Pancreatic ductal adenocarcinoma (PDAC) remains one of the most deadly malignancies with a highly immunosuppressive tumor immune microenvironment (TIME) that hinders effective therapy. PDAC is characterized by significant heterogeneity in immune cell composition, spatial distribution and activation states, which impacts tumor progression and treatment response. Tumour-infiltrating lymphocytes (TILs), including CD4+ T-helper cells, CD8+ cytotoxic T-cells and FOXP3+ regulatory T-cells, play a key role in immune regulation, yet PDAC is largely an immunologically "cold" tumour with limited effector T-cell infiltration. The surrounding cellular microenvironment, particularly Cancer Associated Fibroblasts (CAFs) and macrophages, contributes to immune evasion by promoting a fibrotic and desmoplastic barrier that limits TIL infiltration. The prognostic significance of TILs is increasingly recognized, with higher densities correlating with improved survival, whereas regulatory T-cell infiltration and immunosuppressive stromal interactions are associated with poor outcomes. Emerging therapeutic strategies targeting the TIME (e.g., CAFs), immune checkpoint inhibitors, and TIL-based therapies offer the potential to overcome resistance. Future research must focus on optimizing immunotherapy strategies and unravelling the complex stromal-immune interactions to improve clinical translation.

Pancreatic ductal adenocarcinoma (PDAC) is highly aggressive, with limited success in traditional therapies due to the fibrotic, immunosuppressive, pro-metastatic tumor microenvironment (TME), which collectively impede the drug accumulation and accelerate the tumor progression. In this work, we developed a PDAC-customized nutrient-mimicking reconstituted high-density lipoprotein (rHDL) capable of efficiently co-encapsulate versatile TME regulating cannabidiol and cytotoxic gemcitabine to simultaneously reprogram TME while suppressing PDAC progression. Specifically, a small-sized, nutrient-like rHDL was constructed to realize deep PDAC parenchyma penetration and efficient intra-tumoral uptake. Next, natural herbal compound cannabidiol was screened and incorporated into rHDL to regulate TME via attenuating fibrosis, reliving immunosuppression and mitigating metastatic tendency. At last, gemcitabine, the PDAC gold standard first-line therapy was co-delivered by the PDAC-customized rHDL to overcome drug resistance and amplify its PDAC suppression. Our findings demonstrate the feasibility of an integrated multi-stage TME regulation strategy for improved PDAC therapy, and might represent a modality in promoting chemotherapy against PDAC.

Pancreatic cancer characterized with intense hydraulic tissue in tumor extracellular matrix (ECM) resists most of chemotherapeutic drugs. Increased levels of hyaluronic acid (HA) represent the primary component of the hydraulic tissue, rendering tumors protective from drug targeting. Quercetin (Que), a natural flavonoid, has the ability to inhibit tumor cell growth in a number of cancers; however, its poor water solubility and low bioavailability largely limit its application in cancer therapy. Hence, we developed an efficient drug delivery system by encapsulation of Que. into liposomes and conjugation with hyaluronidase (HAase) at liposome surface, termed as HQL. In the presence of HAase, HQL were predominantly accumulated at tumor with enhanced permeability and retention effect. Treatment of xenografted tumor mice with HQL gave rise to suppressed tumor growth, while no toxic effects were observed in mice. HQL demonstrated the strong ability to inhibit cell proliferation, promote cell apoptosis, and induce arrest at G2/M cell cycle in pancreatic cancer lines, three-dimensional cultured cell spheroids and pancreatic ductal adenocarcinoma (PDAC)-derived organoids. Mechanistically, HQL downregulated expression of cell cycle-associated protein (CCNB1, CDK1 and PLK1) and cell apoptosis-associated factors PI3K/AKT and Bcl-2. In summary, HQL degraded HA in the tumor microenvironment to enhance nano-particle penetration and inhibited tumor cell growth, eliciting efficacy of anti-tumor therapy. Thereof, HQL may provide a novel efficient drug delivery approach for the adjuvant treatment of pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignant tumor characterized by a poor prognosis. A prominent feature of PDAC is the rich and dense stroma present in the tumor microenvironment (TME), which significantly hinders drug penetration. Cancer-associated fibroblasts (CAFs), activated fibroblasts originating from various cell sources, including pancreatic stellate cells (PSCs) and mesenchymal stem cells (MSCs), play a critical role in PDAC progression and TME formation. MicroRNAs (miRNAs) are small, single-stranded non-coding RNA molecules that are frequently involved in tumorigenesis and progression, exhibiting either oncolytic or oncogenic activity. Increasing evidence suggests that aberrant expression of miRNAs can mediate interactions between cancer cells and CAFs, thereby providing novel therapeutic targets for PDAC treatment. In this review, we will focus on the potential roles of miRNAs that target CAFs or CAFs-derived exosomes in PDAC progression, highlighting the feasibility of therapeutic strategies aimed at restoring aberrantly expressed miRNAs associated with CAFs, offering new pathways for the clinical management of PDAC.

Research studies aimed at improving the outcomes of patients with pancreatic ductal adenocarcinoma (PDAC) have brought about limited progress, and in clinical practice, the optimized use of surgery, chemotherapy and supportive care have led to modest improvements in survival that have probably reached a plateau. As a result, PDAC is expected to be the second leading cause of cancer-related death in Western societies within a decade. The development of therapeutic advances in PDAC has been challenging owing to a lack of actionable molecular targets, a typically immunosuppressive microenvironment, and a disease course characterized by rapid progression and clinical deterioration. Yet, the progress in our understanding of PDAC and identification of novel therapeutic opportunities over the past few years is leading to a strong sense of optimism in the field. In this Perspective, we address the aforementioned challenges, including biological aspects of PDAC that make this malignancy particularly difficult to treat. We explore specific areas with potential for therapeutic advances, including targeting mutant KRAS, novel strategies to harness the antitumour immune response and approaches to early detection, and propose mechanisms to improve clinical trial design and to overcome various community and institutional barriers to progress.

