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Castellani C, Cuppens H, Macek M, Cassiman JJ, Kerem E, Durie P, Tullis E, Assael BM, Bombieri C, Brown A, Casals T, Claustres M, Cutting GR, Dequeker E, Dodge J, Doull I, Farrell P, Ferec C, Girodon E, Johannesson M, Kerem B, Knowles M, Munck A, Pignatti PF, Radojkovic D, Rizzotti P, Schwarz M, Stuhrmann M, Tzetis M, Zielenski J, Elborn JS. Consensus on the use and interpretation of cystic fibrosis mutation analysis in clinical practice. J Cyst Fibros 2008; 7:179-96. [PMID: 18456578 PMCID: PMC2810954 DOI: 10.1016/j.jcf.2008.03.009] [Citation(s) in RCA: 401] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2007] [Accepted: 03/14/2008] [Indexed: 02/06/2023]
Abstract
It is often challenging for the clinician interested in cystic fibrosis (CF) to interpret molecular genetic results, and to integrate them in the diagnostic process. The limitations of genotyping technology, the choice of mutations to be tested, and the clinical context in which the test is administered can all influence how genetic information is interpreted. This paper describes the conclusions of a consensus conference to address the use and interpretation of CF mutation analysis in clinical settings. Although the diagnosis of CF is usually straightforward, care needs to be exercised in the use and interpretation of genetic tests: genotype information is not the final arbiter of a clinical diagnosis of CF or CF transmembrane conductance regulator (CFTR) protein related disorders. The diagnosis of these conditions is primarily based on the clinical presentation, and is supported by evaluation of CFTR function (sweat testing, nasal potential difference) and genetic analysis. None of these features are sufficient on their own to make a diagnosis of CF or CFTR-related disorders. Broad genotype/phenotype associations are useful in epidemiological studies, but CFTR genotype does not accurately predict individual outcome. The use of CFTR genotype for prediction of prognosis in people with CF at the time of their diagnosis is not recommended. The importance of communication between clinicians and medical genetic laboratories is emphasized. The results of testing and their implications should be reported in a manner understandable to the clinicians caring for CF patients.
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Consensus Development Conference |
17 |
401 |
2
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Knowles M, Gatzy J, Boucher R. Increased bioelectric potential difference across respiratory epithelia in cystic fibrosis. N Engl J Med 1981; 305:1489-95. [PMID: 7300874 DOI: 10.1056/nejm198112173052502] [Citation(s) in RCA: 396] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
To investigate respiratory epithelial function in cystic fibrosis, we measured the transepithelial electrical potential difference across the upper and lower respiratory mucosa in patients with cystic fibrosis and control subjects. The nasal potential difference in the 24 patients with cystic fibrosis exceeded by more than 3 standard deviations the mean voltage in healthy controls, subjects with other diseases, and subjects heterozygous for cystic fibrosis. Potential differences in lower airways were measured in four patients and were significantly greater than in controls (P less than 0.05). Superfusion of the luminal surface with amiloride, an inhibitor of active sodium absorption, induced greater reductions in both nasal and airway potential difference in patients than in controls. We conclude that the increased respiratory-epithelial potential differences appear to be a specific abnormality in homozygotes for cystic fibrosis. The greater reduction in potential difference in response to amiloride suggests that absorption of excess salt and perhaps liquid from respiratory epithelial surfaces contributes to the pathogenesis of lung disease in cystic fibrosis.
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44 |
396 |
3
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Tomlinson DC, Baldo O, Harnden P, Knowles MA. FGFR3 protein expression and its relationship to mutation status and prognostic variables in bladder cancer. J Pathol 2007; 213:91-8. [PMID: 17668422 PMCID: PMC2443273 DOI: 10.1002/path.2207] [Citation(s) in RCA: 269] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2007] [Accepted: 06/14/2007] [Indexed: 11/12/2022]
Abstract
FGFR3 is frequently activated by mutation in urothelial carcinoma (UC) and represents a potential target for therapy. In multiple myeloma, both over-expression and mutation of FGFR3 contribute to tumour development. To define the population of UC patients who may benefit from FGFR-targeted therapy, we assessed both mutation and receptor over-expression in primary UCs from a population of new patients. Manual or laser capture microdissection was used to isolate pure tumour cell populations. Where present, non-invasive and invasive components in the same section were microdissected. A screen of the region of the highest tumour stage in each sample yielded a mutation frequency of 42%. Mutations comprised 61 single and five double mutations, all in hotspot codons previously identified in UC. There was a significant association of mutation with low tumour grade and stage. Subsequently, non-invasive areas from the 43 tumours with both non-invasive and invasive components were analysed separately; 18 of these had mutation in at least one region, including nine with mutation in all regions examined, eight with mutation in only the non-invasive component and one with different mutations in different regions. Of the eight with mutation in only the non-invasive component, six were predicted to represent a single tumour and two showed morphological dissimilarity of fragments within the block, indicating the possible presence of distinct tumour clones. Immunohistochemistry showed over-expression of FGFR3 protein in many tumours compared to normal bladder and ureteric controls. Increased expression was associated with mutation (85% of mutant tumours showed high-level expression). Overall, 42% of tumours with no detectable mutation showed over-expression, including many muscle-invasive tumours. This may represent a non-mutant subset of tumours in which FGFR3 signalling contributes to the transformed phenotype and which may benefit from FGFR-targeted therapies.
