Tsukasa Koiwa

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CpG methylation of the human T-cell leukemia virus type 1 (HTLV-1) long terminal repeat (LTR) has been implicated in proviral latency, but there is presently little information available regarding the pattern of LTR methylation and its effect on viral gene expression. To gain insight into the mechanisms of HTLV-1 latency, we have studied methylation of(More)
We previously described selective hypermethylation of the 5'-long terminal repeat (LTR) of HTLV-1 provirus in vivo and in vitro. This prompted us to analyze CpG methylation of the two LTRs of the HIV provirus in chronically infected cell lines. The results demonstrate selective hypermethylation of the 5' LTR of the HIV provirus in ACH-2 cells. Moreover,(More)
Telomerase is a cellular RNA-dependent DNA polymerase that serves to maintain the tandem arrays of telomeric TTAGGG repeats at eukaryotic chromosome ends. One of the human telomerase components is hTERT, which has three alternative spliced sites that introduce eight isoforms of hTERT mRNA. The expression of these isoforms in gastrointestinal cell lines is(More)
NPM-ALK characterizes anaplastic large cell lymphoma (ALCL), as does the high expression of CD30, a feature shared with H-RS cells of classic Hodgkin's lymphoma. In H-RS cells, ligand-independent signaling by overexpressed CD30 drives constitutive NF-kappaB activation, which is absent in ALCL cells. Here we show that NPM-ALK impedes CD30 signaling and(More)
Two new inhibitors of ICAM-1/LFA-1 mediated cell adhesion molecule, adxanthromycins A and B were isolated from the cultured broth of a streptomycete strain. The strain was identified as Streptomyces sp. NA-148 from its morphological and physiological characteristics. Adxanthromycins A and B inhibited the formation of the JY cell aggregates from 1.5(More)
Adxanthromycins A and B are new inhibitors of ICAM-1/LFA-1 mediated cell adhesion molecule isolated from the fermentation broth of Streptomyces sp. NA-148. The molecular formula of adxanthromycins A and B were determined as C42H40O17 and C48H50O22, respectively by FAB-MS and NMR spectral analyses, and the structures of both compounds were elucidated to be a(More)
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