Mammary Breast Cancer Cells Research Articles

Phytochemical Profile and Antioxidant, Enzyme-Inhibitory, and Cytotoxic Potential of Endemic Cynoglottis chetikiana subsp. chetikiana

Background Cynoglottis chetikiana subsp. chetikiana, an endemic Boraginaceae plant growing in Turkey, has not been previously studied in terms of pharmacognosy. However, related species, such as Anchusa, Symphytum, and Rindera, have been known for their pharmacological effects attributed to compounds such as flavonoids, terpenoids, and other phenol derivatives. Purpose This study aimed to reveal the phytochemical composition and potential biological activity of C. chetikiana. Methods Phytochemical profiling analysis was performed by using the liquid chromatography–high-resolution mass spectrometry (LC–HRMS) system. The cytotoxic effects of the extracts were evaluated on the MCF-7 mammalian breast cancer cell line by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) method. The in vitro α-glucosidase and tyrosinase enzyme inhibitory activities were assessed using literature methods. Additionally, antioxidant properties were investigated, leading to the bioactivity-guided isolation of the most active substance. Results LC–HRMS analysis revealed 27 major phenolic compounds and 2 pyrrolizidine alkaloids in C. chetikiana. Bioactivity-guided studies led to the isolation of a flavonoid, rutin. The n-butanol extract of the plant exhibited high antioxidant capacity and was rich in phenolic compounds. The methanol extract of C. chetikiana demonstrated low-moderate α-glucosidase inhibitory activity (IC50 = 608.62 ± 7.01 µg/mL). Moreover, the methanol extract showed significant anti-tyrosinase enzyme activity (195.84 ± 5.81 mg Kojic acid equivalent/g extract), and the petroleum ether extract displayed the highest cytotoxicity on MCF-7 cells (IC50 = 76.91 ± 3.12 µg/mL). Conclusion This is the first phytomedicinal study report for C. chetikiana, which gives promising insight for further pharmaceutical research.

Plasma Rhenium and Selenium Concentrations After Repeated Daily Oral Administration of Rhenium(I)-diselenoether in 4T1 Breast Tumor-bearing Mice.

Rhenium(I)-diselenoether (Re-diSe) is a compound combining a rhenium tricarbonyl(I) core with a diselenide ligand. A high dose of 60 mg/kg had a pro-tumor effect in a previous study, in non-immune deficient 4T1 tumor-bearing mice, while doses of 1 and 10 mg/kg did not affect tumor growth, after repeated oral administrations. This study aimed to examine the tumor effects of a lower dose of 0.1 mg/kg with the same experimental design and to assay plasma Re and Se concentrations. Syngenic BALB/cByJ (JAX) mice were orthotopically inoculated with 4T1 mammary breast cancer cells. Re-diSe was daily administered orally for 23 days at doses of 0.1, 1, and 10 mg/kg, whereas controls received no treatment. Tumor and mice weights were measured at the end of the experiment. Plasma Re and Se concentrations were assayed by an inductively coupled plasma sector field mass spectrometry instrument (ICP-sf-MS). The weight of the tumors did not vary in treated versus non-treated mice. The limit of detection (LOD) of Re was 0.34 nmol/l. Plasma Re concentrations were 14±20 nmol/l at doses of 0.1 mg/kg, and increased at higher doses, up to 792±167 nmol/l at doses of 10 mg/kg. Plasma Se concentrations were significantly increased in mice treated with the dose of 0.1 mg/kg (4,262±1,511 nmol/l) versus controls (1,262±888 nmol/l), but not from 0.1 to 1 mg/kg, nor from 1 to 10 mg/kg. The 0.1 mg/kg dose of Re-diSe resulted in detectable plasma Re concentrations and significantly increased plasma Se concentrations. In the future, doses as low as 0.1 mg/kg of Re-diSe will be tested, exploring its potential immune interest as a metronomic schedule of treatment, but in mouse models that readily develop extensive metastatic disease.

