siRNA-mediated snoRA42 suppression inhibits proliferation and self-renewal of CD133+ cells isolated from NSCLC cell lines. (A) There was a high level of expression of snoRA42 in CD133+ cells versus CD133- cells of a panel of NSCLC cells determined by qPCR analysis. (B) siRNA-snoRA42 efficiently reduced snoRA42 expression in CD133+ cells isolated from NSCLC cell lines. qPCR analysis was performed to determine snoRA42 expression in CD133+ cells treated with mock transfection, scrambled siRNA, or siRNA-snoRA42. (C) downregulation of snoRA42 decreased cell growth of CD133+ cells isolated from NSCLC cell lines. The time-kinetics of cell proliferation rate of CD133+ cancer cell with mock transfection, scrambled siRNA transfection, or siRNA-snoRA42 transfection was determined. Cell proliferation rate after snoRA42 knockdown in CD133+ cancer cells was significantly reduced after 24 hours. (D) snoRA42 knockdown reduced the percentage of mammospheres of CD133+ cells. The experiments were performed in all the NSCLC cell lines listed in Methods and had similar results. The number of cells used in each experiment can be found in Methods. The figure only shows results from H-1944- and Calu-1-derived CD133+ cells. *P values <0.05.