Circular RNA Circ_0008043 promotes the proliferation and metastasis of hepatocellular carcinoma cells by regulating the microRNA (miR)-326/RAB21 axis

Hepatocellular Carcinoma: Up-regulated Circular RNAs Which Mediate Efficacy in Preclinical In Vivo Models

Hepatocellular carcinoma (HCC) ranges as number two with respect to the incidence of tumors and is associated with a dismal prognosis. The therapeutic efficacy of approved multi-tyrosine kinase inhibitors and checkpoint inhibitors is modest. Therefore, the identification of new therapeutic targets and entities is of paramount importance. We searched the literature for up-regulated circular RNAs (circRNAs) which mediate efficacy in preclinical in vivo models of HCC. Our search resulted in 14 circRNAs which up-regulate plasma membrane transmembrane receptors, while 5 circRNAs induced secreted proteins. Two circRNAs facilitated replication of Hepatitis B or C viruses. Three circRNAs up-regulated high mobility group proteins. Six circRNAs regulated components of the ubiquitin system. Seven circRNAs induced GTPases of the family of ras-associated binding proteins (RABs). Three circRNAs induced redox-related proteins, eight of them up-regulated metabolic enzymes and nine circRNAs induced signaling-related proteins. The identified circRNAs up-regulate the corresponding targets by sponging microRNAs. Identified circRNAs and their targets have to be validated by standard criteria of preclinical drug development. Identified targets can potentially be inhibited by small molecules or antibody-based moieties and circRNAs can be inhibited by small-interfering RNAs (siRNAs) or short hairpin RNAs (shRNAs) for therapeutic purposes.

Tumor Microenvironment Remodeling in Gastrointestinal Cancer: Role of miRNAs as Biomarkers of Tumor Invasion

Gastrointestinal (GI) cancers are the most frequent neoplasm, responsible for half of all cancer-related deaths. Metastasis is the leading cause of death from GI cancer; thus, studying the processes that regulate cancer cell migration is of paramount importance for the development of new therapeutic strategies. In this review, we summarize the mechanisms adopted by cancer cells to promote cell migration and the subsequent metastasis formation by highlighting the key role that tumor microenvironment components play in deregulating cellular pathways involved in these processes. We, therefore, provide an overview of the role of different microRNAs in promoting tumor metastasis and their role as potential biomarkers for the prognosis, monitoring, and diagnosis of GI cancer patients. Finally, we relate the possible use of nutraceuticals as a new strategy for targeting numerous microRNAs and different pathways involved in GI tumor invasiveness.

Circular RNA circRNA-0039459 promotes the migration, invasion, and proliferation of liver cancer cells through the adsorption of miR-432

This study aimed to investigate the molecular mechanism of circular RNA circ-0039459 and its effects on the apoptosis, proliferation, invasion, and migration of hepatocellular carcinoma cells. The expression of circ-0039459, miR-432, and synoviolin 1 (SYVN1) mRNA was determined using real-time quantitative reverse transcription PCR. Cell proliferation was detected by cell counting kit-8 assay, and the apoptosis rate was detected using flow cytometry. Cell migration and invasion were detected using Transwell assay. The expression of E-cadherin, N-cadherin, and vimentin was detected using western blot. The targeting relationship between circ-0039459 and miR-432 as well as that between miR-432 and SYVN1 were detected using the dual-luciferase reporter and RNA pull-down assays. We found that circ-0039459 and SYVN1 mRNA were highly expressed, whereas miR-432 was lowly expressed in hepatocellular carcinoma cells and tissues. After treatment with ribonuclease R or actinomycin D, the expression of linear RNA was reduced, whereas that of circular RNA was not significantly changed. circ-0039459 knockdown or miR-432 overexpression can inhibit cell proliferation, invasion, and migration and the expression of N-cadherin and vimentin proteins in carcinoma cells as well as promote apoptosis and increase the E-cadherin level. circ-0039459 targeted and regulated miR-432, which targeted and regulated SYVN1. The decreased miR-432 expression reversed the effects of circ-0039459 knockout in cancer cells. Furthermore, SYVN1 overexpression reversed the effect of miR-432 overexpression in hepatoma cells. Hence, circ-0039459 can affect the proliferation, apoptosis, migration, and invasion of hepatocellular carcinoma cells through the adsorption of miR-432, thereby regulating the expression of SYVN1.