Chromosomal influence on hybrid cell proliferation

When normal cells and cancer cells (usually from the same species) are experimentally fused the resultant hybrid cells show loss of the tumorigenic phenotype. To examine the phenotypic phenomenon of growth suppression in hybrid cells in vitro, we examined the doubling times of somatic cell hybrids which contained single or multiple chromosomes derived from another species (inter-species hybrids). In all of the hybrid lines examined, the presence of transferred chromosomes prolonged the cell population doubling times in proportion to the number of such chromosomes found in the hybrid lines. These findings provide additional evidence to support the hypothesis that increasing the genetic burden of cells may reduce the division potential of cells cultured in vitro.