Cancer-associated fibroblasts in pancreatic ductal adenocarcinoma

Isorhamnetin exerts anti-proliferative effect on cancer-associated fibroblasts by inducing cell cycle arrest

Isorhamnetin (ISO), a dietary flavonoid, has been shown to possess antioxidant, anti-cancer, and anti-inflammatory properties. Cancer-associated fibroblasts (CAFs), found in the tumor microenvironment of several types of cancer including pancreatic ductal adenocarcinoma (PDAC) impact the tumor growth and development of chemoresistance. Thus, modulating CAFs is an attractive mean to increase the efficacy of therapies targeting cancer cells. In this study, the anti-proliferative effect of ISO and the underlying transcriptomic profile of ISO-treated PDAC-derived CAFs were investigated. ISO treatment showed a time- and concentration-dependent decrease in cell viability with a slight increase in apoptotic cells. Microarray and cell cycle analyses revealed ISO induced downregulation of pathways in cell cycle and DNA replication; and G2/M checkpoint. Cell cycle analysis showed cells in the G2/M phase were increased. In response to the treatment, hallmark for p53 pathway genes, known to regulate cell cycle checkpoints, were highly upregulated. Moreover, ISO-treated cells had an increased area of the mitochondrial network, but lower mitochondrial membrane potential accompanied by a decrease of ATP production, measured by oxygen consumption rate. Inflammatory gene expression of IL1A1, IL6, CXCL1, and LIF were significantly inhibited in ISO-treated CAFs. Taken together, our results demonstrated that the cytostatic effect of ISO on human CAFs was mediated by inducing cell cycle arrest at G2/M phase associated with activation of p21, impaired mitochondrial homeostasis, and inhibition of inflammatory mediators gene expression, warranting further investigation for its use in combinatorial therapy that target both the cancer and the tumor microenvironment as a whole.

Ribosome biogenesis, altered metabolism and ribotoxic stress response in pancreatic ductal adenocarcinoma tumor microenvironment

Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy with a poor overall survival rate. Cellular stress response pathways promoting cancer cell fitness in harsh tumor microenvironment (TME) play a critical role in cancer growth and survival. The influence of oncogenic Kras, multi-functional heterogeneous cancer-associated fibroblasts (CAFs), and immunosuppressive TME on cancer cells makes the disease more complex and difficult to treat. The desmoplastic reaction by CAFs comprises approximately 90 % of the tumor, with only 10 % of cancer cells making things even more complicated, resulting in therapy resistance. Consistently increasing fibrosis creates a hypoxic environment and elevated interstitial fluid pressure inside the tumor constraining vascular supply. Stress conditions in TME alter translation efficiency and metabolism to fulfill the energy requirements of rapidly growing cancer cells. Extensive research has been conducted on multiple molecular and metabolic regulators in PDAC TME. However, the role of TME in influencing translation programs, a prerequisite for cell cycle progression and functional/growth requirements for cancer cells, remains elusive. This review highlights the recent advancements in understanding altered translational programs in PDAC TME. We emphasize the role of ribosome biogenesis, ribosome-induced stress response, and the concept of specialized ribosomes and their probable role in mutationally rewiring the pancreatic TME.

The use of a multi-metric readout screen to identify EHMT2/G9a-inhibition as a modulator of cancer-associated fibroblast activation state

Cancer-associated fibroblasts (CAFs) play a pivotal role in cancer progression, including mediating tumour cell invasion via their pro-invasive secretory profile and ability to remodel the extracellular matrix (ECM). Given that reduced CAF abundance in tumours correlates with improved outcomes in various cancers, we set out to identify epigenetic targets involved in CAF activation in regions of tumour-stromal mixing with the goal of reducing tumour aggressiveness. Using the GLAnCE (Gels for Live Analysis of Compartmentalized Environments) platform, we performed an image-based, phenotypic screen that enabled us to identify modulators of CAF abundance and the capacity of CAFs to induce tumour cell invasion. We identified EHMT2 (also known as G9a), an enzyme that targets the methylation of histone 3 lysine 9 (H3K9), as a potent modulator of CAF abundance and CAF-mediated tumour cell invasion. Transcriptomic and functional analysis of EHMT2-inhibited CAFs revealed EHMT2 participated in driving CAFs towards a pro-invasive phenotype and mediated CAF hyperproliferation, a feature typically associated with activated fibroblasts in tumours. Our study suggests that EHMT2 regulates CAF state within the tumour microenvironment by impacting CAF activation, as well as by magnifying the pro-invasive effects of these activated CAFs on tumour cell invasion through promoting CAF hyperproliferation.

The multi-faceted roles of cancer-associated fibroblasts in pancreatic cancer

The tumor microenvironment (TME) has been linked with the pathogenesis of pancreatic ductal adenocarcinoma (PDAC), the most common histological subtype of pancreatic cancer. A central component of the TME are cancer-associated fibroblasts (CAFs), which can either suppress or promote tumor growth in a context-dependent manner. In this review, we will discuss the multi-faceted roles of CAFs in tumor-stroma interactions influencing cancer initiation, progression and therapeutic response.

Polysaccharides as therapeutic vehicles in pancreatic cancer

Pancreatic cancer (PC) is highly aggressive, with rising incidence and mortality rates. It has significant therapy obstacles due to the limited clinical options, late-stage identification, dense tumor microenvironment (TME), and resistance to therapy. Recent advances might improve treatment consequences in therapy strategies that target important TME components. Moreover, new polymeric drug delivery techniques based on polysaccharides such as polymeric micelles, liposomes, and nanoparticles enhance the solubility of drugs, drug stability, and tumor-specific targeting, which increase the chances of circumventing resistance and improving the efficacy of treatment. Preclinical research has suggested that by modulating the TME and enhancing the efficacy of chemotherapy, polysaccharide-based therapy, such as RP02-1 and DPLL-functionalized amylose, may help treat PC.

KRT7 promotes pancreatic cancer metastasis by remodeling the extracellular matrix niche through FGF2-fibroblast crosstalk

Pancreatic ductal adenocarcinoma (PDAC) is a devastating cancer with a dismal prognosis due to distant metastasis. Through an analysis of large RNA sequencing and proteomics datasets, we found that high KRT7 expression in PDAC patients was correlated with liver metastasis and poor survival. A functional investigation revealed that the overexpression of KRT7 promoted liver metastasis but did not affect tumor cell proliferation in vivo or in vitro. Analysis of scRNA-Seq data from 24 PDAC samples revealed a negative correlation between KRT7 expression in PDAC cells and cancer-associated fibroblast (CAF) infiltration, and this was further confirmed in orthotopic tumor model mice injected with KRT7-overexpressing PDAC cells, which led the development of to a prometastatic niche with reduced ECM deposition. Mechanistically, KRT7 in PDAC cells promoted the secretion of FGF2, which inhibited CAF proliferation and ECM-related gene transcription through the Wnt/β-catenin pathway. Moreover, targeting FGF2 decreased liver metastasis in vivo. Our study revealed that KRT7 promotes PDAC liver metastasis by remodeling the extracellular matrix niche through FGF2-fibroblast crosstalk and provides a promising strategy for preventing PDAC liver metastasis.

Distinct response to IL-1β blockade in liver- and lung-specific metastasis mouse models of pancreatic cancer with heterogeneous tumor microenvironments

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is characterized by a heterogeneous tumor microenvironment (TME). The mechanism by which this heterogeneity confers resistance against immunotherapy remains unclear. Interleukin- 1β (IL-1β) is a proinflammatory cytokine that regulates heterogeneous cancer associated fibroblast (CAF) phenotype and promotes an immunosuppressive TME. Anti-IL-1β monoclonal antibody significantly enhanced the anti-tumor activity of anti-PD-1 in a preclinical model of PDAC. However, clinical trials have shown limited activity of the anti-IL-1β and anti-PD-1 combination. Therefore, we hypothesize that anti-tumor immune response to the combination of anti-IL-1β and anti-PD-1 antibodies is context-dependent and would be affected by the TME heterogeneity in PDAC.

METHODS

Liver- and lung-specific metastasis mouse models of PDAC were used to investigate the antitumor activity of anti-IL-1β and anti-PD-1 antibodies alone or in combination by ultrasound examination and survival analysis. Their effects on the TME heterogeneity were assessed by flow cytometry and single nuclear RNA sequencing.

