Background Decorin is a small leucine-rich proteoglycan and it plays an important role in regulation of cell growth and migration in various tumor cell lines. Decorin was found down-regulated in non-small cell lung cancer tissue and may be involved in regulation of lung cancer development. Methods In this study, lentivirus-mediated RNA interference and over expression were employed to change the expression levels of decorJn Jn lung cancer A549 cells. We tested the cell cycle of A549 cells and the expression of transforming growth factor （TGF）-[31, cyclin D1, epidermal growth factor receptor （EGFR）, P53, and P21. Results We found that up-regulation of decorin could inhibit proliferation, block cell cycle at G1 and decrease invasive activity of A549 cells. Moreover, we also show that up-regulation of decorin induced significant decreases of TGF-131, cyclin D1 expression, phosphorylation of EGFR, and increases of P53 and P21 expression. Opposite results were observed in A549 cells with down-regulation of decorin. Conclusion Our results suggest that decorin is a key regulator involved in proliferation and migration ofA549 cells.
