Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1989: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1988: ¥1,200,000 (Direct Cost: ¥1,200,000)
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Research Abstract |
1. Androgen receptors (AR) and estrogen receptors (ER) were assayed for esophageal carcinoma and normal esophageal mucosa that were removed surgically. Six of 40 esophageal carcinomas (contain metastasized lymph nodes) were AR positive (AR(+)), five of 40, ER(+). Nine of 31 normal esophageal mucosa were AR(+), eight of 31, ER(+). 2. The number of transplanted esophageal cancers into nude mice was 15. Three were AR(+)ER(+), one was AR(+)ER(-), six were AR(-)ER(+), five were AR(-)ER(-). 3. We have studied the AR(-)ER(+) human esophageal carcinoma line transplanted into nude mice, and the growth of the tumor was significantly better in males than it was in females. Moreover it was enhanced in oophorectomized female mice, and significantly suppressed with the physiological dose (50mug/kg) of estradiol (E_2) compared to the control. This effect was confirmed in another transplanted tumorline changed AR(-)ER(-) from AR(-)ER(+). The study seemed to indicate that the inhibitory effect of estrogen in the growth of esophageal carcinoma is mediated by ERs. 4. The growth of AR of nuclens negative (ARn(-)), cytosol negative (ARc(-)), ERn(+), ERc(-) human esophageal cell line was significantly inhibited at the dose of 10^<-12> M E_2 compared to the control. While inhibitory effect of E_2 on ARn(-), ARc(-), ERn(-), ERc(-) cell line was not confirmed. The inhibitory effect of E_2 to the DNA synthesis of ERn(+) cell line was shown. These results seem to indicate that the inhibitory effect of estrogen on the cell line is mediated by ER in vitro as in vivo.
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