1.Long Noncoding RNA HEIH Promotes Colorectal Cancer Tumorigenesis via Counteracting miR-939-Mediated Transcriptional Repression of Bcl-xL.
Chunhui CUI ; Duanyang ZHAI ; Lianxu CAI ; Qiaobin DUAN ; Lang XIE ; Jinlong YU
Cancer Research and Treatment 2018;50(3):992-1008
PURPOSE: Studies have found that long noncoding RNA HEIH (lncRNA-HEIH) is upregulated and facilitates hepatocellular carcinoma tumor growth. However, its clinical significances, roles, and action mechanism in colorectal cancer (CRC) remains unidentified. MATERIALS AND METHODS: lncRNA-HEIH expression in CRC tissues and cell lines was measured by quantitative real-time polymerase chain reaction. Cell CountingKit-8, ethynyl deoxyuridine incorporation assay, terminal deoxynucleotidyl transferase dUTP nick end labeling staining, and nude mice xenografts assays were performed to investigate the roles of lncRNA-HEIH. RNA pull-down, RNA immunoprecipitation, chromatin immunoprecipitation, and luciferase reporter assays were performed to investigate the action mechanisms of lncRNA-HEIH. RESULTS: In this study, we found that lncRNA-HEIH is significantly increased in CRC tissues and cell lines. lncRNA-HEIH expression is positively associated with tumor size, invasion depth, and poor prognosis of CRC patients. Enhanced expression of lncRNA-HEIH promotes CRC cell proliferation and decreases apoptosis in vitro, and promotes CRC tumor growth in vivo. Whereas knockdown of lncRNA-HEIH inhibits CRC cell proliferation and induces apoptosis in vitro, and suppresses CRC tumor growth in vivo. Mechanistically, lncRNA-HEIH physically binds to miR-939. The interaction between lncRNA-HEIH and miR-939 damages the binding between miR-939 and nuclear factor κB (NF-κB), increases the binding of NF-κB to Bcl-xL promoter, and promotes the transcription and expression of Bcl-xL. Moreover, Bcl-xL expression is positively associatedwith lncRNA-HEIH in CRC tissues. Blocking the interaction between lncRNA-HEIH and miR-939 abolishes the effects of lncRNA-HEIH on CRC tumorigenesis. CONCLUSION: This study demonstrated that lncRNA-HEIH promotes CRC tumorigenesis through counteracting miR-939-mediated transcriptional repression of Bcl-xL, and suggested that lncRNA-HEIH may serve as a prognostic biomarker and therapeutic target for CRC.
Animals
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Apoptosis
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Carcinogenesis*
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Carcinoma, Hepatocellular
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Cell Line
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Cell Proliferation
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Chromatin Immunoprecipitation
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Colorectal Neoplasms*
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Deoxyuridine
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DNA Nucleotidylexotransferase
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Heterografts
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Humans
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Immunoprecipitation
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In Vitro Techniques
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Luciferases
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Mice
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Mice, Nude
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Prognosis
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Real-Time Polymerase Chain Reaction
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Repression, Psychology*
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RNA
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RNA, Long Noncoding*