HOXA10 expression in endometrial adenocarcinoma

Homeobox (HOX) genes are highly evolutionarily conserved regulators of embryonic differentiation. HOX genes are also expressed in normal adult reproductive tissue where they are involved in regulating differentiation. We hypothesized that HOXA10 gene expression may be altered in endometrial adenocarcinoma. To assess HOXA10 gene expression, endometrial tissue was obtained from 32 subjects with normal endometrium or disease confined to the uterus. Nine specimens contained normal endometrium, 5 had endometrial hyperplasia and 18 had stage I and II endometrial adenocarcinoma. RNA was extracted, Northern blot analysis performed and expression of HOXA10 assessed by densitometry. Expression of estrogen receptor, progesterone receptor and p53 was analyzed by immunohistochemistry. HOXA10 was expressed in both normal and neoplastic endometrium. No significant difference in HOXA10 expression was found between normal, hyperplastic and FIGO nuclear grade 1 endometrial tissues. Expression of HOXA10 was increased by 25% in high nuclear grade endometrial adenocarcinomas compared with normal, hyperplastic and low nuclear grade endometrial adenocarcinomas. No difference was noted in expression of estrogen receptor, progesterone receptor or p53. HOXA10 expression is elevated in high nuclear grade stage I and II endometrial adenocarcinomas. Aberrant regulation of HOX gene expression is associated with abnormal differentiation of endometrial tissue.