Integrating TCGA and Single-Cell Sequencing Data for Hepatocellular Carcinoma: A Novel Glycosylation (GLY)/Tumor Microenvironment (TME) Classifier to Predict Prognosis and Immunotherapy Response.

The major liver cancer subtype is hepatocellular carcinoma (HCC). Studies have indicated that a better prognosis is related to the presence of tumor-infiltrating lymphocytes (TILs) in HCC. However, the molecular pathways that drive immune cell variation in the tumor microenvironment (TME) remain poorly understood.

O1-conotoxin Tx6.7 cloned from the genomic DNA of that inhibits calcium currents.

Background: Conotoxins exhibit great potential as neuropharmacology tools and therapeutic candidates due to their high affinity and specificity for ion channels, neurotransmitter receptors or transporters. The traditional methods to discover new conotoxins are peptide purification from the crude venom or gene amplification from the venom duct.

Methods: In this study, a novel O1 superfamily conotoxin Tx6.

Corrigendum: Single-cell transcriptome analysis reveals the metabolic changes and the prognostic value of malignant hepatocyte subpopulations and predict new therapeutic agents for hepatocellular carcinoma.

[This corrects the article DOI: 10.3389/fonc.2023.

Single-cell transcriptome analysis reveals the metabolic changes and the prognostic value of malignant hepatocyte subpopulations and predict new therapeutic agents for hepatocellular carcinoma.

Background: The development of HCC is often associated with extensive metabolic disturbances. Single cell RNA sequencing (scRNA-seq) provides a better understanding of cellular behavior in the context of complex tumor microenvironments by analyzing individual cell populations.

Methods: The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) data was employed to investigate the metabolic pathways in HCC.

O-GlcNAcylation of SIRT1 enhances its deacetylase activity and promotes cytoprotection under stress.

SIRT1 is the most evolutionarily conserved mammalian sirtuin, and it plays a vital role in the regulation of metabolism, stress responses, genome stability, and ageing. As a stress sensor, SIRT1 deacetylase activity is significantly increased during stresses, but the molecular mechanisms are not yet fully clear. Here, we show that SIRT1 is dynamically modified with O-GlcNAc at Ser 549 in its carboxy-terminal region, which directly increases its deacetylase activity both in vitro and in vivo.

Inhibition of E-cadherin/catenin complex formation by O-linked N-acetylglucosamine transferase is partially independent of its catalytic activity.

p120-catenin (p120) contains a large central armadillo repeat domain, via which it binds to E‑cadherin to stabilize the latter, thereby regulating cell‑to‑cell adhesion. A previous study by our group demonstrated that O‑linked N‑acetylglucosamine (O‑GlcNAc) is involved in the regulation of the interaction between p120 and E‑cadherin. As O‑GlcNAc transferase (OGT) is able to directly bind to the majority of its target proteins, the present study hypothesized that OGT may additionally regulate the formation of the E‑cadherin/catenin complex independent of its catalytic activity.

A highly effective and adjustable dual plasmid system for O-GlcNAcylated recombinant protein production in E. coli.

O-GlcNAcylation is a ubiquitous, dynamic and reversible post-translational protein modification in metazoans, and it is catalysed and removed by O-GlcNAc transferase (OGT) and O-GlcNAcase, respectively. Prokaryotes lack endogenous OGT activity. It has been reported that coexpression of mammalian OGT with its target substrates in Escherichia coli produce O-GlcNAcylated recombinant proteins, but the plasmids used were not compatible, and the expression of both OGT and its target protein were induced by the same inducer.

O-GlcNAcylation is increased in prostate cancer tissues and enhances malignancy of prostate cancer cells.

O-GlcNAc is an O-linked ?-N-acetylglucosamine moiety attached to the side-chain hydroxyl of a serine or threonine residue in numerous cytoplasmic and nuclear proteins. In this study, we detected the level of O-GlcNAc in prostate, liver and pancreatic cancer tissues, and found that the global O-GlcNAc modification also known as O-GlcNAcylation, is specifically increased in prostate cancer tissues compared to corresponding adjacent tissues. In addition, we found that global O-GlcNAcylation is increased in prostate cancer cells and not in benign prostatic hyperplasia (BPH) epithelial cells.

O-GlcNAcylation is a novel regulator of lung and colon cancer malignancy.

O-GlcNAc is a monosaccharide attached to serine or threonine hydroxyl moieties on numerous nuclear and cytoplasmic proteins; O-GlcNAcylation is dynamically regulated by O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA). Although recent studies have shown that O-GlcNAcylation plays essential roles in breast cancer progression, it is also necessary to know whether O-GlcNAcylation is involved in other types of human cancer. In this study, O-GlcNAcylation levels and the expressions of OGT and OGA in human lung and colon cancer tissues were examined by immunohistochemistry analysis.

GlcNAcylation plays an essential role in breast cancer metastasis.

GlcNAcylation, a dynamic posttranslational modification, is involved in a wide range of biological processes and some human diseases. Although there is emerging evidence that some tumor-associated proteins are modified by GlcNAcylation, the role of GlcNAcylation in tumor progression remains unclear. Here, we show that GlcNAcylation enhances the migration/invasion of breast cancer cells in vitro and lung metastasis in vivo.