YY1-Targeted RBM15B Promotes Hepatocellular Carcinoma Cell Proliferation and Sorafenib Resistance by Promoting TRAM2 Expression in an m6A-Dependent Manner

PSMD14 Transcriptionally Activated by MEF2A Promotes Pancreatic Cancer Development by Upregulating SPON2 Expression

Proteasome 26S subunit non-ATPase 14 (PSMD14) plays a pro-carcinogenic role in various cancers. However, its specific effects and mechanisms in pancreatic cancer (PC) remain unclear. We aimed to assess the function and mechanism of PSMD14 in PC. Fifteen paired pancreatic ductal adenocarcinoma (PDAC) tissues and adjacent non-tumorous tissues were clinically obtained. Cell proliferation, migration, and invasion were assessed using colony formation, scratch, and Transwell assays. The interaction between the MEF2A transcription factor and the PSMD14 promoter verified by chromatin immunoprecipitation (ChIP) or dual luciferase assay. The interaction between RBM15B and SPON2 mRNA was validated by RNA immunoprecipitation (RIP) assay. The interaction between the proteins PSMD14 and RBM15B was detected by co-immunoprecipitation (Co-IP) assay. The m6A level of SPON2 was detected by methylated RNA immunoprecipitation (MeRIP, a common method for detecting m6A levels of mRNAs). The ubiquitination level of RNA-binding motif protein 15B (RBM15B) was detected using Co-IP. The role of PSMD14 in PC was further explored subcutaneous and lung metastasis models. PSMD14 was upregulated in PDAC tissues. PSMD14 knockdown inhibited PC cell viability, proliferation, migration, and invasion. MEF2A transcriptionally activated PSMD14 expression. PSMD14 knockdown promoted the ubiquitination degradation of RBM15B. Additionally, PSMD14 enhanced SPON2 mRNA stability through RBM15B-mediated m6A modification. SPON2 overexpression impaired the effect of knockdown PSMD14. Finally, PSMD14 knockdown in PC arrested tumor growth and lung metastasis. PSMD14, transcriptionally activated by MEF2A, promotes the de-ubiquitination of RBM15B, which upregulates SPON2 expression in an m6A-RBM15B-dependent manner, thereby facilitating PC proliferation, migration, and invasion.

Exploring RNA binding proteins in hepatocellular carcinoma: insights into mechanisms and therapeutic potential

Hepatocellular carcinoma (HCC), the most prevalent type of primary liver cancer, is linked to elevated global incidence and mortality rates. Elucidating the intricate molecular pathways that drive the progression of HCC is imperative for devising targeted and effective therapeutic interventions. RNA-binding proteins (RBPs) serve as pivotal regulators of post-transcriptional processes, influencing various cellular functions. This review endeavors to provide a comprehensive analysis of the expression, function, and potential implications of RBPs in HCC. We discuss the classification and diverse roles of RBPs, with a particular focus on key RBPs implicated in HCC and their association with disease progression. Additionally, we explore the mechanisms by which RBPs contribute to HCC, including their impact on gene expression, cell proliferation, cell metastasis, angiogenesis, signaling pathways, and post-transcriptional modifications. Importantly, we examine the potential of RBPs as therapeutic targets and prognostic biomarkers, offering insights into their relevance in HCC treatment. Finally, we outline future research directions, emphasizing the need for further investigation into the functional mechanisms of RBPs and their clinical translation for personalized HCC therapy. This comprehensive review highlights the pivotal role of RBPs in HCC and their potential as novel therapeutic avenues to improve patient outcomes.

