mPGES-1 as a target for cancer suppression : A comprehensive invited review “Phospholipase A2 and lipid mediators”

Prostaglandin E₂ (PGE₂) is a bioactive lipid that can elicit a wide range of biological effects associated with inflammation and cancer. The physiological roles of PGE₂ are diverse, mediated in part through activation of key downstream signaling cascades via transmembrane EP receptors located on the cell surface. Elevated levels of COX-2 and concomitant overproduction of PGE₂ are often found in human cancers. These observations have led to the use of non-steroidal anti-inflammatory drugs (NSAIDs) as chemopreventive agents, particularly for colorectal cancer (CRC). Their long-term use, however, may be associated with gastrointestinal toxicity and increased risk of adverse cardiovascular events, prompting the development of other enzymatic targets in this pathway. This review will focus on recent efforts to target the terminal synthase, mPGES-1, for cancer chemoprevention. The role of mPGES-1 in the pathogenesis of various cancers is discussed. In addition, an overview of recent efforts to develop small molecule inhibitors that target the protein with high selectivity is also be reviewed.     

Laminar high shear stress up-regulates type IV collagen synthesis and down-regulates MMP-2 secretion in endothelium. A quantitative analysis

Remodeling of endothelial basement membrane is important in atherogenesis. Since little is known about the actual relationship between type IV collagen and matrix metalloprotease−2 (MMP-2) in endothelial cells (ECs) under shear stress by blood flow, we performed quantitative analysis for type IV collagen and MMP-2 in ECs under high shear stress. The mRNA of type IV collagen from ECs exposed to high shear stress (10 and 30 dyn/cm²) had a higher expression compared to ECs exposed to a static condition or low shear stress (3 dyn/cm²) (P < 0.01). ³H-proline uptake analysis and fluorography revealed a remarkable increase of type IV collagen under high shear stress (P < 0.01). In contrast, zymography revealed that exposing to high shear stress, however similar positivity was leveled in the intracellular MMP-2 in the control and high shear stress-exposed ECs, reduced the secretion of MMP-2 in ECs. The results of Northern blotting, gelatin zymography and monitoring the intracellular trafficking of GFP-labeled MMP-2 revealed that MMP-2 secretion by ECs was completely suppressed by high shear stress, but the intracellular mRNA expression, protein synthesis, and transport of MMP-2 were not affected. In conclusion, we suggest that high shear stress up-regulates type IV collagen synthesis and down-regulates MMP-2 secretion in ECs, which plays an important role in remodeling of the endothelial basement membrane and may suppress atherogenesis.     

Intracellular Phospholipase A1 and Acyltransferase, Which Are Involved in Caenorhabditis elegans Stem Cell Divisions, Determine the sn-1 Fatty Acyl Chain of Phosphatidylinositol

Phosphatidylinositol (PI), an important constituent of membranes, contains stearic acid as the major fatty acid at the sn-1 position. This fatty acid is thought to be incorporated into PI through fatty acid remodeling by sequential deacylation and reacylation. However, the genes responsible for the reaction are unknown, and consequently, the physiological significance of the sn-1 fatty acid remains to be elucidated. Here, we identified acl-8, -9, and -10, which are closely related to each other, and ipla-1 as strong candidates for genes involved in fatty acid remodeling at the sn-1 position of PI. In both ipla-1 mutants and acl-8 acl-9 acl-10 triple mutants of Caenorhabditis elegans, the stearic acid content of PI is reduced, and asymmetric division of stem cell-like epithelial cells is defective. The defects in asymmetric division of these mutants are suppressed by a mutation of the same genes involved in intracellular retrograde transport, suggesting that ipla-1 and acl genes act in the same pathway. IPLA-1 and ACL-10 have phospholipase A₁ and acyltransferase activity, respectively, both of which recognize the sn-1 position of PI as their substrate. We propose that the sn-1 fatty acid of PI is determined by ipla-1 and acl-8, -9, -10 and crucial for asymmetric divisions.     

Development of Multiplex PCR to Detect Five Pythium Species Related to Turfgrass Diseases

The objective of this study was to develop multiplex PCR detection method for five Pythium species associated with turfgrass diseases, Pythium aphanidermatum, Pythium arrhenomanes, Pythium graminicola, Pythium torulosum and Pythium vanterpoolii. Species‐specific primers and two common primers were designed based on the sequences of the internal transcribed spacer region of ribosomal DNA. Another primer set by which all organisms would be amplified in 18S rDNA was used as a positive control. When these total nine primers were applied to the multiplex PCR, all species were individually discriminated in the mixture of five species culture DNA. Furthermore, all five Pythium species were detected in naturally infected plants using the multiplex PCR.     

