SPAG5 Promotes the Proliferation, Migration, Invasion, and Epithelial-Mesenchymal Transformation of Colorectal Cancer Cells by Activating the PI3K/AKT Signaling Pathway

Colorectal cancer (CRC) is a cancer that occurs in the rectum or colon with a high incidence. Sperm-associated antigen 5 (SPAG5), a gene that regulates cell division, has been observed highly expressed in a variety of cancers, but its role in CRC is unclear. This study aimed to investigate the regulatory role of SPAG5 in CRC. The expression of SPAG5 in multiple cancers and normal tissues was predicted by The Cancer Genome Atlas and Tumor Immune Estimation Resource, and the expression of SPAG5 in human normal intestinal epithelial cells NCM460 and human CRC cell lines Caco2, HT29, SW480, and LOVO was verified by western blotting (WB). The effects of silencing SPAG5 on cell viability, proliferation, and apoptosis were then investigated by cell counting kit-8, WB, and flow cytometry. The effects of silencing SPAG5 on cell migration and invasion were investigated by scratch assay and transwell assay. Finally, the phosphorylation levels of phosphoinositide 3-kinase (PI3K) and AKT in cells were detected by WB. The results showed that SPAG5 was highly expressed in CRC and was verified by WB. Silencing of SPAG5 inhibited cell viability and proliferation and increased the cell apoptosis rate. Furthermore, both cell invasion and migration abilities were suppressed by the low expression of SPAG5. Finally, WB results found that the phosphorylation levels of PI3K and AKT were reduced after SPAG5 silencing. In summary, the results showed that SPAG5 can promote the proliferation and invasion of CRC cells by targeting the PI3K/AKT signaling pathway.