Double-stranded RNA induction asa potential dynamic biomarkerfor DNA-demethylating agents

Area of Science:

• Oncology
• Immunology
• Molecular Biology

Background:

• Hypomethylating agents (HMAs) like azacitidine and decitabine induce cancer cell death by demethylating DNA and promoting tumor suppressor gene expression.
• HMAs also trigger innate immune responses and apoptosis through viral mimicry by reactivating endogenous double-stranded RNA (dsRNA) transcription.
• The expression patterns of endogenous dsRNAs and their role in HMA efficacy are not well understood.

Purpose of the Study:

• To investigate the dynamic expression patterns of total dsRNAs regulated by HMAs.
• To explore the potential of monitoring dsRNA levels as a predictive biomarker for HMA therapy outcomes.
• To identify factors influencing HMA efficacy, such as nc886 RNA expression.

Main Methods:

• Utilized amidine-conjugated spiropyran (Am-SP) to examine dynamic dsRNA expression.
• Analyzed bone marrow aspirates from myelodysplastic syndrome and acute myeloid leukemia patients treated with HMAs.
• Applied the approach to solid tumor cell lines to correlate dsRNA induction with decitabine effectiveness.

Main Results:

• A significant increase in total dsRNA levels was observed post-HMA treatment, specifically in patients who responded positively to therapy.
• The degree of dsRNA induction correlated with decitabine's effectiveness in most solid tumor cell lines.
• Decitabine efficacy was diminished when dsRNA induction was accompanied by increased nc886 RNA expression.

Conclusions:

• Monitoring total dsRNA levels using small molecules like Am-SP can serve as an analytical method.
• Increased dsRNA levels show potential as a dynamic biomarker for predicting clinical outcomes of HMA therapy.
• The interplay between dsRNA induction and nc886 RNA expression is critical for determining HMA treatment effectiveness.