PRMT1 is critical to FEN1 expression and drug resistance in lung cancer cells

•PRMT1 is important to the growth and drug resistance of lung cancer cells.•Flap endonuclease 1 (FEN1) was identified as a novel target of PRMT1 in lung cancer cells.•PRMT1-mediated arginine methylation is critical to the stability of FEN1 protein. The up-regulation of PRMT1 is critical to the cell growth and cancer progression of lung cancer cells. In our research, we found that PRMT1 is important to the DNA repair ability and drug resistance of lung cancer cells. To demonstrate the functions of PRMT1, we identified Flap endonuclease 1 (FEN1) as a post-translationally modified downstream target protein of PRMT1. As a major component of Base Excision Repair pathway, FEN1 plays an important role in DNA replication and DNA damage repair. However, the detailed mechanism of FEN1 up-regulation in lung cancer cells remains unclear. In our study, we identified PRMT1 as a key factor that maintains the high expression levels of FEN1, which is critical to the DNA repair ability and the chemotherapeutic drug resistance of lung cancer cells.