Regulation and modulation of antitumor immunity in pancreatic cancer

Single-Cell Sequencing and Transcriptome Analysis Explored Changes in Midnolin-Related Immune Microenvironment and Constructed Combined Prognostic Model for Pancreatic Cancer

Background

Pancreatic cancer has one of the worst prognoses of any malignant tumor. The value of MIDN, midnolin-related genes and midnolin-related immune infiltrating cells (MICs) in the prognosis of pancreatic cancer remains unknown.

Methods

Single-cell analysis were used to identify midnolin-related genes. Immune cell infiltration was obtained using CIBERSORT. The prognostic midnolin-related genes were identified through the utilization of Cox regression and the least absolute selection operator (LASSO) approach. The combined prognostic model was created using multifactorial Cox regression analysis. Survival analyses, immune microenvironment assessments, drug sensitivity checks were performed to evaluate the combined model performance. Finally, cellular experiments were carried out to confirm MIDN significance in pancreatic cancer.

Results

The combined model was constructed based on MIDN expression, prognostic model of 10 midnolin-related genes and M1 cell infiltration. Most immune checkpoint-related genes were expressed at greater levels in the low-risk group, suggesting a greater chance of immunotherapy's benefits. The most significant model gene, MIDN, was shown to have a function by cellular tests. In pancreatic cancer, MIDN knockdown drastically decreased pancreatic cancer cell lines' activity, proliferation, and invasive potential.

Conclusion

The combined model helped assess the prognosis of pancreatic cancer and offered fresh perspectives on immunotherapy in particular.

Implications of intratumoral microbiota in tumor metastasis: a special perspective of microorganisms in tumorigenesis and clinical therapeutics

Tumor metastasis is the main cause of therapeutic failure and mortality in cancer patients. The intricate metastastic process is influenced by both the intrinsic properties of tumor cells and extrinsic factors, such as microorganisms. Notably, some microbiota have been discovered to colonize tumor tissues, collectively known as intratumoral microbiota. Intratumoral microbiota can modulate tumor progression through multiple mechanisms, including regulating immune responses, inducing genomic instability and gene mutations, altering metabolic pathways, controlling epigenetic pathways, and disrupting cancer-related signaling pathways. Furthermore, intratumoral microbiota have been shown to directly impact tumor metastasis by regulating cell adhesion, stem cell plasticity and stemness, mechanical stresses and the epithelial-mesenchymal transition. Indirectly, they may affect tumor metastasis by modulating the host immune system and the tumor microenvironment. These recent findings have reshaped our understanding of the relationship between microorganims and the metastatic process. In this review, we comprehensively summarize the existing knowledge on tumor metastasis and elaborate on the properties, origins and carcinogenic mechanisms of intratumoral microbiota. Moreover, we explore the roles of intratumoral microbiota in tumor metastasis and discuss their clinical implications. Ongoing research in this field will establish a solid foundation for novel therapeutic strategies and clinical treatments for various tumors.

Longitudinal Circulating Tumor Cell Collection, Culture, and Characterization in Pancreatic Adenocarcinomas

BACKGROUND/OBJECTIVES

Pancreatic adenocarcinoma (PDAC) remains one of the most lethal cancers, with limited advancements in treatment efficacy due to high rates of chemoresistance. Circulating tumor cells (CTCs) derived from liquid biopsies offer a non-invasive approach to monitoring tumor evolution and identifying molecular mechanisms of resistance. This study aims to longitudinally collect, culture, and characterize CTCs from PDAC patients to elucidate resistance mechanisms and tumor-specific gene expression profiles.

METHODS

Blood samples from 10 PDAC patients were collected across different treatment stages, yielding 16 CTC cultures. Differential gene expression, pathway dysregulation, and protein-protein interaction studies were utilized, highlighting patient-specific and disease progression-associated changes. Longitudinal comparisons within five patients provided further insights into dynamic molecular changes associated with therapeutic resistance.

RESULTS

CTC cultures exhibited the activation of key pathways implicated in PDAC progression and resistance, including TNFα/NF-kB, hedgehog signaling, and the epithelial-to-mesenchymal transition. Longitudinal samples revealed dynamic changes in signaling pathways, highlighting upregulated mechanisms of chemoresistance, including PI3K/Akt/mTOR and TGF-β pathways. Additionally, protein-protein interaction analysis emphasized the role of the immune system in PDAC progression and therapy response. Patient-specific gene expression patterns therefore suggest potential applications for precision medicine.

CONCLUSIONS

This proof-of-concept study demonstrates the feasibility of longitudinally capturing and analyzing CTCs from PDAC patients. The findings provide critical insights into molecular drivers of chemoresistance and highlight the potential of CTC profiling to inform personalized therapeutic strategies. Future large-scale studies are warranted to validate these findings and further explore CTC-based approaches in PDAC management.

Progress in the Study of Intratumoral Microorganisms in Hepatocellular Carcinoma

The intratumoral microbiota, an integral part of liver tumors, has garnered significant attention from researchers due to its role in tumor development regulation and impact on cancer treatment. Intratumoral microorganism not only influences tumorigenesis and progression, but also serves as potential biomarkers and targets for tumor therapy. Targeted manipulation of these microorganisms holds great promise for personalized liver cancer treatment. However, there is a lack of systematic summaries and reports on the study of intratumoral microorganism in hepatocellular carcinoma. This comprehensive review aims to address this gap by summarizing research progress related to in the field of hepatocellular carcinoma intratumoral bacteria, including their sources, types, distribution characteristics within tumors, impact on tumor development, underlying mechanisms, and application prospects. Through the analysis, it is proposed that intratumor organisms can be used as markers for liver cancer diagnosis and treatment, drug carrier materials for targeting liver cancer tissues, and the research prospects of developing new combination therapies based on the in-depth understanding of the interactions between intratumor microorganisms and the tumor microenvironment, immune cells, liver cancer cells, etc. as well as exploring the prospects of developing new combination therapies based on these interactions. It is hoped that from the perspective of intratumoral microbiota, potential theoretical support can be provided for future research on targeted cancer therapy for liver cancer intratumoral microbiota, and new insights and ideas can be provided for targeting points and research methods in tumor research.

Intratumoral Fusobacterium nucleatum in Pancreatic Cancer: Current and Future Perspectives

The intratumoral microbiome plays a significant role in many cancers, such as lung, pancreatic, and colorectal cancer. Pancreatic cancer (PC) is one of the most lethal malignancies and is often diagnosed at advanced stages. Fusobacterium nucleatum (Fn), an anaerobic Gram-negative bacterium primarily residing in the oral cavity, has garnered significant attention for its emerging role in several extra-oral human diseases and, lately, in pancreatic cancer progression and prognosis. It is now recognized as oncobacterium. Fn engages in pancreatic tumorigenesis and metastasis through multifaceted mechanisms, including immune response modulation, virulence factors, control of cell proliferation, intestinal metabolite interactions, DNA damage, and epithelial-mesenchymal transition. Additionally, compelling research suggests that Fn may exert detrimental effects on cancer treatment outcomes. This paper extends the perspective to pancreatic cancer associated with Fn. The central focus is to unravel the oncogenomic changes driven by Fn in colonization, initiation, and promotion of pancreatic cancer development. The presence of Fusobacterium species can be considered a prognostic marker of PC, and it is also correlated to chemoresistance. Furthermore, this review underscores the clinical research significance of Fn as a potential tumor biomarker and therapeutic target, offering a novel outlook on its applicability in cancer detection and prognostic assessment. It is thought that given the role of Fn in tumor formation and metastasis processes via its FadA, FapA, Fap2, and RadD, new therapies for tumor treatment targeting Fn will be developed.

Plasticity and Tumor Microenvironment in Pancreatic Cancer: Genetic, Metabolic, and Immune Perspectives

Cancer has long been believed to be a genetic disease caused by the accumulation of mutations in key genes involved in cellular processes. However, recent advances in sequencing technology have demonstrated that cells with cancer driver mutations are also present in normal tissues in response to aging, environmental damage, and chronic inflammation, suggesting that not only intrinsic factors within cancer cells, but also environmental alterations are important key factors in cancer development and progression. Pancreatic cancer tissue is mostly comprised of stromal cells and immune cells. The desmoplasmic microenvironment characteristic of pancreatic cancer is hypoxic and hypotrophic. Pancreatic cancer cells may adapt to this environment by rewiring their metabolism through epigenomic changes, enhancing intrinsic plasticity, creating an acidic and immunosuppressive tumor microenvironment, and inducing noncancerous cells to become tumor-promoting. In addition, pancreatic cancer has often metastasized to local and distant sites by the time of diagnosis, suggesting that a similar mechanism is operating from the precancerous stage. Here, we review key recent findings on how pancreatic cancers acquire plasticity, undergo metabolic reprogramming, and promote immunosuppressive microenvironment formation during their evolution. Furthermore, we present the following two signaling pathways that we have identified: one based on the small G-protein ARF6 driven by KRAS/TP53 mutations, and the other based on the RNA-binding protein Arid5a mediated by inflammatory cytokines, which promote both metabolic reprogramming and immune evasion in pancreatic cancer. Finally, the striking diversity among pancreatic cancers in the relative importance of mutational burden and the tumor microenvironment, their clinical relevance, and the potential for novel therapeutic strategies will be discussed.

