CTNet: Contrastive Transformer Network for Polyp Segmentation.

Segmenting polyps from colonoscopy images is very important in clinical practice since it provides valuable information for colorectal cancer. However, polyp segmentation remains a challenging task as polyps have camouflage properties and vary greatly in size. Although many polyp segmentation methods have been recently proposed and produced remarkable results, most of them cannot yield stable results due to the lack of features with distinguishing properties and those with high-level semantic details. Therefore, we proposed a novel polyp segmentation framework called contrastive Transformer network (CTNet), with three key components of contrastive Transformer backbone, self-multiscale interaction module (SMIM), and collection information module (CIM), which has excellent learning and generalization abilities. The long-range dependence and highly structured feature map space obtained by CTNet through contrastive Transformer can effectively localize polyps with camouflage properties. CTNet benefits from the multiscale information and high-resolution feature maps with high-level semantic obtained by SMIM and CIM, respectively, and thus can obtain accurate segmentation results for polyps of different sizes. Without bells and whistles, CTNet yields significant gains of 2.3%, 3.7%, 3.7%, 18.2%, and 10.1% over classical method PraNet on Kvasir-SEG, CVC-ClinicDB, Endoscene, ETIS-LaribPolypDB, and CVC-ColonDB respectively. In addition, CTNet has advantages in camouflaged object detection and defect detection. The code is available at https://github.com/Fhujinwu/CTNet.

Regulating Relative Nitrogen Locations of Diazine Functionalized Covalent Organic Frameworks for Overall H2 O2 Photosynthesis.

Nitrogen-heterocycle-based covalent organic frameworks (COFs) are considered promising candidates for the overall photosynthesis of hydrogen peroxide (H2 O2 ). However, the effects of the relative nitrogen locations remain obscured and photocatalytic performances of COFs need to be further improved. Herein, a collection of COFs functionalized by various diazines including pyridazine, pyrimidine, and pyrazine have been judiciously designed and synthesized for photogeneration of H2 O2 without sacrificial agents. Compared with pyrimidine and pyrazine, pyridazine embedded in TpDz tends to stabilize endoperoxide intermediate species, leading toward the more efficient direct 2e- oxygen reduction reaction (ORR) pathway. Benefiting from the effective electron-hole separation, low charge transfer resistance, and high-efficiency ORR pathway, an excellent production rate of 7327 µmol g-1 h-1 and a solar-to-chemical conversion (SCC) value of 0.62 % has been achieved by TpDz, which ranks one of the best COF-based photocatalysts. This work might shed fresh light on the rational design of functional COFs targeting photocatalysts in H2 O2 production.

Ultrathin and Porous 2D PtPdCu Nanoalloys as High-Performance Multifunctional Electrocatalysts for Various Alcohol Oxidation Reactions.

We precisely synthesized two-dimensional (2D) PtPdCu nanostructures with the morphology varying from porous circular nanodisks (CNDs) and triangular nanoplates (TNPs) to triangular nanoboomerangs (TNBs) by tuning the molar ratios of metal precursors. The PtPdCu trimetallic nanoalloys exhibit superior electrocatalytic performances to alcohol oxidation reactions due to their unique structural features and the synergistic effect. Impressively, PtPdCu TNBs exhibit a high mass activity of 3.42 mgPt+Pd-1 and 1.06 A·mgPt-1 for ethanol and methanol oxidation compared to PtPd, PtCu, and pure Pt, which is 3.93 and 4.07 times that of commercial Pt/C catalysts, respectively. Moreover, 2D PtPdCu TNPs and PtPdCu CNDs also show a highly improved electrocatalytic activity. Furthermore, as all-in-one electrocatalysts, PtPdCu nanoalloys display excellent electrocatalytic activity and stability toward the oxidation of other alcohol molecules, such as isopropyl alcohol, glycerol, and ethylene glycol. The enhanced mechanism was well proposed to be the abundant active sites and upshifted d-band center based on density functional theory calculations.

TM2D1 contributes the epithelial-mesenchymal transition of hepatocellular carcinoma via modulating AKT/ß-catenin axis.

