135 research outputs found

    Growth, profits and technological choice: The case of the Lancashire cotton textile industry

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    Using Lancashire textile industry company case studies and financial records, mainly from the period just before the First World War, the processes of growth and decline are re-examined. These are considered by reference to the nature of Lancashire entrepreneurship and the impact on technological choice. Capital accumulation, associated wealth distributions and the character of Lancashire business organisation were sybiotically linked to the success of the industry before 1914. However, the legacy of that accumulation in later decades, chronic overcapacity, formed a barrier to reconstruction and enhanced the preciptious decline of a once great industry

    Markers of Tumor-Initiating Cells Predict Chemoresistance in Breast Cancer

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    PURPOSE: Evidence is lacking whether the number of breast tumor-initiating cells (BT-ICs) directly correlates with the sensitivity of breast tumors to chemotherapy. Here, we evaluated the association between proportion of BT-ICs and chemoresistance of the tumors. METHODS: Immunohistochemical staining(IHC) was used to examine the expression of aldehyde dehydrogenase 1 (ALDH1) and proliferating cell nuclear antigen, and TUNEL was used to detect the apoptosis index. The significance of various variables in patient survival was analyzed using a Cox proportional hazards model. The percentage of BT-ICs in breast cancer cell lines and primary breast tumors was determined by ALDH1 enzymatic assay, CD44(+)/CD24(-) phenotype and mammosphere formation assay. RESULTS: ALDH1 expression determined by IHC in primary breast cancers was associated with poor clinical response to neoadjuvant chemotherapy and reduced survival in breast cancer patients. Breast tumors that contained higher proportion of BT-ICs with CD44(+)/CD24(-) phenotype, ALDH1 enzymatic activity and sphere forming capacity were more resistant to neoadjuvant chemotherapy. Chemoresistant cell lines AdrR/MCF-7 and SK-3rd, had increased number of cells with sphere forming capacity, CD44(+)/CD24(-) phenotype and side-population. Regardless the proportion of T-ICs, FACS-sorted CD44(+)/CD24(-) cells that derived from primary tumors or breast cancer lines were about 10-60 fold more resistant to chemotherapy relative to the non- CD44(+)/CD24(-) cells and their parental cells. Furthermore, our data demonstrated that MDR1 (multidrug resistance 1) and ABCG2 (ATP-binding cassette sub-family G member 2) were upregulated in CD44(+)/CD24(-) cells. Treatment with lapatinib or salinomycin reduced the proportion of BT-ICs by nearly 50 fold, and thus enhanced the sensitivity of breast cancer cells to chemotherapy by around 30 fold. CONCLUSIONS: These data suggest that the proportion of BT-ICs is associated with chemotherapeutic resistance of breast cancer. It highlights the importance of targeting T-ICs, rather than eliminating the bulk of rapidly dividing and terminally differentiated cells, in novel anti-cancer strategies

    Rapid Selection and Proliferation of CD133(+) Cells from Cancer Cell Lines: Chemotherapeutic Implications

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    Cancer stem cells (CSCs) are considered a subset of the bulk tumor responsible for initiating and maintaining the disease. Several surface cellular markers have been recently used to identify CSCs. Among those is CD133, which is expressed by hematopoietic progenitor cells as well as embryonic stem cells and various cancers. We have recently isolated and cultured CD133 positive [CD133(+)] cells from various cancer cell lines using a NASA developed Hydrodynamic Focusing Bioreactor (HFB) (Celdyne, Houston, TX). For comparison, another bioreactor, the rotary cell culture system (RCCS) manufactured by Synthecon (Houston, TX) was used. Both the HFB and the RCCS bioreactors simulate aspects of hypogravity. In our study, the HFB increased CD133(+) cell growth from various cell lines compared to the RCCS vessel and to normal gravity control. We observed a (+)15-fold proliferation of the CD133(+) cellular fraction with cancer cells that were cultured for 7-days at optimized conditions. The RCCS vessel instead yielded a (−)4.8-fold decrease in the CD133(+)cellular fraction respect to the HFB after 7-days of culture. Interestingly, we also found that the hypogravity environment of the HFB greatly sensitized the CD133(+) cancer cells, which are normally resistant to chemo treatment, to become susceptible to various chemotherapeutic agents, paving the way to less toxic and more effective chemotherapeutic treatment in patients. To be able to test the efficacy of cytotoxic agents in vitro prior to their use in clinical setting on cancer cells as well as on cancer stem cells may pave the way to more effective chemotherapeutic strategies in patients. This could be an important advancement in the therapeutic options of oncologic patients, allowing for more targeted and personalized chemotherapy regimens as well as for higher response rates

