ABSTRACT
<p><b>OBJECTIVE</b>To investigate the role of Stat3 (one of the signal transductant and activator) signal transduction pathway in proliferation of vascular smooth muscle cells (VSMCs).</p><p><b>METHODS</b>VSMC was transfected with Stat3 antisense oligonucleotide. ELISA analysis was performed on Stat3 expression in cultured rat thoracic VSMC. Cell proliferation and toxicity assay by Methyl Thiazole (MTT) was used to measure the cell proliferation. The expression of Stat3, p-Stat3, Cyclin D1 and Bcl-x(L) were measured by Western blot.</p><p><b>RESULTS</b>Stat3 protein expression was positive in VSMC. Targeting of Stat3 using antisense oligonucleotide directed against the translation site, resulted in significant growth inhibition and downregulation of Stat3, p-Stat3 and Cyclin D1.</p><p><b>CONCLUSIONS</b>The increase of Stat3 correlates significantly with cell proliferation of VSMC. Cyclin D1 may be the critical target gene in mediating proliferation. Blocking Stat3 signal transduction pathway may inhibit the growth of VSMCs.</p>