A comparative protein analysis of lung cancer, along with three controls using a multidimensional proteomic approach

Lung cancer is an important respiratory disease accounting for millions of deaths worldwide. Developments in proteomics techniques and mass spectrometry offer comprehensive answers to unravel the complexities of lethal diseases such as lung cancer at the molecular level. The current study focuses on the proteomic profiling of lung cancer and its comparison with other controls including chronic smoker (high-risk individuals), obstructive pulmonary disease (COPD), and healthy control. A multistep proteomic strategy was used on the pooled plasma of each group including depletion of seven most abundant proteins, 2D-SDS-PAGE separation followed by matrix-assisted laser desorption/ionization time-of-flight/time-of-flight mass spectrometry (MALDI-TOF-TOF-MS) analysis. Total 23 proteins were identified, and out of them only 7 proteins were found to be expressed in increased amounts in disease and smoker groups as compared to healthy group including haptoglobin, retinol binding protein 4 (RBP 4), alpha-1 antitrypsin, Ig lambda 2 chain C region, Ig alpha-1-chain C region, clusterin, transthyretin (TTR). Haptoglobin and alpha-1-antitrypsin were found to be sequentially increased in healthy control along with smoker, COPD, and lung cancer. The differentially expressed proteins might have a prognostic potential to be used in the progression of COPD to ultimately lung cancer. Impact statement A multistep proteomics fractionation strategy was developed and validated for the discovery of proteomic biomarkers which could be used as potential diagnostic biomarkers for monitoring the progression of disease in smokers and COPD patients towards lung cancer.