miR-21 Inhibits Non-Small Cell Lung Cancer Cell Proliferation and Promotes Apoptosis

This study assesses miR-21's role in non-small cell lung cancer (NSCLC) cells. miR-21/PTEN RNA level in normal and NSCLC cell (A549) was detected by qPCR. After transfection of miR-21 and inhibitors, cell proliferation was assessed by MTT. PTEN, NF-KB, p53, BCL2, BAX levels were measured after si-PTEN transfection. miR-21 was significantly lower and PTEN was higher in NSCLC cells than normal cells (P < 0.001) and PTEN was negatively associated with miR-21. MTT assay showed that cell survival rate was decreased after miR-21 was inhibited and increased after miR-21 was overexpressed. After inhibiting PTEN, protein expression of proliferation-related factors NF-KB and p53 was decreased. TUNEL experiment showed elevated cell apoptosis after miR-21 was inhibited and decreased apoptosis after miR-21 was overexpressed. Inhibition of PTEN modulated Akt signaling as demonstrated by no changes of Akt expression and decreased p-Akt level along with downregulated BCL2 and BAX. In conclusion, miR-21/PTEN inhibits NSCLC cell proliferation and promotes cell apoptosis.