Tumor-associated Inflammation Research Articles

Tumor-Associated Inflammation: The Tumor-Promoting Immunity in the Early Stages of Tumorigenesis.

Tumorigenesis is a multistage progressive oncogenic process caused by alterations in the structure and expression level of multiple genes. Normal cells are continuously endowed with new capabilities in this evolution, leading to subsequent tumor formation. Immune cells are the most important components of inflammation, which is closely associated with tumorigenesis. There is a broad consensus in cancer research that inflammation and immune response facilitate tumor progression, infiltration, and metastasis via different mechanisms; however, their protumor effects are equally important in tumorigenesis at earlier stages. Previous studies have demonstrated that during the early stages of tumorigenesis, certain immune cells can promote the formation and proliferation of premalignant cells by inducing DNA damage and repair inhibition, releasing trophic/supporting signals, promoting immune escape, and activating inflammasomes, as well as enhance the characteristics of cancer stem cells. In this review, we focus on the potential mechanisms by which immune cells can promote tumor initiation and promotion in the early stages of tumorigenesis; furthermore, we discuss the interaction of the inflammatory environment and protumor immune cells with premalignant cells and cancer stem cells, as well as the possibility of early intervention in tumor formation by targeting these cellular mechanisms.

Activation of Host-NLRP3 Inflammasome in Myeloid Cells Dictates Response to Anti-PD-1 Therapy in Metastatic Breast Cancers.

Tumor-associated inflammation leads to dysregulated cytokine production that promotes tumor immune evasion and anti-tumor immunity dysfunction. In advanced stage breast cancer, the proinflammatory cytokine IL-1β is overexpressed due to large proportions of activated myeloid cells in the tumor microenvironment (TME). Here, we demonstrate the role of the host nucleotide-binding domain, leucine-rich containing family, pyrin domain-containing 3 (NLRP3) inflammasome in metastatic breast cancer. In vitro, we show that stimulation of THP-1 cells with conditioned media collected from MDA-MB-468 cells induced NLRP3 activation and increased Pdcd1l1 expression. In vivo, mice deficient in NLRP3 orthotopically implanted with metastatic breast cancer cell line (E0771) showed significant reduction in tumor growth (p < 0.05) and increased survival (p < 0.01). Inhibition of NLRP3 with the small molecule OLT1177® reduced expression of Pdcd1l1 (p < 0.001), Casp1 (p < 0.01) and Il1b (p < 0.01) in primary tumors. Furthermore, tumor-bearing mice receiving OLT1177® showed reduced infiltration of myeloid-derived suppressor cells (MDSCs) (p < 0.001) and increased CD8+ T cells (p < 0.05) and NK cells (p < 0.05) in the TME. NLRP3 inhibition in addition to anti-PD-1 treatment significantly reduced tumor growth from the monotherapies (p < 0.05). These data define NLRP3 activation as a key driver of immune suppression in metastatic breast cancers. Furthermore, this study suggests NLRP3 as a valid target to increase efficacy of immunotherapy with checkpoint inhibitor in metastatic breast cancers.

Lung cancer shapes commensal bacteria via exosome-like nanoparticles

Tumor microenvironment (TME) is a dynamic niche for tumorigenesis and progression. Emerging evidence has shed light on the unusual role of commensal microbiota in the TME across various tumors. Microbiota can have long-time exist in the TME or even in tumor cells without uncontrolled proliferation and fatal infection to tumor cells, and it can interact with tumor cells when they coexist. Specific microbiota can contribute to carcinogenesis by inducing tumor-associated inflammation, producing immunosuppressive factors, and releasing detrimental metabolites. But less is known about how the tumor cells can exert effects and modulate the commensal microbiota. In this study, we found that the tumor tissues of patients with lung adenocarcinoma were enriched with Staphylococcus aureus (S. aureus) relative to the adjacent tissues, and the lung cancer-derived exosome-like nanoparticles (ELNs) can be internalized by S. aureus, the treatment of lung cancer-derived ELNs altered the bacterial morphology, reduced the adhesion ability, biofilm formation and the virulence of S. aureus, the activation of ArlS-ArlR two-component system may be one of the potential mechanisms under the above phenomenon. It is a novel revelation of the crosstalk between tumor cells and the commensal microbiota.

The Role of Extracellular Matrix Proteins in Breast Cancer.

