Trastuzumab (Herceptin) in the adjuvant treatment of HER-2-positive early breast cancer

The prognosis of HER-2-positive breast cancer (characterized by amplification of the HER-2 oncogene and/or overexpression of HER-2 receptor) is unfavourable. Trastuzumab (Herceptin), a monoclonal antibody against HER-2 receptor can improve the outcome of HER-2-positive breast cancer. Up to now this was proven only in advanced disease. Recently five large multicentric phase III adjuvant trials gave level one evidence on the benefit of adjuvant treatment with Herceptin, concerning disease-free survival (DFS) and overall survival (OS). Herceptin has decreased the relative risk of recurrence with about 50% and that of death with nearly 30% in HER-2-positive early breast cancer. Based on these results Herceptin, together with chemotherapy, has been recently approved for the adjuvant treatment of HER-2-positive breast cancer.     

Current therapeutic options for gastric adenocarcinoma

Gastric cancer inflicts significant health issues globally despite its declining incidence. The disease is known to be diagnosed at its advanced stages also corresponding with a poor prognosis for patients. The integral therapeutic choices to cure advanced gastric cancer have progressed swiftly in modern days. The preface of molecularly targeted therapeutic techniques would potentiate the personalized approach depending on patient-specific and tumor-specific features, exasperating the advantages of chemotherapy. Here we have reviewed the modern therapeutics such as immune therapy, chemotherapy, m-RNA based therapeutics, alongside evaluating the influence of age, sex and comorbidities-like factors on the occurrence of gastric cancer. Gastric cancer therapy consolidated target agents comprising inhibitors of programmed death-1(PD-1), human epidermal growth factor receptor 2 (HER2), mRNA, and epidermal growth factor receptor (EPGF). A combination of trastuzumab to platinum-mediated chemotherapy evolved has a typical front-line therapy in advanced gastric cancer. An attempt has been made to epitomize the contemporary-modern research on targeted therapy for advanced gastric cancer.     

Establishment and characterization of a cell line (BTIC) including HER-2-positive cells derived from pleural effusion of recurrent breast invasive ductal carcinoma, scirrhous type

Human epidermal growth factor receptor-2 (HER-2) overexpression in breast cancer occurs in 20% to 30% of patients with breast cancer. Trastuzumab (Herceptin) targets HER-2 tyrosine kinase receptors expressed on tumor cells and mediates anti-proliferative effects against HER-2-positive tumor cells. Adjuvant chemotherapy with trastuzumab has improved the prognosis of patients with HER-2 positive high-grade breast cancer. However, patients often experience appearance and proliferation of recurrent tumor cells after trastuzumab treatment. In this study, we report the successful establishment and characterization of a cell line (BTIC) derived from a patient with recurrent breast cancer after adjuvant chemotherapy with trastuzumab. Characteristics of the BTIC cell line were investigated by phase contrast or electron microscopic observations, chromosome analysis, xenotransplantation, immunohistochemistry and radioimmunoassay for tumor markers. We confirmed that the BTIC cell line grown as multilayered culture in culture dishes, has a poorly developed endoplasmic reticulum in the cytoplasm and some desmosomes. The population doubling time was approximately 44 hr. A graft in nude mouse after xenotransplantation was diagnosed as scirrhous carcinoma. Immunohistochemistry on cultured BTIC cells revealed that the BTIC cells were negative for estrogen receptor and progesterone receptor, and 30% positive for HER-2. Radioimmunoassay indicated secretion of HER-2 protein, NCC-ST-439 and CA15-3.     

HER-2/neu基因高表达及靶向治疗

HER-2/neu癌基因在许多肿瘤,如乳腺癌、卵巢癌、非小细胞肺癌等肿瘤中高表达,在肿瘤的发生与发展中起重要作用,与肿瘤的转化、转移、复发、预后差、患者生存期缩短有关。HER-2/neu在乳腺癌过度表达率约为20%～30%,编码蛋白P185HER2属生长因子受体家族,抗P185HER2单克隆抗体(Herceptin)作为靶向药物已临床应用治疗HER2/neu高表达乳腺癌。     

Correlation analysis of lymphocyte-monocyte ratio with pathological complete response and clinical prognosis of neoadjuvant chemotherapy in patients with breast cancer

