximal tubular cells by fibrotic and inflammatory mediators is an important hallmark of chronic kidney disease. We have developed a novel strategy to intervene in renal fibrosis, by means of locally delivered kinase inhibitors. Such compounds will display enhanced activity within tub

  5. Proton pump inhibitors and gastroenteritis

    NARCIS (Netherlands)

    R.J. Hassing (Robert); A. Verbon (Annelies); H. de Visser (Herman); A. Hofman (Albert); B.H.Ch. Stricker (Bruno)

    2016-01-01

    textabstractAn association between proton pump inhibitor (PPI) therapy and bacterial gastroenteritis has been suggested as well as contradicted. The aim of this study was to examine the association between the use of PPIs and occurrence of bacterial gastroenteritis in the prospective Rotterdam Study

  6. Biocatalysts with enhanced inhibitor tolerance

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Shihui; Linger, Jeffrey; Franden, Mary Ann; Pienkos, Philip T.; Zhang, Min

    2015-12-08

    Disclosed herein are biocatalysts for the production of biofuels, including microorganisms that contain genetic modifications conferring tolerance to growth and fermentation inhibitors found in many cellulosic feedstocks. Methods of converting cellulose-containing materials to fuels and chemicals, as well as methods of fermenting sugars to fuels and chemicals, using these biocatalysts are also disclosed.

  7. Resistance to mTOR kinase inhibitors in lymphoma cells lacking 4EBP1.

    Directory of Open Access Journals (Sweden)

    Sharmila Mallya

    Full Text Available Inhibitors of the mechanistic target of rapamycin (mTOR hold promise for treatment of hematological malignancies. Analogs of the allosteric mTOR inhibitor rapamycin are approved for mantle cell lymphoma but have limited efficacy in other blood cancers. ATP-competitive "active-site" mTOR inhibitors produce more complete mTOR inhibition and are more effective than rapamycin in preclinical models of leukemia, lymphoma and multiple myeloma. In parallel to clinical trials of active-site mTOR inhibitors, it will be important to identify resistance mechanisms that might limit drug efficacy in certain patients. From a panel of diffuse large B-cell lymphoma cell lines, we found that the VAL cell line is particularly resistant to apoptosis in the presence of active-site mTOR inhibitors. Mechanistic investigation showed that VAL does not express eukaryotic initiation factor 4E-binding protein-1 (4EBP1, a key negative regulator of translation controlled by mTOR. Although VAL cells express the related protein 4EBP2, mTOR inhibitor treatment fails to displace eukaryotic initiation factor 4G from the mRNA cap-binding complex. Knockdown of eukaryotic initiation factor 4E, or re-expression of 4EBP1, sensitizes cells to apoptosis when treated with active-site mTOR inhibitors. These findings provide a naturally occurring example of 4EBP deficiency driving lymphoma cell resistance to active-site mTOR inhibitors.

  8. Efficacy of c-Met inhibitor for advanced prostate cancer

    Directory of Open Access Journals (Sweden)

    Christensen James G

    2010-10-01

    Full Text Available Abstract Background Aberrant expression of HGF/SF and its receptor, c-Met, often correlates with advanced prostate cancer. Our previous study showed that expression of c-Met in prostate cancer cells was increased after attenuation of androgen receptor (AR signalling. This suggested that current androgen ablation therapy for prostate cancer activates c-Met expression and may contribute to development of more aggressive, castration resistant prostate cancer (CRPC. Therefore, we directly assessed the efficacy of c-Met inhibition during androgen ablation on the growth and progression of prostate cancer. Methods We tested two c-Met small molecule inhibitors, PHA-665752 and PF-2341066, for anti-proliferative activity by MTS assay and cell proliferation assay on human prostate cancer cell lines with different levels of androgen sensitivity. We also used renal subcapsular and castrated orthotopic xenograft mouse models to assess the effect of the inhibitors on prostate tumor formation and progression. Results We demonstrated a dose-dependent inhibitory effect of PHA-665752 and PF-2341066 on the proliferation of human prostate cancer cells and the phosphorylation of c-Met. The effect on cell proliferation was stronger in androgen insensitive cells. The c-Met inhibitor, PF-2341066, significantly reduced growth of prostate tumor cells in the renal subcapsular mouse model and the castrated orthotopic mouse model. The effect on cell proliferation was greater following castration. Conclusions The c-Met inhibitors demonstrated anti-proliferative efficacy when combined with androgen ablation therapy for advanced prostate cancer.

  9. Lipoxygenase inhibitor peptides and their use

    OpenAIRE

    Schurink, M.; Boeriu, C.G.; Berkel, van, A.M.; Wichers, H J

    2006-01-01

    The present invention is in the field of enzyme inhibition. In particular it relates to peptide inhibitors for lipoxygenases. The lipoxygenase peptide inhibitors of have the potential to be used as therapeutic drugs as well as food preservatives.

  10. Transcriptional changes associated with resistance to inhibitors of epidermal growth factor receptor revealed using metaanalysis

    International Nuclear Information System (INIS)

    EGFR is important in maintaining metabolic homeostasis in healthy cells, but in tumors it activates downstream signaling pathways, causing proliferation, angiogenesis, invasion and metastasis. Consequently, EGFR is targeted in cancers using reversible, irreversible or antibody inhibitors. Unfortunately, tumors develop inhibitor resistance by mutations or overexpressing EGFR, or its ligand, or activating secondary, EGFR-independent pathways. Here we present a global metaanalysis comparing transcriptional profiles from matched pairs of EGFR inhibitor-sensitive vs. -resistant cell lines, using 15 datasets comprising 274 microarrays. We also analyzed separately pairs of cell lines derived using reversible, irreversible or antibody inhibitors. The metaanalysis identifies commonalities in cell lines resistant to EGFR inhibitors: in sensitive cell lines, the ontological categories involving the ErbB receptors pathways, cell adhesion and lipid metabolism are overexpressed; however, resistance to EGFR inhibitors is associated with overexpression of genes for ErbB receptors-independent oncogenic pathways, regulation of cell motility, energy metabolism, immunity especially inflammatory cytokines biosynthesis, cell cycle and responses to exogenous and endogenous stimuli. Specifically in Gefitinib-resistant cell lines, the immunity-associated genes are overexpressed, whereas in Erlotinib-resistant ones so are the mitochondrial genes and processes. Unexpectedly, lines selected using EGFR-targeting antibodies overexpress different gene ontologies from ones selected using kinase inhibitors. Specifically, they have reduced expression of genes for proliferation, chemotaxis, immunity and angiogenesis. This metaanalysis suggests that ‘combination therapies’ can improve cancer treatment outcomes. Potentially, use of mitochondrial blockers with Erlotinib, immunity blockers with Gefitinib, tyrosine kinase inhibitors with antibody inhibitors, may have better chance of avoiding

  11. How Sensitively Timed Are Sensitive Periods?

    Science.gov (United States)

    Zener, Rita Schaefer

    2003-01-01

    Reviews Maria Montessori's view of sensitive periods and examines the kinds of help needed from adults: an open mind, specific help from a prepared learning environment, and challenges presented at the right time. Stresses the universality of sensitive periods and their connection to brain development. Focuses on the unconscious nature and…

  12. Enantioselective Synthesis of Protease Inhibitors and AntiHIV Agents

    Institute of Scientific and Technical Information of China (English)

    WANG; Zhe

    2001-01-01

    Part 1: A highly enantio-and diastereoselective Ireland-Claisen rearrangement of chiral C3(acyloxy)-vinyl silanes for the synthesis of anti-disubstituted succinic acid, an important intermediate for matrix metalloprotease inhibitors, has been developed (enantio-and anti/syn selectivities up to 95% and 38/1). The diastereoselectivity of this reaction was found to be sensitive to remote hydroxyl protecting groups, for example, with-OMOM group, the anti/syn ratio was 19/1, while with-OTBDMS, the ratio was 38/1. The resultant Ireland-Claisen rearrangement product was applied to the synthesis of macrocyclic MMP inhibitors, such as SL 422.……

  13. [Monitoring of Oral Thrombin Inhibitor].

    Science.gov (United States)

    Matsuno, Kazuhiko; Usami, Takayuki; Hatuse, Masanao; Shimizu, Chikara

    2014-10-01

    Dabigatran etexilate is a prodrug that is converted into its active metabolite, dabigatran, by hydrolysis. Dabigatran is a selective thrombin inhibitor that has been approved for the prevention of stroke in patients with non-valvular atrial fibrillation in Japan. Laboratory monitoring is not needed, but an assessment of its anticoagulant effect in certain clinical settings, such as emergency surgery, suspected overdose, or the occurrence of bleeding, is desirable. We overview the special coagulation assays, such as Hemoclot Thrombin Inhibitor (HTI), the thrombin generation assay (TGA), ecarin clotting time (ECT), ecarin chromogenic assay (ECA), prothrombinase-induced clotting time (PiCT), and activated clotting time (ACT). We also examined the relationship between dabigatran levels as determined by HTI, and the activated partial thromboplastin time (APTT) and prothrombin time (PT). APTT and PT demonstrated a positive correlation with the dabigatran levels. APTT, PT, and the combination of APTT and PT may estimate the dabigatran levels in plasma. PMID:27526541

  14. [Direct oral thrombin inhibitor, "dabigatran"].

