Conclusion
MicroRNA-21 promotes the proliferation of lung cancer cells and inhibits the apoptosis of lung cancer cells by the AKT/P-AKT/cleaved-caspase 3/MMP-2/MMP-9 signaling pathway.
Methods
In vitro cell migration and invasion potential were determined by Transwell chamber assays. FACS was used to assess the effect of miR-21 on A549 cell cycle and apoptosis. 4-6 week-old female mice were utilized to establish a lung cancer model. The pathologic biopsy was processed by H&E staining. The expression of the proteins PTEN, RECK and Caspase 3 were detected through immunohistochemy and tumor cell apoptosis was measured by TUNEL.
Objective
This study aimed to demonstrate the effects of miR-21 on the growth, migration, and invasion of lung cancer cells A549 in vitro and the possible mechanism.
Results
Transwell chamber assays showed that the cells going through the membrane increased significantly compared to the negative control (P<0.05). The tumor volume resulting from miR-21 mimics was significantly greater than in normal mice. Serum ELISA showed that the protein expression levels of MMP-2 and MMP-9 in miR-21 overexpression group were increased significantly. In addition, H&E staining results showed that in miR-21 overexpression tissue, invasion is more severe and immunohistochemical results proved that the miR-21 overexpression group had high expression of Caspase 3 protein but the expression of PTEN and RECK were decreased. TUNEL experiments show that increased the expression of miR-21 can inhibit the apoptosis of tumor cells.