Circular RNA hsa_circ_0003227 may serve as a diagnostic marker for breast cancer

Circular RNA hsa_circ_0003227 may serve as a diagnostic marker for breast cancer
Shirin Bayandorno,¹ Dr.Mahdieh Salimi ,^2,* Dr.Hamidreza Vaziri,³ Dr.Hossein Mozdarani,⁴
1. Department of Biology, Faculty of Sciences, University of Guilan , Rasht , Iran
2. Department of medical genetics, institute of medical biotechnology, national institute of genetic engineering and biotechnology ( NIGEB)
3. Department of Biology, Faculty of Sciences, University of Guilan , Rasht , Iran
4. Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran,Iran
Introduction: Circular RNAs (circRNAs) is an emerging type of ncRNAs without protein translation capacity . CircRNAs is characterized by covalently closed loops without 3’- and 5’- end, which is absolutely different from linear RNA [9]. Compared to microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), circRNAs have more stable construction and sequence conservation to resist the digestion of enzyme. Thus, circRNAs could much easier to be accumulated in cytoplasm or interstitial fluid, presenting higher concentration than corresponding linear RNAs. Emerging evidence suggests that the biological functions of circRNAs including serving as ceRNAs or miRNA sponges, interacting with proteins , regulating gene transcription and translation, suggesting that circRNAs will be novel biomarkers and targets for the diagnosis and prognosis of diseases. Increasing evidences have indicated that circRNAs take part in the regulation of tumorigenesis, including genesis, differentiation, migration and metastasis . It is vital to understand the molecular pathways involved in the pathogenesis of proliferation and progression . The circular RNAs can be easily detected due to their relative stability , widespread expression, and abundance in exosomes, blood, and saliva; thus, circular RNAs have potential as new and ideal clinical biomarkers in cancer.
Methods: In this study, the expression of hsa_circ_0003227 for the first time in the blood of patients with breast cancer, before and after chemotherapy was evaluated .The blood samples from 30 breast cancer patients before and after chemotherapy were collected; total RNA was extracted using Trizol and subsequently synthesized cDNA corresponding to circular RNA. Then, appropriate circular RNA primers were designed and SYBR Green real-time RT PCR was performed to evaluate the expression of circRNA in the presence of beta-actin as an appropriate internal control. The data statistically evaluated using Graph Pad Prism 8.2 software.
Results: The expression level of hsa_circ_0003227 in the blood sample of patients with breast cancer before chemotherapy has increased compared to the normal blood sample and also its expression in the blood sample of patients after chemotherapy has decreased compared to before chemotherapy.
Conclusion: The data revealed that hsa_circ_0003227 could potentially be proposed as a prognostic biomarker for breast cancer. Advanced related research in this field may be promising in cancer management.
Keywords: circRNA , breast cancer , hsa_circ_0003227, biomarker, Biological diagnosis, Noncoding RNA