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  1. Cancer stem cells and chemoradiation resistance

    International Nuclear Information System (INIS)

    Cancer is a disease of genetic and epigenetic alterations, which are emphasized as the central mechanisms of tumor progression in the multistepwise model. Discovery of rare subpopulations of cancer stem cells (CSCs) has created a new focus in cancer research. The heterogeneity of tumors can be explained with the help of CSCs supported by antiapoptotic signaling. CSCs mimic normal adult stem cells by demonstrating resistance to toxic injuries and chemoradiation therapy. Moreover, they might be responsible for tumor relapse following apparent beneficial treatments. Compared with hematopoietic malignancies, conventional therapy regimes in solid tumors have improved the overall survival marginally, illustrating the profound impact of treatment resistance. This implies that the present therapies, which follow total elimination of rapidly dividing and differentiated tumor cells, need to be modified to target CSCs that repopulate the tumor. In this review article, we report on recent findings regarding the involvement of CSCs in chemoradiation resistance and provide new insights into their therapeutic implications in cancer. (author)

  2. Overcoming Multidrug Resistance in Cancer Stem Cells

    Directory of Open Access Journals (Sweden)

    Karobi Moitra

    2015-01-01

    Full Text Available The principle mechanism of protection of stem cells is through the expression of ATP-binding cassette (ABC transporters. These transporters serve as the guardians of the stem cell population in the body. Unfortunately these very same ABC efflux pumps afford protection to cancer stem cells in tumors, shielding them from the adverse effects of chemotherapy. A number of strategies to circumvent the function of these transporters in cancer stem cells are currently under investigation. These strategies include the development of competitive and allosteric modulators, nanoparticle mediated delivery of inhibitors, targeted transcriptional regulation of ABC transporters, miRNA mediated inhibition, and targeting of signaling pathways that modulate ABC transporters. The role of ABC transporters in cancer stem cells will be explored in this paper and strategies aimed at overcoming drug resistance caused by these particular transporters will also be discussed.

  3. Mechanisms of Therapeutic Resistance in Cancer (Stem) Cells with Emphasis on Thyroid Cancer Cells

    OpenAIRE

    Hombach-Klonisch, Sabine; Natarajan, Suchitra; Thanasupawat, Thatchawan; Medapati, Manoj; PATHAK, ALOK; Ghavami, Saeid; Klonisch, Thomas

    2014-01-01

    The two main reasons for death of cancer patients, tumor recurrence and metastasis, are multi-stage cellular processes that involve increased cell plasticity and coincide with elevated resistance to anti-cancer treatments. Epithelial-to-mesenchymal transition (EMT) is a key contributor to metastasis in many cancer types, including thyroid cancer and is known to confer stem cell-like properties onto cancer cells. This review provides an overview of molecular mechanisms and factors known to con...

  4. Overexpression of kinesins mediates docetaxel resistance in breast cancer cells.

    Science.gov (United States)

    De, Sarmishtha; Cipriano, Rocky; Jackson, Mark W; Stark, George R

    2009-10-15

    Resistance to chemotherapy remains a major barrier to the successful treatment of cancer. To understand mechanisms underlying docetaxel resistance in breast cancer, we used an insertional mutagenesis strategy to identify proteins whose overexpression confers resistance. A strong promoter was inserted approximately randomly into the genomes of tumor-derived breast cancer cells, using a novel lentiviral vector. We isolated a docetaxel-resistant clone in which the level of the kinesin KIFC3 was elevated. When KIFC3 or the additional kinesins KIFC1, KIF1A, or KIF5A were overexpressed in the breast cancer cell lines MDA-MB231 and MDA-MB 468, the cells became more resistant to docetaxel. The binding of kinesins to microtubules opposes the stabilizing effect of docetaxel that prevents cytokinesis and leads to apoptosis. Our finding that kinesins can mediate docetaxel resistance might lead to novel therapeutic approaches in which kinesin inhibitors are paired with taxanes. PMID:19789344

  5. Troglitazone reverses the multiple drug resistance phenotype in cancer cells

    Directory of Open Access Journals (Sweden)

    Gerald F Davies

    2009-03-01

    Full Text Available Gerald F Davies1, Bernhard HJ Juurlink2, Troy AA Harkness11Department of Anatomy and Cell Biology, College of Medicine, University of Saskatchewan, Saskatoon, Canada; 2College of Medicine, Alfaisal University, Riyadh, Kingdom of Saudi ArabiaAbstract: A major problem in treating cancer is the development of drug resistance. We previously demonstrated doxorubicin (DOX resistance in K562 human leukemia cells that was associated with upregulation of glyoxalase 1 (GLO-1 and histone H3 expression. The thiazolidinedione troglitazone (TRG downregulated GLO-1 expression and further upregulated histone H3 expression and post-translational modifications in these cells, leading to a regained sensitivity to DOX. Given the pleiotropic effects of epigenetic changes in cancer development, we hypothesized that TRG may downregulate the multiple drug resistance (MDR phenotype in a variety of cancer cells. To test this, MCF7 human breast cancer cells and K562 cells were cultured in the presence of low-dose DOX to establish DOX-resistant cell lines (K562/DOX and MCF7/DOX. The MDR phenotype was confirmed by Western blot analysis of the 170 kDa P-glycoprotein (Pgp drug efflux pump multiple drug resistance protein 1 (MDR-1, and the breast cancer resistance protein (BCRP. TRG markedly decreased expression of both MDR-1 and BCRP in these cells, resulting in sensitivity to DOX. Silencing of MDR-1 expression also sensitized MCF7/DOX cells to DOX. Use of the specific and irreversible peroxisome proliferator-activated receptor gamma (PPARγ inhibitor GW9662 in the nanomolar range not only demonstrated that the action of TRG on MCF/DOX was PPARγ-independent, but indicated that PPARγ may play a role in the MDR phenotype, which is antagonized by TRG. We conclude that TRG is potentially a useful adjunct therapy in chemoresistant cancers. Keywords: chemotherapy, doxorubicin, breast cancer resistance protein-1, multiple drug resistance, multiple drug resistance protein 1

  6. Carboplatin treatment of antiestrogen-resistant breast cancer cells

    DEFF Research Database (Denmark)

    Larsen, Mathilde S; Yde, Christina Westmose; Christensen, Ib J;

    2012-01-01

    sensitivity to carboplatin, as it was previously shown with cisplatin, and whether low Bcl-2 expression levels have a potential value as marker for increased carboplatin sensitivity. Breast cancer cells resistant to the pure antiestrogen fulvestrant, and two out of four cell lines resistant to the...... antiestrogen tamoxifen, were more sensitive to carboplatin treatment compared to the parental MCF-7 cell line. This indicates that carboplatin may be an advantageous treatment in antiestrogen‑resistant breast cancer; however, a marker for increased sensitivity would be needed. Low Bcl-2 expression was...... combination with Bcl-xL and Bax, could explain the observed responses to carboplatin in all tamoxifen‑resistant cell lines, indicating that more markers are needed to predict the response to carboplatin in tamoxifen‑resistant breast cancer....

  7. Phorbol esters induce multidrug resistance in human breast cancer cells

    International Nuclear Information System (INIS)

    Mechanisms responsible for broad-based resistance to antitumor drugs derived from natural products (multidrug resistance) are incompletely understood. Agents known to reverse the multidrug-resistant phenotype (verapamil and trifluoperazine) can also inhibit the activity of protein kinase C. When the authors assayed human breast cancer cell lines for protein kinase C activity, they found that enzyme activity was 7-fold higher in the multidrug-resistance cancer cells compared with the control, sensitive parent cells. Exposure of drug-sensitive cells to the phorbol ester phorbol 12,13-dibutyate [P(BtO)2] led to an increase in protein kinase C activity and induced a drug-resistance phenotype, whereas exposure of drug-resistant cells to P(BtO)2 further increased drug resistance. In sensitive cells, this increased resistance was accomplished by a 3.5-fold increased phosphorylation of a 20-kDa particulate protein and a 35-40% decreased intracellular accumulation of doxorubicin and vincristine. P(BtO)2 induced resistance to agents involved in the multidrug-resistant phenotype (doxorubicin and vincristine) but did not affect sensitivity to an unrelated alkylating agent (melphalan). The increased resistance was partially or fully reversible by the calcium channel blocker verapamil and by the calmodulin-antagonist trifluoperazine. These data suggest that stimulation of protein kinase C playus a role in the drug-transport changes in multidrug-resistant cells. This may occur through modulation of an efflux pump by protein phosphorylation

  8. Overcome Cancer Cell Drug Resistance Using Natural Products

    Directory of Open Access Journals (Sweden)

    Pu Wang

    2015-01-01

    Full Text Available Chemotherapy is one of the major treatment methods for cancer. However, failure in chemotherapy is not uncommon, mainly due to dose-limiting toxicity associated with drug resistance. Management of drug resistance is important towards successful chemotherapy. There are many reports in the Chinese literature that natural products can overcome cancer cell drug resistance, which deserve sharing with scientific and industrial communities. We summarized the reports into four categories: (1 in vitro studies using cell line models; (2 serum pharmacology; (3 in vivo studies using animal models; and (4 clinical studies. Fourteen single compounds were reported to have antidrug resistance activity for the first time. In vitro, compounds were able to overcome drug resistance at nontoxic or subtoxic concentrations, in a dose-dependent manner, by inhibiting drug transporters, cell detoxification capacity, or cell apoptosis sensitivity. Studies in vivo showed that single compounds, herbal extract, and formulas had potent antidrug resistance activities. Importantly, many single compounds, herbal extracts, and formulas have been used clinically to treat various diseases including cancer. The review provides comprehensive data on use of natural compounds to overcome cancer cell drug resistance in China, which may facilitate the therapeutic development of natural products for clinical management of cancer drug resistance.

  9. Cancer stem cells and resistance to chemo and radio therapy.

    Science.gov (United States)

    Malik, Babar; Nie, Daotai

    2012-01-01

    Cancer stem cells (CSCs, or tumor initiating cells) are responsible for tumor initiation. If cancer treatment kills most of cancer cells in the stage of transit amplifying and differentiation without killing the stem cells, the surviving CSCs will eventually lead to recurrence of tumors. Studies have suggested that CSCs may be the primary mediators of resistance to chemo- and radio-therapy, leading to failure in cancer therapy. Numerous targets are being investigated for their potential involvement in the self-renewal and chemo- and radio-resistance of cancer cells. However, despite the intensive efforts invested into characterizing the role of cancer stem cells, there is a sense of uncertainty regarding the identity and number of these cells as well as the implications in cancer treatment. In this review, we will discuss the identification of CSCs by cell surface markers, the biology of CSCs, and the role of CSCs in resistance to radio- and chemo-therapy. This review will discuss the advances in targeting CSCs to improve the efficacy of chemo- and radio-therapy. PMID:22202026

  10. Tamoxifen-resistant breast cancer cells possess cancer stem-like cell properties

    Institute of Scientific and Technical Information of China (English)

    LIU Hui; ZHANG Heng-wei; SUN Xian-fu; GUO Xu-hui; HE Ya-ning; CUI Shu-de; FAN Qing-xia

    2013-01-01

    Background Cancer stem cells (CSCs) are the cause of cancer recurrence because they are resistant to conventional therapy and contribute to cancer growth and metastasis.Endocrinotherapy is the most common breast cancer therapy and acquired tamoxifen (TAM) resistance is the main reason for endocrinotherapy failure during such therapy.Although acquired resistance to endocrine treatment has been extensively studied,the underlying mechanisms are unclear.We hypothesized that breast CSCs played an important role in TAM-induced resistance during breast cancer therapy.Therefore,we investigated the biological characteristics of TAM-resistant (TAM-R) breast cancer cells.Methods Mammosphere formation and tumorigenicity of wild-type (WT) and TAM-R MCF7 cells were tested by a mammosphere assay and mouse tumor xenografts respectively.Stem-cell markers (SOX-2,OCT-4,and CD133) and epithelial-mesenchymal transition (EMT) markers were tested by quantitative real-time (qRT)-PCR.Morphological observation was performed to characterize EMT.Results After induction of TAM resistance,TAM-R MCF7 cells exhibited increased proliferation in the presence of TAM compared to that of WT MCF7 cells (P <0.05),indicating enhanced TAM resistance of TAM-R MCF7 cells compared to that of WT MCF7 cells.TAM-R MCF7 cells showed enhanced mammosphere formation and tumorigenicity in nude mice compared to that of WT MCF7 cells (P <0.01),demonstrating the elevated CSC properties of TAM-R MCF7 cells.Consistently,qRT-PCR revealed that TAM-R MCF7 cells expressed increased mRNA levels of stem cell markers including SOX-2,OCT-4,and CD133,compared to those of WT MCF7 cells (P <0.05).Morphologically,TAM-R MCF7 cells showed a fibroblastic phenotype,but WT MCF7 cells were epithelial-like.After induction of TAM resistance,qRT-PCR indicated that MCF7 cells expressed increased mRNA levels of Snail,vimentin,and N-cadherin and decreased levels of E-cadherin,which are considered as EMT characteristics (P <0

  11. DNA Methylation and Apoptosis Resistance in Cancer Cells

    OpenAIRE

    Pierre-François Cartron; François Marie Vallette; Eric Hervouet; Mathilde Cheray

    2013-01-01

    Apoptosis is a cell death programme primordial to cellular homeostasis efficiency. This normal cell suicide program is the result of the activation of a cascade of events in response to death stimuli. Apoptosis occurs in normal cells to maintain a balance between cell proliferation and cell death. A deregulation of this balance due to modifications in the apoptosic pathway leads to different human diseases including cancers. Apoptosis resistance is one of the most important hallmarks of cance...

  12. Nanodrug Delivery in Reversing Multidrug Resistance in Cancer Cells

    Directory of Open Access Journals (Sweden)

    Sonali eKapse-Mistry

    2014-07-01

    Full Text Available Different mechanisms in cancer cells become resistant to one or more chemotherapeutics is known as multidrug resistance(MDR which hinders chemotherapy efficacy. Potential factors for MDR includes enhanced drug detoxification, decreased drug uptake, increased intracellular nucleophiles levels, enhanced repair of drug induced DNA damage, overexpression of drug transporter such as P-glycoprotein(P-gp, multidrug resistance-associated proteins(MRP1, MRP2 and breast cancer resistance protein(BCRP. Currently nanoassemblies such as polymeric/solid lipid/inorganic/metal nanoparticles, quantum dots, dendrimers, liposomes, micelles has emerged as an innovative, effective and promising platforms for treatment of drug resistant cancer cells. Nanocarriers have potential to improve drug therapeutic index, ability for multifunctionality, divert ABC-transporter mediated drug efflux mechanism and selective targeting to tumor cells, cancer stem cells, tumor initiating cells or cancer microenvironment. Selective nanocarrier targeting to tumor overcomes dose-limiting side effects, lack of selectivity, tissue toxicity, limited drug access to tumor tissues, high drug doses and emergence of multiple drug resistance with conventional or combination chemotherapy. Current review highlights various nanodrug delivery systems to overcome mechanism of MDR by neutralizing, evading or exploiting the drug efflux pumps and those independent of drug efflux pump mechanism by silencing Bcl-2 and HIF1 gene expressions by siRNA and miRNA, modulating ceramide levels and targeting NF-B. Theragnostics combining a cytotoxic agent, targeting moiety, chemosensitizing agent and diagnostic imaging aid are highlighted as effective and innovative systems for tumor localization and overcoming MDR. Physical approaches such as combination of drug with thermal/ultrasound/photodynamic therapies to overcome MDR are focused. The review focuses on newer drug delivery systems developed to overcome

  13. Breast cancer cells with acquired antiestrogen resistance are sensitized to cisplatin-induced cell death

    DEFF Research Database (Denmark)

    Yde, Christina Westmose; Gyrd-Hansen, Mads; Lykkesfeldt, Anne E; Issinger, Olaf-Georg; Stenvang, Jan

    2007-01-01

    future breast cancer treatment. In this study, we have investigated the effect of the chemotherapeutic compound cisplatin using a panel of antiestrogen-resistant breast cancer cell lines established from the human breast cancer cell line MCF-7. We show that the antiestrogen-resistant cells are...... parental MCF-7 cells. Our data show that Bcl-2 can protect antiestrogen-resistant breast cancer cells from cisplatin-induced cell death, indicating that the reduced expression of Bcl-2 in the antiestrogen-resistant cells plays a role in sensitizing the cells to cisplatin treatment.......Antiestrogens are currently used for treating breast cancer patients who have estrogen receptor-positive tumors. However, patients with advanced disease will eventually develop resistance to the drugs. Therefore, compounds effective on antiestrogen-resistant tumors will be of great importance for...

  14. Overcoming cisplatin resistance of ovarian cancer cells by targeting HIF-1-regulated cancer metabolism.

    Science.gov (United States)

    Ai, Zhihong; Lu, Yang; Qiu, Songbo; Fan, Zhen

    2016-04-01

    Cisplatin is currently one of the most effective chemotherapeutic drugs used for treating ovarian cancer; however, resistance to cisplatin is common. In this study, we explored an experimental strategy for overcoming cisplatin resistance of human ovarian cancer from the new perspective of cancer cell metabolism. By using two pairs of genetically matched cisplatin-sensitive and cisplatin-resistant ovarian cancer cell lines, we tested the hypothesis that downregulating hypoxia-inducible factor-1 (HIF-1), which regulates metabolic enzymes involved in glycolysis, is a promising strategy for overcoming cisplatin resistance of human ovarian cancer cells. We found that cisplatin downregulated the level of the regulatable α subunit of HIF-1, HIF-1α, in cisplatin-sensitive ovarian cancer cells through enhancing HIF-1α degradation but did not downregulate HIF-1α in their cisplatin-resistant counterparts. Overexpression of a degradation-resistant HIF-1α (HIF-1α ΔODD) reduced cisplatin-induced apoptosis in cisplatin-sensitive cells, whereas genetic knockdown of HIF-1α or pharmacological promotion of HIF-1α degradation enhanced response to cisplatin in both cisplatin-sensitive and cisplatin-resistant ovarian cancer cells. We further demonstrated that knockdown of HIF-1α improved the response of cisplatin-resistant ovarian cancer cells to cisplatin by redirecting the aerobic glycolysis in the resistant cancer cells toward mitochondrial oxidative phosphorylation, leading to cell death through overproduction of reactive oxygen species. Our findings suggest that the HIF-1α-regulated cancer metabolism pathway could be a novel target for overcoming cisplatin resistance in ovarian cancer. PMID:26801746

  15. Slow-Cycling Therapy-Resistant Cancer Cells

    OpenAIRE

    Moore, Nathan; Houghton, JeanMarie; Lyle, Stephen

    2011-01-01

    Tumor recurrence after chemotherapy is a major cause of patient morbidity and mortality. Recurrences are thought to be secondary to small subsets of cancer cells that are better able to survive traditional forms of chemotherapy and thus drive tumor regrowth. The ability to isolate and better characterize these therapy-resistant cells is critical for the future development of targeted therapies aimed at achieving more robust and long-lasting responses. Using a novel application for the prolife...

  16. Characterisation and Manipulation of Docetaxel Resistant Prostate Cancer Cell Lines

    LENUS (Irish Health Repository)

    O'Neill, Amanda J

    2011-10-07

    Abstract Background There is no effective treatment strategy for advanced castration-resistant prostate cancer. Although Docetaxel (Taxotere®) represents the most active chemotherapeutic agent it only gives a modest survival advantage with most patients eventually progressing because of inherent or acquired drug resistance. The aims of this study were to further investigate the mechanisms of resistance to Docetaxel. Three Docetaxel resistant sub-lines were generated and confirmed to be resistant to the apoptotic and anti-proliferative effects of increasing concentrations of Docetaxel. Results The resistant DU-145 R and 22RV1 R had expression of P-glycoprotein and its inhibition with Elacridar partially and totally reversed the resistant phenotype in the two cell lines respectively, which was not seen in the PC-3 resistant sublines. Resistance was also not mediated in the PC-3 cells by cellular senescence or autophagy but multiple changes in pro- and anti-apoptotic genes and proteins were demonstrated. Even though there were lower basal levels of NF-κB activity in the PC-3 D12 cells compared to the Parental PC-3, docetaxel induced higher NF-κB activity and IκB phosphorylation at 3 and 6 hours with only minor changes in the DU-145 cells. Inhibition of NF-κB with the BAY 11-7082 inhibitor reversed the resistance to Docetaxel. Conclusion This study confirms that multiple mechanisms contribute to Docetaxel resistance and the central transcription factor NF-κB plays an immensely important role in determining docetaxel-resistance which may represent an appropriate therapeutic target.

  17. Colorectal cancer stem cells : regulation of the phenotype and implications for therapy resistance

    OpenAIRE

    Emmink, B.L.

    2014-01-01

    In this thesis different aspects of cancer stem cells in colorectal cancer are discribed. We focus on the therapy resistance of cancer stem cells and the effect that reactive oxygen species and hypoxia have on the cancer stem cell phenotype. For this purpose a novel culture method to propagate cancer stem cells form resected tumor specimens was used.

  18. Phytosphingosine can overcome resistance to ionizing radiation in ionizing radiation-resistant cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Park, Moon Taek; Choi, Jung A; Kim, Min Jeong; Bae, Sang Woo; Kang, Chang Mo; Cho, Chul Koo; Lee, Yun Sil; Lee, Su Jae [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Kang, Seong Man [Graduate School of Biotechnology, Korea University, Seoul (Korea, Republic of); Chung, Hee Yong [College of Medicine, Hanyang University, Seoul (Korea, Republic of)

    2004-07-01

    Although the majority of cancer cells are killed by inonizing radiation, certain types show resistance to it. We previously reported that phytosphingosine also induces apoptotic cell death in caspase dependent pathway in human cancer cells. In the present study, we examined whether phytosphingosine could overcome radiation resistance in the variant Jurkat clones. We first selected radiation-resistant Jurkat clones and examined cross-responsiveness of the clones between radiation and phytosphingosine. Treatment with phytosphingosine significantly did not affect apoptosis in all the clones, indicating that there seemed to be cross-resistance between radiation and phytosphingosine. Nevertheless, combined treatment of phytosphingosine with radiation synergistically enhanced killing of radiation-resistant cells, compared to radiation or phytosphingosine alone. The pan-caspase inhibitor z-VAD-fmk did not completely inhibit the synergistic cell killing induced by combined treatment of ionizing radiation and phytosphingosine. These results demonstrated that apoptosis induced by combined treatment of radiation and phytosphingosine in radiation-resistant cells was associated with caspase independent pathway. We also found that apoptotic cell death induced by combined treatment of ionizing radiation and phytosphingosine correlated to the increases of ROS. The enhancement of ROS generation induced the loss of mitochondria transmembrane potential. In conclusion, ROS generation in combined treatment of phytosphingosine with radiation significantly induced the translocation of AIF to nucleus from mitochondria, suggesting a potential clinical application of combination treatment of radiation and phytosphingosine to radiation-resistant cancer cells.

  19. Drug Resistance and Cancer Stem Cells

    OpenAIRE

    Fonseca, João Pedro Couto

    2012-01-01

    O cancro do pulmão é a principal causa de morte por cancro a nível mundial. Apesar do crescente conhecimento sobre os mecanismos subjacentes ao processo tumorigénico não se tem observado alteração significativa na sobrevivência dos pacientes. É, por isso, urgente encontrar novas estratégias terapêuticas que visem superar a resistência, tanto intrínseca como extrínseca, observada com a quimioterapia corrente. Os tumores são caracterizados pela sua heterogeneidade celular, devido à coexistên...

  20. Properties of resistant cells generated from lung cancer cell lines treated with EGFR inhibitors

    International Nuclear Information System (INIS)

    Epidermal growth factor receptor (EGFR) signaling plays an important role in non-small cell lung cancer (NSCLC) and therapeutics targeted against EGFR have been effective in treating a subset of patients bearing somatic EFGR mutations. However, the cancer eventually progresses during treatment with EGFR inhibitors, even in the patients who respond to these drugs initially. Recent studies have identified that the acquisition of resistance in approximately 50% of cases is due to generation of a secondary mutation (T790M) in the EGFR kinase domain. In about 20% of the cases, resistance is associated with the amplification of MET kinase. In the remaining 30-40% of the cases, the mechanism underpinning the therapeutic resistance is unknown. An erlotinib resistant subline (H1650-ER1) was generated upon continuous exposure of NSCLC cell line NCI-H1650 to erlotinib. Cancer stem cell like traits including expression of stem cell markers, enhanced ability to self-renew and differentiate, and increased tumorigenicity in vitro were assessed in erlotinib resistant H1650-ER1 cells. The erlotinib resistant subline contained a population of cells with properties similar to cancer stem cells. These cells were found to be less sensitive towards erlotinib treatment as measured by cell proliferation and generation of tumor spheres in the presence of erlotinib. Our findings suggest that in cases of NSCLC accompanied by mutant EGFR, treatment targeting inhibition of EGFR kinase activity in differentiated cancer cells may generate a population of cancer cells with stem cell properties

  1. Sphingosine enhances apoptosis of radiation-resistant prostate cancer cells.

    Science.gov (United States)

    Nava, V E; Cuvillier, O; Edsall, L C; Kimura, K; Milstien, S; Gelmann, E P; Spiegel, S

    2000-08-15

    Ceramide has been implicated as an important component of radiation-induced apoptosis of human prostate cancer cells. We examined the role of the sphingolipid metabolites--ceramide, sphingosine, and sphingosine-1-phosphate--in susceptibility to radiation-induced apoptosis in prostate cancer cell lines with different sensitivities to gamma-irradiation. Exposure of radiation-sensitive TSU-Pr1 cells to 8-Gy irradiation led to a sustained increase in ceramide, beginning after 12 h of treatment and increasing to 2.5- to 3-fold within 48 h. Moreover, irradiation of TSU-Pr1 cells also produced a marked and rapid 50% decrease in the activity of sphingosine kinase, the enzyme that phosphorylates sphingosine to form sphingosine-1-phosphate. In contrast, the radiation-insensitive cell line, LNCaP, had sustained sphingosine kinase activity and did not produce elevated ceramide levels on 8-Gy irradiation. Although LNCaP cells are highly resistant to gamma-irradiation-induced apoptosis, they are sensitive to the death-inducing effects of tumor necrosis factor alpha, which also increases ceramide levels in these cells (K. Kimura et al., Cancer Res., 59: 1606-1614, 1999). Moreover, we found that although irradiation alone did not increase sphingosine levels in LNCaP cells, tumor necrosis factor alpha plus irradiation induced significantly higher sphingosine levels and markedly reduced intracellular levels of sphingosine-1-phosphate. The elevation of sphingosine levels either by exogenous sphingosine or by treatment with the sphingosine kinase inhibitor N,N-dimethylsphingosine induced apoptosis and also sensitized LNCaP cells to gamma-irradiation-induced apoptosis. Our data suggest that the relative levels of sphingolipid metabolites may play a role in determining the radiosensitivity of prostate cancer cells, and that the enhancement of ceramide and sphingosine generation could be of therapeutic value. PMID:10969794

  2. Wound Healing and Cancer Stem Cells: Inflammation as a Driver of Treatment Resistance in Breast Cancer

    OpenAIRE

    Arnold, Kimberly M; Opdenaker, Lynn M.; Daniel Flynn; Jennifer Sims-Mourtada

    2015-01-01

    The relationship between wound healing and cancer has long been recognized. The mechanisms that regulate wound healing have been shown to promote transformation and growth of malignant cells. In addition, chronic inflammation has been associated with malignant transformation in many tissues. Recently, pathways involved in inflammation and wound healing have been reported to enhance cancer stem cell (CSC) populations. These cells, which are highly resistant to current treatments, are capable o...

  3. Liver Label Retaining Cancer Cells Are Relatively Resistant to the Reported Anti-Cancer Stem Cell Drug Metformin

    OpenAIRE

    Xin, Hong-Wu; Ambe, Chenwi M.; Miller, Tyler C.; Chen, Jin-Qiu; Wiegand, Gordon W.; Anderson, Andrew J.; Ray, Satyajit; Mullinax, John E.; Hari, Danielle M; Koizumi, Tomotake; Godbout, Jessica D.; Goldsmith, Paul K.; Stojadinovic, Alexander; Rudloff, Udo; Thorgeirsson, Snorri S.

    2016-01-01

    Background & Aims: Recently, we reported that liver Label Retaining Cancer Cells (LRCC) can initiate tumors with only 10 cells and are relatively resistant to the targeted drug Sorafenib, a standard of practice in advanced hepatocellular carcinoma (HCC). LRCC are the only cancer stem cells (CSC) isolated alive according to a stem cell fundamental function, asymmetric cell division. Metformin has been reported to preferentially target many other types of CSC of different organs, including live...

  4. Tcf3 and cell cycle factors contribute to butyrate resistance in colorectal cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Chiaro, Christopher, E-mail: cchiaro@tcmedc.org [Department of Basic Sciences, The Commonwealth Medical College, 525 Pine Street, Scranton, PA 18509 (United States); Lazarova, Darina L., E-mail: dlazarova@tcmedc.org [Department of Basic Sciences, The Commonwealth Medical College, 525 Pine Street, Scranton, PA 18509 (United States); Bordonaro, Michael, E-mail: mbordonaro@tcmedc.org [Department of Basic Sciences, The Commonwealth Medical College, 525 Pine Street, Scranton, PA 18509 (United States)

    2012-11-09

    Highlights: Black-Right-Pointing-Pointer We investigate mechanisms responsible for butyrate resistance in colon cancer cells. Black-Right-Pointing-Pointer Tcf3 modulates butyrate's effects on Wnt activity and cell growth in resistant cells. Black-Right-Pointing-Pointer Tcf3 modulation of butyrate's effects differ by cell context. Black-Right-Pointing-Pointer Cell cycle factors are overexpressed in the resistant cells. Black-Right-Pointing-Pointer Reversal of altered gene expression can enhance the anti-cancer effects of butyrate. -- Abstract: Butyrate, a fermentation product of dietary fiber, inhibits clonal growth in colorectal cancer (CRC) cells dependent upon the fold induction of Wnt activity. We have developed a CRC cell line (HCT-R) that, unlike its parental cell line, HCT-116, does not respond to butyrate exposure with hyperactivation of Wnt signaling and suppressed clonal growth. PCR array analyses revealed Wnt pathway-related genes, the expression of which differs between butyrate-sensitive HCT-116 CRC cells and their butyrate-resistant HCT-R cell counterparts. We identified overexpression of Tcf3 as being partially responsible for the butyrate-resistant phenotype, as this DNA-binding protein suppresses the hyperinduction of Wnt activity by butyrate. Consequently, Tcf3 knockdown in HCT-R cells restores their sensitivity to the effects of butyrate on Wnt activity and clonal cell growth. Interestingly, the effects of overexpressed Tcf3 differ between HCT-116 and HCT-R cells; thus, in HCT-116 cells Tcf3 suppresses proliferation without rendering the cells resistant to butyrate. In HCT-R cells, however, the overexpression of Tcf3 inhibits Wnt activity, and the cells are still able to proliferate due to the higher expression levels of cell cycle factors, particularly those driving the G{sub 1} to S transition. Knowledge of the molecular mechanisms determining the variable sensitivity of CRC cells to butyrate may assist in developing approaches that

  5. Tcf3 and cell cycle factors contribute to butyrate resistance in colorectal cancer cells

    International Nuclear Information System (INIS)

    Highlights: ► We investigate mechanisms responsible for butyrate resistance in colon cancer cells. ► Tcf3 modulates butyrate’s effects on Wnt activity and cell growth in resistant cells. ► Tcf3 modulation of butyrate’s effects differ by cell context. ► Cell cycle factors are overexpressed in the resistant cells. ► Reversal of altered gene expression can enhance the anti-cancer effects of butyrate. -- Abstract: Butyrate, a fermentation product of dietary fiber, inhibits clonal growth in colorectal cancer (CRC) cells dependent upon the fold induction of Wnt activity. We have developed a CRC cell line (HCT-R) that, unlike its parental cell line, HCT-116, does not respond to butyrate exposure with hyperactivation of Wnt signaling and suppressed clonal growth. PCR array analyses revealed Wnt pathway-related genes, the expression of which differs between butyrate-sensitive HCT-116 CRC cells and their butyrate-resistant HCT-R cell counterparts. We identified overexpression of Tcf3 as being partially responsible for the butyrate-resistant phenotype, as this DNA-binding protein suppresses the hyperinduction of Wnt activity by butyrate. Consequently, Tcf3 knockdown in HCT-R cells restores their sensitivity to the effects of butyrate on Wnt activity and clonal cell growth. Interestingly, the effects of overexpressed Tcf3 differ between HCT-116 and HCT-R cells; thus, in HCT-116 cells Tcf3 suppresses proliferation without rendering the cells resistant to butyrate. In HCT-R cells, however, the overexpression of Tcf3 inhibits Wnt activity, and the cells are still able to proliferate due to the higher expression levels of cell cycle factors, particularly those driving the G1 to S transition. Knowledge of the molecular mechanisms determining the variable sensitivity of CRC cells to butyrate may assist in developing approaches that prevent or reverse butyrate resistance.

  6. 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...

  7. Mechanism of multidrug resistance of human small cell lung cancer cell line H446/VP

    Institute of Scientific and Technical Information of China (English)

    WANG Yan-ling; YAN Yun-li; ZHOU Na-jing; HAN Shuo; ZHAO Jun-xia; CAO Cui-li; Lü Yu-hong

    2010-01-01

    Background Small cell lung cancer (SCLC) is the most aggressive form of lung cancer. This study aimed to investigate the mechanism of human small cell lung cancer cell line resistance to etoposide (VP-16), H446/VP.Methods The cell viability was measured by M∏ assay. Immunocytochemistry, reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting methods were used to detect the multidrug resistance gene (MDR1), bcl-2, bax and the topoisomerase Ⅱ (Topo Ⅱ) expressions in H446 and H446/VP cells after treated with or without VP-16.Results The 50% inhibition concentration (IC50) of VP-16 on H446 cells was 49 mg/L, and 836 mg/L was for H446/VP cells. The expressions of MDR1 and bcl-2 were up-regulated, while the amounts of bax and Topo Ⅱ were reduced in H446/VP cells. After treated with 49 mg/L of VP-16, it showed that the drug could significantly inhibit bcl-2 and Topo Ⅱ expressions, and increase bax expression in H446 cells compared with that of H446/VP cells.Conclusions The H446/VP cell was stably resistant to VP-16. The decreased expression of Topo Ⅱ was correlated with the H446/VP multidrug resistance. The elevated expressions of MDR1, and the altered apoptotic pathways also played an important role in VP-16 induced multidrug resistance of SCLC.

  8. Microbeam PIXE analysis of platinum resistant and sensitive ovarian cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Jeynes, J.C.G., E-mail: J.C.Jeynes@surrey.ac.u [Ion Beam Centre, University of Surrey, Guildford GU2 7XH (United Kingdom); Bailey, M.J. [Ion Beam Centre, University of Surrey, Guildford GU2 7XH (United Kingdom); Coley, H. [Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7XH (United Kingdom); Kirkby, K.J.; Jeynes, C. [Ion Beam Centre, University of Surrey, Guildford GU2 7XH (United Kingdom)

    2010-06-15

    Microbeam PIXE was used to analyse platinum in single ovarian cancer cells. Carboplatin sensitive and resistant cells were grown as a monolayer on polypropylene and treated with either carboplatin or cisplatin. Pt from the carboplatin could not be detected. The Pt from cisplatin in the cells could be detected, and significantly more Zn was found in the resistant cells compared to the sensitive cells. The sensitive cells probably accumulated more cisplatin than the resistant ones.

  9. Breast cancers radiation-resistance: key role of the cancer stem cells marker CD24

    International Nuclear Information System (INIS)

    This work focuses on the characterization of radiation-resistant breast cancer cells, responsible for relapse after radiotherapy. The 'Cancer Stem Cells' (CSC) theory describes a radiation-resistant cellular sub-population, with enhanced capacity to induce tumors and proliferate. In this work, we show that only the CSC marker CD24-/low defines a radiation resistant cell population, able to transmit the 'memory' of irradiation, expressed as long term genomic instability in the progeny of irradiated cells. We show that CD24 is not only a marker, but is an actor of radiation-response. So, CD24 expression controls cell proliferation in vitro and in vivo, and ROS level before and after irradiation. As a result, CD24-/low cells display enhanced radiation-resistance and genomic stability. For the first time, our results attribute a role to CD24-/low CSCs in the transmission of genomic instability. Moreover, by providing informations on tumor intrinsic radiation-sensitivity, CD24- marker could help to design new radiotherapy protocols. (author)

  10. Reduced expression of p27 is a novel mechanism of docetaxel resistance in breast cancer cells

    International Nuclear Information System (INIS)

    Docetaxel is one of the most effective chemotherapeutic agents in the treatment of breast cancer. Breast cancers can have an inherent or acquired resistance to docetaxel but the causes of this resistance remain unclear. However, apoptosis and cell cycle regulation are key mechanisms by which most chemotherapeutic agents exert their cytotoxic effects. We created two docetaxel-resistant human breast cancer cell lines (MCF-7 and MDA-MB-231) and performed cDNA microarray analysis to identify candidate genes associated with docetaxel resistance. Gene expression changes were validated at the RNA and protein levels by reverse transcription PCR and western analysis, respectively. Gene expression cDNA microarray analysis demonstrated reduced p27 expression in docetaxel-resistant breast cancer cells. Although p27 mRNA expression was found to be reduced only in MCF-7 docetaxel-resistant sublines (2.47-fold), reduced expression of p27 protein was noted in both MCF-7 and MDA-MB-231 docetaxel-resistant breast cancer cells (2.83-fold and 3.80-fold, respectively). This study demonstrates that reduced expression of p27 is associated with acquired resistance to docetaxel in breast cancer cells. An understanding of the genes that are involved in resistance to chemotherapy may allow further development in modulating drug resistance, and may permit selection of those patients who are most likely to benefit from such therapies

  11. MicroRNA-320a promotes 5-FU resistance in human pancreatic cancer cells

    OpenAIRE

    Weibin Wang; Lijun Zhao; Xueju Wei; Lanlan Wang; Siqi Liu; Yu Yang; Fang Wang; Guotao Sun; Junwu Zhang; Yanni Ma; Yupei Zhao; Jia Yu

    2016-01-01

    The drug-resistance of pancreatic cancer cells results in poor therapeutic effect. To predict the therapeutic effect of the chemotherapy drugs to specific patients and to reverse the resistance of pancreatic cancer cells are critical for chemotherapy of pancreatic cancer. MicroRNAs (miRNAs) have been reported to play important roles in the genesis of drug-resistance of various cancer types. There are also many advantages of miRNAs in diagnosis and therapy of disease. Although several miRNAs r...

  12. Triclosan Potentiates Epithelial-To-Mesenchymal Transition in Anoikis-Resistant Human Lung Cancer Cells

    OpenAIRE

    Winitthana, Thidarat; Lawanprasert, Somsong; Chanvorachote, Pithi

    2014-01-01

    Alteration of cancer cell toward mesenchymal phenotype has been shown to potentiate tumor aggressiveness by increasing cancer cell metastasis. Herein, we report the effect of triclosan, a widely used antibacterial agent found in many daily products, in enhancing the epithelial-to-mesenchymal transition (EMT) in aggressive anoikis resistant human H460 lung cancer cells. EMT has been long known to increase abilities of the cells to increase migration, invasion, and survival in circulating syste...

  13. Self-assembled micelles of amphiphilic PEGylated rapamycin for loading paclitaxel and resisting multidrug resistance cancer cells

    OpenAIRE

    W. Tian; Liu, J; Guo, Y; Shen, Y.; D. Zhou; Guo, S.

    2015-01-01

    Self-assembled micelles of amphiphilic PEG–rapamycin conjugates loaded with paclitaxel have been developed for co-delivery and simultaneous intracellular release of paclitaxel and rapamycin, bypassing the cancer cell drug resistant mechanism and maximising the synergy of dual-drug combinational therapy. This novel nanomedicine offers 20-fold improved potency over free paclitaxel against a model multidrug resistant human breast cancer cell.

  14. Cancer stem cells and cisplatin-resistant cells isolated from non-small-lung cancer cell lines constitute related cell populations

    Science.gov (United States)

    Lopez-Ayllon, Blanca D; Moncho-Amor, Veronica; Abarrategi, Ander; de Cáceres, Inmaculada Ibañez; Castro-Carpeño, Javier; Belda-Iniesta, Cristobal; Perona, Rosario; Sastre, Leandro

    2014-01-01

    Lung cancer is the top cause of cancer-related deceases. One of the reasons is the development of resistance to the chemotherapy treatment. In particular, cancer stem cells (CSCs), can escape treatment and regenerate the bulk of the tumor. In this article, we describe a comparison between cancer cells resistant to cisplatin and CSCs, both derived from the non-small-cell lung cancer cell lines H460 and A549. Cisplatin-resistant cells were obtained after a single treatment with the drug. CSCs were isolated by culture in defined media, under nonadherent conditions. The isolated CSCs were clonogenic, could be differentiated into adherent cells and were less sensitive to cisplatin than the original cells. Cisplatin resistant and CSCs were able to generate primary tumors and to metastasize when injected into immunodeficient Nu/Nu mice, although they formed smaller tumors with a larger latency than untreated cells. Notably, under appropriated proportions, CSCs synergized with differentiated cells to form larger tumors. CSCs also showed increased capacity to induce angiogenesis in Nu/Nu mice. Conversely, H460 cisplatin-resistant cells showed increased tendency to develop bone metastasis. Gene expression analysis showed that several genes involved in tumor development and metastasis (EGR1, COX2, MALAT1, AKAP12, ADM) were similarly induced in CSC and cisplatin-resistant H460 cells, in agreement with a close similarity between these two cell populations. Cells with the characteristic growth properties of CSCs were also isolated from surgical samples of 18 out of 44 lung cancer patients. A significant correlation (P = 0.028) was found between the absence of CSCs and cisplatin sensitivity. PMID:24961511

  15. The reversal of antineoplastic drug resistance in cancer cells by β-elemene.

    Science.gov (United States)

    Zhang, Guan-Nan; Ashby, Charles R; Zhang, Yun-Kai; Chen, Zhe-Sheng; Guo, Huiqin

    2015-11-01

    Multidrug resistance (MDR), defined as the resistance of cancer cells to compounds with diverse structures and mechanisms of actions, significantly limits the efficacy of antitumor drugs. A major mechanism that mediates MDR in cancer is the overexpression of adenosine triphosphate (ATP)-binding cassette transporters. These transporters bind to their respective substrates and catalyze their efflux from cancer cells, thereby lowering the intracellular concentrations of the substrates and thus attenuating or even abolishing their efficacy. In addition, cancer cells can become resistant to drugs via mechanisms that attenuate apoptosis and cell cycle arrest such as alterations in the p53, check point kinase, nuclear factor kappa B, and the p38 mitogen-activated protein kinase pathway. In this review, we discuss the mechanisms by which β-elemene, a compound extracted from Rhizoma zedoariae that has clinical antitumor efficacy, overcomes drug resistance in cancer. PMID:26370907

  16. Cancer stem cells, epithelial-mesenchymal transition, and drug resistance in high-grade ovarian serous carcinoma

    OpenAIRE

    Chen, Xiaoxiang; Zhang, Jing; Zhang, Zhihong; Li, Hongxia; CHENG, WENJUN; Liu, Jinsong

    2013-01-01

    Although epithelial ovarian cancer cells are eliminated by debulking surgery and chemotherapy during initial treatment, it is believed that only a subset of cancer cells, that is, cancer stem cells, may be an important source of tumor recurrence and drug resistance. This review highlights our current understanding of high-grade serous carcinoma, ovarian cancer stem cells, common methods for enrichment of ovarian cancer stem cells, mechanisms involved in drug resistance, and potential strategi...

  17. The ALK inhibitor ceritinib overcomes crizotinib resistance in non-small cell lung cancer

    OpenAIRE

    Friboulet, Luc; Li, Nanxin; Katayama, Ryohei; Lee, Christian C.; Gainor, Justin F.; Crystal, Adam S.; Michellys, Pierre-Yves; Awad, Mark M.; Yanagitani, Noriko; Kim, Sungjoon; Pferdekamper, AnneMarie C.; Li, Jie; Kasibhatla, Shailaja; Sun, Frank; Sun, Xiuying

    2014-01-01

    Non-small cell lung cancers (NSCLC) harboring anaplastic lymphoma kinase (ALK) gene rearrangements invariably develop resistance to the ALK tyrosine kinase inhibitor (TKI) crizotinib. Herein, we report the first preclinical evaluation of the next-generation ALK TKI, ceritinib (LDK378) in the setting of crizotinib resistance. Interrogation of in vitro and in vivo models of acquired resistance to crizotinib, including cell lines established from biopsies of crizotinib-resistant NSCLC patients r...

  18. Wound Healing and Cancer Stem Cells: Inflammation as a Driver of Treatment Resistance in Breast Cancer

    Science.gov (United States)

    Arnold, Kimberly M; Opdenaker, Lynn M; Flynn, Daniel; Sims-Mourtada, Jennifer

    2015-01-01

    The relationship between wound healing and cancer has long been recognized. The mechanisms that regulate wound healing have been shown to promote transformation and growth of malignant cells. In addition, chronic inflammation has been associated with malignant transformation in many tissues. Recently, pathways involved in inflammation and wound healing have been reported to enhance cancer stem cell (CSC) populations. These cells, which are highly resistant to current treatments, are capable of repopulating the tumor after treatment, causing local and systemic recurrences. In this review, we highlight proinflammatory cytokines and developmental pathways involved in tissue repair, whose deregulation in the tumor microenvironment may promote growth and survival of CSCs. We propose that the addition of anti-inflammatory agents to current treatment regimens may slow the growth of CSCs and improve therapeutic outcomes. PMID:25674014

  19. Aurora kinase B is important for antiestrogen resistant cell growth and a potential biomarker for tamoxifen resistant breast cancer

    DEFF Research Database (Denmark)

    Larsen, Sarah L; Yde, Christina W; Laenkholm, Anne-Vibeke;

    2015-01-01

    endocrine resistance, immunohistochemistry was performed on archival primary tumor tissue from breast cancer patients who have received adjuvant endocrine treatment with tamoxifen. RESULTS: The selective Aurora kinase B inhibitor barasertib was identified to preferentially inhibit growth of fulvestrant...... and PARP cleavage in the fulvestrant resistant cells. Barasertib also exerted preferential growth inhibition of tamoxifen resistant T47D cell lines. Finally, high percentage of Aurora kinase B positive tumor cells was significantly associated with reduced disease-free and overall survival in 261 ER......-positive breast cancer patients, who have received tamoxifen as first-line adjuvant endocrine treatment. CONCLUSIONS: Our results indicate that Aurora kinase B is a driving factor for growth of antiestrogen resistant T47D breast cancer cell lines, and a biomarker for reduced benefit of tamoxifen treatment. Thus...

  20. Reprogramming mediated radio-resistance of 3D-grown cancer cells

    International Nuclear Information System (INIS)

    In vitro 3D growth of tumors is a new cell culture model that more closely mimics the features of the in vivo environment and is being used increasingly in the field of biological and medical research. It has been demonstrated that cancer cells cultured in 3D matrices are more radio-resistant compared with cells in monolayers. However, the mechanisms causing this difference remain unclear. Here we show that cancer cells cultured in a 3D microenvironment demonstrated an increase in cells with stem cell properties. This was confirmed by the finding that cells in 3D cultures upregulated the gene and protein expression of the stem cell reprogramming factors such as OCT4, SOX2, NANOG, LIN28 and miR-302a, compared with cells in monolayers. Moreover, the expression of β-catenin, a regulating molecule of reprogramming factors, also increased in 3D-grown cancer cells. These findings suggest that cancer cells were reprogrammed to become stem cell-like cancer cells in a 3D growth culture microenvironment. Since cancer stem cell-like cells demonstrate an increased radio-resistance and chemo-resistance, our results offer a new perspective as to why. Our findings shed new light on understanding the features of the 3D growth cell model and its application in basic research into clinical radiotherapy and medicine. (author)

  1. Combining targeted drugs to overcome and prevent resistance of solid cancers with some stem-like cell features

    OpenAIRE

    Jokinen, Elina; Laurila, Niina; Koivunen, Peppi; Koivunen, Jussi P

    2014-01-01

    Treatment resistance significantly inhibits the efficiency of targeted cancer therapies in drug-sensitive genotypes. In the current work, we studied mechanisms for rapidly occurring, adaptive resistance in targeted therapy-sensitive lung, breast, and melanoma cancer cell lines. The results show that in ALK translocated lung cancer lines H3122 and H2228, cells with cancer stem-like cell features characterized by high expression of cancer stem cell markers and/or in vivo tumorigenesis can media...

  2. Fallopia japonica, a Natural Modulator, Can Overcome Multidrug Resistance in Cancer Cells

    OpenAIRE

    Safaa Yehia Eid; Mahmoud Zaki El-Readi; Mohamed Lotfy Ashour; Michael Wink

    2015-01-01

    Resistance of cancer cells to chemotherapy is controlled by the decrease of intracellular drug accumulation, increase of detoxification, and diminished propensity of cancer cells to undergo apoptosis. ATP-binding cassette (ABC) membrane transporters with intracellular metabolic enzymes contribute to the complex and unresolved phenomenon of multidrug resistance (MDR). Natural products as alternative medicine have great potential to discover new MDR inhibitors with diverse modes of action. In t...

  3. Enzyme-Regulated Supramolecular Assemblies of Cholesterol Conjugates against Drug-Resistant Ovarian Cancer Cells.

    Science.gov (United States)

    Wang, Huaimin; Feng, Zhaoqianqi; Wu, Dongdong; Fritzsching, Keith J; Rigney, Mike; Zhou, Jie; Jiang, Yujie; Schmidt-Rohr, Klaus; Xu, Bing

    2016-08-31

    We report that phosphotyrosine-cholesterol conjugates effectively and selectively kill cancer cells, including platinum-resistant ovarian cancer cells. The conjugate increases the degree of noncovalent oligomerization upon enzymatic dephosphorylation in aqueous buffer. This enzymatic conversion also results in the assembly of the cholesterol conjugates inside and outside cells and leads to cell death. Preliminary mechanistic studies suggest that the formed assemblies of the conjugates not only interact with actin filaments and microtubules but also affect lipid rafts. As the first report of multifaceted supramolecular assemblies of cholesterol conjugates against cancer cells, this work illustrates the integration of enzyme catalysis and self-assembly of essential biological small molecules on and inside cancer cells as a promising strategy for developing multifunctional therapeutics to treat drug-resistant cancers. PMID:27529637

  4. The stepwise evolution of the exome during acquisition of docetaxel resistance in breast cancer cells

    DEFF Research Database (Denmark)

    Hansen, Stine Ninel; Ehlers, Natasja Spring; Zhu, Shida;

    2016-01-01

    Background: Resistance to taxane-based therapy in breast cancer patients is a major clinical problem that may be addressed through insight of the genomic alterations leading to taxane resistance in breast cancer cells. In the current study we used whole exome sequencing to discover somatic genomic...... concentrations of docetaxel. Whole exome sequencing performed at five successive stages during this process was used to identify single point mutational events, insertions/deletions and copy number alterations associated with the acquisition of docetaxel resistance. Acquired coding variation undergoing positive...... genomic event sufficiently predicts resistance to docetaxel, but require genomic alterations affecting multiple pathways that in concert establish the final resistance stage....

  5. Circumvention of multi-drug resistance of cancer cells by Chinese herbal medicines

    OpenAIRE

    Chai, Stella; To, Kenneth KW; Lin, Ge

    2010-01-01

    Multi-drug resistance (MDR) of cancer cells severely limits therapeutic outcomes. A proposed mechanism for MDR involves the efflux of anti-cancer drugs from cancer cells, primarily mediated by ATP-binding cassette (ABC) membrane transporters including P-glycoprotein. This article reviews the recent progress of using active ingredients, extracts and formulae from Chinese medicine (CM) in circumventing ABC transporters-mediated MDR. Among the ABC transporters, Pgp is the most extensively studie...

  6. Gambogic acid inhibits growth, induces apoptosis, and overcomes drug resistance in human colorectal cancer cells.

    Science.gov (United States)

    Wen, Chuangyu; Huang, Lanlan; Chen, Junxiong; Lin, Mengmeng; Li, Wen; Lu, Biyan; Rutnam, Zina Jeyapalan; Iwamoto, Aikichi; Wang, Zhongyang; Yang, Xiangling; Liu, Huanliang

    2015-11-01

    The emergence of chemoresistance is a major limitation of colorectal cancer (CRC) therapies and novel biologically based therapies are urgently needed. Natural products represent a novel potential anticancer therapy. Gambogic acid (GA), a small molecule derived from Garcinia hanburyi Hook. f., has been demonstrated to be highly cytotoxic to several types of cancer cells and have low toxicity to the hematopoietic system. However, the potential role of GA in colorectal cancer and its ability to overcome the chemotherapeutic resistance in CRC cells have not been well studied. In the present study, we showed that GA directly inhibited proliferation and induced apoptosis in both 5-fluorouracil (5-FU) sensitive and 5-FU resistant colorectal cancer cells; induced apoptosis via activating JNK signaling pathway. The data, therefore, suggested an alternative strategy to overcome 5-FU resistance in CRC and that GA could be a promising medicinal compound for colorectal cancer therapy. PMID:26397804

  7. Transmembrane transporters ABCC – structure, function and role in multidrug resistance of cancer cells

    Directory of Open Access Journals (Sweden)

    Sylwia Dębska

    2011-08-01

    Full Text Available Resistance to cytotoxic drugs is a significant problem of systemic treatment of cancers. Apart from drug inactivation, changes in target enzymes and proteins, increased DNA repair and suppression of apoptosis, an important mechanism of resistance is an active drug efflux from cancer cells. Drug efflux across the cell membrane is caused by transport proteins such as ABC proteins (ATP-binding cassette. This review focuses on the ABCC protein subfamily, whose members are responsible for multidrug cross-resistance of cancer cells to cytotoxic agents. The authors discuss the structure of ABCC proteins, their physiological function and diseases provoked by mutations of respective genes, their expression in many different malignancies and its connection with resistance to anticancer drugs, as well as methods of reversion of such resistance.

  8. Overcoming cancer cell resistance to VSV oncolysis with JAK1/2 inhibitors

    OpenAIRE

    Escobar-Zarate, D; Liu, Y-P; Suksanpaisan, L; Russell, SJ; Peng, K-W

    2013-01-01

    Oncolytic vesicular stomatitis virus (VSV) has potent antitumor activity but some cancer cells are resistant to VSV killing, either constitutively or due to type I interferon (IFN) inducing an antiviral state in the cells. Here, we evaluated VSV oncolysis of a panel of human head and neck cancer cells and showed that VSV resistance in SCC25 and SCC15 cells could be reversed with Janus kinase (JAK) 1/2 inhibitors (JAK inhibitor I and ruxolitinib). Pre-treatment of cells with JAK1/2 inhibitors ...

  9. Up-regulation of fas reverses cisplatin resistance of human small cell lung cancer cells

    Directory of Open Access Journals (Sweden)

    Wu Wei

    2010-05-01

    Full Text Available Abstract Background/Aim Fas/FasL system is a major regulator of apoptosis. The mechanisms by which Fas mediates cisplatin resistance remain unclear. The aim of this study is to explore the effect of Fas over-expression on cisplatin resistance of small cell lung cancer cells and its possible mechanisms. Materials and methods Fas was over-expressed in H446/CDDP cells by infection with the adenoviruses containing Fas. Sensitivity of Fas-overexpressed H446/CDDP cells to cisplatin was evaluated using MTT assay. Expressions of Fas, GST-π and ERCC1 were detected by RT-PCR and Western blot analysis. Apoptosis rate was examined by FACS. Results Over-expression of Fas in H446/CDDP cells significantly decreased the expressions of GST-π and ERCC1 at mRNA and protein levels, and increased the cell apoptosis. Furthermore, up-regulation of Fas significantly decreased the tolerance of H446/CDDP cells to cisplatin. Conclusion Over-expression of Fas reverses drug resistance of H446/CDDP cells, possibly due to the increased cell sensitivity to apoptosis and the decreased expressions of GST-π and ERCC1.

  10. The role of Nanog expression in tamoxifen-resistant breast cancer cells

    Directory of Open Access Journals (Sweden)

    Arif K

    2015-06-01

    Full Text Available Khalid Arif,1 Issam Hussain,1 Carol Rea,1 Mohamed El-Sheemy2 1School of Life Sciences, University of Lincoln, Brayford Pool, 2Lincoln County Hospital, Greetwell Road, Lincoln, Lincolnshire, UK Abstract: There is an accumulation of evidence that shows a significant role of cancer stem cells in tumor initiation, proliferation, relapse, and metastasis. Nanog is the most important core transcription marker of stem cells, known by its role in maintaining pluripotency, proliferation, and differentiation. Therefore, this study aimed to examine the role of Nanog in breast cancer cell tamoxifen resistance and its implications in breast cancer treatment. In this study, the expression of the three core transcription markers Nanog, Oct3/4, and Sox2 were quantitatively evaluated using flow cytometry. Then, small interfering RNA (siRNA against human Nanog was transfected into tamoxifen-resistant breast cancer cells via Lipofectamine 2000. Nanog gene expression in the cells was detected using reverse transcription polymerase chain reaction (RT-PCR. The change in cell proliferation was evaluated using the tetrazolium bromide method. An enzyme-linked immunosorbent assay was used to detect apoptosis of the transfected cells alone and in combination with 4-hydroxytamoxifen. The results showed a high level expression of Nanog, Oct3/4, and Sox2 in MDA-MB-231 and MCF7/tamoxifen resistant cells compared with MCF7/wild-type. siRNA-mediated Nanog gene silencing can efficiently inhibit cell proliferation and induce apoptosis of tamoxifen-resistant breast cancer cells. This study provides a basis for further study of the role of Nanog in developing resistance to tamoxifen, its implication in breast cancer management, and as a new strategy to enhance response to endocrine therapy. Keywords: breast cancer, cancer stem cell, Nanog, tamoxifen, estrogen receptor

  11. Multiple mechanisms underlying acquired resistance to taxanes in selected docetaxel-resistant MCF-7 breast cancer cells

    International Nuclear Information System (INIS)

    Chemoresistance is a major factor involved in a poor response and reduced overall survival in patients with advanced breast cancer. Although extensive studies have been carried out to understand the mechanisms of chemoresistance, many questions remain unanswered. In this research, we used two isogenic MCF-7 breast cancer cell lines selected for resistance to doxorubicin (MCF-7DOX) or docetaxel (MCF-7TXT) and the wild type parental cell line (MCF-7CC) to study mechanisms underlying acquired resistance to taxanes in MCF-7TXT cells. Cytotoxicity assay, immunoblotting, indirect immunofluorescence and live imaging were used to study the drug resistance, the expression levels of drug transporters and various tubulin isoforms, apoptosis, microtubule formation, and microtubule dynamics. MCF-7TXT cells were cross resistant to paclitaxel, but not to doxorubicin. MCF-7DOX cells were not cross-resistant to taxanes. We also showed that multiple mechanisms are involved in the resistance to taxanes in MCF-7TXT cells. Firstly, MCF-7TXT cells express higher level of ABCB1. Secondly, the microtubule dynamics of MCF-7TXT cells are weak and insensitive to the docetaxel treatment, which may partially explain why docetaxel is less effective in inducing M-phase arrest and apoptosis in MCF-7TXT cells in comparison with MCF-7CC cells. Moreover, MCF-7TXT cells express relatively higher levels of β2- and β4-tubulin and relatively lower levels of β3-tubulin than both MCF-7CC and MCF-7DOX cells. The subcellular localization of various β-tubulin isoforms in MCF-7TXT cells is also different from that in MCF-7CC and MCF-7DOX cells. Multiple mechanisms are involved in the resistance to taxanes in MCF-7TXT cells. The high expression level of ABCB1, the specific composition and localization of β-tubulin isoforms, the weak microtubule dynamics and its insensitivity to docetaxel may all contribute to the acquired resistance of MCF-7TXT cells to taxanes

  12. Molecular mechanisms of heptaplatin effective against cisplatin-resistant cancer cell lines: less involvement of metallothionein

    Directory of Open Access Journals (Sweden)

    Moon Sung-Pyo

    2004-10-01

    Full Text Available Abstract Background Heptaplatin is a new platinum derivative with anticancer activity against various cancer cell lines, including cisplatin-resistant cancer cell lines (Cancer Chemother Pharmacol 1995; 35: 441. Methods Molecular mechanisms of heptaplatin effective against cisplatin-resistant cancer cell lines has been investigated in connection with metallothionein (MT. Cytotoxicity was determined by an MTT assay. MT mRNA, was determined by RT-PCR assay. Transfection study was carried out to examine the function of MT. Results Of various gastric cancer cell lines, SNU-638 and SNU-601 showed the highest and lowest levels of MT mRNA, respectively, showing 80-fold difference. The IC50 values of SNU-638 to cisplatin, carboplatin and heptaplatin were 11.2-fold, 5.1-fold and 2.0-fold greater than those of SNU-601, respectively. Heptaplatin was more effective against cisplatin-resistant and MT-transfected gastric cancer sublines than cisplatin or carboplatin was. In addition, heptaplatin attenuated cadmium, but not zinc, induction of MT. Conclusion These results indicate that molecular mechanisms of heptaplatin effective against cisplatin-resistant gastric cancer sublines is at least in part due to the less involvement of MT in heptaplatin resistance as well as its attenuation of MT induction.

  13. Cancer and malignant resistance of cells as phenomena of adaptation to damaging factors.

    Science.gov (United States)

    Monceviciute-Eringiene, E

    1996-05-01

    I propose the hypothesis that mechanisms of general biological persistent resistance to damaging factors are closely related to the development of tumour cells. This phenomenon is characteristic of bacterial variants whose resistance to antibiotics and other chemotherapeutic drugs appears through L-transformation. As somatic cells are exposed to carcinogens and develop into tumour cells, they also acquire resistance to the toxic effects of carcinogens through multistage malignant transformation. Many cancerous cells, which have acquired persistent resistance to chemotherapy drugs or irradiation, often reappear locally or in metastases after courses of treatment. Thus, these cells undergo a kind of repeated development of malignancy. After a certain remission period, they begin to multiply more intensively locally, and are more likely to spread by metastasis. All resistant cells have the following characteristics: simplified metabolism, genetic, biochemical and morphological properties; lower requirements from their nutrient medium; rapid growth; parasitic qualities; invasiveness. It is as if they regress into a more primitive mode of existence (atavism) to survive under unfavourable circumstances. Somatic cells, resistant to carcinogens and the cells which undergo progression to more malignant types under the influence of drugs become similar to unicellular organisms or to forms of the latter which are resistant to damaging factors. The more primitive the cells become, the better they survive. Thus, cancer is a special case of the general resistance of cells to damaging factors. PMID:8735884

  14. Role of Metallothionein1H in Cisplatin Resistance of Non-Small Cell Lung Cancer Cells

    Institute of Scientific and Technical Information of China (English)

    Xin-fang Hou; Qing-xia Fan; Liu-xing Wang; Shi-xin Lu

    2009-01-01

    Objective: Despite platinum-based adjuvant chemotherapy has improved greatly patients' outcomes, drug resistance poses a major impediment to the successful use of such an effective agent. Metallothioneins(MTs) are known to play putative roles in cancer cell proliferation, apoptosis, differentiation, drug resistance and prognosis. The present studiy was to investigte the role of metallethioein1H(MT1H) in cisplatin resistance of human non-small cell lung cancer(NSCLC) cell lines in vitro or its possible molecular mechanisms. Methods: MT1H mRNA expression in A549 and A549/DDP cells was detected by RT-PCR. A recombinant eukaryotic expression plasmid pcDNA3.1(-)-MT1H was constructed and transfected into A549 cells which express no MT1H. MT1H siRNA was transfected into A549/DDP cells which express MT1H highly. MT1H expression was detected by RT-PCR and Immunoblot. The chemosensitivity to cisplatin was assessed by MTT assay. Apoptosis rate was determined by Tunel and FCM. Bcl-2 and Bax were determined by immunohistochemistry. Results: MT1H mRNA was expressed in A549/DDP but not in A549. After transfection of MT1H, MT1H expression was enhanced and the chemosensitivity to cisplatin was decreased in A549 cells. Inversely, after transfection of MT1H siRNA, MT1H expression was decreased and the chemosensitivity to cisplatin was increased in A549/DDP. The apoptosis rate induced by cisplatin was increased and Bcl-2 was down-regulated but Bax showed little change in A549/DDP cells interferred with MT1H siRNA. Conclusion: MT1H overexpression can promote drug resistance in A549 cells . Down-regulation of MT1H interfered with siRNA can effectively reverses the drug resistance in A549/DDP cells by down-regulating the expression of Bcl-2 and increasing cisplatin induced apoptosis. SiRNA targeting MT1H combined with chemotherapy may be a very promising strategy for treatment of lung cancer.

  15. A new MCF-7 breast cancer cell line resistant to the arzoxifene metabolite desmethylarzoxifene

    DEFF Research Database (Denmark)

    Freddie, Cecilie T; Christensen, Gitte Lund; Lykkesfeldt, Anne E

    2004-01-01

    The development of resistance in tamoxifen-treated breast cancer patients and the estrogenic side effects of tamoxifen have lead to the design of many new drugs. The new SERM arzoxifene and its active metabolite desmethylarzoxifene (ARZm) inhibits growth of breast cancer cells and has less estrog...

  16. MUC1-C ONCOPROTEIN INDUCES TAMOXIFEN RESISTANCE IN HUMAN BREAST CANCER CELLS

    OpenAIRE

    Kharbanda, Akriti; Rajabi, Hasan; Jin, Caining; Raina, Deepak; Kufe, Donald

    2013-01-01

    Resistance of estrogen receptor positive (ER+) breast cancer cells to tamoxifen has been linked in part to activation of (i) certain receptor tyrosine kinases, such as HER2, and (ii) the PI3K→AKT pathway. Mucin 1 (MUC1) is aberrantly overexpressed in about 90% of human breast cancers and the oncogenic MUC1-C subunit associates with ERα. The present studies using HER2 overexpressing BT-474 breast cancer cells, which are constitutively resistant to tamoxifen, demonstrate that silencing MUC1-C i...

  17. Multidrug resistance and retroviral transduction potential in human small cell lung cancer cell lines

    DEFF Research Database (Denmark)

    Theilade, M D; Gram, G J; Jensen, P B;

    1999-01-01

    Multidrug resistance (MDR) remains a major problem in the successful treatment of small cell lung cancer (SCLC). New treatment strategies are needed, such as gene therapy specifically targeting the MDR cells in the tumor. Retroviral LacZ gene-containing vectors that were either pseudotyped...... for the gibbon ape leukemia virus (GALV-1) receptor or had specificity for the amphotropic murine leukemia virus (MLV-A) receptor were used for transduction of five SCLC cell lines differing by a range of MDR mechanisms. Transduction efficiencies in these cell lines were compared by calculating the percentage...... of blue colonies after X-Gal staining of the cells grown in soft agar. All examined SCLC cell lines were transducible with either vector. Transduction efficiencies varied from 5.7% to 33.5% independent of the presence of MDR. These results indicate that MDR does not severely impair transduction of SCLC...

  18. Multidrug resistance and retroviral transduction potential in human small cell lung cancer cell lines

    DEFF Research Database (Denmark)

    Theilade, M D; Gram, G J; Jensen, P B;

    1999-01-01

    blue colonies after X-Gal staining of the cells grown in soft agar. All examined SCLC cell lines were transducible with either vector. Transduction efficiencies varied from 5.7% to 33.5% independent of the presence of MDR. These results indicate that MDR does not severely impair transduction of SCLC......Multidrug resistance (MDR) remains a major problem in the successful treatment of small cell lung cancer (SCLC). New treatment strategies are needed, such as gene therapy specifically targeting the MDR cells in the tumor. Retroviral LacZ gene-containing vectors that were either pseudotyped for the...... gibbon ape leukemia virus (GALV-1) receptor or had specificity for the amphotropic murine leukemia virus (MLV-A) receptor were used for transduction of five SCLC cell lines differing by a range of MDR mechanisms. Transduction efficiencies in these cell lines were compared by calculating the percentage of...

  19. PTEN overexpression improves cisplatin-resistance of human ovarian cancer cells through upregulating KRT10 expression

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Huijuan; Wang, Ke; Liu, Wenxin; Hao, Quan, E-mail: quan_haotj@126.com

    2014-02-07

    Highlights: • Overexpression of PTEN enhanced the sensitivity of C13K cells to cisplatin. • KRT10 is a downstream molecule of PTEN involved in the resistance-reversing effect. • Overexpression of KRT10 enhanced the chemosensitivity of C13K cells to cisplatin. - Abstract: Multi-drug resistance (MDR) is a common cause of the failure of chemotherapy in ovarian cancer. PTEN, a tumor suppressor gene, has been demonstrated to be able to reverse cisplatin-resistance in ovarian cancer cell line C13K. However, the downstream molecules of PTEN involved in the resistance-reversing effect have not been completely clarified. Therefore, we screened the downstream molecules of PTEN and studied their interactions in C13K ovarian cancer cells using a 3D culture model. Firstly, we constructed an ovarian cancer cell line stably expressing PTEN, C13K/PTEN. MTT assay showed that overexpression of PTEN enhanced the sensitivity of C13K cells to cisplatin, but not to paclitaxel. Then we examined the differently expressed proteins that interacted with PTEN in C13K/PTEN cells with or without cisplatin treatment by co-immunoprecipitation. KRT10 was identified as a differently expressed protein in cisplatin-treated C13K/PTEN cells. Further study confirmed that cisplatin could induce upregulation of KRT10 mRNA and protein in C13K/PTEN cells and there was a directly interaction between KRT10 and PTEN. Forced expression of KRT10 in C13K cells also enhanced cisplatin-induced proliferation inhibition and apoptosis of C13K cells. In addition, KRT10 siRNA blocked cisplatin-induced proliferation inhibition of C13K/PTEN cells. In conclusion, our data demonstrate that KRT10 is a downstream molecule of PTEN which improves cisplatin-resistance of ovarian cancer and forced KRT10 overexpression may also act as a therapeutic method for overcoming MDR in ovarian cancer.

  20. PTEN overexpression improves cisplatin-resistance of human ovarian cancer cells through upregulating KRT10 expression

    International Nuclear Information System (INIS)

    Highlights: • Overexpression of PTEN enhanced the sensitivity of C13K cells to cisplatin. • KRT10 is a downstream molecule of PTEN involved in the resistance-reversing effect. • Overexpression of KRT10 enhanced the chemosensitivity of C13K cells to cisplatin. - Abstract: Multi-drug resistance (MDR) is a common cause of the failure of chemotherapy in ovarian cancer. PTEN, a tumor suppressor gene, has been demonstrated to be able to reverse cisplatin-resistance in ovarian cancer cell line C13K. However, the downstream molecules of PTEN involved in the resistance-reversing effect have not been completely clarified. Therefore, we screened the downstream molecules of PTEN and studied their interactions in C13K ovarian cancer cells using a 3D culture model. Firstly, we constructed an ovarian cancer cell line stably expressing PTEN, C13K/PTEN. MTT assay showed that overexpression of PTEN enhanced the sensitivity of C13K cells to cisplatin, but not to paclitaxel. Then we examined the differently expressed proteins that interacted with PTEN in C13K/PTEN cells with or without cisplatin treatment by co-immunoprecipitation. KRT10 was identified as a differently expressed protein in cisplatin-treated C13K/PTEN cells. Further study confirmed that cisplatin could induce upregulation of KRT10 mRNA and protein in C13K/PTEN cells and there was a directly interaction between KRT10 and PTEN. Forced expression of KRT10 in C13K cells also enhanced cisplatin-induced proliferation inhibition and apoptosis of C13K cells. In addition, KRT10 siRNA blocked cisplatin-induced proliferation inhibition of C13K/PTEN cells. In conclusion, our data demonstrate that KRT10 is a downstream molecule of PTEN which improves cisplatin-resistance of ovarian cancer and forced KRT10 overexpression may also act as a therapeutic method for overcoming MDR in ovarian cancer

  1. Cetuximab-Induced MET Activation Acts as a Novel Resistance Mechanism in Colon Cancer Cells

    Directory of Open Access Journals (Sweden)

    Na Song

    2014-04-01

    Full Text Available Aberrant MET expression and hepatocyte growth factor (HGF signaling are implicated in promoting resistance to targeted agents; however, the induced MET activation by epidermal growth factor receptor (EGFR inhibitors mediating resistance to targeted therapy remains elusive. In this study, we identified that cetuximab-induced MET activation contributed to cetuximab resistance in Caco-2 colon cancer cells. MET inhibition or knockdown sensitized Caco-2 cells to cetuximab-mediated growth inhibition. Additionally, SRC activation promoted cetuximab resistance by interacting with MET. Pretreatment with SRC inhibitors abolished cetuximab-mediated MET activation and rendered Caco-2 cells sensitive to cetuximab. Notably, cetuximab induced MET/SRC/EGFR complex formation. MET inhibitor or SRC inhibitor suppressed phosphorylation of MET and SRC in the complex, and MET inhibitor singly led to disruption of complex formation. These results implicate alternative targeting of MET or SRC as rational strategies for reversing cetuximab resistance in colon cancer.

  2. Cancer stem cell overexpression of nicotinamide N-methyltransferase enhances cellular radiation resistance

    DEFF Research Database (Denmark)

    D’Andrea, Filippo P.; Safwat, Akmal; Kassem, Moustapha; Gautier, Laurent; Overgaard, Jens; Horsman, Michael R.

    2011-01-01

    BackgroundCancer stem cells are thought to be a radioresistant population and may be the seeds for recurrence after radiotherapy. Using tumorigenic clones of retroviral immortalized human mesenchymal stem cell with small differences in their phenotype, we investigated possible genetic expression...... analysis found the genes involved in cancer, proliferation, DNA repair and cell death. ConclusionsThe higher radiation resistance in clone CE8 is likely due to NNMT overexpression. The higher levels of NNMT could affect the cellular damage resistance through depletion of the accessible amounts of...... nicotinamide, which is a known inhibitor of cellular DNA repair mechanisms....

  3. Drug resistance, and the role of p53, in lung cancer cell lines

    OpenAIRE

    Breen, Laura

    2005-01-01

    This thesis sets out to increase our knowledge of mechanisms by which lung cancer cells develop resistance to chemotherapeutic agents. The involvement of the tumour suppressor p53 in the development of drug resistance in lung cancer cell lines was investigated. p53 is a tumour suppressor gene, which is mutated in more than half of all tumours. Most chemotherapeutic drugs cause DNA damage that is sensed by p53, which either arrests the cell cycle to allow DNA repair or induces apoptosis. Wildt...

