New Smoothened ligands based on the purine scaffold as potential agents for treating pancreatic cancer.

Aberrant activation of the Hedgehog (Hh) signalling pathway has been associated with the development and progression of pancreatic cancer. For this reason, blockade of Hh pathway by inhibitors targeting the G protein-coupled receptor Smoothened (SMO) has been considered as a therapeutic target for the treatment of this cancer. In our previous work, we obtained a new SMO ligand based on a purine scaffold (compound I), which showed interesting antitumor activity in several cancer cell lines. In this work, we report the design and synthesis of 17 new purine derivatives, some of which showed high cytotoxic effect on Mia-PaCa-2 (Hh-dependent pancreatic cancer cell lines) and low toxicity on non-neoplastic HEK-293 cells compared with gemcitabine, such as 8f, 8g and 8h (IC50 = 4.56, 4.11 and 3.08 µM, respectively). Two of these purines also showed their ability to bind to SMO through NanoBRET assays (pKi = 5.17 for 8f and 5.01 for 8h), with higher affinities to compound I (pKi = 1.51). In addition, docking studies provided insight the purine substitution pattern is related to the affinity on SMO. Finally, studies of Hh inhibition for selected purines, using a transcriptional functional assay based on luciferase activity in NIH3T3 Shh-Light II cells, demonstrated that 8g reduced GLI activity with a IC50 = 6.4 µM as well as diminished the expression of Hh target genes in two specific Hh-dependent cell models, Med1 cells and Ptch1-/- mouse embryonic fibroblasts. Therefore, our results provide a platform for the design of SMO ligands that could be potential selective cytotoxic agents for the treatment of pancreatic cancer.

Atypical phosphatase DUSP11 inhibition promotes nc886 expression and potentiates gemcitabine-mediated cell death through NF-kB modulation.

Pancreatic ductal adenocarcinoma (PDAC) represents one of the deadliest cancers among all solid tumors. First-line treatment relies on gemcitabine (Gem) and despite treatment improvements, refractoriness remains a universal challenge. Attempts to decipher how feedback-loops control signaling pathways towards drug resistance have gained attention in recent years, particularly focused on the role of phosphatases. In this study, a CRISPR/Cas9-based phenotypic screen was performed to identify members from the dual-specificity phosphatases (DUSP) family potentially acting on Gem response in PDAC cells. The approach revealed the atypical RNA phosphatase DUSP11 as a potential target, whose inhibition creates vulnerability of PDAC cells to Gem. DUSP11 genetic inhibition impaired cell survival and promoted apoptosis, synergistically enhancing Gem cytotoxicity. In silico transcriptome analysis of RNA-seq data from PDAC human samples identified NF-ĸB signaling pathway highly correlated with DUSP11 upregulation. Consistently, Gem-induced NF-ĸB phosphorylation was blocked upon DUSP11 inhibition in vitro. Mechanistically, we found that DUSP11 directly impacts nc886 expression and modulates PKR-NF-ĸB signaling cascade after Gem exposure in PDAC cells resulting in resistance to Gem-induced cell death. In conclusion, this study provides new insights on DUSP11 role in RNA biology and Gem response in PDAC cells.

Rutinosides-derived from Sarocladium strictum 6-O-α-rhamnosyl-ß-glucosidase show enhanced anti-tumoral activity in pancreatic cancer cells.

