靶向阻断TGF-β/smad通路的效应性T细胞抑制肾癌干细胞增殖转移研究

Studies have shown that renal cancer stem cells(CSCs) maybe the sources of tumor recurrence and metastasis, and TGF-β plays important role in this procedure ,but the exact mechanism is unclear. Our previous studies have found that blockade TGF-β/smad pathway in CD8+ T cells could effectively kill tumor cells, inhibit pulmonary metastasis. However, whether this strategy work effectively in treatment of CSC and which mechanism involved remains unclear. Based on this, we hypothesize that blocking TGF-β/Smad pathway in effector CD8+ T cells could migrate to CSC niche directly, inhibit CSC proliferation and metastasis by interfering with its epithelial-mesenchymal transition. In the present study,we will isolate tumor-specific CD8+T cells from RCC patients, siRNA-targeted silence its TGF-β/smad pathway, and subsequently tested their antitumor responses in renal CSC in vitro .By using the SCID mouse model humanized with PBMC from RCC patients,we could adoptive transfer this effector CD8+T cells , simulate the patient's immune system responses, explore the its exact mechanism in anti-CSCs proliferation and metastasis in vivo. This further study, based on previous studies, is closer to clinical application.Furthermore, study may offer the promise of a novel therapeutic option and new target for the treatment of human patients with RCC.

研究表明，肾癌干细胞（CSC）是肿瘤复发转移的根源，其中TGF-β在CSC的侵袭转移中具有重要作用，但其确切机制不明。我们前期研究发现，阻断TGF-β/smad通路的效应性CD8+T细胞能有效杀伤肾癌细胞，抑制肺转移。但是，这种CD8+T细胞对肾癌CSC是否同样有靶向杀伤作用，其可能机制如何，目前尚不清楚。本课题根据前期研究基础，推测"阻断TGF-β/Smad通路的效应性T细胞可以定向迁移至CSC微环境，通过干扰其EMT作用，抑制CSC增殖转移"。本研究拟通过分离肾癌患者效应性CD8+T细胞，siRNA靶向沉默其TGF-β/Smad通路表达，分选肾癌干细胞使人源化小鼠成瘤，输注阻断TGF-β/Smad通路的效应性CD8+T细胞，模拟患者体内免疫系统应答，进行体内外抗CSC增殖转移研究。此研究是前期工作的深入，又更贴近临床应用，课题的实施有望为肾癌治疗提供新思路和药物新靶点。

肿瘤干细胞（CSC）是肿瘤复发和转移的根源，其中转化生长因子（TGF-β/smad）通路在CSC 的侵袭转移中具有重要作用，我们前期研究证实阻断转化生长因子(TGF-β)通路的淋巴毒细胞可以有效杀伤肿瘤细胞，抑制肺转移，但其对肾癌CSC作用尚不明确。本课题通过建立肾癌原代细胞筛选CD105+的肾癌肿瘤干细胞（CSC），利用人源化小鼠模型模拟体内环境免疫应答，用CSC使人源化小鼠成瘤后输注阻断TGF-β/Smad 通路的效应性CD8+T 细胞，采用免疫组化，实时定量PCR、Western blot，动物荧光成像等方法观察其抗肿瘤作用，发现这种肿瘤特异性效应性CD8+T细胞可以通过阻断肿瘤细胞的上皮-间质组织转化（EMT）作用发挥其靶向杀伤作用，抑制肺转移，为肾癌免疫治疗提供新思路和实验依据。