    Science.gov (United States)

    Yasaka, Masahiro

    2013-01-01

    Dabigatran is an oral, direct, and competitive inhibitor of thrombin, which is administered to patients with non-valvular atrial fibrillation for prevention of stroke at a dose of 110 mg twice daily or 150 mg twice daily. Anticoagulation by dabigatran is "hybrid anticoagulation", consisting of action of both dabigatran and physiological coagulation inhibitors because warfarin inhibits production of protein C and protein S but dabigatran does not. Management of dabigatran is easier than that of warfarin because food restriction is unnecessary, drug interaction is small, and absorption time is short and serum concentration corresponds to the anticoagulatory effect in dabigatran treatment. The RE-LY trial confirmed effectiveness and safety of both doses of dabigatran for prevention of stroke and both doses of dabigatran had much lower risks of intracranial bleeding compared with warfarin. Compliance to guidance of dabigatran treatment is essential for avoidance of severe hemorrhagic complications. PMID:23631181

  15. Inhibitors of the interferon response enhance virus replication in vitro.

    Directory of Open Access Journals (Sweden)

    Claire E Stewart

    Full Text Available Virus replication efficiency is influenced by two conflicting factors, kinetics of the cellular interferon (IFN response and induction of an antiviral state versus speed of virus replication and virus-induced inhibition of the IFN response. Disablement of a virus's capacity to circumvent the IFN response enables both basic research and various practical applications. However, such IFN-sensitive viruses can be difficult to grow to high-titer in cells that produce and respond to IFN. The current default option for growing IFN-sensitive viruses is restricted to a limited selection of cell-lines (e.g. Vero cells that have lost their ability to produce IFN. This study demonstrates that supplementing tissue-culture medium with an IFN inhibitor provides a simple, effective and flexible approach to increase the growth of IFN-sensitive viruses in a cell-line of choice. We report that IFN inhibitors targeting components of the IFN response (TBK1, IKK2, JAK1 significantly increased virus replication. More specifically, the JAK1/2 inhibitor Ruxolitinib enhances the growth of viruses that are sensitive to IFN due to (i loss of function of the viral IFN antagonist (due to mutation or species-specific constraints or (ii mutations/host cell constraints that slow virus spread such that it can be controlled by the IFN response. This was demonstrated for a variety of viruses, including, viruses with disabled IFN antagonists that represent live-attenuated vaccine candidates (Respiratory Syncytial Virus (RSV, Influenza Virus, traditionally attenuated vaccine strains (Measles, Mumps and a slow-growing wild-type virus (RSV. In conclusion, supplementing tissue culture-medium with an IFN inhibitor to increase the growth of IFN-sensitive viruses in a cell-line of choice represents an approach, which is broadly applicable to research investigating the importance of the IFN response in controlling virus infections and has utility in a number of practical applications

  16. Kinase Inhibitors from Marine Sponges

    Directory of Open Access Journals (Sweden)

    Ana Zivanovic

    2011-10-01

    Full Text Available Protein kinases play a critical role in cell regulation and their deregulation is a contributing factor in an increasing list of diseases including cancer. Marine sponges have yielded over 70 novel compounds to date that exhibit significant inhibitory activity towards a range of protein kinases. These compounds, which belong to diverse structural classes, are reviewed herein, and ordered based upon the kinase that they inhibit. Relevant synthetic studies on the marine natural product kinase inhibitors have also been included.

  17. ACE INHIBITORS: A COMPREHENSIVE REVIEW

    OpenAIRE

    Pradeep Kumar Arora* and Ashish Chauhan

    2013-01-01

    Hypertension is a chronic increase in blood pressure, characterized as primary and secondary hypertension. The disorder is associated with various risk factors like obesity, diabetes, age, lack of exercise etc. Hypertension is being treated since ancient times by Ayurvedic, Chinese and Unani medicine. Now various allopathic drugs are available which include diuretics, calcium channel blockers, α-blockers, β-blockers, vasodilators, central sympatholytics and ACE-inhibitors. Non-pharmacological...

  18. Thrombin Inhibitors from Different Animals

    OpenAIRE

    Tanaka-Azevedo, A. M.; Morais-Zani, K.; Torquato, R. J. S.; A. S. Tanaka

    2010-01-01

    Venous and arterial thromboembolic diseases are still the most frequent causes of death and disability in high-income countries. Clinical anticoagulants are inhibitors of enzymes involved in the coagulation pathway, such as thrombin and factor Xa. Thrombin is a key enzyme of blood coagulation system, activating the platelets, converting the fibrinogen to the fibrin net, and amplifying its self-generation by the activation of factors V, VIII, and XI. Thrombin has long been a target for the dev...

  19. Conformation-specific inhibitors of Raf kinases.

    Science.gov (United States)

    Wang, Xiaolun; Schleicher, Kristin

    2013-01-01

    Since the discovery linking B-Raf mutations to human tumors in 2002, significant advances in the development of Raf inhibitors have been made, leading to the recent approval of two Raf inhibitor drugs. This chapter includes a brief introduction to B-Raf as a validated target and focuses on the three different binding modes observed with Raf small-molecule inhibitors. These various binding modes lock the Raf kinase in different conformations that impact the toxicity profiles of the inhibitors. Possible solutions to mitigate the side effects caused by inhibitor-induced dimerization are also discussed.

  20. A cyclic peptidic serine protease inhibitor

    DEFF Research Database (Denmark)

    Zhao, Baoyu; Xu, Peng; Jiang, Longguang;

    2014-01-01

    Peptides are attracting increasing interest as protease inhibitors. Here, we demonstrate a new inhibitory mechanism and a new type of exosite interactions for a phage-displayed peptide library-derived competitive inhibitor, mupain-1 (CPAYSRYLDC), of the serine protease murine urokinase...... pocket, its carbonyl group aligning improperly relative to Ser195 and the oxyanion hole, explaining why the peptide is an inhibitor rather than a substrate. Substitution of the P1 Arg with novel unnatural Arg analogues with aliphatic or aromatic ring structures led to an increased affinity, depending...... of this peptidic inhibitor, a concept different from conventional attempts at improving inhibitor affinity by reducing the entropic burden....

  1. Carbonic anhydrase inhibitors drug design.

    Science.gov (United States)

    McKenna, Robert; Supuran, Claudiu T

    2014-01-01

    Inhibition of the metalloenzyme carbonic anhydrase (CA, EC 4.2.1.1) has pharmacologic applications in the field of antiglaucoma, anticonvulsant, antiobesity, and anticancer agents but is also emerging for designing anti-infectives (antifungal and antibacterial agents) with a novel mechanism of action. As a consequence, the drug design of CA inhibitors (CAIs) is a very dynamic field. Sulfonamides and their isosteres (sulfamates/sulfamides) constitute the main class of CAIs which bind to the metal ion in the enzyme active site. Recently the dithiocarbamates, possessing a similar mechanism of action, were reported as a new class of inhibitors. Other families of CAIs possess a distinct mechanism of action: phenols, polyamines, some carboxylates, and sulfocoumarins anchor to the zinc-coordinated water molecule. Coumarins and five/six-membered lactones are prodrug inhibitors, binding in hydrolyzed form at the entrance of the active site cavity. Novel drug design strategies have been reported principally based on the tail approach for obtaining all these types of CAIs, which exploit more external binding regions within the enzyme active site (in addition to coordination to the metal ion), leading thus to isoform-selective compounds. Sugar-based tails as well as click chemistry were the most fruitful developments of the tail approach. Promising compounds that inhibit CAs from bacterial and fungal pathogens, of the dithiocarbamate, phenol and carboxylate types have also been reported. PMID:24146385

  2. Inhibitors of protein kinase C

    Institute of Scientific and Technical Information of China (English)

    LIU Shiying; JIANG Yuyang; CAO Jian; LIU Feng; MA Li; ZHAO Yufen

    2005-01-01

    Protein kinase catalyzes the transfer of the γ-phosphoryl group from ATP to the hydroxyl groups of protein side chains, which plays critical roles in signal transduction pathways by transmitting extracellular signals across the plasma membrane and nuclear membrane to the destination sites in the cytoplasm and the nucleus. Protein kinase C (PKC) is a superfamily of phospholipid-dependent Ser/Thr kinase. There are at least 12 isozymes in PKC family. They are distributed in different tissues and play different roles in physiological processes. On account of their concern with a variety of pathophysiologic states, such as cancer, inflammatory conditions, autoimmune disorder, and cardiac diseases, the inhibitors, which can inhibit the activity of PKC and the interaction of cytokine with receptor, and interfere signal transduction pathway, may be candidates of therapeutic drugs. Therefore, intense efforts have been made to develop specific protein kinase inhibitors as biological tools and therapeutic agents. This article reviews the recent development of some of PKC inhibitors based on their interaction with different conserved domains and different inhibition mechanisms.

  3. The burden of inhibitors in haemophilia patients.

    Science.gov (United States)

    Walsh, Christopher E; Jiménez-Yuste, Víctor; Auerswald, Guenter; Grancha, Salvador

    2016-08-31

    The burden of disease in haemophilia patients has wide ranging implications for the family and to society. There is evidence that having a current inhibitor increases the risk of morbidity and mortality. Morbidity is increased by the inability to treat adequately and its consequent disabilities, which then equates to a poor quality of life compared with non-inhibitor patients. The societal cost of care, or `burden of inhibitors', increases with the ongoing presence of an inhibitor. Therefore, it is clear that successful eradication of inhibitors by immune tolerance induction (ITI) is the single most important milestone one can achieve in an inhibitor patient. The type of factor VIII (FVIII) product used in ITI regimens varies worldwide. Despite ongoing debate, there is in vitro and retrospective clinical evidence to support the use of plasma-derived VWF-containing FVIII concentrates in ITI regimens in order to achieve early and high inhibitor eradication success rates. PMID:27528280

  4. Tissue Inhibitor of Metalloproteinase-4 Triggers Apoptosis in Cervical Cancer Cells.

    Science.gov (United States)

    Lizarraga, Floria; Ceballos-Cancino, Gisela; Espinosa, Magali; Vazquez-Santillan, Karla; Maldonado, Vilma; Melendez-Zajgla, Jorge

    2015-01-01

    Tissue inhibitor of metalloproteinase-4 (TIMP-4) is a member of extracellular matrix (ECM) metalloproteinases inhibitors that has pleiotropic functions. However, TIMP-4 roles in carcinogenesis are not well understood. Cell viability and flow cytometer assays were employed to evaluate cell death differences between H-Vector and H-TIMP-4 cell lines. Immunobloting and semi-quantitative RT-PCR were used to evaluate the expression of apoptosis regulators. We showed that TIMP-4 has apoptosis-sensitizing effects towards several death stimuli. Consistent with these findings, regulators of apoptosis from Inhibitors of Apoptosis Proteins (IAP), FLICE-like inhibitor proteins (FLIP) and Bcl-2 family members were modulated by TIMP-4. In addition, TIMP-4 knockdown resulted in cell survival increase after serum deprivation, as assessed by clonogenic cell analyses. This report shows that TIMP-4 regulates carcinogenesis through apoptosis activation in cervical cancer cells. Understanding TIMP-4 effects in tumorigenesis may provide clues for future therapies.

