In situ hybridization analysis of the Y chromosome in gonadoblastoma.
Gonadoblastoma is a rare tumor arising in the streak gonads of about 30% of 46,XY sex-reversed females. Because gonadoblastoma develops only in patients who have Y-chromosome material and dysgenetic gonads, it has been hypothesized that positive expression of a gene (or genes) on the Y chromosome (GBY) is involved in the etiology of the tumor. To examine the Y chromosome directly in tumors, we performed nonisotopic in situ hybridization of a biotin-labeled Y-specific probe for the DYZI locus on formalin-fixed, paraffin-embedded sections of tumor samples from four different patients. After hybridization to DYZI, the Y chromosome was found to be present in all gonadoblastoma foci in the four patients studied, and the gonadoblastoma foci showed an average of 85% cell nuclei positive for the Y chromosome on tissue sections. Normal male and female control tissues showed an average of 78% and 0% positive nuclei, respectively. One patient with bilateral gonadoblastoma had previously been shown to be mosaic, with a 45,X/46,XY karyotype in lymphocytes, skin fibroblasts, and cultures from both gonads. Examination of sections of this patient's gonads showed 79% positive nuclei within the gonadoblastoma foci, whereas the nontumor stromal tissue had 19% positive nuclei. These results indicate that, in this mosaic gonad, tumor foci developed only from cells that had a Y chromosome. Our results support the hypothesis that there is a GBY locus on the Y chromosome and that the Y chromosome is retained in the gonadoblastoma foci during the development of the tumor.
Sultana
R
R
Department of Pathology, University of Washington, Seattle 98195, USA.
Myerson
D
D
Disteche
C M
CM
D000293:Adolescent; D016022:Case-Control Studies; D005260:Female; D006061:Gonadal Dysgenesis, 46,XY / Q000235:genetics*; D018238:Gonadoblastoma / Q000235:genetics* / Q000473:pathology; D006801:Humans; D017403:In Situ Hybridization; D008297:Male; D010051:Ovarian Neoplasms / Q000235:genetics / Q000473:pathology; D014424:Turner Syndrome / Q000235:genetics; D014565:Urogenital Neoplasms / Q000235:genetics* / Q000473:pathology; D014998:Y Chromosome / Q000235:genetics*