Electrotransfer of Plasmid DNA Radiosensitizes B16F10 Tumors Through Activation of Immune Response

BackgroundTumor irradiation combined with adjuvant treatments, either vascular targeted or immunomodulatory, is under intense investigation. Gene electrotransfer of therapeutic genes is one of these approaches. The aim of this study was to determine, whether gene electrotransfer of plasmid encoding shRNA for silencing endoglin, with vascular targeted effectiveness, can radiosensitize melanoma B16F10 tumors. Materials and methods The murine melanoma B16F10 tumors, growing on the back of C57Bl/6 mice, were treated by triple gene electrotransfer and irradiation. The antitumor effect was evaluated by determination of tumor growth delay and proportion of tumor free mice. Furthermore, histological analysis of tumors (necrosis, apoptosis, proliferation, vascularization, presence of hypoxia and infiltration of immune cells,) was used to evaluate the therapeutic mechanisms. Results Gene electrotransfer of plasmid silencing endoglin predominantly indicated vascular targeted effects of the therapy, since significant tumor growth delay and 44% of tumor free mice were obtained. In addition, irradiation had minor effects on radioresistant melanoma, with 11% of mice tumor free. The combined treatment resulted in excellent effectiveness with 88% of mice tumor free, with more than half resistant to secondary tumor challenge, which was observed also with the plasmid devoid of the therapeutic gene. Histological analysis of tumors in the combined treatment group, demonstrated similar mode of action of the gene electrotransfer of plasmid encoding shRNA for silencing endoglin and devoid of it, both through the induction of an immune response. Conclusions The results of this study indicate that irradiation can in radioresistant melanoma tumors, by release of tumor associated antigens, serve as activator of the immune response, besides directly affecting tumor cells and vasculature. The primed antitumor immune response can be further boosted by gene electrotransfer of plasmid, regardless of presence of the therapeutic gene, which was confirmed by the high radiosensitization, resulting in prolonged tumor growth delay and 89% of tumor free mice that were up to 63% resistant to secondary challenge of tumor. In addition, gene electrotransfer of therapeutic plasmid for silencing endoglin has also a direct effect on tumor vasculature and tumors cells; however in combination with radiotherapy this effect was masked by pronounced immune response

Electric Field Enhanced Plasmid Delivery to Liver Hepatocellular Carcinomas

Electric field enhanced molecular delivery for cancer research and treatment is a new technology that has demonstrated its effectiveness in clinical trials using bleomycin or cisplatin (Heller, R., Gilbert, R., Jaroszeski, M. J. Clinical applications of electrochemotherapy, Advanced Drug Delivery Reviews 35,119-129, 1999), as chemotherapeutic agents. The technology is being investigated in research applications for applicability as a method to enhance gene expression in a target tumor. Success is predicated on an appropriate effective electric field mediated delivery protocol that triggers significant appropriate gene expression duration and levels. An electric field mediated delivery protocol includes a set of conditions associated with the electric field, the electroporation signature, as well as parameters associated with the plasmid and the electric field applicator. Manipulation of the electrical parameters within the electroporation signature generates different gene expression levels in liver hepatocellular carcinomas. Statistically significant gene expression levels were obtained that differed by an order of magnitude when two different electric field strength and duration conditions were employed

The Distributed University for Sustainable Higher Education

This book is open access and discusses the re-imagining of the higher education sector. It exposes problems that relate to the way that universities have become over-managed business enterprises which may not reflect societal, national, or global educational needs. From there, it proposes some solutions, including three innovative programs, that make universities more responsive to needs, as well as reduce their impact on the environment. The central idea of this book is developing the ‘Distributed University,’ which distributes education to where it is needed, reducing local and global inequalities in access, and emphasizing local relevance in place of large centralized campuses, with a low impact on the environment. It emphasizes the distribution of trust in place of managerialism and collaboration in place of competition. By focusing on distributing education online, this book discusses how the higher education sector can be set up to adapt to the changes in the ways we work and learn today, and which will be required to adapt to and take advantage of the Fourth Industrial Revolution

Tidal Effects on the Habitability of Exoplanets: The Case of GJ 581 d

Tides may be crucial to the habitability of exoplanets. If such planets form around low-mass stars, then those in the circumstellar habitable zone will be close enough to their host stars to experience strong tidal forces. Tides may result in orbital decay and circularization, evolution toward zero obliquity, a fixed rotation rate (not necessarily synchronous), and substantial internal heating. Due to tidal effects, the range of habitable orbital locations may be quite different from that defined by the traditional concept of a habitable zone (HZ) based on stellar insolation, atmospheric effects, and liquid water on a planet's surface. Tidal heating may make locations within the traditional HZ too hot, while planets outside the traditional zone could be rendered quite habitable due to tides. Here we consider these effects on the exoplanet GJ 581 d.Comment: 2 pages, 1 figure

Tidal Constraints on Planetary Habitability

We review how tides may impact the habitability of terrestrial-like planets. If such planets form around low-mass stars, then planets in the circumstellar habitable zone will be close enough to their host stars to experience strong tidal forces. We discuss 1) decay of semi-major axis, 2) circularization of eccentric orbits, 3) evolution toward zero obliquity, 4) fixed rotation rates (not necessarily synchronous), and 5) internal heating. We briefly describe these effects using the example of a 0.25 solar mass star with a 10 Earth-mass companion. We suggest that the concept of a habitable zone should be modified to include the effects of tides.Comment: 6 pages, 3 figures. Proceedings submitted to "Pathways Towards Habitable Planets" Symposium (eds.: D. Gelino, V. Coude du Foresto, I. Ribas

