LIF regulates CXCL9 in tumor-associated macrophages and prevents CD8+ T cell tumor-infiltration impairing anti-PD1 therapy

Autophagy inhibition amplifies anti-tumor immunity effect of dinutuximab beta on neuroblastoma via the VEGFR/AKT/mTOR and ROS/NF-κB pathways

Dinutuximab beta has shown limited efficacy in treating high-risk neuroblastoma (NB). Combining autophagy inhibitors with immune checkpoint inhibitors (ICIs) has proven effective in many malignancies. However, the anti-tumor effects of autophagy inhibition in conjunction with anti-GD2 immunotherapy remain unknown. In this study, dinutuximab beta induces anti-proliferation and anti-EMT activity in NB cells. Dinutuximab beta also triggers autophagy in NB cells, and inhibition of the VEGFR pathway with anlotinib amplifies dinutuximab beta-induced autophagy. In addition, dinutuximab beta induces the synthesis of the chemokine CXCL9 and the infiltration of CD8+ T cells. Mechanistically, dinutuximab beta inhibits the VEGFR/AKT/mTOR and ROS/NF-κB pathways. Furthermore, autophagy inhibition by CQ enhances CXCL9 expression and anti-tumor T cell responses of single anti-GD2 therapy in vitro and in vivo. Collectively, this study suggests autophagy inhibitors may be a promising strategy for enhancing therapeutic efficacy in NB in conjunction with anti-GD2 immunotherapy.

Blocking LIF and PD-L1 enhances the antitumor efficacy of SBRT in murine PDAC models

BACKGROUND

Recent preclinical and clinical data suggest that leukemia inhibitory factor (LIF) is a potential target for various tumor types including pancreatic ductal adenocarcinoma as LIF is involved in multiple protumor processes including cancer stem cell maintenance, epithelial-mesenchymal transition (EMT), immunosuppression, and chemo/radioresistance. Anti-LIF antibody therapy has demonstrated safety and tolerability but limited efficacy in phase 1 clinical trial in advanced solid tumors. This prompted us to explore combination therapies, suggesting that LIF blockade, when combined with standard-of-care chemotherapy, radiotherapy, and/or immunotherapy, could present a promising therapeutic strategy.

METHODS

We evaluated the impact of combining systemic inhibition of LIF/programmed death-ligand 1 (PD-L1) with localized stereotactic body radiotherapy (SBRT) on tumor progression across multiple murine orthotopic pancreatic tumor models and examined systemic antitumor immunity using a hepatic rechallenge model. The antitumor immune response was characterized throughflow cytometry and Luminex assays. To identify differentially expressed genes and signaling pathways following treatment, we performed bulk RNA sequencing on pancreatic tumors. Additionally, single-cell RNA sequencing was conducted to further examine changes in tumor-infiltrating immune cells and their signaling pathways.

RESULTS

We showed that simultaneous inhibition of LIF and PD-L1 significantly amplified the antitumor efficacy of SBRT, resulting in extended survival. The triple therapy (SBRT+anti-LIF+anti-PD-L1) generated an immunostimulatory tumor microenvironment, characterized by a proinflammatory shift in the cytokine/chemokine profile, increased infiltration of effector CD8+ T cells, and upregulated activation or maturation signals in tumor-infiltrating CD8+ T cells and macrophages. The beneficial effects of triple therapy were mostly abrogated by depletion of CD8+ T cells. In addition, triple therapy downregulated pathways related to tumor stemness, proliferation, and metabolism, and reduced EMT. Importantly, the combination of local SBRT treatment with systemic LIF and PD-L1 blockade resulted in long-term systemic antitumor memory.

Snord67 promotes breast cancer metastasis by guiding U6 modification and modulating the splicing landscape

Previously considered "housekeeping" genes, small nucleolar RNAs (snoRNAs) are increasingly understood to have wide-ranging functions in cancer, yet their role in metastasis has been less well studied. Here, we identify the snoRNA Snord67 as a regulator of lymph node (LN) metastasis in breast cancer. Snord67 expression is enriched in LN metastases in an immune-competent mouse model of female breast cancer. In an orthotopic breast cancer model, loss of Snord67 decreases LN metastasis. In a model of lymphatic metastasis, Snord67 loss decreases LN tumor growth and distant metastases. In breast cancer cell lines, Snord67 knockout results in loss of targeted 2'-O-methylation on U6 small nuclear RNA, as well as widespread changes in splicing. Together, these results demonstrate that Snord67 regulates splicing and promotes the growth of LN metastases and subsequent spread to distant metastases. SnoRNA-guided modifications of the spliceosome and regulation of splicing may represent a potentially targetable pathway in cancer.

Discovering potential therapeutic targets in glioblastoma multiforme using a multi-omics approach

BACKGROUND

Glioblastoma multiforme (GBM) is a highly aggressive primary brain tumor associated with high fatality rates, poor prognosis, and limited treatment options. In this study, we utilized RNA-Seq gene count data from GBM patients, sourced from the Gene Expression Omnibus (GEO) database, to conduct an in-depth analysis of gene expression patterns.

METHODS

Our investigation involved stratifying samples into two distinct sets, Group I and Group II, comparing normal, low-grade, and GBM tumor samples, respectively. Subsequently, we performed differential expression analysis and enrichment analysis to uncover significant gene signatures. To elucidate the protein-protein interactions associated with GBM, we used the STRING plugin within Cytoscape for comprehensive network visualization and analysis.

RESULTS

By applying Maximal clique centrality (MCC) scores, we identified a set of 10 hub genes in each group. These hub genes were subjected to survival analysis, highlighting their prognostic relevance. In Group I, comprising BUB1, DLGAP5, BUB1B, CDK1, TOP2A, CDC20, KIF20A, ASPM, BIRC5, and CCNB2, these genes emerged as potential biomarkers associated with the transition to low-grade tumors. In Group II, genes such as LIF, LBP, CSF3, IL6, CCL2, SAA1, CCL20, MMP9, CXCL10, and MMP1 were found to be involved in the transformation to adult glioblastoma. Kaplan-Meier's overall survival analysis of these hub genes revealed that modifications, particularly the upregulation of these candidate genes, were associated with reduced survival in GBM patients.

CONCLUSIONS

The findings established the significance of genomic alterations and differential gene expression in GBM, presenting opportunities for prognostic and targeted therapeutic interventions. This study provides valuable insights into potential avenues for enhancing the clinical management of GBM.

CXCL9 and CXCL13 shape endometrial cancer immune-activated microenvironment via tertiary lymphoid structure formation

Immune checkpoint inhibitor (ICI) therapy has been successfully applied to various cancers; however, not all patients respond to ICI therapy. Tumors with an immune-activated environment are highly responsive to ICIs. To identify the cells and molecules essential to the formation of an immune-activated cancer microenvironment, we focused on the tertiary lymphoid structure (TLS) and performed histological and genomic analyses using endometrial cancer material. In the high immunogenic group, numerous TLSs were observed, and CXCL9 and CXCL13 expression was markedly increased. CXCL9-positive antigen-presenting and CXCL13-positive follicular dendritic cells were distributed in the T- and B-cell zones of TLSs, respectively. A group of molecules whose expression was upregulated along with CXCL9 and CXCL13 expression was strongly associated with cellular immunity. These results suggest that CXCL9-expressing antigen-presenting cells and CXCL13-expressing follicular dendritic cells coordinately shape the immune-activated microenvironment through TLS formation. The current findings will contribute to a better understanding of the mechanisms underlying the activated cancer immune microenvironment, thereby advancing the field of precision cancer medicine.

Parabacteroides distasonis promotes CXCL9 secretion of tumor-associated macrophages and enhances CD8+T cell activity to trigger anti-tumor immunity against anti-PD-1 treatment in non-small cell lung cancer mice

BACKGROUND

Parabacteroides distasonis (P. distasonis) could regulate inflammatory markers, promote intestinal barrier integrity, and block tumor formation in colon. However, the regulatory effect of P. distasonis on non-small cell lung cancer (NSCLC) remains unknown. This study aimed to investigate the regulatory effect of P. distasonis on NSCLC and its impact on tumor immunity.

METHODS

We first established a mouse model of Lewis lung cancer, and administered P. distasonis and intrabitoneal injection of anti-mouse PD-1 monoclonal antibody to assess the impact of P. distasonis on tumor immunity, and mouse intestinal barrier. Then, we explored the effect of P. distasonis on CD8+T cells and CXCL9 secretion mediated by tumor-associated macrophages (TAM). We used the TLR1/2 complex inhibitor CPT22 to evaluate its effect on macrophage activation. Finally, we explored the effect of P. distasonis on CD8+T cells and CXCL9 secreted by TAM in vivo.

