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Sample records for p15ink4b p16ink4a p21cip1

  1. Inactivation of p16INK4a, with retention of pRB and p53/p21cip1 function, in human MRC5 fibroblasts that overcome a telomere-independent crisis during immortalization.

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    Taylor, Lisa M; James, Alexander; Schuller, Christine E; Brce, Jesena; Lock, Richard B; Mackenzie, Karen L

    2004-10-15

    Recent investigations, including our own, have shown that specific strains of fibroblasts expressing telomerase reverse transcriptase (hTERT) have an extended lifespan, but are not immortal. We previously demonstrated that hTERT-transduced MRC5 fetal lung fibroblasts (MRC5hTERTs) bypassed senescence but eventually succumbed to a second mortality barrier (crisis). In the present study, 67 MRC5hTERT clones were established by limiting dilution of a mass culture. Whereas 39/67 clones had an extended lifespan, all 39 extended lifespan clones underwent crisis. 11 of 39 clones escaped crisis and were immortalized. There was no apparent relationship between the fate of clones at crisis and the level of telomerase activity. Telomeres were hyperextended in the majority of the clones analyzed. There was no difference in telomere length of pre-crisis compared with post-crisis and immortal clones, indicating that hyperextended telomeres were conducive for immortalization and confirming that crisis was independent of telomere length. Immortalization of MRC5hTERT cells was associated with repression of the cyclin-dependent kinase inhibitor p16INK4a and up-regulation of pRB. However, the regulation of pRB phosphorylation and the response of the p53/p21cip1/waf1 pathway were normal in immortal cells subject to genotoxic stress. Overexpression of oncogenic ras failed to de-repress p16INK4a in immortal cells. Furthermore, expression of ras enforced senescent-like growth arrest in p16INK4a-positive, but not p16INK4a-negative MRC5hTERT cells. Immortal cells expressing ras formed small, infrequent colonies in soft agarose, but were non-tumorigenic. Overall, these results implicate the inactivation of p16INK4a as a critical event for overcoming telomere-independent crisis, immortalizing MRC5 fibroblasts and overcoming ras-induced premature senescence.

  2. Insertional mutagenesis in mice deficient for p15Ink4b, p16Ink4a, p21Cip1, and p27Kip1 reveals cancer gene interactions and correlations with tumor phenotypes

    DEFF Research Database (Denmark)

    Kool, Jaap; Uren, Anthony G; Martins, Carla P

    2010-01-01

    -throughput murine leukemia virus insertional mutagenesis screens in mice that are deficient for one or two CDK inhibitors. We retrieved 9,117 retroviral insertions from 476 lymphomas to define hundreds of loci that are mutated more frequently than expected by chance. Many of these loci are skewed toward a specific...... revealed a significant overlap between the datasets. Together, our findings highlight the importance of genetic context within large-scale mutation detection studies, and they show a novel use for insertional mutagenesis data in prioritizing disease-associated genes that emerge from genome-wide association...

  3. Inactivation of p15INK4b in chronic arsenic poisoning cases

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    Aihua Zhang

    2014-01-01

    Full Text Available Arsenic exposure from burning high arsenic-containing coal has been associated with human skin lesion and cancer. However, the mechanisms of arsenic-related carcinogenesis are not fully understood. Inactivation of critical tumor suppression genes by epigenetic regulation or genetic modification might contribute to arsenic-induced carcinogenicity. This study aims to clarify the correlation between arsenic pollution and functional defect of p15INK4b gene in arsenic exposure residents from a region of Guizhou Province, China. To this end, 103 arsenic exposure residents and 105 control subjects were recruited in this study. The results showed that the exposure group exhibited higher levels of urinary and hair arsenic compared with the control group (55.28 vs 28.87 μg/L, 5.16 vs 1.36 μg/g. Subjects with higher arsenic concentrations are more likely to have p15INK4b methylation and gene deletion (χ2 = 4.28, P = 0.04 and χ2 = 4.31, P = 0.04. We also found that the degree of p15INK4b hypermethylation and gene deletion occurred at higher incidence in the poisoning cases with skin cancer (3.7% and 14.81% in non-skin cancer group, 41.18% and 47.06 in skin cancer group, and were significantly associated with the stage of skin lesions (χ2 = 12.82, P < 0.01 and χ2 = 7.835, P = 0.005. These observations indicate that inactivation of p15INK4b through genetic alteration or epigenetic modification is a common event that is associated with arsenic exposure and the development of arsenicosis.

  4. The role of tumor suppressor p15Ink4b in the regulation of hematopoietic progenitor cell fate

    International Nuclear Information System (INIS)

    Humeniuk, R; Rosu-Myles, M; Fares, J; Koller, R; Bies, J; Wolff, L

    2013-01-01

    Epigenetic silencing of the tumor suppressor gene p15Ink4b (CDKN2B) is a frequent event in blood disorders like acute myeloid leukemia and myelodysplastic syndromes. The molecular function of p15Ink4b in hematopoietic differentiation still remains to be elucidated. Our previous study demonstrated that loss of p15Ink4b in mice results in skewing of the differentiation pattern of the common myeloid progenitor towards the myeloid lineage. Here, we investigated a function of p15Ink4b tumor suppressor gene in driving erythroid lineage commitment in hematopoietic progenitors. It was found that p15Ink4b is expressed more highly in committed megakaryocyte–erythroid progenitors than granulocyte–macrophage progenitors. More importantly, mice lacking p15Ink4b have lower numbers of primitive red cell progenitors and a severely impaired response to 5-fluorouracil- and phenylhydrazine-induced hematopoietic stress. Introduction of p15Ink4b into multipotential progenitors produced changes at the molecular level, including activation of mitogen-activated protein kinase/extracellular signal-regulated kinase (MEK/ERK) signaling, increase GATA-1, erythropoietin receptor (EpoR) and decrease Pu1, GATA-2 expression. These changes rendered cells more permissive to erythroid commitment and less permissive to myeloid commitment, as demonstrated by an increase in early burst-forming unit-erythroid formation with concomitant decrease in myeloid colonies. Our results indicate that p15Ink4b functions in hematopoiesis, by maintaining proper lineage commitment of progenitors and assisting in rapid red blood cells replenishment following stress

  5. Immunohistochemical study of p16 INK4A and survivin expressions in cervical squamous neoplasm

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    Tan Geok

    2010-01-01

    Full Text Available Introduction:Cervical cancer is the second most common cancer affecting Malaysian women. Despite the implementation of pap smear screening, many women are still diagnosed only in the advanced stage of cervical cancer. This could partly be due to failure of detection of its precursor lesions; hence the need to search for novel biomarkers to assist in the screening and diagnosis of cervical neoplasia. This study aims to determine the expression of p16INK4A and survivin as possible predictive biomarkers in cervical squamous neoplasm. Material and Methods: This is a retrospective study on 201 cases of cervical neoplasm comprising of 129 cervical intraepithelial neoplasia (CIN and 72 squamous cell carcinoma (SCC. All samples were evaluated by two independent observers using p16INK4A and survivin monoclonal antibodies. The p16 INK4A expression was graded as negative, focal and diffuse positivity. The intensity for survivin expression was graded as weak, moderate and intense. Results: It is seen that p16 INK4A expression in CIN 1, CIN 2 and CIN 3 were 25.4%, 42.9% and 95.9% respectively. Majority of SCC (98.6% showed p16 INK4A expression. Survivin expressions in CIN 1, CIN 2, CIN 3 and SCC were 56.7%, 33.4%, 87.5% and 98.6%. There was a linear relationship between increasing grade of CIN and p16 INK4A expressions. Conclusion: Our study showed that p16 INK4A expressions correlate well with the increasing grade of CIN. Although survivin does not correlate well to the increasing grade of CIN, it could be useful in differentiating CIN 3 from SCC.

  6. Expression of p16(INK4A) gene in human pituitary tumours.

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    Machiavelli, Gloria; Cotignola, Javier; Danilowicz, Karina; Carbonara, Carolina; Paes de Lima, Andrea; Basso, Armando; Bruno, Oscar Domingo; Szijan, Irene

    2008-01-01

    Pituitary adenomas comprise 10-15% of primary intracranial tumours but the mechanisms leading to tumour development are yet to be clearly established. The retinoblastoma pathway, which regulates the progression through the cell cycle, is often deregulated in different types of tumours. We studied the cyclin-dependent kinase inhibitor p16(INK4A) gene expression at mRNA level in human pituitary adenomas. Forty-six tumour specimens of different subtypes, 21 clinically non-functioning, 12 growth hormone-secreting, 6 prolactin-secreting, 6 adrenocorticotropin-secreting, and 1 thyrotropin-secreting tumours were studied. All clinically non-functioning and most of the hormone-secreting tumours were macroadenomas (38/46). The RT-PCR assay and electrophoresis of the PCR-products showed that p16(INK4A) mRNA was undetectable in: 62% of non-functioning, 8% of growth hormone-secreting, 17% of prolactin-secreting and 17% of adrenocorticotropin-secreting adenomas. Forty percent of all macroadenomas and 25% of microadenomas had negative p16(INK4A) mRNA, the latter results suggest that the absence of p16(INK4A) product might be an early event in tumours with no expression of this suppressor gene. Within the non-functioning adenomas 63% were "null cell" and 37% were positive for some hormone, both subgroups showed similar percentage of cases with absence of p16(INK4A) mRNA. Our results show that clinically non-functioning macroadenomas have impaired p16(INK4A) expression in a clearly higher proportion than any other pituitary tumour subtype investigated. Other regulatory pathways may be implicated in the development of tumours with positive p16(INK4A) expression.

  7. Investigation of p16(INK4a) as a prognostic biomarker in oral epithelial dysplasia.

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    Nankivell, Paul; Williams, Hazel; Webster, Keith; Pearson, David; High, Alec; MacLennan, Kenneth; Senguven, Burcu; McConkey, Christopher; Rabbitts, Pamela; Mehanna, Hisham

    2014-04-01

    Human papilloma virus is a risk factor for oropharyngeal cancer. Evidence for a similar aetiological role in the development of oral dysplasia or its transformation to oral cancer is not as clear. Meta-analyses estimate the prevalence of high-risk human papilloma virus (HPV) serotypes to be three times higher in pre-malignant lesions and cancer than in normal oral mucosa. However, this does not imply a causal relationship. Conflicting results are reported from the few studies examining the prognostic significance of HPV positivity in the development of oral cancer. We aimed to examine the ability of p16(INK4a) protein expression, a surrogate marker of HPV infection, to predict malignant progression in a large cohort of oral dysplasia patients. One hundred forty eight oral dysplasia cases underwent immunohistochemical analysis using a monoclonal antibody against p16(INK4a) . Clinical factors were also collated on each case. Slides were double scored independently by two trained observers. Univariate analyses using both logistic and Cox regression models were performed. Thirty nine of 148 cases progressed to cancer. Ten of 148 cases (7%) were p16(INK4a) positive. High grade of dysplasia (P = 0.0002) and lesion morphology (P = 0.03) were found to be prognostic of malignant progression. p16(INK4a) score was not prognostic in this cohort (P = 0.29). This did not change with a time to event analysis (P = 0.24). Few studies have assessed the aetiological role of HPV in cancer development from dysplastic lesions. Our study, using one of the largest cohorts of oral dysplasia, demonstrated a low rate of p16(INK4a) positivity and was unable to confirm a prognostic ability for this biomarker. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. Histone deacetylase 3 represses p15INK4b and p21WAF1/cip1 transcription by interacting with Sp1

    International Nuclear Information System (INIS)

    Huang Weifeng; Tan Dapeng; Wang Xiuli; Han Songyan; Tan Jiang; Zhao Yanmei; Lu Jun; Huang Baiqu

    2006-01-01

    Histone deacetylase 3 (HDAC3) has been implicated to play roles in governing cell proliferation. Here we demonstrated that the overexpression of HDAC3 repressed transcription of p15 INK4b and p21 WAF1/cip1 genes in 293T cells, and that the recruitment of HDAC3 to the promoter regions of these genes was critical to this repression. We also showed that HDAC3 repressed GAL4-Sp1 transcriptional activity, and that Sp1 was co-immunoprecipitated with FLAG-tagged HDAC3. We conclude that HDAC3 can repress p15 INK4b and p21 WAF1/cip1 transcription by interacting with Sp1. Furthermore, knockdown of HDAC3 by RNAi up-regulated the transcriptional expression of p15 INK4b , but not that of p21 WAF1/cip1 , implicating the different roles of HDAC3 in repression of p15 INK4b and p21 WAF1/cip1 transcription. Data from this study indicate that the inhibition of p15 INK4b and p21 WAF1/cip1 may be one of the mechanisms by which HDAC3 participates in cell cycle regulation and oncogenesis

  9. p16(INK4a) promoter methylation and protein expression in breast fibroadenoma and carcinoma.

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    Di Vinci, Angela; Perdelli, Luisa; Banelli, Barbara; Salvi, Sandra; Casciano, Ida; Gelvi, Ilaria; Allemanni, Giorgio; Margallo, Edoardo; Gatteschi, Beatrice; Romani, Massimo

    2005-04-10

    The potential role of p16(INK4a) methylation in breast cancer is controversial whereas there are no data on fibroadenoma. To assess if inactivation of p16(INK4a) by promoter hypermethylation occurs in this hyperproliferative benign breast lesion or, on the contrary, it is strictly related to the carcinogenic process, we have tested the different histological components of 15 cases of fibroadenoma and the intraductal and infiltrating components of 15 cases of carcinoma and their adjacent non-tumoral epithelium. All samples were obtained by laser-assisted microdissection. The relationship between promoter methylation status, immunohistochemical protein expression and ki67 proliferative activity was evaluated for each lesion. Our data demonstrate that hypermethylation of p16(INK4a) promoter is a common event occurring at similar frequency in all the different histological areas of the benign and malignant breast lesions taken into exam. Conversely, protein p16 expression, although heterogeneously distributed within the section, is considerably higher in breast carcinoma as compared to fibroadenoma in both tumoral and non-tumoral epithelia and stroma. The protein localization was almost exclusively nuclear in fibroadenoma and non-tumoral epithelia whereas, in carcinoma, the staining was both nuclear and cytoplasmic or cytoplasmic alone. Furthermore, in a subset of fibroadenoma with higher proliferative activity, p16 protein expression was substantially decreased as compared to those showing lower proliferation. We did not observe this association in carcinomas. Our data demonstrate that the hypermethylation of the p16(INK4a) promoter is not specifically associated with malignancy and that, on the contrary, the overexpression of p16 and its cytoplasmic sequestration is a feature of breast carcinoma. (c) 2004 Wiley-Liss, Inc.

  10. The chromatin remodelling factor BRG1 is a novel binding partner of the tumor suppressor p16INK4a

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    Mann Graham J

    2009-01-01

    Full Text Available Abstract Background CDKN2A/p16INK4a is frequently altered in human cancers and it is the most important melanoma susceptibility gene identified to date. p16INK4a inhibits pRb phosphorylation and induces cell cycle arrest, which is considered its main tumour suppressor function. Nevertheless, additional activities may contribute to the tumour suppressor role of p16INK4a and could help explain its specific association with melanoma predisposition. To identify such functions we conducted a yeast-two-hybrid screen for novel p16INK4a binding partners. Results We now report that p16INK4a interacts with the chromatin remodelling factor BRG1. We investigated the cooperative roles of p16INK4a and BRG1 using a panel of cell lines and a melanoma cell model with inducible p16INK4a expression and BRG1 silencing. We found evidence that BRG1 is not required for p16INK4a-induced cell cycle inhibition and propose that the p16INK4a-BRG1 complex regulates BRG1 chromatin remodelling activity. Importantly, we found frequent loss of BRG1 expression in primary and metastatic melanomas, implicating this novel p16INK4a binding partner as an important tumour suppressor in melanoma. Conclusion This data adds to the increasing evidence implicating the SWI/SNF chromatin remodelling complex in tumour development and the association of p16INK4a with chromatin remodelling highlights potentially new functions that may be important in melanoma predisposition and chemoresistance.

  11. Disruptive cell cycle regulation involving epigenetic downregulation of Cdkn2a (p16Ink4a) in early-stage liver tumor-promotion facilitating liver cell regeneration in rats

    International Nuclear Information System (INIS)

    Tsuchiya, Takuma; Wang, Liyun; Yafune, Atsunori; Kimura, Masayuki; Ohishi, Takumi; Suzuki, Kazuhiko; Mitsumori, Kunitoshi; Shibutani, Makoto

    2012-01-01

    Cell cycle aberration was immunohistochemically examined in relation to preneoplastic liver cell foci expressing glutathione S-transferase placental form (GST-P) at early stages of tumor-promotion in rats with thioacetamide (TAA), a hepatocarcinogen facilitating liver cell regeneration. Immunoexpression of p16 Ink4a following exposure to other hepatocarcinogens/promoters and its DNA methylation status were also analyzed during early and late tumor-promotion stages. GST-P + liver cell foci increased cell proliferation and decreased apoptosis when compared with surrounding liver cells. In concordance with GST-P + foci, checkpoint proteins at G 1 /S (p21 Cip1 , p27 Kip1 and p16 Ink4a ) and G 2 /M (phospho-checkpoint kinase 1, Cdc25c and phospho-Wee1) were either up- or downregulated. Cellular distribution within GST-P + foci was either increased or decreased with proteins related to G 2 -M phase or DNA damage (topoisomerase IIα, phospho-histone H2AX, phospho-histone H3 and Cdc2). In particular, p16 Ink4a typically downregulated in GST-P + foci and regenerative nodules at early tumor-promotion stage with hepatocarcinogens facilitating liver cell regeneration and in neoplastic lesions at late tumor-promotion stage with hepatocarcinogens/promoters irrespective of regenerating potential. Hypermethylation at exon 2 of Cdkn2a was detected at both early- and late-stages. Thus, diverse disruptive expression of G 1 /S and G 2 /M proteins, which allows for clonal selection of GST-P + foci, results in the acquisition of multiple aberrant phenotypes to disrupt checkpoint function. Moreover, increased DNA-damage responses within GST-P + foci may be the signature of genetic alterations. Intraexonic hypermethylation may be responsible for p16 Ink4a -downregulation, which facilitates cell cycle progression in early preneoplastic lesions produced by repeated cell regeneration and late-stage neoplastic lesions irrespective of the carcinogenic mechanism.

  12. Deficiency of G1 regulators P53, P21Cip1 and/or pRb decreases hepatocyte sensitivity to TGFβ cell cycle arrest

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    Harrison David J

    2007-11-01

    Full Text Available Abstract Background TGFβ is critical to control hepatocyte proliferation by inducing G1-growth arrest through multiple pathways leading to inhibition of E2F transcription activity. The retinoblastoma protein pRb is a key controller of E2F activity and G1/S transition which can be inhibited in viral hepatitis. It is not known whether the impairment of pRb would alter the growth inhibitory potential of TGFβ in disease. We asked how Rb-deficiency would affect responses to TGFβ-induced cell cycle arrest. Results Primary hepatocytes isolated from Rb-floxed mice were infected with an adenovirus expressing CRE-recombinase to delete the Rb gene. In control cells treatment with TGFβ prevented cells to enter S phase via decreased cMYC activity, activation of P16INK4A and P21Cip and reduction of E2F activity. In Rb-null hepatocytes, cMYC activity decreased slightly but P16INK4A was not activated and the great majority of cells continued cycling. Rb is therefore central to TGFβ-induced cell cycle arrest in hepatocytes. However some Rb-null hepatocytes remained sensitive to TGFβ-induced cell cycle arrest. As these hepatocytes expressed very high levels of P21Cip1 and P53 we investigated whether these proteins regulate pRb-independent signaling to cell cycle arrest by evaluating the consequences of disruption of p53 and p21Cip1. Hepatocytes deficient in p53 or p21Cip1 showed diminished growth inhibition by TGFβ. Double deficiency had a similar impact showing that in cells containing functional pRb; P21Cip and P53 work through the same pathway to regulate G1/S in response to TGFβ. In Rb-deficient cells however, p53 but not p21Cip deficiency had an additive effect highlighting a pRb-independent-P53-dependent effector pathway of inhibition of E2F activity. Conclusion The present results show that otherwise genetically normal hepatocytes with disabled p53, p21Cip1 or Rb genes respond less well to the antiproliferative effects of TGFβ. As the function of

  13. Case report of a p16INK4A-positive branchial cleft cyst.

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    McLean, T; Iseli, C; Amott, D; Taylor, M

    2015-06-01

    To report the occurrence of a concurrent oropharyngeal papilloma and branchial cleft cyst linked by p16(INK4A) and human papillomavirus immunohistochemistry. A 42-year-old woman presented with a 1-month history of a left lateral neck mass. Contrast enhanced computed tomography showed a hypodense lesion 20 mm in diameter anteromedial to the left sternocleidomastoid muscle. Ultrasound-guided fine needle aspiration suggested a branchial cleft cyst. Panendoscopy was performed at the time of neck mass removal, and a papillomatous lesion was removed from the left hypopharynx. Histopathological analysis showed the neck lesion to be a branchial cyst containing lymphoid tissue, and the oral lesion to be a squamous papilloma. Immunohistochemical analysis showed both the branchial cleft cyst and papilloma to be positive for p16(INK4A) expression and human papillomavirus DNA. Histological and immunohistochemical analyses support the cystic transformation of lymph nodes, or the 'Inclusion Theory', as the aetiology of branchial apparatus anomalies, and raise the possibility that human papillomavirus infection may play a much larger role in disease of the head and neck than previously supposed.

  14. p16(INK4a translation suppressed by miR-24.

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    Ashish Lal

    2008-03-01

    Full Text Available Expression of the tumor suppressor p16(INK4a increases during aging and replicative senescence.Here, we report that the microRNA miR-24 suppresses p16 expression in human diploid fibroblasts and cervical carcinoma cells. Increased p16 expression with replicative senescence was associated with decreased levels of miR-24, a microRNA that was predicted to associate with the p16 mRNA coding and 3'-untranslated regions. Ectopic miR-24 overexpression reduced p16 protein but not p16 mRNA levels. Conversely, introduction of antisense (AS-miR-24 blocked miR-24 expression and markedly enhanced p16 protein levels, p16 translation, and the production of EGFP-p16 reporter bearing the miR-24 target recognition sites.Together, our results suggest that miR-24 represses the initiation and elongation phases of p16 translation.

  15. Radionuclides in cigarettes may lead to carcinogenesis via p16INK4a inactivation

    International Nuclear Information System (INIS)

    Prueitt, Robyn L.; Goodman, Julie E.; Valberg, Peter A.

    2009-01-01

    It is widely accepted that tobacco smoke is responsible for the vast majority of lung cancers worldwide. There are many known and suspected carcinogens present in cigarette smoke, including α-emitting radioisotopes. Epidemiologic studies have shown that increased lung cancer risk is associated with exposure to ionizing radiation, and it is estimated that the majority of smoking-induced lung cancers may be at least partly attributable to the inhaled and deposited radiation dose from radioisotopes in the cigarette smoke itself. Recent research shows that silencing of the tumor suppressor gene p16 INK4a (p16) by promoter methylation plays a role in smoking-related lung cancer. Inactivation of p16 has also been associated with lung cancer incidence in radiation-exposed workers, suggesting that radionuclides in cigarette smoke may be acting with other compounds to cause smoking-induced lung cancer. We evaluated the mechanism of ionizing radiation as an accepted cause of lung cancer in terms of its dose from tobacco smoke and silencing of p16. Because both radiation and cigarette smoking are associated with inactivation of p16, and p16 inactivation has been shown to play a major role in carcinogenesis, ionizing radiation from cigarette smoke likely plays a role in lung cancer risk. How large a role it plays, relative to chemical carcinogens and other modes of action, remains to be elucidated

  16. SUMO regulates p21Cip1 intracellular distribution and with p21Cip1 facilitates multiprotein complex formation in the nucleolus upon DNA damage.

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    Brun, Sonia; Abella, Neus; Berciano, Maria T; Tapia, Olga; Jaumot, Montserrat; Freire, Raimundo; Lafarga, Miguel; Agell, Neus

    2017-01-01

    We previously showed that p21Cip1 transits through the nucleolus on its way from the nucleus to the cytoplasm and that DNA damage inhibits this transit and induces the formation of p21Cip1-containing intranucleolar bodies (INoBs). Here, we demonstrate that these INoBs also contain SUMO-1 and UBC9, the E2 SUMO-conjugating enzyme. Furthermore, whereas wild type SUMO-1 localized in INoBs, a SUMO-1 mutant, which is unable to conjugate with proteins, does not, suggesting the presence of SUMOylated proteins at INoBs. Moreover, depletion of the SUMO-conjugating enzyme UBC9 or the sumo hydrolase SENP2 changed p21Cip1 intracellular distribution. In addition to SUMO-1 and p21Cip1, cell cycle regulators and DNA damage checkpoint proteins, including Cdk2, Cyclin E, PCNA, p53 and Mdm2, and PML were also detected in INoBs. Importantly, depletion of UBC9 or p21Cip1 impacted INoB biogenesis and the nucleolar accumulation of the cell cycle regulators and DNA damage checkpoint proteins following DNA damage. The impact of p21Cip1 and SUMO-1 on the accumulation of proteins in INoBs extends also to CRM1, a nuclear exportin that is also important for protein translocation from the cytoplasm to the nucleolus. Thus, SUMO and p21Cip1 regulate the transit of proteins through the nucleolus, and that disruption of nucleolar export by DNA damage induces SUMO and p21Cip1 to act as hub proteins to form a multiprotein complex in the nucleolus.

  17. p16 (INK4a) has clinicopathological and prognostic impact on oropharynx and larynx squamous cell carcinoma

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    Silva, S.D. [Departamento de Cirurgia de Cabeça e Pescoço e Otorrinolaringologia, Hospital A.C. Camargo, São Paulo, SP (Brazil); Department of Oncology, Lady Davis Institute for Medical Research and Segal Cancer Centre, Sir Mortimer B. Davis-Jewish General Hospital, McGill University, Montreal, Quebec (Canada); Department of Otolaryngology-Head and Neck Surgery, Jewish General Hospital, McGill University, Montreal, Quebec (Canada); Nonogaki, S. [Departamento de Anatomia Patológica, Hospital A.C. Camargo, São Paulo, SP (Brazil); Soares, F.A. [Departamento de Anatomia Patológica, Hospital A.C. Camargo, São Paulo, SP (Brazil); Departamento de Estomatologia, Faculdade de Odontologia, Universidade de São Paulo, São Paulo, SP (Brazil); Kowalski, L.P. [Departamento de Cirurgia de Cabeça e Pescoço e Otorrinolaringologia, Hospital A.C. Camargo, São Paulo, SP (Brazil)

    2012-09-07

    CDKN2A encodes proteins such as p16 (INK4a), which negatively regulate the cell-cycle. Molecular genetic studies have revealed that deletions in CDKN2A occur frequently in cancer. Although p16 (INK4a) may be involved in tumor progression, the clinical impact and prognostic implications in head and neck squamous cell carcinoma (HNSCC) are controversial. The objective of this study was to evaluate the frequency of the immunohistochemical expression of p16 (INK4a) in 40 oropharynx and 35 larynx from HNSCC patients treated in a single institution and followed-up at least for 10 years in order to explore potential associations with clinicopathological outcomes and prognostic implications. Forty cases (53.3%) were positive for p16 (INK4a) and this expression was more intense in non-smoking patients (P = 0.050), whose tumors showed negative vascular embolization (P = 0.018), negative lymphatic permeation (P = 0.002), and clear surgical margins (P = 0.050). Importantly, on the basis of negative p16 (INK4a) expression, it was possible to predict a probability of lower survival (P = 0.055) as well as tumors presenting lymph node metastasis (P = 0.050) and capsular rupture (P = 0.0010). Furthermore, increased risk of recurrence was observed in tumors presenting capsular rupture (P = 0.0083). Taken together, the alteration in p16 (INK4a) appears to be a common event in patients with oropharynx and larynx squamous cell carcinoma and the negative expression of this protein correlated with poor prognosis.

  18. p16 (INK4a) has clinicopathological and prognostic impact on oropharynx and larynx squamous cell carcinoma

    International Nuclear Information System (INIS)

    Silva, S.D.; Nonogaki, S.; Soares, F.A.; Kowalski, L.P.

    2012-01-01

    CDKN2A encodes proteins such as p16 (INK4a), which negatively regulate the cell-cycle. Molecular genetic studies have revealed that deletions in CDKN2A occur frequently in cancer. Although p16 (INK4a) may be involved in tumor progression, the clinical impact and prognostic implications in head and neck squamous cell carcinoma (HNSCC) are controversial. The objective of this study was to evaluate the frequency of the immunohistochemical expression of p16 (INK4a) in 40 oropharynx and 35 larynx from HNSCC patients treated in a single institution and followed-up at least for 10 years in order to explore potential associations with clinicopathological outcomes and prognostic implications. Forty cases (53.3%) were positive for p16 (INK4a) and this expression was more intense in non-smoking patients (P = 0.050), whose tumors showed negative vascular embolization (P = 0.018), negative lymphatic permeation (P = 0.002), and clear surgical margins (P = 0.050). Importantly, on the basis of negative p16 (INK4a) expression, it was possible to predict a probability of lower survival (P = 0.055) as well as tumors presenting lymph node metastasis (P = 0.050) and capsular rupture (P = 0.0010). Furthermore, increased risk of recurrence was observed in tumors presenting capsular rupture (P = 0.0083). Taken together, the alteration in p16 (INK4a) appears to be a common event in patients with oropharynx and larynx squamous cell carcinoma and the negative expression of this protein correlated with poor prognosis

  19. HFE polymorphisms influence the response to chemotherapeutic agents via induction of p16INK4A.

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    Lee, Sang Y; Liu, Siying; Mitchell, Ryan M; Slagle-Webb, Becky; Hong, Young-Soo; Sheehan, Jonas M; Connor, James R

    2011-11-01

    HFE is a protein that impacts cellular iron uptake. HFE gene variants are identified as risk factors or modifiers for multiple diseases. Using HFE stably transfected human neuroblastoma cells, we found that cells carrying the C282Y HFE variant do not differentiate when exposed to retinoic acid. Therefore, we hypothesized HFE variants would impact response to therapeutic agents. Both the human neuroblastoma and glioma cells that express the C282Y HFE variant are resistant to Temodar, geldanamycin and γ-radiation. A gene array analysis revealed that p16INK4A (p16) expression was increased in association with C282Y expression. Decreasing p16 protein by siRNA resulted in increased vulnerability to all of the therapeutic agents suggesting that p16 is responsible for the resistance. Decreasing HFE expression by siRNA resulted in a 85% decrease in p16 expression in the neuroblastoma cells but not the astrocytoma cells. These data suggest a potential direct relationship between HFE and p16 that may be cell specific or mediated by different pathways in the different cell types. In conclusion, the C282Y HFE variant impacts the vulnerability of cancer cells to current treatment strategies apparently by increasing expression of p16. Although best known as a tumor suppressor, there are multiple reports that p16 is elevated in some forms of cancer. Given the frequency of the HFE gene variants, as high as 10% of the Caucasian population, these data provide compelling evidence that the C282Y HFE variant should be part of a pharmacogenetic strategy for evaluating treatment efficacy in cancer cells. Copyright © 2011 UICC.

  20. 5-Aza-2'-deoxycytidine protects against emphysema in mice via suppressing p16Ink4a expression in lung tissue

    Directory of Open Access Journals (Sweden)

    He ZH

    2017-10-01

    Full Text Available Zhi-Hui He,1 Yan Chen,2 Ping Chen,2 Sheng-Dong He,2 Hui-Hui Zeng,2 Ji-Ru Ye,2 Da Liu,2 Jun Cao3 1Intensive Care Unit, 2Department of Respiratory Medicine, Second Xiangya Hospital, Central South University, Changsha, 3Department of Respiratory Medicine, Hunan Provincial People’s Hospital, Changsha, China Background: There is a growing realization that COPD, or at least emphysema, involves several processes presenting in aging and cellular senescence. Endothelial progenitor cells (EPCs contribute to neovascularization and play an important role in the development of COPD. The gene for p16Ink4a is a major dominant senescence one. The aim of the present study was to observe changes in lung function, histomorphology of lung tissue, and expression of p16Ink4a in lung tissue and bone marrow-derived EPCs in emphysematous mice induced by cigarette-smoke extract (CSE, and further to search for a potential candidate agent protecting against emphysema induced by CSE. Materials and methods: An animal emphysema model was induced by intraperitoneal injection of CSE. 5-Aza-2'-deoxycytidine (5-Aza-CdR was administered to the emphysematous mice. Lung function and histomorphology of lung tissue were measured. The p16Ink4a protein and mRNA in EPCs and lung tissues were detected using Western blotting and quantitative reverse-transcription polymerase chain reaction, respectively. Results: CSE induced emphysema with increased p16Ink4a expression in lung tissue and bone marrow-derived EPCs. 5-Aza-CdR partly protected against emphysema, especially in the lung-morphology profile, and partly protest against the overexpression of p16Ink4a in EPCs and lung tissue induced by CSE. Conclusion: 5-Aza-CdR partly protected against emphysema in mice via suppressing p16Ink4a expression in EPCs and lung tissue. Keywords: 5-Aza-2'-deoxycytidine, cigarette smoke, emphysema, endothelial progenitor cells, p16Ink4a

  1. Up-regulation of expression and lack of 5' CpG island hypermethylation of p16 INK4a in HPV-positive cervical carcinomas

    International Nuclear Information System (INIS)

    Ivanova, Tatiana A; Golovina, Daria A; Zavalishina, Larisa E; Volgareva, Galina M; Katargin, Alexey N; Andreeva, Yulia Y; Frank, Georgy A; Kisseljov, Fjodor L; Kisseljova, Natalia P

    2007-01-01

    High risk type human papilloma viruses (HR-HPV) induce carcinomas of the uterine cervix by expressing viral oncogenes E6 and E7. Oncogene E7 of HR-HPV disrupts the pRb/E2F interaction, which negatively regulates the S phase entry. Expression of tumor suppressor p16 ink4a drastically increases in majority of HR-HPV associated carcinomas due to removal of pRb repression. The p16 ink4a overexpression is an indicator of an aberrant expression of viral oncogenes and may serve as a marker for early diagnostic of cervical cancer. On the other hand, in 25–57% of cervical carcinomas hypermethylation of the p16 INK4a promoter has been demonstrated using a methylation-specific PCR, MSP. To evaluate a potential usage of the p16 INK4a 5' CpG island hypermethylation as an indicator of tumor cell along with p16 ink4a overexpression, we analyzed the methylation status of p16 INK4a in cervical carcinomas Methylation status of p16 INK4a was analyzed by MSP and by bisulfite-modified DNA sequencing. The expression of p16 ink4a was analyzed by RT-PCR and by immunohistochemical technique. The extensive methylation within p16 INK4a 5' CpG island was not detected either in 13 primary cervical carcinomas or in 5 cancer cell lines by bisulfite-modified DNA sequencing (including those that were positive by MSP in our hands). The number and distribution of rare partially methylated CpG sites did not differ considerably in tumors and adjacent normal tissues. The levels of the p16 INK4a mRNA were increased in carcinomas compared to the normal tissues independently of the number of partially methylated CpGs within 5'CpG island. The transcriptional activation of p16 INK4a was accompanied by p16 ink4a cytoplasmic immunoreactivity in the majority of tumor cells and presence of a varied number of the p16 positive nuclei in different tumors. Hypermethylaion of the p16INK4a 5' CpG island is not a frequent event in HR-HPV-positive cervical carcinomas and cannot be an effective

  2. Screening for human papillomavirus in basaloid squamous carcinoma: utility of p16(INK4a), CISH, and PCR.

    Science.gov (United States)

    Winters, Ryan; Trotman, Winifred; Adamson, Christine S C; Rajendran, Vanitha; Tang, Alice; Elhosseiny, Abdelmonem; Evans, Mark F

    2011-06-01

    This study compares p16( INK4a) immunohistochemistry (IHC), HPV chromogenic in situ hybridization (ISH), and HPV polymerase chain reaction (PCR) genotyping for detection of HPV infection in basaloid squamous carcinoma (BSCC). A retrospective histopathological analysis of 40 BSCC from a single institution was carried out. p16 IHC, HPV DNA extraction and ISH, and HPV PCR genotyping were performed, and there was excellent agreement between all 3 methods of HPV detection. Analysis of variance yielded no significant differences between the results of the 3 tests ( P = .354) and Pearson product-moment correlation coefficients calculated for each pair of tests demonstrated direct correlation (r = .61 for PCR and IHC, r = .61 for PCR and ISH, and r = 1.00 for ISH and IHC). This supports the use of p16(INK4a) IHC as an initial screening tool for HPV infection in BSCC, while definitive evidence of HPV DNA can be sought subsequently with PCR or CISH.

  3. Implications of Genetic and Epigenetic Alterations of CDKN2A (p16INK4a in Cancer

    Directory of Open Access Journals (Sweden)

    Ran Zhao

    2016-06-01

    Full Text Available Aberrant gene silencing is highly associated with altered cell cycle regulation during carcinogenesis. In particular, silencing of the CDKN2A tumor suppressor gene, which encodes the p16INK4a protein, has a causal link with several different types of cancers. The p16INK4a protein plays an executional role in cell cycle and senescence through the regulation of the cyclin-dependent kinase (CDK 4/6 and cyclin D complexes. Several genetic and epigenetic aberrations of CDKN2A lead to enhanced tumorigenesis and metastasis with recurrence of cancer and poor prognosis. In these cases, the restoration of genetic and epigenetic reactivation of CDKN2A is a practical approach for the prevention and therapy of cancer. This review highlights the genetic status of CDKN2A as a prognostic and predictive biomarker in various cancers.

  4. Chemotherapy and Stem Cell Transplantation Increase p16INK4a Expression, a Biomarker of T-cell Aging

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    William A. Wood

    2016-09-01

    Full Text Available The expression of markers of cellular senescence increases exponentially in multiple tissues with aging. Age-related physiological changes may contribute to adverse outcomes in cancer survivors. To investigate the impact of high dose chemotherapy and stem cell transplantation on senescence markers in vivo, we collected blood and clinical data from a cohort of 63 patients undergoing hematopoietic cell transplantation. The expression of p16INK4a, a well-established senescence marker, was determined in T-cells before and 6 months after transplant. RNA sequencing was performed on paired samples from 8 patients pre- and post-cancer therapy. In patients undergoing allogeneic transplant, higher pre-transplant p16INK4a expression was associated with a greater number of prior cycles of chemotherapy received (p = 0.003, prior autologous transplantation (p = 0.01 and prior exposure to alkylating agents (p = 0.01. Transplantation was associated with a marked increase in p16INK4a expression 6 months following transplantation. Patients receiving autologous transplant experienced a larger increase in p16INK4a expression (3.1-fold increase, p = 0.002 than allogeneic transplant recipients (1.9-fold increase, p = 0.0004. RNA sequencing of T-cells pre- and post- autologous transplant or cytotoxic chemotherapy demonstrated increased expression of transcripts associated with cellular senescence and physiological aging. Cytotoxic chemotherapy, especially alkylating agents, and stem cell transplantation strongly accelerate expression of a biomarker of molecular aging in T-cells.

  5. Polymorphisms in promoter sequences of MDM2, p53, and p16INK4a genes in normal Japanese individuals

    Directory of Open Access Journals (Sweden)

    Yasuhito Ohsaka

    2010-01-01

    Full Text Available Research has been conducted to identify sequence polymorphisms of gene promoter regions in patients and control subjects, including normal individuals, and to determine the influence of these polymorphisms on transcriptional regulation in cells that express wild-type or mutant p53. In this study we isolated genomic DNA from whole blood of healthy Japanese individuals and sequenced the promoter regions of the MDM2, p53, and p16INK4a genes. We identified polymorphisms comprising 3 nucleotide substitutions at exon 1 and intron 1 regions of the MDM2 gene and 1 nucleotide insertion at a poly(C nucleotide position in the p53 gene. The Japanese individuals also exhibited p16INK4a polymorphisms at several positions, including position -191. Reporter gene analysis by using luciferase revealed that the polymorphisms of MDM2, p53, and p16INK4a differentially altered luciferase activities in several cell lines, including the Colo320DM, U251, and T98G cell lines expressing mutant p53. Our results indicate that the promoter sequences of these genes differ among normal Japanese individuals and that polymorphisms can alter gene transcription activity.

  6. The Contrasting Role of p16Ink4A Patterns of Expression in Neuroendocrine and Non-Neuroendocrine Lung Tumors: A Comprehensive Analysis with Clinicopathologic and Molecular Correlations.

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    Nicola Fusco

    Full Text Available Lung cancer encompasses a constellation of malignancies with no validated prognostic markers. p16Ink4A expression has been reported in different subtypes of lung cancers; however, its prognostic value is controversial. Here, we sought to investigate the clinical significance of p16Ink4A immunoexpression according to specific staining patterns and its operational implications. A total of 502 tumors, including 277 adenocarcinomas, 84 squamous cell carcinomas, 22 large cell carcinomas, 47 typical carcinoids, 12 atypical carcinoids, 28 large cell neuroendocrine carcinomas, and 32 small cell carcinomas were reviewed and subjected to immunohistochemical analysis for p16Ink4A and Ki67. The spectrum of p16Ink4A expression was annotated for each case as negative, sporadic, focal, or diffuse. Expression at immunohistochemical level showed intra-tumor homogeneity, regardless tumor histotype. Enrichments in cells expressing p16Ink4A were observed from lower- to higher-grade neuroendocrine malignancies, whereas a decrease was seen in poorly and undifferentiated non-neuroendocrine carcinomas. Tumor proliferation indices were higher in neuroendocrine tumors expressing p16Ink4A while non-neuroendocrine malignancies immunoreactive for p16Ink4A showed a decrease in Ki67-positive cells. Quantitative statistical analyses including each histotype and the p16Ink4A status confirmed the independent prognostic role of p16Ink4A expression, being a high-risk indicator in neuroendocrine tumors and a marker of good prognosis in non-neuroendocrine lung malignancies. In this study, we provide circumstantial evidence to suggest that the routinary assessment of p16Ink4A expression using a three-tiered scoring algorithm, even in a small biopsy, may constitute a reliable, reproducible, and cost-effective substrate for a more accurate risk stratification of each individual patient.

  7. Germline CDKN2A/P16INK4A mutations contribute to genetic determinism of sarcoma.

    Science.gov (United States)

    Jouenne, Fanélie; Chauvot de Beauchene, Isaure; Bollaert, Emeline; Avril, Marie-Françoise; Caron, Olivier; Ingster, Olivier; Lecesne, Axel; Benusiglio, Patrick; Terrier, Philippe; Caumette, Vincent; Pissaloux, Daniel; de la Fouchardière, Arnaud; Cabaret, Odile; N'Diaye, Birama; Velghe, Amélie; Bougeard, Gaelle; Mann, Graham J; Koscielny, Serge; Barrett, Jennifer H; Harland, Mark; Newton-Bishop, Julia; Gruis, Nelleke; Van Doorn, Remco; Gauthier-Villars, Marion; Pierron, Gaelle; Stoppa-Lyonnet, Dominique; Coupier, Isabelle; Guimbaud, Rosine; Delnatte, Capucine; Scoazec, Jean-Yves; Eggermont, Alexander M; Feunteun, Jean; Tchertanov, Luba; Demoulin, Jean-Baptiste; Frebourg, Thierry; Bressac-de Paillerets, Brigitte

    2017-09-01

    Sarcomas are rare mesenchymal malignancies whose pathogenesis is poorly understood; both environmental and genetic risk factors could contribute to their aetiology. We performed whole-exome sequencing (WES) in a familial aggregation of three individuals affected with soft-tissue sarcoma (STS) without TP53 mutation (Li-Fraumeni-like, LFL) and found a shared pathogenic mutation in CDKN2A tumour suppressor gene. We searched for individuals with sarcoma among 474 melanoma-prone families with a CDKN2A -/+ genotype and for CDKN2A mutations in 190 TP53 -negative LFL families where the index case was a sarcoma. Including the initial family, eight independent sarcoma cases carried a germline mutation in the CDKN2A /p16 INK4A gene. In five out of seven formalin-fixed paraffin-embedded sarcomas, heterozygosity was lost at germline CDKN2A mutations sites demonstrating complete loss of function. As sarcomas are rare in CDKN2A /p16 INK4A carriers, we searched in constitutional WES of nine carriers for potential modifying rare variants and identified three in platelet-derived growth factor receptor ( PDGFRA ) gene. Molecular modelling showed that two never-described variants could impact the PDGFRA extracellular domain structure. Germline mutations in CDKN2A /P16 INK4A , a gene known to predispose to hereditary melanoma, pancreatic cancer and tobacco-related cancers, account also for a subset of hereditary sarcoma. In addition, we identified PDGFRA as a candidate modifier gene. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  8. Efficient immortalization of primary human cells by p16INK4a-specific short hairpin RNA or Bmi-1, combined with introduction of hTERT.

    Science.gov (United States)

    Haga, Kei; Ohno, Shin-ichi; Yugawa, Takashi; Narisawa-Saito, Mako; Fujita, Masatoshi; Sakamoto, Michiie; Galloway, Denise A; Kiyono, Tohru

    2007-02-01

    Activation of telomerase is sufficient for immortalization of some types of human cells but additional factors may also be essential. It has been proposed that stress imposed by inadequate culture conditions induces senescence due to accumulation of p16(INK4a). Here, we present evidence that many human cell types undergo senescence by activation of the p16(INK4a)/Rb pathway, and that introduction of Bmi-1 can inhibit p16(INK4a) expression and extend the life span of human epithelial cells derived from skin, mammary gland and lung. Introduction of p16(INK4a)-specific short hairpin RNA, as well as Bmi-1, suppressed p16(INK4a) expression in human mammary epithelial cells without promoter methylation, and extended their life span. Subsequent introduction of hTERT, the telomerase catalytic subunit, into cells with low p16(INK4a) levels resulted in efficient immortalization of three cell types without crisis or growth arrest. The majority of the human mammary epithelial cells thus immortalized showed almost normal ploidy as judged by G-banding and spectral karyotyping analysis. Our data suggest that inhibition of p16(INK4a) and introduction of hTERT can immortalize many human cell types with little chromosomal instability.

  9. Aberrant Expression of ID2 protein and its correlation with EBV-LMP1 and P16(INK4A) in Classical Hodgkin Lymphoma in China

    International Nuclear Information System (INIS)

    Zhao, Po; Lu, Yali; Liu, Lin; Zhong, Mei

    2008-01-01

    The relationships between the expression of ID2, EBV-LMP1 and P16(INK4A) in Chinese classical Hodgkin lymphoma are unknown and need exploring. Samples of classical Hodgkin lymphoma from 60 Chinese patients were analyzed for the expression of ID2, EBV-LMP1 and p16(INK4A) proteins by immunohistochemistry. ID2 protein was expressed in 83.3% of this group of classical Hodgkin lymphoma, staining strongly in both cytoplasm and nucleus of the Hodgkin and Reed-Sternberg (HRS) cells. EBV-LMP1 and P16(INK4A) were overexpressed in 85.0% and 71.7% of Hodgkin lymphoma, respectively. EBV-LMP1 was noted in the cytoplasm, membrane and nucleus of HRS cells; P16(INK4A) was in the nucleus and cytoplasm. Microscopically, ID2, EBV-LMP1 and P16(INK4A) staining distinguished the HRS cells from the complex background of lymphocytes. ID2 was positively correlated with EBV-LMP1(P < 0.01), but P16(INK4A) was inversely related to EBV-LMP1 (P < 0.05). It is suggested that ID2, EBV-LMP1 and P16(INK4A) could play an important role in the evolution of classical Hodgkin lymphoma, and be considered as potential adjunct markers to identify HRS cells in diagnosis

  10. P16INK4a Positive Cells in Human Skin Are Indicative of Local Elastic Fiber Morphology, Facial Wrinkling, and Perceived Age

    DEFF Research Database (Denmark)

    Waaijer, Mariëtte E C; Gunn, David A; Adams, Peter D

    2016-01-01

    Senescent cells are more prevalent in aged human skin compared to young, but evidence that senescent cells are linked to other biomarkers of aging is scarce. We counted cells positive for the tumor suppressor and senescence associated protein p16INK4a in sun-protected upper-inner arm skin biopsies...... wrinkles and a higher perceived age. Participants in the lowest tertile of epidermal p16INK4a counts looked 3 years younger than those in the highest tertile, independently of chronological age and elastic fiber morphology. In conclusion, p16INK4a positive cell numbers in sun-protected human arm skin...

  11. Up-regulation of expression and lack of 5' CpG island hypermethylation of p16 INK4a in HPV-positive cervical carcinomas

    Directory of Open Access Journals (Sweden)

    Frank Georgy A

    2007-03-01

    Full Text Available Abstract Background High risk type human papilloma viruses (HR-HPV induce carcinomas of the uterine cervix by expressing viral oncogenes E6 and E7. Oncogene E7 of HR-HPV disrupts the pRb/E2F interaction, which negatively regulates the S phase entry. Expression of tumor suppressor p16ink4a drastically increases in majority of HR-HPV associated carcinomas due to removal of pRb repression. The p16ink4a overexpression is an indicator of an aberrant expression of viral oncogenes and may serve as a marker for early diagnostic of cervical cancer. On the other hand, in 25–57% of cervical carcinomas hypermethylation of the p16 INK4a promoter has been demonstrated using a methylation-specific PCR, MSP. To evaluate a potential usage of the p16 INK4a 5' CpG island hypermethylation as an indicator of tumor cell along with p16ink4a overexpression, we analyzed the methylation status of p16 INK4a in cervical carcinomas Methods Methylation status of p16 INK4a was analyzed by MSP and by bisulfite-modified DNA sequencing. The expression of p16ink4a was analyzed by RT-PCR and by immunohistochemical technique. Results The extensive methylation within p16 INK4a 5' CpG island was not detected either in 13 primary cervical carcinomas or in 5 cancer cell lines by bisulfite-modified DNA sequencing (including those that were positive by MSP in our hands. The number and distribution of rare partially methylated CpG sites did not differ considerably in tumors and adjacent normal tissues. The levels of the p16 INK4a mRNA were increased in carcinomas compared to the normal tissues independently of the number of partially methylated CpGs within 5'CpG island. The transcriptional activation of p16 INK4a was accompanied by p16ink4a cytoplasmic immunoreactivity in the majority of tumor cells and presence of a varied number of the p16 positive nuclei in different tumors. Conclusion Hypermethylaion of the p16INK4a 5' CpG island is not a frequent event in HR-HPV-positive cervical

  12. EVALUATION OF P16INK4A PROTEIN AS A BIOMARKER FOR CERVICAL INTRAEPITHELIAL NEOPLASIA AND SQUAMOUS CELL CARCINOMA OF THE UTERINE CERVIX

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    Biljana Đorđević

    2011-06-01

    Full Text Available The association of human papilloma virus (HPV infection and cervical intraepithelial neoplasia (CIN is well known. Interaction of HPV proteins with cellular regulatory proteins leads to up regulation of p16INK4A. The aim of this study was to evaluate p16INK4A protein as a biomarker for CIN lesions and squamous cell carcinoma on biopsy specimens of patients who underwent biopsy of the uterine cervix due to abnormal cytological finding.The authors analyzed biopsies from 50 patients with CIN and invasive squamous cell carcinoma of the uterine cervix. Expression of p16INK4A in CIN and invasive squamous cell carcinoma was immunohistochemically analyzed by using monoclonal anti-p16INK4A antibody.A total of 50 patients with CIN and invasive squamous cell carcinoma of the uterine cervix (mean age 40.2±11.5 years, range 20-74 years were analyzed. CIN I lesions were found in 27 (54%, CIN II/CIN III lesions in 9 (18%, and invasive squamous cell carcinoma in 14 (28% patients. Differences in the expression of p16INK4A between CIN I, CIN II/CIN III and squamous cell carcinoma were statistically significant (p<0.0001. Expression of p16INK4A showed low sensitivity (7%, specificity (8%, positive predictive value (8%, and negative predictive value (7% for CIN I. Sensitivity, specificity, positive predictive value, and negative predictive value of p16INK4A were 78%, 61%, 30%, and 93% for CIN II/CIN III, and 100%, 75%, 61%, and 100% for squamous cell carcinoma, respectively.Results of this study suggest that p16INK4A protein may be a sensitive biomarker for CIN II/CIN III lesions and invasive squamous cell carcinoma of the uterine cervix.

  13. Tumor suppressor p16 INK4a: Downregulation of galectin-3, an endogenous competitor of the pro-anoikis effector galectin-1, in a pancreatic carcinoma model.

    Science.gov (United States)

    Sanchez-Ruderisch, Hugo; Fischer, Christian; Detjen, Katharina M; Welzel, Martina; Wimmel, Anja; Manning, Joachim C; André, Sabine; Gabius, Hans-Joachim

    2010-09-01

    The tumor suppressor p16(INK4a) has functions beyond cell-cycle control via cyclin-dependent kinases. A coordinated remodeling of N- and O-glycosylation, and an increase in the presentation of the endogenous lectin galectin-1 sensing these changes on the surface of p16(INK4a)-expressing pancreatic carcinoma cells (Capan-1), lead to potent pro-anoikis signals. We show that the p16(INK4a)-dependent impact on growth-regulatory lectins is not limited to galectin-1, but also concerns galectin-3. By monitoring its expression in relation to p16(INK4a) status, as well as running anoikis assays with galectin-3 and cell transfectants with up- or downregulated lectin expression, a negative correlation between anoikis and the presence of this lectin was established. Nuclear run-off and northern blotting experiments revealed an effect of the presence of p16(INK4a) on steady-state levels of galectin-3-specific mRNA that differed from decreasing the transcriptional rate. On the cell surface, galectin-3 interferes with galectin-1, which initiates signaling toward its pro-anoikis activity via caspase-8 activation. The detected opposite effects of p16(INK4a) at the levels of growth-regulatory galectins-1 and -3 shift the status markedly towards the galectin-1-dependent pro-anoikis activity. A previously undescribed orchestrated fine-tuning of this effector system by a tumor suppressor is discovered.

  14. Dysregulation of the Bmi-1/p16Ink4a pathway provokes an aging-associated decline of submandibular gland function

    Science.gov (United States)

    Yamakoshi, Kimi; Katano, Satoshi; Iida, Mayu; Kimura, Hiromi; Okuma, Atsushi; Ikemoto-Uezumi, Madoka; Ohtani, Naoko; Hara, Eiji; Maruyama, Mitsuo

    2015-01-01

    Bmi-1 prevents stem cell aging, at least partly, by blocking expression of the cyclin-dependent kinase inhibitor p16Ink4a. Therefore, dysregulation of the Bmi-1/p16Ink4a pathway is considered key to the loss of tissue homeostasis and development of associated degenerative diseases during aging. However, because Bmi-1 knockout (KO) mice die within 20 weeks after birth, it is difficult to determine exactly where and when dysregulation of the Bmi-1/p16Ink4a pathway occurs during aging in vivo. Using real-time in vivo imaging of p16Ink4a expression in Bmi-1-KO mice, we uncovered a novel function of the Bmi-1/p16Ink4a pathway in controlling homeostasis of the submandibular glands (SMGs), which secrete saliva into the oral cavity. This pathway is dysregulated during aging in vivo, leading to induction of p16Ink4a expression and subsequent declined SMG function. These findings will advance our understanding of the molecular mechanisms underlying the aging-related decline of SMG function and associated salivary gland hypofunction, which is particularly problematic among the elderly. PMID:25832744

  15. p16INK4a immunostaining in cytological and histological specimens from the uterine cervix: a systematic review and meta-analysis

    Science.gov (United States)

    Tsoumpou, I; Arbyn, M; Kyrgiou, M; Wentzensen, N; Koliopoulos, G; Martin-Hirsch, P; Paraskevaidis, E

    2009-01-01

    Background P16INK4a is a biomarker for transforming HPV infections that could act as an adjunct to current cytological and histological assessment of cervical smears and biopsies, allowing the identification of those women with ambiguous results that require referral to colposcopy and potentially treatment. Material and Methods We conducted a systematic review of all studies that evaluated the use of p16INK4a in cytological or histological specimens from the uterine cervix. We also estimated the mean proportion of samples that were positive for p16INK4a in cytology and histology, stratified by the grade of the lesion. Results Sixty-one studies were included. The proportion of cervical smears overexpressing p16INK4a increased with the severity of cytological abnormality. Among normal smears, only 12% (95% CI: 7–17%) were positive for the biomarker compared to 45% of ASCUS and LSIL (95% CI: 35–54% and 37– 57% respectively) and 89% of HSIL smears (95% CI: 84–95%). Similarly, in histology only 2% of normal biopsies (95% CI: 0.4– 30%) and 38% of CIN1 (95% CI: 23– 53%) showed diffuse staining for p16INK4a compared to 68% of CIN2 (95% CI: 44– 92%) and 82% of CIN3 (95% CI: 72– 92%). Conclusion Although there is good evidence that p16INK4a immunostaining correlates with the severity of cytological/histological abnormalities, the reproducibility is limited due to insufficiently standardized interpretation of the immunostaining. Therefore, a consensus needs to be reached regarding the evaluation of p16INK4a staining and the biomarker needs to be evaluated in various clinical settings addressing specific clinical questions. PMID:19261387

  16. Clinical and prognosis value of the CIMP status combined with MLH1 or p16 INK4a methylation in colorectal cancer.

    Science.gov (United States)

    Saadallah-Kallel, Amana; Abdelmaksoud-Dammak, Rania; Triki, Mouna; Charfi, Slim; Khabir, Abdelmajid; Sallemi-Boudawara, Tahia; Mokdad-Gargouri, Raja

    2017-08-01

    Aberrant DNA methylation of CpG islands occurred frequently in CRC and associated with transcriptional silencing of key genes. In this study, the CIMP combined with MLH1 or p16 INK4a methylation status was determined in CRC patients and correlated with clinicopathological parameters and overall survival. Our data showed that CIMP+ CRCs were identified in 32.9% of cases and that CACNAG1 is the most frequently methylated promoter. When we combined the CIMP with the MLH1 or the p16 INK4a methylation status, we found that CIMP-/MLH1-U (37.8%) and CIMP-/p16 INK4a -U (35.4%) tumors were the most frequent among the four subtypes. Statistical analysis showed that tumor location, lymphovascular invasion, TNM stage, and MSI differed among the group of patients. Kaplan-Meier analyses revealed differences in overall survival according to the CIMP combined with MLH1 or p16 INK4a methylation status. In a multivariate analysis, CIMP/MLH1 and CIMP/p16 INK4a methylation statuses were predictive of prognosis, and the OS was longer for patients with tumors CIMP-/MLH1-M, as well as CIMP-/p16 INK4a -M. Furthermore, DNMT1 is significantly overexpressed in tumors than in normal tissues as well as in CIMP+ than CIMP- tumors. Our results suggest that tumor classification based on the CIMP status combined with MLH1 or p16 INK4a methylation is useful to predict prognosis in CRC patients.

  17. [Sorting role of p16(INK4a)/Ki-67 double immunostaining in the cervical cytology specimens of ASCUS and LSIL cases].

    Science.gov (United States)

    Yu, J; Zhu, H T; Zhao, J J; Su, J Z; Xia, Y D

    2017-05-08

    Objective: To investigate the sorting effect of p16(INK4a)/Ki-67 double immunostaining method in patients with atypical squamous cells of undetermined significance (ASCUS) or low-grade squamous intraepithelial lesion (LSIL) cytology results. Methods: Four-hundred and twenty cases collected during April 2014 to February 2015 of cervical cytology of ASCUS ( n =318) and LSIL ( n =102) were selected, and residual liquid-based cytology specimens were used for p16(INK4a)/Ki-67 double immunostaining. The sensitivity and specificity of the detection of cervical precancerous lesions and cervical cancer were calculated, and the results were compared with high risk HPV. Taking histological follow-up as the gold standard, the test was considered positive when at least one cell exhibited p16(INK4a)/Ki-67 co-staining, without requirement of adjunct morphologic interpretation of positive cells. Results: Further screening CIN2+ in cytology ASCUS and LSIL group , the sensitivity of p16(INK4a)/Ki-67 double immunostaining was slightly lower than high risk HPV (84.2% vs . 94.7%), while the specificity was higher (84.0% vs . 53.9%). For ASCUS patients, the sensitivity of p16(INK4a)/Ki-67 double immunostaining and high risk HPV was 82.6% and 91.3%, and the specificity was 88.8% and 63.7%, respectively. For LSIL patients, the sensitivity of p16(INK4a)/Ki-67 double immunostaining and high risk HPV was 86.7% and 100.0%, and the specificity was 67.8% and 20.7%, respectively. For patients younger and older than 30 years, specificity of p16(INK4a)/Ki-67 double immunostaining was both higher than that of high risk HPV (80.8% vs . 42.3%; 84.6% vs . 56.9%). Conclusions: p16(INK4a)/Ki-67 double immunostaining can effectively identify the high risk population in ASCUS or LSIL, with higher specificity than high risk HPV test. p16(INK4a)/Ki-67 double immunostaining may benefit patients younger than 30 years of age as a preliminary or potential cytology-combining screening tool.

  18. Elevated p16ink4a Expression in Human Labial Salivary Glands as a Potential Correlate of Cognitive Aging in Late Midlife.

    Directory of Open Access Journals (Sweden)

    Christiane Elisabeth Sørensen

    Full Text Available The cell-cycle inhibitor and tumor suppressor cyclin dependent kinase inhibitor, p16ink4a, is one of the two gene products of the ink4a/ARF (cdkn2a locus on chromosome 9q21. Up-regulation of p16ink4a has been linked to cellular senescence, and findings from studies on different mammalian tissues suggest that p16ink4a may be a biomarker of organismal versus chronological age.The aim of this study was to examine the immunolocalization pattern of p16ink4a in human labial salivary gland (LSG tissue, and to analyze whether its expression level in LSGs is a peripheral correlate of cognitive decline in late midlife.The present study was a part of a study of causes and predictors of cognitive decline in middle-aged men in a Danish birth cohort. It is based on data from 181 male participants from the Danish Metropolit birth cohort, born in 1953, who were examined for age-associated alterations in cognition, dental health, and morphological and autonomic innervation characteristics of the LSGs. The participants were allocated to two groups based on the relative change in cognitive performance from young adulthood to late midlife. LSG biopsies were analyzed by qRT-PCR for the expression level of p16ink4a. Immunohistochemistry was performed on formalin-fixed, paraffin-embedded sections of LSGs.p16ink4a immunoreactivity was observed in LSG ductal, myoepithelial, and stromal cells, but not in acinar cells. The mean relative expression of p16ink4a in LSGs was higher in the group of participants with decline in cognitive performance. A logistic regression analysis revealed that the relative p16 expression was predictive of the participant's group assignment. A negative correlation was found between relative p16ink4a expression and the participant's standardized regression residuals from early adulthood to late midlife cognitive performance scores.p16ink4a expression in human LSGs may constitute a potential peripheral correlate of cognitive decline. Human labial

  19. p16INK4A, p53, EGFR expression and KRAS mutation status in squamous cell cancers of the anus: Correlation with outcomes following chemo-radiotherapy

    International Nuclear Information System (INIS)

    Gilbert, Duncan C; Williams, Anthony; Allan, Kimberley; Stokoe, Joanna; Jackson, Tim; Linsdall, Suzanne; Bailey, Charles MH; Summers, Jeff

    2013-01-01

    Background and Purpose: Squamous cell carcinomas of the anal canal are associated with infection with Human Papilloma Viruses (HPVs). Chemo-radiotherapy (CRT) gives 70% 3-year relapse-free survival. Improved predictive markers and therapeutic options are required. Methods: Tumours from 153 patients treated with radical chemo-radiotherapy (50.4 Gy in 28 with concurrent Mitomycin and 5-Fluorouracil between 2004 and 2009) were retrieved and immunohistochemistry performed for p16 INK4A , p53 and EGFR and correlated with outcome. Primary and relapsed samples were analysed for mutations in KRAS. Results: 137/153 (89.5%) stained moderately or strongly for p16 INK4A . p16 INK4A correlated strongly with outcome. 37/137 patients demonstrating moderate/strong p16 INK4A expression relapsed (27.0%), as opposed to 10/16 (62.5%) with absent/weak staining (log rank test p INK4A negative tumours were more frequent in men. p16 INK4A negative patients had significantly worse overall survival (p INK4A is strongly associated with relapse in SCC of the anus and identifies patients with very poor rates of relapse-free and overall survival. Primary and recurrent anal cancer expresses wild type KRAS, unaffected by treatment, supporting trials targeting EGFR in poor risk/recurrent anal cancer

  20. Influence of human papillomavirus and p16INK4a on treatment outcome of patients with anal cancer

    International Nuclear Information System (INIS)

    Koerber, Stefan Alexander; Schoneweg, Clara; Slynko, Alla; Krug, David; Haefner, Matthias F.; Herfarth, Klaus; Debus, Juergen; Sterzing, Florian; Knebel Doeberitz, Magnus von

    2014-01-01

    Background: The purpose of this study was to evaluate HPV-DNA and p16 INK4a (p16) expression as prognostic markers for outcome in patients with anal cancer. Methods: From January 2000 to December 2011 a cohort of 105 anal cancer patients was treated with definitive chemoradiation at our institution. Tumor biopsies from 90 patients were analyzed for HPV-DNA by polymerase chain reaction and for p16 expression by immunohistochemistry. Results: Median follow-up was 48.6 months (range 2.8–169.1 months). HPV-DNA or p16-expression was found in 75 anal cancers each (83.3%), concordance was detectable in 70 tumors (77.8%). Significantly improved overall survival (OS) [77.1% vs. 51.4%, p = 0.005], progression-free survival (PFS) [64.0% vs. 35.0%, p < 0.001] and improved local control [81.0% vs. 55.9%, p = 0.023] was found for concomitant HPV- and p16-positive anal carcinomas (cHPPAC) in univariate analysis. Multivariate analysis showed better OS [p = 0.015] and PFS [p = 0.002] for cHPPAC. Conclusion: The combination of HPV-DNA and p16 can be used as an independent prognostic parameter in anal cancer patients

  1. Aging of mice is associated with p16(Ink4a)- and β-galactosidase-positive macrophage accumulation that can be induced in young mice by senescent cells.

    Science.gov (United States)

    Hall, Brandon M; Balan, Vitaly; Gleiberman, Anatoli S; Strom, Evguenia; Krasnov, Peter; Virtuoso, Lauren P; Rydkina, Elena; Vujcic, Slavoljub; Balan, Karina; Gitlin, Ilya; Leonova, Katerina; Polinsky, Alexander; Chernova, Olga B; Gudkov, Andrei V

    2016-07-01

    Senescent cells (SCs) have been considered a source of age-related chronic sterile systemic inflammation and a target for anti-aging therapies. To understand mechanisms controlling the amount of SCs, we analyzed the phenomenon of rapid clearance of human senescent fibroblasts implanted into SCID mice, which can be overcome when SCs were embedded into alginate beads preventing them from immunocyte attack. To identify putative SC killers, we analyzed the content of cell populations in lavage and capsules formed around the SC-containing beads. One of the major cell types attracted by secretory factors of SCs was a subpopulation of macrophages characterized by p16(Ink4a) gene expression and β-galactosidase activity at pH6.0 (β-gal(pH6)), thus resembling SCs. Consistently, mice with p16(Ink4a) promoter-driven luciferase, developed bright luminescence of their peritoneal cavity within two weeks following implantation of SCs embedded in alginate beads. p16(Ink4a)/β-gal(pH6)-expressing cells had surface biomarkers of macrophages F4/80 and were sensitive to liposomal clodronate used for the selective killing of cells capable of phagocytosis. At the same time, clodronate failed to kill bona fide SCs generated in vitro by genotoxic stress. Old mice with elevated proportion of p16(Ink4a)/β-gal(pH6)-positive cells in their tissues demonstrated reduction of both following systemic clodronate treatment, indicating that a significant proportion of cells previously considered to be SCs are actually a subclass of macrophages. These observations point at a significant role of p16(Ink4a)/β-gal(pH6)-positive macrophages in aging, which previously was attributed solely to SCs. They require re-interpretation of the mechanisms underlying rejuvenating effects following eradication of p16(Ink4a)/β-gal(pH6)-positive cells and reconsideration of potential cellular target for anti-aging treatment.

  2. Association of antibody to E2 protein of human papillomavirus and p16INK4A with progression of HPV-infected cervical lesions.

    Science.gov (United States)

    Chuerduangphui, Jureeporn; Pientong, Chamsai; Swangphon, Piyawut; Luanratanakorn, Sanguanchoke; Sangkomkamhang, Ussanee; Tungsiriwattana, Thumwadee; Kleebkaow, Pilaiwan; Burassakarn, Ati; Ekalaksananan, Tipaya

    2018-05-09

    Human papillomavirus (HPV) E2 and L1 proteins are expressed in cervical cells during the lytic stage of infection. Overexpression of p16 INK4A is a biomarker of HPV-associated cervical neoplasia. This study investigated antibodies to HPV16 E2, HPV16 L1, and p16 INK4A in sera from women with no squamous intraepithelial lesion (No-SIL) of the cervix, low-grade SIL, high-grade SIL, and cervical squamous cell carcinoma (SCC). HPV DNA was detected by polymerase chain reaction. Anti-E2, -L1, and -p16 INK4A antibodies in sera were determined by western blot. Among 116 samples, 69 (60%) were HPV DNA-positive. Percentages seropositive for anti-E2, -L1, and -p16 INK4A antibodies were 39.6, 22.4, and 23.3%, respectively. Anti-E2 antibody was significantly correlated with HPV DNA-positive cases. Eighty-seven women (75%) were regarded as infected with HPV, having at least one positive result from HPV DNA, L1, or E2 antibody. Antibody to p16 INK4A was associated with HPV infection (odds = 5.444, 95% CI 1.203-24.629, P = 0.028) and precancerous cervical lesions (odds = 5.132, 95% CI 1.604-16.415, P = 0.006). Interestingly, the concurrent detection of anti-E2 and -p16 INK4A antibodies was significantly associated with HPV infection (odds = 1.382, 95% CI 1.228-1.555, P = 0.044). These antibodies might be good candidate biomarkers for monitoring HPV-associated cervical lesion development to cancer.

  3. Immunohistochemical characteristic of expression levels of Kі-67, p16INK4a, HPV16 in cervical intraepithelial neoplasia and cervical cancer

    Directory of Open Access Journals (Sweden)

    V. A. Tumanskiy

    2017-08-01

    Full Text Available Squamous cervical cancer (SCC is a common tumor in women, which is preceded by the series of pathological processes, among which the key role is played by cervical intraepithelial neoplasia (CIN. Aim. To study the characteristics of immunohistochemical (IHC expression of Ki-67, p16INK4a, HPV16 in squamous cervical epithelium (SCE with dysplastic changes of varying degree (CIN I–III and also in the tumor cells of SCC. Materials and methods. Pathohistological and IHC studies of uterine cervix biopsies from 53 patients (the age ranged from 18 to 45 years were performed. Results. It was found that SCE with CIN I is characterized by the low Ki-67 expression level (Me = 17.87 % (13.76, 22.44 and the extremely low p16INK4a expression level (Me = 0.00 CUOD (0.00; 29.64. The proportion of HPV16-positive patients with CIN I is 27.27 %. CIN II is characterized by the average proliferation level in SCE (Me = 44.96 % (34.91, 55.41 and the moderate p16INK4a expression level (Me = 75.71 CUOD (51.24, 82, 41. The proportion of HPV16-positive patients with CIN II is 71.43 %. CIN III is characterized by the high proliferation level (Me = 74.62 % (68.50, 84.67 and by the high p16INK4a expression level of in SCE (Me = 117.47 CUOD (95.38, 123, 93; the proportion of HPV16-positive patients with CIN III is 77.78%. In all the patients with SСС, nuclear and cytoplasmic expression of HPV16 was detected in the tumor cells. High expression levels of Ki-67 and p16INK4a were detected in the tumor cells. There are direct correlations between the expression levels of Ki-67, p16INK4a, HPV16 and CIN degree. Conclusions. These data indicate that the expression levels of Ki-67, p16INK4a and HPV16 increase with the increasing of CIN grade. The absence of statistically significant differences between the expression levels of Ki-67, p16INK4a and HPV16 in CIN III and the same levels in the tumor cells of SCC indicates that these markers cannot be used for differential diagnosis

  4. Simulation of Different Truncated p16INK4a Forms and In Silico Study of Interaction with Cdk4

    Directory of Open Access Journals (Sweden)

    Najmeh Fahham

    2009-01-01

    Full Text Available Protein-protein interactions studies can greatly increase the amount of structural and functional information pertaining to biologically active molecules and processes. The information obtained from such studies can lead to design and application of new modification in order to obtain a desired bioactivity. Many application packages and servers performing docking, such as HEX, DOT, AUTODOCK, and ZDOCK are now available for predicting the lowest free energy state of a protein complex. In this study, we have focused on cyclin-dependent kinase 4 (Cdk4, a key molecule in the regulation of cell cycle progression at the G1-S phase restriction point and p16INK4a, a tumor suppressor which inhibits Cdk4 activity. Truncated structures were created to find the more critical regions of p16 for interaction. The tertiary structures were determined by ProSAL, GENO3D Web Server. We evaluated their interactions with Cdk4 using two docking systems, HEX 4.5 and DOT 1. Calculations were performed on a high-speed computer. Minimizations and visualizations were carried out by PdbViewer 3.7. Considering shape and shape/electrostatic total energy, structures containing ANK II, III and IV motifs that lack the N-terminal region of the full length p16 molecule showed the best fi t complexes among the p16 truncated forms. The free energies were compatible with that of p16 full length original form, the full length. It seems that the N-terminal of the molecule is not crucial for the interaction since the truncated structure containing only this region did not show a good total energy.

  5. Protein p 16INK4A expression in cervical intraepithelial neoplasia and invasive squamous cell carcinoma of uterine cervix

    Directory of Open Access Journals (Sweden)

    Gupta Ruchi

    2010-01-01

    Full Text Available The association of human papilloma virus (HPV infection and cervical intraepithelial neoplasia (CIN is well recognized. Interaction of HPV oncogenic proteins with cellular regulatory proteins leads to up regulation of p16 INK4A , a CDK inhibitor, which is a biomarker for HPV infection. We investigated p16 expression in CIN and invasive squamous cell carcinoma (SCC which has not been reported in the Indian population previously. Materials and Methods: Retrospective analysis of 100 cases with 20 cases each of histologically normal cervical epithelium, CIN1, 2, 3 and invasive SCC for p16 expression was performed by immunohistochemistry using commercially available mouse monoclonal antibody to p16 (clone 6H12. Statistical Analysis: For differences in expression among groups, statistical analysis was carried out using ANOVA and post hoc test of Scheffe. Results: p16 immunoreactivity was found to be both nuclear and/or cytoplasmic. The normal cervical epithelium was predominantly negative for p16 (18/20. There was a progressive increase of p16 expression with the grade of CIN. In CIN 1, two cases (20% showed nuclear and nucleocytoplasmic positivity respectively. In contrast, diffuse strong nuclear or nucleocytoplasmic expression was observed in 45 and 55% cases of CIN 2 and CIN 3 respectively. All except one squamous cell carcinoma stained strongly positive for p16. The difference in expression between CIN 2/3 and SCC versus normal cervix was found highly significant (p is equal to 0.008 and p less than 0.001. Conclusions: p16 expression correlates excellently with the grade of CIN and is a sensitive marker of cervical intraepithelial neoplasia.

  6. Stathmin 1 and p16(INK4A) are sensitive adjunct biomarkers for serous tubal intraepithelial carcinoma.

    Science.gov (United States)

    Novak, Marián; Lester, Jenny; Karst, Alison M; Parkash, Vinita; Hirsch, Michelle S; Crum, Christopher P; Karlan, Beth Y; Drapkin, Ronny

    2015-10-01

    To credential Stathmin 1 (STMN1) and p16(INK4A) (p16) as adjunct markers for the diagnosis of serous tubal intraepithelial carcinoma (STIC), and to compare STMN1 and p16 expression in p53-positive and p53-negative STIC and invasive high-grade serous carcinoma (HGSC). Immunohistochemistry (IHC) was used to examine STMN1 and p16 expression in fallopian tube specimens (n=31) containing p53-positive and p53-negative STICs, invasive HGSCs, and morphologically normal FTE (fallopian tube epithelium). STMN1 and p16 expression was scored semiquantitatively by four individuals. The semiquantitative scores were dichotomized, and reported as positive or negative. Pooled siRNA was used to knockdown p53 in a panel of cell lines derived from immortalized FTE and HGSC. STMN1 and p16 were expressed in the majority of p53-positive and p53-negative STICs and concomitant invasive HGSCs, but only scattered positive cells were present in morphologically normal FTE. Both proteins were expressed consistently across multiple STICs from the same patient and in concomitant invasive HGSC. Knockdown of p53 in immortalized FTE cells and in four HGSC-derived cell lines expressing different missense p53 mutations did not affect STMN1 protein levels. This study demonstrates that STMN1 and p16 are sensitive and specific adjunct biomarkers that, when used with p53 and Ki-67, improve the diagnostic accuracy of STIC. The addition of STMN1 and p16 helps to compensate for practical limitations of p53 and Ki-67 that complicate the diagnosis in up to one third of STICs. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Stathmin 1 and p16INK4A are sensitive adjunct biomarkers for serous tubal intraepithelial carcinoma

    Science.gov (United States)

    Novak, Marián; Lester, Jenny; Karst, Alison M.; Parkash, Vinita; Hirsch, Michelle S.; Crum, Christopher P.; Karlan, Beth Y.

    2015-01-01

    Objective To credential Stathmin 1 (STMN1) and p16INK4A (p16) as adjunct markers for the diagnosis of serous tubal intraepithelial carcinoma (STIC), and to compare STMN1 and p16 expression in p53-positive and p53-negative STIC and invasive high-grade serous carcinoma (HGSC). Methods Immunohistochemistry (IHC) was used to examine STMN1 and p16 expression in fallopian tube specimens (n=31) containing p53-positive and p53-negative STICs, invasive HGSCs, and morphologically normal FTE (fallopian tube epithelium). STMN1 and p16 expression was scored semiquantitatively by four individuals. The semiquantitative scores were dichotomized, and reported as positive or negative. Pooled siRNA was used to knockdown p53 in a panel of cell lines derived from immortalized FTE and HGSC. Results STMN1 and p16 were expressed in the majority of p53-positive and p53-negative STICs and concomitant invasive HGSCs, but only scattered positive cells were positive in morphologically normal FTE. Both proteins were expressed consistently across multiple STICs from the same patient and in concomitant invasive HGSC. Knockdown of p53 in immortalized FTE cells and in four HGSC-derived cell lines expressing different missense p53 mutations did not affect STMN1 protein levels. Conclusions This study demonstrates that STMN1 and p16 are sensitive and specific adjunct biomarkers that, when used with p53 and Ki-67, improve the diagnostic accuracy of STIC. The addition of STMN1 and p16 helps to compensate for practical limitations of p53 and Ki-67 that complicate the diagnosis in up to one third of STICs. PMID:26206555

  8. Elevated p16ink4a Expression in Human Labial Salivary Glands as a Potential Correlate of Cognitive Aging in Late Midlife

    DEFF Research Database (Denmark)

    Sørensen, Christiane Elisabeth; Tritsaris, Katerina; Reibel, Jesper

    2016-01-01

    BACKGROUND: The cell-cycle inhibitor and tumor suppressor cyclin dependent kinase inhibitor, p16ink4a, is one of the two gene products of the ink4a/ARF (cdkn2a) locus on chromosome 9q21. Up-regulation of p16ink4a has been linked to cellular senescence, and findings from studies on different...... mammalian tissues suggest that p16ink4a may be a biomarker of organismal versus chronological age. OBJECTIVE: The aim of this study was to examine the immunolocalization pattern of p16ink4a in human labial salivary gland (LSG) tissue, and to analyze whether its expression level in LSGs is a peripheral...... correlate of cognitive decline in late midlife. METHODS: The present study was a part of a study of causes and predictors of cognitive decline in middle-aged men in a Danish birth cohort. It is based on data from 181 male participants from the Danish Metropolit birth cohort, born in 1953, who were examined...

  9. Survey of familial glioma and role of germline p16INK4A/p14ARF and p53 mutation

    DEFF Research Database (Denmark)

    Robertson, Lindsay B; Armstrong, Georgina N; Olver, Bianca D

    2010-01-01

    There is increasing recognition of familial propensity to glioma as a distinct clinical entity beyond a few rare syndromes; however its genetic basis is poorly understood. The role of p16(INK4A)/p14(ARF) and p53 mutations in sporadic glioma provides a strong rationale for investigating germline m...

  10. Deregulated expression of p16INK4a and p53 pathway members in benign and malignant myoepithelial tumours of the salivary glands

    NARCIS (Netherlands)

    Vékony, H.; Röser, K.; Löning, T.; Raaphorst, F.M.; Leemans, C.R.; van der Waal, I.; Bloemena, E.

    2008-01-01

    Aims: Myoepithelial salivary gland tumours are uncommon and follow an unpredictable biological course. The aim was to examine their molecular background to acquire a better understanding of their clinical behaviour. Methods and results: Expression of protein (E2F1, p16INK4a, p53, cyclin D1, Ki67 and

  11. p16(INK4A) mediates age-related changes in mesenchymal stem cells derived from human dental pulp through the DNA damage and stress response.

    Science.gov (United States)

    Feng, Xingmei; Xing, Jing; Feng, Guijuan; Huang, Dan; Lu, Xiaohui; Liu, Suzhe; Tan, Wei; Li, Liren; Gu, Zhifeng

    2014-01-01

    Mesenchymal stem cells derived from human dental pulp (DP-MSCs) are characterized by self-renewal and multi-lineage differentiation, which play important roles in regenerative medicine. Autologous transfers, as non-immunogenic, constitute the safest approach in cellular transplantations. However, their use may be limited by age-related changes. In the study, we compared DP-MSCs isolated from human in five age groups: 5-12 y, 12-20 y, 20-35 y, 35-50 y, and >50 y. We tested the effect of age on proliferation, differentiation, senescence-associated β-galactosidase (SA-β-gal), cell cycle and programmed cell death. DP-MSCs showed characteristics of senescence as a function of age. Meanwhile, the expression of p16(INK4A) and γ-H2A.X significantly increased with age, whereas heat shock protein 60 (HSP60) was decreased in the senescent DP-MSCs. Reactive oxygen species (ROS) staining showed the number of ROS-stained cells and the DCFH fluorescent level were higher in the aged group. Further we examined the senescence of DP-MSCs after modulating p16(INK4A) signaling. The results indicated the dysfunction of DP-MSCs was reversed by p16(INK4A) siRNA. In summary, our study indicated p16(INK4A) pathway may play a critical role in DP-MSCs age-related changes and the DNA damage response (DDR) and stress response may be the main mediators of DP-MSCs senescence induced by excessive activation of p16(INK4A) signaling. Copyright © 2014. Published by Elsevier Ireland Ltd.

