Immunological combination treatment holds the key to improving survival in pancreatic cancer

Biodegradable polyester-based hyperbranched nanocarrier-modified with N-acetyl glucosamine for efficient drug delivery to cancer cells through GLUTs

Cancer, ranking just below cardiovascular diseases, is a leading cause of mortality worldwide. The key to enhancing survival rates among cancer patients lies in the early detection, removal, and treatment of tumors. However, the broad-spectrum nature of current treatments, including chemotherapy and radiation therapy, results in significant collateral damage to healthy cells and tissues. In this context, hyperbranched polymers present a promising avenue for more targeted therapy. These polymers can be loaded with chemotherapeutic drugs and modified with specific ligands to selectively target cancer cells via glucose transporters, which are overexpressed in many cancer types. To enhance the delivery of drugs to cancer cells, we have engineered an N-acetyl glucosamine conjugated version of this polymer. The characterization of these nanocarriers was evaluated using various techniques, including 1H NMR, dynamic light scattering, and FTIR spectroscopy. Additionally, confocal microscopy was utilized to compare the accumulation of doxorubicin in cancer cells using both the N-acetyl glucosamine-conjugated and unmodified versions of H40 Boltorn™. Our observations indicated a superior accumulation of doxorubicin in cells treated with the modified H40 polymer. Further evaluation of the drug-loaded nanocarriers was conducted on MDA-MB-231 and 4T1 breast cancer cell lines, focusing on their cytotoxic effects. This suggests that the targeted delivery of anticancer drugs using the modified H40 Boltorn™ nanocarriers significantly enhances the ability to kill breast cancer cells, offering a more efficient and selective approach to chemotherapy that minimizes impact on healthy tissues and cells.

Endoscopic Ultrasound-Guided Radiofrequency Ablation for Pancreatic Adenocarcinoma: A Scoping Review with Meta-Analysis

Background: Endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) has recently been proposed as an alternative treatment option for patients with unresectable pancreatic adenocarcinoma (uPDAC) or metastatic pancreatic adenocarcinoma (mPDAC). This review aims to evaluate the technical feasibility, safety, and clinical outcomes of EUS-RFA in treating PDAC, based on the available literature. Methods: Following the PRISMA-DTA guidelines, a comprehensive search of databases, including PubMed, Scopus, and the Cochrane Library, was conducted, focusing on studies reporting on EUS-RFA for PDAC. Articles involving human subjects diagnosed with PDAC and treated with EUS-RFA, written in English, and published up to 30 June 2024, were included. Key outcome measures such as technical success rate, adverse events, tumor response, and patient survival were extracted and analyzed. The review process involved title and abstract screening, followed by full-text review. A meta-analysis was performed for adverse event rates using a random-effects model. Results: We identified 11 studies according to our inclusion criteria, with a total of 137 patients with PDAC. Except for the initial experience with a lower technical success rate due to tumor-related stiffness, all subsequent studies reported a pooled success rate of 100%. Most studies referred to locally advanced or metastatic PDAC, while one reported EUS-RFA in resectable PDAC. A meta-analysis for adverse events was performed, indicating a pooled adverse event rate of 22.6% (95% confidence interval: 0.16-0.30), with the most common adverse event being mild abdominal pain. Severe complications were rare. One study reported a median progression-free survival (PFS) of 16.3 months. Overall survival and PFS were scarcely reported, with median overall survival ranging from 12 to 24 months, inferior to that of the standard approach for uPDAC consisting of neoadjuvant chemoradiotherapy followed by surgery. Conclusions: EUS-RFA is a technically feasible and safe procedure for treating uPDAC or mPDAC and is under investigation for use in resectable PDAC. Even though the short-term outcomes are encouraging, larger cohort studies are necessary to understand long-term efficacy and survival benefits, including progression-free survival.

Local ablation disrupts immune evasion in pancreatic cancer

BACKGROUND

Pancreatic cancer (PC) is characterised by late diagnosis, tumour heterogeneity, and a peculiar immunosuppressive microenvironment, leading to poor clinical outcomes. Local ablative techniques have been proposed to treat unresectable PC patients, although their impact on activating the host immune system and overcoming resistance to immunotherapy remains elusive.

METHODS

We dissected the immune-modulatory abilities triggered by local ablation in mouse and human PC models and human specimens, integrating phenotypic and molecular technologies with functional assays.