Pancreatic adenocarcinoma (PAAD) was characterized by dense fibrotic stroma and immunosuppressive tumor microenvironment (TME). TGFβ signaling pathways are highly activated in human cancers. However, the role of TGFβ2 in TME of PAAD remains to be elucidated. In this study, we showed that TGFβ2 was expressed at a relatively high level in PAAD tissues or cancer cells. Moreover, its high expression predicted unfavorable prognosis. In PAAD, gene set enrichment analysis showed that TGFβ2 correlated positively with leukocyte transendothelial migration, but negatively with aerobic metabolism, including oxidative phosphorylation. Results in Tumor and Immune System Interaction Database showed that TGFβ2 correlated with the infiltration of tumor-associated macrophages (TAMs), which could be attributed to that TGFβ2 promote CCL2 expression in PAAD. Moreover, correlation analysis showed that TGFβ2 could trigger cancer-associated fibroblasts (CAFs) activation in PAAD. The drug sensitivity analysis may indicate that patients with TGFβ2 high expression have higher sensitivity to chemotherapeutics, but the sensitivity to targeted drugs is still controversial. TGFβ2 could promote expansion of CAFs and infiltration of TAMs, thus participating in the construction of a fibrotic and immunosuppressive TME in PAAD. Targeting TGFβ2 could be a promising therapeutic approach, which needs to be elucidated by clinical and experimental evidences.

Pancreatic ductal adenocarcinoma (PDAC) has a complex tumor microenvironment enriched with tumor-associated macrophages. Triggering receptor expressed on myeloid cells 2 (TREM2) is highly expressed by a subset of macrophages in PDAC. However, the functional role of TREM2 in PDAC progression remains elusive.

We generated a novel transgenic mouse model (KPPC;Trem2-/-) that enables the genetic depletion of TREM2 in the context of spontaneous PDAC development. Single-cell RNA-sequencing analysis was used to identify changes in the tumor immune microenvironment on TREM2 depletion. We evaluated the impacts of TREM2 depletion on the tumor immune microenvironment to elucidate the functions of TREM2 in macrophages and PDAC development.

Unexpectedly, genetic depletion of TREM2 significantly accelerated spontaneous PDAC progression and shortened the survival of KPPC;Trem2-/- mice. Single-cell analysis revealed that TREM2 depletion enhanced proinflammatory macrophages and exacerbated pathogenic inflammation in PDAC. Specifically, TREM2 functions as a key braking mechanism for the NLRP3/nuclear factor-κB/interleukin (IL)-1β inflammasome pathway, opposing to microbial lipopolysaccharide as the key activator of this pathway. TREM2 deficiency orchestrated with microbial lipopolysaccharide to trigger IL-1β upregulation and pathogenic inflammation, thereby fueling PDAC development. Notably, IL-1β inhibition or microbiome ablation not only reversed the accelerated PDAC progression caused by TREM2 depletion, but also further inhibited PDAC progression in the TREM2-depleted context.

TREM2 depletion accelerates tumor progression by enhancing proinflammatory macrophages and IL-1β-mediated pathogenic inflammation in PDAC. The accelerated tumor progression by TREM2 depletion can be reversed by blocking IL-1β-associated pathogenic inflammation.

Pancreatic ductal adenocarcinoma (PDAC) is a cancer that is highly aggressive and has a challenging tumor microenvironment, which restricts the efficacy of conventional medical treatments. This investigation aims to formulate a localized anticancer hydrogel that incorporates a Paclitaxel/β-cyclodextrin (β-CD) nanocomplex composed of polyvinyl alcohol (PVA). Enhancements in drug delivery, therapeutic efficacy, adverse effects, and the mitigation of multidrug resistance are the objectives of PDAC treatment. In silico analyses were performed to examine the interaction between paclitaxel (PTX) and β-CD, which revealed favorable binding and pH-dependent release characteristics. Via FTIR and XRD analyses, the PTX/β-CD inclusion complex was verified. A hydrogel based on PVA was subsequently formed by incorporating this complex. The hydrogel's physicochemical and structural characteristics were examined using SEM, FTIR, XRD, and rheological methods.. Hydrogel's physical characteristics were evaluated through biodegradation and water absorption experiments. The cytotoxic and anti-metastatic potential of the hydrogel nanocomposite was quantified by conducting MTT assays and invasion and migration assays to assess its anticancer efficacy. The estimated adsorption energy (Eads) of PTX within β-CD to form the PTX/β-CD complex was -1.133 × 10-3 kJ/mol. In the Monte Carlo (MC) method, van der Waals forces and electrostatic interactions were considered based on group-based interactions with a cutoff radius of 12.5 Å. The interaction energy of B and PVA on PTX/β-CD was -319.150 kJ/mol. The binding energy (Ebinding = Einteraction) for B/PVA/PTX/β-CD was found to be -60.977 at pH 3.4 and -69.312 at pH 7.4. In acidic conditions, the Paclitaxel/β-CD nanocomplex exhibited efficient drug release and strong binding interactions. Biodegradation (80 % weight loss within 28 days) and water absorption (up to 500 % of its dried weight) were both exceptional characteristics of the PVA hydrogel. According to anticancer assays, the nanocomposite exhibited substantial cytotoxic effects, which included the inhibition of cancer cell migration and invasion. Paclitaxel's solubility and biological activity were significantly improved by the injectable hydrogel, which confirmed its potential as a sophisticated local drug delivery system. CONCLUSIONS: For the localized treatment of PDAC, the PVA-based injectable hydrogel that has been developed, which includes a Paclitaxel/β-CD nanocomplex, is a promising approach. Its targeted delivery, enhanced solubility, and potent anticancer characteristics offer a valuable method for enhancing therapeutic outcomes while reducing systemic side effects and multidrug resistance.

