Pancreatic Ductal Adenocarcinoma Therapy Research Articles

Abstract C090: Elucidation of misp53-driven subtype specification and functions in pancreatic cancer

Abstract This study examines how mutations in the TP53 gene, specifically gain-of-function (GOF) mutations, impact the subtyping and stratification of pancreatic ductal adenocarcinoma (PDAC). In addition, it investigates the underlying mechanisms as well as the potential therapeutic implications.TP53 mutations/deletions are present in 60-75 % of cases in PDAC. The most common mutations are three specific hotspot missense mutations (misp53) found at codons R273H, R248W, and R175H. Several studies indicate that these misp53 mutants, despite losing their tumor suppressive function, acquire new oncogenic effects promoting disease aggressiveness and resistance to conventional therapies. Recent findings show that misp53 mutants are associated with a poorly differentiated metastatic subtype in PDAC. However, it is unclear how distinct misp53 mutants, such as misp53R273H, affect PDAC progression and therapy resistance and whether different mutants exert distinct functions. In this study, we explore misp53R273H- and misp53R248W-driven subtype-specificity and functions in PDAC aggressiveness by exploiting transcriptomics, genomic binding and regulation, controlled functional pathways and potential therapeutic targets. By combining cell line-based RNA- and ChIP-seq data we report that misp53R273H associates with and fuels basal-like (BL) neoplastic features by a potential regulation of cell cycle progression. Preclinical mouse models underpinned these findings by connecting misp53R273H tumors to metastatic spread. Generation of constitutive knockdown cell lines and corresponding overexpression assays could support these findings by bridging a loss of misp53R273H to the more favorable classical subtype properties. Of note, co-immunoprecipitation coupled to mass spectrometry analysis revealed misp53-specific and common hotspot mutant interaction partners: for instance, proteins of the group of chromatin remodelers or the ubiquitination pathway that could serve as a mechanistic foundation for misp53-specific functional outcomes. Further, implementation of a large-scale drug screen, flow cytometry and protein expression analyses revealed insights in the potential misp53-specific regulated pathways and therapeutic vulnerabilities, which strongly correlate to cell cycle progression and thus to the previous results. Integrating these findings with preclinical mouse studies, patient-derived xenograft cell lines and publicly available patient data sets strengthens the reported results and highlights their translational relevance. In conclusion, this study clearly demonstrates that hotspot misp53 mutants play a critical role in influencing PDAC subtype-specification and disease aggressiveness. In particular, misp53R273H was associated with BL aggressiveness and cell cycle progression. The ultimate aim of the study is to identify misp53 mutant-specific patient stratification to broaden individualized therapy options. Citation Format: Laura Urbach, Lena Wieland, Frederike Penz, Lukas Klein, Jennifer Appelhans, Christof Lenz, Carolin Schneider, Schneider Günter, Ramona Schulz-Heddergott, Volker Ellenrieder, Elisabeth Heßmann, Shiv K. Singh. Elucidation of misp53-driven subtype specification and functions in pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr C090.

NDRG1 overcomes resistance to immunotherapy of pancreatic ductal adenocarcinoma through inhibiting ATG9A-dependent degradation of MHC-1

AimsPancreatic ductal adenocarcinoma (PDAC) is a deadly disease that is resistant to immune checkpoint blockade (ICB) therapies. Emerging evidence suggests that NDRG1 may be an important target for the development of new therapies for PDAC. Herein, we investigated the novel roles of NDRG1 and Combretastatin A-4 (CA-4) in the treatment of PDAC ICB resistance. MethodsEnrichment of MHC class I was detected by RNA sequence and verified by RT-qPCR and immunoblotting in NDRG1-knockdown human pancreatic cancer cell lines. The protein degradation mode was found by stimulation with various inhibitors, and the autophagy degradation pathway was found by immunoprecipitation and immunolocalization. The roles of NDRG1 and MHC-I in immunotherapy were investigated by orthotopic solid tumors, histology, immunohistochemistry, multiplex immunofluorescence staining and flow cytometry. ResultsHere, we identified a previously undescribed role of NDRG1 in activating major histocompatibility complex class 1 (MHC-1) expression in pancreatic ductal adenocarcinoma (PDAC) cells through lysosomal-autophagy-dependent degradation. In mouse models of PDAC, either tumor cell overexpression or pharmacologic activation of NDRG1 leads to MHC-1 upregulation in tumor cells, which in turn promotes the infiltration and activity of CD8 + T cells, enhances anti-tumor immunity, and overcomes resistance to ICB therapy. Moreover, combination therapy of CA-4 and ICB overcomes the drug resistance of pancreatic cancer to ICB therapy. In PDAC patients, NDRG1 expression correlates with high MHC-1 expression and better survival. ConclusionOur results reveal NDRG1 in PDAC cancer cells as a tumor suppressor and suggest that pharmaceutically targeting NDRG1 is a promising way to overcome pancreatic cancer resistance to immunotherapy and provides a potential therapeutic strategy for the treatment of pancreatic cancer patients.

Overcoming the limitations of immunotherapy in pancreatic ductal adenocarcinoma: Combining radiotherapy and metabolic targeting therapy.

As a novel anticancer therapy, immunotherapy has demonstrated robust efficacy against a few solid tumors but poor efficacy against pancreatic ductal adenocarcinoma (PDAC). This poor outcome is primarily attributable to the intrinsic cancer cell resistance and T-cell exhaustion, which is also the reason for the failure of conventional therapy. The present review summarizes the current PDAC immunotherapy avenues and the underlying resistance mechanisms. Then, the review discusses synergistic combination therapies, such as radiotherapy (RT) and metabolic targeting. Research suggests that RT boosts the antigen of PDAC, which facilitates the anti-tumor immune cell infiltration and exerts function. Metabolic reprogramming contributes to restoring the exhausted T cell function. The current review will help in tailoring combination regimens to enhance the efficacy of immunotherapy. In addition, it will help provide new approaches to address the limitations of the immunosuppressive tumor microenvironment (TME) by examining the relationship among immunotherapy, RT, and metabolism targeting therapy in PDAC.

Plectin-1-targeted recognition for enhancing comprehensive therapy in pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) poses a formidable challenge due to its aggressive nature and poor prognosis. Gemcitabine (Gem), a primary therapeutic option, functions by inhibiting DNA synthesis and promoting apoptosis, thereby impeding the progression of PDAC. However, Gem is hindered by suboptimal pharmacokinetics and efficacy. In response to these challenges, we have developed a nanoparticle (NP) designed for specific recognition of plectin-1 in PDAC cell membranes. The NPs encapsulate Gem while demonstrating pH-responsive drug release characteristics in the acidic tumor microenvironment. This targeted approach enhances local drug delivery while alleviating concerns about systemic toxicity. Furthermore, the NPs are enriched with indocyanine green (ICG), renowned for its strong photothermal effects, thereby further enhancing therapeutic outcomes. This study presents an innovative therapeutic strategy for PDAC based on a plectin-1-targeted recognition delivery approach. The approach is applied to enhance chemotherapy, combined with photothermal therapy (PTT), inducing apoptosis in PDAC cell lines and improving the pharmacokinetics of Gem. In conclusion, the delivery strategy based on plectin-1-targeted recognition shows promising preclinical prospects for enhancing therapeutic efficacy in PDAC, offering valuable insights for future clinical applications.

Vasohibin-2-Targeting Therapies for the Treatment of Pancreatic Ductal Adenocarcinoma.

As pancreatic ductal adenocarcinoma (PDAC) is extremely malignant and refractory, therapeutic options for this cancer are anticipated worldwide. We isolated vasohihibin-2 (VASH2) and observed its overexpression in various types of cancer. We then noticed that upregulated expression of VASH2 in patients with PDAC resulted in a conspicuous reduction in the postoperative survival period and further revealed that the abrogation of Vash2 expression in pancreatic cancer cells inhibited its growth and metastasis and augmented tumor infiltration of CD8+ cells in the mouse model. We developed VASH2-targeting therapies, 2',4'-BNA-based antisense oligonucleotide targeting VASH2 (VASH2-ASO) as a nucleotide-based therapy, and VASH2-peptide vaccine as an antibody-based therapy. We also showed that the VASH2-peptide vaccine inhibited PDAC metastasis in an orthotopic mouse model. Here, we expanded our analysis of the efficacy of VASH2-targeting therapies for PDAC. VASH2-ASO treatment inhibited the growth of primary tumors by reducing tumor angiogenesis, normalizing tumor vessels, preventing ascites accumulation and distant metastasis to the liver and lungs, and augmenting the infiltration of CD8+ cells in metastatic tumors. VASH2-peptide vaccine did not affect the infiltration of CD8+ cells into tumors. The present study revealed that VASH2-targeting therapies are promising options for the treatment of PDAC. VASH2-ASO therapy can be administered at any stage of PDAC. Because of the increase of CD8+ cell infiltration, the combination therapy with immune checkpoint inhibitors may be an attractive option. The VASH2-peptide vaccine therapy may be useful for preventing metastasis and/or recurrence after successful initial treatment.

