RBM24 exacerbates bladder cancer progression by forming a Runx1t1/TCF4/miR-625-5p feedback loop

YAP1-induced RBM24 promotes the tumorigenesis of triple-negative breast cancer through the β-catenin pathway

Triple-negative breast cancer (TNBC) is the most aggressive breast cancer subtype and refractory to current treatments. RBM24 is an RNA-binding protein and shows the ability to regulate tumor progression in multiple cancer types. However, its role in TNBC is still unclear. In this study, we analyzed publicly available profiling data from TNBC tissues and cells. Loss- and gain-of-function experiments were performed to determine the function of RBM24 in TNBC cells. The mechanism for RBM24 action in TNBC was investigated. RBM24 was deregulated in TNBC tissues and TNBC cells with depletion of SIPA1, YAP1, or ARID1A, three key regulators of TNBC. Compared to MCF10A breast epithelial cells, TNBC cells had higher levels of RBM24. Knockdown of RBM24 inhibited TNBC cell proliferation, colony formation, and tumorigenesis, while overexpression of RBM24 promoted aggressive phenotype in TNBC cells. YAP1 overexpression induced the expression of RBM24 and the RBM24 promoter-driven luciferase reporter. YAP1 was enriched at the promoter region of RBM24. Overexpression of RBM24 increased β-catenin-dependent transcriptional activity. Most importantly, knockdown of CTNNB1 rescued RBM24 aggressive phenotype in TNBC cells. Collectively, the YAP1/RBM24/β-catenin axis plays a critical role in driving TNBC progression. RBM24 may represent a novel therapeutic target for TNBC treatment.

CircSEPT9 promotes breast cancer progression by regulating PTBP3 expression via sponging miR-625-5p

BACKGROUND

Breast cancer (BC) is a common malignancy which threatens the health of women. Circular RNAs (circRNAs) are critical factors in multiple cancers, including BC. The aim of this experiment was to investigate the molecular mechanisms of circRNA Septin 9 (circSEPT9) in the progression of BC.

METHODS

CircSEPT9, microRNA-625-5p (miR-625-5p) and polypyrimidine tract-binding protein 3 (PTBP3) levels were determined by quantitative real-time polymerase chain reaction (qRT-PCR). Western blot was performed to detect the protein levels of PTBP3, E-cadherin and vimentin. Cell counting kit-8 assay (CCK8) and thymidine analog 5-ethynyl-2'-deoxyuridine (EDU) was utilized for proliferation examination. Flow cytometry was conducted to measure apoptosis. Transwell assay and wound healing assay to investigate the migration of BC cells. Glucose uptake and lactate production were determined by specific kits. Additionally, dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were utilized to verify the interaction. A murine xenograft model was established to investigate the function of circSEPT9 in BC in vivo.

RESULTS

Overexpression of circSEPT9 was found in BC tissues and cells. Silencing circSEPT9 impeded BC cell proliferation, migration, epithelial-mesenchymal transition (EMT) and glycolytic metabolism but facilitated cell apoptosis in vitro. Meanwhile, circSEPT9 knockdown constrained tumor growth in vivo. MiR-625-5p was targeted by circSEPT9. The influence of silencing circSEPT9 on BC cell function was regained by miR-625-5p inhibitor. Furthermore, miR-625-5p regulated BC cell malignant phenotypes via downregulating PTBP3.

CONCLUSION

circSEPT9 contributed to the malignant progression of BC by up-regulating PTBP3 via sponging miR-625-5p.

RUNX1T1 modulates myogenic differentiation by regulating the calcium signaling pathway and the alternative splicing of ROCK2

RUNX1T1 (Runt-related transcription factor 1, translocated to 1) plays a wide-ranging and diverse role in cellular development, including hematopoiesis and adipogenesis. However, little is known about the function of RUNX1T1 in the skeletal muscle development. Here, we assessed the impact of RUNX1T1 on the proliferation and myogenic differentiation of goat primary myoblasts (GPMs). It was observed that RUNX1T1 is highly expressed during the early stages of myogenic differentiation and the fetal stage. Moreover, the knockdown of RUNX1T1 promotes the proliferation and inhibits myogenic differentiation and mitochondrial biogenesis of GPMs. RNA sequencing analysis revealed that significantly differentially expressed genes in RUNX1T1 knockdown cells were enriched in the calcium signaling pathway. Additionally, we discovered that RUNX1T1 regulates alternative splicing (AS) events involved in myogenesis. We also show that silencing RUNX1T1 blocked the Ca²⁺ -CAMK signaling pathway and reduced the expression levels of muscle-specific isoforms of recombinant rho associated coiled coil containing crotein kinase 2 (ROCK2) during myogenic differentiation, partially explaining why RUNX1T1 deficiency leads to the impairment of myotube formation. These findings suggest that RUNX1T1 is a novel regulator of myogenic differentiation that regulates the calcium signaling pathway and AS of ROCK2. Overall, our results highlight the critical role of RUNX1T1 in myogenesis and broaden our understanding of myogenic differentiation.

