RUNX1-IT1 favors breast cancer carcinogenesis through regulation of IGF2BP1/GPX4 axis

Abstract

Abstract Breast cancer is the most common malignancy among women and the leading cause of cancer deaths, with complicated pathogenesis that is largely unknown. In this study, we identified a novel long non-coding RNA (lncRNA) as a critical driver of breast cancer tumorigenesis. RUNX1 intronic transcript 1 (RUNX1-IT1) was notably overexpressed in human breast cancer tissues, and knockdown of RUNX1-IT1 inhibited breast cancer cell viability and invasion, as well as tumor growth in orthotopic transplantation model. Further, RUNX1-IT1 repressed ferroptosis, a novel iron-dependent form of regulated cell death, via increasing glutathione peroxidase 4 (GPX4) expression. Specifically, RUNX1-IT1 directly bound to N6-methyladenosine m6A reader IGF2BP1 and promoted the formation of (insulin like growth factor 2 mRNA binding protein 1) IGF2BP1 liquid-liquid phase separation (LLPS) biomolecular condensates, resulting in more IGF2BP1 occupation on GPX4 mRNA, increasing GPX4 mRNA stability. Moreover, high RUNX1-IT1 was linked to poor prognosis, and a strong positive correlation between RUNX1-IT1 and GPX4 was observed in clinical breast cancer tissues. Taken together, our data reveal that RUNX1-IT1 promotes breast cancer carcinogenesis through blocking ferroptosis via elevating GPX4, targeting of the previously unappreciated regulatory axis of RUNX1-IT1/IGF2BP1/GPX4 may be a promising treatment for patient with breast cancer.

Keywords

• Long non-coding RNA
• Breast cancer
• Ferroptosis
• m6A reader
• mRNA stability