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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2000-11-29
pubmed:abstractText
The 26S proteasome is a non-lysosomal multicatalytic protease complex for degrading intracellular proteins by ATP/ubiquitin-dependent proteolysis. Tightly ordered proteasomal degradation of proteins critical for cell cycle control implies a role of the proteasome in maintaining cell proliferation and cell survival. In this study, we demonstrate that cell-permeable proteasome inhibitors, lactacystin, benzyloxycarbonyl(Z)-leucyl-leucyl-leucinal (ZLLLal; MG-132) and 4-hydroxy-5-iodo-3-nitrophenylacetyl-leucyl-leucyl-leucine vinyl sulfone (NLVS), induce apoptosis abundantly in p53-defective leukemic cell lines CCRF-CEM, U937 and K562 as well as in myelogenic and lymphatic leukemic cells obtained from adult individuals with relapsed acute leukemias. Leukemic cell apoptosis induced by the proteasome inhibitors was dependent on activation of caspase-3 and related caspase family proteases, because caspase-3 inhibitor N-acetyl-L-aspartyl-L-glutamyl-L-valyl-L-aspartal (Ac-DEVD-cho) and, more effectively, the general caspase-inhibitor N-benzyloxycarbonyl-L-valyl-L-alanyl-L-aspartate fluoromethylketone (Z-VAD-fmk) were capable of blocking apoptosis induced by lactacystin, ZLLLal or NLVS. Induction of apoptosis by lactacystin or ZLLLal was accompanied by cell cycle arrest at G2/M phase and by accumulation and stabilization of cyclin-dependent kinase inhibitor p21WAF1/Cip and tumor suppressor protein p53. A role of p53 in mediating apoptosis or induction of p21WAF1/Cip1 was ruled out since CCRF-CEM and U937 cells express non-functional mutant p53, and K562 cells lack expression of p53. Viability and hematopoietic outgrowth of human CD34+ progenitor cells treated with lactacystin were slightly reduced, whereas treatment of CD34 + cells with ZLLLal or the cytostatic drugs doxorubicin and gemcitabine resulted in markedly reduced viability and hematopoietic outgrowth. These results demonstrate a basic role of the proteasome in maintaining survival of human leukemic cells, and may define cell-permeable proteasome inhibitors as potently anti-leukemic agents which exhibit a moderate hematopoietic toxicity in vitro.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Acetylcysteine, http://linkedlifedata.com/resource/pubmed/chemical/Antigens, CD34, http://linkedlifedata.com/resource/pubmed/chemical/CASP3 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/CDKN1A protein, human, http://linkedlifedata.com/resource/pubmed/chemical/Caspase 3, http://linkedlifedata.com/resource/pubmed/chemical/Caspases, http://linkedlifedata.com/resource/pubmed/chemical/Cyclin-Dependent Kinase Inhibitor..., http://linkedlifedata.com/resource/pubmed/chemical/Cyclins, http://linkedlifedata.com/resource/pubmed/chemical/Cysteine Proteinase Inhibitors, http://linkedlifedata.com/resource/pubmed/chemical/Enzyme Inhibitors, http://linkedlifedata.com/resource/pubmed/chemical/Leupeptins, http://linkedlifedata.com/resource/pubmed/chemical/Multienzyme Complexes, http://linkedlifedata.com/resource/pubmed/chemical/Neoplasm Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Tumor Suppressor Protein p53, http://linkedlifedata.com/resource/pubmed/chemical/benzyloxycarbonylleucyl-leucyl-leuci..., http://linkedlifedata.com/resource/pubmed/chemical/lactacystin
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0902-4441
pubmed:author
pubmed:issnType
Print
pubmed:volume
65
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
221-36
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:11073163-Acetylcysteine, pubmed-meshheading:11073163-Acute Disease, pubmed-meshheading:11073163-Adult, pubmed-meshheading:11073163-Antigens, CD34, pubmed-meshheading:11073163-Apoptosis, pubmed-meshheading:11073163-Caspase 3, pubmed-meshheading:11073163-Caspases, pubmed-meshheading:11073163-Cell Culture Techniques, pubmed-meshheading:11073163-Cell Cycle, pubmed-meshheading:11073163-Cell Division, pubmed-meshheading:11073163-Cyclin-Dependent Kinase Inhibitor p21, pubmed-meshheading:11073163-Cyclins, pubmed-meshheading:11073163-Cysteine Proteinase Inhibitors, pubmed-meshheading:11073163-Enzyme Inhibitors, pubmed-meshheading:11073163-Flow Cytometry, pubmed-meshheading:11073163-G2 Phase, pubmed-meshheading:11073163-Hematopoietic Stem Cells, pubmed-meshheading:11073163-Humans, pubmed-meshheading:11073163-K562 Cells, pubmed-meshheading:11073163-Leukemia, pubmed-meshheading:11073163-Leupeptins, pubmed-meshheading:11073163-Mitosis, pubmed-meshheading:11073163-Multienzyme Complexes, pubmed-meshheading:11073163-Neoplasm Proteins, pubmed-meshheading:11073163-Tumor Cells, Cultured, pubmed-meshheading:11073163-Tumor Suppressor Protein p53, pubmed-meshheading:11073163-U937 Cells
pubmed:year
2000
pubmed:articleTitle
Proteasome inhibitors induced caspase-dependent apoptosis and accumulation of p21WAF1/Cip1 in human immature leukemic cells.
pubmed:affiliation
Medizinische Klinik und Poliklinik mit Schwerpunkt Onkologie und Hämatologie, Universitäts-Klinikum Charité, Medizinische Fakultät der Humboldt-Universität Berlin, Germany. cord.naujokat@urz.uni-heidelberg.de
pubmed:publicationType
Journal Article