研究表明大肠癌（CRC）发生发展与大肠癌干细胞(CCSC)密切相关。CCSC具有自我更新能力、多向分化潜能、治疗抵抗以及强致瘤性等特性，因此阐明维持CCSC特性的分子机制是靶向清除CCSC的基础和前提。我们前期研究首次发现Fas在CCSC中上调，且与组蛋白乙酰化相关。敲除Fas后CCSC克隆球形成能力、干性基因表达以及致瘤能力明显降低，提示Fas可能是促进CCSC特性的重要分子之一,而非促细胞凋亡。但Fas促进CCSC特性的关键分子及如何上调的分子机制迄今未见文献报道。本课题拟在前期研究的基础上，进一步完善Fas在CCSC中的生物学功能；并筛选和鉴定Fas相互作用关键靶分子并解析其生物学功能，以及通过基于光遗传学CRISPR介导的位点特异性组蛋白去乙酰化技术平台来阐明促使CCSC中Fas上调的表观遗传学新机制，由此为靶向清除CCSC提供新靶点，为CRC治疗提供新的策略。

Many studies have shown that the carcinigenesis and progression of colorectal cancer (CRC) are closely associated with the existance of cancer stem cells. Colorectal cancer stem cells (CCSC) are characterized by self-renewal, multi-lineage differentiation potential, chemotherapy resistance and strong tumorigenicity. Therefore, the molecular mechanisms maintaining the characteristics of CCSC is the basis and prerequisite for eliminating CCSC. Our group firstly found that Fas was upregulated in CCSC, and the up-regulation was caused by the acetylation of histone. Studies in vitro and in vivo further confirmed that the traits of CCSC such as sphere-forming, the expression of stem genes and tumorigenesis were suppressed after Fas was knock-down. These results suggest that Fas may be a novel molecule maintaining the characteristics of CCSC rather than promoting the apoptosis of CCSC. However, the concrete molecular mechanisms of Fas involved in maintaining the characteristics of CCSC and the up-regulation of Fas in CCSC have not been reported yet. Based on our previous acheivements, we will complete the biological functions of Fas in CCSC, identify the key partners of Fas, and clarify the new epigenetic mechanisms of Fas up-regulation in CCSC through the light-inducible loci specific histone deacetylation system using optogenetics and CRISPR technology. This study will afford a new target in CCSC interference therapy and generate a novel strategy for CRC therapy.