BACKGROUND: Low targeting efficacy and high toxicity continue to be challenges in Oncology. A promising strategy is the glycosylation of chemotherapeutic agents to improve their pharmacodynamics and anti-tumoral activity. Herein, we provide evidence of a novel approach using diglycosidases from fungi of the Hypocreales order to obtain novel rutinose-conjugates therapeutic agents with enhanced anti-tumoral capacity. RESULTS: Screening for diglycosidase activity in twenty-eight strains of the genetically related genera Acremonium and Sarocladium identified 6-O-α-rhamnosyl-ß-glucosidase (αRßG) of Sarocladium strictum DMic 093557 as candidate enzyme for our studies. Biochemically characterization shows that αRßG has the ability to transglycosylate bulky OH-acceptors, including bioactive compounds. Interestingly, rutinoside-derivatives of phloroglucinol (PR) resorcinol (RR) and 4-methylumbelliferone (4MUR) displayed higher growth inhibitory activity on pancreatic cancer cells than the respective aglycones without significant affecting normal pancreatic epithelial cells. PR exhibited the highest efficacy with an IC50 of 0.89 mM, followed by RR with an IC50 of 1.67 mM, and 4MUR with an IC50 of 2.4 mM, whereas the respective aglycones displayed higher IC50 values: 4.69 mM for phloroglucinol, 5.90 mM for resorcinol, and 4.8 mM for 4-methylumbelliferone. Further, glycoconjugates significantly sensitized pancreatic cancer cells to the standard of care chemotherapy agent gemcitabine. CONCLUSIONS: αRßG from S. strictum transglycosylate-based approach to synthesize rutinosides represents a suitable option to enhance the anti-proliferative effect of bioactive compounds. This finding opens up new possibilities for developing more effective therapies for pancreatic cancer and other solid malignancies.

Calix[6]arene dismantles extracellular vesicle biogenesis and metalloproteinases that support pancreatic cancer hallmarks.

Many challenges are faced in pancreatic cancer treatment due to late diagnosis and poor prognosis because of high recurrence and metastasis. Extracellular vesicles (EVs) and matrix metalloproteinases (MMPs), besides acting in intercellular communication, are key players in the cancer cell plasticity responsible for initiating metastasis. Therefore, these entities provide valuable targets for the development of better treatments. In this context, this study aimed to evaluate the potential of calix[6]arene to disturb the release of EVs and the activity of MMPs in pancreatic cancer cells. We found a correlation between the endocytic-associated mediators and the prognosis of pancreatic cancer patients. We observed a more active EV machinery in the pancreatic cancer cell line PANC-1, which was reduced three-fold by treatment with calix[6]arene at subtoxic concentration (5 µM; p ã€ˆ0,001). We observed the modulation of 186 microRNAs (164 miRNAs upregulated and 22 miRNAs downregulated) upon calix[6]arene treatment. Interestingly, some of them as miR-4443 and miR-3909, regulates genes HIF1A e KIF13A that are well known to play a role in transport of vesicles. Furthermore, Calix[6]arene downmodulated matrix metalloproteinases (MMPs) -2 and - 9 and disturbed the viability of pancreatic organoids which recapitulate the cellular heterogeneity, structure, and functions of primary tissues. Our findings shed new insights on calix[6]arene's antitumor mechanism, including its intracellular effects on vesicle production and trafficking, as well as MMP activity, which may harm the tumor microenvironment and contribute to a reduction in cancer cell dissemination, which is one of the challenges associated with high mortality in pancreatic cancer.

Chloroxine inhibits pancreatic cancer progression through targeted antagonization of the PI3K/AKT/mTOR signaling pathway.

BACKGROUND: Patients with pancreatic cancer have a dismal prognosis due to tumor cell infiltration and metastasis. Many reports have documented that EMT and PI3K-AKT-mTOR axis control pancreatic cancer cell infiltration and metastasis. Chloroxine is an artificially synthesized antibacterial compound that demonstrated anti-pancreatic cancer effects in our previous drug-screening trial. We have explored the impact of chloroxine on pancreatic cancer growth, infiltration, migration, and apoptosis. METHODS: The proliferation of pancreatic cancer cell lines (PCCs) treated with chloroxine was assessed through real-time cell analysis (RTCA), colony formation assay, CCK-8 assay, as well as immunofluorescence. Chloroxine effects on the infiltrative and migratory capacities of PCCs were assessed via Transwell invasion and scratch experiments. To assess the contents of EMT- and apoptosis-associated proteins in tumor cells, we adopted Western immunoblotting as well as immunofluorescence assays, and flow cytometry to determine chloroxine effects on PCCs apoptosis. The in vivo chloroxine antineoplastic effects were explored in nude mice xenografts. RESULTS: Chloroxine repressed pancreatic cancer cell growth, migration, and infiltration in vitro, as well as in vivo, and stimulated apoptosis of the PCCs. Chloroxine appeared to inhibit PCC growth by Ki67 downregulation; this targeted and inhibited aberrant stimulation of the PI3K-AKT-mTOR signaling cascade, triggered apoptosis in PCC via mitochondria-dependent apoptosis, and modulated the EMT to inhibit PCC infiltration and migration. CONCLUSIONS: Chloroxine targeted and inhibited the PI3K-AKT-mTOR cascade to repress PCCs growth, migration, as well as invasion, and triggered cellular apoptosis. Therefore, chloroxine may constitute a potential antineoplastic drug for the treatment of pancreatic cancer.

