Yazaki K, Armstrong E G, Koide S S
Cancer. 1987 Feb 15;59(4):795-7. doi: 10.1002/1097-0142(19870215)59:4<795::aid-cncr2820590422>3.0.co;2-n.
Human chorionic gonadotropin (hCG) of pregnancy can be separated into several variants by an isoelectric focusing (IEF) method. The hCG produced by choriocarcinoma consists of components found in pregnancy sera (pI 3.9-6.0) and, in addition, unique variants with more acidic isoelectric points ranging from 3.2 to 3.7. The sera of all five patients with advanced choriocarcinoma contained these unique acidic variants of hCG and the immunoreactive levels were significantly higher in these patients than in normal pregnant women or patients afflicted with hydatidiform mole or invasive mole. When the acidic variants of hCG were treated with neuraminidase they migrated to the alkaline region (pI 9-11) of the IEF column. In conclusion, sera of choriocarcinoma patients contain unique variants of hCG. The finding that these highly acidic components can be converted to molecules with an alkaline pI by neuraminidase digestion suggests that this high negative charge may be due to an increased sialic acid content. Patients possessing the acidic variants of hCG in their sera had poor survival rate. Determination of the variants may be useful as a prognosis marker and in evaluating the efficacy of therapy.
妊娠期间的人绒毛膜促性腺激素（hCG）可通过等电聚焦（IEF）方法分离成几种变体。绒毛膜癌产生的hCG由妊娠血清中发现的成分（pI 3.9 - 6.0）组成，此外，还有等电点更酸，范围从3.2到3.7的独特变体。所有五名晚期绒毛膜癌患者的血清中都含有这些独特的hCG酸性变体，并且这些患者的免疫反应水平明显高于正常孕妇或患有葡萄胎或侵袭性葡萄胎的患者。当hCG的酸性变体用神经氨酸酶处理时，它们迁移到IEF柱的碱性区域（pI 9 - 11）。总之，绒毛膜癌患者的血清中含有hCG的独特变体。这些高酸性成分可通过神经氨酸酶消化转化为具有碱性pI的分子，这一发现表明这种高负电荷可能是由于唾液酸含量增加所致。血清中含有hCG酸性变体的患者生存率较低。变体的测定可能作为一种预后标志物以及评估治疗效果有用。
