CYLD调控皮肤鳞状细胞癌癌症干细胞并影响其分化程度的机制

The major function of CYLD is to remove ubiquitin from its substrates such as Traf 2/6, Bcl3, and Nemo and modify their functions. CYLD is recognized as a critical tumor suppressor since it negatively regulates oncogenic pathways such as NF-kB, TGF-beta, WNT, Bcl3, JNK and leads to suppression of tumor growth. Our preliminary study shows that loss of CYLD leads to an increase number of cancer stem cells (CSCs) and the CSCs are more tumorigenic. However, whether CYLD inhibits the SCC progression by affecting the selfrenewal and differentiation of CSCs is unknown. In order to study the CYLD regulations on CSCs by in vivo and in vitro assays, we will isolate CD34high а6 integrinhigh N-cadherinhigh/low CSCs with or without CYLD expression from squamous cell carcinoma (SCC) tissues and compare their in vivo tumor initiating effect in immune-compromised nude mice. We will determine the symmetrical and asymmetrical cell divisions by immune fluorescence to explore the mechanisms of CYLD effect on CSCs. Moreover, the CYLD expression in human SCC tissues and their correlations with pathological stages, prognosis, and metastasis will be studied.

CYLD的主要生物功能是去掉一些重要底物分子如Traf2/6, Bcl3, Nemo等的泛素而改变它们的功能。CYLD通过负调控一些致肿瘤分子信号传导如NF-kB,TGF-β,WNT,Bcl3,JNK等导致细胞增殖抑制。我们前期的实验显示小鼠CYLD缺失导致致癌剂诱导的小鼠皮肤鳞状细胞癌癌症干细胞增多并有较强的致肿瘤特征。CYLD是否通过影响癌症干细胞的自我更新和分化而抑制皮肤癌的生长未见报道。我们将用流式细胞仪分离肿瘤组织中CD34highа6 integrinhighN-cadherinhigh癌症干细胞以观察它们在免疫缺陷小鼠中的致肿瘤特征和在有或无CYLD存在时的区别。我们将用免疫荧光染色方法对皮肤癌细胞系中对称和非对称细胞分裂进行检测以探讨CYLD缺失时癌症干细胞增多的分子机制。此外，还用免疫组化方法检测CYLD在人皮肤癌组织的表达并研究其与临床病理分化程度、预后和转移癌的关系。

CYLD被认为是关键的肿瘤抑制基因是因为其负调控一些致肿瘤分子信号传导如NF-kB、TGF-beta、WNT、Bcl3、JNK等导致细胞增殖抑制。实验显示小鼠CYLD缺失导致致癌剂诱导的小鼠皮肤鳞状细胞癌癌症干细胞增多并有较强的致肿瘤特征。CYLD如何通过影响癌症干细胞的自我更新和分化而抑制皮肤癌的生长深层机制未曾明瞭。我们用免疫荧光染色方法和western-blot方法对皮肤癌细胞系处理后进行检测以探讨CYLD缺失时癌症干细胞增多的分子机制。还用免疫组化方法检测CYLD在人皮肤癌组织的表达及研究其与临床病理分化程度、预后和转移癌的关系。我们首次发现NHRF1上调以及MGST1下调是CYLD调节肿瘤干细胞的重要途径之一。该研究揭示了CYLD在皮肤癌细胞的缺失导致恶性侵袭性皮肤癌的机制并探讨了应用CYLD作为皮肤癌的预后标志物的可能。 此外，我们对另一重要的皮肤肿瘤，恶性黑色素瘤的黑色素含量和NLK的表达与临床病理分期和肿瘤转移的关系进行了初步的研究。