Preliminary study of cytotoxic effects of photodynamic therapy and immunotherapy on human pancreatic cancer cells

Pancreatic cancer is the fourth most common cause of cancer death in the western world. The disease is very resistant to radiotherapy and chemotherapy. One reason for that is the resistance of pancreatic cancer cells to apoptosis. Among the current investigational approaches, targeting human epidermal growth factor receptor (HER-1/EGFR) and interstitial photodynamic therapy (PDT) show promises. When used alone or together, these new approaches might provide an alternative modality to treat pancreatic cancer. This study examined and compared cytotoxic effects of antibody C225 (an anti-HER-1/EGFR monoclonal antibody) and Photofrin-mediated PDT on two human pancreatic cancer cell lines (BxPc-3, HPAF-II). Preliminary in vitro data indicated that these treatments could block various proliferation pathways of pancreatic cancer cells through different mechanisms. For instance, PDT could induce early apoptosis. C225 could induce G1 arrest. These findings might help to design new strategies such as the combination of PDT and immunotherapy for the treatment of pancreatic cancer.