RESULTS

In vivo, P. distasonis enhanced anti-tumor effects of anti-PD-1 in NSCLC mice, improved intestinal barrier integrity, recruited macrophages, and promoted M1 polarization. In vitro, CD86 and iNOS levels in BMDM were elevated and CD206 and Arg1 levels were suppressed in membrane fraction of P. distasonis (PdMb) group in comparison to Control group. With additional CPT22 pre-treatment, the levels of CD86 and iNOS in BMDM were reduced, and the levels of CD206 and Arg1 were increased. Compared to PBS group, P. distasonis group exhibited higher proportion of CD8+T cells in tumor tissues, along with increased positive proportion of GZMB and IFN-γ in CD8+T cells. Additionally, in comparison to Control group, PdMb group showed an elevated proportion of GZMB+T and IFN-γ+T cells within CD8+T cells, and secretion of IFN-γ, TNF-α, perforin, and GZMB in CD8+T cell supernatant increased. Moreover, the proportion of CXCL9+F4/80+ macrophages in tumor tissues was higher in P. distasonis group compared to PBS group. In comparison to Control group, CXCL9 protein level in BMDM and CXCL9 secretion level in BMDM supernatant were increased in PdMb group. Finally, P. distasonis enhanced CD8+T cell activity by secreting CXCL9 from macrophages in vivo.

CONCLUSIONS

P. distasonis promoted CXCL9 secretion of TAM and enhanced CD8+T cell activity to trigger anti-tumor immunity against anti-PD-1 treatment in NSCLC mice.

Assessment of lncRNA biomarkers based on NETs for prognosis and therapeutic response in ovarian cancer

Ovarian cancer (OC) usually progresses rapidly and is associated with high mortality, while a reliable clinical factor for OC patients to predict prognosis is currently lacking. Recently, the pathogenic role of neutrophils releasing neutrophil extracellular traps (NETs) in various cancers including OC has gradually been recognized. The study objective was to determine whether NETs-related biomarkers can be used to accurately predict the prognosis and guide clinical decision-making in OC. In this study, we utilized univariate and multivariate Cox regression to identify key prognostic features and developed a model with six NETs-related lncRNAs, selected via LASSO regression. The model's predictive capability was assessed through Kaplan-Meier, ROC, and Cox analyses. To understand the model's mechanisms, we conducted GO term analysis, KEGG pathway enrichment, and GSEA. We also analyzed gene mutation status, tumor mutation load, survival rates, and model correlation. Additionally, we compared immune functions, immune checkpoint expression, and chemotherapy sensitivity between risk groups. Besides, we validated the model's predictive value using test data and tissues acquired from our institution. Finally, we performed in vitro and in vivo experiments to confirm the expression of model lncRNAs and the cellular level function of GAS5. We developed a model using six NETs-associated lncRNAs: GAS5, GBP1P1, LINC00702, LINC01933, LINC02362, and ZNF687-AS1. The model's predictive performance, evaluated via ROC curve, was compared with traditional clinicopathological features. GO process analysis highlighted molecular functions related to antigen binding and immune system biological processes. Variations were observed in transcription regulators affecting immune response, inflammation, cytotoxicity, and regulation. We also predicted IC50 values for chemotherapeutic drugs (bexarotene, bicalutamide, embelin, GDC0941, and thapsigargin) in high- and low-risk groups, finding higher IC50 values in low-risk patients. The risk model's robustness was validated using OC cells, tissues, and clinical datas.

Immune-parenchymal multicellular niches are shared across distinct thyroid autoimmune diseases

Thyroid hormone, produced in the thyroid gland, regulates metabolism, development, and cardiac function. The thyroid is susceptible to autoimmune attack by both cellular and humoral immunity exemplified by Hashimoto's thyroiditis (HT) and Graves' Disease (GD), respectively. In HT, immune-mediated destruction impairs thyroid hormone production, while in GD, stimulating autoantibodies promote over-production. Here, we generated a multi-modal atlas of 604,076 human thyroid and blood cells from HT, GD, and control patients. We found that, despite markedly different clinical presentations and distinct antigenic triggers, HT and GD exhibit convergent cellular dynamics resulting in a shared continuum of immune infiltration. Along this continuum, a key feature is a thyrocyte niche containing CD8 + T cells that may segregate pathogenic T cells from regions with preserved thyroid hormone production. These findings of a shared disease continuum characterized by spatially defined immune niches provide a new framework for understanding tissue homeostasis in human autoimmune disease.

Enhancing T-Cell Infiltration and Immunity in Solid Tumors via DNA Nanolinker-Mediated Monocyte Hitchhiking

Cytotoxic CD8+ T cells are one of the most powerful effectors in the antitumor immune response. However, their insufficient tumor infiltration severely limits the clinical success of immunotherapy in solid tumors. In this work, by using amphiphilic aptamer-incorporated DNA tetrahedra (aptTDN) as the intercellular nanolinker, we developed a monocyte-hitchhiked T-cell delivery strategy to actively promote the intratumoral infiltration of effector CD8+ T cells. Our results demonstrated that membrane-anchoring of aptTDN enabled the specific and stable ligation of T cells with Ly6c+ monocytes, without compromising the migratory behavior of monocytes and the antitumor activity of T cells. By leveraging the intrinsic tumor-homing capability of monocytes, the ligated T cells efficiently accumulated within tumor-associated vasculature and then deeply infiltrated the tumor bed. Additionally, the enhanced intratumoral presence of adoptively transferred effector CD8+ T cells facilitated the establishment of an immunosupportive microenvironment, that further recruited endogenous T cells and ultimately bolstered antitumor immunity. Moreover, our monocyte-hitchhiked T-cell tumor infiltration system could significantly improve the efficacy of immune checkpoint blockade therapy. Collectively, by utilizing chemically synthetic nanolinkers to modulate cellular interactions and develop a delivery system of therapeutic cells, our work presents a new paradigm for the advancement of immunotherapy against solid tumors.

Prostate Cancer: De-regulated Circular RNAs With Efficacy in Preclinical In Vivo Models

Therapy resistance, including castration-resistance and metastasis, remains a major hurdle in the treatment of prostate cancer. In order to identify novel therapeutic targets and treatment modalities for prostate cancer, we conducted a comprehensive literature search on PubMed to identify de-regulated circular RNAs that influence treatment efficacy in preclinical prostate cancer-related in vivo models. Our analysis identified 49 circular RNAs associated with various processes, including treatment resistance, transmembrane and secreted proteins, transcription factors, signaling cascades, human antigen R, nuclear receptor binding, ubiquitination, metabolism, epigenetics and other target categories. The identified targets and circular RNAs can be further scrutinized through target validation approaches. Down-regulated circular RNAs are candidates for reconstitution therapy, while up-regulated RNAs can be inhibited using small interfering RNA (siRNA), antisense oligonucleotides (ASO) or clustered regularly interspaced short palindromic repeats/CRISPR associated (CRISPR-CAS)-related approaches.

Blockade of LIF and PD-L1 Enhances Chemotherapy in Preclinical PDAC Models

Background/Objectives: Pancreatic ductal adenocarcinoma (PDAC), expecting to be the second leading cause of cancer deaths by 2030, resists immune checkpoint therapies due to its immunosuppressive tumor microenvironment (TME). Leukemia inhibitory factor (LIF) is a key target in PDAC, promoting stemness, epithelial-mesenchymal transition (EMT), and therapy resistance. Phase 1 clinical trials showed anti-LIF therapy is safe but with limited efficacy, suggesting better outcomes when combined with chemotherapy, radiotherapy, or immunotherapy. Methods: We assessed the combination of chemotherapy (gemcitabine/nab-paclitaxel) and dual blockade of LIF and PD-L1 on tumor growth and survival in orthotopic and spontaneous PDAC models. Flow cytometry and scRNA-seq were utilized to monitor the antitumor immune response. The role of key immune cells was further confirmed by depleting these immune cells, including CD4, CD8, or inflammatory monocytes. Results: Sequential treatment with chemotherapy (gemcitabine/nab-paclitaxel) and dual blockade of LIF and PD-L1 significantly improved antitumor efficacy compared to monotherapy or dual combinations of these therapies. This chemo/anti-LIF/anti-PD-L1 approach reduced EMT in tumor cells and enhanced the antitumor immune response, primarily through CD8 T cells, as depleting CD8 cells largely abrogated the effect of treatment. This combination therapy also shifted macrophages and dendritic cells towards an antitumor phenotype. Conclusions: The combination of chemotherapy, anti-LIF, and anti-PD-L1 not only targeted tumor cells but also augmented the anti-tumor immune response. These findings strongly support advancing chemo/anti-LIF/anti-PD-L1 combination therapy to clinical trials in PDAC.

