Cytogenetic Changes in Renal Neoplasms and During Estrogen-Induced Renal Tumorigenesis in Hamsters

Summary

Cytogenetic changes have been implicated in tumor development. Such changes were studied in male Syrian hamster kidneys after chronic exposure to either diethylstilbestrol(DES) or 17ß-estradiol(E₂). The frequency of aneuploidy and micronuclei was elevated in estrogen-induced renal tumors. The frequency of aneuploidy in DES- and E₂-induced tumors was 8.5-fold and 8.0-fold higher than in untreated kidneys, respectively. The number of micronuclei also increased 3.8-to 4.3-fold in these estrogen-induced tumors. Nonrandom numerical chromosomal abnormalities were +1, +2, +3, +11, +13, +16, +20, +21, and −8, −19, −20 in the DES- and 1, +2, +3, +6, +11, +16, +20, +21, +X and −14,−20 in the E₂-induced tumors. Structural changes were observed only in E₂-induced tumors. Endomitosis, telomeric associations, and breaks were also seen in these kidney tumors. The frequency of chromosomal abnormalities was higher in 3.5 months estrogen-treated hamster proximal tubules after culture. The findings suggest that chronic estrogen exposure induces genetic instability in the hamster kidney and it may be associated with renal tumorigenesis. (NCI, NIH. CA22008)