Doxorubicin treatment induces tumor cell death followed by immunomodulation in a murine neuroblastoma model

Abstract

Chemotherapy of malignant tumors induces tumor cell death. Numerous antitumor agents induce apoptosis of tumor cells, which are subsequently engulfed by phagocytes, initiating an immune reaction. The induction of immunogenic cell death by antitumor agents may be advantageous for antitumor immunity. The purpose of this study was to determine whether doxorubicin is capable of inducing an immunogenic reaction in murine neuroblastoma cells. The murine neuroblastoma cell line (neuro-2a cells) was cultured in a medium containing doxorubicin or cisplatin (CDDP), and induction of cell death was confirmed by cell viability assays. Cluster of differentiation (CD)8α+ lymphocytes were co-cultured with neuro-2a cells that had died following treatment with either doxorubicin or CDDP, and CD11b+ spleen cells or bone marrow-derived dendritic cells (BM-DCs) were added to the culture. Proliferation of CD8α+ lymphocytes and interferon (IFN)-γ production were evaluated. When CD8α+ cells were co-cultured with doxorubicin-treated neuro-2a cells and BM-DCs, CD8α+ cells reacted to anti-CD3/CD28 antibody stimulation, proliferated and increased IFN-γ production. IFN-γ production was more effectively promoted by co-culture with doxorubicin-treated neuro-2a cells than by co-culture with CDDP-treated neuro-2a cells. These findings suggest that doxorubicin is capable of inducing immunogenic cell death in neuroblastoma cells, and thus has an immunological advantage for chemotherapy of neuroblastoma compared with CDDP. BM-DCs are considered to be the key antigen-presenting cells in the immune reaction following the induction of immunogenic neuroblastoma cell death and phagocytosis.

Fasting-Mimicking Diet Reduces HO-1 to Promote T Cell-Mediated Tumor Cytotoxicity

“…Although all mice were “immunized” by grafting the same number of live pre-conditioned breast cancer cells, DXR and STS+DXR groups did not develop tumors ( Figures 3J and S4F ). Consistent with previous studies (Casares et al, 2005; Inoue et al, 2014), “naïve” tumors on the other flank displayed retarded growth after 4 weeks in mice grafted with cells pre-cultured with DXR ( Figure 3K ). Notably, STS-preconditioning alone was more effective than STS+DXR, possibly because the less severe apoptotic effects of the STS allowed the immunogenic cancer cells to live longer and therefore provide a prolonged immunogenic stimuli after grafting in mice ( Figures 3J, 3K, and S4F ).…”

Cytokines in immunogenic cell death: Applications for cancer immunotherapy

“…Multiple studies indicate that the dosage of ICD agents is a key component associated with the release of DAMPs as well as the activation of the immune system [28, 29]. The effects of doxorubicin (DOX) and idarubicin (IDA), two well-characterized anthracyclines, were examined using acute lymphoblastic leukemia (REH ALL, HLA-A2+), ovarian cancer (OV90, HLA-A2+), and prostate cancer (LNCap, HLA-A2+) cell lines [9].…”

“…While both DOX and IDA treatments caused apoptosis in the cancer cell lines studied, the dose at which these drugs triggered ICD was generally higher than the dose needed to achieve cytotoxicity[30] [31] [32]. As example, when DOX was used to treat murine neuro-2a neuroblastoma cells (IC 50 = 30 nM [33]) a dose of 1.6 μM and higher was required to produce immunogenic dying cancer cells [28]. …”

“…These matured DCs also had the ability to activate tumor-specific T cells [9]. When DOX (1.6 μM) was used to treat murine neuro-2a neuroblastoma cells, both CD11b+ spleen cells and primary bone marrow-derived dendritic cells (BM-DCs) phagocytosed the treated neuro-2A cells in vitro [28]. The third study, using OXA-NPs (4 μM) to treat pancreatic cancer cells, assessed the ability of secreted DAMPs to stimulate DC maturation.…”

“…When dying DOX-treated (1.6 μM) neuro-2a cells were co-cultured with both CDb11b+ spleen cells and CD8+ T cells, IFN-γ levels in the culture supernatants were 40,000 pg/mL, which was four fold higher as compared to basal levels of 10,000 pg/mL or less, indicating that effector T cells were generated. The activation of T cells was not solely due to the apoptotic cell death of the cancer cells, since the same cancer cells when treated with cisplatin, which kills cells but does not cause ICD, did not result in more IFN-γ-producing T cells [28]. …”