Blockade of DDR1/PYK2/ERK signaling suggesting SH2 superbinder as a novel autophagy inhibitor for pancreatic cancer

Pancreatic cancer is highly lethal, of which 90% is pancreatic ductal adenocarcinoma (PDAC), with a 5-year survival rate of less than 12%, lacking effective treatment options and late diagnosis. Furthermore, the tumors show an intense resistance to cytotoxic chemotherapies. As autophagy is elevated in PDAC, targeting the autophagic pathway is regarded as a promising strategy for cancer treatment. Immunofluorescence and transmission electron microscopy were utilized to assess the autophagic flux. Label-free quantitative phosphoproteomics was used to figure out critically altered tyrosine phosphorylation of the proteins. Tumor-bearing mice were used to validate that SH2 TrM-(Arg)9 restrained the growth of tumor cells. SH2 TrM-(Arg)9 inhibited collagen-induced autophagy via blocking the DDR1/PYK2/ERK signaling cascades. SH2 TrM-(Arg)9 improved the sensitivity of PANC-1/GEM cells to gemcitabine (GEM). Inhibition of autophagy by SH2 TrM-(Arg)9 may synergized with chemotherapy and robusted tumor suppression in pancreatic cancer xenografts. SH2 TrM-(Arg)9 could enter into PDAC cells and blockade autophagy through inhibiting DDR1/PYK2/ERK signaling and may be a new treatment strategy for targeted therapy of PDAC.

Evaluating the caregiver experience during neoadjuvant therapy for pancreatic ductal adenocarcinoma.

Neoadjuvant therapy (NT) is increasingly recommended for patients with localized pancreatic ductal adenocarcinoma (PDAC). Recent research has highlighted the significant treatment burden that patients experience during NT, but caregiver well-being during NT is poorly understood. A cross-sectional mixed-methods analysis of primary caregivers of patients with localized PDAC receiving NT was undertaken. All patients completed the Caregiver Quality of Life Index-Cancer (CQOLC) survey, while semi-structured interviews were conducted among a convenience sample of participants. Among 28 caregivers, the mean age was 60.1 years, and most were patient spouses/significant others (71.4%). Patients had resectable (18%), borderline resectable (46%), or locally advanced (36%) PDAC with a mean treatment duration of 2.9 months at the time of their caregiver's enrollment. Most caregivers felt that they received adequate emotional/psychosocial support (80%) and understood the rationale for NT (93%). A majority (60%) reported that caregiving responsibilities impacted their daily lives and required a decrease in their work hours, leading to financial challenges (47%). While overall QOL was moderate (mean 83 ± 21.1, range 0-140), "emotional burden" (47.3 ± 20.9), and "positive adaption" (57.3 ± 13.9) were the lowest ranked CQOLC subsection scores. Caregivers of patients with PDAC undergoing NT experience significant emotional symptoms and impact on their daily lives. Assessing caregiver needs and providing resources during NT should be a priority.

