Canadian scientists have discovered how to control the development of stem cells, which could one day allow researchers to repair organs damaged by disease.

Researchers with The Hospital for Sick Children in Toronto have found that by isolating and boosting the activity of one gene within a stem cell, the stem cell was likely to become the type of cell the researchers wanted.

Embryonic stem cells can become any type of cell in the human body.

The scientists conducted their research alongside colleagues from Hamilton, Ont.'s McMaster University and Toronto's Mount Sinai Hospital. The findings are published in the journal Stem Cell.

"The nice thing about embryonic stem cells is that they can make every cell type in the body. The difficult thing about embryonic stem cells is that they can make every type of cell in the body!" Dr. Janet Rossant of SickKids, one of the study's authors, told CTV News.

"And so when you push them to specialize they tend to make different cell types. We're trying to control that process and identify the genes that get the cells down a pathway, and then hold them at the start."

The researchers also found the stem cells multiply faster after their genes are manipulated.

Human embryonic stem cells are the "master" cells from which other cell types develop. Scientists believe they will play an integral role in treatments and cures for a variety of illnesses because they can become any one of the more than 200 cell types found in the human body.

However, until now, scientists have been unable to control how stem cells develop into one type of cell versus all the others.

The researchers focused on turning endothelial embryonic stem cells, which come from the outside of the embryo, into endoderm cells. These cells are the basis for the development of a variety of organs, such as the lung, liver and pancreas, as well as the digestive and respiratory tracts.

The researchers said that their findings are not yet applicable to human patients.

However, a long-term goal for scientists would be the ability to create cells to repair damage to specific organs, such as lung cells to treat the effects of lung disease.

"Our goal is to recreate what happens in the embryo, but in the dish," another of the study's authors, Dr. Cheryle Seguin, told CTV News. "And so for us this is truly a step forward in understanding what genes can control cell fate, and use them to make clinically relevant tissue."

With a report by CTV medical specialist Avis Favaro and producer Elizabeth St. Philip

Abstract:

Establishment of Endoderm Progenitors by SOX Transcription Factor Expression in Human Embryonic Stem Cells

Cheryle A. Seguin, Jonathan S. Draper, Andras Nagy and Janet Rossant

In this study, we explore endoderm cell fate regulation through the expression of lineage-determining transcription factors. We demonstrate that stable endoderm progenitors can be established from human ES cells by constitutive expression of SOX7- or SOX17-producing extraembryonic endoderm and definitive endoderm progenitors, respectively. In teratoma assays and growth factor-mediated differentiation, SOX7 cells appear restricted to the extraembryonic endoderm, and SOX17 cells demonstrate a mesendodermal phenotype in teratomas and the ability to undergo endoderm maturation in vitro in the absence of cytokine-mediated endoderm induction. These endoderm progenitor cells maintain a stable phenotype through many passages in culture, thereby providing new tools to explore the pathways of endoderm differentiation.