An ULK1/2-PXN mechanotransduction pathway suppresses breast cancer cell migration.

The remodeling and stiffening of the extracellular matrix (ECM) is a well-recognized modulator of breast cancer progression. How changes in the mechanical properties of the ECM are converted into biochemical signals that direct tumor cell migration and metastasis remain poorly characterized. Here, we describe a new role for the autophagy-inducing serine/threonine kinases ULK1 and ULK2 in mechanotransduction. We show that ULK1/2 activity inhibits the assembly of actin stress fibers and focal adhesions (FAs) and as a consequence impedes cell contraction and migration, independent of its role in autophagy. Mechanistically, we identify PXN/paxillin, a key component of the mechanotransducing machinery, as a direct binding partner and substrate of ULK1/2. ULK-mediated phosphorylation of PXN at S32 and S119 weakens homotypic interactions and liquid-liquid phase separation of PXN, impairing FA assembly, which in turn alters the mechanical properties of breast cancer cells and their response to mechanical stimuli. ULK1/2 and the well-characterized PXN regulator, FAK/Src, have opposing functions on mechanotransduction and compete for phosphorylation of adjacent serine and tyrosine residues. Taken together, our study reveals ULK1/2 as important regulator of PXN-dependent mechanotransduction.

Brassisterol A, a new ergosterol from co-cultivation of fungi attenuates neuroinflammation via targeting NLRP3/caspase-1/GSDMD pathway.

Three new ergosterol derivatives brassisterol A-C (1-3) and two new epimeric bicycle-lactones brassictones A and B (4 and 5), were isolated from the co-cultivation of Alternaria brassicicola and Penicillium granulatum. The absolute configurations of these isolates were confirmed by extensive NMR spectra, TD-DFT ECD calculation, and the single crystal XRD data analysis. Amongst the metabolites, compound 1 exhibited potential anti-Parkinson's disease activity in both MPTP-induced zebrafish and MPP+-induced SH-SY5Y cells. Molecular mechanism studies in vitro showed that 1 attenuated the increase of α-synuclein, NLRP3, ASC, caspase-1, IL-1ß, IL-18, and GSDMD expression in the MPP+ induced PD model. Molecular docking in silico simulations exhibited that 1 was well accommodated to one of the binding pockets of NLRP3 8ETR in an appropriate conformation via forming typical hydrogen bonds as well as possessing a high negative binding affinity (-8.97 kcal/mol). Thus, our work suggested that 1 protected dopaminergic cell from neuroinflammation via targeting NLRP3/caspase-1/GSDMD signaling pathway.

Trends and projections of inflammatory bowel disease at the global, regional and national levels, 1990-2050: a bayesian age-period-cohort modeling study.

BACKGROUND: Inflammatory bowel disease (IBD) is a global health concern with varying levels and trends across countries and regions. Understanding these differences is crucial for effective prevention and treatment strategies. METHODS: Using data from the 2019 Global Burden of Disease study, we examine IBD incidence, mortality, and disability-adjusted life years (DALYs) rates in 198 countries from 1990 to 2019. To assess changes in the burden of IBD, estimated annual percentage changes (EAPC) were calculated, and a Bayesian age-period-cohort model was used to predict the future 30-year trends of IBD. RESULTS: In 2019, there were 405,000 new IBD cases globally (95% uncertainty interval (UI) 361,000 to 457,000), with 41,000 deaths (95% UI 35,000 to 45,000) and 1.62million DALYs (95% UI 1.36-1.92million). The global age-standardized incidence rate in 2019 was 4.97 per 100,000 person-years (95% UI 4.43 to 5.59), with a mortality rate of 0.54 (95% UI 0.46 to 0.59) and DALYs rate of 20.15 (95% UI 16.86 to 23.71). From 1990 to 2019, EAPC values for incidence, mortality, and DALYs rates were - 0.60 (95% UI - 0.73 to - 0.48), - 0.69 (95% UI - 0.81 to - 0.57), and - 1.04 (95% UI - 1.06 to - 1.01), respectively. Overall, the burden of IBD has shown a slow decline in recent years. In SDI stratification, regions with higher initial SDI (high-income North America and Central Europe) witnessed decreasing incidence and mortality rates with increasing SDI, while regions with lower initial SDI (South Asia, Oceania, and Latin America) experienced a rapid rise in incidence but a decrease in mortality with increasing SDI. Predictions using a Bayesian model showed lower new cases and deaths from 2020 to 2050 than reference values, while the slope of the predicted incidence-time curve closely paralleled that of the 2019 data. CONCLUSION: Increasing cases, deaths, and DALYs highlight the sustained burden of IBD on public health. Developed countries have stabilized or declining incidence rates but face high prevalence and societal burden. Emerging and developing countries experience rising incidence. Understanding these changes aids policymakers in effectively addressing IBD challenges in different regions and economic contexts.

