EIF4A3-induced circFIP1L1 represses miR-1253 and promotes radiosensitivity of nasopharyngeal carcinoma

EIF4A3 Promotes Cell Proliferation via CDC5L Upregulation in Human Breast Cancer Cells

Breast cancer is one of the most common diseases affecting women's health. While research on breast cancer has made progress in recent years, it remains a major health concern. Studies have shown that the translation initiation factor EIF4A3 is closely related to the occurrence and development of tumors, but the specific mechanism is still unclear. In this study, we aimed to explore the specific molecular mechanism of EIF4A3 in promoting the malignant process of breast cancer in vivo and in vitro. Our results showed that the expression of EIF4A3 was significantly upregulated in breast cancer, and overexpression of EIF4A3 could accelerate the growth of breast cancer cells. RIP-seq and RIP-RT-qPCR analyses indicated that EIF4A3 can bind to the mRNA of CDC5L and influence its expression. From the catRAPID we predicted that EIF4A3-protein could bind to CDC5L by the 5705-5954 region of CDC5L-mRNA. CDC5L was the downstream effector of EIF4A3. These results suggested that the EIF4A3-CDC5L axis promotes the proliferation of breast cancer cells. This study provides a theoretical basis for understanding the role of EIF4A3 in the malignant process of breast cancer.

Circular RNAs in cancer

Circular RNA (circRNA), a subtype of noncoding RNA, has emerged as a significant focus in RNA research due to its distinctive covalently closed loop structure. CircRNAs play pivotal roles in diverse physiological and pathological processes, functioning through mechanisms such as miRNAs or proteins sponging, regulation of splicing and gene expression, and serving as translation templates, particularly in the context of various cancers. The hallmarks of cancer comprise functional capabilities acquired during carcinogenesis and tumor progression, providing a conceptual framework that elucidates the nature of the malignant transformation. Although numerous studies have elucidated the role of circRNAs in the hallmarks of cancers, their functions in the development of chemoradiotherapy resistance remain unexplored and the clinical applications of circRNA-based translational therapeutics are still in their infancy. This review provides a comprehensive overview of circRNAs, covering their biogenesis, unique characteristics, functions, and turnover mechanisms. We also summarize the involvement of circRNAs in cancer hallmarks and their clinical relevance as biomarkers and therapeutic targets, especially in thyroid cancer (TC). Considering the potential of circRNAs as biomarkers and the fascination of circRNA-based therapeutics, the "Ying-Yang" dynamic regulations of circRNAs in TC warrant vastly dedicated investigations.

A fishnet between nasopharyngeal carcinoma and resistance: the competing endogenous RNA network

OPINION STATEMENT

Chemotherapy and radiotherapy (chemo-/radiotherapy) have advanced as the main treatment modalities for nasopharyngeal carcinoma (NPC), improving patient survival rates. However, chemo-/radiotherapy resistance in NPC cells has emerged as a key factor contributing to poor prognosis. Recently, competing endogenous RNA networks (ceRNETs) have garnered attention for their potential clinical value in studying chemo-/radiotherapy resistance. In this review, we aimed to explore the molecular mechanisms of ceRNA-related molecules, including circular RNA (circRNA), long non-coding RNA (lncRNA), microRNA (miRNA), and other competing endogenous RNAs, in regulating the chemo-/radiotherapy resistance in NPC. Additionally, we discuss the potential applications of ceRNA as a prognostic indicator and therapeutic target for this resistance.

EIF4A3-induced hsa_circ_0127071 promotes human glomerular mesangial cells senescence via JAK2/STAT5 signaling pathway

Circular RNAs (circRNAs) have garnered attention for their potential involvement in the regulation of cellular aging processes. Exploring the role and mechanism of circRNAs in cellular senescence may help to identify new anti-aging therapeutic targets. In the present study, we investigated the role and regulatory mechanism of hsa_circ_0127071 in renal aging. We employed high-throughput sequencing to assess circRNA expression differences in kidney tissues from young and old groups. qRT-PCR confirmed that the expression of hsa_circ_0127071 in kidney tissue of the old group was significantly higher than that of the young group. Cellular senescence was evaluated using SA-β-Gal staining and Masson's trichrome staining. Using RNA Immunoprecipitation (RIP), RNA Pull-Down Assay (RNA pull down), and Western Blot (WB) to study the interaction between hsa_circ_0127071 and aging related pathway proteins. In this study, we found that the expression of hsa_circ_0127071 in kidney tissue of the old group was significantly higher than that of the young group. Silencing of EIF4A3, a protein involved in the JAK2/STAT5 signaling pathway, was found to delay the aging process. On the basis of silencing EIF4A3 expression, the JAK2/STAT5 signaling pathway was activated by Erythropoietin (EPO) processing, and the senescence of Human glomerular mesangial cells (HGMCs) increased. After treatment with Losartan (LOS), the activity of JAK2/STAT5 pathway was decreased and the aging process of HGMCs was delayed. Our findings demonstrate that hsa_circ_0127071 promotes renal aging through the EIF4A3/JAK2/STAT5 signaling axis, highlighting a novel potential therapeutic target for the management of renal aging and associated disorders.

