Altered expression pattern of circular RNAs in primary and metastatic sites of epithelial ovarian carcinoma.
Recently, a class of endogenous species of RNA called circular RNA (circRNA) has been shown to regulate gene expression in mammals and their role in cellular function is just beginning to be understood. To investigate the role of circRNAs in ovarian cancer, we performed paired-end RNA sequencing of primary sites, peritoneal and lymph node metastases from three patients with stage IIIC ovarian cancer. We developed an in-house computational pipeline to identify and characterize the circRNA expression from paired-end RNA-Seq libraries. This pipeline revealed thousands of circular isoforms in Epithelial Ovarian Carcinoma (EOC). These circRNAs are enriched for potentially effective miRNA seed matches. A significantly larger number of circRNAs are differentially expressed between tumor sites than mRNAs. Circular and linear expression exhibits an inverse trend for many cancer related pathways and signaling pathways like NFkB, PI3k/AKT and TGF-β typically activated for mRNA in metastases are inhibited for circRNA expression. Further, circRNAs show a more robust expression pattern across patients than mRNA forms indicating their suitability as biomarkers in highly heterogeneous cancer transcriptomes. The consistency of circular RNA expression may offer new candidates for cancer treatment and prognosis.
Department of Genetic Medicine, Weill Cornell Medicine-Qatar, Education City, Ar-Rayyan, Qatar.
Ikhlak
I
Ahmed
Department of Genetic Medicine, Weill Cornell Medicine-Qatar, Education City, Ar-Rayyan, Qatar.
Thasni
T
Karedath
Department of Genetic Medicine, Weill Cornell Medicine-Qatar, Education City, Ar-Rayyan, Qatar.
Simeon S
SS
Andrews
Genomics Core, Weill Cornell Medicine-Qatar, Education City, Ar-Rayyan, Qatar.
Iman K
IK
Al-Azwani
Genomics Core, Weill Cornell Medicine-Qatar, Education City, Ar-Rayyan, Qatar.
Yasmin Ali
YA
Mohamoud
Department of Gynecologic Oncology, Université Montepllier 1, Montpellier, France.
Denis
D
Querleu
Stem Cell and Microenvironment Laboratory, Weill Cornell Medicine-Qatar, Education City, Ar-Rayyan, Qatar.
Arash
A
Rafii
Department of Genetic Medicine, Weill Cornell Medicine-Qatar, Education City, Ar-Rayyan, Qatar.|Genomics Core, Weill Cornell Medicine-Qatar, Education City, Ar-Rayyan, Qatar.
Joel A
JA
Malek
D000077216:Carcinoma, Ovarian Epithelial; D005260:Female; D020869:Gene Expression Profiling / Q000379:methods*; D015972:Gene Expression Regulation, Neoplastic; D053263:Gene Regulatory Networks; D006801:Humans; D035683:MicroRNAs / Q000235:genetics; D009362:Neoplasm Metastasis; D009375:Neoplasms, Glandular and Epithelial / Q000235:genetics* / Q000473:pathology; D010051:Ovarian Neoplasms / Q000235:genetics* / Q000473:pathology; D012313:RNA / Q000235:genetics*; D000079962:RNA, Circular; D017423:Sequence Analysis, RNA / Q000379:methods; D015398:Signal Transduction / Q000235:genetics
D035683:MicroRNAs; D000079962:RNA, Circular; D012313:RNA
circular RNA; lymph node metastasis; miRNA; ovarian cancer; peritoneal metastasis