Neoadjuvant Chemotherapy Versus Upfront Surgery for Resectable Pancreatic Adenocarcinoma: An Updated Nationwide Study.

OBJECTIVE: The objective of this study was to assess the association of survival with neoadjuvant chemotherapy (NAC) in resectable pancreatic adenocarcinoma (PDAC). BACKGROUND: The early control of potential micrometastases and patient selection using NAC has been advocated for patients with PDAC. However, the role of NAC for resectable PDAC remains unclear. METHODS: Patients with clinical T1 and T2 PDAC were identified in the National Cancer Database from 2010 to 2017. Kaplan-Meier estimates, and Cox regression models were used to compare survival. To address immortal time bias, landmark analysis was performed. Interactions between preoperative factors and NAC were investigated in subgroup analyses. A propensity score analysis was performed to compare survival between multiagent NAC and upfront surgery. RESULTS: In total, 4041 patients were treated with upfront surgery and 1,175 patients were treated with NAC (79.4% multiagent NAC, 20.6% single-agent NAC). Using a landmark time of 6 months after diagnosis, patients treated with multiagent NAC had longer median overall survival compared with upfront surgery and single-agent NAC. (35.8 vs 27.1 vs 27.4 mo). Multiagent NAC was associated with lower mortality rates compared with upfront surgery (adjusted hazard ratio, 0.77; 95% CI, 0.70-0.85), whereas single-agent NAC was not. The association of survival with multiagent NAC were consistent in analyses using the matched data sets. Interaction analysis revealed that the association between multiagent NAC and a lower mortality rate did not significantly differ across age, facility type, tumor location, CA 19-9 levels, and clinical T/N stages. CONCLUSIONS: The findings suggest that multiagent NAC followed by resection is associated with improved survival compared with upfront surgery.

Association of Pancreatic Adenocarcinoma Location With DNA Damage Response Status and Response to Platinum-Based Therapy.

PURPOSE: Pancreatic adenocarcinoma is an aggressive disease with poor clinical outcomes. Primary pancreatic tumors originating from the head of the pancreas (H) have different prognostic implications than tumors arising from the body and tail (BT). This is thought to be largely due to anatomic differences, as molecular underpinnings of survival have not been fully explored. We hypothesized that differences in the primary site of H and BT tumors might account for differential molecular outcomes and response to chemotherapy. METHODS: Retrospective data from a single high-volume academic center were analyzed for hypothesis generation. A large-scale, real-world retrospective cohort of 2015 patients with next-generation sequencing (NGS) results were analyzed from a Real-World Evidence database. Progression-free survival (PFS) was evaluated from the initiation of first line of therapy for advanced disease until discontinuation because of progression. HR and P values were computed via Cox regression between first-line FOLFIRINOX and gemcitabine/nanoparticle albumin-bound (gem/nab) paclitaxel. Differences in frequencies of genomic alterations between H and BT were analyzed by Fisher's exact test. RESULTS: Genomic alterations in the DNA damage response (DDR) pathway (such as BRCA1, BRCA2, and PALB2) were enriched (unadjusted P value = .00244) in BT tumors (21.7% of 618) relative to H tumors (15.6% of 942) where BRCA2 was a top contributor within this pathway. Median PFS in BT tumors on first-line FOLFIRINOX was longer than first line gem/nab-paclitaxel (P = .006393); this difference was not identified in H tumors (P = .5546). CONCLUSION: DDR pathway alterations including BRCA1/BRCA2/PALB2 are known predictors of increased benefit from platinum-based chemotherapy. NGS testing for germline and somatic mutations remains important in pancreatic ductal adenocarcinoma, especially in BT tumors where DDR pathway alterations may be more common than in H tumors.