To enhance immunotherapy efficacy in pancreatic cancer, it is crucial to characterize its immune landscape and identify key factors driving immune alterations. To achieve this, we quantitatively analyzed the immune microenvironment using multiplex immunohistochemistry, assessing the spatial relationships between immune and tumor cells to correlate with patient survival rates and oncological factors. Additionally, through Whole Exome Sequencing analysis based on public data, we explored genetic mutations that could drive these compositions. Finally, we validated T cell (Tc) migration mechanisms using patient-derived tumor organoids with induced KRAS mutation subtypes. Through this approach, we obtained the following meaningful results. First, immune cells in pancreatic cancer are denser in stromal regions than near tumor cells, with higher Tc distribution linked to increased patient survival rates. Second, the distance between tumor and Tc was within 100 μm, with higher Tc density found within 15-30 μm of the tumor cells. Third, while increasing CAF levels correspond to higher Tc density, higher ECM density tends to decrease Tc presence. Fourth, compared to KRAS G12D, KRAS G12V mutation increases various immune cells, notably Tc, which is closely linked to a dramatic rise in vascular cells. Finally, Tc migration was enhanced in tumor organoids with the G12V mutation, attributed to a reduction in the secretion of immunosuppressive cytokines. Our results indicate that KRAS mutation subtypes influence immune cell composition and function in the pancreatic cancer microenvironment, leading to varied immunotherapy responses. This underscores the need for personalized immune therapeutics and research models specific to KRAS mutations.

Patients with pancreatic ductal adenocarcinoma (PDAC) derive limited benefits from chemotherapy or immunotherapy, with a five-year survival rate still below 10 %. The key therapeutic challenge is the dense fibrosis barrier driven by activated cancer-associated fibroblasts (CAFs) and their secreted collagen, which impedes drug penetration and characterizes PDAC as an immune-desert tumor. To address this challenge, we developed in vivo chimeric antigen receptor macrophages (FAP-CAR-M) targeting fibroblast activation protein-α (FAP), the marker of activated CAFs, to enhance chemo and immunotherapy against PDAC by removing the fibrosis barrier using mannose-modified mRNA-LNP (MLNP). Our results demonstrate that mRNA-MLNP can efficiently reprogram M2 macrophages into FAP-CAR-M. With the FAP-CAR-M treatment, the activated CAF markers (FAP), collagen volume fraction (CVF), and the type I collagen (col1a1) secretion were decreased by 3-fold, 5-fold, and 4-fold in orthotopic PDAC, respectively. By removing the fibrosis barrier, FAP-CAR-M enhanced the penetration of gemcitabine (GEM) and immune cells, improved PDAC sensitivity to chemo and immunotherapy, and significantly prolonged survival. Therefore, in vivo FAP-CAR-M may represent a potential therapeutic approach to enhance chemo and immunotherapy against PDAC by removing the fibrosis barrier.

Owing to the heterogeneous nature of pancreatic cancer, clinical prediction models are not sufficient for prognostication. Radiomics is quantitative noninvasive assessment performed from imaging which by means of mathematical models can decode tumor phenotype and further predict disease and treatment outcomes. This pilot study aims to investigate the association of CT-based radiomic features with overall survival (OS) in pancreatic cancer patients treated with stereotactic body radiation therapy (SBRT).

This study was conducted in patients of borderline resectable and locally advanced pancreatic cancer at our institute from January 2021 to December 2022. Ten patients underwent neoadjuvant chemotherapy, followed by SBRT with doses ranging from 33 Gy to 42 Gy administered in 5-6 fractions. Subsequent treatment included additional chemotherapy and evaluation for potential surgery. Radiomic features were extracted from planning CT images, and statistical analysis was performed using R software.

Out of 10 patients receiving neoadjuvant chemotherapy followed by SBRT, three underwent surgery. The duration of median follow-up was 15 months, and the median OS was 25 months. A total of 851 radiomic features including 107 original images features and 93 × 8 wavelet-based features were extracted. Using Lasso Cox regression, four wavelet-based features were found to influence the overall survival.

The present study demonstrates that CT-based radiomic features can be a promising tool in predicting survival and in addition to clinical parameters can provide detailed prognostic information that can facilitate personalized patient care. However, clinical implications of this radiomic analysis need a larger number of patients to validate the results.

The extracellular matrix (ECM) protein Beta-Ig H3 (βigH3, also known as transforming growth factor β induced protein (TGFBI)) is related to poor prognosis in patients with pancreatic ductal adenocarcinoma (PDAC). Proteolytic cleavage of βigH3 has been shown to result in release of the N-terminal fragment covering amino acid 1 to 137, but whether the degradation of βigH3 is associated to prognosis has yet to be determined. In this study we developed an ELISA targeting a collagenase generated fragment of βigH3 (cβigH3) in human serum to use the fragment as a biomarker reflecting degradation of βigH3. We demonstrated that the assay was specific to the cleaved fragment (cβigH3) and confirmed the generation of cβigH3 from degradation of fibroblast generated matrices. Moreover, higher levels of cβigH3 were released upon degradation of matrices produced by TGF-β stimulated pancreatic fibroblast compared to matrices produced by pancreatic fibroblast without TGF-β stimulation, indicating an association of the biomarker with degradation of fibrotic matrix. To evaluate the clinical relevance, we first measured cβigH3 in a cohort of 220 patients with different types of cancer with detectable levels for all 11 cancer types. We then measured the cβigH3 biomarker in pre-treatment serum from a cohort of 469 patients with locally advanced or metastatic PDAC and found that high levels of cβigH3 were associated with longer overall survival independently of age, disease stage, performance status, carbohydrate antigen 19-9 (CA19-9), and the tumor fibrosis biomarker PRO-C3 as compared to patients with high levels of cβigH3 (HR 0.78, 95% CI: 0.0.61-0.98, p = 0.04). In conclusion, cβigH3 reflects proteolytic degradation of βigH3 and shows potential as an independent prognostic biomarker for patients with advanced PDAC.

