Fusion of the COL1A1 and FYN Genes in Epithelioid Osteoblastoma

Abstract

Background/aim: Epithelioid osteoblastoma is a rare benign tumor of the bone. Its pathogenesis is unknown and little is known regarding its genetic features.

Materials and methods: Cytogenetic, RNA sequencing, reverse transcription polymerase chain reaction (RT-PCR), genomic PCR, and Sanger sequencing analyses were performed on an epithelioid osteoblastoma.

Results: G-banding analysis of short-term cultured tumor cells yielded a normal male karyotype in all examined metaphases. RNA sequencing detected a fusion of COL1A1 from 17q21 with FYN from 6q21. Both RT-PCR and genomic PCR together with Sanger sequencing verified the presence of a COL1A1-FYN fusion gene. In the COL1A1-FYN chimeric transcript, exon 43 of COL1A1 was fused to exon 2 of FYN. The genomic junction occurred in introns 43 and 1 of COL1A1 and FYN, respectively.

Conclusion: A COL1A1-FYN fusion gene was found in an epithelioid osteoblastoma resulting in deregulation of FYN. Whether COL1A1-FYN represents a consistent genetic feature of epithelioid osteoblastomas, remains to be seen.

Keywords: COL1A1; COL1A1-FYN fusion gene; Epithelioid osteoblastoma; FYN; RNA sequencing.