Pancreatic cancer intrinsic PI3Kα activity accelerates metastasis and rewires macrophage component

Detailed role of SR-A1 and SR-E3 in tumor biology, progression, and therapy

The first host defense systems are the innate immune response and the inflammatory response. Among innate immune cells, macrophages, are crucial because they preserve tissue homeostasis and eradicate infections by phagocytosis, or the ingestion of particles. Macrophages exhibit phenotypic variability contingent on their stimulation state and tissue environment and may be detected in several tissues. Meanwhile, critical inflammatory functions are played by macrophage scavenger receptors, in particular, SR-A1 (CD204) and SR-E3 (CD206), in a variety of pathophysiologic events. Such receptors, which are mainly found on the surface of multiple types of macrophages, have different effects on processes, including atherosclerosis, innate and adaptive immunity, liver and lung diseases, and, more recently, cancer. Although macrophage scavenger receptors have been demonstrated to be active across the disease spectrum, conflicting experimental findings and insufficient signaling pathways have hindered our comprehension of the molecular processes underlying its array of roles. Herein, as SR-A1 and SR-E3 functions are often binary, either protecting the host or impairing the pathophysiology of cancers has been reviewed. We will look into their function in malignancies, with an emphasis on their recently discovered function in macrophages and the possible therapeutic benefits of SR-A1 and SR-E3 targeting.

FAM53B promotes pancreatic ductal adenocarcinoma metastasis by regulating macrophage M2 polarization

BACKGROUND

Our study investigated the role of FAM53B in regulating macrophage M2 polarization and its potential mechanisms in promoting pancreatic ductal adenocarcinoma (PDAC) metastasis.

AIM

To further investigate the role of FAM53B in regulating macrophage M2 polarization and its potential mechanism in promoting PDAC metastasis. Our goal is to determine how FAM53B affects macrophage M2 polarization and to define its underlying mechanism in PDAC metastasis.

METHODS

Cell culture and various experiments, including protein analysis, immunohistochemistry, and animal model experiments, were conducted. We compared FAM53B expression between PDAC tissues and healthy tissues and assessed the correlation of FAM53B expression with clinical features. Our study analyzed the role of FAM53B in macrophage M2 polarization in vitro by examining the expression of relevant markers. Finally, we used a murine model to study the role of FAM53B in PDAC metastasis and analyzed the potential underlying mechanisms.

RESULTS

Our research showed that there was a significant increase in FAM53B levels in PDAC tissues, which was linked to adverse tumor features. Experimental findings indicated that FAM53B can enhance macrophage M2 polarization, leading to increased anti-inflammatory factor release. The results from the mouse model further supported the role of FAM53B in PDAC metastasis, as blocking FAM53B prevented tumor cell invasion and metastasis.

CONCLUSION

FAM53B promotes PDAC metastasis by regulating macrophage M2 polarization. This discovery could lead to the development of new strategies for treating PDAC. For example, interfering with the FAM53B signaling pathway may prevent cancer spread. Our research findings also provide important information for expanding our understanding of PDAC pathogenesis.

Clinical and Preclinical Targeting of Oncogenic Pathways in PDAC: Targeted Therapeutic Approaches for the Deadliest Cancer

Pancreatic ductal adenocarcinoma (PDAC) is one of the leading causes of cancer-related death worldwide. It is commonly diagnosed in advanced stages and therapeutic interventions are typically constrained to systemic chemotherapy, which yields only modest clinical outcomes. In this review, we examine recent developments in targeted therapy tailored to address distinct molecular pathway alteration required for PDAC. Our review delineates the principal signaling pathways and molecular mechanisms implicated in the initiation and progression of PDAC. Subsequently, we provide an overview of prevailing guidelines, ongoing investigations, and prospective research trajectories related to targeted therapeutic interventions, drawing insights from randomized clinical trials and other pertinent studies. This review focus on a comprehensive examination of preclinical and clinical data substantiating the efficacy of these therapeutic modalities, emphasizing the potential of combinatorial regimens and novel therapies to enhance the quality of life for individuals afflicted with PDAC. Lastly, the review delves into the contemporary application and ongoing research endeavors concerning targeted therapy for PDAC. This synthesis serves to bridge the molecular elucidation of PDAC with its clinical implications, the evolution of innovative therapeutic strategies, and the changing landscape of treatment approaches.