RESULTS

Local ablation treatment performed in mice bearing orthotopic syngeneic PC tumours triggered tumour necrosis and a short-term inflammatory process characterised by the prompt increase of HMGB1 plasma levels, coupled with an enhanced amount of circulating and tumour infiltrating myeloid cells and increased MHCII expression in splenic myeloid antigen-presenting cells. Local ablation synergised with immunotherapy to restrict tumour progression and improved the survival of PC-bearing mice by evoking a T lymphocyte-dependent anti-tumour immune response. By integrating spatial transcriptomics with histological techniques, we pinpointed how combination therapy could reshape TME towards an anti-tumour milieu characterised by the preferential entrance and colocalization of activated T lymphocytes and myeloid cells endowed with antigen presentation features instead of T regulatory lymphocytes and CD206-expressing tumour-associated macrophages. In addition, treatment-dependent TME repolarization extended to neoplastic cells, promoting a shift from squamous to a more differentiated classical phenotype. Finally, we validated the immune regulatory properties induced by local ablation in PC patients and identified an association of the short-term treatment-dependent increase of neutrophils, NLR and HMGB1 with a longer time to progression.

CONCLUSION

Therefore, local ablation might overcome the current limitations of immunotherapy in PC.

Modeling tumor dynamics and predicting response to chemo-, targeted-, and immune-therapies in a murine model of pancreatic cancer

We seek to establish a parsimonious mathematical framework for understanding the interaction and dynamics of the response of pancreatic cancer to the NGC triple chemotherapy regimen (mNab-paclitaxel, gemcitabine, and cisplatin), stromal-targeting drugs (calcipotriol and losartan), and an immune checkpoint inhibitor (anti-PD-L1). We developed a set of ordinary differential equations describing changes in tumor size (growth and regression) under the influence of five cocktails of treatments. Model calibration relies on three tumor volume measurements obtained over a 14-day period in a genetically engineered pancreatic cancer model (KrasLSLG12D-Trp53LSLR172H-Pdx1-Cre). Our model reproduces tumor growth in the control and treatment scenarios with an average concordance correlation coefficient (CCC) of 0.99±0.01. We conduct leave-one-out predictions (average CCC=0.74±0.06), mouse-specific predictions (average CCC=0.75±0.02), and hybrid, group-informed, mouse-specific predictions (average CCC=0.85±0.04). The developed mathematical model demonstrates high accuracy in fitting the experimental tumor data and a robust ability to predict tumor response to treatment. This approach has important implications for optimizing combination NGC treatment strategies.

Tissue-resident natural killer cells support survival in pancreatic cancer through promotion of cDC1-CD8 T activity

The immunosuppressive microenvironment in pancreatic ductal adenocarcinoma (PDAC) prevents tumor control and strategies to restore anti-cancer immunity (i.e. by increasing CD8 T-cell activity) have had limited success. Here, we demonstrate how inducing localized physical damage using ionizing radiation (IR) unmasks the benefit of immunotherapy by increasing tissue-resident natural killer (trNK) cells that support CD8 T activity. Our data confirms that targeting mouse orthotopic PDAC tumors with IR together with CCR5 inhibition and PD1 blockade reduces E-cadherin positive tumor cells by recruiting a hypoactive NKG2D-ve NK population, phenotypically reminiscent of trNK cells, that supports CD8 T-cell involvement. We show an equivalent population in human single-cell RNA sequencing (scRNA-seq) PDAC cohorts that represents immunomodulatory trNK cells that could similarly support CD8 T-cell levels in a cDC1-dependent manner. Importantly, a trNK signature associates with survival in PDAC and other solid malignancies revealing a potential beneficial role for trNK in improving adaptive anti-tumor responses and supporting CCR5 inhibitor (CCR5i)/αPD1 and IR-induced damage as a novel therapeutic approach.

Combination, Modulation and Interplay of Modern Radiotherapy with the Tumor Microenvironment and Targeted Therapies in Pancreatic Cancer: Which Candidates to Boost Radiotherapy?

