Cytokines chattering in pancreatic ductal adenocarcinoma tumor microenvironment

Leptin decreases Th17/Treg ratio to facilitate neuroblastoma via inhibiting long-chain fatty acid catabolism in tumor cells

The exploration of therapeutic targets in neuroblastoma (NB), which needs more attempts, can benefit patients with high-risk NB. Based on metabolomic and transcriptomic data in mediastinal NB tissues, we found that the content of long-chain acylcarnitine (LCAC) was increased and positively associated with leptin expression in advanced NB. Leptin over-expression forced naïve CD4+ T cells to differentiate into Treg cells instead of Th17 cells, which benefited from NB cell proliferation, migration, and drug resistance. Mechanically, leptin in NB cells blunted the activity of carnitine palmitoyltransferase 2 (CPT2), the key enzyme for LCAC catabolism, by inhibiting sirtuin 3-mediated CPT2 deacetylation, which depresses oxidative phosphorylation (OXPHOS) for energy supply and increases lactic acid (LA) production from glycolysis to modulate CD4+ T cell differentiation. These findings highlight that excess leptin contributes to lipid metabolism dysfunction in NB cells and subsequently misdirects CD4+ T cell differentiation in tumor micro-environment (TME), indicating that targeting leptin could be a therapeutic strategy for retarding NB progression.

Paracrine regulation of pancreatic cancer cell response to chemotherapy by GLI2-Collagen I signaling

Despite the well described role of non-cellular components of the tumor microenvironment (TME) in regulating tumor growth, the molecular events dictating expression and biological functions of key components of the TME remain elusive. Here, using pancreatic cancer (PC) models, we describe a novel mechanism through which the zinc finger transcription factor GLI2 in cancer associated fibroblasts (CAFs) induces expression of COL1A1, which is a major component of Type I Collagen, the most abundant collagen variant in the tumor milieu. Bulk and single nuclei RNA-Seq showed that GLI2 expression in CAF strongly correlates with COL1A1 expression levels, fibrosis, and CAF activation. ChIP-qPCR and expression studies of the PC matrisome identified COL1A1 as the direct target of GLI2 in CAFs. We also provide evidence that GLI2 is an effector that mediates COL1A1 induction by transforming growth factor β1 (TGFβ1). RNA-Seq analysis of PC cells treated with Type I Collagen revealed enrichment of chemotherapeutic gene expression profiles, which includes irinotecan resistance signature. Viability studies confirmed that Type I Collagen promotes irinotecan resistance in PC cells. Altogether, our results uncover a novel role for the TGFβ1-GLI2 axis within CAFs to modulate Type I Collagen expression and promote chemoresistance in PC cells. Together, our findings help increase the understanding of the complex molecular network operating in the TME.

Paricalcitol plus hydroxychloroquine enhances gemcitabine activity and induces mesenchymal to epithelial transition in pancreatic ductal adenocarcinoma: A single cell RNA-seq analysis

Epithelial-mesenchymal transition (EMT) describes a process by which epithelial cells acquire mesenchymal properties associated with increased migration, invasion, and resistance to therapy. In pancreatic ductal adenocarcinoma (PDAC), targeting the molecular and intercellular communication pathways that drive EMT represents a promising therapeutic strategy. Here, we investigate the effects of combined treatment with gemcitabine (G), paricalcitol (P), and hydroxychloroquine (GPH) in KPC-Luc orthotopic mouse models of PDAC, using single-cell RNA sequencing (scRNA-seq), high-dimensional weighted gene co-expression network analysis (hdWGCNA), and cell-cell communication analysis. GPH treatment reduces EMT, which is associated with the downregulation of the essential gene fibronectin (Fn1). Collagen and Fn1 pathways co-expression decreases in GPH-treated KPC-Luc tumors. Cancer-associated fibroblasts (CAFs) appear dominant in collagen signaling, whereas macrophages mediate Fn1 signaling. GPH treatment reduces the expression interaction strength between ligands and receptors (collagen-integrin and Fn1-Cd44 or Fn1-Sdc4) compared to sham, PH, and G. Altogether, this study presents a comprehensive single-cell resolution map of the molecular and cellular mechanisms by which GPH treatment impairs EMT in PDAC, identifying potential therapeutic targets within the fibronectin and collagen signaling axes.

