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- Johannsdottir, HK, et al.
(författare)
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Deletions on chromosome 4 in sporadic and BRCA mutated tumors and association with pathological variables
- 2004
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Ingår i: Anticancer research. - 1791-7530. ; 24:5A, s. 2681-2687
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Tidskriftsartikel (refereegranskat)abstract
- Background: Chromosomal aberrations in breast tumors from BRCA1 and BRCA2 germ-line mutation carriers are considerably more frequent than what is seen in sporadic breast tumors. According to Comparative Genomic Hybridisation analysis (CGH), deletions on chromosome 4 are one of the most frequent events in BRCA1-associated tumors, suggesting inactivation of specific tumor suppressor genes. Materials and Methods: In the present study, 16 microsatellite markers covering chromosome 4 were used to map loss of heterozygosity (LOH) in tumors from BRCA1 (n =41) as well as in tumors from BRCA2 (n = 66) mutation carriers and in tumors from unselected cases of breast cancer (n = 68). Results: The frequency of LOH in these groups ranged from 16-73% in BRCA1-associated tumors, 13-42% in BRCA2-associated tumors and 8-33% in unselected tumors. LOH was significantly more frequent in BRCA1-associated tumors as compared to BRCA2-associated tumors and unselected tumors, and particularly high (over 70%) at 4q35.2. Pathological variables that were found significantly associated (pless than or equal to0.05) with LOH at specific markers were: high percentage of cells in S-phase, negative estrogen receptor status, young age at diagnosis and large tumors. Deletion mapping indicates the existence of seven non-overlapping regions at chromosome 4, which were identified in all three groups of tumors. Three of these seven regions, 4p16.3-p16.1, 4q27-q32.1 and 4q35.1-4qter, have not been reported in breast cancer previously. Conclusion: The results manifest the frequent alterations of chromosome 4 in BRCA1-associated breast tumors and indicate the location of several genes of potential importance in breast cancer development.
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| 2. |
- Krop, I, et al.
(författare)
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Lack of HIN-1 methylation in BRCAl-linked and "BRCA1-like" breast tumors
- 2003
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Ingår i: Cancer Research. - 1538-7445 .- 0008-5472. ; 63:9, s. 2024-2027
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Tidskriftsartikel (refereegranskat)abstract
- We recently identified a candidate tumor suppressor gene, HIN-1, that is silenced due to methylation in the majority of sporadic breast carcinomas and is localized to 5q33-qter, an area frequently lost in BRCA1 tumors and thought to harbor a BRCA1 modifier gene. To establish whether germ-line mutations in HIN-1 may influence breast cancer risk, we sequenced the HIN-1 coding region in 10 familial breast cancer patients with positive logarithm of the odds scores of at least one of the markers flanking HIN-1. We also sequenced the HIN-1 coding region in 15 BRCA1 and 35 sporadic breast tumors to determine whether HIN-1 is the target of the frequent 5q loss in BRCA1 tumors. No sequence alterations were found in any of the cases analyzed. However, analysis of HIN-1 promoter methylation status revealed that in striking contrast to sporadic cases, there is a nearly complete lack of HIN-1 methylation in BRCA1 tumors (P < 0.0001). Sporadic breast tumors with a "BRCA1-like" histopathological phenotype also demonstrated significantly lower frequency of HIN-1 promoter methylation (P = 0.01) compared with other cancer types, and there was also a difference among tumors based on their estrogen receptor and HER2 status (P = 0.006), suggesting that HIN-1 methylation patterns are associated with specific breast cancer subtypes.
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| 3. |
- Rozenblum, E, et al.
(författare)
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A genomic map of a 6-Mb region at 13q21-q22 implicated in cancer development: identification and characterization of candidate genes
- 2002
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Ingår i: Human Genetics. - : Springer Science and Business Media LLC. - 1432-1203 .- 0340-6717. ; 110:2, s. 111-121
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Tidskriftsartikel (refereegranskat)abstract
- Chromosomal region 13q21-q22 harbors a putative breast cancer susceptibility gene and has been implicated as a common site for somatic deletions in a variety of malignant tumors. We have built a complete physical clone contig for a region between D13S1308 and AFM220YE9 based on 18 yeast artificial chromosome and 81 bacterial artificial chromosome (BAC) clones linked together by 22 genetic markers and 61 other sequence tagged sites. Combining data from 47 sequenced BACs (as of June 2001), we have assembled in silico an integrated 5.7-Mb genomic map with 90% sequence coverage. This area contains eight known genes, two hypothetical proteins, 24 additional Unigene clusters, and approximately 100 predicted genes and exons. We have determined the cDNA and genomic sequence, and tissue expression profiles for the KIAA1008 protein (homologous to the yeast mitotic control protein dis3+), KLF12 (AP-2 repressor), progesterone induced blocking factor 1, zinc finger transcription factor KLF5, and LIM domain only-7, and for the hypothetical proteins FLJ22624 and FLJ21869. Mutation screening of the five known genes in 19 breast cancer families has revealed numerous polymorphisms, but no deleterious mutations. These data provide a basis and resources for further analyses of this chromosomal region in the development of cancer.
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