The extracellular matrix is a structure composed of many molecules, including fibrillar (types I, II, III, V, XI, XXIV, XXVII) and non-fibrillar collagens (mainly basement membrane collagens: types IV, VIII, X), non-collagenous glycoproteins (elastin, laminin, fibronectin, thrombospondin, tenascin, osteopontin, osteonectin, entactin, periostin) embedded in a gel of negatively charged water-retaining glycosaminoglycans (GAGs) such as non-sulfated hyaluronic acid (HA) and sulfated GAGs which are linked to a core protein to form proteoglycans (PGs). This highly dynamic molecular network provides critical biochemical and biomechanical cues that mediate the cell–cell and cell–matrix interactions, influence cell growth, migration and differentiation and serve as a reservoir of cytokines and growth factors’ action. The breakdown of normal ECM and its replacement with tumor ECM modulate the tumor microenvironment (TME) composition and is an essential part of tumorigenesis and metastasis, acting as key driver for malignant progression. Abnormal ECM also deregulate behavior of stromal cells as well as facilitating tumor-associated angiogenesis and inflammation. Thus, the tumor matrix modulates each of the classically defined hallmarks of cancer promoting the growth, survival and invasion of the cancer. Moreover, various ECM-derived components modulate the immune response affecting T cells, tumor-associated macrophages (TAM), dendritic cells and cancer-associated fibroblasts (CAF). This review article considers the role that extracellular matrix play in breast cancer. Determining the detailed connections between the ECM and cellular processes has helped to identify novel disease markers and therapeutic targets.

Abstract P014: Driving immune-dependent metabolic vulnerabilities in the breast tumor microenvironment

Abstract The tumor microenvironment (TME) is a complex arms race composed of host stroma and rapidly adapting cancer cells. This symbiosis is further complicated when dissecting the influence of inflammation, due to its multifaceted function within the TME as a driver of both pro- and anti-tumor responses. Comprising a major component of the TME, targeting or exploiting tumor-associated inflammation has long been sought for therapeutic purposes. However, the optimal amount and composition of inflammation for such purposes remains elusive. We have recently identified an interferon (IFN)-dependent transcriptional response in breast cancer cells that renders a unique sensitivity to oxidative stress produced by the biguanide-class complex I inhibitor, phenformin. Using syngeneic murine models representing luminal B (PyMT) and basal (4T1) breast cancer, we identified a modest sensitivity to phenformin administration in vivo. However, phenformin effectiveness is dramatically enhanced when used in combination with the toll-like receptor 3 (TLR3) agonist, polyinosinic:polycytidylic acid (poly (I:C)). Critically, the effectiveness of this combination treatment was lost when performed in immune-deficient mice (SCID-beige), indicating that an immune component was essential. These findings highlight a novel role for inflammation and the immune system to promote sensitivity to oxidative stress in the TME. By identifying cell types responsible for cultivating a microenvironment conducive to biguanide sensitivity in breast cancer, we can identify a novel immune-biomarker of complex I sensitivity. Therefore, using high-parameter flow cytometry, we are analyzing systemic and tumor-infiltrating leukocyte diversity and enumeration in both our genetically and phenotypically distinct breast cancer models. Combination-therapy-induced immune populations will be further characterized in their molecular and cellular response to TLR agonism and complex I inhibition. Functional responses such as inflammatory-mediator production, immunomodulatory activity, and direct and indirect tumor cytotoxicity will be assessed, ex vivo. Furthermore, monoclonal antibody-mediated depletion of candidate cell types will be used to validate their requirement and contribution to the observed synergy to the combination therapy. Examples of tumoricidal synergy between biguanides and the inflammatory TLR agonists have not yet been described, establishing these findings as novel additions to the field of tumor biology. Furthermore, identifying how sensitivity to oxidative stress can become situationally immune-dependent can greatly advance our understanding of how inflammation and metabolism intersect within the TME. Citation Format: John Heath, Stephanie Totten, Young Kyuen Im, Valerie Sabourin, Kathryn Hunt, Josie Ursini-Siegel. Driving immune-dependent metabolic vulnerabilities in the breast tumor microenvironment [abstract]. In: Abstracts: AACR Virtual Special Conference: Tumor Immunology and Immunotherapy; 2021 Oct 5-6. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(1 Suppl):Abstract nr P014.

Proinflammatory cytokines and circulating tumor cells in ovarian cancer patients treated with platinum-containing chemotherapy

