Natural products in digestive tract tumors metabolism: Functional and application prospects.

Digestive tract diseases are presently the hotspot of clinical diagnosis and treatment, and the incidence of digestive tract tumor is increasing annually. Surgery remains the main therapeutic schedule for digestive tract tumor. Though benefits were brought by neoadjuvant chemotherapy, a part of patients lose the chance of surgery because of late detection or inappropriate intervention. Therefore, the treatment of inoperable patients has become an urgent need. At the same time, tumor metabolism is an extremely complex and diverse process. Natural products are confirmed effective to inhibit the development of tumors in vitro and in vitro. There are many kinds of natural products and their functions remain not clear. However, some natural products such as polyphenols have been proven to have definite anti-cancer effects, and some terpenoids have definite anti-inflammatory, anti-ulcer, anti-tumor, and other effects. Therefore, the anti-tumor characteristics of natural products should arouse our high attention. Although there are many obstacles to study the activities of natural products in tumor, including the difficulty in detection or distinguishing each component due to their low levels in tumor tissue, etc., the emergence of highly sensitive and locatable spatial metabolomics make the research and application of natural products a big step forward. In this review, natural products such as phenols, terpenoids and biotinoids were summarized to further discuss the development and therapeutic properties of natural metabolites on digestive tract tumors.

Infectious Complications in Severe Acute Pancreatitis: Pathogens, Drug Resistance, and Status of Nosocomial Infection in a University-Affiliated Teaching Hospital.

BACKGROUND: Secondary infection is an important factor affecting mortality and quality of life in patients with severe acute pancreatitis. The characteristics of secondary infection, which are well known to clinicians, need to be re-examined in detail, and their understanding among clinicians needs to be updated accordingly. AIM: This study aims to investigate the characteristics and drug resistance of pathogens causing severe acute pancreatitis (SAP) secondary infection, to objectively present infection situation, and to provide reference for improved clinical management. METHODS: A retrospective analysis was performed on 55 consecutive patients with SAP who developed secondary infection with an accurate evidence of bacterial/fungal culture from 2016 to 2018. The statistics included the spectrum and distribution of pathogens, the drug resistance of main pathogens, and associations between multiple infectious parameters and mortality. RESULTS: A total of 181 strains of pathogens were isolated from (peri)pancreas; bloodstream; and respiratory, urinary, and biliary systems in 55 patients. The strains included 98 g-negative bacteria, 58 g-positive bacteria, and 25 fungi. Bloodstream infection (36.5%) was the most frequent infectious complication, followed by (peri)pancreatic infection (32.0%). Acinetobacter baumannii, Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, and Stenotrophomonas maltophilia were predominant among gram-negative bacteria. Gram-positive bacterial infections were mainly caused by Enterococcus faecium and Staphylococcus spp. Fungal infections were predominantly caused by Candida spp. The drug resistance of pathogens causing SAP secondary infection was generally higher than the surveillance level. Patients in the death group were older (55 ± 13 years vs. 46 ± 14 years; p = 0.039) and had longer intensive care unit (ICU) stay (14 vs. 8; p = 0.026) than those in the survival group. A. baumannii infection (68.4% vs. 33%; p = 0.013), number of pathogens ≥ 4 (10 vs. 6; p = 0.005), pancreatic infection (14 vs. 15, p = 0.024), and urinary infection (8 vs. 5; p = 0.019) were significantly associated with mortality. CONCLUSION: Gram-negative bacteria are the main pathogens causing SAP secondary infection, in which nosocomial infections play a major role. The drug resistance profile of gram-negative bacteria is seriously threatening, and the commonly used antibiotics in SAP are gradually losing their effectiveness. Much attention should be paid to the rational use of antibiotics, and strategies should be established for infection prevention in SAP.

Inactivation of ATF-2 enhances epithelial-mesenchymal transition and gemcitabine sensitivity in human pancreatic cancer cells.

