title: Identification of miRNAs that specifically target tumor suppressive KLF6-FL rather than oncogenic KLF6-SV1 isoform.
abstract: The Krüppel like factor 6 (KLF6) gene encodes multiple protein isoforms derived from alternative mRNA splicing, most of which are intimately involved in hepatocarcinogenesis and tumor progression. Recent bioinformatics analysis shows that alternative mRNA splicing of the KLF6 gene produces around 16 alternatively spliced variants with divergent or even opposing functions. Intriguingly, the full-length KLF6 (KLF6-FL) is a tumor suppressor gene frequently inactivated in liver cancer, whereas KLF6 splice variant 1 (KLF6-SV1) is an oncogenic isoform with antagonistic function against KLF6-FL. Compelling evidence indicates that miRNA, the small endogenous non-coding RNA (ncRNA), acts as a vital player in modulating a variety of cellular biological processes through targeting different mRNA regions of protein-coding genes. To identify the potential miRNAs specifically targeting KLF6-FL, we utilized bioinformatics analysis in combination with the luciferase reporter assays and screened out two miRNAs, namely miR-210 and miR-1301, specifically targeted the tumor suppressive KLF6-FL rather than the oncogenic KLF6-SV1. Our in vitro experiments demonstrated that stable expression of KLF6-FL inhibited cell proliferation, migration and angiogenesis while overexpression of miR-1301 promoted cell migration and angiogenesis. Further experiments demonstrated that miR-1301 was highly expressed in liver cancer cell lines as well as clinical specimens and we also identified the potential methylation and histone acetylation for miR-1301 gene. To sum up, our findings unveiled a novel molecular mechanism that specific miRNAs promoted tumorigenesis by targeting the tumor suppressive isoform KLF6-FL rather than its oncogenic isoform KLF6-SV1.
authors.affiliation: Croucher Laboratory for Human Genomics, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, P.R. China; School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, P.R. China.
authors.forename: Wei-Cheng
authors.initials: WC
authors.lastname: Liang
authors.affiliation: School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, P.R. China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Clinical Laboratory, Nanshan Affiliated Hospital of Guangdong Medical College, Shenzhen, 518052, P.R. China.
authors.forename: Li-Jia
authors.initials: LJ
authors.lastname: Xiao
authors.affiliation: Croucher Laboratory for Human Genomics, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, P.R. China; School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, P.R. China.
authors.forename: Yu-Bing
authors.initials: YB
authors.lastname: Wang
authors.affiliation: Guangzhou Institute of Advanced Technology, Chinese Academy of Sciences, Guangzhou, 510000, P.R. China.
authors.forename: Wei-Ming
authors.initials: WM
authors.lastname: Fu
authors.affiliation: School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, P.R. China.
authors.forename: Wei-Mao
authors.initials: WM
authors.lastname: Wang
authors.affiliation: Department of Gastroenterology, Hebei Key Laboratory of Gastroenterology, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, 230000, P.R. China.
authors.forename: Hui-Qing
authors.initials: HQ
authors.lastname: Jiang
authors.affiliation: Department of Gastroenterology, Hebei Key Laboratory of Gastroenterology, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, 230000, P.R. China.
authors.forename: Wei
authors.initials: W
authors.lastname: Qi
authors.affiliation: School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, P.R. China.
authors.forename: David Chi-Cheong
authors.initials: DC
authors.lastname: Wan
authors.affiliation: School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, P.R. China.
authors.forename: Jin-Fang
authors.initials: JF
authors.lastname: Zhang
authors.affiliation: Croucher Laboratory for Human Genomics, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, P.R. China; School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, P.R. China.
authors.forename: Mary Miu-Yee
authors.initials: MM
authors.lastname: Waye
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000235:genetics* / Q000378:metabolism; D045744:Cell Line, Tumor; D002465:Cell Movement; D049109:Cell Proliferation; D015972:Gene Expression Regulation, Neoplastic; D057809:HEK293 Cells; D056945:Hep G2 Cells; D006801:Humans; D000075723:Kruppel-Like Factor 6; D051741:Kruppel-Like Transcription Factors / Q000235:genetics / Q000378:metabolism*; D008113:Liver Neoplasms / Q000235:genetics* / Q000378:metabolism; D008745:Methylation; D035683:MicroRNAs / Q000378:metabolism*; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: C105465:KLF6 protein, human; D000075723:Kruppel-Like Factor 6; D051741:Kruppel-Like Transcription Factors; C572423:MIRN1301 microRNA, human; C543800:MIRN210 microRNA, human; D035683:MicroRNAs; D020033:Protein Isoforms; D011518:Proto-Oncogene Proteins
keywords: Alternative splicing; KLF6; miRNA