| 61. |
- Erdelyi, Mate, 1975-
(författare)
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Pterocarpans and isoflavones from the root bark of Millettia micans and of Millettia dura
- 2016
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Ingår i: Phytochemistry Letters. - 1874-3900 .- 1876-7486. ; 21, s. 216-220-
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Tidskriftsartikel (refereegranskat)abstract
- From the CH2Cl2/CH3OH (1:1) extract of the root bark of Millettia micans, a new pterocarpan, (6aR,11aR)-3-hydroxy-7,8,9-trimethoxypterocarpan (1), named micanspterocarpan, was isolated. Similar investigation of the CH2Cl2/CH3OH (1:1) extract of the root bark of Millettia dura gave a further new pterocarpan, (6aR,11aR)-8,9-methylenedioxy-3-prenyloxypterocarpan (2), named 3-O-prenylmaackiain, along with six known isoflavones (3-8) and a chalcone (9). All purified compounds were identified by NMR and MS, whereas the absolute configurations of the new pterocarpans were established by chriptical data analyses including quantum chemical ECD calculation. Among the isolated constituents, calopogonium isoflavone B (3) and isoerythrin A-4′-(3-methylbut-2-enyl) ether (4) showed marginal activities against the 3D7 and the Dd2 strains of Plasmodium falciparum (70–90% inhibition at 40 μM). Maximaisoflavone B (5) and 7,2′-dimethoxy-4′,5′-methylenedioxyisoflavone (7) were weakly cytotoxic (IC50 153.5 and 174.1 μM, respectively) against the MDA-MB-231 human breast cancer cell line. None of the tested compounds showed in-vitro translation inhibitory activity or toxicity against the HEK-293 human embryonic kidney cell line at 40 μM.
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| 62. |
- Fitzpatrick, Paul A., et al.
(författare)
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Robotic Mammosphere Assay for High-Throughput Screening in Triple-Negative Breast Cancer
- 2017
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Ingår i: Slas Discovery. - : Elsevier BV. - 2472-5552. ; 22:7, s. 827-836
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Tidskriftsartikel (refereegranskat)abstract
- In order to identify novel treatment principles specifically affecting cancer stem cells in triple-negative breast cancer, we have developed a high-throughput screening method based on the mammosphere and anoikis resistance assays allowing us to screen compounds using a functional readout. The assay was validated against manual protocols and through the use of positive controls, such as the response to hypoxia and treatment with the known cancer stem cell-targeting compound salinomycin. Manual and robotic procedures were compared and produced similar results in cell handling, cell cultures, and counting techniques, with no statistically significant difference produced from either method. The variance between samples processed manually versus robotically was no greater than 0.012, while Levene's test of significance was 0.2, indicating no significant difference between mammosphere data produced manually or robotically. Through the screening of 989 FDA-approved drugs and a follow-up screen assessing the antineoplastic subgroup, we have identified three therapeutic compounds with the ability to modulate the breast cancer stem cell fraction in the triple-negative breast cancer cell line MDA-MB-231, highlighting their potential usage as stem cell-specific adjuvant treatments.
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| 63. |
- Garre, Elena, 1978, et al.
