Amplification and expression of the c-erb B-2/neu proto-oncogene in human bladder cancer

The c-erb B-2/neu gene encodes a cell-surface glycoprotein with extensive homology to, but distinct from, the epidermal growth-factor receptor. In this study, we compared the c-erb B-2/neu gene amplification and expression of tissue specimens obtained from the bladders of normal controls and patients with high-grade transitional cell bladder carcinoma. Southern blot analysis of DNAs from 24 patients and 5 controls showed 2 cases of c-erb B-2/neu gene amplification in patients and none in controls. Western blot analysis demonstrated that c-erb B-2/neu was expressed in 67.6% (23/34) of patient specimens but in none of the controls (0/5). This finding agreed with the result of immunohistochemical staining, which showed that tissue from 74.3% (26/35) of the patients and none of the controls (0/7) showed positive immunofluorescence staining. This is the first report suggesting that c-erb B-2/neu gene amplification may be associated with human bladder carcinogenesis.     

Prognostic significance of immunohistochemical c-erbB-2 proto-oncogene expression and nuclear DNA content in human breast cancer.

Immunoreactivity of the c-erbB-2 proto-oncogene product and nuclear DNA content were assessed in specimens from 211 breast cancer patients with a mean follow-up of 16 years (range 13-19 years). A routine immunoperoxidase technique was used and cytometrical DNA assessments were performed on cytodiagnostically identified tumour nuclei, using image analysis. C-erbB-2 cell membrane staining was observed in 29% of the cases and was found to be related to tumour size (P = 0.02), histopathological grade (P = 0.02) and nuclear DNA content (P < 0.01). In univariate analysis immunohistochemical c-erbB-2 expression was of prognostic significance among node-positive patients (P = 0.02), but not among women with node-negative disease. This prognostic ability was reduced by multivariate analysis and was no longer significant. In contrast, nuclear DNA content was significantly related to distant recurrence-free survival even in multivariate analysis after adjustment for nodal status and tumour size (P < 0.01). In conclusion, the findings of the present study indicate that c-erbB-2 expression is of limited prognostic value in a subgroup of patients, whereas nuclear DNA content seems to provide significant prognostic information even in node-negative patients.     

Expression of c-erb B-2/neu proto-oncogene in human prostatic cancer tissues and cell lines.

Both amplification and overexpression of c-erb B-2/neu have been associated with the progression and possible prognosis of a number of human cancers. In this study, we demonstrated that c-erb B-2/neu may also play an important role in human prostate cancer. Our conclusion is based on the following observations: (1) A monoclonal antibody raised against a peptide sequence from the C-terminal domain of the human c-erb B-2/neu gene product reacted positively with 68.7% (11 of 16) of the human prostatic cancer tissue extracts analyzed by western blot procedure. These results were supported by the immunohistochemical staining of the prostatic cancer specimens; 80% (12 of 15) showed positive staining, primarily around the plasma membranes of the prostatic cancer cells. c-erb B-2/neu oncoprotein was not detectable in normal prostate tissues (five examined by immunohistochemical staining and three by western blotting) or in human benign prostatic hyperplasia (two examined by immunohistochemical staining and six by western blotting) and was expressed less abundantly with lower intensity in "normal" human prostate tissues adjacent to cancerous prostate tissue (5 of 12 examined by immunohistochemical staining). We observed no evidence of c-erb B-2/neu gene amplification in 10 fresh human prostatic cancer specimens examined by Southern blotting and in the cultured human prostatic cancer cell lines PC-3, DU-145, and LNCaP. (2) The c-erb B-2/neu protein was detected in both androgen-receptor-positive (LNCaP) and -negative (PC-3 and DU-145) human prostate cancer cell lines. Positive immunostaining of c-erb B-2/neu protein was found to be associated predominantly with the plasma membranes of PC-3 cells, but was also found to be widespread in the cytoplasmic region of the LNCaP cells and in the perinuclear region of the DU-145 cells. (3) Like prostate-specific antigen (PSA) expression, c-erb B-2/neu mRNA expression was also positively regulated by androgen in androgen-receptor-positive LNCaP cells in vitro and LNCaP tumors in vivo. When LNCaP tumors were grown in castrated male hosts, levels of c-erb B-2/neu and PSA mRNA expression decreased initially, but rebounded at 3 wk to levels comparable to those expressed by tumors maintained in intact adult male hosts.     

