Abstract Despite tremendous advances in oncology, metastatic triple-negative breast cancer remains difficult to treat and manage with established therapies. Here, we show in mice with orthotopic triple-negative breast tumors that alternating (100 kHz), and low intensity (<1 mV/cm) induced electric fields (iEFs) significantly reduced primary tumor growth and distant lung metastases. Non-contact iEF treatment can be delivered safely and non-invasively in vivo via a hollow, rectangular solenoid coil. We discovered that iEF treatment enhances anti-tumor immune responses at both the primary breast and secondary lung sites. In addition, iEF reduces immunosuppressive TME by reducing effector CD8+ T cell exhaustion and the infiltration of immunosuppressive immune cells. Furthermore, iEF treatment reduced lung metastasis by increasing CD8+ T cells and reducing immunosuppressive Gr1+ neutrophils in the lung microenvironment. We also observed that iEFs reduced the metastatic potential of cancer cells by inhibiting epithelial-to-mesenchymal transition. By introducing a non-invasive and non-toxic electrotherapeutic for inhibiting metastatic outgrowth and enhancing anti-tumor immune response in vivo, treatment with iEF technology could add to a paradigm-shifting strategy for cancer therapy.
Objective: To probe the distribution of electrical properties in tumor-bearing human hepatic tissues with metastatic colorectal cancer. Approach: Electrochemical impedance spectroscopy (EIS) and a non-contact electromagnetic probe were used for distinguishing spatial heterogeneities in fresh, unfixed human hepatic tissues ex vivo from patients with metastatic colorectal cancer (CRC). Main results: Point-wise EIS measurements reported over a frequency range of 100 Hz–1 MHz showed that the interface tissue between visible tumor and normal tissue exhibits an electrically different domain (p < 0.05) from both normal tissue (over 100 Hz–100 kHz) and tumor tissue (over 100 Hz–1 MHz). Observations of the microstructure on tumor-bearing hepatic tissue from hematoxylin and eosin stained images and the equivalent circuit modelling were used to validate the impedance measurements and characterize previously unidentified interfacial domain between normal and tumor tissue. Lastly, in a proof of concept study, a new in-house designed non-contact electromagnetic probe, as opposed to the invasive EIS measurements, was demonstrated for distinguishing tumor tissue from the normal tissue in a hepatic tissue specimen from a patient with metastatic CRC. Significance: EIS measurements, correlated with histological observations, show potential for mapping electrical properties in tumor-bearing human hepatic tissue.
The objective of the proposed study is to assess the therapeutic potential of non‐contact inductive E‐fields (iEFs) in inhibiting breast cancer motility. Normal breast ducts are lined with monolayer of epithelial cells that have asymmetric distribution of ion channels resulting in a charge separation between the luminal and the basal sides giving rise to trans‐epithelial potentials (TEP). These TEPs are responsible for endogenous E‐fields that are directed radially from luminal to basal side. Consequently, the sites of invasion in breast tumors are depolarized, which suggest that that cell migration in late‐stage tumors occurs in absence of endogenous E‐fields. Furthermore, breast cancer cells in‐vitro have been shown to migrate towards the positive electrodes under the influence of externally applied direct current electric fields (1–10 V/cm). Therefore, we hypothesize that E‐fields applied in the direction of migrating breast cancer cells potently inhibit cell motility. To test our hypothesis, we used a panel of three breast cell lines, 1) normal MCF10A, 2) MCF10CA1a(MIV) (a malignant variant of MCF10A cells with H‐Ras mutation), and 3) triple negative breast cancer (TNBC) cells MDA‐MB‐231 in conjunction with a custom Bi‐directional Microtrack Assay (BMA). The BMA consists of an array of parallel‐aligned tracks that measure 700 μm in length and with a cross‐section of 20 μm × 20 μm. These microtracks mimic the topological cues encountered by migrating tumor cells that have detached from the primary tumor site during invasion. Inductive Electric Fields (iEFs ~ 60 μV/cm), which mimic the endogenous E‐fields in the breast duct, were applied using a custom‐designed air‐cored Helmholtz coils. iEFs applied anti‐parallel to the direction of migration and in absence of a pro‐migratory epidermal growth factor (EGF) gradient on cancer cells significantly increased migration