Hsa_circ_0003258 promotes prostate cancer metastasis by complexing with IGF2BP3 and sponging miR-653-5p

Circular RNA LMBR1 inhibits bladder cancer progression by enhancing expression of the protein ALDH1A3

Background

Circular RNAs (circRNAs) have been identified as playing an integral role in the development of bladder cancer (BC). However, the mechanism by which circRNAs operate in the chemical carcinogenesis of BC remains unclear.

Methods

To explore this mechanism, we used RNA high-throughput sequencing to identify differentially expressed circRNA in bladder epithelial cells and chemically induced malignant transformed BC cells. Subsequently, in vitro experiments were conducted to investigate the biological function and molecular mechanism of circLMBR1 in BC. Finally, animal experiments were conducted to examine the clinical relevance of circLMBR1 in vivo.

Results

Our profiling of circular RNA expression during cellular malignant transformation induced by chemical carcinogens identified a subset of circRNAs associated with cell transformation. We verified that the expression of circLMBR1 in bladder epithelial malignant transformed cells was decreased compared with control cells, as well as in BC tissues and bladder cell lines. Furthermore, circLMBR1 was seen to inhibit the proliferation, invasion, and migration of BC cells both in vitro and in vivo. Mechanistically, circLMBR1 was found to exert its antitumor effect by binding to the protein ALDH1A3.

Conclusions

Our findings have revealed that circLMBR1 inhibits the progression of BC cells by binding to ALDH1A3 and upregulating its expression. As such, circLMBR1 serves as a promising predictor of BC and may provide a novel therapeutic target for the treatment of BC.

circCUL3 drives malignant progression of cervical cancer by activating autophagy through sponge miR-223-3p upregulation of ATG7

Circular RNA (circRNA) has emerged as a pivotal regulatory factor in cancer biology, yet its exact role in cervical cancer remains incompletely understood. In this study, we investigated the functional role of circCUL3 in cervical cancer and explored its potential as a therapeutic target. Functional gain and loss experiments were conducted in Hela and Siha cell lines to elucidate the biological functions of circCUL3 in cervical cancer. The results revealed that circCUL3 overexpression significantly enhanced cell viability, migration, and invasion while suppressing apoptosis, while circCUL3 knockout displayed the opposite effects. Mechanistically, we identified hsa-miR-223-3p as a target of circCUL3, with its expression being negatively regulated by circCUL3. Furthermore, we discovered that circCUL3 could sequester miR-223-3p, leading to the upregulation of ATG7 expression, and this was linked to the regulation of autophagy in cervical cancer cells. In vivo validation using a xenograft mouse model further supported our in vitro findings. Notably, we found that chloroquine (CQ), an autophagy inhibitor, restored miR-223-3p expression and counteracted the oncogenic effect of circCUL3 overexpression. In conclusion, circCUL3 potentially contributes to the malignant progression of cervical cancer by acting as a sponge for miR-223-3p, resulting in the upregulation of ATG7 and the activation of autophagy.

The role of circular RNA targeting IGF2BPs in cancer-a potential target for cancer therapy

Circular RNAs (circRNAs) are an interesting class of conserved single-stranded RNA molecules derived from exon or intron sequences produced by the reverse splicing of precursor mRNA. CircRNAs play important roles as microRNA sponges, gene splicing and transcriptional regulators, RNA-binding protein sponges, and protein/peptide translation factors. Abnormal functions of circRNAs and RBPs in tumor progression have been widely reported. Insulin-like growth factor-2 mRNA-binding proteins (IGF2BPs) are a highly conserved family of RBPs identified in humans that function as post-transcriptional fine-tuners of target transcripts. Emerging evidence suggests that IGF2BPs regulate the processing and metabolism of RNA, including its stability, translation, and localization, and participate in a variety of cellular functions and pathophysiology. In this review, we have summarized the roles and molecular mechanisms of circRNAs and IGF2BPs in cancer development and progression. In addition, we briefly introduce the role of other RNAs and IGF2BPs in cancer, discuss the current clinical applications and challenges faced by circRNAs and IGF2BPs, and propose future directions for this promising research field.

CircZFR promotes colorectal cancer progression via stabilizing BCLAF1 and regulating the miR-3127-5p/RTKN2 axis

Aberrant expression of circular RNAs (circRNAs) is frequently linked to colorectal cancer (CRC). Here, we identified circZFR as a promising biomarker for CRC diagnosis and prognosis. CircZFR was upregulated in CRC tissues and serum exosomes and its level was linked to cancer incidence, advanced-stages, and metastasis. In both in vitro and in vivo settings, circZFR promoted the growth and spread while suppressing apoptosis of CRC. Exosomes with circZFR overexpression promoted the proliferation and migration of cocultured CRC cells. Mechanistically, epithelial splicing regulatory protein 1 (ESRP1) in CRC cells may enhance the production of circZFR. BCL2-associated transcription factor 1 (BCLAF1) bound to circZFR, which prevented its ubiquitinated degradation. Additionally, circZFR sponged miR-3127-5p to boost rhotekin 2 (RTKN2) expression. Our TCP1-CD-QDs nanocarrier was able to carry and deliver circZFR siRNA (si-circZFR) to the vasculature of CRC tissues and cells, which inhibited the growth of tumors in patient-derived xenograft (PDX) models. Taken together, our results show that circZFR is an oncogenic circRNA, which promotes the development and spread of CRC in a BCLAF1 and miR-3127-5p-dependent manner. CircZFR is a possible serum biopsy marker for the diagnosis and a desirable target for further treatment of CRC.

The m6A regulators in prostate cancer: molecular basis and clinical perspective

Prostate cancer (PCa) is the second leading cause of cancer-related death among men in western countries. Evidence has indicated the significant role of the androgen receptor (AR) as the main driving factor in controlling the development of PCa, making androgen receptor inhibition (ARI) therapy a pivotal management approach. In addition, AR independent signaling pathways also contribute to PCa progression. One such signaling pathway that has garnered our attention is N6-Methyladenosine (m6A) signaling, which refers to a chemical modification on RNA with crucial roles in RNA metabolism and disease progression, including PCa. It is important to comprehensively summarize the role of each individual m6A regulator in PCa development and understand its interaction with AR signaling. This review aims to provide a thorough summary of the involvement of m6A regulators in PCa development, shedding light on their upstream and downstream signaling pathways. This summary sets the stage for a comprehensive review that would benefit the scientific community and clinical practice by enhancing our understanding of the biology of m6A regulators in the context of PCa.

M6A-methylated circPOLR2B forms an R-loop and regulates the biological behavior of glioma stem cells through positive feedback loops

Glioma is the most common primary brain tumor, and targeting glioma stem cells (GSCs) has become a key aspect of glioma treatment. In this study, we discovered a molecular network in which circRNA forms an R-loop structure with its parental gene to regulate the biological behavior of GSCs. Genes with abnormal expression in GSCs were screened using RNA-seq and circRNA microarray analyses. The study results showed that high expression of YTHDC1 in GSCs promoted the transportation of N6-methyladenosine (m6A)-modified circPOLR2B from the nucleus to the cytoplasm. Decreased circPOLR2B levels in the nucleus resulted in fewer R-loop structures formed with its parental gene POLR2B. This reduction in R-loop structures relieved the inhibitory effect on POLR2B transcription and upregulated PBX1 expression through alternative polyadenylation (APA) action, thereby promoting the malignant biological behavior of GSCs. Knockdown of YTHDC1, POLR2B, and PBX1 reduced xenograft tumor volume and prolonged the survival of nude mice. The YTHDC1/circPOLR2B/POLR2B/PBX1 axis plays a regulatory role in the biological behavior of GSCs, offering potential targets and novel strategies for the treatment of glioma.

NAT10 Promotes Prostate Cancer Growth and Metastasis by Acetylating mRNAs of HMGA1 and KRT8

N4-acetylcytidine (ac4C) is essential for the development and migration of tumor cells. According to earlier research, N-acetyltransferase 10 (NAT10) can increase messenger RNAs (mRNAs) stability by catalyzing the synthesis of ac4C. However, little is known about NAT10 expression and its role in the acetylation modifications in prostate cancer (PCa). Thus, the biological function of NAT10 in PCa is investigated in this study. Compared to paraneoplastic tissues, the expression of NAT10 is significantly higher in PCa. The NAT10 expression is strongly correlated with the pathological grade, clinical stage, Gleason score, T-stage, and N-stage of PCa. NAT10 has the ability to advance the cell cycle and the epithelial-mesenchymal transition (EMT), both of which raise the malignancy of tumor cells. Mechanistically, NAT10 enhance the stability of high mobility group AT-hook 1 (HMGA1) by acetylating its mRNA, thereby promoting cell cycle progression to improve cell proliferation. In addition, NAT10 improve the stability of Keratin 8 (KRT8) by acetylating its mRNA, which promotes the progression of EMT to improve cell migration. This findings provide a potential prognostic or therapeutic target for PCa.

