Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
34
pubmed:dateCreated
2002-7-31
pubmed:abstractText
Truncating mutations and homozygous deletions in the hSNF5/INI1/BAF47 subunit of human SWI/SNF complexes occur in most malignant rhabdoid tumors and some other malignancies. How loss of hSNF5 contributes to tumorigenesis remains unknown. Because the SWI/SNF subunit BRG1 is required for RB-mediated cell cycle arrest, we hypothesized that hSNF5 deficiency disrupts RB signaling. Here we demonstrate that unlike BRG1, hSNF5 deficient cells retain functional RB since ectopic expression of either p16ink4a or a constitutively active form of RB (PSM-RB) led to cell cycle arrest. To determine how hSNF5 loss might contribute to tumorigenesis, we used a retrovirus to introduce hSNF5 into multiple deficient cell lines. In all cases, re-expression inhibited colony formation and induced cell cycle arrest characterized by a flattened morphology. Flow cytometry revealed that these cells accumulated in G0/G1. Importantly, arrested cells exhibited strong induction of p16ink4a, hypophosphorylated RB, and down-regulation of cyclin A, suggesting that hSNF5 signals upstream of RB to induce growth arrest. Co-expression of SV40 T/t abolished hSNF5-induced G1 arrest and activation of RB. Likewise, HPV-16 E7 was sufficient to partially overcome cell cycle arrest. These results suggest that hSNF5 loss is not equivalent to BRG1/BRM loss in human tumor cell lines. Furthermore, hSNF5-induced cell cycle arrest of deficient cells is mediated in part through activation of p16ink4a expression. These findings provide insight into mechanisms of hSNF5-mediated tumor suppression.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Antigens, CD44, http://linkedlifedata.com/resource/pubmed/chemical/Bromodeoxyuridine, http://linkedlifedata.com/resource/pubmed/chemical/Chromosomal Proteins, Non-Histone, http://linkedlifedata.com/resource/pubmed/chemical/Cyclin A, http://linkedlifedata.com/resource/pubmed/chemical/Cyclin-Dependent Kinase Inhibitor..., http://linkedlifedata.com/resource/pubmed/chemical/DNA Helicases, http://linkedlifedata.com/resource/pubmed/chemical/DNA-Binding Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Nuclear Proteins, http://linkedlifedata.com/resource/pubmed/chemical/SMARCA4 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/SMARCB1 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/Transcription Factors
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0950-9232
pubmed:author
pubmed:issnType
Print
pubmed:day
8
pubmed:volume
21
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5193-203
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:12149641-Antigens, CD44, pubmed-meshheading:12149641-Bromodeoxyuridine, pubmed-meshheading:12149641-Cell Cycle, pubmed-meshheading:12149641-Chromosomal Proteins, Non-Histone, pubmed-meshheading:12149641-Cyclin A, pubmed-meshheading:12149641-Cyclin-Dependent Kinase Inhibitor p16, pubmed-meshheading:12149641-DNA Helicases, pubmed-meshheading:12149641-DNA-Binding Proteins, pubmed-meshheading:12149641-Flow Cytometry, pubmed-meshheading:12149641-G1 Phase, pubmed-meshheading:12149641-Gene Expression Regulation, Neoplastic, pubmed-meshheading:12149641-Humans, pubmed-meshheading:12149641-Infant, pubmed-meshheading:12149641-Nuclear Proteins, pubmed-meshheading:12149641-Retinal Neoplasms, pubmed-meshheading:12149641-Retinoblastoma, pubmed-meshheading:12149641-Retroviridae, pubmed-meshheading:12149641-Signal Transduction, pubmed-meshheading:12149641-Transcription Factors, pubmed-meshheading:12149641-Transfection, pubmed-meshheading:12149641-Tumor Cells, Cultured, pubmed-meshheading:12149641-Up-Regulation
pubmed:year
2002
pubmed:articleTitle
Re-expression of hSNF5/INI1/BAF47 in pediatric tumor cells leads to G1 arrest associated with induction of p16ink4a and activation of RB.
pubmed:affiliation
Department of Pathology and Laboratory Medicine and The Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina, NC 27599, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.