Hajar Zeidi - Department of Molecular Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
Rezvan Esmaeili - Genetics Department, Breast Cancer Research Center, Motamed Cancer Institute, ACECR, Tehran, Iran
Sadegh Babashah - Department of Molecular Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran

Backgrounds: Breast cancer (BC) is one of the most common cancers and the second highestmortality in women worldwide. Different studies have shown that there is a close correlationbetween circRNAs and initiation and progression of different cancers and diseases; however,knowledge about the correlation between non-coding RNAs, especially the circRNAs and BC, isnot fully explored. In this study, the expression level of circ-۰۰۷۲۳۰۹ (LIFR) in BC wasinvestigated experimentally and miRNA target genes for it were proposed.Materials and Methods: BC tissue specimens (twenty-nine causes) and their correspondingadjacent normal tissue were collected during the surgery and has-circ-۰۰۷۲۳۰۹ expression inbreast cancer tissues was analyzed using qRT-PCR. A series of functional experiments werecarried out to investigate has-circ-۰۰۷۲۳۰۹ function in breast cancer development. Additionally,miRNAs that potentially target has-circ-۰۰۷۲۳۰۹ were predicted by bioinformatics method.miRTargetlink database (https://ccb-web.cs.uni-saarland.de/mirtargetlink) and DIANA database(http://diana.imis.athena-innovation.gr/DianaTools/index.php?r=mirpath/index/) were used topredict interactions of miRNAs with LIFR.Results: The lower expression levels of circ-۰۰۷۲۳۰۹ in BC tissues was showed compared topaired adjacent normal tissues with P value (P <۰.۰۰۲). The area under the receiver operatingcharacteristic (ROC) curve was ۰.۷۶۸. In addition, a total ۱۰ miRNAs that can be targeted bycandidate circRNA was predicted base on bioinformatics databases. Moreover, miRNAsselection tools predicted that miR-۱۲۵a-۵p and miR-۲۰۳a-۳p can be targeted by circ-۰۰۷۲۳۰۹.Conclusion: Our findings revealed that the has-circ-۰۰۷۲۳۰۹ plays an essential role in BCprogression and circ-۰۰۷۲۳۰۹ could serve as a prognostic biomarker of BC.

Circular RNA, microRNA, Breast cancer, DIANA database, miRTargetlink database