IOCAS-IR
协同索拉非尼抗肝癌活性物质的筛选及作用机制研究
刘格
学位类型博士
导师孙超岷 研究员
2018-05-04
学位授予单位中国科学院大学
学位授予地点中国科学院海洋研究所
学位名称理学博士
学位专业海洋生物学
关键词抗肝癌鸡尾酒式药物,索拉非尼,sps170,gl22,eps364
摘要

  肝癌是最常见的恶性肿瘤之一,是严重的公共健康问题,约占所有人类癌症
的6%,全球每年有超过70 万的新病例被确诊,并且每年引起全球100 万人的死
亡。虽然可以手术切除局部肿瘤的肝癌患者的预后较好,但是肝癌患者的五年生
存率平均仅有30-40%。因此,寻找新的肝癌治疗策略势在必行。
  多激酶抑制剂索拉非尼是唯一一个被 FDA 批准的用于治疗中晚期肝癌的药
物。研究称,索拉非尼能够抑制肿瘤细胞的生长增殖和血管生成从而发挥其抗肝
癌作用。然而在临床使用中,索拉非尼的严重副反应,包括腹泻、高血压、恶心
和皮肤毒性等严重降低了病人的生活质量并限制了其治疗效果。此外,索拉非尼
在治疗过程中已出现获得性耐药,严重影响了其药效的发挥。为了降低索拉非尼
的毒性和耐药性,行之有效的策略就是协同其他抗肝癌药物来降低索拉非尼的临
床用药量、同时维持良好的治疗效果,也即发展抗肝癌鸡尾酒式药物。
  在本文中,我们分别从海藻多糖库、灵芝化合物库和海洋微生物多糖库中筛
选具有良好抗肝癌活性且能与索拉非尼具有协同抗肝癌作用的活性物质,得到了
马尾藻多糖SPS170、灵芝三萜类化合物GL22 和海洋细菌胞外多糖EPS364,并
初步揭示了它们体外抑制肝癌细胞Huh7.5 生长增殖的作用机制。
  我们的研究结果表明,索拉非尼可在 Huh7.5 细胞中引起线粒体损伤、ATP
产量降低、激活ATP-AMPK-mTOR-SREBP1 信号通路、下调SCD1 的表达水平、
降低单不饱和脂肪酸的含量,最终抑制肝癌细胞的增殖并促进其死亡,进而发挥
其显著的抗肝癌作用。马尾藻多糖SPS170 可以以时间和剂量依赖的方式抑制
Huh7.5 细胞的生长增殖,诱导Huh7.5 细胞的凋亡、线粒体膜电位的降低和活性
氧的产生;SPS170 还能上调Huh7.5 细胞Bax/Bcl-2 比率并激活caspase-3/9 和PARP;此外,SPS170 还能在体外抑制HUVEC 细胞的增殖、迁移和管腔形成,
并在体内抑制斑马鱼新生血管生成。分离于西藏珍稀白肉灵芝的三萜类化合物
GL22 能够在体内和体外显著地抑制Huh7.5 细胞的生长增殖。GL22 在Huh7.5
细胞中通过影响PPAR-FABPs(脂肪酸结合蛋白)信号通路从而抑制FABPs 蛋
白的表达,扰乱了细胞内自由脂肪酸的转运,降低了心磷脂的生物合成和稳态含量,进而引起线粒体的形态异常和功能紊乱,并最终导致了细胞死亡。海洋细菌
胞外多糖EPS364 分离于海洋溶藻弧菌364 号菌株,它能够抑制Huh7.5 细胞的
生长增殖,并能明显地引起体外培养的Huh7.5 细胞的聚集成团和伪足消失;ECM
(细胞外基质)受体和细胞粘附分子相关信号通路是EPS364 影响Huh7.5 细胞
中最为关键的信号通路。
  抗肝癌鸡尾酒式药物是指联合使用两种或两种以上不同作用机制的具有协
同作用的药物来治疗肝癌,一方面增加了单一药物给药的治疗效果同时降低了单
一药物的给药用量,另一方面显著减少了高给药剂量的药物带来的严重副作用,
提高了病人的生活质量。抗肝癌鸡尾酒式药物的发展在未来的肝癌治疗中将发挥
重要的作用,我们的研究将会为基于索拉非尼的抗肝癌鸡尾酒式药物的开发提供
理论依据。

