新型组蛋白去乙酰化酶抑制剂致U251细胞周期阻滞、凋亡及其机制的研究

目的探讨新型组蛋白去乙酰化酶抑制剂(HDACi)2,2,3,3-四甲基环丙酰硫脲(TCCT)诱导人脑胶质瘤U251细胞周期阻滞、凋亡及其作用机制。方法以不同药物浓度与U251细胞共同培养48 h后,采用MTT法检测药物作用48 h后肿瘤细胞的增殖。药物作用24 h后,采用RT-PCR检测肿瘤细胞的p21WAF1/CIP1与Cyclin D1 mRNA的表达,Western blot检测HDAC3、HDAC4、Cyclin D1与p21WAF1/CIP1蛋白的表达,PI单染法分析细胞周期,Annexin V-PI双染法检测肿瘤细胞凋亡。结果 TCCT对U251细胞增殖具有明显抑制作用,药物干预48 h时的IC50为(0.461±0.108)mmol·L-1,并呈现剂量依赖性。TCCT药物干预24 h后U251细胞p21WAF1/CIP1mRNA表达上调,Cyclin D1 mRNA下调;组蛋白去乙酰化酶3(HDAC3)和组蛋白去乙酰化酶4(HDAC4)表达下调,Cyc-lin D1蛋白表达弱下调,p21WAF1/CIP1蛋白表达上调;S期细胞比例明显提高(P<0.05);细胞凋亡率明显增高(P<0.01)。结论 TCCT对U251细胞增殖有明显的抑制作用,引起肿瘤细胞S期阻滞和凋亡。其作用机制可能与其下调HDAC3、HDAC4表达,促进组蛋白乙酰化,而影响p21WAF1/CIP1和Cyclin D1的基因、蛋白的表达有关。     

Carbazole alkaloids as new cell cycle inhibitor and apoptosis inducers from Clausena dunniana Levl

Carbazole alkaloids, 3-methylcarbazole (1), murrayafoline A (2), girinimbine (3), mahanimbine (4) and bicyclomahanimbine (5), were isolated for the first time from Clausena dunniana Levl. by bioassay-guided separation procedure and were identified by spectroscopic methods. Compounds 1 - 5 showed growth inhibitory activity (1, IC₅₀ 25 μg/ml) on human fibrosarcoma HT-1080 cells and cell cycle M-phase inhibitory (2, MIC 0.78 μg/ml) and apoptosis inducing (2, MIC 1.56 μg/ml; 3, MIC 25 μg/ml; 4, MIC 20 μg/ml; 5, MIC 30 μg/ml) activities on mouse tsFT210 cells, respectively, and 2 - 5 provided the first examples of carbazole alkaloids as new cell cycle inhibitors and apoptosis inducers.     

Bortezomib treatment of ovarian cancer cells mediates endoplasmic reticulum stress,cell cycle arrest,and apoptosis

Bortezomib, an approved drug for the treatment of certain haematological neoplasms, is currently being tested in clinical trials as a potential therapeutic agent against several types of solid cancer, including ovarian cancer. We have analyzed the effect of bortezomib on ovarian cancer cells and tissue explants either as a single agent or in combination with carboplatin, taxol, or TRAIL (tumor necrosis factor-related apoptosis-inducing ligand). Bortezomib alone efficiently induced apoptosis in ovarian cancer cells. Apoptosis was preceded by an upregulation of the endoplasmic reticulum stress sensor ATF3, and increased the expression of cytoplasmic heat shock proteins. Bortezomib enhanced the sensitivity of ovarian cancer cells and tissue explants to an apoptosis-inducing TRAIL receptor antibody by upregulating the TRAIL receptor DR5. In contrast to the synergistic effect observed for TRAIL, the efficacy of the taxol treatment was reduced by bortezomib, and bortezomib inhibited the G2/M phase accumulation of ovarian cancer cells treated with taxol. Bortezomib alone or in combination with taxol induced a cell cycle arrest within the S phase, and downregulation of cdk1, a cyclin-dependent kinase that is necessary for the entry into the M phase. Thus, bortezomib can be regarded as a promising agent for the treatment of ovarian cancer and could either be administered as a single agent or in combination with TRAIL. However, a combination treatment with taxanes may not be beneficial and may even be less effective.     

