RE ENGINEERED PROTEINS SUPRESS KIDNEY CANCER

In a study published in the first issue of EMBO Molecular Medicine, Canadian researchers modified the tumor inhibiting protein, von Hippel-Lindau (VHL), and demonstrated that it could suppress tumor growth in mice.

When solid tumors grow, they often have relatively poor and disorganized blood supplies. As a result, various regions including the centre of the tumor have low levels of oxygen. Cells in these hypoxic areas produce hypoxia-inducible factor (HIF) that helps them carry on growing. Consequently, HIF is also associated with aggressiveness in some of the most common types of cancer, including prostate, breast, colon and lung cancer. Under normal conditions, VHL degrades HIF, but VHL is deactivated when oxygen levels are low. So, in hypoxic regions of a tumor, just where VHL is needed to inhibit cancer, it is ineffective.

The researchers, therefore, engineered a new version of VHL that does not stop working when oxygen is scarce. Introducing this newly engineered version of VHL into mice that had kidney tumors dramatically reduced levels of HIF, caused tumors to regress and limited the formation of new blood vessels within the tumors.

"The level of HIF is usually very high under conditions of low oxygen, but when we put in our bioengineered VHL its levels go right down to a level that would be comparable to that in normal oxygen levels" says lead researcher Professor Michael Ohh, who works in the Faculty of Medicine at the University of Toronto.

Their findings could have implications for any type of cancer in which HIF plays a role. They used kidney cancer as a model because it is one of the most resistant tumors to the conventional radiation and chemotherapy, but their findings provide a novel concept that could potentially serve as a foundation for smarter anti-cancer strategy for a wide variety of cancers.

http://www.ecancermedicalscience.com/news-insider-news.asp?itemId=475

MITHIL CHOKSHI
SECTION # 501