Treatment with a polyamine analog alters DNA-matrix association in HeLa cell nuclei: A nucleoid halo assay

Abstract

The polyamine analog 1,14-bis(ethylamino)-5,10-diazatetradecane (BE-4-4-4) depletes polyamines and inhibits the growth of tumor cells in tissue culture. We treated HeLa cells in culture with BE-4-4-4 for different time periods to produce different degrees of polyamine depletion. The cells were lysed and dehistonized to obtain nucleoids containing DNA attached to the nuclear matrix. Titration of the nucleoids with propidium iodide caused an uncoiling of negatively supercoiled DNA, resulting in the formation of a halo surrounding the nucleoid periphery. The halo diameters in both the BE-4-4-4-treated cells and the untreated control cells were measured using a fluorescence image analysis system. As compared to the control cells, the BE-4-4-4-treated cells showed a 20-25% decrease in halo diameter, indicating that there was less relaxation of the negative supercoils in the nuclear DNA of the BE-4-4-4-treated cells than in the controls.

A perspective of polyamine metabolism

“…Selectivity of polyamine binding to secondary structures of DNA has been suggested from crystallographic studies with polyamines having a preference for pyrimidine residues, particularly thymidine, although this may be influenced by the neighbouring nucleotides and the nature of the secondary structure [9]. Polyamine analogues such as bis(ethyl)homospermine ('BEHSpm'; 'BE-4-4-4') have been shown to alter the DNA-nuclear matrix interaction, suggesting that not only do polyamines alter the structure of DNA, but they also influence its function [10]. In the nucleosome, polyamine depletion results in partial unwinding of DNA and unmasking of sequences previously buried in the particle.…”

Chemical Features of the Protein Kinase CK2 Polyamine Binding Site,

“…Nevertheless, interaction of polybasic compounds with nucleic acids has been analyzed by a number of groups. Spermine analogs that differ in the number of methylenes separating the positively charged amino and imino groups have been successfully used to investigate the effect of polyamines on the DNA structure (Basu et al, 1989(Basu et al, , 1992(Basu et al, , 1993Edwards et al, 1991;Delcros et al, 1993;Thomas & Thomas, 1993;Garriga et al, 1993). The ionic charge, pH, and ionic concentration of the medium are parameters that govern the interaction of polyamines with the duplex DNA.…”

Regioselective binding of spermine, N¹,N12-bismethylspermine, and N¹,N12-bisethylspermine to tRNA Phe as revealed by 750 MHz ¹H-NMR and its possible correlation with cell cycling and cytotoxicity

“…These results suggest that the antineoplastic effects of the N α ,N ω -bisalkyl derivatives of spermine could be due, at least in part, to their effects on the protein synthesis process of the cell cycle rather than on the DNA replication process. The latter appears to be more affected by the N α ,N ω -bisethyl derivatives of the higher homologs of spermine 15 . ) formed the weaker bonds.…”