Linked Life Data

17431403

Source:http://linkedlifedata.com/resource/pubmed/id/17431403

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2007-5-16
pubmed:abstractText
Expression of the PTEN tumor suppressor gene is abnormal in many human cancers. Loss of PTEN expression leads to the activation of downstream signaling pathways that have been associated with resistance to radiation. In non-small cell lung carcinoma (NSCLC), suppressed expression of PTEN is frequently due to methylation of its promoter region. In this study, we tested whether gene transfer of wild-type PTEN into an NSCLC cell line with a known methylated PTEN promoter, H1299, would increase its sensitivity to ionizing radiation. Pretreating H1299 cells with an adenoviral-mediated PTEN (Ad-PTEN)-expressing vector sensitized H1299 cells to radiation. To determine the mechanism responsible for radiosensitization, we first examined radiation-induced apoptosis, which was enhanced but did not correlate with radiosensitizing effect of Ad-PTEN. Therefore, we next examined the ability of Ad-PTEN to modulate the repair of radiation-induced DNA double-strand breaks (DSBs) using the detection of repair foci positive for gamma-H2AX, a protein that becomes evident at the sites of each DSB and that can be visualized by immunofluorescent staining. Compared with controls, the repair of radiation-induced DSBs was retarded in H1299 cells pretreated with Ad-PTEN, consistent with the radiosensitizing effect of the vector. We conclude that signal transduction pathways residing primarily in the cytoplasm may intersect with DNA damage and repair pathways in the nucleus to modulate cellular responses to radiation. Elucidating the mechanisms responsible for this intersection may lead to novel strategies for improving therapy for cancers with defective PTEN.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0929-1903
pubmed:author
pubmed:issnType
Print
pubmed:volume
14
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
543-9
pubmed:dateRevised
2007-12-3
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Adenoviral-mediated PTEN expression radiosensitizes non-small cell lung cancer cells by suppressing DNA repair capacity.
pubmed:affiliation
Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural