Systems biology based miRNA-mRNA expression pattern analysis of Emodin in breast cancer cell lines.

Breast cancer has been among the most prominent cancers with high mortality. Currently most of the offered therapeutics are toxic; hence, less toxic therapeutic intervention is required. Here, we studied the molecular mechanisms of the effect of a phytoestrogen Emodin on estrogen receptor positive MCF-7 and negative MDA-MB-231 cells by carrying out a comprehensive network assessment. Differentially expressed microRNAs along with their previously identified differentially expressed mRNAs were analyzed through microarrays by using integrative systems biology approach. For each cell line miRNA-target gene networks were built, gene ontology and pathway enrichment analyses were performed, enrichment maps were constructed and the potential key genes, miRNAs and miRNA-gene interactions were studied.

Identification of Potential Therapeutic Genes and Pathways in Phytoestrogen Emodin Treated Breast Cancer Cell Lines via Network Biology Approaches.

Phytoestrogens have been investigated for their potential anti-tumorigenic effects in various cancers including breast cancer. Emodin being a phytoestrogen shows anti-carcinogenic properties especially in estrogen receptor positive (ER+) breast cancers. The aim of this study is to identify the molecular mechanism and related biological pathways in both (ER+) MCF-7 and (ER-) MDA-MB-231 breast cancer cell lines upon Emodin treatment via microarray analysis in order to find out therapeutic biomarkers. In both cell lines, first differentially expressed genes were identified, then gene ontology and functional pathway enrichment analyses were performed. Genes regulated through multiple pathways were studied together with literature and a gene cluster was determined for each cell line. Further GeneMANIA and STRING databases were used to study the interactions within the related gene clusters. The results showed that, the genes which are related to cell cycle were significantly regulated in both cell lines. Also, Forkhead Box O1-related genes were found to be prominent in MCF-7 cells. In MDA-MB-231 cells, spindle attachment checkpoint mechanism-related genes were regulated, remarkably. As a result, novel gene regulations reported in this study in response to Emodin will give more information about its metabolism and antiproliferative effect, especially in ER + cells.

A pan-cancer transcriptomic study showing tumor specific alterations in central metabolism.

Recently, there has been a resurgence of interest in metabolic rewiring of tumors to identify clinically relevant genes. However, most of these studies have had either focused on individual tumors, or are too general, providing a broad outlook on overall changes. In this study, we have first curated an extensive list of genes encoding metabolic enzymes and metabolite transporters relevant to carbohydrate, fatty acid and amino acid oxidation and biosynthesis. Next, we have used publicly available transcriptomic data for 20 different tumor types from The Cancer Genome Atlas Network (TCGA) and focused on differential expression of these genes between tumor and adjacent normal tissue. Our study revealed major transcriptional alterations in genes that are involved in central metabolism. Most tumors exhibit upregulation in carbohydrate and amino acid transporters, increased glycolysis and pentose phosphate pathway, and decreased fatty acid and amino acid oxidation. On the other hand, the expression of genes of the tricarboxylic acid cycle, anaplerotic reactions and electron transport chain differed between tumors. Although most transcriptomic alterations were conserved across many tumor types suggesting the initiation of common regulatory programs, expression changes unique to specific tumors were also identified, which can provide gene expression fingerprints as potential biomarkers or drug targets. Our study also emphasizes the value of transcriptomic data in the deeper understanding of metabolic changes in diseases.

The potential application of gold-apoferritin nanocages conjugated with 2-amino-2-deoxy-glucose for imaging of breast cancer cells.

Development of biocompatible and multifunctional nanoprobes for tumor targeting, imaging, and therapy still remains a great challenge. Herein, gold nanoparticles (AuNPs) were synthesized in the cavity of horse spleen apoferritin protein (HoSAF) and protein surface was labeled with 2-amino-2-deoxy-glucose (2DG) as a cell surface glucose transport protein specific targeting probe to study the feasibility of its usage as a computer tomography (CT) contrast agent with tumor targeting capability through in vitro experiments. 2DG conjugated and gold-loaded apoferritin (Au-HoSAF-2DG) nanoparticles (NPs) showed selective targeting for human breast adenocarcinoma (MCF-7) cells when compared to normal breast (MCF-10A) cells. This AuNP-based imaging agent was found to be non-cytotoxic in a given concentration range with an apoptotic effect upon longer exposure times towards MCF-7 cells, while MCF-10A cells were affected less. This selective cell death would also be useful for further cancer treatments with the ability of X-ray attenuation in in vitro X-ray and computed tomography (CT) imaging.

In vitro effects of boric acid on human liver hepatoma cell line (HepG2) at the half-maximal inhibitory concentration.

BACKGROUND: Boron is a prominent part of the human diet and one of the essential trace elements for humans. Dietary boron is mostly transformed into boric acid within the body and has been associated with desirable health outcomes. Non-dietary resources of boron, such as boron-based drugs and occupational exposure, might lead to excessive boron levels in the blood and provoke health adversities. The liver might be particularly sensitive to boron intake with ample evidence suggesting a relation between boron and liver function, although the underlying molecular processes remain largely unknown. METHODS: In order to better understand boron-related metabolism and molecular mechanisms associated with a cytotoxic level of boric acid, the half-maximal inhibitory concentration (IC50) of boric acid for the hepatoma cell line (HepG2) was determined using the XTT assay. Cellular responses followed by boric acid treatment at this concentration were investigated using genotoxicity assays and microarray hybridizations. Enrichment analyses were carried out to find out over-represented biological processes using the list of differentially expressed genes identified within the gene expression analysis. RESULTS: DNA breaks were detected in HepG2 cells treated with 24 mM boric acid, the estimated IC50-level of boric acid. On the other hand, pleiotropic transcriptomic effects, including cell cycle arrest, DNA repair, and apoptosis as well as altered expression of Phase I and Phase II enzymes, amino acid metabolism, and lipid metabolism were discerned in microarray analyses. CONCLUSION: HepG2 cells treated with a growth-inhibitory concentration of boric acid for 24 h exhibited a senescence-like transcriptomic profile along with DNA damage. Further studies might help in understanding the concentration-dependent effects and mechanisms of boric acid.

