| 1. |
- Akhoondi, Shahab, et al.
(författare)
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FBXW7/hCDC4 is a general tumor suppressor in human cancer
- 2007
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Ingår i: Cancer Research. - 0008-5472 .- 1538-7445. ; 67:19, s. 9006-9012
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Tidskriftsartikel (refereegranskat)abstract
- The ubiquitin-proteasome system is a major regulatory pathway of protein degradation and plays an important role in cellular division. Fbxw7 (or hCdc4), a member of the F-box family of proteins, which are substrate recognition components of the multisubunit ubiquitin ligase SCF (Skpl-Cdc53/ Cullin-F-box-protein), has been shown to mediate the ubiquitin-dependent proteolysis of several oncoproteins including cyclin El, c-Myc, c-Jun, and Notch. The oncogenic potential of Fbxw7 substrates, frequent allelic loss in human cancers, and demonstration that mutation of FBXW7 cooperates with p53 in mouse tumorigenesis have suggested that Fbxw7 could function as a tumor suppressor in human cancer. Here, we carry out an extensive genetic screen of primary tumors to evaluate the role of FBXW7 as a tumor suppressor in human tumorigenesis. Our results indicate that FBXW7 is inactivated by mutation in diverse human cancer types with an overall mutation frequency of ∼ 6%. The highest mutation frequencies were found in tumors of the bile duct (cholangio-carcinomas, 35%), blood (T-cell acute lymphocytic leukemia, 31%), endometrium (9%), colon (9%), and stomach (6%). Approximately 43% of all mutations occur at two mutational "hotspots," which alter Arg residues (Arg465 and Arg479) that are critical for substrate recognition. Furthermore, we show that Fbxw7Arg465 hotspot mutant can abrogate wild-type Fbxw7 function through a dominant negative mechanism. Our study is the first comprehensive screen of FBXW7 mutations in various human malignancies and shows that FBXW7 is a general tumor suppressor in human cancer.
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| 2. |
- Heinze, Karolin, et al.
(författare)
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Validated biomarker assays confirm ARID1A loss is confounded with MMR deficiency, CD8 TIL infiltration, and provides no independent prognostic value in endometriosis-associated ovarian carcinomas.
- 2021
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Ingår i: The Journal of pathology. - : Wiley. - 1096-9896 .- 0022-3417. ; 256:4, s. 388-401
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Tidskriftsartikel (refereegranskat)abstract
- ARID1A (BAF250a) is a component of the SWI/SNF chromatin modifying complex, plays an important tumour suppressor role, and is considered prognostic in several malignancies. However, in ovarian carcinomas there are contradictory reports on its relationship to outcome, immune response, and correlation with clinicopathological features. We assembled a series of 1,623 endometriosis-associated ovarian carcinomas, including 1,078 endometrioid (ENOC) and 545 clear cell (CCOC) ovarian carcinomas through combining resources of the Ovarian Tumor Tissue Analysis (OTTA) Consortium, the Canadian Ovarian Unified Experimental Resource (COEUR), local, and collaborative networks. Validated immunohistochemical surrogate assays for ARID1A mutations were applied to all samples. We investigated associations between ARID1A loss/mutation, clinical features, outcome, CD8+ tumour-infiltrating lymphocytes (CD8+ TIL), and DNA mismatch repair deficiency (MMRd). ARID1A loss was observed in 42% of CCOC and 25% of ENOC. We found no associations between ARID1A loss and outcomes, stage, age, or CD8+ TIL status in CCOC. Similarly, we found no association with outcome or stage in endometrioid cases. In ENOC, ARID1A loss was more prevalent in younger patients (p = 0.012), and associated with MMRd (p < 0.001), and presence of CD8+ TIL (p = 0.008). Consistent with MMRd being causative of ARID1A mutations, in a subset of ENOC we also observed an association between ARID1A loss-of-function mutation as a result of small indels (p = 0.035, versus single nucleotide variants). In ENOC, the association between ARID1A loss, CD8+ TIL, and age, appears confounded by MMRd status. Although this observation does not explicitly rule out a role for ARID1A influence on CD8+ TIL infiltration in ENOC, given current knowledge regarding MMRd, it seems more likely that effects are dominated by the hypermutation phenotype. This large dataset with consistently applied biomarker assessment now provides a benchmark for the prevalence of ARID1A loss-of-function mutations in endometriosis-associated ovarian cancers and brings clarity to the prognostic significance. This article is protected by copyright. All rights reserved.
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| 3. |
- Kobel, M., et al.
