Survivin: a promising biomarker for detection and prognosis of bladder cancer.

Survivin is a 16.5 kDa member of the inhibitor of apoptosis protein family that is overexpressed in many malignancies but rarely detected in normal differentiated adult tissues. Functionally, Survivin inhibits apoptosis, promotes cell proliferation, and induces/enhances angiogenesis. In transitional cell carcinoma of the urinary bladder, Survivin has been shown to be a promising biomarker for cancer diagnosis, prognosis and prediction of response to intravesical or systemic therapies. Moreover, in pre-clinical bladder tumor models, inhibition of Survivin expression and/or function has been shown to impede tumor cell proliferation, and markedly induce spontaneous or chemotherapy induced apoptosis. These preliminary findings should now be confirmed in large prospective trials. Furthermore, simplified, quantitative and reproducible assays need to be developed and validated for the detection of Survivin and its different isoforms.