Interleukin 32 Promotes Foxp3+ Treg Cell Development and CD8+ T Cell Function in Human Esophageal Squamous Cell Carcinoma Microenvironment

Dual MAPK Inhibition Triggers Pro-inflammatory Signals and Sensitizes BRAF V600E Glioma to T Cell-Mediated Checkpoint Therapy

BRAF V600E pediatric low-grade gliomas frequently transform into high-grade gliomas (HGG) and poorly respond to chemotherapy, resulting in high mortality. Although combined BRAF and MEK inhibition (BRAFi+MEKi) outperforms chemotherapy, ∼70% of BRAF V600E HGG patients are therapy resistant and undergo unbridled tumor progression. BRAF V600E glioma have an immune-rich microenvironment suggesting that they could be responsive to immunotherapy but effects of BRAFi+MEKi on anti-tumor immunity are unclear. Using patient tumor tissue before and after BRAFi+MEKi, two novel syngeneic murine models of BRAF V600E HGG, and patient-derived cell lines, we examined the effects of clinically relevant BRAFi+MEKi with dabrafenib and trametinib on tumor growth, cell states, and tumor-infiltrating T cells. We find that BRAFi+MEKi treatment: i) upregulated programmed cell death protein-1 (PD-1) signaling genes and PD-1 ligand (PD-L1) protein expression in murine BRAF V600E HGG by stimulating IFNγ and IL-27, ii) attenuated T cell activity by IL-23, IL-27 and IL-32 production, which can promote the expansion of regulatory T cells, and iii) induced glial differentiation linked to a therapy-resistant PD-L1+ compartment through Galectin-3 secretion by tumor cells. Murine BRAF V600E HGG shrinkage by BRAFi+MEKi is associated with the upregulation of interferon-gamma response genes, MHC class I/II expression, and antigen presentation and processing programs, indicative of increased anti-tumor immunity. Combined BRAFi+MEKi with therapeutic antibodies inhibiting the PD-1 and cytotoxic T-lymphocyte associated protein 4 (CTLA-4) immune checkpoints re-activate T cells and provide a survival benefit over single therapy in a T cell-dependent manner. The quadruple treatment overcame BRAFi+MEKi resistance by invigorating T cell-mediated anti-tumor immunity in murine BRAF V600E HGG. PD-L1 expression was elevated in human BRAF-mutant versus BRAF-wildtype glioblastoma clinical specimen, complementing experimental findings and suggesting translational relevance for patient care.

Single-cell Profiling of Intrahepatic Immune Cells Reveals an Expansion of Tissue-resident Cytotoxic CD4+ T Lymphocyte Subset Associated With Pathogenesis of Alcoholic-associated Liver Diseases

BACKGROUND & AIMS

The immunological mechanisms underpinning the pathogenesis of alcoholic-associated liver disease (ALD) remain incompletely elucidated. This study aims to explore the transcriptomic profiles of hepatic immune cells in ALD compared with healthy individuals and those with metabolic dysfunction-associated steatotic liver disease (MASLD).

METHODS

We utilized single-cell RNA sequencing to analyze liver samples from healthy subjects and patients with MASLD and ALD, focusing on the immune cell landscapes within the liver. Key alterations in immune cell subsets were further validated using liver biopsy samples from additional patient cohorts.

RESULTS

We observed a significant accumulation of CD4+ T cells in livers of patients with ALD, surpassing the prevalence of CD8+ T cells, in contrast to patients with MASLD and healthy counterparts, whereas natural killer (NK) cells and γδT cells exhibited reduced intrahepatic infiltration. In-depth transcriptional and developmental trajectory analyses unveiled that a distinct CD4+ subset characterized by granzyme K (GZMK) expression, displaying a tissue-resident signature and terminal effector state, prominently enriched among CD4+ T cells infiltrating the livers of patients with ALD. Subsequent examination of an independent ALD patient cohort corroborated the substantial enrichment of GZMK+CD4+ T lymphocytes, primarily within liver fibrotic zones, suggesting their potential involvement in disease progression. Additionally, we noted shifts in myeloid populations, with expanded APOE+ macrophage and FCGR3B+ monocyte subsets in ALD samples relative to MASLD and healthy tissues.

