hymecromone and Neoplasms

In vertebrates, the glucuronidation of small lipophilic agents is catalyzed by the endoplasmic reticulum UDP-glucuronosyltransferases (UGTs). This metabolic pathway leads to the formation of water-soluble metabolites originating from normal dietary processes, cellular catabolism, or exposure to drugs and xenobiotics. This classic detoxification process, which led to the discovery nearly 50 years ago of the cosubstrate UDP-glucuronic acid (19), is now known to be carried out by 15 human UGTs. Characterization of the individual gene products using cDNA expression experiments has led to the identification of over 350 individual compounds that serve as substrates for this superfamily of proteins. This data, coupled with the introduction of sophisticated RNA detection techniques designed to elucidate patterns of gene expression of the UGT superfamily in human liver and extrahepatic tissues of the gastrointestinal tract, has aided in understanding the contribution of glucuronidation toward epithelial first-pass metabolism. In addition, characterization of the UGT1A locus and genetic studies directed at understanding the role of bilirubin glucuronidation and the biochemical basis of the clinical symptoms found in unconjugated hyperbilirubinemia have uncovered the structural gene polymorphisms associated with Crigler-Najjar's and Gilbert's syndrome. The role of the UGTs in metabolism and different disease states in humans is the topic of this review.

Topics: Autoimmunity; Chromosome Mapping; Glucuronides; Glucuronosyltransferase; Humans; Hyperbilirubinemia; Neoplasms; Steroids; Terminology as Topic

NAD(P)H:quinone oxidoreductase 1 (NQO1) is a flavoenzyme upregulated in response to oxidative stress and in some cancers. Its upregulation by compounds has been used as an indicator of their potential anti-cancer properties. In this study we have designed, produced and tested a fluorogenic coumarin conjugate which selectively releases highly fluorescent 4-methylumbelliferone (4-MU) in the presence of NQO1. It was found that measuring 4-MU release rapidly and specifically quantitated NQO1 levels in vitro and in live cells. Both the substrate and its products freely perfused through cell membranes and were non-toxic. The substrate was very specific with low background, and the assay itself could be done in less than 10minutes. This is the first assay to allow the quantitation of NQO1 in live cells which can then be retained for further experiments.

Topics: Biomarkers; Cell Line, Tumor; Cell Membrane; Cell Membrane Permeability; Coumarins; Fluorescent Dyes; Humans; Hymecromone; NAD(P)H Dehydrogenase (Quinone); Neoplasms; Oxidative Stress; Up-Regulation

The synthesis of derivatives of 4-Methylumbelliferone (4-MUs), which are structurally interesting antioxidants, was performed in this study. The modification of 4-Methylumbelliferone (4-MU) by different reaction steps was performed to yield the target compounds, the 4-MUs. The 4-MUs were characterized by different spectroscopic techniques (Fourier transform infrared; FT-IR and Nuclear magnetic resonance; NMR) and micro-elemental analysis (CHNS). The in vitro antioxidant activity of the 4-MUs was evaluated in terms of their free radical scavenging activities against 2,2-diphenyl-1-picrylhydrazyl (DPPH), Nitric oxide radical scavenging activity assay, chelating activity and their (FRAP) ferric-reducing antioxidant power, which were compared with a standard antioxidant. Our results reveal that the 4-MUs exhibit excellent radical scavenging activities. The antioxidant mechanisms of the 4-MUs were also studied. Density Function Theory (DFT)-based quantum chemical studies were performed with the basis set at 3-21G. Molecular models of the synthesized compounds were studied to understand the antioxidant activity. The electron levels, namely HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital), for these synthesized antioxidants were also studied.

Topics: Biphenyl Compounds; Cell Line, Tumor; Free Radical Scavengers; Humans; Hydrogen Peroxide; Hymecromone; Models, Molecular; Neoplasms; Nitric Oxide; Nuclear Magnetic Resonance, Biomolecular; Oxidation-Reduction; Picrates; Spectroscopy, Fourier Transform Infrared; Triazines

Sixteen furoxan-based nitric oxide (NO) releasing coumarin derivatives (6a-c, 8a-g, 10a, 13a,b, 15, and 17a,b) were designed, synthesized, and evaluated against the A549, HeLa, A2780, A2780/CDDP, and HUVEC cell lines. Most derivatives displayed potent antiproliferation activities. Among them, 8b exhibited the strongest antiproliferation activity on the four sensitive cell lines mentioned above and three drug resistant tumor cell lines A2780/CDDP, MDA-MB-231/Gem, and SKOV3/CDDP with IC50 values from 14 to 53 nM and from 62 to 140 nM, respectively. Furthermore, 8b inhibited the growth of A2780 in vivo and displayed lower toxicity on nontumorigenesis T29, showing good selectivity against malignant cells in vitro. Preliminary pharmacological studies showed that 8b induces apoptosis, arrests the cell cycle at the G2/M phase in the A2780 cell line, and disrupts the phosphorylation of MEK1 and ERK1. Overall, the NO-releasing capacity and the inhibition of ERK/MAPK pathway signaling may explain the potent antineoplastic activity of these compounds.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Carcinogenesis; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Coumarins; Drug Combinations; Drug Screening Assays, Antitumor; Female; HeLa Cells; Human Umbilical Vein Endothelial Cells; Humans; Inhibitory Concentration 50; MAP Kinase Kinase 1; Mice; Mice, Inbred BALB C; Mice, Nude; Mitogen-Activated Protein Kinase 3; Neoplasms; Nitric Oxide; Oxadiazoles; Signal Transduction

