77 research outputs found

    Conditional reprogramming and long-term expansion of normal and tumor cells from human biospecimens

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    Historically, it has been difficult to propagate cells in vitro that are derived directly from human tumors or healthy tissue. However, in vitro preclinical models are essential tools for both the study of basic cancer biology and the promotion of translational research, including drug discovery and drug target identification. This protocol describes conditional reprogramming (CR), which involves coculture of irradiated mouse fibroblast feeder cells with normal and tumor human epithelial cells in the presence of a Rho kinase inhibitor (Y-27632). CR cells can be used for various applications, including regenerative medicine, drug sensitivity testing, gene expression profiling and xenograft studies. The method requires a pathologist to differentiate healthy tissue from tumor tissue, and basic tissue culture skills. The protocol can be used with cells derived from both fresh and cryopreserved tissue samples. As approximately 1 million cells can be generated in 7 d, the technique is directly applicable to diagnostic and predictive medicine. Moreover, the epithelial cells can be propagated indefinitely in vitro, yet retain the capacity to become fully differentiated when placed into conditions that mimic their natural environment

    Molecular targets for anticancer redox chemotherapy and cisplatin-induced ototoxicity: the role of curcumin on pSTAT3 and Nrf-2 signalling

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    In oncology, an emerging paradigm emphasises molecularly targeted approaches for cancer prevention and therapy and the use of adjuvant chemotherapeutics to overcome cisplatin limitations. Owing to their safe use, some polyphenols, such as curcumin, modulate important pathways or molecular targets in cancers. This paper focuses on curcumin as an adjuvant molecule to cisplatin by analysing its potential implications on the molecular targets, signal transducer and activator of transcription 3 (STAT3) and NF-E2 p45-related factor 2 (Nrf-2), in tumour progression and cisplatin resistance in vitro and the adverse effect ototoxicity in vivo

    A new role for tamoxifen in oestrogen receptor-negative breast cancer when it is combined with epigallocatechin gallate

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    We have previously shown that tamoxifen+epigallocatechin gallate (EGCG) is synergistically cytotoxic towards oestrogen receptor (ER)-negative breast cancer cells. To determine if this response would correlate with significant tumour suppression in vivo, athymic nude female mice were implanted with MDA-MB-231 cells and treated with tamoxifen, EGCG, EGCG+tamoxifen, or vehicle control for 10 weeks. Tumour volume in EGCG- (25 mg kg−1)+tamoxifen (75 μg kg−1)-treated mice decreased by 71% as compared with vehicle control (P<0.05), whereas tumour weight was decreased by 80% compared with control (P<0.01). Epigallocatechin gallate treatment did not alter ER protein expression in MDA-MB-231 cells and thus was not a mechanism for the observed tumour suppression. However, western blotting of tumour extracts demonstrated that epidermal growth factor receptor (EGFR; 85% lower than control), pEGFR (78% lower than control), mammalian target of rapamycin (mTOR; 78% lower than control), and CYP1B1 (75% lower than control) were significantly lower after the combination treatment as compared with all other treatments. Nuclear factor-κB (NF-κB), b-Raf, p-MEK, S6K, 4EBP1, Akt, vascular EGFR-1 (VEGFR-1) and VEGF expressions were decreased in control but not in the individual treatments, whereas MEK, phospholipase D 1/2, TGFα, and ERK expressions were not changed after any treatment. The results demonstrate that tamoxifen at realistic doses (75 μg kg−1) can suppress the growth of ER-negative breast cancer when combined with EGCG. In addition, the dominant mechanism for tumour suppression is the concomitant decrease in tumour protein expressions of mTOR and the EGFR

    Curcuminoid Binding to Embryonal Carcinoma Cells: Reductive Metabolism, Induction of Apoptosis, Senescence, and Inhibition of Cell Proliferation

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    Curcumin preparations typically contain a mixture of polyphenols, collectively referred to as curcuminoids. In addition to the primary component curcumin, they also contain smaller amounts of the co-extracted derivatives demethoxycurcumin and bisdemethoxycurcumin. Curcuminoids can be differentially solubilized in serum, which allows for the systematic analysis of concentration-dependent cellular binding, biological effects, and metabolism. Technical grade curcumin was solubilized in fetal calf serum by two alternative methods yielding saturated preparations containing either predominantly curcumin (60%) or bisdemethoxycurcumin (55%). Continual exposure of NT2/D1 cells for 4–6 days to either preparation in cell culture media reduced cell division (1–5 µM), induced senescence (6–7 µM) or comprehensive cell death (8–10 µM) in a concentration-dependent manner. Some of these effects could also be elicited in cells transiently exposed to higher concentrations of curcuminoids (47 µM) for 0.5–4 h. Curcuminoids induced apoptosis by generalized activation of caspases but without nucleosomal fragmentation. The equilibrium binding of serum-solubilized curcuminoids to NT2/D1 cells incubated with increasing amounts of curcuminoid-saturated serum occurred with apparent overall dissociation constants in the 6–10 µM range. However, the presence of excess free serum decreased cellular binding in a hyperbolic manner. Cellular binding was overwhelmingly associated with membrane fractions and bound curcuminoids were metabolized in NT2/D1 cells via a previously unidentified reduction pathway. Both the binding affinities for curcuminoids and their reductive metabolic pathways varied in other cell lines. These results suggest that curcuminoids interact with cellular binding sites, thereby activating signal transduction pathways that initiate a variety of biological responses. The dose-dependent effects of these responses further imply that distinct cellular pathways are sequentially activated and that this activation is dependent on the affinity of curcuminoids for the respective binding sites. Defined serum-solubilized curcuminoids used in cell culture media are thus suitable for further investigating the differential activation of signal transduction pathways

    Chemical characterisation and the anti-inflammatory, anti-angiogenic and antibacterial properties of date fruit (Phoenix dactylifera L.)

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    Ethnopharmacological relevance: Date fruit, Phoenix dactylifera L. has traditionally been used as a medicine in many cultures for the treatment of a range of ailments such as stomach and intestinal disorders, fever, oedema, bronchitis and wound healing. Aim of the review: The present review aims to summarise the traditional use and application of Phoenix dactylifera date fruit in different ethnomedical systems, additionally the botany and phytochemistry are identified. Critical evaluation of in vitro and in vitro studies examining date fruit in relation to anti-inflammatory, anti-angiogenic and antimicrobial activities are outlined. Key Findings: The ethnomedical use of Phoenix dactylifera in the treatment of inflammatory disease has been previously identified and reported. Furthermore, date fruit and date fruit co-products such as date syrup are rich sources of polyphenols, anthocyanins, sterols and carotenoids. In vitro studies have demonstrated that date fruit exhibits antibacterial, anti-inflammatory and anti-angiogenic activity. The recent interest in the identification of the numerous health benefits of dates using in vitro and in vivo studies have confirmed that date fruit and date syrup have beneficial health effects that can be attributed to the presence of natural bioactive compounds. Conclusions: Date fruit and date syrup have therapeutic properties, which have the potential to be beneficial to health. However, more investigations are needed to quantify and validate these effects

    Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases

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    The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular "reactive oxygen species" (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation. We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation). The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible. This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference
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