Jokhi P P, King A, Loke Y W
Department of Pathology, University of Cambridge, UK.
Cytokine. 1994 Jul;6(4):433-42. doi: 10.1016/1043-4666(94)90068-x.
Trophoblast invasion of the maternal uterus during human placentation is a highly complex process involving proliferation, migration and cell differentiation. Tyrosine kinase receptors are known to be involved in such functions. The epidermal growth factor-receptor (EGF-R) and c-erbB2 proto-oncogene products are two closely related tyrosine kinase receptors which are expressed in high amounts in human placenta. In this study, we have investigated the expression of EGF-R and c-erbB2 proteins by different trophoblast populations using immunohistochemistry. EGF-R was expressed by proliferative villous cytotrophoblasts, but not by non-proliferative, invasive, extravillous cytotrophoblasts. In contrast, c-erbB2 was expressed by invasive extravillous trophoblasts (EVT) but not by villous cytotrophoblasts. Expression of both receptors was seen only by the terminally differentiated placental bed giant cell and villous syncytiotrophoblast populations. This precise spatial expression suggests that EGF-R plays an important role in trophoblast proliferation whereas c-erbB2 may be important for trophoblast invasion and differentiation. The surface expression of these receptors on normal isolated first trimester trophoblasts and on choriocarcinoma cell lines was also investigated by flow cytometry, and compared with that of the c-erbB2-overexpressing mammary tumour cell line BT474. Isolated trophoblasts were shown not to overexpress c-erbB2, and no differences in either EGF-R or c-erbB2 expression were seen between normal and malignant trophoblasts.
在人类胎盘形成过程中，滋养层细胞侵入母体子宫是一个高度复杂的过程，涉及增殖、迁移和细胞分化。已知酪氨酸激酶受体参与此类功能。表皮生长因子受体（EGF-R）和c-erbB2原癌基因产物是两种密切相关的酪氨酸激酶受体，它们在人胎盘中大量表达。在本研究中，我们使用免疫组织化学方法研究了不同滋养层细胞群体中EGF-R和c-erbB2蛋白的表达情况。EGF-R在增殖性绒毛细胞滋养层细胞中表达，但在非增殖性、侵袭性的绒毛外细胞滋养层细胞中不表达。相反，c-erbB2在侵袭性绒毛外滋养层细胞（EVT）中表达，但在绒毛细胞滋养层细胞中不表达。仅在终末分化的胎盘床巨细胞和绒毛合体滋养层细胞群体中观察到两种受体的表达。这种精确的空间表达表明，EGF-R在滋养层细胞增殖中起重要作用，而c-erbB2可能对滋养层细胞的侵袭和分化很重要。我们还通过流式细胞术研究了这些受体在正常分离的孕早期滋养层细胞和绒毛膜癌细胞系上的表面表达，并与c-erbB2过表达的乳腺肿瘤细胞系BT474进行了比较。结果显示，分离的滋养层细胞不表达c-erbB2，正常和恶性滋养层细胞在EGF-R或c-erbB2表达上均无差异。
