Aim: To evaluate the effects of adenovirus-mediated gene transfer of RhoA siRNA and RhoC siRNA on proliferation and invasion of SGC7901 cells by Rho/PI3K/Akt pathway.
Methods: Plasmid of RhoA siRNA and RhoC siRNA were constructed and transfected into SGC7901 cells. siRNA and LY294002 (PI3K inhibitor) were designed as the control group. The mRNA and protein expressions of RhoA and RhoC were respectively detected with RT-PCR and western blotting. In order to find out the changes of proliferation and invasion power of SGC7901 cell lines, we analyzed the data by MTT, Boyden chamber and evaluated apoptosis of cell with flow cytometry. We treated BALB/C nude mice with RhoA and RhoC-siRNA, and tumor control rate (%) in nude mice was calculated.
Results: RhoA and RhoC siRNA transfections specifically down-regulated the corresponding mRNA and protein levels in SGC7901 Cells. The experiment of permeated artificial basal membrane showed that the invasion power of SGC7901 cell lines are on the decline after treatment of Ad-RhoA and RhoC-siRNA (12.64 +/-3.27 vs 87.38 +/- 17.38, P < 0.05). The values of 490 nm wavelength light absorption were different in the five groups. The number of alive cells in the group of RhoA and RhoC-siRNA was lower than others in the 6(th) d (0.71 +/- 0.01 vs 3.82 +/- 0,11 P < 0.05). The apoptosis rate of transfected RhoA and RhoC-siRNA group with FACS were 19.07% +/- 1.78 and there were significant differences between treated and control groups (19.07 +/- 1.78% vs 1.23 +/- 0.11%, P < 0.01). The tumor transplantation experiment in BALB/C nude mice showed intratumoral injection of RhoA or RhoC siRNA can inhibit tumor growth.
Conclusion: RhoA and RhoC siRNA gene therapy mediated by adenovirus may be useful for inhibiting growth and invasion of SGC7901 through a PI3K/Akt pathway. These results provide a novel therapeutic target in preventing gastric cancer cell invasion and metastasis.