SLC7A5 Promotes Colorectal Cancer Progression by Regulating Cell Cycle and Migration

Abstract Background: Solute carrier family 7 member 5 (SLC7A5) was identified highly expressed and as a key participant in various tumor development; however, the role it played in colorectal cancer remains unclear. Methods and Results: In the current study, the expression of SLC7A5 were systematically mined in public databases and validated by real-time PCR in colon cancer and normal tissues. And then, the co-expression and pathway analysis got from public database, which indicated the potential influence of SLC7A5 for the etiology of colorectal cancer, were evaluated in the colon cancer cell lines by loss of SLC7A5 function experiment, flow cytometry, western blot, and wound healing assay. The results showed that the mRNA expression of SLC7A5 was significantly higher in colorectal cancer tissues than that in the non-tumor controls for GEO and TCGA datasets as well as 40 pairs of Xiangya clinical samples. The functional enrichment analysis based on public database showed that the pathways enriched most were cell cycle and epithelial-to-mesenchymal transition (EMT), and Cyclin D1 (CCND1) were the only gene that had a significant positive correlation with SLC7A5. Loss of SLC7A5 function in colon cancer cell lines could arrest cell cycle at G1 phase by down-regulating CCND1 and CDK2 protein expression, and may reduce cell migration by reversing EMT though upregulation of E-Cadherin and downregulation of zonula occludens-1. Conclusion: SLC7A5 is likely associated with the progression of colon cancer.