Unveiling the Importance of the Expression of LY6/UPAR Gene Family Members in Urothelial Carcinoma of the Urinary Bladder

Background/Objectives: Urothelial carcinomas are the most common tumors of the bladder. There are limited known cancer stem cell markers in these tumors. Ly6/uPAR gene family members are considered to be markers of cancer stem cells and tissue stem cells in mice, but studies on their expression or role in human cancers are limited. In this study, we aimed to investigate the expression of LY6/uPAR gene family members in human urothelial cancers. Methods: A total of 84 patients were included in the study. Patients diagnosed with urothelial carcinoma were divided into low-grade noninvasive and high-grade invasive carcinoma groups. Normal urothelial samples were used as a control group. RNA isolation was performed from paraffin blocks, and then cDNA was obtained. LY6D, LY6E, LY6H, LY6K, PSCA, LYPD2, SLURP1, GML, GPIHBP1, and LYNX1 genes were analyzed by qRT-PCR method. Results: We observed significantly higher expression of LY6E, LY6K, PSCA, GPIHBP1, and LYNX1 genes in urothelial carcinomas, but lower expression of LY6H, LYPD2, and SLURP1 genes in urothelial cancers compared to the control tissue. Decreased expression of LY6H, PSCA, LYPD2, SLURP1, and GPIHBP1 genes was significantly correlated with poor survival. Conclusions: In the present study, the expression of this gene family in bladder cancer was investigated for the first time in the literature. Given their potential prognostic role and possible relevance as therapeutic targets, this study presents preliminary observations that add to the existing literature.