Prostate cancer is, by far, the most commonly diagnosed cancer among American men. Ridding the body of it would be so much easier if medical oncologists could see the cancerous cells and kill them where they hide. Yubin Miao, PhD, has developed a tool to do just that.
The new peptide he and his team at the UNM Cancer Center have developed strongly binds to a receptor that prostate cancer cells display in abundance. Normal cells display few or none of these receptors. “This receptor is overexpressed on prostate cancer cells,” Miao says. “By targeting the receptors, you can differentiate cancer cells from normal cells.”
Miao’s team derived their molecule from a naturally occurring peptide, engineering it to have a far stronger binding affinity and include a radioactive atom called a radionuclide. They used several intricate chemical reactions to create these custom-designed peptides, then thoroughly tested their binding affinity.
Radionuclides can be used for either diagnostic or therapeutic purposes. Attaching a radionuclide that emits gamma rays makes the peptide visible in a SPECT or PET scan, allowing doctors to locate the cancer cell the peptide has bound itself to. A radionuclide that gives off beta rays will kill the tumor cell once the peptide has latched on. Miao and his team coined the term “theranostic” to describe their peptide’s dual therapeutic and diagnostic ability.
The team is testing the peptide in animal models to pave the way for human studies. They hope their man-made peptide will be used in a clinical setting to help medical oncologists find and kill cancer cells wherever they may be.