Human Breast Adenocarcinoma MCF-7 Cells Research Articles

Metabolic reprogramming by Dichloroacetic acid potentiates photodynamic therapy of human breast adenocarcinoma MCF-7 cells.

Aberrant glycolytic metabolism is one of the hallmarks of carcinogenesis and therefore reversal of metabolic transformation is a promising drug target in cancer treatment strategies. Dichloroacetic acid (DCA) is known to target the glycolytic pathway in cancer cells and facilitates reversal of metabolic transformation from aerobic cytosolic accumulation of pyruvic acid, “the Warburg effect”, to mitochondrial oxidative phosphorylation. Recently, combination therapy particularly involving photodynamic therapy (PDT) has received considerable attention in oncology. We hypothesized that if DCA and PDT are combined, they might potentiate mitochondrial dysfunction and induce apoptosis by a reactive oxygen species (ROS) dependent pathway. We used MCF-7 cells as our in vitro model and 5-aminolevulinic acid (5-ALA) dependent PDT therapy to test our hypothesis. We found that combinatorial treatment of MCF-7 cells with PDT and DCA not only increased cell growth inhibition, but also affected mitochondrial membrane integrity perhaps via production of ROS, and enhanced apoptosis. Further, our results on ATP release during the combined treatment demonstrate that immunogenic cell death (ICD) is likely to be a potential mechanism by which PDT and DCA induce cancer cell death. Taken together, our study suggests a novel way of sensitizing MCF-7 cells for accelerated induction of apoptosis and ICD in these cells. The findings included in this study might have direct relevance in breast cancer treatment strategies.

The investigation of in vitro dark cytotoxicity and photodynamic therapy effect of a 2,6-dibromo-3,5-distyryl BODIPY dye encapsulated in Pluronic® F-127 micelles

A 2,6-dibrominated 3,5-distyryl boron-dipyrromethene (BODIPY) dye with a moderately high singlet oxygen quantum yield was encapsulated in Pluronic® F-127 micelles, and its dark cytotoxicity and photodynamic activity were investigated on the human breast adenocarcinoma MCF-7 cell line. The BODIPY dye exhibited very low dark toxicity and a significant PDT effect when added in drug formulations consisting of 5.0% (v/v) DMSO in supplemented Dulbecco’s modified Eagle’s medium (DMEM) and as Pluronic® F-127 micelle encapsulation complexes in supplemented DMEM alone. An IC50 value of 4 ± 2 μM was obtained when the BODIPY dye was encapsulated in Pluronic® F-127 micelles during in vitro photodynamic activity studies in MCF-7 cancer cells with a 660 nm light emitting diode.

(E)-N-Aryl-2-oxo-2-(3,4,5-trimethoxyphenyl)acetohydrazonoyl cyanides as tubulin polymerization inhibitors: Structure-based bioisosterism design, synthesis, biological evaluation, molecular docking and in silico ADME prediction

A series of (E)-N-Aryl-2-oxo-2-(3,4,5-trimethoxyphenyl)acetohydrazonoyl cyanides have been synthesized and evaluated for their anticancer activity in human hepatocellular liver carcinoma HepG2 and breast adenocarcinoma MCF-7 cell lines. Among all the tested compounds, compound 3a, 3e and 3n displayed more activity than lead compound with IC50 value of 0.26–0.61 μM. Meanwhile, these compounds (3a, 3e and 3n) showed potent antiproliferative activity against a panel of cancer cells and the HCT-8/T multidrug resistant cell line with IC50 values in the range of 0.077– 7.44 μM. Flow cytometric analyses revealed that compound 3n induced cell cycle arrest in G2/M phases in a dose dependent manner. The compound 3n also displayed potent tubulin polymerization inhibition with an IC50 value of 0.9 µM, with ten folds more active than colchicine (IC50 = 9 μM). Molecular docking studies revealed that compound 3n efficiently interacted with the colchicine binding site of tubulin through hydrophobic, cation-π and hydrogen bond interaction. Furthermore, in silico pharmacokinetic prediction shown that these compounds have a good ADME-related physicochemical parameters. These results demonstrate that 3n exhibits potent cytotoxicity in cancer cells by targeting the colchicine binding site of tubulin and potentially acts as a therapeutic lead compound for the development of anticancer drugs.

