Role of Progranulin Gene Expression as a Molecular Biomarker for Bladder Cancer

Bladder cancer is the second most common cancer of the urinary system. Early diagnosis of this tumor and estimation of risk of future progression has a significant impact on prognosis. Although there are several molecular markers for the diagnosis and prognosis for this tumor, their accuracy is not ideal. Progranulin is a growth factor that may play a critical role in bladder cancer. Previous reports have shown that progranulin is essential for cellular proliferation. In this study, we examined whether progranulin gene expression can be a novel molecular marker for bladder cancer and evaluated its potential suitability as a urinary biomarker for bladder cancer diagnosis. Expression of progranulin gene in tissue and urine sediment of normal and bladder cancer samples was performed by semi-quantitative reverse transcription-PCR. Also, progranulin level was estimated in 90 voided urine samples, including 65 bladder cancer patients and 25 healthy volunteers using the quantitative enzyme immunoassay technique. Significant over-expression of progranulin was observed in bladder cancer cases. This over-expression was correlated with the stage and grade of the cancer. The urinary progranulin level was significantly higher in bladder cancer patients compared to control subjects (means: 18.39±0.56 and 9.17±0.41 ng mL^-1, respectively; p<0.001). Furthermore, the urinary progranulin level at cut off value = 11.275 has a sensitivity = 93.8% and a specificity = 84% for cancer bladder diagnosis. Urinary progranulin may be considered as a simple, non-invasive test with acceptable sensitivity and specificity for bladder cancer diagnosis and may greatly improve the current diagnosis based on cytology. However, this is a preliminary study that opens the window for further researches to fully validate its results in progranulin and cancer bladder research.