Objective      To study the potential role of C3G/ Rap1 and Dock180/Rac1 signal pathway in infiltration of ovarian cancer.       Methods       Expressions of C3G in Dock180-silenced ovarian cancer SKOV3 cells were detected by Western blotting. Expressions of C3G and Dock180 in ovarian cancer tissue were compared by immunohistochemical analysis. The locations of D180/C3G and their downstream Rac1/Rap1 proteins were demonstrated in ovarian cancer cell SKOV3 by means of immunofluorescence staining.       Results      The expression level of C3G was significantly higher in Dock180-silenced SKOV3 cells than in wild type

blank plasmid transfected

and negative plasmid transfected cells （P0.05）. The expression of C3G in ovarian cancer tissue was inversely related with that of Dock180 (P0.05). Both C3G and Dock180 were mainly distributed in the cytoplasm. The downstream Rap1 and Rac1 proteins were expressed both in the cytomembrane and in the cytoplasm. However

Rap1 was mainly expressed in the cytoplasm while Rac1 was mainly expressed in the cytomembrane and its folds.       Conclusion       The expression of C3G in ovarian cancer cells and tissue is inversely related with that of Dock180. The Rap1 and Rac1 are differently distributed in ovarian cancer cells

which may be related with the different roles of C3G/Rap1 and Dock180/Rac1 signal pathway in the infiltration of ovarian cancer.