Reprogramming the pancreatic cancer stroma and immune landscape by a silicasome nanocarrier delivering nintedanib, a protein tyrosine kinase inhibitor

The prevailing desmoplastic stroma and immunosuppressive microenvironment within pancreatic ductal adenocarcinoma (PDAC) pose substantial challenges to therapeutic intervention. Despite the potential of protein tyrosine kinase (PTK) inhibitors in mitigating the desmoplastic stromal response and enhancing the immune milieu, their efficacy is curtailed by suboptimal pharmacokinetics (PK) and insufficient tumor penetration. To surmount these hurdles, we have pioneered a novel strategy, employing lipid bilayer-coated mesoporous silica nanoparticles (termed "silicasomes") as a carrier for the delivery of Nintedanib. Nintedanib, a triple PTK inhibitor that targets vascular endothelial growth factor, platelet-derived growth factor and fibroblast growth factor receptors, was encapsulated in the pores of silicasomes via a remote loading mechanism for weak bases. This innovative approach not only enhanced pharmacokinetics and intratumor drug concentrations but also orchestrated a transformative shift in the desmoplastic and immune landscape in a robust orthotopic KRAS-mediated pancreatic carcinoma (KPC) model. Our results demonstrate attenuation of vascular density and collagen content through encapsulated Nintedanib treatment, concomitant with significant augmentation of the CD8+/FoxP3+ T-cell ratio. This remodeling was notably correlated with tumor regression in the KPC model. Strikingly, the synergy between encapsulated Nintedanib and anti-PD-1 immunotherapy further potentiated the antitumor effect. Both free and encapsulated Nintedanib induced a transcriptional upregulation of PD-L1 via the extracellular signal-regulated kinase (ERK) pathway. In summary, our pioneering approach involving the silicasome carrier not only improved antitumor angiogenesis but also profoundly reshaped the desmoplastic stromal and immune landscape within PDAC. These insights hold excellent promise for the development of innovative combinatorial strategies in PDAC therapy.

Tumor Size Reduction and Serum Carbohydrate Antigen 19-9 Kinetics After Neoadjuvant FOLFIRINOX in Patients With Pancreatic Ductal Adenocarcinoma

BackgroundChanges in tumor size and serum carbohydrate antigen 19-9 are commonly reported markers used to assess response to neoadjuvant therapy in pancreatic ductal adenocarcinoma. We evaluated the impact of the percentual tumor size reduction and carbohydrate antigen 19-9 kinetics on resectability and response to neoadjuvant FOLFIRINOX. MethodsThis was an institutional analysis of patients with non-metastatic (upfront resectable, borderline resectable, and locally advanced) pancreatic ductal adenocarcinoma who underwent neoadjuvant FOLFIRINOX. Resectability, pathologic response, disease recurrence, and overall survival were evaluated. ResultsAmong 193 patients who completed FOLFIRINOX, 60% underwent resection, and 91% were R0. Pathologically, complete, and near-complete responses were achieved in 4% and 40% of patients, respectively. Tumor size reduction (odds ratio 1.02 per 1%, P = .024) and normalization of carbohydrate antigen 19-9 (odds ratio 2.61, P = .035) were associated with increased odds of resectability. Concerning pathologic response, tumor size reduction (odds ratio 1.03 per 1%, P = .018) was associated with increased odds of a complete and near-complete response. Lastly, in resected patients, a postoperative increase in carbohydrate antigen 19-9 after prior normalization after neoadjuvant therapy were at an increased risk of recurrence (hazard ratio 9.58, P < .001) and worse survival (hazard ratio 10.4, P < .001) compared to patients who maintained normalization. ConclusionIn patients with non-metastatic pancreatic ductal adenocarcinoma who underwent neoadjuvant therapy, tumor size reduction was a significant predictor of resectability and pathologic response, including complete and near complete responses, whereas serum carbohydrate antigen 19-9 normalization predicted resectability, disease recurrence, and survival. Patients with a postoperative carbohydrate antigen 19-9 rise after prior normalization after administration of neoadjuvant therapy were at an increased risk of recurrence and worse overall survival.

AUM302, a novel triple kinase PIM/PI3K/mTOR inhibitor, is a potent in vitro pancreatic cancer growth inhibitor.

