Lung cancer is the leading cause of tumor-related mortality, therefore significant
effort is directed towards understanding molecular alterations occurring at the origin
of the disease to improve current treatment options. The aim of our pilot-scale study
was to carry out a detailed proteomic analysis of formalin-fixed paraffin-embedded
tissue sections from patients with small cell or non-small cell lung cancer (adenocarcinoma,
squamous cell carcinoma, and large cell carcinoma). Tissue surface digestion was performed
on relatively small cancerous and tumor-adjacent normal regions and differentially
expressed proteins were identified using label-free quantitative mass spectrometry
and subsequent statistical analysis. Principal component analysis clearly distinguished
cancerous and cancer adjacent normal samples, while the four lung cancer types investigated
had distinct molecular profiles and gene set enrichment analysis revealed specific
dysregulated biological processes as well. Furthermore, proteins with altered expression
unique to a specific lung cancer type were identified and could be the targets of
future studies.
