Environmental eustress promotes liver regeneration through the sympathetic regulation of type 1 innate lymphoid cells to increase IL-22 in mice.

BACKGROUND AND AIMS: The liver has the unique ability of regeneration, which is extremely important for restoring homeostasis after liver injury. Although clinical observations have revealed an association between psychological stress and the liver, whether stress has a causal influence on the liver regeneration remains markedly less defined. APPROACH AND RESULTS: Rearing rodents in an enriched environment (EE) can induce eustress or positive psychological stress. Herein, EE-induced eustress was found to significantly enhance the ability of liver regeneration after partial hepatectomy or carbon tetrachloride-induced liver injury based on the more rapid restoration of liver/body weight ratio and the significantly increased number of proliferating hepatocytes in EE mice. Mechanistically, the cytokine array revealed that IL-22 was markedly increased in the regenerating liver in response to EE. Blockade of IL-22 signaling abrogated the enhanced liver regeneration induced by EE. Group 1 innate lymphoid cells (ILCs), including type 1 ILCs (ILC1s), have been identified as the major sources of IL-22 in the regenerating liver. EE housing led to a rapid accumulation of hepatic ILC1s after partial hepatectomy and the EE-induced enhancement of liver regeneration and elevation of IL-22 was nearly eliminated in ILC1-deficient Tbx21-/- mice. Chemical sympathectomy or blockade of ß-adrenergic signaling also abolished the effect of EE on ILC1s and attenuated the enhanced liver regeneration of EE-housed mice. CONCLUSION: The study findings support the brain-liver axis and suggest that environment-induced eustress promotes liver regeneration through the sympathetic nerve/ILC1/IL-22 axis.

Amplification-Free Ratiometric Electrochemical Aptasensor for Point-of-Care Detection of Therapeutic Monoclonal Antibodies.

The rapid quantification of therapeutic monoclonal antibodies (mAbs) is of great significance to their pharmacokinetics/pharmacodynamics (PK/PD) research and the personalized medication for disease treatment. Taking advantage of the direct decoration of tens of redox tags to the target of interest, we illustrate herein an amplification-free ratiometric electrochemical aptasensor for the point-of-care (POC) detection of trace amounts of therapeutic mAbs. The POC detection of therapeutic mAbs involved the use of the methylene blue (MB)-conjugated aptamer as the affinity element and the decoration of therapeutic mAbs with ferrocene (Fc) tags via the boronate crosslinking, in which the MB-derived peak current was used as the reference signal, and the peak current of the Fc tag was used as the output signal. As each therapeutic mAb carries tens of diol sites for the site-specific decoration of the Fc output tags, the boronate crosslinking enabled the amplification-free detection, which is cost-effective and quite simple in operation. In the presence of bevacizumab (BevMab) as the target, the resulting ratiometric signal (i.e., the IFc/IMB value) exhibited a good linear response over the range of 0.025-2.5 µg/mL, and the limit of detection (LOD) of the electrochemical aptasensor was 6.5 ng/mL. Results indicated that the aptamer-based affinity recognition endowed the detection of therapeutic mAbs with high selectivity, while the ratiometric readout exhibited satisfactory reproducibility and robustness. Moreover, the ratiometric electrochemical aptasensor is applicable to the detection of therapeutic mAbs in serum samples. Taking together, the amplification-free ratiometric electrochemical aptasensor holds great promise in the POC detection of therapeutic mAbs.

Dually Amplified Electrochemical Aptasensor for Endotoxin Detection via Target-Assisted Electrochemically Mediated ATRP.