  4. Ell3 stimulates proliferation, drug resistance, and cancer stem cell properties of breast cancer cells via a MEK/ERK-dependent signaling pathway

    International Nuclear Information System (INIS)

    Highlights: •Ell3 enhances proliferation and drug resistance of breast cancer cell lines. •Ell3 is related to the cancer stem cell characteristics of breast cancer cell lines. •Ell3 enhances oncogenicity of breast cancer through the ERK1/2 signaling pathway. -- Abstract: Ell3 is a RNA polymerase II transcription elongation factor that is enriched in testis. The C-terminal domain of Ell3 shows strong similarities to that of Ell (eleven−nineteen lysine-rich leukemia gene), which acts as a negative regulator of p53 and regulates cell proliferation and survival. Recent studies in our laboratory showed that Ell3 induces the differentiation of mouse embryonic stem cells by protecting differentiating cells from apoptosis via the promotion of p53 degradation. In this study, we evaluated the function of Ell3 in breast cancer cell lines. MCF-7 cell lines overexpressing Ell3 were used to examine cell proliferation and cancer stem cell properties. Ectopic expression of Ell3 in breast cancer cell lines induces proliferation and 5-FU resistance. In addition, Ell3 expression increases the cancer stem cell population, which is characterized by CD44 (+) or ALDH1 (+) cells. Mammosphere-forming potential and migration ability were also increased upon Ell3 expression in breast cancer cell lines. Through biochemical and molecular biological analyses, we showed that Ell3 regulates proliferation, cancer stem cell properties and drug resistance in breast cancer cell lines partly through the MEK−extracellular signal-regulated kinase signaling pathway. Murine xenograft experiments showed that Ell3 expression promotes tumorigenesis in vivo. These results suggest that Ell3 may play a critical role in promoting oncogenesis in breast cancer by regulating cell proliferation and cancer stem cell properties via the ERK1/2 signaling pathway

  5. Ell3 stimulates proliferation, drug resistance, and cancer stem cell properties of breast cancer cells via a MEK/ERK-dependent signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Hee-Jin [Department of Biomedical Science, College of Life Science, CHA University, Seoul (Korea, Republic of); Kim, Gwangil [Department of Pathology, CHA Bundang Medical Center, CHA University, Seoul (Korea, Republic of); Park, Kyung-Soon, E-mail: kspark@cha.ac.kr [Department of Biomedical Science, College of Life Science, CHA University, Seoul (Korea, Republic of)

    2013-08-09

    Highlights: •Ell3 enhances proliferation and drug resistance of breast cancer cell lines. •Ell3 is related to the cancer stem cell characteristics of breast cancer cell lines. •Ell3 enhances oncogenicity of breast cancer through the ERK1/2 signaling pathway. -- Abstract: Ell3 is a RNA polymerase II transcription elongation factor that is enriched in testis. The C-terminal domain of Ell3 shows strong similarities to that of Ell (eleven−nineteen lysine-rich leukemia gene), which acts as a negative regulator of p53 and regulates cell proliferation and survival. Recent studies in our laboratory showed that Ell3 induces the differentiation of mouse embryonic stem cells by protecting differentiating cells from apoptosis via the promotion of p53 degradation. In this study, we evaluated the function of Ell3 in breast cancer cell lines. MCF-7 cell lines overexpressing Ell3 were used to examine cell proliferation and cancer stem cell properties. Ectopic expression of Ell3 in breast cancer cell lines induces proliferation and 5-FU resistance. In addition, Ell3 expression increases the cancer stem cell population, which is characterized by CD44 (+) or ALDH1 (+) cells. Mammosphere-forming potential and migration ability were also increased upon Ell3 expression in breast cancer cell lines. Through biochemical and molecular biological analyses, we showed that Ell3 regulates proliferation, cancer stem cell properties and drug resistance in breast cancer cell lines partly through the MEK−extracellular signal-regulated kinase signaling pathway. Murine xenograft experiments showed that Ell3 expression promotes tumorigenesis in vivo. These results suggest that Ell3 may play a critical role in promoting oncogenesis in breast cancer by regulating cell proliferation and cancer stem cell properties via the ERK1/2 signaling pathway.

  6. Overexpression of Cathepsin L is associated with gefitinib resistance in non-small cell lung cancer.

    Science.gov (United States)

    Cui, F; Wang, W; Wu, D; He, X; Wu, J; Wang, M

    2016-07-01

    Lung cancer, the most common malignancy, is still the leading cause of cancer-related death worldwide. Non-small-cell lung cancer (NSCLC) accounts for 80 % of all lung cancers. Recent studies showed Cathepsin L (CTSL) is overexpressed in various cancerous tissues; however, the association between CTSL expression and EGFR-TKI resistance remains unknown. In this study, we investigated the expression of CTSL in lung cancer specimens and matched normal tissues by quantitative real-time PCR and IHC. The functional role of CTSL in resistant PC-9/GR cell line was investigated by proliferation and apoptosis analysis compared with control PC-9 cells. Our results found that the level of CTSL expression was higher in NSCLC tissues compared with matched normal adjacent tissue samples, and CTSL was more highly expressed in PC-9/GR cells compared to PC-9 cells. Knocking-down of CTSL in PC-9/GR cells could decrease cell proliferation and potentiate apoptosis induced by gefitinib, suggesting CTSL may contribute to gefitinib resistance in NSCLC. CTSL might be explored as a candidate of therapeutic target for modulating EGFR-TKI sensitivity in NSCLC. PMID:26474873

  7. Generation of a predictive melphalan resistance index by drug screen of B-cell cancer cell lines.

    Directory of Open Access Journals (Sweden)

    Martin Boegsted

    Full Text Available BACKGROUND: Recent reports indicate that in vitro drug screens combined with gene expression profiles (GEP of cancer cell lines may generate informative signatures predicting the clinical outcome of chemotherapy. In multiple myeloma (MM a range of new drugs have been introduced and now challenge conventional therapy including high dose melphalan. Consequently, the generation of predictive signatures for response to melphalan may have a clinical impact. The hypothesis is that melphalan screens and GEPs of B-cell cancer cell lines combined with multivariate statistics may provide predictive clinical information. MATERIALS AND METHODS: Microarray based GEPs and a melphalan growth inhibition screen of 59 cancer cell lines were downloaded from the National Cancer Institute database. Equivalent data were generated for 18 B-cell cancer cell lines. Linear discriminant analyses (LDA, sparse partial least squares (SPLS and pairwise comparisons of cell line data were used to build resistance signatures from both cell line panels. A melphalan resistance index was defined and estimated for each MM patient in a publicly available clinical data set and evaluated retrospectively by Cox proportional hazards and Kaplan-Meier survival analysis. PRINCIPAL FINDINGS: Both cell line panels performed well with respect to internal validation of the SPLS approach but only the B-cell panel was able to predict a significantly higher risk of relapse and death with increasing resistance index in the clinical data sets. The most sensitive and resistant cell lines, MOLP-2 and RPMI-8226 LR5, respectively, had high leverage, which suggests their differentially expressed genes to possess important predictive value. CONCLUSION: The present study presents a melphalan resistance index generated by analysis of a B-cell panel of cancer cell lines. However, the resistance index needs to be functionally validated and correlated to known MM biomarkers in independent data sets in order to

  8. Vimentin and Ki67 expression in circulating tumour cells derived from castrate-resistant prostate cancer

    OpenAIRE

    Lindsay, C. R.; Le Moulec, S.; Billiot, F.; Loriot, Y; Ngo-Camus, M.; Vielh, P; Fizazi, K; Massard, C; Farace, F.

    2016-01-01

    Background High circulating tumor cell (CTC) counts are associated with poor prognosis in advanced prostate cancer, and recently CTC number was suggested to be a surrogate for survival in metastatic castrate-resistant prostate cancer (mCRPC). Ki67 and vimentin are well-characterised markers of tumour cell proliferation and the epithelial-mesenchymal transition (EMT), respectively. Here we asked if the expression of vimentin and Ki67 in CTCs offered prognostic or predictive information in mCRP...

  9. Methotrexate-conjugated quantum dots: synthesis, characterisation and cytotoxicity in drug resistant cancer cells.

    Science.gov (United States)

    Johari-Ahar, Mohammad; Barar, Jaleh; Alizadeh, Ali Mohammad; Davaran, Soodabeh; Omidi, Yadollah; Rashidi, Mohammad-Reza

    2016-01-01

    Methotrexate (MTX), a folic acid derivative, is a potent anticancer used for treatment of different malignancies, but possible initiation of drug resistance to MTX by cancer cells has limited its applications. Nanoconjugates (NCs) of MTX to quantum dots (QDs) may favour the cellular uptake via folate receptors (FRs)-mediated endocytosis that circumvents the efflux functions of cancer cells. We synthesised MTX-conjugated l-cysteine capped CdSe QDs (MTX-QD nanoconjugates) and evaluated their internalisation and cytotoxicity in the KB cells with/without resistancy to MTX. The NCs were fully characterised by high resolution transmission electron microscopy (HR-TEM), atomic force microscopy (AFM), dynamic light scattering (DLS) and optical spectroscopy. Upon conjugation with MTX, the photoluminescence (PL) properties of QDs altered, while an obvious quenching in PL of QDs was observed after physical mixing. The MTX-QD nanoconjugates efficiently internalised into the cancer cells, and induced markedly high cytotoxicity (IC50, 12.0 µg/mL) in the MTX-resistant KB cells as compared to the free MTX molecules (IC50,105.0 µg/mL), whereas, these values were respectively about 7.0 and 0.6 µg/mL in the MTX-sensitive KB cells. Based on these findings, the MTX-QD nanoconjugates are proposed for the targeted therapy of MTX-resistant cancers, which may provide an improved outcome in the relapsed FR-overexpressing cancers. PMID:26176269

  10. Saikosaponin-d: A potential chemotherapeutics in castration resistant prostate cancer by suppressing cancer metastases and cancer stem cell phenotypes.

    Science.gov (United States)

    Zhong, Di; Zhang, Hui-Jian; Jiang, Yao-Dong; Wu, Peng; Qi, Huan; Cai, Chao; Zheng, Shao-Bin; Dang, Qiang

    2016-06-10

    Androgen deprivation therapy is the gold standard regimen for advanced Prostate cancer (PCa) patients, nevertheless, patients eventually develop into castration-resistant prostate cancer (CRPC). Currently only a few chemotherapeutics are available for CRPC. Therefore, it is critical for identifying a new drug. In this study, we will explore a new agent, Saikosaponin-d (SSd), for CRPC therapy based on its mechanism of action. DU145 and CWR22Rv1 cells representing CRPC were employed in this study. A series of cell, biochemical, and molecular biologic assays such as Immunofluorescence, Zymography, Sphere formation, Colony formation, and MTT were used. Finally, we find SSd can significantly inhibit the growth of PCa cells in both dose- and time-dependent and suppress the colony formation during a long-term drug administration, it also can inhibit their migration and invasion abilities, which was accompanied by reverse the epithelial-mesenchymal transition (EMT) and suppress MMP2/9 expression as well as activities. Furthermore, SSd can suppress cancer stem cell (CSC) phenotypes such as self-renewal ability. Mechanistically, SSd blocks Wnt/β-catenin signaling pathway by decreasing GSK3β phosphorylation to affect EMT and CSC. These findings demonstrate the mechanism of anti-cancer activity of SSd in targeting EMT and CSC, suggesting SSd can be a potent agent for CRPC therapy. PMID:27155154

  11. Collateral sensitivity to cisplatin in KB-8-5-11 drug-resistant cancer cells.

    LENUS (Irish Health Repository)

    Doherty, Ben

    2014-01-01

    KB-8-5-11 cells are a drug-resistant cervical cell model that overexpresses ABCB1 (P-glycoprotein). KB-8-5-11 has become sensitive to non-ABCB1 substrate cisplatin. Understanding the mechanism of collateral sensitivity to cisplatin may lead to biomarker discovery for platinum sensitivity in patients with cancer.

  12. FoxM1 mediated resistance to gefitinib in non-small-cell lung cancer cells

    Institute of Scientific and Technical Information of China (English)

    Nuo XU; Xin ZHANG; Xun WANG; Hai-yan GE; Xiao-ying WANG; David GARFIELD; Ping YANG; Yuan-lin SONG; Chun-xue BAI

    2012-01-01

    Gefitinib is effective in only approximately 20% of patients with non-small-cell lung cancer (NSCLC),and the underlying mechanism remains unclear.FoxM1 is upregulated in NSCLC and associated with a poor prognosis in NSCLC patients.In this study,we examined the possible role of FoxM1 in gefitinib resistance and the related mechanisms.Methods:Gefitinib resistant human lung adenocarcinoma cell line SPC-A-1 and gefitinib-sensitive human lung mucoepidermoid carcinoma cell line NCI-H292 were used.mRNA and protein expression of FoxM1 and other factors were tested with quantitative RT PCR and Western blot analysis.RNA interference was performed to suppress FoxM1 expression in SPC-A-1 cells,and lentiviral infection was used to overexpress FoxM1 in H292 cells.MTT assay and flow cytometry were used to examine the proliferation and apoptosis of the cells.Results:Treatment of SPC-A-1 cells with gefitinib (1 and 10 μmol/L) upregulated the expression of FoxM1 in time- and concentrationdependent manners,while gefrtinib (1 μmol/L) downregulated in H292 cells.In SPC-A-1 cells treated with gefitinib (1 μmol/L),the expression of several downstream targets of FoxM1,including survivin,cyclin B1,SKP2,PLK1,Aurora B kinase and CDC25B,were significantly upregulated.Overexpression of FoxM1 increased the resistance in H292 cells,while attenuated FoxM1 expression restored the sensitivity to gefitinib in SPC-A-1 cells by inhibiting proliferation and inducing apoptosis.Conclusion:The results suggest that FoxM1 plays an important role in the resistance of NSCLC cells to gefitinib in vitro.FoxM1 could be used as a therapeutic target to overcome the resistance to gefitinib.

  13. The role of RAD51 in etoposide (VP16) resistance in small cell lung cancer

    DEFF Research Database (Denmark)

    Hansen, Lasse Tengbjerg; Lundin, Cecilia; Spang-Thomsen, Mogens;

    2003-01-01

    investigated DSB repair and cellular VP16 sensitivity of SCLC cells. VP16 sensitivity and RAD51, DNA-PK(cs), topoisomerase IIalpha and P-glycoprotein protein levels were determined in 17 SCLC cell lines. In order to unravel the role of RAD51 in VP16 resistance, we cloned the human RAD51 gene, transfected SCLC......Etoposide (VP16) is a potent inducer of DNA double-strand breaks (DSBs) and is efficiently used in small cell lung cancer (SCLC) therapy. However, acquired VP16 resistance remains an important barrier to effective treatment. To understand the underlying mechanisms for VP16 resistance in SCLC, we...

  14. Resistance to paclitaxel in a cisplatin-resistant ovarian cancer cell line is mediated by P-glycoprotein.

    Directory of Open Access Journals (Sweden)

    Britta Stordal

    Full Text Available The IGROVCDDP cisplatin-resistant ovarian cancer cell line is also resistant to paclitaxel and models the resistance phenotype of relapsed ovarian cancer patients after first-line platinum/taxane chemotherapy. A TaqMan low-density array (TLDA was used to characterise the expression of 380 genes associated with chemotherapy resistance in IGROVCDDP cells. Paclitaxel resistance in IGROVCDDP is mediated by gene and protein overexpression of P-glycoprotein and the protein is functionally active. Cisplatin resistance was not reversed by elacridar, confirming that cisplatin is not a P-glycoprotein substrate. Cisplatin resistance in IGROVCDDP is multifactorial and is mediated in part by the glutathione pathway and decreased accumulation of drug. Total cellular glutathione was not increased. However, the enzyme activity of GSR and GGT1 were up-regulated. The cellular localisation of copper transporter CTR1 changed from membrane associated in IGROV-1 to cytoplasmic in IGROVCDDP. This may mediate the previously reported accumulation defect. There was decreased expression of the sodium potassium pump (ATP1A, MRP1 and FBP which all have been previously associated with platinum accumulation defects in platinum-resistant cell lines. Cellular localisation of MRP1 was also altered in IGROVCDDP shifting basolaterally, compared to IGROV-1. BRCA1 was also up-regulated at the gene and protein level. The overexpression of P-glycoprotein in a resistant model developed with cisplatin is unusual. This demonstrates that P-glycoprotein can be up-regulated as a generalised stress response rather than as a specific response to a substrate. Mechanisms characterised in IGROVCDDP cells may be applicable to relapsed ovarian cancer patients treated with frontline platinum/taxane chemotherapy.

  15. Intercellular interactions and progression of hormonal resistance of breast cancer cells

    Directory of Open Access Journals (Sweden)

    S. E. Semina

    2015-01-01

    Full Text Available The main goal of the study is the analysis of the role of cell-cell interactions in the formation of the tumor cell resistance to hormonal drugs. About 70 % of breast tumors contain estrogen receptor (ER, a key molecular target for hormone (endocrine therapy. However, the efficiency of endocrine therapy of breast cancer is limited by the development of hormone resistance which leads to progression of tumor cells to hormone-independent phenotype, increase in tumor malignancy and worse prognosis. Hormonal independence may be accompanied with the loss of the receptors, as well as with the another mechanisms including ligand-independent receptor activation, disbalance between receptor activators and repressors, stimulation of hormone-independent pathways. It is less known about the role of the intercellular interactions in the progression of hormonal resistance. Several studies demonstrate the involvement of cell junctions in the mediating of cell response to (anti estrogens, however the significance of cell-cell contacts in the formation of hormonal resistance still not clear. Here we have hypothesized that the formation of the hormone resistance of tumors may be based, at least in part, on the transferring of the resistant phenotype from the resistant to hormone-sensitive cells – as a result of the secretion of the specific factors acting in the paracrine manner or via the direct cell-cell contacts. Using the estrogen-dependent breast cancer cells MCF-7 and the resistant subline MCF-7 / T developed by long-term cultivation of MCF-7 cells in the presence of antiestrogen tamoxifen, we investigated the possible changes in the hormonal sensitivity of these cells caused by the co-cultivation in vitro. To discern the cell cultures, the MCF-7 / T cells were previously transfected with the plasmid containing the gene of the green fluorescent protein (GFP, and GFP-positive hormone-resistant subline MCF-7 / T / GFP+ was developed. We showed that the co

  16. Overcoming doxorubicin resistance of cancer cells by Cas9-mediated gene disruption

    OpenAIRE

    Jong Seong Ha; Juyoung Byun; Dae-Ro Ahn

    2016-01-01

    In this study, Cas9 system was employed to down-regulate mdr1 gene for overcoming multidrug resistance of cancer cells. Disruption of the MDR1 gene was achieved by delivery of the Cas9-sgRNA plasmid or the Cas9-sgRNA ribonucleoprotein complex using a conventional gene transfection agent and protein transduction domain (PTD). Doxorubicin showed considerable cytotoxicity to the drug-resistant breast cancer cells pre-treated with the RNA-guided endonuclease (RGEN) systems, whereas virtually non-...

  17. Increased Expression of Several Collagen Genes is Associated with Drug Resistance in Ovarian Cancer Cell Lines.

    Science.gov (United States)

    Januchowski, Radosław; Świerczewska, Monika; Sterzyńska, Karolina; Wojtowicz, Karolina; Nowicki, Michał; Zabel, Maciej

    2016-01-01

    Ovarian cancer is the most lethal gynaecological cancer. The main reason for the high mortality among ovarian cancer patients is the development of drug resistance. The expression of collagen genes by cancer cells can increase drug resistance by inhibiting the penetration of the drug into the cancer tissue as well as increase apoptosis resistance. In this study, we present data that shows differential expression levels of collagen genes and proteins in cisplatin- (CIS), paclitaxel- (PAC), doxorubicin- (DOX), topotecan- (TOP), vincristine- (VIN) and methotrexate- (MTX) resistant ovarian cancer cell lines. Quantitative real-time polymerase chain reactions were performed to determine the mRNA levels. Protein expression was detected using Western blot and immunocytochemistry assays. In the drug resistant cell lines, we observed the upregulation of eight collagen genes at the mRNA level and based on these expression levels, we divided the collagen genes into the following three groups: 1. Genes with less than a 50-fold increase in expression: COL1A1, COL5A2, COL12A1 and COL17A1. 2. Genes with greater than a 50-fold increase in expression: COL1A2, COL15A1 and COL21A1. 3. Gene with a very high level of expression: COL3A1. Expression of collagen (COL) proteins from groups 2 and 3 were also confirmed using immunocytochemistry. Western blot analysis showed very high expression levels of COL3A1 protein, and immunocytochemistry analysis showed the presence of extracellular COL3A1 in the W1TR cell line. The cells mainly responsible for the extracellular COL3A1 production are aldehyde dehydrogenase-1A1 (ALDH1A1) positive cells. All correlations between the types of cytostatic drugs and the expression levels of different COL genes were studied, and our results suggest that the expression of fibrillar collagens may be involved in the TOP and PAC resistance of the ovarian cancer cells. The expression pattern of COL genes provide a preliminary view into the role of these proteins in

  18. Resistance of colorectal cancer cells to radiation and 5-FU is associated with MELK expression

    International Nuclear Information System (INIS)

    Highlights: → MELK expression significantly increased when the cells are exposed to radiation or 5-FU. → Suppression of MELK caused cell cycle changes and decrease in proliferation. → Radiation or 5-FU treatment after MELK suppression by siRNA induced growth inhibition. -- Abstract: It was reported that the local recurrence would be caused by cancer stem cells acquiring chemo- and radio-resistance. Recently, one of the potential therapeutic targets for colorectal and other cancers has been identified, which is maternal embryonic leucine zipper kinase (MELK). MELK is known as an embryonic and neural stem cell marker, and associated with the cell survival, cell proliferation, and apoptosis. In this study, SNU-503, which is a rectal cancer cell line, was treated with radiation or 5-fluorouracil (5-FU), and elevation of the MELK expression level was observed. Furthermore, the cell line was pre-treated with small interfering RNA (siRNA) against MELK mRNA before treatment of radiation or 5-FU and its effects on cell cycle and proliferation were observed. We demonstrated that knockdown of MELK reduced the proliferation of cells with radiation or 5-FU treatment. In addition, MELK suppression caused changes in cell cycle. In conclusion, MELK could be associated with increased resistance of colorectal cancer cells against radiation and 5-FU.

  19. Uncovering Scaling Laws to Infer Multidrug Response of Resistant Microbes and Cancer Cells

    Directory of Open Access Journals (Sweden)

    Kevin B. Wood

    2014-03-01

    Full Text Available Drug resistance in bacterial infections and cancers constitutes a major threat to human health. Treatments often include several interacting drugs, but even potent therapies can become ineffective in resistant mutants. Here, we simplify the picture of drug resistance by identifying scaling laws that unify the multidrug responses of drug-sensitive and -resistant cells. On the basis of these scaling relationships, we are able to infer the two-drug response of resistant mutants in previously unsampled regions of dosage space in clinically relevant microbes such as E. coli, E. faecalis, S. aureus, and S. cerevisiae as well as human non-small-cell lung cancer, melanoma, and breast cancer stem cells. Importantly, we find that scaling relations also apply across evolutionarily close strains. Finally, scaling allows one to rapidly identify new drug combinations and predict potent dosage regimes for targeting resistant mutants without any prior mechanistic knowledge about the specific resistance mechanism.

  20. Enhanced expression of DNA polymerase eta contributes to cisplatin resistance of ovarian cancer stem cells

    OpenAIRE

    Srivastava, Amit Kumar; Han, Chunhua; Zhao, Ran; Cui, Tiantian; Dai, Yuntao; Mao, Charlene; Zhao, Weiqiang; Zhang, Xiaoli; Yu, Jianhua; Wang, Qi-En

    2015-01-01

    Cancer stem cells (CSCs) exhibit enhanced chemo/radiotherapy resistance, and their survival following cancer treatment is believed to be responsible for tumor recurrence and metastasis. Thus, understanding the mechanisms through which CSCs survive conventional chemotherapy is essential for identification of new therapeutic strategies to prevent tumor relapse. Our findings that ovarian CSCs survive cisplatin treatment through elevated expression of polymerase η represent an opportunity to erad...

  1. Lysophosphatidate induces chemo-resistance by releasing breast cancer cells from taxol-induced mitotic arrest.

    Directory of Open Access Journals (Sweden)

    Nasser Samadi

    Full Text Available BACKGROUND: Taxol is a microtubule stabilizing agent that arrests cells in mitosis leading to cell death. Taxol is widely used to treat breast cancer, but resistance occurs in 25-69% of patients and it is vital to understand how Taxol resistance develops to improve chemotherapy. The effects of chemotherapeutic agents are overcome by survival signals that cancer cells receive. We focused our studies on autotaxin, which is a secreted protein that increases tumor growth, aggressiveness, angiogenesis and metastasis. We discovered that autotaxin strongly antagonizes the Taxol-induced killing of breast cancer and melanoma cells by converting the abundant extra-cellular lipid, lysophosphatidylcholine, into lysophosphatidate. This lipid stimulates specific G-protein coupled receptors that activate survival signals. METHODOLOGY/PRINCIPAL FINDINGS: In this study we determined the basis of these antagonistic actions of lysophosphatidate towards Taxol-induced G2/M arrest and cell death using cultured breast cancer cells. Lysophosphatidate does not antagonize Taxol action in MCF-7 cells by increasing Taxol metabolism or its expulsion through multi-drug resistance transporters. Lysophosphatidate does not lower the percentage of cells accumulating in G2/M by decreasing exit from S-phase or selective stimulation of cell death in G2/M. Instead, LPA had an unexpected and remarkable action in enabling MCF-7 and MDA-MB-468 cells, which had been arrested in G2/M by Taxol, to normalize spindle structure and divide, thus avoiding cell death. This action involves displacement of Taxol from the tubulin polymer fraction, which based on inhibitor studies, depends on activation of LPA receptors and phosphatidylinositol 3-kinase. CONCLUSIONS/SIGNIFICANCE: This work demonstrates a previously unknown consequence of lysophosphatidate action that explains why autotaxin and lysophosphatidate protect against Taxol-induced cell death and promote resistance to the action of this

  2. The contribution of drug resistant cancer stem cells to paediatric brain tumours

    OpenAIRE

    Punjaruk, Wiyada

    2010-01-01

    Introduction: Recent studies have revealed that cancer stem cells (CSCs) exist in malignant disease. Additionally, it is proposed that these cells may survive following chemotherapy, and hence contribute to tumour relapse. A significant mechanism of drug resistance in CSCs is believed to be the expression of ATP-binding cassette (ABC) transporters that efflux cytotoxic agents out of cells. The objective of this study was to study the existence of CSCs in a panel of primary paediatric brain tu...

  3. Nanodrug Formed by Coassembly of Dual Anticancer Drugs to Inhibit Cancer Cell Drug Resistance.

    Science.gov (United States)

    Zhao, Yuanyuan; Chen, Fei; Pan, Yuanming; Li, Zhipeng; Xue, Xiangdong; Okeke, Chukwunweike Ikechukwu; Wang, Yifeng; Li, Chan; Peng, Ling; Wang, Paul C; Ma, Xiaowei; Liang, Xing-Jie

    2015-09-01

    Carrier-free pure nanodrugs (PNDs) that are composed entirely of pharmaceutically active molecules are regarded as promising candidates to be the next generation of drug formulations and are mainly formulated from supramolecular self-assembly of drug molecules. It benefits from the efficient use of drug compounds with poor aqueous solubility and takes advantage of nanoscale drug delivery systems. Here, a type of all-in-one nanoparticle consisting of multiple drugs with enhanced synergistic antiproliferation efficiency against drug-resistant cancer cells has been created. To nanoparticulate the anticancer drugs, 10-hydroxycamptothecin (HCPT) and doxorubicin (DOX) were chosen as a typical model. The resulting HD nanoparticles (HD NPs) were formulated by a "green" and convenient self-assembling method, and the water-solubility of 10-hydroxycamptothecin (HCPT) was improved 50-fold after nanosizing by coassembly with DOX. The formation process was studied by observing the morphological changes at various reaction times and molar ratios of DOX to HCPT. Molecular dynamics (MD) simulations showed that DOX molecules tend to assemble around HCPT molecules through intermolecular forces. With the advantage of nanosizing, HD NPs could improve the intracellular drug retention of DOX to as much as 2-fold in drug-resistant cancer cells (MCF-7R). As a dual-drug-loaded nanoformulation, HD NPs effectively enhanced drug cytotoxicity to drug-resistant cancer cells. The combination of HCPT and DOX exhibited a synergistic effect as the nanosized HD NPs improved drug retention in drug-resistant cancer cells against P-gp efflux in MCF-7R cells. Furthermore, colony forming assays were applied to evaluate long-term inhibition of cancer cell proliferation, and these assays confirmed the greatly improved cytotoxicity of HD NPs in drug-resistant cells compared to free drugs. PMID:26270258

  4. ABCC3 as a marker for multidrug resistance in non-small cell lung cancer

    OpenAIRE

    Yanbin Zhao; Hailing Lu; An Yan; Yanmei Yang; Qingwei Meng; Lichun Sun; Hui Pang; Chunhong Li; Xiaoqun Dong; Li Cai

    2013-01-01

    Multidrug resistance (MDR) contributes to the failure of chemotherapy and high mortality in non-small cell lung cancer (NSCLC). We aim to identify MDR genes that predict tumor response to chemotherapy. 199 NSCLC fresh tissue samples were tested for chemosensitivity by MTT assay. cDNA microarray was done with 5 samples with highest resistance and 6 samples with highest sensitivity. Expression of ABCC3 mRNA and protein was detected by real-time PCR and immunohistochemisty, respectively. The ass...

  5. Increased Mitochondrial DNA Induces Acquired Docetaxel Resistance in Head and Neck Cancer Cells

    Science.gov (United States)

    Mizumachi, T; Suzuki, S; Naito, A; Carcel-Trullols, J; Evans, TT; Spring, PM; Oridate, N; Furuta, Y; Fukuda, S; Higuchi, M

    2008-01-01

    Docetaxel is one of the most effective chemotherapeutic agents against cancer; nevertheless, some patients develop resistance. Unfortunately, their causes and mechanisms remain unknown. We created docetaxel-resistant DRHEp2 from human laryngeal cancer HEp2 and investigated the roles of mitochondrial DNA (mtDNA) and ROS on docetaxel resistance. DRHEp2 had greatly increased mtDNA content. Reduction of mtDNA content in DRHEp2 by ethidium bromide treatment reduced the resistance. These results indicate the possible roles of mtDNA-coded enzymes in mitochondrial respiratory chain (MRC) in resistant mechanisms. Oligomycin A, an Fo-ATPase inhibitor, eliminated docetaxel resistance in DRHEp2. In contrast, inhibitors of other MRC did not. RNA interference targeted to Fo-ATPase d-subunit restored docetaxel-induced cytotoxicity to DRHEp2. These results indicate the roles of Fo-ATPase for resistant mechanisms. Docetaxel induced ROS generation in HEp2 but not in DRHEp2 and antioxidant pyrrolidine dithiocarbamate eliminated docetaxel-induced cytotoxicity, suggesting roles of ROS in docetaxel-induced cell death. Furthermore, inhibition of Fo-ATPase by Oligomycin A induced docetaxel–mediated ROS generation in DRHEp2. Taken together, DRHEp2 acquired docetaxel resistance through increasing Fo-ATPase, which led to diminish docetaxel-induced ROS generation and subsequently inhibited cell death. In conclusion, mtDNA plays an important role in developing docetaxel resistance through the reduction of ROS generation by regulating Fo-ATPase. PMID:17637738

  6. Mesenchymal Stem Cell-Induced Doxorubicin Resistance in Triple Negative Breast Cancer

    Directory of Open Access Journals (Sweden)

    Dar-Ren Chen

    2014-01-01

    Full Text Available Triple negative breast cancer (TNBC is an aggressive histological subtype with limited treatment options and a worse clinical outcome compared with other breast cancer subtypes. Doxorubicin is considered to be one of the most effective agents in the treatment of TNBC. Unfortunately, resistance to this agent is common. In some drug-resistant cells, drug efflux is mediated by adenosine triphosphate-dependent membrane transporter termed adenosine triphosphate-binding cassette (ABC transporter, which can drive the substrates across membranes against concentration gradient. In the tumor microenvironment, upon interaction with mesenchymal stem cells (MSCs, tumor cells exhibit altered biological functions of certain gene clusters, hence increasing stemness of tumor cells, migration ability, angiogenesis, and drug resistance. In our present study, we investigated the mechanism of TNBC drug resistance induced by adipose-derived MSCs. Upon exposure of TNBC to MSC-secreted conditioned medium (CM, noticeable drug resistance against doxorubicin with markedly increased BCRP protein expression was observed. Intracellular doxorubicin accumulation of TNBC was also decreased by MSC-secreted CM. Furthermore, we found that doxorubicin resistance of TNBC was mediated by IL-8 presented in the MSC-secreted CM. These findings may enrich the list of potential targets for overcoming drug resistance induced by MSCs in TNBC patients.

  7. LAMP3 is involved in tamoxifen resistance in breast cancer cells through the modulation of autophagy

    NARCIS (Netherlands)

    Nagelkerke, A.P.; Sieuwerts, A.M.; Bussink, J.; Sweep, F.C.; Look, M.P.; Foekens, J.A.; Martens, J.W.; Span, P.N.

    2014-01-01

    Lysosome-associated membrane protein 3 (LAMP3) is a member of the LAMP-family of proteins, which are involved in the process of autophagy. Autophagy is induced by tamoxifen in breast cancer cells and may contribute to tamoxifen resistance. In this study, the significance of LAMP3 for tamoxifen resis

  8. LAMP3 is involved in tamoxifen resistance in breast cancer cells through the modulation of autophagy

    NARCIS (Netherlands)

    A. Nagelkerke (Anika); A.M. Sieuwerts (Anieta); J. Bussink (Johan); F.C. Sweep (Fred); M.P. Look (Maxime); J.A. Foekens (John); J.W.M. Martens (John); P.N. Span (Paul)

    2014-01-01

    textabstractLysosome-associated membrane protein 3 (LAMP3) is a member of the LAMP-family of proteins, which are involved in the process of autophagy. Autophagy is induced by tamoxifen in breast cancer cells and may contribute to tamoxifen resistance. In this study, the significance of LAMP3 for tam

  9. Establishment of a human colorectal cancer cell line P6C with stem cell properties and resistance to chemotherapeutic drugs

    Institute of Scientific and Technical Information of China (English)

    Guan-hua RAO; Hong-min LIU; Bao-wei LI; Jia-jie HAO; Yan-lei YANG; Ming-rong WANG; Xiao-hui WANG

    2013-01-01

    Aim:Cancer stem cells have the capacity to initiate and sustain tumor growth.In this study,we established a CD44+ colorectal cancer stem cell line with particular emphasis on its self-renewal capacity,enhanced tumor initiation and drug resistance.Methods:Fresh colon cancer and paired normal colon tissues were collected from 13 patients who had not received chemotherapy or radiotherapy prior to surgery.Among the 6 single-cell derived clones,only the P6C cell line was cultured for more than 20 passages in serial culture and formed holoclones with high efficiency,and then the stemness gene expression,colony formation,tumorigenicity and drug sensitivities of the P6C cell line were examined.Results:Stemness proteins,including c-Myc,0ct3/4,Nanog,Lgr5,and SOX2,were highly expressed in the P6C cell line.Oct3/4-positive P6C cells mostly generated holoclones through symmetric division,while a small number of P6C cells generated meroclones through asymmetric division.P6C cells stably expressed CD44 and possessed a high capacity to form tumor spheres.A single cellderived sphere was capable of generating xenograft tumors in nude mice.Compared to SW480 and HCT116 colorectal cancer cells,P6C cells were highly resistant to Camptothecin and 5-fluorouracil,the commonly used chemotherapeutic agents to treat colorectal cancers.Conclusion:We established a colorectal cancer stem cell line P6C with a high tumorigenic capacity and the characteristics of normal stem cells.It will benefit the mechanistic studies on cancer stem cells and the development of drugs that specifically target the cancer stem cells.

  10. Increased p38-MAPK is responsible for chemotherapy resistance in human gastric cancer cells

    International Nuclear Information System (INIS)

    Chemoresistance is one of the main obstacles to successful cancer therapy and is frequently associated with Multidrug resistance (MDR). Many different mechanisms have been suggested to explain the development of an MDR phenotype in cancer cells. One of the most studied mechanisms is the overexpression of P-glycoprotein (P-gp), which is a product of the MDR1 gene. Tumor cells often acquire the drug-resistance phenotype due to upregulation of the MDR1 gene. Overexpression of MDR1 gene has often been reported in primary gastric adenocarcinoma. This study investigated the role of p38-MAPK signal pathway in vincristine-resistant SGC7901/VCR cells. P-gp and MDR1 RNA were detected by Western blot analysis and RT-PCR amplification. Mitgen-activated protein kinases and function of P-gp were demonstrated by Western blot and FACS Aria cytometer analysis. Ap-1 activity and cell apoptosis were detected by Dual-Luciferase Reporter Assay and annexin V-PI dual staining. The vincristine-resistant SGC7901/VCR cells with increased expression of the multidrug-resistance 1 (MDR1) gene were resistant to P-gp-related drug and P-gp-unrelated drugs. Constitutive increases of phosphorylated p38-MAPK and AP-1 activities were also found in the drug-resistant cells. Inhibition of p38-MAPK by SB202190 reduced activator protein-1 (AP-1) activity and MDR1 expression levels and increased the sensitivity of SGC7901/VCR cells to chemotherapy. Activation of the p38-MAPK pathway might be responsible for the modulation of P-glycoprotein-mediated and P-glycoprotein-unmediated multidrug resistance in the SGC7901/VCR cell line

  11. Phosphoproteome and Transcriptome of RA-Responsive and RA-Resistant Breast Cancer Cell Lines

    Science.gov (United States)

    Carrier, Marilyn; Joint, Mathilde; Lutzing, Régis; Page, Adeline; Rochette-Egly, Cécile

    2016-01-01

    Retinoic acid (RA), the main active vitamin A metabolite, controls multiple biological processes such as cell proliferation and differentiation through genomic programs and kinase cascades activation. Due to these properties, RA has proven anti-cancer capacity. Several breast cancer cells respond to the antiproliferative effects of RA, while others are RA-resistant. However, the overall signaling and transcriptional pathways that are altered in such cells have not been elucidated. Here, in a large-scale analysis of the phosphoproteins and in a genome-wide analysis of the RA-regulated genes, we compared two human breast cancer cell lines, a RA-responsive one, the MCF7 cell line, and a RA-resistant one, the BT474 cell line, which depicts several alterations of the “kinome”. Using high-resolution nano-LC-LTQ-Orbitrap mass spectrometry associated to phosphopeptide enrichment, we found that several proteins involved in signaling and in transcription, are differentially phosphorylated before and after RA addition. The paradigm of these proteins is the RA receptor α (RARα), which was phosphorylated in MCF7 cells but not in BT474 cells after RA addition. The panel of the RA-regulated genes was also different. Overall our results indicate that RA resistance might correlate with the deregulation of the phosphoproteome with consequences on gene expression. PMID:27362937

  12. Suppression of Poly(rC)-Binding Protein 4 (PCBP4) reduced cisplatin resistance in human maxillary cancer cells

    Science.gov (United States)

    Ito, Yumi; Narita, Norihiko; Nomi, Nozomi; Sugimoto, Chizuru; Takabayashi, Tetsuji; Yamada, Takechiyo; Karaya, Kazuhiro; Matsumoto, Hideki; Fujieda, Shigeharu

    2015-01-01

    Cisplatin plays an important role in the therapy for human head and neck cancers. However, cancer cells develop cisplatin resistance, leading to difficulty in treatment and poor prognosis. To analyze cisplatin-resistant mechanisms, a cisplatin-resistant cell line, IMC-3CR, was established from the IMC-3 human maxillary cancer cell line. Flow cytometry revealed that, compared with IMC-3 cells, cisplatin more dominantly induced cell cycle G2/M arrest rather than apoptosis in IMC-3CR cells. That fact suggests that IMC-3CR cells avoid cisplatin-induced apoptosis through induction of G2/M arrest, which allows cancer cells to repair damaged DNA and survive. In the present study, we specifically examined Poly(rC)-Binding Protein 4 (PCBP4), which reportedly induces G2/M arrest. Results showed that suppression of PCBP4 by RNAi reduced cisplatin-induced G2/M arrest and enhanced apoptosis in IMC-3CR cells, resulting in the reduction of cisplatin resistance. In contrast, overexpression of PCBP4 in IMC-3 cells induced G2/M arrest after cisplatin treatment and enhanced cisplatin resistance. We revealed that PCBP4 combined with Cdc25A and suppressed the expression of Cdc25A, resulting in G2/M arrest. PCBP4 plays important roles in the induction of cisplatin resistance in human maxillary cancers. PCBP4 is a novel molecular target for the therapy of head and neck cancers, especially cisplatin-resistant cancers. PMID:26196957

  13. Involvement of Notch-1 in Resistance to Regorafenib in Colon Cancer Cells.

    Science.gov (United States)

    Mirone, Giovanna; Perna, Stefania; Shukla, Arvind; Marfe, Gabriella

    2016-05-01

    Regorafenib, an oral small-molecule multi kinase inhibitor, is able to block Vascular Endothelial Growth Factor Receptors (VEGFR-1, 2, and 3), Platelet-Derived Growth Factor Receptors (PDGF), Fibroblast Growth Factor (FGF) receptor 1, Raf, TIE-2, and the kinases KIT, RET, and BRAF. Different studies have displayed its antitumor activity in several cancer models (both in vitro and in vivo), particularly in colorectal and gastrointestinal stromal cancers. The mechanism of resistance to regorafenib is largely unknown. In our investigation, we have generated regorafenib-resistant SW480 cells (Reg-R-SW480 cells) by culturing such cells with increasing concentration of regorafenib. Examination of intracellular signaling found that Akt signaling was activated in Reg-R-SW480 cells but not in wild-type SW480 cells, after regorafenib treatment as measured by Western Blot. The Notch pathway is a fundamental signaling system in the development and homeostasis of tissues since it regulates different cellular process such as proliferation, differentiation, and apoptosis and it can be a potential driver of resistance to a wide array of targeted therapies. In this study, we found that Notch-1 was significantly up-regulated in resistant tumor cells as well as HES1 and HEY. Additionally, inhibition of Notch-1 in resistant cells partially restored sensitivity to regorafenib treatment in vitro. Collectively, these data suggest a key role of Notch-1 in mediating the resistant effects of regorafenib in colorectal cancer cells, and also provide a rationale to improve the therapeutic efficacy of regorafenib. PMID:26419617

  14. Label-free recognition of drug resistance via impedimetric screening of breast cancer cells.

    Directory of Open Access Journals (Sweden)

    Bilge Eker

    Full Text Available We present a novel study on label-free recognition and distinction of drug resistant breast cancer cells (MCF-7 DOX from their parental cells (MCF-7 WT via impedimetric measurements. Drug resistant cells exhibited significant differences in their dielectric properties compared to wild-type cells, exerting much higher extracellular resistance (Rextra . Immunostaining revealed that MCF-7 DOX cells gained a much denser F-actin network upon acquiring drug resistance indicating that remodeling of actin cytoskeleton is probably the reason behind higher Rextra , providing stronger cell architecture. Moreover, having exposed both cell types to doxorubicin, we were able to distinguish these two phenotypes based on their substantially different drug response. Interestingly, impedimetric measurements identified a concentration-dependent and reversible increase in cell stiffness in the presence of low non-lethal drug doses. Combined with a profound frequency analysis, these findings enabled distinguishing distinct cellular responses during drug exposure within four concentration ranges without using any labeling. Overall, this study highlights the possibility to differentiate drug resistant phenotypes from their parental cells and to assess their drug response by using microelectrodes, offering direct, real-time and noninvasive measurements of cell dependent parameters under drug exposure, hence providing a promising step for personalized medicine applications such as evaluation of the disease progress and optimization of the drug treatment of a patient during chemotherapy.

  15. Overcoming Resistance of Cancer Cells to PARP-1 Inhibitors with Three Different Drug Combinations.

    Directory of Open Access Journals (Sweden)

    Michal Yalon

    Full Text Available Inhibitors of poly[ADP-ribose] polymerase 1 (PARPis show promise for treatment of cancers which lack capacity for homologous recombination repair (HRR. However, new therapeutic strategies are required in order to overcome innate and acquired resistance to these drugs and thus expand the array of cancers that could benefit from them. We show that human cancer cell lines which respond poorly to ABT-888 (a PARPi, become sensitive to it when co-treated with vorinostat (a histone deacetylase inhibitor (HDACi. Vorinostat also sensitized PARPis insensitive cancer cell lines to 6-thioguanine (6-TG-a drug that targets PARPis sensitive cells. The sensitizing effect of vorinostat was associated with increased phosphorylation of eukaryotic initiation factor (eIF 2α which in and of itself increases the sensitivity of cancer cells to ABT-888. Importantly, these drug combinations did not affect survival of normal fibroblasts and breast cells, and significantly increased the inhibition of xenograft tumor growth relative to each drug alone, without affecting the mice weight or their liver and kidney function. Our results show that combination of vorinostat and ABT-888 could potentially prove useful for treatment of cancer with innate resistance to PARPis due to active HRR machinery, while the combination of vorinostat and 6-TG could potentially overcome innate or acquired resistance to PARPis due to secondary or reversal BRCA mutations, to decreased PARP-1 level or to increased expression of multiple drug resistant proteins. Importantly, drugs which increase phosphorylation of eIF2α may mimic the sensitizing effect of vorinostat on cellular response to PARPis or to 6-TG, without activating all of its downstream effectors.

  16. Targeting the sphingolipid metabolism to defeat pancreatic cancer cell resistance to the chemotherapeutic gemcitabine drug.

    Science.gov (United States)

    Guillermet-Guibert, Julie; Davenne, Lise; Pchejetski, Dimitri; Saint-Laurent, Nathalie; Brizuela, Leyre; Guilbeau-Frugier, Céline; Delisle, Marie-Bernadette; Cuvillier, Olivier; Susini, Christiane; Bousquet, Corinne

    2009-04-01

    Defeating pancreatic cancer resistance to the chemotherapeutic drug gemcitabine remains a challenge to treat this deadly cancer. Targeting the sphingolipid metabolism for improving tumor chemosensitivity has recently emerged as a promising strategy. The fine balance between intracellular levels of the prosurvival sphingosine-1-phosphate (S1P) and the proapoptotic ceramide sphingolipids determines cell fate. Among enzymes that control this metabolism, sphingosine kinase-1 (SphK1), a tumor-associated protein overexpressed in many cancers, favors survival through S1P production, and inhibitors of SphK1 are used in ongoing clinical trials to sensitize epithelial ovarian and prostate cancer cells to various chemotherapeutic drugs. We here report that the cellular ceramide/S1P ratio is a critical biosensor for predicting pancreatic cancer cell sensitivity to gemcitabine. A low level of the ceramide/S1P ratio, associated with a high SphK1 activity, correlates with a robust intrinsic pancreatic cancer cell chemoresistance toward gemcitabine. Strikingly, increasing the ceramide/S1P ratio, by using pharmacologic (SphK1 inhibitor or ceramide analogue) or small interfering RNA-based approaches to up-regulate intracellular ceramide levels or reduce SphK1 activity, sensitized pancreatic cancer cells to gemcitabine. Conversely, decreasing the ceramide/S1P ratio, by up-regulating SphK1 activity, promoted gemcitabine resistance in these cells. Development of novel pharmacologic strategies targeting the sphingolipid metabolism might therefore represent an interesting promising approach, when combined with gemcitabine, to defeat pancreatic cancer chemoresistance to this drug. PMID:19372554

  17. Triclosan potentiates epithelial-to-mesenchymal transition in anoikis-resistant human lung cancer cells.

    Science.gov (United States)

    Winitthana, Thidarat; Lawanprasert, Somsong; Chanvorachote, Pithi

    2014-01-01

    Alteration of cancer cell toward mesenchymal phenotype has been shown to potentiate tumor aggressiveness by increasing cancer cell metastasis. Herein, we report the effect of triclosan, a widely used antibacterial agent found in many daily products, in enhancing the epithelial-to-mesenchymal transition (EMT) in aggressive anoikis resistant human H460 lung cancer cells. EMT has been long known to increase abilities of the cells to increase migration, invasion, and survival in circulating system. The present study reveals that treatment of the cancer cells with triclosan at the physiologically related concentrations significantly increased the colony number of the cancer cells assessed by tumor formation assay. Also, the mesenchymal-like morphology and decrease in cell-to-cell adhesion were observed in triclosan-treated cells. Importantly, western blot analysis revealed that triclosan-treated cells exhibited decreased E-cadherin, while the levels of EMT markers, namely N-cadherin, vimentin, snail and slug were found to be significantly up-regulated. Furthermore, EMT induced by triclosan treatment was accompanied by the activation of focal adhesion kinase/ATP dependent tyrosine kinase (FAK/Akt) and Ras-related C3 botulinum toxin substrate 1 (Rac1), which enhanced the ability of the cells to migrate and invade. In conclusion, we demonstrated for the first time that triclosan may potentiate cancer cells survival in detached condition and motility via the process of EMT. As mentioned capabilities are required for success in metastasis, the present study provides the novel toxicological information and encourages the awareness of triclosan use in cancer patients. PMID:25329306

  18. Triclosan potentiates epithelial-to-mesenchymal transition in anoikis-resistant human lung cancer cells.

    Directory of Open Access Journals (Sweden)

    Thidarat Winitthana

    Full Text Available Alteration of cancer cell toward mesenchymal phenotype has been shown to potentiate tumor aggressiveness by increasing cancer cell metastasis. Herein, we report the effect of triclosan, a widely used antibacterial agent found in many daily products, in enhancing the epithelial-to-mesenchymal transition (EMT in aggressive anoikis resistant human H460 lung cancer cells. EMT has been long known to increase abilities of the cells to increase migration, invasion, and survival in circulating system. The present study reveals that treatment of the cancer cells with triclosan at the physiologically related concentrations significantly increased the colony number of the cancer cells assessed by tumor formation assay. Also, the mesenchymal-like morphology and decrease in cell-to-cell adhesion were observed in triclosan-treated cells. Importantly, western blot analysis revealed that triclosan-treated cells exhibited decreased E-cadherin, while the levels of EMT markers, namely N-cadherin, vimentin, snail and slug were found to be significantly up-regulated. Furthermore, EMT induced by triclosan treatment was accompanied by the activation of focal adhesion kinase/ATP dependent tyrosine kinase (FAK/Akt and Ras-related C3 botulinum toxin substrate 1 (Rac1, which enhanced the ability of the cells to migrate and invade. In conclusion, we demonstrated for the first time that triclosan may potentiate cancer cells survival in detached condition and motility via the process of EMT. As mentioned capabilities are required for success in metastasis, the present study provides the novel toxicological information and encourages the awareness of triclosan use in cancer patients.

  19. In vitro development of chemotherapy and targeted therapy drug-resistant cancer cell lines: A practical guide with case studies

    Directory of Open Access Journals (Sweden)

    Martina eMcDermott

    2014-03-01

    Full Text Available The development of a drug-resistant cell line can take from 3-18 months. However, little is published on the methodology of this development process. This article will discuss key decisions to be made prior to starting resistant cell line development; the choice of parent cell line, dose of selecting agent, treatment interval and optimising the dose of drug for the parent cell line. Clinically-relevant drug-resistant cell lines are developed by mimicking the conditions cancer patients experience during chemotherapy and cell lines display between 2-8 fold resistance compared to their parental cell line. Doses of drug administered are low, and a pulsed treatment strategy is often used where the cells recover in drug-free media. High-level laboratory models are developed with the aim of understanding potential mechanisms of resistance to chemotherapy agents. Doses of drug are higher and escalated over time. It is common to have difficulty developing stable clinically-relevant drug-resistant cell lines. A comparative selection strategy of multiple cell lines or multiple chemotherapeutic agents mitigates this risk and gives insight into which agents or type of cell line develops resistance easily. Successful selection strategies from our research are presented. Pulsed-selection produced platinum or taxane-resistant large cell lung cancer (H1299, H460 and temozolomide-resistant melanoma (Malme-3M and HT144 cell lines. Continuous selection produced lapatinib-resistant breast cancer cell line (HCC1954. Techniques for maintaining drug-resistant cell lines are outlined including; maintaining cells with chemotherapy, pulse treating with chemotherapy or returning to master drug-resistant stocks. The heterogeneity of drug-resistant models produced from the same parent cell line with the same chemotherapy agent is explored with reference to P-glycoprotein. Heterogeneity in drug-resistant cell lines reflects the heterogeneity that can occur in clinical drug

  20. ERK/p38 MAPK inhibition reduces radio-resistance to a pulsed proton beam in breast cancer stem cells

    Science.gov (United States)

    Jung, Myung-Hwan; Park, Jeong Chan

    2015-10-01

    Recent studies have identified highly tumorigenic cells with stem cell-like characteristics, termed cancer stem cells (CSCs) in human cancers. CSCs are resistant to conventional radiotherapy and chemotherapy owing to their high DNA repair ability and oncogene overexpression. However, the mechanisms regulating CSC radio-resistance, particularly proton beam resistance, remain unclear. We isolated CSCs from the breast cancer cell lines MCF-7 and MDA-MB-231, which expressed the characteristic breast CSC membrane protein markers CD44+/CD24-/ low , and irradiated the CSCs with pulsed proton beams. We confirmed that CSCs were resistant to pulsed proton beams and showed that treatment with p38 and ERK inhibitors reduced CSC radio-resistance. Based on these results, BCSC radio-resistance can be reduced during proton beam therapy by co-treatment with ERK1/2 or p38 inhibitors, a novel approach to breast cancer therapy.

  1. Thymidylate synthase gene amplification in human colon cancer cell lines resistant to 5-fluorouracil.

    Science.gov (United States)

    Copur, S; Aiba, K; Drake, J C; Allegra, C J; Chu, E

    1995-05-17

    A series of 5-fluorouracil (5-FU)-resistant human colon H630 cancer cell lines were established by continuous exposure of cells to 5-FU. The concentration of 5-FU required to inhibit cell proliferation by 50% (IC50) in the parent colon line (H630) was 5.5 microM. The 5-FU IC50 values for the resistant H630-R1, H630-R10, and H630-R cell lines were 11-, 29-, and 27-fold higher than that for the parent H630 cell line. Using both the radioenzymatic 5-fluoro-2'-deoxyuridine-5'-monophosphate (FdUMP) binding and catalytic assays for measurement of thymidylate synthase (TS) enzyme activity, there was significantly increased TS activity in resistant H630-R1 (13- and 23-fold), H630-R10 (37- and 40-fold), and H630-R (24- and 34-fold) lines, for binding and catalytic assays, respectively, compared with the parent H630 line. The level of TS protein, as determined by western immunoblot analysis, was increased markedly in resistant H630-R1 (23-fold), H630-R10 (33-fold), and H630-R (26-fold) cells. Northern analysis revealed elevations in TS mRNA levels in H630-R1 (18-fold), H630-R10 (39-fold), and H630-R (36-fold) cells relative to parent H630 cells. Although no major rearrangements of the TS gene were noted by Southern analysis, there was significant amplification of the TS gene in 5-FU-resistant cells, which was confirmed by DNA slot blot analysis. These studies demonstrate that continuous exposure of human colon cancer cells to 5-FU leads to TS gene amplification and overexpression of TS protein with resultant development of fluoropyrimidine resistance. PMID:7763285

  2. [Development of three-dimensional breast cancer cell culture drug resistance model].

    Science.gov (United States)

    Xu, Hong; Liu, Wei; Zhang, Xiu-Zhen; Hou, Liang; Lu, Ying-Jin; Chen, Pei-Pei; Zhang, Can; Feng, Di; Kong, Li; Wang, Xiu-Li

    2016-04-25

    The aim of the present study was to develop three-dimensional (3D) culture model, a more pathologically relevant model, of human breast cancer for drug resistance study. MCF-7 cells were embedded within collagen gel to establish 3D culture model. Cellular morphology was observed using Carmine and HE staining. Cell proliferation was evaluated by CCK-8 assay, and cell activity was detected by Live/Dead staining kit. Drug sensitivities of the 3D culture to doxorubicin, carboplatin, 5-fluorouracil were assayed and compared with those of monolayer (2D) culture. In addition, the levels of drug resistance-related genes P-glycoprotein (P-gp), mrp2 mRNA expressions were detected by real time RT-PCR. Expression level of P-gp protein was detected by Western blot. The results showed that MCF-7 cells in 3D culture formed a number of cell aggregates, and most of them displayed good cell viability. The IC50 values of doxorubicin, carboplatin, 5-fluorouracil were all increased significantly in 3D culture compared with those in 2D culture. Moreover, compared with MCF-7 cells in 2D culture, the cells in 3D culture showed increased mRNA levels of P-gp and mrp2, as well as up-regulated protein expression of P-gp. These results suggest that in vitro collagen-embedded culture system of human breast cancer cells represents an improved pathologically relevant 3D microenvironment for breast cancer cells, providing a robust tool to explore the mechanism of drug resistance of cancer cells. PMID:27108905

  3. The Resistance of Breast Cancer Stem Cells to Conventional Hyperthermia and their Sensitivity to Nanoparticle-mediated Photothermal Therapy

    OpenAIRE

    Burke, Andrew R.; Singh, Ravi N.; Carroll, David L.; Wood, James C. S.; D’Agostino, Ralph; Ajayan, P. M.; Torti, Frank M.; Torti, Suzy V.

    2012-01-01

    Breast tumors contain a small population of tumor initiating stem-like cells, termed breast cancer stem cells (BCSCs). These cells, which are refractory to chemotherapy and radiotherapy, are thought to persist following treatment and drive tumor recurrence. We examined whether BCSCs are similarly resistant to hyperthermic therapy, and whether nanoparticles could be used to overcome this resistance. Using a model of triple-negative breast cancer stem cells, we show that BCSCs are markedly resi...

  4. Disruption of insulin receptor function inhibits proliferation in endocrine-resistant breast cancer cells.

    Science.gov (United States)

    Chan, J Y; LaPara, K; Yee, D

    2016-08-11

    The insulin-like growth factor (IGF) system is a well-studied growth regulatory pathway implicated in breast cancer biology. Clinical trials testing monoclonal antibodies directed against the type I IGF receptor (IGF1R) in combination with estrogen receptor-α (ER) targeting have been completed, but failed to show benefits in patients with endocrine-resistant tumors compared to ER targeting alone. We have previously shown that the closely related insulin receptor (InsR) is expressed in tamoxifen-resistant (TamR) breast cancer cells. Here we examined if inhibition of InsR affected TamR breast cancer cells. InsR function was inhibited by three different mechanisms: InsR short hairpin RNA, a small InsR-blocking peptide, S961 and an InsR monoclonal antibody (mAb). Suppression of InsR function by these methods in TamR cells successfully blocked insulin-mediated signaling, monolayer proliferation, cell cycle progression and anchorage-independent growth. This strategy was not effective in parental cells likely because of the presence of IGFR /InsR hybrid receptors. Downregulation of IGF1R in conjunction with InsR inhibition was more effective in blocking IGF- and insulin-mediated signaling and growth in parental cells compared with single-receptor targeting alone. Our findings show TamR cells were stimulated by InsR and were not sensitive to IGF1R inhibition, whereas in tamoxifen-sensitive parental cancer cells, the presence of both receptors, especially hybrid receptors, allowed cross-reactivity of ligand-mediated activation and growth. To suppress the IGF system, targeting of both IGF1R and InsR is optimal in endocrine-sensitive and -resistant breast cancer. PMID:26876199

  5. Crucial role of HMGA1 in the self-renewal and drug resistance of ovarian cancer stem cells

    Science.gov (United States)

    Kim, Dae Kyoung; Seo, Eun Jin; Choi, Eun J; Lee, Su In; Kwon, Yang Woo; Jang, Il Ho; Kim, Seung-Chul; Kim, Ki-Hyung; Suh, Dong-Soo; Seong-Jang, Kim; Lee, Sang Chul; Kim, Jae Ho

    2016-01-01

    Cancer stem cells are a subpopulation of cancer cells characterized by self-renewal ability, tumorigenesis and drug resistance. The aim of this study was to investigate the role of HMGA1, a chromatin remodeling factor abundantly expressed in many different cancers, in the regulation of cancer stem cells in ovarian cancer. Spheroid-forming cancer stem cells were isolated from A2780, SKOV3 and PA1 ovarian cancer cells by three-dimensional spheroid culture. Elevated expression of HMGA1 was observed in spheroid cells along with increased expression of stemness-related genes, such as SOX2, KLF4, ALDH, ABCB1 and ABCG2. Furthermore, spheroid A2780 cells, compared with adherent cells, showed higher resistance to chemotherapeutic agents such as paclitaxel and doxorubicin. HMGA1 knockdown in spheroid cells reduced the proliferative advantage and spheroid-forming efficiency of the cells and the expression of stemness-related genes. HMGA1 overexpression in adherent A2780 cells increased cancer stem cell properties, including proliferation, spheroid-forming efficiency and the expression of stemness-related genes. In addition, HMGA1 regulated ABCG2 promoter activity through HMGA1-binding sites. Knockdown of HMGA1 in spheroid cells reduced resistance to chemotherapeutic agents, whereas the overexpression of HMGA1 in adherent ovarian cancer cells increased resistance to chemotherapeutic agents in vitro. Furthermore, HMGA1-overexpressing A2780 cells showed a significant survival advantage after chemotherapeutic agent treatment in a xenograft tumorigenicity assay. Together, our results provide novel insights regarding the critical role of HMGA1 in the regulation of the cancer stem cell characteristics of ovarian cancer cells, thus suggesting that HMGA1 may be an important target in the development of therapeutics for ovarian cancer patients. PMID:27561949

  6. Involvement of Cox-2 in the metastatic potential of chemotherapy-resistant breast cancer cells

    International Nuclear Information System (INIS)

    A major problem with the use of current chemotherapy regimens for several cancers, including breast cancer, is development of intrinsic or acquired drug resistance, which results in disease recurrence and metastasis. However, the mechanisms underlying this drug resistance are unknown. To study the molecular mechanisms underlying the invasive and metastatic activities of drug-resistant cancer cells, we generated a doxorubicin-resistant MCF-7 breast cancer cell line (MCF-7/DOX). We used MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assays, flow cytometry assays, DNA fragmentation assays, Western blot analysis, cell invasion assays, small interfering RNA (siRNA) transfection, reverse transcription-polymerase chain reaction, experimental lung metastasis models, and gelatin and fibrinogen/plasminogen zymography to study the molecular mechanism of metastatic activities in MCF-7/DOX cells. We found that MCF-7/DOX acquired invasive activities. In addition, Western blot analysis showed increased expression of epidermal growth factor receptor (EGFR) and Cox-2 in MCF-7/DOX cells. Inhibition of Cox-2, phosphoinositide 3-kinase (PI3K)/Akt, or mitogen-activated protein kinase (MAPK) pathways effectively inhibited the invasive activities of MCF-7/DOX cells. Gelatin and fibrinogen/plasminogen zymography analysis showed that the enzymatic activities of matrix metalloproteinase-2 (MMP-2), MMP-9, and urokinase-type plasminogen activator were markedly higher in MCF-7/DOX cells than in the MCF-7 cells. In vitro invasion assays and mouse models of lung metastasis demonstrated that MCF-7/DOX cells acquired invasive abilities. Using siRNAs and agonists specific for prostaglandin E (EP) receptors, we found that EP1 and EP3 played important roles in the invasiveness of MCF-7/DOX cells. We found that the invasive activity of MCF-7/DOX cells is mediated by Cox-2, which is induced by the EGFR-activated PI3K/Akt and MAPK pathways. In addition, EP1 and EP3 are important in

  7. 20(S)-Protopanaxadiol (PPD) analogues chemosensitize multidrug-resistant cancer cells to clinical anticancer drugs.

    Science.gov (United States)

    Liu, Junhua; Wang, Xu; Liu, Peng; Deng, Rongxin; Lei, Min; Chen, Wantao; Hu, Lihong

    2013-07-15

    Novel 20(S)-protopanoxadiol (PPD) analogues were designed, synthesized, and evaluated for the chemosensitizing activity against a multidrug resistant (MDR) cell line (KBvcr) overexpressing P-glycoprotein (P-gp). Structure-activity relationship analysis showed that aromatic substituted aliphatic amine at the 24-positions (groups V) effectively and significantly sensitized P-gp overexpressing multidrug resistant (MDR) cells to anticancer drugs, such as docetaxel (DOC), vincristine (VCR), and adriamycin (ADM). PPD derivatives 12 and 18 showed 1.3-2.6 times more effective reversal ability than verapamil (VER) for DOC and VCR. Importantly, no cytotoxicity was observed by the active PPD analogues (5μM) against both non-MDR and MDR cells, suggesting that PPD analogues serve as novel lead compounds toward a potent and safe resistance modulator. Moreover, a preliminary mechanism study demonstrated that the chemosensitizing activity of PPD analogues results from inhibition of P-glycoprotein (P-gp) overexpressed in MDR cancer cells. PMID:23683834

  8. Angiogenin mediates androgen-stimulated growth of prostate cancer cells and correlates with castration resistance

    OpenAIRE

    Li, Shuping; Hu, Miaofen G.; Sun, Yeqing; YOSHIOKA, NORIE; IBARAGI, SOICHIRO; Sheng, Jinghao; Sun, Guangjie; Kishimoto, Koji; Hu, Guo-fu

    2013-01-01

    Androgen receptor (AR) is a critical effector of prostate cancer (PCa) development and progression. Androgen-dependent PCa rely on the function of AR for growth and progression. Many castration-resistant PCa continue to depend on AR signaling for survival and growth. Ribosomal RNA (rRNA) is essential for both androgen-dependent and castration-resistant growth of PCa cells. During androgen-dependent growth of prostate cells, androgen-AR signaling leads to the accumulation of rRNA. However, the...

  9. Low expression of SLOOP associated with paclitaxel resistance in ovarian cancer cell line

    Institute of Scientific and Technical Information of China (English)

    GAO Jian-hua; HE Zhi-juan; WANG Qi; LI Xin; LI Yi-xuan; LIU Min; ZHENG Jian-hua; TANG Hua

    2008-01-01

    Background Recent studies indicate that Sl 00P expression may be a biomarker that can predict the success of cancer chemotherapy. Whether it is relevant to chemOtherapeutics in ovarian cancer is unknown.In this study,we investigated the association of S1OOP expression with paclitaxel sensitivity in ovarian cancer cell lines.Methods We measured S1 OOP expression and paclitaxel resistance profiles in parent SKOV3 and OVCAH3 cell lines.Then,the two cell lines were transiently transfected with SlOOP siRNA.We also constructed an OVCAR3 cell clone that stably overexpressed SIOOP The effect of S100P expression level on the survival of cells exposed to paclitaxel was measured using the MTT assav.S1OOP expression was evaluated by semi-quantitative RT.PCR and Western blotting.Significance of differences was calculated using independent samples t-test and one way analysis of variance(ANOVA).Results Lower S1 00P expression was associated with a survival advantage in OVCAR3 cells exposed to paclitaxel;the survival advantage in SKOV3 cells was smaller Pcells that had been transfected with S1 00P siRNA before being exposed to paciitaxel(P<0.05).Consistent with this,the OVCAR3 cell clone that was transfected to overexpress S1 00P was more sensitive to paclitaxelf P<0.05).Conclusions Low S1 00P expression contributes to drug resistance to paclitaxel in ovarian cancer cell lines.S100P expression thus might be a marker that can predict the effectiveness of paclitaxel based chemotherapy.Such a marker could be helpful in improving individual medication regimens for ovarian cancer patients.

  10. Overexpression of long non-coding RNA PVT1 in ovarian cancer cells promotes cisplatin resistance by regulating apoptotic pathways

    OpenAIRE

    Liu, Enling; Liu, Zheng; Zhou, Yuxiu; MI, RUORAN; Wang, Dehua

    2015-01-01

    Ovarian cancer is the most lethal gynecologic malignancy. Cisplatin is a very effective cancer chemotherapy drug, but cisplatin resistance is a crucial problem of therapy failure. Overexpression of PVT1 has been demonstrated in ovarian cancer. The mRNA level of PVT1 in ovarian cancer tissues of cisplatin-resistant patients and cisplatin-sensitive patients, cisplatin-resistant cells SKOV-3/DDP and A2780/DDP, cisplatin-sensitive cells SKOV-3 and A2780 were determined by qRT-PCR. The influence o...

  11. Curcumin Induces Cell Death and Restores Tamoxifen Sensitivity in the Antiestrogen-Resistant Breast Cancer Cell Lines MCF-7/LCC2 and MCF-7/LCC9

    OpenAIRE

    Min Jiang; Ou Huang; Xi Zhang; Zuoquan Xie; Aijun Shen; Hongchun Liu; Meiyu Geng; Kunwei Shen

    2013-01-01

    Curcumin, a principal component of turmeric (Curcuma longa), has potential therapeutic activities against breast cancer through multiple signaling pathways. Increasing evidence indicates that curcumin reverses chemo-resistance and sensitizes cancer cells to chemotherapy and targeted therapy in breast cancer. To date, few studies have explored its potential antiproliferation effects and resistance reversal in antiestrogen-resistant breast cancer. In this study, we therefore investigated the ef...

  12. Decreased chicken ovalbumin upstream promoter transcription factor II expression in tamoxifen-resistant breast cancer cells.

    Science.gov (United States)

    Riggs, Krista A; Wickramasinghe, Nalinie S; Cochrum, Renate K; Watts, Mary Beth; Klinge, Carolyn M

    2006-10-15

    Tamoxifen (TAM) is successfully used for the treatment and prevention of breast cancer. However, many patients that are initially TAM responsive develop tumors that are antiestrogen/TAM resistant (TAM-R). The mechanism behind TAM resistance in estrogen receptor alpha (ERalpha)-positive tumors is not understood. The orphan nuclear receptor chicken ovalbumin upstream promoter transcription factor (COUP-TF)-I interacts directly with 4-hydroxytamoxifen (4-OHT)- and estradiol (E(2))-occupied ERalpha, corepressors NCoR and SMRT, and inhibit E(2)-induced gene transcription in breast cancer cells. Here we tested the hypothesis that reduced COUP-TFI and COUP-TFII correlate with TAM resistance. We report for the first time that COUP-TFII, but not COUP-TFI, is reduced in three antiestrogen/TAM-R cell lines derived from TAM-sensitive (TAM-S) MCF-7 human breast cancer cells and in MDA-MB-231 cells compared with MCF-7. ERalpha and ERbeta protein expression was not different between TAM-S and TAM-R cells, but progesterone receptor (PR) was decreased in TAM-R cells. Further, E(2) increased COUP-TFII transcription in MCF-7, but not TAM-R, cells. Importantly, reexpression of COUP-TFII in TAM-S cells to levels comparable to those in MCF-7 was shown to increase 4-OHT-mediated growth inhibition and increased apoptosis. Conversely, knockdown of COUP-TFII in TAM-S MCF-7 cells blocked growth inhibitory activity and increased 4-OHT agonist activity. 4-OHT increased COUP-TFII-ERalpha interaction approximately 2-fold in MCF-7 cells. COUP-TFII expression in TAM-R cells also inhibited 4-OHT-induced endogenous PR and pS2 mRNA expression. These data indicate that reduced COUP-TFII expression correlates with acquired TAM resistance in human breast cancer cell lines and that COUP-TFII plays a role in regulating the growth inhibitory activity of TAM in breast cancer cells. PMID:17047084

  13. Cigarette smoke promotes drug resistance and expansion of cancer stem cell-like side population.

    Directory of Open Access Journals (Sweden)

    Yi An

    Full Text Available It is well known that many patients continue to smoke cigarettes after being diagnosed with cancer. Although smoking cessation has typically been presumed to possess little therapeutic value for cancer, a growing body of evidence suggests that continued smoking is associated with reduced efficacy of treatment and a higher incidence of recurrence. We therefore investigated the effect of cigarette smoke condensate (CSC on drug resistance in the lung cancer and head and neck cancer cell lines A549 and UMSCC-10B, respectively. Our results showed that CSC significantly increased the cellular efflux of doxorubicin and mitoxantrone. This was accompanied by membrane localization and increased expression of the multi-drug transporter ABCG2. The induced efflux of doxorubicin was reversed upon addition of the specific ABCG2 inhibitor Fumitremorgin C, confirming the role of ABCG2. Treatment with CSC increased the concentration of phosphorylated Akt, while addition of the PI3K inhibitor LY294002 blocked doxorubicin extrusion, suggesting that Akt activation is required for CSC-induced drug efflux. In addition, CSC was found to promote resistance to doxorubicin as determined by MTS assays. This CSC-induced doxurbicin-resistance was mitigated by mecamylamine, a nicotinic acetylcholine receptor inhibitor, suggesting that nicotine is at least partially responsible for the effect of CSC. Lastly, CSC increased the size of the side population (SP, which has been linked to a cancer stem cell-like phenotype. In summary, CSC promotes chemoresistance via Akt-mediated regulation of ABCG2 activity, and may also increase the proportion of cancer stem-like cells, contributing to tumor resilience. These findings underscore the importance of smoking cessation following a diagnosis of cancer, and elucidate the mechanisms of continued smoking that may be detrimental to treatment.

  14. Mitochondrial-Targeting MET Kinase Inhibitor Kills Erlotinib-Resistant Lung Cancer Cells.

    Science.gov (United States)

    Yang, Tianming; Ng, Wai Har; Chen, Huan; Chomchopbun, Kamon; Huynh, The Hung; Go, Mei Lin; Kon, Oi Lian

    2016-08-11

    Lung cancer cells harboring activating EGFR mutations acquire resistance to EGFR tyrosine kinase inhibitors (TKIs) by activating several bypass mechanisms, including MET amplification and overexpression. We show that a significant proportion of activated MET protein in EGFR TKI-resistant HCC827 lung cancer cells resides within the mitochondria. Targeting the total complement of MET in the plasma membrane and mitochondria should render these cells more susceptible to cell death and hence provide a means of circumventing drug resistance. Herein, the mitochondrial targeting triphenylphosphonium (TPP) moiety was introduced to the selective MET kinase inhibitor PHA665752. The resulting TPP analogue rapidly localized to the mitochondria of MET-overexpressing erlotinib-resistant HCC827 cells, partially suppressed the phosphorylation (Y1234/Y1235) of MET in the mitochondrial inner membrane and was as cytotoxic and apoptogenic as the parent compound. These findings provide support for the targeting of mitochondrial MET with a TPP-TKI conjugate as a means of restoring responsiveness to chemotherapy. PMID:27563407

  15. Cytotoxicity of Elaoephorbia drupifera and other Cameroonian medicinal plants against drug sensitive and multidrug resistant cancer cells

    OpenAIRE

    Kuete, Victor; Voukeng, Igor K; Tsobou, Roger; Mbaveng, Armelle T; Wiench, Benjamin; Beng, Veronique P; Efferth, Thomas

    2013-01-01

    Background Multidrug resistance (MDR) is a major hurdle for cancer treatment worldwide and accounts for chemotherapy failure in over 90% of patients with metastatic cancer. Evidence of the cytotoxicity of Cameroonian plants against cancer cell lines including MDR phenotypes is been intensively and progressively provided. The present work was therefore designed to evaluate the cytotoxicity of the methanol extracts of twenty-two Cameroonian medicinal plants against sensitive and MDR cancer cell...

  16. 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

    (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......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...... 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...

  17. High heterogeneity of plasma membrane microfluidity in multidrug-resistant cancer cells

    Science.gov (United States)

    Boutin, Céline; Roche, Yann; Millot, Christine; Deturche, Régis; Royer, Pascal; Manfait, Michel; Plain, Jérôme; Jeannesson, Pierre; Millot, Jean-Marc; Jaffiol, Rodolphe

    2009-05-01

    Diffusion-time distribution analysis (DDA) has been used to explore the plasma membrane fluidity of multidrug-resistant cancer cells (LR73 carcinoma cells) and also to characterize the influence of various membrane agents present in the extracellular medium. DDA is a recent single-molecule technique, based on fluorescence correlation spectroscopy (FCS), well suited to retrieve local organization of cell membrane. The method was conducted on a large number of living cells, which enabled us to get a detailed overview of plasma membrane microviscosity, and plasma membrane micro-organization, between the cells of the same line. Thus, we clearly reveal the higher heterogeneity of plasma membrane in multidrug-resistant cancer cells in comparison with the nonresistant ones (denoted sensitive cells). We also display distinct modifications related to a membrane fluidity modulator, benzyl alcohol, and two revertants of multidrug resistance, verapamil and cyclosporin-A. A relation between the distribution of the diffusion-time values and the modification of membrane lateral heterogeneities is proposed.

  18. Cancer cell resistance to AURK-directed therapy: implications for anti-cancer strategies

    Czech Academy of Sciences Publication Activity Database

    Hrabáková, Rita; Kollareddy, M.; Mairychová, Kateřina; Halada, Petr; Hajduch, M.; Kovářová, Hana

    Praha: Institute of Animal Physiology and Genetics ASCR, v. v. i, 2011. s. 23-23. [5th Central and Eastern European Proteomics Conference.. 19.09.2011-22.9.2011, Praha] R&D Projects: GA MŠk LC07017 Institutional research plan: CEZ:AV0Z50450515; CEZ:AV0Z50200510 Keywords : drug resistance * anti-cancer therapy * proteomics * biomarker Subject RIV: CE - Biochemistry

  19. Targeting HDAC with a novel inhibitor effectively reverses paclitaxel resistance in non-small cell lung cancer via multiple mechanisms

    OpenAIRE

    Wang, L.; Li, H.; Ren, Y; Zou, S; FANG, W.; Jiang, X.; L. Jia; M. Li; Liu, X.; Yuan, X.; G. Chen; Yang, J; Wu, C.

    2016-01-01

    Chemotherapy paclitaxel yields significant reductions in tumor burden in the majority of advanced non-small cell lung cancer (NSCLC) patients. However, acquired resistance limits its clinical use. Here we demonstrated that the histone deacetylase (HDAC) was activated in paclitaxel-resistant NSCLC cells, and its activation promoted proliferation and tumorigenesis of paclitaxel-resistant NSCLC cells in vitro and in vivo. By contrast, knockdown of HDAC1, a primary isoform of HDAC, sensitized res...

