Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:O76050 (neu)
 3,969 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Overexpression of the HER2/NEU gene is associated with aggressive behavior and poor prognosis in breast cancer, making the Her2/neu protein a directed-therapy target. Tumors of two Puerto Rican (PR) patients overexpressed Her2/neu and resulting partial clinical responses motivated us to compare Her2/neu expression in PR (n = 101) and Caucasian non-Hispanic (n = 95) patients. Immunohistochemistry of tumors showed overexpression of p-Stat3, Cyclin D1, and Her2/neu, compared to non-neoplastic mucosa. Her2/neu and EGF-R protein levels were statistically significantly different with higher levels of both proteins in the PR group. Importantly, Her2/neu expression was strong and diffuse in tumors with signet-ring morphology, while other histo-pathological subtypes showed higher intra-tumoral Her2/neu heterogeneity than typically observed in breast cancer. Targeted therapies in gastric cancer directed at EGF-R and Hers-2/neu pathways warrant further investigation. These therapies may be especially effective in PR patients and in patients with signet-ring cell morphologies with a dismal prognosis.
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PMID:Signal transduction proteins in tumors from Puerto Rican and Caucasian gastric adenocarcinoma patients: expression differences with potential for specific targeted therapies. 1822 43

Cancer is a genetic disease. Breast cancer tumorigenesis can be described as a multi-step process in which each step is thought to correlate with one or more distinct mutations in major regulatory genes. The question addressed is how far a multi-step progression model for sporadic breast cancer would differ from that for hereditary breast cancer. Hereditary breast cancer is characterized by an inherited susceptibility to breast cancer on basis of an identified germline mutation in one allele of a high penetrance susceptibility gene (such as BRCA1, BRCA2, CHEK 2, TP53 or PTEN). Inactivation of the second allele of these tumour suppressor genes would be an early event in this oncogenic pathway (Knudson's "two-hit" model). Sporadic breast cancers result from a serial stepwise accumulation of acquired and uncorrected mutations in somatic genes, without any germline mutation playing a role. Mutational activation of oncogenes, often coupled with non-mutational inactivation of tumour suppressor genes, is probably an early event in sporadic tumours, followed by more, independent mutations in at least four or five other genes, the chronological order of which is likely less important. Oncogenes that have been reported to play an early role in sporadic breast cancer are MYC, CCND1 (Cyclin D1) and ERBB2 (HER2/neu). In sporadic breast cancer, mutational inactivation of BRCA1/2 is rare, as inactivation requires both gene copies to be mutated or totally deleted. However, non-mutational functional suppression could result from various mechanisms, such as hypermethylation of the BRCA1 promoter or binding of BRCA2 by EMSY. In sporadic breast tumorigenesis, at least three different pathway-specific mechanisms of tumour progression are recognizable, with breast carcinogenesis being different in ductal versus lobular carcinoma, and in well differentiated versus poorly differentiated ductal cancers. Thus, different breast cancer pathways emerge early in the process of carcinogenesis, ultimately leading to clinically different tumour types. As mutations acquired early during tumorigenesis will be present in all later stages, large-scale gene expression profiling using DNA microarray analysis techniques can help to classify breast cancers into clinically relevant subtypes.
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PMID:Oncogenic pathways in hereditary and sporadic breast cancer. 1535 Oct 94

The ErbB2 (Her2/neu epidermal growth receptor family) oncogene is overexpressed in 30% to 40% of human breast cancers. Cyclin D1 is the regulatory subunit of the holoenzyme that phosphorylates and inactivates the retinoblastoma (pRb) tumor suppressor and is an essential downstream target of ErbB2-induced tumor growth. Herein, we demonstrate that ErbB2 induces the activity of the Notch signaling pathway. ErbB2 induction of DNA synthesis, contact-independent growth, and mammosphere induction required Notch1. ErbB2-induced cyclin D1 and cyclin D1 expression was suficient to induce Notch1 activity, and conversely, genetic deletion of Notch1 in mammary epithelial cells using foxed Notch (Notch(fl/fl)) mice demonstrated that cyclin D1 is induced by Notch1. Genetic deletion of cyclin D1 or small interfering RNA (siRNA) to cyclin D1-reduced Notch1 activity and reintroduction of cyclin D1 into cyclin D1-deficient cells restored Notch1 activity through the inhibition of Numb, an endogenous inhibitor of Notch1 activity. Thus, cyclin D1 functions downstream as a genetic target of Notch1, amplifies Notch1 activity by repressing Numb, and identifies a novel pathway by which ErbB2 induces Notch1 activity via the induction of cyclin D1.
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PMID:ErbB2 induces Notch1 activity and function in breast cancer cells. 2044 31

The concept of targeting G(1) cyclin-dependent kinases (CDKs) in breast cancer treatments is supported by the fact that the genetic ablation of Cdk4 had minimal impacts on normal cell proliferation in majority of cell types, resulting in near-normal mouse development, whereas such loss of Cdk4 completely abrogated ErbB-2/neu-induced mammary tumorigenesis in mice. In most human breast cancer tissues, another G(1)-regulatory CDK, CDK2, is also hyperactivated by various mechanisms and is believed to be an important therapeutic target. In this report, we provide genetic evidence that CDK2 is essential for proliferation and oncogenesis of murine mammary epithelial cells. We observed that 87% of Cdk2-null mice were protected from ErbB-2-induced mammary tumorigenesis. Mouse embryonic fibroblasts isolated from Cdk2-null mouse showed resistance to various oncogene-induced transformation. Previously, we have reported that hemizygous loss of Cdc25A, the major activator of CDK2, can also protect mice from ErbB-2-induced mammary tumorigenesis [Cancer Res (2007) 67(14): 6605-11]. Thus, we propose that CDC25A-CDK2 pathway is critical for the oncogenic action of ErbB-2 in mammary epithelial cells, in a manner similar to Cyclin D1/CDK4 pathway.
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PMID:Cdk2-null mice are resistant to ErbB-2-induced mammary tumorigenesis. 2153 84

