EGFR突变的非小细胞肺癌耐药机制及其克服新策略

表皮生长因子受体（EGFR）突变的非小细胞肺癌（NSCLC）已被列为一个与临床相关的、独特的肺癌亚群。虽然EGFR突变的肿瘤患者增加了对酪氨酸激酶抑制剂（TKI）的敏感性,但其耐药仍然是一个主要的临床问题。针对原发和获得性耐药不同的分子机制,包括应用第2代或第3代TKI,以及与EGFR下游信号通路抑制剂的组合用药等多项临床试验已经在启动和计划中。本文综述了近年来EGFR突变的NSCLC耐药机制的新进展和克服耐药的新策略。     

EGFR酪氨酸激酶及其抑制剂的研究进展

表皮生长因子受体(EGFR)酪氨酸激酶是细胞外信号传递到细胞内的重要枢纽,它在信号传导、细胞增殖、分化以及各种调节机制中发挥重要作用,并在多种癌细胞中过度表达。许多研究表明,抑制EGFR酪氨酸激酶活性,可抑制肿瘤生长。本文对EGFR酪氨酸激酶及其几种小分子抑制剂在肿瘤治疗中的研究进展作一综述。     

第四代EGFR抑制剂TQB3804的合成工艺研究

目的 改进表皮生长因子受体酪氨酸激酶抑制剂TQB3804的合成路线。方法 以3-氟-4-甲基苯酚为起始原料,经硝化、甲基化得到中间体1-氟-5-甲氧基-2-甲基-4-硝基苯(4);以1-甲基-4-(哌啶-4-基)哌嗪盐酸盐为起始原料,经脱盐酸盐、与中间体4发生亲核取代、硝基还原反应得到中间体2-甲氧基-5-甲基-4-[4-(4-甲基哌嗪-1-基)哌啶-1-基]苯胺(8);以6-氨基喹喔啉(9)为起始原料,经碘代、Buchwald偶联反应、烷基化得到中间体{6-[(5-溴-2-氯嘧啶-4-基)氨基]喹喔啉-5-基}二甲基氧化膦(12),12与中间体8经C-N偶联反应合成目标化合物TQB3804。结果与结论目标化合物及关键中间体的结构经MS和¹H-NMR谱确证,收率为23.6%(以化合物9计),纯度为99.36%(HPLC面积归一化法)。本工艺起始原料价廉易得,后处理操作简单,总收率较高,适合大量制备,为TQB3804及其衍生物的合成工艺研究和工业化生产提供参考。     

EGFR-TKIs在非小细胞肺癌中的耐药机制及诊疗策略新进展

非小细胞肺癌是临床最常见的肺癌类型,不仅发病率较高,致死率也较高,为控制患者病情进展和降低其病死率,既往临床常采用表皮生长因子受体酪氨酸激酶抑制剂(EGFR-TKIs)治疗非小细胞肺癌,虽可有效延长患者生存周期,提高患者生存质量,但随着治疗时间的延长,易引发患者出现耐药性,引发多种不适症状,还会影响治疗效果,可.能加速...     

EGFR-TKIs治疗非小细胞肺癌获得性耐药机制研究进展

表皮生长因子受体酪氨酸激酶抑制剂（EGFR-TKIs)是EGFR敏感突变非小细胞肺癌（NSCLC）的一线治疗药物,但患者在长期使用后不可避免地产生耐药性,已成为影响长期治疗效果的重要不利因素之一。目前研究发现的可能耐药机制包括EGFR突变、旁路信号激活、EGFR下游通路异常激活、上皮间质转换（EMT）、ABC转运体蛋白变化、基因融合以及肿瘤微环境改变等。了解耐药机制有助于开发相应干预治疗方案,提高对NSCLC的治疗效果,改善患者的生活质量。     

表皮生长因子受体酪氨酸激酶抑制剂的耐药机制及其治疗策略

表皮生长因子受体酪氨酸激酶抑制剂在治疗非小细胞肺癌中取得了较好的疗效,但最终仍会出现耐药导致的肿瘤进展。目前的研究发现其中涉及的耐药机制多样,本文就近年来在非小细胞肺癌小分子酪氨酸激酶抑制剂治疗中存在的耐药机制及其治疗策略进行综述。     

表皮生长因子受体-酪氨酸激酶抑制剂分子耐药机制研究

以表皮生长因子受体-酪氨酸激酶抑制剂(EGFR-TKI)为靶点的治疗近年逐渐引起关注。但部分患者在服用EGFR-TKI初期即出现原发和获得性耐药。本文综述EGFR-TKI分子耐药机制的研究现状,探讨EGFR-TKI分子耐药机制重要的临床意义。     

