Assessment of ERBB2 and EGFR gene amplification and protein expression in gastric carcinoma by immunohistochemistry and fluorescence in situ hybridization

Gao Cf,Lv Xx,Chen Z,Wang Yk,Meng Nl,Yun T,Zhang Xw,Zhao Wz

doi:10.1186/1755-8166-4-14

Abstract

BackgroundThe goal of this study was to investigate ERBB2(HER2) and EGFR gene amplification and protein expression in gastric cancer. Fluorescence in situ hybridization (FISH) and immunohistochemistry were used to analyze ERBB2 and EGFR gene amplification and protein expression in 69 cases of gastric cancer.ResultsFISH analysis revealed that 20.3% of the cases exhibited ERBB2 gene amplification. Increases in ERBB2 copy number and gene amplification were present in 52.2% of the samples. Expression of the ERBB2 protein was observed in 42.0% of cases. FISH analysis detected EGFR gene amplification in 29.0% of samples. Increases in EGFR copy number and gene amplification occurred in 57.9% of samples, and EGFR protein expression was present in 52.2% of samples. Both ERBB2 and EGFR gene amplification were 3 cases (4.3%), but abnormalities in both ERBB2 and EGFR gene copy number were present 36.2% of samples. ERBB2 and EGFR gene amplification were significantly associated with the depth of tumor invasion (P < 0.05) and lymph node metastasis (P < 0.05), but not with sex, age, or histological type (P > 0.05).ConclusionsOur data indicated that ERBB2 and EGFR genetic abnormalities were associated with the prognosis of gastric cancer. Clinical assessment of ERBB2 and EGFR amplification may represent an important factor for the development of personalized treatment programs for gastic cancer.

Highlights

Overexpression of the human epidermal growth factor receptor 2 (ERBB2(HER2)), known as C-erbB-2, can lead to the activation of cellular signal transduction systems, resulting in the cellular transformation and cell proliferation events associated with cancer [1]
Of the remaining 55 cases without ERBB2 gene amplification, the copy number was increased in 22 cases
ERBB2 copy number increases or gene amplification were observed in a total of 52.2% (36/69) of the samples

Summary

Introduction

Overexpression of the human epidermal growth factor receptor 2 (ERBB2(HER2)), known as C-erbB-2, can lead to the activation of cellular signal transduction systems, resulting in the cellular transformation and cell proliferation events associated with cancer [1]. ERBB2 is very similar in structure to the epidermal growth factor receptor (EGFR), with approximately 95% homology between the 260 amino acid intracellular region (aa 727986), which contains the EGFR tyrosine kinase domain, and the corresponding domain in EGFR. Both ERBB2 and EGFR are membrane-associated tyrosine kinases and contain three functional domains: the extracellular ligand binding domain (aa 1-632), a lipophilic and EGFR expression status and clinicopathological variables in gastric cancer. The goal of this study was to investigate ERBB2(HER2) and EGFR gene amplification and protein expression in gastric cancer. Fluorescence in situ hybridization (FISH) and immunohistochemistry were used to analyze ERBB2 and EGFR gene amplification and protein expression in 69 cases of gastric cancer

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