Exploring the Immunomodulatory Potential of Pancreatic Cancer-Derived Extracellular Vesicles through Proteomic and Functional Analyses.

Pancreatic cancer (PC) has a poor prognosis and displays resistance to immunotherapy. A better understanding of tumor-derived extracellular vesicle (EV) effects on immune responses might contribute to improved immunotherapy. EVs derived from Capan-2 and BxPC-3 PC cells isolated by ultracentrifugation were characterized by atomic force microscopy, Western blot (WB), nanoparticle tracking analysis, and label-free proteomics. Fresh PBMCs from healthy donors were treated with PC- or control-derived heterologous EVs, followed by flow cytometry analysis of CD8+ and CD4+ lymphocytes. The proteomics of lymphocytes sorted from EV-treated or untreated PBMCs was performed, and the IFN-γ concentration was measured by ELISA. Notably, most of the proteins identified in Capan-2 and BxPC-3 EVs by the proteomic analysis were connected in a single functional network (p = 1 × 10-16) and were involved in the "Immune System" (FDR: 1.10 × 10-24 and 3.69 × 10-19, respectively). Interestingly, the treatment of healthy donor-derived PBMCs with Capan-2 EVs but not with BxPC-3 EVs or heterologous control EVs induced early activation of CD8+ and CD4+ lymphocytes. The proteomics of lymphocytes sorted from EV-treated PBMCs was consistent with their activation by Capan-2 EVs, indicating IFN-γ among the major upstream regulators, as confirmed by ELISA. The proteomic and functional analyses indicate that PC-EVs have pleiotropic effects, and some may activate early immune responses, which might be relevant for the development of highly needed immunotherapeutic strategies in this immune-cold tumor.

Effects of GHRH Deficiency and GHRH Antagonism on Emotional Disorders in Mice.

Growth hormone (GH)-releasing hormone (GHRH) has been suggested to play a crucial role in brain function. We aimed to further investigate the effects of a novel GHRH antagonist of the Miami (MIA) series, MIA-602, on emotional disorders and explore the relationships between the endocrine system and mood disorders. In this context, the effects induced by MIA-602 were also analyzed in comparison to vehicle-treated mice with GH deficiency due to generalized ablation of the GHRH gene (GHRH knock out (GHRHKO)). We show that the chronic subcutaneous administration of MIA-602 to wild type (+/+) mice, as well as generalized ablation of the GHRH gene, is associated with anxiolytic and antidepressant behavior. Moreover, immunohistochemical and Western blot analyses suggested an evident activation of Nrf2, HO1, and NQO1 in the prefrontal cortex of both +/+ mice treated with MIA-602 (+/+ MIA-602) and homozygous GHRHKO (-/- control) animals. Finally, we also found significantly decreased COX-2, iNOS, NFkB, and TNF-α gene expressions, as well as increased P-AKT and AKT levels in +/+ MIA-602 and -/- control animals compared to +/+ mice treated with vehicle (+/+ control). We hypothesize that the generalized ablation of the GHRH gene leads to a dysregulation of neural pathways, which is mimicked by GHRH antagonist treatment.

Prognostic value of gender and primary tumor location in metastatic colon cancer.

Sex might influence prognosis in patients affected by colorectal cancer. We retrospectively studied a cohort of patients affected by metastatic colon cancer (mCC) stratified by sex and primary tumor location. RAS mutational status was also included in the analysis. Overall, 616 patients met the eligibility criteria, 261 women and 355 men. Neither gender, nor RAS mutational status influenced overall survival (OS) in the entire population. As expected, patients with right-sided colon cancer (RCC) had a significant shorter OS compared to those with left-sided colon cancer (LCC) (21.3 vs 33.1 months, p= 0.002). When the analysis was performed stratifying for gender, RCC retained worse prognosis among men (OS 20.5 vs 33.9 months, p= 0.008), but not among women (p= 0.132). Similarly, the presence of RAS mutations had no prognostic effect in women, but was significantly associate with shorter survival in men (OS 29.5 vs 33.7 months, p= 0.046). In addition, when comparing clinical outcome of women or men according to sidedness and RAS mutational status, RCC was associated with dismal prognosis only in men with RAS mutated tumor (OS 17.2 vs 32.3 months, p= 0.008). Our study highlights the importance of gender in the outcome of patients with mCC.

