Establishment of a variety of human bone marrow stromal cell lines by the recombinant SV40-adenovirus vector.

Various human bone marrow stromal cell lines were established from the adherent cell populations by introduction of the recombinant SV40-adenovirus vector with an infection or electric poration procedure. As compared with DNA transfection, the vector introduction was able to immortalize the cells with more than 100 times higher efficiency. Morphological and cytochemical analyses indicated that various cloned cell lines with different properties were isolated by the vector introduction. All the established cell lines expressed SV40 large T antigen. These results provided the evidence indicating that the recombinant SV40-adenovirus vector was a useful tool to establish a variety of cell lines with different biological activities from human bone marrow stroma.     

Augmentation of retinoic acid-induced granulocytic differentiation in HL-60 leukemia cells by serine/threonine protein phosphatase inhibitors.

To evaluate the involvement of protein phosphatases (PP) in differentiation of human myelogenous leukemia HL-60 cells, we made use of potent inhibitors of PP1 and PP2A, calyculin-A (CAL-A) and okadaic acid (OKA). CAL-A and OKA could augment all-trans retinoic acid (ATRA)-induced granulocytic differentiation, whereas the differentiation toward macrophage lineage by 12-o-tetradecanoylphorbol acetate (TPA) was unchanged in the presence of CAL-A. CAL-A augmented the phosphorylation of 18K, 23K and 30K proteins induced by ATRA. The PP1 and PP2A were identified and were present mainly in the cytosol of HL-60 cells. These results suggest that either PP1 or PP2A or both may be involved in regulating granulocytic differentiation of HL-60 cells.     

Neurocalcin: a novel calcium-binding protein from bovine brain.

A novel calcium-binding protein (molecular weight 23,000-24,000, pI 5.3-5.5), which we term neurocalcin, was identified in bovine brain. Using calcium-dependent drug affinity chromatography ((S)-P-(2-aminoethyloxy)-N-[2-(4-benzyloxycarbonylpiperazinyl++ +)-1-(P- methoxybenzyl)ethyl]-N-methylbenzene-sulfonamide dihydrochloride, W-77, -coupled Sepharose 6B), we purified neurocalcin from bovine brain. The partial amino acid sequence of neurocalcin revealed it to be an as yet unidentified protein with three putative calcium binding sites (EF-hands). Further purification and sequence analysis demonstrated the presence of four isoprotein forms designated alpha, beta, gamma 1, and gamma 2. When the 165 sequenced residues of neurocalcin beta are compared with sequences of other proteins, neurocalcin beta has a 38.2% sequence homology with visinin and 45.5% with recoverin (Yamagata, K., Goto, K., Kuo, C.-H., Kondo, H., and Miki, N. (1990) Neuron 2, 469-476; Dizhoor, A. M., Ray, S., Kumar, S., Niemi, G., Spencer, M., Brolley, D., Walsh, K. A., Philipov, P. P., Hurley, J. B., and Stryer, L. (1991) Science 251, 915-918). Both visinin and recoverin are expressed specifically in retinal photoreceptors and are not found in brain. Unlike visinin and recoverin, neurocalcin is purified not only from retina but also from bovine brain. Our results suggest that neurocalcin is a recoverin-like protein expressed in bovine brain.     

Genetic polymorphism of alpha-2-HS-glycoprotein: four new alleles and allele frequencies in Japanese

alpha 2-HS-glycoprotein (AHSG) phenotyping was done in 655 Japanese from the Goto Islands, western Japan, using isoelectric focusing followed by immunoblotting. Four new AHSG alleles were encountered, AHSG*G1-G4, whose genetic transmissions were established in family studies. The allele frequencies were: AHSG*1 = 0.7221; AHSG*2 = 0.2748, and AHSG*G1-G4 = 0.0008, respectively.     

