297 Role of TGFβ1 in combination with N-acetyl cysteine in the response of squamous cell carcinoma to photodynamic therapy

In the present study, we aim to understand implications of transforming growth factor β1 secreted by cancer-associated fibroblasts (CAFs) in resistance cutaneous squamous cell carcinoma (cSCC) cells photodynamic therapy (PDT), as well effects combination PDT with N-acetyl cysteine (NAC). is widely used for treatment cSCC, and it involves visible light, molecular oxygen a photoactive compound (photosensitizer), leading death owing generation reactive species. TGFβ1 produced CAFs has been implicated cancer therapies, although its role cSCC not fully addressed yet. Related this, NAC, well-known pulmonary fibrosis, known reduce levels tumor microenvironment. Thus, NAC could improve counteracting CAF derived TGFβ1. To address investigated impact CAF-derived conditioned medium on response PDT. from patients situ invasive were cultured medium, enriched TGFβ1, was subsequently treat two established human lines, A431 SCC13, before exposing them An induction observed but SCC13 cells. Data obtained CGH-arrays Western blot assays shed light mechanisms behind this differential and, interestingly, pre-treatment prevented effect. Overall, our results highlight potential target optimization point promising adjuvant agent cSCC.