Methionine deprivation inhibits glioma growth through downregulation of CTSL.

The metabolism of tumor cells is characterized by the regulation of demand, nutrient supply and metabolic enzymes, which are different in cancer tissues from those in corresponding healthy tissues. There is growing evidence that dietary composition influences biological processes that contribute to tumor incidence and progression as much as genetic status. One possibility for specific dietary interventions in cancer patients is to limit methionine intake. The role of methionine metabolism in tumors suggests that interference with the methionine metabolism network by either drug or environmental effects may show substantial therapeutic effects, but the molecular mechanism is not completely clear. In this study, methionine deprivation was found to downregulate cathepsin L (CTSL) and induce proliferation inhibition in glioma cells. We also demonstrated that CTSL is a tumor-related gene, and promotes the proliferation and invasion of glioma. Our results showed that the treatment of methionine metabolism and CTSL related genes in glioma cells may be a novel strategy for glioma therapy in the future.