0000000000075661
AUTHOR
Sami Hamdoun
showing 10 related works from this author
MCC1019, a selective inhibitor of the Polo-box domain of Polo-like kinase 1 as novel, potent anticancer candidate
2019
Polo-like kinase (PLK1) has been identified as a potential target for cancer treatment. Although a number of small molecules have been investigated as PLK1 inhibitors, many of which showed limited selectivity. PLK1 harbors a regulatory domain, the Polo box domain (PBD), which has a key regulatory function for kinase activity and substrate recognition. We report on 3-bromomethyl-benzofuran-2-carboxylic acid ethyl ester (designated: MCC1019) as selective PLK1 inhibitor targeting PLK1 PBD. Cytotoxicity and fluorescence polarization-based screening were applied to a library of 1162 drug-like compounds to identify potential inhibitors of PLK1 PBD. The activity of compound MC1019 against the PLK1…
Ca2+ signalling plays a role in celastrol‐mediated suppression of synovial fibroblasts of rheumatoid arthritis patients and experimental arthritis in…
2019
Background and purpose Celastrol exhibits anti-arthritic effects in rheumatoid arthritis (RA), but the role of celastrol-mediated Ca2+ mobilization in treatment of RA remains undefined. Here, we describe a regulatory role for celastrol-induced Ca2+ signalling in synovial fibroblasts of RA patients and adjuvant-induced arthritis (AIA) in rats. Experimental approach We used computational docking, Ca2+ dynamics and functional assays to study the sarcoplasmic/endoplasmic reticulum Ca2+ ATPase pump (SERCA). In rheumatoid arthritis synovial fibroblasts (RASFs)/rheumatoid arthritis fibroblast-like synoviocytes (RAFLS), mechanisms of Ca2+ -mediated autophagy were analysed by histological, immunohis…
SERCA and P-glycoprotein inhibition and ATP depletion are necessary for celastrol-induced autophagic cell death and collateral sensitivity in multidr…
2019
Multidrug resistance (MDR) represents an obstacle in anti-cancer therapy. MDR is caused by multiple mechanisms, involving ATP-binding cassette (ABC) transporters such as P-glycoprotein (P-gp), which reduces intracellular drug levels to sub-therapeutic concentrations. Therefore, sensitizing agents retaining effectiveness against apoptosis- or drug-resistant cancers are desired for the treatment of MDR cancers. The sarcoplasmic/endoplasmic reticulum Ca2+ ATPase (SERCA) pump is an emerging target to overcome MDR, because of its continuous expression and because the calcium transport function is crucial to the survival of tumor cells. Previous studies showed that SERCA inhibitors exhibit anti-c…
Multifactorial Modes of Action of Arsenic Trioxide in Cancer Cells as Analyzed by Classical and Network Pharmacology
2018
Arsenic trioxide is a traditional remedy in Chinese Medicine since ages. Nowadays, it is clinically used to treat acute promyelocytic leukemia (APL) by targeting PML/RARA. However, the drug’s activity is broader and the mechanisms of action in other tumor types remain unclear. In this study, we investigated molecular modes of action by classical and network pharmacological approaches. CEM/ADR5000 resistance leukemic cells were similar sensitive to As2O3 as their wild-type counterpart CCRF-CEM (resistance ratio: 1.88). Drug-resistant U87.MG ΔEGFR glioblastoma cells harboring mutated epidermal growth factor receptor were even more sensitive (collateral sensitive) than wild-type U87.MG cells (…
Cytotoxicity of 91 Kenyan indigenous medicinal plants towards human CCRF-CEM leukemia cells.
2015
Abstract Ethnopharmacological relevance Plants from Kenyan flora are traditionally used against many ailments, including cancer and related diseases. Cancer is characterized as a condition with complex signs and symptoms. Recently there are recommendations that ethnopharmacological usages such as immune and skin disorders, inflammatory, infectious, parasitic and viral diseases should be taken into account when selecting plants that treat cancer. Aim The present study was aimed at investigating the cytotoxicity of a plethora of 145 plant parts from 91 medicinal plants, most of which are used in the management of cancer and related diseases by different communities in Kenya, against CCRF-CEM …
Synthesis of novel xanthone and acridone carboxamides with potent antiproliferative activities
2020
Abstract Several new amino-substituted acridone and xanthone derivatives have been designed and synthesized, using an efficient methodology from suitable acridone- or xanthone-carboxylic acid intermediates. The antiproliferative activity of the target compounds has been evaluated against four cancer cell lines, namely breast adenocarcinoma MCF-7, acute lymphocytic leukemia CCRF-CEM, and its doxorubicin-resistant variant CEM/ADR5000 and prostate cancer PC-3 cell lines. Selected derivatives have also been tested against the urinary bladder T24 and metastatic melanoma WM266-4 cancer cell lines. Two nitro substituted acridones, bearing a basic side chain as well, were endowed with a remarkable …
Lawsone derivatives target the Wnt/β-catenin signaling pathway in multidrug-resistant acute lymphoblastic leukemia cells.
2017
Abstract Multidrug resistance (MDR) represents a serious problem in cancer treatment. One strategy to overcome this obstacle is to identify agents that are selectively lethal to MDR cells. The aim of this study was to discover novel compounds against MDR leukemia and to determine the molecular mechanisms behind collateral sensitivity. A library of 1162 compounds was tested against parental, drug-sensitive CCRF-CEM cells using the resazurin assay. A total of 302 compounds showed reasonable activity (less than 50% cell viability). Eleven out of 30 lawsone derivatives revealed considerable collateral sensitivity in MDR P-glycoprotein (Pgp)-overexpressing CEM/ADR5000 cells. They reduced β-caten…
Biopiracy of natural products and good bioprospecting practice
2016
Made available in DSpace on 2018-11-26T16:27:45Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-02-15 Deutsche Forschungsgemeinschaft Background: Biopiracy mainly focuses on the use of biological resources and/or knowledge of indigenous tribes or communities without allowing them to share the revenues generated out of economic exploitation or other non-monetary incentives associated with the resource/knowledge. Methods: Based on collaborations of scientists from five continents, we have created a communication platform to discuss not only scientific topics, but also more general issues with social relevance. This platform was termed 'PhytCancer -Phytotherapy to Fight Cancer' (www.phy…
Biopiracy versus One-World Medicine-From colonial relicts to global collaborative concepts.
2017
Abstract Background Practices of biopiracy to use genetic resources and indigenous knowledge by Western companies without benefit-sharing of those, who generated the traditional knowledge, can be understood as form of neocolonialism. Hypothesis The One-World Medicine concept attempts to merge the best of traditional medicine from developing countries and conventional Western medicine for the sake of patients around the globe. Study design Based on literature searches in several databases, a concept paper has been written. Legislative initiatives of the United Nations culminated in the Nagoya protocol aim to protect traditional knowledge and regulate benefit-sharing with indigenous communiti…
Drug Repurposing of the Anthelmintic Niclosamide to Treat Multidrug-Resistant Leukemia
2017
Multidrug resistance, a major problem that leads to failure of anticancer chemotherapy, requires the development of new drugs. Repurposing of established drugs is a promising approach for overcoming this problem. An example of such drugs is niclosamide, a known anthelmintic that is now known to be cytotoxic and cytostatic against cancer cells. In this study, niclosamide showed varying activity against different cancer cell lines. It revealed better activity against hematological cancer cell lines CCRF-CEM, CEM/ADR5000, and RPMI-8226 compared to the solid tumor cell lines MDA-MB-231, A549, and HT-29. The multidrug resistant CEM/ADR5000 cells were similar sensitive as their sensitive counterp…