Annotation of Dipeptides and Tripeptides Derivatized via Dansylation Based on Liquid Chromatography-Mass Spectrometry and Iterative Quantitative Structure Retention Relationship.

Small peptides such as dipeptides and tripeptides show various biological activities in organisms. However, methods for identifying dipeptides/tripeptides from complex biological samples are lacking. Here, an annotation strategy involving the derivatization of dipeptides and tripeptides via dansylation was suggested based on liquid chromatography-mass spectrometry (LC-MS) and iterative quantitative structure retention relationship (QSRR) to choose dipeptides/tripeptides by using a small number of standards. First, the LC-autoMS/MS method and initial QSRR model were built based on 25 selected grid-dipeptides and 18 test-dipeptides. To achieve high-coverage detection, dipeptide/tripeptide pools containing abundant dipeptides/tripeptides were then obtained from four dansylated biological samples including serum, tissue, feces, and soybean paste by using the parameter-optimized LC-autoMS/MS method. The QSRR model was further optimized through an iterative train-by-pick strategy. Based on the specific fragments and tR tolerances, 198 dipeptides and 149 tripeptides were annotated. The dipeptides at lower annotation levels were verified by using authentic standards and grid-correlation analysis. Finally, variation in serum dipeptides/tripeptides of three different liver diseases including hepatitis B infection, liver cirrhosis, and hepatocellular carcinoma was characterized. Dipeptides with N-prolinyl, C-proline, N-glutamyl, and N-valinyl generally increased with disease severity. In conclusion, this study provides an efficient strategy for annotating dipeptides/tripeptides from complex samples.

Naphthenic Acids Removal from Model Transformer Oil by Diethylamine Modified Resins.

Resins have enormous potential in the removal of naphthenic acids (NAs) from transformer oil due to their rich porosity and high mechanical and diversified functionality, whereas their poor adsorption capacity limits application. In this work, the polystyrene-diethylamine resin (PS-DEA-x) was prepared by grafting diethylamine (DEA) onto chloromethylated polystyrene (PS-Cl) resin to efficiently adsorb cyclopentane carboxylic acid from transformer oil for the first time. The characterization analysis results indicated that amine contents were significantly enhanced with the increase in DEA. Particularly, resin with a molar ratio of 1:5 depending on chloromethyl to DEA (PS-DEA-5) exhibited the highest amine contents and efficient adsorption of cyclopentane carboxylic acid (static adsorption capacity up to 110.0 mg/g), which was about 5 times higher than that of the pristine PS-Cl. The thermodynamic and kinetic studies showed that the adsorption behaviors could be well fitted to the Langmuir isotherm equation and pseudo-second-order rate equation. Moreover, it was found that 1 g of the PS-DEA-5 can decontaminate about 760 mL transformer oil to meet reuse standards by a continuous stream, indicating its potential application in industry.

Screening of idiopathic epiretinal membrane using fundus images combined with blood oxygen saturation and vascular morphological features.

PURPOSE: To achieve an accurate diagnosis of idiopathic epiretinal membrane (iERM) through analyzing retinal blood vessel oxygen saturation (SO2) and vascular morphological features in fundus images. METHODS: Dual-modal fundus camera was used to obtain color fundus image, 570-nm, and 610-nm images. As iERM affects the macular area, a macular-centered semicircle area as region of interest (MROI) was selected and analyzed SO2 and vascular morphologies in it. Eventually, random forest (RF) and support vector machine (SVM) were as classifiers to diagnose iERM patients. RESULTS: The arterial and venous SO2 levels of the iERM group were significantly higher than that of the control group. There were significant differences in the vessel density and fractal dimension on the artery for vascular morphology, while the tortuosity had a significant difference in the vein. By feeding the SO2 and the vascular morphological features into classifiers, an accuracy of over 82% was obtained, which is significantly better than the two separate inputs for classification. CONCLUSION: Significant differences in SO2 and vascular morphologies between control and iERM groups confirmed that the occurrence of iERM may affect blood supply and vascular structures. Benefiting from the dual-modal fundus camera and machine learning models, accurate judgments can be made on fundus images. Extensive experiments proved the importance of blood vessel SO2 and vascular morphologies for diagnosis, which is of great significance for clinical screening.

Identification and Validation of TRIM25 as a Glucose Metabolism Regulator in Prostate Cancer.

