Establishment of LAMP-CRISPR/Cas12a for rapid detection of Escherichia coli O157:H7 and one-pot detection.

Escherichia coli O157:H7 is a pathogenic serotype of Escherichia coli. Consumption of food contaminated with E. coli O157:H7 could cause a range of diseases. Therefore, it is of great importance to establish rapid and accurate detection methods for E. coli O157:H7 in food. In this study, based on LAMP and combined with the CRISPR/cas12a system, a sensitive and specific rapid detection method for E. coli O157:H7 was established, and One-Pot detection method was also constructed. The sensitivity of this method could stably reach 9.2 × 10° CFU/mL in pure culture, and the whole reaction can be completed within 1 h. In milk, E. coli O157:H7 with an initial contamination of 7.4 × 10° CFU/mL only needed to be cultured for 3 h to be detected. The test results can be judged by the fluorescence curve or by visual observation under a UV lamp, eliminating instrument limitations and One-Pot detection can effectively prevent the problem of false positives. In a word, the LAMP-CRISPR/cas12a system is a highly sensitive and convenient method for detecting E. coli O157:H7.

Sulindac (K-80003) with nab-paclitaxel and gemcitabine overcomes drug-resistant pancreatic cancer.

The Nab-paclitaxel combined with gemcitabine (AG) regimen is the main chemotherapy regimen for pancreatic cancer, but drug resistance often occurs. Currently, the ability to promote sensitization in drug-resistant cases is an important clinical issue, and the strategy of repurposing conventional drugs is a promising strategy. This study aimed to identify a classic drug that targets chemotherapy resistance's core signaling pathways and combine it with the AG regimen to enhance chemosensitivity. We also aimed to find reliable predictive biomarkers of drug combination sensitivity. Using RNA sequencing, we found that abnormal PI3K/Akt pathway activation plays a central role in mediating resistance to the AG regimen. Subsequently, through internal and external verification of randomly selected AG-resistant patient-derived organoid (PDO) and PDO xenograft models, we discovered for the first time that the classic anti-inflammatory drug sulindac K-80003, an inhibitor of the PI3K/Akt pathway that we focused on, promoted sensitization in half (14/28) of AG-resistant pancreatic ductal adenocarcinoma cases. Through RNA-sequencing, multiplex immunofluorescent staining, and immunohistochemistry experiments, we identified cFAM124A as a novel biomarker through which sulindac K-80003 promotes AG sensitization. Its role as a sensitization marker is explained via the following mechanism: cFAM124A enhances both the mRNA expression of cathepsin L and the activity of the cathepsin L enzyme. This dual effect stimulates the cleavage of RXRα, leading to large amounts of truncated RXRα, which serves as a direct target of K-80003. Consequently, this process results in the pathological activation of the PI3K/Akt pathway. In summary, our study provides a new treatment strategy and novel biological target for patients with drug-resistant pancreatic cancer.

Characterization and transmission of plasmid-mediated multidrug resistance in foodborne Vibrio parahaemolyticus.

