Geurts van Kessel A, Suijkerbuijk R F, Sinke R J, Looijenga L, Oosterhuis J W, de Jong B
Department of Human Genetics, University Hospital, Nijmegen, The Netherlands.
Eur Urol. 1993;23(1):23-8; discussion 29. doi: 10.1159/000474566.
Human testicular germ cell tumours (TGCTs) comprise a heterogeneous group of solid neoplasms. These tumours are characterized by a highly specific chromosomal anomaly, i.e. an isochromosome of the short arm of chromosome 12. At present, this i(12p) chromosome has been observed in about 80% of TGCTs. Also in dysgerminomas of the ovary and in some extragonadal germ cell tumours i(12p) has been observed. In the remaining so-called i(12p)-negative tumours other cytogenetic abnormalities can be found. In addition, TGCTs are usually highly aneuploid. The exact nature and role of these different anomalies in tumour development are as yet undefined. Here we present a molecular cytogenetic analysis of a diverse group of gonadal and extragonadal germ cell tumours. Our results indicate that all tumours examined exhibit anomalies involving 12p [i(12p) and/or others], resulting in a distinct overrepresentation of short arm sequences. Thus, we argue that the occurrence of 12p abnormalities may be a characteristic of both i(12p)-positive and -negative TGCTs and that these abnormalities may, through similar mechanisms, contribute to the process of TGCT development. This notion is substantiated by our finding that in all cases the supernumerary 12p sequences are of uniparental origin.
人类睾丸生殖细胞肿瘤（TGCTs）是一组异质性实体肿瘤。这些肿瘤的特征是存在一种高度特异性的染色体异常，即12号染色体短臂的等臂染色体。目前，在约80%的TGCTs中观察到了这种12号染色体短臂等臂染色体（i(12p)）。在卵巢无性细胞瘤和一些性腺外生殖细胞肿瘤中也观察到了i(12p)。在其余所谓的i(12p)阴性肿瘤中，可以发现其他细胞遗传学异常。此外，TGCTs通常具有高度的非整倍体性。这些不同异常在肿瘤发生发展中的确切性质和作用尚未明确。在此，我们对一组多样的性腺和性腺外生殖细胞肿瘤进行了分子细胞遗传学分析。我们的结果表明，所有检测的肿瘤都表现出涉及12号染色体短臂的异常（i(12p)和/或其他异常），导致短臂序列明显过度代表。因此，我们认为12号染色体短臂异常的出现可能是i(12p)阳性和阴性TGCTs的共同特征，并且这些异常可能通过相似的机制促进TGCT的发生发展过程。我们的这一观点得到了以下发现的证实：在所有病例中，额外的12号染色体短臂序列均来自单亲。
