Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
29
pubmed:dateCreated
2008-7-3
pubmed:abstractText
Ectopic expression of mutant forms of phosphatase and tensin homologue deleted on chromosome 10 (PTEN) lacking lipid (G129E) or lipid and protein (C124S) phosphatase activity decreased sensitivity of MCF-7 breast cancer cells, which have wild-type PTEN, to doxorubicin and increased sensitivity to the mammalian target of rapamycin (mTOR) inhibitor rapamycin. Cells transfected with a mutant PTEN gene lacking both lipid and protein phosphatase activities were more resistant to doxorubicin than cells transfected with the PTEN mutant lacking lipid phosphatase activity indicating that the protein phosphatase activity of PTEN was also important in controlling the sensitivity to doxorubicin, while no difference was observed between the lipid (G129E) and lipid and protein (C124S) phosphatase PTEN mutants in terms of sensitivity to rapamycin. A synergistic inhibitory interaction was observed when doxorubicin was combined with rapamycin in the phosphatase-deficient PTEN-transfected cells. Interference with the lipid phosphatase activity of PTEN was sufficient to activate Akt/mTOR/p70S6K signaling. These studies indicate that disruption of the normal activity of the PTEN phosphatase can have dramatic effects on the therapeutic sensitivity of breast cancer cells. Mutations in the key residues which control PTEN lipid and protein phosphatase may act as dominant-negative mutants to suppress endogenous PTEN and alter the sensitivity of breast cancer patients to chemo- and targeted therapies.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
1476-5594
pubmed:author
pubmed:issnType
Electronic
pubmed:day
3
pubmed:volume
27
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4086-95
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed-meshheading:18332865-Amino Acid Substitution, pubmed-meshheading:18332865-Antibiotics, Antineoplastic, pubmed-meshheading:18332865-Breast Neoplasms, pubmed-meshheading:18332865-Cell Line, Tumor, pubmed-meshheading:18332865-Doxorubicin, pubmed-meshheading:18332865-Drug Resistance, Neoplasm, pubmed-meshheading:18332865-Drug Synergism, pubmed-meshheading:18332865-Female, pubmed-meshheading:18332865-Gene Expression, pubmed-meshheading:18332865-Humans, pubmed-meshheading:18332865-Mutation, Missense, pubmed-meshheading:18332865-PTEN Phosphohydrolase, pubmed-meshheading:18332865-Protein Kinases, pubmed-meshheading:18332865-Proto-Oncogene Proteins c-akt, pubmed-meshheading:18332865-Ribosomal Protein S6 Kinases, 70-kDa, pubmed-meshheading:18332865-Signal Transduction, pubmed-meshheading:18332865-Sirolimus, pubmed-meshheading:18332865-TOR Serine-Threonine Kinases, pubmed-meshheading:18332865-Transfection
pubmed:year
2008
pubmed:articleTitle
Suppression of PTEN function increases breast cancer chemotherapeutic drug resistance while conferring sensitivity to mTOR inhibitors.
pubmed:affiliation
Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, NC 27858, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural