PIK3CA exon 20 mutations are associated with poor prognosis in breast cancer patients

OBJECTIVES: The phosphatidylinositol 3-kinase/AKT axis is an important cell-signaling pathway that mediates cell proliferation and survival, two biological processes that regulate malignant cell growth. The phosphatidylinositol 3-kinase CA gene encodes the p110α subunit of the phosphatidylinositol...

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Main Authors: Flavia R. Mangone, Irina G. Bobrovnitchaia, Sibeli Salaorni, Erika Manuli, Maria A. Nagai
Format: Article
Language:English
Published: Elsevier España 2012-11-01
Series:Clinics
Subjects:
Online Access:http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1807-59322012001100011
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author Flavia R. Mangone
Irina G. Bobrovnitchaia
Sibeli Salaorni
Erika Manuli
Maria A. Nagai
author_facet Flavia R. Mangone
Irina G. Bobrovnitchaia
Sibeli Salaorni
Erika Manuli
Maria A. Nagai
author_sort Flavia R. Mangone
collection DOAJ
description OBJECTIVES: The phosphatidylinositol 3-kinase/AKT axis is an important cell-signaling pathway that mediates cell proliferation and survival, two biological processes that regulate malignant cell growth. The phosphatidylinositol 3-kinase CA gene encodes the p110α subunit of the phosphatidylinositol 3-kinase protein. There are phosphatidylinositol 3-kinase CA mutations in several types of human tumors, and they are frequently observed in breast cancer. However, these mutations have not been investigated in Brazilian breast cancer patients. METHODS: PCR-SSCP and direct DNA sequencing were performed to identify phosphatidylinositol 3-kinaseCA exon 9 and exon 20 mutations in 86 patients with sporadic breast cancer. The relationships between PIK3CA mutations and patient clinicopathological characteristics and survival were analyzed. The presence of the TP53 mutation was also examined. RESULTS: Twenty-three (27%) of the 86 primary breast tumors contained PIK3CA mutations. In exons 9 and 20, we identified the hotspot mutations E542K, E545K, and H1047R, and we identified two new missense mutations (I1022V and L1028S) and one nonsense (R992X) mutation. Phosphatidylinositol 3-kinase CA exon 20 mutations were associated with poor overall survival and TP53 gene mutations. CONCLUSIONS: Phosphatidylinositol 3-kinase CA mutations are common in tumors in Brazilian breast cancer patients, and phosphatidylinositol 3-kinase CA and TP53 mutations are not mutually exclusive. Phosphatidylinositol 3-kinase CA exon 20 mutations are associated with poor survival, and they may be useful biomarkers for identifying breast cancer patients with aggressive tumors and for predicting the response to treatment with PI3K pathway inhibitors.
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spelling doaj.art-9800bb5d8e12447798ac4b9a8bb9bdb02022-12-22T02:27:02ZengElsevier EspañaClinics1807-59321980-53222012-11-0167111285129010.6061/clinics/2012(11)11PIK3CA exon 20 mutations are associated with poor prognosis in breast cancer patientsFlavia R. MangoneIrina G. BobrovnitchaiaSibeli SalaorniErika ManuliMaria A. NagaiOBJECTIVES: The phosphatidylinositol 3-kinase/AKT axis is an important cell-signaling pathway that mediates cell proliferation and survival, two biological processes that regulate malignant cell growth. The phosphatidylinositol 3-kinase CA gene encodes the p110α subunit of the phosphatidylinositol 3-kinase protein. There are phosphatidylinositol 3-kinase CA mutations in several types of human tumors, and they are frequently observed in breast cancer. However, these mutations have not been investigated in Brazilian breast cancer patients. METHODS: PCR-SSCP and direct DNA sequencing were performed to identify phosphatidylinositol 3-kinaseCA exon 9 and exon 20 mutations in 86 patients with sporadic breast cancer. The relationships between PIK3CA mutations and patient clinicopathological characteristics and survival were analyzed. The presence of the TP53 mutation was also examined. RESULTS: Twenty-three (27%) of the 86 primary breast tumors contained PIK3CA mutations. In exons 9 and 20, we identified the hotspot mutations E542K, E545K, and H1047R, and we identified two new missense mutations (I1022V and L1028S) and one nonsense (R992X) mutation. Phosphatidylinositol 3-kinase CA exon 20 mutations were associated with poor overall survival and TP53 gene mutations. CONCLUSIONS: Phosphatidylinositol 3-kinase CA mutations are common in tumors in Brazilian breast cancer patients, and phosphatidylinositol 3-kinase CA and TP53 mutations are not mutually exclusive. Phosphatidylinositol 3-kinase CA exon 20 mutations are associated with poor survival, and they may be useful biomarkers for identifying breast cancer patients with aggressive tumors and for predicting the response to treatment with PI3K pathway inhibitors.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1807-59322012001100011Breast NeoplasmPIK3CATP53MutationPrognosis
spellingShingle Flavia R. Mangone
Irina G. Bobrovnitchaia
Sibeli Salaorni
Erika Manuli
Maria A. Nagai
PIK3CA exon 20 mutations are associated with poor prognosis in breast cancer patients
Clinics
Breast Neoplasm
PIK3CA
TP53
Mutation
Prognosis
title PIK3CA exon 20 mutations are associated with poor prognosis in breast cancer patients
title_full PIK3CA exon 20 mutations are associated with poor prognosis in breast cancer patients
title_fullStr PIK3CA exon 20 mutations are associated with poor prognosis in breast cancer patients
title_full_unstemmed PIK3CA exon 20 mutations are associated with poor prognosis in breast cancer patients
title_short PIK3CA exon 20 mutations are associated with poor prognosis in breast cancer patients
title_sort pik3ca exon 20 mutations are associated with poor prognosis in breast cancer patients
topic Breast Neoplasm
PIK3CA
TP53
Mutation
Prognosis
url http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1807-59322012001100011
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