Identification of m6A modification patterns and RBM15 mediated macrophage phagocytosis in pancreatic cancer: An integrative analysis.

Pancreatic cancer (PC) responds weakly to conventional immunotherapy. RNA N6-methyladenosine (m6A) modification has an essential role in the immune response, while its potential role in PC tumor microenvironment (TME) immune cell infiltration remains unknown. In this study, we thoroughly assessed the m6A modification patterns of 472 PC samples using 19 m6A regulators, and we systematically correlated these modification patterns with TME immune cell infiltration characteristics. We also created the m6Ascore and evaluated the m6A modification patterns of individual tumors, identified three different m6A modification patterns, and explored the role of the important m6A "writer" RBM15 in the regulation of macrophage function in PC. Two independent PC cohorts confirmed that patients with higher m6Ascore showed significant survival benefit. We verified that knockdown of RBM15 has the ability to inhibit PC growth and to promote macrophage infiltration and enhance phagocytosis of PC cells by macrophages. In conclusion, m6A modifications play a non-negligible role in the formation of TME diversity and complexity in PC. We reveal that inhibition of RBM15 suppresses PC development and modulates macrophage phagocytosis, and provide a more effective immunotherapeutic strategy for PC.

Genomic analysis of Cobetia sp. D5 reveals its role in marine sulfur cycling.

Dimethylsulfoniopropionate (DMSP) is one of the most abundant sulfur-containing organic compounds on the earth, which is an important carbon and sulfur source and plays an important role in the global sulfur cycle. Marine microorganisms are an important group involved in DMSP metabolism. The strain Cobetia sp. D5 was isolated from seawater samples in the Yellow Sea area of Qingdao during an algal bloom. There is still limited knowledge on the capacity of DMSP utilization of Cobetia bacteria. The study reports the whole genome sequence of Cobetia sp. D5 to understand its DMSP metabolism pathway. The genome of Cobetia sp. D5 consists of a circular chromosome with a length of 4,233,985 bp and the GC content is 62.56%. Genomic analysis showed that Cobetia sp. D5 contains a set of genes to transport and metabolize DMSP, which can cleave DMSP to produce dimethyl sulphide (DMS) and 3-Hydroxypropionyl-Coenzyme A (3-HP-CoA). DMS diffuses into the environment to enter the global sulfur cycle, whereas 3-HP-CoA is catabolized to acetyl CoA to enter central carbon metabolism. Thus, this study provides genetic insights into the DMSP metabolic processes of Cobetia sp. D5 during a marine algal bloom, and contributes to the understanding of the important role played by marine bacteria in the global sulfur cycle.

Role of endoscopic ultrasound in the evaluation of unexplained extrahepatic bile duct dilatation.

OBJECTIVE: This study was performed to assess the diagnostic performance of endoscopic ultrasonography (EUS) in patients with extrahepatic bile duct (EBD) dilatation and develop a novel model incorporating EUS-based signature with clinical parameters for distinguishing the malignant dilation of EBD. METHODS: The EUS data and clinical parameters of the patients were collected and analyzed retrospectively. First, we evaluated the diagnostic performance of EUS in detecting the cause of EBD dilatation. Then, we performed univariate and multivariate binary logistic regression analyses based on clinical and EUS features. Finally, a nomogram was established to aid in distinguishing between malignant dilation and noncalculous benign dilatation of EBD in patients. RESULTS: A total of 184 patients were enrolled. For the diagnosis of malignant dilation, EUS achieved an accuracy of 90.76%, sensitivity of 85.96%, and specificity of 92.91%. For the diagnosis of calculous dilation, EUS achieved an accuracy of 100%, sensitivity of 100%, and specificity of 100%. For the diagnosis of noncalculous benign dilatation, EUS achieved an accuracy of 90.76%, sensitivity of 90.90%, and specificity of 90.58%. Multivariable logistic regression analyses indicated that abnormal liver function test, elevated tumor markers, and EUS findings were the well-diagnostic factors of malignant EBD dilation. The nomogram established by these factors showed good calibration and discrimination. CONCLUSION: EUS is a useful examinational modality in the work-up of EBD dilatation. In combination with abnormal liver function test and elevated tumor markers, EUS may provide additional information for the detection of malignant dilation of EBD and should be further investigated.

