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Biomedical subjects

L Capolongo

Publications and source records attributed to L Capolongo.

6 recordsLinked to original sources

Purine and 1-deazapurine ribonucleosides and deoxyribonucleosides: synthesis and biological activity.

A series of 6-(hydroxylamino)purine and -1-deazapurine nucleosides were synthesized and tested for their antitumor and adenosine deaminase inhibitory activity. All the examined molecules displayed an in vitro activity comparable to that of the reference compounds 6-(hydroxylamino)-9-beta-D-ribofuranosylpurine (HAPR) and ara-A, their ID50 ranging from 0.9 microM to approximately 100 microM. The 6-hydroxylamino derivatives of 1-deazapurine 9, 12, and 17 and also the blocked compound 13 are inhibitors of ADA whereas the purine derivatives 4 and 6 and the nitro compounds 11 and 16 are resistant to the enzyme. 7-(Hydroxylamino)-3-(2-deoxy-beta-D-erythro-pentofuranosyl)-3H-imi dazo[4,5- b]pyridine, the less cytotoxic but the most active ADA inhibitor in the series (Ki = 2.7 x 10(-7)), greatly potentiates the antitumor activity of ara-A in vitro.

Adenosine Deaminase Inhibitors

Biological profile of FCE 24517, a novel benzoyl mustard analogue of distamycin A.

FCE 24157 (chemically (beta-[1-methyl-4-(1-methyl-4--[1-methyl-4-(4-N,N- bis(2-chloroethyl) amino-benzene-1-carboxy-amido) pyrrole-2-carboxiamido]pyrrole-2-carboxyamido)pyrrole-2-c arboxyamido]) propionamidine, hydrochloride) is a distamycin A (Dista A) derivative bearing a benzoyl mustard moiety instead of the formyl group at the N-terminal. Contrary to Dista A, FCE 24517 has been found to display potent cytotoxic activity on human and murine tumour cell lines. The compound maintains activity on melphalan (L-PAM)-resistant cells, whereas cross-resistance is observed on doxorubicin-(DX)-resistant cells. In vivo, FCE 24517 was found to possess evident antineoplastic activity on a series of murine transplanted solid tumours and human tumour xenografts. The following neoplasms were in fact found to be sensitive to FCE 24517 treatment: M14 human melanoma xenograft, N592 human small cell lung carcinoma, MTV murine mammary carcinoma, Colon 38 murine carcinoma, PO2 murine pancreatic carcinoma and M5076 murine reticulosarcoma. Lower effectiveness was observed against the murine P388 and Gross leukaemia, Lewis lung murine carcinoma, LoVo human colon carcinoma xenografts and A459 human lung adenocarcinoma. Against the murine L1210 leukaemia, FCE 24517 displayed a clear activity only when the tumour was transplanted i.p. and treatment was given i.p., whereas only marginal activity was seen against this leukaemia if transplanted i.v. and the drug was given i.v. As true also in vitro, FCE 24517 was effective against i.p. implanted L1210 leukaemia resistant to L-PAM. The mode(s) of action of this new compound is under active investigation.

Animals

DNA damage and cytotoxicity of mitoxantrone and doxorubicin in doxorubicin-sensitive and -resistant human colon carcinoma cells.

The effects of mitoxantrone (Mx) and doxorubicin (Dx) on cytotoxicity and DNA damage as assayed by alkaline elution were studied in two human colon adenocarcinoma cell lines sensitive (LoVo) and resistant (LoVo/Dx) to doxorubicin. Mx was more cytotoxic than Dx to LoVo cells and was partially cross-resistant in LoVo/Dx. In LoVo cells, Mx produced about 5 times more DNA single-strand breaks (DNA-SSB) than Dx, but both drugs caused an equal number of DNA double-strand breaks (DNA-DSB). In LoVo/Dx cells, the number of DNA-DSB was very low for both Dx and Mx, but DNA-SSB were about 20 times higher for Mx. In LoVo cells, the number of DNA-DSB and protein-associated SSB were similar at equitoxic concentrations. For LoVo/Dx, the partial cross-resistance of Mx might be explained by the much higher number of DNA-SSB produced by this drug.

Colonic Neoplasms

Representing cell cycle data.

In this communication we suggest two simple ways to represent the information on the cell cycle obtained by flow cytometry, offering some advantages over the traditional plots. We show that the results of a single experiment, when reduced to the percentages of cells in G1, S, and G2M phases, can be completely expressed with a single point in a G1-G2 plan where iso-S lines are also drawn. By the use of this plot, the time course of the complete kinetics of a cell population may be shown in a single drawing. The second plot, we suggest, integrates information on cell cycle, represented by the distribution mean, with cell number.

Cell Cycle