Targeted repression of AXIN2 and MYC gene expression using designer TALEs

Journal Article · Fri Apr 18 04:00:00 EDT 2014 · Biochemical and Biophysical Research Communications

DOI:https://doi.org/10.1016/J.BBRC.2014.03.077· OSTI ID:22416388

Rennoll, Sherri A.; Scott, Samantha A.

Highlights: • We designed TALE–SID fusion proteins to target AXIN2 and MYC. • TALE–SIDs bound the chromosomal AXIN2 and MYC genes and repressed their expression. • TALE–SIDs repress β-catenin{sup S45F}-dependent AXIN2 and MYC transcription. - Abstract: Designer TALEs (dTALEs) are chimeric transcription factors that can be engineered to regulate gene expression in mammalian cells. Whether dTALEs can block gene transcription downstream of signal transduction cascades, however, has yet to be fully explored. Here we tested whether dTALEs can be used to target genes whose expression is controlled by Wnt/β-catenin signaling. TALE DNA binding domains were engineered to recognize sequences adjacent to Wnt responsive enhancer elements (WREs) that control expression of axis inhibition protein 2 (AXIN2) and c-MYC (MYC). These custom DNA binding domains were linked to the mSin3A interaction domain (SID) to generate TALE–SID chimeric repressors. The TALE–SIDs repressed luciferase reporter activity, bound their genomic target sites, and repressed AXIN2 and MYC expression in HEK293 cells. We generated a novel HEK293 cell line to determine whether the TALE–SIDs could function downstream of oncogenic Wnt/β-catenin signaling. Treating these cells with doxycycline and tamoxifen stimulates nuclear accumulation of a stabilized form of β-catenin found in a subset of colorectal cancers. The TALE–SIDs repressed AXIN2 and MYC expression in these cells, which suggests that dTALEs could offer an effective therapeutic strategy for the treatment of colorectal cancer.

• OSTI ID: 22416388
• Journal Information: Biochemical and Biophysical Research Communications, Journal Name: Biochemical and Biophysical Research Communications Journal Issue: 4 Vol. 446; ISSN 0006-291X; ISSN BBRCA9
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
BUILDUP
CELL NUCLEI
CONTROL
DNA
GENES
INHIBITION
LUCIFERASE
NEOPLASMS
TAMOXIFEN
TRANSCRIPTION
TRANSCRIPTION FACTORS