Figure 2
UVB-induced skin tumor development was suppressed in hairless fat-1 mice compared with that in WT mice. The female hairless fat-1 or WT mice (n = 10 per group) were irradiated with UVB (180 mJ/cm2) three times a week until termination of the experiment. (A) The photographic images represent papillomas formed at the 23rd week of UVB treatment. (B) Starting four week following UVB treatment, tumors of at least 1 mm diameter were counted every week till the 23rd weeks. The results were expressed as the average number of papillomas per mouse. Results are expressed as means ± SD. ***p < 0.001 versus the UVB-irradiated WT mice. (C) Total RNA was isolated from skin tissues, and mRNA expression of cox-2 was examined by RT-PCR analysis. (D) Whole surrounding tissue extracts (30 μg protein) were analyzed for the expression of COX-2 and P-STAT3 (Tyr705) by immunoblotting. Data are expressed as means ± SE. **p < 0.01 and ***p < 0.001 versus UVB-irradiated WT mice. (E) H&E staining of papillomas showed hypertrophic squamous epithelium forming papillary fronds. The sections of skin tissues were also subjected to immunohistochemical analysis of COX-2 and P-STAT3 (Tyr705). Positive COX-2 and P-STAT3 (Tyr705) staining yielded a brown-colored product. Magnifications, ×100. Scale bar is 100 µm.