Molecular profile of metastasis, cell plasticity and EMT in pancreatic cancer: a pre-clinical connection to aggressiveness and drug resistance

The metastasis is a multistep process in which a small proportion of cancer cells are detached from the colony to enter into blood cells for obtaining a new place for metastasis and proliferation. The metastasis and cell plasticity are considered major causes of cancer-related deaths since they improve the malignancy of cancer cells and provide poor prognosis for patients. Furthermore, enhancement in the aggressiveness of cancer cells has been related to the development of drug resistance. Metastasis of pancreatic cancer (PC) cells has been considered one of the major causes of death in patients and their undesirable prognosis. PC is among the most malignant tumors of the gastrointestinal tract and in addition to lifestyle, smoking, and other factors, genomic changes play a key role in its progression. The stimulation of EMT in PC cells occurs as a result of changes in molecular interaction, and in addition to increasing metastasis, EMT participates in the development of chemoresistance. The epithelial, mesenchymal, and acinar cell plasticity can occur and determines the progression of PC. The major molecular pathways including STAT3, PTEN, PI3K/Akt, and Wnt participate in regulating the metastasis of PC cells. The communication in tumor microenvironment can provide by exosomes in determining PC metastasis. The components of tumor microenvironment including macrophages, neutrophils, and cancer-associated fibroblasts can modulate PC progression and the response of cancer cells to chemotherapy.

Improving the prognosis of pancreatic cancer: insights from epidemiology, genomic alterations, and therapeutic challenges

Pancreatic cancer, notorious for its late diagnosis and aggressive progression, poses a substantial challenge owing to scarce treatment alternatives. This review endeavors to furnish a holistic insight into pancreatic cancer, encompassing its epidemiology, genomic characterization, risk factors, diagnosis, therapeutic strategies, and treatment resistance mechanisms. We delve into identifying risk factors, including genetic predisposition and environmental exposures, and explore recent research advancements in precursor lesions and molecular subtypes of pancreatic cancer. Additionally, we highlight the development and application of multi-omics approaches in pancreatic cancer research and discuss the latest combinations of pancreatic cancer biomarkers and their efficacy. We also dissect the primary mechanisms underlying treatment resistance in this malignancy, illustrating the latest therapeutic options and advancements in the field. Conclusively, we accentuate the urgent demand for more extensive research to enhance the prognosis for pancreatic cancer patients.

Biological characteristics of pancreatic ductal adenocarcinoma: Initiation to malignancy, intracellular to extracellular

Pancreatic ductal adenocarcinoma (PDAC) is a highly life-threatening tumour with a low early-detection rate, rapid progression and a tendency to develop resistance to chemotherapy. Therefore, understanding the regulatory mechanisms underlying the initiation, development and metastasis of pancreatic cancer is necessary for enhancing therapeutic effectiveness. In this review, we summarised single-gene mutations (including KRAS, CDKN2A, TP53, SMAD4 and some other less prevalent mutations), epigenetic changes (including DNA methylation, histone modifications and RNA interference) and large chromosome alterations (such as copy number variations, chromosome rearrangements and chromothripsis) associated with PDAC. In addition, we discussed variations in signalling pathways that act as intermediate oncogenic factors in PDAC, including PI3K/AKT, MAPK/ERK, Hippo and TGF-β signalling pathways. The focus of this review was to investigate alterations in the microenvironment of PDAC, particularly the role of immunosuppressive cells, cancer-associated fibroblasts, lymphocytes, other para-cancerous cells and tumour extracellular matrix in tumour progression. Peripheral axons innervating the pancreas have been reported to play a crucial role in the development of cancer. In addition, tumour cells can influence the behaviour of neighbouring non-tumour cells by secreting certain factors, both locally and at a distance. In this review, we elucidated the alterations in intracellular molecules and the extracellular environment that occur during the progression of PDAC. Altogether, this review may enhance the understanding of the biological characteristics of PDAC and guide the development of more precise treatment strategies.