Synthesis, characterization, anti-bacterial and anticancer activities of Palladium(II) mixed ligand complexes of 2-mercapto-5-methyl-1,3,4-thiadiazole (HmtzS) and phosphines. Crystal structure of [Pd(mtzS)2(dppf)].H2O.EtOH

Two thione and thionate based complexes were synthesized by simply reacting the ligand 2-mercapto-5-methyl-1,3,4-thiadiazole (HmtzS) with palladium(II) salt in a neutral or basic medium in 2:1 molar ratio. Reacting of resulting complex [Pd(mtzS)2] (2) with Ph2P(CH2)nPPh2 (n = 1–4), dppf, Ph3P or Ph3PS yielded mononuclear complexes, [Pd(mtzS)2(Ph2P(CH2)nPPh2)] (3–5), [Pd(mtzS)2(dppf)] (6), [Pd(mtzS)2(Ph3P)2] (7) or [Pd(mtzS)2(Ph3PS)2] (8). An X-ray structure of [Pd(mtzS)2(dppf)] (6) shows that the mtzS ligand is now coordinated in a monodentate fashion via the sulfur atom.. The prepared complexes were screened against Pseudomonas aeruginosa, Bacillus subtilis, Staphylococcus aurous, Escherichia coli and S. typhi. Moreover the cytotoxicity of the prepared complexes were evaluated against colon mammalian cancer (LoVo) and breast cancer (MCF-7) cell lines by MTT assay. Results shows that complexes exhibited cytotoxicity with IC50 values within (9.7 ± 1.2) to (39.1 ± 7.6) µM range against LoVo and within (8.8 ± 1.4) to (40.2 ± 2.6) µM range against MCF-7 cell lines.

Relationship between the oxidative status and the tumor growth in transplanted triple-negative 4T1 breast tumor mice after oral administration of rhenium(I)-diselenoether

BackgroundSelective inhibitory effects of rhenium(I)-diselenoether (Re-diSe) were observed in cultured breast malignant cells. They were attributed to a decrease in Reactive Oxygen Species (ROS) production. A concomitant decrease in the production of Transforming Growth Factor-beta (TGFβ1), Insulin Growth Factor 1 (IGF1), and Vascular Endothelial Growth Factor A (VEGFA) by the malignant cells was also observed. AimThe study aimed to investigate the anti-tumor effects of Re-diSe on mice bearing 4T1 breast tumors, an experimental model of triple-negative breast cancer, and correlate them with several biomarkers. Material and methods4T1 mammary breast cancer cells were orthotopically inoculated into syngenic BALB/c Jack mice. Different doses of Re-diSe (1, 10, and 60 mg/kg) were administered orally for 23 consecutive days to assess the efficacy and toxicity. The oxidative status was evaluated by assaying Advanced Oxidative Protein Products (AOPP), and by the dinitrophenylhydrazone (DNPH) test in plasma of healthy mice, non-treated tumor-bearing mice (controls), treated tumor-bearing mice, and tumors in all tumor-bearing mice. Tumor necrosis factor (TNFα), VEGFA, VEGFB, TGFβ1, Interferon, and selenoprotein P (selenoP) were selected as biomarkers. ResultsDoses of 1 and 10 mg/kg did not affect the tumor weights. There was a significant increase in the tumor weights in mice treated with the maximum dose of 60 mg/kg, concomitantly with a significant decrease in AOPP, TNFα, and TGFβ1 in the tumors. SelenoP concentrations increased in the plasma but not in the tumors. ConclusionWe did not confirm the anti-tumor activity of the Re-diSe compound in this experiment. However, the transplantation of the tumor cells did not induce an expected pro-oxidative status without any increase of the oxidative biomarkers in the plasma of controls compared to healthy mice. This condition could be essential to evaluate the effect of an antioxidant drug. The choice of the experimental model will be primordial to assess the effects of the Re-diSe compound in further studies.

