Prognostic Role of Circular RNAs Expression in Bladder Carcinoma: A Meta-Analysis

Intelligent structure prediction and visualization analysis of non-coding RNA in osteosarcoma research

Background

Osteosarcoma (OS) is the most common bone malignant tumor in children and adolescents. Recent research indicates that non-coding RNAs (ncRNAs) have been associated with OS occurrence and development, with significant progress made in this field. However, there is no intelligent structure prediction and literature visualization analysis in this research field. From the perspective of intelligent knowledge structure construction and bibliometrics, this study will comprehensively review the role of countries, institutions, journals, authors, literature citation relationships and subject keywords in the field of ncRNAs in OS. Based on this analysis, we will systematically analyze the characteristics of the knowledge structure of ncRNAs in OS disease research and identify the current research hotspots and trends.

Methods

The Web of Science Core Collection (WoSCC) database was searched for articles on ncRNAs in OS between 2001 and 2023. This bibliometric analysis was performed using VOSviewers, CiteSpace, and Pajek.

Results

This study involved 15,631 authors from 2,631 institutions across 57 countries/regions, with a total of 3,642 papers published in 553 academic journals. China has the highest number of published papers in this research field. The main research institutions include Nanjing Medical University (n = 129, 3.54%), Shanghai Jiao Tong University (n = 128, 3.51%), Zhengzhou University (n = 110, 3.02%), and China Medical University (n = 109, 2.99%). Oncology Letters (n =139, 3.82%), European Review for Medical Pharmacological Sciences (120, 3.31%), and Molecular Medicine Reports (n = 95, 2.61%) are the most popular journals in this field, with Oncotarget being the most co-cited journal (Co-Citation = 4,268). Wei Wang, Wei Liu, and Zhenfeng Duan published the most papers, with Wang Y being the most co-cited author. "miRNA", "lncRNA" and "circRNA" are the main focuses of ncRNAs in OS studies. Key themes include "migration and invasion", "apoptosis and proliferation", "prognosis", "biomarkers" and "chemoresistance". Since 2020, hotspots and trends in ncRNA research in OS include "tumor microenvironment", "immune" and "exosome".

Conclusion

This study represents the first comprehensive bibliometric analysis of the knowledge structure and development of ncRNAs in OS. These findings highlight current research hotspots and frontier directions, offering valuable insights for future studies on the role of ncRNAs in OS.

m6A-modified circASXL1 promotes proliferation and migration of ovarian cancer through the miR-320d/RACGAP1 axis

Ovarian cancer (OC) is one of the most common malignant tumors in women. Circular RNAs (circRNAs) can potentially regulate the development of OC. Therefore, this study investigated the role of circASXL1 in OC progression. Cell functions were assessed by MTT, colony formation, wound healing, and transwell assays. RIP and dual luciferase reporter assays confirmed the relationship between miR-320d and circASXL1 or RACGAP1. MeRIP was utilized to detect m6A levels. Xenograft tumor was established for in vivo experiments. CircASXL1 and RACGAP1 levels were increased in OC tissues and cells, whereas miR-320d expression was decreased. Upregulation of circASXL1 was associated with poor prognosis in OC patients. CircASXL1 silencing suppressed OC cell proliferation, migration and invasion in vitro and in vivo. Mechanistically, METTL3/IGF2BP1-mediated m6A modification maintained circASXL1 stability and upregulated its expression. CircASXL1 was a ceRNA that sequestrated miR-320d from RACGAP1, leading to increased RACGAP1 expression. CircASXL1 promoted OC cell proliferation, migration and invasion via the miR-320d/RACGAP1 axis. Therefore, m6A-modified circASXL1 acts as an oncogene in OC by targeting miR-320d and activating RACGAP1/PI3K/Akt pathway, which provides novel promising biomarkers for OC diagnosis.

Protein-coding circular RNAs - mechanism, detection, and their role in cancer and neurodegenerative diseases

Circular RNAs (circRNAs) are a unique class of non-coding RNAs and were originally thought to have no protein-coding potential due to their lack of a 5' cap and 3' poly(A) tail. However, recent studies have challenged this notion and revealed that some circRNAs have protein-coding potential. They have emerged as a key area of interest in cancer and neurodegeneration research as recent studies have identified several circRNAs that can produce functional proteins with important roles in cancer progression. The protein-coding potential of circRNAs is determined by the presence of an open reading frame (ORF) within the circular structure that can encode a protein. In some cases, the ORF can be translated into a functional protein despite the lack of traditional mRNA features. While the protein-coding potential of most circRNAs remains unclear, several studies have identified specific circRNAs that can produce functional proteins. Understanding the protein-coding potential of circRNAs is important for unravelling their biological functions and potential roles in disease. Our review provides comprehensive coverage of recent advances in the field of circRNA protein-coding capacity and its impact on cancer and neurodegenerative diseases pathogenesis and progression.

