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Magnetosomes are specialized organelles arranged in intracellular chains in magnetotactic bacteria. The superparamagnetic property of these magnetite crystals provides potential applications as contrast-enhancing agents for magnetic resonance imaging. In this study, we compared two different nanoparticles that are bacterial magnetosome and HSA-coated iron oxide nanoparticles for targeting breast cancer. Both magnetosomes and HSA-coated iron oxide nanoparticles were chemically conjugated to fluorescent-labeled anti-EGFR antibodies. Antibody-conjugated nanoparticles were able to bind the MDA-MB-231 cell line, as assessed by flow cytometry. To compare the cytotoxic effect of nanoparticles, MTT assay was used, and according to the results, HSA-coated iron oxide nanoparticles were less cytotoxic to breast cancer cells than magnetosomes. Magnetosomes were bound with higher rate to breast cancer cells than HSA-coated iron oxide nanoparticles. While 250 μg/ml of magnetosomes was bound 92 ± 0.2%, 250 μg/ml of HSA-coated iron oxide nanoparticles was bound with a rate of 65 ± 5%. In vivo efficiencies of these nanoparticles on breast cancer generated in nude mice were assessed by MRI imaging. Anti-EGFR-modified nanoparticles provide higher resolution images than unmodified nanoparticles. Also, magnetosome with anti-EGFR produced darker image of the tumor tissue in T2-weighted MRI than HSA-coated iron oxide nanoparticles with anti-EGFR. In vivo MR imaging in a mouse breast cancer model shows effective intratumoral distribution of both nanoparticles in the tumor tissue. However, magnetosome demonstrated higher distribution than HSA-coated iron oxide nanoparticles according to fluorescence microscopy evaluation. According to the results of in vitro and in vivo study results, magnetosomes are promising for targeting and therapy applications of the breast cancer cells.

The noninvasive, fast acquisition of quantitative phase maps using digital holographic microscopy (DHM) allows tracking of rapid cellular motility on transparent substrates. On two-dimensional surfaces in vitro, MDA-MB-231 cancer cells assume several morphologies related to the mode of migration and substrate stiffness, relevant to mechanisms of cancer invasiveness in vivo. The quantitative phase information from DHM may accurately classify adhesive cancer cell subpopulations with clinical relevance. To test this, cells from the invasive breast cancer MDA-MB-231 cell line were cultured on glass, tissue-culture treated polystyrene, and collagen hydrogels, and imaged with DHM followed by epifluorescence microscopy after staining F-actin and nuclei. Trends in cell phase parameters were tracked on the different substrates, during cell division, and during matrix adhesion, relating them to F-actin features. Support vector machine learning algorithms were trained and tested using parameters from holographic phase reconstructions and cell geometric features from conventional phase images, and used to distinguish between elongated and rounded cell morphologies. DHM was able to distinguish between elongated and rounded morphologies of MDA-MB-231 cells with 94% accuracy, compared to 83% accuracy using cell geometric features from conventional brightfield microscopy. This finding indicates the potential of DHM to detect and monitor cancer cell morphologies relevant to cell cycle phase status, substrate adhesion, and motility. © 2017 International Society for Advancement of Cytometry., (© 2017 International Society for Advancement of Cytometry.)

The chemokine receptor CXCR7 is regarded as a scavenger receptor for CXCL12, and induces numerous key steps in tumor growth and metastasis. However, the exact molecular mechanism of CXCR7 regulation in breast tumor angiogenesis remains unknown. In the present study, the function of CXCR7 in breast tumors was investigated in vitro and in vivo. The breast cancer MDA‑MB‑231 cell line was used. Pharmacological inhibition of CXCR7 by CCX771 reduced breast tumor invasion, adhesion and metastasis. Furthermore, CXCR7 was essential for the tube formation of HUVECs in vitro, and for blood vessel formation in a Matrigel plug assay in vivo. In addition, vascular endothelial growth factor expression was also decreased in CCX771‑treated MDA‑MB‑231 cells, indicating that CCX771 regulates tumor angiogenesis. The present results indicated that CXCR7 regulated breast cancer metastasis at multiple stages; additional understanding of CXCR7 in tumor environments may develop anti‑metastatic therapy.

Purpose: Breast cancer is one of the most commonly diagnosed types of cancer worldwide. This cancer is treated with various methods like mastectomy, chemotherapy, hormone therapy, and radiotherapy. Among them, targeted therapy, like microRNA (miRNA) replacement therapy, is considered a new approach to treating breast cancer. Methods: Data analysis from TCGA datasets were used to investigate the expression of hsamiR- 146a-5p in breast cancer. MTT assay was used to evaluate the viability of MDA-MB-231 cells after hsa-miR-146a-5p ectopic expression. A wound-healing assay was used to observe migration in the MDA-MB-231 cell line and the effect of the hsa-miR-146a-5p ectopic expression on migration. Finally, quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used as a method to determine the effect of the hsa-miR-146a-5p ectopic expression on the expression of CXCR4, β-catenin, MMP2, MMP9, and Vimentin genes known to be involved in invasion and migration of MDA-MB-231 cells. Results: Our results indicated that hsa-miR-146a-5p is not involved in apoptosis in the MDAMB- 231 cells, while it is highly effective in migration inhibition. MMP9, MMP2, CXCR4, and Vimentin expressions were suppressed by hsa-miR-146a-5p induction; however, it induced the expression of β-catenin. Conclusion: Some non-coding RNAs, such as hsa-miR-146a-5p, are effective in breast cancer targeted therapy. As cancer is a complicated disorder, therefore the combination of therapies might lead to novel therapeutic strategies. [ABSTRACT FROM AUTHOR]

This study explored the potential role of TG-interacting factor (TGIF) in migration, invasion and metastasis of the human breast cancer cell line MDA‑MB‑231. Western blot assay, immunohistochemistry and qRT-PCR assays were applied to detect the expression of protein and mRNA. Wound healing assay, Transwell invasion assay and tail vein metastatic assay were performed to assess the migration, invasion and metastasis of stable TGIF-silenced MDA‑MB‑231 cell line in vitro and in vivo. The significantly higher frequency of TGIF high-expression was observed in metastatic breast cancer (62.9%) compared to that in non-metastatic breast cancer (25.8%). Silencing TGIF suppressed migration and invasion of MDA‑MB‑231 cells in vitro and tumor metastasis in nude mouse models. The expression of Snail1, matrix metalloproteinase 2 (MMP2) and β-catenin was markedly decreased in the stable TGIF-silenced MDA‑MB‑231 cells compared with the control cells. Our results suggest that silencing TGIF suppressed the migration, invasion and metastasis of the human breast cancer cell line MDA‑MB‑231 using in vitro and in vivo experiments.

Background: In menopausal women, one of the critical risk factors for breast cancer is obesity/adiposity. It is evident from various studies that leptin, a 16 kDa protein hormone overproduced in obese people, plays the critical role in neovascularization and tumorigenesis in breast and other organs. However, the mechanisms by which obesity influences the breast carcinogenesis remained unclear. In this study, by analyzing different estrogen receptor-α (ER-α)-positive and ER-α-negative BC cell lines, we defined the role of CCN5 in the leptin-mediated regulation of growth and invasive capacity., Methods: We analyzed the effect of leptin on cell viability of ER-α-positive MCF-7 and ZR-75-1 cell lines and ER-α-negative MDA-MB-231 cell line. Additionally, we also determined the effect of leptin on the epithelial-mesenchymal transition (EMT) bio-markers, in vitro invasion and sphere-formation of MCF-7 and ZR-75-1 cell lines. To understand the mechanism, we determined the impact of leptin on CCN5 expression and the functional role of CCN5 in these cells by the treatment of human recombinant CCN5 protein(hrCCN5). Moreover, we also determined the role of JAK-STAT and AKT in the regulation of leptin-induced suppression of CCN5 in BC cells., Results: Present studies demonstrate that leptin can induce cell viability, EMT, sphere-forming ability and migration of MCF-7 and ZR-75-1 cell lines. Furthermore, these studies found that leptin suppresses the expression of CCN5 at the transcriptional level. Although the CCN5 suppression has no impact on the constitutive proliferation of MCF-7 and ZR-75-1 cells, it is critical for leptin-induced viability and necessary for EMT, induction of in vitro migration and sphere formation, as the hrCCN5 treatment significantly inhibits the leptin-induced viability, EMT, migration and sphere-forming ability of these cells. Mechanistically, CCN5-suppression by leptin is mediated via activating JAK/AKT/STAT-signaling pathways., Conclusions: These studies suggest that CCN5 serves as a gatekeeper for leptin-dependent growth and progression of luminal-type (ER-positive) BC cells. Leptin may thus need to destroy the CCN5-barrier to promote BC growth and progression via activating JAK/AKT/STAT signaling. Therefore, these observations suggest a therapeutic potency of CCN5 by restoration or treatment in obese-related luminal-type BC growth and progression.

