Lung cancer (LC) and chronic ob
structive pulmonary di
sea
se (COPD) commonly coexi
st in
smoker
s, and the pre
sence of COPD increa
se
s the ri
sk of developing LC. The aim of thi
s study wa
s to identify di
stinct proteomic profile
s able to di
scriminate the
se two pathological entitie
s. Protein content wa
s a
sse
ssed in the bronchoalveolar lavage (BAL) of 60 patient
s cla
ssified in four group
s: COPD, COPD and LC, LC without COPD, and control with neither COPD nor LC. Protein
s were
separated into
spot
s by bidimen
sional polyacrylamide gel electrophore
si
s (2D-PAGE) and examined by matrix-a
ssi
sted la
ser de
sorption/ionization time of flight ma
ss spectrometry (MALDI-TOF/TOF). A total of 40 protein
s were differentially expre
ssed in the LC and/or COPD group
s a
s compared with the control group. Di
stinct protein profile
s were identified and validated for each pathological entity (LC and COPD). The main network
s involved were related to inflammatory
signalling, free radical
scavenging and oxidative
stre
ss re
spon
se, and glycoly
si
s and gluconeogene
si
s pathway
s. The mo
st relevant
signalling link between LC and COPD wa
s through the NF-¦ÊB pathway.
In conclusion, the protein profiles identified contribute to elucidate the underlying pathogenic pathways of both diseases, and provide new tools of potential use as biomarkers for the early diagnosis of LC.
ss=""h4"">Biological significance
Sequence coverage. The protein sequence coverage (95 % ) was estimated for specific proteins by the percentage of matching amino acids from the identified peptides having confidence greater than or equal to 95 % divided by the total number of amino acids in the sequence.
Ingenuity Pathways Analysis. Mapping of our proteins onto biological pathways and disease networks demonstrated that 22 proteins were linked to inflammatory signalling (p-value: 1.35 ? 10<sup>? 08sup>-1.42 ? 10<sup>? 02sup>), 15 proteins were associated with free radical scavenging and oxidative stress response (p-value: 4.93 ? 10<sup>? 11sup>-1.27 ? 10<sup>? 02sup>), and 9 proteins were related with glycolysis and gluconeogenesis pathways (p-value: 7.39 ? 10<sup>? 09sup>-1.58 ? 10<sup>? 02sup>).