EML4-ALK translocations are detected in 4-8 % of non-small cell lung cancer (NSCLC). While different EML4-ALK variants are defined by different breakpoints in the EML4 gene, most frequently located in intron 6 or 13, ALK breakpoint is almost invariably in intron 19. Rare reports describe EML4-ALK translocations with breakpoints in intron 17 or intron 18 of the ALK gene. Despite all these ALK breakpoints potentially generate oncogenic fusions, the reasons of this strong imbalance toward intron 19 (exon 20) breakpoints in ALK positive NSCLC are currently unknown. The aim of this study is to investigate the mechanisms that underlie ALK translocation in NSCLC. Our data show that all EML4-ALK fusion variants were equally oncogenic when overexpressed. In contrast, when EML4-ALK variants were generated from the endogenous loci there was a strong selection bias toward ALK fusions originating in intron 19 suggesting that intron 19 variants have the strongest oncogenic potential in lung epitheli..... READ ARTICLE
Cancer Research DOI:10.1158/1538-7445.AM2020-2400
Authors: Giulia C. Leonardi, Taek-Chin Cheong, Chiara Ambrogio, Tao Chen, Wei-Tien Tai, Elif Karaca, Ines Mota, Massimo Libra, Mark M. Awad, Rafael Blasco-Patino and Roberto Chiarle