BACKGROUND Quercetin, nature's most common flavonoid, possesses anticarcinogenic properties against various forms of cancer. The aim of this study was to investigate the effect of quercetin on breast cancer stem cells in the MDA-MB-231 cell line, and to elucidate the possible mechanisms for those effects. MATERIAL AND METHODS We evaluated breast cancer stem cell proliferation, clone generation, and mammosphere formation to determine the effect of quercetin treatment on breast cancer stem cells. RESULTS In our study, quercetin suppressed breast cancer stem cell proliferation, self-renewal, and invasiveness. It also lowered the expression levels of proteins related to tumorigenesis and cancer progression, such as aldehyde dehydrogenase 1A1, C-X-C chemokine receptor type 4, mucin 1, and epithelial cell adhesion molecules. CONCLUSIONS These results indicate that quercetin targets and destroys breast cancer stem cells, making it a potential novel drug in the fight against cancer.

According to the cancer stem cell (CSC) theory, a small subset of cells with stem cell-like characteristics is responsible for tumor initiation, progression, and recurrence. CD44 + /CD24 - phenotype is assumed to be one of the main characteristics of the breast CSCs. We developed an MDA-MB-231 cell line overexpressing cell surface HER2 antigen for the evaluation of targeting efficiency of anti-HER2 nanobody (Nb)-conjugated polyamidoamine (PAMAM) polyplexes. Apoptosis-inducing tBid gene under control of CXCR1 promoter was delivered by this nanoparticle. Cellular uptake study showed higher uptake of Nb-targeted PAMAM carriers compared to non-targeted nanoparticles after 6 h of incubation. Gene expression analysis showed a significant rise in the expression of tBid in both MDA-MB-231/HER2 + and MDA-MB-231 compared to the two other cell lines. The same effect was observed after transfection with Nb-conjugated polyplexes within MDA-MB-231/HER2 + cell line compared to non-conjugated PAMAM polyplexes. We confirmed the killing efficiency of the gene construct in both MDA-MB-231/HER2 + and MDA-MB-231 cell lines by caspase 3 activity assay. These findings suggest that imposing pre-entry and post-entry restrictions on tBid killer gene might be a promising approach to specifically target the breast CSCs.

Messenchymal to epithelial transition (MET) is a significant physiological phenomenon involved in embryogenesis and cancer. This study aims at investigating the mechanism of microRNA-20a (miR-20a) mediated regulation of mesenchymal to epithelial transition and identification of its direct target genes in breast cancer cell-line, MDA-MB-231. Reduced migratory and invasive property, altered cellular morphology along with reduced capability for attachment to basement membrane was acquired by over-expression of miR-20a in invasive MDA-MB-231 cell-line initially expressing low level of this micro-RNA, indicating direct correlation between abundance of miR-20a and metastatic property. The switch from mesenchymal to epithelial cells mediated by miR-20a involved post-transcriptional down-regulation of twist1, which in turn controls downstream epithelial markers like E-cadherin, claudin and mesenchymal markers like N-cadherin, fibronectin, the crucial players of mesenchymal to epithelial transition (MET). Furthermore, another key component, TGF-β and one of its receptors (TGFBR2) were found to be down-regulated by miR-20a. Additionally, reporter assay established that post-transcriptional down-regulation of TGFBR2 occurred through direct binding of miR-20a to its 3'UTR, thus abrogating the TGF-β signaling pathway resulting in inhibition of MET. Delineating the underlying molecular mechanism of miR-20a-mediated MET and defining the target genes will help us to introduce a miRNA-mediated effective therapeutic strategy against breast cancer., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Coumarins occurs naturally across plant kingdoms exhibits significant pharmacological properties and pharmacokinetic activity. The conventional, therapeutic agents are often associated with poor stability, absorption and increased side effects. Therefore, identification of a drug that has little or no-side effect on humans is consequential. Here, we investigated the antiproliferative activity of styrene substituted biscoumarin against various human breast cancer cell lines, such as MCF-7, (ER-) MDA-MB-231 and (AR+) MDA-MB-453. Styrene substituted biscoumarin induced cell death by apoptosis in MDA-MB-231 cell line was analyzed., Methods: Antiproliferative activity of Styrene substituted biscoumarin was performed by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Styrene substituted biscoumarin induced apoptosis was assessed by Hoechst staining, Annexin V-fluorescein isothiocyanate/propidium iodide (Annexin V-FITC/PI) staining and flow cytometric analysis. Migratory and proliferating characteristic of breast cancer cell line MDA-MB-231 was also analyzed by wound healing and colony formation assay. Furthermore, mRNA expression of BAX and BCL-2 were quantified using qRT-PCR and protein expression level analyzed by Western blot., Results: The inhibition concentration (IC 50 ) of styrene substituted biscoumarin was assayed against three breast cancer cell lines. The inhibition concentration (IC 50 ) value of styrene substituted biscoumarin toward MDA-MB-231, MDA-MB-453 and MCF-7 cell lines was 5.63, 7.30 and 10.84μg/ml respectively. Styrene substituted biscoumarin induced apoptosis was detected by Hoechst staining, DAPI/PI analysis and flow-cytometric analysis. The migration and proliferative efficiency of MDA-MB-231 cells were completely arrested upon styrene substituted biscoumarin treatment. Also, mRNA gene expression and protein expression of pro-apoptotic (BAX) and anti-apoptotic (BCL-2) genes were analyzed by qRT-PCR and western blot analysis upon styrene substituted biscoumarin treatment to MDA-MB-231 cells. Our results showed that styrene substituted biscoumarin downregulated BCL-2 gene expression and upregulated BAX gene expression to trigger apoptotic process., Conclusion: Styrene substituted biscoumarin could induce apoptosis through intrinsic mitochondrial pathway in breast cancer cell lines, particularly in MDA-MB-231. Our data suggest that styrene substituted biscoumarin may act as a potential chemotherapeutic agent against breast cancer., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Background: Propolis and its major constituent - caffeic acid phenethyl ester (CAPE) have good abilities on antitumor and anti-inflammation. However, little is known about the actions of propolis and CAPE on tumor in inflammatory microenvironment, and inflammatory responses play decisive roles at different stages of tumor development. To understand the effects and mechanisms of ethanol-extracted Chinese propolis (EECP) and its major constituent - CAPE in inflammation-stimulated tumor, we investigated their effects on Toll-like receptor 4 (TLR4) signaling pathway which plays a crucial role in breast cancer MDA-MB-231 cell line., Methods: 80% confluent breast cancer MDA-MB-231 cells were stimulated with 1 μg/mL lipopolysaccaride (LPS). Then the cells were divided for treatment by CAPE (25 μg/mL) and EECP (25, 50 and 100 μg/mL), respectively. Cell viability, nitric oxide (NO) production and cell migration were measured by sulforhodamine B assay, chemical method and scratch assay. The levels of TLR4, MyD88, IRAK4, TRIF, caspase 3, PARP, LC3B and p62 were investigated through western blotting. The expression of TLR4, LC3B and nuclear factor-κB p65 (NF-κB p65) were tested by immunofluorescence microscopy assay., Results: Treatment of different concentrations of EECP (25, 50 and 100 μg/mL) and CAPE (25 μg/mL) significantly inhibited LPS-stimulated MDA-MB-231 cell line proliferation, migration and NO production. Furthermore, EECP and CAPE activated caspase3 and PARP to induce cell apoptosis, and also upregulated LC3-II and decreased p62 level to induce autophagy during the process. TLR4 signaling pathway molecules such as TLR4, MyD88, IRAK4, TRIF and NF-κB p65 were all down-regulated after EECP and CAPE treatment in LPS-stimulated MDA-MB-231 cells., Conclusions: These findings indicated that EECP and its major constituent - CAPE inhibited breast cancer MDA-MB-231 cells proliferation in inflammatory microenvironment through activating apoptosis, autophagy and inhibiting TLR4 signaling pathway. EECP and CAPE may hold promising prospects in treating inflammation-induced tumor.

