Emerging evidence suggests that chemotherapy can accumulate senescent-like cells within tumor tissues, a phenomenon linked to therapy resistance. The aim of this study is to analyze the senescence-like state of after-treatment persistent cells associated with KRAS mutational status to offer a therapeutic strategy to target these cells in pancreatic ductal adenocarcinoma (PDAC).

Three commercial cell lines and five patient-derived primary cell cultures with different KRAS statuses were studied following gemcitabine treatment. Senescence-like status was assessed using SA-β-gal, together with cell cycle regulators such as p21. Additionally, KRAS mutations were modulated using MRTX1133 and AMG-510, and the signaling pathways ERK and AKT were analyzed and modulated in vitro. Finally, p21 expression, associated with the senescence-like state, on patient outcomes and treatment response was analyzed in publicly available bulk RNA-seq and single-nucleus datasets.

We observed an overexpression of p21 alongside an increase in SA-β-gal signal in response to gemcitabine treatment, indicating the induction of a senescence-like state. Specific inhibition of KRAS G12D or G12C mutations reduced SA-β-gal signal and sensitized PDAC cells to gemcitabine. Moreover, ERK inhibition but not AKT inhibition decreased SA-β-gal signal. Additionally, we characterized p21 expression levels in relation to patient outcomes and found that they are modulated by treatment.

This dual-targeted therapeutic strategy holds promises for overcoming the challenges posed by KRAS-driven cancers, particularly in addressing the formidable obstacle of pancreatic cancer.

Treatment of advanced stage cancers is extremely challenging, and more effective systemic therapy is needed. Oncolytic adenoviruses (OAds) are one of the most promising anti-cancer agents. However, systemic delivery of OAd is challenging due to the low transduction in tumor cells caused by non-selective distribution and sequestration by non-target organs. To overcome this issue, we have previously generated a mesothelin (MSLN)-targeted OAd (AdML-VTIN). Here, we are reporting the potential of MSLN-targeted OAd as an agent for novel systemic treatment using MSLN-expressing lung and pancreatic cancer models. The in vivo biodistribution of AdML-VTIN after intravenous injection showed significantly lower liver sequestration compared to the wild type of OAd (AdML-5WT). By day 7, the intratumoral viral copy number of AdML-VTIN was significantly higher than that of AdML-5WT. For therapeutic efficacy, systemically injected AdML-VTIN exhibited statistically significant anti-tumor effects in both lung and pancreatic cancer xenograft tumor models. In addition, we tested the effect of preexisting immunity using human serum. In a neutralization assay, AdML-VTIN was more resistant to preexisting antibodies, compared to Ad5-WT. Interestingly, the hemagglutination profile of AdML-VTIN was also changed. Our results indicate that MSLN-targeted OAd has great potential to facilitate systemic therapy of advanced cancers.

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.

Pancreatic cancer, one of the most lethal malignant tumors, is greatly challenged by poor drug delivery efficiency because of the dense and intricate desmoplastic stroma. Given the abnormal expression of scavenger receptor B type 1 (SR-B1) and the dense collagen I (COL1)-enriched extracellular matrix (ECM) barrier in pancreatic tumors, we developed four BLPs with regular chain-length of phosphatidylcholine (PC) (BLP-M, BLP-S, BLP-P, and BLP-H) to enhance their intratumoral delivery for chemotherapy. With the increase of PC chain-length in BLPs, these BLPs exhibited regular tendency of increased affinity to COL1, reduced diffusion capacity in COL1 hydrogel, lessened tumor accumulation and intratumor distribution, and declined efficacy of prolonging survival in the orthotopic pancreatic cancer model. Particularly, the DMPC-based BLP-M system showed the lowest affinity to COL1 and the highest diffusion capacity in the COL1-based ECM barrier, thereby causing the best efficacy of specific tumor accumulation, intratumor delivery, and survival prolongation in an orthotopic pancreatic tumor model. Thereby, this study provided substantial insights into the targeting and intratumor delivery in pancreatic cancer, and DMPC-based BLPs represented an encouraging delivery platform for effective cancer chemotherapy.

The mechanism by which glycans in pancreatic ductal adenocarcinoma (PDAC) interact with human endogenous lectins in the tumor microenvironment remains largely unknown. This study aimed to identify endogenous lectins that recognize and bind to pancreatic ductal adenocarcinomas. The reactivity of 43 human endogenous lectins belonging to the Galectin, Siglec, and C-type lectin families in PDAC cell lines and clinical PDAC samples was analyzed using flow cytometry and immunostaining of tissues. C-type lectin domain family 10 member A (CLEC10A), a C-type lectin, was a candidate endogenous lectin with high reactivity in some pancreatic cancer cells. CLEC10A lectin bound in approximately 60% of 113 clinical pancreatic cancer tissue sections. Immunohistochemistry with anti-CLEC10A antibody showed that CLEC10A was mainly expressed in CD163-positive monocytic cells. Of the 57 patients (out of 113) who achieved R0 surgical resection at stage II/III, those with high CLEC10A expression on macrophages and CLEC10A ligand expression on PDAC cells had significantly shorter overall survival. CLEC10A is a human lectin receptor for pancreatic ductal adenocarcinoma. The coexistence of CLEC10A-expressing cells in pancreatic cancer tissues and CLEC10A ligands on pancreatic cancer cells indicates poor prognosis.

