Nanoparticle-mediated knockdown of DNA repair sensitizes cells to radiotherapy and extends survival in a genetic mousemodel of glioblastoma
NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE
Authors: Kievit, Forrest M.; Wang, Kui; Ozawa, Tatsuya; Tarudji, Aria W.; Silber, John R.; Holland, Eric C.; Ellenbogen, Richard G.; Zhang, Miqin
Abstract
Glioblastoma (GBM) remains incurable, and recurrent tumors rarely respond to standard-of-care radiation and chemo-therapies. Therefore, strategies that enhance the effects of these therapies should provide significant benefits to GBM patients. We have developed a nanoparticle delivery vehicle that can stably bind and protect nucleic acids for specific delivery into brain tumor cells. These nanoparticles can deliver therapeutic siRNAs to sensitize GBMcells to radiotherapy and improve GBM treatment via systemic administration. We show that nanoparticle mediated knockdown of the DNA repair protein apurinic endonuclease 1 (Ape1) sensitizes GBM cells to radiotherapy and extend survival in a genetic mouse model of GBM. Specific knockdown of Ape1 activity by 30% in brain tumor tissue doubled the extended survival achieved with radiotherapy alone. Ape1 is a promising target for increasing the effectiveness of radiotherapy, and nanoparticle-mediated delivery of siRNA is a promising strategy for tumor specific knockdown of Ape1. (C) 2017 Published by Elsevier Inc.
Array comparative genomic hybridization analysis of chromosomal imbalances and their target genes in gastrointestinal stromal tumors
GENES CHROMOSOMES & CANCER
Authors: Assamaki, Reetta; Sarlomo-Rilkala, Marit; Lopez-Guerrero, Jose Antonio; Lasota, Jerzy; Andersson, Leif C.; Llombart-Bosch, Antonio; Miettinen, Markku; Knuutila, Sakari
Abstract
Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the gastrointestinal tract. The tumors characteristically harbor KIT or PDGFRA mutations, and mutant tumors respond to imatinib mesylate (Glivec (TM)). Chromosomal imbalances resulting in altered gene dosage are known to have a role in the molecular pathogenesis of these tumors, but the target genes remain to be identified. The present study aimed to identify some of these genes. In total, 35 GIST samples were screened for chromosomal imbalances by array-based comparative genomic hybridization. A cDNA array was used to define the minimal common overlapping areas of DNA copy number change. Eight confirmative, replicate hybridizations were performed using an oligonucleotide array. The most recurrent copy number losses were localized to 14q, 22q, and 1p. Gains were less common with 8q being the most recurrent. Two recurrent deleted regions of 14q were 14q11.2 harboring the PARP2, APEX1, and NDRG2 genes and 14q32.33 harboring SIVA. Additional target candidates were NF2 at chromosome 22, CDKN2A/2B at 9p, and ENO1 at 1p for copy number losses, and MYC at 8q for copy number gains. Array CGH proved to be an effective tool for the identification of chromosome regions involved in the development and progression of GISTs. (c) 2007 Wiley-Liss, Inc.