MED12 loss activates endogenous retroelements to sensitise immunotherapy in pancreatic cancer

OBJECTIVE

Pancreatic ductal adenocarcinoma (PDAC) stands as one of the most lethal cancers, marked by its lethality and limited treatment options, including the utilisation of checkpoint blockade (ICB) immunotherapy. Epigenetic dysregulation is a defining feature of tumourigenesis that is implicated in immune surveillance, but remains elusive in PDAC.

DESIGN

To identify the factors that modulate immune surveillance, we employed in vivo epigenetic-focused CRISPR-Cas9 screen in mouse PDAC tumour models engrafted in either immunocompetent or immunodeficient mice.

RESULTS

Here, we identified MED12 as a top hit, emerging as a potent negative modulator of immune tumour microenviroment (TME) in PDAC. Loss of Med12 significantly promoted infiltration and cytotoxicity of immune cells including CD8+ T cells, natural killer (NK) and NK1.1+ T cells in tumours, thereby heightening the sensitivity of ICB treatment in a mouse model of PDAC. Mechanistically, MED12 stabilised heterochromatin protein HP1A to repress H3K9me3-marked endogenous retroelements. The derepression of retrotransposons induced by MED12 loss triggered cytosolic nucleic acid sensing and subsequent activation of type I interferon pathways, ultimately leading to robust inflamed TME . Moreover, we uncovered a negative correlation between MED12 expression and immune resposne pathways, retrotransposon levels as well as the prognosis of patients with PDAC undergoing ICB therapy.

CONCLUSION

In summary, our findings underscore the pivotal role of MED12 in remodelling immnue TME through the epigenetic silencing of retrotransposons, offering a potential therapeutic target for enhancing tumour immunogenicity and overcoming immunotherapy resistance in PDAC.

Upregulation of HSD11B1 promotes cortisol production and inhibits NK cell activation in pancreatic adenocarcinoma

Cortisol is a glucocorticoid hormone that has immunosuppressive function. Elevated basal cortisol levels are present in patients with some kinds of cancers, but its role in the microenvironment of pancreatic adenocarcinoma (PAAD) remains unclear. This study analyzed the expression of genes involved in cortisol generation by using high-throughput sequencing data from TCGA portal and found HSD11B1 was significantly upregulated in patients with PAAD. The correlations between HSD11B1 level and the expression of 23 immunosuppressive receptors were analyzed by Spearman's correlation analysis. The function of HSD11B1 was examined in primary NK cells and PAAD cell lines. The levels of cortisol in medium and cell lysates were detected by ELISA. In vitro killing assay was used to evaluate the cytotoxicity of NK cells. Cell surface levels of CD96, Tim-3, PD-1, TIGIT, CTLA-4, NKp46, NKp30, NKD2G and LFA-1A, and intracellular levels of CD107a and IFN-γ were examined by flow cytometry. We observed that patients with higher HSD11B1 level had shorter survival time. HSD11B1 is positively correlated with the mRNA levels of 11 immunosuppressive receptors in PAAD. Higher HSD11B1 level relates to reduced abundance of activated NK cells in the tumors. HSD11B1 overexpressed NK cells exhibit exhausted phenotype with increased cortisol production, reduced viability, and reduced cytotoxicity against cancer cells. Overexpression of HSD11B1 did not change the viability of tumor cells but upregulated cortisol production. Targeting HSD11B1 by a specific inhibitor improved the NK cells responsiveness. In conclusion, HSD11B1 is upregulated in patients with PAAD, and higher HSD11B1 level is related to poor prognosis. Upregulation of HSD11B1 in NK and tumor cells increased the production and secretion of cortisol and induces NK cell exhaustion.

Inflammatory Processes: Key Mediators of Oncogenesis and Progression in Pancreatic Ductal Adenocarcinoma (PDAC)

Associations between inflammation and cancer were first discovered approximately 160 years ago by Rudolf Virchow, who observed that tumors were infiltrated with inflammatory cells, and defined inflammation as a pathological condition. Inflammation has now emerged as one of the key mediators in oncogenesis and tumor progression, including pancreatic ductal adenocarcinoma (PDAC). However, the role of inflammatory processes in cancers is complicated and controversial, and the detailed regulatory mechanisms are still unclear. This review elucidates the dynamic interplay between inflammation and immune regulation, microenvironment alteration, metabolic reprogramming, and microbiome risk factors in PDAC, committing to exploring a deeper understanding of the role of crucial inflammatory pathways and molecules for providing insights into therapeutic strategies.

Consensus, debate, and prospective on pancreatic cancer treatments

Pancreatic cancer remains one of the most aggressive solid tumors. As a systemic disease, despite the improvement of multi-modality treatment strategies, the prognosis of pancreatic cancer was not improved dramatically. For resectable or borderline resectable patients, the surgical strategy centered on improving R0 resection rate is consensus; however, the role of neoadjuvant therapy in resectable patients and the optimal neoadjuvant therapy of chemotherapy with or without radiotherapy in borderline resectable patients were debated. Postoperative adjuvant chemotherapy of gemcitabine/capecitabine or mFOLFIRINOX is recommended regardless of the margin status. Chemotherapy as the first-line treatment strategy for advanced or metastatic patients included FOLFIRINOX, gemcitabine/nab-paclitaxel, or NALIRIFOX regimens whereas 5-FU plus liposomal irinotecan was the only standard of care second-line therapy. Immunotherapy is an innovative therapy although anti-PD-1 antibody is currently the only agent approved by for MSI-H, dMMR, or TMB-high solid tumors, which represent a very small subset of pancreatic cancers. Combination strategies to increase the immunogenicity and to overcome the immunosuppressive tumor microenvironment may sensitize pancreatic cancer to immunotherapy. Targeted therapies represented by PARP and KRAS inhibitors are also under investigation, showing benefits in improving progression-free survival and objective response rate. This review discusses the current treatment modalities and highlights innovative therapies for pancreatic cancer.

BCL6 overexpression in CD4+ T cells induces Tfh-like transdifferentiation and enhances antitumor efficiency of CAR-T therapy in pancreatic cancer

PDAC is a typical "cold tumor" characterized by low immune cell infiltration and a suppressive immune microenvironment. We previously observed the existence of a rare group of follicular helper T cells (Tfh) that could enhance antitumor immune responses by recruiting other immune cells in PDAC. In this study, we ectopically expressed BCL6 in CD4+ T cells, and successfully induced Tfh-like transdifferentiation in vitro. This strategy provided abundant Tfh-like cells (iTfhs) that can recruit CD8+ T cells like endogenous Tfhs. Subsequently, Chimeric Antigen Receptors (CARs) against both MSL (Mesothelin) and EPHA2 (Ephrin receptor A2) were used to modify iTfh cells, and the CAR-iTfh cells significantly improved infiltration and antitumor cytotoxicity of co-cultured CD8+ T cells. After that, combinatory administration of CAR-iTfh & CAR-CD8 T cell therapy displayed a better effect in repressing the PDAC tumors in xenograft mouse models, compared to conventional CAR-CD4 & CAR-CD8 combinations, and the models received the CAR-iTfh & CAR-CD8 T cells displayed a significantly improved survival rate. Our study revealed the plasticity of Thelper differentiation, expanded the source of Tfh-like cells for cell therapy, and demonstrated a novel and potentially more efficient cellular composition for CAR-T therapy.

Panoramic tumor microenvironment in pancreatic ductal adenocarcinoma

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

The MCIB Model: A Novel Theory for Describing the Spatial Heterogeneity of the Tumor Microenvironment

The tumor microenvironment (TME) can be regarded as a complex and dynamic microecosystem generated by the interactions of tumor cells, interstitial cells, the extracellular matrix, and their products and plays an important role in the occurrence, progression and metastasis of tumors. In a previous study, we constructed an IEO model (prI-, prE-, and pOst-metastatic niche) according to the chronological sequence of TME development. In this paper, to fill the theoretical gap in spatial heterogeneity in the TME, we defined an MCIB model (Metabolic, Circulatory, Immune, and microBial microenvironment). The MCIB model divides the TME into four subtypes that interact with each other in terms of mechanism, corresponding to the four major links of metabolic reprogramming, vascular remodeling, immune response, and microbial action, providing a new way to assess the TME. The combination of the MCIB model and IEO model comprehensively depicts the spatiotemporal evolution of the TME and can provide a theoretical basis for the combination of clinical targeted therapy, immunotherapy, and other comprehensive treatment modalities for tumors according to the combination and crosstalk of different subtypes in the MCIB model and provide a powerful research paradigm for tumor drug-resistance mechanisms and tumor biological behavior.

