Possible associations among expression of p14(ARF), p16(INK4a), p21(WAF1/CIP1), p27(KIP1), and p53 accumulation and the balance of apoptosis and cell proliferation in ovarian carcinomas

Investigation of the Effect of 5-Aza-2'-Deoxycytidine in Comparison to and in Combination with Trichostatin A on p16INK4a, p14ARF, p15INK4b Gene Expression, Cell Growth Inhibition and Apoptosis Induction in Colon Cancer Caco-2 Cell Line

Background

The cell cycle is divided into four phases, G1, G2, S, and M phase. The mammalian cell cycle is controlled and governed by the kinase complexes including cyclin and the cyclin-dependent kinase (CDK), cyclin-CDK complexes. The activity of the complexes is regulated by cyclin-dependent kinase inhibitors (CDKIs), the INK4, and the CDK interacting protein/kinase inhibitory protein (CIP/KIP) families. Promoter hypermethylation and histone deacetylation of CDKIs have been reported in several cancers. These changes can be reversed by DNA demethylating agents, such as decitabine, 5-Aza-2'-deoxycytidine (5-Aza-CdR), and histone deacetylase inhibitors (HDACIs), such as trichostatin A. Previously, we reported the effect of 5-Aza-CdR and trichostatin A (TSA) on hepatocellular carcinoma (HCC). The present study aimed to investigate the effect of 5-Aza-CdR in comparison to and in combination with trichostatin A on p16INK4a, p14ARF, p15INK4b genes expression, cell growth inhibition and apoptosis induction in colon cancer Caco-2 cell line.

Methods

The Caco-2 cells were cultured and treated with 5-Aza-CdR and TSA (alone and combined). The cell viability, apoptosis, and relative gene expression were determined by MTT assay, flow cytometry, and real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR), respectively.

Results

Both compounds inhibited cell growth, induced apoptosis, and up-regulated the p16INK4a, p14ARF, p15INK4b gene significantly. The TSA had a more significant effect in comparison to 5-Aza-CdR. Furthermore, maximal apoptosis and up-regulation were observed with combined treatment.

Conclusions

our finding indicated that 5-Aza-CdR and TSA can epigenetically re-activate the p16INK4a, p14ARF, p15INK4b gene resulting in cell growth inhibition and apoptosis induction in colon cancer.

Effect of vorinostat on INK4 family and HDACs 1, 2, and 3 in pancreatic cancer and hepatocellular carcinoma

Background and purpose:

In mammalian cells, several distinct surveillance systems, named cell cycle checkpoints, can interrupt normal cell-cycle progression. The cyclin-dependent kinases are negatively regulated by proteins of cyclin-dependent kinases inhibitors comprising INK4 and Cip/Kip families. Histone deacetylation induced by histone deacetylases (HDACs) inactivates the INK4 and Cip/Kip families lead to cancer induction. HDAC inhibitors (HDACIs) have been indicated to be potent inducers of differentiation, growth arrest, and apoptotic induction. Vorinostat (suberoylanilide hydroxamic acid, SAHA), as an HDACI, is reported to be useful in various cancers. Previously, we reported the effect of trichostatin A on hepatocellular carcinoma and also vorinostat on colon cancer cell lines. The current study was aimed to investigate the effect of vorinostat on p16INK4a, p14ARF, p15INK4b, and class I HDACs 1, 2, and 3 gene expression, cell growth inhibition, and apoptosis induction in pancreatic cancer AsPC-1 and hepatocellular carcinoma LCL-PI 11 cell lines.

Experimental approach:

The AsPC-1 and LCL-PI 11 cell lines were cultured and treated with vorinostat. To determine, viability, apoptosis, and the relative expression level of p16INK4a, p14ARF, p15INK4b, class I HDACs 1, 2, and 3 genes, MTT assay, cell apoptosis assay, and RT-qPCR were performed, respectively.

Findings/Results:

Vorinostat significantly inhibited cell growth, induced apoptosis, increased p16INK4a, p14ARF, p15INK4b, and decreased class I HDACs 1, 2, and 3 gene expression.

Conclusion and implications:

Vorinostat can reactivate the INK4 family through inhibition of class I HDACs 1, 2, and 3 genes activity.

Investigation of the Effect of 5-Aza-2'-Deoxycytidine on p15INK4, p16INK4, p18INK4, and p19INK4 Genes Expression, Cell Growth Inhibition, and Apoptosis Induction in Hepatocellular Carcinoma PLC/PRF/5 Cell Line

Background

Cyclin-dependent kinases (CDKs) are the key regulators of cell-cycle transitions and characterized by needing a separate subunit, a cyclin, which provides domains essential for enzymatic activity. The activities of cyclin-CDK complexes are controlled by a group of molecules that inhibit CDK activity and CDK inhibitors (CKIs). Cancer often exhibits an aberrant CpG methylation of promoter regions of tumor suppressor genes such as CKIs. Treatment with the DNA demethylating agents, such as 5-aza-2'-deoxycytidine (5-Aza-CdR), can restore and upregulate CKIs. Previously, we reported the effect of 5-Aza-CdR and genistein on DNA methyltransferase (DNMTs) in hepatocellular carcinoma (HCC). The aim of the present study was to evaluate the effect of 5-Aza-CdR on p15INK4, p16INK4, p18INK4, and p19INK4 genes expression, cell growth inhibition, and apoptosis induction in HCC PLC/PRF/5 cell line.

Materials and Methods

The effect of 5-Aza-CdR on the cell growth of PLC/PRF/5 cells, genes expression, and apoptosis induction were assessed by 3-[4, 5-dimethyl-2-thiazolyl]-2, 5-diphenyl-2H-tetrazolium bromide assay, real-time quantitative reverse transcription-polymerase chain reaction analysis, and flow cytometry, respectively.

Results

5-Aza-CdR (0, 1, 5, 10, 25, and 50 μM) inhibited PLC/PRF/5 cell growth at different periods significantly. This compound induced apoptosis and reactivated p15INK4, p16INK4, p18INK4, and p19INK4 genes expression at a concentration of 5 μM significantly.

Conclusion

5-Aza-CdR can inhibit cell viability and induce apoptosis by epigenetic reactivation of p15INK4, p16INK4, p18INK4, and p19INK4 genes in HCC PLC/PRF/5.