Identification of novel curcumin derivatives against pancreatic cancer: a comprehensive approach integrating 3D-QSAR pharmacophore modeling, virtual screening, and molecular dynamics simulations

Pancreatic cancer, known as the "silent killer," poses a daunting challenge in cancer therapy. The dysregulation of the PI3Kα signaling pathway in pancreatic cancer has attracted considerable interest as a promising target for therapeutic intervention. In this regard, the use of curcumin derivatives as inhibitors of PI3Kα has emerged, providing a novel and promising avenue for developing effective treatments for this devastating disease. Computational approaches were employed to explore this potential and investigate 58 curcumin derivatives with cytotoxic activity against the Panc-1 cell line. Our approach involved ligand-based pharmacophore modeling and atom-based 3D-QSAR analysis. The resulting QSAR model derived from the best-fitted pharmacophore hypothesis (AAHRR_1) demonstrated remarkable performance with high correlation coefficients (R2) of 0.990 for the training set and 0.977 for the test set. The cross-validation coefficient (Q2) of 0.971 also validated the model's predictive power. Tropsha's recommended criteria, including the Y-randomization test, were employed to ensure its reliability. Furthermore, an enrichment study was conducted to evaluate the model's performance in identifying active compounds. AAHRR_1 was used to screen a curated PubChem database of curcumin-related compounds. Two molecules (CID156189304 and CID154728220) exhibited promising pharmacokinetic properties and higher docking scores than Alpelisib, warranting further investigation. Extensive molecular dynamics simulations provided crucial insights into the conformational dynamics within the binding site, validating their stability and behavior. These findings contribute to our understanding of the potential therapeutic effectiveness of these compounds as PI3Kα inhibitors in pancreatic cancer.Communicated by Ramaswamy H. Sarma.

Transducing compressive forces into cellular outputs in cancer and beyond

In living organisms, cells sense mechanical forces (shearing, tensile, and compressive) and respond to those physical cues through a process called mechanotransduction. This process includes the simultaneous activation of biochemical signaling pathways. Recent studies mostly on human cells revealed that compressive forces selectively modulate a wide range of cell behavior, both in compressed and in neighboring less compressed cells. Besides participating in tissue homeostasis such as bone healing, compression is also involved in pathologies, including intervertebral disc degeneration or solid cancers. In this review, we will summarize the current scattered knowledge of compression-induced cell signaling pathways and their subsequent cellular outputs, both in physiological and pathological conditions, such as solid cancers.

m6A eraser FTO impairs gemcitabine resistance in pancreatic cancer through influencing NEDD4 mRNA stability by regulating the PTEN/PI3K/AKT pathway

BACKGROUND

Gemcitabine resistance has brought great challenges to the treatment of pancreatic cancer. The N6-methyladenosine (m6A) mutation has been shown to have a significant regulatory role in chemosensitivity; however, it is not apparent whether gemcitabine resistance can be regulated by fat mass and obesity-associated protein (FTO).

METHODS

Cells with established gemcitabine resistance and tissues from pancreatic cancer patients were used to evaluate FTO expression. The biological mechanisms of the effects of FTO on gemcitabine resistant cells were investigated using CCK-8, colony formation assay, flow cytometry, and inhibitory concentration 50. Immunoprecipitation/mass spectrometry, MeRIP-seq, RNA sequencing and RIP assays, RNA stability, luciferase reporter, and RNA pull down assays were employed to examine the mechanism of FTO affecting gemcitabine resistant pancreatic cancer cells.

