调节自噬增强口腔癌放化疗敏感性的作用机制研究

发布时间：2018-03-06 07:29

本文选题：自噬　切入点：氯喹　出处：《吉林大学》2017年硕士论文　论文类型：学位论文

【摘要】：口腔鳞状细胞癌(oral squamous cell carcinoma,OSCC简称为口腔癌)占口腔颌面部恶性肿瘤的90%以上,全身恶性肿瘤的4%,是世界范围内第六大常见的恶性肿瘤。由于其特殊的解剖学部位、复杂多样的类型以及患者对保留功能和治疗后生活质量的需求,使得口腔癌手术存在肿瘤细胞切除不完全,术后易复发的特点。而放射治疗与手术相比的优势是较少受解剖部位及重要器官的限制,放射野可以足够大,能对已侵入到瘤外组织的散在肿瘤细胞(称为亚临床灶)进行杀灭,并能同时对淋巴引流区进行治疗,因此放射治疗成为口腔癌非手术治疗及术后放化疗的重要组成部分。但是在实际治疗过程中效果不尽如人意,口腔癌细胞对放疗自身产生的以及获得的耐受性,是导致放疗失败的主要原因之一。因此,增强放疗的敏感性、消除或克服肿瘤细胞的放疗耐受性,减轻副作用,是口腔癌临床治疗亟待解决的问题。自噬是通过降解细胞内细胞器和长寿命蛋白来实现氨基酸重复利用和能量循环的一种高度保守的细胞程序。自噬可在应激条件下,清除细胞质内受损的细胞器,回收代谢物质,降低活性氧簇的伤害,修复受损的DNA,保护细胞,促进肿瘤细胞在逆境中的存活,被认为是肿瘤细胞耐受放疗的一种机制。我们前期研究证明,化疗药物顺铂作用于口腔癌Tca83、CAL-27细胞,细胞自噬水平都显著增强。而在顺铂给药前加入自噬抑制剂CQ或3-MA,调节细胞基础水平的自噬,可增强顺铂对口腔癌细胞的杀伤作用,细胞增殖活性明显降低而细胞凋亡率也高于单独应用顺铂。得出高水平的自噬可促进口腔癌细胞凋亡,增强顺铂对肿瘤细胞的杀伤作用。但是细胞自噬是如何参与口腔癌细胞放疗及放化疗抵抗的过程及其机制,国内外研究尚不充分。本研究利用自噬抑制剂氯喹、3-甲基腺嘌呤联合顺铂及电离辐射作用于口腔癌CAL-27和KB细胞株,MTT检测细胞的增殖活性、流式细胞仪检测细胞凋亡以及Western blot检测自噬相关蛋白的表达。通过调节自噬,观察放化疗对口腔癌细胞的杀伤作用并探讨其作用机制,为口腔癌综合治疗提供新思路奠定实验基础。
[Abstract]:Oral squamous cell carcinoma (OSCC) accounts for more than 90% of oral and maxillofacial malignant tumors, and 4 parts of systemic malignant tumors, which are 6th common malignant tumors in the world. Complex and diverse types and the patient's need for retention and quality of life after treatment lead to incomplete resection of tumor cells in oral cancer surgery. The advantage of radiotherapy in comparison with surgery is that it is less restricted by anatomical sites and important organs, and the radiation field can be large enough. It can kill scattered tumor cells (called subclinical foci) that have invaded the extracancerous tissue, and it can also treat the lymphatic drainage area at the same time. Therefore, radiotherapy has become an important part of non-operative treatment and postoperative radiotherapy and chemotherapy for oral cancer. However, the effect of radiotherapy is not satisfactory in the actual treatment process. Therefore, enhancing the sensitivity of radiotherapy, eliminating or overcoming the radiation tolerance of tumor cells, reducing side effects, Autophagy is a highly conserved cellular program that reuses amino acids and circulates energy by degrading intracellular organelles and long-lived proteins. Autophagy can be used under stress. Remove damaged organelles in the cytoplasm, recover metabolites, reduce damage to reactive oxygen species, repair damaged DNA, protect cells and promote survival of tumor cells in adversity. Our previous studies have shown that cisplatin, a chemotherapeutic drug, acts on oral cancer cells Tca83 and CAL-27. The level of autophagy was significantly increased, and the addition of autophagy inhibitor CQ or 3-MAbefore administration of cisplatin could enhance the killing effect of cisplatin on oral cancer cells by regulating the basic level of autophagy. The cell proliferation activity was significantly decreased and the apoptosis rate was higher than that of cisplatin alone. It was concluded that high levels of autophagy could promote apoptosis of oral cancer cells. To enhance the cytotoxicity of cisplatin to tumor cells, but how autophagy participates in the process of radiotherapy and chemoradiotherapy resistance of oral cancer cells and its mechanism. In this study, autophagy inhibitor chloroquine 3-methyladenine combined with cisplatin and ionizing radiation was used to detect the proliferative activity of oral cancer CAL-27 and KB cell lines. Apoptosis was detected by flow cytometry and the expression of autophagy related protein was detected by Western blot. By regulating autophagy, the killing effect of radiotherapy and chemotherapy on oral cancer cells was observed and its mechanism was discussed. To provide a new idea for comprehensive treatment of oral cancer to lay the experimental foundation.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R739.8

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