Synergistic effect of antagonists to KRas4B/PDE6 molecular complex in pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) has the worst prognosis among all human cancers as it is highly resistant to chemotherapy. K-Ras mutations usually trigger the development and progression of PDAC. We hypothesized that compounds stabilizing the KRas4B/PDE6δ complex could serve as PDAC treatments. Using in silico approaches, we identified the small molecules C14 and P8 that reduced K-Ras activation in primary PDAC cells. Importantly, C14 and P8 significantly prevented tumor growth in patient-derived xenotransplants. Combined treatment with C14 and P8 strongly increased cytotoxicity in PDAC cell lines and primary cultures and showed strong synergistic antineoplastic effects in preclinical murine PDAC models that were superior to conventional therapeutics without causing side effects. Mechanistically, C14 and P8 reduced tumor growth by inhibiting AKT and ERK signaling downstream of K-RAS leading to apoptosis, specifically in PDAC cells. Thus, combined treatment with C14 and P8 may be a superior pharmaceutical strategy to improve the outcome of PDAC.

A proteomic signature and potential pharmacological opportunities in the adaptive resistance to MEK and PI3K kinase inhibition in pancreatic cancer cells.

Pancreatic cancer is one of the most lethal cancer types and is becoming a leading cause of cancer-related deaths. The limited benefit offered by chemotherapy agents has propelled the search for alternative approaches that target specific molecular drivers of cancer growth and progression. Mutant KRas and effector pathways Raf/MEK/ERK and PI3K/Akt are key players in pancreatic cancer; however, preclinical studies have shown adaptive tumour response to combined MEK and PI3K kinase inhibition leading to treatment resistance. There is a critical unmet need to decipher the molecular basis underlying adaptation to this targeted approach. Here, we aimed to identify common protein expression alterations associated with adaptive resistance in KRas-mutant pancreatic cancer cells, and test if it can be overcome by selected already available small molecule drugs. We found a group of 14 proteins with common expression change in resistant cells, including KRas, caveolin-1, filamin-a, eplin, IGF2R and cytokeratins CK-8, -18 and -19. Notably, several proteins have previously been observed in pancreatic cancer cells with intrinsic resistance to the combined kinase inhibition treatment, suggesting a proteomic signature. We also found that resistant cells are sensitive to small molecule drugs ERK inhibitor GDC-0994, S6K1 inhibitor DG2 and statins.

Therapy Sequencing in Patients With Advanced Neuroendocrine Neoplasms.

Neuroendocrine neoplasms (NENs) comprise a beautifully complicated, exciting landscape of histologies and clinical behaviors. However, the nuanced complexity of low- and high-grade variants can easily overwhelm both patients and providers. In this chapter, we review the ever-expanding literature on both functioning and nonfunctioning small bowel and pancreatic NENs, touching on somatostatin analogs, hepatic-directed therapies, small molecules, radiopharmaceuticals, immunotherapy, cytotoxic chemotherapy, and new promising agents. Furthermore, we suggest some strategies to address the most challenging scenarios seen in clinical practice, including sequencing of agents, treatment of carcinoid syndrome, and options for well-differentiated high-grade disease.

Advancements in Systemic Therapy for Pancreatic Cancer.

Outcomes for patients with advanced pancreatic cancer have improved in the past 12 years, mainly because of progress made in systemic therapies. New treatment strategies for advanced pancreatic cancer include switch maintenance with cytotoxic therapies, induction maintenance, and the utilization of targeted agents for patients with actionable variants, as well as ongoing development of cytotoxic regimens, such as NALIRIFOX. The activity of immunotherapy has been disappointing to date, but novel combinations and identifying appropriate patient populations may further unlock its potential.

Current Treatment of Potentially Resectable Pancreatic Ductal Adenocarcinoma: A Medical Oncologist's Perspective.

