5，8-二代喹唑啉类化合物LJK-11对HER2高表达肿瘤细胞的作用和分子机制初探

目的 观察LJK-11对HER2高表达细胞的作用。方法 检测LJK-11对不同肿瘤细胞作用的剂量效应；用Western blot检测药物引起的细胞内酪氨酸激酶信号表达变化。结果 随着药物浓度的增加，UK-11对肿瘤细胞的增殖抑制作用逐渐明显，并能够引起肿瘤细胞的凋亡；westemblot检测显示受体酪氨酸激酶HER2磷酸化表达降低。结论 LJK-11可能是一种新型的酪氨酸激酶抑制剂，这一作用机制将为研制出新型的抗肿瘤药提供理论依据。     

人源化抗HER2单克隆抗体Pertuzumab

人表皮生长因子受体2（HER2）为受体酪氨酸激酶家族成员,是多种肿瘤细胞的重要生长调节因子,其过度表达对肿瘤的发生和恶性转化有促进作用,而HER2单体无活性,必须经配体结合后与自身或HER家族其他成员形成二聚体才能被激活。因此,HER2已成为肿瘤治疗研究中的一个潜在有效的靶标。目前临床上开发使用的HER2特异性靶向药物主要有两类,即人源化抗体和小分子酪氨酸激酶抑制剂。     

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。     

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。     

一种新的吲哚咔唑类化合物(ZWM233)的体外抗肿瘤作用及机制探讨

目的探讨ZWM233体外对多种肿瘤细胞株的增殖抑制及对K562细胞的凋亡诱导作用。方法采用MTT法检测ZWM233对K562、HL-60、A549、HeLa及HCT-116等10种肿瘤细胞株的增殖抑制作用;流式细胞仪检测对K562细胞周期的影响;AnnexinV/PI双染法考察对K562细胞的凋亡诱导作用;Western blot检测K562细胞中凋亡相关蛋白bax、bcl-2、Caspase-3、Caspase-9及PARP的变化,同时检测蛋白激酶C(PKC)各亚型、GSK-3β、ERK1/2、JNK及其磷酸化水平的变化。结果 ZWM233体外能有效抑制多种肿瘤细胞株的增殖,其中对K562细胞作用明显,IC50为2.81μmol.L-1;流式细胞仪检测K562细胞被明显阻滞在G2/M期,并诱导其凋亡;Western blot结果显示ZWM233作用K562细胞24 h后,可明显下调抗凋亡蛋白bcl-2的表达,引起Caspase-9、Caspase-3及下游底物PARP的剪切,诱导K562细胞凋亡。Western blot检测结果进一步显示药物作用24 h后PKCδ的表达有所降低,其下游分子p-GSK-3β及p-ERK的表达水平降低,而p-JNK蛋白的表达水平升高。结论ZWM233体外能有效抑制K562细胞生长,并通过激活线粒体途径诱导其凋亡,其机制可能是通过下调PKCδ,进一步抑制p-GSK-3β及p-ERK1/2的表达来发挥凋亡诱导作用。     

靶向酪氨酸激酶治疗癌症

抑制病理酪氨酸激酶作用的分子靶向药物应用于临床,是近年来癌症研究领域里最令人振奋的进展之一。过去10年的临床研究已证实酪氨酸激酶抑制剂对癌症患者安全有效,其中的一些已成为特定类型肿瘤的标准治疗药物,例如针对BCR-ABL和其他激酶的伊马替尼(imatinib)、针对HER2/ErB2受     

七叶皂苷体外抗SGC-7901细胞的作用及机制研究

目的研究七叶皂苷体外抗SGC-7901肿瘤细胞的作用及其机制。方法采用MTT法观察药物对SGC-7901肿瘤细胞的增殖抑制作用;采用流式细胞仪检测SGC-7901肿瘤细胞周期的变化;FITC-AnnexinⅤ/PI双标记检测SGC-7901肿瘤细胞的凋亡;Western blot检测凋亡相关蛋白Bcl-2的表达。结果七叶皂苷可明显抑制SGC-7901肿瘤细胞的增殖,并抑制细胞周期和诱导细胞发生凋亡,可下调凋亡相关蛋白Bcl-2的表达。结论七叶皂苷体外对SGC-7901肿瘤细胞具有良好的抑制作用,并可诱导细胞发生凋亡。     

