Teiko Hasegawa

Isothiocyanates inhibit cell cycle progression of Hela cells at G2/m phase

To analyze the inhibitory effects of isothiocyanates on the growth of human cancer cells, the effects of these compounds on the cell cycle progression of HeLa cells were studied by flow cytometry. The accumulation of cells at G2/M phase was observed at 16 h after treatment with 10 microM allyl isothiocyanate, 2.5 microM benzyl or phenethyl isothiocyanate, at which concentrations the cell growth was inhibited to 41-79% of control. These results suggest that isothiocyanates delay the cell cycle progression of HeLa cells, leading to inhibition of cell growth.

Anti-tumor-promoting activity of derivatives of abieslactone, a natural triterpenoid isolated from several Abies genus.

Abiesenonic acid methyl ester (AVB-I acid methyl ester), a triterpenoid compound prepared from abieslactone, suppressed tumor promoter-induced phenomena in vitro and in vivo; i.e., AVB-I acid methyl ester inhibited 12-o-tetradecanoylphorbol-13-acetate (TPA)-stimulated 32Pi-incorporation into phospholipids of cultured cells and the promoting action of TPA on skin tumor formation in mice initiated with 7,12-dimethylbenz[a]anthracene.

Anti-Tumor and Anti-Tumor Promoting Activity of α- and β-Carotene

Carotenoids are known to inactivate certain reactive oxygen species, such as singlet oxygen. Since antioxidants have been suggested to be one of the promising agents for cancer control, it is worthwhile to evaluate the anti-cancer potency of these carotenoids.

Effects of vanadate on intracellular Ca2+ redistribution and hexose transport across plasma membrane in cultured mouse fibroblasts

The effects of vanadate on intracellular Ca2+ sequestration and hexose transport were studied in Swiss 3T3 cells. Vanadate inhibited ATP‐dependent Ca2+ uptake by saponin‐permeabilized Swiss 3T3 cells at 10−5 and 10−7M Ca2+ at which the Ca2+ uptake was sensitive and insensitive to oligomycin plus antimycin A, respectively. On the other hand, vanadate stimulated 2‐deoxy‐D‐glucose (2DG) uptake in a dose‐ and time‐dependent way. The stimulation of 2DG uptake by vanadate was inhibited by EGTA plus A23187 and the inhibition was reversed by Ca2+ restoration. These results suggest that an increase in cytosolic Ca2+ by inhibition of intracellular ATP‐dependent Ca2+ sequestration by vanadate results in the stimulation of hexose transport in Swiss 3T3 cells.