分子靶向抗肿瘤药物研究进展

分子靶向抗肿瘤药物有独特的靶向抗肿瘤作用,在当前临床治疗中已发挥重要作用,并显示出良好的应用前景。根据其分子的大小可将分子靶向抗肿瘤药物分为大分子单克隆抗体类和小分子化合物类,我们简要综述了这2类分子靶向抗肿瘤药物的研究进展。     

肺癌分子靶向药物研究进展

本文就表皮生长因子受体(EGFR)酪氨酸激酶抑制剂、EGFR单克隆抗体、肿瘤血管生成因子(VEGF)受体抑制荆、内皮抑素以及一些多靶点药物等靶向药物在肺癌中的临床研究和应用进行综述。     

肿瘤靶向药物研究进展与展望

肿瘤靶向药物是指与肿瘤发生、生长、转移和凋亡密切相关的分子或基因为靶点而设计的药物,应用肿瘤靶向药物治疗肿瘤是肿瘤治疗的首选策略。     

靶向EGFR家族的抗肿瘤药物研究进展

表皮生长因子受体（EGFR,ErbB）家族在肿瘤的发生、发展中具有重要的作用。很多实体肿瘤中存在EGFR家族受体过表达或异常激活。靶向EGFR家族的抗肿瘤药物研发已经成为一个热点领域,并且成功地应用于临床。靶向EGFR家族的抗肿瘤药物可以分为单克隆抗体和小分子酪氨酸激酶抑制剂两大类。单克隆抗体与受体胞外区结合阻止配体．受体的结合或者阻止配体结合引起的受体活化;而小分子酪氨酸激酶抑制剂则结合于胞内激酶区,抑制激酶自磷酸化和下游信号通路激活。     

分子靶向药物治疗子宫内膜癌的研究进展

子宫内膜癌是我国女性生殖系统第二大恶性肿瘤,在发达国家位居第一位。子宫内膜癌的治疗早期以手术切除为主,辅以放化疗结合其他药物治疗。耐药性大大降低了化疗的成功率,从而增加了疾病复发的可能性。早期和低危疾病患者预后良好,而晚期、复发或转移性子宫内膜癌患者预后极差。目前,现有药物治疗晚期、复发或转移性子宫内膜癌的临床疗效不佳。因此,迫切需要寻找潜在的新靶点和新的治疗方法来提高疗效和改善预后。子宫内膜癌的分子分型有助于识别潜在的药物靶点,为患者的治疗和预后提供更好的临床指导。本文根据子宫内膜癌的分子分型,对子宫内膜癌具有潜在治疗作用的药物靶点和分子靶向药物的研究进展作一综述。     

以Avastin登场为契机 分子靶向药物成为治疗的支柱

在目前不能手术的患者以及复发患者缺乏有效的直肠癌治疗药的情况下，抗血管新生的药物等具有新机理的分子靶向药物相继登场。2005年，Avastin的销售额达到1545亿日元（约合101．97亿元人民币），在业内处于领先地位。分子靶向药物正在成为直肠癌药剂治疗的一支主力军。[编者按]     

以分子开关Ras蛋白为靶点的抗肿瘤药物研究进展

Ras原癌基因编码的蛋白是细胞信号转导中不可或缺的分子开关,在细胞增殖、分化、凋亡等生理过程中起着重要的作用。Ras基因的功能获得性突变是肿瘤发生和发展的重要驱动因素,因此多年来人们一直致力于靶向Ras蛋白的抗肿瘤药物研究。简介Ras的结构与功能及其与肿瘤的相关性,着重综述近年来靶向Ras的小分子抑制剂的研究进展。     

EGFR靶向的PET/SPECT分子成像研究进展

恶性肿瘤的发病率及死亡率逐年递增,分子靶向治疗为癌症治疗带来了新的革命,表皮生长因子受体(EGFR)在癌症发生、发展中发挥重要作用,针对EGFR的分子靶向治疗已成为近年研究热点。目前,已有多种EGFR分子靶向药物应用于临床,但总体有效率偏低。研究表明EGFR过表达和/或突变对治疗效果影响显著,因此治疗前准确评价肿瘤EGFR表达水平及突变状态显得尤为重要。分子成像能够实现活体细胞及分子水平生物学过程成像,并进行定性定量研究,使在体揭示EGFR表达状态成为可能。本文简述EGFR靶向分子成像的研究进展并对不同分子探针成像结果进行比较分析,对不同分子成像探针的功能进行评价,以期有益于EGFR靶向分子成像探针的研发及EGFR靶向分子成像研究。     

新药以分子靶向药物为中心 课题以实现个性化医疗为目的

据推算,全世界每年有100多万人死于肺癌。特别是对化学疗法无效的非小细胞肺癌治疗药的需求十分强烈。在本栏目中介绍过许多具有新的作用机制的分子靶向药物,但要用好这些药物,必须实现个性化医疗。     