Pancreatic ductal adenocarcinoma cancer (PDAC) is a highly diverse disease with low tumor immunogenicity. PDAC is also one of the deadliest solid tumor and will remain a common cause of cancer death in the future. Treatment options are limited, and tumors frequently develop resistance to current treatment modalities. Since PDAC patients do not respond well to immune checkpoint inhibitors (ICIs), novel methods for overcoming resistance are being explored. Compared to other solid tumors, the PDAC's tumor microenvironment (TME) is unique and complex and prevents systemic agents from effectively penetrating and killing tumor cells. Radiotherapy (RT) has the potential to modulate the TME (e.g., by exposing tumor-specific antigens, recruiting, and infiltrating immune cells) and, therefore, enhance the effectiveness of targeted systemic therapies. Interestingly, combining ICI with RT and/or chemotherapy has yielded promising preclinical results which were not successful when translated into clinical trials. In this context, current standards of care need to be challenged and transformed with modern treatment techniques and novel therapeutic combinations. One way to reconcile these findings is to abandon the concept that the TME is a well-compartmented population with spatial, temporal, physical, and chemical elements acting independently. This review will focus on the most interesting advancements of RT and describe the main components of the TME and their known modulation after RT in PDAC. Furthermore, we will provide a summary of current clinical data for combinations of RT/targeted therapy (tRT) and give an overview of the most promising future directions.

IFNα and 5-Aza-2'-deoxycytidine combined with a dendritic-cell targeting DNA vaccine alter tumor immune cell infiltration in the B16F10 melanoma model

Introduction

DNA vaccines containing a fusion of the gene encoding chemokine MIP-3α (CCL20), the ligand for CCR6 on immature dendritic cells (DCs), to melanoma-associated antigen genes have enhanced anti-tumor immunity and efficacy compared to those lacking the chemokine gene. Previous work has shown that type-I interferon (IFNα or IFN) and 5-Aza-2'-deoxycytidine (5Aza) significantly enhance the therapeutic benefit of DNA vaccines as measured by reduced tumor burden and improved mouse survival.

Methods

Here, we explored mouse intratumoral immune correlates underlying the therapeutic benefit of this combination regimen (vaccine, IFN, and 5Aza) as compared to vaccine alone and IFN and 5Aza without vaccine, focusing on chemokine mRNA expression by qRT-PCR and inflammatory cellular infiltration into the tumor microenvironment (TME) by flow cytometry and immunohistochemistry (IHC).

Results

The combination group significantly upregulated intratumoral mRNA expression of key immune infiltration chemokines XCL1 and CXCL10. Flow cytometric analyses of tumor suspensions exhibited greater tumor infiltration of CD8+ DCs, CCR7+ DCs, and NK cells in the combination group, as well as reduced levels of myeloid-derived suppressor cells (MDSCs) in vaccinated groups. The mice receiving combination therapy also had greater proportions of effector/memory T-cells (Tem), in addition to showing an enhanced infiltration of Tem and central memory CD8+ T-cells, (Tcm). Tem and Tcm populations both correlated with smaller tumor size. Immunohistochemical analysis of tumors confirmed that CD8+ cells were more abundant overall and especially in the tumor parenchyma with combination therapy.

Discussion

Efficient targeting of antigen to immature DCs with a chemokine-fusion vaccine offers a potential alternative approach to classic and dendritic cell-based vaccines. Combining this approach with IFNα and 5Aza treatments significantly improved vaccine efficacy. This treatment creates an environment of increased inflammatory chemokines that facilitates the trafficking of CD8+ DCs, NK cells, and CD8+ T-cells, especially memory cells, while reducing the number of MDSCs. Importantly, in the combination group, CD8+ cells were more able to penetrate the tumor mass in addition to being more numerous. Further analysis of the pathways engaged by our combination therapy is expected to provide additional insights into melanoma pathogenesis and facilitate the development of novel treatment strategies.

Rational Nanomedicine Design Enhances Clinically Physical Treatment-Inspired or Combined Immunotherapy

Independent of tumor type and non-invasive or minimally-invasive feature, current physical treatments including ultrasound therapy, microwave ablation (MWA), and radiofrequency ablation (RFA) are widely used as the local treatment methods in clinics for directly killing tumors and activating systematic immune responses. However, the activated immune responses are inadequate and incompetent for tumor recession, and the incomplete thermal ablation even aggravates the immunosuppressive tumor microenvironment (ITM), resulting in the intractable tumor recurrence and metastasis. Intriguingly, nanomedicine provides a powerful platform as they can elevate energy utilization efficiency and augment oncolytic effects for mitigating ITM and potentiating the systematic immune responses. Especially after combining with clinical immunotherapy, the anti-tumor killing effect by activating or enhancing the human anti-tumor immune system is reached, enabling the effective prevention against tumor recurrence and metastasis. This review systematically introduces the cutting-edge progress and direction of nanobiotechnologies and their corresponding nanomaterials. Moreover, the enhanced physical treatment efficiency against tumor progression, relapse, and metastasis via activating or potentiating the autologous immunity or combining with exogenous immunotherapeutic agents is exemplified, and their rationales are analyzed. This review offers general guidance or directions to enhance clinical physical treatment from the perspectives of immunity activation or magnification.