CAR-T-Derived Extracellular Vesicles: A Promising Development of CAR-T Anti-Tumor Therapy.

Extracellular vesicles (EVs) are a heterogenous population of plasma membrane-surrounded particles that are released in the extracellular milieu by almost all types of living cells. EVs are key players in intercellular crosstalk, both locally and systemically, given that they deliver their cargoes (consisting of proteins, lipids, mRNAs, miRNAs, and DNA fragments) to target cells, crossing biological barriers. Those mechanisms further trigger a wide range of biological responses. Interestingly, EV phenotypes and cargoes and, therefore, their functions, stem from their specific parental cells. For these reasons, EVs have been proposed as promising candidates for EV-based, cell-free therapies. One of the new frontiers of cell-based immunotherapy for the fight against refractory neoplastic diseases is represented by genetically engineered chimeric antigen receptor T (CAR-T) lymphocytes, which in recent years have demonstrated their effectiveness by reaching commercialization and clinical application for some neoplastic diseases. CAR-T-derived EVs represent a recent promising development of CAR-T immunotherapy approaches. This crosscutting innovative strategy is designed to exploit the advantages of genetically engineered cell-based immunotherapy together with those of cell-free EVs, which in principle might be safer and more efficient in crossing biological and tumor-associated barriers. In this review, we underlined the potential of CAR-T-derived EVs as therapeutic agents in tumors.

Resveratrol Derivative Exhibits Marked Antiproliferative Actions, Affecting Stemness in Pancreatic Cancer Cells.

Pancreatic cancer (PC) is one of the deadliest malignancies, with an increasing incidence and limited response to current therapeutic options. Therefore, more effective and low-toxic agents are needed to improve PC patients' outcomes. Resveratrol (RSV) is a natural polyphenol with multiple biological properties, including anticancer effects. In this study, we explored the antiproliferative activities of newly synthetized RSV analogues in a panel of PC cell lines and evaluated the physicochemical properties of the most active compound. This derivative exhibited marked antiproliferative effects in PC cells through mechanisms involving DNA damage, apoptosis induction, and interference in cell cycle progression, as assessed using flow cytometry and immunoblot analysis of cell cycle proteins, PARP cleavage, and H2AX phosphorylation. Notably, the compound induced a consistent reduction in the PC cell subpopulation with a CD133+EpCAM+ stem-like phenotype, paralleled by dramatic effects on cell clonogenicity. Moreover, the RSV derivative had negligible toxicity against normal HFF-1 cells and, thus, good selectivity index values toward PC cell lines. Remarkably, its higher lipophilicity and stability in human plasma, as compared to RSV, might ensure a better permeation along the gastrointestinal tract. Our results provide insights into the mechanisms of action contributing to the antiproliferative activity of a synthetic RSV analogue, supporting its potential value in the search for effective and safe agents in PC treatment.

Optimizing the Choice for Adjuvant Chemotherapy in Gastric Cancer.

Advances in the management of gastric cancer have improved patient survival in the last decade. Nonetheless, the number of patients relapsing and dying after a diagnosis of localized gastric cancer is still too high, even in early stages (10% in stage I). Adjuvant systemic chemotherapy has been proven to significantly improve outcomes. In the present article we have critically reviewed the clinical trials that guide the current clinical practice in the adjuvant treatment of patients affected by resectable gastric cancer, focusing on the different approaches worldwide, i.e., adjuvant chemotherapy, adjuvant chemoradiotherapy, and perioperative chemotherapy. We also delineate the clinical-pathological characteristics that are commonly taken into account to identify patients at a higher risk of recurrence and requiring adjuvant chemotherapy, and also describe novel biomarkers and therapeutic agents that might allow personalization of the treatment.

High Blood Concentration of Leukocyte-Derived Extracellular Vesicles Is Predictive of Favorable Clinical Outcomes in Patients with Pancreatic Cancer: Results from a Multicenter Prospective Study.

