Enhanced DNA damage and anti-proliferative activity of a novel ruthenium complex with a chlorambucil-decorated ligand

Triphenylphosphine substitution reactions of [RuCl(PPh3)2(tpm)]Cl, 1, featuring tris(pyrazolyl)methane (tpm) as ligand, with the chlorambucil-decorated pyridine ligand PyCA, 3-aminopyridine (PyNH2) and 4-pyridinemethanol (PyOH) afforded the corresponding pyridine complexes 2-4 in high yields. PyCA was preliminarily obtained via esterification of 4-pyridinemethanol with chlorambucil. The new compounds PyCA and 2-3 were characterized by IR and multinuclear NMR spectroscopy. Additionally, the structure of 3 was ascertained by single crystal X-ray diffraction. The in vitro anti-proliferative activity of 2-4 and PyCA was determined against a panel of cancer cell lines, outlining 2 as the most performing compound. Targeted studies were subsequently undertaken using 2 to elucidate mechanistic aspects, including the assessment of ruthenium cellular uptake, cell cycle arrest, production of reactive oxygen species (ROS), western blotting and DNA damage (comet test). Overall, data highlight that the anticancer activity provided by 2 primarily affects the mitochondria pathway with a potential additional contribution from DNA damage.

Chlorambucil-Bearing Hybrid Molecules in the Development of Potential Anticancer Agents

Increasing cases of cancer have been a primary concern in recent decades. Developing new chemotherapeutics is challenging and has been faced with limitations, such as multidrug resistance, poor specificity, selectivity, and toxicity. The aforementioned factors contribute to treatment failure. Hybrid compounds have features that can overcome the limitations mentioned above. Chlorambucil, an anticancer drug that is used to treat prostate and breast cancer, suffers from poor aqueous solubility and specificity, a short half-life, and severe side effects, including anaemia and bone marrow suppression. It compromises the immune system, resulting in treatment failure. Hence, its combination with other pharmacophores has been reported to result in effective anticancer agents with fewer side effects and high therapeutic outcomes. Furthermore, this review gives an update (2010 to date) on the developments of chlorambucil hybrid compounds with anticancer activity, and the structure-activity relationship (SAR), and also highlights future strategies for developing novel anticancer agents.

Gold(I) Complexes Bearing Alkylated 1,3,5-Triaza-7-phosphaadamantane Ligands as Thermoresponsive Anticancer Agents in Human Colon Cells

Overheating can affect solubility or lipophilicity, among other properties, of some anticancer drugs. These temperature-dependent changes can improve efficiency and selectivity of the drugs, since they may affect their bioavailability, diffusion through cell membrane or activity. One recent approach to create thermosensitive molecules is the incorporation of fluorine atoms in the chemical structure, since fluor can tune some chemical properties such as binding affinity. Herein we report the anticancer effect of gold derivatives with phosphanes derived from 1,3,5-triaza-7-phosphaadamantane (PTA) with long hydrocarbon chains and the homologous fluorinated chains. Besides, we analysed the influence of temperature in the cytotoxic effect. The studied gold(I) complexes with phosphanes derived from PTA showed antiproliferative effect on human colon carcinoma cells (Caco-2/TC7 cell line), probably by inhibiting cellular TrxR causing a dysfunction in the intracellular redox state. In addition, the cell cycle was altered by the activation of p53, and the complexes produce apoptosis through mitochondrial depolarization and the consequent activation of caspase-3. Furthermore, the results suggest that this cytotoxic effect is enhanced by hyperthermia and the presence of polyfluorinated chains.

Core/Shell Gene Carriers with Different Lengths of PLGA Chains to Transfect Endothelial Cells

In order to improve the transfection efficiency and reduce the cytotoxicity of gene carriers, many strategies have been used to develop novel gene carriers. In this study, five complex micelles (MSP(2 k), MSP(4 k), MSP(6 k), MSP(8 k), and MSP(10 k)) were prepared from methoxy-poly(ethylene glycol)-b-poly(d,l-lactide-co-glycolide) (mPEG-b-PLGA) and sorbitol-poly(d,l-lactide-co-glycolide)-graft-PEI (sorbitol-PLGA-g-PEI, where the designed molecular weights of PLGA chains were 2 kDa, 4 kDa, 6 kDa, 8 kDa, and 10 kDa, respectively) copolymers by a self-assembly method, and the mass ratio of mPEG-b-PLGA to sorbitol-PLGA-g-PEI was 1/3. These complex micelles and their gene complexes had appropriate sizes and zeta potentials, and pEGFP-ZNF580 (pDNA) could be efficiently internalized into EA.hy926 cells by their gene complexes (MSP(2 k)/pDNA, MSP(4 k)/pDNA, MSP(6 k)/pDNA, MSP(8 k)/pDNA, and MSP(10 k)/pDNA). The MTT assay results demonstrated that the gene complexes had low cytotoxicity in vitro. When the hydrophobic PLGA chain increased above 6 kDa, the gene complexes showed higher performance than that prepared from short hydrophobic chains. Moreover, the relative ZNF580 protein expression levels in MSP(6 k)/pDNA, MSP(8 k)/pDNA, and MSP(10 k)/pDNA) groups were 79.6%, 71.2%, and 73%, respectively. These gene complexes could promote the transfection of endothelial cells, while providing important information and insight for the design of new and effective gene carriers to promote the proliferation and migration of endothelial cells.