氯吡格雷在化学诱导小鼠结肠炎相关肿瘤发生中的作用

摘要

OBJECTIVE To investigate the effect of clopidogrel(Clog),a platelet aggregation inhibitor,on the development of colitis-associated colon cancer(CAC)and its possible mechanism. METHODS To establish a CAC model,male BALB/c mice were treated with single azoxymethane(AOM) 10 mg · kg-1 by ip. One week later,the mice drank 2.5% dextran sulfate sodium(DSS)for one week and water for two weeks,which lasted three cycles. From the first day mice received 2.5%DSS water, Clog 12.5,25.0 and 50.0 mg · kg-1 was ig administered once a day. Body mass,clinical symptoms,the number of colon tumor and tumor size in colon tissue were recorded. Hyperplasia of tumors was analyzed by HE staining. In the early inflammatory phase of the CAC model,the length of colons was measured, histological structure and epithelium cell proliferation of colon tissues were evaluated by HE staining and Ki67 staining,respectively. In the tumorigenesis and progression phase of the CAC model,epithe⁃lium cell proliferation of colon tissues was evaluated by Ki67 staining. The mRNA expression of tumor necrosis factor-α(TNF-α)was detected by real-time quantitative PCR. The expression of chemokine(C-X-C motif)ligand 2(CXCL2)and its receptor 2(CXCR2)in colon tissues was detected by PCR and immu⁃nohistochemistry. RESULTS Compared with model group,clinical symptoms of mice in Clog 12.5 mg · kg-1 group were alleviated,the size of colon tumors was decreased(P<0.05),and hyperplasia of tumors was reduced(P<0.05). During the inflammatory phase,the clinical symptoms of mice in Clog 12.5 mg·kg-1 group were significantly alleviated(P<0.05),the decrease of body mass was reduced(P<0.01),the colon shrinkage was ameliorated(P<0.01),the inflammatory injury and epithelium cell proliferation in colon tissues were reduced(P<0.05). During the tumorigenesis and progression phase,epithelium cell prolif⁃eration in colon tissues in Clog 12.5 mg·kg-1 group was reduced(P<0.01),and the mRNA and protein expression of TNF-α,CXCL2 and CXCR2 of colon tissues was decreased(P<0.05). CONCLUSION Clog can alleviate inflammation during the CAC early inflammatory phase and inhibit the formation of CAC. The antitumor effect of Clog may be related to the decrease in expression of CXCL2 and CXCR2.%目的：探究血小板聚集抑制剂氯吡格雷（Clog）对结肠炎相关结肠癌（CAC）形成过程的影响及其作用机制。方法雄性BALB/c小鼠分为5组，正常对照组，模型组，Clog 12.5，25.0和50.0 mg · kg-1组。CAC模型组首先1次ip给予氧化偶氮甲烷（AOM）10 mg·kg-1，1周后，每天饮用〔2.5%葡聚糖硫酸钠（DSS）1周+生理盐水2周〕3个周期建立CAC模型。自给予2.5%DSS饮用水起，Clog 12.5，25.0和50.0 mg·kg-1每天ig给药1次至模型建立结束。记录小鼠的体质量，临床症状，小鼠结肠肿瘤的数目和大小，HE染色评价肿瘤的异型性。在CAC小鼠早期炎症阶段，测量小鼠的结肠长度，HE染色和Ki67染色分别评价结肠组织病理变化和结肠组织上皮细胞的增殖水平。在肿瘤形成与发展阶段，Ki67染色评价结肠组织上皮细胞增殖水平，实时荧光定量PCR法检测肿瘤坏死因子α（TNF-α）mRNA的表达，PCR和免疫组化法检测趋化因子（C-X-C结构域）配体2（CXCL2）及其受体CXCR2的表达。结果与模型组相比，Clog 12.5 mg·kg-1可缓解小鼠的临床症状，减小结肠肿瘤平均直径（P<0.05），降低肿瘤异型性（P<0.05）。在CAC早期炎症阶段， Clog 12.5 mg·kg-1可缓解小鼠临床症状（P<0.05）和体质量下降（P<0.01），增加结肠长度（P<0.01），减轻结肠组织炎症损伤（P<0.05），降低上皮细胞增殖水平（P<0.05）；在CAC肿瘤形成与发展阶段，Clog 12.5 mg·kg-1可降低结肠组织上皮细胞增殖水平（P<0.05），减少结肠组织TNF-αmRNA水平、CXCL2和CXCR2 mRNA及蛋白表达水平（P<0.05）。结论 Clog可缓解CAC早期炎症阶段的炎症发展，抑制结肠肿瘤的形成。其抗肿瘤作用可能与减少CXCL2与CXCR2的表达有关。