4-1BBL基因修饰colon26细胞的体内抗肿瘤作用

The Antitumor Effect of Colon26 Transfected with 4-1BBL Gene in Vivo

背景与目的:研究4-1BBL基因修饰的小鼠结肠癌细胞瘤苗在小鼠体内诱导产生免疫反应及抗肿瘤效应的能力。材料与方法:采用脂质体介导法将真核表达质粒pMKIT/4-1BBL导入小鼠结肠癌细胞colon26,经G418筛选后获得4-1BBL稳定高表达细胞克隆colon26/4-1BBL和空载体细胞克隆colon26/pMKITneo,以丝裂霉素C处理,制成癌细胞瘤苗。将野生型colon26、colon26/pMKITneo和colon26/4-1BBL细胞分别接种于BALB/c小鼠右侧背部皮下,观察细胞致瘤性。取MMC处理的colon26细胞、colon26/pMKITneo细胞和colon26/4-1BBL细胞,分别腹腔免疫BALB/c小鼠,采用改良MTT法测定CTL和NK细胞杀伤活性,取血清用ELISA法测定IL-2、IFN-γ含量。于BALB/c小鼠皮下接种colon26细胞制备早期癌模型,第2 d腹腔注射colon26/4-1BBL瘤苗,7 d后再注射1次,观察肿瘤生长情况。结果:与野生型colon26和colon26/pMKITneo细胞相比,colon26/4-1BBL细胞在小鼠体内的致瘤性明显下降,表现为肿瘤结节出现时间延迟,肿瘤体积明显小于对照组(P<0.05)。MMC处理的肿瘤细胞瘤苗免疫小鼠后,colon26/4-1BBL组小鼠CTL和NK细胞的杀伤活性明显增高(P<0.05);血清IL-2和IFN-γ的含量明显增高(P<0.01);而且能对亲本肿瘤细胞colon26产生免疫保护作用,大部分小鼠能保持无瘤状态长期存活(100 d以上)。colon26/4-1BBL瘤苗治疗后,部分小鼠保持无瘤生存,成瘤小鼠肿瘤生长缓慢,小鼠生存期明显延长(>70d)。结论:4-1BBL基因修饰的小鼠结肠癌细胞瘤苗能显著增强小鼠的免疫功能,并能产生显著的抗肿瘤作用。

BACKGROUND AND AIM： To study the antitumor effect of colon26 cells transfected with 4-1BBL gene in vivo. MATERIALS AND METHODS： The eukaryotic expression vector pMKIT/4-1BBL was transfected into colon26 cells with lipofectamine, The transfected cells were selected by G418 and termed colon26/4-1BBL. Then the tumor cell vaccine （TCV） was obtained by treatment with MMC. Three mice models （colon26, colon26/pMKITneo , and colon26/4-1BBL ） were established to study the antitumor effects of TCV-4-1BBL. The cytolytic activity of CTL and NK were detected by variable MTT method. The content of IL-2 and IFN-T in serum were measured by ELISA . The early cancer model was made by inoculating colon26, then the mice were treated with TCV-4-1BBL on the second and seven days. RESULTS： Compared with colon26 and colon26/pMKITneo, colon26/4-1BBL cells grew much slower in mice. Mostly syngeneic mice were protected by inoculation with TCV-4-1BBL, survived free from tumor for a long period （over 100 days） The cytolytic effect of CTL and NK in colon26/4-1BBL mice were improved significantly, and the contents of IL-2 and IFN-y were also increased. Cured by TCV-4-1BBL,some mice could survive free from tumor,and other bearing-tumor mice whose tumor grew slowly.The survival periods of all these mice were significantly prolonged. CONCLUSION： The antitumor effect against syngeneic marine colon carcinoma and the immune response in vivo were obviously enhanced by treating them with TCV-4-1BBL.