CONCLUSIONS

In summary, this study unravels the intricate cellular diversity within hepatic immune cell populations, highlighting the pivotal immune pathogenic role of the GZMK+CD4+ T lymphocyte subset in ALD pathogenesis.

Mechanisms of tumor immunosuppressive microenvironment formation in esophageal cancer

As a highly invasive malignancy, esophageal cancer (EC) is a global health issue, and was the eighth most prevalent cancer and the sixth leading cause of cancer-related death worldwide in 2020. Due to its highly immunogenic nature, emer-ging immunotherapy approaches, such as immune checkpoint blockade, have demonstrated promising efficacy in treating EC; however, certain limitations and challenges still exist. In addition, tumors may exhibit primary or acquired resistance to immunotherapy in the tumor immune microenvironment (TIME); thus, understanding the TIME is urgent and crucial, especially given the im-portance of an immunosuppressive microenvironment in tumor progression. The aim of this review was to better elucidate the mechanisms of the suppressive TIME, including cell infiltration, immune cell subsets, cytokines and signaling pathways in the tumor microenvironment of EC patients, as well as the downregulated expression of major histocompatibility complex molecules in tumor cells, to obtain a better understanding of the differences in EC patient responses to immunotherapeutic strategies and accurately predict the efficacy of immunotherapies. Therefore, personalized treatments could be developed to maximize the advantages of immunotherapy.

Self-supervised learning of T cell receptor sequences exposes core properties for T cell membership

The T cell receptor (TCR) repertoire is an extraordinarily diverse collection of TCRs essential for maintaining the body's homeostasis and response to threats. In this study, we compiled an extensive dataset of more than 4200 bulk TCR repertoire samples, encompassing 221,176,713 sequences, alongside 6,159,652 single-cell TCR sequences from over 400 samples. From this dataset, we then selected a representative subset of 5 million bulk sequences and 4.2 million single-cell sequences to train two specialized Transformer-based language models for bulk (CVC) and single-cell (scCVC) TCR repertoires, respectively. We show that these models successfully capture TCR core qualities, such as sharing, gene composition, and single-cell properties. These qualities are emergent in the encoded TCR latent space and enable classification into TCR-based qualities such as public sequences. These models demonstrate the potential of Transformer-based language models in TCR downstream applications.

Pan-cancer analysis reveals IL32 is a potential prognostic and immunotherapeutic biomarker in cancer

Interleukin 32 (IL32) is a pro-inflammatory cytokine that plays a key role in promoting sterile inflammation by modulating immune responses. However, the role of IL32 in various cancers remains unclear. This research aimed to investigate the correlation between IL32 expression and immunity and visualize its prognostic landscape in pan-cancer. We investigated gene expression, genomic alterations, and survival analysis of IL32 in pan-cancer in numerous databases including TCGA, GTEx, cBioPortal, and GDC databases. Tumor immune cell infiltration was assessed using the CIBERSORT computational method as well as the ESTIMATE method to analyze the correlation of IL32 expression with stromal and immune components. Protein-protein interaction analysis was performed in the STRING and GeneMANIA databases, and gene function enrichment was performed by GO set enrichment analysis. Tumor tissues had higher IL32 expression levels than normal tissues. Elevated IL32 expression was associated with poor OS and prognosis. In addition, tumor stemness, TMB, MSI, and immune checkpoint genes were also associated with IL32 expression. Correlations were observed between IL32 expression and B cell, CD4T cell, CD8T cell, neutrophil, macrophage, and DC infiltration in multiple cancers. GO enrichment analysis showed that IL32 expression was associated with cancer pathways, cytokine-receptor interactions, and NOD-like receptor signaling pathways. These findings suggest that IL32 may serve as a biomarker of cancer immune infiltration and poor prognosis, providing new therapeutic targets for cancer treatment.

