New cell type identified in cancer development

The finding may help define the role of cancer stem cells in the growth and recurrence of the disease as well as offer new options for cancer prevention, detection and treatment.

Cancer stem cells are found in tumors and are capable of creating other types of cells or tissues. However they are different to other stem cells in that injecting even as few as 100 of them into laboratory animals will cause cancer. Because they are rather unstable, they are notoriously tricky to isolate and describe, while also being resistant to virtually any kind of treatment, and some scientists believe they are the reason cancer recurs.

Until now, no one has known how cancer stem cells arise, but a team of scientists, led by Dr Jian-Xin Gao, a researcher in the department of pathology at Ohio State University Medical Center, has identified a new set of cells he calls precancerous stem cells (pCSCs).

These cells share some of the characteristics full-fledged cancer stem cells have, but they are different in that they respond to distinct cell signals that determine their ultimate fate – whether they will continue to grow into cancer or cancer stem cells, lie inactive or be eradicated by the body’s immune system.

The results of Dr Gao’s work showed that the strength of the immune system affected whether or not the mice got cancer. The scientists found that the pCSCs, like normal stem cells, had the ability to create various types of benign cells in mice with healthy or recovering immune systems. These daughter cells, however, were likely to die, especially when they encountered signals to further differentiate – a strong contrast to the behavior of normal stem cells.