Augmented anticancer activity of naringenin-loaded TPGS polymeric nanosuspension for drug resistive MCF-7 human breast cancer cells

Naringenin (NAR) is a naturally occurring plant flavonoid, found predominantly in citrus fruits, possesses a wide range of pharmacological properties. However, despite the therapeutic potential of NAR, its clinical development has been hindered due to low aqueous solubility and inefficient transport across biological membranes resulting in low bioavailability at tumor sites. In our previous studies, nanosuspension of naringenin (NARNS) was prepared using high pressure homogenization method using different polymers. D-α-Tocopheryl polyethylene glycol succinate 1000 (TPGS) was added as a co-stabilizer. All formulation characterization studies were performed. As a continuation of our previous research, current study has further evaluated the ability of the TPGS-coated NARNS, to reverse drug-resistance of P-gp-over expressing MCF-7 human breast adenocarcinoma cell line and animal model. MTT-based colorimetric assay revealed higher cytotoxic efficacy of NARNS than free NAR in MCF-7 cells. NARNS treatment significantly increased intracellular ROS level, mitochondrial membrane potential, caspase-3 activity, lipid peroxidation status (TBARS) and decreased GSH levels when compared to free NAR treatment in MCF-7 cells. It has been also noticed that the presence of apoptotic indices (membrane blebbing, nuclear fragmentation) in NARNS treated cancer cells. Further, NARNS exhibited dose-dependent in vitro antitumor activity with DLA cells. A significant increase in the life span and a decrease in the cancer cell number and tumor weight were noted in the tumor-induced mice after treatment with NARNS.

Montmorillonite as imaging and drug delivery agent for cancer therapy

Abstract Montmorillonite (Mt) can be used as a simultaneous medical imaging and drug delivery agent for transcatheter arterial embolization. In this technique, the arterial vessels around tumors are blocked by drug loaded micro-sized Mt particles so oxygen and nutrition from the blood flow are blocked and drugs are released by the particles into the tumor site. Both devascularization (achieved by cutting off the oxygen and the nutrition) and drug release around tumor site can result in the progressive shrinkage of the tumor size. Mt is highly applicable and unique for transcatheter arterial embolization due to the size, adsorption capability, and biocompatibility of the particles. Mt has been considered previously as a targeted drug delivery agent to the gastrointestinal tract only for oral applications due to its slow and sustained drug releasing properties, but it has not yet been investigated as a targeted drug delivery agent for tumors at different or highly-specific areas. In this study, interactions of purified montmorillonite (PMt) with a cone beam computer tomography (CT) contrast material and an antitumor drug were investigated to prepare drug releasing arterial embolic clay mineral particles that enable medical imaging. In-vitro studies were carried out to show the biocompatibility of PMt The swelling and adsorption properties of PMt in the presence of the CT contrast material or antitumor drug were investigated to find a proper concentration for possible embolization. The results show that both the CT contrast material and antitumor drug could penetrate to the interlayer spaces and were adsorbed by the surfaces of the PMt particles. The size of the PMt increased due to both the adsorption and coagulation, which made the particles suitable for the arterial embolization procedure where a specific particle size is required to successfully obtain embolization. In-vivo tests of PMt as a CT contrast carrier and in-vitro drug activity on MCF-7 (human breast adenocarcinoma) cells were also satisfactory using the prepared embolic PMt particles.

Gloriosa superba Mediated Synthesis of Platinum and Palladium Nanoparticles for Induction of Apoptosis in Breast Cancer.

Green chemistry approaches for designing therapeutically significant nanomedicine have gained considerable attention in the past decade. Herein, we report for the first time on anticancer potential of phytogenic platinum nanoparticles (PtNPs) and palladium nanoparticles (PdNPs) using a medicinal plant Gloriosa superba tuber extract (GSTE). The synthesis of the nanoparticles was completed within 5 hours at 100°C which was confirmed by development of dark brown and black colour for PtNPs and PdNPs, respectively, along with enhancement of the peak intensity in the UV-visible spectra. High-resolution transmission electron microscopy (HRTEM) showed that the monodispersed spherical nanoparticles were within a size range below 10 nm. Energy dispersive spectra (EDS) confirmed the elemental composition, while dynamic light scattering (DLS) helped to evaluate the hydrodynamic size of the particles. Anticancer activity against MCF-7 (human breast adenocarcinoma) cell lines was evaluated using MTT assay, flow cytometry, and confocal microscopy. PtNPs and PdNPs showed 49.65 ± 1.99% and 36.26 ± 0.91% of anticancer activity. Induction of apoptosis was most predominant in the underlying mechanism which was rationalized by externalization of phosphatidyl serine and membrane blebbing. These findings support the efficiency of phytogenic fabrication of nanoscale platinum and palladium drugs for management and therapy against breast cancer.