Alternative splicing in bladder cancer: potential strategies for cancer diagnosis, prognosis, and treatment

Bladder cancer is the most common malignancy of the urinary tract worldwide. The therapeutic options to tackle this disease comprise surgery, intravesical or systemic chemotherapy, and immunotherapy. Unfortunately, a wide number of patients ultimately become resistant to these treatments and develop aggressive metastatic disease, presenting a poor prognosis. Therefore, the identification of novel therapeutic approaches to tackle this devastating pathology is urgently needed. However, a significant limitation is that the progression and drug response of bladder cancer is strongly associated with its intrinsic molecular heterogeneity. In this sense, RNA splicing is recently gaining importance as a critical hallmark of cancer since can have a significant clinical value. In fact, a profound dysregulation of the splicing process has been reported in bladder cancer, especially in the expression of certain key splicing variants and circular RNAs with a potential clinical value as diagnostic/prognostic biomarkers or therapeutic targets in this pathology. Indeed, some authors have already evidenced a profound antitumor effect by targeting some splicing factors (e.g., PTBP1), mRNA splicing variants (e.g., PKM2, HYAL4-v1), and circular RNAs (e.g., circITCH, circMYLK), which illustrates new possibilities to significantly improve the management of this pathology. This review represents the first detailed overview of the splicing process and its alterations in bladder cancer, and highlights opportunities for the development of novel diagnostic/prognostic biomarkers and their clinical potential for the treatment of this devastating cancer type. This article is categorized under: RNA Processing > Splicing Regulation/Alternative Splicing RNA in Disease and Development > RNA in Disease.

Identification of endothelial-related molecular subtypes for bladder cancer patients

Background

Bladder cancer (BC) is a disease with significant heterogeneity and poor prognosis. The prognosis and therapeutic response of BC patients are significantly influenced by endothelial cells in the tumor microenvironment. In order to understand BC from the perspective of endothelial cells, we orchestrated molecular subtypes and identified key genes.

Methods

Single-cell and bulk RNA sequencing data were extracted from online databases. R and its relative packages were used to analyze these data. Cluster analysis, prognostic value analysis, function analysis, immune checkpoints, tumor immune environment and immune prediction were conducted.

Results

Five endothelial-related genes (CYTL1, FAM43A, HSPG2, RBP7, and TCF4) divided BC patients in the TCGA, GSE13507, and GSE32894 datasets into two clusters, respectively. In prognostic value analysis, patients in the cluster 2 were substantially associated with worse overall survival than those in the cluster 1 according to the results of TCGA, GSE13507 and GSE32894 datasets. In the results of functional analysis, the endothelial-related clusters was enriched in immune-related, endothelial-related and metabolism-related pathways. Samples in the cluster 1 had a statistically significant increase in CD4+ T cells and NK-cell infiltration. Cluster 1 was positively correlated with the cancer stem score and tumor mutational burden score. The results of immune prediction analysis indicated that 50.6% (119/235) of patients in the cluster 1 responded to immunotherapy, while the response rate in the cluster 2 decreased to 16.7% (26/155).

Conclusion

In this study, we categorized and discovered distinctive prognosis-related molecular subtypes and key genes from the perspective of endothelial cells at the genetic level by integrating single-cell and bulk RNA sequencing data, primarily to provide a roadmap for precision medicine.

