Expression Of YAP/p-YAP In Laryngeal Squamous Cell Carcinoma And Its Clinical Significance

Objective:To investigate the expression of Yes-associated protein（YAP）and its phosphorylated protein（Phospho-Yes-associated protein,p-YAP）in laryngeal squamous cell carcinoma（LSCC）and the adjacent normal mucosa tissue,and to analyze the relationship between these and the patients’clinicopathological characteristics.To detect the relationship between the expression of YAP and the prognosis of patients with laryngeal squamous cell carcinoma.Methods:The expression of YAP at the mRNA level in 30 cases of fresh LSCC and the adjacent normal mucosa tissue was detected by the quantitative Real-time PCR.The GAPDH was used as the internal reference gene,and the target gene was analyzed by 2^-△△CT.The expression of YAP/p-YAP protein in 30 cases of fresh LSCC and the adjacent normal mucosa tissue,and their expression in nuclear/plasma protein respectively were detected by Western Blot.The expression of YAP/p-YAP protein in 136 cases of LSCC and 30 cases of the adjacent normal mucosa tissue paraffin sections were detected by the immunohistochemical SP method,and combined with the clinical data of these patients,analyzed the relationship between the differential expression and the various clinicopathological indications of these patients.Following up the prognosis of 136 patients with LSCC,analyzed the correlation between YAP expression and prognosis and investigate the risk factors.Results:1.The results of the quantitative Real-time PCR showed that the expression of YAP in LSCC tissue was 4.915±4.107,which was significantly higher than that in adjacent normal mucosa tissue,1.748±1.615,at the level of mRNA,and the difference was statistically significant（t=4.931,P<0.05）.2.The results of Western Blot showed that the relative expression of YAP protein in total proteins and nucleoproteins of the LSCC tissue were 1.448±0.538 and 1.248±0.208,which were significantly higher than that in adjacent normal mucosa tissue,0.166±0.121 and 0.054±0.022,respectively,and the differences were statistically significant（P<0.05）.However,the expression of p-YAP protein was directly opposite,which was higher in normal mucosa tissue,the difference was statistically significant（P<0.05）.Among the plasma proteins,the expression of p-YAP protein in the adjacent normal mucosa tissue was higher than that in the LSCC tissue,the difference were statistically significant（P<0.05）;but there was no significant difference in the relative expression of YAP protein（P>0.05）.3.The results of Immunohistochemical showed that YAP protein was expressed in the both nucleus and cytoplasm of laryngeal tumor cells,while p-YAP protein was mainly expressed in the cytoplasm of normal laryngeal mucosa cells,with a small amount in the nucleus.The positive expression rate of YAP protein in LSCC tissue（76.47%）was much higher than that in adjacent normal mucosa tissue（20.0%）,and the difference was statistically significant（X²=35.062,P<0.05）.The difference in the expression of YAP protein in LSCC tissue was related to clinical stage and lymph node metastasis（P<0.05）,however,it was independent of the patients’age,gender,smoking,drinking,location and degree of differentiation（P>0.05）;and the expression of p-YAP protein has correlation with patients’clinical stage（P<0.05）,but was not related to the patients’age,gender,smoking,drinking,location,degree of differentiation and lymph node metastasis（P>0.05）.4.The results of Kaplan-Meier survival analysis showed that the positive expression of YAP protein was associated with the survival rate of patients.The 3-year cumulative survival rate of patients in the positive expression group（77.2%）was lower than that in the non-expression group（95.7%）,and the difference was statistically significant（X²=8.077,P<0.05）.Multivariate Cox regression analysis showed that YAP protein expression and lymph node metastasis were independent risk factors which affect the prognosis of laryngeal tumor.Conclusion:YAP is highly expressed in the LSCC,and its expression is related to clinical stage and lymph node metastasis of patients,and it is highly expressed in both total and nuclear proteins,indicating that it is closely related to the occurrence and development of LSCC.Meanwhile,YAP and lymph node metastasis are independent risk factor affecting the prognosis of LSCC.If the expression of YAP is positive and/or lymph node metastasis,the prognosis of the patient is worse.However,p-YAP is mostly expressed in the normal mucosa tissue,and its expression is correction with patients’clinical stage.This study could provide a basis for predicting new targets for the diagnosis and treatment of LSCC.