子宫内膜癌靶向药物治疗研究进展

子宫内膜癌的化疗耐药性问题显著,迫切需要新的治疗方案。随着对肿瘤发病机制和信号传导通路的深入研究,以及表观遗传修饰作用机制的阐明,靶向药物研究为子宫内膜癌的治疗提供了新的方法和手段。本文综述了表皮生长因子受体拮抗剂、血管内皮生长因子抑制剂、PI3K/Akt/mTOR通路抑制剂、PD-1/PD-L1抑制剂和表观遗传修饰抑制剂等靶向药物在子宫内膜癌治疗领域的研究进展,为临床用药提供新思路。     

乳腺癌靶向治疗药物的研究进展

目的:了解乳腺癌靶向治疗药物的相关研究进展。方法:依据文献,对分别以人类表皮生长因子受体2(HER-2)、磷脂酰肌醇激酶/雷帕霉素靶蛋白(PI3K/Akt/mTOR)信号通路、细胞周期依赖性激酶、血管新生过程为靶点的4类乳腺癌治疗药物的前沿研究进行综述,并分析其特点。结果与结论:以HER-2为靶点的药物主要有赫赛汀、酪氨酸激酶抑制剂、拉帕替尼以及帕妥珠单克隆抗体;以PI3K/Akt/mTOR信号通路为靶点的药物主要有驮瑞塞尔、依维莫司;以细胞周期依赖性激酶为靶点的药物主要有黄酮吡多;以血管新生过程为靶点的药物主要有贝伐珠单抗。多靶点乳腺癌治疗药物的设计已成为乳腺癌靶向药物研究的前沿和热点。     

酪氨酸激酶及其小分子抑制剂研究进展

近年来，随着分子生物学技术的发展和对发病机制以及细胞分子水平的进一步认识，新药开发已经由传统的底物-受体-基因药理学研究模式向基因-受体-药物这一逆向分子药理学模式转变。而抗肿瘤药物的研究也正从传统的细胞毒药物向着针对肿瘤发生发展机制中多个环节靶向的新型抗肿瘤药物发展，如针对细胞信号传导、凋亡等设计药物。通过阻断酪氨酸激酶可破坏肿瘤细胞的信号传递，从而达到抗肿瘤的目的。因此，近年来有关酪氨酸激酶抑制剂的研究非常活跃，本文将对酪氨酸激酶及其抑制剂的研究进展综述如下。     

mTOR信号传导通路相关蛋白与肿瘤治疗

哺乳动物雷帕霉素靶蛋白基因位于1p36.2上,其mRNA翻译后的蛋白质有2549个氨基酸残基,其分子结构复杂,分子质量为289kDa。mTOR是一种丝/苏氨酸蛋白激酶,通过调节细胞周期、蛋白质合成、细胞能量代谢等多种通路发挥重要的生理功能,在细胞增殖、生长、分化过程中起着中心调控点的作用。此外,mT0R在肿瘤的形成、发展、转移过程中也起着重要作用。在一些肿瘤中可见mTOR通路的持续活动的现象。到目前为止,mTOR抑制药作为靶向性抗肿瘤药物被有效地应用于肾癌及肝癌等治疗。因此,mTOR信号通路的深入研究对肿瘤的靶向治疗具有重要意义。     

HER2蛋白在乳腺癌靶向治疗中的作用及意义

近年来,分子生物学在医学领域得到了充分的发展,分子靶向治疗成为治疗肿瘤的一个新方向。酪氨酸激酶受体家族调控着细胞增殖、分化以及凋亡,与肿瘤的发生与发展密切相关,是一个较为理想的特异性靶点。约有30%的乳腺癌患者出现了人表皮生长因子受体2（HER2）过表达,而HER2受体的活化直接导致了其下游的PI3K/AKT和丝裂原活化蛋白激酶（MAPK）通路被激活,而通过靶向HER2过表达的细胞对肿瘤进行控制成为了一种新的乳腺癌的治疗手段。     

