CD44 enhances adriamycin resistance in chronic myelogenous leukaemia cells K562.

Introduction To investigate CD44 effects on the adriamycin-resistant in chronic myelogenous leukaemia cells K562, we explored the role of CD44 in the K562 cells migration and apoptosis. Methods GeneChip® screening is used for elucidating various chemoresistance-related gene expression in the adriamycin-resistant leukaemia cells K562/ADR. We constructed K562/CD44 cells by transfection of an EGFP-SV40-CD44 plasmid, and adriamycin-resistant ability was confirmed by detecting migration and apoptosis-related proteins and mRNA expression using Western blotting and Real-time PCR respectively. Results K562/CD44 cells were generated by the transfection of an EGFP-SV40-CD44 plasmid with high CD44 expression. mRNA expression levels of CD44 and P-glycoprotein (P-gp), along with the proliferation rate, were increased, while the apoptosis rate of K562/CD44 cells was decreased. Migration-associated proteins such as MMP-2 and MMP-9 were upregulated, whereas apoptosis-related protein Bax was downregulated and Bcl-2 protein was not significantly altered in the K562/CD44 cells. Conclusions CD44 might be involved in adriamycin resistance via regulation of P-gp, MMP-2, MMP-9, and Bcl-2/Bax.