香菇多糖抑制乳腺癌4T1细胞小鼠移植瘤增殖机制研究

Inhibition mechanism of lentinan on the proliferation of breast cancer 4T1 cells xenograft model in mice

目的观察香菇多糖对乳腺癌小鼠的脾脏、肿瘤组织及外周血中白细胞介素-35(IL-35)表达影响,探讨香菇多糖抑制乳腺细胞癌的可能作用机制。方法 30只雌性Balb/c小鼠分为对照组、模型组和香菇多糖给药组(200mg/kg),每组10只。注射4T1细胞建立4T1乳腺癌小鼠模型,给药组持续灌服给药香菇多糖,每只小鼠给药剂量200mg/kg,1次/d,对照组和模型组同时给予等量的生理盐水,共24d。每隔2d测量体质量和瘤体体积,治疗结束后剖取肿瘤组织和肺脏分别用于记录肿瘤质量和肺表面转移结节数;采用酶联免疫吸附法检测血清中γ-干扰素(IFN-γ)、IL-4和IL-35水平;采用定量PCR检测肿瘤组织和脾组织中IL-35mRNA相对表达水平;蛋白质印迹法检测脾组织中IL-35蛋白表达。采用SPSS 23.0对数据进行统计学分析,2组比较采用t检验,荷瘤小鼠肿瘤生长曲线采用双因素方差分析,多组比较采用单因素方差分析,多重比较采用LSD法;不符合正态分布,采用非参数检验。结果给药组肿瘤生长速度减缓并在第24天后肿瘤大小低于模型组肿瘤大小,差异有统计学意义,F=6.313,P<0.05;给药组肿瘤质量(0.37±0.09)g,低于模型组肿瘤质量(0.51±0.11)g,差异有统计学意义,U=18.00,P<0.01。给药组IFN-γ水平为(194.42±13.62)pg/mL,高于模型组(167.85±14.31)pg/mL,差异有统计学意义,F=18.517,P<0.01;给药组IL-35水平为(15.27±2.01)pg/mL,低于模型组(17.62±2.40)pg/mL,差异有统计学意义,F=28.180,P<0.01。给药组肿瘤组织中p35mRNA表达水平为0.37±0.18,低于模型组1.02±0.31,差异有统计学意义,t=5.607,P<0.01;给药组肿瘤组织中EBI3mRNA表达水平为0.51±0.14,低于模型组1.02±0.44,差异有统计学意义,t=3.433,P<0.05。脾组织中p35mRNA表达水平给药组为0.65±0.13,低于模型组0.86±0.14,差异有统计学意义,F=12.052,P<0.01,EBI3mRNA表达水平给药组为2.11±0.58,低于模型组3.43±1.47,差异有统计学意义,F=17.618,P<0.01。脾组织中p35蛋白表达水平给药组为0.45±0.20,模型组为0.87±0.27,差异有统计学意义,F=11.901,P<0.01;EBI3蛋白表达水平给药组为0.75±0.20,模型组为0.96±0.23,差异有统计学意义,F=9.207,P<0.01。结论香菇多糖通过降低乳腺癌4T1细胞移植瘤小鼠外周血、肿瘤及脾组织内IL-35表达,显著抑制移植瘤的增殖,其机制可能与调节机体免疫功能密切相关。

Objective To observe the effect of lentinan on the expression of Interleukin-35(IL-35)in the spleen,tumor tissue and peripheral blood of mice with breast cancer,and explored the possible mechanism of lentinan in inhibiting breast cancer.Methods Thirsty female Balb/c mice were divided into the control group,tumor-bearing mice were randomly divided into model group and lentinan administration group(200 mg/kg),10 mice in each group.4 T1 cells were injected subcutaneously into the right ventral surface to establish a 4 T1 breast cancer mouse model.The mice in the administration group were given continuous oral administration of lentinan,each mouse was given a dose of 200 mg/kg,once a day,the control group and the model group were given the same amount of normal saline at the same time for 24 days.Measure the body mass and tumor volume every two days.After the treatment,the tumor tissue and lung are taken to record the tumor mass and the number of metastatic nodules on the lung surface.Enzyme-linked immunosorbent assay was used to detect the serum levels of interferon-γ(IFN-γ),IL-4 and IL-35;Quantitative polymerase chain reaction(qPCR)was used to detect the relative expression level of IL-35 mRNA in tumor tissues and spleen tissue;Western blotting was used to detect the expression of IL-35 protein in spleen tissue.SPSS 23.0 statistical software was used to analyze the data.T test was used for comparison between the two groups,two-way ANOVA was used for tumor growth curve of tumor bearing mice,one-way ANOVA was used for multi group comparison,and LSD method was used for multiple comparison.Non parametric test was used for non-linear distribution.Results The tumor growth rate of the tumor-bearing mice administration group slowed down and the tumor size was lower than the tumor size of the model group after the 24 th day,the difference was statistically significant,F=6.313,P<0.05.In addition,the tumor mass of the administration group was(0.37±0.09)g,which was lower than the tumor mass of the model group(0.51±0.11)g,the difference was statistically significant,U=18.00,P<0.01.The level of IFN-γin the administration group was(194.42±13.62)pg/ml,which was higher than the model group(167.85±14.31)pg/ml,the difference was statistically significant(F=18.517,P<0.01),and the level of IL-35 in the administration group was(15.27±2.01)pg/ml,which was lower than the model group(17.62±2.40)pg/ml,the difference was statistically significant,F=28.180,P<0.01.The expression level of p35 mRNA in tumor tissues of the administration group was 0.37±0.18,which was lower than 1.02±0.31 of the model group,and the difference was statistically significant,t=5.607,P<0.01;the expression level of EBI3 mRNA in tumor tissues of the administration group was 0.51±0.14,lower than 1.02±0.44 in the model group,the difference was statistically significant,t=3.433,P<0.05.The p35 mRNA expression level in the spleen tissue of the administration group was 0.65±0.13,which was lower than the model group 0.86±0.14,the difference was statistically significant(F=12.052,P<0.01),the EBI3 mRNA expression level was 2.11±0.58 in the administration group,which was low in the model group 3.43±1.47,the difference was statistically significant,F=17.618,P<0.01.Similarly,the expression levels of p35 and EBI3 protein in spleen tissues of the administration group were lower than those of the model group,respectively(0.45±0.20 vs 0.87±0.27,F=11.901,P<0.01,0.75±0.20 vs 0.96±0.23,F=9.207,P<0.01),the differences were statistically significant.Conclusions Lentinan can significantly inhibit the proliferation of breast cancer 4 T1 cell transplanted tumor by reducing the expression of IL-35 in peripheral blood,tumor and spleen tissues in mice.Its mechanism may be closely related to the regulation of immune function.