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Posted 5/2/13

Dr. Ichiro Nakano, M.D., Ph.D
Associate Professor
Dardinger Laboratory for Neurosciences
Department of Neurological Surgery
The Ohio State University     
385-A Wiseman Hall       
400 W. 12th Ave.             
Columbus, OH  43210    
Phone:  (614) 292-0358            
Fax:  (614)688-4882           
Email:  Ichiro.Nakano@osumc.edu 

We identified 2 mutually-exclusive cancer stem cell subtypes in brain tumors.
A hallmark of malignant high-grade gliomas (HGGs), including anaplastic glioma and glioblastoma multiforme (GBM), is their intrinsic resistance to current therapies that leads to extremely poor clinical outcomes. Even patients with well-demarcated tumors in non-eloquent areas that allow maximal gross total removal at surgery and respond well to initial combined therapies inevitably develop subsequent tumor recurrence with minimal survival. Therefore, there is an urgent need to better understand the underlying mechanisms of such malignancy, thereby providing an opportunity to develop novel therapies and approaches to treat patients with aggressive HGGs. Recent genome-wide transcriptome analyses suggest that HGGs can be divided into four clinically relevant subtypes: proneural (PN), neural, classic and mesenchymal (MES) HGGs. Distinct signals are activated in these individual HGG subtypes that may account for the observed differential responses to therapy. Therefore, therapeutic strategies for HGGs should be designed based on tumor subtype, instead of applying them to all patients with HGGs.

HGG tumors are composed of heterogeneous tumor cell populations that include tumor cells with stem cell properties termed glioma initiating/propagating cells or glioma stem cells (GSCs). The unique properties of GSCs are considered to contribute to the therapeutic resistance of HGG. Thus, understanding and targeting tumor-propagating GSCs could be beneficial in developing effective strategies that overcome therapeutic resistance of HGG. Given the distinct gene sets and signaling pathways that are differentially expressed in each subtype of HGG, GSCs in each subtype may also harbor distinct and dysregulated pathways that render their unique phenotypes in tumor growth, progression and resistance to therapy. In one of our recent studies, we identified two mutually exclusive GSCs in HGGs (PN and MES) with striking phenotypic and genetic differences including aberrantly high expression of aldehyde dehydrogenase1A3 (ALDH1A3) in MES GSCs.

Distinct Tumor Metabolism of these 2 cancer stem cell subtypes.
In this study, we demonstrated that irradiation induces a change of expression of the PN and MES representative markers indicating a transformation of PN to MES GSCs (PN-to-MES transformation; PMT) and ALDH1A3 is required for this transformation. Collectively, our data provide a set of evidence suggestive of a novel signaling mechanism underlying the transformation of PN GSCs to MES-like cells and maintenance of stemness of MES GSCs. Future characterization of the ALDH1-mediated pathways could potentially elucidate novel molecular mechanisms of GSC maintenance and/or propagation, and eventually lead to development of novel and effective molecularly targeted therapies for HGGs.

PNAS-2013-Mao-1221478110.pdfPNAS-2013-Mao-1221478110.pdf

Figure 1. The patient-derived glioma stem cells isolated at the OSU Neurosurgery recapitulate the original tumors in mouse brains.

Figure 1.JPG

Figure 2. Two distinct glioma stem cells (A). Mesenchymal, but not Proneural, glioma stem cells form highly vascularized GBM in mouse brains (B). Mesenchymal, but not Proneural glioma stem cells are highly aggressive in mouse brains (C). Elevated glycolysis in Mesenchymal glioma stem cells (D).

Figure 2.JPG

Figure 3. Mesenchymal glioma stem cells are resistant to irradiation (A). Irradiation-induced conversion of Proneural glioma stem cells to Mesenchymal glioma stem cells (Proneural-to-Mesenchymal Transformation; PMT) (B). Blockage of PMT by ALDH1A3 inhibition (C).