METTL5: A Potential Biomarker for Nonsmall Cell Lung Cancer That Promotes Cancer Cell Proliferation by Interacting with IGF2BP3

Objective: To examine if METTL5 promotes the proliferation of nonsmall cell lung cancer (NSCLC) cells by interacting with IGF2BP3. Methods: The expression patterns of METTL5 and IGF2BP3 in NSCLC tissues, their relationship with survival rate, and their correlation were analyzed using bioinformatics and clinical sample analyses. The effects of METTL5 overexpression and IGF2BP3 knockdown, as well as those of METTL5 knockdown and IGF2BP3 overexpression, on the proliferation of NSCLC cells were analyzed by transfecting appropriate constructs. The interaction between METTL5 and IGF2BP3 was verified using the co-immunoprecipitation (Co-IP) assay. The in vivo effects of METTL5 and IGF2BP3 on NSCLC growth were analyzed using the tumor-bearing nude mouse model. Results: METTL5 and IGF2BP3 expression levels were positively correlated and were associated with poor clinical prognosis. The METTL5 and IGF2BP3 expression levels were upregulated in the clinical NSCLC samples. IGF2BP3 expression did not affect METTL5 expression but was regulated by METTL5. IGF2BP3 overexpression mitigated the METTL5 knockdown-induced impaired cell proliferation. Meanwhile, IGF2BP3 knockdown suppressed METTL5-mediated NSCLC cell proliferation. The Co-IP assay results revealed the interaction between METTL5 and IGF2BP3 in NSCLC cells. IGF2BP3 knockdown suppressed tumor growth, whereas IGF2BP3 overexpression enhanced tumor volume and quality. Conclusion: METTL5 induces NSCLC cell proliferation by interacting with IGF2BP3. Thus, METTL5 is a potential biomarker and a therapeutic target for NSCLC.

Circular RNA hsa_circ_0000467 promotes colorectal cancer progression by promoting eIF4A3-mediated c-Myc translation

BACKGROUND

Colorectal cancer (CRC) is the second most common malignant tumor worldwide, and its incidence rate increases annually. Early diagnosis and treatment are crucial for improving the prognosis of patients with colorectal cancer. Circular RNAs are noncoding RNAs with a closed-loop structure that play a significant role in tumor development. However, the role of circular RNAs in CRC is poorly understood.

METHODS

The circular RNA hsa_circ_0000467 was screened in CRC circRNA microarrays using a bioinformatics analysis, and the expression of hsa_circ_0000467 in CRC tissues was determined by in situ hybridization. The associations between the expression level of hsa_circ_0000467 and the clinical characteristics of CRC patients were evaluated. Then, the role of hsa_circ_0000467 in CRC growth and metastasis was assessed by CCK8 assay, EdU assay, plate colony formation assay, wound healing assay, and Transwell assay in vitro and in a mouse model of CRC in vivo. Proteomic analysis and western blotting were performed to investigate the effect of hsa_circ_0000467 on c-Myc signaling. Polysome profiling, RT‒qPCR and dual-luciferase reporter assays were performed to determine the effect of hsa_circ_0000467 on c-Myc translation. RNA pull-down, RNA immunoprecipitation (RIP) and immunofluorescence staining were performed to assess the effect of hsa_circ_0000467 on eIF4A3 distribution.

RESULTS

In this study, we found that the circular RNA hsa_circ_0000467 is highly expressed in colorectal cancer and is significantly correlated with poor prognosis in CRC patients. In vitro and in vivo experiments revealed that hsa_circ_0000467 promotes the growth and metastasis of colorectal cancer cells. Mechanistically, hsa_circ_0000467 binds eIF4A3 to suppress its nuclear translocation. In addition, it can also act as a scaffold molecule that binds eIF4A3 and c-Myc mRNA to form complexes in the cytoplasm, thereby promoting the translation of c-Myc. In turn, c-Myc upregulates its downstream targets, including the cell cycle-related factors cyclin D2 and CDK4 and the tight junction-related factor ZEB1, and downregulates E-cadherin, which ultimately promotes the growth and metastasis of CRC.

CONCLUSIONS

Our findings revealed that hsa_circRNA_0000467 plays a role in the progression of CRC by promoting eIF4A3-mediated c-Myc translation. This study provides a theoretical basis and molecular target for the diagnosis and treatment of CRC.

SLC25A19 is a novel prognostic biomarker related to immune invasion and ferroptosis in HCC

SLC25A19 is a mitochondrial thiamine pyrophosphate (TPP) carrier that mediates TPP entry into the mitochondria. SLC25A19 has been recognized to play a crucial role in many metabolic diseases, but its role in cancer has not been clearly reported. Based on clinical data from The Cancer Genome Atlas (TCGA), the following parameters were analyzed among HCC patients: SLC25A19 expression, enrichment analyses, immune infiltration, ferroptosis and prognosis analyses. In vitro, the SLC25A19 high expression was validated by qRT-PCR and Immunohistochemistry. Subsequently, a series of cell function experiments, including CCK8, EdU, clone formation, trans-well and scratch assays, were conducted to illustrate the effect of SLC25A19 on the growth and metastasis of cancer cells. Meanwhile, indicators related to ferroptosis were also detected. SCL25A19 is highly expressed in HCC and predicts a poor prognosis. Elevated SLC25A19 expression in HCC patients was markedly associated with T stage, pathological status (PS), tumor status (TS), histologic grade (HG), and AFP. Our results indicate that SLC25A19 has a generally good prognosis predictive and diagnostic ability. The results of gene enrichment analyses showed that SLC25A19 is significantly correlated with immune infiltration, fatty acid metabolism, and ferroptosis marker genes. In vitro experiments have confirmed that silencing SLC25A19 can significantly inhibit the proliferation and migration ability of cancer cells and induce ferroptosis in HCC. In conclusion, these findings indicate that SLC25A19 is novel prognostic biomarker related to immune invasion and ferroptosis in HCC, and it is an excellent candidate for therapeutic target against HCC.

Hypoxia-enhanced YAP1-EIF4A3 interaction drives circ_0007386 circularization by competing with CRIM1 pre-mRNA linear splicing and promotes non-small cell lung cancer progression

BACKGROUND

The progression of non-small cell lung cancer (NSCLC) is significantly influenced by circular RNAs (circRNAs), especially in tumor hypoxia microenvironment. However, the precise functions and underlying mechanisms of dysregulated circRNAs in NSCLC remain largely unexplored.

METHODS

Differentially expressed circRNAs in NSCLC tissues were identified through high-throughput RNA sequencing. The characteristics of circ_0007386 were rigorously confirmed via Sanger sequencing, RNase R treatment and actinomycin D treatment. The effects of circ_0007386 on proliferation and apoptosis were investigated using CCK8, cloning formation assays, TUNEL staining, and flow cytometry assays in vitro. In vivo, xenograft tumor models were used to evaluate its impact on proliferation. Mechanistically, the regulatory relationships of circ_0007386, miR-383-5p and CIRBP were examined through dual luciferase reporter assays and rescue experiments. Additionally, we detected the binding of EIF4A3 to CRIM1 pre-mRNA by RNA immunoprecipitation and the interaction between YAP1 and EIF4A3 under hypoxic conditions by co-immunoprecipitation.

RESULTS

Our investigation revealed a novel circRNA, designated as circ_0007386, that was upregulated in NSCLC tissues and cell lines. Circ_0007386 modulated proliferation and apoptosis in NSCLC both in vitro and in vivo. Functionally, circ_0007386 acted as a sponge for miR-383-5p, targeting CIRBP, which influenced NSCLC cell proliferation and apoptosis via the PI3K/AKT signaling pathway. Furthermore, under hypoxic conditions, the interaction between YAP1 and EIF4A3 was enhanced, leading to the displacement of EIF4A4 from binding to CRIM1 pre-mRNA. This facilitated the back-splicing of CRIM1 pre-mRNA, increasing the formation of circ_0007386. The circ_0007386/miR-383-5p/CIRBP axis was significantly associated with the clinical features and prognosis of NSCLC patients.

CONCLUSIONS

Circ_0007386, regulated by YAP1-EIF4A3 interaction under hypoxia conditions, plays an oncogenic role in NSCLC progression via the miR-383-5p/CIRBP axis.

Recent advances in the reciprocal regulation of m6A modification with non-coding RNAs and its therapeutic application in acute myeloid leukemia

N6-methyladenosine (m6A) is one of the most common modifications of RNA in eukaryotic cells and is involved in mRNA metabolism, including stability, translation, maturation, splicing, and export. m6A also participates in the modification of multiple types of non-coding RNAs, such as microRNAs, long non-coding RNAs, and circular RNAs, thereby affecting their metabolism and functions. Increasing evidence has revealed that m6A regulators, such as writers, erasers, and readers, perform m6A-dependent modification of ncRNAs, thus affecting cancer progression. Moreover, ncRNAs modulate m6A regulators to affect cancer development and progression. In this review, we summarize recent advances in understanding m6A modification and ncRNAs and provide insights into the interaction between m6A modification and ncRNAs in cancer. We also discuss the potential clinical applications of the mechanisms underlying the interplay between m6A modifications and ncRNAs in acute myeloid leukemia (AML). Therefore, clarifying the mutual regulation between m6A modifications and ncRNAs is of great significance to identify novel therapeutic targets for AML and has great clinical application prospects.