Pancreatic cancer (PC) is one of the leading causes of cancer-related death worldwide. Identification of novel tumor biomarkers is highly advocated in PC to optimize personalized treatment algorithms. Blood-circulating extracellular vesicles hold promise for liquid biopsy application in cancer. We used an optimized flow cytometry protocol to study leukocyte-derived EVs (CD45+) and PD-L1+ EVs in blood from 56 pancreatic cancer patients and 48 healthy controls (HCs). Our results show that PC patients presented higher blood levels of total EVs (p = 0.0003), leukocyte-derived EVs (LEVs) (p = 0.001) and PD-L1+ EVs (p = 0.01), as compared with HCs. Interestingly, a blood concentration of LEVs at baseline was independently associated with improved overall survival in patients with borderline resectable or primary unresectable PC (HR = 0.17; 95% CI 0.04-0.79; p = 0.02). Additionally, increased blood-based LEVs were independently correlated with prolonged progression-free survival (HR = 0.10; 95% CI 0.01-0.82; p = 0.03) and significantly associated with higher disease control rate (p = 0.02) in patients with advanced PC receiving standard chemotherapy. Notably, a strong correlation between a decrease in blood LEVs concentration during chemotherapy and disease control was observed (p = 0.005). These intriguing findings point to the potential of LEVs as novel blood-based EV biomarkers for improved personalized medicine in patients affected by PC.

Benzothiazole Derivatives Endowed with Antiproliferative Activity in Paraganglioma and Pancreatic Cancer Cells: Structure-Activity Relationship Studies and Target Prediction Analysis.

The antiproliferative effects played by benzothiazoles in different cancers have aroused the interest for these molecules as promising antitumor agents. In this work, a library of phenylacetamide derivatives containing the benzothiazole nucleus was synthesized and compounds were tested for their antiproliferative activity in paraganglioma and pancreatic cancer cell lines. The novel synthesized compounds induced a marked viability reduction at low micromolar concentrations both in paraganglioma and pancreatic cancer cells. Derivative 4l showed a greater antiproliferative effect and higher selectivity index against cancer cells, as compared to other compounds. Notably, combinations of derivative 4l with gemcitabine at low concentrations induced enhanced and synergistic effects on pancreatic cancer cell viability, thus supporting the relevance of compound 4l in the perspective of clinical translation. A target prediction analysis was also carried out on 4l by using multiple computational tools, identifying cannabinoid receptors and sentrin-specific proteases as putative targets contributing to the observed antiproliferative activity.

Drug Repurposing, an Attractive Strategy in Pancreatic Cancer Treatment: Preclinical and Clinical Updates.

Pancreatic cancer (PC) is one of the deadliest malignancies worldwide, since patients rarely display symptoms until an advanced and unresectable stage of the disease. Current chemotherapy options are unsatisfactory and there is an urgent need for more effective and less toxic drugs to improve the dismal PC therapy. Repurposing of non-oncology drugs in PC treatment represents a very promising therapeutic option and different compounds are currently being considered as candidates for repurposing in the treatment of this tumor. In this review, we provide an update on some of the most promising FDA-approved, non-oncology, repurposed drug candidates that show prominent clinical and preclinical data in pancreatic cancer. We also focus on proposed mechanisms of action and known molecular targets that they modulate in PC. Furthermore, we provide an explorative bioinformatic analysis, which suggests that some of the PC repurposed drug candidates have additional, unexplored, oncology-relevant targets. Finally, we discuss recent developments regarding the immunomodulatory role displayed by some of these drugs, which may expand their potential application in synergy with approved anticancer immunomodulatory agents that are mostly ineffective as single agents in PC.

Exosomes as Pleiotropic Players in Pancreatic Cancer.

Pancreatic cancer (PC) incidence is rising and due to late diagnosis, combined with unsatisfactory response to current therapeutic approaches, this tumor has an extremely high mortality rate. A better understanding of the mechanisms underlying pancreatic carcinogenesis is of paramount importance for rational diagnostic and therapeutic approaches. Multiple lines of evidence have showed that exosomes are actively involved in intercellular communication by transferring their cargos of bioactive molecules to recipient cells within the tumor microenvironment and systemically. Intriguingly, exosomes may exert both protumor and antitumor effects, supporting or hampering processes that play a role in the pathogenesis and progression of PC, including shifts in tumor metabolism, proliferation, invasion, metastasis, and chemoresistance. They also have a dual role in PC immunomodulation, exerting immunosuppressive or immune enhancement effects through several mechanisms. PC-derived exosomes also induce systemic metabolic alterations, leading to the onset of diabetes and weight loss. Moreover, exosomes have been described as promising diagnostic and prognostic biomarkers for PC. Their potential application in PC therapy as drug carriers and therapeutic targets is under investigation. In this review, we provide an overview of the multiple roles played by exosomes in PC biology through their specific cargo biomolecules and of their potential exploitation in early diagnosis and treatment of PC.

