Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
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It has become important to accurately evaluate the status of HER-2/neu in invasive breast cancer, especially when one is considering the use of anti-HER-2 monoclonal antibody therapy (Trastuzumab). Almost one third of invasive breast carcinomas overexpress the HER-2/neu protein, so the use of the anti-HER-2/neu monoclonal antibody Herceptin (trastuzumab) to block the protein has become important in the management of and in prolonging the survival for patients with metastatic breast cancer. The effectiveness of this therapy is dependent on accurately evaluating the HER-2 status in these tumors, which can be done either by studying the expression of HER-2 protein by immunohistochemistry (IHC) or by evaluating HER-2 gene amplification by fluorescent in situ hybridization (FISH). Since interobserver variability may occur in manually grading HER-2 protein expression by IHC, the aim of this study was to compare the HER-2/neu expression by IHC using a computer-based image analysis system with that of the gene amplification by FISH. Formalin-fixed paraffin-embedded archival tissue from 108 primary infiltrating ductal carcinomas were immunostained using the HercepTest (DAKO). To reduce interobserver variability, membrane staining was evaluated using the Automated Cellular Imaging System (ACIS) by ChromaVision, and the cases were divided into four groups: group 1 (n=23) with HER-2/neu expression ACIS score less than or equal to 1.5; group 2 (n=17) with a score ranging from 1.6 to 1.9; group 3 (n=46) with a score 2.0 to 2.5; and group 4 (n=22) with a score greater than or equal to 2.6. FISH was performed on all of the 108 cases using the PathVysion HER-2/neu DNA probe kit from Vysis Inc. All cases were also manually reviewed and graded as negative, 1+, 2+, and 3+ according to the DAKO HercepTest grading scheme. Cases with negative and 1+immunostaining were considered as HER-2 not overexpressed, and cases with 2+ and 3+ staining were classified as showing HER-2 overexpression. In group 1, 1 of 23 (4%), in group 2, 2 of 17 (12%), in group 3, 5 of 46 (11%), and in group 4, 19 of 22 (86%) cases showed gene amplification by FISH. Furthermore, in group 4 all 15 (100%) cases with an ACIS score of 3 or greater were FISH positive. Correlation with manual IHC score and FISH showed that 2 of the 23 (9%) IHC negative (0 and 1+) cases and 25 of the 85 (29%) IHC positive (2+ and 3+) cases showed gene amplification by FISH. This study shows that the amplification of the HER-2/neu gene correlates better with overexpression of the HER-2/neu protein by IHC when the score is either less than 1.5 or greater than 2.6 by ACIS. Therefore, FISH may be useful to better evaluate HER-2/neu status in breast cancer in cases where the ACIS score by immunohistochemistry is 1.6 to 2.5, and since the correlation is so good, FISH may not be needed for HER-2 evaluation in cases with ACIS scores less than 1.5 and greater than 2.6.
Appl Immunohistochem Mol Morphol 2006 Jun
PMID:HER-2 status in breast cancer: correlation of gene amplification by FISH with immunohistochemistry expression using advanced cellular imaging system. 1678 79

Oligonucleotides containing CpG motifs and immunomodulatory oligonucleotides (IMO) containing a synthetic immunostimulatory dinucleotide and a novel DNA structure have been suggested to have potential for the treatment of various human diseases. In the present study, a newly designed IMO was evaluated in several models of human (MCF-7 and BT474 xenograft) and murine (4T1 syngeneic) breast cancer. Pharmacokinetics studies of the IMO administered by s.c., i.v., p.o., or i.p. routes were also accomplished. The IMO was widely distributed to various tissues by all four routes, with s.c. administration yielding the highest concentration in tumor tissue. The IMO inhibited the growth of tumors in all three models of breast cancer, with the lowest dose of the IMO inhibiting MCF-7 xenograft tumor growth by >40%. Combining the IMO with the anticancer antibody, Herceptin, led to potent antitumor effects, resulting in >96% inhibition of tumor growth. The IMO also exerted in vitro antitumor activity, as measured by cell growth, apoptosis, and proliferation assays in the presence of Lipofectin. This is the first report of the pharmacokinetics of this agent in normal and tumor-bearing mice. Based on the present results, we believe that the IMO is a good candidate for clinical development for breast cancer therapy used either alone or in combination with conventional cancer therapeutic agents.
Mol Cancer Ther 2006 Aug
PMID:Immunomodulatory oligonucleotides as novel therapy for breast cancer: pharmacokinetics, in vitro and in vivo anticancer activity, and potentiation of antibody therapy. 1692 32

