Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0596263 (carcinogenesis)
 64,820 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

While HER2/neu receptor tyrosine kinase is involved in various malignancies, studies on colorectal adenocarcinoma (CRC) remain controversial. To try to clarify the role played by HER2/neu in CRC, sixty-seven CRC patients in Taiwan were analyzed. For this analysis, we used normalized dual-color fluorescence in situ hybridization (FISH) and Photoshop-aided immunohistochemistry (IHC) between cancers and their autologous non-neoplastic epithelia. The results revealed that HER2/neu status was unrelated to age, sex, location and positive-nodal percentage. Intramucosal carcinomas had earlier HER2/neu protein upregulation than regional stromal invasion within Dukes' A, and had a gene level that had not risen yet. Both gene gains and protein increases were significant in later stages in regards to volumetric progression and nodal-metastatic Dukes' stage. Overall, there were 1.53-fold (gene) and 1.81-fold (protein) increases from non-neoplastic enterocytes to CRCs. The upregulating directions of gene (88%) and protein (88%) presented symmetric agreement. Most CRCs exhibited low to intermediate levels of HER2/neu overexpression with double-minute gene amplicons and cytosolic HER2/neu proteins. Normalized FISH and IHC showed high cubic-regression correlation, especially in Dukes' C. According to the correlation curve, the points with IHC index >2.41 and FISH ratio >1.22 defined the area where gene-amplification-dependent HER2/neu overexpression was present. Eleven (16%) patients had values above the cut-off point (IHC = 2.41 and FISH = 1.22), including 7 (10%) cases in cytosolic and 4 (6%) cases in membranous HER2/neu overexpressions. The results suggest that HER2/neu plays a crucial role in CRC tumorigenicity with gene-amplification-independent transcriptional activations early in the carcinogenesis, and gene-amplification-dependent overexpression later in the advanced stages. This indicates that HER2/neu can be a good biological marker for selecting patients that may improve under therapies that employ adequate HER2/neu-targeting strategies.
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PMID:Clinicopathological relevance of HER2/neu and a related gene-protein cubic regression correlation in colorectal adenocarcinomas in Taiwan. 1575 87

Impaired histone acetylation was recognized to be involved in carcinogenesis. Furthermore, histone deacetylase (HDAC) inhibitors induce differentiation of breast cancer cells and inhibit tumour growth. These results prompted us to study HDAC-1 and -3 expression in breast tumours to establish their potential therapeutic and prognostic significance. HDAC-1 und HDAC-3 protein expression was analyzed immunohistochemically on a tissue microarray (TMA) containing 600 core biopsies from 200 patients. HDAC-1 and -3 expression was correlated to steroid hormone receptor-, Her2/neu- and proliferation status of tumours as well as to overall and disease free survival. Moderate or strong nuclear immunoreactivity for HDAC-1 was observed in 39.8% and for HDAC-3 in 43.9% of breast carcinomas. HDAC-1 and -3 expression correlated significantly with oestrogen and progesterone receptor expression (both p< 0.001). HDAC-1 expression predicted significantly better disease free survival (DFS: p=0.044), in particular, in patients with small tumours of all differentiation types (DFS: p=0.016). Multivariate analysis demonstrated that HDAC-1 is an independent prognostic marker. Our data suggest that evaluation of HDAC-1 protein expression enables a more precise assessment of the prognosis of breast cancer patients. Thus, HDAC-1 expression analysis might be clinically useful to facilitate an individual, risk-directed, adjuvant systemic therapy in breast cancer patients.
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PMID:Histone deacetylase-1 and -3 protein expression in human breast cancer: a tissue microarray analysis. 1577 May 22