Extracellular proteins like transforming growth factor-β (TGFβ) are crucial enforcers in the development of cancer stroma and the tumor immunosuppressive microenvironment. Lysosome-targeting chimera-mediated protein degradation appeared as a promising tool for extracellular signal interference but was limited by several lysosome-trafficking receptors and inadequate in vivo degradation efficiency. Here, we designed a multivalent aptamer assembly with a universal pattern to drag extracellular proteins (e.g., TGFβ1) for lysosome degradation with high tumor specificity. By accelerating cell recognition-internalization and lysosomal delivery, the assembly promoted TGFβ blockade and degradation in pancreatic cancer cells and pancreatic stellate cells (PSCs). In vivo, the assembly exhibited highly tumor-specific accumulation and prolonged retention, which resulted in efficient TGFβ inhibition, stromal remodeling, and reversed polarization of immunosuppressive cells in the tumor microenvironment, as well as synergic therapeutic effects when combined with gemcitabine or ovalbumin. Therefore, this study provides a feasible strategy to construct a multivalent aptamer assembly for tumor-specific extracellular protein degradation, after remodeling the tumor stromal and immunosuppressive microenvironment in a manner that enhances the effects of cancer chemotherapy and immunotherapy.

Chimeric antigen receptor (CAR) T cell therapy has revolutionized the treatment of haematological malignancies. Challenges in overcoming physical barriers however greatly limit CAR-T cell efficacy in solid tumours. Here we show that an approach based on collagenase nanogel generally improves the outcome of T cell-based therapies, and specifically of CAR-T cell therapy. The nanogels are created by cross-linking collagenase and subsequently modifying them with a CXCR4 antagonist peptide. These nanogels can bind CAR-T cells via receptor-ligand interaction, resulting in cellular backpack delivery systems. The nanogel backpacks modulate tumoural infiltration and localization of CAR-T cells by surmounting physical barriers and disrupting chemokine-mediated CAR-T cell imprisonment, thereby addressing their navigation deficiency within solid tumours. Our approach offers a promising strategy for pancreatic cancer therapy and holds potential for advancing CAR-T cell therapy towards clinical applications.

Developing T-cell or vaccine therapies for pancreatic ductal adenocarcinoma (PDAC) has been challenging because of a lack of knowledge regarding immunodominant, cancer-specific antigens as PDAC are characterized by a scarcity of genomic mutation-associated neoepitopes, and effective approaches to discover them are limited.

An advanced mass spectrometry approach was employed to compare the immunopeptidome of PDAC tissues and matched normal tissues from the same patients.

This study identified HLA class I-binding variant peptides derived from canonical proteins, which had single amino-acid substitutions not attributed to genetic mutations or RNA editing. These amino-acid substitutions appeared to result from translational errors. The variant peptides were predominantly found in tumor tissues, with certain peptides common among multiple patients. Importantly, several of these variant peptides were more immunogenic than their wild-type counterparts.

The shared noncanonical neoepitopes identified in this study offer promising candidates for vaccine and T-cell therapy development, potentially providing new avenues for immunotherapy in PDAC. See related commentary by Yuan et al., p. 1821.

The tumor microenvironment (TME) plays a crucial role in cancer development and spreading being considered as "the dark side of the tumor". Within this term tumor cells, immune components, supporting cells, extracellular matrix and a myriad of bioactive molecules that synergistically promote tumor development and therapeutic resistance, are included. Recent findings revealed the profound impacts of TME on cancer development, serving as physical support, critical mediator and biodynamic matrix in cancer evolution, immune modulation, and treatment outcomes. TME targeting strategies built on vasculature, immune checkpoints, and immuno-cell therapies, have paved the way for revolutionary clinical interventions. On this basis, the relevance of pre-clinical and clinical investigations has rapidly become fundamental for implementing novel therapeutical strategies breaking cell-cell and cell -mediators' interactions between TME components and tumor cells. This review summarizes the key players in the breast and pancreatic TME, elucidating the intricate interactions among cancer cells and their essential role for cancer progression and therapeutic resistance. Different tumors such breast and pancreatic cancer have both different and similar stroma features, that might affect therapeutic strategies. Therefore, this review aims to comprehensively evaluate recent findings for refining breast and pancreatic cancer therapies and improve patient prognoses by exploiting the TME's complexity in the next future.

Pancreatic cancer, a highly lethal malignancy with limited therapeutic options, necessitates the identification of novel prognostic biomarkers and therapeutic targets. The extracellular matrix protein vitronectin (VTN) has been implicated in tumor progression, but its specific role in pancreatic cancer progression and immunotherapy response remains unclear.

This study employed an integrative approach combining single-cell RNA sequencing, analysis of public databases, and functional assays. In vitro experiments assessed the impact of VTN knockdown and overexpression on pancreatic cancer cell proliferation, invasion, and migration. Mechanistic investigations explored associations between VTN expression and immune regulatory factors. A syngeneic mouse subcutaneous tumor model evaluated the therapeutic efficacy of VTN overexpression combined with anti-PD1 immunotherapy.

VTN was significantly downregulated in pancreatic cancer tissues compared to normal tissues. Lower VTN levels correlated with poorer overall survival. VTN knockdown promoted pancreatic cancer cell proliferation, invasion, and migration in vitro, whereas VTN overexpression suppressed these phenotypes. VTN expression was linked to immune regulatory pathways. High VTN levels predicted improved survival in patients receiving anti-PD1/PD-L1 therapy. In a mouse model, VTN overexpression inhibited tumor growth and synergized with anti-PD1 therapy to enhance antitumor efficacy, suggesting combinatorial therapeutic potential.

This study identifies VTN as a dual-functional regulator in pancreatic cancer, acting as both a suppressor of tumor progression and a modulator of immunotherapy response. These findings position VTN as a prognostic biomarker and a therapeutic target to sensitize pancreatic tumors to anti-PD1-based immunotherapy, providing a potential strategy for overcoming treatment resistance in this aggressive malignancy.

