Dysregulated circular RNAs as novel biomarkers in esophageal squamous cell carcinoma: a meta-analysis

Expression of circRNA-0036474 in esophageal cancer and its clinical significance

Circular RNAs are considered to play important roles in the progression of different cancers such as esophageal squamous cell carcinoma. However, the functions of circular RNAs in esophageal squamous cell carcinoma are still not clear. This study aimed to investigate the role and mechanism of circRNA-0036474 in the progression of esophageal squamous cell carcinoma. The hsa_circ_0036474 expression levels were found to be elevated in both EC109 cells and esophageal squamous cell carcinoma tissue samples. Moreover, knockdown of circRNA-0036474 expression in the EC109 cells induced migration and invasion, characterized by the down-regulation of E-cadherin, and up-regulation of N-cadherin and vimentin. In addition, the over-expressed hsa_circ_0036474 significantly decreased the activity of EC109 cells, elevated E-cadherin expression but declined N-cadherin and vimentin expression. Moreover, over-expressed mir-223-3p levels and interfered RERG expression verified the role of hsa_circ_0036474 in inhibiting the invasion and migration of EC109 cells, reducing the expression of N-cadherin and vimentin, and promoting the expression of E-cadherin. In conclusion, circRNA-0036474 mitigated the progression of esophageal squamous cell carcinoma through regulating mir-223-3p/RERG axis, presenting a potential therapeutic target for the treatment.

Circ-ILF2 in oral squamous cell carcinoma promotes cisplatin resistance and induces M2 polarization of macrophages

Cisplatin (CDDP) chemoresistance is one of the predominant factors in oral squamous cell carcinoma (OSCC) treatment failure. Uncovering the mechanisms underlying CDDP resistance is of great importance in OSCC therapy. Circular RNAs (circRNAs) are a newly discovered class of noncoding RNAs, which are reported to participate in the progression of various diseases, including cancer. However, the function of circRNAs in CDDP resistance in OSCC remains unclear. Quantitative reverse transcription PCR was used to search for different circRNAs between OSCC cell lines and CDDP-resistant cell lines. The results showed that circ-ILF2 expression was higher in CDDP-resistant OSCC cell lines. The stability of circ-ILF2 was also confirmed using RNase R and actinomycin D assays. Functional experiments, including cytotoxicity, apoptosis and growth rate assays, showed that upregulation of circ-ILF2 contributes to CDDP resistance. Luciferase reporter-gene, RNA pull-down and quantitative real-time PCR (RT-qPCR) assays showed that circ-ILF2 functions as a microRNA sponge for miR-1252. Luciferase reporter assays, RNA pull-down, RT-qPCR and Western blotting showed that miR-1252 directly targeted and regulated the expression of KLF8. Circ-ILF2 plays an important role in CDDP resistance in OSCC. Circ-ILF2 exerts its function through the miR-1252/KLF8 pathway. In addition, tumour-associated macrophages (TAM) play important roles in cancer progressions, our results showed that circ-ILF2 in OSCC cells induced the M2 polarization of macrophages which provided new thoughts on immunotherapy. Our results suggest that circ-ILF2 may represent a potential therapeutic target in CDDP-resistant OSCC.

Hsa_circ_0043603 promotes the progression of esophageal squamous cell carcinoma by sponging miR-1178-3p and regulating AADAC expression

This study aims to investigate the regulatory impact of hsa_circ_0043,603, a circular RNA, on the progression of esophageal squamous cell carcinoma (ESCC), which ranks as the sixth leading cause of global mortality. We evaluated the expression, origin, and localization of hsa_circ_0043,603 in ESCC tumors using qRT-PCR, bioinformatics, and FISH analysis. Functional studies were conducted by manipulating the hsa_circ_0043,603 expression in Eca109 cells through overexpression and silencing plasmids. Additionally, xenografts derived from circ_0043,603-overexpressing Eca109 cells enabled us to investigate tumor growth, proliferation, and apoptosis. Through Starbase analysis, we identified miR-1178-3p as a target of circ_0043,603, which was validated using RIP and luciferase assays. Furthermore, we predicted arylacetamide deacetylase (AADAC) as a target of miR-1178-3p and examined its expression in ESCC tissues using Western blot. Lastly, we performed AADAC silencing and overexpression in Eca109 cells to study their impact on cellular phenotypic features, apoptosis, and their interaction with miR-1178-3p mimics and inhibitors. The low expression of hsa_circ_0043,603 in ESCC tissue was associated with poor prognosis. Overexpression of hsa_circ_0043,603 inhibited ESCC growth, invasion, migration, and proliferation, while promoting apoptosis in vitro and suppressing tumor growth in vivo. hsa_circ_0043,603 achieved these effects by targeting the oncogenic miR-1178-3p. Furthermore, AADAC was identified as a target of miR-1178-3p, and its reduced expression was confirmed in ESCC tissues. Overexpression of AADAC in Eca109 cells resulted in suppressed cell growth, proliferation, migration, and invasion by regulating miR-1178-3p. hsa_circ_0043,603 acts as a sponge for miR-1178-3p, leading to the regulation of AADAC expression and inhibition of ESCC development. These results suggest the potential of hsa_circ_0043,603 as a therapeutic and diagnostic target for ESCC.

