| 1. |
- Abdissa, Negera, et al.
(author)
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Cytotoxic Quinones from the roots of Aloe dawei
- 2014
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In: Molecules. - : MDPI AG. - 1420-3049 .- 1431-5157. ; 19:3, s. 3264-3273
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Journal article (peer-reviewed)abstract
- Seven naphthoquinones and nine anthraquinones were isolated from the roots of Aloe dawei by chromatographic separation. The purified metabolites were identified by NMR and MS analyses. Out of the sixteen quinones, 6-hydroxy-3,5-dimethoxy-2-methyl-1,4-naphthoquinone is a new compound. Two of the isolates, 5,8-dihydroxy-3-methoxy-2-methylnaphthalene-1,4-dione and 1-hydroxy-8-methoxy-3-methylanthraquinone showed high cytotoxic activity (IC50 1.15 and 4.85 µM) on MCF-7 breast cancer cells, whereas the others showed moderate to low cytotoxic activity against MDA-MB-231 (ER Negative) and MCF-7 (ER Positive) cancer cells.
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| 2. |
- Ansell, Anna, 1983-
(author)
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Identification of Tumor Cell- and Stroma Derived Biomarkers of Treatment Response in Head and Neck Cancer
- 2013
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Doctoral thesis (other academic/artistic)abstract
- Head and neck squamous cell carcinoma (HNSCC) poses a major health problem in the world with approximately 600 000 new cases yearly. Treatment resistance is a major problem within this patient group and despite advances in treatment strategies the overall survival rate has unfortunately not increased.One of the major components of the tumor microenvironment is the cancer associated fibroblasts (CAFs) which can modulate the treatment sensitivity, tumor growth, and the invasive potential of tumor cells.The aim of this thesis was to identify predictive markers for treatment response in HNSCC and to study the crosstalk between tumor cells and CAFs that may underlie treatment resistance.In paper I, we identified gene expression differences between one cisplatin sensitive cell line and two cisplatin resistant cell lines, by microarray analysis, and found that a high expression of matrix metalloproteinase (MMP) -7 was associated with resistance to cisplatin. In paper II, the epidermal growth factor (EGF) receptor ligands EGF, amphiregulin, and epiregulin were evaluated regarding their potential use as predictive biomarkers for cetuximab treatment response in tongue cancer cell lines and it was shown that EGF may serve as a marker for poor cetuximab response. In paper III and IV, we investigated the influence of CAFs on the proliferation, migration, gene expression, and cetuximab response of tumor cells. It was found that CAFs induced resistance to cetuximab in a MMP-dependent manner. In addition, a microarray analysis, comparing tumor cells co-cultured with CAFs and tumor cells cultured alone, revealed that CAFs induced multiple gene expression changes in tumor cells some of which are related to epithelial to mesenchymal transition. Some of these changes were found to be dependent on cell-cell contact.Taken together, we here suggest MMP-7 and EGF to be predictive markers of cisplatin and cetuximab response, respectively. We also show that CAFs protect HNSCC cells from cetuximab treatment; however, the factor responsible for the protective effect is yet to be discovered.
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| 3. |
- Björner, Sofie, et al.
(author)
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Downregulation of miR-92a Is Associated with Aggressive Breast Cancer Features and Increased Tumour Macrophage Infiltration.
- 2012
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In: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:4
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Journal article (peer-reviewed)abstract
- BACKGROUND: MicroRNAs are small non-coding RNAs involved in the regulation of gene expression on a posttranscriptional level. These regulatory RNAs have been implicated in numerous cellular processes and are further deregulated in different cancer types, including breast cancer. MiR-92a is part of the miR-17∼92 cluster, which was first reported to be linked to tumourigenesis. However, little is known about the expression of miR-92a in breast cancer and potential associations to tumour properties. The expression of miR-92a was therefore characterized in 144 invasive breast cancer samples using in situ hybridization and related to clinico-pathological data as well as to selected key properties of the tumour stroma, including the presence of macrophages (CD68) and cancer activated fibroblasts (alpha-SMA). METHODOLOGY/PRINCIPAL FINDINGS: To measure miR-92a levels, an in situ hybridisation protocol was developed and validated using cell lines and miR-92a inhibitors. The expression in the tumour samples was objectively evaluated using digital image analysis program subtracting background activities. We found that the miR-92a expression varied between tumours and was inversely correlated to tumour grade (r = -0.276, p = 0.003) and recurrence-free survival (p = 0.008) and provided independent prognostic information in multivariate Cox analysis (HR: 0.375, CI: 0.145-0.972, p = 0.043). MiR-92a was moreover inversely correlated to the number of infiltrating macrophages in the tumour stroma (r = -0.357, p<0.001), and downregulation of miR-92a promoted cell migration (p<0.01). CONCLUSIONS/SIGNIFICANCE: This study demonstrates that downregulation of miR-92a in breast cancer is linked to key epithelial and stromal properties as well as clinical outcome.