Origins based clinical and molecular complexities of epithelial ovarian cancer

Ovarian cancer is the most lethal of all common gynaecological malignancies in women worldwide. Ovarian cancer comprises of >15 distinct tumor types and subtypes characterized by histopathological features, environmental and genetic risk factors, precursor lesions and molecular events during oncogenesis. Recent studies on gene signature profiling of different subtypes of ovarian cancer have revealed significant genetic heterogeneity between and within each ovarian cancer histological subtype. Thus, an immense interest have shown towards a more personalized medicine for understanding the clinical and molecular complexities of four major types of epithelial ovarian cancer (serous, endometrioid, clear cell, and mucinous). As such, further in depth studies are needed for identification of molecular signalling network complexities associated with effective prognostication and targeted therapies to prevent or treat metastasis. Therefore, understanding the metastatic potential of primary ovarian cancer and therapeutic interventions against lethal ovarian cancer for the development of personalized therapies is very much indispensable. Consequently, in this review we have updated the key dysregulated genes of four major subtypes of epithelial carcinomas. We have also highlighted the recent advances and current challenges in unravelling the complexities of the origin of tumor as well as genetic heterogeneity of ovarian cancer.

The ARID1A, p53 and ß-Catenin statuses are strong prognosticators in clear cell and endometrioid carcinoma of the ovary and the endometrium

Aim

The objective of this study was to evaluate the prognostic value of ARID1A, p53, p21, p16 and ß-Catenin in endometrioid and clear cell ovarian and endometrial carcinomas.

Materials and methods

97 tumors were available for analysis of ARID1A, p53, p21, p16 and ß-Catenin with the techniques of tissue microarray and immunohistochemistry. 32 were ovarian carcinomas and 65 were endometrial carcinomas.

Results

Endometrioid ovarian carcinomas showed negative staining for ARID1A (a) and p21 (b), aberrant expression of p53 (c) and p16 (d) and ß-Catenin positive nuclear expression (e) respectively in 19% (a), 100% (b), 28.6% (c), 52.4% (d) and 4.8% (e) of all cases. In the group of clear cell ovarian carcinomas it was 63.6% (a), 100% (b), 81.8% (c), 54.5% (d) and 0% (e). For endometrioid uterine carcinomas it was 75.7% (a), 94.9% (b), 30.5% (c), 52.1% (d) and 6.8% (e) and for clear cell uterine carcinomas it was 8.6% (a), 100% (b), 50% (c), 100% (d) and 0% (e). Survival analysis showed that negative expression of ARID1A, p53 aberrant expression and ß-Catenin nuclear positive staining are independent negative prognosticators in both, clear cell and endometrioid carcinoma, regardless of ovarian or uterine origin. Cox-Regression analysis showed them again as negative prognostic factors. Furthermore, we found a significant correlation between ARID1A and ß-Catenin expression in endometrioid uterine tumors.

Conclusion

The analyzed gynaecological carcinoma showed a distinct expression scheme of proteins that are associated with tumor suppression. We may conclude that ARID1A, p53 and ß-Catenin are the strongest prognostic factors by analyzing a subgroup of tumor suppressor genes in clear cell and endometrioid subtypes of ovarian and endometrial cancer and may be used along with traditional morphological and clinical characteristics for prognosis.

Molecular insights into the transcriptional regulatory role of thyroid hormones in ovarian cancer

The regulation of cancer-relevant genes by the thyroid hormones, 3, 5, 3'-Triiodo-L-thyronine (T3) and L-thyroxine (T4), was recently acknowledged. However, limited data exists on the hormonal effects on gene expression in ovarian cancer, a gynecological malignancy associated with a low cure rate. The expression of fifteen genes involved in DNA repair, cell cycle, apoptosis, and tumor suppression was evaluated in OVCAR-3 and A2780 cell lines, using real-time PCR following short incubation with T3 (1 nM) or T4 (100 nM). The thyroid hormones downregulated the expression of the majority of genes examined. Support for the involvement of the MAPK and PI3K in thyroid hormone-mediated gene expression was shown for a set of genes. FAS expression was inhibited in A2780 cells, while an unexpected induction was demonstrated in OVCAR-3 cells. An analogous effect on the protein levels of FAS receptor and its soluble form was demonstrated by Western blotting. We further established, using primer sets that discriminate between the different RNA isoforms, that the hormones increase the mRNA levels of both coding and non-coding FAS mRNAs. The prevalence of these isoforms, using The Cancer Genome Atlas (TCGA) analysis, was significantly more abundant in 17 cancer types, including ovarian cancer, compared to normal tissues. Our results highlight the role of thyroid hormones in the expression of cancer-relevant-genes in ovarian cancer and provide an important insight into the pathways by which mitogenic and anti-apoptotic effects are exerted.

p14 expression differences in ovarian benign, borderline and malignant epithelial tumors

BACKGROUND

Abnormalities in tumor suppressors p14, p16 and p53 are reported in several human cancers. In ovarian epithelial carcinogenesis, p16 and p53 show higher immunohistochemical staining frequencies in malignant tumors and are associated with poor prognoses. p14 was only analyzed in carcinomas, with conflicting results. There are no reports on its expression in benign and borderline tumors. This study aims to determine p14, p16 and p53 expression frequencies in ovarian benign, borderline and malignant tumors and their associations with clinical parameters.

METHODS

A cross-sectional study utilizing immunohistochemistry was performed on paraffin-embedded ovarian epithelial tumor samples. Clinical data were collected from medical records. Fisher's exact test and the Bonferroni correction were performed for frequency associations. Survival comparisons utilized Kaplan-Meier and log rank testing. Associations were considered significant when p < 0.05.

RESULTS

p14 absent expression was associated with malignant tumors (60 % positive) (p = 0.000), while 93 % and 94 % of benign and borderline tumors, respectively, were positive. p16 was positive in 94.6 % of carcinomas, 75 % of borderline and 45.7 % of benign tumors (p = 0.000). p53 negative staining was associated with benign tumors (2.9 % positive) (p = 0.016) but no difference was observed between borderline (16.7 %) and malignant tumors (29.7 %) (p = 0.560). No associations were found between expression rates, disease-free survival times or clinical variables. Carcinoma subtypes showed no difference in expression.