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research-article |
18 |
269 |
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Corey M, Edwards L, Levison H, Knowles M. Longitudinal analysis of pulmonary function decline in patients with cystic fibrosis. J Pediatr 1997; 131:809-14. [PMID: 9427882 DOI: 10.1016/s0022-3476(97)70025-8] [Citation(s) in RCA: 256] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND Chronic progressive lung disease is the most prominent cause of morbidity and death in patients with cystic fibrosis (CF), but severity of lung disease and rate of lung function decline are widely variable. Accurate estimates of decline have been difficult to define and compare because the timing of measurements and duration of follow-up differ in various patient groups. PATIENTS Three hundred sixty-six patients with CF, born from 1960 to 1974, were selected from a CF database birth cohort if they had two or more measurements of pulmonary function, at least one of which was performed before the age of 10 years. METHODS Mixed model regression analysis provided estimates of the average rate of decline of spirometry measurements in subgroups on the basis of survival age, sex, pancreatic status, and genotype. RESULTS Patients who died before the age of 15 years had significantly poorer pulmonary function when first tested and a more rapid decline in pulmonary function thereafter than patients who survived beyond the age of 15 years. In the latter, functional levels at the age of 5 years were normal, but average rates of decline were significantly related to survival age. Female patients had significantly steeper decline than male patients, and those with pancreatic insufficiency had much steeper decline than those with pancreatic sufficiency. In the subset of 197 who survived to 1990 and were subsequently genotyped, rate of decline was greater in those homozygous for the delta F508 mutation, compared with those who were heterozygous for delta F508 or those, who had two other mutations. DISCUSSION All but the most severely affected patients, who died before age 15, appear to have had normal pulmonary function when first tested in early childhood. Pancreatic sufficiency, male gender, and some non-delta F508 mutations are associated with a slower rate of pulmonary function decline. Mixed model analysis is a valuable tool for describing and comparing pulmonary function decline in groups of patients with CF.
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28 |
256 |
5
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Knowles M, Gatzy J, Boucher R. Relative ion permeability of normal and cystic fibrosis nasal epithelium. J Clin Invest 1983; 71:1410-7. [PMID: 6853720 PMCID: PMC437005 DOI: 10.1172/jci110894] [Citation(s) in RCA: 199] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The raised transepithelial electric potential difference (PD) across respiratory epithelia in cystic fibrosis (CF) has suggested an abnormality in ion permeation. We characterized this abnormality further by measuring in the nasal epithelia of CF and normal subjects the concentration-PD relationship for amiloride, an inhibitor of cell Na+ permeability, and PD responses to superfusion with solutions of different composition. Amiloride was more efficacious in the CF subjects but the ED50 was not different from that of normals (approximately 2 X 10(-6) M). Na+ replacement by choline induced effects similar to those of amiloride, i.e. a greater depolarization in CF subjects. A 10-fold increase in the K+ concentration of the perfusate induced a small (less than 10 mV) depolarization in both subject populations. When Cl- in the perfusate was replaced by gluconate or SO2-(4) the nasal PD of normal subjects hyperpolarized (lumen became more negative) by approximately 35 mV. A significantly smaller response (less than 17 mV) was induced in CF homozygotes but not in heterozygotes (38 mV). The smaller response of CF subjects appears to reflect an absolute decrease in luminal surface Cl- permeability because pretreatment with amiloride did not increase the response to Cl- free solution (7 mV). Accordingly, three abnormalities (decreased Cl- permeability, raised PD, greater amiloride efficacy) have been identified in CF respiratory epithelia. Whereas "excessive" active Na+ transport can account for these abnormalities and the dessication of airway surface liquid, it is possible that a lower lumenal cell membrane Cl- permeability and inhibition of a potential path of Cl- secretion can also explain the observations.
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research-article |
42 |
199 |
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Randerson-Moor JA, Harland M, Williams S, Cuthbert-Heavens D, Sheridan E, Aveyard J, Sibley K, Whitaker L, Knowles M, Bishop JN, Bishop DT. A germline deletion of p14(ARF) but not CDKN2A in a melanoma-neural system tumour syndrome family. Hum Mol Genet 2001; 10:55-62. [PMID: 11136714 DOI: 10.1093/hmg/10.1.55] [Citation(s) in RCA: 179] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The melanoma-astrocytoma syndrome is characterized by a dual predisposition to melanoma and neural system tumours, commonly astrocytoma. Germline deletions of the region on 9p21 containing the CDKN2A and CDKN2B genes and CDKN2A exon 1beta have been reported in kindreds, implicating contiguous tumour suppressor gene deletion as a cause of this syndrome. We describe a family characterized by multiple melanoma and neural cell tumours segregating with a germline deletion of the p14(ARF)-specific exon 1beta of the CDKN2A gene. This deletion does not affect the coding or minimal promoter sequences of either the CDKN2A or CDKN2B genes. Our results are consistent with either: (i) loss of p14(ARF) function being the critical abnormality associated with this syndrome, rather than contiguous loss of both the CDKN2A and CDKN2B genes as suggested previously; or (ii) disruption of expression of p16 by mechanisms as yet unknown.