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| 4. |
- Björner, Sofie, et al.
(author)
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Epithelial and Stromal MicroRNA Signatures of Columnar Cell Hyperplasia Linking Let-7c to Precancerous and Cancerous Breast Cancer Cell Proliferation
- 2014
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In: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 9:8
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Journal article (peer-reviewed)abstract
- Columnar cell hyperplasia (CCH) is the earliest histologically identifiable breast lesion linked to cancer progression and is characterized by increased proliferation, decreased apoptosis and elevated oestrogen receptor alpha (ER alpha) expression. The mechanisms underlying the initiation of these lesions have not been clarified but might involve early and fundamental changes in cancer progression. MiRNAs are key regulators of several biological processes, acting by influencing the post-transcriptional regulation of numerous targets, thus making miRNAs potential candidates in cancer initiation. Here we have defined novel epithelial as well as stromal miRNA signatures from columnar cell hyperplasia lesions compared to normal terminal duct lobular units by using microdissection and miRNA microarrays. Let-7c were among the identified downregulated epithelial miRNAs and its functions were delineated in unique CCH derived cells and breast cancer cell line MCF-7 suggesting anti-proliferative traits potentially due to effects on Myb and ER alpha. MiR-132 was upregulated in the stroma surrounding CCH compared to stoma surrounding normal terminal duct lobular units (TDLUs), and overexpression of miR-132 in immortalized fibroblasts and in fibroblasts co-cultured with epithelial CCH cells caused substantial expression changes of genes involved in metabolism, DNA damage and cell motility. The miRNA signatures identified in CCH indicate early changes in the epithelial and stromal compartment of CCH and could represent early key alterations in breast cancer progression that potentially could be targeted in novel prevention or treatment schedules.
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| 5. |
- Brennan, D. J., et al.
(author)
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The cocaine- and amphetamine-regulated transcript mediates ligand-independent activation of ER alpha, and is an independent prognostic factor in node-negative breast cancer
- 2012
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In: Oncogene. - : Springer Science and Business Media LLC. - 1476-5594 .- 0950-9232. ; 31:30, s. 3483-3494
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Journal article (peer-reviewed)abstract
- Personalized medicine requires the identification of unambiguous prognostic and predictive biomarkers to inform therapeutic decisions. Within this context, the management of lymph node-negative breast cancer is the subject of much debate with particular emphasis on the requirement for adjuvant chemotherapy. The identification of prognostic and predictive biomarkers in this group of patients is crucial. Here, we demonstrate by tissue microarray and automated image analysis that the cocaine- and amphetamine-regulated transcript (CART) is expressed in primary and metastatic breast cancer and is an independent poor prognostic factor in estrogen receptor (ER)-positive, lymph node-negative tumors in two separate breast cancer cohorts (n = 690; P = 0.002, 0.013). We also show that CART increases the transcriptional activity of ER alpha in a ligand-independent manner via the mitogen-activated protein kinase pathway and that CART stimulates an autocrine/paracrine loop within tumor cells to amplify the CART signal. Additionally, we demonstrate that CART expression in ER-positive breast cancer cell lines protects against tamoxifen-mediated cell death and that high CART expression predicts disease outcome in tamoxifen-treated patients in vivo in three independent breast cancer cohorts. We believe that CART profiling will help facilitate stratification of lymph node-negative breast cancer patients into high- and low-risk categories and allow for the personalization of therapy. Oncogene (2012) 31, 3483-3494; doi:10.1038/onc.2011.519; published online 5 December 2011
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| 6. |
- Bundred, Nigel J, et al.
(author)
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Cyclooxygenase-2 inhibition does not improve the reduction in ductal carcinoma in situ proliferation with aromatase inhibitor therapy: results of the ERISAC randomized placebo-controlled trial.