Pancreatic cancer is one of the leading causes of cancer deaths, with pancreatic ductal adenocarcinoma (PDAC) being the most common subtype. Advanced stage diagnosis of PDAC is common, causing limited treatment opportunities. Gemcitabine is a frequently used chemotherapeutic agent which can be used as a monotherapy or in combination. However, tumors often develop resistance to gemcitabine. Previous studies show that the proto-oncogene PIM kinases (PIM1 and PIM3) are upregulated in PDAC compared to matched normal tissue and are related to chemoresistance and PDAC cell growth. The PIM kinases are also involved in the PI3K/AKT/mTOR pathway to promote cell survival. In this study, we evaluate the effect of the novel multikinase PIM/PI3K/mTOR inhibitor, AUM302, and commercially available PIM inhibitor, TP-3654. Using five human PDAC cell lines, we found AUM302 to be a potent inhibitor of cell proliferation, cell viability, cell cycle progression, and phosphoprotein expression, while TP-3654 was less effective. Significantly, AUM302 had a strong impact on the viability of gemcitabine-resistant PDAC cells. Taken together, these results demonstrate that AUM302 exhibits antitumor activity in human PDAC cells and thus has the potential to be an effective drug for PDAC therapy.

Combination therapy of niclosamide with gemcitabine inhibited cell proliferation and apoptosis via Wnt/β-catenin/c-Myc signaling pathway by inducing β-catenin ubiquitination in pancreatic cancer

ABSTRACT Pancreatic ductal adenocarcinoma (PDAC) is a type of cancer with high morbidity and mortality rates worldwide. Owing to a lack of therapeutic options, the overall survival rate of patients with pancreatic cancer is low. Gemcitabine has been mainly used to treat patients with pancreatic cancer, but its efficacy is limited by chemoresistance. Therefore, a novel therapeutic agent for PDAC therapy is urgently needed. An anthelminthic drug, niclosamide, has already been researched in breast, lung, colon, and pancreatic cancer as an anti-cancer purpose by re-positioning its original purpose. However, combination therapy of gemcitabine and niclosamide was not informed yet. Here, we found that niclosamide co-administered with gemcitabine significantly inhibited tumorigenesis of pancreatic cancer compared to gemcitabine alone. Further, combining niclosamide and gemcitabine inhibited cell proliferation and induced apoptosis. Niclosamide induced cell cycle arrest at the G1 phase, and the levels of CDK4/6 and cyclin D1 were lowered after gemcitabine treatment. In addition, the combination of these chemical compounds more effectively increased the binding level of activated β-catenin destruction complex and β-catenin to enable phosphorylation, compared to gemcitabine alone. After phosphorylation, niclosamide – gemcitabine upregulated the ubiquitin level, which caused phosphorylated β-catenin to undergo proteasomal degradation; the combination was more potent than gemcitabine alone. Finally, the combination more effectively suppressed tumor growth in vivo, compared to gemcitabine alone. Altogether, our results indicate that niclosamide synergistically enhances the antitumor effect of gemcitabine in pancreatic cancer, by inducing the degradation of β-catenin with ubiquitination. Therefore, this drug combination can potentially be used in PDAC therapy.

The Expression of Two Distinct Sets of Glycolytic Enzymes Reveals Differential Effects of Glycolytic Reprogramming on Pancreatic Ductal Tumorigenesis in Mice.

Pancreatic ductal adenocarcinoma (PDAC) is associated with enhanced aerobic glycolysis through elevated glucose uptake and the upregulated expression of genes encoding rate-limiting glycolytic enzymes. However, the direct impact of altered glycolytic pathways on pancreatic tumor progression has not been thoroughly investigated. Here, we utilized two strains of BAC transgenic mice with pancreatic expression of two distinct sets of glycolytic genes each arranged in a polycistronic fashion (PFKFB3-HK2-GLUT1 and LDHA-PDK1, respectively) to investigate the role of altered glycolysis on the development of pancreatic ductal tumor development in the Pdx1-Cre; LSL-KrasG12D mice. The overexpression of the two sets of glycolytic genes exhibited no significant effects on tumor development in the 4-5-month-old mice (the PanIN2 lesions stage). In the 9-10-month-old mice, the overexpression of PFKFB3-HK2-GLUT1 significantly accelerated PanIN3 progression, exhibiting elevated levels of ductal cell marker CK19 and tumor fibrosis. Surprisingly, the overexpression of LDHA-PDK1 significantly attenuated the progression of PanIN3 in the 9-10-month-old mice with significantly downregulated levels of CK19 and fibrosis. Therefore, distinct set of glycolytic enzymes that are involved in different glycolytic routes exhibited contrasting effects on pancreatic ductal tumor development depending on the tumor stages, providing novel insights into the complexity of the glycolytic pathway in the perspective of PDAC development and therapy.

