A new study led by the research group of Kivanç Birsoy, head of the Laboratory of Metabolic Regulation and Genetics at The Rockefeller University found a new way to stop tumor growth.
When tumor cells start growing, they multiply infinitely and rapidly due to which the need of oxygen increases and oxygen supply gets scarce due to which cells start suffocating. Moreover, these ever-dividing cells struggle to make enough aspartate in the absence of oxygen. Aspartate is a crucial ingredient in many cellular processes.
In the laboratory, Javier Garcia-Bermudez, a postdoctoral associate in Birsoy’s group cultured the harvested cancer cells from blood, stomach, breast, colon, and lung in the oxygen-deprived condition founded the different behavior of cells. Many of these cells showed inhibition in their growth under low-oxygen-like conditions, but others were less sensitive, and some weren’t bothered at all by the treatment.
Scientist compared the production and metabolites of these cells and found that sensitive cells growth inhibited due to loss of amino acid aspartate in them. Without oxygen, cells were not able to make aspartate but the resistant cells obtained the aspartate from the environment to survive.
Birsoy says he was surprised to see that so much of the oxygen-deprivation problem came down to this one amino acid. He had expected many more metabolites would depend on oxygen supply.
During their research, researchers found that resistant cancer cells turned on a gene called SLC1A3 during the absence of oxygen which in turn suck up aspartate from their surroundings.this was the reason why some cell were able to survive in absence of oxygen. To confirm it Garcia-Bermudez turned on this gene in the lab-grown cancers that were normally sensitive to low oxygen, they grew faster.
The same was true when he transplanted the tumors into mice, providing further support for the idea that aspartate can be a limiting factor for tumor growth when oxygen is scarce. “This is something they’re really starving for,” says Birsoy.
This finding has the potential for creating drugs which can block the production of aspartate as well as blocking its intake from the surrounding.
In the light of this study, anti-aspartate treatment can be used as a substitute for chemotherapy and radiation and it could potentially be effective for any type of tumor-containing oxygen-starved areas. Those parts of tumors tend to resist typical chemo and radiation, Birsoy adds.
The next step of the study is to investigate for the drug which can block aspartate production.