| 1. |
- Kjersem, Janne B, et al.
(författare)
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Let-7 miRNA-binding site polymorphism in the KRAS 3`UTR; colorectal cancer screening population prevalence and influence on clinical outcome in patients with metastatic colorectal cancer treated with 5-fluorouracil and oxaliplatin +/- cetuximab.
- 2012
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Ingår i: BMC Cancer. - : Springer Science and Business Media LLC. - 1471-2407 .- 1471-2407. ; 12:1, s. 534-
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Recent studies have reported associations between a variant allele in a let-7 microRNA complementary site (LCS6) within the 3 untranslated region (3 UTR) of KRAS (rs61764370) and clinical outcome in metastatic colorectal cancer (mCRC) patients receiving cetuximab. The variant allele has also been associated with increased cancer risk. We aimed to reveal the incidence of the variant allele in a colorectal cancer screening population and to investigate the clinical relevance of the variant allele in mCRC patients treated with 1st line 5-fluorouracil-oxaliplatin (Nordic FLOX) +/- cetuximab.METHODS: The feasibility of the variant allele as a risk factor for CRC was investigated by comparing the LCS6 gene frequencies in 197 CRC patients, 1060 individuals with colorectal polyps, and 358 healthy controls. The relationship between clinical outcome and LCS6 genotype was analyzed in 180 mCRC patients receiving Nordic FLOX and 355 patients receiving Nordic FLOX + cetuximab in the NORDIC-VII trial (NCT00145314). RESULTS: LCS6 frequencies did not vary between CRC patients (23%), individuals with polyps (20%), and healthy controls (20%) (P=0.50). No statistically significant differences were demonstrated in the NORDIC-VII cohort even if numerically increased progression-free survival (PFS) and overall survival (OS) were found in patients with the LCS6 variant allele (8.5 (95% CI: 7.3-9.7 months) versus 7.8 months (95% CI: 7.4-8.3 months), P=0.16 and 23.5 (95% CI: 21.6-25.4 months) versus 19.5 months (95% CI: 17.8-21.2 months), P=0.31, respectively). Addition of cetuximab seemed to improve response rate more in variant carriers than in wild-type carriers (from 35% to 57% versus 44% to 47%), however the difference was not statistically significant (interaction P = 0.16).CONCLUSIONS: The LCS6 variant allele does not seem to be a risk factor for development of colorectal polyps or CRC. No statistically significant effect of the LCS6 variant allele on response rate, PFS or OS was found in mCRC patients treated with 1st line 5-fluorouracil-oxaliplatin +/- cetuximab.
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| 2. |
- Põlajeva, Jelena, 1983-, et al.
(författare)
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miRNA-21 is developmentally regulated in mouse brain and is co-expressed with SOX2 in glioma
- 2012
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Ingår i: BMC Cancer. - : Springer Science and Business Media LLC. - 1471-2407 .- 1471-2407. ; 12, s. 378-
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundMicroRNAs (miRNAs) and their role during tumor development have been studied in greatdetail during the last decade, albeit their expression pattern and regulation during normaldevelopment are however not so well established. Previous studies have shown that miRNAsare differentially expressed in solid human tumors. Platelet-derived growth factor (PDGF)signaling is known to be involved in normal development of the brain as well as in malignantprimary brain tumors, gliomas, but the complete mechanism is still lacking. We decided toinvestigate the expression of the oncogenic miR-21 during normal mouse development andglioma, focusing on PDGF signaling as a potential regulator of miR-21.MethodsWe generated mouse glioma using the RCAS/tv-a system for driving PDGF-BB expression ina cell-specific manner. Expression of miR-21 in mouse cell cultures and mouse brain wereassessed using Northern blot analysis and in situ hybridization. Immunohistochemistry andWestern blot analysis were used to investigate SOX2 expression. LNA-modified siRNA wasused for irreversible depletion of miR-21. For inhibition of PDGF signaling Gleevec(imatinib mesylate), Rapamycin and U0126, as well as siRNA were used. Statisticalsignificance was calculated using double-sided unpaired Student´s t-test.ResultsWe identified miR-21 to be highly expressed during embryonic and newborn braindevelopment followed by a gradual decrease until undetectable at postnatal day 7 (P7), thiscorrelated with SOX2 expression. Furthermore, miR-21 and SOX2 showed up-regulation andoverlapping expression pattern in RCAS/tv-a generated mouse brain tumor specimens. Uponirreversible depletion of miR-21 the expression of SOX2 was strongly diminished in bothmouse primary glioma cultures and human glioma cell lines. Interestingly, in normalfibroblasts the expression of miR-21 was induced by PDGF-BB, and inhibition of PDGFsignaling in mouse glioma primary cultures resulted in suppression of miR-21 suggesting thatmiR-21 is indeed regulated by PDGF signaling.ConclusionsOur data show that miR-21 and SOX2 are tightly regulated already during embryogenesisand define a distinct population with putative tumor cell of origin characteristics. We believethat miR-21 is a mediator of PDGF-driven brain tumors, which suggests miR-21 as apromising target for treatment of glioma.
