ADAR1 RNA editing enzyme regulates R-loop formation and genome stability at telomeres in cancer cells

Area of Science:

• Molecular Biology
• Genetics
• Cancer Research

Background:

• ADAR1 (adenosine-to-inosine RNA editing) has two isoforms: cytoplasmic ADAR1p150 and nuclear ADAR1p110.
• ADAR1p150 function is known to suppress interferon induction and is critical for development.
• The role of ADAR1p110 in nuclear functions, particularly in cancer, remains largely unexplored.

Purpose of the Study:

• To investigate the biological functions of nuclear ADAR1p110 in cancer cells.
• To elucidate the role of ADAR1p110 in regulating genome stability at telomeres.
• To determine if ADAR1p110 is a potential therapeutic target in cancer.

Main Methods:

• Analysis of ADAR1p110 function in cancer cells with non-canonical telomeric repeats.
• Investigating ADAR1p110's role in editing RNA:DNA hybrids and R-loop resolution.
• Assessing the impact of ADAR1p110 activity on cancer cell proliferation and genome stability.

Main Results:

• ADAR1p110 regulates R-loop formation and genome stability at telomeres in cancer cells.
• ADAR1p110 edits A-C mismatches in telomeric RNA:DNA hybrids, facilitating R-loop resolution by RNase H2.
• ADAR1p110 activity is essential for the proliferation of telomerase-reactivated cancer cells.

Conclusions:

• ADAR1p110 plays a pro-oncogenic role by maintaining telomere stability and enabling cancer cell proliferation.
• ADAR1p110 is a promising therapeutic target for telomerase-positive cancers.
• Understanding ADAR1p110's function provides insights into cancer progression and potential treatment strategies.