Neural stem cells target intracranial glioma to deliver an oncolytic adenovirus in vivo

Abstract

Adenoviral oncolytic virotherapy represents an attractive treatment modality for central nervous system (CNS) neoplasms. However, successful application of virotherapy in clinical trials has been hampered by inadequate distribution of oncolytic vectors. Neural stem cells (NSCs) have been shown as suitable vehicles for gene delivery because they track tumor foci. In this study, we evaluated the capability of NSCs to deliver a conditionally replicating adenovirus (CRAd) to glioma. We examined NSC specificity with respect to viral transduction, migration and capacity to deliver a CRAd to tumor cells. Fluorescence-activated cell sorter (FACS) analysis of NSC shows that these cells express a variety of surface receptors that make them amenable to entry by recombinant adenoviruses. Luciferase assays with replication-deficient vectors possessing a variety of transductional modifications targeted to these receptors confirm these results. Real-time PCR analysis of the replication profiles of different CRAds in NSCs and a representative glioma cell line, U87MG, identified the CRAd-Survivin (S)-pk7 virus as optimal vector for further delivery studies. Using in vitro and in vivo migration studies, we show that NSCs infected with CRAd-S-pk7 virus migrate and preferentially deliver CRAd to U87MG glioma. These results suggest that NSCs mediate an enhanced intratumoral distribution of an oncolytic vector in malignant glioma when compared with virus injection alone.

RETRACTED ARTICLE: Targeted suicide gene therapy for glioma using human embryonic stem cell-derived neural stem cells genetically modified by baculoviral vectors

“…Pre-existing host immune response against adenoviral vectors, a type of vectors commonly used for transient transgene expression, is another concern that restricts the use of these vectors. [49][50][51] Unlike adenovirus, baculovirus is not targeted by pre-existing immunity in humans. 52 Furthermore, baculovirus transduction has been shown to display no effect on the immunological properties on mesenchymal stem cells, especially the ability of mesenchymal stem cells to evade immune recognition in immunocompetent rats.…”

Conversion of differentiated cancer cells into cancer stem-like cells in a glioblastoma model after primary chemotherapy

“…For in vitro experiments, on serial time points post-TMZ or DMSO addition (days 2, 4, 6, and 8) cells were collected, labeled, and analyzed for both surface and intracellular markers as previously described. 43 The following human-specific antibodies were used: anti-CD133-PE (2 : 100; Miltenyi Biotec, Auburn, CA, USA), anti-CD15-APC (5 : 100; BD Pharminogen, San Diego, CA, USA), anti-Oct4-FITC (5 : 100; Millipore, Billerica, MA, USA), antiKi67-FITC (4 : 100; Abcam, Cambridge, MA, USA), biotinylated anti-SOX2 (4 : 100; R&D Systems), purified rabbit anti-Nestin (4 : 100; Covance, Berkeley, CA, USA), purified monoclonal anti-HIF1A (hypoxia-inducible factor-1A; 4 : 100; Abcam), purified monoclonal anti-HIF2A (4 : 100; Millipore), purified polyclonal rabbit anti-MGMT (4 : 100; Cell Signaling, Beverly, MA, USA); and anti-mouse CD45 eFluor450 (eBioscience, San Diego, CA, USA). In addition, we used as secondary antibodies anti-rabbit IgGk1 FITC (1 : 500; Santa Cruz Biotechnology, Santa Cruz, CA, USA), anti-mouse IgGk1 PB (1 : 500; Abcam), and Streptavidin PB (1 : 500; Molecular Probes, Eugene, OR, USA).…”

Development of a DNA-Based Vaccine for Treatment of an Intracerebral Tumor

“…Antisense oligodeoxynucleotides which target mRNA encoding TGF-beta2, a cytokine secreted by brain tumors with immunosuppressive activity, have been used in a series of Phase I and II clinical trials along with an international Phase III study with some success [Hau et al, 2009]. Finally one of the problems using large viruses in treating brain tumors is that the viruses have a limited capacity to infiltrate into the brain, but recently it has been shown that neural stem cells infected with replicating adenovirus can be used to enhance intratumoral distribution of the oncolytic vectors into a malignant glioma in comparison with virus injection alone [Tyler et al, 2009].…”