摘要
目的探讨人结直肠癌中表观沉默蛋白Bmil和Notchl的蛋白表达与结直肠癌病理特征的关系，观察Notch通路对结直肠癌细胞增殖凋亡及Bmil表达的影响。方法应用免疫组织化学技术（SP法）检测85例结直肠癌组织及其邻近正常肠黏膜中Notchl及Bmil的蛋白表达；将Notchl通路中叫．分泌酶抑制剂DAPT，作用于结肠癌SW480细胞株，运用噻唑蓝（MIT）比色法检测细胞增殖状态；流式细胞仪观察其对细胞凋亡的影响，Westernblot检测ICN及Bmil蛋白的表达。结果结直肠癌组织中Notchl和Broil蛋白表达的阳性率明显高于正常肠黏膜（P〈0．05），分别为61．2％（52／85）对15．3％（13／85）和56．5％（48／85）对17．6％（15／85）；Bmil表达率与Notchl表达率呈正相关（r=0．625，P〈0．01），并与肿瘤分化程度、分期及淋巴结转移有关（P〈0．05）；阻断Notchl通路（DAPT）可抑制SW480细胞的增殖，诱导其凋亡，作用12、24、36h后其增殖抑制率分别为13．1％、17．5及22．6％，而凋亡率为32．7％、45．6％及67．2％；同时Notchl胞内活性段ICN随作用时间延长而下降，而Bmil表达水平也逐渐降低。结论结直肠癌中Broil与Notchl表达密切相关，阻断Notch通路可抑制Broil表达，同时可抑制结肠癌细胞的增殖，促进其凋亡。
Objective To investigate the Notchl and Broil protein levels in human colorectal cancer samples and their correlation with clinicopathological parameters of eolorectal cancer and reveal the mechanism of Notch signal transduction pathway regulating the expression of Bmil in colorecta caner cells. Methods We assessed Notchl and Bmil protein levels in 85 eases of colorectal cancer and adjacent normal tissue by immunohistochemistry. SW480 cells were treated with DAPT （v-seeretase inhibitor） at different time points. MTF assay and flow cytometry were used to measure the proliferation and apoptosis of SW480 cells. The expression of ICN and Bmil were measured by Western blotting. Results Notchl and Bmil protein levels were increased in colorectal cancer cells as compared with adjacent normal mucosa （P 〈0. 05 ）. The positive rate of Notchl and Bmil expression in gastric cancer tissues was 61.2% （52/85） and 56. 5% （48/85）, significantly higher than in the adjacent noncancerous tissues [ 15.3% （13/85） and 17. 6% （15/85）, respectively ]. The overexpression of Notchl and Bmil was related to dif- ferentiation and lymph nodes metastasis in colorectal cancer （ P 〈 O. 05 ）. There was a positive correlation between Notchl and Bmil protein levels （ r = 0. 625, P 〈 0.01 ）. Treating SW480 with DAPT resulted in significant growth inhibition and apoptosis induction. Inhibition ratio for cell proliferation after treatment with DAPT （ 12, 24 and 36 h） was 13.1%, 17.5% and 22. 6%, respectively; Apoptosis rate was 32. 7%, 45.6% and 67.2%, respectively. DAPT could down,regulated ICN and Bmil. Conclusion Overexpression of Notehl and Bmil may play a critical role in the development of colorectal cancer. Notch signal transduction pathway regulates the expression of Bmil in coloreetal cancer cells. Blockade of Notchl signal pathway can inhibit proliferation and accelerate apoptosis of colorectal cancer cells.
出处
《中华实验外科杂志》
CAS
CSCD
北大核心
2011年第9期1488-1491,共4页
Chinese Journal of Experimental Surgery
基金
国家自然科学基金资助项目（30872470）
