Antimicrobial and antitumor properties of anuran peptide temporin-SHf induce apoptosis in A549 lung cancer cells.

Temporin-SHf is a linear, ultra-short, hydrophobic, α-helix, and phe-rich cationic antimicrobial peptide. The antitumor activities and mechanism of temporin-SHf-induced cancer cell death are unknown. The temporin-SHf was synthesized by solid-phase Fmoc chemistry and antimicrobial and antitumor activities were investigated. Temporin-SHf was microbiocidal, non-hemolytic, and cytotoxic to human cancer cells but not to non-tumorigenic cells. It affected the cancer cells' lysosomal integrity and caused cell membrane damage. The temporin-SHf inhibited A549 cancer cell proliferation and migration. It is anti-angiogenic and causes cancer cell death through apoptosis. The molecular mechanism of action of temporin-SHf confirmed that it kills cancer cells by triggering caspase-dependent apoptosis through an intrinsic mitochondrial pathway. Owing to its short length and broad spectrum of antitumor activity, temporin-SHf is a promising candidate for developing a new class of anticancer drugs.

Antitumor activity of Tigerinin-1: Necroptosis mediates toxicity in A549 cells.

BACKGROUND: Tigerinins are antimicrobial peptides (AMPs) derived from the skin secretions of the Indian bullfrog Hoplobatrachus tigerinus. METHODS: Tigerinin-1 (FCTMIPIPRCY-Am) peptide was synthesized by solid-phase Fmoc chemistry and investigated its antitumor activities. RESULTS: Tigerinin-1 was cytotoxic to human cancer cells. It causes necrosis by damaging the cell membrane and loss of lysosome integrity. Tigerinin-1triggers the expression of necroptosis pathway proteins. It generates reactive oxygen species (ROS) and induces oxidative stress-mediated genotoxicity. Tigerinin-1 inhibits cancer cell proliferation, reduces neovascularization, and down-regulates the vascular endothelial growth factor (VEGF), vascular endothelial growth factor receptor 2 (VEGFR2), and fibroblast growth factor (FGF) genes. CONCLUSIONS: Tigerinin-1 exhibited its potent antitumor properties in this study. GENERAL SIGNIFICANCE: Tigerinin-1 can be beneficial for developing novel therapeutics for cancer.