An Integrated Multi-Omics Analysis Identifying Immune Subtypes of Pancreatic Cancer.

Limited studies have explored novel pancreatic cancer (PC) subtypes or prognostic biomarkers based on the altered activity of relevant signaling pathway gene sets. Here, we employed non-negative matrix factorization (NMF) to identify three immune subtypes of PC based on C7 immunologic signature gene set activity in PC and normal samples. Cluster 1, the immune-inflamed subtype, showed a higher response rate to immune checkpoint blockade (ICB) and had the lowest tumor immune dysfunction and exclusion (TIDE) scores. Cluster 2, the immune-excluded subtype, exhibited strong associations with stromal activation, characterized by elevated expression levels of transforming growth factor (TGF)-ß, cell adhesion, extracellular matrix remodeling, and epithelial-to-mesenchymal transition (EMT) related genes. Cluster 3, the immune-desert subtype, displayed limited immune activity. For prognostic prediction, we developed an immune-related prognostic risk model (IRPM) based on four immune-related prognostic genes in pancreatic cancer, RHOF, CEP250, TSC1, and KIF20B. The IRPM demonstrated excellent prognostic efficacy and successful validation in an external cohort. Notably, the key gene in the prognostic model, RHOF, exerted significant influence on the proliferation, migration, and invasion of pancreatic cancer cells through in vitro experiments. Furthermore, we conducted a comprehensive analysis of somatic mutational landscapes and immune landscapes in PC patients with different IRPM risk scores. Our findings accurately stratified patients based on their immune microenvironment and predicted immunotherapy responses, offering valuable insights for clinicians in developing more targeted clinical strategies.

The Prognostic Value and the Oncogenic and Immunological Roles of Vacuolar Protein Sorting Associated Protein 26 A in Pancreatic Adenocarcinoma.

The identification of the prognostic markers and therapeutic targets might benefit the diagnosis and treatment of pancreatic adenocarcinoma (PAAD), one of the most aggressive malignancies. Vacuolar protein sorting associated protein 26 A (VPS26A) is a candidate prognosis gene for hepatocellular carcinoma, but its expression and function in PAAD remain unknown. The mRNA and protein expression of VPS26A in PAAD was explored and validated by bioinformatics and immunohistochemical analysis. The correlation between VPS26A expression and various clinical parameters, genetic status, diagnostic and prognostic value, survival and immune infiltration were evaluated, and the co-expressed gene-set enrichment analysis for VPS26A was performed. Cytologic and molecular experiments were further carried out to investigate the role and potential mechanism of VPS26A in PAAD. The mRNA and protein levels of VPS26A were elevated in PAAD tissues. High VPS26A expression was associated with the advanced histological type, tumor stage simplified, smoking status and tumor mutational burden score, and the poor prognosis of PAAD patients. VPS26A expression was significantly correlated with immune infiltration and immunotherapy response. VPS26A-co-expressed genes were mainly enriched in the regulation of cell adhesion and actin cytoskeleton and the immune-response-regulating signaling pathway. Our experiments further demonstrated that VPS26A promoted the proliferation, migration and invasion potentials of PAAD cell lines through activating the EGFR/ERK signaling. Our study suggested that VPS26A could be a potential biomarker and a therapeutic target for PAAD through comprehensive regulation of its growth, migration and immune microenvironment.