HER2基因突变晚期非小细胞肺癌治疗进展

肺癌是全球范围内一种高发病率和高死亡率的恶性肿瘤,非小细胞肺癌（NSCLC）是最常见的亚型,发生率约85%。人表皮生长因子受体2（HER2）是受体酪氨酸激酶（RTK）的重要成员之一,NSCLC中HER2基因主要表现为HER2突变、HER2扩增和HER2过表达三种形式。目前,靶向HER2突变的酪氨酸激酶抑制剂、单克隆抗体和抗体偶联药物在HER2突变的NSCLC中显示出一定的临床疗效,但相关免疫治疗疗效有限。本文就HER2突变相关NSCLC的治疗进展进行综述,以期为进一步完善HER2突变晚期NSCLC临床诊疗策略提供理论依据。     

靶向HER3的治疗性单克隆抗体研究进展

 人表皮生长因子受体3 (human epidermal growth factor receptor 3,HER3) 是I型跨膜酪氨酸激酶受体,在多种肿瘤中表达上调。此文就HER3的结构特征、HER3与肿瘤的关系以及抗HER3抗体的抗肿瘤作用进行简要综述。     

3-取代芳基氧化吲哚(PH II-7)对肿瘤细胞周期的影响

目的观察3-取代芳基氧化吲哚(PH II-7)对肿瘤细胞周期分布的影响，明确PH II-7的抗敏感肿瘤和耐药肿瘤的共同机制。方法用流式细胞仪检测细胞周期分布，Western印迹分析细胞周期相关蛋白的表达，³H-TdR参入法检测细胞DNA合成，ELISA测定酪氨酸激酶的活性。结果PH II-7对多种肿瘤细胞（包括耐药细胞）的周期分布均有影响，阻滞细胞G₁期至S期的移行，细胞周期相关蛋白CDK2，Rb和c-myc的表达被抑制，Cyclin E的表达升高。PH II-7还可抑制³H-TdR的参入，抑制EGFR的酪氨酸激酶的活性。结论抗耐药肿瘤新药PH II-7是一种细胞周期阻滞剂，可能是通过抑制CDK2而使肿瘤细胞阻滞在G₁期，同时也说明细胞周期阻滞可能是抗耐药肿瘤的新方向。     

Foretinib (GSK1363089), a multi-kinase inhibitor of MET and VEGFRs, inhibits growth of gastric cancer cell lines by blocking inter-receptor tyrosine kinase networks

To explore the mechanism of action of foretinib (GSK1363089), an oral multi-kinase inhibitor known to target MET, RON, AXL, and vascular endothelial growth factor receptors (VEGFRs), in gastric cancer, we evaluated the effects of the agent on cell growth and cell signaling in the following panel of gastric cancer cell lines: KATO-III, MKN-1, MKN-7, MKN-45, and MKN-74. Of these, only MKN-45 and KATO-III, which harbor MET and fibroblast growth factor receptor 2 (FGFR2) amplification, respectively, were highly sensitive to foretinib. In MKN-45, 1 μM of foretinib or PHA665752, another MET kinase inhibitor, inhibited phosphorylation of MET and downstream signaling molecules as expected. In KATO-III, however, PHA665752 inhibited phosphorylation of MET independently of downstream molecules. Further, 1 μM of foretinib or PD173074, a selective FGFR kinase inhibitor, inhibited phosphorylation of FGFR2 and downstream molecules, suggesting that foretinib targets FGFR2 in KATO-III. We confirmed this novel activity of foretinib against FGFR2 in OCUM-2M, another FGFR2-amplified gastric cancer cell line. Using a phospho-receptor tyrosine kinase array, we found that foretinib inhibits phosphorylation of epidermal growth factor receptor (EGFR), HER3 and FGFR3 via MET inhibition in MKN-45, and EGFR, HER3 and MET via FGFR2 inhibition in KATO-III. Knockdown of HER3 and FGFR3 in MKN-45 with siRNA resulted in the partial inhibition of cell signaling and cell growth. In conclusion, foretinib appears effective against gastric cancer cells harboring not only MET but also FGFR2 amplification, and exerts its inhibitory effects by blocking inter-RTK signaling networks with MET or FGFR2 at their core.     