Screening of Benzimidazole-Based Anthelmintics and Their Enantiomers as Repurposed Drug Candidates in Cancer Therapy.

Repurposing of approved non-antitumor drugs represents a promising and affordable strategy that may help to increase the repertoire of effective anticancer drugs. Benzimidazole-based anthelmintics are antiparasitic drugs commonly employed both in human and veterinary medicine. Benzimidazole compounds are being considered for drug repurposing due to antitumor activities displayed by some members of the family. In this study, we explored the effects of a large series of benzimidazole-based anthelmintics (and some enantiomerically pure forms of those containing a stereogenic center) on the viability of different tumor cell lines derived from paraganglioma, pancreatic and colorectal cancer. Flubendazole, parbendazole, oxibendazole, mebendazole, albendazole and fenbendazole showed the most consistent antiproliferative effects, displaying IC50 values in the low micromolar range, or even in the nanomolar range. In silico evaluation of their physicochemical, pharmacokinetics and medicinal chemistry properties also provided useful information related to the chemical structures and potential of these compounds. Furthermore, in view of the potential repurposing of these drugs in cancer therapy and considering that pharmaceutically active compounds may have different mechanisms of action, we performed an in silico target prediction to assess the polypharmacology of these benzimidazoles, which highlighted previously unknown cancer-relevant molecular targets.

Phenotypic and Proteomic Analysis Identifies Hallmarks of Blood Circulating Extracellular Vesicles in NSCLC Responders to Immune Checkpoint Inhibitors.

Immune checkpoint inhibitors (ICIs) induce durable clinical responses only in a subset of advanced non-small cell lung cancer (NSCLC) patients. There is a need to identify mechanisms of ICI resistance and immunotherapy biomarkers to improve clinical benefit. In this study, we evaluated the prognostic and predictive value of circulating endothelial and leukocyte-derived extracellular vesicles (EV) in patients with advanced NSCLC treated with anti-PD-1/PD-L1 agents. In addition, the relationship between total blood circulating EV proteome and response to ICIs was investigated. An optimized flow cytometry method was employed for the identification and subtyping of blood circulating EVs in 59 patients with advanced NSCLC. Blood samples were collected from patients receiving anti-PD-1/PD-L1 inhibitors (n = 31) or chemotherapy (n = 28). An exploratory proteomic analysis of sorted blood EVs was conducted in a subset of patients. Our results show that a low blood concentration of circulating endothelial-derived EVs before treatment was strongly associated to longer overall survival (p = 0.0004) and higher disease control rate (p = 0.045) in patients treated with ICIs. Interestingly, shotgun proteomics revealed that EVs of responders to anti-PD-1 therapy had a specific protein cargo before treatment. In addition, EV protein cargo was specifically modulated during immunotherapy. We identified a previously unknown association between circulating endothelial-derived extracellular vesicle concentration and immunotherapy-related clinical outcomes. We also observed differences in circulating extracellular vesicle proteome according to anti-PD-1-based treatment response in NSCLC patients. Overall, these results may contribute to the identification of novel circulating biomarkers for rational immunotherapy approaches in patients affected by NSCLC.

The Role of Dysfunctional Adipose Tissue in Pancreatic Cancer: A Molecular Perspective.

Pancreatic cancer (PC) is a lethal malignancy with rising incidence and limited therapeutic options. Obesity is a well-established risk factor for PC development. Moreover, it negatively affects outcome in PC patients. Excessive fat accumulation in obese, over- and normal-weight individuals induces metabolic and inflammatory changes of adipose tissue microenvironment leading to a dysfunctional adipose "organ". This may drive the association between abnormal fat accumulation and pancreatic cancer. In this review, we describe several molecular mechanisms that underpin this association at both local and systemic levels. We focus on the role of adipose tissue-derived circulating factors including adipokines, hormones and pro-inflammatory cytokines, as well as on the impact of the local adipose tissue in promoting PC. A discussion on potential therapeutic interventions, interfering with pro-tumorigenic effects of dysfunctional adipose tissue in PC, is included. Considering the raise of global obesity, research efforts to uncover the molecular basis of the relationship between pancreatic cancer and adipose tissue dysfunction may provide novel insights for the prevention of this deadly disease. In addition, these efforts may uncover novel targets for personalized interventional strategies aimed at improving the currently unsatisfactory PC therapeutic options.