The Role of Cytokines in Cutaneous T Cell Lymphoma: A Focus on the State of the Art and Possible Therapeutic Targets

Cutaneous T cell lymphomas (CTCLs), encompassing mycosis fungoides (MF) and Sézary syndrome (SS), present a complex landscape influenced by cytokines and cellular responses. In this work, the intricate relationship between these inflammatory proteins and disease pathogenesis is examined, focusing on what is known at the clinical and therapeutic levels regarding the most well-known inflammatory mediators. An in-depth look is given to their possible alterations caused by novel immunomodulatory drugs and how they may alter disease progression. From this narrative review of the actual scientific landscape, Interferon-gamma (IFN-γ) emerges as a central player, demonstrating a dual role in both promoting and inhibiting cancer immunity, but the work navigates through all the major interleukins known in inflammatory environments. Immunotherapeutic perspectives are elucidated, highlighting the crucial role of the cutaneous microenvironment in shaping dysfunctional cell trafficking, antitumor immunity, and angiogenesis in MF, showcasing advancements in understanding and targeting the immune phenotype in CTCL. In summary, this manuscript aims to comprehensively explore the multifaceted aspects of CTCL, from the immunopathogenesis and cytokine dynamics centred around TNF-α and IFN-γ to evolving therapeutic modalities. Including all the major known and studied cytokines in this analysis broadens our understanding of the intricate interplay influencing CTCL, paving the way for improved management of this complex lymphoma.

Data driven analysis reveals prognostic genes and immunological targets in human sepsis-associated acute kidney injury

BACKGROUND

The molecular mechanism of sepsis-associated acute kidney injury (SA-AKI) is unclear. We analyzed co-differentially expressed genes (co-DEGs) to elucidate the underlying mechanism and intervention targets of SA-AKI.

METHODS

The microarray datasets GSE65682, GSE30718, and GSE174220 were downloaded from the Gene Expression Omnibus (GEO) database. We identified the co-DEGs and constructed a gene co-expression network to screen the hub genes. We analyzed immune correlations and disease correlations and performed functional annotation of the hub genes. We also performed single-cell and microenvironment analyses and investigated the enrichment pathways and the main transcription factors. Finally, we conducted a correlation analysis to evaluate the role of the hub genes.

RESULTS

Interleukin 32 (IL32) was identified as the hub gene in SA-AKI, and the main enriched signaling pathways were associated with hemopoiesis, cellular response to cytokine stimulus, inflammatory response, and regulation of kidney development. Additionally, IL32 was significantly associated with mortality in SA-AKI patients. Monocytes, macrophages, T cells, and NK cells were closely related to IL32 and were involved in the immune microenvironment in SA-AKI patients. IL32 expression increased significantly in the kidney of septic mouse. Toll-like receptor 2 (TLR2) was significantly and negatively correlated with IL32.

CONCLUSION

IL32 is the key gene involved in SA-AKI and is significantly associated with prognosis. TLR2 and relevant immune cells are closely related to key genes.

Chronic HCV infection promotes cytotoxicity in antigen-specific CD8+ T cells regardless of virus specificity

Introduction

Despite advancements in hepatitis C virus (HCV) infection treatment, HCV still represents a significant public health burden. Besides progressive hepatic damage, viral persistence has lasting effects on innate and adaptive immune responses. Lack of a complete understanding of the factors driving an effective HCV response contributes to the failure to develop a vaccine for prevention. This study advances the existing knowledge on HCV-specific CD8+ T cells and describes the impact of current or past HCV infection on CD8+ T cells specific for other viruses.

Methods

We used barcoded-dextramers to identify and sort CD8+ T cells specific for HCV, cytomegalovirus, and influenza, and characterized them using single-cell RNA sequencing technology. Our cohort included chronic (cHCV), spontaneously resolved (rHCV), and subjects undergoing direct-acting antiviral (DAA) therapy.

