抗HER2抗体的作用机制研究进展

生长因子受体家族通过与各种配体相互反应及家族成员间的相互作用介导细胞的信号转导，HER2属该家族成员，25％～30％的乳腺癌患者HER2过表达，而HER2过表达与肿瘤的侵袭性及不良预后有关。曲佐单抗(trastuzumab)是第一个应用于治疗HER2过表达的乳腺癌患者的人源化单克隆抗体，临床试验结果表明，曲佐单抗对HER2过表达的乳腺癌患者有确切疗效。但是，抗HER2抗体的作用机制尚不十分清楚。本文综述了其有关研究进展，包括HER2表达下调、阻止HER2异二聚体形成、诱导G1期阻滞和p27表达、阻止HER2胞外区结构域的脱落和诱导机体免疫反应等抗体可能的作用机制。     

针对HER2靶点的抗体药物研究与肿瘤靶向治疗

人类表皮生长因子受体2(HER2)属于跨膜酪氨酸激酶受体家族的成员,在肿瘤细胞中存在过表达。研究显示在乳腺癌、卵巢癌、胃癌、肺癌、前列腺癌中均存在不同程度的HER2过表达。抗体靶向治疗与传统化疗相比,特异性强,毒副作用小。本文介绍了曲妥珠单抗和帕妥珠单抗的单药治疗效果和与化疗药物、激素治疗、疫苗的联合治疗效果,以及偶联药物策略,阐述了其他新型抗HER2抗体药物,特别是双特异抗体、免疫毒素以及抗体融合蛋白等研究近况,为相应的HER2抗体药物开发和临床应用提供参考。     

乳腺癌细胞的HER2过表达降低其对紫杉醇的药物敏感性

目的紫杉醇的耐药性由多种因素引起,本文研究乳腺癌细胞中的HER2蛋白水平是否影响细胞对紫杉醇的药物敏感性。方法以HER2低表达的MCF-7/pcDNA3.1细胞和经稳定转染获得的HER2高表达的MCF-7/HER2细胞为研究对象,MTT方法测定紫杉醇对这两种细胞的生长抑制作用,流式细胞仪测定紫杉醇对细胞周期分布的影响,An-nexin V-FITC/PI实验测定紫杉醇诱导的细胞凋亡,两种细胞的裸鼠移植瘤实验测定紫杉醇的抑瘤率。结果紫杉醇对MCF-7/HER2细胞的IC50值是MCF-7/pcDNA3.1细胞的6.2倍;紫杉醇诱导细胞G2/M期阻滞,且是HER2非依赖性的;0.01、0.1和1.0μmol.L-1紫杉醇诱导MCF-7/pcDNA3.1细胞凋亡的百分比分别是15.1%±2.1%、21.0%±2.9%和35.7%±3.8%,诱导MCF-7/HER2细胞凋亡的百分比分别是7.5%±1.7%、14.1%±2.3%和24.2%±3.4%,同一浓度的紫杉醇诱导两细胞的凋亡百分比差异有显著性;5、10和20 mg.kg-1的紫杉醇对裸鼠移植MCF-7/pcDNA3.1肿瘤生长抑制率分别是36.9%、58.7%和75.4%,对裸鼠移植MCF-7/HER2肿瘤生长抑制率分别是20.1%、33.3%和67.3%。在相同剂量下紫杉醇对裸鼠移植的两种肿瘤的抑瘤率差异有显著性。结论HER2蛋白的高表达可降低乳腺癌细胞对紫杉醇的药物敏感性。     

HER2低表达和HER2阴性表达乳腺癌患者临床、病理特征及预后

目的 分析人表皮生长因子受体2(HER2)低表达和HER2阴性表达乳腺癌患者临床、病理特征及预后。方法 行手术切除的非HER2过表达型乳腺癌患者257例中,管腔A型82例,管腔B型118例,三阴性57例。分析非HER2过表达型乳腺癌患者中HER2低表达和HER2阴性表达患者的临床、病理特征及预后。分析管腔A、B型乳腺癌患者和三阴性乳腺癌患者中HER2低表达和HER2阴性表达患者的临床、病理特征及预后。结果 非HER2过表达型乳腺癌患者中,HER2低表达和HER2阴性表达不同年龄、绝经状态、组织学分级、肿瘤浸润淋巴细胞(TILs)百分比、程序性死亡配体1(PD-L1)表达及Ki-67表达的患者比例差异均有统计学意义(P<0.05或P<0.01)。管腔A、B型乳腺癌患者中,HER2低表达和HER2阴性表达患者不同年龄、绝经状态、TILs百分比、PD-L1表达及Ki-67表达的患者比例差异亦有统计学意义(P<0.05或P<0.01)。三阴性乳腺癌患者中,HER2低表达和HER2阴性表达患者不同组织学分级、TILs百分比、PD-L1表达及Ki-67表达的患者比例差异均有...     

