DNA hypomethylation-activated PRAME drives early-stage lung adenocarcinoma recurrence via ZNF740 and PI3K/AKT/mTOR...

Lung adenocarcinoma (LUAD) represents a major clinical challenge due to its high recurrence and metastasis rates, with the underlying molecular mechanisms yet to be fully elucidated. Despite therapeutic advances, the prognosis of recurrent LUAD remains dismal, creating an urgent demand for novel therapeutic targets. Preferentially expressed antigen in melanoma (PRAME) holds oncogenic potential, but its role in LUAD recurrence and metastasis warrants comprehensive investigation. Therefore, this study aims to systematically investigate the function of PRAME in early-stage LUAD recurrence and metastasis, elucidate its upstream epigenetic regulation and downstream signaling pathways, and identify potential targets for precision therapy in high-risk patients.

To explore the role of PRAME in LUAD, we performed integrative transcriptomic and clinical analyses to assess PRAME expression patterns and their clinical correlation in primary tumor tissues. Functional validation was conducted using female BALB/c nude mouse metastatic and subcutaneous xenograft models to clarify the effects of PRAME on tumor progression. Mechanistic investigations focused on the association between PRAME and epithelial-to-mesenchymal transition (EMT), as well as the PI3K/AKT/mTOR signaling pathway. Chromatin immunoprecipitation (ChIP) assays were used to verify ZNF740 binding to the PRAME promoter, and CRISPRon/CRISPRoff-mediated epigenetic editing experiments were performed to interrogate the regulatory role of promoter methylation in PRAME expression.

Transcriptomic and clinical analyses revealed significant upregulation of PRAME in recurrent primary tumor tissues, and high PRAME expression was strongly associated with reduced recurrence-free survival (RFS). Functional experiments using xenograft models confirmed that PRAME plays an important role in LUAD progression and metastasis. Mechanistically, PRAME exerts its oncogenic effects by inducing EMT and activating the PI3K/AKT/mTOR signaling pathway. ZNF740 was identified as a direct transcriptional activator of PRAME, and ChIP assays confirmed that ZNF740 binds to the PRAME promoter in a manner dependent on DNA hypomethylation. Additionally, CRISPRon/CRISPRoff-mediated experiments demonstrated that PRAME expression is dynamically and bidirectionally regulated by promoter methylation.

Collectively, this study establishes a comprehensive mechanistic framework: DNA hypomethylation facilitates ZNF740 binding to the PRAME promoter, driving PRAME activation, which in turn promotes early-stage LUAD metastasis through the induction of EMT and the activation of the PI3K/AKT/mTOR signaling pathway. These findings support the notion that PRAME might serve as a candidate prognostic biomarker and therapeutic target for recurrent LUAD.