Summary. Circulating tumor cells (CTCs) are a potential source of tumor progression. Systemic tumor-associated inflammation can influence the cancer prognosis both independently and by changing the characteristics of CTCs. Data on the role of proinflammatory cytokines and CTCs in the ovarian cancer (OC) chemosensitivity are few and contradictory. Aim of the study. To assess the IL-17A, IL-18 levels and the number of CTCs in primary patients with OC before treatment and after 3 courses of standard platinum-containing chemotherapy, and the possibility of using these cytokines as a marker of the presence of CTCs. Materials and methods. The study included 72 patients with OC. The comparison group included 16 patients with benign ovarian tumors, the control group included 20 healthy women. The number of CTCs (CD45-/EpCam+/CK+) was determined immunofluorometrically before and after 3 courses of chemotherapy. The content of cytokines was assessed by ELISA. Statistica 13.0, jamovi 1.6.5.0 were used for data processing. Results. The level of IL-17A in blood in the benign tumors group was increased in comparison with OC (р=0.012) and control (р=0.042). The content of IL-17A increased over time in the subgroup of adjuvant chemotherapy (р=0.017). During treatment, IL-17A was higher among patients with platinum-sensitive tumors than with non-sensitive ones (р=0.054). High levels of IL-18 before treatment were associated with the development of platinum-refractory relapse (р=0.014). IL-18 levels before (р=0.027) and during treatment (p=0.052) were lower in patients with cytoreductive surgery in first line of treatment. Progression-free survival (PFS) (p = 0.012) and overall survival (OS) (p = 0.030) were lower in the cluster with high IL-18 and pretreatment leukocyte counts than in the cluster with low scores. Higher quantity of the pretreatment CTCs was associated with longer PFS in a multivariate analysis (HR 0.82 95% CI 0.69–0.98, р=0.028). The number of CTCs before treatment greater than 5 was associated with a decrease in OS (HR 1.31, 95% CI 0.98–1.73, р=0.064). Conclusions. A high level of IL-17A in the blood during treatment is associated with more favorable clinical characteristics of OC, while a high level of IL-18 in the blood before treatment is associated with less favorable characteristics and a worse prognosis. The number of CTCs in patients with OC is not related to the blood levels of IL-17A and IL-18. A greater number of CTCs before treatment in OC is associated with an increase in PFS, but a decrease in overall survival.

Role of pre-metastatic niche in organ specificity of breast cancer metastasis. Influence on metastatic potential as a basis for CDK4/6-inhibition efficacy in early therapy of disseminated hormone-receptor-positive disease

Influencing the pre-metastatic niche is a very perspective cancer treatment strategy in order of preventing metastases formation. It was found that bone marrow progenitor cells and tumor cells secreting biological compounds are key components in the formation of the pre-metastatic niche. Myeloid suppressor cells (MSCs) are the main type of bone marrow cells in pre-metastatic niches. At the same time, tumor-associated chronic inflammation induces the expression of proinflammatory cytokines triggering myeloid cells differentiation into myeloid suppressor cells. When circulating tumor cells enter the circulatory channel, their interaction with immune cells is observed, which additionally influences the pre-metastatic site preparation. Studies have shown that the entire spectrum of immune cells is capable of influencing the metastasis formation by circulating tumor cells. The epithelialmesenchymal transition with the tumor cell transporting form appearence was found to be related to the function of the ZEB1 protein. Its activity is regulated by numerous signaling mechanisms at the transcriptional level, including TGFβ, Wnt and Notch. This initiates epithelial-mesenchymal transition of breast cancer cells. Zhang Z.et al. proved that CDK4/6 blocking leads ZEB1 protein stability decreasing, preventing metastasis in breast cancer in vitro and in vivo. Moreover, USP51 deubiquitinase has been identified as a target of cyclin-dependent 4/6 kinases. At the molecular level, CDK4/6 phosphorylate and activates USP51, which then influences ZEB1 deubiquitination and stabilization. A positive correlation was demonstrated between the expression of p-RB (an indicator of CDK4/6 activity), p-USP51 and ZEB1 in breast cancer samples. Thus, the CDK4/6-USP51-ZEB1 axis may play a key role in the metastasis of breast cancer. In breast cancer cells, inhibition of CDK4/6 was shown to increase the expression of E-cadherin but decrease the expression of mesenchymal markers, reducing the migratory ability and invasiveness of breast cancer cell lines. This biological effect may also explain the clinical efficacy of the CDK4/6 inhibitor Abemaciclib in early-line therapy of metastatic breast cancer as well as in adjuvant combination hormone therapy for the prevention of metastatic lesions in patients at high risk of recurrence and progression in the MONARCH E study. Besides, there were no response predictors evaluated in trials investigating CDK4/6 in breast cancer treatment and it is unknown if there any differences in treatment response according to the metastatic site. The clinical cases demonstrate abemaciclib clinical efficacy in metastatic breast cancer treatment regardless of metastatic site.

