冬凌草素调控非小细胞肺癌细胞凋亡提高其放疗敏感性的作用研究

发布时间：2019-04-17 14:49

【摘要】：研究背景:外科手术切除是治疗肺癌最有效的方法,但大多数肺癌患者早期多无明显症状,尤其是占80%的非小细胞肺癌(Non-samll cell lung cancer,NSCLC),当确诊时已是中晚期,无法接受根治性手术治疗,只能通过化疗或者局部放疗来延缓肿瘤的进展。因此,以放化疗为主的综合治疗成为中晚期肺癌患者的主要治疗手段。然而,药物和放疗抵抗一直是困扰临床医生的两大难题,其中放疗抵抗相关研究的投入仍略显不足。近来,关于放疗增敏剂的研究成为一大热门课题,但是鲜有中药作为放疗增敏剂的临床研究。冬凌草素亦称冬凌草甲素,是从唇形科植物冬凌草中分离的四环二萜类有效成分,是被广泛认同的具有明显抗癌作用的中草药成分。然而冬凌草素是否能够提高肿瘤细胞对放疗敏感性的相关方面却鲜有报道。本文通过系列实验研究了冬凌草素在肺癌细胞放疗敏感性中的作用及机制,为提高肺癌放疗敏感性提供了新的线索。研究方法:通过MTT法研究肺癌细胞在冬凌草素、放疗以及两者联合治疗条件下的细胞活力程度,通过克隆形成实验研究冬凌草素、放疗以及两者联合治疗对肺癌细胞增殖能力影响,通过Western blot研究冬凌草素在影响肺癌细胞放疗敏感性中的具体分子机制,通过独立样本T检验、方差分析等统计学分析方法对所有统计结果进行统计分析。研究结果:我们首先通过MTT证明冬凌草素能够抑制肺癌细胞的增殖,促进肺癌细胞的凋亡,并且具有时间和剂量依赖性;同时我们证明随着放射治疗剂量的提高,肺癌细胞的凋亡明显增多,增殖明显减弱。其次,我们通过对比检测单纯放疗以及放疗联合冬凌草素对肺癌细胞放疗敏感性的作用,发现冬凌草素能够很大程度上提高肺癌细胞的放疗敏感性;由于肿瘤细胞凋亡在放疗过程中发挥重要的作用,我们猜测冬凌草素是否通过影响肿瘤细胞凋亡从而提高放疗敏感性。通过检测冬凌草素对肺癌细胞凋亡蛋白表达的影响,我们发现凋亡相关蛋白BAX表达明显上调,而凋亡抑制蛋白BCL-2表达明显下调,由此我们证实冬凌草素可能通过调节BAX/BCL-2相关凋亡通路从而提高肺癌细胞的放疗敏感性。结论:冬凌草素不仅能够抑制肺癌细胞的增殖,促进肺癌细胞的凋亡,而且能够提高肺癌细胞的放疗敏感性,从而降低放疗耐受的发生率;冬凌草素通过提高凋亡相关蛋白BAX表达以及降低凋亡抑制蛋白BCL-2的表达,从而促进肺癌细胞凋亡以及肺癌细胞的放疗敏感性。
[Abstract]:Background: surgical resection is the most effective method for the treatment of lung cancer, but most patients with lung cancer have no obvious symptoms in the early stage, especially 80% of non-small cell lung cancer (Non-samll cell lung cancer,NSCLC). Can't receive radical surgery, can only be chemotherapy or local radiotherapy to slow the progress of the tumor. Therefore, the combination of radiotherapy and chemotherapy has become the main treatment for patients with advanced lung cancer. However, drug and radiotherapy resistance have always been two difficult problems for clinicians, in which the investment of radiation resistance related research is still slightly insufficient. Recently, the research on radiosensitizer has become a hot topic, but few traditional Chinese medicine is used as radiosensitizer. Oridonin, also known as Oridonin, is a tetracyclic diterpenoid active ingredient isolated from the labiatae, which is widely recognized as an anti-cancer component of Chinese herbal medicine. However, there is little report on whether oridonin can improve the radiosensitivity of tumor cells. A series of experiments were carried out to study the role and mechanism of Oridonin in radiosensitivity of lung cancer cells, which provided a new clue to improve the radiosensitivity of lung cancer cells. Methods: MTT method was used to study the cell viability of lung cancer cells under the conditions of Oridonin, radiotherapy and the combination of the two, and the clone formation experiment was used to study the cell viability of the lung cancer cells. The effect of radiotherapy and combined therapy on the proliferation of lung cancer cells was studied by Western blot, and the molecular mechanism of Oridonin in affecting radiosensitivity of lung cancer cells was studied by independent sample T test. Analysis of variance and other statistical analysis of all statistical results for statistical analysis. Results: we first demonstrated by MTT that Oridonin can inhibit the proliferation of lung cancer cells and promote the apoptosis of lung cancer cells in a time-and dose-dependent manner. At the same time, we proved that with the increase of radiation dose, the apoptosis of lung cancer cells increased obviously, and the proliferation of lung cancer cells decreased obviously. Secondly, we compared the radiation sensitivity of lung cancer cells treated with radiotherapy alone and the combination of radiotherapy and Oridonin, and found that it could improve the radiosensitivity of lung cancer cells to a great extent. Since the apoptosis of tumor cells plays an important role in the process of radiotherapy, we speculate whether oridonin can improve the radiosensitivity of tumor cells by affecting the apoptosis of tumor cells. By detecting the effect of Oridonin on the expression of apoptosis protein in lung cancer cells, we found that the expression of apoptosis-related protein BAX was up-regulated and the expression of inhibitor of apoptosis protein BCL-2 was down-regulated. Thus we confirmed that eonidin may enhance the radiosensitivity of lung cancer cells by regulating the BAX/BCL-2-related apoptosis pathway. Conclusion: Oridonin can not only inhibit the proliferation of lung cancer cells, promote the apoptosis of lung cancer cells, but also improve the radiosensitivity of lung cancer cells, thus reducing the incidence of radiotherapy tolerance. Oridonin promotes apoptosis and radiosensitivity of lung cancer cells by increasing the expression of apoptosis-related protein BAX and decreasing the expression of inhibitor of apoptosis protein BCL-2.
【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】：R734.2

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