Characterisation of recombinant pyranose oxidase from the cultivated mycorrhizal basidiomycete <Emphasis Type="Italic">Lyophyllum shimeji</Emphasis> (hon-shimeji)

Background  

The flavin-dependent enzyme pyranose 2-oxidase (P2Ox) has gained increased attention during the last years because of a number of attractive applications for this enzyme. P2Ox is a unique biocatalyst with high potential for biotransformations of carbohydrates and in synthetic carbohydrate chemistry. Recently, it was shown that P2Ox is useful as bioelement in biofuel cells, replacing glucose oxidase (GOx), which traditionally is used in these applications. P2Ox offers several advantages over GOx for this application, e.g., its much broader substrate specificity. Because of this renewed interest in P2Ox, knowledge on novel pyranose oxidases isolated from organisms other than white-rot fungi, which represent the traditional source of this enzyme, is of importance, as these novel enzymes might differ in their biochemical and physical properties.     

Development of a novel fluorometric assay for nitric oxide utilizing sesamol and its application to analysis of nitric oxide‐releasing drugs

Nitric oxide (NO) is related to various physiological effects as well as to numerous diseases caused by accentuation of NO production. Measurement of NO in cells and tissues is difficult as NO readily reacts with other molecules; furthermore, its half‐life as a radical is fleeting. Currently, many NO pharmaceuticals are marketed as therapeutic agents for ischemic disease. Consequently, the identification of NO radicals and determination of generation rate from pharmaceuticals is very important when the effect of the medicinal supply is estimated. In this study, we developed a fluorometric assay for NO employing sesamol (3,4‐methylenedioxyphenol) as a fluorometric substrate. Sesamol is converted to a fluorescent derivative (ex. 365 nm, em. 447 nm), which is dimmer in the presence of NO. The detection limit of NO with this method is 400 fmol; moreover, NO generated from drugs can be measured. Copyright © 2009 John Wiley & Sons, Ltd.     

Identification of a novel type of CA19-9 carrier in human bile and sera of cancer patients: an implication of the involvement in nonsecretory exocytosis

Carbohydrate antigen 19-9 (CA19-9) is a well-known tumor marker for pancreatic cancer. Although the CA19-9 level is measured using anti-sialyl Lewis A antibodies, it remains unknown which molecules carry CA19-9 other than mucins. Here we report the identification and characterization of a novel type of CA19-9 carrier, BGM (bile globular membrane), which is thought to exist in normal bile and to be secreted into sera of patients with pancreatic cancer. We purified the BGM from bile juice using a β-casein column because surface plasmon resonance analysis could detect such carrier vesicles binding to β-casein in sera of patients with pancreatic cancer. We identified characteristic molecules for BGM such as AHNAK (desmoykoin) and a novel golgin family member, CABIN (CAsein Binding domain integral protein with golgIN motif) by mass spectrometry analysis. BGM was detected in the sera of patients with pancreatic cancer as well as athymic mice with transplanted pancreatic cancer cells. Down regulation of CABIN inhibited the secretion of CA19-9 on BGM in pancreatic cancer cell lines. We measured and visualized BGM in sera of patients with cancer. Thus, BGM might be another CA19-9 carrier (glyco-lipids on membrane vesicles) other than mucins and could be applied to the diagnosis of pancreatic cancer.     

Experimental eradication of pinworms (Syphacia obvelata and Aspiculuris tetraptera) from mice colonies using ivermectin.

A spray administration of ivermectin was evaluated for the treatment of pinworm infection in mice. In this study, a spray of 0.1% ivermectin injectable solution over the entire cage once a week, for three consecutive weeks (one cycle treatment), was effective in eradicating both Syphacia obvelata and Aspiculuris tetraptera from mice under experimental conditions. In addition, no acute toxicity was observed in 105 mothers or 687 neonates treated with ivermectin, indicating that ivermectin does not affect murine reproduction. Finally, we attempted to eradicate pinworms from infected mice in our institute using this method. Two cycles of treatment were administered, with a two-week pause between cycles, resulting in complete eradication for at least one year. Treating mouse colonies with spray ivermectin is inexpensive, safe, requires very little labor and is very effective at eradicating pinworms from mice.