OBJECTIVE: This work aimed to study the activating transcription factor 2 or AMP-dependent transcription factor-2 (ATF-2) inhibition mediated gemcitabine sensitivity in human pancreatic cancer cells. METHODS: The protein and messenger RNA expressions of ATF-2 in 42 pancreatic cancer tissues and adjacent nontumorous tissues were detected. Kaplan-Meier survival analysis was performed based on the expression level of ATF-2 protein in tumor tissues. Then the pancreatic cancer cells were transduced with ATF-2-expressing lentivirus and small interfering RNAs (siRNAs) to investigate the effect of ATF-2 on pancreatic cancer cell invasion, epithelium to mesenchyme transition, apoptosis, and gemcitabine sensitivity. RESULTS: The expression of phosphorylated (p)-ATF-2 protein was upregulated in pancreatic cancer tissues compared with adjacent nontumorous tissues. Patients with relative higher p-ATF-2 level showed significantly lower survival time. Then we found that the transfection ATF-2 siRNA into BxPC3 cells inhibited cell proliferation, invasion, and epithelium to mesenchyme transition, but enhanced cell apoptosis. These changes could be enhanced by the additional administration of gemcitabine. In addition, we confirmed that the overexpression of ATF-2 in Panc-1 cells promoted cell invasion and epithelium to mesenchyme transition. CONCLUSION: We concluded that inhibition-promoted ATF-2 expression was responsible for epithelium to mesenchyme transition and invasion of pancreatic cancer cells, while the inhibition of ATF-2 confers to gemcitabine sensitivity in human pancreatic cancer cells in vitro.

Silencing of ATF2 inhibits growth of pancreatic cancer cells and enhances sensitivity to chemotherapy.

Pancreatic cancer is one of the leading causes of cancer-related death worldwide. Activating transcription factor 2 (ATF2) is a multifunctional transcription factor, and is implicated in tumor progress, yet its role in pancreatic cancer remains unclear. In the present study, the level of ATF2 in pancreatic cancer tissues and the adjacent non-tumorous tissues was detected by quantitative real-time PCR and Western blot. The roles of ATF2 in the proliferation, cell cycle, and apoptosis of pancreatic cancer cells were investigated through ATF2 silencing, and the effect of ATF2 shRNA on the sensitivity of pancreatic cancer cells to gemcitabine, an anti-tumor drug, was explored. The results of our study showed that the ATF2 level in the pancreatic cancer tissues was higher than that in the adjacent non-tumorous tissues. Silencing of ATF2 was found to inhibit proliferation, arrest cell cycle at G1 phase and induce apoptosis in pancreatic cancer cells. Moreover, ATF2 silencing enhanced gemcitabine-induced growth-inhibition and apoptosis-induction effects in pancreatic cancer cells. In summary, silencing of ATF2 inhibited the growth of pancreatic cancer cells and enhanced the anti-tumor effects of gemcitabine, suggesting that ATF2 plays a pro-survival role in pancreatic cancer. Our results also propose that a high level of ATF2 may serve as a potential biomarker of pancreatic cancer, and that ATF2 may become a potential target for anti-tumor therapy.

Raman spectroscopy combined with deep learning for rapid detection of melanoma at the single cell level.

Melanoma is an aggressive and metastatic skin cancer caused by genetic mutations in melanocytes, and its incidence is increasing year by year. Understanding the gene mutation information of melanoma cases is very important for its precise treatment. The current diagnostic methods for melanoma include radiological, pharmacological, histological, cytological and molecular techniques, but the gold standard for diagnosis is still pathological biopsy, which is time consuming and destructive. Raman spectroscopy is a rapid, sensitive and nondestructive detection method. In this study, a total of 20,000 Surface-enhanced Raman scattering (SERS) spectra of melanocytes and melanoma cells were collected using a positively charged gold nanoparticles planar solid SERS substrate, and a classification network system based on convolutional neural networks (CNN) was constructed to achieve the classification of melanocytes and melanoma cells, wild-type and mutant melanoma cells and their drug resistance. Among them, the classification accuracy of melanocytes and melanoma cells was over 98%. Raman spectral differences between melanocytes and melanoma cells were analyzed and compared, and the response of cells to antitumor drugs were also evaluated. The results showed that Raman spectroscopy provided a basis for the medication of melanoma, and SERS spectra combined with CNN classification model realized classification of melanoma, which is of great significance for rapid diagnosis and identification of melanoma.