  12. AN UPWARD TREND IN DNA P16INK4A METHYLATION PATTERN AND HIGH RISK HPV INFECTION ACCORDING TO THE SEVERITY OF THE CERVICAL LESION

    Directory of Open Access Journals (Sweden)

    Fernanda Nahoum Carestiato

    2013-09-01

    Full Text Available SUMMARY High-risk human papillomavirus (hr-HPV infection is necessary but not sufficient for cervical cancer development. Recently, P16INK4A gene silencing through hypermethylation has been proposed as an important cofactor in cervical carcinogenesis due to its tumor suppressor function. We aimed to investigate P16INK4A methylation status in normal and neoplastic epithelia and evaluate an association with HPV infection and genotype. This cross-sectional study was performed with 141 cervical samples from patients attending Hospital Moncorvo Filho, Rio de Janeiro. HPV detection and genotyping were performed through PCR and P16INK4A methylation by nested-methylation specific PCR (MSP. HPV frequency was 62.4% (88/141. The most common HPV were HPV16 (37%, HPV18 (16.3% and HPV33/45(15.2%. An upward trend was observed concerning P16INK4A methylation and lesion degree: normal epithelia (10.7%, low grade lesions (22.9%, high grade (57.1% and carcinoma (93.1% (p < 0.0001. A multivariate analysis was performed to evaluate an association between methylation, age, tobacco exposure, HPV infection and genotyping. A correlation was found concerning methylation with HPV infection (p < 0.0001, hr-HPV (p = 0.01, HSIL (p < 0.0007 and malignant lesions (p < 0.0001. Since viral infection and epigenetic alterations are related to cervical carcinoma, we suggest that P16INK4A methylation profile maybe thoroughly investigated as a biomarker to identify patients at risk of cancer.

  13. PD-L1 expression is associated with p16INK4A expression in non-oropharyngeal head and neck squamous cell carcinoma

    Science.gov (United States)

    Chen, San-Chi; Chang, Peter Mu-Hsin; Wang, Hsiao-Jung; Tai, Shyh-Kuan; Chu, Pen-Yuan; Yang, Muh-Hwa

    2018-01-01

    PD-L1 expression is critical in helping tumor cells evade the immune system. However, the level of PD-L1 expression in non-oropharyngeal head and neck squamous cell carcinoma (non-OPHNSCC) and its association with patient prognosis remains unclear. A retrospective clinicopathological analysis was performed on 106 patients with non-OPHNSCC diagnosed between 2007 and 2014. In the current study, tissue arrays from paraffin-embedded non-OPHNSCC samples obtained from patients were constructed, and PD-L1 and p16INK4A expression were determined using immunohistochemistry. Systemic inflammatory factors, including C-reactive protein, serum white blood cell, neutrophil, monocyte and lymphocyte counts were also analyzed. The current study demonstrated that PD-L1 was overexpressed in 32.1% (34/106) and p16INK4A in 20.8% (22/106) of patients. The expression of PD-L1 was associated with p16INK4A expression (P<0.01) but was not associated with levels of systemic inflammatory factors. Tumor stage was determined to be a significant prognostic value (stage I/II vs. III/IV, P=0.03), however, PD-L1, p16INK4A or other clinicopathological factors were not. The current study identified an association between PD-L1 and p16INK4A expression in non-OPHNSCC. This may facilitate the development of anti-PD1/PDL1 therapies to treat patients with head and neck cancer. PMID:29434933

  14. Decreased D2-40 and increased p16INK4A immunoreactivities correlate with higher grade of cervical intraepithelial neoplasia

    Directory of Open Access Journals (Sweden)

    Lu Zhouping

    2011-07-01

    Full Text Available Abstract Background D2-40 has been shown a selective marker for lymphatic endothelium, but also shown in the benign cervical basal cells. However, the application of D2-40 immunoreactivity in the cervical basal cells for identifying the grade of cervical intraepithelial neoplasia (CIN has not been evaluated. Methods In this study, the immunoreactive patterns of D2-40, compared with p16INK4A, which is currently considered as the useful marker for cervical cancers and their precancerous diseases, were examined in total 125 cervical specimens including 32 of CIN1, 37 of CIN2, 35 of CIN3, and 21 of normal cervical tissue. D2-40 and p16INK4A immunoreactivities were scored semiquantitatively according to the intensity and/or extent of the staining. Results Diffuse D2-40 expression with moderate-to-strong intensity was seen in all the normal cervical epithelia (21/21, 100% and similar pattern of D2-40 immunoreactivity with weak-to-strong intensity was observed in CIN1 (31/32, 97.2%. However, negative and/or focal D2-40 expression was found in CIN2 (negative: 20/37, 54.1%; focal: 16/37, 43.2% and CIN3 (negative: 22/35, 62.8%; focal: 12/35, 34.3%. On the other hand, diffuse immunostaining for p16INK4A was shown in 37.5% of CIN1, 64.9% of CIN2, and 80.0% of CIN3. However, the immunoreactive pattern of D2-40 was not associated with the p16INK4A immunoreactivity. Conclusions Immunohistochemical analysis of D2-40 combined with p16INK4A may have a significant implication in clinical practice for better identifying the grade of cervical intraepithelial neoplasia, especially for distinguishing CIN1 from CIN2/3.

  15. Cables1 controls p21/Cip1 protein stability by antagonizing proteasome subunit alpha type 3

    OpenAIRE

    Shi, Zhi; Li, Zenggang; Li, Zijian; Cheng, Kejun; Du, Yuhong; Fu, Haian; Khuri, Fadlo R.

    2014-01-01

    The cyclin-dependent kinase inhibitor 1A (CDKN1A), p21/Cip1, is a vital cell cycle regulator, dysregulation of which has been associated with a large number of human malignancies. One critical mechanism that controls p21 function is through its degradation, which allows the activation of its associated cell cycle promoting kinases, CDK2 and CDK4. Thus, delineating how p21 is stabilized and degraded will enhance our understanding of cell growth control and offer a basis for potential therapeut...

  16. p16(INK4a) /Ki-67 dual labelling as a marker for the presence of high-grade cancer cells or disease progression in urinary cytopathology.

    Science.gov (United States)

    Piaton, E; Advenier, A S; Carré, C; Decaussin-Petrucci, M; Mege-Lechevallier, F; Ruffion, A

    2013-10-01

    Overexpression of p16(INK4a) independent of the presence of E6-E7 oncoproteins of high-risk papillomaviruses has been identified in bladder carcinoma in situ lesions with or without concurrent papillary or invasive high-grade (HG) urothelial carcinoma. As p16(INK4a) and Ki-67 co-expression clearly indicates deregulation of the cell cycle, the aim of this study was to investigate the frequency of p16(INK4a) /Ki-67 dual labelling in urinary cytology samples. Immunolabelling was performed in demounted, destained Papanicolaou slides after ThinPrep(®) processing. A total of 84 urinary cytology samples (18 negative, 10 low grade, 19 atypical urothelial cells and 37 high grade) were analysed for p16(INK4a) /Ki-67 co-expression. We assessed underlying urothelial malignancy with cystoscopy, histopathology and follow-up data in every case. Compared with raw histopathological results, p16 (INK4a) /Ki-67 dual labelling was observed in 48 out of 55 (87.3%) HG lesions and in 11 out of 29 (37.9%) negative, papillary urothelial neoplasia of low malignant potential or low-grade carcinomas (P = 0.05). All cases with high-grade/malignant cytology were dual labelled. Sixteen out of 17 (94.1%) carcinoma in situ cases and eight out of 14 (57.1%) cases with atypical urothelial cells matching with HG lesions were dual labelled. Extended follow-up allowed three cases of progression to be diagnosed in dual-labelled cases with negative/low-grade cytology results after a 9- to 11-months delay. The data show that p16(INK4a) /Ki-67 co-expression allows most HG cancer cells to be detected initially and in the follow-up period. Additional studies are needed in order to determine whether dual labelling can be used as a triage tool for atypical urothelial cells in the urine. © 2012 John Wiley & Sons Ltd.

  17. Concurrent disruption of p16INK4a and the ARF-p53 pathway predicts poor prognosis in aggressive non-Hodgkin's lymphoma

    DEFF Research Database (Denmark)

    Grønbaek, K; de Nully Brown, P; Møller, Michael Boe

    2000-01-01

    . By using a panel of PCR-based methods, we have examined the status of the p16INK4a, ARF and p53 genes in 123 cases of non-Hodgkin's lymphoma (NHL) at diagnosis. Alterations of one or more of these genes were detected in seven of 36 (19%) cases with low- to intermediate-grade histology, and in 35 of 87 (40...

  18. p38 MAPK and JNK antagonistically control senescence and cytoplasmic p16INK4A expression in doxorubicin-treated endothelial progenitor cells.

    Directory of Open Access Journals (Sweden)

    Paolo Spallarossa

    Full Text Available Patients treated with low-dose anthracyclines often show late onset cardiotoxicity. Recent studies suggest that this form of cardiotoxicity is the result of a progenitor cell disease. In this study we demonstrate that Cord Blood Endothelial Progenitor Cells (EPCs exposed to low, sub-apoptotic doses of doxorubicin show a senescence phenotype characterized by increased SA-b-gal activity, decreased TRF2 and chromosomal abnormalities, enlarged cell shape, and disarrangement of F-actin stress fibers accompanied by impaired migratory ability. P16( INK4A localizes in the cytoplasm of doxorubicin-induced senescent EPCs and not in the nucleus as is the case in EPCs rendered senescent by different stimuli. This localization together with the presence of an arrest in G2, and not at the G1 phase boundary, which is what usually occurs in response to the cell cycle regulatory activity of p16(INK4A, suggests that doxorubicin-induced p16( INK4A does not regulate the cell cycle, even though its increase is closely associated with senescence. The effects of doxorubicin are the result of the activation of MAPKs p38 and JNK which act antagonistically. JNK attenuates the senescence, p16( INK4A expression and cytoskeleton remodeling that are induced by activated p38. We also found that conditioned medium from doxorubicin-induced senescent cardiomyocytes does not attract untreated EPCs, unlike conditioned medium from apoptotic cardiomyocytes which has a strong chemoattractant capacity. In conclusion, this study provides a better understanding of the senescence of doxorubicin-treated EPCs, which may be helpful in preventing and treating late onset cardiotoxicity.

  19. Double positivity for HPV-DNA/p16ink4a is the biomarker with strongest diagnostic accuracy and prognostic value for human papillomavirus related oropharyngeal cancer patients.

    Science.gov (United States)

    Mena, Marisa; Taberna, Miren; Tous, Sara; Marquez, Sandra; Clavero, Omar; Quiros, Beatriz; Lloveras, Belen; Alejo, Maria; Leon, Xavier; Quer, Miquel; Bagué, Silvia; Mesia, Ricard; Nogués, Julio; Gomà, Montserrat; Aguila, Anton; Bonfill, Teresa; Blazquez, Carmen; Guix, Marta; Hijano, Rafael; Torres, Montserrat; Holzinger, Dana; Pawlita, Michael; Pavon, Miguel Angel; Bravo, Ignacio G; de Sanjosé, Silvia; Bosch, Francesc Xavier; Alemany, Laia

    2018-03-01

    The etiologic role of human papillomaviruses (HPV) in oropharyngeal cancer (OPC) is well established. Nevertheless, information on survival differences by anatomic sub-site or treatment remains scarce, and it is still unclear the HPV-relatedness definition with best diagnostic accuracy and prognostic value. We conducted a retrospective cohort study of all patients diagnosed with a primary OPC in four Catalonian hospitals from 1990 to 2013. Formalin-fixed, paraffin-embedded cancer tissues were subjected to histopathological evaluation, DNA quality control, HPV-DNA detection, and p16 INK4a /pRb/p53/Cyclin-D1 immunohistochemistry. HPV-DNA positive and a random sample of HPV-DNA negative cases were subjected to HPV-E6*I mRNA detection. Demographic, tobacco/alcohol use, clinical and follow-up data were collected. Multivariate models were used to evaluate factors associated with HPV positivity as defined by four different HPV-relatedness definitions. Proportional-hazards models were used to compare the risk of death and recurrence among HPV-related and non-related OPC. 788 patients yielded a valid HPV-DNA result. The percentage of positive cases was 10.9%, 10.2%, 8.5% and 7.4% for p16 INK4a , HPV-DNA, HPV-DNA/HPV-E6*I mRNA, and HPV-DNA/p16 INK4a , respectively. Being non-smoker or non-drinker was consistently associated across HPV-relatedness definitions with HPV positivity. A suggestion of survival differences between anatomic sub-sites and treatments was observed. Double positivity for HPV-DNA/p16 INK4a showed strongest diagnostic accuracy and prognostic value. Double positivity for HPV-DNA/p16 INK4a , a test that can be easily implemented in the clinical practice, has optimal diagnostic accuracy and prognostic value. Our results have strong clinical implications for patients' classification and handling and also suggest that not all the HPV-related OPC behave similarly. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. IL-6 modulates hepatocyte proliferation via induction of HGF/p21cip1: Regulation by SOCS3

    International Nuclear Information System (INIS)

    Sun Rui; Jaruga, Barbara; Kulkarni, Shailin; Sun Haoyu; Gao Bin

    2005-01-01

    The precise role of IL-6 in liver regeneration and hepatocyte proliferation is controversial and the role of SOCS3 in liver regeneration remains unknown. Here we show that in vitro treatment with IL-6 inhibited primary mouse hepatocyte proliferation. IL-6 induced p21 cip1 protein expression in primary mouse hepatocytes. Disruption of the p21 cip1 gene abolished the inhibitory effect of IL-6 on cell proliferation. Co-culture with nonparenchymal liver cells diminished IL-6 inhibition of hepatocyte proliferation, which was likely due to IL-6 stimulation of nonparenchymal cells to produce HGF. Finally, IL-6 induced higher levels of p21 cip1 protein expression and a slightly stronger inhibition of cell proliferation in SOCS3 +/- mouse hepatocytes compared to wild-type hepatocytes, while liver regeneration was enhanced and prolonged in SOCS3 +/- mice. Our findings suggest that IL-6 directly inhibits hepatocyte proliferation via a p21 cip1 -dependent mechanism and indirectly enhances hepatocyte proliferation via stimulating nonparenchymal cells to produce HGF. SOCS3 negatively regulates liver regeneration

  1. High-grade acute organ toxicity and p16INK4A expression as positive prognostic factors in primary radio(chemo)therapy for patients with head and neck squamous cell carcinoma

    International Nuclear Information System (INIS)

    Tehrany, Narges; Rave-Fraenk, Margret; Hess, Clemens F.; Wolff, Hendrik A.; Kitz, Julia; Li, Li; Kueffer, Stefan; Lorenzen, Stephan; Beissbarth, Tim; Burfeind, Peter; Reichardt, Holger M.; Canis, Martin

    2015-01-01

    Superior treatment response and survival for patients with human papilloma virus (HPV)-positive head and neck cancer (HNSCC) are documented in clinical studies. However, the relevance of high-grade acute organ toxicity (HGAOT), which has also been correlated with improved prognosis, has attracted scant attention in HPV-positive HNSCC patients. Hence we tested the hypothesis that both parameters, HPV and HGAOT, are positive prognostic factors in patients with HNSCC treated with definite radiotherapy (RT) or radiochemotherapy (RCT). Pretreatment tumor tissue and clinical records were available from 233 patients receiving definite RT (62 patients) or RCT (171 patients). HPV infection was analysed by means of HPV DNA detection or p16 INK4A expression; HGAOT was defined as the occurrence of acute organ toxicity >grade 2 according to the Common Toxicity Criteria. Both variables were correlated with overall survival (OS) using Cox proportional hazards regression. Positivity for HPV DNA (44 samples, 18.9 %) and p16 INK4A expression (102 samples, 43.8 %) were significantly correlated (p < 0.01), and HGAOT occurred in 77 (33 %) patients. Overall, the 5-year OS was 23 %; stratified for p16 INK4A expression and HGAOT, OS rates were 47 %, 42 %, 20 % and 10 % for patients with p16 INK4A expression and HGAOT, patients with HGAOT only, patients with p16 INK4A expression only, and patients without p16 INK4A expression or HGAOT, respectively. After multivariate testing p16 INK4A expression (p = 0.003) and HGAOT (p < 0.001) were significantly associated with OS. P16 INK4A expression and HGAOT are independent prognostic factors for OS of patients with HNSCC, whereas p16 INK4A expression is particularly important for patients without HGAOT. (orig.) [de

  2. Loss of heterozygosity of CDKN2A (p16INK4a) and RB1 tumor suppressor genes in testicular germ cell tumors

    International Nuclear Information System (INIS)

    Vladusic, Tomislav; Hrascan, Reno; Pecina-Slaus, Nives; Vrhovac, Ivana; Gamulin, Marija; Franekic, Jasna; Kruslin, Bozo

    2010-01-01

    Testicular germ cell tumors (TGCTs) are the most frequent malignances in young adult men. The two main histological forms, seminomas and nonseminomas, differ biologically and clinically. pRB protein and its immediate upstream regulator p16INK4a are involved in the RB pathway which is deregulated in most TGCTs. The objective of this study was to evaluate the occurrence of loss of heterozygosity (LOH) of the CDKN2A (p16INK4a) and RB1 tumor suppressor genes in TGCTs. Forty TGCTs (18 seminomas and 22 nonseminomas) were analyzed by polymerase chain reaction using the restriction fragment length polymorphism or the nucleotide repeat polymorphism method. LOH of the CDKN2A was found in two (6%) out of 34 (85%) informative cases of our total TGCT sample. The observed changes were assigned to two (11%) nonseminomas out of 18 (82%) informative samples. Furthermore, LOH of the RB1 was detected in two (6%) out of 34 (85%) informative cases of our total TGCT sample. Once again, the observed changes were assigned to two (10.5%) nonseminomas out of 19 (86%) informative samples. Both LOHs of the CDKN2A were found in nonseminomas with a yolk sac tumor component, and both LOHs of the RB1 were found in nonseminomas with an embryonal carcinoma component. The higher incidence of observed LOH in nonseminomas may provide a clue to their invasive behavior

  3. Culturing on Wharton's jelly extract delays mesenchymal stem cell senescence through p53 and p16INK4a/pRb pathways.

    Science.gov (United States)

    Hao, Haojie; Chen, Guanghui; Liu, Jiejie; Ti, Dongdong; Zhao, Yali; Xu, Shenjun; Fu, Xiaobing; Han, Weidong

    2013-01-01

    Mesenchymal stem cells (MSCs) hold great therapeutic potential. However, MSCs undergo replication senescence during the in vitro expansion process. Wharton's jelly from the human umbilical cord harbors a large number of MSCs. In this study, we hypothesized that Wharton's jelly would be beneficial for in vitro expansion of MSCs. Wharton's jelly extract (WJEs), which is mainly composed of extracellular matrix and cytokines, was prepared as coating substrate. Human MSCs were isolated and cultured on WJE-coated plates. Although the proliferation capacity of cells was not augmented by WJE in early phase culture, adynamic growth in late-phase culture was clearly reduced, suggesting that the replicative senescence of MSCs was efficiently slowed by WJE. This was confirmed by β-galactosidase staining and telomere length measurements of MSCs in late-phase culture. In addition, the decreased differentiation ability of MSCs after long-term culture was largely ameliorated by WJE. Reactive oxygen species (ROS), p53, and p16INK4a/pRb expression increased with passaging. Analysis at the molecular level revealed that WJE-based culture efficiently suppressed the enhancement of intracellular ROS, p53, and p16INK4a/pRb in MSCs. These data demonstrated that WJE provided an ideal microenvironment for MSCs culture expansion in vitro preserved MSC properties by delaying MSCs senescence, and allowed large numbers of MSCs to be obtained for basic research and clinical therapies.

  4. Cables1 controls p21/Cip1 protein stability by antagonizing proteasome subunit alpha type 3.

    Science.gov (United States)

    Shi, Z; Li, Z; Li, Z J; Cheng, K; Du, Y; Fu, H; Khuri, F R

    2015-05-07

    The cyclin-dependent kinase (CDK) inhibitor 1A, p21/Cip1, is a vital cell cycle regulator, dysregulation of which has been associated with a large number of human malignancies. One critical mechanism that controls p21 function is through its degradation, which allows the activation of its associated cell cycle-promoting kinases, CDK2 and CDK4. Thus delineating how p21 is stabilized and degraded will enhance our understanding of cell growth control and offer a basis for potential therapeutic interventions. Here we report a novel regulatory mechanism that controls the dynamic status of p21 through its interaction with Cdk5 and Abl enzyme substrate 1 (Cables1). Cables1 has a proposed role as a tumor suppressor. We found that upregulation of Cables1 protein was correlated with increased half-life of p21 protein, which was attributed to Cables1/p21 complex formation and supported by their co-localization in the nucleus. Mechanistically, Cables1 interferes with the proteasome (Prosome, Macropain) subunit alpha type 3 (PSMA3) binding to p21 and protects p21 from PSMA3-mediated proteasomal degradation. Moreover, silencing of p21 partially reverses the ability of Cables1 to induce cell death and inhibit cell proliferation. In further support of a potential pathophysiological role of Cables1, the expression level of Cables1 is tightly associated with p21 in both cancer cell lines and human lung cancer patient tumor samples. Together, these results suggest Cables1 as a novel p21 regulator through maintaining p21 stability and support the model that the tumor-suppressive function of Cables1 occurs at least in part through enhancing the tumor-suppressive activity of p21.

  5. Avaliação da expressão imunoistoquímica da proteína p16INK4a no adenocarcinoma de esôfago Protein p16INK4a immunohistochemical expression in adenocarcinoma of the esophagus

    Directory of Open Access Journals (Sweden)

    Mário Henrique Osanai

    2011-12-01

    Full Text Available INTRODUÇÃO: O adenocarcinoma de esôfago apresenta aumento de frequência nas últimas décadas, particularmente em países desenvolvidos. O esôfago de Barrett é reconhecido como a principal lesão precursora e o estudo da sequência metaplasia-displasia-adenocarcinoma mostra a ocorrência de alterações genéticas desde suas fases mais incipientes. As alterações no p16INK4a são relatadas como frequentes no esôfago de Barrett e no carcinoma de esôfago. OBJETIVO: Verificar a prevalência da expressão imunoistoquímica da proteína p16INK4a em exames anatomopatológicos de pacientes com adenocarcinoma de esôfago. MÉTODO: A população do estudo foi constituída de 37 pacientes com adenocarcinoma de esôfago. A expressão da proteína p16 foi detectada por meio de análise imunoistoquímica, com anticorpo primário p16INK4aAb-7, clone 16P07, NeoMarkers e avaliada de acordo com o Sistema de Escore de Imunorreatividade (Immunoreactive scoring system - IRS modificado. RESULTADOS: No grupo houve predominância de pacientes do sexo masculino (86,5% e a maioria dos casos correspondia a estádios avançados (III e IV = 67,5%. Em 12 casos (32,4% foi identificada expressão imunoistoquímica da proteína p16INK4a. Não foi observada relação significativa entre a perda da expressão da proteína p16INK4a e o grau de diferenciação histológica (p=0,81 nem com o estadiamento da doença (p=0,485. CONCLUSÃO: Ocorre perda da expressão imunoistoquímica da proteína p16INK4a, corroborando as informações de que a inativação do gene p16 é um evento frequente e que pode exercer papel importante na carcinogênese do adenocarcinoma de esôfago.BACKGROUND: The esophageal adenocarcinoma shows an increasing frequence in the last decades, specially in the developed countries. The Barrett´s esophagus is accepted as the major premalignant lesion and the metaplasia-dysplasia-adenocarcinoma sequence presents a lot of genetic changes since its early

  6. TGFbeta induces apoptosis and EMT in primary mouse hepatocytes independently of p53, p21Cip1 or Rb status

    International Nuclear Information System (INIS)

    Sheahan, Sharon; Bellamy, Christopher O; Harland, Stephen N; Harrison, David J; Prost, Sandrine

    2008-01-01

    TGFβ has pleiotropic effects that range from regulation of proliferation and apoptosis to morphological changes and epithelial-mesenchymal transition (EMT). Some evidence suggests that these effects may be interconnected. We have recently reported that P53, P21 Cip1 and pRB, three critical regulators of the G1/S transition are variably involved in TGFβ-induced cell cycle arrest in hepatocytes. As these proteins are also involved in the regulation of apoptosis in many circumstances, we investigated their contribution to other relevant TGFβ-induced effects, namely apoptosis and EMT, and examined how the various processes were interrelated. Primary mouse hepatocytes deficient in p53, p21 and/or Rb, singly or in combination were treated with TGFβ for 24 to 96 hours. Apoptosis was quantified according to morphology and by immunostaining for cleaved-capsase 3. Epithelial and mesenchymal marker expression was studied using immunocytochemistry and real time PCR. We found that TGFβ similarly induced morphological changes regardless of genotype and independently of proliferation index or sensitivity to inhibition of proliferation by TGFβ. Morphological changes were accompanied by decrease in E-cadherin and increased Snail expression but the mesenchymal markers (N-cadherin, SMAα and Vimentin) studied remained unchanged. TGFβ induced high levels of apoptosis in p53-/-, Rb-/-, p21 cip1 -/- and control hepatocytes although with slight differences in kinetics. This was unrelated to proliferation or changes in morphology and loss of cell-cell adhesion. However, hepatocytes deficient in both p53 and p21 cip1 were less sensitive to TGFβ-induced apoptosis. Although p53, p21 Cip1 and pRb are well known regulators of both proliferation and apoptosis in response to a multitude of stresses, we conclude that they are critical for TGFβ-driven inhibition of hepatocytes proliferation, but only slightly modulate TGFβ-induced apoptosis. This effect may depend on other parameters

  7. Sexual behaviour, HPV status and p16INK4a expression in oropharyngeal and oral cavity squamous cell carcinomas: a case-case comparison study.

    Science.gov (United States)

    Emmett, Sarah; Boros, Samuel; Whiteman, David C; Porceddu, Sandro V; Panizza, Benedict J; Antonsson, Annika

    2018-06-01

    A significant proportion of mucosal squamous cell carcinomas of the head and neck (HNSCC; particularly of the oropharynx) are directly attributable to the human papillomavirus (HPV). The increase in the incidence of HPV-related tumours has been postulated to be due to changing sexual practices in the community. We analysed 136 formalin-fixed paraffin-embedded squamous cell carcinomas from the oral cavity (n=40) and oropharynx (n=96) recruited from the Princess Alexandra Hospital (Brisbane, Australia). Samples were analysed for the presence of HPV DNA using a combination of mucosal HPV general primer GP+ PCR and sequencing; p 16INK4a expression was assessed by immunohistochemistry. Each patient completed a questionnaire detailing their lifestyle factors, such as tobacco smoking and alcohol consumption, marital status, and sexual behaviour and history. The HPV DNA prevalence was 5 % in the oral cavity cancers and 72 % in the oropharyngeal cancers (P<0.0001). HPV-16 was the most commonly detected HPV type (found in 91 % of all HPV-positive tumours). There was a strong correlation between HPV DNA positivity and positive p16 INK4a staining in oropharyngeal tumours (P<0.0001). Having an HPV-related tumour was associated with being married or having been married previously (P=0.046), an increasing number of passionate kissing partners (P=0.046), ever having given oral sex (P=0.0007) and an increasing number of oral sex partners (P=0.0015). This study found a higher prevalence of HPV in oropharyngeal compared to oral cavity tumours, with a strong association being identified between oral sex behaviours and HPV-positive tumours. Further research is needed to establish that vaccines will reduce the transmission and carriage of oropharyngeal HPV infections.

  8. p16(INK4A) inhibits the pro-metastatic potentials of osteosarcoma cells through targeting the ERK pathway and TGF-β1.

    Science.gov (United States)

    Silva, Gabriela; Aboussekhra, Abdelilah

    2016-05-01

    Extracellular signal-regulated kinase (ERK) is a downstream component of the evolutionarily conserved mitogen-activated protein kinase-signaling pathway, which controls the expression of a plethora of genes implicated in various physiological processes. This pathway is often hyper-activated by mutations or abnormal extracellular signaling in different types of human cancer, including the most common primary malignant bone tumor osteosarcomas. p16(INK4A) is an important tumor suppressor gene frequently lost in osteosarcomas, and is associated with the progression of these malignancies. We have shown, here, that the ERK1/2 protein kinase is also activated by p16(INK4A) down-regulation in osteosarcoma cells and normal human as well as mouse cells. This inhibitory effect is associated with the suppression of the upstream kinase MEK1/2, and is mediated via the repression of miR-21-5p and the consequent up-regulation of the MEK/ERK antagonist SPRY2 in osteosarcoma cells. Furthermore, we have shown that p16(INK4) inhibits the migration/invasion abilities of these cells through miR-21-5p-dependent inhibition of ERK1/2. In addition, we present clear evidence that p16(INK4) represses the paracrine pro-migratory effect of osteosarcoma cells on stromal fibroblasts through the inhibition of the TGF-β1 expression/secretion. This effect is also ERK1/2-dependent, indicating that in addition to their cell-autonomous actions, p16(INK4) and ERK1/2 have also non-cell-autonomous cancer-related functions. Together, these results indicate that the tumor suppressor p16(INK4) protein represses the carcinogenic process of osteosarcoma cells not only as a cell cycle regulator, but also as a negative regulator of pro-carcinogenic/-metastatic pathways. This indicates that targeting the ERK pathway is of utmost therapeutic value. © 2015 Wiley Periodicals, Inc.

  9. Immunostaining for p16(INK4a) used as a conjunctive tool improves interobserver agreement of the histologic diagnosis of cervical intraepithelial neoplasia

    DEFF Research Database (Denmark)

    Horn, L.C.; Reichert, A.; Oster, A.

    2008-01-01

    The quality of cervical histopathology is critical to cervical cancer prevention, cancer treatment, and research programs. On the basis of the histology results further patient management is determined. However, the diagnostic interpretation of histologic hematoxylin-eosin (H&E)-stained slides is...... immunohistochemistry as an adjunct to conventional H&E-stained specimens thus contributes to a more reproducible diagnosis of cervical intraepithelial neoplasia, and may be a valuable aid for the interpretation of cervical histology Udgivelsesdato: 2008/4......The quality of cervical histopathology is critical to cervical cancer prevention, cancer treatment, and research programs. On the basis of the histology results further patient management is determined. However, the diagnostic interpretation of histologic hematoxylin-eosin (H&E)-stained slides......) immunohistochemistry may increase the performance of pathologists in diagnosing squamous lesions in cervical punch and cone biopsies. When using a consecutive p 16(INK4a)-stained slide in conjunction to the H&E-stained slide, interobserver agreement between 6 pathologists improved significantly for both cervical punch...

  10. p16(INK4a suppression by glucose restriction contributes to human cellular lifespan extension through SIRT1-mediated epigenetic and genetic mechanisms.

    Directory of Open Access Journals (Sweden)

    Yuanyuan Li

    2011-02-01

    Full Text Available Although caloric restriction (CR has been shown to increase lifespan in various animal models, the mechanisms underlying this phenomenon have not yet been revealed. We developed an in vitro system to mimic CR by reducing glucose concentration in cell growth medium which excludes metabolic factors and allows assessment of the effects of CR at the cellular and molecular level. We monitored cellular proliferation of normal WI-38, IMR-90 and MRC-5 human lung fibroblasts and found that glucose restriction (GR can inhibit cellular senescence and significantly extend cellular lifespan compared with cells receiving normal glucose (NG in the culture medium. Moreover, GR decreased expression of p16(INK4a (p16, a well-known senescence-related gene, in all of the tested cell lines. Over-expressed p16 resulted in early replicative senescence in glucose-restricted cells suggesting a crucial role of p16 regulation in GR-induced cellular lifespan extension. The decreased expression of p16 was partly due to GR-induced chromatin remodeling through effects on histone acetylation and methylation of the p16 promoter. GR resulted in an increased expression of SIRT1, a NAD-dependent histone deacetylase, which has positive correlation with CR-induced longevity. The elevated SIRT1 was accompanied by enhanced activation of the Akt/p70S6K1 signaling pathway in response to GR. Furthermore, knockdown of SIRT1 abolished GR-induced p16 repression as well as Akt/p70S6K1 activation implying that SIRT1 may affect p16 repression through direct deacetylation effects and indirect regulation of Akt/p70S6K1 signaling. Collectively, these results provide new insights into interactions between epigenetic and genetic mechanisms on CR-induced longevity that may contribute to anti-aging approaches and also provide a general molecular model for studying CR in vitro in mammalian systems.

  11. Usefulness of p16ink4a, ProEX C, and Ki-67 for the diagnosis of glandular dysplasia and adenocarcinoma of the cervix uteri.

    Science.gov (United States)

    Negri, Giovanni; Bellisano, Giulia; Carico, Elisabetta; Faa, Gavino; Kasal, Armin; Antoniazzi, Sonia; Egarter-Vigl, Eduard; Piccin, Andrea; Dalla Palma, Paolo; Vittadello, Fabio

    2011-07-01

    Although the diagnostic criteria of in-situ and invasive adenocarcinomas of the cervix uteri are well established, the differentiation from benign mimics may be difficult and the morphologic features of the precursors of endocervical adenocarcinoma are still debated. In this study, we evaluated the usefulness of p16ink4a (p16), ProEX C, and Ki-67 for the diagnosis of endocervical adenocarcinoma and its precursors. Immunohistochemistry with p16, ProEX C, and Ki-67 was performed in 82 glandular lesions including 15 invasive adenocarcinomas, 29 adenocarcinomas in situ (AIS), 22 non-neoplastic samples, and 16 cases of glandular dysplasia (GD), which showed significant nuclear abnormalities but did not meet the diagnostic criteria for AIS. The immunohistochemical expression pattern was scored according to the percentage of the stained cells (0, 1+, 2+, and 3+ when 0% to 5%, 6% to 25%, 26% to 50%, and more than 50% of the cells were stained, respectively) and was evaluated for each antibody. p16 was at least focally expressed (1+ or more) in 14 of 15 invasive adenocarcinomas, in all AIS and in 7 negative samples. ProEX C and Ki-67 both scored 1+ or more in all adenocarcinomas and AIS and in 8 and 6 negative samples, respectively. Of the GD 15, 14, and 15 expressed p16, ProEX C, and Ki-67, respectively. The score differences between neoplastic and non-neoplastic samples were highly significant for each marker (Pcervix uteri and may also improve the diagnostic accuracy of endocervical GD. In particularly problematic cases, the combination of p16 and a proliferation marker can provide additional help for the interpretation of these lesions.

  12. The PPARα/p16INK4a Pathway inhibits Vascular Smooth Muscle Cell Proliferation by repressing Cell Cycle-dependent Telomerase Activation

    Science.gov (United States)

    Gizard, Florence; Nomiyama, Takashi; Zhao, Yue; Findeisen, Hannes M.; Heywood, Elizabeth B.; Jones, Karrie L.; Staels, Bart; Bruemmer, Dennis

    2009-01-01

    Peroxisome Proliferator-Activated Receptor (PPAR) α, the molecular target for fibrates used to treat dyslipidemia, exerts pleiotropic effects on vascular cells. In vascular smooth muscle cells (VSMCs), we have previously demonstrated that PPARα activation suppresses G1→S cell cycle progression by targeting the cyclin-dependent kinase inhibitor p16INK4a (p16). In the present study, we demonstrate that this inhibition of VSMC proliferation by PPARα is mediated through a p16-dependent suppression of telomerase activity, which has been implicated in key cellular functions including proliferation. PPARα activation inhibited mitogen-induced telomerase activity by repressing the catalytic subunit telomerase reverse transcriptase (TERT) through negative cross-talk with an E2F-1-dependent trans-activation of the TERT promoter. This trans-repression involved the recruitment of the retinoblastoma (RB) family proteins p107 and p130 to the TERT promoter resulting in impaired E2F-1 binding, an effect which was dependent on p16. The inhibition of cell proliferation by PPARα activation was lost in VSMC following TERT overexpression or knock-down, pointing to a key role of telomerase as a target for the antiproliferative effects of PPARα. Finally, we demonstrate that PPARα agonists suppress telomerase activation during the proliferative response following vascular injury indicating that these findings are applicable in vivo. In concert, these results demonstrate that the anti-proliferative effects of PPARα in VSMCs depend on the suppression of telomerase activity by targeting the p16/RB/E2F transcriptional cascade. PMID:18818403

  13. Are adjunctive markers useful in routine cervical cancer screening? Application of p16(INK4a) and HPV-PCR on ThinPrep samples with histological follow-up

    DEFF Research Database (Denmark)

    Schledermann, D; Andersen, B T; Bisgaard, K

    2008-01-01

    The objectives of the study were to evaluate 1) the diagnostic sensitivity and specificity of p16(INK4a) as a marker for high-grade cervical lesions, 2) the results of a real-time polymerase chain reaction detecting high-risk human papillomavirus, and 3) the interobserver variability of the p16(INK...

  14. SM22α-induced activation of p16INK4a/retinoblastoma pathway promotes cellular senescence caused by a subclinical dose of γ-radiation and doxorubicin in HepG2 cells

    International Nuclear Information System (INIS)

    Kim, Tae Rim; Lee, Hee Min; Lee, So Yong; Kim, Eun Jin; Kim, Kug Chan; Paik, Sang Gi; Cho, Eun Wie; Kim, In Gyu

    2010-01-01

    Research highlights: → SM22α overexpression in HepG2 cells leads cells to a growth arrest state, and the treatment of a subclinical dose of γ-radiation or doxorubicin promotes cellular senescence. → SM22α overexpression elevates p16 INK4a followed by pRB activation, but there are no effects on p53/p21 WAF1/Cip1 pathway. → SM22α-induced MT-1G activates p16 INK4a /pRB pathway, which promotes cellular senescence by damaging agents. -- Abstract: Smooth muscle protein 22-alpha (SM22α) is known as a transformation- and shape change-sensitive actin cross-linking protein found in smooth muscle tissue and fibroblasts; however, its functional role remains uncertain. We reported previously that SM22α overexpression confers resistance against anti-cancer drugs or radiation via induction of metallothionein (MT) isozymes in HepG2 cells. In this study, we demonstrate that SM22α overexpression leads cells to a growth arrest state and promotes cellular senescence caused by treatment with a subclinical dose of γ-radiation (0.05 and 0.1 Gy) or doxorubicin (0.01 and 0.05 μg/ml), compared to control cells. Senescence growth arrest is known to be controlled by p53 phosphorylation/p21 WAF1/Cip1 induction or p16 INK4a /retinoblastoma protein (pRB) activation. SM22α overexpression in HepG2 cells elevated p16 INK4a followed by pRB activation, but did not activate the p53/p21 WAF1/Cip1 pathway. Moreover, MT-1G, which is induced by SM22α overexpression, was involved in the activation of the p16 INK4a /pRB pathway, which led to a growth arrest state and promoted cellular senescence caused by damaging agents. Our findings provide the first demonstration that SM22α modulates cellular senescence caused by damaging agents via regulation of the p16 INK4a /pRB pathway in HepG2 cells and that these effects of SM22α are partially mediated by MT-1G.

  15. A pilot study to compare the detection of HPV-16 biomarkers in salivary oral rinses with tumour p16INK4a expression in head and neck squamous cell carcinoma patients

    International Nuclear Information System (INIS)

    Chai, Ryan C.; Lim, Yenkai; Frazer, Ian H.; Wan, Yunxia; Perry, Christopher; Jones, Lee; Lambie, Duncan; Punyadeera, Chamindie

    2016-01-01

    Human papilloma virus-16 (HPV-16) infection is a major risk factor for a subset of head and neck squamous cell carcinoma (HNSCC), in particular oropharyngeal squamous cell carcinoma (OPSCC). Current techniques for assessing the HPV-16 status in HNSCC include the detection of HPV-16 DNA and p16 INK4a expression in tumor tissues. When tumors originate from hidden anatomical sites, this method can be challenging. A non-invasive and cost-effective alternative to biopsy is therefore desirable for HPV-16 detection especially within a community setting to screen at-risk individuals. The present study compared detection of HPV-16 DNA and RNA in salivary oral rinses with tumor p16 INK4a status, in 82 HNSCC patients using end-point and quantitative polymerase chain reaction (PCR). Of 42 patients with p16 INK4a -positive tumours, 39 (sensitivity = 92.9 %, PPV = 100 % and NPV = 93 %) had oral rinse samples with detectable HPV-16 DNA, using end-point and quantitative PCR. No HPV-16 DNA was detected in oral rinse samples from 40 patients with p16 INK4a negative tumours, yielding a test specificity of 100 %. For patients with p16 INK4a positive tumours, HPV-16 mRNA was detected using end-point reverse transcription PCR (RT-PCR) in 24/40 (sensitivity = 60 %, PPV = 100 % and NPV = 71 %), and using quantitative RT-PCR in 22/40 (sensitivity = 55 %, PPV = 100 % and NPV = 69 %). No HPV-16 mRNA was detected in oral rinse samples from the p16 INK4a -negative patients, yielding a specificity of 100 %. We demonstrate that the detection of HPV-16 DNA in salivary oral rinse is indicative of HPV status in HNSCC patients and can potentially be used as a diagnostic tool in addition to the current methods. The online version of this article (doi:10.1186/s12885-016-2217-1) contains supplementary material, which is available to authorized users

  16. Detection of HPV and the role of p16INK4A overexpression as a surrogate marker for the presence of functional HPV oncoprotein E7 in colorectal cancer

    Directory of Open Access Journals (Sweden)

    Lardon Filip

    2010-03-01

    Full Text Available Abstract Background Based on the well-recognized etiological role of human papillomavirus (HPV in cervical, anogenital and oropharyngeal carcinogenesis, a potential role of HPV in colorectal carcinogenesis has been suggested. For that reason, the aim of the present study was to investigate the presence of HPV DNA in colorectal carcinomas (CRC and to study overexpression of p16INK4A as a marker for the presence of an active HPV oncoprotein E7. These findings were correlated with clinical and pathological prognostic factors of CRC. Methods The presence of HPV was assessed using a multiplex PCR system of 10 non-biotinylated primers. The amplified fragments of HPV positive samples were further analyzed by a highly sensitive, broad spectrum SPF10 PCR and subsequently genotyped using reverse hybridization in a line probe assay. P16INK4A protein expression was investigated in a subset of 90 (30 HPV positive and 60 HPV negative CRC samples by immunohistochemistry. Results HPV DNA was found in 14.2% of the CRC samples with HPV16 as the most prevalent type. No significant differences in clinical and pathological variables were found between HPV positive and negative CRCs, except for age. HPV positive patients were significantly younger (p = 0.05. There was no significant correlation between the presence of HPV and overexpression of p16INK4A (p = 0.325. Conclusions In conclusion, the presence of oncogenic HPV DNA in a small cohort of CRC samples may suggest that HPV may be involved in the carcinogenesis of some CRC. However, contrary to what has been observed in head and neck squamous cell cancer and cancer of the uterine cervix, p16INK4A does not seem to be a surrogate marker for an active HPV infection in CRC. Therefore, further functional analyses are necessary to elucidate the role of HPV in CRC.

  17. Inmunohistoquímica de la proteína p16INK4a en biopsias y extendidos cervicovaginales y su relación con HPV por PCR Immunohistochemistry of p16INK4a in biopsies and cervicovaginal smears, and its correlation with HPV detected by PCR

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    Alejandro García

    2008-12-01

    Full Text Available Estudios recientes sugieren que la sobreexpresión de p16, determinada por inmunohistoquímica, sería un marcador específico de células escamosas displásicas y neoplásicas con alta asociación con HPV de alto riesgo. Nuestro objetivo fue correlacionar los hallazgos cito/histológicos con la expresión de p16 y el subtipo de HPV por PCR. Seleccionamos 95 biopsias de cuello uterino y 4 legrados endocervicales de 99 individuos, y 30 extendidos cervicovaginales de otros 30 individuos, que se dividieron según el diagnóstico morfológico. Inmunomarcamos cortes del material incluido en parafina y los extendidos con el kit CINtecT p16INK4a (DAKO. Evaluamos HPV por PCR utilizando 25/99 biopsias con lesión intraepitelial escamosa de bajo grado. Observamos marcación positiva para p16 en 1/35 biopsias (2.9% y 1/11 extendidos (9% en los grupos sin HPV ni displasia; 16/25 biopsias (64% y 6/10 extendidos (60% en aquellos con lesión de bajo grado y 38/39 biopsias (97.4% y 8/9 extendidos (89% en los grupos con lesión de alto grado y carcinoma escamoso. Todas las muestras con HPV-6/11 fueron negativas o positivas focales para p16, en tanto que aquellas con HPV-18 u otros subtipos fueron mayoritariamente positivas de tipo difuso. Concluimos que la expresión de p16 presenta alta correlación con el diagnóstico cito/histológico y alta asociación entre la marcación difusa y la presencia de HPV de alto riesgo, aportando mayor objetividad en casos dudosos y ayudando a seleccionar grupos de individuos con riesgo de progresión de enfermedad, con un costo aceptable para estudiar grandes grupos.Recent studies suggest that p16 overexpression determined by immunohistochemistry would be a specific marker for neoplastic and dysplastic squamous cells associated with high-risk HPV. The purpose of this study was to assess the correlation between cyto-histological findings, p16 expression and HPV subtype. A total of 99 biopsies were selected, 4 endocervical

  18. The effects of two polymorphisms on p21cip1 function and their association with Alzheimer's disease in a population of European descent.

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    Sharon C Yates

    Full Text Available With the exception of ApoE4, genome-wide association studies have failed to identify strong genetic risk factors for late-onset Alzheimer's disease, despite strong evidence of heritability, suggesting that many low penetrance genes may be involved. Additionally, the nature of the identified genetic risk factors and their relation to disease pathology is also largely obscure. Previous studies have found that a cancer-associated variant of the cell cycle inhibitor gene p21cip1 is associated with increased risk of Alzheimer's disease. The aim of this study was to confirm this association and to elucidate the effects of the variant on protein function and Alzheimer-type pathology. We examined the association of the p21cip1 variant with Alzheimer's disease and Parkinson's disease with dementia. The genotyping studies were performed on 719 participants of the Oxford Project to Investigate Memory and Ageing, 225 participants of a Parkinson's disease DNA bank, and 477 participants of the Human Random Control collection available from the European Collection of Cell Cultures. The post mortem studies were carried out on 190 participants. In the in-vitro study, human embryonic kidney cells were transfected with either the common or rare p21cip1 variant; and cytometry was used to assess cell cycle kinetics, p21cip1 protein expression and sub-cellular localisation. The variant was associated with an increased risk of Alzheimer's disease, and Parkinson's disease with dementia, relative to age matched controls. Furthermore, the variant was associated with an earlier age of onset of Alzheimer's disease, and a more severe phenotype, with a primary influence on the accumulation of tangle pathology. In the in-vitro study, we found that the SNPs reduced the cell cycle inhibitory and anti-apoptotic activity of p21cip1. The results suggest that the cancer-associated variant of p21cip1 may contribute to the loss of cell cycle control in neurons that may lead to

  19. Deficiency of cyclin-dependent kinase inhibitors p21Cip1 and p27Kip1 accelerates atherogenesis in apolipoprotein E-deficient mice

    International Nuclear Information System (INIS)

    Akyuerek, Levent M.; Boehm, Manfred; Olive, Michelle; Zhou, Alex-Xianghua; San, Hong; Nabel, Elizabeth G.

    2010-01-01

    Cyclin-dependent kinase inhibitors, p21 Cip1 and p27 Kip1 , are upregulated during vascular cell proliferation and negatively regulate growth of vascular cells. We hypothesized that absence of either p21 Cip1 or p27 Kip1 in apolipoprotein E (apoE)-deficiency may increase atherosclerotic plaque formation. Compared to apoE -/- aortae, both apoE -/- /p21 -/- and apoE -/- /p27 -/- aortae exhibited significantly more atherosclerotic plaque following a high-cholesterol regimen. This increase was particularly observed in the abdominal aortic regions. Deficiency of p27 Kip1 accelerated plaque formation significantly more than p21 -/- in apoE -/- mice. This increased plaque formation was in parallel with increased intima/media area ratios. Deficiency of p21 Cip1 and p27 Kip1 accelerates atherogenesis in apoE -/- mice. These findings have significant implications for our understanding of the molecular basis of atherosclerosis associated with excessive proliferation of vascular cells.

  20. Immunoexpression of P16INK4a, Rb and TP53 proteins in bronchiolar columnar cell dysplasia (BCCD in lungs resected due to primary non-small cell lung cancer.

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    Lech Chyczewski

    2008-02-01

    Full Text Available Lung cancer is the leading cause of death worldwide. High mortality comes out mainly of the fact that majority of the cases are diagnosed in advanced stadium. An expanded diagnostics of precancerous conditions would certainly contribute to lowering the mortality rate. Many of the molecular changes accompanying the multistep cancer development could be observed using the immunohistochemistry method. In this paper we describe the morphology and cell cycle proteins immunoexpression of the novel probable preinvasive lesion - bronchiolar columnar cell dysplasia (BCCD. Thirty cases of BCCD selected out of 193 patients population, treated for primary non-small cell lung cancer were investigated. Loss of P16INK4a protein was observed in 70% of all cases and was statistically significant in patients with adenocarcinoma. Two cases show abnormal cytoplasmic localization of this protein. TP53 protein accumulates in 26.7% of all BCCD. Rb protein was active in 48.3% of the BCCD cases. In two cases we observed differentiation of the cells composing BCCD into multilayer epithelium of the squamous type, which occurs with formation of desmosomes. We suppose that BCCD may be preneoplastic lesion leading to adenocarcinoma as well as to peripheral squamous cell lung cancer.

  1. Homologous regions of Fen1 and p21Cip1 compete for binding to the same site on PCNA: a potential mechanism to co-ordinate DNA replication and repair.

    Science.gov (United States)

    Warbrick, E; Lane, D P; Glover, D M; Cox, L S

    1997-05-15

    Following genomic damage, the cessation of DNA replication is co-ordinated with onset of DNA repair; this co-ordination is essential to avoid mutation and genomic instability. To investigate these phenomena, we have analysed proteins that interact with PCNA, which is required for both DNA replication and repair. One such protein is p21Cip1, which inhibits DNA replication through its interaction with PCNA, while allowing repair to continue. We have identified an interaction between PCNA and the structure specific nuclease, Fen1, which is involved in DNA replication. Deletion analysis suggests that p21Cip1 and Fen1 bind to the same region of PCNA. Within Fen1 and its homologues a small region (10 amino acids) is sufficient for PCNA binding, which contains an 8 amino acid conserved PCNA-binding motif. This motif shares critical residues with the PCNA-binding region of p21Cip1. A PCNA binding peptide from p21Cip1 competes with Fen1 peptides for binding to PCNA, disrupts the Fen1-PCNA complex in replicating cell extracts, and concomitantly inhibits DNA synthesis. Competition between homologous regions of Fen1 and p21Cip1 for binding to the same site on PCNA may provide a mechanism to co-ordinate the functions of PCNA in DNA replication and repair.

  2. Epigenetic changes in the CDKN2A locus are associated with differential expression of P16INK4A and P14ARF in HPV-positive oropharyngeal squamous cell carcinoma

    International Nuclear Information System (INIS)

    Schlecht, Nicolas F; Ben-Dayan, Miriam; Anayannis, Nicole; Lleras, Roberto A; Thomas, Carlos; Wang, Yanhua; Smith, Richard V; Burk, Robert D; Harris, Thomas M; Childs, Geoffrey; Ow, Thomas J; Prystowsky, Michael B; Belbin, Thomas J

    2015-01-01

    Human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma (OPSCC) is recognized as a distinct disease entity associated with improved survival. DNA hypermethylation profiles differ significantly by HPV status suggesting that a specific subset of methylated CpG loci could give mechanistic insight into HPV-driven OPSCC. We analyzed genome-wide DNA methylation of primary tumor samples and adjacent normal mucosa from 46 OPSCC patients undergoing treatment at Montefiore Medical Center, Bronx, NY using the Illumina HumanMethylation27 beadchip. For each matched tissue set, we measured differentially methylated CpG loci using a change in methylation level (M value). From these analyses, we identified a 22 CpG loci panel for HPV+ OPSCC that included four CDKN2A loci downstream of the p16(INK4A) and p14(ARF) transcription start sites. This panel was significantly associated with overall HPV detection (P < 0.05; ROC area under the curve = 0.96, 95% CI: 0.91–1.0) similar to the subset of four CDKN2A-specific CpG loci (0.90, 95% CI: 0.82–0.99) with equivalence to the full 22 CpG panel. DNA hypermethylation correlated with a significant increase in alternative open reading frame (ARF) expression in HPV+ OPSCC primary tumors, but not to the other transcript variant encoded by the CDKN2A locus. Overall, this study provides evidence of epigenetic changes to the downstream region of the CDKN2A locus in HPV+ oropharyngeal cancer that are associated with changes in expression of the coded protein products

  3. Translational Upregulation of an Individual p21Cip1 Transcript Variant by GCN2 Regulates Cell Proliferation and Survival under Nutrient Stress.

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    Stacey L Lehman

    2015-06-01

    Full Text Available Multiple transcripts encode for the cell cycle inhibitor p21(Cip1. These transcripts produce identical proteins but differ in their 5' untranslated regions (UTRs. Although several stresses that induce p21 have been characterized, the mechanisms regulating the individual transcript variants and their functional significance are unknown. Here we demonstrate through (35S labeling, luciferase reporter assays, and polysome transcript profiling that activation of the Integrated Stress Response (ISR kinase GCN2 selectively upregulates the translation of a p21 transcript variant containing 5' upstream open reading frames (uORFs through phosphorylation of the eukaryotic translation initiation factor eIF2α. Mutational analysis reveals that the uORFs suppress translation under basal conditions, but promote translation under stress. Functionally, ablation of p21 ameliorates G1/S arrest and reduces cell survival in response to GCN2 activation. These findings uncover a novel mechanism of p21 post-transcriptional regulation, offer functional significance for the existence of multiple p21 transcripts, and support a key role for GCN2 in regulating the cell cycle under stress.

  4. S-phase Specific Downregulation of Human O6-Methylguanine DNA Methyltransferase (MGMT and its Serendipitous Interactions with PCNA and p21cip1 Proteins in Glioma Cells

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    AGM Mostofa

    2018-04-01

    Full Text Available Whether the antimutagenic DNA repair protein MGMT works solo in human cells and if it has other cellular functions is not known. Here, we show that human MGMT associates with PCNA and in turn, with the cell cycle inhibitor, p21cip1 in glioblastoma and other cancer cell lines. MGMT protein was shown to harbor a nearly perfect PCNA-Interacting Protein (PIP box motif. Isogenic p53-null H1299 cells were engineered to express the p21 protein by two different procedures. Reciprocal immunoprecipitation/western blotting, Far-western blotting, and confocal microscopy confirmed the specific association of MGMT with PCNA and the ability of p21 to strongly disrupt the MGMT-PCNA complexes in tumor cells. Alkylation DNA damage resulted in a greater colocalization of MGMT and PCNA proteins, particularly in HCT116 cells deficient in p21 expression. p21 expression in isogenic cell lines directly correlated with markedly higher levels of MGMT mRNA, protein, activity and greater resistance to alkylating agents. In other experiments, four glioblastoma cell lines synchronized at the G1/S phase using either double thymidine or thymidine-mimosine blocks and subsequent cycling consistently showed a loss of MGMT protein at mid- to late S-phase, irrespective of the cell line, suggesting such a downregulation is fundamental to cell cycle control. MGMT protein was also specifically degraded in extracts from S-phase cells and evidence strongly suggested the involvement of PCNA-dependent CRL4Cdt2 ubiquitin-ligase in the reaction. Overall, these data provide the first evidence for non-repair functions of MGMT in cell cycle and highlight the involvement of PCNA in MGMT downregulation, with p21 attenuating the process.

  5. Involvement of Bmi-1 gene in the development of gastrointestinal stromal tumor by regulating p16Ink4A/p14ARF gene expressions: An in vivo and in vitro study.

    Science.gov (United States)

    Wang, Jiang-Li; Wu, Jiang-Hong; Hong, Cai; Wang, Ya-Nong; Zhou, Ye; Long, Zi-Wen; Zhou, Ying; Qin, Hai-Shu

    2017-12-01

    This study was conducted in order to explore the role that Bmi-1 plays during the development of a gastrointestinal stromal tumor (GIST) by regulation of the p16 Ink4A and p14 ARF expressions. Eighty-six patients diagnosed with GIST were selected to take part in this experiment. The Bmi-1 protein expressions in GIST and adjacent normal tissues were detected using immunohistochemistry and further analyzed by using photodensitometry. To monitor and track the progression of the GIST, a 3-year follow-up was conducted for all affected patients. After cell transfection, the GIST cells were assigned into the control group (without transfection), the negative control (NC) group (transfected with Bmi-1-Scramble plasmid), and the Bmi-1 shRNA group (transfected with the pcDNA3.1-Bmi-1 shRNA plasmid). Protein and mRNA expressions collected from Bmi-1, p16 lnk4A , P14 ARF , cyclin D1, and CDK4 were measured using both the RT-qPCR and western blotting methods Cell senescence was assessed and obtained by using the β-Galactosidase (β-Gal) activity assay. The use of a Soft agar colony formation assay and CCK-8 assay were performed in order to detect the cell growth and subsequent proliferation. Cell invasion and migration were analyzed using the Transwell assay and scratch test. Bmi-1 in the GIST tissues was found to be significantly higher and the p16 lnk4A and P14 ARF expressions were lower than those in the adjacent normal tissues. Bmi-1 was negatively correlated with p16 lnk4A and P14 ARF expressions according to the correlation analysis. Bmi-1 expression was associated with the TNM stage, postoperative recurrence, metastasis, tumor size, and the 5-year survival rate. Area under ROC curve was calculated at 0.884, and sensitivity, specificity, and accuracy of Bmi-1 predicting the GIST were 67.44%, 97.67%, and 65.12%, respectively. Patients exhibiting a high Bmi-1 expression in the GIST tissues had lower survival rates than those with low Bmi-1 expression. In comparison with

  6. Anti-proliferative and pro-apoptotic activity of whole extract and isolated indicaxanthin from Opuntia ficus-indica associated with re-activation of the onco-suppressor p16INK4a gene in human colorectal carcinoma (Caco-2) cells

    International Nuclear Information System (INIS)

    Naselli, Flores; Tesoriere, Luisa; Caradonna, Fabio; Bellavia, Daniele; Attanzio, Alessandro; Gentile, Carla; Livrea, Maria A.

    2014-01-01

    Highlights: • Cactus pear fruit extract and indicaxanthin cause apoptosis of colon cancer cells. • Indicaxanthin does not cause ROS formation, but affects epigenoma in Caco-2 cells. • Indicaxanthin reverses methylation of oncosuppressor p16 INK4a gene in Caco-2 cells. • Indicaxanthin reactivates retinoblastoma in Caco-2 cells. • Bioavailable indicaxanthin may have chemopreventive activity in colon cancer. - Abstract: Phytochemicals may exert chemo-preventive effects on cells of the gastro-intestinal tract by modulating epigenome-regulated gene expression. The effect of the aqueous extract from the edible fruit of Opuntia ficus-indica (OFI extract), and of its betalain pigment indicaxanthin (Ind), on proliferation of human colon cancer Caco-2 cells has been investigated. Whole extract and Ind caused a dose-dependent apoptosis of proliferating cells at nutritionally relevant amounts, with IC 50 400 ± 25 mg fresh pulp equivalents/mL, and 115 ± 15 μM (n = 9), respectively, without toxicity for post-confluent differentiated cells. Ind accounted for ∼80% of the effect of the whole extract. Ind did not cause oxidative stress in proliferating Caco-2 cells. Epigenomic activity of Ind was evident as de-methylation of the tumor suppressor p16 INK4a gene promoter, reactivation of the silenced mRNA expression and accumulation of p16 INK4a , a major controller of cell cycle. As a consequence, decrease of hyper-phosphorylated, in favor of the hypo-phosphorylated retinoblastoma was observed, with unaltered level of the cycline-dependent kinase CDK4. Cell cycle showed arrest in the G2/M-phase. Dietary cactus pear fruit and Ind may have chemo-preventive potential in intestinal cells

  7. Anti-proliferative and pro-apoptotic activity of whole extract and isolated indicaxanthin from Opuntia ficus-indica associated with re-activation of the onco-suppressor p16(INK4a) gene in human colorectal carcinoma (Caco-2) cells.

    Science.gov (United States)

    Naselli, Flores; Tesoriere, Luisa; Caradonna, Fabio; Bellavia, Daniele; Attanzio, Alessandro; Gentile, Carla; Livrea, Maria A

    2014-07-18

    Phytochemicals may exert chemo-preventive effects on cells of the gastro-intestinal tract by modulating epigenome-regulated gene expression. The effect of the aqueous extract from the edible fruit of Opuntia ficus-indica (OFI extract), and of its betalain pigment indicaxanthin (Ind), on proliferation of human colon cancer Caco-2 cells has been investigated. Whole extract and Ind caused a dose-dependent apoptosis of proliferating cells at nutritionally relevant amounts, with IC50 400±25 mg fresh pulp equivalents/mL, and 115±15 μM (n=9), respectively, without toxicity for post-confluent differentiated cells. Ind accounted for ∼80% of the effect of the whole extract. Ind did not cause oxidative stress in proliferating Caco-2 cells. Epigenomic activity of Ind was evident as de-methylation of the tumor suppressor p16(INK4a) gene promoter, reactivation of the silenced mRNA expression and accumulation of p16(INK4a), a major controller of cell cycle. As a consequence, decrease of hyper-phosphorylated, in favor of the hypo-phosphorylated retinoblastoma was observed, with unaltered level of the cycline-dependent kinase CDK4. Cell cycle showed arrest in the G2/M-phase. Dietary cactus pear fruit and Ind may have chemo-preventive potential in intestinal cells. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Estudo de p27, p21, p16 em epitélio escamoso normal, papiloma escamoso e carcinoma de células escamosas da cavidade oral Comparative analysis of the immunohistochemistry expression of p27, p21WAF/Cip1, and p16INK4a in oral normal epithelium, squamous papilloma and squamous cell carcinoma

    Directory of Open Access Journals (Sweden)

    Ana Beatriz Piazza Queiroz

    2009-12-01

    Full Text Available INTRODUÇÃO E OBJETIVO: O tipo de câncer oral mais frequente é o carcinoma de células escamosas, que corresponde a 95% dos casos(9. O papiloma escamoso oral é uma neoplasia benigna normalmente associada à infecção pelo papilomavírus humano (HPV(21. A análise da literatura mostra alterações nos genes reguladores do ciclo celular p27, p21WAF/Cip1 e p16INK4a, porém sem uma definição de seus papéis na carcinogênese oral. O objetivo foi caracterizar imuno-histoquimicamente p27, p21WAF/Cip1 e p16NK4a em epitélio escamoso normal, papilomas escamosos e carcinomas de células escamosas da cavidade oral. MÉTODOS: Imuno-histoquímica para p27, p21WAF/Cip1 e p16NK4a em 32 casos de epitélio escamoso normal, 30 casos de papiloma escamoso e 34 de carcinoma de células escamosas da cavidade oral. RESULTADOS: p27: 97,06% dos casos de carcinoma de células escamosas apresentaram imunopositividade focal. O grupo papiloma escamoso apresentou 33,33% e o grupo controle, 18,75%. p21WAF/Cip1: 100% de imunopositividade focal tanto no grupo controle como no grupo carcinoma de células escamosas, e 90% no grupo papiloma escamoso. p16INK4a: 100% de imunopositividade focal para os grupos controle e papiloma escamoso, e 94% para o grupo carcinoma de células escamosas. CONCLUSÃO: Imuno-histoquimicamente demonstrou-se diferença significativa para p27 quando feita comparação dos grupos controle e papiloma escamoso com o grupo carcinoma de células escamosas. O p21WAF/Cip1 não demonstrou poder de diferenciar os grupos analisados. O p16INK4a apresentou imunopositividade difusa em uma minoria dos casos do grupo carcinoma de células escamosas. O grupo papiloma escamoso se comportou de maneira similar ao grupo controle em relação aos três marcadores.INTRODUCTION: The most frequent type of oral cancer is the squamous cell carcinoma, which corresponds to 95% of the cases(9.The oral squamous papilloma is a benign neoplasia, commonly associated with

  9. Cell-penetrating superoxide dismutase attenuates oxidative stress-induced senescence by regulating the p53-p21Cip1 pathway and restores osteoblastic differentiation in human dental pulp stem cells

    Directory of Open Access Journals (Sweden)

    Park YJ

    2012-09-01

    Full Text Available Yoon Jung Choi,1,* Jue Yeon Lee,2,* Chong Pyoung Chung,2 Yoon Jeong Park,1,21Craniomaxillofacial Reconstructive Sciences, Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea; 2Research Institute, Nano Intelligent Biomedical Engineering, Seoul, Republic of Korea*These authors contributed equally to this workBackground: Human dental pulp stem cells (DPSCs have potential applications in tissue regeneration because of their convenient cell harvesting procedures and multipotent capacity. However, the tissue regenerative potential of DPSCs is known to be negatively regulated by aging in long-term culture and under oxidative stress. With an aim of reducing cellular senescence and oxidative stress in DPSCs, an intracellular delivery system for superoxide dismutase 1 (SOD1 was developed. We conjugated SOD1 with a cell-penetrating peptide known as low-molecular weight protamine (LMWP, and investigated the effect of LMWP-SOD1 conjugates on hydrogen peroxide-induced cellular senescence and osteoblastic differentiation.Results: LMWP-SOD1 significantly attenuated enlarged and flattened cell morphology and increased senescence-associated β-galactosidase activity. Under the same conditions, LMWP-SOD1 abolished activation of the cell cycle regulator proteins, p53 and p21Cip1, induced by hydrogen peroxide. In addition, LMWP-SOD1 reversed the inhibition of osteoblastic differentiation and downregulation of osteogenic gene markers induced by hydrogen peroxide. However, LMWP-SOD1 could not reverse the decrease in odontogenesis caused by hydrogen peroxide.Conclusion: Overall, cell-penetrating LMWP-SOD1 conjugates are effective for attenuation of cellular senescence and reversal of osteoblastic differentiation of DPSCs caused by oxidative stress inhibition. This result suggests potential application in the field of antiaging and tissue engineering to overcome the limitations of senescent stem cells.Keywords: superoxide

  10. Eukaryotic translation initiator protein 1A isoform, CCS-3, enhances the transcriptional repression of p21CIP1 by proto-oncogene FBI-1 (Pokemon/ZBTB7A).

    Science.gov (United States)

    Choi, Won-Il; Kim, Youngsoo; Kim, Yuri; Yu, Mi-young; Park, Jungeun; Lee, Choong-Eun; Jeon, Bu-Nam; Koh, Dong-In; Hur, Man-Wook

    2009-01-01

    FBI-1, a member of the POK (POZ and Kruppel) family of transcription factors, plays a role in differentiation, oncogenesis, and adipogenesis. eEF1A is a eukaryotic translation elongation factor involved in several cellular processes including embryogenesis, oncogenic transformation, cell proliferation, and cytoskeletal organization. CCS-3, a potential cervical cancer suppressor, is an isoform of eEF1A. We found that eEF1A forms a complex with FBI-1 by co-immunoprecipitation, SDS-PAGE, and MALDI-TOF Mass analysis of the immunoprecipitate. GST fusion protein pull-downs showed that FBI-1 directly interacts with eEF1A and CCS-3 via the zinc finger and POZ-domain of FBI-1. FBI-1 co-localizes with either eEF1A or CCS-3 at the nuclear periplasm. CCS-3 enhances transcriptional repression of the p21CIP1 gene (hereafter referred to as p21) by FBI-1. The POZ-domain of FBI-1 interacts with the co-repressors, SMRT and BCoR. We found that CCS-3 also interacts with the co-repressors independently. The molecular interaction between the co-repressors and CCS-3 at the POZ-domain of FBI-1 appears to enhance FBI-1 mediated transcriptional repression. Our data suggest that CCS-3 may be important in cell differentiation, tumorigenesis, and oncogenesis by interacting with the proto-oncogene FBI-1 and transcriptional co-repressors. Copyright 2009 S. Karger AG, Basel.

  11. Overexpression of cell cycle regulator CDCA3 promotes oral cancer progression by enhancing cell proliferation with prevention of G1 phase arrest

    International Nuclear Information System (INIS)

    Uchida, Fumihiko; Uzawa, Katsuhiro; Kasamatsu, Atsushi; Takatori, Hiroaki; Sakamoto, Yosuke; Ogawara, Katsunori; Shiiba, Masashi; Tanzawa, Hideki; Bukawa, Hiroki

    2012-01-01

    Cell division cycle associated 3 (CDCA3), part of the Skp1-cullin-F-box (SCF) ubiquitin ligase, refers to a trigger of mitotic entry and mediates destruction of the mitosis inhibitory kinase. Little is known about the relevance of CDCA3 to human malignancy including oral squamous cell carcinoma (OSCC). We aimed to characterize the expression state and function of CDCA3 in OSCC. We evaluated CDCA3 mRNA and protein expression in both OSCC-derived cell lines and primary OSCCs and performed functional analyses of CDCA3 in OSCC-derived cells using the shRNA system. The CDCA3 expression at both the mRNA and protein levels was frequently up-regulated in all cell lines examined and primary tumors (mRNA, 51/69, 74 %; protein, 79/95, 83 %) compared to normal controls (p < 0.001). In contrast, no significant level of CDCA3 protein expression was seen in oral premalignant lesions (OPLs) (n = 20) compared with the expression in OSCCs. Among the clinical variables analyzed, the CDCA3 expression status was closely related to tumor size (p < 0.05). In addition, suppression of CDCA3 expression with shRNA significantly (p < 0.05) inhibited cellular proliferation compared with the control cells by arresting cell-cycle progression at the G1 phase. Further, there was up-regulation of the cyclin-dependent kinase inhibitors (p21 Cip1 , p27 Kip1 , p15 INK4B , and p16 INK4A ) in the knockdown cells. The current results showed that overexpression of CDCA3 occurs frequently during oral carcinogenesis and this overexpression might be associated closely with progression of OSCCs by preventing the arrest of cell-cycle progression at the G1 phase via decreased expression of the cyclin-dependent kinase inhibitors

  12. How to measure RNA expression in rare senescent cells expressing any specific protein such as p16Ink4a.

    Science.gov (United States)

    Jeyapalan, Jessie C; Sedivy, John M

    2013-02-01

    Here we describe a carefully optimized method for the preparation of high quality RNA by flow sorting of formaldehyde fixed senescent cells immunostained for any intracellular antigen. Replicative cellular senescence is a phenomenon of irreversible growth arrest triggered by the accumulation of a discrete number of cell divisions. The underlying cause of senescence due to replicative exhaustion is telomere shortening. We document here a spontaneous and apparently stochastic process that continuously generates senescent cells in cultures fully immortalized with telomerase. In the course of studying this phenomenon we developed a preparative fluorescence activated flow sorting method based on immunofluorescent staining of intracellular antigens that can also deliver RNA suitable for quantitative analysis of global gene expression. The protocols were developed using normal human diploid fibroblasts (HDF) and up to 5x107 cells could be conveniently processed in a single experiment. The methodology is based on formaldehyde crosslinking of cells, followed by permeabilization, antibody staining, flow sorting, reversal of the crosslinks, and recovery of the RNA. We explored key parameters such as crosslink reversal that affect the fragmentation of RNA. The recovered RNA is of high quality for downstream molecular applications based on short range sequence analysis, such qPCR, hybridization microarrays, and next generation sequencing. The RNA was analyzed by Affymetrix Gene Chip expression profiling and compared to RNA prepared by the direct lysis of cells. The correlation between the data sets was very high, indicating that the procedure does not introduce systematic changes in the mRNA transcriptome. The methods presented in this communication should be of interest to many investigators working in diverse model systems.

  13. Identification of target genes of the p16INK4A-pRB-E2F pathway

    DEFF Research Database (Denmark)

    Vernell, Richard; Helin, Kristian; Müller, Heiko

    2003-01-01

    as physiological targets of the pRB pathway, and the further characterization of these genes should provide insights into how this pathway controls proliferation. We show that Gibbs sampling detects enrichment of several sequence motifs, including E2F consensus binding sites, in the upstream regions of these genes...

  14. "Primary Squamous Cell Carcinoma of the Vagina: HPV Detection, p16INK4A Overexpression and Clinicopathological Correlations"

    OpenAIRE

    Fuste , Victoria; Del Pino , Marta; Perez , Assumpta; Garcia , Angel; Torne , Aureli; Pahisa , Jaume; Ordi , Jaume

    2010-01-01

    Abstract Aim: To determine the role of HPV in the pathogenesis of primary squamous cell carcinoma of the vagina (SCCVa), and to evaluate its clinico-pathological significance. Methods: All cases of SCCVa diagnosed over a 15 year period from two hospitals in Barcelona, Spain (n=32) were retrieved. Patients with a history of carcinoma of the cervix diagnosed less than 5 years before were excluded. HPV was detected and typed by PCR using the SPF10 primers. Immunohistochemistry for...

  15. Deregulated expression of E2F family members induces S-phase entry and overcomes p16INK4A-mediated growth suppression

    DEFF Research Database (Denmark)

    Lukas, J; Petersen, B O; Holm, K

    1996-01-01

    The E2F family of transcription factors regulate genes, whose products are essential for progression through the mammalian cell cycle. The transcriptional activity of the E2Fs is inhibited through the specific binding of the retinoblastoma protein, pRB, and the pRB homologs p107 and p130 to their......The E2F family of transcription factors regulate genes, whose products are essential for progression through the mammalian cell cycle. The transcriptional activity of the E2Fs is inhibited through the specific binding of the retinoblastoma protein, pRB, and the pRB homologs p107 and p130...

  16. TMEM45A, SERPINB5 and p16INK4A transcript levels are predictive for development of high-grade cervical lesions

    DEFF Research Database (Denmark)

    Manawapat-Klopfer, Anna; Thomsen, Louise T; Martus, Peter

    2016-01-01

    Women persistently infected with human papillomavirus (HPV) type 16 are at high risk for development of cervical intraepithelial neoplasia grade 3 or cervical cancer (CIN3+). We aimed to identify biomarkers for progression to CIN3+ in women with persistent HPV16 infection. In this prospective study......, 11,088 women aged 20-29 years were enrolled during 1991-1993, and re-invited for a second visit two years later. Cervical cytology samples obtained at both visits were tested for HPV DNA by Hybrid Capture 2 (HC2), and HC2-positive samples were genotyped by INNO-LiPA. The cohort was followed for up...... to 19 years via a national pathology register. To identify markers for progression to CIN3+, we performed microarray analysis on RNA extracted from cervical swabs of 30 women with persistent HPV16-infection and 11 HPV-negative women. Six genes were selected and validated by quantitative PCR. Three genes...

  17. The negative predictive value of p16INK4a to assess the outcome of cervical intraepithelial neoplasia 1 in the uterine cervix

    DEFF Research Database (Denmark)

    Hariri, Jalil; Øster, Anne

    2007-01-01

    The immunohistochemical expression of p16 in formalin-fixed and paraffin-embedded histological sections was evaluated in a retrospective study comprising a low-grade group of 100 cases of cervical intraepithelial neoplasia (CIN) 1, a high-grade group of 50 cases of CIN 2 to 3, and a benign group...

  18. Epithelial cells derived from human embryonic stem cells display p16INK4A senescence, hypermotility, and differentiation properties shared by many P63+ somatic cell types

    DEFF Research Database (Denmark)

    Dabelsteen, Sally; Hercule, Paula; Barron, Patricia

    2009-01-01

    hESderK cells and keratinocytes a substantially extended lifespan. When exposed to transforming growth factor beta or to an incompletely processed form of Laminin-332, three lifespan-extended or immortalized hESderK lines that we studied became directionally hypermotile, a wound healing and invasion......(+)/K14(+) urothelial and tracheobronchial epithelial cells. Primary and immortalized lines of these cell types had growth requirements and hypermotility responses similar to keratinocytes and bmi1 expression facilitated their immortalization by engineering to express the catalytic subunit of telomerase...

  19. Modifications in cell cycle kinetics and in expression of G1 phase-regulating proteins in human amniotic cells after exposure to electromagnetic fields and ionizing radiation.

    Science.gov (United States)

    Lange, S; Viergutz, T; Simkó, M

    2004-10-01

    Low-frequency electromagnetic fields are suspected of being involved in carcinogenesis, particularly in processes that could be related to cancer promotion. Because development of cancer is associated with deregulated cell growth and we previously observed a magnetic field-induced decrease in DNA synthesis [Lange et al. (2002) Alterations in the cell cycle and in the protein level of cyclin D1p, 21CIP1, and p16INK4a after exposure to 50 HZ. MF in human cells. Radiat. Environ. Biophys.41, 131], this study aims to document the influence of 50 Hz, 1 mT magnetic fields (MF), with or without initial gamma-ionizing radiation (IR), on the following cell proliferation-relevant parameters in human amniotic fluid cells (AFC): cell cycle distribution, expression of the G1 phase-regulating proteins Cdk4, cyclin D1, p21CIP1 and p16INK4a, and Cdk4 activity. While IR induced a G1 delay and a dose-dependent G2 arrest, no discernible changes in cell cycle kinetics were observed due to MF exposure. However, a significant decrease in the protein expression of cyclin D1 and an increase in p21CIP1- and p16INK4a-expression could be detected after exposure to MF alone. IR-exposure caused an augmentation of p21CIP1- and p16INK4a- levels as well, but did not alter cyclin D1 expression. A slight diminution of Cdk4 activity was noticed after MF exposure only, indicating that Cdk4 appears not to act as a mediator of MF- or IR-induced changes in the cell cycle of AFC cells. Co-exposure to MF/IR affected neither cell cycle distribution nor protein expression or kinase activity additionally or synergistically, and therefore MF seems not to modify the mutagenic potency of IR.

  20. Different domains of P21Cip1/waf1 regulate DNA replication and DNA repair-associated processes after UV

    International Nuclear Information System (INIS)

    Soria, Gaston; Speroni, Juliana; Podhajcer, Osvaldo L.; Gottifredi, Vanesa; Prives, Carol

    2007-01-01

    Full text: Many genotoxic insults result in p21 up-regulation and p21-dependent cell cycle arrest but UV irradiation triggers p21 proteolysis. The significance of the increased p21 turnover is unclear and might be associated to DNA repair. While the role of p21 in Nucleotide Excision Repair (NER) remains controversial, two recent reports explore its effect on Translesion DNA Synthesis (TLS), a process that avoids replication blockage during S phase. The first report shows that p21 degradation is required for efficient PCNA ubiquitination, a post transcriptional modification that is relevant for TLS. The second report demonstrates that p21 (-/-) cells have increased TLS-associated mutagenic rates. Herein we analyze the effect of p21 on different PCNA-driven processes including DNA replication, NER and TLS. Whereas only the CDK binding domain of p21 is required for cell cycle arrest in unstressed cells; neither the CDK- nor the PCNA-binding domains of p21 are able to block early and late steps of NER. Intriguingly, through its PCNA binding domain, p21 inhibited recruitment of the TLS-polymerase, polη to PCNA foci after UV. Moreover, this obstruction correlates with accumulation of γH2AX and increased apoptosis. Taking together, our data emphasizes the link between p21 turnover and efficient TLS. This might also suggest a potential effect of p21 on other activities of polζ, a DNA polymerase with central roles in other biological scenarios such as genetic conversion, homologous recombination and modulation of the cellular response to genotoxic agents [es

  1. Cell Cycle Inhibitors and Outcome after Radiotherapy in Bladder Cancer Patients

    International Nuclear Information System (INIS)

    Roetterud, Ranveig; Pettersen, Erik O.; Berner, Aasmund; Holm, Ruth; Olsen, Dag Rune; Fossaa, Sophie D.

    2002-01-01

    The aim of this study was to correlate the expression of cell cycle inhibitors with outcome of patients with muscle-invasive bladder cancer treated with preoperative radiotherapy (46 Gy/4-5 weeks or 20 Gy/1 week) and cystectomy. Patients with pT3b (n=42) or pT0 (n=17) were included in the study. Expression of p16INK4a and p27KIP1 was assessed immunohistochemically in pre-radiotherapy biopsies and cystectomy specimens. Previously reported results of p21CIP1 expression were also included. No difference in pretreatment protein expression was found between patients with pT0 and pT3b. Expression of p21CIP1 and p27KIP1 was lower in cystectomy specimens than in pretreatment biopsies. None of the proteins showed significant impact on survival when analysed separately. However, patients with tumours showing > 50% expression of p16INK4a, p21CIP1, or p27KIP1 displayed poorer cancer-specific survival rates compared with the remaining patients (p=0.025). This effect was more pronounced in patients receiving 46 Gy than in those receiving 20 Gy. In conclusion, low expression of cell cycle inhibitors is related to favourable survival after precystectomy radiotherapy

  2. Evaluation of p16INK4a/Ki-67 dual stain in comparison with an mRNA human papillomavirus test on liquid-based cytology samples with low-grade squamous intraepithelial lesion

    DEFF Research Database (Denmark)

    Waldstrom, M.; Christensen, R. K.; Ornskov, D.

    2013-01-01

    with significantly lower values than the CINtec PLUS test. For patients with CIN2+, the APTIMA HPV Assay had a specificity of 36.1% versus 51.3% for the CINtec PLUS test, and for women with CIN3+, the specificity was 33.8% versus 48.2%, respectively. The difference was even more pronounced when analyzing women aged...... sensitivity that was similar to that of the APTIMA HPV Assay in the detection of underlying high-grade disease but with enhanced specificity, especially among women aged

  3. Senescence-associated heterochromatin foci are dispensable for cellular senescence, occur in a cell type- and insult-dependent manner, and follow expression of p16 (ink4a)

    Czech Academy of Sciences Publication Activity Database

    Košař, Martin; Bartkova, J.; Hubáčková, Soňa; Hodný, Zdeněk; Lukas, J.; Bartek, Jiří

    2011-01-01

    Roč. 10, č. 3 (2011), s. 457-468 ISSN 1538-4101 R&D Projects: GA ČR GA204/08/1418; GA ČR GA301/08/0353 Institutional research plan: CEZ:AV0Z50520514 Keywords : genotoxic and replicative stress * senescence-associated heterochromatin foci * DNA damage response Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.359, year: 2011

  4. Immunostaining of p16INK4a/Ki-67 and L1 Capsid Protein on Liquid-based Cytology Specimens Obtained from ASC-H and LSIL-H Cases

    OpenAIRE

    Byun, Seung Won; Lee, Ahwon; Kim, Suyeon; Choi, Yeong Jin; Lee, Youn Soo; Park, Jong Sup

    2013-01-01

    Background: Atypical squamous cell cannot exclude high-grade squamous intraepithelial lesion (ASC-H) and low-grade intraepithelial lesion cannot exclude high-grade squamous intraepithelial lesion (LSIL-H) are ambiguous diagnostic entities for the prediction of high-grade cervical lesion. Objective and reproducible tests for predicting high-grade cervical lesions are needed to reduce unnecessary colposcopic referrals or follow-ups. Objective: We aimed to identify an adequate set of adjunctive ...

