HER-2/neu oncogene expression, DNA ploidy and proliferation index in breast cancer.

HER-2/neu gene expression, DNA ploidy and proliferation index were studied in 250 cases of breast cancer. Expression of HER-2/neu was determined by using an antibody to the HER-2/neu receptor. Ki-67 antibody was used to determine the proliferation index of the breast cancers, and the Feulgen method was used to assess DNA amounts in the tumor cells. Histochemical staining was quantitated by image analysis. Of the cancers studied, 72 were positive for overexpression of HER-2/neu protein; of these, 62 (86%) possessed near-tetraploid DNA content, and 47 (65%) had more than one G0G1 stem line (polyploid) of DNA distribution. Cells from the cases negative for HER/2-neu overexpression contained DNA amounts that ranged from diploid to varying degrees of aneuploid. A significant difference in the amounts of cellular proliferation in HER-2/neu overexpressing cancers was found between those that expressed the HER-2/neu receptor on their membranes and those that exhibited mainly cytoplasmic receptors.     

Structure and inducible regulation of the human c-erb B2/neu promoter

Overexpression of the p185 product of the c-erb B2/neu gene is correlated with cell transformation and tumorigenesis. To study expression of this gene, a 1548-base pair fragment (-1571 to -24 bp relative to the ATG initiator codon) of the human c-erb B2/neu 5'-noncoding region was isolated, sequenced, and analyzed with respect to basal and inducible activity using the luciferase expression vector pSVOAL delta 5'. This fragment contained an Alu repetitive element which was confirmed in two independent clones. Basal activity of the 1548-base pair fragment was equivalent to the epidermal growth factor receptor promoter region and 32 and 16% as active as the Herpes simplex thymidine kinase and Rous sarcoma virus promoters, respectively. Induction of luciferase activity was observed in response to epidermal growth factor, 12-O-tetradecanoylphorbol-13-acetate, dibutyryl cAMP, and retinoic acid. Additive and synergistic responses with more than 30-fold increases were observed after treatment with combinations of inducing agents, indicating complex regulation of this gene. These results show that the promoter region of the c-erb B2/neu gene contains sequences that dictate regulatory responses to several environmental signals.     

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。     

HER-2/neu oncogene expression and DNA ploidy in normal human kidney and renal cell carcinoma.

Using flow cytometry (FCM), we have investigated both the DNA content (stained with propidium iodide) and HER-2/neu oncogene expression (revealed by means of an anti-HER-2/neu monoclonal antibody) in neoplastic and non-neoplastic kidney samples from 20 patients with renal cell carcinoma. All the non-neoplastic samples and 15/20 (75%) renal cell cancers showed diploid modal DNA content while the remaining 5 neoplastic sample (25%) showed both diploid and hyperdiploid cell populations. In normal kidney the level of HER-2/neu oncoprotein was low (median fluorescence values in arbitrary units = 7.5 AU, range: 4-10 AU). In diploid renal cancers the level of HER-2/neu was slightly increased (median fluorescence values = 20 AU, range: 9.5-30 AU) (p < .005). The relationship of HER-2/neu expression to the cell cycle in these tumor samples is not clear since most of the cells express the antigen in all phases of the cell cycle. On the other hand, there is an association between HER-2/neu expression and abnormal DNA content suggesting that aneuploid pattern may be biologically related to overexpression of the HER-2/neu gene.     

Monitoring therapy by serum HER-2/neu

We have evaluated the performance of the Bayer Immuno 1 serum HER-2/neu assay. The precision is excellent and varied between 1.7% and 2.1% at values of HER-2/neu ranging from 16.8 ng/mL to 108.6 ng/mL. In normal women who were followed on a monthly basis the average deviation was 6%. The concentration (mean +/- SD) in normal women was 8.7 +/- 3.2 ng/mL. There was no difference between pre and postmenopausal women. The normal/abnormal cutoff was defined as greater than 15 ng/mL. In normal women and those with benign disease the specificity varied between 95% and 100%. In women with breast cancer the sensitivity was 1.7% in stage I disease, 3.0% in stage II, 16.7 in stage III and 35.5% in stage IV. There were 56 elevations (14.7%) in the total group of 285 women with breast cancer. There was an excellent correlation with a microtitre plate method (r=0.9944). Longitudinal studies showed clearly that women who expressed HER-2/neu in their tissue had elevated serum levels and these levels reflected the clinical course of the patient. More extensive control studies are required to establish the role of HER-2/neu assays in the management of women with breast cancer.     