  20. MicroRNA-21 directly targets MARCKS and promotes apoptosis resistance and invasion in prostate cancer cells

    International Nuclear Information System (INIS)

    Prostate cancer is one of the most common malignant cancers in men. Recent studies have shown that microRNA-21 (miR-21) is overexpressed in various types of cancers including prostate cancer. Studies on glioma, colon cancer cells, hepatocellular cancer cells and breast cancer cells have indicated that miR-21 is involved in tumor growth, invasion and metastasis. However, the roles of miR-21 in prostate cancer are poorly understood. In this study, the effects of miR-21 on prostate cancer cell proliferation, apoptosis, and invasion were examined. In addition, the targets of miR-21 were identified by a reported RISC-coimmunoprecipitation-based biochemical method. Inactivation of miR-21 by antisense oligonucleotides in androgen-independent prostate cancer cell lines DU145 and PC-3 resulted in sensitivity to apoptosis and inhibition of cell motility and invasion, whereas cell proliferation were not affected. We identified myristoylated alanine-rich protein kinase c substrate (MARCKS), which plays key roles in cell motility, as a new target in prostate cancer cells. Our data suggested that miR-21 could promote apoptosis resistance, motility, and invasion in prostate cancer cells and these effects of miR-21 may be partly due to its regulation of PDCD4, TPM1, and MARCKS. Gene therapy using miR-21 inhibition strategy may therefore be useful as a prostate cancer therapy.

  1. The cancer stem-cell signaling network and resistance to therapy.

    Science.gov (United States)

    Carnero, A; Garcia-Mayea, Y; Mir, C; Lorente, J; Rubio, I T; LLeonart, M E

    2016-09-01

    The study of cancer stem cells (CSCs) has shown that tumors are driven by a subpopulation of self-renewing CSCs that retain the capacity to engender the various differentiated cell populations that form tumors. The characterization of CSCs has indicated that CSCs are remarkably resistant to conventional radio- and chemo-therapy. Clinically, the remaining populations of CSC are responsible for metastasis and recurrence in patients with cancer, which can lead to the disease becoming chronic and incurable. Therefore, the elimination of CSCs is an important goal of cancer treatments. Furthermore, CSCs are subject to strong regulation by the surrounding microenvironment, which also impacts tumor responses. In this review, we discuss the mechanisms by which pathways that are defective in CSCs influence ultimately therapeutic and clinical outcomes. PMID:27434881

  2. Circumvention of multi-drug resistance of cancer cells by Chinese herbal medicines

    Directory of Open Access Journals (Sweden)

    Lin Ge

    2010-07-01

    Full Text Available Abstract Multi-drug resistance (MDR of cancer cells severely limits therapeutic outcomes. A proposed mechanism for MDR involves the efflux of anti-cancer drugs from cancer cells, primarily mediated by ATP-binding cassette (ABC membrane transporters including P-glycoprotein. This article reviews the recent progress of using active ingredients, extracts and formulae from Chinese medicine (CM in circumventing ABC transporters-mediated MDR. Among the ABC transporters, Pgp is the most extensively studied for its role in MDR reversal effects. While other MDR reversal mechanisms remain unclear, Pgp inhibition is a criterion for further mechanistic study. More mechanistic studies are needed to fully establish the pharmacological effects of potential MDR reversing agents.

  3. Safety and efficacy of resistance training in germ cell cancer patients undergoing chemotherapy

    DEFF Research Database (Denmark)

    Christensen, Jesper Frank; Jones, L W; Tolver, Anders;

    2014-01-01

    Abstract Background: Bleomycin–etoposid–cisplatin (BEP) chemotherapy is curative in most patients with disseminated germ cell cancer (GCC) but also associated with toxic actions and dysfunction in non-targeted tissues. We investigated changes in muscle function during BEP and the safety and......–4 sets/exercise of 10–15 repetitions at 12–15 repetition maximum load. The primary endpoint was muscle fibre size, assessed in muscle biopsies from musculus vastus lateralis. Secondary endpoints were fibre phenotype composition, body composition, strength, blood biochemistry and patient...... efficacy of resistance training to modulate these changes. Methods: Thirty GCC patients were randomly assigned to resistance training (resistance training group (INT), n=15) or usual care (CON, n=15) during 9 weeks of BEP therapy. Resistance training consisted of thrice weekly sessions of four exercises, 3...

  4. Overexpression of S100A4 in human cancer cell lines resistant to methotrexate

    Directory of Open Access Journals (Sweden)

    Hernández Jose L

    2010-06-01

    Full Text Available Abstract Background Methotrexate is a chemotherapeutic drug that is used in therapy of a wide variety of cancers. The efficiency of treatment with this drug is compromised by the appearance of resistance. Combination treatments of MTX with other drugs that could modulate the expression of genes involved in MTX resistance would be an adequate strategy to prevent the development of this resistance. Methods The differential expression pattern between sensitive and MTX-resistant cells was determined by whole human genome microarrays and analyzed with the GeneSpring GX software package. A global comparison of all the studied cell lines was performed in order to find out differentially expressed genes in the majority of the MTX-resistant cells. S100A4 mRNA and protein levels were determined by RT-Real-Time PCR and Western blot, respectively. Functional validations of S100A4 were performed either by transfection of an expression vector for S100A4 or a siRNA against S100A4. Transfection of an expression vector encoding for β-catenin was used to inquire for the possible transcriptional regulation of S100A4 through the Wnt pathway. Results S100A4 is overexpressed in five out of the seven MTX-resistant cell lines studied. Ectopic overexpression of this gene in HT29 sensitive cells augmented both the intracellular and extracellular S100A4 protein levels and caused desensitization toward MTX. siRNA against S100A4 decreased the levels of this protein and caused a chemosensitization in combined treatments with MTX. β-catenin overexpression experiments support a possible involvement of the Wnt signaling pathway in S100A4 transcriptional regulation in HT29 cells. Conclusions S100A4 is overexpressed in many MTX-resistant cells. S100A4 overexpression decreases the sensitivity of HT29 colon cancer human cells to MTX, whereas its knockdown causes chemosensitization toward MTX. Both approaches highlight a role for S100A4 in MTX resistance.

  5. Overexpression of S100A4 in human cancer cell lines resistant to methotrexate

    International Nuclear Information System (INIS)

    Methotrexate is a chemotherapeutic drug that is used in therapy of a wide variety of cancers. The efficiency of treatment with this drug is compromised by the appearance of resistance. Combination treatments of MTX with other drugs that could modulate the expression of genes involved in MTX resistance would be an adequate strategy to prevent the development of this resistance. The differential expression pattern between sensitive and MTX-resistant cells was determined by whole human genome microarrays and analyzed with the GeneSpring GX software package. A global comparison of all the studied cell lines was performed in order to find out differentially expressed genes in the majority of the MTX-resistant cells. S100A4 mRNA and protein levels were determined by RT-Real-Time PCR and Western blot, respectively. Functional validations of S100A4 were performed either by transfection of an expression vector for S100A4 or a siRNA against S100A4. Transfection of an expression vector encoding for β-catenin was used to inquire for the possible transcriptional regulation of S100A4 through the Wnt pathway. S100A4 is overexpressed in five out of the seven MTX-resistant cell lines studied. Ectopic overexpression of this gene in HT29 sensitive cells augmented both the intracellular and extracellular S100A4 protein levels and caused desensitization toward MTX. siRNA against S100A4 decreased the levels of this protein and caused a chemosensitization in combined treatments with MTX. β-catenin overexpression experiments support a possible involvement of the Wnt signaling pathway in S100A4 transcriptional regulation in HT29 cells. S100A4 is overexpressed in many MTX-resistant cells. S100A4 overexpression decreases the sensitivity of HT29 colon cancer human cells to MTX, whereas its knockdown causes chemosensitization toward MTX. Both approaches highlight a role for S100A4 in MTX resistance

  6. Intraperitoneal delivery of a novel liposome-encapsulated paclitaxel redirects metabolic reprogramming and effectively inhibits cancer stem cells in Taxol®-resistant ovarian cancer

    OpenAIRE

    Shen, Yao-An; Li, Wai-Hou; Chen, Po-Hung; He, Chun-Lin; Chang, Yen-Hou; Chuang, Chi-Mu

    2015-01-01

    Taxol® remained as the mainstay therapeutic agent in the treatment of ovarian cancer, however recurrence rate is still high. Cancer stem cells (CSCs) represent a subset of cells in the bulk of tumors and play a central role in inducing drug resistance and recurrence. Furthermore, cancer metabolism has been an area under intensive investigation, since accumulating evidence has shown that CSCs and cancer metabolism are closely linked, an effect named as metabolic reprogramming. In this work, we...

  7. β-Elemene Reverses Chemoresistance of Breast Cancer Cells by Reducing Resistance Transmission via Exosomes

    Directory of Open Access Journals (Sweden)

    Jun Zhang

    2015-07-01

    Full Text Available Background: Currently, exosomes that act as mediators of intercellular communication are being researched extensively. Our previous studies confirmed that these exosomes contain microRNAs (miRNAs that could alter chemo-susceptibility, which is partly attributed to the successful intercellular transfer of multidrug resistance (MDR-specific miRNAs. We also confirmed that β-elemene could influence MDR-related miRNA expression and regulate the expression of the target genes PTEN and Pgp, which may lead to the reversal of the chemoresistant breast cancer (BCA cells. We are the first to report these findings, and we propose the following logical hypothesis: β-elemene can mediate MDR-related miRNA expression in cells, thereby affecting the exosome contents, reducing chemoresistance transmission via exosomes, and reversing the drug resistance of breast cancer cells. Methods: MTT-cytotoxic, miRNA microarray, real-time quantitative PCR, Dual Luciferase Activity Assay, and Western blot analysis were performed to investigate the impact of β-elemene on the expression of chemoresistance specific miRNA and PTEN as well as Pgp in chemoresistant BCA exosomes. Results: Drug resistance can be reversed by β-elemene related to exosomes. There were 104 differentially expressed miRNAs in the exosomes of two chemoresistant BCA cells: adriacin (Adr - resistant MCF-7 cells (MCF-7/Adr and docetaxel (Doc - resistant MCF-7 cells (MCF-7/Doc that underwent treatment. Of these, 31 miRNAs were correlated with the constant changes in the MDR. The expression of miR-34a and miR-452 can lead to changes in the characteristics of two chemoresistant BCA exosomes: MCF-7/Adr exosomes (A/exo and MCF-7/Doc exosomes (D/exo. The PTEN expression affected by β-elemene was significantly increased, and the Pgp expression affected by β-elemene was significantly decreased in both cells and exosomes. β-elemene induced a significant increase in the apoptosis rate in both MCF-7/Doc and MCF-7

  8. Dynamic Assessment of Mitoxantrone Resistance and Modulation of Multidrug Resistance by Valspodar (PSC833) in Multidrug Resistance Human Cancer Cells

    OpenAIRE

    Shen, Fei; Barbara J Bailey; Chu, Shaoyou; Bence, Aimee K.; Xue, Xinjian; Erickson, Priscilla; Safa, Ahmad R.; Beck, William T.; Erickson, Leonard C.

    2009-01-01

    P-glycoprotein (Pgp), a member of the ATP-binding cassette transporter family, is one of the major causes for multidrug resistance (MDR). We report using confocal microscopy to study the roles of Pgp in mediating the efflux of the anticancer agent mitoxantrone and the reversal of MDR by the specific Pgp inhibitor valspodar (PSC833). The net uptake and efflux of mitoxantrone and the effect of PSC833 were quantified and compared in Pgp-expressing human cancer MDA-MB-435 ...

  9. Prolactin confers resistance against cisplatin in breast cancer cells by activating glutathione-S-transferase.

    Science.gov (United States)

    LaPensee, Elizabeth W; Schwemberger, Sandy J; LaPensee, Christopher R; Bahassi, El Mustapha; Afton, Scott E; Ben-Jonathan, Nira

    2009-08-01

    Resistance to chemotherapy is a major obstacle for successful treatment of breast cancer patients. Given that prolactin (PRL) acts as an anti-apoptotic/survival factor in the breast, we postulated that it antagonizes cytotoxicity by chemotherapeutic drugs. Treatment of breast cancer cells with PRL caused variable resistance to taxol, vinblastine, doxorubicin and cisplatin. PRL prevented cisplatin-induced G(2)/M cell cycle arrest and apoptosis. In the presence of PRL, significantly less cisplatin was bound to DNA, as determined by mass spectroscopy, and little DNA damage was seen by gamma-H2AX staining. PRL dramatically increased the activity of glutathione-S-transferase (GST), which sequesters cisplatin in the cytoplasm; this increase was abrogated by Jak and mitogen-activated protein kinase inhibitors. PRL upregulated the expression of the GSTmu, but not the pi, isozyme. A GST inhibitor abrogated antagonism of cisplatin cytotoxicity by PRL. In conclusion, PRL confers resistance against cisplatin by activating a detoxification enzyme, thereby reducing drug entry into the nucleus. These data provide a rational explanation for the ineffectiveness of cisplatin in breast cancer, which is characterized by high expression of both PRL and its receptor. Suppression of PRL production or blockade of its actions should benefit patients undergoing chemotherapy by allowing for lower drug doses and expanded drug options. PMID:19443905

  10. Chemotherapeutic activities of Carthami Flos and its reversal effect on multidrug resistance in cancer cells.

    Science.gov (United States)

    Wu, Jimmy Yiu-Cheong; Yu, Zhi-Ling; Fong, Wang-Fun; Shi, Yi-Qian

    2013-01-01

    Multidrug-resistance (MDR) represents a major cause of failure in cancer chemotherapy. The need for a reduction in MDR by natural-product-based drugs of low toxicity led to the current investigation of applying medicinal herbs in future cancer adjuvant therapy. Carthami Flos (CF), the dried flower of safflower (Carthamus tinctorius L.), is one of the most popular traditional Chinese medicinal herbs used to alleviate pain, increase circulation, and reduce blood-stasis syndrome. The drug resistance index of the total extract of CF in MDR KB-V1 cells and its synergistic effects with other chemotherapeutic agents were studied. SRB cell viability assays were used to quantify growth inhibition after exposure to single drug and in combinations with other chemotherapeutic agents using the median effect principle. The combination indexes were then calculated according to the classic isobologram equation. The results revealed that CF showed a drug resistance index of 0.096. In combination with other chemotherapeutic agents, it enhanced their chemo-sensitivities by 2.8 to 4.0 folds and gave a general synergism in cytotoxic effect. These results indicate that CF could be a potential alternative adjuvant antitumour herbal medicine representing a promising approach to the treatment of some malignant and MDR cancers in the future. PMID:24146498

  11. Differential microRNA expression signatures and cell type-specific association with Taxol resistance in ovarian cancer cells

    Directory of Open Access Journals (Sweden)

    Kim YW

    2014-02-01

    Full Text Available Yong-Wan Kim,1 Eun Young Kim,1 Doin Jeon,1 Juinn-Lin Liu,2 Helena Suhyun Kim,3 Jin Woo Choi,4 Woong Shick Ahn5 1Cancer Research Institute of Medical Science, The Catholic University of Korea, Seoul, Republic of Korea; 2Brain Tumor Center, Department of Neuro-Oncology, The University of Texas MD Anderson Cancer Center, TX, USA; 3Cancer Rehab Laboratory, RH Healthcare Systems Inc, TX, USA; 4Harvard Medical School and Wellman Center for Photomedicine, Cambridge, MA, USA; 5Department of Obstetrics and Gynecology, The Catholic University of Korea, Seoul, Republic of Korea Abstract: Paclitaxel (Taxol resistance remains a major obstacle for the successful treatment of ovarian cancer. MicroRNAs (miRNAs have oncogenic and tumor suppressor activity and are associated with poor prognosis phenotypes. miRNA screenings for this drug resistance are needed to estimate the prognosis of the disease and find better drug targets. miRNAs that were differentially expressed in Taxol-resistant ovarian cancer cells, compared with Taxol-sensitive cells, were screened by Illumina Human MicroRNA Expression BeadChips. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR was used to identify target genes of selected miRNAs. Kaplan–Meier survival analysis was applied to identify dysregulated miRNAs in ovarian cancer patients using data from The Cancer Genome Atlas. A total of 82 miRNAs were identified in ovarian carcinoma cells compared to normal ovarian cells. miR-141, miR-106a, miR-200c, miR-96, and miR-378 were overexpressed, and miR-411, miR-432, miR-494, miR-409-3p, and miR-655 were underexpressed in ovarian cancer cells. Seventeen miRNAs were overexpressed in Taxol-resistant cells, including miR-663, miR-622, and HS_188. Underexpressed miRNAs in Taxol-sensitive cells included miR-497, miR-187, miR-195, and miR-107. We further showed miR-663 and miR-622 as significant prognosis markers of the chemo-resistant patient group. In particular, the

  12. Hepatic cancer stem cells and drug resistance: Relevance in targeted therapies for hepatocellular carcinoma

    Directory of Open Access Journals (Sweden)

    Caecilia HC Sukowati, Natalia Rosso, Lory S Crocè, Claudio Tiribelli

    2010-03-01

    Full Text Available Hepatocellular carcinoma (HCC is one of most common malignancies in the world. Systemic treatments for HCC, particularly for advanced stages, are limited by the drug resistance phenomenon which ultimately leads to therapy failure. Recent studies have indicated an association between drug resistance and the existence of the cancer stem cells (CSCs as tumor initiating cells. The CSCs are resistant to conventional chemotherapies and might be related to the mechanisms of the ATP Binding Cassette (ABC transporters and alterations in the CSCs signaling pathways. Therefore, to contribute to the development of new HCC treatments, further information on the characterization of CSCs, the modulation of the ABC transporters expression and function and the signaling pathway involved in the self renewal, initiation and maintenance of the cancer are required. The combination of transporters modulators/inhibitors with molecular targeted therapies may be a potent strategy to block the tumoral progression. This review summarizes the association of CSCs, drug resistance, ABC transporters activities and changes in signaling pathways as a guide for future molecular therapy for HCC.

  13. Overexpression of long non-coding RNA PVT1 in ovarian cancer cells promotes cisplatin resistance by regulating apoptotic pathways.

    Science.gov (United States)

    Liu, Enling; Liu, Zheng; Zhou, Yuxiu; Mi, Ruoran; Wang, Dehua

    2015-01-01

    Ovarian cancer is the most lethal gynecologic malignancy. Cisplatin is a very effective cancer chemotherapy drug, but cisplatin resistance is a crucial problem of therapy failure. Overexpression of PVT1 has been demonstrated in ovarian cancer. The mRNA level of PVT1 in ovarian cancer tissues of cisplatin-resistant patients and cisplatin-sensitive patients, cisplatin-resistant cells SKOV-3/DDP and A2780/DDP, cisplatin-sensitive cells SKOV-3 and A2780 were determined by qRT-PCR. The influence of the knockdown or overexpression of PVT1 on cisplatin resistance was measured by measuring the cytotoxicity of cisplatin and the apoptotic rate of ovarian cancer cells was detected by CCK-8 assay and flow cytometry, respectively. The mRNA levels and protein expression of TGF-β1, Smad4, p-Smad4 and Caspase-3 in apoptotic pathways were determined. The mRNA level of PVT1 was significantly higher in ovarian cancer tissues of cisplatin-resistant patients and cisplatin-resistant cells. SKOV-3/DDP and A2780/DDP cell viability and the percentage of apoptotic cells after transfection with PVT-1 siRNA and treated with cisplatin was markedly lower and higher than the control, respectively. Moreover, the overexpression of PVT1 exhibited the anti-apoptotic property in SKOV-3 and A2780 cells after transfection with LV-PVT1-GFP and treated with cisplatin. The mRNA levels and protein expression of TGF-β1, p-Smad4 and Caspase-3 were much higher in cisplatin-resistant cells transfected with siPVT1. Overexpression of LncRNA PVT1 in ovarian cancer promotes cisplatin resistance by regulating apoptotic pathways. PMID:26884974

  14. Downregulation of HuR as a new mechanism of doxorubicin resistance in breast cancer cells

    Directory of Open Access Journals (Sweden)

    Latorre Elisa

    2012-03-01

    Full Text Available Abstract Background HuR, an RNA binding protein involved in the post-transcriptional regulation of a wide spectrum of mRNAs, has been demonstrated to be a determinant of carcinogenesis and tumor aggressiveness in several cancer types. In this study, we investigated the role of HuR in the apoptosis and in the chemoresistance induced by the widely used anticancer drug doxorubicin in human breast cancer cells (MCF-7. Results We showed that HuR acts in the early phase of cell response to doxorubicin, being induced to translocate into the cytoplasm upon phosphorylation. Reducing HuR levels diminished the apoptotic response to doxorubicin. Doxorubicin-induced apoptosis was also correlated with the presence of HuR in the cytoplasm. Rottlerin, which was able to block HuR nuclear export, had correspondingly antagonistic effects with doxorubicin on cell toxicity. The proapoptotic activity of HuR was not due to cleavage to an active form, as was previously reported. In in vitro selected doxorubicin resistant MCF-7 cells (MCF-7/doxoR overexpressing the multidrug resistance (MDR related ABCG2 transporter, we observed a significant HuR downregulation that was paralleled by a corresponding downregulation of HuR targets and by loss of rottlerin toxicity. Restoration of HuR expression in these cells resensitized MCF-7/doxoR cells to doxorubicin, reactivating the apoptotic response. Conclusions The present study shows that HuR is necessary to elicit the apoptotic cell response to doxorubicin and that restoration of HuR expression in resistant cells resensitizes them to the action of this drug, thereby identifying HuR as a key protein in doxorubicin pharmacology.

  15. Antitumor effect of 5-fluorouracil is enhanced by rosemary extract in both drug sensitive and resistant colon cancer cells.

    Science.gov (United States)

    González-Vallinas, Margarita; Molina, Susana; Vicente, Gonzalo; de la Cueva, Ana; Vargas, Teodoro; Santoyo, Susana; García-Risco, Mónica R; Fornari, Tiziana; Reglero, Guillermo; Ramírez de Molina, Ana

    2013-06-01

    5-Fluorouracil (5-FU) is the most used chemotherapeutic agent in colorectal cancer. However, resistance to this drug is relatively frequent, and new strategies to overcome it are urgently needed. The aim of this work was to determine the antitumor properties of a supercritical fluid rosemary extract (SFRE), alone and in combination with 5-FU, as a potential adjuvant therapy useful for colon cancer patients. This extract has been recognized as a healthy component by the European Food Safety Authority (EFSA). The effects of SFRE both alone and in combination with 5-FU were evaluated in different human colon cancer cells in terms of cell viability, cytotoxicity, and cell transformation. Additionally, colon cancer cells resistant to 5-FU were used to assay the effects of SFRE on drug resistance. Finally, qRT-PCR was performed to ascertain the mechanism by which SFRE potentiates the effect of 5-FU. Our results show that SFRE displays dose-dependent antitumor activities and exerts a synergistic effect in combination with 5-FU on colon cancer cells. Furthermore, SFRE sensitizes 5-FU-resistant cells to the therapeutic activity of this drug, constituting a beneficial agent against both 5-FU sensitive and resistant tumor cells. Gene expression analysis indicates that the enhancement of the effect of 5-FU by SFRE might be explained by the downregulation of TYMS and TK1, enzymes related to 5-FU resistance. PMID:23557932

  16. Small cell lung cancer transformation and T790M mutation: complimentary roles in acquired resistance to kinase inhibitors in lung cancer

    OpenAIRE

    Kenichi Suda; Isao Murakami; Kazuko Sakai; Hiroshi Mizuuchi; Shigeki Shimizu; Katsuaki Sato; Kenji Tomizawa; Shuta Tomida; Yasushi Yatabe; Kazuto Nishio; Tetsuya Mitsudomi

    2015-01-01

    Lung cancers often harbour a mutation in the epidermal growth factor receptor (EGFR) gene. Because proliferation and survival of lung cancers with EGFR mutation solely depend on aberrant signalling from the mutated EGFR, these tumours often show dramatic responses to EGFR tyrosine kinase inhibitors (TKIs). However, acquiring resistance to these drugs is almost inevitable, thus a better understanding of the underlying resistance mechanisms is critical. Small cell lung cancer (SCLC) transformat...

  17. News in the studies of multidrug resistance of breast cancer cells

    Directory of Open Access Journals (Sweden)

    A. A. Stavrovskaya

    2015-06-01

    Full Text Available Breast cancer (BC is the most common cancer among women in Russia. One of the main treatment methods of BC is systemic chemotherapy. Multidrug resistance of tumor cells (MDR is the important hindrance on the way to successful chemotherapy. The new data concerning molecular mechanisms of MDR will be presented in this review. The recent data concerning some new biological prognostic markers will be also discussed. There are data showing that transporters of ABC family (ABC transporters influence tumor progression not only by MDR induction but also by the influence on the traits of malignancy in tumor cells. The results of the studies of ABC transporters, participation in the processes of accumulation of tumor stem cells under the influence of chemotherapy will be discussed. The problem of the participation of ABC transporters in the phenomenon of influence of PI3K/AKT/PTEN signal transduction pathway on the MDR regulation is discussed. The results of the studies of the role of microRNA deregulation in breast cancer drug resistance as well as studies of some epigenetic mechanisms of MDR regulation will be considered. Protein phosphatase 2A (PP2A, serine/threonine phosphatase, PTK7 (protein tyrosine kinase 7. fascin (an actin bundling cytoskeletal protein multifunctional YB-1 protein will considered as new BC prognostic markers. The perspectives of MDR studies will be discussed as well.

  18. Cholesterol biosynthesis inhibitor RO 48-8071 suppresses growth of hormone-dependent and castration-resistant prostate cancer cells

    Directory of Open Access Journals (Sweden)

    Liang Y

    2016-05-01

    Full Text Available Yayun Liang,1 Benford Mafuvadze,1 Johannes D Aebi,2 Salman M Hyder1 1Dalton Cardiovascular Research Center and Department of Biomedical Sciences, University of Missouri-Columbia, Columbia, MO, USA; 2Medicinal Chemistry, Roche Pharma Research and Early Development (pRED, Roche Innovation Center Basel, F Hoffmann-La Roche Ltd., Basel, Switzerland Abstract: Standard treatment for primary prostate cancer includes systemic exposure to chemotherapeutic drugs that target androgen receptor or antihormone therapy (chemical castration; however, drug-resistant cancer cells generally emerge during treatment, limiting the continued use of systemic chemotherapy. Patients are then treated with more toxic standard therapies. Therefore, there is an urgent need for novel and more effective treatments for prostate cancer. The cholesterol biosynthetic pathway is an attractive therapeutic target for treating endocrine-dependent cancers because cholesterol is an essential structural and functional component of cell membranes as well as the metabolic precursor of endogenous steroid hormones. In this study, we have examined the effects of RO 48-8071 (4'-[6-(allylmethylaminohexyloxy]-4-bromo-2'-fluorobenzophenone fumarate; Roche Pharmaceuticals internal reference: RO0488071 (RO, which is an inhibitor of 2, 3-oxidosqualene cyclase (a key enzyme in the cholesterol biosynthetic pathway, on prostate cancer cells. Exposure of both hormone-dependent and castration-resistant human prostate cancer cells to RO reduced prostate cancer cell viability and induced apoptosis in vitro. RO treatment reduced androgen receptor protein expression in hormone-dependent prostate cancer cells and increased estrogen receptor β (ERβ protein expression in both hormone-dependent and castration-resistant prostate cancer cell lines. Combining RO with an ERβ agonist increased its ability to reduce castration-resistant prostate cancer cell viability. In addition, RO effectively suppressed the

  19. DUSP1 induces paclitaxel resistance through the regulation of p-glycoprotein expression in human ovarian cancer cells.

    Science.gov (United States)

    Kang, Yu-Seon; Seok, Hyun-Jeong; Jeong, Eun-Jeong; Kim, Yuna; Yun, Seok-Joong; Min, Jeong-Ki; Kim, Sun Jin; Kim, Jang-Seong

    2016-09-01

    The heterogeneity and genetic instability of ovarian cancer cells often lead to the development of drug resistance, closely related with the increased cancer-related mortality. In this study, we investigated the role of dual-specificity phosphatase 1 (DUSP1) in the development of the resistance in human ovarian cancer cells against paclitaxel. Overexpression of DUSP1 in HeyA8 human ovarian cancer cells (HeyA8-DUSP1) up-regulated the expression of the drug efflux pump, p-glycoprotein. Consequently, HeyA8-DUSP1 cells are highly resistant to paclitaxel, with the resistance comparable to that of a multi-drug resistance cell line (HeyA8-MDR). Moreover, over expression of DUSP1 significantly increased the activation of p38 MAPK, leaving the activation of ERK1/2 and JNK1/2 unaffected. Pharmacological suppression of p38 MAPK activity prevents the up-regulation of p-glycoprotein expression and the consequent resistance against paclitaxel in HeyA8-DUSP1 cells. By contrast, HeyA8-MDR cells expressed a significantly higher level of DUSP1, but treatment with small interference RNA against DUSP1 significantly suppressed the expression of p-glycoprotein and the resistance against paclitaxel in HeyA8-MDR cells. Ectopic expression of MKK3, an upstream activator of p38 MAPK, significantly up-regulated the expression of p-glycoprotein and increased the consequent resistance against paclitaxel in HeyA8 cells. Collectively, these data indicated that DUSP1 may induce the resistance against paclitaxel through the p38 MAPK-mediated overexpression of p-glycoprotein in human ovarian cancer cells. PMID:27422607

  20. Targeting AKT with the allosteric AKT inhibitor MK-2206 in non-small cell lung cancer cells with acquired resistance to cetuximab

    OpenAIRE

    Iida, Mari; Brand, Toni M; Campbell, David A; Starr, Megan M.; Luthar, Neha; Traynor, Anne M.; Wheeler, Deric L

    2013-01-01

    The epidermal growth factor receptor (EGFR) is a central regulator of tumor progression in human cancers. Cetuximab is an anti-EGFR monoclonal antibody that has been approved for use in oncology. Despite clinical success the majority of patients do not respond to cetuximab and those who initially respond frequently acquire resistance. To understand how tumor cells acquire resistance to cetuximab we developed a model of resistance using the non-small cell lung cancer line NCI-H226. We found th...

  1. Magnetic fluid hyperthermia enhances cytotoxicity of bortezomib in sensitive and resistant cancer cell lines

    Directory of Open Access Journals (Sweden)

    Alvarez-Berríos MP

    2013-12-01

    Full Text Available Merlis P Alvarez-Berríos,1 Amalchi Castillo,1 Carlos Rinaldi,1–3 Madeline Torres-Lugo1 1Department of Chemical Engineering, University of Puerto Rico, Mayagüez, Puerto Rico; 2J Crayton Pruitt Family Department of Biomedical Engineering, 3Department of Chemical Engineering, University of Florida, Gainesville, FL, USA Abstract: The proteasome inhibitor bortezomib (BZ has shown promising results in some types of cancer, but in others it has had minimal activity. Recent studies have reported enhanced efficacy of BZ when combined with hyperthermia. However, the use of magnetic nanoparticles to induce hyperthermia in combination with BZ has not been reported. This novel hyperthermia modality has shown better potentiation of chemotherapeutics over other types of hyperthermia. We hypothesized that inducing hyperthermia via magnetic nanoparticles (MFH would enhance the cytotoxicity of BZ in BZ-sensitive and BZ-resistant cancer cells more effectively than hyperthermia using a hot water bath (HWH. Studies were conducted using BZ in combination with MFH in two BZ-sensitive cell lines (MDA-MB-468, Caco-2, and one BZ-resistant cell line (A2780 at two different conditions, ie, 43°C for 30 minutes and 45°C for 30 minutes. These experiments were compared with combined application of HWH and BZ. The results indicate enhanced potentiation between hyperthermic treatment and BZ. MFH combined with BZ induced cytotoxicity in sensitive and resistant cell lines to a greater extent than HWH under the same treatment conditions. The observation that MFH sensitizes BZ-resistant cell lines makes this approach a potentially effective anticancer therapy platform. Keywords: magnetic fluid hyperthermia, hot water hyperthermia, BZ, enhanced cytotoxicity, thermal sensitization

  2. Isolation and genomic analysis of circulating tumor cells from castration resistant metastatic prostate cancer

    International Nuclear Information System (INIS)

    The number of circulating tumor cells (CTCs) in metastatic prostate cancer patients provides prognostic and predictive information. However, it is the molecular characterization of CTCs that offers insight into the biology of these tumor cells in the context of personalized treatment. We developed a novel approach to isolate CTCs away from hematopoietic cells with high purity, enabling genomic analysis of these cells. The isolation protocol involves immunomagnetic enrichment followed by fluorescence activated cell sorting (IE/FACS). To evaluate the feasibility of isolation of CTCs by IE/FACS and downstream genomic profiling, we conducted a pilot study in patients with metastatic castration resistant prostate cancer (CRPC). Twenty (20) sequential CRPC patients were assayed using CellSearch™. Twelve (12) patients positive for CTCs were subjected to immunomagnetic enrichment and fluorescence activated cell sorting (IE/FACS) to isolate CTCs. Genomic DNA of CTCs was subjected to whole genome amplification (WGA) followed by gene copy number analysis via array comparative genomic hybridization (aCGH). CTCs from nine (9) patients successfully profiled were observed to have multiple copy number aberrations including those previously reported in primary prostate tumors such as gains in 8q and losses in 8p. High-level copy number gains at the androgen receptor (AR) locus were observed in 7 (78%) cases. Comparison of genomic profiles between CTCs and archival primary tumors from the same patients revealed common lineage. However, high-level copy number gains in the AR locus were observed in CTCs, but not in the matched archival primary tumors. We developed a new approach to isolate prostate CTCs without significant leukocyte admixture, and to subject them to genome-wide copy number analysis. Our assay may be utilized to explore genomic events involved in cancer progression, e.g. development of castration resistance and to monitor therapeutic efficacy of targeted therapies in

  3. Colorectal cancer cell lines made resistant to SN38-and Oxaliplatin: Roles of altered ion transporter function in resistance?

    DEFF Research Database (Denmark)

    Sandra, Christensen; Jensen, Niels Frank; Stoeckel, Johanne Danmark;

    2013-01-01

    Colorectal cancer (CRC) is the 3rd most common cancer globally, with 5year survival rates of ~50%. Response rates to standard treatments (irinotecan (SN38) or Oxaliplatin (Oxp)) are 31–56% and drug resistance is a major problem. Thus, we established in vitro CRC models to investigate SN38 and Oxp...... not previously been implicated in SN38 or Oxp resistance and are generally restricted to the CNS, they are potential novel biomarkers for resistance and interesting candidates for therapeutic targeting....

  4. Natural lignans from Arctium lappa modulate P-glycoprotein efflux function in multidrug resistant cancer cells.

    Science.gov (United States)

    Su, Shan; Cheng, Xinlai; Wink, Michael

    2015-02-15

    Arctium lappa is a well-known traditional medicinal plant in China (TCM) and Europe that has been used for thousands of years to treat arthritis, baldness or cancer. The plant produces lignans as secondary metabolites which have a wide range of bioactivities. Yet, their ability to reverse multidrug resistance (MDR) in cancer cells has not been explored. In this study, we isolated six lignans from A. lappa seeds, namely arctigenin, matairesinol, arctiin, (iso)lappaol A, lappaol C, and lappaol F. The MDR reversal potential of the isolated lignans and the underlying mechanism of action were studied using two MDR cancer cell lines, CaCo2 and CEM/ADR 5000 which overexpress P-gp and other ABC transporters. In two-drug combinations of lignans with the cytotoxic doxorubicin, all lignans exhibited synergistic effects in CaCo2 cells and matairesinol, arctiin, lappaol C and lappaol F display synergistic activity in CEM/ADR 5000 cells. Additionally, in three-drug combinations of lignans with the saponin digitonin and doxorubicin MDR reversal activity was even stronger enhanced. The lignans can increase the retention of the P-gp substrate rhodamine 123 in CEM/ADR 5000 cells, indicating that lignans can inhibit the activity of P-gp. Our study provides a first insight into the potential chemosensitizing activity of a series of natural lignans, which might be candidates for developing novel adjuvant anticancer agents. PMID:25765837

  5. Surface TRAIL decoy receptor-4 expression is correlated with TRAIL resistance in MCF7 breast cancer cells

    International Nuclear Information System (INIS)

    Tumor Necrosis Factor (TNF)-Related Apoptosis-Inducing Ligand (TRAIL) selectively induces apoptosis in cancer cells but not in normal cells. Despite this promising feature, TRAIL resistance observed in cancer cells seriously challenged the use of TRAIL as a death ligand in gene therapy. The current dispute concerns whether or not TRAIL receptor expression pattern is the primary determinant of TRAIL sensitivity in cancer cells. This study investigates TRAIL receptor expression pattern and its connection to TRAIL resistance in breast cancer cells. In addition, a DcR2 siRNA approach and a complementary gene therapy modality involving IKK inhibition (AdIKKβKA) were also tested to verify if these approaches could sensitize MCF7 breast cancer cells to adenovirus delivery of TRAIL (Ad5hTRAIL). TRAIL sensitivity assays were conducted using Molecular Probe's Live/Dead Cellular Viability/Cytotoxicity Kit following the infection of breast cancer cells with Ad5hTRAIL. The molecular mechanism of TRAIL induced cell death under the setting of IKK inhibition was revealed by Annexin V binding. Novel quantitative Real Time RT-PCR and flow cytometry analysis were performed to disclose TRAIL receptor composition in breast cancer cells. MCF7 but not MDA-MB-231 breast cancer cells displayed strong resistance to adenovirus delivery of TRAIL. Only the combinatorial use of Ad5hTRAIL and AdIKKβKA infection sensitized MCF7 breast cancer cells to TRAIL induced cell death. Moreover, novel quantitative Real Time RT-PCR assays suggested that while the level of TRAIL Decoy Receptor-4 (TRAIL-R4) expression was the highest in MCF7 cells, it was the lowest TRAIL receptor expressed in MDA-MB-231 cells. In addition, conventional flow cytometry analysis demonstrated that TRAIL resistant MCF7 cells exhibited substantial levels of TRAIL-R4 expression but not TRAIL decoy receptor-3 (TRAIL-R3) on surface. On the contrary, TRAIL sensitive MDA-MB-231 cells displayed very low levels of surface TRAIL-R4

  6. Surface TRAIL decoy receptor-4 expression is correlated with TRAIL resistance in MCF7 breast cancer cells

    Directory of Open Access Journals (Sweden)

    Aydin Cigdem

    2005-05-01

    Full Text Available Abstract Background Tumor Necrosis Factor (TNF-Related Apoptosis-Inducing Ligand (TRAIL selectively induces apoptosis in cancer cells but not in normal cells. Despite this promising feature, TRAIL resistance observed in cancer cells seriously challenged the use of TRAIL as a death ligand in gene therapy. The current dispute concerns whether or not TRAIL receptor expression pattern is the primary determinant of TRAIL sensitivity in cancer cells. This study investigates TRAIL receptor expression pattern and its connection to TRAIL resistance in breast cancer cells. In addition, a DcR2 siRNA approach and a complementary gene therapy modality involving IKK inhibition (AdIKKβKA were also tested to verify if these approaches could sensitize MCF7 breast cancer cells to adenovirus delivery of TRAIL (Ad5hTRAIL. Methods TRAIL sensitivity assays were conducted using Molecular Probe's Live/Dead Cellular Viability/Cytotoxicity Kit following the infection of breast cancer cells with Ad5hTRAIL. The molecular mechanism of TRAIL induced cell death under the setting of IKK inhibition was revealed by Annexin V binding. Novel quantitative Real Time RT-PCR and flow cytometry analysis were performed to disclose TRAIL receptor composition in breast cancer cells. Results MCF7 but not MDA-MB-231 breast cancer cells displayed strong resistance to adenovirus delivery of TRAIL. Only the combinatorial use of Ad5hTRAIL and AdIKKβKA infection sensitized MCF7 breast cancer cells to TRAIL induced cell death. Moreover, novel quantitative Real Time RT-PCR assays suggested that while the level of TRAIL Decoy Receptor-4 (TRAIL-R4 expression was the highest in MCF7 cells, it was the lowest TRAIL receptor expressed in MDA-MB-231 cells. In addition, conventional flow cytometry analysis demonstrated that TRAIL resistant MCF7 cells exhibited substantial levels of TRAIL-R4 expression but not TRAIL decoy receptor-3 (TRAIL-R3 on surface. On the contrary, TRAIL sensitive MDA-MB-231 cells

  7. Quantitative proteomics as a tool to identify resistance mechanisms in erlotinib-resistant subclones of the non-small cell lung cancer cell line HCC827

    DEFF Research Database (Denmark)

    Jacobsen, Kirstine

    identification of novel resistance mechanisms. We identified 2875 cytoplasmic proteins present in all 4 cell lines. Of these 87, 56 and 23 are upregulated >1.5 fold; and 117, 72 and 32 are downregulated >1.5 fold, respectively, in the 3 resistant clones compared to the parental cell line. By network analysis, we...... downregulated, indicating a bypass signaling mechanism to achieve resistance. More specifically, mitogen-activated protein kinase 1 (MAPK1) and synovial apoptosis inhibitor 1 (SYNV1) were upregulated. Conclusions: In conclusion, cancer-related networks such as proliferation and apoptosis were found to be...... regulated, supporting the validity of the model. EGFR was consistently downregulated and MAPK1 activated, indicating a bypass resistance mechanism, likely leading to activation of downstream proteins obviating EGFR. Generally, the overlap of regulated proteins between the 3 subclones was low, indicating the...

  8. Characterization of DNA topoisomerase I in three SN-38 resistant human colon cancer cell lines reveals a new pair of resistance-associated mutations

    OpenAIRE

    Jensen, Niels Frank; Agama, Keli; Roy, Amit; Smith, David Hersi; Pfister, Thomas D.; Rømer, Maria Unni; Zhang, Hong-Liang; Doroshow, James H.; Knudsen, Birgitta R.; Stenvang, Jan; Brünner, Nils; Pommier, Yves

    2016-01-01

    Background DNA topoisomerase I (Top1) is a DNA unwinding protein and the specific target of the camptothecin class of chemotherapeutic drugs. One of these, irinotecan, acting through its active metabolite SN-38, is used in the treatment of metastatic colorectal cancer. However, resistance to irinotecan represents a major clinical problem. Since molecular alterations in Top1 may result in resistance to irinotecan, we characterized Top1 in three human colon cancer cell lines with acquired resis...

  9. Loperamide, an FDA-Approved Antidiarrhea Drug, Effectively Reverses the Resistance of Multidrug Resistant MCF-7/MDR1 Human Breast Cancer Cells to Doxorubicin-Induced Cytotoxicity

    OpenAIRE

    Zhou, Yanfei; Sridhar, Rajagopalan; Shan, Liang; Sha, Wei; Gu, Xinbin; Sukumar, Saraswati

    2011-01-01

    Loperamide is an FDA-approved antidiarrhea drug which acts on the μ-opioid receptors in the mesenteric plexus of large intestine and exhibits limited side effects. We hypothesized that loperamide might reverse the multidrug resistance (MDR) of human cancer cells to chemotherapeutic agents. MCF-7/MDR1 cells express high level of MDR1 and are resistant to doxorubicin. We found that loperamide significantly enhanced the cytotoxicity of doxorubicin to MCF-7/MDR1 cells in a dose-dependent manner. ...

  10. Long-term persistence of acquired resistance to 5-fluorouracil in the colon cancer cell line SW620

    International Nuclear Information System (INIS)

    Treatment resistance to antineoplastic drugs represents a major clinical problem. Here, we investigated the long-term stability of acquired resistance to 5-fluorouracil (FU) in an in vitro colon cancer model, using four sub-clones characterised by increasing FU-resistance derived from the cell line SW620. The resistance phenotype was preserved after FU withdrawal for 15 weeks (∼ 100 cell divisions) independent of the established level of drug resistance and of epigenetic silencing. Remarkably, resistant clones tolerated serum deprivation, adopted a CD133+ CD44- phenotype, and further exhibited loss of membrane-bound E-cadherin together with predominant nuclear β-catenin localisation. Thus, we provide evidence for a long-term memory of acquired drug resistance, driven by multiple cellular strategies (epithelial-mesenchymal transition and selective propagation of CD133+ cells). These resistance phenomena, in turn, accentuate the malignant phenotype.

  11. Long-term persistence of acquired resistance to 5-fluorouracil in the colon cancer cell line SW620

    Energy Technology Data Exchange (ETDEWEB)

    Tentes, I.K., E-mail: itentes@med.duth.gr [Department of Biochemistry, Medical School, Democritus University of Thrace, 6th km Alexandroupolis-Komotini (Dragana), 68100 Alexandroupolis (Greece); Schmidt, W.M. [Center for Anatomy and Cell Biology, Waehringer Strasse 13, 1090 Vienna (Austria); Krupitza, G. [Institute of Clinical Pathology, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna (Austria); Steger, G.G.; Mikulits, W. [Department of Medicine I, Medical University of Vienna, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna (Austria); Kortsaris, A. [Department of Biochemistry, Medical School, Democritus University of Thrace, 6th km Alexandroupolis-Komotini (Dragana), 68100 Alexandroupolis (Greece); Mader, R.M. [Department of Medicine I, Medical University of Vienna, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna (Austria)

    2010-11-15

    Treatment resistance to antineoplastic drugs represents a major clinical problem. Here, we investigated the long-term stability of acquired resistance to 5-fluorouracil (FU) in an in vitro colon cancer model, using four sub-clones characterised by increasing FU-resistance derived from the cell line SW620. The resistance phenotype was preserved after FU withdrawal for 15 weeks ({approx} 100 cell divisions) independent of the established level of drug resistance and of epigenetic silencing. Remarkably, resistant clones tolerated serum deprivation, adopted a CD133{sup +} CD44{sup -} phenotype, and further exhibited loss of membrane-bound E-cadherin together with predominant nuclear {beta}-catenin localisation. Thus, we provide evidence for a long-term memory of acquired drug resistance, driven by multiple cellular strategies (epithelial-mesenchymal transition and selective propagation of CD133{sup +} cells). These resistance phenomena, in turn, accentuate the malignant phenotype.

  12. MicroRNA-320a sensitizes tamoxifen-resistant breast cancer cells to tamoxifen by targeting ARPP-19 and ERRγ*

    OpenAIRE

    Mingrong Lü; Keshuo Ding; Guofeng Zhang; Mianmian Yin; Guidong Yao; Hui Tian; Jie Lian; Lin Liu; Meng Liang; Tao Zhu; Fei Sun

    2015-01-01

    Tamoxifen represents a major adjuvant therapy to those patients with estrogen receptor-alpha positive breast cancer. However, tamoxifen resistance occurs quite often, either de novo or acquired during treatment. To investigate the role of miR-320a in the development of resistance to tamoxifen, we established tamoxifen-resistant (TamR) models by continually exposing MCF-7 or T47D breast cancer cells to tamoxifen, and identified microRNA(miRNA)-320a as a down-regulated miRNA in tamoxifen resist...

  13. Deep sequencing identifies deregulation of microRNAs involved with vincristine drug-resistance of colon cancer cells

    OpenAIRE

    Dong, Wei-Hua; Li, Qin; Zhang, Xiao-Yan; Guo, Qing; Li, Huizheng; Wang, Tian-Yun

    2015-01-01

    Background: Vincristine (VCR) is a chemical that is widely used in tumor therapy. While long-term use can make tumor cells resistant to VCR, the underlying mechanisms of this resistance are still unclear. Objective: This study aimed at investigating the role of microRNA (miRNA) in colon cancer drug resistance. Methods: HCT-8 colon carcinoma cells were cultured and treated with different VCR concentrations to establish an HCT-8/VCR resistant cell line. Whole-genome screens, HiSeq 2500 sequenci...

  14. The cellular uptake mechanism, intracellular transportation, and exocytosis of polyamidoamine dendrimers in multidrug-resistant breast cancer cells.

    Science.gov (United States)

    Zhang, Jie; Liu, Dan; Zhang, Mengjun; Sun, Yuqi; Zhang, Xiaojun; Guan, Guannan; Zhao, Xiuli; Qiao, Mingxi; Chen, Dawei; Hu, Haiyang

    2016-01-01

    Polyamidoamine dendrimers, which can deliver drugs and genetic materials to resistant cells, are attracting increased research attention, but their transportation behavior in resistant cells remains unclear. In this paper, we performed a systematic analysis of the cellular uptake, intracellular transportation, and efflux of PAMAM-NH2 dendrimers in multidrug-resistant breast cancer cells (MCF-7/ADR cells) using sensitive breast cancer cells (MCF-7 cells) as the control. We found that the uptake rate of PAMAM-NH2 was much lower and exocytosis of PAMAM-NH2 was much greater in MCF-7/ADR cells than in MCF-7 cells due to the elimination of PAMAM-NH2 from P-glycoprotein and the multidrug resistance-associated protein in MCF-7/ADR cells. Macropinocytosis played a more important role in its uptake in MCF-7/ADR cells than in MCF-7 cells. PAMAM-NH2 aggregated and became more degraded in the lysosomal vesicles of the MCF-7/ADR cells than in those of the MCF-7 cells. The endoplasmic reticulum and Golgi complex were found to participate in the exocytosis rather than endocytosis process of PAMAM-NH2 in both types of cells. Our findings clearly showed the intracellular transportation process of PAMAM-NH2 in MCF-7/ADR cells and provided a guide of using PAMAM-NH2 as a drug and gene vector in resistant cells. PMID:27536106

  15. Sweat but no gain: inhibiting proliferation of multidrug resistant cancer cells with "ersatzdroges".

    Science.gov (United States)

    Kam, Yoonseok; Das, Tuhin; Tian, Haibin; Foroutan, Parastou; Ruiz, Epifanio; Martinez, Gary; Minton, Susan; Gillies, Robert J; Gatenby, Robert A

    2015-02-15

    ATP-binding cassette (ABC) drug transporters consuming ATPs for drug efflux is a common mechanism by which clinical cancers develop multidrug resistance (MDR). We hypothesized that MDR phenotypes could be suppressed by administration of "ersatzdroges," nonchemotherapy drugs that are, nevertheless, ABC substrates. We reasoned that, through prolonged activation of the ABC pumps, ersatzdroges will force MDR cells to divert limited resources from proliferation and invasion thus delaying disease progression. We evaluated ABC substrates as ersatzdroge by comparing their effects on proliferation and survival of MDR cell lines (MCF-7/Dox and 8226/Dox40) with the effects on the drug-sensitive parental lines (MCF-7 and 8226/s, respectively) in glucose-limited condition. The changes in glucose and energy demands were also examined in vitro and in vivo. MCF-7/Dox showed higher ATP demand and susceptibility to glucose resource limitation. Ersatzdroges significantly decreased proliferation of MCF-7/Dox when the culture media contained physiological glucose concentrations (1.0 g/L) or less, but had no effect on MCF-7. Similar evidence was obtained from 8226/Dox40 and 8226/s comparison. In vivo 18F-FDG-PET imaging demonstrated that glucose uptake was increased by systemic administration of an ersatzdroge in tumors composed of MDR. These results suggest that administration of ersatzdroges, by increasing the metabolic cost of resistance, can suppress proliferation of drug-resistance phenotypes. This provides a novel and relatively simple application model of evolution-based strategy, which can exploit the cost of resistance to delay proliferation of drug-resistant cancer phenotypes. Furthermore, suggested is the potential of ersatzdroges to identify tumors or regions of tumors that express the MDR phenotype. PMID:25156304

  16. Sweat but no gain: Inhibiting proliferation of multidrug resistant cancer cells with “Ersatzdroges”

    Science.gov (United States)

    Kam, Yoonseok; Das, Tuhin; Tian, Haibin; Foroutan, Parastou; Ruiz, Epifanio; Martinez, Gary; Minton, Susan; Gillies, Robert J.; Gatenby, Robert A.

    2014-01-01

    ATP-binding cassette (ABC) drug transporters consuming ATPs for drug efflux is a common mechanism by which clinical cancers develop multidrug resistance (MDR). We hypothesized that MDR phenotypes could be suppressed by administration of “ersatzdroges”, non-chemotherapy drugs that are, nevertheless, ABC substrates. We reasoned that, through prolonged activation of the ABC pumps, ersatzdroges will force MDR cells to divert limited resources from proliferation and invasion thus delaying disease progression. We evaluated ABC substrates as ersatzdroge by comparing their effects on proliferation and survival of MDR cell lines (MCF-7/Dox and 8226/Dox40) with the effects on the drug-sensitive parental lines (MCF-7 and 8226/s, respectively) in glucose-limited condition. The changes in glucose and energy demands were also examined in vitro and in vivo. MCF-7/Dox showed higher ATP demand and susceptibility to glucose resource limitation. Ersatzdroges significantly decreased proliferation of MCF-7/Dox when the culture media contained physiological glucose concentrations (1.0 g/L) or less, but had no effect on MCF-7. Similar evidence was obtained from 8226/Dox40 and 8226/s comparison. In vivo 18F-FDG-PET imaging demonstrated that glucose uptake was increased by systemic administration of an ersatzdroge in tumors composed of MDR. These results suggest that administration of ersatzdroges, by increasing the metabolic cost of resistance, can suppress proliferation of drug-resistance phenotypes. This provides a novel and relatively simple application model of evolution-based strategy which can exploit the cost of resistance to delay proliferation of drug-resistant cancer phenotypes. Furthermore, suggested is the potential of ersatzdroges to identify tumors or regions of tumors that express the MDR phenotype. PMID:25156304

  17. Extraction and identification of exosomes from drug-resistant breast cancer cells and their potential role in cell-to-cell drug-resistance transfer

    Institute of Scientific and Technical Information of China (English)

    许金金

    2014-01-01

    Objective To explore whether docetaxel-resistant cells(MCF-7/Doc)and doxorubicin-resistant cells(MCF-7/ADM)can secrete Exosomes and their potential role in cell-cell drug-resistance transfer.Methods Exosomes were extracted from the cell culture supernatants of MCF-7/Doc and MCF-7/ADM cells by fractionation ultracentrifugation,and were identified by transmission

  18. AZD9291 in epidermal growth factor receptor inhibitor—resistant non-small-cell lung cancer

    OpenAIRE

    Stinchcombe, Thomas E.

    2016-01-01

    Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in advanced EGFR mutant non-small cell lung cancer have an objective response rate (ORR) of approximately 60–70% and a median progression free-survival (PFS) of approximately 10-13 months. Studies of tumor biopsies performed after progression on EGFR TKI revealed that 50-60% of EGFR mutant NSCLC developed an EGFR exon 20 T790M mutation as a mechanism of acquired resistance. AZD9291 is a third generation irreversible EGF...

  19. Multidrug resistance reversal and apoptosis induction in human colon cancer cells by some flavonoids present in citrus plants.

    Science.gov (United States)

    Wesołowska, Olga; Wiśniewski, Jerzy; Sroda-Pomianek, Kamila; Bielawska-Pohl, Aleksandra; Paprocka, Maria; Duś, Danuta; Duarte, Noélia; Ferreira, Maria-José U; Michalak, Krystyna

    2012-11-26

    Multidrug resistance (MDR) of cancer cells constitutes one of the main reasons for chemotherapy failure. The search for nontoxic modulators that reduce MDR is a task of great importance. An ability to enhance apoptosis of resistant cells would also be beneficial. In the present study, the MDR reversal and apoptosis-inducing potency of three flavonoids produced by Citrus plants, namely, naringenin (1a), aromadendrin (2), and tangeretin (3), and the methylated naringenin derivatives (1b, 1c), have been studied in sensitive (LoVo) and multidrug-resistant (LoVo/Dx) human colon adenocarcinoma cells. Cytotoxicity of methoxylated flavonoids was higher as compared to hydroxylated analogues. Only 3 turned out to inhibit P-glycoprotein, as demonstrated by a rhodamine 123 accumulation assay. It also increased doxorubicin accumulation in LoVo/Dx cells and enabled doxorubicin to enter cellular nuclei. In addition, 3 was found to be an effective MDR modulator in resistant cells by sensitizing them to doxorubicin. Tangeretin-induced caspase-3 activation and elevated surface phosphatidylserine exposure demonstrated its apoptosis-inducing activity in LoVo/Dx cells, while the other flavonoids evaluated were not active. Additionally, 3 was more toxic to resistant rather than to sensitive cancer cells. Its apoptosis-inducing activity was also higher in LoVo/Dx than in LoVo cells. It was concluded that the activity of 3 against multidrug-resistant cancer cells may be enhanced by its apoptosis-inducing activity. PMID:23137376

  20. Production of interleukin‑4 in CD133+ cervical cancer stem cells promotes resistance to apoptosis and initiates tumor growth.

    Science.gov (United States)

    Liu, Chun-Tao; Xin, Ying; Tong, Chun-Yan; Li, Bing; Bao, Hong-Li; Zhang, Cai-Yun; Wang, Xue-Hui

    2016-06-01

    The cancer stem cell (CSC) theory suggests that cancer growth and invasion is dictated by the small population of CSCs within the heterogenous tumor. The aim of the present study was to elucidate the cause for chemotherapy failure and the resistance of CSCs to apoptosis. A total of ~2.3% cluster of differentiation (CD)133+ cancer stem‑like side population (SP) cells were identified in cases of uterine cervical cancer. These CD133+ SP cells were found to potently initiate tumor growth and invasion, as they exhibit transcriptional upregulation of stemness genes, including octamer‑binding transcription factor‑4, B‑cell‑specific Moloney murine leukemia virus insertion site‑1, epithelial cell adhesion molecule, (sex determining region Y)‑box 2, Nestin and anti‑apoptotic B cell lymphoma‑2. In addition, the CD133+ SP cells showed resistance to multi‑drug treatment and apoptosis. The present study further showed that the secretion of interleukin‑4 (IL‑4) in CD133+ cervical cancer SP cells promoted cell proliferation and prevented the SP cells from apoptosis. Following the neutralization of IL‑4 with anti‑IL‑4 antibody, the CD133+ SP cells were more sensitive to drug treatment and apoptosis. Therefore, the data obtained in the present study suggested that the autocrine secretion of IL‑4 promotes increased survival and resistance to cell death in CSCs. PMID:27121303

  1. miR-193b Modulates Resistance to Doxorubicin in Human Breast Cancer Cells by Downregulating MCL-1

    Directory of Open Access Journals (Sweden)

    Jingpei Long

    2015-01-01

    Full Text Available MicroRNAs (miRNAs family, which is involved in cancer development, proliferation, apoptosis, and drug resistance, is a group of noncoding RNAs that modulate the expression of oncogenes and antioncogenes. Doxorubicin is an active cytotoxic agent for breast cancer treatment, but the acquisition of doxorubicin resistance is a common and critical limitation to cancer therapy. The aim of this study was to investigate whether miR-193b mediated the resistance of breast cancer cells to doxorubicin by targeting myeloid cell leukemia-1 (MCL-1. In this study, we found that miR-193b levels were significantly lower in doxorubicin-resistant MCF-7 (MCF-7/DOXR cells than in the parental MCF-7 cells. We observed that exogenous miR-193b significantly suppressed the ability of MCF-7/DOXR cells to resist doxorubicin. It demonstrated that miR-193b directly targeted MCL-1 3′-UTR (3′-Untranslated Regions. Further studies indicated that miR-193b sensitized MCF-7/DOXR cells to doxorubicin through a mechanism involving the downregulation of MCL-1. Together, our findings provide evidence that the modulation of miR-193b may represent a novel therapeutic target for the treatment of breast cancer.

  2. The redox state of cytochrome c modulates resistance to methotrexate in human MCF7 breast cancer cells.

    Directory of Open Access Journals (Sweden)

    Susana Barros

    Full Text Available BACKGROUND: Methotrexate is a chemotherapeutic agent used to treat a variety of cancers. However, the occurrence of resistance limits its effectiveness. Cytochrome c in its reduced state is less capable of triggering the apoptotic cascade. Thus, we set up to study the relationship among redox state of cytochrome c, apoptosis and the development of resistance to methotrexate in MCF7 human breast cancer cells. RESULTS: Cell incubation with cytochrome c-reducing agents, such as tetramethylphenylenediamine, ascorbate or reduced glutathione, decreased the mortality and apoptosis triggered by methotrexate. Conversely, depletion of glutathione increased the apoptotic action of methotrexate, showing an involvement of cytochrome c redox state in methotrexate-induced apoptosis. Methotrexate-resistant MCF7 cells showed increased levels of endogenous reduced glutathione and a higher capability to reduce exogenous cytochrome c. Using functional genomics we detected the overexpression of GSTM1 and GSTM4 in methotrexate-resistant MCF7 breast cancer cells, and determined that methotrexate was susceptible of glutathionylation by GSTs. The inhibition of these GSTM isoforms caused an increase in methotrexate cytotoxicity in sensitive and resistant cells. CONCLUSIONS: We conclude that overexpression of specific GSTMs, GSTM1 and GSTM4, together with increased endogenous reduced glutathione levels help to maintain a more reduced state of cytochrome c which, in turn, would decrease apoptosis, thus contributing to methotrexate resistance in human MCF7 breast cancer cells.

  3. Fallopia japonica, a Natural Modulator, Can Overcome Multidrug Resistance in Cancer Cells.

    Science.gov (United States)

    Eid, Safaa Yehia; El-Readi, Mahmoud Zaki; Ashour, Mohamed Lotfy; Wink, Michael

    2015-01-01

    Resistance of cancer cells to chemotherapy is controlled by the decrease of intracellular drug accumulation, increase of detoxification, and diminished propensity of cancer cells to undergo apoptosis. ATP-binding cassette (ABC) membrane transporters with intracellular metabolic enzymes contribute to the complex and unresolved phenomenon of multidrug resistance (MDR). Natural products as alternative medicine have great potential to discover new MDR inhibitors with diverse modes of action. In this study, we characterized several extracts of traditional Chinese medicine (TCM) plants (N = 16) for their interaction with ABC transporters, cytochrome P3A4 (CYP3A4), and glutathione-S-transferase (GST) activities and their cytotoxic effect on different cancer cell lines. Fallopia japonica (FJ) (Polygonaceae) shows potent inhibitory effect on CYP3A4 P-glycoprotein activity about 1.8-fold when compared to verapamil as positive control. FJ shows significant inhibitory effect (39.81%) compared with the known inhibitor ketoconazole and 100 μg/mL inhibited GST activity to 14 μmol/min/mL. FJ shows moderate cytotoxicity in human Caco-2, HepG-2, and HeLa cell lines; IC50 values were 630.98, 198.80, and 317.37 µg/mL, respectively. LC-ESI-MS were used to identify and quantify the most abundant compounds, emodin, polydatin, and resveratrol, in the most active extract of FJ. Here, we present the prospect of using Fallopia japonica as natural products to modulate the function of ABC drug transporters. We are conducting future study to evaluate the ability of the major active secondary metabolites of Fallopia japonica to modulate MDR and their impact in case of failure of chemotherapy. PMID:26346937

  4. Fallopia japonica, a Natural Modulator, Can Overcome Multidrug Resistance in Cancer Cells

    Directory of Open Access Journals (Sweden)

    Safaa Yehia Eid

    2015-01-01

    Full Text Available Resistance of cancer cells to chemotherapy is controlled by the decrease of intracellular drug accumulation, increase of detoxification, and diminished propensity of cancer cells to undergo apoptosis. ATP-binding cassette (ABC membrane transporters with intracellular metabolic enzymes contribute to the complex and unresolved phenomenon of multidrug resistance (MDR. Natural products as alternative medicine have great potential to discover new MDR inhibitors with diverse modes of action. In this study, we characterized several extracts of traditional Chinese medicine (TCM plants (N = 16 for their interaction with ABC transporters, cytochrome P3A4 (CYP3A4, and glutathione-S-transferase (GST activities and their cytotoxic effect on different cancer cell lines. Fallopia japonica (FJ (Polygonaceae shows potent inhibitory effect on CYP3A4 P-glycoprotein activity about 1.8-fold when compared to verapamil as positive control. FJ shows significant inhibitory effect (39.81% compared with the known inhibitor ketoconazole and 100 μg/mL inhibited GST activity to 14 μmol/min/mL. FJ shows moderate cytotoxicity in human Caco-2, HepG-2, and HeLa cell lines; IC50 values were 630.98, 198.80, and 317.37 µg/mL, respectively. LC-ESI-MS were used to identify and quantify the most abundant compounds, emodin, polydatin, and resveratrol, in the most active extract of FJ. Here, we present the prospect of using Fallopia japonica as natural products to modulate the function of ABC drug transporters. We are conducting future study to evaluate the ability of the major active secondary metabolites of Fallopia japonica to modulate MDR and their impact in case of failure of chemotherapy.

  5. Role of Insulin-Like Growth Factor-1 Signaling Pathway in Cisplatin-Resistant Lung Cancer Cells

    Energy Technology Data Exchange (ETDEWEB)

    Sun Yunguang [Department of Radiation Oncology, Vanderbilt University Medical Center, Nashville, TN (United States); Zheng Siyuan [Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, TN (United States); Torossian, Artour; Speirs, Christina K.; Schleicher, Stephen; Giacalone, Nicholas J. [Department of Radiation Oncology, Vanderbilt University Medical Center, Nashville, TN (United States); Carbone, David P. [Department of Hematology and Oncology, Vanderbilt University Medical Center, Nashville, TN (United States); Zhao Zhongming, E-mail: zhongming.zhao@vanderbilt.edu [Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, TN (United States); Lu Bo, E-mail: bo.lu@vanderbilt.edu [Department of Radiation Oncology, Vanderbilt University Medical Center, Nashville, TN (United States)

    2012-03-01

    Purpose: The development of drug-resistant phenotypes has been a major obstacle to cisplatin use in non-small-cell lung cancer. We aimed to identify some of the molecular mechanisms that underlie cisplatin resistance using microarray expression analysis. Methods and Materials: H460 cells were treated with cisplatin. The differences between cisplatin-resistant lung cancer cells and parental H460 cells were studied using Western blot, MTS, and clonogenic assays, in vivo tumor implantation, and microarray analysis. The cisplatin-R cells were treated with human recombinant insulin-like growth factor (IGF) binding protein-3 and siRNA targeting IGF-1 receptor. Results: Cisplatin-R cells illustrated greater expression of the markers CD133 and aldehyde dehydrogenase, more rapid in vivo tumor growth, more resistance to cisplatin- and etoposide-induced apoptosis, and greater survival after treatment with cisplatin or radiation than the parental H460 cells. Also, cisplatin-R demonstrated decreased expression of insulin-like growth factor binding protein-3 and increased activation of IGF-1 receptor signaling compared with parental H460 cells in the presence of IGF-1. Human recombinant IGF binding protein-3 reversed cisplatin resistance in cisplatin-R cells and targeting of IGF-1 receptor using siRNA resulted in sensitization of cisplatin-R-cells to cisplatin and radiation. Conclusions: The IGF-1 signaling pathway contributes to cisplatin-R to cisplatin and radiation. Thus, this pathway represents a potential target for improved lung cancer response to treatment.

  6. Role of Insulin-Like Growth Factor-1 Signaling Pathway in Cisplatin-Resistant Lung Cancer Cells

    International Nuclear Information System (INIS)

    Purpose: The development of drug-resistant phenotypes has been a major obstacle to cisplatin use in non–small-cell lung cancer. We aimed to identify some of the molecular mechanisms that underlie cisplatin resistance using microarray expression analysis. Methods and Materials: H460 cells were treated with cisplatin. The differences between cisplatin-resistant lung cancer cells and parental H460 cells were studied using Western blot, MTS, and clonogenic assays, in vivo tumor implantation, and microarray analysis. The cisplatin-R cells were treated with human recombinant insulin-like growth factor (IGF) binding protein-3 and siRNA targeting IGF-1 receptor. Results: Cisplatin-R cells illustrated greater expression of the markers CD133 and aldehyde dehydrogenase, more rapid in vivo tumor growth, more resistance to cisplatin- and etoposide-induced apoptosis, and greater survival after treatment with cisplatin or radiation than the parental H460 cells. Also, cisplatin-R demonstrated decreased expression of insulin-like growth factor binding protein-3 and increased activation of IGF-1 receptor signaling compared with parental H460 cells in the presence of IGF-1. Human recombinant IGF binding protein-3 reversed cisplatin resistance in cisplatin-R cells and targeting of IGF-1 receptor using siRNA resulted in sensitization of cisplatin-R-cells to cisplatin and radiation. Conclusions: The IGF-1 signaling pathway contributes to cisplatin-R to cisplatin and radiation. Thus, this pathway represents a potential target for improved lung cancer response to treatment.

  7. Selective Toxicity of NSC 73306 in MDR1-positive cells as a New Strategy to Circumvent Multidrug Resistance in Cancer

    OpenAIRE

    Ludwig, Joseph A.; Szakács, Gergely; Martin, Scott E.; Chu, Benjamin F.; Cardarelli, Carol; Sauna, Zuben E.; Caplen, Natasha J.; Fales, Henry M.; Ambudkar, Suresh V.; Weinstein, John N.; Gottesman, Michael M.

    2006-01-01

    ATP-binding cassette (ABC) proteins include the best known mediators of resistance to anticancer drugs. In particular, ABCB1 (MDR1/P-gp) extrudes many types of drugs from cancer cells, thereby conferring resistance to those agents. Attempts to overcome P-gp-mediated drug resistance using specific inhibitors of P-gp has had limited success, and has faced many therapeutic challenges. As an alternative approach to using P-gp inhibitors, we characterize a thiosemicarbazone derivative (NSC73306) i...

  8. Mitochondrial localization of cyclooxygenase-2 and calcium-independent phospholipase A2 in human cancer cells: Implication in apoptosis resistance

    International Nuclear Information System (INIS)

    Cyclooxygenase-2 (COX-2) is inducible by myriad stimuli. The inducible COX-2 in primary cultured human cells has been reported to localize to nuclear envelope, endoplasmic reticulum, nucleus and caveolae. As COX-2 plays an important role in tumor growth, we were interested in its subcellular location in cancer cells. We examined COX-2 localization in several cancer cell lines by confocal microscopy. A majority of COX-2 was colocalized with heat shock protein 60, a mitochondrial protein, in colon cancer (HT-29, HCT-15 and DLD-1), breast cancer (MCF7), hepatocellular cancer (HepG2) and lung cancer cells (A549) with a similar distribution pattern. By contrast, COX-2 was not localized to mitochondria in human foreskin fibroblasts or endothelial cells. Immunoblot analysis of COX-2 in mitochondrial and cytosolic fractions confirmed localization of COX-2 to mitochondria in HT-29 and DLD-1 cells but not in fibroblasts. Calcium-independent phospholipase A2 was colocalized with heat shock protein 60 to mitochondria not only in cancer cells (HT-29 and DLD-1) but also in fibroblasts. HT-29 which expressed more abundant mitochondrial COX-2 than DLD-1 was highly resistant to arachidonic acid and H2O2-induced apoptosis whereas DLD-1 was less resistant and human fibroblasts were highly susceptible. Treatment of HT-29 cells with sulindac or SC-236, a selective COX-2 inhibitor, resulted in loss of resistance to apoptosis. These results suggest that mitochondrial COX-2 in cancer cells confer resistance to apoptosis by reducing the proapoptotic arachidonic acid

  9. Overexpression of CDX2 in gastric cancer cells promotes the development of multidrug resistance.

    Science.gov (United States)

    Yan, Lin-Hai; Wei, Wei-Yuan; Cao, Wen-Long; Zhang, Xiao-Shi; Xie, Yu-Bo; Xiao, Qiang

    2015-01-01

    Modulator of multidrug resistance (MDR) gene is a direct transcriptional target of CDX2. However, we still speculate whether CDX2 affects MDR through other ways. In this study, a cisplatin-resistant (SGC7901/DDP) and a 5-fluoro-2, 4(1h,3h)pyrimidinedione-resistant (BGC823/5-FU) gastric cancer cell line with stable overexpression of CDX2 were established. The influence of overexpression of CDX2 on MDR was assessed by measuring IC50 of SGC7901/DDP and BGC823/5-FU cells to cisplatin, doxorubicin, and 5-fluorouracil, rate of doxorubicin efflux, apoptosis, and cell cycle progression detected by flow cytometry. In addition, we determined the in vivo effects of CDX2-overexpression lentiviral vector (LV-CDX2-GFP) on tumor size, and apoptotic cells in tumor tissues were detected by deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling and hematoxylin and eosin staining. Results showed that LV-CDX2-GFP led to up-regulation of CDX2 mRNA and protein expression. It significantly inhibited the sensitivity of SGC7901/DDP and BGC823/5-FU cells to cisplatin, doxorubicin, and 5-fluorouracil. Flow cytometry confirmed that the percentage of apoptotic cells decreased after CDX2 up-regulation. This notion was further supported by the observation that up-regulation of CDX2 blocked entry into the M-phase of the cell cycle. Furthermore, up-regulation of CDX2 significantly decreased intracellular accumulation of doxorubicin. In molecular studies, quantitative reverse-transcriptase real-time polymerase chain reaction and western blotting revealed that CDX2 up-regulation could suppress expression of Caspase-3, Caspase-9 and PTEN, and increased the expression of MDR1, MRP, mTOR, HIF-1α. PMID:25628941

  10. Anthracycline resistance mediated by reductive metabolism in cancer cells: The role of aldo-keto reductase 1C3

    Energy Technology Data Exchange (ETDEWEB)

    Hofman, Jakub; Malcekova, Beata; Skarka, Adam; Novotna, Eva; Wsol, Vladimir, E-mail: wsol@faf.cuni.cz

    2014-08-01

    Pharmacokinetic drug resistance is a serious obstacle that emerges during cancer chemotherapy. In this study, we investigated the possible role of aldo-keto reductase 1C3 (AKR1C3) in the resistance of cancer cells to anthracyclines. First, the reducing activity of AKR1C3 toward anthracyclines was tested using incubations with a purified recombinant enzyme. Furthermore, the intracellular reduction of daunorubicin and idarubicin was examined by employing the transfection of A549, HeLa, MCF7 and HCT 116 cancer cells with an AKR1C3 encoding vector. To investigate the participation of AKR1C3 in anthracycline resistance, we conducted MTT cytotoxicity assays with these cells, and observed that AKR1C3 significantly contributes to the resistance of cancer cells to daunorubicin and idarubicin, whereas this resistance was reversible by the simultaneous administration of 2′-hydroxyflavanone, a specific AKR1C3 inhibitor. In the final part of our work, we tracked the changes in AKR1C3 expression after anthracycline exposure. Interestingly, a reciprocal correlation between the extent of induction and endogenous levels of AKR1C3 was recorded in particular cell lines. Therefore, we suggest that the induction of AKR1C3 following exposure to daunorubicin and idarubicin, which seems to be dependent on endogenous AKR1C3 expression, eventually might potentiate an intrinsic resistance given by the normal expression of AKR1C3. In conclusion, our data suggest a substantial impact of AKR1C3 on the metabolism of daunorubicin and idarubicin, which affects their pharmacokinetic and pharmacodynamic behavior. In addition, we demonstrate that the reduction of daunorubicin and idarubicin, which is catalyzed by AKR1C3, contributes to the resistance of cancer cells to anthracycline treatment. - Highlights: • Metabolism of anthracyclines by AKR1C3 was studied at enzyme and cellular levels. • Anthracycline resistance mediated by AKR1C3 was demonstrated in cancer cells. • Induction of AKR1C3

  11. Anthracycline resistance mediated by reductive metabolism in cancer cells: The role of aldo-keto reductase 1C3

    International Nuclear Information System (INIS)

    Pharmacokinetic drug resistance is a serious obstacle that emerges during cancer chemotherapy. In this study, we investigated the possible role of aldo-keto reductase 1C3 (AKR1C3) in the resistance of cancer cells to anthracyclines. First, the reducing activity of AKR1C3 toward anthracyclines was tested using incubations with a purified recombinant enzyme. Furthermore, the intracellular reduction of daunorubicin and idarubicin was examined by employing the transfection of A549, HeLa, MCF7 and HCT 116 cancer cells with an AKR1C3 encoding vector. To investigate the participation of AKR1C3 in anthracycline resistance, we conducted MTT cytotoxicity assays with these cells, and observed that AKR1C3 significantly contributes to the resistance of cancer cells to daunorubicin and idarubicin, whereas this resistance was reversible by the simultaneous administration of 2′-hydroxyflavanone, a specific AKR1C3 inhibitor. In the final part of our work, we tracked the changes in AKR1C3 expression after anthracycline exposure. Interestingly, a reciprocal correlation between the extent of induction and endogenous levels of AKR1C3 was recorded in particular cell lines. Therefore, we suggest that the induction of AKR1C3 following exposure to daunorubicin and idarubicin, which seems to be dependent on endogenous AKR1C3 expression, eventually might potentiate an intrinsic resistance given by the normal expression of AKR1C3. In conclusion, our data suggest a substantial impact of AKR1C3 on the metabolism of daunorubicin and idarubicin, which affects their pharmacokinetic and pharmacodynamic behavior. In addition, we demonstrate that the reduction of daunorubicin and idarubicin, which is catalyzed by AKR1C3, contributes to the resistance of cancer cells to anthracycline treatment. - Highlights: • Metabolism of anthracyclines by AKR1C3 was studied at enzyme and cellular levels. • Anthracycline resistance mediated by AKR1C3 was demonstrated in cancer cells. • Induction of AKR1C3

  12. CREB mediates ICAM-3: inducing radio-resistance, cell growth and migration/invasion of the human nonsmall cell lung cancer cell

    International Nuclear Information System (INIS)

    The ICAM family proteins comprises cell surface molecules that are homologous to NCAM and are members of the single passed type 1 immunoglobulin superfamily (IgSF) that are anchored at the cellular membrane. The ICAM family consists of five subfamilies (ICAM-1 to ICAM-5) of heavily glycosylated cell surface receptors with common functional or structural homology. The extracellular domains of ICAM protein have roles in immune response and inflammation through various cell-cell interactions. The cytoplasmic tail residues of ICAM-3 participate in intracellular signaling such as calcium mobilization and tyrosine phosphorylation. Interestingly, the ICAM proteins appear to have a dual role in cancer. ICAM molecules may target and block tumor progression by stimulation of an immune response such as leukocyte activation. Conversely, other investigations have shown that ICAM molecules are involved in cancer malignancy because their increased expressions are associated with a poor diagnosis, lower survival rates and invasion in several cancers including melanoma, breast cancer and leukemia. We have also reported that an increase of ICAM-3 expression in several cancer cells and specimens of cervical cancer patient induce enhanced radio-resistance by the activation of focal adhesion kinase (FAK) and promote cancer cell proliferation by the activation of Akt and p44/42 MAPK. Therefore, these previous reports imply that ICAM-3 has various undefined roles in cancer. In this study, we investigated whether ICAM-3 increase cell migration and invasion through CREB activation and CREB has a role of increase of radioresistance and cell growth

  13. CREB mediates ICAM-3: inducing radio-resistance, cell growth and migration/invasion of the human nonsmall cell lung cancer cell

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jong Kuk; So, Kwang Sup; Bae, In Hwa; Um, Hong Duck [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2009-05-15

    The ICAM family proteins comprises cell surface molecules that are homologous to NCAM and are members of the single passed type 1 immunoglobulin superfamily (IgSF) that are anchored at the cellular membrane. The ICAM family consists of five subfamilies (ICAM-1 to ICAM-5) of heavily glycosylated cell surface receptors with common functional or structural homology. The extracellular domains of ICAM protein have roles in immune response and inflammation through various cell-cell interactions. The cytoplasmic tail residues of ICAM-3 participate in intracellular signaling such as calcium mobilization and tyrosine phosphorylation. Interestingly, the ICAM proteins appear to have a dual role in cancer. ICAM molecules may target and block tumor progression by stimulation of an immune response such as leukocyte activation. Conversely, other investigations have shown that ICAM molecules are involved in cancer malignancy because their increased expressions are associated with a poor diagnosis, lower survival rates and invasion in several cancers including melanoma, breast cancer and leukemia. We have also reported that an increase of ICAM-3 expression in several cancer cells and specimens of cervical cancer patient induce enhanced radio-resistance by the activation of focal adhesion kinase (FAK) and promote cancer cell proliferation by the activation of Akt and p44/42 MAPK. Therefore, these previous reports imply that ICAM-3 has various undefined roles in cancer. In this study, we investigated whether ICAM-3 increase cell migration and invasion through CREB activation and CREB has a role of increase of radioresistance and cell growth.

