PiwiRNA-651 as marker of treatment response and survival in classical Hodgkin lymphoma

// Anna Cordeiro 1 , Alfons Navarro 1 , Anna Gaya 2 , Marina Díaz-Beyá 2 , Blanca Gonzalez-Farré 3 , Joan Josep Castellano 1 , Dolors Fuster 1 , Carmen Martínez 2 , Antonio Martínez 3 , Mariano Monzó 1 1 Molecular Oncology and Embryology Laboratory, Human Anatomy Unit, School of Medicine, University of Barcelona, IDIBAPS, Barcelona, Spain 2 Hematology Department, Hospital Clinic Barcelona, IDIBAPS, Barcelona, Spain 3 Hematopathology Section, Hospital Clinic Barcelona, IDIBAPS, Barcelona, Spain Correspondence to: Alfons Navarro, email: anavarroponz@ub.edu Keywords: Hodgkin lymphoma, non-coding RNAs, piwiRNAs, piR-651, Piwi proteins Received: March 04, 2016 Accepted: May 26, 2016 Published: June 14, 2016 ABSTRACT PiwiRNAs, small non-coding RNAs processed by Piwi proteins, are involved in maintaining genome stability in germline cells. Recently, piwiRNA expression has been identified in some tumors. We have examined the potential reactivation of the Piwi/piwiRNA pathway in classical Hodgkin lymphoma (cHL). We found that Piwi proteins and three selected piwiRNAs, including piR-651, were expressed in cHL patients and cell lines, indicating that the Piwi/piwiRNA pathway is active in cHL. Interestingly, low levels of piR-651 were associated with lack of complete response to first-line treatment, as well as shorter disease-free and overall survival in a cohort of 94 cHL patients. At diagnosis, piR-651 was underexpressed in cHL serum samples compared to healthy controls, while after complete remission, piR-651 levels increased to levels similar to healthy controls. This is the first evidence that piwiRNAs are active in tumor and serum samples and impact prognosis in cHL.