Fn14•Trail effectively inhibits hepatocellular carcinoma growth.

BACKGROUND: New strategies for the treatment of hepatocellular carcinoma (HCC) are needed, given that currently available chemotherapeutics are inefficient. Since tumor growth reflects the net balance between pro-proliferative and death signaling, agents shifting the equilibrium toward the latter are of considerable interest. The TWEAK:Fn14 signaling axis promotes tumor cell proliferation and tumor angiogenesis, while TRAIL:TRAIL-receptor (TRAIL-R) interactions selectively induce apoptosis in malignant cells. Fn14•TRAIL, a fusion protein bridging these two pathways, has the potential to inhibit tumor growth, by interfering with TWEAK:Fn14 signaling, while at the same time enforcing TRAIL:TRAIL-R-mediated apoptosis. Consequently, Fn14•TRAIL\u27s capacity to inhibit HCC growth was tested. RESULTS: Fn14•TRAIL induced robust apoptosis of multiple HCC cell lines, while sparing non-malignant hepatocyte cell lines. Differential susceptibility to this agent did not correlate with expression levels of TRAIL, TRAIL-R, TWEAK and Fn14 by these lines. Fn14•TRAIL was more potent than soluble TRAIL, soluble Fn14, or a combination of the two. The requirement of both of Fn14•TRAIL\u27s molecular domains for function was established using blocking antibodies directed against each of them. Subcutaneous injection of Fn14•TRAIL abrogated HCC growth in a xenograft model, and was well tolerated by the mice. CONCLUSIONS: In this study, Fn14•TRAIL, a multifunctional fusion protein originally designed to treat autoimmunity, was shown to inhibit the growth of HCC, both in vitro and in vivo. The demonstration of this fusion protein\u27s potent anti-tumor activity suggests that simultaneous targeting of two signaling axes by a single fusion can serve as a basis for highly effective anti-cancer therapies

The DNA damage response pathway regulates the expression of the immune checkpoint CD47

CD47 is a cell surface ligand expressed on all nucleated cells. It is a unique immune checkpoint protein acting as “don’t eat me” signal to prevent phagocytosis and is constitutively overexpressed in many tumors. However, the underlying mechanism(s) for CD47 overexpression is not clear. Here, we show that irradiation (IR) as well as various other genotoxic agents induce elevated expression of CD47. This upregulation correlates with the extent of residual double-strand breaks (DSBs) as determined by γH2AX staining. Interestingly, cells lacking mre-11, a component of the MRE11-RAD50-NBS1 (MRN) complex that plays a central role in DSB repair, or cells treated with the mre-11 inhibitor, mirin, fail to elevate the expression of CD47 upon DNA damage. On the other hand, both p53 and NF-κB pathways or cell-cycle arrest do not play a role in CD47 upregualtion upon DNA damage. We further show that CD47 expression is upregulated in livers harvested from mice treated with the DNA-damage inducing agent Diethylnitrosamine (DEN) and in cisplatin-treated mesothelioma tumors. Hence, our results indicate that CD47 is upregulated following DNA damage in a mre-11-dependent manner. Chronic DNA damage response in cancer cells might contribute to constitutive elevated expression of CD47 and promote immune evasion.</p

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

Heart rate response to blood pressure variations: sympathetic activation versus baroreflex response in patients with end-stage renal disease.

