CHSY1 promoted proliferation and suppressed apoptosis in colorectal cancer through regulation of the NFκB and/or caspase-3/7 signaling pathway

Colorectal cancer is a commonly observed malignant cancer. However, the limited therapies for colorectal cancer do not bring much benefit for patients. Chondroitin synthase-1 (CHSY1) is an enzyme responsible for the biosynthesis of chondroitin sulfate and has been implicated in the tumorigenesis of several cancer types; however, there is limited information regarding the role of CHSY1 in colorectal cancer. In the present study, CHSY1 was demonstrated to be highly expressed in colorectal cancer tissues and in cell lines, and the CHSY1 expression level was associated with the 5-year survival rate of patients with colorectal cancer. Following CHSY1 knockdown, the proliferation of colorectal cancer cells was significantly decreased. The number of RKO cells decreased by 50% following CHSY1 knockdown compared with that in the control after culture for 5 days. However, the apoptosis rate of RKO cells increased to 14.15% after CHSY1 knockdown. In addition, the activity of caspase-3/7 was also enhanced. Furthermore, the expression of B-cell lymphoma 2 (Bcl-2) was reduced, whereas the levels of Bcl-2-associated X protein (Bax) and truncated caspase-3/7 were increased following CHSY1 knockdown. Additionally, the phosphorylation level of I kappa B and the expression of nuclear factor (NF)kappa B also decreased. In contrast, forced expression of CHSY1 increased the level of Bcl-2, NF kappa B, and phosphorylated I kappa B, whereas the level of bax and truncated caspase-3/7 decreased. Therefore, the data of the present study suggest that CHSY1 promoted cell proliferation by regulating NF kappa B signaling and suppressed cell apoptosis by regulating/caspase-3/7 signaling in colorectal cancer. The present study also suggests that CHSY1 may be a potential target for colorectal cancer therapy.