LAUSR

Background; NUT midline carcinoma (NMC) is a rare, highly aggressive tumor with t(15;19) translocation involving NUT midline carcinoma family member 1 (NUTM1) gene. NMC is genetically defined and diagnosed by RNA sequencing or by immunohistochemistry for NUT protein expression instead. However, it can be challenging to perform these assays on small biopsy specimens. We, here, report the utility of digital PCR (dPCR) assay for diagnosis of NMC. Methods; The QuantStudio 3D dPCR system (Thermo Fisher Scientific) was used. We designed optimal dPCR probes for the BRD4-NUT fusion gene and evaluated the dPCR method using NMC cell lines (HCC2429 and Ty82) and clinical samples. Total RNA was extracted from the cell lines and FFPE tissue samples from patients with thoracic tumors (RecoverAll total nucleic acid isolation kit, Thermo Fisher Scientific). cDNA was synthesized with SuperScript VILO cDNA kit (Thermo Fisher Scientific). PCR was performed using ProFlex PCR system (Thermo Fisher Scientific). Data was analyzed with QuantStudio 3D AnalysisSuite Cloud Software (Thermo Fisher Scientific). Results; We identified the BRD4-NUT fusion gene in HCC2429 and Ty82 cells using the dPCR system, which allowed us to detect the fusion gene at a prevalence Citation Format: Shunsuke Okumura, Shin-ichi Chiba, Masatoshi Sado, Nana Takahashi, Takaaki Sasaki, Masahiro Kitada, Yoshinobu Ohsaki. Digital PCR in genetic diagnosis of NUT midline carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 648.