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In order to investigate how glucocorticoids affect the expression of secretory leukocyte peptidase inhibitor (SLPI), which is overexpressed in a variety of cancers, clobetasol was added to cell culture medium of U937 cells and the SLPI mRNA levels were examined. The in vitro effect of the treatment on SLPI expression was detected by reverse transcriptase-polymerase chain reaction. Clobetasol treatment of U937 cells induced an up- and down-regulation of SLPI expression in a dose-dependent manner. Western blotting confirmed the down-regulation of SLPI protein expression. We hypothesized a loop formation in the SLPI genome domain, in which the glucocorticoid receptor regulates bi-directional transcriptional activity.

Cip-interacting zinc finger protein 1 (Ciz1) stimulates DNA replication and has been implicated in the tumorigenesis of breast cancer cells. In order to investigate the possibility of using medicinal glucocorticoids against breast cancer, we studied whether certain glucocorticoids affect the expression of Ciz1. The in vitro effect of clobetasol treatment on the reduction of Ciz1 expression was detected by reverse transcriptase-polymerase chain reaction. Western blotting also confirmed the down-regulation of the protein in a dose-dependent manner upon clobetasol treatment in U937 monocytoid cells. Furthermore, we found that Ciz1 protein expression was decreased after pre-treatment of the cells with clobetasol and genistein. An extract of Lens culinaris also had a synergistic effect on the repression of Ciz1 protein expression.

The aim of this study was to determine the effects of several food ingredients and chemical inhibitors on the expression of presenilin, a molecule involved in γ-secretase activity and the generation of amyloid-β peptide in Alzheimer's disease. Western blotting revealed the downregulation of presenilin 1 protein expression by stimulation with genistein in vitro, while the effects on presenilin 1 gene expression examined by reverse transcriptase-polymerase chain reaction (RT-PCR) were unaltered in Daudi cells. Genistein likely downregulates presenilin via the inhibition of ubiquilin 1 expression in lymphoid cells. Our findings provide new insights that may help to establish preventive strategies against Alzheimer's disease.

RUN domain is present in several proteins related to the functions of Rap and Rab family GTPases. Accumulating evidence supports the hypothesis that RUN domain-containing proteins act as a component of vesicle traffic and might be responsible for an interaction with a filamentous network linked to actin cytoskeleton or microtubules. That is to say, on one hand, RUN domains associate with Rab or Rap family proteins, on the other hand, they also might interact with motor proteins such as kinesin or myosin via intervention molecules. In this review, we summarize the background and current status of RUN domain research with an emphasis on the interaction between RUN domain and motor proteins with respect to the vesicle traffic on filamentous network.

SIRT1 is a mammalian candidate molecule involved in longevity and diverse metabolic processes. The present study aimed to determine the effects of certain herbs and spices on SIRT1 expression. Human cell lines Daudi, Jurkat, U937 and K562 were cultured in RPMI-1640. Herb and spice powders were prepared and the supernatants were collected. RT-PCR was used to quantify the expression level of the gene. Protein samples were then analyzed by Western blotting. Western blotting revealed the down-regulation of SIRT1 protein expression in Daudi cells treated with extracts of black pepper or turmeric. On the other hand, the effect on the SIRT1 gene expression examined by reverse transcription polymerase chain reaction was unaltered. In conclusion, component(s) of certain herbs and spices may induce the down-regulation of SIRT1 protein.