Abstract:Objective To simulate natural environmental factors of human skin tumor formation to establish photo-damaged skin tumor models in mice. Methods The study was designed by completely randomized factorial design. BALB / c mice that are light-sensitive were irradiated by UVC(56 mJ/cm2) every other day for 8 weeks and were treated topically with 100 µg of DMBA in 200 µl of acetone once a week until 7 weeks on the dorsal skin area after hair removed. The whole process was 12 weeks. The size and diameter of tumors were observed and measured every week. A dynamic growth-curve of tumor-bearing was depicted. The histopathology features of skin dyed by HE staining, Wright ' s staining and basement membrane were observed to explore Tumor formation and skin morphologic alteration . Results The mice in model group began to form typical epithelial papilloma at 6 week early and the rate of tumor-bearing were up to 100% at 9 week. Then, the number of tumor-bearing developed rapidly and gradually stabilized at 11-12 week to the average number of tumor-bearing up to (4.57±3.0) and the average tumor volume up to (44.91±4.6)mm3. However, the time of tumor happening in DMBA group mice was earlier than model group. The number of tumor-bearing in DMBA group reached a peak at 8.5 week, and then, had a downward trend. Furthermore, tumor spontaneous regression rate were high and the number of tumor-bearing were unstable. Conclusion DMBA is a main factor of the skin tumors modeling. UVC as an independent factor failed to induce skin tumors in the 12-week period. However, the combination of UVC with DMBA has interactive synergy effects on establishment of skin tumor models, which have excellent characteristics of high rate of tumor-bearing, time unified, the large number of harvest and good stabilization. It is a straight, stable and simple experimental tool for anticancer drugs and mechanism study on skin tumor.