RBM15B Promotes Prostate Cancer Cell Proliferation via PCNA m6A Modification

Prostate cancer (PC) is the most frequently occurring cancer in men, characterized by the abnormal proliferation of cells within the prostate gland. This study explores the role of RNA binding motif protein 15B (RBM15B) in PC. RBM15B expression levels in PC patients were predicted using the Starbase database. The expression of RBM15B and proliferating cell nuclear antigen (PCNA) expression in PC cells was detected. Following RBM15B knockdown, cell proliferation assays were conducted. N6-methyladenosine (m6A) levels in PC cells were quantified, and RNA immunoprecipitation was performed to analyze the binding of m6A and YTH N-methyladenosine RNA binding protein 1 (YTHDF1) on PCNA mRNA. The stability of PCNA mRNA was assessed after treatment with actinomycin D. An in vivo nude mouse xenograft model was created to validate the role of RBM15B. The findings revealed the upregulation of RBM15B in PC. RBM15B knockdown resulted in decreased proliferation, colony formation, and EdU-positive cells. Mechanical analysis showed that RBM15B facilitated m6A modification of PCNA mRNA, leading to increasing m6A methylation. YTHDF1 bound to these m6A sites on PCNA mRNA, thus stabilizing it. Furthermore, PCNA overexpression mitigated the effects of RBM15B knockdown on PC cell proliferation. In conclusion, RBM15B promotes PC cell proliferation by enhancing the stability of PCNA mRNA through YTHDF1-mediated m6A modification.

Epitranscriptomic RNA m6A Modification in Cancer Therapy Resistance: Challenges and Unrealized Opportunities

Significant advances in the development of new cancer therapies have given rise to multiple novel therapeutic options in chemotherapy, radiotherapy, immunotherapy, and targeted therapies. Although the development of resistance is often reported along with temporary disease remission, there is often tumor recurrence of an even more aggressive nature. Resistance to currently available anticancer drugs results in poor overall and disease-free survival rates for cancer patients. There are multiple mechanisms through which tumor cells develop resistance to therapeutic agents. To date, efforts to overcome resistance have only achieved limited success. Epitranscriptomics, especially related to m6A RNA modification dysregulation in cancer, is an emerging mechanism for cancer therapy resistance. Here, recent studies regarding the contributions of m6A modification and its regulatory proteins to the development of resistance to different cancer therapies are comprehensively reviewed. The promise and potential limitations of targeting these entities to overcome resistance to various anticancer therapies are also discussed.

Functions and mechanisms of RNA m6A regulators in breast cancer (Review)

Breast cancer (BC) is a major malignant tumor in females and the incidence rate of BC has increased worldwide in recent years. N6‑methyladenosine (m6A) is a methylation modification that occurs extensively in eukaryotic RNA. The abnormal expression of m6A and related regulatory proteins can activate or inhibit certain signal pathways or oncogenes, thus affecting the proliferation, metastasis and prognosis of BC. Numerous studies have shown that m6A regulator disorder exists in BC, and this disorder can be reversed. Therefore, m6A is predicted as a potential therapeutic target for BC. However, the molecular mechanism of m6A RNA methylation regulating the occurrence and development of BC has not been comprehensively elucidated. In this review article, the functions of various m6A regulators and the specific mechanisms of certain regulators of the progress of BC were summarized. Furthermore, the dual role of RNA methylation in tumor progression was discussed, concluding that RNA methylation can not only lead to tumorigenesis but at times give rise to inhibition of tumor formation. In addition, further comprehensive analysis on mechanisms of m6A regulators in BC is conducive to screening effective potential targets and formulating targeted treatment strategies, which will provide new methods for the prevention and treatment of BC.

YY1 mediated DCUN1D5 transcriptional activation promotes triple-negative breast cancer progression by targeting FN1/PI3K/AKT pathway

Triple-negative breast cancer (TNBC) is more aggressive and has a higher metastasis rate compared with other subtypes of breast cancer. Due to the lack of drug-targetable receptors, chemotherapy is now the only available systemic treatment for TNBC. However, some patients might still develop drug resistance and have poor prognosis. Therefore, novel molecular biomarkers and new treatment targets are urgently needed for patients with TNBC. To provide molecular insights into TNBC progression, we investigated the function and the underlying mechanism of Defective in cullin neddylation 1 domain containing 5 (DCUN1D5) in the regulation of TNBC. By TCGA dataset and surgical specimens with immunohistochemical (IHC) staining method, DCUN1D5 was identified to be significantly upregulated in TNBC tumor tissues and negatively associated with prognosis. A series of in vitro and in vivo experiments were performed to confirm the oncogenic role of DCUN1D5 in TNBC. Overexpression of FN1 or PI3K/AKT activator IGF-1 could restore the proliferative and invasive ability induced by DCUN1D5 knockdown and DCUN1D5 could act as a novel transcriptional target of transcription factor Yin Yang 1 (YY1). In conclusion, YY1-enhanced DCUN1D5 expression could promote TNBC progression by FN1/PI3K/AKT pathway and DCUN1D5 might be a potential prognostic biomarker and therapeutic target for TNBC treatment.

