神经肽P物质/NK-1R调控食管癌嗜神经浸润的机制研究

The Perineural invasion (PNI) of tumor is considered as a new manner of tumor metastasis, which indicates poor prognosis. Our previous studies confirmed that PNI could be found in about 55.56% esophageal squamous cell cancer (ESCC)，and ESCC cells could metastasize along the nerve in vitro and in vivo. Further studies showed that, in ESCC, there are many substance P immune positive nerve fibers, whose receptor, NK-1R, are highly expressed in ESCC. Substance P affects the tumor proliferation and metastasis through NK-1R. Previous studies indicated that substance P could affect the malignant tumor phenotype through NK-1R, but its fundamental mechanism is still unknown. In this study, we intend to emphasize on the following problems. 1. To find the relationship between the PNI of ESCC and SP immune positive nerve fibers and the NK-1R expression. 2. To confirm whether SP regulates the PNI of ESCC through its receptor NK-1R. 3. To demonstrate the fundamental mechanism of SP/NK-1R regulating the PNI of ESCC. Our study aims at illustrating the role of SP/NK-1R in nerve transmitted tumor-metastasis, a new tumor metastasis pathway, enriching the mechanism of PNI and providing new ideas and theories for tumor prevention and therapy.

肿瘤的嗜神经浸润被认为是一种新的肿瘤转移方式，预示患者预后较差。申请者前期研究证实，食管鳞癌的嗜神经浸润发生率为55.56%，并且通过体内外实验发现，食管鳞癌细胞可以沿着神经进行转移；进一步研究发现，食管癌中存在较多神经肽P物质免疫反应阳性的神经纤维，其受体NK-1R高表达于食管鳞癌组织和细胞中，P物质可通过NK-1R影响肿瘤的增殖和转移。既往报道指出，P物质可通过NK-1R影响肿瘤的恶性生物学表型，但其分子机制尚不清楚。本研究拟探讨以下问题：①明确食管癌嗜神经浸润与P物质阳性神经纤维和NK-1R表达之间的相关性；②探讨P物质是否通过其受体NK-1R调控食管癌的嗜神经浸润； ③阐明P物质/NK-1R调控食管癌嗜神经浸润的具体分子机制。本研究旨在揭示P物质/NK-1R在神经作为肿瘤转移的新途径中所发挥的作用，阐明嗜神经浸润的分子机制，为肿瘤的预防和治疗提供新的思路和理论依据。

嗜神经浸润是指肿瘤细胞侵入神经束内或包绕神经外周1/3以上，是肿瘤通过血管、淋巴及直接浸润转移之外的新途径。我们前期研究证实PNI可以影响食管癌的预后且食管癌组织中有SP阳性神经的存在。本研究中，我们利用食管癌病人的组织标本和大鼠背根神经节(DRG)体外3D共培养模型明确观察到PNI的现象及特点，结合临床资料证实PNI是食管癌患者复发和预后的独立危险因素。在构建的NK1R差异表达的食管癌细胞系中，通过平板克隆，transwell迁移和侵袭，划痕实验，MTT以及凋亡检测证实了NK1R在食管癌细胞的增殖，迁移和侵袭中发挥着重要作用，而对凋亡无明显影响。进一步通过蛋白质谱和生物信息学分析筛选了下游增殖相关分子Hes1和侵袭相关分子SMC4。构建了上述两个分子的差异表达细胞系并进行了表达和功能的检测，并在动物实验中加以验证，初步证实了SP/NK1R可能通过促进Hes1的过表达，提升食管癌细胞的增殖能力。SP/NK1R与SMC4的关系及其在PNI中的作用还有待于进一步研究。本研究明确了PNI在食管癌中的意义，探讨了SP/NK1R作为PNI的重要机制，及其在食管癌发生发展中发挥的作用，分析了其可能的下游分子通路，为食管癌的临床治疗提供了新的思路。