Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P43146 (tumour suppressor)
 5,935 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Individuals with naevoid basal cell carcinoma (Gorlin) syndrome are at increased risk of developing medulloblastoma in childhood. We have shown that approximately 5% of patients with Gorlin syndrome will develop this complication in the first few years of life, and in addition 10% of patients with medulloblastoma diagnosed at age 2 years or under have Gorlin syndrome. One out of three medulloblastomas occurring in patients with Gorlin syndrome was shown to have lost the wild-type allele on 9q, indicating that the Gorlin locus probably acts as a tumour suppressor in the development of this tumour. We have also confirmed this role in a basal cell carcinoma (BCC) from the same individual. Information from these families would suggest that Gorlin syndrome is more common than previously recognized and may not always be diagnosed on clinical grounds alone even in middle life.
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PMID:The gene for the naevoid basal cell carcinoma syndrome acts as a tumour-suppressor gene in medulloblastoma. 923 11

Mutations of the human Patched gene ( PTCH ) have been identified in individuals with the nevoid basal cell carcinoma syndrome (NBCCS) as well as in sporadic basal cell carcinomas and medulloblastomas. We have isolated a homologue of this tumour suppressor gene and localized it to the short arm of chromosome 1 (1p32.1-32.3). Patched 2 ( PTCH2 ) comprises 22 coding exons and spans approximately 15 kb of genomic DNA. The gene encodes a 1203 amino acid putative transmembrane protein which is highly homologous to the PTCH product. We have characterized the genomic structure of PTCH2 and have used single-stranded conformational polymorphism analysis to search for mutations in PTCH2 in NBCCS patients, basal cell carcinomas and in medulloblastomas. To date, we have identified one truncating mutation in a medulloblastoma and a change in a splice donor site in a basal cell carcinoma, suggesting that the gene plays a role in the development of some tumours.
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PMID:Isolation and characterization of human patched 2 (PTCH2), a putative tumour suppressor gene inbasal cell carcinoma and medulloblastoma on chromosome 1p32. 993 36

Increasing evidence has accumulated for an involvement of the inactivation of tumour suppressor genes at chromosome 10q in the carcinogenesis of brain tumours, melanomas, and carcinomas of the lung, the prostate, the pancreas, and the endometrium. The gene DMBT1 (Deleted in Malignant Brain Tumours 1) is located at chromosome 10q25.3-q26.1, within one of the putative intervals for tumour suppressor genes. DMBT1 is a member of the scavenger-receptor cysteine-rich (SRCR) superfamily and displays homozygous deletions or lack of expression in glioblastoma multiforme, medulloblastoma, and in gastrointestinal and lung cancers. Based on these properties, DMBT1 has been proposed to be a candidate tumour suppressor gene. We have determined the genomic sequence of DMBT1 to allow analyses of mutations. The gene has at least 54 exons that span a genomic region of about 80 kb. We have identified a putative exon with coding potential for a transmembrane domain. Our data further suggest that alternative splicing gives rise to isoforms of DMBT1 with a differential utilization of SRCR domains and SRCR interspersed domains. The major part of the gene harbours locus specific repeats. These repeats may point to the DMBT1 locus as a region susceptible to chromosomal instability.
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PMID:The genomic structure of the DMBT1 gene: evidence for a region with susceptibility to genomic instability. 1059 21

Basal cell carcinoma, medulloblastoma, rhabdomyosarcoma and other human tumours are associated with mutations that activate the proto-oncogene Smoothened (SMO) or that inactivate the tumour suppressor Patched (PTCH). Smoothened and Patched mediate the cellular response to the Hedgehog (Hh) secreted protein signal, and oncogenic mutations affecting these proteins cause excess activity of the Hh response pathway. Here we show that the plant-derived teratogen cyclopamine, which inhibits the Hh response, is a potential 'mechanism-based' therapeutic agent for treatment of these tumours. We show that cyclopamine or synthetic derivatives with improved potency block activation of the Hh response pathway and abnormal cell growth associated with both types of oncogenic mutation. Our results also indicate that cyclopamine may act by influencing the balance between active and inactive forms of Smoothened.
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PMID:Effects of oncogenic mutations in Smoothened and Patched can be reversed by cyclopamine. 1098 33