Repressed expression of the HER-2/c-erbB-2 proto-oncogene by the adenovirus E1a gene products.

The E3 region of adenovirus induces down-regulation of epidermal growth factor receptor (EGFR) through endocytosis. Here we report that an EGFR-related protein, the HER-2/c-erbB-2 gene product, p185, is also down-regulated by adenovirus, but via a different mechanism. We found that the adenovirus E1a gene is responsible for the repression of HER-2/c-erbB-2 at the RNA level.     

HER 2/neu protein expression in colorectal cancer

Background  

Conflicting data exist about the prevalence of HER-2/neu overexpression in colorectal cancer ranging from 0 to 83 %. In our study we tried to clarify the extent of expression and its relationship to clinicopathological parameters.     

Expression of the HER-2/neu proto-oncogene in serous ovarian neoplasms.

BACKGROUND. It is unclear whether HER-2/neu proto-oncogene expression in ovarian epithelial neoplasms is related to prognosis. METHODS. The authors performed immunohistochemical stains on 20 serous tumors of low malignant potential (STLMP) in Stages I and II and 19 serious carcinomas in the same stages. They used three different commercial antibodies to make comparisons. RESULTS. Two of four Stage I STLMP in patients who experienced disease progression showed positive staining for the gene product, whereas none of seven Stage I nonprogressive STLMP showed positive staining. Five of the six Stage III nonprogressive STLMP showed positive staining, whereas none of three Stage III STLMP that progressed showed positive staining. Three carcinomas (one Stage I and two Stage III) also showed positive staining. CONCLUSIONS. Expression of HER-2/neu may be associated with high stage in serous ovarian neoplasms, but it is not likely to identify the small fraction of patients with STLMP who will experience disease progression.     

The neu (c-erbB-2) oncogene

The neu gene was first identified in rat tumors that had been induced by the carcinogen ethyl nitrosourea. The human homolog of neu, usually designated c-erbB-2, is located on chromosome 17, q21. It specifies a transmembrane receptor-like phosphoglycoprotein that is closely related to the EGFr (c-erbB-1). The ligand for c-erbB-2 is not known. A significant proportion of adenocarcinomas (especially of the breast, colon, and pancreas) have amplification and/or overexpression of c-erbB-2. The unique qualities associated with the subset of tumors that overexpress c-erbB-2 have not yet been firmly identified.     

HER 2/neu expression and gene amplification in colon cancer

HER 2/neu is an important oncogene in breast cancer, but the prevalence and significance of HER 2/neu gene amplification in colon cancer have been poorly documented. We have evaluated HER 2/neu gene amplification and protein overexpression in a series of colon cancers to assess the frequency, concordance and clinical significance of these events. HER 2/neu gene copy number was measured in 154 primary colon tumors, 15 liver metastases and matched normal tissues using a quantitative PCR/ligase detection reaction (LDR) technique developed and validated in our laboratory. HER 2/neu copy number was confirmed by fluorescent in situ hybridization (FISH) in all tumors found to have gene amplification. In an independent and blinded fashion, HER 2/neu expression was assessed in paraffin sections from 139 of the tumor specimens using the HercepTest kit. HER 2/neu gene amplification was observed in 4 (2.4%) of the 169 tumor specimens and in none of the normal tissues. There was no apparent association with stage of disease, tumor grade or patient survival. Among 139 cases evaluated by immunohistochemistry (IHC), HER 2/neu overexpression was seen in 5 cases (3.6%). There was extremely high concordance (kappa = 0.852) between gene amplification and protein overexpression. The low prevalence of HER 2/neu gene amplification and protein overexpression suggests that this oncogene plays an infrequent role in the development and progression of colon cancer. These data indicate that the primary mechanism of dysregulated HER 2/neu expression in colon cancer, as in breast cancer, is gene amplification.     

c-erbB-2 oncoprotein expression in primary and advanced breast cancer.

