Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
2008-8-8
pubmed:abstractText
Gefitinib (Iressa(R), ZD1839) is a selective epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor that blocks growth factor-mediated cell proliferation and extracellular signal-regulated kinases 1/2 (ERK1/2) signaling activation. Rad51 is an essential component of the homologous recombination repair pathway. High level of Rad51 expression has been reported in chemo- or radioresistant carcinomas. We hypothesized that gefitinib may enhance the effects of the alkylating agent cisplatin- or the antitumor antibiotic mitomycin C (MMC)-mediated cytotoxicity by decreasing ERK1/2 activation and Rad51 expression. Exposure of human non-small lung cancer cells to gefitinib decreased cisplatin- or MMC-elicited ERK1/2 activation and Rad51 protein induction. Neither cisplatin nor MMC treatment affected Rad51 messenger RNA (mRNA). However, gefitinib cotreatment with cisplatin or MMC significantly decreased Rad51 mRNA levels. In addition, gefitinib decreased cisplatin- or MMC-elicited Rad51 protein levels by increasing Rad51 protein instability. Enhancement of ERK1/2 signaling by constitutively active mitogen-activated protein kinase kinase 1/2 (MKK1/2-CA) increased Rad51 protein levels and protein stability in gefitinib and cisplatin or MMC cotreated cells. Moreover, the synergistic cytotoxic effects induced by gefitinib cotreatment with cisplatin or MMC were remarkably decreased by MKK1-CA-mediated enhancement of ERK1/2 activation. Depletion of endogenous Rad51 expression by si-Rad51 RNA transfection significantly enhanced lung cancer cell death upon treatment with cisplatin or MMC. We conclude that Rad51 protein protects lung cancer cells from synergistic cytotoxic effects induced by gefitinib and chemotherapeutic agents. Suppression of Rad51 expression may be a novel lung cancer therapeutic modality to overcome drug resistance to EGFR inhibitors and chemotherapeutic agents.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/ATP dependent 26S protease, http://linkedlifedata.com/resource/pubmed/chemical/Cisplatin, http://linkedlifedata.com/resource/pubmed/chemical/MAP Kinase Kinase 1, http://linkedlifedata.com/resource/pubmed/chemical/Mitogen-Activated Protein Kinase 1, http://linkedlifedata.com/resource/pubmed/chemical/Mitogen-Activated Protein Kinase 3, http://linkedlifedata.com/resource/pubmed/chemical/Mitomycin, http://linkedlifedata.com/resource/pubmed/chemical/Proteasome Endopeptidase Complex, http://linkedlifedata.com/resource/pubmed/chemical/Protein Kinase Inhibitors, http://linkedlifedata.com/resource/pubmed/chemical/Quinazolines, http://linkedlifedata.com/resource/pubmed/chemical/RAD51 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/RNA, Messenger, http://linkedlifedata.com/resource/pubmed/chemical/Rad51 Recombinase, http://linkedlifedata.com/resource/pubmed/chemical/Receptor, Epidermal Growth Factor, http://linkedlifedata.com/resource/pubmed/chemical/gefitinib
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
1460-2180
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
29
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1448-58
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:18544565-Antineoplastic Combined Chemotherapy Protocols, pubmed-meshheading:18544565-Carcinoma, Non-Small-Cell Lung, pubmed-meshheading:18544565-Cisplatin, pubmed-meshheading:18544565-Drug Synergism, pubmed-meshheading:18544565-Humans, pubmed-meshheading:18544565-Lung Neoplasms, pubmed-meshheading:18544565-MAP Kinase Kinase 1, pubmed-meshheading:18544565-MAP Kinase Signaling System, pubmed-meshheading:18544565-Mitogen-Activated Protein Kinase 1, pubmed-meshheading:18544565-Mitogen-Activated Protein Kinase 3, pubmed-meshheading:18544565-Mitomycin, pubmed-meshheading:18544565-Phosphorylation, pubmed-meshheading:18544565-Proteasome Endopeptidase Complex, pubmed-meshheading:18544565-Protein Kinase Inhibitors, pubmed-meshheading:18544565-Quinazolines, pubmed-meshheading:18544565-RNA, Messenger, pubmed-meshheading:18544565-Rad51 Recombinase, pubmed-meshheading:18544565-Receptor, Epidermal Growth Factor, pubmed-meshheading:18544565-Transfection
pubmed:year
2008
pubmed:articleTitle
Involvement of Rad51 in cytotoxicity induced by epidermal growth factor receptor inhibitor (gefitinib, IressaR) and chemotherapeutic agents in human lung cancer cells.
pubmed:affiliation
Department of Internal Medicine, Hsinchu Hospital, Department of Health, The Executive Yuan, Taiwan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't