N6 -methyladenosine RNA demethylase FTO regulates extracellular matrix-related genes and promotes pancreatic cancer cell migration and invasion.

Pancreatic cancer (PC) is a deadly disease, and its post-transcriptional gene regulation mechanism remains unclear. The abundant extracellular matrix (ECM) in PC plays an important role in tumor progression. This study is the first to focus on the role of N6 -methyladenosine (m6 A) RNA methylation, an emerging post-transcriptional regulatory mechanism, in the regulation of the ECM in PC. Here, we found that ADAMTS2, COL12A1, and THBS2 were associated with the prognosis of PC by comprehensive analysis of differentially expressed genes from two independent GEO expression profile datasets and m6 A-related genes in RMVar database (PAAD). GO and KEGG enrichment analysis found that these m6 A-related targets are chiefly functionally concentrated in the ECM region and participate in ECM signal transduction. Correlation analysis revealed that these genes can be regulated by the demethylase FTO. Cell biology function assays showed that knockdown of FTO-inhibited PC cell abilities to migrate and invade in vitro. qRT-PCR and MeRIP experiments showed that after knockdown of FTO, the mRNA levels of ADAMTS2, COL12A1, and THBS2 and their m6 A modification levels were significantly reduced. These results indicate that m6 A RNA demethylation is associated with the regulation of ECM in PC. In conclusion, m6 A RNA demethylase FTO regulates ECM-related genes and promotes PC cell abilities to migrate and invade, our work provides a new perspective on the molecular mechanism of PC progression.

Long non­coding RNA 01614 hyperactivates WNT/ß­catenin signaling to promote pancreatic cancer progression by suppressing GSK­3ß.

Pancreatic cancer (PC) is a lethal type of cancer for which effective therapies are limited. Long non­coding RNAs (lncRNAs) represent a critical type of regulator category, mediating the tumorigenesis and development of various tumor types, including PC. However, the expression patterns and functions of numerous lncRNAs in PC remain poorly understood. In the present study, linc01614 was identified as a PC­related lncRNA. linc01614 was notably upregulated in PC tissues and cell lines and was associated with the poor disease­free survival of patients with PC according to the analysis of The Cancer Genome Atlas­derived datasets. Functionally, linc01614 knockdown suppressed PC cell proliferation, migration and invasion in vitro, and inhibited tumor proliferation in vitro and in vivo. Mechanistically, linc01614 overexpression stabilized the level of ß­catenin protein to hyperactivate the WNT/ß­catenin signaling pathway in PC cells. Further analyses revealed that linc01614 bound to GSK­3ß and perturbed the interaction between GSK­3ß and AXIN1, thereby preventing the formation of the ß­catenin degradation complex and reducing the degradation of ß­catenin. In summary, the present findings reveal that linc01614 may function as an oncogene and promote the progression of PC and may thus be considered as a potential therapeutic target in the future.

Tumorigenic and immunological roles of Heat shock protein A2 in pancreatic cancer: a bioinformatics analysis.

OBJECTIVE: Heat shock protein A2 has been reported to be tightly associated with tumorigenesis and tumor progression. This study aimed to determine the oncogenic and immunological roles of Heat shock protein A2 in pancreatic cancer by bioinformatics. METHODS: Expression of Heat shock protein A2 in tumorous and normal specimens of pancreatic cancer was analyzed using the Cancer Genome Atlas and the Cancer Genome Atlas + Genotype-Tissue Expression data sets, respectively. Relationships of Heat shock protein A2 expression with immune infiltrates in pancreatic cancer were assessed. Heat shock protein A2-associated coexpressed genes in pancreatic cancer were obtained, followed by the implementation of enrichment analysis. RESULTS: The data demonstrated that Heat shock protein A2 was significantly overexpressed in tumorous samples compared with normal samples. Heat shock protein A2 expression was remarkably positively interrelated with CD8+ T cell, neutrophil, dendritic cell, and macrophage, but not with CD4+ T and B cells. Heat shock protein A2 expression was markedly positively relevant to both cancer-associated fibroblast and endothelial cell. Enrichment data revealed that Heat shock protein A2 was intimately involved in the tumorigenesis and progression of pancreatic cancer. CONCLUSION: Heat shock protein A2 is upregulated in pancreatic cancer and is closely associated with tumor immunity and aggressive progression.

