Figure 4.

KLF2 as a tumor suppressor in mouse models and its effect on human tumors. (a) Effect of sh-EZH2 knockdown (left) or KLF2 transfection (right) on the growth of U2OS cells inoculated into nude mice. Tumor volume was monitored over time, and the tumor was excised and weighed after 24 days. EZH2 depletion or KLF2 overexpression cause a reduction in tumor volume and weight. (b) Significantly lower mortality following tail-vein injection in the mice of 1 × 10⁶ U2OS cells was observed in U2OS-pCMV-KLF2 or U2OS-shEZH2 cells in comparison with the empty vector-transfected cells (P<0.001) (c) EZH2 and KLF2 expression in clinical cancer samples determined by immunostaining in prostate and breast cancer tissue microarrays. KLF2 expression was inversely associated with EZH2 expression in prostate (Pearson's correlation coefficient r²=0.32, P<0.05, n=40) and breast (Pearson's correlation coefficient r²=0.57, P<0.05, n=15) cancer. (d) The high expression of EZH2 associated with the low expression of KLF2 predicts overall shorter survival in breast and prostate cancer (Kaplan–Meier analysis, P=0.013 and P=0.062, respectively).