Background: Pancreatic ductal adenocarcinoma (PDAC), which has a poor prognosis, involves an overabundance of fibroblasts and extracellular matrix. Cancer-associated fibroblasts (CAFs) are critical for providing structural support by secreting soluble factors and extracellular matrix proteins into the stroma. We assessed the potential of near-infrared photoimmunotherapy (NIR-PIT) targeting CAFs in PDAC. Methods: PDAC cells (Capan-1 and SUIT-2) and CAFs (hPSC-5) were used. Anti-human fibroblast activation protein (FAP)/podoplanin (PDPN) antibodies were used to bind to CAFs and conjugates with the specific photosensitizer IRDye®700DX (IR700) to investigate the effects of NIR-PIT. Thereafter, BALB/c Slc-nu/nu mice were transplanted with Capan-1 and/or CAFs and treated with gemcitabine (GEM) with or without NIR-PIT. Results: The binding rate of anti-FAP antibody-AlexaFluor®488 conjugate to hPSC-5 cells was high, whereas that of the anti-PDPN antibody-conjugate was not. The incubation of anti-FAP antibody-IR700 conjugate (αFAP-IR700) with hPSC-5 cells for 3 h led to maximal fluorescence on the surface of hPSC-5 cells. When NIR-PIT with αFAP-IR700 was performed in the co-culture group of Capan-1 and hPSC-5 cells, the proliferative capacity of Capan-1 cells decreased to the same level as that when Capan-1 cells were cultured alone (p < 0.05). In vivo, compared with the GEM group, the NIR-PIT with the GEM group showed a significant reduction in the tumor volume (day 28: 79 vs. 382 mm3, p < 0.05). Tumor volumes in the NIR-PIT group were not reduced compared with those in the control group. Conclusions: Combining NIR-PIT with conventional chemotherapy to target CAFs may enhance the anticancer effects on PDAC.

Pancreatic cancer is known for its high invasiveness and metastasis, making rapid visualization and precise treatment critical for improving patient outcomes. Current diagnostic tools lack abilities to provide rapid and accurate tumor localization, particularly for real-time intraoperative guidance. To address this gap, the study has developed a novel Förster Resonance Energy Transfer (FRET)-mediated dual-ratiometric near-infrared fluorescence (NIRF)/photoacoustic (PA) bimodal probe, SiRho-SHD-NTR, specifically designed for the fast and accurate navigation of pancreatic tumor resection. The probe, due to its excellent binding affinity with nitroreductase (NTR), can rapidly reach response saturation. Cellular experiments demonstrate that the probe rapidly and efficiently penetrates cancer cells, enhancing the effectiveness of PA imaging for preliminary diagnosis and tumor localization, while also enabling the rapid visualization of pancreatic tumors through NIRF imaging. Leveraging the rapid response characteristics of the probe to NTR, the study achieves precise tumor imaging in orthotopic pancreatic cancer mice by spraying the probe, within ≈5 min. More importantly, the probe even allows for the fast visualization of metastatic tumors and fluorescence-guided surgical resection. It is believed that SiRho-SHD-NTR will offer a promising method in the rapid visualization of pancreatic cancer and provide a powerful tool for imaging-guided tumor surgery, targeting both primary and metastatic tumors.

Pancreatic ductal adenocarcinoma (PDAC) has one of the lowest 5-year survival rates of all cancers, and limited treatment options exist. Immunotherapy is effective in some cancer types, but the immunosuppressive tumor microenvironment (TME) of PDAC is a barrier to effective immunotherapy. CXCR2+ myeloid-derived suppressor cells (MDSCs) are abundant in PDAC tumors in humans and in mouse models. MDSCs suppress effector cell function, making them attractive targets for restoring anti-tumor immunity. In this study, we show that the most abundant soluble factors released from a genetically diverse set of human and mouse PDAC cells are CXCR2 ligands, including CXCL8, CXCL5, and CXCL1. Expression of CXCR2 ligands is at least partially dependent on mutant KRAS and NFκB signaling, which are two of the most commonly dysregulated pathways in PDAC. We show that MDSCs are the most prevalent immune cells in PDAC tumors. MDSCs expressed high levels of CXCR2, and we found that myeloid cells readily migrate toward conditioned media (CM) prepared from PDAC cultures. We designed CXCR2 ligand-Fc fusion proteins to modulate the CXCR2 chemotactic signaling axis. Unexpectedly, these fusion proteins were superior to native chemokines in binding and activation of CXCR2 on myeloid cells. These "superkines" were potent inhibitors of PDAC CM-induced myeloid cell migration and were superior to CXCR2 small-molecule inhibitors and neutralizing antibodies. Our findings suggest that CXCR2 superkines may disrupt myeloid cell recruitment to PDAC tumors, ultimately improving immunotherapy outcomes in patients with PDAC.

CAR T cell therapy, as a rapidly advancing immuno-oncology modality, has achieved significant success in the treatment of leukaemia and lymphoma. However, its application in solid tumours remains limited. The challenges include the heterogeneity of tumours, local immunosuppression, poor trafficking and infiltration, life-threatening toxicity and the lack of precise representative immunocompetent research models. Considering its typically dense and immunosuppressive tumour microenvironment (TME) and early metastasis, pancreatic ductal adenocarcinoma (PDAC) was employed as a model to address the challenges that hinder CAR T cell therapies against solid tumours and to expand immunotherapeutic options for advanced disease.