How proactive personality promotes online learning performance? Mediating role of multidimensional learning engagement.

Research on online learning effectiveness has experienced a shift towards focusing on learner characteristics or differences. However, little attention has been paid to learners' personality traits, especially those that highly match with the environmental characteristics of online learning. Guided by recent active learning approach and Model of student differences for learning in online education, this study adopts proactive personality (a dispositional tendency to be active, goal-oriented, and not constrained by environmental forces) as a key predictor and examines whether its relationship with online learning performance is mediated by learning engagement as a multidimensional construct. Using a multi-method approach (including self-reports, log file analysis, and content analysis), this study collected both subjective and objective measures of learning engagement from a total of n = 322 undergraduates. Results showed that proactive personality was positively associated with online learning performance. In addition, this association was mediated by all subjective and certain objective measures of learning engagement. Findings contribute to understanding the impact of proactive personality on online learning performance and the interplay of learners' individual factors and learning engagement factors in online learning environments. This study recommends promoting learning engagement to realize learners' online success, especially for those with low levels of proactive personality.

Novel Prenylated Indole Alkaloids with Neuroprotection on SH-SY5Y Cells against Oxidative Stress Targeting Keap1-Nrf2.

Oxidative stress has been implicated in the etiology of Parkinson's disease (PD). Molecules non-covalently binding to the Keap1-Nrf2 complex could be a promising therapeutic approach for PD. Herein, two novel prenylated indole alkaloids asperpenazine (1), and asperpendoline (2) with a scarce skeleton of pyrimido[1,6-a]indole were discovered from the co-cultivated fungi of Aspergillus ochraceus MCCC 3A00521 and Penicillium sp. HUBU 0120. Compound 2 exhibited potential neuroprotective activity on SH-SY5Y cells against oxidative stress. Molecular mechanism research demonstrated that 2 inhibited Keap1 expression, resulting in the translocation of Nrf2 from the cytoplasm to the nucleus, activating the downstream genes expression of HO-1 and NQO1, leading to the reduction in reactive oxygen species (ROS) and the augment of glutathione. Molecular docking and dynamic simulation analyses manifested that 2 interacted with Keap1 (PDB ID: 1X2R) via forming typical hydrogen and hydrophobic bonds with residues and presented less fluctuation of RMSD and RMSF during a natural physiological condition.

Merging C-H Vinylation with Switchable 6π-Electrocyclizations for Divergent Heterocycle Synthesis.

Pyridinium-containing polyheterocycles exhibit distinctive biological properties and interesting electrochemical and optical properties and thus are widely used as drugs, functional materials, and photocatalysts. Here, we describe a unified two-step strategy by merging Rh-catalyzed C-H vinylation with two switchable electrocyclizations, including aza-6π-electrocyclization and all-carbon-6π-electrocyclization, for rapid and divergent access to dihydropyridoisoquinoliniums and dihydrobenzoquinolines. Through computation, the high selectivity of aza-electrocyclization in the presence of an appropriate "HCl" source under either thermal conditions or photochemical conditions is shown to result from the favorable kinetics and symmetries of frontier orbitals. We further demonstrated the value of this protocol by the synthesis of several complex pyridinium-containing polyheterocycles, including the two alkaloids berberine and chelerythrine.

Knocking down USP39 Inhibits the Growth and Metastasis of Non-Small-Cell Lung Cancer Cells through Activating the p53 Pathway.

Ubiquitin-specific protease 39 (USP39), a member of the deubiquitinating enzyme family, has been reported to participate in cytokinesis and metastasis. Previous studies determined that USP39 functions as an oncogenic factor in various types of cancer. Here, we reported that USP39 is frequently overexpressed in human lung cancer tissues and non-small-cell lung cancer (NSCLC) cell lines. USP39 knockdown inhibited the proliferation and colony formation of A549 and HCC827 cells and decreased tumorigenic potential in nude mice. Specifically, knocking down USP39 resulted in cell cycle arrest at G2/M and subsequent apoptosis through the activation of the p53 pathway, including upregulation of p21, cleaved-cas3, cleaved-cas9 and downregulation of CDC2 and CycinB1. Moreover, USP39 knockdown significantly inhibited migration and invasion of A549 and HCC827 cells, also via activation of the p53 pathway, and downregulation of MMP2 and MMP9. Importantly, we verified these results in metastasis models in vivo. Collectively, these results not only establish that USP39 functions as an oncogene in lung cancer, but reveal that USP39 has an essential role in regulating cell proliferation and metastasis via activation of the p53 pathway.

