A nucleoside kinase has been purified about 1680-fold from L1210 leukemia cells with deoxyadenosine as the phosphate acceptor and with adenosine triphosphate as phosphate donor. The molecular weight of the enzyme, determined by Sephadex G-200 column chromatography, was found to be about 100,000. Purified enzyme, after the final step of purification and also after disc gel electrophoresis (Rf 0....

Apoptosis ¡sa morphologically and biochemically distinct form of cell death that occurs under a variety of physiological and pathological con ditions. In the present study, the proteolytic cleavage of poly(ADP-ribose) polymerase (pADPRp) during the course of chemotherapy-induced apoptosis was examined. Treatment of HL-60 human leukemia cells with the topoisomerase H-directed anticancer agent e...

The modulation of donai growth of cells of 15 human lung cancer lines was examined by coculture with different recombinant lymphokines, monokines, and several agents which induce differentiation in other malignant cell systems. Recombinant human tumor necrosis factor a (TNF) was inhibitory to all non-small cell lung cancer cell lines with a 50% effective dose of donai inhibition (EDM) in the ra...

Infection of the bone marrow-derived mast cell line PB-3c with a retrovirus carrying oncogenic c-Ha-rai or v-Ha-ras reduced the interleukin 3 (IL-3) growth requirement and induced a state of tumorigenicity. In contrast, normal c-Ha-ruîhad no effect on the IL-3 requirement of this cell line nor did the cells become tumorigenic. A factor reduction similar to that caused by activated lin-ras was ...

Examples of substances reported to stimulate liver growth are few. Coramine (nikethamide, or diethylnicotinamide) causes an increase in the absolute, fat-free weight of the liver of the young rat and would appear to qualify as one of these. The effect was first noted by Coulson and Brazda in 1947 (5) in 45-50-gm. rats fed 1.0 per cent levels of Coramine in a high protein diet. It was an un expe...

Greenstein in 1942 found a high content of alka line phosphatase in transplanted rat hepatoma 31 (3). This tumor arose originally in the liver of a male Osborne-Mendel rat and was induced by the basal diet of White and Jackson (16) containing 0.06 percent />-diinethylaniinoazobenzene (DAB) with intermittent addition of 0.5 per cent cystine and 0.5 per cent methionine (17). The enzyme ac tivity ...

Cyclophosphamide and its isomer ifosfamide are cell cycle-nonspecific alkylating agents that undergo bioactivation catalyzed by liver cytochrome P-450 enzymes. The therapeutic efficacy of these oxazaphosphorine anticancer drugs is limited by host toxicity resulting from the sys temic distribution of activated drug metabolites formed in the liver. Since tumor cells ordinarily do not have the cap...

The effect of four different retinoids [retinol, 13-c/s-retinoic acid (Ro4-3780), /8-all-irans-retinoic acid, and aromatic retinoie acid ethyl ester (Ro10-9359)] on the cellular proliferation (cell number) and biochemical differentiation (tyrosinase activ ity) of a human melanoma cell line (MIRW) and three subclones was assessed. All four retinoids (10~6 M) inhibited the cellular proliferation ...

Hydroxyurea inhibits cellular proliferation through action on ribonucleotide reducÃ-ase,an iron-dependent enzyme responsible for the synthesis of deoxyribonucleotides. Whereas previous investigations have examined the interaction of hydroxyurea with this enzyme, the action of hydroxyurea on other aspects of iron metabolism has not been studied in detail. In our study, incubation of CCRF-CEM cel...

Apoptosis ¡sa morphologically and biochemically distinct form of cell death that occurs under a variety of physiological and pathological con ditions. In the present study, the proteolytic cleavage of poly(ADP-ribose) polymerase (pADPRp) during the course of chemotherapy-induced apoptosis was examined. Treatment of HL-60 human leukemia cells with the topoisomerase H-directed anticancer agent e...