Biomaterials enhancing localized cancer therapy activated anti-tumor immunity: a review

Localized cancer therapies such as radiotherapy, phototherapy, and chemotherapy are precise cancer treatment strategies aimed at minimizing systemic side effects. However, cancer metastasis remains the primary cause of mortality among cancer patients in clinical settings, and localized cancer treatments have limited efficacy against metastatic cancer. Therefore, researchers are exploring strategies that combine localized therapy with immunotherapy to activate robust anti-tumor immune responses, thereby eradicating metastatic cancer. Biomaterials, as novel materials, exhibit great potential in biomedical applications and have achieved great progress in clinic translation. This review introduces biomaterials and their applications in research focused on enhancing localized cancer treatment activated anti-tumor immunity. Additionally, the current challenges and future directions of biomaterials are also discussed, providing insights and references for related research.

Targeting DTX2/UFD1-mediated FTO degradation to regulate antitumor immunity

Here, we show that vitamin E succinate (VES) acts as a degrader for the m6A RNA demethylase fat mass and obesity-associated protein (FTO), thus suppressing tumor growth and resistance to immunotherapy. FTO is ubiquitinated by its E3 ligase DTX2, followed by UFD1 recruitment and subsequent degradation in the proteasome. VES binds to FTO and DTX2, leading to enhanced FTO-DTX2 interaction, FTO ubiquitination, and degradation in FTO-dependent tumor cells. VES suppressed tumor growth and enhanced antitumor immunity and response to immunotherapy in vivo in mouse models. Genetic FTO knockdown or VES treatment increased m6A methylation in the LIF (Leukemia Inhibitory Factor) gene and decreased LIF mRNA decay, and thus sensitized melanoma cells to T cell-mediated cytotoxicity. Taken together, our findings reveal the underlying molecular mechanism for FTO protein degradation and identify a dietary degrader for FTO that inhibits tumor growth and overcomes immunotherapy resistance.

Discovery of miRNA-mRNA regulatory networks in glioblastoma reveals novel insights into tumor microenvironment remodeling

Adult glioblastoma (GBM) is a highly aggressive primary brain tumor, accounting for nearly half of all malignant brain tumors, with a median survival rate of only 8 months. Treatment for GBM is largely ineffective due to the highly invasive nature and complex tumor composition of this malignancy. MicroRNAs (miRNA) are short, non-coding RNAs that regulate gene expression by binding to messenger RNAs (mRNA). While specific miRNA have been associated with GBM, their precise roles in tumor development and progression remain unclear. In this study, the analysis of miRNA expression data from 743 adult GBM cases and 59 normal brain samples identified 94 downregulated miRNA and 115 upregulated miRNA. Many of these miRNA were previously linked to GBM pathology, confirming the robustness of our approach, while we also identified novel miRNA that may act as potential regulators in GBM. By integrating miRNA predictions with gene expression data, we were able to associate downregulated miRNA with tumor microenvironment factors, including extracellular matrix remodeling and signaling pathways involved in tumor initiation, while upregulated miRNA were found to be associated with essential neuronal processes. This analysis highlights the significance of miRNA in GBM and serves as a foundation for further investigation.

Cancer-associated fibroblasts shape early myeloid cell response to chemotherapy-induced immunogenic signals in next generation tumor organoid cultures

BACKGROUND

Patient-derived colorectal cancer (CRC) organoids (PDOs) solely consisting of malignant cells led to major advances in the understanding of cancer treatments. Yet, a major limitation is the absence of cells from the tumor microenvironment, thereby prohibiting potential investigation of treatment responses on immune and structural cells. Currently there are sparse reports describing the interaction of PDOs, cancer-associated fibroblasts (CAFs) and tumor-associated macrophages (TAMs) in complex primary co-culture assay systems.

METHODS

Primary PDOs and patient matched CAF cultures were generated from surgical resections. Co-culture systems of PDOs, CAFs and monocytic myeloid cells were set up to recapitulate features seen in patient tumors. Single-cell transcriptomics and flow cytometry was used to show effects of culture systems on TAM populations in the co-culture assays under chemotherapeutic and oncolytic viral treatment.

RESULTS

In contrast to co-cultures of tumor cells and monocytes, CAF/monocyte co-cultures and CAF/monocyte/tumor cell triple cultures resulted in a partial differentiation into macrophages and a phenotypic switch, characterized by the expression of major immunosuppressive markers comparable to TAMs in CRC. Oxaliplatin and 5-fluorouracil, the standard-of-care chemotherapy for CRC, induced polarization of macrophages to a pro-inflammatory phenotype comparable to the immunogenic effects of treatment with an oncolytic virus. Monitoring phagocytosis as a functional proxy to macrophage activation and subsequent onset of an immune response, revealed that chemotherapy-induced cell death, but not virus-mediated cell death, is necessary to induce phagocytosis of CRC cells. Moreover, CAFs enhanced the phagocytic activity in chemotherapy treated CRC triple cultures.

CONCLUSIONS

Primary CAF-containing triple cultures successfully model TAM-like phenotypes ex vivo and allow the assessment of their functional and phenotypic changes in response to treatments following a precision medicine approach.

CCL3 predicts exceptional response to TGFβ inhibition in basal-like pancreatic cancer enriched in LIF-producing macrophages

The TGFβ receptor inhibitor galunisertib showed promising efficacy in patients with pancreatic ductal adenocarcinoma (PDAC) in the phase 2 H9H-MC-JBAJ study. Identifying biomarkers for this treatment remains essential. Baseline plasma levels of chemokine CCL3 were integrated with clinical outcomes in PDAC patients treated with galunisertib plus gemcitabine (n = 104) or placebo plus gemcitabine (n = 52). High CCL3 was a poor prognostic factor in the placebo group (mOS 3.6 vs. 10.1 months; p < 0.01) but a positive predictor for galunisertib (mOS 9.2 vs. 3.6 months; p < 0.01). Mechanistically, tumor-derived CCL3 activates Tgfβ signaling in macrophages, inducing their M2 phenotype and Lif secretion, sustaining a mesenchymal/basal-like ecotype. TGFβ inhibition redirects macrophage polarization to M1, reducing Lif and shifting PDAC cells to a more epithelial/classical phenotype, improving gemcitabine sensitivity. This study supports exploring TGFβ-targeting agents in PDAC with a mesenchymal/basal-like ecotype driven by high CCL3 levels.

Super-Enhancer Driven LIF/LIFR-STAT3-SOX2 Regulatory Feedback Loop Promotes Cancer Stemness in Head and Neck Squamous Cell Carcinoma

Super-enhancers (SEs) have been recognized as key epigenetic regulators underlying cancer stemness and malignant traits by aberrant transcriptional control and promising therapeutic targets against human cancers. However, the SE landscape and their roles during head and neck squamous cell carcinoma (HNSCC) development especially in cancer stem cells (CSCs) maintenance remain underexplored yet. Here, we identify leukemia inhibitory factor (LIF)-SE as a representative oncogenic SE to activate LIF transcription in HNSCC. LIF secreted from cancer cells and cancer-associated fibroblasts promotes cancer stemness by driving SOX2 transcription in an autocrine/paracrine manner, respectively. Mechanistically, enhancer elements E1, 2, 4 within LIF-SE recruit SOX2/SMAD3/BRD4/EP300 to facilitate LIF transcription; LIF activates downstream LIFR-STAT3 signaling to drive SOX2 transcription, thus forming a previously unknown regulatory feedback loop (LIF-SE-LIF/LIFR-STAT3-SOX2) to maintain LIF overexpression and CSCs stemness. Clinically, increased LIF abundance in clinical samples correlate with malignant clinicopathological features and patient prognosis; higher LIF concentrations in presurgical plasma dramatically diminish following cancer eradication. Therapeutically, pharmacological targeting LIF-SE-LIF/LIFR-STAT3 significantly impairs tumor growth and reduces CSC subpopulations in xenograft and PDX models. Our findings reveal a hitherto uncharacterized LIF-SE-mediated auto-regulatory loop in regulating HNSCC stemness and highlight LIF as a novel noninvasive biomarker and potential therapeutic target for HNSCC.

A mechanistic PK/PD model of AZD0171 (anti-LIF) to support Phase II dose selection

AZD0171 (INN: Falbikitug) is being developed as a humanized monoclonal antibody (mAb), immunoglobulin G subclass 1 (IgG1), which binds specifically to the immunosuppressive human cytokine leukemia inhibitory factor (LIF) and inhibits downstream signaling by blocking recruitment of glycoprotein 130 (gp130) to the LIF receptor (LIFR) subunit (gp190) and the phosphorylation of signal transducer and activator of transcription 3 (STAT3) and is intended to treat adult participants with advanced solid tumors. LIF is a pleiotropic cytokine (and a member of the IL-6 family of cytokines) involved in many physiological and pathological processes and is highly expressed in a subset of solid tumors, including non-small cell lung cancer (NSCLC), colon, ovarian, prostate, and pancreatic cancer. The aim of this work was to develop a mechanistic PK/PD model to investigate the effect of AZD0171 on tumor LIF levels, predict the level of downstream signaling complex (LIF:LIFR:gp130) inhibition, and examine the dose-response relationship to support dose selection for a Phase II clinical study. Modeling results show that tumor LIF is inhibited in a dose-dependent manner with >90% inhibition for 95% of patients at the Phase II clinical dose of 1500 mg Q2W.

