Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0476089 (endometrial cancer)
 11,379 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The p16INK4aa (CDKN2) tumor suppressor gene is altered in several tumor types, but the frequency and mechanism of inactivation are largely unknown for endometrial carcinomas. We therefore wanted to assess the pattern and prognostic impact of p16 protein expression and promoter region methylation in a population-based series of 316 endometrial carcinoma patients with long-term and complete follow-up. Nuclear staining of p16 protein was related to clinicopathological variables, tumor markers, patient survival, and the presence of promoter region methylation. Absent/minimal nuclear staining for p16 protein was found in 14% of the tumors. Methylation of the p16 promoter region was found in only one tumor (0.7%) in a subset of 138 cases studied. This tumor lacked nuclear p16 protein expression as well. Loss of nuclear p16 staining was significantly associated with increased age, high FIGO (International Federation of Gynecology and Obstetrics) stage, serous papillary or clear cell histological types, high histological grade, aneuploidy, low estradiol and progesterone receptor concentrations, high expression of Ki-67, high intratumor microvessel density, and strong nuclear p53 protein expression. The 5-year survival was 47% for patients with absent/minimal nuclear p16 expression (n = 39) compared with 81% for patients with moderate/high nuclear p16 expression (n = 247; P < 0.0001). In Cox proportional hazards regression analysis, nuclear p16 expression showed an independent prognostic impact in addition to FIGO stage, age, Ki-67 expression, and microvessel density, with an adjusted hazard ratio of 2.9 (95% confidence interval, 1.3-6.5). The other variables lost their prognostic impact when nuclear p16 staining was added to the Cox model. In conclusion, loss of nuclear p16 protein expression was associated with aggressive endometrial carcinomas and high proliferative activity (Ki-67) and was found to represent a strong and independent prognostic indicator. Methylation of the promoter region seems to be an uncommon mechanism of p16 inactivation in endometrial carcinoma.
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PMID:Loss of nuclear p16 protein expression is not associated with promoter methylation but defines a subgroup of aggressive endometrial carcinomas with poor prognosis. 1065 44

We analysed p16 gene alteration and p16, cyclin-dependent kinase 4 (CDK4), CDK6, cyclin D1, cyclin D2, cyclin D3 and retinoblastoma protein (pRb) expression in ten normal endometriums (PE), 18 endometrial hyperplasias (EH) and 35 endometrial cancers (EC). Two of ten PE (20%), nine of 18 EH (50.0%) and 29 of 35 EC (82.9%) exhibited p16 nuclear staining. p16 expression was significantly higher in EC than EH (P = 0.0119). In the six p16 (-) EC, one was considered to have reduced gene dosage consistent with possible homozygous deletion of the CDKN2 gene and three had methylation in 5'CpG island in the promoter region of the p16 gene, whereas none showed such reduced gene dosage and four had methylation in the nine p16 (-) EH. Strong CDK4 staining was observed in 12 of 35 EC (34.3%) and one of 18 EH (5.6%). The strong expression of CDK4 was higher in EC than in EH (P = 0.0399). The expression of CDK4 was higher in EH than PE (P = 0.0054). The abnormalities of p16-cyclin D/CDK-pRb pathway were detected in 18 of 35 EC (51.4%). In conclusion, the expression of p16 and CDK4 may be an early event in the neoplastic transformation of endometrial cancer.
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PMID:The role of p16-cyclin d/CDK-pRb pathway in the tumorigenesis of endometrioid-type endometrial carcinoma. 1068 82

Inactivating mutations in the PTEN tumor suppressor gene occur in approximately 30-50% of endometrial carcinomas. PTEN is a phosphatase that negatively regulates the phosphoinositide 3-kinase signaling pathway, including the downstream effector AKT. To evaluate the role of PTEN in endometrial growth regulation, we expressed wild-type or mutant PTEN in endometrial carcinoma cell lines. As expected, expression of exogenous PTEN decreased levels of activated AKT in all cell lines examined. However, PTEN induced a G(1) cell cycle arrest specifically in endometrial carcinoma cells that lack endogenous wild-type PTEN. Growth of cells containing wild-type PTEN was unaffected by exogenous PTEN expression. Growth arrest required a functional phosphatase domain but not the PDZ interaction motif of PTEN. Overall levels of CIP/KIP and INK4 family members, the known inhibitory regulators of the G(1) phase of the cell cycle, were unchanged. However, PTEN induced a specific reduction of cyclin D3 levels and an associated increase in the amount of the inhibitor p27(KIP1) complexed with CDK2. Enforced expression of cyclin D3 abrogated the PTEN-induced cell cycle arrest. Although PTEN signaling directly regulates p27(KIP1) levels in some settings, in endometrial carcinoma cells, PTEN expression indirectly regulated p27(KIP1) activity by modulating levels of cyclin D3. These data support multiple mechanisms of PTEN-induced cell cycle arrest.
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PMID:PTEN induces G(1) cell cycle arrest and decreases cyclin D3 levels in endometrial carcinoma cells. 1138 92

