CARM1 promotes the proliferation of bladder cancer (BC) cells. (A–C) T24 cells were transfected with LV−shCARM1−1 and LV−shCARM1−2, and J82 cells were transfected with LV−oeCARM1 or their corresponding control lentivirus, and western blotting and RT–qPCR were used to detect the CARM1 and CDK4 proteins (A,B) or mRNA (C) expression. (D) A CCK−8 assay was performed to examine cell viability after the treatment described in (A). (E,F) T24 cells were transfected with LV−shRBM5 or LV−shCARM1 alone or in combination, after which the colony formation assay was used to measure cell proliferation. (G,H) J82 cells were transfected with LV−oeRBM5 or LV−shCARM1 alone or in combination, and the colony formation assay was used to measure cell growth. All data were derived from three independent experiments and expressed as the mean ± standard error of the mean (SEM). * p < 0.05, ** p < 0.01, *** p < 0.001 vs. their corresponding controls.