- 2010
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In: Clinical cancer research : an official journal of the American Association for Cancer Research. - 1078-0432. ; 16:5, s. 1605-12
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Journal article (peer-reviewed)abstract
- Tamoxifen reduces risk of recurrence after breast conservation surgery for ductal carcinoma in situ (DCIS), but no data exists on the effectiveness of aromatase inhibitors for DCIS. Cyclooxygenase-2 (COX-2) is overexpressed in DCIS, representing another potential therapeutic target. The aim of the study was to determine the effect of aromatase and/or COX-2 inhibition on epithelial proliferation and apoptosis in a presurgical study of estrogen receptor (ER)-positive DCIS. Methods: Postmenopausal women with ER-positive DCIS diagnosed by core biopsy were randomized to a 2 x 2 design of either 14 days of exemestane or placebo and celecoxib, or placebo immediately before surgery. Paired baseline and end point biopsies were analyzed for proliferation (Ki67), apoptosis, human epidermal growth factor receptor 2 (HER2), COX-2, and progesterone receptor (PR) expression by immunohistochemistry. The primary end point was a decrease in Ki67 between diagnosis and surgical excision.
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| 7. |
- Busch, S., et al.
(author)
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Low ERK Phosphorylation in Cancer-Associated Fibroblasts Is Associated with Tamoxifen Resistance in Pre-Menopausal Breast Cancer
- 2012
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In: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 7:9
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Journal article (peer-reviewed)abstract
- Purpose: The aim of this study was to evaluate ERK phosphorylation as a stromal biomarker for breast cancer prognosis and tamoxifen treatment prediction within a randomized tamoxifen trial. Patients and Methods: Tissue microarrays of two breast cancer cohorts including in total 743 invasive breast cancer samples were analyzed for ERK phosphorylation (pERK) and smooth muscle actin-alpha expression (SMA alpha) in cancer-associated fibroblasts (CAFs) and links to clinico-pathological data and treatment-predictive values were delineated. Results: By analyzing a unique randomized tamoxifen trial including breast cancer patients receiving no adjuvant treatment we show for the first time that patients low in ERK phosphorylation in CAFs did not respond to tamoxifen treatment despite having estrogen-receptor alpha (ER alpha-positive tumors compared to patients with high pERK levels in CAFs (P = 0.015, multivariate Cox regression interaction analysis). In both clinical materials we further show a significant association between pERK and SMA alpha, a characteristic marker for activated fibroblasts. SMA alpha expression however was not linked to treatment-predictive information but instead had prognostic qualities. Conclusion: The data suggests that the presence of a subpopulation of CAFs, defined by minimal activated ERK signaling, is linked to an impaired tamoxifen response. Thus, this report illustrates the importance of the stroma for monitoring treatment effects in pre-menopausal breast cancer.
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| 8. |
- Butt, Salma, et al.
(author)
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Breastfeeding in relation to risk of different breast cancer characteristics.
- 2014
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In: BMC Research Notes. - : Springer Science and Business Media LLC. - 1756-0500. ; 7:1
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Journal article (peer-reviewed)abstract
- The aim of this present study was to examine duration of breastfeeding in relation to the risk of different subgroups of breast cancer. A prospective cohort, The Malmö Diet and Cancer study, including 14092 parous women, were followed during a mean of 10.2 years and a total of 424 incident breast cancers were diagnosed.
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| 9. |
- Butt, Salma, et al.
(author)
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Genetic predisposition, parity, age at first childbirth and risk for breast cancer.
- 2012
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In: BMC Research Notes. - : Springer Science and Business Media LLC. - 1756-0500. ; 5
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Journal article (peer-reviewed)abstract
- BACKGROUND: Recent studies have identified several single-nucleotide polymorphisms (SNPs) associated with the risk of breast cancer and parity and age at first childbirth are well established and important risk factors for breast cancer. The aim of the present study was to examine the interaction between these environmental factors and genetic variants on breast cancer risk.METHODS: The Malmö Diet and Cancer Study (MDCS) included 17 035 female participants, from which 728 incident breast cancer cases were matched to 1448 controls. The associations between 14 SNPs and breast cancer risk were investigated in different strata of parity and age at first childbirth. A logistic regression analysis for the per allele risk, adjusted for potential confounders yielded odds ratios (OR) with 95% confidence intervals (CI).RESULTS: Six of the previously identified SNPs showed a statistically significant association with breast cancer risk: rs2981582 (FGFR2), rs3803662 (TNRC9), rs12443621 (TNRC9), rs889312 (MAP3K1), rs3817198 (LSP1) and rs2107425 (H19). We could not find any statistically significant interaction between the effects of tested SNPs and parity/age at first childbirth on breast cancer risk after adjusting for multiple comparisons.CONCLUSIONS: The results of this study are in agreement with previous studies of null interactions between tested SNPs and parity/age at first childbirth with regard to breast cancer risk.
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| 10. |
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