Exploring the oncogenic potential of circSOD2 in clear cell renal cell carcinoma: a novel positive feedback loop

BACKGROUND

Existing studies have found that circular RNAs (circRNAs) act as sponges for micro RNAs (miRNAs) to control downstream genes. However, the specific functionalities and mechanisms of circRNAs in human clear cell renal cell carcinoma (ccRCC) have yet to be thoroughly investigated.

METHODS

Patient cohorts from online databases were used to screen candidate circRNAs, while another cohort from our hospital was obtained for validation. CircSOD2 was identified as a potential oncogenic target, and its relevant characteristics were investigated during ccRCC progression through various assays. A positive feedback loop containing downstream miRNA and its target gene were identified using bioinformatics and validated by luciferase reporter assays, RNA pull-down, and high-throughput sequencing.

RESULTS

CircSOD2 expression was elevated in tumor samples and significantly correlated with overall survival (OS) and the tumor stage of ccRCC patients, which appeared in the enhanced proliferation, invasion, and migration of tumor cells. Through competitive binding to circSOD2, miR-532-3p can promote the expression of PAX5 and the progression of ccRCC, and such regulation can be salvaged by miR-532-3p inhibitor.

CONCLUSION

A novel positive feedback loop, PAX5/circSOD2/miR-532-3p/PAX5 was identified in the study, indicating that the loop may play an important role in the diagnosis and prognostic prediction in ccRCC patients.

circSORBS1 inhibits lung cancer progression by sponging miR-6779-5p and directly binding RUFY3 mRNA

Lung cancer is the primary cause of cancer-related death worldwide, and its global incidence and mortality rates remain high. The differential expression of circular RNAs (circRNAs) can affect the development of cancer, but the mechanisms by which circRNAs regulate lung cancer progression remain unclear. In this study, we identified circSORBS1, a circRNA that has not been previously described in lung cancer and is significantly underexpressed in lung cancer tissues, blood and cell lines, and the low expression of circSORBS1 correlated with tumour grade and prognosis. In vitro and in vivo functional experiments revealed that circSORBS1 overexpression inhibited cell proliferation and migration while enhancing apoptosis. Mechanistically, circSORBS1 acts as a sponge for miR-6779-5p, indirectly inhibiting RUFY3 mRNA degradation. Simultaneously, it binds to RUFY3 mRNA to enhance its stability. This dual regulatory mechanism leads to an increase in RUFY3 protein levels, which ultimately activates the YWHAE/BAD/BCL2 apoptotic signalling pathway and suppresses lung cancer progression. Our findings not only increase the knowledge about the regulatory pattern of circRNA expression but also provide new insights into the mechanisms by which circRNAs regulate lung cancer development.

Circ_0007534 promotes cholangiocarcinoma stemness and resistance to anoikis through DDX3X-mediated positive feedback regulation of parental gene DDX42

Cholangiocarcinoma (CCA) is a malignancy with an extremely poor prognosis, and much remains unknown about its pathogenesis and treatment modalities. Circular RNA (circRNA) has been proven to play regulatory roles in various tumorigenesis, yet its potential function and mechanism in cholangiocarcinoma require further investigation. This study is the first to identify the aberrant expression and functional role of a novel circRNA, circ_0007534, derived from the DDX42 gene, in cholangiocarcinoma. Compared to the normal control group, the expression of circ_0007534 was significantly elevated in the tissues and cells with CCA and that high expression correlated with lymph node invasion and poor prognosis. Functional experiments indicated that downregulating circ_0007534 markedly inhibited the proliferation, migration, invasion, stemness, and anti-anoikis ability of CCA cells, as well as the tumor growth and liver and lung metastasis in nude mice. Mechanistic studies revealed that DDX42, as the parent gene of circ_0007534, can mutually regulate each other's expression. Predominantly located in the cytoplasm, circ_0007534 can form a complex with the RNA-binding protein DDX3X, which enhances the stability of DDX42 mRNA, thereby upregulating the expression of DDX42. This creates a positive feedback loop among the three, collectively promoting the progression of cholangiocarcinoma. In conclusion, this study sheds light on the pivotal role and molecular mechanism of circ_0007534 in the development of CCA, offering potential new targets for early diagnosis and treatment.

Role of N6‑methyladenosine in the pathogenesis, diagnosis and treatment of prostate cancer (Review)

Prostate cancer (PCa) affects males of all racial and ethnic groups, and leads to higher rates of mortality in those belonging to a lower socioeconomic status due to the late detection of the disease. PCa affects middle‑aged males between the ages of 45 and 60 years, and is the highest cause of cancer‑associated mortality in Western countries. As the most abundant and common mRNA modification in higher eukaryotes, N6‑methyladenosine (m6A) is widely distributed in mammalian cells and influences various aspects of mRNA metabolism. Recent studies have found that abnormal expression levels of various m6A regulators significantly affect the development and progression of various types of cancer, including PCa. The present review discusses the influence of m6A regulatory factors on the pathogenesis and progression of PCa through mRNA modification based on the current state of research on m6A methylation modification in PCa. It is considered that the treatment of PCa with micro‑molecular drugs that target the epigenetics of the m6A regulator to correct abnormal m6A modifications is a direction for future research into current diagnostic and therapeutic approaches for PCa.

Insights into the role of the N6-methyladenosine reader IGF2BP3 in the progression of oral squamous cell carcinoma and its connection to cell-cycle control

The genome of oral squamous cell carcinoma (OSCC) has been extensively characterized via bulk sequencing, revealing a multitude of genetic changes. The gene IGF2BP3, which encodes for the insulin-like growth factor 2 mRNA-binding protein 3, has been observed to be highly expressed in several types of cancer. This finding suggests that IGF2BP3 may play a significant role in the initiation and advancement of cancer. Nevertheless, the mechanisms by which IGF2BP3 contribute to OSCC are yet to be fully understood. In this study, we have observed that IGF2BP3 exhibits overexpression in OSCC. Based on our findings from bulk sequencing analysis, we have concluded that IGF2BP3 could potentially serve as a biomarker for predicting poor prognosis in OSCC. Moreover, it has been demonstrated that IGF2BP3 exhibits a significant association with the initiation and advancement of tumors both in vivo and in vitro. The evaluation of IGF2BP3 expression levels in relation to the cell cycle stage was conducted using single-cell RNA sequencing data. Tumor cells characterized by elevated IGF2BP3 expression demonstrated a higher percentage of cells in the G2/M transition phase. This study presents new findings indicating that the molecular target IGF2BP3 can serve as a prognostic indicator for tumors and has an impact on the development and progression of OSCC by influencing the regulation of the cell cycle.

Genetic variation of circHIBADH enhances prostate cancer risk through regulating HNRNPA1-related RNA splicing

The current study aimed to investigate associations of circRNAs and related genetic variants with the risk of prostate cancer (PCa) as well as to elucidate biological mechanisms underlying the associations. We first compared expression levels of circRNAs between 25 paired PCa and adjacent normal tissues to identify risk-associated circRNAs by using the MiOncoCirc database. We then used logistic regression models to evaluate associations between genetic variants in candidate circRNAs and PCa risk among 4662 prostate cancer patients and 3114 healthy controls, and identified circHIBADH rs11973492 T>C as a significant risk-associated variant (odds ratio = 1.20, 95% confidence interval: 1.08-1.34, P = 7.06 × 10 -4) in a dominant genetic model, which altered the secondary structure of the corresponding RNA chain. In the in silico analysis, we found that circHIBADH sponged and silenced 21 RNA-binding proteins (RBPs) enriched in the RNA splicing pathway, among which HNRNPA1 was identified and validated as a hub RBP using an external RNA-sequencing data as well as the in-house (four tissue samples) and publicly available single-cell transcriptomes. Additionally, we demonstrated that HNRNPA1 influenced hallmarks including MYC target, DNA repair, and E2F target signaling pathways, thereby promoting carcinogenesis. In conclusion, genetic variants in circHIBADH may act as sponges and inhibitors of RNA splicing-associated RBPs including HNRNPA1, playing an oncogenic role in PCa.

IGF2BP3 promotes glutamine metabolism of endometriosis by interacting with UCA1 to enhances the mRNA stability of GLS1

BACKGROUND

Insulin like growth factor II mRNA binding protein 3 (IGF2BP3) has been implicated in numerous inflammatory and cancerous conditions. However, its precise molecular mechanisms in endometriosis (EMs) remains unclear. The aim of this study is to examine the influence of IGF2BP3 on the occurrence and progression of EMs and to elucidate its underlying molecular mechanism.

METHODS

Efects of IGF2BP3 on endometriosis were confrmed in vitro and in vivo. Based on bioinformatics analysis, RNA immunoprecipitation (RIP), RNA pull-down assays and Fluorescent in situ hybridization (FISH) were used to show the association between IGF2BP3 and UCA1. Single-cell spatial transcriptomics analysis shows the expression distribution of glutaminase 1 (GLS1) mRNA in EMs. Study the effect on glutamine metabolism after ectopic endometriotic stromal cells (eESCs) were transfected with Sh-IGF2BP3 and Sh-UCA1 lentivirus.

