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

Abstract

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.