Figure 4.

S. typhimurium strain VNP20009 carrying SPRY2 expressing plasmid induced down-regulation of ERK phosphorylation and inhibition of proliferation in tumor tissues of mice bearing melanoma. A. Western blotting analysis of the expression of phospho-ERK and total-ERK in tumor tissues of mice treated with indicated strains. α-tubulin was served as loading control. B. Statistical result of the extent of ERK activation for groups as indicated. C. Immunohistochemical staining of tumor sections of mice treated as indicated with Ki-67 antibody. Black arrows, Ki-67 positive cells. D. Statistical result of Ki-67 index (ratio of the number of positive staining cells to the number of all cells) for groups as indicated. Data are presented as mean ± SD, *p < 0.05, **p < 0.01, ***p < 0.001 (n = 3 mice), N.S: not significant.