Prostate cancer (PCa) malignant progression is accompanied with the reprogramming of glucose metabolism. However, the genes involved in the regulation of glucose metabolism in PCa are not fully understood. Here, we propose a new method, DMRG, which constructs a weighted differential network (W-K-DN) to define the important metabolism-related genes. Based on biological knowledge and prostate cancer transcriptome data, a tripartite motif-containing 25 (TRIM25) was defined using DMRG; TRIM25 was involved in the regulation of glucose metabolism, which was verified by overexpressing or knocking down TRIM25 in PCa cell lines. Differential expression analysis of TCA cycle enzymes revealed that TRIM25 regulated isocitrate dehydrogenase 1 (IDH1) and fumarate hydratase (FH) expression. Moreover, a protein-RNA interaction network of TRIM25 revealed that TRIM25 interacted with RNA-binding proteins, including DExH-box helicase 9 and DEAD-box helicase 5, to play a role in regulating the RNA processing of metabolic enzymes, including IDH1 and FH. Furthermore, TRIM25 expression level was found to be positively correlated with Gleason scores in PCa patient tissues. In conclusion, this study provides a new method to define genes influencing tumor progression, and sheds light on the role of the defined TRIM25 in regulating glucose metabolism and promoting PCa malignancy.

Lipid Profiling of 20 Mammalian Cells by Capillary Microsampling Combined with High-Resolution Spectral Stitching Nanoelectrospray Ionization Direct-Infusion Mass Spectrometry.

Studies of cellular metabolism can provide profound insights into the underlying molecular mechanisms and metabolic function. To date, the majority of cellular metabolism studies based on chromatography-mass spectrometry (MS) require population cells to obtain informative metabolome. These methods are not only time-consuming but also not suitable for amount-limited cell samples such as circulating tumor cells, stem cells, and neurons. Therefore, it is extremely essential to develop analytical methods enabling to detect metabolome from tens of cells in a high-throughput and high-sensitivity way. In this work, a novel platform for rapid and sensitive detection of lipidome in 20 mammalian cells was proposed using capillary microsampling combined with high-resolution spectral stitching nanoelectrospray ionization direct-infusion MS. It can be used to collect cells rapidly and accurately via the capillary microprobe, extract lipids directly in a 96-well plate using a spray solvent, and detect more than 500 lipids covering 19 lipid subclasses within 3 min. This novel platform was successfully applied to study the lipid features of different cancer cell types and subtypes as well as target cells from tissue samples. This study provides a strategy for determining the lipid species with rich information in tens of cells and demonstrates great potential for clinical applications.

MARVELD1 interacting with catalase regulates reactive oxygen species metabolism and mediates the sensitivity to chemotherapeutic drugs in epithelial tumors of the reproductive system.

Previous investigations have found that MARVEL domain-containing 1 (MARVELD1) could inhibit tumor cell proliferation and enhance the sensitivity to chemotherapeutic drugs in hepatocellular carcinoma. Hence, it may be a valuable therapeutic target. In the study, we analyzed the responsive changes of MARVELD1 to 25 stress factors and expression of MARVELD1 in epithelial tumors of the reproductive system. We found that MARVELD1 was transferred to the cytoplasm and mitochondria under cell stress. And under cellular stress, the reactive oxygen species (ROS) levels decreased in MARVELD1 expressed cells while increased in the cells of MARVELD1-specific siRNA treatment. Meanwhile, MARVELD1 overexpression significantly promoted the inhibition of tumor cell proliferation under cellular stress via affecting ROS metabolism, not cell cycle. In xenograft tumor tissues with MARVELD1 expression, the tumor growth was inhibited and accompanied by the lower ROS levels. Furthermore, we identified that MARVELD1 could interact with catalase (CAT) to enhance latter activity and maintain stability. And the enhanced sensitivity to chemotherapeutic drugs clearly depended on the ability of MARVELD1 scavenge the ROS in carcinoma cells of the reproductive system. Our findings clearly explain that MARVELD1 may regulate tumor cell proliferation and sensitivity to chemotherapeutic drugs via reducing the exorbitant ROS. The mechanism was that MARVELD1 interacted with CAT to maintain latter stability, and then ensure continuous ROS scavenge.

The depletion of MARVELD1 leads to murine placenta accreta via integrin ß4-dependent trophoblast cell invasion.

