Restricting a key cellular nutrient could slow tumor growth
Remove tumor cells from a living organism and place them in a dish, and they will multiply even faster than before. The mystery of why this is has long stumped cancer researchers, though many have simply focused on the mutations and chains of molecular reactions that could prompt such a disparity. Now, a group of MIT researchers suggests that the growth limitations in live organisms may stem from a different source: the cell’s environment. More specifically, they found that the amino acid aspartate serves as a key nutrient needed for the “proliferation” or rapid duplication of cancer cells when oxygen is not freely available. The biologists took cancer cells from various tissue types and engineered them to convert another, more abundant substrate into aspartate using the gene encoding an enzyme from guinea pigs. This had no effect on the cells sitting in a dish, but the same cells implanted into mice...