Immunogenic HER-2/neu peptides as tumor vaccines

During the last decade, a large number of tumor-associated antigens (TAA) have been identified, which can be recognized by T cells. This has led to renewed interest in the use of active immunization as a modality for the treatment of cancer. HER-2/neu is a 185-KDa receptor-like glycoprotein that is overexpressed by a variety of tumors including breast, ovarian, lung, prostate and colorectal carcinomata. Several immunogenic HER-2/neu peptides recognized by cytotoxic T lymphocytes (CTL) or helper T lymphocytes (TH) have been identified thus far. Patients with HER-2/neu over-expressing cancers exhibit increased frequencies of peripheral blood T cells recognizing immunogenic HER-2/neu peptides. Various protocols for generating T cell-mediated immune responses specific for HER-2/neu peptides have been examined in pre-clinical models or in clinical trials. Vaccination studies in animals utilizing HER-2/neu peptides have been successful in eliminating tumor growth. In humans, however, although immunological responses have been detected against the peptides used for vaccination, no clinical responses have been described. Because HER-2/neu is a self-antigen, functional immune responses against it may be limited through tolerance mechanisms. Therefore, it would be interesting to determine whether abrogation of tolerance to HER-2/neu using appropriate adjuvants and/or peptide analogs may lead to the development of immune responses to HER-2/neu epitopes that can be of relevance to cancer immunotherapy. Vaccine preparations containing mixtures of HER-2/neu peptides and peptide from other tumor-related antigens might also enhance efficacy of therapeutic vaccination. This article is a symposium paper from the conference “Progress in Vaccination against Cancer 2004 (PIVAC 4)”, held in Freudenstadt-Lauterbad, Black Forest, Germany, on 22–25 September 2004     

Preliminary evaluation of HER-2/neu oncogene and epidermal growth factor receptor expression in normal and neoplastic human ovaries.

The HER-2/neu oncogene (a member of the Erb-like oncogene family) is distinct from but closely related to the c-erb B gene which encodes the epidermal growth factor receptor (EGFr). HER-2/neu gene amplification was found in a large number of mammary carcinomas and there was a strong correlation between this phenomenon and poor prognosis. In our study HER-2/neu oncogene expression was determined in 16 malignant ovarian tumors, 2 ovarian lymphomas and 5 normal ovaries. The HER-2/neu gene was found both in normal ovaries and malignant tumors, without any apparent difference among the various histological types. In all the specimens examined, HER-2/neu expression did not seem to be related to EGF binding capacity.     

Preliminary evaluation of HER-2/neu oncogene and epidermal growth factor receptor expression in normal and neoplastic human ovaries.

The HER-2/neu oncogene (a member of the Erb-like oncogene family) is distinct from but closely related to the c-erb B gene which encodes the epidermal growth factor receptor (EGFr). HER-2/neu gene amplification was found in a large number of mammary carcinomas and there was a strong correlation between this phenomenon and poor prognosis. In our study HER-2/neu oncogene expression was determined in 16 malignant ovarian tumors, 2 ovarian lymphomas and 5 normal ovaries. The HER-2/neu gene was found both in normal ovaries and malignant tumors, without any apparent difference among the various histological types. In all the specimens examined, HER-2/neu expression did not seem to be related to EGF binding capacity.     

Application of a gene vaccine targeting HER-2/neu in immunocontraception

HER-2/neu was widely used as a target for tumor prevention and therapy because of its overexpression in many tumors. However, it also plays an important role in proliferation of endometrium, embryo implantation, and development. Here, HER-2/neu was used in immunocontraception. A gene vaccine encoding the extracellular domain of human HER-2/neu was constructed. After immunization, it especially elicited both humoral and cellular responses in mice. Embryo implantation was interfered by intravenous and intraluminal injection of anti-HER-2/neu serum or lymphocytes. Lower fertility was induced after vaccination when compared with the control groups, while injuries to the uterus and ovary were not observed. Our results suggested a new and impactful target for contraceptive vaccines development.     

