2064

ERBB2

CD340|HER-2|HER-2/neu|HER2|MLN 19|NEU|NGL|TKR1;v-erb-b2 erythroblastic leukemia viral oncogene homolog 2, neuro/glioblastoma derived oncogene homolog (avian);ERBB2;v-erb-b2 erythroblastic leukemia viral oncogene homolog 2, neuro/glioblastoma derived oncogene homolog (avian)

c-erb B2/neu protein|herstatin|metastatic lymph node gene 19 protein|neuroblastoma/glioblastoma derived oncogene homolog|p185erbB2|proto-oncogene Neu|proto-oncogene c-ErbB-2|receptor tyrosine-protein kinase erbB-2|tyrosine kinase-type cell surface recepto

17q11.2-q12|17q21.1

protein-coding

Primary malignant epithelial tumors of the liver (PMETL) are rare in the pediatric age group, and very little is known about their biology as compared with adult tumors. The prognostic value of the DNA contents measured by image analysis and expression of oncogene c-erb2 and tumor suppressor gene p53 were studied in 30 cases of PMETL in children, including 24 with hepatoblastomas (HB)and 6 with hepatocellular carcinomas (HCC). p53 overexpression was detected in 12 out of 26 cases (46.0%), or in 3 of 5 HCC and 9 of 21 HB cases. A relatively high concordance of staining was observed with the two antibodies used (clone DO7, Dako and clone DO1, Santa Cruz Biotechnology). c-erb-B2 did not yield the characteristic membrane staining in any of the 27 cases in which reliable staining was obtained. However, 1 out of 4 patients with HCC and 1 of 23 with HBrevealed strong granular cytoplasmic staining in several neoplastic cells. Interestingly, these were two of the three aneuploid multiploid cases. DNA histograms of 13 out of 29 cases (54.8%) were classified as DNA aneuploid (5/6 HCC and 8/23 HB): nine were hyperdiploid, one was hypodiploid (1HB), and three were multiploid (2HB and 1HCC). In the HB group, DNA aneuploidy was strongly associated with embryonal histological areas, suggesting that a disturbance in the process of cell differentiation is associated with marked genetic aberrations. Only the group of HB was submitted to univariate analysis of survival by the Kaplan-Meier method for age (< 24 months vs. > or = 24 months), sex, preoperative chemotherapy (yes vs. no), residual disease (metastasis, and/or unresectable tumor), p53 expression by immunohistochemistry (positive vs. negative), and DNA ploidy (diploid vs. aneuploid). Only residual disease at the time of diagnosis (P < 0.017) and preoperative chemotherapy (0.030) were found to be negatively correlated with biological behavior, estimated as overall survival. DNA aneuploidy tumors (P < 0.125) and male patients (P = 0.123) showed a trend toward a more aggressive clinical behavior, although the difference was not statistically significant. Combining DNA ploidy and residual disease, patients were categorized into three groups: group I, patients with no adverse prognosticfactors, i.e., diploid tumors without residual disease; group II, patients with only one adverse prognostic factor, i.e., aneuploid tumor or residual disease; and group III, patients with both adverse factors, aneuploid tumors and residualdisease at time of diagnosis. A log-rank test comparing the three survival curves showed a statistically significant difference between them (P < 0.003). Althoughthe series of cases is small, the results of this study highlight the importanceof including DNA ploidy in the protocols designed for HB in children by international cooperative groups.

PURPOSE: Osteosarcoma (OS) and skeletal Ewing's sarcoma (EWS), the most common pediatric primary bone tumors, are aggressive malignancies with a tendency for early pulmonary metastasis. Advances in therapy have increased the overall 5-year survival to approximately 70%; however, patients who relapse often fail to respond to salvage therapy. Thus, more effective adjuvant chemotherapy is neededfor these patients. Several reports have claimed expression of the HER2/neu (c-erbB-2) gene in a high percentage of OSs and that its expression is a poor prognostic factor and have advocated monoclonal antibody therapy in those cases.EXPERIMENTAL DESIGN AND RESULTS: To validate the expression of HER2/neu in thesetumors, archival cases of OS (n = 66) and EWS (n = 11) from 44 patients were assessed for HER2/neu gene expression by immunohistochemistry (DAKO rabbit polyclonal antibody A0485). Thirty-four cases (44%) demonstrated granular cytoplasmic staining, but none showed the distinct membranous staining characteristic of expression exhibited by breast carcinomas. To validate these immunohistochemical results, reverse transcription-PCR using RNA derived from archival material (n = 48) and several different primer pairs also failed to demonstrate the presence of amplifiable HER2/neu mRNA, although a known HER2/neu-positive breast carcinoma showed amplifiable mRNA. CONCLUSIONS: Thus, in contrast to previous reports, our results demonstrate an absence of HER2/neu expression in OSs and EWSs. Our results show that HER2/neu is not expressed by these sarcomas, and we conclude that HER2/neu is therefore not an important prognostic factor and that anti-HER2/neu monoclonal antibody therapy is not appropriate for these patients.