Noncoding RNAs as a potential biomarker for the prognosis of bladder cancer: a systematic review and meta-analysis

OBJECTIVE

The relationship between noncoding RNAs and the prognosis of bladder cancer (BC) is still controversial. The purpose of this study is to evaluate the relationship between noncoding RNAs and prognosis by meta-analysis.

METHODS

Comprehensive retrieval of PubMed, Embase, the Cochrane Library, the Web of Science, CNKI, and WanFang databases is related to the correlation between noncoding RNAs and the prognosis of BC. Data were extracted, and the literature quality was evaluated. STATA16.0 served for the meta-analysis.

RESULTS

1. CircRNAs: High circ-ZFR expression led to poor overall survival (OS) of BC. 2. LncRNAs: Low lnc-GAS5 expression predicted poor OS of BC, high lnc-TUG1 expression predicted poor OS of BC. 3. MiRNAs: High miR-21 expression predicted poor OS of BC, high miR-222 expression led to poor OS of BC, high miR-155 expression predicted poor progression-free survival (PFS) of BC, high miR-143 expression caused poor PFS of BC, low miR-214 expression could result in poor recurrence-free survival (RFS) of BC.

CONCLUSIONS

High circ-ZFR, lnc-TUG1, miR-222, and miR-21 expressions were correlated with poor OS of BC; high miR-155 and miR-143 expression predicted poor PFS of BC; low lnc-GAS5 expression predicted poor OS of BC; low miR-214 expression predicted poor RFS of BC.

Recent progress in nanocarrier-based drug delivery systems for antitumour metastasis

Tumour metastasis is one of the major factors leading to poor prognosis as well as lower survival among cancer patients. A number of studies investigating the inhibition of tumour metastasis have been conducted. It is difficult to achieve satisfactory results with surgery alone for distant metastatic tumours, and chemotherapy can boost the healing rate and prognosis of patients. However, the poor therapeutic efficacy of chemotherapy drugs due to their low solubility, lack of tumour targeting, instability in vivo, high toxicity and multidrug resistance hinder their application. Immunotherapy is beneficial to the treatment of metastatic cancers, but it also has disadvantages such as adverse reactions and acquired resistance. Fortunately, delivery of chemotherapeutic drugs with nanocarriers can reduce systemic reactions caused by chemotherapeutic agents and inhibit metastasis. This review discusses the underlying mechanisms of metastasis, therapeutic approaches for antitumour metastasis, the advantages of nanodrug delivery systems and their application in reducing metastasis.

Circular RNA MYLK as a prognostic biomarker in patients with cancers: A systematic review and meta‐analysis

Background

Aims

Methods

Results

Conclusions

High Expression of Circular RNA-Mitochondrial tRNA Translation Optimization 1 Assists the Diagnosis of High-Risk Human Papillomavirus Infection in Cervical Cancer

OBJECTIVE

Persistence of high-risk human papillomavirus (HR-HPV) infection is a paramount determinant in cervical cancer (CC) development. Circular RNAs have the potential to be promising biomarkers for various cancers. This study explored circular RNA-mitochondrial tRNA translation optimization 1 (circMTO1) expression in the serum of CC patients and its clinical value in diagnosing CC and predicting HR-HPV infection.

MATERIALS AND METHODS

In total, 125 CC patients (including 78 cases with HR-HPV) were enrolled, with another 76 healthy people as controls. Serum circMTO1 and miR-199a expressions were detected by reverse transcription-quantitative polymerase chain reaction, and the diagnostic efficacy of circMTO1 for CC and HR-HPV infection was analyzed by the receiver operating characteristic curve. According to the median of serum circMTO1 expression, CC patients were assigned into circMTO1 low/high expression groups to analyze the correlation between circMTO1 and clinical parameters using the Fisher and χ 2 tests. Independent association of circMTO1 with HR-HPV infection in CC was evaluated via logistics multivariate regression analysis. Targeted relationship between miR-199a and circMTO1 was predicted by Starbase Web site and validated via dual-luciferase assay, with their correlation further assessed by Pearson analysis.

RESULTS

Serum circMTO1 was increased in CC patients and prominently elevated in HR-HPV-positive CC patients, with a level greater than 1.485 assisting CC diagnosis and a level greater than 2.480 assisting HR-HPV-positive diagnosis. The circMTO1 was interrelated to clinical stage, tumor differentiation, lymph node metastasis, invasion depth, and independently linked with HR-HPV infection in CC. Serum miR-199a was downregulated in HR-HPV-positive CC patients and inversely correlated with circMTO1.

CONCLUSIONS

Serum circMTO1 is upregulated in HR-HPV-positive CC patients and has a diagnostic value for HR-HPV infection in CC.