Proteasome activator subunit 3 (PSME3) plays a key role in breast cancer by regulating the cell cycle. However, its role in other pathogenesis-related features of breast cancer is unclear. In this study, we found that overexpression of PSME3 induced the epithelial-mesenchymal transition and contributed to induce the expression of cancer stem cell markers of the MDA-MB-231 cell line, thus increasing the migration, and invasion of the cells. Moreover, overexpression of PSME3 reduced the chemotaxis of CD8 + T cells and induced the apoptosis of T cells in vitro. Furthermore, PSME3 knockdown increased the number of CD8 + T cells in vivo and reduced the subcutaneous tumor growth rate. These findings revealed that PSME3 induces epithelial-mesenchymal transition with inducing the expression of CSC markers and influencing the tumor immune microenvironment in breast cancer., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Synthesis, inter-conversions and biological study of the dichloro bridged dicopper(II) compound [CuLCl] 2 (1) and its two mononuclear derivatives [CuLCl(H 2 O)]·H 2 O (2) and [CuLCl(py)] (3) (HL=2-(2-pyridylmethyleneamino)benzenesulfonic acid) are described. The dimeric compound 1 collapses into monomers 2 and 3 in the presence of coordinating solvents, water and pyridine, respectively, and 1 is regenerated upon simple stirring of 2 or 3 in methanol. The reactions of 1 with neutral (present study) and charged (earlier studies) ligands result in monomeric and multimeric compounds, respectively, attesting that it is a versatile dicopper(II) precursor. The anticancer activity of these copper complexes (1-3) was screened against lung (A-549) and breast (MDA-MB-231) human cancer cell lines. The IC 50 (half maximal inhibitory concentration) value for one (3) of the compounds suggests preferential cytotoxicity against breast cancer MDA-MB-231 cell line. Furthermore, the IC 50 value obtained for complex 3 is found to be almost two-fold times cytotoxic than the standard drug cisplatin. In addition, the underlying possible mechanism of its apoptosis-inducing efficacy in MDA-MB-231 cells has been rationalized by using flow cytometry (FACS) and Hoechst 33342/propidium iodide (PI) fluorescence staining. The stimulation of apoptotic induction for complex 3 has further been affirmed by reactive oxygen species (ROS) generation and mitochondrial aggregations studies., (Copyright © 2017 Elsevier Inc. All rights reserved.)

The gene expression profiles of MDA-MB-231 cell line of breast cancer and xenografts derived from this tumor in murine model were analyzed using GeneChip Human Transcriptome array 2.0 platform (Affymetrix). A more than 1000-fold increase in the MIR1973 gene expression was observed in the xenografts compared to the original cell line. Real-time reverse transcription PCR showed that the content of mature hsa-miR-1973 microRNA encoded by this gene was elevated in the xenografts by more than 300 times. According to microarray analysis, none of hsa-miR-1973 target genes available in the databases changed the expression in the cell line and xenografts. A possible role of hsa-miR-1973 is reduction of apoptosis in the tumor.

Inducible cyclooxgenase-2 (COX-2) is commonly overexpressed in breast tumors and is a target for cancer therapy. Here, we studied the effect of Celecoxib, a COX-2 inhibitor on two molecular breast cancer subtypes-MDA-MB-231 and SK-BR-3. Firstly, MDA-MB-231 and SK-BR-3 cells were treated with various concentration of Celecoxib for 24 and 48 h. Celecoxib-inhibition of NF-κB (p52 and p65) transcriptional activity and effect of Caspase 3 pathway were examined by western blotting. COX-2 mRNA was assessed by RT-PCR. Cell viability was evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazoliumbromide (MTT) assay. Both cell cycle profiles and apoptosis were analyzed using flow cytometry. We found that Celecoxib inhibited the proliferation of the MDA-MB-231 cell line in a dose-time dependent manner versus SK-BR-3 in a dose dependent manner only (p < 0.05). Celecoxib induced apoptosis of the MDA-MB-231 and SK-BR-3 cell lines in a dose-time dependent manner (p < 0.05) with more mean apoptotic cells in MDA-MB-231 than SK-BR-3. Significant cell-cycle arrest at the G1 phase in the MDA-MB-231 versus G2 phase in SK-BR-3 cell lines. NF-κB (p52 and p65) and COX-2 expressions were downregulated in a dose dependent manner, while Caspase 3 expression was upregulated in both cell lines. In this present study, our data indicated Celecoxib might affect each breast cancer subtype independently. Therefore, when using Celecoxib in treatment of breast cancer, it is imperative to consider the subtype of breast cancer on a molecular level., (Copyright © 2017. Published by Elsevier Inc.)

34 Xanthones were synthesized by microwave assisted technique. Their in vitro inhibition activities against five cell lines growth were evaluated. The SAR has been thoroughly discussed. 7-Bromo-1,3-dihydroxy-9H-xanthen-9-one (3-1) was confirmed as the most active agent against MDA-MB-231 cell line growth with an IC 50 of 0.46 ± 0.03 μM. Combination of 3-1 and 5,6-dimethylxanthone-4-acetic acid (DMXAA) showed the best synergistic effect. Apoptosis analysis indicated different contributions of early/late apoptosis and necrosis to cell death for both monomers and the combination. Western Blot implied that the combination regulated p53/MDM2 to a better healthy state. Furthermore, 3-1 and DMXAA arrested more cells on G2/M phase; while the combination arrested more cells on S phase. All the evidences support that the 3-1/DMXAA combination is a better anti-cancer therapy., (Copyright © 2017 Elsevier Masson SAS. All rights reserved.)

Magnetic iron oxide nanoparticles (MNPs) have been extensively utilized in a wide range of biomedical applications including magnetic hyperthermia agent. To improve the efficiency of the MNPs in therapeutic applications, in this study, we have synthesized CoFe 2 O 4 nanoparticles and its surface was further functionalized with meso-2,3-dimercaptosuccinic acid (DMSA). The anticancer agent, Doxorubucin (DOX) was conjugated with CoFe 2 O 4 @DMSA nanoparticle to evaluate the combined effects of thermotherapy and chemotherapy. The drug delivery efficiency of the DOX loaded CoFe 2 O 4 @DMSA nanoparticles were examined based on magnetically triggered delivery of DOX into the subcellular level of cancer cells by using MDA-MB-231 cell line. The amine part of the DOX molecules were effectively attached through an electrostatic interactions and/or hydrogen bonding interactions with the carboxylic acid groups of the DMSA functionalities present onto the surface of the CoFe 2 O 4 nanoparticles. The DOX loaded CoFe 2 O 4 @DMSA nanoparticles can effectively uptake with cancer cells via typical endocytosis process. After endocytosis, DOX release from CoFe 2 O 4 nanoparticles was triggered by intracellular endosomal/lysosomal acidic environments and the localized heat can be generated under an alternating magnetic field (AMF). In the presence of AMF, the released DOX molecules were accumulated with high concentrations into the subcellular level at a desired sites and exhibited a synergistic effect of an enhanced cell cytotoxicity by the combined effects of thermal-chemotherapy. Importantly, pH- and thermal-responsive Dox-loaded CoFe 2 O 4 nanoparticles induced significant cellular apoptosis more efficiently mediated by active mitochondrial membrane and ROS generation than the free Dox. Thus, the Dox-loaded CoFe 2 O 4 @DMSA nanoparticles can be used as a potential therapeutic agent in cancer therapy by combining the thermo-chemotherapy techniques., (Copyright © 2016. Published by Elsevier B.V.)

We recently showed that the anaplerotic enzyme pyruvate carboxylase (PC) is up-regulated in human breast cancer tissue and its expression is correlated with the late stages of breast cancer and tumor size [Phannasil et al., PloS One 10, e0129848, 2015]. In the current study we showed that PC enzyme activity is much higher in the highly invasive breast cancer cell line MDA-MB-231 than in less invasive breast cancer cell lines. We generated multiple stable PC knockdown cell lines from the MDA-MB-231 cell line and used mass spectrometry with 13 C 6 -glucose and 13 C 5 -glutamine to discern the pathways that use PC in support of cell growth. Cells with severe PC knockdown showed a marked reduction in viability and proliferation rates suggesting the perturbation of pathways that are involved in cancer invasiveness. Strong PC suppression lowered glucose incorporation into downstream metabolites of oxaloacetate, the product of the PC reaction, including malate, citrate and aspartate. Levels of pyruvate, lactate, the redox partner of pyruvate, and acetyl-CoA were also lower suggesting the impairment of mitochondrial pyruvate cycles. Serine, glycine and 5-carbon sugar levels and flux of glucose into fatty acids were decreased. ATP, ADP and NAD(H) levels were unchanged indicating that PC suppression did not significantly affect mitochondrial energy production. The data indicate that the major metabolic roles of PC in invasive breast cancer are primarily anaplerosis, pyruvate cycling and mitochondrial biosynthesis of precursors of cellular components required for breast cancer cell growth and replication., Competing Interests: The authors declare that they have no conflicts of interest with the contents of this article., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Thirteen new metabolites, including the polyoxygenated cyclohexene derivatives cleistodiendiol (1), cleistodienol B (3), cleistenechlorohydrins A (4) and B (5), cleistenediols A-F (6-11), cleistenonal (12), and the butenolide cleistanolate (13), 2,5-dihydroxybenzyl benzoate (cleistophenolide, 14), and eight known compounds (2, 15-21) were isolated from a MeOH extract of the leaves of Cleistochlamys kirkii. The purified metabolites were identified by NMR spectroscopic and mass spectrometric analyses, whereas the absolute configurations of compounds 1, 17, and 19 were established by single-crystal X-ray diffraction. The configuration of the exocyclic double bond of compound 2 was revised based on comparison of its NMR spectroscopic features and optical rotation to those of 1, for which the configuration was determined by X-ray diffraction. Observation of the co-occurrence of cyclohexenoids and heptenolides in C. kirkii is of biogenetic and chemotaxonomic significance. Some of the isolated compounds showed activity against Plasmodium falciparum (3D7, Dd2), with IC 50 values of 0.2-40 μM, and against HEK293 mammalian cells (IC 50 2.7-3.6 μM). While the crude extract was inactive at 100 μg/mL against the MDA-MB-231 triple-negative breast cancer cell line, some of its isolated constituents demonstrated cytotoxic activity with IC 50 values ranging from 0.03-8.2 μM. Compound 1 showed the most potent antiplasmodial (IC 50 0.2 μM) and cytotoxic (IC 50 0.03 μM, MDA-MB-231 cell line) activities. None of the compounds investigated exhibited translational inhibitory activity in vitro at 20 μM.

