miR-26b对结直肠癌侵袭和转移的影响

Effect of miR-26b on the invasion and metastasis of colorectal cancer

目的探讨miR-26b在结直肠癌侵袭与转移中的作用。方法提取公共芯片数据库数据，分析miR-26b表达水平与淋巴结转移的关系。选用Caco2和DLD1两种结直肠癌细胞系，应用慢病毒感染的方法，构建miR-26b高表达结直肠癌细胞系。通过Transwell迁移和侵袭实验及划痕愈合实验分析上调miR-26b表达对结直肠癌细胞侵袭和转移能力的影响。通过成球实验分析上调miR-26b表达对结直肠癌细胞干细胞表型的影响。结果芯片检测结果显示，有淋巴结转移的结直肠癌患者肿瘤组织中miR-26b表达水平较无淋巴结转移的患者明显升高[（12.04±0.20）比（11.31±0.19），t=2.646，P = 0.010]。体外实验部分，Transwell实验发现，miR-26b高表达的结直肠癌细胞的侵袭细胞数[（16.40±1.36）比（3.80±0.86），t=7.814，P=0.000]和迁移细胞数[（33.40±2.93）比（8.80±2.40），t=6.505，P=0.000]较miR-26b低表达的细胞系显著增多。划痕愈合实验也证实，miR-26b高表达的结直肠癌细胞迁移速度明显加快。miR-26b高表达的结直肠癌细胞在成球速度及成球密度方面均高于miR-26b低表达的细胞系，实验第10天前者球囊内的肿瘤细胞数量显著多于后者[Caco2细胞系：（168.3±11.7）比（54.2±10.8），t=7.185，P=0.002；DLD1细胞系：（4 076.0±409.8）比（1 613.0±210.1），t=5.349，P=0.006]。结论miR-26b可促进结直肠癌细胞的迁移及侵袭能力，并增强肿瘤细胞的干细胞表型，从而促进结直肠癌的浸润与转移。

Objective To investigate the role of miR-26b in the invasion and metastasis of colorectal cancer. Methods Data of public chip databases were extracted to analyze the relationship between miR-26b expression and lymph node metastasis. Two types of colorectal cancer cell lines, Caco2 and DLD1, were selected, and the miR-26b-high colorectal cancer cell line was constructed using the method of lentivirus infection. The effects of up-regulating miR-26b expression on the invasion and metastasis of eolorectal cancer cells were analyzed by Transwell migration and invasion experiment and wound healing assay. The effect of up-regulating miR-26b expression on stem cell phenotype of colorectal cancer cells was analyzed by sphere-formation assay. Results The microarray detection results showed that the expression of miR-26b in tumor tissues of patients with lymph node metastasis was significantly higher than those without lymph node metastasis [（12.04±0.20） vs. （11.31±0.19）, t=2.646, P= 0.010]. In the in vitro experiment section, the Transwell experiment results showed that the number of invasive ceils [（16.40±1.36） vs. （3.80±0.86）, t=7.814, P=0.000] and migrating cells [（33.40±2.93） vs. （8.80±2.40）, t=6.505, P=0.000] in miR-26b-high colorectal cancer cells was significantly higher as compared to miR-26b-low cells （all P〈0.05）. Would healing assay also confirmed that the migration speed of miR-26b-high colorectal cancer cells was significantly accelerated. Both the rate and the density of sphere formation were higher in miR-26b-high colorectal cancer cells than those in miR-26b-low colorectal cancer cells [ Caco2 ： （ 168.3±11.7） vs. （54.2±10.8）, t=7.185, P=0.002; DLDI：（4 076.0±409.8） vs.（1 613.0±210.1）, t=5.349, P=0.006]. Conclusion rniR-26b may promote the invasion and metastasis of eolorectal cancer by accelerating the migration and invasion of eolorectal cancer cells and enhancing the stem cell phenotype of tumor cells.