A protocol for phase II study investigating the safety and efficacy of TM5614 in combination with nivolumab in the treatment of unresectable malignant melanoma

Abstract Introduction: Plasminogen activating inhibitor-1 (PAI-1) plays a significant role in the development of various cancers, including melanomas, and modulation of tumor-associated inflammation is one of the key anti-tumor functions of PAI-1. A recent report suggested that PAI-1 inhibitors suppress the expression of programmed cell death 1 ligand 1 (PD-L1) on tumor-associated macrophages (TAMs), suppressing the induction of regulatory T cells and promoting anti-melanoma immune responses. Methods and analysis: This is a single-arm, open-label, multi-institutional, phase 2 clinical trial to assess the efficacy and safety of nivolumab in combination with TM5614 (pPAI-1 inhibitor) in patients with advanced malignant melanoma. Nivolumab will be administered every 4 weeks, and TM5614 will be administered daily for 8 weeks. For the first-line cohort, assuming the null hypothesis of a response rate of 22.2% and an alternative hypothesis of 40%, a minimum of 22 patients are required to achieve a two-sided, type I error of 5% and power of 70% based on the exact binomial distribution. For the second-line and beyond cohorts, assuming the null hypothesis of a response rate of 5% and the alternative hypothesis of 22.2%, a minimum of 18 patients are required to achieve a two-sided, type I error of 5%, and power of 70% based on the exact binomial distribution. Discussion: This study will contribute to the development of novel combination therapy for anti- programmed cell death 1 antibodies-resistant advanced melanoma patients, which remains an unmet clinical need. Trial registration: Trial registration number: jRCT2021210029

NAP1051, a Lipoxin A4 Biomimetic Analogue, Demonstrates Antitumor Activity Against the Tumor Microenvironment.

Resolving tumor-associated inflammation in the tumor microenvironment (TME) may promote antitumor effects. Lipoxin A4 (LXA4) is a short-lived endogenous bioactive lipid with potent anti-inflammatory and pro-resolving properties. Here, a biomimetic of LXA4, NAP1051, was shown to have LXA4-like in vitro properties and antitumor activity in colorectal cancer xenograft models. NAP1051 inhibited neutrophil chemotaxis toward fMLP and dose-dependently promoted dTHP-1 efferocytosis which was equipotent to aspirin-triggered lipoxin A4 (ATLA). In dTHP-1 cells, NAP1051 induced strong phosphorylation on ERK1/2 and AKT similar to formyl peptide receptor 2 (FPR2/ALX) agonists. In two mouse xenograft colorectal cancer models, NAP1051 significantly inhibited tumor growth when given orally at 4.8 to 5 mg/kg/day. Flow cytometric analyses showed that NAP1051 reduced splenic and intratumoral neutrophil and myeloid-derived suppressor cell populations, which correlated to the antitumor effect. In addition, NAP1051 reduced NETosis in the TME while stimulating T-cell recruitment. Overall, these results show that NAP1051 possesses key lipoxin-like properties and has antitumor activity against colorectal cancer via modulation of neutrophils and NETosis in the TME.

Mice carrying an epithelial deletion of the glucocorticoid receptor NR3C1 develop a higher tumor load in experimental colitis-associated cancer.

The glucocorticoid receptor NR3C1 is expressed in multiple cell types in the gut and elsewhere. Intestinal epithelial cells both produce and respond to glucocorticoids in different physiological and pathological contexts. In experimental colitis, glucocorticoids have been shown to exert a dual role, dampening inflammation while producing a deterioration in animal status, including death. Mice with tamoxifen-inducible, intestinal epithelial-specific deletion of NR3C1 (NR3C1ΔIEC mice) are protected against experimental colitis, suggesting glucocorticoid epithelial actions are deleterious. Since glucocorticoids modulate epithelial proliferation, it follows that they may affect the development of colon cancer. In this study, we set out to test this hypothesis using the dextran sulfate sodium-azoxymethane model of colitis-associated cancer. Knockout (KO) mice were found to exhibit a twofold higher tumor load but similar incidence and tumor size. Tumors had a higher trend to extend close to the submucosal layer (36% vs. 0%) in NR3C1ΔIEC mice, and overexpressed Lgr5, Egfr, and Myc, consistent with distinct expression of proliferative/stemness markers. Snai1 and Snai2 were upregulated specifically in tumors of NR3C1ΔIEC mice, suggesting enhanced epithelial to mesenchymal transition in the absence of the intestinal epithelial glucocorticoid (GC) receptor. We conclude that endogenous GC epithelial signaling is involved in colitis-associated cancer.NEW & NOTEWORTHY Mice carrying a tamoxifen-inducible deletion of the glucocorticoid receptor in intestinal epithelial cells (NR3C1ΔIEC mice) and their corresponding controls were subjected to the azoxymethane-dextran sulfate sodium model of colitis-associated cancer. KO mice exhibit a twofold higher tumor load, with a higher trend to extend close to the submucosal layer (36% vs. 0%), but with similar incidence and tumor size. Colonic tumors in NR3C1ΔIEC mice showed signs of increased neoplastic transformation and tumor-associated inflammation.

Characterization of Oral Squamous Cell Carcinoma Associated Inflammation: A Pilot Study.