m6A RNA demethylase FTO promotes the growth, migration and invasion of pancreatic cancer cells through inhibiting TFPI-2.

Pancreatic cancer (PC) is one of the most fatal cancers with a very poor prognosis. Here, we found that N6-methyladenosine (m6A) RNA demethylase fat mass and obesity-related protein (FTO) promote the growth, migration and invasion of PC. FTO expression level is increased in human PC and is associated with poor prognosis of PC patients. Knockdown of FTO increases m6A methylation of TFPI-2 mRNA in PC cells, thereby increasing mRNA stability via the m6A reader YTHDF1, resulting in up-regulation of TFPI-2 expression, and inhibits PC proliferation, colony formation, sphere formation, migration and invasion in vitro, as well as tumour growth in vivo. Rescue assay further confirms that FTO facilitates cancer progression by reducing the expression of TFPI-2. Mechanistically, FTO promotes the progression of PC at least partially through reducing m6A/YTHDF1 mediated TFPI-2 mRNA stability. Our findings reveal that FTO, as an m6A demethylase, plays a critical role in promoting PC growth, migration and invasion, suggesting that FTO may be a potential therapeutic target for treating PC.

Tumorigenic and immunological roles of Heat shock protein A2 in pancreatic cancer: a bioinformatics analysis

SUMMARY OBJECTIVE: Heat shock protein A2 has been reported to be tightly associated with tumorigenesis and tumor progression. This study aimed to determine the oncogenic and immunological roles of Heat shock protein A2 in pancreatic cancer by bioinformatics. METHODS: Expression of Heat shock protein A2 in tumorous and normal specimens of pancreatic cancer was analyzed using the Cancer Genome Atlas and the Cancer Genome Atlas + Genotype-Tissue Expression data sets, respectively. Relationships of Heat shock protein A2 expression with immune infiltrates in pancreatic cancer were assessed. Heat shock protein A2-associated coexpressed genes in pancreatic cancer were obtained, followed by the implementation of enrichment analysis. RESULTS: The data demonstrated that Heat shock protein A2 was significantly overexpressed in tumorous samples compared with normal samples. Heat shock protein A2 expression was remarkably positively interrelated with CD8+ T cell, neutrophil, dendritic cell, and macrophage, but not with CD4+ T and B cells. Heat shock protein A2 expression was markedly positively relevant to both cancer-associated fibroblast and endothelial cell. Enrichment data revealed that Heat shock protein A2 was intimately involved in the tumorigenesis and progression of pancreatic cancer. CONCLUSION: Heat shock protein A2 is upregulated in pancreatic cancer and is closely associated with tumor immunity and aggressive progression.

Upregulated HSPA2 predicts early relapse of pancreatic cancer after surgery.

BACKGROUND: Heat shock protein A2 (HSPA2) is known to relate to the pathogenesis and progress of cancer. This study aimed to investigate the connection between HSPA2 and early postsurgical relapse of pancreatic cancer (PC). METHODS: Expression of HSPA2 in 85 pairs of cancerous and matched noncancerous samples was determined by immunostaining method. The relationship between HSPA2 expression and early postsurgical recurrence was assessed using logistic regression. The performance and potential application of HSPA2 expression to predict early postsurgical recurrence was evaluated by receiver operating characteristic (ROC) curve analysis and decision curve analysis (DCA). RESULTS: HSPA2 expression in tumor specimens was markedly elevated compared with non-tumor specimens. Logistic regression analysis indicated that HSPA2 upregulation was an independent risk marker for early postsurgical recurrence of PC. ROC curve analysis and DCA demonstrated that both the area under the curve (AUC) and the net benefit of HSPA2 expression were higher than those of other clinicopathologic features in predicting early postsurgical relapse of PC. The combination of HSPA2 expression with other malignant clinicopathologic characteristics had greater AUC and net benefit relative to them alone in predicting early postsurgical recurrence. CONCLUSIONS: Upregulated HSPA2 independently predicts early postsurgical recurrence of PC and has superior predictive performance and potential application value when combined with malignant clinicopathologic features. Our findings reveal that HSPA2 is a promising predictor for early postoperative relapse of PC.