Immunosuppressive tumor microenvironment in pancreatic cancer: mechanisms and therapeutic targets

Pancreatic cancer is projected to become the second leading cause of cancer-related death by 2030. Conventional interventions including surgery, radiotherapy, and chemotherapy provide only modest survival benefits, underscoring an urgent need for more effective therapies. Although immunotherapy has revolutionized the management of several solid tumors, its clinical benefit in pancreatic cancer has so far been disappointing. Mounting evidence indicates that a highly immunosuppressive tumor microenvironment (TME), dominated by tumor-associated macrophages (TAMs), myeloid-derived suppressor cells (MDSCs), and regulatory T cells (Tregs), drives immune evasion, tumor progression, metastasis, and chemoresistance through complex cytokine and chemokine networks. This review summarizes current knowledge of these immunosuppressive mechanisms and provides emerging strategies aimed at re-educating or depleting these cellular constituents to enhance the efficacy of immunotherapy in pancreatic cancer.

Comprehensive Integrated Analysis Reveals the Spatiotemporal Microevolution of Cancer Cells in Patients with Bone-Metastatic Prostate Cancer

Background/Objectives: Bone metastasis is a frequent and life-threatening event in advanced cancers, affecting up to 70-85% of prostate cancer patients. Understanding the cellular and molecular mechanisms underlying bone metastasis is essential for developing targeted therapies. This study aimed to systematically characterize the heterogeneity and microenvironmental adaptation of prostate cancer bone metastases using single-cell transcriptomics. Methods: We integrated the largest single-cell transcriptome dataset to date, encompassing 124 samples from primary prostate tumors, various bone metastatic sites, and non-malignant tissues (e.g., benign prostatic hyperplasia, normal bone marrow). After quality control, 602,497 high-quality single-cell transcriptomes were analyzed. We employed unsupervised clustering, gene expression profiling, mutation analysis, and metabolic pathway reconstruction to characterize cancer cell subtypes and tumor microenvironmental remodeling. Results: Cancer epithelial cells dominated the tumor microenvironment but exhibited pronounced heterogeneity, posing challenges for conventional clustering methods. By integrating genetic and metabolic features, we revealed key evolutionary trajectories of epithelial cancer cells during metastasis. Notably, we identified a novel epithelial subpopulation, NEndoCs, characterized by unique differentiation patterns and distinct spatial distribution across metastatic niches. We also observed significant metabolic reprogramming and recurrent mutations linked to prostate-to-bone microenvironmental transitions. Conclusions: This study comprehensively elucidates the mutation patterns, metabolic reprogramming, and microenvironment adaptation mechanisms of bone metastasis in prostate cancer, providing key molecular targets and clinical strategies for the precise treatment of bone metastatic prostate cancer.

The role of IL‑17, IFN‑γ, 4‑1BBL and tumour‑infiltrating lymphocytes in the occurrence, development and prognosis of pancreatic cancer

Immunotherapy has made progress in the treatment of tumours; however, in patients with pancreatic cancer, immunotherapy has not achieved effective results. The present study investigated changes in the immune microenvironment during tumour development and progression, and the relationship between the immune microenvironment and prognosis, to clarify the mechanism of immune escape in pancreatic cancer. A total of 40 patients with pancreatic cancer (including 22 with stage I-II disease and 18 with stage III-IV disease) and 20 patients with chronic pancreatitis were included in the present study. The expression of CD3, CD4, CD8, CD56, IFN-γ, IL-17 and 4-1BBL was assessed by immunohistochemistry, and the mRNA expression levels were detected by reverse transcription-quantitative PCR (RT-qPCR). The clinicopathological characteristics and prognoses of patients with pancreatic cancer were analysed to further explore the role of IL-17, IFN-γ, 4-1BBL and tumour-infiltrating lymphocytes in pancreatic cancer. Notably, the expression levels of CD3, CD8, CD56, IFN-γ and 4-1BBL in patients with stages I-II and III-IV cancer were lower than those in patients with chronic pancreatitis (P<0.05), especially in patients with stage III-IV cancer (P<0.05). In addition, the expression of IL-17 in patients with stages I-II and III-IV cancer was greater than in patients with chronic pancreatitis (P<0.05), especially in patients with stage III-IV cancer (P<0.05). The RT-qPCR results regarding CD3, CD4, CD8, CD56, IFN-γ and IL-17 were almost the same as those obtained from immunohistochemical analysis; however, the mRNA expression levels of 4-1BBL were not significantly different between stages I-II and III-IV. Furthermore, patients with pancreatic cancer with higher expression levels of CD3, CD8, CD56, IFN-γ and 4-1BBL exhibited longer survival, whereas those with higher expression of IL-17 had a shorter survival time. The expression levels of CD3, CD8, CD56, cytokines IL-17 and IFN-γ, and costimulatory molecule 4-1BBL were revealed to be related to the degree of differentiation, Tumour-Node-Metastasis staging and the prognosis of pancreatic cancer, and may serve as novel immunological indicators for evaluating the condition and treatment effectiveness in patients with pancreatic cancer.

