Genotoxicity of Novel Pyrazolo[4,3-e]tetrazolo[1,5-b][1,2,4]triazine Sulfonamides in Normal and Cancer Cells In Vitro

Abstract

Pyrazolo[4,3-e]tetrazolo[1,5-b][1,2,4]triazine sulfonamides constitute a novel group of heterocyclic compounds with broad biological activities including anticancer properties. The compounds investigated in this study (MM134, -6, -7, and 9) were found to have antiproliferative activity against BxPC-3 and PC-3 cancer cell lines in micromolar concentrations (IC50 0.11–0.33 µM). Here, we studied the genotoxic potential of the tested compounds with alkaline and neutral comet assays, accompanied by immunocytochemical detection of phosphorylated γH2AX. We found that pyrazolo[4,3-e]tetrazolo[1,5-b][1,2,4]triazine sulfonamides induce significant levels of DNA damage in BxPC-3 and PC-3 cells without causing genotoxic effects in normal human lung fibroblasts (WI-38) when used in their respective IC50 concentrations (except for MM134) and showed a dose-dependent increase in DNA damage following 24 h incubation of tested cancer cells with these agents. Furthermore, the influence of MM compounds on DNA damage response (DDR) factors was assessed using molecular docking and molecular dynamics simulation.

Pyrazolo[4,3-e]tetrazolo[1,5-b][1,2,4]triazine Sulfonamides as an Important Scaffold for Anticancer Drug Discovery—In Vitro and In Silico Evaluation

“…In the initial in silico research, we performed molecular docking and molecular dynamics studies of the previously studied MM129 compound and the compounds investigated in the present work ( MM134 , -6 , -7 , and -9 ). We found that compounds may inhibit the molecular targets to a similar or greater extent than previously investigated MM -compounds (including MM129 ) [ 8 , 11 ]. However, these results were established with the use of single molecular docking and dynamics software.…”

“…The genotoxic activity of the compounds in the comet assay and γH2AX staining was also described. Furthermore, it was indicated that the DNA-damaging capability of the compounds may be attributed to the inhibition of CHK1 kinase, as indicated by in silico results [ 8 , 11 ]. Furthermore, these compounds exhibited profound pro-apoptotic activity in the BxPC-3 cell line following 24 and 48 h incubation of cells in vitro, where 2xIC 50 concentrations of all MM -compounds induced apoptosis of 68.1 ± 7.33% to 95.1 ± 1.48% of the cells [ 11 ].…”

“…The exposed cell can be negative for the sub-G1 peak, as DNA fragments are still retained in the nucleus [ 15 ]. Moreover, the presence of DNA strand breaks following incubation with MM -compounds was confirmed through the alkaline/neutral comet assay and γ-H2AX staining [ 7 , 8 ]. To further explore apoptosis induction, we performed a DNA fragmentation assay.…”

“…These MM -compounds exhibit cytotoxic and genotoxic activity in cancer cells in micromolar concentrations and show pro-apoptotic properties, as indicated by the externalization of phosphatidylserine (PS) on the outer plasma membrane of apoptotic cells, morphological changes explored with dual staining with acridine orange/ethidium bromide, and changes in the mitochondrial membrane potential (MMP; ΔΨm). These effects are selective for cancer cells compared with normal cells [ 8 , 11 ].…”

“…Many pyrazolo [4,3-e] [1,2,4]triazines have exhibited anticancer activity in vitro. Specifically, tricyclic pyrazolo [4,3-e] [1,2,4]triazines fused with a triazole or tetrazole ring have been found to possess cytotoxic and [6] and genotoxic activity [7,8] that result in the induction of apoptotic cell death [9][10][11].…”