  5. Tissue Inhibitor of Metalloproteinase-4 Triggers Apoptosis in Cervical Cancer Cells.

    Directory of Open Access Journals (Sweden)

    Floria Lizarraga

    Full Text Available Tissue inhibitor of metalloproteinase-4 (TIMP-4 is a member of extracellular matrix (ECM metalloproteinases inhibitors that has pleiotropic functions. However, TIMP-4 roles in carcinogenesis are not well understood. Cell viability and flow cytometer assays were employed to evaluate cell death differences between H-Vector and H-TIMP-4 cell lines. Immunobloting and semi-quantitative RT-PCR were used to evaluate the expression of apoptosis regulators. We showed that TIMP-4 has apoptosis-sensitizing effects towards several death stimuli. Consistent with these findings, regulators of apoptosis from Inhibitors of Apoptosis Proteins (IAP, FLICE-like inhibitor proteins (FLIP and Bcl-2 family members were modulated by TIMP-4. In addition, TIMP-4 knockdown resulted in cell survival increase after serum deprivation, as assessed by clonogenic cell analyses. This report shows that TIMP-4 regulates carcinogenesis through apoptosis activation in cervical cancer cells. Understanding TIMP-4 effects in tumorigenesis may provide clues for future therapies.

  6. Structural Basis for Accelerated Cleavage of Bovine Pancreatic Trypsin Inhibitor (BPTI) by Human Mesotrypsin

    Energy Technology Data Exchange (ETDEWEB)

    Salameh,M.; Soares, A.; Hockla, A.; Radisky, E.

    2008-01-01

    Human mesotrypsin is an isoform of trypsin that displays unusual resistance to polypeptide trypsin inhibitors and has been observed to cleave several such inhibitors as substrates. Whereas substitution of arginine for the highly conserved glycine 193 in the trypsin active site has been implicated as a critical factor in the inhibitor resistance of mesotrypsin, how this substitution leads to accelerated inhibitor cleavage is not clear. Bovine pancreatic trypsin inhibitor (BPTI) forms an extremely stable and cleavage-resistant complex with trypsin, and thus provides a rigorous challenge of mesotrypsin catalytic activity toward polypeptide inhibitors. Here, we report kinetic constants for mesotrypsin and the highly homologous (but inhibitor sensitive) human cationic trypsin, describing inhibition by, and cleavage of BPTI, as well as crystal structures of the mesotrypsin-BPTI and human cationic trypsin-BPTI complexes. We find that mesotrypsin cleaves BPTI with a rate constant accelerated 350-fold over that of human cationic trypsin and 150,000-fold over that of bovine trypsin. From the crystal structures, we see that small conformational adjustments limited to several side chains enable mesotrypsin-BPTI complex formation, surmounting the predicted steric clash introduced by Arg-193. Our results show that the mesotrypsin-BPTI interface favors catalysis through (a) electrostatic repulsion between the closely spaced mesotrypsin Arg-193 and BPTI Arg-17, and (b) elimination of two hydrogen bonds between the enzyme and the amine leaving group portion of BPTI. Our model predicts that these deleterious interactions accelerate leaving group dissociation and deacylation.

  7. Effects of bisphenol A-related diphenylalkanes on vitellogenin production in male carp (Cyprinus carpio) hepatocytes and aromatase (CYP19) activity in human H295r adrenocortical carcinoma cells

    International Nuclear Information System (INIS)

    The present study investigated the effects of the known xenoestrogen bisphenol A (BPA) relative to eight BPA-related diphenylalkanes on estrogen receptor (ER)-mediated vitellogenin (vtg) production in hepatocytes from male carp (Cyprinus carpio), and on aromatase (CYP19) activity in the human adrenocortical H295R carcinoma cell line. Of the eight diphenylalkanes, only 4,4'-(hexafluoropropylidene)diphenol (BHF) and 2,2'-bis(4-hydroxy-3-methylphenyl)propane (BPRO) induced vtg, i.e., to a maximum of 3% to 4% (at 100 μM) compared with 8% for BPA relative to the maximum induction by 17β-estradiol (E2, 1 μM). Bisphenol A diglycidyl ether (BADGE) was a potent antagonist of vtg production with an IC50 of 5.5 μM, virtually 100% inhibition of vtg at 20 μM, and an inhibitive (IC50) potency about one-tenth that of the known ER antagonist tamoxifen (IC50, 0.6 μM). 2,2'-Diallyl bisphenol A, 4,4'-(1,4-phenylene-diisopropylidene)bisphenol, BPRO, and BHF were much less inhibitory with IC50 concentrations of 20-70 μM, and relative potencies of 0.03 and 0.009 with tamoxifen. Bisphenol ethoxylate showed no anti-estrogenicity (up to 100 μM), and 4,4'-isopropylidene-diphenol diacetate was only antagonistic at 100 μM. When comparing the (anti)estrogenic potencies of these bisphenol A analogues/diphenylalkanes, anti-estrogenicity occurred at lower concentrations than estrogenicity. 4,4'-Isopropylidenebis(2,6-dimethylphenol) (IC50, 2.0 μM) reduced E2-induced (EC50, 100 nM) vtg production due to concentration-dependent cytotoxicity as indicated by a parallel decrease in MTT activity and vtg, whereas the remaining diphenylalkanes did not cause any cytotoxicity relative to controls. None of the diphenylalkanes (up to 100 μM) induced EROD activity indicating that concentration-dependent, CYP1A enzyme-mediated metabolism of E2, or any Ah-receptor-mediated interaction with the ER, was not a likely explanation for the observed anti-estrogenic effects. At concentrations as great as 100

  8. Proton pump inhibitors and risk of dementia

    Science.gov (United States)

    Thongprayoon, Charat; Panjawatanan, Panadeekarn; Ungprasert, Patompong

    2016-01-01

    Background Proton pump inhibitors (PPIs) are one of the most commonly prescribed medications. Recent studies have raised a concern over increased risk of dementia among PPIs users but the results of those studies were inconsistent. We conducted this systematic review and meta-analysis to summarize all available data. Methods A literature search was performed in MEDLINE and EMBASE database from inception to April 2016. Observational studies that reported risk of dementia among PPIs users compared with non-users were included. Point estimates were extracted from individual studies and pooled risk ratios (RR) with 95% confidence intervals (CI) were calculated using a random-effect, generic inverse variance method. Results Four studies were included in the analysis. Pooled RR of dementia among PPIs users compared with non-users was 1.08 (95% CI, 0.82–1.43). Sensitivity analysis including only cohort studies demonstrated a higher risk with pooled RR of 1.44 (95% CI, 1.36–1.52). Conclusions Our study demonstrated an increased risk of dementia among PPIs users. Whether this association is causal requires further investigations. PMID:27429966

  9. Bioanalysis and pharmacokinetics of the p38 MAPkinase inhibitor SB202190 in rats

    NARCIS (Netherlands)

    Prakash, Jai; Saluja, Vinay; Visser, Jan; Moolenaar, Frits; Meijer, D.K F; Poelstra, Klaas; Kok, R.J

    2005-01-01

    We have developed a sensitive and reproducible high performance liquid chromatography (HPLC)-UV method for the quantification of the p38 MAPkinase inhibitor SB202190 in serum, kidney homogenates and urine samples. Liquid-liquid extraction of SB202190 from the samples was performed using diethylether

  10. How sensitizing is chlorocresol?

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Hamann, K

    1984-01-01

    Chlorocresol is a biocide with widespread use in industry and pharmaceutical products. It is an occasional human contact sensitizer. The sensitizing potential of chlorocresol was judged strong using the guinea pig maximization test (GPMT) and doubtful in the less sensitive open epicutaneous test...

  11. Combining oral contraceptives with a natural nuclear factor-kappa B inhibitor for the treatment of endometriosis-related pain

    Directory of Open Access Journals (Sweden)

    Maia H Jr

    2013-12-01

    Full Text Available Hugo Maia Jr,1–3 Clarice Haddad,3 Julio Casoy3 1Department of Gynecology and Obstetrics, School of Medicine, Federal University of Bahia, 2Itaigara Memorial Day Hospital, 3Centro de Pesquisas e Assistência em Reprodução Humana (CEPARH, Salvador, Bahia, Brazil Abstract: Endometriosis is a chronic disease in which a persistent state of heightened inflammation is maintained by nuclear factor-kappa B (NF-κB activation. The progestins present in oral contraceptives are potent inhibitors of NF-κB translocation to cell nuclei, while Pycnogenol® (Pinus pinaster acts by blocking post-translational events. In this study, the effects of Pycnogenol on pain scores were investigated in patients with endometriosis using oral contraceptives containing either gestodene or drospirenone in extended regimens. Pain scores were determined using a visual analog scale before and after 3 months of treatment. Oral contraceptives, used alone (groups 1 and 3 or in association with Pycnogenol (groups 2 and 4, resulted in significant decreases in pain scores after 3 months of treatment; however, this reduction was significantly greater in the groups using oral contraceptives + Pycnogenol (groups 2 and 4 compared with those using oral contraceptives alone (groups 1 and 3. In the groups using oral contraceptives alone, 50% of patients became pain-free by the end of the third month of treatment. These results suggest that Pycnogenol increases the efficacy of oral contraceptives for the treatment of endometriosis-related pain. Keywords: Pycnogenol®, aromatase, endometriosis, nuclear factor-kappa B

  12. Synergistic interactions between HDAC and sirtuin inhibitors in human leukemia cells.

    Directory of Open Access Journals (Sweden)