Hedgehog signalling is a key regulator of embryonic development controlling proliferation and/or cell fate determination. With identification of the Hedgehog receptor PTCH1 as a tumour suppressor gene that underlies the human nevoid basal cell carcinoma syndrome (NBCCS), the Hedgehog signalling pathway was firmly linked to cancer. It now appears that constitutive activation of Hedgehog signalling, by inactivating mutations in PTCH1 or activating mutations in the coreceptor SMOH, is required and possibly sufficient for basal cell carcinoma development and also contributes to the formation of a variety of other tumour types, including medulloblastoma and rhabdomyosarcoma. Several lines of evidence, including transgenic mice experiments, suggest that the critical cellular effect is stimulation of proliferation mediated by the transcriptional effector GLI1. Additional components of the signal transduction machinery as well as essential target genes remain to be identified, and involvement of the Hedgehog signalling pathway in other tumour types and/or hereditary cancer predisposition syndromes is to be expected.
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PMID:Hedgehog signalling in cancer. 1113 Jan 78

Deregulation of apoptosis has been implicated in the pathogenesis, spontaneous regression and treatment resistance of neuroblastoma. A newly recognised member of the tumour necrosis factor (TNF)-family of death receptors known as Apo-3 has been mapped to human chromosome 1p36.3, a region commonly deleted in aggressive neuroblastoma. Based on its localisation and function, Apo-3 is a candidate for the putative neuroblastoma tumour suppressor gene. Therefore we analysed mRNA expression of the Apo-3 receptor/ligand (Apo-3/Apo-3L) system in a representative panel of 18 neuroblastoma cell lines, 41 primary neuroblastoma and 13 ganglioneuromas/ganglioneuroblastomas by semi-quantitative RT-PCR. We compared the level of expression with the well-established prognostic factors age, stage, histology, MYCN-amplification and TrkA expression, as well as outcome. For comparison, we studied Apo-3/Apo-3L expression in 27 central nervous system (CNS) primitive neuroectodermal tumours/medulloblastomas (PNET/medulloblastoma) and in six normal brain samples. Neuroblastoma cell lines with 1p deletion and MYCN-amplification expressed significantly lower levels of Apo-3 (P=0.009 and P=0.03, respectively) compared with neuroblastoma cell lines without 1p deletion or MYCN-amplification. The mean expression level of Apo-3L was significantly higher in ganglioneuromas/ganglioneuroblastomas compared with neuroblastomas (P=0.001) and in normal brain compared with PNET/medulloblastoma (P<0.0001). Expression of Apo-3L was significantly associated with survival in neuroblastomas (P<0.049) and in PNET/medulloblastomas (P=0.01). Expression of Apo-3 was significantly associated with survival in PNET/medulloblastomas (P=0.03). Thus, the Apo-3 receptor/ligand system might be involved in the regulation of apoptosis in neuroblastomas and PNET.
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PMID:Expression of Apo-3 and Apo-3L in primitive neuroectodermal tumours of the central and peripheral nervous system. 1175 Aug 45

Medulloblastomas (MBs) are malignant primitive neuroectodermal tumours (PNETs) of the cerebellum occurring predominantly in childhood. The association of monosomy of chromosome 22 with MB is controversial. Atypical teratoid/rhabdoid tumours (AT/RTs) of the brain share clinical and histological features with MBs and supratentorial PNETs (sPNETs). In particular, AT/RTs can be misdiagnosed as MBs and sPNETs because AT/RTs frequently contain areas of primitive neuroepithelial cells similar to PNETs. Recently, mutations of the tumour suppressor gene hSNF5/INI1, located on 22q11.23, have been described in AT/RTs, MBs and sPNETs, with conflicting data on the prevalence of hSNF5/INI1 mutations in the latter entities. Therefore, we screened MBs for point mutations and homozygous deletions of the hSNF5/INI1 tumour suppressor gene. In 90 MBs, no mutations of the hSNF5/INI1 gene were identified. Thus, our study virtually rules out hSNF5/INI1 as a tumour suppressor gene involved in the pathogenesis of medulloblastoma.
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PMID:Human medulloblastomas lack point mutations and homozygous deletions of the hSNF5/INI1 tumour suppressor gene. 1197

