ERO1A is a hypoxia-ER bridge in NSCLC: from pan-cancer identification to a dual-reporter visualization system.

Abstract

Tumor hypoxia is a hallmark of solid tumor progression, in which hypoxia-inducible factor 1α (HIF-1α) and its signaling network play a pivotal role in regulating tumor progression. Here, leveraging TCGA and GEO datasets through pan-cancer analysis, we rapidly identified 21 candidate genes closely associated with cancer progression and hypoxia response in six cancer types exhibiting high HIF-1α expression. Meanwhile, through literature mining and cellular experiments, ERO1A was identified in NSCLC (Non-Small Cell Lung Cancer) as a gene whose expression patterns highly correlated with HIF-1α. ERO1A, an endoplasmic reticulum (ER) oxidoreductase involved in ER protein quality control and stress response, has been linked to various malignant tumor processes. Our bioinformatics analysis and quantitative cellular experiments indicated its strong association with hypoxia-related HIF-1α signaling, although direct binding evidence between HIF-1α and the ERO1A promoter remains to be established in future studies. However, direct and intuitive cell-level tools for visualizing how the hypoxic microenvironment affects ER function remain limited. To address this gap, we constructed a dual-reporter system, ERO1Ap2-miRFP670/5HRE-EGFP, driven by the ERO1A promoter and hypoxia response element (HRE), respectively. This system enables real-time, visual monitoring of the dynamic interplay between ER function and the tumor hypoxic microenvironment by simultaneously tracking ERO1A promoter activity and HIF-1α pathway activation. This novel tool provides a robust platform for in-depth exploration of the HIF-1α signaling pathway and ER protein quality control mechanisms. Furthermore, it also offers new insights and experimental evidence for developing therapeutic strategies targeting the tumor hypoxic microenvironment.