RÉSUMÉ
@#Objective: To investigate the expression of miR-1269a in esophageal squamous cell carcinoma (ESCC) tissues and its effect on the malignant biological behaviors of ESCC KYSE30 cells, as well as to explore the underlying mechanism. Methods: Ninety specimens of ESCC tissues and adjacent para-cancerous tissues were obtained from patients underwent surgery in Fourth Hospital, Hebei Medical University. In addition, normal esophageal immortalized epithelial cells and esophageal cancer cell lines were also collected. The expression level of miR-1269a in above mentioned tissues and cell lines was examined by Real-time fluorescent quantitative PCR. After being transfected with miR-1269a mimics and inhibitors, the effects of miR-1269a on proliferation, migration, invasion and colony formation of KYSE30 cells were detected by MTS, Transwell and colony formation assay, respectively. The bioinformatics tool was used to predict the possible target genes of miR-1269a. Then the regulation effect of miR-1269a on target gene expression was validated by WB and Dual-luciferase reporter assay. After being transfected with SOX6 plasmid, the effects of SOX6 on the proliferation, migration, invasion and colony formation of KYSE30 cells were detected by MTS, Transwell and colony formation assay, respectively. At last, rescue assay was used to confirm the results. Results: The expression level of miR-1269a in ESCC tissues was significantly higher than that in adjacent para-cancerous tissues (P<0.05), and the expression level of miR-1269a in ESCC cell lines was significantly elevated compared with the normal epithelial cells (P<0.05 or P<0.01). The capacities of proliferation, invasion, migration and colony formation of KYSE30 cells in miR-1269a mimics transfection group were obviously higher than those in mimics NC group, while those abilities in miR-1269a inhibitor transfection group were significantly lower than those in inhibitor NC group (P<0.05 or P<0.01). Bioinformatics analysis showed that miR-1269a could combine with 3’UTR region at SOX6 gene; and after miR-1269a over-expression, the expression level of SOX6 and luciferase activity in KYSE30 cells were significantly reduced (P<0.05). Rescue assay showed that miR1269a over-expression could promote the proliferation, invasion and migration of KYSE 30 cells, while simultaneous transfection of SOX6 could partially reverse the promotion effect of miR-1269a mimics. Conclusion: The expression level of miR-1269a in ESCC tissues and cell lines is significantly increased, and it could enhance proliferation, migration, invasion and colony formation of KYSE30 cell line.And its mechanism may be related to the suppression of its target gene SOX6.