乳腺癌患者血清HER-2／neu浓度及临床意义的分析

目的分析乳腺癌患者血清人表皮生长因子受体．2（HER-2／neu）的水平与组织HER-2表达水平的差异,分析血清HER-2／neul的影响因素以及与化疗疗效的相关性。方法采用酶联免疫吸附（ELISA）方法检测37例可手术的早期乳腺癌患者及74例晚期转移性乳腺癌患者血清HER-2／neu的水平,分析血清HER-2／neu与组织中HER-2的表达、临床参数的相关性。结果晚期乳腺癌患者血清HER-2／neu的水平与组织HER-2的状态一致性较好（P〈0．05）,早期乳腺癌患者中两者则无明显关系。乳腺癌血清HER-2的水平与血清CA153、CEA均无明显相关性。晚期乳腺癌血清HER-2的水平与肿瘤大小、远处转移数目、脉管瘤栓具有明显关系,而与月经状况、ER、PR均无明显关系（P〉0．05）。血清HER-2水平的变化与化疔疗效有关（P〈0．05）。结论晚期乳腺癌患者血清HER-2／neu水平与肿瘤组织中HER-2表达是一致的且与肿瘤负荷密切相关,可作为组织学检测的重要补充方法。     

Activity of lapatinib is independent of EGFR expression level in HER2-overexpressing breast cancer cells

Epidermal growth factor receptor (EGFR/ErbB1) and HER2 (ErbB2/neu), members of the ErbB receptor tyrosine kinase family, are frequently overexpressed in breast cancer and are known to drive tumor growth and progression, making them promising targets for cancer therapy. Lapatinib is a selective competitive inhibitor of both the HER2 and EGFR tyrosine kinases. Although lapatinib showed significant activity in patients with HER2-positive breast cancer, the role of EGFR in the response of breast cancer to lapatinib has not been defined. Here, we examined the role of EGFR expression levels in the sensitivity of HER2-overexpressing breast cancer cells to lapatinib. Depletion of EGFR by EGFR small-interfering RNA knockdown did not affect lapatinib sensitivity in these cells, whereas treated HER2 siRNA knockdown cells became more resistant to lapatinib. We conclude that the in vitro activity of lapatinib is not dependent on EGFR expression level in HER2-overexpressing breast cancer cells.     

A genomic approach to identify molecular pathways associated with chemotherapy resistance

Resistance to chemotherapy in cancer is common. As gene expression profiling has been shown to anticipate chemotherapeutic resistance, we sought to identify cellular pathways associated with resistance to facilitate effective combination therapy. Gene set enrichment analysis was used to associate pathways with resistance in two data sets: the NCI-60 cancer cell lines deemed sensitive and resistant to specific chemotherapeutic agents (Adriamycin, cyclophosphamide, docetaxel, etoposide, 5-fluorouracil, paclitaxel, and topotecan) and a series of 40 lung cancer cell lines for which sensitivity to cisplatin and docetaxel was determined. Candidate pathways were further screened in silico using the Connectivity Map. The lead candidate pathway was functionally validated in vitro. Gene set enrichment analysis associated the matrix metalloproteinase, p53, methionine metabolism, and free pathways with cytotoxic resistance in the NCI-60 cell lines across multiple agents, but no gene set was common to all drugs. Analysis of the lung cancer cell lines identified the bcl-2 pathway to be associated with cisplatin resistance and the AKT pathway enriched in cisplatin- and docetaxel-resistant cell lines. Results from Connectivity Map supported an association between phosphatidylinositol 3-kinase/AKT and docetaxel resistance but did not support the association with cisplatin. Targeted inhibition of the phosphatidylinositol 3-kinase/AKT pathway with LY294002, in combination with docetaxel, resulted in a synergistic effect in previously docetaxel-resistant cell lines but not with cisplatin. These results support the use of a genomic approach to identify drug-specific targets associated with the development of chemotherapy resistance and underscore the importance of disease context in identifying these pathways.     

