Expression of CacyBP/SIP, ERK1/2, and p38 in Low- and High-Grade Papillary Urothelial Carcinoma

Background: Papillary urothelial carcinoma (transitional cell carcinoma) is one of the most common malignant tumors of the urinary tract. Urothelial carcinomas are classified into muscle-invasive and non-muscle-invasive types. Among the latter, papillary urothelial carcinoma is further categorized into low-grade and high-grade forms. The aggressiveness of bladder cancer depends on the stage and grade of the disease. CacyBP/SIP protein and MAP kinases play key roles in various cellular processes and signaling pathways that determine cell survival or death. This study aimed to assess the expression of CacyBP/SIP, ERK1/2, and p38 in low- and high-grade papillary urothelial carcinoma using immunohistochemical and molecular analysis. Materials and Methods: Tissue samples were obtained from 20 patients with high-grade urothelial carcinoma and 20 patients with low-grade urothelial carcinoma. Adjacent non-cancerous tissues served as comparative controls. Immunohistochemistry and qRT-PCR were used to evaluate the expression of CacyBP/SIP, ERK1/2, and p38. Results: The strongest expression of the CACYBP/SIP gene was observed in tumor tissues with high malignant potential, predominantly in the nuclear compartment. Similarly, p38 kinase expression was elevated, whereas ERK1/2 expression was reduced in bladder tumor tissues compared to adjacent normal bladder tissues. Conclusions: These findings suggest that CacyBP/SIP may play a critical role in urothelial carcinoma progression by modulating ERK1/2 and p38 kinase activity.