Abstract 3597: Association between the ABCG2 polymorphisms and the gefitinib-induced side effects in Japanese patients with non-small cell lung cancer

Abstract

Abstract ABCG2 is a half-size ATP-binding cassette transporter implicated in cellular gefitinib transport. Reportedly, the c.421C>A ABCG2 gene variant was associated with gefitinib-induced diarrhea in Caucasian patients with non-small cell lung cancer. c.421C>A ABCG2, resulting in p.Q141K substitution, is more prevalent in Asian populations. Therefore, the putative relationship between gefitinib-induced adverse effects and this functional polymorphism was investigated in 75 Japanese patients with non-small cell lung cancer treated with gefitinib 250 mg/d orally, and the results were correlated with treatment-related adverse effects. c.376 C>T, resulting in truncated, non-functional ABCG2, was also investigated. Forty one (54.7%) patients harbored 376T or 421A ABCG2 on at least one allele, while the remaining 34 (45.3%) were wild type for ABCG2. No significant group differences were observed in frequency of gefitinib-related diarrhea or other adverse effects. Next, DLD-1 colon cancer cells expressing wild-type (DLD-1/WT) or 141K mutant ABCG2 (DLD-1/Q141K) were established for investigation of in-vitro cell sensitivity to the ABCG2-substrate drugs, gefitinib and SN-38. ABCG2 expression was much lower in DLD-1/Q141K cells than in DLD-1/WT cells, despite similar ABCG2 mRNA levels. DLD-1/WT cells acquired more resistance to SN-38 than did DLD-1/Q141K cells, but neither cell line acquired gefitinib resistance compared with parental cells. In-vitro data also suggested that ABCG2 has only a limited role in toxicity of gefitinib, but not SN-38, in colon-derived cells. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3597.