B1, a novel topoisomerase II inhibitor, induces apoptosis and cell cycle G1 arrest in lung adenocarcinoma A549 cells

In our previous studies, we demonstrated that 2,6-bis-(2-chloroacetamido) anthraquinone (B1) showed a highly significant cytotoxic effect. However, its influence in the cell cycle and apoptotic induction effects has not been investigated yet. Here we report the antiproliferative effect of B1, for which IC50 values were 0.57 μmol/l for lung cancer A549 cells, 0.63 μmol/l for colon cancer HT-29 cells, and 0.53 μmol/l for breast cancer MCF-7 cells. DNA topoisomerase II (Topo II), an essential enzyme in DNA synthesis and meiotic division, is highly expressed in cancer cells. Some currently used clinical anticancer drugs (doxorubicin and mitoxantrone) targeting Topo II are very effective antineoplastic agents. B1, sharing the basic structure of known Topo II inhibitors, demonstrated a significant inhibitory effect on Topo II bioactivity. In A549 cells, B1 increased apoptotic cell population with induction of Fas, Bax, and cleaved poly(ADP-ribose) polymerase and by reduction of Bcl-2 expression. Moreover, cell cycle analysis indicated that B1 induced G1 phase arrest through modulation of G1 cell cycle regulatory proteins, such as the downregulation of cyclin D1 and upregulation of Cip/p21, Kip1/p27, and p53. Thus, our study suggests that B1, with the ability to inhibit Topo II activity and cause cell cycle G1 arrest and apoptosis, has potential as a novel anticancer agent.     

表没食子儿茶素对LoVo细胞生长周期的影响和诱导其凋亡的研究

目的探讨表没食子儿茶素对体外培养的人大肠癌ＬｏＶｏ细胞株生长周期的影响以及诱导该细胞凋亡的作用。方法用流式细胞术、琼脂糖凝胶电泳、ＨＥ染色观察表没食子儿茶素处理ＬｏＶｏ细胞后其细胞周期的改变以及细胞凋亡形态学和生化方面的改变。结果表没食子儿茶素在低浓度时（３２．５μｍｏｌ·Ｌ－１）对ＬｏＶｏ细胞的周期有明显的影响，主要是Ｓ期和Ｍ／Ｇ２期明显降低，引起ＬｏＶｏ细胞生长阻滞在Ｇ１期；在较高浓度（１６２．５～３２５μｍｏｌ·Ｌ－１）作用２４ｈ，流式细胞仪ＰＩ染色出现亚二倍体峰，ＨＥ染色可见ＬｏＶｏ细胞有典型的凋亡细胞形态改变：细胞变小变圆、固缩，细胞膜出泡，细胞核固缩、边集和碎裂以及凋亡小体的形成；琼脂糖凝胶电泳呈典型的“梯状（Ｌａｄｄｅｒ）”带。结论表没食子儿茶素对体外培养的ＬｏＶｏ细胞具有抑制和杀伤作用，其机制是通过影响ＬｏＶｏ细胞的生长周期和诱导其凋亡而实现。     

黄直丝链霉菌生产的新的细胞周期抑制剂(-)-脱水亚胺环己酮和l-亚胺环己酮

采用tsFT210细胞的流式细胞术活性筛选模型,通过活性跟踪分离,从黄直丝链霉菌18522发酵物中分离得到两个具有细胞周期抑制活性的化合物,并根据波谱数据和理化性质分别鉴定为(-)-脱水亚胺环己酮(1)和l-亚胺环己酮(2).活性测试结果表明,1和2将tsFT210细胞的细胞周期抑制在G0/G1期,最低有效浓度分别为23.8 μmol/L(1)和10.8 nmol/L(2).化合物1为新天然产物,也是新的亚胺环己酮类细胞周期抑制剂.     

