Plasma marker proteins associated with the progression of lung cancer in obese mice fed a high-fat diet.

Recent studies have indicated that obesity increases the risk of developing several types of cancers including lung cancer, which is the leading cause of cancer death worldwide. In the present study, we attempted to discover marker proteins associated with lung cancer progression mediated by treatment of a high-fat diet (HFD) using 2DE combined with MALDI-TOF-MS. Image analysis and further statistical analysis allowed for the detection and identification of 14 proteins, which consequently were classified into two groups based on their regulation patterns in response to diet and tumor. Interestingly, the protein abundances of ten proteins exhibited a synergistic effect when treated with HFD in tumor-bearing mice (Group I). Proteins that had a higher abundance in the plasma of tumor-bearing mice included FGB, Tf, Hpx, Cp, and Hp and the proteins that had a lower abundance included A1AT precursor, PON1, TTRt, and α2-M. These proteins can be used as molecular markers that contribute simultaneously to both obesity and cancer. Four other proteins showed an increase (complement C3 and FGA) or decrease (Apo H and AT III precursor) in the only tumor-bearing mice independently of diet (Group II). The marker proteins identified here may lead to the development of new therapeutics for obesity-causative treatment of lung cancer.