Objectives: The purpose of this study was to determine the structural features and transferability of the multidrug-resistance (MDR) plasmid, and resistance phenotypes for the tested antimicrobials in foodborne Vibrio parahaemolyticus. Methods: Plasmids were isolated from a V. parahaemolyticus strain of seafood origin, then sequenced using the Illumina NovaSeq 6000 and PacBio Sequel II sequencing platforms to obtain the complete genome data. Characterization of the MDR plasmid pVP52-1, including determination of antimicrobial resistance genes (ARGs), plasmid incompatibility groups, and transferability, was carried out. Results: V. parahaemolyticus strain NJIFDCVp52 contained two circular chromosomes and two circular plasmids (pVP52-1 and pVP52-2). Plasmid typing indicated that pVP52-1 belonged to the incompatibility group IncA/C2 and the sequence type pST3. pVP52-1 carried 12 different ARGs, an IS110-composite transposon consisting of aac(6')-Ib-cr, qnrVC1, aac(6')-Ib, dfrA14, and the IS26-mphA-IS6100 unit flanked by inverted sequences of IS5075 and IS4321. pVP52-2 carried no ARGs. A plasmid elimination assay showed that only pVP52-1 and its ARGs were lost, the loss of resistance to several antimicrobials, causing a change from the ampicillin-ampicillin/sulbactam-cefazolin-cefoxitin-ceftazidime-cefotaxime-imipenem-trimethoprim/sulfamethoxazole resistance pattern to the ampicillin resistance pattern. In accordance, a conjugation transfer assay showed that only pVP52-1 and its ARGs were horizontally transferred, leading to increased antimicrobial resistance in Escherichia coli strain EC600, causing a change from the ampicillin-nalidixic acid resistance pattern to the ampicillin-ampicillin/sulbactam-cefazolin-cefoxitin-ceftazidime-cefotaxime-imipenem-nalidixic acid-chloramphenicol-tetracycline-trimethoprim/sulfamethoxazole-azithromycin resistance pattern. Further transferability experiments revealed that pVP52-1 could be transferred to other enterobacterial strains of E. coli and Salmonella. Discussion: This study emphasizes the urgent need for continued surveillance of resistance plasmids and changes in antimicrobial resistance profiles among the V. parahaemolyticus population.

Necroptosis enhances 'don't eat me' signal and induces macrophage extracellular traps to promote pancreatic cancer liver metastasis.

Pancreatic ductal adenocarcinoma (PDAC) is a devastating cancer with dismal prognosis due to distant metastasis, even in the early stage. Using RNA sequencing and multiplex immunofluorescence, here we find elevated expression of mixed lineage kinase domain-like pseudo-kinase (MLKL) and enhanced necroptosis pathway in PDAC from early liver metastasis T-stage (T1M1) patients comparing with non-metastatic (T1M0) patients. Mechanistically, MLKL-driven necroptosis recruits macrophages, enhances the tumor CD47 'don't eat me' signal, and induces macrophage extracellular traps (MET) formation for CXCL8 activation. CXCL8 further initiates epithelial-mesenchymal transition (EMT) and upregulates ICAM-1 expression to promote endothelial adhesion. METs also degrades extracellular matrix, that eventually supports PDAC liver metastasis. Meanwhile, targeting necroptosis and CD47 reduces liver metastasis in vivo. Our study thus reveals that necroptosis facilitates PDAC metastasis by evading immune surveillance, and also suggest that CD47 blockade, combined with MLKL inhibitor GW806742X, may be a promising neoadjuvant immunotherapy for overcoming the T1M1 dilemma and reviving the opportunity for radical surgery.

Targeting the MCP-GPX4/HMGB1 Axis for Effectively Triggering Immunogenic Ferroptosis in Pancreatic Ductal Adenocarcinoma.

Induction of ferroptosis can inhibit cancer cells in vitro, however, the role of ferroptosis in treatment in vivo is controversial. The immunosuppressive cells activated by the ferroptotic tumor cells can promote the growth of residual tumor cells, hindering the application of ferroptosis stimulation in tumor treatment. In this study, a new strategy is aimed to be identified for effectively triggering immunogenic ferroptosis in pancreatic ductal adenocarcinoma (PDAC) and simultaneously stimulating antitumor immune responses. Toward this, several molecular and biochemical experiments are performed using patient-derived organoid models and a KPC mouse model (LSL-KrasG12D /+, LSL-Trp53R172H/+, Pdx-1-Cre). It is observed that the inhibition of macrophage-capping protein (MCP) suppressed the ubiquitin fold modifier (UFM)ylation of pirin (PIR), a newly identified substrate of UFM1, thereby decreasing the transcription of GPX4, a marker of ferroptosis, and promoting the cytoplasmic transportation of HMGB1, a damage-associated molecular pattern. GPX4 deficiency triggered ferroptosis, and the pre-accumulated cytosolic HMGB1 is released rapidly. This altered release pattern of HMGB1 facilitated the pro-inflammatory M1-like polarization of macrophages. Thus, therapeutic inhibition of MCP yielded dual antitumor effects by stimulating ferroptosis and activating antitumor pro-inflammatory M1-like macrophages. The nanosystem developed for specifically silencing MCP is a promising tool for treating PDAC.