力达霉素辅基蛋白与人体乳腺癌结合作用的组织芯片研究

观察力达霉素辅基蛋白LDP与乳腺癌及乳腺正常组织的结合作用,并进一步研究与VEGF和HER2在乳腺癌中表达的相关性。采用免疫组织化学方法和结合组织芯片技术,研究LDP与乳腺癌组织及相应正常乳腺组织的结合;进而在多种病理类型乳腺癌组织芯片上,平行检测VEGF和HER2的表达,并与LDP和乳腺癌组织的结合进行比较,分析相关性。应用免疫细胞化学方法观察LDP与人乳腺癌MCF-7细胞的结合作用。结果显示,在乳腺癌及相应正常乳腺组织芯片上,LDP与乳腺癌组织结合的阳性率为73.2%(30/41),明显高于正常乳腺组织48.3%(15/31),两者有显著差异(χ2=4.63,P<0.05)。在多种病理类型乳腺癌组织芯片上,考察LDP与乳腺癌结合阳性的病例表明,VEGF表达阳性率为88.9%(48/54),两者呈正相关(P<0.001,r=0.389);HER2表达阳性率为84.0%(42/54),两者呈正相关(P<0.01,r=0.287)。激光共聚焦显微镜检测表明,LDP可与人乳腺癌细胞MCF-7结合。上述结果表明,LDP可与乳腺癌组织结合,并与VEGF、HER2在乳腺癌组织中的表达有相关性。LDP与乳腺癌组织结合作用...     

乳腺癌中ApoM差异表达及其对HER2阳性且HR阳性乳腺癌细胞株的生物学影响

目的 探讨载脂蛋白M(ApoM)在乳腺癌中差异表达及其对人表皮生长因子受体2(HER2)阳性且激素受体(HR)阳性的乳腺癌细胞株BT-474和ZR-75-1的生物学影响.方法 检测55例乳腺癌患者癌组织和癌旁组织中ApoM表达水平.应用慢病毒载体构建ApoM过表达体系并转染HER2阳性且HR阳性的乳腺癌细胞株BT-47...     

抗体偶联药物在乳腺癌治疗中的研究进展

抗体偶联药物(ADC)是一类治疗乳腺癌的新型靶向药物,由连接子将化疗药物同单克隆抗体(单抗抗偶联而成,以单抗作为载体将化疗药物靶向运输至目标肿瘤细胞内发挥抗肿瘤作用。根据ADC作用于不同靶点的抗原,分为靶向人表皮生长因子受体2(HER2)、人滋养细胞表面抗原2 (Trop-2)及其他分子等类型。目前,全球范围内已有3种ADC获批治疗乳腺癌,除用于HER2阳性乳腺癌的曲妥珠单抗-美坦新偶联物(T-DM1)、曲妥珠单抗-德鲁替康(T-DXd)外,还有可使三阴性乳腺癌(TNBC)获益的戈沙妥珠单抗(SG)。ADC在HER2阳性乳腺癌治疗中疗效显著,同时在治疗晚期TNBC和部分HER2低表达的乳腺癌中也取得了重要进展,为不同乳腺癌分子分型的人群提供了更多选择。     

ER、PR及HER-2受体在乳腺癌原发灶及复发灶间表达差异及意义

目的:乳腺癌内分泌治疗及免疫靶向药物赫赛汀生物治疗的前提是相应的雌激素受体、孕激素受体的阳性表达及HER-2癌基因蛋白的过表达。目前对复发转移的乳腺癌病例受体表达情况的判断主要依据原发灶,而忽略了原发灶和复发转移灶之间可能存在的差异。本研究着重研究ER、PR及HER-2癌基因蛋白在乳腺癌原发灶及复发转移灶之间的表达差异,探讨其临床意义。方法:采用免疫组织化学检测45例乳腺癌患者原发灶及复发灶中ER、PR及HER2表达,分析研究ER、PR及HER2的变化率。结果:原发灶中ER、PR的阳性率分别为62.2%,60%(28/45,27/45),明显高于复发灶(37.8%17/45,31.1%14/45)(P<0.01)。复发灶中HER-2阳性率为62.2%(28/45),明显高于原发灶(26.7%12/45)(P<0.01)。结论:ER、PR及HER-2癌基因蛋白在乳腺癌原发灶和复发灶之间的表达存在显著性差异,所以在对复发乳腺癌进行临床治疗时,应考虑上述3种指标在复发灶中的确切状况。     