Non-coding RNAs and gastrointestinal cancers prognosis: an umbrella review of systematic reviews and meta-analyses of observational studies

Aim

Provide an overview and a systematic evaluation of the evidence quality on the association between non-coding RNAs (ncRNAs) and prognosis value for gastrointestinal cancers (GICs).

Methods

We searched the literature from three electronic databases: Pubmed, Embase, and Web of science, then carefully screened and extracted the primary information and results from the included articles. We use A measurable systematic review and meta-analysis evaluation tool (AMSTAR2) to evaluate the quality of methodology and then use the Grading of Recommendations Assessment 2, Development and Evaluation guideline (GRADE) make sure the reliability of the meta-analysis.

Results

Overall, 182 meta-analyses from 58 studies were included in this study. Most of these studies are of low or very low quality. Using the scoring tool, we found that only two meta-analyses were rated as high reliability, and 17 meta-analyses were rated as medium reliability.

Conclusions

Although ncRNA has good prognostic value in some studies, only a tiny amount of evidence is highly credible at present. More research is needed in the future.

PROSPERO registration number

CRD42022382296.

The Important Role of m6A-Modified circRNAs in the Differentiation of Intramuscular Adipocytes in Goats Based on MeRIP Sequencing Analysis

Intramuscular fat contributes to the improvement of goat meat quality. N⁶-Methyladenosine (m6A)-modified circular RNAs play important roles in adipocyte differentiation and metabolism. However, the mechanisms by which m6A modifies circRNA before and after differentiation of goat intramuscular adipocytes remain poorly understood. Here, we performed methylated RNA immunoprecipitation sequencing (MeRIP-seq) and circRNA sequencing (circRNA-seq) to determine the distinctions in m6A-methylated circRNAs during goat adipocyte differentiation. The profile of m6A-circRNA showed a total of 427 m6A peaks within 403 circRNAs in the intramuscular preadipocytes group, and 428 peaks within 401 circRNAs in the mature adipocytes group. Compared with the intramuscular preadipocytes group, 75 peaks within 75 circRNAs were significantly different in the mature adipocytes group. Furthermore, the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses of intramuscular preadipocytes and mature adipocytes showed that the differentially m6A-modified circRNAs were enriched in the PKG signaling pathway, endocrine and other factor-regulated calcium reabsorption, lysine degradation, etc. m6A-circRNA-miRNA-mRNA interaction networks predicted the potential m6A-circRNA regulation mechanism in different goat adipocytes. Our results indicate that there is a complicated regulatory relationship between the 12 upregulated and 7 downregulated m6A-circRNAs through 14 and 11 miRNA mediated pathways, respectively. In addition, co-analysis revealed a positive association between m6A abundance and levels of circRNA expression, such as expression levels of circRNA_0873 and circRNA_1161, which showed that m6A may play a vital role in modulating circRNA expression during goat adipocyte differentiation. These results would provide novel information for elucidating the biological functions and regulatory characteristics of m6A-circRNAs in intramuscular adipocyte differentiation and could be helpful for further molecular breeding to improve meat quality in goats.

