miR-373 Suppresses Cell Proliferation and Apoptosis via Regulation of SIRT1/PGC-1α/NRF2 Axis in Pancreatic Cancer

OBJECTIVE: Our study aimed to investigate function and mechanism of miR-373 in proliferation and apoptosis of pancreatic cancer (PC) cells by regulating NAD+-dependent histone deacetylase sirtulin 1 (SIRT1). MATERIALS AND METHODS: This experimental study included two PC cell lines AsPC-1 and PANC-1 in which expression levels of miR-373 and SIRT1 were manipulated. The level of miR-373 was detected by reverse transcription quantitative polymerase chain reaction (RT-qPCR) method. Expression levels of SIRT1, BCL-2, BAX, cleaved CASPASE-8/9/3, PARP, PGC-1α, NRF2, eNOS and iNOS were examined via RT-qPCR and western blotting, respectively. The binding sites of miR-373 on the SIRT1 were examined via dual-luciferase assay. Cell proliferation and apoptosis were examined by MTT assay, colony formation assay, Annexin-V/PI staining and TUNEL assay. The oxidative metabolic changes were monitored by reactive oxygen species (ROS), malondialdehyde (MDA) and superoxide dismutase (SOD) detection. RESULTS: miR-373 could specifically target the 3’-UTR of SIRT1 and reduce its expression in PC cells. Either elevated expression of miR-373 or partial loss of SIRT1 inhibited cell proliferation and induced cell apoptosis. Accumulation of BAX and cleaved CASPASE-8/9/3, inhibition of PGC-1α/NRF2 pathway, increase oxidative stress and reduction of BCL-2 as well as uncleaved PARP were found in the presence of miR-373 or the absence of SIRT1. Overexpression of SIRT1 could reduce anti-proliferative and pro-apoptotic effects of miR-373. CONCLUSION: Overall, this study concluded that miR-373-dependent SIRT1 inhibition displays anti-proliferative and pro- apoptotic roles in PC cells via PGC-1α/NRF2 pathway, which highlights miR-373 as a potential target for PC treatment.