  5. Both p53-PUMA/NOXA-Bax-mitochondrion and p53-p21cip1 pathways are involved in the CDglyTK-mediated tumor cell suppression

    International Nuclear Information System (INIS)

    Yu, Zhendong; Wang, Hao; Zhang, Libin; Tang, Aifa; Zhai, Qinna; Wen, Jianxiang; Yao, Li; Li, Pengfei

    2009-01-01

    CDglyTK fusion suicide gene has been well characterized to effectively kill tumor cells. However, the exact mechanism and downstream target genes are not fully understood. In our study, we found that CDglyTK/prodrug treatment works more efficiently in p53 wild-type (HONE1) cells than in p53 mutant (CNE1) cells. We then used adenovirus-mediated gene delivery system to either knockdown or overexpress p53 and its target genes in these cells. Consistent results showed that both p53-PUMA/NOXA/Bcl2-Bax and p53-p21 pathways contribute to the CDglyTK induced tumor cell suppression. Our work for the first time addressed the role of p53 related genes in the CDglyTK/prodrug system.

  6. H2O2 induces a transient multi-phase cell cycle arrest in mouse fibroblasts through modulating cyclin D and p21Cip1 expression

    NARCIS (Netherlands)

    Barnouin, K.; Dubuisson, M.L.; Child, E.S.; Fernandez de Mattos, S.; Glassford, J.; Medema, R.H.; Mann, D.J.; Lam, E.W.-F.

    2002-01-01

    From the h CRC Laboratories and the Section of Cancer Cell Biology, Imperial College School of Medicine at Hammersmith Hospital, Du Cane Road, London W12 ONN, United Kingdom, the e Ludwig Institute for Cancer Research and Section of Virology and Cell Biology, Imperial College School of Medicine at

  7. Both p53-PUMA/NOXA-Bax-mitochondrion and p53-p21cip1 pathways are involved in the CDglyTK-mediated tumor cell suppression

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Zhendong, E-mail: zdyu@hotmail.com [Department of Clinical laboratory, Peking University Shenzhen Hospital, Guangdong (China); Wang, Hao [Department of pathology, The Chinese University of Hong Kong, Hong Kong (China); Zhang, Libin; Tang, Aifa; Zhai, Qinna; Wen, Jianxiang; Yao, Li [Department of Clinical laboratory, Peking University Shenzhen Hospital, Guangdong (China); Li, Pengfei, E-mail: lipengfei@cuhk.edu.hk [Department of pathology, The Chinese University of Hong Kong, Hong Kong (China)

    2009-09-04

    CDglyTK fusion suicide gene has been well characterized to effectively kill tumor cells. However, the exact mechanism and downstream target genes are not fully understood. In our study, we found that CDglyTK/prodrug treatment works more efficiently in p53 wild-type (HONE1) cells than in p53 mutant (CNE1) cells. We then used adenovirus-mediated gene delivery system to either knockdown or overexpress p53 and its target genes in these cells. Consistent results showed that both p53-PUMA/NOXA/Bcl2-Bax and p53-p21 pathways contribute to the CDglyTK induced tumor cell suppression. Our work for the first time addressed the role of p53 related genes in the CDglyTK/prodrug system.

  8. Losses of both products of the Cdkn2a/Arf locus contribute to asbestos-induced mesothelioma development and cooperate to accelerate tumorigenesis.

    Directory of Open Access Journals (Sweden)

    Deborah A Altomare

    2011-04-01

    Full Text Available The CDKN2A/ARF locus encompasses overlapping tumor suppressor genes p16(INK4A and p14(ARF, which are frequently co-deleted in human malignant mesothelioma (MM. The importance of p16(INK4A loss in human cancer is well established, but the relative significance of p14(ARF loss has been debated. The tumor predisposition of mice singly deficient for either Ink4a or Arf, due to targeting of exons 1α or 1β, respectively, supports the idea that both play significant and nonredundant roles in suppressing spontaneous tumors. To further test this notion, we exposed Ink4a(+/- and Arf(+/- mice to asbestos, the major cause of MM. Asbestos-treated Ink4a(+/- and Arf(+/- mice showed increased incidence and shorter latency of MM relative to wild-type littermates. MMs from Ink4a(+/- mice exhibited biallelic inactivation of Ink4a, loss of Arf or p53 expression and frequent loss of p15(Ink4b. In contrast, MMs from Arf(+/- mice exhibited loss of Arf expression, but did not require loss of Ink4a or Ink4b. Mice doubly deficient for Ink4a and Arf, due to deletion of Cdkn2a/Arf exon 2, showed accelerated asbestos-induced MM formation relative to mice deficient for Ink4a or Arf alone, and MMs exhibited biallelic loss of both tumor suppressor genes. The tumor suppressor function of Arf in MM was p53-independent, since MMs with loss of Arf retained functional p53. Collectively, these in vivo data indicate that both CDKN2A/ARF gene products suppress asbestos carcinogenicity. Furthermore, while inactivation of Arf appears to be crucial for MM pathogenesis, the inactivation of both p16(Ink4a and p19(Arf cooperate to accelerate asbestos-induced tumorigenesis.

  9. Differential Cellular and Molecular Effects of Butyrate and Trichostatin A on Vascular Smooth Muscle Cells

    Directory of Open Access Journals (Sweden)

    Kasturi Ranganna

    2012-09-01

    Full Text Available The histone deacetylase (HDAC inhibitors, butyrate and trichostatin A (TSA, are epigenetic histone modifiers and proliferation inhibitors by downregulating cyclin D1, a positive cell cycle regulator, and upregulating p21Cip1 and INK family of proteins, negative cell cycle regulators. Our recent study indicated cyclin D1 upregulation in vascular smooth muscle cells (VSMC that are proliferation-arrested by butyrate. Here we investigate whether cyclin D1 upregulation is a unique response of VSMC to butyrate or a general response to HDAC inhibitors (HDACi by evaluating the effects of butyrate and TSA on VSMC. While butyrate and TSA inhibit VSMC proliferation via cytostatic and cytotoxic effects, respectively, they downregulate cdk4, cdk6, and cdk2, and upregulate cyclin D3, p21Cip1 and p15INK4B, and cause similar effects on key histone H3 posttranslational modifications. Conversely, cyclin D1 is upregulated by butyrate and inhibited by TSA. Assessment of glycogen synthase 3-dependent phosphorylation, subcellular localization and transcription of cyclin D1 indicates that differential effects of butyrate and TSA on cyclin D1 levels are linked to disparity in cyclin D1 gene expression. Disparity in butyrate- and TSA-induced cyclin D1 may influence transcriptional regulation of genes that are associated with changes in cellular morphology/cellular effects that these HDACi confer on VSMC, as a transcriptional modulator.

  10. Cell-cycle regulatory proteins in human wound healing

    DEFF Research Database (Denmark)

    Bartkova, Jirina; Grøn, Birgitte; Dabelsteen, Erik

    2003-01-01

    Proper healing of mucosal wounds requires careful orchestration of epithelial cell migration and proliferation. To elucidate the molecular basis of the lack of cellular proliferation in the migrating 'epithelial tongue' during the re-epithelialization of oral mucosal wounds, the expression of cell......-cycle regulators critical for G(1)-phase progression and S-phase entry was here analysed immunohistochemically. Compared to normal human mucosa, epithelia migrating to cover 2- or 3-day-old wounds made either in vivo or in an organotypic cell culture all showed loss of the proliferation marker Ki67 and cyclins D(1......) and A, and reduced expression of cyclins D(3) and E, the cyclin D-dependent kinase 4 (CDK4), the MCM7 component of DNA replication origin complexes and the retinoblastoma protein pRb. Among the CDK inhibitors (CKIs), p16ink4a and p21Cip1 were moderately increased and decreased, respectively, whereas...

  11. 3,3'-Diindolylmethane is a novel mitochondrial H(+)-ATP synthase inhibitor that can induce p21(Cip1/Waf1) expression by induction of oxidative stress in human breast cancer cells.

    Science.gov (United States)

    Gong, Yixuan; Sohn, Heesook; Xue, Ling; Firestone, Gary L; Bjeldanes, Leonard F

    2006-05-01

    Epidemiologic evidence suggests that high dietary intake of Brassica vegetables, such as broccoli, cabbage, and Brussels sprouts, protects against tumorigenesis in multiple organs. 3,3'-Diindolylmethane, one of the active products derived from Brassica vegetables, is a promising antitumor agent. Previous studies in our laboratory showed that 3,3'-diindolylmethane induced a G(1) cell cycle arrest in human breast cancer MCF-7 cells by a mechanism that included increased expression of p21. In the present study, the upstream events leading to p21 overexpression were further investigated. We show for the first time that 3,3'-diindolylmethane is a strong mitochondrial H(+)-ATPase inhibitor (IC(50) approximately 20 micromol/L). 3,3'-Diindolylmethane treatment induced hyperpolarization of mitochondrial inner membrane, decreased cellular ATP level, and significantly stimulated mitochondrial reactive oxygen species (ROS) production. ROS production, in turn, led to the activation of stress-activated pathways involving p38 and c-Jun NH(2)-terminal kinase. Using specific kinase inhibitors (SB203580 and SP600125), we showed the central role of p38 and c-Jun NH(2)-terminal kinase (JNK) pathways in 3,3'-diindolylmethane-induced p21 mRNA transcription. In addition, antioxidants significantly attenuated 3,3'-diindolylmethane-induced activation of p38 and JNK and induction of p21, indicating that oxidative stress is the major trigger of these events. To further support the role of ROS in 3,3'-diindolylmethane-induced p21 overexpression, we showed that 3,3'-diindolylmethane failed to induce p21 overexpression in mitochondrial respiratory chain deficient rho(0) MCF-7 cells, in which 3,3'-diindolylmethane did not stimulate ROS production. Thus, we have established the critical role of enhanced mitochondrial ROS release in 3,3'-diindolylmethane-induced p21 up-regulation in human breast cancer cells.

  12. The mammalian mid-pachytene checkpoint: meiotic arrest in spermatocytes with a mutation in Atm alone or in combination with a Trp53 (p53) or Cdkn1a (p21/cip1) mutation

    NARCIS (Netherlands)

    Ashley, T.; Westphal, C.; Plug-de Maggio, A.; de rooij, D. G.

    2004-01-01

    ATM, the protein product of the gene mutated in the human autosomal recessive disorder ataxia telangiectasia, is involved in detection of double strand breaks (DSBs) and is a key component of the damage surveillance network of cell cycle proteins. In somatic cells ATM phosphorylates many other

  13. Caffeic acid phenethyl ester induced cell cycle arrest and growth inhibition in androgen-independent prostate cancer cells via regulation of Skp2, p53, p21Cip1 and p27Kip1

    OpenAIRE

    Lin, Hui-Ping; Lin, Ching-Yu; Huo, Chieh; Hsiao, Ping-Hsuan; Su, Liang-Cheng; Jiang, Shih Sheng; Chan, Tzu-Min; Chang, Chung-Ho; Chen, Li-Tzong; Kung, Hsing-Jien; Wang, Horng-Dar; Chuu, Chih-Pin

    2015-01-01

    Prostate cancer (PCa) patients receiving the androgen ablation therapy ultimately develop recurrent castration-resistant prostate cancer (CRPC) within 1?3 years. Treatment with caffeic acid phenethyl ester (CAPE) suppressed cell survival and proliferation via induction of G1 or G2/M cell cycle arrest in LNCaP 104-R1, DU-145, 22Rv1, and C4?2 CRPC cells. CAPE treatment also inhibited soft agar colony formation and retarded nude mice xenograft growth of LNCaP 104-R1 cells. We identified that CAP...

  14. A phthalide derivative isolated from endophytic fungi Pestalotiopsis photiniae induces G1 cell cycle arrest and apoptosis in human HeLa cells

    International Nuclear Information System (INIS)

    Chen, C.; Yang, R.L.

    2013-01-01

    MP [4-(3′,3′-dimethylallyloxy)-5-methyl-6-methoxyphthalide] was obtained from liquid culture of Pestalotiopsis photiniae isolated from the Chinese Podocarpaceae plant Podocarpus macrophyllus. MP significantly inhibited the proliferation of HeLa tumor cell lines. After treatment with MP, characteristic apoptotic features such as DNA fragmentation and chromatin condensation were observed in DAPI-stained HeLa cells. Flow cytometry showed that MP induced G1 cell cycle arrest and apoptosis in a dose-dependent manner. Western blotting and real-time reverse transcription-polymerase chain reaction were used to investigate protein and mRNA expression. MP caused significant cell cycle arrest by upregulating the cyclin-dependent kinase inhibitor p27 KIP1 protein and p21 CIP1 mRNA levels in HeLa cells. The expression of p73 protein was increased after treatment with various MP concentrations. mRNA expression of the cell cycle-related genes, p21 CIP1 , p16 INK4a and Gadd45α, was significantly upregulated and mRNA levels demonstrated significantly increased translation of p73, JunB, FKHR, and Bim. The results indicate that MP may be a potential treatment for cervical cancer

  15. The role of hypoxia inducible factor-1 alpha in bypassing oncogene-induced senescence.

    Directory of Open Access Journals (Sweden)

    Mehtap Kilic Eren

    Full Text Available Oncogene induced senescence (OIS is a sustained anti-proliferative response acutely induced in primary cells via activation of mitogenic oncogenes such as Ras/BRAF. This mechanism acts as an initial barrier preventing normal cells transformation into malignant cell. Besides oncogenic activation and DNA damage response (DDR, senescence is modulated by a plethora of other factors, and one of the most important one is oxygen tension of the tissue. The aim of this study was to determine the impact of hypoxia on RasV12-induced senescence in human diploid fibroblasts (HDFs. We showed here that hypoxia prevents execution of oncogene induced senescence (OIS, through a strong down-regulation of senescence hallmarks, such as SA- β-galactosidase, H3K9me3, HP1γ, p53, p21CIP1 and p16INK4a in association with induction of hypoxia inducible factor-1α (HIF-1α. In addition, hypoxia also decreased marks of H-RasV12-induced DDR in both cell lines through down-regulation of ATM/ATR, Chk1 and Chk2 phosphorylation as well as decreased γ-H2AX positivity. Utilizing shRNA system targeting HIF-1α we show that HIF-1α is directly involved in down regulation of p53 and its target p21CIP1 but not p16INK4a. In line with this finding we found that knock down of HIF-1α leads to a strong induction of apoptotic response, but not restoration of senescence in Ras expressing HDFs in hypoxia. This indicates that HIF-1α is an important player in early steps of tumorigenesis, leading to suppression of senescence through its negative regulation of p53 and p21CIP1. In our work we describe a mechanism through which hypoxia and specifically HIF-1α preclude cells from maintaining senescence-driven anti proliferative response. These findings indicate the possible mechanism through which hypoxic environment helps premalignant cells to evade impingement of cellular failsafe pathways.

  16. CDK2 phosphorylation of Smad2 disrupts TGF-beta transcriptional regulation in resistant primary bone marrow myeloma cells.

    Science.gov (United States)

    Baughn, Linda B; Di Liberto, Maurizio; Niesvizky, Ruben; Cho, Hearn J; Jayabalan, David; Lane, Joseph; Liu, Fang; Chen-Kiang, Selina

    2009-02-15

    Resistance to growth suppression by TGF-beta1 is common in cancer; however, mutations in this pathway are rare in hematopoietic malignancies. In multiple myeloma, a fatal cancer of plasma cells, malignant cells accumulate in the TGF-beta-rich bone marrow due to loss of both cell cycle and apoptotic controls. Herein we show that TGF-beta activates Smad2 but fails to induce cell cycle arrest or apoptosis in primary bone marrow myeloma and human myeloma cell lines due to its inability to activate G(1) cyclin-dependent kinase (CDK) inhibitors (p15(INK4b), p21(CIP1/WAF1), p27(KIP1), p57(KIP2)) or to repress c-myc and Bcl-2 transcription. Correlating with aberrant activation of CDKs, CDK-dependent phosphorylation of Smad2 on Thr(8) (pT8), a modification linked to impaired Smad activity, is elevated in primary bone marrow myeloma cells, even in asymptomatic monoclonal gammopathy of undetermined significance. Moreover, CDK2 is the predominant CDK that phosphorylates Smad2 on T8 in myeloma cells, leading to inhibition of Smad2-Smad4 association that precludes transcriptional regulation by Smad2. Our findings provide the first direct evidence that pT8 Smad2 couples dysregulation of CDK2 to TGF-beta resistance in primary cancer cells, and they suggest that disruption of Smad2 function by CDK2 phosphorylation acts as a mechanism for TGF-beta resistance in multiple myeloma.

  17. TGF-beta3 is expressed in taste buds and inhibits proliferation of primary cultured taste epithelial cells.

    Science.gov (United States)

    Nakamura, Shin-ichi; Kawai, Takayuki; Kamakura, Takashi; Ookura, Tetsuya

    2010-01-01

    Transforming growth factor-betas (TGF-betas), expressed in various tissues, play important roles in embryonic development and adult tissue homeostasis through their effects on cell proliferation, cell differentiation, cell death, and cell motility. However, expression of TGF-beta signaling components and their biological effect on taste epithelia has not been elucidated. We performed expression analysis of TGF-beta signaling components in taste epithelia and found that the TGF-beta3 mRNA was specifically expressed in taste buds. Type II TGF-betas receptor (TbetaR-II) mRNA was specifically expressed in the tongue epithelia including the taste epithelia. To elucidate the biological function of TGF-beta3 in taste epithelia, we performed proliferation assay with primary cultured taste epithelial cells. In the presence of TGF-beta3, percentage of BrdU-labeled cells decreased significantly, suggesting that the TGF-beta3 inhibited the proliferation of cultured taste epithelial cells through inhibiting cell-cycle entry into S phase. By quantitative reverse transcription-polymerase chain reaction assay, we found that the TGF-beta3 resulted in an increased level of expression of p15Ink4b and p21Cip1, suggesting that the TGF-beta3 inhibited the taste epithelial cell proliferation through inhibiting G1cyclin-Cdk complexes. Taken together, these results suggested that the TGF-beta3 may regulate taste epithelial cell homeostasis through controlling cell proliferation.

  18. Establishment of ultra long-lived cell lines by transfection of TERT into normal human fibroblast TIG-1 and their characterization.

    Science.gov (United States)

    Kamada, Mizuna; Kumazaki, Tsutomu; Matsuo, Taira; Mitsui, Youji; Takahashi, Tomoko

    2012-06-01

    To establish useful human normal cell lines, TERT (telomerase reverse transcriptase) cDNA was transfected into normal female lung fibroblast, TIG-1. After long-term-sub-cultivation of 74 individual clones selected for resistance to G418, we obtained 55 cultures with normal range of life span [75 PDL (population doubling level)], 16 cultures with extended life span (75-140 PDL). In addition, 3 immortal cell strains and unexpectedly, one ultra long-lived cell line (ULT-1) with life span of 166 PDL were established. IMT-1, one of the immortal cell strains was confirmed to maintain long telomere length, high telomerase activity and an extremely low level of p16INK4A. They also showed moderate p53 and p21CIP1 expression, keeping vigorous growth rate even at 450 PDL. High level of fibronectin and collagen 1α expression confirmed IMT-1 as normal fibroblasts, although one X chromosome had been lost. ULT-1, however, kept a near normal karyotypes and had shortening of telomere length, high expression of p16INK4A, moderate levels of senescence associated-β-galactosidase positive cells and decreased growth rate only after 150 PDs (population doublings), and finally reached senescence at 166 PDL with morphology of normal senescent fibroblasts. As resources of standard normal human cell, abundant vials of early and middle passages of ULT-1 have been stocked. The use of the cell line is discussed, focusing on isograft of artificial skin and screening of anti-aging or safe chemical agents.

  19. Resveratrol Induced Premature Senescence Is Associated with DNA Damage Mediated SIRT1 and SIRT2 Down-Regulation.

    Directory of Open Access Journals (Sweden)

    Mehtap Kilic Eren

    Full Text Available The natural polyphenolic compound resveratrol (3,4,5-trihydroxy-trans-stilbene has broad spectrum health beneficial activities including antioxidant, anti-inflammatory, anti-aging, anti-cancer, cardioprotective, and neuroprotective effects. Remarkably, resveratrol also induces apoptosis and cellular senescence in primary and cancer cells. Resveratrol's anti-aging effects both in vitro and in vivo attributed to activation of a (NAD-dependent histone deacetylase family member sirtuin-1 (SIRT1 protein. In mammals seven members (SIRT1-7 of sirtuin family have been identified. Among those, SIRT1 is the most extensively studied with perceptive effects on mammalian physiology and suppression of the diseases of aging. Yet no data has specified the role of sirtuins, under conditions where resveratrol treatment induces senescence. Current study was undertaken to investigate the effects of resveratrol in human primary dermal fibroblasts (BJ and to clarify the role of sirtuin family members in particular SIRT1 and SIRT2 that are known to be involved in cellular stress responses and cell cycle, respectively. Here, we show that resveratrol decreases proliferation of BJ cells in a time and dose dependent manner. In addition the increase in senescence associated β-galactosidase (SA-β-gal activity and methylated H3K9-me indicate the induction of premature senescence. A significant increase in phosphorylation of γ-H2AX, a surrogate of DNA double strand breaks, as well as in levels of p53, p21CIP1 and p16INK4A is also detected. Interestingly, at concentrations where resveratrol induced premature senescence we show a significant decrease in SIRT1 and SIRT2 levels by Western Blot and quantitative RT-PCR analysis. Conversely inhibition of SIRT1 and SIRT2 via siRNA or sirtinol treatment also induced senescence in BJ fibroblasts associated with increased SA-β-gal activity, γ-H2AX phosphorylation and p53, p21CIP1 and p16INK4A levels. Interestingly DNA damaging

  20. Protective Effect of Ginsenoside Rg1 on Hematopoietic Stem/Progenitor Cells through Attenuating Oxidative Stress and the Wnt/β-Catenin Signaling Pathway in a Mouse Model of d-Galactose-induced Aging.

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    Li, Jing; Cai, Dachuan; Yao, Xin; Zhang, Yanyan; Chen, Linbo; Jing, Pengwei; Wang, Lu; Wang, Yaping

    2016-06-09

    Stem cell senescence is an important and current hypothesis accounting for organismal aging, especially the hematopoietic stem cell (HSC). Ginsenoside Rg1 is the main active pharmaceutical ingredient of ginseng, which is a traditional Chinese medicine. This study explored the protective effect of ginsenoside Rg1 on Sca-1⁺ hematopoietic stem/progenitor cells (HSC/HPCs) in a mouse model of d-galactose-induced aging. The mimetic aging mouse model was induced by continuous injection of d-gal for 42 days, and the C57BL/6 mice were respectively treated with ginsenoside Rg1, Vitamin E or normal saline after 7 days of d-gal injection. Compared with those in the d-gal administration alone group, ginsenoside Rg1 protected Sca-1⁺ HSC/HPCs by decreasing SA-β-Gal and enhancing the colony forming unit-mixture (CFU-Mix), and adjusting oxidative stress indices like reactive oxygen species (ROS), total anti-oxidant (T-AOC), superoxide dismutase (SOD), glutathione peroxidase (GSH-px) and malondialdehyde (MDA). In addition, ginsenoside Rg1 decreased β-catenin and c-Myc mRNA expression and enhanced the phosphorylation of GSK-3β. Moreover, ginsenoside Rg1 down-regulated advanced glycation end products (AGEs), 4-hydroxynonenal (4-HNE), phospho-histone H2A.X (r-H2A.X), 8-OHdG, p16(Ink4a), Rb, p21(Cip1/Waf1) and p53 in senescent Sca-1⁺ HSC/HPCs. Our findings indicated that ginsenoside Rg1 can improve the resistance of Sca-1⁺ HSC/HPCs in a mouse model of d-galactose-induced aging through the suppression of oxidative stress and excessive activation of the Wnt/β-catenin signaling pathway, and reduction of DNA damage response, p16(Ink4a)-Rb and p53-p21(Cip1/Waf1) signaling.

  1. The nuclear receptor NR2E1/TLX controls senescence

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    Krusche, Benjamin; Pemberton, Helen; Alonso, Marta M.; Chandler, Hollie; Brookes, Sharon; Parrinello, Simona; Peters, Gordon; Gil, Jesús

    2014-01-01

    The nuclear receptor NR2E1 (also known as TLX or tailless) controls the self-renewal of neural stem cells (NSCs) and has been implied as an oncogene which initiates brain tumours including glioblastomas. Despite NR2E1 regulating targets like p21CIP1 or PTEN we still lack a full explanation for its role in NSC self-renewal and tumorigenesis. We know that Polycomb repressive complexes (PRC) also control stem cell self-renewal and tumorigenesis, but so far, no formal connection has been established between NR2E1 and PRCs. In a screen for transcription factors regulating the expression of the Polycomb protein CBX7, we identified NR2E1 as one of its more prominent regulators. NR2E1 binds at the CBX7 promoter, inducing its expression. Notably CBX7 represses NR2E1 as part of a regulatory loop. Ectopic NR2E1 expression inhibits cellular senescence, extending cellular lifespan in fibroblasts via CBX7-mediated regulation of p16INK4a and direct repression of p21CIP1. In addition NR2E1 expression also counteracts oncogene-induced senescence (OIS). The importance of NR2E1 to restrain senescence is highlighted through the process of knocking down its expression, which causes premature senescence in human fibroblasts and epithelial cells. We also confirmed that NR2E1 regulates CBX7 and restrains senescence in NSCs. Finally, we observed that the expression of NR2E1 directly correlates with that of CBX7 in human glioblastoma multiforme. Overall we identified control of senescence and regulation of Polycomb action as two possible mechanisms that can join those so far invoked to explain the role of NR2E1 in control of NSC self-renewal and cancer. PMID:25328137

  2. The nuclear receptor NR2E1/TLX controls senescence.

    Science.gov (United States)

    O'Loghlen, Ana; Martin, Nadine; Krusche, Benjamin; Pemberton, Helen; Alonso, Marta M; Chandler, Hollie; Brookes, Sharon; Parrinello, Simona; Peters, Gordon; Gil, Jesús

    2015-07-30

    The nuclear receptor NR2E1 (also known as TLX or tailless) controls the self-renewal of neural stem cells (NSCs) and has been implied as an oncogene which initiates brain tumors including glioblastomas. Despite NR2E1 regulating targets like p21(CIP1) or PTEN we still lack a full explanation for its role in NSC self-renewal and tumorigenesis. We know that polycomb repressive complexes also control stem cell self-renewal and tumorigenesis, but so far, no formal connection has been established between NR2E1 and PRCs. In a screen for transcription factors regulating the expression of the polycomb protein CBX7, we identified NR2E1 as one of its more prominent regulators. NR2E1 binds at the CBX7 promoter, inducing its expression. Notably CBX7 represses NR2E1 as part of a regulatory loop. Ectopic NR2E1 expression inhibits cellular senescence, extending cellular lifespan in fibroblasts via CBX7-mediated regulation of p16(INK4a) and direct repression of p21(CIP1). In addition NR2E1 expression also counteracts oncogene-induced senescence. The importance of NR2E1 to restrain senescence is highlighted through the process of knocking down its expression, which causes premature senescence in human fibroblasts and epithelial cells. We also confirmed that NR2E1 regulates CBX7 and restrains senescence in NSCs. Finally, we observed that the expression of NR2E1 directly correlates with that of CBX7 in human glioblastoma multiforme. Overall we identified control of senescence and regulation of polycomb action as two possible mechanisms that can join those so far invoked to explain the role of NR2E1 in control of NSC self-renewal and cancer.

  3. INK4 proteins, a family of mammalian CDK inhibitors with novel biological functions.

    Science.gov (United States)

    Cánepa, Eduardo T; Scassa, María E; Ceruti, Julieta M; Marazita, Mariela C; Carcagno, Abel L; Sirkin, Pablo F; Ogara, María F

    2007-07-01

    The cyclin D-Cdk4-6/INK4/Rb/E2F pathway plays a key role in controlling cell growth by integrating multiple mitogenic and antimitogenic stimuli. The members of INK4 family, comprising p16(INK4a), p15(INK4b), p18(INK4c), and p19(INK4d), block the progression of the cell cycle by binding to either Cdk4 or Cdk6 and inhibiting the action of cyclin D. These INK4 proteins share a similar structure dominated by several ankyrin repeats. Although they appear to be structurally redundant and equally potent as inhibitors, the INK4 family members are differentially expressed during mouse development. The striking diversity in the pattern of expression of INK4 genes suggested that this family of cell cycle inhibitors might have cell lineage-specific or tissue-specific functions. The INK4 proteins are commonly lost or inactivated by mutations in diverse types of cancer, and they represent established or candidate tumor suppressors. Apart from their capacity to arrest cells in the G1-phase of the cell cycle they have been shown to participate in an increasing number of cellular processes. Given their emerging roles in fundamental physiological as well as pathological processes, it is interesting to explore the diverse roles for the individual INK4 family members in different functions other than cell cycle regulation. Extensive studies, over the past few years, uncover the involvement of INK4 proteins in senescence, apoptosis, DNA repair, and multistep oncogenesis. We will focus the discussion here on these unexpected issues.

  4. Prolonged mechanical ventilation induces cell cycle arrest in newborn rat lung.

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    Andreas A Kroon

    Full Text Available RATIONALE: The molecular mechanism(s by which mechanical ventilation disrupts alveolar development, a hallmark of bronchopulmonary dysplasia, is unknown. OBJECTIVE: To determine the effect of 24 h of mechanical ventilation on lung cell cycle regulators, cell proliferation and alveolar formation in newborn rats. METHODS: Seven-day old rats were ventilated with room air for 8, 12 and 24 h using relatively moderate tidal volumes (8.5 mL.kg⁻¹. MEASUREMENT AND MAIN RESULTS: Ventilation for 24 h (h decreased the number of elastin-positive secondary crests and increased the mean linear intercept, indicating arrest of alveolar development. Proliferation (assessed by BrdU incorporation was halved after 12 h of ventilation and completely arrested after 24 h. Cyclin D1 and E1 mRNA and protein levels were decreased after 8-24 h of ventilation, while that of p27(Kip1 was significantly increased. Mechanical ventilation for 24 h also increased levels of p57(Kip2, decreased that of p16(INK4a, while the levels of p21(Waf/Cip1 and p15(INK4b were unchanged. Increased p27(Kip1 expression coincided with reduced phosphorylation of p27(Kip1 at Thr¹⁵⁷, Thr¹⁸⁷ and Thr¹⁹⁸ (p<0.05, thereby promoting its nuclear localization. Similar -but more rapid- changes in cell cycle regulators were noted when 7-day rats were ventilated with high tidal volume (40 mL.kg⁻¹ and when fetal lung epithelial cells were subjected to a continuous (17% elongation cyclic stretch. CONCLUSION: This is the first demonstration that prolonged (24 h of mechanical ventilation causes cell cycle arrest in newborn rat lungs; the arrest occurs in G₁ and is caused by increased expression and nuclear localization of Cdk inhibitor proteins (p27(Kip1, p57(Kip2 from the Kip family.

  5. Long Term Exposure to Polyphenols of Artichoke (Cynara scolymus L.) Exerts Induction of Senescence Driven Growth Arrest in the MDA-MB231 Human Breast Cancer Cell Line.

    Science.gov (United States)

    Mileo, Anna Maria; Di Venere, Donato; Abbruzzese, Claudia; Miccadei, Stefania

    2015-01-01

    Polyphenolic extracts from the edible part of artichoke (Cynara scolymus L.) have been shown to be potential chemopreventive and anticancer dietary compounds. High doses of polyphenolic extracts (AEs) induce apoptosis and decrease the invasive potential of the human breast cancer cell line, MDA-MB231. However, the molecular mechanism underlying AEs antiproliferative effects is not completely understood. We demonstrate that chronic and low doses of AEs treatment at sublethal concentrations suppress human breast cancer cell growth via a caspases-independent mechanism. Furthermore, AEs exposure induces a significant increase of senescence-associated β-galactosidase (SA-β-gal) staining and upregulation of tumour suppressor genes, p16(INK4a) and p21(Cip1/Waf1) in MDA-MB231 cells. AEs treatment leads to epigenetic alterations in cancer cells, modulating DNA hypomethylation and lysine acetylation levels in total proteins. Cell growth arrest correlates with increased reactive oxygen species (ROS) production in AEs treated breast cancer cells. Inhibition of ROS generation by N-acetylcysteine (NAC) attenuates the antiproliferative effect. These findings demonstrate that chronic AEs treatment inhibits breast cancer cell growth via the induction of premature senescence through epigenetic and ROS-mediated mechanisms. Our results suggest that artichoke polyphenols could be a promising dietary tool either in cancer chemoprevention or/and in cancer treatment as a nonconventional, adjuvant therapy.

  6. Molecular Mechanisms Underlying Hepatocellular Carcinoma

    Directory of Open Access Journals (Sweden)

    Christian Trepo

    2009-11-01

    Full Text Available Hepatocarcinogenesis is a complex process that remains still partly understood. That might be explained by the multiplicity of etiologic factors, the genetic/epigenetic heterogeneity of tumors bulks and the ignorance of the liver cell types that give rise to tumorigenic cells that have stem cell-like properties. The DNA stress induced by hepatocyte turnover, inflammation and maybe early oncogenic pathway activation and sometimes viral factors, leads to DNA damage response which activates the key tumor suppressive checkpoints p53/p21Cip1 and p16INK4a/pRb responsible of cell cycle arrest and cellular senescence as reflected by the cirrhosis stage. Still obscure mechanisms, but maybe involving the Wnt signaling and Twist proteins, would allow pre-senescent hepatocytes to bypass senescence, acquire immortality by telomerase reactivation and get the last genetic/epigenetic hits necessary for cancerous transformation. Among some of the oncogenic pathways that might play key driving roles in hepatocarcinogenesis, c-myc and the Wnt/β-catenin signaling seem of particular interest. Finally, antiproliferative and apoptosis deficiencies involving TGF-β, Akt/PTEN, IGF2 pathways for instance are prerequisite for cancerous transformation. Of evidence, not only the transformed liver cell per se but the facilitating microenvironment is of fundamental importance for tumor bulk growth and metastasis.

  7. Dickkopf-3 maintains the PANC-1 human pancreatic tumor cells in a dedifferentiated state.

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    Zenzmaier, Christoph; Hermann, Martin; Hengster, Paul; Berger, Peter

    2012-01-01

    Pancreatic cancer (PaCa) is the fourth leading cause of cancer deaths in Western societies, with pancreatic ductal adenocarcinomas (PDACs) accounting for >90% of such cases. PDAC is a heterogeneous disease that includes a subset showing overexpression of the secreted glycoprotein Dickkopf-related protein 3 (Dkk-3), a protein shown to be downregulated in various cancers of different tissues. The biological function of Dkk-3 in this subset was studied using the Dkk-3 expressing PANC-1 cell line as a model for PDACs. The influence of Dkk-3 overexpression and knockdown on cellular differentiation and proliferation of PANC-1 was investigated. Confocal microscopy showed that Dkk-3 was expressed in a fraction of PANC-1 cells. While lentiviral-mediated overexpression of DKK3 did not alter cellular proliferation, knockdown of DKK3 resulted in significant reduction of cellular proliferation and concomitant induction of cell cycle inhibitors CDKN2B (p15INK4b), CDKN1A (p21CIP1) and CDKN1B (p27KIP1). In parallel, pancreatic epithelial cell differentiation markers AMY2A, CELA1, CTRB1, GCG, GLB1 and INS were significantly upregulated. PANC-1 cells differentiated using exendin-4 showed analogous induction of cell cycle inhibitors and differentiation markers. Thus, we conclude that Dkk-3 is required to maintain a highly dedifferentiated and consequently proliferative state in PANC-1, indicating a similar function in the Dkk-3 overexpressing subset of PDACs. Therefore, Dkk-3 represents a potential target for the treatment of Dkk-3-positive subtypes of PaCa to drive cells into cell cycle arrest and differentiation.

  8. Silencing of reversion-inducing cysteine-rich protein with Kazal motifs stimulates hyperplastic phenotypes through activation of epidermal growth factor receptor and hypoxia-inducible factor-2α.

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    You Mie Lee

    Full Text Available Reversion-inducing cysteine-rich protein with Kazal motifs (RECK, a tumor suppressor is down-regulated by the oncogenic signals and hypoxia, but the biological function of RECK in early tumorigenic hyperplastic phenotypes is largely unknown. Knockdown of RECK by small interfering RNA (siRECK or hypoxia significantly promoted cell proliferation in various normal epithelial cells. Hypoxia as well as knockdown of RECK by siRNA increased the cell cycle progression, the levels of cyclin D1 and c-Myc, and the phosphorylation of Rb protein (p-pRb, but decreased the expression of p21(cip1, p27(kip1, and p16(ink4A. HIF-2α was upregulated by knockdown of RECK, indicating HIF-2α is a downstream target of RECK. As knockdown of RECK induced the activation of epidermal growth factor receptor (EGFR and treatment of an EGFR kinase inhibitor, gefitinib, suppressed HIF-2α expression induced by the silencing of RECK, we can suggest that the RECK silenicng-EGFR-HIF-2α axis might be a key molecular mechanism to induce hyperplastic phenotype of epithelial cells. It was also found that shRNA of RECK induced larger and more numerous colonies than control cells in an anchorage-independent colony formation assay. Using a xenograft assay, epithelial cells with stably transfected with shRNA of RECK formed a solid mass earlier and larger than those with control cells in nude mice. In conclusion, the suppression of RECK may promote the development of early tumorigenic hyperplastic characteristics in hypoxic stress.

  9. The anti-inflammatory effect of melatonin in SH-SY5Y neuroblastoma cells exposed to sublethal dose of hydrogen peroxide.

    Science.gov (United States)

    Nopparat, Chutikorn; Chantadul, Varunya; Permpoonputtana, Kannika; Govitrapong, Piyarat

    2017-06-01

    Brain inflammaging is considered as one of the underlying factors of neurodegenerative diseases. The present study aimed to investigate the effects of melatonin, an endogenous indoleamine mainly synthesized by the pineal gland, on hydrogen peroxide (H 2 O 2 )-induced inflammaging state in SH-SY5Y cells. Our data showed that p21 Cip1 and p16 INK4a , cell cycle arrest markers, and the number of senescence-associated β-galactosidase (SA-βgal) staining increased significantly in H 2 O 2 -treated cells. Melatonin treatment could reverse this effect. Flow cytometry analysis showed a significantly higher percentage in the G0/G1 phase and a lower proportion in the S phase of H 2 O 2 treated cells. Cells pretreated with H 2 O 2 showed a dramatic decrease in the formation of Ki67 immunoactivity while the treatment with melatonin increased Ki67-positive cell. Both mRNA and protein expression levels of the pro-inflammatory cytokines, interleukin-1β (IL-1β), IL-6 and, tumor necrosis factor-α (TNF-α) which were increased after induction with H 2 O 2 , could be attenuated by melatonin. In addition, melatonin decreased the phospho-nuclear factor kappa B (pNF-κB) expression and prevented its nuclear translocation, as well as abrogated the reduction of nuclear factor erythroid 2-related factor 2 (Nrf2) in SH-SY5Y cells exposed to H 2 O 2 . The present data suggested the importance of melatonin on ameliorating inflammation in SH-SY5Y cells. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Angelica Sinensis Polysaccharide Prevents Hematopoietic Stem Cells Senescence in D-Galactose-Induced Aging Mouse Model

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    Xinyi Mu

    2017-01-01

    Full Text Available Age-related regression in hematopoietic stem/progenitor cells (HSC/HPCs limits replenishment of the blood and immune system and hence contributes to hematopoietic diseases and declined immunity. In this study, we employed D-gal-induced aging mouse model and observed the antiaging effects of Angelica Sinensis Polysaccharide (ASP, a major active ingredient in dong quai (Chinese Angelica Sinensis, on the Sca-1+ HSC/HPCs in vivo. ASP treatment prevents HSC/HPCs senescence with decreased AGEs levels in the serum, reduced SA-β-Gal positive cells, and promoted CFU-Mix formation in the D-gal administrated mouse. We further found that multiple mechanisms were involved: (1 ASP treatment prevented oxidative damage as total antioxidant capacity was increased and levels of reactive oxygen species (ROS, 8-OHdG, and 4-HNE were declined, (2 ASP reduced the expression of γ-H2A.X which is a DNA double strand breaks (DSBs marker and decreased the subsequent ectopic expressions of effectors in p16Ink4a-RB and p19Arf-p21Cip1/Waf senescent pathways, and (3 ASP inhibited the excessive activation of Wnt/β-catenin signaling in aged HSC/HPCs, as the expressions of β-catenin, phospho-GSK-3β, and TCF-4 were decreased, and the cyto-nuclear translocation of β-catenin was inhibited. Moreover, compared with the positive control of Vitamin E, ASP exhibited a better antiaging effect and a weaker antioxidation ability, suggesting a novel protective role of ASP in the hematopoietic system.

  11. Microsatellite alteration and immunohistochemical expression profile of chromosome 9p21 in patients with sporadic renal cell carcinoma following surgical resection

    International Nuclear Information System (INIS)

    El-Mokadem, Ismail; Lim, Alison; Kidd, Thomas; Garret, Katherine; Pratt, Norman; Batty, David; Fleming, Stewart; Nabi, Ghulam

    2016-01-01

    Long-term prognostic significance of loss of heterozygosity on chromosome 9p21 for localized renal cell carcinoma following surgery remains unreported. The study assessed the frequency of deletions of different loci of chromosome 9p along with immunohistochemical profile of proteins in surgically resected renal cancer tissue and correlated this with long-term outcomes. DNA was extracted from renal tumours and corresponding normal kidney tissues in prospectively collected samples of 108 patients who underwent surgical resection for clinically localized disease between January 2001 and December 2005, providing a minimum of 9 years follow-up for each participant. After checking quality of DNA, amplified by PCR, loss of heterozygosity (LOH) on chromosome 9p was assessed using 6 microsatellite markers in 77 clear cell carcinoma. Only 5 of the markers showed LOH (D9S1814, D9S916, D9S974, D9S942, and D9S171). Protein expression of p15(INK4b), p16(INK4a), p14(ARF), CAIX, and adipose related protein (ADFP) were demonstrated by immunostaining in normal and cancer tissues. Loss of heterozygosity for microsatellite analysis was correlated with tumour characteristics, recurrence free, cancer specific, and overall survival, including significance of immunohistochemical profile of protein expressions. The main deletion was found at loci telomeric to CDKN2A region at D9S916. There was a significant correlation between frequency of LOH stage (p = 0.005) and metastases (p = 0.006) suggesting a higher LOH for advanced and aggressive renal cell carcinoma. Most commonly observed LOH in the 3 markers: D9S916, D9S974, and D9S942 were associated with poor survival, and were statistically significant on multivariate analysis. Immunohistochemical expression of p14, p15, and p16 proteins were either low or absent in cancer tissue compared to normal. Loss of heterozygosity of p921 chromosome is associated with aggressive tumours, and predicts cancer specific or recurrence free survival on

  12. Methylation profiles of thirty four promoter-CpG islands and concordant methylation behaviours of sixteen genes that may contribute to carcinogenesis of astrocytoma

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    Wang Yifei

    2004-09-01

    Full Text Available Abstract Background Astrocytoma is a common aggressive intracranial tumor and presents a formidable challenge in the clinic. Association of altered DNA methylation patterns of the promoter CpG islands with the expression profile of cancer-related genes, has been found in many human tumors. Therefore, DNA methylation status as such may serve as an epigenetic biomarker for both diagnosis and prognosis of human tumors, including astrocytoma. Methods We used the methylation specific PCR in conjunction with sequencing verification to establish the methylation profile of the promoter CpG island of thirty four genes in astrocytoma tissues from fifty three patients (The WHO grading:. I: 14, II: 15, III: 12 and IV: 12 cases, respectively. In addition, compatible tissues (normal tissues distant from lesion from three non-astrocytoma patients were included as the control. Results Seventeen genes (ABL, APC, APAF1, BRCA1, CSPG2, DAPK1, hMLH1, LKB1, PTEN, p14ARF, p15INK4b, p27KIP1, p57KIP2, RASSF1C, RB1, SURVIVIN, and VHL displayed a uniformly unmethylated pattern in all the astrocytoma and non-astrocytoma tissues examined. However, the MAGEA1 gene that was inactivated and hypermethylated in non-astrocytoma tissues, was partially demethylated in 24.5% of the astrocytoma tissues (co-existence of the hypermethylated and demethylated alleles. Of the astrocytoma associated hypermethylated genes, the methylation pattern of the CDH13, cyclin a1, DBCCR1, EPO, MYOD1, and p16INK4a genes changed in no more than 5.66% (3/53 of astrocytoma tissues compared to non-astrocytoma controls, while the RASSF1A, p73, AR, MGMT, CDH1, OCT6,, MT1A, WT1, and IRF7 genes were more frequently hypermethylated in 69.8%, 47.2%, 41.5%, 35.8%, 32%, 30.2%, 30.2%, 30.2% and 26.4% of astrocytoma tissues, respectively. Demethylation mediated inducible expression of the CDH13, MAGEA1, MGMT, p73 and RASSF1A genes was established in an astrocytoma cell line (U251, demonstrating that expression of

  13. Intrinsic radiation resistance in human chondrosarcoma cells

    International Nuclear Information System (INIS)

    Moussavi-Harami, Farid; Mollano, Anthony; Martin, James A.; Ayoob, Andrew; Domann, Frederick E.; Gitelis, Steven; Buckwalter, Joseph A.

    2006-01-01

    Human chondrosarcomas rarely respond to radiation treatment, limiting the options for eradication of these tumors. The basis of radiation resistance in chondrosarcomas remains obscure. In normal cells radiation induces DNA damage that leads to growth arrest or death. However, cells that lack cell cycle control mechanisms needed for these responses show intrinsic radiation resistance. In previous work, we identified immortalized human chondrosarcoma cell lines that lacked p16 ink4a , one of the major tumor suppressor proteins that regulate the cell cycle. We hypothesized that the absence of p16 ink4a contributes to the intrinsic radiation resistance of chondrosarcomas and that restoring p16 ink4a expression would increase their radiation sensitivity. To test this we determined the effects of ectopic p16 ink4a expression on chondrosarcoma cell resistance to low-dose γ-irradiation (1-5 Gy). p16 ink4a expression significantly increased radiation sensitivity in clonogenic assays. Apoptosis did not increase significantly with radiation and was unaffected by p16 ink4a transduction of chondrosarcoma cells, indicating that mitotic catastrophe, rather than programmed cell death, was the predominant radiation effect. These results support the hypothesis that p16 ink4a plays a role in the radiation resistance of chondrosarcoma cell lines and suggests that restoring p16 expression will improve the radiation sensitivity of human chondrosarcomas

  14. The overexpression of p16 is not a surrogate marker for high-risk human papilloma virus genotypes and predicts clinical outcomes for vulvar cancer.

    Science.gov (United States)

    Sznurkowski, Jacek J; Żawrocki, Anton; Biernat, Wojciech

    2016-07-13

    We aimed to evaluate the correlation between p16(ink4a)-overexpression and high risk (hr)HPV-DNA in vulvar squamous cell carcinoma (vSCC) tumors as well as the impact of both biomarkers on the prognosis of vSCC patients. PCR-detection of (hr)HPV-DNA and immunohistochemical staining for p16(ink4a) were conducted in 85 vSCC tumors. Survival analyses included the Kaplan-Meier method, log-rank test and Cox proportional hazards model. p16(ink4a)-overexpression and (hr)HPV-DNA were detected in 35 and 37 of the 85 tumors, respectively. Among the 35 p16(ink4a)-positive tumors, 10 lacked (hr)HPV-DNA (29 %). Among the 50 p16(ink4a)-negative tumors, (hr)HPV-DNA was detected in 12 cases (24 %). The median follow-up was 89.20 months (range 1.7-189.5 months). P16(ink4a)-overexpression, but not (hr)HPV-DNA positivity of the primary tumor, was correlated with prolonged overall survival (OS) (p = 0.009). P16(ink4a)-overexpression predicted a better response to radiotherapy (p overexpression (p = 0.022), and adjuvant RTX (p overexpression (HR 1-2.11, 95 % CI 1.13-3.95, p = 0.001) are independent prognostic factors. The discovered overlap suggests the use of p16(ink4a) in combination with HPV-DNA detection as an ancillary test for future research and clinical studies in vSCC. The prognostic and predictive value of p16(ink4a)-overexpression should be tested in larger cohort studies.

  15. The overexpression of p16 is not a surrogate marker for high-risk human papilloma virus genotypes and predicts clinical outcomes for vulvar cancer

    International Nuclear Information System (INIS)

    Sznurkowski, Jacek J.; Żawrocki, Anton; Biernat, Wojciech

    2016-01-01

    We aimed to evaluate the correlation between p16 ink4a -overexpression and high risk (hr)HPV-DNA in vulvar squamous cell carcinoma (vSCC) tumors as well as the impact of both biomarkers on the prognosis of vSCC patients. PCR-detection of (hr)HPV-DNA and immunohistochemical staining for p16 ink4a were conducted in 85 vSCC tumors. Survival analyses included the Kaplan–Meier method, log-rank test and Cox proportional hazards model. p16 ink4a -overexpression and (hr)HPV-DNA were detected in 35 and 37 of the 85 tumors, respectively. Among the 35 p16 ink4a -positive tumors, 10 lacked (hr)HPV-DNA (29 %). Among the 50 p16 ink4a -negative tumors, (hr)HPV-DNA was detected in 12 cases (24 %). The median follow-up was 89.20 months (range 1.7–189.5 months). P16 ink4a -overexpression, but not (hr)HPV-DNA positivity of the primary tumor, was correlated with prolonged overall survival (OS) (p = 0.009). P16 ink4a -overexpression predicted a better response to radiotherapy (p < 0.001). Univariate analysis has demonstrated that age (p = 0.025), tumor grade (p = 0.001), lymph node metastasis (p < 0.001), FIGO stage (p < 0.001), p16 ink4a -overexpression (p = 0.022), and adjuvant RTX (p < 0.001) were prognostic factors for OS. Multivariate analysis has demonstrated that lymph node metastasis (HR 1–2.74, 95 % CI 1.50–5.02, p = 0.019), tumor grade (HR 1–2.80, 95 % CI 1.33–5.90, p = 0.007) and p16 ink4a -overexpression (HR 1–2.11, 95 % CI 1.13–3.95, p = 0.001) are independent prognostic factors. The discovered overlap suggests the use of p16 ink4a in combination with HPV-DNA detection as an ancillary test for future research and clinical studies in vSCC. The prognostic and predictive value of p16 ink4a -overexpression should be tested in larger cohort studies. The online version of this article (doi:10.1186/s12885-016-2503-y) contains supplementary material, which is available to authorized users

  16. The H3K27me3 demethylase JMJD3 contributes to the activation of the INK4A-ARF locus in response to oncogene- and stress-induced senescence

    DEFF Research Database (Denmark)

    Agger, Karl; Cloos, Paul A C; Rudkjaer, Lise

    2009-01-01

    The tumor suppressor proteins p16INK4A and p14ARF, encoded by the INK4A-ARF locus, are key regulators of cellular senescence. The locus is epigenetically silenced by the repressive H3K27me3 mark in normally growing cells, but becomes activated in response to oncogenic stress. Here, we show that e...... in mouse embryonic fibroblasts results in suppression of p16Ink4a and p19Arf expression and in their immortalization....

  17. p16 as a diagnostic marker of cervical neoplasia: a tissue microarray study of 796 archival specimens

    DEFF Research Database (Denmark)

    Lesnikova, Iana; Lidang, Marianne; Hamilton-Dutoit, Stephen

    2009-01-01

    from archival formalin fixed, paraffin-embedded donor tissues from 796 patients, and included cases of cervical intraepithelial neoplasia (CIN)1 (n = 249), CIN2 (n = 233), CIN3 (n = 181), and invasive cervical carcinoma (n = 133). p16INK4a expression was scored using two different protocols: 1......BACKGROUND: To evaluate the usefulness of this biomarker in the diagnosis of cases of cervical neoplasia we studied the immunohistochemical expression of p16INK4a in a large series of archival cervical biopsies arranged into tissue microarray format. METHODS: TMAs were constructed with tissue cores...... dysplasia or the presence of invasive carcinoma. CONCLUSION: Immunohistochemical analysis of p16INK4a expression is a useful diagnostic tool. Expression is related to the degree of histological dysplasia, suggesting that it may have prognostic and predicative value in the management of cervical neoplasia....

  18. Immunophenotypic Analysis in Early Müllerian Serous Carcinogenesis.

    Science.gov (United States)

    Nafisi, Houman; Ghorab, Zeina; Ismill, Nadia; Dubé, Valerie; Plotkin, Anna; Han, Guangming; Cesari, Matthew; Lu, Fang-I; Saad, Reda; Khalifa, Mahmoud; Nofech-Mozes, Sharon

    2015-09-01

    Studies on the immunophenotypes of early forms of serous carcinoma arising from female genital tract are limited. We aimed to examine p53, p16(Ink4a), estrogen receptor (ER), progesterone receptor (PR), ERBB2, WT1, and Ki-67 protein expression in endometrial intraepithelial carcinoma (n=29), serous tubal intraepithelial lesion (n=4) and carcinoma (STIC, n=10), and the putative precursor p53 signature (n=11). Among endometrial intraepithelial carcinoma, 80% demonstrated p53 overexpression and 10% were consistent with a null phenotype. p16(Ink4a) immunostaining were observed in all endometrial intraepithelial carcinoma cases. ER, PR, ERBB2, and WT1 were positive in 54%, 25%, 11%, and 18% of cases, respectively. STIC cases demonstrated p53 overexpression and null phenotype in 90% and 10%, respectively. All STIC cases were p16(Ink4a) and WT1 positive, whereas ER and PR were positive in 70% and 20%, respectively. All STICs were negative for ERBB2. Among serous tubal intraepithelial lesion cases, 75% demonstrated p53 overexpression and 25% a null phenotype. p53 was positive in all 11 p53 signature cases, whereas p16(Ink4a) was universally negative. Finally, ER and PR were positive in 100% and 73% of p53 signature cases, respectively. These results suggest that p16(Ink4a) has a role in early Müllerian serous carcinogenesis but is absent in the earliest noncommitted lesion. p16(Ink4a) immunohistochemistry can be used as an adjunct confirmatory tool in p53-null cases with limited surface area.

  19. Composite Biomarkers For Non-invasive Screening, Diagnosis And Prognosis Of Colorectal Cancer

    KAUST Repository

    Mansour, Hicham

    2014-09-11

    The present invention concerns particular biomarkers for diagnosing and/or prognosticating colorectal cancer, in particular in a non-invasive manner. The methods and compositions concern analysis of methylation patterns of one or more genes from a set of 29 genes identified as described herein. In certain embodiments, the gene set includes at least P15.INK4b, SST, GAS7, CNRIP1, and PIK3CG.

  20. Composite Biomarkers For Non-invasive Screening, Diagnosis And Prognosis Of Colorectal Cancer

    KAUST Repository

    Mansour, Hicham; Incitti, Roberto; Bajic, Vladimir B.

    2014-01-01

    The present invention concerns particular biomarkers for diagnosing and/or prognosticating colorectal cancer, in particular in a non-invasive manner. The methods and compositions concern analysis of methylation patterns of one or more genes from a set of 29 genes identified as described herein. In certain embodiments, the gene set includes at least P15.INK4b, SST, GAS7, CNRIP1, and PIK3CG.

  1. The Role of BRCA1 in Suppressing Epithelial Mesenchymal Transition in Mammary Gland and Tumor Development

    Science.gov (United States)

    2016-11-01

    Berton D, Nicholls M, Srinivasan D, Raman R, Girshik S, Kigonya P, Alonso S, Sanbhadti R, Barletta S, Pot D, Sheth M, Demchok JA, Mills Shaw KR, Yang L...443:421–426. 8. Krishnamurthy J, Ramsey MR, Ligon KL, Torrice C, Koh A, Bonner-Weir S, Sharpless NE. p16INK4a induces an age-dependent decline in

  2. The DNA damage checkpoint precedes activation of ARF in response to escalating oncogenic stress during tumorigenesis

    Czech Academy of Sciences Publication Activity Database

    Evangelou, K.; Bartkova, J.; Kotsinas, A.; Pateras, I.S.; Liontos, M.; Velimezi, G.; Košař, Martin; Liloglou, T.; Trougakos, I.P.; Dyrskjot, L.; Andersen, C.J.; Papaioannou, G.; Drosos, A.; Papafotiou, M.; Hodný, Zdeněk; Sosa-Pineda, B.; Wu, X.R.; Klinakis, A.; Orntoft, T.; Lukas, J.; Bartek, Jiří; Gorgoulis, V.G.

    2013-01-01

    Roč. 20, č. 11 (2013), s. 1485-1497 ISSN 1350-9047 Institutional support: RVO:68378050 Keywords : ARF * carcinogenesis * DDR * E2F1 * p16(INK4A) Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 8.385, year: 2013

  3. Do senescence markers correlate in vitro and in situ within individual human donors?

    DEFF Research Database (Denmark)

    Waaijer, Mariëtte E C; Gunn, David A; van Heemst, Diana

    2018-01-01

    Little is known on how well senescence markers in vitro and in situ correlate within individual donors. We studied correlations between the same and different in vitro markers. Furthermore, we tested correlations between in vitro markers with in situ p16INK4a positivity.From 100 donors (20-91 yea...

  4. Absent/weak CD44 intensity and positive human papillomavirus (HPV) status in oropharyngeal squamous cell carcinoma indicates a very high survival

    International Nuclear Information System (INIS)

    Näsman, Anders; Nordfors, Cecilia; Grün, Nathalie; Munck-Wikland, Eva; Ramqvist, Torbjörn; Marklund, Linda; Lindquist, David; Dalianis, Tina

    2013-01-01

    Patients with human papillomavirus DNA positive (HPV DNA +) oropharyngeal squamous cell carcinoma (OSCC) have better clinical outcome than those with HPV DNA negative (HPV DNA −) OSCC upon intensive oncological treatment. All HPV DNA + OSCC patients may not require intensive treatment, however, but before potentially deintensifying treatment, additional predictive markers are needed. Here, we examined HPV, p16 INK4a , and CD44 in OSCC in correlation to clinical outcome. Pretreatment tumors from 290 OSCC patients, the majority not receiving chemotherapy, were analyzed for HPV DNA by Luminex and for p16 INK4a and CD44 by immunohistochemistry. 225/290 (78%) tumors were HPV DNA + and 211/290 (73%) overexpressed p16 INK4a , which correlated to presence of HPV (P < 0.0001). Presence of HPV DNA, absent/weak CD44 intensity staining correlated to favorable 3-year disease-free survival (DFS) and overall survival (OS) by univariate and multivariate analysis, and likewise for p16 INK4a by univariate analysis. Upon stratification for HPV, HPV DNA + OSCC with absent/weak CD44 intensity presented the significantly best 3-year DFS and OS, with >95% 3-year DFS and OS. Furthermore, in HPV DNA + OSCC, p16 INK4a + overexpression correlated to a favorable 3-year OS. In conclusion, patients with HPV DNA + and absent/weak CD44 intensity OSCC presented the best survival and this marker combination could possibly be used for selecting patients for tailored deintensified treatment in prospective clinical trials. Absence of/weak CD44 or presence of human papillomavirus (HPV) DNA was shown as a favorable prognostic factors in tonsillar and tongue base cancer. Moreover, patients with the combination of absence of/weak CD44 and presence of HPV DNA presented a very favorable outcome. Therefore, we suggest that this marker combination could potentially be used to single out patients with a high survival that could benefit from a de-escalated oncological treatment

  5. Impact of HPV infection on oral squamous cell carcinoma.

    Science.gov (United States)

    Götz, Carolin; Drecoll, Enken; Straub, Melanie; Bissinger, Oliver; Wolff, Klaus-Dietrich; Kolk, Andreas

    2016-11-22

    Head and neck squamous cell carcinomas (HNSCC) are often divided by their aetiology. Noxae associated collectives are compared with the human papilloma virus (HPV)-associated group, whereas different localisations of oral (OSCC) and oropharyngeal (OPSCC) squamous cell carcinomas are mostly discussed as one single group. Our aim was to show that classification by aetiology is not appropriate for OSCC. HPV DNA was detected by PCR in 7 (3.47%) patients, and we identified 12 (5.94%) positive (+) cases by p16INK4a immunostaining. Only 4 (1.98%) of the p16INK4a+ cases were + for HPV using PCR. Our homogenous collective of OSCC allowed us to compare HPV+ and HPV negative (-) patients without creating bias for tumour localisation, age, gender or tumour stage. After testing OSCC samples for HPV positivity, we compared the results of two commonly used HPV detection methods, p16INK4a immunostaining and HPV DNA-related PCR, on 202 OSCC patients. HPV subtypes were determined with an HPV LCD Array Kit. Clinicopathological features of the patients were analysed, and the disease specific survival rates (DSS) for HPV+ and HPV- patients were obtained. p16INK4a immunostaining is a not a reliable HPV detection method for OSCC. Positive p16INK4a immunostaining did not agree with + results from PCR of HPV DNA. Furthermore, the influence of HPV-related oncogenic transformation in OSCC is overestimated. The significance of HPV infection remains clinically unclear, and its influence on survival rates is not relevant to OSCC cases.

  6. Up-regulation of leucocytes genes implicated in telomere dysfunction and cellular senescence correlates with depression and anxiety severity scores.

    Directory of Open Access Journals (Sweden)

    Jean-Raymond Teyssier

    Full Text Available BACKGROUND: Major depressive disorder (MDD is frequently associated with chronic medical illness responsible of increased disability and mortality. Inflammation and oxidative stress are considered to be the major mediators of the allostatic load, and has been shown to correlate with telomere erosion in the leucocytes of MDD patients, leading to the model of accelerated aging. However, the significance of telomere length as an exclusive biomarker of aging has been questioned on both methodological and biological grounds. Furthermore, telomeres significantly shorten only in patients with long lasting MDD. Sensitive and dynamic functional biomarkers of aging would be clinically useful to evaluate the somatic impact of MDD. METHODOLOGY: To address this issue we have measured in the blood leucocytes of MDD patients (N=17 and controls (N=16 the expression of two genes identified as robust biomarkers of human aging and telomere dysfunction: p16(INK4a and STMN1. We have also quantified the transcripts of genes involved in the repair of oxidative DNA damage at telomeres (OGG1, telomere regulation and elongation (TERT, and in the response to biopsychological stress (FOS and DUSP1. RESULTS: The OGG1, p16(INK4a, and STMN1 gene were significantly up-regulated (25 to 100% in the leucocytes of MDD patients. Expression of p16(INK4a and STMN1 was directly correlated with anxiety scores in the depression group, and that of p16(INK4a, STMN and TERT with the depression and anxiety scores in the combined sample (MDD plus controls. Furthermore, we identified a unique correlative pattern of gene expression in the leucocytes of MDD subjects. CONCLUSIONS: Expression of p16(INK4 and STMN1 is a promising biomarker for future epidemiological assessment of the somatic impact of depressive and anxious symptoms, at both clinical and subclinical level in both depressive patients and general population.

  7. Immunohistochemical expression of p53, p16 and hTERT in oral squamous cell carcinoma and potentially malignant disorders

    Directory of Open Access Journals (Sweden)

    Aline Correa Abrahao

    2011-02-01

    Full Text Available Oral carcinogenesis is a multi-step process. One possible step is the development of potentially malignant disorders known as leukoplakia and erytroplakia. The objective of this study was to use immunohistochemistry to analyze the patterns of expression of the cell-cycle regulatory proteins p53 and p16INK4a in potentially malignant disorders (PMD of the oral mucosa (with varying degrees of dysplasia and in oral squamous cell carcinomas (OSCC to correlate them with the expression of telomerase (hTERT. Fifteen PMD and 30 OSCC tissue samples were analyzed. Additionally, 5 cases of oral epithelial hyperplasia (OEH were added to analyze clinically altered mucosa presenting as histological hyperplasia without dysplasia. p53 positivity was observed in 93.3% of PMD, in 63.3% of OSCC and in 80% of OEH. Although there was no correlation between p53 expression and the grade of dysplasia, all cases with severe dysplasia presented p53 suprabasal immunoexpression. p16INK4a expression was observed in 26.7% of PMD, in 43.3% of OSCC and in 2 cases of OEH. The p16INK4a expression in OEH, PMD and OSCC was unable to differentiate non-dysplastic from dysplastic oral epithelium. hTERT positivity was observed in all samples of OEH and PMD and in 90% of OSCC. The high hTERT immunoexpression in all three lesions indicates that telomerase is present in clinically altered oral mucosa but does not differentiate hyperplastic from dysplastic oral epithelium. In PMD of the oral mucosa, the p53 immunoexpression changes according to the degree of dysplasia by mechanisms independent of p16INK4a and hTERT.

  8. Human Papillomavirus 16 Infection and TP53 Mutation: Two Distinct Pathogeneses for Oropharyngeal Squamous Cell Carcinoma in an Eastern Chinese Population

    OpenAIRE

    Wang, Zhen; Xia, Rong-Hui; Ye, Dong-Xia; Li, Jiang

    2016-01-01

    Objectives To investigate the clinicopathological characteristics, human papillomavirus (HPV) infection, p53 expression, and TP53 mutations in oropharyngeal squamous cell carcinoma (OPSCC) and determine their utility as prognostic predictors in a primarily eastern Chinese population. Methods The HPV infection status was tested via p16INK4A immunohistochemistry and validated using PCR, reverse blot hybridization and in situ hybridization (ISH) in 188 OPSCC samples. p53 expression levels and TP...

  9. Regulation of hTERT Expression and Function in Newly Immortalized p53(+) Human Mammary Epithelial Cell Lines

    Science.gov (United States)

    2008-06-01

    senescence: Putting the brakes on tumor develop- ment. Cancer Res 2006; 66:2881-4. 17. Jones CJ, Kipling D, Morris M, Hepburn P, Skinner J, Bounacer A...A, Bonner-Weir S, Sharpless NE. P16ink4a induces an age-dependent decline in islet regenerative potential. Nature 2006; 443:453-7. 67...195L HMEC (Group A) fall into two categories : genes previously iden- tified as cancer-associated (including several antigens pro- posed as cancer

  10. HPV Virus Transcriptional Status Assessment in a Case of Sinonasal Carcinoma.

    Science.gov (United States)

    Ilardi, Gennaro; Russo, Daniela; Varricchio, Silvia; Salzano, Giovanni; Dell'Aversana Orabona, Giovanni; Napolitano, Virginia; Di Crescenzo, Rosa Maria; Borzillo, Alessandra; Martino, Francesco; Merolla, Francesco; Mascolo, Massimo; Staibano, Stefania

    2018-03-16

    Human Papilloma Virus (HPV) can play a causative role in the development of sinonasal tract malignancies. In fact, HPV may be the most significant causative agent implicated in sinonasal tumorigenesis and is implicated in as many as 21% of sinonasal carcinomas. To date, there are no definitive, reliable and cost-effective, diagnostic tests approved by the FDA for the unequivocal determination of HPV status in head and neck cancers. We followed an exhaustive algorithm to correctly test HPV infection, including a sequential approach with p16INK4a IHC, viral DNA genotyping and in situ hybridization for E6/E7 mRNA. Here, we report a case of sinonasal carcinoma with discordant results using HPV test assays. The tumor we describe showed an irregular immunoreactivity for p16INK4a, and it tested positive for HPV DNA; nevertheless, it was negative for HR-HPV mRNA. We discuss the possible meaning of this discrepancy. It would be advisable to test HPV transcriptional status of sinonasal carcinoma on a diagnostic routine basis, not only by p16INK4a IHC assay, but also by HPV DNA genotyping and HR-HPV mRNA assessment.

  11. Promoter Methylation of RASSF1A Associates to Adult Secondary Glioblastomas and Pediatric Glioblastomas.

    Science.gov (United States)

    Muñoz, Jorge; Inda, María Del Mar; Lázcoz, Paula; Zazpe, Idoya; Fan, Xing; Alfaro, Jorge; Tuñón, Teresa; Rey, Juan A; Castresana, Javier S

    2012-01-01

    While allelic losses and mutations of tumor suppressor genes implicated in the etiology of astrocytoma have been widely assessed, the role of epigenetics is still a matter of study. We analyzed the frequency of promoter hypermethylation by methylation-specific PCR (MSP) in five tumor suppressor genes (PTEN, MGMT, RASSF1A, p14(ARF), and p16(INK4A)), in astrocytoma samples and cell lines. RASSF1A was the most frequently hypermethylated gene in all grades of astrocytoma samples, in cell lines, and in adult secondary GBM. It was followed by MGMT. PTEN showed a slight methylation signal in only one GBM and one pilocytic astrocytoma, and in two cell lines; while p14(ARF) and p16(INK4A) did not show any evidence of methylation in primary tumors or cell lines. In pediatric GBM, RASSF1A was again the most frequently altered gene, followed by MGMT; PTEN, p14 and p16 showed no alterations. Lack or reduced expression of RASSF1A in cell lines was correlated with the presence of methylation. RASSF1A promoter hypermethylation might be used as a diagnostic marker for secondary GBM and pediatric GBM. Promoter hypermethylation might not be an important inactivation mechanism in other genes like PTEN, p14(ARF) and p16(INK4A), in which other alterations (mutations, homozygous deletions) are prevalent.

  12. Human Papillomavirus and Oropharyngeal Squamous Cell Carcinoma: A Case-Control Study regarding Tobacco and Alcohol Consumption

    Directory of Open Access Journals (Sweden)

    F. Farshadpour

    2011-01-01

    Full Text Available We aimed to determine the role of HPV in the pathogenesis and outcome of oropharyngeal squamous cell carcinoma (OSCC in lifelong nonsmoking and nondrinking patients. A case-case analysis was performed to compare the presence of HPV-DNA in tumor cells of 16 nonsmoking and nondrinking with 16 matched smoking and drinking patients (matching criteria: age at incidence, gender, tumor sublocation, tumor stage. HPV was detected using 2 PCR tests, FISH analysis, and p16INK4A immunostaining. Nonsmoking and nondrinking patients had more HPV-positive tumors than smoking and drinking patients (n=12; 75% versus n=2; 13%; P<0.001. All HPV-positive tumors showed p16INK4A overexpression, and 1 HPV-negative tumor had p16INK4A overexpression, (P<0.001. Overall survival and disease-specific survival were higher for HPV-positive compared to HPV-negative cases (P=0.027, P=0.039, resp.. In conclusion, HPV is strongly associated with OSCC of nonsmoking and nondrinking patients. Specific diagnostic and therapeutic actions should be considered for these patients to achieve a better prognosis.

  13. Premeiotic germ cell defect in seminiferous tubules of Atm-null testis

    International Nuclear Information System (INIS)

    Takubo, Keiyo; Hirao, Atsushi; Ohmura, Masako; Azuma, Masaki; Arai, Fumio; Nagamatsu, Go; Suda, Toshio

    2006-01-01

    Lifelong spermatogenesis is maintained by coordinated sequential processes including self-renewal of stem cells, proliferation of spermatogonial cells, meiotic division, and spermiogenesis. It has been shown that ataxia telangiectasia-mutated (ATM) is required for meiotic division of the seminiferous tubules. Here, we show that, in addition to its role in meiosis, ATM has a pivotal role in premeiotic germ cell maintenance. ATM is activated in premeiotic spermatogonial cells and the Atm-null testis shows progressive degeneration. In Atm-null testicular cells, differing from bone marrow cells of Atm-null mice, reactive oxygen species-mediated p16 Ink4a activation does not occur in Atm-null premeiotic germ cells, which suggests the involvement of different signaling pathways from bone marrow defects. Although Atm-null bone marrow undergoes p16 Ink4a -mediated cellular senescence program, Atm-null premeiotic germ cells exhibited cell cycle arrest and apoptotic elimination of premeiotic germ cells, which is different from p16 Ink4a -mediated senescence

  14. Worldwide human papillomavirus genotype attribution in over 2000 cases of intraepithelial and invasive lesions of the vulva.

    Science.gov (United States)

    de Sanjosé, Silvia; Alemany, Laia; Ordi, Jaume; Tous, Sara; Alejo, Maria; Bigby, Susan M; Joura, Elmar Armin; Maldonado, Paula; Laco, Jan; Bravo, Ignacio G; Vidal, August; Guimerà, Núria; Cross, Paul; Wain, Gerard V; Petry, Karl Ulrich; Mariani, Luciano; Bergeron, Christine; Mandys, Václav; Sica, Adela Rosa; Félix, Ana; Usubutun, Alp; Seoud, Muhieddine; Hernández-Suárez, Gustavo; Nowakowski, Andrzej Marcin; Wilson, Godfrey; Dalstein, Veronique; Hampl, Monika; Kasamatsu, Elena Sachiko; Lombardi, Luis Estuardo; Tinoco, Leopoldo; Alvarado-Cabrero, Isabel; Perrotta, Myriam; Bhatla, Neerja; Agorastos, Theodoros; Lynch, Charles F; Goodman, Marc T; Shin, Hai-Rim; Viarheichyk, Halina; Jach, Robert; Cruz, M O L Eugenia; Velasco, Julio; Molina, Carla; Bornstein, Jacob; Ferrera, Annabelle; Domingo, Efren Javier; Chou, Cheng-Yang; Banjo, Adekunbiola F; Castellsagué, Xavier; Pawlita, Michael; Lloveras, Belén; Quint, Wim G V; Muñoz, Nubia; Bosch, F Xavier

    2013-11-01

    Human papillomavirus (HPV) contribution in vulvar intraepithelial lesions (VIN) and invasive vulvar cancer (IVC) is not clearly established. This study provides novel data on HPV markers in a large series of VIN and IVC lesions. Histologically confirmed VIN and IVC from 39 countries were assembled at the Catalan Institute of Oncology (ICO). HPV-DNA detection was done by polymerase chain reaction using SPF-10 broad-spectrum primers and genotyping by reverse hybridisation line probe assay (LiPA25) (version 1). IVC cases were tested for p16(INK4a) by immunohistochemistry (CINtec histology kit, ROCHE). An IVC was considered HPV driven if both HPV-DNA and p16(INK4a) overexpression were observed simultaneously. Data analyses included algorithms allocating multiple infections to calculate type-specific contribution and logistic regression models to estimate adjusted prevalence (AP) and its 95% confidence intervals (CI). Of 2296 cases, 587 were VIN and 1709 IVC. HPV-DNA was detected in 86.7% and 28.6% of the cases respectively. Amongst IVC cases, 25.1% were both HPV-DNA and p16(INK4a) positive. IVC cases were largely keratinising squamous cell carcinoma (KSCC) (N=1234). Overall prevalence of HPV related IVC cases was highest in younger women for any histological subtype. SCC with warty or basaloid features (SCC_WB) (N=326) were more likely to be HPV and p16(INK4a) positive (AP=69.5%, CI=63.6-74.8) versus KSCC (AP=11.5%, CI=9.7-13.5). HPV 16 was the commonest type (72.5%) followed by HPV 33 (6.5%) and HPV 18 (4.6%). Enrichment from VIN to IVC was significantly high for HPV 45 (8.5-fold). Combined data from HPV-DNA and p16(INK4a) testing are likely to represent a closer estimate of the real fraction of IVC induced by HPV. Our results indicate that HPV contribution in invasive vulvar cancer has probably been overestimated. HPV 16 remains the major player worldwide. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Increased p50/p50 NF-κB Activation in Human Papillomavirus Type 6- or Type 11-Induced Laryngeal Papilloma Tissue

    Science.gov (United States)

    Vancurova, Ivana; Wu, Rong; Miskolci, Veronika; Sun, Shishinn

    2002-01-01

    We have observed elevated NF-κB DNA-binding activity in nuclear extracts from human papillomavirus type 6- and 11-infected laryngeal papilloma tissues. The predominant DNA-binding species is the p50/p50 homodimer. The elevated NF-κB activity could be correlated with a reduced level of cytoplasmic IκBβ and could be associated with the overexpression of p21CIP1/WAF1 in papilloma cells. Increased NF-κB activity and cytoplasmic accumulation of p21CIP1/WAF1 might counteract death-promoting effects elicited by overexpressed PTEN and reduced activation of Akt and STAT3 previously noted in these tissues. PMID:11773428

  16. Synemin promotes AKT-dependent glioblastoma cell proliferation by antagonizing PP2A

    OpenAIRE

    Pitre, Aaron; Davis, Nathan; Paul, Madhumita; Orr, A Wayne; Skalli, Omar

    2012-01-01

    The intermediate filament protein synemin is present in astrocyte progenitors and glioblastoma cells but not in mature astrocytes. Here we demonstrate a role for synemin in enhancing glioblastoma cell proliferation and clonogenic survival, as synemin RNA interference decreased both behaviors by inducing G1 arrest along with Rb hypophosphorylation and increased protein levels of the G1/S inhibitors p21Cip1 and p27Kip1. Akt involvement was demonstrated by decreased phosphorylation of its substr...

  17. [Inhibitory effect of exogenous insulin-like growth factor binding protein 7 on proliferation of human breast cancer cell line MDA-MB-453 and its mechanism].

    Science.gov (United States)

    Yuan, Lei; Fan, Wen-Juan; Yang, Xu-Guang; Rao, Shu-Mei; Song, Jin-Ling; Song, Guo-Hua

    2013-10-25

    The present study was to investigate the effects of exogenous insulin-like growth factor binding protein 7 (IGFBP7) on the proliferation of human breast cancer cell line MDA-MB-453 and its possible mechanism. By means of MTT method in vitro, the results showed exogenous IGFBP7 inhibited the growth of MDA-MB-453 cells (IC50 of IGFBP7 = 8.49 μg/mL) in time- and concentration-dependent manner. SB203580, p38(MAPK) inhibitor, blocked the anti-proliferative effect of exogenous IGFBP7. The flow cytometry assay showed that exogenous IGFBP7 remarkably induced G0/G1 arrest in MDA-MB-453 cells. The Western blot showed that exogenous IGFBP7 promoted phosphorylation of p38(MAPK), up-regulated expression of p21(CIP1/WAF1), and inhibited phosphorylation of Rb. SB203580 restrained exogenous IGFBP7-induced regulation of p21(CIP1/WAF1) and p-Rb in MDA-MB-453 cells. In conclusion, the present study suggests that exogenous IGFBP7 could activate the p38(MAPK) signaling pathway, upregulate p21(CIP1/WAF1) expression, inhibit phosphorylation of Rb, and finally induce G0/G1 arrest in MDA-MB-453 cells.

  18. Homocysteine inhibits hepatocyte proliferation via endoplasmic reticulum stress.

    Directory of Open Access Journals (Sweden)

    Xue Yu

    Full Text Available Homocysteine is an independent risk factor for coronary, cerebral, and peripheral vascular diseases. Recent studies have shown that levels of homocysteine are elevated in patients with impaired hepatic function, but the precise role of homocysteine in the development of hepatic dysfunction is unclear. In this study, we examined the effect of homocysteine on hepatocyte proliferation in vitro. Our results demonstrated that homocysteine inhibited hepatocyte proliferation by up-regulating protein levels of p53 as well as mRNA and protein levels of p21(Cip1 in primary cultured hepatocytes. Homocysteine induced cell growth arrest in p53-positive hepatocarcinoma cell line HepG2, but not in p53-null hepatocarcinoma cell line Hep3B. A p53 inhibitor pifithrin-α inhibited the expression of p21(Cip1 and attenuated homocysteine-induced cell growth arrest. Homocysteine induced TRB3 expression via endoplasmic reticulum stress pathway, resulting in Akt dephosphorylation. Knock-down of endogenous TRB3 significantly suppressed the inhibitory effect of homocysteine on cell proliferation and the phosphorylation of Akt. LiCl reversed homocysteine-mediated cell growth arrest by inhibiting TRB3-mediated Akt dephosphorylation. These results demonstrate that both TRB3 and p21(Cip1 are critical molecules in the homocysteine signaling cascade and provide a mechanistic explanation for impairment of liver regeneration in hyperhomocysteinemia.

  19. Maintenance treatment with azacytidine for patients with high-risk myelodysplastic syndromes (MDS) or acute myeloid leukaemia following MDS in complete remission after induction chemotherapy

    DEFF Research Database (Denmark)

    Grövdal, Michael; Karimi, Mohsen; Khan, Rasheed

    2010-01-01

    chemotherapy. Sixty patients were enrolled and treated by standard induction chemotherapy. Patients that reached CR started maintenance therapy with subcutaneous azacytidine, 5/28 d until relapse. Promoter-methylation status of CDKN2B (P15 ink4b), CDH1 and HIC1 was examined pre-induction, in CR and 6, 12...... and 24 months post CR. Twenty-four (40%) patients achieved CR after induction chemotherapy and 23 started maintenance treatment with azacytidine. Median CR duration was 13.5 months, >24 months in 17% of the patients, and 18-30.5 months in the four patients with trisomy 8. CR duration was not associated......-IV thrombocytopenia and neutropenia occurred after 9.5 and 30% of the cycles, respectively, while haemoglobin levels increased during treatment. 5-azacytidine treatment is safe, feasible and may be of benefit in a subset of patients....

  20. Prognostic implications of molecular and immunohistochemical profiles of the Rb and p53 cell cycle regulatory pathways in primary non-small cell lung carcinoma.

    LENUS (Irish Health Repository)

    Burke, Louise

    2012-02-03

    PURPOSE: Many studies have highlighted the aberrant expression and prognostic significance of individual proteins in either the Rb (particularly cyclin D1, p16INK4A, and pRb) or the p53 (p53 and p21Waf1) pathways in non-small cell lung cancer. We hypothesize that cumulative abnormalities within each and between these pathways would have significant prognostic potential regarding survival. EXPERIMENTAL DESIGN: Our study population consisted of 106 consecutive surgically resected cases of predominantly early-stage non-small cell lung cancer from the National Cancer Institute-Mayo Clinic series, and assessment of proteins involved both immunohistochemical (cyclin D1, p21Waf1, pRb, p16INK4A, and p53) and mutational analysis (p53) in relationship to staging and survival. RESULTS: Cyclin D1 overexpression was noted in 48% of the tumors, p16INK4A negative in 53%, pRb negative in 17%, p53 immunopositive in 50%, p53 mutation frequency in 48%, and p21(Waf1) overexpression in 47%, none with prognostic significance. Cyclin D1 overexpression in pRb-negative tumors revealed a significantly worse prognosis with a mean survival of 2.3 years (P = 0.004). A simultaneous p53 mutation dramatically reduced the mean survival time to 0.9 years (P = 0.007). Cyclin D1 overexpression with either a p53 mutation or a p53 overexpression was also associated with a significantly poorer prognosis (P = 0.0033 and 0.0063, respectively). CONCLUSIONS: Some cumulative abnormalities in the Rb and p53 pathways (e.g., cyclin D1 overexpression and p53 mutations) significantly cooperate to predict a poor prognosis; however, the complexity of the cell cycle protein interaction in any given tumor warrants caution in interpreting survival results when specific protein abnormalities are taken in isolation.

