PRODUCTION AND CHARACTERIZATION OF A MONOCLONAL-ANTIBODY (MSN-3) FOR UTERINE ENDOMETRIAL AND ENDOCERVICAL ADENOCARCINOMA

A monoclonal antibody (MSN-3) was raised using HEC-108 cells derived f rom poorly differentiated endometrial carcinoma as the immunogen. The immunoglobulin subclass of MSN-3 was IgGr1. The target antigen of MSN- 3 was a protein with a molecular weight of 77 kDa, and it was shown to be localized in the cytoplasm. MSN-3 only reacted with 14% of normal proliferative endometrium cells, but it showed a high positivity rate of 66% for endometrial carcinoma. The target antigen of MSN-3 increase d as endometrial cells became more malignant, and the possibility of c hanges in localization was also suggested. Moderately and poorly diffe rentiated endometrial carcinoma showed a high positivity rate for MSN- 3. MSN-3 reacted rarely or not at all with normal cervical glandular t issue, but the positivity rate for cervical adenocarcinoma (especially endocervical adenocarcinoma) was a high rate of 59%. The patterns of staining of endocervical adenocarcinoma by MSN-3 included diffuse stai ning of the whole cytoplasm and not only that near the glandular lumen , as well as staining of the basal cytoplasm. Changes in the localizat ion of the target antigen were clearly associated with carcinogenesis of the cervical glandular cells. The MSN-3-positive rate was high in p atients with lymph node metastasis and vascular invasion. Among the st aining patterns, the basal and diffuse patterns tended to increase wit h malignacy. The basal pattern of staining was characteristic of MSN-3 , suggesting that it might assist in the diagnosis of cervical adenoca rcinoma.