[Effect of bortezomib on the drug sensitivity of imatinib resistant K562/G01 cells].

OBJECTIVE: To explore the effect of bortezomib (BOR) on the drug sensitivity of imatinib-resistant chronic myeloid leukemia cell line K562/G01 cell and its mechanism. METHODS: MTT assay was used to detect the inhibition effect of cell growth, flow cytometry to cell cycle, and real time-PCR to the expression of COX-2 and mdr1 mRNA. RESULTS: Combination of 10 and 20 nmol/L BOR with imatinib could significantly enhance the sensitivity of K562/G01 to imatinib, the reverse factor was 1.83 and 2.72-fold respectively. Cell cycle arrested at G(2)/M phase could be observed by flow cytometry on BOR treatment. The over-expression of COX-2 and mdr1 could be down-regulated by BOR. CONCLUSIONS: BOR can enhance the imatinib sensitivity of imatinib resistant K562/G01 cell. The mechanism may be related to cell cycle phase arrested at G2/M and down-regulation of COX-2 and mdr1 expression.