RESULTS

Immunohistochemical staining have revealed that IGF2BP3 was upregulated in ectopic endometriotic lesions (EC) compared to normal endometrial tissues (EN). The proliferation and migration ability of eESCs were greatly reduced by downregulating IGF2BP3. Additionally, IGF2BP3 has been observed to interact with urothelial carcinoma associated 1 (UCA1), leading to increased stability of GLS1 mRNA and subsequently enhancing glutamine metabolism. Results also demonstrated that IGF2BP3 directly interacts with the 3' UTR region of GLS1 mRNA, influencing its expression and stability. Furthermore, UCA1 was able to bind with c-MYC protein, stabilizing c-MYC mRNA and consequently enhancing GLS1 expression through transcriptional promotion.

CONCLUSION

These discoveries underscored the critical involvement of IGF2BP3 in the elevation and stability of GLS1 mRNA in the context of glutamine metabolism by interacting with UCA1 in EMs. The implications of our study extended to the identification of possible therapeutic targets for individuals with EMs.

Circular RNAs in EMT-driven metastasis regulation: modulation of cancer cell plasticity, tumorigenesis and therapy resistance

The non-coding RNAs comprise a large part of human genome lack of capacity in encoding functional proteins. Among various members of non-coding RNAs, the circular RNAs (circRNAs) have been of importance in the pathogenesis of human diseases, especially cancer. The circRNAs have a unique closed loop structure and due to their stability, they are potential diagnostic and prognostic factors in cancer. The increasing evidences have highlighted the role of circRNAs in the modulation of proliferation and metastasis of cancer cells. On the other hand, metastasis has been responsible for up to 90% of cancer-related deaths in patients, requiring more investigation regarding the underlying mechanisms modulating this mechanism. EMT enhances metastasis and invasion of tumor cells, and can trigger resistance to therapy. The cells demonstrate dynamic changes during EMT including transformation from epithelial phenotype into mesenchymal phenotype and increase in N-cadherin and vimentin levels. The process of EMT is reversible and its reprogramming can disrupt the progression of tumor cells. The aim of current review is to understanding the interaction of circRNAs and EMT in human cancers and such interaction is beyond the regulation of cancer metastasis and can affect the response of tumor cells to chemotherapy and radiotherapy. The onco-suppressor circRNAs inhibit EMT, while the tumor-promoting circRNAs mediate EMT for acceleration of carcinogenesis. Moreover, the EMT-inducing transcription factors can be controlled by circRNAs in different human tumors.

Circ_0053943 complexed with IGF2BP3 drives uveal melanoma progression via regulating N6-methyladenosine modification of Epidermal growth factor receptor

Numerous studies have characterized the critical role of circular RNAs (circRNAs) as regulatory factors in the progression of multiple cancers. However, the biological functions of circRNAs and their underlying molecular mechanisms in the progression of uveal melanoma (UM) remain enigmatic. In this study, we identified a novel circRNA, circ_0053943, through re-analysis of UM microarray data and quantitative RT-PCR. Circ_0053943 was found to be upregulated in UM and to promote the proliferation and metastatic ability of UM cells in both in vitro and in vivo settings. Mechanistically, circ_0053943 was observed to bind to the KH1 and KH2 domains of insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3), thereby enhancing the function of IGF2BP3 by stabilizing its target mRNA. RNA sequencing assays identified epidermal growth factor receptor (EGFR) as a target gene of circ_0053943 and IGF2BP3 at the transcriptional level. Rescue assays demonstrated that circ_0053943 exerts its biological function by stabilizing EGFR mRNA and regulating the downstream mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) signaling pathway. Collectively, circ_0053943 may promote UM progression by stabilizing EGFR mRNA and activating the MAPK/ERK signaling pathway through the formation of a circ_0053943/IGF2BP3/EGFR RNA-protein ternary complex, thus providing a potential biomarker and therapeutic target for UM.

CircPRMT5 promotes progression of osteosarcoma by recruiting CNBP to regulate the translation and stability of CDK6 mRNA

Research has demonstrated that circular RNAs (circRNAs) exert critical functions in the occurrence and progression of numerous malignant tumors. CircPRMT5 was recently reported to be involved in the pathogenesis of cancers. However, the potential role of circPRMT5 in osteosarcoma needs further investigation. In present study, our results suggested that circPRMT5 was highly upregulated in osteosarcoma cells and mainly localizes in the cytoplasm. CircPRMT5 promoted the proliferation, migration and invasion capacities of osteosarcoma cells, and suppressed cell apoptosis. Knockdown of circPRMT5 exerted the opposite effects. Mechanically, circPRMT5 promoted the binding of CNBP to CDK6 mRNA, which enhanced the stability of CDK6 mRNA and facilitated its translation, thereby promoting the progression of osteosarcoma. Knockdown of CDK6 reversed the promoting effect of circPRMT5 on osteosarcoma cells. These findings suggest that circPRMT5 promotes osteosarcoma cell malignant activity by recruiting CNBP to regulate the translation and stability of CDK6 mRNA. Thus, circPRMT5 may represent a promising therapeutic target for osteosarcoma.

IGF2BPs as novel m6A readers: Diverse roles in regulating cancer cell biological functions, hypoxia adaptation, metabolism, and immunosuppressive tumor microenvironment

m6A methylation is the most frequent modification of mRNA in eukaryotes and plays a crucial role in cancer progression by regulating biological functions. Insulin-like growth factor 2 mRNA-binding proteins (IGF2BP) are newly identified m6A 'readers'. They belong to a family of RNA-binding proteins, which bind to the m6A sites on different RNA sequences and stabilize them to promote cancer progression. In this review, we summarize the mechanisms by which different upstream factors regulate IGF2BP in cancer. The current literature analyzed here reveals that the IGF2BP family proteins promote cancer cell proliferation, survival, and chemoresistance, inhibit apoptosis, and are also associated with cancer glycolysis, angiogenesis, and the immune response in the tumor microenvironment. Therefore, with the discovery of their role as 'readers' of m6A and the characteristic re-expression of IGF2BPs in cancers, it is important to elucidate their mechanism of action in the immunosuppressive tumor microenvironment. We also describe in detail the regulatory and interaction network of the IGF2BP family in downstream target RNAs and discuss their potential clinical applications as diagnostic and prognostic markers, as well as recent advances in IGF2BP biology and associated therapeutic value.

Hsa_circ_0079875 functions as a competitive endogenous RNA to promote hepatocellular carcinoma progression

Circular RNA (circRNA) can influence the development of hepatocellular carcinoma (HCC) as a competitive endogenous RNA (ceRNA). However, there are still many circRNAs whose functions are unknown. Our research explores the role of a novel circRNA, hsa_circ_0079875, in HCC. The expression of hsa_circ_0079875 in HCC was verified by next-generation sequencing, quantitative reverse transcription-polymerase chain reaction (qRT-PCR), and fluorescence in situ hybridization (FISH). The distribution of hsa_circ_0079875 in HCC cells was investigated by RNA subcellular isolation and FISH assays. The functional effects on HCC proliferation, invasion, migration, cell cycle, and apoptosis were verified by overexpression and knockdown of hsa_circ_0079875. Moreover, xenograft mouse models and immunohistochemistry experiments were used to assess the function of hsa_circ_0079875 in vivo. Hsa_circ_0079875 was up-regulated in HCC tissues and mainly distributed in the cytoplasm. Higher hsa_circ_0079875 leads to larger tumor tissue, more microvascular invasion(MVI) and higher AFP levels, which in turn leads to a poor prognosis. Overexpression of hsa_circ_0079875 can promote the proliferation, migration, and invasion of HCC cells and inhibit apoptosis in vitro and in vivo. Knocking down hsa_circ_0079875 has the opposite effect. Sequencing and biological information predicted the target miRNA and mRNA of hsa_circ_0079875. Further bioinformatics and clinical correlation analysis revealed that hsa_circ_0079875 promote the malignant biological behaviors of HCC through hsa_circ_0079875/miR-519d-59/NRAS ceRNA net. Therefore, hsa_circ_0079875 can be a potential prognostic marker and therapeutic target for HCC.

LncRNA DGUOK-AS1 Promotes Cell Progression in Lung Squamous Cell Carcinoma by Regulation of miR-653-5p/SLC6A15 Axis

Long noncoding RNA (lncRNA) plays a key role in regulating cancer development. LncRNA deoxyguanosine kinase antisense RNA 1 (DGUOK-AS1) has been reported as a promoter in tumor. The work was designed to further investigate the mechanism of action of DGUOK-AS1 in lung squamous cell carcinoma (LUSC). DGUOK-AS1 level in LUSC cells was measured using RT-qPCR. Counting Kit-8 assays and colony forming assays were performed to evaluate LUSC cell viability and proliferation. Transwell assays were performed to detect cell migration and invasion. Luciferase reporter and RNA pulldown assays were used to verify the binding capacity of DGUOK-AS1 and miR-653-5p. RNA immunoprecipitation assays were performed to verify the relationship of DGUOK-AS1, miR-653-5p, and SLC6A15. DGUOK-AS1 was highly expressed in LUSC cells. DGUOK-AS1 knockdown suppressed LUSC cell proliferation, migration, and invasion. SLC6A15 was demonstrated to be targeted by miR-653-5p, and DGUOK-AS1 interacted with miR-653-5p to modulate SLC6A15 level in LUSC cells. Overexpression of SLC6A15 reversed the suppressive effects of DGUOK-AS1 knockdown on LUSC cell processes. In conclusion, DGUOK-AS1 promotes malignant behaviors of LUSC cells by upregulating SLC6A15 level through interaction with miR-653-5p.