A novel murine A20FMDV2 (A20) CAR T cell targeting integrin αvβ6 (mA20CART) was developed, demonstrating efficient and specific on-target cytotoxicity. The mA20CART cell as a monotherapy for orthotopic pancreatic cancer in an immunocompetent model demonstrated modest efficacy. Therefore, a novel triple therapy regimen, combining mA20CART cells with oncolytic vaccinia virus encoding IL-21 and a TGF-β-blocking antibody was evaluated in vivo.

The triple therapy improved overall survival, improved the safety profile of the CAR T cell therapy, attenuated metastasis and enhanced T cell infiltration. Notably, the potency of mA20CART was dependent on IL-2 supplementation.

This study presents an αvβ6-targeting murine CAR T cell, offering a novel approach to developing CAR T cell technologies for solid tumours and a potential adjuvant therapy for pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) frequently exhibits an immunosuppressive microenvironment coupled with malnutrition status. These features are instrumental in clinical management strategies for PDAC.

Immune-nutrition status of patients was evaluated by integrating systemic immune-inflammatory index (SII) and prognostic nutritional index (PNI). Individuals were divided into SII-PNI Status positive (SPS+) group and SPS negative (SPS-) group. Morphology of tissues was evaluated by hematoxylin-eosin (H&E) staining. Expression of PD-L1 and p53 was detected using immunohistochemistry (IHC).

In this study, 530 eligible patients (mean ± SD age, 60.5 ± 9.17 years, 296 males [55.8%], 74 SPS+ [14.0%]) were included. These patients exhibited a median survival of 24 months (1-, 3- and 5-year survival rate; 72.9%, 34.7% and 25.1%, respectively). In the multivariate analysis, independent indicators for outcomes were identified as tumor size, lymph node metastasis and SPS (all p <.01). After matching and adjusting, patients with SPS+ exhibited a notably reduced overall survival compared to those with SPS- (14 vs. 25 months, p <.001), with hazard ratio (95% CI) of 1.79 (1.25-2.56). IHC revealed markedly elevated positive cell proportion of PD-L1 in SPS+ group (p <.01) and distinct p53 mutation patterns between SPS+ and SPS- groups (p =.03). Morphology demonstrated a dissimilar trend of differentiation levels between the two groups (p =.08).

The findings suggest poorer outcome, higher PD-L1 expression and distinct p53 mutation status of patients with SPS+. These patterns may contribute to PDAC management and strategic deployment of immunotherapy and targeted therapy.

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.

Pancreatic ductal adenocarcinoma (PDAC) is characterized by a dense, fibrotic, immunosuppressive, and desmoplastic extracellular matrix. Mesenchymal stem cell (MSC)-derived extracellular vesicles (EVs) have emerged as a novel therapeutic strategy. Nonetheless, the potential dual effects of MSC-EVs on tumor cells warrant careful consideration. This study aimed to evaluate the mechanistic effects of MSC-EVs on PDAC. Wharton's Jelly (WJ) MSC-derived small EVs were isolated using ultracentrifugation method and analyzed through nanoparticle tracking analysis (NTA) and flow cytometry. EVs were added to Panc-1 cells at concentrations of 4000-10,000 EVs per cell, and a preliminary MTT assay was performed. In subsequent experiments, EVs were added to Panc-1 cells at concentrations of only 4000, 8000 and 12,000 EVs per cell. After 24 h, apoptosis and cell cycle analyses were performed. The expression of epithelial-mesenchymal transition (EMT)-related and immune-related genes was analyzed. Cell cycle analysis showed higher G1 phase percentage in the control group (31%) compared to MSC EV-treated groups (35-36%). Apoptosis analysis revealed similar viable and necrotic cell percentages among the control (80% viable) and treated groups (approximately 78-79% viable). The CD44, VIM, MMP9, TIMP1, and ZEB1 genes were downregulated in treated groups compared to the control. Although CLDN1 and CDH1 genes were upregulated at the lowest EV concentration, they were downregulated at higher EV concentrations. Immune gene analysis showed downregulation of pro-inflammatory cytokines (IL-6, TNF-α, IFN-γ, IL-1α, IL-1β) and upregulation of the anti-inflammatory cytokine IL-10 in treated groups. This study revealed the dual role of WJ-MSC small EVs in PDAC. While they suppressed cell proliferation and modulated EMT markers, indicating their antitumor potential, they also exhibited an immunosuppressive profile. These findings highlight both the promise and challenges of using WJ-MSC small EVs as therapeutic agents, necessitating further studies to optimize their application and balance their effects.

