Deciphering the Role of Circular RNAs in the Pathogenesis and Therapy Resistance of ALKpositive Anaplastic Large-cell Lymphoma

Anaplastic large-cell lymphoma (ALCL) is an aggressive T-cell pediatric lymphoma. 85% of ALK+ ALCL cases harbor a fusion between the nucleophosmin (NPM) and anaplastic lymphoma kinase (ALK) genes, leading to a constitutively activated and oncogenic fusion protein. Most ALK+ ALCL cases initially respond well to the frontline chemotherapy, but 30% of patients relapse and are of poor prognosis. Understanding the origins of therapy resistance is of major importance to improve treatment and patient prognosis. Current research highlights deregulated expression of regulatory non-coding RNAs (ncRNAs) as an important factor in therapy resistance. To date, microRNAs and long noncoding RNAs have been linked to therapy resistance in ALK+ ALCL. Circular RNAs (circRNAs) are a class of highly stable noncoding RNAs that have recently come into the focus of researchers. circRNAs can control target gene expression by e.g. interacting with microRNAs or proteins. This project aims to elucidate their role in ALK+ ALCL biology including their impact on noncoding RNA networks and therapy resistance. This project will (1) identify a signature of circRNAs associated with therapy resistance in ALK+ ALCL, (2) analyze their effect on treatment response, (3) elucidate their mechanism of action, and (4) evaluate circRNA candidates as predictive and prognostic plasma biomarkers using liquid biopsies. The goal of the study is to characterize the role of candidate circRNAs in this well-defined cancer type, which can serve as a model for other ALK+ cancers. Project results will add to the current mechanistic understanding of ALK+ ALCL pathogenesis and the origins of therapy resistance, and could define new druggable targets and associated predictive biomarkers for high-risk disease. Establishing the blood-based alternative confirmation for the ALK+ ALCL diagnosis could also produce a less invasive predictive tool capable of longitudinal patient monitoring for early relapse detection.