Conclusions
High expression of ULBP2 is an indicator of poor prognosis in ovarian cancer and may relate to T cell dysfunction in the tumor microenvironment.
Methods
Eighty-two ovarian cancer patients and six patients without ovarian cancer from Department of Obstetrics and Gynecology of Kyoto University Hospital were enrolled in this study between 1993 and 2003. Expression of MICA/B, ULBP2, and CD57 in ovarian cancer tissue and normal ovary tissue was evaluated by immunohistochemical staining, and the relationship of these
Objective
To investigate the clinical significance of the expression of the NKG2D ligands MICA/B and ULBP2 in ovarian cancer.
Results
Expression of MICA/B and ULBP2 was detected in 97.6 and 82.9% of ovarian cancer cells, respectively, whereas neither was expressed on normal ovarian epithelium. The expression of MICA/B in ovarian cancer was highly correlated with that of ULBP2. Strong expression of ULBP2 in ovarian cancer cells was correlated with less intraepithelial infiltration of T cells and bad prognoses for patients, suggesting that ULBP2 expression is a prognostic indicator in ovarian cancer. The expression of NKG2D ligands did not correlate with the levels of the soluble forms of the ligands. Conclusions: High expression of ULBP2 is an indicator of poor prognosis in ovarian cancer and may relate to T cell dysfunction in the tumor microenvironment.