Amplification of a Novel v- <i>erb</i> B-Related Gene in a Human Mammary Carcinoma

TLDR

The EGF receptor gene shares substantial homology with the avian erythroblastosis virus oncogene. In a human mammary carcinoma, a v‑erbB–related DNA segment was amplified, cloned, and sequenced, revealing two putative exons and an amino‑acid sequence distinct from the EGF receptor. The amplified segment encodes a 5‑kb transcript, establishing a novel tyrosine‑kinase proto‑oncogene in breast cancer.

Abstract

The cellular gene encoding the receptor for epidermal growth factor (EGF) has considerable homology to the oncogene of avian erythroblastosis virus. In a human mammary carcinoma, a DNA sequence was identified that is related to v- erb B but amplified in a manner that appeared to distinguish it from the gene for the EGF receptor. Molecular cloning of this DNA segment and nucleotide sequence analysis revealed the presence of two putative exons in a DNA segment whose predicted amino acid sequence was closely related to, but different from, the corresponding sequence of the erb B/EGF receptor. Moreover, this DNA segment identified a 5-kilobase transcript distinct from the transcripts of the EGF receptor gene. Thus, a new member of the tyrosine kinase proto-oncogene family has been identified on the basis of its amplification in a human mammary carcinoma.