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)

We reported previously that 3',4'-didemethylnobiletin (DDMN) is the major metabolite of nobiletin in mouse urine. In this study, we examined DDMN's molecular mechanism of action and its anti-inflammatory and antitumor properties. We demonstrated that topical application of DDMN effectively inhibited 12-O-tetradecanoylphorbol-13-acetate (TPA)-stimulated transcription of inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2 and ornithine decarboxylase (ODC) messenger RNA and protein expression in mouse skin. Pretreatment with DDMN has resulted in the reduction of TPA-induced nuclear translocation of the nuclear factor-kappa B (NF-kappaB) subunit. DDMN also reduced DNA binding by blocking phosphorylation of inhibitor kappaB (IkappaB) alpha and p65 and caused subsequent degradation of IkappaBalpha. DDMN inhibited TPA-induced phosphorylation and nuclear translocation of the signal transducer and activator of transcription 3. Moreover, DDMN suppressed TPA-induced activation of extracellular signal-regulated kinase 1/2, p38 mitogen-activated protein kinase, phosphatidylinositol 3-kinase/Akt and protein kinase C that are upstream of NF-kappaB and activator protien-1. We also found that DDMN significantly inhibited TPA-induced mouse skin inflammation by decreasing inflammatory parameters. Furthermore, DDMN significantly inhibited 7,12-dimethylbenz[a]anthracene/TPA-induced skin tumor formation measured by the tumor multiplicity of papillomas at 20 weeks. Presented data for the first time reveal that DDMN is an effective antitumor agent that functions by downregulating inflammatory iNOS, COX-2 and ODC gene expression in mouse skin. It is suggested that DDMN is a novel functional agent capable of preventing inflammation-associated tumorigenesis.
Carcinogenesis 2008 Dec
PMID:Anti-inflammatory and antitumor promotional effects of a novel urinary metabolite, 3',4'-didemethylnobiletin, derived from nobiletin. 1882 Feb 86

Stromal cell-derived factor 1alpha (SDF-1alpha) (CXCL12) has been observed to enhance tumor angiogenesis. However, the comprehensive role of SDF-1alpha (CXCL12)-CXCR4 interaction, exerted during angiogenesis, has not been well understood. We have previously demonstrated that human basal cell carcinoma (BCC) tissues and a BCC cell line (BCC-1/KMC) had significant expression of CXCR4, whose level was higher in invasive than in the non-invasive BCC types. Here, we observed that human BCC tissues with high expression levels of CXCR4 had higher vascularity. Further, among the 71 BCCs diagnosed between the years 2004-2005, BCCs with high CXCR4 expression had concomitantly higher microvessel density, as compared with those with low CXCR4 expression (P < 0.001). We found that SDF-1alpha induced angiogenic activity in human BCC cells, both in vitro and in vivo. SDF-1alpha significantly upregulated several angiogenesis-associated genes such as interferon-alpha-inducible protein 27, interleukin (IL)-6, bone morphogenetic protein (BMP)-6, SOCS2 and cyclooxygenase 2 (COX)-2 in human BCC cells. Among them, IL-6 was the earliest and highest upregulated gene whose induction was observed within 6 h of the commencement of SDF-1alpha-CXCR4 interaction. The mechanisms behind the SDF-1alpha-induced time and dose-dependent upregulation of messenger RNA expression and protein secretion of IL-6 were investigated. The transcriptional regulation of IL-6 by SDF-1alpha was mediated by phosphorylation of extracellular signal-related kinase 1/2 and activation of the nuclear factor-kappaB complex. The identification of the angiogenic profiles induced through SDF-1alpha-CXCR4 interactions in human BCC cells may contribute further insights into the mechanisms involved in the angiogenic potential of SDF-1alpha (CXCL12).
Carcinogenesis 2009 Feb
PMID:Stromal cell-derived factor-1alpha (SDF-1alpha/CXCL12)-enhanced angiogenesis of human basal cell carcinoma cells involves ERK1/2-NF-kappaB/interleukin-6 pathway. 1884 99