As the entering of bacterial endotoxin into blood can cause various life-threatening pathological conditions, the screening and detection of low-abundance endotoxin are of great importance to human health. Taking advantage of signal amplification by target-assisted electrochemically mediated atom transfer radical polymerization (teATRP), we illustrate herein a simple and cost-effective electrochemical aptasensor capable of detecting endotoxin with high sensitivity and selectivity. Specifically, the aptamer receptor was employed for the selective capture of endotoxin, of which the glycan chain was then decorated with ATRP initiators via covalent coupling between the diol sites and phenylboronic acid (PBA) group, followed by the recruitment of ferrocene signal reporters via the grafting of polymer chains through potentiostatic eATRP under ambient temperature. As the glycan chain of endotoxin can be decorated with hundreds of ATRP initiators while the further grafting of polymer chains through eATRP can recruit hundreds to thousands of signal reporters to each initiator-decorated site, the teATRP-based strategy allows for the dual amplification of the detection signal. This dually amplified electrochemical aptasensor has the ability to sensitively and selectively detect endotoxin at a concentration as low as 1.2 fg/mL, and its practical applicability has been further demonstrated using human serum samples. Owing to the simplicity, high efficiency, biocompatibility, and inexpensiveness of the teATRP-based amplification strategy, this electrochemical aptasensor holds great application potential in the sensitive and selective detection of low-abundance endotoxin and many other glycan chain-containing bio-targets.

Electrochemically Controlled Atom Transfer Radical Polymerization for Electrochemical Aptasensing of Tumor Biomarkers.

Tumor biomarkers are of great value in the liquid biopsy of malignant tumors. In this work, a simple and cost-friendly electrochemical aptasensor was presented for the highly sensitive and selective detection of glycoprotein tumor biomarkers. The DNA aptamer-modified electrode was used as the sensing interface to specifically capture the target glycoprotein tumor biomarkers, to which the alkyl halide initiators for atom transfer radical polymerization (ATRP) were then attached via the esterification crosslinking between the boronic acid group and the cis-dihydroxyl sites of the conjugated oligosaccharide chains on glycoprotein tumor biomarkers followed by the growth of long-chain polymers through electrochemically controlled ATRP (eATRP) to efficiently recruit the ferrocene detection tags. As there are tens to hundreds of cis-dihydroxyl sites on a glycoprotein tumor biomarker for attaching ATRP initiators while each long-chain polymer can recruit hundreds to thousands of ferrocene detection tags, a significantly high current signal can be generated even in the presence of ultralow-abundance targets. Hence, the eATRP-based electrochemical aptasensor is capable of sensitively and selectively detecting glycoprotein tumor biomarkers. Using alpha-fetoprotein as the model target, the limit of detection was demonstrated to be 0.32 pg/mL. Moreover, the aptasensor has been successfully applied to detect glycoprotein tumor biomarkers in human serum samples. In view of its high sensitivity and selectivity, simple operation, and cost-friendliness, the eATRP-based electrochemical aptasensor shows great promise in the glycoprotein-based liquid biopsy of malignant tumors, even at the early stage of development.

Boronate-Affinity Cross-Linking-Based Ratiometric Electrochemical Detection of Glycoconjugates.

Despite the widespread application of the boronate-affinity cross-linking (BAC) in the separation, enrichment, and sensing of glycoconjugates, it remains a huge challenge to integrate the BAC into the selective electrochemical detection of glycoconjugates due to the poor selectivity of the BAC. Herein, we demonstrate a BAC-based ratiometric electrochemical method for the simple, low-cost, and highly sensitive and selective detection of glycoconjugates. Briefly, the methylene blue (MB)-tagged nucleic acid aptamer is exploited as the recognition element to selectively capture target glycoconjugate, to which a large number of ferrocene (Fc) tags are subsequently labeled via the BAC between the phenylboronic acid (PBA) group and the cis-diol site of the oligosaccharide chains on the captured targets. Using the MB tag as the internal reference and the Fc tag as the reporter of the target capture, the dual-signal output enables the ratiometric detection. Due to the presence of a high density of the cis-diol sites on a glycoconjugate, sufficiently high sensitivity can be obtained even without using any amplification strategies. Using glycoprotein mucin 1 (MUC1) as the model target, the signal ratio (IFc/IMB) exhibits good linearity over the range from 0.05 to 50 U/mL, with a detection limit of 0.021 U/mL. In addition to the high sensitivity and selectivity, the results of the analysis of MUC1 in serum samples are acceptable. By virtue of its simplicity, cost-effectiveness, and high robustness and reproducibility, this BAC-based ratiometric electrochemical method holds great promise in the highly sensitive and selective detection of glycoconjugates.