Background/aims: Epigenetics refers to modifications in gene activity and expression without alteration at the DNA sequence. Environment and diet could influence gene expression. Diet modifications may be meaningful in preventing and treating chronic diseases, cancer included. Dietary bioactive compounds, such as polyphenols (e.g., curcumin, resveratrol, or epigallocatechin gallate [EGCG]) or isothiocyanate (e.g., sulforaphane [SFN]), can regulate histone acetylation. The aim of this systematic review and meta-analysis was to evaluate the effect of SFN and EGCG on breast cancer (BC) cells cultured in vitro., Methods: Due to the enormous variability observed in study protocols and the innumerable genes involved, only studies analyzing the number of apoptotic cells in the MDA-MB-231 cell line were evaluated. The effect size (ES) was computed as the ratio of means., Results: We identified 7 studies, 4 regarding the effect of 10 µM SFN on MDA-MB-231 cells (ES = 4.59, 95% confidence interval 4.05-5.20) and 3 focusing on the impact of 20 µM EGCG (ES = 2.84, 95% confidence interval 2.60-3.10)., Conclusion: The findings suggest beneficial effects of dietary bioactive compounds such as SFN and EGCG and their effect on BC cells by restoring estrogen receptor gene expression, modulating epigenetic changes and events, and interfering with tumor growth rate. Publication bias limits the generalizability of the conclusions. High-quality studies are needed., (© 2017 S. Karger AG, Basel.)

Unlabelled: Multidrug resistance is the major obstacle for successful treatment of breast cancer, prompting the investigation of novel anticancer compounds., Purpose: In this study, we tested whether LQB-223, an 11a-N-Tosyl-5-deoxi-pterocarpan newly synthesized compound, could be effective toward breast cancer cells., Methods: Human breast cell lines MCF-7, MDA-MB-231, HB4a and MCF-7 Dox(R) were used as models for this study. Cell culture, MTT and clonogenic assay, flow cytometry and Western blotting were performed., Results: The LQB-223 decreased cell viability, inhibited colony formation and induced an expressive G2/M arrest in breast cancer cells. There was an induction in p53 and p21(Cip1) protein levels following treatment of wild-type p53 MCF-7 cells, which was not observed in the mutant p53 MDA-MB-231 cell line, providing evidence that the compound might act to modulate the cell cycle regardless of p53 status. In addition, LQB-223 resulted in decreased procaspase levels and increased annexin V staining, suggesting that the apoptotic cascade is also triggered. Importantly, LQB-223 treatment was shown to be less cytotoxic to non-neoplastic breast cells than docetaxel and doxorubicin. Strikingly, exposure of doxorubicin-resistant MCF-7-Dox(R) cells to LQB-223 resulted in suppression of cell viability and proliferation in levels comparable to MCF-7. Of note, MCF-7-Dox(R) cells have an elevated expression of the P-glycoprotein efflux pump when compared to MCF-7., Conclusion: Together, these results show that LQB-223 mediates cytotoxic effects in sensitive and resistant breast cancer cells, while presenting low toxicity to non-neoplastic cells. The new compound might represent a potential strategy to induce toxicity in breast cancer cells, especially chemoresistant cells.

Lipoxygenase (LOX) pathway has emerged to have a role in carcinogenesis. There is an evidence that both 12-LOX and 5-LOX have procarcinogenic role. We have previously reported the elevated level of serum 12-LOX in breast cancer patients. This study evaluated the serum level of 5-LOX in breast cancer patients and its in vitro inhibition assessment with peptide inhibitor YWCS. The level of 5-LOX was determined by surface plasmon resonance (SPR). The peptide inhibitor of 5-LOX was designed by molecular modeling and kinetic assay was performed by spectrophotometry. The siRNA mediated 5-LOX gene silencing was performed to investigate the effect on proliferation of MDA-MB-231, breast cancer cell line. The serum 5-LOX level in breast cancer (5.69±1.97ng/µl) was almost 2-fold elevated compared to control (3.53±1.0ng/µl) (P < 0.0001). The peptide YWCS had shown competitive inhibitory effects with IC50, 2.2 µM and dissociation constant (K D), 4.92×10(-8) M. The siRNA mediated knockdown of 5-LOX, resulted in the decreased gene expression for 5-LOX and increased cell death in MDA-MB-231 cell line and thereby play a key role in reducing tumor proliferation. Thus, it can be concluded that 5-LOX is one of the potential serum protein marker for breast cancer and a promising therapeutic target for the same., (© The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Long non-coding RNAs (lncRNAs) have been proven to serve a critical role in cancer development and progression. The aim of this study was to elucidate clinical significance of lncRNA MALAT1 expression in breast cancer (BC). A total of 78 BC patients treated with radical resection were enrolled in this study. Quantitative reverse transcription-polymerase chain reaction was used to detect MALAT1 expression in tissues and serum samples. The receiver operating characteristics (ROC) curve was constructed to describe diagnostic specificity and sensitivity. Lentivirus-mediated RNA interference was used to knockdown MALAT1 in the MDA-MB-231 cell line, and then cell proliferation and invasion were explored. Results showed that MALAT1 expression was significantly up-regulated in 85.9% (67/78) of cancerous tissues compared with normal counterparts (P<0.01). Further, an elevated MALAT1 expression in BC tissue was significantly associated with lymph metastasis (P=0.037) and adverse 5-year disease-free survival (mean 48.5 months vs 62.7 months, P=0.012). Suppression of lncRNA MALAT1 significantly inhibited BC cells proliferation, migration and invasion, induced apoptosis and cell cycle G1 arrest. In addition, serum MALAT1 levels in BC patients were much higher than levels in patients with benign breast disease (P<0.001), its diagnostic efficacy was satisfactory, area under the curve (AUC) was 0.833. In conclusion, MALAT1 upregulation plays an important rolein BC development, and serum MALAT1 level may be a potential tumor marker for BC diagnosis., (© 2016 by the Association of Clinical Scientists, Inc.)

In the present study, we analyzed the cell lysates of human tumour cell lines representing two major clinically different types of breast cancer. Our main goal was to show the differences between them on proteomic level. Gel electrophoresis followed by MALDI-TOF MS analysis was used for proteins determination. Exactly 98 proteins were unequivocally identified and 60 of them were expressed differentially between MDA-MB-231 and MCF-7 cell lines. Among the proteins reported here, some well-known breast cancer markers (e.g., annexin A1, annexin A2 and vimentin) were identified in the MDA-MB-231 cell line and thus we were able to distinguish both cell lines sufficiently.

MicroRNAs (miRNAs) play a key role in tumor metastasis based on their capacity to regulate the expression of tumor-related genes. Over-expression of key genes such as c-MYC and CTNNB1 (encoding β-catenin) in Wnt/β-catenin-dependent and ROCK1 in Wnt/β-catenin-independent signaling pathways (Rho/Rho-associated kinase (ROCK) signaling pathway) has already been identified as the hallmarks of many tumors, and their role in breast cancer has also been investigated and confirmed. miR-340 characterization as an onco-suppressor miRNA has been previously reported. However, the mechanism by which it inhibits metastasis has not been completely elucidated. Quantitative real-time PCR (qPCR), Western blot, and luciferase assays were used to confirm the effect of miR-340 on the 3'-untranslated region (UTR) of the target genes. Lentiviral particles containing miR-340 were also used to evaluate the effect of miR-340 restoration on cell proliferation, migration, and invasion in vitro in the invasive MDA-MB-231 cell line. By applying bioinformatic approaches for the prediction of miRNAs targeting 3'-UTRs of CTNNB1, c-MYC, and ROCK1, we found out that miR-340 could dramatically down-regulate metastasis by targeting Wnt signaling in breast cancer cells. In the current study, analyzing miR-340 by reverse transcription quantitative PCR (RT-qPCR) in MDA-MB-231 showed that it was remarkably down-regulated in the metastatic breast cancer cell line. We found that restoration of miR-340 in the invasive breast cancer cell line, MDA-MB-231, suppresses the expression of the target genes' messenger RNA (mRNA) and protein and, as a result, inhibits tumor cell invasion and metastasis. Our findings highlight the ability of bioinformatic approaches to find miRNAs targeting specific genes. By bioinformatic analysis, we confirmed the important role of miR-340 as a pivotal regulator of breast cancer metastasis in targeting previously validated (ROCK1) and potentially novel genes, i.e., (CTNNB1 and c-MYC).