Synthesis and evaluation of a large library of nitroxoline derivatives as pancreatic cancer antiproliferative agents.

Pancreatic cancer (PC) is one of the deadliest carcinomas and in most cases, which are diagnosed with locally advanced or metastatic disease, current therapeutic options are highly unsatisfactory. Based on the anti-proliferative effects shown by nitroxoline, an old urinary antibacterial agent, we explored a large library of newly synthesised derivatives to unravel the importance of the OH moiety and pyridine ring of the parent compound. The new derivatives showed a valuable anti-proliferative effect and some displayed a greater effect as compared to nitroxoline against three pancreatic cancer cell lines with different genetic profiles. In particular, in silico pharmacokinetic data, clonogenicity assays and selectivity indexes of the most promising compounds showed several advantages for such derivatives, as compared to nitroxoline. Moreover, some of these novel compounds had stronger effects on cell viability and/or clonogenic capacity in PC cells as compared to erlotinib, a targeted agent approved for PC treatment.

Sulfonimide and Amide Derivatives as Novel PPARα Antagonists: Synthesis, Antiproliferative Activity, and Docking Studies.

An agonist-antagonist switching strategy was performed to discover novel PPARα antagonists. Phenyldiazenyl derivatives of fibrates were developed, bearing sulfonimide or amide functional groups. A second series of compounds was synthesized, replacing the phenyldiazenyl moiety with amide or urea portions. Final compounds were screened by transactivation assay, showing good PPARα antagonism and selectivity at submicromolar concentrations. When tested in cancer cell models expressing PPARα, selected derivatives induced marked effects on cell viability. Notably, 3c, 3d, and 10e displayed remarkable antiproliferative effects in two paraganglioma cell lines, with CC50 lower than commercial PPARα antagonist GW6471 and a negligible toxicity on normal fibroblast cells. Docking studies were also performed to elucidate the binding mode of these compounds and to help interpretation of SAR data.

Integrative proteomic and functional analyses provide novel insights into the action of the repurposed drug candidate nitroxoline in AsPC-1 cells.

We recently identified nitroxoline as a repurposed drug candidate in pancreatic cancer (PC) showing a dose-dependent antiproliferative activity in different PC cell lines. This antibiotic is effective in several in vitro and animal cancer models. To date, the mechanisms of nitroxoline anticancer action are largely unknown. Using shotgun proteomics we identified 363 proteins affected by nitroxoline treatment in AsPC-1 pancreatic cancer cells, including 81 consistently deregulated at both 24- and 48-hour treatment. These proteins previously unknown to be affected by nitroxoline were mostly downregulated and interconnected in a single highly-enriched network of protein-protein interactions. Integrative proteomic and functional analyses revealed nitroxoline-induced downregulation of Na/K-ATPase pump and ß-catenin, which associated with drastic impairment in cell growth, migration, invasion, increased ROS production and induction of DNA damage response. Remarkably, nitroxoline induced a previously unknown deregulation of molecules with a critical role in cell bioenergetics, which resulted in mitochondrial depolarization. Our study also suggests that deregulation of cytosolic iron homeostasis and of co-translational targeting to membrane contribute to nitroxoline anticancer action. This study broadens our understanding of the mechanisms of nitroxoline action, showing that the drug modulates multiple proteins crucial in cancer biology and previously unknown to be affected by nitroxoline.

The Benzimidazole-Based Anthelmintic Parbendazole: A Repurposed Drug Candidate That Synergizes with Gemcitabine in Pancreatic Cancer.

