Shigeyuki Usui

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Prostate-specific antigen (PSA), which is used as a marker for the diagnosis and monitoring of prostate cancer, is a kallikrein protease which could potentially play a role in human prostate cancer cell invasion. Zinc ions are effective inhibitors of a number of proteases. The enzymatic activity of purified PSA was strongly inhibited by Zn(2+). The ability(More)
Zinc levels in the prostate have been reported to be associated with the development and progression of malignant prostate cells. To investigate the reason why the zinc content decreases during the progression of prostate cancer to an androgen-independent state, we compared the expression levels of metallothionein and zinc transporters between(More)
Zinc is present at high concentrations in the prostate gland, however, the zinc-retention system in the prostate remains obscure. In this study, we investigated the expression of zinc transporters in the rat prostate and found that zinc transporter-2 (ZnT2), which sequesters zinc to the lysosome-like compartment, is expressed at high levels in the lateral(More)
For understanding the actions of magnesium formulations, magnesium oxide and magnesium sulfate as a constituent of antacid, in the gastrointestinal tract, the effect of magnesium ion on the water channel aquaporin 3 (AQP3) known to be permeable mainly to water and glycerol was investigated in Caco-2 cells. The mRNA and protein of aquaporin 3 were detected(More)
Acetaminophen (APAP) is widely used for the treatment of pain and fever. Although it is safe at therapeutic doses, APAP is toxic at higher doses and can cause severe damage to the liver. To clarify the mechanism of APAP-related liver damage, we attempted the identification of the differential gene expression in response to APAP treatment in hepatic HepG2(More)
BACKGROUND Bisphosphonates are widely used for the treatment and prevention of osteoporosis and are also effective in the treatment of bone metastasis of prostate cancer. Several mechanisms underlying the antitumor effect of bisphosphonates have been proposed, including direct effects on tumor cells, such as induction of apoptosis and inhibition of(More)
Prostate cancer is a heterogeneous disease with varying degrees of androgen sensitivity. In this study, we performed a limiting dilution of human prostate LNCaP cells, and isolated two sublines, LNCaP-E9 and LNCaP-G4, with differential hormone-sensitivity. Two LNCaP sublines were obtained by the limiting dilution method. The growth of E9 cells was decreased(More)
Aquaporin 9 (AQP9) is permeable to glycerol, which is a source material in lipogenesis and gluconeogenesis in the liver. We investigated the transcriptional regulation of the AQP9 gene by AMP-activated protein kinase (AMPK), known as an energy sensor in cells since AMPK contributes to the metabolism of carbohydrate, lipid, and protein by regulating the(More)
A water-soluble and low-molecular-weight fraction (SB) was obtained from tomato paste. The effects of SB on the formation of advanced glycation end-products (AGE) in protein glycation were studied by the methods of specific fluorescence, ELISA and a Western blot analysis, using the anti-AGE antibody after incubating protein with sugar. The results suggest(More)
Hepatic dysfunction due to flutamide administration has been reported and this side effect often limits the use of the agent. The prediction of flutamide-induced hepatotoxicity is attributed to the proper use of the antiandrogen. In this study, we investigated whether hepatic dysfunction could be assessed by the metabolite profile in serum from patients(More)