Therapeutic Strategies for Pancreatic-Cancer-Related Type 2 Diabetes Centered around Natural Products.

Pancreatic ductal adenocarcinoma (PDAC), a highly malignant neoplasm, is classified as one of the most severe and devastating types of cancer. PDAC is a notable malignancy that exhibits a discouraging prognosis and a rising occurrence. The interplay between diabetes and pancreatic cancer exhibits a reciprocal causation. The identified metabolic disorder has been observed to possess noteworthy consequences on health outcomes, resulting in elevated rates of morbidity. The principal mechanisms involve the suppression of the immune system, the activation of pancreatic stellate cells (PSCs), and the onset of systemic metabolic disease caused by dysfunction of the islets. From this point forward, it is important to recognize that pancreatic-cancer-related diabetes (PCRD) has the ability to increase the likelihood of developing pancreatic cancer. This highlights the complex relationship that exists between these two physiological states. Therefore, we investigated into the complex domain of PSCs, elucidating their intricate signaling pathways and the profound influence of chemokines on their behavior and final outcome. In order to surmount the obstacle of drug resistance and eliminate PDAC, researchers have undertaken extensive efforts to explore and cultivate novel natural compounds of the next generation. Additional investigation is necessary in order to comprehensively comprehend the effect of PCRD-mediated apoptosis on the progression and onset of PDAC through the utilization of natural compounds. This study aims to examine the potential anticancer properties of natural compounds in individuals with diabetes who are undergoing chemotherapy, targeted therapy, or immunotherapy. It is anticipated that these compounds will exhibit increased potency and possess enhanced pharmacological benefits. According to our research findings, it is indicated that naturally derived chemical compounds hold potential in the development of PDAC therapies that are both safe and efficacious.

SDC1 and ITGA2 as novel prognostic biomarkers for PDAC related to IPMN

The existing biomarkers are insufficient for predicting the prognosis of pancreatic ductal adenocarcinoma (PDAC). Intraductal papillary mucinous neoplasm (IPMN) is a precursor to PDAC; therefore, identifying biomarkers from differentially expressed genes (DEGs) of PDAC and IPMN is a new and reliable strategy for predicting the prognosis of PDAC. In this study, four datasets were downloaded from the Gene Expression Omnibus database and standardized using the R package ‘limma.’ A total of 51 IPMN and 81 PDAC samples were analyzed, and 341 DEGs in PDAC and IPMN were identified; DEGs were involved in the extracellular matrix and tumor microenvironment. An acceptable survival prognosis was demonstrated by SDC1 and ITGA2, which were highly expressed during in vitro PDAC cell proliferation, apoptosis, and migration. SDC1high was enriched in interferon alpha (IFN-α) response and ITGA2high was primarily detected in epithelial-mesenchymal transition (EMT), which was verified using western blotting. We concluded that SDC1 and ITGA2 are potential prognostic biomarkers for PDAC associated with IPMN. Downregulation of SDC1 and ITGA2 expression in PDAC occurs via a mechanism involving possible regulation of IFN-α response, EMT, and immunity, which may act as new targets for PDAC therapy.

A Small Molecule with Big Impact: MRTX1133 Targets the KRASG12D Mutation in Pancreatic Cancer.

KRAS mutations drive oncogenic alterations in numerous cancers, particularly in human pancreatic ductal adenocarcinoma (PDAC). About 93% of PDACs have KRAS mutations, with G12D (∼42% of cases) and G12V (∼32% of cases) being the most common. The recent approval of sotorasib (AMG510), a small-molecule, covalent, and selective KRASG12C inhibitor, for treating patients with non-small cell lung cancer represents a breakthrough in KRAS targeted therapy. However, there is a need to develop other much-needed KRAS-mutant inhibitors for PDAC therapy. Notably, Mirati Therapeutics recently developed MRTX1133, a small-molecule, noncovalent, and selective KRASG12D inhibitor through extensive structure-based drug design. MRTX1133 has demonstrated potent in vitro and in vivo antitumor efficacy against KRASG12D-mutant cancer cells, especially in PDAC, leading to its recent initiation of a phase I/II clinical trial. Here, we provide a summary of the recent advancements related to the use of MRTX1133 for treating KRASG12D-mutant PDAC, focusing on its efficacy and underlying mechanistic actions. In addition, we discuss potential challenges and future directions for MRTX1133 therapy for PDAC, including overcoming intrinsic and acquired drug resistance, developing effective combination therapies, and improving MRTX1133's oral bioavailability and target spectrum. The promising results obtained from preclinical studies suggest that MRTX1133 could revolutionize the treatment of PDAC, bringing about a paradigm shift in its management.

