Objective: To investigate the mechanism of enhancement of invasion of hepatocellular carcinoma (HCC) cells by lysophosphatidic acid (LPA).
Methods: Human HCC cells of the line SMMC7721 were cultured. LPA at different concentrations (2, 5, and 25 micromol/L) was added into the culture fluid. The Rho activity was detected with Rho activity detection kit. Western blotting was used to detect the protein expression of Rho. Adhesion test was conducted to calculate the adhesion percentage of the SMMC7721 cells. The invasion potential of the SMCC7721 cells was observed using transwell cell test.
Results: LPA at the concentrations of 5, and 25 micromol/L increases the activity of Rho protein. When the concentration of LPA was 25 micromol/L the activity of Rho protein was 400 times that of the control group (P < 0.01). The Rho protein expression in the SMCC7721 cells increased when stimulated by LPA, peaked 20 approximately 25 hours after stimulation, and then gradually decreased. When the concentration of LPA was 25 micromol/L the Rho protein expression level was 242% higher than that of the control group. LPA at the concentration of 5 micromol/L and over increased the migratory and invading potential of the SMCC7721 cells and increased the adhesiveness of the SMCC7721 cells time-dependently.
Conclusion: LPA increases the migratory and invading potential of HCC cells through Rho signal transduction pathway.