Identification of exosomal miR-484 role in reprogramming mitochondrial metabolism in pancreatic cancer through Wnt/MAPK axis control.

The microRNAs (miRNAs) are potent regulators of tumorigenesis in various cancers, especially pancreatic cancer. The abnormal expression of miRNAs can be observed in tumor cells. Noteworthy, miRNAs could be transferred by exosomes as small extracellular vesicles in regulation of carcinogenesis. This research focused on exploring the roles and mechanisms of exosomal miR-484, derived from human bone marrow mesenchymal stem cells (hBMSCs), in the context of molecular interactions and regulation of mitochondrial metabolism. Exosomes were isolated for the examination of miR-484 expression. The impacts of hBMSCs-derived exosomal miR-484 on pancreatic cancer cells were studied using various assays. Evaluation of mitochondrial function and metabolism was performed. Wnt/MAPK pathway-related protein expression was assessed, and an in vivo tumor xenograft model was utilized to examine the functions. Our findings demonstrated a decreased miR-484 expression in pancreatic cancer cells. However, hBMSCs-derived exosomal miR-484 inhibited the proliferation and migration of these cells, while inducing apoptosis. Moreover, miR-484 led to an upsurge in reactive oxygen species production, a decrease in ATP levels, and a disruption in mitochondrial metabolism. In vivo analyses showed that hBMSCs-derived exosomal miR-484 lessened tumor size and weight, while also suppressing the expression of mitochondrial biomarkers. Further, there was a decline in ß-catenin and p-p38 protein levels both in vitro and in vivo. The addition of LiCl restored the disrupted mitochondrial metabolism. Conclusively, our results suggest that hBMSCs-derived exosomal miR-484 mitigates the malignant transformation and mitochondrial metabolism of pancreatic cancer by deactivating the Wnt/MAPK pathway.

A pyroptosis-related gene signature predicts prognosis and immune microenvironment in hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is a highly malignant tumor with a very poor prognosis. Pyroptosis is an inflammatory form of cell death and plays an important role in cancer development. The prognostic value of pyroptosis-related genes (PRGs) in HCC has not been studied extensively. METHODS: Unsupervised consensus clustering analysis was performed to identify two subtypes based on the expression profiles of prognostic PRGs in the The Cancer Genome Atlas (TCGA) database, and the differences between the two subtypes were compared. A prognostic model based on four PRGs was established by further least absolute shrinkage and selection operator (LASSO) Cox regression analysis and multivariate Cox regression analysis. RESULTS: Two subtypes (clusters 1 and 2) were identified by consensus clustering based on prognostic PRGs in HCC. Survival outcomes, biological function, genomic alterations, immune cell infiltration, and immune checkpoint genes were compared between the subtypes. Cluster 2 had a worse survival outcome than cluster 1. Cluster 2 was enriched for hallmarks of cancer progression, TP53 mutation, tumor-promoting immune cells, and immune checkpoint genes, which may contribute to the poor prognosis. A prognostic risk signature that predicted the overall survival (OS) of patients was constructed and validated. Consequently, a risk score was calculated for each patient. Combined with the clinical characteristics, the risk score was found to be an independent prognostic factor for survival of HCC patients. Further analysis revealed that the risk score was closely associated with the levels of immune cell infiltration and the expression profiles of immune checkpoint genes. CONCLUSIONS: Collectively, our study established a prognostic risk signature for HCC and revealed a significant correlation between pyroptosis and the HCC immune microenvironment.

Pancreatic cancer-derived exosomes induce apoptosis of T lymphocytes through the p38 MAPK-mediated endoplasmic reticulum stress.

