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)

E2F transcription factors, including E2F3, directly modulate expression of EZH2. Recently, overexpression of the EZH2 gene has been implicated in the development of human prostate cancer. In tissue microrarray studies we now show that expression of high levels of nuclear E2F3 occurs in a high proportion (98/147, 67%) of human prostate cancers, but is a rare event in non-neoplastic prostatic epithelium suggesting a role for E2F3 overexpression in prostate carcinogenesis. Patients with prostate cancer exhibiting immunohistochemically detectable nuclear E2F3 expression have poorer overall survival (P=0.0022) and cause-specific survival (P=0.0047) than patients without detectable E2F3 expression. When patients are stratified according to the maximum percentage of E2F3-positive nuclei identified within their prostate cancers (up to 20, 21-40%, etc.), there is an increasingly significant association between E2F3 staining and risk of death both for overall survival (P=0.0014) and for cause-specific survival (P=0.0004). Multivariate analyses select E2F3 expression as an independent factor predicting overall survival (unstratified P=0.0103, stratified P=0.0086) and cause-specific survival (unstratified P=0.0288, stratified P=0.0072). When these results are considered together with published data on EZH2 and on the E2F3 control protein pRB, we conclude that the pRB-E2F3-EZH2 control axis may have a critical role in modulating aggressiveness of individual human prostate cancer.
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PMID:Transcription factor E2F3 overexpressed in prostate cancer independently predicts clinical outcome. 1518 67

Deregulation of apoptosis plays an important role in carcinogenesis, tumor progression, and resistance to chemotherapy. XIAP is considered to be the most potent caspase inhibitor of all known IAP (inhibitor of apoptosis) family members. To explore the relevance of XIAP for progression and prognosis in renal cell carcinomas (RCCs) of the clear-cell type, we analyzed XIAP protein expression in formalin-fixed tissue from 145 clear-cell RCCs by immunohistochemistry. XIAP protein expression was found in 95% of clear-cell RCCs. A significant increase of XIAP expression became evident from well (G1) to poorly (G3) differentiated clear-cell RCCs (P < 0.0001) and from low (pT1) to advanced (pT3) tumor stages (P = 0.0016). Log-rank test showed a significant inverse correlation (P = 0.0174) between XIAP expression and tumor aggressiveness as indicated by patients' survival. Most important, multivariate Cox regression analysis revealed that XIAP expression is an independent prognostic parameter (P = 0.018) in clear-cell RCCs. Our results suggest an important role for XIAP-mediated inhibition of apoptosis during progression of clear-cell RCCs and introduce XIAP expression as a new independent prognostic marker in this tumor type.
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PMID:XIAP expression is an independent prognostic marker in clear-cell renal carcinomas. 1529 70

Whereas accepted models of tumorigenesis exist for genetic lesions, the timing of epigenetic alterations in cancer is not clearly understood. We have analyzed the profile of aberrations in DNA methylation occurring in cells lines and primary tumors of one of the best-characterized mouse carcinogenesis systems, the multistage skin cancer progression model. Initial analysis using high-performance capillary electrophoresis and immunolocalization revealed a loss of genomic 5-methylcytosine associated with the degree of tumor aggressiveness. Paradoxically, this occurs in the context of a growing number of hypermethylated CpG islands of tumor suppressor genes at the most malignant stages of carcinogenesis. We have observed this last phenomenon using two approaches, a candidate gene approach, studying genes with well-known methylation-associated silencing in human tumors, and a mouse cDNA microarray expression analysis after treatment with DNA demethylating drugs. The transition from epithelial to spindle cell morphology is particularly associated with major epigenetic alterations, such as E-cadherin methylation, demethylation of the Snail promoter, and a decrease of the global DNA methylation. Analysis of data obtained from the cDNA microarray strategy led to the identification of new genes that undergo methylation-associated silencing and have growth-inhibitory effects, such as the insulin-like growth factor binding protein-3. Most importantly, all of the above genes were also hypermethylated in human cancer cell lines and primary tumors, underlining the value of the mouse skin carcinogenesis model for the study of aberrant DNA methylation events in cancer cells.
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PMID:A mouse skin multistage carcinogenesis model reflects the aberrant DNA methylation patterns of human tumors. 1531 85

