猕猴桃多糖通过抑制NF-κB通路干预胃癌上皮-间质转化的分子机制研究

Recent studies showed that gastric cancer invasion and metastasis was closely related to epithelial-mesenchymal transformation. The research group preliminary work confirms that the kiwifruit polysaccharide can extend the life expectancy of tumor-bearing mice, and inhibit the metastasis and differentiation of gastric cancer cells. This is coincided with the methods of strengthening the body resistance to eliminate pathogenic factors when treating tumors in Chinese medicine. To explicate the action effect of gastric cancer epithelial-mesenchymal transformation and its molecular mechanism, this subject intends to apply cell model and gastric cancer transplanted tumor model to define the function of kiwifruit polysaccharide inhibiting gastric cancer microenvironment TNF-α、IL-1β and the effects of anti-inflammatory and antioxidant caused by oxygen free radicals, while to verify the action effect of kiwifruit polysaccharide blocking the occurrence of gastric cancer EMT and reduce the action effect of gastric cancer migration and invasion, then preliminary clarifies its mechanism of inhibiting the action of PI3K/AKT/NF-κβ, the Ras / MAPK / NF-κβ pathway to prevent gastric cancer EMT occurrence. The completion of this subject can provide theoretical reference and experimental methods for research, development and clinical application in preventing and treating gastric cancer metastasis invasion by kiwifruit polysaccharide. It also provides a new direction in the mechanism research of controlling malignant tumors by the method of strengthening the body resistance to eliminate pathogenic factors in TCM.

近年研究发现胃癌浸润转移与上皮-间质转化密切相关。课题组前期工作研究证实，猕猴桃多糖能延长荷瘤小鼠生命，对胃癌细胞转移和分化具有抑制作用，这与中医治疗肿瘤扶正祛邪作用不谋而合,为了明确猕猴桃多糖抑制胃癌上皮-间质转化的作用效应及其相关分子机制，本课题拟应用细胞模型和胃癌移植瘤模型研究猕猴桃多糖抑制胃癌微环境TNF-α、IL-1β和氧自由基生成的抗炎抗氧化作用，验证猕猴桃多糖阻断胃癌EMT发生和下调胃癌细胞运动迁移和侵袭能力的作用效应，初步阐明其通过抑制PI3K/AKT/NF-κβ、Ras/MAPK/NF-κβ通路活化阻断胃癌EMT发生的作用机制。本项目完成可为猕猴桃多糖防治胃癌转移侵袭的研究开发和临床应用提供理论依据和实验方法，为中医药扶正祛邪法防治恶性肿瘤机理的研究提供了一个新方向。

近年研究发现胃癌浸润转移与上皮-间质转化(EMT)密切相关,肿瘤微环境高表达的TNF-α、IL-1β等炎性因子通过活化NF-κB通路，上调Snail-1等EMT相关因子、基质金属蛋白酶、血管黏附因子等的转录表达，促进EMT发生和肿瘤侵袭转移。猕猴桃根为清热解毒中药,临床常用于消化道肿瘤的治疗。项目组前期工作研究证实，猕猴桃多糖（DT）能延长荷瘤小鼠生命，对胃癌细胞转移和分化具有抑制作用。为进一步明确DT抑制胃癌EMT的作用及其相关分子机制，本项目应用Transwell、激光共聚焦、Western Blot、ELISA、定量PCR等方法技术，通过细胞模型明确了DT对胃癌细胞侵袭转移的抑制作用及其作用机制；通过裸鼠稳转luciferase基因的BGC823-luc胃癌原位移植瘤模型验证了DT抗胃癌转移的有效性及对EMT和胃癌转移的作用机制。研究结果表明，在体外DT能够抑制胃癌细胞的侵袭转移，该作用与调节EGF诱导的BGC-823细胞骨架蛋白F-actin和Vinculin表达，抑制胃癌细胞骨架形态改变，下调基质金属蛋白酶MMP2、黏附因子ICAM2、VCAM1、N-Cadherin及EMT相关Snail等mRNA转录和蛋白表达水平，抑制NF-κB p65通路活化有关。在体内，DT能显著降低人胃癌BGC823-luc原位移植瘤裸鼠血清TNF-α等炎症因子水平，缩小瘤体积，下调瘤组织金属基质蛋白酶、血管粘附因子及Snail、NF-κB等核转录因子的表达，抑制胃癌生长及侵袭转移。上述结果提示，DT抑制胃癌生长侵袭转移的作用是多方位，多层次的，体现了中医药特色。本项目的研究可极大促进特色抗肿瘤中药新药的研发，具有重要的社会意义。研究结果已在中草药等国内核心学术刊物上发表论文3篇；项目延伸研究获国家自然科学基金面上及青年项目2项；培养博士研究生3名，硕士研究生2名。