| 1. |
- Hallén, Magnus, et al.
(författare)
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Cytogenetic abnormalities in a hemangiopericytoma of the spleen.
- 2002
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Ingår i: Cancer Genetics and Cytogenetics. - 0165-4608. ; 136:1, s. 62-65
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Tidskriftsartikel (refereegranskat)abstract
- To date, only 16 cytogenetically abnormal hemangiopericytomas (HP) have been reported. Despite this low number, some characteristic karyotypic features have already emerged: most HP are near-diploid and breakpoints in 12q13, 12q24, and 19q13 seem to be common, with t(12;19)(q13;q13) being a recurrent translocation. Here, we report the first case of a probably benign splenic HP with chromosomal abnormalities. The abnormal karyotype was 47,XX,t(5;22;11)(q31;q11;q13),+10. None of these abnormalities have previously been reported in HP, suggesting that the karyotypic pattern of splenic HP may differ from soft tissue HP.
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| 2. |
- Jin, Charlotte, et al.
(författare)
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Karyotypic heterogeneity and clonal evolution in squamous cell carcinomas of the head and neck.
- 2002
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Ingår i: Cancer Genetics and Cytogenetics. - 0165-4608. ; 132:2, s. 85-96
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Tidskriftsartikel (refereegranskat)abstract
- Head and neck squamous cell carcinomas (HNSCC) are often characterized by complex karyotypic changes, and a substantial proportion of the reported tumors have shown intratumor heterogeneity in the form of cytogenetically related (40%) or unrelated clones (20%). In order to study intratumor heterogeneity and to distinguish the temporal order of chromosome rearrangements in these tumors, two or more samples from different areas of the same tumor were separately examined in 19 HNSCC, yielding karyotypes from a total of 42 tumor samples. Intrasample heterogeneity was observed in 16 samples. Two samples displayed both related and unrelated multiple clones, four samples showed only multiple unrelated clones, and the remaining 10 samples had only related subclones. Intersample heterogeneity was detected in all but one tumor. Five tumors showed both cytogenetically related and unrelated multiple clones, 11 were found to have only related subclones, and the remaining two tumors showed only unrelated clones. Clonal evolution could be assessed in 13 tumors. A comparison of chromosome imbalances in different subclones from these tumors suggests that partial or entire loss of 3p, 8p, 9p, and 18q and gain of genetic material from 3q and 8q are likely to be early genetic events. In contrast, loss of 1q, 6p, 7q, and chromosome 10, as well as gain of chromosome arms 5p and 7p, are most probably later genetic events. One of the examined tumors contained two highly complex clones that were cytogenetically unrelated, indicating that this tumor had a multicellular origin.
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| 3. |
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| 4. |
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| 5. |
- Ek, Sara, et al.
(författare)
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Mantle cell lymphomas express a distinct genetic signature affecting lymphocyte trafficking and growth regulation as compared with subpopulations of normal human B cells.
- 2002
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Ingår i: Cancer Research. - 1538-7445. ; 62:15, s. 4398-4405
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Tidskriftsartikel (refereegranskat)abstract
- Differential gene expression analysis, using high-density microarray chips, demonstrated 300-400 genes to be deregulated in mantle cell lymphomas (MCLs) compared with normal B-cell populations. To investigate the significance of this genetic signature in lymphoma etiology and diagnostics, we selected 90 annotated genes involved in a number of cellular functions for further analysis. Our findings demonstrated a normal gene expression of CCR7, which indicated a normal homing to primary follicles, which was in contrast to other receptors for B-cell trafficking, such as a significant down-regulation for CXCR5 and CCR6, as well as down-regulation of IL4R involved in differentiation. This indicated that the malignant transformation of a normal B cell could have appeared during the transition of a primary follicle to a germinal center, i.e., after an initial B-cell activation. Genes involved in blockage of antiproliferative signals in normal cells were also deregulated, e.g., gene expression of TGFbeta2 and Smad3 was suppressed in MCLs. Furthermore, lymphoproliferative signal pathways were active in MCLs compared with normal B cells, because genes encoding, e.g., IL10Ralpha and IL18 were up-regulated, as were oncogenes like Bcl-2 and MERTK. Genes encoding receptors for different neurotransmitters mediating B-cell stimulation, such as norepinephrine and cannabinoids were also up-regulated, again illustrating deregulation of a complex network of genes involved in growth and differentiation. Furthermore, hierarchical cluster analysis revealed two subpopulations of MCLs, which indicates that despite the homogeneous and strong overexpression of cyclin D1, further subtyping might be possible.
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| 6. |
- Fernebro, Eva, et al.
(författare)
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Evaluation of the tissue microarray technique for immunohistochemical analysis in rectal cancer.
