Circ_0000591 served as endogenous RNA for miR-326 to promote progression of cholangiocarcinoma via the TLR4/MyD88/IL6 axis

Circular RNA in cholangiocarcinoma: A systematic review and bibliometric analysis

BACKGROUND

Cholangiocarcinoma (CCA) is a common primary liver malignancy with a poor prognosis. Many studies have demonstrated the involvement of circular RNAs (circRNAs) in tumorigenesis and progression.

METHODS

Four online databases (PubMed, Web of Science, Embase, and Scopus) were searched on May 04, 2023, for original papers regarding CCA and circRNAs. Bibliometric analysis of included studies was performed on R Studio and GraphPad Prism.

RESULTS

Thirty studies were included in the systematic review and bibliometric analysis. The systematic review showed that circRNAs were involved in CCA proliferation, invasion, metastasis, chemotherapy resistance, and other biological processes and were related to the prognosis of patients and many clinicopathological features. Exosomal circRNAs provide a new idea for the early diagnosis of CCA. The bibliometric analysis showed a significant upward trend in the number of studies on CCA and circRNAs. The 30 included papers had 201 authors and were published in 22 English journals. The first paper was published in 2018, and the second paper was the most cited (148 citations).

CONCLUSION

This systematic review and bibliometric analysis demonstrates that circRNAs in CCA have not been studied enough. CircRNAs play an important role in the occurrence and progression of CCA. They may become new targets for the diagnosis, treatment, and prognostic monitoring of CCA.

The Role of TLR4 in the Immunotherapy of Hepatocellular Carcinoma: Can We Teach an Old Dog New Tricks?

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer and is a leading cause of cancer-related death worldwide. Immunotherapy has emerged as the mainstay treatment option for unresectable HCC. Toll-like receptor 4 (TLR4) plays a crucial role in the innate immune response by recognizing and responding primarily to bacterial lipopolysaccharides. In addition to its role in the innate immune system, TLR4 has also been implicated in adaptive immunity, including specific anti-tumor immune responses. In particular, the TLR4 signaling pathway seems to be involved in the regulation of several cancer hallmarks, such as the continuous activation of cellular pathways that promote cell division and growth, the inhibition of programmed cell death, the promotion of several invasion and metastatic mechanisms, epithelial-to-mesenchymal transition, angiogenesis, drug resistance, and epigenetic modifications. Emerging evidence further suggests that TLR4 signaling holds promise as a potential immunotherapeutic target in HCC. The aim of this review was to explore the multilayer aspects of the TLR4 signaling pathway, regarding its role in liver diseases and HCC, as well as its potential utilization as an immunotherapy target for HCC.

The interplay of signaling pathways with miRNAs in cholangiocarcinoma pathogenicity and targeted therapy

Cholangiocarcinoma (CCA), the second most frequent liver cancer after hepatocellular carcinoma, has been rising worldwide in recent epidemiological research. This neoplasia's pathogenesis is poorly understood. Yet, recent advances have illuminated the molecular processes of cholangiocyte malignancy and growth. Late diagnosis, ineffective therapy, and resistance to standard treatments contribute to this malignancy's poor prognosis. So, to develop efficient preventative and therapy methods, the molecular pathways that cause this cancer must be better understood. MicroRNAs (miRNAs) are non-coding ribonucleic acids (ncRNAs) that influence gene expression. Biliary carcinogenesis involves abnormally expressed miRNAs that act as oncogenes or tumor suppressors (TSs). The miRNAs regulate multiple gene networks and are involved in cancer hallmarks like reprogramming of cellular metabolism, sustained proliferative signaling, evasion of growth suppressors, replicative immortality, induction/access to the vasculature, activation of invasion and metastasis, and avoidance of immune destruction. In addition, numerous ongoing clinical trials are demonstrating the efficacy of therapeutic strategies based on miRNAs as powerful anticancer agents. Here, we will update the research on CCA-related miRNAs and explain their regulation involved in the molecular pathophysiology of this malignancy. Eventually, we will disclose their potential as clinical biomarkers and therapeutic tools in CCA.

Hsa_circ_0000591 drives osteosarcoma glycolysis and progression by sequestering miR-194-5p and elevating HK2 expression

Osteosarcoma (OS) is the most common bone tumour with a high risk of metastatic progression and recurrence after treatment. Circular RNA hsa_circ_0000591 (circ_0000591) plays a compelling role in OS aggressiveness. However, the function and regulatory mechanism of circ_0000591 need to be further elucidated. As a subject of this study, a differential circRNA circ_0000591 was screened by circRNA microarray expression profiling (GSE96964). Expression changes of circ_0000591 were detected using real-time quantitative polymerase chain reaction (RT-qPCR). Effects of circ_0000591 silencing on OS cell viability, proliferation, colony formation, apoptosis, invasion, and glycolysis were determined via functional experiments. The mechanism by which circ_0000591 functions as a molecular sponge for miRNAs was predicted using bioinformatics analysis and validated using dual-luciferase reporter and RNA pull-down assays. Xenograft assay was done to validate the function of circ_0000591. Circ_0000591 was strongly expressed in OS samples and cells. Silencing of circ_0000591 lessened cell viability, repressed cell proliferation, invasion, glycolysis, and promoted cell apoptosis. Importantly, circ_0000591 regulated HK2 expression by serving as a miR-194-5p molecular sponge. MiR-194-5p silencing impaired circ_0000591 downregulation-mediated suppression of OS cell malignancy and glycolysis. HK2 overexpression weakened the inhibiting impacts of miR-194-5p on OS cell malignancy and glycolysis. Also, circ_0000591 silencing decreased xenograft tumour growth in vivo. Circ_0000591 drove OS glycolysis and growth by upregulating HK2 by sequestering miR-194-5p. The study highlighted the tumour-promoting function of circ_0000591 in OS.

A review on the role of ncRNAs in the pathogenesis of cholangiocarcinoma

Cholangiocarcinoma is a rare tumor but a challenging cancer in terms of pathological changes, clinical manifestations and therapeutic options. Recent studies have provided evidence for participation of non-coding RNAs in the carcinogenic process of cholangiocarcinoma. We demonstrate the role of long non-coding RNAs, microRNAs and circular RNAs in the pathogenesis of cholangiocarcinoma and highlight their significant position as therapeutic targets and biomarkers for this type of cancer. We also list a number of molecular axes comprising these non-coding RNAs that represent potential targets for therapeutic options in cholangiocarcinoma, based on their significant roles in the regulation of cell proliferation, differentiation and apoptosis of these cells.

The expression profiles of circular RNAs and competing endogenous RNA networks in intrahepatic cholangiocarcinoma

Introduction: Intrahepatic cholangiocarcinoma (iCCA) is a heterogeneous entity with diverse etiologies, morphologies, and clinical outcomes, but our knowledge of its epidemiology and carcinogenesis is very limited. Materials and methods: The expression patterns of circRNAs were explored in iCCA tissues and corresponding adjacent normal ones, denoted by (iCCA) and (iCCAP), respectively, using high-throughput sequencing. Results: A total of 117 differential expressed (DE) circRNAs were identified. Based on the parental transcripts of circRNAs, these DE circRNAs were related to several important GO terms and were enriched in important pathways. Two circRNA-mediated ceRNA networks were constructed and many important metabolic pathways related to mRNAs were regulated by DE circRNAs via miRNAs. Conclusion: Our study revealed the DE circRNAs in the iCCA tissues compared with iCCAP ones, suggesting that circRNAs may play crucial roles in the pathogenesis of iCCA.