Experimental In Vitro Mouse and Human Stem Cell Models for Balanced Activity of Oncogenes and Tumor-Suppressor Genes

Sainova I., Vavrek I., Pavlova V., Daneva T., Iliev I., Yossifova L., Gardeva E., Nikolova E.

Abstract
Taking in consideration many literature data, according which coordinated oncogenes and tumor-suppressor genes functions is of most importance. In this connection, the main idea was balanced activity of oncogenes and tumor-suppressor genes in vitro in laboratory-cultivated normal cells be achieved. Additional copy of oncogene was inserted Dcn1 in mouse embryonic stem cells (mESCs) by their transfection with appropriate recombinant DNA-constructs. On the other hand, in cultivation of separate sub-populations of non-transfected mESCs in the presence of Doxicyclin, suppressed cell proliferation and increased myeloid cell differentiation was observed, probably by activation of genes from STAT-family. After in vitro-co-cultivation of sub-populations of transfected mESCs, containing additionally-inserted copy of oncogene Dcn1 with sub-populations of non-transfected mESCs, treated with Doxicyclin, the results obtained have indicated the safety and preserved normal/non-tumorigenic cell character of the so derived stem cells in vitro, despite of the presence of additional oncogene copy. These data were confirmed by results from similar experiments with analogical human normal trophoblast cells, immortalized by transfection with SV40 recombinant gene vector.

Key words: Stem cells, oncogenes, tumor-suppressor genes, cell transfection