Analysis of proteome change before and after carbon ion radiotherapy of non small-cell lung cancer

Carbon ion radiotherapy (CIRT) for non-small cell lung cancer (NSCLC) is an effective and low invasive therapy with an excellent local control rate but there have been few histopathologic observations about the effect of CIRT on the human body. In this study, we aimed to explore peptides that reflect the effect of CIRT on NSCLC with matrix-assisted laser desorption/ionization time-of-flight mass spectrometly (MALDI-TOF MS) serum profiling. We enrolled 36 NSCLC patients who underwent CIRT in our hospital from September, 2006 to February, 2008. Serum samples were collected from these patients before treatment and 1 day and 1, 3, 6 months after treatment. We then prepared 5 μL of serum with magnetic beads and profiled serum proteome using MALDI-TOF MS. Nine peaks showed significant changes before and after treatment. We identified the 2861 Da peak as a fibrinogen alpha chain fragment. The 2861 Da peptide was upregulated soon after irradiation and then declined immediately, and this change was dependent on the dose per fraction. Additionally, 5890 Da and 7738 Da peak are likely to be the peptides which we had identified in our former study. These peaks changed gradually soon after irradiation. These serum peptides were considered to reflect the vital reaction and treatment effect after CIRT. (author)