CONCLUSIONS

This is the first description of p14 expression in benign and borderline tumors. It remains stable in benign and borderline tumors, while carcinomas show a significant absence of staining. This may indicate that p14 abnormalities occur later in carcinogenesis. p16 and p53 frequencies increase from benign to borderline and malignant tumors, similarly to previous reports, possibly reflecting the accumulation of inactive mutant protein. The small sample size may have prevented statistically significant survival analyses and clinical correlations. Future studies should investigate genetic abnormalities in p14 coding sequences and include all types of ovarian epithelial tumors. Bigger sample sizes may be needed for significant associations.

The thyroid hormone-αvβ3 integrin axis in ovarian cancer: regulation of gene transcription and MAPK-dependent proliferation

Ovarian carcinoma is the fifth common cause of cancer death in women, despite advanced therapeutic approaches. αvβ3 integrin, a plasma membrane receptor, binds thyroid hormones (L-thyroxine, T4; 3,5,3'-triiodo-L-thyronine, T3) and is overexpressed in ovarian cancer. We have demonstrated selective binding of fluorescently labeled hormones to αvβ3-positive ovarian cancer cells but not to integrin-negative cells. Physiologically relevant T3 (1 nM) and T4 (100 nM) concentrations in OVCAR-3 (high αvβ3) and A2780 (low αvβ3) cells promoted αv and β3 transcription in association with basal integrin levels. This transcription was effectively blocked by RGD (Arg-Gly-Asp) peptide and neutralizing αvβ3 antibodies, excluding T3-induced β3 messenger RNA, suggesting subspecialization of T3 and T4 binding to the integrin receptor pocket. We have provided support for extracellular regulated kinase (ERK)-mediated transcriptional regulation of the αv monomer by T3 and of β3 monomer by both hormones and documented a rapid (30-120 min) and dose-dependent (0.1-1000 nM) ERK activation. OVCAR-3 cells and αvβ3-deficient HEK293 cells treated with αvβ3 blockers confirmed the requirement for an intact thyroid hormone-integrin interaction in ERK activation. In addition, novel data indicated that T4, but not T3, controls integrin's outside-in signaling by phosphorylating tyrosine 759 in the β3 subunit. Both hormones induced cell proliferation (cell counts), survival (Annexin-PI), viability (WST-1) and significantly reduced the expression of genes that inhibit cell cycle (p21, p16), promote mitochondrial apoptosis (Nix, PUMA) and tumor suppression (GDF-15, IGFBP-6), particularly in cells with high integrin expression. At last, we have confirmed that hypothyroid environment attenuated ovarian cancer growth using a novel experimental platform that exploited paired euthyroid and severe hypothyroid serum samples from human subjects. To conclude, our data define a critical role for thyroid hormones as potent αvβ3-ligands, driving ovarian cancer cell proliferation and suggest that disruption of this axis may present a novel treatment strategy in this aggressive disease.

Methylation and Immunoexpression of p16(INK4a) Tumor Suppressor Gene in Primary Breast Cancer Tissue and Their Quantitative p16(INK4a) Hypermethylation in Plasma by Real-Time PCR

Background

The p16^INK4a gene methylation has been reported to be a major tumorigenic mechanism.

Methods

We evaluated the methylation status of the p16^INK4a genes in 231 invasive breast cancer and 90 intraductal carcinoma specimens using a methylation-specific polymerase chain reaction and p16 protein expression using immunohistochemistry. The quantity of cell-free methylated p16^INK4a DNA in the plasma samples of 200 patients with invasive breast cancer was also examined using a fluorescence-based real-time polymerase chain reaction assay.

Results

The frequencies of p16^INK4a methylation in invasive and intraductal tumors were 52.8% (122/231) and 57.8% (52/90), respectively. The p16 protein was overexpressed in 145 of the 231 invasive carcinomas (62.8%) and 63 of the 90 intraductal carcinomas (70%). High p16 expression in invasive carcinomas correlated significantly with a high histologic grade, a negative estrogen receptor and progesterone receptor status, p53 immunoreactivity and high Ki-67 expression with immunohistochemistry. In addition, the methylation index of p16^INK4a was significantly higher in the cancer patients than the normal controls (p<0.001).

Conclusions

High p16 immunoreactivity correlated with a loss of differentiation in breast carcinomas and high frequency of p16^INK4a promoter methylation in both invasive and intraductal carcinomas, suggesting it may be involved in the pathogenesis of breast cancer.

Molecular Pathology of Ovarian Carcinomas

This content presents a review of molecular pathology of ovarian cancer. The authors present key molecular features for high-grade and low-grade serous carcinomas, endometrioid carcinomas, clear cell carcinomas, and mucinous carcinomas. Cell lineage, mutation and gene expression, pathway alterations, risk factors, prognostic markers, and treatment targets are discussed.

Modest effect of p53, EGFR and HER-2/neu on prognosis in epithelial ovarian cancer: a meta-analysis

BACKGROUND

P53, EGFR and HER-2/neu are the most frequently studied molecular biological parameters in epithelial ovarian cancer, but their prognostic impact is still unequivocal. We performed a meta-analysis to more precisely estimate their prognostic significance.

METHODS

Published studies that investigated the association between p53, EGFR and HER-2/neu status and survival were identified. Meta-analysis was performed using a DerSimonian-Laird model. Publication bias was investigated using funnel plots and sources of heterogeneity were identified using meta-regression analysis.

RESULTS

A total of 62 studies were included for p53, 15 for EGFR and 20 for HER-2/neu. P53, EGFR and HER-2/neu status had a modest effect on overall survival (pooled HR 1.47, 95% CI 1.33-1.61 for p53; HR 1.65, 95% CI 1.25-2.19 for EGFR and HR 1.67, 95% CI 1.34-2.08 for HER-2/neu). Meta-regression analysis for p53 showed that FIGO stage distribution influenced study outcome. For EGFR and HER-2/neu, considerable publication bias was present.

CONCLUSIONS

Although p53, EGFR and HER-2/neu status modestly influences survival, these markers are, by themselves, unlikely to be useful as prognostic markers in clinical practice. Our study highlights the need for well-defined, prospective clinical trials and more complete reporting of results of prognostic factor studies.

