淋巴瘤样丘疹病皮损表皮内和真皮内不同表型肿瘤样细胞的同源性及异质性研究及其意义

Lymphomatoid papulosis (LyP) is the second most common cutaneous lymphoma. Its huge contrast between the benign biological behavior and the malignant histological features attracts a lot of researchers. It is recognized that about half of LyP histological type A and type C cases has epidermotropic lymphocytes which morphology are similar to the tumor cells of mycosis fungoides (MF), named MF-like cell and do not express CD30; while the usual tumor cells in the dermis are similar to the Reed-Sternberg (RS) cells of Hodgkin lymphoma (RS-like cell) and express CD30. No research literatures are found about the relationship between the MF-like cells and RS-like cells. Several LyP cases were analyzed about the two kind cells by T-cell receptor gene rearrangement by our group, and our preliminary results showed that they were probably from the same clone. Accordingly, our hypothesis is that the MF-like cells and RS-like cells in LyP lesions are from the same clone originally and the morphological and immunophenotypic difference between them is the results of genetic variation, like gene mutation, gene copy number variation, etc. In order to test our hypothesis, we will first capture the two kind cells by laser captured microdissection, and then contrast their homogeneity and heterogeneity at the DNA level, transcription level and protein level by several research methods. The main significance of this program is that it can help us to understand the nature of LyP better, the gene heterogeneity of the two type cells may become the potential target of gene therapy and it could also contribute to the theory of tumor cell differentiation.

淋巴瘤样丘疹病(LyP)是皮肤第二常见的淋巴瘤，研究发现其组织学类型A型和C型约半数病例有亲表皮现象，亲表皮的淋巴细胞形态上类似蕈样霉菌病（MF）的瘤细胞，CD30阴性；而通常认为的真皮内瘤细胞与霍奇金淋巴瘤的Reed-Sternberg (RS) 细胞相似，CD30阳性。尚未见对这两种细胞关系的研究报道。本课题组对数例LyP的MF样细胞和RS样细胞的T细胞受体基因重排的预实验研究显示二者很可能来源于同一克隆。据此，我们提出假设：LyP皮损内的MF样细胞和RS样细胞来源于同一克隆，由于基因变异导致了它们在形态、免疫表型上的差异。我们将运用激光捕获显微切割技术获取两种细胞，从DNA水平、转录水平和蛋白质水平对它们的同源性和异质性进行对比研究以验证上述假设。本课题的主要意义在于：将促进对LyP本质的认识；两种细胞基因水平的异质性有望成为治疗该病的新靶点；丰富肿瘤细胞分化相关的理论。

通过对23例淋巴瘤样丘疹病（lymphomatoid papulosis, LyP）进行临床病理资料分析，最终确定8例符合实验要求，纳入研究对象，其中LyP A型4例，LyP C型4例。表皮内的蕈样霉菌病（mycosis fungoides, MF）样细胞（简称：MF样细胞）和真皮内的Reed-Sternberg样细胞（简称：RS样细胞）均表达全T细胞标记，如CD3、CD45RO，但MF样细胞不表达CD30、TIA-1、GrB，而RS样细胞表达CD30、TIA1，多数病例表达GrB。8例中有6例(75%)检测到TCRγ基因克隆性重排。LyP A型及C型检出率分别为50%(2/4)、100%(4/4)。LyP表皮内MF样细胞及真皮内RS样细胞TCRγ基因重排检出率分别为75%(6/8)、75%(6/8)。随机选取的1例MF样细胞和RS样细胞均有阳性条带产物的同源性比对分析显示二者同源性达106/108(98%)。据此推测LyP表皮内MF样细胞和真皮内RS样细胞很可能来自同一克隆。此外，我们通过微阵列比较基因组杂交技术(array-based comparative genomic hybridization, aCGH) 对4例LyP冻存组织的全基因组水平上的DNA拷贝数变化进行检测并做差异比对，详细的结果有待进一步分析总结。. 本课题组遵照项目任务计划书的内容，完成了研究内容，部分内容在中华医学会第十九次全国皮肤性病学术年会做分组发言（2013年6月），已整理成论文1篇，投《癌症》杂志（medline收录）。培养硕士研究生1名、博士研究生1名，预计于2015年春季答辩。