雄激素受体介导的青蒿酯对前列腺癌生长的抑制效应研究

发布时间：2018-03-29 14:19

本文选题：青蒿酯　切入点：前列腺癌　出处：《南京医科大学》2017年博士论文

【摘要】：前列腺癌(Prostatic cancer,PCa)是男性最常见的恶性肿瘤之一,在恶性肿瘤的死亡率上排在前列。众所周知,前列腺癌对雄激素敏感,雄激素与前列腺癌细胞上的雄激素受体(androgenreceptor,AR)相结合可以促进肿瘤进展。雄激素去势疗法是目前治疗前列腺癌的标准疗法,在早期可以有效的抑制肿瘤生长。但2～3年内,肿瘤会复发或进展,形成去势抵抗性前列腺癌。目前关于雄激素去势疗法治疗后去势抵抗性前列腺癌发生发展机制研究的文献较多(其中包括类固醇激素代谢的变化、雄激素受体基因的扩增或过表达、雄激素受体辅助调节因子、雄激素受体剪接变异体、生长因子和/或细胞因子、雄激素受体突变等等机制)。目前普遍认为在去势抵抗性前列腺癌中,雄激素和雄激素受体在其发生发展中起到了关键的作用。青蒿酯(Artesunate,ART)是从中药青篙中提取的有过氧基团的倍半萜内酯药物,是传统有效的抗疟药物。经过多年的研究,青蒿酯除了抗疟的作用,还具有明显的抗肿瘤作用。它对诱导肿瘤细胞凋亡、抑制肿瘤细胞增值、调控DNA甲基化转移酶及致癌基因和抑癌基因之间平衡等都有重要的作用。而且,青蒿酯和常规化疗药物相比,副作用较小,没有交叉耐药。研究发现,ART对前列腺癌细胞具有抑制作用,但是具体的作用机制尚不明确。DNA甲基化是哺乳动物中常见的基因组复制后的修饰。在人类多多种生理过程中扮演着重要的角色。DNA甲基化转移酶(DNAmethyltransderase enzymes,DNMTs)是DNA甲基化的主要调节酶。研究发现,DNMT3b在人类肿瘤的发生和发展中起到一定的作用。本研究的主要目的是通过ART与AR的相互作用来推断ART对前列腺癌细胞的作用机制。体外细胞试验及动物试验均采用22RV1前列腺癌细胞株。使用MTT实验测试细胞活性,用TUNEL实验测试细胞凋亡程度。试验中测试细胞AR及DNA甲基化转移酶(DNAmethyltransderase enzymes,DNMTs)的表达变化。在22RV1细胞株的体外及动物试验中发现,ART可剂量依赖型地抑制前列腺癌细胞的生长及活性;促进PCa细胞的凋亡;降低PCa细胞AR的表达;增加DNMTsb及其催化物的表达。进一步研究发现,AR可以下调DNMT3b的表达;增加AR表达或者干扰DNMT3b可以对抗ART诱导的细胞毒作用及凋亡作用。然而,高表达DNMT3b不能改变ART对PCa细胞的效果。由此,我们推断,ART通过AT-DNMT3b通路来抑制PCa细胞生长。ART有可能成为抗前列腺癌的新药。
[Abstract]:Prostate cancer prostatic cancer is one of the most common malignant tumors in men, leading the mortality rate. Prostate cancer is known to be sensitive to androgen. Androgen ovariectomies, the standard therapy for prostate cancer at present, can effectively inhibit tumor growth at an early stage, but within 2 to 3 years, androgen ovariectomies are associated with tumor progression. The tumor will recur or progress, forming ovariectomized prostate cancer. There are many literatures on the mechanism of development of ovariectomized prostate cancer after androgen castration therapy (including the changes of steroid hormone metabolism. Amplification or overexpression of androgen receptor genes, androgen receptor coregulation factors, androgen receptor splicing variants, growth factors and / or cytokines, Androgen receptor mutation and so on. It is widely believed that in ovariectomized prostate cancer, Androgen and androgen receptor play a key role in its development. Artesunate ART, a sesquiterpene lactone with peroxy group, is a traditional effective antimalarial drug, which has been studied for many years. Artemisia annua has obvious anti-tumor effect in addition to its antimalarial effect. It can induce apoptosis of tumor cells and inhibit the proliferation of tumor cells. Regulation of the balance between DNA methyltransferase and oncogenes and tumor suppressor genes plays an important role. Moreover, Artemisia annua has less side effects than conventional chemotherapeutic drugs. There is no cross resistance. Studies have found that art has an inhibitory effect on prostate cancer cells. However, the specific mechanism of DNA methylation is not clear. DNA methylation is a common genome modification in mammals. It plays an important role in many physiological processes of human. DNA methyltransferase DNA methyltransderase transmenses (DNMTs) is DNA methylation. It is found that DNMT3b plays an important role in the occurrence and development of human tumors. The main purpose of this study is to infer the mechanism of ART action on prostate cancer cells through the interaction of ART and AR. 22RV1 prostate cancer cell line was used in cell test and animal test. Cell activity was tested by MTT assay. The apoptosis degree was measured by TUNEL assay. The expression of AR and DNA methyltransderase transducers (DNMTs) were measured. In vitro and in animal experiments, it was found that art could inhibit the growth and activity of prostate cancer cells in a dose-dependent manner. Promote the apoptosis of PCa cells, decrease the expression of AR in PCa cells, increase the expression of DNMTsb and its catalysts. Increasing AR expression or interfering with DNMT3b can antagonize the cytotoxicity and apoptosis induced by ART. However, high expression of DNMT3b can not change the effect of ART on PCa cells. We infer that art may be a new anti-prostate cancer drug to inhibit the growth of PCa cells through the AT-DNMT3b pathway.
【学位授予单位】：南京医科大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：R737.25

【参考文献】