Hyaluronan accumulation on cancer cells and their surrounding stroma predicts an unfavourable disease outcome, suggesting that hyaluronan enhances tumor growth and spreading. 4-Methylumbelliferone (4-MU) inhibits hyaluronan synthesis and retards cancer spreading in experimental animals through mechanisms not fully understood. These mechanisms were studied in A2058 melanoma cells, MCF-7 and MDA-MB-361 breast, SKOV-3 ovarian and UT-SCC118 squamous carcinoma cells by analysing hyaluronan synthesis, UDP-glucuronic acid (UDP-GlcUA) content, and hyaluronan synthase (HAS) mRNA levels. The maximal inhibition in hyaluronan synthesis ranged 22-80% in the cell lines tested. Active glucuronidation of 4-MU produced large quantities of 4-MU-glucuronide, depleting the cellular UDP-GlcUA pool. The maximal reduction varied between 38 and 95%. 4-MU also downregulated HAS mRNA levels: HAS3 was 84-60% lower in MDA-MB-361, A2058 and SKOV-3 cells. HAS2 was the major isoenzyme in MCF-7 cells and lowered by 81%, similar to 88% in A2058 cells. These data indicate that both HAS substrate and HAS2 and/or HAS3 mRNA are targeted by 4-MU. Despite different target point sensitivities, the reduction of hyaluronan caused by 4-MU was associated with a significant inhibition of cell migration, proliferation and invasion, supporting the importance of hyaluronan synthesis in cancer, and the therapeutic potential of hyaluronan synthesis inhibition.

Topics: Base Sequence; Breast Neoplasms; Cell Line, Tumor; Cell Movement; Cell Proliferation; DNA Primers; Down-Regulation; Female; Glucuronosyltransferase; Humans; Hyaluronan Synthases; Hyaluronic Acid; Hymecromone; Melanoma; Neoplasm Invasiveness; Neoplasms; RNA, Messenger; RNA, Neoplasm; Uridine Diphosphate Glucuronic Acid

To investigate whether the activity of lysosomal enzymes is increased in the peritoneal fluid of patients with gynecologic cancers compared to activity in the peritoneal fluid from normal subjects and those with pelvic inflammatory disease, and fluid from benign ovarian cysts.. beta-glucuronidase, beta-galactosidase, and alpha-mannosidase activity was measured in the peritoneal fluid from patients with gynecologic cancer, pelvic inflammatory disease, and normal subjects, and fluid from benign ovarian cysts.. The mean+/-SD of beta-glucuronidase, beta-galactosidase, and alpha-mannosidase activity in the gynecologic cancers was 120+/-50 nmol, 203+/-86 nmol, and 240+/-119 nmol 4-methylumbelliferone/ml/h, respectively; in the normal control subjects it was 22+/-9 nmol, 46+/-10 nmol, and 80+/-23 nmol, respectively (P=0.00003, 0.0001, and 0.0001, respectively). The activity was increased even in cases without malignant cells in the peritoneal fluid. In pelvic inflammatory disease it was 148+/-82 nmol, 278+/-112 nmol, and 291+/-140 nmol, respectively. The activity in the fluid of the ovarian cysts was similar to that of the normal peritoneal fluid. There was a significant positive correlation between enzyme activity and stage of cancer, that was stronger for beta-glucuronidase (r=0.889, P=0.003).. The increased lysosomal enzyme activity in gynecologic cancers, without overlapping between patients and normal subjects or benign ovarian cyst fluid, indicates that such measurements might be applied for diagnostic purposes.

Topics: Adenocarcinoma; Adenocarcinoma, Clear Cell; Adenocarcinoma, Mucinous; alpha-Mannosidase; Ascitic Fluid; beta-Galactosidase; Case-Control Studies; Cystadenocarcinoma, Serous; Endometrial Neoplasms; Female; Glucuronidase; Humans; Hymecromone; Lysosomes; Neoplasms; Ovarian Cysts; Ovarian Neoplasms; Pelvic Inflammatory Disease

We describe a kinetic, fluorometric assay for urinary N-acetyl-beta-glucosaminidase (EC 3.2.1.30) by measurement of the release of 4-methylumbelliferone (7-hydroxy-4-methylcoumarin). The method is simple, involving only a single reagent, and is applicable to the assay of other enzymes that hydrolyze similar fluorescent-labeled substrates. The enzyme distribution in human tissues and fluids is described. The enzyme is present in high concentrations in human kidney, liver, and lung. Its concentration in urine is shown to be a sensitive indicator of early renal damage, which precedes changes in serum creatinine and urinary protein. Assay of the enzyme is quite useful in monitoring renal damage due to myoglobinuria.

Topics: Acetylglucosaminidase; Adult; Autoanalysis; Hexosaminidases; Humans; Hymecromone; Kidney Diseases; Myoglobinuria; Neoplasms; Spectrometry, Fluorescence; Tissue Distribution