Abstract
The class III histone deacetylase silent information regulator 1 (SIRT1) is frequently overexpressed in a variety of tumors, including lung cancer; however, its regulatory mechanisms are largely unknown. In this study, we found that an inconsistent trend between SIRT1 protein and mRNA levels in human lung cancer tissues, suggesting that a post-transcriptional mechanism may involved in SIRT1 regulation. Because microRNAs are important post-transcriptional regulators of gene expression, candidate miRNAs that could potentially bind SIRT1 were gained through bioinformatics analyses. We further experimentally validated SIRT1 as the direct target of miR-30a by evaluating SIRT1 expression in lung cancer cells after the overexpression or knockdown of miR-30a and by luciferase assay. Moreover, we showed that miR-30a inhibited proliferation, invasion and promoted apoptosis of lung cancer cells by inhibiting SIRT1 in vitro and in vivo. Taken together, this study identified a new regulatory axis in which miR-30a and SIRT1 regulate the proliferation, invasion and apoptosis of lung cancer cells and lung tumorigenesis.