Objective: To study the relationship between Fas protein expression and DNA content in non-small cell lung cancer (NSCLC).
Methods: Fas protein expression and DNA content in resected samples from 33 NSCLC patients and 17 normal controls were detected by flow cytometry. Fas expression and DNA content were compared with cell proliferation activity which was defined by proliferation index and s-phase fraction (SPF), and with clinicopathological parameters.
Results: The percentage of DNA aneuploidy in NSCLC was 82%. The DNA index (DI), PI and SPF in NSCLC were 1.36 +/- 0.23, 0.29 +/- 0.09 and 0. 144 +/- 0.078 respectively, which were significantly higher than those in normal lung tissue. The Fas protein expression was lower in NSCLC than that in normal tissue (P = 0.000) and showed negative correlation with PI (P = 0.024) and SPF (P = 0.004). Fas expression and the cell proliferation activity were not correlated to the clinicopathological parameters including age, tumor size, lymph node metastasis and the histological types of lung cancer (P > 0.05).
Conclusions: Decrease of Fas protein expression and increase of proliferation activity are common in NSCLC. The reduction of Fas protein expression may affect the proliferation activity of NSCLC. This abnormal regulation of apoptosis and proliferation may play an important role in the pathogenesis of NSCLC.