基质金属蛋白酶-2和p185HER-2/neu蛋白在卵巢癌中的研究进展

基质金属蛋白酶-2(Matrix Metalloproteinase-2,MMP-2)是基质金属蛋白酶家族的重要成员,能降解明胶蛋白和Ⅳ型、V型胶原,在细胞外基质的降解过程中起着关键作用,能够促进肿瘤细胞发生侵袭和转移。p185HER-2/neu蛋白是一种相对分子质量185×103的跨膜糖蛋白,由HER-2/neu基因编码,属于酪氨酸激酶受体家族,p185HER-2/neu蛋白在人类多种癌症中存在扩增及过量表达,并与肿瘤的侵袭性表型及生存期短密切相关。就基质金属蛋白酶-2和p185HER-2/neu蛋白的生物学特性,与卵巢癌侵袭转移和预后的关系及MMP-2和p185HER-2/neu蛋白的研究情况等予以综述。     

HER-2/neu blocks tumor necrosis factor-induced apoptosis via the Akt/NF-kappaB pathway

Overexpression of HER-2/neu correlates with poor survival of breast and ovarian cancer patients and induces resistance to tumor necrosis factor (TNF), which causes cancer cells to escape from host immune defenses. The mechanism of HER-2/neu-induced TNF resistance is unknown. Here we report that HER-2/neu activates Akt and NF-kappaB without extracellular stimulation. Blocking of the Akt pathway by a dominant-negative Akt sensitizes the HER-2/neu-overexpressing cells to TNF-induced apoptosis and inhibits IkappaB kinases, IkappaB phosphorylation, and NF-kappaB activation. Our results suggested that HER-2/neu constitutively activates the Akt/NF-kappaB anti-apoptotic cascade to confer resistance to TNF on cancer cells and reduce host defenses against neoplasia.     

Her-2/neu oncogene expression in Puerto Rican females with breast cancer.

Her-2/neu belongs to the family of tyrosine kinase transmembrane proteins whose overexpression has been associated with a poor prognosis in patients with breast cancer. The product of this proto-oncogene is overexpressed in 25-30% of human breast cancer and is the target of selective immunotherapy. Concerned about the ethnic differences on the expression of this oncogene, we have evaluated 143 consecutive specimens of primary breast cancer diagnosed in San Pablo Hospital, Puerto Rico. The specimens were analyzed for Her-2/neu expression using immunohistochemistry assays (Hercept test). We have related the expression of hormone receptor status, percent cells in S phase, DNA ploidy, tumor size, nodal status and menopausal state with the Her2/neu expression. Out of 143 specimens, 28 overexpressed the Her-2/neu (19.6%). Of the Her/2 negative 30/114 (26%) were estrogen receptor negative as compared to 9/27 (33%) (p = 0.464). The degree of aneuploidy was abnormal in 25/104 (24%) in the Her-2/neu negative vs 11/27 (41%) p = 0.083. The percent cell in DNA synthesis was high in 16/77 (21%) in Her-2/neu negative vs 4/15 (27%) p = 0.613. The tumor size was greater than 2 cm in 35/106 (33%) in Her-2/neu negative vs 9/23 (39%) p = 0.575. In the progesterone specimens negative for Her2, 44/114 (39%) were Her2/neu negative vs 15/27 (56%) p = 0.108. No differences were seen regarding menopausal status, age and nuclear grading. A trend favoring abnormal aneuploidy in Her2/neu positive was seen. Nodal involvement was significantly associated with Her2/neu overexpression. (p = 0.037). Although the incidence of Her2 overexpression found in this database was somewhat lower than the one reported in the literature, this might also be due to the small cohort examined or to the technique utilized.     

ADVIA Centaur HER-2/neu shows value in monitoring patients with metastatic breast cancer