Pancreatic ductal adenocarcinoma: Emerging therapeutic strategies

The seventh leading cause of cancer-related death globally, pancreatic ductal adenocarcinoma (PDAC) involves the exocrine pancreas and constitutes greater than 90% of all pancreatic cancers. Surgical resection in combination with systemic chemotherapy with or without radiation remains the mainstay of treatment and the only potentially curative treatment option. While there has been improvement in systemic chemotherapy, long-term survival among patients with PDAC remains poor. Improvement in the understanding of tumorigenesis, genetic mutations, the tumor microenvironment (TME), immunotherapies, as well as targeted therapies continued to drive advances in PDAC treatment. We herein review the TME, genetic landscape, as well as various metabolic pathways associated with PDAC tumorigenesis relative to emerging therapies.

Comprehensive Integrated Single-Cell Whole Transcriptome Analysis Revealed the p-EMT Tumor Cells-CAFs Communication in Oral Squamous Cell Carcinoma

Cancer-associated fibroblasts (CAFs) and partial epithelial–mesenchymal transition (p-EMT) tumor cells are closed together and contribute to the tumor progression of oral squamous cell carcinoma (OSCC). In the present study, we deeply analyzed and integrated OSCC single-cell RNA sequencing datasets to define OSCC CAFs and p-EMT subpopulations. We highlighted the cell–cell interaction network of CAFs and p-EMT tumor cells and suggested biomarkers for the diagnosis and prognosis of OSCC during the metastasis condition. The analysis discovered four subtypes of CAFs: one p-EMT tumor cell population, and cycling tumor cells as well as TNFSF12-TNFRSF25/TNFRSF12A interactions between CAFs and p-EMT tumor cells during tumor metastasis. This suggests the prediction of therapeutically targetable checkpoint receptor–ligand interactions between CAFs and p-EMT tumor cells in OSCC regarding the metastasis status.

Directing hypoxic tumor microenvironment and HIF to illuminate cancer immunotherapy's existing prospects and challenges in drug targets

Cancer is now also reflected as a disease of the tumor microenvironment, primarily supposed to be a decontrolled genetic and cellular expression disease. Over the past two decades, significant and rapid progress has been made in recognizing the dynamics of the tumor's microenvironment and its contribution to influencing the response to various anti-cancer therapies and drugs. Modulations in the tumor microenvironment and immune checkpoint blockade are interesting in cancer immunotherapy and drug targets. Simultaneously, the immunotherapeutic strategy can be done by modulating the immune regulatory pathway; however, the tumor microenvironment plays an essential role in suppressing the antitumor's immunity by its substantial heterogeneity. Hypoxia inducible factor (HIF) is a significant contributor to solid tumor heterogeneity and a key stressor in the tumor microenvironment to drive adaptations to prevent immune surveillance. Checkpoint inhibitors here halt the ability of cancer cells to stop the immune system from activating, and in turn, amplify your body's immune system to help destroy cancer cells. Common checkpoints that these inhibitors affect are the PD-1/PD-L1 and CTLA-4 pathways and important drugs involved are Ipilimumab and Nivolumab, mainly along with other drugs in this group. Targeting the hypoxic tumor microenvironment may provide a novel immunotherapy strategy, break down traditional cancer therapy resistance, and build the framework for personalized precision medicine and cancer drug targets. We hope that this knowledge can provide insight into the therapeutic potential of targeting Hypoxia and help to develop novel combination approaches of cancer drugs to increase the effectiveness of existing cancer therapies, including immunotherapy.

Modulation of the Human Pancreatic Ductal Adenocarcinoma Immune Microenvironment by Stereotactic Body Radiotherapy

PURPOSE

Stereotactic body radiotherapy (SBRT) is an emerging treatment modality for pancreatic ductal adenocarcinoma (PDAC), which can effectively prime cytotoxic T cells by inducing immunogenic tumor cell death in preclinical models. SBRT effects on human PDAC have yet to be thoroughly investigated; therefore, this study aimed to characterize immunomodulation in the human PDAC tumor microenvironment following therapy.