PURPOSE: Osteosarcoma (OS) and skeletal Ewing's sarcoma (EWS), the most common pediatric primary bone tumors, are aggressive malignancies with a tendency for early pulmonary metastasis. Advances in therapy have increased the overall 5-year survival to approximately 70%; however, patients who relapse often fail to respond to salvage therapy. Thus, more effective adjuvant chemotherapy is neededfor these patients. Several reports have claimed expression of the HER2/neu (c-erbB-2) gene in a high percentage of OSs and that its expression is a poor prognostic factor and have advocated monoclonal antibody therapy in those cases.EXPERIMENTAL DESIGN AND RESULTS: To validate the expression of HER2/neu in thesetumors, archival cases of OS (n = 66) and EWS (n = 11) from 44 patients were assessed for HER2/neu gene expression by immunohistochemistry (DAKO rabbit polyclonal antibody A0485). Thirty-four cases (44%) demonstrated granular cytoplasmic staining, but none showed the distinct membranous staining characteristic of expression exhibited by breast carcinomas. To validate these immunohistochemical results, reverse transcription-PCR using RNA derived from archival material (n = 48) and several different primer pairs also failed to demonstrate the presence of amplifiable HER2/neu mRNA, although a known HER2/neu-positive breast carcinoma showed amplifiable mRNA. CONCLUSIONS: Thus, in contrast to previous reports, our results demonstrate an absence of HER2/neu expression in OSs and EWSs. Our results show that HER2/neu is not expressed by these sarcomas, and we conclude that HER2/neu is therefore not an important prognostic factor and that anti-HER2/neu monoclonal antibody therapy is not appropriate for these patients.

In the wake of recent progress in understanding the genetic pathways involved inthe development of brain tumors, a major goal is to correlate molecular data with clinical outcome, survival, and response to treatment modalities. This is of particular importance among the pediatric population. Reliable prognostic factors could potentially permit a tailoring of therapy in that only patients with the most aggressive tumors would receive the most intense treatments. A survey of publications about prognosis-related molecular features among pediatric brain tumors revealed 74 series, of which 46 presented statistically significant outcome-associated parameters as defined by a p value <0.05. Most investigationsrevealing significant prognosis-related features were performed on medulloblastomas (34 publications), followed by astrocytic tumors (6 publications) and ependymomas (5 publications). Promising approaches and molecular markers include gene expression profiles, DNA ploidy, loss of heterozygosity and chromosomal aberrations as detected by CGH and FISH (1q, 17p,17q), as well as oncogenes/ tumor suppressor genes and their proteins (TP53, PTEN, c-erbB2, N-myc, c-myc), growth factor and hormonal receptors (PDGFRA, VEGF, EGFR, HER2, HER4, ErbB-2, hTERT, TrkC), cell cycle genes (p27) and cell adhesionmolecules, as well as factors potentially related to therapeutic resistance (multi-drug resistance, DNA topoisomerase IIalpha, metallothionein, P-glycoprotein, tenascin). This review discusses the predictive potential of molecular markers for clinical outcome and their influence on therapeutic decision-making among children with brain tumors.

