Survivin is the cause of tumor formation during embryonic stem cell therapy
Embryonic stem cells (ESCs) are pluripotent, that is, theoretically capable of differentiating into any cells of an adult organism. This property, along with the ability to remain undifferentiated in cell culture conditions, gives them the potential of an unparalleled therapeutic tool in the treatment of many diseases, from diabetes and Parkinson's disease to heart attack.
A serious obstacle to the use of ESCs is that after transplantation into the body of laboratory animals, these cells often degenerate and form tumors known as teratomas. The development of such tumors is to some extent a mystery, since at the initial stage ESCs are completely normal and have no signs of cancer cells. A group of researchers from the Silberman Institute of Natural Sciences at the Hebrew University in Jerusalem is working on ways to solve this problem.
In the last of the projects, they analyzed the genetic basis of the transformation of ESCs into tumor cells and discovered a key gene for this process. The protein survivin ("survivor") is synthesized in the cells of most types of cancer and in embryos at an early stage of development, but it does not manifest itself at all in normal tissues. A particularly high level of expression of the corresponding gene (BIRC5 – one of the members of the family of apoptosis inhibitor genes) is observed in undifferentiated ESCs and teratomas formed by them. The authors of the work showed that when the expression of survivin is stopped, ESC and teratoma cells embark on the path of programmed cell death – apoptosis.
Inhibition of survivin synthesis immediately before or immediately after ESC transplantation could minimize the risk of tumor development. The researchers suggest that it may be necessary to develop a comprehensive strategy for such a procedure in order to reduce the risk to the patient.
Portal "Eternal youth" www.vechnayamolodost.ru based on EurekAlert: Hebrew University researchers neutralize tumor growth in embryonic stem cell therapy07.05.2009