UVA Assisted 4-Thiothymidine for Cancer Treatment

This article reviews the developments of 4⁃thiothymidine analogues, assisted with UVA light, as a novel cancer therapy. First, the key points on synthetic chemistry, photochemistry and cellular toxicity of 4⁃ thiothymidine are summarized. As the chemical structure of 4⁃thiothymidine is very similar to that of its parent thymidine, thus 4⁃thiothymidine can be readily incorporated into cellular DNA, and with the help of thymidine kinase, much more preferably into cancerous DNA. Unlike thymidine, 4⁃thiothymdine can absorb strongly in UVA ( longer wavelengths of UV ) light. Thus UVA⁃assisted 4⁃thiothymidine offers an effective cancer treatment. Some underlying mechanisms of action by 4⁃thiothymidine / UVA and compares this cancer approach with the commonly used photodynamic therapy are discussed. The various interactions between 4⁃thiothymidine with human serum albumin are introduced. Finally, a short conclusion on the past efforts and a brief prospect for future work in this exciting research field are given.