Abstract 5842: Oxidative stress and protein carbonylation towards multi-drug resistance in cancer

Abstract Reactive oxygen species (ROS) are constantly produced under normal as well as stress conditions and play important roles in cell signaling and homeostasis. An elevated level of ROS has been reported in most cancers which may play a critical role in both cancer progression or cancer suppression. One proposed therapeutic strategy is to alter the oxidative stress from ROS-induced tumor promoting event to a ROS-induced apoptotic signaling. Most ROS inducing therapeutic agents initially induce ROS to kill cancer cells by apoptosis; however, prolonged exposure of drugs may result in reduced ROS level and an adaptive microenvironment that makes cancer cells resistant to the same ROS-inducing therapeutic drugs. Chronic exposure of ROS may also upregulate the multidrug resistance protein expression in cancer cells. We hypothesize that differences in oxidative stress and the antioxidant response between drug sensitive and drug resistance cells may play a key role in drug resistance to redox-active drugs. We used two pairs of cell lines, a mitoxantrone sensitive and resistance MCF7 human breast adenocarcinoma (MCF7/MCF7MX) and H460 non-small lung cancer cell lines (H460/H460MX) for our experiments. We employed western blot and ELISA assays to determine the total and specific protein oxidation by carbonylation. Both MCF7MX and H460MX showed slightly lower level of total protein carbonylation compared to their mitoxantrone sensitive counterparts. In western blot analysis, we observed two specific proteins that were differentially carbonylated in MCF7MX compared to and MCF7. Both cytoskeletal and multifunctional proteins were identified by mass spectrometry and confirmed by two-color western blot analysis. Investigation of the potential roles of these specific protein carbonylation in drug resistance will be presented. Citation Format: Baikuntha P. Aryal, Jean-Pierre Gillet, V Ashutosh Rao. Oxidative stress and protein carbonylation towards multi-drug resistance in cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5842.

Exposure to EGF and 17β‑estradiol irreversibly affects the proliferation and transformation of MCF7 cells but is not sufficient to promote tumor growth in a xenograft mouse model upon withdrawal of exposure.

Epidermal growth factor (EGF) and estrogen are potent regulators of breast tumorigenesis. Their short‑term actions on human breast epithelial cells have been investigated extensively. However, the consequence of a long‑term exposure to EGF and estrogen remains to be fully elucidated. The present study examined the effects of long‑term exposure to EGF and 17β‑estradiol on the proliferation, transformation, expression of markers of stemness, and tumorigenesis of MCF7 human breast adenocarcinoma cells. Exposure to EGF and/or 17β‑estradiol irreversibly enhanced the proliferation rate of MCF7 cells, even following withdrawal. However, in a mouse xenograft experiment, no significant difference in tumor volume was observed between tumors derived from cells exposed to EGF, 17β‑estradiol or EGF + 17β‑estradiol. Immunohistochemistry performed on tumors derived from 17β‑estradiol‑exposed cells revealed reduced cell proliferation and vessel scores, according to the results obtained using Ki67 and von Willebrand factor staining, respectively. The EGF‑ and/or 17β‑estradiol‑treated cells exhibited an increased ratio of cluster of differentiation (CD)44+/CD24‑ cells and enhanced ability to form mammospheres. Furthermore, the long‑term exposure of MCF7 cells to EGF and 17β‑estradiol altered their responsiveness to short‑term stimulatory or inhibitory treatments with EGF, 17β‑estradiol, transforming growth factor‑β1 (TGFβ1), Iressa and SB431542. Therefore, the findings indicated that sustained exposure of MCF7 cells to EGF and/or 17β‑estradiol resulted in enhanced cell proliferation and mammosphere formation, an increased ratio of CD44+/CD24‑ cells, and altered responses to short‑term treatments with EGF, 17β‑estradiol, TGFβ1, and drugs inhibiting these signaling pathways. However, this sustained exposure was not sufficient to affect tumor take or volume in a xenograft mouse model.

