L-plastin expression enhances metastasis in a phosphorylation dependent manner. (A) Quantification of tumor metastasis monitored by bioluminescence imaging. Numbers of single spots, representing metastatic lesions, were counted from a ventral and dorsal view per animal and plotted over time after cancer cell injection. Results were analyzed using student’s t-test, data represent means ± SEM (n = 12 for MV3 and MV3 control; n = 13 for MV3 LPL and MV3 S5A LPL; * = p < 0.05 and ** = p < 0.01 for MV3 LPL vs. MV3 or MV3 control or MV3 S5A LPL; ns = not significant). (B) Representative pictures of dorsal optical images obtained at the indicated time points after injection of mice with MV3, MV3 control, MV3 LPL and MV3 S5A LPL cells. (C) L-plastin expression and phosphorylation in metastatic lesions of mice injected with MV3 LPL cells. Representative immunohistochemical pictures of excised metastatic lesions of mice bearing MV3 LPL tumors. They were stained for IgG control, total L-plastin and phospho Ser5 L-plastin.