Induction of Apoptosis and Autophagy by Ternary Copper Complex Towards Breast Cancer Cells

Abstract

Background: Copper complex has been gaining much attention in anticancer research as targeted agent since cancer cells uptake more copper than non-cancerous cells. Our group has synthesised a ternary copper complex which is composed of 1,10-phenanthroline and tyrosine [Cu(phen)(L-tyr)Cl].3H20. These two payloads are designed to cleave DNA and inhibit protein degradation system (proteasome) concurrently in cancer cells, making this copper complex a dual-target compound. Objective: Current study was carried out to investigate the mode of cell death and role of autophagy induced by [Cu(phen)(L-tyr)Cl].3H20 in MCF-7 and MDA-MB-231 breast cancer cells. Methods: Growth inhibition of [Cu(phen)(L-tyr)Cl].3H20 towards MDA-MB-231 and human non-cancerous MCF10A breast cells was determined by MTT assay. Annexin-V-FITC/PI and cell cycle analysis were evaluated by flow cytometry. The expression of p53, Bax, caspase-9, caspase-7, caspase-3 and LC3 were determined using western blot analysis. The cells were then co-treated with hydroxychloroquine to ascertain the role of autophagy induced by [Cu(phen)(L-tyr)Cl].3H20. Results: [Cu(phen)(L-tyr)Cl].3H20 inhibited the growth of cancer cells dose-dependently with less toxicity towards MCF10A cells. Additionally, [Cu(phen)(L-tyr)Cl].3H20 induced apoptosis and cell cycle arrest towards MCF-7 and MDA-MB-231 breast cancer cells possibly via regulation of p53, Bax, caspase-9, caspase-3 and capase-7. The expression of LC3II was upregulated in both cancer cell lines upon treatment with [Cu(phen)(L-tyr) Cl].3H20, indicating the induction of autophagy. Co-treatment with autophagy inhibitor hydroxychloroquine significantly enhanced growth inhibition of both cell lines, suggesting that the autophagy induced by [Cu(phen)(L-tyr) Cl].3H20 in both breast cancer cells was promoting cell survival. Conclusion: [Cu(phen)(L-tyr)Cl].3H20 holds great potential to be developed for breast cancer treatment.

Cuproptosis: mechanisms and links with cancers

“…However, in studies on the mechanism of action of ES, the cytotoxic effect caused by ES-Cu was not eliminated by using 5 mM ROS inhibitor N-Acetylcysteine (NAC), and the cytotoxic effect was only partially eliminated by 10 mM NAC, so ROS-mediated cell death may not be the main mode of cell death caused by copper. The exact form of cell death caused by copper ions has been controversial, and in the past researchers have mostly regarded it as apoptosis [ 83 – 86 ], autophage [ 87 , 88 ] or ferroptosis [ 89 , 90 ], which can be proved by the evidence of cell viability assay, western blotting, flow cytometry and immunofluorescence staining. Until March 2022, Tsvetkov et al identified the mechanism of copper induced cell death, which was named cuproptosis, researches on the mechanism of copper induced cell death have reached a new milestone.…”

Selective Cytotoxicity of Novel Copper (II) Complex on Colon Cancer Cell Lines

“…The PI, which selectively stains cells with damaged membranes, is not able to stain the cells with intact cellular membranes. As a result, cells can be double stained with a DAPI, which stains all cells allowing to distinguish between dead and live cells [34]. It has been shown that ZU-3 increased cell death evidenced by pyknosis, cell shrinkage and reduction in cell density and PI-positivity in a dose-dependent manner, especially 2,5 µM and higher doses that is positively correlated with SRB assay (Fig.…”

Copper-instigated modulatory cell mortality mechanisms and progress in oncological treatment investigations

“…In addition, ternary copper complexes can competitively bind with DNA, as well as binding with nucleases, thus inhibiting their binding with plasmid, genes, and DNA within the nucleosome, and inducing tumor cell apoptosis by generating oxygen free radicals ( 117 ). For instance, the ternary copper (II) complex combined with 1-10-phenanthroline and L-tyrosine displayed active anticancer effects in HT-29 colon cancer cells ( 118 , 119 ). In Arikrishnan et al.’s experiment, the intracellular reactive oxygen species (ROS) was detected by DCFH-DA assay.…”