Pancreatic ductal adenocarcinoma (PDAC) is a leading cause of cancer mortality in Western countries. We have shown previously that four representative human PDAC cell lines were regulated by beta-adrenoreceptors via cyclic adenosine 3',5'-monophosphate (cAMP)-dependent signaling. In the current study, we have tested the hypothesis that nicotine stimulates the growth of PDAC xenografts in nude mice by increasing the systemic levels of the stress neurotransmitters adrenaline and noradrenaline, which are the physiological agonists for beta-adrenoreceptors and that inhibition by gamma-aminobutyric acid (GABA) of the adenylyl cyclase-dependent pathway downstream of adrenoreceptors blocks this effect. The size of xenografts from PDAC cell line Panc-1 was determined 30 days after inoculation of the cancer cells. Stress neurotransmitters in serum as well as cAMP in the cellular fraction of blood and in tumor tissue were assessed by immunoassays. Levels of GABA, its synthesizing enzymes GAD65 and GAD67 and beta-adrenergic signaling proteins in the tumor tissue were determined by western blotting. Nicotine significantly increased the systemic levels of adrenaline, noradrenaline and cAMP while increasing xenograft size and protein levels of cAMP, cyclic AMP response element-binding protein and p-extracellular signal-regulated kinase 1/2 in the tumor tissue. Nicotine additionally reduced the protein levels of both GAD isozymes and GABA in tumor tissue. Treatment with GABA abolished these responses to nicotine and blocked the development of xenografts in mice not exposed to nicotine. These findings suggest that the development and progression of PDAC is subject to significant modulation by stimulatory stress neurotransmitters and inhibitory GABA and that treatment with GABA may be useful for marker-guided cancer intervention of PDAC.
Carcinogenesis 2009 Mar
PMID:Nicotine stimulates pancreatic cancer xenografts by systemic increase in stress neurotransmitters and suppression of the inhibitory neurotransmitter gamma-aminobutyric acid. 1913 43

Pterostilbene, a natural dimethylated analog of resveratrol, is known to have diverse pharmacologic activities including anticancer, anti-inflammation, antioxidant, apoptosis, anti-proliferation and analgesic potential. However, the effects of pterostilbene in preventing invasion of cancer cells have not been studied. Here, we report our finding that pterostilbene significantly suppressed 12-O-tetradecanoylphorbol 13-acetate (TPA)-induced invasion, migration and metastasis of human hepatoma cells (HepG(2) cells). Increase in the enzyme activity, protein and messenger RNA levels of matrix metalloproteinase (MMP)-9 were observed in TPA-treated HepG(2) cells, and these were blocked by pterostilbene. In addition, pterostilbene can inhibit TPA-induced expression of vascular endothelial growth factor, epidermal growth factor and epidermal growth factor receptor. Transient transfection experiments also showed that pterostilbene strongly inhibited TPA-stimulated nuclear factor kappa B (NF-kappaB) and activator protein-1 (AP-1)-dependent transcriptional activity in HepG(2) cells. Moreover, pterostilbene can suppress TPA-induced activation of extracellular signal-regulated kinase 1/2, p38 mitogen-activated protein kinase, c-Jun N-terminal kinases 1/2 and phosphatidylinositol 3-kinase/Akt and protein kinase C that are upstream of NF-kappaB and AP-1. Significant therapeutic effects were further demonstrated in vivo by treating nude mice with pterostilbene (50 and 250 mg/kg intraperitoneally) after inoculation with HepG(2) cells into the tail vein. Presented data reveal that pterostilbene is a novel, effective, anti-metastatic agent that functions by downregulating MMP-9 gene expression.
Carcinogenesis 2009 Jul
PMID:Pterostilbene inhibited tumor invasion via suppressing multiple signal transduction pathways in human hepatocellular carcinoma cells. 1944 59

Activating Ras mutations occur in a large portion of human tumors. Yet, the signaling pathways involved in Ras-induced tumor formation remain incompletely understood. The mitogen-activated protein kinase pathways are among the best studied Ras effector pathways. The p38 mitogen-activated protein kinase isoforms are important regulators of key biological processes including cell proliferation, differentiation, survival, inflammation, senescence, and tumorigenesis. However, the specific in vivo contribution of individual p38 isoforms to skin tumor development has not been elucidated. Recent studies have shown that p38delta, a p38 family member, functions as an important regulator of epidermal keratinocyte differentiation and survival. In the present study, we have assessed the effect of p38delta deficiency on skin tumor development in vivo by subjecting p38delta knockout mice to a two-stage 7,12-dimethylbenz(a)anthracene/12-O-tetradecanoylphorbol-13-acetate chemical skin carcinogenesis protocol. We report that mice lacking p38delta gene exhibited a marked resistance to development of 7,12-dimethylbenz(a)anthracene/12-O-tetradecanoylphorbol-13-acetate-induced skin papillomas, with increased latency and greatly reduced incidence, multiplicity, and size of tumors compared with wild-type mice. Our data suggest that the underlying mechanism for reduced susceptibility to skin carcinogenesis in p38delta-null mice involves a defect in proliferative response associated with aberrant signaling through the two major transformation-promoting pathways: extracellular signal-regulated kinase 1/2-activator protein 1 and signal transducer and activator of transcription 3. These findings strongly suggest an in vivo role for p38delta in promoting cell proliferation and tumor development in epidermis and may have therapeutic implication for skin cancer.
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PMID:p38delta Mitogen-activated protein kinase is essential for skin tumor development in mice. 1945 68

