IMUP-1 and IMUP-2 genes are up-regulated in human ovarian epithelial tumors.
BACKGROUND
Normal cells lose their ability to divide after a finite number of cell divisions. Under the influence of Simian virus 40 (SV 40) large T-antigen, which interacts with the cell cycle regulators p53 and pRb, cells enter a phase of an extended pre-immortalized cells. Immortalization-up-regulated protein 1 (IMUP-1) and immortalization-up-regulated protein 2 (IMUP-2) genes have been recently cloned and are known to be involved in SV40-mediated immortalization. However, the roles of IMUP-1 and IMUP-2 are not known in human ovarian epithelial tumors.


METHODS
This study was performed to determine mRNA expression and intracellular localization of the IMUP-1 and IMUP-2 in ovarian epithelial tumors by RT-PCR and immunohistochemical staining using human IMUP-1 and IMUP-2 monoclonal antibodies.


RESULTS
IMUP-1 (4.0-fold) and IMUP-2 (2.4-fold) mRNA expression in ovarian epithelial tumors were significantly higher than in normal ovarian tissues (p < 0.05). The mRNAs of IMUP-1 and IMUP-2 in the ovarian cancer cell lines were about 4.9- and 2.9-fold compared to the normal ovarian cell line, respectively. The subcellular expression of these two proteins in immunohistochemical stains was detected mainly in the nucleus of tumor cells, whereas adjacent normal ovarian stromal cells were faintly or negatively stained with these proteins. However, the staining intensity of IMUP-1 and IMUP-2 in ovarian epithelial tumors were not different between histological types or grades.


CONCLUSIONS
These results showed the up-regulation of IMUP-1 and IMUP-2 in human ovarian epithelial tumors and suggested that the altered mRNA level of these molecules is possibly associated with ovarian tumorigenesis.
Graduate School of Life Science and Biotechnology, College of Medicine, Pochon CHA University, Seoul 135-081, South Korea.
Jin Kyeoung
JK
Kim
Hee Jung
HJ
An
Nam Keun
NK
Kim
Jung Yong
JY
Ahn
Kye Seong
KS
Kim
You Jung
YJ
Kang
Jung Jae
JJ
Ko
Doyeun
D
Oh
Chan
C
Lee
Seung Jo
SJ
Kim
Kwang Yul
KY
Cha
D002277:Carcinoma / Q000235:genetics*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics*; D006801:Humans; D007150:Immunohistochemistry; D009687:Nuclear Proteins / Q000235:genetics*; D010051:Ovarian Neoplasms / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000235:genetics*; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured
C439765:C19orf33 protein, human; D009687:Nuclear Proteins; D012333:RNA, Messenger; D014157:Transcription Factors