speeds (Fig A) but had no effect on the control epithelial cells which maintained their non‐migratory phenotype. In presence of a stable EGF gradient, iEFs applied parallel in the direction of migration significantly reduce migration speeds for both the cancerous cell lines whereas it has no effect on migration speeds of MCF10A cells. Actin aggregation at the leading and/or trailing edges is a characteristic of migratory cells and for cancer cells that showed significant speed reduction the intracellular actin was uniformly distributed (Fig B) rather aggregating on the tips indicating a possible mechanism controlled through the EGFR/EGF pathway. Furthermore, we verified using Western Blotting techniques that iEFs significantly reduced phosphorylation of EGFR in EGF‐treated MDA‐MB‐231 cells (Fig C) whereas they downregulated the expression of EGFR in EGF‐treated MCF10CA1a(MIV) cells. For each case, the protein levels had a one‐to‐one correlation with the migration speeds for each cell line. Moreover, we also found that a combinatorial treatment of MK2206 (Akt inhibitor) with iEFs significantly reduced migration speeds of these breast cancer cells (Fig A) below the level of their respective controls. Thus, iEFs selectively hindered cancer cells with no adverse effects on normal epithelial cells, making them a potential candidate for cancer control and intervention. From a therapeutic standpoint, iEFs may help augment current therapeutic approaches to hinder the metastasis of breast cancer and confer survival benefit, including in TNBC, which currently lack any targeted therapies. Support or Funding Information Funding for JWS: American Cancer Society and Institute for Materials Research at The Ohio State University. JWS acknowledge support from Pelotonia. This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .
Abstract Electrochemically generated bactericidal compounds have been shown to eradicate bacterial lawn biofilms through electroceutical treatment. However, the ultrastructure of biofilms exposed to these species has not been studied. Moreover, it is unknown if the efficacy of electroceutical treatment extends to antibiotic-resistant variants that emerge in lawn biofilms after antibiotic treatment. In this report, the efficacy of the in vitro electroceutical treatment of Pseudomonas aeruginosa biofilms is demonstrated both at room temperature and in an incubator, with a ~4 log decrease (p < 0.01) in the biofilm viability observed over the anode at both conditions. The ultrastructure changes in the lawn biofilms imaged using transmission electron microscopy demonstrate significant bacterial cell damage over the anode after 24 h of electroceutical treatment. A mix of both damaged and undamaged cells was observed over the cathode. Finally, both eradication and prevention of the emergence of tobramycin-resistant variants were demonstrated by combining antibiotic treatment with electroceutical treatment on the lawn biofilms.
Tumor treating fields (TTFields)-an intermediate-frequency, electric field therapy-has emerged as a promising alternative therapy for the treatment of solid cancers. Since the first publication describing the anticancer effects of TTFields in 2004 there have been numerous follow-up studies by other groups, either to confirm the efficacy of TTFields or to study the primary mechanism of interaction. The overwhelming conclusion from these in vitro studies is that TTFields reduce the viability of aggressively replicating cell lines. However, there is still speculation as to the primary mechanism for this effect; moreover, observations both in vitro and in vivo of inhibited migration and metastases have been made, which may be unrelated to the originally proposed hypothesis of replication stress. Adding to this, the in vivo environment is much more complex spatially, structurally, and involves intricate networks of cell signaling, all of which could change the efficacy of TTFields in the same way pharmaceutical interventions often struggle transitioning in vivo. Despite this, TTFields have shown promise in clinical practice on multiple cancer types, which begs the question: has the primary mechanism carried over from in vitro to in vivo or are there new mechanisms at play? The goal of this review is to highlight the current proposed mechanism of action of TTFields based primarily on in vitro experiments and animal models, provide a summary of the clinical efficacy of TTFields, and finally, propose future directions of research to identify all possible mechanisms in vivo utilizing novel tumor-on-a-chip platforms.
