CRIM1 is expressed at higher levels in drug-resistant than in drug-sensitive myeloid leukemia HL60 cells

Abstract

Aim: The aim of this study was to explore possible differences in the mRNA expression levels of CRIM1, SMAD5, BMP4 and BMP7 in sensitive (S) and multidrug-resistant (R0.5) myeloid leukemia HL60 cells.

Materials and methods: HL60S and HL60R0.5 cells were exposed to daunorubicin (DNR) or cytarabine (Ara-C).

Results: Baseline levels of CRIM1 were found to be 15-fold higher in HL60R0.5 than in HL60S. Sixteen hours of exposure to DNR resulted in a 5.6-fold increase in CRIM1 levels in HL60S. Exposure to either DNR or Ara-C resulted in modest increases in CRIM1 levels in HL60R0.5. Similarly, baseline levels of SMAD5 and BMP4 were higher in HL60R0.5 than in HL60S cells. Analysis of the drug SMAD5-resistance marker permeability-glycoprotein (Pgp) revealed that CRIM1 and Pgp exhibit a covariance pattern of expression.

Conclusion: This study demonstrated that CRIM1 is expressed at high levels in resistant leukemia cells, indicating that CRIM1 may play a role in drug-resistance.