The human myotubularin-related protein suppresses the growth of lung carcinoma cells.

Herein, we report that the human myotubularin-related protein (KIAA0371) induced growth suppression of lung cancer cells. Colony formation assays demonstrated that the exogenous expression of the human myotubularin-related gene induced a significant growth inhibition of H1299 cells in which the expression of the human myotubularin-related gene was undetectable. Colony formation of these cells was reduced by 39% after transfection with this gene, as compared with the control vector. Cells stably transfected with this gene showed a reduction in growth of 48% compared with those cells transfected with the empty vector. We also showed that this negative regulation of the myotubularin-related protein is correlated with cell-cycle arrest at G1. In addition, we found that the cyclin-dependent kinase inhibitor, p27, is induced by increased expression of the human myotubularin-related gene. These results suggest that the human myotubularin-related protein can negatively regulate the growth of lung cancer cells.