A novel Met-IR-782 near-infrared probe for fluorescent imaging-guided photothermal therapy in breast cancer.

In this work, a novel photothermal agent based on methionine (Met) was synthesized, which shows strong absorbance in the near infrared ray (NIR) region and is available for NIR imaging and in vivo photothermal therapy in a mouse model. Comparing to free IR-782, the obtained Met modified fluorescent dye (Met-IR-782) exhibited excellent fluorescence stability, preferable photothermal conversion efficiency under 780nm laser irradiation and specific targeting to MCF7 (human breast adenocarcinoma cell line) cells. The fluorescence imaging ability enabled in situ monitoring of the tumor accumulation of Met-IR-782. The photothermal cytotoxicity assays in vitro and photothermal therapy treatments in vivo indicated that Met-IR-782 could efficiently target and suppress the growth of MCF7 xenograft tumors. Hence, Met-IR-782 is a potential fluorescent agent for NIR imaging-guided cancer photothermal therapy in clinical application. This work highlights the prospect of using light absorbing agents for NIR imaging-guided photothermal therapy.

Designing Anticancer Peptides by Constructive Machine Learning.

Constructive (generative) machine learning enables the automated generation of novel chemical structures without the need for explicit molecular design rules. This study presents the experimental application of such a deep machine learning model to design membranolytic anticancer peptides (ACPs) de novo. A recurrent neural network with long short-term memory cells was trained on α-helical cationic amphipathic peptide sequences and then fine-tuned with 26 known ACPs by transfer learning. This optimized model was used to generate unique and novel amino acid sequences. Twelve of the peptides were synthesized and tested for their activity on MCF7 human breast adenocarcinoma cells and selectivity against human erythrocytes. Ten of these peptides were active against cancer cells. Six of the active peptides killed MCF7 cancer cells without affecting human erythrocytes with at least threefold selectivity. These results advocate constructive machine learning for the automated design of peptides with desired biological activities.

Evaluation of the Cytotoxic and Autophagic Effects of Atorvastatin on MCF-7 Breast Cancer Cells

Background:Recently, cytotoxic effects of statins on breast cancer cells have been reported. However, the mechanism of anti-proliferative effects is currently unknown. Autophagy is non-apoptotic programmed cell death, which is characterized by degradation of cytoplasmic components and as having a role in cancer pathogenesis.Aims:To investigate the anti-proliferative effects of atorvastatin on MCF-7 human breast adenocarcinoma cells with respect to both autophagy and apoptosis.Study Design:Cell culture study.Methods:Cell viability was analyzed using WST-1 cell proliferation assay. Apoptosis was determined by the TUNEL method, whereas autophagy was assessed by Beclin-1 and LC3B immunofluorescence staining. Ultrastructural analysis of cells was performed by electron microscopy.Results:Atorvastatin reduced MCF-7 cell proliferation in a dose- and time-dependent manner inducing TUNEL-, Beclin-1-, and LC3B-positive cells. Moreover, ultrastructural analysis showed apoptotic, autophagic, and necrotic morphological changes in treatment groups. A statistically significant increase in the apoptotic index was detected with higher concentrations of atorvastatin at 24 h and 48 h (p<0.05).Conclusion:The anti-proliferative effects of atorvastatin on breast cancer cells is mediated by the induction of both apoptosis and autophagy which shows statins as a potential treatment option for breast cancer.

Monitoring the Effects of Pharmacological Reagents on Mitochondrial Morphology.

This protocol describes how to apply appropriate pharmacological controls to induce mitochondrial fusion or fission in studies of mitochondria morphology for four different mammalian cell types, HepG2 human liver hepatocellular carcinoma cells, MCF7 human breast adenocarcinoma cells, HEK293 human embryonic kidney cells, and collagen sandwich culture of primary rat hepatocytes. The protocol provides methods of treating cells with these pharmacological controls, staining mitochondria with commercially available MitoTracker Green and TMRE dyes, and imaging the mitochondrial morphology in live cells using a confocal fluorescent microscope. It also describes the cell culture methods needed for this protocol. © 2018 by John Wiley & Sons, Inc.

Structure-Activity Relationships of Nitro-Substituted Aroylhydrazone Iron Chelators with Antioxidant and Antiproliferative Activities.

