The Expression Of DNA-PKcs In Nsclc And Its Clinical Significance

Background Lung cancer is one of the most common malignant tumors in the world, and radiation therapy is an important means for lung cancer treatment. Determinants of tumor radiosensitivity are the intrinsic sensitivity of tumor cells, which affected by the cellular DNA double-strand break (DSB) repair capacity. Homologous recombination (HR) and the unusual origin end joining (NHEJ) are two major pathways to repair DSB. DNA-dependent protein kinase (DNA-PK), consisting of a catalytic subunit (DNA-PKcs) and the Ku70 and Ku86 proteins, is an essential protein of NHEJ and participates in the repair of DSB. DNA-PKcs plays an important role in the incidence and prognosis of tumor.Objective To explore the connection of the expression of DNA-PKcs and the clinicopathological characteristic, radiation sensitivity and survival of NSCLC, and provide some valuable theoretical guidance for the radiation therapy of NSCLC.Methods Immunohistochemical method was used to detect the expression of DNA-PKcs in 73 NSCLC cancer tissues and para-cancerous tissues from the same patients. The correlation of DNA-PKcs expression to clinicopathological characteristic and prognosis of NSCLC were analyzed. The Chi-square test was used for statistic analysis.Result 1.Expression of DNA-PKcs in the cancer tissues and para-cancerous tissues of NSCLC: In the cancer tissues and para-cancerous tissues of 73 NSCLC, the high-expression rate was 90.4% and 9.6% respectively. The expression of DNA-PKcs in the cancer tissues was significantly higher than that in the para-cancerous tissues, and the differences had statistical significance(P<0.01).2. The relationship between the expression of DNA-PKcs and the clinicopathological characteristic of NSCLC: The expression of DNA-PKcs had no significant correlations to gender, age, TNM staging, pathological type and the degree of histological differentiation of NSCLC(P>0.05).3. The relationship between the expression of DNA-PKcs and the short time effect and the survival of NSCLC: The expression of DNA-PKcs had no significant correlations to the short time effect of the simple radiotherapy patients(P>0.05).AND the expression of DNA-PKcs was not related to 1-year and 2-year survival of NSCLC patients with postoperative radiotherapy.(P>0.05).Conclusion 1. The expression of DNA-PKcs in the cancer tissues of NSCLC was significantly higher than that in the para-cancerous tissues, suggesting that DNA-PKcs may be a biomarker for NSCLC cancer tissues different with para-cancerous tissues and normal tissues, and it could be recognized as a tumor marker of NSCLC.2. The expression of DNA-PKcs in the different genders, ages, pathological types and different stages of NSCLC was no significant difference.3. The expression of DNA-PKcs had no significant correlations to the degree of histological differentiation of NSCLC.4. The expression of DNA-PKcs had no significant correlations to the radiation sensitivity and the prognosis of NSCLC patients treated with radiotherapy.