Escherichia coli-Induced cGLIS3-Mediated Stress Granules Activate the NF-κB Pathway to Promote Intrahepatic Cholangiocarcinoma Progression.

Patients with concurrent intrahepatic cholangiocarcinoma (ICC) and hepatolithiasis generally have poor prognoses. Hepatolithiasis is once considered the primary cause of ICC, although recent insights indicate that bacteria in the occurrence of hepatolithiasis can promote the progression of ICC. By constructing in vitro and in vivo ICC models and patient-derived organoids (PDOs), it is shown that Escherichia coli induces the production of a novel RNA, circGLIS3 (cGLIS3), which promotes tumor growth. cGLIS3 binds to hnRNPA1 and G3BP1, resulting in the assembly of stress granules (SGs) and suppression of hnRNPA1 and G3BP1 ubiquitination. Consequently, the IKKα mRNA is blocked in SGs, decreasing the production of IKKα and activating the NF-κB pathway, which finally results in chemoresistance and produces metastatic phenotypes of ICC. This study shows that a combination of Icaritin (ICA) and gemcitabine plus cisplatin (GP) chemotherapy can be a promising treatment strategy for ICC.

Rhodium-Catalyzed [7 + 1] Cycloaddition of Exocyclic 1,3-Dienylcyclopropanes and Carbon Monoxide.

A rhodium-catalyzed [7 + 1] reaction of exocyclic 1,3-dienylcyclopropanes and carbon monoxide has been developed to synthesize eight-membered carbocycle-embedded bicyclic and tricyclic molecules. In addition, ab initio calculations were conducted to reveal the reaction mechanism.

Establishment of real-time fluorescence and visual LAMP for rapid detection of Escherichia coli O157:H7 and kits construction.

Escherichia coli O157:H7 is a common pathogenic bacterium in food and water that can pose a threat to human health. The aim of this study was to develop loop-mediated isothermal amplification (LAMP) method for the detection of E. coli O157:H7 in food based on the specific gene Ecs_2840 and to construct rapid detection kits based on the established methods. Specifically, we established two methods of real-time fluorescent LAMP (RT-LAMP) and visual LAMP with calcein as an indicator. In pure bacterial culture, the cell sensitivity and genomic sensitivity of the RT-LAMP kit were 8.8 × 100 CFU ml-1 and 4.61 fg µl-1, respectively. The sensitivity of the visual LAMP kit was 2.35 × 100 CFU ml-1 and 4.61 fg µl-1. Both kits had excellent specificity and anti-interference performance. In addition, milk inoculated with 2.26 × 100 CFU ml-1E. coli O157:H7 could be detected within the reaction time after enrichment for 3 h. The results showed that the LAMP kits were rapid, sensitive, and specific for the detection of E. coli O157:H7 in food and had good application prospects in food safety surveillance.

A Novel Trojan Horse Nanotherapy Strategy Targeting the cPKM-STMN1/TGFB1 Axis for Effective Treatment of Intrahepatic Cholangiocarcinoma.

Intrahepatic cholangiocarcinoma (ICC) is characterized by its dense fibrotic microenvironment and highly malignant nature, which are associated with chemotherapy resistance and very poor prognosis. Although circRNAs have emerged as important regulators in cancer biology, their role in ICC remains largely unclear. Herein, a circular RNA, cPKM is identified, which is upregulated in ICC and associated with poor prognosis. Silencing cPKM in ICC cells reduces TGFB1 release and stromal fibrosis, inhibits STMN1 expression, and suppresses ICC growth and metastasis, moreover, it also leads to overcoming paclitaxel resistance. This is regulated by the interactions of cPKM with miR-199a-5p or IGF2BP2 and by the ability of cPKM to stabilize STMN1/TGFB1 mRNA. Based on these findings, a Trojan horse nanotherapy strategy with co-loading of siRNA against cPKM (si-cPKM) and paclitaxel (PTX) is developed. The siRNA/PTX co-loaded nanosystem (Trojan horse) efficiently penetrates tumor tissues, releases si-cPKM and paclitaxel (soldiers), promotes paclitaxel sensitization, and suppresses ICC proliferation and metastasis in vivo. Furthermore, it alleviates the fibrosis of ICC tumor stroma and reopens collapsed tumor vessels (opening the gates), thus enhancing the efficacy of the standard chemotherapy regimen (main force). This novel nanotherapy provides a promising new strategy for ICC treatment.

