Abstract
Dopamine (DA) is a monoamine neurohormone with pleiotropic effects that exerts an immunomodulatory action inhibiting proliferation and cytotoxicity of CD4+ and CD8+ T cell. In human malignancies increased plasmatic DA levels are documented. In addiction recent reports also indicate an active production of DA by some human tumor cell lines. Small cell lung cancer (SCLC) is a very aggressive neuroendocrine human tumor able to produce several molecules with neurohormonal effect. Actually no data are available about DA plasmatic levels in patient affected by SCLC.
Aim of this study is to assess plasmatic DA levels in SCLC patients in comparison with non-small cell lung cancer (NSCLC) and healthy subjects and to correlate this data with the plasmatic levels of neuron specific enolasis (NSE).
Before treatment whole blood was collected from patients affected by lung cancer (n=50; SCLC n=15; NSCLC n=35), healthy subjects (n=10), and plasma was separated to assess its DA content by Hight Performance Liquid Chromatography (HPLC).
DA levels are significantly increased in patients affected by SCLC comparing with NSCLC [102,5 pg/ml ±18,3(SEM) vs 52,3 pg/ml ±5,8(SEM); p< 0,05] and with healthy subjects [102,5 pg/ml ±18,3(SEM) vs 38,9 pg/ml ±13,5 (SEM); p< 0,05]. In SCLC patients these increased levels are inversely correlated with the NSE plasmatic values (r= - 0,5; p < 0,05).
The data here presented show increased plasmatic DA levels in SCLC patients comparing with NSCLC and healthy subjects. Further studies are needed to assess if this increased plasmatic levels represent an active ectopical secrection of DA by SCLC and if this may exerts a possible role in the tumor growth.
- © 2012 ERS