Enhancer RNAs (eRNAs), a subclass of non-coding RNAs transcribed from enhancer regions, are increasingly recognized as pivotal regulators of gene expression, though their roles in prostate cancer remain insufficiently understood. This study aims to delineate the eRNA expression profile within a prostate cancer cohort, exploring its role in disease progression and potential clinical applications.

In this study, we employed ATAC-seq and RNA-seq to map the chromatin accessibility landscape in twenty pairs samples of prostate cancer and adjacent benign tissues. Subsequently, we identified an eRNA, lactotransferrin-eRNA (LTFe), that is overexpressed in adjacent non-tumor tissues and successfully knocked down its expression using antisense oligonucleotides. Our in vitro and in vivo experiments examined the impact of LTFe on the proliferation of prostate cancer cells. Additionally, we identified target genes influenced by LTFe through RNA-seq and determined RNA-binding proteins that interact with LTFe using ChIRP-MS. We further validated the role of LTFe in facilitating chromatin loop formation between enhancers and promoters via chromosome conformation capture (3C) experiment. Lastly, we investigated LTFe's function in inducing ferroptosis in prostate cancer cells and assessed the regulatory effects of the androgen receptor (AR) on LTFe, exploring the therapeutic potential of combining AR antagonists with ferroptosis inducers.

High-throughput sequencing identified 4,719 eRNAs, with 346 significantly upregulated and 337 downregulated in prostate cancer tissues. These eRNAs are proximal to genes crucial for prostate development and cancer signaling pathways, underscoring their vital roles in pathophysiological processes. Among these, LTFe was notably overexpressed in normal prostate tissues and implicated in prostate development. Our findings revealed that LTFe enhances LTF transcription of by interacting with heterogeneous nuclear ribonucleoprotein F (HNRNPF) and facilitating enhancer-promoter chromatin loop formation. Moreover, the LTFe-LTF axis was shown to drive ferroptosis via iron transport. AR signaling disrupts these chromatin structures, downregulating LTFe and LTF transcription, thereby inhibiting ferroptosis. Crucially, co-treatment with the AR inhibitor enzalutamide and the ferroptosis inducer RSL3 significantly improved therapeutic efficacy in castration-resistant prostate cancer.

Collectively, this study provides novel insights into the mechanistic role of eRNAs in prostate cancer, identifying the LTFe-LTF axis as a potential therapeutic target and biomarker for improved treatment outcomes.