Neuregulin 4: A Key Regulator in Suppressing Lung Adenocarcinoma Progression

INTRODUCTION

Lung adenocarcinoma remains a significant public health concern, necessitating novel therapeutic approaches. Neuregulin 4 (NRG4), a secreted protein of the epidermal growth factor family, is recognized for its roles in metabolic regulation and anti-inflammatory processes, suggesting therapeutic potential across various diseases. However, its specific function in lung adenocarcinoma progression is not well elucidated. Methods: We utilized The Cancer Genome Atlas (TCGA) database to examine correlations between NRG4 expression, epithelial-mesenchymal transition (EMT)-related genes, and overall survival in lung adenocarcinoma patients. The effects of recombinant NRG4 (rNRG4) on cell migration and cancer progression were evaluated through Transwell assays, quantitative PCR, immunofluorescence, and immunohistochemistry. Additionally, a lung adenocarcinoma mouse model (LLC-bearing) was employed to assess the impact of rNRG4 on tumor progression. RNA sequencing of primary tumors was conducted to explore the functional mechanisms underlying rNRG4's effects. Results: Our analysis revealed that NRG4 expression inversely correlates with key molecules involved in cell migration and EMT in lung adenocarcinoma. Treatment with rNRG4 significantly inhibited cell proliferation, migration, EMT, and tumor growth in both in vitro and in vivo models. RNA sequencing indicated that rNRG4 downregulates extracellular matrix (ECM) proteins, and online database analyses confirmed that higher NRG4 expression is associated with reduced ECM levels and improved patient survival. Conclusions: These findings suggest that NRG4 serves as a potential candidate for further investigation for lung adenocarcinoma.

Reprograming immunosuppressive microenvironment by eIF4G1 targeting to eradicate pancreatic ductal adenocarcinoma

Current therapies against pancreatic ductal adenocarcinoma (PDAC) have limited clinical benefits owing to tumor heterogeneity and their unique immunosuppressive microenvironments. The eukaryotic initiation factor (eIF) 4F complex is involved in regulating translation and various downstream carcinogenic signaling pathways. We report that eIF4G1, one of the subunits of eIF4F, is overexpressed in cancer cells and cancer-associated fibroblasts, and this correlates with poor prognosis in patients with PDAC. In PDAC mice, eIF4G1 inhibition limits tumor progression and prolongs overall survival, especially when combined with PD1/PDL1 antagonists and gemcitabine. Mechanistically, eIF4G1 inhibition hinders the production of cytokines and chemokines that promote fibrosis and inhibit cytotoxic T cell chemotaxis. Moreover, eIF4G1 inhibition impairs integrinβ1 protein translation and exerts tumor suppression effects through the FAK-ERK/AKT signaling pathway. These findings highlight the effects of eIF4G1 on tumor immune dependence and independence and identify eIF4G1 as a promising therapeutic target for PDAC.

The crucial prognostic signaling pathways of pancreatic ductal adenocarcinoma were identified by single-cell and bulk RNA sequencing data

Pancreatic ductal adenocarcinoma (PDAC) is a malignant tumor with poor prognosis and high mortality. Although a large number of studies have explored its potential prognostic markers using traditional RNA sequencing (RNA-Seq) data, they have not achieved good prediction effect. In order to explore the possible prognostic signaling pathways leading to the difference in prognosis, we identified differentially expressed genes from one scRNA-seq cohort and four GEO cohorts, respectively. Then Cox and Lasso regression analysis showed that 12 genes were independent prognostic factors for PDAC. AUC and calibration curve analysis showed that the prognostic model had good discrimination and calibration. Compared with the low-risk group, the high-risk group had a higher proportion of gene mutations than the low-risk group. Immune infiltration analysis revealed differences in macrophages and monocytes between the two groups. Prognosis related genes were mainly distributed in fibroblasts, macrophages and type 2 ducts. The results of cell communication analysis showed that there was a strong communication between cancer-associated fibroblasts (CAF) and type 2 ductal cells, and collagen formation was the main interaction pathway.

