Abstract
The effect of ABT-737, a BH3-mimicking inhibitor for anti-apoptotic Bcl-2 and Bcl-XL, but not Mcl-1, against Bcr-Abl-positive (Bcr-Abl +) leukaemic cells was examined. ABT-737 potently induced apoptosis in Bcr-Abl+ chronic myeloid leukaemia (CML) cell lines and primary CML samples in vitro and prolonged the survival of mice xenografted with BV173 cells, a CML cell line. Higher expression of anti-apoptotic Bcl-2 proteins reduced cell killing by ABT-737 in each cell line, but there was no correlation between the sensitivities to ABT-737 and the specific expression patterns of Bcl-2 family proteins among cell lines. Thus, the cell killing effect of ABT-737 must be determined not only by the expression patterns of Bcl-2 family proteins but also by other mechanisms, such as high expression of Bcr-Abl, or a drug-efflux pump, in CML cells. ABT-737 augmented the cell killing effect of imatinib in Bcr-Abl+ cells with diverse drug-resistance mechanisms unless leukaemic cells harboured imatinib-insensitive Abl kinase domain mutations, such as T315I. The combination of homoharringtonine that reduces Mcl-1 enhanced the killing by ABT-737 strongly in Bcr-Abl+ cells even with T315I mutation. These results suggest that ABT-737 is a useful component of chemotherapies for CML with diverse drug-resistance mechanisms.
Original language | English (US) |
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Pages (from-to) | 181-190 |
Number of pages | 10 |
Journal | British Journal of Haematology |
Volume | 140 |
Issue number | 2 |
DOIs | |
State | Published - Jan 2008 |
Keywords
- ABT-737
- Bcr-Abl
- Chronic myeloid leukaemia
- Homoharringtonine
- Imatinib
ASJC Scopus subject areas
- Hematology