Minimal HER۱ and HER۲ expressions in CHO and HEK-۲۹۳ cells cause them appropriate negative cells for HERs-related studies

Background: Understanding of cellular and molecular mechanisms involved in cell/tumor growth and progression has led to molecular-targeted therapy. HER۱ and HER۲ are two main oncogenic components of HER-receptor family considered as targets for cancer research and therapy. Reliable results of HER- related research and targeted therapies dependent upon cell line with known HER expression status. But there are no published studies focusing on determination of HER۱ and HER۲ receptors expression in CHO and HEK-۲۹۳ cell lines. Materials and Methods: Absolute expressions of HER۱ and HER۲ in CHO, HEK-۲۹۳, MDA-MB-۴۶۸ and SKBR۳ cells were evaluated using quantitative real-time PCR. Absolute expression quantification was carried out by serial dilution plasmids harboring HER۱ and HER۲ to extrapolate standard curve. Results: Real-time PCR amplification was successfully optimized by HER۱ and HER۲ plasmids with high efficiency and their copy numbers were calculated. The results showed that HER۱ was not expressed in CHO and HEK-۲۹۳ cells but these cells express HER۲ up to ۹.۴ × ۱۰۲ and ۱.۱ × ۱۰۵ copy/µg, respectively. MDA-MB-۴۶۸ and SKBR۳ cells express HER۱ up to ۸.۴ × ۱۰۵ and ۹.۷ × ۱۰۴, respectively. In addition, the expression of HER۲ is higher on the surface of SKBR۳ cell (۶.۵ × ۱۰۶ copy/µg). Conclusion: Our study provides a proven insight to HER۱ and HER۲ expression status in CHO, HEK-۲۹۳, MDA-MB-۴۶۸ and SKBR۳ cells. Heterologous expression of HER۱ and HER۲ in cell lines is the first step in structural and functional studies. Since HER۱ is not expressed in CHO and HEK-۲۹۳ endogenously, these cells are ideal for HER receptor related studies.

Keywords:

Real-time PCR , HER۱ , HER۲ , Expression , Targeted-therapy , CHO and HEK-۲۹۳