295 Rapamycin optimizes photodynamic therapy in squamous cell carcinoma

Skin is the largest organ in human body. UV light exposure responsible for development of Non-melanoma skin cancer, most common type cancer worldwide, classified Basal Cell Carcinoma (BCC) and Squamous (SCC). SCC less but more aggressive invasive than BCC. Lately, Actinic keratosis (AK; its precursor lesion) treatment has been evolving from just resection to non-invasive therapies such as Photodynamic Therapy (PDT). PDT gained relevance due excellent cosmetic results, offering great advantages, considering usual locations SCC: face, neck arms. This therapy based on combining three elements; a photosensitizer (PS), oxygen. PS molecules or precursors once administered, tend be accumulated specifically inside tumor cells. Then, area exposed red light. Due photochemistry reaction, reactive oxygen species are formed triggering cell death. Despite high efficacy, AKs SCCs create relapses. Therefore, there an urgent need optimization. Different studies have demonstrated increase it response when combined with different compounds Vitamin D chemotherapy. In this sense, we proposed drug repositioning Rapamycin (Sirolimus) use adjuvant PDT. mTORC1 inhibitor that interferes protein synthesis cellular metabolism. Dantal et al. observed kidney transplant patients treated prevent rejection had lower incidence. So, evaluated effects lines. We measured efficacy rapamycin combination 2D 3D vitro models. The increases damage compared alone. Trying understand why, measure levels PpIX, endogen PS, conditions, observing higher accumulation. currently studying molecular mechanisms underlying these effects.