Hydrogel-Based Therapeutics for Pancreatic Ductal Adenocarcinoma Treatment.

Pancreatic ductal adenocarcinoma (PDAC), one of the deadliest malignancies worldwide, is characteristic of the tumor microenvironments (TME) comprising numerous fibroblasts and immunosuppressive cells. Conventional therapies for PDAC are often restricted by limited drug delivery efficiency, immunosuppressive TME, and adverse effects. Thus, effective and safe therapeutics are urgently required for PDAC treatment. In recent years, hydrogels, with their excellent biocompatibility, high drug load capacity, and sustainable release profiles, have been developed as effective drug-delivery systems, offering potential therapeutic options for PDAC. This review summarizes the distinctive features of the immunosuppressive TME of PDAC and discusses the application of hydrogel-based therapies in PDAC, with a focus on how these hydrogels remodel the TME and deliver different types of cargoes in a controlled manner. Furthermore, we also discuss potential drug candidates and the challenges and prospects for hydrogel-based therapeutics for PDAC. By providing a comprehensive overview of hydrogel-based therapeutics for PDAC treatment, this review seeks to serve as a reference for researchers and clinicians involved in developing therapeutic strategies targeting the PDAC microenvironment.

Personalized treatment in localized pancreatic cancer

SummaryThe treatment elements used for pancreatic ductal adenocarcinoma (PDAC) include surgical resection, systemic cytotoxic agents, and targeted drugs. For second- and third-line therapies in PDAC, approximately 15% of patients have actionable mutations although only 2.5% receive matched targeted treatment but with a significant improvement in survival of around 16 months. For the majority of PDAC patients the current most effective strategy is surgical resection of the primary tumor and systemic combination chemotherapy. The chemotherapy regimens and the order of delivery relative to the resection reference point have been based to a large extent on randomized trials using a newly developed empirical staging (Em) system. Although the reductionist TNM based AJCC and UICC systems work well for pathology staging, they are less accurate and less manageable for treatment decision-making. This Em system defines locally resectable (EmR), borderline resectable (EmBR), and unresectable (EmUR) stages, plus the emerging entity of oligometastatic disease (EmOm). For EmR patients, 6 months of adjuvant chemotherapy achieves 5‑year survival rates of 30–50%. In EmBR short-course (2 months) neoadjuvant plus 6‑month adjuvant chemotherapy increases 12-month survival rates to around 77%, compared to 40% for upfront surgery, despite resection rates of 64–85% and 75%, respectively. Longer-course (4 months) neoadjuvant chemotherapy has also been shown to achieve an 18-month overall survival of 67%. In EmUR, induction therapy (3–6 months) may result in resections rates of 20–60% with significantly improved survival rates compared to no resection. For all stages including the polymetastatic (EmPm) setting, patients with good performance status receive combination chemotherapies based on either oxaliplatin (FOLFIRINOX or NALIRIFOX) or gemcitabine (GEM-CAP, or Gem-NabP). Molecular subtypes (Moffitt, Collisson, Bailey, and Cheng-Sen-Yue) are shown to be associated with treatment responses. Transcriptomic signatures have also been developed as classifiers for determining either oxaliplatin- or gemcitabine-based therapies (PurIST, Tiriac, GemPred+, and ESPAC) and are being evaluated in various studies. Most notably the ESPAC transcriptomic signature is being used as the treatment classifier in the experimental arms of the randomized ESPAC6 adjuvant trial in EmR patients and the ESPAC7 induction therapy trial in EmUR patients. Genomic and transcriptomic profiling at baseline and over time is an integral part of ESPAC6/7 to deepen our understanding of tumor plasticity during the course of therapy, identifying the intrinsic (persister cell) and acquired (genetic) tumor plasticity evolving over time and in reaction to different therapies in order to enable a scientific approach to overcoming clonal-resistance clades.