RESULTS

The results revealed that FTO was substantially expressed in cells and tissues that were resistant to gemcitabine. Functionally, the gemcitabine resistance of pancreatic cancer could be enhanced by FTO, while its depletion inhibited the growth of gemcitabine resistant tumor cells in vivo. Immunoprecipitation/mass spectrometry showed that the FTO protein can be bound to USP7 and deubiquitinated by USP7, leading to the upregulation of FTO. At the same time, FTO knockdown significantly decreased the expression level of NEDD4 in an m6A-dependent manner. RNA pull down and RNA immunoprecipitation verified YTHDF2 as the reader of NEDD4, which promoted the chemoresistance of gemcitabine resistant cells. FTO knockdown markedly increased the PTEN expression level in an NEDD4-dependent manner and influenced the chemosensitivity to gemcitabine through the PI3K/AKT pathway in pancreatic cancer cells.

CONCLUSION

In conclusion, we found that gemcitabine resistance in pancreatic cancer can be influenced by FTO that demethylates NEDD4 RNA in a m6A-dependent manner, which then influences the PTEN expression level and thereby affects the PI3K/AKT pathway. We also identified that the FTO level can be upregulated by USP7.

Remodeling of Stromal Immune Microenvironment by Urolithin A Improves Survival with Immune Checkpoint Blockade in Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is a significant contributor to cancer-related morbidity and mortality, and it is known for its resistance to conventional treatment regimens, including chemotherapy and immune checkpoint blockade (ICB)-based therapies. We have previously shown that Urolithin A (Uro A), a gut microbial metabolite derived from pomegranates, can target and inhibit KRAS-dependent PI3K/AKT/mTOR signaling pathways to overcome therapeutic resistance and improve survival in PDAC. However, the effect of Uro A on the tumor immune microenvironment and its ability to enhance ICB efficacy has not been explored. This study demonstrates that Uro A treatment reduces stromal fibrosis and reinvigorates the adaptive T-cell immune response to overcome resistance to PD-1 blockade in a genetically engineered mouse model (GEMM) of PDAC. Flow cytometric-based analysis of Uro A-treated mouse tumors revealed a significant attenuation of immunosuppressive tumor-associated M2-like macrophages with a concurrent increase in the infiltration of CD4+ and CD8+ T cells with memory-like phenotype along with reduced expression of the exhaustion-associated protein, PD-1. Importantly, the combination of Uro A treatment with anti-PD-1 immunotherapy promoted enhancement of the antitumor response with increased infiltration of CD4+ Th1 cells, ultimately resulting in a remarkable improvement in overall survival in GEMM of PDAC. Overall, our findings provide preclinical evidence for the potential of Uro A as a novel therapeutic agent to increase sensitivity to immunotherapy in PDAC and warrant further mechanistic exploration in preclinical and clinical studies.

Significance

Immunotherapeutic agents are ineffective against pancreatic cancer, mainly due to the immunosuppressive tumor microenvironment and stromal desmoplasia. Our current study demonstrates the therapeutic utility of a novel gut microbial metabolite, Uro A, to remodel the stromal-immune microenvironment and improve overall survival with anti-PD-1 therapy in pancreatic cancer.

Therapeutic targeting of tumour myeloid cells

Myeloid cells are pivotal within the immunosuppressive tumour microenvironment. The accumulation of tumour-modified myeloid cells derived from monocytes or neutrophils - termed 'myeloid-derived suppressor cells' - and tumour-associated macrophages is associated with poor outcome and resistance to treatments such as chemotherapy and immune checkpoint inhibitors. Unfortunately, there has been little success in large-scale clinical trials of myeloid cell modulators, and only a few distinct strategies have been used to target suppressive myeloid cells clinically so far. Preclinical and translational studies have now elucidated specific functions for different myeloid cell subpopulations within the tumour microenvironment, revealing context-specific roles of different myeloid cell populations in disease progression and influencing response to therapy. To improve the success of myeloid cell-targeted therapies, it will be important to target tumour types and patient subsets in which myeloid cells represent the dominant driver of therapy resistance, as well as to determine the most efficacious treatment regimens and combination partners. This Review discusses what we can learn from work with the first generation of myeloid modulators and highlights recent developments in modelling context-specific roles for different myeloid cell subtypes, which can ultimately inform how to drive more successful clinical trials.

