"Most drugs against obesity fail in transition between rodents and primates," Pasqualini said. "All rodent models of obesity are faulty because their metabolism and central nervous system control of appetite and satiety are very different from primates, including humans. We're greatly encouraged to see substantial weight loss in a primate model of obesity that closely matches the human condition."
The rhesus monkeys in the current study were "spontaneously" obese, said study first author Kirstin Barnhart, D.V.M, Ph.D., a veterinary clinical pathologist at MD Anderson's Keeling Center for Comparative Medicine and Research in Bastrop, Texas. No specific actions were taken to make them overweight; they became so by overeating the same foods provided to other monkeys in the colony and avoiding physical activity.
The wider problems of obesity
This primate model also shares other physiological features associated with human obesity, such as metabolic syndrome, characterized by an increased resistance to insulin, which can lead to the development of type 2 diabetes and cardiovascular disease. Adipotide-treated monkeys showed marked improvements in insulin resistance using about 50 percent less insulin after treatment.
Arap, Pasqualini and colleagues are preparing for a clinical trial in which obese prostate cancer patients would receive daily injections of Adipotide for 28 consecutive days. "The question is, will their prostate cancer become better if we can reduce their body weight and the associated health risks," Arap said.
Some prostate cancer treatments, such as hormone therapy, cause weight gain. Greater weight can lead to arthritis, which in turn causes inactivity that leads to more weight gain, a cascade effect of co-morbidities, Arap said. Fat cells
|Contact: Scott Merville|
University of Texas M. D. Anderson Cancer Center