  1. Chromogenic In Situ Hybridization and p16/Ki67 Dual Staining on Formalin-Fixed Paraffin-Embedded Cervical Specimens: Correlation with HPV-DNA Test, E6/E7 mRNA Test, and Potential Clinical Applications

    Directory of Open Access Journals (Sweden)

    Roberta Zappacosta

    2013-01-01

    Full Text Available Although HPV-DNA test and E6/E7 mRNA analyses remain the current standard for the confirmation of human papillomavirus (HPV infections in cytological specimens, no universally adopted techniques exist for the detection of HPV in formalin-fixed paraffin-embedded samples. Particularly, in routine laboratories, molecular assays are still time-consuming and would require a high level of expertise. In this study, we investigated the possible use of a novel HPV tyramide-based chromogenic in situ hybridization (CISH technology to locate HPV on tissue specimens. Then, we evaluate the potential usefulness of p16INK4a/Ki-67 double stain on histological samples, to identify cervical cells expressing HPV E6/E7 oncogenes. In our series, CISH showed a clear signal in 95.2% of the specimens and reached a sensitivity of 86.5%. CISH positivity always matched with HPV-DNA positivity, while 100% of cases with punctated signal joined with cervical intraepithelial neoplasia grade 2 or worse (CIN2+. p16/Ki67 immunohistochemistry gave an interpretable result in 100% of the cases. The use of dual stain significantly increased the agreement between pathologists, which reached 100%. Concordance between dual stain and E6/E7 mRNA test was 89%. In our series, both CISH and p16INK4a/Ki67 dual stain demonstrated high grade of performances. In particular, CISH would help to distinguish episomal from integrated HPV, in order to allow conclusions regarding the prognosis of the lesion, while p16INK4a/Ki67 dual stain approach would confer a high level of standardization to the diagnostic procedure.

  2. Chromogenic In Situ Hybridization and p16/Ki67 Dual Staining on Formalin-Fixed Paraffin-Embedded Cervical Specimens: Correlation with HPV-DNA Test, E6/E7 mRNA Test, and Potential Clinical Applications

    Science.gov (United States)

    Zappacosta, Roberta; Colasante, Antonella; Viola, Patrizia; D'Antuono, Tommaso; Lattanzio, Giuseppe; Capanna, Serena; Gatta, Daniela Maria Pia; Rosini, Sandra

    2013-01-01

    Although HPV-DNA test and E6/E7 mRNA analyses remain the current standard for the confirmation of human papillomavirus (HPV) infections in cytological specimens, no universally adopted techniques exist for the detection of HPV in formalin-fixed paraffin-embedded samples. Particularly, in routine laboratories, molecular assays are still time-consuming and would require a high level of expertise. In this study, we investigated the possible use of a novel HPV tyramide-based chromogenic in situ hybridization (CISH) technology to locate HPV on tissue specimens. Then, we evaluate the potential usefulness of p16INK4a/Ki-67 double stain on histological samples, to identify cervical cells expressing HPV E6/E7 oncogenes. In our series, CISH showed a clear signal in 95.2% of the specimens and reached a sensitivity of 86.5%. CISH positivity always matched with HPV-DNA positivity, while 100% of cases with punctated signal joined with cervical intraepithelial neoplasia grade 2 or worse (CIN2+). p16/Ki67 immunohistochemistry gave an interpretable result in 100% of the cases. The use of dual stain significantly increased the agreement between pathologists, which reached 100%. Concordance between dual stain and E6/E7 mRNA test was 89%. In our series, both CISH and p16INK4a/Ki67 dual stain demonstrated high grade of performances. In particular, CISH would help to distinguish episomal from integrated HPV, in order to allow conclusions regarding the prognosis of the lesion, while p16INK4a/Ki67 dual stain approach would confer a high level of standardization to the diagnostic procedure. PMID:24369532

  3. The Relationship Between Human Papillomavirus Status and Other Molecular Prognostic Markers in Head and Neck Squamous Cell Carcinomas

    International Nuclear Information System (INIS)

    Kong, Christina S.; Narasimhan, Balasubramanian; Cao Hongbin; Kwok, Shirley; Erickson, Julianna P.; Koong, Albert; Pourmand, Nader; Le, Quynh-Thu

    2009-01-01

    Purpose: To evaluate the relationship between human papillomavirus (HPV) status and known prognostic makers for head and neck cancers including tumor hypoxia, epidermal growth factor receptor (EGFR) expression and intratumoral T-cell levels and to determine the prognostic impact of these markers by HPV status. Methods and Materials: HPV status in 82 evaluable head and neck squamous cell carcinomas patients was determined by pyrosequencing and related to p16 INK4a staining and treatment outcomes. It was correlated with tumor hypoxia (tumor pO 2 and carbonic anhydrase [CAIX] staining), EGFR status, and intratumoral lymphocyte expression (CD3 staining). Results: Forty-four percent of evaluable tumors had strong HPV signal by pyrosequencing. There was a significant relationship between strong HPV signal and p16 INK4a staining as well as oropharynx location. The strong HPV signal group fared significantly better than others, both in time to progression (TTP, p = 0.008) and overall survival (OS, p = 0.004) for all patients and for the oropharyngeal subset. Positive p16 INK4a staining was associated with better TTP (p = 0.014) and OS (p = 0.00002). There was no relationship between HPV status and tumor pO 2 or CAIX staining. However, HPV status correlated inversely with EGFR reactivity (p = 0.0006) and directly with CD3(+) T-lymphocyte level (p = 0.03). Whereas CAIX and EGFR overexpression were negative prognostic factors regardless of HPV status, CD3(+) T-cell levels was prognostic only in HPV(-) tumors. Conclusion: HPV status was a prognostic factor for progression and survival. It correlated inversely with EGFR expression and directly with T-cell infiltration. The prognostic effect of CAIX and EGFR expression was not influenced by HPV status, whereas intratumoral T-cell levels was significant only for HPV(-) tumors.

  4. Human T-cell leukemia virus type 1 Tax and cell cycle progression: role of cyclin D-cdk and p110Rb.

    Science.gov (United States)

    Neuveut, C; Low, K G; Maldarelli, F; Schmitt, I; Majone, F; Grassmann, R; Jeang, K T

    1998-06-01

    Human T-cell leukemia virus type 1 is etiologically linked to the development of adult T-cell leukemia and various human neuropathies. The Tax protein of human T-cell leukemia virus type I has been implicated in cellular transformation. Like other oncoproteins, such as Myc, Jun, and Fos, Tax is a transcriptional activator. How it mechanistically dysregulates the cell cycle is unclear. Previously, it was suggested that Tax affects cell-phase transition by forming a direct protein-protein complex with p16(INK4a), thereby inactivating an inhibitor of G1-to-S-phase progression. Here we show that, in T cells deleted for p16(INK4a), Tax can compel an egress of cells from G0/G1 into S despite the absence of serum. We also show that in undifferentiated myocytes, expression of Tax represses cellular differentiation. In both settings, Tax expression was found to increase cyclin D-cdk activity and to enhance pRb phosphorylation. In T cells, a Tax-associated increase in steady-state E2F2 protein was also documented. In searching for a molecular explanation for these observations, we found that Tax forms a protein-protein complex with cyclin D3, whereas a point-mutated and transcriptionally inert Tax mutant failed to form such a complex. Interestingly, expression of wild-type Tax protein in cells was also correlated with the induction of a novel hyperphosphorylated cyclin D3 protein. Taken together, these findings suggest that Tax might directly influence cyclin D-cdk activity and function, perhaps by a route independent of cdk inhibitors such as p16(INK4a).

  5. Molecular characterization of radon-induced rat lung tumors

    International Nuclear Information System (INIS)

    Guillet Bastide, K.

    2008-11-01

    The radon gas is a well known lung carcinogenic factor in human at high doses but the cancer risk at low doses is not established. Indeed, epidemiological studies at low doses are difficult to conduct because of the human exposure to other lung carcinogenic factors. These data underlined the necessity to conduct experiments on lung tumors developed on animal model. The aim of this work was to characterize rat lung tumors by working on a series of radon-induced tumors that included adenocarcinomas (A.C.), squamous cell carcinomas (S.C.C.) and adeno-squamous carcinomas (A.S.C.), that are mixed tumors with both A.C. and S.C.C. cellular components. A C.G.H. analysis of the three types of tumors allowed us to define chromosomal recurrent unbalances and to target candidate genes potentially implicated in lung carcinogenesis, as p16Ink4a, p19Arf, Rb1, K-Ras or c-Myc. A more precise analysis of the p16Ink4a/Cdk4/Rb1 and p19Arf/Mdm2/Tp53 pathways was performed and indicated that the Rb1 pathway was frequently inactivated through an absence of p16 Ink4a protein expression, indicating that it has a major role in rat lung carcinogenesis. Finally, a comparative transcriptomic analysis of the three types of tumors allowed us to show for the first time that the complex tumors A.S.C. have a transcriptomic profile in accordance with their mixed nature but that they also display their own expression profiles specificities. This work allowed us to find molecular characteristics common to murine and human lung tumors, indicating that the model of lung tumors in rat is pertinent to search for radiation-induced lung tumors specificities and to help for a better molecular identification of this type of tumors in human. (author)

  6. Influence of HPV-status on survival of patients with tonsillar carcinomas (TSCC) treated by CO2-laser surgery plus risk adapted therapy - A 10 year retrospective single centre study.

    Science.gov (United States)

    Hoffmann, Markus; Quabius, Elgar Susanne; Tribius, Silke; Gebhardt, Stephan; Görögh, Tibor; Hedderich, Jürgen; Huber, Karen; Dunst, Jürgen; Ambrosch, Petra

    2018-01-28

    The positive prognostic value of HPV-infections in oropharyngeal squamous cell cancer (OSCC) patients has led to the initiation of prospective clinical trials testing the value of treatment de-escalation. It is unclear how to define patients potentially benefiting from de-escalated treatment, whether a positive smoking history impacts survival data and what kind of de-escalation might be best. Here, we investigate the effect of HPV-status, smoking habit and treatment design on overall survival (OS) and progression free survival (PFS) of 126 patients with tonsillar SCC (TSCC) who underwent CO 2 -laser-surgery and risk adapted adjuvant treatment. HPV-DNA-, HPV-mRNA-, and p16 INK4A -expression were analysed and results were correlated to OS and PFS. Factors tested for prognostic value included HPV-status, p16 INK4A -protein expression, therapy and smoking habit. Log rank test and p-values ≤0.05 defined significant differences between groups. The highest accuracy of data with highest significance in this study is given when the HPV-RNA-status is considered. Using p16 INK4A -expression alone or in combination with HPV-DNA-status, would have misclassified 23 and 7 patients, respectively. Smoking fully abrogates the positive impact of HPV-infection in TSCC on survival. Non-smoking HPV-positive TSCC patients show 10-year OS of 100% and 90.9% PFS when treated with adjuvant RCT. The presented data show that high-precision HPV-detection methods are needed, specifically when treatment decisions are based on the results. Furthermore, smoking habit should be included in all studies and clinical trials testing HPV-associated survival. Adjuvant RCT especially for HPV-positive non-smokers may help to avoid distant failure. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Hypersensitivity to contact inhibition provides a clue to cancer resistance of naked mole-rat.

    Science.gov (United States)

    Seluanov, Andrei; Hine, Christopher; Azpurua, Jorge; Feigenson, Marina; Bozzella, Michael; Mao, Zhiyong; Catania, Kenneth C; Gorbunova, Vera

    2009-11-17

    The naked mole-rat is the longest living rodent with a maximum lifespan exceeding 28 years. In addition to its longevity, naked mole-rats have an extraordinary resistance to cancer as tumors have never been observed in these rodents. Furthermore, we show that a combination of activated Ras and SV40 LT fails to induce robust anchorage-independent growth in naked mole-rat cells, while it readily transforms mouse fibroblasts. The mechanisms responsible for the cancer resistance of naked mole-rats were unknown. Here we show that naked mole-rat fibroblasts display hypersensitivity to contact inhibition, a phenomenon we termed "early contact inhibition." Contact inhibition is a key anticancer mechanism that arrests cell division when cells reach a high density. In cell culture, naked mole-rat fibroblasts arrest at a much lower density than those from a mouse. We demonstrate that early contact inhibition requires the activity of p53 and pRb tumor suppressor pathways. Inactivation of both p53 and pRb attenuates early contact inhibition. Contact inhibition in human and mouse is triggered by the induction of p27(Kip1). In contrast, early contact inhibition in naked mole-rat is associated with the induction of p16(Ink4a). Furthermore, we show that the roles of p16(Ink4a) and p27(Kip1) in the control of contact inhibition became temporally separated in this species: the early contact inhibition is controlled by p16(Ink4a), and regular contact inhibition is controlled by p27(Kip1). We propose that the additional layer of protection conferred by two-tiered contact inhibition contributes to the remarkable tumor resistance of the naked mole-rat.

  8. Contribution of Human papillomavirus in neuroendocrine tumors from a series of 10,575 invasive cervical cancer cases.

    Science.gov (United States)

    Alejo, Maria; Alemany, Laia; Clavero, Omar; Quiros, Beatriz; Vighi, Susana; Seoud, Muhieddine; Cheng-Yang, Chou; Garland, Suzanne M; Juanpere, Nuria; Lloreta, Josep; Tous, Sara; Klaustermeier, Jo Ellen; Quint, Wim; Bosch, F Xavier; de Sanjosé, Silvia; Lloveras, Belen

    2018-06-01

    Neuroendocrine tumors (NET) of the cervix are rare tumors with a very aggressive course. The human papillomavirus (HPV) has been linked to its etiology. The objective of this study is to describe HPV prevalence and genotype distribution of NET. Forty-nine tumors with histological neuroendocrine features were identified among 10,575 invasive cervical cancer (ICC) cases from an international study. HPV DNA detection was done using SPF10/DEIA /LiPA 25 system. Immunohistochemical (IHC) staining for neuroendocrine markers (chromogranin A, synaptophysin, CD56) and for p16 INK4a as a surrogate for HPV transforming infection was performed. In 13 samples with negative IHC for all 3 neuroendocrine markers studied, it was possible to conduct electron microscopy (EM). NET represented 0.5% of the total ICC series and HPV was detected in 42 out of 49 samples (85.7%, 95%CI:72.8%,94.1%). HPV16 was the predominant type (54.8%), followed by HPV18 (40.5%). p16 INK4a overexpression was observed in 38/44 cases (86.4%). Neuroendocrine IHC markers could be demonstrated in 24/37 (64.9%) cases. EM identified neuroendocrine granules in 8 samples with negative IHC markers. Our data confirms the association of cervical NET with HPV and p16 INK4a overexpression. Specifically, HPV16 and 18 accounted together for over 95% of the HPV positive cases. Current HPV vaccines could largely prevent these aggressive tumors. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

  9. Trisomy of the Dscr1 gene suppresses early progression of pancreatic intraepithelial neoplasia driven by oncogenic Kras

    International Nuclear Information System (INIS)

    Lee, Jang Choon; Shin, Jimin; Baek, Kwan-Hyuck

    2013-01-01

    Highlights: •A single extra copy of Dscr1 restrains progression of PanIN-1A to PanIN-1B lesions. •Dscr1 trisomy attenuates calcineurin–NFAT pathway in neoplastic ductal epithelium. •Dscr1 trisomy leads to upregulation of p15 INK4b in neoplastic ductal epithelium. •A single extra copy of Dscr1 reduces epithelial proliferation in early PanIN lesions. •Dscr1 trisomy may protect Down syndrome individuals from pancreatic cancer. -- Abstract: Individuals with Down syndrome exhibit remarkably reduced incidence of most solid tumors including pancreatic cancer. Multiple mechanisms arising from the genetic complexity underlying Down syndrome has been suggested to contribute to such a broad cancer protection. In this study, utilizing a genetically engineered mouse model of pancreatic cancer, we demonstrate that trisomy of the Down syndrome critical region-1 (Dscr1), an endogenous calcineurin inhibitor localized on chromosome 21, suppresses the progression of pancreatic intraepithelial neoplasia-1A (PanIN-1A) to PanIN-1B lesions without affecting the initiation of PanIN lesions mediated by oncogenic Kras G12D . In addition, we show that Dscr1 trisomy attenuates nuclear localization of nuclear factor of activated T-cells (NFAT) accompanied by upregulation of the p15 Ink4b tumor suppressor and reduction of cell proliferation in early PanIN lesions. Our data suggest that attenuation of calcineurin–NFAT signaling in neoplastic pancreatic ductal epithelium by a single extra copy of Dscr1 is sufficient to inhibit the progression of early PanIN lesions driven by oncogenic Kras, and thus may be a potential mechanism underlying reduced incidence of pancreatic cancer in Down syndrome individuals

  10. Use of Human Tissue to Assess the Oncogenic Activity of Melanoma-Associated Mutations

    OpenAIRE

    Chudnovsky, Yakov; Adams, Amy E.; Robbins, Paul B.; Lin, Qun; Khavari, Paul A.

    2005-01-01

    Multiple genetic alterations occur in melanoma, a lethal skin malignancy of increasing incidence1,2. These include mutations that activate Ras and two of its effector cascades, Raf and phosphoinositide 3-kinase (PI3K). Ras and Raf induction can occur via active N-Ras and B-Raf mutants as well as by gene amplification3–5. Activation of PI3K pathway components occurs by PTEN loss and by AKT amplification6–8. Melanomas also commonly display impairment of p16INK4A-CDK4-Rb and ARF-HDM2-p53 tumor s...

  11. Retinoblastoma pathway defects show differential ability to activate the constitutive DNA damage response in human tumorigenesis

    DEFF Research Database (Denmark)

    Tort, F.; Bartkova, J.; Sehested, M.

    2006-01-01

    culture models with differential defects of retinoblastoma pathway components, as overexpression of cyclin D1 or lack of p16(Ink4a), either alone or combined, did not elicit detectable DDR. In contrast, inactivation of pRb, the key component of the pathway, activated the DDR in cultured human or mouse...... with their hierarchical positions along the retinoblastoma pathway. Our data provide new insights into oncogene-evoked DDR in human tumorigenesis, with potential implications for individualized management of tumors with elevated cyclin D1 versus cyclin E, due to their distinct clinical variables and biological behavior....

  12. Biological relevance of human papillomaviruses in vulvar cancer.

    Science.gov (United States)

    Halec, Gordana; Alemany, Laia; Quiros, Beatriz; Clavero, Omar; Höfler, Daniela; Alejo, Maria; Quint, Wim; Pawlita, Michael; Bosch, Francesc X; de Sanjose, Silvia

    2017-04-01

    The carcinogenic role of high-risk human papillomavirus (HR-HPV) types in the increasing subset of vulvar intraepithelial neoplasia and vulvar cancer in young women has been established. However, the actual number of vulvar cancer cases attributed to HPV is still imprecisely defined. In an attempt to provide a more precise definition of HPV-driven vulvar cancer, we performed HPV-type-specific E6*I mRNA analyses available for 20 HR-/possible HR (pHR)-HPV types, on tissue samples from 447 cases of vulvar cancer. HPV DNA genotyping was performed using SPF10-LiPA 25 assay due to its high sensitivity in formalin-fixed paraffin-embedded tissues. Data on p16 INK4a expression was available for comparative analysis via kappa statistics. The use of highly sensitive assays covering the detection of HPV mRNA in a broad spectrum of mucosal HPV types resulted in the detection of viral transcripts in 87% of HPV DNA+ vulvar cancers. Overall concordance between HPV mRNA+ and p16 INK4a upregulation (strong, diffuse immunostaining in >25% of tumor cells) was 92% (K=0.625, 95% confidence interval (CI)=0.531-0.719). Among these cases, 83% were concordant pairs of HPV mRNA+ and p16 INK4a + and 9% were concordant pairs of HPV mRNA- and p16 INK4a -. Our data confirm the biological role of HR-/pHR-HPV types in the great majority of HPV DNA+ vulvar cancers, resulting in an HPV-attributable fraction of at least 21% worldwide. Most HPV DNA+ vulvar cancers were associated with HPV16 (85%), but a causative role for other, less frequently occurring mucosal HPV types (HPV26, 66, 67, 68, 70 and 73) was also confirmed at the mRNA level for the first time. These findings should be taken into consideration for future screening options as HPV-associated vulvar preneoplastic lesions have increased in incidence in younger women and require different treatment than vulvar lesions that develop from rare autoimmune-related mechanisms in older women.

  13. CD4+CD25+ T regulatory cells from FIV+ cats induce a unique anergic profile in CD8+ lymphocyte targets

    Directory of Open Access Journals (Sweden)

    Tompkins Mary B

    2010-11-01

    Full Text Available Abstract Background Using the FIV model, we reported previously that CD4+CD25+ T regulatory (Treg cells from FIV+ cats are constitutively activated and suppress CD4+CD25- and CD8+ T cell immune responses. In an effort to further explore Treg-mediated suppression, we asked whether Treg cells induce anergy through the alteration of production of cyclins, cyclin-dependent kinases and their inhibitors. Results Lymphocytes were obtained from control or FIV+ cats and sorted by FACS into CD4+CD25+ and CD8+ populations. Following co-culture with CD4+CD25+ cells, CD8+ targets were examined by Western blot for changes in cyclins D3, E and A, retinoblastoma (Rb protein, as well as the cyclin dependent kinase inhibitor p21cip1. Following co-culture with CD4+CD25+cells, we observed up-regulation of p21cip1 and cyclin E, with down-regulation of cyclin D3, in CD8+ cells from FIV+ cats. As expected, CD8+ targets from control cats were quiescent with little up-regulation of p21cip1 and cyclin E. There was also a lack of Rb phosphorylation in CD8+ targets consistent with late G1 cell cycle arrest. Further, IL-2 mRNA was down regulated in CD8+ cells after co-culture with CD4+CD25+ Treg cells. Following CD4+CD25+ co-culture, CD8+ targets from FIV+ cats also had increased Foxp3 mRNA expression; however, these CD8+Foxp3+ cells did not exhibit suppressor function. Conclusions Collectively, these data suggest that CD4+CD25+ Treg cells from FIV+ cats induce CD8+ anergy by disruption of normal G1 to S cell cycle progression.

  14. Increased size of solid organs in patients with Chuvash polycythemia and in mice with altered expression of HIF-1α and HIF-2α

    Science.gov (United States)

    Yoon, Donghoon; Okhotin, David V.; Kim, Bumjun; Okhotina, Yulia; Okhotin, Daniel J.; Miasnikova, Galina Y.; Sergueeva, Adelina I.; Polyakova, Lydia A.; Maslow, Alexei; Lee, Yonggu; Semenza, Gregg L.; Prchal, Josef T.

    2010-01-01

    Chuvash polycythemia, the first hereditary disease associated with dysregulated oxygen-sensing to be recognized, is characterized by a homozygous germ-line loss-of-function mutation of the VHL gene (VHLR200W) resulting in elevated hypoxia inducible factor (HIF)-1α and HIF-2α levels, increased red cell mass and propensity to thrombosis. Organ volume is determined by the size and number of cells, and the underlying molecular control mechanisms are not fully elucidated. Work from several groups has demonstrated that the proliferation of cells is regulated in opposite directions by HIF-1α and HIF-2α. HIF-1α inhibits cell proliferation by displacing MYC from the promoter of the gene encoding the cyclin-dependent kinase inhibitor, p21Cip1, thereby inducing its expression. In contrast, HIF-2α promotes MYC activity and cell proliferation. Here we report that the volumes of liver, spleen, and kidneys relative to body mass were larger in 30 individuals with Chuvash polycythemia than in 30 matched Chuvash controls. In Hif1a+/− mice, which are heterozygous for a null (knockout) allele at the locus encoding HIF-1α, hepatic HIF-2α mRNA was increased (2-fold) and the mass of the liver was increased, compared with wild-type littermates, without significant difference in cell volume. Hepatic p21Cip1 mRNA levels were 9.5-fold lower in Hif1a+/− mice compared with wild-type littermates. These data suggest that, in addition to increased red cell mass, the sizes of liver, spleen, and kidneys are increased in Chuvash polycythemia. At least in the liver, this phenotype may result from increased HIF-2α and decreased p21Cip1 levels leading to increased hepatocyte proliferation. PMID:20140661

  15. Growth inhibition induced by antiprogestins RU-38486, ORG-31710, and CDB-2914 in ovarian cancer cells involves inhibition of cyclin dependent kinase 2.

    Science.gov (United States)

    Goyeneche, Alicia A; Seidel, Erin E; Telleria, Carlos M

    2012-06-01

    Antiprogestins have been largely utilized in reproductive medicine, yet their repositioning for oncologic use is rapidly emerging. In this study we investigated the molecular mediators of the anti-ovarian cancer activity of the structurally related antiprogestins RU-38486, ORG-31710 and CDB-2914. We studied the responses of wt p53 OV2008 and p53 null SK-OV-3 cells to varying doses of RU-38486, ORG-31710 and CDB-2914. The steroids inhibited the growth of both cell lines with a potency of RU-38486 > ORG-31710 > CDB-2914, and were cytostatic at lower doses but lethal at higher concentrations. Antiprogestin-induced lethality associated with morphological features of apoptosis, hypodiploid DNA content, DNA fragmentation, and cleavage of executer caspase substrate PARP. Cell death ensued despite RU-38486 caused transient up-regulation of anti-apoptotic Bcl-2, ORG-31710 induced transient up-regulation of inhibitor of apoptosis XIAP, and CDB-2914 up-regulated both XIAP and Bcl-2. The antiprogestins induced accumulation of Cdk inhibitors p21(cip1) and p27(kip1) and increased association of p21(cip1) and p27(kip1) with Cdk-2. They also promoted nuclear localization of p21(cip1) and p27(kip1), reduced the nuclear abundances of Cdk-2 and cyclin E, and blocked the activity of Cdk-2 in both nucleus and cytoplasm. The cytotoxic potency of the antiprogestins correlated with the magnitude of the inhibition of Cdk-2 activity, ranging from G1 cell cycle arrest towards cell death. Our results suggest that, as a consequence of their cytostatic and lethal effects, antiprogestin steroids of well-known contraceptive properties emerge as attractive new agents to be repositioned for ovarian cancer therapeutics.

  16. Mechanisms of Diabetes-Induced Endothelial Cell Senescence: Role of Arginase 1

    Directory of Open Access Journals (Sweden)

    Esraa Shosha

    2018-04-01

    Full Text Available We have recently found that diabetes-induced premature senescence of retinal endothelial cells is accompanied by NOX2-NADPH oxidase-induced increases in the ureohydrolase enzyme arginase 1 (A1. Here, we used genetic strategies to determine the specific involvement of A1 in diabetes-induced endothelial cell senescence. We used A1 knockout mice and wild type mice that were rendered diabetic with streptozotocin and retinal endothelial cells (ECs exposed to high glucose or transduced with adenovirus to overexpress A1 for these experiments. ABH [2(S-Amino-6-boronohexanoic acid] was used to inhibit arginase activity. We used Western blotting, immunolabeling, quantitative PCR, and senescence associated β-galactosidase (SA β-Gal activity to evaluate senescence. Analyses of retinal tissue extracts from diabetic mice showed significant increases in mRNA expression of the senescence-related proteins p16INK4a, p21, and p53 when compared with non-diabetic mice. SA β-Gal activity and p16INK4a immunoreactivity were also increased in retinal vessels from diabetic mice. A1 gene deletion or pharmacological inhibition protected against the induction of premature senescence. A1 overexpression or high glucose treatment increased SA β-Gal activity in cultured ECs. These results demonstrate that A1 is critically involved in diabetes-induced senescence of retinal ECs. Inhibition of arginase activity may therefore be an effective therapeutic strategy to alleviate diabetic retinopathy by preventing premature senescence.

  17. Use of human tissue to assess the oncogenic activity of melanoma-associated mutations.

    Science.gov (United States)

    Chudnovsky, Yakov; Adams, Amy E; Robbins, Paul B; Lin, Qun; Khavari, Paul A

    2005-07-01

    Multiple genetic alterations occur in melanoma, a lethal skin malignancy of increasing incidence. These include mutations that activate Ras and two of its effector cascades, Raf and phosphoinositide 3-kinase (PI3K). Induction of Ras and Raf can be caused by active N-Ras and B-Raf mutants as well as by gene amplification. Activation of PI3K pathway components occurs by PTEN loss and by AKT3 amplification. Melanomas also commonly show impairment of the p16(INK4A)-CDK4-Rb and ARF-HDM2-p53 tumor suppressor pathways. CDKN2A mutations can produce p16(INK4A) and ARF protein loss. Rb bypass can also occur through activating CDK4 mutations as well as by CDK4 amplification. In addition to ARF deletion, p53 pathway disruption can result from dominant negative TP53 mutations. TERT amplification also occurs in melanoma. The extent to which these mutations can induce human melanocytic neoplasia is unknown. Here we characterize pathways sufficient to generate human melanocytic neoplasia and show that genetically altered human tissue facilitates functional analysis of mutations observed in human tumors.

  18. Towards a Better Understanding of the Molecular Mechanisms Involved in Sunlight-Induced Melanoma

    Directory of Open Access Journals (Sweden)

    Williams Mandy

    2005-01-01

    Full Text Available Although much less prevalent than its nonmelanoma skin cancer counterparts, cutaneous malignant melanoma (CMM is the most lethal human skin cancer. Epidemiological and biological studies have established a strong link between lifetime exposure to ultraviolet (UV light, particularly sunburn in childhood, and the development of melanoma. However, the specific molecular targets of this environmental carcinogen are not known. Data obtained from genetic and molecular studies over the last few years have identified the INK4a/ARF locus as the “gatekeeper” melanoma suppressor, encoding two tumour suppressor proteins in human, p16 INK4a and p14 ARF . Recent developments in molecular biotechnology and research using laboratory animals have made a significant gene breakthrough identifying the components of the p16 INK4a /Rb pathway as the principal and rate-limiting targets of UV radiation actions in melanoma formation. This review summarizes the current knowledge of the molecular mechanisms involved in melanoma development and its relationship to sunlight UV radiation.

  19. Low prevalence of human papillomavirus in oral cavity squamous cell carcinoma in Queensland, Australia.

    Science.gov (United States)

    Emmett, Sarah; Jenkins, Glenn; Boros, Samuel; Whiteman, David C; Panizza, Benedict; Antonsson, Annika

    2017-09-01

    While human papillomavirus (HPV) is an accepted risk factor for oropharyngeal squamous cell carcinoma (SCC), its aetiological role in oral cavity SCC remains unclear. This study aimed to determine the HPV prevalence in an Australian population. DNA was extracted from 63 formalin-fixed paraffin-embedded tumour specimens histologically confirmed as SCC of the oral cavity, diagnosed during 2006-2012. Clinical data were extracted from medical records. HPV presence was determined by polymerase chain reaction. Positive samples were typed by sequencing. Immunohistochemistry was used to assess p16 INK4A , p53, pRB, Ki67, Cyclin D1 and p21 WAF1 expression. Five of the 63 tumours (8%) were positive for HPV DNA (three HPV-16 positive and two HPV-18 positive). Two tumours overexpressed p16 INK4A (3%) and one of these was also HPV positive. Overexpression of Cyclin D1 correlated significantly with tumour recurrence (P = 0.029) and death (P = 0.002). This study has identified a low prevalence of high-risk HPV in Queensland, Australia. © 2016 Royal Australasian College of Surgeons.

  20. NONO couples the circadian clock to the cell cycle.

    Science.gov (United States)

    Kowalska, Elzbieta; Ripperger, Juergen A; Hoegger, Dominik C; Bruegger, Pascal; Buch, Thorsten; Birchler, Thomas; Mueller, Anke; Albrecht, Urs; Contaldo, Claudio; Brown, Steven A

    2013-01-29

    Mammalian circadian clocks restrict cell proliferation to defined time windows, but the mechanism and consequences of this interrelationship are not fully understood. Previously we identified the multifunctional nuclear protein NONO as a partner of circadian PERIOD (PER) proteins. Here we show that it also conveys circadian gating to the cell cycle, a connection surprisingly important for wound healing in mice. Specifically, although fibroblasts from NONO-deficient mice showed approximately normal circadian cycles, they displayed elevated cell doubling and lower cellular senescence. At a molecular level, NONO bound to the p16-Ink4A cell cycle checkpoint gene and potentiated its circadian activation in a PER protein-dependent fashion. Loss of either NONO or PER abolished this activation and circadian expression of p16-Ink4A and eliminated circadian cell cycle gating. In vivo, lack of NONO resulted in defective wound repair. Because wound healing defects were also seen in multiple circadian clock-deficient mouse lines, our results therefore suggest that coupling of the cell cycle to the circadian clock via NONO may be useful to segregate in temporal fashion cell proliferation from tissue organization.

  1. The role of human papillomavirus in head and neck cancer in Senegal.

    Science.gov (United States)

    Ndiaye, Cathy; Alemany, Laia; Diop, Yankhoba; Ndiaye, Nafissatou; Diémé, Marie-Joseph; Tous, Sara; Klaustermeier, Jo Ellen; Alejo, Maria; Castellsagué, Xavier; Bosch, F Xavier; Trottier, Helen; Sanjosé, Silvia de

    2013-04-17

    Exploring the presence and role of human papillomavirus (HPV) in head and neck cancer (HNC) is a necessary step to evaluate the potential impact of HPV prophylactic vaccines. To assess the prevalence and oncogenic role of HPV in HNC in Senegal. This is a multicenter cross-sectional study. Paraffin-embedded blocks of cases diagnosed with invasive HNC between 2002 and 2010 were collected from 4 pathology laboratories in Senegal. Presence of HPV DNA was determined by PCR and DEIA, and genotyping performed with LiPA25. Tubulin analysis was performed to assess DNA quality. HPV DNA-positive cases were tested for p16INK4a expression. A total of 117 cases were included in the analysis: 71% were men, mean age was 52 years old (SD ±18.3), and 96% of cases were squamous cell carcinoma. Analysis was performed on 41 oral cavity tumors, 64 laryngeal tumors, 5 oropharyngeal tumors and 7 pharyngeal tumors. Only four cases (3.4%; 95% CI = 0.9%-8.5%) harbored HPV DNA. HPV types detected were HPV16, HPV35 and HPV45. However, among HPV-positive cases, none showed p16INK4a overexpression. Our findings indicate that HPV DNA prevalence in HNC in Senegal is very low, suggesting that HPV is not a strong risk factor for these cancers. Additional larger studies are needed to confirm these findings and explore other potential risk factors specific to the region.

  2. Cell survival, cell death and cell cycle pathways are interconnected: Implications for cancer therapy

    DEFF Research Database (Denmark)

    Maddika, S; Ande, SR; Panigrahi, S

    2007-01-01

    )), and the Cip1/Waf1/Kip1-2-family (p21(Cip1/Waf1), p27(Kip1), p57(Kip2)) are shown both in the context of proliferation regulators and as contributors to the apoptotic machinery. Bcl2-family members (i.e. Bcl2, Bcl-X(L) Mcl-1(L); Bax, Bok/Mtd, Bak, and Bcl-X(S); Bad, Bid, Bim(EL), Bmf, Mcl-1(S)) are highlighted...... approaches that would involve redirecting over-active survival and proliferation pathways towards induction of apoptosis in cancer cells....

  3. Evaluation of Androgen Receptor Function in Prostate Cancer Prognosis and Therapeutic Stratification

    Science.gov (United States)

    2015-12-01

    evaluated for DNA meth - ylation. Patient matched non-adjacent normal epithelial cells Figure 1. (A) schematic representation of the PMEPA1 gene structure...reduced or lost expression of PMEPA1 in CaP. The results presented here demonstrate that promoter meth - ylation is a major mechanism involved in...c-Myc-p21 Cip1 signaling pathway. J Pathol 2011; 223:683- 94; PMID:21341270; http://dx.doi.org/10.1002/ path.2834 21. Richter E, Masuda K, Cook C

  4. The KRAB Zinc Finger Protein Roma/Zfp157 Is a Critical Regulator of Cell-Cycle Progression and Genomic Stability

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    Teresa L.F. Ho

    2016-04-01

    Full Text Available Regulation of DNA replication and cell division is essential for tissue growth and maintenance of genomic integrity and is particularly important in tissues that undergo continuous regeneration such as mammary glands. We have previously shown that disruption of the KRAB-domain zinc finger protein Roma/Zfp157 results in hyperproliferation of mammary epithelial cells (MECs during pregnancy. Here, we delineate the mechanism by which Roma engenders this phenotype. Ablation of Roma in MECs leads to unscheduled proliferation, replication stress, DNA damage, and genomic instability. Furthermore, mouse embryonic fibroblasts (MEFs depleted for Roma exhibit downregulation of p21Cip1 and geminin and have accelerated replication fork velocities, which is accompanied by a high rate of mitotic errors and polyploidy. In contrast, overexpression of Roma in MECs halts cell-cycle progression, whereas siRNA-mediated p21Cip1 knockdown ameliorates, in part, this phenotype. Thus, Roma is an essential regulator of the cell cycle and is required to maintain genomic stability.

  5. A synthetic peptide derived from alpha-fetoprotein inhibits the estradiol-induced proliferation of mammary tumor cells in culture through the modulation of p21.

    Science.gov (United States)

    Sierralta, Walter D; Epuñan, María J; Reyes, José M; Valladares, Luis E; Pino, Ana M

    2008-01-01

    A stable cyclized 9-mer peptide (cP) containing the active site of alpha-alpha fetoprotein (alphaFP) has been shown to be effective for prevention of estrogen-stimulated tumor cell proliferation in culture or of xenographt growth in immunodeficient mice. cP does not block 17beta-estradiol (E2) binding to its receptors, but rather appears to interfere with intracellular processing of the signal that supports growth. To obtain insight on that mechanism we studied the effect of cP on the proliferation of MCF-7 cells in culture. Proliferation in the presence of 2 microM E2 is decreased up to 40% upon addition of 2 microg ml(-1) cP to the medium; the presence of cP did not increase cell death, cP reduced also the proliferation of estrogen-dependent ZR75-1 cells but had no effect on autonomous MDA-MB-231 cells, cP did not modify the number of binding sites for labeled E2 or affected cell death. We detected increased nuclear p21Cip1 immunoreactivity after cP treatment. Our results suggest that cP acts via p21Cip1 to slow the process of MCF-7 cells through the cycle.

  6. A peptide derived from alpha-fetoprotein inhibits the proliferation induced by estradiol in mammary tumor cells in culture.

    Science.gov (United States)

    Sierralta, Walter D; Epuñan, Maria J; Reyes, José M; Valladares, Luis E; Andersen, Thomas T; Bennett, James A; Jacobson, Herbert I; Pino, Ana M

    2008-01-01

    This study was aimed to obtain additional information on the activity of a cyclized 9-amino acid peptide (cP) containing the active site of alpha fetoprotein, which inhibits the estrogen-stimulated proliferation of tumor cells in culture and of xenografts in immunodeficient mice. Breast cancer cells cultured in the presence of 2 nM estradiol were exposed to cP for different periods and their proliferation, estradiol binding parameters, clustering tendency and expression of E-cadherin and p21Cip1 were analyzed by biochemical and cell biology methods. The proliferation of MCF7 cells was significantly decreased by the addition of 2 microg/ml cP to the medium. cP did not increase cell death rate nor alter the number of binding sites for estradiol nor the endogenous aromatase activity of MCF7 cells. cP also decreased the proliferation of estrogen-dependent ZR75-1 cells but had no effect on estrogen-independent MDA-MB-231 cells. An increased nuclear p21Cip1 expression detected after cP treatment suggests that cP slows MCF7 cell proliferation via this regulator. We propose that cP could represent a novel breast cancer therapeutic agent whose mechanism of action is different from that of tamoxifen or of inhibitors of aromatase.

  7. HDAC inhibitor L-carnitine and proteasome inhibitor bortezomib synergistically exert anti-tumor activity in vitro and in vivo.

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    Hongbiao Huang

    Full Text Available Combinations of proteasome inhibitors and histone deacetylases (HDAC inhibitors appear to be the most potent to produce synergistic cytotoxicity in preclinical trials. We have recently confirmed that L-carnitine (LC is an endogenous HDAC inhibitor. In the current study, the anti-tumor effect of LC plus proteasome inhibitor bortezomib (velcade, Vel was investigated both in cultured hepatoma cancer cells and in Balb/c mice bearing HepG2 tumor. Cell death and cell viability were assayed by flow cytometry and MTS, respectively. Gene, mRNA expression and protein levels were detected by gene microarray, quantitative real-time PCR and Western blot, respectively. The effect of Vel on the acetylation of histone H3 associated with the p21(cip1 gene promoter was examined by using ChIP assay and proteasome peptidase activity was detected by cell-based chymotrypsin-like (CT-like activity assay. Here we report that (i the combination of LC and Vel synergistically induces cytotoxicity in vitro; (ii the combination also synergistically inhibits tumor growth in vivo; (iii two major pathways are involved in the synergistical effects of the combinational treatment: increased p21(cip1 expression and histone acetylation in vitro and in vivo and enhanced Vel-induced proteasome inhibition by LC. The synergistic effect of LC and Vel in cancer therapy should have great potential in the future clinical trials.

  8. Heregulin Co-opts PR Transcriptional Action Via Stat3 Role As a Coregulator to Drive Cancer Growth.

    Science.gov (United States)

    Proietti, Cecilia J; Izzo, Franco; Díaz Flaqué, María Celeste; Cordo Russo, Rosalía; Venturutti, Leandro; Mercogliano, María Florencia; De Martino, Mara; Pineda, Viviana; Muñoz, Sergio; Guzmán, Pablo; Roa, Juan C; Schillaci, Roxana; Elizalde, Patricia V

    2015-10-01

    Accumulated findings have demonstrated the presence of bidirectional interactions between progesterone receptor (PR) and the ErbB family of receptor tyrosine kinases signaling pathways in breast cancer. We previously revealed signal transducer and activator of transcription 3 (Stat3) as a nodal convergence point between said signaling pathways proving that Stat3 is activated by one of the ErbBs' ligands, heregulin (HRG)β1 via ErbB2 and through the co-option of PR as a signaling molecule. Here, we found that HRGβ1 induced Stat3 recruitment to the promoters of the progestin-regulated cell cycle modulators Bcl-XL and p21(CIP1) and also stimulated Stat3 binding to the mouse mammary tumor virus promoter, which carries consensus progesterone response elements. Interestingly, HRGβ1-activated Stat3 displayed differential functions on PR activity depending on the promoter bound. Indeed, Stat3 was required for PR binding in bcl-X, p21(CIP1), and c-myc promoters while exerting a PR coactivator function on the mouse mammary tumor virus promoter. Stat3 also proved to be necessary for HRGβ1-induced in vivo tumor growth. Our results endow Stat3 a novel function as a coregulator of HRGβ1-activated PR to promote breast cancer growth. These findings underscore the importance of understanding the complex interactions between PR and other regulatory factors, such as Stat3, that contribute to determine the context-dependent transcriptional actions of PR.

  9. Curcumin Protects against UVB-Induced Skin Cancers in SKH-1 Hairless Mouse: Analysis of Early Molecular Markers in Carcinogenesis

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    Kuen-Daw Tsai

    2012-01-01

    Full Text Available Curcumin (CUR has been shown to possess a preventive effect against various cancers and interfere with multiple-cell signaling pathways. We evaluated the protective effects of CUR in regression of UVB-induced skin tumor formation in SKH-1 hairless mice and its underlying early molecular biomarkers associated with carcinogenesis. Mice irradiated with UVB at 180 mJ/cm2 twice per week elicited 100% tumor incidence at 20 weeks. Topical application of CUR prior to UVB irradiation caused delay in tumor appearance, multiplicity, and size. Topical application of CUR prior to and immediately after a single UVB irradiation (180 mJ/cm2 resulted in a significant decrease in UVB-induced thymine dimer-positive cells, expression of proliferative cell nuclear antigen (PCNA, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling, and apoptotic sunburn cells together with an increase in p53 and p21/Cip1-positive cell population in epidermis. Simultaneously, CUR also significantly inhibited NF-κB, cyclooxygenase-2 (COX-2, prostaglandin E2 (PGE2, and nitric oxide (NO levels. The results suggest that the protective effect of CUR against photocarcinogenesis is accompanied by downregulation of cell proliferative controls, involving thymine dimer, PCNA, apoptosis, transcription factors NF-κB, and of inflammatory responses involving COX-2, PGE2, and NO, while upregulation of p53 and p21/Cip1 to prevent DNA damage and facilitate DNA repair.

  10. Synemin promotes AKT-dependent glioblastoma cell proliferation by antagonizing PP2A.

    Science.gov (United States)

    Pitre, Aaron; Davis, Nathan; Paul, Madhumita; Orr, A Wayne; Skalli, Omar

    2012-04-01

    The intermediate filament protein synemin is present in astrocyte progenitors and glioblastoma cells but not in mature astrocytes. Here we demonstrate a role for synemin in enhancing glioblastoma cell proliferation and clonogenic survival, as synemin RNA interference decreased both behaviors by inducing G1 arrest along with Rb hypophosphorylation and increased protein levels of the G1/S inhibitors p21(Cip1) and p27(Kip1). Akt involvement was demonstrated by decreased phosphorylation of its substrate, p21(Cip1), and reduced Akt catalytic activity and phosphorylation at essential activation sites. Synemin silencing, however, did not affect the activities of PDPK1 and mTOR complex 2, which directly phosphorylate Akt activation sites, but instead enhanced the activity of the major regulator of Akt dephosphorylation, protein phosphatase type 2A (PP2A). This was accompanied by changes in PP2A subcellular distribution resulting in increased physical interactions between PP2A and Akt, as shown by proximity ligation assays (PLAs). PLAs and immunoprecipitation experiments further revealed that synemin and PP2A form a protein complex. In addition, treatment of synemin-silenced cells with the PP2A inhibitor cantharidic acid resulted in proliferation and pAkt and pRb levels similar to those of controls. Collectively these results indicate that synemin positively regulates glioblastoma cell proliferation by helping sequester PP2A away from Akt, thereby favoring Akt activation.

  11. CDK2 differentially controls normal cell senescence and cancer cell proliferation upon exposure to reactive oxygen species

    International Nuclear Information System (INIS)

    Hwang, Chae Young; Lee, Seung-Min; Park, Sung Sup; Kwon, Ki-Sun

    2012-01-01

    Highlights: ► H 2 O 2 differently adjusted senescence and proliferation in normal and cancer cells. ► H 2 O 2 exposure transiently decreased PCNA levels in normal cells. ► H 2 O 2 exposure transiently increased CDK2 activity in cancer cells. ► p21 Cip1 is likely dispensable when H 2 O 2 induces senescence in normal cells. ► Suggestively, CDK2 and PCNA play critical roles in H 2 O 2 -induced cell fate decision. -- Abstract: Reactive oxygen species modulate cell fate in a context-dependent manner. Sublethal doses of H 2 O 2 decreased the level of proliferating cell nuclear antigen (PCNA) in normal cells (including primary human dermal fibroblasts and IMR-90 cells) without affecting cyclin-dependent kinase 2 (CDK2) activity, leading to cell cycle arrest and subsequent senescence. In contrast, exposure of cancer cells (such as HeLa and MCF7 cells) to H 2 O 2 increased CDK2 activity with no accompanying change in the PCNA level, leading to cell proliferation. A CDK2 inhibitor, CVT-313, prevented H 2 O 2 -induced cancer cell proliferation. These results support the notion that the cyclin/CDK2/p21 Cip1 /PCNA complex plays an important role as a regulator of cell fate decisions.

  12. Loss of p53 induces cell proliferation via Ras-independent activation of the Raf/Mek/Erk signaling pathway

    Science.gov (United States)

    Drosten, Matthias; Sum, Eleanor Y. M.; Lechuga, Carmen G.; Simón-Carrasco, Lucía; Jacob, Harrys K. C.; García-Medina, Raquel; Huang, Sidong; Beijersbergen, Roderick L.; Bernards, Rene; Barbacid, Mariano

    2014-01-01

    The Ras family of small GTPases constitutes a central node in the transmission of mitogenic stimuli to the cell cycle machinery. The ultimate receptor of these mitogenic signals is the retinoblastoma (Rb) family of pocket proteins, whose inactivation is a required step to license cell proliferation. However, little is known regarding the molecular events that connect Ras signaling with the cell cycle. Here, we provide genetic evidence to illustrate that the p53/p21 Cdk-interacting protein 1 (Cip1)/Rb axis is an essential component of the Ras signaling pathway. Indeed, knockdown of p53, p21Cip1, or Rb restores proliferative properties in cells arrested by ablation of the three Ras loci, H-, N- and K-Ras. Ras signaling selectively inactivates p53-mediated induction of p21Cip1 expression by inhibiting acetylation of specific lysine residues in the p53 DNA binding domain. Proliferation of cells lacking both Ras proteins and p53 can be prevented by reexpression of the human p53 ortholog, provided that it retains an active DNA binding domain and an intact lysine residue at position 164. These results unveil a previously unidentified role for p53 in preventing cell proliferation under unfavorable mitogenic conditions. Moreover, we provide evidence that cells lacking Ras and p53 proteins owe their proliferative properties to the unexpected retroactivation of the Raf/Mek/Erk cascade by a Ras-independent mechanism. PMID:25288756

  13. The vitamin-like dietary supplement para-aminobenzoic acid enhances the antitumor activity of ionizing radiation

    International Nuclear Information System (INIS)

    Xavier, Sandhya; MacDonald, Shannon; Roth, Jennifer; Caunt, Maresa; Akalu, Abebe; Morais, Danielle; Buckley, Michael T.; Liebes, Leonard; Formenti, Silvia C.; Brooks, Peter C.

    2006-01-01

    Purpose: To determine whether para-aminobenzoic acid (PABA) alters the sensitivity of tumor cells to ionizing radiation in vitro and in vivo. Methods and Materials: Cellular proliferation was assessed by WST-1 assays. The effects of PABA and radiation on tumor growth were examined with chick embryo and murine models. Real-time reverse transcriptase-polymerase chain reaction and Western blotting were used to quantify p21 CIP1 and CDC25A levels. Results: Para-aminobenzoic acid enhanced (by 50%) the growth inhibitory activity of radiation on B16F10 cells, whereas it had no effect on melanocytes. Para-aminobenzoic acid enhanced (50-80%) the antitumor activity of radiation on B16F10 and 4T1 tumors in vivo. The combination of PABA and radiation therapy increased tumor apoptosis. Treatment of tumor cells with PABA increased expression of CDC25A and decreased levels of p21 CIP1 . Conclusions: Our findings suggest that PABA might represent a compound capable of enhancing the antitumor activity of ionizing radiation by a mechanism involving altered expression of proteins known to regulate cell cycle arrest

  14. Heregulin Co-opts PR Transcriptional Action Via Stat3 Role As a Coregulator to Drive Cancer Growth

    Science.gov (United States)

    Izzo, Franco; Díaz Flaqué, María Celeste; Cordo Russo, Rosalía; Venturutti, Leandro; Mercogliano, María Florencia; De Martino, Mara; Pineda, Viviana; Muñoz, Sergio; Guzmán, Pablo; Roa, Juan C.; Schillaci, Roxana

    2015-01-01

    Accumulated findings have demonstrated the presence of bidirectional interactions between progesterone receptor (PR) and the ErbB family of receptor tyrosine kinases signaling pathways in breast cancer. We previously revealed signal transducer and activator of transcription 3 (Stat3) as a nodal convergence point between said signaling pathways proving that Stat3 is activated by one of the ErbBs' ligands, heregulin (HRG)β1 via ErbB2 and through the co-option of PR as a signaling molecule. Here, we found that HRGβ1 induced Stat3 recruitment to the promoters of the progestin-regulated cell cycle modulators Bcl-XL and p21CIP1 and also stimulated Stat3 binding to the mouse mammary tumor virus promoter, which carries consensus progesterone response elements. Interestingly, HRGβ1-activated Stat3 displayed differential functions on PR activity depending on the promoter bound. Indeed, Stat3 was required for PR binding in bcl-X, p21CIP1, and c-myc promoters while exerting a PR coactivator function on the mouse mammary tumor virus promoter. Stat3 also proved to be necessary for HRGβ1-induced in vivo tumor growth. Our results endow Stat3 a novel function as a coregulator of HRGβ1-activated PR to promote breast cancer growth. These findings underscore the importance of understanding the complex interactions between PR and other regulatory factors, such as Stat3, that contribute to determine the context-dependent transcriptional actions of PR. PMID:26340407

  15. Morphoproteomics, E6/E7 in-situ hybridization, and biomedical analytics define the etiopathogenesis of HPV-associated oropharyngeal carcinoma and provide targeted therapeutic options.

    Science.gov (United States)

    Brown, Robert E; Naqvi, Syed; McGuire, Mary F; Buryanek, Jamie; Karni, Ron J

    2017-08-17

    Human papillomavirus (HPV) has been identified as an etiopathogenetic factor in oropharyngeal squamous cell carcinoma. The HPV E6 and E7 oncogenes are instrumental in promoting proliferation and blocking differentiation leading to tumorigenesis. Although surgical intervention can remove such tumors, the potential for an etiologic field effect with recurrent disease is real. A downstream effector of E7 oncoprotein, enhancer of zeste homolog 2 (EZH2), is known to promote proliferation and to pose a block in differentiation and in turn, could lead to HPV-induced malignant transformation. However, the EZH2 pathway is amenable to low toxicity therapies designed to promote differentiation to a more benign state and prevent recurrent disease by inhibiting the incorporation of HPV into the genome. This is the first study using clinical specimens to demonstrate EZH2 protein expression in oropharyngeal carcinoma (OPC). The study included eight patients with oropharyngeal carcinoma, confirmed p16INK4a- positive by immunohistochemistry (IHC). The tissue expression of E6/E7 messenger RNA (mRNA) was measured by RNAscope® in-situ hybridization technology. Expression of EZH2, Ki-67, and mitotic indices were assessed by morphoproteomic analysis. Biomedical analytics expanded the results with data from Ingenuity Pathway Analysis (IPA) and KEGG databases to construct a molecular network pathway for further insights. Expression of E6 and E7 oncogenes in p16INK4a- positive oropharyngeal carcinoma was confirmed. EZH2 and its correlates, including elevated proliferation index (Ki-67) and mitotic progression were also present. Biomedical analytics validated the relationship between HPV- E6 and E7 and the expression of the EZH2 pathway. There is morphoproteomic and mRNA evidence of the association of p16INK4a-HPV infection with the E6 and E7 oncogenes and the expression of EZH2, Ki-67 and mitotic progression in oropharyngeal carcinoma. The molecular network biology was confirmed by

  16. The oncoprotein and stem cell renewal factor BMI1 associates with poor clinical outcome in oesophageal cancer patients undergoing preoperative chemoradiotherapy

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    Yoshikawa Reigetsu

    2012-10-01

    Full Text Available Abstract Background The polycomb group (PcG family BMI1, acting downstream of the hedgehog (Hh pathway, plays an essential role in the self-renewal of haematopoietic, neural, and intestinal stem cells, and is dysregulated in many types of cancer. Our recent report has demonstrated that Hh signalling activation can predict very earlier relapse of oesophageal cancers. As data were not available on the clinical role of BMI1 expression in oesophageal cancers after chemoradiotherapy (CRT, we analysed whether it could be also used to predict disease progression and prognosis in oesophageal cancer patients undergoing trimodality therapy of preoperative CRT and oesophagectomy. Methods Expressions of BMI1 and p16INK4A, a downstream target of PcG, were analysed in 78 patients with histologically confirmed oesophageal squamous cell carcinoma (ESCC after preoperative CRT by immunohistochemical staining. The association of BMI1 and p16INK4A expression with clinicopathologic characteristics was analysed by χ2-test. Survival analysis was carried out by the log-rank test using Kaplan-Meier method. Results Among 78 ESCC patients, 24 patients (30.8% showed BMI1 positivity, mainly localised in the nuclei of tumour cells. Patients harbouring BMI1-positive tumour cells showed significantly poorer prognoses than those without such cells or residual tumours (mean disease-free survival (DFS time 16.8 vs 71.2 months; 3-yr DFS 13.3% vs 49.9%, P=0.002; mean OS time 21.8 vs 76.6 months; 3-yr OS 16.2% vs 54.9%, P=0.0005. There was no significant correlation between p16INK4A expression and BMI1 expression. Conclusions Our study shows that BMI1 expression is a predictor of early relapse and poor prognosis in ESCC after CRT. These findings suggest that BMI1 signal activation might be involved in promoting cancer regrowth and progression after CRT, and might be indicative of emergence of ‘more aggressive’ cancer progenitor cells.

  17. Dysregulated ΔNp63α inhibits expression of Ink4a/arf, blocks senescence, and promotes malignant conversion of keratinocytes.

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    Linan Ha

    Full Text Available p63 is critical for squamous epithelial development, and elevated levels of the ΔNp63α isoform are seen in squamous cell cancers of various organ sites. However, significant controversy exists regarding the role of p63 isoforms as oncoproteins or tumor suppressors. Here, lentiviruses were developed to drive long-term overexpression of ΔNp63α in primary keratinocytes. Elevated levels of ΔNp63α in vitro promote long-term survival and block both replicative and oncogene-induced senescence in primary keratinocytes, as evidenced by the expression of SA-β-gal and the presence of nuclear foci of heterochromatin protein 1γ. The contribution of ΔNp63α to cancer development was assessed using an in vivo grafting model of experimental skin tumorigenesis that allows distinction between benign and malignant tumors. Grafted lenti-ΔNp63α keratinocytes do not form tumors, whereas lenti-GFP/v-ras(Ha keratinocytes develop well-differentiated papillomas. Lenti-ΔNp63α/v-ras(Ha keratinocytes form undifferentiated carcinomas. The average volume of lenti-ΔNp63α/v-ras(Ha tumors was significantly higher than those in the lenti-GFP/v-ras(Ha group, consistent with increased BrdU incorporation detected by immunohistochemistry. The block in oncogene-induced senescence corresponds to sustained levels of E2F1 and phosphorylated AKT, and is associated with loss of induction of p16(ink4a/p19(arf. The relevance of p16(ink4a/p19(arf loss was demonstrated in grafting studies of p19(arf-null keratinocytes, which develop malignant carcinomas in the presence of v-ras(Ha similar to those arising in wildtype keratinocytes that express lenti-ΔNp63α and v-ras(Ha. Our findings establish that ΔNp63α has oncogenic activity and its overexpression in human squamous cell carcinomas contributes to the malignant phenotype, and implicate its ability to regulate p16(ink4a/p19(arf in the process.

  18. Spontaneously immortalised bovine mammary epithelial cells exhibit a distinct gene expression pattern from the breast cancer cells

    Directory of Open Access Journals (Sweden)

    Li Qianqian

    2010-10-01

    Full Text Available Abstract Background Spontaneous immortalisation of cultured mammary epithelial cells (MECs is an extremely rare event, and the molecular mechanism behind spontaneous immortalisation of MECs is unclear. Here, we report the establishment of a spontaneously immortalised bovine mammary epithelial cell line (BME65Cs and the changes in gene expression associated with BME65Cs cells. Results BME65Cs cells maintain the general characteristics of normal mammary epithelial cells in morphology, karyotype and immunohistochemistry, and are accompanied by the activation of endogenous bTERT (bovine Telomerase Reverse Transcriptase and stabilisation of the telomere. Currently, BME65Cs cells have been passed for more than 220 generations, and these cells exhibit non-malignant transformation. The expression of multiple genes was investigated in BME65Cs cells, senescent BMECs (bovine MECs cells, early passage BMECs cells and MCF-7 cells (a human breast cancer cell line. In comparison with early passage BMECs cells, the expression of senescence-relevant apoptosis-related gene were significantly changed in BME65Cs cells. P16INK4a was downregulated, p53 was low expressed and Bax/Bcl-2 ratio was reversed. Moreover, a slight upregulation of the oncogene c-Myc, along with an undetectable level of breast tumor-related gene Bag-1 and TRPS-1, was observed in BME65Cs cells while these genes are all highly expressed in MCF-7. In addition, DNMT1 is upregulated in BME65Cs. These results suggest that the inhibition of both senescence and mitochondrial apoptosis signalling pathways contribute to the immortality of BME65Cs cells. The expression of p53 and p16INK4a in BME65Cs was altered in the pattern of down-regulation but not "loss", suggesting that this spontaneous immortalization is possibly initiated by other mechanism rather than gene mutation of p53 or p16INK4a. Conclusions Spontaneously immortalised BME65Cs cells maintain many characteristics of normal BMEC cells and

  19. Immortalization of normal human embryonic fibroblasts by introduction of either the human papillomavirus type 16 E6 or E7 gene alone.

    Science.gov (United States)

    Yamamoto, Akito; Kumakura, Shin-ichi; Uchida, Minoru; Barrett, J Carl; Tsutsui, Takeki

    2003-09-01

    The ability of the human papillomavirus type 16 (HPV-16) E6 or E7 gene to induce immortalization of normal human embryonic fibroblast WHE-7 cells was examined. WHE-7 cells at 9 population doublings (PD) were infected with retrovirus vectors encoding either HPV-16 E6 or E7 alone or both E6 and E7 (E6/E7). One of 4 isolated clones carrying E6 alone became immortal and is currently at >445 PD. Four of 4 isolated clones carrying E7 alone escaped from crisis and are currently at >330 PD. Three of 5 isolated clones carrying E6/E7 were also immortalized and are currently at >268 PD. The immortal clone carrying E6 only and 2 of the 3 immortal clones carrying E6/E7 expressed a high level of E6 protein, and all the immortal clones carrying E7 alone and the other immortal clone carrying E6/E7 expressed a high level of E7 protein when compared to their mortal or precrisis clones. The immortal clones expressing a high level of E6 or E7 protein were positive for telomerase activity or an alternative mechanism of telomere maintenance, respectively, known as ALT (alternative lengthening of telomeres). All the mortal or precrisis clones were negative for both phenotypes. All the immortal clones exhibited abrogation of G1 arrest after DNA damage by X-ray irradiation. The expression of INK4a protein (p16(INK4a)) was undetectable in the E6-infected mortal and immortal clones, whereas Rb protein (pRb) was hyperphosphorylated only in the immortal clone. The p16(INK4a) protein was overexpressed in all the E7-infected immortal clones and their clones in the pre-crisis period as well as all the E6/E7-infected mortal and immortal clones, but the pRb expression was downregulated in all of these clones. These results demonstrate for the first time to our knowledge that HPV-16 E6 or E7 alone can induce immortalization of normal human embryonic fibroblasts. Inactivation of p16(INK4a)/pRb pathways in combination with activation of a telomere maintenance mechanism is suggested to be necessary for

  20. HPV Involvement in Head and Neck Cancers: Comprehensive Assessment of Biomarkers in 3680 Patients.

    Science.gov (United States)

    Castellsagué, Xavier; Alemany, Laia; Quer, Miquel; Halec, Gordana; Quirós, Beatriz; Tous, Sara; Clavero, Omar; Alòs, Llúcia; Biegner, Thorsten; Szafarowski, Tomasz; Alejo, Maria; Holzinger, Dana; Cadena, Enrique; Claros, Edith; Hall, Gillian; Laco, Jan; Poljak, Mario; Benevolo, Maria; Kasamatsu, Elena; Mehanna, Hisham; Ndiaye, Cathy; Guimerà, Núria; Lloveras, Belen; León, Xavier; Ruiz-Cabezas, Juan C; Alvarado-Cabrero, Isabel; Kang, Chang-Suk; Oh, Jin-Kyoung; Garcia-Rojo, Marcial; Iljazovic, Ermina; Ajayi, Oluseyi F; Duarte, Flora; Nessa, Ashrafun; Tinoco, Leopoldo; Duran-Padilla, Marco A; Pirog, Edyta C; Viarheichyk, Halina; Morales, Hesler; Costes, Valérie; Félix, Ana; Germar, Maria Julieta V; Mena, Marisa; Ruacan, Arzu; Jain, Asha; Mehrotra, Ravi; Goodman, Marc T; Lombardi, Luis Estuardo; Ferrera, Annabelle; Malami, Sani; Albanesi, Estela I; Dabed, Pablo; Molina, Carla; López-Revilla, Rubén; Mandys, Václav; González, Manuel E; Velasco, Julio; Bravo, Ignacio G; Quint, Wim; Pawlita, Michael; Muñoz, Nubia; de Sanjosé, Silvia; Xavier Bosch, F

    2016-06-01

    We conducted a large international study to estimate fractions of head and neck cancers (HNCs) attributable to human papillomavirus (HPV-AFs) using six HPV-related biomarkers of viral detection, transcription, and cellular transformation. Formalin-fixed, paraffin-embedded cancer tissues of the oral cavity (OC), pharynx, and larynx were collected from pathology archives in 29 countries. All samples were subject to histopathological evaluation, DNA quality control, and HPV-DNA detection. Samples containing HPV-DNA were further subject to HPV E6*I mRNA detection and to p16(INK4a), pRb, p53, and Cyclin D1 immunohistochemistry. Final estimates of HPV-AFs were based on HPV-DNA, HPV E6*I mRNA, and/or p16(INK4a) results. A total of 3680 samples yielded valid results: 1374 pharyngeal, 1264 OC, and 1042 laryngeal cancers. HPV-AF estimates based on positivity for HPV-DNA, and for either HPV E6*I mRNA or p16(INK4a), were 22.4%, 4.4%, and 3.5% for cancers of the oropharynx, OC, and larynx, respectively, and 18.5%, 3.0%, and 1.5% when requiring simultaneous positivity for all three markers. HPV16 was largely the most common type. Estimates of HPV-AF in the oropharynx were highest in South America, Central and Eastern Europe, and Northern Europe, and lowest in Southern Europe. Women showed higher HPV-AFs than men for cancers of the oropharynx in Europe and for the larynx in Central-South America. HPV contribution to HNCs is substantial but highly heterogeneous by cancer site, region, and sex. This study, the largest exploring HPV attribution in HNCs, confirms the important role of HPVs in oropharyngeal cancer and drastically downplays the previously reported involvement of HPVs in the other HNCs. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  1. [Inhibitory Effect of Decitabine on Proliferation of MDS-L Cells and Its Mechanism].

    Science.gov (United States)

    Wu, Dong; Zhang, Yao; Zhao, You-Shan; Guo, Juan; Chang, Chun-Kang

    2017-10-01

    To investigate the inhibitory effect of decitabine (DAC) in various dosages on the proliferention of MDS-RAEB cell line MDS-L and its mechanism. LC-MS/MS method was used to test the blood DAC concentration of 2 groups of MDS patients being treated with DAC 20 and 15 mg/m 2 ×5 d. In according to the various blood DAC concentration levels, the MDS-L cells were treated with different DAC dosages for 24, 48, 72 and 96 h, respectively. The CCK-8 method was applied to determine the cell proliferation, the flow cytometry was used to analyze the cell cycle and cell apoptosis changes, the P15 INK4B DNA methylation status was measured by methylation specific PCR using EZ DNA Methylation-Gold Kit. The blood DAC concentration of MDS patients treated with DAC 20 mg/m 2 ×5 d was 174.08±80.15(84.7-311) ng/ml, which was significantly higher than 89.87±32.94(43.2-165)ng/ml for the group treated with 15 mg/m 2 ×5 d (P=0.014). DAC could notably inhibit the proliferation of MDS-L cells, and the effect was in dose- and- time-dependent manner(r=0.786). However, when DAC concentration was ≥0.1 µg/ml, the proliferation inhibition rates were not significantly different between various dosages. After DAC treatment, MDS-L cells in G 1 phase increased notably, while cells in S phase decreased significantly. Also, the P15 INK4B DNA methylation status of MDS-L cells decreased after being treated with DAC for 96 h, but the difference was not significant between various dosages. DAC can significantly suppress MDS-L cell proliferation, block MDS-L cells in G 1 phase and induce the apoptosis at low concentration (0.1-0.2 µg/ml).

  2. p63 expression confers significantly better survival outcomes in high-risk diffuse large B-cell lymphoma and demonstrates p53-like and p53-independent tumor suppressor function

    DEFF Research Database (Denmark)

    Xu-Monette, Zijun Y; Zhang, Shanxiang; Li, Xin

    2016-01-01

    with a pan-p63-monoclonal antibody and correlated it with other clinicopathologic factors and clinical outcomes. p63 expression was observed in 42.5% of DLBCL, did not correlate with p53 levels, but correlated with p21, MDM2, p16INK4A, Ki-67, Bcl-6, IRF4/MUM-1 and CD30 expression, REL gains, and BCL6...... was likely due to the association of p63 expression with high-risk IPI, and potential presence of ∆Np63 isoform in TP63 rearranged patients (a mere speculation). Gene expression profiling suggested that p63 has both overlapping and distinct functions compared with p53, and that p63 and mutated p53 antagonize...

  3. The Polycomb group proteins bind throughout the INK4A-ARF locus and are disassociated in senescent cells

    DEFF Research Database (Denmark)

    Bracken, Adrian P; Kleine-Kohlbrecher, Daniela; Dietrich, Nikolaj

    2007-01-01

    The p16INK4A and p14ARF proteins, encoded by the INK4A-ARF locus, are key regulators of cellular senescence, yet the mechanisms triggering their up-regulation are not well understood. Here, we show that the ability of the oncogene BMI1 to repress the INK4A-ARF locus requires its direct association...... and is dependent on the continued presence of the EZH2-containing Polycomb-Repressive Complex 2 (PRC2) complex. Significantly, EZH2 is down-regulated in stressed and senescing populations of cells, coinciding with decreased levels of associated H3K27me3, displacement of BMI1, and activation of transcription...

  4. Genotipagem de HPV e imunorreatividade da ciclina D1 em adenocarcinoma de colo do útero

    OpenAIRE

    Back, Simony dos Reis Segovia da Silva [UNESP

    2013-01-01

    A incidência do adenocarcinoma do colo do útero (AC) está aumentando em muitos países. A associação entre a infecção pelo Papillomavirus Humano (HPV) e o AC ainda permanece incerta. A imunoistoquímica pode auxiliar no diagnóstico nos casos duvidosos, pois algumas condições benignas reativas podem mimetizar processos neoplásicos. Marcadores como bcl-2, Ki-67 e proteína p16INK4A (p16) já foram descritos para ajudar nas dúvidas relacionadas ao epitélio glandular cervical. Trabalhos recentes demo...

  5. Germline Transgenic Methods for Tracking Cells and Testing Gene Function during Regeneration in the Axolotl

    Science.gov (United States)

    Khattak, Shahryar; Schuez, Maritta; Richter, Tobias; Knapp, Dunja; Haigo, Saori L.; Sandoval-Guzmán, Tatiana; Hradlikova, Kristyna; Duemmler, Annett; Kerney, Ryan; Tanaka, Elly M.

    2013-01-01

    The salamander is the only tetrapod that regenerates complex body structures throughout life. Deciphering the underlying molecular processes of regeneration is fundamental for regenerative medicine and developmental biology, but the model organism had limited tools for molecular analysis. We describe a comprehensive set of germline transgenic strains in the laboratory-bred salamander Ambystoma mexicanum (axolotl) that open up the cellular and molecular genetic dissection of regeneration. We demonstrate tissue-dependent control of gene expression in nerve, Schwann cells, oligodendrocytes, muscle, epidermis, and cartilage. Furthermore, we demonstrate the use of tamoxifen-induced Cre/loxP-mediated recombination to indelibly mark different cell types. Finally, we inducibly overexpress the cell-cycle inhibitor p16INK4a, which negatively regulates spinal cord regeneration. These tissue-specific germline axolotl lines and tightly inducible Cre drivers and LoxP reporter lines render this classical regeneration model molecularly accessible. PMID:24052945

  6. Genomic instability--an evolving hallmark of cancer.

    Science.gov (United States)

    Negrini, Simona; Gorgoulis, Vassilis G; Halazonetis, Thanos D

    2010-03-01

    Genomic instability is a characteristic of most cancers. In hereditary cancers, genomic instability results from mutations in DNA repair genes and drives cancer development, as predicted by the mutator hypothesis. In sporadic (non-hereditary) cancers the molecular basis of genomic instability remains unclear, but recent high-throughput sequencing studies suggest that mutations in DNA repair genes are infrequent before therapy, arguing against the mutator hypothesis for these cancers. Instead, the mutation patterns of the tumour suppressor TP53 (which encodes p53), ataxia telangiectasia mutated (ATM) and cyclin-dependent kinase inhibitor 2A (CDKN2A; which encodes p16INK4A and p14ARF) support the oncogene-induced DNA replication stress model, which attributes genomic instability and TP53 and ATM mutations to oncogene-induced DNA damage.

  7. Assessment of health status by molecular measures in adults ranging from middle-aged to old

    DEFF Research Database (Denmark)

    Waaijer, M. E. C.; Westendorp, R. G. J.; Goldeck, D.

    2017-01-01

    In addition to measures already used in clinical practice, molecular measures have been proposed to assess health status, but these have not yet been introduced into clinical practice. We aimed to test the association of functional capacity measures used in current practice and molecular measures...... with age and health status. The cohort consisted of 178 middle-aged to old participants of the Leiden Longevity Study (range 42-82years). We tested associations between functional capacity measures (physical tests: grip strength, 4-meter walk, chair stand test; cognitive tests: Stroop test, digit symbol...... substitution test and 15-picture learning test) with age and with cardiovascular or metabolic disease as a measure of the health status. These associations with age and health status were also tested for molecular measures (C reactive protein (CRP), numbers of senescent p16INK4a positive cells in the epidermis...

  8. Astragaloside IV Prevents Cardiac Remodeling in the Apolipoprotein E-Deficient Mice by Regulating Cardiac Homeostasis and Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Xiong-Zhi Li

    2017-12-01

    Full Text Available Background: Hypercholesterolemia is a risk factor for the development of cardiac hypertrophy. Astragaloside IV (AST-IV possesses cardiovascular protective properties. We hypothesize that AST-IV prevents cardiac remodeling with hypercholesterolemia via modulating tissue homeostasis and alleviating oxidative stress. Methods: The ApoE-/- mice were treated with AST-IV at 1 or 10 mg/kg for 8 weeks. The blood lipids tests, echocardiography, and TUNEL were performed. The mRNA expression profile was detected by real-time PCR. The myocytes size and number, and the expressions of proliferation (ki67, senescence (p16INK4a, oxidant (NADPH oxidase 4, NOX4 and antioxidant (superoxide dismutase, SOD were observed by immunofluorescence staining. Results: Neither 1 mg/kg nor 10 mg/kg AST-IV treatment could decrease blood lipids in ApoE-/- mice. However, the decreased left ventricular ejection fraction (LVEF and fractional shortening (FS in ApoE–/– mice were significantly improved after AST-IV treatment. The cardiac collagen volume fraction declined nearly in half after AST-IV treatment. The enlarged myocyte size was suppressed, and myocyte number was recovered, and the alterations of genes expressions linked to cell cycle, proliferation, senescence, p53-apoptosis pathway and oxidant-antioxidants in the hearts of ApoE-/- mice were reversed after AST-IV treatment. The decreased ki67 and increased p16INK4a in the hearts of ApoE-/- mice were recovered after AST-IV treatment. The percentages of apoptotic myocytes and NOX4-positive cells in AST-IV treated mice were decreased, which were consistent with the gene expressions. Conclusion: AST-IV treatment could prevent cardiac remodeling and recover the impaired ventricular function induced by hypercholesterolemia. The beneficial effect of AST-IV might partly be through regulating cardiac homeostasis and anti-oxidative stress.

  9. A Review and Update on Papillary Immature Metaplasia of the Uterine Cervix: A Distinct Subset of Low-Grade Squamous Intraepithelial Lesion, Proposing a Possible Cell of Origin.

    Science.gov (United States)

    Hong, Soon Auck; Yoo, Su Hyun; Choi, Jene; Robboy, Stanley J; Kim, Kyu-Rae

    2018-04-13

    - Papillary immature metaplasia (PIM) is a known papillary cervical lesion associated with low-risk human papilloma virus (LR-HPV). - To evaluate additional clinicopathologic features and the HPV genotypes of PIM and discuss the presumptive cell of origin. - A total of 26 PIM cases were evaluated by p16 INK4a , cytokeratin (CK) 7, and CK17 immunohistochemical stainings. Human papilloma virus genotyping was performed, by using HPV DNA Chip, HPV polymerase chain reaction (PCR), and real-time PCR. - Histologically, PIM forms either a papillary mass (n = 21 of 26, 81%) or a slightly elevated/flat plaque (n = 5, 19%). All cases contain variable amounts of mucinous epithelia within the lesions. Koilocytosis was identified in 15 of the 26 cases (58%). Sixteen cases (61%) were associated with LR-HPV (types 6, 11, or 42), but 3 cases (12%) with high-risk (HR) HPV (16, 16/18, and 33), 2 cases (8%) with mixed LR- and HR-HPV (6/16 and 11/58), while 2 cases (8%) were negative, but p16 INK4a immunostaining showed nonblock positivity in all cases. Eight (31%) had high-grade squamous intraepithelial lesion (HSIL) in the adjacent mucosa, 4 (50%) of which showed direct continuity. Identical HPV subtypes were confirmed in separately microdissected cases from PIM and adjacent HSIL. Most lesions (n = 24, 92%) expressed CK17 (reserve cell marker) in a bottom-heavy pattern and CK7 (squamocolumnar junction [SCJ] marker) in a top-heavy pattern, while most cases of low-grade squamous intraepithelial lesion (LSIL) were negative for both markers. - Our results suggest that PIM is a distinct subset of LSIL showing a productive HPV infection, but PIM involves the transformation zone and is proximal to SCJ, while LSIL is mostly from ectocervix or distal to the SCJ.

  10. γ-radiation induces cellular sensitivity and aberrant methylation in human tumor cell lines.

    Science.gov (United States)

    Kumar, Ashok; Rai, Padmalatha S; Upadhya, Raghavendra; Vishwanatha; Prasada, K Shama; Rao, B S Satish; Satyamoorthy, Kapettu

    2011-11-01

    Ionizing radiation induces cellular damage through both direct and indirect mechanisms, which may include effects from epigenetic changes. The purpose of this study was to determine the effect of ionizing radiation on DNA methylation patterns that may be associated with altered gene expression. Sixteen human tumor cell lines originating from various cancers were initially tested for radiation sensitivity by irradiating them with γ-radiation in vitro and subsequently, radiation sensitive and resistant cell lines were treated with different doses of a demethylating agent, 5-Aza-2'-Deoxycytidine (5-aza-dC) and a chromatin modifier, Trichostatin-A (TSA). Survival of these cell lines was measured using 3-(4, 5-Dimethylthiazol- 2-yl)-2, 5-diphenyltetrazolium (MTT) and clonogenic assays. The effect of radiation on global DNA methylation was measured using reverse phase high performance liquid chromatography (RP-HPLC). The transcription response of methylated gene promoters, from cyclin-dependent kinase inhibitor 2A (p16(INK4a)) and ataxia telangiectasia mutated (ATM) genes, to radiation was measured using a luciferase reporter assay. γ-radiation resistant (SiHa and MDAMB453) and sensitive (SaOS2 and WM115) tumor cell lines were examined for the relationship between radiation sensitivity and DNA methylation. Treatment of cells with 5-aza-dC and TSA prior to irradiation enhanced DNA strand breaks, G2/M phase arrest, apoptosis and cell death. Exposure to γ-radiation led to global demethylation in a time-dependent manner in tumor cells in relation to resistance and sensitivity to radiation with concomitant activation of p16(INK4a) and ATM gene promoters. These results provide important information on alterations in DNA methylation as one of the determinants of radiation effects, which may be associated with altered gene expression. Our results may help in delineating the mechanisms of radiation resistance in tumor cells, which can influence diagnosis, prognosis and

  11. NOVEL EPIGENETIC CHANGES IN CDKN2A ARE ASSOCIATED WITH PROGRESSION OF CERVICAL INTRAEPITHELIAL NEOPLASIA

    Science.gov (United States)

    Wijetunga, N. Ari; Belbin, Thomas J.; Burk, Robert D.; Whitney, Kathleen; Abadi, Maria; Greally, John M.; Einstein, Mark H.; Schlecht, Nicolas F.