DDX58 expression promotes inflammation and growth arrest in Sertoli cells by stabilizing p65 mRNA in patients with Sertoli cell-only syndrome

Sertoli cell -only syndrome (SCOS) is a type of testicular pathological failure that causes male infertility and no effective treatment strategy, is available for this condition. Moreover, the molecular mechanism underlying its development remains unknown. We identified DExD/H-Box helicase 58 (DDX58) as a key gene in SCOS based on four datasets of testicular tissue samples obtained from the Gene Expression Synthesis database. DDX58 was significantly upregulated in SCOS testicular Sertoli cells. Moreover, high expression of DDX58 was positively correlated with the expression of several testicular inflammatory factors, such as IL -1β, IL-18, and IL-6. Interestingly, DDX58 could be induced in the D-galactose (D-gal)-stimulated TM4 cell injury model. Whereas silencing of DDX58 inhibited D-gal -mediated p65 expression, inflammatory cytokine release, and growth arrest. Mechanistically, we found that DDX58 acts as an RNA-binding protein, which enhances p65 expression by promoting mRNA stability. Furthermore, p65 gene silencing decreased the expression of inflammatory cytokines and inhibition of cell growth in D-gal-induced cells. In conclusion, our findings demonstrate that DDX58 promotes inflammatory responses and growth arrest in SCOS Sertoli cells by stabilizing p65 mRNA. Accordingly, the DDX58/p65 regulatory axis might be a therapeutic target for SCOS.

Mechanism of METTL14-mediated m6A modification in non-small cell lung cancer cell resistance to cisplatin

Methyltransferase-like 14 (METTL14) mediates N⁶-methyladenosine (m⁶A) modification to influence cancer progression. This study aims to determine the mechanism of METTL14-mediated m⁶A in non-small cell lung cancer (NSCLC) cell resistance to cisplatin (DDP). METTL14, miR-19a-5p, RBM24, and AXIN1 expressions in NSCLC tissues/cells were determined. DDP-resistant cell line was obtained, followed by the interference of METTL14 expression. NSCLC cells were treated with DDP to establish a drug-resistant cell line, and METTL14 expression in cells was intervened. The IC50 of NSCLC cells to DDP was measured by CCK-8 assay. NSCLC cell proliferation and apoptosis were observed by clone formation assay and flow cytometry. The content of m⁶A in total RNA in tissues and cells of NSCLC patients was detected using m⁶A Methylation Quantification Kit. The expressions of DGCR8-bound pri-miR-19a and m⁶A-modified pri-miR-19a were detected. The binding relationships between miR-19a-5p and RBM24 and RBM24 and AXIN1 were validated using dual-luciferase assay and RNA immunoprecipitation. Finally, mouse xenograft tumor model was established to verify the role of METTL14 in vivo. METTL14 was highly expressed in NSCLC. METTL14 silencing diminished IC50 to DDP, repressed NSCLC cell proliferation, and enhanced apoptosis. METTL14-mediated m⁶A induced recognition and processing of pri-miR-19a by DGCR8, thus promoting the transition of pri-miR-19a to miR-19a-5p, repressing RBM24 expression, reducing the binding of RBM24 and AXIN1, and suppressing AXIN1 transcription. miR-19a-5p overexpression or RBM24/AXIN1 silencing abolished the effect of METTL14 silencing on NSCLC cell resistance to DDP. METTL14 silencing in vivo enhanced the suppressive role of DDP to tumor growth. Collectively, METTL14-mediated m⁶A modification facilitated NSCLC cell resistance to DDP via miR-19a-5p/RBM24/AXIN1 axis. KEY MESSAGES: • METTL14 is highly expressed NSCLC and further increased in DDP-resistant cells. • METTL14 silencing attenuates DDP resistance of NSCLC cells. • METTL14 promotes the nature of pri-miR-19a by upregulating pri-miR-19a m6A level. • miR-19a-5p targets RBM24, thus reducing the binding of RBM24 and AXIN1 and inhibiting AXIN1 transcription. • METTL14 silencing in vivo enhances the suppressive role of DDP to tumor growth.

LINC00958 Inhibits Autophagy of Bladder Cancer Cells via Sponge Adsorption of miR-625-5p to Promote Tumor Angiogenesis and Oxidative Stress

Objective

This study further explored LINC00958's role in promoting tumor angiogenesis (AG) and oxidative stress (OS) development by inhibiting BC cell autophagy through sponge adsorption of miR-625-5p.

Methods

BC patients and healthy controls who visited our hospital between June 2017 and February 2019 were selected as the research group (RG) and the control group (CG), respectively, with a total of 133 study subjects. Peripheral blood LINC00958 and miR-625-5p in both cohorts of participants were detected. Additionally, human bladder transitional cell carcinoma cells (T24 and J82) and human normal urothelial cells (SV-HUC-1) were purchased. Alterations in cell biological behavior were observed after transfecting miR-625-5p-mimics, miR-625-5p-inhibition, and miR-625-5p-NC sequences into these cells, respectively. Besides, ELISA was performed to quantify inflammatory factors (IFs), AG indicators, and OS indexes in cells. Subsequently, a double luciferase reporter (DLR) assay was performed to verify the targeting relationship between LINC00958 and miR-625-5p. Finally, BALB/c-nu nude mice were purchased, and T24 cells transfected with silenced LINC00958 and miR-625-5p expression sequences were used to establish subcutaneous tumors to observe tumor growth and pathological changes.