Characterization of acute and subacute immune response to boiling histotripsy ablation of pancreatic adenocarcinoma

Boiling histotripsy (BH) is a cavitation-based pulsed focused ultrasound method of mechanical tissue disintegration. When applied to tumor ablation, BH was shown in a number of preclinical studies to stimulate antitumor immune responses, with the extent and dynamics depending on the tumor microenvironment. In this work, we assessed the response of pancreatic ductal adenocarcinoma (PDAC)—an immunologically “cold” tumor—to BH ablation. C57BL/6J mice (n = 6 per group) were bilaterally subcutaneously grafted with KPC-derived mT4 cell line in the hind limbs. When one of the two tumors reached 8 mm, 80% of its volume was ablated with BH (1.5 MHz, 3 ms pulses, 1% duty cycle, 450 W power, 15 pulses/point). The tumors, inguinal lymph nodes and spleens were harvested at 1-, 3-, and 6-day time points and processed for immune phenotyping through flow cytometry, histology, and immunohistochemistry. At earlier time points, the response within the tumor was dominated by neutrophils, and by day 6—by inflammatory monocytes both in treated and contralateral sides versus sham. Transient increases in B cells, neutrophils, NK, NKT cells, and monocytes were observed in the ipsilateral lymph nodes and in spleens on day 3, and mostly subsided by day 6. These data will inform further studies in optimization of combination therapies for PDAC. [Work supported by Focused Ultrasound Foundation.]

CXCR4-modified CAR-T cells suppresses MDSCs recruitment via STAT3/NF-κB/SDF-1α axis to enhance efficacy against pancreatic cancer

Claudin18.2 (CLDN18.2)-specific chimeric antigen receptor (CAR-T) cells displayed limited efficacy in CLDN18.2-positive pancreatic ductal adenocarcinoma (PDAC). Strategies are needed to improve the trafficking capacity of CLDN18.2-specific CAR-T cells. PDAC has a unique microenvironment that consists of abundant cancer-associated fibroblasts (CAFs), which could secrete stromal cell-derived factor 1α (SDF-1α), the ligand of CXCR4. Then, we constructed and explored CLDN18.2-targeted CAR-T cells with CXCR4 co-expression in treating immunocompetent mouse models of PDAC. The results indicated that CXCR4 could promote the infiltration of CAR-T cells and enhance their efficacy invivo. Mechanistically, the activation of signal transducer and activator of transcription 3 (STAT3) signaling was impaired in CXCR4 CAR-T cells, which reduced the release of inflammatory factors, such as tumor necrosis factor-α, IL-6, and IL-17A. Then, the lower release of inflammatory factors suppressed SDF-1α secretion in CAFs via the nuclear factor κB (NF-κB) pathway. Therefore, the decreased secretion of SDF-1α in feedback decreased the migration of myeloid-derived suppressor cells (MDSCs) in tumor sites. Overall, our study demonstrated that CXCR4 CAR-T cells could traffic more into tumor sites and also suppress MDSC migration via the STAT3/NF-κB/SDF-1α axis to obtain better efficacy in treating CLDN18.2-positive pancreatic cancer. Our findings provide a theoretical rationale for CXCR4 CAR-T cell therapy in PDAC.

An integrated overview of the immunosuppression features in the tumor microenvironment of pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest malignancies. It is characterized by a complex and immunosuppressive tumor microenvironment (TME), which is primarily composed of tumor cells, stromal cells, immune cells, and acellular components. The cross-interactions and -regulations among various cell types in the TME have been recognized to profoundly shape the immunosuppression features that meaningfully affect PDAC biology and treatment outcomes. In this review, we first summarize five cellular composition modules by integrating the cellular (sub)types, phenotypes, and functions in PDAC TME. Then we discuss an integrated overview of the cross-module regulations as a determinant of the immunosuppressive TME in PDAC. We also briefly highlight TME-targeted strategies that potentially improve PDAC therapy.