Measurement of spontaneous and therapeutic agent-induced apoptosis with BCL-2 protein expression in acute myeloid leukemia.
We have designed in vitro assays to investigate the possible association between apoptosis and chemotherapeutic sensitivity in acute myeloid leukemias (AMLs). Consistent low levels of spontaneous apoptosis were observed in myeloid cells from normal bone marrow samples, while untreated cells collected from 56 de novo AML patients showed variable apoptosis. Control myeloid cells showed increased apoptosis after in vitro treatments with daunomycin (DNR), cytosine arabinoside (ARA-C), or gamma irradiation (RAD). Most AML samples showed less treatment-associated apoptosis, suggesting that apoptosis responses to therapeutic agents may be frequently attenuated in AML. Certain cytogenetic abnormalities common in AML may affect apoptosis, as acute promyelocytic leukemia (APL) samples with t(15;17) karyotypes showed consistently low levels of spontaneous and treatment-associated apoptosis. Apoptosis assays may provide unique functional subtyping of AMLs, as other common cytogenetic subsets showed variable apoptosis. Altered function of two well-characterized regulators of apoptosis, BCL-2 and p53, was not entirely responsible for this variability. A genomic p53 mutation was found in only one AML sample. All samples that demonstrated the highest BCL-2-positive cell fractions showed low apoptosis, but reduced apoptosis was seen in both the presence and absence of BCL-2 overexpression. Finally, data from matched diagnosis and relapse sample pairs suggest that neither further reduced apoptosis nor additional BCL-2 overexpression is necessarily associated with disease progression.
Banker
D E
DE
Fred Hutchinson Cancer Research Center, Seattle, WA 98104, USA.
Groudine
M
M
Norwood
T
T
Appelbaum
F R
FR
D000208:Acute Disease; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects* / Q000528:radiation effects; D001853:Bone Marrow / Q000187:drug effects; D002469:Cell Separation; D003561:Cytarabine / Q000494:pharmacology; D003630:Daunorubicin / Q000494:pharmacology; D018450:Disease Progression; D005434:Flow Cytometry; D015973:Gene Expression Regulation, Leukemic / Q000187:drug effects*; D016158:Genes, p53; D006412:Hematopoietic Stem Cells / Q000187:drug effects / Q000528:radiation effects; D006801:Humans; D007951:Leukemia, Myeloid / Q000235:genetics / Q000473:pathology*; D009363:Neoplasm Proteins / Q000096:biosynthesis* / Q000235:genetics; D014411:Neoplastic Stem Cells / Q000187:drug effects / Q000528:radiation effects; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis* / Q000235:genetics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000528:radiation effects
D000970:Antineoplastic Agents; D009363:Neoplasm Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D003561:Cytarabine; D003630:Daunorubicin