Hunk is required for HER2/neu-induced mammary tumorigenesis

Understanding the molecular pathways that contribute to the aggressive behavior of human cancers is a critical research priority. The SNF1/AMPK-related protein kinase Hunk is overexpressed in aggressive subsets of human breast, ovarian, and colon cancers. Analysis of Hunk(–/–) mice revealed that this kinase is required for metastasis of c-myc–induced mammary tumors but not c-myc–induced primary tumor formation. Similar to c-myc, amplification of the proto-oncogene HER2/neu occurs in 10%–30% of breast cancers and is associated with aggressive tumor behavior. By crossing Hunk(–/–) mice with transgenic mouse models for HER2/neu-induced mammary tumorigenesis, we report that Hunk is required for primary tumor formation induced by HER2/neu. Knockdown and reconstitution experiments in mouse and human breast cancer cell lines demonstrated that Hunk is required for maintenance of the tumorigenic phenotype in HER2/neu-transformed cells. This requirement is kinase dependent and resulted from the ability of Hunk to suppress apoptosis in association with downregulation of the tumor suppressor p27(kip1). Additionally, we find that Hunk is rapidly upregulated following HER2/neu activation in vivo and in vitro. These findings provide what we believe is the first evidence for a role for Hunk in primary tumorigenesis and cell survival and identify this kinase as an essential effector of the HER2/neu oncogenic pathway.     

Prognostic markers in breast cancer: the reliability of HER2/neu status in core needle biopsy of 325 patients with primary breast cancer

INTRODUCTION: The assessment of HER2/neu overexpression in tissue provides information about one of the most relevant prognostic and predictive markers in breast cancer: overexpression of HER2/neu is associated with worse prognosis in primary breast cancer. Since core needle biopsy is increasingly used for the diagnosis of breast cancer, the purpose of this study was to assess the reliability of HER2/neu evaluation using this technique in patients with primary breast cancer. PATIENTS AND METHODS: We investigated the accuracy of immunohistochemical assessment of HER2/neu in core needle biopsies compared with surgically obtained specimens in 325 patients with primary breast cancer. In patients strongly positive for HER2/neu, additional fluorescence in situ hybridization (FISH) analysis of needle biopsies was performed. RESULTS: Using immunohistochemistry alone, accuracy of HER2/neu assessment in core biopsies in relation to surgically removed specimens was 92% and increased to 96% with additional FISH analysis (weighted Kappa coefficient: 0.86). DISCUSSION: As proven with this large series of patients, the assessment of HER2/neu status by core needle biopsy in breast cancer is accurate. Notwithstanding, in order to minimize the number of false-positive results, strongly positive core needle biopsies identified using immunohistochemistry should be confirmed by FISH analysis.     

不同分子分型乳腺癌新辅助化疗后缓解率的差异性研究

目的 探讨新辅助化疗对不同分子分型乳腺癌的疗效.方法 选取本院2007年6月-2014年6月本院收治的122例乳腺癌患者,明确其肿瘤分期,免疫组织化学技术明确ER、PR、HER2及Ki-67表达状况,并分为腺腔A型（Luminal A）、腺腔B型（LuminalB）、HER2型、基底细胞型（Basal-like）,采用阿霉素联合多西紫杉醇类方案（ET方案）对所有患者进行2周期的新辅助化疗,判断肿瘤治疗效果及患者毒副反应发生情况.结果 新辅助化疗后总有效人数为40例,占总人数的32.79％,其中Lurninal A型总有效率为9.10％ （3/33）,Luminal B型总有效率为12.9％（4/31）,HER2型总有效率为53.8％（14/26）,Basal-like型总有效率为59.4％（19/32）.腺腔A型与腺腔B型的总有效率差异无统计学意义（P＞0.05）,HER2型与基底细胞型总有效率差异无统计学意义（P＞0.05）,而HER2型与基底细胞型的总有效率均高于腺腔A型与腺腔B型,差异有统计学意义（P＜0.05）.不同分子分型乳腺癌患者化疗中均出现不同程度的化疗副反应,未出现导致化疗中断的副反应.结论 不同分子分型的乳腺癌患者采用ET方案新辅助化疗的疗效不同,乳腺癌分子分型可能是乳腺癌治疗具有价值的依据之一,较Luminal而言,HER2型与Basal-like型患者的总有效率更高.     

