脾酪氨酸激酶抑制剂的研究进展

非受体型蛋白激酶—脾酪氨酸激酶(Syk)在免疫细胞信号的转导过程中发挥着关键作用,可作为治疗各种过敏性疾病和免疫性疾病的新靶点。本文就近年来文献中报道的小分子Syk抑制剂的结构类型进行分类归纳,对这些抑制剂的构效关系及作用特点等方面的最新研究进行综述。     

受体酪氨酸激酶信号转导途径抑制剂在肿瘤治疗中的应用

肿瘤的发生、发展与细胞内信号转导的紊乱,尤其是受体酪氨酸激酶信号转导途径（ＲＴＫ－Ｒａｓ－ＭＡＰＫ－ＣＤＫｓ）的紊乱有关。作用于该途径的蛋白激酶抑制剂,可阻抑肿瘤细胞增殖信号的细胞内传递,抑制肿瘤细胞增殖 近１０年来．随着一批高效特异蛋白激酶抑制剂的相继研制成功,该类药物在肿瘤治疗中的价值逐渐受到人们重视。本文拟就这方面的研究现状作一综述：１ 肿瘤细胞增殖分化的信号转导途径 调节细胞生长的细胞外信号经细胞膜上受体转导或直接作用于细胞内受体（胞浆或胞核）而发挥生物学效应。尽管ＰＫＡ、ＰＫＣ等细胞内信…     

蛋白酪氨酸激酶信号转导途径与抗肿瘤药物

细胞信号转导(signal transduction)在细胞的代谢、分裂、分化、生物功能及死亡过程中起着重要作用，肿瘤的发生和发展与细胞信号转导过度激活有关。本文简要阐述了蛋白酪氨酸激酶(protein tyrosine kinases，PTKs)介导的信号转导途径，分别介绍了受体酪氨酸激酶介导的Ras/Raf/MAPK和PI-3K/Akt途径，非受体酪氨酸激酶介导的Src、Bcr-Abl和JAK/STAT途径。以此5条信号转导通路中参与的重要蛋白分子为靶点，统计和介绍了相关的已经上市或处于临床研究的抗肿瘤药物。     

酪氨酸激酶类抗肿瘤作用靶点的研究进展

酪氨酸激酶作为抗肿瘤靶点研究广泛,效果良好,在抗肿瘤领域具有广阔的应用前景。目前已发现的蛋白酪氨酸激酶包括20余个受体酪氨酸激酶家族和10余个非受体酪氨酸激酶家族,他们与肿瘤的发生和发展关系密切。本文主要根据近3年的文献,结合酪氨酸激酶与肿瘤的关系,对酪氨酸激酶类靶点及其抑制剂的研究进展作一综述。     

小分子脾酪氨酸激酶抑制剂临床研究进展

脾酪氨酸激酶（Syk）是一种细胞质非受体蛋白酪氨酸激酶,主要在造血细胞中表达。Syk不仅在免疫受体信号中扮演至关重要的角色,同时还调节其他不同的生物功能,包括细胞的黏附、增殖、破骨细胞成熟、血小板活化等方面。近年来Syk在血液肿瘤、自身免疫、炎症疾病等方向已经成为极具吸引力的药物靶标。通过介绍Syk的结构与激活机制,及其信号通路与疾病间关系,对口服小分子Syk抑制剂的临床研究进展进行综述,为其进一步研究与应用提供参考。     

新型蛋白酪氨酸激酶抑制剂类抗肿瘤药物的研究进展

目的探讨蛋白酪氨酸激酶抑制剂抗肿瘤作用机理及其研究进展。方法综述了最新发现的小分子酪氨酸激酶抑制剂的化学结构、抗肿瘤作用及其作用机制及其发展方向等内容。结果结论蛋白酪氨酸激酶与细胞的增殖、分化、迁移和凋亡有着密切的关系,在细胞生命活动的信号转导途径中扮演着十分关键的角色,筛选酪氨酸激酶抑制剂已经成为开发抗肿瘤药物的新途径。     

蛋白酪氨酸激酶抑制剂类抗肿瘤药物的不良反应及疗效性价比

目的：探讨蛋白酪氨酸激酶抑制剂抗肿瘤的不良反应与疗效性价比。方法：回顾性分析2007年1月1日-2008年12月30日的抗肿瘤蛋白酪氨酸激酶抑制剂的不良反应报告。结果：VEGFR引起的不良反应数最好;主要的不良反应的临床表现都是变态反应与消化系统反应;多靶点酪氨酸激酶抑制剂的价值相对较高。结论：蛋白酪氨酸激酶与细胞的增殖、分化、迁移和凋亡有着密切的关系,筛选出合理酪氨酸激酶抑制剂已经成为开发抗肿瘤药物的新途径。     

