BACKGROUND Gastric cancer (GC) is a malignant tumor originating from gastric mucosal epithelial cells that has high morbidity and mortality. microRNAs (miR) are important diagnostic markers and therapeutic targets in this disease. AIM To explore the mechanism of miR-125a-5p in the pathogenesis of GC. METHODS The expression levels of miR-125a-5p, SERPINE1 and DNMT1 in GC cells and tissues were detected by real-time polymerase chain reaction (PCR) and Western blotting. Methylation-specific PCR was used to detect the level of miR-125a-5p methylation. A cell counting kit 8 assay, scratch test, and a Transwell assay were performed to detect the proliferation, migration, and invasiveness of HGC27 cells, respectively. The expression of the epithelial mesenchymal transition (EMT)-related proteins E-cadherin, N-cadherin and vimentin in HGC27 cells was detected by Western blotting, while the expression of vimentin was detected by immunofluorescence. RESULTS This study revealed that miR-125a-5p was expressed at low levels in GC clinical samples and cells and that miR-125a-5p overexpression inhibited the proliferation, migration, invasiveness and EMT of GC cells. Mechanistically, miR-125a-5p can reduce GC cell proliferation, promote E-cadherin expression, inhibit N-cadherin and vimentin expression, and reduce the EMT of GC cells, thus constraining GC cells to a certain extent. Moreover, DNMT1 inhibited miR-125a-5p expression by increasing the methylation of the miR-125a-5p promoter, thereby promoting the expression of SERPINE1, which acts together with miR-125a-5p to exert antagonistic effects on GC. CONCLUSION Our study revealed that DNMT1 promoted SERPINE1 protein expression by inducing miR-125a-5p methylation, which led to the proliferation, migration and occurrence of EMT in GC cells.
[1]Yanan Hosp Kunming City, Dept Gen Surg, 245 Renmin East Rd, Kunming 650051, Yunnan, Peoples R China.
[2]YanAn Hosp Kunming City, Dept Digest Internal Med, Kunming 650051, Yunnan, Peoples R China.
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