Role of microRNA-21 and effect on PTEN in Kazakh’s esophageal squamous cell carcinoma

The aim of this study was investigate the role of microRNA-21 (miR-21) and its regulation on phosphatase and tensin homolog deleted from chromosome-10 (PTEN) in Kazakh’s esophageal squamous cell carcinoma (ESCC). MiR-21 expressions were investigated in esophageal cancer cell line Eca109, and 18 pairs of Kazakh’s ESCC and adjacent normal tissues by real-time quantitative PCR (qRT-PCR). To evaluate the role of miR-21 and PTEN, cell proliferations were analyzed with miR-21 mimics or their inhibitor-transfected cells. Moreover, the expressions of PTEN were performed by Western blotting. In Eca109, when transfected with miR-21 mimics, accumulation of miR-21 was obviously increased and expression of PTEN protein was decreased to be approximately 40%, which resulted in the promotion of cell proliferation. However, when transfected with miR-21 inhibitor, expression of miR-21 was declined and PTEN protein was overexpressed to be approximately 79%, which resulted in the suppression of cell proliferation. Both of them had no effect on the level of PTEN mRNA. Compared with adjacent normal tissues, miR-21 expression was significantly higher in tumor ( P