Amitozyn Impairs Chromosome Segregation and Induces Apoptosis via Mitotic Checkpoint Activation.
Amitozyn Impairs Chromosome Segregation and Induces Apoptosis via Mitotic Checkpoint Activation.
PLoS One. 2013; 8(3): e57461
Herman B, Gudrun A, Potopalsky AI, Chroboczek J, Tcherniuk SO
Amitozyn (Am) is a semi-synthetic drug produced by the alkylation of major celandine (Chelidonium majus L.) alkaloids with the organophosphorous compound N,N’N’-triethylenethiophosphoramide (ThioTEPA). We show here that the treatment of living cells with Am reversibly perturbs the microtubule cytoskeleton, provoking a dose-dependent cell arrest in the M phase. Am changed the dynamics of tubulin polymerization in vitro, promoted the appearance of aberrant mitotic phenotypes in HeLa cells and induced apoptosis by the activation of caspase-9, caspase-3 and PARP, without inducing DNA breaks. Am treatment of HeLa cells induced changes in the phosphorylation of the growth suppressor pRb that coincided with maximum mitotic index. The dose-dependent and reversible anti-proliferative effect of Am was observed in several transformed cell lines. Importantly, the drug was also efficient against multidrug-resistant, paclitaxel-resistant or p53-deficient cells. Our results thus open the way to further pre-clinical evaluation of Am. HubMed – drug
Down-regulation of canonical and up-regulation of non-canonical wnt signalling in the carcinogenic process of squamous cell lung carcinoma.
PLoS One. 2013; 8(3): e57393
Bartis D, Csongei V, Weich A, Kiss E, Barko S, Kovacs T, Avdicevic M, D’Souza VK, Rapp J, Kvell K, Jakab L, Nyitrai M, Molnar TF, Thickett DR, Laszlo T, Pongracz JE
The majority of lung cancers (LC) belong to the non-small cell lung carcinoma (NSCLC) type. The two main NSCLC sub-types, namely adenocarcinoma (AC) and squamous cell carcinoma (SCC), respond differently to therapy. Whereas the link between cigarette smoke and lung cancer risk is well established, the relevance of non-canonical Wnt pathway up-regulation detected in SCC remains poorly understood. The present study was undertaken to investigate further the molecular events in canonical and non-canonical Wnt signalling during SCC development. A total of 20 SCC and AC samples with matched non-cancerous controls were obtained after surgery. TaqMan array analysis confirmed up-regulation of non-canonical Wnt5a and Wnt11 and identified down-regulation of canonical Wnt signalling in SCC samples. The molecular changes were tested in primary small airway epithelial cells (SAEC) and various lung cancer cell lines (e.g. A549, H157, etc). Our studies identified Wnt11 and Wnt5a as regulators of cadherin expression and potentiated relocation of ?-catenin to the nucleus as an important step in decreased cellular adhesion. The presented data identifies additional details in the regulation of SCC that can aid identification of therapeutic drug targets in the future. HubMed – drug
Cellular Effects of Curcumin on Plasmodium falciparum Include Disruption of Microtubules.
PLoS One. 2013; 8(3): e57302
Chakrabarti R, Rawat PS, Cooke BM, Coppel RL, Patankar S
Curcumin has been widely investigated for its myriad cellular effects resulting in reduced proliferation of various eukaryotic cells including cancer cells and the human malaria parasite Plasmodium falciparum. Studies with human cancer cell lines HT-29, Caco-2, and MCF-7 suggest that curcumin can bind to tubulin and induce alterations in microtubule structure. Based on this finding, we investigated whether curcumin has any effect on P. falciparum microtubules, considering that mammalian and parasite tubulin are 83% identical. IC50 of curcumin was found to be 5 µM as compared to 20 µM reported before. Immunofluorescence images of parasites treated with 5 or 20 µM curcumin showed a concentration-dependent effect on parasite microtubules resulting in diffuse staining contrasting with the discrete hemispindles and subpellicular microtubules observed in untreated parasites. The effect on P. falciparum microtubules was evident only in the second cycle for both concentrations tested. This diffuse pattern of tubulin fluorescence in curcumin treated parasites was similar to the effect of a microtubule destabilizing drug vinblastine on P. falciparum. Molecular docking predicted the binding site of curcumin at the interface of alpha and beta tubulin, similar to another destabilizing drug colchicine. Data from predicted drug binding is supported by results from drug combination assays showing antagonistic interactions between curcumin and colchicine, sharing a similar binding site, and additive/synergistic interactions of curcumin with paclitaxel and vinblastine, having different binding sites. This evidence suggests that cellular effects of curcumin are at least, in part, due to its perturbing effect on P. falciparum microtubules. The action of curcumin, both direct and indirect, on P. falciparum microtubules is discussed. HubMed – drug
Correspondence (letter to the editor): Additional Important Drug Interactions.
Dtsch Arztebl Int. 2013 Feb; 110(8): 133
Lehmann K
Everybody’s welcome: The big tent approach to epigenetic drug discovery.
Drug Discov Today Ther Strateg. 2012; 9(2-3): e75-e81
Green EM, Gozani O
The rapid expansion of epigenetics research is fueled by the increasing understanding that epigenetic processes are critical to regulating cellular development and dysfunction of epigenetic programs is responsible for a diverse set of human pathologies, including cancer, autoimmune and neurodegenerative diseases. The expansive set of components contributing to epigenetic disease mechanisms and the often reversible nature of epigenetic lesions provide prime opportunities for the development of novel therapeutic strategies. Here, we provide an overview of epigenetics and its relationship to disease, discuss current epigenetics-based therapies and suggest new avenues for the identification of therapies targeting deregulated epigenetic programs in disease. HubMed – drug
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