title: Proteomic investigation of taxol and taxotere resistance and invasiveness in a squamous lung carcinoma cell line.
abstract: Pulse selections on a chemotherapy naive squamous lung carcinoma cell line, SKMES-1, with clinically relevant concentrations of taxanes (taxol or taxotere) resulted in the development of a stable taxotere-resistant variant, SKMES-1-Taxotere and an unstable taxol-resistant variant, SKMES-1-Taxol. Both variants exhibited increased invasiveness in vitro. The unstable nature of SKMES-1-Taxol facilitated looking at factors involved in loss of taxol resistance and increased invasion. The taxotere and taxol-resistant cell lines were 5.9-fold and 12.5-fold resistant to taxotere and taxol respectively. Alterations in expression of/or point mutations in tubulin, the main target of taxanes, is a major mechanism or resistance. However, alterations in expression of beta tubulin were not consistent in the taxane-selected variants. Cross-resistance to adriamycin, vincristine and etoposide (VP-16) was consistent with overexpression of P-glycoprotein (P-gp). However, P-gp alone is not sufficient to confer the complete multiple drug resistance phenotype as all cell lines exhibited cross-resistance to 5-Fluorouracil (5-FU) and more than one mechanism has been linked to taxane resistance. There was no correlation between the fall of taxol resistance in SKMES-1-Taxol and P-gp expression indicating the loss in resistance to be independent of P-gp expression. Furthermore, resistance to the other drugs was not unstable in SKMES-1-Taxol suggesting some parallel mechanisms of resistance. Two-dimensional electrophoresis coupled with matrix assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry was used to identify alterations in expression of specific proteins associated with taxane resistance. A large number of differentially regulated proteins were identified in the resistant and invasive variants affecting cellular processes including stress response, protein turnover and cytoskeleton proteins.
authors.affiliation: National Institute of Cellular Biotechnology, Dublin City University, Glasnevin, Dublin 9, Ireland. Lisa.Murphy@dcu.ie
authors.forename: L
authors.initials: L
authors.lastname: Murphy
authors.forename: M
authors.initials: M
authors.lastname: Henry
authors.forename: P
authors.initials: P
authors.lastname: Meleady
authors.forename: M
authors.initials: M
authors.lastname: Clynes
authors.forename: J
authors.initials: J
authors.lastname: Keenan
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics / Q000378:metabolism; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism*; D002448:Cell Adhesion / Q000235:genetics / Q000502:physiology; D045744:Cell Line, Tumor; D000077143:Docetaxel; D019008:Drug Resistance, Neoplasm / Q000235:genetics / Q000502:physiology; D015180:Electrophoresis, Gel, Two-Dimensional; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism*; D009361:Neoplasm Invasiveness / Q000235:genetics / Q000503:physiopathology; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D017239:Paclitaxel / Q000494:pharmacology*; D040901:Proteomics; D017382:Reactive Oxygen Species / Q000378:metabolism; D043823:Taxoids / Q000494:pharmacology*
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000972:Antineoplastic Agents, Phytogenic; D009363:Neoplasm Proteins; D017382:Reactive Oxygen Species; D043823:Taxoids; D000077143:Docetaxel; D017239:Paclitaxel