Effect of a topical steroid on gene expressions for chemokines in mice with contact hypersensitivity.

Effects of a topical corticosteroid drug, diflucortolone valerate, on the mRNA expressions for four CC- and four CXC-chemokines, which have been reported to be associated with recruitment of different kinds of proinflammatory and inflammatory cells, were investigated by RT-PCR in mice with 2,4,6-trinitrochlorobenzene (TNCB)-induced contact hypersensitivity (CHS) response. All of the eight gene expressions were clearly up-regulated in the lesion site of the CHS response up to 24 h post-challenge of TNCB at which ear swelling response reached a peak, so that heavy infiltration of inflammatory cells consisting mainly of mononuclear cells and neutrophils was likely induced by these chemokines. Topical treatment with diflucortolone valerate suppressed completely the infiltrates as well as the ear swelling response. In addition, the up-regulation of gene expressions for these eight chemokines were suppressed by the treatment, indicating that the corticosteroid drug attenuates the expression of chemokine genes essential for orientating nonspecific skin response to hapten-specific CHS response through the recruitment of inflammatory cells from the circulation into the tissue site.

A simple and robust method for preparation of cDNA nylon microarrays.

DNA array technology has made remarkable progress in recent years and has become an indispensable tool in molecular biology research. However, preparing high-quality custom-made DNA arrays at a reasonable cost is still an important concern because we cannot abandon the use of DNA array systems designed for specific purposes. To address these problems, we here report the use of rolling circle amplification products of cDNA plasmids dissolved in 80% formamide as DNA probes immobilized on a nylon membrane. First, because formamide is practically non-volatile under ambient conditions and nucleic acids are easily dissolved in it, the use of formamide as a DNA solvent ensures that the DNA concentration of the solution will not change during arraying, which often takes several hours to a day depending on the number of DNA spots and arrays to produce. Secondly, the use of rolling circle amplification technology greatly reduced the labor needed to prepare the spotted DNA. The results in this study demonstrate that the introduction of these two modifications in preparation of nylon DNA array greatly improved its quality.

Novel benzylidene-9(10H)-anthracenones as highly active antimicrotubule agents. Synthesis, antiproliferative activity, and inhibition of tubulin polymerization.

A novel series of 10-benzylidene-9(10H)-anthracenones and 10-(phenylmethyl)-9(10H)-anthracenones were synthesized and evaluated for antiproliferative activity in an assay based on K562 leukemia cells. The 3-hydroxy-4-methoxybenzylidene analogue 9h was found to be the most active compound (IC(50) K562: 20 nM). Structure-activity relationships are also considered. The highly active compound 9h and the 2,4-dimethoxy-3-hydroxybenzylidene analogue 9l were tested against five tumor cell lines using the XTT assay, including multidrug resistant phenotypes. Induction of cell death in a variety of tumor cell lines was determined in a monolayer assay using propidium iodide. Noteworthy, all compounds within the series induced elongations in K562 cells similar to vinblastine-treated cells. The effect of the lead compound 9h on K562 cell growth was associated with cell cycle arrest in G2/M. Concentrations for 50% KB/HeLa cells arrested in G2/M after treatment with 9h and 9l were determined and found to be in the range of 0.2 microM. Additionally, we monitored the dose dependent caspase-3-like protease activity in K562 cells and MCF-7/Casp-3 cells treated with 9h, indicating induction of apoptosis. Western blotting analysis demonstrated that 9h caused a shift in tubulin concentration from the polymerized state found in the cell pellet to the unpolymerized state found in the cell supernatant. Seven compounds strongly inhibited tubulin polymerization with activities higher or comparable to those of the reference compounds such as colchicine, podophyllotoxin, and nocodazole. In general, the antiproliferative activity correlated with inhibition of tubulin polymerization. The most active compounds strongly displaced [(3)H]colchicine from its binding site in the tubulin, yielding IC(50) values 3- to 4-fold lower than that of colchicine. The novel benzylidene-9(10H)-anthracenones described in the present study constitute an interesting group of highly active and easily accessible antimitotic agents that inhibit tubulin polymerization.

Kinetic profiles of sequential gene expressions for chemokines in mice with contact hypersensitivity.

Using cDNA microarray technology, the expression of chemokine genes in the elicitation site of 2,4,6-trinitrochlorobenzene-induced contact hypersensitivity (CHS) was examined in mice. Of the 33 genes analyzed, levels of 11 gene expressions changed, and these can be assigned to four groups based on their kinetic patterns; (1) LARC/CCL20 whose mRNA level increased rapidly at 3 h post-challenge and then gradually decreased, (2) JE/CCL2, MARC/CCL7, MIP-1gamma/CCL9, monocyte chemoattractant protein (MCP)-5/CCL12, ELC/CCL19 and BRAK/CXCL14 whose mRNA levels increased with time and reached the maximum at 6-9 h post-challenge, (3) LIX/CXCL5, Mig/CXCL9 and IP-10/CXCL10 whose mRNA levels increased gradually at least up to 12 h post challenge, and (4) SLC/CCL21 whose mRNA level decreased gradually with time after challenge. The findings suggest that sequential expression of chemokine genes is essential for orientating non-specific skin response to hapten-specific CHS response through the recruitment of inflammatory cells such as neutrophils, monocytes/macrophages and T-cells from the circulation into the tissue site.

Enhancement of sensitivity by bestatin of acute promyelocytic leukemia NB4 cells to all-trans retinoic acid.

All-trans retinoic acid (ATRA) induces the differentiation of acute promyelocytic leukemia (APL) cells into neutrophils. We found that bestatin, an inhibitor of CD13/aminopeptidase N, enhanced the sensitivity of APL NB4 cells to ATRA at concentrations of 0.1-1000ng/ml. A structurally different aminopeptidase N inhibitor, actinonin, also increased the effect of ATRA on differentiation, but an inactive stereoisomer of bestatin, (2R,3S)-AHPA-(R)-Leu, did not. Bestatin synergistically enhanced the cytostatic effect of ATRA on NB4 cells. Masking of the cell-surface CD13 by anti-CD13 antibody WM15 blocked the synergistic effect of bestatin and ATRA on differentiation. Thus bestatin, an immunomodulator clinically used for nonlymphocytic leukemia, synergistically increased the ATRA-induced differentiation of NB4 cells by inhibiting CD13/aminopeptidase N on the cell-surface.