Pancreatic ductal adenocarcinoma (PDAC) is the third leading cause of cancer-related mortality in the United States, with poor overall survival across all stages. Less than 20% of patients are eligible for curative surgical resection at diagnosis, and despite adjuvant chemotherapy, most will experience disease recurrence within two years. The incorporation of immune-based strategies in the adjuvant setting remains an area of intense investigation with unrealized promise. It offers the potential of providing durable disease control for micro-metastatic disease following curative intent surgery and enabling personalized treatments based on mutational neoantigen profiles derived from resected specimens. However, most of these attempts have failed to demonstrate significant clinical success, likely due to the immunosuppressive tumor microenvironment (TME) and individual genetic heterogeneity. Despite these challenges, immune-based strategies, such as therapeutic vaccines targeted towards neoantigens, have demonstrated promise via immune activation and induction of T-cell tumor infiltration. In this review, we will highlight the foundational lessons learned from previous clinical trials of adjuvant immunotherapy, discussing the knowledge gained from analyses of trials with disappointing results. In addition, we will discuss how these data have been incorporated to design new agents and study concepts that are proving to be exciting in more recent trials, such as shared antigen vaccines and combination therapy with immune-checkpoint inhibitors and chemotherapy. This review will evaluate novel approaches in ongoing and future clinical studies and provide insight into how these immune-based strategies might evolve to address the unique challenges for treatment of PDAC in the adjuvant setting.

Due to the highly heterogeneous and immunosuppressed tumor microenvironment (TME), pancreatic adenocarcinoma (PAAD) has limited therapeutic options and an abysmal prognosis. Ephrin A 1-5 (EFNA1-5) have been shown to regulate tumorigenesis and metastasis in various cancers, but its role in PAAD remains unclear.

We comprehensively analyzed EFNA gene expression levels in pan-cancer and PAAD using the GEPIA and HPA databases. Then, we assessed the prognostic value of EFNA1-5 using the Kaplan-Meier plotter and nomogram model. Further exploration of the association of EFNA1-5 with clinicopathological features of PAAD used information from the UALCAN database, and the TIMER dataset was used to reveal the correlation between EFNA1-5 and the tumor immune microenvironment (TIME) of pancreatic cancer. In addition, cBioPortal Databases, GSEA, and GSCALite were used to explore gene changes, protein interactions, and biological functions. Finally, the oncogenic effect of EFNA5 was verified in vivo and in vitro.

The expression levels of EFNA1-5 were significantly upregulated in PAAD. The expression of EFNA1/3/4/5 were significantly associated with overall survival (OS) and relapse-free survival (RFS) in PAAD patients. The high expression of EFNA2-5 were related to poor clinical features, such as higher tumor stage or grade and a wider range of lymph node metastasis. EFNA1-5 were closely associated with immune cell infiltration, CAFs, and MDSCs expression. Furthermore, EFNA5 is an independent risk factor for poor prognosis in PAAD patients, and it can promote the malignant progression of pancreatic cancer in vitro and in vivo.

Differential expression of EFNA1-5 is associated with TIME in pancreatic cancer, predicts different survival outcomes, and maybe a novel prognostic marker reflecting an immunosuppressive state and a potential therapeutic target.

The harsh biological barriers and bacteria within tumor microenvironment not only hinder drug penetration and induce drug inactivation, but also inhibit antitumor immune responses. Here a tumor microenvironment dual cascade-responsive multifunctional nanoparticle, Gem/Emo@NP@GHA is reported, which is engineered from a hyaluronidase (HAase)-responsive guanidine group functionalized hyaluronic acid (GHA) shell and a glutathione (GSH)-responsive biopolymer core (Gem/Emo@NP), that encapsulates anticancer drug gemcitabine (Gem) and two-photon-excited photosensitizer emodin (Emo). The constructed Gem/Emo@NP@GHA can specifically target the tumor and subsequently be degraded by HAase-abundant in the extracellular matrix. Thus, the resulting Gem/Emo@NP achieved size reduction and charge reversal, strengthening deep tumor penetration. Upon internalization, the positively charged Gem/Emo@NP effectively kills intratumor bacteria by inducing membrane depolarization. Furthermore, the high levels of GSH within tumor cells disrupt the disulfide bonds of Gem/Emo@NP, triggering drug release. Thereby, the undecomposed Gem successfully induces tumor cell apoptosis and necrosis. Under laser irradiation, photosensitizer Emo generates high singlet oxygen (1O2), further eliminating tumors and intracellular bacteria. More importantly, Gem/Emo@NP@GHA can activate T cell-mediated immune response, further enhancing antitumor activity. These findings provide a promising approach to treating bacterially infected tumors through the synergistic application of chem-immunotherapy and two-photon-excited photodynamic therapy.

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy with a poor prognosis. Mac2-binding protein glycosylated isomer (M2BPGi), a known biomarker for liver fibrosis, is also elevated in other fibrotic tissues. However, its role in PDAC remains unexplored. This study investigates the potential of M2BPGi as a prognostic biomarker for PDAC and elucidates its role in cancer progression.

We analyzed serum M2BPGi levels in 83 PDAC patients and 60 healthy controls, examining the relationship with clinical outcomes. Tissue immunostaining and in vitro experiments were conducted to investigate M2BPGi-secreting cells and its role.

Serum M2BPGi levels were significantly higher in PDAC patients than in controls (0.98 vs. 0.59, p < 0.0001). Notably, elevated serum M2BPGi was associated with worse progression-free survival (144 days vs. 260 days, p = 0.017) and overall survival (OS) (245 days vs. 541 days, p < 0.001) following chemotherapy. Multivariable Cox regression analysis further confirmed that a high serum M2BPGi level is an independent risk factor for OS (HR: 2.44, 95% CI 1.26-4.74, p = 0.008). Immunostaining revealed that M2BPGi is secreted by both cancer cells and cancer-associated fibroblasts (CAFs), with high M2BP expression in CAFs correlating with poor prognosis. Furthermore, M2BPGi-secreting CAFs exhibited characteristics of inflammatory CAFs. M2BPGi directly activated mTOR signaling and epithelial-mesenchymal transition in PDAC cells, enhancing their invasive and migratory capabilities.

