<i>NTRK</i> Fusions in Central Nervous System Tumors: A Rare, but Worthy Target

• Main Authors: Alessandro Gambella, Rebecca Senetta, Giammarco Collemi, Stefano Gabriele Vallero, Matteo Monticelli, Fabio Cofano, Pietro Zeppa, Diego Garbossa, Alessia Pellerino, Roberta Rudà, Riccardo Soffietti, Franca Fagioli, Mauro Papotti, Paola Cassoni, Luca Bertero
• Format: Article
• Language: English
• Published: MDPI AG 2020-01-01
• Series: International Journal of Molecular Sciences
• Subjects: central nervous system; glioma; pediatric tumors; molecular pathology; ntrk; gene fusion; targeted therapies; precision medicine
• Online Access: https://www.mdpi.com/1422-0067/21/3/753

The neurotrophic tropomyosin receptor kinase (<i>NTRK</i>) genes (<i>NTRK1</i>, <i>NTRK2</i>, and <i>NTRK3</i>) code for three transmembrane high-affinity tyrosine-kinase receptors for nerve growth factors (TRK-A, TRK-B, and TRK-C) which are mainly involved in nervous system development. Loss of function alterations in these genes can lead to nervous system development problems; conversely, activating alterations harbor oncogenic potential, promoting cell proliferation/survival and tumorigenesis. Chromosomal rearrangements are the most clinically relevant alterations of pathological <i>NTRK</i> activation, leading to constitutionally active chimeric receptors. <i>NTRK</i> fusions have been detected with extremely variable frequencies in many pediatric and adult cancer types, including central nervous system (CNS) tumors. These alterations can be detected by different laboratory assays (e.g., immunohistochemistry, FISH, sequencing), but each of these approaches has specific advantages and limitations which must be taken into account for an appropriate use in diagnostics or research. Moreover, therapeutic targeting of this molecular marker recently showed extreme efficacy. Considering the overall lack of effective treatments for brain neoplasms, it is expected that detection of <i>NTRK</i> fusions will soon become a mainstay in the diagnostic assessment of CNS tumors, and thus in-depth knowledge regarding this topic is warranted.