转染趋化因子MCP-3基因诱导抗小鼠大肠癌主动免疫

背景与目的:趋化因子对于免疫细胞在肿瘤组织中的浸润起重要作用,转染趋化因子基因在许多类型的肿瘤中诱导了抗肿瘤免疫反应,本研究的目的是通过将趋化因子单核细胞趋化蛋白-3(monocytechemotacticprotein-3,MCP-3)基因转染小鼠大肠癌CMT93瘤细胞,探讨MCP-3用于诱导抗大肠癌主动免疫的可行性。方法:用脂质体将小鼠MCP-3基因导入小鼠大肠癌细胞CMT93,G418筛选抗性克隆,RT-PCR检测MCP-3的表达,趋化实验检测MCP-3的活性,体内实验观察野生型及MCP-3基因修饰瘤细胞的致瘤性,组织病理学检测肿瘤中免疫细胞的浸润及肿瘤的转移。结果:RT-PCR检测发现G418筛选得到的转染MCP-3的抗性克隆(CMT93/MCP3)表达MCP-3,而野生型CMT93不表达MCP-3。趋化实验显示CMT93/MCP-3的培养上清具有良好的趋化活性,趋化指数达5.57(P<0.05),对照组培养上清均无趋化活性。体内成瘤实验显示:与野生型瘤细胞相比,CMT93/MCP-3的成瘤率没有显著性下降,但源于CMT93/MCP-3的肿瘤生长速度与对照组相比显著减慢(P<0.05)。在CMT93/MCP-3所形成肿瘤中有明显的免疫细胞浸润,对照组肿瘤中免疫细胞的浸润较少。接种CMT93/MCP-3瘤细胞的小鼠,肿瘤的转移受到了显著性的抑制,转移率为0%(0/5),与对照组CMT93(100%,4/4)和CMT93/mock(80%,4/5)相比均有显著

Active immunity for anti-colorectal cancer induced by chemokine MCP-3 gene transfection

BACKGROUND & OBJECTIVE: Chemokines play an important role in the infiltration of immune cells to tumor tissues. Anti-tumor immune response had been elicited in many tumor models by the chemokine gene transfection. The aim of this study was to evaluate the possibility of inducing anti-colorectal cancer active immune response by transfection of mouse colorectal cancer CMT93 cells with chemokine MCP-3 gene. METHODS: Mouse MCP-3 gene was transduced into mouse colorectal cancer cells CMT93 by using of liposome. G418-resistant clones were selected and the MCP-3 mRNA expression was detected by RT-PCR. The chemotactic activity of MCP-3 in the cell culture supernatant was detected by chemotaxis assay. In vivo experiments were performed to observe the tumorigenicity of wild type CMT93 and MCP-3 gene modified tumor cells. The immune cell infiltration in tumor tissues and tumor metastasis were detected histopathologically. RESULTS: RT-PCR detection showed MCP-3 was expressed in MCP-3 gene-transfected G418-resistant clones(CMT93/MCP-3), but not in wild type CMT93. In chemotaxis assay, the results showed that the cell culture supernatant of CMT93/MCP-3 possess obviously chemotactic activity. The chemotactic index of the CMT93/MCP-3 supernatant was 5.57(P < 0.05). The supernatants from the control groups did not possessed the chemotactic activity. In vivo experiments showed that the tumorigenicity of CMT93/MCP-3 had not decreased significantly compared to wild type CMT93, but the tumors grew more slowly from CMT93/MCP-3 than from the controls (P < 0.05). In the tumor tissue from CMT93/MCP-3, obvious infiltrated immune cells were found, and few immune cells infiltrated in the tumor tissue from the controls. In the mice inoculated with CMT93/MCP3 tumor cells, tumor metastasis was inhibited significantly, its metastasis rate was 0(0/7), lower than that of CMT93 (100%, 4/4) and CMT93/mock (80%, 4/5) (P < 0.05). CONCLUSION: Transfection with chemokine MCP-3 gene can induce anti-colorectal cancer active immune response, but the tumor growth cannot be inhibited completely by merely MCP-3 gene transfection.