Keratin 17: more than a biomarker for cancer

PREMISE: A new investigation from the John Hopkins University Bloomberg School of Public Health in Baltimore, Maryland, United States, suggests that the keratin 17 protein (whose presence is used to detect and classify several types of cancer) isn't only a biomarker for the illness, but also plays a critical role in cancer growth.

Keratin 17 is a protein found in healthy hair follicles (the part of the skin responsible for hair growth), nails and glands, but not in healthy epidermis (that is, it can't be found in our skin under normal conditions), and takes very high values in those cells that become cancerous or affected by other skin illnesses. It's because of this that keratin 17 was utilized as an indicator for tumors in the organism, among many other functions.
It should be noted that keratin isn't the cause of cancer, but as the author explains, it works as an accelerator: the more you step on it (that is, the higher the protein amount), the faster the illness will develop.

The question that the study's main author, Ryan P. Hobbs, asked himself was: is keratin a driver for the illness or is it just an innocent bystander? In other words, is keratin responsible in any way for the proliferation of the tumor, or is the increase in protein concentration just a signal for the fact that the cell that is being analyzed is dangerous?

The team worked with genetically modified mice so that they would produce skin cancer induced by viral HPV; in other words, by the human papillomavirus. They used this type of virus because it has been proven to be one of the most common forms of skin cancer.

When the cancers were examined in the mice after eliminating the protein, they saw a clear decrease in tumors, and thus a decrease in the inflammatory and immune response in the damaged cell. This shows clear evidence that the keratin 17 isn't just a marker as it had been being used so far, but it paricipates in an active manner in the cancerous process.

It's worth noting that the experiment was done with cancerous human cells and the results were fairly similar.

How is keratin 17 involved?

After samples from both mice and humans were analyzed, it was found out that keratin 17 moves to the nucleus of cancerous cells and is responsible for the increase in tumor-stimulating inflammation, and at the same time, the activation of damaged cells that modify their immune response, which makes our immune system unable to fight them, allowing them to proliferate out of control.

This information is revealing because up until this point it was thought that the protein worked outside of the nucleus as a component of the cytoskeleton, which gives form and function to our cells.

The authors want to point out that this is a very important find because if we were able to delay the development of cancers, this could give enough time to our immune system to do its work and eliminate the damaged cells, or allow cancer treatment to fight the illness in a more effective manner.