title: DNA repair protein levels vis-à-vis anticancer drug resistance in the human tumor cell lines of the National Cancer Institute drug screening program.
abstract: Nucleotide excision repair (NER) is a multi-enzyme DNA repair pathway in eukaryotes. Several NER genes in this pathway including XPB, XPD, XPA and ERCC-1 have been implicated in anticancer drug resistance in human tumor cells. In this study, we assessed the levels of the above-mentioned proteins in the NCI panel of 60 human tumor cell lines in relation to the cytotoxicity patterns of 170 compounds that constitute the standard agent (SA) database. The database consists of drugs used in the clinic for which a mechanism of action has been at least partially defined. The ERCC-1, XPD and XPB protein expression patterns yielded significant negative Pearson correlations with 13, 32 and 17 out of the 170 compounds, respectively (using p<0.05). XPA produced a random assortment of negative and positive correlations, and did not appear to confer an overall resistance or sensitivity to these drugs. Protein expression was also compared with a pre-defined categorization of the standard agents into six mechanism-of-action groups resulting in an inverse association between XPD and alkylating agent sensitivity. Our present data demonstrate that XPD protein levels correlate with resistance to alkylating agents in human tumor cell lines suggesting that XPD is implicated in the development of this resistance. NER activity, using the in vitro cell-free system repair assay, revealed no correlation between NER activity and the level of XPD protein in four cell lines with widely varying XPD protein levels. This lack of correlation may be due to the contribution of XPD to other functions including interactions with the Rad51 repair pathway.
authors.affiliation: Lady Davis Institute for Medical Research, Sir Mortimer B Davis-Jewish General Hospital, Montreal, Quebec H3T 1E2, Canada.
authors.forename: Zhiyuan
authors.initials: Z
authors.lastname: Xu
authors.forename: Zhong-Ping
authors.initials: ZP
authors.lastname: Chen
authors.forename: Areti
authors.initials: A
authors.lastname: Malapetsa
authors.forename: Moulay
authors.initials: M
authors.lastname: Alaoui-Jamali
authors.forename: Josée
authors.initials: J
authors.lastname: Bergeron
authors.forename: Anne
authors.initials: A
authors.lastname: Monks
authors.forename: Timothy G
authors.initials: TG
authors.lastname: Myers
authors.forename: Gérard
authors.initials: G
authors.lastname: Mohr
authors.forename: Edward A
authors.initials: EA
authors.lastname: Sausville
authors.forename: Dominic A
authors.initials: DA
authors.lastname: Scudiero
authors.forename: Raquel
authors.initials: R
authors.lastname: Aloyz
authors.forename: Lawrence C
authors.initials: LC
authors.lastname: Panasci
mesh_terms: D018906:Antineoplastic Agents, Alkylating / Q000494:pharmacology; D004265:DNA Helicases; D004260:DNA Repair / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D019008:Drug Resistance, Neoplasm / Q000235:genetics* / Q000502:physiology; D004720:Endonucleases; D005260:Female; D006801:Humans; D008297:Male; D009369:Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D011506:Proteins / Q000378:metabolism*; D014157:Transcription Factors; D014407:Tumor Cells, Cultured; D051760:Xeroderma Pigmentosum Group A Protein; D051759:Xeroderma Pigmentosum Group D Protein
chemical_list: D018906:Antineoplastic Agents, Alkylating; D004268:DNA-Binding Proteins; D011506:Proteins; D014157:Transcription Factors; C497314:XPA protein, human; D051760:Xeroderma Pigmentosum Group A Protein; C072022:XPBC-ERCC-3 protein; C071447:ERCC1 protein, human; D004720:Endonucleases; D004265:DNA Helicases; D051759:Xeroderma Pigmentosum Group D Protein; C497292:ERCC2 protein, human