Various epidemiology studies showed the correlation between Alzheimer's disease (AD) and low incidence of cancer. However, the etiology underlying etiology of AD-related carcinogenesis remains largely elusive. Our study focused on characterizing the role of TM2D1 (TM2 domain containing 1) in hepatocellular carcinoma. TM2D1 is also known as ß-amyloid peptide binding protein and is critical to the pathogenesis of AD. We found that TM2D1 is increasingly expressed in HCC tumors relative to the peritumoral tissues of the matched tumors and high TM2D1 expression predicts unfavorable clinical outcomes. TM2D1 overexpression induced HCC cell proliferation, migration and invasion, which was related to the epithelial-mesenchymal transition (EMT) observed in these cells. Conversely, TM2D1 depletion led to opposite phenotype in HCC. Mechanistically, we found that TM2D1 promoted Akt and ß-catenin hyper-activation, which corresponded with molecular marker change in EMT signaling pathway. Taken together, our results indicated that TM2D1 played an important role in the EMT process in HCC cells by activating AKT and ß-catenin signaling and may become a promising therapeutic target in HCC.

Platinum-Based Electrocatalysts for Direct Alcohol Fuel Cells: Enhanced Performances toward Alcohol Oxidation Reactions.

In the past few decades, Pt-based electrocatalysts have attracted great interests due to their high catalytic performances toward the direct alcohol fuel cell (DAFC). However, the high cost, poor stability, and the scarcity of Pt have markedly hindered their large-scale utilization in commerce. Therefore, enhancing the activity and durability of Pt-based electrocatalysts, reducing the Pt amount and thus the cost of DAFC have become the keys for their practical applications. In this minireview, we summarized some basic concepts to evaluate the catalytic performances in electrocatalytic alcohol oxidation reaction (AOR) including electrochemical active surface area, activity and stability, the effective approaches for boosting the catalytic AOR performance involving size decrease, structure and morphology modulation, composition effect, catalyst supports, and assistance under other external energies. Furthermore, we also presented the remaining challenges of the Pt-based electrocatalysts to achieve the fabrication of a real DAFC.

Ru Nanoworms Loaded TiO2 for Their Catalytic Performances toward CO Oxidation.

Ruthenium nanocrystals with small size and special morphology are of great interest in various catalytic reactions due to their high activities. However, it is still a great challenge to downsize these nanocatalysts to a sub-nano scale (<2 nm). Herein, we reported a synthesis of ultrasmall size and uniform Ru nanoparticles through a rapid one-pot method. The prepared Ru nanocrystal shows a wormlike shape, in which the diameter is as thin as 1.6 ± 0.3 nm and the length is 13.6 ± 4.4 nm. These Ru nanoworms (NWs) are quite steady during the synthetic process even though the reaction time was further prolonged. We also examined their catalytic activity toward CO oxidation by loading Ru NWs on TiO2 to form Ru NWs/TiO2 catalysts. These catalysts exhibit a high activity of 100% CO conversion at 150 °C, which is much lower than the normal Ru NPs/TiO2 nanostructures. Based on our detailed investigations, we proposed that the small size, special morphology, and TiO2 support are the keys for their significantly improved catalytic activity. We believed that these reasonable discoveries provide a methodology and opportunity to get highly active catalysts for CO oxidation by a detailed increase in their active sites.

Dodecahedral Au/Pt Nanobowls as Robust Plasmonic Electrocatalysts for Methanol Oxidation under Visible-Light Illumination.

Plasmonic nanostructures with large absorption areas under resonant excitation have been utilized extensively in photon-assisted applications. In this work, dodecahedral Au nanobowls were first prepared by an easy and template-free method only through the introduction of H2 PtCl6 and I- during the growth procedure. The Au nanobowls show electron-field enhancement due to the high curvature of the bowl edge, the open region, and dodecahedral morphology. Au/Pt nanobowls, which couple plasmonic Au and catalytic Pt, were then constructed as plasmonic electrocatalysts for methanol oxidation. The mass activity reached 497.6 mA mg-1 under visible-light illumination, which is 1.9 times that measured in the dark. Simultaneously, the electrocatalytic stability is also greatly improved under light excitation. The enhanced properties of the plasmonic Au/Pt electrocatalysts are ascribed to the synergistic effect of the plasmon-enhanced photothermal and hot-carrier effects on the basis of experimental investigations. This work thus offers an effective methodology to construct efficient plasmonic electrocatalysts for fuel cells.

Identification of FOS as a Candidate Risk Gene for Liver Cancer by Integrated Bioinformatic Analysis.