非小细胞肺癌靶向治疗的药物与临床研究

目的：介绍非小细胞肺癌靶向治疗的药物与临床研究进展。方法：采用近期国内外相关文献进行综述。结果：作用于表皮生长因子受体药物和抗血管生成药物以及环氧合酶抑制剂的临床运用，生存期和症状得到改善。结论：随着医学分子生物学技术和理论的进展，针对肺癌发病机制的靶向分子生物学研究，为肺癌治疗开辟了新的途径。     

索拉非尼治疗晚期肾癌的现状

随着临床对肾癌发病机制研究的不断深入,其细胞学、分子生物学领域的不断进展,其细胞信号转导路中的一些关键分子已经成为治疗的靶点,不断有新的分子靶向治疗药物问世,索拉非尼是2005年被美国FDA批准用于晚期肾癌治疗的靶向药物,美国国家综合癌症网络制定的2008年版《肾癌诊治指南》中推荐索拉非尼作为部分患者的一线治疗或者所有患者的二线治疗用药。现就索拉非尼在肾癌晚期的治疗现状、机制及应用前景作一简介。     

分子靶向药物治疗非小细胞肺癌的临床研究刍议

目的:对分靶向药物在非小细胞肺癌治疗的临床研究做了相关介绍。方法:结合国内外相关资料进行了分析研究。结果:在临床治疗当中,作用在表皮生长因子受体药物和环氧合酶抑制剂及抗血管生成药物的综合应用,明显改善了患者的症状和生存期。结论:随着现代医学的进步以及分子生物学理论和技术的进展,采用针对肺癌发病机制的靶向分子生物学研究,为更多的肺癌患者的治疗开辟了一种全新导热治疗途径。     

SIRT1蛋白与mTOR信号通路作为糖尿病及糖尿病并发症治疗靶点的研究进展

糖尿病是全球最普遍的非传染性疾病之一，并且发病率逐年增加，糖尿病及其并发症已经成为全球关注的公共卫生问题，亟需新的、更有效的治疗药物。特殊的生存环境导致了海洋生物独特的代谢途径，因此从海洋环境中寻找新颖的抗糖尿病药物潜力巨大。糖尿病的发病机制非常复杂，其中SIRT1蛋白以及mTOR信号通路在糖尿病的发病机制中发挥了非常重要的作用。本文主要总结了SIRT1蛋白以及mTOR信号通路对糖尿病的调控作用，以期为抗糖尿病海洋药物的筛选提供新的靶点，加快我国“蓝色药库”的开发     

IL-33/ST2信号通路及相关药物研究进展

目的：介绍IL-33/ST2信号通路,总结其与各项疾病的发生发展机制之间的关系以及相关药物的研发进展,为相关疾病的治疗策略提供新的思路。方法：通过汇总分析现有的研究IL-33/ST2信号通路与多种疾病的发病机制关联的文献,对IL-33/ST2信号通路与各项疾病之间的关系以及相关药物的研发进展进行讨论总结。结果与结论：IL-33作为免疫反应和细胞损伤的警报分子,其信号转导通路在过敏性疾病、慢性炎症性疾病、恶性肿瘤和心血管疾病等多种疾病的发病过程中发挥了十分关键的作用,这些研究成果为多种疾病的治疗策略提供了新的思路。多家国内外公司已经开始研发针对IL-33/ST2的靶向药物,绝大多数为单抗药物,且已经进入不同的临床试验阶段,具有重要的应用前景。     

Antiangiogenic treatments and mechanisms of action in renal cell carcinoma

Several angiogenic mechanisms are involved in the pathology of renal cell carcinoma (RCC). Increasing knowledge of angiogenesis and the associated signalling pathways has led to the development of targeted antiangiogenic agents for the treatment of metastatic RCC and the introduction of these agents has significantly improved outcomes for these patients. This article provides an overview of the angiogenic mechanisms implicated in RCC, focusing on the main vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF) and mammalian target of rapamycin (mTOR) signalling pathways. Targeted antiangiogenic agents for the treatment of mRCC include receptor tyrosine kinase inhibitors (such as sunitinib, sorafenib, pazopanib, axitinib, cediranib and tivozanib), monoclonal antibodies (such as bevacizumab) and mTOR inhibitors (such as temsirolimus and everolimus). In this article, we consider the modes of action of these targeted agents and their differing target receptor profiles and we also evaluate how these correlate with their clinical efficacy and tolerability profiles.     

