The tumor suppressor gene p53 has been implicated in the regulation of epithelial–mesenchymal transition (EMT) and tumor metastasis by regulating microRNA (miRNA) expression. Here, we report that mutant p53 exerts oncogenic functions and promotes EMT in endometrial cancer (EC) by directly binding to the promoter of miR-130b (a negative regulator of ZEB1) and inhibiting its transcription. We transduced p53 mutants into p53-null EC cells, profiled the miRNA expression by miRNA microarray and identified miR-130b as a potential target of mutant p53. Ectopic expression of p53 mutants repressed the expression of miR-130b and triggered ZEB1-dependent EMT and cancer cell invasion. Loss of an endogenous p53 mutation increased the expression of miR-130b, which resulted in reduced ZEB1 expression and attenuation of the EMT phenotype. Furthermore, re-expression of miR-130b suppressed mutant p53-induced EMT and ZEB1 expression. Importantly, the expression of miR-130 was significantly reduced in EC tissues, and patients with higher expression levels of miR-130b survived longer. These data provide a novel understanding of the roles of p53 gain-of-function mutations in accelerating tumor progression and metastasis through modulation of the miR-130b–ZEB1 axis.
BackgroundEpithelial-mesenchymal transition (EMT) is the key process driving cancer metastasis. Oncogene/self renewal factor BMI-1 has been shown to induce EMT in cancer cells. Recent studies have implied that noncoding microRNAs (miRNAs) act as crucial modulators for EMT. The aims of this study was to determine the roles of BMI-1 in inducing EMT of endometrial cancer (EC) cells and the possible role of miRNA in controlling BMI-1 expression.Methods and resultsWe evaluated the expression of BMI-1 gene in a panel of EC cell lines, and detected a strong association with invasive capability. Stable silencing of BMI-1 in invasive mesenchymal-type EC cells up-regulated the epithelial marker E-cadherin, down-regulated mesenchymal marker Vimentin, and significantly reduced cell invasion in vitro. Furthermore, we discovered that the expression of BMI-1 was suppressed by miR-194 via direct binding to the BMI-1 3'-untranslated region 3'-UTR). Ectopic expression of miR-194 in EC cells induced a mesenchymal to epithelial transition (MET) by restoring E-cadherin, reducing Vimentin expression, and inhibiting cell invasion in vitro. Moreover, BMI-1 knockdown inhibited in vitro EC cell proliferation and clone growth, correlated with either increased p16 expression or decreased expression of stem cell and chemoresistance markers (SOX-2, KLF4 and MRP-1).ConclusionThese findings demonstrate the novel mechanism for BMI-1 in contributing to EC cell invasion and that repression of BMI-1 by miR-194 could have a therapeutic potential to suppress EC metastasis.
Given that the effectiveness of the above two therapeutic options for cervical cancer is currently controversial, the clinical benefits of these therapies should be reevaluated specifically to conserve the quality of life for patients with this disease.
The Fourth Edition of the Guidelines for Treatment of Uterine Body Neoplasm was published in 2018. These guidelines include 9 chapters: 1. Overview of the guidelines, 2. Initial treatment for endometrial cancer, 3. Postoperative adjuvant therapy for endometrial cancer, 4. Post-treatment surveillance for endometrial cancer, 5. Treatment for advanced or recurrent endometrial cancer, 6. Fertility-sparing therapy, 7. Treatment of uterine carcinosarcoma and uterine sarcoma, 8. Treatment of trophoblastic disease, 9. Document collection; and nine algorithms: 1-3. Initial treatment of endometrial cancer, 4. Postoperative adjuvant treatment for endometrial cancer, 5. Treatment of recurrent endometrial cancer, 6. Fertility-sparing therapy, 7. Treatment for uterine carcinosarcoma, 8. Treatment for uterine sarcoma, 9. Treatment for choriocarcinoma. Each chapter includes overviews and clinical questions, and recommendations, objectives, explanation, and references are provided for each clinical question. This revision has no major changes compared to the 3rd edition, but does have some differences: 1) an explanation of the recommendation decision process and conflict of interest considerations have been added in the overview, 2) nurses, pharmacists and patients participated in creation of the guidelines, in addition to physicians, 3) the approach to evidence collection is listed at the end of the guidelines, and 4) for clinical questions that lack evidence or clinical validation, the opinion of the Guidelines Committee is given as a “Recommendations for tomorrow”.
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