Immunosuppression, immune escape, and immunotherapy in pancreatic cancer: focused on the tumor microenvironment

Pancreatic ductal adenocarcinoma (PDAC), the most common type of pancreatic cancer, is characterized by poor treatment response and low survival time. The current clinical treatment for advanced PDAC is still not effective. In recent years, the research and application of immunotherapy have developed rapidly and achieved substantial results in many malignant tumors. However, the translational application in PDAC is still far from satisfactory and needs to be developed urgently. To carry out the study of immunotherapy, it is necessary to fully decipher the immune characteristics of PDAC. This review summarizes the recent progress of the tumor microenvironment (TME) of PDAC and highlights its link with immunotherapy. We describe the molecular cues and corresponding intervention methods, collate several promising targets and progress worthy of further study, and put forward the importance of integrated immunotherapy to provide ideas for future research of TME and immunotherapy of PDAC.

Targeting Class I-II-III PI3Ks in Cancer Therapy: Recent Advances in Tumor Biology and Preclinical Research

Phosphatidylinositol-3-kinase (PI3K) enzymes, producing signaling phosphoinositides at plasma and intracellular membranes, are key in intracellular signaling and vesicular trafficking pathways. PI3K is a family of eight enzymes divided into three classes with various functions in physiology and largely deregulated in cancer. Here, we will review the recent evidence obtained during the last 5 years on the roles of PI3K class I, II and III isoforms in tumor biology and on the anti-tumoral action of PI3K inhibitors in preclinical cancer models. The dependency of tumors to PI3K isoforms is dictated by both genetics and context (e.g., the microenvironment). The understanding of class II/III isoforms in cancer development and progression remains scarce. Nonetheless, the limited available data are consistent and reveal that there is an interdependency between the pathways controlled by all PI3K class members in their role to promote cancer cell proliferation, survival, growth, migration and metabolism. It is unknown whether this feature contributes to partial treatment failure with isoform-selective PI3K inhibitors. Hence, a better understanding of class II/III functions to efficiently inhibit their positive and negative interactions with class I PI3Ks is needed. This research will provide the proof-of-concept to develop combination treatment strategies targeting several PI3K isoforms simultaneously.

Clustering analysis and prognostic model based on PI3K/AKT-related genes in pancreatic cancer

Background

Pancreatic cancer is one of most aggressive malignancies with a dismal prognosis. Activation of PI3K/AKT signaling is instrumental in pancreatic cancer tumorigenesis. The aims of this study were to identify the molecular clustering, prognostic value, relationship with tumor immunity and targeting of PI3K/AKT-related genes (PARGs) in pancreatic cancer using bioinformatics.

Methods

The GSEA website was searched for PARGs, and pancreatic cancer-related mRNA data and clinical profiles were obtained through TCGA downloads. Prognosis-related genes were identified by univariate Cox regression analysis, and samples were further clustered by unsupervised methods to identify significant differences in survival, clinical information and immune infiltration between categories. Next, a prognostic model was constructed using Lasso regression analysis. The model was well validated by univariate and multivariate Cox regression analyses, Kaplan-Meier survival analysis and ROC curves, and correlations between risk scores and patient pathological characteristics were identified. Finally, GSEA, drug prediction and immune checkpoint protein analyses were performed.

