Synthesis and biological activities of 7-aza rebeccamycin analogues bearing the sugar moiety on the nitrogen of the pyridine ring.

The synthesis of a new family of 7-aza-rebeccamycin analogues in which the sugar moiety is attached to the nitrogen of the pyridine ring is described. The capacity of the newly synthesized compounds to bind to DNA and to inhibit topoisomerase I has been evaluated. Their cytotoxicities toward four tumor cell lines, one murine leukemia L1210 and three human tumor cell lines, one prostate carcinoma DU145, one colon carcinoma HT29, and one non-small cell lung carcinoma A549, have been determined. Their abilities to inhibit the checkpoint kinase Chk1 have been evaluated

Synthesis and biological evaluation of novel naphthocarbazoles as potential anticancer agents.

We report the efficient synthesis involving palladium-catalyzed reactions and biological evaluation of new naphthocarbazoles designed as potential anticancer agents. The use of 5- and 6-benzyloxyindoles generated three substitution sites which were successively exploited to introduce several hydrophilic side chains. The cytotoxicity of the newly designed compounds was evaluated on three cell lines. Several compounds showed a marked cytotoxicity with IC(50) values in the sub-micromolar range. This is the case for the 3-hydroxy-naphthopyrrolocarbazoledione 37, bearing a dimethylaminoethyl side chain, which is extremely cytotoxic to L1210 and DU145 cells (IC(50): 36 nM, 108 nM) and induces an accumulation of L1210 cells in the G2+M phases of the cell cycle. Some of the most cytotoxic compounds were tested for inhibition of CDK-5, GSK-3 and topoisomerase I, and their interaction with DNA was also evaluated. Interaction with DNA was detected, suggesting that nucleic acids represent a privileged target for these molecules

Cells derived from regenerated endothelium of the porcine coronary artery contain more oxidized forms of apolipoprotein-B-100 without a modification in the uptake of oxidized LDL

Increased accumulation of lipoproteins and cholesterol within cells from regenerated endothelium may be responsible for their reported dysfunction. This study compared the presence and uptake of oxidized forms of low-density lipoprotein (LDL) in cells derived from native and regenerated endothelium. Four weeks after balloon denudation, primary cultures of native and regenerated endothelial cells were prepared from porcine coronary arteries. Regenerated endothelium stained more strongly using an antibody against oxidized lipoproteins. The increase in oxidized forms of apolipoprotein-B-100 exhibited by cells from regenerated endothelium was not due to an increase in extracellular-induced oxidation of native LDL, measured as the production of thiobarbituric-acid-reactive substances, being identical in both cell types. Intracellular cholesterol and cholesterol ester content were unchanged in regenerated cells. Using flow cytometry, accumulation of oxidized LDL was investigated further by quantifying the uptake of a mildly oxidized preparation of 1,1’-dioctadecyl-3,3,3’,3-tetramethyl-indocarbocyanine perchlorate-labelled LDL. The parameters of uptake, EC50 and Emax, were not different between cells from native and regenerated endothelium suggesting that the number of LOX-1 receptors was identical in the two cell types. Moreover, a negative correlation between the increased uptake of acetylated LDL and decreased cGMP production in response to bradykinin was observed in cells from regenerated endothelium. Thus, the increased incorporation of modified LDL and their intracellular oxidation could be responsible for the alteration in NO production. The presence of oxidized forms of LDL may be a marker of endothelium regeneration and could be involved in the endothelial dysfunction of pig coronary arteries 4 weeks after balloon denudation