Fig. 4

The interaction of HDGF with STAT3 promotes its transcription activity. A Immunoprecipitation followed by silver staining of the HDGF binding proteins. B, C Immunoprecipitation and western blotting for HDGF association with STAT3 protein in HEK-293 T cells. D HDGF interacts with STAT3 in MDA-MB-231 cells. E Luciferase assay detected STAT3 downstream genes. F HDGF knockdown lowers the mRNA levels of STAT3 downstream genes in MDA-MB-231 cells. G Effects of STAT3–Tyr705 and STAT3–Ser727 phosphorylation levels in HDGF knockdown breast cancer cells. H, Quantification of protein in (G). I Effects of the cellular distribution of the phosphorylated STAT3–Y705 and STAT3–S727 in HDGF knockdown breast cancer cells. J Quantification of protein in (I). K, L Cell proliferation (K) and surviving fractions (L) for MDA-MB-231 cells transfected with wild–type STAT3, the STAT3–S727D mutant or control after irradiation. As shown in E, F, H, J, K, and L, Error bars ± S.D. *P < 0.05. ***P < 0.001. Data are representative of three independent experiments