Use of anti-CD3 x anti-HER2/neu bispecific antibody for redirecting cytotoxicity of activated T cells toward HER2/neu+ tumors

Relapse after adjuvant chemotherapy or high-dose chemotherapy with stem cell transplant for high-risk breast cancer remains high and new strategies that provide additional antitumor effects are needed. This report describes methods to generate highly effective HER2/neu-specific cytotoxic T cells by arming activated T cells with anti-CD3 x anti-HER2/neu bispecific antibody (BsAb). OKT3 and 9184 (anti-HER2) monoclonal antibodies (mAb) were conjugated and used to arm T cells that were subsequently tested in binding, cytotoxicity, and cytokine secretion assays. Armed T cells aggregated and specifically killed HER2/neu(+) breast cancer cells. Cytotoxicity emerged after 6 days of culture, was higher in armed T cells than unarmed T cells at all effector to target ratios (E/T) tested, and increased as the arming dose was increased. At an E/T of 20:1, the mean cytotoxicity of armed activated T cells (ATC) from 10 normal subjects increased by 59 +/- 11% (+/-SD) over that seen in unarmed ATC (p < 0.001) and the mean cytotoxicity of armed ATC from 6 cancer patients increased by 32 +/- 9% above that seen for unarmed ATC (p < 0.0004). After arming, the BsAb persisted on ATC up to 72 h and armed ATC continued to be cytotoxic up to 54 h. The amount of interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), and granulocyte-macrophage colony-stimulating factor (GM-CSF) secreted was 1699, 922, and 3092 pg/ml/10(6) cells per 24 h, respectively, when armed T cells were exposed to a HER2/neu(+) breast carcinoma cell line. These studies show the feasibility and clinical adaptability of this approach for generating large numbers of anti-HER2-specific, cytotoxic T cells for clinical trials.     

The clinical significance between activation of nuclear factor kappa B transcription factor and overexpression of HER-2/neu oncoprotein in Taiwanese patients with breast cancer

BACKGROUND: This study investigated the role of nuclear factor-kappa B (NF-kappaB) activity in human breast cancer with overexpression of HER-2/neu oncoprotein, as well as its role on expression of different histological grades of cancer cells taken from Taiwanese breast cancer patients. MATERIALS AND METHODS: Specimens were collected from 82 female breast cancer patients. The HER-2/neu oncoprotein was measured by immunohistochemistry. NF-kappaB activity expression was assessed by the electrophoretic mobility shift assay, and confirmed by the supershift technique using anti-P65 antibody in both breast cancer tissue and the adjacent normal tissue. The histological grades were measured by Modified Bloom-Richardson Grading Scheme. RESULTS: Of the 82 cancer specimens, 81 (98.7%) showed higher or equal expressions of NF-kappaB activity when compared to the adjacent normal tissue. Fifty-five cases (67.1%) had higher levels of NF-kappaB activity in the cancerous tissue than in the adjacent normal tissue (p<0.005). With regard to tumor size, steroid receptors, stages, histological types, and node status, there were no statistically significant differences in NF-kappaB activity between cancerous tissues and adjacent normal tissues. However, significantly higher expressions of NF-kappaB activity were seen in those cases with positive HER2/neu oncoprotein, poorly differentiated histological grades, high nuclear pleomorphisms, and high mitotic counts (p<0.05). Positive HER-2/neu overexpression of oncoprotein had higher NF-kappaB activity (86%) than negative overexpression (60%) (p<0.05). It has been shown that the NF-kappaB activity increases in the HER-2/neu oncoprotein overexpression in human breast cancer. CONCLUSION: Overexpression of HER-2/neu gene could induce NF-kappaB activity in human breast cancer cells, as has been confirmed in other research on cell lines.     