Exosomes have been shown to transmit drug resistance through delivering miRNAs. We aimed to explore their roles in breast cancer. Three resistant sublines were established by exposing parental MDA-MB-231 cell line to docetaxel, epirubicin and vinorelbine, respectively. Preneoadjuvant chemotherapy biopsies and paired surgically-resected specimens embedded in paraffin from 23 breast cancer patients were collected. MiRNA expression profiles of the cell lines and their exosomes were evaluated using microarray. The result showed that most miRNAs in exosomes had a lower expression level than that in cells, however, some miRNAs expressed higher in exosomes than in cells, suggesting a number of miRNAs is concentrated in exosomes. Among the dysregulated miRNAs, 22 miRNAs were consistently up-regulated in exosomes and their cells of origin. We further found that 12 of the 22 miRNAs were significantly up-regulated after preneoadjuvant chemotherapy. Further study of the role of these 12 miRNAs in acquisition of drug resistance is needed to clarify their contribution to chemoresistance.

Background: A Disintegrin and Metalloprotease Domain 29 (ADAM29) is involved in many important physiological processes. Recent studies have demonstrated that ADAM29 is a susceptibility locus showing traits as a risk factor for breast cancer under genome-wide significance, however, the clinical relevance and cellular function of ADAM29 in breast cancer have not been reported., Materials and Methods: In this study, we assessed the expression levels of ADAM29 in a cohort of human breast cancer specimens. We also used MDA-MB-231 cells with differing ADAM29 expression and assessed the influence of ADAM29 and its mutations on the MDA-MB-231 cell line., Results: Increased transcript expression of ADAM29 was observed in breast cancer tissues compared to normal ones. The expression of ADAM29 and its mutations in different domains significantly influenced proliferation, migration and invasion of breast cancer cells in vitro., Conclusion: ADAM29 may represent a prognostic factor in human breast cancer, as well as a novel molecular candidate to be used as a therapeutic target., (Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.)

Caffeic acid phenethyl ester, derived from natural propolis, has been reported to have anti-cancer properties. Voltage-gated sodium channels are upregulated in many cancers where they promote metastatic cell behaviours, including invasiveness. We found that micromolar concentrations of caffeic acid phenethyl ester blocked voltage-gated sodium channel activity in several invasive cell lines from different cancers, including breast (MDA-MB-231 and MDA-MB-468), colon (SW620) and non-small cell lung cancer (H460). In the MDA-MB-231 cell line, which was adopted as a 'model', long-term (48 h) treatment with 18 μM caffeic acid phenethyl ester reduced the peak current density by 91% and shifted steady-state inactivation to more hyperpolarized potentials and slowed recovery from inactivation. The effects of long-term treatment were also dose-dependent, 1 μM caffeic acid phenethyl ester reducing current density by only 65%. The effects of caffeic acid phenethyl ester on metastatic cell behaviours were tested on the MDA-MB-231 cell line at a working concentration (1 μM) that did not affect proliferative activity. Lateral motility and Matrigel invasion were reduced by up to 14% and 51%, respectively. Co-treatment of caffeic acid phenethyl ester with tetrodotoxin suggested that the voltage-gated sodium channel inhibition played a significant intermediary role in these effects. We conclude, first, that caffeic acid phenethyl ester does possess anti-metastatic properties. Second, the voltage-gated sodium channels, commonly expressed in strongly metastatic cancers, are a novel target for caffeic acid phenethyl ester. Third, more generally, ion channel inhibition can be a significant mode of action of nutraceutical compounds., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Background: Reprimo (RPRM), a highly glycosylated protein, is a new downstream effector of p53-induced cell cycle arrest at the G2/M checkpoint, and a putative tumor suppressor gene frequently silenced via methylation of its promoter region in several malignances. The aim of this study was to characterize the epigenetic inactivation and its biological function in BC cell lines., Methods: The correlation between RPRM methylation and loss of mRNA expression was assessed in six breast cancer cell lines by methylation specific PCR (MSP), 5'-Aza-2'-deoxycytidine treatment and RT-PCR assays. MDA-MB-231 cells were chosen to investigate the phenotypic effect of RPRM in cell proliferation, cell cycle, cell death, cell migration and invasion., Results: In the cancer methylome system (CMS) (web-based system for visualizing and analyzing genome-wide methylation data of human cancers), the CpG island region of RPRM (1.1 kb) was hypermethylated in breast cancer compared to normal breast tissue; more interesting still was that ERα(+) tumors showed higher methylation intensity than ERα(-). Downregulation of RPRM mRNA by methylation was confirmed in MDA-MB-231 and BT-20 cell lines. In addition, overexpression of RPRM in MDA-MB-231 cells resulted in decreased rates of cell migration, wound healing and invasion in vitro. However, RPRM overexpression did not alter cell viability, phosphatidylserine (PS) translocation or G2/M cell cycle transition., Conclusion: Taken together, these data suggest that RPRM is involved in decreased cell migration and invasion in vitro, acting as a potential tumor suppressor gene in the MDA-MB-231 cell line.

A series of chalcone derivatives were designed, synthesized, and evaluated for their cytotoxic potential. These molecules have showed promising cytotoxic activity with IC50 values ranging from 5.24 to 63.12 μm. Among them, conjugates 16k, 16m and 16t showed significant antiproliferative activity with IC50 values ranging from 5.24 to 10.39 μm in MDA-MB-231 cell line. These compounds were further investigated for their effect on cell membrane blebbing, chromatin condensation, DNA fragmentation, Hoechst staining, annexin V, and cell cycle arrest (G2/M). The Western blot experiments revealed up regulation of pro-apoptotic Bax and downregulation of antiapoptotic Bcl-2. The studies also indicated reduction of mitochondrial membrane potential and increase in the levels of caspase-3 and caspase-7., (© 2015 John Wiley & Sons A/S.)

Objective: To investigate the influence of siRNA-mediated down-regulation of CD147 on growth, proliferation and movement of human breast cancer cell line MDA-MB-231., Methods: The protein expression of CD147, MMP-2 and TIMP-2 of the MDA-MB-231 cells were analyzed by ABC. Lentiviral expression vector of CD147 gene was constructed and transfected into MDA-MB-231 cells. RT-PCR and Western blot were used to detect the mRNA and protein level changes of CD147 genes to identify the optimal time point, followed by detection of changes of mRNA and protein expression of MMP-2 and TIMP-2 genes. CCK-8 reagent method and cell scratch test were used to detect the proliferation and migration change of MDA-MB-231 cells. The nude mouse model of breast cancer by hypodermic injection with MDA-MB-231 cells was established to document the effect of CD147 siRNA on the tumor transplants., Results: After transfection of lentiviral expression vector of CD147 gene, protein of CD147, MMP-2 and TIMP-2 were weakly or negative expressed, significantly weaker than those of control group (P < 0.01). After 72 hours of transfection, average down-regulation rate of CD147 and MMP-2 were 96.03% ± 0.84% and 96.03% ± 0.84%, respectively. Both CD147 mRNA and MMP-2 mRNA expression were down-regulated (P < 0.05), while TIMP-2 mRNA expression showed no significant deference (P > 0.05). No less than 2 days after transfection, cell growth of MDA-MB-231 cell line was found significantly inhibited (P < 0.05). After 24 hours of transection, average migration distance of MDA-MB-231 cell line and control group were (0.64 ± 0.12) mm and (4.69 ± 0.85) mm, respectively, which indicated a lower migrate speed. Down regulation of CD147 led to reduction of volume and mass of nude mouses. The growth of the carcinoma transplant was inhibited upon siRNA-mediated down-regulation of CD147 (P < 0.05), with an average tumor mass of (1.85 ± 0.98) g and both reduction of tumor size and tumor mass., Conclusions: CD147 may alter the MMP-2/TIMP-2 balance in MDA-MB-231 cells. CD147 gene silencing inhibits the proliferation and migration of MDA-MB-231 cells and the growth of carcinoma transplants in nude mice.