Biologically Mediated RAFT Polymerization for Electrochemical Sensing of Kinase Activity.

The assay of kinase activity with ultrahigh sensitivity is important to medical diagnostics and drug discovery. Herein, we report the biologically mediated RAFT polymerization (BMRP) and its potential use as an efficient amplification strategy in the ultrasensitive electrochemical sensing of kinase activity. In BMRP, the reversible addition-fragmentation chain-transfer (RAFT) process is initiated and sustained by the reduced form of coenzyme I (i.e., NADH), which can efficiently mediate the direct fragmentation of thiocarbonylthio (TCT) compounds (or the TCT-capped dormant chains) to produce an initiating/propagating radical under mild conditions. Due to the absence of exogenous radicals, the notorious radical termination in RAFT equilibrium can be greatly suppressed. For the sensing of kinase activity, the recognition peptides, without carboxyl groups, are immobilized via the Au-S self-assembly. After phosphorylation, TCT compounds (as RAFT agents) are tethered to the enzymatically generated phosphate groups via the carboxylate-Zr(IV)-phosphate (CZP) linkage. Subsequently, the BMRP of ferrocenylmethyl methacrylate (FcMMA) results in the labeling of each phosphate group with hundreds to thousands of Fc tags, thereby greatly amplifying the sensing signal. Obviously, the BMRP-based strategy is biologically friendly, highly efficient, uncomplicated, and quite low-cost. The detection limit of 1.85 mU/mL has been achieved toward the selective sensing of the cAMP-dependent protein kinase (PKA). Moreover, the proposed kinase sensor is applicable to inhibitor screening and kinase activity sensing in serum samples. By virtue of its low cost, high sensitivity and selectivity, and uncomplicated operation, the proposed kinase sensor holds great potential in medical diagnostics and drug discovery.

Boronate Affinity-Amplified Electrochemical Aptasensing of Lipopolysaccharide.

As lipopolysaccharide (LPS) is closely associated with sepsis and other life-threatening conditions, the point-of-care (POC) detection of LPS is of significant importance to human health. In this work, we illustrate an electrochemical aptasensor for the POC detection of low-abundance LPS by utilizing boronate affinity (BA) as a simple, efficient, and cost-effective amplification strategy. Briefly, the BA-amplified electrochemical aptasensing of LPS involves the tethering of the aptamer receptors and the BA-mediated direct decoration of LPS with redox signal tags. As the polysaccharide chain of LPS contains hundreds of cis-diol sites, the covalent crosslinking between the phenylboronic acid group and cis-diol sites can be harnessed for the site-specific decoration of each LPS with hundreds of redox signal tags, thereby enabling amplified detection. As it involves only a single-step operation (∼15 min), the BA-mediated signal amplification holds the significant advantages of unrivaled simplicity, rapidness, and cost-effectiveness over the conventional nanomaterial- and enzyme-based strategies. The BA-amplified electrochemical aptasensor has been successfully applied to specifically detect LPS within 45 min, with a detection limit of 0.34 pg/mL. Moreover, the clinical utility has been validated based on LPS detection in complex serum samples. As a proof of concept, a portable device has been developed to showcase the potential applicability of the BA-amplified electrochemical LPS aptasensor in the POC testing. In view of its simplicity, rapidness, and cost-effectiveness, the BA-amplified electrochemical LPS aptasensor holds broad application prospects in the POC testing.

Electrochemical Detection of Femtomolar DNA via Boronate Affinity-Mediated Decoration of Polysaccharides with Electroactive Tags.

