Noninvasive biomarkers that detect programmed cell death – apoptosis – would be valuable for predicting early responses to anticancer therapies and for improving drug discovery. Potential targets for molecular imaging of apoptosis include caspase enzymes, which play essential roles in apoptotic signaling pathways. H. Charles Manning, Ph.D., and colleagues used a caspase inhibitor as the basis for developing a PET (positron emission tomography) imaging probe to detect apoptosis in vivo.
In the April 15 issue of Clinical Cancer Research, they report the development of a caspase inhibitor PET probe and demonstrate its utility in mouse models of human colorectal cancer. Using microPET imaging, they showed that the PET probe accumulated in tumors with elevated caspase activity – where tumor cells were dying following drug treatment.
The findings confirm the promise of the caspase inhibitor PET probe for detecting apoptosis in vivo. They suggest that this probe may be translatable to human imaging, where it could be used to assess early treatment responses and personalize cancer medicine.
These studies were supported by grants from the National Institutes of Health (CA140628, CA145138, CA127349, CA128323, CA095103, CA126588, RR017858, MH085768, DK058404, CA136440), with additional support from the Kleberg Foundation.
