转染4-1BBL基因的胃癌细胞在小鼠体内的抗肿瘤及免疫调节作用

Antitumor effect and immune regulation effect of MFC transfected with 4-1BBL gene in vivo

目的:观察转染4-1BBL基因的小鼠胃癌细胞株MFC的体内致瘤性及其对小鼠免疫功能的影响。方法:通过脂质体介导以重组质粒pMKITneo和pMKITneo/4-1BBL转染小鼠胃癌细胞株MFC。用RT-PCR法检测目的基因的表达。计数法绘制体外培养细胞生长曲线。将转染前后肿瘤细胞,分别接种于615小鼠背部皮下观察其致瘤性。流式细胞仪测定荷瘤小鼠外周血NK、CD4+T和CD8+T细胞数,并测定荷瘤小鼠肿瘤结节内细胞凋亡率。结果:MFC/4-1BBL细胞中可检测到4-1BBLmRNA表达。转染前后肿瘤细胞的体外生长速度无明显变化。MFC/4-1BBL细胞在小鼠体内的致瘤性较MFC/pMKITneo细胞和野生型MFC细胞明显降低。接种MFC/4-1BBL细胞的小鼠外周血NK细胞及CD8+T细胞数明显增多;其肿瘤结节内细胞凋亡率亦明显增高。结论:转染4-1BBL基因后并未影响MFC细胞的体外生长,但其在小鼠体内的致瘤性明显降低。MFC/4-1BBL细胞可诱导荷瘤小鼠体内CD8+T和NK细胞增殖,而且能促进肿瘤细胞的凋亡。

OBJECTIVE： To observe the oncogenicity in vivo of mouse gastric carcinoma cell lines MFC transfected with 4-1BBL gene and its effect on mouse immune function. METHODS： Mouse forestomach carcinoma cell lines （MFCs） were transfected with pMKITneo/4-1BBL and pMKITneo through LipofectamineTM2000 mediation. The expression of 4-1BBL gene was detected by RT-FCR. The growth curve was drew by counting the number of the tumor cells. The oncogenicity of MFC/4-1BBL cells, MFC/pMKITneo cells and wild-type MFC cells was observed by injecting the cells subcutaneouly into 615 mice. The numbers of NK cells, CD4^＋ T cells and CD8^＋ T cells in peripheral blood of tumor-bearing mice were measured by FCM, and so was the apoptosis ratio of tumor cells. RESULTS： The expression of 4-1BBL mRNA was detected in MFC/4-1BBL cells. There was no difference between the transfected and untransfected cells growing in vitro. The oncogenicity of MFC/4-1BBL cells was obviously lower than that of MFC/pMKITneo cells and wild-type MFC cells in vivo. The numbers of NK cells and CD8^＋ T cells in peripheral blood of MFC/4-1BBL mice were notably more than those in MFC/pMKITneo mice and MFC mice; the apoptosis ratio of tumor cells in MFC/4-1BBL mice was dramatically higher than that in the other two groups. CONCLUSIONS： There is no change of MFC cells growing in vitro, after transfected with 4-1BBL. However, the oncogenicity of MFC/4-1BBL cells markedly declines, and these cells can induce the proliferation of NK cells and CD8^＋ T cells in tumor-bearing mice. Moreover, the apoptosis ratio of tumor cells is increased obviously in MFC/4-1BBL mice.