Cell communication network factor 4 (ccn4/wisp1) shifts Melanoma cells from a fragile proliferative to a resilient metastatic state and suppresses immune surveillance

While deregulated intracellular signaling initiates melanoma, patient survival is limited by progression and metastasis - processes often coordinated by secreted signals. Secreted signals can reinforce cell fate decisions by acting on the same cell and sustain pathology by influencing the stromal and immune cells present within the tumor microenvironment. Understanding how these secreted signals contribute to pathology remains a challenge as the relevance of a secreted signal depends highly on context. Identified by an unbiased phenotypic screen for inhibitors of immune cell crosstalk, Cell Communication Network Factor 4 (CCN4/WISP1) is a secreted matricellular protein that is upregulated in melanoma and breast cancer and correlates with a worse overall outcome. Here, I will discuss our recent in vitro and in vivo results to clarify the functional role that CCN4 plays in melanoma. Interestingly, we found that CCN4 shifts melanoma cells from a fragile proliferative to a resilient metastatic state. CCN4 drives this phenotypic shift by activating AKT Ser/Thr kinase and MEK/ERK signaling pathways that induce snail family transcriptional repressor 1 (SNAI1) expression. SNAI1 then initiates a transcriptional response similar to the epithelial-mesenchymal transition (EMT), including E-cadherin repression and fibronectin and N-cadherin induction. In vivo, knocking out CCN4 represses tumor metastasis of B16F10 and YUMM1.7 melanoma cells in syngeneic C57BL/6Ncrl and immunocompromised NOD-scid IL2Rgammanull (NSG) mice. While CCN4-KO variants of B16F10 and YUMM1.7 cells grow faster that WT cells both in vitro and in NSG mice, tumors initiated by CCN4-KO variants consistently grow slower in immunocompetent hosts. This reduction in tumor growth by CCN4-KO variants also corresponds to an increase in tumor-infiltrating lymphocytes. CCN4-KO variants of B16F0 and YUMM1.7 melanoma cells are also more responsive to immune checkpoint blockade. While some mechanistic details of this heterocellular crosstalk remain unclear, the results suggest an intriguing collateral target to both enhance the efficacy of immune checkpoint blockage and inhibit metastasis

Data-driven learning how oncogenic gene expression locally alters heterocellular networks

Developing drugs increasingly relies on mechanistic modeling and simulation. Models that capture causal relations among genetic drivers of oncogenesis, functional plasticity, and host immunity complement wet experiments. Unfortunately, formulating such mechanistic cell-level models currently relies on hand curation, which can bias how data is interpreted or the priority of drug targets. In modeling molecular-level networks, rules and algorithms are employed to limit a priori biases in formulating mechanistic models. Here we combine digital cytometry with Bayesian network inference to generate causal models of cell-level networks linking an increase in gene expression associated with oncogenesis with alterations in stromal and immune cell subsets from bulk transcriptomic datasets. We predict how increased Cell Communication Network factor 4, a secreted matricellular protein, alters the tumor microenvironment using data from patients diagnosed with breast cancer and melanoma. Predictions are then tested using two immunocompetent mouse models for melanoma, which provide consistent experimental results

Cardiac rehabilitation availability and characteristics in Latin America and the Caribbean: A global comparison

Background: This study aimed to establish availability and characteristics of cardiac rehabilitation (CR) in Latin America and the Caribbean (LAC), where cardiovascular disease is highly prevalent. Methods: In this cross-sectional sub-analysis focusing on the 35 LAC countries, local cardiovascular societies identified CR programs globally. An online survey was administered to identified programs, assessing capacity and characteristics. CR need was computed relative to ischemic heart disease (IHD) incidence from the Global Burden of Disease study. Results: ≥1 CR program was identified in 24 LAC countries (68.5% availability; median = 3 programs/country). Data were collected in 20/24 countries (83.3%); 139/255 programs responded (54.5%), and compared to responses from 1082 programs in 111 countries. LAC density was 1 CR spot per 24 IHD patients/year (vs 18 globally). Greatest need was observed in Brazil, Dominican Republic and Mexico (all with >150,000 spots needed/year). In 62.8% (vs 37.2% globally P < .001) of CR programs, patients pay out-of-pocket for some or all of CR. CR teams were comprised of a mean of 5.0 ± 2.3 staff (vs 6.0 ± 2.8 globally; P < .001); Social workers, dietitians, kinesiologists, and nurses were significantly less common on CR teams than globally. Median number of core components offered was 8 (vs 9 globally; P < .001). Median dose of CR was 36 sessions (vs 24 globally; P < .001). Only 27 (20.9%) programs offered alternative CR models (vs 31.1% globally; P < .01). Conclusion: In LAC countries, there is very limited CR capacity in relation to need. CR dose is high, but comprehensiveness low, which could be rectified with a more multidisciplinary team.This work was supported by a research grant from York University’s Faculty of Health, Toronto, Canada, and by project number LQ1605 from the National Program of Sustainability II (MEYS CR), Czech Republic