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24 |
179 |
7
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Patick AK, Duran M, Cao Y, Shugarts D, Keller MR, Mazabel E, Knowles M, Chapman S, Kuritzkes DR, Markowitz M. Genotypic and phenotypic characterization of human immunodeficiency virus type 1 variants isolated from patients treated with the protease inhibitor nelfinavir. Antimicrob Agents Chemother 1998; 42:2637-44. [PMID: 9756769 PMCID: PMC105911 DOI: 10.1128/aac.42.10.2637] [Citation(s) in RCA: 158] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Nelfinavir mesylate (formerly AG1343) is a potent and selective inhibitor of human immunodeficiency virus (HIV) protease approved for the treatment of individuals infected with HIV. Nucleotide sequence analysis of protease genes from plasma HIV type 1 (HIV-1) RNA revealed a unique aspartic acid (D)-to-asparagine (N) substitution at residue 30 (D30N) in 25 of 55 patients treated with nelfinavir for a median of 13 weeks. Although the appearance of D30N was occasionally associated with concurrent or sequential emergence of other changes (e.g., at residues 35, 36, 46, 71, 77, and 88), genotypic changes associated with phenotypic resistance to other protease inhibitors were not observed (e.g., at residues 48, 50, 82, and 84) or were only rarely observed (e.g., at residue 90). In phenotypic assays, viral isolates with high-level resistance to nelfinavir remained susceptible to indinavir, saquinavir, ritonavir, and amprenavir (formerly VX-478/141W94). Similar results were observed in phenotypic assays utilizing HIV-1 NL4-3, which contained the D30N substitution alone or in combination with substitutions at other residues (e.g., residues 46, 71, and 88). These data indicate that the initial pathway of resistance to nelfinavir is unique and suggest that individuals failing short courses of nelfinavir-containing regimens may respond to regimens containing other protease inhibitors.
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research-article |
27 |
158 |
8
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Lamont FR, Tomlinson DC, Cooper PA, Shnyder SD, Chester JD, Knowles MA. Small molecule FGF receptor inhibitors block FGFR-dependent urothelial carcinoma growth in vitro and in vivo. Br J Cancer 2011; 104:75-82. [PMID: 21119661 PMCID: PMC3039817 DOI: 10.1038/sj.bjc.6606016] [Citation(s) in RCA: 147] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Revised: 10/22/2010] [Accepted: 10/28/2010] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND Activating mutations of FGFR3 are frequently identified in superficial urothelial carcinoma (UC) and increased expression of FGFR1 and FGFR3 are common in both superficial and invasive UC. METHODS The effects of inhibition of receptor activity by three small molecule inhibitors (PD173074, TKI-258 and SU5402) were investigated in a panel of bladder tumour cell lines with known FGFR expression levels and FGFR3 mutation status. RESULTS All inhibitors prevented activation of FGFR3, and inhibited downstream MAPK pathway signalling. Response was related to FGFR3 and/or FGFR1 expression levels. Cell lines with the highest levels of FGFR expression showed the greatest response and little or no effect was measured in normal human urothelial cells or in UC cell lines with activating RAS gene mutations. In sensitive cell lines, the drugs induced cell cycle arrest and/or apoptosis. IC(50) values for PD173074 and TKI-258 were in the nanomolar concentration range compared with micromolar concentrations for SU5402. PD173074 showed the greatest effects in vitro and in vivo significantly delayed the growth of subcutaneous bladder tumour xenografts. CONCLUSION These results indicate that inhibition of FGFR1 and wild-type or mutant FGFR3 may represent a useful therapeutic approach in patients with both non-muscle invasive and muscle invasive UC.
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MESH Headings
- Animals
- Apoptosis/drug effects
- Benzimidazoles/therapeutic use
- Blotting, Western
- Carcinoma, Transitional Cell/metabolism
- Carcinoma, Transitional Cell/pathology
- Carcinoma, Transitional Cell/prevention & control
- Cell Cycle/drug effects
- Cell Proliferation/drug effects
- Cells, Cultured
- Humans
- Immunoenzyme Techniques
- In Vitro Techniques
- Male
- Mice
- Mice, Inbred BALB C
- Mutation/genetics
- Phosphorylation/drug effects
- Protein-Tyrosine Kinases/antagonists & inhibitors
- Pyrimidines/therapeutic use
- Pyrroles/therapeutic use
- Quinolones/therapeutic use
- Receptor, Fibroblast Growth Factor, Type 1/antagonists & inhibitors
- Receptor, Fibroblast Growth Factor, Type 1/metabolism
- Receptor, Fibroblast Growth Factor, Type 3/antagonists & inhibitors
- Receptor, Fibroblast Growth Factor, Type 3/metabolism
- Urinary Bladder Neoplasms/metabolism
- Urinary Bladder Neoplasms/pathology
- Urinary Bladder Neoplasms/prevention & control
- Urothelium/drug effects
- Urothelium/metabolism
- Xenograft Model Antitumor Assays
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Comparative Study |
14 |
147 |
9
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Kissil JL, Feinstein E, Cohen O, Jones PA, Tsai YC, Knowles MA, Eydmann ME, Kimchi A. DAP-kinase loss of expression in various carcinoma and B-cell lymphoma cell lines: possible implications for role as tumor suppressor gene. Oncogene 1997; 15:403-7. [PMID: 9242376 DOI: 10.1038/sj.onc.1201172] [Citation(s) in RCA: 146] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
DAP-kinase is a novel calmodulin dependent serine/threonine kinase that carries ankyrin repeats and the death domain. It was recently isolated, by a functional selection approach of gene cloning, as a positive mediator of programmed cell death. In this study the expression of DAP-kinase was examined in the cell lines derived from various human neoplasms. DAP-kinase mRNA and protein expression were below the limit of detection in eight out of ten neoplastic derived B-cell lines. In six out of 14 examined bladder carcinoma, in three out of five renal cell carcinoma, and in four out of ten tested breast carcinoma cell lines, the DAP-kinase protein levels were below detection limits or lower than 1% compared to the positive cell lines. Interestingly, DAP-kinase expression could be restored in some of the negative bladder carcinoma and B-cell lines by treatment of cells with 5'-azadeoxycytidine that causes DNA demethylation. The high frequency of loss of DAP-kinase expression in human tumor cell lines, and the occasional involvement of methylation in this process raise the possibility that this novel mediator of cell death may function as a tumor suppressor gene.
