Grant-in-Aid for Scientific Research (C)
|Allocation Type||Single-year Grants |
Obstetrics and gynecology
|Research Institution||Yamagata University (2000-2001)|
Osaka University (1999)
KURACHI Hirohisa(2000-2001) Yamagata University, School of Medicine, Professor, 医学部, 教授 (40153366)
西尾 幸浩(1999) 大阪大学, 医学系研究科, 助手 (30303952)
YAMAMOTO Toshiya Osaka University, School of Medicine, Assistant, 医学部, 助手 (80283787)
MORISHIGE Kenichirou Osaka University, School of Medicine, Assistant, 医学部, 助手 (90283788)
SAKATA Masahiro Osaka University, School of Medicine, Assistant, 医学部, 助手 (10260639)
NAKAHARA Kenji Yamagata University, School of Medicine, Assistant Professor, 医学部, 講師 (80250934)
TEZUKA Naohiro Yamagata University, School of Medicine, Assistant Professor, 医学部, 講師 (60261690)
齋藤 英和 山形大学, 医学部, 助教授 (90125766)
倉智 博久 大阪大学, 医学系研究科, 助教授 (40153366)
|Project Period (FY)
1999 – 2001
Completed(Fiscal Year 2001)
|Budget Amount *help
¥3,700,000 (Direct Cost : ¥3,700,000)
Fiscal Year 2001 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 2000 : ¥2,500,000 (Direct Cost : ¥2,500,000)
Fiscal Year 1999 : ¥700,000 (Direct Cost : ¥700,000)
|Keywords||trophoblast / adhesion molecule / invasion / chemokinesis / integrin / epidermal growth factor (EGF) / gene transcription / 絨毛細胞 / 細胞接着因子 / 上皮成長因子 (EGF) / 細胞浸潤能 / ケモタキシス / 細胞浸潤 / MAPキナーゼ / 転写因子|
The trophoblast, an important component of the mammalian placenta, has several essential biological roles in the maintenance of pregnancy. First, trophoblasts must attach to the uterine endometrium, and then they must invade to a depth at which the vascular network exists. Here, we investigated the effects of epidermal growth factor (EGF) on a2 integrin expression, adhesiveness to collagen, and invasive activity using human BeWo choriocarcinoma cells. EGF induced the expression of a2 integrin mRNA and protein, as shown by Northern blotting, Western blotting, and flow cytometry. Human chorionic gonadotropin (hCG) secretion was enhanced by the addition of EGF, which suggests that the BeWo cells functionally differentiated similarly to normal trophoblasts. EGF also dose-dependently stimulated the invasiveness of BeWo cells. Antibody against a2 integrin inhibited this effect, suggesting that it may be mediated by an increase of cell surface integrin. EGF had no effect on the adhesiveness o
f BeWo cells to collagen, whereas it stimulated the chemokinetic activity in a dose-dependent manner. The increase of chemokinetic activity was suppressed by antibody against a2 integrin. These results suggest that EGF may induce a2 integrin expression in trophoblasts, thereby enhancing their invasiveness into the endometrium via an increase of their chemokinetic activity.
Transcriptional regulation of a5 integrin, one of the adhesion molecules that are induced in accordance with invasive activity of trophoblast, was also investigated. The following results were obtained.
1) Flow cytometry analysis indicated that a5 integrin on BeWo cells were induced by the addition of EGF at 48 hours.
2) The 5'-flanking region of the human a5 integrin gene was linked to the luciferase gene to monitor how this gene was regulated by the addition of EGF. EGF increased the transcriptional activity of a5 integrin promoter as high as 5 times compared to the basal level.
3) The induction mentioned above was not suppressed by the addition of a MEK inhibitor (PD98059), suggesting that the action of EGF seemed to utilize a signaling pathway other than authentic MAP kinase cascade. Less