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1.  Metallofullerene-Nanoplatform-Delivered Interstitial Brachytherapy Improved Survival in a Murine Model of Glioblastoma Multiforme 
Bioconjugate chemistry  2012;23(9):1873-1880.
Fullerenes are used across scientific disciplines because of their diverse properties gained by altering encapsulated or surface bound components. In this study, the recently developed theranostic agent based on a radiolabeled functionalized metallofullerene (177Lu-DOTA-f-Gd3N@C80) was synthesized with high radiochemical yield and purity. The efficacy of this agent was demonstrated in two orthotopic xenograft brain tumor models of glioblastoma multiforme (GBM). A dose-dependent improvement in survival was also shown. The in vivo stability of the agent was verified through dual label measurements of biological elimination from the tumor. Overall, these results provide evidence that nanomaterial platforms can be used to deliver effective interstitial brachytherapy.
doi:10.1021/bc300206q
PMCID: PMC3448337  PMID: 22881865
fullerene; nanomedicine; brachytherapy; glioblastoma; metallofullerene
2.  The Influence of Hypoxia and pH on Bioluminescence Imaging of Luciferase-Transfected Tumor Cells and Xenografts 
Bioluminescence imaging (BLI) is a relatively new noninvasive technology used for quantitative assessment of tumor growth and therapeutic effect in living animal models. BLI involves the generation of light by luciferase-expressing cells following administration of the substrate luciferin in the presence of oxygen and ATP. In the present study, the effects of hypoxia, hypoperfusion, and pH on BLI signal (BLS) intensity were evaluated in vitro using cultured cells and in vivo using a xenograft model in nude mice. The intensity of the BLS was significantly reduced in the presence of acute and chronic hypoxia. Changes in cell density, viability, and pH also affected BLS. Although BLI is a convenient non-invasive tool for tumor assessment, these factors should be considered when interpreting BLS intensity, especially in solid tumors that could be hypoxic due to rapid growth, inadequate blood supply, and/or treatment.
doi:10.1155/2013/287697
PMCID: PMC3723249  PMID: 23936647
3.  The development of MDA-7/IL-24 as a cancer therapeutic 
Pharmacology & therapeutics  2010;128(2):375-384.
The cytokine melanoma differentiation associated gene 7 (mda-7) was identified by subtractive hybridization as a protein whose expression increased during the induction of terminal differentiation, and that was either not expressed or was present at low levels in tumor cells compared to non-transformed cells. Based on conserved structure, chromosomal location and cytokine-like properties, MDA-7, was classified as a member of the interleukin (IL)-10 gene family and designated as MDA-7/IL-24. Multiple studies have demonstrated that expression of MDA-7/IL-24 in a wide variety of tumor cell types, but not in corresponding equivalent non-transformed cells, causes their growth arrest and rapid cell death. In addition, MDA-7/IL-24 has been noted to radiosensitize tumor cells which in part is due to the generation of reactive oxygen species (ROS) and ceramide that cause endoplasmic reticulum stress and suppress protein translation. Phase I clinical trial data has shown that a recombinant adenovirus expressing MDA-7/IL-24 (Ad.mda-7 (INGN-241)) was safe and had measurable tumoricidal effects in over 40% of patients, strongly arguing that MDA-7/IL-24 could have significant therapeutic value. This review describes what is presently known about the impact of MDA-7/IL-24 on tumor cell biology and its potential therapeutic applications.
doi:10.1016/j.pharmthera.2010.08.001
PMCID: PMC2947573  PMID: 20732354
MDA-7; IL-24; Apoptosis; Autophagy; Ceramide; ROS; Ca2+; Clinical trial; Signal transduction; PERK; ER stress; MCL-1
4.  MDA-7/IL-24 as a cancer therapeutic: from bench to bedside 
Anti-cancer drugs  2010;21(8):725-731.
The novel cytokine melanoma differentiation associated gene-7 (mda-7) was identified by subtractive hybridization in the mid-1990s as a protein whose expression increased during the induction of terminal differentiation, and that was either not expressed or was present at low levels in tumor cells compared to non-transformed cells. Based on conserved structure, chromosomal location and cytokine-like properties, MDA-7, has now been classified as a member of the expanding interleukin (IL)-10 gene family and designated as MDA-7/IL-24. Multiple studies have demonstrated that expression of MDA-7/IL-24 in a wide variety of tumor cell types, but not in corresponding equivalent non-transformed cells, causes their growth arrest and ultimately cell death. In addition, MDA-7/IL-24 has been noted to be a radiosensitizing cytokine, which in part is due to the generation of reactive oxygen species (ROS) and ceramide that cause endoplasmic reticulum stress. Phase I clinical trial data has shown that a recombinant adenovirus expressing MDA-7/IL-24 (Ad.mda-7 (INGN-241)) was safe and had measurable tumoricidal effects in over 40% of patients, which strongly argues that MDA-7/IL-24 may have significant therapeutic value. This review describes what is known about the impact of MDA-7/IL-24 on tumor cell biology and its potential therapeutic applications.