Results

We show that HCV-specific CD8+ T cells have cytotoxic features in patients with cHCV, which is progressively reduced with DAA therapy and persists 12 weeks after treatment completion. We also observe a shift in the CD8+ T cell phenotype on DAA treatment, with decreased effector memory and exhausted cell signatures. In rHCV, we also detected a smaller proportion of effector memory cells compared to cHCV. The proportion of CD8+ exhausted T cells in cHCV and rHCV subjects was comparable. Moreover, we also observed that non-HCV virus-specific CD8+ T cells exhibit robust cytotoxic traits during cHCV infection.

Discussion

Altogether, our findings suggest that cHCV infection promotes cytotoxicity in CD8+ T cells regardless of virus specificity. The immunological changes caused by cHCV infection in CD8+ T cells may contribute to worsening the ongoing hepatic damage caused by HCV infection or exacerbate the immune response to possible co-infections. Our data provide a resource to groups exploring the underlying mechanisms of HCV-specific T cell spontaneous and treatment-induced resolution to inform the development of effective vaccines against HCV infection.

Mechanisms of esophageal cancer metastasis and treatment progress

Esophageal cancer is a prevalent tumor of the digestive tract worldwide. The detection rate of early-stage esophageal cancer is very low, and most patients are diagnosed with metastasis. Metastasis of esophageal cancer mainly includes direct diffusion metastasis, hematogenous metastasis, and lymphatic metastasis. This article reviews the metabolic process of esophageal cancer metastasis and the mechanisms by which M2 macrophages, CAF, regulatory T cells, and their released cytokines, including chemokines, interleukins, and growth factors, form an immune barrier to the anti-tumor immune response mediated by CD8+ T cells, impeding their ability to kill tumor cells during tumor immune escape. The effect of Ferroptosis on the metastasis of esophageal cancer is briefly mentioned. Moreover, the paper also summarizes common drugs and research directions in chemotherapy, immunotherapy, and targeted therapy for advanced metastatic esophageal cancer. This review aims to serve as a foundation for further investigations into the mechanism and management of esophageal cancer metastasis.

Spatial distribution of tumor-infiltrating T cells indicated immune response status under chemoradiotherapy plus PD-1 blockade in esophageal cancer

Background

The spatial distribution of tumor-infiltrating T cells and its dynamics during chemoradiotherapy combined with PD-1 blockade is little known in esophageal squamous cell carcinoma (ESCC).

Methods

We applied the multiplex immunofluorescence method to identify T cells (CD4⁺, CD8⁺ T cells, and their PD-1^- or PD-1⁺ subsets) and myeloid-derived cells (CD11c⁺ dendritic cells, CD68⁺ macrophages, and their PD-L1⁺ subpopulations) in paired tumor biopsies (n = 36) collected at baseline and during combination (40 Gy of radiation) from a phase Ib trial (NCT03671265) of ESCC patients treated with first-line chemoradiotherapy plus anti-PD-1 antibody camrelizumab. We used the FoundationOne CDx assay to evaluate tumor mutational burden (TMB) in baseline tumor biopsies (n = 14). We dynamically assessed the nearest distance and proximity of T-cell subsets to tumor cells under combination and estimated the association between T-cell spatial distribution and combination outcome, myeloid-derived subsets, TMB, and patient baseline characteristics.

Findings

We found that the tumor compartment had lower T-cell subsets than the stromal compartment but maintained a comparable level under combination. Both before and under combination, PD-1^- T cells were located closer than PD-1⁺ T cells to tumor cells; T cells, dendritic cells, and macrophages showed the highest accumulation in the 5-10-μm distance. Higher CD4⁺ T cells in the tumor compartment and a shorter nearest distance of T-cell subsets at baseline predicted poor OS. Higher baseline CD4⁺ T cells, dendritic cells, and macrophages were associated with worse OS in less than 10-μm distance to tumor cells, but related with better OS in the farther distance. Higher on-treatment PD-1-positive-expressed CD4⁺ and CD8⁺ T cells within the 100-μm distance to tumor cells predicted longer OS. T cells, dendritic cells, and macrophages showed a positive spatial correlation. Both high TMB and smoking history were associated with a closer location of T cells to tumor cells at baseline.

