Cancer Cells And Stem Cells Share Same Origin, Researchers Find

New research has shown that oncogenes can change normal cells into stem-like cells, paving the way to a safer and more practical approach to treating diseases like multiple sclerosis and cancer with stem cell therapy.

Oncogenes have generally been thought to be genes that, when mutated, change healthy cells into cancerous tumor cells. But, "the reality may be more complicated than people think," said Jiang F. Zhong, Ph.D., assistant professor of pathology at the Keck School of Medicine at the University of Southern California. "What is a stem cell gene? What is a cancer gene? It may be the same thing."

"When you turn off p53, people think the cell becomes cancerous because we tend to focus on the bad thing," Zhong said. "Actually, the cell becomes more plastic and could do good things, too. Let's say the cell is like a person who loses his job (the restriction of p53). He could become a criminal or he could find another job and have a positive effect on society. What pushes him one way or the other, we don't know because the environment is very complicated."

Stem cells can divide and differentiate into different types of cells in the body. In humans, embryonic stem cells differentiate into three families, or germ layers, of cells. The reasons why and how certain stem cells differentiate into particular layers are not clearly understood. However, from those layers, tissues and organs develop. The endoderm, for example, leads to formation of the stomach, colon and lungs, while the mesoderm forms blood, bone and heart tissue. In its study, Zhong's team examined human skin cells, which are related to brain and neural cells from the ectoderm.

When p53 was suppressed, the skin cells developed into cells that looked exactly like human embryonic stem cells. But, unlike other man-made stem cells that are "pluripotent" and can become any other cells in the body, these cells differentiated only into cells from the same germ layer, ectoderm.

"IPSCs [induced pluripotent stem cells] can turn into anything, so they are hard to control," Zhong said. "Our cells are staying within the ectoderm lineage."

Zhong said he expects that suppressing other oncogenes in other families of cells would have the same effect, which could have critical significance for stem cell therapy.

Adapted from the University of Southern California announcement.