Scientists have discovered a new mechanism of amino acid uptake by tumor cells through pinocytosis

The physiological function of mammalian tissues depends on the support of various nutrients We know that the changes of human metabolites are involved in the pathological process of cancer, but we know little about which nutrients support the rapid growth of the whole cancer cells Amino acids are essential nutrients for most cancer cells Cancer cells can absorb extracellular protein metabolites as the source of amino acids by means of pinocytosis, which is an important source of nutrition for pancreatic cancer cells However, whether the nutritional source of amino acids in this way of pinocytosis can maintain the level of amino acids in pancreatic cancer cells remains to be further studied The team from Koch Institute of oncology in the United States labeled albumin with a stable nitrogen isotope and delivered it to mouse liver tissue by plasma exchange It was found that the metabolites of these albumin are important sources of amino acids for pancreatic cancer cells The researchers also used a micro transplantation device to deliver these labeled albumin directly into pancreatic cancer tissue, and observed that the amino acids metabolized by these labeled albumin were directly absorbed by tumor cells through pinocytosis By inhibiting the pinocytosis of tumor cells with inhibitors, the level of amino acids in tumor cells can be significantly reduced, and then the growth of tumor can be inhibited Therefore, inhibition of tumor cell pinocytosis by drugs or genes can cut off the important nutritional sources of tumor cells, which is a potential therapeutic target.