氨氯地平对人乳腺癌细胞MCF-7细胞的抑制作用及机制研究

目的观察氨氯地平对人乳腺癌细胞MCF-7周期、周期蛋白相关基因及产物表达的影响,探讨氨氯地平对人乳腺癌MCF-7细胞周期的影响及其机制。方法MTT检测细胞增殖;流式细胞仪分析细胞周期;RT-PCR技术检测细胞周期相关基因cyclinD1、p21mRNA的表达;Western blot检测细胞周期蛋白cyclinD1、p21的蛋白表达。结果氨氯地平剂量和时间依赖性的抑制人乳腺癌MCF-7细胞增殖,IC50为14.439μmol.L-1。经7.22μmol.L-1(1/2IC50)、14.439μmol.L-1(IC50)、28.88μmol.L-1(2IC50)的氨氯地平作用人乳腺癌MCF-7细胞48h,G0/G1期细胞较对照组明显增高(P<0.05);并使人乳腺癌MCF-7细胞中cyclinD1mRNA及蛋白表达降低;p21mRNA及蛋白表达升高。结论氨氯地平对人乳腺癌MCF-7细胞具有抗增殖作用,并使细胞阻滞于G1期。其G1阻滞机制可能与调控细胞周期相关基因cyclinD1、p21mRNA及蛋白的表达相关。     

HER2阳性乳腺癌的靶向治疗进展

21世纪以来，抗人表皮生长因子受体2(human epidermal growth factor receptor 2,HER2)靶向药物的不断发展，为HER2阳性乳腺癌患者提供更多的治疗选择并显著改善了生存预后。当前抗HER2靶向药物主要包括曲妥珠单抗、帕妥珠单抗等单克隆抗体类药物，拉帕替尼、奈拉替尼等小分子酪氨酸激酶抑制剂，T-DM1、T-DXd等抗体药物偶联物，这些药物在不同病程中扮演着极其重要的角色。HER2阳性乳腺癌的治疗是以曲妥珠单抗的靶向治疗为基础，具有高危因素的早期患者可进行强化靶向治疗进一步改善预后，而晚期患者则需要对靶向治疗方案合理排兵布阵以克服耐药，延长生存。本文将从疾病各个阶段的抗HER2靶向治疗现状、最新研究进展以及对抗HER2靶向治疗未来的展望进行综述。     

Pertuzumab in HER2-positive breast cancer

Abstract

Background:

Lack of response in some patients and relapse during the course of therapy in the treatment of HER2-positive early breast cancer and metastatic breast cancer continue to challenge researchers and clinicians towards a better understanding of the fundamental mechanisms of trastuzumab action and new therapies for HER2. The aim of this review is to discuss current and future treatment options with pertuzumab in the light of new insights into HER2-positive breast cancer.     

Novel Peptidomimetics for Inhibition of HER2:HER3 Heterodimerization in HER2‐Positive Breast Cancer

The current approach to treating HER2‐overexpressed breast cancer is the use of monoclonal antibodies or a combination of antibodies with traditional chemotherapeutic agents or kinase inhibitors. Our approach is to target clinically validated HER2 domain IV with peptidomimetics and inhibit the protein–protein interactions (PPI) of HERs. Unlike antibodies, peptidomimetics have advantages in terms of stability, modification, and molecular size. We have designed peptidomimetics (compounds 5 and 9 ) that bind to HER2 domain IV, inhibit protein–protein interactions, and decrease cell viability in breast cancer cells with HER2 overexpression. We have shown, using enzyme fragment complementation and proximity ligation assays, that peptidomimetics inhibit the PPI of HER2:HER3. Compounds 5 and 9 suppressed the tumor growth in a xenograft mouse model. Furthermore, we have shown that these compounds inhibit PPI of HER2:HER3 and phosphorylation of HER2 as compared to control in tissue samples derived from in vivo studies. The stability of the compounds was also investigated in mouse serum, and the compounds exhibited stability with a half‐life of up to 3 h. These results suggest that the novel peptidomimetics we have developed target the extracellular domain of HER2 protein and inhibit HER2:HER3 interaction, providing a novel method to treat HER2‐positive cancer.     

