BACKGROUNDKu70, Ku80 and DNA-PKcs proteins take part in the repairment of DNA double-strand breaks as regulatory subunits of DNA-dependent protein kinase. The aim of this study is to investigate the expression and clinical significance of Ku70, Ku80 and DNA-PKcs proteins in patients with stage I-II non-small cell lung cancer (NSCLC).

METHODSA total of 86 patients with stage I-II NSCLC who received adjuvant chemotherapy after radical surgery were retrospectively analyzed. The expression of Ku70, Ku80 and DNA-PKcs proteins was detected by tissue microarray technique and immunohistochemical two-step method.

RESULTSThe positive rate of Ku70, Ku80 and DNA-PKcs in lung cancer tissues was 68.6%, 72.1% and 87.2%, respectively. Their expression was not related to histological classification (P > 0.05). The patients with worse prognosis seemed to have higher expression of Ku70, Ku80 and DNA-PKcs proteins, however there was no statistical significance (P > 0.05).

CONCLUSIONSKu70, Ku80 and DNA-PKcs are overexpressed in stage I-II lung cancer without prior chemotherapy. They may be not good for guidance of postoperative chemotherapy in completely resected stageI-II NSCLC.