Controlled Delivery of Pan-PAD-Inhibitor Cl-Amidine Using Poly(3-Hydroxybutyrate) Microspheres.

This study deals with the process of optimization and synthesis of Poly(3-hydroxybutyrate) microspheres with encapsulated Cl-amidine. Cl-amidine is an inhibitor of peptidylarginine deiminases (PADs), a group of calcium-dependent enzymes, which play critical roles in a number of pathologies, including autoimmune and neurodegenerative diseases, as well as cancer. While Cl-amidine application has been assessed in a number of in vitro and in vivo models; methods of controlled release delivery remain to be investigated. P(3HB) microspheres have proven to be an effective delivery system for several compounds applied in antimicrobial, wound healing, cancer, and cardiovascular and regenerative disease models. In the current study, P(3HB) microspheres with encapsulated Cl-amidine were produced in a size ranging from ~4–5 µm and characterized for surface morphology, porosity, hydrophobicity and protein adsorption, in comparison with empty P(3HB) microspheres. Cl-amidine encapsulation in P(3HB) microspheres was optimized, and these were found to be less hydrophobic, compared with the empty microspheres, and subsequently adsorbed a lower amount of protein on their surface. The release kinetics of Cl-amidine from the microspheres were assessed in vitro and expressed as a function of encapsulation efficiency. There was a burst release of ~50% Cl-amidine in the first 24 h and a zero order release from that point up to 16 days, at which time point ~93% of the drug had been released. As Cl-amidine has been associated with anti-cancer effects, the Cl-amidine encapsulated microspheres were assessed for the inhibition of vascular endothelial growth factor (VEGF) expression in the mammalian breast cancer cell line SK-BR-3, including in the presence of the anti-proliferative drug rapamycin. The cytotoxicity of the combinatorial effect of rapamycin with Cl-amidine encapsulated P(3HB) microspheres was found to be 3.5% more effective within a 24 h period. The cells treated with Cl-amidine encapsulated microspheres alone, were found to have 36.5% reduction in VEGF expression when compared with untreated SK-BR-3 cells. This indicates that controlled release of Cl-amidine from P(3HB) microspheres may be effective in anti-cancer treatment, including in synergy with chemotherapeutic agents. Using controlled drug-delivery of Cl-amidine encapsulated in Poly(3-hydroxybutyrate) microspheres may be a promising novel strategy for application in PAD-associated pathologies.

Improving Cytotoxicity against Breast Cancer Cells by Using Mixed-Ligand Ruthenium(II) Complexes of 2,2'-Bipyridine, Amino Acid, and Nitric Oxide Derivatives as Potential Anticancer Agents.

Several metal-based molecules that display cytotoxicity against multiple cell lines have been pursued in an attempt to fight against cancer and to overcome the typical side effects of drugs like cisplatin. In this scenario, ruthenium complexes have been extensively studied due to their activity in both in vitro and in vivo biological systems, including various cancer cell strains. We aimed to develop a method to synthesize novel [Ru(NO)(bpy)2L2]2+ complexes containing amino acid ligands by using an alternative Click Chemistry approach, namely the copper azide-alkyne cycloaddition reaction (CuAAC reaction), to construct nitrosyl/nitrite complexes bearing a modified lysine residue. We synthesized a new ligand by Click Chemistry approach and new compounds bearing the unprecedented ligand. Cytotoxicity was assessed by the classical MTT colorimetric assay. MCF-7 and MDAMB- 231 cells were used as breast cancer cell models. MCF-10 was used as a model of healthy cells. Amino acid ligands related to N3-Lys(Fmoc) and the new pyLys were successfully synthesized by the diazotransfer reaction and the CuAAC reaction, respectively. The latter reaction involves coupling between N3-Lys(Fmoc) and 3ethynylpyridine. Both N3-Lys(Fmoc) and the new pyLys were introduced into the ruthenium bipyridine complex I, or cis-[RuII(NO)(NO2)(bpy)2]2+, to generate the common nitro-based complex III, which was further converted to the final complex IV. Results of the MTT assay proved the cytotoxic effect of cis- [RuII(NO)(pyLysO-)(bpy)2](PF6)2 against the mammalian breast cancer cells MCF-7 and MDA-MB231. The viability assays revealed that complex IV, bearing a NO group and a modified lysine residue, was able to release NO and cross tumor cell membranes. In this work, Complex IV was observed to be the most active ruthenium bipyridine complex against the mammalian breast cancer cells MCF-7 and MDA-MB231: it was approximately twice as active as cisplatin, whilst complexes I-III proved to be less cytotoxic than complex IV. Additional tests using healthy MCF 10A cells showed that complexes II-IV were three- to sixfold less toxic than cisplatin, which suggested that complex IV was selective against cancer cells.

