The effect of the dual Src/Abl kinase inhibitor AZD0530 on Philadelphia positive leukaemia cell lines.
BACKGROUND
Imatinib mesylate, a selective inhibitor of Abl tyrosine kinase, is efficacious in treating chronic myeloid leukaemia (CML) and Ph+ acute lymphoblastic leukaemia (ALL). However, most advanced-phase CML and Ph+ ALL patients relapse on Imatinib therapy. Several mechanisms of refractoriness have been reported, including the activation of the Src-family kinases (SFK). Here, we investigated the biological effect of the new specific dual Src/Abl kinase inhibitor AZD0530 on Ph+ leukaemic cells.


METHODS
Cell lines used included BV173 (CML in myeloid blast crisis), SEM t(4;11), Ba/F3 (IL-3 dependent murine pro B), p185Bcr-Abl infected Ba/F3 cells, p185Bcr-Abl mutant infected Ba/F3 cells, SupB15 (Ph+ ALL) and Imatinib resistant SupB15 (RTSupB15) (Ph+ ALL) cells. Cells were exposed to AZD0530 and Imatinib. Cell proliferation, apoptosis, survival and signalling pathways were assessed by dye exclusion, flow cytometry and Western blotting respectively.


RESULTS
AZD0530 specifically inhibited the growth of, and induced apoptosis in CML and Ph+ ALL cells in a dose dependent manner, but showed only marginal effects on Ph- ALL cells. Resistance to Imatinib due to the mutation Y253F in p185Bcr-Abl was overcome by AZD0530. Combination of AZD0530 and Imatinib showed an additive inhibitory effect on the proliferation of CML BV173 cells but not on Ph+ ALL SupB15 cells. An ongoing transphosphorylation was demonstrated between SFKs and Bcr-Abl. AZD0530 significantly down-regulated the activation of survival signalling pathways in Ph+ cells, resistant or sensitive to Imatinib, with the exception of the RTSupB15.


CONCLUSIONS
Our results indicate that AZD0530 targets both Src and Bcr-Abl kinase activity and reduces the leukaemic maintenance by Bcr-Abl.
Gwanmesia
Patricia Mambou
PM
Med, Klinik II/Abt, Hämatologie, Johann Wolfgang Goethe-Universität, 60590 Frankfurt, Germany. Mambou@uni-heidelberg.de
Romanski
Annette
A
Schwarz
Kerstin
K
Bacic
Biserka
B
Ruthardt
Martin
M
Ottmann
Oliver G
OG
D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D001549:Benzamides; D052117:Benzodioxoles / Q000008:administration & dosage / Q000494:pharmacology*; D048708:Cell Growth Processes / Q000187:drug effects; D045744:Cell Line, Tumor; D019008:Drug Resistance, Neoplasm; D004357:Drug Synergism; D016044:Fusion Proteins, bcr-abl / Q000096:biosynthesis; D006801:Humans; D000068877:Imatinib Mesylate; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000188:drug therapy* / Q000201:enzymology / Q000473:pathology; D010879:Piperazines / Q000008:administration & dosage / Q000494:pharmacology; D047428:Protein Kinase Inhibitors / Q000008:administration & dosage / Q000494:pharmacology; D016315:Proto-Oncogene Proteins c-abl / Q000037:antagonists & inhibitors* / Q000378:metabolism; D011743:Pyrimidines / Q000008:administration & dosage / Q000494:pharmacology; D011799:Quinazolines / Q000008:administration & dosage / Q000494:pharmacology*; D019061:src-Family Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism
D001549:Benzamides; D052117:Benzodioxoles; D010879:Piperazines; D047428:Protein Kinase Inhibitors; D011743:Pyrimidines; D011799:Quinazolines; D000068877:Imatinib Mesylate; C515233:saracatinib; D016044:Fusion Proteins, bcr-abl; D016315:Proto-Oncogene Proteins c-abl; D019061:src-Family Kinases