RESUMEN
We have found a 33 bp minisatellite repeat in the 5'-flanking region of the mutated in colon cancer (MCC) gene at chromosome 5q21. Southern blot experiments demonstrated the locus specificity of the repeat. The number of repeat units varied between 5 and 11 with a heterozygosity of 0.56. The sequence 5'-AGG AGT GTG AAT GGG GCA TAG TGA ATG AGG GGA-3' of the repeat units does not match the consensus sequence of chi-related minisatellites. The minisatellite is not expressed as part of a gene transcription unit. However, it can be used as a tool for the detection of allelic changes at chromosome 5q21 on standard agarose gels.
Asunto(s)
Cromosomas Humanos Par 5 , Neoplasias del Colon/genética , Repeticiones de Microsatélite , Proteínas/genética , Proteínas Supresoras de Tumor , Secuencia de Bases , Mapeo Cromosómico , Expresión Génica , Humanos , Datos de Secuencia Molecular , Polimorfismo GenéticoRESUMEN
The genetics of renal cell tumors (RCT), which occur at a high frequency in patients with end-stage renal failure (ESRF), is not yet known. Using a fluorescence microsatellite assay and comparative genomic hybridization, 18 renal tumors obtained from nine patients with ESRF were analyzed for genetic alterations, which are known to be characteristic of common nonpapillary and papillary RCT in the general population. Deletion of chromosome 3p was detected in six nonpapillary tumors, whereas trisomies of 7 and 17 or 3, 8, and 16 were seen in four of 18 tumors. No alterations were found in four tumors, and another four tumors had unspecific changes. The fragile histidine triad (FHIT) gene is localized at the most common fragile site at chromosome 3p14.2. The FHIT and the p53 tumor suppressor gene are targets of different environmental agents. Because both toxic effect and genomic instability are implicated in the development of renal cysts in ESRF, the alteration of both genes in tumor cells was analyzed. No abnormal expression of the FHIT gene or mutation of the p53 gene were found. This study suggests that the genetics and also the morphology of some of the ESRF RCT differ from those known for RCT in the general population.
Asunto(s)
Ácido Anhídrido Hidrolasas , Fallo Renal Crónico/complicaciones , Neoplasias Renales/complicaciones , Neoplasias Renales/genética , Proteínas de Neoplasias , Adulto , Anciano , Mapeo Cromosómico , Exones/genética , Femenino , Genes p53/genética , Humanos , Neoplasias Renales/patología , Pérdida de Heterocigocidad/genética , Masculino , Repeticiones de Microsatélite/genética , Persona de Mediana Edad , Familia de Multigenes/genética , Mutación/genética , Proteínas/genéticaRESUMEN
We examined 88 nonpapillary renal cell carcinomas for allelic loss at chromosome arm 14q and correlated the results to size, grade, and stage of these tumors. Fourteen highly polymorphic microsatellite markers on the long arm of chromosome 14 were used for deletion mapping. Loss of heterozygosity (LOH) at the smallest overlapping segment of 14q24.2-qter was seen in 42 of 88 tumors. There was no significant correlation between frequency of 14q LOH and size of tumors (P = 0.11). LOH was frequently seen in grade 2 and 3 tumors (55% and 73%, respectively) and in stage III and IV tumors (53% and 80%, respectively). We found a significant correlation between chromosome arm 14q LOH and nuclear grade (P < 0.001) and stage (P < 0.001) of tumors. These observations indicate the presence of a tumor-suppressor gene at chromosome segment 14q24.2-qter and demonstrate the usefulness of microsatellite analysis for assessing the possible clinical outcome of nonpapillary renal cell carcinomas.
Asunto(s)
Carcinoma de Células Renales/genética , Deleción Cromosómica , Cromosomas Humanos Par 14 , Neoplasias Renales/genética , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma de Células Renales/patología , Células Cultivadas , Mapeo Cromosómico , Femenino , Heterocigoto , Humanos , Neoplasias Renales/patología , Masculino , Repeticiones de Microsatélite , Persona de Mediana Edad , Estadificación de NeoplasiasRESUMEN
Previous karyotyping showed an unbalanced translocation between chromosome 3p11.2-p13 and chromosome 5q22 leading to duplication of chromosome 5q22-qter region in nonpapillary renal cell carcinomas. In order to determine the breakpoint at chromosome 5q22 at the molecular level, we have investigated 50 sporadic nonpapillary renal cell carcinomas from consecutive nephrectomies and 24 renal cell carcinomas obtained from two patients with von Hippel-Lindau disease. We used seven DNA markers mapped to and around the APC and MCC genes to detect allelic imbalance. We observed a duplication of chromosome 5q sequences in 11 of 23 informative sporadic tumours and in 18 of 24 hereditary tumours. We determined a breakpoint cluster between the APC and MCC genes at chromosome 5q22. In addition we have found a partial duplication of the smallest overlapping region of about 1.5 Mb sequences including the MCC gene in seven tumours without visible alteration of chromosome 5q in the karyotype. We suggest that this DNA segment harbours a gene or gene cluster, the altered dosage of which is important for the growth of nonpapillary renal cell carcinomas.