Corilagin inhibits breast cancer growth via reactive oxygen species-dependent apoptosis and autophagy.

Corilagin is a component of Phyllanthus urinaria extract and has been found of possessing anti-inflammatory, anti-oxidative, and anti-tumour properties in clinic treatments. However, the underlying mechanisms in anti-cancer particularly of its induction of cell death in human breast cancer remain undefined. Our research found that corilagin-induced apoptotic and autophagic cell death depending on reactive oxygen species (ROS) in human breast cancer cell, and it occurred in human breast cancer cell (MCF-7) only comparing with normal cells. The expression of procaspase-8, procaspase-3, PARP, Bcl-2 and procaspase-9 was down-regulated while caspase-8, cleaved PARP, caspase-9 and Bax were up-regulated after corilagin treatment, indicating apoptosis mediated by extrinsic and mitochondrial pathways occurred in MCF-7 cell. Meanwhile, autophagy mediated by suppressing Akt/mTOR/p70S6K pathway was detected with an increase in autophagic vacuoles and LC3-II conversion. More significantly, inhibition of autophagy by chloroquine diphosphate salt (CQ) remarkably enhanced apoptosis, while the caspase inhibitor z-VAD-fmk failed in affecting autophagy, suggesting that corilagin-induced autophagy functioned as a survival mechanism in MCF-7 cells. In addition, corilagin induced intracellular reactive oxygen species (ROS) generation, when reduced by ROS scavenger NAC, apoptosis and autophagy were both down-regulated. Nevertheless, in SK-BR3 cell which expressed RIP3, necroptosis inhibitor Nec-1 could not alleviate cell death induced by corilagin, indicating necroptosis was not triggered. Subcutaneous tumour growth in nude mice was attenuated by corilagin, consisting with the results in vitro. These results imply that corilagin inhibits cancer cell proliferation through inducing apoptosis and autophagy which regulated by ROS release.

High expression of Tob1 indicates poor survival outcome and promotes tumour progression via a Wnt positive feedback loop in colon cancer.

Tob1, a Tob/BTG anti-proliferative protein family member, functions as a tumour suppressor in many cancers. Here, we reveal a unique oncogenic role of Tob1 in colon cancer. Tob1 expression was upregulated during colon cancer progression, was significantly correlated with tumour size and tumour differentiation, and was a prognostic indicator of colon cancer. Unlike in other cancers, where nuclear Tob1 performs anticancer activity, Tob1 is predominantly localized in the cytosol of colon cancer cells, where this protein binds and stabilizes ß-catenin to activate Wnt/ß-catenin signalling, which in turn enhances Tob1 expression, thus forming a positive feedback loop to promote cell proliferation. Moreover, Tob1 deficiency led to reduced tumourigenesis in AOM/DSS-treated and ApcMin/+ mice. Our findings provide important insights into a previously unrecognized oncogenic role of Tob1 in colon cancer and suggest that Tob1 is an adverse prognostic factor and therapeutic target for colon cancer.

Berberine inhibits colitis-associated tumorigenesis via suppressing inflammatory responses and the consequent EGFR signaling-involved tumor cell growth.

