BACKGROUND AND PURPOSE: Over the past decades, targeted therapies and immunotherapy have vastly improved survival and reduced the morbidity of patients with BRAF-mutated melanoma. However, drug resistance and relapse hinder overall success. Therefore, there is an urgent need for novel compounds with therapeutic efficacy against BRAF- melanoma. This prompted us to investigate the antiproliferative profile of a tachykinin-peptide from the Octopus kaurna, Octpep-1 in melanoma. EXPERIMENTAL APPROACH: We evaluated the cytotoxicity of Octpep-1 by MTT assay. Mechanistic insights on viability and cellular damage caused by Octpep-1 were gained via flow cytometry and bioenergetics. Structural and pharmacological characterization was conducted by molecular modelling, molecular biology, CRISPR/Cas9 technology, high-throughput mRNA and calcium flux analysis. In-vivo efficacy was validated in two independent xerograph animal models (mice and zebrafish). KEY RESULTS: -mutated cells with minimal effects on fibroblasts. In melanoma-treated cells, Octpep-1 increased ROS with unaltered mitochondrial membrane potential and promoted non-mitochondrial and mitochondrial respiration with inefficient ATP coupling. Despite similarities with tachykinin peptides, knock-out or pharmacological blockade of tachykinin receptors suggested that Octpep-1 acts via a tachykinin-independent mechanism. Molecular modelling revealed that the cytotoxicity of Octpep-1 depends upon the a-helix and polyproline conformation in the C-terminal region of the peptide. Indeed, a truncated form of the C-terminal end of Octpep-1 displayed enhanced potency and efficacy against melanoma. Octpep-1 reduced the progression of tumors in xenograft melanoma mice and zebrafish, confirming its therapeutic potential in human BRAF-mutated melanoma. CONCLUSION AND IMPLICATIONS: We unravel the intrinsic anti-tumoral properties of a tachykinin peptide, possessing a pharmacology independent of tachykinin-receptors. This peptide mediates the selective cytotoxicity in BRAF-mutated melanoma in-vitro and prevents tumor progression in-vivo, providing the foundation for a potential therapy against melanoma.
| Authors | Moral-Sanz, Javier; Fernandez-Rojo, Manuel A; Colmenarejo, Gonzalo; Kurdyukov, Sergey; Brust, Andreas; Ragnarsson, Lotten; Andersson, Åsa; Vila, Sabela F; Cabezas-Sainz, Pablo; Wilhelm, Patrick; Vela-Sebastian, Ana; Fernández-Carrasco, Isabel; Chin, Yanni K Y; López-Mancheño, Yaiza; Smallwood, Taylor B; Clark, Richard J; Fry, Bryan G; King, Glenn F; Ramm, Grant A; Alewood, Paul F; Lewis, Richard J; Mulvenna, Jason P; Boyle, Glen M; Sanchez, Laura E; Neely, G Gregory; Miles, John J; Ikonomopoulou, Maria P |
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| Journal | BRITISH JOURNAL OF PHARMACOLOGY |
| Pages | 4878-4896 |
| Volume | 179 |
| Date | 1/01/2022 |
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| URL | http://www.ncbi.nlm.nih.gov/pubmed/?term=10.1111/bph.15923 |