In vitro toxicological assessment of flumethrin's effects on MCF-7 breast cancer cells.

Pyrethroid pesticides are frequently used for household insect control of insects and in agriculture and livestock. Flumethrin is a pyrethroid that is used against ectoparasites in many animals. The goal of this study was to evaluate the cytotoxic, apoptotic, genotoxic, and estrogenic effects of flumethrin on the mammalian breast cancer cell line (MCF-7). Compared with control groups, a dose-dependent decrease was observed in cell viability at concentrations of 100 µM and higher. The cytotoxic and apoptotic effects detected by LDH assay and AO/EtBr staining increased significantly at a concentration of 1000 µM. The expression of BCL2, which is an anti-apoptotic gene, significantly decreased, whereas BAX, TP53, and P21 expression significantly increased. The results of a comet assay indicated that flumethrin significantly changed tail length, tail % DNA, tail moment, and Olive tail moment in concentrations above 1 and 10 µM. In addition, a 0.1 µM concentration of flumethrin affected ERα receptor mediated cell proliferation and increased transcription of estrogen-responsive pS2 (TFF1) and progesterone receptor (PGR) genes. As a result, flumethrin-induced apoptosis and cytotoxicity at a high concentration, while induced genotoxicity even at lower concentrations. Flumethrin is an endocrine disrupting insecticide with estrogenic effects at very low concentrations.

Isolation of an acidic polysaccharide from the flowers of Leucosceptrum canum Smith and its immunomodulatory activity evaluation

A water-soluble polysaccharide (LCP-05) was isolated from the flowers of Leucosceptrum canum Smith. LCP-05 was an acidic polysaccharide with a molecular weight of approximately 8.9 kDa. Monosaccharide composition analysis indicated that LCP-05 was composed of Man, Rha, GlcA, GalA, Glc, Gal and Ara in a molar ratio of 0.83:1.68:0.33:2.15:1.00:1.45:1.22. The framework of LCP-05 was speculated to be a branched rhamnogalacturonan with the backbone consisting of α-1,2,4-linked Rhap and α-1,4-linked GalAp, and bearing branches at the O-4 position of the Rha residues. The side chains are terminated primarily with the Araf and Glcp residues. LCP-05 was found to be able to significantly induce the production of NO, IL-6, and TNF-α in RAW 264.7 cells, and to induce RAW 264.7 cell's suppressive effect on both cell growth and cell migration of 4 T1 mammary breast cancer cells.

Graphene Enclosure of Chemically Fixed Mammalian Cells for Liquid-Phase Electron Microscopy.

