Circular RNA_0001742 has potential to predict advanced tumor stage and poor survival profiles in tongue squamous cell carcinoma management

Identification of circular RNA_0000919 as a potential diagnostic and prognostic biomarker of tongue squamous cell carcinoma using circular RNA microarray and reverse transcription‑quantitative PCR analyses

The present study aimed to identify differentially expressed (DE) circular RNAs (circRNAs/circs) using microarray analysis and to further explore the clinical significance of 10 candidate DEcircRNAs in patients with tongue squamous cell carcinoma (TSCC). A total of 60 patients with TSCC who underwent surgery were enrolled and five pairs of TSCC and adjacent (Ctrl) tissues were used for circRNA microarray analysis. Subsequently, the top five upregulated and downregulated DEcircRNAs were detected by reverse transcription-quantitative PCR (RT-qPCR) analysis in 60 pairs of tumor and Ctrl tissues, and their association with tumor features and overall survival (OS) was further analyzed. circRNA expression was used to differentiate TSCC from Ctrl tissues by principal component and heatmap analyses. A total of 134 upregulated and 67 downregulated DEcircRNAs were identified in TSCC tissues compared with Ctrl tissues. The DEcircRNAs were enriched in oncogenic signaling, including the ‘Wnt signaling pathway’ and the ‘MAPK signaling pathway’. The majority of DEcircRNAs exhibited several target microRNAs (miRNAs) in regulatory network analysis. These findings were validated by RT-qPCR analysis and the results demonstrated that the expression levels of 9/10 selected candidate DEcircRNAs (circ_0020048, circ_0000919, circ_0004525, circ_0002113, circ_0004029, circ_0004503, circ_0008752, circ_0002300 and circ_0001811) were dysregulated in TSCC tissues compared with Ctrl tissues. The expression levels of five DEcircRNAs (circ_0004503, circ_0008752, circ_0002300, circ_0020048 and circ_0000919) were associated with pathological grade or tumor clinical stage. Notably, only the expression levels of one DEcircRNA (circ_0000919) were associated with decreased OS. In conclusion, the present study indicated aberrant circRNA expression and potential circRNA-miRNA interactions in TSCC and identified circ_0000919 as a diagnostic and prognostic biomarker for TSCC management.

Diagnostic and prognostic value of circRNAs expression in head and neck squamous cell carcinoma: A meta-analysis

Background

Circular RNAs (circRNAs) have been found to have potential biological applications against tumors in humans. This study aimed to evaluate the diagnostic, prognostic, and clinicopathological value of circRNAs in head and neck squamous cell carcinoma (HNSCC).

Methods

The PubMed, Web of Science, EMBASE, and the Cochrane Library were comprehensively searched for the relevant studies before October 20, 2021. Statistical analysis was performed based on STATA 15.0, Meta‐DiSc 1.4, and RevMan 5.3 software.

Results

A total of 55 reports regarding 56 kinds of circRNA were studied in this meta‐analysis, including 23, 38, and 26 articles on diagnosis, prognosis, and clinicopathological features, respectively. The pooled sensitivity, specificity, and area under the curve (AUC) of the summary receiver‐operating characteristic curve (SROC) were 0.78, 0.84, and 0.87, respectively. Besides, the upregulation of oncogenic circRNAs was significantly associated with poorer overall survival (OS) (HR=2.25, p < 0.05) and disease‐free interval (DFS) (HR=1.92, p < 0.05). In contrast, the elevated expression of tumor suppressor circRNAs was associated with a favorable prognosis (HR=0.50, p < 0.05). In addition, the high expression of oncogenic circRNAs was associated with the tumor size (OR=3.59, p < 0.05), degree of differentiation (OR=1.89, p < 0.05), TNM stage (OR=2.35, p < 0.05), lymph node metastasis (OR=1.85, p < 0.05), and distant metastasis (OR=3.42, p < 0.05). Moreover, the expression of tumor suppressor circRNAs was associated with improved clinicopathological features (lymph node metastasis: OR=0.25, p < 0.05).

Conclusions

CircRNAs could serve as potential predictive indicators and be useful for the diagnosis, prognosis, and identification of clinicopathological features in HNSCC.

Prognostic Significance of CircRNAs Expression in Oral Squamous Cell Carcinoma

OBJECTIVE

This systematic review was aimed to comprehensively evaluate the clinicopathological and prognostic value of dysregulated expression of circRNAs in OSCC.

MATERIALS AND METHODS

The research was carried out by searching mainstream electronic databases including PubMed, Embase, Web of Science, Scopus, LILACS and Cochrane Library to collect relevant studies on prognostic role of circRNAs in OSCC. Pooled hazard ratios (HRs) and odds ratios(ORs) with 95% confidence intervals(CIs) were calculated to assess the association between circRNAs expression, overall survival(OS), disease/recurrence/progression survival(DFS/RFS/PFS) and clinical parameters.