PurposeInflammation plays an important role in tumor proliferation, metastasis, and chemotherapy resistance. Peripheral blood lymphocyte-monocyte ratio (LMR) has been reported to be closely associated with the prognosis of many tumors, such as certain hematologic malignancies and gastric cancer. However, the association in breast cancer is still not clear. This study investigated the relationship between LMR with pathological complete response and clinical prognosis of neoadjuvant chemotherapy in patients with breast cancer, to provide convenient and accurate predictive indicators for pathological complete response (pCR) and prognosis.MethodsThe clinicopathological data of 192 female breast cancer patients who received neoadjuvant chemotherapy and surgery in Harbin Medical University Tumor Hospital from January 2013 to August 2017 were retrospectively analyzed. Blood lymphocytes and monocytes were obtained by peripheral venous punctures.ResultsCompared with the low LMR group, pCR was more easily obtained in the high LMR group (P=0.020); Subgroup analysis showed that patients with the high LMR and HER-2(+) group were more likely to obtain pCR (P=0.011).Univariate andmultivariate results showed that the overall survival (OS) and disease free survival (DFS) of the high LMR group were longer than that of the low LMR group.ConclusionLMR and HER-2 status are correlated with pCR of neoadjuvant chemotherapy in breast cancer patients and are independent predictors of pCR after neoadjuvant chemotherapy in breast cancer patients. Meanwhile, both LMR and T stage of tumor are independent prognostic factors of breast cancer patients, with good predictive value.     

EGFR,HER-2 and KRAS in Canine Gastric Epithelial Tumors: A Potential Human Model?

Epidermal growth factor receptor (EGFR or HER-1) and its analog c-erbB-2 (HER-2) are protein tyrosine kinases correlated with prognosis and response to therapy in a variety of human cancers. KRAS mediates the transduction of signals between EGFR and the nucleus, and its mutation has been identified as a predictor of resistance to anti-EGFR drugs. In human oncology, the importance of the EGFR/HER-2/KRAS signalling pathway in gastric cancer is well established, and HER-2 testing is required before initiating therapy. Conversely, this pathway has never been investigated in canine gastric tumours. A total of 19 canine gastric epithelial neoplasms (5 adenomas and 14 carcinomas) were retrospectively evaluated for EGFR/HER-2 immunohistochemical expression and KRAS mutational status. Five (35.7%) carcinomas were classified as intestinal-type and 9 (64.3%) as diffuse-type. EGFR was overexpressed (≥1+) in 8 (42.1%) cases and HER-2 (3+) in 11 (57.9%) cases, regardless of tumour location or biological behaviour. The percentage of EGFR-positive tumours was significantly higher in the intestinal-type (80%) than in the diffuse-type (11.1%, p = 0.023). KRAS gene was wild type in 18 cases, whereas one mucinous carcinoma harboured a point mutation at codon 12 (G12R). EGFR and HER-2 may be promising prognostic and therapeutic targets in canine gastric epithelial neoplasms. The potential presence of KRAS mutation should be taken into account as a possible mechanism of drug resistance. Further studies are necessary to evaluate the role of dog as a model for human gastric cancer.     

Targeted therapy in breast cancer: the HER-2/neu gene and protein

The HER-2/neu oncogene, a member of the epidermal growth factor receptor or erb gene family, encodes a transmembrane tyrosine kinase receptor that has been linked to prognosis and response to therapy with the anti-HER-2-humanized monoclonal antibody, trastuzumab (Herceptin, Genentech, South San Francisco, CA) in patients with advanced metastatic breast cancer. HER-2/neu status has also been tested for its ability to predict the response of breast cancer to other therapies including hormonal therapies, topoisomerase inhibitors, and anthracyclines. This review includes an analysis of 80 published studies encompassing more than 25,000 patients designed to consider the relative advantages and disadvantages of the various methods of measuring HER-2/neu in clinical breast cancer specimens. Southern blotting, PCR amplification detection, and fluorescence in situ hybridization assays designed to detect HER-2/neu gene amplification are compared with HER-2/neu protein overexpression assays performed by immunohistochemical techniques applied to frozen and paraffin-embedded tissues and enzyme immunoassays performed on tumor cytosols. The significance of HER-2/neu overexpression in ductal carcinoma in situ and the HER-2/neu status in uncommon female breast conditions and male breast cancer are also considered. The role of HER-2/neu testing for the prediction of response to trastuzumab therapy in breast cancer is reviewed along with the current studies designed to test whether HER-2/neu status can predict the response to standard and newer hormonal therapies, cytotoxic chemotherapy, and radiation. The review will also evaluate the status of serum-based testing for circulating HER-2/neu receptor protein and its ability to predict disease outcome and therapy response.     