Prognostic, Diagnostic, and Clinicopathological Significance of Circular RNAs in Pancreatic Cancer: A Systematic Review and Meta-Analysis

Pancreatic cancer (PC) is a highly aggressive malignant tumor with a high mortality rate. It is urgent to find optimal molecular targets for the early diagnosis and treatment of PC. Here, we aimed to systematically analyze the prognostic, diagnostic, and clinicopathological significance of circular RNAs (circRNAs) in PC. Relevant studies were screened through PubMed, Web of Science, and other databases. The prognostic value of PC-associated circRNAs was assessed using the composite hazard ratio (HR), the diagnostic performance was assessed using the area under the summary receiver operator characteristic (SROC) curve (AUC), and the correlation with clinicopathological characteristics using the composite odds ratio (OR) was explored. In our study, 48 studies were included: 34 for prognosis, 11 for diagnosis, and 30 for correlation with clinicopathological characteristics. For prognosis, upregulated circRNAs were associated with poorer overall survival (OS) (HR = 2.02) and disease-free survival/progression-free survival (HR = 1.84) while downregulated circRNAs were associated with longer OS (HR = 0.55). Notably, the combination of circRNAs, including hsa_circ_0064288, hsa_circ_0000234, hsa_circ_0004680, hsa_circ_0071036, hsa_circ_0000677, and hsa_circ_0001460, was associated with worse OS (HR = 2.35). For diagnosis, the AUC was 0.83, and the pooled sensitivity and specificity were 0.79 and 0.73, respectively. For clinicopathologic characteristics, upregulated circRNAs were associated with poorer tumor differentiation, more nerve and vascular invasion, higher T stage, lymphatic metastasis, distant metastasis, advanced TNM stage, and higher preoperative CA19-9 level. In contrast, downregulated circRNAs were negatively associated with PC differentiation and lymphatic metastasis. Overall, our results showed that circRNAs are closely related to the prognosis and clinicopathological characteristics of PC patients and could be utilized for early diagnosis; thus, they are promising biomarkers for clinical application in PC.

Correlation Analysis of circRNA Circ_0071662 in Diagnosis and Prognosis of Esophageal Squamous Cell Carcinoma

Background

The role of circRNA circ_0071662 has been studied in bladder cancer. The present study aimed to analyze its involvement in esophageal squamous cell carcinoma (ESCC).

Methods

Patients with ESCC (n = 66), esophageal ulcer (EU, n = 66), or gastroesophageal reflux disease (GERD, n = 66) and healthy controls (n = 66) were enrolled in this study. Plasma samples were collected from all patients and controls. ESCC and paired non-tumor tissue samples were collected from ESCC patients. Circ_0071662 levels in these samples were determined by RT-qPCRs. Diagnostic and prognostic values of circ_0071662 for ESCC were analyzed with ROC curve and survival curve analyses.

Results

Circ_0071662 level was decreased in ESCC, but not in GERN and EU compared to the controls and in ESCC tissues compared to the non-tumor tissues. Plasma circ_0071662 was closely correlated with patients’ tumor size but not with other clinical features. Decreased plasma circ_0071662 levels separated ESCC patients from GERN patients, EU patients, and healthy controls. Low plasma circ_0071662 levels were closely correlated with worse survival outcomes of ESCC patients.

Conclusion

Circ_0071662 is lowly expressed in ESCC and may serve as a potential diagnostic and prognostic biomarker for ESCC.

MicroRNA-148a-3p suppresses cell proliferation and migration of esophageal carcinoma by targeting CEP55

This study evaluated microRNA-148a-3p in esophageal carcinoma cells. The prediction of bioinformatics analysis revealed that microRNA-148a-3p may target CEP55. qRT-PCR and western blot showed that CEP55 level in esophageal carcinoma cells and tissue was dramatically higher than that of normal cells and tissue, while microRNA-148a-3p was the opposite. Forced expression of microRNA-148a-3p restrained cell malignant behaviors of esophageal carcinoma, and repression of microRNA-148a-3p resulted in the converse results in terms of cell function. Dual-luciferase assay confirmed that microRNA-148a-3p targeted CEP55. CEP55 attenuated the suppressive effect of microRNA-148a-3p on proliferation and migration of esophageal carcinoma cells, demonstrating that microRNA-148a-3p regulated function of esophageal carcinoma cells via decreasing CEP55 level. Microscopy observation indicated that cell morphology was also affected by the microRNA-148a-3p/CEP55 axis. Furthermore, western blot analysis revealed that the PI3K/AKT signaling pathway could be suppressed by activating the microRNA-148a-3p/CEP55 axis. Finally, in vivo experiments confirmed the effects of microRNA-148a-3p on tumorigenesis. Thus, microRNA-148a-3p could act as a repressor in esophageal carcinoma via binding to CEP55.