Rma. Aljehani et al., LOSS OF HETEROZYGOSITY ON CHROMOSOME ARMS 5Q, 11P, 11Q, 13Q, AND 16P IN HUMAN TESTICULAR GERM-CELL TUMORS, Genes, chromosomes & cancer, 13(4), 1995, pp. 249-256
To identify common regions of deletion in human testicular germ cell t
umors (TGCTs), we have screened tumors from 33 patients for loss of he
terozygosity (LOH) using Southern blot analysis with 39 polymorphic ma
rkers covering 21 chromosome arms. Losses in more than 2 tumors and oc
curring at a frequency of >10% were found on chromosome arms 5q, 11p,
11q, 13q, and 16p, the highest being on chromosome arm 5q (19%). It is
suggested that tumor suppressor genes on 5q among others may be invol
ved in testicular tumorigenesis and that LOH in this region requires f
urther investigation. No losses were found on 12q and 17p despite the
fact that the most common cytogenetic abnormality in TGCTs is an i(12p
) and that the TP53 gene on 17p is the most frequently mutated gene in
human cancers. The level of allelic imbalance varied considerably fro
m one chromosome region to another (0-80%) and did not generally refle
ct the pattern of LOH. It tended to be high in overrepresented regions
of the genome, 1q, 7p, and 12p. The tumor from one patient had a semi
nomatous component and a less differentiated component. We provide evi
dence for a common origin of both components and show that it is likel
y that this tumor has progressed from the seminoma to the less differe
ntiated histology. (C) 1995 Wiley-Liss, Inc.