微小RNA-155在结肠炎相关结肠癌发生过程中的表达变化  

Changes of miR-155 expression in colitis-associated colonic carcinogenesis

作　　者：李伟伟[1] 韩文晓[1] 赵新华[1] 汪红英[1] 

机构地区：[1]北京协和医学院中国医学科学院肿瘤医院肿瘤研究所分子肿瘤学国家重点实验室,100021

出　　处：《中华肿瘤杂志》2014年第4期257-262,共6页Chinese Journal of Oncology

基　　金：国家自然科学基金（91129717）

摘　　要：目的探究微小RNA-155（miR-155）在结肠炎相关结肠癌发生过程中的作用并初步筛选其下游的靶基因。方法联合应用氧化偶氮甲烷（AOM）和葡聚糖硫酸钠（DSS）诱导C57BL／6小鼠发生结肠炎相关结肠癌，得到从结肠炎到结肠癌的3个不同阶段的小鼠模型（分别命名为AD1、AD2和AD3），同时设立无任何处理的对照组和只给予DSS来模拟慢性炎症的DSS组，取各组小鼠的结肠组织提取总RNA，逆转录成cDNA后应用实时荧光定量PCR检测miR-155的表达。结合前期的全基因组表达谱芯片数据和miRNA靶基因预测软件TargetScan和PicTar预测出来的潜在靶基因，初步筛选miR-155的下游靶基因，并用PCR进一步验证潜在靶基因的表达变化。结果ADM和DSS联合使用能有效地模拟人类结肠炎相关结肠癌，结肠炎相关结肠癌的演变顺序为正常、轻度不典型增生、中度不典型增生、重度不典型增生和腺癌。DSS组小鼠结肠miR-155的表达水平（O．0056±0．0037）与对照组（0．0120±0．0051）比较，差异无统计学意义（P〉0．05），而AD3组小鼠的miR-155表达水平（0．0544±0．0270）高于DSS组（0．0056±0．0037），差异有统计学意义（P〈0．01）。结合全基因组表达谱芯片和miRNA靶基因预测软件，初步筛选出miR-155可能的下游靶基因为Tle4、Kena1、Itk、Beorl1、Caena1c、Rspo2和Foxo3，其中Kcna1和Cacna1c经PCR验证与芯片检测结果一致。结论miR-155的表达升高与结肠炎相关结肠癌有关，而与慢性炎症无关。Objective To investigate the changes of miR-155 and its target genes in colitis- associated carcinogenesis. Methods Colitis-associated colon cancer was induced by azoxymethane （AOM） and dextran sulfate sodium （DSS） in C57BL/6 mice. Mice of three different stages during the development of colon cancer were obtained, named AD1, AD2 and AD3, respectively. A control group of mice without any treatment and a DSS only group representing chronic inflammation without cancer were set up as well. Colon tissue was collected and expression of miR-155 in the colon tissues was measured by real-time fluorescent quantitative PCR. TargetScan and PicTar were used to predict potential target genes of miR-155, which were then preliminarily screened with our gene expression microarray database of AOM-DSS mouse model. Regular PCR was used to confirm the changes of the expression of these potential target genes in AOM-DSS mouse model. Results Colitis-associated colon cancer was effectively induced by azoxymethane and dextran sulfate sodium in C57BL/6 mice. Histological examination revealed that the evolution process was sequentially from normal, mild dysplasia, moderate dysplasia, and severe dysplasia to adenocarcinoma in the AOM-DSS mouse model. The level of miR-155 was gradually elevated with the formation of colitis- associated colon cancer. There was no significant difference between the levels of miR-155 expression in the DSS group （0. 005 6 ± 0.003 7） and control group （0.012 0 ± 0.005 1 ） （P 〉 0.05 ）, but the level of miR- 155 in the AD3 group （0. 054 4 ±0.027 0） was significantly higher than that of the DSS group （0.005 6 ± 0.003 7）（P 〈0.01 ）. No significant change of miR-155 expression was found in the DSS only group. The relative expression levels of miR-155 in the control group, DSS only group and AD3 group were 0.012 0 ± 0.005 1, 0.005 6 ± 0. 003 7, 0. 054 4 ± 0. 027 0, respectively. Data analysis with the gene expression microarray showed that Tle4, Kcna1, Itk, Bcorl1, Cacna1c, Rs

关 键 词：微RNAS 结肠炎 结肠肿瘤 氧化偶氮甲烷 葡聚糖硫酸钠 小鼠 

分 类 号：R735.35[医药卫生—肿瘤]