GRF78：预测化疗药物疗效及制导肿瘤靶向治疗的分子

葡萄糖调节蛋白78（glucose—regulated protein 78,GRP78）作为分子伴侣的生物学功能已为人们所熟知。但近年来研究人员发现,它与肿瘤的增殖、迁移,以及肿瘤耐药性有密切的关系,因此人们对GRP78的功能有了新的认识。     

生物技术药物市场现状与发展趋势

目的:基于市场角度分析生物技术药物发展现状和未来趋势。方法:检索Thomson Reuters Cortellis数据库、全球医药市场研究机构Evaluate Pharma和美国食品药品监督管理局公布的数据,利用对比分析方法对检索结果进行分析。结果:得益于生物技术药物本身的优势特点,全球生物技术药物市场比例将由2013年的22%增长至2020年的27%,2020年全球市场中罗氏仍然保持最大的市场份额,市场销售额将达435亿美元。尽管中国生物技术药物的市场总额占全球市场的比例仅为2%,但未来发展空间较大,且目前已经形成了以国药集团为龙头的产业集群。结论:随着疾病治疗需求的增加,生物技术药物发展潜力巨大,未来市场将进一步扩大。     

T cells are crucial for the anti-metastatic effect of anti-epidermal growth factor receptor antibodies

Experimental evidences supporting the epidermal growth factor receptor (EGFR) as an important molecule for tumor metastasis had been accumulated. Currently, anti-EGFR monoclonal antibodies (mAbs) constitute a promising approach for the treatment of patients with metastatic tumors. However, the mechanisms associated with the potent anti-metastatic effect of these mAbs have not been completely elucidated due to the lack of appropriate syngeneic preclinical models. In this paper, we have investigated the effects of 7A7, an antibody specific to murine EGFR, on the metastatic properties of D122 murine lung carcinoma. 7A7 mAb significantly impaired metastatic spread of D122 cells in C57BL/6 mice by direct anti-proliferative and pro-apoptotic effects on tumor metastasis. 7A7 mAb capacity to inhibit EGFR activation on D122 cells could contribute to its anti-metastatic effect. In addition, 7A7 mAb was able to induce in vitro antibody-dependent cell-mediated cytotoxicity on D122 cells. Interestingly, 7A7 mAb treatment increased the number of natural killer cells, T lymphocytes and dendritic cells infiltrating the metastatic sites. More strikingly, depletion of CD8⁺ and CD4⁺ T cells in vivo completely abrogated the 7A7 mAb anti-metastatic activity whereas function of natural killer cells was irrelevant. This study supports an in vivo role for T cell response in the mechanism of action of anti-EGFR mAbs, suggesting the induction of an adjuvant effect. This work was supported by the Cuban Government.     

Antigens on rat spermatozoa with a potential role in fertilization

Eight monoclonal antibodies (McAbs), directed against antigens on rat cauda epididymal spermatozoa, were tested for their capacity to interfere with fertilization in vitro as a means of identifying molecules with a potential role in sperm-egg recognition and fusion. Antigens recognized by the McAbs were visualized on live spermatozoa by indirect immunofluorescence (IIF) and characterized by immunoblotting. Five McAbs (designated 1B5, 2C4, 4B5, 5B1, and 8C4) recognized antigens specifically on the sperm acrosome and three (designated 2B1, 2D6, and 6B2) bound to the flagellum. Of the eight McAbs investigated, three (2B1, 2C4, and 6B2) were effective in blocking fertilization in vitro when added as culture supernatants to mixtures of sperm and eggs. McAb 6B2 was inhibitory due to its ability to agglutinate spermatozoa. McAbs 2B1 and 2C4 did not agglutinate capacitated spermatozoa, had no observable effect on motility, and yet blocked fertilization in a dose-dependent manner. McAb 2C4 did not give a reaction on immunoblots, but the 2B1 antigen was identified as an Mr 40 kD glycoprotein. McAb 2B1 appeared to block fertilization at the level of zona binding, whereas the effects of 2C4 were directed more against zona penetration and/or fusion with the vitellus. When sperm-egg complexes were stained with 2C4 or 2B1 McAbs and viewed by IIF, all spermatozoa that were attached to the zona showed fluorescence on the head. These results suggest that different antigens on the rat sperm head participate in different aspects of the fertilization process and that during capacitation there is either exposure of these antigens or else they migrate to their site of action from the flagellum.     

