The Correlation Study Of The Expression Of DNA-PK To The Effect Of Chemoradiotherapy And Prognosis In Esophageal Squamous Cell Carcinoma

ObjectiveTo investigate the protein expression of DNA-dependent protein kinase catalytic subunit(DNA-PKcs), Ku70and Ku80in patients with esophageal squamous cell carcinoma(ESCC), and analyze its correlation to the clinicopathologic features, the effect of chemoradiotherapy and prognosis of ESCC.MethodsEighty-seven cases with ESCC in the initial treatment from January1,2005, to December31,2010at the First Affiliated Hospital of Zhengzhou University, Department of Radiation Oncology were included in the retrospective research. We collected gender, age, smoking history, drinking history, lesion length, clinical stage, degree of differentiation of patients, and observed the prognosis of patients. Immunohistochemical method was used to detect the protein expression of DNA-PKcs, Ku70, Ku80in esophageal cancer biopsy tissue. The software of SPSS17.0was used to analyze the relationship between the expression of DNA-PKcs, Ku70, Ku80protein and the general clinical data of patients after treatment and follow-up data. The χ2test was used to evaluate the difference between the expression of DNA-PKcs, Ku70and Ku80protein in ESCC patients before chemoradiotherapy and clinical pathological features. Correlations between protein expression were assessed using the nonparametric Spearman correlation test. Survival analysis was done using the Kaplan-Meier method, and the curves were compared using the log-rank test. Cox proportional hazards regression analyses was used to multivariable prognostic analysis. P values <0.05were considered significant.ResultsDNA-PKcs, Ku70and Ku80protein were expressed in the nucleus of the tumor cell, and the positive expression rates were51.7%(45/87),58.6%(51/87),50.6%(44/87). The positive co-expression rate of three proteins is35.63%(31/87). The expression levels of DNA-PKcs,Ku70and Ku80protein in patients with ESCC were not correlated with gender, age, smoking history, drinking history, lesion length, clinical stage, degree of differentiation and tumor location(P>0.05), so was the positive co-expression of three proteins(P>0.05). Spearman correlation analysis suggested that DNA-PKcs, Ku70and Ku80was positively related(P<0.01). The CR rate of DNA-PKcs, Ku70, Ku80protein expression group and the three co-expression group was42.2%(19/45),41.2%(21/51),43.2%(19/44) and35.5%(11/31), lower than the negative expression group and three non-co-expression group (P<0.05). In univariate prognostic analysis, the overall survival rate(OS) of cases with high expression of DNA-PKcs, Ku70and Ku80is lower the those with any low expression (P<0.05). Overall survival of three proteins co-expression group is lower than the non-co-expression group (P<0.05). In multivariate analysis, the co-expression of DNA-PKcs, Ku70and Ku80and clinical stage could be seen as an independent prognostic factor of ESCC patients (P<0.05).ConclusionsThe expression of DNA-PKcs, Ku70and Ku80in ESCC endoscopic samples is not correlated with gender, age, smoking history, drinking history, lesion length, clinical stage, degree of differentiation and tumor location. The positive expression of DNA-PKcs, Ku70and Ku80in ESCC patients have poorer short-term effect of chemoradiotherapy. There was significant correlation between the expression of Ku70, Ku80,and DNA-PKcs. The expression of DNA-PKcs, Ku70, Ku80, the co-expression of DNA-PKcs, Ku70and Ku80and the clinical stage is significantly correlated with patient over survival. The co-expression of DNA-PKcs, Ku70and Ku80can be seen as an independent prognostic factor of ESCC patients.