Fig. 2

Glutamine addiction in cancer cells. A The process of glutamine catabolism in tumor cells, as well as potential gene alterations that can impact glutamine metabolism. Glutamine is transported into the cell through membrane amino acid transporters, such as SLC1A5, SLC6A14, and SLC38A1/2, where it undergoes a dehydrogenation reaction catalyzed by GLS to form glutamate. Glutamate then converts to α-KG through the action of GLUD, GOT or GPT, entering the TCA cycle for energy production. The green region represents the influence of various gene alterations on different nodes of glutamine metabolism. B Multiple glutamine transporter proteins have been observed to undergo upregulation across different types of cancer. GLS, glutaminase; GPT, glutamate pyruvate transaminase; GOT, glutamic-oxaloacetic transaminase; GLUD, glutamate dehydrogenase; α-KG: α-ketoglutarate; TCA: tricarboxylic acid; TNBC: triple-negative breast cancer; NSCLC: non-small cell lung cancer; HNSCC: head and neck squamous cell carcinoma; ER + : estrogen receptor positive