Results

Pancreatic cancers were divided into Cluster 1 (C1) and Cluster 2 (C1) according to PARG mRNA expression. C1 exhibited longer overall survival (OS) and higher immune scores and CTLA4 expression, whereas C2 exhibited more abundant PD-L1. A 6-PARG-based prognostic model was constructed to divide pancreatic cancer patients into a high-risk score (HRS) group and a low-risk score (LRS) group, where the HRS group exhibited worse OS. The risk score was defined as an independent predictor of OS. The HRS group was significantly associated with pancreatic cancer metastasis, aggregation and immune score. Furthermore, the HRS group exhibited immunosuppression and was sensitive to radiotherapy and guitarbine chemotherapy. Multidrug sensitivity prediction analysis indicated that the HRS group may be sensitive to PI3K/AKT signaling inhibitors (PIK-93, GSK2126458, CAL-101 and rapamycin) and ATP concentration regulators (Thapsigargin). In addition, we confirmed the oncogenic effect of protein phosphatase 2 regulatory subunit B'' subunit alpha (PPP2R3A) in pancreatic cancer in vitro and in vivo.

Conclusions

PARGs predict prognosis, tumor immune profile, radiotherapy and chemotherapy drug sensitivity and are potential predictive markers for pancreatic cancer treatment that can help clinicians make decisions and personalize treatment.

Arsenic trioxide sensitizes pancreatic cancer cells to gemcitabine through downregulation of the TIMP1/PI3K/AKT/mTOR axis

Gemcitabine (GEM) is the first-line medication for pancreatic ductal adenocarcinoma (PDAC). However, over some treatment cycles, GEM sensitivity declines and chemotherapeutic resistance develops, resulting in tumor recurrence and metastasis. Therefore, it is critical to elucidate the mechanism of GEM chemoresistance. And a specific drug that is closely related to the mechanism is urgently required to sensitize GEM. Here, tissue inhibitor of matrix metalloproteinases 1 (TIMP1) and phosphorylated mammalian target of rapamycin (p-mTOR) were found to be substantially elevated in PDAC patients and were associated with worse overall survival. The TIMP1/PI3K/AKT/mTOR pathway was found in GEM-resistant PDAC cells and was revealed to be involved in epithelial-mesenchymal transition (EMT) and apoptosis. Furthermore, arsenic trioxide (ATO), a basic therapeutic drug for acute promyelocytic leukemia, mediated TIMP1 reduction by inducing reactive oxygen species generation and hampered the subsequent PI3K/AKT/mTOR axis. Moreover, the combination of ATO and GEM cooperatively suppressed the TIMP1/PI3K/AKT/mTOR pathway, synergistically inhibited EMT and promoted apoptosis. In vitro and in vivo, ATO combined with GEM has a collaborative anticancer effect, inhibiting cancer cell proliferation, migration, invasion, and suppressing tumor growth both in PDAC parental and GEM-resistant cells. Overall, the TIMP1/PI3K/AKT/mTOR pathway is present in PDAC and linked to GEM resistance. ATO suppresses the axis to sensitize GEM and reverse GEM resistance, suggesting a promising treatment for the disease.

Targeting PI3K/AKT/mTOR Signaling Pathway in Pancreatic Cancer: From Molecular to Clinical Aspects

Although pancreatic cancer (PC) was considered in the past an orphan cancer type due to its low incidence, it may become in the future one of the leading causes of cancer death. Pancreatic ductal adenocarcinoma (PDAC) is the most frequent type of PC, being a highly aggressive malignancy and having a 5-year survival rate of less than 10%. Non-modifiable (family history, age, genetic susceptibility) and modifiable (smoking, alcohol, acute and chronic pancreatitis, diabetes mellitus, intestinal microbiota) risk factors are involved in PC pathogenesis. Chronic inflammation induced by various factors plays crucial roles in PC development from initiation to metastasis. In multiple malignant conditions such as PC, cytokines, chemokines, and growth factors activate the class I phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) (PI3K/AKT/mTOR) signaling pathway, which plays key roles in cell growth, survival, proliferation, metabolism, and motility. Currently, mTOR, AKT, and PI3K inhibitors are used in clinical studies. Moreover, PI3K/mTOR dual inhibitors are being tested in vitro and in vivo with promising results for PC patients. The main aim of this review is to present PC incidence, risk factors, tumor microenvironment development, and PI3K/AKT/mTOR dysregulation and inhibitors used in clinical, in vivo, and in vitro studies.