Targeting the Cascade Amplification of Macrophage Colony-stimulating Factor to Alleviate the Immunosuppressive Effects Following Radiotherapy

Radiotherapy (RT) serves as the primary treatment for solid tumors. Its potential to incite an immune response against tumors both locally and distally profoundly impacts clinical outcomes. However, RT may also promote the accumulation of immunosuppressive cytokines and immunosuppressive cells, greatly impeding the activation of antitumor immune responses and substantially limiting the effectiveness of RT. Therefore, regulating post-RT immunosuppression to steer the immune milieu toward heightened activation potentially enhances RT's therapeutic potential. Cytokines, potent orchestrators of diverse cellular responses, play a pivotal role in regulating this immunosuppressive response. Identifying and promptly neutralizing early released immunosuppressive cytokines are a crucial development in augmenting RT's immunomodulatory effects. To this end, we conducted a screen of immunosuppressive cytokines following RT and identified macrophage colony-stimulating factor (MCSF) as an early up-regulated and persistent immune suppressor. Single-cell sequencing revealed that the main source of up-regulated MCSF derived from tumor cells. Mechanistic exploration revealed that irradiation-dependent phosphorylation of the p65 protein facilitated its binding to the MCSF gene promoter, enhancing transcription. Knockdown and chemical inhibitor experiments conclusively demonstrated that suppressing tumor cell-derived MCSF amplifies RT's immune-activating effects, with optimal results achieved by early MCSF blockade after irradiation. Additionally, we validated that MCSF acted on macrophages, inducing the secretion of a large number of inhibitory cytokines. In summary, we propose a novel approach to enhance the immune activation effects of RT by blocking the MCSF-CSF1R signaling pathway early after irradiation.

Poly(phenylalanine) and poly(3,4-dihydroxy-L-phenylalanine): Promising biomedical materials for building stimuli-responsive nanocarriers

Cancer is a serious threat to human health because of its high annual mortality rate. It has attracted significant attention in healthcare, and identifying effective strategies for the treatment and relief of cancer pain requires urgency. Drug delivery systems (DDSs) offer the advantages of excellent efficacy, low cost, and low toxicity for targeting drugs to tumor sites. In recent decades, copolymer carriers based on poly(phenylalanine) (PPhe) and poly(3,4-dihydroxy-L-phenylalanine) (PDopa) have been extensively investigated owing to their good biocompatibility, biodegradability, and controllable stimulus responsiveness, which have resulted in DDSs with loading and targeted delivery capabilities. In this review, we introduce the synthesis of PPhe and PDopa, highlighting the latest proposed synthetic routes and comparing the differences in drug delivery between PPhe and PDopa. Subsequently, we summarize the various applications of PPhe and PDopa in nanoscale-targeted DDSs, providing a comprehensive analysis of the drug release behavior based on different stimulus-responsive carriers using these two materials. In the end, we discuss the challenges and prospects of polypeptide-based DDSs in the field of cancer therapy, aiming to promote their further development to meet the growing demands for treatment.

Decoding the spatiotemporal heterogeneity of tumor-associated macrophages

Tumor-associated macrophages (TAMs) are pivotal in cancer progression, influencing tumor growth, angiogenesis, and immune evasion. This review explores the spatial and temporal heterogeneity of TAMs within the tumor microenvironment (TME), highlighting their diverse subtypes, origins, and functions. Advanced technologies such as single-cell sequencing and spatial multi-omics have elucidated the intricate interactions between TAMs and other TME components, revealing the mechanisms behind their recruitment, polarization, and distribution. Key findings demonstrate that TAMs support tumor vascularization, promote epithelial-mesenchymal transition (EMT), and modulate extracellular matrix (ECM) remodeling, etc., thereby enhancing tumor invasiveness and metastasis. Understanding these complex dynamics offers new therapeutic targets for disrupting TAM-mediated pathways and overcoming drug resistance. This review underscores the potential of targeting TAMs to develop innovative cancer therapies, emphasizing the need for further research into their spatial characteristics and functional roles within the TME.

