Using precise, radioactively labeled genetic probes, researchers at Jefferson Medical College have seen cancer gene activity from outside the body in laboratory mice. The probes, which work by attaching to genetic codes copied from an active cancer gene, may someday aid physicians and scientists in cancer detection and in determining the appropriate treatment for a cancer.
"Patients might be able to avoid a great deal of worry and unneeded surgery if cancer gene activity could be detected from outside the body," says Eric Wickstrom, Ph.D., professor of biochemistry and molecular pharmacology and microbiology and immunology at Jefferson Medical College of Thomas Jefferson University in Philadelphia and at Jefferson's Kimmel Cancer Center.
The scientists would like to detect cancerous breast tumors as early as possible, particularly before they begin to spread to other areas of the body. "We want to detect them before mammograms can find them," Dr. Wickstrom says. "We want to see whether a cancer gene is active, which will tell clinicians the best way to treat it, according to the cancer gene activity of the tumor. If we can see the hotspot of cancer gene activity before the tumor has formed, we can start to treat earlier." The researchers report their results in December in the Journal of Nuclear Medicine.
The gene, called cyclin D1, is turned on in the majority of breast cancers, he explains. The genetic probe, which is a DNA derivative, carries an attached radioactive label, and binds to cyclin D1 messenger RNA (mRNA). The latter is involved in translating DNA instructions and making proteins.
Dr. Wickstrom, Mathew Thakur, Ph.D., professor of radiology at Jefferson Medical College and their co-workers contend that the strategy – using genetic probes to visualize sites of cancer gene activity – can work for detecting the activity of other cancer genes in various types of tumors.
"The radioactive probes can help us identify the cancer cells at an early stage," says Dr. Thakur. "In this technology, we've shown the proof of principle. Several other cancers show characteristic activated genes that we might also be able to use for early diagnosis, such as pancreatic cancer, prostate cancer and colon cancer."