UMLS:C0596263 - FACTA Search

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Query: UMLS:C0596263 (carcinogenesis)
64,820 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The work described in this review addresses the multifunctional roles of growth factors and their cognate receptors in normal development and in tumorigenesis. The concept of epithelial cell plasticity is described in the context of embryonic development during which frequent remodeling occurs in epithelial tissues. The critical role of one member of the FGF family of growth factors is demonstrated in lung branching morphogenesis. Several members of this family have been shown to induce an epithelial-mesenchymal transition in a bladder carcinoma line. In vivo the same factors act in an autocrine or paracrine mode to favor tumor progression. It is suggested that an EGFR-ligand autocrine loop exerts a positive role in tumor progression of human bladder carcinoma whereas FGFR2 acts as a phenotypic tumor suppressor gene. Unexpectedly, constitutive activating mutations in FGFR3 have been uncovered in the majority of the Ta superficial tumors which progress only very rarely to the invasive stages. In contrast, in situ carcinoma, which are considered to be associated with a strong malignant potential, do not carry the FGFR3 mutations. The presence or absence of the mutations defines two distinct oncogenic pathways in bladder carcinogenesis. The studies reveal the complexities in defining the putative functions of growth factors at different times and differentiation stages during development and in tumor progression. These results emphasize the need for caution in the interpretation of studies evaluating the potential of novel anti-cancer agents and for better designs of in vitro and in vivo biological assays.
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PMID:[Role of growth factor signaling in epithelial cell plasticity during development and in carcinogenesis]. 1197 24

Bladder cancer is the most common urinary tumors in China. Carcinogenesis of bladder is a multistep process. Accumulation of abnormal genotypes in a long period leads to malignant phenotypes. The genes associated with bladder carcinogenesis include oncogenes (such as H-ras, FGFR3, erbB2, CCND1, mdm2), tumor suppressor genes (such as INK4A/ARF, Rb, TP53, PTEN, TSC1, PTCH, DBCCR1), and DNA mismatch repair genes, etc. In this review, the authors discussed the recent research advances on the genes associated with bladder carcinoma.
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PMID:[Research advances on bladder cancer associated genes]. 1256 47

Smoking is a major risk factor for urothelial cell carcinoma of the bladder (UCC). Mutations in the FGFR3 and TP53 genes have been shown to define two distinct pathways in superficial papillary and invasive UCC disease, respectively. We investigated the relationship between smoking and these mutations by means of denaturing high performance liquid chromatography and sequencing for 110 primary UCC of the bladder. This study included 48 current smokers, 31 ex-smokers and 31 non-smokers. Thirty-five of the tumors were stage pTa, 40 pT1 and 35 > or =pT2. Fourteen of the tumors were grade 1, 37 were grade 2 and 59 grade 3. Smoking was associated with high stage (P = 0.03) and high grade tumors (P = 0.006). Twenty-two of the 110 tumors studied harbored TP53 mutations (20%) and 43 harbored FGFR3 mutations (39%). Odds ratios (OR) were higher for TP53 mutations in current smokers [OR, 2.25; 95% confidence interval (95% CI), 0.65-7.75] and ex-smokers (OR, 1.62; 95% CI, 0.41-6.42) than in non-smokers. Double TP53 mutations and the A:T-->G:C TP53 mutation pattern was found only in current smokers. Patients with the FGFR3(wild-type)/TP53(mutated) genotype had significantly higher levels of tobacco consumption, as measured in pack-years (P = 0.01). Smoking influenced neither the frequency nor the pattern of FGFR3 mutations. Our results suggest that smoking is associated with invasive and high grade UCCs, at initial presentation, and influenced TP53 or the molecular pathway defined by these mutations. In contrast, FGFR3 mutations are not affected by smoking and probably result from endogenous alterations. These data have potential implications for clinical management and prevention strategies.
Carcinogenesis 2005 Jan
PMID:Mutations in TP53, but not FGFR3, in urothelial cell carcinoma of the bladder are influenced by smoking: contribution of exogenous versus endogenous carcinogens. 1534 1