We previously showed that a vaccine combining interleukin 12 and allogeneic p185(neu)-positive mammary carcinoma cells completely prevented multifocal mammary carcinogenesis in HER-2/neu transgenic mice. To identify the molecular events responsible for effective tumor prevention and to define the tumor gene expression signature, we used microarrays to analyze the expression profile of mammary tissue of untreated transgenic mice and of vaccine-treated, tumor-free mice at different time points. Mammary tissue from vaccinated mice displayed a gene expression profile different from that of untreated, tumor-bearing mice but similar to that of normal/hyperplastic mammary gland. Comparison of treated and untreated mice at 15 weeks of age revealed up-regulation of genes encoding antibodies, chemokines, gamma-interferon-induced genes and inflammatory molecules, and down-regulation of early genes induced by tumor development. The gene expression signature of HER-2/neu-transformed tumor cells showed modulation of genes promoting proliferation, angiogenesis, migration, invasion, and metastasis and inhibiting apoptosis and immune response. Meta-analysis of microarray data on human breast cancer showed that the signature of tumors arising in murine HER-2/neu transgenic model correctly classified human HER-2/neu-expressing tumors and normal breast tissue. Moreover murine and human HER-2/neu-positive tumors share the signature of basal-like breast cancers. This gene expression analysis reveals the immune events associated with prevention of tumor development and shows that HER-2/neu transgenic mice represent a good model of a poor-prognosis group of human breast tumors.
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PMID:Gene expression analysis of immune-mediated arrest of tumorigenesis in a transgenic mouse model of HER-2/neu-positive basal-like mammary carcinoma. 1579 99

A causative role of the membrane-bound tyrosine kinase ErbB-2 in breast tumorigenesis has been well established. MMTV/neu transgenic mice which overexpress ErbB-2 consistently develop mammary carcinomas with a high incidence. In human breast cancer, ErbB-2 is overexpressed in 25-30 of all cases and is representing a clinical marker of a poor prognosis. Besides to gene amplification, ErbB-2 overexpression has been attributed to transcription factors of the AP-2 family which were shown to control the ErbB-2 gene promoter in cell culture studies. Particularly AP-2alpha and gamma are often coexpressed in ErbB-2-positive breast carcinomas. However, LTRgamma transgenic mice which overexpress AP-2gamma in their mammary epithelium display only a very weak upregulation of the erbB-2 gene and do not develop mammary carcinoma. These findings therefore raise the possibility of functional cooperativity between both genes in breast cancer. To experimentally address the impact of AP-2gammaon ErbB-2-induced breast carcinogenesis we crossed MMTV/neu transgenic mice with LTRgamma transgenic mice and monitored tumor development in bitransgenic female progeny. AP-2gamma overexpression negatively influenced tumor incidence, as reflected by a reduced tumor number and a prolonged tumor latency. Histological analysis revealed three major types of tumors corresponding to different stages of tumor progression. Interestingly, an increased proportion of advanced stage carcinomas was observed in bitransgenic mice. Moreover, the AP-2gamma transgene differentially affected proliferation rates between the different progression stages: proliferation was enhanced at early stages but reduced in advanced stages in comparison to control tumors. Therefore, AP-2gamma while reducing the incidence of mammary tumors is promoting tumor progression.
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PMID:Dual role of AP-2gamma in ErbB-2-induced mammary tumorigenesis. 1583 Jan 41

Clear links have been established between occupational or therapeutic radiation exposure and breast cancer. Tamoxifen chemoprevention following radiation exposure may be able to reduce the risk of developing breast cancer later in life. In order to model carcinogenesis in this setting, an in vivo model of tamoxifen chemoprevention and tamoxifen failure in a radiation-induced rat mammary carcinoma model was characterized. Two hundred and twenty-seven 60-day-old female rats received whole body or sham exposure to ionizing radiation. Thirty days later long-term, continuous, tamoxifen chemoprevention was initiated in half the population and all animals were monitored over three and a half years for the development of mammary tumors. Mammary tumors were surgically removed and carcinomas were histologically identified and characterized. Results showed that tamoxifen chemoprevention decreased the incidence and prolonged the latency of radiation-induced mammary carcinomas. However, many individuals receiving tamoxifen chemoprevention developed their first carcinoma very late in life. These carcinomas shared morphological features distinct from the majority of carcinomas that developed in the absence of tamoxifen chemoprevention. Analyses of cell lines established from these carcinomas and immunohistochemistry of tumor sections revealed that the highest levels of Her2/neu expression were associated with in vivo tamoxifen exposure. Treatment of rat mammary carcinoma cells with an anti-rat Her2/neu monoclonal antibody (MAb 7.16.4) inhibited cell growth and this effect was more pronounced in the presence of tamoxifen. These studies suggest that carcinoma growth driven by the Her2/neu pathway may be associated with tamoxifen chemoprevention failure in the rat mammary carcinoma model. Additionally, strategies combining targeted Her2/neu antibodies, vaccines or drugs with estrogen pathway modification may be more effective in reducing breast cancer chemoprevention failures.
Carcinogenesis 2005 Sep
PMID:Tamoxifen resistance and Her2/neu expression in an aged, irradiated rat breast carcinoma model. 1586 May 8

