Molecular strategies for improving cytokine transgene expression in normal and malignant tissues

Jh, Wang; Turner, Joel G.

doi:10.1038/sj.gt.3302137

Cited by 3 publications

(3 citation statements)

References 32 publications

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“…13,14,25,27 Similar to previous studies using other AAV gene therapies, 13,15,25,27,34,35 head-to-tail episomes are the primary forms of circular genomes in mice and non-human primates treated with AAV5-hFVIII-SQ; this configuration also appears to support stability of episomes and more efficient transcription of the transgene. 25,[36][37][38] Together, these data suggest that following AAV5-hFVIII-SQ transduction, the formation of circular episomes in the liver, particularly in the head-totail orientation, leads to efficient transcription and long-term FVIII expression in the liver.…”

Section: Discussionmentioning

confidence: 84%

Molecular analysis of AAV5-hFVIII-SQ vector-genome-processing kinetics in transduced mouse and nonhuman primate livers

Sihn

Handyside

Liu

et al. 2022

Molecular Therapy - Methods & Clinical Development

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Valoctocogene roxaparvovec (AAV5-hFVIII-SQ) is an adenoassociated virus serotype 5 (AAV5)-based gene therapy vector containing a B-domain-deleted human coagulation factor VIII (hFVIII) gene controlled by a liver-selective promoter. AAV5-hFVIII-SQ is currently under clinical investigation as a treatment for severe hemophilia A. The full-length AAV5-hFVIII-SQ is >4.9 kb, which is over the optimal packaging limit of AAV5. Following administration, the vector must undergo a number of genome-processing, assembly, and repair steps to form full-length circularized episomes that mediate long-term FVIII expression in target tissues. To understand the processing kinetics of the oversized AAV5-hFVIII-SQ vector genome into circular episomes, we characterized the various molecular forms of the AAV5-hFVIII-SQ genome at multiple time points up to 6 months postdose in the liver of murine and non-human primate models. Full-length circular episomes were detected in liver tissue beginning 1 week postdosing. Over 6 months, quantities of circular episomes (in a predominantly head-to-tail configuration) increased, while DNA species lacking inverted terminal repeats were preferentially degraded. Levels of duplex, circular, full-length genomes significantly correlated with levels of hFVIII-SQ RNA transcripts in mice and non-human primates dosed with AAV5-hFVIII-SQ. Altogether, we show that formation of full-length circular episomes in the liver following AAV5-hFVIII-SQ transduction was associated with long-term FVIII expression.

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Section: Discussionmentioning

confidence: 84%

Molecular analysis of AAV5-hFVIII-SQ vector-genome-processing kinetics in transduced mouse and nonhuman primate livers

Sihn

Handyside

Liu

et al. 2022

Molecular Therapy - Methods & Clinical Development

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“…To directly analyze the functional importance of these AREs, we constructed a luciferase reporter containing a fragment of the 3′ UTR of human CD274 containing the last six ATTTA pentamers, including the three conserved nonamer sequences. Mutation of ATTTA pentamers to ATGTA has been shown to increase the expression of ARE-containing mRNAs ( Rajagopalan et al., 1995 , Yang et al., 2004 ). Consistent with this, mutating the six ATTTA pentamer sequences to ATGTA increased expression of the PD-L1 3′ UTR luciferase reporter in ER-HRAS G12V MCF10A and H358 cells, suggesting that these AREs are functionally relevant for controlling the expression of PD-L1 ( Figures 2 E and 2F).…”

Section: Resultsmentioning

confidence: 99%

Oncogenic RAS Signaling Promotes Tumor Immunoresistance by Stabilizing PD-L1 mRNA

et al. 2017

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SummaryThe immunosuppressive protein PD-L1 is upregulated in many cancers and contributes to evasion of the host immune system. The relative importance of the tumor microenvironment and cancer cell-intrinsic signaling in the regulation of PD-L1 expression remains unclear. We report that oncogenic RAS signaling can upregulate tumor cell PD-L1 expression through a mechanism involving increases in PD-L1 mRNA stability via modulation of the AU-rich element-binding protein tristetraprolin (TTP). TTP negatively regulates PD-L1 expression through AU-rich elements in the 3′ UTR of PD-L1 mRNA. MEK signaling downstream of RAS leads to phosphorylation and inhibition of TTP by the kinase MK2. In human lung and colorectal tumors, RAS pathway activation is associated with elevated PD-L1 expression. In vivo, restoration of TTP expression enhances anti-tumor immunity dependent on degradation of PD-L1 mRNA. We demonstrate that RAS can drive cell-intrinsic PD-L1 expression, thus presenting therapeutic opportunities to reverse the innately immunoresistant phenotype of RAS mutant cancers.

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“…One way to stimulate immune system is in vivo transfer of one or more cytokine genes (interleukines [IL-2, IL-4, IL-6, IL-7, IL-12], tumor necrosis factor a(TNFa), granulocyte-macrophage colony-stimulating fac-tor (GM-CSF), interferon g(INFg), etc.) into tumor cells or ex vivo transfer in autologous fibroblasts followed by injection in situ (42). Another way is to deliver tumor antigens into suitably activated dendritic cells that will generate antitumor immunity.…”

Section: Therapeutic Genesmentioning

confidence: 99%

Cancer gene therapy

Mitrović

Radulović

2005

Arch Oncol

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Cancer gene therapy can be defined as transfer of nucleic acids into tumor or normal cells with aim to eradicate or reduce tumor mass by direct killing of cells, immunomodulation or correction of genetic errors, and reversion of malignant status. Initially started with lots of optimism and enthusiasm, cancer gene therapy has shown limited success in treatment of patients. This review highlights current limitations and almost endless possibilities of cancer gene therapy. The major difficulty in advancing gene therapy technology from the bench to the clinical practice is problem with gene delivery vehicles (so called vectors) needed to ferry genetic material into a cell. Despite few reports of therapeutic responses in some patients, there is still no proof of clinical efficacy of most cancer gene therapy approaches, primarily due to very low transduction and expression efficacy in vivo of available vectors. An "ideal" gene therapy vector should be administrated through a noninvasive route and should be targeted not only to primary tumor mass but also to disseminated tumor cells and micrometastases; it should also carry therapeutic gene with tumor-restricted, time-regulated, and sustained expression. Current strategies for combating the cancer with gene therapy can be divided into four basic concepts: (1) replacement of missing tumor suppressor gene and/or blocking of oncogenes or pro-inflammatory genes, (2) suicide gene strategies, (3) induction of immune-mediated destruction, and (4) inhibition of tumor angiogenesis. The advance in the clinical benefit of gene therapy will probably be first achieved with combining it with standard cancer treatment: chemotherapy, radiotherapy, and immunotherapy

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Molecular strategies for improving cytokine transgene expression in normal and malignant tissues

Cited by 3 publications

References 32 publications

Molecular analysis of AAV5-hFVIII-SQ vector-genome-processing kinetics in transduced mouse and nonhuman primate livers

Molecular analysis of AAV5-hFVIII-SQ vector-genome-processing kinetics in transduced mouse and nonhuman primate livers

Oncogenic RAS Signaling Promotes Tumor Immunoresistance by Stabilizing PD-L1 mRNA

Cancer gene therapy

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