Metrnl表达降低促进结直肠癌发生和发展

Downregulation of Metrnl promotes development and progression of colorectal cancer

目的探讨镍纹样蛋白(Metrnl)与结直肠癌的关系及其在结直肠癌发生、发展中的作用。方法利用人体组织芯片分析结直肠癌和癌旁组织中Metrnl的表达与分布(n=30)。收集临床结直肠癌组织和正常人的结直肠组织样本各15例,利用q PCR检测Metrnl mRNA的表达水平。在细胞实验中,通过慢病毒介导sh RNA干扰技术敲减人克隆结肠腺癌细胞系Caco-2细胞中Metrnl表达(Metrnl shRNA组),对照为无关序列(Scr shRNA组),利用CCK-8、caspase 3活性检测试剂盒、膜联蛋白Ⅴ-FITC/PI流式细胞术凋亡检测试剂盒探究细胞在5-氟尿嘧啶作用下的存活和凋亡情况。结果结直肠癌组织中Metrnl蛋白质表达水平高于癌旁组织(P<0.0001),但结直肠癌组织中Metrnl mRNA的相对表达水平低于正常结直肠组织(0.09±0.02 vs 0.22±0.06,P<0.05)。敲减Metrnl可抑制5-氟尿嘧啶诱导的细胞活力降低(P<0.05)。Metrnl shRNA组Caco-2细胞中caspase 3相对活性、凋亡细胞比例均低于Scr sh RNA组[1.04±0.27 vs 1.67±0.44、(12.53±6.69)%vs(26.56±10.89)%,P均<0.05]。结论在结直肠癌中,分泌蛋白Metrnl在局部癌组织中蓄积,但Metrnl转录降低可能促进了结直肠癌的发生、发展。

Objective To explore the relationship between meteorin-like protein(Metrnl)and colorectal cancer and its role in the development and progression of colorectal cancer.Methods Expression and distribution of Metrnl in the colorectal cancer and paracancerous tissue were analyzed by human tissue microarray(n=30).Fifteen clinical colorectal cancer tissue samples and 15 normal human colorectal tissue samples were collected,and the expression level of Metrnl mRNA was detected by quantitative polymerase chain reaction.In the cell experiment,the expression of Metrnl in human colon cancer epithelial cell line Caco-2 was knocked down by lentivirus-mediated short hairpin RNA(shRNA)interference technology(Metrnl shRNA group),and unrelated sequence was used as control(Scr shRNA group).Cell counting kit 8,cysteine aspartic acid specific protease 3(caspase 3)activity assay kit and annexinⅤ-fluorescein isothiocyanate/propidium iodide flow cytometry apoptosis detection kit were used to detect the cell viability and apoptosis under the treatment of 5-fluorouracil.Results Metrnl protein was significantly higher in the human colorectal cancer tissue compared with the paracancerous tissue(P<0.0001),but the level of Metrnl mRNA in the colorectal cancer tissue was significantly lower compared with the normal colorectal tissue(0.09±0.02 vs 0.22±0.06,P<0.05).Knockdown of Metrnl blocked the decline of cell viability induced by 5-fluorouracil(P<0.05).The activity of caspase 3 and the proportion of apoptotic cells in the Metrnl shRNA group were significantly lower than those in the Scr shRNA group(1.04±0.27 vs 1.67±0.44,[12.53±6.69]%vs[26.56±10.89]%,both P<0.05).Conclusion Secretory protein Metrnl is accumulated in the colorectal cancer tissue,but Metrnl transcription decrease in colorectal cancer may promote the development and progression of colorectal cancer.