Fig. 5. Effects of C259A mutation on growth and tumorigenicity of PC-3 cells.
(A) Morphology of PC-3 cells transiently transfected with green fluorescent protein (GFP)-tagged STAT3WT or GFP-tagged STAT3C259A under phase contrast microscope. (B) Western blots of E-cadherin and N-cadherin for PC-3 cells transfected with GFP-tagged (STAT3WT) or GFP-tagged (STAT3C259A). (C) Effect of Cys259 mutation of STAT3 on tumor growth in a xenograft tumor model. Human PC-3 cells were transfected with GFP-tagged STAT3WT or GFP-tagged STAT3C259A, and 1 × 107 cells were injected subcutaneously into BALB/c nude mice (n = 3 per group). (D) Representative fluorescence microscopy images of GFP-GFP-STAT3WT versus GFP-STAT3C259A overexpressing xenografted tumor. Cells were fixed with 4% paraformaldehyde and stained for GFP antibody and detected by fluorescence. Magnification: ×20. (E) Immunohistochemistry was conducted to measure the comparative expression of P-STAT3Y705 in STAT3WT and STAT3C259A overexpressing xenograft tumor. Scale bar, 200 μm. GFP, green fluorescent protein.