Background: Oral squamous cell carcinoma (OSCC) is a devastating disease that is usually associated with a dense associated inflammatory infiltrate. Characterizing tumor-associated inflammation is critical to understand the pathogenies of tumor development and progression.Methods: We have tested a protocol to analyze tissue and salivary immune cells and mediators of 37 patients with OSCC at different stages and compared to eight chronic periodontitis patients and 24 healthy controls. Tissue analysis was based on fluorescent immunohistochemistry (FIHC) and inflammatory mediators were analyzed using a Luminex-based 30-Plex panel. Immune cells were analyzed using multichannel flow cytometry including CD45, CD66b, CD3, CD4, CD8, CD25, CD56, CD68, CD138, PD-1, and PD-L1.Results: We show an increase in OSCC-associated inflammation characterized by increased pro-inflammatory cytokines including IL-6, IL-8, TNFα, and GMCSF and increased salivary immune cells.Conclusion: We described a new method to analyze salivary inflammatory markers that can be used in future studies to monitor disease progression and prognosis.

Systemic Inflammation Associates With a Myeloid Inflamed Tumor Microenvironment in Primary Resected Colon Cancer—May Cold Tumors Simply Be Too Hot?

Systemic inflammation measured by the acute-phase protein CRP associates with poor outcome across cancer types. In contrast, local tumor-associated inflammation, primarily evaluated by T-lymphocytes, correlates with favorable prognosis. Yet, little is known whether these two responses are related or opposing processes and why elevated CRP in relation to cancer is detrimental for clinical outcome. As proof of concept, we developed a platform combining multiplexed IHC and digital imaging, enabling a virtual readout of both lymphoid and myeloid immune markers and their spatial patterns in the primary tumors of resected stage II and III colon cancer (CC) patients with and without accompanying systemic inflammation. Twenty-one patients with elevated CRP (>30 mg/l) and 15 patients with low CRP (<10 mg/l) were included in the analyses. Whole slides from the primary tumors were stained for markers of adaptive (CD8+, CD4+, foxp3 regulatory T cells, CD20+ B cells) and innate (CD68+ macrophages, CD66b+ neutrophils) immunity and the immune checkpoint molecule PD-L1. Associations between individual immune markers, preoperative CRP values, mismatch repair status (MMR), and risk of recurrence or death were assessed. Unsupervised hierarchical clustering was used to explore whether distinct immune phenotypes were present. Tumors from systemically inflamed patients (CRP >30 mg/l) displayed significantly more myeloid features in terms of higher densities of CD66b+neutrophils (p = 0.001) and CD68+macrophages (p = 0.04) and less lymphoid features (lower CD8 T cell, p = 0.03, and foxp3 regulatory T cell densities, p = 0.03) regardless of MMR status. Additionally, systemically inflamed patients harbored lower mean distances between neutrophils and tumor cells within the TME. Intriguingly, microsatellite instable (MSI) tumor status correlated with systemic inflammation. However, using a combinatorial approach, we found that regardless of an adaptive composite score (compounded CD4+ and CD8+ T cells), a high innate score (CD66b+ neutrophils and CD68+ macrophages) associated significantly with elevated CRP. In conclusion, tumor-associated systemic inflammation correlated with a myeloid-dominated TME in a small cohort of resectable CC patients. Our data highlight the importance of a comprehensive immune classification of tumors including players of innate immunity and support a role for CRP as an informative biomarker of the immune response taking place at the tumor site.

Abstract 1436: Mechanistic investigation of NAP1051, a lipoxin A4 biomimetic, in treating colorectal cancer

