小鼠结肠炎相关结直肠癌发展过程中大肠组织IL-9的表达

Dynamic changes of IL-9 in development of colitis associated colorectal cancer in mice

目的:探讨小鼠结肠炎相关结直肠癌(CAC)发生发展过程中大肠组织白介素9(IL-9)表达的动态变化。方法:60只小鼠随机分为对照组和实验组,每组30只。实验组采用1,2-二甲肼+葡聚糖硫酸钠诱发、构建小鼠CAC模型。2组均于14、18和22周处死10只小鼠并收集大肠标本,计数肿瘤数目并鉴定其病理性质,采用免疫组化法和Western blot分别检测IL-9在大肠组织的表达部位及表达水平。结果:实验组从14周开始出现癌前病变,18~22周肿瘤增多。IL-9在对照组少量表达于上皮和间充质细胞;在实验组则显著表达于转化的上皮细胞和肿瘤基质细胞,实验组14、18、22周,小鼠大肠组织IL-9的表达逐渐升高,且高于对照组(P<0.01)。结论:IL-9在CAC发生发展过程中升高;IL-9可能是小鼠CAC发病机制中的关键因素。

Aim： To evaluate the role of interleukin 9（ IL-9） during the process of colitis associated colorectal cancer（CAC）. Methods：Sixty mice were randomly allocated into control group and experiment group with 30 mice in each group. The CAC mouse model was induced in the experiment group by the administration of 1,2-dimethylhydrazine plus dextran sulfate sodium. Ten mice in the 2 groups were sacrificed at the 14 th week,18 th week and 22 nd week respectively and colorectal specimens were collected. The density of tumors in the colorectal mucosa was quantified and recorded. The expression location and level of IL-9 in the colorectal tissue at different time points were determined by immunohistochemistry（IHC） and Western blot,respectively. Results：The results showed that tumor was appeared in the colorectal mucosa from the 14 th week,which increased from the 18 th week to the 22 nd week in the experiment group. IHC results revealed that in control group IL-9 positive cells were primarily observed in both epithelium and lamina propria compartments; in the experiment group,IL-9 positive cells were predominately located in both transformed epithelial cells and tumor stromal cells.Western blot results showed that the expression level of IL-9 in the experiment group was also increased compared with control in the 14 th week,18 th week and 22 nd week（ P〈0. 01）. A gradual increasing trend of IL-9 expression was shown from precancerous lesions to cancerous lesions. Conclusion： The expression of IL-9 is significantly increased during the process of CAC,suggesting that IL-9 may be a key factor in the pathogenesis of CAC in mice.