Protein that helps cancer cells source food may offer new treatment target

Published: Tuesday 6 October 2015 at 3am PST | See Original Here

Cancer cells have a nutrient-sensing mechanism that helps them compete with other types of cell for food to fuel growth. Now, new research suggests targeting PAT4 - a protein that supports this mechanism - could be a way to stop tumors growing.

A paper on the study, by the University of Oxford in the UK, is published in the journal Oncogene.

The authors explain that cancer cells often have mechanisms that help them get around the fact they have restricted access to the body's nutrient-rich blood supply.

For their study, they examined the role of PAT4 - an amino-acid transporter protein that supports one of these mechanisms.

They showed that high levels of PAT4 are linked with reduced relapse-free survival after surgery in colorectal cancer patients. They also showed that the link is "independent of other major pathological factors" that influence survival.

Senior author Dr. Deborah Goberdhan, of Oxford's Department of Physiology, Anatomy and Genetics, says:

"We found that aggressive cancer cells manufacture more PAT4, which enables them to make better use of available nutrients than the cells around them - including healthy tissue."

Higher levels of PAT4 correlated with worse cancer outcomes
In another part of the study, the team developed an antibody that highlights PAT4 in human tissue samples. They used it to investigate tumor samples from patients with colorectal cancer.

They found that levels of PAT4 - as identified by the antibody - correlated with the progress of cancer in the patients the tumor samples came from.

Patients whose tumors had higher levels of PAT4 fared less well than those with lower levels; they were at greater risk of relapse and death.

Finally, in experiments on mice grafted with human cancerous tumors, the researchers showed that reducing levels of PAT4 slowed tumor growth.

Dr. Goberdhan concludes:

"These findings support each other. Not only do higher levels of PAT4 mean a worse outcome, but lowering levels improves the situation. This means that we have identified a mechanism, which cancer cells prefer to use and which we might be able to target as part of a combination treatment."

Meanwhile, Medical News Today recently reported new research that suggests taking aspirin may double cancer survival. The study, led by Leiden University Medical Centre in the Netherlands, found that patients with gastrointestinal cancers who took aspirin following their diagnosis were more than twice as likely to survive as counterparts who did not take it.

Written by Catharine Paddock PhD | Copyright: Medical News Today