Overexpression of fibroblast growth factors (FGFs) has been implicated in prostate carcinogenesis. FGFs function via their high-affinity interactions with receptor tyrosine kinases, FGFR1-4. Expression of FGFR1 and FGFR2 in prostate cancer (CaP) was not found to be associated with clinical parameters. In this report, we further investigated for abnormal FGFR expression in prostate cancer and explore their significance as a potential target for therapy. The expression levels of FGFR3 and FGFR4 in CaP were examined and corroborated to clinical parameters. FGFR3 immunoreactivity in benign prostatic hyperplasia (BPH) and CaP (n=26 and 57, respectively) had similar intensity and pattern. Overall, FGFR4 expression was significantly upregulated in CaP when compared to BPH. A significant positive correlation between FGFR4 expression and Gleason score was noted: Gleason score 7-10 tumours compared to BPH (P<0.0001, Fisher's exact test), Gleason score 4-6 tumours compared to BPH (P<0.0004), and Gleason 7-10 compared to Gleason 4-6 tumours (P<0.005). FGFR4 overexpression was associated with an unfavourable outcome with decreased disease-specific survival (P<0.04, log rank test). FGF-induced signalling is targeted using soluble FGF receptor (sFGFR), potent inhibitor of FGFR function. We have previously shown that sFGFR expression via a replication-deficient adenoviral vector (AdlllcRl) suppresses in vitro FGF-induced signalling and function in human CaP DU145 cells. We tested the significance of inhibiting FGF function along with conventional therapeutic modalities in CaP, and confirmed synergistic effects on in vitro cell growth (proliferation and colony formation) by combining sFGFR expression and treatment with either Paclitaxel (Taxol) or gamma-irradiation. In summary, our data support the model of FGF system as valid target for therapy in CaP.
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PMID:Evaluation of the fibroblast growth factor system as a potential target for therapy in human prostate cancer. 1565 58

Germinal activating mutations of FGFR3 are responsible for several forms of dwarfism due to the inhibitory effect of FGFR3 on bone growth. Surprisingly, identical somatic activating mutations have been found at the somatic level in tumours: at high frequency in benign epithelial tumours (seborrheic keratosis, urothelial papilloma) and in low-grade, low-stage urothelial carcinomas, and at a lower frequency in other types of urothelial carcinoma, in cervix carcinoma, and in haematological cancer, multiple myeloma. FGFR3 exists as two isoforms, FGFR3b and FGFR3c, differs in ligand specificity and tissue expression. FGFR3b is the main form in epithelial cells and derived tumours, whereas FGFR3c is the main form in mesenchyme-derived cells and multiple myeloma. Several lines of evidence suggest that mutated FGFR3c has transforming properties. Although mutated FGFR3b is mostly found in benign epithelial tumours or carcinomas of low malignant potential, we present evidence here that mutated FGFR3b is oncogenic. All bladder tumours presenting FGFR3 mutations expressed this receptor more strongly than normal urothelium or non-mutated tumours. NIH-3T3 cells transfected with a mutated form of FGFR3b--FGFR3b-S249C, the most common mutation in bladder tumours--presented a spindle-cell morphology, grew in soft agar and gave rise to tumours when xenografted into nude mice. We identified one line of 17 bladder cell lines tested (MGH-U3) that expressed a mutated form of FGFR3b, FGFR3b-Y375C. We showed using siRNA and SU5402, an FGFR inhibitor, that the tumour properties of MGH-U3 depended on mutated receptor activity. Thus, in two different models, mutated FGFR3b presents oncogenic properties.
Carcinogenesis 2006 Apr
PMID:Oncogenic properties of the mutated forms of fibroblast growth factor receptor 3b. 1633 52