其他摘要

Liver cancer is a serious health problem, with more than 700,000 new cases
diagnosed worldwide annually. Liver cancer is one of the most common malignancies,
accounting for about 6% of all human cancers and one million deaths worldwide each
year. Although the prognosis of patients with a surgically-resectable localized tumor is
better, the five-year survival rate of patients with liver cancer is only 30-40%.
Therefore, there is an urgent need to find novel treatment strategies for liver cancer.
Sorafenib (multikinase inhibitor) is the only drug approved by the FDA for the
treatment of advanced liver cancer. It has been reported that sorafenib could display
significant anti-hepatocellular carcinoma (HCC) activity through inhibiting tumor cell
growth and angiogenesis. However, the severe side effects of sorafenib, including
diarrhea, nausea and skin toxicity, severely lower the life quality of patients and limit
its therapeutic efficacy in clinical use. Acquired drug resistance to sorafenib has been
severely hampering its applications during treatment of HCC. One approach for
reducing the toxicity and drug resistance of sorafenib is to use lower doses of
sorafenib in combination with other anti-HCC agents. That is to say, to develop a
cocktail of anti-HCC drugs.
To obtain active substances with good anti-HCC activiy and acting
synergistically with sorafenib in the inhibition of HCC, screening from libraries of
seaweed polysaccharides, Ganoderma compounds, and marine microbial
exopolysaccharides was conducted in our study. And we screened a novel
polysaccharide from Sargassum integerrimum (SPS170), a triterpenoid from
Ganoderma lucidum (GL22) and an exopolysaccharide from marine Vibrio
alginolyticus (EPS364). The molecular mechanisms of the growth inhibition on
Huh7.5 cells in vitro were studied in our research.
Our results show that sorafenib causes mitochondrial damage, desearse of ATP
production, activation of the ATP-AMPK-mTOR-SREBP1 pathway, down-regulation
of SCD1 expression, reduction of monounsaturated fatty acid contents, and finally
growth inhibition and cell death in Huh7.5 cells. SPS170 significantly reduces Huh7.5
cells viability in a dose- and time-dependent manner. SPS170 induces cell apoptosis,
the loss of mitochondrial membrane potential (MMP), and generation of reactive
oxygen species (ROS). Up-regulation of the expression of P53, increase in the ratio of
Bax/Bcl-2, and activation of cleaved caspase-3, caspase-9 and PARP are also detected
after the treatment of SPS170. In addition, SPS170 inhibits the proliferation,
migration and cord formation of human umbilical vein endothelial cells (HUVECs) in
vitro, and prevents the vascular development of zebrafish embryos in vivo. GL22
displays robust antitumor activity against Huh7.5 cells in vitro and in vivo. GL22
affects PPAR-FABPs pathway and inhibits the expression of FABPs, leading to
disrupted FA transport, reduced cardiolipin synthesis, mitochondrial dysfunction and
cell death. EPS364, isolated from the Vibrio alginolyticus 364, significantly inhibits
the proliferation of Huh7.5 cells, induces cell aggregation and disappearance of
filiform structures. ECM-receptor and cell adhesion molecules signaling pathways are
those that change significantly in GL22-treated Huh7.5 cells.
Anti-HCC drugs cocktail therapy is a combination of two or more drugs that
target the HCC in different ways and act synergistically in the inhibition of HCC. On
the one hand, it potentiates the therapeutic effects of these drugs on HCC and reduces
the drug dosage. On the other hand, it significantly lowers the serious side effects of
high-dose drugs and improves the life quality of patients. The development of
anti-HCC drugs cocktail therapy will play an important role in treatment of HCC in
the future. Our research will provide theoretical basis for future development of
anti-HCC drugs cocktail therapy.

学科领域生物学
学科门类理学
语种中文
文献类型学位论文
条目标识符http://ir.qdio.ac.cn/handle/337002/154456
专题中国科学院海洋研究所
第一作者单位中国科学院海洋研究所
推荐引用方式
GB/T 7714
刘格. 协同索拉非尼抗肝癌活性物质的筛选及作用机制研究[D]. 中国科学院海洋研究所. 中国科学院大学,2018.
条目包含的文件
文件名称/大小 文献类型 版本类型 开放类型 使用许可
博士毕业论文-MS-刘格-最终版-网上维(5995KB)学位论文 延迟开放CC BY-NC-SA2019-6-30后可获取请求全文
个性服务
推荐该条目
保存到收藏夹
查看访问统计
导出为Endnote文件
谷歌学术
谷歌学术中相似的文章
[刘格]的文章
百度学术
百度学术中相似的文章
[刘格]的文章
必应学术
必应学术中相似的文章
[刘格]的文章
相关权益政策
暂无数据
收藏/分享
所有评论 (0)
暂无评论
 

除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。