Integrating an oncotic immunogenic cell death (ICD) inducer with TLR agonists to facilitate chemo-immunotherapy presents a promising avenue for addressing cancer treatment. While each agent shown remarkable potential in eliciting immune responses individually, the synergistic capabilities of oncotic chemotherapeutics in combination with TLR agonists remain an uncharted area of research. Herein, to prevent the occurrence of off-target systemic inflammatory side effects associated with the TLR7/8 agonist, the reactive amino group of Resiquimod (R848) was covalently linked to human serum albumin (HSA) via a glutathione (GSH)-activatable linker, thereby establishing a series of R848-HSA conjugates. Specifically, RS-HSA (with an R848: HSA ratio of 1.6:1, n/n) was assembled with an oncotic membrane-active peptide (iPep) to form iP-RS NPs, which exhibited reduced toxicity and synergistic effects in modulating the tumor immunosuppressive microenvironment, disrupting the surrounding desmoplastic stroma, and enhancing anti-tumor immunity. The iP-RS NPs demonstrated satisfactory chemo-immune effects, achieving complete tumor regression in orthotopic 4T1 breast tumor mice and subcutaneous Panc02 pancreatic tumor mice. Furthermore, iP-RS NPs achieved successful treatment in three out of five mice harboring a clinically relevant and challenging orthotopic model of fLuc-KPC pancreatic ductal adenocarcinoma (PDAC), leading to a significant prolongation of their survival. In stark contrast, the first-line treatment regimen of Gemcitabine + Nab-paclitaxel offered only a marginal survival extension of less than a week when compared to the PBS control group. Our findings underscore the promising prospects of combining oncotic therapeutics with TLR7/8 agonists, with a rational design aimed at minimizing the toxicity of the TLR agonist while achieving superior synergistic therapeutic efficacy.

Pancreatic cancer has a complex immunosuppressive tumor microenvironment (TME), which is highly resistant to conventional therapies and emerging cancer immunotherapies. Oncolytic viruses are multifaceted killers of malignant tumors, which can selectively infect, replicate in and lyse tumor cells, release tumor-associated antigens to stimulate specific antitumor immune responses, and recruit immune cells into the TME, turning "cold" tumors "hot". Here, we report a novel vaccinia virus (VV), VVLΔTKΔN1LΔA41L (with deletion of thymidine kinase (TK), N1L, and A41L genes) armed with interleukin 27 (IL-27), that can cure established tumors and promote long-term antitumor immunity in murine pancreatic cancer tumor models.

A novel oncolytic VV with deletion of the TK, N1L, and A41L genes, and expression of the red fluorescent protein (RFP) gene (VVL-TD-RFP) was constructed using CRISPR-Cas9-based homologous recombination. This virus was armed with IL-27, creating VVL-TD-IL-27. The characteristics of these viruses were evaluated in vitro using viral replication assays, cytotoxicity assays and ELISA. The antitumor effects of VVL-TD-IL-27 were evaluated using a variety of pancreatic cancer tumor models in vivo, and the mechanisms of antitumor effects were explored using flow cytometry, immunohistochemistry, ELISA and quantitative PCR.

VVL-TD-RFP cured 71.4% of tumor-bearing mice, compared with 14.3% of animals treated with VVLΔTKΔN1L that does not have an A41L gene deletion. Efficacy was mainly dependent on elevated dendritic cell (DC) populations, activation of DC, CD86+ DC, and CD8+ effector memory T cells in the TME. Efficacy was further enhanced by arming VVL-TD-RFP with IL-27, which resulted in a cure rate of 100% and promoted long-term antitumor immunity. VVL-TD-IL-27 treatment increased the proportion of CD8+ TEM and decreased the proportion of regulatory T cells and macrophages in tumor tissues. It also polarized macrophages to an M1 phenotype in vivo. Furthermore, IL-27 exhibits strong anti-angiogenic effects.

VVL-TD-mIL-27 is a potential immunotherapy agent for the treatment of pancreatic cancer, and a clinical study of this virus is warranted.

The tumor microenvironment (TME) is a unique ecosystem that surrounds tumor tissues. The TME is composed of extracellular matrix, immune cells, blood vessels, stromal cells, and fibroblasts. These environments enhance cancer development, progression, and metastasis. Recent success in immune checkpoint blockade also supports the importance of the TME and immune cells residing in the tumor niche. Although the TME can be identified in almost all cancer types, the role of the TME may not be similar among different cancer types. Regulatory T cells (Tregs) play a pivotal role in immune homeostasis and are frequently found in the TME. Owing to their suppressive function, Tregs are often considered unfavorable factors that allow the immune escape of cancer cells. However, the presence of Tregs is not always linked to an unfavorable phenotype, which can be explained by the heterogeneity and plasticity of Tregs. In this review, the current understanding of the role of Tregs in TME is addressed for each cancer cell type. Moreover, recently a therapeutic approach targeting Tregs infiltrating in the TME has been developed including drug antibody conjugate, immunotoxin, and FOXP3 inhibiting peptide. Thus, understanding the role of Tregs in the TME may lead to the development of novel therapies that directly target the TME.

Myofibroblastic cancer-associated fibroblasts (CAF) in tumor stroma serves as an independent poor prognostic indicator, supporting higher stemness in oral cancer; however, the underlying biology is not fully comprehended. Here, we have explored the crucial role of Tunica Interna Endothelial Cell Kinase (Tie2/TEK) signaling in transition and maintenance of myofibroblastic phenotype of CAFs, and as possible link with the poor prognosis of head and neck squamous cell carcinoma (HNSCC) patients.

Bulk and single cell RNA-sequencing (scRNAseq) methods and in-depth bioinformatic analysis were applied for CAF and cancer cells co-culture for studying molecular relationships. In vitro 3D-spheroid-forming ability, expression of stemness markers, in vivo tumor formation ability in zebrafish embryo and syngeneic mouse allografts formation was conducted to test stemness, upon targeting CAF-specific Tie2 activity by gene silencing or with small molecule inhibitor. Immunohistochemistry analysis was performed to locate the distribution of Tie2 and αSMA in primary tumors of oral carcinoma. Prognosis in HNSCC patient cohort from The Cancer Genome Atlas (TCGA) study was analysed based on single sample gene set enrichment score (ssGSEA) and Kaplan-Meier analysis.

