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Pumpkin Center, NC, United States

Reardon D.A.,Duke University | Reardon D.A.,Preston Robert Tisch Brain Tumor Center | Vredenburgh J.J.,Duke University | Coan A.,Duke University | And 7 more authors.
Journal of Neuro-Oncology | Year: 2011

We determined the maximum tolerated dose (MTD) and dose-limiting toxicities (DLT) of the oral vascular endothelial growth factor receptor (VEGFR) inhibitor, sunitinib, when administered with irinotecan among recurrent malignant glioma (MG) patients. For each 42-day cycle, sunitinib was administered once a day for four consecutive weeks followed by a 2 week rest. Irinotecan was administered intravenously every other week. Each agent was alternatively escalated among cohorts of 3-6 patients enrolled at each dose level. Patients on CYP3A-inducing anti-epileptic drugs were not eligible. Twenty-five patients with recurrent MG were enrolled, including 15 (60%) with glioblastoma (GBM) and 10 (40%) with grade 3 MG. Five patients progressed previously on bevacizumab and two had received prior VEGFR tyrosine kinase inhibitor therapy. The MTD was 50 mg of sunitinib combined with 75 mg/m 2 of irinotecan. DLT were primarily hematologic and included grade 4 neutropenia in 3 patients and one patient with grade 4 thrombocytopenia. Non-hematologic DLT included grade 3 mucositis (n = 1) and grade 3 dehydration (n = 1). Progression-free survival (PFS)-6 was 24% and only one patient achieved a radiographic response. The combination of sunitinib and irinotecan was associated with moderate toxicity and limited anti-tumor activity. Further studies with this regimen using the dosing schedules evaluated in this study are not warranted. © 2011 Springer Science+Business Media, LLC. Source

Mattox A.K.,Preston Robert Tisch Brain Tumor Center | Mehta A.I.,Duke University | Grossi P.M.,Duke University | Cumm Ings T.S.J.,Duke University | And 3 more authors.
Journal of Neurosurgery | Year: 2010

Dermatofibrosarcoma protuberans (DFSP) is an uncommon, locally aggressive, malignant cutaneous tumor that sparingly presents on the scalp. Dermatofibrosarcomas often result from the formation of a fusion oncogene on translocated or supernumerary ring chromosomes 17 and 22, causing the overexpression of PDGFRβ driven by the COL1A1 promoter. Because of uncertainty surrounding appropriate treatment of aggressive scalp DFSP, the authors performed an extensive review of the available data from a MEDLINE (Ovid) search to describe the clinical presentation and treatment options for this rare tumor. Their search identified 39 different cases, including the illustrative case presented in this study. Adjuvant therapy for this malignant lesion is not universally established in the literature. In the present case, the authors successfully treated a locally invasive scalp DFSP with presurgical therapy that specifically inhibited the PDGFβ receptor. Imatinib significantly shrank the DFSP tumor mass, reduced hypervascularity, reduced metabolic activity on PET scanning, and permitted a safe gross-total resection. Although wide excision and Mohs micrographic surgery remain the standard surgical treatments for DFSP, the authors illustrate that presurgical chemotherapeutic treatment by imatinib provides a critical adjunct to traditional therapy. Source

Li J.,Preston Robert Tisch Brain Tumor Center | Li J.,Duke University | Di C.,Preston Robert Tisch Brain Tumor Center | Di C.,Duke University | And 7 more authors.
Pharmacogenomics and Personalized Medicine | Year: 2010

Glioblastoma multiforme (GBM) remains one of the most malignant primary central nervous system tumors. Personalized therapeutic approaches have not become standard of care for GBM, but science is fast approaching this goal. GBM's heterogeneous genomic landscape and resistance to radiotherapy and chemotherapy make this tumor one of the most challenging to treat. Recent advances in genome-wide studies and genetic profiling show that there is unlikely to be a single genetic or cellular event that can be effectively targeted in all patients. Instead, future therapies will likely require personalization for each patient's tumor genotype or proteomic profile. Over the past year, many investigations specifically focused simultaneously on strategies to target oncogenic pathways, angiogenesis, tumor immunology, epigenomic events, glioma stem cells (GSCs), and the highly migratory glioma cell population. Combination therapy targeting multiple pathways is becoming a fast growing area of research, and many studies put special attention on small molecule inhibitors. Because GBM is a highly vascular tumor, therapy that directs monoclonal antibodies or small molecule tyrosine kinase inhibitors toward angiogenic factors is also an area of focus for the development of new therapies. Passive, active, and adoptive immunotherapies have been explored by many studies recently, and epigenetic regulation of gene expression with microRNAs is also becoming an important area of study. GSCs can be useful targets to stop tumor recurrence and proliferation, and recent research has found key molecules that regulate GBM cell migration that can be targeted by therapy. Current standard of care for GBM remains nonspecific; however, pharmacogenomic studies are underway to pave the way for patient-specific therapies that are based on the unique aberrant pathways in individual patients. In conclusion, recent studies in GBM have found many diverse molecular targets possible for therapy. The next obstacle in treating this fatal tumor is ascertaining which molecules in each patient should be targeted and how best to target them, so that we can move our current nonspecific therapies toward the realm of personalized medicine. © 2010 Li et al. Source

