Abstract 3801: Identification of circular RNAs associated with the ferroptosis of pancreatic cancer cells

Abstract

Abstract The five-year survival rate for pancreatic cancer patients is significantly low which is predominately due to the lack of early-detection biomarkers, and poor response to currently available treatments that include drug resistance development. Recent studies suggest cancer cells can be highly sensitive to a newly defined type of cell death, ferroptosis, which is related to the development of resistance to standard chemotherapy drugs for pancreatic cancer such as gemcitabine and 5-Fluorouracil. However, the role of circular RNAs (circRNAs) in ferroptosis remains largely unexplored. Hence, this project aims to identify circRNAs in ferroptosis to uncover further components and mechanisms, and potentially provide specific effective targets for anticancer therapies. To achieve this, different ferroptosis inducers were tested, where the cystine-depletion method demonstrated higher efficiency based on cell viability and ferroptosis markers such as iron and lipid peroxidation levels. This method was used to induce ferroptosis for 24 hours in pancreatic cancer cells for subsequent circRNA sequencing, and to establish a ferroptosis-resistant cell line. From the sequencing data, 31 differentially expressed (DE) circRNAs were obtained, and eight were selected for further validation. Three circRNAs; circPPP2R2B, circNDUFAB1, and circNLN, showed consistent differential expression in ferroptosis non-resistant (downregulated) and resistant (upregulated) cells after cystine-depletion treatment. The knockdown of these circRNAs decreased the viability, invasion, migration, and colony formation ability of PDAC cells. Simultaneously, lipid peroxidation and intracellular iron levels, which are ferroptosis markers, were increased. Additionally, bioinformatic analysis of these circRNAs demonstrated their possible interaction with proteins and miRNAs with reported ferroptosis-related functions. In summary, these findings suggest that circPPP2R2B, circNDUFAB1, and circNLN may be critically involved in PDAC progression and the evasion of ferroptosis which supports the further investigation of their oncogenic and ferroptosis-related action mechanism to propose a potential target for anticancer therapies. Citation Format: Jessica Jazmin Pena Paladines, Shao Weng Wang, Chi Hin Wong, Yang Chao Chen. Identification of circular RNAs associated with the ferroptosis of pancreatic cancer cells. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3801.