    2016-01-01

    Objective To conduct a comprehensive mapping of the genomic DNA methylation in CDKN2A, which codes for the p16INK4A and p14ARF proteins, and 14 of the most promising DNA methylation marker candidates previously reported to be associated with progression of low-grade cervical intraepithelial neoplasia (CIN1) to cervical cancer. Methods We analyzed DNA methylation in 68 HIV-seropositive and negative women with incident CIN1, CIN2, CIN3 and invasive cervical cancer, assaying 120 CpG dinucleotide sites spanning APC, CDH1, CDH13, CDKN2A, CDKN2B, DAPK1, FHIT, GSTP1, HIC1, MGMT, MLH1, RARB, RASSF1, TERT and TIMP3 using the Illumina Infinium array. Validation was performed using high resolution mapping of the target genes with HELP-tagging for 286 CpGs, followed by fine mapping of candidate genes with targeted bisulfite sequencing. We assessed for statistical differences in DNA methylation levels for each CpG loci assayed using univariate and multivariate methods correcting for multiple comparisons. Results In our discovery sample set, we identified dose dependent differences in DNA methylation with grade of disease in CDKN2A, APC, MGMT, MLH1 and HIC1, whereas single CpG locus differences between CIN2/3 and cancer groups were seen for CDH13, DAPK1 and TERT. Only those CpGs in the gene body of CDKN2A showed a monotonic increase in methylation between persistent CIN1, CIN2, CIN3 and cancers. Conclusion Our data suggests a novel link between early cervical disease progression and DNA methylation in a region downstream of the CDKN2A transcription start site that may lead to increased p16INK4A/p14ARF expression prior to development of malignant disease. PMID:27401842

  12. Novel epigenetic changes in CDKN2A are associated with progression of cervical intraepithelial neoplasia.

    Science.gov (United States)

    Wijetunga, N Ari; Belbin, Thomas J; Burk, Robert D; Whitney, Kathleen; Abadi, Maria; Greally, John M; Einstein, Mark H; Schlecht, Nicolas F

    2016-09-01

    To conduct a comprehensive mapping of the genomic DNA methylation in CDKN2A, which codes for the p16(INK4A) and p14(ARF) proteins, and 14 of the most promising DNA methylation marker candidates previously reported to be associated with progression of low-grade cervical intraepithelial neoplasia (CIN1) to cervical cancer. We analyzed DNA methylation in 68 HIV-seropositive and negative women with incident CIN1, CIN2, CIN3 and invasive cervical cancer, assaying 120 CpG dinucleotide sites spanning APC, CDH1, CDH13, CDKN2A, CDKN2B, DAPK1, FHIT, GSTP1, HIC1, MGMT, MLH1, RARB, RASSF1, TERT and TIMP3 using the Illumina Infinium array. Validation was performed using high resolution mapping of the target genes with HELP-tagging for 286 CpGs, followed by fine mapping of candidate genes with targeted bisulfite sequencing. We assessed for statistical differences in DNA methylation levels for each CpG loci assayed using univariate and multivariate methods correcting for multiple comparisons. In our discovery sample set, we identified dose dependent differences in DNA methylation with grade of disease in CDKN2A, APC, MGMT, MLH1 and HIC1, whereas single CpG locus differences between CIN2/3 and cancer groups were seen for CDH13, DAPK1 and TERT. Only those CpGs in the gene body of CDKN2A showed a monotonic increase in methylation between persistent CIN1, CIN2, CIN3 and cancers. Our data suggests a novel link between early cervical disease progression and DNA methylation in a region downstream of the CDKN2A transcription start site that may lead to increased p16(INK4A)/p14(ARF) expression prior to development of malignant disease. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Human papilloma virus load and PD-1/PD-L1, CD8+ and FOXP3 in anal cancer patients treated with chemoradiotherapy: Rationale for immunotherapy

    Science.gov (United States)

    Balermpas, Panagiotis; Martin, Daniel; Wieland, Ulrike; Rave-Fränk, Margret; Strebhardt, Klaus; Rödel, Claus; Fokas, Emmanouil; Rödel, Franz

    2017-01-01

    ABSTRACT We examined the prognostic role of immune markers programmed cell death protein-1 (PD-1) and its ligand (PD-L1), CD8+ tumor-infiltrating lymphocytes (TILs), FOXP3+ Tregs and phosphorylated Caspase-8 (T273) in patients with anal squamous cell cancer (ASCC) treated with standard chemoradiotherapy (CRT). The baseline immunohistochemical expression of immune markers was correlated with clinicopathologic characteristics, and cumulative incidence of local failure, disease-free survival (DFS) and overall survival (OS) in 150 patients, also in the context of human papilloma virus 16 (HPV16) DNA load and p16INK4a expression. After a median follow-up of 40 mo (1–205 mo), the 5-y cumulative incidence of local failure and DFS was 19.4% and 67.2%, respectively. Strong immune marker expression was significantly more common in tumors with high HPV16 viral load. In multivariant analysis, high CD8+ and PD-1+ TILs expression predicted for improved local control (p = 0.023 and p = 0.007, respectively) and DFS (p = 0.020 and p = 0.014, respectively). Also, high p16INK4a (p = 0.011) and PD-L1 (p = 0.033) expression predicted for better local control, whereas high FOXP3+ Tregs (p = 0.050) and phosphorylated Caspase-8 (p = 0.031) expression correlated with superior DFS. Female sex and high HPV16 viral load correlated with favorable outcome for all three clinical endpoints. The present data provide, for the first time, robust explanation for the favorable clinical outcome of HPV16-positive ASCC patients harboring strong immune cell infiltration. Our findings are relevant for treatment stratification with immune PD-1/PD-L1 checkpoint inhibitors to complement CRT and should be explored in a clinical trial. PMID:28405521

  14. Etiological role of human papillomavirus infection for inverted papilloma of the bladder.

    Science.gov (United States)

    Shigehara, Kazuyoshi; Sasagawa, Toshiyuki; Doorbar, John; Kawaguchi, Shohei; Kobori, Yoshitomo; Nakashima, Takao; Shimamura, Masayoshi; Maeda, Yuji; Miyagi, Tohru; Kitagawa, Yasuhide; Kadono, Yoshifumi; Konaka, Hiroyuki; Mizokami, Atsushi; Koh, Eitetsu; Namiki, Mikio

    2011-02-01

    The status of human papillomavirus (HPV) infection in urothelial inverted papilloma was examined in the present study. Formalin-fixed and paraffin-embedded tissues from eight cases of inverted papilloma of the bladder were studied. The presence of HPV-DNA was examined by modified GP5/6+PCR using archival tissue sections by microdissection. HPV genotype was determined with a Hybri-Max HPV genotyping kit. Immunohistochemical analysis for p16-INK4a, mcm7, HPV-E4, and L1, and in situ hybridization for the HPV genome were performed. HPV was detected in seven of eight cases (87.5%) of inverted papilloma. Three cases were diagnosed as inverted papilloma with atypia, while the remaining five were typical cases. HPV-18 was detected in two cases, including one inverted papilloma with atypia, and HPV-16 was detected in four cases, including one inverted papilloma with atypia. Multiple HPV type infection was detected in one typical case and one atypical case. High-risk HPV was present in all HPV-positive cases. Cellular proteins, p16-INK4a and mcm7, which are surrogate markers for HPV-E7 expression, were detected in all HPV-positive cases, and their levels were higher in inverted papilloma with atypia than in typical cases. In contrast, HPV-E4 and L1, which are markers for HPV propagation, were observed in some parts of the typical inverted papilloma tissue. High-risk HPV infection may be one of the causes of urothelial inverted papilloma, and inverted papilloma with atypia may have malignant potential. 2010 Wiley-Liss, Inc.

  15. Cancer-associated fibroblasts regulate keratinocyte cell-cell adhesion via TGF-β-dependent pathways in genotype-specific oral cancer.

    Science.gov (United States)

    Cirillo, N; Hassona, Y; Celentano, A; Lim, K P; Manchella, S; Parkinson, E K; Prime, S S

    2017-01-01

    The interrelationship between malignant epithelium and the underlying stroma is of fundamental importance in tumour development and progression. In the present study, we used cancer-associated fibroblasts (CAFs) derived from genetically unstable oral squamous cell carcinomas (GU-OSCC), tumours that are characterized by the loss of genes such as TP53 and p16 INK4A and with extensive loss of heterozygosity, together with CAFs from their more genetically stable (GS) counterparts that have wild-type TP53 and p16 INK4A and minimal loss of heterozygosity (GS-OSCC). Using a systems biology approach to interpret the genome-wide transcriptional profile of the CAFs, we show that transforming growth factor-β (TGF-β) family members not only had biological relevance in silico but also distinguished GU-OSCC-derived CAFs from GS-OSCC CAFs and fibroblasts from normal oral mucosa. In view of the close association between TGF-β family members, we examined the expression of TGF-β1 and TGF-β2 in the different fibroblast subtypes and showed increased levels of active TGF-β1 and TGF-β2 in CAFs from GU-OSCC. CAFs from GU-OSCC, but not GS-OSCC or normal fibroblasts, induced epithelial-mesenchymal transition and down-regulated a broad spectrum of cell adhesion molecules resulting in epithelial dis-cohesion and invasion of target keratinocytes in vitro in a TGF-β-dependent manner. The results demonstrate that the TGF-β family of cytokines secreted by CAFs derived from genotype-specific oral cancer (GU-OSCC) promote, at least in part, the malignant phenotype by weakening intercellular epithelial adhesion. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. Pancreatic intraepithelial neoplasia in association with intraductal papillary mucinous neoplasms of the pancreas: implications for disease progression and recurrence.

    Science.gov (United States)

    Biankin, Andrew V; Kench, James G; Biankin, Sandra A; Lee, C-Soon; Morey, Adrienne L; Dijkman, Floriaan P; Coleman, Maxwell J; Sutherland, Robert L; Henshall, Susan M

    2004-09-01

    The development of pancreatic cancer (PC) several years after curative resection for noninvasive intraductal papillary mucinous neoplasm (IPMN) and the presence of PC distant from IPMN suggest that PC may develop independently of the IPMN. Here, we identified pancreatic intraepithelial neoplasia (PanIN) lesions, the putative precursors of PC, in the ducts of pancreata resected for IPMN and assessed the frequency of molecular aberrations common to PanIN and PC, within these lesions. The protein expression of p53, p21(WAF1/CIP1), cyclin D1, p16(INK4A) and DPC4/Smad4 were examined by immunohistochemistry in 267 PanIN lesions from a cohort of 23 patients with IPMN. Overexpression of p21(WAF1/CIP1) was present in PanIN-1A and -1B lesions and increased in frequency in PanIN-2 and PanIN-3. Overexpression of p53 and cyclin D1, and loss of p16(INK4A) expression were detected in PanIN-2 and PanIN-3 lesions. Loss of DPC4/Smad4 expression occurred only in the PanIN-3 lesions. PanIN lesions that were more dysplastic than the coincident IPMN were identified in 5 of 12 patients, and 2 of these contained a greater number of aberrations in protein expression than the IPMN. PanIN lesions seen in association with IPMN demonstrate molecular and histologic changes identical to PanIN lesions found in association with PC and, in some cases, are more advanced than the associated IPMN. These data suggest that PanIN lesions found in the ducts of a pancreas with IPMN may be relevant to the development of PC either coincident with IPMN or in the remnant pancreas after curative resection of IPMN.

  17. Curcumin Triggers p16-Dependent Senescence in Active Breast Cancer-Associated Fibroblasts and Suppresses Their Paracrine Procarcinogenic Effects

    Directory of Open Access Journals (Sweden)

    Siti-Fauziah Hendrayani

    2013-06-01

    Full Text Available Activated cancer-associated fibroblasts (CAFs or myofibroblasts not only facilitate tumor growth and spread but also affect tumor response to therapeutic agents. Therefore, it became clear that efficient therapeutic regimens should also take into account the presence of these supportive cells and inhibit their paracrine effects. To this end, we tested the effect of low concentrations of curcumin, a pharmacologically safe natural product, on patient-derived primary breast CAF cells. We have shown that curcumin treatment upregulates p16INK4A and other tumor suppressor proteins while inactivates the JAK2/STAT3 pathway. This reduced the level of alpha-smooth muscle actin (α-SMA and the migration/invasion abilities of these cells. Furthermore, curcumin suppressed the expression/secretion of stromal cell-derived factor-1 (SDF-1, interleukin-6 (IL-6, matrix metalloproteinase-2 (MMP-2, MMP-9, and transforming growth factor-β, which impeded their paracrine procarcinogenic potential. Intriguingly, these effects were sustained even after curcumin withdrawal and cell splitting. Therefore, using different markers of senescence [senescence-associated β-galactosidase (SA-β-gal activity, Ki-67 and Lamin B1 levels, and bromodeoxyuridine incorporation], we have shown that curcumin markedly suppresses Lamin B1 and triggers DNA damage-independent senescence in proliferating but not quiescent breast stromal fibroblasts. Importantly, this curcumin-related senescence was p16INK4A-dependent and occurred with no associated inflammatory secretory phenotype. These results indicate the possible inactivation of cancer-associated myofibroblasts and present the first indication that curcumin can trigger DNA damage-independent and safe senescence in stromal fibroblasts.

  18. The SETD8/PR-Set7 Methyltransferase Functions as a Barrier to Prevent Senescence-Associated Metabolic Remodeling

    Directory of Open Access Journals (Sweden)

    Hiroshi Tanaka

    2017-02-01

    Full Text Available Summary: Cellular senescence is an irreversible growth arrest that contributes to development, tumor suppression, and age-related conditions. Senescent cells show active metabolism compared with proliferating cells, but the underlying mechanisms remain unclear. Here we show that the SETD8/PR-Set7 methyltransferase, which catalyzes mono-methylation of histone H4 at lysine 20 (H4K20me1, suppresses nucleolar and mitochondrial activities to prevent cellular senescence. SETD8 protein was selectively downregulated in both oncogene-induced and replicative senescence. Inhibition of SETD8 alone was sufficient to trigger senescence. Under these states, the expression of genes encoding ribosomal proteins (RPs and ribosomal RNAs as well as the cyclin-dependent kinase (CDK inhibitor p16INK4A was increased, with a corresponding reduction of H4K20me1 at each locus. As a result, the loss of SETD8 concurrently stimulated nucleolar function and retinoblastoma protein-mediated mitochondrial metabolism. In conclusion, our data demonstrate that SETD8 acts as a barrier to prevent cellular senescence through chromatin-mediated regulation of senescence-associated metabolic remodeling. : Tanaka et al. show that SETD8/PR-Set7 methyltransferase represses senescence-associated genes including ribosomal proteins, ribosomal RNAs, and p16INK4A by catalyzing mono-methylation of histone H4 at lysine 20. Depletion of SETD8 derepresses these genes, resulting in nucleolar and mitochondrial coactivation characteristic of senescence-associated metabolic remodeling. Keywords: SETD8/PR-Set7, H4K20 methylation, senescence-associated metabolic remodeling, nucleolus, mitochondria

  19. eMelanoBase: an online locus-specific variant database for familial melanoma.

    Science.gov (United States)

    Fung, David C Y; Holland, Elizabeth A; Becker, Therese M; Hayward, Nicholas K; Bressac-de Paillerets, Brigitte; Mann, Graham J

    2003-01-01

    A proportion of melanoma-prone individuals in both familial and non-familial contexts has been shown to carry inactivating mutations in either CDKN2A or, rarely, CDK4. CDKN2A is a complex locus that encodes two unrelated proteins from alternately spliced transcripts that are read in different frames. The alpha transcript (exons 1alpha, 2, and 3) produces the p16INK4A cyclin-dependent kinase inhibitor, while the beta transcript (exons 1beta and 2) is translated as p14ARF, a stabilizing factor of p53 levels through binding to MDM2. Mutations in exon 2 can impair both polypeptides and insertions and deletions in exons 1alpha, 1beta, and 2, which can theoretically generate p16INK4A-p14ARF fusion proteins. No online database currently takes into account all the consequences of these genotypes, a situation compounded by some problematic previous annotations of CDKN2A-related sequences and descriptions of their mutations. As an initiative of the international Melanoma Genetics Consortium, we have therefore established a database of germline variants observed in all loci implicated in familial melanoma susceptibility. Such a comprehensive, publicly accessible database is an essential foundation for research on melanoma susceptibility and its clinical application. Our database serves two types of data as defined by HUGO. The core dataset includes the nucleotide variants on the genomic and transcript levels, amino acid variants, and citation. The ancillary dataset includes keyword description of events at the transcription and translation levels and epidemiological data. The application that handles users' queries was designed in the model-view-controller architecture and was implemented in Java. The object-relational database schema was deduced using functional dependency analysis. We hereby present our first functional prototype of eMelanoBase. The service is accessible via the URL www.wmi.usyd.edu.au:8080/melanoma.html. Copyright 2002 Wiley-Liss, Inc.

  20. Hotair mediates hepatocarcinogenesis through suppressing miRNA-218 expression and activating P14 and P16 signaling.

    Science.gov (United States)

    Fu, Wei-Ming; Zhu, Xiao; Wang, Wei-Mao; Lu, Ying-Fei; Hu, Bao-Guang; Wang, Hua; Liang, Wei-Cheng; Wang, Shan-Shan; Ko, Chun-Hay; Waye, Mary Miu-Yee; Kung, Hsiang-Fu; Li, Gang; Zhang, Jin-Fang

    2015-10-01

    Long non-coding RNA Hotair has been considered as a pro-oncogene in multiple cancers. Although there is emerging evidence that reveals its biological function and the association with clinical prognosis, the precise mechanism remains largely elusive. We investigated the function and mechanism of Hotair in hepatocellular carcinoma (HCC) cell models and a xenograft mouse model. The regulatory network between miR-218 and Hotair was elucidated by RNA immunoprecipitation and luciferase reporter assays. Finally, the correlation between Hotair, miR-218 and the target gene Bmi-1 were evaluated in 52 paired HCC specimens. In this study, we reported that Hotair negatively regulated miR-218 expression in HCC, which might be mediated through an EZH2-targeting-miR-218-2 promoter regulatory axis. Further investigation revealed that Hotair knockdown dramatically inhibited cell viability and induced G1-phase arrest in vitro and suppressed tumorigenicity in vivo by promoting miR-218 expression. Oncogene Bmi-1 was shown to be a functional target of miR-218, and the main downstream targets signaling, P16(Ink4a) and P14(ARF), were activated in Hotair-suppressed tumorigenesis. In primary human HCC specimens, Hotair and Bmi-1 were concordantly upregulated whereas miR-218 was downregulated in these tissues. Furthermore, Hotair was inversely associated with miR-218 expression and positively correlated with Bmi-1 expression in these clinical tissues. Hotair silence activates P16(Ink4a) and P14(ARF) signaling by enhancing miR-218 expression and suppressing Bmi-1 expression, resulting in the suppression of tumorigenesis in HCC. Copyright © 2015 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

  1. Possible involvement of loss of imprinting in immortalization of human fibroblasts.

    Science.gov (United States)

    Okamura, Kotaro; Ohno, Maki; Tsutsui, Takeki

    2011-04-01

    Disruption of the normal pattern of parental origin-specific gene expression is referred to as loss of imprinting (LOI), which is common in various cancers. To investigate a possible role of LOI in the early stage of human cell transformation, we studied LOI in 18 human fibroblast cell lines immortalized spontaneously, by viral oncogenes, by chemical or physical carcinogens, or by infection with a retrovirus vector encoding the human telomerase catalytic subunit, hTERT cDNA. LOI was observed in all the 18 immortal cell lines. The gene most commonly exhibiting LOI was NDN which displayed LOI in 15 of the 18 cell lines (83%). The other genes exhibiting LOI at high frequencies were PEG3 (50%), MAGE-L2 (61%) and ZNF 127 (50%). Expression of NDN that was lost in the immortal cell lines was restored by treatment with 5-aza-2'-deoxycytidine. The ratio of histone H3 lysine 9 methylation to histone H3 lysine 4 methylation of the chromatin containing the NDN promoter in the immortal WI-38VA13 cells was greater than that in the parental cells, suggesting chromatin structure-mediated regulation of NDN expression. We previously demonstrated that inactivation of the p16INK4a/pRb pathway is necessary for immortalization of human cells. Human fibroblasts in the pre-crisis phase and cells with an extended lifespan that eventually senesce, both of which have the normal p16INK4a/pRb pathway, did not show LOI at any imprinted gene examined. Although it is not clear if LOI plays a causal role in immortalization of human cells or is merely coincidental, these findings indicate a possible involvement of LOI in immortalization of human cells or a common mechanism involved in both processes.

  2. Association between glioma susceptibility loci and tumour pathology defines specific molecular etiologies.

    Science.gov (United States)

    Di Stefano, Anna Luisa; Enciso-Mora, Victor; Marie, Yannick; Desestret, Virginie; Labussière, Marianne; Boisselier, Blandine; Mokhtari, Karima; Idbaih, Ahmed; Hoang-Xuan, Khe; Delattre, Jean-Yves; Houlston, Richard S; Sanson, Marc

    2013-05-01

    Genome-wide association studies have identified single-nucleotide polymorphisms (SNPs) at 7 loci influencing glioma risk: rs2736100 (TERT), rs11979158 and rs2252586 (EGFR), rs4295627 (CCDC26), rs4977756 (CDKN2A/CDKN2B), rs498872 (PHLDB1), and rs6010620 (RTEL1). We studied the relationship among these 7 glioma-risk SNPs and characteristics of tumors from 1374 patients, including grade, IDH (ie IDH1 or IDH2) mutation, EGFR amplification, CDKN2A-p16-INK4a homozygous deletion, 9p and 10q loss, and 1p-19q codeletion. rs2736100 (TERT) and rs6010620 (RTEL1) risk alleles were associated with high-grade disease, EGFR amplification, CDKN2A-p16-INK4a homozygous deletion, and 9p and 10q deletion; rs4295627 (CCDC26) and rs498872 (PHLDB1) were associated with low-grade disease, IDH mutation, and 1p-19q codeletion. In contrast, rs4977756 (CDKN2A/B), rs11979158 (EGFR), and to a lesser extent, rs2252586 (EGFR) risk alleles were independent of tumor grade and genetic profile. Adjusting for tumor grade showed a significant association between rs2736100 and IDH status (P = .01), 10q loss (P = .02); rs4295627 and 1p-19q codeletion (P = .04), rs498872 and IDH (P = .02), 9p loss (P = .04), and 10q loss (P = .02). Case-control analyses stratified into 4 molecular classes (defined by 1p-19q status, IDH mutation, and EGFR amplification) showed an association of rs4295627 and rs498872 with IDH-mutated gliomas (P RTEL1, CCDC26, and PHLDB1 variants were associated with different genetic profiles that annotate distinct molecular pathways. Our findings provide further insight into the biological basis of glioma etiology.

  3. Large contribution of human papillomavirus in vaginal neoplastic lesions: a worldwide study in 597 samples.

    Science.gov (United States)

    Alemany, L; Saunier, M; Tinoco, L; Quirós, B; Alvarado-Cabrero, I; Alejo, M; Joura, E A; Maldonado, P; Klaustermeier, J; Salmerón, J; Bergeron, C; Petry, K U; Guimerà, N; Clavero, O; Murillo, R; Clavel, C; Wain, V; Geraets, D T; Jach, R; Cross, P; Carrilho, C; Molina, C; Shin, H R; Mandys, V; Nowakowski, A M; Vidal, A; Lombardi, L; Kitchener, H; Sica, A R; Magaña-León, C; Pawlita, M; Quint, W; Bravo, I G; Muñoz, N; de Sanjosé, S; Bosch, F X

    2014-11-01

    This work describes the human papillomavirus (HPV) prevalence and the HPV type distribution in a large series of vaginal intraepithelial neoplasia (VAIN) grades 2/3 and vaginal cancer worldwide. We analysed 189 VAIN 2/3 and 408 invasive vaginal cancer cases collected from 31 countries from 1986 to 2011. After histopathological evaluation of sectioned formalin-fixed paraffin-embedded samples, HPV DNA detection and typing was performed using the SPF-10/DNA enzyme immunoassay (DEIA)/LiPA25 system (version 1). A subset of 146 vaginal cancers was tested for p16(INK4a) expression, a cellular surrogate marker for HPV transformation. Prevalence ratios were estimated using multivariate Poisson regression with robust variance. HPV DNA was detected in 74% (95% confidence interval (CI): 70-78%) of invasive cancers and in 96% (95% CI: 92-98%) of VAIN 2/3. Among cancers, the highest detection rates were observed in warty-basaloid subtype of squamous cell carcinomas, and in younger ages. Concerning the type-specific distribution, HPV16 was the most frequently type detected in both precancerous and cancerous lesions (59%). p16(INK4a) overexpression was found in 87% of HPV DNA positive vaginal cancer cases. HPV was identified in a large proportion of invasive vaginal cancers and in almost all VAIN 2/3. HPV16 was the most common type detected. A large impact in the reduction of the burden of vaginal neoplastic lesions is expected among vaccinated cohorts. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Arctigenin induces cell cycle arrest by blocking the phosphorylation of Rb via the modulation of cell cycle regulatory proteins in human gastric cancer cells.

    Science.gov (United States)

    Jeong, Jin Boo; Hong, Se Chul; Jeong, Hyung Jin; Koo, Jin Suk

    2011-10-01

    Gastric cancer is a leading cause of cancer-related deaths, worldwide being second only to lung cancer as a cause of death. Arctigenin, a representative dibenzylbutyrolactone lignan, occurs in a variety of plants. However, the molecular mechanisms of arctigenin for anti-tumor effect on gastric cancer have not been examined. This study examined the biological effects of arctigenin on the human gastric cancer cell line SNU-1 and AGS. Cell proliferation was determined by MTT assay. In MTT assay, the proliferation of SNU-1 and AGS cells was significantly inhibited by arctigenin in a time and dose dependent manner, as compared with SNU-1 and AGS cells cultured in the absence of arctigenin. Inhibition of cell proliferation by arctigenin was in part associated with apoptotic cell death, as shown by changes in the expression ratio of Bcl-2 to Bax by arctigenin. Also, arctigenin blocked cell cycle arrest from G(1) to S phase by regulating the expression of cell cycle regulatory proteins such as Rb, cyclin D1, cyclin E, CDK4, CDK2, p21Waf1/Cip1 and p15 INK4b. The antiproliferative effect of arctigenin on SNU-1 and AGS gastric cancer cells revealed in this study suggests that arctigenin has intriguing potential as a chemopreventive or chemotherapeutic agent. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

  5. Endothelial Progenitor Cell Dysfunction in Myelodysplastic Syndromes: Possible Contribution of a Defective Vascular Niche to Myelodysplasia

    Directory of Open Access Journals (Sweden)

    Luciana Teofili

    2015-05-01

    Full Text Available We set a model to replicate the vascular bone marrow niche by using endothelial colony forming cells (ECFCs, and we used it to explore the vascular niche function in patients with low-risk myelodysplastic syndromes (MDS. Overall, we investigated 56 patients and we observed higher levels of ECFCs in MDS than in healthy controls; moreover, MDS ECFCs were found variably hypermethylated for p15INK4b DAPK1, CDH1, or SOCS1. MDS ECFCs exhibited a marked adhesive capacity to normal mononuclear cells. When normal CD34+ cells were co-cultured with MDS ECFCs, they generated significant lower amounts of CD11b+ and CD41+ cells than in co-culture with normal ECFCs. At gene expression profile, several genes involved in cell adhesion were upregulated in MDS ECFCs, while several members of the Wingless and int (Wnt pathways were underexpressed. Furthermore, at miRNA expression profile, MDS ECFCs hypo-expressed various miRNAs involved in Wnt pathway regulation. The addition of Wnt3A reduced the expression of intercellular cell adhesion molecule-1 on MDS ECFCs and restored the defective expression of markers of differentiation. Overall, our data demonstrate that in low-risk MDS, ECFCs exhibit various primary abnormalities, including putative MDS signatures, and suggest the possible contribution of the vascular niche dysfunction to myelodysplasia.

  6. Implication of p53-dependent cellular senescence related gene, TARSH in tumor suppression

    International Nuclear Information System (INIS)

    Wakoh, Takeshi; Uekawa, Natsuko; Terauchi, Kunihiko; Sugimoto, Masataka; Ishigami, Akihito; Shimada, Jun-ichi; Maruyama, Mitsuo

    2009-01-01

    A novel target of NESH-SH3 (TARSH) was identified as a cellular senescence related gene in mouse embryonic fibroblasts (MEFs) replicative senescence, the expression of which has been suppressed in primary clinical lung cancer specimens. However, the molecular mechanism underlying the regulation of TARSH involved in pulmonary tumorigenesis remains unclear. Here we demonstrate that the reduction of TARSH gene expression by short hairpin RNA (shRNA) system robustly inhibited the MEFs proliferation with increase in senescence-associated β-galactosidase (SA-β-gal) activity. Using p53 -/- MEFs, we further suggest that this growth arrest by loss of TARSH is evoked by p53-dependent p21 Cip1 accumulation. Moreover, we also reveal that TARSH reduction induces multicentrosome in MEFs, which is linked in chromosome instability and tumor development. These results suggest that TARSH plays an important role in proliferation of replicative senescence and may serve as a trigger of tumor development.

  7. p53 as Batman: using a movie plot to understand control of the cell cycle.

    Science.gov (United States)

    Gadi, Nikhita; Foley, Sage E; Nowey, Mark; Plopper, George E

    2013-04-16

    This Teaching Resource provides and describes a two-part classroom exercise to help students understand control of the cell cycle, with a focus on the transcription factor p53, the E3 ubiquitin ligase Mdm2, the Mdm2 inhibitor ARF, the kinases ATM and ATR, the kinase Chk2, and the cell cycle inhibitor p21(Cip1). Students use characters and scenes from the movie The Dark Knight to represent elements of the cell cycle control machinery, then they apply these characters and scenes to translate a primary research article on p53 function into a new movie scene in the "Batman universe." This exercise is appropriate for college-level courses in cell biology and cancer biology and requires students to have a background in introductory cell biology. Explicit learning outcomes and associated assessment methods are provided, as well as slides, student assignments, the primary research article, and an instructor's guide for the exercise.

  8. Inhibition of Cell Proliferation and Growth of Pancreatic Cancer by Silencing of Carbohydrate Sulfotransferase 15 In Vitro and in a Xenograft Model.

    Directory of Open Access Journals (Sweden)

    Kazuki Takakura

    Full Text Available Chondroitin sulfate E (CS-E, a highly sulfated glycosaminoglycan, is known to promote tumor invasion and metastasis. Because the presence of CS-E is detected in both tumor and stromal cells in pancreatic ductal adenocarcinoma (PDAC, multistage involvement of CS-E in the development of PDAC has been considered. However, its involvement in the early stage of PDAC progression is still not fully understood. In this study, to clarify the direct role of CS-E in tumor, but not stromal, cells of PDAC, we focused on carbohydrate sulfotransferase 15 (CHST15, a specific enzyme that biosynthesizes CS-E, and investigated the effects of the CHST15 siRNA on tumor cell proliferation in vitro and growth in vivo. CHST15 mRNA is highly expressed in the human pancreatic cancer cell lines PANC-1, MIA PaCa-2, Capan-1 and Capan-2. CHST15 siRNA significantly inhibited the expression of CHST15 mRNA in these four cells in vitro. Silencing of the CHST15 gene in the cells was associated with significant reduction of proliferation and up-regulation of the cell cycle inhibitor-related gene p21CIP1/WAF1. In a subcutaneous xenograft tumor model of PANC-1 in nude mice, a single intratumoral injection of CHST15 siRNA almost completely suppressed tumor growth. Reduced CHST15 protein signals associated with tumor necrosis were observed with the treatment with CHST15 siRNA. These results provide evidence of the direct action of CHST15 on the proliferation of pancreatic tumor cells partly through the p21CIP1/WAF1 pathway. Thus, CHST15-CS-E axis-mediated tumor cell proliferation could be a novel therapeutic target in the early stage of PDAC progression.

  9. L-carnitine is an endogenous HDAC inhibitor selectively inhibiting cancer cell growth in vivo and in vitro.

    Science.gov (United States)

    Huang, Hongbiao; Liu, Ningning; Guo, Haiping; Liao, Siyan; Li, Xiaofen; Yang, Changshan; Liu, Shouting; Song, Wenbin; Liu, Chunjiao; Guan, Lixia; Li, Bing; Xu, Li; Zhang, Change; Wang, Xuejun; Dou, Q Ping; Liu, Jinbao

    2012-01-01

    L-carnitine (LC) is generally believed to transport long-chain acyl groups from fatty acids into the mitochondrial matrix for ATP generation via the citric acid cycle. Based on Warburg's theory that most cancer cells mainly depend on glycolysis for ATP generation, we hypothesize that, LC treatment would lead to disturbance of cellular metabolism and cytotoxicity in cancer cells. In this study, Human hepatoma HepG2, SMMC-7721 cell lines, primary cultured thymocytes and mice bearing HepG2 tumor were used. ATP content was detected by HPLC assay. Cell cycle, cell death and cell viability were assayed by flow cytometry and MTS respectively. Gene, mRNA expression and protein level were detected by gene microarray, Real-time PCR and Western blot respectively. HDAC activities and histone acetylation were detected both in test tube and in cultured cells. A molecular docking study was carried out with CDOCKER protocol of Discovery Studio 2.0 to predict the molecular interaction between L-carnitine and HDAC. Here we found that (1) LC treatment selectively inhibited cancer cell growth in vivo and in vitro; (2) LC treatment selectively induces the expression of p21(cip1) gene, mRNA and protein in cancer cells but not p27(kip1); (4) LC increases histone acetylation and induces accumulation of acetylated histones both in normal thymocytes and cancer cells; (5) LC directly inhibits HDAC I/II activities via binding to the active sites of HDAC and induces histone acetylation and lysine-acetylation accumulation in vitro; (6) LC treatment induces accumulation of acetylated histones in chromatin associated with the p21(cip1) gene but not p27(kip1) detected by ChIP assay. These data support that LC, besides transporting acyl group, works as an endogenous HDAC inhibitor in the cell, which would be of physiological and pathological importance.

  10. Experimental in vivo and in vitro treatment with a new histone deacetylase inhibitor belinostat inhibits the growth of pancreatic cancer

    International Nuclear Information System (INIS)

    Dovzhanskiy, Dmitriy I; Arnold, Stefanie M; Hackert, Thilo; Oehme, Ina; Witt, Olaf; Felix, Klaus; Giese, Nathalia; Werner, Jens

    2012-01-01

    Treatment options for pancreatic ductal adenocarcinoma (PDAC) are limited. Histone deacetylase inhibitors are a new and promising drug family with strong anticancer activity. The aim of this study was to examine the efficacy of in vitro and in vivo treatment with the novel pan-HDAC inhibitor belinostat on the growth of human PDAC cells. The proliferation of tumour cell lines (T3M4, AsPC-1 and Panc-1) was determined using an MTT assay. Apoptosis was analysed using flow cytometry. Furthermore, p21 Cip1/Waf1 and acetylated histone H4 (acH4) expression were confirmed by immunoblot analysis. The in vivo effect of belinostat was studied in a chimeric mouse model. Antitumoural activity was assessed by immunohistochemistry for Ki-67. Treatment with belinostat resulted in significant in vitro and in vivo growth inhibition of PDAC cells. This was associated with a dose-dependent induction of tumour cell apoptosis. The apoptotic effect of gemcitabine was further enhanced by belinostat. Moreover, treatment with belinostat increased expression of the cell cycle regulator p21 Cip1/Waf1 in Panc-1, and of acH4 in all cell lines tested. The reductions in xenograft tumour volumes were associated with inhibition of cell proliferation. Experimental treatment of human PDAC cells with belinostat is effective in vitro and in vivo and may enhance the efficacy of gemcitabine. A consecutive study of belinostat in pancreatic cancer patients alone, and in combination with gemcitabine, could further clarify these effects in the clinical setting

  11. Comparative molecular pathology of cadmium- and all-trans-retinoic acid-induced postaxial forelimb ectrodactyly

    International Nuclear Information System (INIS)

    Liao Xiaoyan; Lee, Grace S.; Shimizu, Hirohito; Collins, Michael D.

    2007-01-01

    Cadmium chloride (CdCl 2 ) and all-trans-retinoic acid (RA) induce postaxial forelimb ectrodactyly in C57BL/6N mice when administered during early limb development, and co-administration yields a synergistic response suggesting a common final pathway to the defect. In the current study, forelimb buds from embryos given high maternal teratogenic doses of CdCl 2 or RA, or the combination of both agents at low doses were collected at various time points after treatment on GD 9.5 and examined for cellular apoptosis, proliferation, and patterning genes. Some cellular perturbations detected in the developing limb bud were similar for both teratogens, whereas other alterations were unique to each agent. For example, at 12 and 18 h, CdCl 2 treatment increased apoptotic cells in the mesenchyme underneath the apical ectodermal ridge (AER), whereas RA caused apoptosis in the AER and proximal mesenchyme. Further, the combined low-dose treatment increased cell death synergistically in all three regions. CdCl 2 and the low-dose combined treatment inhibited mesenchymal proliferation at 12 h, which was associated with induction of p21 cip1 and inhibition of phospho-c-Jun. In contrast, RA did not inhibit mesenchymal proliferation and did not induce p21 cip1 expression or change c-Jun phosphorylation. All three treatment groups showed a delay in the patterning of distal chondrogenesis centers as indicated by Sox9 expression. There was also common inhibition in the expression of AER markers, Fgf8 and Fgf4, and the mesenchymal marker Msx1 involved in the maintenance of epithelial-mesenchymal interactions. Collectively, a model is hypothesized where limb patterning can be perturbed by insults to both ectoderm and mesoderm

  12. Epidermal growth factor treatment decreases mortality and is associated with improved gut integrity in sepsis.

    Science.gov (United States)

    Clark, Jessica A; Clark, Andrew T; Hotchkiss, Richard S; Buchman, Timothy G; Coopersmith, Craig M

    2008-07-01

    Epidermal growth factor (EGF) is a cytoprotective peptide that has healing effects on the intestinal mucosa. We sought to determine whether systemic administration of EGF after the onset of sepsis improved intestinal integrity and decreased mortality. FVB/N mice were subjected to either sham laparotomy or 2 x 23 cecal ligation and puncture (CLP). Septic mice were further randomized to receive injection of either 150 microg kg(-1) d(-1) (i.p.) EGF or 0.9% saline (i.p.). Circulating EGF levels were decreased after CLP compared with sham animals but were unaffected by giving exogenous EGF treatment. In contrast, intestinal EGF levels increased after CLP and were further augmented by exogenous EGF treatment. Intestinal EGF receptor was increased after CLP, whether assayed by immunohistochemistry, real-time polymerase chain reaction, or Western blot, and exogenous EGF treatment decreased intestinal EGF receptor. Villus length decreased 2-fold between sham and septic animals, and EGF treatment resulted in near total restitution of villus length. Sepsis decreased intestinal proliferation and increased intestinal apoptosis. This was accompanied by increased expression of the proapoptotic proteins Bid and Fas-associated death domain, as well as the cyclin-dependent kinase inhibitor p21 cip1/waf Epidermal growth factor treatment after the onset of sepsis restored both proliferation and apoptosis to levels seen in sham animals and normalized expression of Bid, Fas-associated death domain, and p21 cip1/waf . To determine whether improvements in gut homeostasis were associated with a decrease in sepsis-induced mortality, septic mice with or without EGF treatment after CLP were followed 7 days for survival. Mortality decreased from 60% to 30% in mice treated with EGF after the onset of sepsis (P < 0.05). Thus, EGF may be a potential therapeutic agent for the treatment of sepsis in part due to its ability to protect intestinal integrity.

  13. Role of Human Papillomavirus in Penile Carcinomas Worldwide.

    Science.gov (United States)

    Alemany, Laia; Cubilla, Antonio; Halec, Gordana; Kasamatsu, Elena; Quirós, Beatriz; Masferrer, Emili; Tous, Sara; Lloveras, Belén; Hernández-Suarez, Gustavo; Lonsdale, Ray; Tinoco, Leopoldo; Alejo, Maria; Alvarado-Cabrero, Isabel; Laco, Jan; Guimerà, Nuria; Poblet, Enrique; Lombardi, Luis E; Bergeron, Christine; Clavero, Omar; Shin, Hai-Rim; Ferrera, Annabelle; Felix, Ana; Germar, Julieta; Mandys, Vaclav; Clavel, Christine; Tzardi, Maria; Pons, Luis E; Wain, Vincent; Cruz, Eugenia; Molina, Carla; Mota, Jose D; Jach, Robert; Velasco, Julio; Carrilho, Carla; López-Revilla, Ruben; Goodman, Marc T; Quint, Wim G; Castellsagué, Xavier; Bravo, Ignacio; Pawlita, Michael; Muñoz, Nubia; Bosch, F Xavier; de Sanjosé, Silvia

    2016-05-01

    Invasive penile cancer is a rare disease with an approximately 22 000 cases per year. The incidence is higher in less developed countries, where penile cancer can account for up to 10% of cancers among men in some parts of Africa, South America, and Asia. To describe the human papillomavirus (HPV) DNA prevalence, HPV type distribution, and detection of markers of viral activity (ie, E6*I mRNA and p16(INK4a)) in a series of invasive penile cancers and penile high-grade squamous intraepithelial lesions (HGSILs) from 25 countries. A total of 85 penile HGSILs and 1010 penile invasive cancers diagnosed from 1983 to 2011 were included. After histopathologic evaluation of formalin-fixed paraffin-embedded samples, HPV DNA detection and genotyping were performed using the SPF-10/DEIA/LiPA25 system, v.1 (Laboratory Biomedical Products, Rijswijk, The Netherlands). HPV DNA-positive cases were additionally tested for oncogene E6*I mRNA and all cases for p16(INK4a) expression, a surrogate marker of oncogenic HPV activity. HPV DNA prevalence and type distributions were estimated. HPV DNA was detected in 33.1% of penile cancers (95% confidence interval [CI], 30.2-36.1) and in 87.1% of HGSILs (95% CI, 78.0-93.4). The warty-basaloid histologic subtype showed the highest HPV DNA prevalence. Among cancers, statistically significant differences in prevalence were observed only by geographic region and not by period or by age at diagnosis. HPV16 was the most frequent HPV type detected in both HPV-positive cancers (68.7%) and HGSILs (79.6%). HPV6 was the second most common type in invasive cancers (3.7%). The p16(INK4a) upregulation and mRNA detection in addition to HPV DNA positivity were observed in 69.3% of HGSILs, and at least one of these HPV activity markers was detected in 85.3% of cases. In penile cancers, these figures were 22.0% and 27.1%, respectively. About a third to a fourth of penile cancers were related to HPV when considering HPV DNA detection alone or adding an HPV

  14. 2-Methoxy-4-vinylphenol can induce cell cycle arrest by blocking the hyper-phosphorylation of retinoblastoma protein in benzo[a]pyrene-treated NIH3T3 cells

    International Nuclear Information System (INIS)

    Jeong, Jin Boo; Jeong, Hyung Jin

    2010-01-01

    Research highlights: → 2M4VP activated the expression of p21 and p15 protein, and down-regulated the expression of cyclin D1 and cyclin E. → 2M4VP inhibited hyper-phosphorylation of Rb protein. → 2M4VP induced cell cycle arrest from G1 to S. → 2M4VP inhibited hyper-proliferation of the cells in BaP-treated cells. → 2M4VP induces growth arrest of BaP-treated cells by blocking hyper-phosphorylation of Rb via regulating the expression of cell cycle-related proteins. -- Abstract: Benzo[a]pyrene (BaP) is an environment carcinogen that can enhance cell proliferation by disturbing the signal transduction pathways in cell cycle regulation. In this study, the effects of 2M4VP on cell proliferation, cell cycle and cell cycle regulatory proteins were studied in BaP-treated NIH 3T3 cells to establish the molecular mechanisms of 2M4VP as anti-proliferative agents. 2M4VP exerted a dose-dependent inhibitory effect on cell growth correlated with a G1 arrest. Analysis of G1 cell cycle regulators expression revealed 2M4VP increased expression of CDK inhibitor, p21Waf1/Cip1 and p15 INK4b, decreased expression of cyclin D1 and cyclin E, and inhibited kinase activities of CDK4 and CDK2. However, 2M4VP did not affect the expression of CDK4 and CDK2. Also, 2M4VP inhibited the hyper-phosphorylation of Rb induced by BaP. Our results suggest that 2M4VP induce growth arrest of BaP-treated NIH 3T3 cells by blocking the hyper-phosphorylation of Rb via regulating the expression of cell cycle-related proteins.

  15. 2-Methoxy-4-vinylphenol can induce cell cycle arrest by blocking the hyper-phosphorylation of retinoblastoma protein in benzo[a]pyrene-treated NIH3T3 cells

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Jin Boo [Bioresource Sciences, Andong National University, Andong 760749 (Korea, Republic of); Jeong, Hyung Jin, E-mail: jhj@andong.ac.kr [Bioresource Sciences, Andong National University, Andong 760749 (Korea, Republic of)

    2010-10-01

    Research highlights: {yields} 2M4VP activated the expression of p21 and p15 protein, and down-regulated the expression of cyclin D1 and cyclin E. {yields} 2M4VP inhibited hyper-phosphorylation of Rb protein. {yields} 2M4VP induced cell cycle arrest from G1 to S. {yields} 2M4VP inhibited hyper-proliferation of the cells in BaP-treated cells. {yields} 2M4VP induces growth arrest of BaP-treated cells by blocking hyper-phosphorylation of Rb via regulating the expression of cell cycle-related proteins. -- Abstract: Benzo[a]pyrene (BaP) is an environment carcinogen that can enhance cell proliferation by disturbing the signal transduction pathways in cell cycle regulation. In this study, the effects of 2M4VP on cell proliferation, cell cycle and cell cycle regulatory proteins were studied in BaP-treated NIH 3T3 cells to establish the molecular mechanisms of 2M4VP as anti-proliferative agents. 2M4VP exerted a dose-dependent inhibitory effect on cell growth correlated with a G1 arrest. Analysis of G1 cell cycle regulators expression revealed 2M4VP increased expression of CDK inhibitor, p21Waf1/Cip1 and p15 INK4b, decreased expression of cyclin D1 and cyclin E, and inhibited kinase activities of CDK4 and CDK2. However, 2M4VP did not affect the expression of CDK4 and CDK2. Also, 2M4VP inhibited the hyper-phosphorylation of Rb induced by BaP. Our results suggest that 2M4VP induce growth arrest of BaP-treated NIH 3T3 cells by blocking the hyper-phosphorylation of Rb via regulating the expression of cell cycle-related proteins.

  16. In Vivo Senescence in the Sbds-Deficient Murine Pancreas: Cell-Type Specific Consequences of Translation Insufficiency.

    Directory of Open Access Journals (Sweden)

    Marina E Tourlakis

    2015-06-01

    Full Text Available Genetic models of ribosome dysfunction show selective organ failure, highlighting a gap in our understanding of cell-type specific responses to translation insufficiency. Translation defects underlie a growing list of inherited and acquired cancer-predisposition syndromes referred to as ribosomopathies. We sought to identify molecular mechanisms underlying organ failure in a recessive ribosomopathy, with particular emphasis on the pancreas, an organ with a high and reiterative requirement for protein synthesis. Biallelic loss of function mutations in SBDS are associated with the ribosomopathy Shwachman-Diamond syndrome, which is typified by pancreatic dysfunction, bone marrow failure, skeletal abnormalities and neurological phenotypes. Targeted disruption of Sbds in the murine pancreas resulted in p53 stabilization early in the postnatal period, specifically in acinar cells. Decreased Myc expression was observed and atrophy of the adult SDS pancreas could be explained by the senescence of acinar cells, characterized by induction of Tgfβ, p15(Ink4b and components of the senescence-associated secretory program. This is the first report of senescence, a tumour suppression mechanism, in association with SDS or in response to a ribosomopathy. Genetic ablation of p53 largely resolved digestive enzyme synthesis and acinar compartment hypoplasia, but resulted in decreased cell size, a hallmark of decreased translation capacity. Moreover, p53 ablation resulted in expression of acinar dedifferentiation markers and extensive apoptosis. Our findings indicate a protective role for p53 and senescence in response to Sbds ablation in the pancreas. In contrast to the pancreas, the Tgfβ molecular signature was not detected in fetal bone marrow, liver or brain of mouse models with constitutive Sbds ablation. Nevertheless, as observed with the adult pancreas phenotype, disease phenotypes of embryonic tissues, including marked neuronal cell death due to apoptosis

  17. In Vivo Senescence in the Sbds-Deficient Murine Pancreas: Cell-Type Specific Consequences of Translation Insufficiency

    Science.gov (United States)

    Tourlakis, Marina E.; Zhang, Siyi; Ball, Heather L.; Gandhi, Rikesh; Liu, Hongrui; Zhong, Jian; Yuan, Julie S.; Guidos, Cynthia J.; Durie, Peter R.; Rommens, Johanna M.

    2015-01-01

    Genetic models of ribosome dysfunction show selective organ failure, highlighting a gap in our understanding of cell-type specific responses to translation insufficiency. Translation defects underlie a growing list of inherited and acquired cancer-predisposition syndromes referred to as ribosomopathies. We sought to identify molecular mechanisms underlying organ failure in a recessive ribosomopathy, with particular emphasis on the pancreas, an organ with a high and reiterative requirement for protein synthesis. Biallelic loss of function mutations in SBDS are associated with the ribosomopathy Shwachman-Diamond syndrome, which is typified by pancreatic dysfunction, bone marrow failure, skeletal abnormalities and neurological phenotypes. Targeted disruption of Sbds in the murine pancreas resulted in p53 stabilization early in the postnatal period, specifically in acinar cells. Decreased Myc expression was observed and atrophy of the adult SDS pancreas could be explained by the senescence of acinar cells, characterized by induction of Tgfβ, p15Ink4b and components of the senescence-associated secretory program. This is the first report of senescence, a tumour suppression mechanism, in association with SDS or in response to a ribosomopathy. Genetic ablation of p53 largely resolved digestive enzyme synthesis and acinar compartment hypoplasia, but resulted in decreased cell size, a hallmark of decreased translation capacity. Moreover, p53 ablation resulted in expression of acinar dedifferentiation markers and extensive apoptosis. Our findings indicate a protective role for p53 and senescence in response to Sbds ablation in the pancreas. In contrast to the pancreas, the Tgfβ molecular signature was not detected in fetal bone marrow, liver or brain of mouse models with constitutive Sbds ablation. Nevertheless, as observed with the adult pancreas phenotype, disease phenotypes of embryonic tissues, including marked neuronal cell death due to apoptosis, were determined to

  18. Hypermethylation of gene promoters in peripheral blood leukocytes in humans long term after radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    Kuzmina, Nina S., E-mail: nin-kuzmin@youndex.ru; Lapteva, Nellya Sh.; Rubanovich, Alexander V.

    2016-04-15

    Some human genes known to undergo age-related promoter hypermethylation. These epigenetic modifications are similar to those occurring in the course of certain diseases, e.g. some types of cancer, which in turn may also associate with age. Given external genotoxic factors may additionally contribute to hypermethylation, this study was designed to analyzes, using methylation-sensitive polymerase chain reaction (PCR), the CpG island hypermethylation in RASSF1A, CDKN2A (including p16/INK4A and p14/ARF) and GSTP1 promoters in peripheral blood leukocytes of individuals exposed to ionizing radiation long time ago. One hundred and twenty-four irradiated subjects (24–77 years old at sampling: 83 Chernobyl Nuclear Power Plant clean-up workers, 21 nuclear workers, 20 residents of territories with radioactive contamination) and 208 unirradiated volunteers (19–77 years old at sampling) were enrolled. In addition, 74 non-exposed offspring (2–51 years old at sampling) born to irradiated parents were examined. The frequency of individuals displaying promoter methylation of at least one gene in exposed group was significantly higher as compared to the control group (OR=5.44, 95% CI=2.62–11.76, p=3.9×10{sup −7}). No significant difference was found between the frequency of subjects with the revealed promoter methylation in the group of offspring born to irradiated parents and in the control group. The increase in the number of methylated loci of RASSF1A and p14/ARF was associated with age (β=0.242; p=1.7×10{sup −5}). In contrast, hypermethylation of p16/INK4A and GSTP1 genes correlated with the fact of radiation exposure only (β=0.290; p=1.7×10{sup −7}). The latter finding demonstrates that methylation changes in blood leukocytes of healthy subjects exposed to radiation resemble those reported in human malignancies. Additional studies are required to identify the dose-response of epigenetic markers specifically associating with radiation-induced premature aging

  19. Hypermethylation of gene promoters in peripheral blood leukocytes in humans long term after radiation exposure

    International Nuclear Information System (INIS)

    Kuzmina, Nina S.; Lapteva, Nellya Sh.; Rubanovich, Alexander V.

    2016-01-01

    Some human genes known to undergo age-related promoter hypermethylation. These epigenetic modifications are similar to those occurring in the course of certain diseases, e.g. some types of cancer, which in turn may also associate with age. Given external genotoxic factors may additionally contribute to hypermethylation, this study was designed to analyzes, using methylation-sensitive polymerase chain reaction (PCR), the CpG island hypermethylation in RASSF1A, CDKN2A (including p16/INK4A and p14/ARF) and GSTP1 promoters in peripheral blood leukocytes of individuals exposed to ionizing radiation long time ago. One hundred and twenty-four irradiated subjects (24–77 years old at sampling: 83 Chernobyl Nuclear Power Plant clean-up workers, 21 nuclear workers, 20 residents of territories with radioactive contamination) and 208 unirradiated volunteers (19–77 years old at sampling) were enrolled. In addition, 74 non-exposed offspring (2–51 years old at sampling) born to irradiated parents were examined. The frequency of individuals displaying promoter methylation of at least one gene in exposed group was significantly higher as compared to the control group (OR=5.44, 95% CI=2.62–11.76, p=3.9×10 −7 ). No significant difference was found between the frequency of subjects with the revealed promoter methylation in the group of offspring born to irradiated parents and in the control group. The increase in the number of methylated loci of RASSF1A and p14/ARF was associated with age (β=0.242; p=1.7×10 −5 ). In contrast, hypermethylation of p16/INK4A and GSTP1 genes correlated with the fact of radiation exposure only (β=0.290; p=1.7×10 −7 ). The latter finding demonstrates that methylation changes in blood leukocytes of healthy subjects exposed to radiation resemble those reported in human malignancies. Additional studies are required to identify the dose-response of epigenetic markers specifically associating with radiation-induced premature aging and/or with

  20. SQUAMOUS CELL CARCINOMA OF THE HEAD AND NECK: NEW AVENUES OF TREATMENT?

    Directory of Open Access Journals (Sweden)

    T. Braunschweig

    2013-01-01

    Full Text Available Squamous cell carcinoma of the head and neck counts for 3 % of all cancers in men and half of this number less in women with a 5-year survival of 61 %. While the number of laryngeal carcinoma is decreasing, carcinoma of the oral cavity related to an infection by the human papilloma virus (HPV, high-risk subtypes is increasing, especially in younger patients. HPV related squamous cell carcinomas show better survival data, especially in regard to recurrence free rates or secondary carcinoma of adjacent locations. Squamous cell carcinomas related to the presence of HPV DNA material is almost exclusively found in carcinoma of the oral cavity and oropharyngeal mucosa. Much less frequently HPV is present in hypopharyngeal carcinomas and even less number of cases of squamous cell carcinoma with proof for HPV in the nasopharynx and larynx. In case of evidence for HPV DNA; most cases are positively tested for subtype 16, followed by subtype 18. As a surrogate immunhistochemical marker, p16 INK4A is stained positive, cytoplasmic and nuclear. In a small study by ourselves, we found a positive correlation in 100 % of p16 INK4A positivity and positive HPV testing. Oral squamous cell carcinoma is more frequently related to HPV in patients below 50 years of age with a prevalence of ca. 20 %. Whilst HPV high-risk positive carcinomas show very few mutations in single signalling molecules of the downstream receptor tyrosin kinase pathways, HPV negative carcinomas show in many cases a chaotic DNA mutation type with typical mutations in tumor suppressor genes, as p53 and CDKN2A. This pattern is often seen in carcinoma types develop from a summation of accidental mutations often caused by toxins (e.g. inhaled cigarette smoke. However, it is discussed and under investigation whether a subset of head and neck squamous cell carcinomasdevelop from so called driver mutations, as are called mutations in critical members of signalling pathways and receptor tyrosin kinases

  1. Induction of S-phase entry by E2F transcription factors depends on their nuclear localization

    DEFF Research Database (Denmark)

    Müller, H; Moroni, M C; Vigo, E

    1997-01-01

    The E2F transcription factors are essential for regulating the correct timing of activation of several genes whose products are implicated in cell proliferation and DNA replication. The E2Fs are targets for negative regulation by the retinoblastoma protein family, which includes pRB, p107, and p130......, and they are in a pathway that is frequently found altered in human cancers. There are five members of the E2F family, and they can be divided into two functional subgroups. Whereas, upon overexpression, E2F-1, -2, and -3 induce S phase in quiescent fibroblasts and override G1 arrests mediated by the p16INK4A tumor...... suppressor protein or neutralizing antibodies to cyclin D1, E2F-4 and -5 do not. Using E2F-1 and E2F-4 as representatives of the two subgroups, we showed here, by constructing a set of chimeric proteins, that the amino terminus of E2F-1 is sufficient to confer S-phase-inducing potential as well...

  2. Autocrine IL-6 mediates pituitary tumor senescence

    Science.gov (United States)

    Fuertes, Mariana; Ajler, Pablo; Carrizo, Guillermo; Cervio, Andrés; Sevlever, Gustavo; Stalla, Günter K.; Arzt, Eduardo

    2017-01-01

    Cellular senescence is a stable proliferative arrest state. Pituitary adenomas are frequent and mostly benign, but the mechanism for this remains unknown. IL-6 is involved in pituitary tumor progression and is produced by the tumoral cells. In a cell autonomous fashion, IL-6 participates in oncogene-induced senescence in transduced human melanocytes. Here we prove that autocrine IL-6 participates in pituitary tumor senescence. Endogenous IL-6 inhibition in somatotroph MtT/S shRNA stable clones results in decreased SA-β-gal activity and p16INK4a but increased pRb, proliferation and invasion. Nude mice injected with IL-6 silenced clones develop tumors contrary to MtT/S wild type that do not, demonstrating that clones that escape senescence are capable of becoming tumorigenic. When endogenous IL-6 is silenced, cell cultures derived from positive SA-β-gal human tumor samples decrease the expression of the senescence marker. Our results establish that IL-6 contributes to maintain senescence by its autocrine action, providing a natural model of IL-6 mediated benign adenoma senescence. PMID:27902467

  3. Gene expression profiling in cervical cancer: identification of novel markers for disease diagnosis and therapy.

    LENUS (Irish Health Repository)

    Martin, Cara M

    2012-02-01

    Cervical cancer, a potentially preventable disease, remains the second most common malignancy in women worldwide. Human papillomavirus is the single most important etiological agent in cervical cancer. HPV contributes to neoplastic progression through the action of two viral oncoproteins E6 and E7, which interfere with critical cell cycle pathways, p53, and retinoblastoma. However, evidence suggests that HPV infection alone is insufficient to induce malignant changes and other host genetic variations are important in the development of cervical cancer. Advances in molecular biology and high throughput gene expression profiling technologies have heralded a new era in biomarker discovery and identification of molecular targets related to carcinogenesis. These advancements have improved our understanding of carcinogenesis and will facilitate screening, early detection, management, and personalised targeted therapy. In this chapter, we have described the use of high density microarrays to assess gene expression profiles in cervical cancer. Using this approach we have identified a number of novel genes which are differentially expressed in cervical cancer, including several genes involved in cell cycle regulation. These include p16ink4a, MCM 3 and 5, CDC6, Geminin, Cyclins A-D, TOPO2A, CDCA1, and BIRC5. We have validated expression of mRNA using real-time PCR and protein by immunohistochemistry.

  4. MIA PaCa-2 and PANC-1 - pancreas ductal adenocarcinoma cell lines with neuroendocrine differentiation and somatostatin receptors.

    Science.gov (United States)

    Gradiz, Rui; Silva, Henriqueta C; Carvalho, Lina; Botelho, Maria Filomena; Mota-Pinto, Anabela

    2016-02-17

    Studies using cell lines should always characterize these cells to ensure that the results are not distorted by unexpected morphological or genetic changes possibly due to culture time or passage number. Thus, the aim of this study was to describe those MIA PaCa-2 and PANC-1 cell line phenotype and genotype characteristics that may play a crucial role in pancreatic cancer therapeutic assays, namely neuroendocrine chemotherapy and peptide receptor radionuclide therapy. Epithelial, mesenchymal, endocrine and stem cell marker characterization was performed by immunohistochemistry and flow cytometry, and genotyping by PCR, gene sequencing and capillary electrophoresis. MIA PaCa-2 (polymorphism) expresses CK5.6, AE1/AE3, E-cadherin, vimentin, chromogranin A, synaptophysin, SSTR2 and NTR1 but not CD56. PANC-1 (pleomorphism) expresses CK5.6, MNF-116, vimentin, chromogranin A, CD56 and SSTR2 but not E-cadherin, synaptophysin or NTR1. MIA PaCA-1 is CD24(-), CD44(+/++), CD326(-/+) and CD133/1(-), while PANC-1 is CD24(-/+), CD44(+), CD326(-/+) and CD133/1(-). Both cell lines have KRAS and TP53 mutations and homozygous deletions including the first 3 exons of CDKN2A/p16(INK4A), but no SMAD4/DPC4 mutations or microsatellite instability. Both have neuroendocrine differentiation and SSTR2 receptors, precisely the features making them suitable for the therapies we propose to assay in future studies.

  5. The Stem Cell Hypothesis of Aging

    Directory of Open Access Journals (Sweden)

    Anna Meiliana

    2010-04-01

    Full Text Available BACKGROUND: There is probably no single way to age. Indeed, so far there is no single accepted explanation or mechanisms of aging (although more than 300 theories have been proposed. There is an overall decline in tissue regenerative potential with age, and the question arises as to whether this is due to the intrinsic aging of stem cells or rather to the impairment of stem cell function in the aged tissue environment. CONTENT: Recent data suggest that we age, in part, because our self-renewing stem cells grow old as a result of heritable intrinsic events, such as DNA damage, as well as extrinsic forces, such as changes in their supporting niches. Mechanisms that suppress the development of cancer, such as senescence and apoptosis, which rely on telomere shortening and the activities of p53 and p16INK4a may also induce an unwanted consequence: a decline in the replicative function of certain stem cells types with advancing age. This decrease regenerative capacity appears to pointing to the stem cell hypothesis of aging. SUMMARY: Recent evidence suggested that we grow old partly because of our stem cells grow old as a result of mechanisms that suppress the development of cancer over a lifetime. We believe that a further, more precise mechanistic understanding of this process will be required before this knowledge can be translated into human anti-aging therapies. KEYWORDS: stem cells, senescence, telomere, DNA damage, epigenetic, aging.

  6. Contribution to the study of markers in lungs carcinogenesis and analysis of factors predicting the benefit of chemotherapy

    International Nuclear Information System (INIS)

    Olaussen, K.A.

    2006-06-01

    A better definition of early bio markers in lung carcinogenesis should enhance the development of molecular means to perform screening, diagnostic, and chemo-prevention of patients at high risk of lung cancer. We studied epigenetic deregulation of multiple promoters (p16(INK4a), HOX A9, MAGE A 1 et MAGE B2) in sputum samples from smokers at high risk and from patients with non-small cell lung cancer (N.S.C.L.C.). This molecular test, based on easily accessible sample,s can be modulated according to the aims of the investigator (e.g. screening or confirmation of diagnosis). Secondly, we have studied two candidate proteins as predictive markers of the benefit of adjuvant chemotherapy in patients with resected lung cancer. The multivariate analysis shows that tumor expression of the catalytic sub-unit of telomerase is not able to predict survival in patients included in the lAL T study' of adjuvant chemotherapy. However, tumor expression of the DNA repair protein ERCC1 identifies a sub-group of patients (ERCC1 negative) whose chances of survival are increased by 35% by means of cisplatin-based adjuvant chemotherapy. Further, tumor ERCC1 expression has a positive prognostic value in the non-treated control group. The need for a deeper understanding in cancerology of the physiological role of the ERCC1 endonuclease is discussed in this thesis. (author)

  7. Antineoplastic activity of the DNA methyltransferase inhibitor 5-aza-2′-deoxycytidine in anaplastic large cell lymphoma

    Science.gov (United States)

    Hassler, Melanie R.; Klisaroska, Aleksandra; Kollmann, Karoline; Steiner, Irene; Bilban, Martin; Schiefer, Ana-Iris; Sexl, Veronika; Egger, Gerda

    2012-01-01

    DNA methylation is an epigenetic mechanism establishing long-term gene silencing during development and cell commitment, which is maintained in subsequent cell generations. Aberrant DNA methylation is found at gene promoters in most cancers and can lead to silencing of tumor suppressor genes. The DNA methyltransferase inhibitor 5-aza-2′-deoxycytidine (5-aza-CdR) is able to reactivate genes silenced by DNA methylation and has been shown to be a very potent epigenetic drug in several hematological malignancies. In this report, we demonstrate that 5-aza-CdR exhibits high antineoplastic activity against anaplastic large cell lymphoma (ALCL), a rare CD30 positive non-Hodgkin lymphoma of T-cell origin. Low dose treatment of ALCL cell lines and xenografted tumors causes apoptosis and cell cycle arrest in vitro and in vivo. This is also reflected in genome-wide expression analyses, where genes related to apoptosis and cell death are amongst the most affected targets of 5-aza-CdR. Furthermore, we observed demethylation and re-expression of p16INK4A after drug administration and senescence associated β-galactosidase activity. Thus, our data provide evidence that 5-aza-CdR is highly efficient against ALCL and warrants further clinical evaluation for future therapeutic use. PMID:22687603

  8. Attenuation of p38α MAPK stress response signaling delays the in vivo aging of skeletal muscle myofibers and progenitor cells.

    Science.gov (United States)

    Papaconstantinou, John; Wang, Chen Z; Zhang, Min; Yang, San; Deford, James; Bulavin, Dmitry V; Ansari, Naseem H

    2015-09-01

    Functional competence and self-renewal of mammalian skeletal muscle myofibers and progenitor cells declines with age. Progression of the muscle aging phenotype involves the decline of juvenile protective factorsi.e., proteins whose beneficial functions translate directly to the quality of life, and self-renewal of progenitor cells. These characteristics occur simultaneously with the age-associated increase of p38α stress response signaling. This suggests that the maintenance of low levels of p38α activity of juvenile tissues may delay or attenuate aging. We used the dominant negative haploinsufficient p38α mouse (DN-p38α(AF/+)) to demonstrate that in vivo attenuation of p38α activity in the gastrocnemius of the aged mutant delays age-associated processes that include: a) the decline of the juvenile protective factors, BubR1, aldehyde dehydrogenase 1A (ALDH1A1), and aldehyde dehydrogenase 2 (ALDH2); b) attenuated expression of p16(Ink4a) and p19(Arf) tumor suppressor genes of the Cdkn2a locus; c) decreased levels of hydroxynonenal protein adducts, expression of COX2 and iNOS; d) decline of the senescent progenitor cell pool level and d) the loss of gastrocnemius muscle mass. We propose that elevated P-p38α activity promotes skeletal muscle aging and that the homeostasis of p38α impacts the maintenance of a beneficial healthspan.

  9. Analysis of human papilloma virus in oral squamous cell carcinoma using p16: An immunohistochemical study

    Science.gov (United States)

    Patil, S.; Rao, R. S.; Amrutha, N.; Sanketh, D. S.

    2014-01-01

    Aims: The aim of this study is to evaluate the expression of human papilloma virus (HPV) in oral squamous cell carcinoma (OSCC) and to correlate the association of HPV in histological grades of OSCC using p16 (p16INK4a) immunohistochemistry (IHC). Subjects and Methods: This study consists of 30 histological diagnosed cases of OSCC (10-well-differentiated oral squamous cell carcinoma [WDOSCC], 10-moderately differentiated oral squamous cell carcinoma [MDOSCC] and 10-poorly differentiated oral squamous cell carcinoma [PDOSCC]). The sections were subjected to IHC procedure using p16. Two parameters in immunohistochemical p16 expression were evaluated by 3 observers based on the criteria by Galgano M. Tetal (2010) (a) percentage of p16 positive cases (b) pattern of p16 staining in various grades of OSCC. Statistical Analysis Used: Kappa test. Results: Totally, 30 samples of 0SCC, p16 positivity was noted in 26/30 (86.66%). Of 26 positive cases, p16 staining was positive in 7/10 (70%) of WDOSCC, 9/10 (90%) in MDOSCC and, 10/10 (100%) PDOSCC. Incidentally, we also found single dispersed cell staining in WDOSCC, patchy staining in MDOSCC and more diffuse staining pattern predominant in PDOSCC. Conclusions: Our study revealed an association between HPV and OSCC. Diffuse staining pattern was noted in PDOSCC, which in turn depicts the increase viral overload, which might have an influence on its aggressive behavior. PMID:24818098

  10. Emerging roles of hypoxia-inducible factors and reactive oxygen species in cancer and pluripotent stem cells

    Directory of Open Access Journals (Sweden)

    Shigeo Saito

    2015-06-01

    Full Text Available Eukaryotic organisms require oxygen homeostasis to maintain proper cellular function for survival. During conditions of low oxygen tension (hypoxia, cells activate the transcription of genes that induce an adaptive response, which supplies oxygen to tissues. Hypoxia and hypoxia-inducible factors (HIFs may contribute to the maintenance of putative cancer stem cells, which can continue self-renewal indefinitely and express stemness genes in hypoxic stress environments (stem cell niches. Reactive oxygen species (ROS have long been recognized as toxic by-products of aerobic metabolism that are harmful to living cells, leading to DNA damage, senescence, or cell death. HIFs may promote a cancer stem cell state, whereas the loss of HIFs induces the production of cellular ROS and activation of proteins p53 and p16Ink4a, which lead to tumor cell death and senescence. ROS seem to inhibit HIF regulation in cancer cells. By contrast, controversial data have suggested that hypoxia increases the generation of ROS, which prevents hydroxylation of HIF proteins by inducing their transcription as negative feedback. Moreover, hypoxic conditions enhance the generation of induced pluripotent stem cells (iPSCs. During reprogramming of somatic cells into a PSC state, cells attain a metabolic state typically observed in embryonic stem cells (ESCs. ESCs and iPSCs share similar bioenergetic metabolisms, including decreased mitochondrial number and activity, and induced anaerobic glycolysis. This review discusses the current knowledge regarding the emerging roles of ROS homeostasis in cellular reprogramming and the implications of hypoxic regulation in cancer development.

  11. Proteomic profiling of human keratinocytes undergoing UVB-induced alternative differentiation reveals TRIpartite Motif Protein 29 as a survival factor.

    Directory of Open Access Journals (Sweden)

    Véronique Bertrand-Vallery

    Full Text Available BACKGROUND: Repeated exposures to UVB of human keratinocytes lacking functional p16(INK-4a and able to differentiate induce an alternative state of differentiation rather than stress-induced premature senescence. METHODOLOGY/PRINCIPAL FINDINGS: A 2D-DIGE proteomic profiling of this alternative state of differentiation was performed herein at various times after the exposures to UVB. Sixty-nine differentially abundant protein species were identified by mass spectrometry, many of which are involved in keratinocyte differentiation and survival. Among these protein species was TRIpartite Motif Protein 29 (TRIM29. Increased abundance of TRIM29 following UVB exposures was validated by Western blot using specific antibody and was also further analysed by immunochemistry and by RT-PCR. TRIM29 was found very abundant in keratinocytes and reconstructed epidermis. Knocking down the expression of TRIM29 by short-hairpin RNA interference decreased the viability of keratinocytes after UVB exposure. The abundance of involucrin mRNA, a marker of late differentiation, increased concomitantly. In TRIM29-knocked down reconstructed epidermis, the presence of picnotic cells revealed cell injury. Increased abundance of TRIM29 was also observed upon exposure to DNA damaging agents and PKC activation. The UVB-induced increase of TRIM29 abundance was dependent on a PKC signaling pathway, likely PKCdelta. CONCLUSIONS/SIGNIFICANCE: These findings suggest that TRIM29 allows keratinocytes to enter a protective alternative differentiation process rather than die massively after stress.

  12. Partial sleep deprivation activates the DNA damage response (DDR) and the senescence-associated secretory phenotype (SASP) in aged adult humans.

    Science.gov (United States)

    Carroll, Judith E; Cole, Steven W; Seeman, Teresa E; Breen, Elizabeth C; Witarama, Tuff; Arevalo, Jesusa M G; Ma, Jeffrey; Irwin, Michael R

    2016-01-01

    Age-related disease risk has been linked to short sleep duration and sleep disturbances; however, the specific molecular pathways linking sleep loss with diseases of aging are poorly defined. Key cellular events seen with aging, which are thought to contribute to disease, may be particularly sensitive to sleep loss. We tested whether one night of partial sleep deprivation (PSD) would increase leukocyte gene expression indicative of DNA damage responses (DDR), the senescence-associated secretory phenotype (SASP), and senescence indicator p16(INK4a) in older adult humans, who are at increased risk for cellular senescence. Community-dwelling older adults aged 61-86years (n=29; 48% male) underwent an experimental partial sleep deprivation (PSD) protocol over 4 nights, including adaptation, an uninterrupted night of sleep, partial sleep deprivation (sleep restricted 3-7AM), and a subsequent full night of sleep. Blood samples were obtained each morning to assess peripheral blood mononuclear cell (PBMC) gene expression using Illumina HT-12 arrays. Analyses of microarray results revealed that SASP (psleep deprivation activates PBMC gene expression patterns consistent with biological aging in this older adult sample. PSD enhanced the SASP and increased the accumulation of damage that initiates cell cycle arrest and promotes cellular senescence. These findings causally link sleep deprivation to the molecular processes associated with biological aging. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. A diagnostic algorithm for atypical spitzoid tumors: guidelines for immunohistochemical and molecular assessment.

    Science.gov (United States)

    Cho-Vega, Jeong Hee

    2016-07-01

    Atypical spitzoid tumors are a morphologically diverse group of rare melanocytic lesions most frequently seen in children and young adults. As atypical spitzoid tumors bear striking resemblance to Spitz nevus and spitzoid melanomas clinically and histopathologically, it is crucial to determine its malignant potential and predict its clinical behavior. To date, many researchers have attempted to differentiate atypical spitzoid tumors from unequivocal melanomas based on morphological, immonohistochemical, and molecular diagnostic differences. A diagnostic algorithm is proposed here to assess the malignant potential of atypical spitzoid tumors by using a combination of immunohistochemical and cytogenetic/molecular tests. Together with classical morphological evaluation, this algorithm includes a set of immunohistochemistry assays (p16(Ink4a), a dual-color Ki67/MART-1, and HMB45), fluorescence in situ hybridization (FISH) with five probes (6p25, 8q24, 11q13, CEN9, and 9p21), and an array-based comparative genomic hybridization. This review discusses details of the algorithm, the rationale of each test used in the algorithm, and utility of this algorithm in routine dermatopathology practice. This algorithmic approach will provide a comprehensive diagnostic tool that complements conventional histological criteria and will significantly contribute to improve the diagnosis and prediction of the clinical behavior of atypical spitzoid tumors.

  14. Tissue depletion of taurine accelerates skeletal muscle senescence and leads to early death in mice.

    Directory of Open Access Journals (Sweden)

    Takashi Ito

    Full Text Available Taurine (2-aminoethanesulfonic acid is found in milimolar concentrations in mammalian tissues. One of its main functions is osmoregulation; however, it also exhibits cytoprotective activity by diminishing injury caused by stress and disease. Taurine depletion is associated with several defects, many of which are found in the aging animal, suggesting that taurine might exert anti-aging actions. Therefore, in the present study, we examined the hypothesis that taurine depletion accelerates aging by reducing longevity and accelerating aging-associated tissue damage. Tissue taurine depletion in taurine transporter knockout (TauTKO mouse was found to shorten lifespan and accelerate skeletal muscle histological and functional defects, including an increase in central nuclei containing myotubes, a reduction in mitochondrial complex 1 activity and an induction in an aging biomarker, Cyclin-dependent kinase 4 inhibitor A (p16INK4a. Tissue taurine depletion also enhances unfolded protein response (UPR, which may be associated with an improvement in protein folding by taurine. Our data reveal that tissue taurine depletion affects longevity and cellular senescence; an effect possibly linked to a disturbance in protein folding.

  15. Cytoplasmic sequestration of cyclin D1 associated with cell cycle withdrawal of neuroblastoma cells

    International Nuclear Information System (INIS)

    Sumrejkanchanakij, Piyamas; Eto, Kazuhiro; Ikeda, Masa-Aki

    2006-01-01

    The regulation of D-type cyclin-dependent kinase activity is critical for neuronal differentiation and apoptosis. We recently showed that cyclin D1 is sequestered in the cytoplasm and that its nuclear localization induces apoptosis in postmitotic primary neurons. Here, we further investigated the role of the subcellular localization of cyclin D1 in cell cycle withdrawal during the differentiation of N1E-115 neuroblastoma cells. We show that cyclin D1 became predominantly cytoplasmic after differentiation. Targeting cyclin D1 expression to the nucleus induced phosphorylation of Rb and cdk2 kinase activity. Furthermore, cyclin D1 nuclear localization promoted differentiated N1E-115 cells to reenter the cell cycle, a process that was inhibited by p16 INK4a , a specific inhibitor of D-type cyclin activity. These results indicate that cytoplasmic sequestration of cyclin D1 plays a role in neuronal cell cycle withdrawal, and suggests that the abrogation of machinery involved in monitoring aberrant nuclear cyclin D1 activity contributes to neuronal tumorigenesis

  16. ATM-deficiency increases genomic instability and metastatic potential in a mouse model of pancreatic cancer.

    Science.gov (United States)

    Drosos, Yiannis; Escobar, David; Chiang, Ming-Yi; Roys, Kathryn; Valentine, Virginia; Valentine, Marc B; Rehg, Jerold E; Sahai, Vaibhav; Begley, Lesa A; Ye, Jianming; Paul, Leena; McKinnon, Peter J; Sosa-Pineda, Beatriz

    2017-09-11

    Germline mutations in ATM (encoding the DNA-damage signaling kinase, ataxia-telangiectasia-mutated) increase Familial Pancreatic Cancer (FPC) susceptibility, and ATM somatic mutations have been identified in resected human pancreatic tumors. Here we investigated how Atm contributes to pancreatic cancer by deleting this gene in a murine model of the disease expressing oncogenic Kras (Kras G12D ). We show that partial or total ATM deficiency cooperates with Kras G12D to promote highly metastatic pancreatic cancer. We also reveal that ATM is activated in pancreatic precancerous lesions in the context of DNA damage and cell proliferation, and demonstrate that ATM deficiency leads to persistent DNA damage in both precancerous lesions and primary tumors. Using low passage cultures from primary tumors and liver metastases we show that ATM loss accelerates Kras-induced carcinogenesis without conferring a specific phenotype to pancreatic tumors or changing the status of the tumor suppressors p53, p16 Ink4a and p19 Arf . However, ATM deficiency markedly increases the proportion of chromosomal alterations in pancreatic primary tumors and liver metastases. More importantly, ATM deficiency also renders murine pancreatic tumors highly sensitive to radiation. These and other findings in our study conclusively establish that ATM activity poses a major barrier to oncogenic transformation in the pancreas via maintaining genomic stability.

  17. Reparative Spheroids in HPV-Associated Chronic Cervicitis

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    Gennadiy T. Sukhikh

    2013-09-01

    Full Text Available Background: Spheroid cell structures (SCS described in cell culture are used to study cell-cell and cell-matrix interactions. However, the role of the SCS in the repair process in vivo remains unexplored. The aim of the study was to examine the cellular composition of the spherical structures and their functional significance in the repair of the squamous epithelium in human papilloma virus-associated chronic cervicitis (HPV-CC. Methods and Results: The cytology and biopsy materials from 223 patients with HPV-CC were subjected to molecular testing for HPV DNA by Real-Time Polymerase Chain Reaction (Real-Time PCR with genotyping and chromogenic in situ hybridization (CISH, as well as immunocytological and immunohistochemical analyses of p16INK4A, Ki67, SMA, Vimentin, CD34, E-cadherin, Oct4, CD44, CKW markers. In the stem cell niche zone, these spheroid structures were discovered having proliferative activity and showing signs of producing stem cells involved in the repair of the cervical mucosa in HPV-CC. Conclusion: The persistence of the HPV in the stem cell niche zone cells in the cervix determines the chronization of inflammation in this area, with the ability to perform pathological repair. The immunophenotype of the spheroid cell structures in the HPV-CC includes cells with signs of stem cells (‘stemness’ and the mesenchymal-epithelial transition.

  18. Bmi1 is down-regulated in the aging brain and displays antioxidant and protective activities in neurons.

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    Mohamed Abdouh

    Full Text Available Aging increases the risk to develop several neurodegenerative diseases, although the underlying mechanisms are poorly understood. Inactivation of the Polycomb group gene Bmi1 in mice results in growth retardation, cerebellar degeneration, and development of a premature aging-like phenotype. This progeroid phenotype is characterized by formation of lens cataracts, apoptosis of cortical neurons, and increase of reactive oxygen species (ROS concentrations, owing to p53-mediated repression of antioxidant response (AOR genes. Herein we report that Bmi1 expression progressively declines in the neurons of aging mouse and human brains. In old brains, p53 accumulates at the promoter of AOR genes, correlating with a repressed chromatin state, down-regulation of AOR genes, and increased oxidative damages to lipids and DNA. Comparative gene expression analysis further revealed that aging brains display an up-regulation of the senescence-associated genes IL-6, p19(Arf and p16(Ink4a, along with the pro-apoptotic gene Noxa, as seen in Bmi1-null mice. Increasing Bmi1 expression in cortical neurons conferred robust protection against DNA damage-induced cell death or mitochondrial poisoning, and resulted in suppression of ROS through activation of AOR genes. These observations unveil that Bmi1 genetic deficiency recapitulates aspects of physiological brain aging and that Bmi1 over-expression is a potential therapeutic modality against neurodegeneration.

  19. The Wnt receptor, Lrp5, is expressed by mouse mammary stem cells and is required to maintain the basal lineage.

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    Nisha M Badders

    2009-08-01

    Full Text Available Ectopic Wnt signaling induces increased stem/progenitor cell activity in the mouse mammary gland, followed by tumor development. The Wnt signaling receptors, Lrp5/6, are uniquely required for canonical Wnt activity. Previous data has shown that the absence of Lrp5 confers resistance to Wnt1-induced tumor development.Here, we show that all basal mammary cells express Lrp5, and co-express Lrp6 in a similar fashion. Though Wnt dependent transcription of key target genes is relatively unchanged in mammary epithelial cell cultures, the absence of Lrp5 specifically depletes adult regenerative stem cell activity (to less than 1%. Stem cell activity can be enriched by >200 fold (over 80% of activity, based on high Lrp5 expression alone. Though Lrp5 null glands have apparent normal function, the basal lineage is relatively reduced (from 42% basal/total epithelial cells to 22% and Lrp5-/- mammary epithelial cells show enhanced expression of senescence-associated markers in vitro, as measured by expression of p16(Ink4a and TA-p63.This is the first single biomarker that has been demonstrated to be functionally involved in stem cell maintenance. Together, these results demonstrate that Wnt signaling through Lrp5 is an important component of normal mammary stem cell function.

  20. GFAP-Cre-mediated transgenic activation of Bmi1 results in pituitary tumors.

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    Bart A Westerman

    Full Text Available Bmi1 is a member of the polycomb repressive complex 1 and plays different roles during embryonic development, depending on the developmental context. Bmi1 over expression is observed in many types of cancer, including tumors of astroglial and neural origin. Although genetic depletion of Bmi1 has been described to result in tumor inhibitory effects partly through INK4A/Arf mediated senescence and apoptosis and also through INK4A/Arf independent effects, it has not been proven that Bmi1 can be causally involved in the formation of these tumors. To see whether this is the case, we developed two conditional Bmi1 transgenic models that were crossed with GFAP-Cre mice to activate transgenic expression in neural and glial lineages. We show here that these mice generate intermediate and anterior lobe pituitary tumors that are positive for ACTH and beta-endorphin. Combined transgenic expression of Bmi1 together with conditional loss of Rb resulted in pituitary tumors but was insufficient to induce medulloblastoma therefore indicating that the oncogenic function of Bmi1 depends on regulation of p16(INK4A/Rb rather than on regulation of p19(ARF/p53. Human pituitary adenomas show Bmi1 overexpression in over 50% of the cases, which indicates that Bmi1 could be causally involved in formation of these tumors similarly as in our mouse model.

  1. Two Distinct Pathways to Development of Squamous Cell Carcinoma of the Vulva

    International Nuclear Information System (INIS)

    Ueda, Y.; Enomoto, T.; Kimura, T.; Yoshino, K.; Fujita, M.; Kimura, T.