RESULTS

This research included 1813 patients from 26 selected articles. The pooled HR values(95% CIs) in OS were 2.38(1.92-2.93) for oncogenic circRNAs and 0.43(0.28-0.66) for tumor-suppressor circRNAs respectively, in DFS/RFS/PFS were 2.34(1.73-3.17). The meta-analysis on clinicopathology features showed higher level of oncogenic circRNAs is related to advanced TNM stage and tumor stage, worse histological differentiation, lymph node and distant metastasis, while enforced expression of tumor-suppressor circRNAs is related to inferior TNM stage tumor stage and lymphatic metastasis.

CONCLUSION

Our meta-analysis implies that circRNAs may be candidate biomarkers for the prognosis and clinicopathology of OSCC.

Diagnostic Value of CircRNAs as Potential Biomarkers in Oral Squamous Cell Carcinoma: a Meta-Analysis

Introduction

Circular RNAs (CircRNAs), an emerging non-coding RNA, have been demonstrated to be involved in tumorigenesis, metastasis, and cancer progression, and could represent novel potential biomarkers for diagnosing oral squamous cell carcinoma (OSCC). However, no meta-analysis has investigated the diagnostic role of circRNAs in OSCC. Hence, to investigate whether circRNAs could serve as specific biomarkers for OSCC, the present systematic review and meta-analysis evaluated the diagnostic efficiency of circRNAs in patients with OSCC.

Materials and Methods

A thorough search of online databases (Pubmed, Web of Science, Embase, and the Cochrane Library) was conducted to collect relevant studies up to March 30th, 2021. All eligible studies were case-control studies. The quality of each study was evaluated by the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. STATA (version 15.1) and Review Manager (version 5.4) were employed to conduct the meta-analysis, and the PRISMA statement was adopted in this study.

Results

A total of 16 studies were included in the meta-analysis, with five studies on upregulated circRNAs, and 11 on downregulated circRNAs. The enrolled studies that met our eligibility criteria all derived from China. The pooled sensitivity (SEN), specificity (SPE), diagnostic odds ratio (DOR), positive likelihood ratio (PLR), negative likelihood ratio (NLR), and the area under receiver operating characteristics curve (AUC) with the 95% confidence intervals (95% CIs) were 0.74 (0.69–0.79), 0.79 (0.73–0.84), 10.74 (7.81–14.77), 3.50 (2.78–4.45), 0.33 (0.27–0.39) and 0.83 (0.79–0.86), respectively. The subgroup analysis demonstrated that serum, plasma, and saliva specimens had a better diagnostic performance than tissue samples, with a high value of sensitivity, specificity, DOR, and AUC values. The results also showed that the subgroups of upregulated circRNAs and a sample size of ≥100 manifested higher specificity, DOR, and AUC for cancer detection than downregulated circRNAs and a sample size of < 100.

Conclusions

A strong association was demonstrated between the dysregulated expression of circRNAs and the diagnosis of OSCC. Hence, circRNAs have the potential to function as promising biomarkers and therapeutic targets for OSCC.

Systematic Review Registration

PROSPERO, number CRD42021256857.

The Role of circRNAs in Human Papillomavirus (HPV)-Associated Cancers

Circular RNAs (circRNAs) are a new class of "non-coding RNAs" that originate from non-sequential back-splicing of exons and/or introns of precursor messenger RNAs (pre-mRNAs). These molecules are generally produced at low levels in a cell-type-specific manner in mammalian tissues, but due to their circular conformation they are unaffected by the cell mRNA decay machinery. circRNAs can sponge multiple microRNAs or RNA-binding proteins and play a crucial role in the regulation of gene expression and protein translation. Many circRNAs have been shown to be aberrantly expressed in several cancer types, and to sustain specific oncogenic processes. Particularly, in virus-associated malignancies such as human papillomavirus (HPV)-associated anogenital carcinoma and oropharyngeal and oral cancers, circRNAs have been shown to be involved in tumorigenesis and cancer progression, as well as in drug resistance, and some are useful diagnostic and prognostic markers. HPV-derived circRNAs, encompassing the HPV E7 oncogene, have been shown to be expressed and to serve as transcript for synthesis of the E7 oncoprotein, thus reinforcing the virus oncogenic activity in HPV-associated cancers. In this review, we summarize research advances in the biogenesis of cell and viral circRNAs, their features and functions in the pathophysiology of HPV-associated tumors, and their importance as diagnostic, prognostic, and therapeutic targets in anogenital and oropharyngeal and oral cancers.