  14. Quantitative Proteomic Analysis of Ovarian Cancer Cells Identified Mitochondrial Proteins Associated with Paclitaxel Resistance

    OpenAIRE

    Tian, Yuan; Tan, Aik-Choon; Sun, Xiaer; Olson, Matthew T.; Xie, Zhi; Jinawath, Natini; Chan, Daniel W; Shih, Ie-Ming; Zhang, Zhen; Zhang, Hui

    2009-01-01

    Paclitaxel has been widely used as an anti-mitotic agent in chemotherapy for a variety of cancers and adds substantial efficacy as the first-line chemotherapeutic regimen for ovarian cancers. However, the frequent occurrence of paclitaxel resistance limits its function in long-term management. Despite abundant clinical and cellular demonstration of paclitaxel resistant tumors, the molecular mechanisms leading to paclitaxel resistance are poorly understood. Using genomic approaches, we have pr...

  15. Comparison of selected gene expression profiles in sensitive and resistant cancer cells treated with doxorubicin and Selol

    OpenAIRE

    Dudkiewicz-Wilczyńska, Jadwiga; Grabowska, Agnieszka; Książek, Iza; Sitarz, Karolina; Suchocki, Piotr; Anuszewska, Elżbieta

    2014-01-01

    Aim of the study Cellular resistance is strongly correlated with the risk of failure in doxorubicin (DOX) treatment, and the knowledge of the mechanisms of resistance and its possible modulation is still very limited. Material and methods In this study, we assessed the effect of 5% Selol and DOX on the expression of genes that affect cell proliferation in the resistant KB-V1 and sensitive HeLa cell lines, using RT2 ProfilerTM PCR Array matrix “Human Cancer Drug Resistance and Metabolism” (SAB...

  16. Marine sponge-derived sipholane triterpenoids reverse P-glycoprotein (ABCB1)-mediated multidrug resistance in cancer cells

    OpenAIRE

    Abraham, Ioana; Jain, Sandeep; Wu, Chung-pu; Khanfar, Mohammad A.; Kuang, Yehong; Dai, Chun-ling; Shi, Zhi; Chen, Xiang; FU, LIWU; Suresh V Ambudkar; Sayed, Khalid El; Chen, Zhe-Sheng

    2010-01-01

    Previously, we reported sipholenol A, a sipholane triterpenoid from the Red Sea sponge Callyspongia siphonella, as a potent reversal of multidrug resistance (MDR) in cancer cells that overexpressed P-glycoprotein (P-gp). Through extensive screening of several related sipholane triterpenoids that have been isolated from the same sponge, we identified sipholenone E, sipholenol L and siphonellinol D as potent reversals of MDR in cancer cells. These compounds enhanced the cytotoxicity of several ...

  17. Modulation of P-glycoprotein function and multidrug resistance in cancer cells by Thai plant extracts.

    Science.gov (United States)

    Takano, M; Kakizoe, S; Kawami, M; Nagai, J; Patanasethnont, D; Sripanidkulchai, B; Yumoto, R

    2014-11-01

    The effects of ethanol extracts from Thai plants belonging to the families of Annonaceae, Rutaceae, and Zingiberaceae on P-glycoprotein (P-gp) function and multidrug resistance were examined in paclitaxel-resistant HepG2 (PR-HepG2) cells. All the extracts tested, significantly increased the accumulation of [3H]paclitaxel, a P-gp substrate, in the cells. Among nine extracts, Z01 and Z02, extracts from Curcuma comosa and Kaempferia marginata (Zingiberaceae family), respectively, potently increased the accumulation. In addition, Z01 and Z02 increased the accumulation of other P-gp substrates, rhodamine 123 and doxorubicin, in PR-HepG2 cells in a concentration-dependent manner. Increased accumulation of rhodamine 123 and doxorubicin by Z01 and Z02 was also confirmed by confocal laser scanning microscopy. The effect of Z01 and Z02 pretreatment on the expression of MDR1 mRNA was also examined. The expression of MDR1 mRNA was not affected by the treatment of PR-HepG2 cells with these extracts for 48 hours. Cytotoxicity of paclitaxel was examined by XTT and protein assays in the absence and presence of Z02. Z02 potentiated the cytotoxicity of paclitaxel in PR-HepG2 cells. These results suggest that Curcuma comosa and Kaempferia marginata belonging to Zingiberaceae are useful sources to search for new P-gp modulator(s) that can be used to overcome multidrug resistance of cancer cells. PMID:25985578

  18. Screening Metastasis-associated Genes from Anoikis Resistant A549 Lung Cancer Cells by Human Genome Array

    Directory of Open Access Journals (Sweden)

    Xiaoping WANG

    2010-01-01

    Full Text Available Background and objective As a barrier to metastases, cells normally undergo apoptosis after they lose contact with their extra cellular matrix (ECM. This process has been termed “anoikis”. Tumour cells that acquire malignant potential have developed mechanisms to resist anoikis and thereby survive after detachment from their primary site while traveling through the lymphatic and circulatory systems. This “anoikis resistance” is considered the first step to tumor metastases. The aim of this study was to screen metastasis-associated genes from anoikis resistant and adherent growth A549 lung cancer cell by Human Genome Array. Methods Establish anoikis resistant A549 lung cancer cell lines by using poly-hydroxyethyl methacrylate resin processed petri dishes, which causes cell free from adherent. The different expressed gene between anoikis resistant A549 cell and adherent growth A549 cell was tested using human V2.0 whole-genome oligonucleotide microarray, a product of Capitalbio Corporation, Beijing. Screen metastasis-associated genes. Results 745 different expressed genes were screened, including 63 highly metastasis-associated genes. Conclusion The successfully established anoikis resistant A549 cell lines and screened different expressed genes provide us basis for further research on metastasis of lung cancer.

  19. Colorectal cancer cell lines made resistant to SN38-and Oxaliplatin: Roles of altered ion transporter function in resistance?

    DEFF Research Database (Denmark)

    Sandra, Christensen; Jensen, Niels Frank; Stoeckel, Johanne Danmark; Belling, Kirstine C.; Romer, Maria Unni; Gupta, Ramneek; Brunner, Nils; Pedersen, Stine Helene Falsig; Stenvang, Jan

    2013-01-01

    resistance in HCT-116, HT-29 and LoVo cells. Microarray analysis and qPCR validation showed that mRNA expression of glutamate transporters SLC1A1 and SLC1A3 were markedly altered in resistant cells. Remarkably, mRNA levels of SLC1A3 were increased by ~40-and ~2500-fold in SN38-and Oxp-resistant HT29 cells...

  20. Treatment approaches for EGFR-inhibitor-resistant patients with non-small-cell lung cancer.

    Science.gov (United States)

    Tan, Chee-Seng; Gilligan, David; Pacey, Simon

    2015-09-01

    Discovery of activating mutations in EGFR and their use as predictive biomarkers to tailor patient therapy with EGFR tyrosine kinase inhibitors (TKIs) has revolutionised treatment of patients with advanced EGFR-mutant non-small-cell lung cancer (NSCLC). At present, first-line treatment with EGFR TKIs (gefitinib, erlotinib, and afatinib) has been approved for patients harbouring exon 19 deletions or exon 21 (Leu858Arg) substitution EGFR mutations. These agents improve response rates, time to progression, and overall survival. Unfortunately, patients develop resistance, limiting patient benefit and posing a challenge to oncologists. Optimum treatment after progression is not clearly defined. A more detailed understanding of the biology of EGFR-mutant NSCLC and the mechanisms of resistance to targeted therapy mean that an era of treatment approaches based on rationally developed drugs or therapeutic strategies has begun. Combination approaches-eg, dual EGFR blockade-to overcome resistance have been trialled and seem to be promising but are potentially limited by toxicity. Third-generation EGFR-mutant-selective TKIs, such as AZD9291 or rociletininb, which target Thr790Met-mutant tumours, the most common mechanism of EGFR TKI resistance, have entered clinical trials, and exciting, albeit preliminary, efficacy data have been reported. In this Review, we summarise the scientific literature and evidence on therapy options after EGFR TKI treatment for patients with NSCLC, aiming to provide a guide to oncologists, and consider how to maximise therapeutic advances in outcomes in this rapidly advancing area. PMID:26370354

  1. Protection of stromal cell-derived factor 2 by heat shock protein 72 prevents oxaliplatin-induced cell death in oxaliplatin-resistant human gastric cancer cells.

    Science.gov (United States)

    Takahashi, Katsuyuki; Tanaka, Masako; Yashiro, Masakazu; Matsumoto, Masaki; Ohtsuka, Asuka; Nakayama, Keiichi I; Izumi, Yasukatsu; Nagayama, Katsuya; Miura, Katsuyuki; Iwao, Hiroshi; Shiota, Masayuki

    2016-08-01

    Heat shock protein 72 (Hsp72) is a molecular chaperone that assists in the folding of nascent polypeptides and in the refolding of denatured proteins. In many cancers, Hsp72 is constitutively expressed at elevated levels, which can result in enhanced stress tolerance. Similarly, following treatment with anticancer drugs, Hsp72 binds to denatured proteins that may be essential for survival. We therefore hypothesized that Hsp72 client proteins may play a crucial role in drug resistance. Here, we aimed to identify proteins that are critical for oxaliplatin (OXA) resistance by analyzing human gastric cancer cell lines, as well as OXA-resistant cells via a mass spectrometry-based proteomic approach combined with affinity purification using anti-Hsp72 antibodies. Stromal cell-derived factor 2 (SDF-2) was identified as an Hsp72 client protein unique to OCUM-2M/OXA cells. SDF-2 was overexpressed in OXA-resistant cells and SDF-2 silencing promoted the apoptotic effects of OXA. Furthermore, Hsp72 prevented SDF-2 degradation in a chaperone activity-dependent manner. Together, our data demonstrate that Hsp72 protected SDF-2 to avoid OXA-induced cell death. We propose that inhibition of SDF-2 may comprise a novel therapeutic strategy to counteract OXA-resistant cancers. PMID:27157913

  2. Involvement of miR-30c in resistance to doxorubicin by regulating YWHAZ in breast cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Y. [Department of Central Laboratory, The First Affiliated People’s Hospital, Jiangsu University, Zhenjiang, Jiangsu (China); Shen, H. [Department of Oncology, The First Affiliated People’s Hospital, Jiangsu University, Zhenjiang, Jiangsu (China); Cao, Y. [Department of Central Laboratory, The First Affiliated People’s Hospital, Jiangsu University, Zhenjiang, Jiangsu (China); Li, H. [Department of Central Laboratory, The Fourth Affiliated People’s Hospital, Jiangsu University, Zhenjiang, Jiangsu (China); Qin, R. [Department of Oncology, The First Affiliated People’s Hospital, Jiangsu University, Zhenjiang, Jiangsu (China); Chen, Q. [Department of Central Laboratory, The First Affiliated People’s Hospital, Jiangsu University, Zhenjiang, Jiangsu (China); Long, L. [Department of Oncology, The First Affiliated People’s Hospital, Jiangsu University, Zhenjiang, Jiangsu (China); Zhu, X.L. [Department of Central Laboratory, The Fourth Affiliated People’s Hospital, Jiangsu University, Zhenjiang, Jiangsu (China); Xie, C.J. [Department of Central Laboratory, The First Affiliated People’s Hospital, Jiangsu University, Zhenjiang, Jiangsu (China); Xu, W.L. [Department of Central Laboratory, The Fourth Affiliated People’s Hospital, Jiangsu University, Zhenjiang, Jiangsu (China)

    2014-01-10

    MicroRNAs (miRNAs) are small RNA molecules that modulate gene expression implicated in cancer, which play crucial roles in diverse biological processes, such as development, differentiation, apoptosis, and proliferation. The aim of this study was to investigate whether miR-30c mediated the resistance of breast cancer cells to the chemotherapeutic agent doxorubicin (ADR) by targeting tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein zeta (YWHAZ). miR-30c was downregulated in the doxorubicin-resistant human breast cancer cell lines MCF-7/ADR and MDA-MB-231/ADR compared with their parental MCF-7 and MDA-MB-231 cell lines, respectively. Furthermore, we observed that transfection of an miR-30c mimic significantly suppressed the ability of MCF-7/ADR to resist doxorubicin. Moreover, the anti-apoptotic gene YWHAZ was confirmed as a target of miR-30c by luciferase reporter assay, and further studies indicated that the mechanism for miR-30c on the sensitivity of breast cancer cells involved YWHAZ and its downstream p38 mitogen-activated protein kinase (p38MAPK) pathway. Together, our findings provided evidence that miR-30c was one of the important miRNAs in doxorubicin resistance by regulating YWHAZ in the breast cancer cell line MCF-7/ADR.

  3. BIM-EL localization: The key to understanding anoikis resistance in inflammatory breast cancer cells.

    Science.gov (United States)

    Buchheit, Cassandra L; Schafer, Zachary T

    2016-01-01

    Inflammatory breast cancer (IBC) is a highly metastatic and rare type of breast cancer, accounting for 2-6% of newly diagnosed breast cancer cases each year. The highly metastatic nature of IBC cells remains poorly understood. Here we describe our recent data regarding the ability of IBC cells to overcome anoikis. PMID:27308529

  4. BIM-EL localization: The key to understanding anoikis resistance in inflammatory breast cancer cells

    OpenAIRE

    Buchheit, Cassandra L.; Schafer, Zachary T.

    2015-01-01

    Inflammatory breast cancer (IBC) is a highly metastatic and rare type of breast cancer, accounting for 2–6% of newly diagnosed breast cancer cases each year. The highly metastatic nature of IBC cells remains poorly understood. Here we describe our recent data regarding the ability of IBC cells to overcome anoikis.

  5. The hippo pathway effector YAP regulates motility, invasion, and castration-resistant growth of prostate cancer cells.

    Science.gov (United States)

    Zhang, Lin; Yang, Shuping; Chen, Xingcheng; Stauffer, Seth; Yu, Fang; Lele, Subodh M; Fu, Kai; Datta, Kaustubh; Palermo, Nicholas; Chen, Yuanhong; Dong, Jixin

    2015-04-01

    Yes-associated protein (YAP) is an effector of the Hippo tumor suppressor pathway. The functional significance of YAP in prostate cancer has remained elusive. In this study, we first show that enhanced expression of YAP is able to transform immortalized prostate epithelial cells and promote migration and invasion in both immortalized and cancerous prostate cells. We found that YAP mRNA was upregulated in androgen-insensitive prostate cancer cells (LNCaP-C81 and LNCaP-C4-2 cells) compared to the level in androgen-sensitive LNCaP cells. Importantly, ectopic expression of YAP activated androgen receptor signaling and was sufficient to promote LNCaP cells from an androgen-sensitive state to an androgen-insensitive state in vitro, and YAP conferred castration resistance in vivo. Accordingly, YAP knockdown greatly reduced the rates of migration and invasion of LNCaP-C4-2 cells and under androgen deprivation conditions largely blocked cell division in LNCaP-C4-2 cells. Mechanistically, we found that extracellular signal-regulated kinase-ribosomal s6 kinase signaling was downstream of YAP for cell survival, migration, and invasion in androgen-insensitive cells. Finally, immunohistochemistry showed significant upregulation and hyperactivation of YAP in castration-resistant prostate tumors compared to their levels in hormone-responsive prostate tumors. Together, our results identify YAP to be a novel regulator in prostate cancer cell motility, invasion, and castration-resistant growth and as a potential therapeutic target for metastatic castration-resistant prostate cancer (CRPC). PMID:25645929

  6. Relationship between Methylation Status of Multi-drug Resistance Protein(MRP) and Multi-drug Resistance in Lung Cancer Cell Lines

    Institute of Scientific and Technical Information of China (English)

    LIU Rui-jun; ZHONG Hong

    2007-01-01

    Objective: To study the relationship between the methylation status of multi-drug resistance protein (MRP) gene and the expression of its mRNA and protein in lung cancer cell lines. Methods: Human embryo lung cell line WI-38, lung adenocarcinoma cell line SPCA-1 and its drug-resistant cells induced by different concentrations of doxorubicin were treated with restriction endonuclease Eco47Ⅲ. The methylation status of MRP was examined by PCR, and the expressions of its mRNA and protein were evaluated by in situ hybridization and immunohistochemistry. Results: MRP gene promoter region of WI-38 cells was in hypermethylation status, but the promoter region of MRP in SPCA-1 cells and their resistant derivatives induced by different concentrations of doxorubicin were in hypomethylation status. There were significant differences in the expression of MRP mRNA among WI-38 cell line, SPCA-1 cells and their drug-resistant derivatives induced by different concentration of doxorubicin. Consistently, MRP immunostaining presented similar significant differences. Conclusion: The promoter region of MRP in SPCA-1 lung adenocarcinoma cells was in hypomethylation status. The hypomethylation status of 5' regulatory region of MRP promoter is an important structural basis that can increase the activity of transcription and results in the development of drug resistance in lung cancer.

  7. Canine Mammary Cancer Stem Cells are Radio- and Chemo-Resistant and Exhibit an Epithelial-Mesenchymal Transition Phenotype

    Energy Technology Data Exchange (ETDEWEB)

    Pang, Lisa Y., E-mail: lisa.pang@ed.ac.uk; Cervantes-Arias, Alejandro; Else, Rod W.; Argyle, David J. [Royal (Dick) School of Veterinary Studies and Roslin Institute, The University of Edinburgh, Easter Bush, Midlothian, EH25 9RG (United Kingdom)

    2011-03-30

    Canine mammary carcinoma is the most common cancer among female dogs and is often fatal due to the development of distant metastases. In humans, solid tumors are made up of heterogeneous cell populations, which perform different roles in the tumor economy. A small subset of tumor cells can hold or acquire stem cell characteristics, enabling them to drive tumor growth, recurrence and metastasis. In veterinary medicine, the molecular drivers of canine mammary carcinoma are as yet undefined. Here we report that putative cancer stem cells (CSCs) can be isolated form a canine mammary carcinoma cell line, REM134. We show that these cells have an increased ability to form tumorspheres, a characteristic of stem cells, and that they express embryonic stem cell markers associated with pluripotency. Moreover, canine CSCs are relatively resistant to the cytotoxic effects of common chemotherapeutic drugs and ionizing radiation, indicating that failure of clinical therapy to eradicate canine mammary cancer may be due to the survival of CSCs. The epithelial to mesenchymal transition (EMT) has been associated with cancer invasion, metastasis, and the acquisition of stem cell characteristics. Our results show that canine CSCs predominantly express mesenchymal markers and are more invasive than parental cells, indicating that these cells have a mesenchymal phenotype. Furthermore, we show that canine mammary cancer cells can be induced to undergo EMT by TGFβ and that these cells have an increased ability to form tumorspheres. Our findings indicate that EMT induction can enrich for cells with CSC properties, and provide further insight into canine CSC biology.

  8. Canine Mammary Cancer Stem Cells are Radio- and Chemo-Resistant and Exhibit an Epithelial-Mesenchymal Transition Phenotype

    International Nuclear Information System (INIS)

    Canine mammary carcinoma is the most common cancer among female dogs and is often fatal due to the development of distant metastases. In humans, solid tumors are made up of heterogeneous cell populations, which perform different roles in the tumor economy. A small subset of tumor cells can hold or acquire stem cell characteristics, enabling them to drive tumor growth, recurrence and metastasis. In veterinary medicine, the molecular drivers of canine mammary carcinoma are as yet undefined. Here we report that putative cancer stem cells (CSCs) can be isolated form a canine mammary carcinoma cell line, REM134. We show that these cells have an increased ability to form tumorspheres, a characteristic of stem cells, and that they express embryonic stem cell markers associated with pluripotency. Moreover, canine CSCs are relatively resistant to the cytotoxic effects of common chemotherapeutic drugs and ionizing radiation, indicating that failure of clinical therapy to eradicate canine mammary cancer may be due to the survival of CSCs. The epithelial to mesenchymal transition (EMT) has been associated with cancer invasion, metastasis, and the acquisition of stem cell characteristics. Our results show that canine CSCs predominantly express mesenchymal markers and are more invasive than parental cells, indicating that these cells have a mesenchymal phenotype. Furthermore, we show that canine mammary cancer cells can be induced to undergo EMT by TGFβ and that these cells have an increased ability to form tumorspheres. Our findings indicate that EMT induction can enrich for cells with CSC properties, and provide further insight into canine CSC biology

  9. Cancer stem cell and its relevance to tumors resistance to radiotherapy

    International Nuclear Information System (INIS)

    The gradually accumulated information and knowledge regarding cancer stem cell or stem-like cancer cell greatly potentiated the research progression of radiation oncology and biology. In recent years, a series studies have uncovered that the cancer stem cell and cancer quiescent cell could be the major cells origin attributed to the radioresistance and recurrence of tumors in the course of radiotherapy. A rapid research progression has already been achieved respecting the radiosensitivity and related mechanisms of these two subsets of cancer cells, and which provides an idea strategy for development of the measures targeting tumor radioresistance. This paper reviewed and discussed the cellular basis and molecular mechanism of the tumor radioresistance from the aspects of cancer cells subsets and the radiobiological characteristics. (authors)

  10. Targeting head and neck cancer stem cells to overcome resistance to photon and carbon ion radiation.

    Science.gov (United States)

    Bertrand, Gérald; Maalouf, Mira; Boivin, Antony; Battiston-Montagne, Priscillia; Beuve, Michael; Levy, Antonin; Jalade, Patrice; Fournier, Claudia; Ardail, Dominique; Magné, Nicolas; Alphonse, Gersende; Rodriguez-Lafrasse, Claire

    2014-02-01

    Although promising new radiation therapy techniques such as hadrontherapy are currently being evaluated in the treatment of head and neck malignancies, local control of head and neck squamous cell carcinoma (HNSCC) remains low. Here, we investigated the involvement of cancer stem-like cells (CSCs) in a radioresistant HNSCC cell line (SQ20B). Stem-like cells SQ20B/SidePopulation(SP)/CD44(+)/ALDH(high) were more resistant to both photon and carbon ion irradiation compared with non-CSCs. This was confirmed by a BrdU labeling experiment, which suggests that CSCs were able to proliferate and to induce tumorigenicity after irradiation. SQ20B/SP/CD44(+)/ALDH(high) were capable of an extended G2/M arrest phase in response to photon or carbon ion irradiation compared with non-CSCs. Moreover, our data strongly suggest that resistance of CSCs may result from an imbalance between exacerbated self-renewal and proliferative capacities and the decrease in apoptotic cell death triggering. In order to modulate these processes, two targeted pharmacological strategies were tested. Firstly, UCN-01, a checkpoint kinase (Chk1) inhibitor, induced the relapse of G2/M arrest and radiosensitization of SQ20B-CSCs. Secondly, all-trans retinoic acid (ATRA) resulted in an inhibition of ALDH activity, and induction of the differentiation and radiosensitization of SQ20B/SP/CD44(+)/ALDH(high) cells. The combination of ATRA and UCN-01 treatments with irradiation drastically decreased the surviving fraction at 2Gy of SQ20B-CSCs from 0.85 to 0.38 after photon irradiation, and from 0.45 to 0.21 in response to carbon ions. Taken together, our results suggest that the combination of UCN-01 and ATRA represent a promising pharmacological-targeted strategy that significantly sensitizes CSCs to photon or carbon ion radiation. PMID:23955575

  11. Resistance of Cancer Cells to Targeted Therapies Through the Activation of Compensating Signaling Loops.

    Science.gov (United States)

    von Manstein, Viktoria; Yang, Chul Min; Richter, Diane; Delis, Natalia; Vafaizadeh, Vida; Groner, Bernd

    2013-12-01

    The emergence of low molecular weight kinase inhibitors as "targeted" drugs has led to remarkable advances in the treatment of cancer patients. The clinical benefits of these tumor therapies, however, vary widely in patient populations and with duration of treatment. Intrinsic and acquired resistance against such drugs limits their efficacy. In addition to the well studied mechanisms of resistance based upon drug transport and metabolism, genetic alterations in drug target structures and the activation of compensatory cell signaling have received recent attention. Adaptive responses can be triggered which counteract the initial dependence of tumor cells upon a particular signaling molecule and allow only a transient inhibition of tumor cell growth. These compensating signaling mechanisms are often based upon the relief of repression of regulatory feedback loops. They might involve cell autonomous, intracellular events or they can be mediated via the secretion of growth factor receptor ligands into the tumor microenvironment and signal induction in an auto- or paracrine fashion. The transcription factors Stat3 and Stat5 mediate the biological functions of cytokines, interleukins and growth factors and can be considered as endpoints of multiple signaling pathways. In normal cells this activation is transient and the Stat molecules return to their non-phosphorylated state within a short time period. In tumor cells the balance between activating and de-activating signals is disturbed resulting in the persistent activation of Stat3 or Stat5. The constant activation of Stat3 induces the expression of target genes, which cause the proliferation and survival of cancer cells, as well as their migration and invasive behavior. Activating components of the Jak-Stat pathway have been recognized as potentially valuable drug targets and important principles of compensatory signaling circuit induction during targeted drug treatment have been discovered in the context of kinase

  12. Differentially expressed proteins in human MCF-7 breast cancer cells sensitive and resistant to paclitaxel

    Czech Academy of Sciences Publication Activity Database

    Pavlíková, N.; Bartoňová, I.; Balušíková, K.; Kopperová, D.; Halada, Petr; Kovář, J.

    2015-01-01

    Roč. 333, č. 1 (2015), s. 1-10. ISSN 0014-4827 Institutional support: RVO:61388971 Keywords : Breast cancer * Taxane resistance * 2-D electrophoresis Subject RIV: CE - Biochemistry Impact factor: 3.246, year: 2014

  13. AZD9291 in epidermal growth factor receptor inhibitor—resistant non-small-cell lung cancer

    Science.gov (United States)

    2016-01-01

    Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in advanced EGFR mutant non-small cell lung cancer have an objective response rate (ORR) of approximately 60–70% and a median progression free-survival (PFS) of approximately 10-13 months. Studies of tumor biopsies performed after progression on EGFR TKI revealed that 50-60% of EGFR mutant NSCLC developed an EGFR exon 20 T790M mutation as a mechanism of acquired resistance. AZD9291 is a third generation irreversible EGFR TKI with activity against the activating EGFR mutation, the T790M acquired resistance mutation, and relative sparing of the wild-type EGFR. AZD9291 was investigated in a phase I trial with expansion cohorts in patients with disease progression after EGFR TKI. Patients with and without detectable T790M mutations were enrolled in the trial. The ORR in patients with centrally confirmed and without detectable T790M mutations was 61% (95% CI, 52–70%) and 21% (95% CI, 12–34%), respectively. The PFS observed in patients with centrally confirmed and without detectable T790M mutations was 9.6 months (95% CI, 8.3 to not reached) and 2.8 months (95% CI, 2.1–4.3 months), respectively. At the dose for further investigation, 80 mg daily, the rate of all grade 3-5 drug related adverse events was 11%, and the rates of grade 3 diarrhea and rash were 1% and 0%, respectively. The identification of the T790M resistance mutation and the subsequent development of an agent against the mechanism of resistance provide a template for future drug development for acquired resistance to targeted therapy. PMID:26958499

  14. AZD9291 in epidermal growth factor receptor inhibitor-resistant non-small-cell lung cancer.

    Science.gov (United States)

    Stinchcombe, Thomas E

    2016-02-01

    Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in advanced EGFR mutant non-small cell lung cancer have an objective response rate (ORR) of approximately 60-70% and a median progression free-survival (PFS) of approximately 10-13 months. Studies of tumor biopsies performed after progression on EGFR TKI revealed that 50-60% of EGFR mutant NSCLC developed an EGFR exon 20 T790M mutation as a mechanism of acquired resistance. AZD9291 is a third generation irreversible EGFR TKI with activity against the activating EGFR mutation, the T790M acquired resistance mutation, and relative sparing of the wild-type EGFR. AZD9291 was investigated in a phase I trial with expansion cohorts in patients with disease progression after EGFR TKI. Patients with and without detectable T790M mutations were enrolled in the trial. The ORR in patients with centrally confirmed and without detectable T790M mutations was 61% (95% CI, 52-70%) and 21% (95% CI, 12-34%), respectively. The PFS observed in patients with centrally confirmed and without detectable T790M mutations was 9.6 months (95% CI, 8.3 to not reached) and 2.8 months (95% CI, 2.1-4.3 months), respectively. At the dose for further investigation, 80 mg daily, the rate of all grade 3-5 drug related adverse events was 11%, and the rates of grade 3 diarrhea and rash were 1% and 0%, respectively. The identification of the T790M resistance mutation and the subsequent development of an agent against the mechanism of resistance provide a template for future drug development for acquired resistance to targeted therapy. PMID:26958499

  15. Exosomes from drug-resistant breast cancer cells transmit chemoresistance by a horizontal transfer of microRNAs.

    Directory of Open Access Journals (Sweden)

    Wei-xian Chen

    Full Text Available Adriamycin and docetaxel are two agents commonly used in treatment of breast cancer, but their efficacy is often limited by the emergence of chemoresistance. Recent studies indicate that exosomes act as vehicles for exchange of genetic cargo between heterogeneous populations of tumor cells, engendering a transmitted drug resistance for cancer development and progression. However, the specific contribution of breast cancer-derived exosomes is poorly understood. Here we reinforced other's report that human breast cancer cell line MCF-7/S could acquire increased survival potential from its resistant variants MCF-7/Adr and MCF-7/Doc. Additionally, exosomes of the latter, A/exo and D/exo, significantly modulated the cell cycle distribution and drug-induced apoptosis with respect to S/exo. Exosomes pre-treated with RNase were unable to regulate cell cycle and apoptosis resistance, suggesting an RNA-dependent manner. Microarray and polymerase chain reaction for the miRNA expression profiles of A/exo, D/exo, and S/exo demonstrated that they loaded selective miRNA patterns. Following A/exo and D/exo transfer to recipient MCF-7/S, the same miRNAs were significantly increased in acquired cells. Target gene prediction and pathway analysis showed the involvement of miR-100, miR-222, and miR-30a in pathways implicated in cancer pathogenesis, membrane vesiculation and therapy failure. Furthermore, D/exo co-culture assays and miRNA mimics transfection experiments indicated that miR-222-rich D/exo could alter target gene expression in MCF-7/S. Our results suggest that drug-resistant breast cancer cells may spread resistance capacity to sensitive ones by releasing exosomes and that such effects could be partly attributed to the intercellular transfer of specific miRNAs.

  16. STAT3-dependent TXNDC17 expression mediates Taxol resistance through inducing autophagy in human colorectal cancer cells.

    Science.gov (United States)

    Zhang, Zhongde; Wang, Aihua; Li, Hui; Zhi, Hui; Lu, Feng

    2016-06-10

    Taxol (paclitaxel) is one of the taxane class of anticancer drugs as a first-line chemotherapeutic agent against many cancers including colorectal cancer, breast cancer, non-small cell lung cancer, ovarian cancer and so on. It is verified to induce cytotoxicity in a concentration and time-dependent manner. Numerous novel formulations of Taxol have been remanufactured for better therapeutic effect. Though Taxol works as a common anticancer drug for a long time in clinical practice, drug resistance is a major limitation of its long-term administration. In-depth research on drug resistance is still in progress and researchers have made some achievements, however, the mechanism or key molecule related to Taxol resistance in colorectal cancer still remains to be explored. In the present study, we observed that the high expression of TXNDC17 (thioredoxin domain containing 17) was associated with Taxol resistance in colorectal cancer cells. And TXNDC17 mediated Taxol resistance was related with increased basal autophagy level. Taxol exposure induced high levels of phospho-STAT3 (Tyr 705) and TXNDC17; and increase of basal autophagy in colorectal cancer cells. TXNDC17 overexpression cells obtained Taxol resistance and a high level of autophagy, and it is not surprising that stable downregulation of TXNDC17 accordingly reversed these phenomena. Interestingly, STAT3 could similarly work as TXNDC17 in spite of slighter effect compared to TXNDC17. And it has been proved that phospho-STAT3 (Tyr 705) possesses transcriptional regulation activity through forming dimmers. Many research revealed that transcription factor STAT3 affected more than 1000 gene products, and TXNDC17 is predicted to be a target gene of STAT3 at UCSC database. For the first time, we found STAT3 could bind promoter region of TXNDC17 (-623bp to -58bp relative to the transcription start site (TSS)) for regulating its expression. These results suggest the possibility that TXNDC17 could play an important role

  17. Chemotherapeutic Activities of Carthami Flos and Its Reversal Effect on Multidrug Resistance in Cancer Cells

    OpenAIRE

    Wu, Jimmy Yiu-Cheong; Yu, Zhi-Ling; Fong, Wang-Fun; Shi, Yi-Qian

    2013-01-01

    Multidrug-resistance (MDR) represents a major cause of failure in cancer chemotherapy. The need for a reduction in MDR by natural-product-based drugs of low toxicity led to the current investigation of applying medicinal herbs in future cancer adjuvant therapy. Carthami Flos (CF), the dried flower of safflower (Carthamus tinctorius L.), is one of the most popular traditional Chinese medicinal herbs used to alleviate pain, increase circulation, and reduce blood-stasis syndrome. The drug resist...

  18. Reversal effects of nomegestrol acetate on multidrug resistance in adriamycin-resistant MCF7 breast cancer cell line

    International Nuclear Information System (INIS)

    Chemotherapy is important in the systematic treatment of breast cancer. To enhance the response of tumours to chemotherapy, attention has been focused on agents to reverse multidrug resistance (MDR) and on the sensitivity of tumour cells to chemical drugs. Hundreds of reversal drugs have been found in vitro, but their clinical application has been limited because of their toxicity. The reversal activity of progestogen compounds has been demonstrated. However, classical agents such as progesterone and megestrol (MG) also have high toxicity. Nomegestrol (NOM) belongs to a new derivation of progestogens and shows very low toxicity. We studied the reversal activity of NOM and compared it with that of verapamil (VRP), droloxifene (DRO), tamoxifen (TAM) and MG, and investigated the reversal mechanism, i.e. effects on the expression of the MDR1, glutathione S-transferase Pi (GSTπ), MDR-related protein (MRP) and topoisomerase IIα (TopoIIα) genes, as well as the intracellular drug concentration and the cell cycle. The aim of the study was to examine the reversal effects of NOM on MDR in MCF7/ADR, an MCF7 breast cancer cell line resistant to adriamycin (ADR), and its mechanism of action. MCF7/ADR cells and MCF7/WT, an MCF7 breast cancer cell line sensitive to ADR, were treated with NOM as the acetate ester. With an assay based on a tetrazolium dye [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide; MTT], the effects of various concentrations of NOM on MDR in MCF7/ADR cells were studied. Before and after the treatment with 5 μM NOM, the expression of the MDR-related genes MDR1, GSTπ, TopoIIα and MRP were assayed with a reverse transcriptase polymerase chain reaction (RT-PCR) immunocytochemistry assay. By using flow cytometry (FCM), we observed the intracellular ADR concentration and the effects of combined treatment with NOM and ADR on the cell cycle. Results collected were analysed with Student's t test. NOM significantly reversed MDR in MCF7/ADR

  19. Sensitization of multidrug-resistant human cancer cells to Hsp90 inhibitors by down-regulation of SIRT1

    Science.gov (United States)

    Kim, Hak-Bong; Lee, Su-Hoon; Um, Jee-Hyun; Oh, Won Keun; Kim, Dong-Wan; Kang, Chi-Dug; Kim, Sun-Hee

    2015-01-01

    The effectiveness of Hsp90 inhibitors as anticancer agents was limited in multidrug-resistant (MDR) human cancer cells due to induction of heat shock proteins (Hsps) such as Hsp70/Hsp27 and P-glycoprotein (P-gp)-mediated efflux. In the present study, we showed that resistance to Hsp90 inhibitors of MDR human cancer cells could be overcome with SIRT1 inhibition. SIRT1 knock-down or SIRT1 inhibitors (amurensin G and EX527) effectively suppressed the resistance to Hsp90 inhibitors (17-AAG and AUY922) in several MDR variants of human lymphoblastic leukemia and human breast cancer cell lines. SIRT1 inhibition down-regulated the expression of heat shock factor 1 (HSF1) and subsequently Hsps and facilitated Hsp90 multichaperone complex disruption via hyperacetylation of Hsp90/Hsp70. These findings were followed by acceleration of ubiquitin ligase CHIP-mediated mutant p53 (mut p53) degradation and subsequent down-regulation of P-gp in 17-AAG-treated MDR cancer cells expressing P-gp and mut p53 after inhibition of SIRT1. Therefore, combined treatment with Hsp90 inhibitor and SIRT1 inhibitor could be a more effective therapeutic approach for Hsp90 inhibitor-resistant MDR cells via down-regulation of HSF1/Hsps, mut p53 and P-gp. PMID:26416354

  20. Lung Cancer Stem Cells

    OpenAIRE

    Pine, Sharon R.; Blair Marshall; Lyuba Varticovski

    2008-01-01

    Lung cancer remains a major cause of cancer-related lethality because of high incidence and recurrence in spite of significant advances in staging and therapies. Recent data indicates that stem cells situated throughout the airways may initiate cancer formation. These putative stem cells maintain protumorigenic characteristics including high proliferative capacity, multipotent differentiation, drug resistance and long lifespan relative to other cells. Stem cell signaling and differentiation p...

  1. ERK phosphorylation is predictive of resistance to IGF-1R inhibition in small cell lung cancer.

    Science.gov (United States)

    Zinn, Rebekah L; Gardner, Eric E; Marchionni, Luigi; Murphy, Sara C; Dobromilskaya, Irina; Hann, Christine L; Rudin, Charles M

    2013-06-01

    New therapies are critically needed to improve the outcome for patients with small cell lung cancer (SCLC). Insulin-like growth factor 1 receptor (IGF-1R) inhibition is a potential treatment strategy for SCLC: the IGF-1R pathway is commonly upregulated in SCLC and has been associated with inhibition of apoptosis and stimulation of proliferation through downstream signaling pathways, including phosphatidylinositol-3-kinase-Akt and mitogen-activated protein kinase. To evaluate potential determinants of response to IGF-1R inhibition, we assessed the relative sensitivity of 19 SCLC cell lines to OSI-906, a small molecule inhibitor of IGF-1R, and the closely related insulin receptor. Approximately one third of these cell lines were sensitive to OSI-906, with an IC50 OSI-906. Interestingly, OSI-906 sensitive lines expressed significantly lower levels of baseline phospho-ERK relative to resistant lines (P = 0.006). OSI-906 treatment resulted in dose-dependent inhibition of phospho-IGF-1R and phospho-Akt in both sensitive and resistant cell lines, but induced apoptosis and cell-cycle arrest only in sensitive lines. We tested the in vivo efficacy of OSI-906 using an NCI-H187 xenograft model and two SCLC patient xenografts in mice. OSI-906 treatment resulted in 50% tumor growth inhibition in NCI-H187 and 30% inhibition in the primary patient xenograft models compared with mock-treated animals. Taken together our data support IGF-1R inhibition as a viable treatment strategy for a defined subset of SCLC and suggest that low pretreatment levels of phospho-ERK may be indicative of sensitivity to this therapeutic approach. PMID:23515613

  2. Preliminary research on dendritic cells loaded with resistant breast cancer antigens in breast cancer-bearing nude mice

    Institute of Scientific and Technical Information of China (English)

    Wei Zhuang; Limin Lun

    2015-01-01

    Objective The aim of the study was to investigate the inhibitory ef ects of dendritic cel s (DCs) loaded with resistant breast cancer antigens on breast cancer in nude mice. Methods A single-cel suspension was prepared from a primary breast cancer and chemotherapeutic drugs were screened using the ATP-PCA susceptibility testing system. Cancer cel s were treated with 1/10 × IC50, 1/5 × IC50, 1/2 × IC50, 1 × IC50, and 2 × IC50 medium until their growth became steady in the 2 × IC50 medium. Peripheral blood mononuclear cel s (PBMCs) were obtained from the peripheral blood of patients with leukapheresis. The obtained adherent cel s were induced by granulocyte-macrophage colony-stimu-lating factor (GM-CSF) and interleukin-4 (IL-4) to generate DCs, which carried resistant strain cel lysis compounds or non-treated cancer cel lysis compounds. The former mature DCs carried resistant breast tumor antigens. A breast tumor-bearing nude mouse model was established with these resistant strains and the mice were randomly divided in three groups. The mice in the treatment group were injected with DCs loaded with resistant breast cancer antigens. The control group consisted of mice injected with DCs loaded with primary tumor cel antigens and the blank group consisted of mice injected with the same volume of normal saline. Changes in the cancers were observed. Results After treatment with the ef ector cel s, the cancer volume and weight were significantly dif erent to those before treatment in every group of mice (P Conclusion DCs loaded with resistant breast cancer antigens demonstrated a significant inhibition ef ect on the cancers of breast tumor-bearing nude mice.

  3. A Cell-Targeted, Size-Photocontrollable, Nuclear-Uptake Nanodrug Delivery System for Drug-Resistant Cancer Therapy

    OpenAIRE

    Qiu, Liping; Chen, Tao; Öçsoy, Ismail; Yasun, Emir; Wu, Cuichen; Zhu, Guizhi; You, Mingxu; Han, Da; Jiang, Jianhui; Yu, Ruqin; Tan, Weihong

    2014-01-01

    The development of multidrug resistance (MDR) has become an increasingly serious problem in cancer therapy. The cell-membrane overexpression of P-glycoprotein (P-gp), which can actively efflux various anticancer drugs from the cell, is a major mechanism of MDR. Nuclear-uptake nanodrug delivery systems, which enable intranuclear release of anticancer drugs, are expected to address this challenge by bypassing P-gp. However, before entering the nucleus, the nanocarrier must pass through the cell...

  4. ZNF93 increases resistance to ET-743 (Trabectedin; Yondelis and PM00104 (Zalypsis in human cancer cell lines.

    Directory of Open Access Journals (Sweden)

    Zhenfeng Duan

    Full Text Available BACKGROUND: ET-743 (trabectedin, Yondelis and PM00104 (Zalypsis are marine derived compounds that have antitumor activity. ET-743 and PM00104 exposure over sustained periods of treatment will result in the development of drug resistance, but the mechanisms which lead to resistance are not yet understood. METHODOLOGY/PRINCIPAL FINDINGS: Human chondrosarcoma cell lines resistant to ET-743 (CS-1/ER or PM00104 (CS-1/PR were established in this study. The CS-1/ER and CS-1/PR exhibited cross resistance to cisplatin and methotrexate but not to doxorubicin. Human Affymetrix Gene Chip arrays were used to examine relative gene expression in these cell lines. We found that a large number of genes have altered expression levels in CS-1/ER and CS-1/PR when compared to the parental cell line. 595 CS-1/ER and 498 CS-1/PR genes were identified as overexpressing; 856 CS-1/ER and 874 CS-1/PR transcripts were identified as underexpressing. Three zinc finger protein (ZNF genes were on the top 10 overexpressed genes list. These genes have not been previously associated with drug resistance in tumor cells. Differential expressions of ZNF93 and ZNF43 genes were confirmed in both CS-1/ER and CS-1/PR resistant cell lines by real-time RT-PCR. ZNF93 was overexpressed in two ET-743 resistant Ewing sarcoma cell lines as well as in a cisplatin resistant ovarian cancer cell line, but was not overexpressed in paclitaxel resistant cell lines. ZNF93 knockdown by siRNA in CS-1/ER and CS-1/PR caused increased sensitivity for ET-743, PM00104, and cisplatin. Furthermore, ZNF93 transfected CS-1 cells are relatively resistant to ET-743, PM00104 and cisplatin. CONCLUSIONS/SIGNIFICANCE: This study suggests that zinc finger proteins, and ZNF93 in particular, are involved in resistance to ET-743 and PM00104.

  5. Antitumor activity of sorafenib in human cancer cell lines with acquired resistance to EGFR and VEGFR tyrosine kinase inhibitors.

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    Floriana Morgillo

    Full Text Available Treatment of non small cell lung cancer (NSCLC and colorectal cancer (CRC have substantially changed in the last years with the introduction of epidermal growth factor receptor (EGFR inhibitors in the clinical practice. The understanding of mechanisms which regulate cells sensitivity to these drugs is necessary for their optimal use.An in vitro model of acquired resistance to two tyrosine kinase inhibitors (TKI targeting the EGFR, erlotinib and gefitinib, and to a TKI targeting EGFR and VEGFR, vandetanib, was developed by continuously treating the human NSCLC cell line CALU-3 and the human CRC cell line HCT116 with escalating doses of each drug. MTT, western blot analysis, migration, invasion and anchorage-independent colony forming assays were conducted in vitro and experiments with established xenografts in athymic nude mice were performed in vivo in sensitive, wild type (WT and TKI-resistant CALU-3 and HCT116 cell lines.As compared to WT CALU-3 and HCT116 human cancer cells, TKI-resistant cell lines showed a significant increase in the levels of activated, phosphorylated AKT, MAPK, and of survivin. Considering the role of RAS and RAF as downstream signals of both the EGFR and VEGFR pathways, we treated resistant cells with sorafenib, an inhibitor of C-RAF, B-RAF, c-KIT, FLT-3, RET, VEGFR-2, VEGFR-3, and PDGFR-β. Sorafenib reduced the activation of MEK and MAPK and caused an inhibition of cell proliferation, invasion, migration, anchorage-independent growth in vitro and of tumor growth in vivo of all TKI-resistant CALU-3 and HCT116 cell lines.These data suggest that resistance to EGFR inhibitors is predominantly driven by the RAS/RAF/MAPK pathway and can be overcame by treatment with sorafenib.

  6. Identification of microRNAs and mRNAs associated with multidrug resistance of human laryngeal cancer Hep-2 cells

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    Yin, Wanzhong; Wang, Ping; Wang, Xin [Department of Otorhinolaryngology, Head and Neck Surgery, The First Clinical Hospital, Norman Bethune College of Medicine, Jilin University, Changchun (China); Song, Wenzhi [Department of Stomatology, China-Japan Friendship Hospital, Jilin University, Changchun (China); Cui, Xiangyan; Yu, Hong; Zhu, Wei [Department of Otorhinolaryngology, Head and Neck Surgery, The First Clinical Hospital, Norman Bethune College of Medicine, Jilin University, Changchun (China)

    2013-06-12

    Multidrug resistance (MDR) poses a serious impediment to the success of chemotherapy for laryngeal cancer. To identify microRNAs and mRNAs associated with MDR of human laryngeal cancer Hep-2 cells, we developed a multidrug-resistant human laryngeal cancer subline, designated Hep-2/v, by exposing Hep-2 cells to stepwise increasing concentrations of vincristine (0.02-0.96'µM). Microarray assays were performed to compare the microRNA and mRNA expression profiles of Hep-2 and Hep-2/v cells. Compared to Hep-2 cells, Hep-2/v cells were more resistant to chemotherapy drugs (∼45-fold more resistant to vincristine, 5.1-fold more resistant to cisplatin, and 5.6-fold more resistant to 5-fluorouracil) and had a longer doubling time (42.33±1.76 vs 28.75±1.12'h, P<0.05), higher percentage of cells in G0/G1 phase (80.98±0.52 vs 69.14±0.89, P<0.05), increased efflux of rhodamine 123 (95.97±0.56 vs 12.40±0.44%, P<0.01), and up-regulated MDR1 expression. A total of 7 microRNAs and 605 mRNAs were differentially expressed between the two cell types. Of the differentially expressed mRNAs identified, regulator of G-protein signaling 10, high-temperature requirement protein A1, and nuclear protein 1 were found to be the putative targets of the differentially expressed microRNAs identified. These findings may open a new avenue for clarifying the mechanisms responsible for MDR in laryngeal cancer.

  7. Identification of microRNAs and mRNAs associated with multidrug resistance of human laryngeal cancer Hep-2 cells

    International Nuclear Information System (INIS)

    Multidrug resistance (MDR) poses a serious impediment to the success of chemotherapy for laryngeal cancer. To identify microRNAs and mRNAs associated with MDR of human laryngeal cancer Hep-2 cells, we developed a multidrug-resistant human laryngeal cancer subline, designated Hep-2/v, by exposing Hep-2 cells to stepwise increasing concentrations of vincristine (0.02-0.96'µM). Microarray assays were performed to compare the microRNA and mRNA expression profiles of Hep-2 and Hep-2/v cells. Compared to Hep-2 cells, Hep-2/v cells were more resistant to chemotherapy drugs (∼45-fold more resistant to vincristine, 5.1-fold more resistant to cisplatin, and 5.6-fold more resistant to 5-fluorouracil) and had a longer doubling time (42.33±1.76 vs 28.75±1.12'h, P<0.05), higher percentage of cells in G0/G1 phase (80.98±0.52 vs 69.14±0.89, P<0.05), increased efflux of rhodamine 123 (95.97±0.56 vs 12.40±0.44%, P<0.01), and up-regulated MDR1 expression. A total of 7 microRNAs and 605 mRNAs were differentially expressed between the two cell types. Of the differentially expressed mRNAs identified, regulator of G-protein signaling 10, high-temperature requirement protein A1, and nuclear protein 1 were found to be the putative targets of the differentially expressed microRNAs identified. These findings may open a new avenue for clarifying the mechanisms responsible for MDR in laryngeal cancer

  8. Lung Cancer Stem Cells

    Directory of Open Access Journals (Sweden)

    Sharon R. Pine

    2008-01-01

    Full Text Available Lung cancer remains a major cause of cancer-related lethality because of high incidence and recurrence in spite of significant advances in staging and therapies. Recent data indicates that stem cells situated throughout the airways may initiate cancer formation. These putative stem cells maintain protumorigenic characteristics including high proliferative capacity, multipotent differentiation, drug resistance and long lifespan relative to other cells. Stem cell signaling and differentiation pathways are maintained within distinct cancer types, and destabilization of this machinery may participate in maintenance of cancer stem cells. Characterization of lung cancer stem cells is an area of active research and is critical for developing novel therapies. This review summarizes the current knowledge on stem cell signaling pathways and cell markers used to identify the lung cancer stem cells.

  9. Contributions of the Epidermal Growth Factor Receptor to Acquisition of Platinum Resistance in Ovarian Cancer Cells

    OpenAIRE

    Granados, Michaela L.; Hudson, Laurie G.; Samudio-Ruiz, Sabrina L.

    2015-01-01

    Acquisition of platinum resistance following first line platinum/taxane therapy is commonly observed in ovarian cancer patients and prevents clinical effectiveness. There are few options to prevent platinum resistance; however, demethylating agents have been shown to resensitize patients to platinum therapy thereby demonstrating that DNA methylation is a critical contributor to the development of platinum resistance. We previously reported the Epidermal Growth Factor Receptor (EGFR) is a nove...

  10. DNA Methylation-Independent Reversion of Gemcitabine Resistance by Hydralazine in Cervical Cancer Cells

    OpenAIRE

    Candelaria, Myrna; de la Cruz-Hernandez, Erick; Taja-Chayeb, Lucia; Perez-Cardenas, Enrique; Trejo-Becerril, Catalina; Gonzalez-Fierro, Aurora; Chavez-Blanco, Alma; Soto-Reyes, Ernesto; Dominguez, Guadalupe; Trujillo, Jaenai E.; Diaz-Chavez, Jose; Duenas-Gonzalez, Alfonso

    2012-01-01

    Background Down regulation of genes coding for nucleoside transporters and drug metabolism responsible for uptake and metabolic activation of the nucleoside gemcitabine is related with acquired tumor resistance against this agent. Hydralazine has been shown to reverse doxorubicin resistance in a model of breast cancer. Here we wanted to investigate whether epigenetic mechanisms are responsible for acquiring resistance to gemcitabine and if hydralazine could restore gemcitabine sensitivity in ...

  11. Poly(ADP-ribose polymerase 1 (PARP1 overexpression in human breast cancer stem cells and resistance to olaparib.

    Directory of Open Access Journals (Sweden)

    Marine Gilabert

    Full Text Available BACKGROUND: Breast cancer stem cells (BCSCs have been recognized as playing a major role in various aspects of breast cancer biology. To identify specific biomarkers of BCSCs, we have performed comparative proteomics of BCSC-enriched and mature cancer cell populations from the human breast cancer cell line (BCL, BrCA-MZ-01. METHODS: ALDEFLUOR assay was used to sort BCSC-enriched (ALDH+ and mature cancer (ALDH- cell populations. Total proteins were extracted from both fractions and subjected to 2-Dimensional Difference In-Gel Electrophoresis (2-D DIGE. Differentially-expressed spots were excised and proteins were gel-extracted, digested and identified using MALDI-TOF MS. RESULTS: 2-D DIGE identified poly(ADP-ribose polymerase 1 (PARP1 as overexpressed in ALDH+ cells from BrCA-MZ-01. This observation was confirmed by western blot and extended to four additional human BCLs. ALDH+ cells from BRCA1-mutated HCC1937, which had the highest level of PARP1 overexpression, displayed resistance to olaparib, a specific PARP1 inhibitor. CONCLUSION: An unbiased proteomic approach identified PARP1 as upregulated in ALDH+, BCSC-enriched cells from various human BCLs, which may contribute to clinical resistance to PARP inhibitors.

  12. Accumulation of ALDH1-positive cells after neoadjuvant chemotherapy predicts treatment resistance and prognosticates poor outcome in ovarian cancer.

    Science.gov (United States)

    Ayub, Tiyasha H; Keyver-Paik, Mignon-Denise; Debald, Manuel; Rostamzadeh, Babak; Thiesler, Thore; Schröder, Lars; Barchet, Winfried; Abramian, Alina; Kaiser, Christina; Kristiansen, Glen; Kuhn, Walther; Kübler, Kirsten

    2015-06-30

    Although ovarian cancer is a highly chemosensitive disease, it is only infrequently cured. One of the major reasons lies in the presence of drug-resistant cancer stem-like cells, sufficient to fuel recurrence. We phenotyped cancer stem-like cells by flow cytometry and immunohistochemistry in 55 matched samples before and after taxane/platinum-based neoadjuvant chemotherapy. All used markers of stemness (ALDH1, CD24, CD117, CD133) isolated low frequencies of malignant cells. ALDH1 was the most valuable marker for tracking stemness in vivo. The enrichment of ALDH1 expression after treatment was associated with a poor response to chemotherapy, with platinum resistance and independently prognosticated unfavorable outcome. Our results suggest that increased ALDH1 expression after treatment identifies patients with aggressive tumor phenotypes. PMID:25999351

  13. Breast cancer stem cells

    OpenAIRE

    Owens, Thomas W.; Naylor, Matthew J.

    2013-01-01

    Cancer metastasis, resistance to therapies and disease recurrence are significant hurdles to successful treatment of breast cancer. Identifying mechanisms by which cancer spreads, survives treatment regimes and regenerates more aggressive tumors are critical to improving patient survival. Substantial evidence gathered over the last 10 years suggests that breast cancer progression and recurrence is supported by cancer stem cells (CSCs). Understanding how CSCs form and how they contribute to th...

  14. Gene expression and pathway analysis of ovarian cancer cells selected for resistance to cisplatin, paclitaxel, or doxorubicin

    Directory of Open Access Journals (Sweden)

    Sherman-Baust Cheryl A

    2011-12-01

    Full Text Available Abstract Background Resistance to current chemotherapeutic agents is a major cause of therapy failure in ovarian cancer patients, but the exact mechanisms leading to the development of drug resistance remain unclear. Methods To better understand mechanisms of drug resistance, and possibly identify novel targets for therapy, we generated a series of drug resistant ovarian cancer cell lines through repeated exposure to three chemotherapeutic drugs (cisplatin, doxorubicin, or paclitaxel, and identified changes in gene expression patterns using Illumina whole-genome expression microarrays. Validation of selected genes was performed by RT-PCR and immunoblotting. Pathway enrichment analysis using the KEGG, GO, and Reactome databases was performed to identify pathways that may be important in each drug resistance phenotype. Results A total of 845 genes (p Conclusions Ovarian cancer cells develop drug resistance through different pathways depending on the drug used in the generation of chemoresistance. A better understanding of these mechanisms may lead to the development of novel strategies to circumvent the problem of drug resistance.

  15. Requirement of T-lymphokine-activated killer cell-originated protein kinase for TRAIL resistance of human HeLa cervical cancer cells

    International Nuclear Information System (INIS)

    T-lymphokine-activated killer cell-originated protein kinase (TOPK) appears to be highly expressed in various cancer cells and to play an important role in maintaining proliferation of cancer cells. However, the underlying mechanism by which TOPK regulates growth of cancer cells remains elusive. Here we report that upregulated endogenous TOPK augments resistance of cancer cells to apoptosis induced by tumor necrosis factor-related apoptosis inducing ligand (TRAIL). Stable knocking down of TOPK markedly increased TRAIL-mediated apoptosis of human HeLa cervical cancer cells, as compared with control cells. Caspase 8 or caspase 3 activities in response to TRAIL were greatly incremented in TOPK-depleted cells. Ablation of TOPK negatively regulated TRAIL-mediated NF-κB activity. Furthermore, expression of NF-κB-dependent genes, FLICE-inhibitory protein (FLIP), inhibitor of apoptosis protein 1 (c-IAP1), or X-linked inhibitor of apoptosis protein (XIAP) was reduced in TOPK-depleted cells. Collectively, these findings demonstrated that TOPK contributed to TRAIL resistance of cancer cells via NF-κB activity, suggesting that TOPK might be a potential molecular target for successful cancer therapy using TRAIL.

  16. Phenylethyl isothiocyanate reverses cisplatin resistance in biliary tract cancer cells via glutathionylation-dependent degradation of Mcl-1

    Science.gov (United States)

    Li, Qiwei; Zhan, Ming; Chen, Wei; Zhao, Benpeng; Yang, Kai; Yang, Jie; Yi, Jing; Huang, Qihong; Mohan, Man; Hou, Zhaoyuan; Wang, Jian

    2016-01-01

    Biliary tract cancer (BTC) is a highly malignant cancer. BTC exhibits a low response rate to cisplatin (CDDP) treatment, and therefore, an understanding of the mechanism of CDDP resistance is urgently needed. Here, we show that BTC cells develop CDDP resistance due, in part, to upregulation of myeloid cell leukemia 1 (Mcl-1). Phenylethyl isothiocyanate (PEITC), a natural compound found in watercress, could enhance the efficacy of CDDP by degrading Mcl-1. PEITC-CDDP co-treatment also increased the rate of apoptosis of cancer stem-like side population (SP) cells and inhibited xenograft tumor growth without obvious toxic effects. In vitro, PEITC decreased reduced glutathione (GSH), which resulted in decreased GSH/oxidized glutathione (GSSG) ratio and increased glutathionylation of Mcl-1, leading to rapid proteasomal degradation of Mcl-1. Furthermore, we identified Cys16 and Cys286 as Mcl-1 glutathionylation sites, and mutating them resulted in PEITC-mediated degradation resistant Mcl-1 protein. In conclusion, we demonstrate for the first time that CDDP resistance is partially associated with Mcl-1 in BTC cells and we identify a novel mechanism that PEITC can enhance CDDP-induced apoptosis via glutathionylation-dependent degradation of Mcl-1. Hence, our results provide support that dietary intake of watercress may help reverse CDDP resistance in BTC patients. PMID:26848531

  17. Anticancer Effects of the Nitric Oxide-Modified Saquinavir Derivative Saquinavir-NO against Multidrug-Resistant Cancer Cells

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    Florian Rothweiler

    2010-12-01

    Full Text Available The human immunodeficiency virus (HIV protease inhibitor saquinavir shows anticancer activity. Although its nitric oxide-modified derivative saquinavir-NO (saq-NO was less toxic to normal cells, it exerted stronger inhibition of B16 melanoma growth in syngeneic C57BL/6 mice than saquinavir did. Saq-NO has been shown to block proliferation, upregulate p53 expression, and promote differentiation of C6 glioma and B16 cells. The anticancer activity of substances is frequently hampered by cancer cell chemoresistance mechanisms. Therefore, we here investigated the roles of p53 and the ATP-binding cassette (ABC transporters P-glycoprotein (P-gp, multidrug resistance-associated protein 1 (MRP1, and breast cancer resistance protein 1 (BCRP1 in cancer cell sensitivity to saq-NO to get more information about the potential of saq-NO as anticancer drug. Saq-NO exerted anticancer effects in lower concentrations than saquinavir in a panel of human cancer cell lines. Neither p53 mutation or depletion nor expression of P-gp, MRP1, or BCRP1 affected anticancer activity of saq-NO or saquinavir. Moreover, saq-NO sensitized P-gp-, MRP1-, or BCRP1-expressing cancer cells to chemotherapy. Saq-NO induced enhanced sensitization of P-gp- or MRP1-expressing cancer cells to chemotherapy compared with saquinavir, whereas both substances similarly sensitized BCRP1-expressing cells. Washout kinetics and ABC transporter ATPase activities demonstrated that saq-NO is a substrate of P-gp as well as of MRP1. These data support the further investigation of saq-NO as an anticancer drug, especially in multidrug-resistant tumors.

  18. Genipin-induced inhibition of uncoupling protein-2 sensitizes drug-resistant cancer cells to cytotoxic agents.

    Directory of Open Access Journals (Sweden)

    Ryan J Mailloux

    Full Text Available Uncoupling protein-2 (UCP2 is known to suppress mitochondrial reactive oxygen species (ROS production and is employed by drug-resistant cancer cells to mitigate oxidative stress. Using the drug-sensitive HL-60 cells and the drug-resistant MX2 subline as model systems, we show that genipin, a UCP2 inhibitor, sensitizes drug-resistant cells to cytotoxic agents. Increased MX2 cell death was observed upon co-treatment with genipin and different doses of menadione, doxorubicin, and epirubicin. DCFH-DA fluorimetry revealed that the increase in MX2 cell death was accompanied by enhanced cellular ROS levels. The drug-induced increase in ROS was linked to genipin-mediated inhibition of mitochondrial proton leak. State 4 and resting cellular respiratory rates were higher in the MX2 cells in comparison to the HL-60 cells, and the increased respiration was readily suppressed by genipin in the MX2 cells. UCP2 accounted for a remarkable 37% of the resting cellular oxygen consumption indicating that the MX2 cells are functionally reliant on this protein. Higher amounts of UCP2 protein were detected in the MX2 versus the HL-60 mitochondria. The observed effects of genipin were absent in the HL-60 cells pointing to the selectivity of this natural product for drug-resistant cells. The specificity of genipin for UCP2 was confirmed using CHO cells stably expressing UCP2 in which genipin induced an ∼22% decrease in state 4 respiration. These effects were absent in empty vector CHO cells expressing no UCP2. Thus, the chemical inhibition of UCP2 with genipin sensitizes multidrug-resistant cancer cells to cytotoxic agents.

  19. Sustained Epigenetic Drug Delivery Depletes Cholesterol-Sphingomyelin Rafts from Resistant Breast Cancer Cells, Influencing Biophysical Characteristics of Membrane Lipids.

    Science.gov (United States)

    Raghavan, Vijay; Vijayaraghavalu, Sivakumar; Peetla, Chiranjeevi; Yamada, Masayoshi; Morisada, Megan; Labhasetwar, Vinod

    2015-10-27

    Cell-membrane lipid composition can greatly influence biophysical properties of cell membranes, affecting various cellular functions. We previously showed that lipid synthesis becomes altered in the membranes of resistant breast cancer cells (MCF-7/ADR); they form a more rigid, hydrophobic lipid monolayer than do sensitive cell membranes (MCF-7). These changes in membrane lipids of resistant cells, attributed to epigenetic aberration, significantly affected drug transport and endocytic function, thus impacting the efficacy of anticancer drugs. The present study's objective was to determine the effects of the epigenetic drug, 5-aza-2'-deoxycytidine (DAC), delivered in sustained-release nanogels (DAC-NGs), on the composition and biophysical properties of membrane lipids of resistant cells. Resistant and sensitive cells were treated with DAC in solution (DAC-sol) or DAC-NGs, and cell-membrane lipids were isolated and analyzed for lipid composition and biophysical properties. In resistant cells, we found increased formation of cholesterol-sphingomyelin (CHOL-SM) rafts with culturing time, whereas DAC treatment reduced their formation. In general, the effect of DAC-NGs was greater in changing the lipid composition than with DAC-sol. DAC treatment also caused a rise in levels of certain phospholipids and neutral lipids known to increase membrane fluidity, while reducing the levels of certain lipids known to increase membrane rigidity. Isotherm data showed increased lipid membrane fluidity following DAC treatment, attributed to decrease levels of CHOL-SM rafts (lamellar beta [Lβ] structures or ordered gel) and a corresponding increase in lipids that form lamellar alpha-structures (Lα, liquid crystalline phase). Sensitive cells showed marginal or insignificant changes in lipid profile following DAC-treatment, suggesting that epigenetic changes affecting lipid biosynthesis are more specific to resistant cells. Since membrane fluidity plays a major role in drug transport

  20. The phenomenon of acquired resistance to metformin in breast cancer cells: The interaction of growth pathways and estrogen receptor signaling.

    Science.gov (United States)

    Scherbakov, Alexander M; Sorokin, Danila V; Tatarskiy, Victor V; Prokhorov, Nikolay S; Semina, Svetlana E; Berstein, Lev M; Krasil'nikov, Mikhail A

    2016-04-01

    Metformin, a biguanide antidiabetic drug, is used to decrease hyperglycemia in patients with type 2 diabetes. Recently, the epidemiological studies revealed the potential of metformin as an anti-tumor drug for several types of cancer, including breast cancer. Anti-tumor metformin action was found to be mediated, at least in part, via activation of adenosine monophosphate-activated protein kinase (AMPK)-intracellular energy sensor, which inhibits the mammalian target of rapamycin (mTOR) and some other signaling pathways. Nevertheless, some patients can be non-sensitive or resistant to metformin action. Here we analyzed the mechanism of the formation of metformin-resistant phenotype in breast cancer cells and its role in estrogen receptor (ER) regulation. The experiments were performed on the ER-positive MCF-7 breast cancer cells and metformin-resistant MCF-7 subline (MCF-7/M) developed due to long-term metformin treatment. The transcriptional activity of NF-κB and ER was measured by the luciferase reporter gene analysis. The protein expression was determined by immunoblotting (Snail1, (phospho)AMPK, (phospho)IκBα, (phospho)mTOR, cyclin D1, (phospho)Akt and ERα) and immunohistochemical analysis (E-cadherin). We have found that: 1) metformin treatment of MCF-7 cells is accompanied with the stimulation of AMPK and inhibition of growth-related proteins including IκBα, NF-κB, cyclin D1 and ERα; 2) long-term metformin treatment lead to the appearance and progression of cross-resistance to metformin and tamoxifen; the resistant cells are characterized with the unaffected AMPK activity, but the irreversible ER suppression and constitutive activation of Akt/Snail1 signaling; 3) Akt/Snail1 signaling is involved into progression of metformin resistance. The results presented may be considered as the first evidence of the progression of cross-resistance to metformin and tamoxifen in breast cancer cells. Importantly, the acquired resistance to both drugs is based on the

  1. Downregulation of CD44 reduces doxorubicin resistance of CD44+CD24- breast cancer cells

    Directory of Open Access Journals (Sweden)

    Phuc PV

    2011-06-01

    Full Text Available Pham Van Phuc, Phan Lu Chinh Nhan, Truong Hai Nhung, Nguyen Thanh Tam, Nguyen Minh Hoang, Vuong Gia Tue, Duong Thanh Thuy, Phan Kim NgocLaboratory of Stem Cell Research and Application, University of Science, Vietnam National University, Ho Chi Minh, VietnamBackground: Cells within breast cancer stem cell populations have been confirmed to have a CD44+CD24- phenotype. Strong expression of CD44 plays a critical role in numerous types of human cancers. CD44 is involved in cell differentiation, adhesion, and metastasis of cancer cells.Methods: In this study, we reduced CD44 expression in CD44+CD24- breast cancer stem cells and investigated their sensitivity to an antitumor drug. The CD44+CD24- breast cancer stem cells were isolated from breast tumors; CD44 expression was downregulated with siRNAs followed by treatment with different concentrations of the antitumor drug.Results: The proliferation of CD44 downregulated CD44+CD24- breast cancer stem cells was decreased after drug treatment. We noticed treated cells were more sensitive to doxorubicin, even at low doses, compared with the control groups.Conclusions: It would appear that expression of CD44 is integral among the CD44+CD24- cell population. Reducing the expression level of CD44, combined with doxorubicin treatment, yields promising results for eradicating breast cancer stem cells in vitro. This study opens a new direction in treating breast cancer through gene therapy in conjunction with chemotherapy.Keywords: antitumor drugs, breast cancer stem cells, CD44, CD44+CD24- cells, doxorubicin

  2. IGFBP2/FAK pathway is causally associated with dasatinib resistance in non-small Cell Lung Cancer Cells

    OpenAIRE

    Lu, Haibo; Wang, Li; Gao, Wen; Meng, Jieru; Dai, Bingbing; Wu, Shuhong; Minna, John; Roth, Jack A.; Hofstetter, Wayne L.; Swisher, Stephen G.; Fang, Bingliang

    2013-01-01

    IGFBP2 expression is increased in various types of cancers, including in a subset of lung cancer patients. Because IGFBP2 is involved in signal transduction of some critical cancer related pathways, we analyzed the association between IGFBP2 and response to pathway-targeted agents in seven human non–small cell lung cancer (NSCLC) cell lines. Western blot analysis and enzyme-linked immunosorbent assay (ELISA) showed that four of the seven NSCLC cell lines analyzed expressed high levels of IGFB...

  3. Non-alkaloids extract from Stemona sessilifolia enhances the activity of chemotherapeutic agents through P-glycoprotein-mediated multidrug-resistant cancer cells.

    Science.gov (United States)

    Han, Lu; Ma, Yang-Mei; An, Li; Zhang, Qiao; Wang, Chang-Li; Zhao, Qing-Chun

    2016-01-01

    One of the major impediments to the successful treatment of cancer is the development of resistant cancer cells, which could cause multidrug resistance (MDR), and overexpression of ABCB1/P-glycoprotein (P-gp) is one of the most common causes of MDR in cancer cells. Recently, natural products or plant-derived chemicals have been investigated more and more widely as potential multidrug-resistant (MDR) reversing agents. The current study demonstrated for the first time that non-alkaloids extract from Stemona sessilifolia significantly reversed the resistance of chemotherapeutic agents, adriamycin, paclitaxel and vincristine to MCF-7/ADR cells compared with MCF-7/S cells in a dose-dependent manner. The results obtained from these studies indicated that the non-alkaloids extract from S. sessilifolia plays an important role in reversing MDR of cancer as a P-gp modulator in vitro and may be effective in the treatment of multidrug-resistant cancers. PMID:26190165

  4. [Proteins in cancer multidrug resistance].

    Science.gov (United States)

    Popęda, Marta; Płuciennik, Elżbieta; Bednarek, Andrzej K

    2014-01-01

    Multidrug Resistance (MDR) is defined as insensitivity to administered medicines that are structurally unrelated and have different molecular targets. Cancers possess numerous mechanisms of drug resistance, involving various aspects of cell biology. A pivotal role in this phenomenon is played by proteins--enzymatic or structural parts of the cell. Membrane transporters, including the main members of ABC protein family--P-gp, MRP1 and BCRP, as well as LRP, which builds structure of vaults, determine the multidrug-resistant phenotype by decreasing drug concentration within the cell or modifying its distribution to intracellular compartments. The π isoform of protein enzyme--glutathione S-transferase (GSTP-1), is responsible for excessive intensity of detoxification of cytostatics. A common example of altered drug target site that does not respond to chemotherapy is topoisomerase II α (TopoIIa). Alterations of programmed cell death result from expression of metallothionein (MT)--inhibitor of the process, and cytokeratin 18 (CK18), which, if in high concentration, also prevents apoptosis of cells. Several methods of decreasing activity of these proteins have been developed, aiming to overcome MDR in cancer cells. However, for a variety of reasons, their clinical suitability is still very low, leading to continuous increase in death rate among patients. This paper presents current state of knowledge on the most important examples of proteins responsible for MDR of cancer cells and molecular mechanisms of their action. PMID:24864112

  5. HOXC10 Expression Supports the Development of Chemotherapy Resistance by Fine Tuning DNA Repair in Breast Cancer Cells.

