KRAS Cancer

What am I looking at?

This image is a sample of lung tissue from a genetically engineered mouse with a mutation in the KRAS gene. The KRAS-driven cancer cells are purple (1), while the dark areas represent normal, noncancerous lung tissue (2).

Biology in the background

The KRAS gene is responsible for producing a protein also called KRAS that’s involved in regulating the entrance of signaling molecules into the nucleus of a cell. Many of the nuclear signaling molecules that the KRAS protein regulates are part of the pathway that initiates cell division. When the KRAS protein is nonfunctional or absent, there is an increase in nuclear signaling that results in an increase in cell division, turning these cells cancerous.

You can think of the KRAS protein as the brake pedal on a car. It is partially responsible for regulating the “speed” of cell division. If the brake pedal is no longer functional, the cell is not able to slow down the process of cell division, and the cell starts dividing in an uncontrolled manner.

Genetically engineered mice with a mutation in the KRAS gene are very useful in studying KRAS-driven cancers because they allow researchers to observe the development and spread of such cancers. This information is helpful in generating new therapies for the treatment of KRAS-driven cancers in humans.

In mice and humans alike, these cancer cells can grow up to 25 micrometers across, or roughly three times smaller than the width of a human hair.

Technique

This image was created using confocal microscopy and then processed to make the edges of the cells more distinct.