The placenta is a remarkable organ, it serves as the interface between the mother and the fetus. Proper invasion of trophoblast cells is required for a successful pregnancy. Previous studies have found that the adhesion molecule integrin ß4 plays important roles during trophoblast cell invasion. Here, we found that the overall birth rate of the MARVELD1 knockout mouse is much lower than that of the wild-type mouse (p < 0.001). In E18.5 MARVELD1 knockout mice, we observed an over-invasion of trophoblast cells, and indeed, the pregnant mice had a partial placenta accreta phenotype. The HTR8/SVneo cell line was used as an in vitro model to elucidate the underlying mechanisms of MARVELD1-mediated trophoblast invasion. We detected a diminished expression of integrin ß4 upon the downregulation of MARVELD1 and enhanced migrate and invasive abilities of trophoblast cells both in vivo and in vitro. The integrin ß4 rescue assay also supported the results. In conclusion, this study found that MARVELD1 mediated the invasion of trophoblast cells via regulating the expression of integrin ß4 during placenta development.

Concentric Hybrid Nanoelectrospray Ionization-Atmospheric Pressure Chemical Ionization Source for High-Coverage Mass Spectrometry Analysis of Single-Cell Metabolomics.

High-coverage mass spectrometry analysis of single-cell metabolomics remains challenging due to the extremely low abundance and wide polarity of metabolites and ultra-small volume in single cells. Herein, a novel concentric hybrid ionization source, nanoelectrospray ionization-atmospheric pressure chemical ionization (nanoESI-APCI), is ingeniously designed to detect polar and nonpolar metabolites simultaneously in single cells. The source is constructed by inserting a pulled glass capillary coaxially into a glass tube that acts as a dielectric barrier layer. Benefitting from the integrated advantages of nanoESI and APCI, its limit of detection is improved by one order of magnitude to 10 pg mL-1. After the operational parameter optimization, 254 metabolites detected in nanoESI-APCI are tentatively identified from a single cell, and 82 more than those in nanoESI. The developed nanoESI-APCI is successively applied to study the metabolic heterogeneity of human hepatocellular carcinoma tissue microenvironment united with laser capture microdissection (LCM), the discrimination of cancer cell types and subtypes, the metabolic perturbations to glucose starvation in MCF7 cells and the metabolic regulation of cancer stem cells. These results demonstrated that the nanoESI-APCI not only opens a new avenue for high-coverage and high-sensitivity metabolomics analysis of single cell, but also facilitates spatially resolved metabolomics study coupled with LCM.

Defining disease-related modules based on weighted miRNA synergistic network.

MicroRNAs (miRNAs) play an important role in the biological process. Their expression and functional changes have been observed in most cancers. Meanwhile, there exists cooperative regulation among miRNAs which is important for studying the mechanisms of complex post-transcriptional regulations. Hence, studying miRNA synergy and identifying miRNA synergistic modules can help understand the development and progression of complex diseases, such as cancers. This work studies miRNA synergy and proposes a new method for defining disease-related modules (DDRM) by combining the knowledge databases and miRNA data. DDRM measures the miRNA synergy not only by the co-regulating target subset but also by the non-common target set to construct the weighted miRNA synergistic network (WMSN). The experiments on twelve the cancer genome atlas (TCGA) datasets showed that the important modules identified by DDRM can well distinguish the cancer samples from the normal samples, and DDRM performed better than the previous method in most cases. An external dataset of prostate cancer was applied to validate the module biomarkers determined by DDRM on the prostate cancer data of TCGA. The area under the receiver operating characteristic curve (AUC) value is 0.92 and the performance is superior. Hence, combining the miRNA synergy networks from the knowledge databases and the miRNA data can determine the important functional modules related to diseases, which is of great significance to the study of disease mechanism.

A novel nomogram based on body composition and nutritional indicators to predict the prognosis of patients with muscle-invasive bladder cancer undergoing radical cystectomy.