Combining fiber optical tweezers and Raman spectroscopy for rapid identification of melanoma.

Cutaneous melanoma is a skin tumor with a high degree of malignancy and fatality rate, the incidence of which has increased in recent years. Therefore, a rapid and sensitive diagnostic technique of melanoma cells is urgently needed. In this paper, we present a new approach using fiber optical tweezers to manipulate melanoma cells to measure their Raman spectra. Then, combined with Principal Component Analysis and Support Vector Machines (PCA-SVM) classification model, to achieve the classification of common mutant, wild-type and drug-resistant melanoma cells. A total of 150 Raman spectra of 30 cells were collected from mutant, wild-type and drug-resistant melanoma cell lines, and the classification accuracy was 92%, 94%, 97.5%, respectively. These results suggest that the study of tumor cells based on fiber optical tweezers and Raman spectroscopy is a promising method for early and rapid identification and diagnosis of tumor cells.

Enhancing interactions between cells and hierarchical micro/nanostructured TiO2films for efficient capture of circulating tumor cells.

Micro/nano hierarchical substrates with different micropillar spacings were designed and prepared for capture of tumor cells. The cell capture efficiency of hierarchical substrates with low-density micropillar arrays was similar to that of nanostructured substrate. Increasing the density of micopillars could significantly improve the capture efficiency. The maximum capture efficiency was achieved on the hierarchical substrate with micropillar spacings of 15µm, but further reducing the micropillar spacings did not increase the cell capture efficiency. It was also found that hierarchical substrates with appropriate spacing of micropillars appeared more favorable for cell attachment and spreading, and thus enhancing the cell-material interaction. These results suggested that optimizing the micropillar arrays, such as the spacing between adjacent micropillars, could give full play to the synergistic effect of hierarchical hybrid micro/nanostructures in the interaction with cells. This study may provide promising guidance to design and optimize micro/nano hierarchical structures of biointerfaces for biomedical application.

A rare case of duodenum perforation after biliary stenting under endoscopic retrograde cholangiopancreatography: a case report.

Duodenal injury under endoscopic retrograde cholangiopancreatography (ERCP) is extremely rare. This study describes a case of duodenum perforation after biliary stenting under ERCP for the first time. A 67-year-old female patient was transferred to the emergency department of First Hospital of China Medical University after experiencing whole abdominal pain for 6 hours. The patient had received a biliary stent placement under ERCP at an outer hospital 6 days previously due to duodenal papillary occupy. During the operation, a small perforation caused by a biliary stent was found at the lateral side of the duodenum, but no biliary stent was found. Duodenal juice was flowing out from the perforation, Then, the perforation was opened obliquely, and an 8-cm portion of the biliary stent was removed. Gastrostomy, jejunostomy, and choledochotomy T-tube drainage procedures were subsequently performed. The patient recovered well and was discharged with the T-tube and the jejunal nutrition tube after 20 days. Four types of perforation under ERCP have been reported in previous literature, and this case report documents a rare complication from biliary stenting under ERCP. This case is different from the previous four types and can be called type V, which give general endoscopic doctors a serious warning.

HIF1/2α mediates hypoxia-induced LDHA expression in human pancreatic cancer cells.

Glycolysis is a typical conduit for energy metabolism in pancreatic cancer (PC) due to the hypoxic microenviroment. Lactate dehydrogenase A (LDHA) catalyzes the conversion of pyruvate to lactate and is considered to be a key checkpoint of anaerobic glycolysis. The aim of the present study was to explore the mechanism of interactions between hypoxia, HIF-1/2α and LDHA, and the function of LDHA on PC cells by analyzing 244 PC and paratumor specimens. It was found that LDHA was over-expressed and related to tumor stages. The result of in vitro study demonstrated that hypoxia induced LDHA expression. To explore the relationship between HIF and LDHA, chromatin immunoprecipitation assay and luciferase assay were performed. The result showed that HIF-1/2α bound to LDHA at 89bp under the hypoxic condition. Furthermore, knockdown of endogenous HIF-1α and HIF-2α decreased the LDHA expression even in the hypoxic condition, which was accompanied with a significant decrease in lactate production and glucose utilization (p < 0.01). Immunofluorescence in the 244 specimens showed that HIF-1/2α was over-expressed and associated with LDHA over-expression (p < 0.0001). Forced expression of LDHA promoted the growth and migration of PC cells, while knocking down the expression of LDHA inhibited the cell growth and migration markedly. In summary, the present study proved that HIF1/2α could activate LDHA expression in human PC cells, and high expression of LDHA promoted the growth and migration of PC cells.