Cancer cell - Fibroblast crosstalk via HB-EGF, EGFR, and MAPK signaling promotes the expression of macrophage chemo-attractants in squamous cell carcinoma

Interactions between cells in the tumor microenvironment (TME) shape cancer progression and patient prognosis. To gain insights into how the TME influences cancer outcomes, we derive gene expression signatures indicative of signaling between stromal fibroblasts and cancer cells, and demonstrate their prognostic significance in multiple and independent squamous cell carcinoma cohorts. By leveraging information within the signatures, we discover that the HB-EGF/EGFR/MAPK axis represents a hub of tumor-stroma crosstalk, promoting the expression of CSF2 and LIF and favoring the recruitment of macrophages. Together, these analyses demonstrate the utility of our approach for interrogating the extent and consequences of TME crosstalk.

The Road Ahead in Pancreatic Cancer: Emerging Trends and Therapeutic Prospects

This review explores the challenges and emerging trends in pancreatic cancer therapy. In particular, we focus on the tumor microenvironment and the potential of immunotherapy for pancreatic cancer. Pancreatic ductal adenocarcinoma, characterized by its dense stromal architecture, presents unique challenges for effective treatment. Recent advancements have emphasized the role of the tumor microenvironment in therapeutic resistance and disease progression. We discuss novel strategies targeting the desmoplastic barrier and immunosuppressive cells to enhance immune cell infiltration and activation. Recent clinical trials, particularly those involving novel immunotherapeutic agents and tumor vaccines, are examined to understand their efficacy and limitations. Our analysis reveals that combining immunotherapy with chemotherapy, radiation therapy, or drugs targeting epigenetic processes shows promise, improving overall survival rates and response to treatment. For instance, trials utilizing checkpoint inhibitors in combination with standard chemotherapies have extended disease-free survival by up to 6 months compared to chemotherapy alone. Importantly, vaccines targeting specific tumor neoantigens have shown the potential to increase patient survival. However, these approaches also face significant challenges, including overcoming the immunosuppressive tumor microenvironment and enhancing the delivery and efficacy of therapeutic agents. By providing an overview of both the promising results and the obstacles encountered, this review aims to highlight ongoing efforts to refine immunotherapy approaches for better patient outcomes.

Impact of anti leukemia inhibitory factor antibody on immune related gene expression in breast cancer Balb/c mouse model

Leukemia inhibitory factor (LIF) is involved in the progression of different cancers. In this study, we investigated the effect of anti-LIF antibodies on immune-related gene expression in the Balb/c mouse model of breast cancer. To immunize mice against LIF, recombinant LIF with Freund adjuvant was injected into the test group, whereas the control group received phosphate-buffered saline with adjuvant. Tumor induction (4T1 cell line) was performed by increasing the antibody titer. The expression of immune-related genes was evaluated by real-time PCR. The anti-LIF titer was significantly increased in the immunized group. The expression of genes related to the differentiation of T helper (Th)-1, Th-2, and Th-17 cells was significantly higher in the immunized group than in the control group. In addition, anti-LIF did not have a significant effect on the expression of genes related to the differentiation of regulatory T cells, and immune checkpoint-associated genes. Additionally, the test group had higher survival and lower tumor development rates. The results demonstrated that the anti-LIF antibody may potentially play a role in the differentiation of immune cells or immune responses. However, further studies utilizing advanced techniques are necessary to validate its function.

WNT1-inducible signaling pathway protein 1 activation through C-X-C motif chemokine ligand 5/C-X-C chemokine receptor type 2/leukemia inhibitory factor/leukemia inhibitory factor receptor signaling promotes immunosuppression and neuroendocrine differentiation in prostate cancer

The interaction between prostate cancer (PCa) cells and prostate stromal cells fosters an immunosuppressive tumor microenvironment (TME) that promotes tumor growth and immune evasion. However, the specific signaling pathways involved remain unclear. We identified a key mechanism involving the CXCL5/CXCR2 and LIF/LIFR pathways, which create a feedforward loop that enhances neuroendocrine differentiation (NED) in PCa cells and upregulates WNT1-inducible signaling pathway protein 1 (WISP1) in both cell types. WISP1 upregulation is essential for inducing immune checkpoints and immunosuppressive cytokines via LIF/LIFR signaling and STAT3 phosphorylation. This process leads to increased neuroendocrine markers, immune checkpoints, cell proliferation, and migration. Notably, WISP1 levels in patient sera correlate with PCa progression, suggesting its potential as a biomarker. Our findings elucidate the mechanisms by which reciprocal communication between PCa cells and stromal cells contributes to the formation of an immunosuppressive TME, driving the malignant progression of PCa and highlighting potential targets for therapeutic intervention.

The prognostic effect of tumor-associated macrophages in stage I-III colorectal cancer depends on T cell infiltration

BACKGROUND

Tumor-associated macrophages (TAMs) are associated with unfavorable patient prognosis in many cancer types. However, TAMs are a heterogeneous cell population and subsets have been shown to activate tumor-infiltrating T cells and confer a good patient prognosis. Data on the prognostic value of TAMs in colorectal cancer are conflicting. We investigated the prognostic effect of TAMs in relation to tumor-infiltrating T cells in colorectal cancers.

METHODS

The TAM markers CD68 and CD163 were analyzed by multiplex fluorescence immunohistochemistry and digital image analysis on tissue microarrays of 1720 primary colorectal cancers. TAM density in the tumor stroma was scored in relation to T cell density (stromal CD3+ and epithelial CD8+ cells) and analyzed in Cox proportional hazards models of 5-year relapse-free survival. Multivariable survival models included clinicopathological factors, MSI status and BRAFV600E mutation status.

RESULTS

High TAM density was associated with a favorable 5-year relapse-free survival in a multivariable model of patients with stage I-III tumors (p = 0.004, hazard ratio 0.94, 95% confidence interval 0.90-0.98). However, the prognostic effect was dependent on tumoral T-cell density. High TAM density was associated with a good prognosis in patients who also had high T-cell levels in their tumors, while high TAM density was associated with poorer prognosis in patients with low T-cell levels (pinteraction = 0.0006). This prognostic heterogeneity was found for microsatellite stable tumors separately.

CONCLUSIONS

This study supported a phenotypic heterogeneity of TAMs in colorectal cancer, and showed that combined tumor immunophenotyping of multiple immune cell types improved the prediction of patient prognosis.

Adeno-associated virus delivered CXCL9 sensitizes glioblastoma to anti-PD-1 immune checkpoint blockade

There are numerous mechanisms by which glioblastoma cells evade immunological detection, underscoring the need for strategic combinatorial treatments to achieve appreciable therapeutic effects. However, developing combination therapies is difficult due to dose-limiting toxicities, blood-brain-barrier, and suppressive tumor microenvironment. Glioblastoma is notoriously devoid of lymphocytes driven in part by a paucity of lymphocyte trafficking factors necessary to prompt their recruitment and activation. Herein, we develop a recombinant adeno-associated virus (AAV) gene therapy that enables focal and stable reconstitution of the tumor microenvironment with C-X-C motif ligand 9 (CXCL9), a powerful call-and-receive chemokine for lymphocytes. By manipulating local chemokine directional guidance, AAV-CXCL9 increases tumor infiltration by cytotoxic lymphocytes, sensitizing glioblastoma to anti-PD-1 immune checkpoint blockade in female preclinical tumor models. These effects are accompanied by immunologic signatures evocative of an inflamed tumor microenvironment. These findings support AAV gene therapy as an adjuvant for reconditioning glioblastoma immunogenicity given its safety profile, tropism, modularity, and off-the-shelf capability.

Early symptom-associated inflammatory responses shift to type 2 responses in controlled human schistosome infection

Schistosomiasis is an infection caused by contact with Schistosoma-contaminated water and affects more than 230 million people worldwide with varying morbidity. The roles of T helper 2 (TH2) cells and regulatory immune responses in chronic infection are well documented, but less is known about human immune responses during acute infection. Here, we comprehensively map immune responses during controlled human Schistosoma mansoni infection using male or female cercariae. Immune responses to male or female parasite single-sex infection were comparable. An early TH1-biased inflammatory response was observed at week 4 after infection, which was particularly apparent in individuals experiencing symptoms of acute schistosomiasis. By week 8 after infection, inflammatory responses were followed by an expansion of TH2 and regulatory cell subsets. This study demonstrates the shift from TH1 to both TH2 and regulatory responses, typical of chronic schistosomiasis, in the absence of egg production and provides immunological insight into the clinical manifestations of acute schistosomiasis.

