| 1. |
- Adamovic, Tatjana, 1974, et al.
(författare)
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Nonrandom pattern of chromosome aberrations in 17beta-estradiol-induced rat mammary tumors: indications of distinct pathways for tumor development.
- 2007
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Ingår i: Genes, chromosomes & cancer. - : Wiley. - 1045-2257 .- 1098-2264. ; 46:5, s. 459-69
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Tidskriftsartikel (refereegranskat)abstract
- Estrogens play an important role in breast cancer etiology and the ACI rat provides a novel animal model for defining the mechanisms through which estrogens contribute to mammary cancer development. In crossing experiments between the susceptible ACI strain and two resistant strains, COP (Copenhagen) and BN (Brown Norway), several quantitative trait loci (QTL) that affect development of 17beta-estradiol (E2)-induced mammary tumors have been defined. Using comparative genomic hybridization (CGH), we have analyzed cytogenetic aberrations in E2-induced mammary cancers and have found clear patterns of nonrandom chromosomal involvement. Approximately two thirds of the tumors exhibited copy number changes. Losses of rat chromosome 5 (RNO5) and RNO20 were particularly common, and it was found that these two aberrations often occurred together. A third recurrent aberration involving proximal gain and distal loss in RNO6 probably defined a distinct subgroup of tumors, since it never occurred in combination with RNO5 loss. Interestingly, QTL with powerful effects on mammary cancer development have been mapped to RNO5 and RNO6. These findings suggest that there were at least two genetic pathways to tumor formation in this rat model of E2-induced mammary cancer. By performing CGH on mammary tumors from ACI rats, F1 rats from crosses between the ACI and COP or BN strains and ACI.BN-Emca8 congenic rats, which carry the BN allele of the Emca8 QTL on RNO5 on the ACI genetic background, we were able to determine that the constitution of the germ line influences the pattern of chromosomal aberrations.
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| 2. |
- Adamovic, Tatjana, 1974, et al.
(författare)
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Oncogene amplification in the proximal part of chromosome 6 in rat endometrial adenocarcinoma as revealed by combined BAC/PAC FISH, chromosome painting, zoo-FISH, and allelotyping.
- 2005
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Ingår i: Genes, chromosomes & cancer. - : Wiley. - 1045-2257 .- 1098-2264. ; 44:2, s. 139-53
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Tidskriftsartikel (refereegranskat)abstract
- The inbred BDII rat is a valuable experimental model for the genetic analysis of endometrial adenocarcinoma (EAC). One common aberration detected by comparative genomic hybridization in rat EAC was gain/amplification affecting the proximal part of rat chromosome 6 (RNO6). We applied rat and mouse chromosome painting probes onto tumor cell metaphase preparations in order to detect and characterize gross RNO6 aberrations. In addition, the RNO6q11-q16 segment was analyzed by fluorescence in situ hybridization with probes representing 12 cancer-related genes in the region. The analysis revealed that seven tumors contained large RNO6-derived homogeneously staining regions (HSRs) in addition to several normal or near-normal RNO6 chromosomes. Five tumors (two of which also had HSRs) exhibited a selective increase of the RNO6q11-q16 segment, sometimes in conjunction with moderate amplification of one or a few genes. Most commonly, the amplification affected the region centered around band 6q16 and included the Mycn, Ddx1, and Rrm2 genes. A second region, centering around Slc8a1 and Xdh, also was affected by gene amplification but to a lesser extent. The aberrations in the proximal part of RNO6 were further analyzed using allelotyping of microsatellite markers in all tumors from animals that were heterozygous in the proximal RNO6 region. We could detect allelic imbalance (AI) in 12 of 20 informative tumors, 6 of which were in addition to those already analyzed by molecular cytogenetic methods as described. Our findings suggest that increase/amplification of genes in this chromosome region contribute to the development of this hormone-dependent tumor.
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| 3. |
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| 4. |
- Hamta, Ahmad, 1961, et al.
(författare)
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Chromosome ideograms of the laboratory rat (Rattus norvegicus) based on high-resolution banding, and anchoring of the cytogenetic map to the DNA sequence by FISH in sample chromosomes.
