title: Analysis of epidermal growth factor receptor mRNA expression by polymerase chain reaction assay in 94 human breast adenocarcinoma tumors.
abstract: It is well known that breast cancer cells can synthesize and secrete various growth factors that are able to stimulate tumor growth through autocrine and/or paracrine mechanisms. EGF is one of these growth factors involved in normal breast epithelial development and tumor proliferation. EGF and TGF alpha (EGF-like peptide) are produced in variable amounts and both bind to the EGF receptor (EGF-R). Previous investigation in the laboratory measuring free and occupied EGF-R sites by differential ligand binding assays had demonstrated that non-occupied and total binding sites were present in 54 and 90% of 216 breast tumor biopsies respectively. EGF-R appeared to be totally masked by endogenous ligand in 40 and 21% of estrogen receptor positive and negative tumors respectively. The aim of the present study was to check by a molecular method the expression of the EGF-R gene. The PCR method was applied to 94 tumor samples of the previous series. Total RNA was treated with 0.5 units of Rnase-free Dnase/mg of RNA to remove any contaminating DNA. We simultaneously reverse transcribed and amplified another transcript (beta-actin) as an internal standard. Both signals were present in 88 of the 94 samples while the presence of EGF-R was detected in 74 of them when assessed by radioligand assay. The findings indicate that 93% of the tumors analysed in this series expressed EGF-R mRNA, in agreement with our previous data on occupied EGF-R sites, i.e. two-fold more than by using the standard binding assay. No significant correlation was observed between the expression of the EGF-R gene and the estrogen receptor content.
authors.affiliation: Centre Léon Bérard, Lyon, France.
authors.forename: N S
authors.initials: NS
authors.lastname: Falette
authors.forename: N
authors.initials: N
authors.lastname: Artagaveytia
authors.forename: M C
authors.initials: MC
authors.lastname: Rostan
authors.forename: E
authors.initials: E
authors.lastname: Garin
authors.forename: J Y
authors.initials: JY
authors.lastname: Bobin
authors.forename: S
authors.initials: S
authors.lastname: Saez
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism* / Q000473:pathology; D001483:Base Sequence; D001706:Biopsy; D015152:Blotting, Northern; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D017931:DNA Primers; D004587:Electrophoresis, Agar Gel; D066246:ErbB Receptors / Q000032:analysis / Q000096:biosynthesis*; D015870:Gene Expression; D006801:Humans; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction / Q000379:methods*; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis*; D011869:Radioligand Assay
chemical_list: D017931:DNA Primers; D012333:RNA, Messenger; D066246:ErbB Receptors