Identification of tumor associated antigen in cancer patient using monoclonal antibody and evaluation of biological activity of it.

用人子宫内膜癌细胞系免疫BALB/C小鼠，制备了IgM类单克隆抗体（Mab）。这种Mab，被命名为Mab- c12，对子宫内膜癌表现出很强的反应性，但对正常子宫内膜的反应性要低得多。在各种肿瘤患者的血清中检测到单克隆抗体- c12识别的抗原（C12-Ag），而在非肿瘤患者和正常人的血清中检测不到。发现单抗- c12能凝集O型红细胞（< γ >, b, c），但不凝集A型，b型或AB型< γ >, b, c。为了评估单抗- c12对碳水化合物的特异性，使用单抗- c12、欧洲乌氏凝集素I和单克隆抗h抗体进行组织染色。在子宫内膜癌组织中，H和C12-Ag的含量均升高，但与H抗原相比，C12-Ag的升高幅度极大。O型血患者的内皮细胞中普遍未发现C12-Ag。在血清中，H抗原的水平是多种多样的，并取决于宿主的血型。由于O型血患者血清中H抗原水平高于a型或b型血患者，因此H抗原作为肿瘤相关血清标志物的价值不大，但血清中C12抗原不受ABO血型患者的影响。从这些结果可以得出结论，C12单克隆抗体是一种独特的单克隆抗体，可以与癌症患者血清中的h样抗原反应，而与ABO血型无关。单克隆抗体C12可能在癌症患者的肿瘤标志物检测中具有重要作用。

An IgM class monoclonal antibody (Mab) was produced by immunizing BALB/C mice with a human endometrial carcinoma cell line. This Mab, designated as Mab-C12, exhibited strong reactivity against endometrial carcinoma, but much less reactivity against normal endometria. The antigen recognized by Mab-C12 (C12-Ag) was detected by radiometric assay in the sera of patients with various carcinomas, but not in the sera of patients without carcinomas or of normal individuals. Mab-C12 was found to agglutinate type O red blood cells ( <gamma> , b, c), but not type A, B, or AB <gamma> , b, c. To assess the carbohydrate specificity to Mab-C12, tissue stainings were performed using Mab-C12, Ulex europaeus lectin I, and a monoclonal anti-H antibody. In tissues of endometrial carcinoma, the amount of both H and C12-Ags increased, but the increase of C12-Ag was extremely high, compared with the H antigen. The C12-Ag was not generally found in the endothelial cells of blood type O patients. In sera, the levels of H antigen were various and depended on the host's blood type. The H antigen was not valuable as a tumor-associated serum marker, because sera from blood type O individuals indicated higher levels of the H antigen than those with blood type A or B. But the C12 antigen in sera was not influenced by ABO blood group of patients. From these results, it was concluded that the Mab C12 was a unique Mab which reacted with an H-like antigen in the sera of patients with carcinomas, irrespective of ABO blood group. The Mab C12 may have an important role to detect on tumor marker of cancer patients.