The crosstalk between alternative splicing and circular RNA in cancer: pathogenic insights and therapeutic implications

RNA splicing is a fundamental step of gene expression. While constitutive splicing removes introns and joins exons unbiasedly, alternative splicing (AS) selectively determines the assembly of exons and introns to generate RNA variants corresponding to the same transcript. The biogenesis of circular RNAs (circRNAs) is inextricably associated with AS. Back-splicing, the biogenic process of circRNA, is a special form of AS. In cancer, both AS and circRNA deviate from the original track. In the present review, we delve into the intricate interplay between AS and circRNAs in the context of cancer. The relationship between AS and circRNAs is intricate, where AS modulates the biogenesis of circRNAs and circRNAs in return regulate AS events. Beyond that, epigenetic and posttranscriptional modifications concurrently regulate AS and circRNAs. On the basis of this modality, we summarize current knowledge on how splicing factors and other RNA binding proteins regulate circRNA biogenesis, and how circRNAs interact with splicing factors to influence AS events. Specifically, the feedback loop regulation between circRNAs and AS events contributes greatly to oncogenesis and cancer progression. In summary, resolving the crosstalk between AS and circRNA will not only provide better insight into cancer biology but also provoke novel strategies to combat cancer.

EIF4A3-Induced Upregulation of hsa_circ_0049396 Attenuates the Tumorigenesis of Nasopharyngeal Carcinoma by Regulating the Hippo-YAP Pathway

Circular RNAs (circRNAs) and eukaryotic translation initiation factor 4A3 (EIF4A3) have been reported to participate in the pathogenesis of nasopharyngeal carcinoma (NPC), but their mechanism has not been fully understood. This research aimed to confirm the role and regulatory mechanism of hsa_circ_0049396 interacting with EIF4A3 in NPC tumorigenesis. Quantitative real time polymerase chain reaction (qRT-PCR) was executed to detect the levels of hsa_circ_0049396 and EIF4A3. Cell function experiments and nude mice xenograft assay were used to confirm the role of hsa_circ_0049396 in NPC. The regulatory effect of EIA4A3 on hsa_circ_0049396 was determined by circInteractome prediction, RNA binding protein immunoprecipitation (RIP) assay, and qRT-PCR. In addition, the Hippo-YAP pathway-related proteins and EIF4A3 protein were detected by western blotting. hsa_circ_0049396 was proved to be downregulated in NPC samples, and its low expression indicated the poor prognosis of NPC. After upregulating hsa_circ_0049396 in NPC cells, the proliferation, migration, invasion, and tumor growth in vivo were suppressed by inhibiting the Hippo-YAP pathway. Moreover, EIF4A3 bound to the flanking regions of the hsa_circ_0049396 to enhance hsa_circ_0049396 expression in NPC cells. hsa_circ_0049396 mediated by EIF4A3 in NPC can attenuate NPC tumorigenesis by inhibiting the Hippo-YAP pathway. This finding may provide a potential early diagnostic biomarker or drug target to improve the precision medicine approaches of NPC.

Circular RNAs: Epigenetic regulators of PTEN expression and function in cancer

Epigenetic regulation of gene expression, without altering the DNA sequence, is involved in many normal cellular growth and division events, as well as diseases such as cancer. Epigenetics is no longer limited to DNA methylation, and histone modification, but regulatory non-coding RNAs (ncRNAs) also play an important role in epigenetics. Circular RNAs (circRNAs), single-stranded RNAs without 3' and 5' ends, have recently emerged as a class of ncRNAs that regulate gene expression. CircRNAs regulate phosphatase and tensin homolog (PTEN) expression at various levels of transcription, post-transcription, translation, and post-translation under their own regulation. Given the importance of PTEN as a tumor suppressor in cancer that inhibits one of the most important cancer pathways PI3K/AKT involved in tumor cell proliferation and survival, significant studies have been conducted on the regulatory role of circRNAs in relation to PTEN. These studies will be reviewed in this paper to better understand the function of this protein in cancer and explore new therapeutic approaches.