Aroylhydrazone iron chelators such as salicylaldehyde isonicotinoyl hydrazone (SIH) protect various cells against oxidative injury and display antineoplastic activities. Previous studies have shown that a nitro-substituted hydrazone, namely, NHAPI, displayed markedly improved plasma stability, selective antitumor activity, and moderate antioxidant properties. In this study, we prepared four series of novel NHAPI derivatives and explored their iron chelation activities, anti- or pro-oxidant effects, protection against model oxidative injury in the H9c2 cell line derived from rat embryonic cardiac myoblasts, cytotoxicities to the corresponding noncancerous H9c2 cells, and antiproliferative activities against the MCF-7 human breast adenocarcinoma and HL-60 human promyelocytic leukemia cell lines. Nitro substitution had both negative and positive effects on the examined properties, and we identified new structure-activity relationships. Naphthyl and biphenyl derivatives showed selective antiproliferative action, particularly in the breast adenocarcinoma MCF-7 cell line, where they exceeded the selectivity of the parent compound NHAPI. Of particular interest is a compound prepared from 2-hydroxy-5-methyl-3-nitroacetophenone and biphenyl-4-carbohydrazide, which protected cardiomyoblasts against oxidative injury at 1.8 ± 1.2 μM with 24-fold higher selectivity than SIH. These compounds will serve as leads for further structural optimization and mechanistic studies.

Gadopentatic acid affects in vitro proliferation and doxorubicin response in human breast adenocarcinoma cells.

Contrasting agents (CAs) that are administered to patients during magnetic resonance imaging to facilitate tumor identification are generally considered harmless. However, gadolinium (Gd) based contrast agents can be retained in the body, inflicting specific cell line cytotoxicity. We investigate the effect of Gadopentatic acid (Gd-DTPA) on human breast adenocarcinoma MCF-7 cells. These cells exhibit a toggle switch response: exposure to 0.1 and 1mM concentrations of Gd-DTPA enhances proliferation, which is hindered at a higher 10mM concentration. Proliferation is enhanced when cells transition to 3D morphologies in post confluent conditions. The proliferation dependence on the concentration of CA is absent for Hs 578T and MDA-MB-231 triple negative cell lines. MCF-7 cells reveal a double toggle switch related to the expression of VEGF, which goes through high-low-high downregulation when cells are exposed to 0.1, 1, and 10mM Gd-DTPA, respectively. Finally, doxorubicin drug response is assessed, which also reveals a double toggle switch behavior, where drug cytotoxicity exhibits a nonlinear dependence on the CA concentration. A toggle switch in cell characteristics that are exposed to 1mM of Gd-DTPA amplifies the importance of this threshold, affecting several cell behaviors if surpassed. This work emphasizes the important effects that CAs can have on cells, specifically Gd-DTPA on MCF-7 cells, and the implications for cell growth and drug response during clinical and synthetic biology procedures.

Light-Controlled Simultaneous "On Demand" Release of Cytotoxic Combinations for Bimodal Killing of Cancer Cells.

In this contribution, we report a novel entirely photocontrolled nanoplatform comprising a binary mixture of pluronic copolymers capable of self-assembling into core-shell micelles and co-entrapping two photoactivatable components: a benzoporphyrin photosensitizer for photodynamic therapy (PDT) and coumarin-photocaged chemotherapeutic agent Chlorambucil (CAB). The resulting supramolecular micellar assembly is about 30 nm in diameter with a polydispersity index <0.1, stable for more than 72 h, and exhibits excellent preservation of the photochemical properties of the two photoresponsive components, even though they are confined within the same host nanocarrier. Appropriate regulation of the relative concentrations of these components makes them capable of absorbing visible light in comparable amounts, leading to effective simultaneous photogeneration of singlet oxygen and photo-triggered release of CAB. This "on demand" release of cytotoxic combinations results in amplified anticancer activity against MCF-7 human breast adenocarcinoma cells.

Synthesis of New Benzothiazole Acylhydrazones as Anticancer Agents.

