Singapore, April 8, 2008: Researchers at the Bioprocessing Technology Institute (BTI), a member of the Agency for Science, Technology and Research (A*STAR) in Singapore have developed a monoclonal antibody that is able to specifically target undifferentiated human embryonic stem cells (hESCs) and cause them to undergo induced cell death. The findings were published online in the journal Stem Cells.

 

When the scientists added the monoclonal antibody, mAb 84, to laboratory cultures of hESCs, it specifically eliminated undifferentiated cells within 30 minutes but left differentiated cells untouched.

 

Dr Andre Choo, senior scientist, BTI said, “Some people find it strange why we want to develop antibodies to kill off stem cells. Indeed, stem cells are pluripotent but what is less known about them is that the very same cells can cause teratoma formations. The antibody, mAb 84 can be used before transplantation to remove any residual undifferentiated cells and therefore reduce the risk of teratoma formation. This will help address safety concerns when clinical approval for stem cell therapies is required in the future.”

 

Stem cells are well known for their ability to differentiate into virtually any type of cell, given the correct growth signals. However, stem cells that fail to differentiate can form cancerous growths called teratomas. Studies have shown that even as little as two residual undifferentiated stem cells can cause teratoma (a tumor derived from more than one embryonic layer and made up of a heterogeneous mixture of tissues) formation.

 

Prof Miranda Yap, Executive Director of BTI said, “The work done by Andre’s team has helped reinforce BTI as a leader in biologics development. It is a significant step for preclinical stem cell therapy applications. We are actively seeking collaboration with other stem cell researchers to further explore possible applications and exploit the therapeutic potential behind it.”

 

The team is working on to determine the molecular mechanisms behind the process of cell killing. In the laboratory, the researchers also are investigating potential therapeutic applications of mAb 84. BTI also is collaborating with Raven Biotechnologies, a California-based company that specializes in antibody therapeutics, to further generate novel antibodies to further the research.