Figure 4.

SH3BP1 is a direct target gene of TAZ, enhancing the cell migration in the prostate cancer cells. A, decreased expression of SH3BP1 in TAZ knockdown DU145 cells. The protein and mRNA levels of SH3BP1 in the TAZ knockdown DU145 cells were analyzed by Western blotting and qPCR, respectively. B, overexpression of TAZ promoted SH3BP1 expression in the RWPE1 cells. The protein and mRNA levels of SH3BP1 in vector control, TAZ^S89A, and TAZ^S89A-S51A RWPE1 cells were analyzed by Western blotting and qPCR, respectively. CTGF, a well known downstream target gene of TAZ, was included as the positive control. C, TAZ enhanced the luciferase activity of the SH3BP1 WT promoter but not the M-CAT motif mutant. Luciferase assay of the SH3BP1 WT and M-CAT motif mutant promoters co-transfected with TAZ expression plasmid. *, p < 0.05 by the Student's t test. D, TAZ was enriched in the SH3BP1 promoter region. ChIP analysis of TAZ in the DU145 cells was performed. The enrichment of TAZ in the SH3BP1 promoter was analyzed by qPCR with SH3BP1 promoter-specific primers. *, p < 0.05 by the Student's t test. E, knockdown of SH3BP1 impaired the cell migration induced by overexpression of TAZ in RWPE1 cells. The cells were transfected with NC and SH3BP1 siRNA for 2 days. The cell migration ability of these cells was analyzed by Transwell assay. Representative images of the Transwell migration were shown. Relative migration ability was normalized to the vector/siCON group. *, p < 0.05 by the Student's t test. F, the correlation of SH3BP1 with Hippo target genes (CTGF, AXL) in the TCGA prostate cancer dataset was shown. The Pearson's correlation coefficient and Spearman's correlation coefficient values were generated by the cBioPortal. Error bars, standard deviation.