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

用石蜡包埋的人睾丸精原细胞瘤石蜡切片，从生殖细胞和生殖细胞瘤中获得特异性的单抗5G9，并将其作为免疫原。这种抗体在胚胎和成人睾丸中精子发生的特定阶段过程中与该物质发生反应。本研究的结果显示了对抗体反应的分析及其可能的临床应用。对5G9的生化研究表明，该抗体是一种Ig M类蛋白，分子量为29KD2。5G9和正常组织中睾丸生殖细胞和原始生殖细胞染色呈阳性，而精母细胞、精子细胞、精子、间质细胞和支持细胞染色均为阴性。典型精原细胞瘤、精细胞性精原细胞瘤、胚胎癌和绒毛膜癌的免疫组织化学染色均为阳性，但后两者的阳性率高于前两者。泌尿系统恶性肿瘤，如卵黄囊瘤、畸胎瘤、恶性淋巴瘤等，染色均为阴性。人睾丸生殖细胞株ITO-II也呈阳性。5G9在睾丸诊断中的临床应用价值无精子症和少精子症的阳性率分别为80%和79%。少精子症2例，精子染色阳性，但染色百分率无明显差异。特发性无精子症的阴性率为79%。正常睾丸中的5G9被认为是精原细胞的阳性染色，并有助于判断基底膜周围的情况，而不是检测基底膜附近精原细胞的存在。因此，用5G9免疫组织化学方法检测无精子症和无精子症患者的残余生精能力是一种有用的方法。

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.