长链非编码RNARUNX1-IT1通过靶向miR-21对结直肠癌细胞迁移和侵袭的影响

目的：探讨长链非编码 RNA(lncRNA)RUNX1-IT1在结直肠癌中的表达及其对结直肠癌细胞侵袭和迁移的影响机制。方法：收集2017年1月—2019年1月于河北北方学院附属第一医院进行根治性手术切除的结直肠癌组织标本62例及其相应的癌旁正常组织标本，采用荧光定量PCR(qPCR)法检测结直肠癌组织和其相应的癌旁组织中lncRNA RUNX1-IT1的表达。并培养人结直肠癌细胞系(SW480、SW620、HCT-116)和人正常结直肠上皮细胞系(FHC)，qPCR检测细胞系中 lncRNA RUNX1-IT1和 miR-21的表达水平，选择最适细胞系用于后续实验。通过上调或下调SW480细胞中lncRNA RUNX1-IT1和miR-21的表达后，采用qPCR检测lncRNA RUNX1-IT1和miR-21的表达水平，双荧光素酶报告基因实验验证lncRNA RUNX1-IT1和miR-21的靶向关系，Transwell实验检测SW480细胞侵袭和迁移能力。结果：qPCR检测结果显示，与癌旁正常组织比较，lncRNA RUNX1-IT1在结直肠癌组织中表达降低(P<0.05)，而miR-21在结直肠癌组织中表达升高(P<0.05)，且lncRNA RUNX1-IT1与miR-21在结直肠癌组织中的表达呈负相关(r=-0.275，P=0.031)。与正常结直肠 FHC细胞相比，lncRNA RUNX1-IT1在 3种结直肠癌细胞系中的表达水平均显著降低(均为P<0.05)，而miR-21均显著升高(均为P<0.05)，且SW480细胞最明显，故后续采用SW480细胞系进行实验。双荧光素酶报告基因实验证实lncRNA RUNX1-IT1靶向调节miR-21的表达；与对照组相比，过表达lncRNA RUNX1-IT1可抑制SW480细胞侵袭和迁移能力(P<0.05)；抑制 miR-21表达可抑制 SW480细胞侵袭和迁移能力(P<0.05)；上调 miR-21表达可逆转过表达 lncRNARUNX1-IT1对 SW480细胞侵袭和迁移的抑制作用(P<0.05)。结论：LncRNA RUNX1-IT1在结直肠癌中表达下调，lncRNARUNX1-IT1通过靶向miR-21调控SW480细胞侵袭和迁移。

Effects of long-chain noncoding RNA RUNX1-IT1 on migration and invasion of colorectal cancer cells

OBJECTIVE: To investigate expression of long-chain noncoding RNA (lncRNA) RUNX1-IT1 in colorectal cancer,and its mechanisms on invasion and migration of colorectal cancer cells.METHODS: Sixty-two colorectal cancer tissue samples and their corresponding adjacent tissues were collected from the First Affiliated Hospital of Hebei North University from January 2017 to January 2019.Expressions of lncRNA RUNX1-IT1 in both tissues were detected using fluorescence quantitative PCR (qPCR).The human colorectal cancer cell lines (SW480,SW620,HCT-116) and the human normal colorectal epithelial cell lines (FHC) were cultured.Expression levels of lncRNA RUNX1-IT1 and miR-21 in the cell lines were detected by qPCR.The most suitable cell lines were selected for subsequent investigations.After up-regulating or down-regulating the expression of lncRNA RUNX1-IT1 and miR-21 in SW480 cells,their expression levels were detected by qPCR,the targeting relationship between lncRNA RUNX1-IT1 and miR-21 was verified by the double luciferase reporter gene assay.The invasion and migration abilities of SW480 cells were detected by Transwell assay.RESULTS: The results of qPCR showed that the expression of lncRNA RUNX1-IT1 was lower in colorectal cancer tissues than that in adjacent tissues (P<0.05),while the expression of miR-21 was higher in colorectal cancer tissues (all P<0.05).There was a negative correlation between the expression of lncRNA RUNX1-IT1 and miR-21 in colorectal cancer tissues (r=-0.275,P=0.031).Compared with normal colorectal FHC cells,the expression levels of lncRNA RUNX1-IT1 in the three colorectal cancer cell lines were decreased significantly (all P<0.05),while that for miR-21 was increased significantly (all P<0.05).These effects were most obvious in the SW480 cells.Therefore,SW480 cell lines were used for subsequent experiments.The dual luciferase reporter assay confirmed that lncRNA RUNX1-IT1 targeted to regulate the expression of miR-21.Compared with the control group,overexpression of lncRNA RUNX1-IT1 inhibited the invasion and migration of SW480 cells (P<0.05).Inhibition of miR-21 expression reduced the invasion and migration of SW480 cells (P<0.05).Up-regulation of miR-21 expression inversely reversed the inhibitory effect of lncRNA RUNX1-IT1 on the invasion and migration of SW480 cells (P<0.05).CONCLUSION: LncRNA RUNX1-IT1 expression was down-regulated in colorectal cancers and it regulated SW480 cell invasion and migration by targeting miR-21.