Circ_0082878 contributes to prostate cancer progression via the miR-455-3p/WTAP axis

Circ_0082878 has been found to be strongly expressed in prostate cancer (PCa). However, its roles and potential mechanism in PCa have not been investigated. This study aims to clarify it. RNase R digestion method was adopted for verifying the circular structure of circ_0082878. RT-qPCR assay is aimed to detect the expressions of circ_0082878, miR-455-3p and WTAP in PCa tissues and cells. For identifying cell proliferation, migration and invasion abilities, CCK-8 and transwell assay were used. To show the correlation between miR-455-3p and WTAP or circ_0082878, the luciferase reporter gene, RNA RIP and RNA pull-down experiments were employed. We employed western blot to detect protein level of WTAP. In addition, the impact of circ_0082878 on PCa cells in vivo was also studied. It was found that circ_0082878 and WTAP were highly expressed in PCa tissues and cells, whereas miR-455-3p was lowly expressed. Inhibition of circ_0082878 restrained the growth of PCa in vitro and in vivo. Regarding mechanism, miR-455-3p was the target of circ_0082878, and WTAP was the target of miR-455-3p. Circ_0082878 could downregulate the level of miR-455-3p, and inhibiting of miR-455-3p expression could partially eliminate the inhibitory impact of low expression of circ_0082878 on the proliferation and migration of PCa cells. Additionally, over-expression of miR-455-3p resulted in the reduced level of WTAP, and WTAP over-expression counteracted the tumor suppressive impact of miR-455-3p in PCa cells. Moreover, the obtained findings indicated that circ_0082878 may exert tumor-promoting activity in PCa via sponging miR-455-3p and then upregulating WTAP. This indicates that the circ_0082878/miR-455-3p/WTAP axis can probably become the possible therapeutic target for PCa.

Atractylodes macrocephala III suppresses EMT in cervical cancer by regulating IGF2BP3 through ETV5

Atractylodes macrocephala III (ATL III), with anti-inflammatory and antitumor effects, is the main compound of Atractylodes macrocephala. Whether ATL III has an effect on cervical cancer and the specific mechanism are still unclear. Here, we investigated the effects of ATL III on cervical cancer cells at different concentrations and found that ATL III downregulates insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3), which was found to be highly expressed in cervical cancer tissue by RNA-Seq. In this study, we found that ATL III promotes apoptosis and regulates epithelial-mesenchymal transition (EMT) in cervical cancer cells (HeLa and SiHa cells) and that IGF2BP3 is a common target gene of ATL III in HeLa and SiHa cells. The expression level of IGF2BP3 in cervical cancer cells was proportional to their migration and invasion abilities. This was verified by transfection of cells with a small interfering RNA and an IGF2BP3 overexpression plasmid. After ATL III treatment, the migration and invasion abilities of cervical cancer cells were obviously reduced, but these effects were attenuated after overexpression of IGF2BP3. In addition, the transcription factor IGF2BP3 was predicted by the JASPAR system. After intersection with our sequencing results, we verified the promotional effect of ETV5 (ETS translocation variant 5) on IGF2BP3 and found that ALT III inhibited ETV5. In general, our research showed that ATL III inhibits the migration and invasion of cervical cancer cells by regulating IGF2BP3 through ETV5.

The role of the methyltransferase METTL3 in prostate cancer: a potential therapeutic target

The incidence of prostate cancer (PCa), the most prevalent malignancy, is currently at the forefront. RNA modification is a subfield of the booming field of epigenetics. To date, more than 170 types of RNA modifications have been described, and N6-methyladenosine (m6A) is the most abundant and well-characterized internal modification of mRNAs involved in various aspects of cancer progression. METTL3, the first identified key methyltransferase, regulates human mRNA and non-coding RNA expression in an m6A-dependent manner. This review elucidates the biological function and role of METTL3 in PCa and discusses the implications of METTL3 as a potential therapeutic target for future research directions and clinical applications.

Identification of circATG9A as a novel biomarker for renal cell carcinoma

The incidence and mortality rates of renal cell carcinoma (RCC) have rapidly increased worldwide. To gain new insights into the regulatory role of circular RNAs (circRNAs) in RCC progression, we conducted RNA sequencing on three pairs of ccRCC and adjacent normal tissues. RT-PCR was utilized to analyze RNA expression. We investigated the effects of circATG9A on RCC cells through various assays including CCK-8, Transwell, wound healing, and colony formation assays. Furthermore, we employed FISH, RNA pull-down, luciferase reporter, and RIP assays to elucidate the mechanism by which circATG9A regulates RCC. Ultimately, we identified 118 differentially expressed circRNAs in RCC, including a novel circRNA, circATG9A, which was found to promote RCC progression both in vitro and in vivo. Moreover, mRNA sequencing, western blotting, and rescue experiments indicated that TRPM3 is the target of circATG9A in RCC progression. Bioinformatic analysis, RNA pull-down, FISH, and RIP assays suggested that circATG9A regulates TRPM3 expression by acting as a sponge for miR-497-5p. Finally, Western blotting revealed that circATG9A promotes the epithelial-mesenchymal transition (EMT) process through the Wnt/β-catenin signaling pathway. Our findings demonstrate that circATG9A is a novel circRNA upregulated in RCC that plays a crucial role in the EMT process through the miR-497-5p/TRPM3/Wnt/β-catenin axis. These results suggest that circATG9A could be a promising target for RCC prognosis and therapy.

The role of RNA modification in urological cancers: mechanisms and clinical potential

RNA modification is a post-transcriptional level of regulation that is widely distributed in all types of RNAs, including mRNA, tRNA, rRNA, miRNA, and lncRNA, where N6-methyladenine (m6A) is the most abundant mRNA methylation modification. Significant evidence has depicted that m6A modifications are closely related to human diseases, especially cancer, and play pivotal roles in RNA transcription, splicing, stabilization, and translation processes. The most common urological cancers include prostate, bladder, kidney, and testicular cancers, accounting for a certain proportion of human cancers, with an ever-increasing incidence and mortality. The recurrence, systemic metastasis, poor prognosis, and drug resistance of urologic tumors have prompted the identification of new therapeutic targets and mechanisms. Research on m6A modifications may provide new solutions to the current puzzles. In this review, we provide a comprehensive overview of the key roles played by RNA modifications, especially m6A modifications, in urologic cancers, as well as recent research advances in diagnostics and molecularly targeted therapies.

A novel circular RNA, circMAML3, promotes tumor progression of prostate cancer by regulating miR-665/MAPK8IP2 axis

Many studies have now demonstrated that circRNAs are aberrantly expressed in cancer and are involved in the regulation of malignant tumor progression. However, the role of circMAML3 (hsa_circ_0125392) in prostate cancer has not been reported. circMAML3 was selected from public data through screening. The circMAML3 circular characterization was performed using Sanger sequencing, agarose gel electrophoresis assay, RNase R assay and actinomycin D assay. The expression of circMAML3 in prostate cancer tissues and cells was detected by qRT-PCR. In vivo and in vitro experiments were conducted to investigate the biological functions of circMAML3 in prostate cancer. Finally, the underlying mechanism of circMAML3 was revealed by qRT-PCR, luciferase reporter assay, miRNA Pulldown, RNA immunoprecipitation, western blotting, and rescue assay. Compared to normal prostate tissue and prostate epithelial cells, circMAML3 is highly expressed in prostate cancer tissues and cell lines. CircMAML3 overexpression promotes prostate cancer proliferation and metastasis, while knockdown of circMAML3 exerts the opposite effect. Mechanistically, circMAML3 promotes prostate cancer progression by upregulating MAPK8IP2 expression through sponge miR-665. Our research indicates that circMAML3 promotes prostate cancer progression through the circMAML3/miR-665/MAPK8IP2 axis. circMAML3 and MAPK8IP2 are upregulated in prostate cancer expression and play an oncogenic role, whereas miR-665 is downregulated in prostate cancer and plays an oncogenic role. Therefore, CircMAML3 may be a potential biomarker for prostate cancer diagnosis, treatment and prognosis.

Torachrysone-8-O-β-d-glucoside mediates anti-inflammatory effects by blocking aldose reductase-catalyzed metabolism of lipid peroxidation products

Aldose reductase (AR) is an important enzyme involved in the reduction of various aldehyde and carbonyl compounds, including the highly reactive and toxic 4-hydroxynonenal (4-HNE), which has been linked to the progression of various pathologies such as atherosclerosis, hyperglycemia, inflammation, and tumors. AR inhibitors have potential therapeutic benefits for these diseases by reducing lipid peroxidation and mitigating the harmful effects of reactive aldehydes. In this study, we found that torachrysone-8-O-β-d-glucoside (TG), a natural product isolated from Polygonum multiflorum Thunb., functions as an effective inhibitor of AR, exhibiting potent effects in clearing reactive aldehydes and reducing inflammation. TG up-regulated the mRNA levels of several antioxidant factors downstream of NRF2, especially glutathione S-transferase (GST), which is significantly increased, thus detoxifying 4-HNE by facilitating the conjugation of 4-HNE to glutathione, forming glutathione-4-hydroxynonenal (GS-HNE). By employing a combination of molecular docking, cellular thermal shift assay, and enzyme activity experiments, we demonstrated that TG exhibited strong binding affinity with AR and inhibited its activity and blocked the conversion of GS-HNE to glutathionyl-1,4-dihydroxynonene (GS-DHN), thereby preventing the formation of protein adducts and inducing severe cellular damage. This study provides novel insights into the anti-inflammatory mechanisms of AR inhibitors and offers potential avenues for developing therapeutic strategies for AR-related pathologies. Our findings suggest that TG, as an AR inhibitor, may hold promise as a therapeutic agent for treating conditions characterized by excessive lipid peroxidation and inflammation. Further investigations are needed to fully explore the clinical potential of TG and evaluate its efficacy in the treatment and management of these complex diseases.

