Shanghai Skin Disease Hospital, School of Medicine, Tongji University, Shanghai, China.
Key Laboratory of Pediatric Hematology and Oncology Ministry of Health, Department of Hematology and Oncology, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Exp Mol Pathol. 2021 Oct;122:104672. doi: 10.1016/j.yexmp.2021.104672. Epub 2021 Aug 8.
In most cases, dermatofibrosarcoma protuberans (DFSP) is characterized by the chromosomal translocation t (17; 22) (q22; q13) that leads to a fusion of collagen type 1 alpha 1 (COL1A1) and platelet-derived growth factor beta chain (PDGFB). Recently, next-generation sequencing (NGS) has been reported to detect fusion transcripts in some malignancies. Therefore, the present study aimed to evaluate the utility of the targeted NGS in detecting the COL1A1-PDGFB fusion in patients with DFSP.
We designed a targeted DNA capture panel to tile along the fusion regions, including exon, intron, and untranslated regions of the COL1A1 and PDGFB. A cohort of 18 DNA samples extracted from formalin-fixed, paraffin-embedded tissues was used to evaluate the targeted NGS. The results were compared with that of fluorescence in situ hybridization (FISH).
The COL1A1-PDGFB fusion was identified in 13 of 18 cases (72.2%) by targeted NGS assay. PDGFB breakpoints were constantly found in exon 2, while breakpoints in COL1A1 varied from exon 15 to 46. Of these 18 cases assayed by FISH, 12 (66.7%) exhibited COL1A1-PDGFB fusion signals. One case (P9), which was FISH-negative, was demonstrated with the fusion by targeted NGS and validated by PCR and Sanger sequencing. The targeted NGS results showed a high concordance with the results of the FISH assay (94.4%).
Our study reported a targeted NGS assay for detecting the breakpoints of the COL1A1-PDGFB fusion gene, which can be implemented in diagnosing patients with DFSP.
在大多数情况下，隆突性皮肤纤维肉瘤（DFSP）的特征是染色体易位 t（17；22）（q22；q13），导致胶原 1 型 alpha 1（COL1A1）和血小板衍生生长因子β链（PDGFB）融合。最近，下一代测序（NGS）已被报道可检测一些恶性肿瘤中的融合转录本。因此，本研究旨在评估靶向 NGS 在检测 DFSP 患者中 COL1A1-PDGFB 融合的应用价值。
我们设计了一个靶向 DNA 捕获面板，以沿融合区域进行平铺，包括 COL1A1 和 PDGFB 的外显子、内含子和非翻译区。使用 18 个从福尔马林固定、石蜡包埋组织中提取的 DNA 样本的队列来评估靶向 NGS。结果与荧光原位杂交（FISH）进行比较。
通过靶向 NGS 检测，18 例中的 13 例（72.2%）鉴定出 COL1A1-PDGFB 融合。PDGFB 断点始终位于外显子 2 中，而 COL1A1 的断点则从外显子 15 到 46 不等。在通过 FISH 检测的这 18 例中，12 例（66.7%）显示 COL1A1-PDGFB 融合信号。FISH 阴性的 1 例（P9）通过靶向 NGS 检测到融合，并通过 PCR 和 Sanger 测序进行验证。靶向 NGS 结果与 FISH 检测结果高度一致（94.4%）。
我们的研究报告了一种用于检测 COL1A1-PDGFB 融合基因断点的靶向 NGS 检测方法，可用于诊断 DFSP 患者。