OBJECTIVE: To investigate the prognostic significance of body composition and nutritional indicators in patients undergoing radical cystectomy with muscle-invasive bladder cancer (MIBC) and to develop a novel nomogram that accurately predicts overall survival (OS). METHODS: From December 2010 to December 2020, we retrospectively collected clinical and pathological data from 373 MIBC patients who underwent radical cystectomy at our hospital. Preoperative computed tomography (CT) images were used to measure the skeletal muscle index (SMI), subcutaneous adipose index (SAI), visceral adipose index (VAI), skeletal muscle density (SMD), subcutaneous adipose density (SAD), visceral adipose density (VAD), and visceral adipose to subcutaneous adipose area ratio (VSR). The clinicopathological characteristics were evaluated using LASSO regression and multivariate Cox regression, and a nomogram was constructed to predict 1-, 3-, and 5-year overall survival. The concordance index (C-index), time-dependent receiver operating characteristic curves (t-ROC), calibration curve, and decision curve analysis (DCA) were used to assess the discriminative ability, calibration, and clinical practicality of the nomogram. RESULTS: Multivariate analyses demonstrated that pT stage, lymph node status, LVI, SMD, and prognostic nutritional index (PNI) are independent prognostic factors for OS. Additionally, a nomogram was created. The nomogram's C-index was 0.714 (95% CI: 0.695-0.733). The area under the t-ROC curve of 1-, 3-, and 5-year survival corresponding to the model was 0.726, 0.788, and 0.785, respectively. The calibration curve demonstrated excellent agreement between the predicted and observed outcomes. The DCA revealed that patients with MIBC could benefit from the nomogram. CONCLUSION: Based on body composition and nutritional indicators, we developed a novel nomogram with excellent predictive accuracy and reliability for predicting the prognosis of MIBC patients undergoing RC.

Metabolomics acts as a powerful tool for comprehensively evaluating vaccines approved under emergency: a CoronaVac retrospective study.

Introduction: To control the COVID-19 pandemic, great efforts have been made to realize herd immunity by vaccination since 2020. Unfortunately, most of the vaccines against COVID-19 were approved in emergency without a full-cycle and comprehensive evaluation process as recommended to the previous vaccines. Metabolome has a close tie with the phenotype and can sensitively reflect the responses to stimuli, rendering metabolomic analysis have the potential to appraise and monitor vaccine effects authentically. Methods: In this study, a retrospective study was carried out for 330 Chinese volunteers receiving recommended two-dose CoronaVac, a vaccine approved in emergency in 2020. Venous blood was sampled before and after vaccination at 5 separate time points for all the recipients. Routine clinical laboratory analysis, metabolomic and lipidomic analysis data were collected. Results and discussion: It was found that the serum antibody-positive rate of this population was around 81.82%. Most of the laboratory parameters were slightly perturbated within the relevant reference intervals after vaccination. The metabolomic and lipidomic analyses showed that the metabolic shift after inoculation was mainly in the glycolysis, tricarboxylic acid cycle, amino acid metabolism, urea cycle, as well as microbe-related metabolism (bile acid metabolism, tryptophan metabolism and phenylalanine metabolism). Time-course metabolome changes were found in parallel with the progress of immunity establishment and peripheral immune cell counting fluctuation, proving metabolomics analysis was an applicable solution to evaluate immune effects complementary to traditional antibody detection. Taurocholic acid, lysophosphatidylcholine 16:0 sn-1, glutamic acid, and phenylalanine were defined as valuable metabolite markers to indicate the establishment of immunity after vaccination. Integrated with the traditional laboratory analysis, this study provided a feasible metabolomics-based solution to relatively comprehensively evaluate vaccines approved under emergency.

Microplastic reorganization in urban river before and after rainfall.

Microplastics (MPs) present in non-negligible amounts in urban environments, where urban rivers serve as important transport channels for MPs. However, the footprint of MPs in urban rivers under the influence of natural and anthropogenic factors is poorly understood. This study investigated the MPs organization, stability and pollution risk before and after rainfall in the Qing River, Beijing. Rainfall potentially diluted the MPs abundance, attributed to opening of barrages and increase of flow velocity. The proportion of small-sized MPs (SMPs, 48-300 µm) decreased slightly, whereas that of normal-sized MPs (NMPs, 300-1000 µm) and large-sized MPs (LMPs, > 1000 µm) increased. However, SMPs dominantly presented in the Qing River before and after rainfall. Polyethylene terephthalate (PET), polypropylene (PP), polyethylene (PE), and polystyrene (PS) were main polymers observed in the Qing River. The proportions of PET and PS decreased, while PP and PE increased after rainfall. The main types of MPs introduced by stormwater were PP and PE. The elevated MP diversity integrated index after rain suggested that rainfall enriched the local sources of MPs. Rainfall reduced the stability and fragmentation of MPs owing to the introduction of large debris. NMPs and LMPs were susceptible to further fragmentation and downsizing, implying that MPs abundance in the Qing River tended to rise and SMPs might enriched. In addition, alteration of MPs fragmentation and stability reflected that the likely input source was wastewater treatment plant and atmospheric deposition before rainfall, whereas soil and road dust were possible sources after rainfall. The pollution risk assessment defined the MPs pollution risk of Qing River as low level and decreased after rainfall. This study demonstrated that rainfall substantially influences MPs organization in urban river and provided empirical support for MPs environmental behavior under influence of natural and anthropogenic factors.

