EpCAM is critical for tumor proliferation and oxaliplatin chemoresistance in EpCAMhigh/CD44+ colorectal cancer stem cells

Abstract

Abstract Objectives A small subpopulation of colorectal cancer stem cells (CSCs) possess the ability to self-renew and the capacity to initiate the original tumor. EpCAMhigh/CD44+ cells are regarded as CSCs in colorectal cancer. The present study was undertaken to investigate the significance of EpCAM in the in vitro proliferation ability and oxaliplatin chemoresistance of EpCAMhigh/CD44+ colorectal CSCs. Methods We applied fluorescence-activated cell sorting (FACS) to separate the EpCAMhigh/CD44+ subset from human colorectal cancer cell line HCT116. We also used siRNA targeting EpCAM to create EpCAM−/CD44+ subpopulation. Then we compared EpCAMhigh/CD44+ cells and EpCAM−/CD44+ cells for proliferation ability and the chemoresistance to oxaliplatin by CCK8 assay. Results The EpCAMhigh/CD44+ subset comprises almost 6.25 ± 0.09% in cell line HCT116, and the EpCAM−/CD44+ cells displayed a significantly lower proliferation ability and weaker oxaliplatin chemoresistance than the EpCAMhigh/CD44+ cells. Conclusions EpCAM is critical for tumor proliferation and oxaliplatin chemoresistance in EpCAMhigh/CD44+ colorectal CSCs.