Combinatorial treatments including vaccines,chemotherapy and monoclonal antibodies for cancer therapy

Accumulating evidence suggests that despite the potency of cytotoxic anticancer agents, and the great specificity that can be achieved with immunotherapy, neither of these two types of treatment by itself has been sufficient to eradicate the disease. Still, the combination of these two different modalities holds enormous potential for eliciting therapeutic results. Indeed, certain chemotherapeutic agents have shown immunomodulatory activities, and several combined approaches have already been attempted. For instance, chemotherapy has been proven to enhance the efficacy of tumor cell vaccines, and to favor the activity of adoptively transferred tumor-specific T cells. A number of mechanisms have been proposed for the chemotherapy-triggered enhancement of immunotherapy response. Thus, chemotherapy may favor tumor cell death, and by that enhance tumor-antigen cross-presentation in vivo. Drug-induced myelosuppression may induce the production of cytokines favoring homeostatic proliferation, and/or ablate immunosuppression mechanisms. Furthermore, the recently reported synergy between monoclonal antibodies and chemotherapy or peptide vaccination is based upon the induction of endogenous humoral and cellular immune responses. This would suggest that monoclonal antibodies may not only provide passive immunotherapy but can also promote tumor-specific active immunity. This article will review several strategies in which immunotherapy can be exploited in preclinical and clinical studies in combination with other agents and therapeutic modalities that are quite unique when compared with “conventional” combination therapies (ie, treatments with chemotherapeutic drugs or chemotherapy and radiotherapy based protocols). The results from these studies may have significant implications for the development of new protocols based on combinatorial treatments including vaccines, chemotherapy and monoclonal antibodies, suggesting an exciting potential for therapeutic synergy with general applicability to various cancer types. Given the complicity of immune-based therapies and cancer pharmacology, it will be necessary to bring together cancer immunologists and clinicians, so as to provide a robust stimulus for realizing the successful management of cancer in the near future.     

鼠单克隆抗-HBs的单克隆抗独特型抗体的制备及其免疫原性的研究 Ⅱ.Ab_2—1的免疫原性研究

用一株单克隆抗独特型抗体细胞株,Ab_2-1免疫4只BALB/c小鼠和2只家兔。每只小鼠每次经腹腔接种100#gAb_2-1,共接种4次;每只家兔每次经皮下注射1mgAb_2-1,共注射4次。经免疫的小鼠和家兔都产生了抗-HBs,经两种竞争性抑制试验证实,这些抗-HBs是特异性的。小鼠抗-HBs滴度为2~(-6)至2~(-9);家兔抗-HBs滴度从2~(-10)至2~(-12)。这些资料提示:单克隆抗独特型抗体能模拟HBsAg,具有类似HBsAg的免疫原性。     

高亲和力抗有机磷杀虫剂单克隆抗体的制备与鉴定

制备抗有机磷杀虫剂单克隆抗体。采用人工合成带有特殊功能基团的半抗原,将其与载体蛋白偶联,以半抗原偶联物为免疫原,免疫BALBc小鼠,取免疫小鼠的脾细胞与小鼠骨髓瘤细胞融合,HAT选择、有限稀释法克隆化,建立分泌抗机磷杀虫剂单克隆抗体的杂交瘤细胞系。ELISA间接法和ELISA竞争抑制法检测抗体滴度,非竞争抑制法检测抗体亲和常数。结果获得9株分泌抗机磷杀虫剂单克隆抗体的杂交瘤细胞系,其中7株为型特异性,2株为组特异性;Ig亚型均为IgG1;亲和常数为407×108±043M和127×109±024M。结论为人工人工合成的、含特殊功能基团的半抗原,与载体蛋白偶联后,做免疫原,可用于制备高滴度的抗有机磷杀虫剂单克隆抗体,这种单抗可用于机磷杀虫剂残留物的免疫化学检测 。     

Sulforaphane attenuates EGFR signaling in NSCLC cells

Background

EGFR, a receptor tyrosine kinase (RTK), is frequently overexpressed and mutated in non-small cell lung cancer (NSCLC). Tyrosine kinase inhibitors (TKIs) have been widely used in the treatment of many cancers, including NSCLC. However, intrinsic and acquired resistance to TKI remains a common obstacle. One strategy that may help overcome EGFR-TKI resistance is to target EGFR for degradation. As EGFR is a client protein of heat-shock protein 90 (HSP90) and sulforaphane is known to functionally regulate HSP90, we hypothesized that sulforaphane could attenuate EGFR-related signaling and potentially be used to treat NSCLC.

Results

Our study revealed that sulforaphane displayed antitumor activity against NSCLC cells both in vitro and in vivo. The sensitivity of NSCLC cells to sulforaphane appeared to positively correlate with the inhibition of EGFR-related signaling, which was attributed to the increased proteasomal degradation of EGFR. Combined treatment of NSCLC cells with sulforaphane plus another HSP90 inhibitor (17-AAG) enhanced the inhibition of EGFR-related signaling both in vitro and in vivo.

Conclusions

We have shown that sulforaphane is a novel inhibitory modulator of EGFR expression and is effective in inhibiting the tumor growth of EGFR-TKI-resistant NSCLC cells. Our findings suggest that sulforaphane should be further explored for its potential clinical applications against NSCLC.