TY - JOUR
T1 - Phosphatidylinositol-3-kinase and AKT1 mutations occur early in breast carcinoma
AU - Dunlap, Jennifer
AU - Le, Claudia
AU - Shukla, Arielle
AU - Patterson, Janice
AU - Presnell, Ajia
AU - Heinrich, Michael C.
AU - Corless, Christopher L.
AU - Troxell, Megan L.
N1 - Funding Information:
Acknowledgments The authors wish to acknowledge expert technical assistance of Carolyn Gendron, Rebecca Lewis, Judith Levine, Carol Beadling, and Andrea Warrick. Dr. Terry Morgan provided assistance with the statistical calculations. This work was supported in part by a VA Merit Review Grant from the Department of Veterans Affairs (MCH) and by a grant from the OHSU Medical Research Foundation.
PY - 2010/4
Y1 - 2010/4
N2 - Mutationally activated protein kinases are appealing therapeutic targets in breast carcinoma. Mutations in phosphatidylinositol-3-kinase (P13KCA) have been described in 8 - 40% of invasive breast carcinomas, and AKT1 mutations have been characterized in 1 - 8% of breast carcinomas. However, there is little data on these mutations in breast precursor lesions. To further delineate the molecular evolution of breast tumorigenesis, samples of invasive breast carcinoma with an accompanying in situ component were macro dissected from formalin-fixed paraffin embedded tissue and screened for mutations in PIK3CA exons 7, 9, 20, and AKT1 exon 2. Laser capture micro dissection (LCM) was performed on mutationpositive carcinomas to directly compare the genotypes of separated invasive and in situ tumor cells. Among 81 cases of invasive carcinoma, there were eight mutations in PIK3CA exon 20 (7 H1047R, 1 H1047L) and four mutations in exon 9 (2 E545K, 1 E542K, 1 E545G), totaling 12/81 (14.8%). In 11 cases examined, paired LCM in situ tumor showed the identical P1K3CA mutation in invasive and in situ carcinoma. Likewise, 3 of 78 (3.8%) invasive carcinomas showed an AKT1 E17K mutation, and this mutation was identified in matching in situ carcinoma in both informative cases. Mutational status did not correlate with clinical parameters including hormone receptor status, grade, and lymph node status. The complete concordance of PIK3CA and AKT1 mutations in matched samples of invasive and in situ tumor indicates that these mutations occur early in breast cancer development and has implications with regard to therapeutics targeted to the PI3 kinase pathway.
AB - Mutationally activated protein kinases are appealing therapeutic targets in breast carcinoma. Mutations in phosphatidylinositol-3-kinase (P13KCA) have been described in 8 - 40% of invasive breast carcinomas, and AKT1 mutations have been characterized in 1 - 8% of breast carcinomas. However, there is little data on these mutations in breast precursor lesions. To further delineate the molecular evolution of breast tumorigenesis, samples of invasive breast carcinoma with an accompanying in situ component were macro dissected from formalin-fixed paraffin embedded tissue and screened for mutations in PIK3CA exons 7, 9, 20, and AKT1 exon 2. Laser capture micro dissection (LCM) was performed on mutationpositive carcinomas to directly compare the genotypes of separated invasive and in situ tumor cells. Among 81 cases of invasive carcinoma, there were eight mutations in PIK3CA exon 20 (7 H1047R, 1 H1047L) and four mutations in exon 9 (2 E545K, 1 E542K, 1 E545G), totaling 12/81 (14.8%). In 11 cases examined, paired LCM in situ tumor showed the identical P1K3CA mutation in invasive and in situ carcinoma. Likewise, 3 of 78 (3.8%) invasive carcinomas showed an AKT1 E17K mutation, and this mutation was identified in matching in situ carcinoma in both informative cases. Mutational status did not correlate with clinical parameters including hormone receptor status, grade, and lymph node status. The complete concordance of PIK3CA and AKT1 mutations in matched samples of invasive and in situ tumor indicates that these mutations occur early in breast cancer development and has implications with regard to therapeutics targeted to the PI3 kinase pathway.
KW - AKT1
KW - Breast carcinoma
KW - Carcinoma in situ
KW - Laser capture microdissection
KW - Phosphatidylinositol-3-kinase (pik3ca)
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U2 - 10.1007/s10549-009-0406-1
DO - 10.1007/s10549-009-0406-1
M3 - Article
C2 - 19418217
AN - SCOPUS:77950691967
SN - 0167-6806
VL - 120
SP - 409
EP - 418
JO - Breast Cancer Research and Treatment
JF - Breast Cancer Research and Treatment
IS - 2
ER -