蜂斗菜素对宫颈癌细胞增殖、细胞周期和凋亡的影响

目的 研究蜂斗菜素对宫颈癌细胞增殖、细胞周期和凋亡的影响及潜在机制.方法 以蜂斗菜素0μmol/L为对照,用5、15、45μmol/L的蜂斗菜素处理宫颈癌SiHa细胞,四甲基偶氮唑盐比色法(MTT)检测细胞在24、48和72 h的增殖活性,蛋白质印迹法(Western blotting)检测SiHa细胞中细胞周期蛋白D...     

Flavonoids,phenoxodiol, and a novel agent,triphendiol, for the treatment of pancreaticobiliary cancers

Flavonoids, in particular the isoflavones, are naturally occurring compounds found in soy and textured vegetables that have antiproliferative effects on a variety of cancer types. Phenoxodiol is a derivative of the isoflavone genisten that is 5 – 20 times more potent than genisten. Triphendiol is a derivative of phenoxodiol that has superior anticancer activity against pancreatic and bile duct cancers. This review will focus on the mechanisms of action and activity of two isoflavone derivatives, phenoxodiol and triphendiol, in various tumor types, especially pancreaticobiliary cancers. Triphendiol induces apoptosis in pancreatic cell lines by both caspase-mediated and caspase-independent mechanisms. The addition of triphendiol to gemcitabine is synergistic in in vitro and in vivo models of pancreatic cancer and represents a novel combination of drugs for pancreatic cancer patients.     

环阿尔廷烷型四环三萜化合物对HCT116细胞增殖、细胞周期和凋亡的影响

目的探讨升麻中分离的环阿尔廷烷型四环三萜化合物(KY17)对人结肠癌HCT116(p53WT)细胞增殖、凋亡、细胞周期的影响。方法MTT法测定KY17对小鼠胚胎成纤维细胞(MEF)和HCT116细胞株增殖的影响;检测KY17对HCT116细胞周期的影响;荧光显微镜、流式细胞仪分析细胞凋亡情况;Western blot法检测KY17对细胞凋亡蛋白PARP表达的影响;q PCR法检测miRNA-34a的表达情况。结果KY17处理MEF细胞的IC₅₀值为27.28μmol·L^-1。KY17处理HCT116细胞的IC₅₀值为9.31μmol·L^-1,细胞周期阻滞在G_2/M期,且凋亡蛋白PARP有切割;同时,miRNA-34a上调,p53蛋白表达量增加。结论KY17对HCT116细胞的增殖具有抑制作用,使细胞周期停滞于G_2/M期,最终诱导肿瘤细胞的凋亡,其作用机制与miRNA-34a上调、p53基因激活有关。     

AEG-35156, an antisense oligonucleotide against X-linked inhibitor of apoptosis for the potential treatment of cancer

Aegera, under license from Idera Pharmaceuticals, is developing AEG-35156, a 19-mer phosphorothioate antisense oligonucleotide targeting the caspase inhibitor X-linked inhibitor of apoptosis protein (XIAP) messenger RNA, for the potential treatment of cancer. Several clinical trials are ongoing and include: two phase I monotherapy clinical trials for the potential treatment of cancer and in patients with solid tumors; a phase I combination clinical trial of AEG-35156 with docetaxel in locally advanced, metastatic, or recurrent solid tumors; four phase I/II combination clinical trials for the potential treatment of pancreatic cancer, advanced breast cancer, advanced NSCLC, and acute myeloid leukemia. Mild to moderate adverse effects were observed in early phase clinical trials. Aegera plans to initiate randomized phase III trials if tolerable side effects and evidence of activity are demonstrated in phase I/II clinical trials.     

