Moleculon endocrinologieal stidies on the rcqulation of synthesis and socretion of hCG( , ) by trophoblastic and non-trophoblastic cells.

本实验采用体外培养的人正常胎盘、绒毛膜癌滋养细胞及BeWo细胞，观察了在类固醇激素、EGF、PDGF、甲状腺激素及二丁酰环腺苷酸（dbcAMP）存在或不存在的情况下，正常及恶性滋养细胞hCG（，）mRNA水平及分泌的调节。通过与标记的cDNA探针原位杂交的组织切片上的平均颗粒计数来定量估计hCG（，）和hPL mRNA的细胞水平。在正常早期胎盘培养液中加入孕酮（5-20 μ g/ml），可引起细胞内hCG（，）mRNA水平下降和hCG（，）分泌减少，而孕酮对hPL mNAa水平无影响。添加17 -雌二醇（1-10 ng/ml）引起细胞hCG mRNA水平的增加以及hCG分泌的增加，而不影响hCG和hPL mRNA水平。与正常胎盘相反，绒毛膜癌对孕酮的加入没有反应。另一方面，加入EGF（100 ng/ml）、PDGF（2U/ml）、L-T_3（10 μ <-8>M）或dbcAMP（1 mM）可使正常胎盘和BeWo细胞培养物中hCG（，）水平显著升高。这表明正常和恶性滋养细胞之间hCG合成的刺激调节没有差异。然而，EGF和DbcAMP对hCG合成的刺激作用的幅度在BeWo细胞中比在正常滋养层组织中大得多。EGF受体定位于合体滋养细胞。一种肿瘤促进剂，佛波醇肉豆蔻酸酯乙酸酯（PMA），这是一种蛋白激酶C的刺激剂，协同增强cAMP诱导的BeWo细胞hCG合成和分泌的刺激。

The regulation of hCG ( , ) mRNA levels and secretion in normal and malignant trophoblasts was investigated by culturing trophoblastic tissues from normal placenta and choriocarcinoma as well as BeWo cells in the presence or absence of steroid hormone, EGF, PDGF, thyroid hormone or dibutyryl cAMP (dbcAMP). Cellular levels of hCG( , ) and hPL mRNAs were quantitatively estimated by mean grain counts on tissue sections hybridized in situ with labeled cDNA probes. Addition of progesterone (5-20 g/ml) to the culture of normal early placenta caused a decrease in the cellular levels of hCG ( , ) mRNAs and a decline in hCG ( , ) secretion, while progesterone did not affect hPL mNAa levels. Addition of 17 -estradiol (1-10 ng/ml) caused an increase in the cellular levels of hCG mRNA together with an increase in hCG secretion without affecting hCG and hPL mRNA levels. In contrast to normal placenta, choriocarcinoma did not respond to the addition of progesterone. This suggests that progesterone selectively suppresses hCG ( , ) synthesis by normal placenta and that the inhibitory regulation of hCG synthesis in choriocarcinoma is different from that in normal placenta.On the other hand, addition of EGF (100ng/ml), PDGF (2 U/ml), L-T_3(10 ^<-8>M) or dbcAMP (1mM) caused significant increases in hCG ( , ) levels in cultures of normal placenta as well as BeWo cell line. This suggests that there are no differences in the stimulatory regulation of hCG synthesis between normal and malignant trophoblasts. However, the magnitude of the stimulatory effects of EGF and DbcAMP on hCG synthesis was much greater in BeWo cells than that in normal trophoblastic tissues. EGF-receptor was localized on syncytiotrophoblast. A tumor promotor, phorbol myristate acetate (PMA), which is a stimulator of protein kinase C, synergistically enhanced cAMP-induced stimulation of hCG synthesis and secretion by BeWo cells.