转基因LIGHT的人脐血间质干细胞对胃癌抑制杀伤作用的研究

Study of inhibiting and killing effects of transgenic LIGHT human umbilical cord blood mesenchymal stem cells on stomach cancer

目的探讨转基因LIGHT脐血间质干细胞对胃癌的抑制杀伤作用。方法采用慢病毒载体穿梭质粒pGC-FU-LIGHT．在脂质体Lipofectamine2000介导下与结构质粒pHelper1．0和包膜质粒pHelper2．0共转染293T细胞获得慢病毒后分别感染人脐血间质干细胞．获得重组慢病毒感染的脐血间质干细胞（MSC-LIGHT）和空载体慢病毒感染的脐血间质干细胞（MSC）。人胃癌细胞SGC-7901注射到裸鼠腹股沟皮下建立胃癌移植瘤裸鼠模型。荷瘤裸鼠分为MSC-LIGHT组、MSC组和生理盐水组，每组5只，向3组裸鼠瘤周分别注射MSC-LIGHT、MSC及生理盐水。隔日1次，注射3次，第4周取材，观察注射前后瘤体生长情况。反转录PCR和ELISA法测定3组胃癌组织中LIGHT的mRNA和蛋白表达；病理切片观察瘤体的坏死面积。结果MSC．LIGHT组、MSC组和生理盐水组裸鼠肿瘤体积分别为（0．45±0．25）cm3、（0．64±0．36）cm3和（1．21±0．79）cm3，3组比较差异有统计学意义（P〈0．05）。3组LIGHTmRNA相对表达量分别为2．96±0．27，1．23±0．47和0．73±0．10．蛋白浓度分别为（167．89±2．31）、（73．22±5．74）和（49．66±5．25）ng／L；3组比较差异均有统计学意义（均P〈0．01）。病理切片显示MSC-LIGHT组坏死面积最大。结论转基因脐血间质干细胞旁分泌LIGHT对胃癌细胞具有明显的抑制杀伤作用。

Objective To study the inhibition and killing effect of transgenic LIGHT umbilical cord blood mesenchymal stem cells （UCBMSCs） on stomach carcinoma. Methods The LIGHT gene was recombined to construct the transfer plasmid pGC-FU-LIGHT by infusion technique. The 293T ceils were co-transfected with the transfer plasmid pGC-FU-LIGHT, the construction plasmid Helper 1.0 and the envelope plasmid Helper 2.0 with the help of lipofectamine 2000 to produce lentiviral particles. Transgenic UCBMSCs（MSC-LIGHT） and empty carrier UCBMSCs （MSC） were obtained. Human gastric cancer cell SGC-7901 was injected into nude mice subcutaneously groin. The model of transplanted human gastric cancer cell SGC-7901 in nude mice was established. Tumorigenesis nude mice were separated into three groups randomly with 5 in each group： MSC-LIGHT group, MSC group, and NS group. Three groups of nude mice were injected around the tumor with MSC-LIGHT, MSC and NS every other day for 3 times. Four weeks later, the transplanted gastric cancer volume was measured. The expressions of LIGHT in the three groups were determined by RT-PCR and ELISA method. The necrosis area in the tumors was calculated under pathological examination. Results The average volume of transplanted tumor was （0.45±0.25） cm3 in MSG-LIGHT group, （0.64±0.36） cm3 in MSG group, and （1.21±0.79） cm3 in NS group, and the difference was statistically significant （P〈0.05）. The LIGHT mRNA was 2.96±0.27, 1.23±0.47, and 0.73 ±0.10 respectively. The LIGHT protein was （167.89±2.31）, （73.22±5.74）, and （49.66±5.25） ng/L. The differences were all statistically significant among the three groups （both P〈0.01 ）. Pathological examination showed that the necrosis area was largest in MSC-LIGHT group. Conclusion Transgenic UCBMSCs secret LIGHT in a paracrine manner, which has inhibition and killing effects on stomach carcinoma.