Estrogen receptors (ERs) regulate the transcription of genes involved in breast cancer cell proliferation, invasion and metastasis. In addition to ligand concentration, phosphorylation and coactivator/corepressor levels control ER-dependent transcription. In this study, we used MCF-7 breast cancer sublines with variable levels of the steroid receptor coactivator 1 (SRC-1) to investigate the importance of coactivator levels in basal and estrogen-inducible expression of SDF-1alpha/CXCL12, cathepsin D and cMyc. Basal expression of SDF-1alpha and cMyc but not of cathepsin D was substantially lower in a MCF-7 subline lacking SRC-1 ((MCF-7/p2) compared with MCF-7 sublines expressing SRC-1 (MCF-7/p1 and LCC2). Although estrogen efficiently induced SDF-1alpha in MCF-7/p1 cells, very little induction of this gene was observed in MCF-7/p2 cells. The absence of SRC-1 had no effect on estrogen-inducible expression cMyc and cathepsin D suggesting that coactivator levels determine the expression of only a subset of estrogen-regulated genes. Introduction of SRC-1, SRC-2/TIF-2 or SRC-3/AIB1 increased basal expression of SDF-1alpha in MCF-7/p2 cells. Consistent with the role of SDF-1alpha in mediating estrogen-induced proliferation, estrogen failed to increase proliferation of MCF-7/p2 cells. In matrigel invasion assays, conditioned media from MCF-7/p1 but not MCF-7/p2 cells increased invasion of cancer cells expressing metastasis-associated genes and CXCR4, the receptor for SDF-1alpha. These results suggest that coactivators control SDF-1alpha expression, which mediates estrogen-induced proliferation and invasion through autocrine and paracrine mechanisms, respectively. These results also provide a molecular explanation for recent observations linking co-overexpression of coactivators and her2/neu with poor prognosis: coactivators increase SDF-1alpha expression whereas her2/neu stabilize CXCR4 protein.
Carcinogenesis 2005 Oct
PMID:The p160 family coactivators regulate breast cancer cell proliferation and invasion through autocrine/paracrine activity of SDF-1alpha/CXCL12. 1591 9

TNF apoptosis-inducing ligand is attracting considerable interest as a potential extrinsic tumor suppressor mechanism, although previous reports have conveyed somewhat contrasting views regarding the likely importance of this pathway. In this study, we provide the first evaluation of spontaneous tumor formation over the life span of TRAIL-deficient mice. Interestingly, >25% of these mice do develop lymphoid malignancies after 500 days of life. TRAIL suppressed the initiation and development of both tumors of lymphoid and stromal origin in the context of the loss of at least one p53 allele. Specific examination of the role of TRAIL in Her2/neu oncogene-driven mammary epithelial cancer revealed no critical role for TRAIL despite the inherent TRAIL sensitivity of such mammary carcinomas. Overall, the data indicate an important function of TRAIL in controlling carcinogenesis, but suggest that further examination of this pathway in epithelial malignancies is warranted.
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PMID:Cutting edge: TRAIL deficiency accelerates hematological malignancies. 1623 43