Mucins play a key role in tumorigenesis. MUC15 is a membrane-bound mucin and the MUC15 messenger RNA (mRNA) has been detected in various organs. However, its role in tumor malignancy is still unclear. This study was to investigate the MUC15 expression in colorectal tumors and the role of MUC15 in colon cancer cells. We found that the mRNA expression of MUC15 was significantly higher in 70.8% (51/72) of colorectal tumors compared with their normal counterparts by real-time reverse transcription-polymerase chain reaction. Immunohistochemistry showed that MUC15 expression was increased in 82.6% (43/52) of colorectal tumors. MUC15 overexpression in HCT116 cells enhanced cell proliferation, cell-extracellular matrix adhesion, colony-forming ability and invasion. Furthermore, these effects were significantly reversed by knockdown of MUC15 with short-hairpin RNA. In nude mice models, MUC15 overexpression significantly (P < 0.01) enhanced tumor growth. In addition, treatment of PD98059 significantly (P < 0.01) inhibited MUC15-enhanced invasion, suggesting that the invasion induced by MUC15 in HCT116 cells was primarily mediated through activation of extracellular signal-regulated kinase 1/2. In conclusion, these results suggest that MUC15 is upregulated in colorectal tumors and its expression enhances the oncogenic potential of colon cancer cells.
Carcinogenesis 2009 Aug
PMID:Overexpression of MUC15 activates extracellular signal-regulated kinase 1/2 and promotes the oncogenic potential of human colon cancer cells. 1952 Jul 92

Chronic exposure to UVR is the major etiologic factor in the development of human skin cancers including squamous-cell carcinoma (SCC). We have previously shown that protein Kinase C epsilon (PKCepsilon) transgenic mice on FVB/N background, which overexpress PKCepsilon protein approximately eightfold over endogenous levels in epidermis, exhibit about threefold more sensitivity than wild-type littermates to UVR-induced development of SCC. To determine whether it is PKCepsilon and not the mouse genetic background that determines susceptibility to UVR carcinogenesis, we cross-bred PKCepsilon FVB/N transgenic mice with SKH-1 hairless mice to generate PKCepsilon-overexpressing SKH-1 hairless mice. To evaluate the susceptibility of PKCepsilon SKH-1 hairless transgenic mice to UVR carcinogenesis, the mice were exposed to UVR (1-2 KJ m(-2)) three times weekly from a bank of six kodacel-filtered FS40 sunlamps. As compared with the wild-type hairless mice, PKCepsilon overexpression in SKH-1 hairless mice decreased the latency (12 weeks), whereas it increased the incidence (twofold) and multiplicity (fourfold) of SCC. The SKH hairless transgenic mice were observed to be as sensitive as FVB/N transgenic mice to UVR-induced development of SCC and expression of proliferative markers (proliferating cell nuclear antigen, signal transducers and activators of transcription 3, and extracellular signal-regulated kinase 1/2). The results indicate that PKCepsilon level dictates susceptibility, irrespective of genetic background, to UVR carcinogenesis.
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PMID:PKCepsilon overexpression, irrespective of genetic background, sensitizes skin to UVR-induced development of squamous-cell carcinomas. 2001 Aug 64

The plasma membrane microdomains, lipid rafts, are involved in regulation of cellular functions such as cell survival and adhesion. Cholesterol is a critical component of lipid rafts in terms of their integrity and functions and rafts disruption by cholesterol depletion can induce detachment-induced cell death. Hypoxia inducible factor-1 (HIF-1) alpha is stabilized in hypoxia and transactivates numerous genes required for cellular adaptation to hypoxia. It is also induced by non-hypoxic stimuli and contributes to cell survival. Because hypoxia inhibits cholesterol synthesis and HIF-1alpha plays a role in this process, we here explored a possible connection between lipid rafts and HIF-1alpha. We investigated whether HIF-1alpha is regulated during cholesterol depletion/rafts disruption in A431 cells in normoxic conditions. Methyl-beta cyclodextrin (MbetaCD), which induces cholesterol depletion, upregulated HIF-1alpha even under normoxic conditions and this upregulation required epidermal growth factor receptor (EGFR) and extracellular signal-regulated kinase 1 and 2 activation, but not Akt activation. MbetaCD treatment induced HIF-1alpha upregulation at both the transcriptional and translational levels but not at the posttranslational levels. In addition, MbetaCD robustly induced vascular endothelial growth factor production and stimulated an hypoxia response element-driven luciferase reporter activity under normoxic conditions, indicating that MbetaCD-induced HIF-1alpha is functionally activated. Both EGFR activity and HIF-1alpha expression were higher in the attached cells than in the detached cells after MbetaCD treatment. Furthermore, inhibition of HIF-1alpha by RNA interference accelerated cell detachment, thus increasing cell death, indicating that HIF-1alpha expression attenuates MbetaCD-induced anoikis-like cell death. These data suggest that, depending on cholesterol levels, lipid rafts or membrane fluidity are probably to regulate HIF-1alpha expression in normoxia by modulating rafts protein activities such as EGFR, and this connection between lipid rafts and HIF-1alpha regulation may provide cell survival under membrane-disturbing stress.
Carcinogenesis 2009 Dec
PMID:HIF-1 is induced via EGFR activation and mediates resistance to anoikis-like cell death under lipid rafts/caveolae-disrupting stress. 1978 63