doi:10.1097/CAD.0b013e32833cfbe1
PMCID: PMC2915543  PMID: 20613485
MDA-7: melanoma differentiation associated gene 7
5.  PERK–Dependent Regulation of Ceramide Synthase 6 and Thioredoxin Play a Key Role in mda-7/IL-24–Induced Killing of Primary Human Glioblastoma Multiforme Cells 
Cancer research  2010;70(3):1120-1129.
Melanoma differentiation associated gene-7(mda-7) encodes IL-24, a cytokine that can selectively trigger apoptosis in transformed cells. Recombinant mda-7 adenovirus (Ad.mda-7) effectively kills glioma cells, offering a novel gene therapy strategy to address deadly brain tumors. In this study, we defined the proximal mechanisms by which Ad-mda-7 kills glioma cells. Key factors implicated included activation of the endoplasmic reticulum stress kinase protein kinase R–like endoplasmic reticulum kinase (PERK), Ca++ elevation, ceramide generation and reactive oxygen species (ROS) production. PERK inhibition blocked ceramide or dihydroceramide generation, which were critical for Ca++ induction and subsequent ROS formation. Activation of autophagy and cell death relied upon ROS formation, the inhibition of which ablated Ad.mda-7–killing activity. In contrast, inhibiting TRX induced by Ad.MDA-7 enhanced tumor cytotoxicity and improved animal survival in an orthotopic tumor model. Our findings indicate that mda-7/IL-24 induces an endoplasmic reticulum stress response that triggers production of ceramide, Ca2+, and ROS, which in turn promote glioma cell autophagy and cell death.
doi:10.1158/0008-5472.CAN-09-4043
PMCID: PMC2890071  PMID: 20103619
6.  Primary brain T-cell lymphoma of the lymphoblastic type presenting as altered mental status 
Acta Neurochirurgica  2009;152(1):163-168.
The authors present a case of a 56-year-old man with altered mental status. Magnetic resonance imaging (MRI) of the brain revealed non-enhancing abnormalities on T2 and FLAIR imaging in the brainstem, cerebellum, and cerebrum. Immunohistochemisty demonstrated precursor T-cell lymphoblastic lymphoma. After treatment with methotrexate, he improved clinically without focal sensorimotor deficits and with improving orientation. MRI showed almost complete resolution of brainstem and cerebral lesions. To the authors’ knowledge, there are only five previous reports of primary central nervous system T-cell lymphoblastic lymphoma. Since treatable, it deserves consideration in patients with altered mental status and imaging abnormalities that include diffuse, non-enhancing changes with increased signal on T2-weighted images.
doi:10.1007/s00701-009-0433-z
PMCID: PMC2801848  PMID: 19578806
T-cell lymphoblastic lymphoma; Primary CNS lymphoma; Brain tumor; Altered mental status; Chemotherapy
7.  A Biobehavioral Perspective on Depressive Symptoms in Patients with a Cerebral Astrocytoma 
Over 51,000 individuals are diagnosed with a primary brain tumor in the United States each year, and for those with the most common type of malignant tumor, an astrocytoma, almost 75% will die within five years of diagnosis. While surgery, radiation, and chemotherapy have improved length of survival, mortality remains high, which underscores the need to understand how other factors affect the disease trajectory. Several recent studies have shown that depressive symptoms are independently associated with reduced quality of life and survival time after controlling for medial variables in patients with an astrocytoma. Thus, depressive symptoms represent a significant risk factor for adverse outcomes in this patient population.
A growing body of evidence indicates that depressive symptoms are linked to underlying biological phenomena, particularly inflammatory activation modulated through increased peripheral levels of proinflammatory cytokines. Recent research has shown that neoplastic astrocytes respond to elevated proinflammatory cytokine levels by secreting immune mediators within the central nervous system, including cytokines and glial fibrillary acidic protein (GFAP) that promote astrogliosis and angiogenesis, and may increase tumor growth and metastasis. However, because these biological factors have not as yet been measured in conjunction with depressive symptoms in these patients, little is known about the interactions that potentially influence the treatment trajectory.