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28 |
146 |
10
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Knowles M, Murray G, Shallal J, Askin F, Ranga V, Gatzy J, Boucher R. Bioelectric properties and ion flow across excised human bronchi. JOURNAL OF APPLIED PHYSIOLOGY: RESPIRATORY, ENVIRONMENTAL AND EXERCISE PHYSIOLOGY 1984; 56:868-77. [PMID: 6144659 DOI: 10.1152/jappl.1984.56.4.868] [Citation(s) in RCA: 128] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Bioelectric properties and ion transport of excised human segmental/subsegmental bronchi were measured in specimens from 40 patients. Transepithelial electric potential difference (PD), short-circuit current (Isc), and conductance (G), averaged 5.8 mV (lumen negative), 51 microA X cm-2, and 9 mS X cm-2, respectively. Na+ was absorbed from lumen to interstitium under open- and short-circuit conditions. Cl- flows were symmetrical under short-circuit conditions. Isc was abolished by 10(-4) M ouabain. Amiloride inhibited Isc (the concentration necessary to achieve 50% of the maximal effect = 7 X 10(-7) M) and abolished net Na+ transport. PD and Isc were not reduced to zero by amiloride because a net Cl- secretion was induced that reflected a reduction in Cl- flow in the absorptive direction (Jm----sCl-). Acetylcholine (10(-4) M) induced an electrically silent, matched flow of Na+ (1.7 mueq X cm-1 X h-1) and Cl- (1.9 mueq X cm-12 X h-1) toward the lumen. This response was blocked by atropine. Phenylephrine (10(-5) M) did not affect bioelectric properties or unidirectional ion flows, whereas isoproterenol (10(-5) M) induced a small increase in Isc (10%) without changing net ion flows significantly. We conclude that 1) Na+ absorption is the major active ion transport across excised human bronchi, 2) Na+ absorption is both amiloride and ouabain sensitive, 3) Cl- secretion can be induced by inhibition of the entry of luminal Na+ into the epithelia, and 4) cholinergic more than adrenergic agents modulate basal ion flow, probably by affecting gland output.
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Comparative Study |
41 |
128 |
11
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Coombs LM, Pigott DA, Sweeney E, Proctor AJ, Eydmann ME, Parkinson C, Knowles MA. Amplification and over-expression of c-erbB-2 in transitional cell carcinoma of the urinary bladder. Br J Cancer 1991; 63:601-8. [PMID: 1673627 PMCID: PMC1972370 DOI: 10.1038/bjc.1991.139] [Citation(s) in RCA: 127] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The structure and expression of the proto-oncogene c-erbB-2 was studied in 86 patients with transitional cell carcinoma. Initial tissue samples comprised 37 grade 1, 32 grade 2 and 13 grade 3 tumours and four cases of carcinoma in situ. At the time of this first tumour sample, amplification of the c-erbB-2 gene was demonstrated by Southern blotting in 1/37 grade 1, 5/32 grade 2 and 6/13 grade 3 tumours (0.005 less than P less than 0.01). Tumour 're-occurrences' were obtained from 23 of these patients on one or more occasions. Amplification was detected in re-occurrences from seven of these 23, none of whom showed amplification in the first tumour sample. DNA was also extracted from exfoliated cells in urine collected from five cases of carcinoma in situ and c-erbB-2 amplification was demonstrated in one of these. No gene amplification was identified in patients' lymphocytes, ten biopsies of normal urothelium and 22 various intravesical pathologies. Increased expression of c-erbB-2 mRNA correlated with amplification of the gene. In addition, raised levels of mRNA were seen in the absence of gene amplification in six tumours. Immunoblotting using the polyclonal antibody 21N, raised against the c-terminus of the c-erbB-2 protein demonstrated increased amounts of a 185 kD immunoreactive protein in tumours with increased c-erbB-2 gene copy number compared with control tissues. In some tumours with high c-erbB-2 gene copy number, a 155 kD immunoreactive protein not detected in controls was expressed at higher level than the 185 kD protein. Immunocytochemistry using a monoclonal antibody AB-3, raised against the c-terminus of the c-erbB-2 protein, showed a positive reaction in the cytoplasm and cell membrane of tumours with gene amplification and in 40% of tumours with no amplification. An association was found between c-erbB-2 amplification and over-expression and the development of tumour re-occurrences. We suggest that c-erbB-2 amplification and over-expression may provide a useful molecular marker in transitional cell carcinoma of the bladder and merits further investigation as a potential prognostic indicator.