Pancreatic cancer has traditionally been associated with a dismal prognosis, even in early stages of the disease. In recent years, the introduction of newer generation chemotherapy regimens in the adjuvant setting has improved the survival of patients treated with upfront resection. However, there are multiple theoretical advantages to deliver early systemic therapy in patients with localized pancreatic cancer. So far, the evidence supports the use of neoadjuvant therapy for patients with borderline resectable pancreatic cancer. The benefit of this treatment sequence for patients with resectable disease remains elusive. In this review, we summarize the data on adjuvant therapy for pancreatic cancer and describe which evidence backs the use of neoadjuvant therapy. Additionally, we address important issues faced in clinical practice when treating patients with localized pancreatic cancer.

Impact of Granulocyte Colony-Stimulating Factor (G-CSF) on the Outcomes of Patients With Metastatic Pancreatic Adenocarcinoma (MPA) During First-Line Treatment With FOLFIRINOX: A Single-Center Retrospective Analysis.

INTRODUCTION: The role of primary prophylaxis (PP) with granulocyte colony-stimulating factor (G-CSF) for patients with metastatic pancreatic adenocarcinoma (MPA) treated with FOLFIRINOX is unknown. We aimed to compare the frequencies of grades 3 or 4 neutropenia (G3/4N) and febrile neutropenia (FN) and survival outcomes according to the use of PP. METHODS: This is a retrospective study. We included patients with pathologically confirmed MPA treated with FOLFIRINOX in first-line. Patients who received primary prophylaxis (PP group) were compared to patients who received secondary or no G-CSF (no-PP group). Overall survival (OS) and progression-free survival (PFS) were evaluated using the standard Cox proportional hazard model. To account for potential biases, we performed sensitivity analyses excluding patients who received secondary prophilaxis and treating G-CSF as a time-dependent covariate in extended Cox proportional hazard models. RESULTS: The study population consisted of 123 patients. PP was used by 75 patients (61.0%). G3/4 N occurred more frequently among patients without PP (10.7 vs 41.7%; P < .001). There was no difference in the frequency of FN between groups (5.3 vs 8.3%; P = .710). In multivariate analysis, PP was associated with a trend toward improved OS (HR = .66; 95% confidence interval [95% CI] .41 - 1.07; P = .094). In the multivariate model excluding patients with secondary prophylaxis (HR = .54; 95% CI 0.32 - .91; P = .022) and in the time-dependent model (HR = .47; 95% CI 0.28 - .80; P = .005), PP was associated with statistically superior OS. CONCLUSIONS: Despite the reduction in the frequency of G3/4N, the risk of FN among patients treated with FOLFIRINOX without G-CSF is too low to justify its use in a routine basis. However, given the potential of G-CSF to improve survival in this setting, further studies are warranted to assess its role during treatment with FOLFIRINOX for patients with MPA.

Clinical characteristics of 662 patients with pancreatic neuroendocrine tumors receiving antitumoral therapy.

Pancreatic neuroendocrine neoplasia constitute an important subentity of the gastroenteropancreatic neuroendocrine neoplasms accounting for up to 15% of all neuroendocrine neoplasm. Prognosis and oncological behavior of pancreatic neuroendocrine tumors (pNETs) is extremely heterogenous and dependent on the specific tumor stage and differentiation. However, systematic data on the specific epidemiology of pNET are scarce. We identified 662 patients with pNET within the Oncology Dynamics database (IQVIA). Patients were derived from 4 European countries (Germany, France, UK, Spain), 3 Asian countries (Japan, China, South Korea) and 2 South American countries (Mexico and Brazil) and with regard to major patient and tumor related characteristics including patients' age, sex, tumor stage, tumor grading, and differentiation. The mean age of the study cohort was 62 years (SD 12 years) with 53.9.1% of all patients being male. The majority of patients had an Eastern co-operative of Oncology Group 1 performance status (63.3%). The most common Union international contre le cancer tumor stage was stage IV (85%) with liver metastases (89.0%) representing the most common site of extra-pancreatic tumor manifestation. The majority of all patients displayed well or moderate tumor differentiation (9.6% of patients had a Ki-67 expression below 2%. 67.6% of pNET patients had a Ki-67 expression between 2 and 20% and 22.8% of patients showed an expression above 20%). At time point of diagnoses, 93.1% of patients were classified as inoperable. Of note, 93.9 % of patients received systemic anti-tumoral therapy in palliative intention, while treatment was administered in 1.4 % of cases in neoadjuvant and in 4.7% of cases in in an adjuvant setting. Biological therapy was applied to 39.4% of patients, followed by targeted therapies (31.4%) and chemotherapy. Pancreatic neuroendocrine neoplasia are diagnosed in advanced tumor stages, globally. Systemic treatment was the most commonly used treatment modality. Such data may help to better understand the specific epidemiology of pNET worldwide.

