Extra gene keeps mice cancer-free and permanently skinnyS

The gene PTEN is a tumor suppressor, making it one of the best genes to have in the fight against cancer. But the latest research suggests that preventing cancer is just the beginning of all the amazing things this gene can do.

Usually, the phrase "too much of a good thing" is all over medical science — even if something is beneficial at one dosage, there's zero guarantee that increasing the dosage will make it even better. But the initial research on PTEN suggests that it might be a rare exception... at least, if you're a mouse. Crucially, it seems that tumor suppressor genes aren't simply about stopping cancer, and their full range of benefits is just waiting to be unlocked.

Researchers at the Spanish National Cancer Research Center recently conducted an experiment in which they gave some mice an extra dose of the PTEN gene. In both mice and humans, PTEN is one of the key genes responsible for controlling cell growth, and signalling cells when it's time stop dividing and undergo cell death. As cancer starts to spread, the PTEN gene is one of the first to be destroyed so that the cancerous cells can start their runaway growth, and thus the tumor forms.

Giving the mice more than the naturally recommended dose of PTEN kept them cancer-free, which suggests that having multiple genomic copies of the tumor suppressor allowed it to fend off any harmful mutations or attempted deactivation. That's potentially good news for expanding PTEN's role in cancer prevention, but the potentially great news is the side effects of the extra gene.

The mice with the extra PTEN had a metabolic imbalance, although it's the type of imbalance that people in the midst of an obesity epidemic would be all too happy to have. The experimental mice ate more and yet remained thinner than the control group. The researchers also report that the mice were less likely to be insulin-resistant and their livers had less fat in them than those of other mice. Basically, the mice were leaner and healthier, even though they were eating more.

The researchers believe the source of this extra protection is found in the brown fat cells, which had become overactive and were burning tons of extra calories. It seems the extra dosage of PTEN both increased the brown fat cell activity and made it easier for those cells to form. According to research leader Manuel Serrano, "This tumor suppressor protects against metabolic damage associated with aging by turning on brown fat."

We're probably several years away from knowing what benefits this finding might have for people, but the early results are encouraging. The researchers have identified a compound inhibitor that can mimic the effects of the extra PTEN gene, meaning it could be possible to enjoy all these benefits without rewriting your DNA. If that's the case, then this finding could provide the road to a drug that lets you enjoy your body's natural protections against cancer, obesity, and cardiovascular problems throughout our entire lives — not just when you're young.

Via Cell Metabolism. Image by mathagraphics, via Shutterstock.