Serum and tissue biomarkers as predictive and prognostic variables in epithelial ovarian cancer

Tumour stage, residual disease after initial surgery, histological type and tumour grade are the most important clinical-pathological factors related to the clinical outcome of patients with epithelial ovarian cancer. In the last years, several investigations have assessed different biological variables in sera and in tissue samples from patients with this malignancy in order to detect biomarkers able to reflect either the response to chemotherapy or survival. The present paper reviewed the literature data about the predictive or prognostic relevance of serum CA 125, soluble cytokeratin fragments, serum human kallikreins, serum cytokines, serum vascular endothelial growth factor and plasma d-dimer as well as of tissue expression of cell cycle- and apoptosis-regulatory proteins, human telomerase reverse transcriptase, membrane tyrosine kinase receptors and matrix metalloproteinases. A next future microarray technology will hopefully offer interesting perspectives of translational research for the identification of novel predictive and prognostic biomarkers for epithelial ovarian cancer.

Alteration of cell-cycle regulation in epithelial ovarian cancer

In spite of the clinical importance of epithelial ovarian cancer (EOC), little is known about the pathobiology of its precursor lesions and progression. Regulatory mechanisms of the cell cycle are mainly composed of cyclins, cyclin-dependent kinases (CDK), and CDK inhibitors. Alteration of these mechanisms results in uncontrolled cell proliferation, which is a distinctive feature of human cancers. This review describes the current state of knowledge about the alterations of cell-cycle regulations in the context of p16-cyclin D1-CDK4/6-pRb pathway, p21-p27-cyclin E-CDK2 pathway, p14-MDM2-p53 pathway, and ATM-Chk2-CDC25 pathway, respectively. Recent evidence suggests that ovarian cancer is a heterogenous group of neoplasms with several different histologic types, each with its own underlying molecular genetic mechanism. Therefore, expression of cell cycle regulatory proteins should be tested separately according to each histologic type. In serous ovarian carcinoma, high expression of p16, p53, and p27 and low expression of p21 and cyclin E were shown. In addition, this review focuses on the prognostic significance of cell cycle-regulating proteins in EOC. However, it is difficult to compare the results from different groups due to diverse methodologies and interpretations. Accordingly, researchers should establish standardized criteria for the interpretation of immunohistochemical results.

Epithelial ovarian cancer: the role of cell cycle genes in the different histotypes

Cancer is frequently considered to be a disease of the cell cycle; alterations in different families of cell cycle regulators cooperate in tumor development. Molecular analysis of human tumors has shown that cell cycle regulators are frequently mutated in human neoplasms, which underscores how important the maintenance of cell cycle commitment is in the prevention of human cancer. The regulatory pathways controlling cell cycle phases include several oncogenes and tumor suppressor genes which display a range of abnormalities with potential usefulness as markers of evolution or treatment response in epithelial ovarian cancer. This review summarizes the current knowledge about these aberrations in malignant tumors of the ovary. We sought to focus our attention on the genes involved in the development of tumors arising from the ovarian epithelium, which are the most common types of ovarian malignancies.

Human papilloma virus (HPV) status, p16INK4a, and p53 overexpression in epithelial malignant and borderline ovarian neoplasms

This investigation is the first to evaluate simultaneously human papilloma virus (HPV) status, p16(INK4a), and p53 immunoreactivity in epithelial ovarian neoplasms. The results were analyzed and correlated with histological type, histological grade, and survival of patients. Subtypes considered are papillary serous and mucinous. Polymerase chain reaction (PCR) analysis, performed in our previous study, had already demonstrated a small number of HPV-positive epithelial ovarian neoplasms. No significant correlation was found between the presence of HPV DNA and subtypes of ovarian neoplasms; thus, HPV cannot be considered responsible for epithelial ovarian neoplasm. Since p16 immunoreactivity was present in many other HPV-negative cases of epithelial ovarian neoplasms, this study suggests that p16 overexpression in some neoplasms of the female genital tract is not related to HPV carcinogenesis. A higher p53 expression rate observed between borderline and malignant serous tumors and between serous and mucinous neoplasms can confirm a recent dualistic model of ovarian carcinogenesis. According to this theory, low-grade serous carcinomas (serous intraepithelial carcinomas, serous borderline neoplasm, and ovarian mucinous neoplasms) (type I tumors) develop from mutations of KAS and BRAF, while high-grade serous carcinomas (type II tumors) develop from mutation of p53. In malignant neoplasms, for univariate analysis, patient survival seems to be related to p53, strong and diffuse p16 overexpression, and the stage of development of neoplasms at the diagnosis. In multinomial logistic regression, used to evaluate the role of staging, grading, p16 and p53 immunopositivity as predictor variables of unfavorable outcome of the disease, only p16 positivity was significantly related to the poor prognosis of the cancer.

Immunohistochemical similarities between pancreatic mucinous cystic tumor and ovarian mucinous cystic tumor

OBJECTIVE

Pancreatic mucinous cystic tumor (MCT(P)) and ovarian mucinous cystic tumor (MCT(O)) show common features. However, there are few studies showing a comparison of both types of tumor. We immunohistochemically studied both types of tumor to clarify their characteristics.

METHODS

Eight patients with MCT(P) and 21 patients with MCT(O) were examined. The tumors were immunohistochemically examined using antibodies against female sex hormone receptors (estrogen receptor, progesterone receptor, and alpha-inhibin), pancreatobiliary tissue markers (carbohydrate antigen 19-9 and DUPAN2) and cell cycle regulators (p27kip1 and phosphorylated retinoblastoma). Samples from 7 female patients with invasive pancreatic ductal carcinoma (DC), 8 female patients with normal pancreatic tissue, and 10 patients with normal ovarian tissue were also examined.

RESULTS

In the tumor epithelial cells, the expressions of DUPAN2 and p27/kip1 were similar between MCT(P) (38% and 88%, respectively) and MCT(O) (14% and 76%, respectively), but significantly different between both tumors and DC (100% and 0%). In the stromal cells, the expressions of estrogen receptor, progesterone receptor, alpha-inhibin, and p27/kip1 were similar between MCT(P) (63%, 75%, 50%, and 63%, respectively) and MCT(O) (57%, 71%, 81%, and 57%, respectively), but significantly different between both tumors and DC (0%, 0%, 0%, and 0%, respectively).

CONCLUSIONS

MCT(P) and MCT(O) have several immunohistochemical similarities and are significantly different from DC. The female sex hormone system may play a major role in the development of both MCT(P) and MCT(O). A frequent p27/kip1 expression level was associated with nonaggressive progression of both tumors.