During the last five decades, a large number of BT (Benzothiazole) derivatives formed one of the eligible structures in medicinal chemistry as anticancer agents. Most of the studies reveal that various substitutions at specific positions on BT scaffold modulate the antitumor property. The potential of BTs encouraged us to synthesize a number of new 2-((5-substitutedbenzothiazol-2-yl)thio)-N’-(2-(4-(substitutedphenyl)ethylidene)acetohydrazide derivatives and investigate their probable anticancer activity. 4-Substitued benzaldehyde derivatives (1a–1e) were afforded by the reaction of appropriate secondary amine and 4-fluorobenzaldehyde in DMF. Equimolar quantitates of 5-substitutedbenzothiazole-2-thiol, ethyl chloroacetate and K2CO3 were refluxed in acetone to obtain 2-((5-substitutedbenzothiazol-2-yl)thio)acetate derivatives (2a,2b), which reacted with excess of hydrazine hydrate to get 2-((5-substitutebenzothiazol-2-yl)thio)acetohydrazides (3a,3b). In the last step, 2-((5-substitutedbenzothiazol-2-yl)thio)-N’-(4-substitutedbenzylidene)acetohydrazide derivatives (4a–4j) were synthesized by the reaction of 1a–1e and 3a–3b in EtOH. The anticancer activity of target compounds was evaluated in three steps. First, an MTT test (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) was performed to observe cytotoxic activity of the compounds against carcinogenic C6 (Rat brain glioma cell line), A549 (Human lung adenocarcinoma epithelial cell line), MCF-7 (Human breast adenocarcinoma cell line), and HT-29 (Human colorectal adenocarcinoma cell line) cancer cell lines. Healthy NIH3T3 (Mouse embryo fibroblast cell line) cells were also subjected to MTT assay to determine selectivity of the compounds towards carcinogenic cell lines. Secondly, inhibitory effects of selected compounds 4d, 4e, and 4h on DNA synthesis of C6 cells were investigated. Finally, flow cytometric analysis were performed to identify the death pathway of the carcinogenic cells.

Characterization of a red pigment from Fusarium chlamydosporum exhibiting selective cytotoxicity against human breast cancer MCF-7 cell lines.

This research aims to characterize the pigment produced by isolated fungi and to evaluate its anticancer activities. Pigment-producing fungi was isolated and identified as Fusarium chlamydosporum. The pigment was extracted with chloroform, purified by preparative TLC and characterized by Fourier transmittance infrared, electron spray ionization mass spectroscopy, liquid chromatography mass spectroscopy and nuclear magnetic resonance (NMR) (1 HNMR, 13 C NMR) spectral analysis, which revealed the pigment to be 'long chain hydrocarbons with poly unsaturated groups' (m/z 702). Pigment stability varied with different pH, temperature and sunlight conditions. The pigment-induced cell death in human breast adenocarcinoma cells MCF-7 and showed no significant toxicity in CHOK 1 cells. Lipid peroxidation assay revealed that treatment with pigment was able to reduce the lipid peroxidation caused by H2 O2 in MCF-7 cells. The F. chlamydosporum pigment is a compound of long-chain hydrocarbons with poly unsaturated groups, possessing selective cytotoxicity in MCF-7 cancer cell lines. The pigment can be used as a colouring agent in cosmetics. Its anticancer potential can be used in production of therapeutics in increasing demand cancer research.

Manipulating multifaceted microbubble shell composition to target both TRAIL-sensitive and resistant cells.

This study represents the first attempt to combine surface TRAIL expression and doxorubicin co-encapsulation in a single drug delivery agent in the form of ultrasound-responsive microbubbles that shatter into fragments, or nanoshards, in an ultrasound beam. We compare customized microbubbles of different polymeric shell compositions, and investigate the effect of both shell composition and incorporation of doxorubicin on action against TRAIL-sensitive MDA-MB-231 and TRAIL-resistant MCF7 human breast adenocarcinoma cells. Ligation of TRAIL only significantly impacted MDA-MB-231 cells predominantly by apoptosis, and had minimal effect on MCF12A (normal control) cells. For all shell types, nanoshards had a greater effect (apoptotic death ranging from approximately 25% for 1 wt % LipidPEG to 50% for 100% PLA), reflecting the greater surface area and larger number of particles that ultrasound generates. Encapsulation of doxorubicin generated necrosis in all cell lines, but PEGylation produced less effective necrosis in all cell lines. Co-encapsulation of doxorubicin within the contrast agent shell increased MDA-MB-231 cell death to approximately 40-80%, representing a marked increase over TRAIL alone, reflecting the dramatic effect of shell composition. Additionally, shells that co-encapsulated TRAIL and doxorubicin resulted in approximately 30-60% death in TRAIL-resistant MCF7 human breast adenocarcinoma cells, compared with little apoptotic response in these cells from shells encapsulating TRAIL alone, demonstrating the sensitization effect of the drug. This work has resulted in production of a library of effective ultrasound-triggered, minimally immunogenic, targeted drug delivery agents for potential use in cancer therapy, and represents a promising multifaceted treatment to better serve the population with solid tumors. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1903-1915, 2018.

