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

• DOI: 10.1007/s11033-010-0480-9
• Publication Date: 2010-11-19T06:45:01Z
• Authors: Wen-jing Ma; Guo-dong Lv; Aerziguli Tuersun; Qing Liu; Hui Liu; Shu-tao Zheng; Cong-gai Huang; Jun-guo Feng; Xing Wang; Ren-yong Lin; Ilyar Sheyhidin; Xiao-mei Lu
• Keywords: China; 0303 health sciences; Esophageal Neoplasms; PTEN Phosphohydrolase; Transfection; Kazakhstan; 3. Good health; Gene Expression Regulation, Neoplastic; MicroRNAs; 03 medical and health sciences; Cell Line, Tumor; Carcinoma, Squamous Cell; Disease Progression; Animals; Humans; Cell Proliferation

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 < 0.05). Specifically, patients with cancer cell invasion deep into esophageal serosa showed significantly higher expression of miR-21. Protein expression of PTEN was significantly lower in tumor compared with normal tissues (P < 0.05); however, mRNA expression of PTEN had no obvious significance between them. Furthermore, there was a significantly inverse correlation between miR-21 expression and PTEN protein levels (p < 0.05). The author concluded that MiR-21 was overexpressed in vitro and ESCC, and promoted the cell proliferation, might target PTEN at post-transcriptional level, and regulated the cancer invasion in Kazakh's ESCC.