CD133 on Lung Cancer Stem Cells

Rome, Italy -

The targeting of drugs to tumors has historically been a difficult task for reasons such as poor vasculature and high interstitial pressure. More recent studies have described that not all tumor cells in a tumor mass are the same. Specifically some cells in the tumor mass have very high proliferative and self-renewal potential whereas others do not. These cells, which some call "tumor stem cells" resemble stem cells based on numerous properties. Such tumor stem cells were previously detected in colon cancer. Cancer stem cells are generally considered to be chemoresistant.

However, the concept of the cancer stem cell is not new. Here is a patent that has a priority date in 1978 that describes bioassays for detection of cancer stem cells.

In a recent paper (Eramo et al. Identification and expansion of the tumorigenic lung cancer stem cell population. Cell Death Differ. 2007 Nov 30) investigators have examined cancer stem cells in the condition of lung cancer. The investigators found both in small cell and non-small cell types of lung cancer that CD133 expression is associated with cells containing "stem cell" properties.

It was demonstrated that lung cancer CD133 positive cells can be maintained in serum-free medium and grown as tumor spheres. The serum-free medium needs, however, to be supplemented with EGF and FGF-2.

As little as 10,000 CD133 cells are capable of inducing tumors in immune deficient mice.

This paper thus sets up a framework for investigating the "cancer stem cell" in the lung cancer system.