Liver cancer is a lethal disease that is associated with poor prognosis. In order to identify the functionally important genes associated with liver cancer that may reveal novel therapeutic avenues, we performed integrated analysis to profile miRNA and mRNA expression levels for liver tumors compared to normal samples in The Cancer Genome Atlas (TCGA) database. We identified 405 differentially expressed genes and 233 differentially expressed miRNAs in tumor samples compared with controls. In addition, we also performed the pathway analysis and found that mitogen-activated protein kinases (MAPKs) and G-protein coupled receptor (GPCR) pathway were two of the top significant pathway nodes dysregulated in liver cancer. Furthermore, by examining these signaling networks, we discovered that FOS (Fos proto-oncogene, AP-1 transcription factor subunit), LAMC2 (laminin subunit gamma 2), and CALML3 (calmodulin like 3) were the most significant gene nodes with high degrees involved in liver cancer. The expression and disease prediction accuracy of FOS, LAMC2, CALML3, and their interacting miRNAs were further performed using a HCC cohort. Finally, we investigated the prognostic significance of FOS in another HCC cohort. Patients with higher FOS expression displayed significantly shorter time to recurrence (TTR) and overall survival (OS) compared with patients with lower expression. Collectively, our study demonstrates that FOS is a potential prognostic marker for liver cancer that may reveal a novel therapeutic avenue in this lethal disease.

HSP4 triggers epithelial-mesenchymal transition and promotes motility capacities of hepatocellular carcinoma cells via activating AKT.

BACKGROUND AND AIMS: Heat shock factor (HSF4) plays a vital role in carcinogenesis and tumour progression. However, its clinical significance implications in hepatocellular carcinoma (HCC) remained elusive. METHODS: RT-PCR and western blot were used to detect the HSF4 expression levels in HCC cells and tissues. Immunohistochemistry staining was performed on a tissue microarray containing 104 HCC patients received radical resection. In vitro effects of HSF4 on proliferation, migration and invasion were determined by colony formation and transwell assays in HCCLM3, Huh7, MHCC97L and SMMC7721 cells. Epithelial-mesenchymal transition (EMT) was identified by RT-PCR, WB and immunofluorescence in HCCLM3 and MHCC97L cells. AKT pathway activation was detected by WB and dual luciferase report system in HCCLM3 and MHCC97L cells. RESULTS: HSF4 expression was higher in primary HCC tissues derived from recurrent patients, and positively correlated with invasiveness potentials of cell lines. Clinically, patients with high HSF4 expression had significant poorer prognosis. In vitro experiments showed HSF4 silencing inhibited HCC cell proliferation, migration and invasion, whereas HSF4 overexpression had inverse effects. Moreover, silence of HSF4 induced an epithelial-like phenotype, whereas the overexpression of HSF4 resulted in a mesenchymal-like phenotype in HCC by activating AKT pathway. Further experiments showed that HSF4 could activate AKT pathway in a hypoxia-inducible factor-1α (HIF-1α) dependent, but transforming growth factor-ß (TGF-ß) independent manner. CONCLUSIONS: HSF4 is upregulated in HCC, resulting in greater proliferation, migration and invasion capacities. Moreover, high HSF4 expression is a promising predictive indicator of poor outcome after radical resection. HSF4 may promote aggressive tumour behaviour by enhancing EMT through activating AKT pathway in a HIF1α-dependent manner.

Far upstream element-binding protein 1 facilitates hepatocellular carcinoma invasion and metastasis.

Previous research suggests that far upstream element-binding protein 1 (FUBP1) plays an important role in various tumors including epatocellular carcinoma (HCC). However, the role of FUBP1 in liver cancer remains controversial, and the regulatory pathway by FUBP1 awaits to be determined. This study aims to identify the role of FUBP1 in HCC progression. Our result shows that the high level of FUBP1 expression in HCC predicts poor prognosis after surgery. Overexpression of FUBP1 promotes HCC proliferation, invasion, and metastasis by activating transforming growth factor-ß (TGF-ß)/Smad pathway and enhancing epithelial-mesenchymal transition (EMT) in vitro and in vivo. Inhibitor of Thrombospondin-1 (LSKL) could inhibit HCC proliferation and invasion in vitro and in vivo by blocking the activation of TGF-ß/Smad pathway mediated by thrombospondin-1 (THBS1). Our study identified the critical role of FUBP1-THBS1-TGF-ß signaling axis in HCC and provides potentially new therapeutic modalities in HCC.

