Expression of Rsf-1, a chromatin-remodeling gene, in ovarian and breast carcinoma.
Rsf-1 protein is a member of a chromatin-remodeling complex that plays an important role in regulating gene expression and cell proliferation. Our previous study showed that Rsf-1 was an amplified gene that participated in the development of ovarian serous carcinoma. To further elucidate the role of Rsf-1 in ovarian cancer, we studied Rsf-1 immunoreactivity in 294 ovarian tumors of various histologic types. Because the Rsf-1 amplicon overlaps an amplified region reported in breast cancer, we included 782 neoplastic and normal breast tissues for comparison. Immunohistochemistry was performed on tissue microarrays using a 4-tiered scoring system. Overexpression of Rsf-1 was defined as a nuclear immunointensity of 3+ to 4+ because of a strong correlation between 3+ and 4+ immunointensity and Rsf-1 gene amplification, based on our previous fluorescence in situ hybridization analysis. Rsf-1 overexpression was observed in 25% of high-grade ovarian serous carcinomas and in only rare cases (<7%) of low-grade ovarian serous, ovarian endometrioid, and invasive breast carcinomas but not in any ovarian serous borderline tumors, ovarian clear cell carcinomas, ovarian mucinous carcinomas, intraductal carcinomas of the breast, and normal ovaries and breast tissues. Thus, overexpression of Rsf-1 was significantly associated with high-grade ovarian serous carcinoma (P < .05), as compared with other types of ovarian tumors and breast carcinomas. Our results provide evidence that Rsf-1 expression is primarily confined to high-grade serous carcinoma, the most aggressive ovarian cancer. Because Rsf-1 overexpression occurs in only a small number of breast carcinomas, it is unlikely that Rsf-1 is a critical gene in the development of breast carcinoma.
Mao
Tsui-Lien
TL
Department of Pathology, Johns Hopkins Medical Institutions, Baltimore, MD 21231, USA.
Hsu
Chih-Yi
CY
Yen
May J
MJ
Gilks
Blake
B
Sheu
Jim Jinn-Chyuan
JJ
Gabrielson
Edward
E
Vang
Russell
R
Cope
Leslie
L
Kurman
Robert J
RJ
Wang
Tian-Li
TL
Shih
Ie-Ming
IeM
D014408:Biomarkers, Tumor / Q000032:analysis; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D002277:Carcinoma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D042002:Chromatin Assembly and Disassembly / Q000235:genetics; D005260:Female; D005784:Gene Amplification; D006801:Humans; D007150:Immunohistochemistry; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D010051:Ovarian Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*
D014408:Biomarkers, Tumor; D009687:Nuclear Proteins; C452851:RSF1 protein, human; D015534:Trans-Activators