RESULTS

The combination of anti-IL-1β and anti-PD-1 antibodies does not slow primary tumor growth but prolongs overall survival and reduces lung metastasis rates in a PDAC orthotopic murine model with lung metastasis tropism. In contrast, combination therapy slows primary tumor growth and prolongs survival, but does not reduce liver metastasis rates in a PDAC murine orthotopic model with liver metastasis tropism. Flow cytometry analysis showed that the combination of anti-IL-1β and anti-PD-1 antibodies restores T cell activation negated by the monotherapies. Mechanistically, in the PDAC model with lung metastasis tropism, but not in the model with liver metastasis tropism, combination treatment reverses an increased trend of immunosuppressive myeloid cells as a result of monotherapy. Single-nuclear RNA sequencing analysis of both organ-specific tumor models demonstrated that anti-IL-1β treatment altered infiltration and function of CAF and immune cells differently. Furthermore, anti-IL-1β treatment modulated cytokine/chemokine ligand-receptor-receptor interactions in the models with different organ-specific metastasis distinctly.

CONCLUSION

This study reveals the differential responses of organ-specific metastasis mouse models of PDAC with distinct TMEs to anti-IL-1β and anti-PD-1 treatments, suggesting that treatment response is context-dependent and affected by TME heterogeneity.

Enhancing the tissue penetration to improve sonodynamic immunotherapy for pancreatic ductal adenocarcinoma using membrane-camouflaged nanoplatform

PURPOSE

Sonodynamic therapy (SDT) is a promising strategy as an "in situ vaccine" to enhance activation of antitumor immune responses in solid tumors. However, the dense extracellular matrix (ECM) in pancreatic ductal adenocarcinoma (PDAC) lead to hypoxia and limited penetration of most drugs, aggravating the immunosuppressive tumor microenvironment and limiting the efficacy of synergistic sonodynamic immunotherapy. Therefore, it is essential to regulate ECM in order to alleviate tumor hypoxia and enhance the efficacy of sonodynamic immunotherapy for PDAC.

METHODS

The CPIM nanoplatform, consisting of a macrophage membrane-coated oxygen and drug delivery system (CM@PFOB-ICG-α-Mangostin), was synthesized using ultrasound and extrusion methods. The in vivo homologous targeting and hypoxia alleviation capabilities of CPIM were evaluated through near-infrared (NIR) imaging and photoacoustic (PA) imaging. The tumor growth inhibition potential and ability to reprogram the tumor microenvironment by the CPIM nanoplatform were also investigated.

RESULTS

Co-delivery of α-Mangostin inhibits CAFs and enhances stromal depletion, thereby facilitating better infiltration of macromolecules. Additionally, the nanoemulsion containing perfluorocarbon (PFC) can target tumor cells and accumulate within them through homologous targeting. The US irradiation results in the rapid release of oxygen, serving as a potential source of sonodynamic therapy for hypoxic tumors. Moreover, CPIM reshapes the immunosuppressive microenvironment increasing the population of cytotoxic T lymphocytes (CTLs), and enhancing their anti-tumor immune response through the use of anti-PDL1 antibodies to block immune checkpoints.

CONCLUSION

The present study offers a potential strategy for the co-delivery of oxygen and α-Mangostin, aiming to enhance the penetration of tumors to improve SDT. This approach effectively addresses the existing limitations of immune checkpoint blockade (ICB) treatment in solid tumors, while simultaneously boosting the immune response through synergistic sonodynamic immunotherapy.

Breakthroughs in nanoparticle-based strategies for pancreatic cancer therapy

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers worldwide, mainly due to its high heterogeneity, resistance to therapy and late diagnosis, with a 5-year survival rate of less than 10%. This dismal prognosis has promoted strategies to develop more effective treatments. Nanoparticle-based strategies have emerged, in the last decades, as a great opportunity because they can enhance drug delivery and promote controlled release, presenting lower side effects than conventional therapeutic regimens. Moreover, nanoparticles can often be modified to target specific cells or to achieve a sustained release of the drugs into the tumor. However, very few nanoparticle-based therapies are clinically approved. Concretely for pancreatic cancer treatment only two nanoformulations have been approved by the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA) so far. Clinical translation of nanoparticles remains a challenge for modern medicine, and in particular for pancreatic cancer therapy, because of the complexity of the disease, and a lack of studies been performed in clinically relevant in vitro and in vivo models. In this review, we have summarized the most recent clinical trials using nanoparticle-based formulations in PDAC, giving a small context of the diverse types of nanoparticles employed and the most recent advancements in the field.

Leveraging epigenetic alterations in pancreatic ductal adenocarcinoma for clinical applications

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy characterized by late detection and poor prognosis. Recent research highlights the pivotal role of epigenetic alterations in driving PDAC development and progression. These changes, in conjunction with genetic mutations, contribute to the intricate molecular landscape of the disease. Specific modifications in DNA methylation, histone marks, and non-coding RNAs are emerging as robust predictors of disease progression and patient survival, offering the potential for more precise prognostic tools compared to conventional clinical staging. Moreover, the detection of epigenetic alterations in blood and other non-invasive samples holds promise for earlier diagnosis and improved management of PDAC. This review comprehensively summarises current epigenetic research in PDAC and identifies persisting challenges. These include the complex nature of epigenetic profiles, tumour heterogeneity, limited access to early-stage samples, and the need for highly sensitive liquid biopsy technologies. Addressing these challenges requires the standardisation of methodologies, integration of multi-omics data, and leveraging advanced computational tools such as machine learning and artificial intelligence. While resource-intensive, these efforts are essential for unravelling the functional consequences of epigenetic changes and translating this knowledge into clinical applications. By overcoming these hurdles, epigenetic research has the potential to revolutionise the management of PDAC and improve patient outcomes.

Cancer associated fibroblasts drive epithelial to mesenchymal transition and classical to basal change in pancreatic ductal adenocarcinoma cells with loss of IL-8 expression

Pancreatic ductal adenocarcinoma (PDAC) carries an extremely poor prognosis, in part resulting from cellular heterogeneity that supports overall tumorigenicity. Cancer associated fibroblasts (CAF) are key determinants of PDAC biology and response to systemic therapy. While CAF subtypes have been defined, the effects of patient-specific CAF heterogeneity and plasticity on tumor cell behavior remain unclear. Here, multi-omics was used to characterize the tumor microenvironment (TME) in tumors from patients undergoing curative-intent surgery for PDAC. In these same patients, matched tumor organoid and CAF lines were established to functionally validate the impact of CAFs on the tumor cells. CAFs were found to drive epithelial-mesenchymal transition (EMT) and a switch in tumor cell classificiaton from classical to basal subtype. Furthermore, we identified CAF-specific interleukin 8 (IL-8) as an important modulator of tumor cell subtype. Finally, we defined neighborhood relationships between tumor cell and T cell subsets.

Near-infrared photoimmunotherapy: mechanisms, applications, and future perspectives in cancer research

Photoimmunotherapy (PIT) involves the targeted delivery of a photosensitizer through antibody conjugation, which, upon binding to its cellular target and activation by external irradiation, induces localized toxicity. This approach addresses several limitations of conventional cancer therapies, such as chemo- and radiotherapies, which result in off-target effects that significantly reduce patient quality of life. Furthermore, PIT improves on the challenges encountered with photodynamic therapy (PDT), such as nonspecific localization of the photosensitizer, which often results in unintended toxicities. Although PIT was first proposed in the early 1980s, its clinical applications have been constrained by limitations in antibody engineering, conjugation chemistries, and optical technologies. However, recent advances in antibody-drug conjugate (ADC) research and the emergence of sophisticated laser technologies have greatly benefited the broader applicability of PIT. Notably, the first near-infrared photoimmunotherapy (NIR-PIT) treatment for head and neck cancer has been approved in Japan and is currently in phase III clinical trials in the USA. A significant advantage of PIT over traditional ADCs in cancer management is the agnostic nature of PDT, making it more adaptable to different tumor types. Specifically, PIT can act on cancer stem cells and cancer cells displaying treatment resistance and aggressive phenotypes-a capability beyond the scope of ADCs alone. This review provides an overview of the mechanism of action of NIR-PIT, highlighting its adaptability and application in cancer therapeutics, and concludes by exploring the potential of PIT in advancing cancer treatments.

Ex-Vivo 3D Cellular Models of Pancreatic Ductal Adenocarcinoma: From Embryonic Development to Precision Oncology

ABSTRACT

Pancreas is a vital gland of gastrointestinal system with exocrine and endocrine secretory functions, interweaved into essential metabolic circuitries of the human body. Pancreatic ductal adenocarcinoma (PDAC) represents one of the most lethal malignancies, with a 5-year survival rate of 11%. This poor prognosis is primarily attributed to the absence of early symptoms, rapid metastatic dissemination, and the limited efficacy of current therapeutic interventions. Despite recent advancements in understanding the etiopathogenesis and treatment of PDAC, there remains a pressing need for improved individualized models, identification of novel molecular targets, and development of unbiased predictors of disease progression. Here we aim to explore the concept of precision medicine utilizing 3-dimensional, patient-specific cellular models of pancreatic tumors and discuss their potential applications in uncovering novel druggable molecular targets and predicting clinical parameters for individual patients.

