Study of Anti-germ Cell Tumor Antibody in Testicular Tumor Cell Growth and its Evaluation for Clinical Application

从人睾丸精原细胞瘤的生殖细胞和生殖细胞肿瘤中制备石蜡包埋块，获得特异性单克隆抗体5G9作为免疫原。该抗体在胚胎和成年睾丸精子形成的阶段特异性过程中与该物质发生反应。本研究结果显示了对该抗体的反应分析及其可能的临床应用。对5g9进行生化研究，经Western blot测定，该抗体为Ig M类蛋白，分子量为29KD.2。5G9与正常组织的免疫组化研究：睾丸生殖细胞和原始生殖细胞染色阳性；而精母细胞、精母细胞、精子、间质细胞和支持细胞染色为阴性。5G9与恶性肿瘤组织的免疫组化研究：典型精原细胞瘤、精原细胞瘤、胚胎癌、绒毛膜癌均染色阳性；然而，后两者的阳性率高于前两者。泌尿系恶性肿瘤，如卵黄囊瘤、畸胎瘤、恶性淋巴瘤等，染色阴性。人睾丸生殖细胞系ITO-II染色也呈阳性。5G9在睾丸诊断中的临床应用评价无精子症和少精子症的阳性率分别为80%和79%。两例少精症患者精子染色阳性，但染色率差异无统计学意义。特发性无精子症的检出率为79%。正常睾丸中的5G9被认为对精原细胞呈阳性染色，可用于确定基底膜周围的情况，而不是检测基底膜附近是否存在精原细胞。因此，使用5G9的免疫组织化学研究可以用于评估无精子症和少精子症的剩余精子产生能力水平。

A specific monoclonal antibody, 5G9, was obtained from germ cell and germ cell tumor by making paraffin-embedded blocks of human testicular seminoma and used as the immunogen. This antibody reacts with the substance in the stage-specific process of spermatogenesis in embryos and adult testicles. The result of this study show the analysis of the reaction to the antibody and its possible clinical application.1. Biochemical studies of 5G9Measurements by Western blot revealed this antibody to be a protein of the Ig M class with a molecular weight of 29KD.2. Immunohistochemical studies of 5G9 and normal tissuesTesticular germ cell and primordial germ cell stained positive ; however, spermatocytes, spermatids, spermatozoa, leydig cell and sertoli cell stained negative.3. Immunohistochemical studies of 5G9 and malignant tumor tissuesAll specimens of typical seminoma, spermatocytic seminoma, embryonal carcinoma, and choriocarcinoma stained positive ; however, the positive rate for the latter two was higher than for the former two. Urological malignant tumors, such as yolk sac tumor, teratoma, malignant lymphoma etc., stained negative. Human testicular germ cell line ITO-II also stained positive.4. Evaluation of 5G9 for clinical application in testicular diagnosisThe positive rate for azoospermia and oligozospermia was 80% and 79%, respectively. Two cases of oligozospermia which spermatozoon stained positive, but no significant difference was detected in the rate of stain. Idiopathic azoospermia showed a 79% negative rate.5G9 in normal testicles is considered to stain spermatogonia positively, and to be useful in determining the condition around the basement membrane rather than in detecting the existence of spermatogonia adjacent to the basement membrane. It is therefore suggested that immunohistochemical studies using 5G9 could be useful in evaluating the level of the residual sperm-producing ability of both azzospermia and aoligozospermia.