- 2002
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Ingår i: Archives of pathology & laboratory medicine. - 0003-9985. ; 126:6, s. 702-705
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Immunohistochemical staining for tumor-associated proteins is widely used for the identification of novel prognostic markers. Recently, a tissue-conserving, high-throughput technique, tissue microarray, has been introduced. This technique uses 0.6-mm tissue core biopsy specimens, 500 to 1000 of which are brought into a new paraffin array block, which can be sectioned up to 100 times. METHODS: We evaluated the tissue microarray technique for immunohistochemical analysis in 20 rectal cancers. Immunohistochemical staining was performed for the proliferation marker Ki-67 and the tumor suppressor protein p53 in whole tissue sections and in tissue core biopsy specimens. RESULTS: The whole tissue sections were assessed by counting all cells in 10 high-power fields (x40), which resulted in a mean fraction of Ki-67-expressing tumor cells of 0.81 (range, 0.54-1.0). p53 expression assessed in whole tissue sections showed nuclear staining in 15 (75%) of 20 rectal carcinomas. For the tissue microarray technique, a median of 3 (range, 3-5) 0.6-mm tissue core biopsy specimens were studied from each of the 20 tumor specimens. The tissue microarray method gave a mean Ki-67 expression of 0.85 (range, 0.50-1.0) in tumor cell nuclei and showed p53 protein expression in the same 15 of 20 tumors as in the whole tissue sections. CONCLUSION: We conclude that the tissue microarray technique for immunohistochemical staining in rectal cancer yields staining of good quality and expression data for Ki-67 and p53 comparable to those obtained with whole tissue staining. The feasibility of tissue microarray thus enables time- and tissue-preserving studies of multiple markers in large tumor series.
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| 7. |
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| 8. |
- Jin, Charlotte, et al.
(författare)
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Characterization of chromosome aberrations in salivary gland tumors by FISH, including multicolor COBRA-FISH
- 2001
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Ingår i: Genes, Chromosomes and Cancer. - 1045-2257. ; 30:2, s. 161-167
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Tidskriftsartikel (refereegranskat)abstract
- Fluorescence in situ hybridization (FISH), including COBRA-FISH, was used to characterize 11 salivary gland tumors that had been investigated by banding analysis. Five cases were pleomorphic adenoma (PA), three were adenoid cystic carcinoma, and one case each was mucoepidermoid carcinoma, carcinoma ex-pleomorphic adenoma (CaPA), and adenocarcinoma. All 11 cases were selected on the basis that they had shown rearrangement of 6q or 9p or had unresolved aberrations after karyotyping. The COBRA-FISH and FISH analyses led to a revised karyotype in all informative cases and made it possible to clarify almost all chromosomal rearrangements occurring in the tumors. Of particular note were the confirmation of the existence of 6q deletions, a common change in salivary gland carcinomas, and the demonstration that a seemingly balanced t(6;9) resulted in del(6q). Other rearrangements that were revealed by FISH included amplification of 12q sequences (MDM2 and CDK4) in one PA. We also investigated the status of the PLAG1 gene in four cases (one PA, one CaPA, one adenoid cystic carcinoma, and one mucoepidermoid carcinoma) with 8q12 rearrangements. Only in the former two cases were the FISH results compatible with intragenic rearrangements. Overall, the results of the study show that, even with good banding quality and in karyotypes of modest complexity, much new information will be gained by supplementing the banding analysis with a multicolor FISH approach, such as COBRA-FISH.
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| 9. |
- Åkervall, Jan, et al.
(författare)
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Chromosomal translocations involving 11q13 contribute to cyclin D1 overexpression in squamous cell carcinoma of the head and neck
- 2002
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Ingår i: International Journal of Oncology. - : Spandidos Publications. - 1019-6439 .- 1791-2423. ; 20:1, s. 45-52
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Tidskriftsartikel (refereegranskat)abstract
- CCND1 amplification results in cyclin D1 overexpression. However, other unidentified genetic mechanisms contribute to enhanced gene expression. In the present study, 32 squamous cell carcinoma of the head and neck (SCCHN) were investigated regarding chromosomal abnormalities involving 11q13 by cytogenetic analysis, genomic CCND1 amplification by differential PCR and FISH, and cyclin D1 expression on the mRNA and protein level by differential RT-PCR and immunohistochemistry, respectively. CCND1 amplification, observed in 11 of 32 (34%) tumours, resulted in overexpression of cyclin D1 on the mRNA and/or protein level, in 3 cases in association with chromosomal translocations. In cytogenetic analysis, 4 tumours had hsr(11)(q13), all of which showed CCND1 amplification and cyclin D1 overexpression. Overexpression of cyclin D1 was detected at the mRNA level in 23 tumours (72%) and on the protein level in 25 tumours (78%). In one case a translocation was seen together with cyclin D1 overexpression on the mRNA level, without any cytogenetic or molecular signs of amplification. Furthermore, cases with cyclin D1 overexpression were frequently observed in the absence of any genomic rearrangement. We conclude that, besides amplifications, chromosomal translocations and other transcriptional or translational regulatory mechanisms are involved in CCND1 deregulation.
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| 10. |
- Åkervall, Jan, et al.
(författare)
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Cyclin D1 overexpression versus response to induction chemotherapy in squamous cell carcinoma of the head and neck--preliminary report
- 2001
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Ingår i: Acta Oncologica. - : Informa UK Limited. - 1651-226X .- 0284-186X. ; 40:4, s. 505-511
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to investigate whether there is an association between overexpression of cyclin D1 and response to therapy. Immunohistochemical overexpression of cyclin D1 was determined in paraffin-embedded specimens from diagnostic biopsies of 89 primary cases of squamous cell carcinoma of the head and neck (SCCHN), using a polyclonal antiserum. The tumor response rates were estimated after curative treatment (i.e. surgery and/or radiotherapy and/or chemotherapy). Patients whose tumors were overexpressing cyclin D1 showed complete or partial response to neoadjuvant chemotherapy with cisplatin/5-FU. In addition, a majority of cyclin D1 negative tumors did not respond at all to this treatment (p = 0.02, Fisher's exact test). This study indicates that immunohistochemical assessment of cyclin D1 expression in SCCHN could be a new predictive marker to select a subgroup of patients that will benefit from neoadjuvant chemotherapy.
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