Cellular heterogeneity in normal and neoplastic human urothelium: a study using murine monoclonal antibodies.

G Dotsikas,Gb Price,Pe Kovac,Gk Ward,Pp Major,Wj Mackillop,Ss Stewart,T Konowalchuk,Mm Elhilali

doi:10.1038/bjc.1987.220

Abstract

To assist in the description of the cellular heterogeneity present in normal and neoplastic urothelium, a panel of monoclonal antibodies (MoAbs) was raised against human transitional cell carcinoma (TCC) of the urinary bladder. All immunizations were carried out using whole cells and membrane preparations from well differentiated human TCCs. Two fusions produced 145 hybridomas. Following primary screening by ELISA and secondary screening with immunohistochemistry, three useful antibodies were identified. MoAb 35.48 binds to all cell layers of the normal urothelium and well differentiated tumours, but not to the majority of poorly differentiated tumours. MoAb 21.48 binds preferentially to the basal cell layer of normal urothelium and to some well differentiated papillary TCCs, but poorly differentiated tumours exhibit diffusely positive staining. MoAb 21.48 also shows cross-reactivity with basal cell layers of other epithelia. MoAb 5.48 binds preferentially to the superficial cell layers of normal urothelium and well differentiated TCCs, but exhibits less binding in poorly differentiated tumours with loss of the preferential superficial staining. Quantitative flow cytometric studies indicate that MoAb 5.48 binds to a cell-surface antigen which is present on significantly fewer cells of poorly differentiated tumours than on either normal urothelium (P less than 0.05), or well differentiated tumours (P = 0.05).

Highlights

The procedure for the production of membrane preparations has previously been described by Bates et al (1985)
We subsequently studied the binding of the three monoclonal antibodies (MoAbs) to fixed tissue sections, in which tissue architecture is better preserved allowing for a more detailed evaluation of the staining pattern
The preferential binding of MoAb 5.48 to the superficial cell layers of normal urothelium suggests that it binds to a cell-surface antigen which is acquired or exposed during the process of urothelial cell differentiation

Summary

Methods

Human TCCs were obtained from the operating rooms of the McGill University Teaching Hospitals. Specimens were divided under the supervision of the pathologist with a portion sent for routine histology and a representative sample was made available for laboratory studies. Normal human tissues were obtained from autopsies performed within 6h of death from any non-neoplastic cause and were confirmed to be normal by light microscopy. Specimens of non-urothelial malignancies were obtained from the tumour bank at the McGill Cancer Centre. The procedure for the production of membrane preparations has previously been described by Bates et al (1985).

Results

Discussion

Conclusion