Docosahexaenoic acid (DHA; C22:6n-3) depresses mammary carcinoma proliferation and growth in cell culture and in animal models. The current study explored the role of interrupting bioenergetic pathways in BT-474 and MDA-MB-231 breast cancer cell lines representing respiratory and glycolytic phenotypes, respectively and comparing the impacts of DHA with a non-transformed cell line, MCF-10A. Metabolic investigation revealed that DHA supplementation significantly diminished the bioenergetic profile of the malignant cell lines in a dose-dependent manner. DHA enrichment also resulted in decreases in hypoxia-inducible factor (HIF-1α) total protein level and transcriptional activity in the malignant cell lines but not in the non-transformed cell line. Downstream targets of HIF-1α, including glucose transporter 1 (GLUT 1) and lactate dehydrogenase (LDH), were decreased by DHA treatment in the BT-474 cell line, as well as decreases in LDH protein level in the MDA-MB-231 cell line. Glucose uptake, total glucose oxidation, glycolytic metabolism, and lactate production were significantly decreased in response to DHA supplementation; thereby enhancing metabolic injury and decreasing oxidative metabolism. The DHA-induced metabolic changes led to a marked decrease of intracellular ATP levels by 50% in both cancer cell lines, which mediated phosphorylation of metabolic stress marker, AMPK, at Thr172. These findings show that DHA contributes to impaired cancer cell growth and survival by altering cancer cell metabolism, increasing metabolic stress and altering HIF-1α-associated metabolism, while not affecting non-transformed MCF-10A cells. This study provides rationale for enhancement of current cancer prevention models and current therapies by combining them with dietary sources, like DHA., (© 2014 Wiley Periodicals, Inc.)

Background: In this study, the effect of mango kernel extract in the induction of apoptosis of the breast cancer (MDA-MB-231) cell line was examined. This is an attempt to discover alternatives to current therapeutic regimes in the treatment of breast cancers., Methods: The pro-apoptotic markers, Bax, cytochrome c, caspases-. -8 and -9, and anti-apoptotic markers, Bcl-2, p53 and glutathione were determined in MDA-MB231 cells treated for 12 and 24 h with mango kernel extract., Results: The results showed that the extract produced a time- and dose-dependent increases in pro-apoptotic proteins and oxidative stress markers with a corresponding decrease in anti-apoptotic markers., Conclusions: Based on the findings, mango kernel extract modulates redox balance in MDA-MB-231 breast cancer cells with a tendency for apoptotic cell death. The changes observed in this study may collectively underlie the basis for the cell death induced in MDA-MB-231 breast cancer cells by mango kernel extract. Thus, mango kernel extract has potential to be developed into an antibreast cancer mixture, and hence these results are worth studying further.

The most common malignancy in women is breast cancer. Drug resistance in the treatment of cancer still remains a major clinical concern. Resistance to tamoxifen is seen in half of the recurrences in breast cancer. The anti-estrogen tamoxifen gains agonistic property by transactivating ERα. PAK1-mediated phosphorylation of serine 305 (S305) of ERα leads to resistance to tamoxifen. In our study, PAK1-induced suggestive tamoxifen resistance was designed. According to our hypothesis, phosphorylation of ERα-S305 by PAK1 may be reversed by PAK1 transcriptional inhibition by miR-221-3p due to miR-221-3p targeting the 3' UTR of PAK1. For this purpose, we used Real-time PCR (qRT-PCR) to measure the expression level of miR-221-3p in ER-positive breast cancer cell lines (ZR-75-1, MCF7) and breast epithelial cell line, hTERT-HME1, as control in the laboratory in our department. The increase in the expression of PAK1 depending on miR-221-3p may be related to ZR-75-1 cell line which has invasive characteristic but other two ER+ cancer cell lines, MCF7 and HCC1500, have milder cancer severity. miR-221-3p may have a role on regulation of PAK1 expression because miR-221-3p expression level decreases while PAK1 expression level increases in SKBR3 cell line. miR-221-3p and PAK1 expressions in MDA-MB-231 cell line are higher than that of hTERT-HME1 cell line. This may mean that miR-221-3p has no regulatory effect on of PAK1 expression in this cell line. According to these results, miR-221-3p may give crucial information about molecular mechanism of the disease upon PAK1 activity or different mechanisms with respect to histopathology and severity of breast cancer., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Monoamine oxidase-A (MAO-A) dysfunction has been historically associated with depression. Recently, depression as well as altered MAO-A expression have both been associated with a poor prognosis in cancers, although the mechanism involved remains ambiguous. For example, MAO-A mRNA is repressed across cancers, yet MAO-A protein and levels of serotonin, a substrate of MAO-A implicated in depression, are paradoxically increased in malignancies, including breast cancer. The effect of clorgyline (CLG), a selective inhibitor of MAO-A, on malignant behaviour, expression of transitional markers, and biochemical correlates was examined in two human breast carcinoma cell lines, i.e. the epithelial, oestrogen receptor (ER)-positive MCF-7 cell line and the post-EMT (mesenchymal), ER-negative MDA-MB-231 cell line. CLG exerted little effect on malignant behaviour in MCF-7 cells, but inhibited proliferation and anchorage-independent growth, and increased invasiveness and active migration of MDA-MB-231 cells. CLG induced the expression of the mesenchymal marker vimentin in MCF-7 cells, but not in MDA-MB-231 cells. In contrast, CLG induced the epithelial protein marker E-cadherin in both cell lines, with a more robust effect in MDA-MB-231 cells (where a nuclear E-cadherin signal was also detected). This effect appears to be independent of any canonical Snai1-mediated regulation of E-cadherin mRNA expression. CLG interfered with the β-catenin/[phospho]GSK-3β complex as well as the E-cadherin/β-catenin complex in both cell lines cells, but, again, the effect was more robust in MDA-MB-231 cells. Parallel studies revealed a general lack of effect of CLG on the ER-negative, epithelial Au565 breast cancer cell line. Thus, any effect of CLG on metastatic behaviours appears to rely on the cell's EMT status rather than on the cell's ER status. These data suggest that inactivation of MAO-A triggers a mesenchymal-to-epithelial transition in MDA-MB-231 cells via a non-canonical mechanism. This potentially implicates an MAO-A-sensitive step in advanced breast cancer and should be borne in mind when considering pharmacological treatment options for co-morbid depression in breast cancer patients., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Evidences indicate that tumor development and progression towards a malignant phenotype depend not only on cancer cells themselves, but are also deeply influenced by tumor stroma reactivity. The present study uses mesenchymal stem cells from normal human uterine cervix (hUCESCs), isolated by the minimally invasive method of routine Pap cervical smear, to study their effect on the three main cell types in a tumor: cancer cells, fibroblasts and macrophages. Administration of hUCESCs-conditioned medium (CM) to a highly invasive breast cancer MDA-MB-231 cell line and to human breast tumors with high cell proliferation rates had the effect of reducing cell proliferation, modifying the cell cycle, inducing apoptosis, and decreasing invasion. In a xenograft mouse tumor model, hUCESCs-CM reduced tumor growth and increased overall survival. In cancer-associated fibroblasts, administration of hUCESCs-CM resulted in reduced cell proliferation, greater apoptosis and decreased invasion. In addition, hUCESCs-CM inhibited and reverted macrophage differentiation. The analysis of hUCESCs-CM (fresh and lyophilized) suggests that a complex paracrine signaling network could be implicated in the anti-tumor potential of hUCESCs. In light of their anti-tumor potential, the easy cell isolation method, and the fact that lyophilization of their CM conserves original properties make hUCESCs good candidates for experimental or clinical applications in anticancer therapy.

Breast cancer already taken the first place of incidence in Chinese female cancer patients. TRPM8 is found to be over-expressed in breast cancer, but whether it promotes breast cancer aggressiveness remains unknown. In our study, TRPM8 was identified highly expressing in all the tested breast cancer cell lines including MCF-7, T47D, MDA-MB-231, BT549, SKBR3 and ZR-75-30, while it just could be detected in MCF-10A, the normal breast epithelial cell. Then four pairs of clinical samples were analyzed using Western blotting and the result showed that TRPM8 expression is higher in tumor tissues than in adjacent nontumor tissues. Subsequently, we established TRPM8 high-expressing MCF-7 cell line and TRPM8 knockout MDA-MB-231 cell line to explore expression status of cancer-related proteins. The Western blotting and immunofluorescence analysis outcomes demonstrated that TRPM8 might influence cancer cell metastasis by regulating the EMT phenotype via activating AKT/GSK-3β pathway, and the hypothesis had been supported by cell function tests. All the results demonstrated that TRPM8 significantly up-expressed in breast cancer cells and promoted their metastasis by regulating EMT via activating AKT/GSK-3β pathway, indicating TRPM8 gets the prospects of to be developed as medication or diagnostic indicator to be applied in clinical work.

