linker histones/DNA interactions anticancer antibiotics chi-square test
Institute of Mathematics and Informatics Bulgarian Academy of Sciences
Pliska Studia Mathematica Bulgarica, Vol. 17, No 1, (2005), 337p-348p
Linker histones (H1, H1o H5, subtypes and variants) play a pivotal role in formation of higher order chromatin structure and thus - as main regulators of the expression of genetic information kept in DNA. That is why the knowledge of the nature of linker histones/DNA interactions is of a greatest interest in understanding of such important issues as transcription regulation, cell division, and cancerogenesis. As DNA is a main "target" of most anticancer antibiotics, the analysis of competitive reactions between that drugs (in our case actinomycin D and netropsin) and linker histones for binding to certain sites in DNA gives hopeful information concerning the mode of such interactions. In this work we present statistical analysis of some experimental data concerning the influence of some anticancer antibiotics on linker histones/DNA interactions. First, it was investigated the formulated hypothesis of the dependence of H1/DNA interaction on actinomycin D concentration. Such a relation was expected knowing the different mode for binding of the both drugs to DNA double helix. The applied statistical analysis using chi-square test for independence showed that the concentration of Actinomycin D in reaction mixture had no essential effect on linker histone/DNA binding. On the contrary, the same analysis with the second antibiotic - netropsin showed that we could not reject the hypothesis of dependence. Some other statistical models are also proposed, applying chi-square test for homogeneity, test of Willcockson, Smirnov's test and others.