    Michele Cea

    Full Text Available Aberrant histone deacetylase (HDAC activity is frequent in human leukemias. However, while classical, NAD(+-independent HDACs are an established therapeutic target, the relevance of NAD(+-dependent HDACs (sirtuins in leukemia treatment remains unclear. Here, we assessed the antileukemic activity of sirtuin inhibitors and of the NAD(+-lowering drug FK866, alone and in combination with traditional HDAC inhibitors. Primary leukemia cells, leukemia cell lines, healthy leukocytes and hematopoietic progenitors were treated with sirtuin inhibitors (sirtinol, cambinol, EX527 and with FK866, with or without addition of the HDAC inhibitors valproic acid, sodium butyrate, and vorinostat. Cell death was quantified by propidium iodide cell staining and subsequent flow-cytometry. Apoptosis induction was monitored by cell staining with FITC-Annexin-V/propidium iodide or with TMRE followed by flow-cytometric analysis, and by measuring caspase3/7 activity. Intracellular Bax was detected by flow-cytometry and western blotting. Cellular NAD(+ levels were measured by enzymatic cycling assays. Bax was overexpressed by retroviral transduction. Bax and SIRT1 were silenced by RNA-interference. Sirtuin inhibitors and FK866 synergistically enhanced HDAC inhibitor activity in leukemia cells, but not in healthy leukocytes and hematopoietic progenitors. In leukemia cells, HDAC inhibitors were found to induce upregulation of Bax, a pro-apoptotic Bcl2 family-member whose translocation to mitochondria is normally prevented by SIRT1. As a result, leukemia cells become sensitized to sirtuin inhibitor-induced apoptosis. In conclusion, NAD(+-independent HDACs and sirtuins cooperate in leukemia cells to avoid apoptosis. Combining sirtuin with HDAC inhibitors results in synergistic antileukemic activity that could be therapeutically exploited.

  13. Proton pump inhibitors and osteoporosis

    DEFF Research Database (Denmark)

    Andersen, Bjarne Nesgaard; Johansen, Per Birger; Abrahamsen, Bo

    2016-01-01

    PURPOSE OF REVIEW: The purpose of the review is to provide an update on recent advances in the evidence based on proton pump inhibitors (PPI) as a possible cause of osteoporosis and osteoporotic fractures. This review focuses, in particular, on new studies published in the last 18 months and a di......PURPOSE OF REVIEW: The purpose of the review is to provide an update on recent advances in the evidence based on proton pump inhibitors (PPI) as a possible cause of osteoporosis and osteoporotic fractures. This review focuses, in particular, on new studies published in the last 18 months...... and a discussion of these findings and how this has influenced our understanding of this association, the clinical impact and the underlying pathophysiology. RECENT FINDINGS: New studies have further strengthened existing evidence linking use of PPIs to osteoporosis. Short-term use does not appear to pose a lower...... risk than long-term use. There is a continued lack of conclusive studies identifying the pathogenesis. Direct effects on calcium absorption or on osteoblast or osteoclast action cannot at present plausibly explain the mechanism. SUMMARY: The use of PPIs is a risk factor for development of osteoporosis...

  14. Inhibitors of Acetylcholinesterase and Butyrylcholinesterase Meet Immunity

    OpenAIRE

    Miroslav Pohanka

    2014-01-01

    Acetylcholinesterase (AChE) inhibitors are widely used for the symptomatic treatment of Alzheimer’s disease and other dementias. More recent use is for myasthenia gravis. Many of these inhibitors interact with the second known cholinesterase, butyrylcholinesterase (BChE). Further, evidence shows that acetylcholine plays a role in suppression of cytokine release through a “cholinergic anti-inflammatory pathway” which raises questions about the role of these inhibitors in the immune system. Thi...

  15. Influenza neuraminidase inhibitors: antiviral action and mechanisms of resistance

    Science.gov (United States)

    McKimm‐Breschkin, Jennifer L.

    2012-01-01

    Please cite this paper as: McKimm‐Breschkin (2012) Influenza neuraminidase inhibitors: Antiviral action and mechanisms of resistance. Influenza and Other Respiratory Viruses 7(Suppl. 1), 25–36. There are two major classes of antivirals available for the treatment and prevention of influenza, the M2 inhibitors and the neuraminidase inhibitors (NAIs). The M2 inhibitors are cheap, but they are only effective against influenza A viruses, and resistance arises rapidly. The current influenza A H3N2 and pandemic A(H1N1)pdm09 viruses are already resistant to the M2 inhibitors as are many H5N1 viruses. There are four NAIs licensed in some parts of the world, zanamivir, oseltamivir, peramivir, and a long‐acting NAI, laninamivir. This review focuses on resistance to the NAIs. Because of differences in their chemistry and subtle differences in NA structures, resistance can be both NAI‐ and subtype specific. This results in different drug resistance profiles, for example, the H274Y mutation confers resistance to oseltamivir and peramivir, but not to zanamivir, and only in N1 NAs. Mutations at E119, D198, I222, R292, and N294 can also reduce NAI sensitivity. In the winter of 2007–2008, an oseltamivir‐resistant seasonal influenza A(H1N1) strain with an H274Y mutation emerged in the northern hemisphere and spread rapidly around the world. In contrast to earlier evidence of such resistant viruses being unfit, this mutant virus remained fully transmissible and pathogenic and became the major seasonal A(H1N1) virus globally within a year. This resistant A(H1N1) virus was displaced by the sensitive A(H1N1)pdm09 virus. Approximately 0·5–1·0% of community A(H1N1)pdm09 isolates are currently resistant to oseltamivir. It is now apparent that variation in non‐active site amino acids can affect the fitness of the enzyme and compensate for mutations that confer high‐level oseltamivir resistance resulting in minimal impact on enzyme function. PMID:23279894

  16. Mechanisms Regulating Resistance to Inhibitors of Topoisomerase II

    Directory of Open Access Journals (Sweden)

    Ram eGanapathi

    2013-08-01

    Full Text Available Inhibitors of topoisomerase II are clinically effective in the management of hematological malignancies and solid tumors. The efficacy of anti-tumor drugs targeting topoisomerase II is often limited by resistance and studies with in vitro cell culture models have provided several insights on potential mechanisms. Multidrug-transporters that are involved in the efflux and consequently reduced cytotoxicity of diverse anti-tumor agents suggest that they play an important role in resistance to clinically active drugs. However in clinical trials, modulating the multidrug resistant phenotype with agents that inhibit the efflux pump has not had an impact. Since reduced drug accumulation per se is insufficient to explain tumor cell resistance to topoisomerase II inhibitors several studies have focused on characterizing mechanisms that impact on DNA damage mediated by drugs that target the enzyme. Mammalian topoisomerase IIα and topoisomerase IIβ isozymes exhibit similar catalytic, but different biologic, activities. Whereas topoisomerase IIα is associated with cell division, topoisomerase IIβ is involved in differentiation. In addition to site specific mutations that can affect drug induced topoisomerase II-mediated DNA damage, post-translation modification of topoisomerase II primarily by phosphorylation can potentially affect enzyme-mediated DNA damage and the downstream cytotoxic response of drugs targeting topoisomerase II. Signaling pathways that can affect phosphorylation and changes in intracellular calcium levels/calcium dependent signaling that can regulate site-specific phosphorylation of topoisomerase have an impact on downstream cytotoxic effects of topoisomerase II inhibitors. Overall, tumor cell resistance to inhibitors of topoisomerase II is a complex process that is orchestrated not only by cellular pharmacokinetics but more importantly by enzymatic alterations that govern the intrinsic drug sensitivity.

  17. Multidrug Efflux Pumps Attenuate the Effect of MGMT Inhibitors.

    Science.gov (United States)

    Tomaszowski, Karl-Heinz; Schirrmacher, Ralf; Kaina, Bernd

    2015-11-01

    Various mechanisms of drug resistance attenuate the effectiveness of cancer therapeutics, including drug transport and DNA repair. The DNA repair protein O(6)-methylguanine-DNA methyltransferase (MGMT) is a key factor determining the resistance against alkylating anticancer drugs inducing the genotoxic DNA lesions O(6)-methylguanine and O(6)-chloroethylguanine, and MGMT inactivation or depletion renders cells more susceptible to treatment with methylating and chloroethylating agents. Highly specific and efficient inhibitors of the repair protein MGMT were designed, including O(6)-benzylguanine (O(6)BG) and O(6)-(4-bromothenyl)guanine (O(6)BTG) that are nontoxic on their own. Unfortunately, these inhibitors do not select between MGMT in normal and cancer cells, causing nontarget effects in the healthy tissue. Therefore, a targeting strategy for MGMT inhibitors is required. Here, we used O(6)BG and O(6)BTG conjugated to β-d-glucose (O(6)BG-Glu and O(6)BTG-Glu, respectively) in order to selectively inhibit MGMT in tumors, harnessing their high demand for glucose. Both glucose conjugates efficiently inhibited MGMT in several cancer cell lines, but with different extents of sensitization to DNA alkylating agents, with lomustine being more effective than temozolomide. We further show that the glucose conjugates are subject to ATP-binding cassette (ABC) transporter mediated efflux, involving P-glycoprotein, MRP1, and BCRP, which impacts the efficiency of MGMT inhibition. Surprisingly, also O(6)BG and O(6)BTG were subject to an active transport out of the cell. We also show that pharmacological inhibition of efflux transporters increases the induction of cell death following treatment with these MGMT inhibitors and temozolomide. We conclude that strategies of attenuating the efflux by ABC transporters are required for achieving successful MGMT targeting. PMID:26379107

  18. Context Sensitive Modeling of Cancer Drug Sensitivity

    Science.gov (United States)