Características y resultados del tratamiento aplicado a los pacientes con cáncer de páncreas / Rejuvenation Surgery with High-Superficial Musculoaponeurotic System Flap

Introducción: El cáncer de páncreas mantiene un pronóstico ominoso a pesar de los avances en técnicas quirúrgicas y cuidados perioperatorios. Objetivo: Caracterizar los resultados del tratamiento aplicado a los pacientes con cáncer de páncreas. Métodos: Se realizó un estudio observacional, descriptivo y transversal de una serie de 70 pacientes con diagnóstico de cáncer de páncreas. Se estudiaron las variables: localización, tamaño del tumor, procedimiento quirúrgico, estadificación preoperatoria, diagnóstico histológico, estancia hospitalaria, complicaciones posoperatorias y estado al egreso, mediante el análisis de frecuencias absolutas, relativas y la media así como la prueba de ji al cuadrado y el IC 95 por ciento. Resultados: El procedimiento quirúrgico más frecuente fue derivativo en 47 enfermos (67,1 por ciento). La operación de Whipple se realizó en 10 pacientes (14,3 por ciento) con tumores localizados en la cabeza del páncreas y la pancreatectomía corporocaudal en 11 (15,7 por ciento) con tumores de cuerpo y cola del páncreas. La mayoría correspondió a los estadios III y IV. El 47,1 por ciento de los pacientes presentó un adenocarcinoma poco diferenciado. La estadía fluctuó entre 15 y 30 días en el 54,3 por ciento de la serie. Las complicaciones se presentaron en 19 enfermos (27,1 por ciento). Fallecieron 15 pacientes (21,4 por ciento) del total. Conclusiones: El tratamiento debe ser individualizado mediante equipos multidisciplinarios, con protocolos de actuación uniformes en cada institución que permita realizar estudios multicéntricos, con el objetivo de obtener estadísticas propias en aras de disminuir la morbilidad y la mortalidad, así como aumentar la calidad de vida de estos pacientes(AU)

Introduction: Facial rhytidectomy is the technique for correcting facial aging features, but they are becoming increasingly complex due to the incorporation of deeper planes in the process. The superficial musculoaponeurotic system techniques have the advantage of providing a greater degree of naturalness and permanence in time. Objective: To evaluate the effectiveness of the high-superficial musculoaponeurotic system technique for facial rejuvenation. Methods: A prospective and longitudinal case series study was carried out in the plastic surgery service of Hospital General Universitario "Vladimir Ilich Lenin" with patients who requested facial rejuvenation and were treated with the high-superficial musculoaponeurotic system technique, from January 1, 2018 to June 30, 2020. The variables age, sex, skin type, degree of aging, operative complications, patient satisfaction and aesthetic outcomes were studied. Results: The female sex predominated, together with the age group 50-59 years, the degrees of aging II and III, as well as white and light brown skin colors, while the most frequent operative complication was wound dehiscence of the suture line at the auricle root. The patients' satisfaction with the aesthetic outcomes of the surgical intervention was verified and the aesthetic outcomes was assessed as favorable in 100 percent of the cases for the used surgical technique. Conclusions: The high-superficial musculoaponeurotic system surgical technique for rhytidectomy offers harmonic, long-lasting outcomes with a low percentage of complications, making it a valuable alternative for patients(AU)

The effects of thymoquinone on pancreatic cancer and immune cells.

