Alternative TrkAIII splicing: a potential regulated tumor-promoting switch and therapeutic target in neuroblastoma

• Published in: Future oncology (London, England) Vol. 1; no. 5; p. 689
• Main Authors: Tacconelli, Antonella, Farina, Antonietta R, Cappabianca, Lucia, Gulino, Alberto, Mackay, Andrew R
• Format: Journal Article
• Language: English
• Published: England 01-10-2005
• Subjects: Alternative Splicing - genetics; Animals; Gene Expression Regulation, Neoplastic; Humans; Neuroblastoma - genetics; Neuroblastoma - metabolism; Neuroblastoma - pathology; Receptor, trkA - antagonists & inhibitors; Receptor, trkA - genetics; Receptor, trkA - metabolism; Signal Transduction
• ISSN: 1479-6694
• DOI: 10.2217/14796694.1.5.689

An association between elevated tyrosine kinase receptor (Trk)-A expression and better prognosis; the absence of mutation-activated TrkA oncogenes; the induction of apoptosis, growth arrest, morphological differentiation and inhibition of xenograft growth; and angiogenesis by TrkA gene transduction, provide the basis for the current concept of an exclusively tumor-suppressor role for TrkA in the aggressive pediatric tumor, neuroblastoma. This concept, however, has recently been challenged by the discovery of a novel hypoxia-regulated alternative TrkAIII splice variant, initial data for which suggest predominant expression in advanced-stage neuroblastoma. TrkAIII exhibits neuroblastoma xenograft tumor-promoting activity associated with the induction of a more angiogenic and stress-resistant neuroblastoma phenotype and antagonises nerve growth factor/TrkAI antioncogenic signaling. In this short review, the authors integrate this novel information into a modified concept that places alternative TrkA splicing as a potential pivotal regulator of neuroblastoma behavior and identifies the TrkAIII alternative splice variant as a potential biomarker of patient prognosis and novel therapeutic target.