RNA interference targeting α8 integrin attenuates smooth muscle cell growth

α8 integrin gene silencing has been shown to result in the stress fibre disassembly. Stress fibres are required for cell adhesion to promote passage through cell cycle. Thus, we hypothesized that α8 integrin gene silencing might affect vascular smooth muscle cell (VSMC) growth. Short interference RNA (siRNA) targeting α8 integrin in rat VSMCs resulted in reduced DNA synthesis. Moreover, siRNA-α8 integrin prevented thrombin-induced proliferation. RhoA plays a critical role in regulating VSMC growth. α8 integrin co-immunoprecipitated with RhoA and siRNA-α8 reduced membrane associated RhoA. Our data suggest that α8 integrin expression is critical for VSMC growth, which has potential implications in postangioplasty neointimal hyperplasia.