| 1. |
- Björner, Sofie, et al.
(författare)
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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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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:4
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Tidskriftsartikel (refereegranskat)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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| 2. |
- Björner, Sofie, et al.
(författare)
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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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Ingår i: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 9:8
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Tidskriftsartikel (refereegranskat)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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| 3. |
- Larsson, Anna-Maria, et al.
(författare)
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Erythropoietin Receptor Expression and Correlation to Tamoxifen Response and Prognosis in Breast Cancer.
- 2009
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Ingår i: Clinical Cancer Research. - 1078-0432. ; 15:17, s. 5552-5559
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: The main function of erythropoietin (EPO) is to stimulate erythropoiesis. EPO receptors (EPOR) are expressed in other cell types, including tumor cells, suggesting that the EPO/EPOR pathway governs additional cellular processes besides erythropoiesis. Recombinant EPO (rhEPO) is frequently given to anemic cancer patients, although data on clinical outcome are conflicting. In an attempt to understand these clinical data, we analyzed EPO and EPOR expression in breast cancer and evaluated EPOR as a putative prognostic and predictive marker in breast cancer patients treated with tamoxifen. EXPERIMENTAL DESIGN: EPO mRNA/protein and EPOR mRNA were quantified by PCR and ELISA, respectively. Tissue microarrays containing 500 breast tumors from premenopausal women randomized to tamoxifen or no adjuvant treatment were evaluated for EPOR expression by immunohistochemistry. Predictive and prognostic information was evaluated using Kaplan-Meier curves and log-rank tests to estimate recurrence-free survival (RFS). RESULTS: EPO and EPOR were expressed in cultured cells, and breast tumor specimens expressed EPOR at varying levels. Tamoxifen treatment significantly increased RFS in patients with estrogen receptor-positive/progesterone receptor-positive (ER(+)/PR(+)) tumors with low EPOR expression (P = 0.001) but had no effect on RFS in patients with tumors with high EPOR expression (P = 0.98). In the untreated cohort, RFS was significantly improved for patients with ER(+) tumors with high EPOR expression. CONCLUSION: EPOR is abundantly expressed in breast cancer specimens. The fact that high expression of EPOR is related to an impaired tamoxifen response in ER(+)/PR(+) tumors and to improved survival in untreated patients suggests that EPOR expression in breast cancer affects tumor behavior. (Clin Cancer Res 2009;15(17):5552-9).
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| 4. |
- Saamarthy, Karunakar, et al.
(författare)
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Early diagnostic value of Bcl-3 localization in colorectal cancer
- 2015
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Ingår i: Bmc Cancer. - : Springer Science and Business Media LLC. - 1471-2407. ; 15:341
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Tidskriftsartikel (refereegranskat)abstract
- Background: B-cell leukemia 3 (Bcl-3) is a member of the inhibitor of kappa B family, which regulates a wide range of biological processes by functioning as a transcriptional activator or as a repressor of target genes. Elevated expression, sustained nuclear accumulation, and uncontrolled activation of Bcl-3 causes increased cellular proliferation or survival, dependent on the tissue and type of stimuli. Methods: We retrospectively reviewed patients who were diagnosed with colorectal cancer at Skane University Hospital in Malmo between 1st of January 1990 and 31st of December 1991. Bcl-3 localization in colorectal cancer was assessed by immunohistochemistry on tissue microarray and freshly isolated colon from patients. Correlation between Bcl-3 localization and clinicopathological parameters of the cohort were evaluated using the Spearman rank-order correlation coefficient. In addition, Bcl-3 expression and localization in colon adenocarcinoma cells were analysed by western blot, immunohistochemistry and subcellular fractionation separately. Results: We found that Bcl-3 was mainly localized in the cytoplasm in the tumour tissue isolated from colon cancer patients. Normal colon samples from the same patients showed Bcl-3 localization in the nucleus. In three out of six colon cancer cell lines, we detected elevated levels of Bcl-3. In these cell lines Bcl-3 was accumulated in the cytosol. We confirmed these findings by analysing Bcl-3 localization in a colon tissue micro array consisting of 270 cases. In these samples Bcl-3 localization correlated with the proliferation marker Ki-67, but not with the apoptotic marker Caspase 3. Conclusion: These findings indicate that analysis of the subcellular localization of Bcl-3 could be a potential-early diagnostic marker in colon cancer.
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| 5. |
- Stendahl, Maria, et al.
(författare)
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p27Kip1 is a predictive factor for tamoxifen treatment response but not a prognostic marker in premenopausal breast cancer patients.
- 2010
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Ingår i: International journal of cancer. Journal international du cancer. - : Wiley. - 1097-0215. ; 127:12, s. 2851-8
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Tidskriftsartikel (refereegranskat)abstract
- The cell-cycle regulating protein p27(Kip1) (p27) has dual roles by acting as both a cdk inhibitor and as an assembly factor for different cdk complexes. Loss of p27 has been linked to malignant features in tumours; however, the exact role of p27 deregulation in breast cancer regarding prognostic and treatment predictive information has not been fully clarified. We have evaluated p27 expression in 328 primary, Stage II breast cancers from premenopausal patients who had been randomised to either tamoxifen treatment or no adjuvant treatment after surgery. p27 was associated with the oestrogen receptor and cyclin D1, and p27 downregulation was associated with high proliferation. There was no association between recurrence-free survival (RFS) and p27 (HR = 0.800, 95% CI 0.523-1.222, p = 0.300), indicating that p27 is not a prognostic marker. The predictive value of p27 was analysed by comparing RFS in tamoxifen-treated and untreated patients in subgroups of low and high p27 expression (HR = 0.747, 95% CI 0.335-1.664, p = 0.474 and HR = 0.401, 95% CI 0.240-0.670, p < 0.001, respectively). Only patients with p27-high tumours benefited from tamoxifen (multivariate interaction analysis p = 0.034). Our study suggests that p27 downregulation is associated with tamoxifen resistance in premenopausal breast cancer but is not linked to impaired prognosis.
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