Development of human pancreatic cancer avatars as a model for dynamic immune landscape profiling and personalized therapy

Pancreatic ductal adenocarcinoma (PDAC) is the most common form of pancreatic cancer, a disease with dismal overall survival. Advances in treatment are hindered by a lack of preclinical models. Here, we show how a personalized organotypic "avatar" created from resected tissue allows spatial and temporal reporting on a complete in situ tumor microenvironment and mirrors clinical responses. Our perfusion culture method extends tumor slice viability, maintaining stable tumor content, metabolism, stromal composition, and immune cell populations for 12 days. Using multiplexed immunofluorescence and spatial transcriptomics, we identify immune neighborhoods and potential for immunotherapy. We used avatars to assess the impact of a preclinically validated metabolic therapy and show recovery of stromal and immune phenotypes and tumor redifferentiation. To determine clinical relevance, we monitored avatar response to gemcitabine treatment and identify a patient avatar-predictable response from clinical follow-up. Thus, avatars provide valuable information for syngeneic testing of therapeutics and a truly personalized therapeutic assessment platform for patients.

Ubiquitin ligase TRIM15 promotes the progression of pancreatic cancer via the upregulation of the IGF2BP2-TLR4 axis

BACKGROUND

The tripartite motif family, predominantly characterized by its E3 ubiquitin ligase activities, is involved in various cellular processes including signal transduction, apoptosis and autophagy, protein quality control, immune regulation, and carcinogenesis. Tripartite Motif Containing 15 (TRIM15) plays an important role in melanoma progression through extracellular signal-regulated kinase activation; however, data on its role in pancreatic tumors remain lacking. We previously demonstrated that TRIM15 targeted lipid synthesis and metabolism in pancreatic cancer; however, other specific regulatory mechanisms remain elusive.

METHODS

We used transcriptomics and proteomics, conducted a series of phenotypic experiments, and used a mouse orthotopic transplantation model to study the specific mechanism of TRIM15 in pancreatic cancer in vitro and in vivo.

RESULTS

TRIM15 overexpression promoted the progression of pancreatic cancer by upregulating the toll-like receptor 4. The TRIM15 binding protein, IGF2BP2, could combine with TLR4 to inhibit its mRNA degradation. Furthermore, the ubiquitin level of IGF2BP2 was positively correlated with TRIM15.

CONCLUSIONS

TRIM15 could ubiquitinate IGF2BP2 to enhance the function of phase separation and the maintenance of mRNA stability of TLR4. TRIM15 is a potential therapeutic target against pancreatic cancer.

Tumor Stroma as a Therapeutic Target for Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis owing to its desmoplastic stroma. Therefore, therapeutic strategies targeting this tumor stroma should be developed. In this study, we describe the heterogeneity of cancer-associated fibroblasts (CAFs) and their diverse roles in the progression, immune evasion, and resistance to treatment of PDAC. We subclassified the spatial distribution and functional activity of CAFs to highlight their effects on prognosis and drug delivery. Extracellular matrix components such as collagen and hyaluronan are described for their roles in tumor behavior and treatment outcomes, implying their potential as therapeutic targets. We also discussed the roles of extracellular matrix (ECM) including matrix metalloproteinases and tissue inhibitors in PDAC progression. Finally, we explored the role of the adaptive and innate immune systems in shaping the PDAC microenvironment and potential therapeutic strategies, with a focus on immune cell subsets, cytokines, and immunosuppressive mechanisms. These insights provide a comprehensive understanding of PDAC and pave the way for the development of prognostic markers and therapeutic interventions.

Interferon-γ in the tumor microenvironment promotes the expression of B7H4 in colorectal cancer cells, thereby inhibiting cytotoxic T cells

The bioactivity of interferon-γ (IFN-γ) in cancer cells in the tumor microenvironment (TME) is not well understood in the current immunotherapy era. We found that IFN-γ has an immunosuppressive effect on colorectal cancer (CRC) cells. The tumor volume in immunocompetent mice was significantly increased after subcutaneous implantation of murine CRC cells followed by IFN-γ stimulation, and RNA sequencing showed high expression of B7 homologous protein 4 (B7H4) in these tumors. B7H4 promotes CRC cell growth by inhibiting the release of granzyme B (GzmB) from CD8+ T cells and accelerating apoptosis in CD8+ T cells. Furthermore, interferon regulatory factor 1 (IRF1), which binds to the B7H4 promoter, is positively associated with IFN-γ stimulation-induced expression of B7H4. The clinical outcome of patients with CRC was negatively related to the high expression of B7H4 in cancer cells or low expression of CD8 in the microenvironment. Therefore, B7H4 is a biomarker of poor prognosis in CRC patients, and interference with the IFN-γ/IRF1/B7H4 axis might be a novel immunotherapeutic method to restore the cytotoxic killing of CRC cells.

