Project description:Background: circRNAs, a recently identified new member of non-coding RNAs, have been proved to play an essential role in the development and progression of various cancers. However, the functions and mechanisms of circRNAs in colorectal liver metastasis have not been fully elucidated. Methods: We performed circRNA microarray to screen differentially expressed novel circRNAs in the pathology of colorectal liver metastasis. Quantitative real-time PCR was used to detect the circ102049 expression in colorectal cancer (CRC) samples. Then CRC cells were transfected with a circ102049 over-expression vector or siRNAs, and the effects of circ102049 on biological functions in CRC cells were accessed in vitro. Mechanistically, the bioinformatics analysis, fluorescence in situ hybridization, RIP assay, RNA pull down assay and luciferase reporter assay were conducted to confirm the relationships among circ102049, miR-761, miR-192-3p and FRAS1. Moreover, the mechanism of circ102049 how to recruit and distribute DGCR8 protein in cytoplasm was elucidated. Results: The results showed that circ102049 was highly expressed in primary CRC tumors with liver metastasis and closely correlated with the CRC patients' prognosis. Circ102049 might act as a novel metastasis-related non-coding RNA, and significantly promote the adhesion, migration and invasion abilities of CRC cells. Mechanistically, we verified that circ102049 promoted the CRC development and progression via a miR-761/miR-192-3p-FRAS1-dependent mechanism. Notably, due to the distribution of DGCR8 protein, circ102049 might also reduce the mature products of miR-761 and miR-192-3p in cytoplasm indirectly. In addition, the role of circ102049 in promoting colorectal liver metastasis was also confirmed in vivo. Conclusions: Our findings provided new clues that circ102049 might be a potential prognostic factor in CRC, and the circ102049-miR-761/miR-192-3p-FRAS1 axis could be further explored as a therapeutic target for anti-metastatic therapy in CRC patients with liver metastases. Keywords: Hsa_circ_102049, miR-761, miR-192-3p, FRAS1, Colorectal liver metastasis
Project description:Circular RNAs (circRNAs) represent critical roles in the biology of various cancers. However, their expression patterns and biological functions in human colorectal cancer (CRC) remain largely unknown. The aim of this study was to explore circRNAs profiles in CRC and investigate key circRNAs involved in CRC tumourigenesis and progression.
Project description:Colorectal cancer(CRC)is a commonly diagnosed cancer of the digestive system worldwide. Although chemotherapeutic agents and targeted therapeutic drugs are currently available for CRC treatment, drug resistance is a problem that cannot be ignored and needs to be solved. 5-Fluorouracil (5-Fu) is a first-line chemotherapeutic agent for colorectal cancer, to explore the role of circular RNA (circRNA) in 5-Fu resistance, we performed the circRNA expression profile in two CRC cell lines and their homologous 5-Fu resistant cells by high-throughput sequencing. We validated the differentially expressed circRNAs in other two paired CRC cells, confirmed that circ_0002813 and circ_0000236 could have a potential ceRNA mechanism and be involved in the formation of 5-Fu resistance. And we combined the sequencing results of mRNA to construct the regulatory network of circRNA-miRNA-mRNA. Our study revealed that circ_0002813 and circ_0000236 may as the biomarkers to predict the occurrence of 5-Fu resistance in CRC.
Project description:There is already strong evidence indicating that different types of non-coding RNAs, including microRNAs (miRNAs) and long non-coding RNAs, are key players in the regulation of β-cell functions and in the development of diabetes. However, the role of the newly discovered class of circular RNAs remains to be elucidated. We therefore analysed circular RNA expression in human islet samples.