Growth differentiation factor 15 (GDF15)-mediated HER2 phosphorylation reduces trastuzumab sensitivity of HER2-overexpressing breast cancer cells

Resistance to the anti-HER2 monoclonal antibody trastuzumab is a major problem in the treatment of HER2-overexpressing metastatic breast cancer. Growth differentiation factor 15 (GDF15), which is structurally similar to TGF beta, has been reported to stimulate phosphorylation of HER2. We tested the hypothesis that GDF15-mediated phosphorylation of HER2 reduces the sensitivity of HER2-overexpressing breast cancer cell lines to trastuzumab. Gene microarray analysis, real-time PCR, and ELISA were used to assess GDF15 expression. Growth inhibition and proliferation assays in response to pharmacologic inhibitors of HER2, TGF beta receptor, or Src were performed on cells stimulated with recombinant human GDF15 or stable GDF15 transfectants. Western blotting was performed to determine effects of GDF15 on HER2 signaling. Cells were infected with lentiviral GDF15 shRNA plasmid to determine effects of GDF15 knockdown on cell survival in response to trastuzumab. Cells with acquired or primary trastuzumab resistance showed increased GDF15 expression. Exposure of trastuzumab-sensitive cells to recombinant human GDF15 or stable transfection of a GDF15 expression plasmid inhibited trastuzumab-mediated growth inhibition. HER2 tyrosine kinase inhibition abrogated GDF15-mediated Akt and Erk1/2 phosphorylation and blocked GDF15-mediated trastuzumab resistance. Pharmacologic inhibition of TGF beta receptor blocked GDF15-mediated phosphorylation of Src. Further, TGF beta receptor inhibition or Src inhibition blocked GDF15-mediated trastuzumab resistance. Finally, lentiviral GDF15 shRNA increased trastuzumab sensitivity in cells with acquired or primary trastuzumab resistance. These results support GDF15-mediated activation of TGF beta receptor-Src-HER2 signaling crosstalk as a novel mechanism of trastuzumab resistance.     

11,11'-dideoxy-verticillin: a natural compound possessing growth factor receptor tyrosine kinase-inhibitory effect with anti-tumor activity

11,11'-dideoxy-verticillin, a compound of the novel epidithiodioxopiprazine structural class, is isolated from the traditional Chinese medicinal herb Shiraia bambusicola. The present study demonstrated for the first time that 11,11'-dideoxy-verticillin has potent tyrosine kinase-inhibitory and anti-tumor activities. In the cell-free ELISA tyrosine kinase assay, 11,11'-dideoxy-verticillin significantly inhibited the activities of epidermal growth factor receptor (EGFR), vascular endothelial growth factor receptor-1/fms-like tyrosine kinase-1 (VEGFR-1/Flt-1) and human epidermal growth factor receptor-2 (HER2/ErbB-2), with relative specificity on EGFR and VEGFR-1 with IC50s of 0.136+/-0.109 and 1.645+/-0.885 nM, respectively. Exposure of 11,11'-dideoxy-verticillin for 1 h to EGFR-overexpressed MDA-MB-468 human breast carcinoma cells and HER2-overexpressed SK-OV-3 human ovarian adenocarcinoma cells resulted in obvious inhibition of EGF-induced phosphorylation of EGFR and HER2. In addition, 11,11'-dideoxy-verticillin also inhibited the EGF-induced phosphorylation of Erk1/2, but had no effect on the phosphorylation of AKT in both tumor cell lines. Moreover, 11,11'-dideoxy-verticillin has potent anti-tumor activity. In vitro cytotoxicity assay showed that 11,11'-dideoxy-verticillin potently inhibited the proliferation of four human breast tumor cell lines with an average IC50 value of 0.2 microM. In vivo, 11,11'-dideoxy-verticillin exhibited remarkable efficacy against mice sarcoma 180 and hepatoma 22 after daily i.p. administration of 0.5 or 0.75 mg/kg with inhibition rates ranging from 45.0 to 72.4%. Treated with 11,11'-dideoxy-verticillin at 0.5-2.0 microM for 36 h, MB-MB-468 cells exhibited significant apoptotic morphological changes. At low concentrations (0.0625-0.5 microM) for 24 h, 11,11'-dideoxy-verticillin induced a dose-dependent accumulation of MDA-MB-468 cells in the G2/M phase of the cell cycle. These results indicate that 11,11'-dideoxy-verticillin is a naturally derived growth factor receptor tyrosine kinase inhibitor with potent anti-tumor activity.     

