The mTOR-inhibitor Sirolimus decreases the cyclosporine-induced expression of the oncogene ATF3 in human keratinocytes

Cutaneous Squamous cell carcinoma (cSCC) is after basal cell carcinoma the second most common non-melanoma skin cancer and accounts for 20% of all cutaneous malignancies [1]. Particularly effected are organ transplant recipients (OTRs) with a 65 to 250 higher risk than the general population due to their immunosuppression as major risk factor [2]. Moreover, cSCC in OTRs are often quite aggressive with high recurrence rates, metastasis and death [3]. The most widely used agents to prevent graft rejection in solid OTRs are calcineurin-inhibitors in combination with mycophenolate mofetil (MMF) and corticosteroids as the standard triple therapy especially after renal transplantation.