    Malignant phyllodes tumors display mesenchymal stem cell features and aldehyde dehydrogenase/disialoganglioside identify their tumor stem cells

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    INTRODUCTION: Although breast phyllodes tumors are rare, there is no effective therapy other than surgery. Little is known about their tumor biology. A malignant phyllodes tumor contains heterologous stromal elements, and can transform into rhabdomyosarcoma, liposarcoma and osteosarcoma. These versatile properties prompted us to explore their possible relationship to mesenchymal stem cells (MSCs) and to search for the presence of cancer stem cells (CSCs) in phyllodes tumors. METHODS: Paraffin sections of malignant phyllodes tumors were examined for various markers by immunohistochemical staining. Xenografts of human primary phyllodes tumors were established by injecting freshly isolated tumor cells into the mammary fat pad of non-obese diabetic-severe combined immunodeficient (NOD-SCID) mice. To search for CSCs, xenografted tumor cells were sorted into various subpopulations by flow cytometry and examined for their in vitro mammosphere forming capacity, in vivo tumorigenicity in NOD-SCID mice and their ability to undergo differentiation. RESULTS: Immunohistochemical analysis revealed the expression of the following 10 markers: CD44, CD29, CD106, CD166, CD105, CD90, disialoganglioside (GD2), CD117, Aldehyde dehydrogenase 1 (ALDH), and Oct-4, and 7 clinically relevant markers (CD10, CD34, p53, p63, Ki-67, Bcl-2, vimentin, and Globo H) in all 51 malignant phyllodes tumors examined, albeit to different extents. Four xenografts were successfully established from human primary phyllodes tumors. In vitro, ALDH(+) cells sorted from xenografts displayed approximately 10-fold greater mammosphere-forming capacity than ALDH(-) cells. GD2(+) cells showed a 3.9-fold greater capacity than GD2(-) cells. ALDH(+)/GD2(+)cells displayed 12.8-fold greater mammosphere forming ability than ALDH(-)/GD2(-) cells. In vivo, the tumor-initiating frequency of ALDH(+)/GD2(+) cells were up to 33-fold higher than that of ALDH(+) cells, with as few as 50 ALDH(+)/GD2(+) cells being sufficient for engraftment. Moreover, we provided the first evidence for the induction of ALDH(+)/GD2(+) cells to differentiate into neural cells of various lineages, along with the observation of neural differentiation in clinical specimens and xenografts of malignant phyllodes tumors. ALDH(+) or ALDH(+)/GD2(+) cells could also be induced to differentiate into adipocytes, osteocytes or chondrocytes. CONCLUSIONS: Our findings revealed that malignant phyllodes tumors possessed many characteristics of MSC, and their CSCs were enriched in ALDH(+) and ALDH(+)/GD2(+) subpopulations

    Notch Lineages and Activity in Intestinal Stem Cells Determined by a New Set of Knock-In Mice

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    The conserved role of Notch signaling in controlling intestinal cell fate specification and homeostasis has been extensively studied. Nevertheless, the precise identity of the cells in which Notch signaling is active and the role of different Notch receptor paralogues in the intestine remain ambiguous, due to the lack of reliable tools to investigate Notch expression and function in vivo. We generated a new series of transgenic mice that allowed us, by lineage analysis, to formally prove that Notch1 and Notch2 are specifically expressed in crypt stem cells. In addition, a novel Notch reporter mouse, Hes1-EmGFPSAT, demonstrated exclusive Notch activity in crypt stem cells and absorptive progenitors. This roster of knock-in and reporter mice represents a valuable resource to functionally explore the Notch pathway in vivo in virtually all tissues

    Breast cancer stem cells: tools and models to rely on

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    There is increasing evidence for the "cancer stem cell (CSC) hypothesis", which holds that cancers are driven by a cellular component that has stem cell properties, including self-renewal, tumorigenicity and multi-lineage differentiation capacity. Researchers and oncologists see in this model an explanation as to why cancer may be so difficult to cure, as well as a promising ground for novel therapeutic strategies. Given the specific stem cell features of self-renewal and differentiation, which drive tumorigenesis and contribute to cellular heterogeneity, each marker and assay designed to isolate and characterize CSCs has to be functionally validated. In this review, we survey tools and markers available or promising to identify breast CSCs. We review the main models used to study breast CSCs and how they challenge the CSC hypothesis

    Cyclooxygenase-2 inhibition: effects on tumour growth, cell cycling and lymphangiogenesis in a xenograft model of breast cancer

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    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 pAKTser473 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 AKTser473 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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