Scientists find new way to detect abnormal stem cells

Melbourne scientists have identified a new method of detecting abnormal embryonic stem (ES) cells before they change into cancerous cells.

The potential of ES cells to create healthy normal tissue to repair or replace diseased tissues or organs rests in their ability to turn into any cell type. While ES cells can be grown indefinitely in the lab, after prolonged cultivation some embryonic stem cells will develop serious genetic abnormalities.

"The worry is that some of these abnormalities are similar to those that are seen in cancer cells," said Prof Martin Pera, director of the Embryonic Stem Cell Program at the Australian Stem Cell Centre (ASCC), who initiated work on these abnormal cells. "This would clearly be a problem if one were going to inject cells derived from stem cells into patients."

In a paper published online today in international journal Nature Biotechnology, co-authors Dr Ernst Wolvetang and Daniella Herszfeld, from the Monash Institute of Medical Research (MIMR) and the ASCC, reported on a new way of monitoring and studying the genetic health of stem cell cultures.

The paper outlines how the abnormal cells carry a marker molecule on their surface called CD30. It also appears that the marker gives the abnormal cells a survival advantage allowing them to grow in sub-optimal conditions.

"The cell surface receptor CD30 has a very old history in the cancer field," said Pera. "It's been known for many years as a surface marker of abnormal lymphoid cells in lymphomas. There are therefore a whole range of monoclonal antibodies that we can include to detect this marker, in addition to the modern genetic approaches such as RT-PCR analysis."

In the past abnormalities in ES cells have been difficult to monitor because of low throughput, slow and expensive techniques.

The discovery will potentially allow abnormal cells to be eliminated from cultures or could be used to test new growth conditions to see whether they induce these cell abnormalities, said Pera.

"The finding we have reported gives us a new way of monitoring and studying the genetic health of stem cells cultures," said Pera. "We think this will in turn enable us to improve methods for propagation of stem cells in the normal genetic state on a large scale."

The CD30 project is a collaborative research effort between the ASCC, MIMR, Monash University and research groups in the Netherlands, Israel and the US.