Suitability of transiently expressed antibodies for clinical studies: product quality consistency at different production scales.

Transgenic human monoclonal antibodies derived from humanized mice against different epitopes of the Middle East respiratory syndrome coronavirus (MERS-CoV), and chimeric llama-human bispecific heavy chain-only antibodies targeting the Rift Valley fever virus (RVFV), were produced using a CHO-based transient expression system. Two lead candidates were assessed for each model virus before selecting and progressing one lead molecule. MERS-7.

Improved anticancer and antiparasitic activity of new lawsone Mannich bases.

Substituted lawsone Mannich bases 2a-e, 3a-e and 4a-e were prepared and tested for their biological activities. The new fatty alkyl substituted compounds 2a-c exhibited strong and selective growth inhibitory activities in the low one-digit micromolar and sub-micromolar range against a panel of human cancer cell lines associated with ROS formation. In addition, compounds 2a-c revealed sub-micromolar anti-trypanosomal activities against parasitic Trypanosoma brucei brucei cells via deformation of the microtubule cytoskeleton.

Combretastatin A-4 derived 5-(1-methyl-4-phenyl-imidazol-5-yl)indoles with superior cytotoxic and anti-vascular effects on chemoresistant cancer cells and tumors.

5-(1-Methyl-4-phenyl-imidazol-5-yl)indoles 5 were prepared and tested as analogs of the natural vascular-disrupting agent combretastatin A-4 (CA-4). The 3-bromo-4,5-dimethoxyphenyl derivative 5c was far more active than CA-4 with low nanomolar IC50 concentrations against multidrug-resistant KB-V1/Vbl cervix and MCF-7/Topo mamma carcinoma cells, and also against CA-4-resistant HT-29 colon carcinoma cells. While not interfering markedly with the polymerization of tubulin in vitro, indole 5c completely disrupted the microtubule cytoskeleton of cancer cells at low concentrations.

Role of JNK and NF-κB in mediating the effect of combretastatin A-4 and brimamin on endothelial and carcinoma cells.

Purpose: The 4,5-diarylimidazole brimamin is an analog of the natural vascular-disrupting agent combretastatin A-4 (CA-4) with improved water solubility, tolerance by animals and efficacy in multidrug-resistant tumors. Here, we aimed at identifying the major mechanisms underlying the in vitro and in vivo actions of brimamin on endothelial and carcinoma cells, including vascularization.

Methods: The contribution of specific signaling kinases to the effects of brimamin on cytoskeleton organization and the viability and differentiation of endothelial cells was assessed by MTT and tube formation assays in the presence or absence of specific kinase inhibitors.

4-(1-Ethyl-4-anisyl-imidazol-5-yl)-N-hydroxycinnamide - A new pleiotropic HDAC inhibitor targeting cancer cell signalling and cytoskeletal organisation.

Histone deacetylases (HDAC) which play a crucial role in cancer cell proliferation are promising drug targets. However, HDAC inhibitors (HDACi) modelled on natural hydroxamic acids such as trichostatin A frequently lead to resistance or even an increased agressiveness of tumours. As a workaround we developed 4-(1-ethyl-4-anisyl-imidazol-5-yl)-N-hydroxycinnamide (etacrox), a hydroxamic acid that combines HDAC inhibition with synergistic effects of the 4,5-diarylimidazole residue.

Combretastatin A-4 derived imidazoles show cytotoxic, antivascular, and antimetastatic effects based on cytoskeletal reorganisation.

Introduction: Combretastatin A-4 (CA-4) is a natural cis-stilbene which interferes with the cellular tubulin dynamics and which selectively destroys tumour blood vessels. Its pharmacological shortcomings such as insufficient chemical stability, water solubility, and cytotoxicity can be remedied by employing its imidazole derivatives.

Methods: We studied 11 halogenated imidazole derivatives of CA-4 for their effects on the microtubule and actin cytoskeletons of cancer and endothelial cells and on the propensity of these cells to migrate across tissue barriers or to form blood vessel-like tubular structures.

Biological evaluation of 4,5-diarylimidazoles with hydroxamic acid appendages as novel dual mode anticancer agents.

Purpose: New (4-aryl-1-methylimidazol-5-yl)cinnamoylhydroxamic acids were prepared as potential dual mode anticancer agents combining the antivascular effect of the 4,5-diarylimidazole moiety and the histone deacetylases (HDAC) inhibition by the cinnamoyl hydroxamate.

Methods: Their antiproliferative activity against a panel of primary cells and cancer cell lines was determined by MTT assays and their apoptosis induction by caspase-3 activation. Their ability to reduce the activity of HDAC was measured by enzymatic assays and Western blot analyses of cellular HDAC substrates.

Ferrocene and (arene)ruthenium(II) complexes of the natural anticancer naphthoquinone plumbagin with enhanced efficacy against resistant cancer cells and a genuine mode of action.