    Chen, Bo-Juen; Litvin, Oren; Ungar, Lyle; Pe’er, Dana

    2015-01-01

    Recent screening of drug sensitivity in large panels of cancer cell lines provides a valuable resource towards developing algorithms that predict drug response. Since more samples provide increased statistical power, most approaches to prediction of drug sensitivity pool multiple cancer types together without distinction. However, pan-cancer results can be misleading due to the confounding effects of tissues or cancer subtypes. On the other hand, independent analysis for each cancer-type is hampered by small sample size. To balance this trade-off, we present CHER (Contextual Heterogeneity Enabled Regression), an algorithm that builds predictive models for drug sensitivity by selecting predictive genomic features and deciding which ones should—and should not—be shared across different cancers, tissues and drugs. CHER provides significantly more accurate models of drug sensitivity than comparable elastic-net-based models. Moreover, CHER provides better insight into the underlying biological processes by finding a sparse set of shared and type-specific genomic features. PMID:26274927

  19. Context Sensitive Modeling of Cancer Drug Sensitivity.

    Directory of Open Access Journals (Sweden)

    Bo-Juen Chen

    Full Text Available Recent screening of drug sensitivity in large panels of cancer cell lines provides a valuable resource towards developing algorithms that predict drug response. Since more samples provide increased statistical power, most approaches to prediction of drug sensitivity pool multiple cancer types together without distinction. However, pan-cancer results can be misleading due to the confounding effects of tissues or cancer subtypes. On the other hand, independent analysis for each cancer-type is hampered by small sample size. To balance this trade-off, we present CHER (Contextual Heterogeneity Enabled Regression, an algorithm that builds predictive models for drug sensitivity by selecting predictive genomic features and deciding which ones should-and should not-be shared across different cancers, tissues and drugs. CHER provides significantly more accurate models of drug sensitivity than comparable elastic-net-based models. Moreover, CHER provides better insight into the underlying biological processes by finding a sparse set of shared and type-specific genomic features.

  20. Localization of aromatase in the nervous system, Hatschek's pit and gonad of amphioxus by in situ hybridization and immunocytochemistry%芳香化酶在文昌鱼神经系统、哈氏窝和性腺特异性定位:原位杂交和免疫细胞化学研究

    Institute of Scientific and Technical Information of China (English)

    方永强; 翁幼竹; 黄威权; 孙岚

    2003-01-01

    芳香化酶活性发现在脊椎动物脑、脑垂体和性腺中,但在文昌鱼脑和哈氏窝的组织特异性定位尚无可利用资料.本文用免疫细胞化学和原位杂交技术,首次发现芳香化酶活性组织特异性定位在幼年和性腺发育不同时期雌、雄文昌鱼神经系统(脑和脊髓)、轮器、哈氏窝和性腺中.芳香化酶蛋白和转录物在前脑、中脑、脊髓、轮器和哈氏窝十分丰富,而后脑、早期卵巢和精巢不够丰富;没有芳香化酶表达的部位是哈氏窝另两种细胞(不规则形细胞和带纤毛粘液细胞)以及成熟卵巢和精巢;芳香化酶免疫活性物质分布在胞质,核为阴性.芳香化酶在文昌鱼神经系统、哈氏窝和性腺的分布模式与低等脊椎动物中的分布模式极为类似,尤其是芳香化酶在脑内调节哈氏窝分泌活动的神经内分泌中枢表达,并形成类似脊椎动物的文昌鱼原始的脑-芳香化酶调节系统.这些结果有力地证明,文昌鱼脑和哈氏窝高水平的芳香化酶活性像在其它脊椎动物中一样,对局部介导睾酮芳香化起着关键作用,同时还可能影响脑-芳香化酶系统参与调节哈氏窝的分泌活动[动物学报49(6):800~806,2003].%Aromatase activity has been found in the brain and pituitary as well as gonads of vertebrates, but no information is available on the specific localization in the brain and Hatschek's pit (primitive pituitary) of amphioxus (Branchios-toma belcheri). Using immunocytochemistry and in situ hybridization, we studied definitive tissue specific localization of aromatase in the nervous system (brain and spinal cord), wheel organ, Hatschek's pit and gonads at young and adult female and male amphioxus at different stages of gonadal development. Aromatase protein and its mRNA were abundant in the forebrain, midbrain, spinal cord, wheel organ and Hatschek's pit, but not abundant in the hindbrain or early ovary and testis. No aromatase expression

  1. Targeting the AKT pathway: Repositioning HIV protease inhibitors as radiosensitizers

    Directory of Open Access Journals (Sweden)

    Jayant S Goda

    2016-01-01

    Full Text Available Cellular resistance in tumour cells to different therapeutic approaches has been a limiting factor in the curative treatment of cancer. Resistance to therapeutic radiation is a common phenomenon which significantly reduces treatment options and impacts survival. One of the mechanisms of acquiring resistance to ionizing radiation is the overexpression or activation of various oncogenes like the EGFR (epidermal growth factor receptor, RAS (rat sarcoma oncogene or loss of PTEN (phosphatase and tensin homologue which in turn activates the phosphatidyl inositol 3-kinase/protein kinase B (PI3-K/AKT pathway responsible for radiation resistance in various tumours. Blocking the pathway enhances the radiation response both in vitro and in vivo. Due to the differential activation of this pathway (constitutively activated in tumour cells and not in the normal host cells, it is an excellent candidate target for molecular targeted therapy to enhance radiation sensitivity. In this regard, HIV protease inhibitors (HPIs known to interfere with PI3-K/AKT signaling in tumour cells, have been shown to sensitize various tumour cells to radiation both in vitro and in vivo. As a result, HPIs are now being investigated as possible radiosensitizers along with various chemotherapeutic drugs. This review describes the mechanisms by which PI3-K/AKT pathway causes radioresistance and the role of HIV protease inhibitors especially nelfinavir as a potential candidate drug to target the AKT pathway for overcoming radioresistance and its use in various clinical trials for different malignancies.

  2. Targeting the AKT pathway: Repositioning HIV protease inhibitors as radiosensitizers.

    Science.gov (United States)

    Goda, Jayant S; Pachpor, Tejaswini; Basu, Trinanjan; Chopra, Supriya; Gota, Vikram

    2016-02-01

    Cellular resistance in tumour cells to different therapeutic approaches has been a limiting factor in the curative treatment of cancer. Resistance to therapeutic radiation is a common phenomenon which significantly reduces treatment options and impacts survival. One of the mechanisms of acquiring resistance to ionizing radiation is the overexpression or activation of various oncogenes like the EGFR (epidermal growth factor receptor), RAS (rat sarcoma) oncogene or loss of PTEN (phosphatase and tensin homologue) which in turn activates the phosphatidyl inositol 3-kinase/protein kinase B (PI3-K)/AKT pathway responsible for radiation resistance in various tumours. Blocking the pathway enhances the radiation response both in vitro and in vivo. Due to the differential activation of this pathway (constitutively activated in tumour cells and not in the normal host cells), it is an excellent candidate target for molecular targeted therapy to enhance radiation sensitivity. In this regard, HIV protease inhibitors (HPIs) known to interfere with PI3-K/AKT signaling in tumour cells, have been shown to sensitize various tumour cells to radiation both in vitro and in vivo. As a result, HPIs are now being investigated as possible radiosensitizers along with various chemotherapeutic drugs. This review describes the mechanisms by which PI3-K/AKT pathway causes radioresistance and the role of HIV protease inhibitors especially nelfinavir as a potential candidate drug to target the AKT pathway for overcoming radioresistance and its use in various clinical trials for different malignancies.

  3. Advances in Inhibitors of FXa.

    Science.gov (United States)

    Guo, Liwei; Ma, Shutao

    2015-01-01

    Thromboembolic diseases such as deep vein thrombosis (DVT), pulmonary embolism (PE), myocardial infarction (MI) and ischemic strokes are mainly responsible for people's morbidity and mortality and have severely affected the people's quality of life all over the world. According to WHO statistics, an average of 17 million people are killed by the thromboembolic diseases each year globally. Therefore, the prevention and treatment of thromboembolic diseases have received widespread attention in recent years. Based on thrombotic mechanism, anti-thrombotic drugs are mainly divided into anticoagulants, antiplatelet agents and direct thrombolytic drugs. In particular, anticoagulants such as vitamin K antagonists (VKAs), unfractionated heparin (UFH), and low-molecular-weight heparins (LMWHs) have become the main therapies for pre-treatment of thromboembolic disorders. However, the limitations of traditional anticoagulants such as slow onset of action, dose-adjusted requirement, drug-drug and drug-food interactions have restricted their improvement in the clinical treatment. The mechanism of the thromboembolic disorders has indicated that coagulation factor Xa (fXa) plays a pivotal role in the blood coagulation cascade. Thus, selective inhibition of fXa by diminishing the amplified generation of thrombin without affecting the pre-existing thrombin levels can provide better antithrombotic effect, thereby causing less impairment of primary hemostasis. In this paper, we mainly introduce the recent advances of fXa inhibitors, with focus on their biological activity and structure-activity relationship (SAR) information. In particular, the inspirations from the structures of the fXa inhibitors and their future direction are highlighted. PMID:25981610

  4. Sensitivity and uncertainty analysis

    CERN Document Server

    Cacuci, Dan G; Navon, Ionel Michael

    2005-01-01

    As computer-assisted modeling and analysis of physical processes have continued to grow and diversify, sensitivity and uncertainty analyses have become indispensable scientific tools. Sensitivity and Uncertainty Analysis. Volume I: Theory focused on the mathematical underpinnings of two important methods for such analyses: the Adjoint Sensitivity Analysis Procedure and the Global Adjoint Sensitivity Analysis Procedure. This volume concentrates on the practical aspects of performing these analyses for large-scale systems. The applications addressed include two-phase flow problems, a radiative c

  5. Sectional global sensitivity measures

    International Nuclear Information System (INIS)