血清cfDNA、VEGFA与晚期胃癌患者化疗疗效和预后的关系研究

摘要 目的：研究血清循环游离脱氧核糖核酸（cfDNA）、血管内皮生长因子A（VEGFA）与晚期胃癌患者化疗疗效和预后的关系。方法：选取2018年6月~2020年6月在空军第九八六医院接受含奥沙利铂方案化疗的晚期胃癌患者108例,所有患者均接受含奥沙利铂方案化疗,化疗2个周期后,根据实体瘤疗效评价标准（RECIST）1.1版评估疗效分为敏感组和不敏感组,比较两组血清cfDNA、VEGFA水平;随访24个月,Kaplan-Meier生存曲线分析血清cfDNA、VEGFA高表达和低表达组的总生存期（OS）,采用Cox风险比例模型进行预后多因素分析。结果：不敏感组血清cfDNA、VEGFA水平显著高于敏感组（P＜0.05）。cfDNA、VEGFA高表达组患者中位OS均明显短于cfDNA、VEGFA低表达组（P＜0.05）。Cox回归模型单因素分析显示,性别、年龄、部位与晚期胃癌预后无关（P＞0.05）,而TNM分期Ⅳ期、分化程度低分化、有淋巴结转移、化疗疗效不敏感、cfDNA高水平、VEGFA高水平与晚期胃癌预后差显著相关（P＜0.05）。Cox回归模型多因素分析显示,淋巴结转移、化疗疗效不敏感及cfDNA、VEGFA水平高是晚期胃癌患者预后的危险因素（P＜0.05）。结论：血清cfDNA、VEGFA水平检测有助于晚期胃癌患者化疗疗效监测和预后评估。     

Synergistic Role between p53 and JWA: Prognostic and Predictive Biomarkers in Gastric Cancer

Expression of p53 appears to be correlated to prognosis in patients with malignancy, but its role in gastric carcinoma has remained controversial. Recently we reported that JWA, an ADP-ribosylation-like factor 6 interacting protein 5 (ARL6ip5), was both prognostic for overall survival and predictive for platinum-based treatment of gastric cancer. In this study, we aimed to investigate p53 expression as a prognostic and predictive marker in resectable gastric cancer, alone and in combination with JWA. Expression of p53 was examined in three large patient cohorts (total n = 1155) of gastric cancer. High expression of p53 was significantly correlated with unfavorable clinicopathologic parameters and decreased overall patient survival. Furthermore, patients with high p53 expression in tumors acquired remarkable survival benefit from adjuvant first-line platinum-based-chemotherapy. The synergy between p53 and JWA in predicting patient outcome was demonstrated, while no significantly elevated predictive value concerning chemotherapy was observed. Thus, p53 expression is a potent prognostic and predictive factor for resectable gastric cancer with adjuvant platinum-based chemotherapy. A combined effect of p53 with JWA as efficient prognostic indicators was found for the first time.     

曲妥珠单抗联合常规化疗治疗HER-2过度表达晚期贲门癌患者的临床效果与2年预后

目的：观察并探讨曲妥珠单抗（herceptin,HCP）联合常规化疗治疗HER-2过度表达晚期贲门癌患者的临床疗效与药物安全性分析并化疗后2年内随访结果。方法：将我院2008年11月-2009年10月间入选的HER-2表达＂＋＋＂及以上的72例晚期贲门癌患者随机单盲分为观察组（37例）与对照组（35例）,对照组患者采用DCF（多西紫杉醇、顺铂、5-氟尿嘧啶）动脉灌注化疗方案,观察组在此基础上联合使用靶向药物HCP,对比两组化疗结束后临床效果、生活质量改善情况、化疗中药物不良反应及2年内生存率。结果：①观察组与对照组化疗效果与生活质量改善情况构成不同（P〈0.05）,观察组部分缓解比例（62.2%）、总有效率（64.9%）及生活质量改善比例（64.9%）均高于对照组水平（42.9%、42.9%、42.9%）;②两组不良发生情况相仿,观察组出现Ⅱ度及以发热（52.8%）、寒战（45.9%）比例与出现心功能障碍的比例（10.8%）高于对照组比例（22.9%、17.1%、0.0%）;③观察组与对照组24个月生存率分别为43.2%、20.0%,死亡者平均存活时间分别为（14.7±2.8）m、（12.5±2.1）m,两指标差别均具有统计学意义（P〈0.05）。结论：HCP联合DCF化疗方案能明显改善HER-2过度表达晚期贲门癌患者疗效与生活质量,并延长患者生存时间,但应警惕联合用药中的心血管毒性。     

