Adaptive immunotherapy of anaplastic thyroid cancer

摘要 这项研究计划的目标是开发一种新的有效的过继免疫疗法， 低分化甲状腺癌的治疗，例如未分化甲状腺癌（ATC），或 低分化甲状腺癌（PDTC）;他们都有非常差的预后。这一目标 源于以下信息：i）没有有效的治疗方法可用于间变性 ii）我们首次发现ATC和PDTC甲状腺癌细胞表达 肿瘤抗原（TA）硫酸软骨素蛋白聚糖4（CSPG 4），其是一个有吸引力的靶点 的抗体为基础的免疫疗法;和iii）我们在我们的实验室可用的试剂 需要用T细胞开发未分化甲状腺癌的适应性免疫疗法 基因工程化以表达TA特异性嵌合抗原受体（CAR）。我们有 选择CAR T细胞作为效应细胞，因为这种策略允许快速产生多克隆T细胞， 具有TA特异性和有效细胞毒活性的细胞。值得注意的是，CAR T细胞已经 在实验环境中用于治疗甲状腺癌。使用的靶抗原是 ICAM1.因此，所获得的阳性结果不能转化为临床环境， ICAM 1在正常组织中广泛表达。我们选择CSPG 4作为目标， 由于该抗原在包括未分化甲状腺癌细胞的恶性细胞上高度表达， 但在正常组织中的分布有限。根据文献资料 根据我们自己的大量数据，CSPG 4只在活化的周细胞中检测到， 肿瘤微环境因此，预期CSPG 4的免疫靶向选择性地不 不仅抑制肿瘤细胞而且还将抑制肿瘤微环境中的新血管生成， 有助于消除甲状腺癌细胞，即使是那些不表达CSPG 4的细胞， 而没有与全身施用抗血管生成药物相关的副作用。 在初步实验中，我们发现CSPG 4 CAR T细胞可以识别甲状腺癌， 细胞，但它们在根除它们方面并不十分有效。我们认为，这些结果反映了 甲状腺癌细胞的逃逸机制。由于时间和资金有限， 通过RO 3赠款机制，在本提案中，我们计划获得一些信息，以支持 我们假设基于CSPG 4 CAR T细胞的免疫疗法是一种有效的治疗方法， ATC或低分化甲状腺癌（PDTC）的治疗。具体来说，我们将 确定CSPG 4在甲状腺癌中表达的频率和临床意义。PDTC 或ATC细胞系和人组织，并提供关于临床意义的数据。另外我们 计划测试CSPG 4 CAR T细胞的抗肿瘤活性是否可以通过策略增强 抵消甲状腺癌细胞利用的逃逸机制。

Abstract The goal of this research program is to develop a novel effective adoptive immunotherapy for the treatment of poorly differentiated thyroid cancers such as anaplastic thyroid cancer (ATC) or poorly differentiated thyroid cancer (PDTC); both of them have very poor prognoses. This goal stems from the following pieces of information: i) no effective therapy is available for anaplastic thyroid cancer, ii) we have found for the first time that ATC and PDTC thyroid cancer cells express the tumor antigen (TA) chondroitin sulphate proteoglycan 4 (CSPG4), which is an attractive target of antibody-based immunotherapy; and iii) we have available in our laboratory the reagents required to develop adaptive immunotherapy of undifferentiated thyroid cancer with T cells genetically engineered to express a TA-specific chimeric antigen receptor (CAR). We have selected CAR T cells as effector cells, since this strategy allows rapid generation of polyclonal T cells with TA-specificity and potent cytotoxic activity. It is noteworthy that CAR T cells have already been used for treatment of thyroid cancer in an experimental setting. The target antigen used is ICAM1. Therefore, the positive results obtained cannot be translated to a clinical setting given the broad expression of ICAM 1 in a number of normal tissues. We have selected CSPG4 as a target, since this antigen is highly expressed on malignant cells including anaplastic thyroid cancer cells, but has a restricted distribution in normal tissues. According to the information in the literature and according to our own extensive data, CSPG4 is only detectable on activated pericytes in the tumor microenvironment. As a result, immune targeting of CSPG4 is expected to selectively not only inhibit tumor cells but will also inhibit neo-angiogenesis in the tumor microenvironment, contributing to the elimination of thyroid cancer cells, even those which do not express CSPG4, without the side effects associated with the systemic administration of anti-angiogenic drugs. In preliminary experiments we have found that CSPG4 CAR T cells can recognize thyroid cancer cells, but they are not very effective in eradicating them. We believe that these results reflect the escape mechanisms utilized by thyroid cancer cells. Given the limited time and funding provided by the RO3 grant mechanism, in this proposal we plan to get some information which will support our hypothesis that CSPG4 CAR T cell based immunotherapy is a valid therapeutic approach for the treatment of ATC or poorly differentiated thyroid cancer (PDTC). Specifically, we will determine the frequency and clinical significance of CSPG4 expression in thyroid cancer. PDTC or ATC cell lines and human tissues and provide data on the clinical significance. In addition, we plan to test whether the antitumor activity of CSPG4 CAR T cells can be enhanced by strategies that counteract the escape mechanisms utilized by thyroid cancer cells.