Finding New Molecular Targets of Two Copper(II)-Hydrazone Complexes on Triple-Negative Breast Cancer Cells Using Mass-Spectrometry-Based Quantitative Proteomics

Abstract

Breast cancer is the most common cancer in women, with a high incidence estimated to reach 2.3 million by 2030. Triple-Negative Breast Cancer (TNBC) is the greatest invasive class of breast cancer with a poor prognosis, due to the side-effects exerted by the chemotherapy used and the low effectivity of novel treatments. In this sense, copper compounds have shown to be potentially effective as antitumor agents, attracting increasing interest as alternatives to the usually employed platinum-derived drugs. Therefore, the aim of this work is to identify differentially expressed proteins in MDA-MB-231 cells exposed to two copper(II)-hydrazone complexes using label-free quantitative proteomics and functional bioinformatics strategies to identify the molecular mechanisms through which these copper complexes exert their antitumoral effect in TNBC cells. Both copper complexes increased proteins involved in endoplasmic reticulum stress and unfolded protein response, as well as the downregulation of proteins related to DNA replication and repair. One of the most relevant anticancer mechanisms of action found for CuHL1 and CuHL2 was the down-regulation of gain-of-function-mutant p53. Moreover, we found a novel and interesting effect for a copper metallodrug, which was the down-regulation of proteins related to lipid synthesis and metabolism that could lead to a beneficial decrease in lipid levels.

Recent Contributions of Mass Spectrometry-Based “Omics” in the Studies of Breast Cancer

“…Copper hydrazone complexes were used as a bait to detect proteome changes in TNBC-like BC cells where a gain-of-function p53 was downregulated and a favorable lipid synthetic pathway could be predicted with downregulations of some lipids. 128 Selective chemoresistant (for paclitaxel) proteins like TRAF6 were identified which were seen to regulate glycolysis and promote resistance. This regulator protein TRAF6 binds to PKM2 and thereby increases its activity; PKM2 was suggested as an actionable therapeutic target in TNBC treatment.…”

“…After applying specific search parameters, including the database and search algorithm, it imports MS data files into the platform and performs data preprocessing and quality control steps. It performs the database search by matching experimental MS/MS spectra against theoretical spectra and utilizes postprocessing tools for peptide and protein identification and filtering. ,,,,,,,,, Quantification methods based on the experimental design can be applied. Spectronaut is another software tool developed by Biognosys for targeted proteomics data analysis.…”

“…Hormonal stress related protein expressions were upregulated, while DNA replication and repair pathways were downregulated. Copper hydrazone complexes were used as a bait to detect proteome changes in TNBC-like BC cells where a gain-of-function p53 was downregulated and a favorable lipid synthetic pathway could be predicted with downregulations of some lipids . Selective chemoresistant (for paclitaxel) proteins like TRAF6 were identified which were seen to regulate glycolysis and promote resistance.…”

New copper(ii) and oxidovanadium(iv) complexes with a vitamin B6 Schiff base: mechanism of action and synergy studies on 2D and 3D human osteosarcoma cell models

“…8–19 The main mechanisms of action described for Cu-complexes involve reactive oxygen species (ROS) generation with consequent DNA damage 20–23 and proteasome and cancer stem cell inhibition. 24–26 However, only scarce Cu-complexes have been reported to show remarkable anticancer activity against OS cells. 27,28…”

Copper(ii) complexes of a furan-containing aroylhydrazonic ligand: syntheses, structural studies, solution chemistry and interaction with HSA

“…Being an essential element, a reduced toxicity is expected from its coordination compounds. 1 Moreover, since they usually follow a different mechanism of action, 2,3 therapies based on this micronutrient can help overcome tumor-resistance issues observed with the prolonged use of cisplatin and its derivatives. For these reasons, the interest in copper complexes as anticancer agents has dramatically increased in the last years, especially from 2010 on.…”