"Each type of cancer appears to have its own metabolic signature," Nagrath said. "For instance, kidney cancer does not rely on glutamine, and though breast cancer gets some of its energy from glutamine, it gets even more from glycolysis. For other cancers, including glioblastoma and pancreatic cancer, glutamine appears to be the primary energy source."
Nagrath, director of Rice's Laboratory for Systems Biology of Human Diseases, said the new metabolic analysis indicates that ovarian cancer may be susceptible to multidrug cocktails, particularly if the amounts of the drugs can be tailored to match the metabolic profile of a patient's tumor.
The research also revealed a specific biochemical test that pathologists could use to guide such treatments. The test involves measuring the ratio between the amount of glutamine that a cell takes up from outside and the amount of glutamine it makes internally.
"This ratio proved to be a robust marker for prognosis," said MD Anderson co-author Anil Sood, professor of gynecologic oncology and reproductive medicine and co-director of the Center for RNA Interference and Non-Coding RNA. "A high ratio was directly correlated to tumor aggression and metastatic capability. Patients with this profile had the worst prognosis for survival."
The three-year study included cell culture studies at Rice as well as a detailed analysis of gene-expression profiles of more than 500 patients from the Cancer Genome Atlas and protein-expression profiles from about 200 MD Anderson patients.
"The enzyme glutaminase is key to glutamine uptake from outside the cell, and glutaminase is the primary target that everybody is thinking about right now in developing drugs," Nagrath said. "We found
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