Five genes from chromosomal band 8p22 are significantly down-regulated in ovarian carcinoma: N33 and EFA6R have a potential impact on overall survival.
BACKGROUND
Loss of heterozygosity on chromosomal band 8p22 is a common event in several epithelial tumors including ovarian carcinoma. So far, no clear evidence for a tumor suppressor gene (TSG) in this region has been found.


METHODS
On the basis of publicly available expression data in ovarian tissues, the authors selected the eight most noteworthy genes from 8p22 (DLC1, N33, ZDHHC2, FLJ32642, PDGFRL, MTSG1, PCM1, and EFA6R) for a detailed expression analysis in 58 primary ovarian carcinoma tissues and in 38 ovarian cancer cell lines by using quantitative real-time reverse transcriptase-polymerase chain reaction (qRT-PCR). Expression data were correlated to various clinicopathologic characteristics and survival.


RESULTS
Two genes showed a significantly (P< 0.05) lower expression in grade 3 tumors compared with tumors of lower grade (N33) or compared with normal controls and tumors with lower grade (EFA6R). Expression of N33 and EFA6R seems to have an impact on survival, in particular when the combined expression of both genes was used as predictive factor (P< 0.003). In addition, N33 and EFA6R showed a complete loss of expression in several ovarian cancer cell lines. Three genes (FLJ32642, MTSG1, and PCM1) had a significantly (P< 0.001, P< 0.004, and P< 0.001) lower expression in primary ovarian carcinoma compared with controls (ovarian tissues and cysts).


CONCLUSIONS
Two to five new potential tumor suppressor or antagonizing gene candidates (N33 and EFA6R with impact on survival, and potentially FLJ32642, MTSG1, and PCM1) for ovarian carcinoma, were identified from the chromosomal band 8p22 and are promising candidates for further functional analysis in ovarian carcinoma.
Pils
Dietmar
D
Department of Internal Medicine I, Division of Oncology, Medical University of Vienna, Vienna, Austria.
Horak
Peter
P
Gleiss
Andreas
A
Sax
Cornelia
C
Fabjani
Gerhild
G
Moebus
Volker J
VJ
Zielinski
Christoph
C
Reinthaller
Alexander
A
Zeillinger
Robert
R
Krainer
Michael
M
D002871:Chromosome Banding; D002898:Chromosomes, Human, Pair 8; D015536:Down-Regulation / Q000235:genetics*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D009367:Neoplasm Staging; D010048:Ovarian Cysts / Q000235:genetics; D010051:Ovarian Neoplasms / Q000235:genetics* / Q000401:mortality / Q000473:pathology; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D016019:Survival Analysis