Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, MA 02115, USA.
Dis Model Mech. 2009 Sep-Oct;2(9-10):436-9. doi: 10.1242/dmm.004010.
Langerhans cell histiocytosis (LCH) is the unifying designation for a rare proliferative disorder that occurs predominantly in childhood and involves the main antigen-presenting cell of the epidermis. LCH can present in a multitude of ways, from a self-limited rash that resolves spontaneously to a systemic multi-organ disease with a 20% mortality rate. Because some forms behave in a relatively benign manner and are associated with an inflammatory cell infiltrate, it has been proposed that LCH might be a reactive disease. However, its neoplastic nature is suggested by the fact that the proliferating cells in LCH are clonal and overexpress p53. Nonetheless, no recurrent genomic, genetic or epigenetic abnormalities have been identified. Instead, a variety of molecular abnormalities that are consistent with disordered Langerhans cell maturation have been described. A faithful small animal model would aid our understanding of the pathophysiology of LCH but, to date, none exists. Challenges to the creation of a model include the lack of characteristically recurrent genetic abnormalities and the absence of a truly tissue-specific promoter to drive expression of genetic elements solely in Langerhans cells. Still, some of the phenotypic abnormalities in adhesion molecule or chemokine receptor expression might be modeled with sufficient precision to allow the testing of novel therapies.
朗格汉斯细胞组织细胞增生症（LCH）是一种罕见的增生性疾病，主要发生在儿童期，涉及表皮的主要抗原提呈细胞。LCH 可以以多种方式出现，从自行消退的自限性皮疹到 20%死亡率的全身性多器官疾病。由于某些形式的行为相对良性，并与炎症细胞浸润有关，因此有人提出 LCH 可能是一种反应性疾病。然而，LCH 中增殖的细胞是克隆的，并过度表达 p53，这表明其具有肿瘤性。尽管如此，尚未发现复发性基因组、遗传或表观遗传异常。相反，已经描述了各种与朗格汉斯细胞成熟障碍一致的分子异常。忠实的小动物模型将有助于我们理解 LCH 的病理生理学，但迄今为止，还没有这样的模型。创建模型的挑战包括缺乏特征性的复发性遗传异常，以及缺乏真正的组织特异性启动子来仅在朗格汉斯细胞中驱动遗传元件的表达。尽管如此，某些黏附分子或趋化因子受体表达的表型异常可以被精确地模拟，从而可以测试新的治疗方法。