Serum PCSK9 is a novel serological biomarker for the diagnosis and prognosis of pancreatic cancer

Background

Although CA19-9 is an essential blood biomarker of pancreatic cancer (PC), its sensitivity and specificity are limited for early detection.

Methods

We analyzed the serum proprotein convertase subtilisin/kexin type 9 (sPCSK9) in PC patients, benign disease groups (BDG), and healthy controls (HC) by ELISA.

Results

Consistently, sPCSK9 was considerably lower in PC patients than in HC (Z = -2.546, P < 0.05), and sPCSK9 in PC patients was statistically significantly higher than in BDG (Z = -5.457, P < 0.001). sPCSK9 was linked to the invasion of lymph nodes (χ2 = 6.846, P < 0.01). According to ROC curves, combining sPCSK9 with CA19-9 could potentially enhance the diagnostic capability of CA19-9 in early-stage PC patients. Furthermore, the low sPCSK9 group (n = 41) exhibited statistically significantly prolonged overall survival compared to the high sPCSK9 group (n = 15), with median survival times of 27 months (95% CI [17.59-36.41]) and 11 months (95% CI [7.21-14.79]), respectively (P = 0.022).

Conclusion

The diagnostic performance of CA19-9 for early-stage PC patients could be improved by combining sPCSK9 with CA19-9. Moreover, the higher sPCSK9 group has a significantly shorter overall survival rate.

Relevance of harmful intratumoral microbiota in cancer progression and its clinical application

Microorganisms are closely related to human health, and changes in the microbiome can lead to the occurrence of diseases. With advances in sequencing technology and research, it has been discovered that intratumoral microbiota exists in various cancer tissues and differs in various cancers. Microorganism can colonize tumor tissues through intestine of damaged mucosal barrier, proximity to normal tissues and bloodstream circulation. Increasing evidence suggests that intratumoral microbiota promotes tumor progression by increasing genomic instability, affecting host immune systems, promoting tumor migration, and regulating tumor signaling pathways. This review article summarizes the latest progress in intratumoral microbiome research, including the development history of intratumoral microbiota, their composition and sources within tumors, their distribution in various cancer tissues, as well as their role in cancer development. Furthermore, the application of intratumoral microbiota in clinical settings is emphasized and we innovatively summarize the clinical trials involving microbial applications for cancer diagnosis and treatment across different countries.

Kaempferide triggers apoptosis and paraptosis in pancreatic tumor cells by modulating the ROS production, SHP-1 expression, and the STAT3 pathway

Pancreatic cancer is one of the deadliest diseases with a poor prognosis and a five-survival rate. The STAT3 pathway is hyperactivated which contributes to the sustained proliferative signals in pancreatic cancer cells. We have isolated kaempferide (KF), an O-methylated flavonol, from the green propolis of Mimosa tenuiflora and examined its effect on two forms of cell death namely, apoptosis and paraptosis. KF significantly increased the cleavage of caspase-3 and PARP. It also downmodulated the expression of Alix (an intracellular inhibitor of paraptosis) and increased the expression of CHOP and ATF4 (transcription factors that promote paraptosis) indicating that KF promotes apoptosis as well as paraptosis. KF also increased intracellular reactive oxygen species (ROS) suggesting the perturbance of the redox state. N-acetylcysteine reverted the apoptosis- and paraptosis-inducing effects of KF. Some ROS inducers are known to suppress the STAT3 pathway and investigation revealed that KF downmodulates STAT3 and its upstream kinases (JAK1, JAK2, and Src). Additionally, KF also elevated the expression of SHP-1, a tyrosine phosphatase which is involved in the negative modulation of the STAT3 pathway. Knockdown of SHP-1 prevented KF-driven STAT3 inhibition. Altogether, KF has been identified as a promoter of apoptosis and paraptosis in pancreatic cancer cells through the elevation of ROS generation and SHP-1 expression.

Driver mutation subtypes involve with differentiated immunophenotypes influencing pancreatic cancer outcomes

Despite many studies focusing on the prognostic biomarkers in pancreatic adenocarcinomas (PAADs), there is ill-informed about the relationships between their genomic features and immune characteristics. Herein, we deeply investigated the involvement of major driver mutation subtypes with immunophenotypes impacting PAAD outcomes. Based on public data analyses of RNA expression-based immune subtypes in PAAD, in contrast to KRAS G12D & TP53 co-mutant patients with poor outcomes, the best immune subtype C3 (inflammatory) characterized by high Th1/Th2 ratio was relatively enriched in KRASnon-G12DTP53wt patients with better survival, whereas the inferior subtype C2 (IFN-γ dominant) with low Th1/Th2 ratio was more common in the former than in the latter. Moreover, contrary to the highly immunosuppressive microenvironment (high Treg, high ratio of Treg to tumor-specific CD4+ T cell) in KRASG12DTP53mut patients, KRASG12VTP53wt individuals exhibited an inflamed context profiled by multiplex immunohistochemistry. It could be responsible for their outstanding survival advantage over others in postsurgical PAAD patients receiving adjuvant chemotherapy as shown by our cohort. Together, KRASG12VTP53wt may be a promising biomarker for prognostic evaluation and screening certain candidates with PAAD to get desirable survival benefit from adjuvant chemotherapy.

Probiotics functionalized with a gallium-polyphenol network modulate the intratumor microbiota and promote anti-tumor immune responses in pancreatic cancer

The intratumor microbiome imbalance in pancreatic cancer promotes a tolerogenic immune response and triggers immunotherapy resistance. Here we show that Lactobacillus rhamnosus GG probiotics, outfitted with a gallium-polyphenol network (LGG@Ga-poly), bolster immunotherapy in pancreatic cancer by modulating microbiota-immune interactions. Upon oral administration, LGG@Ga-poly targets pancreatic tumors specifically, and selectively eradicates tumor-promoting Proteobacteria and microbiota-derived lipopolysaccharides through a gallium-facilitated disruption of bacterial iron respiration. This elimination of intratumor microbiota impedes the activation of tumoral Toll-like receptors, thus reducing immunosuppressive PD-L1 and interleukin-1β expression by tumor cells, diminishing immunotolerant myeloid populations, and improving the infiltration of cytotoxic T lymphocytes in tumors. Moreover, LGG@Ga-poly hampers pancreatic tumor growth in both preventive and therapeutic contexts, and amplifies the antitumor efficacy of immune checkpoint blockade in preclinical cancer models in female mice. Overall, we offer evidence that thoughtfully designed biomaterials targeting intratumor microbiota can efficaciously augment immunotherapy for the challenging pancreatic cancer.

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

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

Type I conventional dendritic cells facilitate immunotherapy in pancreatic cancer

Inflammation and tissue damage associated with pancreatitis can precede or occur concurrently with pancreatic ductal adenocarcinoma (PDAC). We demonstrate that in PDAC coupled with pancreatitis (ptPDAC), antigen-presenting type I conventional dendritic cells (cDC1s) are specifically activated. Immune checkpoint blockade therapy (iCBT) leads to cytotoxic CD8+ T cell activation and elimination of ptPDAC with restoration of life span even upon PDAC rechallenge. Using PDAC antigen-loaded cDC1s as a vaccine, immunotherapy-resistant PDAC was rendered sensitive to iCBT with elimination of tumors. cDC1 vaccination coupled with iCBT identified specific CDR3 sequences in the tumor-infiltrating CD8+ T cells with potential therapeutic importance. This study identifies a fundamental difference in the immune microenvironment in PDAC concurrent with, or without, pancreatitis and provides a rationale for combining cDC1 vaccination with iCBT as a potential treatment option.

Potential therapeutic targets in myeloid cell therapy for overcoming chemoresistance and immune suppression in gastrointestinal tumors

In the tumor microenvironment (TME), myeloid cells play a pivotal role. Myeloid-derived immunosuppressive cells, including tumor-associated macrophages (TAMs) and myeloid-derived suppressor cells (MDSCs), are central components in shaping the immunosuppressive milieu of the tumor. Within the TME, a majority of TAMs assume an M2 phenotype, characterized by their pro-tumoral activity. These cells promote tumor cell growth, angiogenesis, invasion, and migration. In contrast, M1 macrophages, under appropriate activation conditions, exhibit cytotoxic capabilities against cancer cells. However, an excessive M1 response may lead to pro-tumoral inflammation. As a result, myeloid cells have emerged as crucial targets in cancer therapy. This review concentrates on gastrointestinal tumors, detailing methods for targeting macrophages to enhance tumor radiotherapy and immunotherapy sensitivity. We specifically delve into monocytes and tumor-associated macrophages' various functions, establishing an immunosuppressive microenvironment, promoting tumorigenic inflammation, and fostering neovascularization and stromal remodeling. Additionally, we examine combination therapeutic strategies.

