CRBN deletion enhances mitochondrial metabolism by stimulating mitochondrial calcium accumulation in non-small cell lung cancer

Abstract

CRBN (Cereblon), a substrate receptor of the CRL4 (Cullin4-RING E3 ubiquitin ligase) complex, has emerged as a key player in cancer metabolism. While its role in influencing metabolic phenotypes has been suggested, the precise functions of CRBN in cellular metabolism and cancer progression remain underexplored. This study investigates the impact of CRBN downregulation in lung cancer, focusing on mitochondrial metabolism and cellular functions. Data from The Cancer Genome Atlas (TCGA) and the Clinical Proteomic Tumor Analysis Consortium (CPTAC) revealed significant reductions in CRBN expression at both mRNA and protein levels in lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC). This downregulation was further confirmed in most lung cancer cell lines examined. Functional analyses of CRBN knockout (KO) cells revealed substantial alterations in mitochondrial metabolism, including enhanced oxidative phosphorylation, increased mitochondrial membrane potential (ΔΨm), and elevated production of mitochondrial reactive oxygen species (mROS). CRBN deficiency also accelerated tricarboxylic acid (TCA) cycle flux and increased mitochondrial calcium accumulation, contributing to elevated ΔΨm and potentially compromised mitochondrial integrity. Additionally, CRBN KO cells demonstrated increased cell migration, which could be mitigated by inhibiting mitochondrial calcium import. These findings suggest that CRBN plays a pivotal role in regulating mitochondrial function and metabolic activity in non-small cell lung cancer. The loss of CRBN enhances mitochondrial metabolism and contributes to increased cancer cell migration, providing new insights into the metabolic adaptations associated with CRBN deficiency in cancer progression.