Comprehensive Molecular Characterization of Adamantinoma and OFD-like Adamantinoma Bone Tumors

Naser M. Ali, Stefania Niada, Mark R. Morris, Anna T. Brini, David Huen, Vaiyapuri Sumathi, Farida Latif

Research output: Contribution to journalArticle

Abstract

Adamantinoma and osteofibrous dysplasia (OFD)-like adamantinoma are rare primary bone tumors that are predominantly confined to the tibia. These 2 entities show similarities in location, histology, and radiologic appearance; however, adamantinoma is malignant and therefore differentiating between these bone tumors is essential for optimal patient care. To elucidate their genomic and transcriptomic alteration profiles and expand their etiological mechanisms, whole exome sequencing (WES) and RNA sequencing (RNA-Seq) were conducted on adamantinoma and OFD-like adamantinoma tumors. Copy number variation analysis using WES data revealed distinct chromosomal alteration profiles for adamantinoma tumors compared with OFD-like adamantinomas, allowing molecular differentiation between the 2 tumor subtypes. Combining WES and copy number variation analyses, the chromatin remodelling-related gene KMT2D was recurrently altered in 3/8 adamantinoma tumors (38%), highlighting the potential involvement of deregulated chromatin structure and integrity in adamantinoma tumorigenesis. RNA-Seq analysis revealed a novel somatic gene fusion (EPHB4-MARCH10) in an adamantinoma, the gene fusion was fully characterized. Hierarchical clustering analysis of RNA-Seq data distinctly clustered adamantinoma tumors from OFD-like adamantinomas, allowing to molecularly distinguish between the 2 entities. David Gene Ontology analysis of differentially expressed genes identified distinct altered pathways in adamantinoma and OFD-like adamantinoma tumors, highlighting the different histopathologic characteristics of these bone tumor subtypes. Moreover, RNA-Seq expression profiling analysis identified elevated expression of DLK1 gene in adamantinomas, serving as a potential molecular biomarker. The present study revealed novel genetic and transcriptomic insights for adamantinoma and OFD-like adamantinoma tumors, allowing to differentiate genetically and transcriptomically between the 2 lesions and identifying a potential diagnostic marker for adamantinomas.

Original languageEnglish
Pages (from-to)965-974
Number of pages10
JournalAmerican Journal of Surgical Pathology
Volume43
Issue number7
DOIs
Publication statusPublished - Jul 1 2019

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Keywords

  • bone tumor
  • CNV
  • gene fusion
  • RNA sequencing
  • whole exome sequencing

ASJC Scopus subject areas

  • Anatomy
  • Surgery
  • Pathology and Forensic Medicine

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