长非编码RNA-UCA1调节循环肿瘤细胞抵抗NK细胞杀伤机制的研究

富含肿瘤转移干细胞的循环肿瘤细胞(CTC)在具有高转移潜能的同时，还要具备逃避免疫细胞杀伤的特性才能实现异位种植。为探求CTC共性，课题构建了多发转移的间叶来源骨肉瘤及上皮来源乳腺癌的裸鼠模型，应用磁免液相仪高效分离CTC，与亲本细胞相比，两模型CTC均抗NK 杀伤、高分泌TGFβ、高表达长非编码lncRNA-UCA1及NK抑制受体KIR的配体MHCI类分子。生物信息学分析显示CREB为调控节点，与前期NK多次杀伤诱导瘤细胞免疫逃逸研究crosstalk于HSPs。故提出"UCA1调控CTC免疫逃逸"的假说。本研究拟：1) 调节瘤细胞UCA1水平，检测细胞因子分泌，MHC表达及NK92对其杀伤，证实UCA1参与免疫耐受；2）探寻UCA1自身表达及其调节CREB通路的机制；3)通过裸鼠模型验证相关机制。本研究为阐明LncRNA调节CTC免疫耐受的提供理论基础，为免疫治疗寻找新靶标提供思路。

In order to distant metastasis, circulating tumor cells (CTC), riching in tumor metastasis stem cells, should ont noly have the high metastatic proclivity but also be well-shielded from immune attack . In this project we succeed in constructing multiple metastatic nude mouse model of both mesenchymal derivative osteosarcoma and epithelial originated breast cancer.We innovatively developed the method that efficiently separated CTC. Compared to parental cells, in the both models, CTC high expressed MHCI molecules, and lcnRNA-UCA1, secreted TGFβ, and primary immunotolerance to NK killing effect. Bioinformatics analysis shew that the transcription factor CREB maight be the key factor in this pathway,and participate in the regulation of HSPs. We have proved HSPs play an important role in breast cancer cell acquired immunotolerance induced by NK killing repeatedly in our previors study. On this basis, we put forward a hypothesis, that UCA1 regulates the CTC immunotolerance. Our study maily focus on the following aims: 1)To detect killing ratio of NK92 against CTC upon different expression level of UCA1, and the concentration of cytokines in supernatant and the level of MHC-I molecules will be also quantified; 2) To explore the regulation mechanism of UCA1 self-expression and its regulation role in CREB pathway; 3) Clarify these mechanism in nude mouse modle. In conclusion, the study provides a theoretical basis for clarifying the role of lncRNAs in tumor immunotolerance, and find the new specific target antigen for more effective biological treatment.