Genomic characterization of a PPP1CB-ALK fusion with fusion gene amplification in a congenital glioblastoma.

Cancer genetics 2021 Apr

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ALK (Anaplastic lymphoma kinase) fusion proteins are oncogenic and have been seen in various tumors. PPP1CB-ALK fusions are rare but have been reported in a few patients with low- or high-grade gliomas. However, little is known regarding the mechanism of fusion formation and genomic break points of this fusion. We performed genomic characterization of a PPP1CB-ALK fusion with fusion gene amplification in a congenital glioblastoma. The PPP1CB-ALK consists of exons 1-5 of PPP1CB and exons 20-29 of ALK. The genomic translocation breakpoints were determined by real-time quantitative PCR (RT-qPCR) and Sanger sequencing of genomic DNA. Next generation sequencing, RT-qPCR and fluorescence in situ hybridization analyses demonstrated PPP1CB-ALK amplification. Copy number analyses of genes between PPP1CB and ALK using RT-qPCR suggest that the PPP1CB-ALK is likely the result of local chromothripsis followed by episomal amplification. Transcriptome sequencing demonstrated high-level SOX2 expression and predicted WNT/β-catenin pathway activation, suggesting possible therapeutic approaches. Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.

Citation

Yiming Zhong, Fumin Lin, Feng Xu, Jeff Schubert, Jinhua Wu, Luanne Wainwright, Xiaonan Zhao, Kajia Cao, Zhiqian Fan, Jiani Chen, Shih-Shan Lang, Benjamin C Kennedy, Angela N Viaene, Mariarita Santi, Adam C Resnick, Phillip B Storm, Marilyn M Li. Genomic characterization of a PPP1CB-ALK fusion with fusion gene amplification in a congenital glioblastoma. Cancer genetics. 2021 Apr;252-253:37-42