Spatial transcriptomic analysis drives PET imaging of tight junction protein expression in pancreatic cancer theranostics

Molecular imaging using positron emission tomography (PET) provides sensitive detection and mapping of molecular targets. While cancer-associated fibroblasts and integrins have been proposed as targets for imaging of pancreatic ductal adenocarcinoma (PDAC), herein, spatial transcriptomics and proteomics of human surgical samples are applied to select PDAC targets. We find that selected cancer cell surface markers are spatially correlated and provide specific cancer localization, whereas the spatial correlation between cancer markers and immune-related or fibroblast markers is low. Claudin-4 expression increases ~16 fold in cancer as compared with normal pancreas, and tight junction localization confers low background for imaging in normal tissue. We develop a peptide-based molecular imaging agent targeted to claudin-4 with accumulation to ~25% injected activity per cubic centimeter (IA/cc) in metastases and ~18% IA/cc in tumors. Our work motivates a data-driven approach to selection of molecular targets.

A spheroid whole mount drug testing pipeline with machine-learning based image analysis identifies cell-type specific differences in drug efficacy on a single-cell level

BACKGROUND

The growth and drug response of tumors are influenced by their stromal composition, both in vivo and 3D-cell culture models. Cell-type inherent features as well as mutual relationships between the different cell types in a tumor might affect drug susceptibility of the tumor as a whole and/or of its cell populations. However, a lack of single-cell procedures with sufficient detail has hampered the automated observation of cell-type-specific effects in three-dimensional stroma-tumor cell co-cultures.

METHODS

Here, we developed a high-content pipeline ranging from the setup of novel tumor-fibroblast spheroid co-cultures over optical tissue clearing, whole mount staining, and 3D confocal microscopy to optimized 3D-image segmentation and a 3D-deep-learning model to automate the analysis of a range of cell-type-specific processes, such as cell proliferation, apoptosis, necrosis, drug susceptibility, nuclear morphology, and cell density.

RESULTS

This demonstrated that co-cultures of KP-4 tumor cells with CCD-1137Sk fibroblasts exhibited a growth advantage compared to tumor cell mono-cultures, resulting in higher cell counts following cytostatic treatments with paclitaxel and doxorubicin. However, cell-type-specific single-cell analysis revealed that this apparent benefit of co-cultures was due to a higher resilience of fibroblasts against the drugs and did not indicate a higher drug resistance of the KP-4 cancer cells during co-culture. Conversely, cancer cells were partially even more susceptible in the presence of fibroblasts than in mono-cultures.

CONCLUSION

In summary, this underlines that a novel cell-type-specific single-cell analysis method can reveal critical insights regarding the mechanism of action of drug substances in three-dimensional cell culture models.

Pluripotent stem cell-derived CTLs targeting FGFR3-TACC3 fusion gene in osteosarcoma

Osteosarcoma, a highly aggressive bone cancer, poses significant treatment challenges. This study investigates a novel approach utilizing induced pluripotent stem cells (iPSCs) engineered with the FGFR3-TACC3 fusion gene to generate cytotoxic T lymphocytes (CTLs) targeting osteosarcoma. The aim was to assess the efficacy of iPSC-derived CTLs in combating osteosarcoma progression. Abnormal expression of the FGFR3-TACC3 fusion gene was confirmed in osteosarcoma samples. iPSCs were successfully modified to express the fusion gene and were then differentiated into CTLs. In vitro experiments demonstrated that these modified CTLs effectively killed osteosarcoma cells, induced apoptosis, and inhibited migration and invasion. Findings were validated in in vivo experiments. This study suggests that iPSC-derived CTLs targeting FGFR3-TACC3 hold promise for personalized immunotherapy against osteosarcoma.

Deep Multiple Instance Learning Model to Predict Outcome of Pancreatic Cancer Following Surgery

Background/Objectives: Pancreatic ductal adenocarcinoma (PDAC) is a cancer with very poor prognosis despite early surgical management. To date, only clinical variables are used to predict outcome for decision-making about adjuvant therapy. We sought to generate a deep learning approach based on hematoxylin and eosin (H&E) or hematoxylin, eosin and saffron (HES) whole slides to predict patients' outcome, compare these new entities with known molecular subtypes and question their biological significance; Methods: We used as a training set a retrospective private cohort of 206 patients treated by surgery for PDAC cancer and a validation cohort of 166 non-metastatic patients from The Cancer Genome Atlas (TCGA) PDAC project. We estimated a multi-instance learning survival model to predict relapse in the training set and evaluated its performance in the validation set. RNAseq and exome data from the TCGA PDAC database were used to describe the transcriptomic and genomic features associated with deep learning classification; Results: Based on the estimation of an attention-based multi-instance learning survival model, we identified two groups of patients with a distinct prognosis. There was a significant difference in progression-free survival (PFS) between these two groups in the training set (hazard ratio HR = 0.72 [0.54;0.96]; p = 0.03) and in the validation set (HR = 0.63 [0.42;0.94]; p = 0.01). Transcriptomic and genomic features revealed that the poor prognosis group was associated with a squamous phenotype. Conclusions: Our study demonstrates that deep learning could be used to predict PDAC prognosis and offer assistance in better choosing adjuvant treatment.

Triptolide exhibits dual anti-tumor effects through inhibiting autophagy and extracellular matrix activation in pancreatic cancer

AIM

The tumor microenvironment in pancreatic cancer, characterized by abundant desmoplastic stroma, has been implicated in the failure of chemotherapy. Therefore, developing therapeutic strategies targeting tumor and stromal cells is essential. Triptolide, a natural compound derived from the plant Tripterygium wilfordii, has shown antitumor activity in various cancers, including pancreatic cancer. However, its effects on pancreatic cancer cells and the microenvironment remain unclear. This study aimed to explore the effect of triptolide on tumor cells and the tumor microenvironment in pancreatic cancer.

METHODS

Cell Counting Kit-8, colony formation, apoptosis, and cell cycle assays were performed to determine the effect of triptolide on tumor cells. Additionally, co-culture assays were performed to explore the effects of the compound on cancer-associated fibroblasts (CAFs) in vitro. Orthotopic xenograft and subcutaneous tumor models were used to explore the antitumor and antistromal activation effects of triptolide in vivo. RNA sequencing was performed to identify the pathways involved in these processes in pancreatic cancer cells.

RESULTS

Triptolide inhibited the proliferation of pancreatic cancer cells and attenuated stromal activation in vitro and in vivo. Furthermore, it suppressed autophagy and induced apoptosis in pancreatic cancer cells by inhibiting the secretion of CXCL1. Extracellular matrix formation in CAFs was disrupted by suppressing the paracrine secretion of TGF-β from tumor cells.

CONCLUSION

These findings indicate that triptolide plays a dual antitumor role against tumor cells and CAFs, thus providing new insights into treating pancreatic cancer in the future.

Prospective Comparison of [18F]FDG and [18F]AIF-FAPI-74 PET/CT in the Evaluation of Potentially Resectable Pancreatic Ductal Adenocarcinoma

PURPOSE

Accurate clinical staging of potentially resectable pancreatic ductal adenocarcinoma (PDAC) is critical for establishing optimal treatment strategies. While the efficacy of fluorine-18-fluorodeoxyglucose ([18F]FDG) positron emission tomography/computed tomography (PET/CT) in clinical staging is unclear, PET/CT detecting fibroblast-activation protein (FAP) expression has recently received considerable attention for detecting various tumors, including PDAC, with high sensitivity. We explored the efficacy of [18F]FDG and [18F]AIF-FAPI-74 PET/CT in the initial evaluation of potentially resectable PDAC.

PROCEDURES

Between 2021 and 2022, twenty participants with newly diagnosed potentially resectable PDAC were enrolled. After the initial evaluation with pancreatic CT, [18F]FDG PET/CT, and [18F]AIF-FAPI-74 PET/CT, treatment strategies were determined considering the participant's general status, clinical staging, and resectability. Pathological information from the surgical specimens was only available in 17 participants who underwent curative-intent surgery. Head-to-head comparisons of quantitative radiotracer uptake and diagnostic performance were performed among imaging modalities.

