[Prevention and treatment of endometrial cancer].

Endometrial cancer is rising in incidence, especially in young women. This rise in incidence has implications for both primary prevention and screening in high-risk population. In the past several years, our understanding of the integration of clinically related genomic and pathologic data optimized the management of endometrial cancer. The updated 2023 FIGO staging includes the histological and molecular classification to better reflect the improved understanding of the heterogenous nature of endometrial carcinoma. Standard primary treatment is quite essential, however, selection of patients for adjuvant radiation or chemotherapy remains in controversy. Molecular characterization of endometrial cancer is becoming critical in directing treatment for advanced and recurrent disease, and the addition of immunotherapy to frontline chemotherapy is becoming the standard of care. More attention should be given to increase awareness of survivorship issues and improve patient quality-of-life.

[Lithocholic acid decreases mRNA stability of nuclear receptor PPARα by upregulating miR-21 expression in hepatoma HepG2 cells].

OBJECTIVE: To investigate the regulatory effects of lithocholic acid (LCA) on nuclear receptor peroxisome proliferatoractivated receptor-alpha (PPARα) mRNA stability at the post-transcriptional level. METHODS: PPARα 3'UTR luciferase reporter gene vectors were constructed and transfected into HepG2 cells to observe the changes in cellular luciferase activity in response to LCA treatments. Bioinformatic prediction and miRNA PCR array technique were used to identify the differentially expressed miRNAs induced by LCA and their potential binding sites on the 3'UTR. The binding sites (Mut1, Mut2 and Mut1+Mut2) were mutated to compare the changes in cellular luciferase activity following LCA treatment. Western blotting and RTqPCR were used to detect the activated signaling pathway and the expression levels of its downstream transcription factors in LCA-treated cells. The changes in PPARα protein expression level were detected in the cells following overexpression of the transcription factors. RESULTS: Treatment with 100 µmol/L LCA significantly reduced luciferase activity of PPARα 3'UTR1 and 3'UTR2 in HepG2 cells by more than 50% (P<0.01) and induced significant upregulation of miR-21 and miR-22, especially the former (by 2.35 folds, P<0.05). Two predicted miR-21-binding sites in the 3'UTR1 were mutated to construct Mut1, Mut2 and Mut1+Mut2 reporter gene vectors. LCA treatment down-regulated 3'UTR1 luciferase activity by 51%, while Mut1, Mut2, and Mut1+Mut2 were down-regulated by 37%, 39%, and 13%, respectively. LCA caused ERK1/2 phosphorylation and activation of the ERK1/2 signaling pathway, and treatment with 100 µmol/L LCA upregulated the expression of transcription factor early growth response 1 (EGR1) by 5.83 folds (P<0.01). Transient overexpression of EGR1 significantly decreased cellular PPARα protein levels (P<0.05). CONCLUSION: LCA reduces PPARα mRNA stability and thus decreases PPARα mRNA and protein expressions in hepatocytes by activating the ERK1/2 signaling pathway and upregulating EGR1 and miR-21, which targets 3'UTR regulatory region of PPARα mRNA.