The role of the microscopic world: Exploring the role and potential of intratumoral microbiota in cancer immunotherapy

Microorganisms, including bacteria, viruses, and fungi, coexist in the human body, forming a symbiotic microbiota that plays a vital role in human health and disease. Intratumoral microbial components have been discovered in various tumor tissues and are closely linked to the occurrence, progression, and treatment results of cancer. The intratumoral microbiota can enhance antitumor immunity through mechanisms such as activating the stimulator of interferon genes signaling pathway, stimulating T and NK cells, promoting the formation of TLS, and facilitating antigen presentation. Conversely, the intratumoral microbiota might suppress antitumor immune responses by increasing reactive oxygen species levels, creating an anti-inflammatory environment, inducing T cell inactivation, and enhancing immune suppression, thereby promoting cancer progression. The impact of intratumoral microbiota on antitumor immunity varies based on microbial composition, interactions with cancer cells, and the cancer's current state. A deep understanding of the complex interactions between intratumoral microbiota and antitumor immunity holds the potential to bring new therapeutic strategies and targets to cancer immunotherapy.

Myeloid-derived suppressor cells from tumour-bearing mice induce the population expansion of CD19hiFcγRIIbhi regulatory B cells via PD-L1

Myeloid-derived suppressor cells (MDSCs) increase in number and gain immunosuppressive functions in tumours and many other pathological conditions. MDSCs are characterized by their strong T-cell immunosuppressive capacity. The effects that MDSCs may have on B cells, especially within the tumour microenvironment, are less well understood. Here, we report that either monocytic MDSCs or polymorphonuclear MDSCs can promote increases in interleukin (IL)-10-expressing CD19hiFcγRIIbhi regulatory B cells in vitro and in vivo. Splenic transitional-1, -2, and -3 cells and marginal zone B cells, but not follicular B cells, differentiate into IL-10-expressing CD19hiFcγRIIbhi regulatory B cells. The adoptive transfer of CD19hiFcγRIIbhi regulatory B cells via tail vein injection can promote subcutaneous 3LL tumour growth in mice. The expression of programmed death-ligand 1 on MDSCs was found to be strongly associated with CD19hiFcγRIIbhi regulatory B cell population expansion. Furthermore, the frequency of circulating CD19+FcγRIIhi regulatory B cells was significantly increased in advanced-stage lung cancer patients. Our results unveil a critical role of MDSCs in regulatory B-cell differentiation and population expansion in lung cancer patients.

Gap junction beta-4 accelerates cell cycle progression and metastasis through MET-AKT activation in pancreatic cancer

Despite continuing advances in the development of effective new therapies, including immunotherapies, the prognosis of pancreatic cancer remains extremely poor. Gap junction proteins have become attractive targets for potential cancer therapy. However, the role of gap junction beta-4 (GJB4) protein remains unexplored in pancreatic cancer. Through bioinformatic analyses we discovered pancreatic cancer tissues showed higher levels of GJB4 transcripts compared to normal pancreatic tissues and this had a negative effect on overall survival in patients that had pancreatic cancer. The high expression of nuclear GJB4 was identified as a negative prognostic factor in such patients. Knockdown of GJB4 in cultured pancreatic cancer cells resulted in G0/G1 arrest followed by decreased cell proliferation and suppression of metastatic potential. The overexpression of GJB4 accelerated cell proliferation, migration, and invasion in a SUIT-2 cell line, whereas MET inhibitor canceled the acceleration. GJB4 suppression with siRNA significantly inhibited tumor growth in a mouse xenograft model. Mechanistically, suppression of GJB4 inhibited MET-AKT activities. Such data suggest that targeting the GJB4-MET axis could represent a promising new therapeutic strategy for pancreatic cancer.

Nanodrug-bacteria conjugates-mediated oncogenic collagen depletion enhances immune checkpoint blockade therapy against pancreatic cancer

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) cancer cells specifically produce abnormal oncogenic collagen to bind with integrin α3β1 receptor and activate the downstream focal adhesion kinase (FAK), protein kinase B (AKT), and mitogen-activated protein kinase (MAPK) signaling pathway. Collectively, this promotes immunosuppression and tumor proliferation and restricts the response rate of clinical cancer immunotherapies.

METHODS

Here, by leveraging the hypoxia tropism and excellent motility of the probiotic Escherichia coli strain Nissle 1917 (ECN), we developed nanodrug-bacteria conjugates to penetrate the extracellular matrix (ECM) and shuttle the surface-conjugated protein cages composed of collagenases and anti-programmed death-ligand 1 (PD-L1) antibodies to PDAC tumor parenchyma.

FINDINGS

We found the oncogenic collagen expression in human pancreatic cancer patients and demonstrated its interaction with integrin α3β1. We proved that reactive oxygen species (ROS) in the microenvironment of PDAC triggered collagenase release to degrade oncogenic collagen and block integrin α3β1-FAK signaling pathway, thus overcoming the immunosuppression and synergizing with anti-PD-L1 immunotherapy.

CONCLUSIONS

Collectively, our study highlights the significance of oncogenic collagen in PDAC immunotherapy, and consequently, we developed a therapeutic strategy that can deplete oncogenic collagen to synergize with immune checkpoint blockade for enhanced PDAC treatment efficacy.

FUNDING

This work was supported by the University of Wisconsin Carbone Cancer Center Research Collaborative and Pancreas Cancer Research Task Force, UWCCC Transdisciplinary Cancer Immunology-Immunotherapy Pilot Project, and the start-up package from the University of Wisconsin-Madison (to Q.H.).

The emerging tumor microbe microenvironment: From delineation to multidisciplinary approach-based interventions

Intratumoral microbiota has become research hotspots, and emerges as a non-negligent new component of tumor microenvironments (TME), due to its powerful influence on tumor initiation, metastasis, immunosurveillance and prognosis despite in low-biomass. The accumulations of microbes, and their related components and metabolites within tumor tissues, endow TME with additional pluralistic features which are distinct from the conventional one. Therefore, it's definitely necessary to comprehensively delineate the sophisticated landscapes of tumor microbe microenvironment, as well as their functions and related underlying mechanisms. Herein, in this review, we focused on the fields of tumor microbe microenvironment, including the heterogeneity of intratumor microbiota in different types of tumors, the controversial roles of intratumoral microbiota, the basic features of tumor microbe microenvironment (i.e., pathogen-associated molecular patterns (PAMPs), typical microbial metabolites, autophagy, inflammation, multi-faceted immunomodulation and chemoresistance), as well as the multidisciplinary approach-based intervention of tumor microbiome for cancer therapy by applying wild-type or engineered live microbes, microbiota metabolites, antibiotics, synthetic biology and rationally designed biomaterials. We hope our work will provide valuable insight to deeply understand the interplay of cancer-immune-microbial, and facilitate the development of microbes-based tumor-specific treatments.

Long-term activation of anti-tumor immunity in pancreatic cancer by a p53-expressing telomerase-specific oncolytic adenovirus

BACKGROUND

Pancreatic cancer is an aggressive, immunologically "cold" tumor. Oncolytic virotherapy is a promising treatment to overcome this problem. We developed a telomerase-specific oncolytic adenovirus armed with p53 gene (OBP-702).

METHODS

We investigated the efficacy of OBP-702 for pancreatic cancer, focusing on its long-term effects via long-lived memory CD8 + T cells including tissue-resident memory T cells (TRMs) and effector memory T cells (TEMs) differentiated from effector memory precursor cells (TEMps).

RESULTS

First, in vitro, OBP-702 significantly induced adenosine triphosphate (ATP), which is important for memory T cell establishment. Next, in vivo, OBP-702 local treatment to murine pancreatic PAN02 tumors increased TEMps via ATP induction from tumors and IL-15Rα induction from macrophages, leading to TRM and TEM induction. Activation of these memory T cells by OBP-702 was also maintained in combination with gemcitabine+nab-paclitaxel (GN) in a PAN02 bilateral tumor model, and GN + OBP-702 showed significant anti-tumor effects and increased TRMs in OBP-702-uninjected tumors. Finally, in a neoadjuvant model, in which PAN02 cells were re-inoculated after resection of treated-PAN02 tumors, GN + OBP-702 provided long-term anti-tumor effects even after tumor resection.

