Document Detail


Microsatellite deletions in the c-myb transcriptional attenuator region associated with over-expression in colon tumour cell lines.
MedLine Citation:
PMID:  9135073     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
In the hemopoietic system c-myb expression is required for proliferation of immature cells and its down-regulation is required for differentiation. In colonic mucosa c-myb expression occurs at levels comparable to immature hemopoietic cells. Inhibition of c-myb expression in colon cell lines, using anti-sense oligonucleotides, indicates that c-myb expression is required for proliferation. However, the mechanism of c-myb regulation during colon cell differentiation has not been explored. Using the LIM1215 and CaCo-2 colon carcinoma cell lines induced to differentiate with sodium butyrate, we demonstrate that c-myb mRNA is down-regulated as an early event in differentiation by a mechanism involving transcriptional attenuation in intron 1. By analogy with procaryotic and eucaryotic genes, transcriptional attenuation probably occurs in a region containing nineteen consecutive thymidine residues. Computer prediction of the secondary structure of the nascent mRNA chain encoded by this region suggests a strong potential for stem-loop formation. Sequence analysis of several colon tumour cell lines reveals mutations in this region that may disrupt transcriptional attenuation and result in the increased c-myb expression observed in colon tumours and tumour cell lines.
Authors:
M A Thompson; R Flegg; E H Westin; R G Ramsay
Related Documents :
17237363 - Dictyostelium myb transcription factors function at culmination as activators of ancill...
11997503 - The transcription factor b-myb is maintained in an inhibited state in target cells thro...
14499633 - Demethylation of the human telomerase catalytic subunit (htert) gene promoter reduced h...
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Oncogene     Volume:  14     ISSN:  0950-9232     ISO Abbreviation:  Oncogene     Publication Date:  1997 Apr 
Date Detail:
Created Date:  1997-05-23     Completed Date:  1997-05-23     Revised Date:  2004-11-17    
Medline Journal Info:
Nlm Unique ID:  8711562     Medline TA:  Oncogene     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  1715-23     Citation Subset:  IM    
Affiliation:
Ludwig Institute for Cancer Research, PO Royal Melbourne Hospital, Australia.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Base Sequence
Cell Differentiation
Colonic Neoplasms / genetics,  pathology
Down-Regulation
Gene Expression Regulation, Neoplastic
Humans
Hydrogen Bonding
Introns
Microsatellite Repeats
Nucleic Acid Conformation
Operon*
Polymorphism, Single-Stranded Conformational
Proto-Oncogene Proteins / genetics*
Proto-Oncogene Proteins c-myb
RNA, Messenger / genetics
RNA, Neoplasm / genetics
Sequence Deletion
Trans-Activators / genetics*
Transcription, Genetic
Tumor Cells, Cultured
Chemical
Reg. No./Substance:
0/Proto-Oncogene Proteins; 0/Proto-Oncogene Proteins c-myb; 0/RNA, Messenger; 0/RNA, Neoplasm; 0/Trans-Activators

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Rho regulates association of both the ERM family and vinculin with the plasma membrane in MDCK cells...
Next Document:  Overexpression of insulin-like growth factor-1 induces hyperplasia, dermal abnormalities, and sponta...