Overrepresentation of chromosome 12p sequences and karyotypic evolution in i(12p)-negative testicular germ-cell tumors revealed by fluorescence in situ hybridization.
Human testicular germ-cell tumors (TGCTs) comprise a heterogeneous group of solid neoplasms. These tumors are characterized by the presence of a highly specific chromosomal abnormality, i.e., an isochromosome of the short arm of chromosome 12. At present, this i(12p) chromosome is found in more than 80% of TGCTs. Isochromosome 12p has also been observed in some ovarian and extragonadal germ cell tumors. In the remaining so-called i(12p)-negative TGCTs other abnormalities involving chromosome 12, mainly 12p, can be found. In order to establish whether 12p abnormalities other than i(12p) are a common phenomenon in TGCTs, a panel of 11 i(12p)-negative tumors was investigated using multicolor fluorescence in situ hybridization. All TGCTs examined appeared to contain chromosomal abnormalities involving 12p, resulting in a distinct overrepresentation of short arm sequences. In addition, indications were obtained for a clonal evolution in one of the tumors. Our data suggest that the occurrence of 12p abnormalities is a common phenomenon in i(12p)-negative TGCTs and that these abnormalities, analogous to i(12p), may contribute to the process of tumor development.
Suijkerbuijk
R F
RF
Department of Human Genetics, University Hospital, Nijmegen, The Netherlands.
Sinke
R J
RJ
Meloni
A M
AM
Parrington
J M
JM
van Echten
J
J
de Jong
B
B
Oosterhuis
J W
JW
Sandberg
A A
AA
Geurts van Kessel
A
A
D002869:Chromosome Aberrations; D002871:Chromosome Banding; D002881:Chromosomes, Human, Pair 12 / Q000648:ultrastructure*; D018237:Germinoma / Q000235:genetics*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D008297:Male; D013736:Testicular Neoplasms / Q000235:genetics*; D014178:Translocation, Genetic; D014407:Tumor Cells, Cultured