Objective: To investigate the clinical significance of phosphorylated caspase-8 by Src in patients with operable non-small cell lung cancer.
Methods: Src and caspase-8 expressions were tested using immunohistochemistry in non-small cell lung cancer tissues and control lung tissues. The expression of phosphorylated caspase-8 at 380 tyrosine by Src was detected using Western blotting. The disease-free survival (DFS) of patients positive and negative for phosphorylated caspase-8 was analyzed with Kaplan-Meire survival curve.
Results: No significant difference was found in the positivity rate of caspase-8 or Src between the cancer tissues and control lung tissues (76.3% vs 83.3%, P>0.05; 70.1% vs 66.4%, P>0.05). All the patients with Casp8- and Src-positive cancers were positive for phosphoryalted caspase-8, whose expression rate was significantly higher in the cancer tissues than in the paired control lung tissues (52.4% vs 7.1%, P<0.05). The 2-year DFS was significantly higher in patients negative for phosphorylated caspase-8 than in the positive patients (32.0% vs 60.3%, P<0.05).
Conclusion: Phosphorylated caspase-8 may serve as a predictor for a poorer DFS in patients with operable non-small cell lung cancer.