Knockdown of stromal interaction molecule 1 inhibits proliferation of colorectal cancer cells by inducing apoptosis

Stromal interaction molecule 1 (STIM1) is an endoplasmic reticulum Ca(2+) sensor which has been reported to be overexpressed in numerous types of cancer, and is involved in the cell proliferation, invasion, migration and metastasis frequently observed in cancer. However, the role of STIM1 in colorectal cancer (CRC) remains unknown. The purpose of the present study was to investigate the effect of STIM1 in human CRC. The expression of STIM1 was specifically knocked down using lentivirus-mediated small hairpin RNA (shRNA) interference techniques in the CRC cell lines HCT116 and SW1116. Subsequently, the efficiency of infection was confirmed using green fluorescent protein (GFP)-positive signals. The knockdown efficiency was further determined using the reverse transcription-quantitative polymerase chain reaction and western blotting analysis. As a result, CRC cell lines with STIM1 silenced were successfully constructed and subsequently employed in a series of cell function assays. Knockdown of STIM1 significantly suppressed cell proliferation and colony formation, as revealed by an MTT and colony formation assay. Furthermore, it was identified that STIM1 silencing may promote cell apoptosis through the induction of mitochondria-associated apoptosis, as was identified by increased expression levels of B-cell lymphoma 2 (Bcl-2)-associated death promoter, Bcl-2-associated X protein and poly(ADP-ribose) polymerase cleavage. Therefore, STIM1 may serve a critical role in the progression of CRC by regulating cell proliferation and apoptosis, which may provide a potential therapeutic target for the treatment of CRC.