    Science.gov (United States)

    Sadik, Helen; Korangath, Preethi; Nguyen, Nguyen K; Gyorffy, Balazs; Kumar, Rakesh; Hedayati, Mohammad; Teo, Wei Wen; Park, Sunju; Panday, Hardik; Munoz, Teresa Gonzalez; Menyhart, Otilia; Shah, Nilay; Pandita, Raj K; Chang, Jenny C; DeWeese, Theodore; Chang, Howard Y; Pandita, Tej K; Sukumar, Saraswati

    2016-08-01

    Development of drug resistance is a major factor limiting the continued success of cancer chemotherapy. To overcome drug resistance, understanding the underlying mechanism(s) is essential. We found that HOXC10 is overexpressed in primary carcinomas of the breast, and even more significantly in distant metastasis arising after failed chemotherapy. High HOXC10 expression correlates with shorter recurrence-free and overall survival in patients with estrogen receptor-negative breast cancer undergoing chemotherapy. We found that HOXC10 promotes survival in cells treated with doxorubicin, paclitaxel, or carboplatin by suppressing apoptosis and upregulating NF-κB Overexpressed HOXC10 increases S-phase-specific DNA damage repair by homologous recombination (HR) and checkpoint recovery in cells at three important phases. For double-strand break repair, HOXC10 recruits HR proteins at sites of DNA damage. It enhances resection and lastly, it resolves stalled replication forks, leading to initiation of DNA replication following DNA damage. We show that HOXC10 facilitates, but is not directly involved in DNA damage repair mediated by HR. HOXC10 achieves integration of these functions by binding to, and activating cyclin-dependent kinase, CDK7, which regulates transcription by phosphorylating the carboxy-terminal domain of RNA polymerase II. Consistent with these findings, inhibitors of CDK7 reverse HOXC10-mediated drug resistance in cultured cells. Blocking HOXC10 function, therefore, presents a promising new strategy to overcome chemotherapy resistance in breast cancer. Cancer Res; 76(15); 4443-56. ©2016 AACR. PMID:27302171

  6. The Adipocyte-Derived Hormone Leptin Has Proliferative Actions on Androgen-Resistant Prostate Cancer Cells Linking Obesity to Advanced Stages of Prostate Cancer

    Directory of Open Access Journals (Sweden)

    M. Raschid Hoda

    2012-01-01

    Full Text Available Background. Because obesity may be a risk factor for prostate cancer, we investigated proliferative effects of adipocytes-derived hormone leptin on human prostate cancer cells and assessed the role of mitogen-activated protein kinase (MAPK signaling pathway in mediating these actions. Material and Methods. Three human prostate cancer cell lines were treated with increasing doses of recombinant leptin. Cell growth was measured under serum-free conditions using a spectrophotometric assay. Further, Western blotting was applied to detect the phosphorylation of an ERK1/2, and a specific inhibitor of MAPK (PD98059; 40 μM was used. Results. In both androgen-resistant cell lines DU145 and PC-3, cell growth was dose-dependently increased by leptin after 24 hrs and 48 hrs of incubation, whereas leptin’s proliferative effects on androgen-sensitive cell line LNCaP was less pronounced. Further, leptin caused dose-dependent ERK1/2 phosphorylation in both androgen-resistant cell lines, and pretreatment of these cells with PD98059 inhibited these responses. Conclusions. Leptin may be a potential link between obesity and risk of progression of prostate cancer. Thus, studies on leptin and obesity association to prostate cancer should differentiate patients according to androgen sensitivity.

  7. Anticancer effect of metformin on estrogen receptor-positive and tamoxifen-resistant breast cancer cell lines.

    Science.gov (United States)

    Kim, Jinkyoung; Lee, Jiyun; Jang, Soon Young; Kim, Chungyeul; Choi, Yoojin; Kim, Aeree

    2016-05-01

    Acquisition of tamoxifen resistance (TR) during anti-estrogenic therapy using tamoxifen is a major obstacle in the treatment of estrogen receptor (ER)-positive breast cancer. As a biguanide derivative, metformin is commonly used to treat type II diabetes. It has recently emerged as a potential anticancer agent. The objective of the present study was to investigate the anticancer activity of metformin in relation to ERα expression and its signaling pathway in ERα-positive MCF-7 and MDA-MB-361 breast cancer cells as well as TR MCF-7 breast cancer cells. Metformin inhibited both protein and mRNA levels of ERα in the presence or absence of estrogen (E2) in the MCF-7, TR MCF-7 and MDA-MB-361 cells. Metformin repressed E2-inducible estrogen response element (ERE) luciferase activity, protein levels and mRNA levels of E2/ERα-regulated genes [including c-Myc, cyclin D1, progesterone receptor (PR) and pS2] to a greater degree than tamoxifen, resulting in inhibition of cell proliferation of MCF-7, TR MCF-7 and MDA-MB-361 cells. Collectively, our results suggest that one of the anticancer mechanisms of metformin could be attributable to the repression of expression and transcriptional activity of ERα. Metformin may be a good therapeutic agent for treating ERα-positive breast cancer by inhibiting the expression and function of ERα. In addition, metformin may be useful to treat tamoxifen-resistant breast cancer. PMID:26986571

  8. Cancer Cell Resistance to Aurora Kinase Inhibitors: Identification of Novel Targets for Cancer Therapy

    Czech Academy of Sciences Publication Activity Database

    Hrabáková, Rita; Kollaredy, M.; Tylečková, Jiřina; Halada, Petr; Hajdúch, M.; Gadher, S. J.; Kovářová, Hana

    2013-01-01

    Roč. 12, č. 1 (2013), s. 455-469. ISSN 1535-3893 R&D Projects: GA MŠk LC07017 Institutional support: RVO:67985904 ; RVO:61388971 Keywords : Aurora kinase inhibitors * resistance * p53 * apoptosis Subject RIV: CE - Biochemistry Impact factor: 5.001, year: 2013

  9. Insulin-like growth factor binding protein 2 is a marker for antiestrogen resistant human breast cancer cell lines but is not a major growth regulator

    DEFF Research Database (Denmark)

    Juncker-Jensen, A; Lykkesfeldt, A E; Worm, J;

    2006-01-01

    Antiestrogens target the estrogen receptor and counteract the growth stimulatory action of estrogen on human breast cancer. However, acquired resistance to antiestrogens is a major clinical problem in endocrine treatment of breast cancer patients. To mimic acquired resistance, we have used a mode...... resistant cell growth was observed. Thus, we were able to establish IGFBP-2 as a marker for antiestrogen resistant breast cancer cell lines, although IGFBP-2 was not a major contributor to the resistant cell growth.......Antiestrogens target the estrogen receptor and counteract the growth stimulatory action of estrogen on human breast cancer. However, acquired resistance to antiestrogens is a major clinical problem in endocrine treatment of breast cancer patients. To mimic acquired resistance, we have used a model...... system with the antiestrogen sensitive human breast cancer cell line MCF-7 and several antiestrogen resistant cell lines derived from the parental MCF-7 cell line. This model system was used to study the expression and possible involvement in resistant cell growth of insulin-like growth factor binding...

  10. Elevated STAT3 Signaling-Mediated Upregulation of MMP-2/9 Confers Enhanced Invasion Ability in Multidrug-Resistant Breast Cancer Cells

    Directory of Open Access Journals (Sweden)

    Fei Zhang

    2015-10-01

    Full Text Available The development of multidrug resistance greatly impedes effective cancer therapy. Recent advances in cancer research have demonstrated that acquisition of multidrug resistance by cancer cells is usually accompanied by enhanced cell invasiveness. Several lines of evidence indicated that cross activation of other signaling pathways during development of drug resistance may increase invasive potential of multidrug-resistant (MDR cancer cells. However, the accurate mechanism of this process is largely undefined. In this study, to better understand the associated molecular pathways responsible for cancer progression induced by drug resistance, a MDR human breast cancer cell line SK-BR-3/EPR with P-glycoprotein overexpression was established using stepwise long-term exposure to increasing concentration of epirubicin. The SK-BR-3/EPR cell line exhibited decreased cell proliferative activity, but enhanced cell invasive capacity. We showed that the expression of metastasis-related matrix metalloproteinase (MMP-2/9 was elevated in SK-BR-3/EPR cells. Moreover, SK-BR-3/EPR cells showed elevated activation of STAT3. Activation of STAT3 signaling is responsible for enhanced invasiveness of SK-BR-3/EPR cells through upregulation of MMP-2/9. STAT3 is a well-known oncogene and is frequently implicated in tumorigenesis and chemotherapeutic resistance. Our findings augment insight into the mechanism underlying the functional association between MDR and cancer invasiveness.

  11. miR-193a-3p regulation of chemoradiation resistance in oesophageal cancer cells via the PSEN1 gene.

    Science.gov (United States)

    Meng, Fang; Qian, Liting; Lv, Lei; Ding, Bojin; Zhou, Gieping; Cheng, Xu; Niu, Sanqiang; Liang, Yu

    2016-04-01

    Chemoradiation therapy is an important component of the curative treatment for oesophageal carcinomas. These therapeutic effects are prevented in patients according to radioresistance and multi-drug resistance, and the cause of such resistance remains unclear. In this study, we identified the role of miR-193a-3p in modulating the radioresistance and chemoresistance of oesophageal cancer cells. We found that KYSE150 and KYSE410 cells could be characterized as relatively radiation-sensitive and radiation-resistant cells, respectively. Similarly, KYSE150 and KYSE410 cells were found to be chemosensitive and chemoresistant, respectively. Over-expression of miR-193a-3p increased the radioresistance and chemoresistance of oesophageal squamous cell carcinoma (ESCC) cells. In contrast, the down-regulation of miR-193a-3p decreased the radioresistance and chemoresistance of ESCC cells. In addition, miR-193a-3p inducing DNA damage has also been demonstrated through measuring the level of gamma-H2AX associated with miR-193a-3p. Moreover, a small interfering RNA(siRNA)-induced repression of the PSEN1 gene had an effect similar to that of miR-193a-3p up-regulation. The above processes also inhibited oesophageal cancer cells apoptosis. These findings suggest that miR-193a-3p contributes to the radiation and chemotherapy resistance of oesophageal carcinoma by down-regulating PSEN1. Thus, miR-193a-3p and PSEN1 might be potential biomarkers for chemoradiation resistant cancers. PMID:26743123

  12. Thymoquinone up-regulates PTEN expression and induces apoptosis in doxorubicin-resistant human breast cancer cells

    International Nuclear Information System (INIS)

    The use of innocuous naturally occurring compounds to overcome drug resistance and cancer recalcitrance is now in the forefront of cancer research. Thymoquinone (TQ) is a bioactive constituent of the volatile oil derived from seeds of Nigella sativa Linn. TQ has shown promising anti-carcinogenic and anti-tumor activities through different mechanisms. However, the effect of TQ on cell signaling and survival pathways in resistant cancer cells has not been fully delineated. Here, we report that TQ greatly inhibits doxorubicin-resistant human breast cancer MCF-7/DOX cell proliferation. TQ treatment increased cellular levels of PTEN proteins, resulting in a substantial decrease of phosphorylated Akt, a known regulator of cell survival. The PTEN expression was accompanied with elevation of PTEN mRNA. TQ arrested MCF-7/DOX cells at G2/M phase and increased cellular levels of p53 and p21 proteins. Flow cytometric analysis and agarose gel electrophoresis revealed a significant increase in Sub-G1 cell population and appearance of DNA ladders following TQ treatment, indicating cellular apoptosis. TQ-induced apoptosis was associated with disrupted mitochondrial membrane potential and activation of caspases and PARP cleavage in MCF-7/DOX cells. Moreover, TQ treatment increased Bax/Bcl2 ratio via up-regulating Bax and down-regulating Bcl2 proteins. More importantly, PTEN silencing by target specific siRNA enabled the suppression of TQ-induced apoptosis resulting in increased cell survival. Our results reveal that up-regulation of the key upstream signaling factor, PTEN, in MCF-7/DOX cells inhibited Akt phosphorylation, which ultimately causes increase in their regulatory p53 levels affecting the induction of G2/M cell cycle arrest and apoptosis. Overall results provide mechanistic insights for understanding the molecular basis and utility of the anti-tumor activity of TQ.

  13. Thymoquinone up-regulates PTEN expression and induces apoptosis in doxorubicin-resistant human breast cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Arafa, El-Shaimaa A.; Zhu Qianzheng [Department of Radiology, Ohio State University, Columbus, OH 43210 (United States); Shah, Zubair I. [James Cancer Hospital and Solove Research Institute, Ohio State University, Columbus, OH 43210 (United States); Wani, Gulzar; Barakat, Bassant M.; Racoma, Ira [Department of Radiology, Ohio State University, Columbus, OH 43210 (United States); El-Mahdy, Mohamed A., E-mail: Mohamed.el-mahdy@osumc.edu [Department of Radiology, Ohio State University, Columbus, OH 43210 (United States); Wani, Altaf A., E-mail: wani.2@osu.edu [Department of Radiology, Ohio State University, Columbus, OH 43210 (United States); Department of Molecular and Cellular Biochemistry, Ohio State University, Columbus, OH 43210 (United States); James Cancer Hospital and Solove Research Institute, Ohio State University, Columbus, OH 43210 (United States); DNA Research Chair, King Saud University, Riyadh (Saudi Arabia)

    2011-01-10

    The use of innocuous naturally occurring compounds to overcome drug resistance and cancer recalcitrance is now in the forefront of cancer research. Thymoquinone (TQ) is a bioactive constituent of the volatile oil derived from seeds of Nigella sativa Linn. TQ has shown promising anti-carcinogenic and anti-tumor activities through different mechanisms. However, the effect of TQ on cell signaling and survival pathways in resistant cancer cells has not been fully delineated. Here, we report that TQ greatly inhibits doxorubicin-resistant human breast cancer MCF-7/DOX cell proliferation. TQ treatment increased cellular levels of PTEN proteins, resulting in a substantial decrease of phosphorylated Akt, a known regulator of cell survival. The PTEN expression was accompanied with elevation of PTEN mRNA. TQ arrested MCF-7/DOX cells at G2/M phase and increased cellular levels of p53 and p21 proteins. Flow cytometric analysis and agarose gel electrophoresis revealed a significant increase in Sub-G1 cell population and appearance of DNA ladders following TQ treatment, indicating cellular apoptosis. TQ-induced apoptosis was associated with disrupted mitochondrial membrane potential and activation of caspases and PARP cleavage in MCF-7/DOX cells. Moreover, TQ treatment increased Bax/Bcl2 ratio via up-regulating Bax and down-regulating Bcl2 proteins. More importantly, PTEN silencing by target specific siRNA enabled the suppression of TQ-induced apoptosis resulting in increased cell survival. Our results reveal that up-regulation of the key upstream signaling factor, PTEN, in MCF-7/DOX cells inhibited Akt phosphorylation, which ultimately causes increase in their regulatory p53 levels affecting the induction of G2/M cell cycle arrest and apoptosis. Overall results provide mechanistic insights for understanding the molecular basis and utility of the anti-tumor activity of TQ.

  14. Functional ablation of pRb activates Cdk2 and causes antiestrogen resistance in human breast cancer cells.

    Directory of Open Access Journals (Sweden)

    Hemant Varma

    Full Text Available Estrogens are required for the proliferation of hormone dependent breast cancer cells, making estrogen receptor (ER positive tumors amenable to endocrine therapies such as antiestrogens. However, resistance to these agents remains a significant cause of treatment failure. We previously demonstrated that inactivation of the retinoblastoma protein (pRb family tumor suppressors causes antiestrogen resistance in MCF-7 cells, a widely studied model of estrogen responsive human breast cancers. In this study, we investigate the mechanism by which pRb inactivation leads to antiestrogen resistance. Cdk4 and cdk2 are two key cell cycle regulators that can phosphorylate and inactivate pRb, therefore we tested whether these kinases are required in cells lacking pRb function. pRb family members were inactivated in MCF-7 cells by expressing polyomavirus large tumor antigen (PyLT, and cdk activity was inhibited using the cdk inhibitors p16(INK4A and p21(Waf1/Cip1. Cdk4 activity was no longer required in cells lacking functional pRb, while cdk2 activity was required for proliferation in both the presence and absence of pRb function. Using inducible PyLT cell lines, we further demonstrated that pRb inactivation leads to increased cyclin A expression, cdk2 activation and proliferation in antiestrogen arrested cells. These results demonstrate that antiestrogens do not inhibit cdk2 activity or proliferation of MCF-7 cells in the absence of pRb family function, and suggest that antiestrogen resistant breast cancer cells resulting from pRb pathway inactivation would be susceptible to therapies that target cdk2.

  15. P-glycoprotein Mediates Ceritinib Resistance in Anaplastic Lymphoma Kinase-rearranged Non-small Cell Lung Cancer

    Science.gov (United States)

    Katayama, Ryohei; Sakashita, Takuya; Yanagitani, Noriko; Ninomiya, Hironori; Horiike, Atsushi; Friboulet, Luc; Gainor, Justin F.; Motoi, Noriko; Dobashi, Akito; Sakata, Seiji; Tambo, Yuichi; Kitazono, Satoru; Sato, Shigeo; Koike, Sumie; John Iafrate, A.; Mino-Kenudson, Mari; Ishikawa, Yuichi; Shaw, Alice T.; Engelman, Jeffrey A.; Takeuchi, Kengo; Nishio, Makoto; Fujita, Naoya

    2015-01-01

    The anaplastic lymphoma kinase (ALK) fusion oncogene is observed in 3%–5% of non-small cell lung cancer (NSCLC). Crizotinib and ceritinib, a next-generation ALK tyrosine kinase inhibitor (TKI) active against crizotinib-refractory patients, are clinically available for the treatment of ALK-rearranged NSCLC patients, and multiple next-generation ALK-TKIs are currently under clinical evaluation. These ALK-TKIs exhibit robust clinical activity in ALK-rearranged NSCLC patients; however, the emergence of ALK-TKI resistance restricts the therapeutic effect. To date, various secondary mutations or bypass pathway activation-mediated resistance have been identified, but large parts of the resistance mechanism are yet to be identified. Here, we report the discovery of p-glycoprotein (P-gp/ABCB1) overexpression as a ceritinib resistance mechanism in ALK-rearranged NSCLC patients. P-gp exported ceritinib and its overexpression conferred ceritinib and crizotinib resistance, but not to PF-06463922 or alectinib, which are next-generation ALK inhibitors. Knockdown of ABCB1 or P-gp inhibitors sensitizes the patient-derived cancer cells to ceritinib, in vitro and in vivo. P-gp overexpression was identified in three out of 11 cases with in ALK-rearranged crizotinib or ceritinib resistant NSCLC patients. Our study suggests that alectinib, PF-06463922, or P-gp inhibitor with ceritinib could overcome the ceritinib or crizotinib resistance mediated by P-gp overexpression. PMID:26870817

  16. P-glycoprotein Mediates Ceritinib Resistance in Anaplastic Lymphoma Kinase-rearranged Non-small Cell Lung Cancer

    Directory of Open Access Journals (Sweden)

    Ryohei Katayama

    2016-01-01

    Full Text Available The anaplastic lymphoma kinase (ALK fusion oncogene is observed in 3%–5% of non-small cell lung cancer (NSCLC. Crizotinib and ceritinib, a next-generation ALK tyrosine kinase inhibitor (TKI active against crizotinib-refractory patients, are clinically available for the treatment of ALK-rearranged NSCLC patients, and multiple next-generation ALK-TKIs are currently under clinical evaluation. These ALK-TKIs exhibit robust clinical activity in ALK-rearranged NSCLC patients; however, the emergence of ALK-TKI resistance restricts the therapeutic effect. To date, various secondary mutations or bypass pathway activation-mediated resistance have been identified, but large parts of the resistance mechanism are yet to be identified. Here, we report the discovery of p-glycoprotein (P-gp/ABCB1 overexpression as a ceritinib resistance mechanism in ALK-rearranged NSCLC patients. P-gp exported ceritinib and its overexpression conferred ceritinib and crizotinib resistance, but not to PF-06463922 or alectinib, which are next-generation ALK inhibitors. Knockdown of ABCB1 or P-gp inhibitors sensitizes the patient-derived cancer cells to ceritinib, in vitro and in vivo. P-gp overexpression was identified in three out of 11 cases with in ALK-rearranged crizotinib or ceritinib resistant NSCLC patients. Our study suggests that alectinib, PF-06463922, or P-gp inhibitor with ceritinib could overcome the ceritinib or crizotinib resistance mediated by P-gp overexpression.

  17. Human carcinoma-associated mesenchymal stem cells promote ovarian cancer chemotherapy resistance via a BMP4/HH signaling loop

    Science.gov (United States)

    Coffman, Lan G.; Choi, Yun-Jung; McLean, Karen; Allen, Benjamin L.; di Magliano, Marina Pasca; Buckanovich, Ronald J.

    2016-01-01

    The tumor microenvironment is critical to cancer growth and therapy resistance. We previously characterized human ovarian carcinoma-associated mesenchymal stem cells (CA-MSCs). CA-MSCs are multi-potent cells that can differentiate into tumor microenvironment components including fibroblasts, myofibroblasts and adipocytes. We previously reported CA-MSCs, compared to normal MSCs, express high levels of BMP proteins and promote tumor growth by increasing numbers of cancer stem-like cells (CSCs). We demonstrate here that ovarian tumor cell-secreted Hedgehog (HH) induces CA-MSC BMP4 expression. CA-MSC-derived BMP4 reciprocally increases ovarian tumor cell HH expression indicating a positive feedback loop. Interruption of this loop with a HH pathway inhibitor or BMP4 blocking antibody decreases CA-MSC-derived BMP4 and tumor-derived HH preventing enrichment of CSCs and reversing chemotherapy resistance. The impact of HH inhibition was only seen in CA-MSC-containing tumors, indicating the importance of a humanized stroma. These results are reciprocal to findings in pancreatic and bladder cancer, suggesting HH signaling effects are tumor tissue specific warranting careful investigation in each tumor type. Collectively, we define a critical positive feedback loop between CA-MSC-derived BMP4 and ovarian tumor cell-secreted HH and present evidence for the further investigation of HH as a clinical target in ovarian cancer. PMID:26755648

  18. Oct4 plays a crucial role in the maintenance of gefitinib-resistant lung cancer stem cells.

    Science.gov (United States)

    Kobayashi, Isao; Takahashi, Fumiyuki; Nurwidya, Fariz; Nara, Takeshi; Hashimoto, Muneaki; Murakami, Akiko; Yagishita, Shigehiro; Tajima, Ken; Hidayat, Moulid; Shimada, Naoko; Suina, Kentaro; Yoshioka, Yasuko; Sasaki, Shinichi; Moriyama, Mariko; Moriyama, Hiroyuki; Takahashi, Kazuhisa

    2016-04-22

    Several recent studies have suggested that cancer stem cells (CSCs) are involved in resistance to gefitinib in non-small cell lung cancer (NSCLC). Oct4, a member of the POU-domain transcription factor family, has been shown to be involved in CSC properties of various cancers. We previously reported that Oct4 and the putative lung CSC marker CD133 were highly expressed in gefitinib-resistant persisters (GRPs) in NSCLC cells, and GRPs exhibited characteristic features of the CSCs phenotype. The aim of this study was to elucidate the role of Oct4 in the resistance to gefitinib in NSCLC cells with an activating epidermal growth factor receptor (EGFR) mutation. NSCLC cell lines, PC9, which express the EGFR exon 19 deletion mutation, were transplanted into NOG mice, and were treated with gefitinib in vivo. After 14-17 days of gefitinib treatment, the tumors still remained; these tumors were referred to as gefitinib-resistant tumors (GRTs). PC9-GRTs showed higher expression of Oct4 and CD133. To investigate the role of Oct4 in the maintenance of gefitinib-resistant lung CSCs, we introduced the Oct4 gene into PC9 and HCC827 cells carrying an activating EGFR mutation by lentiviral infection. Transfection of Oct4 significantly increased CD133-positive GRPs and the number of sphere formation, reflecting the self-renewal activity, of PC9 and HCC827 cells under the high concentration of gefitinib in vitro. Furthermore, Oct4-overexpressing PC9 cells (PC9-Oct4) significantly formed tumors at 1 × 10 cells/injection in NOG mice as compared to control cells. In addition, PC9-Oct4 tumors were more resistant to gefitinib treatment as compared to control cells in vivo. Finally, immunohistochemical analysis revealed that Oct4 was highly expressed in tumor specimens of EGFR-mutant NSCLC patients with acquired resistance to gefitinib. Collectively, these findings suggest that Oct4 plays a pivotal role in the maintenance of lung CSCs resistant to gefitinib in EGFR mutation

  19. Downregulation of gene MDR1 by shRNA to reverse multidrug-resistance of ovarian cancer A2780 cells

    OpenAIRE

    Hongyi Zhang; Jing Wang; Kai Cai; Longwei Jiang; Dandan Zhou; Cuiping Yang,; Junsong Chen,; Dengyu Chen,; Jun Dou

    2012-01-01

    Background: To explore the effects of downregulated multidrug-resistance P-glycoprotein (MDR1/ABCB1) and reversed multidrug-resistance in human A2780 ovarian cancer cells. Materials and Methods: Three shRNAs targeting the MDR1 gene were synthesized, and cloned into plasmid pSUPER-enhanced green fluorescent protein 1 (EGFP1). The formed pSUPER-EGFP1-MDR1-shRNAs were transfected into the A2780 cells, respectively, and the quantitative reverse transcription polymerase chain reaction and west...

  20. Coxsackie-adenovirus receptor as a novel marker of stem cells in treatment-resistant non-small cell lung cancer

    International Nuclear Information System (INIS)

    Background: Treatment resistance resulting from the presence of cancer stem cells (CSCs) remains a challenge in cancer treatment. Little is known about possible markers of CSCs in treatment-resistant non-small cell lung cancer (NSCLC). We explored the coxsackie-adenovirus receptor (CAR) as one such marker of CSCs in models of treatment-resistant NSCLC. Materials and methods: Resistant H460 and A549 cell lines were established by repeated exposure to paclitaxel or fractionated radiation. CSC markers were measured by Western blotting and flow cytometry. We also established stable CAR-overexpressing and stable shRNA-CAR-knockdown cell lines and assessed their survival, invasiveness, and tumorigenic capabilities with clonogenic, telomerase, Matrigel, and tumor formation assays. Results: CAR expression was associated with CSC phenotype both in vitro and in vivo. CAR-overexpressing cells were more treatment-resistant, self-renewing, and tumorigenic than were parental cells, and shRNA-mediated knockdown of CAR expression was sufficient to inhibit these functions. CAR expression also correlated with the epithelial–mesenchymal transition. Conclusions: We showed for the first time that CAR is a marker of CSCs and may affect the activities of CSCs in treatment-resistant NSCLC. CAR may prove to be a target for CSC treatment and a predictor of treatment response in patients with NSCLC.

  1. Microenvironmental Modulation of Decorin and Lumican in Temozolomide-Resistant Glioblastoma and Neuroblastoma Cancer Stem-Like Cells.

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    Cristiano Farace

    Full Text Available The presence of cancer stem cells (CSCs or tumor-initiating cells can lead to cancer recurrence in a permissive cell-microenvironment interplay, promoting invasion in glioblastoma (GBM and neuroblastoma (NB. Extracellular matrix (ECM small leucine-rich proteoglycans (SLRPs play multiple roles in tissue homeostasis by remodeling the extracellular matrix (ECM components and modulating intracellular signaling pathways. Due to their pan-inhibitory properties against receptor tyrosine kinases (RTKs, SLRPs are reported to exert anticancer effects in vitro and in vivo. However, their roles seem to be tissue-specific and they are also involved in cancer cell migration and drug resistance, paving the way to complex different scenarios. The aim of this study was to determine whether the SLRPs decorin (DCN and lumican (LUM are recruited in cell plasticity and microenvironmental adaptation of differentiated cancer cells induced towards stem-like phenotype. Floating neurospheres were generated by applying CSC enrichment medium (neural stem cell serum-free medium, NSC SFM to the established SF-268 and SK-N-SH cancer cell lines, cellular models of GBM and NB, respectively. In both models, the time-dependent synergistic activation of DCN and LUM was observed. The highest DCN and LUM mRNA/protein expression was detected after cell exposure to NSC SFM for 8/12 days, considering these cells as SLRP-expressing (SLRP+ CSC-like. Ultrastructural imaging showed the cellular heterogeneity of both the GBM and NB neurospheres and identified the inner living cells. Parental cell lines of both GBM and NB grew only in soft agar + NSC SFM, whereas the secondary neurospheres (originated from SLRP+ t8 CSC-like showed lower proliferation rates than primary neurospheres. Interestingly, the SLRP+ CSC-like from the GBM and NB neurospheres were resistant to temozolomide (TMZ at concentrations >750 μM. Our results suggest that GBM and NB CSC-like promote the activation of huge

  2. Microenvironmental Modulation of Decorin and Lumican in Temozolomide-Resistant Glioblastoma and Neuroblastoma Cancer Stem-Like Cells.

    Science.gov (United States)

    Farace, Cristiano; Oliver, Jaime Antonio; Melguizo, Consolacion; Alvarez, Pablo; Bandiera, Pasquale; Rama, Ana Rosa; Malaguarnera, Giulia; Ortiz, Raul; Madeddu, Roberto; Prados, Jose

    2015-01-01

    The presence of cancer stem cells (CSCs) or tumor-initiating cells can lead to cancer recurrence in a permissive cell-microenvironment interplay, promoting invasion in glioblastoma (GBM) and neuroblastoma (NB). Extracellular matrix (ECM) small leucine-rich proteoglycans (SLRPs) play multiple roles in tissue homeostasis by remodeling the extracellular matrix (ECM) components and modulating intracellular signaling pathways. Due to their pan-inhibitory properties against receptor tyrosine kinases (RTKs), SLRPs are reported to exert anticancer effects in vitro and in vivo. However, their roles seem to be tissue-specific and they are also involved in cancer cell migration and drug resistance, paving the way to complex different scenarios. The aim of this study was to determine whether the SLRPs decorin (DCN) and lumican (LUM) are recruited in cell plasticity and microenvironmental adaptation of differentiated cancer cells induced towards stem-like phenotype. Floating neurospheres were generated by applying CSC enrichment medium (neural stem cell serum-free medium, NSC SFM) to the established SF-268 and SK-N-SH cancer cell lines, cellular models of GBM and NB, respectively. In both models, the time-dependent synergistic activation of DCN and LUM was observed. The highest DCN and LUM mRNA/protein expression was detected after cell exposure to NSC SFM for 8/12 days, considering these cells as SLRP-expressing (SLRP+) CSC-like. Ultrastructural imaging showed the cellular heterogeneity of both the GBM and NB neurospheres and identified the inner living cells. Parental cell lines of both GBM and NB grew only in soft agar + NSC SFM, whereas the secondary neurospheres (originated from SLRP+ t8 CSC-like) showed lower proliferation rates than primary neurospheres. Interestingly, the SLRP+ CSC-like from the GBM and NB neurospheres were resistant to temozolomide (TMZ) at concentrations >750 μM. Our results suggest that GBM and NB CSC-like promote the activation of huge quantities

  3. Induction of acquired resistance to anti estrogen by reversible mitochondrial DNA depletion in breast cancer cell line

    Science.gov (United States)

    Naito, Akihiro; Carcel-Trullols, Jaime; Xie, Cheng-hui; Evans, Teresa T; Mizumachi, Takatsugu; Higuchi, Masahiro

    2008-01-01

    Although the net benefits of tamoxifen in adjuvant breast cancer therapy have been proven, the recurrence of the cancer in an aggressive and hormone independent form has been highly problematic. We previously demonstrated the important role mitochondrial DNA (mtDNA) plays in hormone-independence in prostate cancer. Here, the role of mtDNA in breast cancer progression was investigated. We established hydroxytamoxifen (4-OHT) resistant HTRMCF by growing MCF-7, a human breast adenocarcinoma cells, in the presence of 4-OHT. HTRMCF was cross-resistant to 4-OHT and ICI182,780 concurrent with the depletion of mtDNA. To further investigate the role of mtDNA depletion, MCF-7 was depleted of mtDNA by treatment with ethidium bromide. MCFρ0 was resistant to both 4-OHT and ICI182,780. Furthermore, cybrid (MCFcyb) prepared by fusion MCFρ0 with platelet to transfer mtDNA showed susceptibility to anti-estrogen. Surprisingly, after withdrawal of 4-OHT for 8 weeks, HTRMCF and their clones became susceptible to both drugs concurrent with a recovery of mtDNA. Herein, our results substantiated the first evidence that the depletion of mtDNA induced by hormone therapy triggers a shift to acquired resistance to hormone therapy in breast cancer. In addition, we showed that mtDNA depletion can be reversed, rendering the cancer cells susceptible to anti-estrogen. The hormone independent phenotype can be reversed should be a step toward more effective treatments for estrogen-responsive breast cancer. PMID:17990320

  4. Role of volume-regulated and calcium-activated anion channels in cell volume homeostasis, cancer and drug resistance

    DEFF Research Database (Denmark)

    Hoffmann, Else Kay; Sørensen, Belinda Halling; Sauter, Daniel Rafael Peter;

    2015-01-01

    Volume-regulated channels for anions (VRAC) / organic osmolytes (VSOAC) play essential roles in cell volume regulation and other cellular functions, e.g. proliferation, cell migration and apoptosis. LRRC8A, which belongs to the leucine rich-repeat containing protein family, was recently shown to be...... an essential component of both VRAC and VSOAC. Reduced VRAC and VSOAC activities are seen in drug resistant cancer cells. ANO1 is a calcium-activated chloride channel expressed on the plasma membrane of e.g. secretory epithelia. ANO1 is amplified and highly expressed in a large number of carcinomas...... important cellular functions as well as their role in cancer and drug resistance....

  5. Targeting glucosylceramide synthase induction of cell surface globotriaosylceramide (Gb3) in acquired cisplatin-resistance of lung cancer and malignant pleural mesothelioma cells

    International Nuclear Information System (INIS)

    Background: Acquired resistance to cisplatin treatment is a caveat when treating patients with non-small cell lung cancer (NSCLC) and malignant pleural mesothelioma (MPM). Ceramide increases in response to chemotherapy, leading to proliferation arrest and apoptosis. However, a tumour stress activation of glucosylceramide synthase (GCS) follows to eliminate ceramide by formation of glycosphingolipids (GSLs) such as globotriaosylceramide (Gb3), the functional receptor of verotoxin-1. Ceramide elimination enhances cell proliferation and apoptosis blockade, thus stimulating tumor progression. GSLs transactivate multidrug resistance 1/P-glycoprotein (MDR1) and multidrug resistance-associated protein 1 (MRP1) expression which further prevents ceramide accumulation and stimulates drug efflux. We investigated the expression of Gb3, MDR1 and MRP1 in NSCLC and MPM cells with acquired cisplatin resistance, and if GCS activity or MDR1 pump inhibitors would reduce their expression and reverse cisplatin-resistance. Methods: Cell surface expression of Gb3, MDR1 and MRP1 and intracellular expression of MDR1 and MRP1 was analyzed by flow cytometry and confocal microscopy on P31 MPM and H1299 NSCLC cells and subline cells with acquired cisplatin resistance. The effect of GCS inhibitor PPMP and MDR1 pump inhibitor cyclosporin A for 72 h on expression and cisplatin cytotoxicity was tested. Results: The cisplatin-resistant cells expressed increased cell surface Gb3. Cell surface Gb3 expression of resistant cells was annihilated by PPMP whereas cyclosporin A decreased Gb3 and MDR1 expression in H1299 cells. No decrease of MDR1 by PPMP was noted in using flow cytometry, whereas a decrease of MDR1 in H1299 and H1299res was indicated with confocal microscopy. No certain co-localization of Gb3 and MDR1 was noted. PPMP, but not cyclosporin A, potentiated cisplatin cytotoxicity in all cells. Conclusions: Cell surface Gb3 expression is a likely tumour biomarker for acquired cisplatin

  6. Targeting glucosylceramide synthase induction of cell surface globotriaosylceramide (Gb3) in acquired cisplatin-resistance of lung cancer and malignant pleural mesothelioma cells

    Energy Technology Data Exchange (ETDEWEB)

    Tyler, Andreas, E-mail: andreas.tyler@medbio.umu.se [Department of Medical Biosciences, Umeå University, S-901 85 Umea (Sweden); Johansson, Anders [Department of Odontology, Umeå University, S-901 85 Umea (Sweden); Karlsson, Terese [Department of Radiation Sciences, Oncology, S-901 85 Umea (Sweden); Gudey, Shyam Kumar; Brännström, Thomas; Grankvist, Kjell; Behnam-Motlagh, Parviz [Department of Medical Biosciences, Umeå University, S-901 85 Umea (Sweden)

    2015-08-01

    Background: Acquired resistance to cisplatin treatment is a caveat when treating patients with non-small cell lung cancer (NSCLC) and malignant pleural mesothelioma (MPM). Ceramide increases in response to chemotherapy, leading to proliferation arrest and apoptosis. However, a tumour stress activation of glucosylceramide synthase (GCS) follows to eliminate ceramide by formation of glycosphingolipids (GSLs) such as globotriaosylceramide (Gb3), the functional receptor of verotoxin-1. Ceramide elimination enhances cell proliferation and apoptosis blockade, thus stimulating tumor progression. GSLs transactivate multidrug resistance 1/P-glycoprotein (MDR1) and multidrug resistance-associated protein 1 (MRP1) expression which further prevents ceramide accumulation and stimulates drug efflux. We investigated the expression of Gb3, MDR1 and MRP1 in NSCLC and MPM cells with acquired cisplatin resistance, and if GCS activity or MDR1 pump inhibitors would reduce their expression and reverse cisplatin-resistance. Methods: Cell surface expression of Gb3, MDR1 and MRP1 and intracellular expression of MDR1 and MRP1 was analyzed by flow cytometry and confocal microscopy on P31 MPM and H1299 NSCLC cells and subline cells with acquired cisplatin resistance. The effect of GCS inhibitor PPMP and MDR1 pump inhibitor cyclosporin A for 72 h on expression and cisplatin cytotoxicity was tested. Results: The cisplatin-resistant cells expressed increased cell surface Gb3. Cell surface Gb3 expression of resistant cells was annihilated by PPMP whereas cyclosporin A decreased Gb3 and MDR1 expression in H1299 cells. No decrease of MDR1 by PPMP was noted in using flow cytometry, whereas a decrease of MDR1 in H1299 and H1299res was indicated with confocal microscopy. No certain co-localization of Gb3 and MDR1 was noted. PPMP, but not cyclosporin A, potentiated cisplatin cytotoxicity in all cells. Conclusions: Cell surface Gb3 expression is a likely tumour biomarker for acquired cisplatin

  7. Imatinib and nilotinib reverse multidrug resistance in cancer cells by inhibiting the efflux activity of the MRP7 (ABCC10.

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    Tong Shen

    Full Text Available BACKGROUND: One of the major mechanisms that could produce resistance to antineoplastic drugs in cancer cells is the ATP binding cassette (ABC transporters. The ABC transporters can significantly decrease the intracellular concentration of antineoplastic drugs by increasing their efflux, thereby lowering the cytotoxic activity of antineoplastic drugs. One of these transporters, the multiple resistant protein 7 (MRP7, ABCC10, has recently been shown to produce resistance to antineoplastic drugs by increasing the efflux of paclitaxel. In this study, we examined the effects of BCR-Abl tyrosine kinase inhibitors imatinib, nilotinib and dasatinib on the activity and expression of MRP7 in HEK293 cells transfected with MRP7, designated HEK-MRP7-2. METHODOLOGY AND/OR PRINCIPAL FINDINGS: We report for the first time that imatinib and nilotinib reversed MRP7-mediated multidrug resistance. Our MTT assay results indicated that MRP7 expression in HEK-MRP7-2 cells was not significantly altered by incubation with 5 microM of imatinib or nilotinib for up to 72 hours. In addition, imatinib and nilotinib (1-5 microM produced a significant concentration-dependent reversal of MRP7-mediated multidrug resistance by enhancing the sensitivity of HEK-MRP7-2 cells to paclitaxel and vincristine. Imatinib and nilotinib, at 5 microM, significantly increased the accumulation of [(3H]-paclitaxel in HEK-MRP7-2 cells. The incubation of the HEK-MRP7-2 cells with imatinib or nilotinib (5 microM also significantly inhibited the efflux of paclitaxel. CONCLUSIONS: Imatinib and nilotinib reverse MRP7-mediated paclitaxel resistance, most likely due to their inhibition of the efflux of paclitaxel via MRP7. These findings suggest that imatinib or nilotinib, in combination with other antineoplastic drugs, may be useful in the treatment of certain resistant cancers.

  8. Nicotine-induced resistance of non-small cell lung cancer to treatment – possible mechanisms

    Directory of Open Access Journals (Sweden)

    Rafał Czyżykowski

    2016-03-01

    Full Text Available Cigarette smoking is the leading risk factor of lung cancer. Data from several clinical studies suggest that continuation of smoking during therapy of tobacco-related cancers is associated with lower response rates to chemotherapy and/or radiotherapy, and even with decreased survival. Although nicotine – an addictive component of tobacco – is not a carcinogen, it may influence cancer development and progression or effectiveness of anti-cancer therapy. Several in vitro and in vivo trials have evaluated the influence of nicotine on lung cancer cells. The best known mechanisms by which nicotine impacts cancer biology involve suppression of apoptosis induced by certain drugs or radiation, promotion of proliferation, angiogenesis, invasion and migration of cancer cells. This effect is mainly mediated by membranous nicotinic acetylcholine receptors whose stimulation leads to sustained activation of such intracellular pathways as PI3K/Akt/mTOR, RAS/RAF/MEK/ERK and JAK/STAT, induction of NF-κB activity, enhanced transcription of mitogenic promoters, inhibition of the mitochondrial death pathway or stimulation of pro-angiogenic factors. We herein summarize the mechanisms underlying nicotine’s influence on biology of lung cancer cells and the effectiveness of anti-cancer therapy.

  9. Stilbenes inhibit androgen receptor expression in 22Rv1 castrate-resistant prostate cancer cells

    Science.gov (United States)

    Androgen receptor (AR) signaling plays an important role in the development and progression of prostate cancer (PCa). Importantly, AR continues to be expressed in advanced stages of castrate-resistant PCa (CRPC), where it can have ligand- independent activity. Identification of naturally occurring s...

  10. Ion channels and transporters in the development of drug resistance in cancer cells

    DEFF Research Database (Denmark)

    Hoffmann, Else Kay; Lambert, Ian Henry

    2014-01-01

    Multi-drug resistance (MDR) to chemotherapy is the major challenge in the treatment of cancer. MDR can develop by numerous mechanisms including decreased drug uptake, increased drug efflux and the failure to undergo drug-induced apoptosis. Evasion of drug-induced apoptosis through modulation of ion...

  11. Changes in subcellular doxorubicin distribution and cellular accumulation alone can largely account for doxorubicin resistance in SW-1573 lung cancer and MCF-7 breast cancer multidrug resistant tumour cells.

    Science.gov (United States)

    Schuurhuis, G. J.; van Heijningen, T. H.; Cervantes, A.; Pinedo, H. M.; de Lange, J. H.; Keizer, H. G.; Broxterman, H. J.; Baak, J. P.; Lankelma, J.

    1993-01-01

    Doxorubicin accumulation defects in multidrug resistant tumour cells are generally small in comparison to the resistance factors. Therefore additional mechanisms must be operative. In this paper we show by a quantitative approach that doxorubicin resistance in several P-glycoprotein-positive non-small cell lung cancer and breast cancer multidrug resistant cell lines can be explained by a summation of accumulation defect and alterations in the efficacy of the drug once present in the cell. This alteration of efficacy was partly due to changes in intracellular drug localisation, characterised by decreased nuclear/cytoplasmic doxorubicin fluorescence ratios (N/C-ratios). N/C-ratios were 2.8-3.6 in sensitive cells, 0.1-0.4 in cells with high (> 70-fold) levels of doxorubicin resistance and 1.2 and 1.9 in cells with low or intermediate (7.5 and 24-fold, respectively) levels of doxorubicin resistance. The change of drug efficacy was reflected by an increase in the total amount of doxorubicin present in the cell at equitoxic (IC50) concentrations. N/C ratios in highly resistant P-glycoprotein-containing cells could be increased with the resistance modifier verapamil to values of 1.3-2.7, a process that was paralleled by a decrease of the cellular doxorubicin amounts present at IC50. At the low to moderate residual levels of resistance, obtained with different concentrations of verapamil, a linear relationship between IC50 and cellular doxorubicin amounts determined at IC50 was found. This shows that at this stage of residual resistance, extra reversal by verapamil should be explained by further increase of drug efficacy rather than by increase of cellular drug accumulation. A similar relationship was found for P-glycoprotein-negative MDR cells with low levels of resistance. Since in these cells N/C ratios could not be altered, verapamil-induced decrease of IC50 must be due to increased drug efficacy by action on as yet unidentified targets. Although the IC50 of sensitive

  12. Astragaloside Ⅳ reduces the expression level of P-glycoprotein in multidrug-resistant human hepatic cancer cell lines.

    Science.gov (United States)

    Wang, Pei-Pei; Xu, Du-Juan; Huang, Can; Wang, Wei-Ping; Xu, Wen-Ke

    2014-06-01

    Astragaloside is a saponin widely used in traditional Chinese medicine and has been reported to be a potent multidrug resistance (MDR) reversal agent. The present study investigated the role of astragaloside Ⅳ (ASIV) in the regulation of P-glycoprotein (P-gp, encoded by the mdr1 gene) and its effect on the reversal of MDR. The activity of ASIV was evaluated using human hepatic cancer cells Bel-7402 and the corresponding 5-fluorouracil (5-FU) resistant cells Bel-7402/FU. ASIV (0.08 mg/ml) potentiated the cytotoxicity of 5-FU which was demonstrated using the MTT assay on Bel-7402/FU cells. ASIV reduced the expression of P-gp as was revealed by immunocytochemistry. Accumulation and efflux studies with the P-gp substrate, rhodamine 123 (Rh123), demonstrated that ASIV inhibited P-gp-mediated drug efflux. Furthermore, it was demonstrated that ASⅣ enhanced the drug accumulation of 5-FU using a high performance liquid chromatography (HPLC) assay for drug resistant cells. Furthermore, ASIV may downregulate the expression of P-gp, which was examined using western blot analysis and polymerase chain reaction. In conclusion, the results of the present study indicated that ASIV reverses the drug resistance of Bel-7402/FU cells by downregulating the expression of mdr1. ASIV may represent a potent modulator of P-gp-mediated MDR in hepatic cancer therapy. PMID:24676670

  13. Intraperitoneal delivery of a novel liposome-encapsulated paclitaxel redirects metabolic reprogramming and effectively inhibits cancer stem cells in Taxol(®)-resistant ovarian cancer.

    Science.gov (United States)

    Shen, Yao-An; Li, Wai-Hou; Chen, Po-Hung; He, Chun-Lin; Chang, Yen-Hou; Chuang, Chi-Mu

    2015-01-01

    Taxol(®) remained as the mainstay therapeutic agent in the treatment of ovarian cancer, however recurrence rate is still high. Cancer stem cells (CSCs) represent a subset of cells in the bulk of tumors and play a central role in inducing drug resistance and recurrence. Furthermore, cancer metabolism has been an area under intensive investigation, since accumulating evidence has shown that CSCs and cancer metabolism are closely linked, an effect named as metabolic reprogramming. In this work, we aimed to investigate the impacts of a novel liposome-encapsulated paclitaxel (Nano-Taxol) on the stemness phenotype and metabolic reprogramming. A paclitaxel-resistant cell line (TR) was established at first. Tumor growth was induced in the mice peritoneal cavity by inoculation of TR cells. A 2x2 factorial experiment was designed to test the therapeutic efficacy in which factor 1 represented the comparison of drugs (Taxol(®) versus Nano-Taxol), while factor 2 represented the delivery route (intravenous versus intraperitoneal delivery). In this work, we found that intraperitoneal delivery of Nano-Taxol redirects metabolic reprogramming, from glycolysis to oxidative phosphorylation, and effectively suppresses cancer stem cells. Also, intraperitoneal delivery of Nano-Taxol led to a significantly better control of tumor growth compared with intravenous delivery of Taxol(®) (current standard treatment). This translational research may serve as a novel pathway for the drug development of nanomedicine. In the future, this treatment modality may be extended to treat several relevant cancers that have been proved to be suitable for the loco-regional delivery of therapeutic agents, including colon cancer, gastric cancer, and pancreatic cancer. PMID:26175846

  14. Stromal Cell-Derived Factor 1α Mediates Resistance to mTOR-Directed Therapy in Pancreatic Cancer

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    Colin D. Weekes

    2012-08-01

    Full Text Available PURPOSE: The factors preventing the translation of preclinical findings supporting the clinical development mTOR-targeted therapy in pancreatic cancer therapy remain undetermined. Stromal cell.derived factor 1α (SDF-1α-CXCR4 signaling was examined as a representative microenvironmental factor able to promote mTOR-targeted therapy resistance in pancreatic cancer. EXPERIMENTAL DESIGN: Primary pancreas explant xenografts and in vitro experiments were used to perform pharmacodynamic analyses of SDF-1α-CXCR4 regulation of the mTOR pathway. Combinatorial effects of CXCR4, EGFR, and mTOR pharmacologic inhibition were evaluated in temsirolimus-resistant and -sensitive xenografts. Intratumoral gene and protein expressions of mTOR pathway effectors cyclin D1, c-Myc, and VEGF were evaluated. RESULTS: Baseline intratumoral SDF-1α gene expression correlated with temsirolimus resistance in explant models. SDF-1α stimulation of pancreatic cells resulted in CXCR4-mediated PI3-kinase-dependent S6-RP phosphorylation (pS6-RP on exposure to temsirolimus. Combinatorial therapy with AMD3465 (CXCR4 small-molecule inhibitor and temsirolimus resulted in effective tumor growth inhibition to overcome temsirolimus resistance. In contrast, SDF-1α exposure induced a temsirolimus-resistant phenotype in temsirolimus-sensitive explants. AMD3465 inhibited CXCR4-mediated intratumoral S6-RP phosphorylation and cyclin D and c-myc gene expression. Next, CXCR4 promoted intratumoral EGFR expression in association with temsirolimus resistance. Treatment with AMD3465, temsirolimus- and erlotinib-mediated tumor growth inhibition to overcome temsirolimus resistance in the explant model. Lastly, SDF-1α-CXCR4 signaling increased intratumoral VEGF gene and protein expression. CONCLUSIONS: SDF-1α-CXCR4 signaling represents a microenvironmental factor that can maintain mTOR pathway fidelity to promote resistance to mTOR-targeted therapy in pancreatic cancer by a variety of mechanisms

  15. Mitogen-activated protein kinase-activated protein kinase 2 mediates resistance to Hydrogen peroxide-induced oxidative stress in Human hepatobiliary Cancer cells

    OpenAIRE

    Nguyen Ho-Bouldoires, Thang Huong; Clapéron, Audrey; Mergey, Martine; Wendum, Dominique; Desbois-Mouthon, Christèle; Tahraoui, Sylvana; Fartoux, Laetitia; Chettouh, Hamza; Merabtene, Fatiha; Scatton, Olivier; Gaestel, Matthias; Praz, Françoise; Housset, Chantal; Fouassier, Laura

    2015-01-01

    The development and progression of liver cancer are characterized by increased levels of reactive oxygen species (ROS). ROS-induced oxidative stress impairs cell proliferation and ultimately leads to cell death. Although liver cancer cells are especially resistant to oxidative stress, mechanisms of such resistance remain understudied. We identified the MAPK-activated protein kinase 2 (MK2)/Heat shock protein 27 (Hsp27) signaling pathway mediating defenses against oxidative stress. Besides to ...

  16. Effects of Withania somnifera and Tinospora cordifolia extracts on the side population phenotype of human epithelial cancer cells: toward targeting multidrug resistance in cancer.

    Science.gov (United States)

    Maliyakkal, Naseer; Appadath Beeran, Asmy; Balaji, Sai A; Udupa, Nayanabhirama; Ranganath Pai, Sreedhara; Rangarajan, Annapoorni

    2015-03-01

    Recent reports suggest the existence of a subpopulation of stem-like cancer cells, termed as cancer stem cells (CSCs), which bear functional and phenotypic resemblance with the adult, tissue-resident stem cells. Side population (SP) assay based on differential efflux of Hoechst 33342 has been effectively used for the isolation of CSCs. The drug resistance properties of SP cells are typically due to the increased expression of ABC transporters leading to drug efflux. Conventionally used chemotherapeutic drugs may often leads to an enrichment of SP, revealing their inability to target the drug-resistant SP and CSCs. Thus, identification of agents that can reduce the SP phenotype is currently in vogue in cancer therapeutics. Withania somnifera (WS) and Tinospora cordifolia (TC) have been used in Ayurveda for treating various diseases, including cancer. In the current study, we have investigated the effects of ethanolic (ET) extracts of WS and TC on the cancer SP phenotype. Interestingly, we found significant decrease in SP on treatment with TC-ET, but not with WS-ET. The SP-inhibitory TC-ET was further fractionated into petroleum ether (TC-PET), dichloromethane (TC-DCM), and n-butyl alcohol (TC-nBT) fractions using bioactivity-guided fractionation. Our data revealed that TC-PET and TC-DCM, but not TC-nBT, significantly inhibited SP in a dose-dependent manner. Furthermore, flow cytometry-based functional assays revealed that TC-PET and TC-DCM significantly inhibited ABC-B1 and ABC-G2 transporters and sensitized cancer cells toward chemotherapeutic drug-mediated cytotoxicity. Thus, the TC-PET and TC-DCM may harbor phytochemicals with the potential to reverse the drug-resistant phenotype, thus improving the efficacy of cancer chemotherapy. PMID:25549922

  17. Radiation response of drug-resistant variants of a human breast cancer cell line: The effect of glutathione depletion

    International Nuclear Information System (INIS)

    Two drug-resistant variants of the human breast cancer cell line MCF-7 have been shown previously to exhibit radiation resistance associated with an increase in the size of the shoulder on the radiation survival curve. In the present study, glutathione (GSH) depletion was achieved by exposure of cells to buthionine sulfoximine (BSO) with, in some cases, additional treatment with dimethyl fumarate. Levels of GSH in the adriamycin-resistant subline MCF-7 ADRR are initially lower than in the other two sublines and are depleted to a greater extent by exposure to BSO. Wild-type MCF-7 cells are not sensitized by GSH depletion when irradiated under aerated conditions but are sensitized under hypoxic conditions to an extent which is related to the level of GSH depletion. In contrast both the drug-resistant sublines (MCF-7 ADRR and the melphalan-resistant line MCF-7 MLNR) are radiosensitized by GSH depletion under both aerated and hypoxic conditions. It is hypothesized that in the case of the MCF-7 ADRR cell line, which expresses high levels of the GSH-associated redox enzyme systems, GSH-S-transferase and GSH-peroxidase (GSH-Px), radiosensitization results when GSH-Px is inhibited in GSH-depleted cells. The reasons for radiosensitization of aerated MCF-7 MLNR cells cannot be explained on this basis, however, and other factors are being examined

  18. Involvement of CUL4A in Regulation of Multidrug Resistance to P-gp Substrate Drugs in Breast Cancer Cells

    Directory of Open Access Journals (Sweden)

    Yunshan Wang

    2013-12-01

    Full Text Available CUL4A encodes a core component of a cullin-based E3 ubiquitin ligase complex that regulates many critical processes such as cell cycle progression, DNA replication, DNA repair and chromatin remodeling by targeting a variety of proteins for ubiquitination and degradation. In the research described in this report we aimed to clarify whether CUL4A participates in multiple drug resistance (MDR in breast cancer cells. We first transfected vectors carrying CUL4A and specific shCUL4A into breast cancer cells and corresponding Adr cells respectively. Using reverse transcription polymerase chain reactions and western blots, we found that overexpression of CUL4A in MCF7 and MDA-MB-468 cells up-regulated MDR1/P-gp expression on both the transcription and protein levels, which conferred multidrug resistance to P-gp substrate drugs, as determined by 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assays. On the other hand, silencing CUL4A in MCF7/Adr and MDA-MB-468/Adr cells led to the opposite effect. Moreover, ERK1/2 in CUL4A-overexpressing cells was highly activated and after treatment with PD98059, an ERK1/2-specific inhibitor, CUL4A-induced expression of MDR1/P-gp was decreased significantly. Lastly, immunohistochemistry in breast cancer tissues showed that P-gp expression had a positive correlation with the expression of CUL4A and ERK1/2. Thus, these results implied that CUL4A and ERK1/2 participated in multi-drug resistance in breast cancer through regulation of MDR1/P-gp expression.

  19. Carbon-ion beam irradiation kills X-ray-resistant p53-null cancer cells by inducing mitotic catastrophe.

    Directory of Open Access Journals (Sweden)

    Napapat Amornwichet

    Full Text Available BACKGROUND AND PURPOSE: To understand the mechanisms involved in the strong killing effect of carbon-ion beam irradiation on cancer cells with TP53 tumor suppressor gene deficiencies. MATERIALS AND METHODS: DNA damage responses after carbon-ion beam or X-ray irradiation in isogenic HCT116 colorectal cancer cell lines with and without TP53 (p53+/+ and p53-/-, respectively were analyzed as follows: cell survival by clonogenic assay, cell death modes by morphologic observation of DAPI-stained nuclei, DNA double-strand breaks (DSBs by immunostaining of phosphorylated H2AX (γH2AX, and cell cycle by flow cytometry and immunostaining of Ser10-phosphorylated histone H3. RESULTS: The p53-/- cells were more resistant than the p53+/+ cells to X-ray irradiation, while the sensitivities of the p53+/+ and p53-/- cells to carbon-ion beam irradiation were comparable. X-ray and carbon-ion beam irradiations predominantly induced apoptosis of the p53+/+ cells but not the p53-/- cells. In the p53-/- cells, carbon-ion beam irradiation, but not X-ray irradiation, markedly induced mitotic catastrophe that was associated with premature mitotic entry with harboring long-retained DSBs at 24 h post-irradiation. CONCLUSIONS: Efficient induction of mitotic catastrophe in apoptosis-resistant p53-deficient cells implies a strong cancer cell-killing effect of carbon-ion beam irradiation that is independent of the p53 status, suggesting its biological advantage over X-ray treatment.

  20. A cell-targeted, size-photocontrollable, nuclear-uptake nanodrug delivery system for drug-resistant cancer therapy.

    Science.gov (United States)

    Qiu, Liping; Chen, Tao; Öçsoy, Ismail; Yasun, Emir; Wu, Cuichen; Zhu, Guizhi; You, Mingxu; Han, Da; Jiang, Jianhui; Yu, Ruqin; Tan, Weihong

    2015-01-14

    The development of multidrug resistance (MDR) has become an increasingly serious problem in cancer therapy. The cell-membrane overexpression of P-glycoprotein (P-gp), which can actively efflux various anticancer drugs from the cell, is a major mechanism of MDR. Nuclear-uptake nanodrug delivery systems, which enable intranuclear release of anticancer drugs, are expected to address this challenge by bypassing P-gp. However, before entering the nucleus, the nanocarrier must pass through the cell membrane, necessitating coordination between intracellular and intranuclear delivery. To accommodate this requirement, we have used DNA self-assembly to develop a nuclear-uptake nanodrug system carried by a cell-targeted near-infrared (NIR)-responsive nanotruck for drug-resistant cancer therapy. Via DNA hybridization, small drug-loaded gold nanoparticles (termed nanodrugs) can self-assemble onto the side face of a silver-gold nanorod (NR, termed nanotruck) whose end faces were modified with a cell type-specific internalizing aptamer. By using this size-photocontrollable nanodrug delivery system, anticancer drugs can be efficiently accumulated in the nuclei to effectively kill the cancer cells. PMID:25479133

  1. Down Regulation of CIAPIN1 Reverses Multidrug Resistance in Human Breast Cancer Cells by Inhibiting MDR1

    Directory of Open Access Journals (Sweden)

    Xuemei Wang

    2012-06-01

    Full Text Available Cytokine-induced apoptosis inhibitor 1 (CIAPIN1, initially named anamorsin, a newly indentified antiapoptotic molecule is a downstream effector of the receptor tyrosine kinase-Ras signaling pathway. Current study has revealed that CIAPIN1 may have wide and important functions, especially due to its close correlations with malignant tumors. However whether or not it is involved in the multi-drug resistance (MDR process of breast cancer has not been elucidated. To explore the effect of CIAPIN1 on MDR, we examined the expression of P-gp and CIAPIN1 by immunohistochemistry and found there was positive correlation between them. Then we successfully interfered with RNA translation by the infection of siRNA of CIAPIN1 into MCF7/ADM breast cancer cell lines through a lentivirus, and the expression of the target gene was significantly inhibited. After RNAi the drug resistance was reduced significantly and the expression of MDR1mRNA and P-gp in MCF7/ADM cell lines showed a significant decrease. Also the expression of P53 protein increased in a statistically significant way (p ≤ 0.01 after RNAi exposure. In addition, flow cytometry analysis reveals that cell cycle and anti-apoptotic enhancing capability of cells changed after RNAi treatment. These results suggested CIAPIN1 may participate in breast cancer MDR by regulating MDR1 and P53 expression, changing cell cycle and enhancing the anti-apoptotic capability of cells.

  2. Sinomenine sensitizes multidrug-resistant colon cancer cells (Caco-2 to doxorubicin by downregulation of MDR-1 expression.

    Directory of Open Access Journals (Sweden)

    Zhen Liu

    Full Text Available Chemoresistance in multidrug-resistant (MDR cells over expressing P-glycoprotein (P-gp encoded by the MDR1 gene, is a major obstacle to successful chemotherapy for colorectal cancer. Previous studies have indicated that sinomenine can enhance the absorption of various P-gp substrates. In the present study, we investigated the effect of sinomenine on the chemoresistance in colon cancer cells and explored the underlying mechanism. We developed multidrug-resistant Caco-2 (MDR-Caco-2 cells by exposure of Caco-2 cells to increasing concentrations of doxorubicin. We identified overexpression of COX-2 and MDR-1 genes as well as activation of the NF-κB signal pathway in MDR-Caco-2 cells. Importantly, we found that sinomenine enhances the sensitivity of MDR-Caco-2 cells towards doxorubicin by downregulating MDR-1 and COX-2 expression through inhibition of the NF-κB signaling pathway. These findings provide a new potential strategy for the reversal of P-gp-mediated anticancer drug resistance.

  3. Breast cancer cells can switch between estrogen receptor alpha and ErbB signaling and combined treatment against both signaling pathways postpones development of resistance

    DEFF Research Database (Denmark)

    Sonne-Hansen, Katrine; Norrie, Ida C; Emdal, Kristina Bennet; Benjaminsen, Rikke Vicki; Frogne, Thomas; Christiansen, Ib J; Kirkegaard, Tove; Lykkesfeldt, Anne E

    2010-01-01

    The majority of breast cancers are estrogen responsive, but upon progression of disease other growth promoting pathways are activated, e.g., the ErbB receptor system. The present study focuses on resistance to the pure estrogen antagonist fulvestrant and strategies to treat resistant cells or eve...... with pan-ErbB inhibition may postpone or even prevent development of treatment resistance....

  4. Generation and characterisation of cisplatin-resistant non-small cell lung cancer cell lines displaying a stem-like signature.

    Directory of Open Access Journals (Sweden)

    Martin P Barr

    Full Text Available INTRODUCTION: Inherent and acquired cisplatin resistance reduces the effectiveness of this agent in the management of non-small cell lung cancer (NSCLC. Understanding the molecular mechanisms underlying this process may result in the development of novel agents to enhance the sensitivity of cisplatin. METHODS: An isogenic model of cisplatin resistance was generated in a panel of NSCLC cell lines (A549, SKMES-1, MOR, H460. Over a period of twelve months, cisplatin resistant (CisR cell lines were derived from original, age-matched parent cells (PT and subsequently characterized. Proliferation (MTT and clonogenic survival assays (crystal violet were carried out between PT and CisR cells. Cellular response to cisplatin-induced apoptosis and cell cycle distribution were examined by FACS analysis. A panel of cancer stem cell and pluripotent markers was examined in addition to the EMT proteins, c-Met and β-catenin. Cisplatin-DNA adduct formation, DNA damage (γH2AX and cellular platinum uptake (ICP-MS was also assessed. RESULTS: Characterisation studies demonstrated a decreased proliferative capacity of lung tumour cells in response to cisplatin, increased resistance to cisplatin-induced cell death, accumulation of resistant cells in the G0/G1 phase of the cell cycle and enhanced clonogenic survival ability. Moreover, resistant cells displayed a putative stem-like signature with increased expression of CD133+/CD44+cells and increased ALDH activity relative to their corresponding parental cells. The stem cell markers, Nanog, Oct-4 and SOX-2, were significantly upregulated as were the EMT markers, c-Met and β-catenin. While resistant sublines demonstrated decreased uptake of cisplatin in response to treatment, reduced cisplatin-GpG DNA adduct formation and significantly decreased γH2AX foci were observed compared to parental cell lines. CONCLUSION: Our results identified cisplatin resistant subpopulations of NSCLC cells with a putative stem

  5. Tyrosine receptor kinase B silencing inhibits anoikis‑resistance and improves anticancer efficiency of sorafenib in human renal cancer cells.

    Science.gov (United States)

    Zhang, Peng; Xing, Zengshu; Li, Xuechao; Song, Yarong; Zhao, Jun; Xiao, Yajun; Xing, Yifei

    2016-04-01

    Renal cell carcinoma (RCC) is the most common solid neoplasm of adult kidney, and the major treatment for metastatic RCC (mRCC) is molecular targeted therapy. Sorafenib, as a multi-targeted tyrosine kinase inhibitor (TKI), has significantly improved clinical outcomes of mRCC patients. However, complete or long-term remissions are rarely achieved due to intolerance to dose-related adverse effects. It is therefore, necessary to explore novel target molecules for treatment or to enhance the therapeutic efficiency of present TKI for mRCC treatment. Anoikis is a specific type of apoptosis that plays a vital physiological role in regulating tissue homoeostasis. Anoikis-resistance is of critical importance for metastasis of various human cancers including mRCC. However, the precise mechanisms on anoikis-resistance in mRCC are still unclear. Tyrosine receptor kinase B (TrkB) belongs to the Trk family of neurotrophin receptors. Previous investigations have implied that activation or overexpression of TrkB promoted proliferation, survival, angiogenesis, anoikis-resistance and metastasis in human cancers. Yet, the correlation between TrkB and anoikis-resistance in mRCC has rarely been reported. The aim of the present study was to explore the impact of TrkB on anoikis-resistance and targeted therapy in mRCC. Our data revealed that anoikis-resistant ACHN cells presented with tolerance to detachment-induced apoptosis, excessive proliferation and aggressive invasion, accompanied by upregulation of TrkB expression in contrast to parental cells. Furthermore, TrkB silencing caused apoptosis, inhibited proliferation, retarded invasion as well as improved anticancer efficiency of sorafenib in anoikis-resistant ACHN cells through inactivation of PI3K/Akt and MEK/ERK pathways. Our data may offer a novel potential therapeutic strategy for mRCC. PMID:26820170

  6. Effects of 5-fluorouracil on biological characteristics and drug resistance mechanisms of liver cancer cell line PLC/RAF/5

    Directory of Open Access Journals (Sweden)

    CHENG Kangwen

    2015-09-01

    Full Text Available ObjectiveTo study the changes in biological characteristics of a liver cancer cell line PLC/RAF/5 after repeated exposure to a chemotherapy drug, 5-fluorouraci (5-FU, and to investigate the relationship between drug-resistant liver cancer cells and liver cancer stem cells. MethodsA low concentration of 5-FU (1 μg/ml was used to treat the human liver cancer cell line PLC/RAF/5 repeatedly to establish the PLC/RAF/5/5-FU cell line. Morphological differences between the two types of cells were observed. The inhibitory effects of different concentrations of 5-FU (0, 0.25, 0.5, 1, 1.5, and 2 μg/ml on the proliferation of the two types of cells were determined using the CCK-8 assay. Apoptosis of the two types of cells after exposure to different concentrations of 5-FU (0.5, 1, and 2 μg/ml for 48 h was analyzed using flow cytometry. The proportions of side population cells in both types of cells were measured using flow cytometry. The colony-forming ability was compared between the two types of cells by the plate colony-forming assay. The expression of Bax, Bcl-2, ABCG2, and FoxM1 proteins in both types of cells was examined by Western blot. Between-group comparison was performed by t test. ResultsThe PLC/RAF/5/5-FU cell line was successfully established using the chemotherapy drug 5-FU. Compared with the PLC/RAF/5 cells, the PLC/RAF/5/5-FU cells had a larger volume, fewer protrusions, a changed shape of a long shuttle, and enhanced refractivity. Moreover, compared with the parent cells, the PLC/RAF/5/5-FU cells had a significantly lower sensitivity to the inhibitory effect of 5-FU on proliferation, a significantly lower proportion of cells at the G0/G1 phase of the cell cycle, significantly higher proportions of cells at the S and G2/M phases, significantly higher resistance to apoptosis, a significantly higher proportion of side population cells, and significantly enhanced proliferation (P<0.05. According to the results of Western blot assay, the

  7. The c-MYC-ABCB5 axis plays a pivotal role in 5-fluorouracil resistance in human colon cancer cells

    OpenAIRE

    Kugimiya, Naruji; Nishimoto, Arata; Hosoyama, Tohru; Ueno, Koji; Enoki, Tadahiko; Li, Tao-Sheng; Hamano, Kimikazu

    2015-01-01

    c-MYC overexpression is frequently observed in various cancers including colon cancer and regulates many biological activities such as aberrant cell proliferation, apoptosis, genomic instability, immortalization and drug resistance. However, the mechanism by which c-MYC confers drug resistance remains to be fully elucidated. In this study, we found that the c-MYC expression level in primary colorectal cancer tissues correlated with the recurrence rate following 5-fluorouracil (5-FU)-based adj...

  8. Radiobiological characteristics of cancer stem cells from esophageal cancer cell lines

    OpenAIRE

    Wang, Jian-Lin; Yu, Jing-Ping; Zhi-qiang SUN; Sun, Su-Ping

    2014-01-01

    AIM: To study the cancer stem cell population in esophageal cancer cell lines KYSE-150 and TE-1 and identify whether the resulting stem-like spheroid cells display cancer stem cells and radiation resistance characteristics.

  9. Drug resistance in rat colon cancer cell lines is associated with minor changes in susceptibility to cytotoxic cells

    NARCIS (Netherlands)

    W. van de Vrie (Wim); S.A.M. van der Heyden (Sylke); E.E.O. Gheuens (Eric); H.H. Bijma (Hilmar); E.A. de Bruijn (Ernst); R.L. Marquet (Richard); A.T. van Oosterom (Allan); A.M.M. Eggermont (Alexander)

    1993-01-01

    textabstractThe development of resistance to anticancer drugs urges the search for different treatment modalities. Several investigators have reported the concomitant development of drug resistance and resistance to natural killer (NK), lymphokine-activated killer (LAK) or monocyte/macrophage cell l

  10. Response of Patient-Derived Non-Small Cell Lung Cancer Xenografts to Classical and Targeted Therapies Is Not Related to Multidrug Resistance Markers

    OpenAIRE

    Jana Rolff; Iduna Fichtner; Johannes Merk; Cornelia Dorn

    2009-01-01

    Tumor cells that are nonsensitive to anticancer drugs frequently have a multidrug resistant (MDR) phenotype. Many studies with cell lines and patient material have been done to investigate the impact of different resistance markers at protein and mRNA level in drug resistance but with contradictory outcome. In the present study, 26 well-characterised patient-derived non-small cell lung cancer xenografts were used. The known chemosensitivity to etoposide, carboplatin, gemcitabine, paclitaxel a...

  11. Anti-estrogen Resistance in Human Breast Tumors Is Driven by JAG1-NOTCH4-Dependent Cancer Stem Cell Activity

    Directory of Open Access Journals (Sweden)

    Bruno M. Simões

    2015-09-01

    Full Text Available Breast cancers (BCs typically express estrogen receptors (ERs but frequently exhibit de novo or acquired resistance to hormonal therapies. Here, we show that short-term treatment with the anti-estrogens tamoxifen or fulvestrant decrease cell proliferation but increase BC stem cell (BCSC activity through JAG1-NOTCH4 receptor activation both in patient-derived samples and xenograft (PDX tumors. In support of this mechanism, we demonstrate that high ALDH1 predicts resistance in women treated with tamoxifen and that a NOTCH4/HES/HEY gene signature predicts for a poor response/prognosis in 2 ER+ patient cohorts. Targeting of NOTCH4 reverses the increase in Notch and BCSC activity induced by anti-estrogens. Importantly, in PDX tumors with acquired tamoxifen resistance, NOTCH4 inhibition reduced BCSC activity. Thus, we establish that BCSC and NOTCH4 activities predict both de novo and acquired tamoxifen resistance and that combining endocrine therapy with targeting JAG1-NOTCH4 overcomes resistance in human breast cancers.

  12. Bone microenvironment-mediated resistance of cancer cells to bisphosphonates and impact on bone osteocytes/stem cells.

    Science.gov (United States)

    Alasmari, Abeer; Lin, Shih-Chun; Dibart, Serge; Salih, Erdjan

    2016-08-01

    Anti-resorptive bisphosphonates (BPs) have been clinically used to prevent cancer-bone metastasis and cancer-induced bone pathologies despite the fact that the phenotypic response of the cancer-bone interactions to BP exposure is "uncharted territory". This study offers unique insights into the interplay between cancer stem cells and osteocytes/osteoblasts and mesenchymal stem cells using a three-dimensional (3D) live cancer-bone interactive model. We provide extraordinary cryptic details of the biological events that occur as a result of alendronate (ALN) treatment using 3D live cancer-bone model systems under specific bone remodeling stages. While cancer cells are susceptible to BP treatment in the absence of bone, they are totally unaffected in the presence of bone. Cancer cells colonize live bone irrespective of whether the bone is committed to bone resorption or formation and hence, cancer-bone metastasis/interactions are though to be "independent of bone remodeling stages". In our 3D live bone model systems, ALN inhibited bone resorption at the osteoclast differentiation level through effects of mineral-bound ALN on osteocytes and osteoblasts. The mineral-bound ALN rendered bone incapable of osteoblast differentiation, while cancer cells colonize the bone with striking morphological adaptations which led to a conclusion that a direct anti-cancer effect of BPs in a "live or in vivo" bone microenvironment is implausible. The above studies were complemented with mass spectrometric analysis of the media from cancer-bone organ cultures in the absence and presence of ALN. The mineral-bound ALN impacts the bone organs by limiting transformation of mesenchymal stem cells to osteoblasts and leads to diminished endosteal cell population and degenerated osteocytes within the mineralized bone matrix. PMID:27155840

  13. Pancreatic adenocarcinoma upregulated factor (PAUF) confers resistance to pancreatic cancer cells against oncolytic parvovirus H-1 infection through IFNA receptor-mediated signaling

    International Nuclear Information System (INIS)

    Pancreatic adenocarcinoma upregulated factor (PAUF), a novel oncogene, plays a crucial role in the development of pancreatic cancer, including its metastasis and proliferation. Therefore, PAUF-expressing pancreatic cancer cells could be important targets for oncolytic virus-mediated treatment. Panc-1 cells expressing PAUF (Panc-PAUF) showed relative resistance to parvovirus H-1 infection compared with Panc-1 cells expressing an empty vector (Panc-Vec). Of interest, expression of type I IFN-α receptor (IFNAR) was higher in Panc-PAUF cells than in Panc-Vec cells. Increased expression of IFNAR in turn increased the activation of Stat1 and Tyk2 in Panc-PAUF cells compared with that in Panc-Vec cells. Suppression of Tyk2 and Stat1, which are important downstream molecules for IFN-α signaling, sensitized pancreatic cancer cells to parvovirus H-1-mediated apoptosis. Further, constitutive suppression of PAUF sensitized Bxpc3 pancreatic cancer cells to parvovirus H-1 infection. Taken together, these results suggested that PAUF conferred resistance to pancreatic cancer cells against oncolytic parvovirus H-1 infection through IFNAR-mediated signaling. - Highlights: • PAUF confers resistance against oncolytic parvovirus H-1 infection. • PAUF enhances the expression of IFNAR in Panc-1 cells. • Increased activation of Tyk2 or Stat1 by PAUF provides resistance to parvovirus H-1-mediated apoptosis. • Constitutive inhibition of PAUF enhances parvovirus H-1-mediated oncolysis of Bxpc3 pancreatic cancer cells

  14. Pancreatic adenocarcinoma upregulated factor (PAUF) confers resistance to pancreatic cancer cells against oncolytic parvovirus H-1 infection through IFNA receptor-mediated signaling

    Energy Technology Data Exchange (ETDEWEB)

    Kaowinn, Sirichat; Cho, Il-Rae; Moon, Jeong; Jun, Seung Won; Kim, Chang Seok [BK21+, Department of Cogno-Mechatronics Engineering, Pusan National University, Busan 609-736 (Korea, Republic of); Kang, Ho Young [Department of Microbiology, Pusan National University, Busan 609-736 (Korea, Republic of); Kim, Manbok [Department of Medical Science, Dankook University College of Medicine, Cheonan 330-714 (Korea, Republic of); Koh, Sang Seok [Department of Biological Sciences, Dong-A University, Busan 604-714 (Korea, Republic of); Chung, Young-Hwa, E-mail: younghc@pusan.ac.kr [BK21+, Department of Cogno-Mechatronics Engineering, Pusan National University, Busan 609-736 (Korea, Republic of)

    2015-04-03

    Pancreatic adenocarcinoma upregulated factor (PAUF), a novel oncogene, plays a crucial role in the development of pancreatic cancer, including its metastasis and proliferation. Therefore, PAUF-expressing pancreatic cancer cells could be important targets for oncolytic virus-mediated treatment. Panc-1 cells expressing PAUF (Panc-PAUF) showed relative resistance to parvovirus H-1 infection compared with Panc-1 cells expressing an empty vector (Panc-Vec). Of interest, expression of type I IFN-α receptor (IFNAR) was higher in Panc-PAUF cells than in Panc-Vec cells. Increased expression of IFNAR in turn increased the activation of Stat1 and Tyk2 in Panc-PAUF cells compared with that in Panc-Vec cells. Suppression of Tyk2 and Stat1, which are important downstream molecules for IFN-α signaling, sensitized pancreatic cancer cells to parvovirus H-1-mediated apoptosis. Further, constitutive suppression of PAUF sensitized Bxpc3 pancreatic cancer cells to parvovirus H-1 infection. Taken together, these results suggested that PAUF conferred resistance to pancreatic cancer cells against oncolytic parvovirus H-1 infection through IFNAR-mediated signaling. - Highlights: • PAUF confers resistance against oncolytic parvovirus H-1 infection. • PAUF enhances the expression of IFNAR in Panc-1 cells. • Increased activation of Tyk2 or Stat1 by PAUF provides resistance to parvovirus H-1-mediated apoptosis. • Constitutive inhibition of PAUF enhances parvovirus H-1-mediated oncolysis of Bxpc3 pancreatic cancer cells.