TAAs (tumor-associated antigens) microarrays were designed to detect auto-antibodies directly in patient sera. Twelve different probes were chosen according to their described occurrence in cancer pathologies (Cyclin B1, Cyclin D1, Complement factor H, c-myc, IMP1, p53, p62, survivin, Her2/neu, Koc, NY-ESO-1 and PSA). Microarrays of these 12 proteins were immobilized within the nitrocellulose/cellulose acetate membrane of a 96-well filtering microtiter plate bottom. The captured auto-antibodies were detected using a staining approach based on alkaline phosphatase labeling. Thus, the presence of specific auto-antibodies in samples was visualized through the positive staining of the corresponding TAA spots. The TAA HiFi microarrays were shown to be able to capture specific purified anti-TAA antibodies. In real samples, 9 proteins from the 12 TAAs panel were shown to generate specific signal and 5 antigens (p53, NY-ESO-1, IMP1, cyclin B1 and c-myc) were shown to have interaction with more than 10% of the positive sera from cancer patients. This protein subpanel was proven to be able to detect 72.2% of the cancer patients tested (within a 34 panel of 18 patients and 16 healthy donors).
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PMID:Multiplexed immunoassay for the rapid detection of anti-tumor-associated antigens antibodies. 2166 12

DCIS is a heterogeneous group of non-invasive cancers of the breast characterized by various degrees of differentiation and unpredictable propensity for transformation into invasive carcinoma. We examined the expression and prognostic value of 9 biological markers with a potential role in tumor progression in 133 patients with pure DCIS treated with breast conserving surgery alone, between 1982-2000. Histology was reviewed and immunohistochemical staining was performed. Pearson correlation coefficient was used to determine the associations between markers and histopathological features. Univariate and multivariate analysis examined associations between time to recurrence and clinicopathologic features and biological markers.Median age at diagnosis was 55 years (25-85). With a median follow up of 8.91 years, 41/133 patients recurred (21 as invasive recurrence). In this cohort 13.5% had low, 43% intermediate and 42% high nuclear grade. Comedo necrosis was found in 65% of cases. Expression of ER (62.4%), PR (55.6%), HER2/neu (31.6%), MIB1 (39.8%), p53 (22.6%), p21 (39.8%), Cyclin D1 (95.5%) calgranulin (20.5%), psoriasin (12%), was found in DCIS. HER2/neu was overexpressed in 45% that recurred as DCIS and 42.9% that recurred as invasive cancer, and only in 26.1% in cases that never recurred. On univariate analysis, HER2/neu overexpression was the only marker associated with an increased risk for any recurrence (p = 0.044). The hazard ratio for recurrence for HER2/neu positive DCIS was 1.927 (confidence interval 1.016-3.653) compared to HER2 negative DCIS. On multivariate analysis, HER2/neu overexpression remained the only independent variable significantly associated with any recurrence (p = 0.014) and with invasive recurrence (p = 0.044).This data suggest that HER2/neu testing may become an important parameter in the management of DCIS and the treatment of cases with positive HER2/neu status could be modified accordingly, similar to the current approach for HER2/neu positive invasive disease.
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PMID:Biological Markers Predictive of Invasive Recurrence in DCIS. 2189 61

Breast carcinoma is a heterogeneous disease affected by patients' ethnicity. Gene expression analysis identified several molecular subtypes, and similar subtyping has now been found to be feasible using immunohistochemistry. This study estimated the distribution of intrinsic breast cancer subtypes using estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2 (Her2/neu), and cytokeratin 5/6 immunostaining in a cohort of 125 Egyptian women diagnosed as having invasive breast carcinoma. Associations with clinicopathologic variables and the prognostic markers Bcl-2 and Cyclin D1 were investigated and statistically analyzed. Population difference in breast cancer subtypes was detected, suggesting etiologic and genetic heterogeneity among demographic groups. As reported worldwide, most tumors were luminal A (39.2%), but basal-like and unclassified subtypes had higher proportions among our cohort (16.8% and 16%, respectively), particularly in premenopausal patients (P = .0001), in contrast to postmenopausal African Americans, premenopausal European Americans, and other populations. Her2-overexpressing subtype was the least common subtype (13.65%) among our patients, although it is more common in Asians. Basal-like and unclassified carcinomas were more frequently grade 3 neoplasms (P = .035). Lobular histology was distributed among luminal A, B and unclassified subtypes (P = .006). The highest frequency of nodal positivity was associated with Her2 overexpressing carcinomas (94.1%, P = .0001). Luminal and unclassified carcinomas more likely expressed Bcl-2 (P = .011) and Cyclin D1 (P = .0001), whereas basal and Her2 subtypes had the lowest expression levels. Immunohistochemistry-based subtyping can be helpful in separating breast carcinoma into subtypes that vary in distribution among different populations. These subtypes have distinct clinicopathologic features and diverse prognostication, which may imply different therapeutic options for each subtype.
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PMID:Immunohistochemistry-based subtyping of breast carcinoma in Egyptian women: a clinicopathologic study on 125 patients. 2432 63


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