Regulatory role and mechanism of mitochondrial ribosomal protein S35 in proliferation, invasion, and migration of colon cancer cells

Objective To investigate the regulatory role and mechanism of mitochondrial ribosomal protein S35 (MRPS35) in the proliferation, invasion, and migration of colon cancer cells. Methods A total of 120 colon cancer tissues and adjacent normal tissues from patients undergoing radical resection for colon cancer were collected. Human colon cancer cell lines (HCT116, SW480, SW620) and a human normal colon epithelial cell line (NCM460) were cultured. Bioinformatics analysis, real-time quantitative polymerase chain reaction, Western blot, immunohistochemical (IHC) analysis, and cellular functional experiments (plate clone formation assay, scratch test, Transwell migration assay, CCK-8 cell viability assay) were conducted to evaluate the expression and regulatory mechanism of MRPS35 in colon cancer. Results Bioinformatics analysis showed that the expression level of the MRPS35 gene was higher in colorectal cancer tissues than in adjacent normal tissues (P<0.05). The relative expression levels of MRPS35 mRNA and MRPS35 protein were higher in human colon cancer cell lines (HCT116, SW480, SW620) than in NCM460 cells (P<0.05). The relative expression level of MRPS35 protein was higher in colon cancer tissues than that in adjacent normal tissues (P<0.05). The expression level of MRPS35 was significantly correlated with tumor diameter, tumor differentiation, and T stage (P=0.002, 0.021, 0.036). Patients with high MRPS35 expression had a higher overall survival rate than those with low MRPS35 expression (Log-rank P=0.015). After knockdown of MRPS35, the abilities of colon cancer cell cloning, proliferation, invasion, and migration were significantly enhanced. Furthermore, the expression of Wnt1, β-Catenin, and their downstream target proteins increased significantly after MRPS35 knockdown. Conclusion MRPS35 is significantly overexpressed in both colon cancer tissues and colon cancer cells, and it may inhibit the occurrence and development of colon cancer by regulating the Wnt/β-Catenin signaling pathway. Therefore, MRPS35 has the potential to become a novel biomarker and therapeutic target for colon cancer.