Peptidomimetic-based antibody surrogate for HER2

Inhibition of human epidermal growth factor receptor 2 mediated cell signaling pathway is an important therapeutic strategy for HER2-positive cancers. Although monoclonal antibodies are currently used as marketed drugs, their large molecular weight, high cost of production and susceptibility to proteolysis could be a hurdle for long-term application. In this study, we reported a strategy for the development of artificial antibody based on γ-AApeptides to target HER2 extracellular domain (ECD). To achieve this, we synthesized a one-bead-two-compound (OBTC) library containing 320,000 cyclic γ-AApeptides, from which we identified a γ-AApeptide, M-3-6, that tightly binds to HER2 selectively. Subsequently, we designed an antibody-like dimer of M-3-6, named M-3-6-D, which showed excellent binding affinity toward HER2 comparable to monoclonal antibodies. Intriguingly, M-3-6-D was completely resistant toward enzymatic degradation. In addition, it could effectively inhibit the phosphorylation of HER2, as well as the downstream signaling pathways of AKT and ERK. Furthermore, M-3-6-D also efficiently inhibited cell proliferation in vitro, and suppressed tumor growth in SKBR3 xenograft model in vivo, implying its therapeutic potential for the treatment of cancers. Its small molecular weight, antibody-like property, resistance to proteolysis, may enable it a new generation of artificial antibody surrogate. Furthermore, our strategy of artificial antibody surrogate based on dimers of cyclic γ-AApeptides could be applied to a myriad of disease-related receptor targets in future.     

Label-free LC-MS analysis of HER2+ breast cancer cell line response to HER2 inhibitor treatment

Background

Human epidermal growth-factor receptor (HER)-2 is overexpressed in 25 % of breast-cancers and is associated with an aggressive form of the disease with significantly shortened disease free and overall survival. In recent years, the use of HER2-targeted therapies, monoclonal-antibodies and small molecule tyrosine-kinase inhibitors has significantly improved the clinical outcome for HER2-positive breast-cancer patients. However, only a fraction of HER2-amplified patients will respond to therapy and the use of these treatments is often limited by tumour drug insensitivity or resistance and drug toxicities. Currently there is no way to identify likely responders or rational combinations with the potential to improve HER2-focussed treatment outcome.

Methods

In order to further understand the molecular mechanisms of treatment-response with HER2-inhibitors, we used a highly-optimised and reproducible quantitative label-free LC-MS strategy to characterize the proteomes of HER2-overexpressing breast-cancer cell-lines (SKBR3, BT474 and HCC1954) in response to drug-treatment with HER2-inhibitors (lapatinib, neratinib or afatinib).

Results

Following 12 hours treatment with different HER2-inhibitors in the BT474 cell-line; compared to the untreated cells, 16 proteins changed significantly in abundance following lapatinib treatment (1 μM), 21 proteins changed significantly following neratinib treatment (150 nM) and 38 proteins changed significantly following afatinib treatment (150 nM). Whereas following 24 hours treatment with neratinib (200 nM) 46 proteins changed significantly in abundance in the HCC1954 cell-line and 23 proteins in the SKBR3 cell-line compared to the untreated cells. Analysing the data we found that, proteins like trifunctional-enzyme subunit-alpha, mitochondrial; heterogeneous nuclear ribonucleoprotein-R and lamina-associated polypeptide 2, isoform alpha were up-regulated whereas heat shock cognate 71 kDa protein was down-regulated in 3 or more comparisons.

Conclusion

This proteomic study highlights several proteins that are closely associated with early HER2-inhibitor response and will provide a valuable resource for further investigation of ways to improve efficacy of breast-cancer treatment.     

Inhibition of mutationally activated HER2

Human epidermal growth factor receptor 2 (HER2) is an oncogenic driver and key therapeutic target for human cancers. Current therapies targeting HER2 are primarily based on overexpression of the wild-type form of HER2. However, kinase domain mutations have been identified that can increase the activity of HER2 even when expressed at basal levels. Using purified enzymes, we confirmed the hyperactivity of two HER2 mutants (D769Y and P780insGSP). To identify small molecule inhibitors against these cancer-associated variants, we used a combined approach consisting of biochemical testing, similarity-based searching, and in silico modeling. These approaches resulted in the identification of a candidate molecule that inhibits mutant forms of HER2 in vitro and in cell-based assays. Our structural model predicts that the compound takes advantage of water-mediated interactions in the HER2 kinase binding pocket.     