    2011-01-01

    Squamous cell carcinoma (SCC) accounts for approximately 95% of the malignant tumors of the vaginal vulva and is mostly found in elderly women. The future numbers of patients with vulva r SCC is expected to rise, mainly because of the proportional increase in the average age of the general population. Two different pathways for vulva r SCC have been put forth. The first pathway is triggered by infection with a high-risk-type Human Papillomavirus (HPV). Integration of the HPV DNA into the host genome leads to the development of a typical vulva r intraepithelial neoplasia (VIN), accompanied with overexpression ofP14"ARF and P16"INK4A . This lesion subsequently forms a warty- or basaloid-type SCC. The HPV vaccine is a promising new tool for prevention of this HPV related SCC of the vulva. The second pathway is HPV-independent. Keratinizing SCC develops within a background of lichen sclerosus (LS) through a differentiated VIN. It has a different set of genetic alterations than those in the first pathway, including p53 mutations, allelic imbalances (AI), and microsatellite instability (MSI). Further clinical and basic research is still required to understand and prevent vulvar SCC. Capsule. Two pathway for pathogenesis of squamous cell carcinoma of the value are reviewed.

  2. Two Distinct Pathways to Development of Squamous Cell Carcinoma of the Vulva

    Directory of Open Access Journals (Sweden)

    Yutaka Ueda

    2011-01-01

    Full Text Available Squamous cell carcinoma (SCC accounts for approximately 95% of the malignant tumors of the vaginal vulva and is mostly found in elderly women. The future numbers of patients with vulvar SCC is expected to rise, mainly because of the proportional increase in the average age of the general population. Two different pathways for vulvar SCC have been put forth. The first pathway is triggered by infection with a high-risk-type Human Papillomavirus (HPV. Integration of the HPV DNA into the host genome leads to the development of a typical vulvar intraepithelial neoplasia (VIN, accompanied with overexpression of p14ARF and p16INK4A. This lesion subsequently forms a warty- or basaloid-type SCC. The HPV vaccine is a promising new tool for prevention of this HPV related SCC of the vulva. The second pathway is HPV-independent. Keratinizing SCC develops within a background of lichen sclerosus (LS through a differentiated VIN. It has a different set of genetic alterations than those in the first pathway, including p53 mutations, allelic imbalances (AI, and microsatellite instability (MSI. Further clinical and basic research is still required to understand and prevent vulvar SCC. Capsule. Two pathway for pathogenesis of squamous cell carcinoma of the value are reviewed.

  3. Precursors and preinvasive lesions of the breast: the role of molecular prognostic markers in the diagnostic and therapeutic dilemma

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    Zografos George C

    2007-05-01

    Full Text Available Abstract Precursors and preinvasive lesions of the breast include atypical ductal hyperplasia (ADH, ductal carcinoma in situ (DCIS, and lobular neoplasia (LN. There is a significant debate regarding the classification, diagnosis, prognosis and management of these lesions. This review article describes the current theories regarding the pathogenesis and molecular evolution of these lesions. It reviews the implication of a variety of molecules in the continuum of breast lesions: estrogen receptors (ER-alpha and ER-beta, c-erb-B2 (Her2/neu, p53, Ki-67, bcl-2, E-cadherin, transforming growth factor-beta (TGF-beta, p27 (Kip1, p16 (INK4a, p21 (Waf1, vascular endothelial growth factor (VEGF. With respect to the aforementioned molecules, this article reviews their pathophysiological importance, and puts the stress on whether they confer additional risk for invasive breast cancer or not. This knowledge has the potential to be of importance in the therapeutic decisions presenting in the common clinical practice.

  4. Stepwise DNA Methylation Changes Are Linked to Escape from Defined Proliferation Barriers and Mammary Epithelial Cell Immortalization

    Energy Technology Data Exchange (ETDEWEB)

    Novak, Petr; Jensen, Taylor J.; Garbe, James C.; Stampfer, Martha R.; Futscher, Bernard W.

    2009-04-20

    The timing and progression of DNA methylation changes during carcinogenesis are not completely understood. To develop a timeline of aberrant DNA methylation events during malignant transformation, we analyzed genome-wide DNA methylation patterns in an isogenic human mammary epithelial cell (HMEC) culture model of transformation. To acquire immortality and malignancy, the cultured finite lifespan HMEC must overcome two distinct proliferation barriers. The first barrier, stasis, is mediated by the retinoblastoma protein and can be overcome by loss of p16(INK4A) expression. HMEC that escape stasis and continue to proliferate become genomically unstable before encountering a second more stringent proliferation barrier, telomere dysfunction due to telomere attrition. Rare cells that acquire telomerase expression may escape this barrier, become immortal, and develop further malignant properties. Our analysis of HMEC transitioning from finite lifespan to malignantly transformed showed that aberrant DNA methylation changes occur in a stepwise fashion early in the transformation process. The first aberrant DNA methylation step coincides with overcoming stasis, and results in few to hundreds of changes, depending on how stasis was overcome. A second step coincides with immortalization and results in hundreds of additional DNA methylation changes regardless of the immortalization pathway. A majority of these DNA methylation changes are also found in malignant breast cancer cells. These results show that large-scale epigenetic remodeling occurs in the earliest steps of mammary carcinogenesis, temporally links DNA methylation changes and overcoming cellular proliferation barriers, and provides a bank of potential epigenetic biomarkers that mayprove useful in breast cancer risk assessment.

  5. Whether to target single or multiple CDKs for therapy? That is the question.

    Science.gov (United States)

    Węsierska-Gądek, Józefa; Maurer, Margarita; Zulehner, Nora; Komina, Oxana

    2011-02-01

    Complexes consisting of cyclin-dependent kinases (CDKs) and their regulatory subunits (the cyclins) control the progression of normal mammalian cells through the cell cycle. However, during malignant transformation this regulatory apparatus malfunctions, allowing cells to undergo unchecked proliferation. In many cases, the high mitotic potential of malignant cells is due to the constitutive activation of CDK-cyclin complexes, facilitated by the inactivation of cellular CDK inhibitors, such as p16(INK4A) or p27(Kip1), and the loss of functional tumor suppressors, such as the p53 and pRb proteins. It has recently been suggested that pharmacological intervention based on remedying the deficiency or loss of activity of these negative regulators of the cell cycle could be a very effective therapeutic option in the treatment of cancer. Multiple CDK inhibitors have been synthesized over the last two decades, spanning at least five classes of compounds. While these inhibitors can be classified on the basis of their chemical structure, it may be more interesting to categorize them according to their pharmacological nature, as broad-spectrum unspecific, pan-specific, or very selective antagonists. This review offers a critical assessment of the advantages and disadvantages of both pan-specific and highly selective CDK inhibitors in therapy. © 2010 Wiley-Liss, Inc.

  6. Alteration of keratinocyte differentiation and senescence by the tumor promoter dioxin

    International Nuclear Information System (INIS)

    Ray, Soma S.; Swanson, Hollie I.

    2003-01-01

    Exposure to the environmental contaminant dioxin, elicits a variety of responses, which includes tumor promotion, embryotoxicity/teratogenesis, and carcinogenesis in both animals and humans. Many of the effects of dioxin are mediated by the aryl hydrocarbon receptor (AHR), a ligand-activated bHLH (basic helix-loop-helix)/PAS transcription factor. We initiated this study to determine whether dioxin's tumor-promoting activities may lie in its ability to alter proliferation, differentiation, and/or senescence using normal human epidermal keratinocytes (HEKs). Here, we report that dioxin appears to accelerate differentiation as measured by flow cytometry and by increased expression of the differentiation markers involucrin and filaggrin. In addition, dioxin appears to increase proliferation as indicated by an increase in NADH/NADPH production and changes in cell cycle. Finally, dioxin decreases SA (senescence associated) β-galactosidase staining, an indicator of senescence, in the differentiating keratinocytes. These changes were accompanied by decreases in the expression levels of key cell cycle regulatory proteins p53, p16 INK4a , and p14 ARF . Our findings support the idea that dioxin may exert its tumor-promoting actions, in part, by downregulating the expression levels of key tumor suppressor proteins, which may impair the cell's ability to maintain its appropriate cellular status

  7. Interaction with CCNH/CDK7 facilitates CtBP2 promoting esophageal squamous cell carcinoma (ESCC) metastasis via upregulating epithelial-mesenchymal transition (EMT) progression.

    Science.gov (United States)

    Zhang, Jianguo; Zhu, Junya; Yang, Lei; Guan, Chengqi; Ni, Runzhou; Wang, Yuchan; Ji, Lili; Tian, Ye

    2015-09-01

    CtBP2, as a transcriptional corepressor of epithelial-specific genes, has been reported to promote tumor due to upregulating epithelial-mesenchymal transition (EMT) in cancer cells. CtBP2 was also demonstrated to contribute to the proliferation of esophageal squamous cell carcinoma (ESCC) cells through a negative transcriptional regulation of p16(INK4A). In this study, for the first time, we reported that CtBP2 expression, along with CCNH/CDK7, was higher in ESCC tissues with lymph node metastases than in those without lymph node metastases. Moreover, both CtBP2 and CCNH/CDK7 were positively correlated with E-cadherin, tumor grade, and tumor metastasis. However, the concrete mechanism of CtBP2's role in enhancing ESCC migration remains incompletely understood. We confirmed that CCNH/CDK7 could directly interact with CtBP2 in ESCC cells in vivo and in vitro. Furthermore, our data demonstrate for the first time that CtBP2 enhanced the migration of ESCC cells in a CCNH/CDK7-dependent manner. Our results indicated that CCNH/CDK7-CtBP2 axis may augment ESCC cell migration, and targeting the interaction of both may provide a novel therapeutic target of ESCC.

  8. [Effect of silencing Bmi-1 expression in reversing cisplatin resistance in lung cancer cells and its mechanism].

    Science.gov (United States)

    Mao, Nan; He, Guansheng; Rao, Jinjun; Lv, Lin

    2014-06-01

    To investigate the effect of silencing Bmi-1 expression in reversing cisplatin resistance in human lung cancer cells and explore the possible mechanisms. Cisplatin-resistant A549/DDP cells with small interference RNA (siRNA)-mediated Bmi-1 expression silencing were examined for cisplatin sensitivity using MTT assay and alterations in cell cycle distribution and apoptosis with flow cytometry, and the changes in cell senescence was assessed using β-galactosidase staining. The protein expressions of Bmi-1, P14(ARF), P16(INK4a), P53, P21, Rb and ubi-H2AK119 in the cells were determined with Western blotting. A549/DDP cells showed significantly higher Bmi-1 expression than A549 cells. After siRNA-mediated Bmi-1 silencing, A549/DDP cells showed significantly enhanced cisplatin sensitivity with an increased IC50 from 40.3±4.1 µmol/L to 18.3±2.8 µmol/L (Pcisplatin possibly by regulating INK4a/ARF/Rb senescence pathway.

  9. Hhex Regulates Hematopoietic Stem Cell Self-Renewal and Stress Hematopoiesis via Repression of Cdkn2a.

    Science.gov (United States)

    Jackson, Jacob T; Shields, Benjamin J; Shi, Wei; Di Rago, Ladina; Metcalf, Donald; Nicola, Nicos A; McCormack, Matthew P

    2017-08-01

    The hematopoietically expressed homeobox transcription factor (Hhex) is important for the maturation of definitive hematopoietic progenitors and B-cells during development. We have recently shown that in adult hematopoiesis, Hhex is dispensable for maintenance of hematopoietic stem cells (HSCs) and myeloid lineages but essential for the commitment of common lymphoid progenitors (CLPs) to lymphoid lineages. Here, we show that during serial bone marrow transplantation, Hhex-deleted HSCs are progressively lost, revealing an intrinsic defect in HSC self-renewal. Moreover, Hhex-deleted mice show markedly impaired hematopoietic recovery following myeloablation, due to a failure of progenitor expansion. In vitro, Hhex-null blast colonies were incapable of replating, implying a specific requirement for Hhex in immature progenitors. Transcriptome analysis of Hhex-null Lin - Sca + Kit + cells showed that Hhex deletion leads to derepression of polycomb repressive complex 2 (PRC2) and PRC1 target genes, including the Cdkn2a locus encoding the tumor suppressors p16 Ink 4 a and p19 Arf . Indeed, loss of Cdkn2a restored the capacity of Hhex-null blast colonies to generate myeloid progenitors in vitro, as well as hematopoietic reconstitution following myeloablation in vivo. Thus, HSCs require Hhex to promote PRC2-mediated Cdkn2a repression to enable continued self-renewal and response to hematopoietic stress. Stem Cells 2017;35:1948-1957. © 2017 AlphaMed Press.

  10. Presenting symptoms and clinical findings in HPV-positive and HPV-negative oropharyngeal cancer patients.

    Science.gov (United States)

    Carpén, Timo; Sjöblom, Anni; Lundberg, Marie; Haglund, Caj; Markkola, Antti; Syrjänen, Stina; Tarkkanen, Jussi; Mäkitie, Antti; Hagström, Jaana; Mattila, Petri

    2018-05-01

    Oropharyngeal squamous cell carcinoma (OPSCC) is divided in two different disease entities depending on HPV involvement. We investigated differences in presenting symptoms and clinical findings in patients with HPV-positive and -negative OPSCC tumors. Altogether 118 consecutive patients diagnosed with primary OPSCC between 2012 and 2014 at the Helsinki University Hospital were included. HPV-status of the tumors was assessed by PCR detection of HPV DNA and immunostaining with p16-INK4a antibody. Fifty-one (47.7%) of the patients had HPV-positive and 56 (52.3%) HPV-negative tumors. Forty-nine (49/51, 96.1%) of the HPV+ tumors were also p16+ showing high concordance. The most common presenting symptom among HPV+/p16+ patients was a neck mass (53.1%), whereas any sort of pain in the head and neck area was more frequently related to the HPV-/p16- (60.0%) group. HPV+/p16+ tumors had a tendency to locate in the tonsillar complex and more likely had already spread into regional lymph nodes compared with HPV-/p16- tumors. Smoking and heavy alcohol consumption were significantly more common among HPV-/p16- patients but also rather common among HPV+/p16+ patients. This analysis of symptoms and signs confirm that OPSCC can be dichotomized in two distinct disease entities as defined by HPV status.

  11. Evidence of extra-telomeric effects of hTERT and its regulation involving a feedback loop

    International Nuclear Information System (INIS)

    Lai, Serene R.; Cunningham, Amanda P.; Huynh, Vu Q.; Andrews, Lucy G.; Tollefsbol, Trygve O.

    2007-01-01

    The human telomerase reverse transcriptase (hTERT) is the catalytic subunit of the enzyme telomerase which is responsible for telomeric maintenance and extension. Using RNA interference to knock down hTERT mRNA expression, we provide evidence that hTERT exerts extra-telomeric effects on the cell cycle and on its own regulatory proteins, specifically: p53 and p21. We tested our hypothesis that hTERT regulates its own expression through effects on upstream regulatory genes using transformed human embryonic kidney (HEK 293) cells, p53 and p16 INK4a null human ovarian cancer SKOV-3 cells, and p53-null MDA-MB-157 human mammary cancer cells. In HEK 293 cells, hTERT knockdown resulted in elevated p53 and p21 transcription and a decrease in cellular proliferation. Similar results were observed in the MDA-MB-157 cell line where p21 was upregulated, correlating with cell growth inhibition. In contrast, we observed a decrease in expression of p21 in SKOV-3 cells with hTERT knockdown and cell growth appeared to be unaffected. These findings suggest that hTERT may be involved in a feedback loop system, thereby playing a role in its own regulation

  12. MiR-218-targeting-Bmi-1 mediates the suppressive effect of 1,6,7-trihydroxyxanthone on liver cancer cells.

    Science.gov (United States)

    Fu, Wei-Ming; Tang, Li-Peng; Zhu, Xiao; Lu, Ying-Fei; Zhang, Yan-Ling; Lee, Wayne Yuk-Wai; Wang, Hua; Yu, Yang; Liang, Wei-Cheng; Ko, Chun-Hay; Xu, Hong-Xi; Kung, Hsiang-Fu; Zhang, Jin-Fang

    2015-01-01

    Traditional Chinese medicine is recently emerged as anti-cancer therapy or adjuvant with reduced side-effects and improved quality of life. In the present study, an active ingredient, 1,6,7-trihydroxyxanthone (THA), derived from Goodyera oblongifolia was found to strongly suppress cell growth and induce apoptosis in liver cancer cells. MicroRNAs are a group of small non-coding RNAs that regulate gene expression at post-transcriptional levels. Our results demonstrated that miR-218 was up-regulated and oncogene Bmi-1 was down-regulated by THA treatment. Further investigation showed that THA-induced-miR-218 up-regulation could lead to activation of tumor suppressor P16(Ink4a) and P14(ARF), the main down-stream targets of Bmi-1. In conclusion, THA might be a potential anti-cancer drug candidate, at least in part, through the activation of miR-218 and suppression of Bmi-1 expression.

  13. Role of Protein Biomarkers in the Detection of High-Grade Disease in Cervical Cancer Screening Programs

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    Charlotte A. Brown

    2012-01-01

    Full Text Available Since the Pap test was introduced in the 1940s, there has been an approximately 70% reduction in the incidence of squamous cell cervical cancers in many developed countries by the application of organized and opportunistic screening programs. The efficacy of the Pap test, however, is hampered by high interobserver variability and high false-negative and false-positive rates. The use of biomarkers has demonstrated the ability to overcome these issues, leading to improved positive predictive value of cervical screening results. In addition, the introduction of HPV primary screening programs will necessitate the use of a follow-up test with high specificity to triage the high number of HPV-positive tests. This paper will focus on protein biomarkers currently available for use in cervical cancer screening, which appear to improve the detection of women at greatest risk for developing cervical cancer, including Ki-67, p16INK4a, BD ProEx C, and Cytoactiv HPV L1.

  14. Bmi1 regulates murine intestinal stem cell proliferation and self-renewal downstream of Notch.

    Science.gov (United States)

    López-Arribillaga, Erika; Rodilla, Verónica; Pellegrinet, Luca; Guiu, Jordi; Iglesias, Mar; Roman, Angel Carlos; Gutarra, Susana; González, Susana; Muñoz-Cánoves, Pura; Fernández-Salguero, Pedro; Radtke, Freddy; Bigas, Anna; Espinosa, Lluís

    2015-01-01

    Genetic data indicate that abrogation of Notch-Rbpj or Wnt-β-catenin pathways results in the loss of the intestinal stem cells (ISCs). However, whether the effect of Notch is direct or due to the aberrant differentiation of the transit-amplifying cells into post-mitotic goblet cells is unknown. To address this issue, we have generated composite tamoxifen-inducible intestine-specific genetic mouse models and analyzed the expression of intestinal differentiation markers. Importantly, we found that activation of β-catenin partially rescues the differentiation phenotype of Rbpj deletion mutants, but not the loss of the ISC compartment. Moreover, we identified Bmi1, which is expressed in the ISC and progenitor compartments, as a gene that is co-regulated by Notch and β-catenin. Loss of Bmi1 resulted in reduced proliferation in the ISC compartment accompanied by p16(INK4a) and p19(ARF) (splice variants of Cdkn2a) accumulation, and increased differentiation to the post-mitotic goblet cell lineage that partially mimics Notch loss-of-function defects. Finally, we provide evidence that Bmi1 contributes to ISC self-renewal. © 2015. Published by The Company of Biologists Ltd.

  15. Colorectal Cancer "Methylator Phenotype": Fact or Artifact?

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    Charles Anacleto

    2005-04-01

    Full Text Available It has been proposed that human colorectal tumors can be classified into two groups: one in which methylation is rare, and another with methylation of several loci associated with a "CpG island methylated phenotype (CIMP," characterized by preferential proximal location in the colon, but otherwise poorly defined. There is considerable overlap between this putative methylator phenotype and the well-known mutator phenotype associated with microsatellite instability (MSI. We have examined hypermethylation of the promoter region of five genes (DAPK, MGMT, hMLH1, p16INK4a, and p14ARF in 106 primary colorectal cancers. A graph depicting the frequency of methylated loci in the series of tumors showed a continuous, monotonically decreasing distribution quite different from the previously claimed discontinuity. We observed a significant association between the presence of three or more methylated loci and the proximal location of the tumors. However, if we remove from analysis the tumors with hMLH1 methylation or those with MSI, the significance vanishes, suggesting that the association between multiple methylations and proximal location was indirect due to the correlation with MSI. Thus, our data do not support the independent existence of the so-called methylator phenotype and suggest that it rather may represent a statistical artifact caused by confounding of associations.

  16. Prognostic and Predictive Value of CpG Island Methylator Phenotype in Patients with Locally Advanced Nonmetastatic Sporadic Colorectal Cancer

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    Yuwei Wang

    2014-01-01

    Full Text Available Purpose. In the present study, the prognostic significance of CpG island methylator phenotype (CIMP in stage II/III sporadic colorectal cancer was evaluated using a five-gene panel. Methods. Fifty stage II/III colorectal cancer patients who received radical resection were included in this study. Promoter methylation of p14ARF, hMLH1, p16INK4a, MGMT, and MINT1 was determined by methylation specific polymerase chain reaction (MSP. CIMP positive was defined as hypermethylation of three or more of the five genes. Impact factors on disease-free survival (DFS and overall survival (OS were analyzed using Kaplan-Meier method (log-rank test and adjusted Cox proportional hazards model. Results. Twenty-four percent (12/50 of patients were characterized as CIMP positive. Univariate analysis showed stage III (P=0.049 and CIMP positive (P=0.014 patients who had significantly inferior DFS. In Cox regression analysis, CIMP positive epigenotype was independently related with poor DFS with HR = 2.935 and 95% CI: 1.193–7.220 (P=0.019. In patients with CIMP positive tumor, those receiving adjuvant chemotherapy had a poor DFS than those without adjuvant chemotherapy (P=0.023. Conclusions. CIMP positive was significantly correlated with decreased DFS in stage II/III colorectal cancer. Patients with CIMP positive locally advanced sporadic colorectal cancers may not benefit from 5-fluorouracil based adjuvant chemotherapy.

  17. Inhibition of JAK1, 2/STAT3 Signaling Induces Apoptosis, Cell Cycle Arrest, and Reduces Tumor Cell Invasion in Colorectal Cancer Cells

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    Hua Xiong

    2008-03-01

    Full Text Available Abnormalities in the STAT3 pathway are involved in the oncogenesis of several cancers. However, the mechanism by which dysregulated STAT3 signaling contributes to the progression of human colorectal cancer (CRC has not been elucidated, nor has the role of JAK, the physiological activator of STAT3, been evaluated. To investigate the role of both JAK and STAT3 in CRC progression, we inhibited JAK with AG490 and depleted STAT3 with a SiRNA. Our results demonstrate that STAT3 and both JAK1 and 2 are involved in CRC cell growth, survival, invasion, and migration through regulation of gene expression, such as Bcl-2, p16ink4a, p21waf1/cip1, p27kip1, E-cadherin, VEGF, and MMPs. Importantly, the FAK is not required for STAT3-mediated regulation, but does function downstream of JAK. In addition, our data show that proteasome-mediated proteolysis promotes dephosphorylation of the JAK2, and consequently, negatively regulates STAT3 signaling in CRC. Moreover, immunohistochemical staining reveals that nuclear staining of phospho-STAT3 mostly presents in adenomas and adenocarcinomas, and a positive correlation is found between phospho-JAK2 immunoreactivity and the differentiation of colorectal adenocarcinomas. Therefore, our findings illustrate the biologic significance of JAK1, 2/STAT3 signaling in CRC progression and provide novel evidence that the JAK/STAT3 pathway may be a new potential target for therapy of CRC.

  18. Expression of Anion Exchanger 1 Sequestrates p16 in the Cytoplasm in Gastric, Colonic Adenocarcinoma

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    Wei-Wei Shen

    2007-10-01

    Full Text Available p16INK4A (p16 binds to cyclin-dependent kinase 4/6, negatively regulates cell growth. Recent studies have led to an understanding of additional biologic functions for p16; however, the detailed mechanisms involved are still elusive. In this article, we show an unexpected expression of anion exchanger 1 (AEi in the cytoplasm in poorly, moderately differentiated gastric, colonic adenocarcinoma cells, in its interaction with p16, thereby sequestrating the protein in the cytoplasm. Genetic alterations of p16, AEi were not detectable. Forced expression of AEi in these cells sequestrated more p16 in the cytoplasm, whereas small interfering RNA-mediated silencing of AEi in the cells induced the release of p16 from the cytoplasm to the nucleus, leading to cell death, growth inhibition of tumor cells. By analyzing tissue samples obtained from patients with gastric, colonic cancers, we found that 83.33% of gastric cancers, 56.52% of colonic cancers coexpressed AEi, p16 in the cytoplasm. We conclude that AEi plays a crucial role in the pathogenesis of gastric, colonic adenocarcinoma, that p16 dysfunction is a novel pathway of carcinogenesis.

  19. Multiple effects of TRAIL in human carcinoma cells: Induction of apoptosis, senescence, proliferation, and cytokine production

    International Nuclear Information System (INIS)

    Levina, Vera; Marrangoni, Adele M.; DeMarco, Richard; Gorelik, Elieser; Lokshin, Anna E.

    2008-01-01

    TRAIL is a death ligand that induces apoptosis in malignant but not normal cells. Recently the ability of TRAIL to induce proliferation in apoptosis-resistant normal and malignant cells was reported. In this study, we analyzed TRAIL effects in apoptosis sensitive MCF7, OVCAR3 and H460 human tumor cell lines. TRAIL at low concentrations preferentially induced cell proliferation. At 100 ng/ml, apoptotic death was readily observed, however surviving cells acquired higher proliferative capacity. TRAIL-stimulated production of several cytokines, IL-8, RANTES, MCP-1 and bFGF, and activation of caspases 1 and 8 was essential for this effect. Antibodies to IL-8, RANTES, and bFGF blocked TRAIL-induced cell proliferation and further stimulated apoptosis. For the first time, we report that high TRAIL concentrations induced cell senescence as determined by the altered morphology and expression of several senescence markers: SA-β-gal, p21 Waf1/Cip1 , p16 INK4a , and HMGA. Caspase 9 inhibition protected TRAIL-treated cells from senescence, whereas inhibition of caspases 1 and 8 increased the yield of SLP cells. In conclusion, in cultured human carcinoma cells, TRAIL therapy results in three functional outcomes, apoptosis, proliferation and senescence. TRAIL-induced proapoptotic and prosurvival responses correlate with the strength of signaling. TRAIL-induced cytokine production is responsible for its proliferative and prosurvival effects

  20. NBPF1, a tumor suppressor candidate in neuroblastoma, exerts growth inhibitory effects by inducing a G1 cell cycle arrest

    International Nuclear Information System (INIS)

    Andries, Vanessa; Vandepoele, Karl; Staes, Katrien; Berx, Geert; Bogaert, Pieter; Van Isterdael, Gert; Ginneberge, Daisy; Parthoens, Eef; Vandenbussche, Jonathan; Gevaert, Kris; Roy, Frans van

    2015-01-01

    NBPF1 (Neuroblastoma Breakpoint Family, member 1) was originally identified in a neuroblastoma patient on the basis of its disruption by a chromosomal translocation t(1;17)(p36.2;q11.2). Considering this genetic defect and the frequent genomic alterations of the NBPF1 locus in several cancer types, we hypothesized that NBPF1 is a tumor suppressor. Decreased expression of NBPF1 in neuroblastoma cell lines with loss of 1p36 heterozygosity and the marked decrease of anchorage-independent clonal growth of DLD1 colorectal carcinoma cells with induced NBPF1 expression further suggest that NBPF1 functions as tumor suppressor. However, little is known about the mechanisms involved. Expression of NBPF was analyzed in human skin and human cervix by immunohistochemistry. The effects of NBPF1 on the cell cycle were evaluated by flow cytometry. We investigated by real-time quantitative RT-PCR the expression profile of a panel of genes important in cell cycle regulation. Protein levels of CDKN1A-encoded p21 CIP1/WAF1 were determined by western blotting and the importance of p53 was shown by immunofluorescence and by a loss-of-function approach. LC-MS/MS analysis was used to investigate the proteome of DLD1 colon cancer cells with induced NBPF1 expression. Possible biological interactions between the differentially regulated proteins were investigated with the Ingenuity Pathway Analysis tool. We show that NBPF is expressed in the non-proliferative suprabasal layers of squamous stratified epithelia of human skin and cervix. Forced expression of NBPF1 in HEK293T cells resulted in a G1 cell cycle arrest that was accompanied by upregulation of the cyclin-dependent kinase inhibitor p21 CIP1/WAF1 in a p53-dependent manner. Additionally, forced expression of NBPF1 in two p53-mutant neuroblastoma cell lines also resulted in a G1 cell cycle arrest and CDKN1A upregulation. However, CDKN1A upregulation by NBPF1 was not observed in the DLD1 cells, which demonstrates that NBPF1 exerts cell

  1. Sphingosine kinase 1 is required for mesothelioma cell proliferation: role of histone acetylation.

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    Satish Kalari

    Full Text Available Malignant pleural mesothelioma (MPM is a devastating disease with an overall poor prognosis. Despite the recent advances in targeted molecular therapies, there is a clear and urgent need for the identification of novel mesothelioma targets for the development of highly efficacious therapeutics.In this study, we report that the expression of Sphingosine Kinase 1 (SphK1 protein was preferentially elevated in MPM tumor tissues (49 epithelioid and 13 sarcomatoid compared to normal tissue (n = 13. In addition, we also observed significantly elevated levels of SphK1 and SphK2 mRNA and SphK1 protein expression in MPM cell lines such as H2691, H513 and H2461 compared to the non-malignant mesothelial Met5 cells. The underlying mechanism appears to be mediated by SphK1 induced upregulation of select gene transcription programs such as that of CBP/p300 and PCAF, two histone acetyl transferases (HAT, and the down regulation of cell cycle dependent kinase inhibitor genes such as p27Kip1 and p21Cip1. In addition, using immunoprecipitates of anti-acetylated histone antibody from SphK inhibitor, SphK-I2 treated Met5A and H2691 cell lysates, we also showed activation of other cell proliferation related genes, such as Top2A (DNA replication, AKB (chromosome remodeling and mitotic spindle formation, and suppression of p21 CIP1 and p27KIP1. The CDK2, HAT1 and MYST2 were, however, unaffected in the above study. Using SphK inhibitor and specific siRNA targeting either SphK1 or SphK2, we also unequivocally established that SphK1, but not SphK2, promotes H2691 mesothelioma cell proliferation. Using a multi-walled carbon nanotubes induced peritoneal mesothelioma mouse model, we showed that the SphK1-/- null mice exhibited significantly less inflammation and granulamatous nodules compared to their wild type counterparts.The lipid kinase SphK1 plays a positive and essential role in the growth and development of malignant mesothelioma and is therefore a likely

  2. Promoter-region hypermethylation and expression downregulation of Yy1 (Yin yang 1) in preneoplastic liver lesions in a thioacetamide rat hepatocarcinogenesis model

    International Nuclear Information System (INIS)

    Abe, Hajime; Ogawa, Takashi; Wang, Liyun; Kimura, Masayuki; Tanaka, Takeshi; Morita, Reiko; Yoshida, Toshinori; Shibutani, Makoto

    2014-01-01

    Thioacetamide (TAA) has been used to develop a rodent model for hepatocarcinogenesis. To determine the genes with epigenetic modifications in early hepatocarcinogenesis, we did a genome-wide scan for hypermethylated promoter regions using CpG island microarrays in TAA-promoted rat liver tissue. Eight genes were selected based on the microarray profile; of these, Yy1 and Wdr45b were confirmed to be hypermethylated by methylation-specific polymerase chain reaction (PCR) and pyrosequencing and downregulated by real-time reverse transcription PCR. Non-neoplastic liver cells had nuclear Yy1 immunoreactivity, while preneoplastic foci with glutathione S-transferase placental form (GST-P) immunoreactivity had decreased Yy1 immunoreactivity. The incidence of these foci was proportional to the dose of TAA administered. Co-expression analysis of gene products downstream of Yy1 revealed increased nuclear phospho-c-Myc + foci as well as nuclear and cytoplasmic p21 Cip1+ foci in Yy1 − or GST-P + foci in response to TAA-promotion dose. Although the absolute number of cells was low, the incidence of death receptor 5 − foci was increased in Yy1 − foci in proportion to the TAA dose. Yy1 − /GST-P + foci revealed a higher number of proliferating cell nuclear antigen (PCNA)-immunoreactive cells than Yy1 + /GST-P + foci, while cleaved caspase-3 + cells were unchanged between Yy1 – /GST-P + and Yy1 + /GST-P + foci. In the case of Wdr45b, most GST-P + foci were Wdr45b – and were not increased by TAA promotion. These results suggest involvement of Yy1 in the epigenetic gene regulation at the early stages of TAA promoted cell proliferation and concomitant cell cycle arrest in preneoplastic lesions. - Highlights: • Epigenetically downregulated genes were searched in TAA-promnoted rat livers. • Yy1 and Wdr45b showed promoter-region hypermethylation and mRNA downregulation. • TAA promoted increase of preneoplastic Yy1 – /GST-P + foci showing high proliferation. • TAA

  3. Characterisation of cell cycle arrest and terminal differentiation in a maximally proliferative human epithelial tissue: Lessons from the human hair follicle matrix.

    Science.gov (United States)

    Purba, Talveen S; Brunken, Lars; Peake, Michael; Shahmalak, Asim; Chaves, Asuncion; Poblet, Enrique; Ceballos, Laura; Gandarillas, Alberto; Paus, Ralf

    2017-09-01

    Human hair follicle (HF) growth and hair shaft formation require terminal differentiation-associated cell cycle arrest of highly proliferative matrix keratinocytes. However, the regulation of this complex event remains unknown. CIP/KIP family member proteins (p21 CIP1 , p27 KIP1 and p57 KIP2 ) regulate cell cycle progression/arrest, endoreplication, differentiation and apoptosis. Since they have not yet been adequately characterized in the human HF, we asked whether and where CIP/KIP proteins localise in the human hair matrix and pre-cortex in relation to cell cycle activity and HF-specific epithelial cell differentiation that is marked by keratin 85 (K85) protein expression. K85 expression coincided with loss or reduction in cell cycle activity markers, including in situ DNA synthesis (EdU incorporation), Ki-67, phospho-histone H3 and cyclins A and B1, affirming a post-mitotic state of pre-cortical HF keratinocytes. Expression of CIP/KIP proteins was found abundantly within the proliferative hair matrix, concomitant with a role in cell cycle checkpoint control. p21 CIP1 , p27 KIP1 and cyclin E persisted within post-mitotic keratinocytes of the pre-cortex, whereas p57 KIP2 protein decreased but became nuclear. These data imply a supportive role for CIP/KIP proteins in maintaining proliferative arrest, differentiation and anti-apoptotic pathways, promoting continuous hair bulb growth and hair shaft formation in anagen VI. Moreover, post-mitotic hair matrix regions contained cells with enlarged nuclei, and DNA in situ hybridisation showed cells that were >2N in the pre-cortex. This suggests that CIP/KIP proteins might counterbalance cyclin E to control further rounds of DNA replication in a cell population that has a propensity to become tetraploid. These data shed new light on the in situ-biography of human hair matrix keratinocytes on their path of active cell cycling, arrest and terminal differentiation, and showcase the human HF as an excellent, clinically

  4. Conjugated docosahexaenoic acid suppresses KPL-1 human breast cancer cell growth in vitro and in vivo: potential mechanisms of action

    International Nuclear Information System (INIS)

    Tsujita-Kyutoku, Miki; Ogawa, Yutaka; Tsubura, Airo; Yuri, Takashi; Danbara, Naoyuki; Senzaki, Hideto; Kiyozuka, Yasuhiko; Uehara, Norihisa; Takada, Hideho; Hada, Takahiko; Miyazawa, Teruo

    2004-01-01

    The present study was conducted to examine the effect of conjugated docosahexaenoic acid (CDHA) on cell growth, cell cycle progression, mode of cell death, and expression of cell cycle regulatory and/or apoptosis-related proteins in KPL-1 human breast cancer cell line. This effect of CDHA was compared with that of docosahexaenoic acid (DHA). KPL-1 cell growth was assessed by colorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay; cell cycle progression and mode of cell death were examined by flow cytometry; and levels of expression of p53, p21 Cip1/Waf1 , cyclin D 1 , Bax, and Bcl-2 proteins were examined by Western blotting analysis. In vivo tumor growth was examined by injecting KPL-1 cells subcutaneously into the area of the right thoracic mammary fat pad of female athymic mice fed a CDHA diet. CDHA inhibited KPL-1 cells more effectively than did DHA (50% inhibitory concentration for 72 hours: 97 μmol/l and 270 μmol/l, respectively). With both CDHA and DHA growth inhibition was due to apoptosis, as indicated by the appearance of a sub-G 1 fraction. The apoptosis cascade involved downregulation of Bcl-2 protein; Bax expression was unchanged. Cell cycle progression was due to G 0 /G 1 arrest, which involved increased expression of p53 and p21 Cip1/Waf1 , and decreased expression of cyclin D 1 . CDHA modulated cell cycle regulatory proteins and apoptosis-related proteins in a manner similar to that of parent DHA. In the athymic mouse system 1.0% dietary CDHA, but not 0.2%, significantly suppressed growth of KPL-1 tumor cells; CDHA tended to decrease regional lymph node metastasis in a dose dependent manner. CDHA inhibited growth of KPL-1 human breast cancer cells in vitro more effectively than did DHA. The mechanisms of action involved modulation of apoptosis cascade and cell cycle progression. Dietary CDHA at 1.0% suppressed KPL-1 cell growth in the athymic mouse system

  5. Ionizing radiation-induced phosphorylation of RPA p34 is deficient in ataxia telangiectasia and reduced in aged normal fibroblasts

    International Nuclear Information System (INIS)

    Xinbo Cheng; Nge Cheong; Ya Wang; Iliakis, George

    1996-01-01

    Replication protein A (RPA, also called human single stranded DNA binding protein, hSSB) is a trimeric, multifunctional protein complex involved in DNA replication, DNA repair and recombination. Phosphorylation of RPA p34 subunit is observed after exposure of cells to radiation and other DNA damaging agents, which implicates the protein not only in repair but also in the regulation of replication on damaged DNA template. Here, we show that the phosphorylation observed in RPA p34 after exposure to ionizing radiation, X- or γ-rays, is reduced and occurs later in primary fibroblasts from patients suffering from ataxia telangiectasia (AT), as compared to normal fibroblasts. We also show that in primary normal human fibroblasts, radiation-induced phosphorylation of RPA p34 is 'age'-dependent and decreases significantly as cultures senesce. Radiation-induced phosphorylation of RPA p34 is nearly absent in non-cycling cells, while the expression of p21 cip1/waf1/sdi1 remains inducible. The results demonstrate a growth-stage and culture-age dependency in radiation-induced RPA p34 phosphorylation, and suggest the operation of a signal transduction pathway that is inactivated in senescing or quiescent fibroblasts and defective in AT cells

  6. In vivo targeting of ADAM9 gene expression using lentivirus-delivered shRNA suppresses prostate cancer growth by regulating REG4 dependent cell cycle progression.

    Directory of Open Access Journals (Sweden)

    Che-Ming Liu

    Full Text Available Cancer cells respond to stress by activating a variety of survival signaling pathways. A disintegrin and metalloproteinase (ADAM 9 is upregulated during cancer progression and hormone therapy, functioning in part through an increase in reactive oxygen species. Here, we present in vitro and in vivo evidence that therapeutic targeting of ADAM9 gene expression by lentivirus-delivered small hairpin RNA (shRNA significantly inhibited proliferation of human prostate cancer cell lines and blocked tumor growth in a murine model of prostate cancer bone metastasis. Cell cycle studies confirmed an increase in the G1-phase and decrease in the S-phase population of cancer cells under starvation stress conditions, which correlated with elevated intracellular superoxide levels. Microarray data showed significantly decreased levels of regenerating islet-derived family member 4 (REG4 expression in prostate cancer cells with knockdown of ADAM9 gene expression. This REG4 downregulation also resulted in induction of expression of p21(Cip1/WAF1, which negatively regulates cyclin D1 and blocks the G1/S transition. Our data reveal a novel molecular mechanism of ADAM9 in the regulation of prostate cancer cell proliferation, and suggests a combined modality of ADAM9 shRNA gene therapy and cytotoxic agents for hormone refractory and bone metastatic prostate cancer.

  7. Taraxinic acid, a hydrolysate of sesquiterpene lactone glycoside from the Taraxacum coreanum NAKAI, induces the differentiation of human acute promyelocytic leukemia HL-60 cells.

    Science.gov (United States)

    Choi, Jung-Hye; Shin, Kyung-Min; Kim, Na-Young; Hong, Jung-Pyo; Lee, Yong Sup; Kim, Hyoung Ja; Park, Hee-Juhn; Lee, Kyung-Tae

    2002-11-01

    The present work was performed to elucidate the active moiety of a sesquiterpene lactone, taraxinic acid-1'-O-beta-D-glucopyranoside (1). from Taraxacum coreanum NAKAI on the cytotoxicity of various cancer cells. Based on enzymatic hydrolysis and MTT assay, the active moiety should be attributed to the aglycone taraxinic acid (1a). rather than the glycoside (1). Taraxinic acid exhibited potent antiproliferative activity against human leukemia-derived HL-60. In addition, this compound was found to be a potent inducer of HL-60 cell differentiation as assessed by a nitroblue tetrazolium reduction test, esterase activity assay, phagocytic activity assay, morphology change, and expression of CD 14 and CD 66 b surface antigens. These results suggest that taraxinic acid induces the differentiation of human leukemia cells to monocyte/macrophage lineage. Moreover, the expression level of c-myc was down-regulated during taraxinic acid-dependent HL-60 cell differentiation, whereas p21(CIP1) and p27(KIP1) were up-regulated. Taken together, our results suggest that taraxinic acid may have potential as a therapeutic agent in human leukemia.

  8. PRMT7 Preserves Satellite Cell Regenerative Capacity

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    Roméo Sébastien Blanc

    2016-02-01

    Full Text Available Regeneration of skeletal muscle requires the continued presence of quiescent muscle stem cells (satellite cells, which become activated in response to injury. Here, we report that whole-body protein arginine methyltransferase PRMT7−/− adult mice and mice conditionally lacking PRMT7 in satellite cells using Pax7-CreERT2 both display a significant reduction in satellite cell function, leading to defects in regenerative capacity upon muscle injury. We show that PRMT7 is preferentially expressed in activated satellite cells and, interestingly, PRMT7-deficient satellite cells undergo cell-cycle arrest and premature cellular senescence. These defects underlie poor satellite cell stem cell capacity to regenerate muscle and self-renew after injury. PRMT7-deficient satellite cells express elevated levels of the CDK inhibitor p21CIP1 and low levels of its repressor, DNMT3b. Restoration of DNMT3b in PRMT7-deficient cells rescues PRMT7-mediated senescence. Our findings define PRMT7 as a regulator of the DNMT3b/p21 axis required to maintain muscle stem cell regenerative capacity.

  9. Protein Kinase C alpha (PKCα) dependent signaling mediates endometrial cancer cell growth and tumorigenesis

    Science.gov (United States)

    Haughian, James M.; Reno, Elaine M.; Thorne, Alicia M.; Bradford, Andrew P.

    2009-01-01

    Endometrial cancer is the most common invasive gynecologic malignancy, yet molecular mechanisms and signaling pathways underlying its etiology and pathophysiology remain poorly characterized. We sought to define a functional role for the protein kinase C (PKC) isoform, PKCα, in an established cell model of endometrial adenocarcinoma. Ishikawa cells depleted of PKCα protein grew slower, formed fewer colonies in anchorage-independent growth assays and exhibited impaired xenograft tumor formation in nude mice. Consistent with impaired growth, PKCα knockdown increased levels of the cyclin dependent kinase (CDK) inhibitors p21Cip1/WAF1 (p21) and p27Kip1 (p27). Despite the absence of functional phosphatase and tensin homologue (PTEN) protein in Ishikawa cells, PKCα knockdown reduced Akt phosphorylation at serine 473 and concomitantly inhibited phosphorylation of the Akt target, glycogen synthase kinase-3β (GSK-3β). PKCα knockdown also resulted in decreased basal ERK phosphorylation and attenuated ERK activation following EGF stimulation. p21 and p27 expression was not increased by treatment of Ishikawa cells with ERK and Akt inhibitors, suggesting PKCα regulates CDK expression independently of Akt and ERK. Immunohistochemical analysis of grade 1 endometrioid adenocarcinoma revealed aberrant PKCα expression, with foci of elevated PKCα staining, not observed in normal endometrium. These studies demonstrate a critical role for PKCα signaling in endometrial tumorigenesis by regulating expression of CDK inhibitors p21 and p27 and activation of Akt and ERK dependent proliferative pathways. Thus, targeting PKCα may provide novel therapeutic options in endometrial tumors. PMID:19672862

  10. Development of a Fish Cell Biosensor System for Genotoxicity Detection Based on DNA Damage-Induced Trans-Activation of p21 Gene Expression

    Directory of Open Access Journals (Sweden)

    Huarong Guo

    2012-09-01

    Full Text Available p21CIP1/WAF1 is a p53-target gene in response to cellular DNA damage. Here we report the development of a fish cell biosensor system for high throughput genotoxicity detection of new drugs, by stably integrating two reporter plasmids of pGL3-p21-luc (human p21 promoter linked to firefly luciferase and pRL-CMV-luc (CMV promoter linked to Renilla luciferase into marine flatfish flounder gill (FG cells, referred to as p21FGLuc. Initial validation of this genotoxicity biosensor system showed that p21FGLuc cells had a wild-type p53 signaling pathway and responded positively to the challenge of both directly acting genotoxic agents (bleomycin and mitomycin C and indirectly acting genotoxic agents (cyclophosphamide with metabolic activation, but negatively to cyclophosphamide without metabolic activation and the non-genotoxic agents ethanol and D-mannitol, thus confirming a high specificity and sensitivity, fast and stable response to genotoxic agents for this easily maintained fish cell biosensor system. This system was especially useful in the genotoxicity detection of Di(2-ethylhexyl phthalate (DEHP, a rodent carcinogen, but negatively reported in most non-mammalian in vitro mutation assays, by providing a strong indication of genotoxicity for DEHP. A limitation for this biosensor system was that it might give false positive results in response to sodium butyrate and any other agents, which can trans-activate the p21 gene in a p53-independent manner.

  11. Molecular control of brain size: Regulators of neural stem cell life, death and beyond

    International Nuclear Information System (INIS)

    Joseph, Bertrand; Hermanson, Ola

    2010-01-01

    The proper development of the brain and other organs depends on multiple parameters, including strictly controlled expansion of specific progenitor pools. The regulation of such expansion events includes enzymatic activities that govern the correct number of specific cells to be generated via an orchestrated control of cell proliferation, cell cycle exit, differentiation, cell death etc. Certain proteins in turn exert direct control of these enzymatic activities and thus progenitor pool expansion and organ size. The members of the Cip/Kip family (p21Cip1/p27Kip1/p57Kip2) are well-known regulators of cell cycle exit that interact with and inhibit the activity of cyclin-CDK complexes, whereas members of the p53/p63/p73 family are traditionally associated with regulation of cell death. It has however become clear that the roles for these proteins are not as clear-cut as initially thought. In this review, we discuss the roles for proteins of the Cip/Kip and p53/p63/p73 families in the regulation of cell cycle control, differentiation, and death of neural stem cells. We suggest that these proteins act as molecular interfaces, or 'pilots', to assure the correct assembly of protein complexes with enzymatic activities at the right place at the right time, thereby regulating essential decisions in multiple cellular events.

  12. Molecular control of brain size: Regulators of neural stem cell life, death and beyond

    Energy Technology Data Exchange (ETDEWEB)

    Joseph, Bertrand [Department of Oncology-Pathology, Cancer Centrum Karolinska (CCK), Karolinska Institutet, Stockholm (Sweden); Hermanson, Ola, E-mail: ola.hermanson@ki.se [Linnaeus Center in Developmental Biology for Regenerative Medicine (DBRM), Department of Neuroscience, Karolinska Institutet, Stockholm (Sweden)

    2010-05-01

    The proper development of the brain and other organs depends on multiple parameters, including strictly controlled expansion of specific progenitor pools. The regulation of such expansion events includes enzymatic activities that govern the correct number of specific cells to be generated via an orchestrated control of cell proliferation, cell cycle exit, differentiation, cell death etc. Certain proteins in turn exert direct control of these enzymatic activities and thus progenitor pool expansion and organ size. The members of the Cip/Kip family (p21Cip1/p27Kip1/p57Kip2) are well-known regulators of cell cycle exit that interact with and inhibit the activity of cyclin-CDK complexes, whereas members of the p53/p63/p73 family are traditionally associated with regulation of cell death. It has however become clear that the roles for these proteins are not as clear-cut as initially thought. In this review, we discuss the roles for proteins of the Cip/Kip and p53/p63/p73 families in the regulation of cell cycle control, differentiation, and death of neural stem cells. We suggest that these proteins act as molecular interfaces, or 'pilots', to assure the correct assembly of protein complexes with enzymatic activities at the right place at the right time, thereby regulating essential decisions in multiple cellular events.

  13. Simultaneous human papilloma virus type 16 E7 and cdk inhibitor p21 expression induces apoptosis and cathepsin B activation

    International Nuclear Information System (INIS)

    Kaznelson, Dorte Wissing; Bruun, Silas; Monrad, Astrid; Gjerloev, Simon; Birk, Jesper; Roepke, Carsten; Norrild, Bodil

    2004-01-01

    Human papillomavirus type 16 (HPV-16) is the major risk factor for development of cervical cancer. The major oncoprotein E7 enhances cell growth control. However, E7 has in some reports been shown to induce apoptosis suggesting that there is a delicate balance between cell proliferation and induction of cell death. We have used the osteosarcoma cell line U2OS cells provided with E7 and the cdk2 inhibitor p21 (cip1/waf1) under inducible control, as a model system for the analysis of E7-mediated apoptosis. Our data shows that simultaneous expression of E7 and p21 proteins induces cell death, possibly because of conflicting growth control. Interestingly, E7/p21-induced cell death is associated with the activation of a newly identified mediator of apoptosis, namely cathepsin B. Activation of the cellular caspases is undetectable in cells undergoing E7/p21-induced apoptosis. To our knowledge, this is the first time a role for cathepsin B is reported in HPV-induced apoptotic signalling

  14. A novel role of RASSF9 in maintaining epidermal homeostasis.

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    Chiou-Mei Lee

    Full Text Available The physiological role of RASSF9, a member of the Ras-association domain family (RASSF, is currently unclear. Here, we report a mouse line in which an Epstein-Barr virus Latent Membrane Protein 1 (LMP1 transgene insertion has created a 7.2-kb chromosomal deletion, which abolished RASSF9 gene expression. The RASSF9-null mice exhibited interesting phenotypes that resembled human ageing, including growth retardation, short lifespan, less subcutaneous adipose layer and alopecia. In the wild-type mice, RASSF9 is predominantly expressed in the epidermal keratinocytes of skin, as determined by quantitative reverse-transcription PCR, immunofluorescence and in situ hybridization. In contrast, RASSF9-/- mice presented a dramatic change in epithelial organization of skin with increased proliferation and aberrant differentiation as detected by bromodeoxyuridine incorporation assays and immunofluorescence analyses. Furthermore, characteristic functions of RASSF9-/- versus wild type (WT mouse primary keratinocytes showed significant proliferation linked to a reduction of p21Cip1 expression under growth or early differentiation conditions. Additionally, in RASSF9-/- keratinocytes there was a drastic down-modulation of terminal differentiation markers, which could be rescued by infection with a recombinant adenovirus, Adv/HA-RASSF9. Our results indicate a novel and significant role of RASSF9 in epidermal homeostasis.

  15. Involvement of apoptotic cell death and cell cycle perturbation in retinoic acid-induced cleft palate in mice

    International Nuclear Information System (INIS)

    Okano, Junko; Suzuki, Shigehiko; Shiota, Kohei

    2007-01-01

    Retinoic acid (RA), a metabolite of vitamin A, plays a key role in a variety of biological processes and is essential for normal embryonic development. On the other hand, exogenous RA could cause cleft palate in offspring when it is given to pregnant animals at either the early or late phases of palatogenesis, but the pathogenetic mechanism of cleft palate caused by excess RA remains not fully elucidated. The aim of the present study was to investigate the effects of excess of RA on early palatogenesis in mouse fetuses and analyze the teratogenic mechanism, especially at the stage prior to palatal shelf elevation. We gave all-trans RA (100 mg/kg) orally to E11.5 ICR pregnant mice and observed the changes occurring in the palatal shelves of their fetuses. It was found that apoptotic cell death increased not only in the epithelium of the palatal shelves but also in the tongue primordium, which might affect tongue withdrawal movement during palatogenesis and impair the horizontal elevation of palatal shelves. In addition, RA was found to prevent the G 1 /S progression of palatal mesenchymal cells through upregulation of p21 Cip1 , leading to Rb hypophospholylation. Thus, RA appears to cause G 1 arrest in palatal mesenchymal cells in a similar manner as in various cancer and embryonic cells. It is likely that apoptotic cell death and cell cycle disruption are involved in cleft palate formation induced by RA

  16. Inactivation of EGFR/AKT signaling enhances TSA-induced ovarian cancer cell differentiation.

    Science.gov (United States)

    Shao, Genbao; Lai, Wensheng; Wan, Xiaolei; Xue, Jing; Wei, Ye; Jin, Jie; Zhang, Liuping; Lin, Qiong; Shao, Qixiang; Zou, Shengqiang

    2017-05-01

    Ovarian tumor is one of the most lethal gynecologic cancers, but differentiation therapy for this cancer is poorly characterized. Here, we show that thrichostatin A (TSA), the well known inhibitor of histone deacetylases (HDACs), can induce cell differentiation in HO8910 ovarian cancer cells. TSA-induced cell differentiation is characterized by typical morphological change, increased expression of the differentiation marker FOXA2, decreased expression of the pluripotency markers SOX2 and OCT4, suppressing cell proliferation, and cell cycle arrest in the G1 phase. TSA also induces an elevated expression of cell cycle inhibitory protein p21Cip1 along with a decrease in cell cycle regulatory protein cyclin D1. Significantly, blockage of epidermal growth factor receptor (EGFR) signaling pathway with specific inhibitors of this signaling cascade promotes the TSA-induced differentiation of HO8910 cells. These results imply that the EGFR cascade inhibitors in combination with TSA may represent a promising differentiation therapy strategy for ovarian cancer.

  17. Caffeine and human DNA metabolism: the magic and the mystery

    International Nuclear Information System (INIS)

    Kaufmann, William K.; Heffernan, Timothy P.; Beaulieu, Lea M.; Doherty, Sharon; Frank, Alexandra R.; Zhou Yingchun; Bryant, Miriam F.; Zhou Tong; Luche, Douglas D.; Nikolaishvili-Feinberg, Nana; Simpson, Dennis A.; Cordeiro-Stone, Marila

    2003-01-01

    The ability of caffeine to reverse cell cycle checkpoint function and enhance genotoxicity after DNA damage was examined in telomerase-expressing human fibroblasts. Caffeine reversed the ATM-dependent S and G2 checkpoint responses to DNA damage induced by ionizing radiation (IR), as well as the ATR- and Chk1-dependent S checkpoint response to ultraviolet radiation (UVC). Remarkably, under conditions in which IR-induced G2 delay was reversed by caffeine, IR-induced G1 arrest was not. Incubation in caffeine did not increase the percentage of cells entering the S phase 6-8 h after irradiation; ATM-dependent phosphorylation of p53 and transactivation of p21 Cip1/Waf1 post-IR were resistant to caffeine. Caffeine alone induced a concentration- and time-dependent inhibition of DNA synthesis. It inhibited the entry of human fibroblasts into S phase by 70-80% regardless of the presence or absence of wildtype ATM or p53. Caffeine also enhanced the inhibition of cell proliferation induced by UVC in XP variant fibroblasts. This effect was reversed by expression of DNA polymerase η, indicating that translesion synthesis of UVC-induced pyrimidine dimers by DNA pol η protects human fibroblasts against UVC genotoxic effects even when other DNA repair functions are compromised by caffeine

  18. Inactivation of the FoxO3a transcription factor is associated with the production of reactive oxygen species during protein kinase CK2 downregulation-mediated senescence in human colon cancer and breast cancer cells.

    Science.gov (United States)

    Park, Seong-Yeol; Bae, Young-Seuk

    2016-09-09

    We previously showed that protein kinase CK2 downregulation mediates senescence through the reactive oxygen species (ROS)-p53-p21(Cip1/WAF1) pathway in various human cells. In the present study, we investigated whether the FoxO3a transcription factor is associated with ROS production during CK2 downregulation-induced senescence in human colon cancer HCT116 and breast cancer MCF-7 cells. FoxO3a overexpression suppressed ROS production and p53 stabilization induced by a CK2α knockdown. CK2α downregulation induced nuclear export of FoxO3a through stimulation of AKT-mediated phosphorylation of FoxO3a and decreased transcription of its target genes (Cu/ZnSOD, MnSOD, and catalase). In contrast, CK2α overexpression inhibited AKT-mediated FoxO3a phosphorylation. This resulted in nuclear accumulation of FoxO3a, and elevated expression of its target genes. Therefore, these data indicate for the first time that CK2 downregulation stimulates ROS generation by inhibiting FoxO3a during premature senescence in human colon and breast cancer cells. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Restrictions in cell cycle progression of adult vestibular supporting cells in response to ectopic cyclin D1 expression.

    Directory of Open Access Journals (Sweden)

    Heidi Loponen

    Full Text Available Sensory hair cells and supporting cells of the mammalian inner ear are quiescent cells, which do not regenerate. In contrast, non-mammalian supporting cells have the ability to re-enter the cell cycle and produce replacement hair cells. Earlier studies have demonstrated cyclin D1 expression in the developing mouse supporting cells and its downregulation along maturation. In explant cultures of the mouse utricle, we have here focused on the cell cycle control mechanisms and proliferative potential of adult supporting cells. These cells were forced into the cell cycle through adenoviral-mediated cyclin D1 overexpression. Ectopic cyclin D1 triggered robust cell cycle re-entry of supporting cells, accompanied by changes in p27(Kip1 and p21(Cip1 expressions. Main part of cell cycle reactivated supporting cells were DNA damaged and arrested at the G2/M boundary. Only small numbers of mitotic supporting cells and rare cells with signs of two successive replications were found. Ectopic cyclin D1-triggered cell cycle reactivation did not lead to hyperplasia of the sensory epithelium. In addition, a part of ectopic cyclin D1 was sequestered in the cytoplasm, reflecting its ineffective nuclear import. Combined, our data reveal intrinsic barriers that limit proliferative capacity of utricular supporting cells.

  20. Restrictions in cell cycle progression of adult vestibular supporting cells in response to ectopic cyclin D1 expression.

    Science.gov (United States)

    Loponen, Heidi; Ylikoski, Jukka; Albrecht, Jeffrey H; Pirvola, Ulla

    2011-01-01

    Sensory hair cells and supporting cells of the mammalian inner ear are quiescent cells, which do not regenerate. In contrast, non-mammalian supporting cells have the ability to re-enter the cell cycle and produce replacement hair cells. Earlier studies have demonstrated cyclin D1 expression in the developing mouse supporting cells and its downregulation along maturation. In explant cultures of the mouse utricle, we have here focused on the cell cycle control mechanisms and proliferative potential of adult supporting cells. These cells were forced into the cell cycle through adenoviral-mediated cyclin D1 overexpression. Ectopic cyclin D1 triggered robust cell cycle re-entry of supporting cells, accompanied by changes in p27(Kip1) and p21(Cip1) expressions. Main part of cell cycle reactivated supporting cells were DNA damaged and arrested at the G2/M boundary. Only small numbers of mitotic supporting cells and rare cells with signs of two successive replications were found. Ectopic cyclin D1-triggered cell cycle reactivation did not lead to hyperplasia of the sensory epithelium. In addition, a part of ectopic cyclin D1 was sequestered in the cytoplasm, reflecting its ineffective nuclear import. Combined, our data reveal intrinsic barriers that limit proliferative capacity of utricular supporting cells.

  1. DNA-damage-induced differentiation of leukaemic cells as an anti-cancer barrier.

    Science.gov (United States)

    Santos, Margarida A; Faryabi, Robert B; Ergen, Aysegul V; Day, Amanda M; Malhowski, Amy; Canela, Andres; Onozawa, Masahiro; Lee, Ji-Eun; Callen, Elsa; Gutierrez-Martinez, Paula; Chen, Hua-Tang; Wong, Nancy; Finkel, Nadia; Deshpande, Aniruddha; Sharrow, Susan; Rossi, Derrick J; Ito, Keisuke; Ge, Kai; Aplan, Peter D; Armstrong, Scott A; Nussenzweig, André

    2014-10-02

    Self-renewal is the hallmark feature both of normal stem cells and cancer stem cells. Since the regenerative capacity of normal haematopoietic stem cells is limited by the accumulation of reactive oxygen species and DNA double-strand breaks, we speculated that DNA damage might also constrain leukaemic self-renewal and malignant haematopoiesis. Here we show that the histone methyl-transferase MLL4, a suppressor of B-cell lymphoma, is required for stem-cell activity and an aggressive form of acute myeloid leukaemia harbouring the MLL-AF9 oncogene. Deletion of MLL4 enhances myelopoiesis and myeloid differentiation of leukaemic blasts, which protects mice from death related to acute myeloid leukaemia. MLL4 exerts its function by regulating transcriptional programs associated with the antioxidant response. Addition of reactive oxygen species scavengers or ectopic expression of FOXO3 protects MLL4(-/-) MLL-AF9 cells from DNA damage and inhibits myeloid maturation. Similar to MLL4 deficiency, loss of ATM or BRCA1 sensitizes transformed cells to differentiation, suggesting that myeloid differentiation is promoted by loss of genome integrity. Indeed, we show that restriction-enzyme-induced double-strand breaks are sufficient to induce differentiation of MLL-AF9 blasts, which requires cyclin-dependent kinase inhibitor p21(Cip1) (Cdkn1a) activity. In summary, we have uncovered an unexpected tumour-promoting role of genome guardians in enforcing the oncogene-induced differentiation blockade in acute myeloid leukaemia.

  2. Sulforaphane induces cell cycle arrest and apoptosis in acute lymphoblastic leukemia cells.

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    Koramit Suppipat

    Full Text Available Acute lymphoblastic leukemia (ALL is the most common hematological cancer in children. Although risk-adaptive therapy, CNS-directed chemotherapy, and supportive care have improved the survival of ALL patients, disease relapse is still the leading cause of cancer-related death in children. Therefore, new drugs are needed as frontline treatments in high-risk disease and as salvage agents in relapsed ALL. In this study, we report that purified sulforaphane, a natural isothiocyanate found in cruciferous vegetables, has anti-leukemic properties in a broad range of ALL cell lines and primary lymphoblasts from pediatric T-ALL and pre-B ALL patients. The treatment of ALL leukemic cells with sulforaphane resulted in dose-dependent apoptosis and G2/M cell cycle arrest, which was associated with the activation of caspases (3, 8, and 9, inactivation of PARP, p53-independent upregulation of p21(CIP1/WAF1, and inhibition of the Cdc2/Cyclin B1 complex. Interestingly, sulforaphane also inhibited the AKT and mTOR survival pathways in most of the tested cell lines by lowering the levels of both total and phosphorylated proteins. Finally, the administration of sulforaphane to the ALL xenograft models resulted in a reduction of tumor burden, particularly following oral administration, suggesting a potential role as an adjunctive agent to improve the therapeutic response in high-risk ALL patients with activated AKT signaling.

  3. p18(Hamlet) mediates different p53-dependent responses to DNA-damage inducing agents.

    Science.gov (United States)

    Lafarga, Vanesa; Cuadrado, Ana; Nebreda, Angel R

    2007-10-01

    Cells organize appropriate responses to environmental cues by activating specific signaling networks. Two proteins that play key roles in coordinating stress responses are the kinase p38alpha (MAPK14) and the transcription factor p53 (TP53). Depending on the nature and the extent of the stress-induced damage, cells may respond by arresting the cell cycle or by undergoing cell death, and these responses are usually associated with the phosphorylation of particular substrates by p38alpha as well as the activation of specific target genes by p53. We recently characterized a new p38alpha substrate, named p18(Hamlet) (ZNHIT1), which mediates p53-dependent responses to different genotoxic stresses. Thus, cisplatin or UV light induce stabilization of the p18(Hamlet) protein, which then enhances the ability of p53 to bind to and activate the promoters of pro-apoptotic genes such as NOXA and PUMA leading to apoptosis induction. In a similar way, we report here that p18(Hamlet) can also mediate the cell cycle arrest induced in response to gamma-irradiation, by participating in the p53-dependent upregulation of the cell cycle inhibitor p21(Cip1) (CDKN1A).

  4. A Splice Variant of HER2 Corresponding to Herstatin Is Expressed in the Noncancerous Breast and in Breast Carcinomas

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    Triantafyllia Koletsa

    2008-07-01

    Full Text Available Herstatin (HST is an alternatively spliced HER2 product with growth-inhibitory properties in experimental cancer systems. The role of HST in adult human tissues and disease remains unexplored. Here, we investigated HST expression at the mRNA and protein (immunohistochemistry [IHC] level in parallel with parameters reflecting HER activation in 187 breast carcinomas and matched noncancerous breast tissues (NCBT. Noncancerous breast tissues demonstrated the highest HST/HER2 transcript ratios corresponding to a few positive epithelial and stromal cells by IHC. Although HST/HER2 transcript ratios in tumors were inversely associated with HER2 IHC grading (P = .0048 for HER2 IHC-1+ and P = .0006 for HER2 IHC-2+ vs HER2-negative tumors, relative HST expression within the same tumor/NCBT system remained constant. HST/HER2 ratios did not predict the presence of HST protein, which was found in 46 (25% of 187 tumors. A subgroup of HER2 IHC-3+ tumors exhibited high HST/HER2 transcript ratios, strong HST protein positivity, and cytoplasmic phospho-Akt/PKB and p21CIP1/WAF1 localization. In conclusion, HST may act as a paracrine factor in the adult breast. Because HST is described as an endogenous pan-HER inhibitor, the presence of this protein in breast carcinomas may portent the inefficiency of exogenous efforts to block HER2 dimerization, whereas its absence may justify such interventions.

  5. Omega-3 Polyunsaturated Fatty Acids Enhance Neuronal Differentiation in Cultured Rat Neural Stem Cells

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    Masanori Katakura

    2013-01-01

    Full Text Available Polyunsaturated fatty acids (PUFAs can induce neurogenesis and recovery from brain diseases. However, the exact mechanisms of the beneficial effects of PUFAs have not been conclusively described. We recently reported that docosahexaenoic acid (DHA induced neuronal differentiation by decreasing Hes1 expression and increasing p27kip1 expression, which causes cell cycle arrest in neural stem cells (NSCs. In the present study, we examined the effect of eicosapentaenoic acid (EPA and arachidonic acid (AA on differentiation, expression of basic helix-loop-helix transcription factors (Hes1, Hes6, and NeuroD, and the cell cycle of cultured NSCs. EPA also increased mRNA levels of Hes1, an inhibitor of neuronal differentiation, Hes6, an inhibitor of Hes1, NeuroD, and Map2 mRNA and Tuj-1-positive cells (a neuronal marker, indicating that EPA induced neuronal differentiation. EPA increased the mRNA levels of p21cip1 and p27kip1, a cyclin-dependent kinase inhibitor, which indicated that EPA induced cell cycle arrest. Treatment with AA decreased Hes1 mRNA but did not affect NeuroD and Map2 mRNA levels. Furthermore, AA did not affect the number of Tuj-1-positive cells or cell cycle progression. These results indicated that EPA could be involved in neuronal differentiation by mechanisms alternative to those of DHA, whereas AA did not affect neuronal differentiation in NSCs.

  6. Alteration of gene expression profiles in skeletal muscle of rats exposed to microgravity during a spaceflight

    Science.gov (United States)

    Taylor, Wayne E.; Bhasin, Shalender; Lalani, Rukhsana; Datta, Anuj; Gonzalez-Cadavid, Nestor F.

    2002-01-01

    To clarify the mechanism of skeletal muscle wasting during spaceflights, we investigated whether intramuscular gene expression profiles are affected, by using DNA microarray methods. Male rats sent on the 17-day NASA STS-90 Neurolab spaceflight were sacrificed 24 hours after return to earth (MG group). Ground control rats were maintained for 17 days in flight-simulated cages (CS group). Spaceflight induced a 19% and 23% loss of tibialis anterior and gastrocnemius muscle mass, respectively, as compared to ground controls. Muscle RNA was analyzed by the Clontech Atlas DNA expression array in four rats, with two MG/ CS pairs for the tibialis anterior, and one pair for the gastrocnemius. Alterations in gene expression were verified for selected genes by reverse-transcription PCR. In both muscles of MG rats, mRNAs for 12 genes were up-regulated by over 2-fold, and 38 were down-regulated compared to controls. There was inhibition of genes for cell proliferation and growth factor cascades, including cell cycle genes and signal transduction proteins, such as p21 Cip1, retinoblastoma (Rb), cyclins G1/S, -E and -D3, MAP kinase 3, MAD3, and ras related protein RAB2. These data indicate that following exposure to microgravity, there is downregulation of genes involved in regulation of muscle satellite cell replication.

  7. PPARγ activation abolishes LDL-induced proliferation of human aortic smooth muscle cells via SOD-mediated down-regulation of superoxide

    International Nuclear Information System (INIS)

    Heo, Kyung-Sun; Kim, Dong-Uk; Ryoo, Sungwoo; Nam, Miyoung; Baek, Seung Tae; Kim, Lila; Park, Song-Kyu; Myung, Chang-Seon; Hoe, Kwang-Lae

    2007-01-01

    Native LDL would be a mitogenic and chemotactic stimulus of VSMC proliferation and differentiation in the atherosclerotic lesion where endothelial disruption occurred. In previous studies, our group investigated the molecular mechanisms by which LDL induces IL-8 production and by which PPARα activation abolishes LDL effects in human aortic SMCs (hAoSMCs). Herein is the first report of PPARγ activation by troglitazone (TG) exerting its inhibitory effects on LDL-induced cell proliferation via generation not of H 2 O 2 , but of O2?-, and the subsequent activation of Erk1/2 in hAoSMCs. Moreover, in this study TG abolished the LDL-accelerated G 1 -S progression to control levels via down-regulation of active cyclinD1/CDK4 and cyclinE/CDK2 complexes and up-regulation of p21 Cip1 expression. TG exerted its anti-proliferative effects through the up-regulation of basal superoxide dismutase (SOD) expression. This data suggests that the regulation of O2?- is located at the crossroads between LDL signaling and cell proliferation

  8. A methoxyflavanone derivative from the Asian medicinal herb (Perilla frutescens) induces p53-mediated G2/M cell cycle arrest and apoptosis in A549 human lung adenocarcinoma.

    Science.gov (United States)

    Abd El-Hafeez, Amer Ali; Fujimura, Takashi; Kamei, Rikiya; Hirakawa, Noriko; Baba, Kenji; Ono, Kazuhisa; Kawamoto, Seiji

    2017-07-14

    Perilla frutescens is an Asian dietary herb consumed as an essential seasoning in Japanese cuisine as well as used for a Chinese medicine. Here, we report that a newly found methoxyflavanone derivative from P. frutescens (Perilla-derived methoxyflavanone, PDMF; 8-hydroxy-5,7-dimethoxyflavanone) shows carcinostatic activity on human lung adenocarcinoma, A549. We found that treatment with PDMF significantly inhibited cell proliferation and decreased viability through induction of G 2 /M cell cycle arrest and apoptosis. The PDMF stimulation induces phosphorylation of tumor suppressor p53 on Ser15, and increases its protein amount in conjunction with up-regulation of downstream cyclin-dependent kinase inhibitor p21 Cip1/Waf1 and proapoptotic caspases, caspase-9 and caspase-3. We also found that small interfering RNA knockdown of p53 completely abolished the PDMF-induced G 2 /M cell cycle arrest, and substantially abrogated its proapoptotic potency. These results suggest that PDMF represents a useful tumor-preventive phytochemical that triggers p53-driven G 2 /M cell cycle arrest and apoptosis.

  9. Inhibition of DEPDC1A, a bad prognostic marker in multiple myeloma, delays growth and induces mature plasma cell markers in malignant plasma cells.

    Directory of Open Access Journals (Sweden)

    Alboukadel Kassambara

    Full Text Available High throughput DNA microarray has made it possible to outline genes whose expression in malignant plasma cells is associated with short overall survival of patients with Multiple Myeloma (MM. A further step is to elucidate the mechanisms encoded by these genes yielding to drug resistance and/or patients' short survival. We focus here on the biological role of the DEP (for Disheveled, EGL-10, Pleckstrin domain contained protein 1A (DEPDC1A, a poorly known protein encoded by DEPDC1A gene, whose high expression in malignant plasma cells is associated with short survival of patients. Using conditional lentiviral vector delivery of DEPDC1A shRNA, we report that DEPDC1A knockdown delayed the growth of human myeloma cell lines (HMCLs, with a block in G2 phase of the cell cycle, p53 phosphorylation and stabilization, and p21(Cip1 accumulation. DEPDC1A knockdown also resulted in increased expression of mature plasma cell markers, including CXCR4, IL6-R and CD38. Thus DEPDC1A could contribute to the plasmablast features of MMCs found in some patients with adverse prognosis, blocking the differentiation of malignant plasma cells and promoting cell cycle.

  10. Antihelminthic benzimidazoles are novel HIF activators that prevent oxidative neuronal death via binding to tubulin.

    Science.gov (United States)

    Aleyasin, Hossein; Karuppagounder, Saravanan S; Kumar, Amit; Sleiman, Sama; Basso, Manuela; Ma, Thong; Siddiq, Ambreena; Chinta, Shankar J; Brochier, Camille; Langley, Brett; Haskew-Layton, Renee; Bane, Susan L; Riggins, Gregory J; Gazaryan, Irina; Starkov, Anatoly A; Andersen, Julie K; Ratan, Rajiv R

    2015-01-10

    Pharmacological activation of the adaptive response to hypoxia is a therapeutic strategy of growing interest for neurological conditions, including stroke, Huntington's disease, and Parkinson's disease. We screened a drug library with known safety in humans using a hippocampal neuroblast line expressing a reporter of hypoxia-inducible factor (HIF)-dependent transcription. Our screen identified more than 40 compounds with the ability to induce hypoxia response element-driven luciferase activity as well or better than deferoxamine, a canonical activator of hypoxic adaptation. Among the chemical entities identified, the antihelminthic benzimidazoles represented one pharmacophore that appeared multiple times in our screen. Secondary assays confirmed that antihelminthics stabilized the transcriptional activator HIF-1α and induced expression of a known HIF target gene, p21(cip1/waf1), in post-mitotic cortical neurons. The on-target effect of these agents in stimulating hypoxic signaling was binding to free tubulin. Moreover, antihelminthic benzimidazoles also abrogated oxidative stress-induced death in vitro, and this on-target effect also involves binding to free tubulin. These studies demonstrate that tubulin-binding drugs can activate a component of the hypoxic adaptive response, specifically the stabilization of HIF-1α and its downstream targets. Tubulin-binding drugs, including antihelminthic benzimidazoles, also abrogate oxidative neuronal death in primary neurons. Given their safety in humans and known ability to penetrate into the central nervous system, antihelminthic benzimidazoles may be considered viable candidates for treating diseases associated with oxidative neuronal death, including stroke.

  11. The RNA-binding protein Celf1 post-transcriptionally regulates p27Kip1 and Dnase2b to control fiber cell nuclear degradation in lens development.

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    Archana D Siddam

    2018-03-01

    Full Text Available Opacification of the ocular lens, termed cataract, is a common cause of blindness. To become transparent, lens fiber cells undergo degradation of their organelles, including their nuclei, presenting a fundamental question: does signaling/transcription sufficiently explain differentiation of cells progressing toward compromised transcriptional potential? We report that a conserved RNA-binding protein Celf1 post-transcriptionally controls key genes to regulate lens fiber cell differentiation. Celf1-targeted knockout mice and celf1-knockdown zebrafish and Xenopus morphants have severe eye defects/cataract. Celf1 spatiotemporally down-regulates the cyclin-dependent kinase (Cdk inhibitor p27Kip1 by interacting with its 5' UTR and mediating translation inhibition. Celf1 deficiency causes ectopic up-regulation of p21Cip1. Further, Celf1 directly binds to the mRNA of the nuclease Dnase2b to maintain its high levels. Together these events are necessary for Cdk1-mediated lamin A/C phosphorylation to initiate nuclear envelope breakdown and DNA degradation in fiber cells. Moreover, Celf1 controls alternative splicing of the membrane-organization factor beta-spectrin and regulates F-actin-crosslinking factor Actn2 mRNA levels, thereby controlling fiber cell morphology. Thus, we illustrate new Celf1-regulated molecular mechanisms in lens development, suggesting that post-transcriptional regulatory RNA-binding proteins have evolved conserved functions to control vertebrate oculogenesis.

  12. DNA-dependent protein kinase catalytic subunit functions in metastasis and influences survival in advanced-stage laryngeal squamous cell carcinoma.

    Science.gov (United States)

    He, Sha-Sha; Chen, Yong; Shen, Xiao-Ming; Wang, Hong-Zhi; Sun, Peng; Dong, Jun; Guo, Gui-Fang; Chen, Ju-Gao; Xia, Liang-Ping; Hu, Pei-Li; Qiu, Hui-Juan; Liu, Shou-Sheng; Zhou, Yi-Xin; Wang, Wei; Hu, Wei-Han; Cai, Xiu-Yu

    2017-01-01

    Background: DNA-dependent protein kinase catalytic subunit (DNA-PKcs) is known to function in several types of cancer. In this study, we investigated the expression and clinicopathologic significance of DNA-PKcs in laryngeal squamous cell carcinoma (LSCC). Methods: We conducted a retrospective study of 208 patients with advanced-stage LSCC treated at Sun Yat-sen University Cancer Center, Guangzhou, China. We assessed DNA-PKcs and p16INK4a (p16) status using immunohistochemistry. We examined the association between DNA-PKcs expression and clinicopathologic features and survival outcomes. To evaluate the independent prognostic relevance of DNA-PKcs, we used univariate and multivariate Cox regression models. We estimated overall survival (OS) and distant metastasis-free survival (DMFS) using the Kaplan-Meier method. Results: Immunohistochemical analyses revealed that 163/208 (78.4%) of the LSCC tissue samples exhibited high DNA-PKcs expression. High DNA-PKcs expression was significantly associated with survival outcomes ( P = 0.016) and distant metastasis ( P = 0.02; chi-squared test). High DNA-PKcs expression was associated with a significantly shorter OS and DMFS than low DNA-PKcs expression ( P = 0.029 and 0.033, respectively; log-rank test), and was associated with poor OS in the p16-positive subgroup ( P = 0.047). Multivariate analysis identified DNA-PKcs as an independent prognostic indicator of OS and DMFS in all patients ( P = 0.039 and 0.037, respectively). Conclusions : Our results suggest that patients with LSCC in whom DNA-PKcs expression is elevated have a higher incidence of distant metastasis and a poorer prognosis. DNA-PKcs may represent a marker of tumor progression in patients with p16-positive LSCC.

  13. Epigenetics modifications and therapeutic prospects in human thyroid cancer

    Directory of Open Access Journals (Sweden)

    Maria Graziella eCatalano

    2012-03-01

    Full Text Available At present no successful treatment is available for advanced thyroid cancer, which comprises poorly differentiated, anaplastic, and metastatic or recurrent differentiated thyroid cancer not responding to radioiodine. In the last few years, biologically targeted therapies for advanced thyroid carcinomas have been proposed on the basis of the recognition of key oncogenic mutations. Although the results of several phase II trials look promising, none of the patients treated had a complete response, and only a minority of them had a partial response, suggesting that the treatment is, at best, effective in stabilizing patients with progressive disease. Epigenetic refers to the study of heritable changes in gene expression that occur without any alteration in the primary DNA sequence. The epigenetic processes establish and maintain the global and local chroma¬tin states that determine gene expression. Epigenetic abnormalities are present in almost all cancers and, together with genetic changes, drive tumour progression. Various genes involved in the control of cell proliferation and invasion (p16INK4A, RASSF1A,PTEN, Rap1GAP, TIMP3, DAPK, RARβ2, E-cadherin, and CITED1 as well as genes specific of thyroid differentiation (Na+/I- symport, TSH receptor, pendrin, SL5A8, and TTF-1 present aberrant methylation in thyroid cancer.This review deals with the most frequent epigenetic alterations in thyroid cancer and focuses on epigenetic therapy, whose goal is to target the chromatin in rapidly dividing tumour cells and potentially restore normal cell functions. Experimental data and clinical trials, especially using deacetylase inhibitors and demethylating agents, are discussed.

  14. Antitumor effects of vitamins K1, K2 and K3 on hepatocellular carcinoma in vitro and in vivo.

    Science.gov (United States)

    Hitomi, Misuzu; Yokoyama, Fumi; Kita, Yuko; Nonomura, Takako; Masaki, Tsutomu; Yoshiji, Hitoshi; Inoue, Hideyuki; Kinekawa, Fumihiko; Kurokohchi, Kazutaka; Uchida, Naohito; Watanabe, Seishiro; Kuriyama, Shigeki

    2005-03-01

    A number of studies have shown that various K vitamins, specifically vitamins K2 and K3, possess antitumor activity on various types of rodent- and human-derived neoplastic cell lines. In the present study, we examined the antitumor effects of vitamins K1, K2 and K3 on PLC/PRF/5 human hepatocellular carcinoma (HCC) cells in vitro and in vivo. Furthermore, we examined the mechanisms of antitumor actions of these vitamins in vitro and in vivo. Although vitamin K1 did not inhibit proliferation of PLC/PRF/5 cells at a 90-microM concentration (the highest tested), vitamins K2 and K3 suppressed proliferation of the cells at concentrations of 90 and 9 microM, respectively. By flow cytometric analysis, it was shown that not only vitamin K1, but also vitamin K2 did not induce apoptosis or cell cycle arrest on PLC/PRF/5 cells. In contrast, vitamin K3 induced G1 arrest, but not apoptosis on PLC/PRF/5 cells. Subsequent in vivo study using subcutaneous HCC-bearing athymic nude mice demonstrated that both vitamins K2 and K3 markedly suppressed the growth of HCC tumors to similar extent. Protein expression of cyclin D1 and cyclin-dependent kinase 4 (Cdk4), but not p16INK4a Cdk inhibitor in the tumor was significantly reduced by vitamin K2 or K3 treatment, indicating that vitamins K2 and K3 may induce G1 arrest of cell cycle on PLC/PRF/5 cells in vivo. Taken collectively, vitamins K2 and K3 were able to induce potent antitumor effects on HCC in vitro and in vivo, at least in part, by inducing G1 arrest of the cell cycle. The results indicate that vitamins K2 and K3 may be useful agents for the treatment of patients with HCC.

