title: Characterization of human FHL2 transcript variants and gene expression regulation in hepatocellular carcinoma.
abstract: The four-and-a-half LIM protein 2 (FHL2) was originally identified to be expressed abundantly in the heart, as well as in a wide range of tissues demonstrated in various studies. The human FHL2 gene expresses different transcripts which are known to differ only in the 5'UTR region. However, little is known about the functional role of the different variants and the mechanism of gene regulation. In the present study, we characterized the different alternative spliced transcripts of FHL2 by in silico analysis and RT-PCR analysis. A novel transcript variant was identified. The FHL2 gene produces transcripts by different 5' exons, which may be responsible for tissue-specific regulation. To study the mechanism of FHL2 gene regulation, the potential promoter region was investigated. We have identified a functional promoter region upstream of the transcription start site. Deletion mutation analysis of 5' flanking region showed that the fragment from -138 to +292 bp have positive regulatory effect. We identified the binding sites of Pax-5/ZF5 in this region and found that Pax-5 and ZF5 expression in HCC samples had a significant positive correlation with FHL2 expression, suggesting a possible role for these transcription factors in the regulation of FHL2 expression.
authors.affiliation: School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong. fung@cuhk.edu.hk
authors.forename: Chor-Fung
authors.initials: CF
authors.lastname: Ng
authors.forename: Wayne Jun-Wei
authors.initials: WJ
authors.lastname: Zhou
authors.forename: Patrick Kwok-Shing
authors.initials: PK
authors.lastname: Ng
authors.forename: Man-Shan
authors.initials: MS
authors.lastname: Li
authors.forename: Yuen-Keng
authors.initials: YK
authors.lastname: Ng
authors.forename: Paul Bo-San
authors.initials: PB
authors.lastname: Lai
authors.forename: Stephen Kwok-Wing
authors.initials: SK
authors.lastname: Tsui
mesh_terms: D024506:5' Flanking Region; D001665:Binding Sites; D006528:Carcinoma, Hepatocellular / Q000235:genetics*; D045744:Cell Line, Tumor; D005786:Gene Expression Regulation; D018398:Homeodomain Proteins / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D060850:LIM-Homeodomain Proteins; D008113:Liver Neoplasms / Q000235:genetics*; D009124:Muscle Proteins / Q000235:genetics* / Q000378:metabolism; D011401:Promoter Regions, Genetic; D020033:Protein Isoforms; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: C105987:FHL2 protein, human; D018398:Homeodomain Proteins; D060850:LIM-Homeodomain Proteins; D009124:Muscle Proteins; D020033:Protein Isoforms; D014157:Transcription Factors