Rapamycin and its analogues are being tested as new antitumor agents. Rapamycin binds to FKBP-12 and this complex inhibits the activity of FRAP/mammalian target of rapamycin, which leads to dephosphorylation of 4EBP1 and p70 S6 kinase, resulting in blockade of translation initiation. We have found that RAP inhibits the growth of HER-2-overexpressing breast cancer cells. The phosphorylation of mammalian target of rapamycin, p70 S6 kinase, and 4EBP1 is inhibited by rapamycin and cells are arrested in the G1 phase, as determined by growth assays, fluorescence-activated cell sorting analysis, and bromodeoxyuridine incorporation studies. Rapamycin causes down-regulation of cyclin D3 protein, retinoblastoma hypophosphorylation, loss of cyclin-dependent kinase (cdk) 4, cdk6, and cdk2 activity. The half-life of cyclin D3 protein decreases after rapamycin treatment, but not its synthesis, whereas the synthesis or half-life of cyclin D1 protein is not affected by the drug. Additionally, rapamycin caused accumulation of ubiquitinated forms of cyclin D3 protein, proteasome inhibitors blocked the effect of rapamycin on cyclin D3, and rapamycin stimulated the activity of the proteasome, showing that the effect of rapamycin on cyclin D3 is proteasome proteolysis dependent. This effect depends on the activity of HER-2 because Herceptin, a neutralizing antibody against HER-2, is able to block both the induction of proteasome activity and the cyclin D3 down-regulation due to rapamycin. Furthermore, inhibition of HER-2 gene expression by using small interfering RNA blocked the rapamycin effects on cyclin D3. These data indicate that rapamycin causes a G1 arrest in HER-2-overexpressing breast cancer cells that is associated with a differential destabilization and subsequent down-regulation of cyclin D3 protein.
Mol Cancer Ther 2006 Sep
PMID:Cyclin D3 is down-regulated by rapamycin in HER-2-overexpressing breast cancer cells. 1698 50

Identification of shared tumor-specific targets is useful in developing broadly applicable therapies. In a study designed to identify genes up-regulated in breast cancer, a cDNA clone corresponding to a novel gene C35 (C17orf37) was selected by representational difference analysis of tumor and normal human mammary cell lines. Abundant expression of C35 transcript in tumors was confirmed by Northern blot and real-time PCR. The C35 gene is located on chromosome 17q12, 505 nucleotides from the 3' end of the ERBB2 oncogene, the antigenic target for trastuzumab (Herceptin) therapy. The chromosomal arrangement of the genes encoding C35 and ERBB2 is tail to tail. An open reading frame encodes a 12-kDa protein of unknown function. Immunohistochemical analysis detected robust and frequent expression of C35 protein, including 32% of grade 1 and 66% of grades 2 and 3 infiltrating ductal carcinomas of the breast (in contrast to 20% overexpressing HER-2/neu), 38% of infiltrating lobular carcinoma (typically HER-2/neu negative), as well as tumors arising in other tissues. C35 was not detected in 38 different normal human tissues, except Leydig cells in the testes and trace levels in a small percentage of normal breast tissue samples. The distinct and favorable expression profile of C35 spanning early through late stages of disease, including high frequency of overexpression in various breast carcinoma, abundant expression in distant metastases, and either absence or low level expression in normal human tissues, warrants further investigation of the relevance of C35 as a biomarker and/or a target for development of broadly applicable cancer-specific therapies.
Mol Cancer Ther 2006 Nov
PMID:C35 (C17orf37) is a novel tumor biomarker abundantly expressed in breast cancer. 1712 40

Resistance of ovarian clear cell carcinoma (CCC) to platinum-based chemotherapy is associated with poor prognosis, and an effective treatment for advanced disease is urgently needed. HER2/neu is up-regulated more often in CCC than in other histologic types of epithelial ovarian cancer. The purpose of this study was to assess possible treatment for ovarian CCC with the anti-HER2 antibody trastuzumab or human adenovirus type 5 E1A. We treated 10 CCC cell lines with trastuzumab or E1A and assessed cell viability, proliferation, and colony formation and the expression of HER2 and wild-type p53 proteins and molecules downstream of those signaling pathways. HER2 protein was detected at various levels in all 10 cell lines by Western blotting and in 5 CCC cell lines by immunohistochemical staining; HER2 gene amplification was detected (by fluorescence in situ hybridization) in only one cell line (RMG-I). Trastuzumab did not inhibit proliferation in any of the four CCC cell lines tested (RMG-I, SKOV-2, OVTOKO, and OVSAYO). However, transfection with E1A (as compared with control vectors) reduced colony formation in all 10 CCC cell lines regardless of HER2 expression level. Infection of RMG-I and SMOV-2 cells with an adenoviral vector encoding E1A led to significant (P < 0.05) suppression of proliferation and enhancement of cell death; this effect required stabilization of p53 (but not p73) protein and was associated with the up-regulation of Bax and the cleavage of caspase-9. Other mechanisms, such as p53-independent apoptosis, may also be involved in E1A-mediated cell death in CCC. Finally, treatment with E1A prolonged survival in a CCC xenograft model (P < 0.001). E1A gene therapy, because of its ability to stabilize wild-type p53, is worth exploring as a treatment modality for women with ovarian CCC, which typically expresses wild-type p53.
Mol Cancer Ther 2007 Jan
PMID:Adenovirus type 5 E1A gene therapy for ovarian clear cell carcinoma: a potential treatment strategy. 1721 36

