MicroRNA-3666-induced suppression of SIRT7 inhibits the growth of non-small cell lung cancer cells.

Sirtuin7 (SIRT7) plays an important role in many cancer types, but its function in non-small cell lung cancer (NSCLC) remains unclear. This study investigated the biological role and underlying mechanism of SIRT7 in NSCLC. Results showed that SIRT7 was highly expressed in NSCLC cell lines, as detected by real-time quantitative polymerase chain reaction and western blot analysis. SIRT7 knockdown by small interfering RNA (siRNA) significantly inhibited the growth of NSCLC cells and induced their apoptosis. Bioinformatics algorithms indicated that SIRT7 was a putative target of microRNA-3666 (miR-3666). Dual-luciferase reporter assay demonstrated that miR-3666 could target the 3'-untranslated region of SIRT7. Western blot analysis revealed that miR-3666 could regulate the protein expression of SIRT7. The miR-3666 overexpression significantly inhibited NSCLC cell growth. The restoration of SIRT7 protein expression significantly abrogated the effect of the miR-3666 overexpression. Moreover, SIRT7 depletion induced by siRNA or miR-3666 overexpression promoted the expression of pro-apoptotic genes. Taken together, our study suggests that SIRT7 functions as an oncogene in NSCLC, and miR-3666 can target SIRT7 to inhibit NSCLC cell growth by promoting the pro-apoptotic signaling pathway. Thus, this study provides novel insights into the development of new and potential treatments for NSCLC.