Immortal DNA strand cosegregation requires p53/IMPDH-dependent asymmetric self-renewal associated with adult stem cells.

Because they are long-lived and cycle continuously, adult stem cells (ASCs) are predicted as the most common precursor for cancers in adult mammalian tissues. Two unique attributes have been proposed to restrict the carcinogenic potential of ASCs. These are asymmetric self-renewal that limits their number and immortal DNA strand cosegregation that limits their accumulation of mutations due to DNA replication errors.

Generation of hepatocyte-like cells from human embryonic stem cells.

Use of human hepatocytes for therapeutic and drug discovery applications is hampered by limited tissue source and the inability of hepatocytes to proliferate and maintain function long term in vitro. Human embryonic stem (hES) cells are immortal and pluripotent and may provide a cell source for functional human hepatocytes. We report here that hES cells can be induced to differentiate into hepatocyte-like cells.

Cellular Senescence: Ex Vivo p53-Dependent Asymmetric Cell Kinetics.

Although senescence is a defining property of euploid mammalian cells, its physiologic basis remains obscure. Previously, cell kinetics properties of normal tissue cells have not been considered in models for senescence. We now provide evidence that senescence is in fact the natural consequence of normal in vivo somatic stem cell kinetics extended in culture.

In vitro differentiation capacity of telomerase immortalized human RPE cells.

Purpose: To investigate conditions promoting the differentiation of cultured human retinal pigment epithelial (RPE) cells and assess the differentiation potential of telomerase-immortalized RPE cells.

Methods: Serially passaged RPE 340 (parental) cells have limited replicative ability and senesce after 50 to 60 population doublings (PD)s. RPE 340 cells transfected with the catalytic component of human telomerase (hTERT) have an extended lifespan.