Resistance to apoptosis in clinical melanoma gene therapy

描述（由申请人提供）：加州大学洛杉矶分校/加州理工学院工程免疫项目正在进行一系列使用F5 MART T细胞受体（TCR）工程T细胞的过继细胞治疗临床研究。表达这种高亲和力TCR的T淋巴细胞对HLA A*0201/ mart阳性黑色素瘤靶点具有高度的细胞毒性，释放I型细胞因子，并且在给药时具有非常高的生物学活性。在最近完成的一项试验中，8名患有转移性黑色素瘤的患者接受了109个F5 MART CTL治疗，其中6名患者在可测量的疾病部位（如肺、肝、骨、淋巴结和皮肤）显示出明显的肿瘤消退。然而，所有患者都在三个月内复发。我们的目标是研究来自这些患者的早期传代患者源性黑色素瘤细胞系以及两项后续试验对F5 MART ctl诱导的细胞毒性的敏感性或耐药机制。我们假设表观遗传控制的信号通路的解除调控激活和促凋亡和抗凋亡基因产物比例的不平衡有利于免疫抵抗表型。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确定表观遗传调节的信号转导途径和凋亡相关基因产物，负责黑色素瘤对F5 MART CTL的抗性。这最终导致了小分子抑制剂（增敏剂）的使用，这些抑制剂可以专门针对不受调节的信号通路的成分，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.