CONCLUSION

OBP-702 can be a long-term immunostimulant with sustained anti-tumor effects on immunologically cold pancreatic cancer.

Concurrent targeting of GSK3 and MEK as a therapeutic strategy to treat pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies worldwide. However, drug discovery for PDAC treatment has proven complicated, leading to stagnant therapeutic outcomes. Here, we identify Glycogen synthase kinase 3 (GSK3) as a therapeutic target through a whole-body genetic screening utilizing a '4-hit' Drosophila model mimicking the PDAC genotype. Reducing the gene dosage of GSK3 in a whole-body manner or knocking down GSK3 specifically in transformed cells suppressed 4-hit fly lethality, similar to Mitogen-activated protein kinase kinase (MEK), the therapeutic target in PDAC we have recently reported. Consistently, a combination of the GSK3 inhibitor CHIR99021 and the MEK inhibitor trametinib suppressed the phosphorylation of Polo-like kinase 1 (PLK1) as well as the growth of orthotopic human PDAC xenografts in mice. Additionally, reducing PLK1 genetically in 4-hit flies rescued their lethality. Our results reveal a therapeutic vulnerability in PDAC that offers a treatment opportunity for patients by inhibiting multiple targets.

Unveiling the immunosuppressive landscape of pancreatic ductal adenocarcinoma: implications for innovative immunotherapy strategies

Pancreatic cancer, particularly pancreatic ductal adenocarcinoma (PDAC), stands as the fourth leading cause of cancer-related deaths in the United States, marked by challenging treatment and dismal prognoses. As immunotherapy emerges as a promising avenue for mitigating PDAC's malignant progression, a comprehensive understanding of the tumor's immunosuppressive characteristics becomes imperative. This paper systematically delves into the intricate immunosuppressive network within PDAC, spotlighting the significant crosstalk between immunosuppressive cells and factors in the hypoxic acidic pancreatic tumor microenvironment. By elucidating these mechanisms, we aim to provide insights into potential immunotherapy strategies and treatment targets, laying the groundwork for future studies on PDAC immunosuppression. Recognizing the profound impact of immunosuppression on PDAC invasion and metastasis, this discussion aims to catalyze the development of more effective and targeted immunotherapies for PDAC patients.

An investigation for phylogenetic characterization of human Pancreatic cancer microbiome by 16SrDNA Sequencing and Bioinformatics techniques

Pancreatic cancer is a significant public health concern, with increasing incidence rates and limited treatment options. Recent studies have highlighted the role of the human microbiome, particularly the gut microbiota, in the development and progression of this disease. Microbial dysbiosis, characterized by alterations in the composition and function of the gut microbiota, has been implicated in pancreatic carcinogenesis through mechanisms involving chronic inflammation, immune dysregulation, and metabolic disturbances. Researchers have identified specific microbial signatures associated with pancreatic cancer, offering potential biomarkers for early detection and prognostication. By leveraging advanced sequencing and bioinformatics tools, scientists have delineated differences in the gut microbiota between pancreatic cancer patients and healthy individuals, providing insights into disease pathogenesis and potential diagnostic strategies. Moreover, the microbiome holds promise as a therapeutic target in pancreatic cancer treatment. Interventions aimed at modulating the microbiome, such as probiotics, prebiotics, and fecal microbiota transplantation, have demonstrated potential in enhancing the efficacy of existing cancer therapies, including chemotherapy and immunotherapy. These approaches can influence immune responses, alter tumor microenvironments, and sensitize tumors to treatment, offering new avenues for improving patient outcomes and overcoming therapeutic resistance. Overall, understanding the complex interplay between the microbiome and pancreatic cancer is crucial for advancing our knowledge of disease mechanisms and identifying innovative therapeutic strategies. Here we report phylogenetic analysis of the 16S microbial sequences of the pancreatic cancer mice microbiome and corresponding age matched healthy mice microbiome. We successfully identified differentially abundance of microbiota in the pancreatic cancer.

Mitochondrial energy metabolism-related gene signature as a prognostic indicator for pancreatic adenocarcinoma

Background: Pancreatic adenocarcinoma (PAAD) is a highly malignant gastrointestinal tumor and is associated with an unfavorable prognosis worldwide. Considering the effect of mitochondrial metabolism on the prognosis of pancreatic cancer has rarely been investigated, we aimed to establish prognostic gene markers associated with mitochondrial energy metabolism for the prediction of survival probability in patients with PAAD. Methods: Gene expression data were obtained from The Cancer Genome Atlas and Gene Expression Omnibus databases, and the mitochondrial energy metabolism-related genes were obtained from the GeneCards database. Based on mitochondrial energy metabolism score (MMs), differentially expressed MMRGs were established for MMs-high and MMs-low groups using ssGSEA. After the univariate Cox and least absolute and selection operator (LASSO) analyses, a prognostic MMRG signature was used in the multivariate Cox proportional regression model. Survival and immune cell infiltration analyses were performed. In addition, a nomogram based on the risk model was used to predict the survival probability of patients with PAAD. Finally, the expression of key genes was verified using quantitative polymerase chain reaction and immunohistochemical staining. Intro cell experiments were performed to evaluated the proliferation and invasion of pancreatic cancer cells. Results: A prognostic signature was constructed consisting of two mitochondrial energy metabolism-related genes (MMP11, COL10A1). Calibration and receiver operating characteristic (ROC) curves verified the good predictability performance of the risk model for the survival rate of patients with PAAD. Finally, immune-related analysis explained the differences in immune status between the two subgroups based on the risk model. The high-risk score group showed higher estimate, immune, and stromal scores, expression of eight checkpoint genes, and infiltration of M0 macrophages, which might indicate a beneficial response to immunotherapy. The qPCR results confirmed high expression of MMP11 in pancreatic cancer cell lines, and IHC also verified high expression of MMP11 in clinical pancreatic ductal adenocarcinoma tissues. In vitro cell experiments also demonstrated the role of MMP11 in cell proliferation and invasion. Conclusion: Our study provides a novel two-prognostic gene signature-based on MMRGs-that accurately predicted the survival of patients with PAAD and could be used for mitochondrial energy metabolism-related therapies in the future.

Ultrahigh Enzyme Loading Metal-Organic Frameworks for Deep Tissue Pancreatic Cancer Photoimmunotherapy

Protein drugs hold promise in treating multiple complex diseases, including cancer. The priority of protein drug application is precise delivery of substantial bioactive protein into tumor site. Metal-organic-framework (MOF) is widely considered as a promising carrier to encapsulate protein drug owing to the noncovalent interaction between carrier and protein. However, limited loading efficiency and potential toxicity of metal ion in MOF restrict its application in clinical research. Herein, a tumor targeted collagenase-encapsulating MOF via protein-metal ion-organic ligand coordination (PMOCol ) for refining deep tissue pancreatic cancer photoimmunotherapy is developed. By an expedient method in which the ratio of metal ion, histidine residues of protein and ligand is precisely controlled, PMOCol is constructed with ultrahigh encapsulation efficiency (80.3 wt%) and can release collagenase with high enzymatic activity for tumor extracellular matrix (ECM) regulation after reaching tumor microenvironment (TME). Moreover, PMOcol exhibits intensively poorer toxicity than the zeolitic imidazolate framework-8 biomineralized protein. After treatment, the pancreatic tumor with abundant ECM shows enhanced immunocyte infiltration owing to extracellular matrix degradation that improves suppressive TME. By integrating hyperthermia agent with strong near-infrared absorption (1064 nm), PMOCol can induce acute immunogenicity to host immunity activation and systemic immune memory production to prevent tumor development and recurrence.

Intratumoural microbiota: a new frontier in cancer development and therapy

Human microorganisms, including bacteria, fungi, and viruses, play key roles in several physiological and pathological processes. Some studies discovered that tumour tissues once considered sterile actually host a variety of microorganisms, which have been confirmed to be closely related to oncogenesis. The concept of intratumoural microbiota was subsequently proposed. Microbiota could colonise tumour tissues through mucosal destruction, adjacent tissue migration, and hematogenic invasion and affect the biological behaviour of tumours as an important part of the tumour microenvironment. Mechanistic studies have demonstrated that intratumoural microbiota potentially promote the initiation and progression of tumours by inducing genomic instability and mutations, affecting epigenetic modifications, promoting inflammation response, avoiding immune destruction, regulating metabolism, and activating invasion and metastasis. Since more comprehensive and profound insights about intratumoral microbiota are continuously emerging, new methods for the early diagnosis and prognostic assessment of cancer patients have been under examination. In addition, interventions based on intratumoural microbiota show great potential to open a new chapter in antitumour therapy, especially immunotherapy, although there are some inevitable challenges. Here, we aim to provide an extensive review of the concept, development history, potential sources, heterogeneity, and carcinogenic mechanisms of intratumoural microorganisms, explore the potential role of microorganisms in tumour prognosis, and discuss current antitumour treatment regimens that target intratumoural microorganisms and the research prospects and limitations in this field.

