2002 Fiscal Year Final Research Report Summary
Characterization of immortalized human ovarian surface epithelial cells transfected by PTEN expression vectors
| Project/Area Number |
12671616
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Obstetrics and gynecology
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| Research Institution | Kumamoto University |
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Principal Investigator |
KATABUCHI Hidetaka Kumamoto Univ. Sch. of Mat, OB/GYN, Associate Prof., 医学部, 助教授 (90224451)
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| Co-Investigator(Kenkyū-buntansha) |
TASHIRO Hironori Kumamoto Univ. Sch. of Med, OB/GYN, Assistant Prof., 医学部, 助手 (70304996)
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| Project Period (FY) |
2000 – 2002
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| Keywords | ovarian surface epithelium / epithelial ovarian carcinoma / PTEN / LH / hCG receptor / Cip1 / Waf1 / ICAM-1 / integrin / anchorage dependent and -independent growth |
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| Research Abstract |
Epithelial ovarian carcinomas are thought to arise from cells of ovarian surface epithelium (OSE) covering the free surface of the human ovary. Two immortalized human cell lines, OSE2a (non-tumorigenic) and OSE2b-2 (tumorigenic), were previously established from normal OSE cells of a reproductive-age patient. In the present project, we found that expression of luteinizing hormone (LH)/human chorionic gonadotropin (hCG) receptor (R) is present in OSE2a cells and absent in OSE2b-2 cells. In OSE2a cells, a low concentration (10^3 mIU/ml) of hCG enhanced anchorage-dependent growth via up-regulation of insulin-like growth factor-1 (IGF1), whereas a high concentration (10^5 mlU/ml) of hCG induced anchorage-independent growth and down-regulation of IGF1 expression. To investigate involvement of other genes in LH/hCGR-related tumorigenicity, we compared cDNA expression arrays between OSE2a and OSE2b-2 cells, and found that the following genes had lower expression in OSE2b-2 than in OSE2a: integrin β1, intercellular adhesion molecule-1 (ICAM1), and Wafl/Cipl. Subsequent semiquantitative reverse transcription porymerase chain reaction using OSE2a cells showed that expression of integrin β1 was down-regulated by a high concentration (10^5 mlU/ml) of hCG. These results suggest that LH/CGR affects anchorage-dependent and -independent growth by mediating up- and down-regulation of IGF1 and integrin β1. Repetitive and excessive activation of LH/hCGR may cause genetic alteration of its signal transduction pathway, resulting in stimulation of growth of OSE cells, initiation of ovarian carcinogenesis, and cancer progression. We have submitted a manuscript for this study to 'Cancer Science'.
Regarding the PTEN gene, the functional analysis of LH/hCGR preceded the study for characterization of immortalized OSE cells trasfected by PTEN expression vectors. We still farther study the project for the PTEN expression.
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