Identification and validation of an H2AZ1-based index model: a novel prognostic tool for hepatocellular carcinoma

The H2A.Z variant histone 1 (H2AZ1) is aberrantly expressed in various tumors, correlating with an unfavorable prognosis. However, its role in hepatocellular carcinoma (HCC) remains unclear. We aimed to elucidate the pathways affected by H2AZ1 and identify promising therapeutic targets for HCC. Following bioinformatic analysis of gene expression and clinical data from The Cancer Genome Atlas and Gene Expression Omnibus database, we found 6,344 dysregulated genes related to H2AZ1 overexpression in HCC tissues (P < 0.05). We performed weighted gene co-expression network analysis to identify the gene module most related to H2AZ1. The H2AZ1-based index was further developed using Cox regression analysis, which revealed that the poor prognosis in the high H2AZ1-based index group could be attributed to elevated tumor stemness (P < 0.05). Moreover, the clinical model showed good prognostic potential (AUC > 0.7). We found that H2AZ1 knockdown led to reduced superoxide dismutase (SOD) activity, elevated malondialdehyde (MDA) levels, and increased apoptosis rate in tumor cells (P < 0.001). Thus, we developed an H2AZ1-based index model with the potential to predict the prognosis of patients with HCC. Our findings provide initial evidence that H2AZ1 overexpression plays a pivotal role in HCC initiation and progression.

Comprehensive analysis reveals TSEN54 as a robust prognosis biomarker and promising immune-related therapeutic target for hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma represents the most common primary malignancy of all liver cancer types and its prognosis is usually unsatisfactory. TSEN54 encodes a protein constituting a subunit of the tRNA splicing endonuclease heterotetramer. Previous researches concentrated on the contribution of TSEN54 in pontocerebellar hypoplasia, but no studies have yet reported its role in HCC.

METHODS

TIMER, HCCDB, GEPIA, HPA, UALCAN, MEXPRESS, SMART, TargetScan, RNAinter, miRNet, starBase, Kaplan-Meier Plotter, cBioPortal, LinkedOmics, GSEA, TISCH, TISIDB, GeneMANIA, PDB, GSCALite were applied in this research.

RESULTS

We identified the upregulation of TSEN54 expression in HCC and related it to multiple clinicopathological features. Hypomethylation of TSEN54 was closely associated with its high expression. HCC sufferers who held high TSEN54 expression typically had shorter survival expectations. Enrichment analysis showed the involvement of TSEN54 in the cell cycle and metabolic processes. Afterward, we observed that TSEN54 expression level had a positive relationship to the infiltration level of multiple immune cells and the expression of several chemokines. We additionally identified that TSEN54 was related to the expression level of several immune checkpoints and TSEN54 was linked to several m6A-related regulators.

CONCLUSIONS

TSEN54 is a prognostic marker of HCC. TSEN54 could become a prospective candidate for HCC diagnosis and therapy.

Emerging roles of m6A RNA modification in cancer therapeutic resistance

Marvelous advancements have been made in cancer therapies to improve clinical outcomes over the years. However, therapeutic resistance has always been a major difficulty in cancer therapy, with extremely complicated mechanisms remain elusive. N6-methyladenosine (m6A) RNA modification, a hotspot in epigenetics, has gained growing attention as a potential determinant of therapeutic resistance. As the most prevalent RNA modification, m6A is involved in every links of RNA metabolism, including RNA splicing, nuclear export, translation and stability. Three kinds of regulators, "writer" (methyltransferase), "eraser" (demethylase) and "reader" (m6A binding proteins), together orchestrate the dynamic and reversible process of m6A modification. Herein, we primarily reviewed the regulatory mechanisms of m6A in therapeutic resistance, including chemotherapy, targeted therapy, radiotherapy and immunotherapy. Then we discussed the clinical potential of m6A modification to overcome resistance and optimize cancer therapy. Additionally, we proposed existing problems in current research and prospects for future research.

