Dysfunction of natural killer cells in patients with transitional cell carcinoma

Previous studies had established that transforming growth factor-β1 (TGF-β1) is highly expressed in bladder tumor, facilitating progression and spreading of the cancerous cells. Here, we report that both the number and the cytotoxic function of natural killer (NK) cells are decreased in patients with superficial transitional cell carcinoma (TCC). In consistent with previously reported findings, the plasma TGF-β1 concentration is also elevated in patients with superficial TCC. In vitro, the cytotoxic function of NK cells was impaired by the presence of TGF-β1. Hence, our data suggested elevated concentration of serum TGF-β1 in loss of NK cytotoxicity in superficial TCC patients, implicating altered innate immunity may correlate with the incidence of TCC.