Immunology of bile acids regulated receptors

Bile acids are steroids formed at the interface of host metabolism and intestinal microbiota. While primary bile acids are generated in the liver from cholesterol metabolism, secondary bile acids represent the products of microbial enzymes. Close to 100 different enzymatic modifications of bile acids structures occur in the human intestine and clinically guided metagenomic and metabolomic analyses have led to the identification of an extraordinary number of novel metabolites. These chemical mediators make an essential contribution to the composition and function of the postbiota, participating to the bidirectional communications of the intestinal microbiota with the host and contributing to the architecture of intestinal-liver and -brain and -endocrine axes. Bile acids exert their function by binding to a group of cell membrane and nuclear receptors collectively known as bile acid-regulated receptors (BARRs), expressed in monocytes, tissue-resident macrophages, CD4+ T effector cells, including Th17, T regulatory cells, dendritic cells and type 3 of intestinal lymphoid cells and NKT cells, highlighting their role in immune regulation. In this review we report on how bile acids and their metabolitesmodulate the immune system in inflammations and cancers and could be exploiting for developing novel therapeutic approaches in these disorders.

Chemokine ligand 14 correlates with immune cell infiltration in the gastric cancer microenvironment in predicting unfavorable prognosis

OBJECTIVE

Gastric cancer (GC) is the world's third-leading cause of cancer-related mortality; the prognosis for GC patients remains poor in terms of a lack of reliable biomarkers for early diagnosis and immune therapy response prediction. Here, we aim to discover the connection between chemokine ligand 14 (CCL14) expression in the gastric tumor microenvironment (TME) and its clinical significance and investigate its correlation with immune cell infiltration.

METHODS

We assessed CCL14 mRNA expression and its interrelation with tumor-infiltrating immune cells (TILs) using bioinformatics analysis in gastric cancer. CCL14 protein expression, TILs, and immune checkpoints were detected by multiple immunohistochemistry analyses in gastric cancer tissue microarrays. Then, we conducted statistics analysis to determine the association between CCL14-related patient survival and immune cell infiltration (p < 0.05).

RESULTS

We found that the CCL14 protein was separately expressed in the carcinoma cells and TILs in stomach cancer tissues. The CCL14 protein was related to tumor differentiation and tumor depth and positively correlated with the presentation of LAG3 and PD-L1 in gastric cancer cells. In addition, the CCL14 protein in the TILs of gastric cancer tissues was related to Lauren's type cells, T cells (CD4+ and CD8+), and CD68+ macrophages in the TME. Kaplan-Meier survival and multivariate analyses showed that the CCL14 expression in gastric cancer cells was an independent prognostic factor.

CONCLUSION

Our study illustrated that CCL14 is a poor prognosis biomarker in gastric cancer, which may be associated with the potential for immunotherapy.

Pharmacological inhibition of the LIF/LIFR autocrine loop reveals vulnerability of ovarian cancer cells to ferroptosis

Of all gynecologic cancers, epithelial-ovarian cancer (OCa) stands out with the highest mortality rates. Despite all efforts, 90% of individuals who receive standard surgical and cytotoxic therapy experience disease recurrence. The precise mechanism by which leukemia inhibitory factor (LIF) and its receptor (LIFR) contribute to the progression of OCa remains unknown. Analysis of cancer databases revealed that elevated expression of LIF or LIFR was associated with poor progression-free survival of OCa patients and a predictor of poor response to chemotherapy. Using multiple primary and established OCa cell lines or tissues that represent five subtypes of epithelial-OCa, we demonstrated that LIF/LIFR autocrine signaling is active in OCa. Moreover, treatment with LIFR inhibitor, EC359 significantly reduced OCa cell viability and cell survival with an IC50 ranging from 5-50 nM. Furthermore, EC359 diminished the stemness of OCa cells. Mechanistic studies using RNA-seq and rescue experiments unveiled that EC359 primarily induced ferroptosis by suppressing the glutathione antioxidant defense system. Using multiple in vitro, ex vivo and in vivo models including cell-based xenografts, patient-derived explants, organoids, and xenograft tumors, we demonstrated that EC359 dramatically reduced the growth and progression of OCa. Additionally, EC359 therapy considerably improved tumor immunogenicity by robust CD45+ leukocyte tumor infiltration and polarizing tumor-associated macrophages (TAMs) toward M1 phenotype while showing no impact on normal T-, B-, and other immune cells. Collectively, our findings indicate that the LIF/LIFR autocrine loop plays an essential role in OCa progression and that EC359 could be a promising therapeutic agent for OCa.

Antitumor Effects of an Anthocyanin-Rich Grain Diet in a Mouse Model of Lewis Lung Carcinoma

Functional foods enriched with plant polyphenol anthocyanins attract particular attention due to their health-promoting properties, including antitumor activity. We evaluated the effects of a grain diet rich in anthocyanins in a mouse model of Lewis lung carcinoma. Mice of the C57BL/6 strain were fed with wheat of near-isogenic lines differing in the anthocyanin content for four months prior to tumor transplantation. Although a significant decrease in the size of the tumor and the number of metastases in the lungs was revealed in the groups with both types of grain diet, the highest percentage of animals without metastases and with attenuated cell proliferation in the primary tumor were observed in the mice with the anthocyanin-rich diet. Both grain diets reduced the body weight gain and spleen weight index. The antitumor effects of the grain diets were associated with the activation of different mechanisms: immune response of the allergic type with augmented interleukin(IL)-9 and eotaxin serum levels in mice fed with control grain vs. inhibition of the IL-6/LIF system accompanied by a decrease in the tumor-associated M2 macrophage marker arginase 1 gene mRNA levels and enhanced autophagy in the tumor evaluated by the mRNA levels of Beclin 1 gene. Thus, anthocyanin-rich wheat is suggested as a promising source of functional nutrition with confirmed in vivo antitumor activity.

Bile acids serve as endogenous antagonists of the Leukemia inhibitory factor (LIF) receptor in oncogenesis

The leukemia inhibitory factor (LIF) is member of interleukin (IL)-6 family of cytokines involved immune regulation, morphogenesis and oncogenesis. In cancer tissues, LIF binds a heterodimeric receptor (LIFR), formed by a LIFRβ subunit and glycoprotein(gp)130, promoting epithelial mesenchymal transition and cell growth. Bile acids are cholesterol metabolites generated at the interface of host metabolism and the intestinal microbiota. Here we demonstrated that bile acids serve as endogenous antagonist to LIFR in oncogenesis. The tissue characterization of bile acids content in non-cancer and cancer biopsy pairs from gastric adenocarcinomas (GC) demonstrated that bile acids accumulate within cancer tissues, with glyco-deoxycholic acid (GDCA) functioning as negative regulator of LIFR expression. In patient-derived organoids (hPDOs) from GC patients, GDCA reverses LIF-induced stemness and proliferation. In summary, we have identified the secondary bile acids as the first endogenous antagonist to LIFR supporting a development of bile acid-based therapies in LIF-mediated oncogenesis.

Development and evaluation of a human CD47/HER2 bispecific antibody for Trastuzumab-resistant breast cancer immunotherapy

The treatment for trastuzumab-resistant breast cancer (BC) remains a challenge in clinical settings. It was known that CD47 is preferentially upregulated in HER2+ BC cells, which is correlated with drug resistance to trastuzumab. Here, we developed a novel anti-CD47/HER2 bispecific antibody (BsAb) against trastuzumab-resistant BC, named IMM2902. IMM2902 demonstrated high binding affinity, blocking activity, antibody-dependent cellular cytotoxicity (ADCC), antibody-dependent cellular phagocytosis (ADCP), and internalization degradation effects against both trastuzumab-sensitive and trastuzumab-resistant BC cells in vitro. The in vivo experimental data indicated that IMM2902 was more effective than their respective controls in inhibiting tumor growth in a trastuzumab-sensitive BT474 mouse model, a trastuzumab-resistant HCC1954 mouse model, two trastuzumab-resistant patient-derived xenograft (PDX) mouse models and a cord blood (CB)-humanized HCC1954 mouse model. Through spatial transcriptome assays, multiplex immunofluorescence (mIFC) and in vitro assays, our findings provided evidence that IMM2902 effectively stimulates macrophages to generate C-X-C motif chemokine ligand (CXCL) 9 and CXCL10, thereby facilitating the recruitment of T cells and NK cells to the tumor site. Moreover, IMM2902 demonstrated a high safety profile regarding anemia and non-specific cytokines release. Collectively, our results highlighted a novel therapeutic approach for the treatment of HER2+ BCs and this approach exhibits significant anti-tumor efficacy without causing off-target toxicity in trastuzumab-resistant BC cells.