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Expression of H v 1 proton channels in myeloid-derived suppressor cells (MDSC) and its potential role in T cell regulation

Myeloid-derived suppressor cells (MDSC) are a heterogeneous cell population with high immunosuppressive activity that proliferates in infections, inflammation, and tumor microenvironments. In tumors, MDSC exert immunosuppression mainly by producing reactive oxygen species (ROS), a process triggered by the NADPH oxidase 2 (NOX2) activity. NOX2 is functionally coupled with the Hv1 proton channel in certain immune cells to support sustained free-radical production. However, a functional expression of the Hv1 channel in MDSC has not yet been reported. Here, we demonstrate that mouse MDSC express functional Hv1 proton channel by immunofluorescence microscopy, flow cytometry, and Western blot, besides performing a biophysical characterization of its macroscopic currents via patch-clamp technique. Our results show that the immunosuppression by MDSC is conditional to their ability to decrease the proton concentration elevated by the NOX2 activity, rendering Hv1 a potential drug target for cancer treatment

Novel Adjuvant Based on the Pore-Forming Protein Sticholysin II Encapsulated into Liposomes Effectively Enhances the Antigen-Specific CTL-Mediated Immune Response

Vaccine strategies to enhance CD8(+) CTL responses remain a current challenge because they should overcome the plasmatic and endosomal membranes for favoring exogenous Ag access to the cytosol of APCs. As a way to avoid this hurdle, sticholysin (St) II, a pore-forming protein from the Caribbean Sea anemone Stichodactyla helianthus, was encapsulated with OVA into liposomes (Lp/OVA/StII) to assess their efficacy to induce a CTL response. OVA-specific CD8(+) T cells transferred to mice immunized with Lp/OVA/StII experienced a greater expansion than when the recipients were injected with the vesicles without St, mostly exhibiting a memory phenotype. Consequently, Lp/OVA/StII induced a more potent effector function, as shown by CTLs, in vivo assays. Furthermore, treatment of E.G7-OVA tumor-bearing mice with Lp/OVA/StII significantly reduced tumor growth being more noticeable in the preventive assay. The contribution of CD4(+) and CD8(+) T cells to CTL and antitumor activity, respectively, was elucidated. Interestingly, the irreversibly inactive variant of the StI mutant StI W111C, encapsulated with OVA into Lp, elicited a similar OVA-specific CTL response to that observed with Lp/OVA/StII or vesicles encapsulating recombinant StI or the reversibly inactive StI W111C dimer. These findings suggest the relative independence between StII pore-forming activity and its immunomodulatory properties. In addition, StII-induced in vitro maturation of dendritic cells might be supporting these properties. These results are the first evidence, to our knowledge, that StII, a pore-forming protein from a marine eukaryotic organism, encapsulated into Lp functions as an adjuvant to induce a robust specific CTL response.Center of Molecular ImmunologyInternational Foundation for ScienceCAPES-MESUniv Havana, Ctr Prot Studies, Fac Biol, Calle 25 Entre J & I,455,Plaza Revoluc, Havana 10400, CubaCtr Mol Immunol, Immunobiol Div, Havana 11600, CubaUniv Fed Sao Paulo, Paulista Med Sch, Dept Microbiol Immunol & Parasitol, Discipline Immunol, BR-04023900 Sao Paulo, BrazilHarvard Med Sch, Dept Microbiol & Immunobiol, Boston, MA 02115 USAMcGill Univ, Goodman Canc Res Ctr, Montreal, PQ, CanadaMcGill Univ, Dept Biochem, Montreal, PQ, CanadaUniv Fed Sao Paulo, Paulista Med Sch, Dept Microbiol Immunol & Parasitol, Discipline Immunol, BR-04023900 Sao Paulo, BrazilCAPES-MES: 111/11Web of Scienc

Tumor-induced tolerance and immune suppression depend on the C/EBPbeta transcription factor.

Tumor growth is associated with a profound alteration in myelopoiesis, leading to recruitment of immunosuppressive cells known as myeloid-derived suppressor cells (MDSCs). We showed that among factors produced by various experimental tumors, the cytokines GM-CSF, G-CSF, and IL-6 allowed a rapid generation of MDSCs from precursors present in mouse and human bone marrow (BM). BM-MDSCs induced by GM-CSF+IL-6 possessed the highest tolerogenic activity, as revealed by the ability to impair the priming of CD8(+) T cells and allow long term acceptance of pancreatic islet allografts. Cytokines inducing MDSCs acted on a common molecular pathway and the immunoregulatory activity of both tumor-induced and BM-derived MDSCs was entirely dependent on the C/EBPbeta transcription factor. Adoptive transfer of tumor antigen-specific CD8(+) T lymphocytes resulted in therapy of established tumors only in mice lacking C/EBPbeta in the myeloid compartment, suggesting that C/EBPbeta is a critical regulator of the immunosuppressive environment created by growing cancers