Autocrine or exogenous TGFβ-induction in CAF led to the recruitment of histone deacetylase 2 (HDAC2) on the promoter of Tie2-antagonist, Angiopoietin-2 (ANGPT2), resulting in its downregulation, leading to phosphorylation of Tie2 (Y992) and subsequent activation of SRC (Y418). This led to SRC/ROCK mediated αSMA-positive stress-fiber formation with gain of myofibroblast phenotype. The CAF-specific Tie2-signaling was responsible for producing embryonic-like cell state in co-cultured cancer cells; with enhanced tumor initiating ability. Tie2 activity in CAF exerted the dynamic gene expression reprogramming, with the upregulation of 'cell migration' and downregulation of 'protein biosynthesis' related gene-regulatory-network modules in malignant cells. The AUCell scores calculated for gene signatures derived from these modules showed significant concordance in independently reported scRNAseq studies of HNSCC tumors and significant association with poor prognosis in HNSCC patient cohort.

CAF-specific Tie2 activity may serve as direct stromal-target against cancer cell plasticity leading to poor prognosis of oral cancer patients. Overall, our work has provided wider applicability of Tie2-specific functions in tumor biology, along with its known role in endothelial cell-specific function.

Sono-immunotherapy is expected to effectively enhance treatment efficacy and reduce mortality in patients with pancreatic cancer. Hence, efficient applicable sono-immunotherapy systems are urgently needed for the treatment of this condition. In this study, hollow mesoporous carbon (HMC) nanoparticles were prepared using the sacrificial template method. These nanoparticles had a porphyrin-like structure and could generate singlet oxygen more efficiently than commercial TiO2. Cellular assays showed that HMC killed tumor cells in the presence of ultrasonication, primarily by inducing apoptosis. HMC could also accelerate the release of immune factors by tumor cells, thereby activating dendritic cells and enhancing the efficacy of immunotherapy. Experiments in tumor-bearing mice and in situ pancreatic cancer tests showed that HMC, in combination with the small-molecule inhibitors of programmed cell death ligand 1, could reduce tumor growth via the generation of reactive oxygen species following ultrasonication. HMC could enhance the efficacy of immunotherapy by disrupting the immunosuppressive tumor microenvironment and promoting the accumulation of immune cells. Accordingly, in vivo sono-immunotherapy was achieved, and the growth of transplanted tumors and in situ tumors could be reduced. In conclusion, this study proposes a novel method for the preparation of HMC nanoparticles and demonstrates their potential in tumor treatment. Additionally, owing to their unique structure, these HMC nanoparticles could be used for different combination therapies tailored based on specific clinical requirements.

Pancreatic cancer (PC), with pancreatic ductal adenocarcinoma (PDAC) comprising about 90% of all cases, is one of the most aggressive and lethal solid tumors. PDAC remains one of the most significant challenges of oncology to this day due to its inadequate response to conventional treatment, gradual rise in incidence since 2004, and poor five-year survival rates. As cancer cells are the primary adversary in this uneven fight, they remain the primary research target. Nevertheless, increasing attention is being paid to the tumor microenvironment (TME). The most crucial TME constellation components are immune cells, especially macrophages, stellate cells and lymphocytes, fibroblasts, bacterial and fungal microflora, and neuronal cells. Depending on the particular phenotype of these cells, the composition of the microenvironment, and the cell ratio, patients can experience different disease outcomes and varying vulnerability to treatment approaches. This study aims to present the current knowledge and review the most up-to-date scientific findings regarding the microenvironment of PC. It contains detailed information on the structure and cellular composition of the stroma, including its impact on disease development, metastasis, and response to treatment, as well as the therapeutic opportunities that arise from targeting this tissue.

Spatial proteomics enables in-depth mapping of tissue architectures, mostly achieved by laser microdissection-mass spectrometry (LMD-MS) and antibody-based imaging. However, trade-offs among sampling precision, throughput, and proteome coverage still limit the applicability of these strategies. Here, we propose proximity labeling for spatial proteomics (PSPro) by combining precise antibody-targeted biotinylation and efficient affinity purification for all-at-once cell-type proteome capture with sub-micrometer resolution from single tissue slice. With fine-tuned labeling parameters, PSPro shows reliable performance in benchmarking against flow cytometry- and LMD-based proteomic workflows. We apply PSPro to tumor and spleen slices, enriching thousands of proteins containing known markers from ten cell types. We further incorporate LMD into PSPro to facilitate comparison of cell subpopulations from the same tissue slice, revealing spatial proteome heterogeneity of cancer cells and immune cells in pancreatic tumor. Collectively, PSPro converts the traditional "antibody-epitope" paradigm to an "antibody-cell-type proteome" for spatial biology in a user-friendly manner. A record of this paper's transparent peer review process is included in the supplemental information.

The stroma of healthy pancreases contains various non-hematopoietic, non-endothelial mesenchymal cells. It is altered by chronic inflammation which in turn is a major contributor to the development of pancreatic adenocarcinoma (PDAC). In PDAC, the stroma plays a decisive and well-investigated role for tumor progression and therapy response. This review addresses the central role of stromal cells in the early inflammation-driven development of PDAC. It focuses on major subpopulations of pancreatic mesenchymal cells, i.e., fibroblasts, pancreatic stellate cells, and multipotent stroma cells, particularly their activation and functional alterations upon chronic inflammation including the development of different types of carcinoma-associated fibroblasts. In the second part, the current knowledge on the impact of activated stroma cells on acinar-to-ductal metaplasia and the transition to pancreatic intraepithelial neoplasia is summarized. Finally, putative strategies to target stroma cells and their signaling in early pancreatic carcinogenesis are reflected. In summary, the current data show that the activation of pancreatic stroma cells and the resulting fibrotic changes has pro- and anti-carcinogenetic effects but, overall, creates a carcinogenesis-promoting microenvironment. However, this is a dynamic process and the therapeutic targeting of specific pathways and cells requires in-depth knowledge of the molecular interplay of various cell types.