Results

RG exhibited higher LINC00958 and lower miR-625-5p than CG. LINC00958 and miR-625-5p were strongly linked to myometrial invasion (MI), lymph node metastasis (LNM), distant metastasis (DM), and histology in BC patients, and the increase of LINC00958 and the decrease of miR-625-5p predicted an increased risk of prognostic death in such patients. After miR-625-5p inhibition, the capacity of BC cells to proliferate, invade, and migrate enhanced and the AG, inflammatory response, and OS injury increased, while the apoptosis rate and autophagy ability decreased. The DLR assay revealed inhibited LINC00958WT fluorescence activity by miR-625-5p-mimics, while the biological behavior of BC cells cotransfected with sh-LINC00958 and miR-625-5p-inhibition had no difference with the functions of sh-control and miR-625-5p-NC cotransfected cells. Finally, the nude mouse tumorigenesis experiment showed that the tumor mass, volume, and histopathological features of the sh-LINC00958 group were decreased compared with the sh-control group, while those of the miR-625-5p-inhibition group were increased versus miR-625-5p-NC.

Conclusions

In BC, LINC00958 is highly expressed while miR-625-5p is underexpressed. LINC00958 can inhibit cell autophagy to enhance cell activity; promote OS, inflammation, and AG; and regulate tumor immunity by targeting miR-625-5p, thus participating in the development of BC.

RUNX1T1 function in cell fate

RUNX1T1 (Runt-related transcription factor 1, translocated to 1), a myeloid translocation gene (MTG) family member, is usually investigated as part of the fusion protein RUNX1-RUNX1T1 for its role in acute myeloid leukemia. In the main, by recruiting histone deacetylases, RUNX1T1 negatively influences transcription, enabling it to regulate the proliferation and differentiation of hematopoietic progenitors. Moreover, the formation of blood vessels, neuronal differentiation, microglial activation following injury, and intestinal development all relate closely to the expression of RUNX1T1. Furthermore, through alternative splicing of RUNX1T1, short and long isoforms have been noted to mediate adipogenesis by balancing the differentiation and proliferation of adipocytes. In addition, RUNX1T1 plays wide-ranging and diverse roles in carcinoma as a biomarker, suppressor, or positive regulator of carcinogenesis, closely correlated to specific organs and dominant signaling pathways. The aim of this work was to investigate the structure of RUNX1T1, which contains four conserved nervy homolog domains, and to demonstrate crosstalk with the Notch signaling pathway. Moreover, we endeavored to illustrate the effects of RUNX1T1 on cell fate from multiple aspects, including its influence on hematopoiesis, neuronal differentiation, microglial activation, intestinal development, adipogenesis, angiogenesis, and carcinogenesis.

The CDK1/TFCP2L1/ID2 cascade offers a novel combination therapy strategy in a preclinical model of bladder cancer

Aberrant activation of embryogenesis-related molecular programs in urothelial bladder cancer (BC) is associated with stemness features related to oncogenic dedifferentiation and tumor metastasis. Recently, we reported that overexpression of transcription factor CP2-like protein-1 (TFCP2L1) and its phosphorylation at Thr177 by cyclin-dependent kinase-1 (CDK1) play key roles in regulating bladder carcinogenesis. However, the clinical relevance and therapeutic potential of this novel CDK1-TFCP2L1 molecular network remain elusive. Here, we demonstrated that inhibitor of DNA binding-2 (ID2) functions as a crucial mediator by acting as a direct repressive target of TFCP2L1 to modulate the stemness features and survival of BC cells. Low ID2 and high CDK1 expression were significantly associated with unfavorable clinical characteristics. TFCP2L1 downregulated ID2 by directly binding to its promoter region. Consistent with these findings, ectopic expression of ID2 or treatment with apigenin, a chemical activator of ID2, triggered apoptosis and impaired the proliferation, suppressed the stemness features, and reduced the invasive capacity of BC cells. Combination treatment with the specific CDK1 inhibitor RO-3306 and apigenin significantly suppressed tumor growth in an orthotopic BC xenograft animal model. This study demonstrates the biological role and clinical utility of ID2 as a direct target of the CDK1-TFCP2L1 pathway for modulating the stemness features of BC cells.

