A new understanding of how cancer works, particularly what causes kidney cancer to recur, was announced last week. Research from the University of Texas Health Science Center at San Antonio (UT) and the Department of Veterans Affairs shows just how kidney cancer is able to resist drug treatment. The full, technical article can be found here.
Normal cells break down nutrients to be processed for energy in its mitochondria. Cancerous cells process energy outside of the mitochondria, which makes the cells resistant to drug therapy. Scientists, led by Karen Block, Ph.D, who joined VA’s Office of Research and Development last year, found an enzyme called NOX4 that is the guilty party as far as kidney cancer evolution.
30 to 40 percent of patients who have kidney cancer removed eventually die because the disease has spread, due to the lack of effective drug therapies. The study shows that the NOX4 enzyme puts off oxygen radicals that help cancer survive while undergoing drug treatment. “However, we found that when we reversed energy production back to the mitochondria, free radical production by NOX4 was shut off allowing the cancer cells to die when exposed to drug treatment,” Block explained in the report.
Through this study, we now understand that NOX4’s purpose is to sense when the energy production switches to the outside of the mitochondria.
“We think that when this mechanism starts, it develops a NOX4 perpetual loop, allowing the cancer to grow and spread,” said Dr. Block. “We also think there is the potential that the loop can be reversed. More research needs to be conducted to better understand the mechanism and how we may be able to use drugs to intervene and at which stage.”
The study was funded with a VA Merit Award and two National Institutes of Health awards.