Stereospecific ligands and their complexes. Part XII. Synthesis, characterization and in vitro antiproliferative activity of platinum(IV) complexes with some O,O′-dialkyl esters of (S,S)-ethylenediamine-N,N′-di-2-propanoic acid against colon cancer (HCT-116) and breast cancer (MDA-MB-231) cell lines

Numerical modelling of WNT/β-catenin signal pathway in characterization of EMT of colorectal carcinoma cell lines after treatment with Pt(IV) complexes

BACKGROUND AND OBJECTIVE

Colorectal cancer (CRC) is at the top of the most common cancer types in the world, with significant mortality rates among both men and women. Deregulation of Wnt/β-catenin pathway and cell-cell junctions' components, acquisition of invasive phenotype, epithelial-mesenchymal transition (EMT) and invasion are important for development and progression of colorectal cancer. Numerical simulation presents method for estimation of the Wnt pathway via its individual components in cells, thus providing information about EMT, migratory and invasive potential. By using this numerical model, the effectiveness of treatment in EMT suppression can be assessed. Furthermore, the model can be adapted to ``every'' cell type, application time or duration of treatment can be also modified.

METHODS

We characterized colorectal cancer (CRC) cell lines (HCT-116, SW-480) from the aspect of EMT, via markers β-catenin and E-cadherin using numerical modeling. To confirm the numerical model, cells were treated with sublethal concentrations of platinum(IV) complexes and their ligands. We confirmed β-catenin regulated expression of mesenchymal markers: N-cadherin, Vimentin and MMP-9, and decreased E-cadherin expression. Treatment-induced changes were determined in the protein expression of tested markers and results showed cell-specific responses. Molecular docking was performed to investigate exact effects of treatments on E-cadherin and β-catenin in cell-cell junctions and individually in tested cells.

RESULTS

The application of the numerical model via β-catenin and E-cadherin (experimentally measured), is largely valid for the categorization of EMT progression in cells. This numerical modeling better characterizes cells with single cell migration, higher expression of mesenchymal markers, and advanced mesenchymal phenotype like HCT-116 cell line. The model was validated for the treatments and results show HCT-116 cells as more sensitive to applied compounds, among which ligands were more potent in reducing migration and invasiveness. Anti-migratory/invasive effects were due to increased E-cadherin, cytoplasmic β-catenin expression and suppressed mesenchymal markers. In silico methods showed higher affinity of tested chemicals towards free β-catenin, which is the key for regulation of migratory/invasive potential.

CONCLUSIONS

Our study shows that, no matter individual properties of cell lines and EMT degree, de novo formation of intercellular junctions stands in the basis of anti-migratory/invasive process.

Recent Advancements in the Development of Anti-Breast Cancer Synthetic Small Molecules

Among all cancer types, breast cancer (BC) still stands as one of the most serious diseases responsible for a large number of cancer-associated deaths among women worldwide, and diagnosed cases are increasing year by year worldwide. For a very long time, hormonal therapy, surgery, chemotherapy, and radiotherapy were used for breast cancer treatment. However, these treatment approaches are becoming progressively futile because of multidrug resistance and serious side effects. Consequently, there is a pressing demand to develop more efficient and safer agents that can fight breast cancer belligerence and inhibit cancer cell proliferation, invasion and metastasis. Currently, there is an avalanche of newly designed and synthesized molecular entities targeting multiple types of breast cancer. This review highlights several important synthesized compounds with promising anti-BC activity that are categorized according to their chemical structures.

Antiproliferative, antimigratory, and prooxidative potential of novel platinum(IV) complexes and resveratrol on breast cancer (MDA-MB-231) and choriocarcinoma (JEG-3) cell lines