Oxidative modification of glycated low density lipoprotein in the presence of iron

This is the first observation for contributing to the glycation of low density lipoprotein (LDL) to oxidative modification of its own lipids and protein. Human plasma LDL was glycated by incubation with glucose (G-LDL). Glucose incorporated into apoprotein B was approximately 10 mol/mol of apoprotein (2.8% modification of lysine residues) and 84% of G-LDL was adsorbed on phenylboronate affinity column. G-LDL incubated with Fe3+ for 4 h caused a significantly higher level of lipid peroxidation than U-LDL (untreated with glucose), and a higher molecular weight protein was observed in apoprotein B on SDS-polyacrylamide gel electrophoresis (SDS-PAGE), increasing with incubation period. Corresponding to change on SDS-PAGE, G-LDL exposed to Fe3+ moved faster than G-LDL per se or U-LDL to anode on agarose gel electrophoresis. The higher the Fe3+ concentration, the more lipid peroxidation was caused. Alpha-tocopherol or probucol suppressed the lipid peroxidation of G-LDL exposed to Fe3+.     

Establishment and characterization of new cell lines from human renal cell carcinoma

We have characterized seven human renal cell carcinoma cell lines established from primary sites of five patients between 1987 and 1989. Two lines, OUR-20P and OUR-20S, were derived from the OUR-20 cells by cloning with a dilution method 3 months after the primary culture. These three cell lines were tumorigenic in athymic nude mice when inoculated subcutaneously. Examined by a dye uptake method, OUR-20 was highly sensitive to interferon-alpha (IFN-alpha); OUR-20P, OUR-20S and OUR-30 showed slight sensitivities, while the other three cell lines were insensitive. All seven cell lines have been maintained for more than 2 years and over 50 passages in vitro. Cytogenetic analyses performed 1.5 to 3 years after the starts of primary cultures indicated that all seven cell lines, which exhibited different morphologies in phase-contrast micrographs, were aneuploid with modal chromosome numbers 41 to 89.     

Covalent modification and single-strand scission of DNA by a new antitumor antibiotic kapurimycin A3

Kapurimycin A3 is a new antitumor antibiotic isolated from a Streptomyces. It contains the anthrapyrone skeleton and a beta,gamma-unsaturated delta-keto carboxylic acid moiety in the structure. In vitro, kapurimycin causes single-strand cleavage of supercoiled pBR322 DNA. The diminished cytotoxicity and DNA cleaving activity for 13-decarboxykapurimycin A3 indicates that the beta, gamma-unsaturated delta-keto carboxylic acid moiety is important for the activity of kapurimycin. Kapurimycin A3 binds to calf thymus DNA at 4 degrees C, and the thermal treatment of this adduct results in release of a guanine covalently attached to C-16 of kapurimycin via one of its nitrogen atoms. Thus, the epoxide is the alkylating functional group of kapurimycin, and this is consistent with the lack of DNA cleaving and cytotoxic activities for 14,16-deoxy-14,16-dihydroxykapurimycin. These findings have revealed that DNA strand scission by kapurimycin is due to the alkylation of guanine by ring opening of the epoxide group of kapurimycin, depurination of modified guanine, and presumably subsequent hydrolysis of the phosphate ester backbone at the resultant apurinic sites.     

O2- generation and lipid peroxidation during the oxidation of a glycated polypeptide, glycated polylysine, in the presence of iron-ADP

Oxidation of glycated polylysine, a model compound of glycated protein, caused O2- production even at physiological pH, which could be accelerated by Fe3(+)-ADP. An enediol structure in glycated polylysine and related compounds, which could be confirmed by I2 uptake, was related to their oxidizability. Glycated polylysine was easily coordinated with Fe3+ even in the presence of phosphate at pH 7.4 and the formation of the iron complex was prevented by desferrioxamine. The exposure of unsaturated phospholipid liposomes to glycated polylysine-Fe3(+)-ADP system caused the production of a thiobarbituric acid-reacting substance, which was completely inhibited by 5 microM alpha-tocopherol or 150 microM desferrioxamine and slightly by 0.5 microM SOD. Catalase (20 micrograms/ml) and 10 mM sodium-benzoate did not affect the iron-glycated polylysine-induced lipid peroxidation, indicating no participation of an OH. in this reaction. A ferrous ion-coordinated glycated polylysine may act as an initiator of phospholipid peroxidation in the presence of oxygen. A possible mechanism of the iron-glycated polylysine-induced lipid peroxidation was discussed.