EXPERIMENTAL DESIGN

Tumor samples were obtained from patients with resectable PDAC. Radiotherapy was delivered a median of 7 days prior to surgical resection, and sections were analyzed by multiplex IHC (mIHC), RNA sequencing, and T-cell receptor sequencing (TCR-seq).

RESULTS

Analysis of SBRT-treated tumor tissue indicated reduced tumor cell density and increased immunogenic cell death relative to untreated controls. Radiotherapy promoted collagen deposition; however, vasculature was unaffected and spatial analyses lacked evidence of T-cell sequestration. Conversely, SBRT resulted in fewer tertiary lymphoid structures and failed to lessen or reprogram abundant immune suppressor populations. Higher percentages of PD-1⁺ T cells were observed following SBRT, and a subset of tumors displayed more clonal T-cell repertoires.

CONCLUSIONS

These findings suggest that SBRT augmentation of antitumor immunogenicity may be dampened by an overabundance of refractory immunosuppressive populations, and support the continued development of SBRT/immunotherapy combination for human PDAC.

Tumor Mutational Burden as a Potential Biomarker for Immunotherapy in Pancreatic Cancer: Systematic Review and Still-Open Questions

Tumor mutational burden (TMB) is a numeric index that expresses the number of mutations per megabase (muts/Mb) harbored by tumor cells in a neoplasm. TMB can be determined using different approaches based on next-generation sequencing. In the case of high values, it indicates a potential response to immunotherapy. In this systematic review, we assessed the potential predictive role of high-TMB in pancreatic ductal adenocarcinoma (PDAC), as well as the histo-molecular features of high-TMB PDAC. High-TMB appeared as a rare but not-negligible molecular feature in PDAC, being present in about 1.1% of cases. This genetic condition was closely associated with mucinous/colloid and medullary histology (p < 0.01). PDAC with high-TMB frequently harbored other actionable alterations, with microsatellite instability/defective mismatch repair as the most common. Immunotherapy has shown promising results in high-TMB PDAC, but the sample size of high-TMB PDAC treated so far is quite small. This study highlights interesting peculiarities of PDAC harboring high-TMB and may represent a reliable starting point for the assessment of TMB in the clinical management of patients affected by pancreatic cancer.

Locally Advanced Pancreatic Cancer: Percutaneous Management Using Ablation, Brachytherapy, Intra-arterial Chemotherapy, and Intra-tumoral Immunotherapy

PURPOSE OF REVIEW

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive neoplasms, bearing a terrible prognosis. Stage III tumors, also known as locally advanced pancreatic cancer (LAPC), are unresectable, and current palliative chemotherapy regimens have only modestly improved survival in these patients. At this stage of disease, interventional techniques may be of value and further prolong life. The aim of this review was to explore current literature on locoregional percutaneous management for LAPC.

RECENT FINDINGS

Locoregional percutaneous interventional techniques such as ablation, brachytherapy, and intra-arterial chemotherapy possess cytoreductive abilities and have the potential to increase survival. In addition, recent research demonstrates the immunomodulatory capacities of these treatments. This immune response may be leveraged by combining the interventional techniques with intra-tumoral immunotherapy, possibly creating a durable anti-tumor effect. This multimodality treatment approach is currently being examined in several ongoing clinical trials. The use of certain interventional techniques appears to improve survival in LAPC patients and may work synergistically when combined with immunotherapy. However, definitive conclusions can only be made when large prospective (randomized controlled) trials confirm these results.

The Tumor Microenvironment of Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) has a dismal prognosis along with rising incidence rates and will be responsible for many cancer deaths in the future [...].

The role of plant-derived natural substances as immunomodulatory agents in carcinogenesis

The role of immune system in carcinogenesis represents fundamental events associated with cancer eradication; however, tumor evolution is connected with various mechanisms of tumor evasion and progression of cancer. Based on recent evidence, phytochemicals are directly associated with immunomodulation of the innate and adaptive immunity via different mechanisms of action including stimulation and amplification of immune cells, humoral compartments, and associated molecules. This comprehensive study focuses on immunomodulating potential of phytochemicals (mixture in plants or separately such as individual phytochemical) and their impact on regulation of immune response during cancer development, immune tolerance, and immune escape. Clinical application of phytochemicals as modulators of host immunity against cancer may represent perspective approach in anticancer therapy.