Expression profile of circular RNAs in patients with unstable angina

Circular RNAs (circRNAs) are a new class of noncoding RNAs, which interfere with gene transcription by absorbing microRNAs (miRNAs).

The expression profile and roles of circRNAs in unstable angina (UA) patients remains unclear.

An initial screening of circRNA expression by microarray analysis was performed using blood samples from three pairs of UA patients and matched healthy individuals. The differential expression of the chosen six circRNAs from the results of the microarray analysis was validated by quantitative real-time polymerase chain reaction (qRT-PCR).

The microarray results demonstrated that some circRNAs were markedly different in UA patients, when compared with matched healthy individuals. In these UA patients, 22 circRNAs were upregulated and six circRNAs were downregulated when a P-value of < 0.05 was considered as a cut-off level and the fold change was > 1.5. Among the six circRNAs chosen for further analysis, qRT-PCR identified that five of these were upregulated, and the remaining circRNA was downregulated. By comparing the outcome of the six candidate circRNAs between the circRNAs microarray assay and RT-PCR validation, it was found that four circRNAs (hsa_circ_0002229, hsa_circ_0005580, hsa_circ_0046667, and hsa_circ_0001451) had the same variation trend.

The present study provided the expression profile of circRNAs in UA patients. Moreover, some circRNAs have the potential to be biomarkers for the detection of UA patients. Further studies with a larger population will focus on hsa_circ_0002229, hsa_circ_0005580, hsa_circ_0046667 and hsa_circ_0001451.