Identification of disease-associated pathways in pancreatic cancer by integrating genome-wide association study and gene expression data.

In order to additionally understand the pathogenesis of pancreatic cancer (PC), the present study conducted pathway analysis based on genome-wide association study (GWAS) and gene expression data to predict genes that are associated with PC. GWAS data (accession no., pha002874.1) were downloaded from National Center for Biotechnology Information (NCBI) database of Genotypes and Phenotypes, which included data concerning 1,896 patients with PC and 1,939 control individuals. Gene expression data [accession no., GSE23952; human pancreatic carcinoma Panc-1 transforming growth factor-ß (TGF-ß) treatment assay] were downloaded from NCBI Gene Expression Omnibus. Gene set enrichment analysis was used to identify significant pathways in the GWAS or gene expression profiles. Meta-analysis was performed based on pathway analysis of the two data sources. In total, 58 and 280 pathways were identified to be significant in the GWAS and gene expression data, respectively, with 7 pathways significant in both the data profiles. Hsa 04350 TGF-ß signaling pathway had the smallest meta P-value. Other significant pathways in the two data sources were negative regulation of DNA-dependent transcription, the nucleolus, negative regulation of RNA metabolic process, the cellular defense response, exocytosis and galactosyltransferase activity. By constructing the gene-pathway network, 5 pathways were closely associated, apart from exocytosis and galactosyltransferase activity pathways. Among the 7 pathways, 11 key genes (2.9% out of a total of 380 genes) from the GWAS data and 43 genes (10.5% out of a total of 409 genes) from the gene expression data were differentially expressed. Only Abelson murine leukemia viral oncogene homolog 1 from the nucleolus pathway was significantly expressed in by both data sources. Overall, the results of the present analysis provide possible factors for the occurrence of PC, and the identification of the pathways and genes associated with PC provides valuable data for investigating the pathogenesis of PC in future studies.

siRNA-Mediated SBF2 Silencing May Inhibit Pancreatic Cancer Cells via Attenuation of the TGF-ß Signaling Pathway.

OBJECTIVE: To investigate the effects of small-interfering RNA (siRNA)-mediated silencing of SET binding factor 2 (SBF2) on pancreatic cancer cells and its underlying molecular mechanisms. METHODS: Five siRNAs, namely, siRNA-1, siRNA-2, siRNA-3, siRNA-4, and siRNA-5, were designed to silence SBF2 in pancreatic cancer PANC-1 cells. The relative expression levels of SBF2 after siRNA-mediated SBF2 silencing were detected by real-time polymerase chain reaction (RT-PCR). The inhibition and apoptosis of cells were detected by methyl thiazolyl tetrazolium and flow cytometry, respectively. The protein concentrations of SBF2, SMAD-2, phosphorylated-SMAD-2 (p-SMAD-2), SMAD-3, p-SMAD-3, and SMAD-7 were also measured via Western blot. RESULTS: The relative expression levels of SBF2 in the siRNA-mediated SBF2-silenced groups decreased significantly (P < .05), and the proliferation of PANC-1 cells was significantly inhibited (P < .01) after SBF2 silencing using the 5 siRNAs. The relative expression level of SBF2 was the lowest (0.52 ± 0.05) and the cell inhibition rate was the highest (36.7 ± 4.0%) in the SBF2-silenced PANC-1 cells using siRNA-3 compared to the 5 siRNA-mediated SBF2-silenced groups. The cell apoptosis rate in the siRNA-3 transfection group was significantly higher than that in the control group (P < .05). The concentrations of p-SMAD-2 and p-SMAD-3 were reduced, while the concentrations of SMAD-2, SMAD-3, and SMAD-7 were increased in the siRNA-3-mediated SBF2-silenced PANC-1 cells. CONCLUSION: SiRNA-mediated SBF2 silencing could significantly inhibit the proliferation and promote the apoptosis of pancreatic cancer cells possibly via attenuation of transforming growth factor ß/SMAD signaling pathway. And SBF2 silencing can be a potential approach for treatment of pancreatic cancer.

