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

The presence of frequent methylation of CpG islands (CGIs), designated as the CpG island methylator phenotype in some cancers, is associated with distinct clinicopathological characteristics, including gene amplification, in individual tumor types. Amplification of HER2 in human breast cancers is an important prognostic and therapeutic target, but an association between HER2 amplification and frequent CGI methylation is unknown. To clarify the association, we here quantified methylation levels of promoter CGIs of 11 genes, which are unlikely to confer growth advantage to cells, in 63 human breast cancers. The number of methylated genes in a cancer did not obey a bimodal distribution, and the 63 cancers were classified into those with frequent methylation (n = 16), moderate methylation (n = 26) and no methylation (n = 21). The incidence of HER2 amplification was significantly higher in the cancers with frequent methylation (11 of 16) than in those with no methylation (2 of 21, P = 0.001). Also, the number of methylated genes correlated with the degree of HER2 amplification (r = 0.411, P = 0.002). Correlation analysis with clinicopathological characteristics and methylation of CDKN2A, BRCA1 and CDH1 revealed that frequent methylation had significant correlation with higher nuclear grades (P = 0.001). These showed that frequent methylation had a strong association with HER2 amplification in breast cancers and suggested that frequent methylation can be a determinant of various characteristics in a fraction of human breast cancers.
Carcinogenesis 2009 Mar
PMID:Association between frequent CpG island methylation and HER2 amplification in human breast cancers. 1916 84

There have been reports showing a protective role of aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) against gastrointestinal cancers. E-cadherin (CDH1) is an adhesion molecule involved in tumour invasion/metastasis. Silencing of CDH1 by promoter CpG island methylation was shown in gastric cancer, precancerous lesion, and Helicobacter pylori-infected chronic gastritis. We investigated the methylation status of CDH1 in noncancerous gastric mucosa in chronic aspirin user, and assessed its effect on methylation-associated carcinogenesis. Gastric mucosa samples from antrum were obtained from 217 cancer-free subjects, including 37 chronic aspirin users and 180 subjects with no history of chronic or occasional intake of aspirin. Methylation-specific polymerase chain reaction (PCR), i.e., MSP, was performed for CDH1 gene promoter. In all 217 subjects, CDH1 methylation was detected for 69 subjects (31.7%). CDH1 methylation more frequently occurred in H. pylori-infection-positive subjects (P < 0.0001), while chronic aspirin users had a significantly lower risk of CDH1 methylation [nonuser versus user 36.1% versus 10.8%; odds ratio (OR) = 0.21, 95% confidence interval (CI) = 0.07-0.63, P = 0.005]. Logistic regression analysis showed that chronic aspirin use was the independent factor for lower risk of CDH1 methylation (adjusted OR = 0.21, 95%CI = 0.07-0.66, P = 0.008). Chronic aspirin use was associated with lower risk of CDH1 methylation in H. pylori-positive subjects (nonuser versus user 49.5% versus 19.0%; OR = 0.24, 95%CI = 0.08-0.76, P = 0.01). Similar trend was also found in H. pylori-negative subjects (P = 0.07). No association was found between CDH1 methylation status, and duration and dose of aspirin. Our data suggest that chronic aspirin use is associated with reduced risk of CDH1 methylation in human gastric mucosa. Aspirin may have suppressive role against methylation-related gastric carcinogenesis.
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PMID:Chronic aspirin use suppresses CDH1 methylation in human gastric mucosa. 1918 24

The importance of loss of the cell-cell adhesion molecule E-cadherin (encoded by CDH1) to tumor progression is well established. However, CDH1 germ-line mutations predispose to the cancer susceptibility syndrome hereditary diffuse gastric cancer (HDGC), suggesting a role for E-cadherin in tumor initiation. The earliest indications of cancer in the stomachs of CDH1 mutation carriers are microscopic foci of intramucosal signet-ring cell carcinoma (SRCC; designated "eHDGC"). Here, we used N-methyl-N-nitrosourea (MNU) to promote gastric carcinogenesis in wild-type (wt) and cdh1(+/-) mice. MNU induced a variety of gastric tumors; however, intramucosal SRCC developed with an 11 times higher incidence in cdh1(+/-) mice compared with wt mice. The murine SRCC resembled the human eHDGCs in that they were hypoproliferative, lacked nuclear beta-catenin accumulation, and had reduced membrane localization of E-cadherin and its interacting junctional proteins. The down-regulation of E-cadherin in the murine SRCCs confirmed the importance of the second CDH1 hit to the initiation of diffuse gastric cancer. CDH1 promoter hypermethylation has been proposed to be a major second hit in advanced HDGC; however, its contribution to eHDGC was unknown. We thus examined a series of human eHDGC and detected CDH1 promoter methylation in 50% of foci. Promoter methylation was accompanied by reduced wt CDH1 mRNA levels in the foci and had a monoclonal pattern, consistent with an epigenetic initiation of disease. Together, these findings provide compelling evidence for a deficiency in cell-to-cell adhesion being sufficient to initiate diffuse gastric cancer in the absence of hyperproliferation and beta-catenin activation.
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PMID:E-cadherin deficiency initiates gastric signet-ring cell carcinoma in mice and man. 1922 45