Conclusions

We firstly illustrated the T-cell spatial distribution in ESCC. Combining chemoradiotherapy with PD-1 blockade could improve the antitumor immune microenvironment, which benefits the treatment outcome. Further understanding the precision spatiality of tumor-infiltrating T cells would provide new evidence for the tumor immune microenvironment and for the combination treatment with immunotherapy.

PHF6 promotes the progression of endometrial carcinoma by increasing cancer cells growth and decreasing T-cell infiltration

Uterine corpus endometrial carcinoma (UCEC) is the most common cancer of the female reproductive tract. The overall survival of advanced and recurrent UCEC patients is still unfavourable nowadays. It is urgent to find a predictive biomarker and block tumorgenesis at an early stage. Plant homeodomain finger protein 6 (PHF6) is a key player in epigenetic regulation, and its alterations lead to various diseases, including tumours. Here, we found that PHF6 expression was upregulated in UCEC tissues compared with normal tissues. The UCEC patients with high PHF6 expression had poor survival than UCEC patients with low PHF6 expression. PHF6 mutation occurred in 12% of UCEC patients, and PHF6 mutation predicted favourable clinical outcome in UCEC patients. Depletion of PHF6 effectively inhibited HEC-1-A and KLE cell proliferation in vitro and decreased HEC-1-A cell growth in vivo. Furthermore, high PHF6 level indicated a subtype of UCECs characterized by low immune infiltration, such as CD3⁺ T-cell infiltration. While knockdown of PHF6 in endometrial carcinoma cells increased T-cell migration by promoting IL32 production and secretion. Taken together, our findings suggested that PHF6 might play an oncogenic role in UCEC patients. Thus, PHF6 could be a potential biomarker in predicting the prognosis of UCEC patients. Depletion of PHF6 may be a novel therapeutic strategy for UCEC patients.

Immune evasion in esophageal squamous cell cancer: From the perspective of tumor microenvironment

Esophageal cancer (EC) is one of the most life-threatening malignancies worldwide. Esophageal squamous cell carcinoma (ESCC) is the dominant subtype, accounting for approximately 90% of new incident EC each year. Although multidisciplinary treatment strategies have advanced rapidly, patients with ESCC are often diagnosed at advanced stage and the long-term prognosis remains unsatisfactory. In recent decades, immunotherapy, such as immune checkpoint inhibitors (ICIs), tumor vaccines, and chimeric antigen receptor T-cell (CAR-T) therapy, has been successfully used in clinical practice as a novel therapy for treating tumors, bringing new hope to ESCC patients. However, only a small fraction of patients achieved clinical benefits due to primary or acquired resistance. Immune evasion plays a pivotal role in the initiation and progression of ESCC. Therefore, a thorough understanding of the mechanisms by which ESCC cells escape from anti-tumor immunity is necessary for a more effective multidisciplinary treatment strategy. It has been widely recognized that immune evasion is closely associated with the crosstalk between tumor cells and the tumor microenvironment (TME). TME is a dynamic complex and comprehensive system including not only cellular components but also non-cellular components, which influence hallmarks and fates of tumor cells from the outside. Novel immunotherapy targeting tumor-favorable TME represents a promising strategy to achieve better therapeutic responses for patients with ESCC. In this review, we provide an overview of immune evasion in ESCC, mainly focusing on the molecular mechanisms that underlie the role of TME in immune evasion of ESCC. In addition, we also discuss the challenges and opportunities of precision therapy for ESCC by targeting TME.

Diverse and divergent functions of IL-32β and IL-32γ isoforms in the regulation of malignant pleural mesothelioma cell growth and the production of VEGF-A and CXCL8