CircDHRS3 inhibits prostate cancer cell proliferation and metastasis through the circDHRS3/miR-421/MEIS2 axis

Prostate cancer is the most prevalent type of cancer among men worldwide. The importance of circular RNA (circRNA) in prostate cancer and its connection to malignancy has been steadily recognized. circRNA expression was obtained by circRNA sequencing of prostate cancer. circRNA and its function were further analysed. The results were verified by qRT-PCR, RIP assay, FISH, RNA pulldown, WB, CCK-8, colony formation assay and wound-healing assay. BALB/c Nude mice were used for xenograft hosts. Low expression of circDHRS3 was assessed in prostate cancer. Overexpression of circDHRS3 inhibited prostate cancer growth and migration in vitro. Additionally, miR-421 was shown to be the downstream target of circDHRS3, as shown by fluorescence in situ hybridization and dual-luciferase experiments. The rescue assay results for the PC3 and Du145 cell lines demonstrated that circDHRS3 inhibits prostate cancer cell lines' ability to proliferate and metastasize by modulating MEIS2 expression through the circDHRS3/miR-421/MEIS2 axis. In vivo investigations confirmed that the overexpression of circDHRS3 could inhibit both the lung and bone metastasis of prostate cancer cells. circDHRS3 has the potential to become a biomarker and a targeted therapeutic site for prostate cancer, particularly in the malignant stage. Our study indicates that circDHRS3 inhibits prostate cancer cell proliferation and metastasis through the circDHRS3/miR-421/MEIS2 axis.

Circular circRANGAP1 Contributes to Non-small Cell Lung Cancer Progression by Increasing COL11A1 Expression Through Sponging miR-653-5p

Numerous studies have discovered that hsa_circ_0063526 (also known as circRANGAP1) is an oncogenic circular RNA (circRNA) in some human tumors, including non-small cell lung cancer (NSCLC). However, the concrete molecular mechanism of circRANGAP1 involved in NSCLC is not completely elucidated. CircRANGAP1, microRNA-653-5p (miR-653-5p), and Type XI collagen (COL11A1) contents were determined via real-time quantitative polymerase chain reaction (RT-qPCR). Cell proliferative ability, migration, and invasion were measured using 5-ethynyl-2'-deoxyuridine (EdU), colony formation, wound healing, and transwell assays. E-cadherin, N-cadherin, Vimentin, and COL11A1 protein levels were detected via western blot assay. After Starbase software prediction, the binding between miR-653-5p and circRANGAP1 or COL11A1 was verified using a dual-luciferase reporter assay. Besides, the role of circRANGAP1 on tumor cell growth was analyzed using a xenograft tumor model in vivo. Increased circRANGAP1 and COL11A1, and reduced miR-653-5p were found in NSCLC tissues and cell lines. Furthermore, circRANGAP1 absence might hinder NSCLC cell proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) in vitro. Mechanically, circRANGAP1 functioned as a sponge of miR-653-5p to increase COL11A1 expression. In vivo experiments illustrated that circRANGAP1 knockdown repressed tumor growth. CircRANGAP1 silencing might suppress NSCLC cell malignant biological behaviors, at least in part, through the miR-653-5p/COL11A1 axis. These results provided a promising strategy for treating NSCLC malignancies.

CircTENM3 inhibites tumor progression via the miR-558/RUNX3 axis in prostate cancer

BACKGROUND

Prostate cancer (PCa) is currently acknowledged as the second most widespread cancer among men worldwide. Yet, the lack of dependable diagnostic biomarkers and therapeutic targets has presented considerable hurdles to the progression of prostate cancer treatment. Circular RNAs are implicated in the pathogenesis of numerous diseases, positioning them as promising biomarkers for diverse medical conditions. This study aims to uncover a specific circRNA that could serve as a diagnostic and therapeutic target for detecting and treating PCa.

METHODS

The change of circTENM3 expression levels in PCa was detected by qPCR. CCK8 assays, EdU assays, Scratch assay and Transwell migration assay conducted to detect the role of circTENM3 in PCa cells in vitro. RIP assay, RNA-pull down and luciferase reporter assay were performed to explore the mechanism of circTENM3. Gain-of-function analysis was performed to reveal the function of circTENM3 in PCa in vivo.

RESULTS

The results revealed that the expression level of circTENM3 was significantly down-regulated in PCa. CircTENM3 overexpression alleviated the progression of PCa in vitro. Mechanistically, circTENM3 enhanced RUNX3 levels via miR-558 sponge. Gain-of-function analysis determined that circTENM3 overexpression could inhibit PCa progression in vitro.

CONCLUSIONS

Our research offers profound insights into the protective role played by circTENM3 in PCa. CircTENM3 operates as a sponge for miR-558, thereby triggering the elevation of RUNX3 expression, which subsequently curbs the progression of PCa.

CircCDK1 blocking IGF2BP2-mediated m6A modification of CPPED1 promotes laryngeal squamous cell carcinoma metastasis via the PI3K/AKT signal pathway

BACKGROUND

Circular RNA (circRNA) is a novel noncoding RNA (ncRNA) that plays a critical role in various cancers. However, the clinical significance, biological function, and molecular mechanisms of circRNAs in laryngeal squamous cell carcinoma (LSCC) remain unclear.

METHODS

A circRNA array was performed to identify the differentially expressed circRNAs. In vitro and in vivo assays were proceeded to verify the biological function of circCDK1 in LSCC. RNA pulldown assays and RNA immunoprecipitation (RIP) were used to confirm the binding between circCDK1 and insulin-like growth factor 2 mRNA binding protein 2(IGF2BP2). The MeRIP assay was then used to identified the N6-methyladenisine (m6A) methylation of calcineurin like phosphatase domain containing1 (CPPED1).

RESULTS

Hsa_circ_0005774 (circCDK1) was found upregulated in LSCC tissues compared to adjacent normal tissues. The level of circCDK1 was positively correlated with poor prognosisof LSCC patients. In vitro and in vivo, circCDK1 promoted migration and invasion of LSCC cells. Mechanistically, eukaryotic translation initiation factor4A3(EIF4A3) induced biogenesis of circCDK1 by binding to its flanking. By competitively binding to IGF2BP2, circCDK1 blocked the m6A modification of CPPED1 in IGF2BP2-dependent manner. Moreover, the circCDK1-mediated decrease of CPPED1 activated the PI3K/AKT signal pathway to facilitate progression of LSCC.

CONCLUSIONS

Our findings demonstrated that EIF4A3-induced upregulation of circCDK1 promoted LSCC metastasis via EIF4A3-circCDK1-IGF2BP2-CPPED1 to activate PI3K-AKT signal pathway. CircCDK1 might serve as a new diagnostic and prognostic marker or potential therapeutic target for LSCC.

Glycolysis in human cancers: Emphasis circRNA/glycolysis axis and nanoparticles in glycolysis regulation in cancer therapy

The metabolism of cancer has been an interesting hallmark and metabolic reprogramming, especially the change from oxidative phosphorylation in mitochondria to glucose metabolism known as glycolysis occurs in cancer. The molecular profile of glycolysis, related molecular pathways and enzymes involved in this mechanism such as hexokinase have been fully understood. The glycolysis inhibition can significantly decrease tumorigenesis. On the other hand, circRNAs are new emerging non-coding RNA (ncRNA) molecules with potential biological functions and aberrant expression in cancer cells which have received high attention in recent years. CircRNAs have a unique covalently closed loop structure which makes them highly stable and reliable biomarkers in cancer. CircRNAs are regulators of molecular mechanisms including glycolysis. The enzymes involved in the glycolysis mechanism such as hexokinase are regulated by circRNAs to modulate tumor progression. Induction of glycolysis by circRNAs can significantly increase proliferation rate of cancer cells given access to energy and enhance metastasis. CircRNAs regulating glycolysis can influence drug resistance in cancers because of theirimpact on malignancy of tumor cells upon glycolysis induction. TRIM44, CDCA3, SKA2 and ROCK1 are among the downstream targets of circRNAs in regulating glycolysis in cancer. Additionally, microRNAs are key regulators of glycolysis mechanism in cancer cells and can affect related molecular pathways and enzymes. CircRNAs sponge miRNAs to regulate glycolysis as a main upstream mediator. Moreover, nanoparticles have been emerged as new tools in tumorigenesis suppression and in addition to drug and gene delivery, then mediate cancer immunotherapy and can be used for vaccine development. The nanoparticles can delivery circRNAs in cancer therapy and they are promising candidates in regulation of glycolysis, its suppression and inhibition of related pathways such as HIF-1α. The stimuli-responsive nanoparticles and ligand-functionalized ones have been developed for selective targeting of glycolysis and cancer cells, and mediating carcinogenesis inhibition.