The use of radionuclide molecular imaging enables the selection of patients for treatment using molecular medicine. Preclinical studies have demonstrated that a novel low-molecular-weight affinity ligand, Affibody molecule Z(HER2:342) can image the expression of HER2 with high sensitivity and specificity in tumour xenografts and has a potential for the selection of patients for treatment using Herceptin or other anti-HER2 medicine. In this study, we performed a comparative evaluation of two possible linkers for radioiodination of the Affibody molecule Z(HER2:342), 4-iodobenzoate (PIB) and [4-isothiocyanatobenzyl)-amino]-undecahydro-closo-dodecaborate (DABI). It was shown that the use of DABI makes it possible to obtain radioiodinated Z(HER2:342) with preserved capacity for selective binding to HER2-expressing cells. There was no difference between 125I-PIB-Z(HER2:342) and 125I-DABI-Z(HER2:342) in cellular retention of radioactivity after interrupted incubation with radiolabelled Affibody ligands. In vivo, the biodistribution of 125I-PIB-Z(HER2:342) was characterized by a high tumour uptake at 4 h pi (12.7+/-4.6% IA/g) and a quick clearance from blood and normal organs. The tumour uptake of 125I-DABI-Z(HER2:342) was appreciably lower (2.7+/-1.2% IA/g), and a high uptake of this conjugate in the liver was observed. A gamma-camera experiment (at 6 h pi) demonstrated that the use of 125I-PIB-Z(HER2:342) provided a much better contrast of imaging HER2-expressing xenografts than the use of 125I-DABI-Z(HER2:342). In conclusion, 125I-PIB-Z(HER2:342) is superior to 125I-DABI-Z(HER2:342) as an agent for imaging HER2 expression in vivo.
Int J Mol Med 2007 Mar
PMID:Comparison of benzoate- and dodecaborate-based linkers for attachment of radioiodine to HER2-targeting Affibody ligand. 1727 98

Nuclear factor-kappaB (NF-kappaB), a transcription factor with pleotropic effects, is a downstream mediator of growth signaling in estrogen receptor (ER)-negative and erbB family particularly erbB2 (HER-2/neu) receptor-positive cancer. We previously reported activation of NF-kappaB in ER-negative breast cancer cells and breast tumor specimens, but the consequence of inhibiting NF-kappaB activation in this subclass of breast cancer has not been shown. In this study, we investigated the role of NF-kappaB activation by studying the tumorigenic potential of cells expressing genetically manipulated, inducible, dominant-negative inhibitory kappaB kinase (IKK) beta in xenograft tumor model. Conditional inhibition of NF-kappaB activation by the inducible expression of dominant-negative IKKbeta simultaneously blocked cell proliferation, reinstated apoptosis, and dramatically blocked xenograft tumor formation. Secondly, the humanized anti-erbB2 antibody trastuzumab (Herceptin) and the specific IKK inhibitor NF-kappaB essential modifier-binding domain peptide both blocked NF-kappaB activation and cell proliferation and reinstated apoptosis in two ER-negative and erbB2-positive human breast cancer cell lines that are used as representative model systems. Combinations of these two target-specific inhibitors synergistically blocked cell proliferation at concentrations that were singly ineffective. Inhibition of NF-kappaB activation with two other low molecular weight compounds, PS1145 and PS341, which inhibited IKK activity and proteasome-mediated phosphorylated inhibitory kappaB protein degradation, respectively, blocked erbB2-mediated cell growth and reversed antiapoptotic machinery. These results implicate NF-kappaB activation in the tumorigenesis and progression of ER-negative breast cancer. It is postulated that this transcription factor and its activation cascade offer therapeutic targets for erbB2-positive and ER-negative breast cancer.
Mol Cancer Ther 2007 Jul
PMID:Nuclear factor-kappaB activation: a molecular therapeutic target for estrogen receptor-negative and epidermal growth factor receptor family receptor-positive human breast cancer. 1762 Apr 28