Analyzing molecular typing and clinical application of immunogenic cell death-related genes in hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is considered one of the most common cancers, characterized by low early detection and high mortality rates, and is a global health challenge. Immunogenic cell death (ICD) is defined as a specific type of regulated cell death (RCD) capable of reshaping the tumor immune microenvironment by releasing danger signals that trigger immune responses, which would contribute to immunotherapy. METHODS: The ICD gene sets were collected from the literature. We collected expression data and clinical information from public databases for the HCC samples in our study. Data processing and mapping were performed using R software to analyze the differences in biological characteristics between different subgroups. The expression of the ICD representative gene in clinical specimens was assessed by immunohistochemistry, and the role of the representative gene in HCC was evaluated by various in vitro assays, including qRT-PCR, colony formation, and CCK8 assay. Lasso-Cox regression was used to screen prognosis-related genes, and an ICD-related risk model (ICDRM) was constructed. To improve the clinical value of ICDRM, Nomograms and calibration curves were created to predict survival probabilities. Finally, the critical gene of ICDRM was further investigated through pan-cancer analysis and single-cell analysis. RESULTS: We identified two ICD clusters that differed significantly in terms of survival, biological function, and immune infiltration. As well as assessing the immune microenvironment of tumors in HCC patients, we demonstrate that ICDRM can differentiate ICD clusters and predict the prognosis and effectiveness of therapy. High-risk subpopulations are characterized by high TMB, suppressed immunity, and poor survival and response to immunotherapy, whereas the opposite is true for low-risk subpopulations. CONCLUSIONS: This study reveals the potential impact of ICDRM on the tumor microenvironment (TME), immune infiltration, and prognosis of HCC patients, but also a potential tool for predicting prognosis.

Effect and regulation of fatty acids on bacillomycin D synthesis.

Bacillomycin D is a cyclic antimicrobial lipopeptide that has excellent antifungal effects, but its application is limited due to its low yield. At present, it is not clear whether fatty acids regulate the synthesis of bacillomycin D. Therefore, the effects of nine fatty acids on the yield of bacillomycin D produced by Bacillus amyloliquefaciens fmbJ were studied. The results showed that sodium propionate, propionic acid, and butyric acid could increase the yield of bacillomycin D by 44, 40, and 10%, respectively. Reverse transcription polymerase chain reaction (RT-PCR) was used to detect the expression levels of bacillomycin D synthesis gene, signaling factors and genes related to fatty acid metabolism, so as to explore the mechanism of sodium propionate regulating bacillomycin D synthesis. In conclusion, sodium propionate could accelerate the tricarboxylic acid cycle and promoted spore formation, cell movement, the secretion of extracellular protease and the transcription of bacillomycin D synthesis gene by upregulating the expression of signal factors degU, degQ, sigH, sigM and spo0A and ultimately promoted the synthesis of bacillomycin D. In this study, the mechanism of sodium propionate increasing bacillomycin D production was explored from multiple perspectives, which provided theoretical support for the large-scale production of bacillomycin D and was expected to promote its wide application in food, agriculture and medicine fields.

Induced expression of CCL19 promotes the anti-tumor ability of CAR-T cells by increasing their infiltration ability.