Abstract Purpose: Resolving tumor-associated inflammation in the tumor microenvironment (TME) can restore the immune response against malignant tissue. Lipoxin A4 (LXA4) is a short-lived endogenous bioactive lipid with potent anti-inflammatory and pro-resolving properties. We developed a LXA4 biomimetic, NAP1051, with increased stability and longer half-life, and demonstrated its properties using in vitro assays and in vivo xenograft tumor models and explored the underlying mechanism of action (MoA). Methods: Differentiated HL-60 and THP-1 induced by DMSO and PMA, respectively, were used as models. dHL-60 was used to determine the effect of NAP1051 on fMLP-induced neutrophil chemotaxis. NAP1051-induced dTHP-1 efferocytosis of apoptotic dHL-60 was measured using fluorescent microscopy. Concentration escalation and time of NAP1051 exposure were used to probe the molecular mechanism using Western Blot and RT-PCR. The efficacy of oral NAP1051 was evaluated in CT26 (CRC) xenograft model established in immunocompetent Balb/c mice with a dosage escalation design. Results: NAP1051 inhibited neutrophil chemotaxis towards fMLP by &amp;gt; 40% at 1, 10 and 100 nM (p &amp;lt; 0.05). NAP1051 dose-dependently promoted dTHP-1 efferocytosis (p &amp;lt; 0.05) and was equipotent to ATLA4. In dTHP-1 cells, NAP1051 induced strong phosphorylation on ERK1/2 and AKT from 10 nM to 1 µM. When compared to ATLA4 and W-peptide, NAP1051 caused strong phosphorylation at both S473 and T308 of AKT. The NAP1051-induced p-ERK1/2 and p-AKT were in parallel and in a dose-dependent and time-dependent way. MoA studies revealed that such p-ERK1/2 was mediated by MEK1/2. However, NAP1051 led to p-AKT at both S473 and T308 despite PI3K inhibition, indicating a PI3K-independent pathway was involved. In the mouse xenograft CRC model, we demonstrated that NAP1051 significantly inhibit tumor growth when given p.o. at 5 mg/kg/day. Flow cytometry on splenic cells showed that NAP1051 reduced splenic neutrophil and MDSC populations, which correlated to the tumor sizes. IHC analyses revealed that NAP1051 decreased the intratumoral Ly6G+ neutrophils most significantly at 5 mg/kg/day (p&amp;lt;0.1). In combination with low-dose 5-FU and CTX, NAP1051 significantly decreased splenic neutrophils and MDSCs compared to chemotherapies alone (p&amp;lt;0.05). Conclusions: NAP1051 has LXA4-like activity including inhibiting fMLP-mediated neutrophil chemotaxis and promoting macrophage efferocytosis of apoptotic cells. The molecular MoA of NAP1051 involves ERK1/2 and AKT signaling pathways which are interrelated closely. A PI3K-independent pathway may be activated and resulted in AKT activation. NAP1051 inhibited tumor growth significantly at 5 mg/kg/day in a CRC model with significant changes in splenic and intratumoral immune cell populations. With these properties, NAP1051 may be an effective component in the treatment of CRCs by modulating the inflammatory immune cells in the TME. Citation Format: Tiange Dong, Priyal Dave, Brandon Ebright, Kabir Ahluwalia, Eugene Zhou, Isaac Asante, Malika Salimova, Hua Pei, Tracey Lin, Andrew Mead, Zeyang Li, Nicos Petasis, Stan Louie. Mechanistic investigation of NAP1051, a lipoxin A4 biomimetic, in treating colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1436.

Abstract 1766: Triggering the resolution of inflammation with agonistic anti-ChemR23 antibody dampens inflammation-driven carcinogenesis

Abstract Chronic inflammation is associated with abnormal non-phlogistic clearance (efferocytosis) of apoptotic cells by macrophages and a defect of the resolution of inflammation pathways. The resolution of inflammation is an active immunological process mediated by specialized pro-resolving mediator (SPM) which target specific resolutive G-protein coupled receptors expressed by different immune cells and participate to the tissue homeostasis return after an injury. Defects in the clearance of (chemotherapy-induced) apoptotic tumor cell debris strengthens inflammation and has been associated with exacerbated tumor growth in several preclinical models. Proresolutive therapeutic approaches, such as using exogenous resolvin E1 (RvE1), the natural lipidic proresolutive ligand of the GPCR ChemR23, have been shown to dampen tumor-associated inflammation and to reduce tumor growth. Using single-cell RNA sequencing analysis, we found that ChemR23 is mainly expressed by tumor-associated macrophages in melanoma and lung cancers. Moreover, ChemR23 expression was barely expressed in non-inflamed tissues indicating a preferential expression on the inflamed or tumor site. We screened and identified an anti-ChemR23 mAb which induces RvE1-like Akt and ERK signaling in mouse and human macrophages and favors macrophage polarization towards a pro-resolutive phenotype. In vitro, the agonist antibody significantly increased the phagocytosis of apoptotic tumor primary mesothelioma cells by human tumor-polarized macrophages. In vivo, the agonist ChemR23 mAb accelerates the resolution of inflammation in an acute inflammatory model, as illustrated by a significant decrease of inflammatory macrophages and neutrophils infiltrates as compared to isotype control groups both in mice and non-human primate models. Similarly, ChemR23 triggering with the anti-ChemR23 mAb improved weight recovery, reduced diarrhea and decreased the development of colon neoplastic foci in a chronic colitis model coupled with the injection of a carcinogen agent. Furthermore, the administration of the anti-ChemR23 mAb as a monotherapy displayed some partial and complete antitumor responses in immunocompetent mouse models of subcutaneous colon carcinoma (MC38 and CT26) as well as orthotopic mesothelioma (AK7). Finally, using an orthotopic triple-negative breast cancer model (4T1), while we observed a limited impact on primary tumor growth, spontaneous metastasis development in the lung was significantly inhibited by the ChemR23 agonist mAb monotherapy. Our study reveals for the first time the therapeutic potential of triggering the proresolutive pathways using an anti-ChemR23 agonistic mAb to limit chronic inflammation in the tumor microenvironment and inhibit metastasis development. Citation Format: Vanessa Gauttier, Margot Lavy, Charlène Trilleaud, Kévin Biteau, Isabelle Girault, Lyssia Belarif, Géraldine Teppaz, Caroline Mary, Virginie Thépénier, Christophe Blanquart, Sophie Barillé-Nion, Nicolas Poirier. Triggering the resolution of inflammation with agonistic anti-ChemR23 antibody dampens inflammation-driven carcinogenesis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1766.