In view of their high efficiency and cost-effectiveness, polymers are of great promise as carriers for signal tags in amplified detection. Herein, we present a polysaccharide-amplified method for the electrochemical detection of a BRCA1 breast cancer gene-derived DNA target at the femtomolar levels. Briefly, peptide nucleic acid (PNA) with a complementary sequence was tethered as the capture probe for the DNA target, to which carboxyl group-containing polysaccharides were then attached via facile phosphate-Zr(IV)-carboxylate crosslinking, followed by the decoration of polysaccharide chains with electroactive ferrocene (Fc) signal tags via affinity coupling between a cis-diol site and phenylboronic acid (PBA) group. As the polysaccharide chain contains hundreds of cis-diol sites, boronate affinity can enable the site-specific decoration of each polysaccharide chain with hundreds of Fc signal tags, efficiently transducing each target capture event into the decoration of many Fc signal tags. As polysaccharides are cheap, renewable, ubiquitous, and biodegradable natural biopolymers, the use of polysaccharides for signal amplification offers the benefits of high efficiency, cost-effectiveness, excellent biocompatibility, and environmental friendliness. The linear range of the polysaccharide-amplified method for DNA detection was demonstrated to be from 10 fM to 10 nM (R2 = 0.996), with the detection limit as low as 2.9 fM. The results show that this method can also discriminate single base mismatch with satisfactory selectivity and can be applied to DNA detection in serum samples. In view of these merits, the polysaccharide-amplified PNA-based electrochemical method holds great promise in DNA detection with satisfactory sensitivity and selectivity.

Boronate Affinity-Based Electrochemical Aptasensor for Point-of-Care Glycoprotein Detection.

As a class of oligosaccharide chain-containing proteins, glycoproteins are of great value in screening and early diagnosis of malignant tumors and other major diseases. Herein, we report a universal boronate affinity-based electrochemical aptasensor for point-of-care glycoprotein detection. Aptasensing of glycoproteins involves the specific recognition and capture of target glycoproteins by end-tethered nucleic acid aptamers and the site-specific labeling of ferrocene tags via the phenylboronic acid (PBA)-based boronate affinity interactions because the cis-diol sites of oligosaccharide chains on glycoproteins can selectively react with the PBA receptor groups to form cyclic phenylborates in aqueous basic media. Due to the presence of hundreds to thousands of cis-diol sites on a glycoprotein, a large number of ferrocene tags can be recruited for the signal-on aptasensing of glycoproteins at a low-abundance level, eliminating the need for extra amplification strategies. As a result, the boronate affinity-based electrochemical aptasensor is highly sensitive and selective for glycoprotein detection and tolerant to the false-positive results. The detection limit for α-fetoprotein (AFP) is 0.037 ng/mL, with a linear response ranging from 0.1 to 100 ng/mL. In addition to the merits of simple operation, short assay time, and low detection cost, the aptasensor is applicable to the detection of glycoproteins in serum samples and the point-of-care detection using disposable flexible electrodes. Overall, this work provides a universal and promising platform for the point-of-care detection of glycoproteins, holding great potential in screening and early diagnosis of glycoprotein-related malignant tumors and other major diseases.

Caveolin-2 is regulated by BRD4 and contributes to cell growth in pancreatic cancer.

