Construction of a m5C-related long non-coding RNA signature for the prognosis of hepatocellular carcinoma

Clinical significance of RNA methylation in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a primary liver malignancy with high mortality rates and poor prognosis. Recent advances in high-throughput sequencing and bioinformatic technologies have greatly enhanced the understanding of the genetic and epigenetic changes in liver cancer. Among these changes, RNA methylation, the most prevalent internal RNA modification, has emerged as a significant contributor of the development and progression of HCC. Growing evidence has reported significantly abnormal levels of RNA methylation and dysregulation of RNA-methylation-related enzymes in HCC tissues and cell lines. These alterations in RNA methylation play a crucial role in the regulation of various genes and signaling pathways involved in HCC, thereby promoting tumor progression. Understanding the pathogenesis of RNA methylation in HCC would help in developing prognostic biomarkers and targeted therapies for HCC. Targeting RNA-methylation-related molecules has shown promising potential in the management of HCC, in terms of developing novel prognostic biomarkers and therapies for HCC. Exploring the clinical application of targeted RNA methylation may provide new insights and approaches for the management of HCC. Further research in this field is warranted to fully understand the functional roles and underlying mechanisms of RNA methylation in HCC. In this review, we described the multifaceted functional roles and potential mechanisms of RNA methylation in HCC. Moreover, the prospects of clinical application of targeted RNA methylation for HCC management are discussed, which may provide the basis for subsequent in-depth research on RNA methylation in HCC.

Long non-coding RNAFOXD1-AS1 modulated CTCs epithelial-mesenchymal transition and immune escape in hepatocellular carcinoma in vitro by sponging miR-615-3p

BACKGROUND

Hepatocellular carcinoma (HCC) is widely recognized as a globally prevalent malignancy. Immunotherapy is a promising therapy for HCC patients. Increasing evidence suggests that lncRNAs are involved in HCC progression and immunotherapy.

AIM

The study reveals the mechanistic role of long non-coding RNA (lncRNA) FOXD1-AS1 in regulating migration, invasion, circulating tumor cells (CTCs), epithelial-mesenchymal transition (EMT), and immune escape in HCC in vitro.

METHODS

This study employed real-time PCR (RT-qPCR) to measure FOXD1-AS1, miR-615-3p, and programmed death-ligand 1 (PD-L1). The interactions of FOXD1-AS1, miR-615-3p, and PD-L1 were validated via dual-luciferase reporter gene and ribonucleoprotein immunoprecipitation (RIP) assay. In vivo experimentation involves BALB/c mice and BALB/c nude mice to investigate the impact of HCC metastasis.

RESULTS

The upregulation of lncRNA FOXD1-AS1 in malignant tissues significantly correlates with poor prognosis. The investigation was implemented on the impact of lncRNA FOXD1-AS1 on the migratory, invasive, and EMT of HCC cells. It has been observed that the lncRNA FOXD1-AS1 significantly influences the generation and metastasis of MCTC in vivo analysis. In mechanistic analysis, lncRNA FOXD1-AS1 enhanced immune escape in HCC via upregulation of PD-L1, which acted as a ceRNA by sequestering miR-615-3p. Additionally, lncRNA FOXD1-AS1 was found to modulate the EMT of CTCs through the activation of the PI3K/AKT pathway.

CONCLUSION

This study presents compelling evidence supporting the role of lncRNA FOXD1-AS1 as a miRNA sponge that sequesters miR-655-3p and protects PD-L1 from suppression.

RNA 5-methylcytosine writer NSUN5 promotes hepatocellular carcinoma cell proliferation via a ZBED3-dependent mechanism

Hepatocellular carcinoma (HCC) is one of the leading contributors to cancer-related mortality worldwide. Nop2/Sun domain family member 5 (NSUN5), a conserved RNA 5-methylcytosine methyltransferase, is conventionally recognized as oncogenic. However, its role in HCC development remains unknown. In this study, we observed a remarkable upregulation of NSUN5 expression in both tumor tissues from patients with HCC, establishing a correlation with unfavorable clinical outcomes. NSUN5 knockdown and overexpression significantly inhibited and promoted HCC cell proliferation, respectively. Additionally, employing a combination of methylated RNA immunoprecipitation sequencing (MeRIP-seq) and RIP-seq techniques, we identified zinc finger BED domain-containing protein 3 (ZBED3) as a novel downstream target of NSUN5. Additionally, we found that the overexpression of ZBED3 counteracted the tumor-suppressing effect of NSUN5 knockdown and simultaneously reversed the inhibition of the Wnt/β-catenin signaling pathway. In summary, we elucidated the oncogenic role of NSUN5 in HCC development and identified the ZBED3/Wnt/β-catenin signaling pathway as its downstream target. This study provides a novel therapeutic target for further development in HCC treatment.

Understanding the Epitranscriptome for Avant-Garde Brain Tumour Diagnostics

RNA modifications are diverse, dynamic, and reversible transcript alterations rapidly gaining attention due to their newly defined RNA regulatory roles in cellular pathways and pathogenic mechanisms. The exciting emerging field of 'epitranscriptomics' is predominantly centred on studying the most abundant mRNA modification, N6-methyladenine (m⁶A). The m⁶A mark, similar to many other RNA modifications, is strictly regulated by so-called 'writer', 'reader', and 'eraser' protein species. The abundance of genes coding for the expression of these regulator proteins and m⁶A levels shows great potential as diagnostic and predictive tools across several cancer fields. This review explores our current understanding of RNA modifications in glioma biology and the potential of epitranscriptomics to develop new diagnostic and predictive classification tools that can stratify these highly complex and heterogeneous brain tumours.