Mutations affecting the transmembrane proteins Patched (Ptc) or Smoothened (Smo) that trigger ligand-independent activity of the Hedgehog (Hh) signalling pathway are associated with human tumours such as basal cell carcinoma (BCC) and medulloblastoma. Despite extensive genetic studies demonstrating the importance of these receptor components in embryonic patterning and cancer, the mechanism by which Ptc regulates Smo is not understood. Here we report that Ptc and Smo are not significantly associated within Hh-responsive cells. Furthermore, we show that free Ptc (unbound by Hh) acts sub-stoichiometrically to suppress Smo activity and thus is critical in specifying the level of pathway activity. Patched is a twelve-transmembrane protein with homology to bacterial proton-driven transmembrane molecular transporters; we demonstrate that the function of Ptc is impaired by alterations of residues that are conserved in and required for function of these bacterial transporters. These results suggest that the Ptc tumour suppressor functions normally as a transmembrane molecular transporter, which acts indirectly to inhibit Smo activity, possibly through changes in distribution or concentration of a small molecule.
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PMID:Patched acts catalytically to suppress the activity of Smoothened. 1219 14

Chromosome 9 alterations are the most frequently encountered cytologic anomalies in urothelial carcinoma (UC). We previously screened 139 low-stage UCs for loss of heterozygosity on chromosome 9, and identified five distinct regions likely to harbour tumour-suppressor genes. The present study focused on deletion mapping in the 9q22 region with 11 additional microsatellite markers. New deletions in the 9q22 region were found in five tumours. Deletion mapping allowed us to identify a 0.5 CM common minimal region of deletion between markers D9S280 and D9S1809, encompassing PATCHED (PTC), a gene identified as a tumour suppressor in basal cell carcinoma and in medulloblastoma. A marker located in the first intron of this gene showed the highest percentage of deletion (45%). cDNA sequencing in 15 tumours with deletion of PTC showed no mutation in the remaining allele. However, average expression of PTC mRNA measured by semiquantitative RT-PCR was significantly decreased in tumours with LOH in the 9q22 region, compared to normal urothelium (P=0.04), while it showed marked fluctuations in tumours without deletion. Our results suggest that the PTC gene is a putative suppressor at the 9q22 locus and that haploinsufficiency of this gene may be an early event in the development of papillary bladder tumours.
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PMID:Alteration of the PATCHED locus in superficial bladder cancer. 1277 48

Haploinsufficiency of the human 17p13.3 region is associated with 35% to 50% of medulloblastomas, indicating the presence of one or more tumour suppressor genes which have not yet been identified. Of 119 genes residing in this region, seven genes--14-3-3epsilon (YWHAE), HIC-1, ROX/MNT (a helix-loop-helix transcription factor and member of the MYC/MAX superfamily), KIAA0399, UBE2G1 (ubiquitin ligase), ALOX15, and MINK--encode proteins with potential links to cancer. We investigated these genes and found significant levels of expression of ROX/MNT in adult human cerebellum, and in embryonic and postnatal mouse cerebellum. Six of 14 medulloblastomas showed a reduction of ROX/MNT expression, accompanied by a reduction of both UBE2G1 and 14-3-3epsilon in three tumours and a reduction of UBE2G1 in one tumour. Moreover, the relative expression of MYC to ROX/MNT was increased in 4 of the 14 medulloblastomas. Collectively, these data suggest that ROX/MNT should be considered a potential tumour suppressor gene in medulloblastoma.
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PMID:Analysis of transcripts from 17p13.3 in medulloblastoma suggests ROX/MNT as a potential tumour suppressor gene. 1551 29


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