Abstract: Objective：To detect the expression level of small ubiquitin-like modifier protein-1 （SUMO-1） and estrogen receptor alpha（ERα）, and their correlation in endometrial carcinoma. Methods：50 cases of endometrial carcinoma samples and 35 cases of normal endometrial samples were collected in our hospital from 2006 January to 2013 December. The expression of SUMO-1 and ERα were detected in all tissues by immunohistochemical method, and their co-localization expression was detected by immunofluorescence method. Then the relationship between SUMO-1 and ERα, and their express level and the clinicopathological parameters were analyzed respectively. Results：The positive rates of SUMO-1 protein in endometrial carcinoma was higher than that in control group, while the expression of ERα protein was the opposite, and the difference between the two groups was statistically significant（Ｐ＜０．０５）. The positive rate of SUMO-1 and ERα in endometrial carcinoma patients were differ in different ages, menopausal status and different histological grades（all P＜0.05）, but the difference was not significant in different pathology subtypes（P＞0.05）. The expression of SUMO-1 and ERα protein had good consistency （Kappa=0.875, Z=5.473, P=0.001）. Conclusions：SUMO-1 and ERα were co-localization in endometrial carcinoma, and may play a synergistic role in the process and development of endometrial carcinoma.

Key words: Carcinoma, Endometrial neoplasms, Estrogen receptor alpha, Small ubiquitin-like modifier protein