Our findings identify M2BPGi as a promising prognostic biomarker for PDAC. Moreover, we demonstrate that inflammatory CAFs promote tumor invasion and contribute to poor outcomes by secreting M2BPGi, revealing a novel mechanism of PDAC progression.

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.

Pancreatic ductal adenocarcinoma (PDAC) is insidious, with only 15-20% of those diagnosed suitable for surgical resection as it is either too advanced and has invaded local structures or has already spread to distant sites. The associated tumor microenvironment provides a protective shield which limits the efficacy of chemotherapeutic agents, but also impairs the delivery of nutrients required for the PDAC cells. To compensate for this, metabolic adaptions occur to provide alternative sources of fuel. The aim of this study is to explore metabolomic differences between participants with resectable PDAC compared to healthy volunteers (HV). The objectives were to use nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS) to determine if resectable PDAC induces sufficient metabolic adaptations and variations which could be used to discriminate between the two groups.

Plasma samples were collected from fasted individuals with resectable PDAC (n = 23, median age 68 [IQR 56-75], 69.6% male) and HV (n = 24, median age 63 [IQR 58-71], 54.2% male). Samples were analyzed using NMR and the Biocrates MxP Quant 500 kit at University Hospital Southampton.

NMR spectroscopy identified six independent metabolites that significantly discriminated between the PDAC and HV groups, including elevated plasma concentrations of 3-hydroxybutyrate and citrate, with decreased amounts of glutamine and histidine. MS analysis identified 84 metabolites with a significant difference between the PDAC and HV cohorts. The metabolites with a fold change (FC) > 1.5 in the PDAC population were conjugated bile acids (taurocholic acid, glycocholic acid, and glycochenodexoycholic acid).

In conclusion, using metabolomics, biochemical differences between resectable PDAC and HV were detected. These differences indicate metabolic plasticity and utilization of alternative fuel sources.

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers in the world, mainly because of its powerful pro-connective tissue proliferation matrix and immunosuppressive tumor microenvironment (TME), which promote tumor progression and metastasis. In addition, the extracellular matrix leads to vascular collapse, increased interstitial fluid pressure, and obstruction of lymphatic return, thereby hindering effective drug delivery, deep penetration, and immune cell infiltration. Therefore, reshaping the TME to enhance tumor perfusion, increase deep drug penetration, and reverse immune suppression has become a key therapeutic strategy. Traditional therapies for PDAC, including surgery, radiation, and chemotherapy, face significant limitations. Surgery is challenging due to tumor location and growth, while chemotherapy and radiation are hindered by the dense extracellular matrix and immunosuppressive TME. In recent years, the advancement of nanotechnology has provided new opportunities to improve drug efficacy. Nanoscale drug delivery systems (NDDSs) provide several advantages, including improved drug stability in vivo, enhanced tumor penetration, and reduced systemic toxicity. However, the clinical translation of nanotechnology in PDAC therapy faces several challenges. These include the need for precise targeting and control over drug release, potential immune responses to the nanocarriers, and the scalability and cost-effectiveness of production. This article provides an overview of the latest nanobased methods for achieving better therapeutic outcomes and overcoming drug resistance. We pay special attention to TME-targeted therapy in the context of PDAC, discuss the advantages and limitations of current strategies, and emphasize promising new developments. By emphasizing the enormous potential of NDDSs in improving the treatment outcomes of patients with PDAC, while critically discussing the limitations of traditional therapies and the challenges faced by nanotechnology in achieving clinical breakthroughs, our review paves the way for future research in this rapidly developing field.

The dysfunction of natural killer (NK) cells, mediated by transforming growth factor β1 (TGFβ1) within the tumor microenvironment, impedes antitumor therapy and contributes to poor clinical outcomes. Our study introduces self-activating chimeric antigen receptor (CAR)-NK cells that block TGFβ1 signaling by releasing a specifically designed peptide, P6, which targets mesothelin in pancreatic tumors. P6 originates from the interaction sites between TGFβ1 and TGFβ receptor 1 and effectively disrupts TGFβ1's inhibitory signaling in NK cells. Our analysis demonstrates that P6 treatment interrupts the SMAD2/3 pathway in NK cells, mitigating TGFβ1-mediated suppression of NK cell activity, thereby enhancing their metabolic function and cytotoxic response against pancreatic tumors. These CAR-NK cells exhibit potent antitumor capabilities, as evidenced in spheroid cultures with cancer-associated fibroblasts and in vivo mouse models. Our approach marks a substantial advancement in overcoming TGFβ1-mediated immune evasion, offering a promising avenue for revolutionizing cancer immunotherapy.