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research-article |
34 |
127 |
12
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Williamson MP, Elder PA, Shaw ME, Devlin J, Knowles MA. p16 (CDKN2) is a major deletion target at 9p21 in bladder cancer. Hum Mol Genet 1995; 4:1569-77. [PMID: 8541841 DOI: 10.1093/hmg/4.9.1569] [Citation(s) in RCA: 127] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The p16 gene has been identified as a candidate tumour suppressor gene at 9p21, a region commonly deleted in bladder cancer. We screened 140 bladder tumours and 16 cell lines for deletions and sequence variants of p16. Eight cell lines showed homozygous deletion of p16 and two had small sequence variations. All 13 tumours with small defined deletions of 9p21, 18/31 (58%) of tumours with monosomy 9 and 9/91 (10%) of tumours with no chromosome 9 loss of heterozygosity had homozygous deletion of p16. No tumour-specific sequence variants were identified. Deletion mapping revealed a nested set of deletions focused on p16. Six deletions involved p16 but not the related and adjacent gene p15 and one tumour had an intragenic deletion of p16. All other deletions involved both p16 and p15. We conclude that p16 represents the major target for deletion at 9p21 in bladder cancer.
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30 |
127 |
13
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Abstract
There is much information on the genetic alterations that contribute to the development of bladder cancer. Because it is hypothesised that the genotype of the cancer cell plays a major role in determining phenotype, this genetic information should impact on clinical practice. To date however, this has not happened. Some of the alterations identified in bladder cancer have clear associations with outcome-for example, mutational inactivation of the cell cycle regulator proteins p53 and the retinoblastoma protein (Rb). However, as single markers, these events have insufficient predictive power to be applied in the management of individual patients. The use of panels of markers is a potential solution to this problem. Examples of suitable panels include those genes/proteins with known impact on specific cell cycle checkpoints or with impact on cellular phenotypes, such as immortalisation, invasion, or metastasis. To evaluate such marker panels, large tumour series will be needed-for example, archival samples from completed clinical trials. The use of these valuable resources will require coordination of sample provision. This might involve central collection and distribution of tissue blocks, sections, or tissue arrays and the provision of patient follow up information to laboratories participating in a study. With the availability of microarray technologies, including cDNA and comparative genomic hybridisation arrays, the transcriptome and genome of transitional cell carcinomas of different phenotypes can be compared and will undoubtedly provide a wealth of information with potential diagnostic and prognostic uses. Although these studies can be initiated using small local tissue collections, high quality collection of fresh tissues from new clinical trials will be crucial for proper evaluation of associations with clinical outcome. Funding for molecular pathological studies to date has been poor. To begin to translate molecular information from the laboratory to the clinic and to make maximum use of valuable urological patient resources in the UK, adequate funding and scientific energy are required. Whereas the latter is not in doubt, present funding for this type of translational research is inadequate.
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review-article |
24 |
110 |
14
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Tomlinson DC, Hurst CD, Knowles MA. Knockdown by shRNA identifies S249C mutant FGFR3 as a potential therapeutic target in bladder cancer. Oncogene 2007; 26:5889-99. [PMID: 17384684 PMCID: PMC2443272 DOI: 10.1038/sj.onc.1210399] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2006] [Revised: 12/14/2006] [Accepted: 02/08/2007] [Indexed: 01/22/2023]
Abstract
More than 60% of low-grade non-invasive papillary urothelial cell carcinomas contain activating point mutations of fibroblast growth factor receptor 3 (FGFR3). The phenotypic consequences of constitutive activation of FGFR3 in bladder cancer have not been elucidated and further studies are required to confirm the consequences of inhibiting receptor activity in urothelial cells. We measured FGFR3 transcript levels and demonstrated that transcript levels were significantly more abundant in low-stage and grade tumours. We identified a tumour cell line, 97-7, expressing the most common FGFR3 mutation (S249C) at similar FGFR3 transcript levels to low-stage and grade tumours. In these cells, S249C FGFR3 protein formed stable homodimers and was constitutively phosphorylated. We used retrovirus-mediated delivery of shRNA to knockdown S249C FGFR3. This induced cell flattening, decreased cell proliferation and reduced clonogenicity on plastic and in soft agar. However, no effects of knockdown of wild-type FGFR3 were observed in telomerase immortalized normal human urothelial cells, indicating possible dependence of the tumour cell line on mutant FGFR3. Re-expression of S249C FGFR3 in shRNA-expressing 97-7 cells resulted in a reversal of phenotypic changes, confirming the specificity of the shRNA. These results indicate that targeted inhibition of S249C FGFR3 may represent a useful therapeutic approach in superficial bladder cancer.
