p53 is required for etoposide-induced apoptosis of human embryonic stem cells
C Grandela, MF Pera, EJ Wolvetang
STEM CELL RESEARCH | ELSEVIER SCIENCE BV | Published : 2008
The molecular mechanisms controlling DNA-damage-induced apoptosis of human embryonic stem cells (hESC) are poorly understood. Here we investigate the role of p53 in etoposide-induced apoptosis. We show that p53 is constitutively expressed at high levels in the cytoplasm of hESC. Etoposide treatment results in a rapid and extensive induction of apoptosis and leads to a further increase in p53 and PUMA expression as well as Bax processing. p53 both translocates to the nucleus and associates with the mitochondria, accompanied by colocalization of Bax with Mcl1. hESC stably transduced with p53 shRNA display 80% reduction of endogenous p53 and exhibit an 80% reduction in etoposide-induced apoptos..View full abstract
We thank Irene Tellis, Karen Koh, and Linh Nguyen (Monash University) and Pegah Jamshidi, Lisa Kass, and Tracy Lomas (ASCC) for expert technical assistance in hESC cell line culture; Andrew Fryga (ASCC) for discussion on flow cytometry; Ygal Haupt for helpful discussion and suggestions; Joe Sambrook for critically reading the manuscript; George Thouas for cyclosporin and CCCP; and Joao Ramalho-Santos for facilitating this research. We greatly acknowledge Sean Grimmond and Gabriel Kolle for their transcriptome and bioinformatic analyses. This work was supported partially by the Fundacao para a Ciencia e a Tecnologia, Portugal, and Catarina Grandela is a recipient of a Ph.D. fellowship from the Fundacao para a Ciencia e Tecnologia (Portugal). The ASCC is greatly acknowledged for financial and material support.