Figure 3.JPG
 

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Posted 3/29/13

John J. Lannutti, Ph.D, Professor.
Department of Materials Science and Engineering, Department of Biomedical Engineering
The Ohio State University
448 Fontana Labs
116 W. 19th Ave.
Columbus, OH 43210
Phone: (614) 292-3926
Fax: (614) 292-1537
Email:  Lannutti.1@osu.edu
 
“Vascular Wall Engineering” Via Femtosecond Laser Ablation
Over 80 million people in the United States suffer from coronary vascular disease; within this group, more than 176,000 patients annually undergo coronary artery bypass grafting. The lack of healthy auto-grafts, especially in the elderly, is a major obstacle to successful treatment. Synthetic vascular grafts made of non-degradable polymers, such as polyethylene terephthalate (Dacron) or expanded polytetrafluoroethylene (ePTFE), are commonly used for bypass grafting. Unfortunately, in vivo small (<6 mm) diameter synthetic grafts often exhibit compliance mismatch, rapid plaque formation, and occlusion of the lumen.  A key component of strategies designed to address this is promoting proper initial cell organization and orientation within the vessel, especially in the tunica media (middle layer). Current methods can require up to 5 months from initial cell culture to final vessel formation that is incompatible with many clinical applications.
 
Clearly, for tissue-engineered grafts to reach their full potential, three-dimensional (3D) cellular micro-integration will be necessary. By working with femtosecond laser ablation, we are able to produce microchannels within the walls of electrospun polycaprolactone (PCL) scaffolds capable of vascular application. These microchannels potentially provide spatially controlled cell distributions approaching those observed in vivo. The ability of such laser-ablated microchannels to direct cell seeding was evaluated. The dimensions chosen were 100 μm wide, 100 μm deep and 10 mm long. Femtosecond laser ablation successfully produced these microchannels in the scaffolds without substantially altering the ~900 nm diameter fibers. Flow within these microchannels was studied by injecting fluorescent polystyrene bead solutions. Direct measurement of bead motion yielded an inlet velocity of 2.78 cm s−1. This was used for modeling two-dimensional (2D) flow using computational fluid dynamics to estimate flow profiles within the microchannel.
 
Successful demonstrations of bead flow were followed by seeding of 500,000 human coronary artery smooth muscle cells (HCASMCs) in proliferative medium at a rate of ~500 μL/min. Confocal microscopy and scanning electron microscopy confirmed that the HCASMCs were seeded down the full 10-mm length of the microchannel and stayed within its boundaries. Both nuclei and F-actin were observed within the seeded cells. The presence of F-actin filaments shows that the cells were adhered strongly to the scaffold and remained viable throughout the culture. The concept of “vascular wall engineering” producing intricate cell seeding through microchannels produced via femtosecond laser ablation was validated.  This work was created via a collaboration with Drs. Heather Powell and Dave Farson in the Departments of Materials Science and Engineering and Biomedical Engineering at OSU.




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Posted 3/25/13

Heather M. Powell, Ph.D, Assistant Professor.
Department of Materials Science and Engineering, Department of Biomedical Engineering
The Ohio State University
243 Fontana Labs
116 W. 19th Ave.
Columbus, OH 43210
Phone: (614) 247-8673
Fax: (614) 292-1537
Email: powell.299@osu.edu

Plant-derived Human Collagen Scaffolds for Skin Tissue Engineering
Prompt closure of wounds in children suffering massive (>70% total body surface) burn injuries is critical to prevention of infection and sepsis. Tissue engineered skin offers promise as an adjuvant burn therapy when autograft is not readily available and numerous tissue engineered skin replacements have been created. Tissue scaffolds for skin regeneration are commonly formed using proteins extracted from human and animal tissues. Although the engineered skin fabricated using collagen obtained from bovine and human sources has proved useful for the treatment of acute and chronic wounds, there are risks associated with the use of these materials including human allergic reactions and pathogenic contamination. With the growing use of bovine collagen implants, questions have been raised regarding their immunogenicity in humans. Approximately 3% of the population is allergic to bovine collagen with severe hypersensitivity reported in some cases. Additionally, the Centers for Disease Control and Prevention and the FDA both concluded that a significant statistical association exists between bovine collagen used in dermal fillers and dermatomyositis. Autologous and cadaveric human collagens have a lower risk of hypersensitivity but possess the risk of disease transmission.
 