The anti-inflammatory and anti-tumor effects of berberine, a traditional Chinese medicine, were separately discovered in pathological intestinal tissues. However, whether the anti-inflammatory effect of berberine contributes to its anti-tumor effect on colitis-associated colorectal cancer (CACRC) remains unknown. In the present study, we found that berberine effectively inhibited colitis-associated tumorigenesis and colonic epithelium hyperproliferation in dextran sulfate sodium (DSS)-treated ApcMin/+ mice. A mechanistic study identified that these inhibitory effects of berberine occurred through blocking interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) expression in colonic macrophages. An in vitro study on cell lines identified that berberine treatment of Raw 264.7 macrophages resulted in conditioned media with fewer proliferative effects on a cell line with a heterozygous Apc mutation (Immorto-Min colonic epithelium, IMCE). EGFR-ERK signaling act downstream of berberine/pro-inflammatory cytokines axis to regulate CACRC cell proliferation. Furthermore, in vivo administration of IL-6 to DSS-treated ApcMin/+ mice effectively weakened the inhibitory effects of berberine on tumorigenesis and EGFR-ERK signaling in colon tissues. Altogether, the results of our studies have revealed that berberine inhibits the development of CACRC by interfering with inflammatory response-driven EGFR signaling in tumor cell growth. The findings of this study support the possibility that berberine and other anti-inflammatory drugs may be beneficial in the treatment of CACRC.

Seed Oil of Brucea javanicaInduces Cell Cycle Arrest and Apoptosis via Reactive Oxygen Species-Mediated Mitochondrial Dysfunction in Human Lung Cancer Cells.

Brucea javanica oil (BJO), a traditional herbal medicine extracted from the seeds of B. javanica, has been clinically used to treat non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC) in combination with chemotherapy or radiotherapy in China. However, how BJO exerts this antitumor effect is still largely unknown. Here, effects of BJO on the growth of NSCLC and SCLC cell lines were investigated by the 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenytetrazolium Bromide (MTT) assay, and the results showed that BJO inhibited the proliferation of A549 cells (NSCLC) and H446 cells (SCLC). Further studies revealed that BJO induced G0/G1 arrest partly via regulating p53 and cyclin D1 in these two cell lines. BJO also has pro-apoptotic effect on H446 and A549 cells through mitochondria/caspase-mediated pathway, which was initiated by the accumulation of intracellular reactive oxygen species (ROS). These findings thus revealed the molecular mechanisms underlying the antitumor effect of BJO on SCLC and NSCLC, which may benefit the further clinical application of BJO.

Akt signaling is associated with the berberine-induced apoptosis of human gastric cancer cells.

Despite extensive studies on the antitumor properties of berberine, a small molecule derived from Coptidis rhizoma (Huanglian in Chinese) and many other plants, the underlying mechanism remains poorly understood. Here, we found that berberine-induced cell apoptosis in human gastric cancer cells with the increase of the expression level of cleaved poly ADP-ribose polymerase and caspase-3, and the impairment of mitochondrial membrane potential (Δψm) in berberine-treated gastric cancer cells. In our further studies, the results demonstrated that Akt-related mitochondrial pathway may partly involve in the berberine-induced apoptosis in human gastric cancer cells. Moreover, berberine inhibited the Akt/mTOR/p70S6/S6 pathway in berberine-treated BGC-823 cells. Meanwhile, berberine significantly inhibited the activation of Akt and suppressed tumor growth in xenograft nude mice injected with human gastric cancer cells. Thus, our findings reveal that the underlying mechanism that Akt signaling may contribute to berberine-induced cell apoptosis in gastric cancer cells and might represent an important molecular basis for berberine to act as an anticancer agent.

Berberine ameliorates cartilage degeneration in interleukin-1ß-stimulated rat chondrocytes and in a rat model of osteoarthritis via Akt signalling.

