Kinetic analysis of paramyxovirus-sialoglycan receptor interactions reveals virion motility.

Many viruses initiate infection by binding to sialoglycan receptors at the cell surface. Binding to such receptors comes at a cost, however, as the sheer abundance of sialoglycans e.g. in mucus, may immobilize virions to non-functional decoy receptors. As a solution, sialoglycan-binding as well as sialoglycan-cleavage activities are often present in these viruses, which for paramyxoviruses are combined in the hemagglutinin-neuraminidase (HN) protein. The dynamic interactions of sialoglycan-binding paramyxoviruses with their receptors are thought to be key determinants of species tropism, replication and pathogenesis. Here we used biolayer interferometry to perform kinetic analyses of receptor interactions of animal and human paramyxoviruses (Newcastle disease virus, Sendai virus, and human parainfluenza virus 3). We show that these viruses display strikingly different receptor interaction dynamics, which correlated with their receptor-binding and -cleavage activities and the presence of a second sialic acid binding site. Virion binding was followed by sialidase-driven release, during which virions cleaved sialoglycans until a virus-specific density was reached, which was largely independent of virion concentration. Sialidase-driven virion release was furthermore shown to be a cooperative process and to be affected by pH. We propose that paramyxoviruses display sialidase-driven virion motility on a receptor-coated surface, until a threshold receptor density is reached at which virions start to dissociate. Similar motility has previously been observed for influenza viruses and is likely to also apply to sialoglycan-interacting embecoviruses. Analysis of the balance between receptor-binding and -cleavage increases our understanding of host species tropism determinants and zoonotic potential of viruses.

Identification of Hub Genes to Regulate Breast Cancer Spinal Metastases by Bioinformatics Analyses.

Breast cancer (BC) had been one of the deadliest types of cancers in women worldwide. More than 65% of advanced-stage BC patients were identified to have bone metastasis. However, the molecular mechanisms involved in the BC spinal metastases remained largely unclear. This study screened dysregulated genes in the progression of BC spinal metastases by analyzing GSE22358. Moreover, we constructed PPI networks to identify key regulators in this progression. Bioinformatics analysis showed that these key regulators were involved in regulating the metabolic process, cell proliferation, Toll-like receptor and RIG-I-like receptor signaling, and mRNA surveillance. Furthermore, our analysis revealed that key regulators, including C1QB, CEP55, HIST1H2BO, IFI6, KIAA0101, PBK, SPAG5, SPP1, DCN, FZD7, KRT5, and TGFBR3, were correlated to the OS time in BC patients. In addition, we analyzed TCGA database to further confirm the expression levels of these hub genes in breast cancer. Our results showed that these regulators were significantly differentially expressed in breast cancer, which were consistent with GSE22358 dataset analysis. Furthermore, our analysis demonstrated that CEP55 was remarkably upregulated in the advanced stage of breast cancer compared to the stage I breast cancer sample and was significantly upregulated in triple-negative breast cancers (TNBC) compared to other types of breast cancers, including luminal and HER2-positive cancers, demonstrating CEP55 may have a regulatory role in TNBC. Finally, our results showed that CEP55 was the most highly expressed in Basal-like 1 TNBC and Basal-like 2 TNBC samples but the most lowly expressed in mesenchymal stem-like TNBC samples. Although more studies are still needed to understand the functions of key regulators in BC, this study provides useful information to understand the mechanisms underlying BC spinal metastases.

Film-Spotting chiral miniPEG-γPNA array for BRCA1 gene mutation detection.

Peptide nucleic acids array technology is a method of greatly increasing the throughput of laboratory processes to efficiently perform large-scale genetic tests. Diethylene glycol-containing chiral γPNA (miniPEG-γPNA) is considered to be the best PNA derivative and one of the best candidates for gene detection, because it can hybridize DNA with greater affinity and sequence selectivity than DNA and ordinary aminoethylglycyl PNA (aegPNA). Herein, miniPEG-γPNA probes are synthesized by 9-fluorenylmethyloxycarbonyl (Fmoc) solid phase peptide synthesis (SPPS) in a mild condition, and a new biochip fabrication method "Film-Spotting" is invented, by which γPNA arrays with regular pattern, uniform luminance, and very low fluorescence background are obtained easily and cheaply. The miniPEG-γPNA array can effectively distinguish the full matched and mismatched targets in SSarc buffer, serum and urine, and the detection limit of complementary DNA is less than 5.97 nM. A miniPEG-γPNA array for BRCA1 gene mutation (3099delT) detection is also fabricated with a very good detection performance. This work provides an effective avenue for the diagnosis of breast cancer biomarker and expands the application of miniPEG-γPNA in the field of biochip.

High-Throughput Approaches in Carbohydrate-Active Enzymology: Glycosidase and Glycosyl Transferase Inhibitors, Evolution, and Discovery.

Carbohydrates are attached and removed in living systems through the action of carbohydrate-active enzymes such as glycosyl transferases and glycoside hydrolases. The molecules resulting from these enzymes have many important roles in organisms, such as cellular communication, structural support, and energy metabolism. In general, each carbohydrate transformation requires a separate catalyst, and so these enzyme families are extremely diverse. To make this diversity manageable, high-throughput approaches look at many enzymes at once. Similarly, high-throughput approaches can be a powerful way of finding inhibitors that can be used to tune the reactivity of these enzymes, either in an industrial, a laboratory, or a medicinal setting. In this review, we provide an overview of how these enzymes and inhibitors can be sought using techniques such as high-throughput natural product and combinatorial library screening, phage and mRNA display of (glyco)peptides, fluorescence-activated cell sorting, and metagenomics.

Increased Six1 expression is associated with poor prognosis in patients with osteosarcoma.

Sine oculis homeobox homolog 1 (Six1) is an evolutionarily conserved transcription factor that acts as master regulator of development and is frequently dysregulated in various types of cancer. Six1 has been demonstrated to be upregulated in human osteosarcoma cell lines compared with osteoblastic cell lines. However, the association of Six1 expression with the progression and prognosis of osteosarcoma patients remains unclear. The purpose of the present study was to investigate the association between Six1 expression and the clinicopathological characteristics and prognosis of osteosarcoma. Six1 protein was detected by immunohistochemistry in a series of 100 osteosarcoma patients, and Kaplan-Meier survival analysis was performed to assess prognosis. The results revealed that increased Six1 protein expression was prevalent in osteosarcoma and was significantly associated with Enneking stage (P=0.002) and tumor size (P=0.010). Additionally, according to the log-rank test and Cox regression model, expression of Six1 is indicated to be an independent prognostic factor in osteosarcoma patients. In summary, positive expression of Six1 protein is closely associated with the tumor progression and poor survival of osteosarcoma patients. The results suggest that Six1 is a overexpressed in individuals with poor prognosis, and may thus be used as a prognostic biomarker in patients with osteosarcoma.