目的:顺铂是晚期非小细胞肺癌(NSCLC)一线治疗的核心化疗药物。然而,耐药性严重阻碍了其临床疗效。这项研究通过重新利用具有推定的组蛋白去乙酰化酶(HDAC)抑制作用的非肿瘤药物来研究顺铂耐药性的规避。
方法:通过一种名为“DRUGSURV”的计算药物再利用工具鉴定了一些临床批准的药物,并评估了HDAC抑制作用。三安令,最初表示为利尿剂,选择对亲本和顺铂耐药的NSCLC细胞系进行进一步研究。使用磺酰罗丹明B测定来评估细胞增殖。进行蛋白质印迹分析以检查组蛋白乙酰化。流式细胞术用于检测细胞凋亡和细胞周期效应。进行染色质免疫沉淀以研究转录因子与调节顺铂摄取和细胞周期进程的基因启动子的相互作用。在来自顺铂难治性NSCLC患者的患者来源的肿瘤异种移植物(PDX)中,进一步证实了氨苯蝶啶对顺铂耐药性的规避。
结果:发现氨苯蝶啶抑制HDAC。它被证明可以增强细胞顺铂的积累并增强顺铂诱导的细胞周期停滞,DNA损伤,和凋亡。机械上,发现氨苯蝶啶可诱导染色质中的组蛋白乙酰化,从而减少HDAC1的关联,但促进Sp1与hCTR1和p21基因启动子的相互作用。进一步显示氨蝶啶可增强顺铂在顺铂抗性PDX中的体内抗癌作用。
结论:研究结果主张进一步临床评估氨苯蝶啶的再利用以克服顺铂耐药。
OBJECTIVE: Cisplatin is the core chemotherapeutic drug used for first-line treatment of advanced non-small cell lung cancer (NSCLC). However, drug resistance is severely hindering its clinical efficacy. This study investigated the circumvention of cisplatin resistance by
repurposing non-oncology drugs with putative histone deacetylase (HDAC) inhibitory effect.
METHODS: A few clinically approved drugs were identified by a computational drug
repurposing tool called \"DRUGSURV\" and evaluated for HDAC inhibition. Triamterene, originally indicated as a diuretic, was chosen for further investigation in pairs of parental and cisplatin-resistant NSCLC cell lines. Sulforhodamine B assay was used to evaluate cell proliferation. Western blot analysis was performed to examine histone acetylation. Flow cytometry was used to examine apoptosis and cell cycle effects. Chromatin immunoprecipitation was conducted to investigate the interaction of transcription factors to the promoter of genes regulating cisplatin uptake and cell cycle progression. The circumvention of cisplatin resistance by triamterene was further verified in a patient-derived tumor xenograft (PDX) from a cisplatin-refractory NSCLC patient.
RESULTS: Triamterene was found to inhibit HDACs. It was shown to enhance cellular cisplatin accumulation and potentiate cisplatin-induced cell cycle arrest, DNA damage, and apoptosis. Mechanistically, triamterene was found to induce histone acetylation in chromatin, thereby reducing the association of HDAC1 but promoting the interaction of Sp1 with the gene promoter of hCTR1 and p21. Triamterene was further shown to potentiate the anti-cancer effect of cisplatin in cisplatin-resistant PDX in vivo.
CONCLUSIONS: The findings advocate further clinical evaluation of the
repurposing use of triamterene to overcome cisplatin resistance.