Open Access Research

Differential hRad17 expression by histologic subtype of ovarian cancer

Jennifer L Young2*, E Colin Koon3, Joseph Kwong4, William R Welch5, Michael G Muto1, Ross S Berkowitz1 and Samuel C Mok6

Author Affiliations

1 Division of Gynecologic Oncology, Department of Obstetrics, Gynecology and Reproductive Biology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA

2 Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, Medical University of South Carolina, Charleston, SC, USA

3 Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, Baylor University Medical Center, Dallas, TX, USA

4 Centre for Translational Oncology, Institute of Cancer and the CR-UK Clinical Centre, Barts and the London Queen Mary's School of Medicine and Dentistry, London, UK

5 Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA

6 Department of Gynecologic Oncology, University of Texas MD Anderson Cancer Center, Houston, TX, USA

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Journal of Ovarian Research 2011, 4:6  doi:10.1186/1757-2215-4-6

Published: 30 March 2011

Abstract

Background

In the search for unique ovarian cancer biomarkers, ovarian specific cDNA microarray analysis identified hRad17, a cell cycle checkpoint protein, as over-expressed in ovarian cancer. The aim of this study was to validate this expression.

Methods

Immunohistochemistry was performed on 72 serous, 19 endometrioid, 10 clear cell, and 6 mucinous ovarian cancers, 9 benign ovarian tumors, and 6 normal ovarian tissue sections using an anti-hRad17 antibody. Western blot analysis and quantitative PCR were performed using cell lysates and total RNA prepared from 17 ovarian cancer cell lines and 6 normal ovarian epithelial cell cultures (HOSE).

Results

Antibody staining confirmed upregulation of hRad17 in 49.5% of ovarian cancer cases. Immunohistochemistry demonstrated that only 42% of serous and 47% of endometrioid subtypes showed overexpression compared to 80% of clear cell and 100% of mucinous cancers. Western blot confirmed overexpression of hRad17 in cancer cell lines compared to HOSE. Quantitative PCR demonstrated an upregulation of hRad17 RNA by 1.5-7 fold. hRad17 RNA expression differed by subtype.

Conclusions

hRad17 is over-expressed in ovarian cancer. This over-expression varies by subtype suggesting a role in the pathogenesis of these types. Functional studies are needed to determine the potential role of this protein in ovarian cancer.