非小细胞肺癌第一代EGFR-TKI耐药后的治疗进展

肺癌是世界上最常见的恶性肿瘤,严重威胁着人们的生命健康。表皮生长因子受体酪氨酸激酶抑制剂(EGFR-TKI)已成为非小细胞肺癌的研究热点。表皮生长因子受体酪氨酸激酶抑制剂为表皮生长因子受体基因突变患者的首选治疗方案,可用于非小细胞肺癌的一线治疗、二线治疗以及维持治疗。但随着疾病的进展,肿瘤不可避免产生耐药,从而导致治疗失败。本文就非小细胞肺癌第一代表皮生长因子受体酪氨酸激酶抑制剂耐药后的治疗作一综述。     

EGFR-TKIs在NSCLC中的耐药机制及治疗策略研究进展

表皮生长因子受体（EGFR）抑制剂是目前临床治疗非小细胞肺癌（NSCLC）的一线小分子靶向药物,随着EGFR酪氨酸激酶抑制剂（EGFR-TKI）的广泛使用,其耐药现象也日趋明显,已成为其治疗NSCLC的巨大挑战。本文总结了EGFR-TKIs在NSCLC中的主要耐药机制,并对相关逆转策略的研究进展进行综述。     

EGFR-TKIs获得性耐药机制及耐药后治疗方案探讨

以表皮生长因子受体酪氨酸激酶抑制剂（EGFR-TKI）为代表的分子靶向药物治疗肿瘤,可明显延长非小细胞肺癌患者的无进展生存期和改善患者的生活质量,但面临耐药以及耐药后如何继续治疗等问题。阐述EGFR-TKI的作用机制和获得性耐药机制,分别对耐药后快速进展、缓慢进展和局部进展3种进展情况提出了诊疗意见,以期为改善耐药、加强疗效提供借鉴。     

表皮生长因子受体家族单克隆抗体耐药机制的研究进展

表皮生长因子受体（EGFR）家族广泛存在于体内各种细胞中,其异常活化与多种人类上皮组织肿瘤的发生、发展密切相关,因此已成为肿瘤治疗的重要靶点之一。目前靶向EGFR家族的药物包括小分子酪氨酸激酶抑制剂和单克隆抗体（简称单抗）类药物,特别是单抗类药物近年来在临床上获得了广泛的应用。但是,越来越多的临床资料表明,大量患者对这类药物表现出原发性耐药或获得性耐药。目前靶向EGFR家族单抗类药物产生耐药的原因主要包括：受体结构改变、血管生成、多种受体酪氨酸激酶的活化、EGFR的亚细胞定位、EGFR下游效应分子的持续激活和EGFR家族生长因子表达的上调等。本文就靶向EGFR家族单抗类药物耐药机制的研究进展进行综述。     

Anti-epidermal growth factor receptor drugs in cancer therapy

The epidermal growth factor receptor is a cell membrane growth factor receptor that plays a key role in cancer development and progression. Epidermal growth factor receptor-activated signalling pathways control cell proliferation, apoptosis, angiogenesis and metastatic spread in the majority of human epithelial cancers. Targeting the epidermal growth factor receptor represents a valuable molecular approach to cancer therapy. Promising strategies in clinical development include monoclonal antibodies which block ligand binding and small molecule inhibitors of the tyrosine kinase enzymatic activity which prevent epidermal growth factor receptor autophosphorylation and propagation of downstream intracellular signals. Several anti-epidermal growth factor receptor agents are in clinical development for cancer therapy. Among these, IMC-225 (cetuximab), a chimeric human-mouse monoclonal IgG1 antibody, OSI-774 (Tarceva^?) and ZD1839 (Iressa^?), two small molecule epidermal growth factor receptor-selective tyrosine kinase inhibitors, are currently in Phase II and III development as single agents or in combination with conventional therapies, such as radiotherapy or chemotherapy. Results from Phase I – II trials in advanced cancer demonstrate that these drugs have an acceptable tolerability and an interesting clinical activity in patients with a variety of tumour types.     

EGFR基因突变与肿瘤靶向治疗

表皮生长因子受体(epidermal growth factor receptor,EGFR)属于受体酪氨酸激酶超家族,在多种恶性肿瘤中表达。配体与EGFR结合诱导形成二聚体和构象变化,活化酪氨酸激酶及信号转导途径,产生细胞增殖、侵润、转移及抗凋亡等效应。EGFR酪氨酸激酶抑制剂(tyrosine kinase inhibitors,TKIs)类靶向药物,如吉非替尼和厄洛替尼等已应用于临床。临床研究显示仅10%~30%患者对TKIs敏感,部分位于EGFR激酶结构域的活化突变与药物敏感性相关。检测EGFR基因突变有助于预测对药物敏感性和提高疗效。随着治疗绝大多数敏感的患者获得继发耐药性,其中约半数有继发突变T790M,降低药物对靶分子的亲和力,其他许多位于EGFR下游信号途径或旁激活途径的分子也参与耐药形成。因此,未来个体化用药和准确预测敏感性,不仅仅要分析EGFR基因,而且要综合考虑下游和其他信号途径的基因,如PI3K,K-RAS,BRAF,MET和PTEN等。     

