PRMT1 and osteosarcoma: Consequently, by using CCK-8 method, we observed that cell proliferation was inhibited by TIPE1 but clearly increased by TIPE1-PRMT1 co-expression (cells transfected with PRMT1 alone was set as a positive control) (Fig. 5F), suggesting that TIPE1 suppresses osteosarcoma proliferation in a PRMT1-dependent manner.