BACKGROUND:Continuous systolic blood pressure (SBP) and interbeat intervals (IBI) recordings reveal sequences of consecutive beats in which SBP and heart rate change in opposite direction, representing negative feedback baroreflex mechanisms, as well as sequences in which SBP and heart rate change in the same direction (non-baroreflex), believed to represent feedforward control mechanisms. The present study was undertaken to assess the relationship between baroreflex and non-baroreflex sequences in end stage renal insufficiency. METHODOLOGY/PRINCIPAL FINDINGS:Continuous beat-to-beat SBP and IBI monitoring was performed in patients on chronic hemodialysis (HD, n=72), in age-matched patients after renal transplantation (TX, n=41) and healthy (control) individuals (C, n=34). The proportion of baroreflex and nonbaroreflex episodes and the b coefficients (the regression line slope of SBP-IBI correlation) were determined using a newly developed 1 minute sliding window method, the classical sequence technique and the "Z" coefficient method. Analysis using the 1 minute sliding window showed an increased proportion of baroreflex episodes in controls and HD, and predominance of nonbaroreflex episodes in TX. An increased proportion of nonbaroreflex episodes in TX patients relative to HD was also revealed by the "Z" method. Baroreflex and nonbaroreflex b coefficients obtained by all methods were markedly decreased in HD. This alteration was reversed at least partly in TX. In HD, both baroreflex and nonbaroreflex b coefficients were inversely correlated to age and CRP levels; in TX, the nonbaroreflex b coefficient was influenced by the type of calcineurin inhibitor. CONCLUSION/SIGNIFICANCE:Renal status affects the contribution of baroreflex and nonbaroreflex mechanisms and the strength of SBP-IBI relationship. The predominant contribution of nonbaroreflex mechanisms in TX may be suggestive of enhanced central sympathetic control. Our data may be relevant for understanding of the pathogenesis and selection of appropriate treatment of post-transplant hypertension

IBI-SBP regression slopes of baroreflex and nonbaroreflex episodes obtained by the 1 min sliding window analysis (<i>b</i>_<i>al</i>), by the sequence method (<i>b</i>_<i>seq</i>), and by the "Z" technique (<i>b</i>_z) in control (C, •), in hemodialysis (HD, ♦) and in transplanted (TX,■) patients.

<p>IBI-SBP regression slopes of baroreflex and nonbaroreflex episodes obtained by the 1 min sliding window analysis (<i>b</i>_<i>al</i>), by the sequence method (<i>b</i>_<i>seq</i>), and by the "Z" technique (<i>b</i>_z) in control (C, •), in hemodialysis (HD, ♦) and in transplanted (TX,■) patients.</p

Correlations of baroreflex and nonbaroreflex <i>b</i>_<i>sl</i> slopes (absolute values) with age and with LFα and HFα indices in control (C), in hemodialysis (HD) and in transplanted (TX) patients.

<p>Correlations of baroreflex and nonbaroreflex <i>b</i>_<i>sl</i> slopes (absolute values) with age and with LFα and HFα indices in control (C), in hemodialysis (HD) and in transplanted (TX) patients.</p

Baroreflex and non-baroreflex function determined by three methods.

<p>SBP-systolic blood pressure; IBI-interbeat interval; HR- heart rate. (<b>a</b>) The sliding window method: SBP and IBI tracings and their correlations during a baroreflex episode (SBP and IBI change in the same direction, upper panel) and during a non-baroreflex episode (SBP and IBI change in different directions, lower panel). (<b>b</b>) The sequence technique: SBP and IBI tracings and their correlations during baroreflex episodes (SBP and IBI change in the same direction, increased or decreased SBP, upper panels) and during nonbaroreflex episodes (SBP and IBI change in opposite directions, increased or decreased SBP, lower panels). (<b>c</b>) The "Z" method: Three dimensional histogram for couples of SBP and HR. The modal class (the maximal, most frequent HR-SBP histogram value) was taken as a set point of spontaneous activity. The SBP-HR pair classes in quadrant 1 (low SBP associated with high HR values) and in quadrant 3 (high SBP associated with low HR values) are representative of baroreflex episodes, while quadrants 2 (low SBP with low HR) and 4 (high SBP with high HR) represent non-baroreflex episodes. Regression lines and correlation coefficients are shown for baroreflex episodes (quadrants 1 and 3) and for nonbaroreflex episodes (quadrants 2 and 4).</p

Representative tracings of <i>b</i>_<i>sl</i> (the slope of 1 min IBI-SBP regression line assessed by 1 min sliding window method), and r-the correlation coefficient as a function of time during the whole session of the recording in a control (upper panels, A) individual and in a transplanted patient (lower panels, B).

<p>The bold portions of <b><i>b</i>_<i>sl</i></b> tracings represent epochs with a correlation coefficient (r) between IBI and SBP greater than 0.5. In the control patient’s tracing, 55% of episodes in such epochs were baroreflex with a positive <i>b</i>_<i>sl</i>, while the remaining 45% were non-baroreflex with a negative <i>b</i>_<i>sl</i>. A similar tracing for a transplanted patient is shown in Figure 4, lower panel. In this patient, all sequences (100%) were nonbaroreflex episodes.</p