Most cited article - PubMed ID 31348483
Mixed copper(ii)-phenanthroline complexes induce cell death of ovarian cancer cells by evoking the unfolded protein response
A series of more than 20 new amides of oleanolic acid and ursolic acid with selected aromatic amines were synthesized, and the structures of all compounds were analyzed and elucidated. Moreover, the compounds were subjected to the cytotoxicity assays in four cancer cell lines (CCRF-CEM, MCF7, HeLa, and G-361), using normal human fibroblasts (BJ) as reference cells for determining the toxicity of the investigated compounds. The 1,10-phenanthroline derivatives 4a, 4b, 5a, and 5b showed the highest cytotoxicity in all four cancer cell lines, but they were comparably toxic in human fibroblasts. The most promising results were achieved with 14a and 14b showing high cytotoxicity in the cancer cell lines and no toxicity in human fibroblasts. They were subjected to the investigation of the in vitro cell apoptosis, resulting in a confirmation of activation of apoptotic pathways in the CCRF-CEM cell line. The structure-activity relationships were documented by the cytotoxicity of 14a vs. 16a, and of 14b vs 16b, showing reverse effects in CCRF-CEM and MCF7 cancer cell lines. To investigate nanoassembly, initial screening of the target compounds by ultraviolet (UV) spectrometry was performed. Compounds 9b, 13b, 16b, and 17b, soluble both in methanol and in water, were selected for a more detailed investigation by transmission electron microscopy (TEM) microscopy and were found to form spherical nanoassemblies, frequently interconnected in small agglomerates and/or loose networks, while the other target compounds of this series showed no nanoassembling based on the TEM imaging. For each investigated compound, the nanoassemblies formed in methanol were substantially bigger than those formed in water.
- Publication type
- Journal Article MeSH
BACKGROUND: Lipopolysaccharide (LPS)-induced inflammation of lung tissues triggers irreversible alterations in the lung parenchyma, leading to fibrosis and pulmonary dysfunction. While the molecular and cellular responses of immune and connective tissue cells in the lungs are well characterized, the specific epithelial response remains unclear due to the lack of representative cell models. Recently, we introduced human embryonic stem cell-derived expandable lung epithelial (ELEP) cells as a novel model for studying lung injury and regeneration. METHODS: ELEPs were derived from the CCTL 14 human embryonic stem cell line through activin A-mediated endoderm specification, followed by further induction toward pulmonary epithelium using FGF2 and EGF. ELEPs exhibit a high proliferation rate and express key structural and molecular markers of alveolar progenitors, such as NKX2-1. The effects of Escherichia coli LPS serotype O55:B5 on the phenotype and molecular signaling of ELEPs were analyzed using viability and migration assays, mRNA and protein levels were determined by qRT-PCR, western blotting, and immunofluorescent microscopy. RESULTS: We demonstrated that purified LPS induces features of a hybrid epithelial-to-mesenchymal transition in pluripotent stem cell-derived ELEPs, triggers the unfolded protein response, and upregulates intracellular β-catenin level through retention of E-cadherin within the endoplasmic reticulum. CONCLUSIONS: Human embryonic stem cell-derived ELEPs provide a biologically relevant, non-cancerous lung cell model to investigate molecular responses to inflammatory stimuli and address epithelial plasticity. This approach offers novel insights into the fine molecular processes underlying lung injury and repair.
