Abstract

Photodynamic therapy is an emerging treatment used for certain types of cancer, where a photosensitizer drug generates a phototoxic effect on cells when exposed to light of a certain wavelength. Hexvix is a photosensitizer used in blue light cystoscopy, used to detect bladder cancer facilitating diagnosis and treatment of this disease. This compound is selectively absorbed by cancer cells and not by normal cells. Illuminated with blue light, Hexvix emits red light, resulting in detection of cancer cells. In this work the potential of Hexvix to label and kill multiple cancer cell lines is tested, for potential clinical applications in photodynamic therapy. Here a microscopy cell-based assay was established with automated cell quantification and analysis, to investigate the photodynamic toxicity of Hexvix tested on six cell lines: two non-cancerous (MDCK and HEK293) and four cancer cell lines (bladder cancer (5637), prostate cancer (PC3), colon cancer (SW480) and breast cancer (MDA-MB-231). Results show a higher sensitivity to Hexvix treatment in three cancer cell lines (bladder, prostate and colon cancer) at lower light doses than in non-cancer cell lines. On the other hand, a breast cancer cell line showed low response to the treatment, indicating that the Hexvix phototoxic effect varies between cell types and requires evaluation for each case. The phototoxicity assay presented in this study can be applied as a new clinical diagnostic approach prior to photodynamic treatment.