Asunto(s)
Carcinoma de Células Renales/genética , Cromosomas Humanos Par 5 , Neoplasias Renales/genética , Familia de Multigenes , Proteínas Supresoras de Tumor , Southern Blotting , Rotura Cromosómica , Reordenamiento Génico , Genes APC/genética , Marcadores Genéticos , Humanos , Hibridación in Situ , Microscopía Fluorescente , Proteínas/genética , Translocación Genética , Enfermedad de von Hippel-Lindau/genéticaRESUMEN
Our previous cytogenetic and microsatellite analyses showed a terminal deletion of chromosome 3p segments with a breakpoint region between 3p11.2 and 3p14.1 bands in 98% of non-papillary renal cell carcinomas (RCC). This breakpoint region covers approx. 20-25 cM genetic distance. Earlier, we found a higher frequency of rearrangements at chromosome 3p11.2 and have therefore now analyzed 74 sporadic and 26 VHL-associated RCCs with 6 polymorphic microsatellite markers mapped to this region. Thirty-three per cent of the breakpoints were mapped to a genetic distance of less than one-twentieth of the large breakpoint region 3p11.2-14.1. We suggest that unstable DNA sequences at chromosome 3p11.2 serve as a genetic basis for deletions and homologous and non-homologous recombinations to remove distal 3p sequences with one copy of RCC gene(s) in different types of tumors. We have identified a YAC clone 909d5 that spans the most frequently occurring breaks between loci D3S1251, D3S1101, and D3S1552 and allows this region to be cloned.
Asunto(s)
Carcinoma de Células Renales/genética , Cromosomas Humanos Par 3/genética , Proteínas de Unión al ADN/genética , Neoplasias Renales/genética , Carcinoma de Células Renales/patología , Mapeo Cromosómico/métodos , ADN de Neoplasias/química , ADN Satélite/química , Eliminación de Gen , Marcadores Genéticos/genética , Heterocigoto , Humanos , Neoplasias Renales/patología , Reacción en Cadena de la Polimerasa/métodos , Células Tumorales CultivadasRESUMEN
To define the possible role of the VHL gene in the development of sporadic renal cell carcinomas, 91 different parenchymal tumours of the kidney have been investigated for mutation of the VHL gene by single strand conformation polymorphism (SSCP) and/or heteroduplex (HD) techniques. Chromosome 3p deletion was detected in 98 per cent of non-papillary renal cell carcinomas and in 25 per cent of chromophobe renal cell carcinomas. In 22 of the 43 non-papillary renal cell carcinomas, abnormally migrating DNA bands were detected by SSCP and/or HD analysis. No mobility shift was seen in any of the 23 chromophobe renal cell carcinomas. In addition, 15 papillary renal cell tumours and ten renal oncocytomas, which are characterized by genetic changes other than loss of chromosome 3p sequences, were analysed for mutation of the VHL gene. None of these tumours showed abnormal migration patterns. The results indicate that mutation of the VHL gene is associated exclusively with the development of non-papillary renal cell carcinoma.
Asunto(s)
Carcinoma de Células Renales/genética , Neoplasias Renales/genética , Mutación/genética , Enfermedad de von Hippel-Lindau/genética , Secuencia de Bases , Deleción Cromosómica , Cromosomas Humanos Par 3/genética , Humanos , Datos de Secuencia Molecular , Ácidos Nucleicos Heterodúplex/genética , Polimorfismo Conformacional Retorcido-Simple , Análisis de Secuencia de ADNRESUMEN
Deletion of chromosome 3p13-pter sequences is a specific genetic change in nonpapillary renal cell carcinomas (RCC). The VHL gene, a putative tumor suppressor gene, has already been cloned from the 3p25-26 chromosomal region. Conflicting cytogenetic and RFLP studies, however, suggest multiple interstitial deletions and additional tumor suppressor genes at chromosome 3p. To investigate the loss of DNA sequences on chromosome 3p in nonpapillary RCCs, we analyzed 41 paired normal and tumor DNAs obtained from short-term cultures of pure tumor cells with 12 polymorphic microsatellite markers covering the 3p11.2-p25 region. Deletion mapping provided evidence for terminal deletion with the most distal breakpoint between D3S1300 and D3S1285 loci, which is the site of breakpoint in familial 3;8 translocation predisposing to nonpapillary RCC. All breakpoints, including those occurring in familial translocation 3;6, were clustered in a more than 20-cM-large region between loci D3S1285 and D3S1603. Interestingly, 7 of the 28 cases with 3p deletion showed a recurrent breakpoint between D3S1603 and D3S1595, which cover about 1 cM genetic distance. The results suggest that a tumor suppressor gene, in addition to the VHL gene, might be localized somewhere on chromosome 3p distal to the familial 3;8 translocation, or it might be at the breakpoint cluster. Alternatively, the breakpoint serves as a mechanism to lose distal DNA sequences.