Cell-cell adhesion plays a critical role in the establishment and maintenance of cell polarity and cell society. Reduced cell-cell adhesiveness allows cancer cells to disobey the social order, resulting in destruction of the histological structure, the morphological hallmark of malignant tumors. Morbidity in most cancer patients is not due to primary cancer but to metastatic disease. Thus, understanding the progression of tumors to metastatic state and the changes that take place in highly aggressive cells is important in the development of novel approaches to the diagnosis and treatment of progressive malignancies. Cell adhesion molecules are implicated in human carcinogenesis. E-cadherin is a calcium-dependent cell adhesion molecule the intact function of which is crucial for the establishment and maintenance of epithelial tissue polarity and structural integrity. The gene encoding E-cadherin (CDH1, on chromosome 16q22.1) was one of the first to be considered as an invasion-suppressor gene. Mutations in CDH1 occur in diffuse type gastric cancer, lobular breast cancer, and endometrial cancer. In human cancers, partial or complete loss of E-cadherin expression correlates with malignancy. Through immunohistochemical analysis it has been assessed the abnormal expressions of E-cadherin in three types of cancer: gastric carcinoma, lobular breast carcinomas and cutaneous melanoma and the correlation with the multistep process of metastasis.
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PMID:Correlation between E-cadherin abnormal expressions in different types of cancer and the process of metastasis. 1929 16

Epithelial-to-mesenchymal transition (EMT) is defined as phenotypic change of epithelial cells into mesenchymal cells. EMT, allowing cellular dissociation from epithelial tissues, plays a key role in invasion and metastasis during carcinogenesis as well as in gastrulation and neurulation during embryogenesis. SNAI1/Snail, SNAI2/Slug, ZEB1/deltaEF1/ZFHX1A, ZEB2/SIP1/ZFHX1B, TWIST1/TWIST, and TWIST2/DERMO1 are representative EMT regulators. ZEB2 represses transcription of CDH1, CLDN4, CCND1, TERT, SFRP1, ALPL and miR-200b-200a-429 primary miRNA, and upregulates transcription of mesenchymal markers. ZEB2 is relatively highly expressed in brain corpus callosum and monocytes. ZEB2 is expressed in various types of human tumors, such as breast cancer, gastric cancer, and pancreatic cancer. TGFbeta, TNFalpha, IL1, AKT and hypoxia signals are involved in ZEB2 upregulation and EMT induction; however precise mechanisms of ZEB2 transcription remained unclear. Here, refined integrative genomic analyses of ZEB2 gene were carried out. ZEB2 was co-expressed with POU3F2 (BRN2) and POU3F3 (BRN1) in brain corpus callosum, spinal cord, and fetal brain, whereas ZEB2 was co-expressed with POU2F2 (OCT2) in monocytes. Ets-Smad-binding CGGAGAC motif, bHLH-binding site, and POU/OCT-binding site within proximal promoter region, and NF-kappaB-binding site within intron 2 were completely conserved in human ZEB2, chimpanzee ZEB2, cow ZEB2, mouse Zeb2, rat Zeb2, and chicken zeb2 genes. In addition, HIF1alpha-binding site within proximal promoter region was conserved in mammalian ZEB2 orthologs. Consensus binding site for Hedgehog effector GLI was not identified within or adjacent to the 7-kb regions of human ZEB2 gene. TGFbeta, TNFalpha, IL1, and hypoxia signals directly upregulate ZEB2 to induce EMT, growth arrest, and senescence, whereas Hedgehog signals indirectly upregulate ZEB2 via TGFbeta. Together these facts indicate that ZEB2, occupying the crossroads of inflammation, aging and carcinogenesis, is an important target for drug discovery.
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PMID:Integrative genomic analyses of ZEB2: Transcriptional regulation of ZEB2 based on SMADs, ETS1, HIF1alpha, POU/OCT, and NF-kappaB. 1942 92