Bladder tumors constitute a very heterogeneous disease. Superficial tumors are characterized by a high prevalence of FGFR3 mutations and chromosome 9 alterations. High-grade and muscle-invasive tumors are characterized by Tp53 mutations and aneuploidy. We have analyzed the sequence of exons 9 and 20 of PIK3CA in a panel of bladder tumors covering the whole spectrum of the disease. DNA from formalin-fixed, paraffin-embedded tumor sections was amplified by PCR and products were sequenced. In an unselected panel of tumors representative of the disease, the PIK3CA mutation prevalence was 13% (11 of 87). Mutations occurred mainly at the previously identified hotspots (codons 542, 545, 1007, and 1047). The distribution according to stage was as follows: papillary urothelial neoplasms of uncertain malignant potential (PUNLMP; 11 of 43, 25.6%), T(a) (9 of 57, 16%), T(1) (2 of 10, 20%), and muscle-invasive tumors (0 of 20, 0%; P = 0.019). Mutations were associated with low-grade tumors: grade 1 (6 of 27, 22.2%), grade 2 (3 of 23, 13%), and grade 3 (2 of 37, 5.4%; P = 0.047). Overall, PIK3CA mutations were strongly associated with FGFR3 mutations: 18 of 69 (26%) FGFR3(mut) tumors were PIK3CA(mut), versus 4 of 58 (6.9%) FGFR3(wt) tumors (P = 0.005). Our findings indicate that PIK3CA mutations are a common event that can occur early in bladder carcinogenesis and support the notion that papillary and muscle-invasive tumors arise through different molecular pathways. PIK3CA may constitute a novel diagnostic and prognostic tool, as well as a therapeutic target, in bladder cancer.
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PMID:PIK3CA mutations are an early genetic alteration associated with FGFR3 mutations in superficial papillary bladder tumors. 1688 34

A panel of markers, selected for the suspected bladder cancer relevance of their corresponding genes, were explored for their expression and subcellular location in urinary bladder tissue. The expression in normal urothelium, in non-metastasised transitional cell carcinomas (TCC), and in primary metastasised TCC with corresponding metastases was mapped. Potential associations between the proteins were identified. The observations were then combined in a set of hypotheses aimed at further hypothesis testing. Membranous ERBB4 and cytoplasmic p21RAS were downregulated in carcinoma cells compared with normal urothelium cells. FGFR3 was translocated from the cytoplasm to the nucleus. ERBB2 was translocated to the membrane and seemingly upregulated in one subgroup and conversely downregulated in another. EGFR, KAI1 and possibly PTEN revealed increased membranous immunoreactivity in non-metastasised tumours. The metastases showed decreased nuclear FGFR3 and membranous PTEN staining compared with corresponding primary tumours. EGFR expression was positively correlated with the expression of PTEN and FGFR3. The expression of ERBB2 was negatively correlated with p21RAS expression. According to our results, bladder carcinogenesis comprises FGFR3 translocation to the nucleus, upregulation of EGFR, ERBB2, KAI1 and PTEN; downregulation of p21RAS; and translocation of EGFR, ERBB2, and possibly PTEN to the membrane. Our results support the hypotheses regarding PTEN and KAI1 functioning as tumour suppressors in bladder cancer. EGFR and KAI1 may discriminate between non-metastasised and metastasised cancers. A complex network of associations between the factors is suggested.
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PMID:Protein networking in bladder cancer: immunoreactivity for FGFR3, EGFR, ERBB2, KAI1, PTEN, and RAS in normal and malignant urothelium. 1729 Mar 45

Tumor recurrence is a major clinical concern for patients with urothelial carcinoma of the urinary bladder. Traditional morphological analysis is of limited utility for identifying cases in which recurrence will occur. However, molecular and genetic analyses offer new perspectives on the prediction of bladder tumor recurrence. Recent studies have suggested that urothelial carcinogenesis occurs as a 'field effect' that can involve any number of sites in the bladder mucosa. Accumulating evidence supports the notion that resident urothelial stem cells in the affected field are transformed into cancer stem cells by acquiring genetic alterations that lead to tumor formation through clonal expansion. Both initial and recurrent tumors are derived from cancer stem cells in the affected field via two distinct molecular pathways. These provide a genetic framework for understanding urothelial carcinogenesis, tumor recurrence and progression: the FGFR3-associated pathway and the TP53-associated pathway. These two pathways are characterized by different genomic, epigenetic and gene-expression alterations. Their outcomes correlate with the markedly different clinical and pathologic features of both relatively indolent low-grade cancers and the aggressive high-grade cancers. As such, these molecular findings are potentially useful for counseling patients and for assessing risk of recurrence or biological aggressiveness of the patient's tumor. The molecular changes may additionally prove useful for developing preventive and therapeutic strategies for urothelial bladder cancer. A unifying model of urothelial carcinogenesis, tumor recurrence and progression is proposed in this review.
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PMID:Molecular determinants of tumor recurrence in the urinary bladder. 1966 34