RESULTS

[18F]AIF-FAPI-74 PET/CT showed a significantly higher maximum standardized uptake value than [18F]FDG PET/CT did in evaluating primary pancreatic lesions (median [interquartile range]; 12.6 [10.7-13.7] vs. 6.3 [4.8-9.2]; P < 0.001). In contrast, [18F]AIF-FAPI-74 PET/CT showed a significantly lower mean standardized uptake value than [18F]FDG PET/CT did in evaluating background organ (median [interquartile range]) 0.8 [0.7-0.9] vs. 2.6 [2.3-2.7]; P < 0.001). In addition, the sensitivity of [18F]AIF-FAPI-74 PET/CT in detecting metastatic lymph nodes was higher than that of [18F]FDG PET/CT (50.0% vs. 0.0%; P = 0.026).

CONCLUSION

This study demonstrated that [18F]AIF-FAPI-74 PET/CT could improve the clinical staging of potentially resectable PDAC.

Vitamin D and Pancreatic Ductal Adenocarcinoma-A Review of a Complicated Relationship

INTRODUCTION

From the observation of a negative relationship between UV-B exposure and cancer rates, we hypothesized that vitamin D (VD) may play a protective role in oncogenesis. Moreover, repurposing a well-known and relatively safe drug for conditions with dismal prospects, such as pancreatic ductal adenocarcinoma (PDAC), is a tempting idea. Thus, we aimed to summarize the current knowledge regarding the role of VD in the prevention and treatment of PDAC.

METHODS

We conducted a systematic review of VD and PDAC using Medline-indexed studies accessed through PubMed as the primary data source. This study aimed to identify articles focusing on the role of VD as a risk and prognostic factor for PDAC, mechanistic studies evaluating the effects of VD or vitamin D analogs (VDAs) in PDAC models, and clinical trials on VDAs in PDAC. After the screening, 97 studies were included in the final manuscript.

CONCLUSION

Even though the results from epidemiologic studies were contradictory, basic research has demonstrated that VD can act on PDAC cells either directly, inhibiting proliferation, apoptosis, EMT, migration, invasion, and stemness, or indirectly, through stromal remodeling. A better understanding of the consequences of VD-induced tumor-stroma cross-talk alterations is needed to determine whether VD/VDAs can be used to our own advantage in the treatment of PDAC.

Exploring the role of antigen-presenting cancer-associated fibroblasts and CD74 on the pancreatic ductal adenocarcinoma tumor microenvironment

Pancreatic ductal adenocarcinoma (PDAC) has proven to be a formidable cancer primarily due to its tumor microenvironment (TME). This highly desmoplastic, hypoxic, and pro-inflammatory environment has not only been shown to facilitate the growth and metastasis of PDAC but has also displayed powerful immunosuppressive capabilities. A critical cell involved in the development of the PDAC TME is the fibroblast, specifically the antigen-presenting cancer-associated fibroblast (apCAF). The pro-inflammatory environment of PDAC induces the proliferation of apCAFs, promoting immunosuppression through immune cell inactivation, immune response regulation, and expression of CD74. In conjunction with apCAFs and tumor cells, CD74 serves as a versatile promoter of PDAC by preventing tumor antigen-expression on tumor cells, upregulating the expression of immunosuppressive chemical mediators, and activating proliferative pathways to induce PDAC malignancy. This review will highlight critical mediators and pathways that promote the PDAC stroma and TME with its hypoxic and immunosuppressive properties. Further, we will highlight the nature of apCAFs and CD74, their specific roles in the PDAC TME, and their potential as targets for immunotherapy.

Depicting the cellular complexity of pancreatic adenocarcinoma by Imaging Mass Cytometry: focus on cancer-associated fibroblasts

Introduction

Pancreatic ductal adenocarcinoma (PDAC) represents the complexity of interaction between cancer and cells of the tumor microenvironment (TME). Immune cells affect tumor cell behavior, thus driving cancer progression. Cancer-associated fibroblasts (CAFs) are responsible of the desmoplastic and fibrotic reaction by regulating deposition and remodeling of extracellular matrix (ECM). As tumor-promoting cells abundant in PDAC ECM, CAFs represent promising targets for novel anticancer interventions. However, relevant clinical trials are hampered by the lack of specific markers and elusive differences among CAF subtypes. Indeed, while single-cell transcriptomic analyses have provided important information on the cellular constituents of PDACs and related molecular pathways, studies based on the identification of protein markers in tissues aimed at identifying CAF subtypes and new molecular targets result incomplete.

Methods

Herein, we applied multiplexed Imaging Mass Cytometry (IMC) at single-cell resolution on 8 human PDAC tissues to depict the PDAC composing cells, and profiling immune cells, endothelial cells (ECs), as well as endocrine cells and tumor cells.

Results

We focused on CAFs by characterizing up to 19 clusters distinguished by phenotype, spatiality, and interaction with immune and tumor cells. We report evidence that specific subtypes of CAFs (CAFs 10 and 11) predominantly are enriched at the tumor-stroma interface and closely associated with tumor cells. CAFs expressing different combinations of FAP, podoplanin and cadherin-11, were associated with a higher level of CA19-9. Moreover, we identified specific subsets of FAP+ and podoplanin+/cadherin-11+ CAFs enriched in patients with negative prognosis.

Discussion

The present study provides new general insights into the complexity of the PDAC microenvironment by defining phenotypic heterogeneities and spatial distributions of CAFs, thus suggesting different functions of their subtypes in the PDAC microenvironment.

Unveiling the resistance to therapies in pancreatic ductal adenocarcinoma

Despite the ongoing advances in interventional strategies (surgery, chemotherapy, radiotherapy, and immunotherapy) for managing pancreatic ductal adenocarcinoma (PDAC), the development of therapy refractory phenotypes remains a significant challenge. Resistance to various therapeutic modalities in PDAC emanates from a combination of inherent and acquired factors and is attributable to cancer cell-intrinsic and -extrinsic mechanisms. The critical determinants of therapy resistance include oncogenic signaling and epigenetic modifications that drive cancer cell stemness and metabolic adaptations, CAF-mediated stromagenesis that results in ECM deposition altered mechanotransduction, and secretome and immune evasion. We reviewed the current understanding of these multifaceted mechanisms operating in the PDAC microenvironment, influencing the response to chemotherapy, radiotherapy, and immunotherapy regimens. We then describe how the lessons learned from these studies can guide us to discover novel therapeutic regimens to prevent, delay, or revert resistance and achieve durable clinical responses.

Spatial transcriptomic analysis of primary and metastatic pancreatic cancers highlights tumor microenvironmental heterogeneity

Although the spatial, cellular and molecular landscapes of resected pancreatic ductal adenocarcinoma (PDAC) are well documented, the characteristics of its metastatic ecology remain elusive. By applying spatially resolved transcriptomics to matched primary and metastatic PDAC samples, we discovered a conserved continuum of fibrotic, metabolic and immunosuppressive spatial ecotypes across anatomical regions. We observed spatial tumor microenvironment heterogeneity spanning beyond that previously appreciated in PDAC. Through comparative analysis, we show that the spatial ecotypes exhibit distinct enrichment between primary and metastatic sites, implying adaptability to the local environment for survival and progression. The invasive border ecotype exhibits both pro-tumorigenic and anti-tumorigenic cell-type enrichment, suggesting a potential immunotherapy target. The ecotype heterogeneity across patients emphasizes the need to map individual patient landscapes to develop personalized treatment strategies. Collectively, our findings provide critical insights into metastatic PDAC biology and serve as a valuable resource for future therapeutic exploration and molecular investigations.

Overcoming therapy resistance in pancreatic cancer: New insights and future directions

Pancreatic adenocarcinoma (PDAC) is predicted to become the second leading cause of cancer deaths by 2030 and this is mostly due to therapy failure. Limited treatment options and resistance to standard-of-care (SoC) therapies makes PDAC one of the cancer types with poorest prognosis and survival rates [1,2]. Pancreatic tumors are renowned for their poor response to therapeutic interventions including targeted therapies, chemotherapy and radiotherapy. Herein, we review hallmarks of therapy resistance in PDAC and current strategies aiming to tackle escape mechanisms and to re-sensitize cancer cells to therapy. We will further provide insights on recent advances in the field of drug discovery, nanomedicine, and disease models that are setting the ground for future research.