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research-article |
18 |
107 |
15
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Abstract
The tumour suppressor gene PTEN/MMAC1, which is mutated or homozygously deleted in glioma, breast and prostate cancer, is mapped to a region of 10q which shows loss of heterozygosity (LOH) in bladder cancer. We screened 123 bladder tumours for LOH in the region of PTEN. In 53 informative muscle invasive tumours (> or = pT2), allele loss was detected in 13 (24.5%) and allelic imbalance in four tumours (overall frequency 32%). LOH was found in four of 60 (6.6%) informative, non-invasive tumours (pTa/pT1). We screened 63 muscle invasive tumours for PTEN mutations by single-strand conformation polymorphism (SSCP) analysis and for homozygous deletion by duplex quantitative polymerase chain reaction (PCR). Two homozygous deletions were identified but no mutations. Of 15 bladder tumour cell lines analysed, three showed homozygous deletion of all or part of the PTEN gene, but none had mutations detectable by SSCP analysis. Our results indicate that PTEN is involved in the development of some bladder tumours. The low frequency of mutation of the retained allele in tumours with 10q23 LOH suggests that there may be another predominant mechanism of inactivation of the second allele, for example small intragenic deletions, that hemizygosity may be sufficient for phenotypic effect, or that there is another target gene at 10q23.
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MESH Headings
- Carcinoma, Transitional Cell/blood
- Carcinoma, Transitional Cell/enzymology
- Carcinoma, Transitional Cell/genetics
- Chromosomes, Human, Pair 10
- DNA, Neoplasm/analysis
- DNA, Neoplasm/genetics
- Gene Deletion
- Genes, Tumor Suppressor
- Homozygote
- Humans
- Loss of Heterozygosity
- Mutation
- PTEN Phosphohydrolase
- Phosphoric Monoester Hydrolases/genetics
- Polymorphism, Single-Stranded Conformational
- Reverse Transcriptase Polymerase Chain Reaction
- Tumor Cells, Cultured
- Tumor Suppressor Proteins
- Urinary Bladder Neoplasms/blood
- Urinary Bladder Neoplasms/enzymology
- Urinary Bladder Neoplasms/genetics
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research-article |
26 |
105 |
16
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Habuchi T, Luscombe M, Elder PA, Knowles MA. Structure and methylation-based silencing of a gene (DBCCR1) within a candidate bladder cancer tumor suppressor region at 9q32-q33. Genomics 1998; 48:277-88. [PMID: 9545632 DOI: 10.1006/geno.1997.5165] [Citation(s) in RCA: 101] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Loss of heterozygosity (LOH) on chromosome 9q is the most frequent genetic alteration in transitional cell carcinoma (TCC) of the bladder, indicating the presence of one or more relevant tumor suppressor genes. We previously mapped one of these putative tumor suppressor loci to 9q32-q33 and localized the candidate region within a single YAC 840 kb in size. This locus has been designated DBC1 (for deleted in bladder cancer gene 1). We have identified a novel gene, DBCCR1, in this candidate region by searching for expressed sequence tags (ESTs) that map to YACs spanning the region. Database searching using the entire DBCCR1 cDNA sequence identified several human ESTs and a few homologous mouse. ESTs. However, the predicted 761-amino-acid sequence had no significant homology to known protein sequences. Mutation analysis of the coding region and Southern blot analysis detected neither somatic mutations nor gross genetic alterations in primary TCCs. Although DBCCR1 was expressed in multiple normal human tissues including urothelium, mRNA expression was absent in 5 of 10 (50%) bladder cancer cell lines. Methylation analysis of the CpG island at the 5' region of the gene and the induction of de novo expression by a demethylating agent indicated that this island might be a frequent target for hypermethylation and that hypermethylation-based silencing of the gene occurs in TCC. These findings make DBCCR1 a good candidate for DBC1.
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MESH Headings
- Amino Acid Sequence
- Azacitidine/analogs & derivatives
- Azacitidine/pharmacology
- Base Sequence
- Blotting, Northern
- Blotting, Southern
- Carcinoma, Transitional Cell/genetics
- Cell Cycle Proteins
- Chromosomes, Artificial, Yeast
- Chromosomes, Human, Pair 9
- CpG Islands/genetics
- DNA Methylation
- DNA, Complementary
- Decitabine
- Exons/genetics
- Gene Deletion
- Gene Expression Regulation, Neoplastic/drug effects
- Genes, Tumor Suppressor
- Humans
- Introns/genetics
- Molecular Sequence Data
- Nerve Tissue Proteins
- Polymorphism, Single-Stranded Conformational
- Proteins/genetics
- RNA, Messenger/metabolism
- Sequence Analysis, DNA
- Tumor Suppressor Proteins
- Urinary Bladder Neoplasms/genetics
- Urothelium/metabolism
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101 |
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Xu HJ, Cairns P, Hu SX, Knowles MA, Benedict WF. Loss of RB protein expression in primary bladder cancer correlates with loss of heterozygosity at the RB locus and tumor progression. Int J Cancer 1993; 53:781-4. [PMID: 8449603 DOI: 10.1002/ijc.2910530513] [Citation(s) in RCA: 97] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
RB-protein status as determined by immunohistochemical analysis was compared with loss of heterozygosity (LOH) at the RB locus in 68 primary transitional-cell carcinomas of the bladder. Absence of RB-protein expression was found in 15 of 17 tumors in which LOH at the RB locus was identified, whereas 31 of 36 tumors from informative patients which showed no LOH had a normal RB-protein pattern (p < 0.001). Altered RB-protein expression was also more frequently seen in muscle-invasive and high-grade tumors (p < 0.003 and < 0.005, respectively). Our results indicate that LOH at the RB locus is highly correlated with loss of RB-protein expression in primary bladder carcinomas and further strengthens the notion that loss of RB function may be associated with more aggressive bladder tumors.
