Fig. 4

Electropherogram of STR analysis evaluates genetic expression in macrophages, MCF-7/GFP and macrophage/MCF-7 hybrid cells. MCF-7/macrophage hybrids were created by spontaneous fusion between M2 macrophages differentiated from monocytes harvested from male blood donors and GFP-labeled MCF-7 breast cancer cell. STR analysis with 24 markers on X and Y chromosomes and on chromosomes 13, 18 and 21 was used to determine the DNA profile and origin of the hybrid cells. The figure represents 12 of 17 shared loci detected in MCF-7/macrophage hybrids as a result of fusion between MCF-7 breast cancer cells and macrophages. The hybrids exhibit sex-determining region Y gene (SRY), which is an important indicator that these cells have arisen after fusion between macrophages and MCF-7 cells (a). MCF-7 cells from the transwell chamber system showed no shared STR loci confirming that niether cell fusion nor genetic exchange had occurred between the macrophages and MCF-7 cancer cells (b)