Circular RNAs in cancer: new insights into functions and implications in ovarian cancer

Zahra Shabaninejad,Hadis Fathizadeh,Amir Savardashtaki,Asma Vafadar,Ahmad Movahedpour,Afshin Namdar,Younes Ghasemi,Mohammad Hossein Pourhanifeh,Hamed Mirzaei

doi:10.1186/s13048-019-0558-5

Abstract

Circular RNAs (circRNAs) are a class of long non-coding RNAs (lncRNAs) which have a circular and closed loop structure. They are ubiquitous, stable, conserved and diverse RNA molecules with a range of activities such as translation and splicing regulation, which are able to interacting with RNA-binding proteins and specially miRNA sponge. The expression patterns of the circRNAs exhibited tissue specificity and also, step and stage specificity. Accumulating evidences approved the critical role of circular RNAs in many cancers such as ovarian cancer. Given that these molecules exert their effects through multiple cellular and molecular mechanisms (i.e., angiogenesis, apoptosis, growth, and metastasis) which are involved in cancer pathogenesis, circular RNAs, in particular, act by controlling cell proliferation in ovarian cancer, so that, it has been shown that the deregulation of these molecules is associated with initiation and progression of ovarian cancer. Therefore, they are attractive molecules which have introduced them as cancer biomarkers. Moreover, they could be used as new therapeutic candidates for developing novel treatment strategies. Here, for first time, we have provided a comprehensive review on the recent knowledge of circular RNAs and their pathological roles in the ovarian cancer.

Highlights

The majority portion of genome is assigned to non-coding RNAs rather than protein coding mRNAs [1]
Based on the nucleotide fragment length, the regulatory ncRNAs can be classified into < 200 nucleotides in transcript length, some of which are microRNAs and siRNAs, and the long non coding RNAs which possess transcripts with more than 200 nucleotides in length [2, 3]
Circular RNAs group is a member of long non coding RNAs (lncRNAs) with a large variation in length ranged from hundreds to thousands nucleotides [4]

Summary

Introduction

The majority portion of genome (approximately 98%) is assigned to non-coding RNAs (ncRNAs) rather than protein coding mRNAs [1]. Promote the HCC progression and cell growth via miR9-P21 Promote the lung metastasis, vascular invasion, and TNM Suppress G1/S arrest, induce cell proliferation and upregulate the expression of CDK6 Development of OSCC via the p53/Bcl-2/caspase signaling pathway. Promote the osteosarcoma growth and inhibit the In vitro, Tissues, [62] apoptosis, and promote the osteosarcoma progression In vivo Cell line

Results

Conclusion