(författare)
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p53 and ovarian carcinoma survival: an Ovarian Tumor Tissue Analysis consortium study
- 2023
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Ingår i: Journal of Pathology Clinical Research. - : Wiley. - 2056-4538. ; 9:3, s. 208-222
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Tidskriftsartikel (refereegranskat)abstract
- Our objective was to test whether p53 expression status is associated with survival for women diagnosed with the most common ovarian carcinoma histotypes (high-grade serous carcinoma [HGSC], endometrioid carcinoma [EC], and clear cell carcinoma [CCC]) using a large multi-institutional cohort from the Ovarian Tumor Tissue Analysis (OTTA) consortium. p53 expression was assessed on 6,678 cases represented on tissue microarrays from 25 participating OTTA study sites using a previously validated immunohistochemical (IHC) assay as a surrogate for the presence and functional effect of TP53 mutations. Three abnormal expression patterns (overexpression, complete absence, and cytoplasmic) and the normal (wild type) pattern were recorded. Survival analyses were performed by histotype. The frequency of abnormal p53 expression was 93.4% (4,630/4,957) in HGSC compared to 11.9% (116/973) in EC and 11.5% (86/748) in CCC. In HGSC, there were no differences in overall survival across the abnormal p53 expression patterns. However, in EC and CCC, abnormal p53 expression was associated with an increased risk of death for women diagnosed with EC in multivariate analysis compared to normal p53 as the reference (hazard ratio [HR] = 2.18, 95% confidence interval [CI] 1.36-3.47, p = 0.0011) and with CCC (HR = 1.57, 95% CI 1.11-2.22, p = 0.012). Abnormal p53 was also associated with shorter overall survival in The International Federation of Gynecology and Obstetrics stage I/II EC and CCC. Our study provides further evidence that functional groups of TP53 mutations assessed by abnormal surrogate p53 IHC patterns are not associated with survival in HGSC. In contrast, we validate that abnormal p53 IHC is a strong independent prognostic marker for EC and demonstrate for the first time an independent prognostic association of abnormal p53 IHC with overall survival in patients with CCC.
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| 4. |
- Oonk, Maaike H. M., et al.
(författare)
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Radiotherapy Versus Inguinofemoral Lymphadenectomy as Treatment for Vulvar Cancer Patients With Micrometastases in the Sentinel Node : Results of GROINSS-V II
- 2021
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Ingår i: Journal of Clinical Oncology. - : Lippincott, Williams & Wilkins. - 0732-183X .- 1527-7755. ; 39:32, s. 3623-3632
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE The Groningen International Study on Sentinel nodes in Vulvar cancer (GROINSS-V)-II investigated whether inguinofemoral radiotherapy is a safe alternative to inguinofemoral lymphadenectomy (IFL) in vulvar cancer patients with a metastatic sentinel node (SN). METHODS GROINSS-V-II was a prospective multicenter phase-II single-arm treatment trial, including patients with early-stage vulvar cancer (diameter < 4 cm) without signs of lymph node involvement at imaging, who had primary surgical treatment (local excision with SN biopsy). Where the SN was involved (metastasis of any size), inguinofemoral radiotherapy was given (50 Gy). The primary end point was isolated groin recurrence rate at 24 months. Stopping rules were defined for the occurrence of groin recurrences. RESULTS From December 2005 until October 2016, 1,535 eligible patients were registered. The SN showed metastasis in 322 (21.0%) patients. In June 2010, with 91 SN-positive patients included, the stopping rule was activated because the isolated groin recurrence rate in this group went above our predefined threshold. Among 10 patients with an isolated groin recurrence, nine had SN metastases > 2 mm and/or extracapsular spread. The protocol was amended so that those with SN macrometastases (> 2 mm) underwent standard of care (IFL), whereas patients with SN micrometastases (<= 2 mm) continued to receive inguinofemoral radiotherapy. Among 160 patients with SN micrometastases, 126 received inguinofemoral radiotherapy, with an ipsilateral isolated groin recurrence rate at 2 years of 1.6%. Among 162 patients with SN macrometastases, the isolated groin recurrence rate at 2 years was 22% in those who underwent radiotherapy, and 6.9% in those who underwent IFL (P = .011). Treatment-related morbidity after radiotherapy was less frequent compared with IFL. CONCLUSION Inguinofemoral radiotherapy is a safe alternative for IFL in patients with SN micrometastases, with minimal morbidity. For patients with SN macrometastasis, radiotherapy with a total dose of 50 Gy resulted in more isolated groin recurrences compared with IFL.
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