BACKGROUND: The bromodomain and extra-terminal domain (BET) family of proteins, especially BRD4 play an important role in epigenetic regulation, and are essential for cell survival and also are promising anticancer targets. This study aims to analyze the effect of BRD4 on the cell growth and progression of pancreatic cancer and novel mechanisms involved. METHODS: Expression of BRD4 in pancreatic cancer and paired adjacent noncancerous tissues from 76 patients was analyzed by western blotting, immunohistochemistry, and real time PCR. Its correlation with the clinicopathological characteristics and prognosis of pancreatic cancer patients was analyzed. The effects of BRD4 on the cell proliferation were detected by colony formation assay and sulforhodamine B assay. Migration and invasion were determined by Transwell assays, and the effect of BRD4 on subcutaneous tumor formation was verified in nude mice. Cell cycle analysis was detected by flow cytometry. The potential downstream targets of BRD4 and related molecular mechanisms were clarified by RNA sequencing, chromatin immunoprecipitation and dual luciferase reporter assay. RESULTS: BRD4 was overexpressed in pancreatic cancer. Biological results showed that BRD4 functioned as tumor promoter, facilitated cell proliferation, migration and invasion in vitro and in vivo. Further, caveolin-2 was selected as the downstream gene of BRD4 by RNA sequencing. Caveolin-2 overexpression can partially reverse the decreased cell growth ability caused by BRD4 knockdown, but did not affect cell migration and invasion. Chromatin immunoprecipitation assay and dual luciferase reporter assay revealed BRD4 could bind to the promoter region of caveolin-2 and upregulate caveolin-2 expression. Clinical data further indicated a positive correlation between BRD4 and caveolin-2 expression. BRD4 (high)/caveolin-2 (high) correlated with shorter overall survival of patients with pancreatic cancer. Multivariate analysis revealed that both BRD4 and caveolin-2 were independent factors. CONCLUSIONS: Our findings reveal the oncogenic effects of BRD4 in pancreatic cancer and elucidate a possible mechanism by which BRD4 and caveolin-2 act to enhance cell growth. Targeting the BRD4-caveolin-2 interaction by development of BET inhibitors will be a therapeutic strategy for pancreatic cancer.

The interplay of circulating tumor DNA and chromatin modification, therapeutic resistance, and metastasis.

Peripheral circulating free DNA (cfDNA) is DNA that is detected in plasma or serum fluid with a cell-free status. For cancer patients, cfDNA not only originates from apoptotic cells but also from necrotic tumor cells and disseminated tumor cells that have escaped into the blood during epithelial-mesenchymal transition. Additionally, cfDNA derived from tumors, also known as circulating tumor DNA (ctDNA), carries tumor-associated genetic and epigenetic changes in cancer patients, which makes ctDNA a potential biomarker for the early diagnosis of tumors, monitory and therapeutic evaluations, and prognostic assessments, among others, for various kinds of cancer. Moreover, analyses of cfDNA chromatin modifications can reflect the heterogeneity of tumors and have potential for predicting tumor drug resistance.

The size distribution of the agitated saline microbubbles for contrast transcranial Doppler generated using standard manual methods.

Agitated saline microbubbles (MBs) are a common contrast agent for determining right-to-left shunt (RLS) by the contrast transcranial Doppler (c-TCD). The size of the generated bubbles is not standardized in clinical practice. MBs were generated using the recommended manual method by reciprocating motion through two syringes. The bubble size distributions (BSD) were measured using the microscopic shadow imaging technique. The results show that the diameter of MBs is mainly distributed between 10 and 100 µm, the mean bubble size is between 21 and 34 µm, the Sauter mean diameter (D32) is primarily between 50 and 300 µm, and the standard deviation (SD) is between 6 and 17 µm in 80 experiments. It provides a more accurate basis for the recommended manual method instability. The high variance values of the BSD indicate that the manual method has low stability and repeatability. The results of this study can be useful for further improvement of the reliability of c-TCD in detecting RLS. RESEARCH HIGHLIGHTS: This study provided the first detailed descriptions of the MBs size distribution in a flowing contrast agent by the microscopic shadow imaging technique. It reveals significant differences in the bubble size of manual foaming during repeated manipulations for each individual and between individuals.

Boronate crosslinking-based ratiometric electrochemical assay of glycated albumin.

