Abstract
Serine/arginine-rich (SR) proteins are a family of important splicing factors, which are involved in multiple aspects of RNA processing, including splicing, mRNA nuclear export, mRNA stability and translation. Previous studies have identified a number of SR proteins that exhibit abnormal expression in various tumor types. In the present study, the expression and function of serine/arginine-rich splicing factor 7 (SRSF7) were investigated in colon and lung cancer. Using tissue immunohistochemistry, it was observed that SRSF7 was overexpressed in colon and lung cancer tissues. As the role of SRSF7 in cancer remains to be fully elucidated, the expression of SRSF7 was knocked down in the present study by transfecting SRSF7-specific small interfering RNAs (siRNAs) into the HCT116 colon cancer cell line and A549 lung cancer cell line, which exhibited elevated expression of SRSF7. MTS assays, western blot analysis, flow cytometry and spectrofluorometer analyses were performed to assess the effects of SRSF7 knockdown on the proliferation and apoptosis of cells. The results demonstrated that the expression of SRSF7 was efficiently knocked down by SRSF7 siRNA, and that SRSF7 knockdown inhibited proliferation and enhanced apoptosis of HCT116 and A549 cells. Further experiments involving BEAS-2B cells stably overexpressing SRSF7, and A549 cells with stable knockdown of SRSF7 revealed that SRSF7 regulated the splicing of the apoptosis regulator Fas. Collectively, these data indicated that SRSF7 is critical for the survival of colon and lung cancer cells, and may be a potential therapeutic target for the treatment of colon and lung cancer.