Matrix metalloproteinases (MMPs), in particular the gelatinases MMP2 and MMP9, are important mediators of tumour invasion and metastasis. We examined whether plasma gelatinase levels could predict lymph node metastasis in breast cancer patients. Further, we investigated the relationship of plasma gelatinase levels with Her2/neu expression, recently acknowledged as an important prognostic factor for recurrence, and with various clinicopathological factors. Preoperative plasma samples from 81 breast cancer patients were collected. Total and active gelatinase levels were measured by enzyme immunoassays and activity assays, respectively. Neither total nor active plasma MMP2 levels correlated with nodal status or with any of the classical clinicopathological factors including histological tumour type, tumour size and grade and hormone receptor status. Patients with Her2/neu overexpressing tumours showed an increase of 27% (P=0.007) in plasma MMP2 activity, but not in total MMP2, compared with patients without overexpression. MMP9 levels, total and active, did not correlate with any of the investigated variables. In contrast to MMP9, total MMP2 levels correlated significantly with active MMP2 levels. In summary, total and active plasma gelatinase levels failed to identify high risk for axillary lymph node metastasis. Active plasma MMP2 was significantly increased in patients with Her2/neu overexpressing tumours, suggesting a role for Her2/neu in the signalling pathways of MMP2 activation in carcinogenesis. However, this increase was too small to be of clinical use. Furthermore, no relationship was found between plasma gelatinase levels, total or active, and any of the clinicopathological prognostic factors.
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PMID:Plasma gelatinase levels in patients with primary breast cancer in relation to axillary lymph node status, Her2/neu expression and other clinicopathological variables. 1632 Jan 12

Prolactin influences mammary development and carcinogenesis through endocrine and autocrine/paracrine mechanisms. In virgin female mice, pro-lactin overexpression under control of a mammary selective nonhormonally responsive promoter, neu-related lipocalin, results in estrogen receptor alpha (ERalpha)-positive and ERalpha-negative adenocarcinomas. However, disease in vivo occurs in the context of dysregulation of multiple pathways. In this study, we investigated the ability of prolactin to modulate carcinogenesis when co-expressed with the potent oncogene transforming growth factor alpha (TGFalpha) in bitransgenic mice. Prolactin and TGFalpha cooperated to reduce dramatically the latency of mammary macrocyst development, the principal lesion type induced by TGFalpha. In combination, prolactin and TGFalpha also increased the incidence and reduced the latency of other preneoplastic lesions and increased cellular turnover in structurally normal alveoli and ducts compared with single transgenic females. Bitransgenic glands contained higher levels of phosphorylated ERK1/2 compared with single TGFalpha transgenic glands, suggesting that this kinase may be a point of signaling crosstalk. Furthermore, transgenic prolactin also reversed the decrease in ERalpha induced by neu-related lipocalin-TGFalpha. Our findings demonstrate that locally produced prolactin can strikingly potentiate the carcinogenic actions of another oncogene and modify ovarian hormone responsiveness, suggesting that prolactin signaling may be a potential therapeutic target.
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PMID:Prolactin potentiates transforming growth factor alpha induction of mammary neoplasia in transgenic mice. 1656 9

Silymarin is a mixture of polyphenolic flavonoids isolated from milk thistle (Silybum marianum) with anticancer activities reported for several organ sites. The present study tested the efficacy of dietary silymarin against mammary carcinogenesis in two rodent models. In the Sprague-Dawley rat model, female rats were fed a purified diet supplemented with none, 0.03, 0.1, 0.3 or 1% (w/w) of silymarin from 21 days of age (DOA) and carcinogenesis was initiated by a single i.p. injection of 1-methyl-1-nitrosourea (MNU) at 51 DOA. Mammary tumor (MT) development was followed till 110 days after carcinogen injection. In the MMTV-neu/HER2 transgenic mouse mammary carcinogenesis model, homozygous transgenic females were fed a purified diet supplemented with none or 0.3% silymarin, either from 28 or 120 DOA and MT development was followed to approximately 300 DOA. The results showed that dietary silymarin increased the plasma concentration of free and total silibinin, a major component of silymarin, in a dose-dependent manner in the rat, but did not decrease either MT incidence or number. Instead silymarin modestly increased the number of MNU-induced MTs in rats. Similarly, silymarin increased MT incidence and multiplicity and non-MTs in the neu-transgenic mice. In cell culture, treatment of human MCF-7 breast cancer cells with serum-achievable concentrations of silymarin in the rodent models stimulated their growth, in part through an estrogen-like activity. Because silymarin is being used in the treatment of liver cirrhosis and a variety of other human ailments, and is sold as a dietary supplement, our findings add a cautionary note to its application in breast cancer prevention.
Carcinogenesis 2006 Sep
PMID:Enhancement of mammary carcinogenesis in two rodent models by silymarin dietary supplements. 1659 42


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