Background: Chimeric antigen receptor-engineered T cell (CAR-T) therapy has shown promising potential for anti-cancer treatment. However, for pancreatic ductal adenocarcinoma (PDAC), the lack of infiltrative ability of these CAR-T cells leads to sub-optimal treatment outcome. Methods: Chemokine (C-C motif) ligand 19 (CCL19), the expression of which is regulated by the nuclear factor of activated T cell pathway, was transfected into targeting mesothelin CAR-T cells (mesoCAR-N19) using NFAT regulating element. It was expressed in activated CAR-T cells by OKT3 or mesothelin+ tumor cells but not in inactive cells. The migratory ability of these CAR-T cells was then measured. Subsequently, functional identification of these CAR-T cells was performed in vivo. In addition, the tumor lytic activity and proliferation of the CAR-T cells were measured in vitro. The degree of CAR-T cell infiltration and distribution into the PDAC tumors was examined using the immunohistochemical staining of hCD3 and the detection of CAR gene copy number by quantitative PCR. Finally, the functional assessment of chemokine (C-C motif) receptor 7 knock-out was performed in the CAR-T cells. Results: Through in vitro Transwell assays, it was demonstrated that mesoCAR-N19 can be specifically expressed in CAR-T cells activated by tumor cells compared with conventional mesothelin CAR-T (mesoCAR) cells. We also observed that upregulating the expression of CCL19 can increase the recruitment of additional T cells. In vivo studies subsequently revealed that this highly specific recruitment of T cell infiltration is associated with enhanced tumor-suppressive activities downstream. Conclusion: Induced expression of CCL19 can promote the anti-tumor ability of CAR-T cells by increasing their infiltrative ability. This study potentially uncovered novel method of activating CAR-T cells to enhance their infiltrative capacities, which offers a novel direction for PDAC treatment.

Deletion of COM donor and acceptor domains and the interaction between modules in bacillomycin D produced by Bacillus amyloliquefaciens.

Bacillomycin D is a cyclic lipopeptide produced by Bacillus amyloliquefaciens fmbJ. At present, no relevant report has described the combinatorial biosynthesis of bacillomycin D. Due to the strong biosynthetic potential of the communication-mediating (COM) domains, its crosstalk between NRPS subunits has been studied to some extent, but the interaction of COM domain between modules is rarely reported. Therefore, in this study, we conducted the combinatorial biosynthesis of bacillomycin D through the deletion of the COM donor and acceptor domains between the modules and elucidated the interaction between the NRPS modules. The results showed that the deletion of the donor domain between modules 2 and 3 did not affect catalysis by upstream modules, but prevented downstream modules from catalysing the extension of the lipopeptide product, ultimately resulting in mutant complexes that could form linear dipeptides with the sequence ß-NH2FA-Asn-Tyr. However, the engineered hybrid bacillomycin D NRPSs lacking the donor domains between modules 3 and 4 and modules 6 and 7 could form multiple assembly lines that produced bacillomycin D and its analogs (linear tripeptides, cyclic hexapeptides and linear hexapeptides). In addition, all the acceptor domain deletion strains failed to produce bacillomycin D, only truncated peptides produced by module interruption (except for the acceptor domain deletion strains between modules 3 and 4, which also produced cyclic hexapeptides). In conclusion, deletion of the inter-module donor domains led to a more flexible hybrid biosynthetic system for the production of diverse peptide products; compared with the inter-subunit donor domain deletion strains that could only produce truncated peptides, the former had a greater biosynthetic capacity. Meanwhile, the acceptor domains between modules were an important part of module-module interactions and efficient communication within bacillomycin D synthetase.

SRSF3-mediated regulation of N6-methyladenosine modification-related lncRNA ANRIL splicing promotes resistance of pancreatic cancer to gemcitabine.

