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)

ErbB2 (HER2/neu) is overexpressed in about 25-30% of breast malignancies, and up-regulation of ErbB2 in breast cancer patients is associated with poor prognosis. It is known that the carboxyl terminus of heat shock cognate 70 interacting protein (CHIP) efficiently down-regulates ErbB2 in vitro. Human tumourous imaginal disc 1 (Tid1, DnaJa3), a co-chaperone of heat shock protein 70 (Hsp70), also suppresses ErbB2 expression in breast cancer cell lines. However, the intracellular interactions among Tid1, CHIP, and ErbB2 remain elusive, and the utilization of Tid1 and CHIP as breast cancer biomarkers has never been proposed. Herein, we analysed the expression and correlations among Tid1, CHIP, and ErbB2 in a total of 183 breast cancer histology sections, including 30 fresh tissue specimens, using immunohistochemistry (IHC) and immunoblotting assay. A computerized image analysis system was used for IHC scoring and determining relative immunoblot intensity. The immunohistochemical expression of Tid1 and CHIP were positively correlated with each other but were both inversely correlated to that of ErbB2. Odds ratio analyses showed that lower expression of Tid1 has a relatively higher risk of unfavourable tumour grade, later pathological stage, larger tumour size, and microscopic features of a more malignant histology including lymphovascular invasion, stromal inflammatory response, and tumour necrosis. Expression of CHIP displayed similar characteristics. Furthermore, expression of Tid1 and/or CHIP increases patients' 10-year overall and disease-free survival rate. Empirically, we also demonstrated that Tid1, CHIP, and ErbB2 interacted with each other through immunofluorescence or co-immunoprecipitation analyses. Functionally, Tid1 and CHIP acted synergistically to degrade ErbB2 in vitro. Conversely, Tid1 cannot compensate for the loss of proteolytic function noted in CHIP mutations for degradation of ErbB2. Overall, our data suggest that Tid1 and CHIP play pivotal roles in affecting the levels of ErbB2 protein, and that both are significant prognostic indicators of breast cancer patient survival.
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PMID:Tid1, CHIP and ErbB2 interactions and their prognostic implications for breast cancer patients. 2171 Jun 89

Activated p53 is necessary for tumor suppression. Homeodomain-interacting protein kinase-2 (HIPK2) is a positive regulator of functional p53. HIPK2 modulates wild-type p53 activity toward proapoptotic transcription and tumor suppression by the phosphorylation of serine 46. Knock-down of HIPK2 interferes with tumor suppression and sensitivity to chemotherapy. Combined administration of adriamycin and zinc restores activity of misfolded p53 and enables the induction of its proapoptotic and tumor suppressor functions in vitro and in vivo. We therefore looked for a cancer model where HIPK2 expression is low. MMTV-neu transgenic mice overexpressing HER2/neu, develop mammary tumors at puberty with a long latency, showing very low expression of HIPK2. Here we show that whereas these tumors are resistant to adriamycin treatment, a combination of adriamycin and zinc suppresses tumor growth in vivo in these mice, an effect evidenced by the histological features of the mammary tumors. The combined treatment of adriamycin and zinc also restores wild-type p53 conformation and induces proapoptotic transcription activity. These findings may open up new possibilities for the treatment of human cancers via the combination of zinc with chemotherapeutic agents, for a selected group of patients expressing low levels of HIPK2, with an intact p53. In addition, HIPK2 may serve as a new biomarker for tumor aggressiveness.
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PMID:Zinc supplementation augments in vivo antitumor effect of chemotherapy by restoring p53 function. 2193 19

ErbB2 (v-erb-b2 avian erythroblastic leukemia viral oncogene homolog 2), a receptor tyrosine kinase of the ErbB family, is overexpressed in around 25% of breast cancers. In addition to forming a heterodimer with other ErbB receptors in response to ligand stimulation, ErbB2 can be activated in a ligand-independent manner. We report here that Erbin, an ErbB2-interacting protein that was thought to act as an antitumor factor, is specifically expressed in mammary luminal epithelial cells and facilitates ErbB2-dependent proliferation of breast cancer cells and tumorigenesis in MMTV-neu transgenic mice. Disruption of their interaction decreases ErbB2-dependent proliferation, and deletion of the PDZ domain in Erbin hinders ErbB2-dependent tumor development in MMTV-neu mice. Mechanistically, Erbin forms a complex with ErbB2, promotes its interaction with the chaperon protein HSP90, and thus prevents its degradation. Finally, ErbB2 and Erbin expression correlates in human breast tumor tissues. Together, these observations establish Erbin as an ErbB2 regulator for breast tumor formation and progression.
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PMID:Role of Erbin in ErbB2-dependent breast tumor growth. 2528 31