The Extract of Leonurus sibiricus Transgenic Roots with AtPAP1 Transcriptional Factor Induces Apoptosis via DNA Damage and Down Regulation of Selected Epigenetic Factors in Human Cancer Cells

The aim of this study was to determine the anticancer potential of Leonurus sibiricus extract derived from in vitro transgenic roots transformed by Agrobacetrium rhizogenes with AtPAP1 transcriptional factor, and that of transformed roots without construct, on grade IV human glioma cells and the U87MG cell line, and attempt to characterize the mechanism involved in this process. The anticancer effect induced by the tested extracts was associated with DNA damage, PARP cleavage/increased H2A.X histone levels and UHRF-1/DNMT1 down-regulation of mRNA levels. Additionally, we demonstrated differences in the content of compounds in the tested extracts by HPLC analysis with ATPAP1 construct and without. Both the tested extracts showed anticancer properties and the better results were observed for AtPAP1 with transcriptional factor root extract; this effect could be ascribed to the presence of higher condensed phenolic acids such as neochlorogenic acid, chlorogenic acids, ferulic acid, caffeic acid and p-coumaric acid. Further studies with AtPAP1 (with the transcriptional factor from Arabidopisi thaliana) root extract which showed better activities in combination with anticancer drugs are needed.