DSP107 combines inhibition of CD47/SIRPα axis with activation of 4-1BB to trigger anticancer immunity

BACKGROUND: Treatment of Diffuse Large B Cell Lymphoma (DLBCL) patients with rituximab and the CHOP treatment regimen is associated with frequent intrinsic and acquired resistance. However, treatment with a CD47 monoclonal antibody in combination with rituximab yielded high objective response rates in patients with relapsed/refractory DLBCL in a phase I trial. Here, we report on a new bispecific and fully human fusion protein comprising the extracellular domains of SIRPα and 4-1BBL, termed DSP107, for the treatment of DLBCL. DSP107 blocks the CD47:SIRPα ‘don’t eat me’ signaling axis on phagocytes and promotes innate anticancer immunity. At the same time, CD47-specific binding of DSP107 enables activation of the costimulatory receptor 4-1BB on activated T cells, thereby, augmenting anticancer T cell immunity. METHODS: Using macrophages, polymorphonuclear neutrophils (PMNs), and T cells of healthy donors and DLBCL patients, DSP107-mediated reactivation of immune cells against B cell lymphoma cell lines and primary patient-derived blasts was studied with phagocytosis assays, T cell activation and cytotoxicity assays. DSP107 anticancer activity was further evaluated in a DLBCL xenograft mouse model and safety was evaluated in cynomolgus monkey. RESULTS: Treatment with DSP107 alone or in combination with rituximab significantly increased macrophage- and PMN-mediated phagocytosis and trogocytosis, respectively, of DLBCL cell lines and primary patient-derived blasts. Further, prolonged treatment of in vitro macrophage/cancer cell co-cultures with DSP107 and rituximab decreased cancer cell number by up to 85%. DSP107 treatment activated 4-1BB-mediated costimulatory signaling by HT1080.4-1BB reporter cells, which was strictly dependent on the SIRPα-mediated binding of DSP107 to CD47. In mixed cultures with CD47-expressing cancer cells, DSP107 augmented T cell cytotoxicity in vitro in an effector-to-target ratio-dependent manner. In mice with established SUDHL6 xenografts, the treatment with human PBMCs and DSP107 strongly reduced tumor size compared to treatment with PBMCs alone and increased the number of tumor-infiltrated T cells. Finally, DSP107 had an excellent safety profile in cynomolgus monkeys. CONCLUSIONS: DSP107 effectively (re)activated innate and adaptive anticancer immune responses and may be of therapeutic use alone and in combination with rituximab for the treatment of DLBCL patients. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13046-022-02256-x

Moderate hyperthermic heating encountered during thermal ablation increases tumor cell activity

Purpose The aim of this study was to determine whether moderate hyperthermic doses, routinely encountered in the periablational zone during thermal ablation, activate tumor cells sufficiently to secrete pro-tumorigenic factors that can induce increased proliferation. Material and methods R3230 rat mammary tumor cells and human cancer cell lines, MCF7 breast adenocarcinoma, HepG2 and Huh7 HCC, and HT-29 and SW480 colon adenocarcinoma, were heated in to 45 ± 1 °C or 43 ± 1 °C in vitro for 5-10 min and incubated thereafter at 37 °C for 1.5, 3 or 8 hr (n = 3 trials each; total N = 135). mRNA expression profiles of cytokines implicated in RF-induced tumorigenesis including IL-6, TNFα, STAT3, HGF, and VEGF, were evaluated by relative quantitative real-time PCR. HSP70 was used as control. c-Met and STAT3 levels were assessed by Western blot. Finally, naïve cancer cells were incubated with medium from R3230 and human cancer cells that were subjected to 43–45 °C for 5 or 10 min and incubated for 3 or 8 h at 37 °C in an xCELLigence or incuCyte detection system. Results Cell-line-specific dose and time-dependent elevations of at least a doubling in HSP70, IL-6, TNFα, STAT3, and HGF gene expression were observed in R3230 and human cancer cells subjected to moderate hyperthermia. R3230 and several human cell lines showed increased phosphorylation of STAT3 3 h post-heating and increased c-Met following heating. Medium of cancer cells subject to moderate hyperthermia induced statistically significant accelerated cell growth of all cell lines compared to non-heated media (p < 0.01, all comparisons). Conclusion Heat-damaged human tumor cells by themselves can induce proliferation of tumor by releasing pro-tumorigenic factors

