Publication Date:
2011-03-04
Description:
Microtubules have pivotal roles in fundamental cellular processes and are targets of antitubulin chemotherapeutics. Microtubule-targeted agents such as Taxol and vincristine are prescribed widely for various malignancies, including ovarian and breast adenocarcinomas, non-small-cell lung cancer, leukaemias and lymphomas. These agents arrest cells in mitosis and subsequently induce cell death through poorly defined mechanisms. The strategies that resistant tumour cells use to evade death induced by antitubulin agents are also unclear. Here we show that the pro-survival protein MCL1 (ref. 3) is a crucial regulator of apoptosis triggered by antitubulin chemotherapeutics. During mitotic arrest, MCL1 protein levels decline markedly, through a post-translational mechanism, potentiating cell death. Phosphorylation of MCL1 directs its interaction with the tumour-suppressor protein FBW7, which is the substrate-binding component of a ubiquitin ligase complex. The polyubiquitylation of MCL1 then targets it for proteasomal degradation. The degradation of MCL1 was blocked in patient-derived tumour cells that lacked FBW7 or had loss-of-function mutations in FBW7, conferring resistance to antitubulin agents and promoting chemotherapeutic-induced polyploidy. Additionally, primary tumour samples were enriched for FBW7 inactivation and elevated MCL1 levels, underscoring the prominent roles of these proteins in oncogenesis. Our findings suggest that profiling the FBW7 and MCL1 status of tumours, in terms of protein levels, messenger RNA levels and genetic status, could be useful to predict the response of patients to antitubulin chemotherapeutics.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Wertz, Ingrid E -- Kusam, Saritha -- Lam, Cynthia -- Okamoto, Toru -- Sandoval, Wendy -- Anderson, Daniel J -- Helgason, Elizabeth -- Ernst, James A -- Eby, Mike -- Liu, Jinfeng -- Belmont, Lisa D -- Kaminker, Josh S -- O'Rourke, Karen M -- Pujara, Kanan -- Kohli, Pawan Bir -- Johnson, Adam R -- Chiu, Mark L -- Lill, Jennie R -- Jackson, Peter K -- Fairbrother, Wayne J -- Seshagiri, Somasekar -- Ludlam, Mary J C -- Leong, Kevin G -- Dueber, Erin C -- Maecker, Heather -- Huang, David C S -- Dixit, Vishva M -- CA043540/CA/NCI NIH HHS/ -- CA80188/CA/NCI NIH HHS/ -- England -- Nature. 2011 Mar 3;471(7336):110-4. doi: 10.1038/nature09779.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Early Discovery Biochemistry, Genentech, South San Francisco, California 94080, USA. ingrid@gene.com〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21368834" target="_blank"〉PubMed〈/a〉
Keywords:
Animals
;
Apoptosis/drug effects
;
Cell Cycle Proteins/genetics/*metabolism
;
Cell Line
;
Cell Line, Tumor
;
Cell Transformation, Neoplastic/drug effects
;
Drug Resistance, Neoplasm
;
F-Box Proteins/genetics/*metabolism
;
Fibroblasts
;
Humans
;
Mice
;
Mitosis/drug effects
;
Myeloid Cell Leukemia Sequence 1 Protein
;
Paclitaxel/pharmacology
;
Pharmacogenetics
;
Phosphorylation/drug effects
;
Polyploidy
;
Proteasome Endopeptidase Complex/metabolism
;
Protein Binding/drug effects
;
Proto-Oncogene Proteins c-bcl-2/deficiency/genetics/*metabolism
;
RNA, Messenger/genetics/metabolism
;
Tubulin/*metabolism
;
Tubulin Modulators/*pharmacology
;
Ubiquitin-Protein Ligases/deficiency/genetics/*metabolism
;
Vincristine/pharmacology
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
Permalink
