[Nuclear factor-kappaB activity and its correlation with cell proliferation in non-small cell lung cancer tissues].

OBJECTIVE: To investigate the nuclear factor (NF)-kappaB activity in human non-small cell lung cancer (NSCLC) tissues and to explore the correlation between NF-kappaB activity and cell proliferation, between NF-kappaB activity and cell spontaneous apoptosis.

METHODS: Thirty samples of non-small cell lung cancer tissues and 15 normal lung tissues were collected from May to October in 2006. NF-kappaB activation was determined by electrophoretic mobility shift assay (EMSA). CyclinD1 level was examined by RT-PCR and Western blot. Proliferation cell nuclear antigen (PCNA) protein was examined by immunohistochemical analysis. Spontaneous cell apoptosis was determined by the TUNEL method.

RESULTS: There was significant difference (F=78.96, P<0.01) in NF-kappaB activity among normal lung tissue group (24,826+/-3724), squamous-cell carcinoma tissue group (28,028+/-4204), and adenocarcinoma tissue group (35,425+/-5317). The NF-kappaB activity in the squamous-cell carcinoma group and the adenocarcinom tissue group was higher than that in the normal lung tissue group (all P<0.01); and the NF-kappaB activity is in the adenocarcinoma tissue group was higher compared with that in the squamous-cell carcinoma group (P<0.05). There was significant difference (F=62.43, P<0.01) in the cyclinD1 mRNA level among normal lung tissue group (2.04+/-0.24), the squamous-cell carcinoma group (2.91+/-0.37), and the adenocarcinoma group (4.13+/-0.36). There was significant difference (F=89.24, P<0.01) in cyclinD1 protein level among normal lung tissue group (0.31+/-0.06), the squamous-cell carcinoma group (0.43+/-0.07), and the adenocarcinoma group (0.58+/-0.08). There was significant difference (F=45.61, P<0.01) in PCNA protein level among the normal lung tissue group (0.32+/-0.09), the squamous-cell carcinoma group (0.42+/-0.10), and the adenocarcinima group (0.54+/-0.16). There was no significant difference (F=1.86, P>0.05) in apoptosis index among the normal lung tissue group (2.58%+/-0.39%), the squamous-cell carcinoma group (2.27%+/-0.34%), and the adenocarcinoma group (2.92%+/-0.59%). The NF-kappaB activity was positively correlated with cyclin D1 mRNA level, cyclin D1 protein level, and PCNA protein level in the squamous-cell carcinoma group (r=0.51, P<0.05, r=0.54, P<0.05, r=0.60, P<0.05), respectively; the NF-kappaB activity was also positively correlated with cyclinD1mRNA, cyclinD1protein level, and PCNA protein level in the adenocarcinoma group (r=0.60, P<0.05; r=0.64, P<0.05; r=0.68, P<0.05), respectively. The NF-kappaB activity in the squamous-cell group and the adenocarcinoma group was not related to cell apoptosis index.

CONCLUSION: NF-kappaB activity increased in NSCLC tissues. Abnormal NF-kappaB activation may be associated with cell proliferation, but do not affect spontaneous cell apoptosis in NSCLC tissues.