Serine/arginine-rich splicing factor 3 (SRSF3) regulates mRNA alternative splicing of more than 90% of protein-coding genes, providing an essential source for biological versatility. This study finds that SRSF3 expression is associated with drug resistance and poor prognosis in pancreatic cancer. We also find that SRSF3 regulates ANRIL splicing and m6A modification of ANRIL in pancreatic cancer cells. More importantly, we demonstrate that m6A methylation on lncRNA ANRIL is essential for the splicing. Moreover, our results show that SRSF3 promotes gemcitabine resistance by regulating ANRIL's splicing and ANRIL-208 (one of the ANRIL spliceosomes) can enhance DNA homologous recombination repair (HR) capacity by forming a complex with Ring1b and EZH2. In conclusion, this study establishes a link between SRSF3, m6A modification, lncRNA splicing, and DNA HR in pancreatic cancer and demonstrates that abnormal alternative splicing and m6A modification are closely related to chemotherapy resistance in pancreatic cancer.

[Distribution and Environmental Significance of Rare Earth Elements in Typical Protected Vegetable Soil, Northern China].

The concentrations of rare earth elements (REEs) in protected vegetable soils in Wuqing district of Tianjin City, Jinzhong district of Shanxi Province, Shenyang district of Liaoning Province, and Wulanchabu district of Inner Mongolia Autonomous Region in northern China were measured to analyze the change characteristics of soil REEs in the process of protected vegetable cultivation. Additionally, we sought to use the REEs parameters to trace the feasibility of characterizing the interference of human activities on the soil ecological environment. The results showed that the total content of REEs (REE) in the topsoil of protected vegetable fields ranged from 146.52 to 158.76 mg·kg-1, with an average of 152.34 mg·kg-1 in Shenyang; 92.16 to 137.69 mg·kg-1, with an average of 115.03 mg·kg-1in Wuqing; 91.38 to 118.84 mg·kg-1, with an average of 108.03 mg·kg-1 in Wulanchabu; and 97.62 to 111.27 mg·kg-1, with an average of 102.43 mg·kg-1in Jinzhong. The REEs distribution patterns in the soils of the four areas, standardized with chondrite, characterized by a right tilt, showed that light rare earth elements were obviously enriched in the soil, demonstrated by the ratios of LREE/HREE and (La/Yb) N, which were greater than 6 and 7, respectively. The values of (La/Sm)N in the soils were higher than 3, suggesting that there was an obvious fractionation between light rare earth elements, whereas the values of (Gd/Yb)N were between 1-2, and there was a weak fractionation between heavy rare earth elements. The values of δEu in the soils were between 0.56 and 0.61, showing that Eu had a negative abnormality. The values of δCe were between 0.89 and 1.11, showing that Ce had no abnormality or weak positive abnormality. The higher LREE/HREE and (La/Yb)N in protected vegetable soil than that in open-air vegetable soil indicated the increasing differentiation degree between light and heavy rare earth elements in protected vegetable soil. The lower (La/Sm)N in protected vegetable soils indicated the reduction in the differentiation among light rare earth elements in soil. Higher δCe values and lower δEu values suggested that Ce and Eu were relatively enriched and depleted, respectively, during vegetable planting. The REE, LREE, (La/Sm)N, and δEu in protective soil decreased with the number of cultivation years, whereas the (Gd/Yb)N and δCe increased, but the HREE values did not change significantly. There was a significant correlation between δCe, δEu, (La/Yb)N, (Gd/Yb)N, and soil bulk density, soil moisture content, and soil organic matter in Tianjin protected vegetable soils, showing preliminarily that rare earth elements can be used as tracer elements to characterize the interference intensity of human activities on soil.

Circular RNA circ-MTHFD1L induces HR repair to promote gemcitabine resistance via the miR-615-3p/RPN6 axis in pancreatic ductal adenocarcinoma.