  15. Molecular characterization of irinotecan (SN-38) resistant human breast cancer cell lines

    DEFF Research Database (Denmark)

    Jandu, Haatisha; Aluzaite, Kristina; Fogh, Louise;

    2016-01-01

    study was to lay the groundwork for development of predictive biomarkers for irinotecan treatment in BC.Methods: We established BC cell lines with acquired or de novo resistance to SN-38, by exposing the human BC cell lines MCF 7 and MDA MB 231 to either stepwise increasing concentrations over 6 months...

  16. DNA Repair Genes ERCC1 and BRCA1 Expression in Non-Small Cell Lung Cancer Chemotherapy Drug Resistance.

    Science.gov (United States)

    Wang, Shuai; Liu, Feng; Zhu, Jingyan; Chen, Peng; Liu, Hongxing; Liu, Qi; Han, Junqing

    2016-01-01

    BACKGROUND Surgery combined with chemotherapy is an important therapy for non-small cell lung cancer (NSCLC). However, chemotherapy drug resistance seriously hinders the curative effect. Studies show that DNA repair genes ERCC1 and BRCA1 are associated with NSCLC chemotherapy, but their expression and mechanism in NSCLC chemotherapy drug-resistant cells has not been elucidated. MATERIAL AND METHODS NSCLC cell line A549 and drug resistance cell line A549/DDP were cultured. Real-time PCR and Western blot analyses were used to detect ERCC1 and BRCA1 mRNA expression. A549/DDP cells were randomly divided into 3 groups: the control group; the siRNA-negative control group (scramble group); and the siRNA ERCC1 and BRCA1siRNA transfection group. Real-time PCR and Western blot analyses were used to determine ERCC1 and BRCA1 mRNA and protein expression. MTT was used to detect cell proliferation activity. Caspase 3 activity was tested by use of a kit. Western blot analysis was performed to detect PI3K, AKT, phosphorylated PI3K, and phosphorylated AKT protein expression. RESULTS ERCC1 and BRCA1 were overexpressed in A549/DDP compared with A549 (PBRCA1 mRNA and protein expression (PBRCA1 expression obviously inhibited cell proliferation and increased caspase 3 activity (PBRCA1 significantly decreased PI3K and AKT phosphorylation levels (PBRCA1 were overexpressed in NSCLC drug-resistant cells, and they regulated lung cancer occurrence and development through the phosphorylating PI3K/AKT signaling pathway. PMID:27289442

  17. Anti-androgen resistance in prostate cancer cells chronically induced by interleukin-1β

    OpenAIRE

    Staverosky, Julia A.; Zhu, Xin-Hua; Ha, Susan; Logan, Susan K.

    2013-01-01

    Chronic inflammation has been linked to cancer initiation and progression in a variety of tissues, yet the impact of acute and chronic inflammatory signaling on androgen receptor function has not been widely studied. In this report, we examine the impact of the inflammation-linked cytokine, interleukin-1β on androgen receptor function in prostate cancer cells. We demonstrate that acute interleukin-1β treatment inhibits the transcription of the androgen receptor gene itself, resulting in the r...

  18. Secondary metabolites inhibiting ABC transporters and reversing resistance of cancer cells and fungi to cytotoxic and antimicrobial agents

    Directory of Open Access Journals (Sweden)

    Michael eWink

    2012-04-01

    Full Text Available Fungal, bacterial and cancer cells can develop resistance against antifungal, antibacterial or anticancer agents. Mechanisms of resistance are complex and often multifactorial. Mechanisms include: 1. Activation of ABC transporters, such as P-gp, which pump out lipophilic compounds that have entered a cell, 2. Activation of cytochrome p450 oxidases which can oxidise lipophilic agents to make them more hydrophilic and accessible for conjugation reaction with glucuronic acid, sulphate or amino acids, and 3. Activation of glutathione transferase, which can conjugate xenobiotics. This review summarises the evidence that secondary metabolites of plants, such as alkaloids, phenolics and terpenoids can interfere with ABC transporters in cancer cells, parasites, bacteria and fungi. Among the active natural products several lipophilic terpenoids ( monoterpenes, diterpenes, triterpenes (including saponins, steroids (including cardiac glycosides and tetraterpenes but also some alkaloids (isoquinoline, protoberberine, quinoline, indole, monoterpene indole, and steroidal alkaloids function probably as competitive inhibitors of P-gp, MRP1 and BCRP in cancer cells, or efflux pumps in bacteria (NorA and fungi. More polar phenolics (phenolic acids, flavonoids, catechins, chalcones, xanthones, stilbenes, anthocyanins, tannins, anthraquinones, and naphthoquinones directly inhibit proteins forming several hydrogen and ionic bonds and thus disturbing the 3D structure of the transporters. The natural products may be interesting in medicine or agriculture as they can enhance the activity of active chemotherapeutics or pesticides or even reverse MDR, at least partially, of adapted and resistant cells. If these secondary metabolites are applied in combination with a cytotoxic or antimicrobial agent, they may reverse resistance in a synergistic fashion.

  19. Integrative analyses of gene expression and DNA methylation profiles in breast cancer cell line models of tamoxifen-resistance indicate a potential role of cells with stem-like properties

    DEFF Research Database (Denmark)

    Lin, Xue; Li, Jian; Yin, Guangliang;

    2013-01-01

    Development of resistance to tamoxifen is an important clinical issue in the treatment of breast cancer. Tamoxifen resistance may be the result of acquisition of epigenetic regulation within breast cancer cells, such as DNA methylation, resulting in changed mRNA expression of genes pivotal...... for estrogen-dependent growth. Alternatively, tamoxifen resistance may be due to selection of pre-existing resistant cells, or a combination of the two mechanisms....

  20. Up-regulation of cyclooxygenase-2-derived prostaglandin E2 in colon cancer cells resistant to 5-fluorouracil

    OpenAIRE

    Choi, Cheol Hee; Lee, Tae Bum; Lee, Yeon Ah; Choi, Suk; Kim, Kyung Jong

    2011-01-01

    Purpose It has been suggested that constitutive up-regulation of cyclooxygenase (COX)-2 is associated with resistance to apoptosis, increased angiogenesis, and increased tumor invasiveness in various cancers including colon cancer. There are many factors involved in the resistance to 5-fluorouracil (5-FU) in colon cancer. However, little is known about the role of COX-2 in acquired resistance to 5-FU in colon cancer. Methods Hence we investigated whether COX-2 contribute to acquired resistanc...

  1. 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

  2. Cancer resistance as an acquired and inheritable trait

    DEFF Research Database (Denmark)

    Koch, Janne; Hau, Jann; Jensen, Henrik Elvang;

    2014-01-01

    AIM: To induce cancer resistance in wild-type mice and detect if the resistance could be inherited to the progeny of the induced resistant mice. Furthermore to investigate the spectrum and immunology of this inherited cancer resistance. MATERIALS AND METHODS: Resistance to with live S180 cancer...... cells in BALB/c mice was induced by immunization with inactivated S180 cancer cells. The immunization was performed by either frozen/thawed or irradiated cancer cells or cell-free ascitic fluid (CFAF). RESULTS: In all instances the induced resistance was demonstrated to be inheritable. The phenotype was...... named HICR (heritable induced cancer resistance) and was defined as primary resistant progeny from mice immunized with frozen/thawed or irradiated S180 cells or CFAF obtained from mice with S180 induced ascites. Notably, this resistance was transferred from both male and female mice to the offspring of...

  3. GX15-070 (obatoclax) induces apoptosis and inhibits cathepsin D and L mediated autophagosomal lysis in antiestrogen resistant breast cancer cells

    OpenAIRE

    Schwartz-Roberts, Jessica L; Shajahan, Ayesha N; Cook, Katherine L.; Wärri, Anni; Abu-Asab, Mones; Clarke, Robert

    2013-01-01

    In estrogen receptor positive (ER+) breast cancer cells, BCL2 overexpression contributes to antiestrogen resistance. Direct targeting of the antiapoptotic BCL2 members with GX15-070 (GX; obatoclax), a BH3-mimetic currently in clinical development, is an attractive strategy to overcome antiestrogen resistance in some breast cancers. Recently, GX has been shown to induce both apoptosis and autophagy, yet the underlying cell death mechanisms have yet to be elucidated. Here we show that GX is mor...

  4. Downregulation of HuR as a new mechanism of doxorubicin resistance in breast cancer cells

    OpenAIRE

    Latorre Elisa; Tebaldi Toma; Viero Gabriella; Spartà Antonino; Quattrone Alessandro; Provenzani Alessandro

    2012-01-01

    Abstract Background HuR, an RNA binding protein involved in the post-transcriptional regulation of a wide spectrum of mRNAs, has been demonstrated to be a determinant of carcinogenesis and tumor aggressiveness in several cancer types. In this study, we investigated the role of HuR in the apoptosis and in the chemoresistance induced by the widely used anticancer drug doxorubicin in human breast cancer cells (MCF-7). Results We showed that HuR acts in the early phase of cell response to doxorub...

  5. Significant activity of ecdysteroids on the resistance to doxorubicin in mammalian cancer cells expressing the human ABCB1 transporter.

    Science.gov (United States)

    Martins, Ana; Tóth, Noémi; Ványolós, Attila; Béni, Zoltán; Zupkó, István; Molnár, József; Báthori, Mária; Hunyadi, Attila

    2012-06-14

    Multidrug resistance (MDR) is a major cause of failure of cancer chemotherapy. Fifty-eight ecdysteroids, herbal analogues of the insect molting hormone and their semisynthetic derivatives, were tested for their activity against L5178 mouse T-cell lymphoma cells (non-MDR) and their subcell line transfected with pHa MDR1/A retrovirus overexpressing the human ABCB1 efflux pump (MDR cell line). The compounds showed very low antiproliferative activities but modulated the efflux of rhodamine 123 mediated by the ABCB1 transporter. Roughly depending on the polarity, mild to strong synergism or antagonism was observed by combining ecdysteroids with doxorubicin, and specific structure-activity relationships were also found. Our results show the effect of ecdysteroids on MDR cancer cells for the first time. Less polar derivatives may serve as valuable leads toward a potent and safe resistance modulator. Biological significance of the resistance-increasing activity of the most abundant phytoecdysteroids including 20-hydroxyecdysone is yet to be clarified. PMID:22578055

  6. Cancer Stem Cells in Pancreatic Cancer

    International Nuclear Information System (INIS)

    Pancreatic cancer is an aggressive malignant solid tumor well-known by early metastasis, local invasion, resistance to standard chemo- and radiotherapy and poor prognosis. Increasing evidence indicates that pancreatic cancer is initiated and propagated by cancer stem cells (CSCs). Here we review the current research results regarding CSCs in pancreatic cancer and discuss the different markers identifying pancreatic CSCs. This review will focus on metastasis, microRNA regulation and anti-CSC therapy in pancreatic cancer

  7. Small cell lung cancer transformation and T790M mutation: complimentary roles in acquired resistance to kinase inhibitors in lung cancer.

    Science.gov (United States)

    Suda, Kenichi; Murakami, Isao; Sakai, Kazuko; Mizuuchi, Hiroshi; Shimizu, Shigeki; Sato, Katsuaki; Tomizawa, Kenji; Tomida, Shuta; Yatabe, Yasushi; Nishio, Kazuto; Mitsudomi, Tetsuya

    2015-01-01

    Lung cancers often harbour a mutation in the epidermal growth factor receptor (EGFR) gene. Because proliferation and survival of lung cancers with EGFR mutation solely depend on aberrant signalling from the mutated EGFR, these tumours often show dramatic responses to EGFR tyrosine kinase inhibitors (TKIs). However, acquiring resistance to these drugs is almost inevitable, thus a better understanding of the underlying resistance mechanisms is critical. Small cell lung cancer (SCLC) transformation is a relatively rare acquired resistance mechanism that has lately attracted considerable attention. In the present study, through an in-depth analysis of multiple EGFR-TKI refractory lesions obtained from an autopsy case, we observed a complementary relationship between SCLC transformation and EGFR T790M secondary mutation (resistance mutation). We also identified analogies and differences in genetic aberration between a TKI-refractory lesion with SCLC transformation and one with EGFR T790M mutation. In particular, target sequencing revealed a TP53 P151S mutation in all pre- and post-treatment lesions. PTEN M264I mutation was identified only in a TKI-refractory lesion with SCLC transformation, while PIK3CA and RB1 mutations were identified only in pre-treatment primary tumour samples. These results provide the groundwork for understanding acquired resistance to EGFR-TKIs via SCLC transformation. PMID:26400668

  8. Dihydroartemisinin potentiates the anticancer effect of cisplatin via mTOR inhibition in cisplatin-resistant ovarian cancer cells: involvement of apoptosis and autophagy

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Xue [Department of Gynecology and Obstetrics, The First Affiliated Hospital of Harbin Medical University, Harbin 150001 (China); Li, Ling [Department of Brain Cognition Computing Lab, University of Kent, Kent CT2 7NZ (United Kingdom); Jiang, Hong; Jiang, Keping; Jin, Ye [Department of Gynecology and Obstetrics, The First Affiliated Hospital of Harbin Medical University, Harbin 150001 (China); Zheng, Jianhua, E-mail: zhengjianhua1115@126.com [Department of Gynecology and Obstetrics, The First Affiliated Hospital of Harbin Medical University, Harbin 150001 (China)

    2014-02-14

    Highlights: • Phosphorylation of mTOR is abnormal activation in SKOV3/DDP ovarian cancer cells. • Downregulation of mTOR by DHA helps to sensitize the SKOV3/DDP cells to chemotherapy. • DHA has the potential of induce autophagy in cancer cells. - Abstract: Dihydroartemisinin (DHA) exhibits anticancer activity in tumor cells but its mechanism of action is unclear. Cisplatin (DDP) is currently the best known chemotherapeutic available for ovarian cancer. However, tumors return de novo with acquired resistance over time. Mammalian target of rapamycin (mTOR) is an important kinase that regulates cell apoptosis and autophagy, and its dysregulation has been observed in chemoresistant human cancers. Here, we show that compared with control ovarian cancer cells (SKOV3), mTOR phosphorylation was abnormally activated in cisplatin-resistant ovarian cancer cells (SKOV3/DDP) following cisplatin monotherapy. Treatment with cisplatin combined with DHA could enhance cisplatin-induced proliferation inhibition in SKOV3/DDP cells. This mechanism is at least partially due to DHA deactivation of mTOR kinase and promotion of apoptosis. Although autophagy was also induced by DHA, the reduced cell death was not found by suppressing autophagic flux by Bafilomycin A1 (BAF). Taken together, we conclude that inhibition of cisplatin-induced mTOR activation is one of the main mechanisms by which DHA dramatically promotes its anticancer effect in cisplatin-resistant ovarian cancer cells.

  9. Dihydroartemisinin potentiates the anticancer effect of cisplatin via mTOR inhibition in cisplatin-resistant ovarian cancer cells: involvement of apoptosis and autophagy

    International Nuclear Information System (INIS)

    Highlights: • Phosphorylation of mTOR is abnormal activation in SKOV3/DDP ovarian cancer cells. • Downregulation of mTOR by DHA helps to sensitize the SKOV3/DDP cells to chemotherapy. • DHA has the potential of induce autophagy in cancer cells. - Abstract: Dihydroartemisinin (DHA) exhibits anticancer activity in tumor cells but its mechanism of action is unclear. Cisplatin (DDP) is currently the best known chemotherapeutic available for ovarian cancer. However, tumors return de novo with acquired resistance over time. Mammalian target of rapamycin (mTOR) is an important kinase that regulates cell apoptosis and autophagy, and its dysregulation has been observed in chemoresistant human cancers. Here, we show that compared with control ovarian cancer cells (SKOV3), mTOR phosphorylation was abnormally activated in cisplatin-resistant ovarian cancer cells (SKOV3/DDP) following cisplatin monotherapy. Treatment with cisplatin combined with DHA could enhance cisplatin-induced proliferation inhibition in SKOV3/DDP cells. This mechanism is at least partially due to DHA deactivation of mTOR kinase and promotion of apoptosis. Although autophagy was also induced by DHA, the reduced cell death was not found by suppressing autophagic flux by Bafilomycin A1 (BAF). Taken together, we conclude that inhibition of cisplatin-induced mTOR activation is one of the main mechanisms by which DHA dramatically promotes its anticancer effect in cisplatin-resistant ovarian cancer cells

  10. ERK phosphorylation is predictive of resistance to IGF-1R inhibition in Small Cell Lung Cancer

    OpenAIRE

    Zinn, Rebekah L.; Gardner, Eric E; Marchionni, Luigi; Murphy, Sara C.; Dobromilskaya, Irina; Hann, Christine L.; Rudin, Charles M.

    2013-01-01

    New therapies are critically needed to improve the outcome for patients with small cell lung cancer (SCLC). IGF-1R inhibition is a potential treatment strategy for SCLC: the IGF-1R pathway is commonly upregulated in SCLC, and has been associated with inhibition of apoptosis and stimulation of proliferation through downstream signaling pathways including PI3K-Akt and MAPK. To evaluate potential determinants of response to IGF-1R inhibition, we assessed the relative sensitivity of 19 SCLC cell ...

  11. High hRFI expression correlates with resistance to Fluoro pyrimidines in human colon cancer cell lines and in xenografts

    International Nuclear Information System (INIS)

    We previously reported that the over-expression of hRFI, a protein preferentially expressed in the digestive tract regions of several cancers, exhibited a tendency to inhibit TNF-α induced apoptosis. In this study, we sought to determine the potential effect of hRFI expression on the sensitivity to 5-fluorouracil (5-FU) and/or other fluoro pyrimidines. For the whole lysates of 8 colon cancer cell lines, we performed Western blotting with anti-hRFI antibody and analyzed the correlations between the expression level of hRFI and the cell lines' sensitivity to 5-FU induced apoptosis. Furthermore, for a tissue micro array consisting of 32 xenograft derived human cancer cell lines, we examined the expression levels of hRFI and survivin by immunohistochemical staining, and analyzed the correlations between the expression of each protein and the sensitivity to several chemotherapeutic agents in the xenografts examined. Both in colon cancer cell lines and in xenografts, the expression level of hRFI was correlated with resistance to 5-FU and its derivatives. This evidence suggests that hRFI may be a marker predicting the response to fluorouracil derived chemotherapeutic agents and that the reduction of the expression level of hRFI might improve the outcome of chemotherapy

  12. Prostate cancer stem-like cells proliferate slowly and resist etoposide-induced cytotoxicity via enhancing DNA damage response

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Judy [Division of Nephrology, Department of Medicine, McMaster University, Juravinski Innovation Tower, Room T3310, St. Joseph' s Hospital, 50 Charlton Ave East, Hamilton, Ontario, Canada L8S 4L8 (Canada); Father Sean O' Sullivan Research Institute, Hamilton, Ontario, Canada L8N 4A6 (Canada); The Hamilton Centre for Kidney Research (HCKR), St. Joseph' s Hamilton Healthcare, Hamilton, Ontario, Canada L8N 4A6 (Canada); Tang, Damu, E-mail: damut@mcmaster.ca [Division of Nephrology, Department of Medicine, McMaster University, Juravinski Innovation Tower, Room T3310, St. Joseph' s Hospital, 50 Charlton Ave East, Hamilton, Ontario, Canada L8S 4L8 (Canada); Father Sean O' Sullivan Research Institute, Hamilton, Ontario, Canada L8N 4A6 (Canada); The Hamilton Centre for Kidney Research (HCKR), St. Joseph' s Hamilton Healthcare, Hamilton, Ontario, Canada L8N 4A6 (Canada)

    2014-10-15

    Despite the development of chemoresistance as a major concern in prostate cancer therapy, the underlying mechanisms remain elusive. In this report, we demonstrate that DU145-derived prostate cancer stem cells (PCSCs) progress slowly with more cells accumulating in the G1 phase in comparison to DU145 non-PCSCs. Consistent with the important role of the AKT pathway in promoting G1 progression, DU145 PCSCs were less sensitive to growth factor-induced activation of AKT in comparison to non-PCSCs. In response to etoposide (one of the most commonly used chemotherapeutic drugs), DU145 PCSCs survived significantly better than non-PCSCs. In addition to etoposide, PCSCs demonstrated increased resistance to docetaxel, a taxane drug that is commonly used to treat castration-resistant prostate cancer. Etoposide produced elevated levels of γH2AX and triggered a robust G2/M arrest along with a coordinated reduction of the G1 population in PCSCs compared to non-PCSCs, suggesting that elevated γH2AX plays a role in the resistance of PCSCs to etoposide-induced cytotoxicity. We have generated xenograft tumors from DU145 PCSCs and non-PCSCs. Consistent with the knowledge that PCSCs produce xenograft tumors with more advanced features, we were able to demonstrate that PCSC-derived xenograft tumors displayed higher levels of γH2AX and p-CHK1 compared to non-PCSC-produced xenograft tumors. Collectively, our research suggests that the elevation of DNA damage response contributes to PCSC-associated resistance to genotoxic reagents. - Highlights: • Increased survival in DU145 PCSCs following etoposide-induced cytotoxicity. • PCSCs exhibit increased sensitivity to etoposide-induced DDR. • Resistance to cytotoxicity may be due to slower proliferation in PCSCs. • Reduced kinetics to growth factor induced activation of AKT in PCSCs.

  13. Prostate cancer stem-like cells proliferate slowly and resist etoposide-induced cytotoxicity via enhancing DNA damage response

    International Nuclear Information System (INIS)

    Despite the development of chemoresistance as a major concern in prostate cancer therapy, the underlying mechanisms remain elusive. In this report, we demonstrate that DU145-derived prostate cancer stem cells (PCSCs) progress slowly with more cells accumulating in the G1 phase in comparison to DU145 non-PCSCs. Consistent with the important role of the AKT pathway in promoting G1 progression, DU145 PCSCs were less sensitive to growth factor-induced activation of AKT in comparison to non-PCSCs. In response to etoposide (one of the most commonly used chemotherapeutic drugs), DU145 PCSCs survived significantly better than non-PCSCs. In addition to etoposide, PCSCs demonstrated increased resistance to docetaxel, a taxane drug that is commonly used to treat castration-resistant prostate cancer. Etoposide produced elevated levels of γH2AX and triggered a robust G2/M arrest along with a coordinated reduction of the G1 population in PCSCs compared to non-PCSCs, suggesting that elevated γH2AX plays a role in the resistance of PCSCs to etoposide-induced cytotoxicity. We have generated xenograft tumors from DU145 PCSCs and non-PCSCs. Consistent with the knowledge that PCSCs produce xenograft tumors with more advanced features, we were able to demonstrate that PCSC-derived xenograft tumors displayed higher levels of γH2AX and p-CHK1 compared to non-PCSC-produced xenograft tumors. Collectively, our research suggests that the elevation of DNA damage response contributes to PCSC-associated resistance to genotoxic reagents. - Highlights: • Increased survival in DU145 PCSCs following etoposide-induced cytotoxicity. • PCSCs exhibit increased sensitivity to etoposide-induced DDR. • Resistance to cytotoxicity may be due to slower proliferation in PCSCs. • Reduced kinetics to growth factor induced activation of AKT in PCSCs

  14. Enhancement of 5-fluorouracil-induced cytotoxicity by leucovorin in 5-fluorouracil-resistant gastric cancer cells with upregulated expression of thymidylate synthase

    OpenAIRE

    Nakamura, Ayako; Nakajima, Go; Okuyama, Ryuji; Kuramochi, Hidekazu; Kondoh, Yurin; Kanemura, Toshinori; Takechi, Teiji; Yamamoto, Masakazu; Hayashi, Kazuhiko

    2013-01-01

    Background Elucidation of the mechanisms by which gastric cancer cells acquire resistance to 5-fluorouracil (5FU) may provide important clues to the development of effective chemotherapy for 5FU-resistant gastric cancer Methods Four 5FU-resistant cell lines (MKN45/5FU, MKN74/5FU, NCI-N87/5FU, and KATOIII/5FU) were established by continuous exposure of the cells to progressively increasing concentrations of 5FU for about 1 year. Then, mRNA expression levels of four genes associated with 5FU me...

  15. CD44hiCD24lo mammosphere-forming cells from primary breast cancer display resistance to multiple chemotherapeutic drugs.

    Science.gov (United States)

    Ji, Ping; Zhang, Yong; Wang, Shu-Jun; Ge, Hai-Liang; Zhao, Guo-Ping; Xu, Ying-Chun; Wang, Ying

    2016-06-01

    It has been widely suggested that mammosphere-forming cells from tumor cell lines or primary tumors represent the population of cancer stem cells (CSCs), which is supposed to lead to the failure of routine chemotherapy and the recurrence of the disease. However, it is still difficult to obtain CSCs from primary breast cancer for further investigation. We performed a modified culture system to generate mammosphere-forming cells derived from freshly isolated human breast cancer samples and the breast cancer cell line MCF-7. Cancer stem cell-like phenotypes such as CD44 and CD24 were measured by flow cytometry while alkaline phosphatase (AP) and mammaglobin (MGB1) expression was evaluated immunohistochemically. The expression levels of Klf4, Nanog, Oct4, Sox2 and mdr1 genes were analyzed by quantitative real‑time PCR. Resistance to chemotherapeutic drugs was detected through the apoptosis assay upon drug treatments together with the detection of drug-resistant gene mdr1. The results revealed that we successfully obtained mammosphere‑forming cells from the primary breast cancer in conditioned medium after 14 days of culture. Mammosphere-forming cells from primary breast cancer displayed a CD44hiCD24lo phenotype as well as positive AP and MGB1 reactivity. Stem cell-related genes such as Klf4, Nanog and Oct4 were detectably expressed in these cells. These cells formed tumor-like structures in the lymph nodes of nude mice, which were morphologically and histologically similar to breast cancer. Compared to the breast cancer cell line MCF-7 or mammosphere-forming cells from MCF-7 cells, the mammosphere-forming cells from the primary breast cancer exhibited resistance to three of four first-line chemotherapeutic drugs investigated through the induction of apoptosis, which was largely associated with the increased expression of drug-resistant gene mdr1 upon drug treatment. In conclusion, mammosphere-forming cells generated from the primary breast cancer exhibit CSC

  16. Glucose metabolism determines resistance of cancer cells to bioenergetic crisis after cytochrome-c release.

    LENUS (Irish Health Repository)

    Huber, Heinrich J

    2011-03-01

    Many anticancer drugs activate caspases via the mitochondrial apoptosis pathway. Activation of this pathway triggers a concomitant bioenergetic crisis caused by the release of cytochrome-c (cyt-c). Cancer cells are able to evade these processes by altering metabolic and caspase activation pathways. In this study, we provide the first integrated system study of mitochondrial bioenergetics and apoptosis signalling and examine the role of mitochondrial cyt-c release in these events. In accordance with single-cell experiments, our model showed that loss of cyt-c decreased mitochondrial respiration by 95% and depolarised mitochondrial membrane potential ΔΨ(m) from -142 to -88 mV, with active caspase-3 potentiating this decrease. ATP synthase was reversed under such conditions, consuming ATP and stabilising ΔΨ(m). However, the direction and level of ATP synthase activity showed significant heterogeneity in individual cancer cells, which the model explained by variations in (i) accessible cyt-c after release and (ii) the cell\\'s glycolytic capacity. Our results provide a quantitative and mechanistic explanation for the protective role of enhanced glucose utilisation for cancer cells to avert the otherwise lethal bioenergetic crisis associated with apoptosis initiation.

  17. Annexin A1 is involved in the acquisition and maintenance of a stem cell-like/aggressive phenotype in prostate cancer cells with acquired resistance to zoledronic acid.

    Science.gov (United States)

    Bizzarro, Valentina; Belvedere, Raffaella; Milone, Maria Rita; Pucci, Biagio; Lombardi, Rita; Bruzzese, Francesca; Popolo, Ada; Parente, Luca; Budillon, Alfredo; Petrella, Antonello

    2015-09-22

    In this study, we have characterized the role of annexin A1 (ANXA1) in the acquisition and maintenance of stem-like/aggressive features in prostate cancer (PCa) cells comparing zoledronic acid (ZA)-resistant DU145R80 with their parental DU145 cells. ANXA1 is over-expressed in DU145R80 cells and its down-regulation abolishes their resistance to ZA. Moreover, ANXA1 induces DU145 and DU145R80 invasiveness acting through formyl peptide receptors (FPRs). Also, ANXA1 knockdown is able to inhibit epithelial to mesenchymal transition (EMT) and to reduce focal adhesion kinase (FAK) and metalloproteases (MMP)-2/9 expression in PCa cells. DU145R80 show a cancer stem cell (CSC)-like signature with a high expression of CSC markers including CD44, CD133, NANOG, Snail, Oct4 and ALDH7A1 and CSC-related genes as STAT3. Interestingly, ANXA1 knockdown induces these cells to revert from a putative prostate CSC to a more differentiated phenotype resembling DU145 PCa cell signature. Similar results are obtained concerning some drug resistance-related genes such as ATP Binding Cassette G2 (ABCG2) and Lung Resistant Protein (LRP). Our study provides new insights on the role of ANXA1 protein in PCa onset and progression. PMID:26312765

  18. Anti-cancer effect of metformin by suppressing signaling pathway of HER2 and HER3 in tamoxifen-resistant breast cancer cells.

    Science.gov (United States)

    Kim, Jinkyoung; Lee, Jiyun; Kim, Chungyeul; Choi, Jinhyuk; Kim, Aeree

    2016-05-01

    Development of new therapeutic strategies is becoming increasingly important to overcome tamoxifen resistance. Recently, much interest has been focused on anti-tumor effects of metformin commonly used to treat type II diabetes. Increased protein expression and signaling of epidermal growth factor receptor (EGFR) family is a possible mechanism involved in tamoxifen resistance. Since HER2/HER3 heterodimers are able to induce strong downstream signaling and activate various biological responses such as cellular proliferation and growth, we investigated the anti-cancer effect of metformin by inhibition of signaling pathway via downregulation of HER2 and HER3 using tamoxifen-resistant MCF-7 (TR MCF-7) cells. Compared to MCF-7 cells, TR MCF-7 cells showed increased expression of EGFR, HER2, and HER3, and metformin inhibited the expression of these proteins in a dose- and time-dependent manner. Metformin inhibited activation of HER2 (Tyr1248)/HER3 (Tyr1289)/Akt (Ser473) as well as cell proliferation and colony formation by estrogenic promotion in MCF-7 and TR MCF-7 cells. Known as a HER3 ligand, heregulin (HRG)-β1-induced phosphorylation of HER2, HER3 and Akt, and protein interaction of HER2/HER3 and colony formation were inhibited by metformin in both cells. Consistent with the results in the two cell lines, we identified that metformin inhibited HER2/HER3/Akt signaling axis activated by HRG-β1 using the HER2 and HER3-overexpressing breast cancer cell line SK-BR-3. Lastly, lapatinib-induced HER3 upregulation was significantly inhibited by treatment of metformin in HER3 siRNA-transfected TR MCF-7 cells. These data suggest that metformin might overcome tamoxifen resistance through the inhibition of expression and signaling of receptor tyrosine kinase HER2 and HER3. PMID:26581908

  19. Trafficking Microenvironmental pHs of Polycationic Gene Vectors in Drug-Sensitive and Multidrug-Resistant MCF7 Breast Cancer Cells

    OpenAIRE

    Kang, Han Chang; Samsonova, Olga; Bae, You Han

    2010-01-01

    While multidrug resistance (MDR) has been a significant issue in cancer chemotherapy, delivery resistance to various anticancer biotherapeutics, including genes, has not been widely recognized as a property of MDR. This study aims to provide a better understanding of the transfection characteristics of drug-sensitive and drug-resistant cells by tracing microenvironmental pHs of two representative polymer vectors: poly(l-lysine) and polyethyleneimine. Drug-sensitive breast MCF7 cells had four-...

  20. Circulating endothelial progenitor cells in castration resistant prostate cancer: a randomized, controlled, biomarker study.

    Directory of Open Access Journals (Sweden)

    Thorsten Fuereder

    Full Text Available BACKGROUND: Endothelial progenitor cells (CEPs and circulating endothelial cells (CECs are potential biomarkers of response to anti-angiogenic treatment regimens. In the current study, we investigated the effect of docetaxel and sunitinib on CEP/CEC kinetics and clinical response in castration resistant prostate cancer (CRPC patients. PATIENTS AND METHODS: Chemonaive patients with CRPC were enrolled in this study to receive either sunitinib (37.5 mg/d, in combination with docetaxel (75 mg/m2 or docetaxel alone. CEP and CEC kinetics were analyzed for every cycle. The primary objective was to compare CEP/CEC pharmacodynamics between both treatment arms. We also investigated if CEC/CEP spikes, induced by MTD docetaxel, are suppressed by sunitinib in patients treated with docetaxel/sunitinib relative to docetaxel monotherapy. RESULTS: A total of 27 patients were enrolled. We observed a significant increase of CEP/CEC (total/viable counts over time within each cycle (coefficients 0.29233, 0.22092 and 0.26089, respectively; p<0.001. However, no differences between the treatment groups, in terms of CEP and CEC kinetics, were detected. In the docetaxel monotherapy arm 4 (30% patients responded to therapy with a 50% PSA decline, while 9 (64% patients showed a PSA decline in the combination group (n.s.. The median PFS in the docetaxel monotherapy group was 3.1 months (2.6-3.6 months, 95% CI and 6.2 months (4.9-7.4 months, 95% CI; p = 0.062 in the combination arm. Sunitinib/docetaxel was reasonably well tolerated and toxicity manageable. CONCLUSION: In summary, no significant differences in CEC and CEP kinetics between the treatment arms were observed, although a highly significant increase of CEPs/CECs within each cycle over time was detected. These results mirror the challenge we have to face when employing anti-angiogenic strategies in CRPC. Additional preclinical research is needed to elucidate the underlying molecular mechanisms. However

  1. PLGA nanoparticles codeliver paclitaxel and Stat3 siRNA to overcome cellular resistance in lung cancer cells

    Directory of Open Access Journals (Sweden)

    Su WP

    2012-08-01

    Full Text Available Wen-Pin Su,1,2 Fong-Yu Cheng,3 Dar-Bin Shieh,3–6 Chen-Sheng Yeh,5–7 Wu-Chou Su1,2,81Graduate Institute of Clinical Medicine, College of Medicine, National Cheng Kung University; 2Department of Internal Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University; 3Institute of Oral Medicine, College of Medicine, National Cheng Kung University; 4Department of Stomatology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University; 5Advanced Optoelectronic Technology Center; 6Center for Frontier Materials and Micro/Nano Science and Technology, and 7Department of Chemistry, National Cheng Kung University; 8Cancer Center, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan.Abstract: Background: Effective cancer chemotherapy remains an important issue in cancer treatment, and signal transducer and activator of transcription-3 (Stat3 activation leads to cellular resistance of anticancer agents. Polymers are ideal vectors to carry both chemotherapeutics and small interfering ribonucleic acid (siRNA to enhance antitumor efficacy. In this paper, poly(lactic-co-glycolic acid (PLGA nanoparticles loaded with paclitaxel and Stat3 siRNA were successfully synthesized, and their applications in cancer cells were investigated.Methods: Firstly, paclitaxel was enclosed by PLGA nanoparticles through solvent evaporation. They were then coated with cationic polyethylenimine polymer (PLGA-PEI-TAX, enabling it to carry Stat3 siRNA on its surface through electrostatic interactions (PLGA-PEI-TAX-S3SI. The size, zeta potential, deliver efficacy, and release profile of the PLGA nanocomplexes were characterized in vitro. The cellular uptake, intracellular nanoparticle trajectory, and subsequent cellular events were evaluated after treatment with various PLGA nanocomplexes in human lung cancer A549 cells and A549-derived paclitaxel-resistant

  2. TRAIL-coated lipid-nanoparticles overcome resistance to soluble recombinant TRAIL in non-small cell lung cancer cells

    Science.gov (United States)

    De Miguel, Diego; Gallego-Lleyda, Ana; María Ayuso, José; Erviti-Ardanaz, Sandra; Pazo-Cid, Roberto; del Agua, Celia; José Fernández, Luis; Ochoa, Ignacio; Anel, Alberto; Martinez-Lostao, Luis

    2016-05-01

    Purpose. Non-small cell lung cancer (NSCLC) is one the types of cancer with higher prevalence and mortality. Apo2-Ligand/TRAIL is a TNF family member able to induce apoptosis in tumor cells but not in normal cells. It has been tested in clinical trials against different types of human cancer including NSCLC. However, results of clinical trials have shown a limited efficacy of TRAIL-based therapies. Recently we have demonstrated that artificial lipid nanoparticles coated with bioactive Apo2L/TRAIL (LUV-TRAIL) greatly improved TRAIL cytotoxic ability being capable of killing chemoresistant hematological cancer cells. In the present work we have extended the study to NSCLC. Methods/patients. LUV-TRAIL-induced cytotoxicity was assessed on different NSCLC cell lines with different sensitivity to soluble TRAIL and on primary human tumor cells from three patients suffering from NSCLC cancer. We also tested LUV-TRAIL-cytotoxic ability in combination with several anti-tumor agents. Results. LUV-TRAIL exhibited a greater cytotoxic effect compared to soluble TRAIL both in A549 cells and primary human NSCLC cells. LUV-TRAIL-induced cell death was dependent on caspase-8 and caspase-3 activation. Moreover, combination of LUV-TRAIL with other anti-tumor agents such as flavopiridol, and SNS-032 clearly enhanced LUV-TRAIL-induced cytotoxicity against NSCLC cancer cells. Conclusion. The novel formulation of TRAIL based on displaying it on the surface of lipid nanoparticles greatly increases its anti-tumor activity and has clinical potential in cancer treatment.

  3. Suppression of the death gene BIK is a critical factor for resistance to tamoxifen in MCF-7 breast cancer cells.

    Science.gov (United States)

    Viedma-Rodriguez, Rubí; Baiza-Gutman, Luis Arturo; García-Carrancá, Alejandro; Moreno-Fierros, Leticia; Salamanca-Gómez, Fabio; Arenas-Aranda, Diego

    2013-12-01

    Apoptosis is controlled by the BCL-2 family of proteins, which can be divided into three different subclasses based on the conservation of BCL-2 homology domains. BIK is a founding member of the BH3-only pro-apoptotic protein family. BIK is predominantly localized in the endoplasmic reticulum (ER) and induces apoptosis through the mitochondrial pathway by mobilizing calcium from the ER to the mitochondria. In this study, we determined that suppression of the death gene Bik promotes resistance to tamoxifen (TAM) in MCF-7 breast cancer cells. We utilized small interfering (siRNA) to specifically knockdown BIK in MCF-7 cells and studied their response to tamoxifen. The levels of cell apoptosis, the potential mitochondrial membrane (∆Ψ(m)), and the activation of total caspases were analyzed. Western blot analysis was used to determine the expression of some BCL-2 family proteins. Flow cytometry studies revealed an increase in apoptosis level in MCF-7 cells and a 2-fold increase in relative BIK messenger RNA (mRNA) expression at a concentration of 6.0 μM of TAM. BIK silencing, with a specific RNAi, blocked TAM-induced apoptosis in 45 ± 6.78% of cells. Moreover, it decreased mitochondrial membrane potential (Ψm) and total caspase activity, and exhibited low expression of pro-apoptotic proteins BAX, BAK, PUMA and a high expression of BCl-2 and MCL-1. The above suggests resistance to TAM, regulating the intrinsic pathway and indicate that BIK comprises an important factor in the process of apoptosis, which may exert an influence the ER pathway, which regulates mitochondrial integrity. Collectively, our results show that BIK is a central component of the programmed cell death of TAM-induced MCF-7 breast cancer cells. The silencing of BIK gene will be useful for future studies to establish the mechanisms of regulation of resistance to TAM. PMID:24100375

  4. Effects of Coptis extract combined with chemotherapeutic agents on ROS production, multidrug resistance, and cell growth in A549 human lung cancer cells

    Directory of Open Access Journals (Sweden)

    He Chengwei

    2012-04-01

    Full Text Available Abstract Background Non–small cell lung cancer is associated with high expression of multidrug resistance (MDR proteins and low production of reactive oxygen species (ROS. Coptis extract (COP, a Chinese medicinal herb, and its major constituent, berberine (BER, have anticancer properties. This study aims to investigate the effects of COP and BER combined with chemotherapeutic agents, including fluorouracil (5-FU, camptothecin (CPT, and paclitaxel (TAX, on cell proliferation, ROS production, and MDR in A549 human non-small cell lung cancer cells. Methods A549 cells were treated with different doses of COP and BER, combined with 5-FU, CPT, and TAX. Cell viability was measured by an XTT (2,3-bis-(2-methoxy-4- nitro-5-sulfophenyl-2 H-tetrazolium-5-carboxanilide assay. Intracellular ROS levels were determined by measuring the oxidative conversion of cell permeable 2′,7′-dichlorofluorescein diacetate to fluorescent dichlorofluorescein. MDR of A549 cells was assessed by rhodamine 123 retention assay. Results Both COP and BER significantly inhibited A549 cell growth in a dose-dependent manner. Combinations of COP or BER with chemotherapeutic agents (5-FU, CPT, and TAX exhibited a stronger inhibitory effect on A549 cell growth. In addition, COP and BER increased ROS production and reduced MDR in A549 cells. Conclusion As potential adjuvants to chemotherapy for non–small cell lung cancer, COP and BER increase ROS production, reduce MDR, and enhance the inhibitory effects of chemotherapeutic agents on A549 cell growth.

  5. [The structure of cellular vaults, their role in the normal cell and in the multidrug resistance of cancer].

    Science.gov (United States)

    Szaflarski, Witold; Nowicki, Michał; Zabel, Maciej

    2011-01-01

    The cellular vaults have been described for the first time in 1986 as ribonucleoprotein complexes composed of three proteins, MVP, TEP1 and vPARP and several vRNA strains. Biochemical and structural studies revealed their ubiquitous existence in the cytoplasm of many eukaryotic cells and their barrel-like structure indicating their engagement in the intracellular transport. Furthermore, the high homology between MVP and LRP which was already known to be involved in multidrug resistance mechanism opened a discussion about the role of vaults in both normal and cancer cells. The histopathology research demonstrated an increased amount of MVP/LRP proteins in the cancer as well as showed translocation possibility between cytoplasm and nuclear envelope, which can be of crucial point in the prevention of nucleus against anticancer drugs. PMID:22235652

  6. Mechanistic studies of Gemcitabine-loaded nanoplatforms in resistant pancreatic cancer cells

    International Nuclear Information System (INIS)

    Pancreatic cancer remains the deadliest of all cancers, with a mortality rate of 91%. Gemcitabine is considered the gold chemotherapeutic standard, but only marginally improves life-span due to its chemical instability and low cell penetrance. A new paradigm to improve Gemcitabine’s therapeutic index is to administer it in nanoparticles, which favour its delivery to cells when under 500 nm in diameter. Although promising, this approach still suffers from major limitations, as the choice of nanovector used as well as its effects on Gemcitabine intracellular trafficking inside pancreatic cancer cells remain unknown. A proper elucidation of these mechanisms would allow for the elaboration of better strategies to engineer more potent Gemcitabine nanotherapeutics against pancreatic cancer. Gemcitabine was encapsulated in two types of commonly used nanovectors, namely poly(lactic-co-glycolic acid) (PLGA) and cholesterol-based liposomes, and their physico-chemical parameters assessed in vitro. Their mechanisms of action in human pancreatic cells were compared with those of the free drug, and with each others, using cytotoxity, apoptosis and ultrastructural analyses. Physico-chemical analyses of both drugs showed high loading efficiencies and sizes of less than 200 nm, as assessed by dynamic light scattering (DLS) and transmission electron microscopy (TEM), with a drug release profile of at least one week. These profiles translated to significant cytotoxicity and apoptosis, as well as distinct intracellular trafficking mechanisms, which were most pronounced in the case of PLGem showing significant mitochondrial, cytosolic and endoplasmic reticulum stresses. Our study demonstrates how the choice of nanovector affects the mechanisms of drug action and is a crucial determinant of Gemcitabine intracellular trafficking and potency in pancreatic cancer settings

  7. Platinum(IV) complex with adamantylamine overcomes intrinsic resistance to cisplatin in ovarian cancer cells

    Czech Academy of Sciences Publication Activity Database

    Horváth, Viktor; Blanářová, Olga; Šindlerová, Lenka; Souček, Karel; Hofmanová, Jiřina; Sova, Petr; Kroutil, Aleš; Fedoročko, P.; Kozubík, Alois

    Bratislava : Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, 2006 - (Boháčová, V.; Breier, A.; Zbyňovská, D.; Zliechovec, J.). s. 296-296 ISBN 80-969532-6-5. [Biochemický zjazd /20./. 12.09.2006-16.09.2006, Piešťany] R&D Projects: GA AV ČR(CZ) 1QS500040507; GA MPO(CZ) PZ-Z2/29 Institutional research plan: CEZ:AV0Z50040507 Keywords : ovarian cancer * cisplatin * resistance Subject RIV: BO - Biophysics

  8. Research Progress on Resistance Mechanisms of Epidermal Growth Factor Receptor 
Tyrosine Kinase Inhibitors in Non-small Cell Lung Cancer

    Directory of Open Access Journals (Sweden)

    Yuan LI

    2012-02-01

    Full Text Available With a greater understanding of tumor biology, novel molecular-targeted strategies that block cancer progression pathways have been evaluated as a new therapeutic approach for treating non-small cell lung cancer (NSCLC. Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs, such as gefitinib and erlotinib, show favorable response to EGFR mutant lung cancer in some populations of NSCLC patients. However, the efficacy of EGFR-TKIs is limited by either primary (de novo or acquired resistance after therapy. This review will focus on recently identified mechanisms of primary and acquired resistance to EGFR TKIs and strategies currently being employed to overcome resistance.

  9. Molecular Mechanisms Contributing to Resistance to Tyrosine Kinase-Targeted Therapy for Non-Small Cell Lung Cancer

    International Nuclear Information System (INIS)

    One of the most important pathways in non-small cell lung cancer (NSCLC) is the epidermal growth factor receptor (EGFR) pathway. This pathway affects several crucial processes in tumor development and progression, including tumor cell proliferation, apoptosis regulation, angiogenesis, and metastatic invasion. Targeting EGFR is currently being intensely explored. We are witnessing the development of a number of potential molecular-inhibiting treatments for application in clinical oncology. In the last decade, the tyrosine kinase (TK) domain of the EGFR was identified in NSCLC patients, and it has responded very well with a dramatic clinical improvement to TK inhibitors such are gefitinib and erlotinib. Unfortunately, there were primary and/or secondary resistance to these treatments, as shown by clinical trials. Subsequent molecular biology studies provided some explanations for the drug resistance phenomenon. The molecular mechanisms of resistance need to be clarified. An in-depth understanding of these targeted-therapy resistance may help us explore new strategies for overcoming or reversing the resistance to these inhibitors for the future of NSCLC treatment

  10. Resistance gene expression determines the in vitro chemosensitivity of non-small cell lung cancer (NSCLC

    Directory of Open Access Journals (Sweden)

    Amer Khalid

    2009-08-01

    Full Text Available Abstract Background NSCLC exhibits considerable heterogeneity in its sensitivity to chemotherapy and similar heterogeneity is noted in vitro in a variety of model systems. This study has tested the hypothesis that the molecular basis of the observed in vitro chemosensitivity of NSCLC lies within the known resistance mechanisms inherent to these patients' tumors. Methods The chemosensitivity of a series of 49 NSCLC tumors was assessed using the ATP-based tumor chemosensitivity assay (ATP-TCA and compared with quantitative expression of resistance genes measured by RT-PCR in a Taqman Array™ following extraction of RNA from formalin-fixed paraffin-embedded (FFPE tissue. Results There was considerable heterogeneity between tumors within the ATP-TCA, and while this showed no direct correlation with individual gene expression, there was strong correlation of multi-gene signatures for many of the single agents and combinations tested. For instance, docetaxel activity showed some dependence on the expression of drug pumps, while cisplatin activity showed some dependence on DNA repair enzyme expression. Activity of both drugs was influenced more strongly still by the expression of anti- and pro-apoptotic genes by the tumor for both docetaxel and cisplatin. The doublet combinations of cisplatin with gemcitabine and cisplatin with docetaxel showed gene expression signatures incorporating resistance mechanisms for both agents. Conclusion Genes predicted to be involved in known mechanisms drug sensitivity and resistance correlate well with in vitro chemosensitivity and may allow the definition of predictive signatures to guide individualized chemotherapy in lung cancer.

  11. N′1,N′3-Dimethyl-N′1,N′3-bis(phenylcarbonothioyl Propanedihydrazide (Elesclomol Selectively Kills Cisplatin Resistant Lung Cancer Cells through Reactive Oxygen Species (ROS

    Directory of Open Access Journals (Sweden)

    Niramol Savaraj

    2009-12-01

    Full Text Available Cisplatin is an important chemotherapeutic agent in lung cancer treatment. The mechanism of drug resistance to cisplatin is complex and historically has been difficult to overcome. We report here that cisplatin resistant lung cancer cell lines possess high basal levels of reactive oxygen species (ROS when compared to normal cells and their parental cell counterparts. These resistant cells also have low thioredoxin (TRX levels which may be one of the contributory factors to high ROS. N′1,N′3-dimethyl-N′1,N'3-bis(phenylcarbonothioyl propanedihydrazide (elesclomol, an agent known to increase ROS is selectively toxic to cisplatin-resistant cells, while sparing normal cells and the parental counterpart. The cytotoxic effect of elesclomol in resistant cells is accompanied by further decreases in TRX and glutathione (GSH antioxidant systems, while opposite results were found in parental cells. The ID50 of elesclomol in cisplatin-resistant cells ranged from 5–10 nM, which is well within clinically achievable ranges. N-Acetylcysteine (NAC, which is known to neutralize ROS, can abolish the cytotoxic effect of elesclomol, suggesting that the cytotoxic effect results from increased ROS. Overall, our data suggest that elesclomol selectively kills cisplatin-resistant tumor cells through increased ROS. This agent may hold potential to overcome cisplatin resistance and should be further explored to treat patients who have failed cisplatin therapy.

  12. An integrative analysis of cellular contexts, miRNAs and mRNAs reveals network clusters associated with antiestrogen-resistant breast cancer cells

    Directory of Open Access Journals (Sweden)

    Nam Seungyoon

    2012-12-01

    Full Text Available Abstract Background A major goal of the field of systems biology is to translate genome-wide profiling data (e.g., mRNAs, miRNAs into interpretable functional networks. However, employing a systems biology approach to better understand the complexities underlying drug resistance phenotypes in cancer continues to represent a significant challenge to the field. Previously, we derived two drug-resistant breast cancer sublines (tamoxifen- and fulvestrant-resistant cell lines from the MCF7 breast cancer cell line and performed genome-wide mRNA and microRNA profiling to identify differential molecular pathways underlying acquired resistance to these important antiestrogens. In the current study, to further define molecular characteristics of acquired antiestrogen resistance we constructed an “integrative network”. We combined joint miRNA-mRNA expression profiles, cancer contexts, miRNA-target mRNA relationships, and miRNA upstream regulators. In particular, to reduce the probability of false positive connections in the network, experimentally validated, rather than prediction-oriented, databases were utilized to obtain connectivity. Also, to improve biological interpretation, cancer contexts were incorporated into the network connectivity. Results Based on the integrative network, we extracted “substructures” (network clusters representing the drug resistant states (tamoxifen- or fulvestrant-resistance cells compared to drug sensitive state (parental MCF7 cells. We identified un-described network clusters that contribute to antiestrogen resistance consisting of miR-146a, -27a, -145, -21, -155, -15a, -125b, and let-7s, in addition to the previously described miR-221/222. Conclusions By integrating miRNA-related network, gene/miRNA expression and text-mining, the current study provides a computational-based systems biology approach for further investigating the molecular mechanism underlying antiestrogen resistance in breast cancer cells. In

  13. CCR9-CCL25 interactions promote cisplatin resistance in breast cancer cell through Akt activation in a PI3K-dependent and FAK-independent fashion

    OpenAIRE

    Lillard James W; Grizzle William E; Johnson Erica L; Singh Rajesh; Johnson-Holiday Crystal; Singh Shailesh

    2011-01-01

    Abstract Background Chemotherapy heavily relies on apoptosis to kill breast cancer (BrCa) cells. Many breast tumors respond to chemotherapy, but cells that survive this initial response gain resistance to subsequent treatments. This leads to aggressive cell variants with an enhanced ability to migrate, invade and survive at secondary sites. Metastasis and chemoresistance are responsible for most cancer-related deaths; hence, therapies designed to minimize both are greatly needed. We have rece...

  14. Natural resistance to ascorbic acid induced oxidative stress is mainly mediated by catalase activity in human cancer cells and catalase-silencing sensitizes to oxidative stress

    OpenAIRE

    Klingelhoeffer Christoph; Kämmerer Ulrike; Koospal Monika; Mühling Bettina; Schneider Manuela; Kapp Michaela; Kübler Alexander; Germer Christoph-Thomas; Otto Christoph

    2012-01-01

    Abstract Background Ascorbic acid demonstrates a cytotoxic effect by generating hydrogen peroxide, a reactive oxygen species (ROS) involved in oxidative cell stress. A panel of eleven human cancer cell lines, glioblastoma and carcinoma, were exposed to serial dilutions of ascorbic acid (5-100 mmol/L). The purpose of this study was to analyse the impact of catalase, an important hydrogen peroxide-detoxifying enzyme, on the resistance of cancer cells to ascorbic acid mediated oxidative stress. ...

  15. Implications of MicroRNAs in the Treatment of Gefitinib-Resistant Non-Small Cell Lung Cancer

    Directory of Open Access Journals (Sweden)

    Thomas K. Sin

    2016-02-01

    Full Text Available Non-small cell lung cancer (NSCLC represents about 85% of the reported cases of lung cancer. Acquired resistance to targeted therapy with epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs, such as gefitinib, is not uncommon. It is thus vital to explore novel strategies to restore sensitivity to gefitinib. Provided that microRNAs (miRNAs negatively regulate their gene targets at the transcriptional level, it is speculated that miRNA mimetics may reduce the expression, activity and signal transduction of EGFR so that sensitization of tumour sites to gefitinib-induced cytotoxicity can be achieved. Indeed, a growing body of evidence has shown that the manipulation of endogenous levels of miRNA not only attenuates the EGFR/PI3K/Akt phosphorylation cascade, but also restores apoptotic cell death in in vitro models of experimentally-induced gefitinib resistance and provoked tumour regression/shrinkage in xenograft models. These data are in concordant with the clinical data showing that the differential expression profiles of miRNA in tumour tissues and blood associate strongly with drug response and overall survival. Furthermore, another line of studies indicate that the chemopreventive effects of a variety of natural compounds may involve miRNAs. The present review aims to discuss the therapeutic capacity of miRNAs in relation to recent discoveries on EGFR-TKI resistance, including chronic drug exposure and mutations.

  16. High expression of sphingosine kinase 1 and S1P receptors in chemotherapy-resistant prostate cancer PC3 cells and their camptothecin-induced up-regulation

    International Nuclear Information System (INIS)

    Although most of pharmacological therapies for cancer utilize the apoptotic machinery of the cells, the available anti-cancer drugs are limited due to the ability of prostate cancer cells to escape from the anti-cancer drug-induced apoptosis. A human prostate cancer cell line PC3 is resistant to camptothecin (CPT). To elucidate the mechanism of this resistance, we have examined the involvement of sphingosine kinase (SPHK) and sphingosine 1-phosphate (S1P) receptor in CPT-resistant PC3 and -sensitive LNCaP cells. PC3 cells exhibited higher activity accompanied with higher expression levels of protein and mRNA of SPHK1, and also elevated expression of S1P receptors, S1P1 and S1P3, as compared with those of LNCaP cells. The knockdown of SPHK1 by small interfering RNA and inhibition of S1P receptor signaling by pertussis toxin in PC3 cells induced significant inhibition of cell growth, suggesting implication of SPHK1 and S1P receptors in cell proliferation in PC3 cells. Furthermore, the treatment of PC3 cells with CPT was found to induce up-regulation of the SPHK1/S1P signaling by induction of both SPHK1 enzyme and S1P1/S1P3 receptors. These findings strongly suggest that high expression and up-regulation of SPHK1 and S1P receptors protect PC3 cells from the apoptosis induced by CPT

  17. Interleukin-22 Is Frequently Expressed in Small- and Large-Cell Lung Cancer and Promotes Growth in Chemotherapy-Resistant Cancer Cells

    OpenAIRE

    Kobold, Sebastian; Völk, Stefanie; Clauditz, Till; Küpper, Natascha Jennifer; Minner, Sarah; Tufman, Amanda; Düwell, Peter; Lindner, Michael; Koch, Ina; Heidegger, Simon; Rothenfußer, Simon; Schnurr, Max; Huber, Rudolf Maria; Wilczak, Waldemar; Endres, Stefan

    2013-01-01

    Introduction: In lung cancer, interleukin-22 (IL-22) expression within primary tissue has been demonstrated, but the frequency and the functional consequence of IL-22 signaling have not been addressed. This study aims at analyzing the cellular effects of IL-22 on lung carcinoma cell lines and the prognostic impact of IL-22 tissue expression in lung cancer patients. Methods: Biological effects of IL-22 signaling were investigated in seven lung cancer cell lines by Western blot, flow cytometry,...

  18. A kinase inhibitor screen identifies Mcl-1 and Aurora kinase A as novel treatment targets in antiestrogen-resistant breast cancer cells

    DEFF Research Database (Denmark)

    Thrane, S; Pedersen, A M; Thomsen, M B H; Kirkegaard, T; Rasmussen, B B; Duun-Henriksen, A K; Lænkholm, A V; Bak, M; Lykkesfeldt, A E; Yde, C W

    2015-01-01

    Antiestrogen resistance is a major problem in breast cancer treatment. Therefore, the search for new therapeutic targets and biomarkers for antiestrogen resistance is crucial. In this study, we performed a kinase inhibitor screen on antiestrogen responsive MCF-7 cells and a panel of MCF-7-derived...

  19. Farnesoid X Receptor inhibits tamoxifen-resistant MCF-7 breast cancer cell growth through down-regulation of HER2 expression

    OpenAIRE

    Giordano, Cinzia; Catalano, Stefania; Panza, Salvatore; Vizza, Donatella; Barone, Ines; Bonofiglio, Daniela; Gelsomino, Luca; Rizza, Pietro; Fuqua, Suzanne A. W; Andò, Sebastiano

    2011-01-01

    Tamoxifen (Tam) treatment is a first-line endocrine therapy for estrogen receptor α (ERα) positive breast cancer patients. Unfortunately, resistance frequently occurs and is often related with overexpression of the membrane tyrosine kinase receptor HER2. This is the rationale behind combined treatments with endocrine therapy and novel inhibitors that reduce HER2 expression and signaling and thus inhibit Tam-resistant breast cancer cell growth. In this study we show that activation of Farnesoi...

  20. The hypoxia-mimetic agent CoCl2 induces chemotherapy resistance in LOVO colorectal cancer cells.

    Science.gov (United States)

    Yang, Guanglei; Xu, Shuqing; Peng, Lintao; Li, Hui; Zhao, Yan; Hu, Yanfang

    2016-03-01

    Hypoxia, which is an important factor that mediates tumor progression and poor treatment response, is particularly associated with tumor chemoresistance. However, the molecular mechanisms underlying hypoxia-induced colorectal cancer chemoresistance remain unclear. The present study aimed to explore the mechanism underlying hypoxia‑induced chemotherapy resistance in LOVO colorectal cancer cells. LOVO cells were cultured in a hypoxic environment simulated by cobalt chloride (CoCl2), which is a chemical inducer of hypoxia‑inducible factor‑1α (HIF‑1α). HIF‑1α is a transcription factor that has an important role in tumor cell adaptation to hypoxia, and controls the expression of several genes. Various CoCl2 concentrations are often used to simulate degrees of hypoxia. In the present study, following treatment with CoCl2, an MTT assay was conducted to determine the growth and drug sensitivity of LOVO cells. Reverse transcription‑polymerase chain reaction and western blotting were used to detect the mRNA and protein expression levels of HIF‑1α and factors associated with chemotherapy resistance, including multidrug resistance protein (MRP) and multidrug resistant 1 (MDR1), which encodes the major transmembrane efflux transporter P‑glycoprotein (P‑gp). In addition, the expression levels of apoptosis‑related proteins, including B‑cell lymphoma 2 (Bcl‑2), Bcl‑2‑associated X protein (Bax) and Bcl‑2‑associated agonist of cell death (Bad) were detected by western blotting. Flow cytometry (FCM) was used to visually observe Adriamycin (ADR) accumulation and retention, thus analyzing intracellular drug transportation in cells under hypoxic and normoxic conditions. CoCl2‑simulated hypoxia was able to inhibit tumor cell proliferation, and upregulate the expression levels of HIF‑1α, MDR1/P‑gp and MRP. In addition, proapoptotic members of the Bcl‑2 protein family, Bax and Bad, were downregulated. The anti‑apoptotic member Bcl‑2

  1. Nelfinavir targets multiple drug resistance mechanisms to increase the efficacy of doxorubicin in MCF-7/Dox breast cancer cells.

    Science.gov (United States)

    Chakravarty, Geetika; Mathur, Aditi; Mallade, Pallavi; Gerlach, Samantha; Willis, Joniece; Datta, Amrita; Srivastav, Sudesh; Abdel-Mageed, Asim B; Mondal, Debasis

    2016-05-01

    Development of multidrug resistance (MDR) remains a significant problem in cancer chemotherapy and underscores the importance of using chemosensitizers. Well known MDR mechanisms include: (i) upregulation of drug-efflux; (ii) increased signaling via AKT; and (iii) decreased apoptosis. Therefore, chemosensitizers should target multiple resistance mechanisms. We investigated the efficacy of nelfinavir (NFV), a clinically approved anti-HIV drug, in increasing doxorubicin (DOX) toxicity in a MDR breast cancer cell line, MCF-7/Dox. As compared to parental MCF-7 cells, the MCF-7/Dox were 15-20 fold more resistant to DOX-induced cytotoxicity at 48 h post-exposure (DOX IC50 = 1.8 μM vs. 32.4 μM). Coexposures to NFV could significantly (p transducers, e.g. Grp78, p-PERK, p-eIF2α, and ATF-4; and endoplasmic reticulum (ER) stress induced death sensors, e.g. CHOP & TRIB-3. Multiple exposures to NFV also abrogated the mitogenic effects of IGF-1. In mice carrying MCF-7/Dox tumor xenografts, intraperitoneal (i.p.) injection of NFV (20 mg/kg/day) and DOX (2 mg/kg/twice/wk) decreased tumor growth more significantly (p < 0.01) than either agent alone. Immunohistochemical (IHC) analysis revealed decreased p-AKT and Ki-67 levels. Thus, NFV overcomes MDR in breast cancer cells and should be tested as an adjunct to chemotherapy. PMID:26844637

  2. Dihydrofolate reductase amplification and sensitization to methotrexate of methotrexate-resistant colon cancer cells

    DEFF Research Database (Denmark)

    Morales Torres, Christina; García, Maria J; Ribas, Maria;

    2009-01-01

    have analyzed the structure and dynamics of dihydrofolate reductase (DHFR) gene amplification in HT29 cells treated with methotrexate (MTX). Analysis of the DHFR gene amplification process shows that the amplicon exhibits a complex structure that is consistently reproduced in independent treatments...... responsive to a second round of treatment if left untreated during a sufficient period of time. [Mol Cancer Ther 2009;8(2):424-32]....

  3. Fractionated irradiation of H69 small-cell lung cancer cells causes stable radiation and drug resistance with increased MRP1, MRP2, and topoisomerase IIα expression

    International Nuclear Information System (INIS)

    Purpose: After standard treatment with chemotherapy and radiotherapy, small-cell lung cancer (SCLC) often develops resistance to both treatments. Our aims were to establish if fractionated radiation treatment alone would induce radiation and drug resistance in the H69 SCLC cell line, and to determine the mechanisms of resistance. Methods and Materials: H69 SCLC cells were treated with fractionated X-rays to an accumulated dose of 37.5 Gy over 8 months to produce the H69/R38 subline. Drug and radiation resistance was determined using the MTT (3,-4,5 dimethylthiazol-2,5 diphenyltetrazolium bromide) cell viability assay. Protein expression was analyzed by Western blot. Results: The H69/R38 subline was resistant to radiation (2.0 ± 0.2-fold, p<0.0001), cisplatin (14 ± 7-fold, p < 0.001), daunorubicin (6 ± 3-fold, p<0.05), and navelbine (1.7 ± 0.15-fold, p<0.02). This was associated with increased expression of the multidrug resistance-associated proteins, MRP1 and MRP2, and topoisomerase IIα and decreased expression of glutathione-S-transferase π (GSTπ) and bcl-2 and decreased cisplatin accumulation. Treatment with 4 Gy of X-rays produced a 66% decrease in MRP2 in the H69 cells with no change in the H69/R38 cells. This treatment also caused a 5-fold increase in topoisomerase IIα in the H69/R38 cells compared with a 1.5-fold increase in the H69 cells. Conclusions: Fractionated radiation alone can lead to the development of stable radiation and drug resistance and an altered response to radiation in SCLC cells

  4. Methotrexate diethyl ester-loaded lipid-core nanocapsules in aqueous solution increased antineoplastic effects in resistant breast cancer cell line

    Science.gov (United States)

    Yurgel, Virginia C; Oliveira, Catiuscia P; Begnini, Karine R; Schultze, Eduarda; Thurow, Helena S; Leon, Priscila MM; Dellagostin, Odir A; Campos, Vinicius F; Beck, Ruy CR; Guterres, Silvia S; Collares, Tiago; Pohlmann, Adriana R; Seixas, Fabiana K

    2014-01-01

    Breast cancer is the most frequent cancer affecting women. Methotrexate (MTX) is an antimetabolic drug that remains important in the treatment of breast cancer. Its efficacy is compromised by resistance in cancer cells that occurs through a variety of mechanisms. This study evaluated apoptotic cell death and cell cycle arrest induced by an MTX derivative (MTX diethyl ester [MTX(OEt)2]) and MTX(OEt)2-loaded lipid-core nanocapsules in two MTX-resistant breast adenocarcinoma cell lines, MCF-7 and MDA-MB-231. The formulations prepared presented adequate granulometric profile. The treatment responses were evaluated through flow cytometry. Relying on the mechanism of resistance, we observed different responses between cell lines. For MCF-7 cells, MTX(OEt)2 solution and MTX(OEt)2-loaded lipid-core nanocapsules presented significantly higher apoptotic rates than untreated cells and cells incubated with unloaded lipid-core nanocapsules. For MDA-MB-231 cells, MTX(OEt)2-loaded lipid-core nanocapsules were significantly more efficient in inducing apoptosis than the solution of the free drug. S-phase cell cycle arrest was induced only by MTX(OEt)2 solution. The drug nanoencapsulation improved apoptosis induction for the cell line that presents MTX resistance by lack of transport receptors. PMID:24741306

  5. EGFR-targeted TRAIL and a Smac mimetic synergize to overcome apoptosis resistance in KRAS mutant colorectal cancer cells.

    Directory of Open Access Journals (Sweden)

    Yvonne Möller

    Full Text Available TRAIL is a death receptor ligand that induces cell death preferentially in tumor cells. Recombinant soluble TRAIL, however, performs poorly as an anti-cancer therapeutic because oligomerization is required for potent biological activity. We previously generated a diabody format of tumor-targeted TRAIL termed Db(αEGFR-scTRAIL, comprising single-stranded TRAIL molecules (scTRAIL and the variable domains of a humanized variant of the EGFR blocking antibody Cetuximab. Here we define the bioactivity of Db(αEGFR-scTRAIL with regard to both EGFR inhibition and TRAIL receptor activation in 3D cultures of Caco-2 colorectal cancer cells, which express wild-type K-Ras. Compared with conventional 2D cultures, Caco-2 cells displayed strongly enhanced sensitivity toward Db(αEGFR-scTRAIL in these 3D cultures. We show that the antibody moiety of Db(αEGFR-scTRAIL not only efficiently competed with ligand-induced EGFR function, but also determined the apoptotic response by specifically directing Db(αEGFR-scTRAIL to EGFR-positive cells. To address how aberrantly activated K-Ras, which leads to Cetuximab resistance, affects Db(αEGFR-scTRAIL sensitivity, we generated stable Caco-2tet cells inducibly expressing oncogenic K-Ras(G12V. In the presence of doxycycline, these cells showed increased resistance to Db(αEGFR-scTRAIL, associated with the elevated expression of the anti-apoptotic proteins cIAP2, Bcl-xL and FlipS. Co-treatment of cells with the Smac mimetic SM83 restored the Db(αEGFR-scTRAIL-induced apoptotic response. Importantly, this synergy between Db(αEGFR-scTRAIL and SM83 also translated to 3D cultures of oncogenic K-Ras expressing HCT-116 and LoVo colorectal cancer cells. Our findings thus support the notion that Db(αEGFR-scTRAIL therapy in combination with apoptosis-sensitizing agents may be promising for the treatment of EGFR-positive colorectal cancers, independently of their KRAS status.

  6. RNAi-mediated knockdown of FANCF suppresses cell proliferation, migration, invasion, and drug resistance potential of breast cancer cells

    Directory of Open Access Journals (Sweden)

    L. Zhao

    2014-01-01

    Full Text Available Fanconi anemia complementation group F protein (FANCF is a key factor, which maintains the function of FA/BRCA, a DNA damage response pathway. However, the functional role of FANCF in breast cancer has not been elucidated. We performed a specific FANCF-shRNA knockdown of endogenous FANCF in vitro. Cell viability was measured with a CCK-8 assay. DNA damage was assessed with an alkaline comet assay. Apoptosis, cell cycle, and drug accumulation were measured by flow cytometry. The expression levels of protein were determined by Western blot using specific antibodies. Based on these results, we used cell migration and invasion assays to demonstrate a crucial role for FANCF in those processes. FANCF shRNA effectively inhibited expression of FANCF. We found that proliferation of FANCF knockdown breast cancer cells (MCF-7 and MDA-MB-435S was significantly inhibited, with cell cycle arrest in the S phase, induction of apoptosis, and DNA fragmentation. Inhibition of FANCF also resulted in decreased cell migration and invasion. In addition, FANCF knockdown enhanced sensitivity to doxorubicin in breast cancer cells. These results suggest that FANCF may be a potential target for molecular, therapeutic intervention in breast cancer.

  7. RNAi-mediated knockdown of FANCF suppresses cell proliferation, migration, invasion, and drug resistance potential of breast cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, L.; Li, N.; Yu, J.K.; Tang, H.T.; Li, Y.L.; He, M.; Yu, Z.J.; Bai, X.F. [Department of Pharmacology, School of Pharmacy, China Medical University, Heping Ward, Shenyang City, Liaoning (China); Zheng, Z.H.; Wang, E.H. [Institute of Pathology and Pathophysiology, China Medical University, Heping Ward, Shenyang City, Liaoning (China); Wei, M.J. [Department of Pharmacology, School of Pharmacy, China Medical University, Heping Ward, Shenyang City, Liaoning (China)

    2013-12-12

    Fanconi anemia complementation group F protein (FANCF) is a key factor, which maintains the function of FA/BRCA, a DNA damage response pathway. However, the functional role of FANCF in breast cancer has not been elucidated. We performed a specific FANCF-shRNA knockdown of endogenous FANCF in vitro. Cell viability was measured with a CCK-8 assay. DNA damage was assessed with an alkaline comet assay. Apoptosis, cell cycle, and drug accumulation were measured by flow cytometry. The expression levels of protein were determined by Western blot using specific antibodies. Based on these results, we used cell migration and invasion assays to demonstrate a crucial role for FANCF in those processes. FANCF shRNA effectively inhibited expression of FANCF. We found that proliferation of FANCF knockdown breast cancer cells (MCF-7 and MDA-MB-435S) was significantly inhibited, with cell cycle arrest in the S phase, induction of apoptosis, and DNA fragmentation. Inhibition of FANCF also resulted in decreased cell migration and invasion. In addition, FANCF knockdown enhanced sensitivity to doxorubicin in breast cancer cells. These results suggest that FANCF may be a potential target for molecular, therapeutic intervention in breast cancer.

  8. RNAi-mediated knockdown of FANCF suppresses cell proliferation, migration, invasion, and drug resistance potential of breast cancer cells

    International Nuclear Information System (INIS)

    Fanconi anemia complementation group F protein (FANCF) is a key factor, which maintains the function of FA/BRCA, a DNA damage response pathway. However, the functional role of FANCF in breast cancer has not been elucidated. We performed a specific FANCF-shRNA knockdown of endogenous FANCF in vitro. Cell viability was measured with a CCK-8 assay. DNA damage was assessed with an alkaline comet assay. Apoptosis, cell cycle, and drug accumulation were measured by flow cytometry. The expression levels of protein were determined by Western blot using specific antibodies. Based on these results, we used cell migration and invasion assays to demonstrate a crucial role for FANCF in those processes. FANCF shRNA effectively inhibited expression of FANCF. We found that proliferation of FANCF knockdown breast cancer cells (MCF-7 and MDA-MB-435S) was significantly inhibited, with cell cycle arrest in the S phase, induction of apoptosis, and DNA fragmentation. Inhibition of FANCF also resulted in decreased cell migration and invasion. In addition, FANCF knockdown enhanced sensitivity to doxorubicin in breast cancer cells. These results suggest that FANCF may be a potential target for molecular, therapeutic intervention in breast cancer

  9. Long-term cultivation of colorectal carcinoma cells with anti-cancer drugs induces drug resistance and telomere elongation: an in vitro study

    Directory of Open Access Journals (Sweden)

    Mochizuki Hidetaka

    2001-08-01

    Full Text Available Abstract Background The role of telomerase activation in the expression and/or maintenance of drug resistance is not clearly understood. Therefore, we investigated the relationships, among the telomerase activity, telomere length and the expression of multidrug resistance genes in colorectal cancer cell lines cultivated with anti-cancer drugs. Methods LoVo and DLD-1 cells were continuously grown in the presence of both CDDP and 5-FU for up to 100 days. Cell proliferation, telomerase activity, telomere length and the expression of multidrug resistance genes were serially monitored as the PDL increased. Results The expression of multidrug resistance genes tended to increase as the PDL increased. However, an abnormal aneuploid clone was not detected as far as the cells were monitored by a DNA histogram analysis. Tumor cells showing resistance to anti-cancer drugs revealed a higher cell proliferation rate. The telomere length gradually increased with a progressive PDL. The telomerase activity reached a maximum level at 15 PDL in LoVo cells and at 27 PDL in DLD-1 cells. An increase in the mRNA expression of the telomerase components, especially in hTERT and in hTR, was observed at the same PDLs. Conclusions These results suggest that a high telomerase activity and an elongation of telomeres both appear to help maintain and/or increase drug resistance in colorectal cancer cells. Cancer cells with long telomeres and a high proliferative activity may thus be able to better survive exposure to anti-cancer drugs. This is presumably due to an increased chromosome stability and a strong expression of both mdr-1 and MRP genes.