There have been reports showing a protective role of nonsteroidal anti-inflammatory drugs (NSAIDs) against gastrointestinal cancers. CpG island hyper methylation (CIHM) of tumor suppressor genes is a major event in carcinogenesis. We investigated the CIHM status of non-cancerous gastric mucosa in chronic NSAID users and non-users and assessed the effect of NSAIDs on CIHM. Gastric mucosa samples were obtained from 51 chronic NSAID users and 180 non-users. CIHM of p14(ARF), p16(INK4a), death-associated protein kinase (DAP-kinase), and E-cadherin (CDH1) genes were determined by methylation-specific PCR. CIHM high was defined as two or more CpG islands methylated. CIHM of p14, p16, CDH1, and CIHM high were lower in chronic NSAID users than in non-users (p14: non-users vs users = 32.2%vs 9.8%, P = 0.003; p16: non-users vs users = 35.0%vs 15.7%, P = 0.02; CDH1: non-users vs users = 36.1%vs 9.8%, P = 0.0009; CIHM high: non-users vs users = 44.4%vs 17.6%, P = 0.0009). NSAID use was also associated with decreased number of CIHM by anova (R = -0.32, P < 0.0001). Multivariate logistic regression analysis with adjustment for sex, age, Helicobacter pylori infection, and NSAID use revealed that NSAID use was inversely correlated with all four CIHM and CIHM high as an independent factor (p14: odds ratio [OR] = 0.17, 95% confidence interval [CI] = 0.06-0.48; p16: OR = 0.32, 95% CI = 0.14-0.75; DAP-kinase: OR = 0.45, 95% CI = 0.22-0.92; CDH1: OR = 0.18, 95% CI = 0.06-0.48; CIHM high: OR = 0.21, 95% CI = 0.09-0.49). No association was found between CIHM status and the duration or dose of NSAIDs. Chronic NSAID use suppresses CIHM in human gastric mucosa. NSAIDs may have a suppressive role against methylation-related gastric carcinogenesis.
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PMID:Chronic nonsteroidal anti-inflammatory drug (NSAID) use suppresses multiple CpG islands hyper methylation (CIHM) of tumor suppressor genes in the human gastric mucosa. 1943 86

The p16(INK4a) tumor suppressor gene is a frequent target of epigenetic inactivation in human cancers, which is an early event in breast carcinogenesis. We describe the existence of a chromatin boundary upstream of the p16 gene that is lost when this gene is aberrantly silenced. We show that the multifunctional protein CTCF associates in the vicinity of this boundary and absence of binding strongly coincides with p16 silencing in multiple types of cancer cells. CTCF binding also correlates with RASSF1A and CDH1 gene activation, and CTCF interaction is absent when these genes are methylated and silenced. Interestingly, defective poly(ADP-ribosyl)ation of CTCF and dissociation from the molecular chaperone Nucleolin occur in p16-silenced cells, abrogating its proper function. Thus, destabilization of specific chromosomal boundaries through aberrant crosstalk between CTCF, poly(ADP-ribosyl)ation, and DNA methylation may be a general mechanism to inactivate tumor suppressor genes and initiate tumorigenesis in numerous forms of human cancers.
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PMID:Epigenetic silencing of the p16(INK4a) tumor suppressor is associated with loss of CTCF binding and a chromatin boundary. 1945 May 26

CpG island hyper-methylation (CIHM) is one of the major events in the gastric carcinogenesis and also occurs in non-neoplastic gastric mucosa. IL-17A, -17F and MIF have a crucial role in the gastric inflammation and carcinogenesis. The CIHM status in the non-cancerous gastric mucosa, in relation to IL-17A (-197G>A, rs2275913), -17F (7488T>C, rs763780) and MIF (-173G>C and -794 tetranucleotide repeats) polymorphisms was investigated. Gastric mucosa samples were obtained from 121 cancer free subjects. CIHM of p14, p16, DAP-kinase and CDH1 genes were determined by methylation-specific polymerase chain reaction (MSP). CIHM high was defined as three or all CpG islands methylated. We employed the PCR-SSCP (multiplex PCR for IL-17A and -17F) method to detect the gene polymorphisms. No association were found between CIHM status and L-17A (-197G>A), IL-17F (7488T>C) and MIF (-173G>C) polymorphisms. MIF 5-CATT repeat carrier (5/5+5/6+5/7) held a significantly higher risk of CIHM of DAP-kinase (OR=2.33, 95% CI=1.07-5.09, p=0.03) and CIHM high (OR=3.63, 95% CI=1.31-10.08, p=0.01). Weak association was also found between the same genotype and increased risk of CIHM of p16 (OR=2.45, 95% CI=0.90-6.68, p=0.08) and CDH1 (OR=2.23, 95% CI=0.94-5.32, p=0.07). 6-CATT repeat carrier (5/6+6/6+6/7) was significantly associated with reduced risk of CIHM of p16 (OR=0.31, 95% CI=0.11-0.90, p=0.03), CDH1 (OR=0.40, 95% CI=0.17-0.98, p=0.045), DAP-kinase (OR=0.37, 95% CI=0.17-0.83, p=0.02) and CIHM high (OR=0.25, 95% CI=0.09-0.74, p=0.01). -7-CATT repeat carrier (6/7+7/7) was weakly associated with reduced risk of CIHM of p16 (OR=0.34, 95% CI=0.10-1.13, p=0.08), DAP-kinase (OR=0.43, 95% CI=0.17-1.06, p=0.07) and CIHM high (OR=0.38, 95%CI=0.12-1.20, p=0.098). The present results provided the first evidence that the genetic polymorphisms MIF polymorphism is associated with CIHM status in the human gastric mucosa. Genetic polymorphisms of MIF-794-CATT repeat may be involved in methylation related carcinogenesis in the stomach.
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PMID:Effect of polymorphisms of IL-17A, -17F and MIF genes on CpG island hyper-methylation (CIHM) in the human gastric mucosa. 1972 98

