The Axis of CXCR4/SDF-1 Plays a Role in Colon Cancer Cell Adhesion Through Regulation of the AKT and IGF1R Signalling Pathways.

Abstract

Colorectal cancer (CRC) is the third most common cancer in the world. The high mortality of this tumor is mainly due to its invasive properties, as it forms metastases in multiple organs, preferentially in the liver. There has evidence showing that C-X-C chemokine receptor type 4 (CXCR-4) and its ligand, stromal cell-derived factor-1 (SDF-1), plays an important role in cancer progression and metastasis. However, the molecular mechanism underling the CRCR4-mediated CRC metastasis has not been well characterized. In this study, we aimed to investigate the roles of CXCR4 in colorectal cancer using the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9)-based genomic editing technique. We knocked-down CXCR4 using specific guide-RNA linked CRISPR/Cas9 in HT115 and COLO201 colon cancer cell lines which exhibited high levels of endogenous CXCR4 gene expression. Stable HT115 cells with CXCR4 knock-down were established by CRISPR plasmid transfection and validation was confirmed using T7 endonuclease 1 (T7EN1), flow cytometry (FACS) and western blotting assays. Knock-down of CXCR4 did not decrease proliferation of HT115 cells, but decreased the adhesion potential of cells to the human umbilical vein endothelial cells (HUVEC) and extracellular matrix. We further demonstrated that the AKT and type 1 insulin-like growth factor receptor (IGF1R) signalling pathways may be involved in the alteration of adhesion in CRC cells when CXCR4 is knocked down. Our data suggest that CXCR4 plays a key role in colorectal cancer progression via the mediation of tumor cell adhesion.