A protocol is described for investigating the human epidermal growth factor receptor 2 (HER2) in the intact plasma membrane of breast cancer cells using scanning transmission electron microscopy (STEM). Cells of the mammalian breast cancer cell line SKBR3 were grown on silicon microchips with silicon nitride (SiN) windows. Cells were chemically fixed, and HER2 proteins were labeled with quantum dot nanoparticles (QDs), using a two-step biotin-streptavidin binding protocol. The cells were coated with multilayer graphene to maintain a hydrated state, and to protect them from electron beam damage during STEM. To examine the stability of the samples under electron beam irradiation, a dose series experiment was performed. Graphene-coated and non-coated samples were compared. Beam induced damage, in the form of bright artifacts, appeared for some non-coated samples at increased electron dose D, while no artifacts appeared on coated samples.

Cyclic Organoselenide BODIPY-Based Probe: Targeting Superoxide in MCF-7 Cancer Cells.

All aerobic cells contain reactive oxygen species (ROSs) in balance with biochemical antioxidants. Oxidative stress is developed when this balance gets disturbed because of excessive production of ROSs or depletion of antioxidants. Here, in this work, we have developed the first cyclic diselenide BODIPY-based (organoselenium-containing) probe for the selective detection of superoxide. The probe demonstrates excellent selective response for superoxide over other ROSs with nine-fold increase in fluorescence intensity. The detection limit was found to be 0.924 μM. The plausible “turn-on” mechanism has been proposed based on the spectroscopic and quantum chemical data. Usefulness of the probe for selective detection of superoxide was confirmed in mammalian breast cancer cell lines.

Cancer Cell Growth in the Near Infrared Region by Using Silica Coated Gold Nanorods

Gold nanorods (AuNRs) have been considered as suitable materials for diverse biomedical applications in controlling cell behaviors. The nanoisland system with well-dispersed silica coated Au nanorods (Si-AuNRs) was used to demonstrate the enhanced cell growth of normal and cancer cells (MDA-MB-231 mammalian breast cancer cells) from the induced expressions of the heat shock proteins (HSPs). The over-expressions of HSP could help in protein folding in cell proliferations and growths of both the normal and cancer cells. In the current study, interesting mechanisms of cancer cell growth with Si-AuNRs than the conventional systems, such as incubator, would be presented. We believe that the growth of cancer cells in near infrared (NIR) region using Si-AuNRs induced the activities of HSPs, which could help the protein folding in cell growth and survival in comparison to the cells grown in the incubator only. The cell growth enhancing technology could be expanded in diverse applications in cell culture systems.

Hormonal Therapy Resistance and Breast Cancer: Involvement of Adipocytes and Leptin.

Obesity, a recognized risk factor for breast cancer in postmenopausal women, is associated with higher mortality rates regardless of menopausal status, which could in part be explained by therapeutic escape. Indeed, adipose microenvironment has been described to influence the efficiency of chemo- and hormonal therapies. Residual cancer stem cells could also have a key role in this process. To understand the mechanisms involved in the reduced efficacy of hormonal therapy on breast cancer cells in the presence of adipose secretome, human adipose stem cells (hMAD cell line) differentiated into mature adipocytes were co-cultured with mammary breast cancer cells and treated with hormonal therapies (tamoxifen, fulvestrant). Proliferation and apoptosis were measured (fluorescence test, impedancemetry, cytometry) and the gene expression profile was evaluated. Cancer stem cells were isolated from mammospheres made from MCF-7. The impact of chemo- and hormonal therapies and leptin was evaluated in this population. hMAD-differentiated mature adipocytes and their secretions were able to increase mammary cancer cell proliferation and to suppress the antiproliferative effect of tamoxifen, confirming previous data and validating our model. Apoptosis and cell cycle did not seem to be involved in this process. The evaluation of gene expression profiles suggested that STAT3 could be a possible target. On the contrary, leptin did not seem to be involved. The study of isolated cancer stem cells revealed that their proliferation was stimulated in the presence of anticancer therapies (tamoxifen, fulvestrant, doxorubicine) and leptin. Our study confirmed the role of adipocytes and their secretome, but above all, the role of communication between adipose and cancer cells in interfering with the efficiency of hormonal therapy. Among the pathophysiological mechanisms involved, leptin does not seem to interfere with the estrogenic pathway but seems to promote the proliferation of cancer stem cells.