INTRODUCTION:The proteolytic breakdown product corresponding to the extracellular domain (ECD) of the HER-2/neu oncoprotein p185 is found in the circulation of healthy individuals and patients having cancers of epithelial origin. For the current evaluation we sought to determine the analytical performance as well as the clinical utility of the newly developed ADVIA Centaur HER-2/neu assay (Bayer HealthCare LLC, Diagnostics Division, Tarrytown, NY, USA) in monitoring patients with metastatic breast cancer during the course of disease and treatment and to compare the obtained results with those of CA 15-3. METHODS: The analytical performance (including precision, normal range, interfering substances, minimum detectable concentration, dilution recovery, spiking recovery and high-dose hook effect) were determined. HER-2/neu and CA 15-3 values were measured in retrospective samples obtained from 59 patients with metastatic breast cancer undergoing treatment over a 6-12 month period. Serial changes in serum HER-2/neu and CA 15-3 were correlated with changes in clinical status on a visit-to-visit basis. For each pair of serial measurements, changes of equal to or greater than, or less than 15% for HER-2/neu and 21% for CA 15-3 were considered to indicate progression or lack of progression, respectively. RESULTS: The ADVIA Centaur HER-2/neu assay demonstrated within-run imprecision and total imprecision ranging from 3.0-5.6% and from 3.2-5.7%, respectively. The upper limit of normal was 15.2 ng/mL (90% CI: 14.2-17.0 ng/mL). No significant interference (<5%) was seen with bilirubins, hemoglobin, triglycerides and cholesterol or therapeutic drugs commonly present in the sera of breast cancer patients. The minimum detectable concentration (analytical sensitivity) was found to be 0.5 ng/mL. The patient population in the clinical study included breast cancer patients who responded to therapy (stable, partial or complete response) or had disease progression. HER-2/neu levels showed a concordance of 78.1% (82/105 restaging time points) with the clinical course of disease, whereas CA 15-3 levels showed a concordance of 76.2% (80/105 restaging time points). The concordance with clinical status increased to 85.7% (90/105 restaging time points) when both results were used in combination as a series test. CONCLUSIONS: The ADVIA Centaur HER-2/neu assay provides excellent analytical performance for serial testing of serum HER-2/neu levels. The clinical data demonstrate the usefulness of serum HER-2/neu in monitoring metastatic breast cancer patients during treatment. Furthermore, the results indicate that serum HER-2/neu and CA 15-3 may be useful in identifying disease progression or therapeutic response in different subgroups of women with metastatic breast cancer.     

HER-2/neu peptide specificity in the recognition of HLA-A2 by natural killer cells

Although natural killer (NK) cells have been described as non-MHC-restricted, new evidence suggests that NK activity can be either up- or down-regulated after interaction with the peptide–MHC-class-I complex expressed on target cells. However, the epitope(s) recognized by NK cells have remained ill-defined. We investigated NK cell recognition of synthetic peptides representing a portion of a self-protein encoded by the HER-2/neu (HER-2) proto-oncogene and presented by HLA-A2. HER-2 nonapeptides C85, E89, and E75 were found partially to protect T2 targets from lysis by freshly isolated and interleukin-2(IL-2)-activated NK cells (either HLA-A2⁺ or A2⁻). This inhibition was not solely due to changes in the level of HLA-A2 expression or conformation of serological HLA-A2 epitopes. Using single-amino-acid variants at position 1 (P1) of two HER-2 peptides, we observed that protection of targets was dependent on the sequence and the side-chain. These results suggest similarities in the mechanism of target recognition by NK and T cells. This information may be important for understanding the mechanisms of tumor escape from immunosurveillance and could help explain the aggressiveness of HER-2-overexpressing tumor cells. Received: 16 March 1999 / Accepted: 3 June 1999     

HER-2/neu raises SHP-2, stops IFN-gamma anti-proliferation in bladder cancer

Gene amplification or HER-2/neu protein overexpression signals a poor outcome for bladder cancer patients. We investigated the anti-proliferative effect of IFN-gamma in HER-2/neu-transfected human bladder cancer cells (TCC-N5 and TCC-N10). The cells continued growing after IFN-gamma stimulation but did not activate the Janus kinase (Jak)/Stat pathway. We found Jak/Stat protein phosphatase in TCC-N5 and TCC-N10 cells with upregulated Src homology 2-containing protein tyrosine phosphatase-2 (SHP-2). After the cells had been treated with AG825, a HER-2/neu-specific inhibitor, SHP-2 expression declined, and Jak2/Stat1 reactivated. Similar results were reported in a mouse bladder cancer cell line, MBT2, with constitutive HER-2/neu overexpression. Further, AG825 pretreatment restored the anti-proliferation activity of IFN-gamma in TCC-N5 and TCC-N10 cells. Therefore, the suppression of IFN-gamma signaling in HER-2/neu-overexpressing bladder cancer cells might be due to SHP-2 upregulation. The regulation of SHP-2 by HER-2/neu provides a new target for blocking the HER-2/neu oncogenic pathway.     

Targeting nucleic acids into mitochondria: Progress and prospects

Given the essential functions of these organelles in cell homeostasis, their involvement in incurable diseases and their potential in biotechnological applications, genetic transformation of mitochondria has been a long pursued goal that has only been reached in a couple of unicellular organisms. The challenge led scientists to explore a wealth of different strategies for mitochondrial delivery of DNA or RNA in living cells. These are the subject of the present review. Targeting DNA into the organelles currently shows promise but remarkably a number of alternative approaches based on RNA trafficking were also established and will bring as well major contributions.