The tumor suppressor gene TP53 is mutated exclusively with the HYDIN, KRAS, and PTEN genes in large intestine, lung, and endometrial cancers respectively, indicating that TP53 takes part in different signaling pathways in different cancers.
For example, PTEN/AKT pathway and its downstream targets and the mTOR (mammalian target of rapamycin) pathway have been shown to play an important role in endometrial cancer pathogenesis.
PTEN immunohistochemical loss, a common event in endometrioid-type endometrial carcinoma and associated with local immune suppression in melanoma, was not associated with PD-L1 expression or lymphocyte/macrophage infiltration of the tumor.
Moreover, the mean age of onset of both colorectal cancer (MSH6 v MSH2/MLH1 = 55 years v 44/41 years) and endometrial carcinomas (MSH6 v MSH2/MLH1 = 55 years v 49/48 years) is delayed.
A tissue microarray was constructed from paraffin wax-embedded blocks from 95 endometrial carcinomas (EC), previously studied for microsatellite instability, as well as for alterations in PTEN, k-RAS and beta-catenin.
To test the hypothesis that insulin signalling plays a key role in the development of EC in women with PCOS by measuring and comparing the expression of three key genes involved in the insulin signalling pathway (IGF1, PTEN and IGFBP1) in endometrial tissue obtained from three groups of women; PCOS without EC, women with EC without PCOS and non-PCOS women without EC (controls).
Mutations in MSH6 were less prevalent, and MSH6 mutation carriers presented with colorectal and endometrial cancer at later ages than carriers of mutations in MSH2 or MLH1.
Two series of endometrial cancer and precancer (endometrial intraepithelial neoplasia, as diagnosed by computerized morphometric analysis) tissue samples were studied, one for PTEN mutations by the use of denaturing gradient gel electrophoresis and another for PTEN protein expression by immunohistochemistry.
We hypothesized that in PTEN-mutated endometrial cancers, hyperactive Akt signaling downregulates progesterone receptor B (PRB) transcriptional activity, leading to overall impaired progestin responses.
Lynch syndrome is caused by germline mutations in MSH2, MLH1, MSH6, and PMS2 mismatch-repair genes and leads to a high risk of colorectal and endometrial cancer.
Furthermore, the mean age at diagnosis of endometrial cancer in Japanese MSH6 mutation carriers (49.2 years) was earlier than previous reports from Western countries (56.5 years).
A mutational analysis of three DNA mismatch repair (MMR) genes (hMLH1, hMSH2 and hMSH6) in patients with endometrial cancer who meet our criteria for familial predisposition to HNPCC-associated endometrial cancers was performed.
Proliferation, transwell and apoptosis assay suggested that MDH2 enhanced the proliferation, migration and invasion but inhibited the apoptosis of endometrial cancer cell line through suppressing PTEN.
PTEN, a tumor suppressor commonly mutated (50%) in endometrial carcinoma, is found mutated in endometrioid carcinoma of the ovary, but not in other forms of ovarian cancer.
We also studied cell blocks obtained from one PTEN-defective endometrial cancer cell line, after transfection with either a plasmid encoding wild-type PTEN or the empty vector.
Archival paraffin embedded tumour from women with endometrial cancer enrolled in NCIC CTG studies: EN5 (stage I/II) and IND 126, 148 and 160 (advanced/recurrent disease) were examined for MSI using BAT25/26 and for PTEN expression using immunohistochemistry.
However, not all mediators of PTEN signaling pathways have been clarified, and, during efforts to identify such molecules, we previously induced expression of the DUSP1 and BTG1 genes by introducing exogenous PTEN into endometrial cancer cell lines.
Prophylactic hysterectomy in HNPCC should be restricted to women in whom abdominal surgery for other reasons is performed and to those with particularly increased risk such as MSH6 mutation carriers and/or women with multiple relatives with endometrial carcinoma.