In this study, we sought to elucidate the roles of the interleukin (IL)-32β and IL-32γ in mesothelioma cell growth, and vascular endothelial growth factor (VEGF)-A and C-X-C motif chemokine ligand 8 (CXCL8) expression. IL-32 elicited a growth-promoting effect against one of the six mesotheliomas lines and exerted diverse regulatory functions in VEGF-A and CXCL8 secretion from mesotheliomas stimulated with or without IL-17A. Retroviral-mediated transduction of mesothelioma lines with IL-32γ resulted in enhanced IL-32β expression, which facilitated or suppressed the in vitro growth, and VEGF-A and CXCL8 expression. Overexpressed IL-32β-augmented growth and VEGF-A and CXCL8 production were mainly mediated through the phosphatidylinositol-3 kinase (PI3K) signaling pathway. On the other hand, overexpressed IL-32β-deceased growth was mediated through mitogen-activated protein kinase (MAPK) pathway. NCI-H2373IL-32γ tumors grew faster than NCI-H2373Neo tumors in a xenograft model, which was associated with increased vascularity. These findings indicate that IL-32 are involved in the regulation of growth and angiogenic factor production in mesotheliomas.

Down-regulation of IL-32γ expression reduces killing effect of natural killer cells on esophageal carcinoma cells

BACKGROUND

Interleukin (IL)-32γ is highly expressed in activated natural killer (NK) cells in esophageal cancer. However, it is not clear whether the expression level of IL-32γ in NK cells affects their killing effect on esophageal cancer cells.

AIM

To investigate the role of IL-32γ in the anti-tumor effect of NK cells in esophageal cancer.

METHODS

After transfecting NK-92 cells with shRNA targeting IL-32γ (shIL-32γ), the NK-92 cells were co-cultured with esophageal cancer cells EC9706 and TE-1, respectively. EC9706 and TE-1 cells were then collected; cell viability was measured by cell counting kit-8 (CCK-8) assay, cell proliferation was detected by 5-ethynyl-2'-deoxyuridine (EDU) assay, cell apoptosis was detected by flow cytometry, and the expression of apoptosis-related proteins B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X (Bax), cleaved cysteine-containing aspartate-specific proteases 3 (caspase 3), tumor necrosis factor receptor superfamily member 6 (FAS), death receptor 3 (DR3), and tumor necrosis factor receptor 2 (TNFR2) was detected by Western blot.

RESULTS

After IL-32γ deletion in NK-92 cells, the cell viability and the EDU positive cells in EC9706 and TE-1 cells in the co-culture system were increased (P < 0.01), the expression level of Bcl-2 was increased (P < 0.01), and the expression levels of Bax, cleaved-caspase 3, FAS, DR3, and TNFR2 were all decreased (P < 0.01).

CONCLUSION

Knockdown of IL-32γ attenuates the anti-tumor effect of NK-92 cells, which may be related to the inhibition of death receptor expression and caspase-3 activation in esophageal cancer cells.

Phenotype, Function, and Clinical Significance of CD26+ and CD161+Tregs in Splenic Marginal Zone Lymphoma

PURPOSE

Regulatory T-cells (Treg) are essential to Tregs homeostasis and modulate the antitumor immune response in patients with lymphoma. However, the biology and prognostic impact of Tregs in splenic marginal zone lymphoma (SMZL) have not been studied.

EXPERIMENTAL DESIGN

Biopsy specimens from 24 patients with SMZL and 12 reactive spleens (rSP) from individuals without lymphoma were analyzed by using CITE-seq (cellular indexing of transcriptomes and epitopes by sequencing), CyTOF (mass cytometry) analysis, and flow cytometry to explore the phenotype, transcriptomic profile, and clinical significance of intratumoral Tregs and their subsets. The biological characteristics and cell signaling pathways of intratumoral Treg subsets were confirmed by in vitro functional assays.

RESULTS

We found that Tregs are more abundant in SMZL patients' spleens than rSP, and Tregs from patients with SMZL and rSP can be separated into CD161+Treg and CD26+Treg subsets. CD161+Tregs are increased in SMZL but have dysregulated immune function. We found that CD161+Treg and CD26+Tregs have unique gene expression and phenotypic profiles and are differentially correlated with patient outcomes. Specifically, increased CD161+Tregs are significantly associated with a favorable prognosis in patients with SMZL, whereas CD26+Tregs are associated with a poor prognosis. Furthermore, activation of the IL2/STAT5 pathway contributes to the induction of CD26+Tregs and can be reversed by STAT5 inhibition.

