天花粉素调控上皮间质转化相关miRNAs表达抑制乳腺癌免疫逃逸的研究

Traditional Chinese medicines play an important role in combined therapy of tumor. Trichosanthes, which is an essential ingredient in Rukangtang, has soothing the liver, dryness, eliminating pathogens, relieving stagnation, descending Qinghuo sputum, its major active component prevent breast cancer relapse and regulate immune system. Immune escape is an important mechanism in tumor development, the accumulation of regulatory T cells in tumor micro-environment and epithelial-mesenchymal transition in tumor cells are critical steps in tumor immune escape. The EMT-miRNAs are the critical factors in regulation Treg proliferation and immune escape. Traditional treatment (surgery, radiotherapy and chemotherapy) could promote recurrence under inflammatory factor treatment, instead of the prevention of immune escape. Former studies had demonstrated TCS could regulate the EMT-associated miRNAs expression level in breast cell lines. Due to the important role of EMT-miRNAs in the regulation of immune escape and the differentiation and function of Treg, we proposed that TCS could intervene Treg proliferation and function, inhibits the tumor immune escape. This study is going to do some research on the impacts of TCS in Treg differentiation and function in tumor micro-environment, analyze the molecular mechanisms of TCS in the prevention of immune escape by RNAi in vivo and vitro, demonstrate the roles of TCS on immune therapy in breast cancer. The successful implementation of this study is helpful for the illustration of the anti-tumor mechanisms of TCS, and supply the experimental foundation for the exploration of new clinical indication for traditional medicine.

传统中药在肿瘤综合治疗中占有重要地位，天花粉是乳康汤方剂的重要成份，可疏肝润燥、祛邪、开郁结、降痰火，其活性成份--天花粉素（TCS）具有抑制乳腺癌复发及调节免疫的作用。免疫逃逸是肿瘤生长的重要机制之一，肿瘤上皮间质转化（EMT）及调节T细胞（Treg）均参与肿瘤免疫逃逸过程；EMT相关miRNAs是调控Treg细胞分化及免疫逃逸的关键分子。传统治疗乳腺癌的方法（手术、放疗、化疗）不仅无法抑制肿瘤免疫逃逸，相反在炎症因子作用下，诱导肿瘤复发。前期研究证明TCS可干预乳腺癌EMT相关miRNAs表达，提示TCS可能具有干预Treg细胞分化/功能，抑制肿瘤免疫逃逸的作用。本课题拟从体内及体外实验，分析TCS对肿瘤周围Treg细胞分化/功能的影响，并通过RNAi方法探讨TCS抑制乳腺癌免疫逃逸的分子机制。该课题的成功实施将进一步明确天花粉素的抗肿瘤作用，为传统中药开发新的临床适应症提供实验基础。

传统中药在肿瘤综合治疗中占有重要地位，天花粉是乳康汤方剂的重要成份，可疏肝润燥,祛邪，开郁结，降痰火，其活性成份——天花粉素（TCS）具有抑制乳腺癌复发及调节免疫的作用。免疫逃逸是肿瘤生长的重要机制之一，肿瘤上皮间质转化（EMT）及调节T细胞（Treg）均参与肿瘤免疫逃逸过程；EMT相关miRNAs是调控Treg细胞分化及免疫逃逸的关键分子。传统治疗乳腺癌的方法（手术、放疗、化疗）不仅无法抑制肿瘤免疫逃逸，相反在炎症因子作用下，诱导肿瘤复发。前期研究证明TCS可干预乳腺癌EMT相关miRNAs表达，提示TCS可能具有干预Treg细胞分化/功能，抑制肿瘤免疫逃逸的作用。本课题通过实验验证天花粉素具有抑制乳腺癌细胞E-cad低表达等功能，提示天花粉素可抑制乳腺癌的侵袭与转移，通过肿瘤细胞与淋巴细胞共培养，本课题发现天花粉素可抑制Treg细胞分化及功能；为进一步验证其可能机制，本课题通过miRNAs芯片技术筛选出天花粉素处理肿瘤细胞后miR4672表达升高，并进一步验证miR4672可以抑制肿瘤细胞的侵袭及转移，并对miR4672的启动子区域进行分析，推测miR4672宿主基因AK1的启动子区域的甲基化异常是导致天花粉素促进miR4672高表达的主要作用机理。该课题的实施将进一步明确天花粉素的抗肿瘤作用，为传统中药开发新的临床适应症提供实验基础。