Pancreatic cancer is the fourth most lethal malignancy and is characterized by poor immunogenicity. Pancreatic cancer cells have various strategies to suppress host immune response, evade immune defenses, and facilitate tumor growth and development. As a mode of long-range intercellular communication, cancer-derived exosomes contribute to impairment of the immune system. However, the mechanisms that induce changes in the activities of signal transduction pathways in immune cells, which are influenced by tumor-derived exosomes, are poorly understood. We (1) treated peripheral T lymphocytes with pancreatic cancer-derived exosomes, tagged CD63 with tdTomato, to trace exosome transfer from pancreatic cancer cells to T lymphocytes; (2) carried out a cytotoxicity assay of exosome-treated T lymphocytes using the Real Time Cellular Analysis system; (3) performed RNA sequencing and gene set enrichment analysis to explore the pivotal signaling pathway that mediates apoptosis in exosome-treated T lymphocytes; and (4) demonstrated the role of p38 mitogen-activated protein kinase (MAPK) and endoplasmic reticulum (ER) stress in exosome-induced T-lymphocyte apoptosis. In conclusion, these results indicate that pancreatic cancer cells secrete exosomes, which are taken up by T lymphocytes to activate p38 MAPK, and then induce ER stress-mediated apoptosis, ultimately causing immunosuppression.

IFN-γ down-regulates the PD-1 expression and assist nivolumab in PD-1-blockade effect on CD8+ T-lymphocytes in pancreatic cancer.

BACKGROUND: Pancreatic cancer is characterized by a highly immunosuppressive tumor microenvironment and evasion of immune surveillance. Although programmed cell death 1 receptor (PD-1) blockade has achieved certain success in immunogenic cancers, the responses to the PD-1 antibody are not effective or sustained in patients with pancreatic cancer. METHODS: Firstly, PD-1 expressions on peripheral CD8+ T-lymphocytes of patients with pancreatic cancer and healthy donors were measured. In in vitro study, peripheral T-lymphocytes were isolated and treated with nivolumab and/or interferon-γ, and next, PD-1-blockade effects, proliferations, cytokine secretions and cytotoxic activities were tested after different treatments. In in vivo study, mice bearing subcutaneous pancreatic cancer cell lines were treated with induced T-lymphocytes and tumor sizes were measured. RESULTS: PD-1 protein expression is increased on peripheral CD8+ T cells in patients with pancreatic ductal adenocarcinoma compared with that in health donor. PD-1 expression on CD8+ T-lymphocytes was decreased by nivolumab in a concentration-dependent manner in vitro. IFN-γ could directly down-regulate expression of PD-1 in vitro. Furthermore, the combination therapy of nivolumab and IFN-γ resulted in greatest effect of PD-1-blockde (1.73 ± 0.78), compared with IFN-γ along (18.63 ± 0.82) and nivolumab along (13.65 ± 1.22). Moreover, the effects of nivolumab plus IFN-γ largest promoted the T-lymphocytes function of proliferations, cytokine secretions and cytotoxic activities. Most importantly, T-lymphocytes induced by nivolumab plus IFN-γ presented the best repression of tumor growth. CONCLUSIONS: IFN-γ plus a PD-1-blockading agent could enhance the immunologic function and might play a crucial role in effective adoptive transfer treatments of pancreatic cancer.

Flux density measurement of radial magnetic bearing with a rotating rotor based on fiber Bragg grating-giant magnetostrictive material sensors.

The rotational magnetic field of radial magnetic bearings characterizes remarkable time and spatial nonlinearity due to the eddy current and induced electromagnetic field. It is significant to experimentally obtain the features of the rotational magnetic field of the radial magnetic bearings to validate the theoretical analysis and reveal the discipline of a rotational magnetic field. This paper developed thin-slice fiber Bragg grating-giant magnetostrictive material (FBG-GMM) magnetic sensors to measure air-gap flux density of a radial magnetic bearing with a rotating rotor; a radial magnetic bearing test rig was constructed and the rotational magnetic field with different rotation speed was measured. Moreover, the finite element method (FEM) was used to simulate the rotational magnetic field; the measurement results and FEM results were investigated, and it was concluded that the FBG-GMM sensors were capable of measuring the radial magnetic bearing's air gap flux density with a rotating rotor, and the measurement results showed a certain degree of accuracy.

