Szollosi Zoltan, Scholtz Beata, Egervari Kristof, Nemes Zoltan
Department of Pathology, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary.
J Clin Pathol. 2007 Feb;60(2):190-4. doi: 10.1136/jcp.2006.037200. Epub 2006 May 26.
Recent cytogenetic studies have shown that reciprocal translocation t (17;22)(q22;q13) and a supernumerary ring chromosome derived from the translocation r(17;22) are highly characteristic of dermatofibrosarcoma protuberans (DFSP). The chromosomal rearrangements fuse the collagen type Ialpha1 (COL1A1) and the platelet-derived growth factor B-chain (PDGFB) genes. The COL1A1-PDGFB fusion transcript has been shown not only in conventional DFSP but also in a small series of DFSP with fibrosarcomatons areas (DFSP-FS) using reverse transcriptase-based conventional polymerase chain reaction. Nothing is known about the status of the COL1A1-PDGFB chimaeric gene in the pleomorphic areas of DFSP-PleoSarc (formerly known as DFSP-malignant fibrous sarcoma).
To show the COL1A1-PDGFB fusion transcript in transformed malignant fibrous histiocytoma.
A real-time polymerase chain reaction assay for the COL1A1-PDGFB fusion transcript in a series of DFSP containing sarcoma was conducted to determine whether the chimaeric gene could be identified in both components of DFSP-FS and DFSP-PleoSarc. Eight cases were analysed.
In seven cases, transcriptable RNA was detected, and in these cases, translocations were found between COL1A1 and PDGFB genes involving exons 27, 32, 34, 40 and 47 of the COL1A1 gene and exon 2 of the PDGFB gene.
From a diagnostic aspect, this assay can be particularly useful in confirming the diagnosis of sarcomatous DFSP. On the other hand, the COL1A1-PDGFB fusion gene was shown in three cases of DFSP containing pleomorphic sarcoma, which supports the theory of the common histogenesis.
近期的细胞遗传学研究表明，相互易位t(17;22)(q22;q13)以及源自该易位的额外环状染色体r(17;22)是隆突性皮肤纤维肉瘤（DFSP）的高度特征性表现。染色体重排使I型胶原α1（COL1A1）基因与血小板衍生生长因子B链（PDGFB）基因融合。使用基于逆转录的常规聚合酶链反应，不仅在传统的DFSP中，而且在一小部分具有纤维肉瘤区域的DFSP（DFSP-FS）中均已发现COL1A1-PDGFB融合转录本。关于COL1A1-PDGFB嵌合基因在多形性隆突性皮肤纤维肉瘤（DFSP-PleoSarc，原称为DFSP-恶性纤维肉瘤）的多形性区域中的状态尚无相关报道。
在转化的恶性纤维组织细胞瘤中显示COL1A1-PDGFB融合转录本。
对一系列包含肉瘤的DFSP进行COL1A1-PDGFB融合转录本的实时聚合酶链反应检测，以确定在DFSP-FS和DFSP-PleoSarc的两个组成部分中是否都能鉴定出嵌合基因。共分析了8例病例。
7例检测到可转录的RNA，在这些病例中，发现COL1A1基因与PDGFB基因之间存在易位，涉及COL1A1基因的外显子27、32、34、40和47以及PDGFB基因的外显子2。
从诊断角度来看，该检测对于确诊肉瘤样DFSP可能特别有用。另一方面，在3例包含多形性肉瘤的DFSP中发现了COL1A1-PDGFB融合基因，这支持了共同组织发生学的理论。
