Circular RNAs expressed in chorionic villi are probably involved in the occurrence of recurrent spontaneous abortion

Abstract Recurrent spontaneous abortion (RSA) is an unknown aetiology common disease troubled women all over the world. Recent studies of circular RNAs (circRNAs) in gynecology and obstetrics area have sprung up. Our purpose in this study was to investigate the expression of circRNAs in chorionic villi from patients with RSA versus corresponding healthy gravidas, and to infer the potential role of these circRNAs in RSA occurrence. We selected 35 pairs of RSA patients and healthy control subjects, and analyzed the aberrant circRNA expression in three pairs of villi samples from each group using circRNA microarray. Altogether, including 335 up-regulated and 259 down-regulated circRNAs, 594 aberrant expressed circRNAs (FC ≥ 2.0, P ≤ 0.05) were found. Considering the raw content of each circRNAs, fold change differences and the restriction of the divergent primers, four down-regulated circRNAs (hsa_circRNA_104948, 104547, 101319 and 104938) and four up-regulated (hsa_circRNA_102116, 100709, 102424 and 103102) were selected as validation genes, using real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Paired t -test and receiver operating characteristic (ROC) curves were also established. The result of content verification was accordant exactly with the microarray chip outcome (P ≤ 0.05 in all validation circRNAs). The area under the ROC curves (AUCs) of these eight circRNAs were all greater than 0.5. Further function analysis of circRNAs in RSA patients was performed by paper comparison. Taken together, aberrant villi circRNA expression in RSA played a vital role in its nosogenesis possibly via miRNA sponge function of circRNAs. Deeper analysis of the detailed mechanisms will be worthwhile.