Houston Scientists Probe Obesity-Cancer Connection
by: Carrie Feibel, October 16, 2012 5:10:00 pm
Doctors have known for a long time that being obese puts you at greater risk for developing certain types of cancer, such as breast and colorectal.
And, they’ve also observed that once obese people get cancer, sometimes it progresses faster and is harder to treat.
But the question is why? Is it what obese people are eating? Or something in the fat tissue itself?
Mikhail Kolonin is an associate professor at the University of Texas Health Science Center at Houston. His latest study started out with two groups of mice, one fat, one thin.
But then Kolonin fed them the exact same diet while monitoring the tumors inside their bodies.
“What we found was when you take genetically identical mice that are either lean or obese and you put experimental tumors into them, tumors will grow faster in mice that are obese as compared to mice that are lean, even though they are on the same diet.”
Kolonin says this shows something in body fat itself is making a tumor grow faster.
Scientists know that fat tissue releases different hormones and growth molecules and they’ve suspected these could help feed a tumor, but Kolonin discovered something else.
He found that actual stem cells from the fat were migrating through the blood, lodging in the tumor, and helping it grow and build blood vessels.
“The tumor is getting fat.”
It’s almost as if the tumor is recruiting these fat cells, or hijacking them for its own purposes.
“Tumors are creatures that want to survive. And when they start growing large enough, they don’t get enough oxygen, they don’t get enough nutrients at certain point, and they start suffocating and they start releasing signals that scream for help. They start screaming we need air, we need food. And the body comes to the rescue unfortunately.”
Kolonin says the next step is to find a drug to inactivate the migrating fat cells, or eliminate them from the bloodstream.
This could slow or stop a tumor’s growth.
“This research is very relevant to America as much as the rest of the world today, because it’s projected that in a couple of decades, half of Americans are going to be officially obese. And children are getting more obese, so the prediction is that we are going to start seeing more cancers in the childhood.”
Kolonin says that a drug that attacks the cancer-fat connection might also be used to treat obesity itself.
The study appeared in the journal Cancer Research.