A modified Jarnagin-Blumgart classification better predicts survival for resectable hilar cholangiocarcinoma.

BACKGROUND: Prediction of postoperative survival for hilar cholangiocarcinoma (HCCA) remains difficult although there have been a variety of clinical classification and staging systems. This study was designed to validate and compare some of the major HCCA staging systems in use today. In addition, we sought to build up a new staging system modified from Jarnagin-Blumgart (J-B) classification for HCCA, to predict survival better. METHODS: A total of 154 consecutive cases of HCCA including 95 surgical patients between 2005 and 2014 were enrolled in this study. The clinical and pathological data were recorded retrospectively and three commonly used classification methods: Bismuth-Corlette (B-C) classification, TNM staging, and J-B classification were performed to analyze the correlations with resectability and survival. Chi-square test, Kaplan-Meier analysis, and kappa statistics were used to compare and confirm the relationships between the variables and survival. RESULTS: For all 154 patients, the resection rate of J-B T1 was 68.6% (48/70), higher than that of J-B T2 (44.8%, P = 0.007). J-B T2 also showed a higher resectability than J-B T3 (19.2%, P = 0.025). There was no significant difference in resectability within the groups B-C type and TNM stages. We set up a new staging system based on J-B classification, tumor differentiation, distant metastasis (N2 or M1 of TNM stage), and resection integrality. The total survival predictive accuracy was 69.5% (kappa = 0.547), higher than that of TNM staging and J-B classification. CONCLUSIONS: J-B classification was more useful than B-C classification, while its value for predicting survival did not exceed TNM staging system. The new staging system, based on J-B classification, provides a better method to stratify HCCA patients during the operation.

Pancreatic cancer derived exosomes regulate the expression of TLR4 in dendritic cells via miR-203.

MicroRNAs (miRNAs) are aberrant in many human tumors which can be transferred to immune cells by tumor-derived exosomes. Dendritic cells (DCs) play an important role in activation of immune response. However, the effect of tumor-derived exosomes on toll-like receptor (TLR) in DCs remains unclear. We investigated the influence of pancreatic cancer derived exosomes on TLR4, and downstream cytokines via miR-203. Our results showed that miR-203 expressed in panc-1 cells and exosomes, and upregulated in exosomes-treated DCs. TLR4 decreased after treatment of exosomes and miR-203 mimics, while increased in exosomes-treated DCs by miR-203 inhibitors. But the mRNA level of TLR4 was not significantly different between DCs and exosomes-treated DCs. Tumor necrosis factor-α (TNF-α) and interleukin-12 (IL-12) also decreased under treatment of exosomes and miR-203 mimics, both of which increased in exosomes-treated DCs by miR-203 inhibitors. Collectively, pancreatic cancer derived exosomes downregulate TLR4 and downstream cytokines in DCs via miR-203.

Dimethyl sulfate and diisopropyl sulfate as practical and versatile O-sulfation reagents.

O-Sulfation is a vital post-translational modification in bioactive molecules, yet there are significant challenges with their synthesis. Dialkyl sulfates, such as dimethyl sulfate and diisopropyl sulfate are commonly used as alkylation agents in alkaline conditions, and result in the formation of sulfate byproducts. We report herein a general and robust approach to O-sulfation by harnessing the tunable reactivity of dimethyl sulfate or diisopropyl sulfate under tetrabutylammonium bisulfate activation. The versatility of this O-sulfation protocol is interrogated with a diverse range of alcohols, phenols and N-OH compounds, including carbohydrates, amino acids and natural products. The enhanced electrophilicity of the sulfur atom in dialkyl sulfates, facilitated by the interaction with bisulfate anion (HSO4-), accounts for this pioneering chemical reactivity. We envision that our method will be useful for application in the comprehension of biological functions and discovery of drugs.

