So far, no common environmental and/or phenotypic factor has been associated with melanoma and renal cell carcinoma (RCC). The known risk factors for melanoma include sun exposure, pigmentation and nevus phenotypes; risk factors associated with RCC include smoking, obesity and hypertension. A recent study of coexisting melanoma and RCC in the same patients supports a genetic predisposition underlying the association between these two cancers. The microphthalmia-associated transcription factor (MITF) has been proposed to act as a melanoma oncogene; it also stimulates the transcription of hypoxia inducible factor (HIF1A), the pathway of which is targeted by kidney cancer susceptibility genes. We therefore proposed that MITF might have a role in conferring a genetic predisposition to co-occurring melanoma and RCC. Here we identify a germline missense substitution in MITF (Mi-E318K) that occurred at a significantly higher frequency in genetically enriched patients affected with melanoma, RCC or both cancers, when compared with controls. Overall, Mi-E318K carriers had a higher than fivefold increased risk of developing melanoma, RCC or both cancers. Codon 318 is located in a small-ubiquitin-like modifier (SUMO) consensus site (ΨKXE) and Mi-E318K severely impaired SUMOylation of MITF. Mi-E318K enhanced MITF protein binding to the HIF1A promoter and increased its transcriptional activity compared to wild-type MITF. Further, we observed a global increase in Mi-E318K-occupied loci. In an RCC cell line, gene expression profiling identified a Mi-E318K signature related to cell growth, proliferation and inflammation. Lastly, the mutant protein enhanced melanocytic and renal cell clonogenicity, migration and invasion, consistent with a gain-of-function role in tumorigenesis. Our data provide insights into the link between SUMOylation, transcription and cancer.
Background-TGFBR2 mutations were recognized recently among patients with a Marfan-like phenotype. The associated clinical and prognostic spectra remain unclear. Methods and Results-Clinical features and outcomes of 71 patients with a TGFBR2 mutation (TGFBR2 group) were compared with 50 age-and sex-matched unaffected family members (control subjects) and 243 patients harboring FBN1 mutations (FBN1 group). Aortic dilatation was present in a similar proportion of patients in both the TGFBR2 and FBN1 groups (78% versus 79%, respectively) but was highly variable. The incidence and average age for thoracic aortic surgery (31% versus 27% and 35Ϯ16 versus 39Ϯ13 years, respectively) and aortic dissection (14% versus 10% and 38Ϯ12 versus 39Ϯ9 years) were also similar in the 2 groups. Mitral valve involvement (myxomatous, prolapse, mitral regurgitation) was less frequent in the TGFBR2 than in the FBN1 group (all PϽ0.05). Aortic dilatation, dissection, or sudden death was the index event leading to genetic diagnosis in 65% of families with TGFBR2 mutations, versus 32% with FBN1 mutations (Pϭ0.002). The rate of death was greater in TGFBR2 families before diagnosis but similar once the disease had been recognized. Most pregnancies were uneventful (without death or aortic dissection) in both TGFBR2 and FBN1 families (38 of 39 versus 213 of 217; Pϭ1). Seven patients (10%) with a TGFBR2 mutation fulfilled international criteria for Marfan syndrome, 3 of whom presented with features specific for Loeys-Dietz syndrome. Conclusions-Clinical
We show that functional analysis using a splicing reporter minigene is sensitive and specific, and should be used for initial screening of potential splicing defects, especially when patient RNA is not readily available.
To evaluate the effect of adjuvant chemotherapy in patients with local-regional nasopharyngeal carcinoma (NPC) (squamous or undifferentiated) in complete remission at the end of curative radiotherapy (RT) 229 patients were randomized from 1979 to 1983 in a multicenter study to no further therapy (116 patients) or a combination of vincristine, cyclophosphamide, and Adriamycin (doxorubicin; Adria Laboratories, Columbus, OH) (VCA) for six monthly cycles (113 patients). The RT and RT + VCA groups were well balanced for median age (50 v 49 years), histology (undifferentiated carcinoma, 73% v 70%), tumor extent (tumor limited to nasopharynx, 57% v 57%), and nodal extent (negative nodes 26% v 24%, nodes in the lower cervical levels, 17% v 16%). RT was delivered to the nasopharynx, the base of the skull, and bilateral cervical nodes using a split course technique over 10 weeks up to the dose of 60 to 70 Gy in involved sites and 50 Gy to negative nodes. Response to RT was evaluated within 65 days post-RT treatment. Analysis at 48 months did not show significant difference between the two treatment groups in terms of relapse-free survival (RT, 55.8%, RT + VCA, 57.7%, P = .45) and overall survival (RT, 67.3%, RT + VCA, 58.5%, P = .13). The pattern of relapse was similar in the two treatment arms. Distant metastases were the cause of treatment failure in about 50% of relapsing patients. Although the results of the present study did not show any benefit from VCA administered after curative RT, combined systemic chemotherapy should be further explored due to the high incidence of local and distant failure after intensive RT.
