Fig. 6

CDK5 depletion is associated with poor prognosis and chemoresistance in patients with gastric cancer. (A) Western blots of CDK5 in human gastric cancer with resistance or sensitivity to chemotherapy. Densitometric analysis of CDK5 expression (right bottom). (B) Representative immunohistochemical staining (scale bars, 100 μm) of CDK5 in human gastric tumors and adjacent nontumor tissues. Histogram showing percentages of CDK5 high and low staining in tumor and nontumor tissues (right bottom). (C) Kaplan–Meier survival analysis for CDK5 staining in the local cohort (upper left) or mRNA levels (bottom right) in the TCGA and GEO cohorts. (D) Kaplan–Meier survival analysis for patients with and without ACT treatment in CDK5 high- or low-expression cases in the local cohort. (E) Adjusted hazard ratio for patients who received ACT in the CDK5 high/low expression group using Cox regression compared with patients who did not receive ACT. (F) Schematic summary of the role of CDK5 in gastric cancer cell apoptosis. In brief, oxaliplatin-induced CDK5 stabilizes DP1 through direct binding with it and subsequent activation of E2F1 signaling, which promotes tumor cell apoptosis and sensitizes cancer cells to chemotherapy