Immunoreactivity for c-erbB-2 oncogene product expression has been investigated in patients with breast cancer using the polyclonal antibody 21N. Three series of patients were studied, 602 presenting with primary operable cancer, 57 with stage 3 and 123 with stage 4 disease. Representative tissue sections of each primary tumour were stained using a standard immunoperoxidase technique. Invasive tumour membrane immunoreactivity was assessed and identified in 15% of patients with primary operable cancer and 20% in the advanced breast cancer group. The results demonstrate a relationship between poorer survival and oncogene expression in all three patient groups. Patients in the primary operable cancer group with membrane oncoprotein expression had a poorer outcome, 35% 10-year survival, compared with those in which membrane expression was absent, 55% 10-year survival. The median survival of patients with stage 3 disease with c-erbB-2 membrane positivity was 17 months compared to 24 months with membrane negativity. In stage 4 disease median survival with membrane expression was 8.8 months compared to 19.7 months with no membrane expression. In addition in the series of primary cancers a correlation existed between histological grade and membrane immunoreactivity. Multivariate analysis showed histological grade to be a more powerful prognostic factor than c-erbB-2 protein expression. In conclusion, this study demonstrates, in a large series of patients presenting to one centre, that c-erbB-2 protein expression is a prognostic indicator in patients with primary operable and advanced breast disease.     

HER-2/neu oncogene expression in advanced breast cancer

Tumor tissue from patients with advanced breast cancer was analyzed for HER-2/neu and p53 expression. The tissue samples from primary tumor and from axillary lymph nodes or distant metastases from 118 breast cancer patients were obtained. Sections from formalin-fixed, paraffin-embedded materials were immunostained for HER-2/neu and p53 oncoprotein expression. Staining results were correlated with survival times and disease-free survival times, flow cytometric synthesis phase fractions, and DNA ploidy. No correlation could be found between HER-2/neu and p53 or any other tested factor, but grade I primary cancers that were positive for HER-2/neu showed a tendency for better outcome. The HER-2/neu staining of the metastases was independent of the staining of the primary tumor. HER-2/neu can be used as a prognostic marker for advanced breast cancer, when the primary tumor is well differentiated.     

HER-2/neu receptor in prostate cancer development and progression to androgen independence

Development of prostate cancer and progression to androgen-independent disease is correlated with increased expression of growth factors and receptors capable of establishing autocrine and/or paracrine growth-stimulatory loops. A thorough review was made of the current literature and recent abstract presentations at scientific meetings focusing on the role of the HER-2/neu (c-erbB2) receptor in prostate cancer and the potential clinical usefulness of its specific inhibitors. In the past 10 years, conflicting results on HER-2/neu expression in prostate cancer have been reported. More recently, four studies have shown experimental evidence of HER-2/neu in the development of prostate cancer and, more specifically, in the progression to a hormone-refractory clinical behavior. Furthermore, it has been proposed that HER-2 family and androgen receptors function synergistically in the absence of androgen, which suggests a cross-talk between the HER-2/neu and androgen receptor pathways. Finally, clinical trials are in progress in prostate cancer patients to test novel agents that selectively interfere with HER-2/neu activity.     

