[Detection of squamous cell differentiation in experimental tumors of urothelium by using epidermal G2 chalone]

The presence of epidermal G2 chalone was investigated by different immunochemical methods in normal urothelium and in tumors of the urinary bladder induced in rats with N-butyl-N-butanol-(4)-nitrosamine. This chalone was not revealed in normal urothelium but found in 37 out of 56 tumors examined. In all these 37 tumors, squamous urothelial metaplasia was detected by electron or even light microscopy. The extent of morphological manifestations of squamous metaplasia showed a definite correlation with the concentration of chalone in tissue extracts. The method used may be applied as a subsidiary test for the determination of focal squamous metaplasia in biopsy material of human urothelial tumors which is of importance for prognosis of the disease.