H2O2 inhibits BCR-dependent immediate early induction of EBV genes in Burkitt's lymphoma cells.

The critical step in the Epstein-Barr virus (EBV) transition from latency to lytic replication is activation of the viral immediate early (IE) genes, BZLF1 and BRLF1. Their induction in Burkitt's lymphoma Akata cells is directly targeted by B cell receptor (BCR) signaling. On the other hand, BCR stimulation causes an outwardly directed superoxide (O(2)(*-)) burst leading to massive generation of reactive oxygen species in the cell environment.

Resveratrol-induced modification of polyamine metabolism is accompanied by induction of c-Fos.

The objective of the current study was to investigate the effect of resveratrol, a naturally occurring polyphenol with cancer chemopreventive properties, on polyamine metabolism in the human colonic adenocarcinoma cell line Caco-2. We demonstrated that inhibition of ornithine decarboxylase (ODC), the rate-limiting enzyme in polyamine biosynthesis, was due to attenuated ODC protein and mRNA levels (50-200 microM). The naturally occurring resveratrol analog piceatannol (100 microM) also diminished ODC activity, protein and mRNA levels, whereas the green tea polyphenol (-)-epigallocatechin gallate (EGCG; 100 microM) exerted only weak effects on ODC.

Insufficiently charged isosteric analogue of spermine: interaction with polyamine uptake, and effect on Caco-2 cell growth.

We characterised a novel, charge-insufficient isosteric analogue of spermine, 11-[(amino)oxy]-4,9-diaza-1-aminoundecane (AOSPM). This analogue was synthesised by displacing aminopropyl group by aminooxyethyl group, the latter having pK(a) of about 5. Charge deficiency of the AOSPM molecule was fixed at a definite atom, while pK(a) of the rest nitrogen was similar to the parent polyamine.