Experimental Drugs for Chemotherapy- and Cancer-Related Anemia

Anemia in cancer patients is a relevant condition complicating the course of the neoplastic disease. Overall, we distinguish the anemia which arises under chemotherapy as pure adverse event of the toxic effects of the drugs used, and the anemia induced by the tumour-associated inflammation, oxidative stress, and systemic metabolic changes, which can be worsened by the concomitant anticancer treatments. This more properly cancer-related anemia depends on several overlapping mechanism, including impaired erythropoiesis and functional iron deficiency, which make its treatment more difficult. Standard therapies approved and recommended for cancer anemia, as erythropoiesis-stimulating agents and intravenous iron administration, are limited to the treatment of chemotherapy-induced anemia, preferably in patients with advanced disease, in view of the still unclear effect of erythropoiesis-stimulating agents on tumour progression and survival. Outside the use of chemotherapy, there are no recommendations for the treatment of cancer-related anemia. For a more complete approach, it is fundamentally a careful evaluation of the type of anemia and iron homeostasis, markers of inflammation and changes in energy metabolism. In this way, anemia management in cancer patient would permit a tailored approach that could give major benefits. Experimental drugs targeting hepcidin and activin II receptor pathways are raising great expectations, and future clinical trials will confirm their role as remedies for cancer-related anemia. Recent evidence on the effect of integrated managements, including nutritional support, antioxidants and anti-inflammatory substances, for the treatment of cancer anemia are emerging. In this review article, we show standard, innovative, and experimental treatment used as remedy for anemia in cancer patients.

The zinc finger protein Miz1 suppresses liver tumorigenesis by restricting hepatocyte-driven macrophage activation and inflammation

Chronic inflammation plays a central role in hepatocellular carcinoma (HCC), but the contribution of hepatocytes to tumor-associated inflammation is not clear. Here, we report that the zinc finger transcription factor Miz1 restricted hepatocyte-driven inflammation to suppress HCC, independently of its transcriptional activity. Miz1 was downregulated in HCC mouse models and a substantial fraction of HCC patients. Hepatocyte-specific Miz1 deletion in mice generated a distinct sub-group of hepatocytes that produced pro-inflammatory cytokines and chemokines, which skewed the polarization of the tumor-infiltrating macrophages toward pro-inflammatory phenotypes to promote HCC. Mechanistically, Miz1 sequestrated the oncoprotein metadherin (MTDH), preventing MTDH from promoting transcription factor nuclear factor κB (NF-κB) activation. A distinct sub-group of pro-inflammatory cytokine-producing hepatocytes was also seen in a subset of HCC patients. In addition, Miz1 expression inversely correated with disease recurrence and poor prognosis in HCC patients. Our findings identify Miz1 as a tumor suppressor that prevents hepatocytes from driving inflammation in HCC.

Dysregulation of tumour microenvironment driven by circ-TPGS2/miR-7/TRAF6/NF-κB axis facilitates breast cancer cell motility

Tumour microenvironment (TME) is frequently remodelled and deregulated in cancer development and progression. The underlying mechanisms are complex, multifactorial and largely unknown. Circular RNA (circRNA) is an endogenous RNA with a covalently closed loop that plays critical roles in the pathological and physiological processes of the organism. Here, we identified a TME-associated circRNA, circ-TPGS2, which promoted breast cancer (BC) cell dissemination via altering TME. High circ-TPGS2 was observed in metastatic BC tissues and cell lines in comparison to respective normal controls, which was linked to poor overall and recurrence-free survival. Overexpression of circ-TPGS2 notably promoted cell migration, while silencing of circ-TPGS2 resulted in an opposite trend. Moreover, circ-TPGS2 increased pro-inflammatory chemokine production and evoked tumour-associated inflammation by recruiting neutrophils via autocrine and paracrine manners. In terms of mechanism, circ-TPGS2 acted as a sponge of miR-7 and elevated TRAF6, leading to p65 phosphorylation and nuclear translocation, ultimately activating NF-κB signalling. In addition, p65 was abundantly occupied on circ-TPGS2 promoter, activating circ-TPGS2 transcription, thus, forming a positive feedback loop that amplified the pro-metastasis effect of circ-TPGS2. Taken together, our data for the first time reveal the biological implication of circ-TPGS2 in BC, it triggers TME reshaping that facilitates BC metastasis through the miR-7/TRAF6/NF-κB signalling cascade.

