Doxorubicin-induced Immunogenic Cell Death Impairs Tumor Progression and Distant Metastasis in a 4T1 Breast Cancer Tumor Model

Introduction: Cancer is an individual disease and its formation and development are specific to each host. Conventional treatments are ineffective in complex cases, such as metastasis, and have severe adverse side effects. New strategies are needed to address the problem, and the use of immunogenic cell death (ICD) as a trigger or booster of the immune system through the exposure of damage-associated molecular patterns, along with tumor antigens, by cancerous cells is presented as an immunization approach in this work. Methods: For this purpose, 4T1 cells were exposed to doxorubicin (DOX) for 24 hours and then, these cells undergoing ICD were subcutaneously administered to mice. The ICD induction by DOX on 4T1 was assessed by flow cytometry and image analysis. This immunization process was performed three times and after the last administration, the immunized mice were challenged with a subcutaneous xenograft of live cancer cells. Results: The results demonstrate that the mice immunized with cells undergoing ICD after exposure to DOX presented no primary tumor or indications of distant metastatic lesion development. Conclusion: In summary, our findings indicate that the immunization process utilizing ICD is indeed efficacious in managing this aggressive form of pre-clinical breast cancer.