Abstract:

Objective   To explore the effect of miR-205 on PEG3(Paternally Expressed Gene 3) in  endometrial cancer celllines. Methods   Use immunohistochemical method to detect the different expressions of PEG3 in normal endometrial tissue and high, moderately, poorly differentiated endometrial carcinoma tissues. Three different differtiation kinds of endometrial cancer cell lines which had higher expressions of miR-205 than normal endometrial cell line were chosen by RT-PCR. Then, CCK8 and flow cytometry analysis were used to detect the cell proliferation and apoptosis before and after the up-regulation of miR-205. Western blot, RT-PCR, and the dual luciferase assay were used to explore whether miR-205 had a target suppression effect on PEG3. Results   The expression level of PEG3 in normal endometrial tissue was obviously higher than those in endometrial carcinoma tissues. After miR-205 was up-regulated in the three endometrial cancer cell lines, the cell proliferation was improved and the cell apoptosis decreased. Western blot showed that the PEG3 expression level decreased and the expressions of two key proteins in WNT pathway, β-catenin and c-myc, increased correspondingly. To the contrary, PEG3 mRNA showed no statistical significance change by RT-PCR. Dual luciferase assay demonstrated that miR-205 directly down-regulate PEG3 by targeting at the 3’UTR of PEG3 mRNA.Conclusion   MiR-205 acts on the 3’UTR of PEG3 mRNA and suppresses the expression of PEG3 at the post-transcriptional level.That prompts PEG3 is the direct target gene of miR-205.

Key words: Endometrial tumor; PEG3; miR-205； WNT pathway， Dual luciferase assay