2D co-culture model reveals a biophysical interplay between activated fibroblasts and cancer cells

The tumor microenvironment (TME) comprises diverse cell types within an altered extracellular matrix (ECM) and plays a pivotal role in metastasis through intricate cell-cell and cell-ECM interactions. Fibroblasts, as key constituents of the TME, contribute significantly to cancer metastasis through their involvement in matrix deposition and remodeling mechanisms, modulated by their quiescent or activated states. Despite their recognized importance, the precise role of fibroblasts in cancer cell invasion remains incompletely understood. In this study, we investigated the impact of fibroblast activity on cancer cell progression using a 2D co-culture model. Michigan Cancer Foundation-7 (MCF7) breast cancer cells were co-cultured with normal human lung fibroblasts (NHLF), both with and without transforming growth factor β (TGFβ) treatment. Traction force microscopy (TFM) was employed to quantify traction and velocity forces associated with cellular migration. We observed that TGFβ-activated fibroblasts form a distinctive ring around cancer cells in co-culture, with increased traction and tension at the cell island boundary. This force distribution is associated with the localization of force-related proteins at these boundary regions, including vinculin and E-cadherin. Metabolic profiling revealed a strong OXPHOS signal specific to the activated fibroblasts, in contrast to normal fibroblasts, which primarily display migratory behavior and a more heterogeneous pattern of forces and metabolic activity in co-culture. Our findings offer valuable insights into the mechanical forces and metabolic dynamics governing cellular migration in the tumor microenvironment, where our co-culture model could complement in vivo studies and enable researchers to explore specific microenvironmental cues for a deeper understanding of TME mechanisms. STATEMENT OF SIGNIFICANCE: Cancer models mimicking the dynamics of tumor microenvironment (TME) are an ideal tool to study cancer mechanisms and treatment. However, the full understanding of how cancer cells interact with their surroundings and other cells is still unknown. To tackle this, we developed a simple yet effective 2D co-culture model that allows us to control the arrangement of cell cultures precisely and use various imaging techniques to study interactions between cancer cells and fibroblasts. Here we could measure cell movements, force distribution, metabolic activity, and protein localization and interplay those factors in vitro. Our model helps us observe the underlying mechanisms between cancer cells and fibroblasts, contributing to our understanding of the dynamics in the TME.

Targeting cancer-associated fibroblasts/tumor cells cross-talk inhibits intrahepatic cholangiocarcinoma progression via cell-cycle arrest

BACKGROUND

Cancer-associated fibroblasts (CAFs), mainly responsible for the desmoplastic reaction hallmark of intrahepatic Cholangiocarcinoma (iCCA), likely have a role in tumor aggressiveness and resistance to therapy, although the molecular mechanisms involved are unknown. Aim of the study is to investigate how targeting hCAF/iCCA cross-talk with a Notch1 inhibitor, namely Crenigacestat, may affect cancer progression.

METHODS

We used different in vitro models in 2D and established new 3D hetero-spheroids with iCCA cells and human (h)CAFs. The results were confirmed in a xenograft model, and explanted tumoral tissues underwent transcriptomic and bioinformatic analysis.

RESULTS

hCAFs/iCCA cross-talk sustains increased migration of both KKU-M213 and KKU-M156 cells, while Crenigacestat significantly inhibits only the cross-talk stimulated migration. Hetero-spheroids grew larger than homo-spheroids, formed by only iCCA cells. Crenigacestat significantly reduced the invasion and growth of hetero- but not of homo-spheroids. In xenograft models, hCAFs/KKU-M213 tumors grew significantly larger than KKU-M213 tumors, but were significantly reduced in volume by Crenigacestat treatment, which also significantly decreased the fibrotic reaction. Ingenuity pathway analysis revealed that genes of hCAFs/KKU-M213 but not of KKU-M213 tumors increased tumor lesions, and that Crenigacestat treatment inhibited the modulated canonical pathways. Cell cycle checkpoints were the most notably modulated pathway and Crenigacestat reduced CCNE2 gene expression, consequently inducing cell cycle arrest. In hetero-spheroids, the number of cells increased in the G2/M cell cycle phase, while Crenigacestat significantly decreased cell numbers in the G2/M phase in hetero but not in homo-spheroids.

CONCLUSIONS

The hCAFs/iCCA cross-talk is a new target for reducing cancer progression with drugs such as Crenigacestat.

Redefining the tumor microenvironment with emerging therapeutic strategies

The environment surrounding a tumor, known as the tumor microenvironment (TME), plays a role in how cancer progresses and responds to treatment. It poses both challenges and opportunities for improving cancer therapy. Recent progress in understanding the TME complexity and diversity has led to approaches for treating cancer. This perspective discusses the strategies for targeting the TME, such as adjusting networks using extracellular vesicles to deliver drugs and enhancing immune checkpoint inhibitors (ICIS) through combined treatments. Furthermore, it highlights adoptive cell transfer (ACT) therapies as an option for tumors. By studying how components of the TME interact and utilizing technologies like single-cell RNA sequencing and spatial transcriptomics, we can develop more precise and efficient treatments for cancer. This article emphasizes the need to reshape the TME to boost antitumor immunity and overcome resistance to therapy, providing guidance for research and clinical practices in precision oncology.

Oncogenic KRAS-Dependent Stromal Interleukin-33 Directs the Pancreatic Microenvironment to Promote Tumor Growth

Pancreatic cancer is characterized by an extensive fibroinflammatory microenvironment. During carcinogenesis, normal stromal cells are converted to cytokine-high cancer-associated fibroblasts (CAF). The mechanisms underlying this conversion, including the regulation and function of fibroblast-derived cytokines, are poorly understood. Thus, efforts to therapeutically target CAFs have so far failed. Herein, we show that signals from epithelial cells expressing oncogenic KRAS-a hallmark pancreatic cancer mutation-activate fibroblast autocrine signaling, which drives the expression of the cytokine IL33. Stromal IL33 expression remains high and dependent on epithelial KRAS throughout carcinogenesis; in turn, environmental stress induces interleukin-33 (IL33) secretion. Using compartment-specific IL33 knockout mice, we observed that lack of stromal IL33 leads to profound reprogramming of multiple components of the pancreatic tumor microenvironment, including CAFs, myeloid cells, and lymphocytes. Notably, loss of stromal IL33 leads to an increase in CD8+ T-cell infiltration and activation and, ultimately, reduced tumor growth. Significance: This study provides new insights into the mechanisms underlying the programming of CAFs and shows that during this process, expression of the cytokine IL33 is induced. CAF-derived IL33 has pleiotropic effects on the tumor microenvironment, supporting its potential as a therapeutic target.

Panoramic tumor microenvironment in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is notorious for its resistance to various treatment modalities. The genetic heterogeneity of PDAC, coupled with the presence of a desmoplastic stroma within the tumor microenvironment (TME), contributes to an unfavorable prognosis. The mechanisms and consequences of interactions among different cell types, along with spatial variations influencing cellular function, potentially play a role in the pathogenesis of PDAC. Understanding the diverse compositions of the TME and elucidating the functions of microscopic neighborhoods may contribute to understanding the immune microenvironment status in pancreatic cancer. As we delve into the spatial biology of the microscopic neighborhoods within the TME, aiding in deciphering the factors that orchestrate this intricate ecosystem. This overview delineates the fundamental constituents and the structural arrangement of the PDAC microenvironment, highlighting their impact on cancer cell biology.

Immune evasion: An imperative and consequence of MYC deregulation

MYC has been implicated in the pathogenesis of a wide range of human tumors and has been described for many years as a transcription factor that regulates genes with pleiotropic functions to promote tumorigenic growth. However, despite extensive efforts to identify specific target genes of MYC that alone could be responsible for promoting tumorigenesis, the field is yet to reach a consensus whether this is the crucial function of MYC. Recent work shifts the view on MYC's function from being a gene-specific transcription factor to an essential stress resilience factor. In highly proliferating cells, MYC preserves cell integrity by promoting DNA repair at core promoters, protecting stalled replication forks, and/or preventing transcription-replication conflicts. Furthermore, an increasing body of evidence demonstrates that MYC not only promotes tumorigenesis by driving cell-autonomous growth, but also enables tumors to evade the host's immune system. In this review, we summarize our current understanding of how MYC impairs antitumor immunity and why this function is evolutionarily hard-wired to the biology of the MYC protein family. We show why the cell-autonomous and immune evasive functions of MYC are mutually dependent and discuss ways to target MYC proteins in cancer therapy.

Pancreatic ductal adenocarcinoma microenvironment: Soluble factors and cancer associated fibroblasts as modulators of NK cell functions

Pancreatic Ductal Adenocarcinoma (PDAC) is the most frequent pancreatic cancer and represents one of the most aggressive human neoplasms. Typically identified at advance stage disease, most PDAC tumors are unresectable and resistant to standard therapies. The immunosuppressive microenvironment in PDAC impedes tumor control but a greater understanding of the complex stromal interactions within the tumor microenvironment (TME) and the development of strategies capable of restoring antitumor effector immune responses could be crucial to fight this aggressive tumor and its spread. Natural Killer (NK) cells play a crucial role in cancer immunosurveillance and represent an attractive target for immunotherapies, both as cell therapy and as a pharmaceutical target. This review describes some crucial components of the PDAC TME (collagens, soluble factors and fibroblasts) that can influence the presence, phenotype and function of NK cells in PDAC patients tumor tissue. This focused overview highlights the therapeutic relevance of dissecting the complex stromal composition to define new strategies for NK cell-based immunotherapies to improve the treatment of PDAC.

