New York: Fasting combined with a less-toxic class of drugs may starve cancer cells to death so effectively that the new treatment may one day replace chemotherapy, suggests new research.
Published in the journal Oncotarget, the research was carried out in mice.
"If shown to work in humans, this combination could replace chemotherapy and make fasting a potent component of a long-term strategy to treat cancer," said senior author Valter Longo from University of Southern California Davis School of Gerontology.
"Like every other cell, cancer cells need energy to survive and keep growing. But cancer cells are fairly inflexible about how they produce that energy, which gives us a way to target them," Longo noted.
Cancer cells rely heavily on glucose (sugar) from food for energy -- they are on overdrive, burning much more glucose than a regular cell to fuel their rapid growth.
The phenomenon is called the Warburg effect, named after the German physician who first described it nearly 100 years ago. As such, cancer cells are much more vulnerable to any interruption in supply.
Deprived of glucose, cancer cells rely on an emergency backup -- using a type of enzyme called a kinase to continue their growth-related activities, the study pointed out.
Longo and his collaborators discovered that this metabolic shift by cancer cells causes them to generate toxic-free radicals, which ultimately kills them.
With the help of kinase inhibitor drugs, cancer cells' ability to generate energy can be further choked, the researchers noted.
Kinase inhibitors are already approved by the US Food and Drug Administration (FDA) as a cancer treatment, opening the door to using them and fasting as a new therapy to knock out cancer.
"However, kinase inhibitors, though much less toxic than chemotherapy, can still be toxic to many cell types. Fasting makes them more effective, meaning that patients would have to use them for less time to achieve the same results," Longo said.