【作者】 秦莉莉；

【导师】 何建勇； 俞强；

【作者基本信息】 沈阳药科大学 ， 微生物与生化药学， 2006， 硕士

【摘要】 小分子酪氨酸激酶抑制剂和有丝分裂抑制剂均为有效的抗肿瘤药物，对激酶抑制剂和有丝分裂抑制剂的研究与开发已成抗肿瘤药物研究的热点领域。本论文通过对5，8—二取代喹唑啉类化合物LJK-11作用于肿瘤细胞的分子机制的研究，证实了LJK-11是一类新型的具有抑制酪氨酸激酶磷酸化和抑制有丝分裂双重功效的化合物。首先，我们从一系列喹唑啉类化合物中筛选出具有抗肿瘤活性的LJK-11，并对LJK-11作用于肿瘤细胞的信号传导通路进行初步的探索。实验发现LJK-11抑制了不同种类肿瘤细胞的生长并导致其凋亡，并且对HER2磷酸化表达水平有抑制作用，但是对几种常见的，调节细胞生长、分化、代谢和免疫反应的酪氨酸激酶信号传导分子的表达和磷酸化没有明显的影响。通过流式细胞检测，我们发现引起细胞凋亡的原因是LJK-11将细胞阻滞在G2／M期，通过对有丝分裂期的细胞形态观察，发现LJK-11影响了纺锥体的正常形成和染色体正常排列到赤道板上，将细胞阻滞在有丝分裂前中期向中期过渡的阶段。体外微管结合实验证实了LJK-11抑制微管聚合，并且其作用方式与秋水仙素类似。为了进一步了解LJK-11对微管的作用机制，我们选择了几种作用于细胞微管的药物与LJK-11进行联合用药的实验，结果发现LJK-11和秋水仙素共同作用对阻滞细胞到G2／M期有协同作用，但是LJK-11和nocodazole、长春碱等其他抗微管药物既没有协同作用也没有相加作用，并且秋水仙素对细胞有丝分裂的阻滞作用是不可逆的，而LJK-11的作用是可逆的，说明LJK-11与秋水仙素不是同一个微管作用靶点。综合以上结果，可以看出LJK-11既能够通过抑制有丝分裂引起肿瘤细胞的凋亡，又具有受体酪氨酸激酶抑制剂的一些特性，我们推断LJK-11可能是一类新型的具有抑制有丝分裂和抑制磷酸激酶活性双重功效的化合物。对LJK-11诱导肿瘤细胞凋亡的分子机制的研究有助于我们设计出更好的抗肿瘤药物。更多还原

【Abstract】 Tyrosine kinase inhibitors and mitosis inhibitors are powerful anticancer drugs. Research and development of tyrosine kinase inhibitor and mitosis inhibitors have become a hotpot in the research area of anti-anticancer drugs. In this paper, by investigating the molecular effect mechanism of 5, 8-disubstituted quinazolines LJK-11 on cancer cells, we have identified LJK-11, a synthetic analog of 5, 8-disubstituted quinazolines, as a novel mitotic blocker and tyrosine kinase inhibitor.We found that LJK-11 could inhibit growth and induced apoptosis of many different types of tumor cells. LJK-11 inhibited phosphorylation of HER2, but inhibited hardly phosphorylation and expression of tyrosine kinase of AKT, JNK and Pyk2 that regulated proliferation, metabolism, immunoreaction of tumor cells.The immediate cause inducing of cell death was attributed to LJK-11’s effect on the cell cycle. It prevented mitotic spindle formation and arrested cells at G2/M phase. In the presence of LJK-11, the chromosomes are unable to achieve bipolar attachment to the spindle and congress to the metaphase plate. The cells therefore remain blocked at prometaphase/metaphase of mitosis and eventually undergoes apoptosis. Detailed in vitro analysis demonstrated that LJK-11 inhibited microtubule polymerization. The mode of action of LJK-11 on microtubule polymerization resembles most closely that of colchicine.LJK-11 also had synergistic effect with colchicine on blocking cell mitosis. It however had neither synergistic nor additive effect with two other anti-microtubule agents, nocodazole or vinblastine. The effect of Colchicine on cell mitosis was irreversible, but the effect of LJK-11 was reversible. These data suggest that LJK-11 was different from colchicine.In conclusion, LJK-11 represents a novel anti-microtubule and tyrosine kinase-inhibited agent with therapeutic potential in treating cancer. Understanding of the mechanism of LJK-11 on induction apoptosis of tumor cells and its differences from other microtubule polymerization inhibitors will help us to design better anti-cancer drugs.更多还原