Detection of kinase amplifications in gastric adenocarcinomas

Aim: To determine the incidences of copy number aberrations of receptor kinases and their relations in Turkish patients with gastric adenocarcinoma. Materials and methods: The prevalence of genomic copy number aberrations of epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2)/topoisomerase IIa (TOP2A), centrosome-associated kinase aurora A (AURK A), centrosome-associated kinase aurora B (AURK B), and mesenchymal-epithelial transition factor (MET) genes and polysomies of related chromosomes were analyzed by fluorescent in situ hybridization (FISH) in tumor samples from 35 patients with gastric cancer. Results: There were 28.6%, 65.7%, 20.0%, 17.1%, 60.0%, and 45.7% cases considered FISH-positive for EGFR, MET, HER2, TOP2A, AURK A, and AURK B genes, respectively. Statistically significant associations were determined in detection of amplifications of 1) EGFR gene with chromosome 7 polysomy, 2) MET gene in nonpolysomic chromosome 7 nuclei, 3) HER2/TOP2A genes in nonpolysomic chromosome 17 nuclei, 4) coamplification of HER2/TOP2A in poorly differentiated carcinomas, and 5) AURK A gene in nonpolysomic chromosome 20 nuclei. Most of the aberrations were predominantly seen in poorly differentiated tumors, but a high rate of the amplified MET gene was also detected in moderately differentiated carcinomas. Conclusion: Chromosome 7 polysomy may be responsible for EGFR gene amplifications, and we concluded that MET and AURK A genes amplifications were commonly seen aberrations in gastric adenocarcinomas and may offer information about disease progression and administration of individualized treatment for gastric cancer patients.