CircBIRC۶: A Circular Non-Coding RNAAssociated with Pluripotency Exhibits Differential Expressionin Stem Cells and Tumor Cells

Background: Most breast and stomach cancer patients are diagnosedat an advanced stage due to the heterogeneity of the diseaseand the lack of appropriate biomarkers. As pluripotent stemcells are linked to tumorigenesis and also given the significantrole of circular non-coding RNAs (circRNAs) in carcinogenesis,the aim of this study was to compare the expression of circularRNAs derived from the baculoviral IAP Repeat Containing ۶gene (circBIRC۶: hsa_circ_۰۰۰۳۲۸۸ and hsa_circ_۰۰۰۰۹۸۹) incancer cell lines with pluripotent stem cells. By targeting mir-۱۴۵ and mir-۳۲a, CircBIRC۶ contributes to the maintenance ofpluripotency genes such as OCT۴ and NANOG.Materials and Methods: Total RNA was isolated from mesenchymalstem cells (MSCs), NT۲ embryonal carcinoma (NT۲),breast cancer cell lines (MDA-MB۲۳۱ and MCF۷), gastric cancercell lines (AGS and MKN۴۵), and human-induced stem cells(hiPSCs, NP۰۰۴۱-۱۷). Real-time reverse transcription PCR wasconducted using the SYBR Green master mix.Results: The expression of hsa_circ_۰۰۰۳۲۸۸ was higher in hiPSCand MSCs rather than in gastric cancer cell lines and NT۲.The hsa_circ_۰۰۰۰۹۸۹ showed the same result just for hiPSC.Although, both isoforms showed an increased expression level inbreast cancer cell lines compared to hiPSC and MSCs.Conclusion: Compared to stem cells, gastric cancer cell linesexpress circBIRC۶ less frequently. The result was consistentwith previous research showing that pluripotency-relatedgenes, including OCT۴, SOX۲, and LncRNA-SOX۲, are lessexpressed in adenocarcinomas than in non-cancerous tumors.Breast cancer cell lines displayed a higher level of expressionthan stem cells and gastric cancer cell lines, therefore it seemsthe circBIRC۶ expression depends on the origin of cancer andtumor cell lines.

کلیدواژه ها:

gastric and breast cancer cell line ، stem cell ، circularnon coding RNAs (circncRNAs) ، circBIRC۶ ، pluripotency