CircRNA May Not Be "Circular"

Handong Sun; Zijuan Wu; Ming Liu; Liang Yu; Jianyong Li; Jinwen Zhang; Xiangming Ding; Hui Jin

doi:10.3389/fgene.2021.633750

CircRNA May Not Be "Circular"

Front Genet. 2021 Feb 19:12:633750. doi: 10.3389/fgene.2021.633750. eCollection 2021.

Authors

Handong Sun¹, Zijuan Wu^{2

3

4}, Ming Liu⁵, Liang Yu^{3

6}, Jianyong Li^{2

3

4}, Jinwen Zhang⁵, Xiangming Ding⁷, Hui Jin^{2

3

4}

Affiliations

¹ Department of Breast Surgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
² Department of Hematology, The First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, Nanjing, China.
³ Key Laboratory of Hematology of Nanjing Medical University, Nanjing, China.
⁴ Collaborative Innovation Center for Cancer Personalized Medicine, Nanjing, China.
⁵ Guangzhou Geneseed Biotech Co., Ltd., Guangzhou, China.
⁶ Department of Hematology, The Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, Huai'an, China.
⁷ Department of Bioinformatics, ATCGene Inc., Guangzhou, China.

Abstract

Circular RNA (circRNA) is a novel regulatory non-coding RNA and participates in diverse physiological and pathological processes. However, the structures and molecular mechanisms of circRNAs remain unclear. In this study, taking advantage of openly databases and bioinformatics analysis, we observed lots of internal complementary base-pairing sequences (ICBPS) existed in plenty of circRNAs, especially in extremely long circRNAs (el-circRNAs, > 5,000 nt). The result indicated that circRNA may not be a simple circular structure. In addition, we put forward the hypothesis of "open-close effect" in the transition for specific circRNA from normal state to morbid state. Taken together, our results not only expand the knowledge of circRNAs, but also highlight the potential molecular mechanism of circRNAs.

Keywords: bio-informatics; biological phenomena; circular RNA; hypothesis and theory; molecular conformation.