Epidemiologic studies suggest that type 2 diabetes (T2D) increases breast cancer risk and mortality, but there is limited experimental evidence supporting this association. Moreover, there has not been any definition of a pathophysiological pathway that diabetes may use to promote tumorigenesis. In the present study, we used the MKR mouse model of T2D to investigate molecular mechanisms that link T2D to breast cancer development and progression. MKR mice harbor a transgene encoding a dominant-negative, kinase-dead human insulin-like growth factor-I receptor (IGF-IR) that is expressed exclusively in skeletal muscle, where it acts to inactivate endogenous insulin receptor (IR) and IGF-IR. Although lean female MKR mice are insulin resistant and glucose intolerant, displaying accelerated mammary gland development and enhanced phosphorylation of IR/IGF-IR and Akt in mammary tissue, in the context of three different mouse models of breast cancer, these metabolic abnormalities were found to accelerate the development of hyperplastic precancerous lesions. Normal or malignant mammary tissue isolated from these mice exhibited increased phosphorylation of IR/IGF-IR and Akt, whereas extracellular signal-regulated kinase 1/2 phosphorylation was largely unaffected. Tumor-promoting effects of T2D in the models were reversed by pharmacological blockade of IR/IGF-IR signaling by the small-molecule tyrosine kinase inhibitor BMS-536924. Our findings offer compelling experimental evidence that T2D accelerates mammary gland development and carcinogenesis,and that the IR and/or the IGF-IR are major mediators of these effects.
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PMID:Insulin-mediated acceleration of breast cancer development and progression in a nonobese model of type 2 diabetes. 2006 49

Phosphorylation of eukaryotic translation initiation factor 2 alpha (eIF2alpha) is a critical convergence point of the integrated stress response (ISR), which supports eukaryotic cellular adaptation to diverse stressful conditions, including the endoplasmic reticulum (ER) stress by global protein translational arrest and induction of numerous stress-triggered cytoprotective genes. Challenge with non-steroidal anti-inflammatory drug (NSAID) leads to ER perturbation that may sensitize cancer cells to drug-induced apoptosis. Here, we examined the ER stress signals in the context of NSAID exposure and the induction of the critical tumor suppressor, NSAID-activated gene 1 (NAG-1), in the epithelial cancer cells. Sulindac sulfide, the active sulindac metabolite, was shown to trigger the ISRs via eIF2alpha kinase such as RNA-dependent protein kinase-related endoplasmic reticulum kinase (PERK) and RNA-dependent protein kinase (PKR). ER stress markers such as glucose-regulated protein 78 (GRP78), C/EBP homologous protein (CHOP) and activating transcription factor (ATF)-3 were enhanced by sulindac sulfide in colon cancer cells. In these cells, the PERK-activated ATF3-CHOP signaling pathway mediated the gene expression of pro-apoptotic NAG-1- and NSAID-induced apoptosis. In contrast, PKR protein was not involved in the signaling cascade for the gene expression of CHOP-linked NAG-1. Instead, PKR mediated activation of pro-survival extracellular signal-regulated kinase 1/2 (ERK1/2) signaling pathway, which was enhanced by NAG-1 suppression in response to cytotoxic sulindac sulfide exposure. PKR-ERK1/2 activation may thus contribute to the defensive cellular response to cytotoxic NSAIDs while drug-mediated ER stress triggers the pro-apoptotic NAG-1 production in human colon cancer cells.
Carcinogenesis 2010 Apr
PMID:The integrated stress response-associated signals modulates intestinal tumor cell growth by NSAID-activated gene 1 (NAG-1/MIC-1/PTGF-beta). 2013 18


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