Emerging Function and Clinical Significance of hsa_circ_0065173 in peripheral blood of breast cancer patients pre and post chemotherapy in order to find potential biomarker related to response to treatment

Emerging Function and Clinical Significance of hsa_circ_0065173 in peripheral blood of breast cancer patients pre and post chemotherapy in order to find potential biomarker related to response to treatment
Dina Ehsani,¹ Mahdieh Salimi ,^2,* Iman Salahshourifar,³
1. Department of biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
2. Department of medical genetics, institute of medical biotechnology, national institute of genetic engineering and biotechnology (NIGEB)
3. Department of biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
Introduction: Breast cancer remains one of the most frequently diagnosed gynecological malignancies, currently accounting for 29% of all new cancer cases, and is the second leading cause of cancer-associated mortality in females all over the world. Early diagnosis, radical surgery and adjuvant therapy have improved the survival rates and prognosis of breast cancer patients, however mortality rates remain high. In order to maximize the effectiveness of therapy, it is important to understand the molecular pathways involved in the pathogenesis of breast cancer that cause metastasis and chemotherapy resistance. Recently, high-throughput transcriptome analysis shows that protein-coding genes make up only about 2% of the human genome, while the vast majority of the human genome encodes large amounts of noncoding RNAs (ncRNAs) that includes: long non-coding RNA (lncRNA) , micro RNA (miRNA), and circular RNA (circRNA), which are characterized by covalent closed loops. CircRNA are formed by back-splicing without 3’-end and 5’-end, unlike lncRNA. Circular RNA (circRNA) is a key regulator in the development and progression of human cancers, however its role in breast cancer tumorigenesis is not well understood. The present study aims to investigate the expression profiles and potential modulation of hsa_circ_0065173 in peripheral blood of breast cancer patients pre and post-chemotherapy in order to find the potential biomarkers related to treatment response.
Methods: Total RNA was isolated from the peripheral blood samples before and after chemotherapy using TRIzol reagent following the manufacturer’s protocol. RNA was reverse transcribed into cDNA using M-MLV Reverse Transcriptase. SYBR Green Real-time RT PCR using special primers for circ-RNA hsa_circ_0065173 and beta-actin as an internal control was performed. All the values were standardized with 2-∆∆Ct method and statically analyzed using Graph Pad Prism 8.2 software.
Results: hsa_circ_0065173 was upregulated in peripheral blood samples of breast cancer patients compared with normal control. In addition, hsa_circ_0065173 upregulation was associated with lymph node involvement. After receiving the first dose of chemotherapy, the expression level of hsa_circ_0065173 decreased significantly.
Conclusion: In conclusion, hsa_circ_0065173 has an oncogenic function and correlates with advanced clinicopathological features and unfavorable survival. hsa_circ_0065173 might function as a prognostic biomarker for breast cancer patients pre and post-chemotherapy and might be a therapeutic target for the treatment of breast cancer in the future. Advanced related researches will be promising in cancer management.
Keywords: Breast cancer, hsa_circ_0065173 , chemotherapy, prognostic biomarker