New insight into genomic alterations associated with telomere maintenance mechanisms in cancer
To function, proteins bind to other proteins. CD155 has been shown to bind to the proteins DNAM-1, TIGIT, and CD96, all of which are expressed by various types of immune cells. To achieve their goal, the researchers changed cancer cells, called B16/BL6 melanoma cells, to produce soluble CD155. When injected into normal mice or mice that are deficient in TIGIT or CD96, the soluble CD155-producing B16/BL6 cancer cells were able to settle and grow in their lungs, more so than compared with B16/BL6 cancer cells that had not been changed. Quite the opposite happened, however, when the same experiment was performed with mice deficient in DNAM-1--the researchers could not find a larger tumor in the lungs of the animals.
"Our results show that DNAM-1 was somehow involved in the tumor-promoting actions of soluble CD155," says lead author of the study Genki Okumura. "Our next goal was to explore further how the two proteins interact to enable the growth of cancer".
The researchers then depleted a certain type of immune cells, called natural killer (NK) cells, in the mice and found that all difference between the mice disappeared. In further experiments, they found that soluble CD155 prevented NK cells from releasing small proteins that are toxic to cancer cells by binding to DNAM-1.
"These are striking results that show how a single protein can drastically change the fate of a tumor. Targeting soluble CD155 could therefore be a new powerful strategy to treat cancer," says Shibuya.
Given that tumor cells have to shield themselves from the immune system to grow, finding and disabling their ways to survive could mean defeating the growth and spread of cancer. Targeting soluble CD155 could mean an improved therapy for various types of cancer. Source:
University of Tsukuba Journal reference:
Okumura, G., et al. (2020) Tumor-derived soluble CD155 inhibits DNAM-1–mediated antitumor activity of natural killer cells. Journal of Experimental Medicine . doi.org/10.1084/jem.20191290 .
Also in Industry News
How to decide whether or not to start treatment for prostate cancer?
Analysis of the SARS-CoV-2 proteome via visual tools
$65m investment increases British Patient Capital’s exposure to life sciences and health technology