At-line coupling of magnetic-nanoparticle-based extraction with gel isoelectric focusing for protein analysis.

Sample preparation is a crucial step for protein analysis. Functionalized magnetic nanoparticle (MNP)-based extraction has been developed to be a useful sample preparation technique for proteomic analysis. In this paper, we present a strategy for at-line coupling of MNP-based extraction (MNE) with gel isoelectric focusing (IEF). The key to the at-line combination is to use an anolyte or a catholyte as the desorbing agent. Thus, functionalized MNPs can be facilely at-line coupled with gel IEF, provided that the extraction/desorption process is pH-controlled. MNPs extracted with target proteins are added to the sample well, which can function as a natural adapter. Once a focusing electric field has been applied across the gel, proton ions migrating from the anolyte or hydroxide ions migrating from the catholyte can act as a desorbing agent, releasing the proteins from the MNE probes. The released proteins are consequently focused into distinct bands where the local pH equals their pI values. The at-line combination was well demonstrated with three types of functionalized nanoparticles: (1) phenylboronic acid functionalized MNPs for extracting glycoproteins through boronate affinity; (2) carboxyl-functionalized MNPs for extracting positively charged proteins through a weak cation exchange mechanism; and (3) amino-functionalized MNPs for extracting negatively charged proteins through a weak anion exchange mechanism. The at-line combination exhibited several significant advantages, including selectivity, sensitivity, and speed.

[Preparation of multi-functional magnetic nanoparticles for harvesting low-molecular-weight glycoproteins].

Low-molecular-weight glycoproteins (LMW-GPs) are considered promising candidates for disease biomarker discovery. Selective sorbents are essential for the extraction and enrichment of this class of compounds. Boronate affinity chromatography is a unique separation mode in liquid chromatography. It enables the selective separation and isolation of cis-diol-containing compounds such as glycoproteins and saccharides. Recent years have witnessed the rapid development of boronate affinity materials, particularly for use as selective sorbents in proteomics and metabolomics. However, studies are scarce on the specific design of such materials for the selective extraction of LMW-GPs. Herein, we present multifunctional magnetic nanoparticles (MNPs) for selectively harvesting LWM-GPs. The multifunctional MNPs were rationally designed and prepared by wrapping magnetic core nanoparticles with a phenylboronic acid-grafted poly(acrylic acid) (PAA) network. In addition to fulfilling the primary function of conventional MNPs in magnetic separation, multifunctional MNPs can offer three pre-determined advanced functions: 1) the size-restriction effect, which enables the elimination of the interference of high-molecular-weight proteins and other species; 2) the selective extraction of LMW-GPs; and 3) protection of the harvested LMW-GPs against degradation and contamination. The multifunctional MNPs enable selective extraction due to the affinity of the boronic acid ligand to the cis-diol moieties of the glycoproteins. The size-restriction effect and protection function depend on the polymer network on the surface of the MNPs, which allows the selective passage of low-molecular-weight molecules. Transmission electron microscopy (TEM) characterization showed that the MNPs were well-shaped nanoparticles, with a diameter of approximately 60 nm. The size-restriction effect was first predicted by a thermogravimetric analysis-based theoretical calculation, where for MNPs prepared using PAA with an average molecular weight of 240 kDa, the estimated pore size of the network was 0.9 nm. The boronate affinity and size-exclusion effect were verified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and capillary zone electrophoresis (CZE). To investigate the dependence of the selectivity of the MNPs to LMW-GPs in a complex environment and the size-restriction threshold for the PAA chain length, nano-liquid chromatography-tandem mass spectrometry (nano-LC-MS/MS) was performed to analyze the molecular mass of fragments harvested by the MNPs from the tryptic digest of horseradish peroxidase (HRP, a typical glycoprotein). The polymer chain length or the molecular weight of the PAA used played a critical role in determining the molecular weight thresholds of proteins above which the size exclusion effect will occur. The threshold values were found to be 5.0, 9.3, 4.1, 5.1, and 2.7 kDa for MNPs prepared using PAA with average molecular weights of 2, 5, 15, 100, and 240 kDa, respectively. This dependence enabled adjustment of the threshold value for inducing the size-exclusion effect of the multifunctional MNPs by changing the PAA chain length. The multifunctional MNPs can be further developed into promising nanoprobes for selectively harvesting not only LMW-GPs, but also other cis-diol-containing biomolecules of biological importance, such as nucleosides and glycans. Thus, the material preparation strategy reported herein offers new insights for the rational design and synthesis of multifunctional-affinity sorbents to selectively extract target compounds from a complex sample matrix.

