The polymorphic CAG repeat in the androgen receptor gene in Jewish Israeli women with endometrial carcinoma.

Abstract

Endometrial carcinoma is considered a hormonal-dependent tumor; estrogen induces endometrial cellular proliferation, whereas progestins display an antiproliferative effect on endometrial tissue. The role that androgen and its receptor (androgen receptor [AR]) play in the pathogenesis of endometrial carcinoma is less clear. Although androgen has an in vitro inhibitory effect on endometrial cell proliferation, up to 75% of endometrial carcinoma express AR somatically. A polymorphic CAG repeat within exon 1 of the AR encodes for a polyglutamine tract, with length range of 8 to 33 repeats, which is inversely correlated with the transcriptional activity of the AR. To gain insight into the role of AR in endometrial carcinoma, the authors analyzed the polymorphic CAG repeat in 79 Jewish Israeli patients with endometrial carcinoma as compared with 44 healthy Jewish women serving as controls. Analysis was conducted using germline DNA as template and using polymerase chain reaction primers flanking the CAG repeat with subsequent fluorescent determination of allele sizes. Allele size range of the longer of the two alleles in the patients was 11-33 (mean, 19.8 +/- 2.7) and in the controls 10-22 (mean, 17.9 +/- 1.9), a statistically significant difference (P < 0.01). Allele size variation within the patient group did not correlate with disease stage, grade, reproductive history, or age at diagnosis. The authors conclude that AR-CAG repeat length differs in Jewish patients with endometrial carcinoma as compared with healthy individuals in Israel, and this finding increases the possibility that the AR is involved in the predisposition to this neoplasm.