染料木素抑制HER2阳性人乳腺癌与卵巢癌细胞增殖作用的研究

目的研究染料木素对人HER2高表达乳腺癌与卵巢癌细胞增殖的抑制作用,并探讨其作用机制。方法采用流式细胞分析技术、western blotting及细胞增殖与凋亡检测试剂盒等检测方法,对染料木素作用于HER2表达阴性的MCF-7细胞与通过稳定转染HER2而获得的MCF-7-1以及BT-474、SKOV-3等HER2阳性表达细胞的效果进行了剂量或时间反应关系的研究。结果浓度为0.1～10μg/ml的染料木素对HER2表达水平低的MCF-7细胞增殖的影响不大,而对HER2高表达的MCF-7-1、BT-474和SKOV-3细胞的增殖有显著的抑制作用(与DMSO对照组相比,P<0.01),且表现出剂量依赖性反应关系。用10μg/ml的染料木素作用12～48 h可以诱导BT-474细胞凋亡或坏死(与DMSO对照组相比,P<0.01),且表现出时间依赖性反应关系。结论染料木素能够明显抑制HER2阳性肿瘤细胞的增殖,这一作用可能是通过下调肿瘤细胞HER2信号转导而介导的。     

Safety and efficacy of the combination of trastuzumab with docetaxel for HER2-positive women with advanced breast cancer. A review of the existing clinical trials and results of the expanded access programme in the UK

Trastuzumab is a humanised monoclonal antibody against the extracellular domain of HER2 (human epidermal growth factor receptor-2) that is overexpressed in about 25% of human breast cancers. It has shown clinical benefit in HER2-positive breast cancer cases when used alone or in combination with chemotherapy. Trastuzumab increases the response rate to chemotherapy and prolongs survival when used in combination with taxanes. In this article, we review the clinical trials where trastuzumab has been administered together with docetaxel, and we present the results of the trastuzumab expanded access programme (EAP) in the UK. Combination of trastuzumab with docetaxel results in similar response rates and time-to-progression with the trastuzumab/paclitaxel combinations. The toxicity of the combination and the risk of heart failure are low. The clinical data for the docetaxel/trastuzumab combination indicate a favourable profile from both the efficacy and the safety point of view and confirm the feasibility and safety of trastuzumab administration both as monotherapy and in combination with docetaxel.     

Dacomitinib (PF-00299804), an Irreversible Pan-HER Inhibitor, Inhibits Proliferation of HER2-Amplified Breast Cancer Cell Lines Resistant to Trastuzumab and Lapatinib

The human EGF (HER) family of receptors has been pursued as therapeutic targets in breast cancer and other malignancies. Trastuzumab and lapatinib are standard treatments for HER2-amplified breast cancer, but a significant number of patients do not respond or develop resistance to these drugs. Here we evaluate the in vitro activity of dacomitinib (PF-00299804), an irreversible small molecule pan-HER inhibitor, in a large panel of human breast cancer cell lines with variable expression of the HER family receptors and ligands, and with variable sensitivity to trastuzumab and lapatinib. Forty-seven human breast cancer and immortalized breast epithelial lines representing the known molecular subgroups of breast cancer were treated with dacomitinib to determine IC(50) values. HER2-amplified lines were far more likely to respond to dacomitinib than nonamplified lines (RR, 3.39; P < 0.0001). Furthermore, HER2 mRNA and protein expression were quantitatively associated with response. Dacomitinib reduced the phosphorylation of HER2, EGFR, HER4, AKT, and ERK in the majority of sensitive lines. Dacomitinib exerted its antiproliferative effect through a combined G(0)-G(1) arrest and an induction of apoptosis. Dacomitinib inhibited growth in several HER2-amplified lines with de novo and acquired resistance to trastuzumab. Dacomitinib maintained a high activity in lines with acquired resistance to lapatinib. This study identifies HER2-amplified breast cancer lines as most sensitive to the antiproliferative effect of dacomitinib and provides a strong rationale for its clinical testing in HER2-amplified breast cancers resistant to trastuzumab and lapatinib. Mol Cancer Ther; 11(9); 1978-87. ?2012 AACR.     