The Use of an in vitro 3D Melanoma Model to Predict in vivo Plasmid Transfection Using Electroporation

A large-scale in vitro 3D tumor model was generated to evaluate gene delivery procedures in vivo. This 3D tumor model consists of a tissue-like spheroid that provides a micro-environment supportive of melanoma proliferation, allowing cells to behave similarly to cells in vivo. This functional spheroid measures approximately 1 cm in diameter and can be used to effectively evaluate plasmid transfection when testing various electroporation (EP) electrode applicators. In this study, we identified EP conditions that efficiently transfect green fluorescent protein (GFP) and interleukin 15 (IL-15) plasmids into tumor cells residing in the 3D construct. We found that plasmids delivered using a 6-plate electrode applying 6 pulses with nominal electric field strength of 500 V/cm and pulse-length of 20 ms produced significant increase of GFP (7.3-fold) and IL-15 (3.0-fold) expression compared to controls. This in vitro 3D model demonstrates the predictability of cellular response toward delivery techniques, limits the numbers of animals employed for transfection studies, and may facilitate future developments of clinical trials for cancer therapies in vivo

Experience with a "social model" of capacity building: the Peoples-uni

<p>Abstract</p> <p>Background</p> <p>Taking advantage of societal trends involving the "third sector", a social model of philanthropy and the open-source software and educational resource movements, provides the opportunity for online education for capacity building at low cost. The Peoples Open Access Education Initiative, Peoples-uni, aims to help build public health capacity in this way, and this paper describes its evolution.</p> <p>Methods</p> <p>The development of the Peoples-uni has involved the creation of an administrative infrastructure, calls for and identification of volunteers, development of both the information and communications technology infrastructure and course content, and identification of students and course delivery to them. A pilot course module was offered for delivery.</p> <p>Results and Discussion</p> <p>Volunteers have been prepared to become involved in the administrative structures, as trustees, members of advisory and quality assurance and educational oversight groups. More than 100 people have offered to be involved as course developers or as facilitators for course delivery, and to date 46 of these, from 13 countries, have been actively involved. Volunteer experts in information and communications technology have extended open-source course-delivery mechanisms. Following an encouraging pilot course module, 117 students from 23 countries have enrolled in the first set of six course modules. Although the business model is not fully developed, this approach allows current module delivery at USD 50 each, to be more affordable to the target audience than traditional university-based education.</p> <p>Conclusion</p> <p>A social model of capacity building in public health has been started and has been able to attract volunteers and students from a wide range of countries. The costs are likely to be low enough to allow this method to make a substantial contribution to capacity building in low-income settings.</p

The Distributed University for Sustainable Higher Education

This book is open access and discusses the re-imagining of the higher education sector. It exposes problems that relate to the way that universities have become over-managed business enterprises which may not reflect societal, national, or global educational needs. From there, it proposes some solutions, including three innovative programs, that make universities more responsive to needs, as well as reduce their impact on the environment. The central idea of this book is developing the ‘Distributed University,’ which distributes education to where it is needed, reducing local and global inequalities in access, and emphasizing local relevance in place of large centralized campuses, with a low impact on the environment. It emphasizes the distribution of trust in place of managerialism and collaboration in place of competition. By focusing on distributing education online, this book discusses how the higher education sector can be set up to adapt to the changes in the ways we work and learn today, and which will be required to adapt to and take advantage of the Fourth Industrial Revolution

IL-12 Plasmid Delivery by in Vivo Electroporation for the Successful Treatment of Established Subcutaneous B16.F10 Melanoma

Interleukin-12 (IL-12) has been used in numerous immunotherapy protocols against melanoma. However, delivery of IL-12 in the form of recombinant protein can result in severe toxicity, and gene therapy has had limited success against B16.F10 murine melanoma. The purpose of this study was to examine the effectiveness of in vivo electroporation for the delivery of plasmid DNA encoding IL-12 as an antitumor agent against B16.F10 melanoma. We treated mice bearing established B16.F10 melanoma tumors with intratumoral (i.t.) or intramuscular (i.m.) injections of a plasmid encoding IL-12, followed by in vivo electroporation. For i.t. treatments, we used an applicator containing six penetrating electrodes to deliver 1500-V/cm, 100-micros pulses. We administered i.m. pulses with an applicator containing four penetrating electrodes delivering 100-V/cm, 20-ms pulses. The i.t. treatment resulted in the cure of 47% of tumor-bearing mice, and 70% of cured mice were resistant to challenge with B16.F10 cells. The i.m. treatment did not result in tumor regression. We found that i.t. treatment resulted in increased levels of IL-12 and interferon-γ (IFN-γ) within the tumors, the influx of lymphocytes into the tumors, and reduction in vascularity. Neither i.m. nor i.t. treatment was successful against B16.F10 tumors in a nude mouse model, supporting a role for T cells in regression of this tumor model