The clinical importance of Ki-67, p16, p14, and p57 expression in patients with advanced ovarian carcinoma

The present study addressed the impact of p14, p16, p57, and Ki-67 in a large cohort of uniformly treated patients with stage III ovarian cancer in relation to other clinicopathologic variables and prognosis. We immunohistochemically studied 171 primary tumors from previously untreated patients with advanced ovarian carcinomas for expression of Ki-67, p16, p14, and p57. High protein levels of Ki-67 (>10% positive nuclei) were found in 144 cases (84%), p16 (>50% positive nuclei) in 53 cases (31%), p57 (>10% positive nuclei) in 41 cases (24%), and p14 (any positive nuclei) in 19 cases (11%). A correlation between high Ki-67 expression and presence of residual disease after primary surgery (P = 0.019), ascites (P = 0.006), higher International Federation of Gynecology and Obstetrics substage (P < 0.001), poor differentiation (P < 0.001), and higher Silverberg histopathologic grade (P < 0.0001) was seen. High expression of p16 correlated to poor differentiation (P = 0.033) and higher Silverberg histopathologic grade (P = 0.018). In univariate analysis, high expression of Ki-67 (P = 0.0001) and p16 (P = 0.005) was associated with poor survival. However, in multivariate analysis, only high expression of Ki-67 was significantly associated with shorter survival (P = 0.025). No correlations were seen between expression of p14 and p57 and clinicopathologic parameters. None of the factors studied was able to predict response to chemotherapy. Our results showed that Ki-67 represents an independent prognostic predictor in stage III ovarian cancer. We did not find p16, p14, and p57 to be useful as prognostic markers.

Genetic background of esophageal squamous cell carcinoma

A nyelőcsőrák a kilencedik leggyakoribb rosszindulatú daganat. Több mint 90%-ban előrehaladott állapotban kerül felismerésre. A sebészi beavatkozás, a kemo-, illetve radioterápia lehetőségei korlátozottak. Napjainkban a génterápia került az érdeklődés előterébe. A szerzők a nyelőcsőlaphámrák genetikai és molekuláris hátterét és a génterápiával elért kezdeti tapasztalatokat tekintik át. Ismertetik a komplementer nukleinsavak (antisense terápia), a génpótlás, a kis interferáló RNS-k alkalmazásának lehetőségeit.

p16 expression in primary ovarian mucinous and endometrioid tumors and metastatic adenocarcinomas in the ovary: utility for identification of metastatic HPV-related endocervical adenocarcinomas

Distinction of primary ovarian epithelial tumors from metastatic adenocarcinomas is challenging for tumors exhibiting mucinous, endometrioid, or mixed endometrioid/mucinous differentiation. Metastatic carcinomas with these types of differentiation can be derived from several sites, including the gastrointestinal tract and the uterus. Most endocervical adenocarcinomas exhibit mucinous and/or endometrioid differentiation; they infrequently metastasize to the ovaries but may simulate primary ovarian tumors [both atypical proliferative (borderline) and carcinoma]. Most are high-risk human papillomavirus (HPV)-related and demonstrate diffuse p16 over-expression due to complex molecular mechanisms by which high-risk HPV transforming proteins interact with cell cycle regulatory proteins. The performance of this expression pattern for identifying metastatic endocervical adenocarcinomas in the ovaries among primary ovarian tumors and other metastatic adenocarcinomas having mucinous and/or endometrioid/endometrioidlike differentiation has not been evaluated. Immunohistochemical expression of p16 was assessed in 195 tumors, including 98 primary ovarian tumors (51 mucinous, 47 endometrioid, and 4 mixed mucinous-endometrioid tumors), 93 metastatic adenocarcinomas of known primary sites (colorectum: 34, endocervix: 19, pancreaticobiliary tract: 17, appendix: 7, stomach: 5), 11 metastatic adenocarcinomas of unknown origin (7 established as noncervical), and 4 adenocarcinomas of uncertain (primary ovarian vs. metastatic) origin. The HPV status of the endocervical adenocarcinomas was determined by in situ hybridization and polymerase chain reaction (when in situ hybridization was negative). Expression was assessed based on the percentage of moderately to strongly positive cells, estimated to the nearest 10%. Mean and median expression values for HPV-positive endocervical adenocarcinomas (99%, 100%; range 90% to 100%) were substantially higher than those for primary ovarian mucinous (5%, 0%; range 0% to 70%) and endometrioid (20%, 10%; range 0% to 100%) tumors, HPV-unrelated endocervical adenocarcinomas (0%, 0%; range 0% to 60%), metastatic adenocarcinomas of unknown origin (11%, 0%; range 0% to 30%), and adenocarcinomas of uncertain (primary ovarian vs. metastatic) origin (40%, 35%; range 0% to 90%); only the 15 HPV-positive endocervical adenocarcinomas and 6 other tumors had values of 80% or greater. Diffuse (>75% positive tumor cells) moderate to strong p16 expression is a sensitive (100%) and specific (97%) marker for identifying HPV-related endocervical adenocarcinomas metastatic to the ovary among the primary ovarian tumors and metastatic adenocarcinomas from other sites that are in the differential diagnosis of ovarian tumors having mucinous and/or endometrioid/endometrioidlike differentiation. p16 is useful as part of a panel of immunohistochemical markers for distinguishing primary ovarian tumors from metastases and, when diffusely positive, can suggest the cervix as a potential primary site for metastatic adenocarcinomas of unknown origin.

Induction of p16INK4A mediated by beta-catenin in a TCF4-independent manner: implications for alterations in p16INK4A and pRb expression during trans-differentiation of endometrial carcinoma cells

Excessive beta-catenin is considered to contribute to tumor progression by inducing transcription of cell cycle-related genes such as cyclin D1 and c-myc. In contrast, our recent studies demonstrated that beta-catenin could inhibit cell proliferation through activation of p14(ARF)/p53/p21(WAF1) pathway during trans-differentiation toward morular phenotype of endometrial carcinoma (Em Ca) cells. Here, we focused on associations with alterations in p16(INK4A) and pRb expression during this process. In clinical cases, p16(INK4A) immunoreactivity was found to frequently overlap with nuclear beta-catenin accumulation in small-sized morules and surrounding glandular carcinomas (Sur-Ca), demonstrating a significant positive correlation (r = 0.447, p < 0.0001) overall, while the immunoreactions showed stepwise decrease in enlarged morules, despite persistent accumulation of beta-catenin and p21(WAF1) in nuclei. Immunoreactivity for both total pRb and its phosphorylated form was apparently decreased in all morules as compared to Sur-Ca lesions, with a significantly positive correlation. In cell lines, transcriptional activation of p16(INK) (4A) promoter by active form beta-catenin, as well as p21(WAF1), occurred through the region from -385 to -280 bp relative to the translation start site, in a TCF4-independent manner. Moreover, cell proliferation was accompanied with phosphorylation of pRb and increased p16(INK4A) expression, while its inhibition by serum starvation caused decreased expression of total pRb but not p16(INK4A), resulting in high relative amounts of the latter. These findings indicate that induction of p16(INK4A) mediated by nuclear beta-catenin and p21(WAF1), along with loss of pRb expression, may be important for initial steps during trans-differentiation of Em Ca cells. In addition, its down-regulation is associated with progression of lesions.