Prognostic value of RRM1 and its effect on chemoresistance in pancreatic cancer

PURPOSE

Pancreatic cancer (PC) remains a lethal disease, and gemcitabine resistance is prevalent. However, the biomarkers suggestive of gemcitabine resistance remain unclear.

METHODS

Bioinformatic tools identified ribonucleotide reductase catalytic subunit M1 (RRM1) in gemcitabine-related datasets. A cox regression model revealed the predictive value of RRM1 with clinical features. An external clinical cohort confirmed the prognostic value of RRM1. RRM1 expression was validated in gemcitabine-resistant cells in vitro and in orthotopic PC model. CCK8, flow cytometry, transwell migration, and invasion assays were used to explore the effect of RRM1 on gemcitabine-resistant cells. The CIBERSORT algorithm investigated the impact of RRM1 on immune infiltration.

RESULTS

The constructed nomogram based on RRM1 effectively predicted prognosis and was further validated. Moreover, patients with higher RRM1 had shorter overall survival. RRM1 expression was significantly higher in PC tissue and gemcitabine-resistant cells in vitro and in vivo. RRM1 knockdown reversed gemcitabine resistance, inhibited migration and invasion. The infiltration levels of CD4 + T cells, CD8 + T cells, neutrophils, and plasma cells correlated markedly with RRM1 expression, and communication between tumor and immune cells probably depends on NF-κB/mTOR signaling.

CONCLUSION

RRM1 may be a potential marker for prognosis and a target marker for gemcitabine resistance in PC.

Suppression of the antitumoral activity of natural killer cells under indirect coculture with cancer-associated fibroblasts in a pancreatic TIME-on-chip model

BACKGROUND

Recently, natural killer (NK) cells emerged as a treatment option for various solid tumors. However, the immunosuppressive tumor immune microenvironment (TIME) can reduce the cytotoxic ability of NK cells in pancreatic ductal adenocarcinoma. Cancer-associated fibroblasts within the tumor stroma can suppress immune surveillance by dysregulating factors involved in the cellular activity of NK cells. Herein, the effect of activated pancreatic stellate cells (aPSCs) on NK cell-mediated anticancer efficacy under three-dimensional (3D) coculture conditions was investigated.

METHODS

3D cocultures of PANC-1 tumor spheroids (TSs) with aPSCs and NK-92 cells in a collagen matrix were optimized to identify the occurring cellular interactions and differential cytokine profiles in conditioned media using microchannel chips. PANC-1 TSs and aPSCs were indirectly cocultured, whereas NK-92 cells were allowed to infiltrate the TS channel using convective medium flow.

RESULTS

Coculture with aPSCs promoted PANC-1 TSs growth and suppressed the antitumor cytotoxic effects of NK-92 cells. Mutual inhibition of cellular activity without compromising migration ability was observed between aPSCs and NK-92 cells. Moreover, the reduced killing activity of NK-92 cells was found to be related with reduced granzyme B expression in NK cells.

CONCLUSIONS

Herein, a novel TIME-on-chip model based on the coculture of PANC-1 TSs, aPSCs, and NK-92 cells was described. This model may be useful for studying the detailed mechanisms underlying NK cells dysregulation and for exploring future therapeutic interventions to restore NK cell activity in the tumor microenvironment.

Three-in-One Oncolytic Adenovirus System Initiates a Synergetic Photodynamic Immunotherapy in Immune-Suppressive Cholangiocarcinoma

Although photodynamic immunotherapy has been promoted in the clinical practice of cholangiocarcinoma, the insensitivity to photodynamic immunotherapy remains to be a great problem. This can be largely attributed to an immune-suppressive tumor microenvironment (TME) manifested as immature myeloid cells and exhausted cytotoxic T lymphocytes. Here, a three-in-one oncolytic adenovirus system PEG-PEI-Adv-Catalase-KillerRed (p-Adv-CAT-KR) has been constructed to multiply, initiate, and enhance immune responses in photodynamic immunotherapy, using genetically-engineered KillerRed as photosensitizer, catalase as in situ oxygen-supplying mediator, and adenovirus as immunostimulatory bio-reproducible carrier. Meanwhile, PEG-PEI is applied to protect adenovirus from circulating immune attack. The administration of p-Adv-CAT-KR induces increased antigen presenting cells, elevated T cell infiltrations, and reduced tumor burden. Further investigation into underlying mechanism indicates that hypoxia inducible factor 1 subunit alpha (Hif-1α) and its downstream PD-1/PD-L1 pathway contribute to the transformation of immune-suppressive TME in cholangiocarcinoma. Collectively, the combination of KillerRed, catalase, and adenovirus brings about multi-amplified antitumor photo-immunity and has the potential to be an effective immunotherapeutic strategy for cholangiocarcinoma.