Diagnostic plasma small extracellular vesicles miRNA signatures for pancreatic cancer using machine learning methods.

BACKGROUND: Identifying biomarkers may lead to easier detection and a better understanding of pathogenesis of pancreatic ductal adenocarcinoma (PDAC). METHODS: Plasma small extracellular vesicles (sEV) from 106 participants, including 20 healthy controls (HC), 12 chronic pancreatitis (CP) patients, 12 benign pancreatic tumour (BPT) patients, and 58 PDAC patients, were profiled for microRNA (miRNA) sequencing. Three machine learning methods were applied to establish and evaluate the diagnostic model. RESULTS: The plasma sEV miRNA diagnostic signature (d-signature) selected using the three machine learning methods could distinguish PDAC patients from non-PDAC individuals, HC, and benign pancreatic disease (BPD, CP plus BPT) both in training and validation cohort. Combining the d-signature with carbohydrate antigen 19-9 (CA19-9) performed better than with each model alone. Plasma sEV miR-664a-3p was selected by all methods and used to predict PDAC diagnosis with high accuracy combined with CA19-9. Plasma sEV miR-664a-3p was significantly positively associated with the presence of vascular invasion, lower surgery ratio, and poor differentiation. MiR-664a-3p was mainly distributed in the PDAC cancer stroma, including fibers and vessels, and was accompanied by VEGFA expression. Overexpression of miR-664a-3p could promote the epithelial-mesenchymal transition (EMT) and angiogenesis. CONCLUSION: In conclusion, our study demonstrated the potential utility of the sEV-miRNA d-signature in the diagnosis of PDAC via machine learning methods. A novel sEV biomarker, miR-664a-3p, was identified for the diagnosis of PDAC. It can also potentially promote angiogenesis and metastasis, provide insight into PDAC pathogenesis, and reveal novel regulators of this disease.

Analysis of serum exosomal microRNAs and clinicopathologic features of patients with pancreatic adenocarcinoma.

BACKGROUND: Altered expression of serum microRNAs (miRNAs) have been reported to correlate with carcinogenesis and progression of pancreatic adenocarcinoma (PC), but descriptions of serum exosomal miRNAs in PC are still lacking. This study was designed to evaluate serum exosomal miRNA levels in PC patients and to investigate their relationships with clinicopathologic features and prognosis. METHODS: Four miRNAs (miR-17-5p, miR-21, miR-155 and miR-196a) related to PC were selected for examination in our research. Serum miRNA was examined by RT-PCR in a group of 49 patients, including 22 with PCs, 6 with benign pancreatic tumors, 7 with ampullary carcinomas, 6 with chronic pancreatitis and 8 healthy participants. The clinicopathologic data were also collected, and PC patients were classified according to the presence of metastasis, tumor differentiation and advanced stage. RESULTS: There were low expressions of exosomal miR-155 and miR-196a in serum samples of PC patients when U-6 was used as a control. Serum exosomal miR-17-5p was higher in PC patients than in non-PC patients and healthy participants. High levels of miR-17-5p were significantly correlated with metastasis and advanced stage of PC. The serum exosomal miR-21 level in PC was higher than that in the normal and chronic pancreatitis groups, but was not significantly correlated with PC differentiation and tumor stage. CONCLUSIONS: There were high expressions of serum exosomal miR-17-5p and miR-21 in PC patients. Examination of serum exosomal microRNA is a useful serum biomarker for PC diagnosis other than serum-free microRNA. It is postulated that exosomal miR-17-5p participates in the progression of PC.

Sirtuin4 impacts mitochondrial homeostasis in pancreatic cancer cells by reducing the stability of AlkB homolog 1 via deacetylation of the HRD1-SEL1L complex.