    In this paper the approach of sectional sensitivity measures is introduced. Opposite to well-known global sensitivity measures not only a singleton value is provided to appraise the functional input–output interrelation but rather a more detailed description of these interrelation is enabled. Therefore, the domain of definition (input space) and/or the codomain (result space) are subdivided in a finite number of subdomains/subranges. The evaluation of global sensitivity measures in these subdomains/subranges allows for a proper appraisal of the functional interrelation in local regions. The theoretic background of sectional sensitivity measures is elaborated in detail and exemplified by means of analytical functions. The advantages of sectional sensitivity measures are discussed by means of a medical intervention planning of a radio frequency ablation. - Highlights: • Global sensitivity measures provide just a singleton value per input dimension. • Sectional sensitivity measures enable evaluation of functional interrelation. • Subdivision of input and output in intervals (subdomains). • Usage of absolute partial derivatives as sensitivity measure. • Regional sensitivity statements in input as well as in output space possible

  6. Potent and Selective Inhibition of Plasma Membrane Monoamine Transporter by HIV Protease Inhibitors.

    Science.gov (United States)

    Duan, Haichuan; Hu, Tao; Foti, Robert S; Pan, Yongmei; Swaan, Peter W; Wang, Joanne

    2015-11-01

    Plasma membrane monoamine transporter (PMAT) is a major uptake-2 monoamine transporter that shares extensive substrate and inhibitor overlap with organic cation transporters 1-3 (OCT1-3). Currently, there are no PMAT-specific inhibitors available that can be used in in vitro and in vivo studies to differentiate between PMAT and OCT activities. In this study, we showed that IDT307 (4-(4-(dimethylamino)phenyl)-1-methylpyridinium iodide), a fluorescent analog of 1-methyl-4-phenylpyridinium (MPP+), is a transportable substrate for PMAT and that IDT307-based fluorescence assay can be used to rapidly identify and characterize PMAT inhibitors. Using the fluorescent substrate-based assays, we analyzed the interactions of eight human immunodeficiency virus (HIV) protease inhibitors (PIs) with human PMAT and OCT1-3 in human embryonic kidney 293 (HEK293) cells stably transfected with individual transporters. Our data revealed that PMAT and OCTs exhibit distinct sensitivity and inhibition patterns toward HIV PIs. PMAT is most sensitive to PI inhibition whereas OCT2 and OCT3 are resistant. OCT1 showed an intermediate sensitivity and a distinct inhibition profile from PMAT. Importantly, lopinavir is a potent PMAT inhibitor and exhibited >120 fold selectivity toward PMAT (IC₅₀ = 1.4 ± 0.2 µM) over OCT1 (IC₅₀ = 174 ± 40 µM). Lopinavir has no inhibitory effect on OCT2 or OCT3 at maximal tested concentrations. Lopinavir also exhibited no or much weaker interactions with uptake-1 monoamine transporters. Together, our results reveal that PMAT and OCTs have distinct specificity exemplified by their differential interaction with HIV PIs. Further, we demonstrate that lopinavir can be used as a selective PMAT inhibitor to differentiate PMAT-mediated monoamine and organic cation transport from those mediated by OCT1-3. PMID:26285765

  7. Alkylamino derivatives of 4-aminomethylpyridine as inhibitors of copper-containing amine oxidases.

    Science.gov (United States)

    Bertini, Vincenzo; Buffoni, Franca; Ignesti, Giovanni; Picci, Nevio; Trombino, Sonia; Iemma, Francesca; Alfei, Silvana; Pocci, Marco; Lucchesini, Francesco; De Munno, Angela

    2005-02-10

    The first substratelike, reversible inhibitors of different copper amine oxidases (CAOs) with IC50 (M) as low as 2.0 x 10(-8) corresponding to derivatives of 4-aminomethylpyridine with alkoxy (1a-d), alkylthio (2a,b), and alkylamino (3a-e, 4a-j) groups in the positions 3 and 5 have been prepared and studied. The inhibitors 1a-d are active on benzylamine oxidase and semicarbazide-sensitive amine oxidase and are very selective with respect to diamine oxidase, lysyl oxidase, and monoamine oxidases. The inhibitors 2a,b are selective for benzylamine oxidase whereas 2a is also a new type of good substrate of diamine oxidase. The inhibitors 3a-e and 4a-j are substratelike, reversible, nonselective inhibitors of various CAOs including pea seedling amine oxidase and Hansenula polymorpha amine oxidase, whose enzymatic sites are known from X-ray structure determinations. The inhibitors 3b,c and 4b,c are excellent substratelike tools for studies correlating CAOs that afford crystals suitable for X-ray structure determinations with CAOs from mammals.

  8. Improvement of social adaptation in depression with serotonin and norepinephrine reuptake inhibitors

    Directory of Open Access Journals (Sweden)

    Mike Briley

    2010-09-01

    Full Text Available Mike Briley, Chantal MoretNeuroBiz Consulting and Communication, Castres, FranceAbstract: Depression is a disabling condition resulting in significant impairment in social functioning, involving the patient’s family, friends, work colleagues, and society at large. Although both psychologic and pharmacologic treatments generally improve many depressive symptoms, they do not always result in significant improvement in social functioning. The importance of recovery of social functioning in depressed patients is now widely appreciated, and studies are beginning to include it in evaluations of therapeutic efficacy. Among the various social adjustment evaluation rating scales, the Social Adaptation Self-Evaluation Scale, a social motivation and behavior scale, has been found to be simple to use and sensitive to change. Using this scale, the selective norepinephrine reuptake inhibitor, reboxetine, has been shown to be significantly more effective in improving social functioning than the selective serotonin reuptake inhibitor, fluoxetine. These findings are consistent with the notion that improvement in social adaptation involves functions depending primarily on noradrenergic neurotransmission. This hypothesis suggests that the serotonin and norepinephrine reuptake inhibitors, venlafaxine, duloxetine, and milnacipran, could be particularly helpful in improving social functioning. Preliminary studies with the serotonin and norepinephrine reuptake inhibitors suggest that they significantly improve social functioning. Comparative studies with selective serotonin reuptake inhibitors on the effects on social functioning should be encouraged.Keywords: Social Adaptation Self-Evaluation Scale, social functioning, depression, serotonin and norepinephrine reuptake inhibitors, noradrenergic neurotransmission

  9. Angiotensin converting enzyme inhibitor induced hyperkalaemic paralysis

    OpenAIRE

    Dutta., D; Fischler, M; McClung, A

    2001-01-01

    Secondary hyperkalaemic paralysis is a rare condition often mimicking the Guillain-Barré syndrome. There have been a few case reports of hyperkalaemia caused by renal failure, trauma, and drugs where the presentation has been with muscle weakness. A case of hyperkalaemic paralysis caused by an angiotensin converting enzyme inhibitor is reported.


Keywords: hyperkalaemia; paralysis; ACE inhibitors

  10. [Interaction between clopidogrel and proton pump inhibitors

    NARCIS (Netherlands)

    Harmsze, A.M.; Boer, A. de; Boot, H.; Deneer, V.H.; Heringa, M.; Mol, P.G.; Schalekamp, T.; Verduijn, M.M.; Verheugt, F.W.A.; Comte, M. le

    2011-01-01

    The drug interaction between proton pump inhibitors and clopidogrel has been the subject of much study in recent years. Contradictory results regarding the effect of proton pump inhibitors on platelet reactivity and on clinical outcome in clopidogrel-treated patients have been reported in literature

  11. Does plasminogen activator inhibitor-1 drive lymphangiogenesis?

    DEFF Research Database (Denmark)

    Bruyère, Françoise; Melen-Lamalle, Laurence; Blacher, Silvia;

    2010-01-01

    The purpose of this study is to explore the function of plasminogen activator inhibitor-1 (PAI-1) during pathological lymphangiogenesis. PAI-1, the main physiological inhibitor of plasminogen activators is involved in pathological angiogenesis at least by controlling extracellular proteolysis and...

  12. Advances of Inhibitors in Drilling Fluid

    Institute of Scientific and Technical Information of China (English)

    杨仕伟; 周丹

    2012-01-01

    The development history of the inhibitors of drilling fluid reviewed in this paper. The advances of inhibitors commonly used at home and abroad were included. That the inhibitive ability was good enough whose inhibiting mechanisms and effects were introduced in the past 10 years.

  13. Intellectual property issues of immune checkpoint inhibitors.

    Science.gov (United States)

    Storz, Ulrich

    2016-01-01

    Immune checkpoint inhibitors are drugs that interfere with tumor escape responses. Some members of this class are already approved, and expected to be blockbusters in the future. Many companies have developed patent activities in this field. This article focuses on the patent landscape, and discusses key players and cases related to immune checkpoint inhibitors. PMID:26466763

  14. Screening for potential inhibitors of influenza neuraminidase

    Institute of Scientific and Technical Information of China (English)

    Ai-linLIU; Guan-huaDU

    2004-01-01

    AIM: Applying the assay method of neuraminidase(NA) activity established for high throughput screening to find novel inhibitors of influenza virus NA. METHODS: Firstly, a virtual screening strategy was applied to our compound database to select drug-like compounds, and then a high throughput screening model of NA inhibitor was applied to test these compounds. RESULTS:

  15. Allosteric small-molecule kinase inhibitors

    DEFF Research Database (Denmark)

    Wu, Peng; Clausen, Mads Hartvig; Nielsen, Thomas E.

    2015-01-01

    -molecule allosteric inhibitor trametinib in 2013, the progress of more than 10 other allosteric inhibitors in clinical trials, and the emergence of a pipeline of highly selective and potent preclinical molecules, have been reported in the past decade. In this article, we present the current knowledge on allosteric...

  16. A cyclic peptidic serine protease inhibitor

    DEFF Research Database (Denmark)

    Zhao, Baoyu; Xu, Peng; Jiang, Longguang;

    2014-01-01

    Peptides are attracting increasing interest as protease inhibitors. Here, we demonstrate a new inhibitory mechanism and a new type of exosite interactions for a phage-displayed peptide library-derived competitive inhibitor, mupain-1 (CPAYSRYLDC), of the serine protease murine urokinase...

  17. Agricultural Polymers as Corrosion Inhibitors

    Science.gov (United States)

    Agricultural polymers were composed of extra-cellular polysaccharides secreted by Leuconostoc mesenteroides have been shown to inhibit corrosion on corrosion-sensitive metals. The substantially pure exopolysaccharide has a general structure consisting of alpha(1-6)-linked D-glucose backbone and appr...