  10. Tumor microenvironment and cancer therapy resistance.

    Science.gov (United States)

    Sun, Yu

    2016-09-28

    Innate resistance to various therapeutic interventions is a hallmark of cancer. In recent years, however, acquired resistance has emerged as a daunting challenge to anticancer treatments including chemotherapy, radiation and targeted therapy, which abolishes the efficacy of otherwise successful regimens. Cancer cells gain resistance through a variety of mechanisms in both primary and metastatic sites, involving cell intrinsic and extrinsic factors, but the latter often remains overlooked. Mounting evidence suggests critical roles played by the tumor microenvironment (TME) in multiple aspects of cancer progression particularly therapeutic resistance. The TME decreases drug penetration, confers proliferative and antiapoptotic advantages to surviving cells, facilitates resistance without causing genetic mutations and epigenetic changes, collectively modifying disease modality and distorting clinical indices. Recent studies have set the baseline for future investigation on the intricate relationship between cancer resistance and the TME in pathological backgrounds. This review provides an updated outline of research advances in TME biology and highlights the prospect of targeting the TME as an essential strategy to overcome cancer resistance and improve therapeutic outcomes through precise intervention. In the long run, continued inputs into translational medicine remain highly desired to achieve durable responses in the current era of personalized clinical oncology. PMID:26272180

  11. Rubus coreanus Miquel extract causes apoptosis of doxorubicin-resistant NCI/ADR-RES ovarian cancer cells via JNK phosphorylation.

    Science.gov (United States)

    Kim, Min Kyoung; Choi, Hyeong Sim; Cho, Sung-Gook; Shin, Yong Cheol; Ko, Seong-Gyu

    2016-05-01

    Cancer cells can acquire an anticancer, drug-resistant phenotype following chemotherapy, which is tightly linked to cancer malignancy and patient survival rates. Therefore, the identification of options to treat chemotherapy‑resistant cancer cells is an urgent requirement. Rubus coreanus Miquel (RCM) has long been used as a source of food. In addition, it has been reported that RCM has effective functions against particular diseases, including cancer and inflammation. In the present study, it was demonstrated that RCM extract caused the apoptotic cell death of doxorubicin‑resistant NCI/ADR‑RES ovarian cancer cells by phosphorylating c‑Jun N‑terminal kinase (JNK). The RCM‑mediated reduction of cell viability showed no synergism with doxorubicin. In addition, ellagic acid and quercetin, which are phytochemicals found in RCM, also caused apoptosis of the NCI/ADR‑RES cells. In subsequent investigations of the RCM‑altered signaling pathway, RCM extract, ellagic acid and quercetin were found to commonly induce the phosphorylation of JNK and AKT. Additionally, the inhibition of JNK with SP600125 repressed the apoptotic cell death induced by RCM extract, ellagic acid and quercetin, and the inhibition of JNK appeared to switch apoptosis to necrosis. JNK inhibition also reduced the phosphorylation of AKT, which was induced by RCM extract, ellagic acid and quercetin, suggesting that the phosphorylation of JNK is required for AKT phosphorylation in RCM‑, ellagic acid‑ or quercetin‑induced apoptotic cell death. Therefore, the data obtained in the present study led to the conclusion that RCM caused apoptosis of doxorubicin‑resistant NCI/ADR-RES ovarian cancer cells via JNK phosphorylation, and suggested that RCM may be effective in the treatment of chemotherapy‑resistant cancer cells. PMID:26986492

  12. Alpinetin inhibits lung cancer progression and elevates sensitization drug-resistant lung cancer cells to cis-diammined dichloridoplatium

    OpenAIRE

    Wu L; Yang W.; Zhang SN; Lu JB

    2015-01-01

    Lin Wu, Wei Yang, Su-ning Zhang, Ji-bin Lu Department of Thoracic Surgery, Sheng Jing Hospital of China Medical University, Shenyang, People’s Republic of China Objective: Alpinetin is a novel flavonoid that has demonstrated potent antitumor activity in previous studies. However, the efficacy and mechanism of alpinetin in treating lung cancer have not been determined. Methods: We evaluated the impact of different doses and durations of alpinetin treatment on the cell proliferatio...

  13. The insulin-like growth factor 1 receptor causes acquired resistance to erlotinib in lung cancer cells with the wild-type epidermal growth factor receptor.

    Science.gov (United States)

    Suda, Kenichi; Mizuuchi, Hiroshi; Sato, Katsuaki; Takemoto, Toshiki; Iwasaki, Takuya; Mitsudomi, Tetsuya

    2014-08-15

    Epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) therapy often provides a dramatic response in lung cancer patients with EGFR mutations. In addition, moderate clinical efficacy of the EGFR-TKI, erlotinib, has been shown in lung cancer patients with the wild-type EGFR. Numerous molecular mechanisms that cause acquired resistance to EGFR-TKIs have been identified in lung cancers with the EGFR mutations; however, few have been reported in lung cancers with the wild-type EGFR. We used H358 lung adenocarcinoma cells lacking EGFR mutations that showed modest sensitivity to erlotinib. The H358 cells acquired resistance to erlotinib via chronic exposure to the drug. The H358 erlotinib-resistant (ER) cells do not have a secondary EGFR mutation, neither MET gene amplification nor PTEN downregulation; these have been identified in lung cancers with the EGFR mutations. From comprehensive screening of receptor tyrosine kinase phosphorylation, we observed increased phosphorylation of insulin-like growth factor 1 receptor (IGF1R) in H358ER cells compared with parental H358 cells. H358ER cells responded to combined therapy with erlotinib and NVP-AEW541, an IGF1R-TKI. Our results indicate that IGF1R activation is a molecular mechanism that confers acquired resistance to erlotinib in lung cancers with the wild-type EGFR. PMID:24458568

  14. Cancer Stem Cells in Pancreatic Cancer

    OpenAIRE

    Karl-Walter Jauch; Hendrik Seeliger; Hanno Niess; Qi Bao; Andrea Renner; Yue Zhao; Bruns, Christiane J.

    2010-01-01

    Pancreatic cancer is an aggressive malignant solid tumor well-known by early metastasis, local invasion, resistance to standard chemo- and radiotherapy and poor prognosis. Increasing evidence indicates that pancreatic cancer is initiated and propagated by cancer stem cells (CSCs). Here we review the current research results regarding CSCs in pancreatic cancer and discuss the different markers identifying pancreatic CSCs. This review will focus on metastasis, microRNA regulation and anti-CSC t...

  15. Breast cancer stem cells

    Directory of Open Access Journals (Sweden)

    MatthewJNaylor

    2013-08-01

    Full Text Available Cancer metastasis, resistance to therapies and disease recurrence are significant hurdles to successful treatment of breast cancer. Identifying mechanisms by which cancer spreads, survives treatment regimes and regenerates more aggressive tumours are critical to improving patient survival. Substantial evidence gathered over the last 10 years suggests that breast cancer progression and recurrence is supported by cancer stem cells (CSCs. Understanding how CSCs form and how they contribute to the pathology of breast cancer will greatly aid the pursuit of novel therapies targeted at eliminating these cells. This review will summarise what is currently known about the origins of breast CSCs, their role in disease progression and ways in which they may be targeted therapeutically.

  16. Spontaneous T-cell responses against peptides derived from the Taxol resistance-associated gene-3 (TRAG-3) protein in cancer patients

    DEFF Research Database (Denmark)

    Meier, Anders; Hadrup, Sine Reker; Svane, Inge Marie;

    2005-01-01

    Expression of the cancer-testis antigen Taxol resistance - associated gene-3 (TRAG-3) protein is associated with acquired paclitaxel ( Taxol) resistance, and is expressed in various cancer types; e. g., breast cancer, leukemia, and melanoma. Thus, TRAG-3 represents an attractive target for...... immunotherapy of cancer. To identify HLA-A* 02.01 - restricted epitopes from TRAG-3, we screened cancer patients for spontaneous cytotoxic T-cell responses against TRAG-3 - derived peptides. The TRAG-3 protein sequence was screened for 9mer and 10mer peptides possessing HLA-A* 02.01 - binding motifs. Of 12...... potential binders, 9 peptides were indeed capable of binding to the HLA-A* 02.01 molecule, with binding affinities ranging from strong to weak binders. Subsequently, lymphocytes from cancer patients ( 9 breast cancer patients, 12 melanoma patients, and 13 patients with hematopoietic malignancies) were...

  17. The Mechanism of Gefitinib Resistance Induced by Hepatocyte Growth Factor 
in Sensitive Non-small Cell Lung Cancer Cells in Vitro

    Directory of Open Access Journals (Sweden)

    Xianglan XUAN

    2013-01-01

    Full Text Available Background and objective Previous studies have reported that Met might be related to gefitinib resistance in non-small cell lung cancer (NSCLC. The present study aims to explore the mechanism of hepatocyte growth factor (HGF-induced gefitinib resistance in different gene types of sensitive NSCLC in vitro. Methods The PC-9 and H292 cell lines were chosen and induced by HGF. The cell survival was measured using MTT assay, the cell cycle distribution was measured using PI assay, and cell apoptosis with an Annexin V-PE assay, respectively. The c-Met and p-Met protein expression was determined via Western blot analysis. Results Gefitinib inhibited the growth of PC-9 and H292 cells in a dose-dependent manner. The concentration-survival curves of both cell lines shifted to the right when induced with HGF. HGF did not affect PC-9 and H292 cell proliferation. The cell also had a higher cell survival rate when treated with HGF and gefitinib compared with that under gefitinib alone (P<0.05. The apoptotic rate and cell cycle progression showed no significant difference between the HG and G group (P>0.05. HGF stimulated Met phosphorylation in the PC-9 and H292 cells. Gefitinib inhibited the HGF-induced Met phosphorylation in PC-9 cells, but not in H292 cells. Conclusion HGF induces gefitinib resistance in PC-9 and H292 cells. HGF-induced Met phosphorylation may be an important mechanism of gefitinib resistance in sensitive NSCLC.

  18. SRC drives growth of antiestrogen resistant breast cancer cell lines and is a marker for reduced benefit of tamoxifen treatment

    DEFF Research Database (Denmark)

    Larsen, Sarah L; Laenkholm, Anne-Vibeke; Duun-Henriksen, Anne Katrine;

    2015-01-01

    The underlying mechanisms leading to antiestrogen resistance in estrogen-receptor α (ER)-positive breast cancer is still poorly understood. The aim of this study was therefore to identify biomarkers and novel treatments for antiestrogen resistant breast cancer. We performed a kinase inhibitor scr...

  19. miR-222 confers the resistance of breast cancer cells to Adriamycin through suppression of p27(kip1) expression.

    Science.gov (United States)

    Wang, Dan-Dan; Li, Jian; Sha, Huan-Huan; Chen, Xiu; Yang, Su-Jin; Shen, Hong-Yu; Zhong, Shan-Liang; Zhao, Jian-Hua; Tang, Jin-Hai

    2016-09-15

    Adriamycin (Adr) is a potent chemotherapeutic agent for chemotherapy of breast cancer patients. Despite impressive initial clinical responses, some developed drug resistance to Adr-based therapy and the mechanisms underlying breast cancer cells resistance to Adr are not well known. In our previous study, in vitro, we verified that miR-222 was upregulated in Adr-resistant breast cancer cells (MCF-7/Adr) compared with the sensitive parental cells (MCF-7/S). Here, miR-222 inhibitors or mimics were transfected into MCF-7 cell lines. RT-qPCR and western blot were used to detect the expression of p27(kip1). Immunofluorescence showed that miR-222 altered the subcellular location of p27(kip1) in nucleus. MTT was employed to verify the sensitivity of breast cancer cell lines to Adr. Flow cytometry showed the apoptosis and cell cycles of the cells after adding Adr. The results showed that downregulation of miR-222 in MCF-7/Adr increased sensitivity to Adr and Adr-induced apoptosis, and arrested the cells in G1 phase, accompanied by more expressions of p27(kip1), especially in nucleus. Furthermore, overexpressed miR-222 in MCF-7/S had the inverse results. Taken together, the results found that miR-222 induced Adr-resistance at least in part via suppressing p27(kip1) expression and altering its subcellular localization, and miR-222 inhibitors could reverse Adr-resistance of breast cancer cells. These results disclosed that the future holds much promise for the targeted therapeutic in the treatment of Adr-resistant breast cancer. PMID:27282281

  20. Mechanism of c-Met and EGFR tyrosine kinase inhibitor resistance through epithelial mesenchymal transition in non-small cell lung cancer.

    Science.gov (United States)

    Rastogi, Ichwaku; Rajanna, Supriya; Webb, Andrew; Chhabra, Gagan; Foster, Brad; Webb, Brian; Puri, Neelu

    2016-09-01

    According to currently available estimates from Cancer Research UK, 14.1 million new lung cancer cases were diagnosed and a staggering 8.2 million people worldwide died from lung cancer in 2012. EGFR and c-Met are two tyrosine kinase receptors most commonly overexpressed or mutated in Non-small Cell Lung Cancer (NSCLC) resulting in increased proliferation and survival of lung cancer cells. Tyrosine kinase inhibitors (TKIs), such as erlotinib, approved by the FDA as first/second line therapy for NSCLC patients have limited clinical efficacy due to acquired resistance. In this manuscript, we investigate and discuss the role of epithelial mesenchymal transition (EMT) in the development of resistance against EGFR and c-Met TKIs in NSCLC. Our findings show that Zeb-1, a transcriptional repressor of E-Cadherin, is upregulated in TKI-resistant cells causing EMT. We observed that TKI-resistant cells have increased gene and protein expression of EMT related proteins such as Vimentin, N-Cadherin, β-Catenin and Zeb-1, while expression of E-Cadherin, an important cell adhesion molecule, was suppressed. We also confirmed that TKI-resistant cells display mesenchymal cell type morphology, and have upregulation of β-Catenin which may regulate expression of Zeb-1, a transcriptional repressor of E-Cadherin in TKI-resistant NSCLC cells. Finally, we show that down-regulating Zeb-1 by inducing miR-200a or β-Catenin siRNA can increase drug sensitivity of TKI-resistant cells. PMID:27396618

  1. Activation of ErbB3, EGFR and Erk is essential for growth of human breast cancer cell lines with acquired resistance to fulvestrant

    DEFF Research Database (Denmark)

    Frogne, Thomas; Benjaminsen, Rikke V; Sonne-Hansen, Katrine; Sorensen, Boe S; Nexo, Ebba; Laenkholm, Anne-Vibeke; Rasmussen, Louise M; Riese, David J; de Cremoux, Patricia; Stenvang, Jan; Lykkesfeldt, Anne

    2008-01-01

    Seven fulvestrant resistant cell lines derived from the estrogen receptor alpha positive MCF-7 human breast cancer cell line were used to investigate the importance of epidermal growth factor receptor (ErbB1-4) signaling. We found an increase in mRNA expression of EGFR and the ErbB3/ErbB4 ligand...... growth inhibition of two resistant cell lines. These data indicate that ligand activated ErbB3 and EGFR, and Erk signaling play important roles in fulvestrant resistant cell growth. Furthermore, the decreased level of ErbB4 in resistant cells may facilitate heterodimerization of ErbB3 with EGFR and ErbB2....... Our data support that a concerted action against EGFR, ErbB2 and ErbB3 may be required to obtain complete growth suppression of fulvestrant resistant cells....

  2. Omega 3 fatty acids chemosensitize multidrug resistant colon cancer cells by down-regulating cholesterol synthesis and altering detergent resistant membranes composition

    OpenAIRE

    Gelsomino, Giada; Corsetto, Paola A.; Campia, Ivana; Montorfano, Gigliola; Kopecka, Joanna; Castella, Barbara; Gazzano, Elena; Ghigo, Dario; Rizzo, Angela M; Riganti, Chiara

    2013-01-01

    Background The activity of P-glycoprotein (Pgp) and multidrug resistance related protein 1 (MRP1), two membrane transporters involved in multidrug resistance of colon cancer, is increased by high amounts of cholesterol in plasma membrane and detergent resistant membranes (DRMs). It has never been investigated whether omega 3 polyunsatured fatty acids (PUFAs), which modulate cholesterol homeostasis in dyslipidemic syndromes and have chemopreventive effects in colon cancer, may affect the respo...

  3. Prognostic importance of cell-free DNA in chemotherapy resistant ovarian cancer treated with bevacizumab

    DEFF Research Database (Denmark)

    Steffensen, Karina Dahl; Madsen, Christine Vestergaard; Andersen, Rikke Fredslund;

    2014-01-01

    AIM: Treatment of multiresistant epithelial ovarian cancer (EOC) is palliative and patients who have become resistant after multiple lines of chemotherapy often have an unmet need for further and less toxic treatment. Anti-angiogenic therapy has attracted considerable attention in the treatment of...... EOC in combination with chemotherapy. However, only a minor subgroup will benefit from the treatment and there is an obvious need for new markers to select such patients. The purpose of this study was to investigate the effect of single-agent bevacizumab in multiresistant EOC and the importance of......). RESULTS: Eighteen percent responded to treatment according to CA125 and 5.6% had partial response by Response Evaluation Criteria in Solid Tumours (RECIST). Stable disease was seen in 53.5% and 48.6% of the patients by CA125 and RECIST, respectively. Median progression free survival (PFS) and overall...

  4. Targeting AMP-activated protein kinase in adipocytes to modulate obesity-related adipokine production associated with insulin resistance and breast cancer cell proliferation

    Directory of Open Access Journals (Sweden)

    Grisouard Jean

    2011-07-01

    Full Text Available Abstract Background Adipokines, e.g. TNFα, IL-6 and leptin increase insulin resistance, and consequent hyperinsulinaemia influences breast cancer progression. Beside its mitogenic effects, insulin may influence adipokine production from adipocyte stromal cells and paracrine enhancement of breast cancer cell growth. In contrast, adiponectin, another adipokine is protective against breast cancer cell proliferation and insulin resistance. AMP-activated protein kinase (AMPK activity has been found decreased in visceral adipose tissue of insulin-resistant patients. Lipopolysaccharides (LPS link systemic inflammation to high fat diet-induced insulin resistance. Modulation of LPS-induced adipokine production by metformin and AMPK activation might represent an alternative way to treat both, insulin resistance and breast cancer. Methods Human preadipocytes obtained from surgical biopsies were expanded and differentiated in vitro into adipocytes, and incubated with siRNA targeting AMPKalpha1 (72 h, LPS (24 h, 100 μg/ml and/or metformin (24 h, 1 mM followed by mRNA extraction and analyses. Additionally, the supernatant of preadipocytes or derived-adipocytes in culture for 24 h was used as conditioned media to evaluate MCF-7 breast cancer cell proliferation. Results Conditioned media from preadipocyte-derived adipocytes, but not from undifferentiated preadipocytes, increased MCF-7 cell proliferation (p Conclusions Adipocyte-secreted factors enhance breast cancer cell proliferation, while AMPK and metformin improve the LPS-induced adipokine imbalance. Possibly, AMPK activation may provide a new way not only to improve the obesity-related adipokine profile and insulin resistance, but also to prevent obesity-related breast cancer development and progression.

  5. Natural resistance to ascorbic acid induced oxidative stress is mainly mediated by catalase activity in human cancer cells and catalase-silencing sensitizes to oxidative stress

    Directory of Open Access Journals (Sweden)

    Klingelhoeffer Christoph

    2012-05-01

    Full Text Available Abstract Background Ascorbic acid demonstrates a cytotoxic effect by generating hydrogen peroxide, a reactive oxygen species (ROS involved in oxidative cell stress. A panel of eleven human cancer cell lines, glioblastoma and carcinoma, were exposed to serial dilutions of ascorbic acid (5-100 mmol/L. The purpose of this study was to analyse the impact of catalase, an important hydrogen peroxide-detoxifying enzyme, on the resistance of cancer cells to ascorbic acid mediated oxidative stress. Methods Effective concentration (EC50 values, which indicate the concentration of ascorbic acid that reduced the number of viable cells by 50%, were detected with the crystal violet assay. The level of intracellular catalase protein and enzyme activity was determined. Expression of catalase was silenced by catalase-specific short hairpin RNA (sh-RNA in BT-20 breast carcinoma cells. Oxidative cell stress induced apoptosis was measured by a caspase luminescent assay. Results The tested human cancer cell lines demonstrated obvious differences in their resistance to ascorbic acid mediated oxidative cell stress. Forty-five percent of the cell lines had an EC50 > 20 mmol/L and fifty-five percent had an EC50 50 of 2.6–5.5 mmol/L, glioblastoma cells were the most susceptible cancer cell lines analysed in this study. A correlation between catalase activity and the susceptibility to ascorbic acid was observed. To study the possible protective role of catalase on the resistance of cancer cells to oxidative cell stress, the expression of catalase in the breast carcinoma cell line BT-20, which cells were highly resistant to the exposure to ascorbic acid (EC50: 94,9 mmol/L, was silenced with specific sh-RNA. The effect was that catalase-silenced BT-20 cells (BT-20 KD-CAT became more susceptible to high concentrations of ascorbic acid (50 and 100 mmol/L. Conclusions Fifty-five percent of the human cancer cell lines tested were unable to protect themselves

  6. Pharmacological Effects of Serum Containing Chinese Medicine Bushen Huayu Jiedu Compound Recipe(补肾化瘀解毒复方)in Lung Cancer Drug-resistance Cells

    Institute of Scientific and Technical Information of China (English)

    CAO Yong; XIA Qing-hua; MENG Hua; ZHONG An-pu

    2008-01-01

    Objective: To explore the pharmacologic effects of Chinese medicine Bushen Huayu Jiedu Compound Recipe (补肾化瘀解毒复方, BSHYJDR) in drug-resistance cells of lung cancer. Methods: Human lung adenocarcinoma A549/DDP cell strain was selected, serum pharmacology and flow cytometer (FCM) method were adopted, $180 tumor-bearing mice and normal mice were given, through gastrogavage, different doses of a decocted concentration of BSHYJDR. Serum from the abdominal aorta was taken to observe the effect of drug-serum on cisplatin (DDP) concentration, free Ca2+. concentration and the expression of lung drug-resistance protein LRP-56 in A549/DDP cells. Results: Compared with the drug-resistance group, the intracellular DDP concentration in the group taking a high dose and the normal group of Chinese medicine showed significant difference (P0.05). Compared with the drug-resistance group, the Ca2+ concentration in cells and the expression of LRP in lung cancer drug-resistance cells A549/DDP of the high-dose group, the low-dose group and the normal group of Chinese medicine were significantly different (all P<0.01), the LRP expression of the normal group was obviously higher than that of the drug-resistance group (P<0.05). Conclusion: It was indicated that serum containing Chinese medicine BSHYJDR in the tumor-bearing mice and the normal mice had certainly different, tumor-bearing mice serum containing could improve drug concentration in lung cancer drug-resistance cells, prevent the inflow and release of Ca2+, and inhibit the expression of the drug-resistance gene in the lung cancer drug-resistance cells, which might be the mechanism of BSHYJDR in enhancing the efficacy in reversing and inhibiting tumor.

  7. Advances of Drug Resistance Marker of Gemcitabine for Non-small Cell Lung Cancer

    Directory of Open Access Journals (Sweden)

    Baorui LIU

    2011-05-01

    Full Text Available With the development of pharmacogenomics and pharmacogenetics, personal therapy based on genes has become one of the most effective ways to enhance chemotherapeutic effect on non-small cell lung cancer (NSCLC patients. Much attention has been paid to validate the predictive biomarkers of chemotherapy in order to guide chemotherapy and enhance effect in general. Gemcitabine is one of the common agents treating NSCLC recently. This review is mainly about the recent reports on potential biomarkers of Gemcitabine in tailored therapy of NSCLC.

  8. Biodegradable cationic polymeric nanocapsules for overcoming multidrug resistance and enabling drug-gene co-delivery to cancer cells

    Science.gov (United States)

    Chen, Chih-Kuang; Law, Wing-Cheung; Aalinkeel, Ravikumar; Yu, Yun; Nair, Bindukumar; Wu, Jincheng; Mahajan, Supriya; Reynolds, Jessica L.; Li, Yukun; Lai, Cheng Kee; Tzanakakis, Emmanuel S.; Schwartz, Stanley A.; Prasad, Paras N.; Cheng, Chong

    2014-01-01

    Having unique architectural features, cationic polymeric nanocapsules (NCs) with well-defined covalently stabilized biodegradable structures were generated as potentially universal and safe therapeutic nanocarriers. These NCs were synthesized from allyl-functionalized cationic polylactide (CPLA) by highly efficient UV-induced thiol-ene interfacial cross-linking in transparent miniemulsions. With tunable nanoscopic sizes, negligible cytotoxicity and remarkable degradability, they are able to encapsulate doxorubicin (Dox) with inner cavities and bind interleukin-8 (IL-8) small interfering RNA (siRNA) with cationic shells. The Dox-encapsulated NCs can effectively bypass the P-glycoprotein (Pgp)-mediated multidrug resistance of MCF7/ADR cancer cells, thereby resulting in increased intracellular drug concentration and reduced cell viability. In vitro studies also showed that the NCs loaded with Dox, IL-8 siRNA and both agents can be readily taken up by PC3 prostate cancer cells, resulting in a significant chemotherapeutic effect and/or IL-8 gene silencing.Having unique architectural features, cationic polymeric nanocapsules (NCs) with well-defined covalently stabilized biodegradable structures were generated as potentially universal and safe therapeutic nanocarriers. These NCs were synthesized from allyl-functionalized cationic polylactide (CPLA) by highly efficient UV-induced thiol-ene interfacial cross-linking in transparent miniemulsions. With tunable nanoscopic sizes, negligible cytotoxicity and remarkable degradability, they are able to encapsulate doxorubicin (Dox) with inner cavities and bind interleukin-8 (IL-8) small interfering RNA (siRNA) with cationic shells. The Dox-encapsulated NCs can effectively bypass the P-glycoprotein (Pgp)-mediated multidrug resistance of MCF7/ADR cancer cells, thereby resulting in increased intracellular drug concentration and reduced cell viability. In vitro studies also showed that the NCs loaded with Dox, IL-8 siRNA and both

  9. Targeting AKT with the allosteric AKT inhibitor MK-2206 in non-small cell lung cancer cells with acquired resistance to cetuximab.

    Science.gov (United States)

    Iida, Mari; Brand, Toni M; Campbell, David A; Starr, Megan M; Luthar, Neha; Traynor, Anne M; Wheeler, Deric L

    2013-06-01

    The epidermal growth factor receptor (EGFR) is a central regulator of tumor progression in human cancers. Cetuximab is an anti-EGFR monoclonal antibody that has been approved for use in oncology. Despite clinical success the majority of patients do not respond to cetuximab and those who initially respond frequently acquire resistance. To understand how tumor cells acquire resistance to cetuximab we developed a model of resistance using the non-small cell lung cancer line NCI-H226. We found that cetuximab-resistant (Ctx (R) ) clones manifested strong activation of EGFR, PI3K/AKT and MAPK. To investigate the role of AKT signaling in cetuximab resistance we analyzed the activation of the AKT pathway effector molecules using a human AKT phospho-antibody array. Strong activation was observed in Ctx (R) clones for several key AKT substrates including c-jun, GSK3β, eIF4E, rpS6, IKKα, IRS-1 and Raf1. Inhibition of AKT signaling by siAKT1/2 or by the allosteric AKT inhibitor MK-2206 resulted in robust inhibition of cell proliferation in all Ctx (R) clones. Moreover, the combinational treatment of cetuximab and MK-2206 resulted in further decreases in proliferation than either drug alone. This combinatorial treatment resulted in decreased activity of both AKT and MAPK thus highlighting the importance of simultaneous pathway inhibition to maximally affect the growth of Ctx (R) cells. Collectively, our findings demonstrate that AKT activation is an important pathway in acquired resistance to cetuximab and suggests that combinatorial therapy directed at both the AKT and EGFR/MAPK pathways may be beneficial in this setting. PMID:23760490

  10. The broad-spectrum metalloproteinase inhibitor BB-94 inhibits growth, HER3 and Erk activation in fulvestrant-resistant breast cancer cell lines

    DEFF Research Database (Denmark)

    Kirkegaard, Tove; Yde, Christina Westmose; Kveiborg, Marie; Lykkesfeldt, Anne E

    2014-01-01

    consequently increased cell growth. In this study, we investigated the importance of HER receptors, in particular HER3, and HER ligand shedding for growth and signaling in human MCF-7 breast cancer cells and MCF-7-derived sublines resistant to the antiestrogen fulvestrant. The HER3/HER4 ligand heregulin 1β...... induced phosphorylation of HER3, Akt and Erk, and partly rescued fulvestrant-inhibited growth of MCF-7 cells. HER3 ligands were found to be produced and shed from the fulvestrant-resistant cells as conditioned medium from fulvestrant-resistant MCF-7 cells induced phosphorylation of HER3 and Akt in MCF-7...... cells. This was prevented by treatment of resistant cells with the metalloproteinase inhibitor TAPI-2. Only the broad-spectrum metalloproteinase inhibitor BB-94, and not the more selective inhibitors GM6001 or TAPI-2, which inhibited shedding of the HER ligands produced by the fulvestrant...

  11. Poly(amido)amine (PAMAM) dendrimer-cisplatin complexes for chemotherapy of cisplatin-resistant ovarian cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Yellepeddi, Venkata Kashyap; Vangara, Kiran Kumar; Palakurthi, Srinath, E-mail: palakurthi@tamhsc.edu [Texas A and M Health Science Center, Irma Lerma Rangel College of Pharmacy (United States)

    2013-09-15

    Dendrimer-cisplatin complexes were prepared using PAMAM dendrimers with terminal -NH{sub 2} and -COOH groups as well as biotin-conjugated dendrimers. Preformulation parameters of dendrimer-cisplatin complexes were studied using differential scanning calorimetry (DSC) and inductively coupled plasma-mass spectrometry (ICP-MS). Cytotoxicity and mechanism of cytotoxicity of dendrimer-cisplatin complexes was investigated in OVCAR-3, SKOV, A2780 and cisplatin-resistant CP70 human ovarian cancer cell lines. The loading of cisplatin in dendrimers was {approx}11 % (w/w). PAMAM G4 dendrimers with amine surface groups (biotinylated and native) have shown 2.5- to 3.0-fold reduction in IC{sub 50} values in ovarian cancer cells when compared with carboxylate surface dendrimers (p < 0.05). A correlation was observed among cytotoxicity of the complexes, cellular uptake, and platinum-DNA adduct formation. Treatment with dendrimer-cisplatin complexes resulted in a 7.0-fold increase (p < 0.05) in expression of apoptotic genes (Bcl2, Bax, p53) and 13.2- to 27.1-fold increase (p < 0.05) in the activity of caspases 3, 8, and 9 in vitro. Results suggest that PAMAM dendrimers can be used as potential carrier for cisplatin chemotherapy of ovarian cancer.

  12. Alectinib for choroidal metastasis in a patient with crizotinib-resistant ALK rearranged positive non-small cell lung cancer

    Directory of Open Access Journals (Sweden)

    Okuma Y

    2015-06-01

    Full Text Available Yusuke Okuma,1,2 Yuichiro Tanaka,3 Tina Kamei,1 Yukio Hosomi,1 Tatsuru Okamura1 1Department of Thoracic Oncology and Respiratory Medicine, Tokyo Metropolitan Cancer and Infectious diseases Center Komagome Hospital, 2Division of Oncology, Research Center for Medical Sciences, The Jikei University School of Medicine, 3Department of Ophthalmology, Tokyo Metropolitan Cancer and Infectious diseases Center Komagome Hospital, Tokyo, Japan Abstract: Choroidal metastasis is rare in cancer patients. Small molecules of molecular targeted agents for lung cancer with actionable mutations were reported to be palliated for symptoms caused by choroidal metastasis. Visual disturbance by choroidal metastasis significantly decreases quality of life during the patient’s remaining lifespan; therefore, radiotherapy or laser photocoagulation is proposed with consensus. However, improvement in survival with matched molecular targeted agents for oncogenic driver mutations reminds us to also be concerned with late treatment toxicities. A 30-year-old female patient previously treated with crizotinib harboring ALK rearranged non-small cell lung cancer complained of visual disturbance, fever, and bone pains undergoing anti-PD-1 antibody treatment. A decreased proportion of ALK fusion was demonstrated by fluorescence in situ hybridization in liver metastasis compared to the primary site in a chemo-naïve state. She was diagnosed with low vision, choroidal metastasis and retinal detachment. Therefore, she started alectinib treatment and both her ocular and systemic symptoms were palliated in a week. Later, she temporarily discontinued alectinib because of skin rash although the choroidal metastasis and retinal detachment resolved and she regained low vision completely at 2 weeks. She obtained partial response with alectinib for more than 5 months after recovering from skin rash. Keywords: lung cancer, ALK rearrangement, alectinib, choroidal metastasis, molecular targeted

  13. MiR-503 regulates cisplatin resistance of human gastric cancer cell lines by targeting IGF1R and BCL2

    Institute of Scientific and Technical Information of China (English)

    Wang Tongshan; Ge Gaoxia; Ding Yin; Zhou Xin; Huang Zebo; Zhu Wei; Shu Yongqian

    2014-01-01

    Background Studies have shown that the drug resistance of gastric cancer cells can be modulated by abnormal expression of microRNAs (miRNAs).We investigated the role of miR-503 in the development of cisplatin resistance in human gastric cancer cell lines.Methods MiR-503 expression was measured by quantitative real-time PCR.MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and clonogenic assays were used to examine changes in cell viability and the drug resistance phenotype of cancer cells associated with upregulation or downregulation of the miRNA.A dual-luciferase activity assay was used to verify target genes of miR-503.Immunohistochemistry,Western blotting analysis,and a flow cytometric apoptosis assay were used to elucidate the mechanism by which miR-503 modulates drug resistance in cancer cells.Results MiR-503 was significantly downregulated in gastric cancer tissues and several gastric cancer cell lines.Additionally,downregulation of miR-503 in the cisplatin (DDP)-resistant gastric cancer cell line SGC7901/DDP was concurrent with the upregulation of insulin-like growth factor-1 receptor (IGF1R) and B-cell lymphoma 2 (BCL2) expression compared with the parental SGC7901 cell line.An in vitro drug sensitivity assay showed that overexpression of miR-503 sensitized SGC7901/DDP cells to cisplatin.The luciferase activity of reporters driven by IGF1R and BCL2 3'-untranslated regions in SGC7901/DDP cells suggested that IGF1R and BCL2 were both direct target genes of miR-503.Enforced miR-503 expression in SGC7901/DDP cells reduced expression of the target proteins,inhibited proliferation,and sensitized the cells to DDP-induced apoptosis.Conclusion Our findings suggest that hsa-miR-503 modulates cisplatin resistance of human gastric cancer cells at least in part by targeting IGF1R and BCL2.

  14. Sunitinib significantly suppresses the proliferation, migration, apoptosis resistance, tumor angiogenesis and growth of triple-negative breast cancers but increases breast cancer stem cells.

    Science.gov (United States)

    Chinchar, Edmund; Makey, Kristina L; Gibson, John; Chen, Fang; Cole, Shelby A; Megason, Gail C; Vijayakumar, Srinivassan; Miele, Lucio; Gu, Jian-Wei

    2014-01-01

    The majority of triple-negative breast cancers (TNBCs) are basal-like breast cancers. However there is no reported study on anti-tumor effects of sunitinib in xenografts of basal-like TNBC (MDA-MB-468) cells. In the present study, MDA-MB-231, MDA-MB-468, MCF-7 cells were cultured using RPMI 1640 media with 10% FBS. Vascular endothelia growth factor (VEGF) protein levels were detected using ELISA (R & D Systams). MDA-MB-468 cells were exposed to sunitinib for 18 hours for measuring proliferation (3H-thymidine incorporation), migration (BD Invasion Chamber), and apoptosis (ApopTag and ApoScreen Anuexin V Kit). The effect of sunitinib on Notch-1 expression was determined by Western blot in cultured MDA-MB-468 cells. 10(6) MDA-MB-468 cells were inoculated into the left fourth mammary gland fat pad in athymic nude-foxn1 mice. When the tumor volume reached 100 mm(3), sunitinib was given by gavage at 80 mg/kg/2 days for 4 weeks. Tumor angiogenesis was determined by CD31 immunohistochemistry. Breast cancer stem cells (CSCs) isolated from the tumors were determined by flow cytometry analysis using CD44(+)/CD24(-) or low. ELISA indicated that VEGF was much more highly expressed in MDA-MB-468 cells than MDA-MB-231 and MCF-7 cells. Sunitinib significantly inhibited the proliferation, invasion, and apoptosis resistance in cultured basal like breast cancer cells. Sunitinib significantly increased the expression of Notch-1 protein in cultured MDA-MB-468 or MDA-MB-231 cells. The xenograft models showed that oral sunitinib significantly reduced the tumor volume of TNBCs in association with the inhibition of tumor angiogeneisis, but increased breast CSCs. These findings support the hypothesis that the possibility should be considered of sunitinib increasing breast CSCs though it inhibits TNBC tumor angiogenesis and growth/progression, and that effects of sunitinib on Notch expression and hypoxia may increase breast cancer stem cells. This work provides the groundwork for an

  15. Adenovirus vector infection of non-small-cell lung cancer cells is a trigger for multi-drug resistance mediated by P-glycoprotein.

    Science.gov (United States)

    Tomono, Takumi; Kajita, Masahiro; Yano, Kentaro; Ogihara, Takuo

    2016-08-01

    P-glycoprotein (P-gp) is an ATP-binding cassette protein involved in cancer multi-drug resistance (MDR). It has been reported that infection with some bacteria and viruses induces changes in the activities of various drug-metabolizing enzymes and transporters, including P-gp. Although human adenoviruses (Ad) cause the common cold, the effect of Ad infection on MDR in cancer has not been established. In this study, we investigated whether Ad infection is a cause of MDR in A549, H441 and HCC827 non-small-cell lung cancer (NSCLC) cell lines, using an Ad vector system. We found that Ad vector infection of NSCLC cell lines induced P-gp mRNA expression, and the extent of induction was dependent on the number of Ad vector virus particles and the infection time. Heat-treated Ad vector, which is not infectious, did not alter P-gp mRNA expression. Uptake experiments with doxorubicin (DOX), a P-gp substrate, revealed that DOX accumulation was significantly decreased in Ad vector-infected A549 cells. The decrease of DOX uptake was blocked by verapamil, a P-gp inhibitor. Our results indicated that Ad vector infection of NSCLC cells caused MDR mediated by P-gp overexpression. The Ad vector genome sequence is similar to that of human Ad, and therefore human Ad infection of lung cancer patients may lead to chemoresistance in the clinical environment. PMID:27286705

  16. Role of Caveolin 1, E-Cadherin, Enolase 2 and PKCalpha on resistance to methotrexate in human HT29 colon cancer cells

    DEFF Research Database (Denmark)

    Selga, Elisabet; Morales Torres, Christina; Noé, Véronique;

    2008-01-01

    ABSTRACT: BACKGROUND: Methotrexate is one of the earliest cytotoxic drugs used in cancer therapy, and despite the isolation of multiple other folate antagonists, methotrexate maintains its significant role as a treatment for different types of cancer and other disorders. The usefulness of treatment...... with methotrexate is limited by the development of drug resistance, which may be acquired through different ways. To get insights into the mechanisms associated with drug resistance and sensitization we performed a functional analysis of genes deregulated in methotrexate resistant cells, either due to...

  17. Selective Intracellular Delivery of Recombinant Arginine Deiminase (ADI) Using pH-Sensitive Cell Penetrating Peptides To Overcome ADI Resistance in Hypoxic Breast Cancer Cells.

    Science.gov (United States)

    Yeh, Tzyy-Harn; Chen, Yun-Ru; Chen, Szu-Ying; Shen, Wei-Chiang; Ann, David K; Zaro, Jennica L; Shen, Li-Jiuan

    2016-01-01

    Arginine depletion strategies, such as pegylated recombinant arginine deiminase (ADI-PEG20), offer a promising anticancer treatment. Many tumor cells have suppressed expression of a key enzyme, argininosuccinate synthetase 1 (ASS1), which converts citrulline to arginine. These tumor cells become arginine auxotrophic, as they can no longer synthesize endogenous arginine intracellularly from citrulline, and are therefore sensitive to arginine depletion therapy. However, since ADI-PEG20 only depletes extracellular arginine due to low internalization, ASS1-expressing cells are not susceptible to treatment since they can synthesize arginine intracellularly. Recent studies have found that several factors influence ASS1 expression. In this study, we evaluated the effect of hypoxia, frequently encountered in many solid tumors, on ASS1 expression and its relationship to ADI-resistance in human MDA-MB-231 breast cancer cells. It was found that MDA-MB-231 cells developed ADI resistance in hypoxic conditions with increased ASS1 expression. To restore ADI sensitivity as well as achieve tumor-selective delivery under hypoxia, we constructed a pH-sensitive cell penetrating peptide (CPP)-based delivery system to carry ADI inside cells to deplete both intra- and extracellular arginine. The delivery system was designed to activate the CPP-mediated internalization only at the mildly acidic pH (6.5-7) associated with the microenvironment of hypoxic tumors, thus achieving better selectivity toward tumor cells. The pH sensitivity of the CPP HBHAc was controlled by recombinant fusion to a histidine-glutamine (HE) oligopeptide, generating HBHAc-HE-ADI. The tumor distribution of HBHAc-HE-ADI was comparable to ADI-PEG20 in a mouse xenograft model of human breast cancer cells in vivo. In addition, HBHAc-HE-ADI showed increased in vitro cellular uptake in cells incubated in a mildly acidic pH (hypoxic conditions) compared to normal pH (normoxic conditions), which correlated with p

  18. Lung cancer - small cell

    Science.gov (United States)

    Cancer - lung - small cell; Small cell lung cancer; SCLC ... About 15% of all lung cancer cases are SCLC. Small cell lung cancer is slightly more common in men than women. Almost all cases of SCLC ...

  19. Lung cancer - small cell

    Science.gov (United States)

    Cancer - lung - small cell; Small cell lung cancer; SCLC ... About 15% of all lung cancer cases are SCLC. Small cell lung cancer is slightly more common in men than women. Almost all cases of SCLC are ...

  20. SU-E-T-565: RAdiation Resistance of Cancer CElls Using GEANT4 DNA: RACE

    International Nuclear Information System (INIS)

    Purpose: The objective of the RACE project is to develop a comparison between Monte Carlo simulation using the Geant4-DNA toolkit and measurements of radiation damage on 3D melanoma and chondrosarcoma culture cells coupled with gadolinium nanoparticles. We currently expose the status of the developments regarding simulations. Methods: Monte Carlo studies are driven using the Geant4 toolkit and the Geant4-DNA extension. In order to model the geometry of a cell population, the opensource CPOP++ program is being developed for the geometrical representation of 3D cell populations including a specific cell mesh coupled with a multi-agent system. Each cell includes cytoplasm and nucleus. The correct modeling of the cell population has been validated with confocal microscopy images of spheroids. The Geant4 Livermore physics models are used to simulate the interactions of a 250 keV X-ray beam and the production of secondaries from gadolinium nanoparticles supposed to be fixed on the cell membranes. Geant4-DNA processes are used to simulate the interactions of charged particles with the cells. An atomistic description of the DNA molecule, from PDB (Protein Data Bank) files, is provided by the so-called PDB4DNA Geant4 user application we developed to score energy depositions in DNA base pairs and sugar-phosphate groups. Results: At the microscopic level, our simulations enable assessing microscopic energy distribution in each cell compartment of a realistic 3D cell population. Dose enhancement factors due to the presence of gadolinium nanoparticles can be estimated. At the nanometer scale, direct damages on nuclear DNA are also estimated. Conclusion: We successfully simulated the impact of direct radiations on a realistic 3D cell population model compatible with microdosimetry calculations using the Geant4-DNA toolkit. Upcoming validation and the future integration of the radiochemistry module of Geant4-DNA will propose to correlate clusters of ionizations with in vitro

  1. SU-E-T-565: RAdiation Resistance of Cancer CElls Using GEANT4 DNA: RACE

    Energy Technology Data Exchange (ETDEWEB)

    Perrot, Y; Payno, H; Delage, E; Maigne, L [Clermont Universite, CNRS/IN2P3, Laboratoire de Physique Corpusculaire de Clermont-Ferrand, Aubiere (France); Incerti, S [Universite Bordeaux 1, CNRS/IN2P3, Centres d' Etudes Nucleaires de Bordeaux-Gradignan, Gradignan (France); Debiton, E; Peyrode, C; Chezal, J; Miot-Noirault, E; Degoul, F [Clermont Universite, Universite d' Auvergne, Imagerie Moleculaire et Therapie Vectorisee, INSERM U990, Centre Jean Perrin, Clermont-Ferrand (France)

    2014-06-01

    Purpose: The objective of the RACE project is to develop a comparison between Monte Carlo simulation using the Geant4-DNA toolkit and measurements of radiation damage on 3D melanoma and chondrosarcoma culture cells coupled with gadolinium nanoparticles. We currently expose the status of the developments regarding simulations. Methods: Monte Carlo studies are driven using the Geant4 toolkit and the Geant4-DNA extension. In order to model the geometry of a cell population, the opensource CPOP++ program is being developed for the geometrical representation of 3D cell populations including a specific cell mesh coupled with a multi-agent system. Each cell includes cytoplasm and nucleus. The correct modeling of the cell population has been validated with confocal microscopy images of spheroids. The Geant4 Livermore physics models are used to simulate the interactions of a 250 keV X-ray beam and the production of secondaries from gadolinium nanoparticles supposed to be fixed on the cell membranes. Geant4-DNA processes are used to simulate the interactions of charged particles with the cells. An atomistic description of the DNA molecule, from PDB (Protein Data Bank) files, is provided by the so-called PDB4DNA Geant4 user application we developed to score energy depositions in DNA base pairs and sugar-phosphate groups. Results: At the microscopic level, our simulations enable assessing microscopic energy distribution in each cell compartment of a realistic 3D cell population. Dose enhancement factors due to the presence of gadolinium nanoparticles can be estimated. At the nanometer scale, direct damages on nuclear DNA are also estimated. Conclusion: We successfully simulated the impact of direct radiations on a realistic 3D cell population model compatible with microdosimetry calculations using the Geant4-DNA toolkit. Upcoming validation and the future integration of the radiochemistry module of Geant4-DNA will propose to correlate clusters of ionizations with in vitro

  2. Emergence of cytotoxic resistance in cancer cell populations: Single-cell mechanisms and population-level consequences

    Science.gov (United States)

    Lorenzi, Tommaso; Chisholm, Rebecca H.; Lorz, Alexander; Larsen, Annette K.; de Almeida, Luís Neves; Escargueil, Alexandre; Clairambault, Jean

    2016-06-01

    We formulate an individual-based model and a population model of phenotypic evolution, under cytotoxic drugs, in a cancer cell population structured by the expression levels of survival-potential and proliferation-potential. We apply these models to a recently studied experimental system. Our results suggest that mechanisms based on fundamental laws of biology can reversibly push an actively-proliferating, and drug-sensitive, cell population to transition into a weakly-proliferative and drug-tolerant state, which will eventually facilitate the emergence of more potent, proliferating and drug-tolerant cells.

  3. Overexpression of the ATP-binding cassette half-transporter, ABCG2 (Mxr/BCrp/ABCP1), in flavopiridol-resistant human breast cancer cells

    DEFF Research Database (Denmark)

    Robey, R W; Medina-Pérez, W Y; Nishiyama, K;

    2001-01-01

    We sought to characterize the interactions of flavopiridol with members of the ATP-binding cassette (ABC) transporter family. Cells overexpressing multidrug resistance-1 (MDR-1) and multidrug resistance-associated protein (MRP) did not exhibit appreciable flavopiridol resistance, whereas cell lines...... overexpressing the ABC half-transporter, ABCG2 (MXR/BCRP/ABCP1), were found to be resistant to flavopiridol. Flavopiridol at a concentration of 10 microM was able to prevent MRP-mediated calcein efflux, whereas Pgp-mediated transport of rhodamine 123 was unaffected at flavopiridol concentrations of up to 100...... microM. To determine putative mechanisms of resistance to flavopiridol, we exposed the human breast cancer cell line MCF-7 to incrementally increasing concentrations of flavopiridol. The resulting resistant subline, MCF-7 FLV1000, is maintained in 1,000 nM flavopiridol and was found to be 24-fold...

  4. Autophagy inhibition plays the synergetic killing roles with radiation in the multi-drug resistant SKVCR ovarian cancer cells

    International Nuclear Information System (INIS)

    Autophagy has attracted attentions as a novel mechanism for tumor development. In this study Human ovarian carcinoma cell line SKOV3 and multidrug-resistant phenotype SKVCR cells were used and the roles of autophagy in radiation-induced cell death were analyzed. Cell viability was examined by colony formation and cell counting kit-8 (CCK-8) assay, 3MA and ZVAD were used to block autophagy and apoptosis, respectively. Quantitative real-time PCR was used to detect mRNA level and Western blot was used to detect protein expression, monodansylcadaverine (MDC) staining and flow cytometery were used for autophagy, apoptosis and cell cycle dynamics, respectively. (1) The radiosensitivity exhibited differently in SKOV3 and SKVCR cells (SKOV3: D0=3.37, SKVCR: D0= 4.18); compared with SKOV3 the constitutive expression of MAPLC3 in SKVCR was higher, but no change of Caspase-3 and cleaved Caspase-3. (2) The ionizing radiation (IR)- induced apoptosis and autophagy were significant in both cells (P<0.05); inhibition of apoptosis with ZVAD showed no impact on survival of SKOV3 and SKVCR cells after radiation, while inhibition of autophagy significantly decreased viability in SKVCR cells, for SKVO3 cells only low level of radiation (2 Gy and 4 Gy) could decrease the viability(P<0.05). (3) ZVAD inhibited apoptosis and autophagy in both cells, 3MA inhibit apoptosis in SKOV3, and promote apoptosis in SKVCR, together with inhibition of autophagy. (4) G2/M arrest was induced by radiation in both cells; the accumulation of G2/M was more significant in SKOV3, 3MA attenuated the radiation-induced S phase delay in SKVCR. IR-induced autophagy provides a self-protective mechanism against radiotherapy in SKVCR cells, the use of autophagy inhibitor, 3MA, increases the killing effects of radiation by inhibiting autophagy and radiation- induced S phase delay, also by the increase of apoptosis, which suggests a better therapeutic strategy in drug- resistant SKVCR ovarian cancer cells

  5. Differences in cell cycle regulation after platinum derivatives treatment in sensitive and cisplatin resistant ovarian cancer cell lines

    Czech Academy of Sciences Publication Activity Database

    Horváth, Viktor; Souček, Karel; Šindlerová, Lenka; Hofmanová, Jiřina; Sova, Petr; Kozubík, Alois

    Bratislava : Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, 2006 - (Boháčová, V.; Breier, A.; Zbyňovská, D.; Zliechovec, J.). s. 69-69 ISBN 80-969532-6-5. [Biochemický zjazd /20./. 12.09.2006-16.09.2006, Piešťany] R&D Projects: GA AV ČR(CZ) 1QS500040507; GA MPO(CZ) PZ-Z2/29 Institutional research plan: CEZ:AV0Z50040507 Keywords : ovarian cancer * cisplatin * resistance Subject RIV: BO - Biophysics

  6. Prostaglandin receptor EP3 mediates growth inhibitory effect of aspirin through androgen receptor and contributes to castration resistance in prostate cancer cells.

    Science.gov (United States)

    Kashiwagi, Eiji; Shiota, Masaki; Yokomizo, Akira; Itsumi, Momoe; Inokuchi, Junichi; Uchiumi, Takeshi; Naito, Seiji

    2013-06-01

    Although numerous epidemiological studies show aspirin to reduce risk of prostate cancer, the mechanism of this effect is unclear. Here, we first confirmed that aspirin downregulated androgen receptor (AR) and prostate-specific antigen in prostate cancer cells. We also found that aspirin upregulated prostaglandin receptor subtype EP3 but not EP2 or EP4. The EP3 antagonist L798106 and EP3 knockdown increased AR expression and cell proliferation, whereas the EP3 agonist sulprostone decreased them, indicating that EP3 affects AR expression. Additionally, EP3 (PTGER3) transcript levels were significantly decreased in human prostate cancer tissues compared with those in normal human prostate tissues, suggesting that EP3 is important to prostate carcinogenesis. Decreased EP3 expression was also seen in castration-resistant subtype CxR cells compared with parental LNCaP cells. Finally, we found that aspirin and EP3 modulators affected prostate cancer cell growth. Taken together, aspirin suppressed LNCaP cell proliferation via EP3 signaling activation; EP3 downregulation contributed to prostate carcinogenesis and to progression from androgen-dependent prostate cancer to castration-resistant prostate cancer by regulating AR expression. In conclusion, cyclooxygenases and EP3 may represent attractive therapeutic molecular targets in androgen-dependent prostate cancer. PMID:23493387

  7. Overcoming acquired drug resistance in colorectal cancer cells by targeted delivery of 5-FU with EGF grafted hollow mesoporous silica nanoparticles

    Science.gov (United States)

    Chen, Lijue; She, Xiaodong; Wang, Tao; He, Li; Shigdar, Sarah; Duan, Wei; Kong, Lingxue

    2015-08-01

    Acquired drug resistance (ADR) can be developed in colorectal cancer cells after 5-fluorouracil (5-FU) treatment and diminish the effectiveness of chemotherapy. In this work, acquired 5-FU resistance in the colorectal cancer cell line SW480 was obtained with the up-regulation of dihydropyrimidine dehydrogenase (DPYD) gene expression which can convert 5-FU to its inactive metabolite. To overcome ADR in colorectal cancer, hollow mesoporous silica nanoparticles (HMSNs) grafted with epidermal growth factor (EGF) were used as nanocarriers to deliver 5-FU to colorectal cancer cells with acquired drug resistance. The effect and mechanism of 5-FU loaded EGF grafted HMSNs (EGF-HMSNs-5-FU) in overcoming acquired drug resistance in SW480/ADR cells were studied. The EGF-HMSNs were demonstrated to be specifically internalized in EGFR overexpressed SW480/ADR cells via a receptor-mediated endocytosis and can escape from endo-lysosomes. The EGF-HMSNs-5-FU exhibited much higher cytotoxicity on SW480/ADR cells than HMSNs-5-FU and free 5-FU while the plain HMSNs did not show significant cytotoxicity. The mechanism of EGF-HMSNs-5-FU in overcoming drug resistance in SW480/ADR cells could be attributed to the specific internalization of EGF-HMSNs-5-FU in EGFR overexpressed cells which can lead to high intracellular drug accumulation and cause cell death through S phase arrest.Acquired drug resistance (ADR) can be developed in colorectal cancer cells after 5-fluorouracil (5-FU) treatment and diminish the effectiveness of chemotherapy. In this work, acquired 5-FU resistance in the colorectal cancer cell line SW480 was obtained with the up-regulation of dihydropyrimidine dehydrogenase (DPYD) gene expression which can convert 5-FU to its inactive metabolite. To overcome ADR in colorectal cancer, hollow mesoporous silica nanoparticles (HMSNs) grafted with epidermal growth factor (EGF) were used as nanocarriers to deliver 5-FU to colorectal cancer cells with acquired drug resistance. The

  8. Cell of origin of lung cancer

    OpenAIRE

    Hanna, Jennifer M.; Onaitis, Mark W.

    2013-01-01

    Lung cancer is the leading cause of cancer deaths worldwide, and current therapies are disappointing. Elucidation of the cell(s) of origin of lung cancer may lead to new therapeutics. In addition, the discovery of putative cancer-initiating cells with stem cell properties in solid tumors has emerged as an important area of cancer research that may explain the resistance of these tumors to currently available therapeutics. Progress in our understanding of normal tissue stem cells, tumor cell o...

  9. Pancreatic adenocarcinoma upregulated factor (PAUF) confers resistance to pancreatic cancer cells against oncolytic parvovirus H-1 infection through IFNA receptor-mediated signaling.

    Science.gov (United States)

    Kaowinn, Sirichat; Cho, Il-Rae; Moon, Jeong; Jun, Seung Won; Kim, Chang Seok; Kang, Ho Young; Kim, Manbok; Koh, Sang Seok; Chung, Young-Hwa

    2015-04-01

    Pancreatic adenocarcinoma upregulated factor (PAUF), a novel oncogene, plays a crucial role in the development of pancreatic cancer, including its metastasis and proliferation. Therefore, PAUF-expressing pancreatic cancer cells could be important targets for oncolytic virus-mediated treatment. Panc-1 cells expressing PAUF (Panc-PAUF) showed relative resistance to parvovirus H-1 infection compared with Panc-1 cells expressing an empty vector (Panc-Vec). Of interest, expression of type I IFN-α receptor (IFNAR) was higher in Panc-PAUF cells than in Panc-Vec cells. Increased expression of IFNAR in turn increased the activation of Stat1 and Tyk2 in Panc-PAUF cells compared with that in Panc-Vec cells. Suppression of Tyk2 and Stat1, which are important downstream molecules for IFN-α signaling, sensitized pancreatic cancer cells to parvovirus H-1-mediated apoptosis. Further, constitutive suppression of PAUF sensitized Bxpc3 pancreatic cancer cells to parvovirus H-1 infection. Taken together, these results suggested that PAUF conferred resistance to pancreatic cancer cells against oncolytic parvovirus H-1 infection through IFNAR-mediated signaling. PMID:25727013

  10. β-elemene reverses the drug resistance of lung cancer A549/DDP cells via the mitochondrial apoptosis pathway.

    Science.gov (United States)

    Yao, Cheng-Cai; Tu, Yuan-Rong; Jiang, Jie; Ye, Sheng-Fang; Du, Hao-Xin; Zhang, Yi

    2014-05-01

    β-elemene (β-ELE) is a new anticancer drug extracted from Curcuma zedoaria Roscoe and has been widely used to treat malignant tumors. Recent studies have demonstrated that β-ELE reverses the drug resistance of tumor cells. To explore the possible mechanisms of action of β-ELE, we investigated its effects on cisplatin-resistant human lung adenocarcinoma A549/DDP cells. The effects of β-ELE on the growth of A549/DDP cells in vitro were determined by MTT assay. Apoptosis was assessed by fluorescence microscopy with Hoechst 33258 staining and flow cytometry with Annexin V-FITC/PI double staining. Mitochondrial membrane potential was assessed using JC-1 fluorescence probe and laser confocal scanning microscopy, and intracellular reactive oxygen species levels were measured by 2',7'-dichlorofluorescein-diacetate staining and flow cytometry. Cytosolic glutathione content was determined using GSH kits. The expression of cytochrome c, caspase-3, procaspase-3 and the Bcl-2 family proteins was assessed by western blotting. The results demonstrated that β-ELE inhibited the proliferation of A549/DDP cells in a time- and dose-dependent manner. Furthermore, β-ELE enhanced the sensitivity of A549/DDP cells to cisplatin and reversed the drug resistance of A549/DDP cells. Consistent with a role in activating apoptosis, β-ELE decreased mitochondrial membrane potential, increased intracellular reactive oxygen species concentration and decreased the cytoplasmic glutathione levels in a time- and dose-dependent manner. The combination of β-ELE and cisplatin enhanced the protein expression of cytochrome c, caspase-3 and Bad, and reduced protein levels of Bcl-2 and procaspase-3 in the A549/DDP lung cancer cells. These results define a pathway of procaspase‑3-β-ELE function that involves decreased mitochondrial membrane potential, leading to apoptosis triggered by the release of cytochrome c into the cytoplasm and the modulation of apoptosis-related genes. The reversal of drug

  11. MicroRNA-3646 Contributes to Docetaxel Resistance in Human Breast Cancer Cells by GSK-3β/β-Catenin Signaling Pathway

    OpenAIRE

    Zhang, Xiaohui; Zhong, Shanliang; Xu, Yong; Yu, Dandan; Ma, Tengfei; Chen, Lin; Zhao, Yang; Chen, Xiu; Yang, Sujin; Wu, Yueqin; TANG, JINHAI; Zhao, Jianhua

    2016-01-01

    Acquisition of resistance to docetaxel (Doc) is one of the most important problems in treatment of breast cancer patients, but the underlying mechanisms are still not fully understood. In present study, Doc-resistant MDA-MB-231 and MCF-7 breast cancer cell lines (MDA-MB-231/Doc and MCF-7/Doc) were successfully established in vitro by gradually increasing Doc concentration on the basis of parental MDA-MB-231 and MCF-7 cell lines (MDA-MB-231/S and MCF-7/S). The potential miRNAs relevant to the ...

  12. Immunotargeting of cancer stem cells

    OpenAIRE

    Kwiatkowska-Borowczyk, Eliza P.; Gąbka-Buszek, Agnieszka; Jankowski, Jakub; Mackiewicz, Andrzej

    2015-01-01

    Cancer stem cells (CSCs) represent a distinctive population of tumour cells that control tumour initiation, progression, and maintenance. Their influence is great enough to risk the statement that successful therapeutic strategy must target CSCs in order to eradicate the disease. Because cancer stem cells are highly resistant to chemo- and radiotherapy, new tools to fight against cancer have to be developed. Expression of antigens such as ALDH, CD44, EpCAM, or CD133, which distinguish CSCs fr...

  13. Resistance mechanisms after tyrosine kinase inhibitors afatinib and crizotinib in non-small cell lung cancer, a review of the literature.

    Science.gov (United States)

    van der Wekken, A J; Saber, A; Hiltermann, T J N; Kok, K; van den Berg, A; Groen, H J M

    2016-04-01

    Targeted treatment of advanced non-small cell lung cancer patients with afatinib in EGFR mutation or crizotinib in ALK break positive patients results in profound tumor responses but inevitably induces resistance. In this review we present currently known resistance mechanisms for afatinib and crizotinib two recently approved drugs. Resistance mechanisms identified for afatinib include c-MET amplification and the V843I EGFR mutation. Expression of FGFR1, increased IL6R/JAK/STAT signaling, enhanced interference with aerobic glycolysis and autophagy are associated with resistance to afatinib. Most common resistance mechanisms for ALK break positive cases are gatekeeper mutations in the ALK gene. Also activation of the EGFR pathway, KRAS mutations, the autophagy pathway and epithelial mesenchymal transition (EMT), have been associated with resistance. Many of the proposed resistance mechanisms need to be functionally studied to proof a causative relationship with resistance. PMID:26852079

  14. Overexpression of miR-34c regulates the sensitivity to doxorubicin in drug-resistant breast cancer cell lines MCF-7/DOX

    Institute of Scientific and Technical Information of China (English)

    Han Li; Tong Li; Li-Hong Zhang

    2016-01-01

    Objective:To study the regulating effect of overexpressing miR-34c on the sensitivity to doxorubicin in drug-resistant breast cancer cell line MCF-7/DOX. Methods:Breast cancer cell lines MCF-7 and drug-resistant breast cancer cell lines MCF-7/DOX were cultured, transfected with miR-34c and negative control fragments and treated with different doses of doxorubicin;treated cells were taken, CCK-8 kits were used to detect cell viability, and RNA detection kits were used to detect mRNA contents of drug resistance-related genes. Results: miR-34a, 34b and 34c expression levels in MCF-7/DOX cell lines were lower than those in MCF-7 cell lines and the reduction of miR-34c expression level was the most significant, and mRNA contents of MDR1, BCRP, UCP2, Twist and c-Src were significantly higher than those in MCF-7 cell lines;after transfection of miR-34c, the inhibitory effect of doxorubicin on the viability of MCF-7/DOX cell lines was stronger than that of MCF-7/DOX cell lines transfected with negative control, and mRNA contents of MDR1, BCRP, UCP2, Twist and c-Src were significantly lower than those in MCF-7 cell lines transfected with negative control. Conclusions:Overexpression of miR-34c in drug-resistant breast cancer cell lines MCF-7/DOX can increase the sensitivity to doxorubicin and inhibit the expression levels of drug resistance-related genes MDR1, BCRP, UCP2, Twist and c-Src .

  15. Small-molecule synthetic compound norcantharidin reverses multi-drug resistance by regulating Sonic hedgehog signaling in human breast cancer cells.

    Directory of Open Access Journals (Sweden)

    Yu-Jen Chen

    Full Text Available Multi-drug resistance (MDR, an unfavorable factor compromising treatment efficacy of anticancer drugs, involves upregulated ATP binding cassette (ABC transporters and activated Sonic hedgehog (Shh signaling. By preparing human breast cancer MCF-7 cells resistant to doxorubicin (DOX, we examined the effect and mechanism of norcantharidin (NCTD, a small-molecule synthetic compound, on reversing multidrug resistance. The DOX-prepared MCF-7R cells also possessed resistance to vinorelbine, characteristic of MDR. At suboptimal concentration, NCTD significantly inhibited the viability of DOX-sensitive (MCF-7S and DOX-resistant (MCF-7R cells and reversed the resistance to DOX and vinorelbine. NCTD increased the intracellular accumulation of DOX in MCF-7R cells and suppressed the upregulated the mdr-1 mRNA, P-gp and BCRP protein expression, but not the MRP-1. The role of P-gp was strengthened by partial reversal of the DOX and vinorelbine resistance by cyclosporine A. NCTD treatment suppressed the upregulation of Shh expression and nuclear translocation of Gli-1, a hallmark of Shh signaling activation in the resistant clone. Furthermore, the Shh ligand upregulated the expression of P-gp and attenuated the growth inhibitory effect of NCTD. The knockdown of mdr-1 mRNA had not altered the expression of Shh and Smoothened in both MCF-7S and MCF-7R cells. This indicates that the role of Shh signaling in MDR might be upstream to mdr-1/P-gp, and similar effect was shown in breast cancer MDA-MB-231 and BT-474 cells. This study demonstrated that NCTD may overcome multidrug resistance through inhibiting Shh signaling and expression of its downstream mdr-1/P-gp expression in human breast cancer cells.

  16. An integrative genomic analysis revealed the relevance of microRNA and gene expression for drug-resistance in human breast cancer cells

    Directory of Open Access Journals (Sweden)

    Yamamoto Yusuke

    2011-11-01

    Full Text Available Abstract Background Acquisition of drug-resistance in cancer has led to treatment failure, however, their mechanisms have not been clarified yet. Recent observations indicated that aberrant expressed microRNA (miRNA caused by chromosomal alterations play a critical role in the initiation and progression of cancer. Here, we performed an integrated genomic analysis combined with array-based comparative hybridization, miRNA, and gene expression microarray to elucidate the mechanism of drug-resistance. Results Through genomic approaches in MCF7-ADR; a drug-resistant breast cancer cell line, our results reflect the unique features of drug-resistance, including MDR1 overexpression via genomic amplification and miRNA-mediated TP53INP1 down-regulation. Using a gain of function study with 12 miRNAs whose expressions were down-regulated and genome regions were deleted, we show that miR-505 is a novel tumor suppressive miRNA and inhibits cell proliferation by inducing apoptosis. We also find that Akt3, correlate inversely with miR-505, modulates drug sensitivity in MCF7-ADR. Conclusion These findings indicate that various genes and miRNAs orchestrate to temper the drug-resistance in cancer cells, and thus acquisition of drug-resistance is intricately controlled by genomic status, gene and miRNA expression changes.

  17. Silencing of ABCG2 by MicroRNA-3163 Inhibits Multidrug Resistance in Retinoblastoma Cancer Stem Cells.

    Science.gov (United States)

    Jia, Ming; Wei, Zhenhua; Liu, Peng; Zhao, Xiaoli

    2016-06-01

    To investigate the function and regulation mechanism of ATP-binding cassette, subfamily G, member 2 (ABCG2) in retinoblastoma cancer stem cells (RCSCs), a long-term culture of RCSCs from WERI-Rb1 cell line was successfully established based on the high expression level of ABCG2 on the surface of RCSCs. To further explore the molecular mechanism of ABCG2 on RCSCs, a microRNA that specifically targets ABCG2 was predicted. Subsequently, miR-3163 was selected and confirmed as the ABCG2-regulating microRNA. Overexpression of miR-3163 led to a significant decrease in ABCG2 expression. Additionally, ABCG2 loss-of-function induced anti-proliferation and apoptosis-promoting functions in RCSCs, and multidrug resistance to cisplatin, carboplatin, vincristine, doxorubicin, and etoposide was greatly improved in these cells. Our data suggest that miR-3163 has a significant impact on ABCG2 expression and can influence proliferation, apoptosis, and drug resistance in RCSCs. This work may provide new therapeutic targets for retinoblastoma. PMID:27247490

  18. HIF-1α inhibition reverses multidrug resistance in colon cancer cells via downregulation of MDR1/P-glycoprotein.

    Directory of Open Access Journals (Sweden)

    Jianfang Chen

    Full Text Available BACKGROUND: Multidrug resistance (MDR is one of the major reasons chemotherapy-based treatments fail. Hypoxia is generally associated with tumor chemoresistance. However, the correlation between the heterodimeric hypoxia-inducible factor-1 (HIF-1 and the multidrug resistance (MDR1 gene/transporter P-glycoprotein (P-gp remains unclear. This study aims to explore the molecular mechanisms of reversing colon cancer MDR by focusing on the target gene HIF-1α. METHODS: A chemotherapeutic sensitivity assay was used to observe the efficiency of MDR reversal in LoVo multicellular spheroids (MCS. The apoptotic level induced by different drugs was examined by flow cytometry (FCM. Binding of HIF-1α to the MDR1 gene promoter was evaluated by Chromatin immunoprecipitation (ChIP. The relationship between HIF-1α/P-gp expression and sensitivity to chemotherapy was analyzed. RESULTS: The sensitivity of LoVo MCS to all four chemotherapy drugs was decreased to varying degrees under hypoxic conditions. After silencing the HIF-1α gene, the sensitivities of LoVo MCS to all four chemotherapy drugs were restored. The apoptotic levels that all the drugs induced were all decreased to various extents in the hypoxic group. After silencing HIF-1α, the apoptosis level induced by all four chemotherapy drugs increased. The expression of HIF-1α and P-gp was significantly enhanced in LoVo MCS after treatment with hypoxia. Inhibiting HIF-1α significantly decreased the expression of MDR1/P-gp mRNA or protein in both the LoVo monolayers and LoVo MCS. The ChIP assay showed that HIF-1α was bound to the MDR1 gene promoter. Advanced colon carcinoma patients with expression of both HIF-1α and P-gp were more resistant to chemotherapy than that with non expression. CONCLUSIONS: HIF-1α inhibition reverses multidrug resistance in colon cancer cells via downregulation of MDR1/P-gp. The expression of HIF-1α and MDR1/P-gp can be used as a predictive marker for chemotherapy resistance

  19. Differences in cell cycle regulation after platinum derivatives treatment in sensitive and cisplatin resistant ovarian cancer cell lines

    Czech Academy of Sciences Publication Activity Database

    Horváth, Viktor; Souček, Karel; Šindlerová, Lenka; Hofmanová, Jiřina; Sova, Petr; Kozubík, Alois

    Quebec City, 2006. s. 133-133. [ISAC XXIII International Congress. 20.05.2006-24.05.2006, Québec City] R&D Projects: GA AV ČR(CZ) 1QS500040507; GA MPO(CZ) PZ-Z2/29 Institutional research plan: CEZ:AV0Z50040507 Keywords : cell cycle * ovarian cancer * cisplatin Subject RIV: BO - Biophysics

  20. 5,10b-Ethanophenanthridine amaryllidaceae alkaloids inspire the discovery of novel bicyclic ring systems with activity against drug resistant cancer cells.

    Science.gov (United States)

    Henry, Sean; Kidner, Ria; Reisenauer, Mary R; Magedov, Igor V; Kiss, Robert; Mathieu, Véronique; Lefranc, Florence; Dasari, Ramesh; Evidente, Antonio; Yu, Xiaojie; Ma, Xiuye; Pertsemlidis, Alexander; Cencic, Regina; Pelletier, Jerry; Cavazos, David A; Brenner, Andrew J; Aksenov, Alexander V; Rogelj, Snezna; Kornienko, Alexander; Frolova, Liliya V

    2016-09-14

    Plants of the Amaryllidaceae family produce a large variety of alkaloids and non-basic secondary metabolites, many of which are investigated for their promising anticancer activities. Of these, crinine-type alkaloids based on the 5,10b-ethanophenanthridine ring system were recently shown to be effective at inhibiting proliferation of cancer cells resistant to various pro-apoptotic stimuli and representing tumors with dismal prognoses refractory to current chemotherapy, such as glioma, melanoma, non-small-cell lung, esophageal, head and neck cancers, among others. Using this discovery as a starting point and taking advantage of a concise biomimetic route to the crinine skeleton, a collection of crinine analogues were synthetically prepared and evaluated against cancer cells. The compounds exhibited single-digit micromolar activities and retained this activity in a variety of drug-resistant cancer cell cultures. This investigation resulted in the discovery of new bicyclic ring systems with significant potential in the development of effective clinical cancer drugs capable of overcoming cancer chemotherapy resistance. PMID:27218860

  1. miR-17-5p Downregulation Contributes to Paclitaxel Resistance of Lung Cancer Cells through Altering Beclin1 Expression

    OpenAIRE

    Abhisek Chatterjee; Dhrubajyoti Chattopadhyay; Gopal Chakrabarti

    2014-01-01

    Non- small- cell lung cancer (NSCLC) is one of the most leading causes of cancer-related deaths worldwide. Paclitaxel based combination therapies have long been used as a standard treatment in aggressive NSCLCs. But paclitaxel resistance has emerged as a major clinical problem in combating non-small-cell lung cancer and autophagy is one of the important mechanisms involved in this phenomenon. In this study, we used microRNA (miRNA) arrays to screen differentially expressed miRNAs between pacl...

  2. Oxidative stress contributes to the tamoxifen-induced killing of breast cancer cells: implications for tamoxifen therapy and resistance

    OpenAIRE

    Bekele, Raie T.; Ganesh Venkatraman; Rong-Zong Liu; Xiaoyun Tang; Si Mi; Benesch, Matthew G. K.; Mackey, John R; Roseline Godbout; Curtis, Jonathan M.; McMullen, Todd P. W.; Brindley, David N.

    2016-01-01

    Tamoxifen is the accepted therapy for patients with estrogen receptor-α (ERα)-positive breast cancer. However, clinical resistance to tamoxifen, as demonstrated by recurrence or progression on therapy, is frequent and precedes death from metastases. To improve breast cancer treatment it is vital to understand the mechanisms that result in tamoxifen resistance. This study shows that concentrations of tamoxifen and its metabolites, which accumulate in tumors of patients, killed both ERα-positiv...

  3. Rejection of adenovirus infection is independent of coxsackie and adenovirus receptor expression in cisplatin-resistant human lung cancer cells.

    Science.gov (United States)

    Zhang, Nian-Hua; Peng, Rui-Qing; Ding, Ya; Zhang, Xiao-Shi

    2016-08-01

    The adenovirus vector-based cancer gene therapy is controversial. Low transduction efficacy is believed to be one of the main barriers for the decreased expression of coxsackie and adenovirus receptor (CAR) on tumor cells. However, the expression of CAR on primary tumor tissue and tumor tissue survived from treatment has still been not extensively studied. The present study analyzed the adenovirus infection rates and CAR expression in human lung adenocarcinoma cell line A549 and its cisplatin-resistant subline A549/DDP. The results showed that although the CAR expression in A549 and A549/DDP was not different, compared with the A549, A549/DDP appeared obviously to reject adenovirus infection. Moreover, we modified CAR expression in the two cell lines with proteasome inhibitor MG-132 and histone deacetylase inhibitor trichostatin A (TSA), and analyzed the adenovirus infection rates after modifying agent treatments. Both TSA and MG-132 pretreatments could increase the CAR expression in the two cell lines, but the drug pretreatments could only make A549 cells more susceptible to adenovirus infectivity. PMID:27373420

  4. Binding and inhibition of drug transport proteins by heparin: a potential drug transporter modulator capable of reducing multidrug resistance in human cancer cells.