Combination therapy with apigenin, a powerful antioxidant found in plants such as parsley and camomile, and a drug that inhibits the cell cycle protein CDK1 shows promise for developing therapies for bladder cancer (BC). Switching on genes usually activated in stem cells can cause cancer, including BC. Although CDK1 was known to activate one of these genes in BC cells, no way to suppress the activation had been identified. Jinbeom Heo at University of Ulsan College of Medicine, South Korea, and coworkers investigated CDK1’s role in BC. They found that the transcription factor activated by CDK1 suppressed a protein, ID2, that suppressed stem cell-like characteristics. Simultaneously suppressing CDK1 and boosting ID2 with apigenin strongly repressed tumor growth in a mouse model. These results help point the way to developing new treatment options for BC patients.

RBM24 in the Post-Transcriptional Regulation of Cancer Progression: Anti-Tumor or Pro-Tumor Activity?

Simple Summary

RBM24 is a highly conserved RNA-binding protein that plays critical roles in the post-transcriptional regulation of gene expression for initiating cell differentiation during embryonic development and for maintaining tissue homeostasis in adult life. Evidence is now accumulating that it is frequently dysregulated across human cancers. Importantly, RBM24 may act as a tumor suppressor or as an oncogene in a context- or background-dependent manner. Its activity can be regulated by protein–protein interactions and post-translational modifications, making it a potential therapeutic target for cancer treatment. However, molecular mechanisms underlying its function in tumor growth and metastasis remain elusive. Further investigation will be necessary to better understand how its post-transcriptional regulatory activity is controlled and how it is implicated in tumor progression. This review provides a comprehensive analysis of recent findings on the implication of RBM24 in cancer and proposes future research directions to delve more deeply into the mechanisms underlying its tumor-suppressive function or oncogenic activity.

Abstract

RNA-binding proteins are critical post-transcriptional regulators of gene expression. They are implicated in a wide range of physiological and pathological processes by modulating nearly every aspect of RNA metabolisms. Alterations in their expression and function disrupt tissue homeostasis and lead to the occurrence of various cancers. RBM24 is a highly conserved protein that binds to a large spectrum of target mRNAs and regulates many post-transcriptional events ranging from pre-mRNA splicing to mRNA stability, polyadenylation and translation. Studies using different animal models indicate that it plays an essential role in promoting cellular differentiation during organogenesis and tissue regeneration. Evidence is also accumulating that its dysregulation frequently occurs across human cancers. In several tissues, RBM24 clearly functions as a tumor suppressor, which is consistent with its inhibitory potential on cell proliferation. However, upregulation of RBM24 in other cancers appears to promote tumor growth. There is a possibility that RBM24 displays both anti-tumor and pro-tumor activities, which may be regulated in part through differential interactions with its protein partners and by its post-translational modifications. This makes it a potential biomarker for diagnosis and prognosis, as well as a therapeutic target for cancer treatment. The challenge remains to determine the post-transcriptional mechanisms by which RBM24 modulates gene expression and tumor progression in a context- or background-dependent manner. This review discusses recent findings on the potential function of RBM24 in tumorigenesis and provides future directions for better understanding its regulatory role in cancer cells.

E2F6/KDM5C promotes SF3A3 expression and bladder cancer progression through a specific hypomethylated DNA promoter

Background

Abnormal expression of splicing factor 3A subunit 3 (SF3A3), a component of the spliceosome, has been confirmed to be related to the occurrence and development of various cancers. However, the expression and function of SF3A3 in bladder cancer (BC) remains unclear.

Methods

The SF3A3 mRNA and protein level were measured in clinical samples and cell lines by quantitative real-time PCR, Western blot and immunofluorescence staining. Evaluate the clinical correlation between SF3A3 expression and clinicopathological characteristics through statistical analysis in BC patients. The function of SF3A3 in BC cells was determined in vitro using MTT and colony analysis. Co-immunoprecipitation (CoIP) assay was used to detected E2F6 and KDM5C interaction. Luciferase reporter and chromatin immunoprecipitation (ChIP) were used to examine the relationship between E2F6/KDM5C and SF3A3 expression.