CXCL9/10-engineered dendritic cells promote T cell activation and enhance immune checkpoint blockade for lung cancer

Immune checkpoint blockade (ICB) with PD-1/PD-L1 inhibition has revolutionized the treatment of non-small cell lung cancer (NSCLC). Durable responses, however, are observed only in a subpopulation of patients. Defective antigen presentation and an immunosuppressive tumor microenvironment (TME) can lead to deficient T cell recruitment and ICB resistance. We evaluate intratumoral (IT) vaccination with CXCL9- and CXCL10-engineered dendritic cells (CXCL9/10-DC) as a strategy to overcome resistance. IT CXCL9/10-DC leads to enhanced T cell infiltration and activation in the TME and tumor inhibition in murine NSCLC models. The antitumor efficacy of IT CXCL9/10-DC is dependent on CD4+ and CD8+ T cells, as well as CXCR3-dependent T cell trafficking from the lymph node. IT CXCL9/10-DC, in combination with ICB, overcomes resistance and establishes systemic tumor-specific immunity in murine models. These studies provide a mechanistic understanding of CXCL9/10-DC-mediated host immune activation and support clinical translation of IT CXCL9/10-DC to augment ICB efficacy in NSCLC.

Pharmacological Polarization of Tumor-Associated Macrophages Toward a CXCL9 Antitumor Phenotype

Tumor-associated macrophages (TAM) are a diverse population of myeloid cells that are often abundant and immunosuppressive in human cancers. CXCL9Hi TAM has recently been described to have an antitumor phenotype and is linked to immune checkpoint response. Despite the emerging understanding of the unique antitumor TAM phenotype, there is a lack of TAM-specific therapeutics to exploit this new biological understanding. Here, the discovery and characterization of multiple small-molecule enhancers of chemokine ligand 9 (CXCL9) and their targeted delivery in a TAM-avid systemic nanoformulation is reported. With this strategy, it is efficient encapsulation and release of multiple drug loads that can efficiently induce CXCL9 expression in macrophages, both in vitro and in vivo in a mouse tumor model. These observations provide a window into the molecular features that define TAM-specific states, an insight a novel therapeutic anticancer approach is used to discover.

Single cell and bulk RNA sequencing identifies tumor microenvironment subtypes and chemoresistance-related IGF1+ cancer-associated fibroblast in gastric cancer

BACKGROUND

The tumor microenvironment (TME) significantly influences prognosis and drug resistance in various tumors, yet its heterogeneity and the mechanisms affecting therapeutic response remain unclear in gastric cancer (GC).

METHODS

The heterogenous TME were explored with single-cell RNA-sequencing (scRNA-seq) data of 50 primary GC samples. We then identified four GC TME subtypes with nonnegative matrix factorization (NMF) and constructed a pearson nearest-centroid classifier based on subtype-specific upregulated genes. Genomic features and clinical significance of four subtypes were comprehensively evaluated. We reclustered fibroblasts to identify cancer-associated fibroblast (CAF) subtype associated with poor clinical outcomes. RT-qPCR and double immunofluorescence staining were applied to validate the findings. Cellchat analysis elucidated potential molecular mechanisms of the CAF subtype in GC disease progression and chemotherapy resistance.

FINDINGS

The GC TME exhibited high heterogeneity, influencing chemo-sensitivity. Four TME-based subtypes predicting response to immunotherapy and chemotherapy were identified and validated in 1406 GC patients. Among which, ISG1 subtype displayed higher fibroblasts infiltration and heightened oncogenic pathways, and inferior response to chemotherapy with unfavorable prognosis. Microsatellite instability-high (MSI-H) GCs within four TME subtypes showed immunological heterogeneity. We then reported an IGF1-overexpressing CAF was associated with chemo-resistance and GC recurrence. Cell communication analysis revealed IGF1+ CAF may induce drug-resistant phenotypes in tumor cells through IGF1-α6β4 integrin ligand-receptor binding and activation of EMT biological process.

INTERPRETATION

We identified four TME-based subtypes with different clinical outcomes and IGF1+ CAFs contributing to poor clinical outcomes in GC, which might provide guidance for individualized treatment and facilitate the development of novel therapeutic targets.

The CLCF1-CNTFR axis drives an immunosuppressive tumor microenvironment and blockade enhances the effects of established cancer therapies

Tumors comprise a complex ecosystem consisting of many cell types that communicate through secreted factors. Targeting these intercellular signaling networks remains an important challenge in cancer research. Cardiotrophin-like cytokine factor 1 (CLCF1) is an interleukin-6 (IL-6) family member secreted by cancer-associated fibroblasts (CAFs) that binds to ciliary neurotrophic factor receptor (CNTFR), promoting tumor growth in lung and liver cancer1,2. A high-affinity soluble receptor (eCNTFR-Fc) that sequesters CLCF1 has anti-oncogenic effects3. However, the role of CLCF1 in mediating cell-cell interactions in cancer has remained unclear. We demonstrate that eCNTFR-Fc has widespread effects on both tumor cells and the tumor microenvironment and can sensitize cancer cells to KRAS inhibitors or immune checkpoint blockade. After three weeks of treatment with eCNTFR-Fc, there is a shift from an immunosuppressive to an immunostimulatory macrophage phenotype as well as an increase in activated T, NKT, and NK cells. Combination of eCNTFR-Fc and αPD1 was significantly more effective than single-agent therapy in a syngeneic allograft model, and eCNTFR-Fc sensitizes tumor cells to αPD1 in a non-responsive GEM model of lung adenocarcinoma. These data suggest that combining eCNTFR-Fc with KRAS inhibition or with αPD1 is a novel therapeutic strategy for lung cancer and potentially other cancers in which these therapies have been used but to date with only modest effect. Overall, we demonstrate the potential of cancer therapies that target cytokines to alter the immune microenvironment.

Immune cell networking in solid tumors: focus on macrophages and neutrophils

The tumor microenvironment is composed of tumor cells, stromal cells and leukocytes, including innate and adaptive immune cells, and represents an ecological niche that regulates tumor development and progression. In general, inflammatory cells are considered to contribute to tumor progression through various mechanisms, including the formation of an immunosuppressive microenvironment. Macrophages and neutrophils are important components of the tumor microenvironment and can act as a double-edged sword, promoting or inhibiting the development of the tumor. Targeting of the immune system is emerging as an important therapeutic strategy for cancer patients. However, the efficacy of the various immunotherapies available is still limited. Given the crucial importance of the crosstalk between macrophages and neutrophils and other immune cells in the formation of the anti-tumor immune response, targeting these interactions may represent a promising therapeutic approach against cancer. Here we will review the current knowledge of the role played by macrophages and neutrophils in cancer, focusing on their interaction with other immune cells.

Chemoimmunotherapeutic Nanogel for Pre- and Postsurgical Treatment of Malignant Melanoma by Reprogramming Tumor-Associated Macrophages

Surgery is the primary method to treat malignant melanoma; however, the residual microtumors that cannot be resected completely often trigger tumor recurrence, causing tumor-related mortality following melanoma resection. Herein, we developed a feasible strategy based on the combinational chemoimmunotherapy by cross-linking carboxymethyl chitosan (CMCS)-originated polymetformin (PolyMetCMCS) with cystamine to prepare stimuli-responsive nanogel (PMNG) owing to the disulfide bond in cystamine that can be cleaved by the massive glutathione (GSH) in tumor sites. Then, chemotherapeutic agent doxorubicin (DOX) was loaded in PMNG, which was followed by a hyaluronic acid coating to improve the overall biocompatibility and targeting ability of the prepared nanogel (D@HPMNG). Notably, PMNG effectively reshaped the tumor immune microenvironment by reprogramming tumor-associated macrophage phenotypes and recruiting intratumoral CD8+ T cells owing to the inherited immunomodulatory capability of metformin. Consequently, D@HPMNG treatment remarkably suppressed melanoma growth and inhibited its recurrence after surgical resection, proposing a promising solution for overcoming lethal melanoma recurrence.

