Data_Sheet_1_Establishment and Characterization of a Topotecan Resistant Non-small Cell Lung Cancer NCI-H460/TPT10 Cell Line.pdf

While topotecan (TPT) is a first- and second-line chemotherapeutic drug in treating lung cancer, the development of drug resistance in tumors still reserves as a major obstacle to chemotherapeutic success. Therefore, a better understanding of the mechanisms of topotecan resistance is critical. In this study, the first topotecan-resistant human non-small cell lung cancer (NSCLC) cell line, termed NCI-H460/TPT10, was established from the parental NCI-H460 cell line. NCI-H460/TPT10 cells exhibited a 394.7-fold resistance to TPT, and cross-resistance to SN-38, mitoxantrone, and doxorubicin, compared to parental NCI-H460 cells. Overexpression of ABCG2 localized on the cell membrane, but not ABCB1 or ABCC1, was found in NCI-H460/TPT10 cells, indicating that ABCG2 was likely to be involved in topotecan-resistance. This was confirmed by the abolishment of drug resistance in NCI-H460/TPT10 cells after ABCG2 knockout. Moreover, the involvement of functional ABCG2 as a drug efflux pump conferring multidrug resistance (MDR) was indicated by low intracellular accumulation of TPT in NCI-H460/TPT10 cells, and the reversal effects by ABCG2 inhibitor Ko143. The NCI-H460/TPT10 cell line and its parental cell line can be useful for drug screening and developing targeted strategies to overcome ABCG2-mediated MDR in NSCLC.

拓扑替康（topotecan, TPT）是治疗肺癌的一线及二线化疗药物，但肿瘤耐药性的产生仍是制约化疗疗效的主要障碍。因此，深入解析拓扑替康耐药的分子机制具有重要意义。本研究从亲本NCI-H460细胞系中构建出首个拓扑替康耐药的人非小细胞肺癌（non-small cell lung cancer, NSCLC）细胞系，命名为NCI-H460/TPT10。与亲本NCI-H460细胞相比，NCI-H460/TPT10细胞对TPT的耐药倍数达394.7倍，且对SN-38、米托蒽醌及多柔比星表现出交叉耐药性。研究发现，NCI-H460/TPT10细胞中定位于细胞膜的ABCG2呈现过表达状态，而ABCB1与ABCC1无此类变化，提示ABCG2可能参与拓扑替康耐药过程。这一结论通过ABCG2基因敲除后NCI-H460/TPT10细胞的耐药性被消除得到验证。此外，NCI-H460/TPT10细胞内TPT的细胞内蓄积水平较低，且ABCG2抑制剂Ko143可逆转其耐药性，进一步证实了功能性ABCG2作为药物外排泵介导多药耐药（multidrug resistance, MDR）的作用。该NCI-H460/TPT10细胞系及其亲本细胞系可用于药物筛选及开发靶向策略以克服非小细胞肺癌中ABCG2介导的多药耐药。