  15. The novel Hsp90 inhibitor NXD30001 induces tumor regression in a genetically engineered mouse model of glioblastoma multiforme.

    Science.gov (United States)

    Zhu, Haihao; Woolfenden, Steve; Bronson, Roderick T; Jaffer, Zahara M; Barluenga, Sofia; Winssinger, Nicolas; Rubenstein, Allan E; Chen, Ruihong; Charest, Al

    2010-09-01

    Glioblastoma multiforme (GBM) has an abysmal prognosis. We now know that the epidermal growth factor receptor (EGFR) signaling pathway and the loss of function of the tumor suppressor genes p16Ink4a/p19ARF and PTEN play a crucial role in GBM pathogenesis: initiating the early stages of tumor development, sustaining tumor growth, promoting infiltration, and mediating resistance to therapy. We have recently shown that this genetic combination is sufficient to promote the development of GBM in adult mice. Therapeutic agents raised against single targets of the EGFR signaling pathway have proven rather inefficient in GBM therapy, showing the need for combinatorial therapeutic approaches. An effective strategy for concurrent disruption of multiple signaling pathways is via the inhibition of the molecular chaperone heat shock protein 90 (Hsp90). Hsp90 inhibition leads to the degradation of so-called client proteins, many of which are key effectors of GBM pathogenesis. NXD30001 is a novel second generation Hsp90 inhibitor that shows improved pharmacokinetic parameters. Here we show that NXD30001 is a potent inhibitor of GBM cell growth in vitro consistent with its capacity to inhibit several key targets and regulators of GBM biology. We also show the efficacy of NXD30001 in vivo in an EGFR-driven genetically engineered mouse model of GBM. Our findings establish that the Hsp90 inhibitor NXD30001 is a therapeutically multivalent molecule, whose actions strike GBM at the core of its drivers of tumorigenesis and represent a compelling rationale for its use in GBM treatment.

  16. Methylation of Breast Cancer Predisposition Genes in Early-Onset Breast Cancer: Australian Breast Cancer Family Registry.

    Directory of Open Access Journals (Sweden)

    Cameron M Scott

    Full Text Available DNA methylation can mimic the effects of both germline and somatic mutations for cancer predisposition genes such as BRCA1 and p16INK4a. Constitutional DNA methylation of the BRCA1 promoter has been well described and is associated with an increased risk of early-onset breast cancers that have BRCA1-mutation associated histological features. The role of methylation in the context of other breast cancer predisposition genes has been less well studied and often with conflicting or ambiguous outcomes. We examined the role of methylation in known breast cancer susceptibility genes in breast cancer predisposition and tumor development. We applied the Infinium HumanMethylation450 Beadchip (HM450K array to blood and tumor-derived DNA from 43 women diagnosed with breast cancer before the age of 40 years and measured the methylation profiles across promoter regions of BRCA1, BRCA2, ATM, PALB2, CDH1, TP53, FANCM, CHEK2, MLH1, MSH2, MSH6 and PMS2. Prior genetic testing had demonstrated that these women did not carry a germline mutation in BRCA1, ATM, CHEK2, PALB2, TP53, BRCA2, CDH1 or FANCM. In addition to the BRCA1 promoter region, this work identified regions with variable methylation at multiple breast cancer susceptibility genes including PALB2 and MLH1. Methylation at the region of MLH1 in these breast cancers was not associated with microsatellite instability. This work informs future studies of the role of methylation in breast cancer susceptibility gene silencing.

  17. Human papillomavirus and p53 expression in cancer of unknown primary in the head and neck region in relation to clinical outcome

    International Nuclear Information System (INIS)

    Sivars, Lars; Näsman, Anders; Tertipis, Nikolaos; Vlastos, Andrea; Ramqvist, Torbjörn; Dalianis, Tina; Munck-Wikland, Eva; Nordemar, Sushma

    2014-01-01

    Patients with cancer of unknown primary (CUP) in the head neck region are generally treated with neck dissection followed by radiotherapy at times combined with chemotherapy, a treatment associated with considerable side effects. Some of these tumors may originate as human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma (OSCC), with better clinical outcome than head neck squamous cell cancer (HNSCC) in general, and could potentially do well with less treatment. Here, we therefore investigated whether HPV status and p53-expression correlated to clinical outcome in patients with CUP in the head neck region. Fifty metastases were analyzed for presence of HPV DNA, and expression of p16 INK4A and p53 and the data were correlated to clinical outcome. Patients with HPV DNA-positive (HPV DNA+ ) metastases had significantly better 5-year overall survival (OS) compared to those with HPV DNA− metastases (80.0% vs. 36.7%, respectively; P = 0.004), with a similar tendency for disease-free survival (DFS). These survival rates showed excellent concordance with those of HPV DNA+ and HPV DNA− OSCC in Sweden during the same time period, strengthening the hypothesis that HPV DNA+ head and neck CUP may originate from HPV DNA+ OSCC. In addition, having absent/intermediary-low as compared to high expression of p53 correlated to a better prognosis with a 69% as compared to 14% 5-year OS, respectively (P < 0.001), and for DFS the tendency was analogous. In conclusion, both HPV status and p53 expression are valuable prognostic factors in patients with CUP in the head and neck region and should be further explored for clinical use

  18. Uncovering the cellular and molecular changes in tendon stem/progenitor cells attributed to tendon aging and degeneration.

    Science.gov (United States)

    Kohler, Julia; Popov, Cvetan; Klotz, Barbara; Alberton, Paolo; Prall, Wolf Christian; Haasters, Florian; Müller-Deubert, Sigrid; Ebert, Regina; Klein-Hitpass, Ludger; Jakob, Franz; Schieker, Matthias; Docheva, Denitsa

    2013-12-01

    Although the link between altered stem cell properties and tissue aging has been recognized, the molecular and cellular processes of tendon aging have not been elucidated. As tendons contain stem/progenitor cells (TSPC), we investigated whether the molecular and cellular attributes of TSPC alter during tendon aging and degeneration. Comparing TSPC derived from young/healthy (Y-TSPC) and aged/degenerated human Achilles tendon biopsies (A-TSPC), we observed that A-TSPC exhibit a profound self-renewal and clonogenic deficits, while their multipotency was still retained. Senescence analysis showed a premature entry into senescence of the A-TSPC, a finding accompanied by an upregulation of p16(INK4A). To identify age-related molecular factors, we performed microarray and gene ontology analyses. These analyses revealed an intriguing transcriptomal shift in A-TSPC, where the most differentially expressed probesets encode for genes regulating cell adhesion, migration, and actin cytoskeleton. Time-lapse analysis showed that A-TSPC exhibit decelerated motion and delayed wound closure concomitant to a higher actin stress fiber content and a slower turnover of actin filaments. Lastly, based on the expression analyses of microarray candidates, we suggest that dysregulated cell-matrix interactions and the ROCK kinase pathway might be key players in TSPC aging. Taken together, we propose that during tendon aging and degeneration, the TSPC pool is becoming exhausted in terms of size and functional fitness. Thus, our study provides the first fundamental basis for further exploration into the molecular mechanisms behind tendon aging and degeneration as well as for the selection of novel tendon-specific therapeutical targets. © 2013 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

  19. Loss of aryl hydrocarbon receptor promotes gene changes associated with premature hematopoietic stem cell exhaustion and development of a myeloproliferative disorder in aging mice.

    Science.gov (United States)

    Singh, Kameshwar P; Bennett, John A; Casado, Fanny L; Walrath, Jason L; Welle, Stephen L; Gasiewicz, Thomas A

    2014-01-15

    Loss of immune function and increased hematopoietic disease are among the most clinically significant consequences of aging. Hematopoietic stem cells (HSCs) from mice lacking aryl hydrocarbon receptor (AhR) have high rates of cell division. Studies were designed to test the hypothesis that aging AhR-null allele (AhR-KO) mice develop premature HSC exhaustion, and changes leading to hematological disease. Compared to wild-type, aging AhR-KO mice showed a decreased survival rate, splenomegaly, increased circulating white blood cells, hematopoietic cell accumulation in tissues, and anemia. Analysis of bone marrow indicated increased numbers of stem/progenitor and lineage-committed cells, but decreased erythroid progenitors. There was also decreased self-renewal capacity of HSCs determined by competitive repopulation and serial transplantation. HSCs also showed increased levels of reactive oxygen species (ROS), Ki-67, and γ-H2A.X, but decreased p16(Ink4a). Splenic cells from aging KO mice had abnormal expression of genes, including Gata-1, Sh2d3c, Gfi-1, p21, and c-myc, involved in trafficking and associated with leukemia. HSCs from AhR-KO mice had gene changes related to HSC maintenance and consistent with phenotype observed. The most prominent gene changes (overexpression of Srpk2, Creb1, Hes1, mtor, pdp1) have been associated with HSC hyperproliferation, leukemia, and accelerated aging. Pathway analyses also indicated an enrichment of genes associated with oxidative stress, acute myelogenous leukemia, aging, and heat shock response, and the β-catenin/Wnt pathways. These data indicate that loss of AhR and associated changes in multiple signaling pathways promote premature HSC exhaustion and development of a myeloproliferative disorder. They also implicate a critical role of the AhR in the regulation of HSCs.

  20. Integration of HPV6 and downregulation of AKR1C3 expression mark malignant transformation in a patient with juvenile-onset laryngeal papillomatosis.

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    Christian Ulrich Huebbers

    Full Text Available Juvenile-onset recurrent respiratory papillomatosis (RRP is associated with low risk human papillomavirus (HPV types 6 and 11. Malignant transformation has been reported solely for HPV11-associated RRP in 2-4% of all RRP-cases, but not for HPV6. The molecular mechanisms in the carcinogenesis of low risk HPV-associated cancers are to date unknown. We report of a female patient, who presented with a laryngeal carcinoma at the age of 24 years. She had a history of juvenile-onset RRP with an onset at the age of three and subsequently several hundred surgical interventions due to multiple recurrences of RRP. Polymerase chain reaction (PCR or bead-based hybridization followed by direct sequencing identified HPV6 in tissue sections of previous papilloma and the carcinoma. P16(INK4A, p53 and pRb immunostainings were negative in all lesions. HPV6 specific fluorescence in situ hybridization (FISH revealed nuclear staining suggesting episomal virus in the papilloma and a single integration site in the carcinoma. Integration-specific amplification of papillomavirus oncogene transcripts PCR (APOT-PCR showed integration in the aldo-keto reductase 1C3 gene (AKR1C3 on chromosome 10p15.1. ArrayCGH detected loss of the other gene copy as part of a deletion at 10p14-p15.2. Western blot analysis and immunohistochemistry of the protein AKR1C3 showed a marked reduction of its expression in the carcinoma. In conclusion, we identified a novel molecular mechanism underlying a first case of HPV6-associated laryngeal carcinoma in juvenile-onset RRP, i.e. that HPV6 integration in the AKR1C3 gene resulted in loss of its expression. Alterations of AKR1C gene expression have previously been implicated in the tumorigenesis of other (HPV-related malignancies.

  1. Identification and validation of human papillomavirus encoded microRNAs.

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    Kui Qian

    Full Text Available We report here identification and validation of the first papillomavirus encoded microRNAs expressed in human cervical lesions and cell lines. We established small RNA libraries from ten human papillomavirus associated cervical lesions including cancer and two human papillomavirus harboring cell lines. These libraries were sequenced using SOLiD 4 technology. We used the sequencing data to predict putative viral microRNAs and discovered nine putative papillomavirus encoded microRNAs. Validation was performed for five candidates, four of which were successfully validated by qPCR from cervical tissue samples and cell lines: two were encoded by HPV 16, one by HPV 38 and one by HPV 68. The expression of HPV 16 microRNAs was further confirmed by in situ hybridization, and colocalization with p16INK4A was established. Prediction of cellular target genes of HPV 16 encoded microRNAs suggests that they may play a role in cell cycle, immune functions, cell adhesion and migration, development, and cancer. Two putative viral target sites for the two validated HPV 16 miRNAs were mapped to the E5 gene, one in the E1 gene, two in the L1 gene and one in the LCR region. This is the first report to show that papillomaviruses encode their own microRNA species. Importantly, microRNAs were found in libraries established from human cervical disease and carcinoma cell lines, and their expression was confirmed in additional tissue samples. To our knowledge, this is also the first paper to use in situ hybridization to show the expression of a viral microRNA in human tissue.

  2. Inhibition of DNA methyltransferase induces G2 cell cycle arrest and apoptosis in human colorectal cancer cells via inhibition of JAK2/STAT3/STAT5 signalling.

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    Xiong, Hua; Chen, Zhao-Fei; Liang, Qin-Chuan; Du, Wan; Chen, Hui-Min; Su, Wen-Yu; Chen, Guo-Qiang; Han, Ze-Guang; Fang, Jing-Yuan

    2009-09-01

    DNA methyltransferase inhibitors (MTIs) have recently emerged as promising chemotherapeutic or preventive agents for cancer, despite their poorly characterized mechanisms of action. The present study shows that DNA methylation is integral to the regulation of SH2-containing protein tyrosine phosphatase 1 (SHP1) expression, but not for regulation of suppressors of cytokine signalling (SOCS)1 or SOCS3 in colorectal cancer (CRC) cells. SHP1 expression correlates with down-regulation of Janus kinase/signal transducers and activators of transcription (JAK2/STAT3/STAT5) signalling, which is mediated in part by tyrosine dephosphorylation events and modulation of the proteasome pathway. Up-regulation of SHP1 expression was achieved using a DNA MTI, 5-aza-2'-deoxycytidine (5-aza-dc), which also generated significant down-regulation of JAK2/STAT3/STAT5 signalling. We demonstrate that 5-aza-dc suppresses growth of CRC cells, and induces G2 cell cycle arrest and apoptosis through regulation of downstream targets of JAK2/STAT3/STAT5 signalling including Bcl-2, p16(ink4a), p21(waf1/cip1) and p27(kip1). Although 5-aza-dc did not significantly inhibit cell invasion, 5-aza-dc did down-regulate expression of focal adhesion kinase and vascular endothelial growth factor in CRC cells. Our results demonstrate that 5-aza-dc can induce SHP1 expression and inhibit JAK2/STAT3/STAT5 signalling. This study represents the first evidence towards establishing a mechanistic link between inhibition of JAK2/STAT3/STAT5 signalling and the anticancer action of 5-aza-dc in CRC cells that may lead to the use of MTIs as a therapeutic intervention for human colorectal cancer.

  3. Trichostatin A, a histone deacetylase inhibitor, suppresses JAK2/STAT3 signaling via inducing the promoter-associated histone acetylation of SOCS1 and SOCS3 in human colorectal cancer cells.

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    Xiong, Hua; Du, Wan; Zhang, Yan-Jie; Hong, Jie; Su, Wen-Yu; Tang, Jie-Ting; Wang, Ying-Chao; Lu, Rong; Fang, Jing-Yuan

    2012-02-01

    Aberrant janus kinase/signal transducers and activators of transcription (JAK/STAT) signaling is involved in the oncogenesis of several cancers. Suppressors of cytokine signaling (SOCS) genes and SH2-containing protein tyrosine phosphatase 1 (SHP1) proteins, which are negative regulators of JAK/STAT signaling, have been reported to have tumor suppressor functions. However, in colorectal cancer (CRC) cells, the mechanisms that regulate SOCS and SHP1 genes, and the cause of abnormalities in the JAK/STAT signaling pathway, remain largely unknown. The present study shows that trichostatin A (TSA), a histone deacetylase (HDAC) inhibitor, leads to the hyperacetylation of histones associated with the SOCS1 and SOCS3 promoters, but not the SHP1 promoter in CRC cells. This indicates that histone modifications are involved in the regulation of SOCS1 and SOCS3. Moreover, upregulation of SOCS1 and SOCS3 expression was achieved using TSA, which also significantly downregulated JAK2/STAT3 signaling in CRC cells. We also demonstrate that TSA suppresses the growth of CRC cells, and induces G1 cell cycle arrest and apoptosis through the regulation of downstream targets of JAK2/STAT3 signaling, including Bcl-2, survivin and p16(ink4a) . Therefore, our data demonstrate that TSA may induce SOCS1 and SOCS3 expression by inducing histone modifications and consequently inhibits JAK2/STAT3 signaling in CRC cells. These results also establish a mechanistic link between the inhibition of JAK2/STAT3 signaling and the anticancer action of TSA in CRC cells. Copyright © 2011 Wiley Periodicals, Inc.

  4. Establishment of a new human pleomorphic malignant fibrous histiocytoma cell line, FU-MFH-2: molecular cytogenetic characterization by multicolor fluorescence in situ hybridization and comparative genomic hybridization

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    Isayama Teruto

    2010-11-01

    Full Text Available Abstract Background Pleomorphic malignant fibrous histiocytoma (MFH is one of the most frequent malignant soft tissue tumors in adults. Despite the considerable amount of research on MFH cell lines, their characterization at a molecular cytogenetic level has not been extensively analyzed. Methods and results We established a new permanent human cell line, FU-MFH-2, from a metastatic pleomorphic MFH of a 72-year-old Japanese man, and applied multicolor fluorescence in situ hybridization (M-FISH, Urovysion™ FISH, and comparative genomic hybridization (CGH for the characterization of chromosomal aberrations. FU-MFH-2 cells were spindle or polygonal in shape with oval nuclei, and were successfully maintained in vitro for over 80 passages. The histological features of heterotransplanted tumors in severe combined immunodeficiency mice were essentially the same as those of the original tumor. Cytogenetic and M-FISH analyses displayed a hypotriploid karyotype with numerous structural aberrations. Urovysion™ FISH revealed a homozygous deletion of the p16INK4A locus on chromosome band 9p21. CGH analysis showed a high-level amplification of 9q31-q34, gains of 1p12-p34.3, 2p21, 2q11.2-q21, 3p, 4p, 6q22-qter, 8p11.2, 8q11.2-q21.1, 9q21-qter, 11q13, 12q24, 15q21-qter, 16p13, 17, 20, and X, and losses of 1q43-qter, 4q32-qter, 5q14-q23, 7q32-qter, 8p21-pter, 8q23, 9p21-pter, 10p11.2-p13, and 10q11.2-q22. Conclusion The FU-MFH-2 cell line will be a particularly useful model for studying molecular pathogenesis of human pleomorphic MFH.

  5. A systematic review and meta-analysis on the attribution of human papillomavirus (HPV) in neuroendocrine cancers of the cervix.

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    Castle, Philip E; Pierz, Amanda; Stoler, Mark H

    2018-02-01

    There remains uncertainty about the role of human papillomavirus (HPV) infection in causing small-cell neuroendocrine carcinoma (SCNC) and large-cell neuroendocrine carcinoma (LCNC) of the cervix. To clarify the role of HPV in the development of SCNC and LCNC, we conducted a systematic review and meta-analyses. PubMed and Embase were searched to initially identify 143 articles published on or before June 1, 2017. Studies were limited to methods that tested for HPV in the cancer tissue directly to minimize misattribution. Thirty-two studies with 403 SCNC and 9 studies of 45 LCNC were included in the analysis. For SCNC, 85% (95% confidence interval [95%CI]=71%-94%) were HPV positive, 78% (95%CI=64%-90%) were HPV16 and/or HPV18 positive, 51% (95%CI=39%-64%) were singly HPV18 positive, and 10% (95%CI=4%-19%) were singly HPV16 positive. In a subset of 5 SCNC studies (75 cases), 93% were positive for p16 INK4a by immunohistochemistry and 100% were HPV positive. For LCNC, 88% (95%CI=72%-99%) were HPV positive, 86% (95%CI=70%-98%) were positive for HPV16 or HPV18, 30% were singly HPV18 positive (95%CI=4%-60%), and 29% (95%CI=2%-64%) were singly HPV16 positive. In conclusion, most SCNC and LCNC are caused by HPV, primarily HPV18 and HPV16. Therefore, most if not all SCNC and LCNC will be prevented by currently available prophylactic HPV vaccines. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Stratification and Prognostic Relevance of Jass’s Molecular Classification of Colorectal Cancer

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    Zlobec, Inti; Bihl, Michel P.; Foerster, Anja; Rufle, Alex; Terracciano, Luigi; Lugli, Alessandro

    2012-01-01

    Background: The current proposed model of colorectal tumorigenesis is based primarily on CpG island methylator phenotype (CIMP), microsatellite instability (MSI), KRAS, BRAF, and methylation status of 0-6-Methylguanine DNA Methyltransferase (MGMT) and classifies tumors into five subgroups. The aim of this study is to validate this molecular classification and test its prognostic relevance. Methods: Three hundred two patients were included in this study. Molecular analysis was performed for five CIMP-related promoters (CRABP1, MLH1, p16INK4a, CACNA1G, NEUROG1), MGMT, MSI, KRAS, and BRAF. Methylation in at least 4 promoters or in one to three promoters was considered CIMP-high and CIMP-low (CIMP-H/L), respectively. Results: CIMP-H, CIMP-L, and CIMP-negative were found in 7.1, 43, and 49.9% cases, respectively. One hundred twenty-three tumors (41%) could not be classified into any one of the proposed molecular subgroups, including 107 CIMP-L, 14 CIMP-H, and two CIMP-negative cases. The 10 year survival rate for CIMP-high patients [22.6% (95%CI: 7–43)] was significantly lower than for CIMP-L or CIMP-negative (p = 0.0295). Only the combined analysis of BRAF and CIMP (negative versus L/H) led to distinct prognostic subgroups. Conclusion: Although CIMP status has an effect on outcome, our results underline the need for standardized definitions of low- and high-level CIMP, which clearly hinders an effective prognostic and molecular classification of colorectal cancer.

  7. Combined Analysis of COX-2 and p53 Expressions Reveals Synergistic Inverse Correlations with Microsatellite Instability and CpG Island Methylator Phenotype in Colorectal Cancer

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    Shuji Ogino

    2006-06-01

    Full Text Available Cyclooxygenase-2 (COX-2 overexpression and mutations of p53 (a known COX-2 regulator are inversely associated with microsatellite instability—high (MSI-H and CpG island methylator phenotype (CIMP, characterized by extensive promoter methylation, is associated with MSI-H. However, no studies have comprehensively examined interrelations between COX-2, p53, MSI, and CIMP. Using MethyLight, we measured DNA methylation in five CIMP-specific gene promoters [CACNA1G, CDKN2A (p16/INK4A, CRABP1, MLH1, and NEUROG1] in relatively unbiased samples of 751 colorectal cancer cases obtained from two large prospective cohorts; 115 (15% tumors were CIMP-high (≥ 4 of 5 methylated promoters, 251 (33% were CIMP-low (1 to 3 methylated promoters, and the remaining 385 (51% were CIMP-0 (no methylated promoters. CIMP-high tumors were much less frequent in COX-2+/p53+ tumors (4.6% than in COX-2+/p53- tumors (19%; P < .0001, COX-2-/p53+ tumors (17%; P = .04, and COX-2-/p53- tumors (28%; P < .0001. In addition, COX-2+/p53+ tumors were significantly less common in MSI-H CIMP-high tumors (9.7% than in non-MSI-H CIMP-low/CIMP-0 tumors (44–47%; P < .0001. In conclusion, COX-2 and p53 alterations were synergistically inversely correlated with both MSI-H and CIMP-high. Our data suggest that a combined analysis of COX-2 and p53 may be more useful for the molecular classification of colorectal cancer than either COX-2 or p53 analysis alone.

  8. Large-scale analysis of protein expression changes in human keratinocytes immortalized by human papilloma virus type 16 E6 and E7 oncogenes

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    Arnouk Hilal

    2009-08-01

    Full Text Available Abstract Background Infection with high-risk type human papilloma viruses (HPVs is associated with cervical carcinomas and with a subset of head and neck squamous cell carcinomas. Viral E6 and E7 oncogenes cooperate to achieve cell immortalization by a mechanism that is not yet fully understood. Here, human keratinocytes were immortalized by long-term expression of HPV type 16 E6 or E7 oncoproteins, or both. Proteomic profiling was used to compare expression levels for 741 discrete protein features. Results Six replicate measurements were performed for each group using two-dimensional difference gel electrophoresis (2D-DIGE. The median within-group coefficient of variation was 19–21%. Significance of between-group differences was tested based on Significance Analysis of Microarray and fold change. Expression of 170 (23% of the protein features changed significantly in immortalized cells compared to primary keratinocytes. Most of these changes were qualitatively similar in cells immortalized by E6, E7, or E6/7 expression, indicating convergence on a common phenotype, but fifteen proteins (~2% were outliers in this regulatory pattern. Ten demonstrated opposite regulation in E6- and E7-expressing cells, including the cell cycle regulator p16INK4a; the carbohydrate binding protein Galectin-7; two differentially migrating forms of the intermediate filament protein Cytokeratin-7; HSPA1A (Hsp70-1; and five unidentified proteins. Five others had a pattern of expression that suggested cooperativity between the co-expressed oncoproteins. Two of these were identified as forms of the small heat shock protein HSPB1 (Hsp27. Conclusion This large-scale analysis provides a framework for understanding the cooperation between E6 and E7 oncoproteins in HPV-driven carcinogenesis.

  9. Expression of arf tumor suppressor in spermatogonia facilitates meiotic progression in male germ cells.

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    Michelle L Churchman

    2011-07-01

    Full Text Available The mammalian Cdkn2a (Ink4a-Arf locus encodes two tumor suppressor proteins (p16(Ink4a and p19(Arf that respectively enforce the anti-proliferative functions of the retinoblastoma protein (Rb and the p53 transcription factor in response to oncogenic stress. Although p19(Arf is not normally detected in tissues of young adult mice, a notable exception occurs in the male germ line, where Arf is expressed in spermatogonia, but not in meiotic spermatocytes arising from them. Unlike other contexts in which the induction of Arf potently inhibits cell proliferation, expression of p19(Arf in spermatogonia does not interfere with mitotic cell division. Instead, inactivation of Arf triggers germ cell-autonomous, p53-dependent apoptosis of primary spermatocytes in late meiotic prophase, resulting in reduced sperm production. Arf deficiency also causes premature, elevated, and persistent accumulation of the phosphorylated histone variant H2AX, reduces numbers of chromosome-associated complexes of Rad51 and Dmc1 recombinases during meiotic prophase, and yields incompletely synapsed autosomes during pachynema. Inactivation of Ink4a increases the fraction of spermatogonia in S-phase and restores sperm numbers in Ink4a-Arf doubly deficient mice but does not abrogate γ-H2AX accumulation in spermatocytes or p53-dependent apoptosis resulting from Arf inactivation. Thus, as opposed to its canonical role as a tumor suppressor in inducing p53-dependent senescence or apoptosis, Arf expression in spermatogonia instead initiates a salutary feed-forward program that prevents p53-dependent apoptosis, contributing to the survival of meiotic male germ cells.

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

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    Hemant Varma

    2007-12-01

    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.

  11. In vitro modeling of human pancreatic duct epithelial cell transformation defines gene expression changes induced by K-ras oncogenic activation in pancreatic carcinogenesis.

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    Qian, Jiaying; Niu, Jiangong; Li, Ming; Chiao, Paul J; Tsao, Ming-Sound

    2005-06-15

    Genetic analysis of pancreatic ductal adenocarcinomas and their putative precursor lesions, pancreatic intraepithelial neoplasias (PanIN), has shown a multistep molecular paradigm for duct cell carcinogenesis. Mutational activation or inactivation of the K-ras, p16(INK4A), Smad4, and p53 genes occur at progressive and high frequencies in these lesions. Oncogenic activation of the K-ras gene occurs in >90% of pancreatic ductal carcinoma and is found early in the PanIN-carcinoma sequence, but its functional roles remain poorly understood. We show here that the expression of K-ras(G12V) oncogene in a near diploid HPV16-E6E7 gene immortalized human pancreatic duct epithelial cell line originally derived from normal pancreas induced the formation of carcinoma in 50% of severe combined immunodeficient mice implanted with these cells. A tumor cell line established from one of these tumors formed ductal cancer when implanted orthotopically. These cells also showed increased activation of the mitogen-activated protein kinase, AKT, and nuclear factor-kappaB pathways. Microarray expression profiling studies identified 584 genes whose expression seemed specifically up-regulated by the K-ras oncogene expression. Forty-two of these genes have been reported previously as differentially overexpressed in pancreatic cancer cell lines or primary tumors. Real-time PCR confirmed the overexpression of a large number of these genes. Immunohistochemistry done on tissue microarrays constructed from PanIN and pancreatic cancer samples showed laminin beta3 overexpression starting in high-grade PanINs and occurring in >90% of pancreatic ductal carcinoma. The in vitro modeling of human pancreatic duct epithelial cell transformation may provide mechanistic insights on gene expression changes that occur during multistage pancreatic duct cell carcinogenesis.

  12. The effect of solar ultraviolet radiation (UVR on induction of skin cancers

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    Marta Pacholczyk

    2016-04-01

    Full Text Available Ultraviolet radiation is a physical mutagenic and cancerogenic factor. About 95% of ultraviolet A (UVA (320–400 nm and 5% of UVB (280–320 nm reach the Earth’s surface. Melanin is a natural skin protective factor against UV radiation. Skin cancers associated with long-term exposure to UV radiation are: basal cell carcinoma (BCC, squamous cell carcinoma (SCC and cutaneous malignant melanoma (CMM. The high risk of BCC development is related to acute and repeated exposure to UV causing sunburn. Molecular studies of BBC demonstrated disorders in sonic hedgehog (SHH cell signaling regulation pathway, associated with the suppressor protein patched homolog 1 gene (PTCH1 mutations. The risk of the BCC development is related to the polymorphism of melanokortin-1 receptor gene (MC1R. Tumor P53 gene mutations observed in BCC cells has been classified as secondary genetic changes. In SCC cells UV-induced mutations were mostly related to P53 gene. Increased expression of cyclooxigenase- 2 gene (COX-2 plays a significant role in the development of SCC. Other pathogenetic factors include intensification of the synthesis of pro-inflammatory cytokines (tumor necrosis factor α (TNF-α, interleukin-1 α (IL-1α, IL-1β and IL-6. Currently, the role of UVB has been recognized in the pathogenesis of CMM. In CMM cells the following gene mutations were noted: cyclindependent kinase inhibitor 2A INK4A (p16INK4A, cyclin-dependent kinase 4 (CDK4, Ras, phosphatase and tensin homolog deleted on chromosome 10 (PTEN and proto-oncogene B-Raf (BRAF. The BRAF gene mutations were observed in ~50% of CMM cases. Mutations of P53 gene are not characteristic of CMM cells. Med Pr 2016;67(2:255–266

  13. Human Papillomavirus 16 Infection and TP53 Mutation: Two Distinct Pathogeneses for Oropharyngeal Squamous Cell Carcinoma in an Eastern Chinese Population.

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    Wang, Zhen; Xia, Rong-Hui; Ye, Dong-Xia; Li, Jiang

    2016-01-01

    To investigate the clinicopathological characteristics, human papillomavirus (HPV) infection, p53 expression, and TP53 mutations in oropharyngeal squamous cell carcinoma (OPSCC) and determine their utility as prognostic predictors in a primarily eastern Chinese population. The HPV infection status was tested via p16INK4A immunohistochemistry and validated using PCR, reverse blot hybridization and in situ hybridization (ISH) in 188 OPSCC samples. p53 expression levels and TP53 gene mutations were assessed through immunohistochemistry and sequencing, respectively. Clinicopathological characteristics and follow-up information were collected. Overall survival was estimated using the Log-rank test. Overall, 22 of the 188 OPSCC samples were associated with HPV infection. HPV16 was identified in all 22 samples, whereas no samples were positive for HPV18. All 22 HPV-associated OPSCC samples were p53 negative and lacked TP53 mutations. HPV16 positivity, female patients, non-smokers, and patients with histological grade I and stage N0 diseases showed better overall survival (p = 0.009, 0.003, 0.048, 0.009, and 0.004, respectively). No significant differences in overall survival between smoking and non-smoking patients were observed in the HPV-associated OPSCC group. Patients without mutations in TP53 exons 5-8 had better prognoses (p = 0.031) among the 43 sequenced specimens. Multivariate analysis indicated that HPV16 infection status (p = 0.011), histological grade (p = 0.017), and N stage (p = 0.019) were independent prognostic factors for patients with OPSCC. Distinct from the situation in Europe and America, for the patients with OPSCC in this study, HPV16 infection was relatively low, although it was still the most important independent prognostic predictor for the disease. In addition to the high smoking and drinking rate in this population, HPV16 infection and TP53 dysfunction appear to be two distinct pathogens for OPSCC patients in the eastern Chinese population.

  14. Laryngeal squamous cell papilloma is highly associated with human papillomavirus.

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    Orita, Yorihisa; Gion, Yuka; Tachibana, Tomoyasu; Ikegami, Kana; Marunaka, Hidenori; Makihara, Seiichiro; Yamashita, Yasuhiko; Miki, Kentaro; Makino, Takuma; Akisada, Naoki; Akagi, Yusuke; Kimura, Miyuki; Yoshino, Tadashi; Nishizaki, Kazunori; Sato, Yasuharu

    2018-04-01

    To delineate the association between characteristics of adult-onset laryngeal squamous cell papilloma and human papillomavirus (HPV) infection. Clinical records and paraffin-embedded specimens of 77 papilloma patients who had been treated between 1998 and 2014 were collected. Of the 77 cases, 34 were identified in the larynx, 28 in the oral cavity and 15 in the oropharynx. Specimens were investigated by polymerase chain reaction (PCR) to detect HPV 6, 11, 16, 18, 31, 33, 35, 52b and 58, and immunohistochemical (IHC) staining for anti-p16INK4a antibody. In 21 cases (61.8%) with laryngeal squamous cell papilloma, various types of HPV were detected: 14 cases (41.2%) were positive of high-risk HPV, 18 (52.9%) were positive of low-risk HPV and 11 (32.4%) were positive of both high-risk HPV and low-risk HPV. Younger patients (papilloma, no malignant transformation was observed during the study period. With IHC staining, positive expression of p16 was observed in 20 cases (58.8%). HPV infection and p16-expression were associated with the pathological finding of koilocytosis. Only four cases (14.3%) showed HPV-positivity in the oral cavity, and none of the 15 oropharyngeal cases were positive for HPV, and none of the oral cavity and oropharyngeal cases showed koilocytosis. Results of HPV-PCR and p16-IHC staining were significantly correlated each other. HPV infection is frequently associated with laryngeal squamous cell papilloma, and koilocytosis is a characteristic pathological finding. To the best of our knowledge, this is the first report which have described infections with multiple HPV types in laryngeal papilloma.

  15. Evaluating the physiological reserves of older patients with cancer: the value of potential biomarkers of aging?

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    Pallis, Athanasios G; Hatse, Sigrid; Brouwers, Barbara; Pawelec, Graham; Falandry, Claire; Wedding, Ulrich; Lago, Lissandra Dal; Repetto, Lazzaro; Ring, Alistair; Wildiers, Hans

    2014-04-01

    Aging of an individual entails a progressive decline of functional reserves and loss of homeostasis that eventually lead to mortality. This process is highly individualized and is influenced by multiple genetic, epigenetic and environmental factors. This individualization and the diversity of factors influencing aging result in a significant heterogeneity among people with the same chronological age, representing a major challenge in daily oncology practice. Thus, many factors other than mere chronological age will contribute to treatment tolerance and outcome in the older patients with cancer. Clinical/comprehensive geriatric assessment can provide information on the general health status of individuals, but is far from perfect as a prognostic/predictive tool for individual patients. On the other hand, aging can also be assessed in terms of biological changes in certain tissues like the blood compartment which result from adaptive alterations due to past history of exposures, as well as intrinsic aging processes. There are major signs of 'aging' in lymphocytes (e.g. lymphocyte subset distribution, telomere length, p16INK4A expression), and also in (inflammatory) cytokine expression and gene expression patterns. These result from a combination of the above two processes, overlaying genetic predispositions which contribute significantly to the aging phenotype. These potential "aging biomarkers" might provide additional prognostic/predictive information supplementing clinical evaluation. The purpose of the current paper is to describe the most relevant potential "aging biomarkers" (markers that indicate the biological functional age of patients) which focus on the biological background, the (limited) available clinical data, and technical challenges. Despite their great potential interest, there is a need for much more (validated) clinical data before these biomarkers could be used in a routine clinical setting. This manuscript tries to provide a guideline on how

  16. p16/ki-67 dual-stain cytology in the triage of ASCUS and LSIL papanicolaou cytology: results from the European equivocal or mildly abnormal Papanicolaou cytology study.

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    Schmidt, Dietmar; Bergeron, Christine; Denton, Karin J; Ridder, Ruediger

    2011-06-25

    The objective of this study was to analyze the diagnostic performance of a newly established immunocytochemical dual-stain protocol, which simultaneously detects p16(INK4a) and Ki-67 expression in cervical cytology samples, for identifying high-grade cervical intraepithelial neoplasia (CIN2+) in women with Papanicolaou (Pap) cytology results categorized as atypical squamous cells of undetermined significance (ASCUS) or low-grade squamous intraepithelial lesions (LSIL). Residual liquid-based cytology material from 776 retrospectively collected ASCUS/LSIL cases that were available from a recent study evaluating p16 cytology and HPV testing were subjected to p16/Ki-67 dual staining. The presence of 1 or more double-immunoreactive cell(s) was regarded as a positive test outcome, irrespective of morphology. Test results were correlated to histology follow-up. Sensitivity of p16/Ki-67 dual-stain cytology for biopsy-confirmed CIN2+ was 92.2% (ASCUS) and 94.2% (LSIL), while specificity rates were 80.6% (ASCUS) and 68.0% (LSIL), respectively. Similar sensitivity/specificity profiles were found for both age groups of women aged aged ≥30 years. Dual-stain cytology showed comparable sensitivity, but significantly higher specificity, when compared with human papillomavirus (HPV) testing. The results of this study show that p16/Ki-67 dual-stain cytology provided a high sensitivity for the detection of underlying CIN2+ in women with ASCUS or LSIL Pap cytology results, comparable to the rates previously reported for HPV testing and p16 single-stain cytology. However, the specificity of this morphology-independent interpretation of p16/Ki-67 dual-stain cytology testing was further improved compared with the earlier p16 single-stain cytology approach, which required morphology interpretation, and it is significantly higher when compared with HPV testing. Copyright © 2011 American Cancer Society.

  17. Quantitation of Human Papillomavirus DNA in Plasma of Oropharyngeal Carcinoma Patients

    International Nuclear Information System (INIS)

    Cao Hongbin; Banh, Alice; Kwok, Shirley; Shi Xiaoli; Wu, Simon; Krakow, Trevor; Khong, Brian; Bavan, Brindha; Bala, Rajeev; Pinsky, Benjamin A.; Colevas, Dimitrios; Pourmand, Nader; Koong, Albert C.; Kong, Christina S.; Le, Quynh-Thu

    2012-01-01

    Purpose: To determine whether human papillomavirus (HPV) DNA can be detected in the plasma of patients with HPV-positive oropharyngeal carcinoma (OPC) and to monitor its temporal change during radiotherapy. Methods and Materials: We used polymerase chain reaction to detect HPV DNA in the culture media of HPV-positive SCC90 and VU147T cells and the plasma of SCC90 and HeLa tumor-bearing mice, non-tumor-bearing controls, and those with HPV-negative tumors. We used real-time quantitative polymerase chain reaction to quantify the plasma HPV DNA in 40 HPV-positive OPC, 24 HPV-negative head-and-neck cancer patients and 10 non-cancer volunteers. The tumor HPV status was confirmed by p16 INK4a staining and HPV16/18 polymerase chain reaction or HPV in situ hybridization. A total of 14 patients had serial plasma samples for HPV DNA quantification during radiotherapy. Results: HPV DNA was detectable in the plasma samples of SCC90- and HeLa-bearing mice but not in the controls. It was detected in 65% of the pretreatment plasma samples from HPV-positive OPC patients using E6/7 quantitative polymerase chain reaction. None of the HPV-negative head-and-neck cancer patients or non-cancer controls had detectable HPV DNA. The pretreatment plasma HPV DNA copy number correlated significantly with the nodal metabolic tumor volume (assessed using 18 F-deoxyglucose positron emission tomography). The serial measurements in 14 patients showed a rapid decline in HPV DNA that had become undetectable at radiotherapy completion. In 3 patients, the HPV DNA level had increased to a discernable level at metastasis. Conclusions: Xenograft studies indicated that plasma HPV DNA is released from HPV-positive tumors. Circulating HPV DNA was detectable in most HPV-positive OPC patients. Thus, plasma HPV DNA might be a valuable tool for identifying relapse.

  18. BMI1 and Mel-18 oppositely regulate carcinogenesis and progression of gastric cancer.

    Science.gov (United States)

    Zhang, Xiao-Wei; Sheng, Ya-Ping; Li, Qian; Qin, Wei; Lu, You-Wei; Cheng, Yu-Fan; Liu, Bing-Ya; Zhang, Feng-Chun; Li, Jin; Dimri, Goberdhan P; Guo, Wei-Jian

    2010-02-21

    The BMI1 oncogene is overexpressed in several human malignancies including gastric cancer. In addition to BMI1, mammalian cells also express Mel-18, which is closely related to BMI1. We have reported that Mel-18 functions as a potential tumor suppressor by repressing the expression of BMI1 and consequent downregulation of activated AKT in breast cancer cells. However, the mechanisms of BMI1 overexpression and the role of Mel-18 in other cancers are still not clear. The purpose of this study is to investigate the role of BMI1 and Mel-18 in gastric cancer. BMI1 was found to be overexpressed in gastric cancer cell lines and gastric tumors. Overexpression of BMI1 correlated with advanced clinical stage and lymph node metastasis; while the expression of Mel-18 negatively correlated with BMI1. BMI1 but not Mel-18 was found to be an independent prognostic factor. Downregulation of BMI1 by Mel-18 overexpression or knockdown of BMI1 expression in gastric cancer cell lines led to upregulation of p16 (p16INK4a or CDKN2A) in p16 positive cell lines and reduction of phospho-AKT in both p16-positive and p16-negative cell lines. Downregulation of BMI1 was also accompanied by decreased transformed phenotype and migration in both p16- positive and p16-negative gastric cancer cell lines. In the context of gastric cancer, BMI1 acts as an oncogene and Mel-18 functions as a tumor suppressor via downregulation of BMI1. Mel-18 and BMI1 may regulate tumorigenesis, cell migration and cancer metastasis via both p16- and AKT-dependent growth regulatory pathways.

  19. Epigenetic regulation of multiple tumor-related genes leads to suppression of breast tumorigenesis by dietary genistein.

    Directory of Open Access Journals (Sweden)

    Yuanyuan Li

    Full Text Available Breast cancer is one of the most lethal diseases in women; however, the precise etiological factors are still not clear. Genistein (GE, a natural isoflavone found in soybean products, is believed to be a potent chemopreventive agent for breast cancer. One of the most important mechanisms for GE inhibition of breast cancer may involve its potential in impacting epigenetic processes allowing reversal of aberrant epigenetic events during breast tumorigenesis. To investigate epigenetic regulation for GE impedance of breast tumorigenesis, we monitored epigenetic alterations of several key tumor-related genes in an established breast cancer transformation system. Our results show that GE significantly inhibited cell growth in a dose-dependent manner in precancerous breast cells and breast cancer cells, whereas it exhibited little effect on normal human mammary epithelial cells. Furthermore, GE treatment increased expression of two crucial tumor suppressor genes, p21(WAF1 (p21 and p16(INK4a (p16, although it decreased expression of two tumor promoting genes, BMI1 and c-MYC. GE treatment led to alterations of histone modifications in the promoters of p21 and p16 as well as the binding ability of the c-MYC-BMI1 complex to the p16 promoter contributing to GE-induced epigenetic activation of these tumor suppressor genes. In addition, an orally-fed GE diet prevented breast tumorigenesis and inhibited breast cancer development in breast cancer mice xenografts. Our results suggest that genistein may repress early breast tumorigenesis by epigenetic regulation of p21 and p16 by impacting histone modifications as well as the BMI1-c-MYC complex recruitment to the regulatory region in the promoters of these genes. These studies will facilitate more effective use of soybean product in breast cancer prevention and also help elucidate the mechanisms during the process of early breast tumorigenesis.

  20. Epigenetic regulation of multiple tumor-related genes leads to suppression of breast tumorigenesis by dietary genistein.

    Science.gov (United States)

    Li, Yuanyuan; Chen, Huaping; Hardy, Tabitha M; Tollefsbol, Trygve O

    2013-01-01

    Breast cancer is one of the most lethal diseases in women; however, the precise etiological factors are still not clear. Genistein (GE), a natural isoflavone found in soybean products, is believed to be a potent chemopreventive agent for breast cancer. One of the most important mechanisms for GE inhibition of breast cancer may involve its potential in impacting epigenetic processes allowing reversal of aberrant epigenetic events during breast tumorigenesis. To investigate epigenetic regulation for GE impedance of breast tumorigenesis, we monitored epigenetic alterations of several key tumor-related genes in an established breast cancer transformation system. Our results show that GE significantly inhibited cell growth in a dose-dependent manner in precancerous breast cells and breast cancer cells, whereas it exhibited little effect on normal human mammary epithelial cells. Furthermore, GE treatment increased expression of two crucial tumor suppressor genes, p21(WAF1) (p21) and p16(INK4a) (p16), although it decreased expression of two tumor promoting genes, BMI1 and c-MYC. GE treatment led to alterations of histone modifications in the promoters of p21 and p16 as well as the binding ability of the c-MYC-BMI1 complex to the p16 promoter contributing to GE-induced epigenetic activation of these tumor suppressor genes. In addition, an orally-fed GE diet prevented breast tumorigenesis and inhibited breast cancer development in breast cancer mice xenografts. Our results suggest that genistein may repress early breast tumorigenesis by epigenetic regulation of p21 and p16 by impacting histone modifications as well as the BMI1-c-MYC complex recruitment to the regulatory region in the promoters of these genes. These studies will facilitate more effective use of soybean product in breast cancer prevention and also help elucidate the mechanisms during the process of early breast tumorigenesis.

  1. Aberrant DNA methylation of cancer-related genes in giant breast fibroadenoma: a case report

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    Orozco Javier I

    2011-10-01

    Full Text Available Abstract Introduction Giant fibroadenoma is an uncommon variant of benign breast lesions. Aberrant methylation of CpG islands in promoter regions is known to be involved in the silencing of genes (for example, tumor-suppressor genes and appears to be an early event in the etiology of breast carcinogenesis. Only hypermethylation of p16INK4a has been reported in non-giant breast fibroadenoma. In this particular case, there are no previously published data on epigenetic alterations in giant fibroadenomas. Our previous results, based on the analysis of 49 cancer-related CpG islands have confirmed that the aberrant methylation is specific to malignant breast tumors and that it is completely absent in normal breast tissue and breast fibroadenomas. Case presentation A 13-year-old Hispanic girl was referred after she had noted a progressive development of a mass in her left breast. On physical examination, a 10 × 10 cm lump was detected and axillary lymph nodes were not enlarged. After surgical removal the lump was diagnosed as a giant fibroadenoma. Because of the high growth rate of this benign tumor, we decided to analyze the methylation status of 49 CpG islands related to cell growth control. We have identified the methylation of five cancer-related CpG islands in the giant fibroadenoma tissue: ESR1, MGMT, WT-1, BRCA2 and CD44. Conclusion In this case report we show for the first time the methylation analysis of a giant fibroadenoma. The detection of methylation of these five cancer-related regions indicates substantial epigenomic differences with non-giant fibroadenomas. Epigenetic alterations could explain the higher growth rate of this tumor. Our data contribute to the growing knowledge of aberrant methylation in breast diseases. In this particular case, there exist no previous data regarding the role of methylation in giant fibroadenomas, considered by definition as a benign breast lesion.

  2. Therapeutically targeting cyclin D1 in primary tumors arising from loss of Ini1

    Science.gov (United States)

    Smith, Melissa E.; Cimica, Velasco; Chinni, Srinivasa; Jana, Suman; Koba, Wade; Yang, Zhixia; Fine, Eugene; Zagzag, David; Montagna, Cristina; Kalpana, Ganjam V.

    2011-01-01

    Rhabdoid tumors (RTs) are rare, highly aggressive pediatric malignancies with poor prognosis and with no standard or effective treatment strategies. RTs are characterized by biallelic inactivation of the INI1 tumor suppressor gene. INI1 directly represses CCND1 and activates cyclin-dependent kinase (cdk) inhibitors p16Ink4a and p21CIP. RTs are exquisitely dependent on cyclin D1 for genesis and survival. To facilitate translation of unique therapeutic strategies, we have used genetically engineered, Ini1+/− mice for therapeutic testing. We found that PET can be used to noninvasively and accurately detect primary tumors in Ini1+/− mice. In a PET-guided longitudinal study, we found that treating Ini1+/− mice bearing primary tumors with the pan-cdk inhibitor flavopiridol resulted in complete and stable regression of some tumors. Other tumors showed resistance to flavopiridol, and one of the resistant tumors overexpressed cyclin D1, more than flavopiridol-sensitive cells. The concentration of flavopiridol used was not sufficient to down-modulate the high level of cyclin D1 and failed to induce cell death in the resistant cells. Furthermore, FISH and PCR analyses indicated that there is aneuploidy and increased CCND1 copy number in resistant cells. These studies indicate that resistance to flavopiridol may be correlated to elevated cyclin D1 levels. Our studies also indicate that Ini1+/− mice are valuable tools for testing unique therapeutic strategies and for understanding mechanisms of drug resistance in tumors that arise owing to loss of Ini1, which is essential for developing effective treatment strategies against these aggressive tumors. PMID:21173237

  3. Telomere dysfunction and chromosome structure modulate the contribution of individual chromosomes in abnormal nuclear morphologies

    International Nuclear Information System (INIS)

    Pampalona, J.; Soler, D.; Genesca, A.; Tusell, L.

    2010-01-01

    The cytokinesis-block micronucleus assay has emerged as a biomarker of chromosome damage relevant to cancer. Although it was initially developed to measure micronuclei, it is also useful for measuring nucleoplasmic bridges and nuclear buds. Abnormal nuclear morphologies are frequently observed in malignant tissues and short-term tumour cell cultures. Changes in chromosome structure and number resulting from chromosome instability are important factors in oncogenesis. Telomeres have become key players in the initiation of chromosome instability related to carcinogenesis by means of breakage-fusion-bridge cycles. To better understand the connection between telomere dysfunction and the appearance of abnormal nuclear morphologies, we have characterised the presence of micronuclei, nucleoplasmic bridges and nuclear buds in human mammary primary epithelial cells. These cells can proliferate beyond the Hayflick limit by spontaneously losing expression of the p16 INK4a protein. Progressive telomere shortening leads to the loss of the capping function, and the appearance of end-to-end chromosome fusions that can enter into breakage-fusion-bridge cycles generating massive chromosomal instability. In human mammary epithelial cells, different types of abnormal nuclear morphologies were observed, however only nucleoplasmatic bridges and buds increased significantly with population doublings. Fluorescent in situ hybridisation using centromeric and painting specific probes for chromosomes with eroded telomeres has revealed that these chromosomes are preferentially included in the different types of abnormal nuclear morphologies observed, thus reflecting their common origin. Accordingly, real-time imaging of cell divisions enabled us to determine that anaphase bridge resolution was mainly through chromatin breakage and the formation of symmetric buds in daughter nuclei. Few micronuclei emerged in this cell system thus validating the scoring of nucleoplasmic bridges and nuclear

  4. Telomere dysfunction and chromosome structure modulate the contribution of individual chromosomes in abnormal nuclear morphologies.

    Science.gov (United States)

    Pampalona, J; Soler, D; Genescà, A; Tusell, L

    2010-01-05

    The cytokinesis-block micronucleus assay has emerged as a biomarker of chromosome damage relevant to cancer. Although it was initially developed to measure micronuclei, it is also useful for measuring nucleoplasmic bridges and nuclear buds. Abnormal nuclear morphologies are frequently observed in malignant tissues and short-term tumour cell cultures. Changes in chromosome structure and number resulting from chromosome instability are important factors in oncogenesis. Telomeres have become key players in the initiation of chromosome instability related to carcinogenesis by means of breakage-fusion-bridge cycles. To better understand the connection between telomere dysfunction and the appearance of abnormal nuclear morphologies, we have characterised the presence of micronuclei, nucleoplasmic bridges and nuclear buds in human mammary primary epithelial cells. These cells can proliferate beyond the Hayflick limit by spontaneously losing expression of the p16(INK4a) protein. Progressive telomere shortening leads to the loss of the capping function, and the appearance of end-to-end chromosome fusions that can enter into breakage-fusion-bridge cycles generating massive chromosomal instability. In human mammary epithelial cells, different types of abnormal nuclear morphologies were observed, however only nucleoplasmatic bridges and buds increased significantly with population doublings. Fluorescent in situ hybridisation using centromeric and painting specific probes for chromosomes with eroded telomeres has revealed that these chromosomes are preferentially included in the different types of abnormal nuclear morphologies observed, thus reflecting their common origin. Accordingly, real-time imaging of cell divisions enabled us to determine that anaphase bridge resolution was mainly through chromatin breakage and the formation of symmetric buds in daughter nuclei. Few micronuclei emerged in this cell system thus validating the scoring of nucleoplasmic bridges and nuclear

  5. HIV and drug abuse mediate astrocyte senescence in a β-catenin-dependent manner leading to neuronal toxicity.

    Science.gov (United States)

    Yu, Chunjiang; Narasipura, Srinivas D; Richards, Maureen H; Hu, Xiu-Ti; Yamamoto, Bryan; Al-Harthi, Lena

    2017-10-01

    Emerging evidence suggests that cell senescence plays an important role in aging-associated diseases including neurodegenerative diseases. HIV leads to a spectrum of neurologic diseases collectively termed HIV-associated neurocognitive disorders (HAND). Drug abuse, particularly methamphetamine (meth), is a frequently abused psychostimulant among HIV+ individuals and its abuse exacerbates HAND. The mechanism by which HIV and meth lead to brain cell dysregulation is not entirely clear. In this study, we evaluated the impact of HIV and meth on astrocyte senescence using in vitro and several animal models. Astrocytes constitute up to 50% of brain cells and play a pivotal role in marinating brain homeostasis. We show here that HIV and meth induce significant senescence of primary human fetal astrocytes, as evaluated by induction of senescence markers (β-galactosidase and p16 INK 4A ), senescence-associated morphologic changes, and cell cycle arrest. HIV- and meth-mediated astrocyte senescence was also demonstrated in three small animal models (humanized mouse model of HIV/NSG-huPBMCs, HIV-transgenic rats, and in a meth administration rat model). Senescent astrocytes in turn mediated neuronal toxicity. Further, we show that β-catenin, a pro-survival/proliferation transcriptional co-activator, is downregulated by HIV and meth in human astrocytes and this downregulation promotes astrocyte senescence while induction of β-catenin blocks HIV- and meth-mediated astrocyte senescence. These studies, for the first time, demonstrate that HIV and meth induce astrocyte senescence and implicate the β-catenin pathway as potential therapeutic target to overcome astrocyte senescence. © 2017 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

  6. Inactivation of the DNA repair gene O6-methylguanine-DNA methyltransferase by promoter hypermethylation is associated with G to A mutations in K-ras in colorectal tumorigenesis.

    Science.gov (United States)

    Esteller, M; Toyota, M; Sanchez-Cespedes, M; Capella, G; Peinado, M A; Watkins, D N; Issa, J P; Sidransky, D; Baylin, S B; Herman, J G

    2000-05-01

    O6-methylguanine DNA methyltransferase (MGMT) is a DNA repair protein that removes mutagenic and cytotoxic adducts from the O6 position of guanine. O6-methylguanine mispairs with thymine during replication, and if the adduct is not removed, this results in conversion from a guanine-cytosine pair to an adenine-thymine pair. In vitro assays show that MGMT expression avoids G to A mutations and MGMT transgenic mice are protected against G to A transitions at ras genes. We have recently demonstrated that the MGMT gene is silenced by promoter methylation in many human tumors, including colorectal carcinomas. To study the relevance of defective MGMT function by aberrant methylation in relation to the presence of K-ras mutations, we studied 244 colorectal tumor samples for MGMT promoter hypermethylation and K-ras mutational status. Our results show a clear association between the inactivation of MGMT by promoter hypermethylation and the appearance of G to A mutations at K-ras: 71% (36 of 51) of the tumors displaying this particular type of mutation had abnormal MGMT methylation, whereas only 32% (12 of 37) of those with other K-ras mutations not involving G to A transitions and 35% (55 of 156) of the tumors without K-ras mutations demonstrated MGMT methylation (P = 0.002). In addition, MGMT loss associated with hypermethylation was observed in the small adenomas, including those that do not yet contain K-ras mutations. Hypermethylation of other genes such as p16INK4a and p14ARF was not associated with either MGMT hypermethylation or K-ras mutation. Our data suggest that epigenetic silencing of MGMT by promoter hypermethylation may lead to a particular genetic change in human cancer, specifically G to A transitions in the K-ras oncogene.

  7. Generation of mesenchymal stromal cells in the presence of platelet lysate: a phenotypic and functional comparison of umbilical cord blood- and bone marrow-derived progenitors

    Science.gov (United States)

    Avanzini, Maria Antonietta; Bernardo, Maria Ester; Cometa, Angela Maria; Perotti, Cesare; Zaffaroni, Nadia; Novara, Francesca; Visai, Livia; Moretta, Antonia; Del Fante, Claudia; Villa, Raffaella; Ball, Lynne M.; Fibbe, Willem E.; Maccario, Rita; Locatelli, Franco

    2009-01-01

    Background Mesenchymal stromal cells are employed in various different clinical settings in order to modulate immune response. However, relatively little is known about the mechanisms responsible for their immunomodulatory effects, which could be influenced by both the cell source and culture conditions. Design and Methods We tested the ability of a 5% platelet lysate-supplemented medium to support isolation and ex vivo expansion of mesenchymal stromal cells from full-term umbilical-cord blood. We also investigated the biological/functional properties of umbilical cord blood mesenchymal stromal cells, in comparison with platelet lysate-expanded bone marrow mesenchymal stromal cells. Results The success rate of isolation of mesenchymal stromal cells from umbilical cord blood was in the order of 20%. These cells exhibited typical morphology, immunophenotype and differentiation capacity. Although they have a low clonogenic efficiency, umbilical cord blood mesenchymal stromal cells may possess high proliferative potential. The genetic stability of these cells from umbilical cord blood was demonstrated by a normal molecular karyotype; in addition, these cells do not express hTERT and telomerase activity, do express p16ink4a protein and do not show anchorage-independent cell growth. Concerning alloantigen-specific immune responses, umbilical cord blood mesenchymal stromal cells were able to: (i) suppress T- and NK-lymphocyte proliferation, (ii) decrease cytotoxic activity and (iii) only slightly increase interleukin-10, while decreasing interferon-γ secretion, in mixed lymphocyte culture supernatants. While an indoleamine 2,3-dioxygenase-specific inhibitor did not reverse mesenchymal stromal cell-induced suppressive effects, a prostaglandin E2-specific inhibitor hampered the suppressive effect of both umbilical cord blood- and bone marrow-mesenchymal stromal cells on alloantigen-induced cytotoxic activity. Mesenchymal stromal cells from both sources expressed HLA

  8. Genetic analysis of radiation-induced mouse thymic lymphomas

    International Nuclear Information System (INIS)

    Kominami, R.; Wakabayashi, Y.; Niwa, O.

    2003-01-01

    Mouse thymic lymphomas are one of the classic models of radiation-induced malignancies, and the model has been used for the study of genes involved in carcinogenesis. ras oncogenes are the first isolate which undergoes mutations in 10 to 30 % of lymphomas, and p16INK4a and p19ARF in the INK4a-ARF locus are also frequently inactivated. In our previous study, the inactivation of Ikaros, a key regurator of lymphoid system, was found in those lymphomas, and it was suggested that there are other responsible genes yet to be discovered. On the other hand, genetic predisposition to radiation-induced lymphoma often differs in different strains, and this reflects the presence of low penetrance genes that can modify the impact of a given mutation. Little study of such modifiers or susceptibility genes has been performed, either. Recent availability of databases on mouse genome information and the power of mouse genetic system underline usefulness of the lymphoma model in search for novel genes involved, which may provide clues to molecular mechanisms of development of the radiogenic lymphoma and also genes involved in human lymphomas and other malignancies. Accordingly, we have carried out positional cloning for the two different types of tumor-related genes. In this symposium, our current progress is presented that includes genetic mapping of susceptibility/ resistance loci on mouse chromosomes 4, 5 and 19, and also functional analysis of a novel tumor suppressor gene, Rit1/Bcl11b, that has been isolated from allelic loss (LOH) mapping and sequence analysis for γ -ray induced mouse thymic lymphomas

  9. Flavopiridol induces apoptosis in glioma cell lines independent of retinoblastoma and p53 tumor suppressor pathway alterations by a caspase-independent pathway.

    Science.gov (United States)

    Alonso, Michelle; Tamasdan, Cristina; Miller, Douglas C; Newcomb, Elizabeth W

    2003-02-01

    Flavopiridol is a synthetic flavone, which inhibits growth in vitro and in vivo of several solid malignancies such as renal, prostate, and colon cancers. It is a potent cyclin-dependent kinase inhibitor presently in clinical trials. In this study, we examined the effect of flavopiridol on a panel of glioma cell lines having different genetic profiles: five of six have codeletion of p16(INK4a) and p14(ARF); three of six have p53 mutations; and one of six shows overexpression of mouse double minute-2 (MDM2) protein. Independent of retinoblastoma and p53 tumor suppressor pathway alterations, flavopiridol induced apoptosis in all cell lines but through a caspase-independent mechanism. No cleavage products for caspase 3 or its substrate poly(ADP-ribose) polymerase or caspase 8 were detected. The pan-caspase inhibitor Z-VAD-fmk did not inhibit flavopiridol-induced apoptosis. Mitochondrial damage measured by cytochrome c release and transmission electron microscopy was not observed in drug-treated glioma cells. In contrast, flavopiridol treatment induced translocation of apoptosis-inducing factor from the mitochondria to the nucleus. The proteins cyclin D(1) and MDM2 involved in the regulation of retinoblastoma and p53 activity, respectively, were down-regulated early after flavopiridol treatment. Given that MDM2 protein can confer oncogenic properties under certain circumstances, loss of MDM2 expression in tumor cells could promote increased chemosensitivity. After drug treatment, a low Bcl-2/Bax ratio was observed, a condition that may favor apoptosis. Taken together, the data indicate that flavopiridol has activity against glioma cell lines in vitro and should be considered for clinical development in the treatment of glioblastoma multiforme.

  10. CARCINOMA OF THE LARYNX AND HUMAN PAPILLOMA VIRUS INFECTION

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    Georgi N. Nikolov

    2016-03-01

    Full Text Available Background: Laryngeal carcinoma is one of the most common form of head and neck cancer. During the last two decades, it has been recognized that this cancer is causally related to human papillomavirus (HPV. Objective: We presented a study on prevalence of human papilloma viruses (HPV in patients with laryngeal carcinoma. Methods: This study consists of 43 patients with laryngeal carcinoma who were diagnosed and treated with surgical techniques in Department of Otorhinolaryngology, University Hospital, Pleven, Bulgaria. Immunohistochemistry of p16INK4a and Ki-67 were used to prove the relationship between high-risk-HPV (HR-HPV and carcinogenesis. Results: Papilloma virus infection with high-risk oncogenic types of HPV was determined in more than 39.5% of surgically treated patients with histologically proven laryngeal cancer. HPV-induced carcinogenesis was assumed in 17 (13.9% of all patients whose spouses were operated from cervical cancer. The patients with HPV-positive laryngeal carcinoma were younger than the others in the group (8 years on average. Risk factors for development of HPV-associated laryngeal carcinoma were related to higher number of sexual partners and the practice of oral sex. Frequently, in patients with HPV-associated laryngeal carcinoma we find data for so-called “family’s carcinogenesis”. The possibility of appearance (either preceding or following the treatment of a second carcinoma and/or tumour recurrence is higher in HPV-positive laryngeal carcinomas. Conclusion: It is recommended to extend the diagnostic methods for laryngeal and hypo pharyngeal cancer with a routine search for high-risk oncogenic HPV strains.

  11. K-Ras(V14I) -induced Noonan syndrome predisposes to tumour development in mice.

    Science.gov (United States)

    Hernández-Porras, Isabel; Schuhmacher, Alberto J; Garcia-Medina, Raquel; Jiménez, Beatriz; Cañamero, Marta; de Martino, Alba; Guerra, Carmen

    2016-06-01

    The Noonan syndrome (NS) is an autosomal dominant genetic disorder characterized by short stature, craniofacial dysmorphism, and congenital heart defects. A significant proportion of NS patients may also develop myeloproliferative disorders (MPDs), including juvenile myelomonocytic leukaemia (JMML). Surprisingly, scarce information is available in relation to other tumour types in these patients. We have previously developed and characterized a knock-in mouse model that carries one of the most frequent KRAS-NS-related mutations, the K-Ras(V14I) substitution, which recapitulates most of the alterations described in NS patients, including MPDs. The K-Ras(V14I) mutation is a mild activating K-Ras protein; thus, we have used this model to study tumour susceptibility in comparison with mice expressing the classical K-Ras(G12V) oncogene. Interestingly, our studies have shown that these mice display a generalized tumour predisposition and not just MPDs. In fact, we have observed that the K-Ras(V14I) mutation is capable of cooperating with the p16Ink4a/p19Arf and Trp53 tumour suppressors, as well as with other risk factors such as pancreatitis, thereby leading to a higher cancer incidence. In conclusion, our results illustrate that the K-Ras(V14I) activating protein is able to induce cancer, although at a much lower level than the classical K-Ras(G12V) oncogene, and that it can be significantly modulated by both genetic and non-genetic events. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

  12. Transactivation domain of p53 regulates DNA repair and integrity in human iPS cells.

    Science.gov (United States)

    Kannappan, Ramaswamy; Mattapally, Saidulu; Wagle, Pooja A; Zhang, Jianyi

    2018-05-18

    The role of p53 transactivation domain (p53-TAD), a multifunctional and dynamic domain, on DNA repair and retaining DNA integrity in human iPS cells has never been studied. p53-TAD was knocked out in iPS cells using CRISPR/Cas9 and was confirmed by DNA sequencing. p53-TAD KO cells were characterized by: accelerated proliferation, decreased population doubling time, and unaltered Bcl2, BBC3, IGF1R, Bax and altered Mdm2, p21, and PIDD transcripts expression. In p53-TAD KO cells p53 regulated DNA repair proteins XPA, DNA polH and DDB2 expression were found to be reduced compared to p53-WT cells. Exposure to low dose of doxorubicin (Doxo) induced similar DNA damage and DNA damage response (DDR) measured by RAD50 and MRE11 expression, Checkpoint kinase 2 activation and γH2A.X recruitment at DNA strand breaks in both the cell groups indicating silencing p53-TAD do not affect DDR mechanism upstream of p53. Following removal of Doxo p53-WT hiPS cells underwent DNA repair, corrected their damaged DNA and restored DNA integrity. Conversely, p53-TAD KO hiPS cells did not undergo complete DNA repair and failed to restore DNA integrity. More importantly continuous culture of p53-TAD KO hiPS cells underwent G2/M cell cycle arrest and expressed cellular senescent marker p16 INK4a . Our data clearly shows that silencing transactivation domain of p53 did not affect DDR but affected the DNA repair process implying the crucial role of p53 transactivation domain in maintaining DNA integrity. Therefore, activating p53-TAD domain using small molecules may promote DNA repair and integrity of cells and prevent senescence.

  13. MK3 modulation affects BMI1-dependent and independent cell cycle check-points.

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    Peggy Prickaerts

    Full Text Available Although the MK3 gene was originally found deleted in some cancers, it is highly expressed in others. The relevance of MK3 for oncogenesis is currently not clear. We recently reported that MK3 controls ERK activity via a negative feedback mechanism. This prompted us to investigate a potential role for MK3 in cell proliferation. We here show that overexpression of MK3 induces a proliferative arrest in normal diploid human fibroblasts, characterized by enhanced expression of replication stress- and senescence-associated markers. Surprisingly, MK3 depletion evokes similar senescence characteristics in the fibroblast model. We previously identified MK3 as a binding partner of Polycomb Repressive Complex 1 (PRC1 proteins. In the current study we show that MK3 overexpression results in reduced cellular EZH2 levels and concomitant loss of epigenetic H3K27me3-marking and PRC1/chromatin-occupation at the CDKN2A/INK4A locus. In agreement with this, the PRC1 oncoprotein BMI1, but not the PCR2 protein EZH2, bypasses MK3-induced senescence in fibroblasts and suppresses P16INK4A expression. In contrast, BMI1 does not rescue the MK3 loss-of-function phenotype, suggesting the involvement of multiple different checkpoints in gain and loss of MK3 function. Notably, MK3 ablation enhances proliferation in two different cancer cells. Finally, the fibroblast model was used to evaluate the effect of potential tumorigenic MK3 driver-mutations on cell proliferation and M/SAPK signaling imbalance. Taken together, our findings support a role for MK3 in control of proliferation and replicative life-span, in part through concerted action with BMI1, and suggest that the effect of MK3 modulation or mutation on M/SAPK signaling and, ultimately, proliferation, is cell context-dependent.

  14. Re: Role of Telomeres and Telomerase in Cancer

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    Shay JW

    2016-03-01

    Full Text Available The most important difference between cancer and normall cells is the ability to continuous proliferation. This activation works due to telomeres and telomerase enzyme. Fifty years ago, Leonard Hayflick discovered that cultured normal humans cells have a limited capacity to divide. Today, this withdrawal from the cell cycle after a certain number of cellular divisions (replicative senescence is known to be triggered as a result of shortened telomeres. Studies on telomeres and telomerase have begun to provide additional information about aging and cancer development and have created new opportunities in the field of regenerative medicine for telomeropathies. Progressive telomere shortening from cell division (replicative aging provides a barrier for tumor progression. Continuous cell growth in malignancy correlates with the reactivation of telomerase. Telomerase is a cellular reverse transcriptase that adds new deoxyribonucleic acid (DNA onto the telomeres that are located at the ends of chromosomes. Telomeres consist of many kilobases of TTAGGG nucleotide repeats. The telomeric nucleotide repeats shorten with each cell division due to replication problems (DNA repair and oxidative damage. Quiescent/senescent state of the cell bypass can be accomplished by abrogating cell cycle checkpoint genes (such as TP53, p16INK4a, pRb. Telomerase is detected in approximately 90% of all malignant tumors. This telomerase activation has emerged as a target for cancer treatment. Telomerase therapeutics are classified as gene therapy (hTERT-telomerase catalytic protein component, hTR-telomerase functional, immunotherapy (Imetalstat-telomerase template antagonist, and small molecule inhibitors. In the near future, more specific researches on telomers and telomerase will contribute to aging/immortality studies (as stem cells and to discover new biomarkers for malignant tissue or anticancer therapeutics.

  15. Combined Inhibition of CDK4/6 and PI3K/AKT/mTOR Pathways Induces a Synergistic Anti-Tumor Effect in Malignant Pleural Mesothelioma Cells

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    Mara A. Bonelli

    2017-08-01

    Full Text Available Malignant pleural mesothelioma (MPM is a progressive malignancy associated to the exposure of asbestos fibers. The most frequently inactivated tumor suppressor gene in MPM is CDKN2A/ARF, encoding for the cell cycle inhibitors p16INK4a and p14ARF, deleted in about 70% of MPM cases. Considering the high frequency of alterations of this gene, we tested in MPM cells the efficacy of palbociclib (PD-0332991, a highly selective inhibitor of cyclin-dependent kinase (CDK 4/6. The analyses were performed on a panel of MPM cell lines and on two primary culture cells from pleural effusion of patients with MPM. All the MPM cell lines, as well as the primary cultures, were sensitive to palbociclib with a significant blockade in G0/G1 phase of the cell cycle and with the acquisition of a senescent phenotype. Palbociclib reduced the phosphorylation levels of CDK6 and Rb, the expression of myc with a concomitant increased phosphorylation of AKT. Based on these results, we tested the efficacy of the combination of palbociclib with the PI3K inhibitors NVP-BEZ235 or NVP-BYL719. After palbociclib treatment, the sequential association with PI3K inhibitors synergistically hampered cell proliferation and strongly increased the percentage of senescent cells. In addition, AKT activation was repressed while p53 and p21 were up-regulated. Interestingly, two cycles of sequential drug administration produced irreversible growth arrest and senescent phenotype that were maintained even after drug withdrawal. These findings suggest that the sequential association of palbociclib with PI3K inhibitors may represent a valuable therapeutic option for the treatment of MPM.

  16. Stratification and Prognostic Relevance of Jass’s Molecular Classification of Colorectal Cancer

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    Zlobec, Inti [Institute of Pathology, University of Bern, Bern (Switzerland); Institute for Pathology, University Hospital Basel, Basel (Switzerland); Bihl, Michel P.; Foerster, Anja; Rufle, Alex; Terracciano, Luigi [Institute for Pathology, University Hospital Basel, Basel (Switzerland); Lugli, Alessandro, E-mail: inti.zlobec@pathology.unibe.ch [Institute of Pathology, University of Bern, Bern (Switzerland); Institute for Pathology, University Hospital Basel, Basel (Switzerland)

    2012-02-27

    Background: The current proposed model of colorectal tumorigenesis is based primarily on CpG island methylator phenotype (CIMP), microsatellite instability (MSI), KRAS, BRAF, and methylation status of 0-6-Methylguanine DNA Methyltransferase (MGMT) and classifies tumors into five subgroups. The aim of this study is to validate this molecular classification and test its prognostic relevance. Methods: Three hundred two patients were included in this study. Molecular analysis was performed for five CIMP-related promoters (CRABP1, MLH1, p16INK4a, CACNA1G, NEUROG1), MGMT, MSI, KRAS, and BRAF. Methylation in at least 4 promoters or in one to three promoters was considered CIMP-high and CIMP-low (CIMP-H/L), respectively. Results: CIMP-H, CIMP-L, and CIMP-negative were found in 7.1, 43, and 49.9% cases, respectively. One hundred twenty-three tumors (41%) could not be classified into any one of the proposed molecular subgroups, including 107 CIMP-L, 14 CIMP-H, and two CIMP-negative cases. The 10 year survival rate for CIMP-high patients [22.6% (95%CI: 7–43)] was significantly lower than for CIMP-L or CIMP-negative (p = 0.0295). Only the combined analysis of BRAF and CIMP (negative versus L/H) led to distinct prognostic subgroups. Conclusion: Although CIMP status has an effect on outcome, our results underline the need for standardized definitions of low- and high-level CIMP, which clearly hinders an effective prognostic and molecular classification of colorectal cancer.

  17. Stratification and prognostic relevance of Jass’s molecular classification of colorectal cancer

    Directory of Open Access Journals (Sweden)

    Inti eZlobec

    2012-02-01

    Full Text Available Background: The current proposed model of colorectal tumorigenesis is based primarily on CpG island methylator phenotype (CIMP, microsatellite instability (MSI, KRAS, BRAF, and methylation status of 0-6-Methylguanine DNA Methyltransferase (MGMT and classifies tumors into 5 subgroups. The aim of this study is to validate this molecular classification and test its prognostic relevance. Methods: 302 patients were included in this study. Molecular analysis was performed for 5 CIMP-related promoters (CRABP1, MLH1, p16INK4a, CACNA1G, NEUROG1, MGMT, MSI, KRAS and BRAF. Tumors were CIMP-high or CIMP-low if ≥4 and 1-3 promoters were methylated, respectively. Results: CIMP-high, CIMP-low and CIMP–negative were found in 7.1%, 43% and 49.9% cases, respectively. 123 tumors (41% could not be classified into any one of the proposed molecular subgroups, including 107 CIMP-low, 14 CIMP-high and 2 CIMP-negative cases. The 10-year survival rate for CIMP-high patients (22.6% (95%CI: 7-43 was significantly lower than for CIMP-low or CIMP-negative (p=0.0295. Only the combined analysis of BRAF and CIMP (negative versus low/high led to distinct prognostic subgroups. Conclusion: Although CIMP status has an effect on outcome, our results underline the need for standardized definitions of low- and high-level CIMP, which clearly hinders an effective prognostic and molecular classification of colorectal cancer.

  18. Association between the CpG island methylator phenotype and its prognostic significance in primary pulmonary adenocarcinoma.

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    Koh, Young Wha; Chun, Sung-Min; Park, Young-Soo; Song, Joon Seon; Lee, Geon Kook; Khang, Shin Kwang; Jang, Se Jin

    2016-08-01

    Aberrant methylation of promoter CpG islands is one of the most important inactivation mechanisms for tumor suppressor and tumor-related genes. Previous studies using genome-wide DNA methylation microarray analysis have suggested the existence of a CpG island methylator phenotype (CIMP) in lung adenocarcinomas. Although the biological behavior of these tumors varies according to tumor stage, no large-scale study has examined the CIMP in lung adenocarcinoma patients according to tumor stage. Furthermore, there have been no reported results regarding the clinical significance of each of the six CIMP markers. To examine the CIMP in patients with pulmonary adenocarcinoma after a surgical resection, we performed methylation analysis of six genes (CCNA1, ACAN, GFRA1, EDARADD, MGC45800, and p16 (INK4A)) in 230 pulmonary adenocarcinoma cases using the SEQUENOM MassARRAY platform. Fifty-four patients (28 %, 54/191) were in the CIMP-high (CIMP-H) group associated with high nodal stage (P = 0.007), the presence of micropapillary or solid histology (P = 0.003), and the absence of an epidermal growth factor receptor (EGFR) mutation (P = 0.002). By multivariate analysis, CIMP was an independent prognostic marker for overall survival (OS) and disease-specific survival (P = 0.03 and P = 0.43, respectively). In the stage I subgroups alone, CIMP-H patients had lower OS rates than the CIMP-low (CIMP-L) group (P = 0.041). Of the six CIMP markers, ACAN alone was significantly associated with patient survival. CIMP predicted the risk of progression independently of clinicopathological variables and enables the stratification of pulmonary adenocarcinoma patients, particularly among stage I cases.

  19. Exercise Prevents Diet-Induced Cellular Senescence in Adipose Tissue.

    Science.gov (United States)

    Schafer, Marissa J; White, Thomas A; Evans, Glenda; Tonne, Jason M; Verzosa, Grace C; Stout, Michael B; Mazula, Daniel L; Palmer, Allyson K; Baker, Darren J; Jensen, Michael D; Torbenson, Michael S; Miller, Jordan D; Ikeda, Yasuhiro; Tchkonia, Tamara; van Deursen, Jan M; Kirkland, James L; LeBrasseur, Nathan K

    2016-06-01

    Considerable evidence implicates cellular senescence in the biology of aging and chronic disease. Diet and exercise are determinants of healthy aging; however, the extent to which they affect the behavior and accretion of senescent cells within distinct tissues is not clear. Here we tested the hypothesis that exercise prevents premature senescent cell accumulation and systemic metabolic dysfunction induced by a fast-food diet (FFD). Using transgenic mice that express EGFP in response to activation of the senescence-associated p16(INK4a) promoter, we demonstrate that FFD consumption causes deleterious changes in body weight and composition as well as in measures of physical, cardiac, and metabolic health. The harmful effects of the FFD were associated with dramatic increases in several markers of senescence, including p16, EGFP, senescence-associated β-galactosidase, and the senescence-associated secretory phenotype (SASP) specifically in visceral adipose tissue. We show that exercise prevents the accumulation of senescent cells and the expression of the SASP while nullifying the damaging effects of the FFD on parameters of health. We also demonstrate that exercise initiated after long-term FFD feeding reduces senescent phenotype markers in visceral adipose tissue while attenuating physical impairments, suggesting that exercise may provide restorative benefit by mitigating accrued senescent burden. These findings highlight a novel mechanism by which exercise mediates its beneficial effects and reinforces the effect of modifiable lifestyle choices on health span. © 2016 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  20. The Bmi-1 helix–turn and ring finger domains are required for Bmi-1 antagonism of (–) epigallocatechin-3-gallate suppression of skin cancer cell survival

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    Balasubramanian, Sivaprakasam; Scharadin, Tiffany M.; Han, Bingshe; Xu, Wen; Eckert, Richard L.

    2016-01-01

    The Bmi-1 Polycomb group (PcG) protein is an important epigenetic regulator of chromatin status. Elevated Bmi-1 expression is observed in skin cancer and contributes to cancer cell survival. (–) Epigallocatechin-3-gallate (EGCG), an important green tea-derived cancer prevention agent, reduces Bmi-1 level resulting in reduced skin cancer cell survival. This is associated with increased p21Cip1 and p27Kip1 expression, reduced cyclin, and cyclin dependent kinase expression, and increased cleavage of apoptotic markers. These EGCG-dependent changes are attenuated by vector-mediated maintenance of Bmi-1 expression. In the present study, we identify Bmi-1 functional domains that are required for this response. Bmi-1 expression reverses the EGCG-dependent reduction in SCC-13 cell survival, but Bmi-1 mutants lacking the helix–turn–helix–turn–helix–turn (Bmi-1ΔHT) or ring finger (Bmi-1ΔRF) domains do not reverse the EGCG impact. The reduction in Ring1B ubiquitin ligase activity, observed in the presence of mutant Bmi-1, is associated with reduced ability of these mutants to interact with and activate Ring1B ubiquitin ligase, the major ligase responsible for the ubiquitination of histone H2A during chromatin condensation. This results in less chromatin condensation leading to increased tumor suppressor gene expression and reduced cell survival; thereby making the cells more susceptible to the anti-survival action of EGCG. We further show that these mutants act in a dominant-negative manner to inhibit the action of endogenous Bmi-1. Our results suggest that the HT and RF domains are required for Bmi-1 ability to maintain skin cancer cell survival in response to cancer preventive agents. PMID:25843776

  1. Laser microdissection and capture of pure cardiomyocytes and fibroblasts from infarcted heart regions: perceived hyperoxia induces p21 in peri-infarct myocytes.

    Science.gov (United States)

    Kuhn, Donald E; Roy, Sashwati; Radtke, Jared; Khanna, Savita; Sen, Chandan K

    2007-03-01

    Myocardial infarction caused by ischemia-reperfusion in the coronary vasculature is a focal event characterized by an infarct-core, bordering peri-infarct zone and remote noninfarct zone. Recently, we have reported the first technique, based on laser microdissection pressure catapulting (LMPC), enabling the dissection of infarction-induced biological responses in multicellular regions of the heart. Molecular mechanisms in play at the peri-infarct zone are central to myocardial healing. At the infarct site, myocytes are more sensitive to insult than robust fibroblasts. Understanding of cell-specific responses in the said zones is therefore critical. In this work, we describe the first technique to collect the myocardial tissue with a single-cell resolution. The infarcted myocardium was identified by using a truncated hematoxylin-eosin stain. Cell elements from the infarct, peri-infarct, and noninfarct zones were collected in a chaotropic RNA lysis solution with micron-level surgical precision. Isolated RNA was analyzed for quality by employing microfluidics technology and reverse transcribed to generate cDNA. Purity of the collected specimen was established by real-time PCR analyses of cell-specific genes. Previously, we have reported that the oxygen-sensitive induction of p21/Cip1/Waf1/Sdi1 in cardiac fibroblasts in the peri-infarct zone plays a vital role in myocardial remodeling. Using the novel LMPC technique developed herein, we confirmed that finding and report for the first time that the induction of p21 in the peri-infarct zone is not limited to fibroblasts but is also evident in myocytes. This work presents the first account of an analytical technique that applies the LMPC technology to study myocardial remodeling with a cell-type specific resolution.