Blockade of C5a receptor unleashes tumor-associated macrophage antitumor response and enhances CXCL9-dependent CD8+ T cell activity

Macrophages play a crucial role in shaping the immune state within the tumor microenvironment (TME) and are often influenced by tumors to hinder antitumor immunity. However, the underlying mechanisms are still elusive. Here, we observed abnormal expression of complement 5a receptor (C5aR) in human ovarian cancer (OC), and identified high levels of C5aR expression on tumor-associated macrophages (TAMs), which led to the polarization of TAMs toward an immunosuppressive phenotype. C5aR knockout or inhibitor treatment restored TAM antitumor response and attenuated tumor progression. Mechanistically, C5aR deficiency reprogrammed macrophages from a protumor state to an antitumor state, associating with the upregulation of immune response and stimulation pathways, which in turn resulted in the enhanced antitumor response of cytotoxic T cells in a manner dependent on chemokine (C-X-C motif) ligand 9 (CXCL9). The pharmacological inhibition of C5aR also improved the efficacy of immune checkpoint blockade therapy. In patients, C5aR expression associated with CXCL9 production and infiltration of CD8+ T cells, and a high C5aR level predicted poor clinical outcomes and worse benefits from anti-PD-1 therapy. Thus, our study sheds light on the mechanisms underlying the modulation of TAM antitumor immune response by the C5a-C5aR axis and highlights the potential of targeting C5aR for clinical applications.

Cell-cell communication network-based interpretable machine learning predicts cancer patient response to immune checkpoint inhibitors

Immune checkpoint inhibitors (ICIs) have revolutionized cancer treatment. However, only some patients respond to ICIs, and current biomarkers for ICI efficacy have limited performance. Here, we devised an interpretable machine learning (ML) model trained using patient-specific cell-cell communication networks (CCNs) decoded from the patient's bulk tumor transcriptome. The model could (i) predict ICI efficacy for patients across four cancer types (median AUROC: 0.79) and (ii) identify key communication pathways with crucial players responsible for patient response or resistance to ICIs by analyzing more than 700 ICI-treated patient samples from 11 cohorts. The model prioritized chemotaxis communication of immune-related cells and growth factor communication of structural cells as the key biological processes underlying response and resistance to ICIs, respectively. We confirmed the key communication pathways and players at the single-cell level in patients with melanoma. Our network-based ML approach can be used to expand ICIs' clinical benefits in cancer patients.

NK cell-triggered CCL5/IFNγ-CXCL9/10 axis underlies the clinical efficacy of neoadjuvant anti-HER2 antibodies in breast cancer

BACKGROUND

The variability in responses to neoadjuvant treatment with anti-HER2 antibodies prompts to personalized clinical management and the development of innovative treatment strategies. Tumor-infiltrating Natural Killer (TI-NK) cells can predict the efficacy of HER2-targeted antibodies independently from clinicopathological factors in primary HER2-positive breast cancer patients. Understanding the mechanism/s underlying this association would contribute to optimizing patient stratification and provide the rationale for combinatorial approaches with immunotherapy.

METHODS

We sought to uncover processes enriched in NK cell-infiltrated tumors as compared to NK cell-desert tumors by microarray analysis. Findings were validated in clinical trial-derived transcriptomic data. In vitro and in vivo preclinical models were used for mechanistic studies. Findings were analysed in clinical samples (tumor and serum) from breast cancer patients.

RESULTS

NK cell-infiltrated tumors were enriched in CCL5/IFNG-CXCL9/10 transcripts. In multivariate logistic regression analysis, IFNG levels underlie the association between TI-NK cells and pathological complete response to neoadjuvant treatment with trastuzumab. Mechanistically, the production of IFN-ɣ by CD16+ NK cells triggered the secretion of CXCL9/10 from cancer cells. This effect was associated to tumor growth control and the conversion of CD16 into CD16-CD103+ NK cells in humanized in vivo models. In human breast tumors, the CD16 and CD103 markers identified lineage-related NK cell subpopulations capable of producing CCL5 and IFN-ɣ, which correlated with tissue-resident CD8+ T cells. Finally, an early increase in serum CCL5/CXCL9 levels identified patients with NK cell-rich tumors showing good responses to anti-HER2 antibody-based neoadjuvant treatment.

CONCLUSIONS

This study identifies specialized NK cell subsets as the source of IFN-ɣ influencing the clinical efficacy of anti-HER2 antibodies. It also reveals the potential of serum CCL5/CXCL9 as biomarkers for identifying patients with NK cell-rich tumors and favorable responses to anti-HER2 antibody-based neoadjuvant treatment.

Emerging role of cancer-associated fibroblasts in esophageal squamous cell carcinoma

Esophageal carcinoma is the sixth leading cause of cancer death globally and the majority of global cases are esophageal squamous cell carcinoma (ESCC). Difficulty in diagnosis exists as more than 70% of ESCC patients are diagnosed at the intermediate or advanced stage. Cancer-associated fibroblasts (CAFs) have been considered one of the crucial components in the process of tumor growth, promoting communications between cancer cells and the tumor microenvironment (TME). CAFs grow alongside malignancies dynamically and interact with ESCC cells to promote their progression, proliferation, invasion, tumor escape, chemo- and radio-resistance, etc. It is believed that CAFs qualify as a promising direction for treatment. Analyzing CAFs' subtypes and functions will elucidate the involvement of CAFs in ESCC and aid in therapeutics. This review summarizes current information on CAFs in ESCC and focuses on the latest interaction between CAFs and ESCC cancer cell discoveries. The origin of CAFs and their communication with ESCC cells and TME are also demonstrated. On the foundation of a thorough analysis, we highlight the clinical prospects and CAFs-related therapies in ESCC in the future.

Lactate-Induced CCL8 in Tumor-Associated Macrophages Accelerates the Progression of Colorectal Cancer through the CCL8/CCR5/mTORC1 Axis

Tumor-associated macrophages (TAMs) play a pivotal role in shaping the tumor microenvironment. Lactic acid (LA) has been identified as an influential factor in promoting immune escape and tumor progression. However, the mechanisms through which LA modulates TAMs in colorectal cancer (CRC) remain poorly understood. We used qRT-PCR to quantify the expression of LA-related genes (LDHA and LAMP2) in CRC tumor tissues and adjacent nontumor tissues (n = 64). The biological effects and mechanisms of LA on macrophages and tumors were evaluated via qRT-PCR, Western blot, RNA-seq, wound healing assay, colony formation assay in vitro, and allograft mouse tumor models in vivo. We found the expression of LDHA and LAMP2 was highly elevated in the tumor regions and positively associated with a poor clinical stage of CRC. A high concentration of LA was generated under hypoxia; it could promote tumor progression and metastasis with the involvement of macrophages. The inhibition of LA release impaired this protumor phenomenon. Mechanically, LA induced M2 macrophages through the AKT/ERK signaling pathway; subsequently, M2 macrophages secreted CCL8 and facilitated the proliferation and metastasis of CRC cells by activating the CCL8/CCR5/mTORC1 axis. This effect was inhibited by the antagonist or knockdown of CCR5. In conclusion, lactate-induced CCL8 in TAMs accelerated CRC proliferation and metastasis through the CCL8/CCR5/mTORC1 axis.

Nanoparticles (NPs)-mediated Siglec15 silencing and macrophage repolarization for enhanced cancer immunotherapy

T cell infiltration and proliferation in tumor tissues are the main factors that significantly affect the therapeutic outcomes of cancer immunotherapy. Emerging evidence has shown that interferon-gamma (IFNγ) could enhance CXCL9 secretion from macrophages to recruit T cells, but Siglec15 expressed on TAMs can attenuate T cell proliferation. Therefore, targeted regulation of macrophage function could be a promising strategy to enhance cancer immunotherapy via concurrently promoting the infiltration and proliferation of T cells in tumor tissues. We herein developed reduction-responsive nanoparticles (NPs) made with poly (disulfide amide) (PDSA) and lipid-poly (ethylene glycol) (lipid-PEG) for systemic delivery of Siglec15 siRNA (siSiglec15) and IFNγ for enhanced cancer immunotherapy. After intravenous administration, these cargo-loaded could highly accumulate in the tumor tissues and be efficiently internalized by tumor-associated macrophages (TAMs). With the highly concentrated glutathione (GSH) in the cytoplasm to destroy the nanostructure, the loaded IFNγ and siSiglec15 could be rapidly released, which could respectively repolarize macrophage phenotype to enhance CXCL9 secretion for T cell infiltration and silence Siglec15 expression to promote T cell proliferation, leading to significant inhibition of hepatocellular carcinoma (HCC) growth when combining with the immune checkpoint inhibitor. The strategy developed herein could be used as an effective tool to enhance cancer immunotherapy.

