EGFR and EGFRvIII expression in primary breast cancer and cell lines.
EGFRvIII is a constitutively activated truncated variant of the epidermal growth factor receptor (EGFR) which has been shown to increase tumorgenicity. There are conflicting reports on the extent of EGFRvIII expression in tissues which may in part stem from the use of different assay methodologies. We investigated the expression of both EGFRvIII and wild-type EGFR (EGFRwt) in cell lines and primary breast cancers. First, we used a RT-PCR assay that can simultaneously measure EGFRwt and EGFRvIII mRNA to screen 55 tumor cell lines. We show that except for EGFRvIII transfected cells, only EGFRwt was detected. We then validated a real-time PCR assay and used this to screen 170 formalin fixed paraffin-embedded primary breast cancers for evidence of EGFRwt and EGFRvIII expression. No samples were positive for EGFRvIII expression except for control transfectants and glioblastomas. In contrast, EGFRwt was expressed at varying levels in the majority of samples tested. We conclude that the expression of EGFRvIII is extremely rare in breast cancer and therefore it does not contribute to the malignant phenotype.
Rae
James M
JM
Department of Internal Medicine, Division of Hematology Oncology, University of Michigan Medical Center, Ann Arbor, MI 48109-0612, USA. jimmyrae@umich.edu
Scheys
Joshua O
JO
Clark
Kim M
KM
Chadwick
Robert B
RB
Kiefer
Michael C
MC
Lippman
Marc E
ME
D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology*; D018270:Carcinoma, Ductal, Breast / Q000235:genetics* / Q000473:pathology*; D066246:ErbB Receptors / Q000096:biosynthesis*; D005260:Female; D006801:Humans; D010641:Phenotype; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000096:biosynthesis; D014407:Tumor Cells, Cultured
D012333:RNA, Messenger; C410723:epidermal growth factor receptor VIII; D066246:ErbB Receptors