Urothelial carcinoma of the bladder (UCC) is a common disease that arises by at least two different molecular pathways. The biology of UCC is incompletely understood, making the management of this disease difficult. Recent evidence implicates a regulatory role for microRNA in cancer. We hypothesized that altered microRNA expression contributes to UCC carcinogenesis. To test this hypothesis, we examined the expression of 322 microRNAs and their processing machinery in 78 normal and malignant urothelial samples using real-time rtPCR. Genes targeted by differentially expressed microRNA were investigated using real-time quantification and microRNA knockdown. We also examined the role of aberrant DNA hypermethylation in microRNA downregulation. We found that altered microRNA expression is common in UCC and occurs early in tumorogenesis. In normal urothelium from patients with UCC, 11% of microRNAs had altered expression when compared with disease-free controls. This was associated with upregulation of Dicer, Drosha, and Exportin 5. In UCC, microRNA alterations occur in a tumor phenotype-specific manner and can predict disease progression. High-grade UCC were characterized by microRNA upregulation, including microRNA-21 that suppresses p53 function. In low-grade UCC, there was downregulation of many microRNA molecules. In particular, loss of microRNAs-99a/100 leads to upregulation of FGFR3 before its mutation. Promoter hypermethylation is partly responsible for microRNA downregulation. In conclusion, distinct microRNA alterations characterize UCC and target genes in a pathway-specific manner. These data reveal new insights into the disease biology and have implications regarding tumor diagnosis, prognosis and therapy.
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PMID:Distinct microRNA alterations characterize high- and low-grade bladder cancer. 1984 43

Transitional cell (urothelial) carcinoma of the bladder is the second most common urologic malignancy and is one of the best understood neoplasms, with relatively well-defined pathogenetic pathways, natural history, and tumor biology. Conventional clinical and pathologic parameters are widely used to grade and stage tumors and to predict clinical outcome of transitional cell carcinoma; but the predictive ability of these parameters is limited, and there is a lack of indices that could allow prospective assessment of risk for individual patients. In the last decade, a wide range of candidate biomarkers representing key pathways in carcinogenesis have been reported to be clinically relevant and potentially useful as diagnostic and prognostic molecular markers, and as potential therapeutic targets. The use of molecular markers has facilitated the development of novel and more accurate diagnostic, prognostic, and therapeutic strategies. FGFR3 and TP53 mutations have been recognized as key genetic pathways in the carcinogenesis of transitional cell carcinoma. FGFR3 appears to be the most frequently mutated oncogene in transitional cell carcinoma; its mutation is strongly associated with low tumor grade, early stage, and low recurrence rate, which confer a better overall prognosis. In contrast, TP53 mutations are associated with higher tumor grade, more advanced stage, and more frequent tumor recurrences. These molecular markers offer the potential to characterize individual urothelial neoplasms more completely than is possible by histologic evaluation alone. Areas in which molecular markers may prove valuable include prediction of tumor recurrence, molecular staging of transitional cell carcinoma, detection of lymph node metastasis and circulating cancer cells, identification of therapeutic targets, and prediction of response to therapy. With accumulating molecular knowledge of transitional cell carcinoma, we are closer to the goal of bridging the gap between molecular findings and clinical outcomes. Assessment of key genetic pathways and expression profiles could ultimately establish a set of molecular markers to predict the biological nature of tumors and to establish new standards for molecular tumor grading, classification, and prognostication. The main focus of this review is to discuss clinically relevant biomarkers that might be useful in the management of transitional cell carcinoma and to provide approaches in the analysis of molecular pathways that influence the clinical course of bladder cancer.
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PMID:Bladder cancer: translating molecular genetic insights into clinical practice. 2110 20

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