YAP1 expression in nasal polyps and its relationship with epithelial mesenchymal transition

This study explored and analyzed the expression of YAP1 in nasal polyps and its correlation with the epithelial-mesenchymal transition (EMT).

58 patients with chronic sinusitis and nasal polyps, who were hospitalized in the otorhinolaryngology department of our hospital from January 2019 to May 2020 were recruited as the study cohort and placed in a nasal-polyp group, and, at the same time, another 30 nasal septum deviation with inferior turbinate hypertrophy patients were placed in a control group. The expressions of the YAP1 gene in the nasal polyp and turbinate mucosa tissues (using the immunohistochemical method), the YAP1 mRNA, E-cadherin mRNA, and vimentin mRNA expressions (using the RT-PCR method), and the YAP1, E-cadherin, and vimentin protein expressions (using Western blot) were measured, and the correlations between YAP1 and the expressions of E-cadherin and vimentin were analyzed.

The immunohistochemistry results revealed that the positive rate of YAP1 expression in the nasal-polyps group was critically higher than the YAP1 expression in the control group (P<0.05). According to the RT-PCR results, the YAP1 mRNA and vimentin mRNA relative expression levels in the nasal-polyps group were significantly higher than they were in the control group (P<0.05), but the E-cadherin mRNA relative expression level in the nasal-polyp group was notably lower than it was in the control group (P<0.05). Our Western blot analysis showed that the protein expressions of YAP1 and vimentin protein in the nasal-polyps group were significantly higher than the corresponding protein expressions in the control group (P<0.05), but the E-cadherin expression in the nasal-polyp group was especially lower than it was in the control group (P<0.05). In addition, in the nasal polyp tissues, the relative expression between the YAP1 mRNA and the E-cadherin mRNA reflected a notably negative correlation (P<0.05), but the YAP1 mRNA and vimentin mRNA showed a positive correlation (P<0.05).

High expressions of YAP1 and EMT occur in nasal polyp tissues, and YAP1 is likely to be involved in the regulation of EMT and might be one of the mechanisms in nasal polyps.