Microplastics on beaches and mangrove sediments along the coast of South China.

Accumulation of microplastics (MPs) data on a global scale is key to supporting plastic waste management for protecting ecosystems. To respond this call, a sampling campaign was conducted in the summer and winter seasons of 2018 to collect beach and mangrove sediment samples from 32 sites along the coastline of South China. The MPs concentrations in the intertidal zone along the coast of South China were comparable to those in other regions around the world. Polystyrene foams and fibers were the most abundant debris in the 0.2-5 mm and 0.02-2 mm MPs, respectively. Principal component and correlation analyses indicated that the abundances of MPs were related to wind direction, wastewater discharge amount, and tourist and fishing activities. Risk assessments suggested that potential ecological risks induced by MPs on beaches and mangrove forest along the coast of South China should not be overlooked.

Development of a novel analytical method for inflammation and immunity-related metabolites in serum based on liquid chromatography tandem mass spectrometry.

Some metabolites have been found to play key roles in inflammation and immunity events that are associated with diseases such as cancer, diabetes and cytokine release syndrome. Characterization upon the inflammation and immunity-related metabolites (IIMs) will be helpful to the assessment of related pathological states. Although these metabolites have been partially reported in previous studies, the methods for specific measurement of them remain lacking. In the present study, a liquid chromatography - mass spectrometry based method was developed for the targeted analyses of 45 IIMs including amino acids, organic acids, phosphatidylcholines (PCs), polyunsaturated fatty acids and hormones selected based on the literature knowledge. Direct extraction with dansyl-chloride in acetonitrile was proved to be the most efficient and time-saving strategy, in which precipitation, extraction and derivatization were integrated. IIMs derivatized for 4 min and quenched for 2 min revealed the most comprehensive abundance. Based on the defined conditions, all the IIMs had a low limit of detection smaller than 1 ng/mL with the linear range greater than three orders of magnitude. The relative standard derivations of intra-day and inter-day precisions were ranged from 2.2% to 13.4% and 1.7% to 19.5%, respectively. The recovery rates and accuracy in low concentration were 98.9% ± 5.6% and 106.7% ± 11.6%, in medium concentration were 97.1% ± 6.8% and 106.9% ± 9.5%, and in high concentration were 98.4% ± 8.9% and 98.1% ± 8.1%, respectively. Matrix effect and stability were ranged from -37.8% to 35.6% and 2.9% to 14.2%, respectively. To show the usefulness of the method, serum IIMs in hepatitis B virus (HBV) infected patients and healthy subjects were determined and compared. Bile acids, lipoxygenase-mediated lipid mediators and non-enzymatic products showed global increases, whereas most of LysoPCs and cyclooxygenase-mediated prostaglandin D2 decreased in HBV serum samples. This study provided a robust approach for the characterization of IIMs.

NEU4 inhibits motility of HCC cells by cleaving sialic acids on CD44.

Hepatocellular carcinoma (HCC) is an extremely metastatic tumor. Sialic acids (SAs) are associated with cancer development and metastasis. NEU4 is a sialidase that removes SAs from glycoconjugates, while the function of the NEU4 in HCC has not been clearly explored. In our research, we found the NEU4 expression was significantly down-regulated in HCC tissues, which was correlated with high grades and poor outcomes of HCC. The NEU4 expression could be regulated by histone acetylation. In the functional analysis of NEU4, the cell motility was inhibited when NEU4 was overexpressed, and restored when NEU4 expression was down-regulated. Similarly, NEU4 over-expressed HCC cells showed less metastasis in athymic nude mice. Further study revealed that NEU4 could inhibit cell migration by enzymatic decomposition of SAs. Our results verified a NEU4 active site (NEU4E235) and overexpressing inactivates NEU4E235A that weakens the inhibition ability to cell migration. Further, 70 kinds of specific interacting proteins of NEU4 including CD44 were identified through mass spectrum. Moreover, the α2,3-linked SAs on CD44 were decreased and the hyaluronic acid (HA) binding ability was increased when NEU4 over-expressed or activated. Additionally, the mutation of CD44 with six N-glycosylation sites showed less sensibility to NEU4 on cell migration compared with wild-type CD44. In summary, our results revealed the mechanism of low expression of NEU4 in HCC and its inhibitory effect on cell migration by removal of SAs on CD44, which may provide new treatment strategies to control the motility and metastasis of HCC.

