title: MCL-1-dependent leukemia cells are more sensitive to chemotherapy than BCL-2-dependent counterparts.
abstract: Myeloid cell leukemia sequence 1 (MCL-1) and B cell leukemia/lymphoma 2 (BCL-2) are anti-apoptotic proteins in the BCL-2 protein family often expressed in cancer. To compare the function of MCL-1 and BCL-2 in maintaining cancer survival, we constructed complementary mouse leukemia models based on Emu-Myc expression in which either BCL-2 or MCL-1 are required for leukemia maintenance. We show that the principal anti-apoptotic mechanism of both BCL-2 and MCL-1 in these leukemias is to sequester pro-death BH3-only proteins rather than BAX and BAK. We find that the MCL-1-dependent leukemias are more sensitive to a wide range of chemotherapeutic agents acting by disparate mechanisms. In common across these varied treatments is that MCL-1 protein levels rapidly decrease in a proteosome-dependent fashion, whereas those of BCL-2 are stable. We demonstrate for the first time that two anti-apoptotic proteins can enable tumorigenesis equally well, but nonetheless differ in their influence on chemosensitivity.
authors: Department of Medical Oncology, Dana Farber Cancer Institute, Boston, MA 02052, USA.
authors: Joslyn K
authors: JK
authors: Brunelle
authors: Jeremy
authors: J
authors: Ryan
authors: Derek
authors: D
authors: Yecies
authors: Joseph T
authors: JT
authors: Opferman
authors: Anthony
authors: A
authors: Letai
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000235:genetics / Q000502:physiology; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism; D000072224:Bcl-2-Like Protein 11; D004195:Disease Models, Animal; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D016259:Genes, myc; D006207:Half-Life; D007938:Leukemia / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D008223:Lymphoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D064549:Myeloid Cell Leukemia Sequence 1 Protein; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D025521:Tumor Suppressor Proteins / Q000378:metabolism
chemical_list: D051017:Apoptosis Regulatory Proteins; D000072224:Bcl-2-Like Protein 11; C000606776:Bcl2l11 protein, mouse; C579094:Mcl1 protein, mouse; D008565:Membrane Proteins; D064549:Myeloid Cell Leukemia Sequence 1 Protein; C488588:PUMA protein, mouse; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D025521:Tumor Suppressor Proteins