Cyclooxygenase-2 (COX-2) has been known to be related with various types of carcinoma, but we have insufficient knowledge about the association between COX-2 and endometrial cancer. Many have reported a close relationship between p53 expression and a poor prognosis in endometrial cancer, but it is unclear whether p53 is an independent prognostic factor. To clarify these uncertainties, we examined the expressions of COX-2 and p53 in endometrial cancer tissues. The study was carried on 152 endometrial cancer patients who had operation at Seoul National University Hospital. Paraffin-embedded tissue blocks were sectioned and immunostained using monoclonal anti-COX-2 and anti-p53 antibodies. Twenty-seven (17.8%) specimens stained as COX-2 positive. COX-2 positivity was more frequently observed in postmenopausal patients than in premenopausal patients (8.8% versus 25.0%; P = 0.009). However, COX-2 positivity did not show a statistically significant association with any other clinicopathologic characteristic (parity, body mass index, histotype, International Federation of Gynecology and Obstetrics stage, grade, lymph node metastasis, deep myometrial invasion, or p53 overexpression). Thirty-one (20.4%) specimens showed p53 overexpression and this was significantly correlated with an advanced stage (P = 0.001), poor differentiation (P < 0.001), lymph node metastasis (P = 0.012), and deep myometrial invasion (P < 0.001). Multivariate Cox regression analysis showed that advanced stage was an independent prognostic factor of survival, but p53 overexpression was not. COX-2 may be associated with endometrial cancer carcinogenesis during the postmenopausal period but not with tumor aggressiveness and p53 overexpression. The p53 overexpression was found to be strongly associated with endometrial cancer aggressiveness.
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PMID:Cyclooxygenase-2 and p53 expressions in endometrial cancer. 1534 58

Barrett's esophagus is an alteration of the esophageal epithelium, regardless of length, evidenced by endoscopic examination (protrusion of the gastric mucosa into the esophagus in the shape of a flame) and confirmed by histological examination of the bioptic samples (intestinal metaplasia with mucosecretory cells). It develops following long-term gastro-esophageal reflux (GER). The documented risk factors are: long-term GER (duration more than 5 years), age over 50 years, male sex, Caucasian race, aggressiveness of the refluxed material, individual susceptibility of the esophageal mucosa to the refluxed material. The carcinogenic risk is 30 times higher than in the general population. Treatment targets the acid reflux, with proton pump inhibitors (PPI), prevention of carcinogenesis with cyclooxygenase 2 inhibitors, ablation of the metaplastic area by laser, plasma-argon mucosectomy, or photodynamic therapy and antireflux surgery.
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PMID:Barrett's Esophagus. 1547 May 35

Cancer is a heterogeneous disease in most respects, including its cellularity, different genetic alterations, and diverse clinical behaviors. Traditional molecular analyses are reductionist, assessing only 1 or a few genes at a time, thus working with a biologic model too specific and limited to confront a process whose clinical outcome is likely to be governed by the combined influence of many genes. The potential of functional genomics is enormous, because for each experiment, thousands of relevant observations can be made simultaneously. Accordingly, DNA array, like other high-throughput technologies, might catalyze and ultimately accelerate the development of knowledge in tumor cell biology. Although in its infancy, the implementation of DNA array technology in cancer research has already provided investigators with novel data and intriguing new hypotheses on the molecular cascade leading to carcinogenesis, tumor aggressiveness, and sensitivity to antiblastic agents. Given the revolutionary implications that the use of this technology might have in the clinical management of patients with cancer, principles of DNA array-based tumor gene profiling need to be clearly understood for the data to be correctly interpreted and appreciated. In the present work, we discuss the technical features characterizing this powerful laboratory tool and review the applications so far described in the field of oncology.
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PMID:DNA array-based gene profiling: from surgical specimen to the molecular portrait of cancer. 1562 87

Galectins are a large family of proteins which bind galactoside-containing glycans. Their role in cancer seems to be important since members of the family may mediate cell adhesion and modulate cell growth. Galectin-3 (Gal-3) is expressed in the nucleus, in the cytoplasm and on the cell surface, and can also be secreted into the extracellular matrix. A series of experimental and clinical data have been reported which indicate that Gal-3 may play a putative role in carcinogenesis, cancer progression and the process of metastasis. To study the possible correlation between Gal-3 expression and malignant potential in primary melanoma lesions, we conducted an immunohistochemical study with monoclonal anti-Gal-3 antibody in a series of primary and metastatic melanoma lesions as well as benign skin pigmented lesions. We also developed a xenograft melanoma model in nude mice with two melanoma cell lines (ATCC G-361 and ATCC HT-144) and assessed staining with the Gal-3 antibody in the xenografts and the metastases. The expression of anti-Gal-3 staining was determined semiquantitatively. The expression of Gal-3 was higher in thin primary melanoma lesions than in benign pigmented skin lesions or metastases and seemed to correlate inversely with the aggressiveness as estimated by the Breslow index which is recognized as the main prognostic factor in melanoma. We propose Gal-3 expression in melanoma as a diagnostic and/or a prognostic parameter and suggest that further studies of such a role for Gal-3 are warranted.
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PMID:Expression of galectin-3 in primary and metastatic melanoma: immunohistochemical studies on human lesions and nude mice xenograft tumors. 1564 76