We analyzed the mechanism of estrogen receptor (ER) loss and status of the p53 pathway in 64 cases of endometrial cancer. 26.6% (17 of 64) of endometrial cancers lost ER. Methylation of the ER CpG island was significantly related to ER status (P = 0.0074). However, the methylation site of the ER CpG island differed between breast and endometrial cancers. The abnormal expression rate of p14ARF, MDM2, p53, and the p53 pathway were 7.8% (5 of 64), 32.8% (21 of 64), 25.0% (16 of 64) and 53.1% (34 of 64), respectively. There was no significant difference in the overexpression of MDM2 between p53-positive cases (43.8%: 7 of 16) and p53-negative cases (29.2%; 14 of 48) (P = 0.3595). Abnormal p53 was higher in grade 3 tumors (55.6%; 5 of 9) than in grade 1 and 2 tumors (20.0%; 11 of 55) (P = 0.0364). The abnormality of the p53 pathway was higher in grade 3 tumors (88.9%; 8 of 9) than in grade 1 and 2 tumors (47.3%; 26 of 55) (P = 0.0294). However, there was no significant difference in abnormal p53 pathway between ER-negative and ER-positive cases. In endometrial cancer, ER CpG island methylation was the important mechanism of ER loss. However, there was no significant relationship between the p53 pathway and ER status.
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PMID:Relationship between p53 pathway and estrogen receptor status in endometrioid-type endometrial cancer. 1205 72

The functional consequences of up-regulation of beta-catenin as a transcription factor are complex in different tumors. To clarify roles during squamous differentiation (SqD) of endometrial carcinoma (Em Ca) cells, we investigated expression of beta-catenin, as well as cyclin D1, p53, p21WAF1, and PML (promyelocytic leukemia) in 80 cases of Em Ca with SqD areas, in comparison with cell proliferation determined with reference to Ki-67 antigen positivity. The impact of beta-catenin-T-cell factor (TCF)-mediated transcription was also examined using Em Ca cells. In clinical cases, nuclear beta-catenin accumulation was more frequent in SqD areas, being positively linked with expression of cyclin D1, p53, and p21WAF1, and inversely with Ki-67 and PML immunoreactivity. Significant correlations of nuclear beta-catenin, cyclin D1, p53, and p21WAF1 were noted between SqD and the surrounding carcinoma lesions. The Ishikawa cell line, with stable or tetracycline-regulated expression of mutant beta-catenin, showed an increase in expression levels of cyclin D1, p14ARF, p53, and p21WAF1 but not PML, and activation of beta-catenin-TCF4-mediated transcription determined with TOP/FOP constructs. The cell morphology was senescence-like rather than squamoid in appearance. Moreover, overexpressed beta-catenin could activate transcription from p14ARF and cyclin D1 promoters, in a TCF4-dependent manner. These findings indicate that in Em Cas, nuclear beta-catenin can simultaneously induce activation of the p53-p21WAF1 pathway and overexpression of cyclin D1, leading to suppression of cell proliferation or induction of cell senescence. However, overexpression of beta-catenin alone is not sufficient for development of a squamoid phenotype in Em Ca cells, suggesting that nuclear accumulation is an initial signal for trans-differentiation.
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PMID:Beta-catenin simultaneously induces activation of the p53-p21WAF1 pathway and overexpression of cyclin D1 during squamous differentiation of endometrial carcinoma cells. 1511 20

In the current study, we evaluated p16 expression in rare subtypes of endometrial carcinomas, whose HPV status has been previously examined in order to establish the role of this protein in their pathogenesis. These rare subtypes of endometrial carcinomas are primary squamous endometrial carcinoma (ESCC), endometrial mucinous microglandular adenocarcinoma (EMMA), and endometrial transitional cell carcinoma (ETCC). All tissues, obtained at the time of hysterectomy, were fixed in 10% phosphate-buffered formalin and embedded in paraffin. Serial sections were made for hematoxylin and eosin staining and for immunohistochemistry. Although a previous PCR study has demonstrated that none of these neoplasms showed any signal for HPV DNA, these malignancies did display immunoreactivity for P16(INK4a). In ESCC, P16(INK4a) immunoreactivity was diffuse in 100% of neoplastic cells. In two cases of EMMA, positivity for P16INK4a was zonal. In ETCC, scattered cells were positive for P16INK4a protein. These findings suggest that alteration of p16 could play an etiologic role, without any association to HPV infections, in these rare endometrial carcinomas. However, in our view, other cases of these rare malignancies should be investigated in order to confirm this hypothesis.
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PMID:P16(INK4a) overexpression independent of Human Papilloma Virus (HPV) infection in rare subtypes of endometrial carcinomas. 1749 85