Background: Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer, able to thrive in a challenging tumor microenvironment. Current standard therapies, including surgery, radiation, chemotherapy, and chemoradiation, have shown a dismal survival prognosis, resulting in less than a year of life in the metastatic setting. Methods: The pressing need to find better therapeutic methods brought about the discovery of new targeted therapies against the infamous KRAS mutations, the major oncological drivers of PDAC. Results: The most common KRAS mutation is KRASG12D, which causes a conformational change in the protein that constitutively activates downstream signaling pathways driving cancer hallmarks. Novel anti-KRASG12D therapies have been developed for solid-organ tumors, including small compounds, pan-RAS inhibitors, protease inhibitors, chimeric T cell receptors, and therapeutic vaccines. Conclusions: This comprehensive review summarizes current knowledge on the biology of KRAS-driven PDAC, the latest therapeutic options that have been experimentally validated, and developments in ongoing clinical trials.

The cancer-associated fibroblasts (CAFs) in tumor stroma present substantial barriers to drug penetration, resulting in tumor resistance and progression. One promising strategy is to reprogram CAFs into a quiescent state, which necessitates novel approaches. Our study introduces a sequential treatment strategy using chitosan thermosensitive hydrogels loaded with α-Mangostin (α-M), a small molecule drug with antifibrotic properties, aimed at reprogramming CAFs within the breast cancer tumor microenvironment (TME). We developed glutathione (GSH)-responsive nanoparticles (NPc) that carry the chemotherapeutic drug doxorubicin (DOX). Treatment with α-M results in the downregulation of CAF-specific biomarkers and a remodeled TME, which improves the penetration of NPc/DOX deep into the tumor tissue. This strategy holds great promise in enhancing cancer therapeutic outcomes in tumors rich in CAFs, particularly in the case of breast cancer.

The mechanisms by which neutrophils acquire pro-tumor properties remain poorly understood. In pancreatic cancer, cancer-associated fibroblasts (CAFs) may interact with neutrophils, directing them to promote tumor progression.

To validate the association between CAFs and neutrophils, the localization of neutrophils was examined in clinically resected pancreatic cancer specimens. CAFs were produced by culturing in cancer-conditioned media, and the effects of these CAFs on neutrophils were examined. In vitro migration and invasion assays assess the effect of CAF-activated neutrophils on cancer cells. The factors secreted by the activated neutrophils were also explored. Finally, pirfenidone (PFD) was tested to determine whether it could suppress the pro-tumor functions of activated neutrophils.

In pancreatic cancer specimens, neutrophils tended to co-localize with IL-6-positive CAFs. Neutrophils co-cultured with CAFs increased migratory capacity and prolonged life span. CAF-affected neutrophils enhance the migratory and invasive activities of pancreatic cancer cells. IL-8 is the most upregulated cytokine secreted by the neutrophils. PFD suppresses IL-8 secretion from CAF-stimulated neutrophils and mitigates the malignant traits of pancreatic cancer cells.

CAFs activate neutrophils and enhance the malignant phenotype of pancreatic cancer. The interactions between cancer cells, CAFs, and neutrophils can be disrupted by PFD, highlighting a potential therapeutic approach.

Pancreatic ductal adenocarcinoma (PDAC) has one of the worst prognoses of all common solid cancers. For the large majority of PDAC patients, only systemic therapies with very limited efficacy are indicated. In addition, immunotherapies have not brought the advances seen in other cancer types. Several key characteristics of PDAC contribute to poor treatment outcomes, and in this review, we will discuss how these characteristics are best captured in currently available ex vivo or in vitro model systems. For instance, PDAC is hallmarked by a highly desmoplastic and immune-suppressed tumor microenvironment that impacts disease progression and therapy resistance. Also, large differences in tumor biology exist between and within tumors, complicating treatment decisions. Furthermore, PDAC has a very high propensity for locally invasive and metastatic growth. The use of animal models is often not desirable or feasible and several in vitro and ex vivo model systems have been developed, such as organotypic cocultures and tissue slices, among others. However, the absence of a full host organism impacts the ability of these models to accurately capture the characteristics that contribute to poor outcomes in PDAC. We will discuss the caveats and advantages of these model systems in the context of PDAC's key characteristics and provide recommendations on model choice and the possibilities for optimization. These considerations should be of use to researchers aiming to study PDAC in the in vitro setting.

Multiple randomized trials have suggested that the addition of comprehensive metastasis-directed therapy to best systemic therapy improves disease control and survival among patients with oligometastatic disease, even for histologies with a high propensity for rapid spread. Here, we review the growing literature supporting the oligometastatic paradigm in pancreatic ductal adenocarcinoma. We summarize key details from nascent institutional series and reflect on the recently reported phase II randomized EXTEND trial. We discuss various strategies for enhancing the clinical and technical implementation of metastasis-directed therapy in this patient population. Lastly, we highlight multiple ongoing landmark trials seeking to optimize and validate the role of metastasis-directed therapy in oligometastatic pancreatic cancer. Ultimately, these and other continued clinical and translational research efforts will be critical to improve care and outcomes for patients with oligometastatic pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is characterized by aggressive growth and metastasis, partly driven by fibroblast-mediated stromal interactions. Using RNA sequencing of fibroblasts from early-stage KPC mouse models, we identified significant upregulation of genes involved in adipogenesis, fatty acid metabolism, and the ROS pathway. ANGPTL4, a key adipogenesis regulator, was highly expressed in fibroblasts and promoted pancreatic cancer cell proliferation and migration through paracrine signaling. Notably, cancer cell-driven paracrine signals appear to regulate ANGPTL4 expression in fibroblasts, suggesting that ANGPTL4 may act as a reciprocal factor in a feedback loop that enhances tumor progression. LAMA2, an extracellular matrix gene with reduced expression, suppressed pancreatic cancer cell migration, proliferation, and invasion. This study provides the temporal transcriptional analysis of fibroblast subtypes during early PDAC, highlighting the roles of metabolic reprogramming and ECM remodeling in shaping the tumor microenvironment and identifying potential therapeutic targets.

