Naturally fluorescent molecules may serve as cancer...( Excess amounts of a naturally fluore...),Health

Excess amounts of a naturally fluorescent molecule found in all living cells could serve as a natural biomarker for cancer, according to bioengineers.

NADH, or nicotinamide adenine dinucleotide, is a key coenzyme -- a non-protein molecule necessary for the functioning of an enzyme -- found mostly in the inner membrane of a cell's power plant, or mitochondria. It fuels a series of biochemical reactions that involve various enzymes to produce ATP, the major energy source in cells. In the event of disease or a metabolic disorder, these enzymes and their related reactions can become disabled, causing a buildup of unused NADH.

"Dysfunctional enzymes in the mitochondria are known to be associated with serious health problems such as cancer and neurodegenerative diseases," said Ahmed Heikal, associate professor of bioengineering, Penn State. "By detecting the level of NADH and its distribution inside living cells, we should be able to monitor the mitochondrial activity and thus the integrity of any given cell, without adding potentially toxic dyes or actually destroying the cell."

According to Heikal, one of the main challenges in cancer diagnosis is the ability to differentiate cancer cells from normal ones at the early stages of tumor progression.

To tease apart the critical difference between normal and cancerous cells, the researchers used the fluorescence of natural NADH. Using a combination of state-of-the-art spectroscopy and microscopy techniques, the researchers were able to convert such fluorescence into an accurate measure of NADH concentration in live cells. Heikal and Yu, graduate student, bioengineering, have found that the average concentration of NADH in breast cancer cells is about twice that in normal breast cells.

"If we are given two live cells, one normal and the other cancerous, we could differentiate between the two with confidence," said Heikal, whose team's findings appear today (April 2) in the Journal of Photochemi
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