Analysis of HER2 gene amplification using Differential PCR in breast cancer patients of Isfahan Province

Abstract

Background: Amplification of HER2 is seen in 20-30% of breast cancer cases. Measurement of HER2 gene amplification appears to be of vital importance in planning the treatment schedule for patients with breast carcinoma. The aim of our study was to evaluate HER2 amplification status in malignant and benign breast tumors by differential PCR (dPCR). Materials and Methods:The genomic DNA was extracted using the phenol/chloroform extraction procedure from 76 different breast tissues. Differential PCR was performed using the DNA samples isolated from fresh and paraffin-embedded breast cancer tissues. The relative copy number ratio of target gene (HER2) to control gene (INF-γ) was measured. dPCR products were then separated by electrophoresis using 2% agarose gel. The intensity of HER2 and INFγ bands were determined for each sample by ImageJ software. Results: According to the ratio between the band intensity of HER2 to INFγ in tumour and also normal samples, 7% and 26% rates of HER2 amplification were observed in benign and malignant samples respectively. The ratio showed a 2-5 fold increase in HER2 gene copy number for tissues with HER2 amplification; whereas, a one-fold increase was found in other samples. Conclusion: Differential PCR provides a relatively rapid and inexpensive technique to assess the HER2 gene amplification, especially alongside immunohistochemistry as a routine assessing method.

ErbB4 3′-UTR Variant (c.*3622A>G) is Associated with ER/PR Negativity and Advanced Breast Cancer

“…Along with important genes such as BRCA1/BRCA2/ EpCAM/c-Myc [6], members of the EGF receptor (EGFR) subfamily of receptor tyrosine kinases, ErbB1 (EGFR, HER1), ErbB2 (HER2), ErbB3 (HER3), and ErbB4 (HER4) play a critical role in the pathogenesis and tumorigenic processes of breast cancer [7][8][9][10]. ErbB4 expression is typically correlated with estrogen receptor (ER) and progesterone receptor (PR) positivity, HER2 receptor-negativity, well-differentiated phenotype (lower tumor grade), smaller tumor size, lower risk for relapse, longer overall survival, and also favorable outcome [8,[11][12][13][14][15].…”