A series of ferrocene and (arene)ruthenium(II) complexes attached to the naturally occurring anticancer naphthoquinones plumbagin and juglone was tested for efficacy against various cancer cell lines and for alterations in the mode of action. The plumbagin ferrocene and (p-cymene)Ru(II) conjugates 1c and 2a overcame the multi-drug drug resistance of KB-V1/Vbl cervix carcinoma cells and showed IC50 (72 h) values around 1 μM in growth inhibition assays using 3-(4,5-dimethyl-2-yl)-2,5-diphenyltetrazolium bromide (MTT). They were further investigated for their influence on the cell cycle of KB-V1/Vbl and HCT-116 colon carcinoma cells, on the generation of reactive oxygen species (ROS) by the latter cell line, for their substrate character for the P-glycoprotein drug eflux pump via the calcein-AM efflux assays, and for DNA affinity by the electrophoretic mobility shift assay (EMSA).

Effects of the tumor-vasculature-disrupting agent verubulin and two heteroaryl analogues on cancer cells, endothelial cells, and blood vessels.

Two analogues of the discontinued tumor vascular-disrupting agent verubulin (Azixa®, MPC-6827, 1) featuring benzo-1,4-dioxan-6-yl (compound 5 a) and N-methylindol-5-yl (compound 10) residues instead of the para-anisyl group on the 4-(methylamino)-2-methylquinazoline pharmacophore, were prepared and found to exceed the antitumor efficacy of the lead compound. They were antiproliferative with single-digit nanomolar IC50 values against a panel of nine tumor cell lines, while not affecting nonmalignant fibroblasts. Indole 10 surpassed verubulin in seven tumor cell lines including colon, breast, ovarian, and germ cell cancer cell lines.

Effects of chrysin, apigenin, genistein and their homoleptic copper(II) complexes on the growth and metastatic potential of cancer cells.

The (iso-)flavonoids chrysin 1, apigenin 2, genistein 3 and their homoleptic copper(II) complexes 4-6 were compared for general cancer cell growth inhibition and for antimetastatic effects on rapidly proliferating and metastasizing 518A2 melanoma cells. The complexes 4-6 were three to five times more active than the free flavonoids in cytotoxicity assays with MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] against 518A2 melanoma, HCT-116 colon, KB-V1/Vbl cervix, and MCF-7/Topo breast carcinoma cells. This activity correlated with an arrest of the cell cycle of 518A2 melanoma cells at the G2/M transition.

Gold(I)-NHC complexes of antitumoral diarylimidazoles: structures, cellular uptake routes and anticancer activities.

Five new heterocyclic gold carbene complexes were prepared, four chlorido-[1,3-dimethyl-4,5-diarylimidazol-2-ylidene]gold complexes 6a-d and a chlorido-[1,3-dibenzylimidazol-2-ylidene]gold complex 11, and three of them were characterised by X-ray single crystal analyses. They were tested for cytotoxicity against a panel of four human cancer cell lines and non-malignant fibroblasts, for tubulin interaction, and for the pathways of their uptake into 518A2 melanoma cells. All complexes showed cytotoxic activity in the micromolar IC(50) range with distinct selectivities for certain cell lines.

Cancer selective metallocenedicarboxylates of the fungal cytotoxin illudin M.

The diester 2a obtained from 1,1'-ferrocenedicarboxylic acid and the highly and indiscriminately cytotoxic fungal metabolite illudin M (1) displayed antiproliferative activity at submicromolar IC(50) (72 h) values against a panel of eight cancer cell lines. Compound 2a was about 40 times less toxic than 1 to nonmalignant human foreskin fibroblasts (HF). The analogous bis(illudinyl M) 1,1'-ruthenocenedicarboxylate (2b) exhibited submicromolar IC(50) (72 h) values only against MDA-MB-231 and MCF-7/Topo breast carcinoma and HL-60 leukemia cells.

Modification of uptake and subcellular distribution of doxorubicin by N-acylhydrazone residues as visualised by intrinsic fluorescence.

Purpose: Doxorubicin (1) is commonly used in the treatment of a wide range of cancers. Some N-acylhydrazones of 1 were previously found to have an improved tumour and organ selectivity. In order to clarify the molecular basis for this effect, the cellular uptake into various cancer cells and the localisation in PtK(2) potoroo kidney cells of 1 and its N-acylhydrazones derived from heptadecanoic acid (2) and 11-(menthoxycarbonyl)undecanoic acid (3) were studied drawing on their intrinsic fluorescence.

Cellular localisation of antitumoral 6-alkyl thymoquinones revealed by an alkyne-azide click reaction and the streptavidin-biotin system.

The subcellular distribution and accumulation of thymoquinone 1, a natural anticancer agent, has hitherto been unknown. We prepared 6-(dec-9-ynyl)thymoquinone 3, an alkyne-labelled derivative with anticancer activity similar to that of its parent compound 1. Alkyne 3 was seen, after a Huisgen-type click reaction with 3-azido-7-hydroxycoumarin, to accumulate in distinct compartments of the nuclei of PtK(2) potoroo kidney cells, and in adjoining regions that were stained with an antibody specific for the Golgi apparatus.