EIF4A3-Bound hsa_circ_0006847 Exerts a Tumor-Suppressive Role in Gastric Cancer

Numerous studies have shown that circular RNAs are associated with the occurrence and development of various cancers, but the biological functions and mechanisms of hsa_circ_0006847 (circASPHD1) in gastric cancer (GC) remain unclear. The expression of hsa_circ_0006847 in GC cell lines, tissue, and plasma from GC patients was assayed by quantitative real-time reverse transcription-polymerase chain reaction. Hsa_circ_0006847 expression in cells was downregulated or upregulated by transfected small interfering RNA (siRNA) or overexpression plasmid. The role of hsa_circ_0006847 in GC was investigated with Cell Counting Kit-8, EdU, Transwell, flow cytometry assays, and in a subcutaneous xenograft tumor model. In addition, the interaction of eukaryotic translation initiation factor 4A3 (EIF4A3) and hsa_circ_0006847 was determined with western blot, biotin-labeled RNA pull-down, and RNA immunoprecipitation assays. Co-immunoprecipitation and mass spectrometry were used to validate the combination of EIF4A3 and synaptopodin-2 (SYNPO2). The expression of hsa_circ_0006847 was decreased in GC tissues and cells and indicated poor survival and prognosis. Overexpression of hsa_circ_0006847 inhibited cell proliferation, migration, and invasion. Flow cytometry showed that upregulation of hsa_circ_0006847 resulted in promotion of apoptosis of GC cells and inhibited their progression through the G0/G1 phase. Downregulation of hsa_circ_0006847 expression had the opposite effects. Overexpression of hsa_circ_0006847 in subcutaneous tumor xenografts inhibited tumor growth. Mechanically, hsa_circ_0006847 promoted the binding of EIF4A3 to SYNPO2 by recruiting EIF4A3, which inhibited the growth of GC. The tumor suppressor activity of hsa_circ_0006847, inhibition of the occurrence and development of GC, was mediated by promotion of EIF4A3 and the binding of EIF4A3 to SYNPO2. The results support the study of hsa_circ_0006847 as a novel therapeutic target for the treatment of GC.

Deciphering the impact of circRNA-mediated autophagy on tumor therapeutic resistance: a novel perspective

Cancer therapeutic resistance remains a significant challenge in the pursuit of effective treatment strategies. Circular RNAs (circRNAs), a class of non-coding RNAs, have recently emerged as key regulators of various biological processes, including cancer progression and drug resistance. This review highlights the emerging role of circRNAs-mediated autophagy in cancer therapeutic resistance, a cellular process that plays a dual role in cancer by promoting both cell survival and death. Increasing evidence suggests that circRNAs can modulate autophagy pathways, thereby influencing the response of cancer cells to therapeutic agents. In this context, the intricate interplay between circRNAs, autophagy, and therapeutic resistance is explored. Various mechanisms are discussed through which circRNAs can impact autophagy, including direct interactions with autophagy-related genes, modulation of signaling pathways, and cross-talk with other non-coding RNAs. Furthermore, the review delves into specific examples of how circRNA-mediated autophagy regulation can contribute to resistance against chemotherapy and radiotherapy. Understanding these intricate molecular interactions provides valuable insights into potential strategies for overcoming therapeutic resistance in cancer. Exploiting circRNAs as therapeutic targets or utilizing them as diagnostic and predictive biomarkers opens new avenues for developing personalized treatment approaches. In summary, this review underscores the importance of circRNA-mediated autophagy in cancer therapeutic resistance and proposes future directions for research in this exciting and rapidly evolving field.

Emerging roles of circular RNAs in nasopharyngeal carcinoma: functions and implications

Nasopharyngeal carcinoma (NPC) is a distinct malignancy primarily prevalent in Southern China and Southeast Asia. Circular RNAs (circRNAs), a class of non-coding RNAs, are evolutionarily conserved and exhibit remarkable stability. Their dysregulation has been observed in various cancers, including NPC. In this review, we investigate the pivotal role of circRNAs in NPC, focusing specifically on their involvement in tumor proliferation, apoptosis, metastasis, angiogenesis, stemness, metabolism, and the tumor microenvironment. We highlight the diagnostic and prognostic potential of circRNAs in NPC, emphasizing their utility as biomarkers for early detection, disease monitoring, and prediction of treatment outcomes. Additionally, we explore the therapeutic implications of circRNAs in NPC, highlighting their potential for targeted therapies.

