LncRNA AL133467.1作为miR-661的ceRNA抑制乳腺癌细胞增殖和侵袭

LncRNA AL133467.1 Acts as the ceRNA of miR-661 to Inhibit the Proliferation and Invasion of Breast Cancer Cells

长非编码RNAs(long non-coding RNAs,lncRNAs)在多种肿瘤中异常表达并参与肿瘤的发生发展。然而,众多lncRNAs在肿瘤的表达及功能尚未完全阐明。本文通过分析TCGT数据库113例正常乳腺组织和1109例乳腺癌组织发现,LncRNA AL133467.1在乳腺癌组织中低表达,并与乳腺癌患者的预后不良呈负相关;实时荧光定量PCR(qRT-PCR)结果也发现,AL133467.1在乳腺癌细胞中表达明显低于正常乳腺上皮细胞。在相对低表达的乳腺癌细胞SKBR3和BT474中过表达AL133467.1,细胞计数和平板克隆结果发现,过表达AL133467.1能明显抑制乳腺癌细胞的增殖和克隆形成能力(P<0.01);细胞划痕和Transwell实验显示,与对照组相比,过表达AL133467.1的乳腺癌细胞的迁移和侵袭能力明显降低(P<0.01)。miRDB数据库显示,AL133467.1与miR-661存在结合位点,miR-661可以靶向结合ErbB2受体酪氨酸激酶2传感器2(transducer of ERBB2,2,TOB2);qRT-PCR结果显示,miR-661在乳腺癌细胞中高表达,并且与乳腺癌患者的预后不良呈正相关(P<0.001);荧光素酶报告基因结果显示,AL133467.1与miR-661存在特异性结合(P<0.01),过表达AL133467.1能抑制乳腺癌细胞中miR-661的表达(P<0.0001);同时,转染miR-661 mimics能消除过表达AL133467.1对乳腺癌细胞的抑制侵袭作用(P<0.001);此外,qRT-PCR和Western印迹结果显示,过表达AL133467.1能上调TOB2的mRNA(P<0.0001)和蛋白质水平,同时转染miR-661 mimics乳腺癌细胞中TOB2的mRNA(P<0.0001)和蛋白质水平明显被抑制。综上所述,AL133467.1作为miR-661的竞争性RNA上调TOB2的表达,从而抑制乳腺癌细胞增殖和侵袭。

Long non-coding RNAs(LncRNAs)are abnormally expressed in a variety of tumors and participate in the occurrence and development of tumors.However,the expression and function of many LncRNAs in tumors have not been fully clarified.In this paper,113 normal breast tissues and 1109 breast cancer tissues were analyzed in TCGT database.LncRNA AL133467.1 was found to be lowly expressed in breast cancer tissues and negatively correlated with poor prognosis of breast cancer patients.The expression of AL133467.1 in breast cancer cells was significantly lower than that in normal breast epithelial cells.We overexpressed AL133467.1 in relatively low-expression breast cancer cells SKBR3 and BT474,and cell count and plate colony-formation experiments showed that overexpression of AL133467.1 could significantly inhibit the proliferation and colony formation of breast cancer cells(P<0.01).Cell scratch and Transwell assays showed that the migration and invasion ability of breast cancer cells overexpressing AL133467.1 was significantly reduced compared with the control group(P<0.01).MiRDB database showed that AL133467.1 had binding sites with miR-661.miR-661 could bind the transducer of ErbB2,2(ErbB2,2,TOB2).qRT-PCR showed that miR-661 was highly expressed in breast cancer cells and positively correlated with poor prognosis of breast cancer patients(P<0.001).Luciferase reporter assays showed that AL133467.1 had specific binding to miR-661(P<0.01).AL133467.1 overexpression could inhibit the expression of miR-661 in breast cancer cells(P<0.0001).Transfection of miR-661 mimics eliminated the inhibitory effect of overexpression of AL133467.1 on breast cancer cells(P<0.001).In addition,qRT-PCR and Western blotting results showed that overexpression of AL133467.1 up-regulated TOB2 mRNA(P<0.0001)and protein levels.But when miR-661 mimics were transfected,TOB2 mRNA(P<0.0001)and protein levels were significantly inhibited.In conclusion,as a competitive endogenous RNA of miR-661.AL133467.1 promotes the expression of TOB2,thereby inhibiting the proliferation and invasion of breast cancer cells.