Figure 6.
RASAL2 S351 phosphorylation promotes breast cancer growth and indicates a poor prognosis in breast cancer patients. (A and B) RASAL2-CT or RASAL2-KO MCF7 and MDA-MB-231 cells with reconstituted expression of MYC-RASAL2 WT, MYC-RASAL2351D and MYC-RASAL2351A were cultured in the present (A) or absent (B) of glucose-deprived medium for 24 h, and cell viability was determined by MTT assays. Results are reported as means ± SEM of three replicates. **p < 0.01, N.S., not significant. (C – E) RASAL2-CT and RASAL2-KO MCF7 or MDA-MB-231 cells stably expressing MYC-RASAL2 (WT, S351D, S351A) were subcutaneously injected into nude mice (n = 5/group). (C) Tumor volumes were calculated, and (D) representative tumors were photographed. (E) Tumor tissues in (C) were used for immunoblotting as indicated. Data represent the mean ± SEM of five mice. *p < 0.05, **p < 0.01. (F and G) IHC staining of breast tissue microarray (TMA) with antibody against RASAL2 S351 phosphorylationand PRKAA-T172 phosphorylation were performed. Brown staining indicates positive immune reactivity. Chi-squareanalysis was performed depending on the staining scores. (H) Kaplan-Meier curves showing the overall survival rates of breast cancer patients with high or low expression of p-S351-RASAL2. Statistical significance was calculated by using a log-rank test