To overcome these limitations, recombinant human proteins have been engineered using bacteria or plant material. These bacterial or plant-derived human proteins are an alternate source of these materials without the risk of disease transmission or concerns regarding variability. Dr. Heather Powell’s group in the Departments of Materials Science and Engineering and Biomedical Engineering has designed scaffolds for skin tissue engineered from plant-derived human collagen type I. These scaffolds could be formed into both reticulated sponge and nanofiber scaffold with controlled architectures and supported cell viability and adhesion to a greater extent than commercially available collagen-based scaffolds. The use of plant-derived human collagen significantly decreased scaffold processing time and sped epidermal differentiation compared to bovine collagen controls. Additionally, IL-1 beta production was significantly lower when activated THP-1 macrophages where exposed to the plant-derived human collagen scaffolds compared to bovine collagen controls. Plant-derived human collagen provides a novel source of raw material for tissue engineering with low risk of allergic response or disease transmission and an increased ease of processing. This work is in collaboration with Dr. Shani Shilo and Dr. Oded Shoseyov at ColPlant Ltd. and Dr. Sashwati Roy in the Department of Surgery at OSU.



 

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Current Discoveries James Jim Lee Lipid Nanoparticles 2 4 13.jpg 

Posted: 2/4/13 
L. James Lee, Ph.D, Professor.
Helen C. Kurtz Chair, Department of Chemical and Biomolecular Engineering
Director, NSF Center for Affordable Nanoengineering of Polymeric Biomedical Devices
The Ohio State University
1012 Smith Labs
174 W. 18th Ave.
Columbus, OH 43210
Phone: (614) 292-2408
Fax: (614) 292-3769
 
Lipid nanoparticles for hepatic delivery of small interfering RNA
 
Hepatocellular carcinoma (HCC) is the sixth most common cancer worldwide and the third leading cause of cancer deaths, with 500,000 new cases diagnosed yearly. Major factors contributing to the increase in HCC-related deaths are late diagnosis and the lack of effective therapeutic strategies. While surgical removal of tumor tissues is an effective approach to protect relatively healthy liver tissue, it is only applicable to a small subset of HCC patients with specific pathological conditions, such as confined tumor mass without portal hypertension. Therefore, there is an urgent need to develop novel therapeutic strategies to treat this deadly disease.
Small interfering RNAs (siRNAs) can silence expressions of disease-causing genes in a sequence-specific manner. They hold great promise for therapeutic applications in a wide spectrum of diseases. However, inefficient cellular uptake and poor stability of free siRNAs have limited their clinical applications. The challenges for developing siRNA-based therapeutics include achieving efficient cellular uptake, tissue-specific delivery and minimizing systemic toxicity and off target effects.
 
To overcome this problem, Dr. L. James Lee’s group in Department of Chemical and Biomolecular Engineering and NSF Center for Affordable Nanoengineering of Polymeric Biomedical Devices at The Ohio State University  designed and synthesized novel lipid nanoparticles (LNPs) for siRNA delivery based on cationic lipids with multiple tertiary amines and hydrophobic linoleyl chains. These LNPs were found to have exceptionally high siRNA transfection efficacy in liver and liver tumor. The most efficient cationic lipid-like material possesses four tertiary amines at head group and triple hydrophobic linoleyl chains and termed TRENL3. Adding unsaturated fatty acids such as linoleic acid (LA) into the lipid base nanoparticles formulation further enhanced the potent siRNA delivery efficacy both in vitro and in vivo. The enhanced pH-sensitive, ionizability and the cellular uptake via macropinocytosis (a more efficient endocytosis pathway) are believed to be the main reasons of the observed high efficacy of the TRENL3–LA-based LNPs. The association with certain serum proteins such as ApoE could partially explain why the TRENL3–LA-based LNPs showed the predominant uptake by liver and liver tumor. LNPs may serve as a valuable nanocarrier for in vivo targeting and siRNA therapeutic use in liver related diseases including hepatocellular carcinoma. This work is a collaboration with Dr. Sam Jacob and Dr. Kalpana Ghoshal in Medicine and Dr. Robert Lee in Pharmacy.
 
http://www.ncbi.nlm.nih.gov/pubmed/22652024
 
Figures:
1.      Chemical structures of three cationic lipid-like materials.
 
