"Cancer cells not only make significantly more heme, we also found they uptake more heme from the blood," said Zhang, who holds the Cecil H. and Ida Green Distinguished Chair in Systems Biology Science.
Zhang and Hooda then treated the matched set of lung cancer and normal lung cells with a heme inhibitor called succinyl acetone. The chemical blocks cells from synthesizing heme.
Other researchers have previously studied the ability of succinyl acetone to inhibit growth of various types of cancer cells, but until the UT Dallas study, Zhang said it was not known whether those effects were unique to cancer in general or how the compound might affect normal cells.
"Before our study, scientists didn't know whether there was any difference in effect between cancer cells and normal cells," Zhang said. "Now we know that this compound doesn't have much effect on normal cells, but it does have an effect on lung cancer cells."
Inhibiting the cancer cells' ability to produce heme affected those cells dramatically, said Hooda, who was the lead author of the study.
"Suppressing heme availability reduced the lung cancer cells' ability to use oxygen, and hence the cells' ability to proliferate and migrate," he said. "The cultured cancer cells we studied stopped proliferating and eventually died."
Zhang said a key finding was that normal cells don't need that much heme to function properly.
"When you inhibit heme synthesis or deplete heme, it doesn't affect normal cells too much," she said. "It selectively affects cancer cells. That's the beauty of our work.
"Because inhibiting heme effectively arrested the progression of lung cancer cells, our findings could positively impact research on lung cancer biology and therapeutics."
The National Cancer Institute estimates that 228,000 new cases of lung cancer will be diagnosed and more than 159,000 deaths from the disease will occur in the U.S. in
|Contact: Amanda Siegfried|
University of Texas at Dallas