IMMUNOHISTOCHEMICAL ANALYSIS OF NM23 PROTEIN IN TRANSITIONAL-CELL CARCINOMA OF THE BLADDER

Objectives To elucidate the clinical significance of the nm23 gene pro duct in transitional cell carcinoma (TCC) of the bladder. Patients and methods The immunoreactivity of nm23 protein and proliferating cell n uclear antigen (PCNA) were evaluated in paraffin-embedded tumour sampl es obtained from 74 patients with TCC of the bladder who underwent tot al cystectomy between 1981 and 1993 and compared with the histological findings and clinical outcome. Results The immunoreactivity of nm23 p rotein was positive near basement membrane in normal transitional epit helium and superficial TCCs; it could also be positive at the invasive front of TCCs. The immunoreactivity of nm23 protein in TCCs was signi ficantly higher than that in normal transitional epithelium and correl ated significantly with the expression of PCNA and with histological g rade. Similarly. immunoreactivity was significantly higher in invasive TCCs than in superficial TCCs: however, there was no significant diff erence between superficial TCCs and normal transitional epithelium. Im munoreactivity of nm23 protein was not associated with the early devel opment of metastasis after radical surgery or with a favorable clinica l outcome. Conclusion immunoreactivity of nm23 protein appeared to be associated with the proliferation and progression of TCC of the bladde r. The potential role of nm23 as a suppressor of the metastatic activi ty of tumours was less prominent, partly because of mutations of nm23 in TCCs of the bladder.