Platinum(IV) complexes offer the potential to overcome cisplatin resistance of cancer cells, with possible improved selectivity. Resveratrol, a natural polyphenol with anticancer and antioxidant capacity, could limit the possible side effects of chemotherapeutics on healthy cells. This study investigates the effects of platinum(IV) complexes containing some esters of the ethylenediamine-N,N'-di-S,S-(2,2'-dibenzyl)acetate acid (H₂ -S,S-eddba), and resveratrol on proliferation, migration, and redox balance of breast cancer (MDA-MB-231), choriocarcinoma (JEG-3), and human lung fibroblast (MRC-5) cell line. According to IC₅₀ values, all complexes exhibited a significantly stronger antiproliferative effect on tested cell lines compared to cisplatin. Due to reduced adverse effects on MRC-5 cells, the complex containing ethyl-substituent (10 μM) was selected for further examination with resveratrol (25 μM) cotreatment. Resveratrol enhanced the survival of MRC-5 cells while diminished the viability of both used cancer cell lines when applied combined with selected complex. Furthermore, cotreatment of these two compounds decreased the migratory potential of tested cancer cell lines. The examined platinum(IV) complex was able to induce oxidative stress in all tested cell lines. Resveratrol proved to be efficient in protecting MRC-5 cells from complex-induced oxidative damage, while it significantly amplified antiproliferative, antimigratory, and prooxidative effects of platinum(IV) complex on both examined cancer cell lines. These findings may be valuable in elucidating the mechanism of action of platinum(IV) drugs, which should be further investigated.

Evaluation of Toxic Effects of Novel Platinum (IV) Complexes in Female Rat Liver: Potential Protective Role of Resveratrol

The use of cisplatin in chemotherapy may provoke a deteriorating impact in many vital organs, suggesting the need for more selective derivatives and effective protective cotreatments. This study assesses the effects of three novel Pt(IV) complexes containing ethyl-, propyl- and butyl-esters of the ethylenediamine-N, N'-di-S, S- (2,2'-dibenzyl) acetic acid on liver injury markers, redox parameters, and cell morphology of female rat liver tissue in comparison to cisplatin. In addition, the study evaluates the possible protective effects of resveratrol as well. The rats were divided into ten groups and were administered intraperitoneally with a single dose of cisplatin (7.5 mg/kg) or Pt(IV) complexes (10 mg/kg) and/or resveratrol (25 mg/kg). All treatments caused changes in body weight, food intake, and liver/bw ratio. Acute treatment with novel complexes decreased the levels of TB and TP while elevated the activity of ALT, AST, GGT, ALP which subsequently indicated on the liver damage. All three complexes significantly reduced the levels of LPO, O₂^.-, NO₂^- and activity of CAT, while increasing the activity of SOD, GSH-Px, GR, GST, and level of GSH, implying that these compounds could provoke redox balance disruption in liver cells. Moreover, according to the histopathological observations, the novel Pt(IV) complexes exerted stronger hepatotoxicity than cisplatin. Possible protective effects of resveratrol were not detected and even combined with examined compounds it abolished the activity of the antioxidative system of the liver cells causing more intense toxicity. Further investigation is required to elucidate the effects of Pt-based drugs and resveratrol in the estradiol-rich environment of female rats as well their influence on male rats' tissues.

Gold(III) Complexes: An Overview on Their Kinetics, Interactions With DNA/BSA, Cytotoxic Activity, and Computational Calculations

In the last few years, metallodrugs play a key role in the development of medicinal chemistry. The choice of metal ion, its oxidation state and stability, and the choice of inert and labile ligands are just some of the very important facts which must be considered before starting the synthesis of complexes with utilization in medicinal purpose. As a result, a lot of compounds of different transition metal ions found application for diagnostic and therapeutic purpose. Beside all, gold compounds have attracted particular attention. It is well-known that gold compounds could be used for the treatment of cancer, HIV, rheumatoid arthritis (chrysotherapy), and other diseases. This metal ion has unoccupied d-sublevels and possibility to form compounds with different oxidation states, from -1 to +5. However, gold(I) and gold(III) complexes are dominant in chemistry and medicine. Especially, gold(III) complexes are of great interest due to their structural similarity with cisplatin. Accordingly, this review summarizes the chemistry of some mononuclear and polynuclear gold(III) complexes. Special attention is given to gold(III) complexes with nitrogen-donor inert ligands (aliphatic or aromatic that have a possibility to stabilize complex) and their kinetic behavior toward different biologically relevant nucleophiles, mechanism of interaction with DNA/bovine serum albumin (BSA), cytotoxic activity, as well as computational calculations.

Current Development of Metal Complexes with Diamine Ligands as Potential Anticancer Agents

Background::

The discovery of cisplatin and the subsequent research revealed the importance of dinitrogen-containing moiety for the anticancer action of metal complexes. Moreover, certain diamine ligands alone display cytotoxicity that contributes to the overall activity of corresponding complexes.

Objective::

To summarize the current knowledge on the anticancer efficacy, selectivity, and the mechanisms of action of metal complexes with various types of diamine ligands.

