Tumour necrosis factor-alpha: prognostic role and relationship with interleukin-8 and endothelin-1 in non-small cell lung cancer.

Cytokines mediate numerous physiological and immune reactions, which are manifested in various biological effects, including tumouricidal activity. We evaluated the expression of the pleiotropic cytokine, tumour necrosis factor-alpha (TNF-alpha), by competitive PCR technique in 47 non-small cell lung cancer (NSCLC) cases and the impact of TNF-alpha on their clinical behaviour. Using univariate analysis, our study demonstrated a positive correlation between high TNF-alpha expression and favourable prognosis in NSCLC in terms of overall survival and disease free interval (p=0.03 and 0.04, respectively) and TNF-alpha maintained its independent role in multivariate analysis. TNF-alpha can stimulate the expression of many molecules, including interleukin-8 (IL-8) and endothelin-1 (ET-1); in our study, the expression of TNF-alpha was significantly associated with high IL-8 mRNA levels (p=0.008) and ET-1 mRNA positivity (p=0.03). We suggested that TNF-alpha can induce ET-1 mRNA expression in NSCLC, similarly to IL-8 expression. Our study may also contribute to advancing the knowledge of the molecular relationship between cytokines and endothelial functions in NSCLC.