(författare)
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Breast Cancer Patient-Derived Scaffolds Can Expose Unique Individual Cancer Progressing Properties of the Cancer Microenvironment Associated with Clinical Characteristics
- 2022
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Ingår i: Cancers. - : MDPI AG. - 2072-6694. ; 14:9
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Tidskriftsartikel (refereegranskat)abstract
- Simple Summary Despite huge progress in cancer diagnostics and medicine we still lack optimal cancer treatments for patients with aggressive diseases. This problem can be influenced by the biological heterogeneity of cancer cells as well as poorly understood cancer promoting effects of the cancer microenvironment being an important part of the cancer niche. In this study we have specifically monitored the activity of the cancer microenvironment in breast cancer patients using cell-free scaffolds repopulated with reporter cancer cells sensing the activity of the patient environment. The data show that scaffold induced changes in epithelial-mesenchymal transition and pluripotency markers were linked to clinical and prognostic properties of the original cancer and the information was even more precise when matching estrogen receptor status in our system. The findings highlight that patient-derived scaffolds uncover important information about varying malignant promoting properties in the cancer niche and can be used as a complementary diagnostic tool. Breast cancer is a heterogeneous disease in terms of cellular and structural composition, and besides acquired aggressive properties in the cancer cell population, the surrounding tumor microenvironment can affect disease progression and clinical behaviours. To specifically decode the clinical relevance of the cancer promoting effects of individual tumor microenvironments, we performed a comprehensive test of 110 breast cancer samples using a recently established in vivo-like 3D cell culture platform based on patient-derived scaffolds (PDSs). Cell-free PDSs were recellularized with three breast cancer cell lines and adaptation to the different patient-based microenvironments was monitored by quantitative PCR. Substantial variability in gene expression between individual PDS cultures from different patients was observed, as well as between different cell lines. Interestingly, specific gene expression changes in the PDS cultures were significantly linked to prognostic features and clinical information from the original cancer. This link was even more pronounced when ER alpha-status of cell lines and PDSs matched. The results support that PDSs cultures, including a cancer cell line of relevant origin, can monitor the activity of the tumor microenvironment and reveal unique information about the malignancy-inducing properties of the individual cancer niche and serve as a future complementary diagnostic tool for breast cancer.
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| 64. |
- Gururaj, Anupama E, et al.
(författare)
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Breast cancer-amplified sequence 3, a target of metastasis-associated protein 1, contributes to tamoxifen resistance in premenopausal patients with breast cancer
- 2006
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Ingår i: Cell Cycle. - 1551-4005. ; 5:13, s. 1407-1410
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Tidskriftsartikel (refereegranskat)abstract
- Lysine acetylation occurs in many protein targets, including core histones, transcription factors, and other proteins. Metastasis-associated protein 1 (MTA1) is implicated in the progression and metastasis of various epithelial tumors. Because MTA1 functions as a transcriptional coregulator, much of its role in cancer promoting processes are likely to involve its ability to regulate the transcription of downstream target genes that encode effector proteins. We recently showed that MTA1 could be post-translationally modified by acetylation, which modulates its function as a coregulator molecule. We also defined a chromatin target of MTA1, namely, breast cancer-amplified sequence 3 (BCAS3), in the context of which MTA1 behaves as a transcriptional coactivator in breast cancer cells. Because the phenotypic effect of BCAS3 overexpression in tumors has not been defined, we investigated the consequence of increased expression of BCAS3 in human breast tumors. Here, we report that BCAS3 overexpression in hormone receptor-positive premenopausal breast cancer seemed to be associated with impaired responses to tamoxifen. Our findings have implications for endocrine therapy.
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| 65. |
- Gururaj, AE, et al.
(författare)
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MTA1, a transcriptional activator of breast cancer amplified sequence 3
- 2006
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Ingår i: Proceedings of the National Academy of Sciences. - : Proceedings of the National Academy of Sciences. - 1091-6490 .- 0027-8424. ; 103:17, s. 6670-6675
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Tidskriftsartikel (refereegranskat)abstract
- Here we define a function of metastasis-associated protein 1 (MTA1), a presumed corepressor of estrogen receptor alpha (ER alpha), as a transcriptional activator of Breast Cancer Amplified Sequence 3 (BCAS3), a gene amplified and overexpressed in breast cancers. We identified BCAS3 as a MTA1 chromatin target in a functional genomic screen. MTA1 stimulation of BCAS3 transcription required ERa and involved a functional ERE half-site in BCAS3. Furthermore, we discovered that MTA1 is acetylated on lysine 626, and that this acetylation is necessary for a productive transcriptional recruitment of RNA polymerase 11 complex to the BCAS3 enhancer sequence. BCAS3 expression was elevated in mammary tumors from MTA1 transgenic mice and 60% of the human breast tumors, and correlated with the coexpression of MTA1 as well as with tumor grade and proliferation of primary breast tumor samples. These findings reveal a previously unrecognized function of MTA1 in stimulating BCAS3 expression and suggest an important role for MTA1-BCAS3 pathway in promoting cancerous phenotypes in breast tumor cells.
