Abstract P6-10-29: Circular RNAs in exosomes derived from breast cancer: Promising biomarkers for diagnosis and prognosis of triple negative breast cancer (TNBC)

Abstract

Abstract Background: With the recent development of transcriptome sequencing technology, circular RNAs (circRNAs) have attracted extensive attention from researchers. Exosomes are usually recognized as a type of membrane vesicles containing RNA (mRNA, miRNA, circRNAs and other non-coding RNAs), proteins and lipids, and may be used as promising biomarkers for disease diagnosis. Unfortunately, circRNAs still remains many action mechanisms of circRNAs cannot be understood completely in the process of tumor development. The study aims to explore novel circRNAs and their potential functions in the treatment and progonsis of TNBC.Materials & methods: A combinative strategy of RNA-sequencing (RNA-seq) technique, RT-qPCR and bioinformatic analysis was employed to unearth the potential mechanism of differential circRNAs in serum-exosomes (n=20) and tissues (n=20) from TNBC patients.Results: Combination of the two datasets from differential circRNAs in serum-exosomes and tissues, the result showed that three circRNAs (has-circRNA-LPXN, has-circRNA-NUFIP2 and has-circRNA-HSDL2) were significantly differentially-expressed in both datasets. RT-qPCR used to verify these three circRNAs in cells and serum-exosomes also found has-circRNA-LPXN was down-regulated and has-circRNA-HSDL2 was up-regulated, which was valuable for breast cancer diagnosis by analyzing these circRNAs in serum-exosomes from BCa patients compared with healthy people. Conclusion: The expression levels of has-circRNA-LPXN and has-circRNA-HSDL2 were found significantly different both in serum-exosomes and tissues of TNBC and these circRNAs might function as competing endogenous RNAs and play vital roles in the development of TNBC. More importantly, we constructed two circRNAs-miRNAs networks and provided new insight into prognosis and therapy of TNBC from circRNAs in the serum-exosomes. Citation Format: Sujin Yang, Jinhai Tang. Circular RNAs in exosomes derived from breast cancer: Promising biomarkers for diagnosis and prognosis of triple negative breast cancer (TNBC) [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P6-10-29.