In order to guide future research and provide a deeper understanding of the factors that may influence depressive symptoms and length of survival in patients with an astrocytoma, a review of the literature was undertaken. Publications over the past ten years were analyzed to examine the theoretical models and measures of depressive symptoms used in previous research. While numerous studies have documented the relationship between depression and reduced length of survival, there were several methodological concerns identified and there were no studies which included biological variables. Yet, research in the basic sciences provides compelling evidence of specific neuroendocrine-immune interactions orchestrated by astrocytes that can cause depressive symptoms and alter the tumor microenvironment so that standard treatments are not as effective. These findings support the need for clinically-based research so that we can begin to understand the potentially modifiable biobehavioral mechanisms underlying depressive symptoms in patients with an astrocytoma. Grounded in the biobehavioral research paradigm of psychoneuroimmunology, a novel research program is presented that may provide a new level of understanding regarding the high prevalence of depressive symptoms in patients with an astrocytoma and lead to new treatment strategies, with possible implications for improved symptom management and quality of life in patients with brain tumors.
PMCID: PMC3732744  PMID: 21338041
8.  Induction of membrane-type-1 matrix metalloproteinase by epidermal growth factor-mediated signaling in gliomas1 
Neuro-Oncology  2004;6(3):188-199.
Increased expression of membrane-type matrix metalloproteinases (MT-MMPs) has previously been reported to correlate with increasing grade of malignancy in gliomas, a relationship shared with alterations in epidermal growth factor receptor (EGFR) signaling. To investigate the possibility of a causative role for EGFR signaling in increasing MT-MMP expression and subsequent peritumoral proteolysis, we characterized glioma cell lines for expression of MT1-MMP, MT2-MMP, MT3-MMP, and MT5-MMP by Western blotting and by quantitative real-time polymerase chain reaction analysis, and for MMP-2 activity following epidermal growth factor (EGF) stimulation. EGF stimulation of glioma cell lines resulted in a 2- to 4-fold increase in MT1-MMP mRNA levels. Although there were slight differences in MT2-, MT3-, and MT5-MMP mRNA expression following EGF stimulation, none of these demonstrated an increase similar to that of MT1-MMP expression. Treatment of high-grade glioma cell lines U251MG and IPSB-18 with EGF for 24 h resulted in a several-fold increase in MT1-MMP protein (2.5- and 5.1-fold, respectively) and in cyclin D1 (2.9-fold), as compared to untreated controls. No significant increase was detected in other MT-MMPs at the protein level. Although there was no detectable increase in proMMP-2 protein, there was an increase in MMP-2 activity. Furthermore, the MT1-MMP induction by EGF was prevented by pretreatment with the EGFR-specific tyrphostin inhibitor AG1478. Similarly, treatment with the phosphatidylinositol 3-kinase inhibitor LY294002 prevented the induction of MT1-MMP protein by EGF stimulation. These compounds additionally inhibited EGF-stimulated invasion in Matrigel Transwell assays. Our results indicate that one mechanism of EGFR-mediated invasiveness in gliomas may involve the induction of MT1-MMP.
doi:10.1215/S1152851703000486
PMCID: PMC1871990  PMID: 15279711
9.  Wilms' tumor 1 silencing decreases the viability and chemoresistance of glioblastoma cells in vitro: a potential role for IGF-1R de-repression 
Journal of Neuro-Oncology  2010;103(1):87-102.
Wilms' tumor 1 (WT1) is a transcription factor with a multitude of downstream targets that have wide-ranging effects in non-glioma cell lines. Though its expression in glioblastomas is now well-documented, the role of WT1 in these tumors remains poorly defined. We hypothesized that WT1 functions as an oncogene to enhance glioblastoma viability and chemoresistance. WT1's role was examined by studying the effect of WT1 silencing and overexpression on DNA damage, apoptosis and cell viability. Results indicated that WT1 silencing adversely affected glioblastoma viability, at times, in synergy with 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) and cisplatin. To investigate other mechanisms through which WT1 could affect viability, we measured cell cycle distribution, senescence, and autophagy. WT1 silencing had no effect on these processes. Lastly, we examined WT1 regulation of IGF-1R expression. Counterintuitively, upregulation of IGF-1R was evident after WT1 silencing. In conclusion, WT1 functions as a survival factor in glioblastomas, possibly through inhibition of IGF-1R expression.
doi:10.1007/s11060-010-0374-7
PMCID: PMC3277601  PMID: 20820871
Wilms' tumor 1; Glioblastoma; RNA interference; Chemosensitivity; IGF-1R

Results 1-9 (9)