A novel steroid thyroid hormone receptor-related gene inappropriately expressed in human hepatocellular carcinoma.
We have previously isolated from a human hepatocellular carcinoma a hepatitis B virus integration in a 147-base-pair cellular DNA fragment, similar to steroid- and c-erb-A/thyroid-hormone receptor genes. We have now cloned the corresponding complementary DNA from a human-liver cDNA library. Nucleotide sequence analysis revealed that the overall structure of the cellular gene, which we have named hap, is similar to that of the DNA-binding hormone receptors. That is, it displays two highly conserved regions identified as the putative DNA-binding and hormone-binding domains of the c-erb A/steroid receptors. Six out of seven hepatoma and hepatoma-derived cell-lines express a 2.5-kilobase (kb) hap messenger RNA species which is undetectable in normal adult and fetal livers but present in all non-hepatic tissues analysed. The data suggest that the hap gene product may be a novel ligand-responsive regulatory protein whose inappropriate expression in liver may relate to the hepatocellular carcinogenesis.
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Unité de Recombinaison et Expression Génétique (INSERM U.163, CNRS UA 271), Institut Pasteur, Paris, France.
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Tiollais
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Dejean
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D000595:Amino Acid Sequence; D001483:Base Sequence; D006528:Carcinoma, Hepatocellular / Q000235:genetics*; D004247:DNA / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics*; D005786:Gene Expression Regulation; D006801:Humans; D008113:Liver Neoplasms; D008969:Molecular Sequence Data; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics; D012334:RNA, Neoplasm / Q000235:genetics; D011988:Receptors, Thyroid Hormone / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid; D014157:Transcription Factors / Q000235:genetics
D004268:DNA-Binding Proteins; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D011988:Receptors, Thyroid Hormone; D014157:Transcription Factors; D004247:DNA