title: Oncofetal H19-derived miR-675 regulates tumor suppressor RB in human colorectal cancer.
abstract: H19 is an imprinted oncofetal non-coding RNA recently shown to be the precursor of miR-675. The pathophysiological roles of H19 and its mature product miR-675 to carcinogenesis have, however, not been defined. By quantitative reverse transcription-polymerase chain reaction, both H19 and miR-675 were found to be upregulated in human colon cancer cell lines and primary human colorectal cancer (CRC) tissues compared with adjacent non-cancerous tissues. Subsequently, the tumor suppressor retinoblastoma (RB) was confirmed to be a direct target of miR-675 as the microRNA suppressed the activity of the luciferase reporter carrying the 3'-untranslated region of RB messenger RNA that contains the miR-675-binding site. Suppression of miR-675 by transfection with anti-miR-675 increased RB expression and at the same time, decreased cell growth and soft agar colony formation in human colon cancer cells. Reciprocally, enhanced miR-675 expression by transfection with miR-675 precursor decreased RB expression, increased tumor cell growth and soft agar colony formation. Moreover, the inverse relationship between the expressions of RB and H19/miR-675 was also revealed in human CRC tissues and colon cancer cell lines. Our findings demonstrate that H19-derived miR-675, through downregulation of its target RB, regulates the CRC development and thus may serve as a potential target for CRC therapy.
authors.affiliation: Department of Biochemistry, University of Hong Kong, Shatin, N.T., Hong Kong Special Administrative Region, China.
authors.forename: Wing Pui
authors.initials: WP
authors.lastname: Tsang
authors.forename: Enders K O
authors.initials: EK
authors.lastname: Ng
authors.forename: Simon S M
authors.initials: SS
authors.lastname: Ng
authors.forename: Hongchuan
authors.initials: H
authors.lastname: Jin
authors.forename: Jun
authors.initials: J
authors.lastname: Yu
authors.forename: Joseph J Y
authors.initials: JJ
authors.lastname: Sung
authors.forename: Tim Tak
authors.initials: TT
authors.lastname: Kwok
mesh_terms: D020413:3' Untranslated Regions / Q000235:genetics; D000230:Adenocarcinoma / Q000235:genetics* / Q000473:pathology; D001665:Binding Sites; D002455:Cell Division; D002471:Cell Transformation, Neoplastic / Q000235:genetics*; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000473:pathology; D015536:Down-Regulation; D005347:Fibroblasts / Q000166:cytology; D020869:Gene Expression Profiling; D006801:Humans; D035683:MicroRNAs / Q000235:genetics / Q000502:physiology*; D009363:Neoplasm Proteins / Q000502:physiology*; D034622:RNA Interference; D062085:RNA, Long Noncoding; D012334:RNA, Neoplasm / Q000235:genetics / Q000502:physiology*; D034741:RNA, Small Interfering / Q000494:pharmacology; D022661:RNA, Untranslated / Q000235:genetics*; D016160:Retinoblastoma Protein / Q000502:physiology*; D014162:Transfection; D014407:Tumor Cells, Cultured / Q000473:pathology; D014410:Tumor Stem Cell Assay
chemical_list: D020413:3' Untranslated Regions; C094335:H19 long non-coding RNA; C548379:MIRN675 microRNA, human; D035683:MicroRNAs; D009363:Neoplasm Proteins; D062085:RNA, Long Noncoding; D012334:RNA, Neoplasm; D034741:RNA, Small Interfering; D022661:RNA, Untranslated; D016160:Retinoblastoma Protein