Results

In the present study, we demonstrated that expression of SF3A3 was elevated in BC tissue compared to the normal bladder tissue. Importantly, the upregulation of SF3A3 in patients was correlated with poor prognosis. Additionally, overexpression of SF3A3 promoted while depletion of SF3A3 reduced the growth of BC cells in vivo and in vitro. Data from the TCGA database and clinical samples revealed that hypomethylation of the DNA promoter leads to high expression of SF3A3 in BC tissue. We found that upregulation of lysine-specific demethylase 5C (KDM5C) promotes SF3A3 expression via hypomethylation of the DNA promoter. The transcription factor E2F6 interacts with KDM5C, recruits KDM5C to the SF3A3 promoter, and demethylates the GpC island of H3K4me2, leading to high SF3A3 expression and BC progression.

Conclusions

The results demonstrated that depletion of the KDM5C/SF3A3 prevents the growth of BC in vivo and in vitro. The E2F6/KDM5C/SF3A3 pathway may be a potential therapeutic target for BC treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-022-02475-4.

Crucial Roles of miR-625 in Human Cancer

Genetic and epigenetic characteristics are core factors of cancer. MicroRNAs (miRNAs) are small non-coding RNAs which regulate gene expression at the post-transcriptional level via binding to corresponding mRNAs. Recently, increasing evidence has proven that miRNAs regulate the occurrence and development of human cancer. Here, we mainly review the abnormal expression of miR-625 in a variety of cancers. In summarizing the role and potential molecular mechanisms of miR-625 in various tumors in detail, we reveal that miR-625 is involved in a variety of biological processes, such as cell proliferation, invasion, migration, apoptosis, cell cycle regulation, and drug resistance. In addition, we discuss the lncRNA-miRNA-mRNA and circRNA-miRNA-mRNA networks and briefly explain the specific mechanisms of competing endogenous RNAs. In conclusion, we reveal the potential value of miR-625 in cancer diagnosis, treatment, and prognosis and hope to provide new ideas for the clinical application of miR-625.

RBM22, a Key Player of Pre-mRNA Splicing and Gene Expression Regulation, Is Altered in Cancer

RNA-Binding Proteins (RBP) are very diverse and cover a large number of functions in the cells. This review focuses on RBM22, a gene encoding an RBP and belonging to the RNA-Binding Motif (RBM) family of genes. RBM22 presents a Zinc Finger like and a Zinc Finger domain, an RNA-Recognition Motif (RRM), and a Proline-Rich domain with a general structure suggesting a fusion of two yeast genes during evolution: Cwc2 and Ecm2. RBM22 is mainly involved in pre-mRNA splicing, playing the essential role of maintaining the conformation of the catalytic core of the spliceosome and acting as a bridge between the catalytic core and other essential protein components of the spliceosome. RBM22 is also involved in gene regulation, and is able to bind DNA, acting as a bona fide transcription factor on a large number of target genes. Undoubtedly due to its wide scope in the regulation of gene expression, RBM22 has been associated with several pathologies and, notably, with the aggressiveness of cancer cells and with the phenotype of a myelodysplastic syndrome. Mutations, enforced expression level, and haploinsufficiency of RBM22 gene are observed in those diseases. RBM22 could represent a potential therapeutic target in specific diseases, and, notably, in cancer.

TPRG1-AS1 induces RBM24 expression and inhibits liver cancer progression by sponging miR-4691-5p and miR-3659

BACKGROUND & AIMS

Noncoding RNAs (ncRNAs) play critical roles in hepatocellular carcinoma (HCC) progression. Here, by performing RNA-sequencing (RNA-Seq) profiling, we sought to identify novel ncRNAs that potentially drive the heterogeneous progression of liver cancers.

METHODS

RNA-Seq profiles were obtained from 68 HCC specimens and 10 samples of adjacent non-tumour liver tissues. The functional significance of the potential driver ncRNAs was evaluated by cell experiments.

RESULTS

TPRG1-AS1 was identified as a potential driver noncoding RNA that promotes heterogeneous liver cancer progression. TPRG1-AS1 induced tumour suppressor RNA-binding motif protein 24 (RBM24), suppressing tumour growth by activating apoptotic tumour cell death. In addition, we report that TPRG1-AS1 acts as a competing endogenous RNA (ceRNA) for RBM24, sponging miR-4691-5p and miR-3659 to interfere with their binding to RBM24.

CONCLUSIONS

We suggest that TPRG1-AS1 is a novel ceRNA sponging miR-4691-5p and miR-3659, resulting in RBM24 expression and suppression of liver cancer growth. Our results provide new insights into the functions of ncRNAs in heterogeneous HCC progression.