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| 3. |
- Lehn, Sophie, et al.
(författare)
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Decreased expression of Yes-associated protein is associated with outcome in the luminal A breast cancer subgroup and with an impaired tamoxifen response
- 2014
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Ingår i: Bmc Cancer. - : Springer Science and Business Media LLC. - 1471-2407. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- Background: Yes-associated protein (YAP1) is frequently reported to function as an oncogene in many types of cancer, but in breast cancer results remain controversial. We set out to clarify the role of YAP1 in breast cancer by examining gene and protein expression in subgroups of patient material and by downregulating YAP1 in vitro and studying its role in response to the widely used anti-estrogen tamoxifen. Methods: YAP1 protein intensity was scored as absent, weak, intermediate or strong in two primary breast cancer cohorts (n = 144 and n = 564) and mRNA expression of YAP1 was evaluated in a gene expression dataset (n = 1107). Recurrence-free survival was analysed using the log-rank test and Cox multivariate analysis was used to test for independence. WST-1 assay was employed to measure cell viability and a luciferase ERE (estrogen responsive element) construct was used to study the effect of tamoxifen, following downregulation of YAP1 using siRNAs. Results: In the ER+ (Estrogen Receptor a positive) subgroup of the randomised cohort, YAP1 expression was inversely correlated to histological grade and proliferation (p = 0.001 and p = 0.016, respectively) whereas in the ER-(Estrogen Receptor a negative) subgroup YAP1 expression correlated positively to proliferation (p = 0.005). Notably, low YAP1 mRNA was independently associated with decreased recurrence-free survival in the gene expression dataset, specifically for the luminal A subgroup (p < 0.001) which includes low proliferating tumours of lower grade, usually associated with a good prognosis. This subgroup specificity led us to hypothesize that YAP1 may be important for response to endocrine therapies, such as tamoxifen, extensively used for luminal A breast cancers. In a tamoxifen randomised patient material, absent YAP1 protein expression was associated with impaired tamoxifen response which was significant upon interaction analysis (p = 0.042). YAP1 downregulation resulted in increased progesterone receptor (PgR) expression and a delayed and weaker tamoxifen in support of the clinical data. Conclusions: Decreased YAP1 expression is an independent prognostic factor for recurrence in the less aggressive luminal A breast cancer subgroup, likely due to the decreased tamoxifen sensitivity conferred by YAP1 downregulation.
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| 4. |
- Lindemann, Kristina, et al.
