DNA methylation is the most common and well-characterized epigenetic change in human cancer. Recently, the association between GATA-binding protein 5 (GATA5) methylation and carcinogenesis of various types of tumors was investigated. The aim of the present study was to evaluate the effect of GATA5 methylation status on clinicopathological features and prognosis in primary non-muscle invasive bladder cancer (NMIBC) patients with a long-term follow-up period. The GATA5 methylation status was determined for 171 human bladder specimens (eight normal controls [NCs] and 163 primary NMIBC patients) using quantitative pyrosequencing analysis. The primary NMIBC tissues were obtained from patients who underwent transurethral resection (TUR) for histologically diagnosed transitional cell carcinomas between 1995 and 2012 at Chungbuk National University Hospital. GATA5 methylation was significantly higher in NMIBC patients than in NCs and was significantly associated with higher grade and more advanced stage of cancer. Kaplan-Meier estimates showed significant differences in tumor recurrence and progression according to GATA5 methylation status (each p<0.05). Our results show that increased methylation of GATA5 was significantly associated with not only aggressive characteristics but also poor prognosis in primary NMIBC patients. Alteration of GATA5 methylation might be used as a biomarker for prognosis of NMIBC patients. However, prospective and functional investigations are necessary to clarify the role of GATA5 methylation in future clinical management of patients with NMIBC.

The nasal cavity encounters various irritants during inha¬lation such as dust and pathogens. To detect and remove these irritants, it has been postulated that the nasal mucosa epithelium has a specialized sensing system. The oral cavity, on the other hand, is known to have bitter taste receptors (T2Rs) that can detect harmful substances to prevent ingestion. Recently, solitary chemosensory cells expressing T2R subtypes have been found in the respiratory epithelium of rodents. In addition, T2Rs have been identified in the human airway epithelia. However, it is not clear which T2Rs are expressed in the human nasal mucosa epithelium and whether they mediate the removal of foreign materials through increased cilia movement. In our current study, we show that human T2R receptors indeed function also in the nasal mucosa epithelium. Our RT-PCR data indicate that the T2R subtypes (T2R3, T2R4, T2R5, T2R10, T2R13, T2R14, T2R39, T2R43, T2R44, T2R 45, T2R46, T2R47, T2R48, T2R49, and T2R50) are expressed in human nasal mucosa. Furthermore, we have found that T2R receptor activators such as bitter chemicals augments the ciliary beating frequency. Our results thus demonstrate that T2Rs are likely to function in the cleanup of inhaled dust and pathogens by increasing ciliary movement. This would suggest that T2Rs are feasible molecular targets for the development of novel treatment strategies for nasal infection and inflammation.