Metadherin-PRMT5 complex enhances the metastasis of hepatocellular carcinoma through the WNT-ß-catenin signaling pathway.

Accumulating data suggest that metadherin (MTDH) may function as an oncogene. Our previous study showed that MTDH promotes hepatocellular carcinoma (HCC) metastasis via the epithelial-mesenchymal transition. In this study, we aim to further elucidate how MTDH promotes HCC metastasis. Using Co-immunoprecipitation (co-IP) and mass spectrometry, we found that MTDH can specifically bind to protein arginine methyltransferase 5 (PRMT5). Further functional assays revealed that PRMT5 overexpression promoted the proliferation and motility of HCC cells and that knockout of PRMT5 impeded the effect of MTDH. The immunohistochemistry assay/tissue microarray results showed that when MTDH was overexpressed in HCC cells, PRMT5 translocated from the nucleus to the cytoplasm, with the subsequent translocation of ß-catenin from the cytoplasm to the nucleus and upregulation of the WNT-ß-catenin signaling pathway. Further in vivo experiments suggested that PRMT5 and ß-catenin played a pivotal role in MTDH-mediated HCC metastasis. We therefore concluded that the MTDH-PRMT5 complex promotes HCC metastasis by regulating the WNT-ß-catenin signaling pathway.

TGM3 promotes epithelial-mesenchymal transition and hepatocellular carcinogenesis and predicts poor prognosis for patients after curative resection.

BACKGROUND: Prognosis of hepatocellular carcinoma (HCC) remains poor despite significant recent improvement in therapy. Recent studies have reported that transglutaminase 3 (TGM3) plays an important role in several human cancer types. However, the role of TGM3 in HCC have not been previously elucidated. METHODS: We evaluated the role of TGM3 in regulating HCC cell proliferation, migration, and invasion. We also investigated the prognostic significance of TGM3 in an HCC cohort. Finally, we explored the signalling pathways that TGM3 regulates in HCC. RESULTS: We identified TGM3 to be overexpressed in HCC compared to normal tissues. Higher expression of TGM3 predicts poor prognosis in HCC patients. TGM3 knockdown led to decreased HCC cell proliferation, invasion, and xenograft tumour growth. TGM3 depletion inhibited AKT, extracellular signal-regulated kinase (ERK), p65, and glycogen synthase kinase 3ß (GSK3ß)/ß-catenin activation, but promoted levels of cleaved caspase 3. Moreover, TGM3 knockdown cells had increased E-cadherin levels and decreased vimentin levels, suggesting that TGM3 contributes to epithelial-mesenchymal transition (EMT) in HCC. CONCLUSION: Our results suggest that TGM3 controls multiple oncogenic pathways in HCC, thereby contributing to increased cell proliferation and EMT, and TGM3 potentially enhances HCC metastasis. TGM3 may serve as a novel therapeutic target in HCC.

KPNA3 Confers Sorafenib Resistance to Advanced Hepatocellular Carcinoma via TWIST Regulated Epithelial-Mesenchymal Transition.

Sorafenib, a multikinase inhibitor, is a new standard treatment for patients with advanced hepatocellular carcinoma (HCC). However, resistance to this regimen is frequently observed in clinical practice, and the molecular basis of this resistance remains largely unknown. Herein, the antitumor activity of sorafenib was assessed in 16 patient-derived xenograft (PDX) models of HCC. Gene expression analysis was conducted to identify factors that promote sorafenib resistance. Quantitative RT-PCR and immunoblotting were used to determine gene expression and activation of signaling pathways. Cell proliferation, clone formation, and transwell assays were conducted to evaluate drug-sensitivity, proliferation, and invasiveness, respectively. Kaplan-Meier analysis was used to evaluate the predictive power of biomarkers for sorafenib response. Differential gene expression analysis suggested that sorafenib resistance correlated with high karyopherin subunit alpha 3 (KPNA3) expression. Overexpression of KPNA3 in HCC cells enhanced tumor cell growth and invasiveness. Interestingly, KPNA3 was found to trigger epithelial-mesenchymal transition (EMT), a key process mediating drug resistance. On a mechanistic level, KPNA3 increased phosphorylation of AKT, which then phosphorylated ERK, and ultimately promoted TWIST expression to induce EMT and sorafenib resistance. Moreover, retrospective analysis revealed that HCC patients with low KPNA3 expression had remarkably longer survival after sorafenib treatment. Finally, we have identified a novel KPNA3-AKT-ERK-TWIST signaling cascade that promotes EMT and mediates sorafenib resistance in HCC. These findings suggest that KPNA3 is a promising biomarker for predicting patient responsiveness to sorafenib. Targeting KPNA3 may also contribute to resolving sorafenib resistance in HCC.