EBF1-COX4I2 signaling axis promotes a myofibroblast-like phenotype in cancer-associated fibroblasts (CAFs) and is associated with an immunosuppressive microenvironment

Immunotherapy has limited response rates in colorectal cancer (CRC) due to an immunosuppressive tumor microenvironment (TME). Combining transcriptome sequencing, clinical specimens, and functional experiments, we identified a unique group of CAF subpopulations (COX4I2 + ) with inhibited mitochondrial respiration and enhanced glycolysis. Through bioinformatics predictions and luciferase reporter assays, we determined that EBF1 can upstreamly regulate COX4I2 transcription. COX4I2 + CAFs functionally and phenotypically resemble myofibroblasts, are important for the formation of the fibrotic TME, and are capable of activating the M2 phenotype of macrophages. In vitro experiments demonstrated that COX4I2 + CAFs promote immunosuppressive TME by blocking CD8 + T cell infiltration and inducing CD8 + T cell dysfunction. Using multiple independent cohorts, we also found a strong correlation between the immunotherapy response rate of CRC patients and COX4I2 expression in their tumors. Our results identify a CAF subpopulation characterized by activation of the EBF1-COX4I2 axis, and this group of CAFs can be targeted to improve cancer immunotherapy outcomes.

Resveratrol inhibits pancreatic cancer proliferation and metastasis by depleting senescent tumor-associated fibroblasts

BACKGROUND

Pancreatic cancer, a formidable gastrointestinal neoplasm, is characterized by its insidious onset, rapid progression, and resistance to treatment, which often lead to a grim prognosis. While the complex pathogenesis of pancreatic cancer is well recognized, recent attention has focused on the oncogenic roles of senescent tumor-associated fibroblasts. However, their precise role in pancreatic cancer remains unknown. Resveratrol is a natural polyphenol known for its multifaceted biological actions, including antioxidative and neuroprotective properties, as well as its potential to inhibit tumor proliferation and migration. Our current investigation builds on prior research and reveals the remarkable ability of resveratrol to inhibit pancreatic cancer proliferation and metastasis.

AIM

To explore the potential of resveratrol in inhibiting pancreatic cancer by targeting senescent tumor-associated fibroblasts.

METHODS

Immunofluorescence staining of pancreatic cancer tissues revealed prominent coexpression of α-SMA and p16. HP-1 expression was determined using immunohistochemistry. Cells were treated with the senescence-inducing factors known as 3CKs. Long-term growth assays confirmed that 3CKs significantly decreased the CAF growth rate. Western blotting was conducted to assess the expression levels of p16 and p21. Immunofluorescence was performed to assess LaminB1 expression. Quantitative real-time polymerase chain reaction was used to measure the levels of several senescence-associated secretory phenotype factors, including IL-4, IL-6, IL-8, IL-13, MMP-2, MMP-9, CXCL1, and CXCL12. A scratch assay was used to assess the migratory capacity of the cells, whereas Transwell assays were used to evaluate their invasive potential.

RESULTS

Specifically, we identified the presence of senescent tumor-associated fibroblasts within pancreatic cancer tissues, linking their abundance to cancer progression. Intriguingly, Resveratrol effectively eradicated these fibroblasts and hindered their senescence, which consequently impeded pancreatic cancer progression.

CONCLUSION

This groundbreaking discovery reinforces Resveratrol's stature as a potential antitumor agent and positions senescent tumor-associated fibroblasts as pivotal contenders in future therapeutic strategies against pancreatic cancer.

Development of Dual Diagnostic-Therapeutic Nanoformulation Effective Against Pancreatic Cancer in Animal Model

Purpose

Erythrocytes and fibroblasts in the pancreatic cancer tumor microenvironment promote tumor cell growth and invasion by providing nutrients and promoting immunosuppression. Additionally, they form a barrier against the penetration of chemotherapeutic drugs. Therefore, the search for diversified tumor-targeting materials plays an essential role in solving the above problems.

Methods

Physicochemical characterization of Graphene fluorescent nanoparticles (GFNPs) and nanomedicines were analyzed by transmission electron microscopy (TEM), elemental analyzers and ultraviolet fluorescence (UV/FL) spectrophotometer. Localization of GFNPs in cell and tissue sections imaged with laser confocal microscope, fluorescence scanner and small animal in vivo imager. Qualitative detection and quantitative detection of GFNPs and GFNPs-GEM were performed using High performance liquid chromatography (HPLC).

Results

Based on the 3 nm average dimensions, GFNPs penetrate vascular endothelial cells and smooth muscle cells, achieve up to label 30% tumor cells and 60% cancer-associated fibroblasts (CAFs) cells, and accurately label mature red blood cells in the tumor microenvironment. In orthotopic transplanted pancreatic cancer models, the fluorescence intensity of GFNPs in tumors showed a positive correlation with the cycle size of tumor development. The differential spatial distribution of GFNPs in three typical clinical pancreatic cancer samples demonstrated their diagnostic potential. To mediate the excellent targeting properties of GFNPs, we synthesized a series of nanomedicines using popular chemotherapeutic drugs, in which complex of GFNPs and gemcitabine (GFNPs-GEM) possessed stability in vivo and exhibited effective reduction of tumor volume and fewer side effects.

Conclusion

GFNPs with multiple targeting tumor microenvironments in pancreatic cancer possess diagnostic efficiency and therapeutic potential.

The Role of Tumor Microenvironment in Pancreatic Cancer Immunotherapy: Current Status and Future Perspectives

Pancreatic cancer comprises different subtypes, where most cases include ductal adenocarcinoma (PDAC). It is one of the deadliest tumor types, with a poor prognosis. In the majority of patients, the disease has already spread by the time of diagnosis, making full recovery unlikely and increasing mortality risk. Despite developments in its detection and management, including chemotherapy, radiotherapy, and targeted therapies as well as advances in immunotherapy, only in about 13% of PDAC patients does the overall survival exceed 5 years. This may be attributed, at least in part, to the highly desmoplastic tumor microenvironment (TME) that acts as a barrier limiting perfusion, drug delivery, and immune cell infiltration and contributes to the establishment of immunologically 'cold' conditions. Therefore, there is an urgent need to unravel the complexity of the TME that promotes PDAC progression and decipher the mechanisms of pancreatic tumors' resistance to immunotherapy. In this review, we provide an overview of the major cellular and non-cellular components of PDAC TME, as well as their biological interplays. We also discuss the current state of PDAC therapeutic treatments and focus on ongoing and future immunotherapy efforts and multimodal treatments aiming at remodeling the TME to improve therapeutic efficacy.

Spatial proteomic profiling elucidates immune determinants of neoadjuvant chemo-immunotherapy in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) presents significant clinical and therapeutic challenges due to its aggressive nature and generally poor prognosis. We initiated a Phase II clinical trial (ChiCTR1900027160) to assess the efficacy of a pioneering neoadjuvant chemo-immunotherapy regimen comprising programmed death-1 (PD-1) blockade (Toripalimab), nanoparticle albumin-bound paclitaxel (nab-paclitaxel), and the oral fluoropyrimidine derivative S-1, in patients with locally advanced ESCC. This study uniquely integrates clinical outcomes with advanced spatial proteomic profiling using Imaging Mass Cytometry (IMC) to elucidate the dynamics within the tumor microenvironment (TME), focusing on the mechanistic interplay of resistance and response. Sixty patients participated, receiving the combination therapy prior to surgical resection. Our findings demonstrated a major pathological response (MPR) in 62% of patients and a pathological complete response (pCR) in 29%. The IMC analysis provided a detailed regional assessment, revealing that the spatial arrangement of immune cells, particularly CD8+ T cells and B cells within tertiary lymphoid structures (TLS), and S100A9+ inflammatory macrophages in fibrotic regions are predictive of therapeutic outcomes. Employing machine learning approaches, such as support vector machine (SVM) and random forest (RF) analysis, we identified critical spatial features linked to drug resistance and developed predictive models for drug response, achieving an area under the curve (AUC) of 97%. These insights underscore the vital role of integrating spatial proteomics into clinical trials to dissect TME dynamics thoroughly, paving the way for personalized and precise cancer treatment strategies in ESCC. This holistic approach not only enhances our understanding of the mechanistic basis behind drug resistance but also sets a robust foundation for optimizing therapeutic interventions in ESCC.