The lncRNA H19-Derived MicroRNA-675 Promotes Liver Necroptosis by Targeting FADD

International audienceThe H19-derived microRNA-675 (miR-675) has been implicated as both tumor promoter and tumor suppressor and also plays a role in liver inflammation. We found that miR-675 promotes cell death in human hepatocellular carcinoma (HCC) cell lines. We show that Fas-associated protein with death domain (FADD), a mediator of apoptotic cell death signaling, is downregulated by miR-675 and a negative correlation exists between miR-675 and FADD expression in mouse models of HCC (p = 0.014) as well as in human samples (p = 0.017). We demonstrate in a mouse model of liver inflammation that overexpression of miR-675 promotes necroptosis, which can be inhibited by the necroptosis-specific inhibitor Nec-1/Nec-1s. miR-675 induces the level of both p-MLKL (Mixed Lineage Kinase Domain-Like Pseudokinase) and RIP3 (receptor-interacting protein 3), which are key signaling molecules in necroptosis, and enhances MLKL binding to RIP3. miR-675 also inhibits the levels of cleaved caspases 8 and 3, suggesting that miR-675 induces a shift from apoptosis to a necroptotic cellular pathway. In conclusion, downregulation of FADD by miR-675 promotes liver necroptosis in response to inflammatory signals. We propose that this regulation cascade can stimulate and enhance the inflammatory response in the liver, making miR-675 an important regulator in liver inflammation and potentially also in HCC

Inflammation-Induced Expression and Secretion of MicroRNA 122 Leads to Reduced Blood Levels of Kidney-derived Erythropoietin and Anemia

BACKGROUND & AIM Anemia is commonly associated with acute and chronic inflammation, but the mechanisms of their interaction are not clear. We investigated whether microRNA 122 (MIR122), which is generated in the liver and is secreted into the blood, is involved in the development of anemia associated with inflammation. METHODS We characterized the primary transcript of the human liver-specific MIR122 using northern blot, quantitative real-time PCR, and 3' and 5' RACE analyses. We studied regulation of MIR122 in human hepatocellular carcinoma (HCC) cell lines (Huh7 and HepG2) as well as in C57BL/6 and mice with disruption of the tumor necrosis factor gene (Tnf). Liver tissues were collected and analyzed by bioluminescence imaging or immunofluorescence. Inflammation in mice was induced by lipopolysaccharide (LPS) or by cerulein injections. Mice were given 4 successive injections of LPS, leading to inflammation-induced anemia. Steatohepatitis was induced with a choline-deficient high-fat diet. Hemolytic anemia was stimulated by phenylhydrazine injection. MIR122 was inhibited in mice by tail-vein injection of antogomiR-122 (an oligonucleotide antagonist of MIR122). MicroRNA and mRNA levels were determined by quantitative real time PCR. RESULTS The primary transcript of MIR122 spanned 5 kb, comprising 3 exons; the third encodes MIR122. Within the MIR122 promoter region we identified a nuclear factor-κB (NF-κB) binding site and demonstrated that RELA, as well as activators of NF-κB (TNF and LPS), increased promoter activity of MIR122. Administration of LPS to mice induced secretion of MIR122 into blood, which required TNF. Secreted MIR122 reached the kidney and reduced expression of erythropoietin (Epo), which we identified as a MIR122 target gene. Injection of mice with antagomiR-122 increased blood levels of EPO, reticulocytes, and hemoglobin. We found an inverse relationship between blood levels of MIR122 and EPO in mice with acute pancreatitis or steatohepatitis, and also in patients with acute inflammation. CONCLUSION In mice, we found that LPS-induced inflammation increases blood levels of MIR122, which reduces expression of Epo in the kidney; this is a mechanism of inflammation-induced anemia. Strategies to block MIR122 in patients with inflammation could reduce the development or progression of anemia

Additional file 1 of DSP107 combines inhibition of CD47/SIRPα axis with activation of 4-1BB to trigger anticancer immunity

Additional file 1. [43–45]