酪氨酸激酶受体的信号转导途径与肿瘤治疗

许多肿瘤中可见不同酪氨酸激酶受体的过度表达或过度激活 ,如上皮细胞肿瘤中常见ＥＧＦＲ家族受体的过度表达 ,胶质瘤中常见ＰＤＧＦＲ家族受体的过度表达等。这些受体或生长因子的过度表达导致受体的过度激活 ,从而导致其下游信号途径的激活 ,最终导致细胞的转化、增殖和抵抗细胞凋亡、促进细胞生存 ,与肿瘤的发生、发展密切相关。因此 ,许多学者致力于从阻断酪氨酸激酶受体信号转导途径角度来研究新的抗肿瘤药物 ,并已取得巨大突破 ,如针对ＨＥＲ2受体人源化的抗体ＨｅｒｃｅｐｔｉｎＴＭ 已被美国ＦＤＡ批准用于ＨＥＲ2过表达的乳腺癌的…     

新型肿瘤治疗药物--酪氨酸激酶抑制剂

酪氨酸激酶介导的信号转导与肿瘤发生发展直接相关,针对这一途径研发药物已成为当前抗肿瘤治疗的热点,并且取得了重要进展.该文综述酪氨酸激酶的作用机制、酪氨酸激酶抑制剂的临床应用现状及其存在的问题.     

多靶点蛋白酪氨酸激酶抑制剂类抗肿瘤药物的研究进展

多靶点的蛋白酪氮酸激酶抑制剂药物的研究成为近几年来抗肿瘤药物研究的热点。本文整合国内外相关文献资料,简要介绍了该类药物的抗肿瘤作用机理,综合阐述了酪氨酸激酶抑制剂的研究进展。     

Spleen tyrosine kinase (Syk) as a novel target for allergic asthma and rhinitis

Allergic asthma and rhinitis are prevalent diseases in the modern world, both marked by inflammation of the airways. The spleen tyrosine kinase (Syk) plays a critical role in the regulation of such immune and inflammatory responses. Although Syk is best known as a key component of immunoreceptor signalling complexes in leukocytes, recent studies demonstrated Syk expression in cells outside the haematopoietic lineage. Moreover, in recent years, it has been established that Syk is involved in various signalling cascades including those originating from integrin and cytokine receptors. Thus, Syk likely has a much wider biological role than previously recognised. Specific inhibition of Syk using aerosolised antisense oligonucleotides in liposome complexes significantly decreased lung inflammatory responses in experimental asthma and acute lung injury models. In addition, pharmacological inhibitors of Syk have been recently developed with potential for use as therapeutics. However, in the development and the rational delivery of drugs targeting Syk, it is important to consider the multiple cell types that express this kinase and the potential effects of its inhibition on various physiological functions. This review focuses on the recent data and the emerging ideas about Syk as a therapeutic target.     

多靶点蛋白酪氨酸激酶抑制剂的研究进展

肿瘤的发生与发展涉及多种受体或信号通路网络。多项研究结果表明,多靶点药物的治疗效果优于单靶点药物,多靶点抑制肿瘤信号转导是肿瘤防治药物重要的研究方向。本文根据化学结构分类,对多靶点蛋白酪氨酸激酶抑制剂及其发展前景做简要综述。     

治疗免疫性血小板减少症的脾酪氨酸激酶抑制剂fostamatinib

Fostamatinib是美国里格尔制药公司开发的一种口服的脾酪氨酸激酶抑制剂,为成年慢性免疫性血小板减少症患者提供了一个全新的治疗方案。其有效性已经被临床试验充分证实,于2018年5月由美国食品药品管理局（FDA）批准上市。概述了fostamatinib的基本性质、合成路线、作用机制、药动学、药物相互作用和临床研究等内容,以期为该类新药研发以及合理用药提供帮助。     

Immunotoxicity assessment for the novel Spleen tyrosine kinase inhibitor R406

Spleen tyrosine kinase (Syk) is a novel pharmaceutical target for treatment of allergic, autoimmune, and neoplastic disorders. Previous studies have indicated that Syk signaling plays critical roles in regulating the lymphohematopoietic system. These observations prompted us to investigate whether inhibition of Syk would promote immunotoxicity. In a series of studies, rats were treated orally with R406, at dose levels up to and including 100 mg/kg/day (or its prodrug R788 at dose levels up to and including 100 mg/kg/day, reduced to 50 mg/kg/day for females as MTD was exceeded), a potent Syk inhibitor, twice daily for 28 days. In addition to standard toxicological assessments, immunophenotyping by flow cytometric analysis, and a study of humoral immune response measuring anti-KLH IgM and IgG levels, were undertaken. Other immunotoxicity studies included three host resistance models in female Balb/c mice to further ascertain effects of R406 on innate and acquired immunity. Following R406 treatment, expected immunomodulating effects (e.g., decreased thymic and spleen weight, hypocellularity of bone marrow, and reduced lymphocyte counts, including T and B cells) were observed in the rat studies. These changes essentially resolved during a 14-day treatment-free recovery period. A KLH challenge in rats demonstrated no adverse effects on IgG or IgM response. R788/406, administered orally at dose levels up to and including 80 mg/kg/day for 28 days, did not affect bacterial or viral clearance in the Listeria, Streptococcal, or Influenza host resistance mouse models, respectively. This correlated with previous in vitro macrophage and neutrophil function assays (assessing migration, phagocytosis, oxidative burst and microbicidal activity), which revealed that R406 did not adversely affect macrophage or neutrophil function in innate immune responses. Collectively, these results demonstrate that R406 has minimal functional immunotoxicity notwithstanding its lymphocytopenic effect, suggesting that inhibition of Syk might not lead to unacceptable mechanism-based adverse effects.     

