Biological characteristics of gene expression features in pancreatic cancer cells induced by proton and X-ray irradiation

Background: Radiationtherapy is an important alternative treatment for advanced cancer. The aim of the current study was to disclose distinct alterations of the biological characteristics of gene expressionfeatures in pancreatic cancer cells, MIAPaCa-2, following proton and X-ray irradiation.Materials and Methods: Using cDNA microarray, we examined the gene expressionalterations of MIAPaCa-2 cells following proton or X-ray irradiation. We also isolated the surviving MIAPaCa-2 cells after irradiation and analyzed their gene expressionprofiles.Results: Although the cytocidal effects of both types of irradiation were similar at sufficient doses in vitro and in vivo, the affected gene expression profilealterations of MIAPaCa-2 cells irradiated with protons were distinct from those irradiated with X-ray. Interestingly, clustering analysis of gene expressionof the surviving MIAPaCa-2 cells was also completely discernible between the two types of irradiation. However, a similar cytocidal effect was...