Bioinformatics-based analysis of the relationship between disulfidptosis and prognosis and treatment response in pancreatic cancer

Tumor formation is closely associated with disulfidptosis, a new form of cell death induced by disulfide stress-induced. The exact mechanism of action of disulfidptosis in pancreatic cancer (PCa) is not clear. This study analyzed the impact of disulfidptosis-related genes (DRGs) on the prognosis of PCa and identified clusters of DRGs, and based on this, a risk score (RS) signature was developed to assess the impact of RS on the prognosis, immune and chemotherapeutic response of PCa patients. Based on transcriptomic data and clinical information from PCa tissue and normal pancreatic tissue samples obtained from the TCGA and GTEx databases, differentially expressed and differentially surviving DRGs in PCa were identified from among 15 DRGs. Two DRGs clusters were identified by consensus clustering by merging the PCa samples in the GSE183795 dataset. Analysis of DRGs clusters about the PCa tumor microenvironment and differential analysis to obtain differential genes between the two DRG clusters. Patients were then randomized into the training and testing sets, and a prognostic prediction signature associated with disulfidptosis was constructed in the training set. Then all samples were divided into high-disulfidptosis-risk (HDR) and low-disulfidptosis-risk (LDR) subgroups based on the RS calculated from the signature. The predictive efficacy of the signature was assessed by survival analysis, nomograms, correlation analysis of clinicopathological characteristics, and the receiver operating characteristic (ROC) curves. To assess differences between different risk subgroups in immune cell infiltration, expression of immune checkpoint molecules, somatic gene mutations, and effectiveness of immunotherapy and chemotherapy. The GSE57495 dataset was used as external validation, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression levels of DRGs. A total of 12 DRGs with differential expression and prognosis in PCa were identified, based on which a risk-prognosis signature containing five differentially expressed genes (DEGs) was developed. The signature was a good predictor and an independent risk factor. The nomogram and calibration curve shows the signature's excellent clinical applicability. Functional enrichment analysis showed that RS was associated with tumor and immune-related pathways. RS was strongly associated with the tumor microenvironment, and analysis of response to immunotherapy and chemotherapy suggests that the signature can be used to assess the sensitivity of treatments. External validation further demonstrated the model's efficacy in predicting the prognosis of PCa patients, with RT-qPCR and immunohistochemical maps visualizing the expression of each gene in PCa cell lines and the tissue. Our study is the first to apply the subtyping model of disulfidptosis to PCa and construct a signature based on the disulfidptosis subtype, which can provide an accurate assessment of prognosis, immunotherapy, and chemotherapy response in PCa patients, providing new targets and directions for the prognosis and treatment of PCa.

Pro-tumor Tfh2 cells induce detrimental IgG4 production and PGE2-dependent IgE inhibition in pancreatic cancer

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) has a dismal prognosis and it is characterized by predominant pro-tumor Th2-type inflammation. T follicular helper (Tfh) cells are relevant immunoregulators in cancer, and often correlate with better survival. How the Th2-skewed microenvironment in PDAC modulates the differentiation of Tfh cells and their immunoregulatory function is unknown.

METHODS

We carried out high-dimensional flow cytometry and T-cell receptor- and RNA-sequencing, as well as bioinformatics, immunohistochemistry and in vitro mechanistic studies.

FINDINGS

We identified Tfh1-, Tfh2-, and Tfh17-like cell clusters in the blood, tumors and tumor-draining lymph-nodes (TDLNs) of chemo-naïve PDAC patients and showed that high percentages of Tfh2 cells within the tumor tissue and TDLNs correlated with reduced patient survival. Moreover, only Tfh2 cells were highly activated and were reduced in frequency in patients who responded to neoadjuvant chemotherapy. RNA-sequencing analysis of immunoglobulin expression showed that tumor and TDLN samples expressed all immunoglobulin (IGH) isotypes apart from IGHE. Consistent with these findings, Tfh2 cells differentiated in vitro by tumor microenvironment-conditioned dendritic cells promoted the production of anti-inflammatory IgG4 antibodies by co-cultured B cells, dependent on IL-13. Moreover, unexpectedly, Tfh2 cells inhibited the secretion of pro-inflammatory IgE, dependent on prostaglandin E2.

INTERPRETATION

Our results indicate that in PDAC, highly activated pro-tumor Tfh2 favor anti-inflammatory IgG4 production, while inhibit pro-inflammatory IgE. Thus, targeting the circuits that drive Tfh2 cells, in combination with chemotherapy, may re-establish beneficial anti-tumor Tfh-B cell interactions and facilitate more effective treatment.

FUNDING

Research grants from the Italian Association for Cancer Research (AIRC) IG-19119 to MPP and the AIRC Special Program in Metastatic disease: the key unmet need in oncology, 5 per Mille no. 22737 to CB, MF, CD, MR and MPP; the ERA-NET EuroNanoMed III (a collaborative european grant financed by the Italian Ministry of Health, Italy) project PANIPAC (JTC2018/041) to MPP; the Fondazione Valsecchi to SC.

Single-cell RNA-seq reveals characteristics in tumor microenvironment of PDAC with MSI-H following neoadjuvant chemotherapy with anti-PD-1 therapy

Accumulating evidence suggests the minority of patients with advanced pancreatic ductal adenocarcinoma (PDAC) that have microsatellite instability high (MSI-H) can benefit from immune checkpoint inhibitors (ICIs). However, the effects of ICIs on the tumor microenvironment (TME) of PDAC remain elusive. We conducted single-cell RNA-seq (scRNA-seq) analysis on a residual lesion from a MSI-H PDAC patient who received a radical operation after eight cycles of neoadjuvant treatment (nab-paclitaxel/gemcitabine plus pembrolizumab). Multiple tumor subclusters were identified in residual lesion after neoadjuvant treatment, one of which was mainly composed of cells in the S and G2M phases. This subcluster also had enriched expression of MKI67 and PCNA and cell cycle-related signatures and was thus defined as a proliferating tumor subcluster. This subcluster had higher S_score, Fatty acid_score, UPR_score, and Glycolysis_score than others. We also identified characteristics of the TME after neoadjuvant treatment by comparing the excised primary tumors form nontreated PDAC and the residual lesion. The residual lesion was characterized with activated pancreatic stellate cells (PSCs) and exhausted T cells (Tex). We compared the receptor-ligand interactions between the two groups, and found that no checkpoint receptor-ligand pairs between T cells and tumor cells were identified in the residual lesion, while there were many checkpoint receptor-ligand pairs in the nontreated primary PDAC. In conclusion, our findings revealed the characteristics of residual lesion of advanced PDAC with MSI-H upon combination treatment of chemotherapy and immunotherapy, which might provide some valuable clues for solving the puzzle of ICI in PDAC.

Identification of ONECUT3 as a stemness-related transcription factor regulating NK cell-mediated immune evasion in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) has a dismal response to the current T cell-based immunotherapies, which is attributed to intratumoral heterogeneity caused by PDAC stem cells and lack of major histocompatibility complex class I required for neoantigen presentation. Although this scenario makes natural killer (NK) cells attractive candidates for immunotherapeutic agents targeting MHC-I-deficient cancer stem cells in heterogeneous PDACs, little is known about PDAC stem cell immunology. In our study, PDAC-specific datasets from public databases were collected for in-depth bioinformatic analysis. We found that the abundance of PDAC stemness negatively influenced the infiltration of NK cells and identified the transcription factor ONECUT3 enriched in PDACs with high stemness index scores and Pan-cancer Stemness Signature levels. A series of NK cell-targeted inhibitory immune checkpoints were highly expressed in ONECUT3high PDACs. The patient group with high levels of ONECUT3 expression had a high risk of poor overall survival, even if accompanied by high infiltration of NK cells. Furthermore, the prostanoid metabolic process was enriched in ONECUT3high PDACs with high levels of NK cell-targeted inhibitory immune checkpoints. ONECUT3 enriched in high-stemness PDACs possessed the potential to transcriptionally regulate the prostanoid metabolism-related genes. Our study reveals ONECUT3 as a candidate stemness-related transcription factor regulating NK cell-targeted inhibitory immune checkpoints in PDAC. ONECUT3-mediated prostanoid metabolism may regulate cancer stemness and immune evasion in PDAC. Synergistic inhibition of prostanoid metabolism may improve the efficacy of NK cell-based immunotherapies targeting intratumoral heterogeneity caused by PDAC stem cells.