New insights into cancer pathology learned from the dynamics of cancer-associated fibroblasts

Paget's "Seed and Soil" theory, proposed in 1889, emphasizes the importance of the microenvironment where cancer cells grow in metastatic sites. Over a century later, this concept remains a cornerstone in comprehending cancer biology and devising treatment strategies. The "Seed and Soil" theory, which initially explained how cancer spreads to distant organs, now also applies to the tumor microenvironment (TME) within primary tumors. This theory emphasizes the critical interaction between cancer cells ("seeds") and their surrounding environment ("soil") and how this interaction affects both tumor progression within the primary site and at metastatic sites. An important point to note is that the characteristics of the TME are not static but dynamic, undergoing substantial changes during tumor progression and after treatment with therapeutic drugs. Cancer-associated fibroblasts (CAFs), recognized as the principal noncancerous cellular component within the TME, play multifaceted roles in tumor progression including promoting angiogenesis, remodeling the extracellular matrix, and regulating immune responses. In this comprehensive review, we focus on the findings regarding how the dynamics of CAFs contribute to cancer progression and drug sensitivity. Understanding the dynamics of CAFs could provide new insights into cancer pathology and lead to important advancements in cancer research and treatment.

3Din vitromodeling of the exocrine pancreatic unit using tomographic volumetric bioprinting

Pancreatic ductal adenocarcinoma (PDAC) is the most common type of pancreatic cancer, a leading cause of cancer-related deaths globally. Initial lesions of PDAC develop within the exocrine pancreas' functional units, with tumor progression driven by interactions between PDAC and stromal cells. Effective therapies require anatomically and functionally relevantin vitrohuman models of the pancreatic cancer microenvironment. We employed tomographic volumetric bioprinting, a novel biofabrication method, to create human fibroblast-laden constructs mimicking the tubuloacinar structures of the exocrine pancreas. Human pancreatic ductal epithelial (HPDE) cells overexpressing the KRAS oncogene (HPDE-KRAS) were seeded in the multiacinar cavity to replicate pathological tissue. HPDE cell growth and organization within the structure were assessed, demonstrating the formation of a thin epithelium covering the acini inner surfaces. Immunofluorescence assays showed significantly higher alpha smooth muscle actin (α-SMA) vs. F-actin expression in fibroblasts co-cultured with cancerous versus wild-type HPDE cells. Additionally,α-SMA expression increased over time and was higher in fibroblasts closer to HPDE cells. Elevated interleukin (IL)-6 levels were quantified in supernatants from co-cultures of stromal and HPDE-KRAS cells. These findings align with inflamed tumor-associated myofibroblast behavior, serving as relevant biomarkers to monitor early disease progression and target drug efficacy. To our knowledge, this is the first demonstration of a 3D bioprinted model of exocrine pancreas that recapitulates its true 3-dimensional microanatomy and shows tumor triggered inflammation.

Surface-Enhanced Raman Scattering Monitoring of Tryptophan Dynamics in 3D Pancreatic Tumor Models

In the intricate landscape of the tumor microenvironment, both cancer and stromal cells undergo rapid metabolic adaptations to support their growth. Given the relevant role of the metabolic secretome in fueling tumor progression, its unique metabolic characteristics have gained prominence as potential biomarkers and therapeutic targets. As a result, rapid and accurate tools have been developed to track metabolic changes in the tumor microenvironment with high sensitivity and resolution. Surface-enhanced Raman scattering (SERS) is a highly sensitive analytical technique and has been proven efficient toward the detection of metabolites in biological media. However, profiling secreted metabolites in complex cellular environments such as those in tumor-stroma 3D in vitro models remains challenging. To address this limitation, we employed a SERS-based strategy to investigate the metabolic secretome of pancreatic tumor models within 3D cultures. We aimed to monitor the immunosuppressive potential of stratified pancreatic cancer-stroma spheroids as compared to 3D cultures of either pancreatic cancer cells or cancer-associated fibroblasts, focusing on the metabolic conversion of tryptophan into kynurenine by the IDO-1 enzyme. We additionally sought to elucidate the dynamics of tryptophan consumption in correlation with the size, temporal evolution, and composition of the spheroids, as well as assessing the effects of different drugs targeting the IDO-1 machinery. As a result, we confirm that SERS can be a valuable tool toward the optimization of cancer spheroids, in connection with their tryptophan metabolizing capacity, potentially allowing high-throughput spheroid analysis.

Breaking Down Barriers in Drug Delivery by Stromal Remodeling Approaches in Pancreatic Cancer

Pancreatic cancer remains a formidable challenge in oncology due to its aggressive nature and limited treatment options. The dense stroma surrounding pancreatic tumors not only provides structural support but also presents a formidable barrier to effective therapy, hindering drug penetration and immune cell infiltration. This review delves into the intricate interplay between stromal components and cancer cells, highlighting their impact on treatment resistance and prognosis. Strategies for stromal remodeling, including modulation of cancer-associated fibroblasts (CAFs), pancreatic stellate cells (PSCs) activation states, and targeting extracellular matrix (ECM) components, are examined for their potential to enhance drug penetration and improve therapeutic efficacy. Integration of stromal remodeling with conventional therapies, such as chemotherapy and immunotherapy, is discussed along with the emerging field of intelligent nanosystems for targeted drug delivery. This comprehensive overview underscores the importance of stromal remodeling in pancreatic cancer treatment and offers insights into promising avenues for future research and clinical translation.

Novel selective inhibitors of macropinocytosis-dependent growth in pancreatic ductal carcinoma

Macropinocytosis is a cellular process that enables cells to engulf extracellular material, such as nutrients, growth factors, and even whole cells. It is involved in several physiological functions as well as pathological conditions. In cancer cells, macropinocytosis plays a crucial role in promoting tumor growth and survival under nutrient-limited conditions. In particular KRAS mutations have been identified as main drivers of macropinocytosis in pancreatic, breast, and non-small cell lung cancers. We performed a high-content screening to identify inhibitors of macropinocytosis in pancreatic ductal adenocarcinoma (PDAC)-derived cells, aiming to prevent nutrient scavenging of PDAC tumors. The screening campaign was conducted in a well-known pancreatic KRAS-mutated cell line (MIAPaCa-2) cultured under nutrient deprivation and using FITC-dextran to precisely quantify macropinocytosis. We assembled a collection of 3584 small molecules, including drugs approved by the Food and Drug Administration (FDA), drug-like molecules against molecular targets, kinase-targeted compounds, and molecules designed to hamper protein-protein interactions. We identified 28 molecules that inhibited macropinocytosis, with potency ranging from 0.4 to 29.9 μM (EC50). A few of them interfered with other endocytic pathways, while 11 compounds did not and were therefore considered specific "bona fide" macropinocytosis inhibitors and further characterized. Four compounds (Ivermectin, Tyrphostin A9, LY2090314, and Pyrvinium Pamoate) selectively hampered nutrient scavenging in KRAS-mutated cancer cells. Their ability to impair albumin-dependent proliferation was replicated both in different 2D cell culture systems and 3D organotypic models. These findings provide a new set of compounds specifically targeting macropinocytosis, which could have therapeutic applications in cancer and infectious diseases.

Small Cell Lung Cancer-An Update on Chemotherapy Resistance

OPINION STATEMENT

Compared to other types of lung cancer, small cell lung cancer (SCLC) exhibits aggressive characteristics that promote drug resistance. Despite platinum-etoposide chemotherapy combined with immunotherapy being the current standard treatment, the rapid development of drug resistance has led to unsatisfactory clinical outcomes. This review focuses on the mechanisms contributing to the chemotherapy resistance phenotype in SCLC, such as increased intra-tumoral heterogeneity, alterations in the tumor microenvironment, changes in cellular metabolism, and dysregulation of apoptotic pathways. A comprehensive understanding of these drug resistance mechanisms in SCLC is imperative for ushering in a new era in cancer research, which will promise revolutionary advancements in cancer diagnosis and treatment methodologies.

