ABSTRACT
Tumor cell resistance to cytotoxic drug is thought to be a major cause of failure in the chemotherapeutic treatment of malgnant tumors. Multidrug resistance (MDR) is associated with r expression of the MDRl gene encoding P-glycoproteintP-gp). an active efflux pump for various limphophilic compounds. P-gp was generally expressed in normal tissue and tumor. In our present investigation. we examined the expression of P-gp in human transitional cell carcinoma and normal tissue. 1. From April to June. 1992. 13 patients with transitional cell carcinoma(11 cases in bladder. cases in renal pelvis) and 5 specimens of normal urinary bladder tissue were used. 2. We stained these frozen tissue with JSB-1 (MONOSAN(R)) by immunehistochemistry. 3. The tissue sample was classified as weakly positive. moderately positive and strong positive respectively to the immunohistochemical staining under the light microgcopical observation. The weakly positive means that if the sample cell was stained with less than the fine reddish brown colored particles. The strong positive presents the cell nuclei was not seen by light microscopic examination because the cell was heavily stained with large reddish brown colored granules. In between weakly and strong positive was named as moderate positive. 4. 7 out of 13 transitional cell carcinoma showed Ash grade II,4 of this 7 belongs to moderately positive and the rest 3 of this 7 were strong positive class. All 6 cases of stage B, C, D transitional cell carcinoma belongs to moderate positive class. On the basis of the results, this study suggested that the normal bladder tissues and transitional cell carcinoma contain certain amount of P-gp. The author could conclude that there is no closerelation between the tissue staining classification.