1. |
- Arildsen, Nicolai Skovbjerg, et al.
(författare)
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Involvement of chromatin remodeling genes and the Rho GTPases RhoB and CDC42 in ovarian clear cell carcinoma
- 2017
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Ingår i: Frontiers in Oncology. - : Frontiers Media SA. - 2234-943X. ; 7:MAY, s. 1-11
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Ovarian clear cell carcinomas (OCCCs) constitute a rare ovarian cancer subtype with distinct clinical features, but may nonetheless be difficult to distinguish morphologically from other subtypes. There is limited knowledge of genetic events driving OCCC tumorigenesis beyond ARID1A, which is reportedly mutated in 30-50% of OCCCs. We aimed to further characterize OCCCs by combined global transcriptional profiling and targeted deep sequencing of a panel of well-established cancer genes. Increased knowledge of OCCC-specific genetic aberrations may help in guiding development of targeted treatments and ultimately improve patient outcome. Methods: Gene expression profiling of formalin-fixed, paraffin-embedded (FFPE) tissue from a cohort of the major ovarian cancer subtypes (cohort 1; n = 67) was performed using whole-genome cDNA-mediated Annealing, Selection, extension and Ligation (WG-DASL) bead arrays, followed by pathway, gene module score, and gene ontology analyses, respectively. A second FFPE cohort of 10 primary OCCCs was analyzed by targeted DNA sequencing of a panel of 60 cancer-related genes (cohort 2). Non-synonymous and non-sense variants affecting single-nucleotide variations and insertions or deletions were further analyzed. A tissue microarray of 43 OCCCs (cohort 3) was used for validation by immunohistochemistry and chromogenic in situ hybridization. Results: Gene expression analyses revealed a distinct OCCC profile compared to other histological subtypes, with, e.g., ERBB2, TFAP2A, and genes related to cytoskeletal actin regulation being overexpressed in OCCC. ERBB2 was, however, not overexpressed on the protein level and ERBB2 amplification was rare in the validation cohort. Targeted deep sequencing revealed non-synonymous variants or insertions/deletions in 11/60 cancer-related genes. Genes involved in chromatin remodeling, including ARID1A, SPOP, and KMT2D were frequently mutated across OCCC tumors. Conclusion: OCCCs appear genetically heterogeneous, but harbor frequent alterations in chromatin remodeling genes. Overexpression of TFAP2A and ERBB2 was observed on the mRNA level in relation to other ovarian cancer subtypes. However, overexpression of ERBB2 was not reflected by HER2 amplification or protein overexpression in the OCCC validation cohort. In addition, Rho GTPase-dependent actin organization may also play a role in OCCC pathogenesis and warrants further investigation. The distinct biological features of OCCC discovered here may provide a basis for novel targeted treatment strategies.
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2. |
- Bartuma, Katarina, et al.
(författare)
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Ovarian cancer at young age: the contribution of mismatch-repair defects in a population-based series of epithelial ovarian cancer before age 40.
- 2007
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Ingår i: International Journal of Gynecological Cancer. - : BMJ. - 1048-891X .- 1525-1438. ; 17, s. 789-793
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Tidskriftsartikel (refereegranskat)abstract
- At least one of ten patients with ovarian cancer is estimated to develop their tumor because of heredity with the breast and ovarian cancer syndrome due to mutations in the BRCA1 and BRCA2 genes and hereditary nonpolyposis colorectal cancer (HNPCC) being the major genetic causes. Cancer at young age is a hallmark of heredity, and ovarian cancers associated with HNPCC have been demonstrated to develop at a particularly early age. We used the Swedish Cancer Registry to identify a population-based series of 98 invasive epithelial ovarian cancers that developed before 40 years. Mucinous and endometrioid cancers were overrepresented and were diagnosed in 27% and 16% of the tumors, respectively. Immunostaining using antibodies against MLH1, PMS2, MSH2, and MSH6 was used to assess the mismatch-repair status and revealed loss of expression of MLH1/PMS2 in two cases, loss of MSH2/MSH6 in one case, and loss of MSH6 only in three tumors. A microsatellite instability–high phenotype was verified in five of six tumors. Based on the identified mutations and family history of cancer, several of these individuals are likely to be affected by HNPCC. We conclude that although the causes of the vast majority of epithelial ovarian cancer at young age are unknown, HNPCC should be considered because of the high risk of metachronous colorectal cancer in the individual and the possibility of preventing additional cancers in the family through control programs.
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3. |
- Jönsson, Jenny-Maria, et al.
(författare)
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Distinct gene expression profiles in ovarian cancer linked to Lynch syndrome.
- 2014
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Ingår i: Familial Cancer. - : Springer Science and Business Media LLC. - 1389-9600 .- 1573-7292. ; 13:4, s. 537-545
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Tidskriftsartikel (refereegranskat)abstract
- Ovarian cancer linked to Lynch syndrome represents a rare subset that typically presents at young age as early-stage tumors with an overrepresentation of endometrioid and clear cell histologies. We investigated the molecular profiles of Lynch syndrome-associated and sporadic ovarian cancer with the aim to identify key discriminators and central tumorigenic mechanisms in hereditary ovarian cancer. Global gene expression profiling using whole-genome c-DNA-mediated Annealing, Selection, extension, and Ligation was applied to 48 histopathologically matched Lynch syndrome-associated and sporadic ovarian cancers. Lynch syndrome-associated and sporadic ovarian cancers differed by 349 significantly deregulated genes, including PTPRH, BIRC3, SHH and TNFRSF6B. The genes involved were predominantly linked to cell growth, proliferation, and cell-to-cell signaling and interaction. When stratified for histologic subtype, hierarchical clustering confirmed distinct differences related to heredity in the endometrioid and serous subtypes. Furthermore, separate clustering was achieved in an independent, publically available data set. The distinct genetic signatures in Lynch syndrome-associated and sporadic ovarian cancers point to alternative preferred tumorigenic routes and suggest that genetic discriminators may be relevant for molecular diagnostics and targeted therapeutics.
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