CONCLUSIONS

IL2/STAT5-mediated expansion of CD26+Tregs contributes to a poor clinical outcome in SMZL and may represent a therapeutic opportunity in this disease.

Applications and Achievements of Single-Cell Sequencing in Gastrointestinal Cancer

Gastrointestinal cancer represents a public health concern that seriously endangers human health. The emerging single-cell sequencing (SCS) technologies are different from the large-scale sequencing technologies which provide inaccurate data. SCS is a powerful tool for deciphering the single-cell resolutions of cellular and molecular landscapes, revealing the features of single-cell genomes, transcriptomes, and epigenomes. Recently, SCS has been applied in the field of gastrointestinal cancer research for clarifying the origin and heterogeneity of gastrointestinal cancer, acquiring micro-environmental information, and improving diagnostic and treatment methods. This review outlines the applications of SCS in gastrointestinal cancer research and summarizes the most recent advances in the field.

A Paradoxical Effect of Interleukin-32 Isoforms on Cancer

IL-32 plays a contradictory role such as tumor proliferation or suppressor in cancer development depending on the cancer type. In most cancers, it was found that the high expression of IL-32 was associated with more proliferative and progression of cancer. However, studying the isoforms of IL-32 cytokine has placed its paradoxical role into a wide range of functions based on its dominant isoform and surrounding environment. IL-32β, for example, was found mostly in different types of cancer and associated with cancer expansion. This observation is legitimate since cancer exhibits some hypoxic environment and IL-32β was known to be induced under hypoxic conditions. However, IL-32θ interacts directly with protein kinase C-δ reducing NF-κB and STAT3 levels to inhibit epithelial-mesenchymal transition (EMT). This effect could explain the different functions of IL-32 isoforms in cancer. However, pro- or antitumor activity which is dependant on obesity, gender, and age as it relates to IL-32 has yet to be studied. Obesity-related IL-32 regulation indicated the role of IL-32 in cancer metabolism and inflammation. IL-32-specific direction in cancer therapy is difficult to conclude. In this review, we address that the paradoxical effect of IL-32 on cancer is attributed to the dominant isoform, cancer type, tumor microenvironment, and genetic background. IL-32 seems to have a contradictory role in cancer. However, investigating multiple IL-32 isoforms could explain this doubt and bring us closer to using them in therapy.

Extracellular vesicle IL-32 promotes the M2 macrophage polarization and metastasis of esophageal squamous cell carcinoma via FAK/STAT3 pathway

Background

Metastasis is the leading cause of mortality in human cancers, including esophageal squamous cell carcinoma (ESCC). As a pro-inflammatory cytokine, IL-32 was reported to be a poor prognostic factor in many cancers. However, the role of IL-32 in ESCC metastasis remains unknown.

Methods

ESCC cells with ectopic expression or knockdown of IL-32 were established and their effects on cell motility were detected. Ultracentrifugation, Transmission electron microscopy and Western blot were used to verify the existence of extracellular vesicle IL-32 (EV-IL-32). Coculture assay, immunofluorescence, flow cytometry, and in vivo lung metastasis model were performed to identify how EV-IL-32 regulated the crosstalk between ESCC cells and macrophages.

Results

Here, we found that IL-32 was overexpressed and positively correlated to lymph node metastasis of ESCC. IL-32 was significantly higher in the tumor nest compared with the non-cancerous tissue. We found that IL-32β was the main isoform and loaded in EV derived from ESCC cells. The shuttling of EV-IL-32 derived from ESCC cells into macrophages could promote the polarization of M2 macrophages via FAK-STAT3 pathway. IL-32 overexpression facilitated lung metastasis and was positively correlated with the proportion of M2 macrophages in tumor microenvironment.

Conclusions

Taken together, our results indicated that EV-IL-32 derived from ESCC cell line could be internalized by macrophages and lead to M2 macrophage polarization via FAK-STAT3 pathway, thus promoting the metastasis of ESCC. These findings indicated that IL-32 could serve as a potential therapeutic target in patients with ESCC.

Supplementary information

The online version contains supplementary material available at 10.1186/s13046-022-02348-8.