CircXRN2 suppresses tumor progression driven by histone lactylation through activating the Hippo pathway in human bladder cancer

BACKGROUND

Bladder cancer (BCa) is the fourth most common malignant tumor with a poor prognosis worldwide. Further exploration and research are needed to unmask the underlying roles and molecular mechanisms of circular RNAs. In the current study, our findings showed that circXRN2 suppresses tumor progression driven by histone lactylation by activating the Hippo pathway in human bladder cancer.

METHODS

RNA immunoprecipitation (RIP) followed by circRNA sequencing confirmed circXRN2 as the research object. Overexpression of circXRN2 and knockdown of TAZ/YAP further verified the biological functions in T24 and TCCSUP cells. RIP, immunoprecipitation and coimmunoprecipitation were used to elucidate the interaction between circXRN2 and LATS1. A Seahorse metabolic analyzer was used to determine the glycolytic rate. Cleavage under targets and Tagmentation (CUT&Tag) and chromatin immunoprecipitation (ChIP) were employed to ensure the regulatory roles of H3K18 lactylation in the transcriptional activity of LCN2.

RESULTS

CircXRN2 is aberrantly downregulated in bladder cancer tissues and cell lines. CircXRN2 inhibits the proliferation and migration of tumor cells both in vitro and in vivo. In addition, circXRN2 serves as a negative regulator of glycolysis and lactate production. Mechanistically, circXRN2 prevents LATS1 from SPOP-mediated degradation by binding to the SPOP degron and then activates the Hippo signaling pathway to exert various biological functions. The circXRN2-Hippo pathway regulatory axis further modulates tumor progression by inhibiting H3K18 lactylation and LCN2 expression in human bladder cancer.

CONCLUSIONS

CircXRN2 suppresses tumor progression driven by H3K18 lactylation by activating the Hippo signaling pathway in human bladder cancer. Our results indicated novel therapeutic targets and provided promising strategies for clinical intervention in human bladder cancer.

CircUBXN7 promotes macrophage infiltration and renal fibrosis associated with the IGF2BP2-dependent SP1 mRNA stability in diabetic kidney disease

Introduction

Inflammatory cell infiltration is a novel hallmark of diabetic kidney disease (DKD), in part, by activated macrophages. Macrophage-to-tubular epithelial cell communication may play an important role in renal fibrosis. Circular RNAs (circRNAs) have been reported in the pathogenesis of various human diseases involving macrophages activation, including DKD. However, the exact mechanism of circRNAs in macrophage infiltration and renal fibrosis of DKD remains obscure.

Methods

In our study, a novel circRNA circUBXN7 was identified in DKD patients using microarray. The function of circUBXN7 in vitro and in vivo was investigated by qRT-PCR, western blot, and immunofluorescence. Finally, a dual-luciferase reporter assay, ChIP, RNA pull-down, RNA immunoprecipitation and rescue experiments were performed to investigate the mechanism of circUBXN7.

Results

We demonstrated that the expression of circUBXN7 was significantly upregulated in the plasma of DKD patients and correlated with renal function, which might serve as an independent biomarker for DKD patients. According to investigations, ectopic expression of circUBXN7 promoted macrophage activation, EMT and fibrosis in vitro, and increased macrophage infiltration, EMT, fibrosis and proteinuria in vivo. Mechanistically, circUBXN7 was transcriptionally upregulated by transcription factor SP1 and could reciprocally promote SP1 mRNA stability and activation via directly binding to the m6A-reader IGF2BP2 in DKD.

Conclusion

CircUBXN7 is highly expressed in DKD patients may provide the potential biomarker and therapeutic target for DKD.

Targeting PI3K/Akt signaling in prostate cancer therapy

Urological cancers have obtained much attention in recent years due to their mortality and morbidity. The most common and malignant tumor of urological cancers is prostate cancer that imposes high socioeconomic costs on public life and androgen-deprivation therapy, surgery, and combination of chemotherapy and radiotherapy are employed in its treatment. PI3K/Akt signaling is an oncogenic pathway responsible for migration, proliferation and drug resistance in various cancers. In the present review, the role of PI3K/Akt signaling in prostate cancer progression is highlighted. The activation of PI3K/Akt signaling occurs in prostate cancer, while PTEN as inhibitor of PI3K/Akt shows down-regulation. Stimulation of PI3K/Akt signaling promotes survival of prostate tumor cells and prevents apoptosis. The cell cycle progression and proliferation rate of prostate tumor cells increase by PI3K/Akt signaling induction. PI3K/Akt signaling stimulates EMT and enhances metastasis of prostate tumor cells. Silencing PI3K/Akt signaling impairs growth and metastasis of prostate tumor cells. Activation of PI3K/Akt signaling mediates drug resistance and reduces radio-sensitivity of prostate tumor cells. Anti-tumor compounds suppress PI3K/Akt signaling in impairing prostate tumor progression. Furthermore, upstream regulators such as miRNAs, lncRNAs and circRNAs regulate PI3K/Akt signaling and it has clinical implications for prostate cancer patients.

Cuproptosis-related miRNAs signature and immune infiltration characteristics in colorectal cancer

BACKGROUND

A novel form of cell death termed cuproptosis was proposed recently. miRNAs play important roles in colorectal cancer (CRC). However, their relationships have not been reported.

METHODS

miRNAs that negatively regulate 16 cuproptosis regulators were predicted using Targetscan database. The univariate Cox, LASSO, and multivariate Cox regression analyses were performed to select cuproptosis-related miRNAs. GSEA and ssGSEA analysis was carried out for functional enrichment analysis. The immune cell proportion score (IPS) and the efficiencies of multiple chemotherapy drugs were compared between different risk groups. The CCK8, cell colony, edu, and flow cytometry assays were performed to validate the roles of miRNA. Luciferase reporter assay confirmed the regulatory mechanism of miRNA on cuproptosis.

RESULTS

Six cuproptosis-related miRNAs (hsa-miR-653, hsa-miR-216a, hsa-miR-3684, hsa-miR-4437, hsa-miR-641, and hsa-miR-552) were screened out for model construction. The risk score could act as an independent prognostic indicator in CRC (p < 0.001, 95% HR = 1.243 (1.129-1.369)). The nomogram could efficiently predict the overall survival rate (AUC = 0.836). Then, the level of immunosuppressive pathways, immunosuppressive cells, stromal-activated genes, and stromal score was higher in the high-risk group. The IPS analysis showed a better response to immunotherapy in the low-risk group. Also, the risk score was closely correlated with efficiencies of multiple chemotherapy drugs. Furthermore, miR-653 was highly expressed in CRC tissues (p < 0.001), closely correlated with T stage (p < 0.001), metastasis (p < 0.001), and tumor stage (p < 0.001). High expression of miR-653 predicted a shorter overall survival (p = 0.0282) and disease-free survival (p = 0.0056). In addition, miR-653 promoted cell proliferation, inhibited apoptosis, and negatively regulated the expression of DLD through directly binding to the 3'-UTR of DLD mRNA.

CONCLUSION

We constructed a cuproptosis-related miRNA signature for the prediction of CRC patient survival and immunotherapy sensitivity. miR-653 was highly expressed in CRC tissues, promoted cell proliferation, and inhibited apoptosis by negatively regulating the expression of DLD.

Cancer-associated fibroblasts facilitate breast cancer progression through exosomal circTBPL1-mediated intercellular communication

Breast cancer is the major common malignancy worldwide among women. Previous studies reported that cancer-associated fibroblasts (CAFs) showed pivotal roles in regulating tumor progression via exosome-mediated cellular communication. However, the detailed mechanism underlying the exosomal circRNA from CAFs in breast cancer progression remains ambiguous. Here, exosomal circRNA profiling of breast cancer-derived CAFs and normal fibroblasts (NFs) was detected by high-throughput sequencing, and upregulated circTBPL1 expression was identified in CAF exosomes. The exosomal circTBPL1 from CAFs could be transferred to breast cancer cells and promoted cell proliferation, migration, and invasion. Consistently, circTBPL1 knockdown in CAFs attenuated their tumor-promoting ability. Further exploration identified miR-653-5p as an inhibitory target of circTBPL1, and ectopic expression of miR-653-5p could partially reverse the malignant phenotypes induced by circTBPL1 overexpression in breast cancer. Additionally, TPBG was selected as a downstream target gene, and circTBPL1 could protect TPBG from miR-653-5p-mediated degradation, leading to enhanced breast cancer progression. Significantly, the accelerated tumor progression triggered by exosomal circTBPL1 from CAFs was confirmed in xenograft models. Taken together, these results revealed that exosomal circTBPL1 derived from CAFs contributed to cancer progression via miR-653-5p/TPBG pathway, indicating the potential of exosomal circTBPL1 as a biomarker and novel therapeutic target for breast cancer.