Synthesis, characterization, DNA binding, topoisomerase inhibition, and apoptosis induction studies of a novel cobalt(III) complex with a thiosemicarbazone ligand

In this study, 9-anthraldehyde-N(4)-methylthiosemicarbazone (MeATSC) 1 and [Co(phen)2(O2CO)]Cl·6H2O 2 (where phen = 1,10-phenanthroline) were synthesized. [Co(phen)2(O2CO)]Cl·6H2O 2 was used to produce anhydrous [Co(phen)2(H2O)2](NO3)33. Subsequently, anhydrous [Co(phen)2(H2O)2](NO3)33 was reacted with MeATSC 1 to produce [Co(phen)2(MeATSC)](NO3)3·1.5H2O·C2H5OH 4. The ligand, MeATSC 1 and all complexes were characterized by elemental analysis, FT IR, UV–visible, and multinuclear NMR (1H, 13C, and 59Co) spectroscopy, along with HRMS, and conductivity measurements, where appropriate. Interactions of MeATSC 1 and complex 4 with calf thymus DNA (ctDNA) were investigated by carrying out UV–visible spectrophotometric studies. UV–visible spectrophotometric studies revealed weak interactions between ctDNA and the analytes, MeATSC 1 and complex 4 (Kb = 8.1 × 105 and 1.6 × 104 M−1, respectively). Topoisomerase inhibition assays and cleavage studies proved that complex 4 was an efficient catalytic inhibitor of human topoisomerases I and IIα. Based upon the results obtained from the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay on 4T1-luc metastatic mammary breast cancer cells (IC50 = 34.4 ± 5.2 μM when compared to IC50 = 13.75 ± 1.08 μM for the control, cisplatin), further investigations into the molecular events initiated by exposure to complex 4 were investigated. Studies have shown that complex 4 activated both the apoptotic and autophagic signaling pathways in addition to causing dissipation of the mitochondrial membrane potential (ΔΨm). Furthermore, activation of cysteine-aspartic proteases3 (caspase 3) in a time- and concentration-dependent manner coupled with the ΔΨm, studies implicated the intrinsic apoptotic pathway as the major regulator of cell death mechanism.

17β-Estradiol Activates HSF1 via MAPK Signaling in ERα-Positive Breast Cancer Cells.

Heat Shock Factor 1 (HSF1) is a key regulator of gene expression during acute environmental stress that enables the cell survival, which is also involved in different cancer-related processes. A high level of HSF1 in estrogen receptor (ER)-positive breast cancer patients correlated with a worse prognosis. Here we demonstrated that 17β-estradiol (E2), as well as xenoestrogen bisphenol A and ERα agonist propyl pyrazole triol, led to HSF1 phosphorylation on S326 in ERα positive but not in ERα-negative mammary breast cancer cells. Furthermore, we showed that MAPK signaling (via MEK1/2) but not mTOR signaling was involved in E2/ERα-dependent activation of HSF1. E2­activated HSF1 was transcriptionally potent and several genes essential for breast cancer cells growth and/or ERα action, including HSPB8, LHX4, PRKCE, WWC1, and GREB1, were activated by E2 in a HSF1-dependent manner. Our findings suggest a hypothetical positive feedback loop between E2/ERα and HSF1 signaling, which may support the growth of estrogen-dependent tumors.

