转录因子E2F-1对裸鼠人胃癌细胞移植瘤生长的影响

The effects of E2F transcription factor 1 on human gastric subcutaneous tumor of nude mice

目的 观察含有转录因子E2F-1的重组逆转录病毒载体（pLXSN-E2F-1）对裸鼠人胃癌细胞移植瘤E2F-1基因的表达和肿瘤生长的影响.方法 建立人胃癌MCC-803细胞裸鼠移植肿瘤模型,随机分为pLXSN-E2F-1组、pLXSN组、生理盐水组.隔天向各组分别注射相应药物0.2 ml,共7次,同时测量各组肿瘤体积.15 d后处死裸鼠,显微镜下观察移植瘤组织形态变化,用免疫组织化学法、半定量逆转录-聚合酶链反应（RT-PCR）和Western blot技术检测移植瘤中E2F-1基因的表达,脱氧核苷酸末端转移酶介导的缺口末端标记法（TUNEL）检测肿瘤细胞凋亡指数.结果 与生理盐水组和pLXSN组比较.pLXSN-E2F-1组肿瘤生长速度明显减慢（P〈0.05）;病理学观察确认所取组织为恶性肿瘤组织;免疫组织化学结果 显示pLXSN-E2F-1组的肿瘤细胞细胞质内有较多棕褐色颗粒沉着,pLXSN组和生理盐水组肿瘤细胞细胞质内均未见或偶见棕褐色颗粒沉着;半定量RT-PCR和Western blot结果 均显示pLXSN-E2F-1组E2F-1表达较pLXSN组和生理盐水组明显上调（P〈0.05）;pLXSN-E2F-1组的凋亡指数（15.4±4.1）%,显著高于pLXSN组（8.3±2.2）%和生理盐水组（8.1±2.3）%（P〈0.05）.结论 逆转录病毒载体pLXSN-E2F-1瘤内注射可抑制人胃癌裸鼠移植瘤的生长.

Objective To study the effects of pre-buih recombinant retroviral vector expressing the E2F transcription factor 1 （E2F-1） gene （pLXN-E2F-1） on the expression of E2F-1 gene and the growtb of human gastric subcutaneous tumor of nude mice. Methods BALB/C nude mice were inoculated subcu-taneously with MGC-803 cells to establish the nude mouse gastric cell carcinoma model, and the models were randomly divided into pLXSN-E2F-1 group, pLXSN group and NS group. The corresponding agents were injected （0.2 ml per time） for consecutive 7 times on every two days,and the tumor volume was measured at the same time. Nude mice were killed after 15 days,and analyzed by statistics. After HE stai-ning, histopathologieal characteristics of subcutaneous tumor were observed under a microscope, Immunohis-tochemistry was used to detect the expression of E2F-1 in the subcutaneous tumor. The expression of E2F-1 mRNA and protein was detected by semi-quantitative reverse transcription polymerase chain reaction （RT-PCR） and Western blotting methods respectively. The apoptosis of tumor xerographs was measured by the terminal deoxynucleotidyl transferase dUTP nick end lakeling （TUNEL）. Results The mean rate of tumor growth in the E2F-1 treatment group was much slower than that in the pLXSN group and NS group （P〈0.05）. The tissue obtained from the nude mice was diagnosed that was tumor under a microscope after HE staining. Immunohistochemistry revealed that there were many brown granules in pLXSN-E2F-1 group, while almost not found in the other two groups. Compared with pLXSN group and NS group, the expression level of E2F-1 mRNA and protein were increased （P〈0.05） in the pLXSN-E2F-1 group. The apoptotic rate in the pLXSN-E2F-1 treatment group was （15.4±4.1） %, significantly higher than that in the other two groups [（8.3±2.2）% for pLXSN and （8.1±2.3）% for NS （P〈0.05）].Conclusion Intra-tumor in-jection of retrovirus pLXSN-E2F-1 can significantly inhibit the growth of human gastric subcutaneous tumor of nude mice.