Four potential microRNAs affect the progression of pancreatic ductal adenocarcinoma by targeting MET via the PI3K/AKT signaling pathway.

Pancreatic ductal adenocarcinoma (PDAC) is the most common tumor subtype of pancreatic cancer, which exhibits poor patient prognosis due to the lack of effective biomarkers in the diagnosis and treatment. The present study aimed to identify the potential biomarkers of PDAC carcinogenesis and progression using three microarray datasets, GSE15471, GSE16515 and GSE28735, which were downloaded from the Gene Expression Omnibus database. The datasets were analyzed to screen out differentially expressed genes (DEGs) in PDAC tissues and adjacent normal tissues. A total of 143 DEGs were identified, including 132 upregulated genes and 11 downregulated genes. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes functional and signaling pathway enrichment analyses were performed on the DEGs, and the Search Tool for the Retrieval of Interacting Genes/Proteins database was used to construct a protein-protein interaction network. The main functions of DEGs include extracellular matrix degradation, and regulation of matrix metalloproteinase activity and the PI3K-Akt signaling pathway. The five hub genes were subsequently screened using Cytoscape software, and survival analysis demonstrated that abnormal expression levels of the hub genes was associated with poor disease-free survival and overall survival. Biological experiments were performed to confirm whether mesenchymal-to-epithelial transition (MET) factors promote the proliferation, migration and invasion of PDAC cells via the PI3K/AKT signaling pathway. In addition, six MET-targeted microRNAs (miRNAs) were identified, four of which had conserved binding sites with MET. Based on the signaling pathway enrichment analysis of these miRNAs, it is suggested that they can affect the progression of PDAC by targeting MET via the PI3K/AKT signaling pathway. In conclusion, the hub genes and miRNAs that were identified in the present study contribute to the molecular mechanisms of PDAC carcinogenesis and progression. They also provide candidate biomarkers for early diagnosis and treatment of patients with PDAC.

Panax notoginseng Saponins Promote Cell Death and Chemosensitivity in Pancreatic Cancer through the Apoptosis and Autophagy Pathways.

BACKGROUND: Panax notoginseng Saponins (PNS) is used as a traditional Chinese medicine for ischemic stroke and cardiovascular disease; it has been proven to possess anticancer activity recently. OBJECTIVE: In this study, we aimed to explore the curative anticancer effect and potential mechanisms of PNS in pancreatic cancer cells. METHODS: Pancreatic cancer Miapaca2 and PANC-1 cells were treated with PNS and Gemcitabine (Gem), respectively. Then the cell viability was assessed by CCK-8 assay, cell proliferation was tested by colony formation assay and EdU cell proliferation assay, cell migration and invasiveness were tested by wound healing assay and transwell assay, respectively, and cell apoptosis was detected by flow cytometry. Finally, we detected the expression levels of proteins related to migration, apoptosis and autophagy through Western blotting. RESULTS: PNS not only inhibited the proliferation, migration, invasion and autophagy of Miapaca2 and PANC-1 cells, but also induced apoptosis and promoted chemosensitivity of pancreatic cancer cells to Gem. CONCLUSION: PNS may exhibit cytotoxicity and increase chemosensitivity of pancreatic cancer cells to Gem by inhibiting autophagy and inducing apoptosis, providing a new strategy and potential treatment option for pancreatic cancer.

MicroRNA-23a acts as an oncogene in pancreatic carcinoma by targeting TFPI-2.