Pancreatic ductal adenocarcinoma (PDAC) is a highly malignant tumor with a poor prognosis. As a tumor inhibitor, the specific tumor suppressor mechanism of Sirtuin4(SIRT4) in PDAC remains elusive. In this study, SIRT4 was found to inhibit PDAC by impacting mitochondrial homeostasis. SIRT4 deacetylated lysine 547 of SEL1L and increased the protein level of an E3 ubiquitin ligase HRD1. As a central member of ER-associated protein degradation (ERAD), HRD1-SEL1L complex is recently reported to regulate the mitochondria, though the mechanism is not fully delineated. Here, we found the increase in SEL1L-HRD1 complex decreased the stability of a mitochondrial protein, ALKBH1. Downregulation of ALKBH1 subsequently blocked the transcription of mitochondrial DNA-coded genes, and resulted in mitochondrial damage. Lastly, a putative SIRT4 stimulator, Entinostat, was identified, which upregulated the expression of SIRT4 and effectively inhibited pancreatic cancer in vivo and in vitro.

Post-translational modification of CDK1-STAT3 signaling by fisetin suppresses pancreatic cancer stem cell properties.

BACKGROUND: Pancreatic cancer stem cells (CSCs) promote pancreatic ductal adenocarcinoma (PDAC) tumorigenesis and chemoresistance. Cyclin-dependent kinase 1 (CDK1) plays an important role in tumor initiation in other tumors, but the function of CDK1 in PDAC remains unclear. Fisetin is a bioactive flavonoid with anti-tumor properties in multiple tumors, while its function in CSCs remains elusive. RESULTS: In this study, we demonstrated that CDK1 was correlated with prognosis and was highly expressed in pancreatic cancer tissue and gemcitabine-resistant cells. Silencing CDK1 impaired tumor stemness and reduced a subset of CSCs. We found that fisetin blocked the kinase pocket domain of CDK1 and inhibited pancreatic CSC characteristics. Using acetylation proteomics analysis and phosphorylation array assay, we confirmed that fisetin reduced CDK1 expression and increased CDK1 acetylation at lysine 33 (K33), which resulted in the suppression of CDK1 phosphorylation. Silencing CDK1 or STAT3 suppressed tumor stemness properties, while overexpressing CDK1 or STAT3 showed the opposite effect. Mutation or acetylation of CDK1 at K33 weakened STAT3 phosphorylation at Y705, impairing the expression of stem-related genes and pancreatic cancer stemness. In addition, lack of histone deacetylase 3 (HDAC3), which deacetylates CDK1, contributed to weakening STAT3 phosphorylation by regulating the post-translational modification of CDK1, thereby decreasing the stemness of PDAC. Moreover, our results revealed that fisetin enhanced the effect of gemcitabine through eliminating a subpopulation of pancreatic CSCs by inhibiting the CDK1-STAT3 axis in vitro and in vivo. CONCLUSION: Our findings highlight the role of post-translational modifications of CDK1-STAT3 signaling in maintaining cancer stemness of PDAC, and indicated that targeting the CDK1-STAT3 axis with inhibitors such as fisetin is a potential therapeutic strategy to diminish drug resistance and eliminate PDAC.

Case Report: Idiopathic Traumatic Neuroma of the Gallbladder Without Previous Surgery.

Traumatic neuroma mostly results from nerve injury caused by surgery or trauma. Traumatic neuroma of the gallbladder without prior abdominal surgery is extremely rare, and we termed it "idiopathic traumatic neuroma of the gallbladder." Due to its rarity and a lack of specific clinical and radiological features, it is most commonly misdiagnosed. In our case, the patient was admitted to our hospital for cholangiocarcinoma. Repeated abdominal contrast-enhanced computed tomography scans preoperatively indicated hilar cholangiocarcinoma. Due to insufficient future liver remnant, we planned preoperative percutaneous transhepatic cholangiodrainage and percutaneous transhepatic portal vein embolization based on multidisciplinary team consultation. The patient was then admitted 1 month later for surgery. We performed a laparoscopic cholecystectomy and an extensive laparoscopic right hepatectomy as gallbladder carcinoma was strongly suspected intraoperatively. However, the final diagnosis was traumatic neuroma of the gallbladder confirmed by pathological examination. Traumatic neuroma of the gallbladder is very rare, and we hope to provide some references for diagnosis by reporting our case and reviewing the literature on this topic so that extensive treatment can be avoided, thus improving patients' quality of life. To the best of our knowledge, this is the first reported case of traumatic neuroma without prior surgery in the English literature since 1996.