BACKGROUND: Chemoresistance of pancreatic cancer is the main reason for the poor treatment effect of pancreatic cancer patients. Exploring chemotherapy resistance-related genes has been a difficult and hot topic of oncology. Numerous studies implicate the key roles of circular RNAs (circRNAs) in the development of pancreatic cancer. However, the regulation of circRNAs in the process of pancreatic ductal adenocarcinoma (PDAC) chemotherapy resistance is not yet fully clear. METHODS: Based on the cross-analysis of the Gene Expression Omnibus (GEO) database and the data of our center, we explored a new molecule, hsa_circ_0078297 (circ-MTHFD1L), related to chemotherapy resistance. QRT-PCR was used to detect the expression of circRNAs, miRNAs, and mRNAs in human PDAC tissues and their matched normal tissues. The interaction between circ-MTHFD1L and miR-615-3p/RPN6 signal axis was confirmed by a series of experiments such as Dual-luciferase reporter assay, fluorescence in situ hybridization (FISH) RNA immunoprecipitation (RIP) assays. RESULTS: Circ-MTHFD1L was significantly increased in PDAC tissues and cells. And in PDAC patients, the higher the expression level of circ-MTHFD1L, the worse the prognosis. Mechanism analysis showed that circ-MTHFD1L, as an endogenous miR-615-3p sponge, upregulates the expression of RPN6, thereby promoting DNA damage repair and exerting its effect on enhancing gemcitabine chemotherapy resistance. More importantly, we also found that Silencing circ-MTHFD1L combined with olaparib can increase the sensitivity of pancreatic cancer to gemcitabine. CONCLUSION: Circ-MTHFD1L maintains PDAC gemcitabine resistance through the miR-615-3p/RPN6 signal axis. Circ-MTHFD1L may be a molecular marker for the effective treatment of PDAC.

CLK1/SRSF5 pathway induces aberrant exon skipping of METTL14 and Cyclin L2 and promotes growth and metastasis of pancreatic cancer.

BACKGROUND: Both aberrant alternative splicing and m6A methylation play complicated roles in the development of pancreatic cancer (PC), while the relationship between these two RNA modifications remains unclear. METHODS: RNA sequencing (RNA-seq) was performed using 15 pairs of pancreatic ductal adenocarcinoma (PDAC) tissues and corresponding normal tissues, and Cdc2-like kinases 1 (CLK1) was identified as a significantly upregulated alternative splicing related gene. Real-time quantitative PCR (qPCR) and western blotting were applied to determine the CLK1 levels. The prognostic value of CLK1 was elucidated by Immunohistochemistry (IHC) analyses in two independent PDAC cohorts. The functional characterizations and mechanistic insights of CLK1 in PDAC growth and metastasis were evaluated with PDAC cell lines and nude mice. SR-like splicing factors5250-Ser (SRSF5250-Ser) was identified as an important target phosphorylation site by phosphorylation mass spectrometry. Through transcriptome sequencing, Methyltransferase-like 14exon10 (METTL14exon10) and Cyclin L2exon6.3 skipping were identified as key alternative splicing events regulated by the CLK1-SRSF5 axis. RIP assays, RNA-pulldown and CLIP-qPCR were performed to confirm molecular interactions and the precise binding sites. The roles of the shift of METTL14exon 10 and Cyclin L2exon6.3 skipping were surveyed. RESULTS: CLK1 expression was significantly increased in PDAC tissues at both the mRNA and protein levels. High CLK1 expression was associated with poor prognosis. Elevated CLK1 expression promoted growth and metastasis of PC cells in vitro and in vivo. Mechanistically, CLK1 enhanced phosphorylation on SRSF5250-Ser, which inhibited METTL14exon10 skipping while promoted Cyclin L2exon6.3 skipping. In addition, aberrant METTL14exon 10 skipping enhanced the N6-methyladenosine modification level and metastasis, while aberrant Cyclin L2exon6.3 promoted proliferation of PDAC cells. CONCLUSIONS: The CLK1/SRSF5 pathway induces aberrant exon skipping of METTL14 and Cyclin L2, which promotes growth and metastasis and regulates m6A methylation of PDAC cells. This study suggests the potential prognostic value and therapeutic targeting of this pathway in PDAC patients.

SHCBP1 interacting with EOGT enhances O-GlcNAcylation of NOTCH1 and promotes the development of pancreatic cancer.

