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Updated: Aug 30, 2025
Antibody-Free Assay for RNA Methyltransferase Activity Analysis
Published on: July 9, 2019
Double-stranded RNA induction asa potential dynamic biomarkerfor DNA-demethylating agents
Minjeong Kang1, Raisa Kharbash1, Ja Min Byun2,3,4
1Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea.
Abstract:
Hypomethylating agents (HMAs), such as azacitidine and decitabine, induce cancer cell death by demethylating DNAs to promote the expression of tumor-suppressor genes. HMAs also reactivate the transcription of endogenous double-stranded RNAs (dsRNAs) that trigger the innate immune response and subsequent apoptosis via viral mimicry. However, the expression patterns of endogenous dsRNAs and their relevance in the efficacy of HMAs remain largely uninvestigated. Here, we employ amidine-conjugated spiropyran (Am-SP) to examine the dynamic expression pattern of total dsRNAs regulated by HMAs. By analyzing the bone-marrow aspirates of myelodysplastic syndrome or acute myeloid leukemia patients who received the HMAs, we find a dramatic increase in total dsRNA levels upon treatment only in patients who later benefited from the therapy. We further apply our approach in solid tumor cell lines and show that the degree of dsRNA induction correlates with the effectiveness of decitabine in most cases. Notably, when dsRNA induction is accompanied by increased expression of nc886 RNA, decitabine becomes ineffective. Collectively, our study establishes the potential application of monitoring the total dsRNA levels by a small molecule as an analytical method and a dynamic marker to predict the clinical outcome of the HMA therapy.
Insights
Hypomethylating agents (HMAs) increase double-stranded RNA (dsRNA) levels, predicting treatment success in cancer patients. However, increased nc886 RNA expression can reduce HMA effectiveness, highlighting a potential biomarker for therapy response.
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.
