表皮葡萄球菌DNA体内抗小鼠宫颈癌U14的实验研究

Antitumor Action of Staphylococcus Epidermidis DNA in U14 Cervical Cancer Bearing Mice

目的探讨表皮葡萄球菌DNA(S.epidermidis DNA)体内抗宫颈癌U14的作用。方法提取S.epidermi-dis DNA。于昆明小鼠前臂皮下注射宫颈癌U14细胞(1×107 mL-1)0.1mL.只-1,共24只。造模7d后,将荷瘤小鼠按随机数字表法分为S.epidermidis DNA治疗组(DNA组,n=8)、溶剂对照组(LES组,n=8)、模型对照组(NS组,n=8),并于荷瘤小鼠前臂分别肌内注射S.epidermidis DNA(质量浓度100μg.mL-1)、DNA溶解液、生理盐水,0.3mL.次-1,每2天1次,共注射8次。采用MTT法测OD值计算刺激指数,记录荷瘤小鼠的存活时间,测量肿瘤体积,计算S.epidermidis DNA平均抑瘤率。结果荷瘤小鼠造模成功率为100%。DNA组的荷瘤小鼠脾脏T淋巴细胞的刺激指数(0.603±0.086)较LES组(0.433±0.062)、NS组(0.428±0.056)明显增高(P<0.05);肿瘤大小DNA组[(3.240±0.053)cm2]较LES组[(5.460±0.045)cm2]、NS组[(5.620±0.064)cm2]明显缩小(P<0.05);DNA组的生存时间[(38.250±5.245)d]较LES组[(17.150±3.563)d]、NS组[(16.650±2.187)d]延长(P<0.05);S.epidermidis DNA平均抑瘤率为62.9%。结论 S.epidermidis DNA体内治疗后,荷瘤小鼠脾脏T淋巴细胞增殖功能明显增强,肿瘤大小明显缩小,小鼠平均生存时间明显延长,抑瘤率较高。S.epider-midis DNA具有一定的抗小鼠宫颈癌U14的作用。

Objective To investigate the antitumor action of Staphylococcus epidermidis DNA（S.epidermidis DNA） in U14cervical cancer bearing mice.Methods Twenty-four Kunming mice were injected with 0.1mL U14cervical cancer cell suspension（1×10 7 mL） under the skin of the forearm to prepare U14cervical cancer bearing mice.At 7days after injection,tumor-bearing mice were intramuscularly injected 8times with 100 μ g.mL-1 S.epidermidis DNA（DNA group,n= 8）,buffer solution（LES group,n=8） or normal saline（NS group,n=8） in the forearm 0.3mL every other day.The proliferation of splenic T lymphocytes was determined by MTT method.The survival time of tumor-bearing mice was recorded and the volume of tumors was measured.In addition,the average tumor inhibition rate was calculated.Results Tumor-bearing mouse model was successfully established in all mice.Compared with LES group and NS group,S.epidermidis DNA treatment significantly increased stimulation index of splenic T lymphocytes（0.603±0.086vs 0.433±0.062and 0.603±0.086vs 0.428±0.056,respectively;P＆lt;0.05）,obviously decreased tumor size [（3.240±0.053） cm 2 vs（5.460±0.045） cm 2 and 3.240±0.053vs 5.620±0.064） cm 2,respectively;P＆lt;0.05）],and markedly prolonged survival time [（38.250±5.245） d vs（17.150± 3.563） d and（38.250±5.245） d vs（16.650±2.187） d,respectively;P＆lt;0.05）].The average tumor inhibition rate was 62.9%in DNA group.Conclusion S.epidermidis DNA treatment can promote the proliferation of splenic T lymphocytes,reduce tumor size,inhibit tumor growth and prolong survival time in tumor-bearing mice,suggesting that S.epidermidis DNA has antitumor action in U14cervical cancer bearing mice.