Resistance to apoptosis in clinical melanoma gene therapy

描述（由申请人提供）：UCLA/Caltech工程免疫项目正在使用F5 MART T细胞受体（TCR）工程T细胞进行一系列过继细胞治疗临床研究。经工程改造以表达这种高亲和力TCR的T淋巴细胞对HLA A*0201/MART阳性黑素瘤靶标具有高度细胞毒性，释放I型细胞因子，并且当施用于患者时具有非常高的生物活性。在最近完成的一项试验中，将109个F5 MART CTL给予8名患有转移性黑色素瘤的条件患者，6名患者显示出在可测量的疾病部位如肺、肝、骨、淋巴结和皮肤中显著的肿瘤消退的证据。然而，所有人都在三个月内复发。我们的目的是研究这些患者的早期传代患者源性黑色素瘤细胞系对F5 MART CTL诱导的细胞毒性的敏感性或抗性机制，以及两项后续试验。我们假设，表观遗传控制的信号通路的激活失调和比例的不平衡的促凋亡和抗凋亡基因产物有利于免疫耐药表型。此外，获得性和/或固有抗性可以通过染色质重塑分子如HDACi（SAHA）逆转。成功执行所提出的特定目标将鉴定表观遗传学调节的信号转导途径和负责黑素瘤对F5 MART CTL的抗性的凋亡相关基因产物。这最终导致利用小分子抑制剂（敏化剂），其可以特异性靶向失调信号传导途径的组分，并通过调节凋亡相关基因产物的表达谱，有利于促凋亡环境，从而赋予敏感表型。

DESCRIPTION (provided by applicant): The UCLA/Caltech Program in Engineered Immunity is conducting a series of adoptive cell therapy clinical investigations using F5 MART T cell receptor (TCR) engineered T cells. T lymphocytes engineered to express this high affinity TCR are highly cytotoxic towards HLA A*0201/ MART-positive melanoma targets, release type I cytokines and are biologically very active when administered to patients. In a recently completed trial in which 109 F5 MART CTL were administered to 8 conditioned patients with metastatic melanoma, 6 showed evidence of dramatic tumor regression in measurable disease sites such as lung, liver, bone, lymph node and skin. All however, relapsed within three months. Our objective is to study the mechanism of sensitivity or resistance of early passage patient-derived melanoma cell lines from these patients, and from two successor trials, to F5 MART CTL-induced cytotoxicity. We hypothesize that epigenetically controlled deregulated activation of signaling pathways and an imbalance in the ratio of pro- and anti-apoptotic gene products favor an immune-resistant phenotype. Further, the acquired and/or inherent resistance can be reversed by chromatin remodeling molecules such as HDACi (SAHA). Successful execution of the proposed specific aims will identify epigenetically regulated signal transduction pathway(s) and apoptosis-associated gene products responsible for melanoma resistance to F5 MART CTL. This culminates in the utilization of small molecule inhibitors (sensitizing agents) that can specifically target the components of deregulated signaling pathways and by modulating the expression profile of apoptosis-related gene products favor a pro-apoptotic milieu, thus, conferring a sensitive phenotype.