We previously examined the antitumor effects of short interfering RNA nanoparticles targeting mammalian target of rapamycin (mTOR) in an orthotopic pancreatic cancer mouse model. We herein report the inhibitory effects of the mTOR inhibitor rapamycin on tumor growth in a novel established mouse model of pancreatic cancer using human pancreatic cancer cell line-derived organoids. Gemcitabine, 5-fluorouracil, and gemcitabine plus nab-paclitaxel are clinically used to treat advanced pancreatic cancer. In vitro assays showed that rapamycin strongly inhibited cell invasion, while gemcitabine, 5-fluorouracil, and gemcitabine plus paclitaxel primarily inhibited cell proliferation with minimal effects on invasion. In vivo mouse experiments demonstrated that rapamycin exhibited superior antitumor activity to S-1 (a metabolically activated prodrug of 5-fluorouracil) and another mTOR inhibitor, everolimus, while its efficacy was similar to that of gemcitabine plus paclitaxel (which was used instead of nab-paclitaxel due to concerns about allergic reactions in mice to human albumin) in a mouse model of pancreatic cancer using human pancreatic cancer cell line-derived organoids. Furthermore, the combination of rapamycin with gemcitabine plus paclitaxel exerted synergistic inhibitory effects on the growth of pancreatic cancer tumors. Although the inhibition of tumor growth was significantly stronger in everolimus-treated mice than in control mice, there were no additive anti-growth effects when combined with gemcitabine plus paclitaxel. The present results suggest that the combination of rapamycin with gemcitabine plus paclitaxel achieved the greatest reduction in tumor volumes in the mouse xenograft model and, thus, has significant clinical promise.

Digestive system neoplasms are highly heterogeneous and exhibit complex resistance mechanisms that render anti-programmed cell death protein (PD) therapies poorly effective. The tumor microenvironment (TME) plays a pivotal role in tumor development, apart from supplying energy for tumor proliferation and impeding the body's anti-tumor immune response, the TME actively facilitates tumor progression and immune escape via diverse pathways, which include the modulation of heritable gene expression alterations and the intricate interplay with the gut microbiota. In this review, we aim to elucidate the mechanisms underlying drug resistance in digestive tumors, focusing on immune-mediated resistance, microbial crosstalk, metabolism, and epigenetics. We will highlight the unique characteristics of each digestive tumor and emphasize the significance of the tumor immune microenvironment (TIME). Furthermore, we will discuss the current therapeutic strategies that hold promise for combination with cancer immune normalization therapies. This review aims to provide a thorough understanding of the resistance mechanisms in digestive tumors and offer insights into potential therapeutic interventions.

Patient-derived organoids (PDOs) and xenografts (PDXs) are powerful tools for personalized medicine in pancreatic cancer (PC) research. This study explores the complementary strengths of PDOs and PDXs in terms of practicality, genetic fidelity, cost, and labor considerations. Among other models like 2D cell cultures, spheroids, cancer-on-chip systems, cell line-derived xenografts (CDX), and genetically engineered mouse models (GEMMs), PDOs and PDXs uniquely balance genetic fidelity and personalized medicine potential, offering distinct advantages over the simplicity of 2D cultures and the advanced, but often resource-intensive, GEMMs and cancer-on-chip systems. PDOs excel in high-throughput drug screening due to their ease of use, lower cost, and shorter experimental timelines. However, they lack a complete tumor microenvironment. Conversely, PDXs offer a more complex microenvironment that closely reflects patient tumors, potentially leading to more clinically relevant results. Despite limitations in size, number of specimens, and engraftment success, PDXs demonstrate significant concordance with patient responses to treatment, highlighting their value in personalized medicine. Both models exhibit significant genetic fidelity, making them suitable for drug sensitivity testing. The choice between PDOs and PDXs depends on the research focus, resource availability, and desired level of microenvironment complexity. PDOs are advantageous for high-throughput screening of a diverse array of potential therapeutic agents due to their relative ease of culture and scalability. PDXs, on the other hand, offer a more physiologically relevant model, allowing for a comprehensive evaluation of drug efficacy and mechanisms of action.

Controlled photooxidation-mediated disruption of collagens in the tumor microenvironment can reduce desmoplasia and enhance immune responsiveness. However, achieving effective light delivery to solid tumors, particularly those with dynamic volumetric changes like pancreatic ductal adenocarcinoma (PDAC), remains challenging and limits the repeated and sustained photoactivation of drugs. Here, 3D, shape-morphing, implantable photonic devices (IPDs) are introduced that enable tumor-specific and continuous light irradiation for effective metronomic photodynamic therapy (mPDT). This IPD adheres seamlessly to the surface of orthotopic PDAC tumors, mitigating issues related to mechanical mismatch, delamination, and internal lesions. In freely moving mouse models, mPDT using the IPD with close adhesion significantly reduces desmoplastic tumor volume without causing cytotoxic effects in healthy tissues. These promising in vivo results underscore the potential of an adaptable and unidirectional IPD design in precisely targeting cancerous organs, suggesting a meaningful advance in light-based therapeutic technologies.