甲状腺癌组织c-erbB-2/neu蛋白表达及其临床意义

目的：探讨甲状腺癌中c-erbB-2蛋白（p185）的表达与临床预后因素的相关性及意义。方法：运用免疫组化SP法检测45例甲状腺癌石蜡标本中,p185的表达并与临床预后因素进行相关分析。结果：45例患者中p185蛋白的阳性表达率为71．1％（32／45）。其中乳头状癌的p185为71．0％（22／31）;滤泡癌及髓样癌的p185阳性表达分别为2／4和2／4;未分化癌的p185阳性表达分别为5／6。p185表达与甲状腺癌的组织学类型之间存在明显相关性;与性别及年龄无相关;在有淋巴结转移及有复发、远处转移或死亡的患者中,p185的表达呈明显增强趋势,与无复发组相比较差异有统计学意义,P〈0．05。结论：在甲状腺癌中,p185存在着不同程度的表达,在一定程度上反映了甲状腺癌的组织学分化程度、淋巴结转移和复发倾向;p185的强阳性表达暗示着淋巴结转移概率的增加,将对甲状腺癌的手术方式选择有指导意义;p185的阳性表达可作为判断甲状腺癌预后的临床病理指标。     

Down-regulation of HER2/neu expression induces apoptosis in human cancer cells that overexpress HER2/neu

The HER2/neu oncogene is overexpressed in a significant fraction of human tumors; such overexpression is thought to play a role in the aberrant proliferation of cancer cells. The effects of HER2/neu-specific phosphorothioate antisense oligodeoxyribonucleotides on HER2/neu expression, tumor cell proliferation, and activation of apoptotic cell death pathways have been examined. Antisense treatment down-regulates HER2/neu expression in a dose-dependent and sequence-specific manner. HER2/neu antisense treatment specifically inhibits the growth of tumor lines that overexpress HER2/neu, but it has little effect on the growth of tumor cells that express low levels of HER2/neu. Down-regulation of HER2/neu expression is not only cytostatic, but it also results in the activation of apoptotic cell death pathways in cells that overexpress HER2/neu. These results suggest that, in addition to stimulating tumor cell proliferation, HER2/neu overexpression in cancer cells acts as an antiapoptotic cell survival factor.     

c-erbB-2 (HER-2/neu) protein and drug resistance in breast cancer patients treated with induction chemotherapy

Expression of c-erbB-2 protein has been associated with poor prognosis and poor response to chemotherapy in breast cancer patients. In the present prospective study, we have analyzed whether c-erbB-2, p53 and P170 proteins may be determinants of tumor resistance in locally advanced breast cancer patients treated with induction chemotherapy. Biopsies (n = 60) were examined by immuno-histochemistry; in 62% of cases core or incisional biopsies were taken before drug administration, allowing comparison in paired biopsies of the cytological and molecular changes induced by treatment Sixty percent of the patients received relatively high doses of FAC or FEC (5-fluorouracil, doxorubicin or epirubicin and cyclophosphamide), and 40% received relatively high doses of doxorubicin or epirubicin alone. No significant changes were observed in the molecular markers studied following chemotherapy; in the few biopsies where changes appeared, the changes did not exhibit any significant or similar trend. For 30 of the patients who received FAC/FEC treatment, follow-up reached a median of 34 months. In these cases, neither the clinical (reduction in tumor size) nor the histological (evaluated after neoadjuvant chemotherapy) responses showed statistically significant differences between the patients who developed distant metastases and the disease-free patients. c-erbB-2 was over-expressed in 50% of patients who developed distant metastases vs. 7% of the disease-free patients. Disease free survival (DFS) curves between c-erbB-2-positive and c-erbB-2-negative patients were statistically significant. No correlation between p53 or P170 expression with DFS was found. Our results suggest that c-erbB-2 protein expression is associated with development of distant metastases in breast cancer patients treated with relatively high doses of anthracyclines in induction chemotherapy.     

Dietary fatty acids regulate the activation status of Her-2/neu (c-erbB-2) oncogene in breast cancer cells.

