To address this problem, we generated oligonucleotide (< 100-400 base pair) combinatorial libraries from either the epidermal growth factor (EGF) ORF that encodes the > 1200 amino acid EGF precursor protein or the orphan ECRG4 ORF, that encodes a 148 amino acid Esophageal Cancer Related Gene 4 (ECRG4), a putative cytokine precursor protein of up to eight ligands.
In the stratified analysis by cancer types, the G allele and GG genotype of EGF +61A>G polymorphism showed displayed significant correlations with increased risk of esophageal cancer.
The pilot study suggests that EGF +61AG and +61GG genotypes may predict clinical outcome in esophageal cancer patients treated with radiotherapy with or without chemotherapy.
IGFBP-3 secreted by cancer cells was capable of binding to insulin-like growth factor I. Functionally, epidermal growth factor appeared to regulate IGFBP-3 expression in esophageal cancer cell lines.