Linked Life Data

8552398

Source:http://linkedlifedata.com/resource/pubmed/id/8552398

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1996-2-20
pubmed:abstractText
Cyclin D1 can bind and phosphorylate the product (pRb) of the retinoblastoma gene (RB-1) and recent evidence suggests pRb, in turn, may regulate cyclin D1 protein expression. In transformed cell lines, loss of pRb activity strongly correlates with a decrease in cyclin D1 protein expression, and conversely, introduction of pRb can induce cyclin D1 promoter activity. We show here that pRb does not regulate cyclin D1 directly as basal and serum-stimulated levels of cyclin D1 protein and kinase activity are similar in wildtype and pRb-deficient primary mouse embryonic fibroblasts (MEFs). These observations suggest that the suppression of cyclin D1 in pRb-minus tumour cell lines requires both loss of pRb and at least one additional genetic event. We have determined that constitutive, ectopic Myc expression in pRb-deficient, but not wildtype, MEFs suppresses cyclin D1 protein expression and kinase activity. Regulation is evident at either the level of RNA or protein expression. Phenotypically, pRb-deficient MEFs consistently exhibited a delayed growth response in comparison to wildtype MEFs. This growth delay is abrogated in pRb-deficient MEFs which are expressing ectopic Myc protein, coincident with the loss of cyclin D1 protein expression. Moreover, these cells exhibit an increased proliferative capacity, and they no longer show contact inhibition. Our results support a cross-regulatory mechanism between Myc, pRb and cyclin D1 and suggest a novel role for cyclin D1 in tumorigenesis.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0950-9232
pubmed:author
pubmed:issnType
Print
pubmed:day
4
pubmed:volume
12
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
43-52
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Loss of Rb and Myc activation co-operate to suppress cyclin D1 and contribute to transformation.
pubmed:affiliation
Department of Microbiology, Hospital for Sick Children Research Institute, Toronto, Ontario, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't