pediatric malignant non-brainstem glioma (PMNBG) is a rare tumor that accounts for only about five percent of childhood intracranial neoplasms. DNA topoisomerase IIalpha (TIIalpha) is a novel marker of cell-cycle turnover and a target of high-risk chemotherapy in PMNBG. We have shown that TIIalpha protein expression strongly correlates with event-free and overall survival in these malignancies. The molecular mechanism causing the varying TIIalpha protein expression in PMNBG remains unknown. Utilizing a combined approach of immunocytochemistry-based morphology guidance, laser-assisted microdissection and quantitative real-time PCR, we report a low-level co-amplification of the neighboring TIIalpha and Her-2/neu gene loci on chromosome 17q11-q22 in one of seventeen examined PMNBGs. Analysis of both genes by real-time PCR in the crude tumor samples without prior tissue heterogeneity reduction via laser microdissection, resulted in loss of detection of amplification of the syngeneicHer-2/neu locus. Gene dosage assessment in a microscopically distant tumor area revealed no amplification of either gene. Our results suggest that low-level amplification of the TIIalpha gene locus may be a sporadic mechanism of increased TIIalpha protein expression in PMNBG, which can coincide with low-level amplification of Her-2/neu. The observed intratumor genetic heterogeneity for TIIalpha in PMNBGs may have an impact on the relevance of TIIalpha as a biological constituent of outcome in these neoplasms.

The HER2 gene, located on 17q, encodes a 185-kD transmembrane tyrosine kinase receptor. Amplification of this gene with overexpression of the gene product occurs in about 30% of cases of breast cancer and is considered to be a poor prognostic indicator for this tumor. Results for HER2 expression in osteosarcomaare controversial, with some studies reporting up to 61% of positive cases and others reporting only negative results. Further, expression of HER2 is reported to be a favorable prognostic indicator by some groups and unfavorable by others.The present study used tissue microarrays containing 34 samples of osteosarcoma from 18 patients to analyze HER2 expression by immunohistochemistry and gene copy number by chromogenic in situ hybridization. The microarray included 13 pretreatment biopsies, 11 posttreatment resection specimens, and 10 resected metastases and comprised 18 osteoblastic, 6 chondroblastic, 5 fibroblastic, and 5 mixed subtypes. HER2 protein expression was seen in 4 of 34 (12%) tumor samples that originated from 2 of 18 patients (11%). The staining pattern was consistently weak and focal, and immunohistochemical overexpression of the HER2 protein, defined as complete membrane positivity, was never observed. Further, the presence of HER2 gene amplification was not detected in any osteosarcoma by chromogenic in situ hybridization. Therefore, therapies based on antibodies directed against the HER2 protein are unlikely to have much value in the treatment of pediatric osteosarcomas. From a technical standpoint, this study also demonstrates the value of tissue microarrays in screening tumors at the protein and gene levels using conventional light microscopy.

Familial osteosarcoma is a rare hereditary disease. We present a 37-year-old father and a 17-year-old son who developed osteosarcoma in the left and right distal femurs, respectively, at a three-year interval. They were treated with chemotherapy followed by surgery. Both had positive immunostaining for p53 tumorsuppressor gene and HER-2/neu oncogene. The son also exhibited deletion of the retinoblastoma 1 gene. Pulmonary metastasis was detected in the father at the time of diagnosis and 13 months after primary treatment, whereas no distant metastasis was present in the child. The father died 39 months after the diagnosis from primary symptoms, but the son led a disease-free survival a year after completion of treatment. Genetic abnormalities documented in the father and son corroborate the presence of specific genetic alterations in the pathogenesisof osteosarcoma.

HER2 is essential for normal embryonic development and has a critical function in oncogenesis and progression of some types of cancer. Neuroblastic tumors create a heterogenous group of pediatric embryonal tumors of sympathoadrenal lineage. Thebiological and prognostic function of HER2 in these tumors is not well established. In this study, we evaluated the status of HER2, its prognostic significance, and clinicopathological correlations in series of 79 untreated neuroblastoma. The immunohistochemical assessment of HER2 and Ki-67 (proliferation index) as well as HER2 copy number status were performed on tissue microarrays. HER2 expression characterized 63 tumors, including 34 with low and 29 with high level, showing either membranous or mixed membranous-cytoplasmic pattern. Sixteen cases were HER2 immunonegative. The pattern of immunolabeling depended on the maturity of neuroblastic cells, being the most intense in differentiating neuroblasts. None of the tumors revealed HER2 amplification. In the examined group, 20% of patients died of disease from 4 to 107 months (median18) from the diagnosis, and the survivors were followed up for 14-149 months (median 59). Patients' age, stage of disease, tumor location, mitosis/karyorrhexis index (MKI), and presence of HER2 expression were statistically significantly related to survival probability as detected by the Cox proportional hazard model. In the univariate analysis, Kaplan-Meier curves revealed significantly poorer outcome of HER2 negative than HER2-positive tumors(either low or high expression). The immunonegativity was associated with adverse clinicopathological parameters, including poor survival, metastatic stage of disease, un- or poorly differentiated histology, high MKI, and higher proliferation index. In conclusion, HER2 expression, not accompanied by gene amplification, is common in neuroblastic tumors. HER2 positivity seems to have apositive prognostic significance. HER2 expression with a variable pattern is a marker of the stage of neuroblastic cells differentiation.