M6A methylation modification in autoimmune diseases, a promising treatment strategy based on epigenetics

BACKGROUND

N6-methyladenosine (m6A) methylation modification is involved in the regulation of various biological processes, including inflammation, antitumor, and antiviral immunity. However, the role of m6A modification in the pathogenesis of autoimmune diseases has been rarely reported.

METHODS

Based on a description of m6A modification and the corresponding research methods, this review systematically summarizes current insights into the mechanism of m6A methylation modification in autoimmune diseases, especially its contribution to rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE).

RESULTS

By regulating different biological processes, m6A methylation is involved in the pathogenesis of autoimmune diseases and provides a promising biomarker for the diagnosis and treatment of such diseases. Notably, m6A methylation modification is involved in regulating a variety of immune cells and mitochondrial energy metabolism. In addition, m6A methylation modification plays a role in the pathological processes of RA, and m6A methylation-related genes can be used as potential targets in RA therapy.

CONCLUSIONS

M6A methylation modification plays an important role in autoimmune pathological processes such as RA and SLE and represents a promising new target for clinical diagnosis and treatment, providing new ideas for the treatment of autoimmune diseases by targeting m6A modification-related pathways.

Farnesoid X receptor activation inhibits pancreatic carcinogenesis

Farnesoid X receptor (FXR), a member of the nuclear receptor superfamily that controls bile acid (BA) homeostasis, has also been proposed as a tumor suppressor for breast and liver cancer. However, its role in pancreatic ductal adenocarcinoma (PDAC) tumorigenesis remains controversial. We recently found that FXR attenuates acinar cell autophagy in chronic pancreatitis resulting in reduced autophagy and promotion of pancreatic carcinogenesis. Feeding Kras-p48-Cre (KC) mice with the BA chenodeoxycholic acid (CDCA), an FXR agonist, attenuated pancreatic intraepithelial neoplasia (PanIN) progression, reduced cell proliferation, neoplastic cells and autophagic activity, and increased acinar cells, elevated pro-inflammatory cytokines and chemokines, with a compensatory increase in the anti-inflammatory response. Surprisingly, FXR-deficient KC mice did not show any response to CDCA, suggesting that CDCA attenuates PanIN progression and decelerate tumorigenesis in KC mice through activating pancreatic FXR. FXR is activated in pancreatic cancer cell lines in response to CDCA in vitro. FXR levels were highly increased in adjuvant and neoadjuvant PDAC tissue compared to healthy pancreatic tissue, indicating that FXR is expressed and potentially activated in human PDAC. These results suggest that BA exposure activates inflammation and suppresses autophagy in KC mice, resulting in reduced PanIN lesion progression. These data suggest that activation of pancreatic FXR has a protective role by reducing the growth of pre-cancerous PDAC lesions in response to CDCA and possibly other FXR agonists.

KRAS inhibition activates an actionable CD24 'don't eat me' signal in pancreas cancer

KRAS G12C inhibitor (G12Ci) has produced encouraging, albeit modest and transient, clinical benefit in pancreatic ductal adenocarcinoma (PDAC). Identifying and targeting resistance mechanisms to G12Ci treatment is therefore crucial. To better understand the tumor biology of the KRAS G12C allele and possible bypass mechanisms, we developed a novel autochthonous KRAS G12C -driven PDAC model. Compared to the classical KRAS G12D PDAC model, the G12C model exhibit slower tumor growth, yet similar histopathological and molecular features. Aligned with clinical experience, G12Ci treatment of KRAS G12C tumors produced modest impact despite stimulating a 'hot' tumor immune microenvironment. Immunoprofiling revealed that CD24, a 'do-not-eat-me' signal, is significantly upregulated on cancer cells upon G12Ci treatment. Blocking CD24 enhanced macrophage phagocytosis of cancer cells and significantly sensitized tumors to G12Ci treatment. Similar findings were observed in KRAS G12D -driven PDAC. Our study reveals common and distinct oncogenic KRAS allele-specific biology and identifies a clinically actionable adaptive mechanism that may improve the efficacy of oncogenic KRAS inhibitor therapy in PDAC.

Significance

Lack of faithful preclinical models limits the exploration of resistance mechanisms to KRAS G12C inhibitor in PDAC. We generated an autochthonous KRAS G12C -driven PDAC model, which revealed allele-specific biology of the KRAS G12C during PDAC development. We identified CD24 as an actionable adaptive mechanisms in cancer cells induced upon KRAS G12C inhibition and blocking CD24 sensitizes PDAC to KRAS inhibitors in preclinical models.

The correlation between gut and intra-tumor microbiota and PDAC: Etiology, diagnostics and therapeutics

Pancreatic ductal adenocarcinoma (PDAC) is one of the lethal cancers in the world and its 5-year survival rate is <10%. Due to the unique TME and dense tissue structure, its curative efficacy is far from satisfactory，the immunotherapy is even more invalid. According to the recent studies, the gut and tumor microbiota have been proved to play a key role in the development, progression and prognosis of PDAC. Based on the differences of microbiome composition observed in PDAC patients and normal pancreas, many researches have been made focusing on the latent communication between gut and intra-tumor microbiota and PDAC. In this review, we will demonstrate the potential mechanism of the oncogenic effects of GM and IM and their crucial effects on modulating the TME. Besides, we focus on their interaction with chemotherapeutic and immunotherapeutic drugs and inducing the drug resistance, thus enlightening the promising role to be used to monitor the occurrence of PDAC, accurately modulate the immune environment to promote the therapeutic efficacy and predict the prognosis.

Post-operative mortality and recurrence patterns in pancreatic cancer according to KRAS mutation and CDKN2A, p53, and SMAD4 expression

Alterations in KRAS, CDKN2A (p16), TP53, and SMAD4 genes have been major drivers of pancreatic carcinogenesis. The clinical course of patients with pancreatic cancer in relation to these driver alterations has not been fully characterised in large populations. We hypothesised that pancreatic carcinomas with different combinations of KRAS mutation and aberrant expression of CDKN2A, p53, and SMAD4 might show distinctive recurrence patterns and post-operative survival outcomes. To test this hypothesis, we utilised a multi-institutional cohort of 1,146 resected pancreatic carcinomas and assessed KRAS mutations by droplet digital polymerase chain reaction and CDKN2A, p53, and SMAD4 expression by immunohistochemistry. Multivariable hazard ratios (HRs) and 95% confidence intervals (CIs) for disease-free survival (DFS) and overall survival (OS) were computed according to each molecular alteration and the number of altered genes using the Cox regression models. Multivariable competing risks regression analyses were conducted to assess the associations of the number of altered genes with specific patterns of recurrence. Loss of SMAD4 expression was associated with short DFS (multivariable HR, 1.24; 95% CI, 1.09-1.43) and OS times (multivariable HR, 1.27; 95% CI, 1.10-1.46). Compared to cases with 0-2 altered genes, cases with three and four altered genes had multivariable HRs for OS of 1.28 (95% CI, 1.09-1.51) and 1.47 (95% CI, 1.22-1.78), respectively (ptrend  < 0.001). Patients with an increasing number of altered genes were more likely to have short DFS time (ptrend  = 0.003) and to develop liver metastasis (ptrend  = 0.006) rather than recurrence at local or other distant sites. In conclusion, loss of SMAD4 expression and an increasing number of altered genes were associated with unfavourable outcomes in pancreatic cancer patients. This study suggests that the accumulation of the four major driver alterations can confer a high metastatic potential to the liver, thereby impairing post-operative survival among patients with pancreatic cancer.

Noncoding RNAs as regulators of STAT3 pathway in gastrointestinal cancers: Roles in cancer progression and therapeutic response

Gastrointestinal (GI) tumors (cancers of the esophagus, gastric, liver, pancreas, colon, and rectum) contribute to a large number of deaths worldwide. STAT3 is an oncogenic transcription factor that promotes the transcription of genes associated with proliferation, antiapoptosis, survival, and metastasis. STAT3 is overactivated in many human malignancies including GI tumors which accelerates tumor progression, metastasis, and drug resistance. Research in recent years demonstrated that noncoding RNAs (ncRNAs) play a major role in the regulation of many signaling pathways including the STAT3 pathway. The major types of endogenous ncRNAs that are being extensively studied in oncology are microRNAs, long noncoding RNAs, and circular RNAs. These ncRNAs can either be tumor-promoters or tumor-suppressors and each one of them imparts their activity via different mechanisms. The STAT3 pathway is also tightly modulated by ncRNAs. In this article, we have elaborated on the tumor-promoting role of STAT3 signaling in GI tumors. Subsequently, we have comprehensively discussed the oncogenic as well as tumor suppressor functions and mechanism of action of ncRNAs that are known to modulate STAT3 signaling in GI cancers.