Waldenstrom macroglobulinemia (WM) is a non-Hodgkin B-cell lymphoma, characterized by bone marrow infiltration with plasma cells and lymphocytes. The tumor microenvironment (TME) plays an important role in mediating WM cell biology, but the effects of macrophages on WM biology remains unclear. Here, we investigated the effects of macrophages on WM growth and survival and identified a novel role for transcription factor GLI3 in macrophage polarization. We found that co-culture of M0 and M2 macrophages promoted WM cell growth and survival, and co-culture WM cells with M0 macrophages induced M2-like phenotypes. Interestingly, GLI3 expression was induced in M2 macrophages (not M1), leading us to perform analysis of macrophages from mice lacking Gli3 in myeloid cells (M-Gli3-/- mice). A subset of differentially expressed genes implicated a role for GLI3 in macrophage polarization. Macrophages from M-Gli3-/- mice did not induce WM cell proliferation and reduced survival compared to M2 macrophages from WT mice. In addition, in vitro polarization of M0 macrophages from M-Gli3-/- was not able to induce M2 markers such as CD163, despite inducing iNos expression (M1 marker). Taken together, these results suggest a role for M2 macrophages in promoting WM cell growth and identify GLI3 as a modulator of macrophage polarization.

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive and lethal malignancy characterized by dysregulated energy and stromal metabolism. It is strongly supported by activated pancreatic stellate cells (PSC) which drive excessive desmoplasia and tumor growth via metabolic crosstalk. Herein, a programmed nanosystem is designed to dual rectify the metabolism abnormalities of the PDAC cells, which overexpress glucose transporter 1(GLUT1) and CD71, and the PSC for oncotherapy. The nanosystem is based on a tumor microenvironment-responsive liposome encapsulating an NF-κB inhibitor (TPCA-1) and a CD71 aptamer-linked Glut1 siRNA. TPCA-1 reverses the activated PSC to quiescence, which hampers metabolic support of the PSC to PDAC cells and bolsters the PDAC cell-targeting delivery of the siRNA. Aerobic glycolysis and the following enhancement of oxidative phosphorylation are restrained by the nano-modulation so as to amplify anti-PDAC efficacy in an orthotopic xenograft mouse model, which implies more personalized PDAC treatment based on different energy metabolic profiles.

Pancreatic ductal adenocarcinoma (PDAC) is an increasingly diagnosed cancer that kills 90% of afflicted patients, with most patients receiving palliative chemotherapy. We identified neuronal pentraxin 1 (NPTX1) as a cancer-secreted protein that becomes overexpressed in human and murine PDAC cells during metastatic progression and identified adhesion molecule with Ig-like domain 2 (AMIGO2) as its receptor. Molecular, genetic, biochemical, and pharmacologic experiments revealed that secreted NPTX1 acts cell-autonomously on the AMIGO2 receptor to drive PDAC metastatic colonization of the liver-the primary site of PDAC metastasis. NPTX1-AMIGO2 signaling enhanced hypoxic growth and was critically required for hypoxia-inducible factor-1α (HIF1α) nuclear retention and function. NPTX1 is overexpressed in human PDAC tumors and upregulated in liver metastases. Therapeutic targeting of NPTX1 with a high-affinity monoclonal antibody substantially reduced PDAC liver metastatic colonization. We thus identify NPTX1-AMIGO2 as druggable critical upstream regulators of the HIF1α hypoxic response in PDAC. Significance: We identified the NPTX1-AMIGO2 axis as a regulatory mechanism upstream of HIF1α-driven hypoxia response that promotes PDAC liver metastasis. Therapeutic NPTX1 targeting outperformed a common chemotherapy regimen in inhibiting liver metastasis and suppressed primary tumor growth in preclinical models, revealing a novel therapeutic strategy targeting hypoxic response in PDAC.

Pancreatic adenocarcinoma (PDAC) is the predominant form of pancreatic cancer and one of the leading causes of cancer-related death worldwide, with an extremely poor prognosis after diagnosis. High mortality from PDAC arises partly due to late diagnosis resulting from a lack of early-stage biomarkers and due to chemotherapeutic drug resistance, which arises from a highly fibrotic stromal response known as desmoplasia. Desmoplasia alters tissue mechanics, which triggers changes in cell mechanosensing and leads to dysregulated transcriptional activity and disease phenotypes. Hydrogels are effective in vitro models to mimic mechanical changes in tissue mechanics during PDAC progression and to study the influence of these changes on mechanosensitive cell responses. Despite the complex biophysical changes that occur within the PDAC microenvironment, carefully designed hydrogels can very closely recapitulate these properties during PDAC progression. Hydrogels are relatively inexpensive, highly reproducible and can be designed in a humanised manner to increase their relevance for human PDAC studies. In vivo models have some limitations, including species-species differences, high variability, expense and legal/ethical considerations, which make hydrogel models a promising alternative. Here, we comprehensively review recent advancements in hydrogel bioengineering for developing our fundamental understanding of mechanobiology in PDAC, which is critical for informing advanced therapeutics.

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.