Clinical Significance Of Telomere Protective Protein And Telomere Length In Hepatocellular Carcinoma

Background: Hepatocellular carcinoma(HCC)is a common malignant tumor and the morbidity and mortality were ranked sixth and second throughout the world.In China,the morbidity and mortality of hepatocellular carcinoma is stay in a high position.The main clinical features are insidious onset,easy recurrence and metastasis,and he five-year survival rate was only20% after surgical operation.Therefore,to explore the pathogenesis of hepatocellular carcinoma and searching for the biomarker of early detection,diagnosis and treatment has become one of the main directions in clinical and fundamental research.Previous findings have found that telomere Shelterin proteins abnormally expressed in quite a few malignancies which related to the telomere length and the activity of telomerase.As important components of Shelterin,TPP1,TRF2 and RAP1 have been studies in various tumors including glioma,oral squamous cell carcinoma,corectal cancer and non-small cell lung cancer etc,but poorly understood in hepatocellular carcinoma.Besides,telomere length plays a crucial role in the development of many kinds of tumors.Therefore,the present study was initiated to investigate the telomere length and the expression of RAP1,TRF2,TPP1 in hepatocellular carcinoma(HCC)and their relationships with clinicopathological features,further evaluated the prognostic value of them in HCC.1.To clarify the protein expression of RAP1,TPP1,TRF2 and telomere length in hepatocellular carcinoma tissue and to analyze the correlation between telomere protective protein TPP1,TRF2,RAP1 and telomere length respectively;2.To explore the the relationship between the RAP1,TPP1,TRF2,telomere length and the clinico-pathological characteristics of patients with hepatocellular carcinoma;3.To investigate the role of TPP1,TRF2,RAP1 and telomere length in the prognosis of patients with hepatocellular carcinoma.Methods:1.Pairs of primary hepatocellular carcinoma,adjacent tissue and distal tissue specimens(n=51)were obtained from the Hepatobiliary Surgery Department of Affiliated Hospital of North Sichuan Medical College from october 2014 to october 2017,the protein expression of RAP1,TPP1,TRF2 was detected by Western Blot.And detection of relative telomere length using real-time quantitative PCR.2.The correlation between telomere protective protein TPP1,TRF2,RAP1 and telomere length was analyzed.3.Addressed the clinical significance of RAP1,TPP1,TRF2 and telomere length in HCC by evaluating the correlations of RAP1,TPP1,TRF2,telomere length and clinico-pathological features.4.Collecting postoperative follow-up data,using Kaplan-Meier method to analyze survival and using Log-rank method to test the relationship between four factors of TPP1,TRF2,RAP1 and telomere length and prognosis of patients with HCC.5.The prognostic factors of patients with HCC were investigated by Objective:single factor survival analysis.The Multivariate COX regression model was used to explore the independent prognostic factors of HCC.Results:1.The protein expression of TPP1 and RAP1 showed upregulated in hepatocellular carcinoma tumor tissue specimens compared with the adjacent tissue,distal tissues in 51 pairs of primary HCC tissue specimens.The protein levels of TPP1 and RAP1 in cancer tissues were higher than those in adjacent and distal tissues(P<0.05).However,the TRF2 protein expression level had no difference between the cancer tissue,adjacent and the distal(P>0.05).2.The telomere length in the hepatocellular carcinoma tumor tissue was significantly shorter than that in the adjacent and distal tissues(P<0.05).There was no significant difference between the adjacent tissue and the distal tissue(P>0.05).3.Compared with clinico-pathological data,TPP1 was negatively correlated with age and Positively correlated with TNM stage.TRF2 was Positively correlated with TNM stage.Telomere length was negatively correlated with age.RAP1 was positively correlated with cirrhosis history.4.By analyzing the correlation between telomere Protective Protein and telomere length,TRF2 is negatively correlated with telomere length.TPP1 and RAP1 have no correlation with telomere length.5.Kaplan-Meier survival analysis showed that the total survival time and tumor free survival time of HCC Patients with high expression of TPP1 were significantly shorter than those of Patients with low TPP1 expression(P<0.05).The overall survival time and tumor free survival time of patients with high TRF2 expression were significantly shorter than those of patients with low expression of TRF2(P<0.05).However,RAP1 and telomere length have no significant correlation with the prognosis of patients with HCC.6.Single factor survival analysis showed that the protein level of TPP1 and TRF2,age and TNM stage directly affect the prognosis of patients,and negatively correlated with the tumor free survival time and the total survival time of patients with hepatocellular carcinoma.7.Multivariate Cox regression analysis showed that the protein levels of TPP1 and TRF2 were independent prognostic factors affecting the tumor free survival time of patients with HCC.Meanwhile,the level of TRF2 protein was also an independent prognostic factor affecting the overall survival time of patients with HCC.Conclusion:1.The over-expression of RAP1,TPP1 and telomere shorting may contribute to carcinogenesis of hepatocellular carcinoma.These findings provide new insight into the mechanism of carcinogenesis in hepatocellular carcinoma.2.The remarkable difference in survival periods of patients with different TPP1 and TRF2 expressions suggest that TPP1 and TRF2 may be candidate factors to estimate survival for hepatocellular carcinoma.