表没食子儿茶素没食子酸酯联合曲妥珠单抗对HER2过表达乳腺癌细胞增殖的影响及其机制

目的 研究表没食子儿茶素没食子酸酯(EGCG)联合曲妥珠单抗对人表皮生长因子受体2(HER2)过表达乳腺癌细胞增殖的影响及其作用机制.方法 表达纯化曲妥珠单抗;用CCK-8细胞增殖检测试剂盒(CCK8)检测不同浓度EGCG、曲妥珠单抗及两药联用对HER2过表达乳腺癌细胞BT474、SK-BR-3的增殖抑制作用;用Wes...     

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。     

Receptor tyrosine kinases and anticancer therapy

Receptor and non-receptor protein tyrosine kinases (PTKs) are essential enzymes in cellular signaling processes and signal transduction pathways that regulate cell growth, differentiation, migration and metabolism by catalyzing protein phosphorylation and dephosphorylation. In recent years, different tyrosine kinase receptors were identified as regulators of tumor or tumor vessel growth. Their inhibition by specific tyrosine kinase inhibitors and antibodies targeting growth factors and their receptors were recently shown to constitute a new modality for treating cancers. The pathognomonic role of the inhibited tyrosine kinase defines the way of action, whereas the amount of expression in tumor tissue is thought to define the indication for the tumor entity. Various compounds targeting PTKs are under clinical investigation in phase I-III trials or are already approved. This review describes new drugs targeting BCR-Abl, c-kit, EGFR (epidermal growth factor receptor), tumor angiogenesis via VEGF (vascular endothelial growth factor), HER2/neu and "multitarget" tyrosine kinase inhibitors.     

非诺贝特抑制人胃癌MGC 803细胞增殖及机制

目的: 探讨非诺贝特对胃癌MGC 803细胞生物活性的影响及作用机制。方法: 采用MTT法检测非诺贝特对胃癌MGC 803细胞的增殖抑制作用;采用流式细胞术观察非诺贝特对MGC 803细胞周期和凋亡的影响;免疫荧光染色检测非诺贝特对MGC 803细胞Bcl-2/Bax蛋白表达及细胞生长的抑制作用;蛋白免疫印迹法(Western Blotting)检测非诺贝特对MGC 803细胞p-ERK1/2、p-AKT、ERK1/2 和AKT蛋白表达的影响。结果: 非诺贝特对MGC 803细胞增殖抑制作用具有时间和剂量依赖性。非诺贝特使MGC 803细胞的周期阻滞于G2/M期,并诱导其凋亡,Bcl-2表达逐渐减少,Bax表达逐渐增加,且下调 ERK1/2和AKT蛋白的磷酸化水平,但对ERK1/2 和AKT蛋白表达水平没有影响。结论: 非诺贝特能够抑制胃癌MGC 803细胞增殖,并诱导其凋亡。其分子机制可能包括下调ERK1/2和AKT蛋白的磷酸化水平。     

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.     

Ganoderic acids suppress growth and angiogenesis by modulating the NF-kappaB signaling pathway in breast cancer cells

It has been demonstrated that ganoderma acids suppress growth, angiogenesis and invasiveness of highly invasive and metastatic breast cancer cells in vitro and vivo. However, the mechanism of action of ganoderma acids in breast cancer remains unknown. In the present study, we looked into the effect of ganoderic acid Me (GA-Me) on cellular phenotypes and tumor growth in the MDA-MB-231 breast cancer cell line. The results indicated the GA-Me inhibited nuclear factor kappaB (NF-κB) activity at 24 h in MDA-MB-231 cells. When MDAMB- 231 cells were stimulated with tumor necrosis factor-alpha (TNF-α), the inhibitory effects of GA-Me were still maintained. We demonstrated that GA-Me inhibited proliferation and invasion and induced apoptosis in MDA-MB-231 cells via suppressing the NF-κB activity. However, GA-Me did not inhibit the phosphorylation and degradation of IkappaB-α (IkB-α). GA-Me down-regulated the expression of various NF-κB-regulated genes including genes involved in cell proliferation (c-Myc and cyclin D1), anti-apoptosis (Bcl-2), invasion (MMP-9) and angiogenesis (VEGF, interleukin (IL)-6 and -8). I.P. administration of GA-Me inhibited tumor growth of MDA-MB-231 cells in vivo. Our results demonstrated that GA-Me inhibited proliferation, angiogenesis, invasion and induced apoptosis in MDA-MB-231 cells via suppressing NF-κB activity and the expression profile of its downstream genes. These findings provide evidence for a novel role of GA-Me in the prevention and treatment of breast cancer by its ability to modulate the NF-κB signaling pathway.