Berberine, a plant alkaloid used in Chinese medicine, has broad cell-protective functions in a variety of cell lines. Chondrocyte apoptosis contributes to the pathogenesis of cartilage degeneration in osteoarthritis (OA). However, little is known about the effect and underlying mechanism of berberine on OA chondrocytes. Here, we assessed the effects of berberine on cartilage degeneration in interleukin-1ß (IL-1ß)-stimulated rat chondrocytes and in a rat model of OA. The results of an MTT assay and western blotting analysis showed that berberine attenuated the inhibitory effect of IL-1ß on the cell viability and proliferating cell nuclear antigen expression in rat chondrocytes. Furthermore, berberine activated Akt, which triggered p70S6K/S6 pathway and up-regulated the levels of aggrecan and Col II expression in IL-1ß-stimulated rat chondrocytes. In addition, berberine increased the level of proteoglycans in cartilage matrix and the thickness of articular cartilage, with the elevated levels of Col II, p-Akt and p-S6 expression in a rat OA model, as demonstrated by histopathological and immunohistochemistry techniques. The data thus strongly suggest that berberine may ameliorate cartilage degeneration from OA by promoting cell survival and matrix production of chondrocytes, which was partly attributed to the activation of Akt in IL-1ß-stimulated articular chondrocytes and in a rat OA model. The resultant chondroprotective effects indicate that berberine merits consideration as a therapeutic agent in OA.

Matrine induces caspase-independent program cell death in hepatocellular carcinoma through bid-mediated nuclear translocation of apoptosis inducing factor.

Matrine, a clinical drug in China, has been used to treat viral hepatitis, cardiac arrhythmia and skin inflammations. Matrine also exhibits chemotherapeutic potential through its ability to trigger cancer cell death. However, the mechanisms involved are still largely unknown. The objective of this study was to investigate the major determinant for the cell death induced by matrine in human hepatocellular carcinoma. We use human hepatocellular carcinoma cell line HepG2 and human hepatocellular carcinoma xenograft in nude mice as models to study the action of matrine in hepatocellular cancers. We found that caspase-dependent and -independent Program Cell Death (PCD) occurred in matrine-treated HepG2 cells, accompanied by the decreasing of mitochondrial transmembrane potential and the increasing ROS production. Further studies showed that AIF released from the mitochondria to the nucleus, and silencing of AIF reduced the caspase-independent PCD induced by matrine. What's more, AIF nuclear translocation, and the subsequent cell death as well, was prevented by Bid inhibitor BI-6C9, Bid-targeted siRNA and ROS scavenger Tiron. In the in vivo study, matrine significantly attenuated tumor growth with AIF release from mitochondria into nucleus in nude mice. These data imply that matrine potently induce caspase-independent PCD in HepG2 cells through Bid-mediated AIF translocation.

Involvement of BID translocation in glycyrrhetinic acid and 11-deoxy glycyrrhetinic acid-induced attenuation of gastric cancer growth.

Glycyrrhetinic acid (GA), the main chemical constituents of licorice, has shown remarkable anticancer activity. However, the side effects limit its widespread use. 11-DOGA is produced through reduction of GA 11-carbonyl to 11-hydroxyl to reduce its side effects, although its anticancer activities are largely unknown. Here, we report that the functional mechanisms of GA and 11-DOGA in gastric cancers, as well as the comparison between these two drugs' pharmacological potential. Firstly, we found that GA and 11-DOGA significantly inhibits the viabilities of gastric cancer cells in dose- and time-dependent manners. Both GA and 11-DOGA induce gastric cancer cells apoptosis and cell cycle arrest in G2 phase by upregulation of p21 and downregulation of cdc2 and cyclin B1. Further studies show that GA and 11-DOGA-induced apoptosis in gastric cancer cells is associated with BID translocation from nucleus to mitochondria. Moreover, GA and 11-DOGA could effectively inhibit tumor formation of gastric cancer cells in nude mice. Comparing with 11-DOGA, GA presents higher toxicity toward gastric cancer cells both in vivo and in vitro. Thus, the elucidation of the functional mechanisms of GA and 11-DOGA-induced attenuation of gastric cancer growth suggests a possible therapeutic role of GA and its derivatives.

Matrine inhibits proliferation and induces apoptosis via BID-mediated mitochondrial pathway in esophageal cancer cells.

