Kuroda M, Ishida T, Horiuchi H, Kida N, Uozaki H, Takeuchi H, Tsuji K, Imamura T, Mori S, Machinami R
Department of Pathology, University of Tokyo, Japan.
Am J Pathol. 1995 Nov;147(5):1221-7.
Myxoid liposarcomas have a unique and specific t(12;16)q13;p11) chromosomal translocation. The breakpoint has recently been identified and shown to involve the TLS/FUS gene on chromosome 16 and the CHOP gene on chromosome 12. This translocation causes fusion of these genes resulting in the expression of a novel chimeric TLS/FUS-CHOP message. Using the polymerase chain reaction with primer sets derived from sequences of TLS/FUS and CHOP cDNAs, we could amplify three types of the fusion transcripts from seven of seven samples of myxoid and round cell liposarcomas. In six of the seven positive samples, two kinds of chimeric messenger RNAs were found that have been reported previously. However, the last sample had a novel chimeric message that had an extra sequence of 33 bp derived from the TLS/FUS gene. Thus, it was shown that these fusion transcripts had a varying extent of the sequence of TLS/FUS gene incorporated at the site of the fusion. However, the TLS/FUS-CHOP fusion transcripts were not detected in two pleomorphic liposarcomas or in three myxoid variants of malignant fibrous histiocytomas. Our findings indicate that in liposarcomas TLS/FUS-CHOP fusion transcripts have variations at the junction of chimeric messages, which was the case for Ewing's sarcoma. Detection of the chimeric message by reverse transcription polymerase chain reaction was also suggested to be a useful approach for the diagnosis of myxoid and round cell liposarcomas that have (12;16) translocation, and for distinguishing them from pleomorphic liposarcoma and myxoid variant of malignant fibrous histiocytomas.
黏液样脂肪肉瘤具有独特且特定的t(12;16)(q13;p11)染色体易位。该断点最近已被确定，显示涉及16号染色体上的TLS/FUS基因和12号染色体上的CHOP基因。这种易位导致这些基因融合，从而表达一种新的嵌合TLS/FUS-CHOP信息。使用从TLS/FUS和CHOP cDNA序列衍生的引物对进行聚合酶链反应，我们能够从七个黏液样和圆形细胞脂肪肉瘤样本中的七个样本中扩增出三种类型的融合转录本。在七个阳性样本中的六个样本中，发现了两种先前已报道的嵌合信使RNA。然而，最后一个样本有一种新的嵌合信息，其具有来自TLS/FUS基因的33 bp额外序列。因此，表明这些融合转录本在融合位点处掺入的TLS/FUS基因序列长度不同。然而，在两个多形性脂肪肉瘤或三个恶性纤维组织细胞瘤的黏液样变体中未检测到TLS/FUS-CHOP融合转录本。我们的研究结果表明，在脂肪肉瘤中，TLS/FUS-CHOP融合转录本在嵌合信息的连接处存在变异，尤因肉瘤也是如此。逆转录聚合酶链反应检测嵌合信息也被认为是诊断具有(12;16)易位的黏液样和圆形细胞脂肪肉瘤，并将它们与多形性脂肪肉瘤和恶性纤维组织细胞瘤的黏液样变体区分开来的一种有用方法。
