Displaying publications 21 - 23 of 23 in total

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  1. Jabbarzadeh Kaboli P, Leong MP, Ismail P, Ling KH
    Pharmacol Rep, 2019 Feb;71(1):13-23.
    PMID: 30343043 DOI: 10.1016/j.pharep.2018.07.005
    BACKGROUND: Berberine is an alkaloid plant-based DNA intercalator that affects gene regulation, particularly expression of oncogenic and tumor suppressor proteins. The effects of berberine on different signaling proteins remains to be elucidated. The present study aimed to identify the effects of berberine against key oncogenic proteins in breast cancer cells.

    METHODS: Molecular docking and molecular dynamics simulations were used for EGFR, p38, ERK1/2, and AKT. The effects of berberine and lapatinib on MAPK and PI3K pathways in MDA-MB231 and MCF-7 cells were evaluated using immunoflorescence assays, and the amounts of phosphorylated kinases were compared to total kinases after treating with different concentrations of berberine.

    RESULTS: Simulations showed berberine accurately interacted with EGFR, AKT, P38, and ERK1/2 active sites in silico (scores = -7.57 to -7.92 Kcal/mol) and decreased the levels of active forms of corresponding enzymes in both cell lines; however, berberine binding to p38 showed less stability. Cytotoxicity analysis indicated that MDA-MB231 cells were resistant to berberine compared to MCF-7 cells [72 h IC50 = 50 versus 15 μM, respectively). Also, lapatinib strongly activated AKT but suppressed EGFR in MDA-MB231 cells. The activity of EGFR, AKT, P38, and ERK1/2 were affected by berberine; however, berberine dramatically reduced EGFR and AKT phosphorylation.

    CONCLUSION: By way of its multikinase inhibitory effects, berberine might be a useful replacement for lapatinib, an EGFR inhibitor which can cause acquired drug resistance in patients.

    Matched MeSH terms: p38 Mitogen-Activated Protein Kinases/metabolism
  2. Dyari HRE, Rawling T, Chen Y, Sudarmana W, Bourget K, Dwyer JM, et al.
    FASEB J, 2017 12;31(12):5246-5257.
    PMID: 28798154 DOI: 10.1096/fj.201700033R
    A saturated analog of the cytochrome P450-mediated ω-3-17,18-epoxide of ω-3-eicosapentaenoic acid (C20E) activated apoptosis in human triple-negative MDA-MB-231 breast cancer cells. This study evaluated the apoptotic mechanism of C20E. Increased cytosolic cytochrome c expression and altered expression of pro- and antiapoptotic B-cell lymphoma-2 proteins indicated activation of the mitochondrial pathway. Caspase-3 activation by C20E was prevented by pharmacological inhibition and silencing of the JNK and p38 MAP kinases (MAPK), upstream MAPK kinases MKK4 and MKK7, and the upstream MAPK kinase kinase apoptosis signal-regulating kinase 1 (ASK1). Silencing of the death receptor TNF receptor 1 (TNFR1), but not Fas, DR4, or DR5, and the adapters TRADD and TNF receptor-associated factor 2, but not Fas-associated death domain, prevented C20E-mediated apoptosis. B-cell lymphoma-2 homology 3-interacting domain death agonist (Bid) cleavage by JNK/p38 MAPK linked the extrinsic and mitochondrial pathways of apoptosis. In further studies, an antibody against the extracellular domain of TNFR1 prevented apoptosis by TNF-α but not C20E. These findings suggest that C20E acts intracellularly at TNFR1 to activate ASK1-MKK4/7-JNK/p38 MAPK signaling and to promote Bid-dependent mitochondrial disruption and apoptosis. Inin vivostudies, tumors isolated from C20E-treated nu/nu mice carrying MDA-MB-231 xenografts showed increased TUNEL staining and decreased Ki67 staining, reflecting increased apoptosis and decreased proliferation, respectively. ω-3-Epoxy fatty acids like C20E could be incorporated into treatments for triple-negative breast cancers.-Dyari, H. R. E., Rawling, T., Chen, Y., Sudarmana, W., Bourget, K., Dwyer, J. M., Allison, S. E., Murray, M. A novel synthetic analogue of ω-3 17,18-epoxyeicosatetraenoic acid activates TNF receptor-1/ASK1/JNK signaling to promote apoptosis in human breast cancer cells.
    Matched MeSH terms: p38 Mitogen-Activated Protein Kinases/metabolism
  3. Wong SW, Tiong KH, Kong WY, Yue YC, Chua CH, Lim JY, et al.
    Breast Cancer Res Treat, 2011 Jul;128(2):301-13.
    PMID: 20686837 DOI: 10.1007/s10549-010-1055-0
    Recent gene expression profiling studies have identified five breast cancer subtypes, of which the basal-like subtype is the most aggressive. Basal-like breast cancer poses serious clinical challenges as there are currently no targeted therapies available to treat it. Although there is increasing evidence that these tumors possess specific sensitivity to cisplatin, its success is often compromised due to its dose-limiting nephrotoxicity and the development of drug resistance. To overcome this limitation, our goal was to maximize the benefits associated with cisplatin therapy through drug combination strategies. Using a validated kinase inhibitor library, we showed that inhibition of the mTOR, TGFβRI, NFκB, PI3K/AKT, and MAPK pathways sensitized basal-like MDA-MB-468 cells to cisplatin treatment. Further analysis demonstrated that the combination of the mTOR inhibitor rapamycin and cisplatin generated significant drug synergism in basal-like MDA-MB-468, MDA-MB-231, and HCC1937 cells but not in luminal-like T47D or MCF-7 cells. We further showed that the synergistic effect of rapamycin plus cisplatin on basal-like breast cancer cells was mediated through the induction of p73. Depletion of endogenous p73 in basal-like cells abolished these synergistic effects. In conclusion, combination therapy with mTOR inhibitors and cisplatin may be a useful therapeutic strategy in the treatment of basal-like breast cancers.
    Matched MeSH terms: p38 Mitogen-Activated Protein Kinases/metabolism
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