Pancreatic carcinoma (PC) is a rapidly progressive, fatal malignant tumor with the poorest prognosis among all major carcinoma types. MicroRNAs (miRNAs/miRs) have been indicated to be key post-transcriptional regulatory factors, which are involved in cancer development. The present study was designed to investigate the effect of miR-23a on PC cell proliferation, metastasis and apoptosis. The expression of miR-23a was detected in a normal pancreatic ductal epithelial cell line and three PC cell lines, and miR-23a inhibitor or mimics were transfected into the Panc-1 and MiaPaCa2 PC cells. The association between miR-23a and tissue factor pathway inhibitor (TFPI)-2 was examined using a luciferase reporter assay. MTT and flow cytometry assays were used to assess cell viability and apoptosis, respectively. Furthermore, wound-healing, Transwell and Matrigel assays were used to evaluate cell migration and invasion abilities, and the protein expression level of TFPI-2 was determined using western blot analysis. The results of the present study revealed that miR-23a was upregulated in PC cells. Furthermore, TFPI-2 was identified as a downstream target of miR-23a, and TFPI-2 expression was found to be increased following miR-23a knockdown. In addition, functional assays revealed that downregulation of miR-23a decreased PC cell proliferation, migration and invasiveness and promoted cell apoptosis, while miR-23a overexpression exerted the opposite effects. Furthermore, TFPI-2 knockdown rescued the biological effects on PC cells, which were induced by miR-23a knockdown. The results of the present study indicated that miR-23a negatively modulated TFPI-2 expression in vitro and enhanced the malignant phenotypes of PC cells. Therefore, miR-23a may be a potential marker and/or target for the diagnosis and treatment of PC.

Circulating exosomal microRNAs as novel potential detection biomarkers in pancreatic cancer.

Circulating exosomal microRNAs (ex-miRNAs) are reflective of the characteristics of the tumor and are valuable biomarkers in different types of tumor. In addition, miRNAs serve important roles in tumor progression and metastasis. The present study aimed to investigate the circulating ex-miRNA-21 and miRNA-210 as novel biomarkers for patients with pancreatic cancer (PC). For this purpose, serum ex-miRNAs were extracted from the serum of patients with PC (n=30) and chronic pancreatitis (CP) (n=10) using an RNA isolation kit. For exosome identification in serum, transmission electron micrographs were used to determine crystalline structure, western blotting was used to identify exosomal markers, and NanoSight was used for nanoparticle characterization. The relative expression levels of ex-miRNAs were quantified using quantitative PCR and compared between patients with PC and CP. The expression levels of both ex-miRNA-21 and miRNA-210 were significantly higher in patients with PC compared with patients with CP (both P<0.001). However, no significant difference in the relative serum levels of free miR-21 and miR-210 was observed between the 2 groups of patients (both P>0.05). ex-miRNA-21 and miRNA-210 were associated with tumor stage, as well as other factors. The diagnostic potential of ex-miRNA-21 and miRNA-210 levels was 83 and 85%, respectively. In addition, when ex-miRNA and serum carbohydrate antigen 19-9 expression levels were combined, the accuracy increased to 90%. The present study identified that serum ex-miRNAs, miRNA-21 and miRNA-210 may be of value as potential biomarkers and therapeutic targets for the diagnosis and treatment of PC.

Atypical presentations of coronavirus disease 2019 in a patient with acute obstructive suppurative cholangitis.

During the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) outbreak in Wuhan, China, we experienced a case of SARS-CoV-2 infection with atypical presentations in a patient with acute obstructive suppurative cholangitis (AOSC), who was initially admitted with jaundice and fever. The patient had no other typical symptoms of COVID-19 such as cough, dyspnea, nausea, vomiting, abdominal pain and diarrhea except for fever, but her epidemiological history was clear. COVID-19 was finally confirmed by repeated viral nucleic acid testing, but her repetitive lungs CT imaging findings had been atypical. After endoscopic-related operations and antiviral treatment, the patient was subsequently recovered and discharged. This particular case is being reported to provide a reference and guidance for the diagnosis and management of COVID-19 in AOSC.