Gene expression profile analysis of pancreatic cancer based on microarray data.

The present study identified differentially­expressed genes (DEGs) between pancreatic cancer (PC) tissues and normal tissues, and assessed genetic factors associated with the pathogenesis of PC. The mRNA expression microarray dataset, GSE16515, containing 52 samples, including 16 paired tumor and normal tissue samples, and 20 tumor samples, was downloaded from Gene Expression Omnibus. Raw data were normalized and DEGs were identified. Subsequently, clustering was performed, protein­protein interaction networks were drawn, and functional and pathway enrichment analyses of the DEGs were performed. Copy number variations of DEGs were also identified. A total of 1,765 DEGs between PC and normal tissues were identified, including 1,312 upregulated and 453 downregulated DEGs. Upregulated DEGs were associated with the regulation of nucleocytoplasmic and intracellular transport, whereas downregulated DEGs were associated with the response to organic substances and hormone stimulus. The pancreatic cancer pathway was connected to three DEGs, namely transforming growth factor ß1 (TGFB1), TGFß receptor 1 (TGFBR1) and epidermal growth factor (EGF), which had 2, 3 and 5 CNVs, respectively. These results indicated the important roles of TGFB1, TGFBR1 and EGF in the pathogenesis of PC. These genes may be potential therapeutic targets for the treatment of PC.

Screening for genes and subnetworks associated with pancreatic cancer based on the gene expression profile.

The present study aimed to screen for potential genes and subnetworks associated with pancreatic cancer (PC) using the gene expression profile. The expression profile GSE 16515 was downloaded from the Gene Expression Omnibus database, which included 36 PC tissue samples and 16 normal samples. Limma package in R language was used to screen differentially expressed genes (DEGs), which were grouped as up­ and downregulated genes. Then, PFSNet was applied to perform subnetwork analysis for all the DEGs. Moreover, Gene Ontology (GO) and REACTOME pathway enrichment analysis of up­ and downregulated genes was performed, followed by protein­protein interaction (PPI) network construction using Search Tool for the Retrieval of Interacting Genes Search Tool for the Retrieval of Interacting Genes. In total, 1,989 DEGs including 1,461 up­ and 528 downregulated genes were screened out. Subnetworks including pancreatic cancer in PC tissue samples and intercellular adhesion in normal samples were identified, respectively. A total of 8 significant REACTOME pathways for upregulated DEGs, such as hemostasis and cell cycle, mitotic were identified. Moreover, 4 significant REACTOME pathways for downregulated DEGs, including regulation of ß­cell development and transmembrane transport of small molecules were screened out. Additionally, DEGs with high connectivity degrees, such as CCNA2 (cyclin A2) and PBK (PDZ binding kinase), of the module in the protein­protein interaction network were mainly enriched with cell­division cycle. CCNA2 and PBK of the module and their relative pathway cell­division cycle, and two subnetworks (pancreatic cancer and intercellular adhesion subnetworks) may be pivotal for further understanding of the molecular mechanism of PC.

Preliminary assessment of two non-destructive instrumental techniques for quality evaluation of Lobelia chinensis Lour.

Two non-destructive instrumental methods, infrared spectroscopy (IR) and X-ray diffraction (XRD), were studied for quality evaluation of Lobelia chinensis Lour. (L. chinensis). We obtained the IR spectra and XRD patterns of L. chinensis collected from different sources. The similarity of samples was analyzed by calculating the cosine coefficient. The cosine values were in the range of 0.83-0.90, indicating that the main components of L. chinensis samples are similar. Sample L1 and L6 showed a slightly lower similarity than that of L2, L3, L4, L5 detected by the two methods, which revealed that IR and XRD methods exhibited analogous detection ability for quality evaluation of L. chinensis. The two methods could be highly recommended as simple and rapid detection means for quality evaluation of L. chinensis.