基于骨髓源性内皮祖细胞研究机体化疗后对结肠癌肺转移的影响及肠胃清的作用

Chemotherapy is one of the major therapeutic methods of advanced colorectal cancer. Nevertheless, while chemotherapy could inhibit the tumor growth, it will induce chemoresistance and may promote metastasis. Hence, the mechanism of metastatic favorable microenvironment after chemotherapy is increasingly attracting the attention of people. Previous researches have indicated that Chinese herbal compound ‘Changweiqing’ could improve the quality of life and prolong survival in the advanced colorectal cancer patients who undergo chemotherapy, but little is known about the mechanism which involves improving the therapeutic efficacy. This research is focused on the reaction of endothelial progenitor cells (EPCs) to chemotherapy and discuss the relationship between the reaction of EPCs to chemotherapy and lung metastasis. To study the effects of ‘Changweiqing’ on lung metastasis from colon cancer after chemotherapy, as well as on the EPCs bone marrow mobilization, the homing of tumor cells and biological functions. The present study aims to investigate the synergistic anti-tumor effects of ‘Changweiqing’ with cytotoxic chemotherapeutic agents from organic, histological, cellular and molecular levels. Through this research, it may find the efficacy enhancing mechanism when traditional Chinese herbal medicine combined with chemotherapy from adjusting the body’s microenvironment. And will provide new methods for Chinese herbal medicine against cancer

化疗是晚期结直肠癌重要的治疗手段。化疗在控制原发瘤生长的同时，也可诱导肿瘤耐药的形成，促进肿瘤的转移。化疗促进肿瘤转移的微环境机制日益受到人们的重视。前期研究表明，具有健脾理气化湿解毒作用的中药复方肠胃清可改善晚期结直肠化疗患者生活质量，延长生存期，但其增效机制有待进一步阐明。本研究拟从化疗后骨髓源性内皮祖细胞反应为切入点，探讨结肠癌化疗后骨髓源性内皮祖细胞反应与肺转移之间的关系，研究肠胃清对化疗后结肠癌肺转移的影响以及对骨髓源性内皮祖细胞骨髓动员、肿瘤归巢的作用，从器官、组织、细胞、分子水平研究肠胃清方化疗的增效机制。本研究从调整化疗后机体微环境的角度研究中医药化疗增效的作用，将为阐明中医药抗肿瘤作用机理提供新的思路。

目的：化疗是晚期结直肠癌的主要治疗手段之一，但化疗在杀伤肿瘤的同时能引起机体反应，产生“反作用”，可促进肿瘤的转移。本课题从化疗后机体骨髓源性内皮祖细胞（EPCs）变化与肿瘤转移相关的角度，观察中药复方肠胃清对化疗后机体EPCs的调节作用，以及对化疗后结肠癌肺转移的影响，进一步阐明肠胃清化疗增效的作用机制。 .方法：利用慢病毒转染的方法构建细胞稳定株(CT26-Luc和MC38-RFP)，对BABL/c和C57BL/6小鼠腹腔一次性注射最大耐受剂量（MTD）的化疗药物，给药3天后尾静脉注射LUC-CT26和RFP-MC38，建立化疗后结肠癌肺转移模型。并利用小鼠骨髓移植、动物活体成像、流式细胞术、ELISA、免疫荧光、激光共聚焦等技术，观察肠胃清对化疗后结肠癌肺转移作用。 .结果： .1.实验研究表明，三种化疗药物5-Fu 、L-OHP 、CPT-11干预后均促进了实验小鼠结肠癌肺转移，三种化疗药中，L-OHP促转移力最强。 .2. 肠胃清减轻了化疗干预后小鼠的结肠癌肺转移并延长了小鼠的生存期，其中模型组中位生存期为23.5天，L-OHP组中位生存期为20天，CWQ+L-OHP组小鼠的中位生存期为25.5天。 .3. 肠胃清减少了化疗后肺转移灶微血管密度，模型组、L-OHP组、CWQ+L-OHP组的CD34-MVD值依次为：49.50±3.12 、60.75±4.60、 44.63±3.95。.4.肠胃清减少了化疗后肺转移灶内EPCs的募集归巢，同时EPCs内整合素β3，基质金属蛋白酶MMP2/9的表达减少。.5. 肠胃清降低了化疗后上升的血浆VEGF、SDF-1水平，减少了化疗后EPCs的动员。.结论：化疗后血浆VEGF、SDF-1值上升，促进了EPCs的动员、募集和归巢到肺转移瘤组织 ，增加了小鼠结肠癌肺转移，中药肠胃清干预能调控化疗后机体EPCs的变化，减轻化疗后肿瘤转移。