Circular RNA La-related protein 4 inhibits cell proliferation, migration, and invasion and sponges microRNA-367 in non-small cell lung cancer.

This study aimed to investigate the effect of circular RNA (circRNA) La-related protein 4 (LARP4) on inhibiting the malignant progression of non-small cell lung cancer (NSCLC) cells. CircRNA LARP4 expression in a human normal lung epithelial cell line and NSCLC cell lines was detected by reverse transcription-quantitative polymerase chain reaction. CircRNA LARP4 overexpression and control overexpression plasmids were transfected into NCI-H1650 cells; circRNA LARP4 knockdown and control knockdown plasmids were transfected into A549 cells. CircRNA LARP4 and microRNA (miR)-367 expressions, cell proliferation, apoptosis, migration, and invasion after transfection were investigated. Moreover, the luciferase reporter assay was used to explore the interaction between circRNA LARP4 and miR-367. CircRNA LARP4 was decreased in NSCLC cell lines (including A549, NCI-H1650, NCI-H1299, and HCC827 cells) compared to BEAS-2B cells. In NCI-H1650 cells, circRNA LARP4 overexpression inhibited cell proliferation, migration, and invasion, while promoting apoptosis. In A549 cells, circRNA LARP4 knockdown increased cell proliferation, migration, and invasion, while decreasing apoptosis. Moreover, miR-367 was decreased by the overexpression of circRNA LARP4, but increased by the knockdown of circRNA LARP4; and further luciferase reporter assay revealed that circRNA LARP4 could directly bind to miR-367. In conclusion, circRNA LARP4 is downregulated, suppresses cell proliferation, migration, and invasion, and acts as a sponge of oncogene miR-367 in NSCLC.