TY - JOUR A1 - Wußmann, Maximiliane A1 - Groeber-Becker, Florian Kai A1 - Riedl, Sabrina A1 - Alihodzic, Dina A1 - Padaric, Daniel A1 - Gerlitz, Lisa A1 - Stallinger, Alexander A1 - Liegl-Atzwanger, Bernadette A1 - Zweytick, Dagmar A1 - Rinner, Beate T1 - In model, in vitro and in vivo killing efficacy of antitumor peptide RDP22 on MUG-Mel2, a patient derived cell line of an aggressive melanoma metastasis JF - Biomedicines N2 - The host defense derived peptide was assessed in different model systems with increasing complexity employing the highly aggressive NRAS mutated melanoma metastases cell line MUG-Mel2. Amongst others, fluorescence microscopy and spectroscopy, as well as cell death studies were applied for liposomal, 2D and 3D in vitro models including tumor spheroids without or within skin models and in vivo mouse xenografts. Summarized, MUG-Mel2 cells were shown to significantly expose the negatively charged lipid phosphatidylserine on their plasma membranes, showing they are successfully targeted by RDP22. The peptide was able to induce cell death in MUG-Mel2 2D and 3D cultures, where it was able to kill tumor cells even inside the core of tumor spheroids or inside a melanoma organotypic model. In vitro studies indicated cell death by apoptosis upon peptide treatment with an LC\(_{50}\) of 8.5 µM and seven-fold specificity for the melanoma cell line MUG-Mel2 over normal dermal fibroblasts. In vivo studies in mice xenografts revealed effective tumor regression upon intratumoral peptide injection, indicated by the strong clearance of pigmented tumor cells and tremendous reduction in tumor size and proliferation, which was determined histologically. The peptide RDP22 has clearly shown high potential against the melanoma cell line MUG-Mel2 in vitro and in vivo. KW - melanoma metastases KW - NRAS mutation KW - antitumor peptide KW - tumor model systems KW - phosphatidylserine Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-297525 SN - 2227-9059 VL - 10 IS - 11 ER -