- Research Tools
- Michaela McCrary
Gene therapies offer promising prospects of treating a wide variety of human diseases. In one method, a gene therapy vector can be utilized to deliver an unmutated copy of a gene, called a transgene, to replace a mutated gene in order to treat the genetic disorder. However, lack of expression of a therapeutic transgene and uncontrolled gene silencing are still major obstacles for safety and efficacy of these gene therapy interventions. There remains a need for a gene therapy vector that can deliver a stably maintained, appropriately regulated therapeutic transgene without adverse side effects.
Researchers at the National Cancer Institute (NCI) have shown that the inclusion of functional replicators, DNA sequences on chromatin that affect the sites of DNA replication initiation, can prevent gene silencing when incorporated into transgenes. The extent of transcriptional silencing of gene therapy vectors depends on their chromosomal location and on presence of nearby heterochromatin. Replicators interact with distal sequences to establish an epigenetic permissive state that directs the replication machinery to the replicator at a specific time during S phase. Most active genes replicate early during S phase, while transcriptional silencing correlates with late replication. NCI findings suggest that replicator sequences have an important role in stabilizing gene expression patterns, and the inclusion of replicators may be crucial in the prevention of gene silencing and replication delay.
Protected claims for this invention are directed to specific constructs and methods of use to inhibit, delay or prevent gene silencing. This technology thus enables the inclusion of functional elements in gene delivery vectors that permit stable maintenance and long-term regulated transgene expression, which may be key in the development of effective gene delivery vectors. This technology is available for licensing.
- Methodology for inhibiting or delaying gene silencing through specific transgene constructs
- Method for generation of gene therapy vectors
- Improved vector effectiveness by allowing greater gene expression regulation
- Greater stability to extend the duration of effective gene therapy, potentially requiring fewer doses
- Improved vector safety by preventing gene silencing
- Relevant to the advancement of non-viral vector development, which have fewer safety concerns compared to viral vectors
Mirit Aladiem, Cindy Tseng, Haiqing Fu, Lixin Wang (NCI)
- Discovery (Lead Identification)
Fu et al. Preventing gene silencing with human replicators. Nat Biotechnol. 2006 May;24(5):572-6
Huang L, Fu H, Lin CM, Conner AL, Zhang Y, Aladjem MI. Prevention of transcriptional silencing by a replicator-binding complex consisting of SWI/SNF,
MeCP1, and hnRNP C1/C2. Mol Cell Biol. 2011 Aug;31(16):3472-84. doi: 10.1128/MCB.05587-11. Epub 2011 Jun 20.
Martin MM, Ryan M, Kim R, Zakas AL, Fu H, Lin CM, Reinhold WC, Davis SR, Bilke S, Liu H, Doroshow JH, Reimers MA, Valenzuela MS, Pommier Y, Meltzer PS,
Aladjem MI. Genome-wide depletion of replication initiation events in highly transcribed regions. Genome Res. 2011 Nov;21(11):1822-32. doi:
10.1101/gr.124644.111. Epub 2011 Aug 3.
Zhang Y, Huang L, Fu H, Smith OK, Lin CM, Utani K, Rao M, Reinhold WC, Redon CE, Ryan M, Kim R, You Y, Hanna H, Boisclair Y, Long Q, Aladjem MI. A
replicator-specific binding protein essential for site-specific initiation of DNA replication in mammalian cells. Nat Commun. 2016 Jun 8;7:11748. doi: 10.1038/ncomms11748
Jang SM, Zhang Y, Utani K, Fu H, Redon CE, Marks AB, Smith OK, Redmond CJ, Baris AM, Tulchinsky DA, Aladjem MI. The replication initiation determinant
protein (RepID) modulates replication by recruiting CUL4 to chromatin. Nat Commun. 2018 Jul 17;9(1):2782. doi: 10.1038/s41467-018-05177-6.
Jang SM, Nathans JF, Fu H, Redon CE, Jenkins LM, Thakur BL, Pongor LS, Baris AM, Gross JM, OʹNeill MJ, Indig FE, Cappell SD, Aladjem MI. The RepID-CRL4
ubiquitin ligase complex regulates metaphase to anaphase transition via BUB3 degradation. Nat Commun. 2020 Jan 7;11(1):24. doi: 10.1038/s41467-019-13808-9.
Fu H, Redon CE, Thakur BL, Utani K, Sebastian R, Jang SM, Gross JM, Mosavarpour S, Marks AB, Zhuang SZ, Lazar SB, Rao M, Mencer ST, Baris AM, Pongor
LS, Aladjem MI. Dynamics of replication origin over-activation. Nat Commun. 2021 Jun 8;12(1):3448. doi: 10.1038/s41467-021-23835-0.
- U.S. Patent Issued: U.S. Patent Number , Issued 06 May 2014