一项研究发现，拥有致癌突变的毛囊干细胞在皮肤受伤的情况下可能引发一种皮肤癌。科研人员已经把人类基底细胞癌（一种有可能导致毁容的皮肤癌）与创伤恢复的缺陷联系在了一起。毛囊干细胞帮助在受伤后再生组织，但是人们仍然不太清楚它们在引发肿瘤方面的作用。Sunny Y. Wong 和Jeremy F. Reiter培育出了转基因小鼠，这些转基因小鼠能产生毛囊干细胞，而这些毛囊干细胞携带的一个基因和基底细胞癌有关，该基因可以打开和关闭。打开这个致癌基因并不足以触发这种小鼠出现癌症，但是在激活这种致癌基因的同时损伤小鼠的背部皮肤的时候，这组科研人员发现含有这种激活的致癌基因的毛囊干细胞迁移到了受伤部位并且在伤口内部形成了上皮癌样肿瘤。此外，这组作者发现这些干细胞甚至能在这种致癌基因打开的几周后出现伤口的时候引发肿瘤。这组作者说，这些发现提示长期存在但是在休眠的位置（诸如毛囊）潜伏的干细胞可能积累致癌突变，直到一个倾覆点（例如受伤） 唤醒了这些细胞并引发肿瘤的形成。

原文出处：

PNAS   doi: 10.1073/pnas.1013098108

Wounding mobilizes hair follicle stem cells to form tumors

Sunny Y. Wong and Jeremy F. Reiter1

Abstract

A wide variety of human cancers are associated with injury. Although stem cells participate in tissue regeneration after wounding, it is unclear whether these cells also contribute to epithelial tumors. Human basal cell carcinomas (BCCs) are associated with misactivation of Hedgehog (Hh) signaling, commonly through acquisition of mutations in Smoothened (Smo). We have found that expression of an activated form of Smo by stem cells of the hair-follicle bulge and secondary hair germ does not induce robust Hh signaling or produce BCCs. However, wounding recruits these cells from the follicle to the wound site, where downstream Hh signal transduction is derepressed, giving rise to superficial BCC-like tumors. These findings demonstrate that BCC-like tumors can originate from follicular stem cells and provide an explanation for the association between wounding and tumorigenesis.