Cell lines

Epithelial (A549) and melanoma (MelJuSo) cell line derivatives

Preparation method

Soluble in DMSO > 10 mM. General tips for obtaining a higher concentration: Please warm the tube at 37 ℃ for 10 minutes and/or shake it in the ultrasonic bath for a while. Stock solution can be stored below -20℃ for several months.

Reaction Conditions

24 hours at 37℃

Applications

Scr7 increases the efficiency of insertional mutagenesis in cell lines. In A549 cells, 0.01 μM Scr7 improves the efficiency of insertion at the target site about threefold relative to the untreated control. In Scr7-treated MelJuSo cells, the insertion efficiency is also enhanced in a dose-dependent manner up to 19-fold.

Animal models

Kell-LPETG mice

Dosage form

CRISPR components mixture (Cas9 mRNA, sgRNA and targeting template) and 10 mM of Scr7 NHEJ inhibitor (to 1 mM final) were injected into the cytoplasm at the pronuclear stage. The injected zygotes were transferred at the 2-cell stage into the pseudo-pregnant females.

Applications

Co-injection of Scr7 increases the efficiency of precise genome editing in mouse embryos. The insertion efficiency with Scr7 co-injection is significantly higher (P = 0.0012) compared to blastocysts not injected with Scr7. The insertion efficiency in Scr7-co-injected E10 embryos is also significantly enhanced compared to E10 embryos not injected with Scr7 (P = 0.003).

Other notes

Please test the solubility of all compounds indoor, and the actual solubility may slightly differ with the theoretical value. This is caused by an experimental system error and it is normal.

Scr7 is a DNA ligase IV inhibitor, initially identified as an anti-cancer agent [1].
Scr7 targets the DNA binding domain of DNA ligase IV, reducing its affinity for double strand breaks (DSBs) and inhibiting its function. Scr7 also inhibits DNA ligase III (but not DNA ligase I), albeit less efficiently. Cells were treated with doxycycline to induce Cas9 expression, with various concentrations of Scr7 for 24 h. Scr7 maintained cells capable of entering S/G2 phase, which is necessary for HDR. [1] Treatment of mice with Scr7 affects lymphocyte development, as DNA ligase IV plays a key role in the joining of coding ends during V(D)J recombination by means of C-NHEJ16. The defects in lymphocyte development upon Scr7 treatment are transient and reversible, due to the noncovalent mode of binding of Scr7. Scr7 enhanced the frequency of HDR by transiently blocking NHEJ (with the exception of DNA ligase I–dependent alt-NHEJ), resulting in precise genome editing by CRISPR-Cas9 in both cultured cells and in mice. [2]
References:
[1]. Srivastava M, Nambiar M, Sharma S et al. An inhibitor of nonhomologous end-joining abrogates double-strand break repair and impedes cancer progression. Cell. 2012 Dec 21;151(7):1474-87. doi: 10.1016/j.cell.2012.11.054.
[2]. Maruyama T, Dougan SK, Truttmann MC et al.Increasing the efficiency of precise genome editing with CRISPR-Cas9 by inhibition of nonhomologous end joining. Nat Biotechnol. 2015 Mar 23. doi: 10.1038/nbt.3190. [Epub ahead of print]