Ovarian clear cell adenocarcinoma: a continuing enigma

Ovarian clear cell adenocarcinomas (OCCAs) account for <5% of all ovarian malignancies. Compared to other epithelial ovarian cancer (EOC) subtypes, when at an advanced stage, they are associated with a poorer prognosis and are relatively resistant to conventional platinum-based chemotherapy. By contrast, early-stage clear cell ovarian cancer carries a relatively good prognosis. Hence, there is a need to improve our understanding of its pathobiology in order to optimise currently available treatments and develop new therapeutic strategies. This review summarises the currently available literature regarding the pathogenesis of OCCA, its molecular genetic features and postulated molecular mechanisms that underlie its chemoresistant phenotype. Marked similarities with clear cell carcinomas of the kidney and endometrium have been noted by some investigators, raising interesting possibilities regarding novel therapeutic approaches. Unfortunately, most studies on OCCA have hitherto been hampered by insufficient sample sizes, leaving many key issues unresolved. It is envisaged that in the future, high-resolution genomic and gene-expression microarray studies incorporating larger sample sizes will lead to the characterisation of the key molecular players in OCCA biology, which may potentially lead to the identification of novel targets for therapeutic development.

Cyclin-dependant kinase inhibitors CIP1 (p21) and KIP1 (p27) in ovarian cancer

PURPOSE

Deregulation of the cell cycle is one of the important prerequisites for cancer development. p21 and p27 are both universal inhibitors of cyclin-dependent kinases and can therefore influence cell cycle or tumor progression. The aim of this study was to determine the influence of p21 and p27 expression on survival and chemotherapy response.

METHODS

165 patients with ovarian cancer have been examined for p21 and p27 expression by immunohistochemistry on formalin-fixed, paraffin-embedded tissue using the monoclonal primary antibody WAF1 (Oncogene Science) and KIP1 (Transduction Laboratories).

RESULTS

High p21 expression (>50%) correlates only with early tumor stage (P=0.04). There was no correlation found between p21 and p27 expression. Patients with high p27 expression (>25%) had a longer DFS (disease free survival) in both univariate and multivariate analysis (P=0.05 and P=0.043) than patients with low p27 expression. A longer overall survival (OS) could only be proven for the group of high p27 expression in univariate analysis (P=0.03).

CONCLUSION

p27 is an independent prognostic factor for ovarian cancer for DFS though this was not true for OS.

Resveratrol modulates gene expression associated with apoptosis, proliferation and cell cycle in cells with mutated human c-Ha-Ras, but does not alter c-Ha-Ras mRNA or protein expression

An accumulating body of evidence suggests that resveratrol can inhibit carcinogenesis through antiproliferative and apoptotic effects. One proposed mechanism for this is the modulation of genes, for example, Ras and p53, frequently associated with human cancer. To test the effect of resveratrol on gene expression, we used the WR-21 cell line because it contains a mutated human c-Ha-ras gene. Cells at > or =70% confluency were incubated with media alone or with increasing concentrations of trans-resveratrol (0.1-1000 microM) for 24 h. Resveratrol (30-100 microM) decreased cellular proliferation by 80% (bromodeoxyuridine incorporation) and increased apoptosis by 60% (TUNEL). Cells were then treated with media alone or with 50-microM resveratrol for 24 h. RNA was isolated for nylon-based macroarray analyses and protein for immunoblotting. Resveratrol increased (+) and decreased (-) gene expression associated with apoptosis (Birc5+, Cash+, Mcl-1+, Mdm2+, Rpa-like+), cellular proliferation (Ctsd+, Mdm2+, Egr1+, ODC+) and cell cycle (cyclin D+, cyclin g+, Gadd45a-, Mad2l-, Mdm2+). Resveratrol consistently increased by > or =6-fold Mdm2 expression and other downstream p53 effectors, but not p53 itself at 24 h. Subsequent cell cycle analysis indicated a significant accumulation of cells in G2/M, and a decrease in G1/G0 suggesting a G2/M blockade. Further RT-PCR and Western blot analyses indicated no differential changes in Ras mRNA expression or p21(ras) protein levels, respectively. These results suggest that resveratrol potently inhibits cellular proliferation, increases apoptosis, alters cell cycle dynamics and modulates associated gene expression. Furthermore, these effects appear mediated, in part, by p53 without direct modulation of mutant c-Ha-ras expression.

Cell cycle genes in ovarian cancer: steps toward earlier diagnosis and novel therapies

Human malignant tumors are characterized by abnormal proliferation resulting from alterations in cell cycle-regulatory mechanisms. The regulatory pathways controlling cell cycle phases include several oncogenes and tumor suppressor genes that display a range of abnormalities with potential usefulness as markers of evolution or treatment response in ovarian cancer. This review summarizes the current knowledge about these aberrations in malignant tumors of the ovary. We sought to divide cell cycle-regulatory genes into four subgroups on the basis of their predominant role in a specific phase or during the transition between two phases of the cell cycle.

p16 expression in sentinel nodes with metastatic breast carcinoma: evaluation of its role in developing triaging strategies for axillary node dissection and a marker of poor prognosis