  18. Histone deacetylase inhibitors (HDACIs: multitargeted anticancer agents

    Directory of Open Access Journals (Sweden)

    Ververis K

    2013-02-01

    Full Text Available Katherine Ververis,1 Alison Hiong,1 Tom C Karagiannis,1,* Paul V Licciardi2,*1Epigenomic Medicine, Alfred Medical Research and Education Precinct, 2Allergy and Immune Disorders, Murdoch Childrens Research Institute, Melbourne, VIC, Australia*These authors contributed equally to this workAbstract: Histone deacetylase (HDAC inhibitors are an emerging class of therapeutics with potential as anticancer drugs. The rationale for developing HDAC inhibitors (and other chromatin-modifying agents as anticancer therapies arose from the understanding that in addition to genetic mutations, epigenetic changes such as dysregulation of HDAC enzymes can alter phenotype and gene expression, disturb homeostasis, and contribute to neoplastic growth. The family of HDAC inhibitors is large and diverse. It includes a range of naturally occurring and synthetic compounds that differ in terms of structure, function, and specificity. HDAC inhibitors have multiple cell type-specific effects in vitro and in vivo, such as growth arrest, cell differentiation, and apoptosis in malignant cells. HDAC inhibitors have the potential to be used as monotherapies or in combination with other anticancer therapies. Currently, there are two HDAC inhibitors that have received approval from the US FDA for the treatment of cutaneous T-cell lymphoma: vorinostat (suberoylanilide hydroxamic acid, Zolinza and depsipeptide (romidepsin, Istodax. More recently, depsipeptide has also gained FDA approval for the treatment of peripheral T-cell lymphoma. Many more clinical trials assessing the effects of various HDAC inhibitors on hematological and solid malignancies are currently being conducted. Despite the proven anticancer effects of particular HDAC inhibitors against certain cancers, many aspects of HDAC enzymes and HDAC inhibitors are still not fully understood. Increasing our understanding of the effects of HDAC inhibitors, their targets and mechanisms of action will be critical for the

  19. The NAE inhibitor pevonedistat interacts with the HDAC inhibitor belinostat to target AML cells by disrupting the DDR.

    Science.gov (United States)

    Zhou, Liang; Chen, Shuang; Zhang, Yu; Kmieciak, Maciej; Leng, Yun; Li, Lihong; Lin, Hui; Rizzo, Kathryn A; Dumur, Catherine I; Ferreira-Gonzalez, Andrea; Rahmani, Mohamed; Povirk, Lawrence; Chalasani, Sri; Berger, Allison J; Dai, Yun; Grant, Steven

    2016-05-01

    Two classes of novel agents, NEDD8-activating enzyme (NAE) and histone deacetylase (HDAC) inhibitors, have shown single-agent activity in acute myelogenous leukemia (AML)/myelodysplastic syndrome (MDS). Here we examined mechanisms underlying interactions between the NAE inhibitor pevonedistat (MLN4924) and the approved HDAC inhibitor belinostat in AML/MDS cells. MLN4924/belinostat coadministration synergistically induced AML cell apoptosis with or without p53 deficiency or FLT3-internal tandem duplication (ITD), whereas p53 short hairpin RNA (shRNA) knockdown or enforced FLT3-ITD expression significantly sensitized cells to the regimen. MLN4924 blocked belinostat-induced antiapoptotic gene expression through nuclear factor-κB inactivation. Each agent upregulated Bim, and Bim knockdown significantly attenuated apoptosis. Microarrays revealed distinct DNA damage response (DDR) genetic profiles between individual vs combined MLN4924/belinostat exposure. Whereas belinostat abrogated the MLN4924-activated intra-S checkpoint through Chk1 and Wee1 inhibition/downregulation, cotreatment downregulated multiple homologous recombination and nonhomologous end-joining repair proteins, triggering robust double-stranded breaks, chromatin pulverization, and apoptosis. Consistently, Chk1 or Wee1 shRNA knockdown significantly sensitized AML cells to MLN4924. MLN4924/belinostat displayed activity against primary AML or MDS cells, including those carrying next-generation sequencing-defined poor-prognostic cancer hotspot mutations, and CD34(+)/CD38(-)/CD123(+) populations, but not normal CD34(+) progenitors. Finally, combined treatment markedly reduced tumor burden and significantly prolonged animal survival (P < .0001) in AML xenograft models with negligible toxicity, accompanied by pharmacodynamic effects observed in vitro. Collectively, these findings argue that MLN4924 and belinostat interact synergistically by reciprocally disabling the DDR in AML/MDS cells. This strategy

  20. [Recent development of selective cyclooxygenase-2 inhibitors].

    Science.gov (United States)

    Kawai, Shinichi

    2002-12-01

    Nonsteroidal anti-inflammatory drugs(NSAIDs) are clinically effective against the inflammatory symptoms of rheumatoid arthritis. Recent attention has been focused on selective cyclooxygenase(COX)-2 inhibitors, a type of NSAID that inhibits a subtype of COX. Because of the different actions of COX-1 and COX-2, selective COX-2 inhibitors were expected to reduce adverse reactions such as gastrointestinal disorders. Various clinical studies have confirmed that the efficacy of COX-2 inhibitors for RA is similar to that of conventional NSAIDs, but they cause fewer severe gastrointestinal disorders. The incidence of complications related to renal dysfunction, such as edema and hypertension, is not different. Patients using selective COX-2 inhibitors have recently been reported to show an increase in thrombotic complications such as myocardial infarction. Therefore, more data on adverse events should be collected in the future from large-scale clinical studies to further clarify the actual value of selective COX-2 inhibitors. PMID:12510364

  1. The use of the tyrosine phosphatase antagonist orthovanadate in the study of a cell proliferation inhibitor

    Science.gov (United States)

    Enebo, D. J.; Hanek, G.; Fattaey, H. K.; Johnson, T. C.; Spooner, B. S. (Principal Investigator)

    1993-01-01

    Incubation of murine fibroblasts with orthovanadate, a global tyrosine phosphatase inhibitor, was shown to confer a "pseudo-transformed" phenotype with regard to cell morphology and growth characteristics. This alteration was manifested by both an increasing refractile appearance of the cells, consistent with many transformed cell lines, as well as an increase in maximum cell density was attained. Despite the abrogation of cellular tyrosine phosphatase activity, orthovanadate-treated cells remained sensitive to the biological activity of a naturally occurring sialoglycopeptide (SGP) cell surface proliferation inhibitor. The results indicated that tyrosine phosphatase activity, inhibited by orthovanadate, was not involved in the signal transduction pathway of the SGP.

  2. How sensitive are price sensitive events?

    OpenAIRE

    Duque, João; Pinto, Inês

    2004-01-01

    According to the Portuguese law and in line with the regulatory framework of the majority of the European capital markets (namely the UK market), security issuers have the obligation to reveal, in an appropriate way, publishable information, in order to avoid information asymmetry. This information is classified into two categories: the first called "Price Sensitive Events" and the second under the designation "Other Events/Communications" and, as it is expected, it does not necessarily influ...

  3. Are Psychopaths Morally Sensitive?

    Science.gov (United States)

    Maxwell, Bruce; Le Sage, Leonie

    2009-01-01

    Philosophical and psychological opinion is divided over whether moral sensitivity, understood as the ability to pick out a situation's morally salient features, necessarily involves emotional engagement. This paper seeks to offer insight into this question. It reasons that if moral sensitivity does draw significantly on affective capacities of…

  4. Multiple chemical sensitivity

    DEFF Research Database (Denmark)

    Tran, Marie Thi Dao; Arendt-Nielsen, Lars; Kupers, Ron;

    2013-01-01

    BACKGROUND: Multiple Chemical Sensitivity (MCS) is a chronic condition characterized by recurrent, non-specific symptoms in response to chemically unrelated exposures in non-toxic concentrations. Although the pathophysiology of MCS remains unknown, central sensitization may be an important factor...

  5. Allergic sensitization: screening methods

    DEFF Research Database (Denmark)

    Ladics, Gregory S.; Fry, Jeremy; Goodman, Richard;

    2014-01-01

    Experimental in silico, in vitro, and rodent models for screening and predicting protein sensitizing potential are discussed, including whether there is evidence of new sensitizations and allergies since the introduction of genetically modified crops in 1996, the importance of linear versus...

  6. Structure sensitivity in adsorption

    DEFF Research Database (Denmark)

    Hammer, Bjørk; Nielsen, Ole Holm; Nørskov, Jens Kehlet

    1997-01-01

    The structure sensitivity of CO adsorption on different flat, stepped, kinked and reconstructed Pt surfaces is studied using large-scale density-functional calculations. We find an extremely strong structure sensitivity in the adsorption energy with variations up to 1 eV (or 100%) from one...

  7. Differential sensitivity of rat voltage-sensitive sodium channel isoforms to pyrazoline-type insecticides.

    Science.gov (United States)

    Silver, Kristopher S; Soderlund, David M

    2006-07-15

    Pyrazoline-type insecticides are potent inhibitors of insect and mammalian voltage-sensitive sodium channels. In mammals, there are nine sodium channel alpha subunit isoforms that have unique distributions and pharmacological properties, but no published data exist that compare the relative sensitivity of these different mammalian sodium channel isoforms to inhibition by pyrazoline-type insecticides. This study employed the Xenopus oocyte expression system to examine the relative sensitivity of rat Na(v)1.2a, Na(v)1.4, Na(v)1.5, and Na(v)1.8 sodium channel alpha subunit isoforms to the pyrazoline-type insecticides indoxacarb, DCJW, and RH 3421. Additionally, we assessed the effect of coexpression with the rat beta1 auxiliary subunit on the sensitivity of the Na(v)1.2a and Na(v)1.4 isoforms to these compounds. The relative sensitivity of the four sodium channel alpha subunits differed for each of the three compounds we examined. With DCJW, the order of sensitivity was Na(v)1.4 > Na(v)1.2a > Na(v)1.5 > Na(v)1.8. In contrast, the relative sensitivity of these isoforms to indoxacarb differed from that to DCJW: the Na(v)1.8 isoform was most sensitive, the Na(v)1.4 isoform was completely insensitive, and the sensitivities of the Na(v)1.5 and Na(v)1.2a isoforms were intermediate between these two extremes. Moreover, the pattern of sensitivity to RH 3421 among these four isoforms was different from that for either indoxacarb or DCJW: the Na(v)1.4 isoform was most sensitive to RH 3421, whereas the sensitivities of the remaining three isoforms were substantially less than that of the Na(v)1.4 isoform and were approximately equivalent. The only statistically significant effect of coexpression of either the Na(v)1.2a or Na(v)1.4 isoforms with the beta1 subunit was the modest reduction in the sensitivity of the Na(v)1.2a isoform to RH 3421. These results demonstrate that mammalian sodium channel isoforms differ in their sensitivities to pyrazoline-type insecticides.