Accumulation and cytotoxicity assessment of TAT-IONPs on cancerous mammalian cells

Nanotechnology is a fast-growing research technology. Nanoparticles have intensive scientific applications in many fields. Depending on the physical and chemical characteristics of a nanoparticle, it can be used either as a treatment agent to fight disease or as a delivery vehicle to transport the therapeutic drug to a specified biological organ, tissue, and cell. Cytotoxicity evaluation of nanoparticles is one of the primary concerns in clinical practices to avoid unpredicted or undesirable interactions that could worsen the case. Iron oxide nanoparticle (IONP) is the most utilized nanoparticle in medical fields for treatment, diagnostic, and imaging. This paper is designated to investigate the cytotoxicity of IONPs that decorated with Trans-Activator of Transcription (TAT) protein. WST-1 assay and flow cytometry were used to assess the cytotoxicity of TAT-IONPs, which showed no significant cytotoxic effect on mammalian breast cancer cells (MCF-7). Nanoparticles accumulation in the cell’s cytoplasm was evaluated from TEM images by measuring the size of the endosome. The results indicate that TAT-IONPs can be used as a safe and non-toxic nanoplatform for targeted delivery at 50 µg/ml or less. Also, they present an approach by which the area of intracellular endosome can be assessed from the TEM images of fixed cells. In this study, the endosome size increased in a time-dependent manner.

The triacylglycerol, hydroxytriolein, inhibits triple negative mammary breast cancer cell proliferation through a mechanism dependent on dihydroceramide and Akt.

The plasma membrane is an attractive target for new anticancer drugs, not least because regulating its lipid structure can control multiple signaling pathways involved in cancer cell proliferation, differentiation and survival. Accordingly, the novel anticancer drug hydroxytriolein (HTO) was designed to interact with and regulate the composition and structure of the membrane, which in turn controls the interaction of amphitropic signaling membrane proteins with the lipid bilayer. Changes in signaling provoked by HTO impair the growth of triple negative breast cancer (TNBC) cells, aggressive breast tumor cells that have a worse prognosis than other types of breast cancers and for which there is as yet no effective targeted therapy. HTO alters the lipid composition and structure of cancer cell membranes, inhibiting the growth of MDA-MB-231 and BT-549 TNBC cells in vitro. Depending on the cellular context, HTO could regulate two pathways involved in TNBC cell proliferation. On the one hand, HTO might stimulate ERK signaling and induce TNBC cell autophagy, while on the other, it could increase dihydroceramide and ceramide production, which would inhibit Akt independently of EGFR activation and provoke cell death. In vivo studies using a model of human TNBC show that HTO and its fatty acid constituent (2-hydroxyoleic acid) impair tumor growth, with no undesired side effects. For these reasons, HTO appears to be a promising anticancer molecule that targets the lipid bilayer (membrane-lipid therapy). By regulating membrane lipids, HTO controls important signaling pathways involved in cancer cell growth, the basis of its pharmacological efficacy and safety.

MicroRNA modified tumor-derived exosomes as novel tools for maturation of dendritic cells.

Tumor-derived exosomes (TEX) are known by their immune suppression effects as well as initiation mediators in cancer progression and metastasis. Meanwhile, they are appropriate sources to induce immunity against tumor cells, as consist of tumor specific and associated antigens. The aim of the current study is modifying TEX with microRNA miR-155, miR-142, and let-7i, to enhance their immune stimulation ability and induce potent dendritic cells (DC). For this, exosomes were isolated from mouse mammalian breast cancer cell line; 4T1, and subjected to miR-155, miR-142, and let-7i by electroporation. Immature DCs were generated from mouse bone marrow in the presence of interleukin-4 (IL-4) and granulocyte-macrophage colony-stimulating factor (GM-CSF). To mature DCs, lipopolysaccharide (LPS), TEX, and modified TEX were used. The expression level of miRNAs and their target genes (IL-6, IL-17, IL-1b, TGFβ, SOCS1, KLRK1, IFNγ, and TLR4) was determined. TEX were nanovesicles with spheroid morphology which expressed CD81, CD63, and TSG101, as exosome markers, at protein level. MHCII, CD80, and CD40 as maturation markers were assessed by flow cytometry. Overexpression of miRNAs were confirmed in exosomes and mDCs. Up and downregulation of target genes confirmed the gene network in DC maturation. We found that Let-7i could efficiently induce the DC maturation, as well as miR-142 and miR-155 have enhancing effects. These findings reveal that the modified TEX would be a hopeful cell-free vaccine for the cancer treatment.

