Weibo Cai is Lighting Up Personalized and Precision Medicine
Weibo Cai, center of top row, is pictured with his research team.
No two cancers are the same, which means there is no “one size fits all” approach to treatment. Modern cancer therapies try to provide treatments that are selected for a patient’s specific cancer. This personalized approach requires the ability to noninvasively detect, characterize, and monitor tumors and tumor growth – a process made possible through targeted imaging.
“There are many different ways targeted agents can play a role in the treatment of cancers,” Cai said. “For example, a targeted imaging agent can help pick the right patient for the right treatment, and it can really help improve the success rate of a targeted treatment.”
Targeting imaging agents generally contain two components. The first is an isotope or dye molecule that “lights up” when using an imaging technique, such as a PET scan. The second is an antibody, protein, or peptide that binds to specific receptors or antigens on tumor cells or other cells in the tumor environment.
Cai’s research in this area spans from developing new radioactive PET tracers to preparing various nanomaterials that contain both imaging and therapeutic agents.
“Our research is quite broad. Some people might think we’re spread all over the place,” Cai said. “But it’s like a pyramid: you have to have a very big base. The vast majority of technologies will never go to the clinic. But when you have a big base, then you have multiple options at the top of the pyramid that can be translated.”
Multimodal imaging, an approach where two or more different imaging units are included in a single targeted imaging agent, is of particular interest to Cai, who has developed numerous MRI/PET, PET/optical, and PET/photoacoustic imaging agents. The combination of multiple imaging techniques allows for much better resolution and characterization of the specific target.
“There is a need for multimodal imaging contrast agents, which is something we put a lot of effort towards,” Cai said. “If you use them properly, different imaging techniques can be complementary. In some cases, they can also be synergistic, where one plus one can be much more than two. There are also multiple modality imaging techniques where there can be three or four agents, depending on the application.”
In addition to pairing multiple imaging agents with the same targeting component, therapeutic agents can also be installed. This approach, called “theranostics”, allows specific tumor growths to be visualized and treated with the same agent. Most recently, Cai reported the use of a single targeted agent that contained both an antibody-bound PET tracer and beta emitter for the detection and treatment of mouse models of breast cancer.
“Chemotherapy is non-specific and only targets fast growing cells. That’s why you see a lot of side effects, such as hair falling out,” Cai said. “Targeted imaging agents that are labeled with a radioisotope for diagnosis or for monitoring treatment can also be labeled with a therapeutic isotope for potential targeted therapy.”
Though Cai’s current technologies have not yet been brought forward to clinical trials for cancer treatment, they are finding applications in the treatment of other diseases. The ability to provide practical techniques and solutions drives his research.
“The technology is quite well developed, though there is always room for improvement. The reality is that it takes a very long time to translate that technology into the clinic. I talk with a lot of doctors and clinicians to learn what they need and if we’re equipped to provide it,” Cai said. “We need to make sure what we’re doing is clinically relevant or clinically significant.”
Date Published: 11/13/2018