Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1997-7-22
pubmed:abstractText
Malignancies with neuroendocrine (NE) features such as medullary thyroid cancer (MTC) and small cell lung cancer (SCLC) are prototypic neoplasms arising from peripheral endocrine cells. The mechanisms that regulate the NE phenotype in these tumors and their cellular precursors are not well understood. However, a basic helix-loop-helix transcription factor that is homologous to Drosophila neural fate determination proteins may have a central role. Human achaete-scute homologue-1 (hASH1), a human homologue of the Drosophila achaete-scute complex, is highly expressed in MTC, SCLC, and pheochromocytomas. To determine what mechanisms allow constitutive expression of hASH1 in NE tumors, we cloned human genomic DNA fragments containing the hASH1 gene and characterized its promoter region. We show that hASH1 expression is restricted to NE cell lines by a transcriptionally regulated mechanism. Dual promoters initiate hASH1 transcription, with the predominant site being an evolutionarily conserved initiator (INR) element. Transient transfection studies provide evidence for a generalized enhancer region that has high activity in all cell lines tested. Restriction of hASH1 expression to NE tumor cells depends on two tissue-specific repressor regions, present in the proximal and distal (> 13.5 kb) 5'-flanking region. Understanding the mechanisms of tissue-specific control of hASH1 gene expression provides a useful model to explore regulatory cascades influencing both normal nervous system development and the NE phenotype of tumors such as MTC and SCLC.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
1044-9523
pubmed:author
pubmed:issnType
Print
pubmed:volume
8
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
677-86
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:9186001-Basic Helix-Loop-Helix Transcription Factors, pubmed-meshheading:9186001-Blotting, Northern, pubmed-meshheading:9186001-Chromosome Mapping, pubmed-meshheading:9186001-Chromosomes, Human, Pair 12, pubmed-meshheading:9186001-DNA Footprinting, pubmed-meshheading:9186001-DNA-Binding Proteins, pubmed-meshheading:9186001-Enhancer Elements, Genetic, pubmed-meshheading:9186001-Gene Expression Regulation, Neoplastic, pubmed-meshheading:9186001-Genomic Library, pubmed-meshheading:9186001-Helix-Loop-Helix Motifs, pubmed-meshheading:9186001-Humans, pubmed-meshheading:9186001-Luciferases, pubmed-meshheading:9186001-Neuroendocrine Tumors, pubmed-meshheading:9186001-Plasmids, pubmed-meshheading:9186001-Promoter Regions, Genetic, pubmed-meshheading:9186001-RNA, Messenger, pubmed-meshheading:9186001-Ribonucleases, pubmed-meshheading:9186001-Transcription, Genetic, pubmed-meshheading:9186001-Transcription Factors, pubmed-meshheading:9186001-Transfection, pubmed-meshheading:9186001-Tumor Cells, Cultured
pubmed:year
1997
pubmed:articleTitle
Tissue-specific expression of human achaete-scute homologue-1 in neuroendocrine tumors: transcriptional regulation by dual inhibitory regions.
pubmed:affiliation
Department of Surgery, Baltimore, Maryland 21231, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't