SNAIL- and SLUG-induced side population phenotype of HCT116 human colorectal cancer cells and its regulation by BET inhibitors

• Published in: Biochemical and biophysical research communications Vol. 521; no. 1; pp. 152 - 157
• Main Authors: Kato, Yu, Kondo, Shingo, Itakura, Taira, Tokunaga, Miku, Hatayama, Shiori, Katayama, Kazuhiro, Sugimoto, Yoshikazu
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.01.2020
• Subjects: ABCG2; BCRP; BET inhibitors; Colorectal cancer; EMT; Side population cells; BCRP; Side population cells; EMT; Colorectal cancer; ABCG2; BET inhibitors
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2019.10.094

Epithelial-mesenchymal transition (EMT) is associated with cancer malignancies such as invasion, metastasis, and drug resistance. In this study, HCT116 human colorectal cancer cells were transduced with SLUG or SNAIL retroviruses, and EMT cells with mesenchymal morphology were established. The EMT cells showed a high invasive activity and resistance to several anticancer agents such as methotrexate, SN-38, and cisplatin. Furthermore, they contained about 1–10% side population (SP) cells that were not stained by Hoechst 33342. This SP phenotype was not stable; the isolated SP cells generated both SP and non-SP cells, suggesting a potential for differentiation. Gene expression analysis of SP cells suggested the alteration of genes that are involved in epigenetic changes. Therefore, we examined the effect of 74 epigenetic inhibitors, and found that two inhibitors, namely I-BET151 and bromosporine, targeting the bromodomain and extra-terminal motif (BET) proteins, decreased the ratio of SP cells to <50% compared with the control, without affecting the immediate efflux of Hoechst 33342 by transporters. In addition, compared with the parental cells, the EMT cells showed a higher sensitivity to I-BET151 and bromosporine. This study suggests that EMT development and SP phenotype can be independent events but both are regulated by BET inhibitors in SLUG- or SNAIL-transducted HCT116 cells. •SNAIL and SLUG induce EMT and drug resistance in human colorectal cancer cells.•The EMT cells contained 1–10% side population cells.•BET inhibitors decreased the ratio of side population cells.•The EMT cells showed higher sensitivity to BET inhibitors.