Adenin

BCC shave biopsies were obtained from the dermatology department of the university hospital Zürich (USZ). Only material from consenting patients was used for this purpose. After collection, one shave biopsy was cut into 2 pieces, 1 piece was put directly in cell culture insert (Millipore, Cat. No. Z352985), and the other part slow-frozen. The insert was placed in a 6-well plate and the shave biopsy on the insert was cultivated for 5 days with 1.5 ml of co-culture medium only at the bottom. The medium was changed every second day. After 5 days, IHC was performed to measure proliferation (Ki67) and the presence of BCC cells (BerEP4). The co-culture medium is composed as follows: 3 parts DMEM (Gibco, Cat. No. 41966052), 1 part Ham’s F-12 Nutrient Mix (Gibco, Cat. No. 11765054), 10% Fetal Bovine serum heat inactivated (Gibco, Cat. No.1050), 0.1 mg/ml of Normocin^TM (Invivogen, Cat. No. ant-nr-1), 21.8 μg/mL of Adenin (Sigma-Aldrich, Cat. No. A2786), 5.45 μg/mL of Apotransferrin (Sigma-Aldrich, Cat. No. T1147), 2.18 nM of Triiodothyronine (Sigma-Aldrich, Cat. No. T6397), 0.44 μg/mL of Hydrocortisone (Sigma-Aldrich, Cat. No. H0888), 0.11 nM of Cholera toxin (Sigma-Aldrich, Cat. No. C8052), 5.50 μg/mL of Insulin (Sigma-Aldrich, Cat. No. I6634) and 0.01 μg/mL of Epidermal growth factor (Sigma-Aldrich, Cat. No. E4127)