The role of cytidine 5′‐triphosphate synthetase 1 in metabolic rewiring during epithelial‐to‐mesenchymal transition in non‐small‐cell lung cancer

Epithelial‐to‐mesenchymal transition (EMT) contributes to the poor prognosis of patients with cancer by promoting distant metastasis and anti‐cancer drug resistance. Several distinct metabolic alterations have been identified as key EMT phenotypes. In the present study, we further characterize the role of transforming growth factor‐β (TGF‐β)‐induced EMT in non‐small‐cell lung cancer. Our study revealed that TGF‐β plays a role in EMT functions by upregulation of cytidine 5′‐triphosphate synthetase 1 (CTPS), a vital enzyme for CTP biosynthesis in the pyrimidine metabolic pathway. Both knockdown and enzymatic inhibition of CTPS reduced TGF‐β‐induced changes in EMT marker expression, chemoresistance and migration in vitro. Moreover, CTPS knockdown counteracted the TGF‐β‐mediated downregulation of UDP‐glucuronate, glutarate, creatine, taurine and nicotinamide. These findings indicate that CTPS plays a multifaceted role in EMT metabolism, which is crucial for the malignant transformation of cancer through EMT, and underline its potential as a promising therapeutic target for preventing drug resistance and metastasis in non‐small‐cell lung cancer. Epithelial‐to‐mesenchymal transition (EMT) contributes to cancer metastasis and drug resistance. Cytidine 5′‐triphosphate synthetase 1 (CTPS) is upregulated by transforming growth factor‐β (TGF‐β), promoting EMT in non‐small‐cell lung cancer. Inhibiting CTPS reduces EMT marker expression, chemoresistance and cell migration. In addition, CTPS knockdown reverses TGF‐β‐induced metabolic changes. Therefore, CTPS significantly influences EMT‐related functions and metabolic alterations, highlighting its role in cancer progression.