RESUMO
To study the tumour-promotion activity of cell environment the transformed embryonic rat fibroblasts (clone CL-1-1) were transfect to immunodeficient mice then the cells of the formed tumour were cultivated (clone CL-1-1). The cells before and after transplantation were compared by morphology, proliferation activity and gap junction intracellular communications. The clone CL-1 cells proliferated much faster than clone CL-1 cells. The CL-1-1 cells had changed morphology structure and unlike CL-1 the contract inhibition was absent in CL-1-1. The number of CL-1 cells in phase G1 was significantly greater than that of CL-1-1 cells, while the number of CL-1-1 cells in G2/M phases was much more the number of CL-1 cells. The activity of gap junction intercellular communications in both cell types was near the same. It was concluded that cell microenvironment act as a tumour-promoter and tumour progression factor in the case of cell transplantation to immunodeficient mice.