Inhibition of the epidermal growth factor receptor tyrosine kinase by PD153035 in human A431 tumors in athymic nude mice

Summary PD153035 is a potent (K_i=6 pm) and specific inhibitor of the epidermal growth factor (EOF) receptor tyrosine kinase that suppresses tyrosine phosphorylation of the EGF receptor in A431 cells at nanomolar concentrations in cell culture. We have examined the pharmacokinetics of this compound and its ability to rapidly suppress phosphorylation of the EGF receptor in A431 human epidermoid tumors grown as xenografts in immunodeficient nude mice. Following a single i.p. dose of 80 mg/kg, the drug levels in the plasma and tumor rose to 50 and 22 M within 15 minutes. While the plasma levels of PD153035 fell below 1 M by 3 hours, in the tumors it remained at micromolar concentrations for at least 12 hours. The tyrosine phosphorylation of the EGF receptor was rapidly suppressed by 80–90% in the tumors. However receptor phosphorylation returned to control levels after 3 hours despite the continued presence of the drug at concentrations which, based on previousin vitro results, were predicted to maintain inhibition. EGF-stimulated tyrosine kinase activity in tumor extracts was decreased and recovered in parallel with the effects of PD153035 on receptor phosphorylation though the activity had reached only about half of the control activity after three hours. These results demonstrate the potential for using small molecule inhibitors to inhibit the EGF receptor tyrosine kinasein vivo, though a fair evaluation of their potential anti-cancer activity will have to wait for solutions to problems with sustained delivery which may allow us to maintain suppression of EGF receptor phosphorylation.     

Novel FLT3 tyrosine kinase inhibitors

Acute myeloid leukaemia (AML) is an aggressive haematological malignancy that is curable in ~ 40% of cases. Activating mutations of the receptor tyrosine kinase FLT3 (FMS-like tyrosine kinase-3) are the single most common molecular abnormalities in AML and are associated with a distinctly worse prognosis. In an effort to target this mutation and improve outcomes in this subgroup of AML patients, several novel small-molecule FLT3 tyrosine kinase inhibitors are currently in development. Some of these FLT3 inhibitors are useful only as laboratory tools, while others clearly have clinical potential. These compounds are derived from a wide variety of chemical classes and differ significantly both in their potency and selectivity. This review summarises these developments and examines these novel agents with regard to both the assays used to characterise them and their clinical potential.     

A tyrosine kinase inhibitor‐induced myocardial degeneration in rats through off‐target phosphodiesterase inhibition

PF‐04254644 is a selective kinase inhibitor of mesenchymal epithelial transition factor/hepatocyte growth factor receptor with known off‐target inhibitory activity against the phosphodiesterase (PDE) family. Rats given repeated oral doses of PF‐04254644 developed a mild to moderate myocardial degeneration accompanied by sustained increase in heart rate and contractility. Investigative studies were conducted to delineate the mechanisms of toxicity. Microarray analysis of Sprague–Dawley rat hearts in a 6 day repeat dose study with PF‐04254644 or milrinone, a selective PDE3 inhibitor, revealed similar perturbation of the cyclic adenosine monophosphate (c‐AMP) pathway. PDE inhibition and activation of c‐AMP were further substantiated using PDE3B immunofluorescence staining and through a c‐AMP response element reporter gene assay. The intracellular calcium and oxidative stress signaling pathways were more perturbed by treatment with PF‐04254644 than milrinone. The rat cardiomyocytes calcium assay found a dose‐dependent increase in intracellular calcium with PF‐04254644 treatment. These data suggest that cardiotoxicity of PF‐04254644 was probably due to activation of c‐AMP signaling, and possibly subsequent disruption of intracellular calcium and oxidative stress signaling pathways. The greater response with PF‐04254644 as compared with milrinone in gene expression and micro‐ and ultrastructural changes is probably due to the broader panel of PDEs inhibition. Copyright © 2012 John Wiley & Sons, Ltd.