    Science.gov (United States)

    Chen, Yunliang; Scully, Michael; Petralia, Gloria; Kakkar, Ajay

    2014-01-01

    A major problem in cancer treatment is the development of resistance to chemotherapeutic agents, multidrug resistance (MDR), associated with increased activity of transmembrane drug transporter proteins which impair cytotoxic treatment by rapidly removing the drugs from the targeted cells. Previously, it has been shown that heparin treatment of cancer patients undergoing chemotherapy increases survival. In order to determine whether heparin is capable reducing MDR and increasing the potency of chemotherapeutic drugs, the cytoxicity of a number of agents toward four cancer cell lines (a human enriched breast cancer stem cell line, two human breast cancer cell lines, MCF-7 and MDA-MB-231, and a human lung cancer cell line A549) was tested in the presence or absence of heparin. Results demonstrated that heparin increased the cytotoxicity of a range of chemotherapeutic agents. This effect was associated with the ability of heparin to bind to several of the drug transport proteins of the ABC and non ABC transporter systems. Among the ABC system, heparin treatment caused significant inhibition of the ATPase activity of ABCG2 and ABCC1, and of the efflux function observed as enhanced intracellular accumulation of specific substrates. Doxorubicin cytoxicity, which was enhanced by heparin treatment of MCF-7 cells, was found to be under the control of one of the major non-ABC transporter proteins, lung resistance protein (LRP). LRP was also shown to be a heparin-binding protein. These findings indicate that heparin has a potential role in the clinic as a drug transporter modulator to reduce multidrug resistance in cancer patients. PMID:24253450

  5. l-carnosine dipeptide overcomes acquired resistance to 5-fluorouracil in HT29 human colon cancer cells via downregulation of HIF1-alpha and induction of apoptosis.

    Science.gov (United States)

    Iovine, Barbara; Guardia, Francesca; Irace, Carlo; Bevilacqua, Maria Assunta

    2016-08-01

    Hypoxia-inducible factor (HIF-1α) protein is over-expressed in many human cancers and is a major cause of resistance to drugs. HIF-1α up-regulation decreases the effectiveness of several anticancer agents, including 5-fluorouracil (5-FU), because it induces the expression of drug efflux transporters, alters DNA repair mechanisms and modifies the balance between pro- and antiapoptotic factors. These findings suggest that inhibition of HIF-1α activity may sensitize cancer cells to cytotoxic drugs. We previously reported that l-carnosine reduces HIF-1α expression by inhibiting the proliferation of colon cancer cells. In the present study we investigated the effect of l-carnosine on HT29 colon cancer cells with acquired resistance to 5-FU. We found that l-carnosine reduces colon cancer cell viability, decreases HIF-1α and multi-drug resistant protein MDR1-pg expression, and induces apoptosis. Moreover, the l-carnosine/5-FU combination lowers the expression of some chemoresistance markers. The combination index evaluated in vitro on the HT29-5FU cell line by median drug effect analysis reveals a significant synergistic effect. PMID:27234614

  6. REVERSAL EFFECTS OF MIFEPRISTONE ON MULTIDRUG RESISTANCE(MDR) IN DRUG-RESISTANT BREAST CANCER CELL LINE MCF7/ADR IN VITRO AND IN VIVO

    Institute of Scientific and Technical Information of China (English)

    李大强; 潘丽华; 邵志敏

    2004-01-01

    Objective: To explore the reversal effect of mifepristone on multidrug resistance (MDR) in drug-resistant human breast cancer cell line MCF7/ADR and its mechanisms. Methods: Expression of MDR1 and MDR-associated protein(MRP) mRNA in MCF7/ADR cells was detected using reverse transcription- polymerase chain reaction(RT-PCR). Western blotting was used to assay the protein levels of P-glycoprotein (P-gp) and MRP. Intracellular rhodamine 123 retention and [3H]vincristine (VCR) accumulation were measured by flow cytometry and liquid scintillation counter, respectively. MTT reduction assay was used to determine the sensitivity of cells to the anticancer agent, adriamycin (ADR). Additionally, a MCF7/ADR cell xenograft model was established to assess the reversal effect of mifeprisone on MDR in MCF7/ADR cells in vivo. Results: Miferpristone dose-dependently down- regulated the expression of MDR1 and MRP mRNA in MCF7/ADR cells, accompanied by a significant decrease in the protein levels of P-gp and MRP. After exposure to 5, 10, and 20 μmol/L mifepristone, MCF7/ADR cells showed a 3.87-, 5.81-, and 7.40-fold increase in the accumulation of intracellular VCR(a known substrate of MRP), and a 2.14-, 4.39-, and 5.53-fold increase in the retention of intracellular rhodamine 123(an indicator of P-gp function), respectively. MTT analysis showed that the sensitivity of MCF7/ADR cells to ADR was enhanced by 7.23-, 13.62-, and 20.96-fold after incubation with mifepristone as above-mentioned doses for 96 h. In vivo, mifepristone effectively restored the chemosensitivity of MCF7/ADR cells to ADR. After 8 weeks of administration with ADR(2 mg·kg-1·d-1) alone or in combination with mifepristone(50 mg·kg-1·d-1), the growth inhibitory rate of xenografted tumors in nude mice was 8.08% and 37.25%, respectively. Conclusion: Mifepristone exerts potent reversal effects on MDR in MCF7/ADR cells in vitro and in vivo through down- regulation of MDR1/P-gp and MRP expression and inhibition of P

  7. New advances on critical implications of tumor- and metastasis-initiating cells in cancer progression, treatment resistance and disease recurrence

    OpenAIRE

    Mimeault, M; Batra, Surinder K.

    2010-01-01

    Accumulating lines of experimental evidence have revealed that the malignant transformation of multipotent tissue-resident adult stem/progenitor cells into cancer stem/progenitor cells endowed with a high self-renewal capacity and aberrant multilineage differentiation potential may be at origin of the most types of human aggressive and recurrent cancers. Based on new cancer stem/progenitor cell concepts of carcinogenesis, it is suggested that a small subpopulation of highly tumorigenic and mi...

  8. A Systemic Review of Resistance Mechanisms and Ongoing Clinical Trials in ALK-rearranged Non-Small Cell Lung Cancer

    Directory of Open Access Journals (Sweden)

    VictorCohen

    2014-07-01

    Full Text Available The identification of oncogenic driver driver mutations in non-small cell lung cancer has led to a paradigm shift and the development of specific molecular treatments. Tumors harboring a rearranged EML4-ALK fusion oncogene are highly sensitive to therapy with ALK-targeted inhibitors. Crizotinib is the first approved treatment for advanced lung tumors containing this genetic abnormality. In this mini review, we discuss the existing data on crizotinib as well as ongoing trials involving this medication. A brief overview of the known resistance mechanisms to criztotinib will also be presented followed by a summary of the ongoing trials involving next-generation ALK inhibitors or other targeted therapies in patients with ALK+ NSCLC.

  9. Tamoxifen Resistance in Breast Cancer

    OpenAIRE

    Chang, Minsun

    2012-01-01

    Tamoxifen is a central component of the treatment of estrogen receptor (ER)-positive breast cancer as a partial agonist of ER. It has been clinically used for the last 30 years and is currently available as a chemopreventive agent in women with high risk for breast cancer. The most challenging issue with tamoxifen use is the development of resistance in an initially responsive breast tumor. This review summarizes the roles of ER as the therapeutic target of tamoxifen in cancer treatment, clin...

  10. Activating Transcription Factor 4 Confers a Multidrug Resistance Phenotype to Gastric Cancer Cells through Transactivation of SIRT1 Expression

    OpenAIRE

    Hongwu Zhu; Limin Xia; Yongguo Zhang; Honghong Wang; Wenjing Xu; Hao Hu; Jing Wang; Jing Xin; Yi Gang; Sumei Sha; Bin Xu; Daiming Fan; Yongzhan Nie; Kaichun Wu

    2012-01-01

    BACKGROUND: Multidrug resistance (MDR) in gastric cancer remains a major challenge to clinical treatment. Activating transcription factor 4 (ATF4) is a stress response gene involved in homeostasis and cellular protection. However, the expression and function of ATF4 in gastric cancer MDR remains unknown. In this study, we investigate whether ATF4 play a role in gastric cancer MDR and its potential mechanisms. METHODOLOGY/PRINCIPAL FINDINGS: We demonstrated that ATF4 overexpression confered th...

  11. Resistance to ursolic acid-induced apoptosis through involvement of melanogenesis and COX-2/PGE2 pathways in human M4Beu melanoma cancer cells.

    Science.gov (United States)

    Hassan, Lama; Pinon, Aline; Limami, Youness; Seeman, Josiane; Fidanzi-Dugas, Chloe; Martin, Frederique; Badran, Bassam; Simon, Alain; Liagre, Bertrand

    2016-07-01

    Melanoma is one of the most aggressive forms of cancer with a continuously growing incidence worldwide and is usually resistant to chemotherapy agents, which is due in part to a strong resistance to apoptosis. Previously, we had showed that B16-F0 murine melanoma cells undergoing apoptosis are able to delay their own death induced by ursolic acid (UA), a natural pentacyclic triterpenoid compound. We had demonstrated that tyrosinase and TRP-1 up-regulation in apoptotic cells and the subsequent production of melanin were implicated in an apoptosis resistance mechanism. Several resistance mechanisms to apoptosis have been characterized in melanoma such as hyperactivation of DNA repair mechanisms, drug efflux systems, and reinforcement of survival signals (PI3K/Akt, NF-κB and Raf/MAPK pathways). Otherwise, other mechanisms of apoptosis resistance involving different proteins, such as cyclooxygenase-2 (COX-2), have been described in many cancer types. By using a strategy of specific inhibition of each ways, we suggested that there was an interaction between melanogenesis and COX-2/PGE2 pathway. This was characterized by analyzing the COX-2 expression and activity, the expression of tyrosinase and melanin production. Furthermore, we showed that anti-proliferative and proapoptotic effects of UA were mediated through modulation of multiple signaling pathways including Akt and ERK-1/2 proteins. Our study not only uncovers underlying molecular mechanisms of UA action in human melanoma cancer cells but also suggest its great potential as an adjuvant in treatment and cancer prevention. PMID:27262506

  12. P-glycoprotein-mediated resistance to chemotherapy in cancer cells: using recombinant cytosolic domains to establish structure-function relationships

    Directory of Open Access Journals (Sweden)

    Di Pietro A.

    1999-01-01

    Full Text Available Resistance to chemotherapy in cancer cells is mainly mediated by overexpression of P-glycoprotein (Pgp, a plasma membrane ATP-binding cassette (ABC transporter which extrudes cytotoxic drugs at the expense of ATP hydrolysis. Pgp consists of two homologous halves each containing a transmembrane domain and a cytosolic nucleotide-binding domain (NBD which contains two consensus Walker motifs, A and B, involved in ATP binding and hydrolysis. The protein also contains an S signature characteristic of ABC transporters. The molecular mechanism of Pgp-mediated drug transport is not known. Since the transporter has an extraordinarily broad substrate specificity, its cellular function has been described as a "hydrophobic vacuum cleaner". The limited knowledge about the mechanism of Pgp, partly due to the lack of a high-resolution structure, is well reflected in the failure to efficiently inhibit its activity in cancer cells and thus to reverse multidrug resistance (MDR. In contrast to the difficulties encountered when studying the full-length Pgp, the recombinant NBDs can be obtained in large amounts as soluble proteins. The biochemical and biophysical characterization of recombinant NBDs is shown here to provide a suitable alternative route to establish structure-function relationships. NBDs were shown to bind ATP and analogues as well as potent modulators of MDR, such as hydrophobic steroids, at a region close to the ATP site. Interestingly, flavonoids also bind to NBDs with high affinity. Their binding site partly overlaps both the ATP-binding site and the steroid-interacting region. Therefore flavonoids constitute a new promising class of bifunctional modulators of Pgp.

  13. NFkB signaling is important for growth of antiestrogen resistant breast cancer cells

    DEFF Research Database (Denmark)

    Yde, Christina Westmose; Emdal, Kristina Bennet; Guerra, Barbara; Lykkesfeldt, Anne E

    2012-01-01

    compared to the parental cell line. Inhibition of NF¿B signaling sensitized tamoxifen resistant cells to the growth inhibitory effects of tamoxifen but was not sufficient to fully restore sensitivity of fulvestrant resistant cells to fulvestrant. In support of this, depletion of p65 with siRNA in tamoxifen...

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

    Directory of Open Access Journals (Sweden)

    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.

  15. Reversing multidrug resistance in breast cancer cells by silencing ABC transporter genes with nanoparticle-facilitated delivery of target siRNAs

    Directory of Open Access Journals (Sweden)

    Li YT

    2012-06-01

    Full Text Available Yong Tsuey Li,1 Ming Jang Chua,1 Anil Philip Kunnath,1 Ezharul Hoque Chowdhury,1,21Faculty of Medicine and Health Science, International Medical University (IMU, No 126, Jalan 19/155B, Bukit Jalil, 57000 Kuala Lumpur, Malaysia; 2Jeffrey Cheah School of Medicine and Health Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University Kuala Lumpur, MalaysiaBackground: Multidrug resistance, a major impediment to successful cancer chemotherapy, is the result of overexpression of ATP-binding cassette (ABC transporters extruding internalized drugs. Silencing of ABC transporter gene expression with small interfering RNA (siRNA could be an attractive approach to overcome multidrug resistance of cancer, although delivery of siRNA remains a major hurdle to fully exploit the potential of siRNA-based therapeutics. Recently, we have developed pH-sensitive carbonate apatite nanoparticles to efficiently carry and transport siRNA across the cell membrane, enabling knockdown of the cyclin B1 gene and consequential induction of apoptosis in synergy with anti-cancer drugs.Methods and results: We report that carbonate apatite-mediated delivery of the siRNAs targeting ABCG2 and ABCB1 gene transcripts in human breast cancer cells which constitutively express both of the transporter genes dose-dependently enhanced chemosensitivity to doxorubicin, paclitaxel and cisplatin, the traditionally used chemotherapeutic agents. Moreover, codelivery of two specific siRNAs targeting ABCB1 and ABCG2 transcripts resulted in a more robust increase of chemosensitivity in the cancer cells, indicating the reversal of ABC transporter-mediated multidrug resistance.Conclusion: The delivery concept of multiple siRNAs against ABC transporter genes is highly promising for preclinical and clinical investigation in reversing the multidrug resistance phenotype of breast cancer.Keywords: carbonate apatite, siRNA, gene expression, transfection, breast cancer, ABC transporter

  16. Theaflavin-3, 3'-digallate induces apoptosis and G2 cell cycle arrest through the Akt/MDM2/p53 pathway in cisplatin-resistant ovarian cancer A2780/CP70 cells.

    Science.gov (United States)

    Tu, Youying; Kim, Eunhye; Gao, Ying; Rankin, Gary O; Li, Bo; Chen, Yi Charlie

    2016-06-01

    Ovarian cancer is the most lethal gynecological cancer among women worldwide. Adverse side effects and acquired resistance to conventional platinum based chemotherapy are major impediments in ovarian cancer treatment, and drive the development of more selective anticancer drugs that target cancer-specific defects. In this study, theaflavin-3, 3'-digallate (TF3), the major theaflavin monomer in black tea, exhibited a potent growth inhibitory effect on the cisplatin-resistant ovarian cancer A2780/CP70 cells (IC50, 23.81 µM), and was less cytotoxic to a normal ovarian IOSE‑364 cells (IC50, 59.58 µM) than to the cancer cells. Flow cytometry analysis indicated that TF3 induced preferential apoptosis and G2 cell cycle arrest in A2780/CP70 cells with respect to IOSE‑364 cells. TF3 induced apoptosis through both the intrinsic and extrinsic apoptotic pathways, and caused G2 cell cycle arrest via cyclin B1 in A2780/CP70 cells. The p53 protein played an important role in TF3-induced apoptosis and G2 cell cycle arrest. TF3 might upregulate the p53 expression via the Akt/MDM2 pathway. Our findings help elucidate the mechanisms by which TF3 may contribute to the prevention and treatment of platinum-resistant ovarian cancer. PMID:27082635

  17. Epithelial-Mesenchymal Transitions and the Expression of Twist in MCF-7/ADR,Human Multidrug-Resistant Breast Cancer Cells

    Institute of Scientific and Technical Information of China (English)

    Fei Zhang; Yurong Shi; Lin Zhang; Bin Zhang; Xiyin Wei; Yi Yang; RUi Wang; Ruifang Niu

    2007-01-01

    OBJECTIVE To study the expression levels of Twist and epithelialmesenchymal transitions in multidrug-resistant MCF-7/ADR breast cancer cells,and to study the relationship between multidrug resistance (MDR) and metastatic potential of the cells.METHODS RT-PCR,immunohislochemical and Western blotting methods were used to examine the changes of expression levels of the transcription factor Twist.E-cadherin and N-cadherin in the MCF-7 breast cancer cell line and its multidrug-resistant variant.MCF-7/ADR.RESULTS In MCF-7 cells,the expression of E-cadherin can be detected,but there is no expression of Twisl or N-cadherin.In MCF-7/ADR cells,E-cadherin expression is lost.bul the expression of two other genes was significantly positive.CONCLUSION Epithelial-mesenchymal transitions induced by Twist,may have a relationship with enhanced invasion and metastatic potential during the development of multidrug-resistant MCF-7/ADR breast cancer cells.

  18. Differences in cell cycle regulation after platinum derivatives treatment in sensitive and cisplatin resistant ovarian cancer cell lines

    Czech Academy of Sciences Publication Activity Database

    Horváth, Viktor; Souček, Karel; Šindlerová, Lenka; Hofmanová, Jiřina; Sova, P.; Kozubík, Alois

    2006-01-01

    Roč. 100, č. 5 (2006), s. 383-384. ISSN 0009-2770. [Mezioborové setkání mladých biologů, biochemiků a chemiků /6./. 14.06.2006-17.06.2006, Milovy] R&D Projects: GA AV ČR(CZ) 1QS500040507; GA MPO(CZ) PZ-Z2/29 Institutional research plan: CEZ:AV0Z50040507 Keywords : ovarian cancer * cell cycle * cisplatin Subject RIV: BO - Biophysics

  19. Squamous cell skin cancer

    Science.gov (United States)

    ... earliest form of squamous cell cancer is called Bowen disease (or squamous cell carcinoma in situ). This type ... cancer; Squamous cell carcinoma of the skin Images Bowen's disease on the hand Keratoacanthoma Keratoacanthoma Skin cancer, squamous ...

  20. p38 MAPK-induced MDM2 degradation confers paclitaxel resistance through p53-mediated regulation of EGFR in human lung cancer cells

    Science.gov (United States)

    Park, Shin-Hyung; Seong, Myeong-A; Lee, Ho-Young

    2016-01-01

    Paclitaxel (PTX) is a chemotherapeutic agent that is used to treat a variety of cancers, including non-small cell lung cancer (NSCLC). However, the emergence of drug resistance limits the utility of PTX. This study determined the signaling pathway that contributes to PTX resistance. We first established PTX resistant cell lines (H460/R and 226B/R) using a dose-escalating maintenance of PTX. We found that p38 MAPK and epidermal growth factor receptor (EGFR) were constitutively activated in these cell lines. The inhibition of p38 MAPK activity by SB203580 treatment or the transfection of dominant-negative p38 MAPK sensitized both cell lines to PTX treatment. Erlotinib, an EGFR inhibitor, also increased PTX-induced apoptosis in PTX resistant cells, which suggests a role for p38 MAPK and EGFR in the development of PTX resistance. We demonstrated that p38 MAPK enhanced EGFR expression via the induction of the rapid degradation of mouse double-minute 2 homolog (MDM2) and the consequent stabilization of p53, a transcription factor of EGFR. These results suggest for the first time that the p38 MAPK/p53/EGFR axis is crucial for the facilitation of PTX resistance in NSCLCs. We also propose a mechanism for the role of the tumor-suppressor p53 in drug resistance. These results provide a foundation for the future development of potential therapeutic strategies to regulate the p38 MAPK/p53/EGFR pathway for the treatment of lung cancer patients with PTX resistance. PMID:26799187

  1. Acquired cisplatin resistance in human ovarian A2780 cancer cells correlates with shift in taurine homeostasis and ability to volume regulate

    DEFF Research Database (Denmark)

    Sørensen, Belinda Halling; Thorsteinsdottir, Unnur Arna; Lambert, Ian Henry

    2014-01-01

    Cisplatin resistance is a major challenge in the treatment of cancer and develops through reduced drug accumulation and an increased ability to avoid drug-induced cell damage, cell shrinkage, and hence initiation of apoptosis. Uptake and release of the semiessential amino acid taurine contribute to...... cell volume homeostasis, and taurine has been reported to have antiapoptotic effects. Here we find that volume-sensitive taurine release in cisplatin-sensitive [wild-type (WT)] human ovarian cancer A2780 cells is reduced in the presence of the phospholipase A2 inhibitor bromenol lactone, the 5......-induced cell death in RES A2780 cells correlates with an increased accumulation of taurine, due to an increased taurine uptake and a concomitant impairment of the volume-sensitive taurine release pathway, as well an inability to reduce cell volume after osmotic cell swelling. Downregulation of volume...

  2. INPP4B-mediated tumor resistance is associated with modulation of glucose metabolism via hexokinase 2 regulation in laryngeal cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Min, Joong Won [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Kim, Kwang Il [Molecular Imaging Research Center, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Kim, Hyun-Ah; Kim, Eun-Kyu; Noh, Woo Chul [Department of Surgery, Korea Cancer Center Hospital, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Jeon, Hong Bae [Biomedical Research Institute, MEDIPOST Co., Ltd., Seoul (Korea, Republic of); Cho, Dong-Hyung [Graduate School of East-West Medical Science, Kyung Hee University, Gyeonggi-do (Korea, Republic of); Oh, Jeong Su [Department of Genetic Engineering, Sungkyunkwan University, Suwon (Korea, Republic of); Park, In-Chul; Hwang, Sang-Gu [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Kim, Jae-Sung, E-mail: jaesung@kirams.re.kr [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2013-10-11

    Highlights: •HIF-1α-regulated INPP4B enhances glycolysis. •INPP4B regulates aerobic glycolysis by inducing HK2 via Akt-mTOR pathway. •Blockage of INPP4B and HK2 sensitizes radioresistant laryngeal cancer cells to radiation and anticancer drug. •INPP4B is associated with HK2 in human laryngeal cancer tissues. -- Abstract: Inositol polyphosphate 4-phosphatase type II (INPP4B) was recently identified as a tumor resistance factor in laryngeal cancer cells. Herein, we show that INPP4B-mediated resistance is associated with increased glycolytic phenotype. INPP4B expression was induced by hypoxia and irradiation. Intriguingly, overexpression of INPP4B enhanced aerobic glycolysis. Of the glycolysis-regulatory genes, hexokinase 2 (HK2) was mainly regulated by INPP4B and this regulation was mediated through the Akt-mTOR pathway. Notably, codepletion of INPP4B and HK2 markedly sensitized radioresistant laryngeal cancer cells to irradiation or anticancer drug. Moreover, INPP4B was significantly associated with HK2 in human laryngeal cancer tissues. Therefore, these results suggest that INPP4B modulates aerobic glycolysis via HK2 regulation in radioresistant laryngeal cancer cells.

  3. Targeting Signal Pathways active in Cancer Stem Cells to Overcome Drug Resistance

    Institute of Scientific and Technical Information of China (English)

    Miaorong SHE; Xilin CHEN

    2009-01-01

    @@ 1 Introduction Over the last several decades, although there have been advances in the treatment of diseases such as children leuke-mia, Hodgkin's disease, and testicular cancer, however, the survival of patients with the most common malignancies such as lung, breast, liver, and colon cancers has not changed signifi-cantly[1-4].

  4. Neuropilin 1 expression correlates with the Radio-resistance of human non-small-cell lung cancer cells.

    Science.gov (United States)

    Dong, Juan Cong; Gao, Hui; Zuo, Si Yao; Zhang, Hai Qin; Zhao, Gang; Sun, Shi Long; Han, Hai Ling; Jin, Lin Lin; Shao, Li Hong; Wei, Wei; Jin, Shun Zi

    2015-09-01

    The purpose of this study was to determine the correlation between over-expression of the neuropilin 1 (NRP1) gene and growth, survival, and radio-sensitivity of non-small cell lung carcinoma (NSCLC) cells. 3-[4,5-dimethylthylthiazol-2-yl]-2,5 diphenyltetrazolium broide (MTT) and colony assays were then performed to determine the effect of NRP1 inhibition on the in vitro growth of NSCLC cells. The Annexin V-Fluorescein Isothiocyanate (FITC) apoptosis detection assay was performed to analyse the effect of NRP1 enhancement on apoptosis of NSCLC cells. Transwell invasion and migration assays were employed to examine the metastatic ability of A549 cells post X-ray irradiation. In addition, Western blot assays were carried out to detect the protein level of VEGFR2, PI3K and NF-κB. Finally, to examine the effect of shNRP1 on proliferation and radio-sensitivity in vivo, a subcutaneous tumour formation assay in nude mice was performed. Microvessel density in tumour tissues was assessed by immunohistochemistry. The stable transfected cell line (shNRP1-A549) showed a significant reduction in colony-forming ability and proliferation not only in vitro, but also in vivo. Moreover, shRNA-mediated NRP1 inhibition also significantly enhanced the radio-sensitivity of NSCLC cells both in vitro and in vivo. The over-expression of NRP1 was correlated with growth, survival and radio-resistance of NSCLC cells via the VEGF-PI3K- NF-κB pathway, and NRP1 may be a molecular therapeutic target for gene therapy or radio-sensitization of NSCLC. PMID:26147006

  5. Resistance to bleomycin in cancer cell lines is characterized by prolonged doubling time, reduced DNA damage and evasion of G2/M arrest and apoptosis.

    Directory of Open Access Journals (Sweden)

    Qi Wang

    Full Text Available BACKGROUND: To establish, characterize and elucidate potential mechanisms of acquired bleomycin (BLM resistance using human cancer cell lines. Seven BLM-resistant cell lines were established by exposure to escalating BLM concentrations over a period of 16-24 months. IC50 values and cell doubling times were quantified using a real time cytotoxicity assay. COMET and γ-H2AX assays, cell cycle analysis, and apoptosis assessment further investigated the mechanisms of BLM resistance in these cell lines. RESULTS: Compared with parental cell lines, real time cytotoxicity assays revealed 7 to 49 fold increases in IC50 and a mean doubling time increase of 147 % (range 64 %-352% in BLM-resistant sub-clones (p<0.05 for both. Higher maintenance BLM concentrations were associated with higher IC50 and increased doubling times (p<0.05. Significantly reduced DNA damage (COMET and γ-H2AX assays, G2/M arrest, and apoptosis (p<0.05 for each set of comparison following high-dose acute BLM exposure was observed in resistant sub-clones, compared with their BLM-sensitive parental counterparts. Three weeks of BLM-free culturing resulted in a partial return to BLM sensitivity in 3/7 BLM-resistant sub-clones (p<0.05. CONCLUSION: Bleomycin resistance may be associated with reduced DNA damage after bleomycin exposure, resulting in reduced G2/M arrest, and reduced apoptosis.

  6. Modulation of septin and molecular motor recruitment in the microtubule environment of the Taxol-resistant human breast cancer cell line MDA-MB-231.

    Science.gov (United States)

    Froidevaux-Klipfel, Laurence; Poirier, Florence; Boursier, Céline; Crépin, Ronan; Poüs, Christian; Baudin, Bruno; Baillet, Anita

    2011-10-01

    Cell resistance to low doses of paclitaxel (Taxol) involves a modulation of microtubule (MT) dynamics. We applied a proteomic approach based on 2-DE coupled with MS to identify changes in the MT environment of Taxol-resistant breast cancer cells. Having established a proteomic pattern of the microtubular proteins extracted from MDA-MB-231 cells, we verified by Western blotting that in resistant cells, α- and β-tubulins (more specifically the βIII and βIV isotypes) increased. Interestingly, four septins (SEPT2, 8, 9 and 11), which are GTPases involved in cytokinesis and in MT/actin cytoskeleton organization, were overexpressed and enriched in the MT environment of Taxol-resistant cells compared to their sensitive counterpart. Changes in the MT proteome of resistant cells also comprised increased kinesin-1 heavy chain expression and recruitment on MTs while dynein light chain-1 was downregulated. Modulation of motor protein recruitment around MTs might reflect their important role in controlling MT dynamics via the organization of signaling pathways. The identification of proteins previously unknown to be linked to taxane-resistance could also be valuable to identify new biological markers of resistance. PMID:21761557

  7. Synthetic and Biological Studies of Sesquiterpene Polygodial: Activity of 9-Epipolygodial against Drug-Resistant Cancer Cells.

    Science.gov (United States)

    Dasari, Ramesh; De Carvalho, Annelise; Medellin, Derek C; Middleton, Kelsey N; Hague, Frédéric; Volmar, Marie N M; Frolova, Liliya V; Rossato, Mateus F; De La Chapa, Jorge J; Dybdal-Hargreaves, Nicholas F; Pillai, Akshita; Mathieu, Véronique; Rogelj, Snezna; Gonzales, Cara B; Calixto, João B; Evidente, Antonio; Gautier, Mathieu; Munirathinam, Gnanasekar; Glass, Rainer; Burth, Patricia; Pelly, Stephen C; van Otterlo, Willem A L; Kiss, Robert; Kornienko, Alexander

    2015-12-01

    Polygodial, a terpenoid dialdehyde isolated from Polygonum hydropiper L., is a known agonist of the transient receptor potential vanilloid 1 (TRPV1). In this investigation a series of polygodial analogues were prepared and investigated for TRPV1-agonist and anticancer activities. These experiments led to the identification of 9-epipolygodial, which has antiproliferative potency significantly exceeding that of polygodial. 9-Epipolygodial was found to maintain potency against apoptosis-resistant cancer cells as well as those displaying the multidrug-resistant (MDR) phenotype. In addition, the chemical feasibility for the previously proposed mechanism of action of polygodial, involving the formation of a Paal-Knorr pyrrole with a lysine residue on the target protein, was demonstrated by the synthesis of a stable polygodial pyrrole derivative. These studies reveal rich chemical and biological properties associated with polygodial and its direct derivatives. These compounds should inspire further work in this area aimed at the development of new pharmacological agents, or the exploration of novel mechanisms of covalent modification of biological molecules with natural products. PMID:26434977

  8. Advances in the management of acquired resistance to EGFR-TKI in non-small cell lung cancer

    Institute of Scientific and Technical Information of China (English)

    Fei Zhou; Caicun Zhou

    2015-01-01

    Drugs that specifical y target the tyrosine kinase domain of epidermal growth factor receptor (EGFR), such as erlotinib or gefitinib, have exhibited striking ef icacy in non-smal cel lung cancer (NSCLC) patients har-boring activating EGFR mutations. However, acquired resistance inevitably develops and remains a serious barrier for the successful management of patients with this disease. Multiple mechanisms are reportedly involved in the process of acquired resistance, which provide new insights into the management of EGFR-tyrosine kinase inhibitor (EGFR-TKI) resistance. Here, we provide an overview of the emerging treatment approaches for patients with EGFR-TKI resistance.

  9. Acquisition of docetaxel resistance in breast cancer cells reveals upregulation of ABCB1 expression as a key mediator of resistance accompanied by discrete upregulation of other specific genes and pathways

    DEFF Research Database (Denmark)

    Ninel Hansen, Stine; Westergaard, David; Borg Houlberg Thomsen, Mathilde;

    2015-01-01

    analysis singled out ABCB1, which encodes permeability glycoprotein (Pgp), as the top upregulated gene in both MCF7RES and MDARES. Functional validation revealed Pgp as a key resistance mediator at low docetaxel concentrations (first-phase response), whereas additional resistance mechanisms appeared to be...... resistance and thereby identify key molecular mechanisms and predictive molecular characteristics to docetaxel resistance. Two docetaxel-resistant cell lines, MCF7RES and MDARES, were generated from their respective parental cell lines MCF-7 and MDA-MB-231 by stepwise selection in docetaxel dose increments...... prominent at higher docetaxel concentrations (second-phase response). Additional resistance mechanisms were indicated by gene expression profiling, including genes in the interferon-inducible protein family in MCF7RES and cancer testis antigen family in MDARES. Also, upregulated expression of various ABC...

  10. The role of NAD(P)H:quinone oxidoreductase in mitomycin C- and porfiromycin-resistant HCT 116 human colon-cancer cells.

    Science.gov (United States)

    Pan, S S; Akman, S A; Forrest, G L; Hipsher, C; Johnson, R

    1992-01-01

    A mitomycin C (MMC)- and porfiromycin (PFM)-resistant subline of the HCT 116 human colon-cancer cell line was isolated after repeated exposure of HCT 116 cells to increasing concentrations of MMC under aerobic conditions. The MMC-resistant subline (designated HCT 116-R30A) was 5 times more resistant than the parent cells to MMC and PFM under aerobic conditions. Both the MMC-resistant cells and the parent HCT 116 cells accumulated similar amounts of PFM by passive diffusion, but levels of macromolecule-bound PFM were about 50% lower in the resistant cell line, implying a decrease in PFM reductive activation in the resistant cells. The finding that microsomes from either sensitive or resistant cells showed an equal ability to reduce MMC and PFM indicated that the activity of NADPH cytochrome P-450 reductase (EC 1.6.2.4) was not changed in the resistant subline. Soluble extracts of HCT 116 cells reduced MMC and PFM more effectively at pH 6.1, and NADH and NADPH were utilized equally well as electron donors under both aerobic and anaerobic conditions. These data suggest that quinone reductase (EC 1.6.99.2; DT-diaphorase) in soluble extracts is responsible for the reduction of MMC. Quinone reductase activities in soluble extracts of HCT 116-R30A cells for the reduction of dichlorophenol indophenol (DCPIP) and menadione-cytochrome c at optimal pHs were decreased by 95% as compared with those obtained in parent cells. However, the MMC-reducing activity of HCT 116-R30A soluble extracts was only 50% lower than that of the parent cell extracts. The kinetic constants (Km, Vmax) found for quinone reductase in the two cell lines with respect to the substrates DCPIP and menadione differed. Two species of mRNA for quinone reductase (2.7 and 1.2 kb) were detected in both cell lines, and there was no detectable difference between parent and resistant cells in the steady-state level of either of these mRNA species. Furthermore, incubation with the quinone reductase inhibitor

  11. Parallel Evolution under Chemotherapy Pressure in 29 Breast Cancer Cell Lines Results in Dissimilar Mechanisms of Resistance

    DEFF Research Database (Denmark)

    Tegze, Balint; Szallasi, Zoltan Imre; Haltrich, Iren;

    2012-01-01

    previous studies by parallel developing a massive number of cell lines to investigate chemoresistance. While the heterogeneity caused evolution of multiple resistant clones with different resistance characteristics, the activation of only a few mechanisms were sufficient in one cell line to achieve...

  12. The Hippo Pathway Effector YAP Regulates Motility, Invasion, and Castration-Resistant Growth of Prostate Cancer Cells

    OpenAIRE

    Lin ZHANG; Yang, Shuping; Chen, Xingcheng; Stauffer, Seth; Yu, Fang; Lele, Subodh M.; Fu, Kai; Datta, Kaustubh; Palermo, Nicholas; Chen, Yuanhong; Dong, Jixin

    2015-01-01

    Yes-associated protein (YAP) is an effector of the Hippo tumor suppressor pathway. The functional significance of YAP in prostate cancer has remained elusive. In this study, we first show that enhanced expression of YAP is able to transform immortalized prostate epithelial cells and promote migration and invasion in both immortalized and cancerous prostate cells. We found that YAP mRNA was upregulated in androgen-insensitive prostate cancer cells (LNCaP-C81 and LNCaP-C4-2 cells) compared to t...

  13. Bcl-xL and Myeloid cell leukaemia-1 contribute to apoptosis resistance of colorectal cancer cells

    Institute of Scientific and Technical Information of China (English)

    Henning Schulze-Bergkamen; Steffen Heeger; Peter R Galle; Markus Moehler; Roland Ehrenberg; Lothar Hickmann; Binje Vick; Toni Urbanik; Christoph C Schimanski; Martin R Berger; Arno Schad; Achim Weber

    2008-01-01

    AIM: To explore the role of Bd-x,and Myeloid cell leukaemia (Mcl)-1 for the apoptosis resistance of colorectal carcinoma (CRC) cells towards current treatment modalities.METHODS: BCl-XL and Mcl-1 mRNA and protein expression were analyzed in CRC cell lines as well as human CRC tissue by Western blot,quantitative PCR and immunohistochemistry.Bcl-x,and Mcl-1 protein expression was knocked down or increased in CRC cell lines by applying specific siRNAs or expression plasmids,respectively.After modulation of protein expression,CRC cells were treated with chemotherapeutic agents,an antagonistic epidermal growth factor receptor (EGFR1) antibody,an EGFR1 tyrosine kinase inhibitor,or with the death receptor ligand TRAIL.Apoptosis induction and cell viability were analyzed.RESULTS: Here we show that in human CRC tissue and various CRC cell lines both Bcl-x,and Mcl-1 are expressed.Bcl-x,expression was higher in CRC tissue than in surrounding non-malignant tissue,both on protein and mRNA level.Mcl-1 mRNA expression was significantly lower in malignant tissues.However,protein expression was slightly higher.Viability rates of CRC cells were significantly decreased after knock down of Bcl-XL expression,and,to a lower extent,after knock down of Mcl-1 expression.Furthermore,cells with reduced Bcl-xL or Mcl-1 expression was more sensitive towards oxaliplatin- and irinotecan-induced apoptosis,and in the case of Bcl-xL also towards 5-FU-induced apoptosis.On the other hand,upregulation of Bcl-XL by transfection of an expression plasmid decreased chemotherapeutic drug-induced apoptosis.EGF treatment clearly induced Bcl-xL and Mcl-1 expression in CRC cells.Apoptosis induction upon EGFR1 blockage by cetuximab or PD168393 was increased by inhibiting Hcl-1 and Bcl-xL expression.More strikingly,CD95- and TRAIL-induced apoptosis was increased by Bcl-xL knock down.CONCLUSION: Our data suggest that Bcl-xL and,to a lower extent,Mcl-1,are important anti-apoptotic factors in CRC

  14. Clinical activity of the mutant-selective EGFR inhibitor AZD9291 in patients with EGFR inhibitor—resistant non-small cell lung cancer

    OpenAIRE

    Tao JIANG; Caicun ZHOU

    2014-01-01

    The first generation epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are effective in advanced non-small cell lung cancer (NSCLC) with EGFR mutations. Unfortunately, disease progression generally occurs after 9 to 14 months of targeted therapy. The substitution of threonine with methionine at amino acid position 790 (T790M), as the second mutation in EGFR, is the most common resistance mechanism and is detected in tumor cells from more than 50-60% of patients after dis...

  15. PEG-PE-based micelles co-loaded with paclitaxel and cyclosporine A or loaded with paclitaxel and targeted by anticancer antibody overcome drug resistance in cancer cells.

    Science.gov (United States)

    Sarisozen, Can; Vural, Imran; Levchenko, Tatyana; Hincal, A Atilla; Torchilin, Vladimir P

    2012-05-01

    The over-expression of the P-glycoprotein (P-gp) in cancer cells is one of the main reasons of the acquired Multidrug Resistance (MDR). Combined treatment of MDR cancer cells with P-gp inhibitors and chemotherapeutic agents could result in reversal of resistance in P-gp-expressing cells. In this study, paclitaxel (PTX) was co-encapsulated in actively targeted (anticancer mAb 2C5-modified) polymeric lipid-core PEG-PE-based micelles with Cyclosporine A (CycA), which is one of the most effective first generation P-gp inhibitors. Cell culture studies performed using MDCKII (parental and MDR1) cell lines to investigate the potential MDR reversal effect of the formulations. The average size of both empty and loaded PEG₂₀₀₀-PE/Vitamin E mixed micelles was found between 10 and 25 nm. Zeta potentials of the formulations were found between -7 and -35 mV. The percentage of PTX in the micelles was found higher than 3% for both formulations and cumulative PTX release of about 70% was demonstrated. P-gp inhibition with CycA caused an increase in the cytotoxicity of PTX. Dual-loaded micelles demonstrated significantly higher cytotoxicity in the resistant MDCKII-MDR1 cells than micelles loaded with PTX alone. Micelle modification with mAb 2C5 results in the highest cytotoxicity against resistant cells, with or without P-gp modulator, probably because of better internalization bypassing the P-gp mechanism. Our results suggest that micelles delivering a combination of P-gp modulator and anticancer drug or micelles loaded with only PTX, but targeted with mAb 2C5 represent a promising approach to overcome drug resistance in cancer cells. PMID:22506922

  16. Up-regulation of ribosomal protein S13 and L23 are associated with multidrug-resistant phenotype of gastric cancer cells

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Aims:Prevous study using differential display-PCR had found up-regulation of ribosomal protein S13(RPS13) and L23(RPL23) in vincristine-resistant gastric cancer cells.The aim of this study was to explore the association of RPS13 and RPL23 with multidrug-resistant phenotype of gastric cancer cells.Methods:Northern blot analysis was used to determine the expression of RPS13 and RPL23 in vincristine-resistant gastric cancer cells SGC7901/VCR and its parental cells SGC7901.The full-length cDNAs encoding RPS13 and RPL23 were amplified from SGC7901/VCR cells using RT-PCR.Their sense and antisense expression vectors were constructed by DNA recombinant technique,and transferred into SGC7901 cells(sense vectors) or SGC7901/VCR cells(antisense vectors)by means of Lipofactamine.Drug sensitivity of gastric cancer cells was evalu-ated using MTT assay.Cell cycle analysis was performed using flow cytometry and proliferous index(PI) was calculated.Results:As Northem blot analysis indicated,RNA from SGC7902/VCR cells exhibited moderate signals of PRL23 and RPS13,while RNA from SGC7901 cells exhibited no signal of RPL23 and very weak signal of RPS13.RNA dot blot analysis indicated that RPS13 or RPL23 upregulated SGC7901 cells(SGC7901-RPS13,SGC7901-RPL23)and RPS13 or RPL23 down-regulated SGC7901/VCR cells(SGC7901/VCR-anRPS13,SGC7901/VCR-anRPL23) were successfully prepared by gene transduction.The results of MTT assay indicated that,comparing with non-transfected and empty vector transfected cells,SGC7901-RPL23 cells showed significantly increased IC50 values and resistance index(RI) of vincristine(VCR),adriamycin(ADR),5-fludrouracil(5-Fu) and mitomycin(MMC);SGC7901-RPS12 cells showed significantly increased IC50 values and RI of VCR,ADR and 5-Fu;SGC7901/VCR-anRPL23 cells showed significantly decreased IC50 values and RI of MMC and cisplatin(DDP);SGC7901/VCR-anRPS13 cells showed significantly decreased IC50 values and RI of VCR and MMC.Cell cycle analysis indicated that,comparing with

  17. The use of circulating tumor cells in guiding treatment decisions for patients with metastatic castration-resistant prostate cancer.

    Science.gov (United States)

    Onstenk, Wendy; de Klaver, Willemijn; de Wit, Ronald; Lolkema, Martijn; Foekens, John; Sleijfer, Stefan

    2016-05-01

    The therapeutic landscape of metastatic castration-resistant prostate cancer (mCRPC) has drastically changed over the past decade with the advent of several new anti-tumor agents. Oncologists increasingly face dilemmas concerning the best treatment sequence for individual patients since most of the novel compounds have been investigated and subsequently positioned either pre- or post-docetaxel. A currently unmet need exists for biomarkers able to guide treatment decisions and to capture treatment resistance at an early stage thereby allowing for an early change to an alternative strategy. Circulating tumor cells (CTCs) have in this context intensively been investigated over the last years. The CTC count, as determined by the CellSearch System (Janssen Diagnostics LLC, Raritan, NJ), is a strong, independent prognostic factor for overall survival in patients with mCRPC at various time points during treatment and, as an early response marker, outperforms traditional response evaluations using serum prostate specific antigen (PSA) levels, scintigraphy as well as radiography. The focus of research is now shifting toward the predictive value of CTCs and the use of the characterization of CTCs to guide the selection of treatments with the highest chance of success for individual patients. Recently, the presence of the androgen receptor splice variant 7 (AR-V7) has been shown to be a promising predictive factor. In this review, we have explored the clinical value of the enumeration and characterization of CTCs for the treatment of mCRPC and have put the results obtained from recent studies investigating the prognostic and predictive value of CTCs into clinical perspective. PMID:27107266

  18. Acquired EGFR C797S mediates resistance to AZD9291 in advanced non-small cell lung cancer harboring EGFR T790M

    OpenAIRE

    Thress, Kenneth S.; Paweletz, Cloud P.; Felip, Enriqueta; Cho, Byoung Chul; Stetson, Daniel; Dougherty, Brian; Lai, Zhongwu; Markovets, Aleksandra; Vivancos, Ana; Kuang, Yanan; Ercan, Dalia; Matthews, Sarah; Cantarini, Mireille; Barrett, J. Carl; Jänne, Pasi A.

    2015-01-01

    Here we studied cell-free plasma DNA (cfDNA) collected from subjects with advanced lung cancer whose tumors had developed resistance to the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) AZD9291. We first performed next-generation sequencing of cfDNA from seven subjects and detected an acquired EGFR C797S mutation in one; expression of this mutant EGFR construct in a cell line rendered it resistant to AZD9291. We then performed droplet digital PCR on serial cfDNA spec...

  19. MiR-27b is epigenetically downregulated in tamoxifen resistant breast cancer cells due to promoter methylation and regulates tamoxifen sensitivity by targeting HMGB3.

    Science.gov (United States)

    Li, Xiunan; Wu, Yumei; Liu, Aihui; Tang, Xin

    2016-09-01

    MiR-27b downregulation is significantly associated with tamoxifen resistance in breast cancer cells. However, how it is downregulated in tamoxifen resistant (TamR) breast cancer cells and its downstream regulation were not clear. By performing MSP assay and QRT-PCR analysis with the use of 5-AZA-dC, a DNA methyltransferase inhibitor, we observed that TamR MCF-7 cells had significantly higher levels of methylation in the miR-27b promoter region than tamoxifen sensitive MCF-7 (TamS) cells and demethylation restored miR-27b expression. Re-expression of miR-27b sensitized TamR MCF-7 cells to tamoxifen, inhibited invasion and reversed epithelial-mesenchymal transition (EMT)-like properties. By using bioinformatics analysis and following dual luciferase and western blot analysis, this study confirmed a direct regulation of miR-27b on HMGB3 expression by binding to the 3'UTR. In addition, this study also found that silencing of HMGB3 indeed partially phenocopied the effects of miR-27b in reducing tamoxifen resistance and cell invasion and in reversing EMT-like properties. Therefore, we infer that HMGB3 is a functional target of miR-27b in modulation of tamoxifen resistance and EMT. PMID:27363334

  20. Interference with endogenous EZH2 reverses the chemotherapy drug resistance in cervical cancer cells partly by up-regulating Dicer expression.

    Science.gov (United States)

    Cai, Liqiong; Wang, Zehua; Liu, Denghua

    2016-05-01

    Cervical cancer is one of the most common female malignancies in the world, and chemotherapeutic drug resistance is a major obstacle to cancer therapy. Enhancer of zeste homolog 2 (EZH2) is an enzymatic subunit of polycomb repressive complex 2 (PRC2) and catalyzes the repressive histone H3 lysine 27 trimethylation (H3K27me3). However, the role of EZH2 on the chemotherapy drug resistance in cervical cancers remains unclear. In the present study, the cervical carcinoma specimens and paired normal tissue specimens were obtained and the expression of EZH2 was detected by western blotting. The results showed that high levels of EZH2 were detected in cervical carcinoma tissues, compared with paired control tissues (**p experiments results demonstrated that interference with endogenous EZH2 by shRNA specific to EZH2 or inhibition EZH2 by DZNep could significantly increase antitumor effects in nude mice. Thus, inhibiting the levels of endogenous EZH2 effectively reversed the cisplatin resistance and increased the cisplatin sensitivity in cisplatin-resistant HeLa/DDP cells. EZH2 might be a potential target for treating chemotherapeutic drug-resistant cervical cancers. PMID:26631032

  1. Reversal of multidrug resistance in breast cancer MCF-7/ADR cells by h-R3-siMDR1-PAMAM complexes.

    Science.gov (United States)

    Li, Jun; Liu, Jing; Guo, Nana; Zhang, Xiaoning

    2016-09-10

    Multidrug resistance (MDR) among breast cancer cells is the paramount obstacle for the successful chemotherapy. In this study, anti-EGFR antibody h-R3 was designed to self-assembled h-R3-siRNA-PAMAM-complexes (HSPCs) via electrostatic interactions for siRNA delivery. The physicochemical characterization, cell uptake, MDR1 silencing efficiency, cell migration, cell growth and cell apoptosis were investigated. The HSPCs presented lower cytotoxicity, higher cellular uptake and enhanced endosomal escape ability. Also, HSPCs encapsulating siMDR1 knockdowned 99.4% MDR1 gene with up to ∼6 times of enhancement compared to naked siMDR1, increased the doxorubicin accumulation, down-regulated P-glycoprotein (P-gp) expression and suppressed cellular migration in breast cancer MCF-7/ADR cells. Moreover, the combination of anticancer drug paclitaxel (PTX) and siMDR1 loaded HSPCs showed synergistic effect on overcoming MDR, which inhibited cell growth and induced cell apoptosis. This h-R3-mediated siMDR1 delivery system could be a promising vector for effective siRNA therapy of drug resistant breast cancer. PMID:27444552

  2. The antipsychotic drug chlorpromazine enhances the cytotoxic effect of tamoxifen in tamoxifen-sensitive and tamoxifen-resistant human breast cancer cells

    DEFF Research Database (Denmark)

    Yde, Christina Westmose; Clausen, Mathias Porsmose; Bennetzen, Martin;

    2009-01-01

    interacts strongly with lipid bilayers of different composition leading to increased permeability. This implies that chlorpromazine can change influx properties of membranes hence suggesting that chlorpromazine may be a promising chemosensitizing compound for enhancing the cytotoxic effect of tamoxifen...... compound is now also recognized as a multitargeting drug with diverse potential applications, for example, it has antiproliferative properties and it can reverse resistance toward antibiotics in bacteria. Furthermore, chlorpromazine can reverse multidrug resistance caused by overexpression of P......-glycoprotein in cancer cells. In this study, we have investigated the effect of chlorpromazine on tamoxifen response of human breast cancer cells. We found that chlorpromazine worked synergistically together with tamoxifen with respect to reduction of cell growth and metabolic activity, both in the antiestrogen...

  3. The erbB3- and IGF-1 receptor-initiated signaling pathways exhibit distinct effects on lapatinib sensitivity against trastuzumab-resistant breast cancer cells.

    Science.gov (United States)

    Lyu, Hui; Yang, Xiao He; Edgerton, Susan M; Thor, Ann D; Wu, Xiaoying; He, Zhimin; Liu, Bolin

    2016-01-19

    Both erbB3 and IGF-1 receptor (IGF-1R) have been shown to play an important role in trastuzumab resistance. However, it remains unclear whether erbB3- and IGF-1R-initiated signaling pathways possess distinct effects on the sensitivity of lapatinib, a dual tyrosine kinase inhibitor against both EGFR and erbB2, in trastuzumab-resistant breast cancer. Here, we show that the trastuzumab-resistant SKBR3-pool2 and BT474-HR20 breast cancer sublines, as compared the parental SKBR3 and BT474 cells, respectively, exhibit refractoriness to lapatinib. Knockdown of erbB3 inhibited Akt in SKBR3-pool2 and BT474-HR20 cells, significantly increased lapatinib efficacy, and dramatically re-sensitized the cells to lapatinib-induced apoptosis. In contrast, specific knockdown of IGF-1R did not alter the cells' responsiveness to lapatinib. While the levels of phosphorylated Src (P-Src) were reduced upon IGF-1R downregulation, the P-Akt levels remained unchanged. Furthermore, a specific inhibitor of Akt, but not Src, significantly enhanced lapatinib-mediated anti-proliferative/anti-survival effects on SKBR3-pool2 and BT474-HR20 cells. These data indicate that erbB3 signaling is critical for both trastuzumab and lapatinib resistances mainly through the PI-3K/Akt pathway, whereas IGF-1R-initiated Src activation results in trastuzumab resistance without affecting lapatinib sensitivity. Our findings may facilitate the development of precision therapeutic regimens for erbB2-positive breast cancer patients who become resistant to erbB2-targeted therapy. PMID:26621843

  4. Platinum(IV) complex with adamantylamine overcomes intrinsic resistance to cisplatin in ovarian cancer cells

    Czech Academy of Sciences Publication Activity Database

    Horváth, Viktor; Blanářová, Olga; Šindlerová, Lenka; Souček, Karel; Hofmanová, Jiřina; Sova, P.; Kroutil, A.; Fedoročko, P.; Kozubík, Alois

    2006-01-01

    Roč. 102, č. 1 (2006), s. 32-40. ISSN 0090-8258 R&D Projects: GA MPO(CZ) PZ-Z2/29 Institutional research plan: CEZ:AV0Z50040507 Keywords : ovarian cancer * cisplatin * adamantylamine Subject RIV: BO - Biophysics Impact factor: 2.319, year: 2006

  5. A 3D model of ovarian cancer cell lines on peptide nanofiber scaffold to explore the cell–scaffold interaction and chemotherapeutic resistance of anticancer drugs

    Directory of Open Access Journals (Sweden)

    Zehong Yang

    2011-02-01

    Full Text Available Zehong Yang1, Xiaojun Zhao1,21Nanomedicine Laboratory, West China Hospital and Institute for Nanobiomedical Technology and Membrane Biology, Sichuan University, Chengdu, People’s Republic of China; 2Center for Biomedical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USAAbstract: RADA16-I peptide hydrogel, a type of nanofiber scaffold derived from self-assembling peptide RADA16-I, has been extensively applied to regenerative medicine and tissue repair in order to develop novel nanomedicine systems. In this study, using RADA16-I peptide hydrogel, a three-dimensional (3D cell culture model was fabricated for in vitro culture of three ovarian cancer cell lines. Firstly, the peptide nanofiber scaffold was evaluated by transmission electron microscopy and atom force microscopy. Using phase contrast microscopy, the appearance of the representative ovarian cancer cells encapsulated in RADA16-I peptide hydrogel on days 1, 3, and 7 in 24-well Petri dishes was illustrated. The cancer cell–nanofiber scaffold construct was cultured for 5 days, and the ovarian cancer cells had actively proliferative potential. The precultured ovarian cancer cells exhibited nearly similar adhesion properties and invasion potentials in vitro between RADA16-I peptide nanofiber and type I collagen, which suggested that RADA16-I peptide hydrogel had some similar characteristics to type I collagen. The precultured ovarian cancer cells had two-fold to five-fold higher anticancer drug resistance than the conventional two-dimensional Petri dish culture. So the 3D cell model on peptide nanofiber scaffold is an optimal type of cell pattern for anticancer drug screening and tumor biology.Keywords: 3D culture, anticancer drug, nanofiber scaffold, cell viability, ovarian cancer

  6. Methotrexate diethyl ester-loaded lipid-core nanocapsules in aqueous solution increased antineoplastic effects in resistant breast cancer cell line

    Directory of Open Access Journals (Sweden)

    Yurgel VC

    2014-03-01

    Full Text Available Virginia C Yurgel,1,* Catiuscia P Oliveira,2,* Karine R Begnini,1 Eduarda Schultze,1 Helena S Thurow,1 Priscila MM Leon,1 Odir A Dellagostin,1 Vinicius F Campos,1 Ruy CR Beck,2 Silvia S Guterres,2 Tiago Collares,1 Adriana R Pohlmann,2–4 Fabiana K Seixas11Programa de Pós-Graduação em Biotecnologia (PPGB, Grupo de Pesquisa em Oncologia Celular e Molecular, Laboratório de Genômica Funcional, Biotecnologia/Centro de Desenvolvimento Tecnológico, Universidade Federal de Pelotas, Pelotas, Rio Grande do Sul, Brazil; 2Programa de Pós-Graduação em Ciências Farmacêuticas, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil; 3Departamento de Química Orgânica, Instituto de Química, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil; 4Centro de Nanociência e Nanotecnologia, CNANO-UFRGS, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil*These authors contributed equally to this workAbstract: Breast cancer is the most frequent cancer affecting women. Methotrexate (MTX is an antimetabolic drug that remains important in the treatment of breast cancer. Its efficacy is compromised by resistance in cancer cells that occurs through a variety of mechanisms. This study evaluated apoptotic cell death and cell cycle arrest induced by an MTX derivative (MTX diethyl ester [MTX(OEt2] and MTX(OEt2-loaded lipid-core nanocapsules in two MTX-resistant breast adenocarcinoma cell lines, MCF-7 and MDA-MB-231. The formulations prepared presented adequate granulometric profile. The treatment responses were evaluated through flow cytometry. Relying on the mechanism of resistance, we observed different responses between cell lines. For MCF-7 cells, MTX(OEt2 solution and MTX(OEt2-loaded lipid-core nanocapsules presented significantly higher apoptotic rates than untreated cells and cells incubated with unloaded lipid-core nanocapsules. For MDA-MB-231

  7. hMENA(11a) contributes to HER3-mediated resistance to PI3K inhibitors in HER2-overexpressing breast cancer cells.

    Science.gov (United States)

    Trono, P; Di Modugno, F; Circo, R; Spada, S; Di Benedetto, A; Melchionna, R; Palermo, B; Matteoni, S; Soddu, S; Mottolese, M; De Maria, R; Nisticò, P

    2016-02-18

    Human Mena (hMENA), an actin regulatory protein of the ENA/VASP family, cooperates with ErbB receptor family signaling in breast cancer. It is overexpressed in high-risk preneoplastic lesions and in primary breast tumors where it correlates with HER2 overexpression and an activated status of AKT and MAPK. The concomitant overexpression of hMENA and HER2 in breast cancer patients is indicative of a worse prognosis. hMENA is expressed along with alternatively expressed isoforms, hMENA(11a) and hMENAΔv6 with opposite functions. A novel role for the epithelial-associated hMENA(11a) isoform in sustaining HER3 activation and pro-survival pathways in HER2-overexpressing breast cancer cells has been identified by reverse phase protein array and validated in vivo in a series of breast cancer tissues. As HER3 activation is crucial in mechanisms of cell resistance to PI3K inhibitors, we explored whether hMENA(11a) is involved in these resistance mechanisms. The specific hMENA(11a) depletion switched off the HER3-related pathway activated by PI3K inhibitors and impaired the nuclear accumulation of HER3 transcription factor FOXO3a induced by PI3K inhibitors, whereas PI3K inhibitors activated hMENA(11a) phosphorylation and affected its localization. At the functional level, we found that hMENA(11a) sustains cell proliferation and survival in response to PI3K inhibitor treatment, whereas hMENA(11a) silencing increases molecules involved in cancer cell apoptosis. As shown in three-dimensional cultures, hMENA(11a) contributes to resistance to PI3K inhibition because its depletion drastically reduced cell viability upon treatment with PI3K inhibitor BEZ235. Altogether, these results indicate that hMENA(11a) in HER2-overexpressing breast cancer cells sustains HER3/AKT axis activation and contributes to HER3-mediated resistance mechanisms to PI3K inhibitors. Thus, hMENA(11a) expression can be proposed as a marker of HER3 activation and resistance to PI3K inhibition therapies, to

  8. Chemotherapy targeting cancer stem cells

    OpenAIRE

    Liu, Haiguang; Lv, Lin; Yang, Kai

    2015-01-01

    Conventional chemotherapy is the main treatment for cancer and benefits patients in the form of decreased relapse and metastasis and longer overall survival. However, as the target therapy drugs and delivery systems are not wholly precise, it also results in quite a few side effects, and is less efficient in many cancers due to the spared cancer stem cells, which are considered the reason for chemotherapy resistance, relapse, and metastasis. Conventional chemotherapy limitations and the cance...

  9. The expression and significance of multi-drug resistance genes in breast cancer stem cells%乳腺癌干细胞多药耐药基因的表达及意义

    Institute of Scientific and Technical Information of China (English)

    Zhi Li; Chunping Liu; Yanli He; Jinghui Zhang; Tao Huang

    2008-01-01

    Objective:To approach the expressions of MDR1 and BCRP in breast cancer stem cells and differentiated cells.Methods:The breast cancer stem calls were separated from human breast cancer primary tissues and MCF-7 by flow cytometry.Then we measured the expressions of MDR1 and BCRP with different subset cells by Realtime-PCR.Results:Contrasted with breast cancer differentiated cells,the expressions of MDR1 and BCRP in breast cancer stem calls were higher (P<0.01),and the proportion of stem cells rose after chemotherapy (P<0.01).Conclusion:Contrasted with breast cancer differentiated cells,breast cancer stem cells have stronger ability of clrug-resistanca with higher level of multi-drug resistance genes,and it is one of key points for chemotherapy failure of breast cancer.

  10. Anticancer Effects of Paris Saponins by Apoptosis and PI3K/AKT Pathway in Gefitinib-Resistant Non-Small Cell Lung Cancer.

    Science.gov (United States)

    Zhu, XinHai; Jiang, Hao; Li, Jinhui; Xu, Ji; Fei, Zhenghua

    2016-01-01

    BACKGROUND Paris saponins have been studied for their anticancer effects in various cancer types, but the mechanisms underlying the cytotoxic effects, especially in EGFR-TKI-resistant cells, are still unclear. We explored the potential mechanism of the antitumor effects of PSI, II, VI, VII in EGFR-TKI-resistant cells and attempted to develop PSI, II, VI, VII as a systemic treatment strategy for EGFR-TKI-resistant lung cancer. MATERIAL AND METHODS Growth inhibition was detected by MTT assay. The apoptosis assay was detected using annexin-V/PI and Hoechst staining. The level of PI3K, pAKT, Bax, Bcl-2, caspase-3, and caspase-9 protein expression were detected using Western blot analysis. RESULTS The results revealed that PSI, II, VI, VII inhibited the proliferation of PC-9-ZD cells. Furthermore, PSI, II, VI, VII induced significant cell apoptosis. The levels of PI3K, pAKT, Bcl-2 protein decreased, while the Bax, caspase-3, and caspase-9 protein was increased by PSI, II, PSVI, PSVII treatment and resulted in increased sensitivity to gefitinib in PC-9-ZD cells. CONCLUSIONS The underlying mechanism of Paris saponins may be related to targeting the PI3K/AKT pathways to cause apoptosis. Our results suggest a therapeutic potential of Paris saponins in clinical settings for gefitinib-resistant NSCLC. PMID:27125283

  11. Collateral Chemoresistance to Anti-Microtubule Agents in a Lung Cancer Cell Line with Acquired Resistance to Erlotinib

    OpenAIRE

    Hiroshi Mizuuchi; Kenichi Suda; Katsuaki Sato; Shuta Tomida; Yoshihiko Fujita; Yoshihisa Kobayashi; Yoshihiko Maehara; Yoshitaka Sekido; Kazuto Nishio; Tetsuya Mitsudomi

    2015-01-01

    Various alterations underlying acquired resistance to epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) have been described. Although treatment strategies specific for these mechanisms are under development, cytotoxic agents are currently employed to treat many patients following failure of EGFR-TKIs. However, the effect of TKI resistance on sensitivity to these cytotoxic agents is mostly unclear. This study investigated the sensitivity of erlotinib-resistant tumor cells...

  12. Tumor Initiating Cells and FZD8 play a major role in drug resistance in Triple-Negative Breast Cancer

    OpenAIRE

    Yin, Shuping; Xu, Liping; Bonfil, R. Daniel; Banerjee, Sanjeev; Sarkar, Fazlul H; Sethi, Seema; Reddy, Kaladhar B.

    2013-01-01

    Triple-negative breast cancer (TNBC) studies have shown that neoadjuvant chemotherapy before surgery was effective in the minority of women, whereas the majority who had residual tumor had a relatively poor outcome. To identify the mechanism by which residual cancer cells survive chemotherapy, we initially performed gene expression profiling using the CRL2335 TNBC cell line derived from a squamous breast carcinoma before and after treatment with cisplatin plus TRAIL. We found a significant in...

  13. Lung cancer tumorigenicity and drug resistance are maintained through ALDHhiCD44hi tumor initiating cells

    OpenAIRE

    Liu, Jing; Xiao, Zhijie; Wong, Sunny Kit-Man; Tin, Vicky Pui-Chi; Ho, Ka-Yan; Wang, Junwen; Sham, Mai-Har; Wong, Maria Pik

    2013-01-01

    Limited improvement in long term survival of lung cancer patients has been achieved by conventional chemotherapy or targeted therapy. To explore the potentials of tumor initiating cells (TIC)-directed therapy, it is essential to identify the cell targets and understand their maintenance mechanisms. We have analyzed the performance of ALDH/CD44 co-expression as TIC markers and treatment targets of lung cancer using well-validated in vitro and in vivo analyses in multiple established and patien...

  14. Magnetic fluid hyperthermia enhances cytotoxicity of bortezomib in sensitive and resistant cancer cell lines

    OpenAIRE

    Alvarez-Berríos MP; Castillo A.; Rinaldi C; Torres-Lugo M

    2013-01-01

    Merlis P Alvarez-Berríos,1 Amalchi Castillo,1 Carlos Rinaldi,1–3 Madeline Torres-Lugo1 1Department of Chemical Engineering, University of Puerto Rico, Mayagüez, Puerto Rico; 2J Crayton Pruitt Family Department of Biomedical Engineering, 3Department of Chemical Engineering, University of Florida, Gainesville, FL, USA Abstract: The proteasome inhibitor bortezomib (BZ) has shown promising results in some types of cancer, but in others it has had minimal activity. Recent studie...

  15. Hormone resistance in two MCF-7 breast cancer cell lines is associated with reduced mTOR signaling, decreased glycolysis and increased sensitivity to cytotoxic drugs

    Directory of Open Access Journals (Sweden)

    Euphemia Yee Leung

    2014-09-01

    Full Text Available The mTOR pathway is a key regulator of multiple cellular signaling pathways and is a potential target for therapy. We have previously developed two hormone-resistant sub-lines of the MCF-7 human breast cancer line, designated TamC3 and TamR3, which were characterized by reduced mTOR signaling, reduced cell volume and resistance to mTOR inhibition. Here we show that these lines exhibit increased sensitivity to carboplatin, oxaliplatin, 5-fluorouracil, camptothecin, doxorubicin, paclitaxel, docetaxel and hydrogen peroxide. The mechanisms underlying these changes have not yet been characterized but may include a shift from glycolysis to mitochondrial respiration. If this phenotype is found in clinical hormone-resistant breast cancers, conventional cytotoxic therapy may be a preferred option for treatment.

  16. MRP1 and glucosylceramide are coordinately over expressed and enriched in rafts during multidrug resistance acquisition in colon cancer cells

    NARCIS (Netherlands)

    Klappe, K; Hinrichs, JWJ; Kroesen, BJ; Sietsma, H; Kok, JW

    2004-01-01

    Previously we have described a novel multidrug-resistant cell line, HT29(col), which displayed over expression of the multidrug-resistance protein 1 (MRP1) and an altered sphingolipid composition, including enhanced levels of glucosylceramide (GlcCer; Kok JW, Veldman RJ, Klappe K, Koning H, Filipean

  17. Activation of Multiple ERBB Family Receptors Mediates Glioblastoma Cancer Stem-like Cell Resistance to EGFR-Targeted Inhibition12

    OpenAIRE

    Clark, Paul A.; Iida, Mari; Daniel M. Treisman; Kalluri, Haviryaji; Ezhilan, Sathyapriya; Zorniak, Michael; Deric L. Wheeler; Kuo, John S.

    2012-01-01

    Epidermal growth factor receptor (EGFR) signaling is strongly implicated in glioblastoma (GBM) tumorigenesis. However, molecular agents targeting EGFR have demonstrated minimal efficacy in clinical trials, suggesting the existence of GBM resistance mechanisms. GBM cells with stem-like properties (CSCs) are highly efficient at tumor initiation and exhibit therapeutic resistance. In this study, GBMCSC lines showed sphere-forming and tumor initiation capacity after EGF withdrawal from cell cultu...

  18. Collateral chemoresistance to anti-microtubule agents in a lung cancer cell line with acquired resistance to erlotinib.

    Science.gov (United States)

    Mizuuchi, Hiroshi; Suda, Kenichi; Sato, Katsuaki; Tomida, Shuta; Fujita, Yoshihiko; Kobayashi, Yoshihisa; Maehara, Yoshihiko; Sekido, Yoshitaka; Nishio, Kazuto; Mitsudomi, Tetsuya

    2015-01-01

    Various alterations underlying acquired resistance to epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) have been described. Although treatment strategies specific for these mechanisms are under development, cytotoxic agents are currently employed to treat many patients following failure of EGFR-TKIs. However, the effect of TKI resistance on sensitivity to these cytotoxic agents is mostly unclear. This study investigated the sensitivity of erlotinib-resistant tumor cells to five cytotoxic agents using an in vitro EGFR-TKI-resistant model. Four erlotinib-sensitive lung adenocarcinoma cell lines and their resistant derivatives were tested. Of the resistant cell lines, all but one showed a similar sensitivity to the tested drugs as their parental cells. HCC4006ER cells with epithelial mesenchymal transition features acquired resistance to the three microtubule-targeting agents, docetaxel, paclitaxel and vinorelbine, but not to cisplatin and gemcitabine. Gene expression array and immunoblotting demonstrated that ATP-binding cassette subfamily B, member 1 (ABCB1) was up-regulated in HCC4006ER cells. ABCB1 knockdown by siRNA partially restored sensitivity to the anti-microtubule agents but not to erlotinib. Moreover, the histone deacetylase inhibitor entinostat sensitized HCC4006ER cells to anti-microtubule agents through ABCB1 suppression. Our study indicates that sensitivity of tumor cells to cytotoxic agents in general does not change before and after failure of EGFR-TKIs. However, we describe that two different molecular alterations confer acquired resistance to EGFR-TKIs and cytotoxic agents, respectively. This phenomenon should be kept in mind in selection of subsequent therapy after failure of EGFR-TKIs. PMID:25875914

  19. Collateral chemoresistance to anti-microtubule agents in a lung cancer cell line with acquired resistance to erlotinib.

    Directory of Open Access Journals (Sweden)

    Hiroshi Mizuuchi

    Full Text Available Various alterations underlying acquired resistance to epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs have been described. Although treatment strategies specific for these mechanisms are under development, cytotoxic agents are currently employed to treat many patients following failure of EGFR-TKIs. However, the effect of TKI resistance on sensitivity to these cytotoxic agents is mostly unclear. This study investigated the sensitivity of erlotinib-resistant tumor cells to five cytotoxic agents using an in vitro EGFR-TKI-resistant model. Four erlotinib-sensitive lung adenocarcinoma cell lines and their resistant derivatives were tested. Of the resistant cell lines, all but one showed a similar sensitivity to the tested drugs as their parental cells. HCC4006ER cells with epithelial mesenchymal transition features acquired resistance to the three microtubule-targeting agents, docetaxel, paclitaxel and vinorelbine, but not to cisplatin and gemcitabine. Gene expression array and immunoblotting demonstrated that ATP-binding cassette subfamily B, member 1 (ABCB1 was up-regulated in HCC4006ER cells. ABCB1 knockdown by siRNA partially restored sensitivity to the anti-microtubule agents but not to erlotinib. Moreover, the histone deacetylase inhibitor entinostat sensitized HCC4006ER cells to anti-microtubule agents through ABCB1 suppression. Our study indicates that sensitivity of tumor cells to cytotoxic agents in general does not change before and after failure of EGFR-TKIs. However, we describe that two different molecular alterations confer acquired resistance to EGFR-TKIs and cytotoxic agents, respectively. This phenomenon should be kept in mind in selection of subsequent therapy after failure of EGFR-TKIs.

  20. Resistance of Lung Cancer Cells Grown as Multicellular Tumour Spheroids to Zinc Sulfophthalocyanine Photosensitization

    Directory of Open Access Journals (Sweden)

    Sello Lebohang Manoto

    2015-05-01

    Full Text Available Photodynamic therapy (PDT is phototherapeutic modality used in the treatment of neoplastic and non-neoplastic diseases. The photochemical interaction of light, photosensitizer (PS and molecular oxygen produces singlet oxygen which induces cell death. Zinc sulfophthalocyanine (ZnPcSmix has been shown to be effective in A549 monolayers, multicellular tumor spheroids (MCTSs (250 µm and not on MCTSs with a size of 500 µm. A549 cells used in this study were grown as MCTSs to a size of 500 µm in order to determine their susceptibility to PDT. ZnPcSmix distribution in MCTSs and nuclear morphology was determined using a fluorescent microscope. Changes in cellular responses were evaluated using cell morphology, viability, proliferation, cytotoxicity, cell death analysis and mitochondrial membrane potential. Untreated MCTSs, showed no changes in cellular morphology, proliferation, cytotoxicity and nuclear morphology. Photoactivated ZnPcSmix also showed no changes in cellular morphology and nuclear morphology. However, photoactivated ZnPcSmix resulted in a significant dose dependant decrease in viability and proliferation as well as an increase in cell membrane damage in MCTSs over time. ZnPcSmix photosensitization induces apoptotic cell death in MCTSs with a size of 500 µm and more resistantance when compared to monolayer cells and MCTSs with a size of 250 µm.

  1. Cordycepin Down-Regulates Multiple Drug Resistant (MDR/HIF-1α through Regulating AMPK/mTORC1 Signaling in GBC-SD Gallbladder Cancer Cells

    Directory of Open Access Journals (Sweden)

    Wei-Ding Wu

    2014-07-01

    Full Text Available Gallbladder cancer is the most common malignancy of the bile duct, with low 5-year survival rate and poor prognosis. Novel effective treatments are urgently needed for the therapy of this disease. Here, we showed that cordycepin, the bioactive compound in genus Cordyceps, induced growth inhibition and apoptosis in cultured gallbladder cancer cells (Mz-ChA-1, QBC939 and GBC-SD lines. We found that cordycepin inhibited mTOR complex 1 (mTORC1 activation and down-regulated multiple drug resistant (MDR/hypoxia-inducible factor 1α (HIF-1α expression through activating of AMP-activated protein kinase (AMPK signaling in gallbladder cancer GBC-SD cells. Contrarily, AMPKα1-shRNA depletion dramatically inhibited cordycepin-induced molecular changes as well as GBC-SD cell apoptosis. Further, our results showed that co-treatment with a low concentration cordycepin could remarkably enhance the chemosensitivity of GBC-SD cells to gemcitabine and 5-fluorouracil (5-FU, and the mechanism may be attributed to AMPK activation and MDR degradation. In summary, cordycepin induces growth inhibition and apoptosis in gallbladder cancer cells via activating AMPK signaling. Cordycepin could be a promising new drug or chemo-adjuvant for gallbladder cancer.

  2. Radiation resistance due to high expression of miR-21 and G2/M checkpoint arrest in breast cancer cells

    International Nuclear Information System (INIS)

    There is evidence that the extent of the G2/M arrest following irradiation is correlated with tumour cell survival and hence therapeutic success. We studied the regulation of cellular response to radiation treatment by miR-21-mediated modulation of cell cycle progression in breast cancer cells and analysed miR-21 expression in breast cancer tissue samples with long-term follow up. The miR-21 expression levels were quantified (qRT-PCR) in a panel of 86 cases of invasive breast carcinomas in relation to metastasis free survival. The cellular radiosensitivity of human breast cancer cells after irradiation was determined comparing two cell lines (T47D and MDA-MB-361) by cell proliferation and colony forming assays. The influence of miR-21 overexpression or downregulation on cell cycle progression and G2/M checkpoint arrest after irradiation was assessed by flow cytometric analysis. The expression of miR-21 was transiently increased 8 hours after irradiation in the radioresistant T47D cells and significantly changed with lower extent in radiosensitive MDA-MB-361 cells. Anti-miR-21 treated breast cancer cells failed to exhibit the DNA damage-G2 checkpoint increase after irradiation. Apoptotic activity was significantly enhanced from 7% to 27% in T47D cel