ITGB6 promotes pancreatic fibrosis and aggravates the malignant process of pancreatic cancer via JAK2/STAT3 signaling pathway

Integrin β6 (ITGB6) is upregulated in multiple tumor types and elevated ITGB6 levels have been detected in patients with chronic pancreatitis. However, the role of ITGB6 in pancreatic fibrosis and cancer remains to be elucidated. In the present study, ITGB6 expression was assessed using western blotting and qRT-PCR. Besides, cell proliferation, cycling, migration, and invasion were evaluated using CCK-8, flow cytometry, wound healing, and transwell assays, respectively. The expression of fibrosis and JAK2/STAT3 signaling markers was detected by western blotting and immunofluorescence analysis. Moreover, nude mice were subcutaneously injected with co-cultured cell suspensions to establish an in vivo model. The results showed that ITGB6 was highly expressed in pancreatic cancer tissues and TGF-β-induced pancreatic stellate cells (PSCs). Inhibition of ITGB6 expression in PSCs resulted in clear inhibition of activated PSC proliferation, migration, and fibrogenesis. Additionally, reduced ITGB6 expression inhibits the JAK2/STAT3 signaling pathway. Interestingly, activators of the JAK2/STAT3 signaling pathway reversed the effects of ITGB6 disruption on PSCs. Activated PSCs notably promoted the proliferation, invasion, and migration of pancreatic cancer cells in a co-culture assay. In contrast, activated PSCs with low ITGB6 expression failed to significantly affect the malignancy of pancreatic cancer cells. Moreover, in vivo results showed that interference with ITGB6 inhibited the activation of PSCs and promoted the development of pancreatic cancer. Silencing ITGB6 inhibited the proliferation, migration, and fibrosis-like effects of activated PSCs and indirectly inhibited the metastasis and malignant process of pancreatic cancer by inhibiting the JAK2/STAT3 signaling pathway. Therefore, ITGB6 is a potential candidate target for pancreatic cancer prevention and treatment.

Expression of versican isoforms V0/V1 by pancreatic cancer associated fibroblasts increases fibroblast proliferation

BACKGROUND

Versican is a large extracellular matrix (ECM) proteoglycan with four isoforms V0-3. Elevated V0/V1 levels in breast cancer and glioma regulate cell migration and proliferation, but the role of versican in pancreatic ductal adenocarcinoma (PDAC) remains unclear.

METHODS

In this study, we evaluated the expression levels of versican isoforms, as well as their cellular source and interacting partners, in vivo, in human and mouse primary and metastatic PDAC tumours and in vitro, in pancreatic tumour cells and fibroblasts using immunostaining, confocal microscopy and qPCR techniques. We also investigated the effect of versican expression on fibroblast proliferation and migration using genetic and pharmacological approaches.

RESULTS

We found that versican V0/V1 is highly expressed by cancer-associated fibroblasts (CAFs) in mouse and human primary and metastatic PDAC tumours. Our data also show that exposing fibroblasts to tumour-conditioned media upregulates V0 and V1 expressions, while Verbascoside (a CD44 inhibitor) downregulates V0/V1 expression. Importantly, V0/V1 knockdown significantly inhibits fibroblast proliferation. Mechanistically, we found that inhibiting hyaluronan synthesis does not affect versican co-localisation with CD44 in fibroblasts.

CONCLUSION

CAFs express high levels of versican V0/V1 in primary and liver metastatic PDAC tumours and versican V0/V1 supports fibroblast proliferation.

Anakinra-Loaded Sphingomyelin Nanosystems Modulate In Vitro IL-1-Dependent Pro-Tumor Inflammation in Pancreatic Cancer

Pancreatic cancer is a very aggressive disease with a dismal prognosis. The tumor microenvironment exerts immunosuppressive activities through the secretion of several cytokines, including interleukin (IL)-1. The IL-1/IL-1 receptor (IL-1R) axis is a key regulator in tumor-promoting T helper (Th)2- and Th17-type inflammation. Th2 cells are differentiated by dendritic cells endowed with Th2-polarizing capability by the thymic stromal lymphopoietin (TSLP) that is secreted by IL-1-activated cancer-associated fibroblasts (CAFs). Th17 cells are differentiated in the presence of IL-1 and other IL-1-regulated cytokines. In pancreatic cancer, the use of a recombinant IL-1R antagonist (IL1RA, anakinra, ANK) in in vitro and in vivo models has shown efficacy in targeting the IL-1/IL-1R pathway. In this study, we have developed sphingomyelin nanosystems (SNs) loaded with ANK (ANK-SNs) to compare their ability to inhibit Th2- and Th17-type inflammation with that of the free drug in vitro. We found that ANK-SNs inhibited TSLP and other pro-tumor cytokines released by CAFs at levels similar to ANK. Importantly, inhibition of IL-17 secretion by Th17 cells, but not of interferon-γ, was significantly higher, and at lower concentrations, with ANK-SNs compared to ANK. Collectively, the use of ANK-SNs might be beneficial in reducing the effective dose of the drug and its toxic effects.

A Ketogenic Diet Sensitizes Pancreatic Cancer to Inhibition of Glutamine Metabolism

Pancreatic cancer is the third leading cause of cancer death in the United States, and while conventional chemotherapy remains the standard treatment, responses are poor. Safe and alternative therapeutic strategies are urgently needed 1 . A ketogenic diet has been shown to have anti-tumor effects across diverse cancer types but will unlikely have a significant effect alone. However, the diet shifts metabolism in tumors to create new vulnerabilities that can be targeted (1). Modulators of glutamine metabolism have shown promise in pre-clinical models but have failed to have a marked impact against cancer in the clinic. We show that a ketogenic diet increases TCA and glutamine-associated metabolites in murine pancreatic cancer models and under metabolic conditions that simulate a ketogenic diet in vitro. The metabolic shift leads to increased reliance on glutamine-mediated anaplerosis to compensate for low glucose abundance associated with a ketogenic diet. As a result, glutamine metabolism inhibitors, such as DON and CB839 in combination with a ketogenic diet had robust anti-cancer effects. These findings provide rationale to study the use of a ketogenic diet with glutamine targeted therapies in a clinical context.

Pancreatic cancer cell- and cancer-associated fibroblast-derived exosomes in disease progression, metastasis, and therapy

Exosomes play a crucial role in the progression and spread of pancreatic cancer, serving not only as promoters of tumor growth and organ-specific metastasis but also as promising biomarkers and targets for treatment. These nano vesicles enhance intercellular communication by transferring bioactive molecules, such as proteins and RNAs, between cells. This process significantly affects cancer cell dynamics, including their proliferation, migration, and invasion, while also contributing to drug resistance. Our review focuses on the crucial interactions between cancer cells and fibroblasts mediated by exosomes within the pancreatic cancer microenvironment. We delve into how exosomes from both cancer-associated fibroblasts and the cancer cells themselves drive tumor progression through various mechanisms, such as epithelial-mesenchymal transition and facilitating metastasis to specific organs like the lungs and liver. The potential of leveraging exosomes for therapeutic interventions is also explored, highlighting the importance of understanding their role in cell communication as a step forward in developing more effective pancreatic cancer treatments.

Single-cell multiomics profiling reveals heterogeneous transcriptional programs and microenvironment in DSRCTs

Desmoplastic small round cell tumor (DSRCT) is a rare, aggressive sarcoma driven by the EWSR1::WT1 chimeric transcription factor. Despite this unique oncogenic driver, DSRCT displays a polyphenotypic differentiation of unknown causality. Using single-cell multi-omics on 12 samples from five patients, we find that DSRCT tumor cells cluster into consistent subpopulations with partially overlapping lineage- and metabolism-related transcriptional programs. In vitro modeling shows that high EWSR1::WT1 DNA-binding activity associates with most lineage-related states, in contrast to glycolytic and profibrotic states. Single-cell chromatin accessibility analysis suggests that EWSR1::WT1 binding site variability may drive distinct lineage-related transcriptional programs, supporting some level of cell-intrinsic plasticity. Spatial transcriptomics reveals that glycolytic and profibrotic states specifically localize within hypoxic niches at the periphery of tumor cell islets, suggesting an additional role of tumor cell-extrinsic microenvironmental cues. We finally identify a single-cell transcriptomics-derived epithelial signature associated with improved patient survival, highlighting the clinical relevance of our findings.

Current and future immunotherapeutic approaches in pancreatic cancer treatment

Pancreatic cancer is a major cause of cancer-related death, but despondently, the outlook and prognosis for this resistant type of tumor have remained grim for a long time. Currently, it is extremely challenging to prevent or detect it early enough for effective treatment because patients rarely exhibit symptoms and there are no reliable indicators for detection. Most patients have advanced or spreading cancer that is difficult to treat, and treatments like chemotherapy and radiotherapy can only slightly prolong their life by a few months. Immunotherapy has revolutionized the treatment of pancreatic cancer, yet its effectiveness is limited by the tumor's immunosuppressive and hard-to-reach microenvironment. First, this article explains the immunosuppressive microenvironment of pancreatic cancer and highlights a wide range of immunotherapy options, including therapies involving oncolytic viruses, modified T cells (T-cell receptor [TCR]-engineered and chimeric antigen receptor [CAR] T-cell therapy), CAR natural killer cell therapy, cytokine-induced killer cells, immune checkpoint inhibitors, immunomodulators, cancer vaccines, and strategies targeting myeloid cells in the context of contemporary knowledge and future trends. Lastly, it discusses the main challenges ahead of pancreatic cancer immunotherapy.