Cytotoxic activity of 3-nitropyrazolo[5,1-c][1,2,4]benzotriazine derivatives: a new series of anti-proliferative agents.
We report the synthesis and biological evaluation of a new series of 3-nitropyrazolo[5,1-c][1,2,4]benzotriazine derivatives (compounds 1-4) bearing appropriate substitutions in positions 7 and/or 8. The objective of this investigation was to study the effects of these substitutions on the cytotoxic activity of four new compounds against established human cancer cell lines (i.e. HT29 and HCT-8, colon carcinoma, MCF7, breast carcinoma, and A549, lung carcinoma cells). The inhibitory effects of compounds 1-4 on cell growth were assessed by the sulforhodamine B assay. Also, the effects of these compounds on cell cycle distribution of human colon carcinoma cells (HCT-8) were analyzed by flow cytometry. 3-Nitropyrazolo[5,1-c][1,2,4]benzotriazine derivatives displayed IC(50) values in the micromolar range on the growth of the four cell lines tested. Cell cycle perturbations induced on HCT-8 cells by study compounds at the IC(50) values consisted prevalently of a slight accumulation of cells in G(0)/G(1) phase and a slight decrease in G(2)/M phase. However, compound 3 induced a marked accumulation of cells into S phase with concomitant decrease in G(0)/G(1) and G(2)/M phases. Cytotoxicity data, compared to those obtained with 3-cyano-8-chloropyrazolo[5,1-c][1,2,4]benzotriazine 5-oxide (compound 5, NSC 683334) and other compounds previously synthesized in our laboratory, demonstrated a similar or even improved cytotoxic potency. Cell cycle perturbations caused by these compounds support the hypothesis that they may act by a direct or an indirect inhibition of DNA synthesis.
Coronnello
Marcella
M
Department of Preclinical and Clinical Pharmacology, University of Florence, Italy. marcella.coronnello@unifi.it
Ciciani
Giovanna
G
Mini
Enrico
E
Guerrini
Gabriella
G
Caciagli
Barbara
B
Selleri
Silvia
S
Costanzo
Annarella
A
Mazzei
Teresita
T
D000970:Antineoplastic Agents / Q000494:pharmacology*; D001943:Breast Neoplasms; D002453:Cell Cycle / Q000187:drug effects*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D003110:Colonic Neoplasms; D004354:Drug Screening Assays, Antitumor; D019073:HT29 Cells; D006801:Humans; D008175:Lung Neoplasms; D011720:Pyrazoles / Q000494:pharmacology*; D014227:Triazines / Q000494:pharmacology*
D000970:Antineoplastic Agents; D011720:Pyrazoles; D014227:Triazines; C043058:3-nitropyrazole