Pancreatic cancer (PC) is one of the most lethal, chemoresistant malignancies and it is of paramount importance to find more effective therapeutic agents. Repurposing of non-anticancer drugs may expand the repertoire of effective molecules. Studies on repurposing of benzimidazole-based anthelmintics in PC and on their interaction with agents approved for PC therapy are lacking. We analyzed the effects of four Food and Drug Administration (FDA)-approved benzimidazoles on AsPC-1 and Capan-2 pancreatic cancer cell line viability. Notably, parbendazole was the most potent benzimidazole affecting PC cell viability, with half maximal inhibitory concentration (IC50) values in the nanomolar range. The drug markedly inhibited proliferation, clonogenicity and migration of PC cell lines through mechanisms involving alteration of microtubule organization and formation of irregular mitotic spindles. Moreover, parbendazole interfered with cell cycle progression promoting G2/M arrest, followed by the emergence of enlarged, polyploid cells. These abnormalities, suggesting a mitotic catastrophe, culminated in PC cell apoptosis, are also associated with DNA damage in PC cell lines. Remarkably, combinations of parbendazole with gemcitabine, a drug employed as first-line treatment in PC, synergistically decreased PC cell viability. In conclusion, this is the first study providing evidence that parbendazole as a single agent, or in combination with gemcitabine, is a repurposing candidate in the currently dismal PC therapy.

Synthesis of novel benzothiazole amides: Evaluation of PPAR activity and anti-proliferative effects in paraganglioma, pancreatic and colorectal cancer cell lines.

The reduced activation of PPARs has a positive impact on cancer cell growth and viability in multiple preclinical tumor models, suggesting a new therapeutic potential for PPAR antagonists. In the present study, the benzothiazole amides 2a-g were synthesized and their activities on PPARs were investigated. Transactivation assay showed a moderate activity of the novel compounds as PPARα antagonists. Notably, in cellular assays they exhibited cytotoxicity in pancreatic, colorectal and paraganglioma cancer cells overexpressing PPARα. In particular, compound 2b showed the most remarkable inhibition of viability (greater than 90%) in two paraganglioma cell lines, with IC50 values in the low micromolar range. In addition, 2b markedly impaired colony formation capacity in the same cells. Taken together, these results show a relevant anti-proliferative potential of compound 2b, which appears particularly effective in paraganglioma, a rare tumor poorly responsive to chemotherapy.

Novel Phenyldiazenyl Fibrate Analogues as PPAR α/γ/δ Pan-Agonists for the Amelioration of Metabolic Syndrome.

The development of PPARα/γ dual or PPARα/γ/δ pan-agonists could represent an efficacious approach for a simultaneous pharmacological intervention on carbohydrate and lipid metabolism. Two series of new phenyldiazenyl fibrate derivatives of GL479, a previously reported PPARα/γ dual agonist, were synthesized and tested. Compound 12a was identified as a PPAR pan-agonist with moderate and balanced activity on the three PPAR isoforms (α, γ, δ). Moreover, docking experiments showed that 12a adopts a different binding mode in PPARγ compared to PPARα or PPARδ, providing a structural basis for further structure-guided design of PPAR pan-agonists. The beneficial effects of 12a were evaluated both in vitro, on the expression of PPAR target key metabolic genes, and ex vivo in two rat tissue inflammatory models. The obtained results allow considering this compound as an interesting lead for the development of a new class of PPAR pan-agonists endowed with an activation profile exploitable for therapy of metabolic syndrome.

Effects of dichloroacetate as single agent or in combination with GW6471 and metformin in paraganglioma cells.

Paragangliomas (PGLs) are infiltrating autonomic nervous system tumors that cause important morbidity. At present, surgery is the only effective therapeutic option for this rare tumor. Thus, new agents for PGL treatment should be identified. Using unique PGL cell models established in our laboratory, we evaluated the effect of dichloroacetate (DCA) as single agent or in a novel combination with other metabolic drugs, including GW6471 and metformin. DCA and metformin had not been tested before in PGL. DCA reduced PGL cell viability and growth through mechanisms involving reactivation of PDH complex leading to promotion of oxidative metabolism, with lowering of lactate and enhanced ROS production. This resulted in cell cycle inhibition and induction of apoptosis in PGL cells, as shown by flow cytometry and immunoblot analyses. Moreover, DCA drastically impaired clonogenic activity and migration of PGL cells. Also metformin reduced PGL cell viability as single agent and the combinations of DCA, GW6471 and metformin had strong effects on cell viability. Furthermore, combined treatments had drastic and synergistic effects on clonogenic ability. In conclusion, DCA, GW6471 and metformin as single agents and in combination appear to have promising antitumor effects in unique cell models of PGL.