Not all patients with metastatic breast carcinoma (MBC) in a sentinel lymph node (SLN) have metastasis in additional axillary nodes (ANs). A biological marker that can predict this occurrence may be beneficial in triaging only appropriate patients for AN dissection (AND). Our aim was to study p16 expression in SLNs and to determine whether it is a predictor of metastases to additional ANs and a marker of poor prognosis. We correlated p16 expression in SLNs and ANs of 54 patients with MBC with clinicopathologic features and the nodal proliferative index (PI). We sequenced p16 from DNA in 7 cases. We found that 35 of 54 cases (65%) had p16-positive tumor cells. Nine of 17 (53%) cases in which both SLN and AND were done had MBC in additional ANs. The SLNs of 8 of 9 cases (89%) were p16 positive (73% positive predictive value). Eight of 17 (47%) cases had no metastases in ANs even though their SLNs had metastases. The SLNs of 5 of 8 (62.5%) of these cases were p16 negative (83% negative predictive value). Ductal MBCs were p16 positive in 27 of 37 cases (73%). Carcinomas with a lobular component were p16 negative in 9 of 11 cases (82%). Nine of 12 (75%) p16-negative ductal carcinomas were estrogen receptor (ER) positive. Some 75% of T2 and T3 tumors were p16 positive, compared with 50% of T1 tumors. The highest PI (defined as > or =50%) was seen in p16-positive SLNs (5 of 6 cases). The p16 DNA sequence was normal, and no mutations were found. Our findings indicate that p16 expression in SLNs with MBC predicts (1) increased likelihood of metastasis in additional ANS, and its expression along with other markers and clinicopathologic parameters may serve as an indicator for proceeding to a formal AND; (2) poor prognosis and is associated with larger primary tumors with a high nodal PI and ER-negative status; and (3) histological subtypes. Gene mutations were not responsible for the expression of p16 in our cases.

p16INK4a and p21Waf1/Cip1 expression correlates with clinical outcome in vulvar carcinomas

OBJECTIVE

Aberrant expression of the cell cycle kinase inhibitors p16, p21, and p27 has been associated with poor prognosis in a variety of human malignancies. Little is known, however, about their clinical impact in vulvar carcinoma patients. Thus, we analyzed a larger series of vulvar squamous cell carcinomas and compared the results with clinical outcome.

METHODS

A total of 224 vulvar squamous cell carcinomas were immunohistochemically investigated for expression of p16, p21, and p27 using the biotin-streptavidin-peroxidase method and the OptiMax Plus automated cell staining system.

RESULTS

High p16 (> or =5%) positive nuclear immunostaining was found in 69 (31%) cases, high p21 (any staining) protein levels was detected in 95 (42%) cases, and low p27 (< or =50% positive nuclei) staining was seen in 170 (76%) cases. High expression of p16 was related to lower patient age and low expression of p53. High expression of p16 indicated a better prognosis in the multivariate analysis (RR = 0.5, 95% CI = 0.2-1.0) and less risk of developing lymph node metastasis (OR = 0.3, 95% CI = 0.2-0.7). High level of p21 was significantly associated with shorter survival in patients staged FIGO I and II (RR = 3.4, 95% CI = 1.3-9.3). We found no significant correlation between the expression of p27 and any of the clinicopathological variables.

CONCLUSIONS

Our study indicates a prognostic relevance for p16 and p21 immunoreactivity. Low level of p16 protein and high level of p21 protein were associated with a shorter disease-related survival. We did not find p27 protein expression to be useful as a prognostic indicator in vulvar carcinoma patients.

P16INK4A positivity in benign, premalignant and malignant cervical glandular lesions: a potential diagnostic problem

A wide array of immunohistochemical markers have been evaluated with respect to their specificity in staining dysplastic cervical cells in cervical biopsies and cervical cytological smears. However, there is still a significant demand for better biomarkers to identify neoplastic cervical glandular and squamous epithelial cells precisely. The CDKN2A gene, located on chromosome 9p21, encodes the tumour suppressor protein, p16INK4A, which decelerates the cell cycle by inactivating CDK4 and CDK6. The aim of this study was to compare and contrast the expression pattern of p16INK4A in benign and neoplastic glandular lesions and tubo-endometrioid metaplasia. All cases in each category displayed some p16INK4A expression. Adenocarcinoma and in situ cases showed a combination of intense nuclear and cytoplasmic staining. It was observed that all cases of tubo-endometrioid metaplasia showed occasional nuclear positivity and definite cytoplasmic staining. These findings may have important implications for the potential utility of p16INK4A as a biomarker for glandular dysplastic lesions. While p16INK4A has been demonstrated to be an excellent marker of cervical dysplasia in squamous neoplastic lesions of the cervix, it has potential pitfalls in cervical glandular lesions that may limit the utility of this biomarker in resolving the nature of suspicious glandular lesions, particularly in cytopathology.

Expression of Tumor Suppressor Gene Product p14ARF in Endometrioid Adenocarcinoma of the Uterine Corpus

p14 activates p53 by inhibiting MDM2 expression and arrests the cell cycle in G1 and G2/M. Abnormal p14 expression has been reported in various human cancers. This study investigated p14 expression in endometrioid adenocarcinoma of the uterine corpus in an attempt to clarify its correlation with other cell cycle-regulators and clinicopathologic parameters. The specimen studied consisted of 124 endometrioid adenocarcinomas, 20 normal endometria, and 20 endometrial hyperplasias. Immunohistochemical staining of formalin-fixed and paraffin-embedded tissues was performed using a Catalyzed Signal Amplification System. Cells with >5% positive staining were classified as positive for p14. A staining score of 1 was adopted when the percentage of positive nuclei was <5%, a score of 2 when it was 5 to 50%, and a score of 3 when it was >50%. In normal endometrium, the frequency of positive staining in the proliferative phase and secretory phase was 50% (4/8) and 58.3% (7/12), with staining scores of 1.8+/-0.9 and 1.6+/-0.5, respectively. The frequency of staining in simple hyperplasia (SH), complex hyperplasia (CH), and complex atypical hyperplasia (CAH) was 88.9% (8/9), 25% (1/4), and 42.9% (3/7), respectively; the staining scores were 1.9+/-0.3, 1.3+/-0.5, and 1.4+/-0.5, respectively. Among endometrioid adenocarcinomas, the frequency of staining of well-differentiated (G1), moderately differentiated (G2), and poorly differentiated (G3) adenocarcinomas was 69% (49/71), 64% (16/25), and 42.9% (12/28) respectively, with staining scores of 2.1+/-0.8, 2+/-0.9, and 1.8+/-1, respectively. Thus expression levels of p14 were higher in G1 tumors than in normal endometria or endometrial hyperplasias, and the frequency of its staining in endometrioid carcinomas was inversely correlated with histologic grade. The staining score for endometrioid adenocarcinomas also was inversely correlated with the labeling index (LI) of Ki-67, but not with that of cyclin A, cyclin D1, cyclin E, cdk2, p27, p53, or other clinicopathologic parameters. In conclusion, p14 expression correlated with histologic grade and Ki-67, but not other prognostic factors in endometrioid adenocarcinoma. Long-term follow-up studies are needed to analyze the significance of p14 expression in these tumors.