Building on a foundation of VEGF and mTOR targeted agents in renal cell carcinoma

Since late 2005 six new drugs have been approved by the Food and Drug Administration (FDA) for the treatment of metastatic renal cell carcinoma (RCC). However, the similarity of these agents with regard to mechanism of action makes it unclear if each agent has unique clinical utility. This flurry of drug development activity stems from the understanding of the central role that loss of von Hippel Lindau (VHL) gene function plays in the pathophysiology of clear cell RCC. The first agent to establish the therapeutic value of targeting the downstream consequences of VHL loss of function was a vascular endothelial growth factor (VEGF) directed monoclonal antibody, bevacizumab. Following the initial observations with bevacizumab, three VEGF receptor (VEGFR) tyrosine kinase inhibitors, with varied spectra beyond VEGFR, have been successfully developed clinically. Unanticipated clinical activity was observed with inhibitors of mTOR, a central component of the nutrient-sensing PI3 kinase pathway, in RCC. Subsequent work identified that mTOR also regulates the expression of hypoxia inducible factor (HIF), which is regulated by VHL outside of the setting of inactivating mutations or deletions. This appears to tie all of the six approved therapies to the direct consequences of loss of VHL function in clear cell RCC. It remains poorly understood to what extent these therapies differ from one another. Although the outcome of patients with metastatic RCC has been substantially altered with administration of the currently available therapies, the proper selection of currently available therapy, rational development of agents with novel mechanism of action and development of predictive biomarkers of response remains a challenge.     

Promising molecular targeted therapies in breast cancer

In recent years, there has been a significant improvement in the understanding of molecular events and critical pathways involved in breast cancer. This has led to the identification of novel targets and development of anticancer therapies referred to as targeted therapy. Targeted therapy has high specificity for the molecules involved in key molecular events that are responsible for cancer phenotype such as cell growth, survival, migration, invasion, metastasis, apoptosis, cell-cycle progression, and angiogenesis. Targeted agents that have been approved for breast cancer include trastuzumab and lapatinib, directed against human epidermal growth factor receptor 2 (HER2) and bevacizumab, directed against vascular endothelial growth factor (VEGF). Several other targeted agents currently under evaluation in preclinical and clinical trials include inhibitors of epidermal growth factor receptor (EGFR), dual EGFR and HER2 inhibitors, VEGF/VEGFR inhibitors, and agents that interfere with crucial signaling pathways such as PI3K/AKT/mTOR and RAS/MEK/ERK; agents against other tyrosine kinases such as Src, insulin-like growth factor (IGF)/IGF-receptor (IGFR); agents that promote apoptosis such as Poly ADP ribose polymerase inhibitors; agents that target invasion and metastasis such as matrix metalloproteinases inhibitors and others. In this review, we highlight the most promising targeted agents and their combination with mainstream chemotherapeutic drugs in clinical trials.     