胃癌中HER-2 蛋白和NF-κB 蛋白的表达及其临床意义

目的:探究人类表皮生长因子受体-2 (HER-2)和核因子-κB(NF-κB)在胃癌中的表达及二者之间的关系.方法:收集检测武汉大学附属中南医院2007年1月～2009年12月75例胃癌手术切除的组织和22例癌旁正常胃组织,HER-2和NF-κB的表达检测采用免疫组织化学SP法;分析其与胃癌临床病理特征的关系以及二者之间的相关性.结果:胃癌中HER-2和NF-κB的阳性率分别为24.00 ％(18/75)和62.67 ％(47/75);两者与年龄、性别均无相关性,而与分期、分级和是否转移相关(P＜0.05); HER-2与肿瘤大小无相关性,但NF-κB与肿瘤大小相关(P＜0.01).HER-2阳性时NF-κB的阳性率为94.44 ％(17/18),HER-2阴性时NF-κB的阳性率为52.63 ％(30/57),两者的表达有显著相关性(X2=8.514,P＜0.01).结论:胃癌中NF-κB、HER-2蛋白的表达具有相关性,在胃癌的发生发展中具有重要作用.     

Cisplatin resistance in gastric cancer cells is involved with GPR30-mediated epithelial-mesenchymal transition

Cisplatin is the major chemotherapeutic drug in gastric cancer, particularly in treating advanced gastric cancer. Tumour cells often develop resistance to chemotherapeutic drugs, which seriously affects the efficacy of chemotherapy. GPR30 is a novel oestrogen receptor that is involved in the invasion, metastasis and drug resistance of many tumours. Targeting GPR30 has been shown to increase the drug sensitivity of breast cancer cells. However, few studies have investigated the role of GPR30 in gastric cancer. Epithelial-mesenchymal transition (EMT) has been shown to be associated with the development of chemotherapeutic drug resistance. In this study, we demonstrated that GPR30 is involved in cisplatin resistance by promoting EMT in gastric cancer. GPR30 knockdown resulted in increased sensitivity of different gastric cancer (GC) cells to cisplatin and alterations in the epithelial/mesenchymal markers. Furthermore, G15 significantly enhanced the cisplatin sensitivity of GC cells while G1 inhibited this phenomenon. In addition, EMT occurred when AGS and BGC-823 were treated with cisplatin. Down-regulation of GPR30 with G15 inhibited this transformation, while G1 promoted it. Taken together, these results revealed the role of GPR30 in the formation of cisplatin resistance, suggesting that targeting GPR30 signalling may be a potential strategy for improving the efficacy of chemotherapy in gastric cancer.     

The role of GLI2-ABCG2 signaling axis for 5Fu resistance in gastric cancer

Gastric cancer is a leading cause of cancer-related mortality worldwide, and options to treat gastric cancer are limited. Fluorouracil(5Fu)-based chemotherapy is frequently used as a neoadjuvant or an adjuvant agent for gastric cancer therapy. Most patients with advanced gastric cancer eventually succumb to the disease despite the fact that some patients respond initially to chemotherapy. Thus, identifying molecular mechanisms responsible for chemotherapy resistance will help design novel strategies to treat gastric cancer. In this study, we discovered that residual cancer cells following 5Fu treatment have elevated expression of hedgehog(Hg) target genes GLI1 and GLI2, suggestive of Hh signaling activation. Hh signaling, a pathway essential for embryonic development, is an important regulator for putative cancer stem cells/residual cancer cells. We found that high GLI1/GLI2 expression is associated with some features of putative cancer stem cells, such as increased side population. We demonstrated that GLI2 knockdown sensitized gastric cancer cells to 5Fu treatment, decreased ABCG2 expression, and reduced side population. Elevated GLI2 expression is also associated with an increase in tumor sphere size, another marker for putative cancer stem cells. We believe that GLI2 regulates putative cancer stem cells through direct regulation of ABCG2. ABCG2 can rescue the GL12 shRNA effects in 5Fu response, tumor sphere formation and side population changes, suggesting that ABCG2 is an important mediator for GLI2-associated 5Fu resistance. The relevance of our studies to gastric cancer patient care is reflected by our discovery that high GLI1/GLI2/ABCG2 expression is associated with a high incidence of cancer relapse in two cohorts of gastric cancer patients who underwent chemotherapy(containing 5Fu). Taken together,we have identified a molecular mechanism by which gastric cancer cells gain 5Fu resistance.     

