| 1. |
- Barnes, N. L. P., et al.
(författare)
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Cyclooxygenase-2 inhibition : effects on tumour growth, cell cycling and lymphangiogenesis in a xenograft model of breast cancer
- 2007
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Ingår i: British Journal of Cancer. - : Springer Science and Business Media LLC. - 0007-0920 .- 1532-1827. ; 96:4, s. 575-582
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Tidskriftsartikel (refereegranskat)abstract
- Cyclooxygenase-2 (COX-2) is associated with poor-prognosis breast cancer. We used a nude mouse xenograft model to determine the effects of COX-2 inhibition in breast cancer. Oestrogen receptor (ER)-positive MCF7/HER2-18 and ER-negative MDAMB231 breast cancer cell lines were injected into nude mice and allowed to form tumours. Mice then received either chow containing Celecoxib (a COX-2 inhibitor) or control and tumour growth measured. Tumour proliferation, apoptosis, COX-2, lymphangiogenesis and angiogenesis were assessed by immunohistochemistry (IHC), Western blotting or Q-PCR. Celecoxib inhibited median tumour growth in MCF7/HER2-18 (58.7%, P=0.029) and MDAMB231 (46.3%, P=0.0002) cell lines compared to control. Cyclooxygenase-2 expression decreased following Celecoxib treatment (MCF7/HER2-18 median control 65.3% vs treated 22.5%, P=0.0001). Celecoxib increased apoptosis in MCF7/HER2-18 tumours (TUNEL 0.52% control vs 0.73% treated, P=0.0004) via inactivation of AKT (median pAKT(ser473) 57.3% control vs 35.5% treated, P=0.0001--confirmed at Western blotting). Q-PCR demonstrated decreased podoplanin RNA (lymphangiogenesis marker) in the MCF7/HER2-18 - median 2.9 copies treated vs 66.6 control (P=0.05) and MDAMB231-treated groups--median 160.7 copies vs 0.05 control copies (P=0.015), confirmed at IHC. Cyclooxygenase-2 is associated with high levels of activated AKT(ser473) and lymphangiogenesis in breast cancer. Cyclooxygenase-2 inhibition decreases tumour growth, and may potentially decrease recurrence, by inactivating AKT and decreasing lymphangiogenesis.
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| 2. |
- Simões, Bruno M, et al.
(författare)
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Anti-estrogen Resistance in Human Breast Tumors Is Driven by JAG1-NOTCH4-Dependent Cancer Stem Cell Activity.
- 2015
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Ingår i: Cell Reports. - : Elsevier BV. - 2211-1247. ; 12:12, s. 1968-1977
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Tidskriftsartikel (refereegranskat)abstract
- Breast cancers (BCs) typically express estrogen receptors (ERs) but frequently exhibit de novo or acquired resistance to hormonal therapies. Here, we show that short-term treatment with the anti-estrogens tamoxifen or fulvestrant decrease cell proliferation but increase BC stem cell (BCSC) activity through JAG1-NOTCH4 receptor activation both in patient-derived samples and xenograft (PDX) tumors. In support of this mechanism, we demonstrate that high ALDH1 predicts resistance in women treated with tamoxifen and that a NOTCH4/HES/HEY gene signature predicts for a poor response/prognosis in 2 ER+ patient cohorts. Targeting of NOTCH4 reverses the increase in Notch and BCSC activity induced by anti-estrogens. Importantly, in PDX tumors with acquired tamoxifen resistance, NOTCH4 inhibition reduced BCSC activity. Thus, we establish that BCSC and NOTCH4 activities predict both de novo and acquired tamoxifen resistance and that combining endocrine therapy with targeting JAG1-NOTCH4 overcomes resistance in human breast cancers.
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| 3. |
- Williams, K. E., et al.
(författare)
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Focal Adhesion Kinase and Wnt Signaling Regulate Human Ductal Carcinoma In Situ Stem Cell Activity and Response to Radiotherapy
- 2015
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Ingår i: Stem Cells. - : Oxford University Press (OUP). - 1066-5099 .- 1549-4918. ; 33:2, s. 327-341
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Tidskriftsartikel (refereegranskat)abstract
- Cancer stem cells (CSCs) can avoid or efficiently repair DNA damage from radio and chemotherapy, which suggests they play a role in disease recurrence. Twenty percentage of patients treated with surgery and radiotherapy for ductal carcinoma in situ (DCIS) of the breast recur and our previous data show that high grade DCIS have increased numbers of CSCs. Here, we investigate the role of focal adhesion kinase (FAK) and Wnt pathways in DCIS stem cells and their capacity to survive irradiation. Using DCIS cell lines and patient samples, we demonstrate that CSC-enriched populations are relatively radioresistant and possess high FAK activity. Immunohistochemical studies of active FAK in DCIS tissue show high expression was associated with a shorter median time to recurrence. Treatment with a FAK inhibitor or FAK siRNA in nonadherent and three-dimensional matrigel culture reduced mammosphere formation, and potentiated the effect of 2 Gy irradiation. Moreover, inhibition of FAK in vitro and in vivo decreased self-renewal capacity, levels of Wnt3a and B-Catenin revealing a novel FAK-Wnt axis regulating DCIS stem cell activity. Overall, these data establish that the FAK-Wnt axis is a promising target to eradicate self-renewal capacity and progression of human breast cancers.
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