Characterization of 3D heterocellular spheroids of pancreatic ductal adenocarcinoma for the study of cell interactions in the tumor immune microenvironment

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest malignancies nowadays. The available chemo- and immunotherapies are often ineffective in treating PDAC due to its immunosuppressive and highly desmoplastic tumor immune microenvironment (TIME), which is hardly reproduced in the existing preclinical models. The PDAC TIME results from a peculiar spatial organization between different cell types. For this reason, developing new human models recapitulating the tissue organization and cell heterogeneity of PDAC is highly desirable. We developed human 3D heterocellular tumor spheroids of PDAC formed by cancer cells, endothelial cells, pancreatic stellate cells (PSC), and monocytes. As a control, we formed spheroids using immortalized epithelial pancreatic ductal cells (non-cancerous spheroids) with cellular heterogeneity similar to the tumor spheroids. Normal spheroids containing endothelial cells formed a complex 3D endothelial network significantly compromised in tumor spheroids. Monocyte/macrophages within the 4-culture tumor spheroids were characterized by a higher expression of CD163, CD206, PD-L1, and CD40 than those in the non-cancerous spheroids suggesting their differentiation towards an immunosuppressive phenotype. The heterocellular tumor spheroids presented a hypoxic core populated with PSC and monocytes/macrophages. The 4-culture tumor spheroids were characterized by spatial proximity of PSC and monocytes to the endothelial cells and a cytokine signature with increased concentrations of CXCL10, CCL2, and IL-6, which have been observed in PDAC patients and associated with poor survival. Further, 4-culture tumor spheroids decreased the concentrations of T-cell chemoattracting cytokines, i.e., CCL4, CCL5, and CXCL9, when compared with the non-cancerous spheroids, revealing a critical immunosuppressive feature of the different types of cells forming the tumor spheroids. Our results showed that the 4-culture tumor spheroids better resembled some critical features of patients' PDAC TIME than monoculture tumor spheroids. Using the proposed human 3D spheroid model for therapy testing at the preclinical stage may reveal pitfalls of chemo- and immuno-therapies to help the development of better anti-tumor therapies.

Epigenetic regulation of cancer-associated fibroblast heterogeneity

Cancer-associated fibroblasts (CAFs), a significant component of the tumor microenvironment (TME), contribute to cancer progression through the secretion of extracellular matrix (ECM), growth factors, and metabolites. It is now well recognized that CAFs are a heterogenous population with ablation experiments leading to reduced tumor growth and single-cell RNA sequencing demonstrating CAF subgroups. CAFs lack genetic mutations yet substantially differ from their normal stromal precursors. Here, we review epigenetic changes in CAF maturation, focusing on DNA methylation and histone modifications. DNA methylation changes in CAFs have been demonstrated globally, while roles of methylation at specific genes affect tumor growth. Further, loss of CAF histone methylation and gain of histone acetylation has been shown to promote CAF activation and tumor promotion. Many CAF activating factors, such as transforming growth factor β (TGFβ), lead to these epigenetic changes. MicroRNAs (miRNAs) serve as targets and orchestrators of epigenetic modifications that influence gene expression. Bromodomain and extra-terminal domain (BET), an epigenetic reader, recognizes histone acetylation and activates the transcription of genes leading to the pro-tumor phenotype of CAFs.

Muc4 loss mitigates epidermal growth factor receptor activity essential for PDAC tumorigenesis