O-GlcNAcylation is important in the development and progression of pancreatic ductal adenocarcinoma (PDAC). The glycosyltransferase EGF domain-specific O-linked GlcNAc transferase (EOGT) acts as a key participant in glycosylating NOTCH1. High-throughput sequencing of specimens from 30 advanced PDAC patients identified SHCBP1 and EOGT as factors of poor prognosis. We hypothesized that they could mediate PDAC progression by influencing NOTCH1 O-GlcNAcylation. Thus, 186 PDAC tissue specimens were immunostained for EOGT and SHCBP1. Pancreatic cancer cell lines and nude mouse models were used for in vitro and in vivo experiments. Respectively, The protein expression of EOGT and SHCBP1 was significantly elevated and correlated with worse prognosis in PDAC patients. In vitro, SHCBP1 overexpression promoted pancreatic cancer cell proliferation, migration and invasion, while knocking down SHCBP1 and EOGT inhibited these malignant processes. In vivo data showed that SHCBP1 overexpression promoted xenograft growth and lung metastasis and shortened survival in mice, whereas knocking down either EOGT or SHCBP1 expression suppressed xenograft growth and metastasis and prolonged survival. We further clarified the molecular mechanisms by which EOGT and SHCBP1 enhance the O-GlcNAcylation of NOTCH1, Subsequently promoting the nuclear localization of the Notch intracellular domain (NICD) and inhibiting the transcription of E-cadherin and P21 in pancreatic cancer cells.

A sustained zero-order release carrier for long-acting, peakless basal insulin therapy.

Basal insulin therapy plays a key role in diabetes management. An ideal therapy should mimic the steady physiologic basal insulin secretion, and provide a peak-free, prolonged and steady insulin supply. Herein, a new drug carrier was designed by first PEGylating insulin and then incorporating the conjugate into layer-by-layer assembled films with tannic acid (TA). Because PEG-insulin and TA in the films were linked with reversible, dynamic hydrogen bonds, the films disintegrate gradually when soaked in aqueous solutions, and thus release PEG-insulin into the media. In vitro release tests revealed that the release of PEG-insulin follows a zero-order kinetics. Theoretical analysis based on the unique release mechanism also supports a zero-order kinetics. In vivo tests using a streptozotocin-induced diabetic rat model demonstrated that subcutaneous implantation of the film could maintain a steady plasma drug level and hence maintain a fasting blood glucose level (BGL) close to normal. The duration of action depends on the thickness of the film. Using a 50-bilayer film, fasting BGL was kept within the normoglycemic range for ∼16 days. Initial burst release, a severe problem for other release systems, was successfully avoided.

Injectable Carrier for Zero-Order Release of Salmon Calcitonin.

Salmon calcitonin (sCT) was developed as an antiresorptive for the management of osteoporosis, a major public health threat worldwide. However, its clinical application was severely limited by its short half-life. Herein, an injectable drug carrier, that is, polylactic acid (PLA) microspheres coated with TA/PEG-sCT (TA: tannic acid. PEG-sCT: PEGylated sCT) layer-by-layer (LBL) films, was designed. An in vitro test demonstrated that, unlike previously developed drug carriers, the new carrier released PEG-sCT at a constant rate. The unique zero-order release kinetics originates from its unique drug release mechanism, that is, drug release via gradual disintegration of the dynamic TA/PEG-sCT LBL film. The small size of the PLA microspheres allows the carrier to be administrated via subcutaneous injection. An in vivo test demonstrated that a single injection of the carrier could maintain the plasma level of PEG-sCT stable for an extended period and thus induced a stable reduction in the plasma calcium level in rats. Using a rat model of osteoporosis induced by ovariectomy, it was further demonstrated that a single injection of the new carrier gave better therapeutic outcomes than daily injection of sCT of the same dose, thanks to the improved pharmacokinetic profile. Given the advantages of the new carrier, including facile subcutaneous administration, less frequent dosing, no initial burst release, no peak plasma drug level, and improved therapeutic outcomes, it is expected to have potential in long-term management of osteoporosis and other metabolic bone diseases.