Perspectives of HER2-targeting in gastric and esophageal cancer

Introduction: The blockade of HER2 signaling has significantly improved the outlook for esophagogastric cancer patients. However, targeting HER2 still remains challenging due to complex biology of this receptor in gastric and esophageal cancers.

Areas covered: Here, we review complex HER2 biology, current methods of HER2 testing and tumor heterogeneity of gastroesophageal cancer. Ongoing and completed clinical research data are discussed.

Expert opinion: HER2 overexpression is a validated target in gastroesophageal cancer, with therapeutic implications resulting in prolonged survival when inhibited in the front-line setting. With standardized HER2 testing in gastro-esophageal cancer, the ongoing trials are testing newer agents and combinations including combination of anti-HER2 antibodies with immunotherapy. Clonal heterogeneity and emergence of resistance will challenge our approach to treating these patients beyond the frontline settings.     

HER2在膀胱肿瘤中的表达及其单抗诱导膀胱肿瘤细胞凋亡

目的为探讨膀胱肿瘤的HER2表达阳性率及其与肿瘤分级的关系,以及抗HER2单克隆抗体对HER2表达阳性细胞株的增殖影响。方法用免疫组织化学法检测43例膀胱肿瘤标本和肿瘤细胞株的HER2表达量,用不同浓度的抗HER2单抗和阿霉素作用于HER2表达阳性和阴性的细胞株,MTT法检测细胞抑制率,流式细胞仪检测抗HER2单抗作用后肿瘤细胞的凋亡率。结果43例膀胱移行细胞癌标本中,I级12例,HER2高表达者0例;II级14例,HER2高表达者2例（14％）;III级17例,HER2高表达者13例（76％）。T24细胞株HER2高表达,BIU87阴性。抗HER2单抗对HER2表达阳性的细胞株增殖抑制呈剂量和时间依赖性,并能诱导HER2表达阳性的肿瘤细胞凋亡,但对HER2表达阴性的细胞株无明显作用,P〈0．05／P〈0．01。阿霉素对四株细胞均有细胞毒作用,P〉0．05。结论分化较差的移行细胞癌HER2阳性率高,抗HER2单抗能够选择性诱导HER2高表达的膀胱肿瘤细胞株凋亡。     

Cardiotoxicity of novel HER2-targeted therapies

Abstract

Background:

Trastuzumab, an anti-HER2 humanized monoclonal antibody, is the standard treatment for both early and metastatic HER2-positive breast cancer. In addition to other chemotherapeutic agents, trastuzumab significantly improves response rate and survival in HER2-positive early and metastatic breast cancer. Although it is well known that trastuzumab therapy is closely associated with both symptomatic and asymptomatic cardiotoxicity, less is known about novel HER2-targeted therapies. The aim of this review is to discuss the cardiac safety data from recent studies of novel anti-HER2 drugs other than trastuzumab.     

Intracellular sequestration of HER2 via targeted subcellular peptide delivery

The use of peptides in drug development has been hampered by their poor pharmaceutical properties, most notably their inability to reliably permeate biological membranes and lack of targeting. To overcome these disadvantages, the AMino acid Intracellular Delivery SysTem (AMIDST) was developed. This modular peptide-based delivery system confers cellular permeability and organelle-specific targeting for therapeutic peptides. As demonstrated in this study, the delivery of a HER2-binding peptide to the secretory organelles of breast cancer cells resulted in intracellular sequestration, a reduction in downstream signalling, and reduced viability compared to the delivery of a control peptide. Given its modular design and ease of production, AMIDST has the potential to enhance the use of peptides as therapeutic agents.     

HER2在子宫内膜癌中的表达及临床意义

目的 探讨HER2在子宫内膜癌中表达及其与肿瘤FIGO分期、病理分级、浸润深度、淋巴结转移的关系。方法 子宫内膜癌46例、不典型增生10例、子宫内膜增生过长10例、正常子宫内膜20例,应用免疫组织化学方法 对HER2的表达情况进行分析。结果 HER2在癌组织中的表达明显高于非癌组织,差异有显著性（P〈0.05）;HER2在癌组织中的表达与肿瘤的FIGO分期、病理分级、浸润深度、淋巴结转移有关。结论 HER2在子宫内膜癌中的表达与内膜癌的生物学行为有关,可作为子宫内膜癌预后的指标,指导子宫内膜癌术后的治疗。