- Keywords
- Epithelial-to-mesenchymal transition, Expandable lung epithelium, Lipopolysaccharide, Unfolded protein response,
- MeSH
- Cell Line MeSH
- Antigens, CD metabolism MeSH
- Endoplasmic Reticulum * metabolism drug effects MeSH
- Epithelial-Mesenchymal Transition * drug effects MeSH
- Epithelial Cells * drug effects metabolism cytology MeSH
- Cadherins * metabolism MeSH
- Humans MeSH
- Human Embryonic Stem Cells * cytology MeSH
- Lipopolysaccharides * pharmacology MeSH
- Lung * cytology MeSH
- Thyroid Nuclear Factor 1 MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- Antigens, CD MeSH
- CDH1 protein, human MeSH Browser
- Cadherins * MeSH
- Lipopolysaccharides * MeSH
- NKX2-1 protein, human MeSH Browser
- Thyroid Nuclear Factor 1 MeSH
BACKGROUND: High-grade serous ovarian carcinoma (HGSOC) is the most common and aggressive subtype of epithelial ovarian carcinoma. It is primarily diagnosed at stage III or IV when the 5-year survival rate ranges between 20% and 40%. Here, we aimed to validate the hypothesis, based on HGSOC cell lines, that proposed the existence of two distinct groups of HGSOC cells with high and low oxidative phosphorylation (OXPHOS) metabolism, respectively, which are associated with their responses to glucose and glutamine withdrawal. METHODS: We isolated and cultivated primary cancer cell cultures from HGSOC and nontransformed ovarian fibroblasts from the surrounding ovarium of 45 HGSOC patients. We tested the metabolic flexibility of the primary cells, particularly in response to glucose and glutamine depletion, analyzed and modulated endoplasmic reticulum stress, and searched for indices of the existence of previously reported groups of HGSOC cells with high and low OXPHOS metabolism. RESULTS: The primary HGSOC cells did not form two groups with high and low OXPHOS that responded differently to glucose and glutamine availabilities in the cell culture medium. Instead, they exhibited a continuum of OXPHOS phenotypes. In most tumor cell isolates, the responses to glucose or glutamine withdrawal were mild and surprisingly correlated with those of nontransformed ovarian fibroblasts from the same patients. The growth of tumor-derived cells in the absence of glucose was positively correlated with the lipid trafficking regulator FABP4 and was negatively correlated with the expression levels of HK2 and HK1. The correlations between the expression of electron transport chain (ETC) proteins and the oxygen consumption rates or extracellular acidification rates were weak. ER stress markers were strongly expressed in all the analyzed tumors. ER stress was further potentiated by tunicamycin but not by the recently proposed ER stress inducers based on copper(II)-phenanthroline complexes. ER stress modulation increased autophagy in tumor cell isolates but not in nontransformed ovarian fibroblasts. CONCLUSIONS: Analysis of the metabolism of primary HGSOC cells rejects the previously proposed hypothesis that there are distinct groups of HGSOC cells with high and low OXPHOS metabolism that respond differently to glutamine or glucose withdrawal and are characterized by ETC protein levels.
Metabolic flux investigations of cells and tissue samples are a rapidly advancing tool in diverse research areas. Reliable methods of data normalization are crucial for an adequate interpretation of results and to avoid a misinterpretation of experiments and incorrect conclusions. The most common methods for metabolic flux data normalization are to cell number, DNA and protein. Data normalization may be affected by a variety of factors, such as density, healthy state, adherence efficiency, or proportional seeding of cells. The mussel-derived adhesive Cell-Tak is often used to immobilize poorly adherent cells. Here we demonstrate that this coating strongly affects the fluorescent detection of DNA leading to an incorrect and highly variable normalization of metabolic flux data. Protein assays are much less affected and cell counting can virtually completely remove the effect of the coating. Cell-Tak coating also affects cell shape in a cell line-specific manner and may change cellular metabolism. Based on these observations we recommend cell counting as a gold standard normalization method for Seahorse metabolic flux measurements with protein content as a reasonable alternative.
- MeSH
- DNA * MeSH
- Membrane Proteins * MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- Cell-Tak MeSH Browser
- DNA * MeSH
- Membrane Proteins * MeSH
Copper is an endogenous metal ion that has been studied to prepare a new antitumoral agent with less side-effects. Copper is involved as a cofactor in several enzymes, in ROS production, in the promotion of tumor progression, metastasis, and angiogenesis, and has been found at high levels in serum and tissues of several types of human cancers. Under these circumstances, two strategies are commonly followed in the development of novel anticancer Copper-based drugs: the sequestration of free Copper ions and the synthesis of Copper complexes that trigger cell death. The latter strategy has been followed in the last 40 years and many reviews have covered the anticancer properties of a broad spectrum of Copper complexes, showing that the activity of these compounds is often multi factored. In this work, we would like to focus on the anticancer properties of mixed Cu(II) complexes bearing substituted or unsubstituted 1,10-phenanthroline based ligands and different classes of inorganic and organic auxiliary ligands. For each metal complex, information regarding the tested cell lines and the mechanistic studies will be reported and discussed. The exerted action mechanisms were presented according to the auxiliary ligand/s, the metallic centers, and the increasing complexity of the compound structures.
- Keywords
- 1,10-phenanthroline, anticancer chemotherapy, cancer, cell stress response, chemoresistance, coordination compounds, copper,
- MeSH
- Phenanthrolines chemistry MeSH
- Inhibitory Concentration 50 MeSH
- Coordination Complexes chemical synthesis chemistry MeSH
- Humans MeSH
- Ligands MeSH
- Copper chemistry MeSH
- Molecular Structure MeSH
- Cell Line, Tumor MeSH
- Antineoplastic Agents chemical synthesis chemistry pharmacology MeSH
- Chemistry Techniques, Synthetic MeSH
- Cell Survival MeSH
- Dose-Response Relationship, Drug MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Review MeSH
- Names of Substances
- Phenanthrolines MeSH
- Coordination Complexes MeSH
- Ligands MeSH
- Copper MeSH
- Antineoplastic Agents MeSH