Loss of Prominin 2 expression inhibits AKT/mTOR signaling to limit glycolysis and drive ferroptosis in breast cancer cells

Abstract

This study aimed to characterize the oncogenic functions of Prominin 2 (PROM2), the pro-cancer and ferroptosis resistance gene, in breast cancer (BC). PROM2 expression was analyzed using single-cell RNA sequencing and the TCGA database. Its expression was confirmed in BC tissues and cell lines using qRT-PCR, immunohistochemistry, and western blot assays. The effects of PROM2 were evaluated in vivo and in vitro. RNA sequencing and GSEA were used to investigate the potential underlying molecular mechanisms of PROM2 in BC. Co-immunoprecipitation was used to determine the interaction between AKT and PROM2. PROM2 expression was elevated in clinical samples and BC cells and positively correlated with a worse prognosis. Functional experiments demonstrated that PROM2 silencing suppressed tumor growth and malignancy. Mechanistically, PROM2 interacts with AKT to activate mTOR signaling, thereby promoting glycolysis and inhibiting ferroptosis. Specifically, for glycolysis, PROM2 silencing decreased glucose uptake, extracellular acidification rate, lactate production, and glycolysis-related enzyme expression, while increasing oxygen consumption. For ferroptosis, PROM2 silencing upregulated reactive oxygen species, malondialdehyde, iron, Fe²⁺, and downregulated SLC7A11, GPX4, and glutathione levels. Overexpression of AKT or the AKT agonist (SC79) reversed the effects of PROM2 silencing on BC cell glycolysis and ferroptosis. Our results suggest that PROM2 is an oncogenic gene that supports BC progression by enhancing glycolysis and inhibiting ferroptosis via AKT/mTOR signaling. Therefore, PROM2 may be a potential therapeutic target for BC treatment.