Rational Design of a Parthenolide-based Drug Regimen That Selectively Eradicates Acute Myelogenous Leukemia Stem Cells.

Although multidrug approaches to cancer therapy are common, few strategies are based on rigorous scientific principles. Rather, drug combinations are largely dictated by empirical or clinical parameters. In the present study we developed a strategy for rational design of a regimen that selectively targets human acute myelogenous leukemia (AML) stem cells.

Acetylation-defective mutant of Pparγ is associated with decreased lipid synthesis in breast cancer cells.

In our prior publications we characterized a conserved acetylation motif (K(R)xxKK) of evolutionarily related nuclear receptors. Recent reports showed that peroxisome proliferator activated receptor gamma (PPARγ) deacetylation by SIRT1 is involved in delaying cellular senescence and maintaining the brown remodeling of white adipose tissue. However, it still remains unknown whether lysyl residues 154 and 155 (K154/155) of the conserved acetylation motif (RIHKK) in Pparγ1 are acetylated.

β-l-1-[5-(E-2-bromovinyl)-2-(hydroxymethyl)-1,3-(dioxolan-4-yl)] uracil (l-BHDU) prevents varicella-zoster virus replication in a SCID-Hu mouse model and does not interfere with 5-fluorouracil catabolism.

The alphaherpesvirus varicella-zoster virus (VZV) causes chickenpox and shingles. Current treatments are acyclovir (ACV) and its derivatives, foscarnet and brivudine (BVdU). Additional antiviral compounds with increased potency and specificity are needed to treat VZV, especially to treat post-herpetic neuralgia.

Modification of Streptococcus mutans Cnm by PgfS contributes to adhesion, endothelial cell invasion, and virulence.

Expression of the surface protein Cnm has been directly implicated in the ability of certain strains of Streptococcus mutans to bind to collagen and to invade human coronary artery endothelial cells (HCAEC) and in the killing of Galleria mellonella. Sequencing analysis of Cnm(+) strains revealed that cnm is located between the core genes SMU.2067 and SMU.

Bladder cancer exosomes contain EDIL-3/Del1 and facilitate cancer progression.

Purpose: High grade bladder cancer is an extremely aggressive malignancy associated with high rates of morbidity and mortality. Understanding how exosomes may affect bladder cancer progression could reveal novel therapeutic targets.

Materials And Methods: Exosomes derived from human bladder cancer cell lines and the urine of patients with high grade bladder cancer were assessed for the ability to promote cancer progression in standard assays.

Targeting aberrant glutathione metabolism to eradicate human acute myelogenous leukemia cells.

The development of strategies to eradicate primary human acute myelogenous leukemia (AML) cells is a major challenge to the leukemia research field. In particular, primitive leukemia cells, often termed leukemia stem cells, are typically refractory to many forms of therapy. To investigate improved strategies for targeting of human AML cells we compared the molecular mechanisms regulating oxidative state in primitive (CD34(+)) leukemic versus normal specimens.

The human biliverdin reductase-based peptide fragments and biliverdin regulate protein kinase Cδ activity: the peptides are inhibitors or substrate for the protein kinase C.

PKCδ, a Ser/Thr kinase, promotes cell growth, tumorigenesis, and apoptosis. Human biliverdin reductase (hBVR), a Ser/Thr/Tyr kinase, inhibits apoptosis by reducing biliverdin-IX to antioxidant bilirubin. The enzymes are activated by similar stimuli.

Proteoglycan: site mapping and site-directed mutagenesis.

Identification of proteoglycan chain modification sites cannot yet be reliably predicted from primary amino acid sequence data. A number of studies have shown that serine is the predominant amino acid that is modified and it is frequently flanked by a C-terminal glycine and proximal N-terminal acidic amino acids; however, not all simple Ser-Gly motifs constitute a modification site. Here we present a rapid method for cloning small, defined segments of putative proteoglycan attachment sites and expressing them as a mini-reporter protein in an insect tissue culture system that is expandable to high throughput analysis.

Identification of membrane-bound variant of metalloendopeptidase neurolysin (EC 3.4.24.16) as the non-angiotensin type 1 (non-AT1), non-AT2 angiotensin binding site.

Recently, we discovered a novel non-angiotensin type 1 (non-AT1), non-AT2 angiotensin binding site in rodent and human brain membranes, which is distinctly different from angiotensin receptors and key proteases processing angiotensins. It is hypothesized to be a new member of the renin-angiotensin system. This study was designed to isolate and identify this novel angiotensin binding site.

Aspirin acetylates multiple cellular proteins in HCT-116 colon cancer cells: Identification of novel targets.

