Overexpression of CEACAM6 in borderline and invasive mucinous ovarian neoplasms.
OBJECTIVE
Identifying markers specific for mucinous ovarian neoplasms (MON) is important for cancer diagnosis and surveillance, and will help improve our general understanding of the pathobiology of these tumors. CEACAM6 overexpression appears to be an early molecular event with prognostic significance in gastrointestinal carcinomas. Microarray analysis previously demonstrated high CEACAM6 overexpression in MON's and this study sought to validate this finding.


METHODS
Western blot compared CEACAM6 expression in normal human ovarian surface epithelium (HOSE) and ovarian cancer cell lines. Quantitative RT-PCR (qRT-PCR) was performed on 75 laser-microdissected HOSE and ovarian cancer tissue samples. Immunohistochemistry (IHC) was performed and slides were analyzed in a semi-quantitative manner.


RESULTS
CEACAM6 was expressed in 2 of 3 mucinous cancer cell lines. Expression was absent in all 2 HOSE, 7 serous cancer, and 2 clear cell cancer cell lines. 100-fold CEACAM6 overexpression (qRT-PCR) was demonstrated in 13/16 (81%) borderline, low-grade, and high-grade invasive MON's, compared to 5/50 (10%) serous and 1/5 (20%) benign mucinous samples. CEACAM6 expression was not different between borderline and invasive MON's (p=0.55) or across tumor stage (p=0.76). CEACAM6 staining was present in 24/28 (86%) borderline, low-grade, and high-grade invasive MON's; 13/28 (46%) exhibited moderate-strong staining. Neither CEACAM6 expression (p=0.36) nor staining intensity (p=0.51) was different between borderline and invasive MON's. None of the serous or benign mucinous tumors exhibited CEACAM6 staining.


CONCLUSIONS
CEACAM6 is overexpressed in borderline and invasive MON's.
Litkouhi
Behrang
B
Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Piscataway, NJ, USA.
Litkouhi
Babak
B
Fleming
Evelyn
E
Welch
William R
WR
Berkowitz
Ross S
RS
Birrer
Michael J
MJ
Mok
Samuel C
SC
D000230:Adenocarcinoma / Q000378:metabolism; D002288:Adenocarcinoma, Mucinous / Q000378:metabolism* / Q000473:pathology*; D015703:Antigens, CD / Q000378:metabolism*; D015153:Blotting, Western; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D045744:Cell Line, Tumor; D018284:Cystadenocarcinoma, Serous / Q000378:metabolism; D004848:Epithelium / Q000378:metabolism; D005260:Female; D058851:GPI-Linked Proteins; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D009361:Neoplasm Invasiveness; D010051:Ovarian Neoplasms / Q000378:metabolism* / Q000473:pathology*; D010053:Ovary / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013194:Staining and Labeling; D015854:Up-Regulation
D015703:Antigens, CD; C504117:CEACAM6 protein, human; D015815:Cell Adhesion Molecules; D058851:GPI-Linked Proteins