Unlabelled: Current radiologic methods for diagnosing breast cancer detect specific morphologic features of solid tumors or any associated calcium deposits. These deposits originate from an early molecular microcalcification process of 2 types: type 1 is calcium oxylate and type II is carbonated calcium hydroxyapatite. Type I microcalcifications are associated mainly with benign tumors, whereas type II microcalcifications are produced internally by malignant cells. No current noninvasive in vivo techniques are available for detecting intratumoral microcalcifications. Such a technique would have a significant impact on breast cancer diagnosis and prognosis in preclinical and clinical settings. (18)F-NaF PET has been used solely for bone imaging by targeting the bone hydroxyapatite. In this work, we provide preliminary evidence that (18)F-NaF PET imaging can be used to detect breast cancer by targeting the hydroxyapatite lattice within the tumor microenvironment with high specificity and soft-tissue contrast-to-background ratio while delineating tumors from inflammation., Methods: Mice were injected with approximately 10(6) MDA-MB-231 cells subcutaneously and imaged with (18)F-NaF PET/CT in a 120-min dynamic sequence when the tumors reached a size of 200-400 mm(3). Regions of interest were drawn around the tumor, muscle, and bone. The concentrations of radiotracer within those regions of interest were compared with one another. For comparison to inflammation, rats with inflamed paws were subjected to (18)F-NaF PET imaging., Results: Tumor uptake of (18)F(-) was significantly higher (P < 0.05) than muscle uptake, with the tumor-to-muscle ratio being about 3.5. The presence of type II microcalcification in the MDA-MB-231 cell line was confirmed histologically using alizarin red S and von Kossa staining as well as Raman microspectroscopy. No uptake of (18)F(-) was observed in the inflamed tissue of the rats. Lack of hydroxyapatite in the inflamed tissue was verified histologically., Conclusion: This study provides preliminary evidence suggesting that specific targeting with (18)F(-) of hydroxyapatite within the tumor microenvironment may be able to distinguish between inflammation and cancer., (© 2014 by the Society of Nuclear Medicine and Molecular Imaging, Inc.)

To date, plants have been the major source of anticancer drugs. Boldine is a natural alkaloid commonly found in the leaves and bark of Peumus boldus. In this study, we found that boldine potently inhibited the viability of the human invasive breast cancer cell lines, MDA-MB-231 (48-hour IC₅₀ 46.5±3.1 μg/mL) and MDA-MB-468 (48-hour IC₅₀ 50.8±2.7 μg/mL). Boldine had a cytotoxic effect and induced apoptosis in breast cancer cells as indicated by a higher amount of lactate dehydrogenase released, membrane permeability, and DNA fragmentation. In addition, we demonstrated that boldine induced cell cycle arrest at G2/M phase. The anticancer mechanism is associated with disruption of the mitochondrial membrane potential and release of cytochrome c in MDA-MB-231. Boldine selectively induced activation of caspase-9 and caspase-3/7, but not caspase-8. We also found that boldine could inhibit nuclear factor kappa B activation, a key molecule in tumor progression and metastasis. In addition, protein array and Western blotting analysis showed that treatment with boldine resulted in downregulation of Bcl-2 and heat shock protein 70 and upregulation of Bax in the MDA-MB-231 cell line. An acute toxicity study in rats revealed that boldine at a dose of 100 mg/kg body weight was well tolerated. Moreover, intraperitoneal injection of boldine (50 or 100 mg/kg) significantly reduced tumor size in an animal model of breast cancer. Our results suggest that boldine is a potentially useful agent for the treatment of breast cancer.

Diversin was recently reported to play roles in Wnt and JNK pathways. However, the expression pattern and biological roles of diversin in human breast cancer have not been reported. In the present study, we found that diversin was overexpressed in breast cancer specimens by immunohistochemistry and western blot. Significant association was observed between diversin overexpression and TNM stage (p = 0.0036), nodal metastasis (p = 0.0033), negative estrogen receptor expression (p = 0.0012) and triple-negative status (p = 0.0017). Furthermore, colony formation assay and matrigel invasion assay showed that knockdown of diversin expression in MDA-MB-231 cell line with high endogenous expression decreased cell proliferation and cell invasion. Transfection of diversin plasmid in MCF-7 cell line increased cell proliferation and invasion. Further analysis showed that diversin depletion downregulated JNK phosphorylation while its overexpression upregulated JNK phosphorylation. In conclusion, our study demonstrated that diversin was overexpressed in human breast cancers. Diversin could contribute to breast cancer cell proliferation and invasion.

Successful management of metastatic breast cancer still needs better chemotherapeutic approaches. The combination of fenretinide (4-HPR), a synthetic retinoid inducing apoptosis by ROS generation, and TRAIL, a cell death ligand inducing caspase-dependent apoptosis, might result in more powerful cytotoxic activity. We therefore investigated the cytotoxic activity and resulting cell death mode of this combination in MDA-MB-231 cell line as a representative of metastatic state. Cytotoxicity was assessed by the ATP viability assay while the mode of cell death was determined both morphologically using fluorescence microscopy and biochemically using Western blotting and ELISA. The combination resulted in an additive cytotoxic effect at the doses used. Fragmented and/or pyknotic nuclei, which is a feature of apoptosis, were observed after treatment with fenretinide or TRAIL. However, the combinatorial treatment further increased apoptotic figures. Confirming apoptosis, active caspase-3 and cleaved PARP were increased by fenretinide or TRAIL in both western blotting and ELISA. Again, apoptosis was further increased by the combination. The combination warrants further studies due to its superior cytotoxic activity in the metastatic setting of breast cancer., (Copyright © 2014 Elsevier Masson SAS. All rights reserved.)

The miRNAs regulate cell functions by inhibiting expression of proteins. Research on miRNAs had usually focused on identifying targets by base pairing between miRNAs and their targets. Instead of identifying targets, this paper proposed an innovative approach, namely impact significance analysis, to study the correlation between mature sequence, expression across patient samples or time and global function on cell cycle signaling of miRNAs. With three distinct types of data: The Cancer Genome Atlas miRNA expression data for 354 human breast cancer specimens, microarray of 266 miRNAs in mouse Embryonic Stem cells (ESCs), and Reverse Phase Protein Array (RPPA) transfected by 776 miRNAs in MDA-MB-231 cell line, we linked the expression and function of miRNAs by their mature sequence and discovered systematically that the similarity of miRNA expression enhances the similarity of miRNA function, which indicates the miRNA expression can be used as a supplementary factor to predict miRNA function. The results also show that both seed region and 3' portion are associated with miRNA expression levels across human breast cancer specimens and in ESCs; miRNAs with similar seed tend to have similar 3' portion. And we discussed that the impact of 3' portion, including nucleotides 13-16, is not significant for miRNA function. These results provide novel insights to understand the correlation between miRNA sequence, expression and function. They can be applied to improve the prediction algorithm and the impact significance analysis can also be implemented to similar analysis for other small RNAs such as siRNAs.

Plasma membrane-localized vascular endothelial growth factor receptors (VEGFR) play a critical role in transducing VEGF signaling toward pro and antiangiogenic outcomes and quantitative characterization of these receptors is critical toward identifying biomarkers for antiangiogenic therapies, understanding mechanisms of action of antiangiogenic drugs, and advancing predictive computational models. While in vitro analysis of cell surface-VEGFRs has been performed, little is known about the levels of cell surface-VEGFR on tumor cells. Therefore, we inoculate nude mice with the human triple-negative breast cancer, MDA-MB-231, cell line; isolate human tumor cells and mouse tumor endothelial cells from xenografts; and quantitatively characterize the VEGFR localization on these cells. We observe 15,000 surface-VEGFR1/tumor endothelial cell versus 8200 surface-VEGFR1/tumor endothelial cell at 3 and 6 weeks of tumor growth, respectively; and we quantify 1200-1700 surface-VEGFR2/tumor endothelial cell. The tumor cell levels of VEGFR1 and VEGFR2 are relatively constant between 3 and 6 weeks: 2000-2200 surface-VEGFR1/tumor cell and ~1000 surface-VEGFR2/tumor cell. Cell-by-cell analysis provides additional insight into tumor heterogeneity by identifying four cellular subpopulations based on size and levels of cell membrane-localized VEGFR. Furthermore, when these ex vivo data are compared to in vitro data, we observe little to no VEGFRs on MDA-MB-231 cells, and the MDA-MB-231 VEGFR surface levels are not regulated by a saturating dose of VEGF. Overall, the quantification of these dissimilarities for the first time in tumor provides insight into the balance of modulatory (VEGFR1) and proangiogenic (VEGFR2) receptors., (© 2014 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)

Objective: To prepare a recombinant lentiviral carring human lysosome-associated membrane protein type 2A (LAMP2A) gene shRNA, establish MDA-MB-231 cell line with a low expression of LAMP2A and observe the change in cell resistance to paclitaxel., Methods: Four shRNAs were designed according to the sequencing analysis of LAMP2A mRNA. The pGLV-EGFP-shRNA lentiviral vector was established by gene recombination technology and was confirmed by DNA sequencing. The lentiviral vector and the packaging vector were used to cotransfect the HEK293T cells to obtain the lentivirus against LAMP2A mRNA, and the titer of the virus was determined. The constructed shRNA lentivirus was applied to infect human breast cancer cell line MDA-MB-231, and then the cells were screened with puromycin for two weeks. The inhibitive efficacy of the shRNA on the LAMP2A protein was determined by Western blotting. After the breast cancer cell line with a low expression of LAMP2A was treated with three different concentrations of paclitaxel (1, 10, 100 nmol/L), MTT assay was performed to observe the difference in the proliferation ability between the control group and the low LAMP2A expression groups., Results: DNA sequencing revealed that the recombinant lentiviral plasmid was correctly constructed with the virus titer reaching 2×10(8); TU/mL. The LAMP2A protein expression in the obtained breast cancer cell line dropped drastically. After the treatment with paclitaxel at 10 and 100 nmol/L respectively, the drug resistance of cells with a low expression of LAMP2A was notably weaker than that of the control group (P<0.05)., Conclusion: The recombinant shRNA lentiviral vector against human LAMP2A gene was successfully constructed, and the breast cancer cell line MDA-MB-231 transfected with it stably expressed a low level of LAMP2A. It was proved that the down-regulation of LAMP2A could reduce the resistance of breast cancer cells to paclitaxel.