曲妥珠单抗在HER-2阳性乳腺癌治疗中的研究进展

乳腺癌是女性最常见的恶性肿瘤之一,中国女性乳腺癌发病率逐年上升。人表皮生长因子受体2(human epidermal growth factor receptor-2,HER-2)在近三分之一的乳腺癌患者中呈现基因扩增或受体蛋白高表达。HER-2阳性的乳腺癌患者预后差,术后复发风险高、生存期短。曲妥珠单抗是人表皮生长因子受体-2的特异性抑制剂[1],在HER-2阳性乳腺癌患者的治疗中得到了广泛的应用,并且曲妥珠单抗分子靶向治疗相比于传统的化疗,具有特异性较强,毒副反应相对较小等优点。它改变了HER-2阳性乳腺癌患者的自然疾病进程,延长了患者的生存时间。本文将从四个方面对曲妥珠单抗在HER-2阳性乳腺癌患者治疗中的研究、应用及进展进行综述。     

High Expression of Heat Shock Protein 90 Is Associated with Tumor Aggressiveness and Poor Prognosis in Patients with Advanced Gastric Cancer

The heat shock protein 90 (HSP90) is overexpressed and highly associated with poor prognosis in many malignancies. However, the role of HSP90 in gastric cancer has not been thoroughly elucidated. The aim of this study is to investigate the relationship of HSP90 expression with clinicopathological parameters and prognosis in advanced gastric cancer, and estimate the alteration of HSP90 expression after neoadjuvant chemotherapy. HSP90 and matrix metallopeptidase 9 (MMP-9) antigen expression was evaluated by immunohistochemistry in 322 advanced gastric carcinoma samples. The relationships between HSP90 and clinicopathological parameters and prognosis were analyzed. The response of HSP90 level was assessed in chemotherapeutic effect in 54 patients received 1–2 cycles of neoadjuvant chemotherapy. The positive expression of HSP90 was found to be 69.6% in 322 advanced gastric carcinoma samples. HSP90 protein expression was significantly associated with depth invasion (P<0.001), lymph node metastasis (P<0.001) and stage of disease (P<0.001). The positive rates of HSP90 expression were higher in both prominent serosal invasion group (P<0.001) and lymph node metastasis group (P<0.001). Moreover, HSP90 was significantly correlated with MMP-9 among 322 gastric cancer tissues (P<0.001). In univariate and multivariate analyses, HSP90 was an independent prognostic factor for both recurrence-free survival (RFS) and overall survival (OS). These results suggested that HSP90 may play an important role on tumor invasion, metastasis and prognosis, and might act as a promising target for prognostic prediction.     

胃癌中HER-2蛋白和NF-KB蛋白的表达及其临床意义

目的：探究人类表皮生长因子受体-2（HER-2）和核因子．KB（NF-KB）在胃癌中的表达及二者之间的关系。方法：收集检测武汉大学附属中南医院2007年1月-2009年12月75例胃癌手术切除的组织和22例癌旁正常胃组织,HER-2和NF—KB的表达检测采用免疫组织化学sP法;分析其与胃癌临床病理特征的关系以及二者之间的相关性。结果：胃癌中HER-2和NF-KB的阳性率分别为24．00％（18／75）和62．67％（47／75）;两者与年龄、性别均无相关性,而与分期、分级和是否转移相关（P〈0．05）;HER-2与肿瘤大小无相关性,但NF—KB与肿瘤大小相关（P〈0．01）。HER-2阳性时NF-KB的阳性率为94．44％（17／18）,HER-2阴性时NF-KB的阳性率为52．63％（30／57）,两者的表达有显著相关性（x2=8．514,P〈0．01）。结论：胃癌中NF-KB、HER-2蛋白的表达具有相关性,在胃癌的发生发展中具有重要作用。     

