Chemical-induced Two-stage Skin Carcinogenesis Model: An Experimental In Vivo Mouse Model of Skin Cancer

- In experimental cancer mouse models, the induced cancer in the animal resembles human cancer in phenotype. They provide an efficient platform to evaluate the efficacy of potential therapies. To induce a two-step skin carcinogenesis model, first, prep an immunocompromised anesthetized mouse in the prone position. Shave its fur to expose the underlying skin. In the first step, apply a potent tumor-initiating agent on the exposed dorsal skin.

Those hair follicles in their resting or telogen phase, harbor inactive sebaceous glands. The resulting lack of sebum flow allows the accumulation of the compound within these hair follicles. The compound diffuses into the surrounding cells and induces target gene mutation, primarily in the hair follicle stem cells or primary keratinocyte stem cells. The altered gene expression causes tumor initiation in these cells.

In the second step, apply a suitable tumor growth-promoting agent on the dorsal skin repeatedly during the desired time intervals. The chemical stimulates the expansion of the initiated cell population. The continued cell proliferation leads to the formation of carcinogenic outgrowths called papillomas.

In the following protocol, w