As a product of nonenzymatic glycation, glycated albumin (GA) is a promising serum marker for the short-term glycemic monitoring in patients with diabetes. On the basis of the boronate crosslinking (BCL)-enabled direct labeling of ferrocene (Fc) tags to the nonenzymatically glycated (NEG) sites, we report herein a novel aptamer-based ratiometric electrochemical (apt-REC) platform for the point-of-care (POC) assay of GA. This apt-REC platform is based on the recognition of GA proteins by the methylene blue (MB)-modified aptamer receptors and the labeling of the Fc tags to the NEG sites via the BCL. Using MB as the reference tag and Fc as the quantification tag, the ratio of the oxidation currents (i.e., IFc/IMB) can serve as the yardstick for the ratiometric assay of GA. Due to the presence of tens of the NEG sites, each GA protein can be labeled with tens of quantification tags, permitting the amplified assay in a simple, time-saving, and low-cost manner. The ratiometric signal exhibited a good linear response over the range from 0.1 to 100 µg/mL, with a detection limit of 45.5 ng/mL. In addition to the superior reproducibility and robustness, this apt-REC platform is highly selective (capable of discriminating GA against human serum albumin (HSA)) and applicable to GA assay in serum samples. Due to its low cost, high reproducibility and robustness, simple operation, and high sensitivity and selectivity, this apt-REC platform holds great promise in the POC assay of GA for diabetes management.

Histone Methyltransferase KMT2B Promotes Metastasis and Angiogenesis of Cervical Cancer by Upregulating EGF Expression.

Evidence has indicated that lysine methyltransferase 2B (KMT2B), a major H3K4 tri-methyltransferase (H3K4me3), contributes to the development of various cancers; however, its role in cervical cancer (CC) is unclear. In this study, increased KMT2B expression was observed in human CC specimens and significantly associated with poor prognosis. The condition medium of KMT2B-overexpressing cells facilitated angiogenesis in vitro. In the subcutaneous model of human CC, KMT2B overexpression significantly promoted tumor growth and increased tumor vascular density. Meanwhile, KMT2B enhanced the migration and invasion of CC cells and promoted their metastasis to bone in a tail-vein-metastasis model. Mechanistically, the genes upregulated by KMT2B were significantly enriched in PI3K-AKT pathway. Using H3K4me3 ChIP-seq analysis, we found increased H3K4me3 level at EGF promoter region in KMT2B-overexpressing HeLa cells. ChIP-qPCR experiments not only confirmed the increased H3K4me3 level of EGF promoter but also determined that in KMT2B-overexpressing HeLa cells, KMT2B increased binding with the EGF promoter. Blocking EGFR diminished the KMT2B-induced PI3K-AKT signaling activation and CC cell migration and invasion. Moreover, EGFR inhibitors abolished the KMT2B-drived tube formation capacity of HUVECs. In conclusion, KMT2B facilitates CC metastasis and angiogenesis by upregulating EGF expression, and may serve as a new therapeutic target for CC.

P2RY6 Has a Critical Role in Mouse Skin Carcinogenesis by Regulating the YAP and ß-Catenin Signaling Pathways.

P2RY6 is highly expressed in skin keratinocytes, but its function in skin diseases is unclear. We use a two-step chemical induction method to induce mouse skin tumor formation. Multiple in vitro and in vivo assays were used to explore the role of P2RY6 in skin tumors. We report that P2ry6-deficient mice exhibit marked resistance to 7,12-dimethylbenz[a]anthracene/12-O-tetradecanoylphorbol-13-acetate (TPA)-induced skin papilloma formation compared with wild-type mice. Consistent with these findings, epidermal hyperplasia in response to TPA was suppressed in the P2ry6-knockout or MRS2578 (P2RY6 antagonist)-treated mice. The dramatic decrease in hyperplasia and tumorigenesis due to P2ry6 disruption was associated with the suppression of TPA-induced keratinocyte proliferation and inflammatory reactions. Notably, P2ry6 deletion prevented the TPA-induced increase in YAP nuclear accumulation and its downstream gene expression in an MST/LATS1-dependent manner. On TPA stimulation, enhanced activation of MAPK/extracellular signal‒regulated kinase kinase 1 and ß-catenin were also impaired in P2ry6-knockout primary keratinocytes, tumor tissues, or MRS2578-treated HaCaT cells. Moreover, mutual promotion of the YAP and ß-catenin signaling pathways was observed in normal skin cells treated with TPA, whereas P2ry6 deletion could inhibit their crosstalk by regulating MAPK/extracellular signal‒regulated kinase kinase 1. Thus, P2RY6 is a critical positive regulator of skin tumorigenesis through the modulation of the Hippo/YAP and Wnt/ß-catenin signaling pathways.

