Silencing LY6K Suppresses CD44+ EpCAM+ HCT116 Human Colon Cancer Stem Cells Growth: Insights from In Vitro and In Vivo Evidence

Abstract

Lymphocyte antigen 6 complex, locus K (LY6K) is a putative oncogene in various human cancers, including colorectal cancer, where elevated expression is associated with poor prognosis. This study investigates the antitumor effects of LY6K in colon cancer stem cells (CCSCs) both in vitro and in vivo. EpCAM and CD44 surface markers were used to isolate CCSCs from HCT116 cells, and the expression of LY6K in CCSCs was analyzed by real-time PCR. RNA interference was used to silence LY6K to evaluate its potential role of LY6K on the proliferation, migration, invasion, and cell cycle of CCSCs. Functional assays, including MTS assays, flow cytometric analyses, Transwell migration and invasion assays, and a xenograft model, were used for analysis. The results revealed that LY6K was highly expressed in CCSCs. siRNA-mediated LY6K-silencing in CCSCs inhibited cell proliferation by inducing G1 phase cell cycle arrest and suppressed migration and invasion. In vivo, LY6K silencing effectively reduced tumor growth and extended survival in a mouse model. These findings suggest LY6K as a promising therapeutic target for eradicating CCSCs in colorectal cancer treatment.