- 2006
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Ingår i: Cytogenetic and genome research. - : S. Karger AG. - 1424-859X .- 1424-8581. ; 115:2, s. 158-68
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Tidskriftsartikel (refereegranskat)abstract
- A detailed banded ideogram representation of the rat chromosomes was constructed based on actual G-banded prometaphase chromosomes. The approach yielded 535 individual bands, a significant increase compared to previously presented ideograms. The new ideogram was adapted to the existing band nomenclature. The gene locus positions in the rat draft DNA sequence were compared to the chromosomal positions as determined by dual-color FISH, using rat (RNO) chromosomes 6 and 15 and a segment of RNO4 as sample regions. It was found that there was generally an excellent correlation in the chromosome regions tested between the relative gene position in the DNA molecules and the sub-chromosomal localization by FISH and subsequent information transfer on ideograms from measurements of chromosomal images. However, in the metacentric chromosome (RNO15), the correlation was much better in the short arm than in the long arm, suggesting that the centromeric region may distort the linear relationship between the chromosomal image and the corresponding DNA molecule.
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| 5. |
- Karlsson, Elin, 1979, et al.
(författare)
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Chromosomal changes associated with clinical outcome in lymph node-negative breast cancer.
- 2007
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Ingår i: Cancer genetics and cytogenetics. - : Elsevier BV. - 0165-4608 .- 1873-4456. ; 172:2, s. 139-46
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Tidskriftsartikel (refereegranskat)abstract
- Breast cancer is the most common malignancy among women and accounts for over one million new cases worldwide per year. Lymph node-negative breast cancer patients are reputed as having a better prognosis than lymph node-positive ones. Around 20% of the lymph node-negative patients die within 10 years after diagnosis. To improve the prognostics of node-negative breast cancer, it is important to understand the underlying biologic mechanisms promoting survival, such as specific genetic changes in the tumor genome. In this study, CGH was applied to analyze 64 tumors from node-negative breast cancer patients to identify DNA copy number changes in chromosomes and chromosome regions that may be correlated to survival. The main findings show gains at 4q, 5q31 approximately qter, 6q12 approximately q16, and 12q14 approximately q22, as well as losses of 17p, 18p, and Xq, which were significantly more recurrent in tumors from deceased patients than in tumors from survivors. The average number of chromosomal changes was higher in the tumors from deceased compared to the survivor tumors. Our findings suggest that tumors with specific chromosomal aberrations at 4q, 5q31 approximately qter, 6q12 approximately q16, 12q14 approximately q22, 17p, 18p, and Xq result in an aggressive form of breast cancer and that these patients are predisposed to succumb to breast cancer.
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| 6. |
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| 7. |
- Möllerström, Elin, et al.
(författare)
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High-resolution genomic profiling to predict 10-year overall survival in node-negative breast cancer.
- 2010
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Ingår i: Cancer genetics and cytogenetics. - : Elsevier BV. - 1873-4456 .- 0165-4608. ; 198:2, s. 79-89
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Tidskriftsartikel (refereegranskat)abstract
- Women with clinically node-negative breast cancer have a better prognosis than do those with axillary lymph node metastasis. Nonetheless, approximately 20% of node-negative patients die within 15 years of diagnosis, and thus additional prognostic markers are greatly needed. To identify specific copy number alterations (CNAs) that differed in frequency between 10-year survivors and deceased patients with node-negative breast cancer, array comparative genomic hybridization (aCGH) was applied to 41 primary node-negative breast tumors. Fisher's exact test was used to identify significantly different CNAs between 10-year survivors and deceased patients. Losses at 8p21.2 approximately p21.3, 8p23.1 approximately p23.2, Xp21.3, and Xp22.31 approximately p22.33 were significantly more common in tumors from deceased patients, suggesting that these alterations may contribute to tumor aggressiveness. Gains at 1q25.2 approximately q25.3 and 1q31.3 approximately q41 were more prevalent in tumors from survivors; specific gains at these genomic regions may inhibit further tumor progression, resulting in a less aggressive form of node-negative breast cancer. Evaluation of the identified CNAs in an independent external data set verified the prognostic potential of the 1q31.3 approximately q41 region. Although further extensive validation is needed, the prognostic CNAs identified in this work may in time facilitate the clinical assessment of breast cancer.
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