N6-Methyladenosine regulator RBM15B acts as an independent prognostic biomarker and its clinical significance in uveal melanoma

Uveal melanoma (UM) is the most frequent intraocular malignant tumor in adults. N⁶-Methyladenosine (m⁶A) methylation is recognized as the most critical epigenetic change and is implicated in the development of many malignancies. However, its prognostic value in UM is poorly understood. RNA-seq and clinical data from The Cancer Genome Atlas (TCGA) help us better understand the relationship between m⁶A regulators and UM patients. Herein, four UM groups established by consensus clustering were shown to have different immune cell infiltrations and prognostic survival. Five m⁶A regulators, including RBM15B, IGF2BP1, IGF2BP2, YTHDF3, and YTHDF1, were associated with the prognosis of UM patients. Intriguingly, RBM15B was confirmed to be the only independent prognostic factor for UM and it was significantly correlated with clinicopathologic characteristics of UM. Notably, RBM15B expression was significantly negatively correlated with immune checkpoints. Furthermore, LINC00665/hsa-let-7b-5p/RBM15B axis and LINC00638/hsa-miR-103a-3p/RBM15B axis were found to be potential prognostic biomarkers in UM. In a nutshell, this work, through bioinformatics analysis, systematically described the gene signatures and prognostic values of m⁶A regulators. RBM15B is an independent protective prognostic factor, which may help us better understand the crosstalk within UM.

Comprehensive analysis of the prognosis and immune infiltration landscape of RNA methylation-related subtypes in pancreatic cancer

BACKGROUND

RNA methylation refers to a form of methyl modification in RNA that modulates various epigenetic alterations. Mounting studies have focused on its potential mechanisms in cancer initiation and progression. However, the prognostic value and potential role of RNA methylation in the immune microenvironment of pancreatic cancer remain unclear.

METHODS

Comprehensive bioinformatics analysis was performed to illuminate the expression profiles of RNA methylation modulators. In addition, the ConsensusClusterPlus algorithm was utilized to identify two remarkably different subtypes, and a feasible risk stratification method was established to accurately estimate prognosis. In addition, we validated our signature at the cytology and histology levels and conducted functional experiments to explore the biological functions of our key genes.

RESULTS

Two subtypes with remarkable survival differences were identified by the consensus clustering algorithm. Cluster 2 tended to have higher expression levels of RNA methylation regulators and to be the high RNA methylation group. In addition, cluster 1 exhibited a significantly higher abundance of almost all immune cells and increased immune checkpoint expression compared to cluster 2. Chemotherapeutic sensitivity analysis indicated that there were significant differences in the sensitivity of four of the six drugs between different subgroups. Mutation investigation revealed a higher mutation burden and a higher number of mutations in cluster 2. An accurate and feasible risk stratification method was established based on the expression of key genes of each subtype. Patients with low risk scores exhibited longer survival times in one training (TCGA) and two validation cohorts (ICGC, GSE57495), with p values of 0.001, 0.0081, and 0.0042, respectively. In addition, our signature was further validated in a cohort from Fudan University Shanghai Cancer Center. The low-risk group exhibited higher immune cell abundance and immune checkpoint levels than the high-risk group. The characteristics of the low-risk group were consistent with those of cluster 1: higher stromal score, estimate score, and immune score and lower tumor purity. Additionally, cell function investigations suggested that knockdown of CDKN3 remarkably inhibited the proliferation and migration of pancreatic cancer cells.

CONCLUSIONS

RNA methylation has a close correlation with prognosis, immune infiltration and therapy in pancreatic cancer. Our subtypes and risk stratification method can accurately predict prognosis and the efficacy of immune therapy and chemotherapy.