Background: Induced electric fields (iEFs) control directional breast cancer cell migration. While the connection between migration and metabolism is appreciated in the context of cancer and metastasis, effects of iEFs on metabolic pathways especially as they relate to migration, remain unexplored. Materials and Methods: Quantitative cell migration data in the presence and absence of an epidermal growth factor (EGF) gradient in the microfluidic bidirectional microtrack assay was retrospectively analyzed for additional effects of iEFs on cell motility and directionality. Surrogate markers of oxidative phosphorylation (succinate dehydrogenase [SDH] activity) and glycolysis (lactate dehydrogenase activity) were assessed in MDA-MB-231 breast cancer cells and normal MCF10A mammary epithelial cells exposed to iEFs and EGF. Results: Retrospective analysis of migration results suggests that iEFs increase forward cell migration speeds while extending the time cells spend migrating slowly in the reverse direction or remaining stationary. Furthermore, in the presence of EGF, iEFs differentially altered flux through oxidative phosphorylation in MDA-MB-231 cells and glycolysis in MCF10A cells. Conclusions: iEFs interfere with MDA-MB-231 cell migration, potentially, by altering mitochondrial metabolism, observed as an inhibition of SDH activity in the presence of EGF. The energy intensive process of migration in these highly metastatic breast cancer cells may be hindered by iEFs, thus, through hampering of oxidative phosphorylation.
Approximately 13% by volume of the US Department of Energy (DOE) current backlog of radioactive waste is characterized as high-level waste. Transportation of these wastes requires that the waste package have adequate shielding against gamma radiation. This project investigates the radiation shielding performance of titanium and depleted uranium, which have been proposed for use as gamma shielding materials in DOE transportation packages, by experimentally determining their buildup factors. Buildup factors are important in shield heating and radiation damage calculations. A point-isotropic-source type of buildup factor is the most useful for application in the point-kernal approach utilized in many simple shielding codes. The point-kernal method provides reasonable results for cases in which the shield is made of one solid material and the source can be approximated as one homogeneous material. The point-kernal method has been incorporated into a large number of shielding codes treating three-dimensional geometry using buildup factor data in some form. Buildup factors vary with a number of parameters such as the distance of penetration through the attenuating medium; the geometric configuration of the attenuating medium, source and detector position; the composition of the medium; the detector response function; and the energy and direction of emission of the source photons, ideally taken to be monoenergetic and isotropic.
To overcome the difficulty of assessing oncogene action in human epithelial cell types, such as thyroid, which have limited proliferative potential in culture, we have explored the use of temperature-sensitive (ts) mutants of simian virus 40 (SV40) early region to create conditionally immortalized epithelial cell lines. Normal primary cultures of human thyroid follicular cells were transfected with a plasmid containing the SV40 early region from mutant tsA58. Expanding epithelial colonies were observed after 2 to 3 months, all of which grew to greater than 200 population doublings without crisis. All showed tight temperature dependence for growth. After switch-up to the restrictive temperature (40.5 degrees C), no further increase in cell number was seen after 1 to 2 days. However, DNA synthesis declined much more slowly; the dissociation from cell division led to marked polyploidy. Viability was maintained for up to 2 weeks. Introduction of an inducible mutant ras gene into ts thyroid cells led, as expected, to morphological transformation at the permissive temperature when ras was induced. Interestingly, this was associated with a marked reduction in net growth rate. At the restrictive temperature, induction of mutant ras caused rapid cell death. These results demonstrate the utility of a ts SV40 mutant to permit the study of oncogene action in an otherwise nonproliferative target cell and reveal important differences in the interaction between ras and SV40 T in these epithelial cells compared with previously studied cell types.
Extensive research shows that parental monitoring is a critical factor in child adjustment. Using parent and adolescent reports, this study sought to examine predictors of parental monitoring among an understudied, high-risk sample of runaway adolescents. Parent-reported depressive symptoms, couple (romantic) relationship satisfaction, and adolescent-reported bonding with parents were used as predictors of both child- and parent-reported monitoring. Findings indicated that, among parents, the couple relationship was the primary predictor of monitoring, whereas among adolescents, the parent-child relationship was the primary predictor. Maternal depressive symptoms were unrelated to monitoring. These findings suggest the utility of considering monitoring as an interpersonal phenomenon rather than primarily a parent- or child-driven phenomenon.
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