Department of Medicine/Oncology, Stanford University, Stanford, CA 94305, USA.
Rev Endocr Metab Disord. 2011 Dec;12(4):323-32. doi: 10.1007/s11154-011-9193-1.
The primary embryonic signal in primates is chorionic gonadotropin (CG, designated hCG in humans), that is classically associated with corpus luteum rescue and progesterone production. However, research over the past decade has revealed the presence of the hCG receptor in a variety of extragonadal tissues. Additionally, discoveries of the multiple variants of hCG, namely, native hCG, hyperglycosylated hCG (hyp-hCG) and the β- subunit of the hyperglycosylated hCG (hCG-free β) has established a role for extragonadal actions of hCG. For the initiation and maintenance of pregnancy, hCG mediates multiple placental, uterine and fetal functions. Some of these include development of syncytiotrophoblast cells, mitotic growth and differentiation of the endometrium, localized suppression of the maternal immune system, modulation of uterine morphology and gene expression and coordination of intricate signal transduction between the endometrium. Recurrent pregnancy loss, pre-eclampsia and endometriosis are associated with altered responses of hCG, all of which have a detrimental effect on pregnancy. A role for hyp-hCG in mediating the development of both trophoblastic and non-trophoblastic tumors has also been suggested. Other significant non-gonadal applications of hCG include predicting preeclampsia, determining the risk of Down's syndrome and gestational trophoblastic disease, along with relaxing myometrial contractility and preventing recurrent miscarriages. Presence of hCG free-β in serum of cancer patients enables its usage as a diagnostic tumor marker. Thus, the extragonadal functions of hCG encompasses a wide spectrum of applications and is an open area for continued investigation.
在灵长类动物中，主要的胚胎信号是绒毛膜促性腺激素（CG，在人类中称为 hCG），它通常与黄体拯救和孕酮产生有关。然而，过去十年的研究揭示了 hCG 受体存在于各种性腺外组织中。此外，hCG 的多种变体，即天然 hCG、高糖基化 hCG（hyp-hCG）和高糖基化 hCG 的β亚基（hCG-free β）的发现，确立了 hCG 在外周作用的角色。对于妊娠的启动和维持，hCG 介导多种胎盘、子宫和胎儿功能。其中一些包括合胞滋养层细胞的发育、子宫内膜的有丝分裂生长和分化、局部抑制母体免疫系统、调节子宫形态和基因表达以及协调子宫内膜之间复杂的信号转导。复发性流产、先兆子痫和子宫内膜异位症与 hCG 反应改变有关，所有这些都对妊娠有不利影响。hyp-hCG 在介导滋养层和非滋养层肿瘤的发展中也具有作用。hCG 的其他重要非性腺应用包括预测先兆子痫、确定唐氏综合征和妊娠滋养细胞疾病的风险，以及放松子宫平滑肌的收缩性和预防复发性流产。癌症患者血清中 hCG-free-β 的存在使其可作为诊断肿瘤标志物。因此，hCG 的外周功能涵盖了广泛的应用领域，是一个持续研究的开放领域。
