J. Gronwald et al., Molecular evidence for derivation of metastatic cells from minor subclonesof primary clear renal cell carcinomas, CANCER DET, 23(6), 1999, pp. 479-484
The production of metastases depends on changes in a large number of genes.
It is also connected with the interaction of tumor cells with the environm
ent. It has been reported that primary tumor clone domination is also an im
portant factor in metastasizing,;md in many neoplasms dominating clones are
the metastatic forerunners. Up to now it is unknown whether domination of
a given clone in a primary renal cell carcinoma is a crucial factor in form
ing metastases or rather presence or absence of specific genes imposes the
major advantage in the metastatic process. To study the presence or absence
of the duplication and mitotic nondisjunction event as one of the phenomen
on in the creation of metastases, as well as possible derivation of metasta
tic cells from the minor subclone of primary tumor, we examined three metas
tatic renal clear-cell carcinomas in which by comparative genomic hybridiza
tion we detected the loss of 3p in the primary tumor and two copies of 3p i
n the corresponding metastasis. Loss of heterozygosity analyses using marke
rs for 3p25 (D3S1038), 3p21.1 (D3S1295), and 3p14.2 (D3S1481) proved hetero
zygosity of at least two 3p loci in all metastatic tumors, which indicates
the absence of mitotic nondisjunction event as a cause of occurrence of two
copies of 3p in metastases. Our results suggest that in some of the clear-
cell renal carcinomas metastatic cells may derive from minor subclones of p
rimary tumors.