Systematic exploration of the underlying mechanism of gemcitabine resistance in pancreatic adenocarcinoma

Resistance to gemcitabine is the main challenge of chemotherapy for pancreatic ductal adenocarcinoma (PDAC). Hence, the development of a response signature to gemcitabine is essential for precision therapy of PDAC. However, existing quantitative signatures of gemcitabine are susceptible to batch effects and variations in sequencing platforms. Therefore, based on within-sample relative expression ordering of pairwise genes, we developed a transcriptome-based gemcitabine signature consisting of 28 gene pairs (28-GPS) that could predict response to gemcitabine for PDAC at the individual level. The 28-GPS was superior to previous quantitative signatures in terms of classification accuracy and prognostic performance. Resistant samples classified by 28-GPS showed poorer overall survival, higher genomic instability, lower immune infiltration, higher metabolic level and higher-fidelity DNA damage repair compared with sensitive samples. In addition, we found that gemcitabine combined with phosphoinositide 3-kinase (PI3K) inhibitor may be an alternative treatment strategy for PDAC. Single-cell analysis revealed that cancer cells in the same PDAC sample showed both the characteristics of sensitivity and resistance to gemcitabine, and the activation of the TGFβ signalling pathway could promote progression of PDAC. In brief, 28-GPS could robustly determine whether PDAC is resistant or sensitive to gemcitabine, and may be an auxiliary tool for clinical treatment.

Sympathetic axonal sprouting induces changes in macrophage populations and protects against pancreatic cancer

Neuronal nerve processes in the tumor microenvironment were highlighted recently. However, the origin of intra-tumoral nerves remains poorly known, in part because of technical difficulties in tracing nerve fibers via conventional histological preparations. Here, we employ three-dimensional (3D) imaging of cleared tissues for a comprehensive analysis of sympathetic innervation in a murine model of pancreatic ductal adenocarcinoma (PDAC). Our results support two independent, but coexisting, mechanisms: passive engulfment of pre-existing sympathetic nerves within tumors plus an active, localized sprouting of axon terminals into non-neoplastic lesions and tumor periphery. Ablation of the innervating sympathetic nerves increases tumor growth and spread. This effect is explained by the observation that sympathectomy increases intratumoral CD163+ macrophage numbers, which contribute to the worse outcome. Altogether, our findings provide insights into the mechanisms by which the sympathetic nervous system exerts cancer-protective properties in a mouse model of PDAC.

Targeting PI3K Pathway in Pancreatic Ductal Adenocarcinoma: Rationale and Progress

Pancreatic ductal adenocarcinoma (PDAC) remains among the deadliest solid tumors that remain treatment-refractory and show a dismal prognosis. More than 90% of PDAC tumors harbor mutations in the K-Ras that exert a strong pro-tumorigenic effect by activating several downstream effector pathways, including phosphatidylinositol-3-kinase (PI3K)-Akt. The role of frequently activated PI3K/Akt pathway in promoting PDAC aggressiveness is well established. Therapeutic approaches targeting PI3K and downstream signaling components in different cellular compartments, including tumor, stromal and immune cells, have directly impacted the tumor burden in this cancer type. Our previous work has demonstrated that targeting the PI3K/Akt/mTOR pathway reduced tumor growth and improved survival in the genetic mouse model of PDAC. Here, we discuss the significance of targeting PI3K signaling and the biological impact of PI3K inhibition in modulating the tumor-stromal immune crosstalk within the microenvironment of pancreatic cancer. Furthermore, this review updates on the current challenges involving the therapeutic implications of targeting this pathway in PDAC.

PI3Kα targeting, nipping pancreatic cancer evolution in the bud

Thibault et al (2021) elucidate key signalling events mediating metastatic evolution in pancreatic ductal adenocarcinoma (PDAC) by demonstrating a role of PI3Kα in the regulation of macro‐metastatic disease and a corresponding pro‐tumoural immune response supporting disease progression.