<正>Objective:To explore the expression of DNA polymerase iota in transitional cell carcinoma cells and tissues;Methods:RT-PCR was applied to detect the expression of polymerase iota in BIU87 and T24 cells

then the expression of polymerase iota was also detected in the same way in transitional cell car- cinoma which was derived from clinical bladder carcinoma and renal pelvic carcinoma.Results:The expres- sion of Poli was low in bladder normal membrana mucosa but significantly elevated in transitional cell car- cinoma cells.Compared with the expression of polymerase iota in bladder normal mucous membranes

the expression of polymerase iota was significantly increased in transitional cell carcinoma tissue（P<0.01） and associated with the grade of transitional cell carcinoma.Conclusion:The significantly increased ex- pression of polymerase iota may be associated with the generation and development of transitional cell car- cinoma

even with its high heterogenicity.