Recent advances in small molecule inhibitors of VEGFR and EGFR signaling pathways

Aberrant angiogenesis has been observed in many solid tumors. The formation and metastases of tumors such as non-small cell lung cancer (NSCLC) and renal cell carcinoma (RCC) are very complex, often regulated by proangiogenic factors such as the vascular endothelial growth factor (VEGF) and other tyrosine kinases. The VEGFR, EGFR and mTOR pathways have played critical roles in controlling cell proliferation and angiogenesis. This paper reviews the mechanism and binding modes of recently approved tyrosine kinase inhibitors (TKIs), such as gefitinib, erlotinib, nilotinib, dasatinib, sunitinib, sorafenib, pazopanib, lapatinib, afinitor, and temsirolimus. We also cover the progresses of the recent development of tyrosine kinase inhibitors that are currently in the clinical trials at the phases I, II, and III, targeting the VEGFR, EGFR and/or mTOR pathways. Combination therapy intended to overcome drug resistance is also discussed. Recent TKI design based on the activation loop and the "DFG" conformation, is also discussed.     

Novel pharmacological approaches in the treatment of breast cancer

Breast cancer is the most common malignancy among women. Novel pharmacological agents, including hormonal, cytotoxic and biological therapies, are currently being developed and tested in clinical trials and may offer patients more treatment options and an improved chance of long-term survival. Signal transduction inhibitors that block endocrine or growth factor pathways have demonstrated exciting antitumour effects in clinical trials. In addition to new chemotherapeutic drugs, numerous biological agents including growth factor receptor-directed monoclonal antibodies and tyrosine kinase inhibitors that target specific molecular lesions are being examined as potential breast cancer treatments.     

Targeted therapy in renal cell carcinoma

Hypoxia-regulated genes such as vascular endothelial growth factor (VEGF) and epidermal growth factor (EGF) are both important for tumour progression in renal cell carcinoma (RCC). Drugs that block these and other pathways have been examined in Phase I and II clinical trials in patients with advanced or metastatic RCC. Results from a randomised study of an anti-VEGF antibody demonstrate a delay in the time to disease progression, suggesting a biological effect and change in the natural history of the disease. Results using small-molecule inhibitors of VEGF, FLT3, KIT and platelet-derived growth factor receptor tyrosine kinases, such as sunitinib, show a 40% objective response rate. Results from a Phase III clinical trial with sorafenib, an inhibitor of multiple tyrosine kinases, show only a 2% response rate; however, a statistically significant improvement in progression-free survival was observed. Objective responses have also been noted using an inhibitor of the mammalian target of rapamycin. Conversely, EGF receptor inhibitors, proteosome inhibitors, microtubule stabilising agents, cell-cycle inhibitors and imatinib were also examined with few objective responses. Ultimately, identifying the predictive factors for responsiveness to these targeted therapies may improve the clinical benefit; for example, RCC with biallelic mutations in the von Hippel-Lindau gene would have higher levels of hypoxia-inducible factor-1α, and may be more responsive to inhibitors of angiogenesis. Phase III studies comparing the combinations of targeted therapy could lead to a new standard of care for RCC.     

Rational combination of targeted therapies as a strategy to overcome the mechanisms of resistance to inhibitors of EGFR signaling

The epidermal growth factor receptor (EGFR) has been widely used as a target for novel anticancer agents, such as blocking antibodies and small molecular weight tyrosine kinase compounds. In spite of recent advances in cancer cell biology, leading to the introduction of clinically active new drugs, such as cetuximab, panitumumab and erlotinib, unfortunately disease control remains unsuccessful due to the presence of constitutive resistance to EGFR inhibitors in most patients and the development of acquired resistance in the responders. A large number of molecular abnormalities in tumor cells seem to partly contribute to their resistance to anti-EGFR therapy: increased angiogenesis, constitutive activation of downstream mediators, overexpression of other tyrosine kinase receptors. Moreover, some mutations in the EGFR receptor kinase domain seem to play a crucial role in determining the sensitivity of cancer cells to specific inhibitors by altering the conformation of the receptor and its activity. The development of rational combinations of anticancer agents and EGFR inhibitors, able to exert synergistic cytotoxic interactions, has been widely accepted and used in both preclinical and clinical studies. Although the failure of large clinical trial based on empirical combination of anti-EGFR and classic chemotherapeutic agents, several preclinical data seems to support the hypothesis that combining EGFR inhibitors and other novel agents could efficiently inhibit tumor growth and overcome intrinsic resistance to a single-agent based therapy. This review focuses on the role of complementary signalling pathways in the development of resistance to EGFR targeting agents and the rationale to combine novel inhibitors as anticancer therapy.     

