【摘要】 目的:评估无毒诺维氏梭菌对小鼠移植性肝癌的抑瘤效应,及其在肿瘤和重要器官的定植情况,并确定瘤内注射的最佳剂量。方法:建立H22皮下移植瘤BALB/c小鼠模型后称小鼠重量,测量肿瘤大小,并按随机原则分为生理盐水组、无毒诺维氏梭菌低剂量组(1.0×10~7/mL,0.5 mL)、中剂量组(1.0×10~8/mL,0.5 mL)和高剂量组(1.0×10~9/mL,0.5 mL)。每天观察小鼠的一般情况,每周3次定时测量小鼠重量,每周2次测肿瘤大小,评估细菌的抑瘤效应。采用革兰染色法、细菌培养法、PCR技术,了解肿瘤和重要器官中诺维氏梭菌的定植情况。利用HE染色、脾脏指数、胸腺指数,了解细菌干预后荷瘤鼠炎症反应、免疫功能及肿瘤转移的情况。结果:无毒诺维氏梭菌低、中、高剂量组抑瘤率分别为8.49%、44.59%、14.84%,高剂量组小鼠一般情况最差,中剂量组小鼠一般情况最好。培养结果显示,肿瘤组织中有诺维氏梭菌定植,主要脏器无该菌定植。高剂量组和中剂量组荷瘤鼠脾脏质量明显增大,两组脾脏质量和指数与生理盐水组比较差异有统计学意义(P<0.05)。高剂量组胸腺显著缩小,但胸腺指数各组间差异无统计学意义(P>0.05)。结论:无毒诺维氏梭菌能选择性地定植于肝癌区,中剂量(1.0×10~8/mL,0.5 mL)无毒诺维氏梭菌能有效抑制免疫正常小鼠H22皮下移植瘤,可能与抗肿瘤免疫和炎症反应有关。更多还原

【Abstract】 Objective: To evaluate the efficacy of nontoxigenic Clostridium novyi(C.novyi-NT) in the treatment of the mice bearing subcutaneously implanted H22 hepatocarcinoma, and its colonization in tumors and vital organs, so as to determine the optimum dose. Methods: 32 specific pathogen free BALB/c mice were subcutaneously transplanted with H22 hepatocarcinoma. Tumor-bearing mice were assigned to the normal saline group, the low-dose group(1.0×10~7/mL, 0.5 mL), the medium-dose group(1.0×10~8/mL, 0.5 mL) and the high-dose group(1.0×10~9/mL, 0.5 mL) according to the dosage of C.novyi-NT. During the experiment, general conditions of mice were observed every day; mice were weighed three times a week; tumor diameter was measured twice a week. The colonization of Clostridium novyi(C.novyi) in tumors and important organs was studied by Gram stain, bacterial cultivation and PCR. HE stain, spleen index and thymus index were used to investigate the inflammatory response, immune function and tumor metastasis in tumor-bearing mice after bacterial intervention. Results: Tumor inhibitory rates of the low-dose group, the medium-dose group, the high-dose group were 8.49%, 44.59% and 14.84%, respectively. Mice in the high-dose group demonstrated the worst general condition, while mice in the medium-dose group showed the best general condition. C. novyi populated tumor tissues, but they didn’t move to other organs. The spleen mass of tumor-bearing mice in the high-dose group and the medium-dose group increased significantly; and differences between the normal saline group and the above two groups were statistically significant in spleen mass and index(P<0.05). The thymus gland in the high-dose group decreased significantly, but there was no significant difference in the thymus index among groups(P>0.05). Conclusion: C.novyi-NT selectively populate hepatocarcinoma tissues. Medium-dose(1.0×10~8/mL, 0.5 mL) could effectively inhibit the growth of H22 hepatocarcinoma in mice with normal immunity. The antitumor effects of C. novyi-NT may be related to antitumor immunity and tumor inflammatory response.更多还原