Figure 3. RBM4 inhibits cancer progression.

(A) RBM4 effects on the proliferation of various cancer cells, including H157, MDA-MB-231, SKOV3, Panc-1, HepG2, and PC-3. The cells were stably transfected with RBM4 or vector control and analyzed by colony formation (upper panel) or soft agar (lower panel) assays. All experiments were performed in triplicates, with mean +/− SD of relative colony numbers plotted (p values from t-test). Scale bar = 100 µm in lower panels. Images of the whole plate are shown in upper panel. (B) Different cancer cell lines expressing RBM4 or vector control were analyzed by wound healing assay. Percent of wound closure was measured from triplicate experiments, with mean +/− SD plotted (p values from t-test). Scale bar = 200 µm. (C) Levels of RBM4 in the indicated NSCLC cell lines and normal bronchial cells were measured by western blot. (D) H157 cells stably expressing RBM4 or vector control were grown for 9 days, with cell numbers counted every two days. The changes of cell numbers were compared to day 0. The mean +/− SD from three experiments was plotted. (E) H157 cells expressing full length (FL), or the N- or C-terminal fragments of RBM4 were analyzed by colony formation assay. Representative pictures of the whole plates from triplicate experiments are shown. The mean +/− SD of relative colony numbers were plotted, with p values calculated by t-test. (F) H157-luc-RBM4 and control cells were subcutaneously injected into left and right flank of seven nude mice. The growth of xenograft tumors was monitored by bioluminescence imaging on day 3 and 35, and pictures of two representative mice were shown. (G) Pictures of the tumors removed after 35 days. (H) The average sizes of xenograft tumors measured every three days (n=7, error bars indicate +/− SD, p<0.05 by t-test). See also Figure S3.