The promising role of miRNAs in radioresistance and chemoresistance of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a malignant epithelial tumor that develops in the nasopharynx. It has a distinct ethnic and geographical distribution, and emerging evidence suggests that it is an ecological disease. Most patients respond well to radiation combined with chemotherapy as the primary treatment for NPC. However, some patients will eventually develop radio resistance and chemoresistance, resulting in recurrence and metastasis, which is a primary cause of poor prognosis. The processes underlying radio resistance and chemoresistance in NPC are complex and unknown. MicroRNAs (miRNAs) are endogenic non-coding RNA molecules. They play a role in a variety of cell functions as well as development of disease such as cancer. There has been considerable data demonstrating the existence of numerous aberrant miRNAs in cancer tissues, cells, and biofluids, which indicates the importance of studying the influence of miRNAs on NPC. Therefore, this review comprehensively analyzes the elaborate mechanisms of miRNAs affecting the radio resistance and chemoresistance of NPC. Multiple tumor-specific miRNAs can be employed as therapeutic and prognostic biological indicators.

miR-128-3p increases the radiosensitivity in nasopharyngeal carcinoma via regulating vascular endothelial growth factor C

PURPOSE

This study aims to investigate the role of miR-128-3p in the radiosensitivity of nasopharyngeal carcinoma (NPC) and its underlying mechanism.

METHODS

6-10B cells were transfected with miR-128-3p mimic, pcDNA-VEGFC, and the corresponding negative control. C666-1 cells were transfected with miR-128-3p inhibitor, sh-VEGFC, and the corresponding negative control. RT-qPCR was used to determine the miR-128-3p and VEGFC mRNA expression level. Dual-luciferase assay was used to investigate the relationship between miR-128-3p and VEGFC. The protein levels of VEGFC, H2AX, γ-H2AX, p-P50, p-P65, p-IκB, and the apoptosis markers Bcl-2, caspase3, caspase9, and Bax were detected by Western blot. The proliferation activity was detected by CCK-8, and cell DNA damage was assessed by comet assay. The apoptosis rate was detected by flow cytometry. The growth of NPC in vivo was observed in mice through xenotransplantation. TUNEL staining was used to detect cell apoptosis in tumor tissues.

RESULTS

miR-128-3p was targeted and was negatively regulated with VEGFC. Overexpression of miR-128-3p or knockdown VEGFC significantly inhibited the proliferation of 6-10B and C666-1 cells, induced DNA damage and apoptosis and promoted the radiosensitivity of cells. Knocking down miR-128-3p or up-regulated VEGFC promoted the proliferation of C666-1 and 6-10B cells, reduced cell DNA damage and apoptosis, and enhanced cell resistance to radiotherapy. Overexpression of miR-128-3p reversed the effect of VEGFC on 6-10B cells and inhibited P50/P65/IKB signal pathway. In vivo, experiments in mice confirmed that miR-128-3p significantly inhibited NPC proliferation and promoted DNA damage and apoptosis by targeting VEGFC.

CONCLUSION

The miR-128-3p pathway is a novel therapy target to overcome radiation resistance in NPC.

Recent advances of exosomal circRNAs in cancer and their potential clinical applications

Circular RNA (circRNA) is a type of non-coding RNA that forms a covalently closed, uninterrupted loop. The expression of circRNA differs among cell types and tissues, and various circRNAs are aberrantly expressed in a variety of diseases, including cancer. Aberrantly expressed circRNAs contribute to disease progression by acting as microRNA sponges, functional protein sponges, or novel templates for protein translation. Recent studies have shown that circRNAs are enriched in exosomes. Exosomes are spherical bilayer vesicles released by cells into extracellular spaces that mediate intercellular communication by delivering cargoes. These cargoes include metabolites, proteins, lipids, and RNA molecules. Exosome-mediated cell-cell or cell-microenvironment communications influence the progression of carcinogenesis by regulating cell proliferation, angiogenesis, metastasis as well as immune escape. In this review, we summarize the current knowledge about exosomal circRNAs in cancers and discuss their specific functions in tumorigenesis. Additionally, we discuss the potential value of exosomal circRNAs as diagnostic biomarkers and the potential applications of exosomal circRNA-based cancer therapy.

Molecular interplay between EIF4 family and circular RNAs in cancer: Mechanisms and therapeutics

The eukaryotic translation initiation factor 4 (EIF4) family is a major contributor to the recruitment of mRNAs to ribosomes during the initial translation stage in eukaryotes, whose dysregulation either allows for cancer transformation or prevents disordered cancerous cell growth. Circular RNAs (circRNAs), which exhibit distinctive structures and are widely expressed in eukaryotes, are anticipated to be a clinical diagnostic biomarker for cancer therapy. There is considerable evidence that EIF4s can influence the biogenesis, transport, and function of circRNAs and, in turn, circRNAs can control the expressions of EIF4s through certain molecular pathways. Herein, we primarily review the emerging studies of the EIF4 family and pinpoint the roles of dysregulated EIF4s in cancer. We also evaluate the patterns of intricate interactions between circRNAs and EIF4s and discuss the potential utility of circRNA-based therapeutics targeting EIF4s in clinical cancer research.