(författare)
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Examestane in advanced or recurrent endometrial carcinoma: a prospective phase II study by the Nordic Society of Gynecologic Oncology (NSGO)
- 2014
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Ingår i: BMC Cancer. - : Springer Science and Business Media LLC. - 1471-2407. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- Background: We evaluated the efficacy and safety of the aromatase inhibitor exemestane in patients with advanced, persistent or recurrent endometrial carcinoma. Methods: We performed an open-label one-arm, two-stage, phase II study of 25 mg of oral exemestane in 51 patients with advanced (FIGO stage III-IV) or relapsed endometrioid endometrial cancer. Patients were stratified into subsets of estrogen receptor (ER) positive and ER negative patients. Results: Recruitment to the ER negative group was stopped prematurely after 12 patients due to slow accrual. In the ER positive patients, we observed an overall response rate of 10%, and a lack of progression after 6 months in 35% of the patients. No responses were registered in the ER negative patients, and all had progressive disease within 6 months. For the total group of patients, the median progression free survival (PFS) was 3.1 months (95% CI: 2.0-4.1). In the ER positive patients the median PFS was 3.8 months (95% CI: 0.7-6.9) and in the ER negative patients it was 2.6 months (95% CI: 2.1-3-1). In the ER positive patients the median overall survival (OS) time was 13.3 months (95% CI: 7.7-18.9), in the ER negative patients the corresponding numbers were 6.1 months (95% CI: 4.1-8.2). Treatment with exemestane was well tolerated. Conclusion: Treatment of estrogen positive advanced or recurrent endometrial cancer with exemestane, an aromatase inhibitor, resulted in a response rate of 10% and lack of progression after 6 months in 35% of the patients.
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| 5. |
- Sandén, Carl, et al.
(författare)
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Forced expression of the DEK-NUP214 fusion protein promotes proliferation dependent on upregulation of mTOR
- 2013
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Ingår i: BMC Cancer. - : Springer Science and Business Media LLC. - 1471-2407. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- Background: The t(6;9)(p23;q34) chromosomal translocation is found in 1% of acute myeloid leukemia and encodes the fusion protein DEK-NUP214 (formerly DEK-CAN) with largely uncharacterized functions. Methods: We expressed DEK-NUP214 in the myeloid cell lines U937 and PL-21 and studied the effects on cellular functions. Results: In this study, we demonstrate that expression of DEK-NUP214 increases cellular proliferation. Western blot analysis revealed elevated levels of one of the key proteins regulating proliferation, the mechanistic target of rapamycin, mTOR. This conferred increased mTORC1 but not mTORC2 activity, as determined by the phosphorylation of their substrates, p70 S6 kinase and Akt. The functional importance of the mTOR upregulation was determined by assaying the downstream cellular processes; protein synthesis and glucose metabolism. A global translation assay revealed a substantial increase in the translation rate and a metabolic assay detected a shift from glycolysis to oxidative phosphorylation, as determined by a reduction in lactate production without a concomitant decrease in glucose consumption. Both these effects are in concordance with increased mTORC1 activity. Treatment with the mTORC1 inhibitor everolimus (RAD001) selectively reversed the DEK-NUP214-induced proliferation, demonstrating that the effect is mTOR-dependent. Conclusions: Our study shows that the DEK-NUP214 fusion gene increases proliferation by upregulation of mTOR, suggesting that patients with leukemias carrying DEK-NUP214 may benefit from treatment with mTOR inhibitors.
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| 6. |
- Tobin, Nicholas P., et al.
(författare)
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Cyclin D1, Id1 and EMT in breast cancer
- 2011
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Ingår i: BMC Cancer. - : Springer Science and Business Media LLC. - 1471-2407. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Background: Cyclin D1 is a well-characterised cell cycle regulator with established oncogenic capabilities. Despite these properties, studies report contrasting links to tumour aggressiveness. It has previously been shown that silencing cyclin D1 increases the migratory capacity of MDA-MB-231 breast cancer cells with concomitant increase in 'inhibitor of differentiation 1' (ID1) gene expression. Id1 is known to be associated with more invasive features of cancer and with the epithelial-mesenchymal transition (EMT). Here, we sought to determine if the increase in cell motility following cyclin D1 silencing was mediated by Id1 and enhanced EMT-features. To further substantiate these findings we aimed to delineate the link between CCND1, ID1 and EMT, as well as clinical properties in primary breast cancer. Methods: Protein and gene expression of ID1, CCND1 and EMT markers were determined in MDA-MB-231 and ZR75 cells by western blot and qPCR. Cell migration and promoter occupancy were monitored by transwell and ChIP assays, respectively. Gene expression was analysed from publicly available datasets. Results: The increase in cell migration following cyclin D1 silencing in MDA-MB-231 cells was abolished by Id1 siRNA treatment and we observed cyclin D1 occupancy of the Id1 promoter region. Moreover, ID1 and SNAI2 gene expression was increased following cyclin D1 knock-down, an effect reversed with Id1 siRNA treatment. Similar migratory and SNAI2 increases were noted for the ER-positive ZR75-1 cell line, but in an Id1-independent manner. In a meta-analysis of 1107 breast cancer samples, CCND1(low)/ID1(high) tumours displayed increased expression of EMT markers and were associated with reduced recurrence free survival. Finally, a greater percentage of CCND1(low)/ID1(high) tumours were found in the EMT-like 'claudin-low' subtype of breast cancer than in other subtypes. Conclusions: These results indicate that increased migration of MDA-MB-231 cells following cyclin D1 silencing can be mediated by Id1 and is linked to an increase in EMT markers. Moreover, we have confirmed a relationship between cyclin D1, Id1 and EMT in primary breast cancer, supporting our in vitro findings that low cyclin D1 expression can be linked to aggressive features in subgroups of breast cancer.
