Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P04626 (erbB-2)
 5,251 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The Her-2/neu oncogene, the second member of the epidermal growth factor (EGF) receptor family, encodes a transmembrane tyrosine kinase receptor. Overexpression of Her-2/neu in approximately 30% of breast cancers is associated with poor overall survival. Recently, we have found that Her-2/neu activates nuclear factor (NF)-kappaB via a phosphatidylinositol 3 kinase (PI3-K)-Akt kinase signaling pathway in mouse mammary tumor virus (MMTV)-Her-2/neu NF639 mouse breast cancer cells. Surprisingly, the IkappaB kinase (IKK) kinase complex, implicated in proteasome-mediated degradation of IkappaB-alpha and activation of NF-kappaB via the canonical pathway, was not activated in these cells. Degradation of IkappaB-alpha was mediated via calpain, which in B cells is facilitated by phosphorylation of IkappaB-alpha by the protein kinase CK2. Here, we report that the inhibition of CK2 blocks Her-2/neu-mediated activation of NF-kappaB. NF639 breast cancer cells, stably expressing CK2alpha or CK2alpha' kinase-inactive mutants, displayed decreased NF-kappaB binding and reduced ability to grow in soft agar, as well as increased sensitivity to tumor necrosis factor (TNF)-alpha killing. Similarly, CK2 kinase-inactive subunits inhibited NF-kappaB activity in Hs578T human breast cancer cells, which also display elevated CK2 activity. In NIH 3T3 fibroblasts, which express low basal NF-kappaB and CK2 activities, overexpression of CK2 by retroviral gene delivery led to increased IkappaB-alpha turnover and the induction of classical NF-kappaB (p50/RelA). Thus, CK2 plays an important role in Her-2/neu signaling, promoting IkappaB-alpha degradation and, thereby, NF-kappaB activation. Furthermore, because ectopic CK2 activity appears sufficient to induce NF-kappaB, the elevated CK2 activity observed in many primary human breast cancers likely plays a role in aberrant activation of NF-kappaB and, therefore, represents a potential therapeutic target.
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PMID:Protein kinase CK2 promotes aberrant activation of nuclear factor-kappaB, transformed phenotype, and survival of breast cancer cells. 1243 79

The objective of this study was to evaluate molecular markers involved in mammary tumorigenesis in a canine model that mimics many essential elements of human breast cancer. Thirty mammary gland tumors and control tissues obtained from female dogs were included in the study. We analyzed changes in the expression of markers of hormone and receptor status (estradiol, estrogen receptor; ER and HER-2/neu), hormone metabolism (CYP1A1 and CYP1B1), cell proliferation and survival [proliferating cell nuclear antigen (PCNA), glutathione S-transferase-P (GST-P), nuclear factor-kappaB (NF-kappaB-p50, NF-kappaB-p65), phosphorylated-inhibitor of kappaB-alpha (p-IkappaB-alpha) and IkappaB], apoptosis (Bcl-2, Bax, caspases, Apaf-1, cytochrome-C, and PARP), invasion [matrix metalloproteinases-2 and -9 (MMP-2, MMP-9), tissue inhibitor of matrix metalloproteinase-2 (TIMP-2), and reversion-inducing cysteine-rich protein with Kazal motifs (RECK)], angiogenesis [vascular endothelial growth factor (VEGF)], and epigenetics [DNA methyltransferase (Dnmt-1), histone deacetylase (HDAC-1)] by immunohistochemical localization and Western blot analysis and correlated these with histological grade. The present study provides evidence that increased expression of ER, HER-2/neu, estradiol, and its metabolizing enzymes, as well as proteins involved in cell proliferation, apoptosis evasion, invasion, and angiogenesis may confer a selective growth advantage to canine mammary tumors. To our knowledge this is the first report on the hallmark capabilities of canine mammary tumors, which lends credence to the view that the dog is a valuable model for human breast cancer studies.
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PMID:Evaluation of molecular markers in canine mammary tumors: correlation with histological grading. 2022 57