Epidemiological and clinical observations provide consistent evidence that regular intake of aspirin may effectively inhibit the occurrence of epithelial tumors; however, the molecular mechanisms are not completely understood. In the present study, we determined the ability of aspirin to acetylate and post-translationally modify cellular proteins in HCT-116 human colon cancer cells to understand the potential mechanisms by which it may exerts anti-cancer effects. Using anti-acetyl lysine antibodies, here we demonstrate that aspirin causes the acetylation of multiple proteins whose molecular weight ranged from 20 to 200 kDa.

Melampomagnolide B: a new antileukemic sesquiterpene.

Melampomagnolide B has been identified as a new antileukemic sesquiterpene. A biotin-conjugated derivative of melampomagnolide B was designed and synthesized in order to elucidate its mechanism of action. A study of the biochemical interactions of the biotin probe suggests that melampomagnolide B derives its remarkable selectivity for leukemic cells over normal hematopoietic cells from its unique ability to exploit biochemical differences between the two cell types.

Human common salivary protein 1 (CSP-1) promotes binding of Streptococcus mutans to experimental salivary pellicle and glucans formed on hydroxyapatite surface.

The saliva proteome includes host defense factors and specific bacterial-binding proteins that modulate microbial growth and colonization of the tooth surface in the oral cavity. A multidimensional mass spectrometry approach identified the major host-derived salivary proteins that interacted with Streptococcus mutans (strain UA159), the primary microorganism associated with the pathogenesis of dental caries. Two abundant host proteins were found to tightly bind to S.

Quantitative analysis of age specific variation in the abundance of human female parotid salivary proteins.

Human saliva is a protein-rich, easily accessible source of potential local and systemic biomarkers to monitor changes that occur under pathological conditions; however, little is known about the changes in abundance associated with normal aging. In this study, we performed a comprehensive proteomic profiling of pooled saliva collected from the parotid glands of healthy female subjects, divided into two age groups 1 and 2 (20-30 and 55-65 years old, respectively). Hydrophobic charge interaction chromatography was used to separate high- from low-abundance proteins prior to characterization of the parotid saliva using multidimensional protein identification technology (MudPIT).

Proteomic analysis of human parotid gland exosomes by multidimensional protein identification technology (MudPIT).

Human ductal saliva contributes over a thousand unique proteins to whole oral fluids. The mechanism by which most of these proteins are secreted by salivary glands remains to be determined. The present study used a mass spectrometry-based, shotgun proteomics approach to explore the possibility that a subset of the proteins found in saliva are derived from exosomes, membrane-bound vesicles of endosomal origin within multivesicular endosomes.

The proteomes of human parotid and submandibular/sublingual gland salivas collected as the ductal secretions.

Saliva is a body fluid with important functions in oral and general health. A consortium of three research groups catalogued the proteins in human saliva collected as the ductal secretions: 1166 identifications--914 in parotid and 917 in submandibular/sublingual saliva--were made. The results showed that a high proportion of proteins that are found in plasma and/or tears are also present in saliva along with unique components.

Initiation of protein O glycosylation by the polypeptide GalNAcT-1 in vascular biology and humoral immunity.

Core-type protein O glycosylation is initiated by polypeptide N-acetylgalactosamine (GalNAc) transferase (ppGalNAcT) activity and produces the covalent linkage of serine and threonine residues of proteins. More than a dozen ppGalNAcTs operate within multicellular organisms, and they differ with respect to expression patterns and substrate selectivity. These distinctive features imply that each ppGalNAcT may differentially modulate regulatory processes in animal development, physiology, and perhaps disease.

Systematic Analysis of proteoglycan modification sites in Caenorhabditis elegans by scanning mutagenesis.

Proteoglycan modification is essential for development and early cell division in Caenorhabditis elegans. The specification of proteoglycan attachment sites is defined by the Golgi enzyme polypeptide xylosyltransferase. Here we evaluate the substrate specificity of this xylosyltransferase for its downstream targets by using reporter proteins containing proteoglycan modification sites from C.

The terminal phase of cytokinesis in the Caenorhabditis elegans early embryo requires protein glycosylation.

RNA interference (RNAi) was used to characterize the requirement of protein glycosylation for cell membrane stability during cytokinesis in the early embryo. This screen targeted 13 enzymes or components of polypeptide sugar transferases that initiate either N-glycosylation or three different pathways of O-glycosylation. RNAi of genes in the mucin-type and epidermal growth factor-fringe glycosylation pathways did not affect cytokinesis.

cDNA cloning and expression of UDP-N-acetyl-D-galactosamine:polypeptide N-acetylgalactosaminyltransferase T1 from Toxoplasma gondii.

We report the cloning, expression, and characterization of the first UDP-GalNAc:polypetide N-acetylgalactosaminyltransferase (ppGalNAc-T) from the human disease-causing parasite, Toxoplasma gondii. This enzyme is also the first characterized ppGalNAc-T of protozoan origin. This type of enzyme catalyzes the initial step of mucin-type O-glycosylation, that is, the transfer of GalNAc in O-glycosidic linkage to serine and threonine residues in polypeptides.