Circ_0000003 regulates glutamine metabolism and tumor progression of tongue squamous cell carcinoma via the miR‑330‑3p/GLS axis

Various circular RNAs (circRNAs) have been shown to exert vital functions in tongue squamous cell carcinoma (TSCC). However, their roles in TSCC progression remain to be elucidated. This research aimed to investigate the role and mechanism of hsa_circ_0000003 (circ_0000003) in TSCC progression. Here, we found that circ_0000003 expression was upregulated in TSCC tissues and cell lines, and high circ_0000003 expression was correlated with advanced TNM stage, increased tumor size and poor patient survival. Circ_0000003 was revealed to facilitate cell proliferation, migration and invasion of TSCC cells. Mechanistically, we found that circ_0000003 acted as a competing endogenous RNA (ceRNA) that sponged miR‑330‑3p, thereby elevating glutaminase (GLS) expression. Accordingly, cell invasion, migration, glutamine consumption, α‑ketoglutarate (α‑KG) production and ATP production were significantly decreased by circ_0000003 knockdown in TSCC cells, and these effects were reversed by miR‑330‑3p inhibition. In conclusion, circ_0000003 facilitates TSCC cell proliferation, migration, invasion and glutamine catabolism by regulating the miR‑330‑3p/GLS pathway.

Hsa_circ_0043265 Restrains Cell Proliferation, Migration and Invasion of Tongue Squamous Cell Carcinoma via Targeting the miR-1243/SALL1 Axis

Increasing evidence has displayed critical roles of circular RNAs (circRNAs) in tongue squamous cell carcinoma (TSCC). Hsa_circ_0043265 (circ_0043265) has been identified as a tumor suppressor in various tumors. Nevertheless, the critical roles of circ_0043265 in the initiation and progression of TSCC are yet to be fully elucidated. In our study, RNA and protein expressions were detected via qRT-PCR and Western blot. Cell proliferation, migration and invasion were evaluated via CCK-8 and transwell assays. The interactions between circ_0043265, miR-1243 and SALL1 were analyzed via bioinformatics analyses, RNA pull-down and luciferase assays, respectively. The current study demonstrated that circ_0043265 expression was downmodulated in TSCC tissues and cell lines (SCC25, SCC15, SCC9 and Cal27). Functionally, circ_0043265 overexpression led to an attenuation of cell proliferation, migration and invasion of SCC25 and Cal27 cells. Mechanistically, circ_0043265 acted as a competing endogenous RNA (ceRNA) via competitively sponging miR-1243, and restoration of miR-1243 rescued the inhibitory effects of circ_0043265 on cell proliferation, migration and invasion of SCC25 and Cal27 cells. Finally, it was observed that spalt like transcription factor 1 (SALL1), a potential target of miR-1243, was positively modulated via circ_0043265 in SCC25 and Cal27 cells, and SALL1 knockdown reversed the inhibitory effects of circ_0043265 on SCC25 and Cal27 cells. Collectively, the current study demonstrated that circ_0043265 was downmodulated in TSCC and was identified as a ceRNA that restrained the cell proliferation, migration and invasion of SCC25 and Cal27 cells via modulating the miR-1243/SALL1 axis.

Circular RNA_0001742 has potential to predict advanced tumor stage and poor survival profiles in tongue squamous cell carcinoma management

Background

Circular RNA_0001742 (circ_0001742) has been reported to be upregulated in tongue squamous cell carcinoma (TSCC) tissues/cells and regulate TSCC cell proliferation, migration, and invasion. This study aimed to further investigate the clinical significance of circ_0001742 in TSCC management.

Methods

Totally, 146 TSCC patients underwent surgical treatment were reviewed. Their fresh‐frozen tumor tissue and adjacent tissue were acquired for detecting circ_0001742 expression via reverse transcription‐quantitative polymerase chain reaction. According to circ_0001742 expression in tumor tissue, all patients were classified as tumor circ_0001742 low (0%‐50% percentile) and high (50%‐100% percentile) patients, the latter were further divided into the tumor circ_0001742 high+ (50%‐75% percentile), high++ (75%‐90% percentile), and high+++ (90%‐100% percentile) patients, respectively.

Results

Circ_0001742 expression was increased in TSCC tumor tissue compared with adjacent tissue, and it presented good value in discriminating tumor tissue from adjacent tissue (area under the curve (AUC): 0.870, 95% CI: 0.831‐0.910). Tumor high circ_0001742 expression was associated with higher T stage, N stage, and TNM stage, but not age, gender, or pathological grade. Furthermore, OS was reduced in tumor circ_0001742 high patients compared with tumor circ_0001742 low patients; moreover, OS was the shortest in tumor circ_0001742 high+++ patients, followed by tumor circ_0001742 high++ patients and tumor circ_0001742 high+ patients, and the longest in tumor circ_0001742 low patients. In addition, multivariate Cox's regression analysis revealed that higher tumor circ_0001742 expression was an independent predictive factor for decreased OS.

Conclusion

Circ_0001742 serves as a potential biomarker for advanced tumor stage and poor survival in TSCC patients.