Increased Expression of Mitochondrial UQCRC1 in Pancreatic Cancer Impairs Antitumor Immunity of Natural Killer Cells via Elevating Extracellular ATP.

Pancreatic cancer (PC) is one of the most lethal malignancies characterized by a highly immunosuppressive tumor microenvironment (TME). Previously, we have reported that ubiquinol-cytochrome c reductase core protein I (UQCRC1), a key component of mitochondrial complex III, is generally upregulated in PC and produces extracellular ATP (eATP) to promote PC progression. Here, we sought to investigate whether the oncogenic property of UQCRC1 is generated through its effects on natural killer (NK) cells in the TME. We found that UQCRC1 overexpression in PC cells inhibited cytotoxicity of NK cells, as well as the infiltration of NK cells toward PC, whereas knockdown of UQCRC1 enhanced the cytotoxicity and chemotaxis of NK cells. Adoptive NK cell therapy in the subcutaneous mouse model and CIBERSORTx analysis with human PC specimens confirmed UQCRC1 elicited immunosuppressive effects on NK cells. Such UQCRC1-induced impairment of NK cells was mediated by eATP and its metabolite adenosine via P2Y11R and A2AR, respectively. Mechanistically, we found the UQCRC1/eATP axis reduced the expression of chemokine CCL5 in cancer cells and altered the balance of activating receptor DNAM-1 and inhibitory receptor CD96 on NK-92MI cells, resulting in decreased chemotaxis and exhausted phenotype of NK-92MI cells. Taken together, our study provides the evidence to support a novel mechanism by which energy metabolism change in cancer cells remodels the TME and impedes NK cell surveillance. It also suggests that targeting UQCRC1 may be a potential combined strategy for PC immunotherapy.

Shedding Light on the Role of Neurotransmitters in the Microenvironment of Pancreatic Cancer.

Pancreatic cancer (PC) is a highly lethal malignancy with a 5-year survival rate of less than 8%. The fate of PC is determined not only by the malignant behavior of the cancer cells, but also by the surrounding tumor microenvironment (TME), consisting of various cellular (cancer cells, immune cells, stromal cells, endothelial cells, and neurons) and non-cellular (cytokines, neurotransmitters, and extracellular matrix) components. The pancreatic TME has the unique characteristic of exhibiting increased neural density and altered microenvironmental concentration of neurotransmitters. The neurotransmitters, produced by both neuron and non-neuronal cells, can directly regulate the biological behavior of PC cells via binding to their corresponding receptors on tumor cells and activating the intracellular downstream signals. On the other hand, the neurotransmitters can also communicate with other cellular components such as the immune cells in the TME to promote cancer growth. In this review, we will summarize the pleiotropic effects of neurotransmitters on the initiation and progression of PC, and particularly discuss the emerging mechanisms of how neurotransmitters influence the innate and adaptive immune responses in the TME in an autocrine or paracrine manner. A better understanding of the interplay between neurotransmitters and the immune cells in the TME might facilitate the development of new effective therapies for PC.

CHPF promotes gastric cancer tumorigenesis through the activation of E2F1.

Chondroitin polymerizing factor (CHPF) is an important glycosyltransferase involved in the biosynthesis of chondroitin sulfate. However, the relationship between CHPF and gastric cancer has not been fully investigated. CHPF expression in gastric cancer tissues was detected by immunohistochemistry and correlated with gastric cancer patient prognosis. Cultured gastric cancer cells and human gastric epithelial cell line GES1 were used to investigate the effects of shCHPF and shE2F1 on the development and progression of gastric cancer by MTT, western blotting, flow cytometry analysis of cell apoptosis, colony formation, transwell and gastric cancer xenograft mouse models, in vitro and in vivo. In gastric cancer tissues, CHPF was found to be significantly upregulated, and its expression correlated with tumor infiltration and advanced tumor stage and shorter patient survival in gastric cancer. CHPF may promote gastric cancer development by regulating cell proliferation, colony formation, cell apoptosis and cell migration, while knockdown induced the opposite effects. Moreover, the results from in vivo experiments demonstrated that tumor growth was suppressed by CHPF knockdown. Additionally, E2F1 was identified as a potential downstream target of CHPF in the regulation of gastric cancer, and its knockdown decreased the CHPF-induced promotion of gastric cancer. Mechanistic study revealed that CHPF may regulate E2F1 through affecting UBE2T-mediated E2F1 ubiquitination. This study showed, for the first time, that CHPF is a potential prognostic indicator and tumor promoter in gastric cancer whose function is likely carried out through the regulation of E2F1.