Cetilistat, a new lipase inhibitor for the treatment of obesity

Alizyme plc, in collaboration with Takeda Pharmaceutical Co Ltd in Japan, is developing cetilistat, an oral non-absorbed synthetic lipase inhibitor, derived from Alizyme's pancreatic lipase inhibitor research program, for the potential treatment of obesity in patients with or without diabetes. It is also under investigation for the potential management of type 2 diabetes. Several phase II clinical trials for obesity have been completed. Phase III trials were in preparation at the time of publication.     

Targeting the cell cycle machinery for the treatment of cardiovascular disease

Cardiovascular disease represents a major clinical problem affecting a significant proportion of the world's population and remains the main cause of death in the UK. The majority of therapies currently available for the treatment of cardiovascular disease do not cure the problem but merely treat the symptoms. Furthermore, many cardioactive drugs have serious side effects and have narrow therapeutic windows that can limit their usefulness in the clinic. Thus, the development of more selective and highly effective therapeutic strategies that could cure specific cardiovascular diseases would be of enormous benefit both to the patient and to those countries where healthcare systems are responsible for an increasing number of patients. In this review, we discuss the evidence that suggests that targeting the cell cycle machinery in cardiovascular cells provides a novel strategy for the treatment of certain cardiovascular diseases. Those cell cycle molecules that are important for regulating terminal differentiation of cardiac myocytes and whether they can be targeted to reinitiate cell division and myocardial repair will be discussed as will the molecules that control vascular smooth muscle cell (VSMC) and endothelial cell proliferation in disorders such as atherosclerosis and restenosis. The main approaches currently used to target the cell cycle machinery in cardiovascular disease have employed gene therapy techniques. We will overview the different methods and routes of gene delivery to the cardiovascular system and describe possible future drug therapies for these disorders. Although the majority of the published data comes from animal studies, there are several instances where potential therapies have moved into the clinical setting with promising results.     

A phenylacetate derivative,SCK6, inhibits cell proliferation via G1 cell cycle arrest and apoptosis

Phenylacetate is a differentiation agent and has anticancer activity with relatively low toxicity. In the present study, we examined the anticancer effect of six synthetic phenylacetate derivatives in human lung cancer cells in our search for more effective phenylacetate analogous. Results showed that the antiproliferative effects of these synthetic compounds were stronger than those of phenylacetate, and that N-butyl-2-(2-fluorolphenyl)acetamide (SCK6) is the most potent compound. To address the mechanism of the antiproliferative effect of SCK6, cell cycle analysis was performed. Result showed that SCK6 (1 mM) induced G(1) arrest in CH27 cells. Western blot analysis of G(1) phase regulatory proteins demonstrated that the protein levels of cyclin-dependent kinase 2 (Cdk2), Cdk4, Cyclin E and Cyclin D3 were decreased after treatment with SCK6 but not those of Cdk6, Cyclin D1 and D2. In contrast, SCK6 increased the protein levels of p53 and p21(CIP1/WAF1). Data from in situ terminal transferase-mediated dUTP-fluorescensin nick end-labeling (TUNEL) assay and DNA fragmentation analysis demonstrated that SCK6 induced apoptotic cell death in CH27 cells. This SCK6-induced apoptosis was accompanied by a downregulation of Bcl-2 protein and activation of the caspase-9 cascade. Overexpression of Bcl-2 by adeno-Bcl-2 vector infection significantly inhibited SCK6-induced apoptosis. Moreover, treatment with caspase inhibitors also markedly reduced cell death induced by SCK6. Taken together, these results suggest that downregulation of G(1)-associated Cdks and cyclins and upregulation of p53 and p21(CIP1/WAF1) may contribute to SCK6-mediated G(1)-phase arrest. Furthermore, the decrease in Bcl-2 and the activation of caspase-9/caspase-3 may be the effector mechanism through which SCK6 induces apoptosis.