Nair S.K.,Duke University | Nair S.K.,Preston Robert Tisch Brain Tumor Center | Driscoll T.,Duke University | Boczkowski D.,Duke University | And 18 more authors.
Journal of Neuro-Oncology | Year: 2015

Generation of patient-derived, autologous dendritic cells (DCs) is a critical component of cancer immunotherapy with ex vivo-generated, tumor antigen-loaded DCs. An important factor in the ability to generate DCs is the potential impact of prior therapies on DC phenotype and function. We investigated the ability to generate DCs using cells harvested from pediatric patients with medulloblastoma for potential evaluation of DC-RNA based vaccination approach in this patient population. Cells harvested from medulloblastoma patient leukapheresis following induction chemotherapy and granulocyte colony stimulating factor mobilization were cryopreserved prior to use in DC generation. DCs were generated from the adherent CD14+ monocytes using standard procedures and analyzed for cell recovery, phenotype and function. To summarize, 4 out of 5 patients (80 %) had sufficient monocyte recovery to permit DC generation, and we were able to generate DCs from 3 out of these 4 patient samples (75 %). Overall, we successfully generated DCs that met phenotypic requisites for DC-based cancer therapy from 3 out of 5 (60 %) patient samples and met both phenotypic and functional requisites from 2 out of 5 (40 %) patient samples. This study highlights the potential to generate functional DCs for further clinical treatments from refractory patients that have been heavily pretreated with myelosuppressive chemotherapy. Here we demonstrate the utility of evaluating the effect of the currently employed standard-of-care therapies on the ex vivo generation of DCs for DC-based clinical studies in cancer patients. © 2015, Springer Science+Business Media New York. Source

Li J.,Preston Robert Tisch Brain Tumor Center | Li J.,Duke University | Di C.,Preston Robert Tisch Brain Tumor Center | Di C.,Duke University | And 9 more authors.
International Journal of Oncology | Year: 2015

The homeobox transcription factor orthodenticle homeobox 2 (OTX2) plays a critical role in very early neurogenesis, but can become oncogenic when aberrantly expressed later in life. We previously discovered its novel oncogenic role in the malignant childhood brain tumor medulloblastoma and hypothesize an oncogenic role in retinoblastoma. Primary retinoblastoma tumors and cell lines were analyzed by quantitative-PCR, immunoblotting and immunohistochemistry for OTX2. The effect of modulating OTX2 expression on tumorigenesis was tested pharmacologically and by siRNA. A lentiviral shRNA-engineered vector was used for conditional knockdown studies on tumor growth in vivo. A luciferase reporter assay was used to analyze ATRA's effect on OTX2's promoter. In this study on retinoblastoma, OTX2 was frequently amplified and/or overexpressed in primary tumors and cell lines. Knockdown of OTX2 expression by siRNA or pharmacologic inhibition by all-trans retinoic acid (ATRA) repressed OTX2 expression and cell proliferation and significantly decreased tumor growth in vivo. Loss of OTX2 expression also resulted in decreased expression of C-MYC and CRX, genes previously implicated in retinoblastoma tumorigenesis. Loss of OTX2 expression increased the phosphorylation of RB, a potential mechanism of modulating cell proliferation. Aberrant expression of OTX2 may contribute to the development of retinoblastoma. OTX2 may serve as a common transcription factor that interlinks multiple tumordriving pathways. These results also show that OTX2 can be genetically and pharmacologically targeted, providing an exciting new therapeutic option that may be less toxic and more efficacious than current treatments. Source

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