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32 |
97 |
18
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Askham JM, Platt F, Chambers PA, Snowden H, Taylor CF, Knowles MA. AKT1 mutations in bladder cancer: identification of a novel oncogenic mutation that can co-operate with E17K. Oncogene 2009; 29:150-5. [DOI: 10.1038/onc.2009.315] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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16 |
86 |
19
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Russell MG, Baker RJ, Barden L, Beer MS, Bristow L, Broughton HB, Knowles M, McAllister G, Patel S, Castro JL. N-Arylsulfonylindole derivatives as serotonin 5-HT(6) receptor ligands. J Med Chem 2001; 44:3881-95. [PMID: 11689074 DOI: 10.1021/jm010943m] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A series of N(1)-arylsulfonyltryptamines were found to be potent ligands of the human serotonin 5-HT(6) receptor with the 5-methoxy-1-benzenesulfonyl analogue (19) having the highest affinity. Additionally, it was discovered that a group such as 3-(3-methoxybenzyl)-1,2,4-oxadiazol-5-yl in the 2-position of the indole ring (43) can replace the arylsulfonyl substituent in the 1-position with no loss of affinity. This suggested that the binding conformation of the aminoethyl side chain at this receptor was toward the 4-position of the indole ring and was supported by the fact that the 4-(aminoethyl)indoles (45) also displayed high affinity, as did the conformationally rigid 1,3,4,5-tetrahydrobenz[c,d]indole (49). Molecular modeling showed that 19, 43, and 45 all had low-energy conformers that overlaid well onto 49. Both 19 and 49 had good selectivity over other serotonin receptors tested, with 49 also showing excellent selectivity over all dopamine receptors. In a functional adenylate cyclase stimulation assay, 19 and 49 had no agonist activity, whereas 45 behaved as a partial agonist. Finally, it was shown that 19 had good activity in the 5-HT(2A) centrally mediated mescaline-induced head twitch assay, which implies that it is brain-penetrant.
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85 |
20
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Drisko CL, Cobb CM, Killoy WJ, Michalowicz BS, Pihlstrom BL, Lowenguth RA, Caton JG, Encarnacion M, Knowles M, Goodson JM. Evaluation of periodontal treatments using controlled-release tetracycline fibers: clinical response. J Periodontol 1995; 66:692-9. [PMID: 7473012 DOI: 10.1902/jop.1995.66.8.692] [Citation(s) in RCA: 84] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The purpose of this investigation was to evaluate the clinical efficacy of controlled-release tetracycline fiber therapy in adult periodontitis patients. One hundred-twenty-two (122) adult patients from 3 dental centers were enrolled at baseline for this study. each patient provided at least one site in each of four quadrants that was > or = 5 mm and bled on probing. One or two such sites were selected as test sites and were randomly assigned to receive one of four treatments: scaling and root planing (S), scaling and root planing plus tetracycline fiber for 10 days (SF), fiber therapy alone for 10 days (F), or two 10-day serial fiber applications (FF). After treatment, no periodontal maintenance or supportive care was provided until the end of this 12-month study. Probing depth (PD), clinical attachment level (CAL), plaque, and bleeding on probing (BOP) were measured at baseline and at 1, 3, 6, 9, and 12 months following treatment. Repeated PD and CAL measurements were taken at three locations within each site and averaged for each site. One hundred-sixteen (116) subjects completed the study. All treatments resulted in similar improvements in clinical parameters compared to baseline and were equally effective in the treatment of periodontitis as measured by probing depth reduction, clinical attachment level gain, and reduction of bleeding on probing. The clinical response, established primarily by 3 months following therapy, was generally sustained in all treatment groups for 12 months without the benefit of supportive maintenance therapy.
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Clinical Trial |
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21
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di Martino E, L'Hôte CG, Kennedy W, Tomlinson DC, Knowles MA. Mutant fibroblast growth factor receptor 3 induces intracellular signaling and cellular transformation in a cell type- and mutation-specific manner. Oncogene 2009; 28:4306-16. [PMID: 19749790 PMCID: PMC2789045 DOI: 10.1038/onc.2009.280] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Although activating mutations of FGFR3 are frequent in bladder tumors, little information is available on their specific effects in urothelial cells or the basis for the observed mutation spectrum. We investigated the phenotypic and signaling consequences of three FGFR3 mutations (S249C, Y375C, and K652E) in immortalized normal human urothelial cells (TERT-NHUC) and mouse fibroblasts (NIH-3T3). In TERT-NHUC, all mutant forms of FGFR3 induced phosphorylation of FRS2α and ERK1/2, but not AKT or SRC. PLCγ1 phosphorylation was only observed in TERT-NHUC expressing the common S249C and Y375C mutations, and not the rare K652E mutation. Cells expressing S249C and Y375C FGFR3 displayed an increased saturation density, related to increased proliferation and viability. This effect was significantly dependent on PLCγ1 signaling and undetectable in cells expressing K652E FGFR3, which failed to phosphorylate PLCγ1. In contrast to TERT-NHUC, expression of mutant FGFR3 in NIH-3T3 resulted in phosphorylation of Src and Akt. Additionally, all forms of mutant FGFR3 were able to phosphorylate Plcγ1 and induce morphological transformation, cell proliferation, and anchorage independent growth. Our results indicate that the effects of mutant FGFR3 are both cell type- and mutation-specific. Mutant FGFR3 may confer a selective advantage in the urothelium by overcoming normal contact inhibition of proliferation.