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| 66. |
- Gustafsson, Anna, et al.
(författare)
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Patient-derived scaffolds as a drug-testing platform for endocrine therapies in breast cancer
- 2021
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- Three-dimensional cell culture platforms based on decellularised patient-based microenvironments provide in vivo-like growth conditions allowing cancer cells to interact with intact structures and components of the surrounding tissue. A patient-derived scaffold (PDS) model was therefore evaluated as a testing platform for the endocrine therapies (Z)-4-Hydroxytamoxifen (4OHT) and fulvestrant as well as the CDK4/6-inhibitor palbociclib, monitoring the treatment responses in breast cancer cell lines MCF7 and T47D adapted to the patient-based microenvironments. MCF7 cells growing in PDSs showed increased resistance to 4OHT and fulvestrant treatment (100- and 20-fold) compared to 2D cultures. Quantitative PCR analyses of endocrine treated cancer cells in PDSs revealed upregulation of pluripotency markers further supported by increased self-renewal capacity in sphere formation assays. When comparing different 3D growth platforms including PDS, matrigel, gelatin sponges and 3D-printed hydrogels, 3D based cultures showed slightly varying responses to fulvestrant and palbociclib whereas PDS and matrigel cultures showed more similar gene expression profiles for 4OHT treatment compared to the other platforms. The results support that the PDS technique maximized to provide a multitude of smaller functional PDS replicates from each primary breast cancer, is an up-scalable patient-derived drug-testing platform available for gene expression profiling and downstream functional assays.
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| 67. |
- Hagerling, Catharina, et al.
(författare)
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WNT-5a-CKIalpha signaling promotes beta -catenin/E-cadherin complex formation and intercellular adhesion in human breast epithelial cells.
- 2009
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Ingår i: Journal of Biological Chemistry. - 1083-351X. ; 284, s. 10968-10979
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Tidskriftsartikel (refereegranskat)abstract
- Wnt-5a is a non-transforming Wnt protein that is implicated in cell-polarity, adhesion and motility. We have previously shown that low expression of Wnt-5a is a predictor of shorter disease-free survival in human breast cancer. Here, we investigated whether ss-catenin/E-cadherin mediated cell-cell adhesion was affected by loss of Wnt-5a in breast carcinomas, thereby promoting a metastatic behavior of the tumor. We show that Wnt-5a stimulation of human breast epithelial cells leads to an increased Ca2+-dependent cell-cell adhesion. Furthermore, Wnt-5a/Casein Kinase Ia (CKIa)-specific Ser45-phosphorylation of ss-catenin is associated with an increased complex formation of ss-catenin/E-cadherin. Mutation of Ser45 decreases the ss-catenin/E-cadherin association. Also, the inhibitory effect of Wnt-5a on breast epithelial cell invasion is reduced upon mutation of ss-catenin-Ser45. The Wnt-5a-CKIa induced Ser45-phosphorylation does not lead to degradation of ss-catenin. Finally we show that human breast cancers lacking Wnt-5a protein have a significantly lower level of membrane-associated ss-catenin. Downregulation of Wnt-5a expression and subsequent reduction of membrane-associated ss-catenin in invasive breast cancer, can therefore contribute to a decreased cell-cell adhesion and increased motility resulting in a higher probability for metastatic disease.
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| 68. |
- Harrison, Hannah, et al.
(författare)
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Contrasting hypoxic effects on breast cancer stem cell hierarchy is dependent on ERα status.
