IL-3基因修饰的G422胶质母细胞瘤细胞体内致瘤性的改变

In vivo tumorigenicity of IL-3 gene modified G422 glioblastoma cells

目的：探讨ＩＬ－３基因治疗脑胶质瘤的可能性。方法：以重组的复制缺陷型腺病毒作为基因转染的载体，在体外将鼠ＩＬ－３基因转染Ｇ４２２小鼠胶质母细胞瘤细胞，ＲＴ－ＰＣＲ检测ＩＬ－３基因转染的Ｇ４２２细胞中是否有转基因的ｍＲＮＡ转录；ＥＬＩＳＡ法检测细胞培养上清液中分泌的ＩＬ－３的水平；ＭＴＴ法检测细胞的体外增殖能力；ＩＬ－３基因转染Ｇ４２２细胞接种小鼠皮下，观察肿瘤的生长和小鼠的存活期，并检测小鼠脾细胞诱导的ＬＡＫ，ＣＴＬ的杀伤活性。结果：ＩＬ－３基因转染的Ｇ４２２细胞中有目的基因ｍＲＮＡ的转录，分泌高水平的ＩＬ－３。ＩＬ－３基因转染的Ｇ４２２细胞的体外增殖能力没有显著的改变。皮下接种后，肿瘤生长受抑制，荷瘤小鼠的存活期延长，脾细胞诱导的ＬＡＫ，ＣＴＬ杀伤活性增强。结论：ＩＬ－３基因转染的Ｇ４２２细胞的体内致瘤性降低。

Objective: To investigate the possibility of IL-3 gene therapy of brain gliomas. Methods: IL-3 gene was introduced into G422 glioblastoma cells by recombinant adenovirus. RT-PCR was used to detect mRNA expression of the target gene in IL-3 gene modified tumor cells (G422mIL3). IL-3 secretion by G422mIL3 was assayed by ELISA. In vitro proliferation potential of G422mIL3 was detected by MTT assay. The tumor size and survival of tumor bearing mice were observed after G422mIL3 were inoculated subcutaneously. The splenic LAK and CTL cytotoxicity were analyzed by standard ^(51)Cr release assay. Results: There was mRNA transcription of target gene in G422mIL3. High level of IL-3 could be detected in the culture supernatant of G422mIL3. There was no significant change of the in vitro proliferation potential (P>0.05). When inoculated subcutaneously, the tumor growth of G422mIL3 was significantly inhibited as compared with wild type G422. The survival of mice inoculated with G422mIL3 was significantly prolongated (P<0.01), and the splenic LAK and CTL cytotoxicity were also significantly enhanced (P<0.01). Conclusion: The reduction of in vivo tumorigenicity of IL-3 gene modified G422 cells may enhanced specific and non-specific antitumor immunity.