反义 miR-224在结肠癌组织中的表达及其对癌细胞增殖的影响

摘要

目的探讨微小 RNA(miRNA)miR-224在结肠癌组织中的表达，以及对体外癌细胞增殖和凋亡的影响。方法收集2011年2月至2014年3月行手术治疗的134例结肠癌和癌旁组织标本，利用实时荧光定量聚合酶链反应(Real-time PCR)检测标本中 miR-224表达情况；对人结肠癌细胞 SW480进行 miR-224反义寡核苷酸转染并培养，利用克隆形成实验和流式细胞仪检测 miR-224反义寡核苷酸对 SW480细胞增殖和凋亡的影响，利用 Real-time PCR 和 Western blot 法对不同转染组细胞中 Bcl-2表达情况进行检测。结果miR-224在结肠癌组织中相对表达水平显著高于癌旁组织(P <0.05)；反义 miR-224组人结肠癌 SW480细胞克隆形成率显著低于对照组，而细胞凋亡指数则高于对照组，差异均具有统计学意义(P <0.05)；反义 miR-224组细胞 Bcl-2相对表达量和蛋白相对表达量均低于对照组(P <0.05)。结论miR-224在结肠癌组织中呈高表达，减少 miR-224表达可抑制结肠癌细胞增殖，并加速细胞凋亡，有可能成为结肠癌早期发现及基因治疗的新靶位。%Objective To explore the expression of miR-224 in colon cancer and examine its effect on the proliferation and apoptosis of cancer cell.Methods A total of 134 cases of colon cancer and adjacent tissue specimens were collected from Feb.201 1 to Mar.2014.And the expression of miR-224 was detected by real-time polymerase chain reaction (PCR).Human colon cancer cell SW480 was transfected by miR-224 antisense oligonucleotide and cultured.The effects of miR-224 antisense oligonucleotide on cellular proliferation and apoptosis were detected by colony formation assay and flow cytometry.And the expressions of Bcl-2 in differentially transfected cells were detected by real-time PCR and Western blot.Results The relative expression of miR-224 was significantly higher in colon cancer tissue than that in adjacent tissues.And the difference was statistically significant (P <0.05). The colony formation rate of SW480 human colon cancer cell in antisense miR-224 group was signifi-cantly lower than that in control group while the apoptotic index was higher.And the differences were statistically significant (P <0.05).The relative expressions of Bcl-2 mRNA and protein were lower in antisense miR-224 group than those in control group.And the differences were all statistically signifi-cant (P <0.05).Conclusions There is an over-expression of miR-224 in colon cancer.And its down-regulation may effectively inhibit the proliferation and accelerate the apoptosis of colon cancer cell.It will probably become a new target for early detection and gene therapy of colon cancer.