Enhancement of cytotoxic effect on human head and neck cancer cells by combination of photodynamic therapy and sulforaphane.
Gen Physiol Biophys. 2015 Jan ;34(1):13-21. Epub 2014 Nov 14. PMID: 25395599
Sang J Lee
Photodynamic therapy (PDT) is a method to treat cancers using photosensitizer and light. PDT has been tried for several tumors. However, the clinical applications are limited by the toxicity of photosensitizer and narrow effect. Sulforaphane (SFN) is a material of isothiocyanate group and known to have anticancer effect. We evaluated the cytotoxic effect of PDT combined with SFN on human head and neck cancer cells. We measured the cell viability, extent of apoptosis and necrosis, reactive oxygen species (ROS) generation and caspase activation. Cell viability was decreased significantly by combination treatment. Cellular apoptosis and necrosis were increased in combination treatment compared to SFN or PDT. ROS generation was also higher in combination treatment than single treatment. In combination treatment group, apoptosis and necrosis were decreased by administration of sodium azide (SA) which is scavenger of ROS. Increased caspase activation in combination treatment was also inhibited by SA. Combination of PDT and SFN led to enhanced cytotoxic effect on head and neck cancer cells. Combination treatment promoted the ROS generation, which induced cell death through activation of caspase pathway.