Epirubicin-[Anti-HER2/ neu] Synthesized with an Epirubicin-(C13- imino)-EMCS Analog: Anti-Neoplastic Activity against Chemotherapeutic-Resistant SKBr-3 Mammary Carcinoma in Combination with Organic Selenium

Cody P Coyne; Toni Jones; Andrzej Sygula; John Bailey; Lesya Pinchuk

doi:10.4236/jct.2011.21004

Epirubicin-[Anti-HER2/ neu] Synthesized with an Epirubicin-(C₁₃- imino)-EMCS Analog: Anti-Neoplastic Activity against Chemotherapeutic-Resistant SKBr-3 Mammary Carcinoma in Combination with Organic Selenium

J Cancer Ther. 2011 Mar;2(1):22-39. doi: 10.4236/jct.2011.21004.

Authors

Cody P Coyne¹, Toni Jones¹, Andrzej Sygula², John Bailey³, Lesya Pinchuk¹

Affiliations

¹ Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, USA.
² Department Organic Chemistry, Mississippi State University, Mississippi State, USA.
³ College of Osteopathic Medicine, William Cary University, Hattiesburg, USA.

Abstract

Purpose: Discover the anti-neoplastic efficacy of epirubicin-(C₁₃-imino)-[anti-HER2/neu] against chemotherapeutic-resistant SKBr-3 mammary carcinoma and delineate the capacity of selenium to enhance it's cytotoxic anti-neoplastic potency.

Methods: In molar excess, EMCH was combined with epirubicin to create a covalent epirubicin-(C₁₃-imino)-EMCH-maleimide intermediate with sulfhydryl-reactive properties. Monoclonal immunoglobulin selective for HER2/neu was then thiolated with 2-iminothiolane at the terminal ε-amine group of lysine residues. The sulfhydryl-reactive epirubicin-(C₁₃-imino)-EMCH intermediate was then combined with thiolated anti-HER2/neu monoclonal immunoglobulin. Western-blot analysis was utilized to characterize the molecular weight profiles while binding of epirubicin-(C₁₃-imino)-[anti-HER2/neu] to membrane receptors was determined by cell-ELISA utilizing populations of SKBr-3 mammary carcinoma that highly over-expresses HER2/neu complexes. Anti-neoplastic potency of epirubicin-(C₁₃-imino)-[anti-HER2/neu] between the epirubicin-equivalent concentrations of 10^-12 M and 10^-7 M was determined by vitality staining analysis with and without the presence of selenium (5 μM).

Results: Epiribucin-(C₁₃-imino)-[anti-HER2/neu] between epirubicin-equivalent concentrations of 10^-8 M to 10^-7 M consistently evoked higher anti-neoplastic potency than "free" non-conjugated epirubicin which corresponded with previous investigations utilizing epirubicin-(C₃-amide)-[anti-HER2/neu] and epirubicin-(C₃-amide)-[anti-EGFR]. Selenium at 5 mM consistently enhanced the cytotoxic anti-neoplastic potency of epirubicin-(C13-imino)-[anti-HER2/neu] at epirubicin equivalent concentrations (10-12 to 10-7 M).

Conclusions: Epirubicin-(C₁₃-imino)-[anti-HER2/neu] is more potent than epirubicin against chemotherapeutic-resistant SKBr-3 mammary carcinoma and selenium enhances epirubicin-(C₁₃-imino)-[anti-HER2/neu] potency. The methodology applied for synthesizing epirubicin-(C₁₃-imino)-[anti-HER2/neu] is relatively time convenient and has low instrumentation requirements.

Keywords: Chemotherapeutic-Resistant Mammary Carcinoma; Epirubicin-(C13-Imino)-[Anti-HER2/neu]; HER2/neu; Selenium; Synthesis.

Grants and funding

T35 OD010432/OD/NIH HHS/United States