Therapeutic effect of photodynamic therapy using hematoporphyrin monomethyl ether on human hepatocellular carcinoma cell line HepG_2

Abstract

Objective Photodynamic therapy (PDT) is an effective local cancer treatment, in which a photosensitizer is administered and the tumor is irradiated with light. We examined the effect of PDT using HMME as the photosensitizer, and the 630nm diode laser on human hepatocellular carcinoma cell line HepG_2. Methods HepG_2 cell line was used in all experiments. Cell viability was determined by MTT assay. The percentage of apoptotic cell was determined by flow cytometry following annexin V/PI staining. Two methods were used for the determination of apoptosis: terminal deoxynu-cleotidyl transferase (TdT)-mediated dUTP nick-end labeling assay and laser scanning confocal microscope detection. Results In vitro PDT showed excellent cytotoxicity that was a function of laser energy and drug concentration to the HepG_2 cell lines (P<0. 05). PDT-mediated cell death occurred predominantly by apoptosis in vitro. Conclusion PDT using HMME and the diode laser induces apoptosis in human hepatocellular carcinoma cell lines. It is expected that this therapy will be clinically useful for the treatment of patients with hepatocellular carcinoma. Key words: Carcinoma hepatocellular; Hematoporphyrin monomethyl ether; Photodynamic therapy; Apoptosis