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Research Support, Non-U.S. Gov't |
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84 |
22
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Review |
26 |
82 |
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Hornigold N, Devlin J, Davies AM, Aveyard JS, Habuchi T, Knowles MA. Mutation of the 9q34 gene TSC1 in sporadic bladder cancer. Oncogene 1999; 18:2657-61. [PMID: 10353610 DOI: 10.1038/sj.onc.1202854] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Deletions involving chromosome 9 occur in more than 50% of human bladder cancers of all grades and stages. Most involve loss of the whole chromosome or of an entire chromosome arm but some small deletions are found which can be used to define critical regions which may contain tumour suppressor genes. We have localized such a critical region of deletion at 9q34 between the markers D9S149 and D9S66, an interval which contains the Tuberous Sclerosis gene TSC1. Single strand conformation polymorphism (SSCP) and sequence analysis of TSC1 in bladder tumours and cell lines with 9q34 loss of heterozygosity (LOH) has identified five mutations in retained TSC1 alleles. Our results support the hypothesis that TSC1 can act as a bladder tumour suppressor gene.
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81 |
24
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Chapman EJ, Hurst CD, Pitt E, Chambers P, Aveyard JS, Knowles MA. Expression of hTERT immortalises normal human urothelial cells without inactivation of the p16/Rb pathway. Oncogene 2006; 25:5037-45. [PMID: 16619045 DOI: 10.1038/sj.onc.1209513] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The CDKN2A locus is frequently inactivated in urothelial cell carcinoma (UCC), yet how this alteration contributes to bladder tumorigenesis is not known. Although most UCC express telomerase, inactivation of the p16/Rb pathway is generally required for in vitro immortalisation. This and the involvement of p16 in senescence of normal human urothelial cells (NHUC) suggest that CDKN2A deletion may aid bypass of senescence and allow immortalisation. CDKN2A encodes p16 and p14ARF and therefore inactivation of this locus can disrupt both the Rb and p53 tumour suppressor pathways. Retrovirus-mediated transduction was used to specifically modulate the p16/Rb and/or p53 tumour suppressor pathways in NHUC and to express human telomerase reverse transcriptase (hTERT). Expression of hTERT bypassed Rb and p53 pathway-dependent barriers to proliferation and immortalised NHUC. TERT-NHUC had normal karyotypes, were non-tumorigenic and unexpectedly retained CDKN2A. Thus, the phenotypic significance of inactivation of CDKN2A in UCC may not be solely related to bypass of senescence. Phenotypic assays in human urothelial cells have relied on cell strains derived from invasive tumours or NHUC immortalised by expression of SV40-large T. The production of genetically normal but immortal NHUC lines now provides a valuable platform for experiments to examine the timing and combination of events necessary for UCC tumorigenesis.
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Journal Article |
19 |
80 |
25
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Sibley K, Cuthbert-Heavens D, Knowles MA. Loss of heterozygosity at 4p16.3 and mutation of FGFR3 in transitional cell carcinoma. Oncogene 2001; 20:686-91. [PMID: 11314002 DOI: 10.1038/sj.onc.1204110] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2000] [Revised: 10/31/2000] [Accepted: 11/13/2000] [Indexed: 01/06/2023]
Abstract
4p16.3 has previously been identified as a region of non-random LOH in transitional cell carcinoma, suggesting the presence of a tumour suppressor gene. One candidate within this region is fibroblast growth factor receptor 3 (FGFR3). Germline mutations in FGFR3 are known to cause several autosomal dominant skeletal dysplasias, the severity of which depends on the position and nature of the mutation in the protein. We investigated the frequency and nature of FGFR3 mutations in a panel of transitional cell carcinomas and cell lines and studied the possible link between mutation and loss of heterozygosity (LOH) on 4p16.3. FGFR3 coding sequence from 63 transitional cell carcinomas (TCC) of various stages and grades, and 18 cell lines was analysed by fluorescent SSCP. Samples with abnormal migration patterns were sequenced to identify the mutation or polymorphism. Thirty-one of the 63 tumours had previously been assessed to have LOH at 4p16.3. Twenty-six of the 63 tumours (41%) and 4/18 (22%) of the cell lines had missense mutations in FGFR3. All mutations detected in our panel have been reported in the germline where all apart from one cause lethal conditions. One tumour contained K652Q which has recently been identified in less severe cases of skeletal dysplasia. Tumours with and without LOH at 4p16.3 had mutations in FGFR3 suggesting that these two events are not causally linked. The frequency of FGFR3 mutation indicates that this protein plays an important role in TCC.
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MESH Headings
- Carcinoma, Transitional Cell/classification
- Carcinoma, Transitional Cell/genetics
- Chromosomes, Human, Pair 4/genetics
- DNA, Neoplasm
- Humans
- Loss of Heterozygosity
- Polymerase Chain Reaction
- Polymorphism, Single-Stranded Conformational
- Protein-Tyrosine Kinases
- Receptor, Fibroblast Growth Factor, Type 3
- Receptors, Fibroblast Growth Factor/genetics
- Sequence Analysis, DNA
- Urinary Bladder Neoplasms/classification
- Urinary Bladder Neoplasms/genetics
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75 |