Matrine, as a member of Sophora family, is an alkaloid found in plants, and produces plethora pharmacological effects, including anti-cancer effects. However, the mechanism involved remains largely unknown. This study is conducted to investigate the anti-cancer mechanisms of matrine in human esophageal cancer in vitro and in vivo. In human esophageal cancer cell Eca-109, matrine significantly decreased the cell viability in a dose-dependent manner, and induced apoptosis as well as cell cycle arrest in G0/G1 phase by up-regulation of P53 and P21. The expression of several apoptosis-related proteins in cells and tumor tissues were evaluated by Western blot analysis. We found that matrine induced cell apoptosis by down-regulation of the ratio of BCL-2/BID and increasing activation of caspase-9. Further studies indicated that matrine induced apoptosis of Eca-109 was through the mitochondria-mediated internal pathway, but not by death receptor-mediated extrinsic apoptotic pathway, which was confirmed by the fact that Bid translocated from the nucleus to mitochondria during the process of the apoptosis induced by matrine. In vivo study found that matrine effectively inhibited the tumor formation of Eca-109 cells in nude mice. Our study suggests that matrine could serve as a potential novel agent from natural products to treat esophageal cancer.

Pseudo-Eutectic of Isodimorphism to Design Biaxially-Oriented Bio-Based PA56/512 with High Strength, Toughness and Barrier Performances.

The biaxially-oriented PA56/512 has excellent mechanical strength, extensibility and water-oxygen barrier properties and has broad application prospects in green packaging, lithium battery diaphragm and medical equipment materials. The correlation between the aggregation structure evolution and macroscopic comprehensive properties of copolymer PA56/512 under biaxial stretching has been demonstrated in this work. The structure of the random copolymerization sequence was characterized by 13C Nuclear magnetic resonance (NMR). The typical isodimorphism behavior of the co-crystallization system of PA56/512 and its BOPA-56/512 films was revealed by differential scanning calorimetry (DSC) and X-ray diffraction (XRD) tests. And the aggregation structure, including the hydrogen bond arrangement, crystal structure and crystal morphology of PA56/512 before and after biaxial stretching, was investigated by XRD, Fourier-transform infrared spectroscopy (FTIR) and polarized optical microscopy (POM) tests. Furthermore, the effect of the biaxially-oriented stretching process on the mechanical properties of PA56/512 has been demonstrated. In addition, a deep insight into the influence of the structure on the crystallization process and physical-mechanical performance has been presented. The lowest melting point at a 512 content of 60 mol% is regarded as a "eutectic" point of the isodimorphism system. Due to the high disorder of the structural units in the polymer chain, the transition degree of the folded chain (gauche conformation) is relatively lowest when it is straightened to form an extended chain (trans conformation) during biaxially-oriented stretching, and part of the folded chain can be retained. This explains why biaxially stretched PA56/512 has high strength, outstanding toughness and excellent barrier properties at the pseudo-eutectic point. In this study, using the unique multi-scale aggregation structure characteristics of a heterohomodymite polyamide at the pseudo-eutectic point, combined with the new material design scheme and the idea of biaxial-stretching processing, a new idea for customized design of high-performance multifunctional polyamide synthetic materials is provided.

Exo70 Promotes the Invasion of Pancreatic Cancer Cells via the Regulation of Exosomes.

Pancreatic cancer (PC) is an aggressive and fatal malignant tumor, and exosomes have been reported to be closely related to PC invasion and metastasis. Here we found that Exo70, a key subunit of the exocyst complex, promoted PC metastasis by regulating the secretion of tumor exosomes. Clinical sample studies showed that Exo70 was highly expressed in PC and negatively correlated with patients' survival. Exo70 promoted PC cell lines' invasion and migration. Interestingly, knockdown of Exo70, or using an Exo70 inhibitor (ES2) inhibited the secretion of tumor exosomes and increased the accumulation of cellular vesicles. Furthermore, Exo70 was found to accumulate in the exosomes, which then fused with neighboring PC cells and promoted their invasion. Moreover, Exo70 increased the expression of exosomal PD-L1, leading to the immune escape of PC cells. In vivo, knockdown of Exo70 or treatment with ES2 both decreased the tumor metastasis of PC cells in mice. This study provides new insight into the mechanism of invasion and metastasis in PC and identifies Exo70 as a potential prognostic factor and therapeutic target for PC.