HER2/neu expression in bladder cancer: relationship to cell cycle kinetics

BACKGROUND AND OBJECTIVES: The incidence of overexpression of HER2/neu in bladder cancer is one of the highest among all human malignancies tested; such overexpression is thought to play a role in the aberrant proliferation of cancer cells. This study was conducted to evaluate the quantitative assessment of HER2/neu expression by enzyme immunoassay (EIA) and its prognostic significance in differentiating between high and low proliferating tumors. PATIENTS AND METHODS: Tissue samples were collected from 35 patients with benign bladder lesions, 28 with bilharzial bladder cancer, and 25 with nonbilharzial bladder cancer. Twenty normal samples were obtained from normal safety margin areas in nonbilharzial bladder cancer patients. Out of the malignant samples, 22 were found to be squamous cell carcinoma and 31 were transitional cell carcinoma. All samples were examined for HER2/neu expression by EIA and Western blot (WB). Flow cytometric (FCM) analysis was also performed in all the samples provided. RESULTS: HER2/neu was found to be significantly overexpressed in the malignant group compared to the benign and normal groups (P < 0.001) and no significant difference was found between the bilharzial and nonbilharzial cancer groups or between the transitional and squamous cell carcinoma groups. HER2/neu was significantly correlated to ploidy (P = 0.001), synthetic phase fraction, SPF (P = 0.012), and DNA index (P = 0.002). No significant correlation was found between HER2/neu and stage or grade while it was significantly associated with lymph node status of the tumour (P = 0.02). CONCLUSION: HER2/neu can be measured reliably by the EIA method as confirmed by WB. The quantitative assessment of HER2/neu expression in malignant tumors aided by other proliferation markers such as SPF, DI, and ploidy could be useful in selecting patients for more aggressive treatment or for predicting outcome.     

Stimulation of natural killer cells with a CD137-specific antibody enhances trastuzumab efficacy in xenotransplant models of breast cancer

Trastuzumab, a monoclonal antibody targeting human epidermal growth factor receptor 2 (HER2; also known as HER-2/neu), is indicated for the treatment of women with either early stage or metastatic HER2(+) breast cancer. It kills tumor cells by several mechanisms, including antibody-dependent cellular cytotoxicity (ADCC). Strategies that enhance the activity of ADCC effectors, including NK cells, may improve the efficacy of trastuzumab. Here, we have shown that upon encountering trastuzumab-coated, HER2-overexpressing breast cancer cells, human NK cells become activated and express the costimulatory receptor CD137. CD137 activation, which was dependent on NK cell expression of the FcγRIII receptor, occurred both in vitro and in the peripheral blood of women with HER2-expressing breast cancer after trastuzumab treatment. Stimulation of trastuzumab-activated human NK cells with an agonistic mAb specific for CD137 killed breast cancer cells (including an intrinsically trastuzumab-resistant cell line) more efficiently both in vitro and in vivo in xenotransplant models of human breast cancer, including one using a human primary breast tumor. The enhanced cytotoxicity was restricted to antibody-coated tumor cells. This sequential antibody strategy, combining a tumor-targeting antibody with a second antibody that activates the host innate immune system, may improve the therapeutic effects of antibodies against breast cancer and other HER2-expressing tumors.     

Combinatorial effects of lapatinib and rapamycin in triple-negative breast cancer cells

Triple-negative breast cancers, which lack estrogen receptor, progesterone receptor, and HER2/neu overexpression, account for approximately 15% of breast cancers, but occur more commonly in African Americans. The poor survival outcomes seen with triple-negative breast cancers patients are, in part, due to a lack of therapeutic targets. Epidermal growth factor receptor (EGFR) is overexpressed in 50% of triple-negative breast cancers, but EGFR inhibitors have not been effective in patients with metastatic breast cancers. However, mTOR inhibition has been shown to reverse resistance to EGFR inhibitors. We examined the combination effects of mTOR inhibition with EGFR inhibition in triple-negative breast cancer in vitro and in vivo. The combination of EGFR inhibition by using lapatinib and mTOR inhibition with rapamycin resulted in significantly greater cytotoxicity than the single agents alone and these effects were synergistic in vitro. The combination of rapamycin and lapatinib significantly decreased growth of triple-negative breast cancers in vivo compared with either agent alone. EGFR inhibition abrogated the expression of rapamycin-induced activated Akt in triple-negative breast cancer cells in vitro. The combination of EGFR and mTOR inhibition resulted in increased apoptosis in some, but not all, triple-negative cell lines, and these apoptotic effects correlated with a decrease in activated eukaryotic translation initiation factor (eIF4E). These results suggest that mTOR inhibitors could sensitize a subset of triple-negative breast cancers to EGFR inhibitors. Given the paucity of effective targeted agents in triple-negative breast cancers, these results warrant further evaluation.     