Circ_VANGL1 affects proliferation, migration, and invasion of colorectal cancer cells by regulating miR-493-5p/FXR1 axis

BACKGROUND

CircRNAs are abnormally expressed in colorectal cancer (CRC) tissues, cell lines, and plasma, and are closely related to the clinical malignant characteristics of CRC. However, the expression and functional mechanism of circ_VANGL1 in CRC are still unclear. We hypothesized that circ_VANGL1 affects the proliferation, migration, and invasion of CRC cells by regulating the miR-493-5p/fragile X-related gene 1 (FXR1) axis.

AIM

To investigate the effect of circ_VANGL1 on the prolife-ration, migration, and invasion of CRC cells and the possible mechanism involved.

METHODS

Western blot was used to detect the expression of FXR1 in CRC tissues and adjacent tissues. RT-qPCR was performed to detect the expression of circ_VANGL1 and miR-493-5p. CRC cells Caco-2 were cultured in vitro and divided into si-circ_VANGL1 group, si-NC group, miR-NC group, miR-493-5p mimic group, and si-circ_VANGL1 + miR-493-5p inhibitor group. CCK-8 and clone formation assays were performed to evaluate the proliferation ability of Caco-2 cells. Transwell assay was employed to evaluate the migration and invasion ability of Caco-2 cells. Dual luciferase reporter assay was used to detect the interaction between RNAs (circ_VANGL1 and miR-493-5p, miR-493-5p, and FXR1).

RESULTS

Compared with tumor adjacent tissues, the relative expression levels of circ_VANGL1 and FXR1 protein in CRC tissue were significantly increased (P < 0.05), but the relative level of miR-493-5p was significantly decreased (P < 0.05). Compared with the si-NC group, the inhibition rate of Caco-2 cells and the relative level of miR-493-5p in the si-circ_VANGL1 group were significantly increased (P < 0.05), but the expression of FXR1 protein, the number of colonies formed, and the migration and invasion ability were significantly reduced (P < 0.05). Compared with the miR-NC group, the inhibition rate of Caco-2 cells in the miR-493-5p mimic group was significantly increased (P < 0.05), but the expression of FXR1 protein, the number of colonies formed, and the migration and invasion ability were significantly reduced (P < 0.05). Circ_VANGL1 directly bound to miR-493-5p. Compared with the si-circ_VANGL1 group, the inhibition rate of Caco-2 cells in the si-circ_VANGL1 + miR-493-5p inhibitor group was significantly reduced (P < 0.05), but the expression of FXR1 protein, the number of colonies formed, and the migration and invasion ability were significantly increased (P < 0.05).

CONCLUSION

Silencing circ_VANGL1 inhibits the proliferation, migration, and invasion of CRC cells by regulating the miR-493-5p/FXR1 axis.

Cancer-associated fibroblast exosomes promote chemoresistance to cisplatin in hepatocellular carcinoma through circZFR targeting signal transducers and activators of transcription (STAT3)/ nuclear factor -kappa B (NF-κB) pathway

Chemoresistance in hepatocellular carcinoma (HCC) has been found to be influenced by exosomal transport of circRNAs. However, the role of circZFR in HCC chemoresistance still remains unclear. In the present study, circZFR was highly expressed in cisplatin (DDP)-resistant HCC cell lines and could regulate DDP resistance of the HCC cells. Also, circZFR was highly expressed in cancer-associated fibroblast (CAFs) and the exosome of CAFs. In addition, supplementation of CAFs in culture medium could promote DDP resistance of HCC cells. In vivo tumor xenograft experiments showed that knockdown of circZFR inhibited tumor growth and weakened DDP resistance, while CAFs-derived exosomes incubation increased the expression of circZFR, inhibited the STAT3/NF-κB pathway, promoted tumor growth, and enhanced DDP resistance. In general, CAFs-derived exosomes deliver circZFR to HCC cells, inhibit the STAT3/NF-κB pathway, and promote HCC development and chemoresistance. The results provided a new sight for the prevention and treatment of chemoresistance in HCC.

The Roles of circMTO1 in Cancer

Circular RNAs (circRNAs) are a recently discovered type of covalently-closed circular non-coding RNAs, mainly formed by non-sequential back-splicing of precursor mRNAs (pre-mRNAs). Recent studies have demonstrated that circRNAs can have either oncogenic or tumor-suppressor roles depending on the cellular context. CircRNA mitochondrial tRNA translation optimization 1 (circMTO1), a recently reported circular RNA originating from exons of MTO1 located on chromosome 6q13, was proved to be abnormally expressed in many malignant tumors, such as hepatocellular carcinoma, gastric carcinoma and colorectal cancer, resulting in tumor initiation and progression. However, there are no reviews focusing on the roles of circMTO1 in cancer. Here, we first summarize the main biological characteristics of circMTO1, and then focus on its biological functions and the possible underlying molecular mechanisms. Finally, we summarize the roles of circMTO1 in cancer and discuss future prospects in this area of research.