AJAP1 and Epithelial Cell Adhesion for Epicardial and Coronary Vessel Formation

The coronary vasculature forms to supply oxygen and nutrients to the contractile myocardium when it can no longer be supported by simple diffusion of blood from the cardiac lumen. This is an important step in cardiovascular development that is preceded by formation of the epicardium that contributes epicardial‐derived cells (EPDCs). These EPDCs proceed to form some cells within the nascent coronary vessels. Mice with proepicardium (PE)‐specific deletion of Tbx5 (Tbx5epi−/−) have delayed attachment of the epithelial‐like epicardial cells to the myocardium. This delay precipitates a cascade of deleterious events that impair coronary vessel formation and lead to punctate cardiac hemorrhaging and myocardial hypoxia in Tbx5epi−/− mice. In addition, Tbx5epi−/− mice exhibit reduced cardiac Ajap1 mRNA expression. We previously demonstrated that Ajap1 is expressed within the PE, epicardium and coronary vessels of the developing mouse heart, but little is known about its contribution to cardiovascular morphogenesis other than it is speculated to function as a cell adhesion molecule.Study ObjectiveThe goal of this study was to elucidate contributions of Ajap1 to epithelial cell behaviors that are integral to formation of the epicardium and the subsequent development of the coronary vessels. Based upon our preliminary in vivo data, we hypothesized that the reduction in cardiac Ajap1 expression of our Tbx5epi−/− mice acts as a catalyst to impair epicardium and, subsequently, coronary vessel formation.MethodsTo test this hypothesis, we first analyzed the contribution of AJAP1 to cell behavior in an in vitro system that models mammalian epicardial cells. We utilized the stably transformed MCF7 human breast adenocarcinoma cell line to assess contributions of AJAP1 to epithelial cell function as these cells retain epithelial characteristics in vitro and have endogenous AJAP1 expression. We achieved AJAP1 gene silencing in MCF7s through a small interfering RNAmediated approach that led to a significant reduction in both AJAP1 mRNA and protein expression in these cells. Next, control and AJAP1‐silenced epithelial cells were subjected to cell adhesion assays to assess the ability of these cells to adhere to various basement membrane matrices. Cells were allowed to adhere to these matrices for 1 – 24 hours and adherent cells were quantified. Finally, we analyzed Ajap1 protein expression in embryonic and adult mouse hearts to gauge how its levels change throughout important stages of cardiovascular development.ResultsData from our gene‐silenced epithelial cells revealed a significant difference in cell adhesion abilities between the control and AJAP1‐transfected cells. Cardiac Ajap1 expression changed notably throughout mouse development and after gestation.ConclusionsWe concluded that AJAP1 contributes to the in vitro cell adhesion properties in an epithelial model system of the mammalian epicardium. These data shed light on a mechanism by which AJAP1 contributes to cell adhesion in a mammalian model of epicardial cell behavior. This may be instrumental to understanding coronary vessel formation.Support or Funding InformationSupport: PCOM Center for Chronic Disorders of AgingThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

EFFECT OF CYTOSTATIC AGENTS ON EXPRESSION LEVELS OF HUMAN BETA-DEFENSINS-1-4 IN A431 AND MCF-7 CELL LINES

Expression levels of hBD-1-4 mRNA were assessed using qPCR in human epidermoid carcinoma A431 cells and human breast adenocarcinoma MCF7 cells treated with cisplatin, methotrexate, doxorubicin or vincristine at the IC20 concentrations. The cytostatic agents with different mechanisms of action affected differently expression of hBDs, dependent on the cell line. Mostly, cytostatic agents suppressed significantly expression of hBDs. In contrast, vincristine caused significant up-regulation of hBD-1 (12 fold, p < 0.05) and hBD-4 (2 fold, p < 0.05) in MCF7, and doxorubicin significantly enhanced expression of hBD-3 (2 fold, p < 0.05) and hBD-4 (> 10 fold, p < 0.05) in A431 cells. The results of this pilot study show that expression levels of hBD-1-4 may be altered upon treatment with cytostatic agents depending on nature of cells.