ZC3H13-mediated N6-methyladenosine modification of PHF10 is impaired by fisetin which inhibits the DNA damage response in pancreatic cancer.

DNA damage repair is a major barrier for chemotherapy efficacy of pancreatic ductal adenocarcinoma (PDAC), including the efficacy of platinum-based and gemcitabine/nab-paclitaxel treatments. N6-methyladenosine modifications (m6A) have recently been reported to play a role in homologous recombination (HR) repair of DNA double strand breaks (DSBs); however, the mechanism of action remains unknown. Our previous work indicated that fisetin may be a promising anti-tumour agent that induces DNA damage. In this study, we reported that fisetin induced DSBs and suppressed HR repair through m6A modification in PDAC cells. The m6A writer ZC3H13 and PHF10, which is a subunit of the PBAF chromatin remodelling complex, were identified as the main molecules affected by fisetin treatment. To our knowledge, it's the first time that PHF10 was found and involved in the DNA damage response. PHF10 loss-of-function resulted in elevated recruitment of γH2AX, RAD51, and 53BP1 to DSB sites and decreased HR repair efficiency. Moreover, ZC3H13 knockdown downregulated the m6A methylation of PHF10 and decreased PHF10 translation in a YTHDF1-dependent manner. In conclusion, our study demonstrates that fisetin enhanced DSBs via ZC3Hl3-mediated m6A modification of PHF10, which may provide insight into novel therapeutic approaches for PDAC.

The role of foreign capital and economic freedom in sustainable food production: Evidence from DLD countries.

In many developing countries, the deficiency in public and private investment has resulted in lower growth rates and stagnation in productivity. The need for a new paradigm of foreign investment and aid in agricultural production is becoming exigent in developing countries. Given the decline in per capita arable land, the rise in production costs, and the increase in population and urbanization, major changes in agriculture have been proposed to boost agricultural production. This present study endeavours to contribute to the existing literature by proving whether foreign capital and economic freedom could catapult food production into the much-anticipated growth. In that regard, we performed GLS with correlated disturbances, system GMM dynamic panel data estimators and D-H causality test. The study found that foreign capital as a whole plays a positive role in food production in developing and least developed countries, but FDI is insignificant in least-developed countries. Moreover, economic freedom plays a positive role in food production in least-developed countries but negative in developing countries. Policymakers and governments should create an enabling environment for sustainable food production.

[Distribution and Influencing Factors of DOM Components in Urban and Suburban Polluted Rivers].

Dissolved organic matter(DOM) in water environments is an important component of the global carbon cycle. Under the current urgency to control the pollution of urban rivers in China, exploring the influence of different exogenous and endogenous secondary pollution and weather patterns on river DOM is the premise to better understand the causes of the pollution. In this study, a large city in China was established as the research area, and the underlying water and sediments from 21 sites along urban and suburban rivers, and other water sources were evaluated. The excitation-emission matrix-parallel factor analysis(EEM-PARAFAC) was used to analyze the difference in DOM composition and equivalent in urban rivers polluted by domestic sewage and suburban rivers polluted by aquaculture, agriculture, and livestock breeding. The results showed that:① DOM components in urban and suburban river waters were mainly protein compounds(tyrosine-and tryptophan-like), containing a small amount of humic acid. Humic acid components of anthropogenic origin were found in urban river water; ② The reasons for the formation of DOM components in urban and suburban rivers were completely different. Urban rivers are mainly polluted by domestic sewage and endogenous secondary pollution, resulting in an increase in anthropogenic humic acid components. Suburban rivers are mainly polluted by agricultural wastewater rich in N and P, which promotes endogenous metabolism of autotrophic bacteria and increases protein components, which may be related to the formation of existing DOM characteristics. ③ Rainfall runoff and urban overflow transported exogenous pollutants into rivers, while hydrodynamic factors such as hydraulic agitation affect the distribution of DOM components in underlying water and sediments through physical effects such as dilution.

