The investigators' experimental study found that gossypol was the natural inhibitor of apyrimidinic endonuclease 1 (APE1) and clinical study observed that high expression of APE1 was relative to the platinum-resistance in non-small cell lung cancer. Thus the purpose of this study is to find out whether gossypol can improve the sensitivity of cisplatin-based chemotherapy in the non-small cell lung cancer with apurinic apyrimidinic endonuclease 1 (APE1) high expression