GPR30 knockdown weakens the capacity of CAF in promoting prostate cancer cell invasion via reducing macrophage infiltration and M2 polarization.

Cancer-associated fibroblasts (CAFs) can promote the development and metastasis of prostate cancerpartly by mediating tumor-associated inflammation. An increasing amount of studies have focused on the functional interactions between CAFs and immune cells in the tumor microenvironment (TME). We previously reported that G protein-coupled receptor 30 (GPR30) was highly expressed in prostate CAFs and plays a crucial rolein prostate stromal cell activation. However, the effect and underlying mechanism of GPR30 expression in prostate CAFs affecting the interaction between CAFs and tumor-associated macrophages (TAMs) need further elucidation. Here, we found that, compared with CAF-shControl, CAF-shGPR30 inhibited macrophagemigration through transwell migration assays, which should be attributed to the decreased expression of C-X-C motif chemokine ligand 12 (CXCL12). In addition, macrophages treated with a culture medium of CAF-shGPR30 exhibited attenuated M2 polarization with downregulated M2-like markers expression. Moreover, macrophages stimulated with a culture medium of CAF-shGPR30 were less efficient in promoting activation of fibroblast cells and invasion of PCa cells. Finally, cocultured CAF-shGPR30 and macrophages suppressed PCa cell invasion compared to cocultured CAF-shControl and macrophages by decreasing interleukin-6 (IL-6) secretion, and this effect could be abrogated with rescue expression of IL-6. Our results pinpoint the function of GPR30 in prostate CAFs on regulating the CAF-TAM interaction in the TME and provide new insights into PCa therapies via regulating TME.

Screening of immunosuppressive cells from colorectal adenocarcinoma and identification of prognostic markers.

Background: Colorectal cancer (CRC) is the most common type of gastrointestinal malignant tumour. Colorectal adenocarcinoma (COAD) – the most common type of CRC – is particularly dangerous. The role of the immune system in the development of tumour-associated inflammation and cancer has received increasing attention recently.Methods: In the present study, we compiled the expression profiles of 262 patients with complete follow-up data from The Cancer Genome Atlas (TCGA) database as an experimental group and selected 65 samples from the Gene Expression Omnibus (GEO) dataset (of which 46 samples were with M0) as a verification group. First, we screened the immune T helper 17 (Th17) cells related to the prognosis of COAD. Subsequently, we identified Th17 cells-related hub genes by utilising Weighted Gene Co-expression Network Analysis (WGCNA) and Least Absolute Shrinkage and Selector Operation (LASSO) regression analysis. Six genes associated with the prognosis in patients with COAD were identified, including: KRT23, ULBP2, ASRGL1, SERPINA1, SCIN, and SLC28A2. We constructed a clinical prediction model and analysed its predictive power.Results: The identified hub genes are involved in developing many diseases and closely linked to digestive disorders. Our results suggested that the hub genes could influence the prognosis of COAD by regulating Th17 cells’ infiltration.Conclusions: These newly discovered hub genes contribute to clarifying the mechanisms of COAD development and metastasis. Given that they promote COAD development, they may become new therapeutic targets and biomarkers of COAD.

Tristetraprolin expression by keratinocytes protects against skin carcinogenesis.

Cancer is caused primarily by genomic alterations resulting in deregulation of gene regulatory circuits in key growth, apoptosis, or DNA repair pathways. Multiple genes associated with the initiation and development of tumors are also regulated at the level of mRNA decay, through the recruitment of RNA-binding proteins to AU-rich elements (AREs) located in their 3′-untranslated regions. One of these ARE-binding proteins, tristetraprolin (TTP; encoded by Zfp36), is consistently dysregulated in many human malignancies. Herein, using regulated overexpression or conditional ablation in the context of cutaneous chemical carcinogenesis, we show that TTP represents a critical regulator of skin tumorigenesis. We provide evidence that TTP controlled both tumor-associated inflammation and key oncogenic pathways in neoplastic epidermal cells. We identify Areg as a direct target of TTP in keratinocytes and show that EGFR signaling potentially contributed to exacerbated tumor formation. Finally, single-cell RNA-Seq analysis indicated that ZFP36 was downregulated in human malignant keratinocytes. We conclude that TTP expression by epidermal cells played a major role in the control of skin tumorigenesis.