Variable sediment methane production in response to different source-associated sewer sediment types and hydrological patterns: Role of the sediment microbiome.

Production of methane (CH4), an essential anthropogenic greenhouse gas, from municipal sewer sediment is a problem deserving intensive attention. Based on long-term laboratory batch tests in conjunction with 16 s rRNA gene sequencing and metagenomics, this study provides the first detailed assessment of the variable sediment CH4 production in response to different pollution source-associated sewer sediment types and hydrological patterns, while addressing the role of the sediment microbiome. The high CH4-production capability of sanitary sewer sediment is shaped by enriched biologically active substrate and dominated by acetoclastic methanogenesis (genus Methanosaeta). Moreover, it involves syntrophic interactions among fermentation bacteria, hydrogen-producing acetogens and methanogens. Distinct source-associated microbial species, denitrifying bacteria and sulfate-reducing bacteria occur in storm sewer and illicit discharge-associated (IDA) storm sewer sediments. This reveals their insufficient microbial function capabilities to support efficient methanogenesis. Hydrogenotrophic methanogenesis (genus Methanobacterium) prevails in both these sediments. In this context, storm sewer sediment has an extremely low CH4-production capability, while IDA storm sewer sediment still shows significant carbon emission through a possibly unique mechanism. Hydrological connections promote the sewer sediment biodegradability and CH4-production capability. In contrast, hydrological disconnection facilitates the prevalence of acetoclastic methanogenesis, sulfate-reducing enzymes, denitrification enzymes and the sulfur-utilizing chemolithoautotrophic denitrifier, which drastically decreases CH4 production. Turbulent suspension of sediments results in relative stagnation of methanogenesis. This work bridges the knowledge gap and will help to stimulate and guide the resolution of 'bottom-up' system-scale carbon budgets and GHG sources, as well as the target CH4 abatement interventions.

BxPC-3-Derived Small Extracellular Vesicles Induce FOXP3+ Treg through ATM-AMPK-Sirtuins-Mediated FOXOs Nuclear Translocations.

Immunotherapy in pancreatic ductal adenocarcinoma (PDAC) treatment faces serious challenges, due particularly to the poor immunogenicity. Cancer cell-derived small extracellular vesicles (sEVs) play important roles in damaging the immune system. However, the effects of pancreatic cancer-derived sEVs on T lymphocytes are unknown. Here we investigated changes in phenotypes and signal transduction pathways in sEVs-treated T lymphocytes. We identified the overexpression of immune checkpoint proteins PD-1, PD-L1, CTLA4, and Tim-3 and the enrichment of FOXP3+ Treg cluster in sEVs-treated T lymphocytes by CyTOF. Gene set enrichment analysis revealed that DNA damage response and metabolic pathways might be involved in sEVs-induced Tregs. ATM, AMPK, SIRT1, SIRT2, and SIRT6 were activated sequentially in sEVs-treated T lymphocytes and essential for sEVs-upregulated expressions of FOXO1A, FOXO3A, and FOXP3. Our study reveals the impact and mechanism of pancreatic cancer cell-derived sEVs on T lymphocytes and may provide insights into developing immunotherapy strategies for PDAC treatment.

Elevated expression of exosomal microRNA-21 as a potential biomarker for the early diagnosis of pancreatic cancer using a tethered cationic lipoplex nanoparticle biochip.