Trastuzumab is a recombinant antibody drug that is widely used for the treatment of breast cancer. Despite encouraging clinical results, some cancers are primarily resistant to trastuzumab, and a majority of those initially responding become resistant during prolonged treatment. The mechanisms of trastuzumab resistance have not been fully understood. We examined the role of antibody-dependent cellular cytotoxicity (ADCC) using JIMT-1 cells that are ErbB2 positive but intrinsically resistant to trastuzumab in vitro. Unexpectedly, in experiments mimicking adjuvant therapy of submacroscopic disease in vivo (JIMT-1 cells inoculated s.c. in severe combined immunodeficiency mice), trastuzumab was able to inhibit the outgrowth of macroscopically detectable xenograft tumors for up to 5-7 weeks. The effect is likely to be mediated via ADCC because trastuzumab-F(ab')(2) was ineffective in this model. Moreover, in vitro ADCC reaction of human leukocytes was equally strong against breast cancer cells intrinsically sensitive (SKBR-3) or resistant (JIMT-1) to trastuzumab or even against a subline of JIMT-1 that was established from xenograft tumors growing despite trastuzumab treatment. These results suggest that ADCC may be the predominant mechanism of trastuzumab action on submacroscopic tumor spread. Thus, measuring the ADCC activity of patient's leukocytes against the tumor cells may be a relevant predictor of clinical trastuzumab responsiveness in vivo.
Mol Cancer Ther 2007 Jul
PMID:Trastuzumab causes antibody-dependent cellular cytotoxicity-mediated growth inhibition of submacroscopic JIMT-1 breast cancer xenografts despite intrinsic drug resistance. 1762 Apr 35

In this article, a fluorescence lifetime imaging system for small animals is presented. Data were collected by scanning a region of interest with a measurement head, a linear fiber array with fixed separations between a single source fiber and several detection fibers. The goal was to localize tumors and monitor their progression using specific fluorescent markers. We chose a near-infrared contrast agent, Alexa Fluor 750 (Invitrogen Corp., Carlsbad, CA). Preliminary results show that the fluorescence lifetime for this dye was sensitive to the immediate environment of the fluorophore (in particular, pH), making it a promising candidate for reporting physiologic changes around a fluorophore. To quantify the intrinsic lifetime of deeply embedded fluorophores, we performed phantom experiments to investigate the contribution of photon migration effects on observed lifetime by calculating the fluorescence intensity decay time. A previously proposed theoretical model of migration, based on random walk theory, is also substantiated by new experimental data. The developed experimental system has been used for in vivo mouse imaging with Alexa Fluor 750 contrast agent conjugated to tumor-specific antibodies (trastuzumab [Herceptin]). Three-dimensional mapping of the fluorescence lifetime indicates lower lifetime values in superficial breast cancer tumors in mice.
Mol Imaging
PMID:Fluorescence lifetime imaging system for in vivo studies. 1771 78

Human epidermal growth factor receptor-2 (HER2) and epidermal growth factor receptor (EGFR) heterodimerize to activate mitogenic signaling pathways. We have shown previously, using MCF7 subcloned cell lines with graded levels of HER2 expression, that responsiveness to trastuzumab and AG1478 (an anti-EGFR agent), varied directly with levels of HER2 expression. HER2 and EGFR up-regulate vascular endothelial growth factor (VEGF), a growth factor that promotes angiogenesis and participates in autocrine growth-stimulatory pathways that might be active in vitro. Here, we show that trastuzumab, erlotinib, and bevacizumab, individually and in combination, inhibit cell proliferation in a panel of unrelated human breast cancer cell lines, in proportion to their levels of HER2 expression. The combination of all three drugs provided a greater suppression of growth than any single drug or two-drug combination in the high HER2-expressing cell lines (P < 0.001). Combination index analysis suggested that the effects of these drugs in combination were additive. The pretreatment net level of VEGF production in each cell line was correlated with the level of HER2 expression (r = 0.883, P = 0.016). Trastuzumab and erlotinib each reduced total net VEGF production in all cell lines. Multiparameter flow cytometry studies indicated that erlotinib alone and the triple drug combination produced a prolonged but reversible blockade of cells in G1, but did not increase apoptosis substantially. These studies suggest that the effects of two and three-drug combinations of trastuzumab, erlotinib, and bevacizumab might offer potential therapeutic advantages in HER2-overexpressing breast cancers, although these effects are of low magnitude, and are likely to be transient.
Mol Cancer Ther 2007 Oct
PMID:Response to trastuzumab, erlotinib, and bevacizumab, alone and in combination, is correlated with the level of human epidermal growth factor receptor-2 expression in human breast cancer cell lines. 1793 60


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