BLC肿瘤细胞疫苗与顺铂联合抗肿瘤作用的实验研究

背景与目的:趋化因子是一类小分子蛋白质,是引发细胞迁移的主要介质,研究表明,趋化因子可提供较强的稳定抗肿瘤免疫。本研究拟用BLC基因修饰的肿瘤细胞疫苗与顺铂联合作用肿瘤细胞,以探讨其抗肿瘤效应与机理。方法:首先将重组质粒pcDNA-BLC转染到Colon26小鼠结肠癌细胞株或LL/2小鼠肺癌细胞株,建立稳定表达BLC的转化肿瘤细胞株(简称Tc细胞)。作为对照,质粒pcDNA(+)也稳定转染到Colon26或LL/2肿瘤细胞。用Tc肿瘤细胞建立小鼠动物模型,同时以稳定转染质粒pcDNA3.1(+)的肿瘤细胞(简称为Pc细胞)和未转染质粒的肿瘤细胞(简称为Nc细胞)为对照建立小鼠模型。将5×105个Tc细胞、Pc细胞和Nc细胞分别接种于BALB/c小鼠(Colon26细胞小鼠模型)或C57BL/6小鼠(LL/2细胞小鼠模型)右侧胁部皮下,每组20只,每组再随机分为2小组(即Tc-A、Tc-B,Pc-A、Pc-B和Nc-A、Nc-B组),每小组10只。治疗方案:以A组(包括Tc-A、Pc-A和Nc-A)为化疗组,分别加顺铂2mg/kg,腹腔内注射,每周1次,连续2次;而B组(包括Tc-B、Pc-B和Nc-B)为生理盐水对照组,每只小鼠腹腔相应地注射0.1ml生理盐水。观察小鼠肿瘤生长情况、存活期及不良反应,并进行肿瘤组织形态学观察和肿瘤细胞凋亡分析。结果:联合治疗组Tc-A显示明确抗肿瘤作用,小鼠肿瘤生长受到明显抑制,

Experimental studies on anti-tumor effects of BLC-modified tumor cell vaccine combined with cisplatin

BACKGROUND & OBJECTIVE: Chemokines are small molecule proteins that are the main mediators of cell migration. Studies indicated that chemokines could induce antitumor immune response strongly and steadily. At present, there was not antitumor therapy about chemokine BLC combined with chemotherapy. This study was designed to explore the anti-tumor effects and mechanisms of BLC-modified tumor cell vaccine combined with cisplatin. METHODS: Firstly, we transfected pcDNA-BLC into murine tumor cell lines and established stable transfected tumor cell lines (Colon26 and LL/2) to express BLC. Null plasmid pcDNA3.1 (+) was also transfected into Colon 26 or LL/2 cells stably for comparison. We established mouse model with pcDNA-BLC stable transfected tumor cells (Tc), control mouse model with pcDNA3.1(+) stable transfected tumor cells (Pc), and mouse model with parental tumor cells (Nc). Then the 60 mice were inoculated subcutaneously (s.c.) in the right flanks with a total of 5x10(5) viable tumor cells (Tc to 20 mice, Pc to 20 mice, and Nc to 20 mice, respectively; 6-8 week BALB/c female mouse in colon 26 mouse model or 6-8 week C57BL/6 female mouse in LL/2 mouse model). The groups (Tc, Pc, and Nc) were randomly subdivided into Group A and Group B with 10 mice for each, resulting in Tc-A/Tc-B, Pc-A/Pc-B, and Nc-A/Nc-B, respectively. Group A (including Tc-A, Pc-A, and Nc-A) as chemotherapy group was injected (i.p.) with 0.1 ml cisplatin at the concentration of 2 mg/kg once a week for two weeks; Group B (including Tc-B, Pc-B, and Nc-B) as control with 0.1 normal saline. We further observed anti-tumor activity including the tumor growth, mice survival rate, side effects as well as tumor morphological analysis. Apoptotic cells were also determined in tumor tissues. RESULTS: The combination therapy group Tc-A showed significant anticancer activities. The tumor growth was inhibited efficiently with 3/10 mice showing complete regression in LL/2 mouse model and 1/10 mice showing complete regression in Colon 26 mouse model. The combination therapy group Tc-A showed that the survival rate of mice was 100% in the two mouse models, compared with 68% in group Tc-B in C57BL/6 mouse model and 65% in group Tc-B in Colon 26 mouse model and those in other groups. In addition, the combination therapy group Tc-A induced tumor cell apoptosis significantly. CONCLUSIONS: The therapy of BLC-modified tumor cell vaccine combined with cisplatin had significant synergistic effect against tumor. It might develop a new approach for specific immunotherapy of tumors.