A case of interdigitating dendritic cell sarcoma studied by whole-exome sequencing
Interdigitating dendritic cell sarcoma (IDCS) is an aggressive neoplasm and is an extremely rare disease, with a challenging diagnosis. Etiology of IDCS is also unknown and most studies with only case reports. In our case, immunohistochemistry showed that the tumor cells were positive for S100, CD45, and CD68, but negative for CD1a and CD21. This study aimed to investigate the causative factors of IDCS by sequencing the protein-coding regions of IDCS. We performed whole-exome sequencing with genomic DNA from blood and sarcoma tissue of the IDCS patient using the Illumina Hiseq 2500 platform. After that, we conducted Sanger sequencing for validation of sarcoma-specific variants and gene ontology analysis using DAVID bioinformatics resources. Through comparing sequencing data of sarcoma with normal blood, we obtained 15 nonsynonymous single nucleotide polymorphisms (SNPs) as sarcoma-specific variants. Although the 15 SNPs were not validated by Sanger sequencing due to tumor heterogeneity and low sensitivity of Sanger sequencing, we examined the function of the genes in which each SNP is located. Based on previous studies and gene ontology database, we found that POLQ encoding DNA polymerase theta enzyme and FNIP1 encoding tumor suppressor folliculin-interacting protein might have contributed to the IDCS. Our study provides potential causative genetic factors of IDCS and plays a role in advancing the understanding of IDCS pathogenesis.
KeywordsInterdigitating dendritic cell sarcoma Whole-exome sequencing POLQ FNIP1
This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2017R1C1B5017565).
Compliance with ethical standards
Conflict of interest
Ki Hwan Hong, Soyoung Song, Wonseok Shin, Keunsoo Kang, Chun-Sung Cho, Yong Tae Hong, Kyudong Han, and Jeong Hwan Moon declare that we have no conflict of interest.
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee.
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