OBJECTIVES: Black cumin is widely used as a spice and as a traditional treatment. The active ingredient in black cumin seeds is thymoquinone. Thymoquinone has shown anticancer effects in some cancers. We planned to investigate its anticancer effect on pancreatic cancer cell lines. METHODS: Thymoquinone chemical component in various doses was prepared and inoculated on pancreatic cancer cell culture, healthy mesenchymal stem cells, and peripheral blood mononuclear cell culture. IC50 values were calculated by absorbance data and measuring cell viability by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide staining of cells incubated with thymoquinone at 24, 48, and 72 h. RESULTS: There was dose-related cytotoxicity. Maximal cytotoxicity was observed at 24 h and 100 µM thymoquinone concentrations in pancreatic cancer cell culture and mesenchymal stem cells. Any concentration of thymoquinone was not cytotoxic to peripheral blood mononuclear cell. Thymoquinone even caused proliferation at a concentration of 6.25 µM. CONCLUSIONS: Since the cytotoxic concentration of thymoquinone on pancreatic cancer cell culture and mesenchymal stem cells is the same, it is not appropriate to use thymoquinone to achieve cytotoxicity in pancreatic cancer. However, since thymoquinone provides proliferation in peripheral blood mononuclear cell at a noncytotoxic dose, it may have an immune activator effect. Therefore, in vivo studies are needed to investigate the effect of thymoquinone on the immune system.

The antitumor activity of hPRDX5 against pancreatic cancer and the possible mechanisms.

Recombinant human peroxiredoxin-5 (hPRDX5), isolated from anti-cancer bioactive peptide (ACBPs), shows a homology of 89% with goat peroxiredoxin-5 (gPRDX5) and is reported to display anti-tumor activity in vivo. Herein, we explored the effect of hPRDX5 and the responsible mechanism in treating pancreatic cancer. Tumor-bearing mice were randomly divided into normal PBS group and treatment group (n=5; 10 mg/kg hPRDX5). Flow cytometry was employed to examine lymphocytes, myeloid-derived suppressor cell subsets, and the function proteins of natural killer (NK) cells in peripheral blood, spleen, and tumor tissues of mice. Western blot was used to measure the protein expressions of the key nodes in TLR4-MAPK-NF-κB signaling pathway. The rate of tumor suppression was 57.6% at a 10 mg/kg dose in orthotopic transplanted tumor mice. Moreover, the population of CD3+CD4+T cells, NK cells, and CD3+CD8+T cells was significantly increased in the tumor tissue of the hPRDX5 group, while the proportion of granulocytic-myeloid-derived suppressor cells decreased slightly. In addition, after treatment with hPRDX5, the percentage of NK cells in blood increased more than 4-fold. Our findings indicated that hPRDX5 effectively suppressed pancreatic cancer possibly via the TLR4-MAPK-NF-κB signaling cascade; hence hPRDX5 could be a prospective immunotherapy candidate for treating pancreatic cancer.

Combination immunotherapy for pancreatic cancer: challenges and future considerations.

INTRODUCTION: Immune checkpoint inhibitors (ICI) have not yielded significant efficacy in pancreatic ductal adenocarcinoma (PDA), despite the role of the innate and adaptive immune systems on progression and survival. However, recently identified pathways have identified new targets and generated promising clinical investigations into promoting an effective immune-mediated antitumor response in PDA. AREAS COVERED: We review biological mechanisms associated with immunotherapy resistance and outline strategies for therapeutic combinations with established and novel therapies in PDA. EXPERT OPINION: Pancreatic cancers rarely benefit from treatment with ICI due to an immunosuppressive tumor microenvironment (TME). New understandings of factors associated with the suppressive TME include low- and poor-quality neoantigens, constrained effector T cells infiltration, and the presence of a dense, suppressive myeloid cell population. These findings have been translated into new clinical investigations evaluating novel therapies in combination with ICI and/or standard systemic chemotherapy and radiotherapy. The epithelial, immune, and stromal compartments are intricately related in PDA, and the framework for successful targeting of this disease requires a comprehensive and personalized approach.