Cellular uptake and apoptotic potential of rhenium labeled magnetic protein cages in MDA-MB-231 cells.

188Re-magnetoferritin nanoparticles (NPs) provide an attractive platform for localized radiation therapy due to their magnetic targeting capability while enhancing contrast in magnetic resonans imaging (MRI) signals. In this study, cellular uptake, in vitro cytotoxicity, apoptotic potential of a non-radioactive isotope of rhenium in the form of 187Re-magnetoferritin NPs were evaluated in both human normal mammary epithelial and breast metastatic adenocarcinoma cell lines. The results showed that, NP administration into the cells is through receptor mediated endocytosis and cancer cells displayed significantly higher uptake and cytotoxicity compared to normal cells. IC50 values of nanoparticles were calculated as 0.96 mg/mL for cancer and 1.73 mg/mL for normal cells. Annexin V/ Propidium Iodide (PI) staining also showed that, NPs induced higher apoptotic rates in cancer cells compared to normal cells. Gene expression analyses confirming the results showed that, pro-apoptotic PUMA and BAX genes were significantly up-regulated while anti-apoptotic BCL-2 and SURVIVIN genes were down-regulated in cancer cells compared to normal cells. Overall, these in vitro results suggest that, 187Re-magnetoferritin NPs have a promising potential for cancer therapy and can be used for imaging and diagnostic purposes for breast cancer at concentrations lower than 0.96 mg/mL. At concentrations above 1 mg/mL, NPs induce apoptosis which can also be used for cancer treatments.

2-Amino-2-deoxy-glucose conjugated cobalt ferrite magnetic nanoparticle (2DG-MNP) as a targeting agent for breast cancer cells.

In this study, 2-amino-2-deoxy-glucose (2DG) was conjugated to COOH modified cobalt ferrite magnetic nanoparticles (COOH-MNPs), which were designed to target tumor cells as a potential targetable drug/gene delivery agent for cancer treatment. According to our results, it is apparent that, 2DG labeled MNPs were internalized more efficiently than COOH-MNPs under the same conditions in all cell types (MDA-MB-231 and MCF-7 cancer and MCF-10A normal breast cells) (p<0.001). Moreover, the highest amount of uptake was observed in MDA-MB-231, followed by MCF-7 and normal MCF-10A cells for both MNPs. The apoptotic effects of 2DG-MNPs were further evaluated, and it was found that apoptosis was not induced at low concentrations of 2DG-MNPs in all cell types, whereas dramatic cell death was observed at higher concentrations. In addition, the gene expression levels of four drug-metabolizing enzymes, two Phase I (CYP1A1, CYP1B1) and two Phase II (GSTM3, GSTZ1) were also increased with the high concentrations of 2DG-MNPs.

Cellular uptake, genotoxicity and cytotoxicity of cobalt ferrite magnetic nanoparticles in human breast cells.

Magnetic nanoparticles (MNPs) have been increasingly used for many years as MRI agents and for gene delivery and hyperthermia therapy, although there have been conflicting results on their safety. In this study, cobalt ferrite magnetic nanoparticles (CoFe-MNPs) were prepared by the co-precipitation method and their surfaces were modified with silica by the sol-gel method. The particle and hydrodynamic sizes, morphology and crystal structure of the bare and silica-coated CoFe-MNPs were evaluated by transmission electron microscopy (TEM), dynamic light scattering (DLS), X-ray diffraction spectroscopy (XRD) and Fourier transform infrared spectroscopy (FTIR). The size of the bare CoFe-MNPs was in the range 8-20 nm and they were homogeneously coated with 3-4 nm silica shells. The bare and silica-coated CoFe-MNPs were agglomerated at physiological pH. However, the sizes of the agglomerates were below 200 nm both in water and complete medium. The cytotoxic and genotoxic potentials of the bare and silica-coated CoFe-MNPs were evaluated in a metastatic breast cancer cell line, MDA-MB-231, as well as a noncancerous mammary epithelial cell line, MCF-10A, by using XTT cytotoxicity, single-cell gel electrophoresis (comet), and cytokinesis-blocked (CB) micronucleus (CBMN) assays. Characterization studies with TEM, inductively coupled plasma optical emission spectroscopy (ICP-OES) and Prussian blue staining indicated that the CoFe-MNPs were internalized into the cells by energy-dependent endocytosis. The highest amount of uptake was observed in the cancer cells and the uptake of the silica-coated CoFe-MNPs was higher than that of the bare ones in both cell lines. The bare CoFe-MNPs showed higher levels of both cytotoxicity and genotoxicity than the silica-coated CoFe-MNPs. Moreover, the cancer cells seemed to be more susceptible to the CoFe-MNPs' toxicity compared to the noncancerous cells. There was a concentration and time-dependent increase in DNA damage and the micronucleus (MN) frequency, which was statistically significant starting with the lowest concentration of bare CoFe-MNPs (p < 0.05), while no significance was observed below the concentration of 250 µg mL-1 for the silica-coated MNPs. Also, the extent of both DNA damage and MN frequency was much higher in the cancer cells compared to the noncancerous cells. According to our results, the silica coating ameliorated both the cytotoxicity and genotoxicity as well the internalization of the CoFe-MNPs.