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| 7. |
- Elmula, Imad, et al.
(författare)
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Chromosomal aberrations in benign and malignant Bilharzia-associated bladder lesions analyzed by comparative genomic hybridization.
- 2002
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Ingår i: BMC Cancer. - : Springer Science and Business Media LLC. - 1471-2407. ; 2:5
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Bilharzia-associated bladder cancer (BAC) is a major health problem in countries where urinary schistosomiasis is endemic. Characterization of the genetic alterations in this cancer might enhance our understanding of the pathogenic mechanisms of the disease but, in contrast to nonbilharzia bladder cancer, BAC has rarely been the object of such scrutiny. In the present study, we aimed to characterize chromosomal imbalances in benign and malignant post-bilharzial lesions, and to determine whether their unique etiology yields a distinct cytogenetic profile as compared to chemically induced bladder tumors. METHODS: DNAs from 20 archival paraffin-embedded post-bilharzial bladder lesions (6 benign and 14 malignant) obtained from Sudanese patients (12 males and 8 females) with a history of urinary bilharziasis were investigated for chromosomal imbalances using comparative genomic hybridization (CGH). Subsequent FISH analysis with pericentromeric probes was performed on paraffin sections of the same cases to confirm the CGH results. RESULTS: Seven of the 20 lesions (6 carcinomas and one granuloma) showed chromosomal imbalances varying from 1 to 6 changes. The most common chromosomal imbalances detected were losses of 1p21-31, 8p21-pter, and 9p and gain of 19p material, seen in three cases each, including the benign lesion. CONCLUSION: Most of the detected imbalances have been repeatedly reported in non-bilharzial bladder carcinomas, suggesting that the cytogenetic profiles of chemical- and bilharzia-induced carcinomas are largely similar. However, loss of 9p seems to be more ubiquitous in BAC than in bladder cancer in industrialized countries.
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| 8. |
- Amini, Rose-Marie, et al.
(författare)
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Mast cells and eosinophils in invasive breast carcinoma
- 2007
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Ingår i: BMC Cancer. - : Springer Science and Business Media LLC. - 1471-2407 .- 1471-2407. ; 7, s. 165-
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Inflammatory cells in the tumour stroma has gained increasing interest recently. Thus, we aimed to study the frequency and prognostic impact of stromal mast cells and tumour infiltrating eosinophils in invasive breast carcinomas. METHODS: Tissue microarrays containing 234 cases of invasive breast cancer were prepared and analysed for the presence of stromal mast cells and eosinophils. Tumour infiltrating eosinophils were counted on hematoxylin-eosin slides. Immunostaining for tryptase was done and the total number of mast cells were counted and correlated to the proliferation marker Ki 67, positivity for estrogen and progesterone receptors, clinical parameters and clinical outcome. RESULTS: Stromal mast cells were found to correlate to low grade tumours and estrogen receptor positivity. There was a total lack of eosinophils in breast cancer tumours. CONCLUSION: A high number of mast cells in the tumours correlated to low-grade tumours and estrogen receptor positivity. Eosinophils are not tumour infiltrating in breast cancers.
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