Assessment of Photosensitizer Concentration Effects on the Efficacy of Photodynamic Therapy.

Introduction: Photodynamic therapy (PDT) is an attractive approach in medicine. Due to its noninvasive nature and low side effects, PDT has been developed quickly. In the present study, the gene expression profiles of the human cell line that was treated via PDT in the sub-lethal concentration (LC50) and super-lethal concentration (LC90) of a photosensitizer (PS) from Gene Expression Omnibus (GEO) were extracted and the common differentially expressed genes (DEGs) were investigated. Methods: The gene expression profiles of the treated cells were compared with a control, and the common DEGs were determined. The common DEGs were assessed via protein-protein interaction (PPI) network analysis, and gene ontology enrichment was evaluated. The related biological terms for the common genes were identified. Results: Ninety-four common DEGs were selected to be analyzed. It appeared that the activation and increment of gene expression were prominent processes. Jun, Dusp1, Atf4, and Atf3 as four critical genes were highlighted. "Chromosomal and microsatellite instability in colorectal cancer" was identified as the main class of biological terms related to the assessed DEGs. Conclusion: The major molecular events which happened in both analyses indicated that PDT, independent from the concentration of PS, induced gross molecular changes such as the upregulation of Jun and Dusp1.