A loss-of-function genetic screening identifies novel mediators of thyroid cancer cell viability

// Maria Carmela Cantisani 1 , Alessia Parascandolo 2 , Merja Perälä 3, 4 , Chiara Allocca 2 , Vidal Fey 3, 4 , Niko Sahlberg 3, 4 , Francesco Merolla 5 , Fulvio Basolo 6 , Mikko O. Laukkanen 1 , Olli Pekka Kallioniemi 7 , Massimo Santoro 2, 8 , Maria Domenica Castellone 8 1 IRCCS SDN, Naples, Italy 2 Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Universita’ Federico II, Naples, Italy 3 Medical Biotechnology, VTT Technical Research Centre of Finland, Turku, Finland 4 Center for Biotechnology, University of Turku, Turku, Finland 5 Dipartimento di Scienze Biomediche Avanzate, Università Federico II, Naples, Italy 6 Division of Pathology, Department of Surgery, University of Pisa, Pisa, Italy 7 FIMM-Institute for Molecular Medicine Finland, University of Helsinki, Helsinki, Finland 8 Istituto di Endocrinologia ed Oncologia Sperimentale “G. Salvatore” (IEOS), C.N.R., Naples, Italy Correspondence to: Maria Domenica Castellone, e-mail: mcastell@unina.it Keywords: kinases, screening, siRNA, thyroid carcinoma Received: October 01, 2015 Accepted: March 02, 2016 Published: April 4, 2016 ABSTRACT RET, BRAF and other protein kinases have been identified as major molecular players in thyroid cancer. To identify novel kinases required for the viability of thyroid carcinoma cells, we performed a RNA interference screening in the RET/PTC1(CCDC6-RET)-positive papillary thyroid cancer cell line TPC1 using a library of synthetic small interfering RNAs (siRNAs) targeting the human kinome and related proteins. We identified 14 hits whose silencing was able to significantly reduce the viability and the proliferation of TPC1 cells; most of them were active also in BRAF-mutant BCPAP (papillary thyroid cancer) and 8505C (anaplastic thyroid cancer) and in RAS-mutant CAL62 (anaplastic thyroid cancer) cells. These included members of EPH receptor tyrosine kinase family as well as SRC and MAPK (mitogen activated protein kinases) families. Importantly, silencing of the identified hits did not affect significantly the viability of Nthy-ori 3-1 (hereafter referred to as NTHY) cells derived from normal thyroid tissue, suggesting cancer cell specificity. The identified proteins are worth exploring as potential novel druggable thyroid cancer targets.