Alternative cleavage and polyadenylation (APA) have gained increasing attention in cancer biology, yet its role in modulating anti-tumor immune response remains largely unexplored. Here, we identify the cleavage stimulation factor 2 (CSTF2), an APA-related gene, as a pivotal suppressor of anti-tumor immunity in pancreatic ductal adenocarcinoma (PDAC). CSTF2 promotes tumor development by inhibiting the infiltration and cytotoxic immune cell recruitment function of TCRαβ+CD4-CD8-NK1.1- innate αβ T (iαβT) cells. Mechanistically, CSTF2 diminishes CXCL10 expression by promoting PolyA polymerase alpha (PAPα) binding to the 3' untranslated regions of CXCL10 RNA, resulting in shortened PolyA tails and compromised RNA stability. Furthermore, we identify Forsythoside B, a selective inhibitor targeting the RNA recognition motif of CSTF2, can effectively activate anti-tumor immunity and overcome resistance to immune checkpoint blockade (ICB) therapy. Collectively, our findings unveil CSTF2 as a promising therapeutic target for sensitizing PDAC to ICB therapy.

Cancer biomarker discovery is essential for early detection and monitoring, yet there is a lack of comprehensive studies examining organ-specific biomarkers across various cancer types. In this study, we analyzed clinical data from 59,184 cancer patients diagnosed between 2013 and 2023, focusing on 11 major cancer systems. We used propensity score matching with 55,010 healthy controls to create balanced comparison groups. Serum biomarker profiles were assessed through principal component analysis, differential expression analysis, and ROC curve analysis. Our findings revealed organ-specific biomarker patterns, such as decreased CA724, ferritin, and β2-microglobulin in thoracic cancer, reduced serum phosphorus in neurological cancer, and elevated cystatin C and creatinine in urinary system cancer. Further analysis across 22 cancer types uncovered additional biomarkers, including elevated ALT in hepatobiliary cancer, altered coagulation factors in laryngeal cancer, increased monocytes in pancreatic cancer, and reduced complement C3 in intestinal cancer. These results provide valuable insights into the unique biomarker signatures for different cancers, contributing to the potential development of more targeted and efficient screening methods.

Pancreatic ductal adenocarcinoma (PDAC) is the most common and lethal form of pancreatic cancer. One major cause for a fast disease progression is the presence of a highly fibrotic tumor microenvironment (TME) mainly composed of cancer-associated fibroblasts (CAF), and various immune cells, especially tumor-associated macrophages (TAM). To conclusively evaluate drug efficacy, it is crucial to develop in vitro models that can recapitulate the cross talk between tumor cells and the surrounding stroma. Here, we constructed a fit-for-purpose biochip platform which allows the integration of PDAC spheroids (composed of PANC-1 cells and pancreatic stellate cells (PSC)). Additionally, the chip design enables dynamic administration of drugs or immune cells via a layer of human umbilical vein endothelial cells (HUVEC). As a proof-of-concept for drug administration, vorinostat, an FDA-approved histone deacetylase inhibitor for cutaneous T cell lymphoma (CTCL), subjected via continuous flow for 72 h, resulted in a significantly reduced viability of PDAC spheroids without affecting vascular integrity. Furthermore, dynamic perfusion with peripheral mononuclear blood cells (PBMC)-derived monocytes resulted in an immune cell migration through the endothelium into the spheroids. After 72 h of infiltration, monocytes differentiated into macrophages which polarized into the M2 phenotype. The polarization into M2 macrophages persisted for at least 168 h, verified by expression of the M2 marker CD163 which increased from 72 h to 168 h, while the M1 markers CD86 and HLA-DR were significantly downregulated. Overall, the described spheroid-on-chip model allows the evaluation of novel therapeutic strategies by mimicking and targeting the complex TME of PDAC.

Pancreatic ductal adenocarcinoma (PDAC) is characterized by a dense, immunosuppressive tumor microenvironment (TME) that limits therapeutic efficacy. This study investigates the role of cellular communication network factor 1 (CCN1, also known as Cyr61), an extracellular matrix-associated protein, in modulating the TME of PDAC. It is demonstrated that Ccn1 promotes PDAC progression by upregulating collagen and chemokine expression, thereby facilitating immune cell exclusion and enhancing tumor growth. Using a Ccn1-deficient PDAC model, decreased collagen and chemokine levels are observed, resulting in increased infiltration of cytotoxic immune cells and reduced myeloid-derived suppressor cells (MDSCs). Furthermore, Ccn1-deficient tumors exhibit heightened sensitivity to gemcitabine and show enhanced responsiveness to anti-programmed cell death 1 (anti-PD1) therapy. Mechanistically, Ccn1 regulates chemokine production through collagen expression, with chemokine levels remaining suppressed even upon interferon-gamma treatment in collagen-deficient cells. These findings highlight Ccn1 as a potential therapeutic target that reprograms the TME to enhance the efficacy of both chemotherapy and immunotherapy in PDAC, providing a novel approach for overcoming immune resistance in PDAC.

In cancer therapy, enhancing therapeutic indices and patient compliance has been a central focus in recent drug delivery technology development. However, achieving a delicate balance between improving anti-tumor efficacy and minimizing toxicity to normal tissues remains a significant challenge. With the advent of smart on-demand drug release strategies, new opportunities have emerged. These strategies represent a promising approach to drug delivery, enabling precise control over the release of therapeutic agents in a programmed and spatiotemporal manner. Recent studies have focused on designing delivery systems capable of releasing multiple therapeutic agents sequentially, while achieving spatial resolution in vivo. Smart on-demand drug release strategies have demonstrated considerable potential in tumor combination therapy for achieving precision drug delivery and controlled release by responding to specific physiological signals or external physical stimuli in the tumor microenvironment. These strategies not only improve tumor targeting and reduce toxicity to healthy tissues but also enable sequential release in combination therapy, allowing multiple drugs to be released in a specific spatiotemporal order to enhance synergistic treatment effects. In this paper, we systematically reviewed the current research progress of smart on-demand drug release drug delivery strategies in anti-tumor combination therapy. We highlighted representative integrated drug delivery systems and discussed the challenges associated with their clinical application. Additionally, potential future research directions are proposed to further advance this promising field.