Enhancement of Microglia Functions by Developed Nano-Immuno-Synergist to Ameliorate Immunodeficiency for Malignant Glioma Treatment

Resident microglia are key factors in mediating immunity against brain tumors, but the microglia in malignant glioma are functionally impaired. Little immunotherapy is explored to restore microglial function against glioma. Herein, oleanolic acid (OA) (microglia "restorer") and D PPA-1 peptide (immune checkpoint blockade) are integrated on a nano-immuno-synergist (D PAM@OA) to work coordinately. The self-assembled OA core is coated with macrophage membrane for efficient blood-brain barrier penetration and microglia targeting, on which D PPA-1 peptide is attached via acid-sensitive bonds for specific release in tumor microenvironment. With the enhanced accumulation of the dual drugs in their respective action sites, D PAM@OA effectively promotes the recruitment and activation of effector T cells by inhibiting aberrant activation of Signal transducer and activator of transcription (STAT-3) pathway in microglia, and assists activated effector T cells in killing tumor cells by blocking elevated immune checkpoint proteins in malignant glioma. Eventually, as adjuvant therapy, the rationally designed nano-immuno-synergist hinders malignant glioma progression and recurrence with or without temozolomide. The work demonstrates the feasibility of a nano-formulation for microglia-based immunotherapy, which may provide a new direction for the treatment of brain tumors.

Facts and Hopes on Neutralization of Protumor Inflammatory Mediators in Cancer Immunotherapy

In cancer pathogenesis, soluble mediators are responsible for a type of inflammation that favors the progression of tumors. The mechanisms chiefly involve changes in the cellular composition of the tumor tissue stroma and in the functional modulation of myeloid and lymphoid leukocytes. Active immunosuppression, proangiogenesis, changes in leukocyte traffic, extracellular matrix remodeling, and alterations in tumor-antigen presentation are the main mechanisms linked to the inflammation that fosters tumor growth and metastasis. Soluble inflammatory mediators and their receptors are amenable to various types of inhibitors that can be combined with other immunotherapy approaches. The main proinflammatory targets which can be interfered with at present and which are under preclinical and clinical development are IL1β, IL6, the CXCR1/2 chemokine axis, TNFα, VEGF, leukemia inhibitory factor, CCL2, IL35, and prostaglandins. In many instances, the corresponding neutralizing agents are already clinically available and can be repurposed as a result of their use in other areas of medicine such as autoimmune diseases and chronic inflammatory conditions.

Enhanced infection efficiency and cytotoxicity mediated by vpx-containing lentivirus in chimeric antigen receptor macrophage (CAR-M)

Genetically modified macrophage infusion has been proven to be a novel treatment for cancer. One of the most important processes in macrophage-based therapy is the efficient transfer of genes. HIV-1-derived lentiviruses were widely used as delivery vectors in chimeric antigen receptor T and NK cell construction. While macrophages are relatively refractory to this lentiviral vector transduction as a result of the myeloid-specific restriction factor SAMHD1, which inhibited the virion cycle through exhausting the dNTPs pool and degradating RNAs. An efficient macrophage transduction strategy has been developed via packaging the HIV-2 accessory protein Vpx into the virion. Vpx counteracts SAMHD1 through CRL4 (DCAF1) E3 ubiquitin ligase mediated SAMHD1 degradation, yet the influence by the introduction of Vpx on macrophage has not been fully evaluated. Here, we constructed the chimeric lentiviral vector HIV-1-Vpx and systematically analyzed the infection efficiency of this vector in time-dependent manner. Our results showed that the simplified chimeric virus exhibited dramatically enhanced infection in human macrophages compared to normal lentivirus. Moreover, transcriptome sequencing was performed to evaluate the cellular status after chimeric virus infection. The sequencing results indicated that Vpx introduction promoted macrophage remodeling towards a proinflammatory phenotype, without affecting classic M1/M2 cell surface markers. Our results suggest that the Vpx-containing lentivirus could be used as an ideal tool for the generation of genetically engineered macrophages with high gene transfer efficiency and poised proinflammatory gene sets, especially for solid tumor treatment.

Epigenome-Driven Strategies for Personalized Cancer Immunotherapy

Fighting cancer remains one of the greatest challenges for science in the 21st century. Advances in immunotherapy against different types of cancer have greatly contributed to the treatment, remission, and cure of patients. In this context, knowledge of epigenetic phenomena, their relationship with tumor cells and how the immune system can be epigenetically modulated represent some of the greatest advances in the development of anticancer therapies. Epigenetics is a rapidly growing field that studies how environmental factors can affect gene expression without altering DNA sequence. Epigenomic changes include DNA methylation, histone modifications, and non-coding RNA regulation, which impact cellular function. Epigenetics has shown promise in developing cancer therapies, such as immunotherapy, which aims to stimulate the immune system to attack cancer cells. For example, PD-1 and PD-L1 are biomarkers that regulate the immune response to cancer cells and recent studies have shown that epigenetic modifications can affect their expression, potentially influencing the efficacy of immunotherapy. New therapies targeting epigenetic modifications, such as histone deacetylases and DNA methyltransferases, are being developed for cancer treatment, and some have shown promise in preclinical studies and clinical trials. With growing understanding of epigenetic regulation, we can expect more personalized and effective cancer immunotherapies in the future. This review highlights key advances in the use of epigenetic and epigenomic tools and modern immuno-oncology strategies to treat several types of tumors.

IκB kinase-α coordinates BRD4 and JAK/STAT signaling to subvert DNA damage-based anticancer therapy

Activation of the IκB kinase (IKK) complex has recurrently been linked to colorectal cancer (CRC) initiation and progression. However, identification of downstream effectors other than NF-κB has remained elusive. Here, analysis of IKK-dependent substrates in CRC cells after UV treatment revealed that phosphorylation of BRD4 by IKK-α is required for its chromatin-binding at target genes upon DNA damage. Moreover, IKK-α induces the NF-κB-dependent transcription of the cytokine LIF, leading to STAT3 activation, association with BRD4 and recruitment to specific target genes. IKK-α abrogation results in defective BRD4 and STAT3 functions and consequently irreparable DNA damage and apoptotic cell death upon different stimuli. Simultaneous inhibition of BRAF-dependent IKK-α activity, BRD4, and the JAK/STAT pathway enhanced the therapeutic potential of 5-fluorouracil combined with irinotecan in CRC cells and is curative in a chemotherapy-resistant xenograft model. Finally, coordinated expression of LIF and IKK-α is a poor prognosis marker for CRC patients. Our data uncover a functional link between IKK-α, BRD4, and JAK/STAT signaling with clinical relevance.

New perspectives in cancer immunotherapy: targeting IL-6 cytokine family

Chronic inflammation has been recognized as a canonical cancer hallmark. It is orchestrated by cytokines, which are master regulators of the tumor microenvironment (TME) as they represent the main communication bridge between cancer cells, the tumor stroma, and the immune system. Interleukin (IL)-6 represents a keystone cytokine in the link between inflammation and cancer. Many cytokines from the IL-6 family, which includes IL-6, oncostatin M, leukemia inhibitory factor, IL-11, IL-27, IL-31, ciliary neurotrophic factor, cardiotrophin 1, and cardiotrophin-like cytokine factor 1, have been shown to elicit tumor-promoting roles by modulating the TME, making them attractive therapeutic targets for cancer treatment.The development of immune checkpoint blockade (ICB) immunotherapies has radically changed the outcome of some cancers including melanoma, lung, and renal, although not without hurdles. However, ICB shows limited efficacy in other solid tumors. Recent reports support that chronic inflammation and IL-6 cytokine signaling are involved in resistance to immunotherapy. This review summarizes the available preclinical and clinical data regarding the implication of IL-6-related cytokines in regulating the immune TME and the response to ICB. Moreover, the potential clinical benefit of combining ICB with therapies targeting IL-6 cytokine members for cancer treatment is discussed.

Upregulation of exosome secretion from tumor-associated macrophages plays a key role in the suppression of anti-tumor immunity

Macrophages play a pivotal role in tumor immunity. We report that reprogramming of macrophages to tumor-associated macrophages (TAMs) promotes the secretion of exosomes. Mechanistically, increased exosome secretion is driven by MADD, which is phosphorylated by Akt upon TAM induction and activates Rab27a. TAM exosomes carry high levels of programmed death-ligand 1 (PD-L1) and potently suppress the proliferation and function of CD8+ T cells. Analysis of patient melanoma tissues indicates that TAM exosomes contribute significantly to CD8+ T cell suppression. Single-cell RNA sequencing analysis showed that exosome-related genes are highly expressed in macrophages in melanoma; TAM-specific RAB27A expression inversely correlates with CD8+ T cell infiltration. In a murine melanoma model, lipid nanoparticle delivery of small interfering RNAs (siRNAs) targeting macrophage RAB27A led to better T cell activation and sensitized tumors to anti-programmed cell death protein 1 (PD-1) treatment. Our study demonstrates tumors use TAM exosomes to combat CD8 T cells and suggests targeting TAM exosomes as a potential strategy to improve immunotherapies.