Hoshina M, Boime I, Mochizuki M
Nihon Sanka Fujinka Gakkai Zasshi. 1984 Mar;36(3):397-404.
The human trophoblast elaborates at least two major hormones, hPL and hCG(alpha, beta). To clarify the mechanism of biosynthesis and the gene expression of hPL and hCG(alpha, beta), the specific mRNA should be examined. We here studied the cytological distribution of these mRNAs in trophoblastic tissue of normal placenta, hydatidiform mole and choriocarcinoma by in situ hybridization using complementary DNAs(cDNA) corresponding to hPL and hCG alpha, beta-subunit. mRNAs for hPL and hCG alpha, beta were primarily observed on syncytiorophoblasts excepting some cytotrophoblasts which contain the signals for hCG alpha mRNA and probably beta mRNA. Therefore, we came to the conclusion that hPL and hCG were synthesized mainly in syncytiotrophoblasts. AT the same time, we believe that the gene expression of hCG alpha and probably hCG beta begins before transformation from cyto- to syncytiotrophoblast, while that of hPL appears later in well differentiated syncytiotrophoblasts. On the other hand, in choriocarcinoma hPL mRNA was not observed while many signals for hCG alpha, beta mRNA were localized in syncytiotrophoblastic cells. In other words, the hPL gene was not expressed in choriocarcinoma because of the blocking of trophoblastic differentiation. The data presented here show that the gene expression of hPL and hCG alpha, beta is closely related to trophoblastic differentiation and/or dedifferentiation (tumoregenesis).
人滋养层细胞可分泌至少两种主要激素，即人胎盘催乳素（hPL）和人绒毛膜促性腺激素（hCG，α、β亚基）。为阐明hPL和hCG（α、β）的生物合成机制及基因表达情况，应对其特异性mRNA进行检测。我们在此通过原位杂交技术，利用与hPL及hCGα、β亚基对应的互补DNA（cDNA），研究了这些mRNA在正常胎盘、葡萄胎和绒毛膜癌滋养层组织中的细胞学分布。hPL及hCGα、β的mRNA主要在合体滋养层细胞中观察到，不过一些细胞滋养层细胞也含有hCGα mRNA的信号，可能还有β mRNA的信号。因此，我们得出结论，hPL和hCG主要在合体滋养层细胞中合成。同时，我们认为hCGα以及可能的hCGβ的基因表达在细胞滋养层细胞向合体滋养层细胞转化之前就已开始，而hPL的基因表达则在分化良好的合体滋养层细胞中出现得较晚。另一方面，在绒毛膜癌中未观察到hPL mRNA，而许多hCGα、β mRNA的信号定位于合体滋养层细胞中。换句话说，由于滋养层细胞分化受阻，hPL基因在绒毛膜癌中未表达。此处呈现的数据表明，hPL和hCGα、β的基因表达与滋养层细胞的分化和/或去分化（肿瘤发生）密切相关。