Drosophila Screening Identifies Dual Inhibition of MEK and AURKB as an Effective Therapy for Pancreatic Ductal Adenocarcinoma

Significant progress has been made in understanding the pathogenesis of pancreatic ductal adenocarcinoma (PDAC) by generating and using murine models. To accelerate drug discovery by identifying novel therapeutic targets on a systemic level, here we generated a Drosophila model mimicking the genetic signature in PDAC (KRAS, TP53, CDKN2A, and SMAD4 alterations), which is associated with the worst prognosis in patients. The '4-hit' flies displayed epithelial transformation and decreased survival. Comprehensive genetic screening of their entire kinome revealed kinases including MEK and AURKB as therapeutic targets. Consistently, a combination of the MEK inhibitor trametinib and the AURKB inhibitor BI-831266 suppressed the growth of human PDAC xenografts in mice. In patients with PDAC, the activity of AURKB was associated with poor prognosis. This fly-based platform provides an efficient whole-body approach that complements current methods for identifying therapeutic targets in PDAC.

SIGNIFICANCE

Development of a Drosophila model mimicking genetic alterations in human pancreatic ductal adenocarcinoma provides a tool for genetic screening that identifies MEK and AURKB inhibition as a potential treatment strategy.

A T Cell-Engaging Tumor Organoid Platform for Pancreatic Cancer Immunotherapy

Pancreatic ductal adenocarcinoma (PDA) is a clinically challenging disease with limited treatment options. Despite a small percentage of cases with defective mismatch DNA repair (dMMR), PDA is included in the most immune-resistant cancer types that are poorly responsive to immune checkpoint blockade (ICB) therapy. To facilitate drug discovery combating this immunosuppressive tumor type, a high-throughput drug screen platform is established with the newly developed T cell-incorporated pancreatic tumor organoid model. Tumor-specific T cells are included in the pancreatic tumor organoids by two-step cell packaging, fully recapitulating immune infiltration in the immunosuppressive tumor microenvironment (TME). The organoids are generated with key components in the original tumor, including epithelial, vascular endothelial, fibroblast and macrophage cells, and then packaged with T cells into their outside layer mimicking a physical barrier and enabling T cell infiltration and cytotoxicity studies. In the PDA organoid-based screen, epigenetic inhibitors ITF2357 and I-BET151 are identified, which in combination with anti-PD-1 based therapy show considerably greater anti-tumor effect. The combinatorial treatment turns the TME from immunosuppressive to immunoactive, up-regulates the MHC-I antigen processing and presentation, and enhances the effector T cell activity. The standardized PDA organoid model has shown great promise to accelerate drug discovery for the immunosuppressive cancer.

Stratification of patients with KRAS-mutated advanced non-small cell lung cancer: improving prognostics

INTRODUCTION

KRAS is the most frequently mutated oncogene in cancer and encodes a key signaling protein in tumors. Due to its high affinity for GTP and the lack of a large binding pocket that allosteric inhibitors can occupy, KRAS has long been considered 'non-druggable.' Finding effective treatment measures for patients with KRAS mutations is our top priority.

AREAS COVERED

In this article, we will provide an overview of the KRAS pathway and review the current state of therapeutic strategies for targeting oncogenic KRAS, as well as their potential to improve outcomes in patients with KRAS-mutant malignancies. We will also discuss the development of these strategies and gave an outlook on prospects.

EXPERT OPINION

KRAS mutations have posed a significant challenge in the treatment of advanced non-small cell lung cancer (NSCLC) over the past few decades. However, the emergence of immunotherapy and KRAS inhibitors, such as Sotorasib (AMG 510) and Adagrasib (MRTX849), has marked a new era in cancer therapy. As more research and clinical trials continue, we anticipate the development of more effective treatment strategies and better options for lung cancer patients.

Immunotherapies in non-metastatic gastrointestinal cancers

PURPOSE

Over the last decade, immune checkpoint inhibitors (ICI) have emerged as cornerstone in the treatment of many metastatic tumour types, including gastrointestinal cancers. In many solid tumours, the effective therapies in the metastatic field are progressively brought into the curative setting. Consequently, earlier tumoural settings have become a field of experiment for immunotherapies. In melanoma, lung, and bladder cancers, excellent results were recorded, possibly explained by differences in the tumour microenvironment between metastatic and non-metastatic settings. In gastrointestinal (GI) Oncology, nivolumab is the first immune checkpoint inhibitor to become a standard-of-care adjuvant treatment after curative surgery for oesophagal or gastroesophageal junction cancer.

RECENT FINDINGS

We herein discuss the results of a selection of the most relevant studies presented/published over the last 18 months testing immunotherapies in non-metastatic GI cancers. Among immunotherapies, ICI have been investigated in pre-, peri- and postoperative setting across tumour types, alone or in combination with chemo- and/or radiotherapy. Vaccines are also a new field of investigation.

SUMMARY

Promising results from two studies (NCT04165772 and NICHE-2 study) demonstrating never-seen-before responses to neoadjuvant immunotherapy in MMR deficient (dMMR) colorectal cancers raise hope for improving the patients' outcome and developing organ-sparing strategies in this situation.

Vitamin E in the management of pancreatic cancer: A scoping review

Pancreatic cancer is the leading cause of cancer mortality worldwide. Research investigating effective management strategies for pancreatic cancer is ongoing. Vitamin E, consisting of both tocopherol and tocotrienol, has demonstrated debatable effects on pancreatic cancer cells. Therefore, this scoping review aims to summarize the effects of vitamin E on pancreatic cancer. In October 2022, a literature search was conducted using PubMed and Scopus since their inception. Original studies on the effects of vitamin E on pancreatic cancer, including cell cultures, animal models and human clinical trials, were considered for this review. The literature search found 75 articles on this topic, but only 24 articles met the inclusion criteria. The available evidence showed that vitamin E modulated proliferation, cell death, angiogenesis, metastasis and inflammation in pancreatic cancer cells. However, the safety and bioavailability concerns remain to be answered with more extensive preclinical and clinical studies. More in-depth analysis is necessary to investigate further the role of vitamin E in the management of pancreatic cancers.

Long noncoding RNA CASC9 promotes pancreatic cancer progression by acting as a ceRNA of miR-497-5p to upregulate expression of CCND1

BACKGROUND

Pancreatic cancer (PC) is an aggressive malignancy with poor prognosis. Accumulating studies have showed that long non-coding RNA (lncRNA) is a crucial regulator in various tumorigenesis and progression including PC. This research aims to explore the roles and molecular mechanism of lncRNA cancer susceptibility candidate 9 (CASC9) in PC.

METHODS

The expression levels of lncRNA CASC9 and miR-497-5p were evaluated in PC tissues and paired adjacent healthy tissues by quantitative real-time PCR. PC cell lines were transfected with lentivirus targeting lncRNA CASC9, and cells proliferation, migration and invasion tests were conducted. Dual luciferase reporter assays were also carried out to explore the relationship between lncRNA CASC9, miR-497-5p and Cyclin D1 (CCND1).

RESULTS

LncRNA CASC9 was significantly up-regulated in PC tissues, while miR-497-5p expression was down-regulated. Down-regulation of lncRNA CASC9 in PC cells can significantly suppress the cell aggressiveness both in vitro and in vivo; moreover, knock-down of miR-497-5p could neutralize this impact. Additionally, the luciferase activity assay has assured that CCND1 was a downstream target of miR-497-5p.

CONCLUSION

LncRNA CASC9 can promote the PC progression by modulating miR-497-5p/CCND1 axis, which is potential target for PC treatment.

Targeting the metabolism and immune system in pancreatic ductal adenocarcinoma: Insights and future directions

Pancreatic cancer, specifically pancreatic ductal adenocarcinoma (PDAC), presents a challenging landscape due to its complex nature and the highly immunosuppressive tumor microenvironment (TME). This immunosuppression severely limits the effectiveness of immune-based therapies. Studies have revealed the critical role of immunometabolism in shaping the TME and influencing PDAC progression. Genetic alterations, lysosomal dysfunction, gut microbiome dysbiosis, and altered metabolic pathways have been shown to modulate immunometabolism in PDAC. These metabolic alterations can significantly impact immune cell functions, including T-cells, myeloid-derived suppressor cells (MDSCs), and macrophages, evading anti-tumor immunity. Advances in immunotherapy offer promising avenues for overcoming immunosuppressive TME and enhancing patient outcomes. This review highlights the challenges and opportunities for future research in this evolving field. By exploring the connections between immunometabolism, genetic alterations, and the microbiome in PDAC, it is possible to tailor novel approaches capable of improving immunotherapy outcomes and addressing the limitations posed by immunosuppressive TME. Ultimately, these insights may pave the way for improved treatment options and better outcomes for PDAC patients.