CircNFATC3 promotes the proliferation of gastric cancer through binding to IGF2BP3 and restricting its ubiquitination to enhance CCND1 mRNA stability

BACKGROUND

Insulin like growth factor II mRNA binding protein 3 (IGF2BP3) is an RNA binding protein with multiple roles in regulation of gene expression at the post-transcriptional level and is implicated in tumorigenesis and progression of numerous cancers including gastric cancer (GC). Circular RNAs (circRNAs) are a diverse endogenous noncoding RNA population that have important regulatory roles in cancer. However, circRNAs that regulate the expression of IGF2BP3 in GC is largely unknown.

METHODS

CircRNAs that bound to IGF2BP3 were screened in GC cells using RNA immunoprecipitation and sequencing (RIP-seq). The identification and localization of circular nuclear factor of activated T cells 3 (circNFATC3) were identified using Sanger sequencing, RNase R assays, qRT-PCR, nuclear-cytoplasmic fractionation and RNA-FISH assays. CircNFATC3 expression in human GC tissues and adjacent normal tissues were measured by qRT-PCR and ISH. The biological role of circNFATC3 in GC was confirmed by in vivo and in vitro experiments. Furthermore, RIP, RNA-FISH/IF, IP and rescue experiments were performed to uncover interactions between circNFATC3, IGF2BP3 and cyclin D1 (CCND1).

RESULTS

We identified a GC-associated circRNA, circNFATC3, that interacted with IGF2BP3. CircNFATC3 was significantly overexpressed in GC tissues and was positively associated with tumor volume. Functionally, the proliferation of GC cells decreased significantly after circNFATC3 knockdown in vivo and in vitro. Mechanistically, circNFATC3 bound to IGF2BP3 in the cytoplasm, which enhanced the stability of IGF2BP3 by preventing ubiquitin E3 ligase TRIM25-mediated ubiquitination, thereby enhancing the regulatory axis of IGF2BP3-CCND1 and promoting CCND1 mRNA stability.

CONCLUSIONS

Our findings demonstrate that circNFATC3 promotes GC proliferation by stabilizing IGF2BP3 protein to enhance CCND1 mRNA stability. Therefore, circNFATC3 is a potential novel target for the treatment of GC.

Harnessing function of EMT in hepatocellular carcinoma: From biological view to nanotechnological standpoint

Management of cancer metastasis has been associated with remarkable reduction in progression of cancer cells and improving survival rate of patients. Since 90% of mortality are due to cancer metastasis, its suppression can improve ability in cancer fighting. The EMT has been an underlying cause in increasing cancer migration and it is followed by mesenchymal transformation of epithelial cells. HCC is the predominant kind of liver tumor threatening life of many people around the world with poor prognosis. Increasing patient prognosis can be obtained via inhibiting tumor metastasis. HCC metastasis modulation by EMT and HCC therapy by nanoparticles are discussed here. First of all, EMT happens during progression and advanced stages of HCC and therefore, its inhibition can reduce tumor malignancy. Moreover, anti-cancer compounds including all-trans retinoic acid and plumbaging, among others, have been considered as inhibitors of EMT. The EMT association with chemoresistance has been evaluated. Moreover, ZEB1/2, TGF-β, Snail and Twist are EMT modulators in HCC and enhancing cancer invasion. Therefore, EMT mechanism and related molecular mechanisms in HCC are evaluated. The treatment of HCC has not been only emphasized on targeting molecular pathways with pharmacological compounds and since drugs have low bioavailability, their targeted delivery by nanoparticles promotes HCC elimination. Moreover, nanoparticle-mediated phototherapy impairs tumorigenesis in HCC by triggering cell death. Metastasis of HCC and even EMT mechanism can be suppressed by cargo-loaded nanoparticles.

Oncofetal protein IGF2BPs in human cancer: functions, mechanisms and therapeutic potential

N⁶-methyladenosine (m⁶A) is the most prevalent and well-characterized internal chemical modification in eukaryotic RNA, influencing gene expression and phenotypic changes by controlling RNA fate. Insulin-like growth factor-2 mRNA-binding proteins (IGF2BPs) preferentially function as m⁶A effector proteins, promoting stability and translation of m⁶A-modified RNAs. IGF2BPs, particularly IGF2BP1 and IGF2BP3, are widely recognized as oncofetal proteins predominantly expressed in cancer rather than normal tissues, playing a critical role in tumor initiation and progression. Consequently, IGF2BPs hold potential for clinical applications and serve as a good choice for targeted treatment strategies. In this review, we discuss the functions and mechanisms of IGF2BPs as m⁶A readers and explore the therapeutic potential of targeting IGF2BPs in human cancer.

Targeting IGF2BP3 in Cancer

RNA-binding proteins (RBPs) can regulate multiple pathways by binding to RNAs, playing a variety of functions, such as localization, stability, and immunity. In recent years, with the development of technology, researchers have discovered that RBPs play a key role in the N6-methyladenosine (m6A) modification process. M6A methylation is the most abundant form of RNA modification in eukaryotes, which is defined as methylation on the sixth N atom of adenine in RNA. Insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3) is one of the components of m6A binding proteins, which plays an important role in decoding m6A marks and performing various biological functions. IGF2BP3 is abnormally expressed in many human cancers, often associated with poor prognosis. Here, we summarize the physiological role of IGF2BP3 in organisms and describe its role and mechanism in tumors. These data suggest that IGF2BP3 may be a valuable therapeutic target and prognostic marker in the future.

The emerging roles and mechanism of N6-methyladenosine (m6A) modifications in urologic tumours progression

Prostate cancer (PCa), bladder cancer (BC), and renal cell cancer (RCC) are the most common urologic tumours in males. N6-methyladenosine (m⁶A), adenosine N6 methylation, is the most prevalent RNA modification in mammals. Increasing evidence suggests that m⁶A plays a crucial role in cancer development. In this review, we comprehensively analyzed the influence of m⁶A methylation on Prostate cancer, bladder cancer, and renal cell cancer and the relationship between the expression of relevant regulatory factors and their development and occurrence, which provides new insights and approaches for the early clinical diagnosis and targeted therapy of urologic malignancies.

Advances in lung adenocarcinoma: A novel perspective on prognoses and immune responses of CENPO as an oncogenic superenhancer

Lung adenocarcinoma (LUAD) is the most prevalent form of lung cancer globally, and its treatment remains a significant challenge. Therefore, it is crucial to comprehend the microenvironment to improve therapy and prognosis urgently. In this study, we utilized bioinformatic methods to analyze the transcription expression profile of patient samples with complete clinical information from the TCGA-LUAD datasets. To validate our findings, we also analyzed the Gene Expression Omnibus (GEO) datasets. The super-enhancer (SE) was visualized using the peaks of the H3K27ac and H3K4me1 ChIP-seq signal, which were identified by the Integrative Genomics Viewer (IGV). To further investigate the role of Centromere protein O (CENPO) in LUAD, we conducted various assays including Western blot, qRT-PCR, flow cytometry, wound healing and transwell assays to assess the cell functions of CENPO in vitro. The overexpression of CENPO is linked to a poor prognosis in patients with LUAD. Strong signal peaks of H3K27ac and H3K4me1 were also observed near the predicted SE regions of CENPO. CENPO was found to be positively associated with the expression levels of immune checkpoints and drug IC50 value (Roscovitine and TGX221), but negatively associated with the fraction levels of several immature cells and drug IC50 value (CCT018159, GSK1904529A, Lenaildomide, and PD-173074). Additionally, CENPO-associated prognostic signature (CPS) was identified as an independent risk factor. The high-risk group for LUAD is identified based on CPS enrichment, which involved not only endocytosis that transfers mitochondria to promote cell survival in response to chemotherapy but also cell cycle promotion that leads to drug resistance. The removal of CENPO significantly suppressed metastasis and induced arrest and apoptosis of LUAD cells. The involvement of CENPO in the immunosuppression of LUAD provides a prognostic signature for LUAD patients.

Non-coding RNA-based therapeutics in cancer therapy: An emphasis on Wnt/β-catenin control

Non-coding RNA transcripts are RNA molecules that have mainly regulatory functions and they do not encode proteins. microRNAs (miRNAs), lncRNAs and circRNAs are major types of this family and these epigenetic factors participate in disease pathogenesis, especially cancer that their abnormal expression may lead to cancer progression. miRNAs and lncRNAs possess a linear structure, whereas circRNAs possess ring structures and high stability. Wnt/β-catenin is an important factor in cancer with oncogenic function and it can increase growth, invasion and therapy resistance in tumors. Wnt upregulation occurs upon transfer of β-catenin to nucleus. Interaction of ncRNAs with Wnt/β-catenin signaling can determine tumorigenesis. Wnt upregulation is observed in cancers and miRNAs are able to bind to 3'-UTR of Wnt to reduce its level. LncRNAs can directly/indirectly regulate Wnt and in indirect manner, lncRNAs sponge miRNAs. CircRNAs are new emerging regulators of Wnt and by its stimulation, they increase tumor progression. CircRNA/miRNA axis can affect Wnt and carcinogenesis. Overall, interaction of ncRNAs with Wnt can determine proliferation rate, migration ability and therapy response of cancers. Furthermore, ncRNA/Wnt/β-catenin axis can be utilized as biomarker in cancer and for prognostic applications in patients.