RETRACTED: Effects of microRNA-374 on proliferation, migration, invasion, and apoptosis of human SCC cells by targeting Gadd45a through P53 signaling pathway (Publication with Expression of Concern. See vol. 40, 2020) (Retracted Article)

The present study investigated the effects of microRNA-374 (miR-374) on human squamous cell carcinoma (SCC) cell proliferation, migration, invasion, and apoptosis through P53 signaling pathway by targeting growth arrest and DNA-damage-inducible protein 45 alpha (Gadd45a). Skin samples were collected from patients with skin SCC and normal skin samples. Expression of miR-374, Gadd45a, P53, P73, P16, c-myc, bcl-2, Bax, caspase-3, and caspase-9 were detected using quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting. A431 and SCL-1 cells were divided into blank, negative control (NC), miR-374 mimics, miR374 inhibitors, siRNA-Gadd45a, and miR-374 inhibitors + siRNA-Gadd45a groups. Their proliferation, migration, invasion, cell cycle, and apoptosis were evaluated by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay, scratch test, Transwell assay, and flow cytometry. SCC skin tissues exhibited decreased expression of miR-374, P73, P16, Bax caspase-3 and caspase-9, and increased levels of Gadd45a, P53, c-myc, and Bcl-2 compared with the normal skin tissues. The miR-374 inhibitors group exhibited decreased expression of miR-374, P73, P16, Bax caspase-3 and caspase-9, and increased expression of Gadd45a, P53, c-myc, and Bcl-2, enhanced cell proliferation, migration, and invasion, and reduced apoptosis compared with the blank and NC groups; the miR-374 mimics group followed opposite trends. Compared with the blank and NC groups, the miR-374 inhibitors + siRNA-Gadd45a group showed decreased miR-374 level; the siRNA-Gadd45a group showed elevated levels of P73, P16, Bax, caspase-3 and caspase-9, decreased levels of Gadd45a, P53, c-myc, and Bcl-2, reduced cell proliferation, migration, and invasion, and accelerated apoptosis. miR-374 induces apoptosis and inhibits proliferation, migration, and invasion of SCC cells through P53 signaling pathway by down-regulating Gadd45a.