- 2013
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Ingår i: Cancer research. - 1538-7445. ; 73:4, s. 1420-33
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Tidskriftsartikel (refereegranskat)abstract
- Tumor hypoxia is often linked to decreased survival in breast cancer patients and current therapeutic strategies aim to target the hypoxic response. One way in which this is done is by blocking hypoxia induced angiogenesis. Anti-angiogenic therapies show some therapeutic potential with increased disease free survival but these initial promising results are short lived and followed by tumor progression. We hypothesized that this may be due to altered cancer stem cell (CSC) activity resulting from increased tumor hypoxia. We studied the effects of hypoxia on CSC activity, using in vitro mammosphere and holoclone assays as well as in vivo limiting dilution experiments, in 13 patient-derived samples and 4 cell lines. There was a HIF1-alpha-dependent CSC increase in ER-alpha-positive cancers following hypoxic exposure which was blocked by inhibition of estrogen and Notch signaling. A contrasting decrease in CSC was seen in ER-alpha-negative cancers. We next developed a xenograft model of cell lines and patient-derived samples to assess the hypoxic-CSC response. Varying sizes of xenografts were collected and analyzed for HIF1-alpha expression and CSC. The same ER-alpha-dependent contrasting hypoxic-CSC response was seen validating the initial observation. These data suggest that ER-alpha-positive and negative breast cancer sub-types respond differently to hypoxia and, as a consequence, anti-angiogenic therapies will not be suitable for both subgroups.
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| 69. |
- Harrison, H., et al.
(författare)
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Oestrogen increases the activity of oestrogen receptor negative breast cancer stem cells through paracrine EGFR and Notch signalling
- 2013
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Ingår i: Breast Cancer Research. - : Springer Science and Business Media LLC. - 1465-5411 .- 1465-542X. ; 15:2
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Although oestrogen is essential for the development of the normal breast, adult mammary stem cells are known to be oestrogen receptor alpha (ER) negative and rely on paracrine signals in the mammary epithelium for mediation of developmental cues. However, little is known about how systemic oestrogen regulates breast cancer stem cell (CSC) activity.Methods: Here, we tested the effects of oestrogen on CSC activity in vitro and in vivo and investigated which paracrine signalling pathways locally mediate oestrogen effects.Results: CSC-enriched populations (ESA+CD44+CD24low) sorted from ER positive patient derived and established cell lines have low or absent ER expression. However, oestrogen stimulated CSC activity demonstrated by increased mammosphere and holoclone formation in vitro and tumour formation in vivo. This effect was abrogated by the anti-oestrogen tamoxifen or ER siRNA. These data suggest that the oestrogen response is mediated through paracrine signalling from non-CSCs to CSCs. We have, therefore, investigated both epidermal growth factor (EGF) and Notch receptor signals downstream of oestrogen. We demonstrate that gefitinib (epidermal growth factor receptor (EGFR) inhibitor) and gamma secretase inhibitors (Notch inhibitor) block oestrogen-induced CSC activity in vitro and in vivo but GSIs more efficiently reduce CSC frequency.Conclusions: These data establish that EGF and Notch receptor signalling pathways operate downstream of oestrogen in the regulation of ER negative CSCs. © 2013 Harrison et al.; licensee BioMed Central Ltd.
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| 70. |
- Hedberg, Y, et al.
(författare)
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Cyclin D3 protein content in human renal cell carcinoma in relation to cyclin D1 and clinico-pathological parameters
- 2002
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Ingår i: Acta Oncologica. - : Informa UK Limited. - 1651-226X .- 0284-186X. ; 41:2, s. 175-181
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Tidskriftsartikel (refereegranskat)abstract
- Aberrations in the G1/S checkpoint are common in malignancies and are probably important for tumor development. Few G1/S studies have been performed on renal cell carcinoma (RCC) and therefore in this study the cyclin D3 protein content in 80 RCCs and that in 12 corresponding normal kidney cortex tissues are characterized using Western blotting. High cyclin D3 protein content was observed in 16% of the tumors and was significantly associated with aneuploidy, high TNM stage, high nuclear grade, high proliferation and young age. There was no association between tumor cyclin D3 and patient survival. The cyclin D3 overexpression was confirmed by immunohistochemical staining of 72 tumors, showing both nuclear and cytoplasmic localization of cyclin D3 in a fraction of the tumors. The cyclin D1 content has earlier been characterized in this tumor material and there was no relation between cyclin D1 and cyclin D3 protein expression. In summary, a fraction of the tumors overexpressed cyclin D3, supporting that various aberrations in the G1/S transition are implicated in RCCs.
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