Detection of novel fusion genes by next-generation sequencing-based targeted RNA sequencing analysis in adenoid cystic carcinoma of head and neck

• Published in: Oral surgery, oral medicine, oral pathology and oral radiology Vol. 132; no. 4; pp. 426 - 433
• Main Authors: Shibata, Eri, Morita, Kei-ichi, Kayamori, Kou, Tange, Shoichiro, Shibata, Hiroki, Harazono, Yosuke, Michi, Yasuyuki, Ikeda, Tohru, Harada, Hiroyuki, Imoto, Issei, Yoda, Tetsuya
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.10.2021
• ISSN: 2212-4403; 2212-4411; 2212-4411
• DOI: 10.1016/j.oooo.2021.03.020

Adenoid cystic carcinoma (AdCC) is a rare, indolent salivary gland tumor that is reported to be driven by fusion genes. However, MYB/MYBL1-NFIB fusions have been detected in <60% of all AdCC cases and the oncogenic driver mutations in approximately 40% of AdCC remain unknown. Our aim was to identify novel gene fusions in AdCC. We investigated 20 AdCC cases using a targeted RNA sequencing panel to identify gene fusions and performed quantitative real-time reverse transcription polymerase chain reaction to assess MYB, MYBL1, and NFIB expression levels. A total of 36 fusion transcripts in 15 cases were detected and validated by Sanger sequencing. The MYB-NFIB and MYBL1-NFIB fusion genes were detected in 9 and 3 cases, respectively, in a mutually exclusive manner. Furthermore, novel gene fusions, namely, NFIB-EPB41L2, MAP7-NFIB, NFIB-MCMDC2, MYBL1-C8orf34, C8orf34-NFIB, and NFIB-CASC20, were identified. Among them, NFIB-EPB41L2 and NFIB-MCMDC2 are thought to activate MYB and MYBL1 expression, respectively, through the insertion of a genomic segment in proximity to MYB and MYBL1 genes, respectively. Six novel gene fusions other than MYB/MYBL1-NFIB were identified. The detection of novel fusion genes and investigation of the molecular mechanism will contribute to the development of novel molecular targeted therapies for this disease.