{
  "abstract": "Background/Objectives: The rise in cancer cases is a major global public health problem. Treating the disease and maintaining health generate high economic and social costs. In recent years, treatment resistance has become a challenge, reinforcing the need for new anticancer agents. In this context, anticancer peptides (ACPs) stand out for their selective interaction with cancer cell membranes. This study aimed to evaluate the activity of the RQ18 peptide against cancer cells. Methods: The cytotoxicity of RQ18 was determined by the MTT assay in murine melanoma (B16F10-Nex2), human melanoma (Sk-mel-28 and A375), breast cancer (MCF-7), cervical cancer (HeLa), murine macrophage (RAW 264.7), and human fibroblast (FN1). Caspase-3/7 activity was further evaluated in B16F10-Nex2, Sk-mel-28, and A375 melanoma cells to investigate the involvement of apoptotic pathways. In addition, intracellular oxidative stress was assessed using the DCFH-DA probe in these three melanoma cell lines. In B16F10-Nex2 cells, cellular morphological changes were examined by microscopy, while apoptosis-associated events were characterized using the markers MitoTracker Deep Red, and NucBlue, complemented by flow cytometry analyses. In addition, molecular dynamics simulations were employed to investigate its interactions with lipid membranes. Results: The peptide exhibited anticancer activity, with IC₅₀ values of 4.4, 11.58 and 59.99 µM·mL⁻¹, against cells B16F10-Nex2, Sk-mel-28 and A375, respectively. Compared with non-cancerous cells, RQ18 preferentially affected cancer cells, especially B16F10-Nex2. In contrast, the peptide was nontoxic to healthy cells, thus indicating selectivity for cancer cells. Morphological analysis revealed alterations compatible with apoptosis, including cell rounding and chromatin condensation. RQ18 increased caspase-3/7 activity in B16F10-Nex2, Sk-mel-28, and A375 cells and induced intracellular oxidative stress, as indicated by increased DCFH-DA fluorescence. Flow cytometry data confirmed the induction of apoptotic cell death in B16F10-Nex2 cells. Caspase activation, detected by a caspase-3/7 assay in three melanoma cell lines, together with flow cytometry data, supported the involvement of apoptotic cell death. Molecular dynamics simulations suggest that the peptide interacts stably with cancer cell-like membranes and retains an α-helical conformation during membrane association. Conclusions: In summary, the RQ18 peptide demonstrates preferential anticancer activity, particularly against melanoma cells, supporting further investigation of its therapeutic potential.",
  "abstract_shown": true,
  "affiliations": [
    "Programa de Pós-Graduação em Bioquímica e Biologia Molecular, Instituto de Biociências (INBIO), Universidade Federal de Mato Grosso do Sul, Campo Grande 79070-900, MS, Brazil.",
    "Laboratório de Purificação de Proteínas e suas Funções Biológicas (LPPFB), Faculdade de Ciências Farmacêuticas, Alimentos e Nutrição (FACFAN), Universidade Federal de Mato Grosso do Sul, Campo Grande 79070-900, MS, Brazil.",
    "S-Inova Biotech, Programa de Pós-Graduação em Biotecnologia, Universidade Católica Dom Bosco, Campo Grande 79117-900, MS, Brazil.",
    "Centro de Estudos em Células Tronco, Terapia Celular e Genética Toxicológica (CeTroGen), Faculdade de Medicina (FAMED), Universidade Federal de Mato Grosso do Sul, Campo Grande 79070-900, MS, Brazil.",
    "Centro de Análises Proteômicas e Bioquímicas, Programa de Pós-Graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, Brasília 71966-700, DF, Brazil.",
    "Programa de Pós-Graduação em Ciências Ambientais e Sustentabilidade Agropecuária, Universidade Católica Dom Bosco, Campo Grande 79117-900, MS, Brazil."
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 13,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Claudiane Vilharroel Almeida",
      "orcid": "0000-0002-9625-5766"
    },
    {
      "affs": [
        1
      ],
      "name": "Ana Cristina Jacobowski",
      "orcid": "0000-0001-8233-0713"
    },
    {
      "affs": [
        1
      ],
      "name": "Caio Fernando Ramalho de Oliveira",
      "orcid": "0000-0001-9549-4848"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Luís Henrique de Oliveira Almeida",
      "orcid": "0000-0002-8322-1372"
    },
    {
      "affs": [
        1
      ],
      "name": "Camila de Oliveira Gutierrez"
    },
    {
      "affs": [
        1
      ],
      "name": "Tamaeh Monteiro-Alfredo",
      "orcid": "0000-0001-5514-0797"
    },
    {
      "affs": [
        2
      ],
      "name": "Lucas Rodrigues de Lima",
      "orcid": "0000-0001-8351-2551"
    },
    {
      "affs": [
        3
      ],
      "name": "Thais de Andrade Farias Rodrigues",
      "orcid": "0000-0002-1937-0162"
    },
    {
      "affs": [
        3
      ],
      "name": "Rodrigo Juliano Oliveira",
      "orcid": "0000-0003-3514-3346"
    },
    {
      "affs": [
        2,
        4
      ],
      "name": "Octávio Luiz Franco",
      "orcid": "0000-0001-9546-0525"
    },
    {
      "affs": [
        0,
        2,
        5
      ],
      "name": "Marlon Henrique Cardoso",
      "orcid": "0000-0001-6676-5362"
    },
    {
      "affs": [
        1
      ],
      "name": "Ana Paula de Araújo Boleti"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Maria Lígia Rodrigues Macedo",
      "orcid": "0000-0001-6969-6307"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/71m64dpn3qhzx.bib",
  "cited_by": 0,
  "doi": "10.3390/ph19101521",
  "fulltext_url": "https://europepmc.org/articles/PMC13708664",
  "id": "71m64dpn3qhzx",
  "issns": [
    "1424-8247"
  ],
  "landing_url": "https://europepmc.org/article/MED/42943218",
  "language": "eng",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "2404|Antimicrobial Peptides and Activities"
    ]
  ],
  "openalex": "W7214352353",
  "pdf_url": "https://europepmc.org/articles/PMC13708664?pdf=render",
  "pmcid": "PMC13708664",
  "pmid": "42943218",
  "published": "2026-09-25",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/71m64dpn3qhzx.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:22:24Z",
      "native_id": "MED:42943218",
      "source": "europepmc",
      "url": "https://europepmc.org/article/MED/42943218"
    }
  ],
  "subjects": [
    {
      "field": "biology",
      "origin": "openalex:2404|Antimicrobial Peptides and Activities",
      "subfield": "microbiology"
    }
  ],
  "title": "RQ18 Peptide Exerts Anti-Melanoma Effects via Apoptosis Induction.",
  "title_text": "RQ18 Peptide Exerts Anti-Melanoma Effects via Apoptosis Induction.",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:22:24Z",
  "url": "https://research.draconitic.com/paper/71m64dpn3qhzx",
  "venue": "Pharmaceuticals (Basel, Switzerland)",
  "versions": []
}