Methods and compositions for modulating gene expression
The present disclosure provides compositions with a modulating gene expression and methods for modulating transcription.
1. A method of decreasing expression of a gene within a cell, the gene being within an anchor sequence-mediated conjunction that comprises a first anchor sequence, a second anchor sequence, and an enhancer, the method comprising a step of:
contacting the cell with a composition comprising a targeting element or a nucleic acid encoding the targeting element, wherein the targeting element comprises a Cas protein and gRNA which bind specifically to the first anchor sequence, the second anchor sequence, or both of the first anchor sequence and the second anchor sequence, relative to non-target anchor sequences within the cell with sufficient affinity that it competes with binding of CTCF within the cell, wherein the first and second anchor sequences each comprise a CTCF binding site wherein the CTCF binding site has the sequence of SEQ ID NO: 1 or SEQ ID NO: 2.
2. The method of claim 1 , wherein neither the first nor second anchor sequences are located within an enhancer or a promoter.
3. The method of claim 1 , wherein the gene is FOXJ3.
4. The method of claim 1 , wherein the gRNA comprises a sequence of any of SEQ ID NOs: 40-47, 86, or 87.
5. The method of claim 1 , wherein the cell is a human cell.
6. The method of claim 1 , wherein the Cas protein comprises Cas9.
7. The method of claim 1 , wherein contacting comprises transfecting the cell with the composition.
8. The method of claim 1 , wherein the method further comprises substituting, adding or deleting one or more nucleotides within an anchor sequence of the anchor sequence-mediated conjunction.
9. The method of claim 8 , wherein the substitution, addition, or deletion of one or more nucleotides is in a CTCF binding site.
10. The method of claim 1 , wherein the gRNA has a length from about 10 to about 100 nucleotides.
11. The method of claim 1 , wherein the gRNA is or comprises a sequence at least 90% complementary to the first and/or second anchor sequence.
12. The method of claim 1 , wherein the composition physically interferes with formation and/or maintenance of the anchor sequence-mediated conjunction.
13. The method of claim 1 , wherein the gene is an oncogene, a tumor suppressor, or a gene associated with a nucleotide repeat.