Pancreatic cancer (PC) has a poor prognosis due to the lack of effective molecular biomarkers for early diagnosis. Recent studies have investigated the use of exosomal microRNAs (exmiRs) as diagnostic biomarkers in cancer. The present study examined exmiR-21, exmiR-10b and exmiR-212-3p expression in patients with PC and healthy individuals. The expression levels of exmiR-21, exmiR-10b and exmiR-212-3p were examined in the peripheral blood plasma of 36 patients with PC and 65 healthy controls, using tethered cationic lipoplex nanoparticle biochip. The levels of exmiR-21 in the plasma of 34 mice were also evaluated. The expression levels of exmiR-21 and exmiR-10b were significantly greater in patients with PC compared with the control group. The receiver operating characteristic (ROC) analysis indicated that exmiR-21 had better diagnostic performance (P=0.0003; AUC, 0.7171) compared with the other two exmiRs. The diagnostic value of exmiR-21 improved when combined with exmiR-10b (P<0.0001; AUC, 0.791). Furthermore, exmiR-21 was capable of distinguishing patients with early-stage PC from controls and advanced-stage PC (P<0.05, early stage vs. healthy; P<0.001, early stage vs. advanced stage). The results of the present study revealed that the plasma levels of exmiR-21 and exmiR-10b were upregulated in patients with PC. The ROC analyses indicated that exmiR-21 had the best diagnostic performance among the three exmiRs. Furthermore, exmiR-21 was capable of discriminating patients with early-stage PC from healthy controls. These findings indicate the potential of determining the expression of exmiR-21 from serum using a tethered cationic lipoplex nanoparticle biochip as a novel non-invasive strategy for the early diagnosis of PC.

Fisetin inhibits proliferation of pancreatic adenocarcinoma by inducing DNA damage via RFXAP/KDM4A-dependent histone H3K36 demethylation.

Pancreatic adenocarcinoma (PDAC) is an extremely malignant tumor that is associated with low survival rates. Fisetin is a natural flavonoid that shows diverse antitumor effects, including DNA damage, in various cancers. Increasing studies have demonstrated that epigenetic modifications play critical roles in DNA-damage response. However, the epigenetic regulation mechanism of fisetin in cancers is hardly studied. RFXAP is a critical transcription factor for MHC II molecules, however, its transcriptional role in PDAC is poorly understood. The anti-PDAC effect of fisetin was measured by CCK-8, flow cytometry, xenograft tumor nude mice model. DNA-damage levels were examined by immunofluorescence. Bioinformatics analysis was used to examine the expression of RFXAP and other genes involved in DNA-damage response. ChIP sequencing was used to explore the transcriptional role of RFXAP. The expression of target gene KDM4A was measured by qRT-PCR and western blots. KDM4A promoter activity was analyzed using dual-luciferase reporter assay. RFXAP overexpressing or silencing of PDAC cells was used to explore the effect of RFXAP in DNA damage induced by fisetin. We found that fisetin inhibited cell proliferation and induced DNA damage and S-phase arrest in PDAC. Expression of RFXAP and other DNA-damage response genes were upregulated by fisetin. We revealed that RFXAP expression was relatively low in PDAC and correlated with tumor stage and poor prognosis. Then we explored the transcriptional role of RFXAP and found that RFXAP targeted KDM4A, a special demethylase specific for tri- and dimethylated histone H3K36. We found that overexpression of RFXAP upregulated KDM4A and attenuated methylation of H3K36, thereby impairing DNA repair and enhancing the DNA damage induced by fisetin, while RFXAP silencing showed the opposite effect. We also found the function of fisetin in enhancing the effect of chemotherapy on pancreatic cancer cells. Our findings revealed that fisetin induced DNA damage via RFXAP/KDM4A-dependent histone H3K36 demethylation, thus causing inhibition of proliferation in PDAC.