Predicting how atherosclerosis, osteoporosis or cancer will progress or respond to drugs in individual patients is difficult. In a new study, researchers took another step toward that goal by developing a technique able to predict from a blood sample the amount of cathepsins-protein-degrading enzymes known to accelerate these diseases-a specific person would produce.
This patient-specific information may be helpful in developing personalized approaches to treat these tissue-destructive diseases.
"We measured significant variability in the amount of cathepsins produced by blood samples we collected from healthy individuals, which may indicate that a one-size-fits-all approach of administering cathepsin inhibitors may not be the best strategy for all patients with these conditions," said Manu Platt, an assistant professor in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University.
The study was published online on Oct. 19, 2012 in the journal Integrative Biology. This work was supported by the National Institutes of Health, Georgia Cancer Coalition, Atlanta Clinical and Translational Science Institute, and the Emory/Georgia Tech Regenerative Engineering and Medicine Center.
Platt and graduate student Keon-Young Park collected blood samples from 14 healthy individuals, removed white blood cells called monocytes from the samples and stimulated those cells with certain molecules so that they would become macrophages or osteoclasts in the laboratory. By doing this, the researchers recreated what happens in the body-monocytes receive these cues from damaged tissue, leave the blood, and become macrophages or osteoclasts, which are known to contribute to tissue changes that occur in atherosclerosis, cancer and osteoporosis.
Then the researchers developed a model that used patient-varying kinase signals collected from the macrophages or osteoclasts to predict patient-specific activity of four cathepsins: K, L, S and V.