BACKGROUND: Recent advances in multidisciplinary treatment approaches have improved the overall prognosis of pediatric brain tumors, but some patients remain refractory to treatment and do poorly. Several molecularly targeted therapies are under development for the treatment of brain tumors, and high-grade gliomas in adults are a particular area of study. PROCEDURE: To better understand if these new therapies can be used in pediatric populations, we examined the expression of the following seven marker genes involved in signaling pathways targeted by new therapies: beta-catenin, suppressor of fused (SUFU), erythroblastic leukemia viral oncogene homolog (ERBB) 2, platelet-derived growthfactor receptoralpha (PDGFRalpha), proliferating cell nuclear antigen (PCNA), secreted protein acid and rich in cysteine (SPARC), and granulocyte colony-stimulating factor receptor (G-CSFR). Samples from 27 patients with the primitive neuroectodermal tumor (PNET)/medulloblastomas (MBs) (n = 8), ependymomas (n = 5), or gliomas (n = 14) were assessed by quantitative real-timePCR. [Correction made here after initial online publication]. We assigned an EXPscore to compare across samples and determined the levels of gene expression among tumor cell types. RESULTS: Gene expression varied among the different tumors, but, within a tumor type, clear expression patterns were seen. The expression of SUFU, ERBB2, and PCNA in metastatic MBs were greater than that seen in non-metastatic MBs. Most glioma cases highly expressed PDGFRalpha and G-CSFR.Additionally, the expression patterns of gliomas and ependymomas were similar (r= 0.77, P = 0.04), but PNET/MBs substantially differed from gliomas (r = -0.37, P = 0.41) or ependymomas (r = 0.23, P = 0.62). CONCLUSIONS: The development of newdrugs targeting up-regulated pathways may be useful for the treatment of pediatric brain tumors. As new drugs are developed, gliomas and ependymomas may be treated with similar compounds.#CI- Copyright (c) 2011 Wiley Periodicals, Inc.

Recent in vitro studies of the epidermal growth factor receptor (EGFR) family have revealed complex signaling interactions involving the production of ligand-mediated heterodimers synergistic for the transformation of cells in vitro. In a series of 70 patients with childhood medulloblastoma, we have used immunohistochemistry and Western blotting analysis to investigate the expressionpatterns of ALL four EGFR family members (EGFR, HER2, HER3, and HER4) and heregulin-alpha, a ligand for the HER3 and HER4 receptors. The majority of casesexpressed two or more receptor proteins; coexpression of the HER2 and HER4 receptors occurred in 54%. expression of the ligand heregulin-alpha was detectedin 31% of tumors. To investigate whether coexpression results in receptor heterodimerization, we have also performed immunoprecipitation analysis of protein extracts from primary tumors, and we demonstrate various patterns of receptor interaction including between HER2 and HER4. In multivariate 25-year survival analysis with clinicopathological disease features, no individual receptor or heregulin-alpha achieved significance. In contrast, when considered together in the multivariate model, coexpression of HER2 and HER4 demonstrated independent prognostic significance (P = 0.006). These data suggest the hypothesis that HER2-HER4 receptor heterodimerization is of particular biological significance in this disease, and this report is the first to demonstrate potential clinical significance of EGFR family heterodimerization in human cancer. Finally, we have also analyzed expression of the AP-2 transcription factor implicated in the positive regulation of HER2 and HER3 gene transcriptionin malignant cells and reveal an association between AP-2 expression and not only HER2 and HER3, but also HER4 levels in medulloblastoma primary tumors.