Effect of shikonin on the proliferation and apoptosis of human ovarian cancer cell SKOV3: A protocol of systematic review and meta-analysis.

BACKGROUND: This study will investigate the effect of shikonin on the proliferation and apoptosis of human ovarian cancer cell SKOV3 (HOCC-SKOV3). METHODS: We will retrieve potential studies from inception to the March 1, 2020 in Cochrane Library, MEDLINE, EMBASE, Scopus, Cumulative Index to Nursing and Allied Health Literature, WANGFANG, and China National Knowledge In-frastructure. There are not restrictions related to the language and publication status. This study will include case-controlled studies (CCSs) or randomized controlled studies (RCSs) that examine the effect of shikonin on the proliferation and apoptosis of HOCC-SKOV3. Two researchers will independently identify literatures, extract data, and appraise study quality. Any disagreements will be resolved by discussion with another researcher. RevMan 5.3 software will be placed to perform statistical analysis. RESULTS: This study will summarize the present evidence to test the effect of shikonin on the proliferation and apoptosis of HOCC-SKOV3. CONCLUSION: It will provide evidence to investigate the effect of shikonin on the proliferation and apoptosis of HOCC-SKOV3, and will supply reference for further study.Systematic review registration: INPLASY202040146.

Nucleobindin-2 enhances the epithelial-mesenchymal transition in renal cell carcinoma.

Nucleobindin 2 (NUCB-2) is a multifunctional protein that contains several functional domains and is associated with a wide variety of biological processes, such as food intake and energy homeostasis. NUCB-2 has been demonstrated to be associated with worse malignant outcomes and cell migration in breast and prostate cancer. However, to the best of our knowledge, its clinical and biological significance in renal cell carcinoma remains unknown. In the present study, tissue specimens from 68 patients with renal cell carcinoma and 10 normal controls were collected for NUCB-2 mRNA and protein assays. The NUCB-2 level in the patients with renal cell cancer was significantly increased compared with the normal control patients. NUCB-2-knockout in the renal cancer cell line SK-RC-52 inhibited migration and invasion. In addition, the expression levels of molecules associated with epithelial-mesenchymal transition (EMT), including E-cadherin, ß-catenin, Slug and Twist, were affected by NUCB-2 suppression and the zinc finger E-box binding to homeobox 1 (ZEB1)-dependent pathway. The AMP-dependent protein kinase (AMPK)/target of rapamycin complex (mTORC) 1 signaling pathway participates in the regulation of NUCB-2-mediated metastasis and EMT. Suppression of NUCB-2 also inhibited tumor nodule formation in a murine renal cell carcinoma tumor model. In summary, NUCB-2 increased migration, invasion and EMT in renal cell carcinoma cells through the AMPK/TORC1/ZEB1 pathway in vitro and in vivo.

Association between microRNA 25 expression in serum and lung cancer: A protocol for systematic review and meta-analysis.

BACKGROUND: This study aims to identify the association between microRNA 25 (mRNA 25) expression in serum and lung cancer (LC). METHODS: This planned study will cover all eligible case-controlled studies that report association between mRNA 25 expression in serum and LC. It will include published studies from inception to the present in Cochrane Library, PUBMED, EMBASE, Web of Science, Allied and Complementary Medicine Database, VIP database, and China National Knowledge Infrastructure regardless language and geographical location. We will also search other sources, such as conference abstracts and reference lists of related known studies and experts in the domain consulted to avoid missing potential studies. Two contributors will independently examine and select studies, collect all necessary data, and judge study quality for all included studies. We will perform statistical analysis using RevMan V.5.3 software and Stata V.12.0 software. RESULTS: This study will summarize current evidence to present first systematic review of research on the association between mRNA 25 expression in serum and LC. CONCLUSION: This study will present comprehensive evidence to determine whether mRNA 25 expression in serum is associated with LC, and will provide helpful evidence for the future studies. SYSTEMATIC REVIEW REGISTRATION: INPLASY202040056.