Despite constitutive Ras/Raf/MAPK pathway activation in most pancreatic ductal adenocarcinomas (PDACs), treatment approaches targeting this pathway have primarily been unsuccessful. We conduct a drug library screen on an MEK inhibitor (MEKi)-resistant PDAC model and perform complementary pathway analysis to identify cellular resistance phenotypes. We use syngeneic models to investigate the molecular determinants of identified drug synergism. Our study reveals an enrichment for the hallmarks of G2/M checkpoints in MEKi-resistant phenotypes from all investigated models. We find overexpression of Polo-like kinase 1 (PLK1) and other G2/M checkpoint-related proteins in MEKi-resistant cells. We identify synergistic activity between MEK and PLK1 inhibition both in vitro and in vivo and mechanistically show that dual inhibition of the PLK1 and MEK pathways activates the JNK/c-JUN pathway. This causes the accumulation of DNA damage, ultimately leading to apoptotic cell death. Dual PLK1/MEK inhibition emerges as a promising targeted approach in PDAC.

Immune-based treatment strategies have emerged across solid organ malignancies largely with the development of immune checkpoint inhibitors. To date, these strategies have not improved clinical outcomes in pancreatic ductal adenocarcinoma (PDAC).

Here, we perform a systematic review to summarize available evidence for recent immune-based treatment strategies in PDAC. We analyze trends in activated clinical trials queried from clinicaltrials.gov in the years 2020-2022. We review study design, sponsorship, and trends in the phase of development. There is a growing emergence of multiple new classes of immune-based targets and combination strategies in early-phase development.

Immune-based clinical trials in PDAC are highly collaborative including primarily stakeholders in government, industry, and academic medical centers. In this period, a majority of trials have integrated a non-randomized design (83.2%), including a trend towards an increase in Phase I/II clinical trials. This analysis found a growing list of studies using combinations including inhibitors of vascular endothelial growth factors (VEGF), an expanded set of vaccine-based strategies, and the use of Bispecific T-Cell Engagers (BiTEs). Immune checkpoint inhibitors have been a mainstay of combination strategies including the use of new immune checkpoint inhibitors (CD40, TIGIT).

Immune-based strategies in PDAC have expanded across new targets and the complexities of combinatory approaches. Integrating this work across key stakeholders remains of critical importance to improve clinical outcomes.

The tumor microenvironment (TME) plays a critical role in the poor clinical outlook for pancreatic ductal adenocarcinoma (PDAC). Activated pancreatic stellate cells (PSC) drive the complex interactions within the TME, resulting in a microenvironment that is resistant to chemotherapy and tolerant to the immune system, thereby promoting tumor growth. Effective deactivation of PSC is vital in treating pancreatic cancer. However, previous studies have only focused on limited changes in PSC phenotype without comprehensively analysing their overall function. Our transcriptome analysis identified agents capable of modulating multiple biological functions of PSC, including fibrosis, extracellular matrix generation, and the secretion of cytokines and immune factors. Through this comprehensive assessment, we discovered that flumethasone (Flu) effectively deactivates PSC. This glucocorticoid analogue remodels the tumor microenvironment by regulating the secretomes of PSC and their interaction with tumor cells. Additionally, our research revealed that activated PSC exhibited heightened albumin endocytosis. As a result, we propose that albumin conjugation could serve as an effective targeted drug delivery approach for PSC. Our findings also demonstrate that albumin-conjugated Flu maintained reprogramming capabilities in stromal cells, and enhanced the efficacy of chemotherapy in orthotopic mouse models of PDAC and KrasG12D/+; LSL-Trp53R172H/+; Pdx-1-Cre (KPC) pancreatic tumor allograft mouse model. Our investigation into the mechanism of PSC deactivation by flumethasone has revealed its potential for clinical cancer treatment through its effects on the tumor microenvironment. Furthermore, the conjugation of flumethasone to albumin enhances its safety and targeted delivery, offering a promising approach for PSC-targeted drug application in pancreatic cancer treatment.

The tumor microenvironment (TME) encompasses various cell types, blood and lymphatic vessels, and noncellular constituents like extracellular matrix (ECM) and cytokines. These intricate interactions between cellular and noncellular components contribute to the development of a malignant TME, such as immunosuppressive, desmoplastic, angiogenic conditions, and the formation of a niche for cancer stem cells, but there is limited understanding of the specific subtypes of stromal cells involved in this process. Here, we utilized p16-CreERT2-tdTomato mouse models to investigate the signaling networks established by senescent cancer stromal cells, contributing to the development of a malignant TME. In pancreatic ductal adenocarcinoma (PDAC) allograft models, these senescent cells were found to promote cancer fibrosis, enhance angiogenesis, and suppress cancer immune surveillance. Notably, the selective elimination of senescent cancer stromal cells improves the malignant TME, subsequently reducing tumor progression in PDAC. This highlights the antitumor efficacy of senolytic treatment alone and its synergistic effect when combined with conventional chemotherapy. Taken together, our findings suggest that the signaling crosstalk among senescent cancer stromal cells plays a key role in the progression of PDAC and may be a promising therapeutic target.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive cancers, primarily due to its complex tumor microenvironment (TME), which drives both disease progression and therapy resistance. Understanding the molecular mechanisms governing TME dynamics is essential for developing new treatment strategies for this devastating disease. In this study, we uncover an oncogenic role for Galectin-1 (Gal1), a glycan-binding protein abundantly expressed by activated pancreatic stellate cells (PSCs), a key component of the PDAC TME that orchestrates tumor progression. Our findings reveal that Gal1 expression is elevated in the nucleus of human PSCs in both tissue samples and cultured cell lines. Using chromatin immunoprecipitation followed by sequencing analysis (ChIP-seq), we identify Gal1 occupancy at the promoters of several cancer-associated genes, including KRAS, a pivotal oncogene involved in PDAC pathogenesis. We demonstrate that Gal1 binds to the KRAS promoter, sustaining KRAS expression in PSCs, which, in turn, maintains PSC activation and promotes the secretion of protumorigenic cytokines. Mechanistically, Gal1 is required to preserve histone H3 lysine 4 monomethylation levels and to recruit the histone methyltransferase MLL1 to target promoters. Collectively, our findings define a nuclear function of Gal1 in modulating the transcriptional landscape of cancer-associated genes in PSCs within the PDAC TME, mediated through an epigenetic mechanism. These insights enhance our understanding of PDAC pathology and open potential avenues for therapeutic interventions targeting intracellular Gal1.