  8. Insulin sensitivity and albuminuria

    DEFF Research Database (Denmark)

    Pilz, Stefan; Rutters, Femke; Nijpels, Giel;

    2014-01-01

    OBJECTIVE: Accumulating evidence suggests an association between insulin sensitivity and albuminuria, which, even in the normal range, is a risk factor for cardiovascular diseases. We evaluated whether insulin sensitivity is associated with albuminuria in healthy subjects. RESEARCH DESIGN...... AND METHODS: We investigated 1,415 healthy, nondiabetic participants (mean age 43.9 ± 8.3 years; 54.3% women) from the RISC (Relationship between Insulin Sensitivity and Cardiovascular Disease) study, of whom 852 participated in a follow-up examination after 3 years. At baseline, insulin sensitivity...... was assessed by hyperinsulinemic-euglycemic clamps, expressed as the M/I value. Oral glucose tolerance test-based insulin sensitivity (OGIS), homeostasis model assessment of insulin resistance (HOMA-IR), and urinary albumin-to-creatinine ratio (UACR) were determined at baseline and follow-up. RESULTS...

  9. Finnish Teachers’ Ethical Sensitivity

    Directory of Open Access Journals (Sweden)

    Elina Kuusisto

    2012-01-01

    Full Text Available The study examined the ethical sensitivity of Finnish teachers (=864 using a 28-item Ethical Sensitivity Scale Questionnaire (ESSQ. The psychometric qualities of this instrument were analyzed, as were the differences in self-reported ethical sensitivity between practicing and student teachers and teachers of different subjects. The results showed that the psychometric qualities of the ESSQ were satisfactory and enabled the use of an explorative factor analysis. All Finnish teachers rated their level of ethical sensitivity as high, which indicates that they had internalized the ethical professionalism of teaching. However, practicing teachers’ assessments were higher than student teachers’. Moreover, science as a subject was associated with lower self-ratings of ethical sensitivity.

  10. Designing Inhibitors of Anthrax Toxin

    Science.gov (United States)

    Nestorovich, Ekaterina M.; Bezrukov, Sergey M.

    2014-01-01

    Introduction Present-day rational drug design approaches are based on exploiting unique features of the target biomolecules, small- or macromolecule drug candidates, and physical forces that govern their interactions. The 2013 Nobel Prize in chemistry awarded “for the development of multiscale models for complex chemical systems” once again demonstrated the importance of the tailored drug discovery that reduces the role of the trial and error approach to a minimum. The “rational drug design” term is rather comprehensive as it includes all contemporary methods of drug discovery where serendipity and screening are substituted by the information-guided search for new and existing compounds. Successful implementation of these innovative drug discovery approaches is inevitably preceded by learning the physics, chemistry, and physiology of functioning of biological structures under normal and pathological conditions. Areas covered This article provides an overview of the recent rational drug design approaches to discover inhibitors of anthrax toxin. Some of the examples include small-molecule and peptide-based post-exposure therapeutic agents as well as several polyvalent compounds. The review also directs the reader to the vast literature on the recognized advances and future possibilities in the field. Expert opinion Existing options to combat anthrax toxin lethality are limited. With the only anthrax toxin inhibiting therapy (PA-targeting with a monoclonal antibody, raxibacumab) approved to treat inhalational anthrax, in our view, the situation is still insecure. The FDA’s animal rule for drug approval, which clears compounds without validated efficacy studies on humans, creates a high level of uncertainty, especially when a well-characterized animal model does not exist. Besides, unlike PA, which is known to be unstable, LF remains active in cells and in animal tissues for days. Therefore, the effectiveness of the post-exposure treatment of the individuals

  11. Vascular calcification: Inducers and inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Donghyun, E-mail: dhlee@cau.ac.kr [Department of Biomedical Engineering, Division of Integrative Engineering, Chung-Ang University, 221 Heukseok-Dong, Dongjak-Gu, Seoul 156-756 (Korea, Republic of)

    2011-09-15

    Highlights: {center_dot} Types of vascular calcification processes. {center_dot} Inducers of vascular calcification. {center_dot} Inhibitors of vascular calcifications. {center_dot} Clinical utility for vascular calcification therapy. {center_dot} Implications for the development of new tissue engineering strategies. - Abstract: Unlike the traditional beliefs, there are mounting evidences suggesting that ectopic mineral depositions, including vascular calcification are mostly active processes, many times resembling that of the bone mineralization. Numbers of agents are involved in the differentiation of certain subpopulation of smooth muscle cells (SMCs) into the osteoblast-like entity, and the activation and initiation of extracellular matrix ossification process. On the other hand, there are factors as well, that prevent such differentiation and ectopic calcium phosphate formation. In normal physiological environments, activities of such procalcific and anticalcific regulatory factors are in harmony, prohibiting abnormal calcification from occurring. However, in certain pathophysiological conditions, such as atherosclerosis, chronic kidney disease (CKD), and diabetes, such balances are altered, resulting in abnormal ectopic mineral deposition. Understanding the factors that regulate the formation and inhibition of ectopic mineral formation would be beneficial in the development of tissue engineering strategies for prevention and/or treatment of such soft-tissue calcification. Current review focuses on the factors that seem to be clinically relevant and/or could be useful in developing future tissue regeneration strategies. Clinical utilities and implications of such factors are also discussed.

  12. ALK inhibitors, a pharmaceutical perspective

    Directory of Open Access Journals (Sweden)

    Arturo eGalvani

    2012-02-01

    Full Text Available In 2007, the ALK tyrosine kinase, already known to be translocated and activated in Anaplastic Large Cell Lymphoma, and a few other rare cancers, was described as a potential therapeutic target for a subset of non small-cell lung cancer (NSCLC patients. Clinical proof of concept, culminating in the recent approval by the FDA of the Pfizer drug Xalkori (crizotinib, formerly known as PF-02341066 followed in record time. The drug was approved together with a companion diagnostic, the Vysis ALK Break Apart FISH Probe Kit (Abbott Molecular, Inc. for detection of eligible patients. This remarkable example of the coming of age of personalized medicine in cancer therapy is hopefully only an auspice of things to come in this rapidly developing field. Perhaps unsurprisingly, however, the appearance of clinical acquired resistance to crizotinib has already been observed early on in clinical testing, with the identification of several ALK secondary point mutations which diminish drug efficacy, and which open the way for development of second-generation inhibitors. It is also emerging that acquired resistance to crizotinib may also occur through ALK-independent mechanisms, which still need to be elucidated in detail.

  13. VEGF Inhibitors for Cancer Therapy

    Directory of Open Access Journals (Sweden)

    Prakash S. Sukhramani

    2010-01-01

    Full Text Available Despite significant advances in systemic therapies, radiation oncology, and surgical techniques, many patients with cancer are still incurable. A novel therapeutic approach has been to target the vascular endothelial growth factors (VEGFs which are often mutated and/or over-expressed in many tumors. The ligands and receptors of VEGF family are well established as key regulators of angiogenesis and vasculogenesis processes. VEGF is a homodimeric, basic, 45 kDa glycoprotein specific for vascular endothelial cells. Specifically, VEGF participates in regulation of the female reproductive cycle, wound healing, inflammation, vascular permeability, vascular tone, hematopoiesis and also contributes to pathological angiogenesis disorders such as cancer, rheumatoid arthritis, diabetic retinopathy and the neovascular form of macular degeneration. Thus, the role of VEGF has been extensively studied in the pathogenesis and angiogenesis of human cancers. Clinical trials have anti-VEGF therapies are effective in reducing tumor size, metastasis and blood vessel formation. Clinically, this may result in increased progression free survival, overall patient survival rate and will expand the potential for combinatorial therapies. The aim of present review is on the cellular responses of VEGF inhibitors and their implications for cancer therapy.

  14. Antitumor activity of pimasertib, a selective MEK 1/2 inhibitor, in combination with PI3K/mTOR inhibitors or with multi-targeted kinase inhibitors in pimasertib-resistant human lung and colorectal cancer cells.

    Science.gov (United States)

    Martinelli, Erika; Troiani, Teresa; D'Aiuto, Elena; Morgillo, Floriana; Vitagliano, Donata; Capasso, Anna; Costantino, Sarah; Ciuffreda, Loreta Pia; Merolla, Francesco; Vecchione, Loredana; De Vriendt, Veerle; Tejpar, Sabine; Nappi, Anna; Sforza, Vincenzo; Martini, Giulia; Berrino, Liberato; De Palma, Raffaele; Ciardiello, Fortunato

    2013-11-01

    The RAS/RAF/MEK/MAPK and the PTEN/PI3K/AKT/mTOR pathways are key regulators of proliferation and survival in human cancer cells. Selective inhibitors of different transducer molecules in these pathways have been developed as molecular targeted anti-cancer therapies. The in vitro and in vivo anti-tumor activity of pimasertib, a selective MEK 1/2 inhibitor, alone or in combination with a PI3K inhibitor (PI3Ki), a mTOR inhibitor (everolimus), or with multi-targeted kinase inhibitors (sorafenib and regorafenib), that block also BRAF and CRAF, were tested in a panel of eight human lung and