Phenylselenyl containing turn-on dibodipy probe for selective detection of superoxide in mammalian breast cancer cell line

A monoselenium containing diBODIPY-based probe was synthesized. The probe was found to be selective and sensitive for the detection of superoxide (KO2) over other reactive oxygen species through fluorescence turn-on event with 11-fold increase in fluorescence intensity. The detection limit was found to be 4.42 μM. The utility of the probe for detection of intracellular superoxide was demonstrated in a mammalian breast cancer cell line (MCF-7) through fluorescence microscopy.

Anti-tumor activity of Escherichia coli Shiga toxin A subunit delivered by SF9 insect cells

Cancer remains a major health problem around the world. A Shiga toxin is a bacterial toxin often produced by Shigella dysenteriae and Escherichia coli. A subunit of the Shiga toxin (StxA) is a cytotoxic agent which could be used to induce death in cancer cells.StxA expressed from baculovirus was evaluated in a pTriEx™ expression vector. The baculovirus vector was used for the A subunit delivery of StxA. StxA cell cytotoxicity was induced by the virus and assessed in the MCF7 and HeLa cell lines. In addition, the breast cancer cytotoxicity of the expressed StxA was also assessed in a cancer induced in mice.The cytotoxicity of the recombinant StxA baculovirus with different multiplicities of infection (MOI) was measured. The results showed that significant cytotoxicity can be induced on the mammalian epithelial breast cancer cell lines, MCF7 and HeLa cells with MOI ≥ 2. The results also showed that a malignant tumor induced by MCF7 could be inhibited in a mouse cancer model.Therefore, it can be concluded that StxA, expressed by baculovirus, could be used for in vitro and in vivo gene delivery. In this study StxA, delivered by the baculovirus inhibited cell proliferation, and eliminated HeLa and MCF7 cells, in vitro. In conclusion, this method can be used as a safe alternative for anticancer drug delivery inside cancer cells.

Metabolomic Analysis of HER2‐positive Breast Cancer Cells

PurposeHER2‐positive breast cancer accounts for more than 20% of the diagnosed cases and is characterized by aggressive growth, increased disease recurrence, and poor prognosis. While much of the signaling mechanism(s) have been elucidated, the impact of HER2 positivity on cellular metabolism is not well understood. We examined (1) gene expression profiles of mammalian breast cancer cell lines with increasing HER2 expression levels (MCF10A, MDA‐MB‐468, MDA‐MB‐453, HCC1954, HCC2218) and correlated changes to metabolic expression profiles and (2) the effect of serum starvation and pervanadate treatment on the metabolic profiles of these HER2‐expressing cell lines.MethodsOur study used a combination of 1H‐NMR and 2D‐NMR (TOCSY), multivariate analyses, and protein expression validation in human breast cancer cell lines (untreated, serum‐starved, serum‐starved with pervanadate treatment).ResultsWe found that both gene and metabolic expression profiles of HER2‐positive cell lines correlated with leucine and isoleucine biosynthesis (p‐value < 0.05). Comparative analyses of profiles from untreated, serum‐starved, and serum‐starved with pervanadate‐treated cell samples revealed that lactate concentration (p‐value <0.05) dropped significantly with serum starvation and pervanadate treatment consistent with reduced glycolytic metabolism and potentially mediated through suppression of tyrosine phosphatase activity.ConclusionThis study highlights important metabolites that are potential biomarkers of HER2‐positive breast cancer and suggests alternate/novel pathways to consider for future understanding and treatment.Support or Funding InformationThis work was funded in part through intramural programs at Fresno State to MKS and JAB, and through the NIGMS 1SC3GM122630‐01 to JAB.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.