title: Establishment of pemetrexed-resistant non-small cell lung cancer cell lines.
abstract: Pemetrexed (PEM), a multitargeted antifolate with manageable toxicity, is active against non-squamous non-small cell lung cancer; however, most patients eventually acquire resistance to PEM. To elucidate the resistant mechanism, we established PEM-resistant lung adenocarcinoma cell lines. Two parental cell lines, PC-9 and A549, were treated with step-wise increasing concentrations of PEM. Growth inhibition was determined by the 3-[4,5-dimethyl-thizol-2-yl]-2,5-diphenyltetrazolium bromide assay. Expression of the genes encoding thymidylate synthase (TS), dihydrofolate reductase (DHFR), and glycinamide ribonucleotide formyltransferase (GARFT) was analyzed by quantitative real-time reverse transcriptase polymerase chain reaction. The four PC-9 sublines were more resistant than the PC-9 cell line to PEM (2.2-, 2.9-, 8.4-, and 14.3-fold, respectively). The four A549 sublines also showed more resistance to PEM (7.8-, 9.6-, 42.3-, and 42.4-fold, respectively) than the parent cell line. All resistant sublines showed cross-resistance to cisplatin, but not to docetaxel, vinorelbine, 5-fluorouracil, or the active metabolite of irinotecan, SN-38. All PEM-resistant sublines expressed more TS than the parental cells, by polymerase chain reaction and Western blotting. DHFR was significantly increased in the four PEM-resistant A549 sublines. GARFT did not correlate with resistance to PEM. In summary, PEM-resistant cells remained sensitive to docetaxel, vinorelbine, 5-fluorouracil, and irinotecan. TS expression appeared to be associated with resistance to PEM.
authors: Department of Hematology, Oncology, and Respiratory Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama 700-8558, Japan.
authors: Dan
authors: D
authors: Zhang
authors: Nobuaki
authors: N
authors: Ochi
authors: Nagio
authors: N
authors: Takigawa
authors: Yasushi
authors: Y
authors: Tanimoto
authors: Yanyan
authors: Y
authors: Chen
authors: Eiki
authors: E
authors: Ichihara
authors: Katsuyuki
authors: K
authors: Hotta
authors: Masahiro
authors: M
authors: Tabata
authors: Mitsune
authors: M
authors: Tanimoto
authors: Katsuyuki
authors: K
authors: Kiura
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics / Q000378:metabolism; D000077192:Adenocarcinoma of Lung; D000970:Antineoplastic Agents / Q000494:pharmacology*; D002166:Camptothecin / Q000031:analogs & derivatives / Q000494:pharmacology; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics* / Q000378:metabolism*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002945:Cisplatin / Q000494:pharmacology; D000077143:Docetaxel; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D005472:Fluorouracil / Q000494:pharmacology; D005493:Folic Acid Antagonists / Q000494:pharmacology; D015870:Gene Expression; D005971:Glutamates / Q000494:pharmacology*; D006147:Guanine / Q000031:analogs & derivatives* / Q000494:pharmacology; D006801:Humans; D015151:Immunoblotting; D000077146:Irinotecan; D008175:Lung Neoplasms / Q000235:genetics / Q000378:metabolism; D000068437:Pemetrexed; D051026:Phosphoribosylglycinamide Formyltransferase / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D043823:Taxoids / Q000494:pharmacology; D013762:Tetrahydrofolate Dehydrogenase / Q000096:biosynthesis / Q000235:genetics; D013940:Thymidylate Synthase / Q000096:biosynthesis* / Q000235:genetics; D014747:Vinblastine / Q000031:analogs & derivatives / Q000494:pharmacology; D000077235:Vinorelbine
chemical_list: D000970:Antineoplastic Agents; D005493:Folic Acid Antagonists; D005971:Glutamates; D043823:Taxoids; D000068437:Pemetrexed; D000077143:Docetaxel; D014747:Vinblastine; D006147:Guanine; D000077146:Irinotecan; D013762:Tetrahydrofolate Dehydrogenase; D013940:Thymidylate Synthase; D051026:Phosphoribosylglycinamide Formyltransferase; D002945:Cisplatin; D000077235:Vinorelbine; D005472:Fluorouracil; D002166:Camptothecin