Researchers say they can cheaply and easily track how effective some cancer drugs are at cutting off a tumor’s blood supply by using the same gene that gives fireflies their distinctive glow.

Using a technique called bioluminescence imaging (BLI), the University of Teexas Southwestern Medical Center team added a molecule substrate called luciferin to the bloodstream of mice with human breast cancer tumors. The tumors had been altered to carry the firefly gene, so they would emit light when the luciferin reached them.

Using special light-detecting equipment, the researchers detected a correlation between how much light was emitted and the tumors’ growth. The light emission fell drastically after a drug designed to disrupt the blood flow to the cancer cells was given to the mice.

“What we’ve done is offer proof-of-concept that BLI may be an effective and cheaper method to assess drug development and effectiveness,” study senior author Dr. Ralph Mason, director of the UT Southwestern Cancer Imaging Center, said in a prepared statement. “The technique is not intended to be used for imaging tumors or diagnosing cancer in humans, but it potentially allows us to do much more efficient preclinical experiments.”

He stressed that the effectiveness of BLI would depend greatly on the tumor location.

The findings are available online and were expected to be published in a future issue of The Journal of the Federation of American Societies for Experimental Biology.

BLI has some advantages over magnetic resonance imaging (MRI), considered the gold standard of medical imaging, such as allowing some additional detection of cell viability and lower cost, the researchers said.

“Ultimately, the MRI is much more sophisticated and can do more, but BLI is very straightforward,” Mason said. “It’s perfect for evaluating new classes of drugs designed to cause acute vascular changes in tumors, because the tests are inexpensive and easy to do.”

(University of Texas Southwestern Medical Center at Dallas, news release, May 29, 2008 / Healthday News)