Research from several sources provides strong evidence thatdietary or exogenously derived fatty acids (FAs) may play animportant role in the etiology, evolution and/or progressionof breast cancer [1]. However, the type of individual FAs ina diet, rather than the amount of total dietary fat, may bemore important in breast cancer disease. In this regard, epidemiological,experimental and mechanistic data implicate -9 oleic acid (OA;18:1n-9), the main FA of olive oil, -linolenic acid (ALA; 18:3n-3),the -3 FA of vegetable oils, and eicosapentaneoic (EPA; 22:5n-3)and docosahexaenoic (DHA; 22:6n-3) FAs, the two main -3 FAsof fish oils, as inhibitors of the development and progressionof human breast cancer, and -6 FAs such as linoleic acid (LA;18:2n-6), the main FA of corn and sunflower oils, as stimulatorsof the disease. Moreover, one of the most     

组蛋白酶和c-erbB-2在乳腺癌中的表达

目的探讨乳腺癌病人c-erbB．2和cath-D表达与临床病理及预后的关系。方法通过免疫组化法，检测128例乳腺癌病人的c-erbB-2和cath-D的表达。结果cath-D和c-erbB-2表达与肿块大小、淋巴结转移显著相关（P〈0．0001）。c-erbB-2表达比不表达病人预后差（P=0．01）。结论c-erbB-2阳性表达和cath-D阳性表达者，恶性程度高，易转移、预后差。     

Absence of activating transmembrane mutations in the c-erbB-2 proto-oncogene in human breast cancer

The rat neu proto-oncogene, which is a putative growth factor receptor closely related to the epidermal growth factor receptor, can be activated in vivo by a single point mutation in the sequence encoding its transmembrane region. The human homologue of neu, c-erbB-2, can be activated in vitro to an oncogenic form by point mutations in the same relative position in the gene. We have sought the presence of such activating mutations in a series of 100 cases of human breast cancer by polymerase chain reaction amplification and sequence-specific oligonucleotide hybridization, and also by a designed restriction fragment length polymorphism strategy in cases with Southern blot evidence of c-erbB-2 amplification. No evidence of activating point mutations in the c-erbB-2 protooncogene was found in any of these cases.     

Gefitinib prevents cancer progression in mice expressing the activated rat HER2/neu

We tested the efficacy of gefitinib in the prevention of HER2/neu-mediated breast cancer development in BALB-NeuT transgenic mice. Oral administration of gefitinib to female transgenic mice from 5 to 14 weeks of age reduced tumor multiplicity from 9.6 +/- 0.82 to 0.58 +/- 1.1 (83%). We observed a decrease in the number and size of lobules and lobular nodules in treated mice with a reduction in the overall disease burden per gland. Normal duct development in the mammary glands was not affected by gefitinib. The development of acinic cell carcinoma in the parotid glands of these animals was also reduced coincident with decreased stromal involvement during progression. Gefitinib eliminated phosphorylation of HER2 and HER3 and signaling through MAPK and Akt in lobular hyperplasias and carcinomas. At the same time MAPK activity and cytokine production in splenocytes and lymph nodes was increased in gefitinib-treated animals coincident with an increase in lymph node size. Delaying gefitinib treatment until mammary glands exhibited atypical lobular hyperplasias reduced efficacy. These studies demonstrate the critical role of HER2 signal transduction in the onset and progression of HER2/neu-dependent breast cancer and suggest a role for specific inhibitors to prevent the outgrowth of early hyperplastic disease.     

Gene amplification and expression of the neu (c-erbB-2) sequence in human mammary carcinoma

Alterations in the structure and expression of the neu oncogene were investigated in 15 human mammary tumors. In 7 of the samples (46%), amplification by the factor up to 14 was detected, some samples displaying an additional EcoRI restriction fragment at 3.4 kb. In tumor tissue with amplified neu sequences from which intact RNA was available, enhanced expression was noted. Correlation of the molecular data to clinical parameters indicated a correlation of the neu oncogene amplification to tumor grading and thus poor prognosis.