Neocarzinostatin induces an effective p53-dependent response in human papillomavirus-positive cervical cancer cells

Human papillomavirus (HPV) E6 viral oncoprotein plays an important role during cervical carcinogenesis. This oncoprotein binds the tumor suppressor protein p53, leading to its degradation via the ubiquitin-proteasome pathway. Therefore, it is generally assumed that in HPV-positive cancer cells p53 function is completely abolished. Nevertheless, recent findings suggest that p53 activity can be recovered in cells expressing endogenous E6 protein. To investigate whether p53-dependent functions controlling genome integrity, cell proliferation, and apoptosis can be reactivated in cervical cancer cells, we examined the capacity of HeLa, INBL, CaSki, C33A, and ViBo cell lines to respond to neocarzinostatin (NCS), a natural product which induces single- and double-strand breaks in DNA. We found that NCS treatment inhibits cellular proliferation through G2 cell cycle arrest and apoptosis induction. This effect was preceded by nuclear accumulation of p53 protein and by an increase of p21 transcripts. Although apoptosis was blocked in ViBo cells (HPV-negative), nuclear accumulation of transcriptionally active p53 and inhibition of cell proliferation are observed after NCS treatment. These results suggest that HPV-positive cervical cancer cells are capable of responding efficiently to DNA damage provoked by NCS treatment through a p53-dependent pathway in spite of the presence of E6 protein.

P21WAF1, P27KIP1, TP53 and C-MYC analysis in 204 ovarian carcinomas treated with platinum-based regimens

BACKGROUND

The prognostic and predictive value of cell cycle regulatory proteins in ovarian cancer has not been established. We evaluated the clinical and biological significance of P21(WAF1), P27(KIP1), C-MYC, TP53 and Ki67 expressions in ovarian cancer patients.

MATERIALS AND METHODS

Immunohistochemical analysis was performed on 204 ovarian carcinomas of International Federation of Gynecology and Obstetrics (FIGO) stage IIB to IV treated with platinum-based chemotherapy. Multivariate analysis with Cox and logistic regression models was performed in the whole group, and in the TP53-negative and TP53-positive subgroups.

RESULTS

High P21(WAF1) labeling index (LI) was an independent positive predictor of platinum-sensitive response (P = 0.02). Overall survival was positively influenced by P21(WAF1) LI (P = 0.02) or by P21(WAF1) plus P27(KIP1) LI (P = 0.004) in the TP53-negative group only. Ki67 LI showed borderline association with disease-free survival (P = 0.05). Growth fraction was negatively associated with P21(WAF1) and P27(KIP1) indices in the TP53-negative group (P = 0.023 and 0.008, respectively), and these associations were borderline or lost in the TP53-positive group. Endometrioid and clear cell carcinomas differed from other carcinomas by having a low incidence of TP53 accumulation, a high incidence of C-MYC overexpression (70%) and a low median Ki67 LI (all with P <0.001).

CONCLUSIONS

We have shown an independent predictive value of P21(WAF1) LI in ovarian carcinoma patients. The prognostic value of P21(WAF1) and P21(WAF1) plus P27(KIP1) LI was determined by TP53 status. A high frequency of C-MYC overexpression in endometrioid and clear cell carcinomas may suggest its role in the development of these tumor types.

Cytogenetic alterations in ovarian clear cell carcinoma detected by comparative genomic hybridisation

Ovarian clear cell carcinoma (OCCC) accounts for a small but significant proportion of all ovarian cancers and is a distinct clinical and pathological entity. It tends to be associated with poorer response rates to chemotherapy and with a worse prognosis. Little is known about possible underlying genetic changes. DNA extracted from paraffin-embedded samples of 18 pure OCCC cases was analysed for genetic imbalances using comparative genomic hybridisation (CGH). All of the 18 cases showed genomic alterations. The mean number of alterations detected by CGH was 6 (range 1-15) indicating a moderate level of genetic instability. Chromosome deletions were more common than amplifications. The most prominent change involved chromosome 9 deletions in 10 cases (55%). This correlates with changes seen in other epithelial ovarian cancers. This deletion was confirmed using microsatellite markers to assess loss of heterozygosity (LOH) at four separate loci on chromosome 9. The most distinct region of loss detected was around the IFNA marker at 9p21 with 41% (11 out of 27 cases) LOH. Other frequent deletions involved 1p (five out of 18; 28%); 11q (four out of 18; 22%) and 16 (five out of 18; 28%). Amplification was most common at chromosome 3 (six out of 18; 33%); 13q (four out of 18; 22%) and 15 (three out of 18; 17%). No high-level amplifications were identified. These features may serve as useful prognostic indicators in the management of OCCC.

p53 gene therapy for esophageal cancer

Despite improvement of surgical treatment and application of multimodality therapies to advanced esophageal cancer, the prognosis is extremely poor for patients with unresectable tumors. Based on the genetic background of esophageal cancer, we have developed various gene therapy strategies against human esophageal cancer. In this article, we review molecular events of esophageal cancer and p53 gene therapy approaches for its treatment. First, we analyzed p53 genetic alterations and angiogenesis in esophageal cancer. Second, we tested a p53 recombinant adenoviral vector (Ad5CMV-p53). Significant growth suppression was observed following infection with Ad5CMV-p53 in human esophageal cancer cell lines. This observation suggests that Ad5CMV-p53 may be a potentially effective therapeutic agent for locally advanced esophageal cancer. Promising avenues for investigation include double gene therapy and adjuvant use of gene therapy with radiation therapy. Third, based on recent reports of clinical trials of p53 gene therapy for lung cancer and head and neck cancer, we developed a clinical protocol for p53 gene therapy for unresectable advanced esophageal cancer. This clinical trial was planned to evaluate vector tolerability and efficacy. Up to December 1, 2001, four patients were enrolled in this phase I/II trial. No serious adverse events related to Ad5CMV-p53 have occurred so far in these patients, and the trial has been safely conducted.