Over-expression of KRT17 and MDK genes at mRNA levels in urine-exfoliated cells is associated with early non-invasive diagnosis of non-muscle-invasive bladder cancer

•KRT17 and MDK are over-expressed in urine cells isolated from bladder cancer cases.•KRT17/MDK are potential urinary biomarkers for diagnosis of low-grade bladder cancer.•Specificity of KRT17/MDK expression in urine is high for bladder cancer diagnosis. Current diagnostic approaches for bladder cancer (BLCA) are often invasive or lack the required sensitivity and specificity. This underscores the need for an early non-invasive diagnostic test for BLCA. This work aimed to explore the potential of molecular markers in urine-exfoliated cells for the diagnosis of non-muscle-invasive bladder cancer (NMIBC). Urine specimens (n = 140) were collected from NMIBC patients (n = 68) and control subjects (31 healthy volunteers and 41 non-cancer patients with common urological diseases [CUD]. Total RNA was extracted from the cells isolated from urine specimens. mRNA expression of selected genes: CDC20, KRT15, FOXM1, CXCR2, UPK1B, MDK, KRT20, and KRT17 was determined using RT-qPCR. The receiver operating characteristic (ROC) curve was then plotted to obtain the area under the curve (AUC), specificity, and sensitivity of the urinary mRNA markers. The expression of CDC20, MDK, UPK1B, FOXM1, KRT17, and KRT20 was up-regulated in samples obtained from low- and high-grade pathological grades of NMIBC compared to that measured in healthy subjects. Notably, MDK and KRT17 mRNA levels in the low- and high-grade cases were substantially higher than in normal and CUD groups. The AUC of the KRT17 and MDK combination in diagnosing NMIBC was 0.92, surpassing that of single genes. The sensitivity and specificity of the KRT17 and MDK combination were 74% and 94%, respectively. In diagnosing low-grade from healthy and CUD groups, analysis of the KRT17 and MDK combination yielded AUCs of 0.94 and 0.95, respectively, with sensitivities of 85% and 97%, and specificities of 93% and 85%. The findings of this study revealed that KRT17 and MDK together are potential urine-based biomarkers for early diagnosis of NMIBC.