Epidermal growth factor receptor tyrosine kinase inhibitors in late stage clinical trials

The epidermal growth factor receptor (EGFR) is a cell membrane receptor that plays a key role in cancer development and progression. Ligand-activated EGFR-dependent signalling is involved in cell proliferation, apoptosis, angiogenesis and metastatic spread. Targeting the EGFR, therefore, represents a promising molecular approach in cancer treatment. Several anti-EGFR agents are in clinical development. Three drugs are currently in Phase II and III development as single agents, or in combination with other anticancer modalities: IMC-225 (cetuximab/Erbitux?; ImClone), a chimaeric human–mouse monoclonal IgG₁ antibody, which blocks ligand binding and functional activation of the EGFR; OSI-774 (erlotinib/Tarceva?; Genentech/OSI/Roch) and ZD1839 (gefitinib/Iressa^®; AstraZeneca), two small molecule EGFR-selective inhibitors of tyrosine kinase enzymatic activity, which prevent EGFR autophosphorylation and activation. Iressa is the first EGFR-targeting agent to be registered as an anticancer drug in Japan, in Australia and in the US for the third-line treatment of chemoresistant non-small cell lung cancer (NSCLC) patients. This review will focus on the preclinical background and on the results from the first series of clinical trials with these drugs. Furthermore, continuing clinical trials and a series of open clinical issues for the development of optimal strategies of using EGFR-targeting agents will be discussed.     

Epidermal growth factor receptor inhibitors in non-small-cell lung cancer

The epidermal growth factor receptor (EGFR) is a cell membrane receptor that plays a key role in cancer development and in the progression of many human malignancies, including non-small-cell lung cancer (NSCLC). EGFR-dependent signaling is involved in cancer cell proliferation, apoptosis, angiogenesis, invasion and metastasis. Targeting the EGFR is a valuable molecular approach in cancer therapy. This receptor is overexpressed in up to 80% of NSCLC cases. Thus, several molecules inhibiting this critical biologic pathway have been synthesized and tested as a single agent or in combination with other anticancer modalities in a wide of clinical trials, including reversible and irreversible small tyrosine kinase inhibitors, such as gefitinib and erlotinib, dual vascular endothelial growth factor receptor EGFR tyrosine kinase inhibitors, such as vandetanib (ZD-6474), and monoclonal antibodies, such as cetuximab, which have shown promising activity in patients with NSCLC. This review focuses on the preclinical and clinical results available with EGFR inhibitors in the treatment of NSCLC patients.     

The potential role of the EGFR/ERBB2 heterodimer in breast cancer

Epidermal growth factor receptor (EGFR) and ErbB2 are the best-characterised members of the ErbB family of receptor tyrosine kinases. Both receptors are frequently deregulated in human cancers and both are targets for anticancer drugs. ErbB2 amplification and overexpression are associated with a poor prognosis in breast cancer patients. Over the last decade, evidence has revealed that ErbB2 interacts with EGFR in order to achieve its full oncogenic potential. Therefore, assessment of EGFR and ErbB2 coexpression can potentially predict the outcome of the disease as well as success of therapies better than the assessment of single receptors. Moreover, it is not single-agent therapies, targeting one receptor, but combinations or several receptor-targeted therapies that may be the best way to fight cancer.     

Novel approaches to the development of tyrosine kinase inhibitors and their role in the fight against cancer

Introduction: Protein tyrosine kinase inhibitors are currently one of the most important classes of cancer drugs and one of the most impressive approaches of targeted cancer therapy. Aberrant activation of tyrosine kinase pathways is among the most dysregulated molecular pathways in human cancers; therefore, a large number of tyrosine kinases may serve as valuable molecular targets. To date, several inhibitors of tyrosine kinases have been approved and there are hundreds more compounds that are in various stages of development. Because of the deregulation in human malignancies, the ABL1, SRC, the epidermal growth factor receptor and the vascular endothelial growth factor receptor kinases are among the protein kinases that are considered as prime molecular targets for selective inhibition.

Areas covered: This review focuses on most important small-molecule inhibitors that serve as a model for future development. They also provide a broad overview of some of the new approaches and challenges in the field.

Expert opinion: With the exception of a few malignancies seemingly driven by a limited number of genetic lesions, current targeted therapeutic approaches have shown only limited efficacy in advanced cancers. Consequently, more sophisticated strategies, such as identification of pathogenic ‘driver' mutations and optimization of personalized therapies are needed.