Abstract 966: Circulating exosomal miRNAs as potential biomarker in liposarcoma

Abstract

Abstract Liposarcoma (LPS) is the most common soft tissue sarcoma histological subtype. Despite the development of combined modality treatments in recent years, a significant proportion of patients respond poorly to chemotherapy, leading to local recurrence or distant metastasis. Thus, early detection of recurrent or metastatic disease or early decision making could improve patient prognosis. However, there are no useful biomarkers for these purposes. Thus, the discovery of novel biomarkers to detect tumors, predict their drug sensitivity, and monitor their progression is one of the most important challenges that must be overcome. miRNAs are short (approximately 22 nucleotides in length) non-coding RNAs (ncRNAs) that regulate gene expression by binding to specific mRNA targets and promoting their degradation and/or translational inhibition; since their discovery in body fluids (secreted in cell-borne membrane vesicles or associated with macromolecular complexes), circulating blood-borne microRNAs are being investigated as potent minimally invasive biomarkers of several diseases including tumors. In this study, our goal is to identify potential biomarkers in the peripheral blood of LPS patients that could be useful for LPS diagnostic, prognostic and therapeutic purposes. To determine the miRNA expression profiles of LPS in peripheral blood (PB) and in peripheral blood exosomes (PBX), a series of 16 human LPS patient specimens and 8 healthy controls was analyzed on a miRNA microarray platform capable of detecting 800 human miRNAs (nCounter Human microRNA expression Assay Nanostring v3). Validation of the array was performed by qRT-PCR on a new set of samples (10 human LPS and 9 healthy controls). To identify differentially expressed miRNAs, we compared miRNAs expression profiles from PBX of 15 patients to 8 healthy samples. A total of 26 miRNAs were significantly upregulated and 3 miRNAs were significantly down regulated (p<0.004). When we compared miRNA expression profiles from PB to healthy controls, fewer miRNAs were consistently deregulated (18 miRNAs were upregulated and 3 miRNAs were downregulated, p<0.02). Moreover the miRNAs found to be consistently deregulated in PB were all also significantly deregulated in the PBX. Validation of the miRNA panel in an independent cohort of LPS patients confirmed this signature. Our study has identified a specific miRNA signature in circulating exosomes that may have a novel role in the diagnosis, prognosis and or treatment of LPS patients in a clinical setting. Citation Format: Lucia Casadei, Chad Creighton, Kara Batte, Dina Chelouche-Lev, Carlo M. Croce, Raphael E. Pollock. Circulating exosomal miRNAs as potential biomarker in liposarcoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 966.