  2. Histone demethylase JMJD2B is required for tumor cell proliferation and survival and is overexpressed in gastric cancer

    International Nuclear Information System (INIS)

    Li, Wenjuan; Zhao, Li; Zang, Wen; Liu, Zhifang; Chen, Long; Liu, Tiantian; Xu, Dawei; Jia, Jihui

    2011-01-01

    Highlights: ► JMJD2B is required for cell proliferation and in vivo tumorigenesis. ► JMJD2B depletion induces apoptosis and/or cell cycle arrest. ► JMJD2B depletion activates DNA damage response and enhances p53 stabilization. ► JMJD2B is overexpressed in human primary gastric cancer. -- Abstract: Epigenetic alterations such as aberrant expression of histone-modifying enzymes have been implicated in tumorigenesis. Jumonji domain containing 2B (JMJD2B) is a newly identified histone demethylase that regulates chromatin structure or gene expression by removing methyl residues from trimethylated lysine 9 on histone H3. Recent observations have shown oncogenic activity of JMJD2B. We explored the functional role of JMJD2B in cancer cell proliferation, survival and tumorigenesis, and determined its expression profile in gastric cancer. Knocking down JMJD2B expression by small interfering RNA (siRNA) in gastric and other cancer cells inhibited cell proliferation and/or induced apoptosis and elevated the expression of p53 and p21 CIP1 proteins. The enhanced p53 expression resulted from activation of the DNA damage response pathway. JMJD2B knockdown markedly suppressed xenograft tumor growth in vivo in mice. Moreover, JMJD2B expression was increased in primary gastric-cancer tissues of humans. Thus, JMJD2B is required for sustained proliferation and survival of tumor cells in vitro and in vivo, and its aberrant expression may contribute to the pathogenesis of gastric cancer.

  3. Orphan nuclear receptor TLX recruits histone deacetylases to repress transcription and regulate neural stem cell proliferation.

    Science.gov (United States)

    Sun, Guoqiang; Yu, Ruth T; Evans, Ronald M; Shi, Yanhong

    2007-09-25

    TLX is a transcription factor that is essential for neural stem cell proliferation and self-renewal. However, the molecular mechanism of TLX-mediated neural stem cell proliferation and self-renewal is largely unknown. We show here that TLX recruits histone deacetylases (HDACs) to its downstream target genes to repress their transcription, which in turn regulates neural stem cell proliferation. TLX interacts with HDAC3 and HDAC5 in neural stem cells. The HDAC5-interaction domain was mapped to TLX residues 359-385, which contains a conserved nuclear receptor-coregulator interaction motif IXXLL. Both HDAC3 and HDAC5 have been shown to be recruited to the promoters of TLX target genes along with TLX in neural stem cells. Recruitment of HDACs led to transcriptional repression of TLX target genes, the cyclin-dependent kinase inhibitor, p21(CIP1/WAF1)(p21), and the tumor suppressor gene, pten. Either inhibition of HDAC activity or knockdown of HDAC expression led to marked induction of p21 and pten gene expression and dramatically reduced neural stem cell proliferation, suggesting that the TLX-interacting HDACs play an important role in neural stem cell proliferation. Moreover, expression of a TLX peptide containing the minimal HDAC5 interaction domain disrupted the TLX-HDAC5 interaction. Disruption of this interaction led to significant induction of p21 and pten gene expression and to dramatic inhibition of neural stem cell proliferation. Taken together, these findings demonstrate a mechanism for neural stem cell proliferation through transcriptional repression of p21 and pten gene expression by TLX-HDAC interactions.

  4. N-acetylaspartate (NAA) induces neuronal differentiation of SH-SY5Y neuroblastoma cell line and sensitizes it to chemotherapeutic agents.

    Science.gov (United States)

    Mazzoccoli, Carmela; Ruggieri, Vitalba; Tataranni, Tiziana; Agriesti, Francesca; Laurenzana, Ilaria; Fratello, Angelo; Capitanio, Nazzareno; Piccoli, Claudia

    2016-05-03

    Neuroblastoma is the most commonly extra-cranial solid tumor of childhood frequently diagnosed. The nervous system-specific metabolite N-acetylaspartate (NAA) is synthesized from aspartate and acetyl-CoA in neurons, it is among the most abundant metabolites present in the central nervous system (CNS) and appears to be involved in many CNS disorders. The functional significance of the high NAA concentration in the brain remains uncertain, but it confers to NAA a unique clinical significance exploited in magnetic resonance spectroscopy. In the current study, we show that treatment of SH-SY5Y neuroblastoma-derived cell line with sub-cytotoxic physiological concentrations of NAA inhibits cell growth. This effect is partly due to enhanced apoptosis, shown by decrease of the anti-apoptotic factors survivin and Bcl-xL, and partly to arrest of the cell-cycle progression, linked to enhanced expression of the cyclin-inhibitors p53, p21Cip1/Waf1 and p27Kip1. Moreover, NAA-treated SH-SY5Y cells exhibited morphological changes accompanied with increase of the neurogenic markers TH and MAP2 and down-regulation of the pluripotency markers OCT4 and CXCR4/CD184. Finally, NAA-pre-treated SH-SY5Y cells resulted more sensitive to the cytotoxic effect of the chemotherapeutic drugs Cisplatin and 5-fluorouracil.To our knowledge, this is the first study demonstrating the neuronal differentiating effects of NAA in neuroblastoma cells. NAA may be a potential preconditioning or adjuvant compound in chemotherapeutic treatment.

  5. Cyclin-dependent kinases regulate apoptosis of intestinal epithelial cells

    Science.gov (United States)

    Bhattacharya, Sujoy; Ray, Ramesh M.; Johnson, Leonard R.

    2014-01-01

    Homeostasis of the gastrointestinal epithelium is dependent upon a balance between cell proliferation and apoptosis. Cyclin-dependent kinases (Cdks) are well known for their role in cell proliferation. Previous studies from our group have shown that polyamine-depletion of intestinal epithelial cells (IEC-6) decreases cyclin-dependent kinase 2 (Cdk2) activity, increases p53 and p21Cip1 protein levels, induces G1 arrest, and protects cells from camptothecin (CPT)-induced apoptosis. Although emerging evidence suggests that members of the Cdk family are involved in the regulation of apoptosis, their roles directing apoptosis of IEC-6 cells are not known. In this study, we report that inhibition of Cdk1, 2, and 9 (with the broad range Cdk inhibitor, AZD5438) in proliferating IEC-6 cells triggered DNA damage, activated p53 signaling, inhibited proliferation, and induced apoptosis. By contrast, inhibition of Cdk2 (with NU6140) increased p53 protein and activity, inhibited proliferation, but had no effect on apoptosis. Notably, AZD5438 sensitized, whereas, NU6140 rescued proliferating IEC-6 cells from CPT-induced apoptosis. However, in colon carcinoma (Caco2) cells with mutant p53, treatment with either AZD5438 or NU6140 blocked proliferation, albeit more robustly with AZD5438. Both Cdk inhibitors induced apoptosis in Caco2 cells in a p53-independent manner. In serum starved quiescent IEC-6 cells, both AZD5438 and NU6140 decreased TNF- /CPT-induced activation of p53 and, consequently, rescued cells from apoptosis, indicating that sustained Cdk activity is required for apoptosis of quiescent cells. Furthermore, AZD5438 partially reversed the protective effect of polyamine depletion whereas NU6140 had no effect. Together, these results demonstrate that Cdks possess opposing roles in the control of apoptosis in quiescent and proliferating cells. In addition, Cdk inhibitors uncouple proliferation from apoptosis in a p53-dependent manner. PMID:24242917

  6. Smad7 induces tumorigenicity by blocking TGF-beta-induced growth inhibition and apoptosis.

    Science.gov (United States)

    Halder, Sunil K; Beauchamp, R Daniel; Datta, Pran K

    2005-07-01

    Smad proteins play a key role in the intracellular signaling of the transforming growth factor beta (TGF-beta) superfamily of extracellular polypeptides that initiate signaling to regulate a wide variety of biological processes. The inhibitory Smad, Smad7, has been shown to function as intracellular antagonists of TGF-beta family signaling and is upregulated in several cancers. To determine the effect of Smad7-mediated blockade of TGF-beta signaling, we have stably expressed Smad7 in a TGF-beta-sensitive, well-differentiated, and non-tumorigenic cell line, FET, that was derived from human colon adenocarcinoma. Smad7 inhibits TGF-beta-induced transcriptional responses by blocking complex formation between Smad 2/3 and Smad4. While Smad7 has no effect on TGF-beta-induced activation of p38 MAPK and ERK, it blocks the phosphorylation of Akt by TGF-beta and enhances TGF-beta-induced phosphorylation of c-Jun. FET cells expressing Smad7 show anchorage-independent growth and enhance tumorigenicity in athymic nude mice. Smad7 blocks TGF-beta-induced growth inhibition by preventing TGF-beta-induced G1 arrest. Smad7 inhibits TGF-beta-mediated downregulation of c-Myc, CDK4, and Cyclin D1, and suppresses the expression of p21(Cip1). As a result, Smad7 inhibits TGF-beta-mediated downregulation of Rb phosphorylation. Furthermore, Smad7 inhibits the apoptosis of these cells. Together, Smad7 may increase the tumorigenicity of FET cells by blocking TGF-beta-induced growth inhibition and by inhibiting apoptosis. Thus, this study provides a mechanism by which a portion of human colorectal tumors may become refractory to tumor-suppressive actions of TGF-beta that might result in increased tumorigenicity.

  7. Experimental study on inhibitory effects of histone deacetylase inhibitor MS-275 and TSA on bladder cancer cells.

    Science.gov (United States)

    Qu, Wei; Kang, Yin-Dong; Zhou, Mei-Sheng; Fu, Li-Li; Hua, Zhen-Hao; Wang, Li-Ming

    2010-01-01

    To investigate the inhibitory effect of histone deacetylase (HDAC) inhibitors (MS-275 and TSA) on T24 human bladder cancer cells in vitro, and explore the possible mechanism. The MTT assay was employed to evaluate the inhibitory effect of MS-275 and TSA on T24 cell growth. FCM was used to analyze the variation of T24 cell cycle distribution and the apoptotic ratio after T24 cells were treated with MS-275 and TSA. Histone acetylation level was detected by Western blot. mRNA expression of p21 WAF1/CIP1, cyclin A, and cyclin E was measured by FQ-PCR. Dynamic changes of Bcl-2 and bax expression were detected by FCM. MS-275 and TSA inhibited T24 cell growth in a concentration and time-dependent manner. Treatment with 4 μmol/l MS-275 or 0.4 μmol/l TSA blocked cell cycling in the G0/G1 phase and induced a significant increase in cell apoptosis. MS-275 and TSA significantly increased the level of histone acetylation, induced p21CIP1WAF1 mRNA expression, and inhibited cyclin A mRNA expression, though no significant effect was observed on cyclin E. Bcl-2 expression was down-regulated, while bax expression was up-regulated. HDAC inhibitors can block bladder cancer cell cycle in vitro and induce apoptosis. The molecular mechanism may be associated with increased level of histone acetylation, down-regulation of p21WAF1/CIP1 expression, up-regulation of cyclin A expression, and dynamic change of bcl-2 and bax expression. Copyright © 2010 Elsevier Inc. All rights reserved.

  8. Identifying candidate agents for lung adenocarcinoma by walking the human interactome

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    Sun Y

    2016-09-01

    Full Text Available Yajiao Sun,1 Ranran Zhang,2 Zhe Jiang,1 Rongyao Xia,1 Jingwen Zhang,1 Jing Liu,1 Fuhui Chen1 1Department of Respiratory, The Second Affiliated Hospital of Harbin Medical University, 2Department of Respiratory, Harbin First Hospital, Harbin, People’s Republic of China Abstract: Despite recent advances in therapeutic strategies for lung cancer, mortality is still increasing. Therefore, there is an urgent need to identify effective novel drugs. In the present study, we implement drug repositioning for lung adenocarcinoma (LUAD by a bioinformatics method followed by experimental validation. We first identified differentially expressed genes between LUAD tissues and nontumor tissues from RNA sequencing data obtained from The Cancer Genome Atlas database. Then, candidate small molecular drugs were ranked according to the effect of their targets on differentially expressed genes of LUAD by a random walk with restart algorithm in protein–protein interaction networks. Our method identified some potentially novel agents for LUAD besides those that had been previously reported (eg, hesperidin. Finally, we experimentally verified that atracurium, one of the potential agents, could induce A549 cells death in non-small-cell lung cancer-derived A549 cells by an MTT assay, acridine orange and ethidium bromide staining, and electron microscopy. Furthermore, Western blot assays demonstrated that atracurium upregulated the proapoptotic Bad and Bax proteins, downregulated the antiapoptotic p-Bad and Bcl-2 proteins, and enhanced caspase-3 activity. It could also reduce the expression of p53 and p21Cip1/Waf1 in A549 cells. In brief, the candidate agents identified by our approach may provide greater insights into improving the therapeutic status of LUAD. Keywords: lung adenocarcinoma, drug repositioning, bioinformatics, protein–protein interaction network, atracurium

  9. MicroRNA-124 controls the proliferative, migratory, and inflammatory phenotype of pulmonary vascular fibroblasts.

    Science.gov (United States)

    Wang, Daren; Zhang, Hui; Li, Min; Frid, Maria G; Flockton, Amanda R; McKeon, B Alexandre; Yeager, Michael E; Fini, Mehdi A; Morrell, Nicholas W; Pullamsetti, Soni S; Velegala, Sivareddy; Seeger, Werner; McKinsey, Timothy A; Sucharov, Carmen C; Stenmark, Kurt R

    2014-01-03

    Pulmonary hypertensive remodeling is characterized by excessive proliferation, migration, and proinflammatory activation of adventitial fibroblasts. In culture, fibroblasts maintain a similar activated phenotype. The mechanisms responsible for generation/maintenance of this phenotype remain unknown. We hypothesized that aberrant expression of microRNA-124 (miR-124) regulates this activated fibroblast phenotype and sought to determine the signaling pathways through which miR-124 exerts effects. We detected significant decreases in miR-124 expression in fibroblasts isolated from calves and humans with severe pulmonary hypertension. Overexpression of miR-124 by mimic transfection significantly attenuated proliferation, migration, and monocyte chemotactic protein-1 expression of hypertensive fibroblasts, whereas anti-miR-124 treatment of control fibroblasts resulted in their increased proliferation, migration, and monocyte chemotactic protein-1 expression. Furthermore, the alternative splicing factor, polypyrimidine tract-binding protein 1, was shown to be a direct target of miR-124 and to be upregulated both in vivo and in vitro in bovine and human pulmonary hypertensive fibroblasts. The effects of miR-124 on fibroblast proliferation were mediated via direct binding to the 3' untranslated region of polypyrimidine tract-binding protein 1 and subsequent regulation of Notch1/phosphatase and tensin homolog/FOXO3/p21Cip1 and p27Kip1 signaling. We showed that miR-124 directly regulates monocyte chemotactic protein-1 expression in pulmonary hypertension/idiopathic pulmonary arterial hypertension fibroblasts. Furthermore, we demonstrated that miR-124 expression is suppressed by histone deacetylases and that treatment of hypertensive fibroblasts with histone deacetylase inhibitors increased miR-124 expression and decreased proliferation and monocyte chemotactic protein-1 production. Stable decreases in miR-124 expression contribute to an epigenetically reprogrammed, highly

  10. Progression of Human Renal Cell Carcinoma via Inhibition of RhoA-ROCK Axis by PARG1

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    Junichiro Miyazaki

    2017-04-01

    Full Text Available Renal cell carcinoma (RCC is the most lethal urological malignancy with high risk of recurrence; thus, new prognostic biomarkers are needed. In this study, a new RCC antigen, PTPL1 associated RhoGAP1 (PARG1, was identified by using serological identification of recombinant cDNA expression cloning with sera from RCC patients. PARG1 protein was found to be differentially expressed in RCC cells among patients. High PARG1 expression is significantly correlated with various clinicopathological factors relating to cancer cell proliferation and invasion, including G3 percentage (P = .0046, Ki-67 score (p expression is also correlated with high recurrence of N0M0 patients (P = .0084 and poor prognosis in RCC patients (P = .0345. Multivariate analysis has revealed that high PARG1 expression is an independent factor for recurrence (P = .0149 of N0M0 RCC patients. In in vitro studies, depletion of PARG1by siRNA in human RCC cell lines inhibited their proliferation through inducing G1 cell cycle arrest via upregulation of p53 and subsequent p21Cip1/Waf1, which are mediated by increased RhoA-ROCK activities. Similarly, PARG1 depletion cells inhibited invasion ability via increasing RhoA-ROCK activities in the RCC cell lines. Conversely, overexpression of PARG1 on human embryonic kidney cell line HEK293T promotes its cell proliferation and invasion. These results indicate that PARG1 plays crucial roles in progression of human RCC in increasing cell proliferation and invasion ability via inhibition of the RhoA-ROCK axis, and PARG1 is a poor prognostic marker, particularly for high recurrence of N0M0 RCC patients.

  11. Casticin induced apoptotic cell death and altered associated gene expression in human colon cancer colo 205 cells.

    Science.gov (United States)

    Shang, Hung-Sheng; Liu, Jia-You; Lu, Hsu-Feng; Chiang, Han-Sun; Lin, Chia-Hain; Chen, Ann; Lin, Yuh-Feng; Chung, Jing-Gung

    2017-08-01

    Casticin, a polymethoxyflavone, derived from natural plant Fructus Viticis exhibits biological activities including anti-cancer characteristics. The anti-cancer and alter gene expression of casticin on human colon cancer cells and the underlying mechanisms were investigated. Flow cytometric assay was used to measure viable cell, cell cycle and sub-G1 phase, reactive oxygen species (ROS) and Ca 2+ productions, level of mitochondria membrane potential (ΔΨ m ) and caspase activity. Western blotting assay was used to detect expression of protein level associated with cell death. Casticin induced cell morphological changes, decreased cell viability and induced G2/M phase arrest in colo 205 cells. Casticin increased ROS production but decreased the levels of ΔΨ m , and Ca 2+ , increased caspase-3, -8, and -9 activities. The cDNA microarray indicated that some of the cell cycle associated genes were down-regulated such as cyclin-dependent kinase inhibitor 1A (CDKN1A) (p21, Cip1) and p21 protein (Cdc42/Rac)-activated kinase 3 (PAK3). TNF receptor-associated protein 1 (TRAP1), CREB1 (cAMP responsive element binding protein 1) and cyclin-dependent kinase inhibitor 1B (CDKN1B) (p27, Kip1) genes were increased but matrix metallopeptidase 2 (MMP-2), toll-like receptor 4 (TLR4), PRKAR2B (protein kinase, cAMP-dependent, regulatory, type II, bet), and CaMK4 (calcium/calmodulin-dependent protein kinase IV) genes were inhibited. Results suggest that casticin induced cell apoptosis via the activation of the caspase- and/or mitochondria-dependent signaling cascade, the accumulation of ROS and altered associated gene expressions in colo 205 human colon cancer cells. © 2016 Wiley Periodicals, Inc.

  12. Piperlongumine inhibits LMP1/MYC-dependent mouse B-lymphoma cells

    International Nuclear Information System (INIS)

    Han, Seong-Su; Tompkins, Van S.; Son, Dong-Ju; Kamberos, Natalie L.; Stunz, Laura L.; Halwani, Ahmad; Bishop, Gail A.; Janz, Siegfried

    2013-01-01

    Highlights: •Mouse model of human Burkitt lymphoma revealed cancer inhibition by PL. •Treatment with PL led to apoptosis of malignant but not normal B cells. •PL inhibited LMP1–NF-κB–Myc-dependent target genes including p21-encoding Cdkn1a. •PL holds promise for new interventions approaches to hematologic malignancies. -- Abstract: Piperlongumine (PL), isolated from the fruit of Long pepper, Piper longum, is a cancer-inhibiting compound that selectively kills tumor cells while sparing their normal counterparts. Here we evaluated the efficacy with which PL suppresses malignant B cells derived from a newly developed, double-transgenic mouse model of human endemic Burkitt lymphoma (BL), designated mCD40-LMP1/iMyc Eμ . PL inhibited tumor cell proliferation in a concentration-dependent manner and induced apoptosis of neoplastic but not normal B cells. Treatment with PL resulted in downregulation of EBV-encoded LMP1, cellular Myc, constitutive NF-κB activity, and a host of LMP1-Myc-NF-κB-regulated target genes including Aurka, Bcat1, Bub1b, Ccnb1, Chek1, Fancd2, Tfrc and Xrcc6. Of note, p21 Cip1 -encoding Cdkn1a was suppressed independent of changes in Trp53 mRNA levels and p53 DNA-binding activity. Considering the central role of the LMP1–NF-κB–Myc axis in B-lineage neoplasia, these findings further our understanding of the mechanisms by which PL inhibits B-lymphoma and provide a preclinical rationale for the inclusion of PL in new interventions in blood cancers

  13. Effect of histone deacetylase inhibitors trichostatin A and valproic acid on hair cell regeneration in zebrafish lateral line neuromasts

    Science.gov (United States)

    He, Yingzi; Cai, Chengfu; Tang, Dongmei; Sun, Shan; Li, Huawei

    2014-01-01

    In humans, auditory hair cells are not replaced when injured. Thus, cochlear hair cell loss causes progressive and permanent hearing loss. Conversely, non-mammalian vertebrates are capable of regenerating lost sensory hair cells. The zebrafish lateral line has numerous qualities that make it well-suited for studying hair cell development and regeneration. Histone deacetylase (HDAC) activity has been shown to have an important role in regenerative processes in vertebrates, but its function in hair cell regeneration in vivo is not fully understood. Here, we have examined the role of HDAC activity in hair cell regeneration in the zebrafish lateral line. We eliminated lateral line hair cells of 5-day post-fertilization larvae using neomycin and then treated the larvae with HDAC inhibitors. To assess hair cell regeneration, we used 5-bromo-2-deoxyuridine (BrdU) incorporation in zebrafish larvae to label mitotic cells after hair cell loss. We found that pharmacological inhibition of HDACs using trichostatin A (TSA) or valproic acid (VPA) increased histone acetylation in the regenerated neuromasts following neomycin-induced damage. We also showed that treatment with TSA or VPA decreased the number of supporting cells and regenerated hair cells in response to hair cell damage. Additionally, BrdU immunostaining and western blot analysis showed that TSA or VPA treatment caused a significant decrease in the percentage of S-phase cells and induced p21Cip1 and p27Kip1 expression, both of which are likely to explain the decrease in the amount of newly regenerated hair cells in treated embryos. Finally, we showed that HDAC inhibitors induced no observable cell death in neuromasts as measured by cleaved caspase-3 immunohistochemistry and western blot analysis. Taken together, our results demonstrate that HDAC activity has an important role in the regeneration of hair cells in the lateral line. PMID:25431550

  14. Early colonizing Escherichia coli elicits remodeling of rat colonic epithelium shifting toward a new homeostatic state.

    Science.gov (United States)

    Tomas, Julie; Reygner, Julie; Mayeur, Camille; Ducroc, Robert; Bouet, Stephan; Bridonneau, Chantal; Cavin, Jean-Baptiste; Thomas, Muriel; Langella, Philippe; Cherbuy, Claire

    2015-01-01

    We investigated the effects of early colonizing bacteria on the colonic epithelium. We isolated dominant bacteria, Escherichia coli, Enterococcus faecalis, Lactobacillus intestinalis, Clostridium innocuum and a novel Fusobacterium spp., from the intestinal contents of conventional suckling rats and transferred them in different combinations into germfree (GF) adult rats. Animals were investigated after various times up to 21 days. Proliferative cell markers (Ki67, proliferating cell nuclear antigen, phospho-histone H3, cyclin A) were higher in rats monocolonized with E. coli than in GF at all time points, but not in rats monocolonized with E. faecalis. The mucin content of goblet cells declined shortly after E. coli administration whereas the mucus layer doubled in thickness. Fluorescence in situ hybridization analyses revealed that E. coli resides in this mucus layer. The epithelial mucin content progressively returned to baseline, following an increase in KLF4 and in the cell cycle arrest-related proteins p21(CIP1) and p27(KIP1). Markers of colonic differentiated cells involved in electrolyte (carbonic anhydrase II and slc26A3) and water (aquaglyceroporin3 (aqp3)) transport, and secretory responses to carbachol were modulated after E. coli inoculation suggesting that ion transport dynamics were also affected. The colonic responses to simplified microbiotas differed substantially according to whether or not E. coli was combined with the other four bacteria. Thus, proliferation markers increased substantially when E. coli was in the mix, but very much less when it was absent. This work demonstrates that a pioneer strain of E. coli elicits sequential epithelial remodeling affecting the structure, mucus layer and ionic movements and suggests this can result in a microbiota-compliant state.

  15. Induction of G1 and G2/M cell cycle arrests by the dietary compound 3,3'-diindolylmethane in HT-29 human colon cancer cells

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    Choi Hyun

    2009-05-01

    Full Text Available Abstract Background 3,3'-Diindolylmethane (DIM, an indole derivative produced in the stomach after the consumption of broccoli and other cruciferous vegetables, has been demonstrated to exert anti-cancer effects in both in vivo and in vitro models. We have previously determined that DIM (0 – 30 μmol/L inhibited the growth of HT-29 human colon cancer cells in a concentration-dependent fashion. In this study, we evaluated the effects of DIM on cell cycle progression in HT-29 cells. Methods HT-29 cells were cultured with various concentrations of DIM (0 – 30 μmol/L and the DNA was stained with propidium iodide, followed by flow cytometric analysis. [3H]Thymidine incorporation assays, Western blot analyses, immunoprecipitation and in vitro kinase assays for cyclin-dependent kinase (CDK and cell division cycle (CDC2 were conducted. Results The percentages of cells in the G1 and G2/M phases were dose-dependently increased and the percentages of cells in S phase were reduced within 12 h in DIM-treated cells. DIM also reduced DNA synthesis in a dose-dependent fashion. DIM markedly reduced CDK2 activity and the levels of phosphorylated retinoblastoma proteins (Rb and E2F-1, and also increased the levels of hypophosphorylated Rb. DIM reduced the protein levels of cyclin A, D1, and CDK4. DIM also increased the protein levels of CDK inhibitors, p21CIP1/WAF1 and p27KIPI. In addition, DIM reduced the activity of CDC2 and the levels of CDC25C phosphatase and cyclin B1. Conclusion Here, we have demonstrated that DIM induces G1 and G2/M phase cell cycle arrest in HT-29 cells, and this effect may be mediated by reduced CDK activity.

  16. Induction of G1 and G2/M cell cycle arrests by the dietary compound 3,3'-diindolylmethane in HT-29 human colon cancer cells.

    Science.gov (United States)

    Choi, Hyun Ju; Lim, Do Young; Park, Jung Han Yoon

    2009-05-29

    3,3'-Diindolylmethane (DIM), an indole derivative produced in the stomach after the consumption of broccoli and other cruciferous vegetables, has been demonstrated to exert anti-cancer effects in both in vivo and in vitro models. We have previously determined that DIM (0 - 30 micromol/L) inhibited the growth of HT-29 human colon cancer cells in a concentration-dependent fashion. In this study, we evaluated the effects of DIM on cell cycle progression in HT-29 cells. HT-29 cells were cultured with various concentrations of DIM (0 - 30 micromol/L) and the DNA was stained with propidium iodide, followed by flow cytometric analysis. [3H]Thymidine incorporation assays, Western blot analyses, immunoprecipitation and in vitro kinase assays for cyclin-dependent kinase (CDK) and cell division cycle (CDC)2 were conducted. The percentages of cells in the G1 and G2/M phases were dose-dependently increased and the percentages of cells in S phase were reduced within 12 h in DIM-treated cells. DIM also reduced DNA synthesis in a dose-dependent fashion. DIM markedly reduced CDK2 activity and the levels of phosphorylated retinoblastoma proteins (Rb) and E2F-1, and also increased the levels of hypophosphorylated Rb. DIM reduced the protein levels of cyclin A, D1, and CDK4. DIM also increased the protein levels of CDK inhibitors, p21CIP1/WAF1 and p27KIPI. In addition, DIM reduced the activity of CDC2 and the levels of CDC25C phosphatase and cyclin B1. Here, we have demonstrated that DIM induces G1 and G2/M phase cell cycle arrest in HT-29 cells, and this effect may be mediated by reduced CDK activity.

  17. Effect of histone deacetylase inhibitors trichostatin A and valproic acid on hair cell regeneration in zebrafish lateral line neuromasts

    Directory of Open Access Journals (Sweden)

    Yingzi eHe

    2014-11-01

    Full Text Available In humans, auditory hair cells are not replaced when injured. Thus, cochlear hair cell loss causes progressive and permanent hearing loss. Conversely, nonmammalian vertebrates are capable of regenerating lost sensory hair cells. The zebrafish lateral line has numerous qualities that make it well suited for studying hair cell development and regeneration. Histone deacetylase (HDAC activity has been shown to have an important role in regenerative processes in vertebrates, but its function in hair cell regeneration in vivo is not fully understood. Here, we have examined the role of HDAC activity in hair cell regeneration in the zebrafish lateral line. We eliminated lateral line hair cells of 5-day post-fertilization larvae using neomycin and then treated the larvae with HDAC inhibitors. To assess hair cell regeneration, we used 5-bromo-2-deoxyuridine (BrdU incorporation in zebrafish larvae to label mitotic cells after hair cell loss. We found that pharmacological inhibition of HDACs using trichostatin A (TSA or valproic acid (VPA increased histone acetylation in the regenerated neuromasts following neomycin-induced damage. We also showed that treatment with TSA or VPA decreased the number of supporting cells and regenerated hair cells in response to hair cell damage. Additionally, BrdU immunostaining and western blot analysis showed that TSA or VPA treatment caused a significant decrease in the percentage of S-phase cells and induced p21Cip1 and p27Kip1 expression, both of which are likely to explain the decrease in the amount of newly regenerated hair cells in treated embryos. Finally, we showed that HDAC inhibitors induced no observable cell death in neuromasts as measured by cleaved caspase-3 immunohistochemistry and western blot analysis. Taken together, our results demonstrate that HDAC activity has an important role in the regeneration of hair cells in the lateral line.

  18. ANGPTL3 is a novel biomarker as it activates ERK/MAPK pathway in oral cancer

    International Nuclear Information System (INIS)

    Koyama, Tomoyoshi; Ogawara, Katsunori; Kasamatsu, Atsushi; Okamoto, Atsushi; Kasama, Hiroki; Minakawa, Yasuyuki; Shimada, Ken; Yokoe, Hidetaka; Shiiba, Masashi; Tanzawa, Hideki; Uzawa, Katsuhiro

    2015-01-01

    Angiopoietin-like 3 (ANGPTL3), which is involved in new blood vessel growth and stimulation of mitogen-activated protein kinase (MAPK), is expressed aberrantly in several types of human cancers. However, little is known about the relevance of ANGPTL3 in the behavior of oral squamous cell carcinoma (OSCC). In this study, we evaluated ANGPTL3 mRNA and protein in OSCC-derived cell lines (n = 8) and primary OSCCs (n = 109) and assessed the effect of ANGPTL3 on the biology and function of OSCCs in vitro and in vivo. Significant (P < 0.05) ANGPTL3 upregulation was detected in the cell lines and most primary OSCCs (60%) compared with the normal counterparts. The ANGPTL3 expression level was correlated closely (P < 0.05) with tumoral size. In patients with T3/T4 tumors, the overall survival rate with an ANGPTL3-positive tumor was significantly (P < 0.05) lower than that of ANGPTL3-negative cases. In vitro, cellular growth in ANGPTL3 knockdown cells significantly (P < 0.05) decreased with inactivated extracellular regulated kinase (ERK) and cell-cycle arrest at the G1 phase resulting from upregulation of the cyclin-dependent kinase inhibitors, including p21 Cip1 and p27 Kip1 . We also observed a marked (P < 0.05) reduction in the growth in ANGPTL3 knockdown-cell xenografts with decreased levels of phosphorylated ERK relative to control-cell xenografts. The current data indicated that ANGPTL3 may play a role in OSCCs via MAPK signaling cascades, making it a potentially useful diagnostic/therapeutic target for use in patients with OSCC

  19. A phase I trial of vorinostat and alvocidib in patients with relapsed, refractory, or poor prognosis acute leukemia, or refractory anemia with excess blasts-2.

    Science.gov (United States)

    Holkova, Beata; Supko, Jeffrey G; Ames, Matthew M; Reid, Joel M; Shapiro, Geoffrey I; Perkins, Edward Brent; Ramakrishnan, Viswanathan; Tombes, Mary Beth; Honeycutt, Connie; McGovern, Renee M; Kmieciak, Maciej; Shrader, Ellen; Wellons, Martha D; Sankala, Heidi; Doyle, Austin; Wright, John; Roberts, John D; Grant, Steven

    2013-04-01

    This phase I study was conducted to identify the maximum-tolerated dose (MTD) of alvocidib when combined with vorinostat in patients with relapsed, refractory, or poor prognosis acute leukemia, or refractory anemia with excess blasts-2. Secondary objectives included investigating the pharmacokinetic and pharmacodynamic effects of the combination. Patients received vorinostat (200 mg orally, three times a day, for 14 days) on a 21-day cycle, combined with 2 different alvocidib administration schedules: a 1-hour intravenous infusion, daily × 5; or a 30-minute loading infusion followed by a 4-hour maintenance infusion, weekly × 2. The alvocidib dose was escalated using a standard 3+3 design. Twenty-eight patients were enrolled and treated. The alvocidib MTD was 20 mg/m(2) (30-minute loading infusion) followed by 20 mg/m(2) (4-hour maintenance infusion) on days one and eight, in combination with vorinostat. The most frequently encountered toxicities were cytopenias, fatigue, hyperglycemia, hypokalemia, hypophosphatemia, and QT prolongation. Dose-limiting toxicities (DLT) were cardiac arrhythmia-atrial fibrillation and QT prolongation. No objective responses were achieved although 13 of 26 evaluable patients exhibited stable disease. Alvocidib seemed to alter vorinostat pharmacokinetics, whereas alvocidib pharmacokinetics were unaffected by vorinostat. Ex vivo exposure of leukemia cells to plasma obtained from patients after alvocidib treatment blocked vorinostat-mediated p21(CIP1) induction and downregulated Mcl-1 and p-RNA Pol II for some specimens, although parallel in vivo bone marrow responses were infrequent. Alvocidib combined with vorinostat is well tolerated. Although disease stabilization occurred in some heavily pretreated patients, objective responses were not obtained with these schedules. ©2013 AACR.

  20. Epigenetic regulation of vascular smooth muscle cell proliferation and neointima formation by histone deacetylase inhibition.

    Science.gov (United States)

    Findeisen, Hannes M; Gizard, Florence; Zhao, Yue; Qing, Hua; Heywood, Elizabeth B; Jones, Karrie L; Cohn, Dianne; Bruemmer, Dennis

    2011-04-01

    Proliferation of smooth muscle cells (SMC) in response to vascular injury is central to neointimal vascular remodeling. There is accumulating evidence that histone acetylation constitutes a major epigenetic modification for the transcriptional control of proliferative gene expression; however, the physiological role of histone acetylation for proliferative vascular disease remains elusive. In the present study, we investigated the role of histone deacetylase (HDAC) inhibition in SMC proliferation and neointimal remodeling. We demonstrate that mitogens induce transcription of HDAC 1, 2, and 3 in SMC. Short interfering RNA-mediated knockdown of either HDAC 1, 2, or 3 and pharmacological inhibition of HDAC prevented mitogen-induced SMC proliferation. The mechanisms underlying this reduction of SMC proliferation by HDAC inhibition involve a growth arrest in the G(1) phase of the cell cycle that is due to an inhibition of retinoblastoma protein phosphorylation. HDAC inhibition resulted in a transcriptional and posttranscriptional regulation of the cyclin-dependent kinase inhibitors p21(Cip1) and p27(Kip). Furthermore, HDAC inhibition repressed mitogen-induced cyclin D1 mRNA expression and cyclin D1 promoter activity. As a result of this differential cell cycle-regulatory gene expression by HDAC inhibition, the retinoblastoma protein retains a transcriptional repression of its downstream target genes required for S phase entry. Finally, we provide evidence that these observations are applicable in vivo by demonstrating that HDAC inhibition decreased neointima formation and expression of cyclin D1 in a murine model of vascular injury. These findings identify HDAC as a critical component of a transcriptional cascade regulating SMC proliferation and suggest that HDAC might play a pivotal role in the development of proliferative vascular diseases, including atherosclerosis and in-stent restenosis.

  1. Factors determining sensitivity or resistance of tumor cell lines towards artesunate.

    Science.gov (United States)

    Sertel, Serkan; Eichhorn, Tolga; Sieber, Sebastian; Sauer, Alexandra; Weiss, Johanna; Plinkert, Peter K; Efferth, Thomas

    2010-04-15

    Clinical oncology is still challenged by the development of drug resistance of tumors that result in poor prognosis for patients. There is an urgent necessity to understand the molecular mechanisms of resistance and to develop novel therapy strategies. Artesunate (ART) is an anti-malarial drug, which also exerts profound cytotoxic activity towards cancer cells. We first applied a gene-hunting approach using cluster and COMPARE analyses of microarray-based transcriptome-wide mRNA expression profiles. Among the genes identified by this approach were genes from diverse functional groups such as structural constituents of ribosomes (RPL6, RPL7, RPS12, RPS15A), kinases (CABC1, CCT2, RPL41), transcriptional and translational regulators (SFRS2, TUFM, ZBTB4), signal transducers (FLNA), control of cell growth and proliferation (RPS6), angiogenesis promoting factors (ITGB1), and others (SLC25A19, NCKAP1, BST1, DBH, FZD7, NACA, MTHFD2). Furthermore, we applied a candidate gene approach and tested the role of resistance mechanisms towards established anti-cancer drugs for ART resistance. By using transfected or knockout cell models we found that the tumor suppressor p16(INK4A) and the anti-oxidant protein, catalase, conferred resistance towards ART, while the oncogene HPV-E6 conferred sensitivity towards ART. The tumor suppressor p53 and its downstream protein, p21, as well as the anti-oxidant manganese-dependent superoxide dismutase did not affect cellular response to ART. In conclusion, our pharmacogenomic approach revealed that response of tumor cells towards ART is multi-factorial and is determined by gene expression associated with either ART sensitivity or resistance. At least some of the functional groups of genes (e.g. angiogenesis promoting factors, cell growth and proliferation-associated genes signal transducers and kinases) are also implicated in clinical responsiveness of tumors towards chemotherapy. It merits further investigation, whether ART is responsive in

  2. Vitamins K2, K3 and K5 exert in vivo antitumor effects on hepatocellular carcinoma by regulating the expression of G1 phase-related cell cycle molecules.

    Science.gov (United States)

    Kuriyama, Shigeki; Hitomi, Misuzu; Yoshiji, Hitoshi; Nonomura, Takako; Tsujimoto, Tatsuhiro; Mitoro, Akira; Akahane, Takami; Ogawa, Mutsumi; Nakai, Seiji; Deguchi, Akihiro; Masaki, Tsutomu; Uchida, Naohito

    2005-08-01

    A number of studies have shown that various vitamins K, specifically vitamin K2, possessed antitumor activity on various types of rodent- and human-derived neoplastic cell lines. However, there are only a small number of reports demonstrating in vivo antitumor effects of vitamins K. Furthermore, the mechanism of antitumor effects of vitamins K still remains to be examined. In the present study, we examined the antitumor effects of vitamins K2, K3 and K5 on PLC/PRF/5 human hepatocellular carcinoma (HCC) cells in vivo. Furthermore, to examine the mechanism of antitumor actions of these vitamins K, mRNA expression levels of various G1 phase-related cell cycle molecules were evaluated by using a real-time reverse transcription-polymerase chain reaction (RT-PCR) method. HCC-bearing animals were produced by implanting PLC/PRF/5 cells subcutaneously into athymic nude mice, and drinking water containing vitamin K2, K3 or K5 was given to the animals. Treatments with vitamins K2, K3 and K5 were shown to markedly inhibit the growth of HCC tumors. To examine the mechanism of in vivo antitumor effects of vitamins K, total RNA was extracted from HCC tumors, and the expression of G1 phase-related cell cycle molecules was quantitatively examined. Real-time RT-PCR demonstrated that the expression of the cell cycle-driving molecule, cyclin-dependent kinase 4 (Cdk4), in HCC was significantly reduced by the treatments with vitamin K2, K3 and K5. Conversely, the expression of the cell cycle-suppressing molecules, Cdk inhibitor p16INK4a and retinoblastoma, in HCC was significantly enhanced by the treatments with vitamins K2, K3 and K5. These results indicate that vitamins K2, K3 and K5 exert antitumor effects on HCC by regulating the expression of G1 phase-related cell cycle molecules. These results also indicate that vitamins K2, K3 and K5 may be useful agents for the treatment of patients with HCC.

  3. Grape seed proanthocyanidins reactivate silenced tumor suppressor genes in human skin cancer cells by targeting epigenetic regulators

    International Nuclear Information System (INIS)

    Vaid, Mudit; Prasad, Ram; Singh, Tripti; Jones, Virginia; Katiyar, Santosh K.

    2012-01-01

    Grape seed proanthocyanidins (GSPs) have been shown to have anti-skin carcinogenic effects in in vitro and in vivo models. However, the precise epigenetic molecular mechanisms remain unexplored. This study was designed to investigate whether GSPs reactivate silenced tumor suppressor genes following epigenetic modifications in skin cancer cells. For this purpose, A431 and SCC13 human squamous cell carcinoma cell lines were used as in vitro models. The effects of GSPs on DNA methylation, histone modifications and tumor suppressor gene expressions were studied in these cell lines using enzyme activity assays, western blotting, dot-blot analysis and real-time polymerase chain reaction (RT-PCR). We found that treatment of A431 and SCC13 cells with GSPs decreased the levels of: (i) global DNA methylation, (ii) 5-methylcytosine, (iii) DNA methyltransferase (DNMT) activity and (iv) messenger RNA (mRNA) and protein levels of DNMT1, DNMT3a and DNMT3b in these cells. Similar effects were noted when these cancer cells were treated identically with 5-aza-2′-deoxycytidine, an inhibitor of DNA methylation. GSPs decreased histone deacetylase activity, increased levels of acetylated lysines 9 and 14 on histone H3 (H3-Lys 9 and 14) and acetylated lysines 5, 12 and 16 on histone H4, and reduced the levels of methylated H3-Lys 9. Further, GSP treatment resulted in re-expression of the mRNA and proteins of silenced tumor suppressor genes, RASSF1A, p16 INK4a and Cip1/p21. Together, this study provides a new insight into the epigenetic mechanisms of GSPs and may have significant implications for epigenetic therapy in the treatment/prevention of skin cancers in humans. -- Highlights: ►Epigenetic modulations have been shown to have a role in cancer risk. ►Proanthocyanidins decrease the levels of DNA methylation and histone deacetylation. ►Proanthocyanidins inhibit histone deacetylase activity in skin cancer cells. ►Proanthocyanidins reactivate tumor suppressor genes in skin

  4. HPV type-related chromosomal profiles in high-grade cervical intraepithelial neoplasia

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    Bierkens Mariska

    2012-01-01

    Full Text Available Abstract Background The development of cervical cancer and its high-grade precursor lesions (Cervical Intraepithelial Neoplasia grade 2/3 [CIN2/3] result from a persistent infection with high-risk human papillomavirus (hrHPV types and the accumulation of (epigenetic host cell aberrations. Epidemiological studies have demonstrated variable CIN2/3 and cancer risks between different hrHPV types. Recent genomic profiling studies revealed substantial heterogeneity in the chromosomal aberrations detected in morphologically indistinguishable CIN2/3 suggestive of varying cancer risk. The current study aimed to investigate whether CIN2/3 with different hrHPV types vary with respect to their chromosomal profiles, both in terms of the number of aberrations and chromosomal loci affected. Methods Chromosomal profiles were determined of 43 p16INK4a-immunopositive CIN2/3 of women with long-term hrHPV infection (≥ 5 years. Sixteen lesions harboured HPV16, 3 HPV18, 14 HPV31, 1 HPV33, 4 HPV45, 1 HPV51, 2 HPV52 and 2 HPV58. Results Unsupervised hierarchical clustering analysis of the chromosomal profiles revealed two major clusters, characterised by either few or multiple chromosomal aberrations, respectively. A majority of 87.5% of lesions with HPV16 were in the cluster with relatively few aberrations, whereas no such unbalanced distribution was seen for lesions harbouring other hrHPV types. Analysis of the two most prevalent types (HPV16 and HPV31 in this data set revealed a three-fold increase in the number of losses in lesions with HPV31 compared to HPV16-positive lesions. In particular, losses at chromosomes 2q, 4p, 4q, 6p, 6q, 8q & 17p and gain at 1p & 1q were significantly more frequent in HPV31-positive lesions (FDR Conclusions Chromosomal aberrations in CIN2/3 are at least in part related to the hrHPV type present. The relatively low number of chromosomal aberrations observed in HPV16-positive CIN2/3 suggests that the development of these lesions is

  5. DNA methylation profiling of ovarian carcinomas and their in vitro models identifies HOXA9, HOXB5, SCGB3A1, and CRABP1 as novel targets

    Directory of Open Access Journals (Sweden)

    Tropé Claes G

    2007-07-01

    Full Text Available Abstract Background The epigenetics of ovarian carcinogenesis remains poorly described. We have in the present study investigated the promoter methylation status of 13 genes in primary ovarian carcinomas (n = 52 and their in vitro models (n = 4; ES-2, OV-90, OVCAR-3, and SKOV-3 by methylation-specific polymerase chain reaction (MSP. Direct bisulphite sequencing analysis was used to confirm the methylation status of individual genes. The MSP results were compared with clinico- pathological features. Results Eight out of the 13 genes were hypermethylated among the ovarian carcinomas, and altogether 40 of 52 tumours were methylated in one or more genes. Promoter hypermethylation of HOXA9, RASSF1A, APC, CDH13, HOXB5, SCGB3A1 (HIN-1, CRABP1, and MLH1 was found in 51% (26/51, 49% (23/47, 24% (12/51, 20% (10/51, 12% (6/52, 10% (5/52, 4% (2/48, and 2% (1/51 of the carcinomas, respectively, whereas ADAMTS1, MGMT, NR3C1, p14ARF, and p16INK4a were unmethylated in all samples. The methylation frequencies of HOXA9 and SCGB3A1 were higher among relatively early-stage carcinomas (FIGO I-II than among carcinomas of later stages (FIGO III-IV; P = 0.002, P = 0.020, respectively. The majority of the early-stage carcinomas were of the endometrioid histotype. Additionally, HOXA9 hypermethylation was more common in tumours from patients older than 60 years of age (15/21 than among those of younger age (11/30; P = 0.023. Finally, there was a significant difference in HOXA9 methylation frequency among the histological types (P = 0.007. Conclusion DNA hypermethylation of tumour suppressor genes seems to play an important role in ovarian carcinogenesis and HOXA9, HOXB5, SCGB3A1, and CRABP1 are identified as novel hypermethylated target genes in this tumour type.

  6. HPV E6/E7 RNA in situ hybridization signal patterns as biomarkers of three-tier cervical intraepithelial neoplasia grade.

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    Mark F Evans

    Full Text Available Cervical lesion grading is critical for effective patient management. A three-tier classification (cervical intraepithelial neoplasia [CIN] grade 1, 2 or 3 based on H&E slide review is widely used. However, for reasons of considerable inter-observer variation in CIN grade assignment and for want of a biomarker validating a three-fold stratification, CAP-ASCCP LAST consensus guidelines recommend a two-tier system: low- or high-grade squamous intraepithelial lesions (LSIL or HSIL. In this study, high-risk HPV E6/E7 and p16 mRNA expression patterns in eighty-six CIN lesions were investigated by RNAscope chromogenic in situ hybridization (CISH. Specimens were also screened by immunohistochemistry for p16INK4a (clone E6H4, and by tyramide-based CISH for HPV DNA. HPV genotyping was performed by GP5+/6+ PCR combined with cycle-sequencing. Abundant high-risk HPV RNA CISH signals were detected in 26/32 (81.3% CIN 1, 22/22 (100% CIN 2 and in 32/32 (100% CIN 3 lesions. CIN 1 staining patterns were typified (67.7% specimens by abundant diffusely staining nuclei in the upper epithelial layers; CIN 2 lesions mostly (66.7% showed a combination of superficial diffuse-stained nuclei and multiple dot-like nuclear and cytoplasmic signals throughout the epithelium; CIN 3 lesions were characterized (87.5% by multiple dot-like nuclear and cytoplasmic signals throughout the epithelial thickness and absence/scarcity of diffusely staining nuclei (trend across CIN grades: P<0.0001. These data are consistent with productive phase HPV infections exemplifying CIN 1, transformative phase infections CIN 3, whereas CIN 2 shows both productive and transformative phase elements. Three-tier data correlation was not found for the other assays examined. The dual discernment of diffuse and/or dot-like signals together with the assay's high sensitivity for HPV support the use of HPV E6/E7 RNA CISH as an adjunct test for deciding lesion grade when CIN 2 grading may be beneficial (e

  7. Protocol for Compass: a randomised controlled trial of primary HPV testing versus cytology screening for cervical cancer in HPV-unvaccinated and vaccinated women aged 25-69 years living in Australia.

    Science.gov (United States)

    Canfell, Karen; Saville, Marion; Caruana, Michael; Gebski, Val; Darlington-Brown, Jessica; Brotherton, Julia; Heley, Stella; Castle, Philip E

    2018-01-26

    Australia's National Cervical Screening Program (NCSP) currently recommends 2-year cytology in women aged 18-69 years. Following a review of the NCSP prompted by the implementation of human papillomavirus (HPV) vaccination, the programme will transition in 2017 to 5-year primary HPV screening with partial genotyping for HPV16/18 in women aged 25-74 years. Compass is a sentinel experience for the renewed NCSP and the first prospectively randomised trial of primary HPV screening compared with cytology to be conducted in a population with high uptake of HPV vaccination. This protocol describes the main Compass trial, which commenced after a pilot study of ~5000 women completed recruitment. Women aged 25-69 years will be randomised at a 1:2 allocation to (1) 2.5-year image-read, liquid-based cytology (LBC) screening with HPV triage of low-grade smears (active control Arm A) or (2) 5-year HPV screening with partial genotyping and referral of HPV16/18-positive women to colposcopy (intervention Arm B). Women in Arm B positive for other oncogenic HPV (not 16/18) will undergo secondary randomisation at a 1:1 allocation to either LBC or dual-stained (p16 INK4a and Ki-67) cytology testing (dual-stained cytology). The primary outcome is cumulative CIN3+ (CIN3, adenocarcinoma in situ and invasive cervical cancer) following a 5-year HPV exit testing round in both arms, in women randomised to the HPV arm versus women randomised to the LBC arm, based on an intention-to-treat analysis. The primary outcome will first be tested for non-inferiority and if declared, the primary outcome will be tested for superiority. A total of 36 300 women in birth cohorts not offered vaccination and 84 700 women in cohorts offered vaccination will be recruited, bringing the final sample size to 121 000. The trial is powered for the secondary outcome of cumulative CIN3+ in screen-negative women, adjusted for censoring after CIN2+ treatment and hysterectomy. Approved by the Bellberry Ethics

  8. HPV E6/E7 RNA In Situ Hybridization Signal Patterns as Biomarkers of Three-Tier Cervical Intraepithelial Neoplasia Grade

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    Evans, Mark F.; Peng, Zhihua; Clark, Kelli M.; Adamson, Christine S.-C.; Ma, Xiao-Jun; Wu, Xingyong; Wang, Hongwei; Luo, Yuling; Cooper, Kumarasen

    2014-01-01

    Cervical lesion grading is critical for effective patient management. A three-tier classification (cervical intraepithelial neoplasia [CIN] grade 1, 2 or 3) based on H&E slide review is widely used. However, for reasons of considerable inter-observer variation in CIN grade assignment and for want of a biomarker validating a three-fold stratification, CAP-ASCCP LAST consensus guidelines recommend a two-tier system: low- or high-grade squamous intraepithelial lesions (LSIL or HSIL). In this study, high-risk HPV E6/E7 and p16 mRNA expression patterns in eighty-six CIN lesions were investigated by RNAscope chromogenic in situ hybridization (CISH). Specimens were also screened by immunohistochemistry for p16INK4a (clone E6H4), and by tyramide-based CISH for HPV DNA. HPV genotyping was performed by GP5+/6+ PCR combined with cycle-sequencing. Abundant high-risk HPV RNA CISH signals were detected in 26/32 (81.3%) CIN 1, 22/22 (100%) CIN 2 and in 32/32 (100%) CIN 3 lesions. CIN 1 staining patterns were typified (67.7% specimens) by abundant diffusely staining nuclei in the upper epithelial layers; CIN 2 lesions mostly (66.7%) showed a combination of superficial diffuse-stained nuclei and multiple dot-like nuclear and cytoplasmic signals throughout the epithelium; CIN 3 lesions were characterized (87.5%) by multiple dot-like nuclear and cytoplasmic signals throughout the epithelial thickness and absence/scarcity of diffusely staining nuclei (trend across CIN grades: PHPV infections exemplifying CIN 1, transformative phase infections CIN 3, whereas CIN 2 shows both productive and transformative phase elements. Three-tier data correlation was not found for the other assays examined. The dual discernment of diffuse and/or dot-like signals together with the assay’s high sensitivity for HPV support the use of HPV E6/E7 RNA CISH as an adjunct test for deciding lesion grade when CIN 2 grading may be beneficial (e.g. among young women) or when ‘LSIL vs. HSIL’ assignment is

  9. Human Papillomavirus 16 Infection and TP53 Mutation: Two Distinct Pathogeneses for Oropharyngeal Squamous Cell Carcinoma in an Eastern Chinese Population.

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    Zhen Wang

    Full Text Available To investigate the clinicopathological characteristics, human papillomavirus (HPV infection, p53 expression, and TP53 mutations in oropharyngeal squamous cell carcinoma (OPSCC and determine their utility as prognostic predictors in a primarily eastern Chinese population.The HPV infection status was tested via p16INK4A immunohistochemistry and validated using PCR, reverse blot hybridization and in situ hybridization (ISH in 188 OPSCC samples. p53 expression levels and TP53 gene mutations were assessed through immunohistochemistry and sequencing, respectively. Clinicopathological characteristics and follow-up information were collected. Overall survival was estimated using the Log-rank test.Overall, 22 of the 188 OPSCC samples were associated with HPV infection. HPV16 was identified in all 22 samples, whereas no samples were positive for HPV18. All 22 HPV-associated OPSCC samples were p53 negative and lacked TP53 mutations. HPV16 positivity, female patients, non-smokers, and patients with histological grade I and stage N0 diseases showed better overall survival (p = 0.009, 0.003, 0.048, 0.009, and 0.004, respectively. No significant differences in overall survival between smoking and non-smoking patients were observed in the HPV-associated OPSCC group. Patients without mutations in TP53 exons 5-8 had better prognoses (p = 0.031 among the 43 sequenced specimens. Multivariate analysis indicated that HPV16 infection status (p = 0.011, histological grade (p = 0.017, and N stage (p = 0.019 were independent prognostic factors for patients with OPSCC.Distinct from the situation in Europe and America, for the patients with OPSCC in this study, HPV16 infection was relatively low, although it was still the most important independent prognostic predictor for the disease. In addition to the high smoking and drinking rate in this population, HPV16 infection and TP53 dysfunction appear to be two distinct pathogens for OPSCC patients in the eastern Chinese

  10. The human papillomavirus type 11 and 16 E6 proteins modulate the cell-cycle regulator and transcription cofactor TRIP-Br1

    International Nuclear Information System (INIS)

    Gupta, Sanjay; Takhar, Param Parkash S; Degenkolbe, Roland; Heng Koh, Choon; Zimmermann, Holger; Maolin Yang, Christopher; Guan Sim, Khe; I-Hong Hsu, Stephen; Bernard, Hans-Ulrich

    2003-01-01

    The genital human papillomaviruses (HPVs) are a taxonomic group including HPV types that preferentially cause genital and laryngeal warts ('low-risk types'), such as HPV-6 and HPV-11, or cancer of the cervix and its precursor lesions ('high-risk types'), such as HPV-16. The transforming processes induced by these viruses depend on the proteins E5, E6, and E7. Among these oncoproteins, the E6 protein stands out because it supports a particularly large number of functions and interactions with cellular proteins, some of which are specific for the carcinogenic HPVs, while others are shared among low- and high-risk HPVs. Here we report yeast two-hybrid screens with HPV-6 and -11 E6 proteins that identified TRIP-Br1 as a novel cellular target. TRIP-Br1 was recently detected by two research groups, which described two separate functions, namely that of a transcriptional integrator of the E2F1/DP1/RB cell-cycle regulatory pathway (and then named TRIP-Br1), and that of an antagonist of the cyclin-dependent kinase suppression of p16INK4a (and then named p34SEI-1). We observed that TRIP-Br1 interacts with low- and high-risk HPV E6 proteins in yeast, in vitro and in mammalian cell cultures. Transcription activation of a complex consisting of E2F1, DP1, and TRIP-Br1 was efficiently stimulated by both E6 proteins. TRIP-Br1 has an LLG E6 interaction motif, which contributed to the binding of E6 proteins. Apparently, E6 does not promote degradation of TRIP-Br1. Our observations imply that the cell-cycle promoting transcription factor E2F1/DP1 is dually targeted by HPV oncoproteins, namely (i) by interference of the E7 protein with repression by RB, and (ii) by the transcriptional cofactor function of the E6 protein. Our data reveal the natural context of the transcription activator function of E6, which has been predicted without knowledge of the E2F1/DP1/TRIP-Br/E6 complex by studying chimeric constructs, and add a function to the limited number of transforming properties shared

  11. STK35L1 associates with nuclear actin and regulates cell cycle and migration of endothelial cells.

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    Pankaj Goyal

    Full Text Available BACKGROUND: Migration and proliferation of vascular endothelial cells are essential for repair of injured endothelium and angiogenesis. Cyclins, cyclin-dependent kinases (CDKs, and cyclin-dependent kinase inhibitors play an important role in vascular tissue injury and wound healing. Previous studies suggest a link between the cell cycle and cell migration: cells present in the G(1 phase have the highest potential to migrate. The molecular mechanism linking these two processes is not understood. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we explored the function of STK35L1, a novel Ser/Thr kinase, localized in the nucleus and nucleolus of endothelial cells. Molecular biological analysis identified a bipartite nuclear localization signal, and nucleolar localization sequences in the N-terminal part of STK35L1. Nuclear actin was identified as a novel binding partner of STK35L1. A class III PDZ binding domains motif was identified in STK35L1 that mediated its interaction with actin. Depletion of STK35L1 by siRNA lead to an accelerated G(1 to S phase transition after serum-stimulation of endothelial cells indicating an inhibitory role of the kinase in G(1 to S phase progression. Cell cycle specific genes array analysis revealed that one gene was prominently downregulated (8.8 fold in STK35L1 silenced cells: CDKN2A alpha transcript, which codes for p16(INK4a leading to G(1 arrest by inhibition of CDK4/6. Moreover in endothelial cells seeded on Matrigel, STK35L1 expression was rapidly upregulated, and silencing of STK35L1 drastically inhibited endothelial sprouting that is required for angiogenesis. Furthermore, STK35L1 depletion profoundly impaired endothelial cell migration in two wound healing assays. CONCLUSION/SIGNIFICANCE: The results indicate that by regulating CDKN2A and inhibiting G1- to S-phase transition STK35L1 may act as a central kinase linking the cell cycle and migration of endothelial cells. The interaction of STK35L1 with nuclear

  12. [Verification of doubtful PAP smear results of women included in the screening program in the Podlaskie province].

    Science.gov (United States)

    Błońska, Ewa; Knapp, Piotr Andrzej

    2013-08-01

    Verification of uncertain PAP-smear results in a group of women covered by the cervical screening program in the Podlaski province. The main aim of the study was to identify CIN (Cervical Intraepithelial Neoplasia) lesions present, with varying degrees of severity in women with cytological diagnosis of ASCUS (atypical squamous cells of undetermined significance), LSIL (low grade squamous intraepithelial lesion), and ASC-H (atypical squamous cells - cannot exclude high grade squamous intraepithelial lesion). The study evaluated 101 cervical smears taken from the vaginal part of the cervix in a group of screened women in the Podlaski province. Cytological evaluation was performed according the Bethesda System. We analyzed abnormal smears selected from a total of 7296 cytological examinations performed during 2012 at the University Center for Pathomorphological and Genetic - Molecular Diagnosis, Medical University in Białystok. The cytological results which were of interest to us included 19 cases with ASCUS, 59 with LSIL, and 23 with ASC-H, as well as with morphological features of the presence of Human Papilloma Virus (HPV). Staining was performed using CINtecPLUS test according to the manufacturer's instructions. CINtecPLUS is a immunocytochemical test based on specially designed monoclonal antibodies (E6H4TM) that let us identify protein p16ink4a within the cervical smear Additionally the diagnostic kit was provided with antibodies for diagnosing the presence of Ki-67 protein, a known marker of cell proliferation. The result was considered positive when staining of the nucleus and the cytoplasm appeared in red and brown, respectively. All abnormal results were eventually verified by histological examination of the tissue taken from cervical lesions by diagnostic-therapeutic procedure following colposcopic evaluation of cervical lesion topography In the group of cytological smears with ASCUS, the diagnosis was positive in 5 cases (26.3%), negative in 14 (73

  13. Kallistatin reduces vascular senescence and aging by regulating microRNA-34a-SIRT1 pathway.

    Science.gov (United States)

    Guo, Youming; Li, Pengfei; Gao, Lin; Zhang, Jingmei; Yang, Zhirong; Bledsoe, Grant; Chang, Eugene; Chao, Lee; Chao, Julie

    2017-08-01

    Kallistatin, an endogenous protein, protects against vascular injury by inhibiting oxidative stress and inflammation in hypertensive rats and enhancing the mobility and function of endothelial progenitor cells (EPCs). We aimed to determine the role and mechanism of kallistatin in vascular senescence and aging using cultured EPCs, streptozotocin (STZ)-induced diabetic mice, and Caenorhabditis elegans (C. elegans). Human kallistatin significantly decreased TNF-α-induced cellular senescence in EPCs, as indicated by reduced senescence-associated β-galactosidase activity and plasminogen activator inhibitor-1 expression, and elevated telomerase activity. Kallistatin blocked TNF-α-induced superoxide levels, NADPH oxidase activity, and microRNA-21 (miR-21) and p16 INK 4a synthesis. Kallistatin prevented TNF-α-mediated inhibition of SIRT1, eNOS, and catalase, and directly stimulated the expression of these antioxidant enzymes. Moreover, kallistatin inhibited miR-34a synthesis, whereas miR-34a overexpression abolished kallistatin-induced antioxidant gene expression and antisenescence activity. Kallistatin via its active site inhibited miR-34a, and stimulated SIRT1 and eNOS synthesis in EPCs, which was abolished by genistein, indicating an event mediated by tyrosine kinase. Moreover, kallistatin administration attenuated STZ-induced aortic senescence, oxidative stress, and miR-34a and miR-21 synthesis, and increased SIRT1, eNOS, and catalase levels in diabetic mice. Furthermore, kallistatin treatment reduced superoxide formation and prolonged wild-type C. elegans lifespan under oxidative or heat stress, although kallistatin's protective effect was abolished in miR-34 or sir-2.1 (SIRT1 homolog) mutant C. elegans. Kallistatin inhibited miR-34, but stimulated sir-2.1 and sod-3 synthesis in C. elegans. These in vitro and in vivo studies provide significant insights into the role and mechanism of kallistatin in vascular senescence and aging by regulating miR-34a-SIRT1

  14. Prevalence of variations in melanoma susceptibility genes among Slovenian melanoma families

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    Besic Nikola

    2008-09-01

    Full Text Available Abstract Background Two high-risk genes have been implicated in the development of CM (cutaneous melanoma. Germline mutations of the CDKN2A gene are found in CDK4 gene reported to date. Beside those high penetrance genes, certain allelic variants of the MC1R gene modify the risk of developing the disease. The aims of our study were: to determine the prevalence of germline CDKN2A mutations and variants in members of families with familial CM and in patients with multiple primary CM; to search for possible CDK4 mutations, and to determine the frequency of variations in the MC1R gene. Methods From January 2001 until January 2007, 64 individuals were included in the study. The group included 28 patients and 7 healthy relatives belonging to 25 families, 26 patients with multiple primary tumors and 3 children with CM. Additionally 54 healthy individuals were included as a control group. Mutations and variants of the melanoma susceptibility genes were identified by direct sequencing. Results Seven families with CDKN2A mutations were discovered (7/25 or 28.0%. The L94Q mutation found in one family had not been previously reported in other populations. The D84N variant, with possible biological impact, was discovered in the case of patient without family history but with multiple primary CM. Only one mutation carrier was found in the control group. Further analysis revealed that c.540C>T heterozygous carriers were more common in the group of CM patients and their healthy relatives (11/64 vs. 2/54. One p14ARF variant was discovered in the control group and no mutations of the CDK4 gene were found. Most frequently found variants of the MC1R gene were T314T, V60L, V92M, R151C, R160W and R163Q with frequencies slightly higher in the group of patients and their relatives than in the group of controls, but the difference was statistically insignificant. Conclusion The present study has shown high prevalence of p16INK4A mutations in Slovenian population of

  15. Senescence-Derived Extracellular Molecules as Modulators of Oral Cancer Development: A Mini-Review.

    Science.gov (United States)

    Parkinson, Eric Kenneth; James, Emma L; Prime, Stephen S

    2016-01-01

    Oral cancers are predominantly oral squamous cell carcinomas (OSCCs) derived from keratinocytes, and there is now very detailed knowledge of the genetics and molecular biology of the epithelial tumourigenic component of these cancers, including the identification of cancer stem or tumour-initiating cells. Several key genetic alterations have been identified including the near ubiquitous loss of the CDKN2A/p16INK4A and p53 pathways and telomerase activation, together with frequent inactivation of the NOTCH1 canonical pathway either by somatic genetic alterations or by the presence of human papilloma virus. There is also evidence that OSCCs arise from a 'field' of altered cells and that malignant conversion takes place pre-dominantly at the microscopic level. However, in the last decade, it has been realised that tumour development and progression are influenced by the cells of the microenvironment with cross-talk between the epithelial (tumour) and mesenchymal components. OSCCs, especially those that have bypassed cellular senescence, produce an array of proteins and metabolites that induce cellular senescence in the normal surrounding cells; indeed, senescence is a common property of cancer-associated fibroblasts (CAFs). Cellular senescence is defined as an irreversible cell cycle arrest and is associated with the release of molecules known as the senescence-associated secretory phenotype that can selectively promote the growth of pre-neoplastic keratinocytes (osteopontin) and cancer invasion (transforming growth factor β, matrix metalloproteinases, interleukin 6 and lactate). In addition, both old and new work has shown that keratinocytes harbouring NOTCH loss-of-function mutations that lead to defective keratinocyte differentiation and loss of squamous epithelial barrier function may act as a tumour-promoting stimulus for initiated cells harbouring RAS pathway mutations by activating a wound response in the tumour mesenchyme. Thus, not all keratinocytes in the

  16. [PRODUCT OF THE BMI1--A KEY COMPONENT OF POLYCOMB--POSITIVELY REGULATES ADIPOCYTE DIFFERENTIATION OF MOUSE MESENCHYMAL STEM CELLS].

    Science.gov (United States)

    Petrov, N S; Vereschagina, N A; Sushilova, E N; Kropotov, A V; Miheeva, N F; Popov, B V

    2016-01-01

    Bmil is a key component of Polycomb (PcG), which in mammals controls the basic functions of mammalian somatic stem cells (SSC) such as self-renewal and differentiation. Bmi1 supports SSC via transcriptional suppression of genes associated with cell cycle and differentiation. The most studied target genes of Bmi1 are the genes of Ink4 locus, CdkI p16(Ink4a) and p1(Arf), suppression of which due to activating mutations of the BMI1 results in formation of cancer stem cells (CSC) and carcinomas in various tissues. In contrast, inactivation of BMI1 results in cell cycle arrest and cell senescence. Although clinical phenomena of hypo- and hyperactivation of BMI1 are well known, its targets and mechanisms of regulation of tissue specific SSC are still obscure. The goal of this study was to evaluate the regulatory role of BMI1 in adipocyte differentiation (AD) of mouse mesenchymal stem cells (MSC). Induction of AD in mouse MSC of the C3H10T1/2 cell line was associated with an increase in the expression levels of BMI1, the genes of pRb family (RB, p130) and demethylase UTX, but not methyltransferase EZH2, whose products regulate the methylation levels of H3K27. It was observed earlier that H3K27me3 may play the role of the epigenetic switch by promoting AD of human MSC via activating expression of the PPARγ2, the master gene of AD (Hemming et al., 2014). Here we show that inactivation of BMI1 using specific siRNA slows and decreases the levels of AD, but does not abolish it. This is associated with a complete inhibition of the expression of adipogenic marker genes--PPARγ2, ADIPOQ and a decrease in the expression of RB, p130, but not UTX. The results obtained give evidence that the epigenetic mechanism regulating AD differentiation in mouse and human MSC is different.

  17. Pathogenic role of the eight probably/possibly carcinogenic HPV types 26, 53, 66, 67, 68, 70, 73 and 82 in cervical cancer.

    Science.gov (United States)

    Halec, Gordana; Alemany, Laia; Lloveras, Belen; Schmitt, Markus; Alejo, Maria; Bosch, Franz X; Tous, Sara; Klaustermeier, Jo Ellen; Guimerà, Nuria; Grabe, Niels; Lahrmann, Bernd; Gissmann, Lutz; Quint, Wim; Bosch, Francesc X; de Sanjose, Silvia; Pawlita, Michael

    2014-12-01

    Eight HPV types (HPV26, 53, 66, 67, 68, 70, 73 and 82) that are phylogenetically closely related to 12 WHO-defined high-risk (HR) HPV have been rarely but consistently identified as single HPV infections in about 3% of cervical cancer (CxCa) tissues. Due to lack of biological data, these types are referred to as probable/possible (p) HR-HPV. To analyse their biological activity in direct comparison to HR-HPV types, we selected 55 formalin-fixed, paraffin-embedded (FFPE) CxCa tissues harbouring single pHR-HPV infections (2-13 cases per type) and 266 tissues harbouring single HR-HPV (7-40 cases per type) from a worldwide, retrospective, cross-sectional study. Single HPV infection was verified by two genotyping methods. Presence of type-specific spliced E6*I mRNA transcripts and expression of cellular proteins indicative of HPV transformation were assessed in all cases. In 55 CxCa tissues with pHR-HPV, E6*I mRNA expression was 100%; high p16(INK4a) , 98%; low pRb, 96%; low CyD1, 93%; and low p53, 84%. Compared to HPV16 tissues as a reference, individual frequencies of these five markers did not differ significantly, either for any of the eight pHR-HPV and the 11 other HR types individually or for the groups of pHR and HR types without HPV16. We conclude that the eight pHR-HPV types, when present as a single infection in CxCa, are biologically active and affect the same cellular pathways as any of the fully recognized carcinogenic HR-HPV types. Therefore we have provided molecular evidence of carcinogenicity for types currently classified as probably/possibly carcinogenic. Although this evidence is crucial for HPV-type carcinogenicity classification, per se it is not sufficient for inclusion of these HPV types into population-wide primary and secondary prevention programmes. Such decisions have to include careful estimation of effectiveness and cost-benefit analyses. Copyright © 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons

  18. Down-regulation of p21 (CDKN1A/CIP1) is inversely associated with microsatellite instability and CpG island methylator phenotype (CIMP) in colorectal cancer.

    Science.gov (United States)

    Ogino, S; Kawasaki, T; Kirkner, G J; Ogawa, A; Dorfman, I; Loda, M; Fuchs, C S

    2006-10-01

    p21 (CDKN1A/CIP1/WAF1), one of the cyclin-dependent kinase inhibitors, plays a key role in regulating the cell cycle and is transcriptionally regulated by p53. Down-regulation of p21 is caused by TP53 mutations in colorectal cancer. CpG island methylator phenotype (CIMP) appears to be a distinct subtype of colorectal cancer with concordant methylation of multiple gene promoters and is associated with a high degree of microsatellite instability (MSI-H) and BRAF mutations. However, no study to date has evaluated the relationship between p21 expression and CIMP in colorectal cancer. The purpose of this study was to examine the inter-relationships between p21, p53, CIMP, MSI and KRAS/BRAF status in colorectal cancer. We utilized 737 relatively unbiased samples of colorectal cancers from two large prospective cohort studies. Using quantitative real-time PCR (MethyLight), we measured DNA methylation in five CIMP-specific gene promoters [CACNA1G, CDKN2A (p16/INK4A), CRABP1, MLH1 and NEUROG1]. CIMP-high (>or=4/5 methylated promoters) was diagnosed in 118 (16%) of the 737 tumours. We also assessed expression of p21 and p53 by immunohistochemistry. Among the 737 tumours, 371 (50%) showed p21 loss. Both p21 loss and p53 positivity were inversely associated with CIMP-high, MSI-H and BRAF mutations. The associations of p21 with these molecular features were still present after tumours were stratified by p53 status. In contrast, the associations of p53 positivity with the molecular features were no longer present after tumours were stratified by p21 status. When CIMP-high and non-CIMP-high tumours were stratified by MSI or KRAS/BRAF status, CIMP-high and MSI-H (but not BRAF mutations) were still inversely associated with p21 loss. In conclusion, down-regulation of p21 is inversely correlated with CIMP-high and MSI-H in colorectal cancer, independent of TP53 and BRAF status.

  19. CDKN1C/p57kip2 is a candidate tumor suppressor gene in human breast cancer

    International Nuclear Information System (INIS)

    Larson, Pamela S; Schlechter, Benjamin L; King, Chia-Lin; Yang, Qiong; Glass, Chelsea N; Mack, Charline; Pistey, Robert; Morenas, Antonio de las; Rosenberg, Carol L

    2008-01-01

    CDKN1C (also known as p57 KIP2 ) is a cyclin-dependent kinase inhibitor previously implicated in several types of human cancer. Its family members (CDKN1A/p21 CIP1 and B/p27 KIP1 ) have been implicated in breast cancer, but information about CDKN1C's role is limited. We hypothesized that decreased CDKN1C may be involved in human breast carcinogenesis in vivo. We determined rates of allele imbalance or loss of heterozygosity (AI/LOH) in CDKN1C, using an intronic polymorphism, and in the surrounding 11p15.5 region in 82 breast cancers. We examined the CDKN1C mRNA level in 10 cancers using quantitative real-time PCR (qPCR), and the CDKN1C protein level in 20 cancers using immunohistochemistry (IHC). All samples were obtained using laser microdissection. Data were analyzed using standard statistical tests. AI/LOH at 11p15.5 occurred in 28/73 (38%) informative cancers, but CDKN1C itself underwent AI/LOH in only 3/16 (19%) cancers (p = ns). In contrast, CDKN1C mRNA levels were reduced in 9/10 (90%) cancers (p < 0.0001), ranging from 2–60% of paired normal epithelium. Similarly, CDKN1C protein staining was seen in 19/20 (95%) cases' normal epithelium but in only 7/14 (50%) cases' CIS (p < 0.004) and 5/18 (28%) cases' IC (p < 0.00003). The reduction appears primarily due to loss of CDKN1C expression from myoepithelial layer cells, which stained intensely in 17/20 (85%) normal lobules, but in 0/14 (0%) CIS (p < 0.00001). In contrast, luminal cells displayed less intense, focal staining fairly consistently across histologies. Decreased CDKN1C was not clearly associated with tumor grade, histology, ER, PR or HER2 status. CDKN1C is expressed in normal epithelium of most breast cancer cases, mainly in the myothepithelial layer. This expression decreases, at both the mRNA and protein level, in the large majority of breast cancers, and does not appear to be mediated by AI/LOH at the gene. Thus, CDKN1C may be a breast cancer tumor suppressor

  20. SKLB188 inhibits the growth of head and neck squamous cell carcinoma by suppressing EGFR signalling.

    Science.gov (United States)

    Barzegar, Mansoureh; Ma, Shuang; Zhang, Chao; Chen, Xin; Gu, Ying; Shang, Chaowei; Jiang, Xiaojuan; Yang, Jiao; Nathan, Cherie-Ann; Yang, Shengyong; Huang, Shile

    2017-10-10

    Overexpression of epidermal growth factor receptor (EGFR) occurs in approximately 90% of head and neck squamous cell carcinoma (HNSCC), and is correlated with poor prognosis. Thus, targeting EGFR is a promising strategy for treatment of HNSCC. Several small molecule EGFR inhibitors have been tested in clinical trials for treatment of HNSCC, but none of them are more effective than the current chemotherapeutic drugs. Thus, it is urgently needed to develop novel EGFR inhibitors for HNSCC treatment. By screening an in-house focused library containing approximately 650 000 known kinase inhibitors and kinase inhibitor-like compounds containing common kinase inhibitor core scaffolds, we identified SKLB188 as a lead compound for inhibition of EGFR. The anticancer effects of SKLB188 on HNSCC cells were investigated by in vitro cell growth, cell cycle and apoptosis assays, as well as in vivo FaDu xenograft mouse model. Molecular docking, in vitro kinase profiling and western blotting were performed to characterise EGFR as the molecular target. SKLB188 inhibited HNSCC cell proliferation by inducing G 1 cell cycle arrest, which was associated with downregulating the expression of Cdc25A, cyclins D1/A and cyclin-dependent kinases (CDK2/4), and upregulating the expression of cyclin-dependent kinase (CDK) inhibitors (p21 Cip1 and p27 Kip1 ), leading to decreased phosphorylation of Rb. SKLB188 also induced caspase-dependent apoptosis of HNSCC cells by downregulating the expression of Mcl-1 and survivin. Molecular docking revealed that SKLB188 could bind to the kinase domain of EGFR through hydrogen bonds and hydrophobic interactions. In vitro kinase assay showed that SKLB188 inhibited the activity of a recombinant human EGFR very potently (IC 50 =5 nM). Western blot analysis demonstrated that SKLB188 inhibited the phosphorylation of EGFR and its downstream targets, extracellular signal-regulated protein kinases 1 and 2 (Erk1/2) and Akt in the cells. In addition, SKLB188 dose

  1. Enhancer of the rudimentary gene homologue (ERH expression pattern in sporadic human breast cancer and normal breast tissue

    Directory of Open Access Journals (Sweden)

    Knüchel Ruth

    2008-05-01

    Full Text Available Abstract Background The human gene ERH (Enhancer of the Rudimentary gene Homologue has previously been identified by in silico analysis of four million ESTs as a gene differentially expressed in breast cancer. The biological function of ERH protein has not been fully elucidated, however functions in cell cycle progression, pyrimidine metabolism a possible interaction with p21(Cip1/Waf1 via the Ciz1 zinc finger protein have been suggested. The aim of the present study was a systematic characterization of ERH expression in human breast cancer in order to evaluate possible clinical applications of this molecule. Methods The expression pattern of ERH was analyzed using multiple tissue northern blots (MTN on a panel of 16 normal human tissues and two sets of malignant/normal breast and ovarian tissue samples. ERH expression was further analyzed in breast cancer and normal breast tissues and in tumorigenic as well as non-tumorigenic breast cancer cell lines, using quantitative RT-PCR and non-radioisotopic in situ hybridization (ISH. Results Among normal human tissues, ERH expression was most abundant in testis, heart, ovary, prostate, and liver. In the two MTN sets of malignant/normal breast and ovarian tissue,ERH was clearly more abundantly expressed in all tumours than in normal tissue samples. Quantitative RT-PCR analyses showed that ERH expression was significantly more abundant in tumorigenic than in non-tumorigenic breast cancer cell lines (4.5-fold; p = 0.05, two-tailed Mann-Whitney U-test; the same trend was noted in a set of 25 primary invasive breast cancers and 16 normal breast tissue samples (2.5-fold; p = 0.1. These findings were further confirmed by non-radioisotopic ISH in human breast cancer and normal breast tissue. Conclusion ERH expression is clearly up-regulated in malignant as compared with benign breast cells both in primary human breast cancer and in cell models of breast cancer. Since similar results were obtained for ovarian

  2. FOG-2 mediated recruitment of the NuRD complex regulates cardiomyocyte proliferation during heart development.

    Science.gov (United States)

    Garnatz, Audrey S; Gao, Zhiguang; Broman, Michael; Martens, Spencer; Earley, Judy U; Svensson, Eric C

    2014-11-01

    FOG-2 is a multi-zinc finger protein that binds the transcriptional activator GATA4 and modulates GATA4-mediated regulation of target genes during heart development. Our previous work has demonstrated that the Nucleosome Remodeling and Deacetylase (NuRD) complex physically interacts with FOG-2 and is necessary for FOG-2 mediated repression of GATA4 activity in vitro. However, the relevance of this interaction for FOG-2 function in vivo has remained unclear. In this report, we demonstrate the importance of FOG-2/NuRD interaction through the generation and characterization of mice homozygous for a mutation in FOG-2 that disrupts NuRD binding (FOG-2(R3K5A)). These mice exhibit a perinatal lethality and have multiple cardiac malformations, including ventricular and atrial septal defects and a thin ventricular myocardium. To investigate the etiology of the thin myocardium, we measured the rate of cardiomyocyte proliferation in wild-type and FOG-2(R3K5A) developing hearts. We found cardiomyocyte proliferation was reduced by 31±8% in FOG-2(R3K5A) mice. Gene expression analysis indicated that the cell cycle inhibitor Cdkn1a (p21(cip1)) is up-regulated 2.0±0.2-fold in FOG-2(R3K5A) hearts. In addition, we demonstrate that FOG-2 can directly repress the activity of the Cdkn1a gene promoter, suggesting a model by which FOG-2/NuRD promotes ventricular wall thickening by repression of this cell cycle inhibitor. Consistent with this notion, the genetic ablation of Cdkn1a in FOG-2(R3K5A) mice leads to an improvement in left ventricular function and a partial rescue of left ventricular wall