Small molecule tyrosine kinase inhibitors: clinical development of anticancer agents

Numerous small molecule synthetic tyrosine kinase inhibitors are in clinical development for the treatment of human cancers. These fall into three broad categories: inhibitors of the epidermal growth factor receptor tyrosine kinase family (e.g., Iressa? and Tarceva?), inhibitors of the split kinase domain receptor tyrosine kinase subgroup (e.g., PTK787/ZK 222584 and SU11248) and inhibitors of tyrosine kinases from multiple subgroups (e.g., Gleevec?). In addition, agents targeting other tyrosine kinases implicated in cancer, such as Met, Tie-2 and Src, are in preclinical development. As experience is gained in the clinic, it has become clear that unleashing the full therapeutic potential of tyrosine kinase inhibitors will require patient preselection, better assays to guide dose selection, knowledge of mechanism-based side effects and ways to predict and overcome drug resistance.     

Tyrosine kinases as targets in cancer therapy – successes and failures

Protein kinases play a crucial role in signal transduction and also in cellular proliferation, differentiation and various regulatory mechanisms. The inhibition of growth-related kinases, especially tyrosine kinases, might therefore provide new therapies for diseases such as cancer. Due to the enormous progress that has been made in the past few years in the identification of the human genome, in molecular and cell biology technologies, in structural biology and in bioinformatics, the number of receptor and non-receptor tyrosine kinases that have been identified as valuable molecular targets has greatly increased. Currently, more than 20 different tyrosine kinase targets are under evaluation in drug discovery projects in oncology. The progress made in the crystallisation of protein kinases, in most cases complexed with ATP-site-directed inhibitors, has confirmed that the ATPbinding domain of tyrosine kinases is an attractive target for rational drug design; more than 20 ATP-competitive, low molecular weight inhibitors are in various phases of clinical evaluation. Meanwhile, clinical proof-of-concept (POC) has been achieved with several antibodies and small molecules targeted against tyrosine kinases. With Herceptin, Glivec and Iressa (registered in Japan), the first kinase drugs have entered the market. This review describes the preclinical and clinical status of low molecular weight drugs targeted against different tyrosine kinases (e.g., epidermal growth factor receptor [EGFR], vascular endothelial growth factor receptor [VEGFR], platelet-derived growth factor receptor [PDGFR], Kit, Fms-like tyrosine kinase [Flt]-3), briefly describes new targets, and provides a critical analysis of the current situation in the area of tyrosine kinase inhibitors.     

Everolimus restores gefitinib sensitivity in resistant non-small cell lung cancer cell lines

The epidermal growth factor receptor (EGFR) is a validated target for therapy in non-small cell lung cancer (NSCLC). Most patients, however, either do not benefit or develop resistance to specific inhibitors of the EGFR tyrosine kinase activity, such as gefitinib or erlotinib. The mammalian target of rapamycin (mTOR) is a key intracellular kinase integrating proliferation and survival pathways and has been associated with resistance to EGFR tyrosine kinase inhibitors. In this study, we assessed the effects of combining the mTOR inhibitor everolimus (RAD001) with gefitinib on a panel of NSCLC cell lines characterized by gefitinib resistance and able to maintain S6K phosphorylation after gefitinib treatment.Everolimus plus gefitinib induced a significant decrease in the activation of MAPK and mTOR signaling pathways downstream of EGFR and resulted in a growth-inhibitory effect rather than in an enhancement of cell death. A synergistic effect was observed in those cell lines characterized by high proliferative index and low doubling time. These data suggest that treatment with everolimus and gefitinib might be of value in the treatment of selected NSCLC patients that exhibit high tumor proliferative activity.