[Role of Rho GTPase in inhibiting metastatic ability of human prostate cancer cell line PC-3 by omega-3 polyunsaturated fatty acid].

BACKGROUND & OBJECTIVE: Recently, researches refer to the influence of polyunsaturated fatty acid (PUFA) on cancer initiation and progression had been highly concerned. This study was to investigate the effects of 2 kinds of omega-3 PUFA, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), on the metastatic ability of human prostate cancer cell line PC-3, and explore the role of Rho GTPase in inhibiting cancer metastasis by omega-3 PUFA.

METHODS

MTT assay was used to determine the effects of omega-3 PUFA on the proliferation of PC-3 cells. Adhesion assay, invasion assay, and migration assay were used to observe the effects of omega-3 PUFA on the metastatic ability of PC-3 cells. Western blot was used to observe the effects of omega-3 PUFA on the expression of RhoA, Rac1, Rac2, and Cdc42 proteins in PC-3 cells. Laser confocal microscopy was used to investigate the effect of omega-3 PUFA on the reorganization of the microfilaments and microtubules marked by immunofluorescent cytochemistry technology.

RESULTS

Both EPA and DHA inhibited the proliferation of PC-3 cells, and the proliferation inhibition rate increased along with the increase of the concentration and treatment time. When treated with 60 mumol/L EPA or DHA for 48 h, the abilities of adhesion, invasion and migration of PC-3 cells were inhibited (P<0.05). omega-3 PUFA significantly suppressed the expression of Rac1, Rac2 and Cdc42 proteins (P<0.05), influenced the distribution and structure of sytoskeletons.

CONCLUSION

omega-3 PUFA could inhibit the metastatic ability of PC-3 cells through down-regulating the expression of Rho GTPase and inhibiting the cytoskeleton reorganization.