A narrative review of Safety management of 1 L platinum-based chemotherapy and maintenance olaparib in BRCA mutated advanced pancreatic cancer.

OBJECTIVE: We aimed to review the safety management and efficacy of a modified FOLFIRINOX regimen to help clinicians improve first-line platinum-based chemotherapy and maintenance olaparib to treat patients with advanced PC with BRCA mutations. BACKGROUND: FOLFIRINOX has relatively high efficacy among all the chemotherapy regimens for advanced pancreatic carcinoma (PC) patients. However, the combination of drugs is often associated with a high incidence of adverse reactions, and safety concerns are the primary reasons limiting its clinical use. In recent years, through the adjustment of drug dosage and administration route, the toxicity of FOLFIRINOX has been reduced while its clinical effect has been maintained. Also, the empirical use of prophylactics in the chemotherapy cycle can reduce chemotherapy-related serious adverse reactions. All these methods have established a good foundation for the maintenance of olaparib. METHODS: Pubmed, Embase, and the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) were searched using the terms' pancreatic cancer', 'folfirinox', 'parp inhibitor', 'chemotherapy', and 'adverse reaction' from 2005 through to March 2021. CONCLUSIONS: The historical evidence suggested that modified FOLFIRINOX and maintenance olaparib could significantly improve the therapeutic effect and reduce the toxicity. It also provides some insights for clinicians to choose the most suitable regimen for each patient.

E3 Ubiquitin Ligase UBR5 Promotes the Metastasis of Pancreatic Cancer via Destabilizing F-Actin Capping Protein CAPZA1.

The ubiquitin-proteasome system (UPS) is a regulated mechanism of intracellular protein degradation and turnover, and its dysfunction is associated with various diseases including cancer. UBR5, an E3 ubiquitin ligase, is emerging as an important regulator of the UPS in cancers, but its role in pancreatic cancer is poorly understood. Here, we show that UBR5 is significantly upregulated in pancreatic cancer tissues. High UBR5 expression is correlated with increased lymph node metastasis and poor survival of patients. The loss-of-function and gain-of-function studies demonstrated that UBR5 substantially enhanced the in vitro migratory and invasive ability of pancreatic cancer cells. UBR5 knockdown also markedly inhibited in vivo cancer metastasis in the liver metastatic model of pancreatic cancer in nude mice, suggesting UBR5 as a potent metastatic promoter in pancreatic cancer. Furthermore, using co-immunoprecipitation combined with mass spectrometry analyses, CAPZA1, a member of F-actin capping protein α subunit family, was identified as a novel substrate of UBR5. UBR5 overexpression could promote the degradation of CAPZA1 via the UPS and induce the accumulation of F-actin, which has been described as an essential molecular event during the process of CAPZA1 deficiency-induced cancer cells migration and invasion. UBR5 knockdown significantly increased the intracellular level of CAPZA1 and CAPZA1 downregulation largely reversed the UBR5 knockdown-induced suppression of cell migration and invasion in pancreatic cancer cells. Collectively, our findings unveil UBR5 as a novel and critical regulator of pancreatic cancer metastasis and highlight the potential for UBR5-CAPZA1 axis as a therapeutic target for preventing metastasis in pancreatic cancer patients, especially in those with increased UBR5 expression.