Aberrant promoter methylation of several known or putative tumor suppressor genes occurs frequently during carcinogenesis, and this epigenetic change has been considered as a potential molecular marker for cancer. We examined the methylation status of nine genes (APC, CDH1, CTNNB1, TIMP3, ESR1, GSTP1, MGMT, THBS1, and TMS1), by quantitative methylation specific PCR. Synchronous preinvasive lesions (atypical ductal hyperplasia and/or ductal carcinoma in situ) and invasive ductal breast carcinoma from 52 patients, together with pure lesions from 24 patients and 12 normal tissues paired to tumor and 20 normal breast distant from tumor were analyzed. Aberrant promoter methylation was detected in both preinvasive and invasive lesions for genes APC, CDH1, CTNNB1, TIMP3, ESR1, and GSTP1. However, hierarchical mixed model and Generalized Estimating Equations model analyses showed that only APC, CDH1, and CTNNB1 promoter regions showed a higher frequency and methylation levels in pathologic samples when compared with normal breast. Whereas APC and CTNNB1 did not show differences in methylation levels or frequencies, CDH1 showed higher methylation levels in invasive tumors as compared with preinvasive lesions (P < 0.04, Mann-Whitney test with permutation correction). The analysis of APC, CDH1, and CTNNB1 methylation status was able to distinguish between normal and pathologic samples with a sensitivity of 67% (95% confidence interval, 60-71%) and a specificity of 75% (95% confidence interval, 69-81%). Our data point to the direct involvement of APC, CDH1, and CTNNB1 promoter methylation in the early stages of breast cancer progression and suggest that they may represent a useful tool for the detection of tumor cells in clinical specimens.
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PMID:Changes in CpG islands promoter methylation patterns during ductal breast carcinoma progression. 1978 64

Squamous cell carcinomas of head and neck (HNSCC) are a result of multiple genetic and epigenetic alterations. Epigenetic inactivation of tumor suppressor genes is an important event in head and neck carcinogenesis. Here we analyzed the promoter methylation of 15 genes (RASSF1A, p16, MGMT, DAPK, RARbeta, MLH1, CDH1, GSTP1, RASSF2, RASSF4, RASSF5, MST1, MST2, LATS1, LATS2) in 54 HNSCC and in matching 23 normal tissues. Methylation of these tumor-related genes (TRG) was significantly more frequent in HNSCC (42%) compared to normal samples (23%; p<0.05). Particularly, methylation of p16 (60%), MGMT (53%), DAPK (67%), RARbeta (75%), MLH1 (69%), CDH1 (43%), RASSF5 and MST1 (96%) was often found in HNSCC. Methylation of RASSF1A (18%), GSTP1 (4%), RASSF4 (13%), MST2 (4%), LATS1 (24%) and LATS2 (8%) was less frequently detected. A trend of increased TRG methylation in more advanced tumor stages and less differentiated HNSCC was observed. Methylation of p16 was significantly higher in poorly differentiated HNSCC (p=0.037) and RASSF5 methylation occurred preferentially in advanced tumor stages (p<0.05). Methylation of RASSF4 was higher in patients with recurrent HNSCC (23%) than patients without relapse (0%; p=0.033). Methylation of TRG in head and neck cancer cell lines was observed at similar frequency as in primary HNSCC. In summary, frequent hyper-methylation of tumor-related genes in HNSCC was detected and this epigenetic silencing event may have an essential role in head and neck carcinogenesis.
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PMID:Frequent promoter hypermethylation of tumor-related genes in head and neck squamous cell carcinoma. 1988 8


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