Healthy skin rejects cancer

Abstract

Live imaging shows that healthy skin cells surround and expel neighbours that have cancer-promoting mutations, revealing that tissues can recognize and eliminate mutant cells to prevent tumour initiation. See Letter p.334 Cells acquire mutations frequently, but they rarely develop into macroscopic tumours. How the body deals with these defective cells is unclear. Valentina Greco, Slobodan Beronja and colleagues created transgenic mice with skin stem cells carrying genetic mutations known to induce tumour growth. Using intravital imaging, the researchers found that the expression of activated Wnt/β-catenin or oncogenic Hras results in outgrowths, which then regress. The deformation of skin tissue architecture is directly related to the regression of the outgrowths. The dismantling of aberrant structures containing mutant cells requires the activity of neighbouring wild-type cells. The mutant cells are either eliminated or integrated into functional skin appendages. Intriguingly, physical manipulation of the skin tissue architecture using laser tissue ablation is corrected in a similar fashion.