RESUMEN
An in-depth understanding of circular RNAs (circRNAs) indicates that they are abundant in the eukaryotic transcriptome. Many circRNAs act as microRNA sponges; thus, they represent a new type of regulatory factor. However, the role of circRNA in colorectal cancer (CRC) remains largely unknown. Low circ_0021977 expression in patients with CRC is associated with higher tug-lymph node metastasis (TNM) stage and poorer prognosis compared with patients with high circ_0021977 expression. Moreover, miR-10b-5p was shown to be a target of circ_0021977, and p21 and p53 are suggested to be putative target genes of miR-10b-5p. The results showed that the circ_0021977/miR-10b-5p/p21&p53 regulatory axis suppresses proliferation, migration, and invasion by CRC cells. This evidence reveals new relationships and brings new highlights to the treatment of CRC.
RESUMEN
BACKGROUND: Circular RNAs (circRNAs), which have closed-loop structure, are involved in the pathogenesis of human diseases including various types of carcinomas. The present study aimed to investigate the relationship between a new circular RNA named circ_0066444 and gastric cancer (GC) carcinogenesis. MATERIALS AND METHODS: The circ_0066444 levels in 106 paired gastric carcinoma tissues and related adjacent normal tissues were detected by real-time quantitative reverse-transcription polymerase chain reaction. The correlation between the expression of circ_0066444 and clinicopathological features was analyzed. The impact of circ_0066444 expression on cell proliferation, invasion, as well as migration was evaluated in vitro using knockdown expression strategies. Finally, a network of circ_0066444-targeted miRNA interactions and their corresponding mRNAs was constructed. RESULTS: circ_0066444 was found to be significantly upregulated in 106 GC tissues as compared with paired adjacent nontumorous tissues (P=0.025), showing a high positive correlation with lymphatic metastasis (P=0.023). Furthermore, in vitro assays of the GC cell lines BGC-823 and AGS demonstrated that knockdown of circ_0066444 reduced cell proliferation, invasion, and migration significantly. Prediction and annotation revealed circ_0066444 was able to sponge to 5 miRNAs and 15 corresponding target mRNAs. CONCLUSION: Our study indicated upregulation of circ_0066444 promotes gastric cell proliferation, invasion, and migration ability and might serve as a novel biomarker for GC.
RESUMEN
Circular RNAs (circRNAs), a novel class of long noncoding RNAs, are characterized by a covalently closed continuous loop without 5' or 3' polarities structure and have been widely found in thousands of lives including plants, animals and human beings. Utilizing the high-throughput RNA sequencing (RNA-seq) technology, recent findings have indicated thata great deal of circRNAs, which are endogenous, stable, widely expressed in mammalian cells, often exhibit cell type-specific, tissue-specific or developmental-stage-specific expression. Evidences are arising that some circRNAs might regulate microRNA (miRNA) function as microRNA sponges and play a significant role in transcriptional control. circRNAs associate with related miRNAs and the circRNA-miRNA axes are involved in a serious of disease pathways such as apoptosis, vascularization, invasion and metastasis. In this review, we generalize and analyse the aspects including synthesis, characteristics, classification, and several regulatory functions of circRNAs and highlight the association between circRNAs dysregulation by circRNA-miRNA-mRNA axis and sorts of diseases including cancer- related and non-cancer diseases."