A research team led by Emory University School of Medicine, Winship Cancer Institute have found a way of preventing cancer cells from consuming amino acids, which form the building blocks of proteins and other biomolecules. In addition to consuming sugar at a fast rate, cancer cells also hunger for amino acids. The Winship team has found a way to exploit that hunger into preventing the growth of leukemia cells.
The researchers identified a transporter enzyme called “ASCT2“, which brings amino acids into cells, as a target for anticancer drugs. Eliminating ASCT2 selectively stops the growth of leukemia cells while having limited effects on healthy blood cells and hematopoietic (blood-forming) stem cells reports the Business Herald.
Challenges to Date
The lead investigator, Dr. Cheng-Kui Qu, professor of pediatrics at Emory University School of Medicine, Winship Cancer Institute. He noted in the Business Herald article that “So far, little progress has been made in finding therapeutic targets in amino acid metabolic pathways that can be harnessed to kill cancer cells but spare normal cells. This is a highly promising therapeutic target for leukemia. ASCT2 is dispensable for normal blood cell development, but it is required for leukemia development and progression.” In leukemia cells, ASCT2 loss generates a system-wide effect on cellular metabolism, disrupts leucine influx and mTOR signaling, and induces apoptosis.
Dr. Qu and his team found that gene encoding ASCT2 could be deleted from mice without substantially disturbing blood cell development. However, the mice took longer to recover white blood cell counts after the stress of chemotherapy drugs or radiation. The test inhibiting ASCT2 in mice grafted with human leukemia had a material therapeutic effect. The team however also noted that the drug used had low potency and probably wasn’t specific for clinical purposes. Other research groups have uncovered ASCT2’s ability to control tumor growth in other cancers.
Dr. Cheng-Kui Qu, professor of pediatrics at Emory University School of Medicine, Winship Cancer Institute