Mutations of the ryanodine receptor cause dominant and recessive forms of congenital myopathies with cores. Quantitative defects of RYR1 have been reported in families presenting with recessive forms of the disease and epigenic regulation has been recently proposed to explain potential maternal monoallelic silencing of the RYR1 gene. We investigated nine families presenting with a recessive form of the disease and showing a quantitative defect of RYR1 expression. Genetic analysis allowed the identification of a mutation on both alleles of the RYR1 gene for all patients, 15 being novel variants. We evidenced for all patients an alteration of the expression of the RYR1 gene caused by amorphic mutations responsible either for mRNA or protein instability. In seven families the variant present on the second allele was a missense mutation. In the remaining two families the second variant led to a hypomorphic expression of the RYR1 gene and was associated with a severe neonatal phenotype, pointing out the minimal amount of RYR1 needed for skeletal muscle function. Noticeably, a novel additional exon 3b was characterized in the most severely affected cases. This study showed that all cases presenting with a quantitative defect of RYR1 expression in our panel of patients affected by recessive core myopathies were caused by the presence of one recessive null allele and that variability of the phenotype depended on the nature of the mutation present on the second allele. Our study also indicated that presence of a second mutation must be investigated in sporadic cases or in dominant cases presenting with a familial clinical variability.
Genetic linkage data have shown that alterations of the BRCA1 gene are responsible for the majority of hereditary breast-ovarian cancers. However, BRCA1 germline mutations are found much less frequently than expected, especially as standard PCR-based mutation detection approaches focus on point and small gene alterations. In order to estimate the contribution of large gene rearrangements to the BRCA1 mutation spectrum, we have extensively analysed a series of 120 French breast-ovarian cancer cases. Thirty-eight were previously found carrier of a BRCA1 point mutation, 14 of a BRCA2 point mutation and one case has previously been reported as carrier of a large BRCA1 deletion. The remaining 67 cases were studied using the BRCA1 bar code approach on combed DNA which allows a panoramic view of the BRCA1 region. Three additional rearrangements were detected: a recurrent 23.8 kb deletion of exons 8 -13, a 17.2 kb duplication of exons 3 -8 and a 8.6 kb duplication of exons 18 -20. Thus, in our series, BRCA1 large rearrangements accounted for 3.3% (4/120) of breast-ovarian cancer cases and 9.5% (4/42) of the BRCA1 gene mutation spectrum, suggesting that their screening is an important step that should be now systematically included in genetic testing surveys.
This study enables us to estimate the frequency of the SPG3A mutations in France at 39% in families with young-onset autosomal dominant spastic paraplegia after exclusion of SPG4 cases. So far, most mutations have been private, although they were all found in exons 7, 8, 12, and 13. These exons should be given priority when performing molecular diagnoses for SPG3A.
The t(14;18)(q32;q21) chromosomal translocation is observed in more than 75% of cases of follicular lymphoma. Several additional chromosomal abnormalities, which might contribute to tumor progression, have also been described. However, prognostic implications of cytogenetic features in follicular lymphoma have not been clearly established. In an attempt to correlate cytogenetic findings with clinical outcome, we have studied survival and risk of transformation into a more aggressive lymphoma in 66 follicular lymphoma patients from whom a lymph node had been karyotyped at the time of diagnosis. A t(14;18) was the most common abnormality, having been observed in 51 patients (77%), but this showed no correlation with clinical outcome. Seventeen other recurrent numerical or structural abnormalities were identified in more than 10% of the patients. A high percentage of cells (> or = 90%) with abnormal metaphases and a number of chromosomal breaks higher than 6 were associated with a poor survival (P > .01 each). Patients with an abnormality of chromosome region 1p21–22 (P < .01), of 6q23–26 (P < .001), or of the short arm of chromosome 17 (P < .001) had a significantly shorter survival in univariate analysis. Multivariate analysis identified a break at 6q23–26 (P = .01) and 17p (P = .01) as independent prognostic factors in this population. The risk of transformation into a diffuse large-cell lymphoma was significantly higher in patients with either a 6q23–26 (P < .001) or a 17p (P < .01) abnormality. Chromosomal analysis of follicular lymphoma at the time of diagnosis can thus provide important information about the risk of transformation and survival.(ABSTRACT TRUNCATED AT 250 WORDS)
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