The ferroptotic effect of NRF2-GCLM signaling axis derived by radiotherapy of esophageal squamous cell cancer: the vivo study

Nuclearfactor erythroidderived 2-like 2(NRF2) is a major regulator of the body's antioxidant defense system and a key protein in the process of ferroptosis, which is upregulated in a variety of malignancies. This study aimed to investigate the role of NRF2 in the pathogenesis and progression of Esophageal squamous cell carcinoma (ESCC) from the in vivo and clinical levels. The expression levels of NRF2, Glutamate-Cysteine Ligase Modifier Subunit (GCLM) and Glutathione Peroxidase 4 (GPX4) in ESCC and adjacent normal tissues were detected by immunohistochemistry in 61 tissue biopsies collected from patients diagnosed with ESCC. The xenograft model was used to detect the growth of nude mouse tumors and the changes of ferroptosis-related indexes in different experimental groups. Co-immunoprecipitation was used to demonstrate the downstream interacting proteins of NRF2. The results showed that the expression of NRF2, GCLM and GPX4 was increased in ESCC compared with adjacent non-tumor tissues, and the high expression of NRF2, GCLM and GPX4 was significantly associated with poor prognosis. NRF2 overexpression promotes changes in tumor growth and ferroptosis-related markers in xenograft models. In addition, NRF2 overexpression was associated with upregulation of GCLM and GPX4. CO-IP demonstrated that GCLM is a downstream protein of NRF2. Bio-informatics analysis showed that GCLM was differentially expressed in a variety of tumors, and was significantly correlated with the prognosis of patients, as well as the infiltration of a variety of immune cells. Finally, GCLM promotes tumor growth and radiotherapy resistance to ESCC in vivo, and can therefore be used as a molecular target for tumor therapy.