Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
37
pubmed:dateCreated
2010-9-16
pubmed:abstractText
Hyperactivation of phosphatidylinositol-3 kinase (PI3K) can occur as a result of somatic mutations in PIK3CA, the gene encoding the p110? subunit of PI3K. The HER2 oncogene is amplified in 25% of all breast cancers and some of these tumors also harbor PIK3CA mutations. We examined mechanisms by which mutant PI3K can enhance transformation and confer resistance to HER2-directed therapies. We introduced the PI3K mutations E545K and H1047R in MCF10A human mammary epithelial cells that also overexpress HER2. Both mutants conferred a gain of function to MCF10A/HER2 cells. Expression of H1047R PI3K, but not E545K PI3K, markedly upregulated the HER3/HER4 ligand heregulin (HRG). HRG siRNA inhibited growth of H1047R but not E545K-expressing cells and synergized with the HER2 inhibitors trastuzumab and lapatinib. The PI3K inhibitor BEZ235 markedly inhibited HRG and pAKT levels and, in combination with lapatinib, completely inhibited growth of cells expressing H1047R PI3K. These observations suggest that PI3K mutants enhance HER2-mediated transformation by amplifying the ligand-induced signaling output of the ErbB network. This also counteracts the full effect of therapeutic inhibitors of HER2. These data also suggest that mammary tumors that contain both HER2 gene amplification and PIK3CA mutations should be treated with a combination of HER2 and PI3K inhibitors.
pubmed:grant
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-11248153, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-11252954, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-11533657, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-12040186, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-12094235, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-12124352, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-12569369, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-12853564, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-15016963, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-15044465, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-15324695, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-15520168, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-15647370, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-15805248, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-15950905, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-16322248, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-16432179, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-16449998, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-16452222, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-16843263, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-16847462, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-17371237, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-17376864, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-17463250, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-17611497, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-17626872, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-17626883, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-17699871, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-17877460, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-17936563, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-18079394, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-18268322, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-18568074, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-18606717, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-18625725, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-18632642, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-18676830, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-18679714, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-18794884, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-18794885, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-18803986, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-18829560, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-19010894, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-19411071, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-19573809, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-7657393, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581867-9072974
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
1476-5594
pubmed:author
pubmed:issnType
Electronic
pubmed:day
16
pubmed:volume
29
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5193-203
pubmed:dateRevised
2011-7-25
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
H1047R phosphatidylinositol 3-kinase mutant enhances HER2-mediated transformation by heregulin production and activation of HER3.
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