MOLECULAR DETERMINANTS OF GEMCITABINE (Franklin Hays)

全身化疗是肿瘤学家治疗不可切除的非小细胞肺癌（NSCLC）的剩余途径之一。不幸的是，非小细胞肺癌表明抗癌治疗不能提供显著的患者生存益处，并且有毒副作用。这些药物将延长转移性疾病的进展时间，但对降低非小细胞肺癌的死亡率几乎没有作用。当前建议的一个潜在主题是，通过对药物处置和反应的更详细的分子理解，可以显著改善非小细胞肺癌化疗。为了获得这一理解，我们将结合结构生物学和功能分析来研究与正常细胞和肿瘤细胞中吉西他滨摄取直接相关的人类整体膜蛋白。平衡核苷转运蛋白（hENT）家族广泛分布于人体组织中，已知可运输多种核苷抗代谢产物，并与化疗结果直接相关。我们在本提案中寻求解决的具体目标包括：(1)在原子分辨率下确定hENT的结构，(2)使用纯化蛋白开发体外功能分析，以及(3)使用三种人类肺癌细胞系表征hENT功能决定因素。这些研究的结果将被调整以确定hENT调节蛋白和治疗药物转运发生的分子基础。广泛的愿景是，这些新的分子见解可以推进临床结果，指导基于核苷的非小细胞肺癌药物治疗的治疗决策。

Systemic chemotherapy is one of the remaining avenues available to an oncologist treating unresectable non-small cell lung cancer (NSCLC). Unfortunately, NSCLC indicated anticancer therapeutics do not provide significant patient survival benefits and have toxic side effects. These drugs will extend the time-to-progression of metastatic disease by small margins yet do little to decrease NSCLC mortality. An underlying theme to the current proposal is that one can obtain significant improvements in NSCLC chemotherapy with a more detailed molecular understanding of drug disposition and response. To obtain this understanding we will use a combination of structural biology and functional assays to study a human integral membrane protein directly linked to gemcitabine uptake within normal and neoplastic cells. The equilibrative nucleoside transporter (hENT) family is broadly distributed in human tissues, is known to transport a wide array of nucleoside antimetabolites, and is directly linked to chemotherapeutic outcomes. Specific goals we seek to address in this proposal include (1) determine the structure of hENT at atomic resolution, (2) develop in vitro functional assays using purified protein, and (3) characterize hENT functional determinants using three human lung cancer cell lines. Outcomes from these studies will be tuned to determine the molecular basis by which hENT regulatoin and transport of therapeutics occus. The broad vision is that these novel molecular insights can be advanced to clinical outcomes that guide treatment decisions in nucleoside based drug treatment of NSCLC.