Whole-Exome Sequencing-Based Mutational Profiling of Hepatitis B Virus-Related Early-Stage Hepatocellular Carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) ranks as the third leading cause of cancer-related mortality in China with increasing incidence. This study is designed to explore early genetic changes implicated in HCC tumorigenesis and progression by whole-exome sequencing. METHODS: We firstly sequenced the whole exomes of 5 paired hepatitis B virus-related early-stage HCC and peripheral blood samples, followed by gene ontological analysis and pathway analysis of the single-nucleotide variants discovered. Then, the mutations of high frequency were further confirmed by Sanger sequencing. RESULTS: We identified a mutational signature of dominant T:A>A:T transversion in early HCC and significantly enriched pathways including ECM-receptor interaction, axon guidance, and focal adhesion and enriched biological processes containing cell adhesion, axon guidance, and regulation of pH. Eight genes, including MUC16, UNC79, USH2A, DNAH17, PTPN13, TENM4, PCLO, and PDE1C, were frequently mutated. CONCLUSIONS: This study reveals a mutational profile and a distinct mutation signature of T:A>A:T transversion in early-stage HCC with HBV infection, which will enrich our understanding of genetic characteristics of the early-stage HCC.

Tumour-suppressive role of PTPN13 in hepatocellular carcinoma and its clinical significance.

Hepatocellular carcinoma (HCC) is the second leading cause of cancer mortality and carries a dismal prognosis. The present study aimed to identify the tumour-suppressive role and clinical implications of PTPN13 in HCC progression. We tested the effects of PTPN13 expression in proliferation, invasion, epithelial-mesenchymal transition and associated pathways in HCC cell lines in vitro. Furthermore, its clinical relevance was evaluated in a tissue microarray analysis of samples from 282 HCC patients. Various HCC cell lines expressed relatively low PTPN13 protein levels in vitro. PTPN13 overexpression significantly inhibited the progression of HCC cells, possibly by inhibiting epithelial-mesenchymal transition through inactivation of the EGFR/ERK signalling pathway. Tissue microarray analysis revealed that high PTPN13 expression was correlated with a favourable prognosis in postoperative HCC patients. This study demonstrated the tumour suppressor, PTPN13, as an alternative therapeutic target for HCC.

Expression of hemopexin in acute rejection of rat liver allograft identified by serum proteomic analysis.

Acute rejection (AR) and acceptance of allograft after liver transplantation (LTx) remain critical issues that need addressing to improve prognosis. We therefore performed rat orthotopic LTx and proteomic analyses to screen for immune response-related biomarkers in sera. Markers identified were validated at the mRNA and/or protein levels, and the molecules of interest were functionally explored. Compared with syngeneic controls, signs of AR as well as spontaneous acceptance were observed in hematoxylin and eosin-stained sections of liver allografts. In accordance with the severity of AR, 30 protein spots displaying significant changes in abundance were identified using two-dimensional differential gel electrophoresis. Ultimately, 14 serum proteins were sequenced and five spots of interest were identified as hemopexin (HPX). Expression of HPX was significantly and inversely associated with the severity of AR at both the mRNA and protein levels. In vitro, Mt-1, Ho-1, Fth, Ifn-γ, and Il-17 transcripts were significantly upregulated in lysates of lymphocytes stimulated with HPX, whereas Il-10 markedly was remarkably downregulated. Interferon-γ, IL-10, and IL-17 proteins in the supernatant of HPX-stimulated lymphocytes were significantly altered in keeping with the mRNA level. Our data facilitated the generation of a proteomic profile to enhance the understanding of rat liver AR. In view of finding that the HPX serum level is negatively associated with the severity of AR of rat liver allograft, we propose that in vitro treatment with HPX regulates cytokine expression in rat lymphocytes.