In situ hybridization analysis of the Y chromosome in gonadoblastoma

✍ Scribed by Razia Sultana; David Myerson; Dr. Christine M. Disteche

• Publisher: John Wiley and Sons
• Year: 1995
• Tongue: English
• Weight: 592 KB
• Volume: 13
• Category: Article
• ISSN: 1045-2257
• DOI: 10.1002/gcc.2870130405

✦ Synopsis

Gonadoblastoma is a rare tumor arising in the streak gonads of about 30% of 46,XY sex-reversed females. Because gonadoblastoma develops only in patiems 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 DYZ I locus on formalin-fixed, parafthembedded sections of tumor samples from four different patients.

After hybridization to DYZl , 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,X146,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.