p53 – A guardian angel in regulating normal and cancer stem cell states

The p53 is a tumor suppressing proteins that activates DNA repair proteins and apoptosis pathways in response to DNA damages that are not irreparable. Mutations in p53, which affects its activity, are responsible for developing various cancers; 83% of tumors have alterations or defect in p53 (1). The p53 plays crucial role in embryonic stem (ES) cells. p53 represses the expression of Nanog, a transcription that is critical for the self-renewal of ES cells (2). Loss of p53 reduces spontaneous differentiation and apoptosis in human embryonic stem cells (3). It has been proposed that breast cancer tumors can originate from cancer stem cells or cancer cells become stem cells due to p53 deficiency, which favors the expansion of cancer stem cells (4). Recent reports (shown below in boxes) have shown the importance of p53 in various stem cell states. Independent studies from five laboratories have shown that loss ofp53 is needed for the induction of induced pluripotent stem cells (iPS cells) from adult cells (see thumbnails). The role of p53 in cancer stem cells has been shown by a recent study . This study has shown that loss of p53 induces symmetric cell division in breast cancer stem cells and this favors breast cancer tumor growth. Read more: http://www.sciclips.com/sciclips/blogMain.do