Chromomycin A5 induces bona fide immunogenic cell death in melanoma

Katharine Gurgel Dias Florêncio; Evelline Araújo Edson; Keilla Santana da Silva Fernandes; João Paulo Mesquita Luiz; Francisco das Chagas Lima Pinto; Otília Deusdênia Loiola Pessoa; Fernando de Queiroz Cunha; João Agostinho Machado-Neto; Diego Veras Wilke

doi:10.3389/fimmu.2022.941757

Chromomycin A₅ induces bona fide immunogenic cell death in melanoma

Front Immunol. 2022 Nov 9:13:941757. doi: 10.3389/fimmu.2022.941757. eCollection 2022.

Authors

Katharine Gurgel Dias Florêncio¹, Evelline Araújo Edson¹, Keilla Santana da Silva Fernandes¹, João Paulo Mesquita Luiz², Francisco das Chagas Lima Pinto³, Otília Deusdênia Loiola Pessoa³, Fernando de Queiroz Cunha², João Agostinho Machado-Neto⁴, Diego Veras Wilke¹

Affiliations

¹ Drug Research and Development Center, Department of Physiology and Pharmacology, School of Medicine, Federal University of Ceara, Ceara, Brazil.
² Center for Research in Inflammatory Diseases (CRID), Ribeirão Preto Medical School, University of São Paulo, São Paulo, Brazil.
³ Department of Organic and Inorganic Chemistry, Sciences Center, Federal University of Ceara, Ceara, Brazil.
⁴ Department of Pharmacology, Institute of Biomedical Sciences, University of Sao Paulo, São Paulo, Brazil.

Abstract

Purpose: Some first-line cytotoxic chemotherapics, e.g. doxorubicin, paclitaxel and oxaliplatin, induce activation of the immune system through immunogenic cell death (ICD). Tumor cells undergoing ICD function as a vaccine, releasing damage-associated molecular patterns (DAMPs), which act as adjuvants, and neoantigens of the tumor are recognized as antigens. ICD induction is rare, however it yields better and long-lasting antitumor responses to chemotherapy. Advanced metastatic melanoma (AMM) is incurable for more than half of patients. The discovery of ICD inducers against AMM is an interesting drug discovery strategy with high translational potential. Here we evaluated ICD induction of four highly cytotoxic chromomycins A (CA_5-8).

Methods: ICD features and DAMPs were evaluated using several in vitro techniques with metastatic melanoma cell line (B16-F10) exposed to chromomcins A_5-8 such as flow cytometry, western blot, RT-PCR and luminescence. Additionally in vivo vaccination assays with CA₅-treated cells in a syngeneic murine model (C57Bl/6) were performed to confirm ICD evaluating the immune cells activation and their antitumor activity.

Results: B16-F10 treated with CA_5-8 and doxorubicin exhibited ICD features such as autophagy and apoptosis, externalization of calreticulin, and releasing of HMGB1. However, CA₅-treated cells had the best profile, also inducing ATP release, ERp57 externalization, phosphorylation of eIF2α and altering expression of transcription of genes related to autophagy, endoplasmic reticulum stress, and apoptosis. Bona fide ICD induction by CA₅ was confirmed by vaccination of C57BL/6 mice with CA₅-treated cells which activated antigen-presenting cells and T lymphocytes and stimulated antitumor activity.

Conclusion: CA₅ induces bona fide immunogenic cell death on melanoma.

Keywords: anticancer; autophagy; cancer immunotherapy; chromomycin; drug discovery; immunogenic cell death; marine natural products; metastatic melanoma.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Alarmins
Animals
Antineoplastic Agents* / pharmacology
Antineoplastic Agents* / therapeutic use
Cell Line, Tumor
Doxorubicin
Immunogenic Cell Death
Melanoma* / drug therapy
Mice
Mice, Inbred C57BL
T-Lymphocytes

Substances

Antineoplastic Agents
Doxorubicin
Alarmins