Mucin4 (MUC4) appears early during pancreatic intraepithelial neoplasia-1 (PanIN1), coinciding with the expression of epidermal growth factor receptor-1 (EGFR). The EGFR signaling is required for the onset of Kras-driven pancreatic ductal adenocarcinoma (PDAC); however, the players and mechanisms involved in sustained EGFR signaling in early PanIN lesions remain elusive. We generated a unique Esai-CRISPR-based Muc4 conditional knockout murine model to evaluate its effect on PDAC pathology. The Muc4 depletion in the autochthonous murine model carrying K-ras and p53 mutations (K-rasG12D; TP53R172H; Pdx-1cre, KPC) to generate the KPCM4-/- murine model showed a significant delay in the PanIN lesion formation with a significant reduction (p < 0.01) in EGFR (Y1068) and ERK1/2 (T202/Y204) phosphorylation. Further, a significant decrease (p < 0.01) in Sox9 expression in PanIN lesions of KPCM4-/- mice suggested the impairment of acinar-to-ductal metaplasia in Muc4-depleted cells. The biochemical analyses demonstrated that MUC4, through its juxtamembrane EGF-like domains, interacts with the EGFR ectodomain, and its cytoplasmic tail prevents EGFR ubiquitination and subsequent proteasomal degradation upon ligand stimulation, leading to sustained downstream oncogenic signaling. Targeting the MUC4 and EGFR interacting interface provides a promising strategy to improve the efficacy of EGFR-targeted therapies in PDAC and other MUC4-expressing malignancies.

Pancreatic Organoids: A Frontier Method for Investigating Pancreatic-Related Diseases

The pancreas represents an important organ that has not been comprehensively studied in many fields. To fill this gap, many models have been generated, and traditional models have shown good performance in addressing pancreatic-related diseases, but are increasingly struggling to keep up with the need for further research due to ethical issues, genetic heterogeneity and difficult clinical translation. The new era calls for new and more reliable research models. Therefore, organoids have been proposed as a novel model for the evaluation of pancreatic-related diseases such as pancreatic malignancy, diabetes, and pancreatic cystic fibrosis. Compared with common traditional models, including 2D cell culture and gene editing mice, organoids derived from living humans or mice cause minimal harm to the donor, raise fewer ethical concerns, and reasonably address the claims of heterogeneity, which allows for the further development of pathogenesis studies and clinical trial analysis. In this review, we analyse studies on the use of pancreatic organoids in research on pancreatic-related diseases, discuss the advantages and disadvantages, and hypothesize future trends.

GLI1 interaction with p300 modulates SDF1 expression in cancer-associated fibroblasts to promote pancreatic cancer cells migration

Carcinoma-associated fibroblasts (CAFs) play an important role in the progression of multiple malignancies. Secretion of cytokines and growth factors underlies the pro-tumoral effect of CAFs. Although this paracrine function has been extensively documented, the molecular mechanisms controlling the expression of these factors remain elusive. In this study, we provide evidence of a novel CAF transcriptional axis regulating the expression of SDF1, a major driver of cancer cell migration, involving the transcription factor GLI1 and histone acetyltransferase p300. We demonstrate that conditioned media from CAFs overexpressing GLI1 induce the migration of pancreatic cancer cells, and this effect is impaired by an SDF1-neutralizing antibody. Using a combination of co-immunoprecipitation, proximity ligation assay and chromatin immunoprecipitation assay, we further demonstrate that GLI1 and p300 physically interact in CAFs to co-occupy and drive SDF1 promoter activity. Mapping experiments highlight the requirement of GLI1 N-terminal for the interaction with p300. Importantly, knockdowns of both GLI1 and p300 reduce SDF1 expression. Further analysis shows that knockdown of GLI1 decreases SDF1 promoter activity, p300 recruitment, and levels of its associated histone marks (H4ac, H3K27ac, and H3K14ac). Finally, we show that the integrity of two GLI binding sites in the SDF1 promoter is required for p300 recruitment. Our findings define a new role for the p300-GLI1 complex in the regulation of SDF1, providing new mechanistic insight into the molecular events controlling pancreatic cancer cells migration.

Immunosuppression, immune escape, and immunotherapy in pancreatic cancer: focused on the tumor microenvironment

Pancreatic ductal adenocarcinoma (PDAC), the most common type of pancreatic cancer, is characterized by poor treatment response and low survival time. The current clinical treatment for advanced PDAC is still not effective. In recent years, the research and application of immunotherapy have developed rapidly and achieved substantial results in many malignant tumors. However, the translational application in PDAC is still far from satisfactory and needs to be developed urgently. To carry out the study of immunotherapy, it is necessary to fully decipher the immune characteristics of PDAC. This review summarizes the recent progress of the tumor microenvironment (TME) of PDAC and highlights its link with immunotherapy. We describe the molecular cues and corresponding intervention methods, collate several promising targets and progress worthy of further study, and put forward the importance of integrated immunotherapy to provide ideas for future research of TME and immunotherapy of PDAC.