Compared with normal cells, cancer cells crave – and rely on – getting enormous amounts of glucose.
All indications have been that diets high in starch and sugars – which the body quickly converts to glucose (blood sugar) – fuel tumor growth.
And if curbing their glucose supply inhibits the growth of tumors, that's a goal easily achieved by curbing your intake of starches and sugars.
The reason for the sugar-cancer link lies in a unique metabolic capacity of cancer cells known as “aerobic glycolysis”.
This rare ability helps them resist immune system attacks while undermining the health of surrounding normal cells … powerful advantages that promote faster tumor proliferation (growth).
Now, a research team based at the University of California, Los Angeles (UCLA) has discovered why blood sugar (glucose) fuels cancer growth.
Better yet, they've proven that depriving cancer cells of glucose cripples or kills them … while revealing exactly why sugar-deprivation kills cancer.
To curb or even kill cancer, cut back on sugars and starches
The team was led by UCLA pharmacology professor Thomas Graeber, Ph.D., and included collaborators from Memorial Sloan-Kettering Cancer Center and Weil-Cornell Medical College (Graham NA et al. 2012).
Graeber's group showed that depriving cancer cells of glucose activates a metabolic and cell-signaling “amplification loop” that leads to cancer cell death.
The immediate cause of cancer cell death from sugar deprivation is the toxic accumulation of “pro-oxidant” free radicals.
Free radicals are necessary to normal metabolism, but excess amounts damage cells. They can be controlled by internal antioxidants such as alpha lipoic acid or GTX, food-borne antioxidants like vitamins C and E, and indirect antioxidants like the polyphenols and carotenes in wild salmon and plant foods.
Using a new approach called systems biology – and a sophisticated technology called “unbiased mass spectrometry-based phospho-proteomics” – they examined the metabolic signals and processes inside cancer cells.
They discovered that glucose deprivation activates a “positive feedback loop” that raises the levels of free radicals in cancer cells.
A feedback loop is created because the initial rise in free radicals promotes a process called tyrosine phosphorylation, which raises free radical levels even higher.
As Graeber explained, “Because cancer cells live on the edge of what is metabolically feasible, this amplifying cycle of oxidative stress [from high levels of free radicals] ultimately overwhelms and kills the cancer cell.” (Marcus J 2012)
In addition, the authors showed the possibility of exploiting this positive feedback loop to treat cancers.
Combining short-term glucose deprivation with agents that promote more tyrosine phosphorylation, they demonstrated synergistic cell death in cancer cells.
“Understanding the links between metabolism and signaling will empower new therapeutic approaches toward inducing this metabolic catastrophe,” said co-author Nicholas Graham (Marcus J 2012).
The research was funded by the National Institutes of Health, UCLA's Jonsson Comprehensive Cancer Center, and the California Institute of Technology-UCLA Joint Center for Translational Medicine.
Graham NA, Tahmasian M, Kohli B, Komisopoulou E, Zhu M, Vivanco I, Teitell MA, Wu H, Ribas A, Lo RS, Mellinghoff IK, Mischel PS, Graeber TG. Glucose deprivation activates a metabolic and signaling amplification loop leading to cell death. Mol Syst Biol. 2012 Jun 26;8:589. doi: 10.1038/msb.2012.20
Marcus J. Glucose deprivation activates feedback loop that kills cancer cells, UCLA study shows. June 26, 2012. Accessed at http://newsroom.ucla.edu/portal/ucla/researchers-discover-that-glucose-235478.aspx
How sugar deprivation
kills cancer cells