Tumor-targeting,systemically delivered antisense HER-2 chemosensitizes human breast cancer xenografts irrespective of HER-2 levels

BACKGROUND: The failure to respond to chemotherapy is a major obstacle in the successful treatment of breast cancer. We have previously shown that anti-HER-2 antisense oligonucleotide (AS HER-2 ODN) treatment was able to sensitize breast cancer cells to various chemotherapeutic agents in vitro irrespective of their HER-2 status, indicating that the use of AS HER-2 ODN therapy for breast cancer is not limited to tumors overexpressing the protein. One of the main drawbacks to the use of antisense therapy in the clinical setting is the lack of an efficient, tumor-targeting, systemic delivery method. We have developed a tumor-specific, ligand-targeting, cationic liposome delivery system designed for systemic gene therapy of cancer. In this study we employ this ligand-liposome strategy to enhance the delivery of the AS Her-2 ODN to breast cancer cells, including those that do not overexpress HER-2, in vitro and in vivo. MATERIALS AND METHODS: A cationic liposome complex that includes folate as the targeting ligand was designed and optimized for more efficient delivery of AS HER-2 ODN to breast tumors cells in vitro, and more significantly, for systemic delivery with tumor-specific targeting in vivo. Human breast cancer cell line MDA-MB-435, which does not overexpress HER-2, was used to compare the degree of chemosensitization to the taxanes of AS HER-2 ODN delivered via the optimized folate-liposome versuscommercial Lipofectin. MDA-MB-435 xenograft tumors were also used to evaluate the anti-tumor effect of the combination of systemically delivered folate-liposome-AS HER-2 ODN and docetaxel (Taxotere). RESULTS: The optimized folate-liposome-AS HER-2 ODN complex significantly increases the response of breast tumor cell lines to conventional chemotherapeutic agents in vitro as compared to AS HER-2 delivered via an unliganded commercially available reagent, Lipofectin. In vivo, the folate-liposome-AS HER-2 ODN complex has prolonged stability in blood and increased uptake in tumors. More significantly, the combination of intravenously administered ligand-liposome-AS HER-2 ODN and docetaxel resulted in a marked inhibition of xenograft growth in an aggressive breast cancer model that does not overexpress HER-2, even after treatment ended. CONCLUSIONS: Although there are other reports of liposomal delivery of AS ODNs, this is the first report of in vivo efficacy against human cancer cells using a tumor-targeting liposome delivery system for systemic AS therapy. Moreover, the increased stability in circulation and anti-tumor efficacy observed were obtained without the need for continuous intravenous infusion. HER-2 is an integral component within a network of cell growth pathways that can affect many different types of tumors where HER-2 may be a contributing factor, such as ovarian, esophageal, and GI malignancies including colon and pancreatic cancers. Therefore, the effectiveness of this therapy with xenograft tumors that do not overexpress HER-2 has the potential to expand the clinical usefulness of this efficacious form of therapy.     

A HER-2/neu peptide admixed with PLA microspheres induces a Th1-biased immune response in mice

The elimination of cancer cells requires strong cellular immune responses, and these responses are induced by the activation of Th1 lymphocytes. In this work, the possibility of inducing a Th1 type of immune response in vivo by mixing a HER-2/neu synthetic CTL (cytotoxic T lymphocyte) peptide [HER-2/neu (789-797)], with poly-lactide (PLA) microspheres was investigated. Various formulations of the peptide were administered to HLA-A2.1 transgenic (HHD) mice. Cellular experiments, assessing proliferation and cytokine determination in splenocyte culture supernatants, were carried out in order to evaluate the type of immune response to the antigen. The in vivo administration of the peptide antigen admixed with the PLA microspheres induced a potent immune response which was comparable to that induced by the combination of the antigen in complete Freund's adjuvant (CFA). Furthermore, the cytokine profile produced by the T lymphocytes of the immunized animals indicated that the combination of the peptide antigen with the PLA microspheres induced a strong Th1 biased immune response to the antigen. The time of peptide incubation with the microspheres prior to administration did not affect the immune response, which further simplifies the preparation of this type of vaccine. The results justify further investigation of the possibility of inducing effective cellular immune responses against cancer cells overexpressing HER-2/neu molecules by simply mixing appropriate HER-2/neu peptide antigens with PLA microspheres.