Method::

The contribution of aliphatic acyclic, aliphatic cyclic, and aromatic diamine ligands to the anticancer activity and selectivity/toxicity of metal complexes with different metal ions were analyzed by comparison with organic ligand alone and/or conventional platinum-based chemotherapeutics.

Results::

The aliphatic acyclic diamine ligands are present mostly in complexes with platinum. Aliphatic cyclic diamines are part of Pt(II), Ru(II) and Au(III) complexes, while aromatic diamine ligands are found in Pt(II), Ru(II), Pd(II) and Ir(III) complexes. The type and oxidation state of metal ions greatly influences the cytotoxicity of metal complexes with aliphatic acyclic diamine ligands. Lipophilicity of organic ligands, dependent on alkyl-side chain length and structure, determines their cellular uptake, with edda and eddp/eddip ligands being most useful in this regard. Aliphatic cyclic diamine ligands improved the activity/toxicity ratio of oxaliplatin-type complexes. The complexes with aromatic diamine ligands remain unexplored regarding their anticancer mechanism. The investigated complexes mainly caused apoptotic or necrotic cell death.

Conclusion::

Metal complexes with diamine ligands are promising candidates for efficient and more selective alternatives to conventional platinum-based chemotherapeutics. Further research is required to reveal the chemico-physical properties and molecular mechanisms underlying their biological activity.

Synthesis, characterization, DFT study, DNA/BSA-binding affinity, and cytotoxicity of some dinuclear and trinuclear gold(III) complexes

In this study, we have synthesized a series of dinuclear and trinuclear gold(III) complexes of the general formula [Au₂(N-N)Cl₆] (1-3) for dinuclear and [Au₃(N-N)₂Cl₈]⁺ (4-6) for trinuclear compounds, respectively, in which N-N is a bidentate ligand (1,4-diaminobutane; 1,6-diaminohexane or 1,8-diaminooctane). These complexes were characterized by elemental analysis, molar conductivity, and spectroscopic techniques (IR, UV-Vis, ¹H NMR, ESI-MS). We performed DFT calculations to get insight into the geometry of the studies complexes. DNA-binding studies were performed by UV-Vis spectrophotometry and fluorescence spectroscopy. The results of competitive reactions between gold(III) complexes and ethidium bromide (EB) towards DNA have shown that selected complexes can displace EB from DNA-EB adduct. In addition, these experiments confirm that polynuclear gold(III) complexes interact with DNA covalently or via intercalation. Furthermore, high values of binding constants of gold(III) complexes towards bovine serum albumin (BSA) protein indicate good binding affinity. In addition, redox stability of complexes in the presence of DNA/BSA was confirmed by cyclic voltammetry. Results of the interactions between gold(III) complexes with DNA/BSA were discussed in reference to molecular docking data obtain by Molegro virtual docker. The cytotoxic activity of synthesized gold(III) complexes was evaluated on human breast cancer cell line (MDA-MB-231), human colorectal cancer cell line (HCT-116), and normal human lung fibroblast cell line (MRC-5). All complexes dose-dependently reduced cancer and normal cells viabilities, with significant cytotoxic effects (IC₅₀ < 25 μM) for trinuclear gold(III) complexes (4, 5) on HCT-116 cells.

Current research on anti-breast cancer synthetic compounds

Breast cancer (BC) is the most common cancer for females and its incidence tends to increase year by year.

Platinum Complexes with Edda (Ethylenediamine -N, N - Diacetate) Ligands as Potential Anticancer Agents

The design of platinum based drugs is not a new field of interest. Platinum complexes are widely used as anticancer agents and currently, approximately 30 platinum(II) and platinum(IV) entered into some of the phases of clinical trials. A special place in today’s research belongs to platinum complexes with diammine ligands. A large number of edda (ethylenediamine- N, N’-diacetate)-type ligands and their corresponding metal complexes has been successfully synthesized. This article summarizes recent progress in research on edda-type-platinum complexes. Some of these agents achieves better effect compared to the gold standard (cisplatin). It has been shown that there is a possible relationship between the length of the ligand ester group carbon chain and its cytotoxic effect. In most cases the longer the ester chain is the greater is the antitumor activity. Of particular interest are the noticeable effects of some new platinum compound with edda-type ligand on cell lines that are known to have a high level of cisplatin-resistance. Exanimate complexes appear to have a different mode of mechanism of action compared with cisplatin which includes apoptotic and necrotic cell death. There are indications that further investigations of these compounds may be very useful in overcoming the problems associated global cancer statistic.