Prediction of drug combination chemosensitivity in human bladder cancer

The choice of therapy for metastatic cancer is largely empirical because of a lack of chemosensitivity prediction for available combination chemotherapeutic regimens. Here, we identify molecular models of bladder carcinoma chemosensitivity based on gene expression for three widely used chemotherapeutic agents: cisplatin, paclitaxel, and gemcitabine. We measured the growth inhibition elicited by these three agents in a series of 40 human urothelial cancer cell lines and correlated the GI(50) (50% of growth inhibition) values with quantitative measures of global gene expression to derive models of chemosensitivity using a misclassification-penalized posterior approach. The misclassification-penalized posterior-derived models predicted the growth response of human bladder cancer cell lines to each of the three agents with sensitivities of between 0.93 and 0.96. We then developed an in silico approach to predict the cellular growth responses for each of these agents in the clinically relevant two-agent combinations. These predictions were prospectively evaluated on a series of 15 randomly chosen bladder carcinoma cell lines. Overall, 80% of the predicted combinations were correct (P = 0.0002). Together, our results suggest that chemosensitivity to drug combinations can be predicted based on molecular models and provide the framework for evaluation of such models in patients undergoing combination chemotherapy for cancer. If validated in vivo, such predictive models have the potential to guide therapeutic choice at the level of an individual's tumor.     

含铂双药方案治疗老年非小细胞肺癌的疗效和安全性分析

目的观察顺铂联合长春瑞滨、多西他赛或吉西他滨治疗老年非小细胞肺癌的疗效和安全性。方法回顾性研究分别接受长春瑞滨+顺铂、多西他赛+顺铂和吉西他滨+顺铂方案化疗的114例老年非小细胞肺癌的疗效和副反应。结果 3组治疗的有效率分别为35.71%、39.39%、35.9%。副反应以骨髓抑制常见,白细胞减少3级以上者3组分别为26.2%、33.3%、23.1%,3级以上的血小板减少及贫血在全组病例发生率分别为5.26%、0.88%。结论年龄不是含铂双药化疗的禁忌,老年晚期非小细胞肺癌患者可接受含铂的双药方案化疗,并能取得一定近期疗效。     

赫赛汀联合多西紫杉醇用于局部晚期乳腺癌新辅助化疗近期疗效探讨

目的 探讨赫赛汀联合多西紫杉醇用于局部晚期乳腺癌新辅助化疗的近期疗效及不良反应.方法16例经病理证实为局部晚期乳腺浸润性导管癌患者接受赫赛汀(第1周期8 ms/kg,第2～4周期6ms/ks;静脉注射90 min,第1天)加多西紫杉醇(多西紫杉醇75 ms/m2静脉注射60 min,第2天)术前化疗,3周为1个周期,共4个周期;术前化疗后接受乳腺癌改良根治术或保乳根治术.结果 16例患者总有效率为87.5%,临床完全缓解率为56.3%,病理完全缓解率为25.0%;KPS评分均得到较大改善;主要不良反应为骨髓抑制和胃肠道反应,未出现心脏毒性.结论赫赛汀联合多西紫杉醇用于局部晚期乳腺癌新辅助化疗有较高的有效性和安全性,值得临床进一步探讨,最终结论需大样本的研究结果.     

