Evaluation of anticancer activity in vitro of a stable copper(I) complex with phosphine-peptide conjugate.

[CuI(2,9-dimethyl-1,10-phenanthroline)P(p-OCH3-Ph)2CH2SarcosineGlycine] (1-MPSG), highly stable in physiological media phosphino copper(I) complex-is proposed herein as a viable alternative to anticancer platinum-based drugs. It is noteworthy that, 1-MPSG significantly and selectively reduced cell viability in a 3D spheroidal model of human lung adenocarcinoma (A549), in comparison with non-cancerous HaCaT cells. Confocal microscopy and an ICP-MS analysis showed that 1-MPSG effectively accumulates inside A549 cells with colocalization in mitochondria and nuclei. A precise cytometric analysis revealed a predominance of apoptosis over the other types of cell death. In the case of HaCaT cells, the overall cytotoxicity was significantly lower, indicating the selective activity of 1-MPSG towards cancer cells. Apoptosis also manifested itself in a decrease in mitochondrial membrane potential along with the activation of caspases-3/9. Moreover, the caspase inhibitor (Z-VAD-FMK) pretreatment led to decreased level of apoptosis (more pronouncedly in A549 cells than in non-cancerous HaCaT cells) and further validated the caspases dependence in 1-MPSG-induced apoptosis. Furthermore, the 1-MPSG complex presumably induces the changes in the cell cycle leading to G2/M phase arrest in a dose-dependent manner. It was also observed that the 1-MPSG mediated intracellular ROS alterations in A549 and HaCaT cells. These results, proved by fluorescence spectroscopy, and flow cytometry, suggest that investigated Cu(I) compound may trigger apoptosis also through ROS generation.

Copper(I) complexes with phosphines P(p-OCH3-Ph)2CH2OH and P(p-OCH3-Ph)2CH2SarGly. Synthesis, multimodal DNA interactions, and prooxidative and in vitro antiproliferative activity.

Phosphonium salt (p-OCH3-Ph)2P(CH2OH)2Cl (MPOHC), derived phosphine ligands without and with SarGly (Sarcosine-Glycine) peptide carrier P(p-OCH3-Ph)2CH2OH (MPOH) and P(p-OCH3-Ph)2CH2SarGly (MPSG), respectively, and two copper(I) complexes [Cu(I)(dmp)(MPOH)] (1-MPOH; dmp = (2,9-dimethyl-1,10-phenanthroline)) and [Cu(I)(dmp)(MPSG)] (1-MPSG) were synthesized. The resulting compounds were characterized by elemental analysis, 1D and 2D NMR and UV-Vis absorption spectroscopies, mass spectrometry, cyclic voltammetry and by X-ray diffraction analysis. Cytotoxicity of all compounds was evaluated in vitro against colon, lung, breast, pancreatic, prostate tumor cell lines, as well as towards non-tumor cell lines: lung, kidney and keratinocyte. Stable in biological medium in the presence of atmospheric oxygen, Cu(I) complexes exerted a cytotoxic effect higher than that elicited by cisplatin against tested cancer cell lines. The introduction of methoxy group onto the phenyl rings of the phosphine ligand coordinated to the copper(I) ion resulted in a relevant increase of cytotoxicity in the case of breast, pancreatic and prostate tumor cell lines in vitro. Attachment of a peptide carrier significantly increased the selectivity towards cancer cells. Fluorescence spectroscopic data (calf thymus DNA: CT-DNA) titration), together with analysis of DNA fragmentation (gel electrophoresis) and molecular docking provided evidence for the multimodal interaction of copper compounds with DNA and showed their unusual low genotoxicity. Additionally, copper complexes were able to generate reactive oxygen species as a result of redox processes, proved by fluorescence spectroscopy and cyclic voltamperometry.

Cu(II) Complexes with FomA Protein Fragments of Fusobacterium Nucleatum Increase Oxidative Stress and Malondialdehyde Level.

An explanation of carcinogenesis processes may certainly contribute to the prevention and development of novel methods for cancer treatment. In this paper, we considered the probable relationship between the presence of Fusobacterium nucleatum in the colon and its possible influence on the development of colorectal cancer. For this purpose, intracellular and/or extracellular generation of reactive oxygen species (ROS) by mouse colon carcinoma cells (CT26) was stimulated by two fragments of FomA adhesin from F. nucleatum and their complexes with copper(II): Cu(II)-Ac-KGHGNG-NH2 (1Cu) and Cu(II)-Ac-PTVHNE-NH2 (2Cu). Incubation of the cells with copper complexes was followed with ICP-MS technique. The overall generation of ROS was shown by means of fluorescence spectroscopy with two proper probes, whereas identification of ROS was achieved by the spin trapping technique and electron paramagnetic resonance measurements. As a result, an abundant production of the hydroxyl radicals, both inside and outside the cells, was observed upon the stimulation of the CT26 cells with the copper complexes. Clearly both compounds induced strong oxidation stress which triggered a radicals' cascade that finally resulted in the pronounced lipid peroxidation. The latter was evidenced with the measured level of malondialdehyde, a biomarker of the peroxidation process. By applying N-acetylcysteine antioxidant to the studied system, the free radical mechanism of the lipid peroxidation process was confirmed. Hypothetically this mechanism can lead to colon cell damage and further cancerogenesis processes.