Li Guidong, Ogose Akira, Kawashima Hiroyuki, Umezu Hajime, Hotta Tetsuo, Tohyama Tsuyoshi, Ariizumi Takashi, Endo Naoto
Division of Orthopedic Surgery, Graduate School of Medical and Dental Sciences, Niigata University Hospital, Niigata, Japan.
Cancer Genet Cytogenet. 2009 Jul;192(1):1-9. doi: 10.1016/j.cancergencyto.2009.02.011.
Pleomorphic rhabdomyosarcoma (PRMS) is a rare variant of rhabdomyosarcoma that occurs mostly in adults. A few cytogenetic studies of PRMS have been reported, but no consistent specific chromosome aberrations were detected. We herein report a cytogenetic study of three cases of pleomorphic rhabdomyosarcoma using a conventional G-banded karyotyping analysis. The three cases appeared to exhibit an extremely complex karyotype with numeric and structural rearrangements. Although the three cases displayed several common aberrations, including -2, -4, -9, -13, -14, -15, -19, -21, add(X)(p11), add(1)(q11), add(7)(p11), and add(13)(p11), no recurrent characteristic chromosomal aberrations could be detected. In addition, among these cases and seven other cases of previously reported PRMS, the most frequent chromosomal alterations were -2, -13, -14, -15, -16, and -19. No obviously consistent structural alterations can be found in these 10 PRMS cases, however, thereby suggesting that it is difficult to confirm whether these complex karyotypes correlated with the diagnosis or clinical outcome in PRMS. In this study, we detected MyoD1 and myogenin gene transcripts at the mRNA level in four cases of PRMS together with other soft-tissue sarcomas, including seven cases of malignant fibrous hitiocytoma, five cases of liposacroma, and three cases of leiomyosacroma using a real-time quantitative reverse-transcriptase polymerase chain reaction (RT-PCR) analysis. High-level expressions of MyoD1 and myogenin gene transcripts were determined in all cases of PRMS. In contrast, the other non-PRMS sarcomas showed either no expression or extremely weak expressions for both genes. Our findings suggest that the detections of MyoD1 and myogenin transcripts using real-time quantitative RT-PCR, combined with immunohistochemical stains, are extremely sensitive and useful for the diagnosis of PRMS.
多形性横纹肌肉瘤（PRMS）是横纹肌肉瘤的一种罕见变异类型，主要发生于成年人。已有一些关于PRMS的细胞遗传学研究报道，但未检测到一致的特异性染色体畸变。我们在此报告3例多形性横纹肌肉瘤的细胞遗传学研究，采用传统的G显带核型分析。这3例病例似乎呈现出具有数目和结构重排的极其复杂的核型。尽管这3例病例表现出一些共同的畸变，包括-2、-4、-9、-13、-14、-15、-19、-21、add(X)(p11)、add(1)(q11)、add(7)(p11)和add(13)(p11)，但未检测到复发性特征性染色体畸变。此外，在这些病例以及其他7例先前报道的PRMS病例中，最常见的染色体改变是-2、-13、-14、-15、-16和-19。然而，在这10例PRMS病例中未发现明显一致的结构改变，因此表明难以确定这些复杂核型是否与PRMS的诊断或临床结果相关。在本研究中，我们使用实时定量逆转录聚合酶链反应（RT-PCR）分析，在4例PRMS病例以及其他软组织肉瘤中检测了MyoD1和肌细胞生成素基因转录本的mRNA水平，其他软组织肉瘤包括7例恶性纤维组织细胞瘤、5例脂肪肉瘤和3例平滑肌肉瘤。在所有PRMS病例中均检测到MyoD1和肌细胞生成素基因转录本的高水平表达。相比之下，其他非PRMS肉瘤对这两个基因均无表达或表达极其微弱。我们的研究结果表明，使用实时定量RT-PCR检测MyoD1和肌细胞生成素转录本，并结合免疫组织化学染色，对PRMS的诊断极其敏感且有用。