Antitumor efficacy of trastuzumab in nude mice orthotopically xenografted with human pancreatic tumor cells expressing low levels of HER-2/neu

The monoclonal antibody trastuzumab binds to the extracellular domain of HER-2/neu and induces clinical responses in breast tumors with HER-2 gene amplification and/or protein overexpression. Its role in other tumor types remains to be investigated. We evaluated the antitumor efficacy of trastuzumab in vitro and in nude mice implanted orthotopically with cells of 3 human pancreatic tumor lines expressing only low levels of HER-2/neu, as determined by flow cytometry. Although none of the 3 cell lines showed growth inhibition when cultured directly with trastuzumab, 2 of them, GER and PaCa3, were sensitive to lysis in antibody-dependent cellular cytotoxicity assay. This pattern of response was recapitulated in tumor-bearing mice repeatedly treated with trastuzumab, in which survival was significantly prolonged as compared with controls (P=0.03 for GER and 0.0008 for PaCa3). Incidence of metastases was also reduced, especially in liver. These preclinical results indicate that trastuzumab can exert an antitumor effect against orthotopic human pancreatic cancer xenografts with low-level HER-2/neu expression and that this effect correlates with the in vitro antibody-dependent cellular cytotoxicity susceptibility, suggesting a different role for HER-2/neu in the therapy of tumor types other than breast cancer.     

Synthetic triterpenoid 2-cyano-3,12-dioxooleana-1,9-dien-28-oic acid induces growth arrest in HER2-overexpressing breast cancer cells

HER2 overexpression is one of the most recognizable molecular alterations in breast tumors known to be associated with a poor prognosis. In the study described here, we explored the effect of HER2 overexpression on the sensitivity of breast cancer cells to the growth-inhibitory effects of 2-cyano-3,12-dioxooleana-1,9-dien-28-oic acid (CDDO), a synthetic triterpenoid, both in vitro and in vivo in a xenograft model of breast cancer. Both cell growth and colony formation in the soft agar assay, a hallmark of the transformation phenotype, were preferentially suppressed in HER2-overexpressing cell lines at low concentrations of CDDO, whereas growth-inhibitory effects at high concentrations did not correlate with the expression level of HER2. CDDO dose-dependently inhibited phosphorylation of HER2 in HER2-overexpressing cells and diminished HER2 kinase activity in vitro. CDDO induced the transactivation of the nuclear receptor peroxisome proliferator-activated receptor-gamma in both vector control and HER2-transfected MCF7 cells. Dose-response studies showed that the growth inhibition seen at lower concentrations of CDDO correlated with induction of the tumor suppressor gene caveolin-1, which is known to inhibit breast cancer cell growth. CDDO also reduced cyclin D1 mRNA and protein expression. In vivo studies with liposomally encapsulated CDDO showed complete abrogation of the growth of the highly tumorigenic MCF7/HER2 cells in a xenograft model of breast cancer. These findings provide the first in vitro and in vivo evidence that CDDO effectively inhibits HER2 tyrosine kinase activity and potently suppresses the growth of HER2-overexpressing breast cancer cells and suggest that CDDO has a therapeutic potential in advanced breast cancer.     

NFkB家族蛋白对乳腺癌细胞发生及耐药的影响

目的 :研究NFkB家族蛋白在乳腺癌细胞的表达及与乳腺癌细胞化疗耐药性关系。方法 :培养 14个乳腺癌细胞系 ,对其进行胞浆、胞核蛋白质提取 ,Western印迹法观察NFKB家族蛋白及其抑制物的表达 ,并用MTT药敏实验观察NFkB家族蛋白与乳腺癌细胞化疗耐药性关系。结果 :p5 0、p65和IkB在细胞浆内表达阳性率分别为 10 0 %、71%和 5 0 % ,p5 0、p65同时在胞核内表达 ,p5 0尤为明显 ,阳性率分别为 63%和 35 % ;5个乳腺癌细胞系细胞核MTT检测IC50 值大于 2 0 μg/ml,p5 0表达全部阳性 ,p65 2例阳性 ;p5 0胞核表达阳性者的IC50 值明显高于胞核表达阴性 ,而 p65无明显关系。 结论 :p5 0在乳腺癌细胞的发生中起一定作用 ,且与乳腺癌细胞的耐药关系密切 ,可望成为预后判断的新标志物