Genetic Imaging and Diagnosis of Cancer

Cancer covers a broad spectrum of diseases, in every tissue of the body. Tissues are composed of cells, which normally grow slowly, under the tight control of a network of regulatory genes. The slow accumulation of activating mutations in growth genes, and inactivating mutations in suppressor genes, eventually allows a cell to grow out of control. Relapse is due to the development of resistant cells, rather than the escape of sensitive cells, suggesting the need for new approaches to treatment of the disease.

GeneSeen is developing cancer gene-specific nuclear medicine agents for use in diagnostic imaging. Cancers of the blood, breast, colon, lung, ovary, pancreas, and prostate are currently being studied. Cancer genes of immediate interest include CCND1, MYCC, HER2, and KRAS.

To see cancer gene activity from outside the body, we make our nuclear medicine agents from small bits of genetic code, 12 letters of code at a time, that can bind uniquely to a genetic message from an active gene. We add a tiny piece of protein to one end of the code in order to direct the agents to cancer cells. We add a radioactive metal to the other end of the code. Below we show an idealized picture of the nuclear medicine agent (reporter-PNA-ligand), targeted first to a receptor on a cancer cell, then bound to a cancer gene message (mRNA).

After administration of the nuclear medicine agents to an animal or a patient, we can then record an image of the hyperactive cancer genes by single photon emission computed tomography (SPECT) or positron emission tomography (PET) imaging. To the right, we show an idealized picture of high energy light emissions from small tumors developing around blood vessels.

We are also at work on non-radioactive agents that will allow us to see hyperactive cancer genes by magnetic resonance imaging (MRI) or by near infrared fluorescence (NIRF) imaging.