P-Cadherin/CDH3 belongs to the family of classic cadherins that are engaged in various cellular activities including motility, invasion, and signaling of tumor cells, in addition to cell adhesion. However, the biological roles of P-cadherin itself are not fully characterized. Based on information derived from a previous genome-wide cDNA microarray analysis of microdissected pancreatic ductal adenocarcinoma (PDAC), we focused on P-cadherin as one of the genes most strongly overexpressed in the great majority of PDACs. To investigate the consequences of overexpression of P-cadherin in terms of pancreatic carcinogenesis and tumor progression, we used a P-cadherin-deficient PDAC cell line, Panc-1, to construct a cell line (Panc1-CDH3) that stably overexpressed P-cadherin. Induction of P-cadherin in Panc1-CDH3 increased the motility of the cancer cells, but a blocking antibody against P-cadherin suppressed the motility in vitro. Overexpression of P-cadherin was strongly associated with cytoplasmic accumulation of one of the catenins, p120ctn, and cadherin switching in PDAC cells. Moreover, P-cadherin-dependent activation of cell motility was associated with activation of Rho GTPases, Rac1 and Cdc42, through accumulation of p120ctn in cytoplasm and cadherin switching. These findings suggest that overexpression of P-cadherin is likely to be related to the biological aggressiveness of PDACs; blocking of P-cadherin activity or its associated signaling could be a novel therapeutic approach for treatment of aggressive pancreatic cancers.
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PMID:Overexpressed P-cadherin/CDH3 promotes motility of pancreatic cancer cells by interacting with p120ctn and activating rho-family GTPases. 1583 38

Accumulated evidence has established that aberrant regulation of histone deacetylases (HDACs) is one of the major causes of the development of human malignancies. Among different iso-enzymes of HDAC and sirtuins grouped as the HDAC super family, little is known as to how histone deacetylase 2 (HDAC2) causes carcinogenesis in solid tumors. Here, in order to investigate the possible role of HDAC2 in gastric carcinogenesis, we analyzed the expression of HDAC2 in 71 gastric adenocarcinomas by immunohistochemistry. Moderate to strong expression of HDAC2 was found in 44 (62%) out of a total of 71 tumors. The majority of positive tumors, which were detected in the nucleus but not in normal gastric epithelium, did not express HDAC2 or showed only weak positive staining. Interestingly, we also noted that HDAC2 expression appeared to be associated with tumor aggressiveness as HDAC2 expression was observed to be statistically significant in advanced gastric cancer (P=0.0023, Chi-square test) and in positive lymph node metastasis (P=0.0713, Chi-square test). Taken together, these results suggest that HDAC2 may play an important role in the aggressiveness of gastric cancer.
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PMID:Increased expression of histone deacetylase 2 is found in human gastric cancer. 1586 7

Not only genomic mutations but also abnormal epigenetic methylation can significantly contribute to gene silencing and carcinogenesis. Methylation is particularly often observed in the CpG islands of the promoter regions in the regulatory genes. However, there are considerable differences in the incidence of methylation e.g. in the tumor suppressor genes, so that aberrant methylation of p16(INK4a) is relatively frequently observed in tumors, p27(Kip1) methylation is rare, and the incidence of E-cadherin methylation occurs at an intermediate rate. Although true genomic defects are generally much less common than methylation, parallel tendencies for both are often observed, probably reflecting the different levels of evolutionary advantage for tumor cells from inactivation of different genes. This also suggests that loss of p27 expression could be more a consequence of carcinogenesis, while lost p16 expression is a true oncogenic event. Due to the role of p27 in maintaining cellular quiescence, however, loss of its expression can still be a useful partial indicator of the aggressiveness of cancer. Loss of E-cadherin or its catenin partners of cellular adhesion will result in increasing invasiveness and metastatic potential of neoplastic cells but, because of several alternative routes to the same effect, incidence of lost expression for one component gene like E-cadherin does not need to be very high. Similarly, there must be a relatively high number of genes with modest or low incidence of aberrant silencing by methylation, to reflect multiple alternatives for the multistep process of carcinogenesis. Nevertheless, methylation of different genes also shows characteristic differences between different cancer and tumor types, and the epigenetic methylation patterns therefore have considerable diagnostic and prognostic potential. Realising this potential requires efficient methods for profiling the status of methylation. Such profiling methods have only recently become available and are still under relatively rapid development.
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PMID:Methylation of tumor suppressor genes p16(INK4a), p27(Kip1) and E-cadherin in carcinogenesis. 1597 59


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