|Budget Amount *help
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1986: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1985: ¥1,600,000 (Direct Cost: ¥1,600,000)
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.