Guoyao Zang, Ashley Thomas, Zhongyuan Liu, Di Chen2, Hong Ling, Liangyi Zhou, Fuchun Zhang, Leo Siu and Xiufen Zheng
Development of treatment resistance and lack of specificity are common problems in cancer chemotherapy, resulting in diverse and negative side effects. Emerging studies have shown that certain anti-microbial peptides (AMPs) have a destructive effect on cancer cells but no effect on normal eukaryotic cells. We isolated a cationic antimicrobial peptide--Cecropin B from silk worms infected with staphylococcus aureus and investigated its effects on breast cancer growth in vitro and in vivo. Treatment with Cecropin B induced cell death of murine breast cancer cells but not of normal nonmalignant cells. Cecropin B inhibited cancer cell proliferation as compared with control. Cecropin B treatment increased gene expression of Caspase3, Fas and high mobility group box 1 (HMGB 1). Administration of Cecropin B in vivo reduced tumor growth. In conclusion, Cecropin B possesses specific killing ability against tumor cells. There is the potential of development of anti-microbial peptides as anti-cancer drugs.