The interplay between oxidative stress and autophagy is critical for determining the fate of cancer cells exposed to redox-active and cytotoxic chemotherapeutic agents. Mitoquinone (MitoQ), a mitochondrially-targeted redox-active ubiquinone conjugate, selectively kills breast cancer cells over healthy mammary epithelial cells. We reported previously that MitoQ, although a derivative of the antioxidant ubiquinone, can generate excess ROS and trigger the Keap1-Nrf2 antioxidant response in the MDA-MB-231 cell line. Following MitoQ treatment, a greater number of cells underwent autophagy than apoptosis. However, the relationship between MitoQ-induced oxidative stress and autophagy as a primary cellular response was unclear. In this report, we demonstrate that MitoQ induces autophagy related gene 7 (Atg7)-dependent, yet Beclin-1-independent, autophagy marked by an increase in LC3-II. Both the ATG7-deficient human MDA-MB-231 cells and Atg7-knockout mouse embryonic fibroblasts exhibited lower levels of autophagy following MitoQ treatment than their respective wild-type counterparts. Increased apoptosis was confirmed in these autophagy-deficient isogenic cell line pairs, indicating that autophagy was attempted for survival in wild type cell lines. Furthermore, we observed higher levels of ROS in Atg7-deficient cells, as measured by hydroethidine oxidation. In Atg7-deficient cells, redox-sensitive Keap1 degradation was decreased, suggesting autophagy- and Atg7-dependent degradation of Keap1. Conversely, downregulation of Keap1 decreased autophagy levels, increased Nrf2 activation, upregulated cytoprotective antioxidant gene expression, and caused accumulation of p62, suggesting a feedback loop between ROS-regulated Keap1-Nrf2 and Atg7-regulated autophagy. Our data indicate that excessive ROS causes the upregulation of autophagy, and autophagy acts as an antioxidant feedback response triggered by cytotoxic levels of MitoQ.

Conditioned medium (CM) derived from mesenchymal stem cells (MSCs) contains bioactive molecules including microRNAs (miRs) that could be a potential tool for controlling cancer cells' behavior. Due to the properties of CM, this study assesses the effects of miR-34a related MSCCM on tumor behavior through the evaluation of migration, invasion, apoptosis, and PDL1 expression in breast cancer cell lines. The miR-34a overexpression vector or scramble control was produced using lentiviral vectors, DNA cloning, and the transfection of the HEK-293 T cell line. It was then transduced into human adipose-derived mesenchymal stem cells (hAD-MSCs). MSC-CMs were collected and added onto MDA-MB-231 cell lines. The functional evaluations were performed by transwell, wound healing, and Annexin V/PI methods on the treated MDA-MB-231 cell lines. The PDL1 expression was also assessed by Real-time PCR and western blot. The findings of this study showed that ectopic miR-34a expression was significantly upregulated in manipulated hASC with miR-34a (p<0.0001). Treatment of MDA-MB-231 cell line with miR-34a-hAD-MSC-CM, scramble-hAD-MSC-CM, or hAD-MSC-CM displayed not only a reduction in the number of migrated or invaded cells (p=0.01) but also an increase in the apoptotic cells in the test group (p=0.02) when compared to the control groups. It also showed down-regulation in the gene (p=0.05) and protein expression levels of PDL1 in the test group. The results of the present study showed that simultaneous application of miR-34a and MSCCM can be considered as a new method for changing the cancerous microenvironment; and therefore, as a potential strategy in breast cancer therapy. [ABSTRACT FROM AUTHOR]

Signals downstream of growth factor receptors play an important role in mammary carcinogenesis. Recently, we demonstrated that the small GTPases ARF1 and ARF6 were shown to be activated downstream of the epidermal growth factor receptor (EGFR) and act as a key regulator of growth, migration, and invasion of breast cancer cells. However, the mechanism via which the EGFR recruits and activates ARF1 and ARF6 to transmit signals has yet to be fully elucidated. Here, we identify adaptor proteins Grb2 and p66Shc as important regulators mediating ARF activation. We demonstrate that ARF1 can be found in complex with Grb2 and p66Shc upon EGF stimulation of the basal-like breast cancer MDA-MB-231 cell line. However, we report that these two adaptors regulate ARF1 activation differently, with Grb2 promoting ARF1 activation and p66Shc blocking this response. Furthermore, we show that Grb2 is essential for the recruitment of ARF1 to the EGFR, whereas p66Shc hindered ARF1 receptor recruitment. We demonstrate that the negative regulatory role of p66Shc stemmed from its ability to block the recruitment of Grb2/ARF1 to the EGFR. Conversely, p66Shc potentiates ARF6 activation as well as the recruitment of this ARF isoform to the EGFR. Interestingly, we demonstrate that Grb2 is also required for the activation and receptor recruitment of ARF6. Additionally, we show an important role for p66Shc in modulating ARF activation, cell growth, and migration in HER2-positive breast cancer cells. Together, our results highlight a central role for adaptor proteins p66Shc and Grb2 in the regulation of ARF1 and ARF6 activation in invasive breast cancer cells.

Our previous studies showed that (-)-epigallocatechin-3-gallate (EGCG) inhibits signal transducer activator of transcription 1 (STAT1) activation. Since EGCG may be a promising lead compound for new anti-STAT1 drug design, 15 synthetic catechins, characterized by the (-)-gallocatechin-3-gallate stereochemistry, were studied in the human mammary MDA-MB-231 cell line to identify the minimal structural features that preserve the anti-STAT1 activity. We demonstrate that the presence of three hydroxyl groups of B ring and one hydroxyl group in D ring is essential to preserve their inhibitory action. Moreover, a possible molecular target of these compounds in the STAT1 pathway was investigated. Our results demonstrate a direct interaction between STAT1 protein and catechins displaying anti-STAT1 activity. In particular, surface plasmon resonance (SPR) analysis and molecular modeling indicate the presence of two putative binding sites (a and b) with different affinity. Based on docking data, site-directed mutagenesis was performed, and interaction of the most active catechins with STAT1 was studied with SPR to test whether Gln518 on site a and His568 on site b could be important for the catechin-STAT1 interaction. Data indicate that site b has higher affinity for catechins than site a as the highest affinity constant disappears in the H568A-STAT1 mutant. Furthermore, Janus kinase 2 (JAK2) kinase assay data suggest that the contemporary presence in vitro of STAT1 and catechins inhibits JAK2-elicited STAT1 phosphorylation. The very tight catechin-STAT1 interaction prevents STAT1 phosphorylation and represents a novel, specific and efficient molecular mechanism for the inhibition of STAT1 activation., (© 2013 FEBS.)

Organosulfur compounds from garlic effectively inhibit growth of transplanted as well as spontaneous cancers in preclinical animal models without any adverse side effects. However, the mechanisms underlying anticancer effect of this class of compounds are not fully understood. This study reports, for the first time, that garlic organosulfide diallyl trisulfide (DATS) inhibits estrogen receptor-α (ER-α) activity in human breast cancer cells. Exposure of MCF-7 and T47D cells to DATS resulted in downregulation of ER-α protein, which peaked between 12- and 24-h post-treatment. DATS was relatively more effective in suppressing ER-α protein expression compared with its mono and disulfide analogs. The 17β-estradiol (E2)-induced expression of pS2 and cyclin D1, ER-α target gene products, was also decreased in the presence of DATS. Downregulation of ER-α protein expression resulting from DATS treatment was accompanied by a decrease in nuclear levels of ER-α protein, ER-α mRNA suppression, and inhibition of ERE2e1b-luciferase reporter activity. DATS-mediated inhibition of cell viability and apoptosis induction were not affected in the presence of E2. In agreement with these results, ectopic expression of ER-α in MDA-MB-231 cell line failed to confer any protection against cell proliferation inhibition or apoptosis induction resulting from DATS exposure. DATS treatment caused a decrease in protein levels of peptidyl-prolyl cis-trans isomerase (Pin1), and overexpression of Pin1 partially attenuated ER-α downregulation by DATS. DATS-induced apoptosis was modestly but significantly augmented by overexpression of Pin1. In conclusion, this study identifies ER-α as a novel target of DATS in mammary cancer cells.