Jim Lee Current Discoveries Image 1.jpg  
2.      In vitro evaluation of siRNA-LNPs containing TRENL based nanoparticles
(A)  Luciferase gene silencing by siRNA encapsulated in various TRENL based formulations.
(B)  Enhanced in vitro delivery efficiency by including unsaturated fatty acid in LNPs. 
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3.    In vivo biodistribution study of LNP mediated systemic delivery of siRNA
(A,B) Tissue distribution of Cy5-ODN containing LNP with TRENL3 and LA.
(C) A representative IVIS fluorescence image of tissues from a DEN induced mouse treated by Cy5-ODN (2.5 mg/kg) in LNP with TRENL3 and LA.
(D) Confocal images of liver and liver tumor sections from the DEN mouse treated by TRENL3–LA-based LNP carrying Cy3-siRNA. 
Jim Lee Current Discoveries Image 3.jpg
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Posted: 7/30/12
Jianjun Guan, Ph.D.
Assistant Professor
Department of Materials Science and Engineering
The Ohio State University
494 Watts Hall
2041 College Road
Columbus, OH 43210
Phone: 614-292-9743
Fax: 614-292-1537

 

An oxygen release system to augment cardiac progenitor cell survival and differentiation under hypoxic condition.
 
Myocardial infarction (MI) affects more than 8 million people in the United States. MI causes extensive death of heart cells and partial loss of heart function. Stem cell therapy has been considered as a potential approach to regenerate lost heart tissue and restore heart function. However, current stem cell therapy has an extremely low efficacy. Various studies have shown that most of the injected cells died few weeks after injection, and few of the surviving cells differentiated into cardiac cells for regeneration. Such low efficacy significantly limits the application of stem cell therapy in clinics.

 

Hypoxia in infarcted hearts has been identified as one of the major causes. Many approaches have been used to address the cell survival issue under hypoxic condition, such as transfecting cells with pro-survival gene Akt and hyperbaric oxygenation of cells. However, these approaches may generate new concerns. Gene transfection by virus brings up safety concerns, while hyperbaric oxygenation may generate reactive oxygen species that damage cells. In addition, hyperbaric oxygenation may not allow cells to survive under hypoxic condition for a couple of weeks, a period usually needed for the establishment of angiogenesis.

 

To overcome current limits, Dr. Jianjun Guan’s group in Department of Materials Science and Engineering at The Ohio State University created a novel oxygen-releasing system capable of sustainedly supplying oxygen to stem cells. The oxygen-releasing system consisted of hydrogen peroxide (H2O2)-releasing microspheres, catalase, and an injectable, thermosensitive hydrogel. The microspheres were based on degradable poly(lactide-co-glycolide) (PLGA), and a complex of H2O2 and poly(2-vinlypyrridione) (PVP). The oxygen was generated after the H2O2 released from microspheres was decomposed by catalase. The hydrogel was designed to improve the retention of microspheres and stem cells in the beating heart during myocardial injection. The oxygen-releasing system was capable of sustainedly releasing oxygen for at least two weeks. Under hypoxic condition mimicking that of the infarcted hearts, cardiac progenitor cells experienced massive cell death. Introduction of oxygen release significantly augmented cell survival; no cell death was found after seven days of culture, and cells even grew after seven days. Under hypoxic condition, cardiac differentiation of cardiac progenitor cells was completely silenced. However, introduction of oxygen release restored the differentiation. These results demonstrate that the developed oxygen-releasing system has great potential to improve the efficacy of cardiac stem cell therapy.

http://www.ncbi.nlm.nih.gov/pubmed/22656447

 
Figures:
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