Article Text
Abstract
Objectives: Epithelial ovarian cancer (EOC) can be classified into 5 major histological types. Among them, clear cell adenocarcinoma (CCC) has a poor response to chemotherapy and poor prognosis compared with other histological types. Previously, we reported that the hypoxia-inducible protein 2 (HIG2) gene might be a new biomarker for CCCs, based on its expression profile. In this study, we generated a polyclonal antiserum to HIG2 to explore the use of HIG2 as a predictive biomarker in EOC. In addition, HIG2 expression was evaluated in uterine endometrial and renal CCCs.
Methods: Hypoxia-inducible protein 2 expression was analyzed by immunohistochemistry in formalin-fixed surgical samples from 254 EOC, 17 endometrial, and 29 renal CCC patients.
Results: Hypoxia-inducible protein 2 is expressed in 175 of 254 ovarian cancer cases. Cytoplasmic HIG2 expression is significantly more frequent in ovarian CCC (83.1%) than in serous (54.9%, P = 0.0001), mucinous (40%, P = 0.00002), or endometrioid (58.1%, P = 0.003) adenocarcinoma. The chemoresponse rate was higher in 24 ovarian CCC patients with cytoplasmic HIG2 expression than in 6 CCC patients without HIG2 expression (62.5% [15/24] vs 0% [0/6], P = 0.02). In contrast, there was no relationship between nuclear HIG2 expression and chemoresponse. Cytoplasmic and nuclear HIG2 expressions are significantly more frequent in ovarian and uterine than renal CCC (P = 0.04).
Conclusions: Hypoxia-inducible protein 2 may be used as a marker for early detection of ovarian CCCs or for prediction of response to chemotherapy, but HIG2 expression does not predict survival of patients with CCC.
- Ovary
- Clear cell adenocarcinoma
- Kidney
- Endometrium
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Footnotes
This study was supported in part by a grant from Osaka City General Hospital; a grant-in-aid for Scientific Research on Priority Areas from the Ministry of Education, Science and Culture, Japan (20014024, Keio University); a grant-in-aid from Kurokawa Cancer Research Foundation; a grant-in-aid from the Ministry of Health, Labor and Welfare, Japan; and a 21st Century COE Program special research grant (Tohoku University) from the Ministry of Education Science, Sports and Culture, Japan.
The authors have no conflicts of interest to declare.