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Updated: Jun 30, 2026
Detection and Monitoring of Tumor Associated Circulating DNA in Patient Biofluids
Published on: June 8, 2019
Detection of mutant cancer-derived circRNAs in extracellular vesicles by rolling circle amplification
Mikołaj Piotr Zaborowski1,2,3,4, Charles Pin-Kuang Lai1,2, Alessandro Sammarco1,2,5
1Department of Neurology, Massachusetts General Hospital, Charlestown, MA 02129, USA.
Abstract:
Circular RNAs (circRNAs) form during splicing as a closed ring and are more resistant to degradation than linear RNAs. Cells release circRNAs within membrane-bound extracellular vesicles (EVs), which transport DNA, RNA, and proteins. Whether circRNAs in EVs can be used as biomarkers remains uncertain. We aimed to identify mutant circRNAs in EVs to develop a new biomarker approach. We demonstrated that ovarian cancer cells release and enrich circRNAs in EVs. We detected mutant circular transcripts from TP53, KRAS, and PIK3CA genes in EVs from cancer cells. We noticed that circRNAs in EVs undergo intense rolling circle amplification (RCA), producing multiple copies of the mutant sequence. We revealed that increased reverse transcription time and extended PCR elongation time intensified RCA. Using our RCA protocol, we detected mutant circRNAs derived from the TP53 gene in EVs from the plasma of ovarian cancer-bearing animals. In this study, we present a new model of mutant circRNA amplification from EVs, which may provide a basis for a diagnostic test for ovarian cancer patients.
Insights
Researchers identified mutant circular RNAs (circRNAs) in extracellular vesicles (EVs) from ovarian cancer cells. This discovery may lead to a new diagnostic test for ovarian cancer using these EV-derived mutant circRNAs.
Area of Science:
- Biochemistry
- Molecular Biology
- Oncology
Background:
- Circular RNAs (circRNAs) are stable RNA molecules released by cells in extracellular vesicles (EVs).
- The potential of circRNAs within EVs as biomarkers for diseases like ovarian cancer is largely unexplored.
- Ovarian cancer cells are known to release circRNAs, but their specific role and utility as biomarkers require further investigation.
Purpose of the Study:
- To investigate the presence and potential utility of mutant circRNAs within EVs as biomarkers for ovarian cancer.
- To develop a method for detecting and amplifying mutant circRNAs from EVs for diagnostic purposes.
Main Methods:
- Ovarian cancer cells were analyzed for circRNA release into EVs.
- Mutant circular transcripts from key cancer genes (TP53, KRAS, PIK3CA) were identified in EVs.
- A rolling circle amplification (RCA) protocol was optimized by adjusting reverse transcription and PCR elongation times.
- The optimized RCA protocol was used to detect mutant circRNAs from TP53 in EVs from plasma of tumor-bearing animals.
Main Results:
- Ovarian cancer cells were confirmed to release and enrich circRNAs in EVs.
- Mutant circular transcripts of TP53, KRAS, and PIK3CA were detected in EVs derived from cancer cells.
- Rolling circle amplification (RCA) was observed to intensely amplify mutant circRNAs within EVs.
- Optimized RCA conditions successfully detected TP53 mutant circRNAs in EVs from plasma of ovarian cancer-bearing animals.
Conclusions:
- A novel model for amplifying mutant circRNAs from EVs has been established.
- This amplification method shows promise for developing a diagnostic test for ovarian cancer.
- EV-derived mutant circRNAs represent a potential new class of biomarkers for ovarian cancer detection.
