[A case of recurrent gastric cancer during adjuvant chemotherapy with S-1, treated by S-1 combination chemotherapy].

A 59-year-old man was admitted to our hospital for the treatment of gastric cancer with synchronous and multiple metastatic liver tumors. After total gastrectomy in February 2005, partial resection of the posterior segment of the liver was carried out in the next month. Pathological study of both the resected specimens showed moderately differentiated adenocarcinoma.

Phosphorothioate hammerhead ribozymes targeting a conserved sequence in the V3 loop region inhibit HIV-1 entry.

Seven different phosphorothioate DNA-RNA chimeric hammerhead ribozymes (RzV3-nT, n = 1-7) targeted against the V3 loop region of HIV-1 were synthesized. Two of these, RzV3-1T and RzV3-3T, efficiently cleaved transcribed envelope RNA of HXB2 in vitro. The target sequence of RzV3-1T belongs to a conserved region and is completely identical in the HIV-1 HXB2, NL432, and ADA strains.

Phosphorothiolate ribozyme against the conserved sequence in V3 loop of HIV-1.

Fluorescent-labeled phosphorothiolate DNA-RNA chimeric hammerhead ribozyme (thio-Rz) was synthesized. The ribozyme recognizes relatively conserved sequences in the functionally important region (V3 loop) of envelope protein of HIV-1. The thio-Rz as well as wild-type ribozyme cleaved RNA transcripts (414 base) of V3 region in a dose-dependent manner.

Enhanced E-cadherin expression and increased calcium-dependent cell-cell adhesion in human T-cell leukemia virus type I Tax-expressing PC12 cells.

Human T-cell leukemia virus type I (HTLV-I) Tax protein induces the expression of host cellular genes, some of which are crucial in cell proliferation and differentiation. We examined the mechanisms by which HTLV-I Tax protein induces phenotypic changes in PC12 cells. We demonstrated that the HTLV-I Tax gene induces epithelioid changes and increases cell-cell contact in PC12 cells.

Extraordinary enhancement of the cleavage activity of a DNA-armed hammerhead ribozyme at elevated concentrations of Mg2+ ions.

As part of an ongoing effort to characterize structure-function relationships, activities of all-RNA and DNA-armed hammerhead ribozymes were examined. An analysis of the dependence on the concentration of Mg2+ ions of cleavage rates revealed that, whereas the kcat of the reaction catalyzed by the all-RNA ribozyme reached a maximum value of about 18 min-1 at a concentration of about 200 mM Mg2+ ions, that of the DNA-armed ribozyme increased linearly as the concentration of Mg2+ ions was increased above 300 mM, finally reaching a value of more than 100 min-1 at 700 mM Mg2+ ions. These results suggest that the potential activity of a hammerhead ribozyme might be greater than is usually recognized.