Linked Life Data

18006821

Source:http://linkedlifedata.com/resource/pubmed/id/18006821

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
22
pubmed:dateCreated
2007-11-16
pubmed:abstractText
Overexpression of cyclin D1 is associated with many cancers, and its overexpression is especially associated with a poor prognosis in breast cancer. Paradoxically, cyclin D1 is known to enhance radiation sensitivity, a finding that has not yet been therapeutically exploited. Proposed cyclin D1 functions that could be involved in this effect include cyclin-dependent kinase (CDK)-dependent phosphorylation of retinoblastoma gene product (pRb), titration of p21/p27 complexes, and less well-characterized effects on gene expression. In this report, we sought to clarify the functions of cyclin D1 that might contribute to enhanced radiation sensitivity. Breast cancer cells stably overexpressing a cyclin D1 mutant (KE) that cannot interact with its CDK partners to phosphorylate pRb were as radiation sensitive as those expressing wild-type D1. Although cyclin D1 has been proposed to affect radiation sensitivity through interactions with p21, a cyclin D1 mutant defective for p21 interactions also increased radiation sensitivity. Cyclin D1 overexpression is generally confined to hormone receptor-positive breast cancers, wherein standard therapies include both radiation and hormonal therapies. Among several proposed CDK-independent cyclin D1 targets, we have identified heat shock protein B8 (HSPB8) as a target particularly associated with cyclin D1 and ER-positive tumors. We therefore evaluated its potential contribution to radiation sensitivity. Overexpression of HSPB8 markedly increased radiation sensitivity, and HSPB8 small interfering RNA blocked cyclin D1's enhancement of radiation sensitivity. Taken together, our results show that some of cyclin D1's effects on radiation sensitivity are CDK and p21 independent and identify HSPB8 as a candidate CDK-independent cyclin D1 target that can mediate its effects.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
1538-7445
pubmed:author
pubmed:issnType
Electronic
pubmed:day
15
pubmed:volume
67
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
10774-81
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Heat shock protein B8, a cyclin-dependent kinase-independent cyclin D1 target gene, contributes to its effects on radiation sensitivity.
pubmed:affiliation
Oxford Cancer Centre, Department of Radiotherapy, Churchill Hospital, Oxford, United Kingdom.
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural