Expression Profile of Circular RNAs in Oral Squamous Cell Carcinoma.

Circular RNAs (circRNAs) are involved in the pathogenesis of several diseases. Among oral maxillofacial cancers, oral squamous cell carcinoma (OSCC) has the highest incidence. However, the role of circRNAs in OSCC is still not clear. The aim of our study was to evaluate the circRNA expression profile in OSCC and explore further the potential role of circRNAs in the pathogenesis of OSCC. CircRNA sequencing was performed in 6 pairs of samples of OSCC and normal oral mucosal tissues. Expression of selected circRNAs was validated by qRT-PCR. GO and KEGG analyses were performed and binding relationships between circRNAs and miRNAs were predicted. The hsa_circ_0001766/miR-877-3p/VEGFA axis was selected to further elucidate its role in OSCC. We showed that there were 122 differentially expressed (DE) circRNAs. Eight out of 10 selected circRNAs were validated by qRT-PCR. GO and KEGG analyses indicated that the identified DE circRNAs might be involved in the progression of OSCC. Then, after identification by Sanger sequencing and RNase R assay, the upregulated hsa_circ_0001766 was selected to investigate its potential role in OSCC. Bioinformatics analysis showed that hsa_circ_0001766 might act as a competing endogenous RNA (ceRNA) that sponged miR-877-3p to upregulate VEGFA expression. We selected OSCC cell lines SCC9 and SCC25. PCR results showed that the expression of hsa_circ_0001766 and VEGFA was upregulated in SCC9 and SCC25. Subsequently, using western blot, PCR, CCK8, and colony formation assays, we found that knocking down circRNA0001766 inhibited the expression of VEGFA and the proliferation of OSCC cells. Following this, miR-877-3p inhibitor reversed the inhibitory effect of si-hsa_circ_0001766 on expression of VEGFA and proliferation of OSCC cells. In conclusion, our study revealed the possible role of circRNAs in the pathogenesis of OSCC, and identified the potential role of the hsa_circ_0001766/miR-877-3p/VEGFA axis in OSCC progression.

Shao Y ，Song Y ，Xu S ，Li S ，Zhou H ... -  《Frontiers in Oncology》

Hsa_circ_0060927 Is a Novel Tumor Biomarker by Sponging miR-195-5p in the Malignant Transformation of OLK to OSCC.

To investigate the clinical significance of differentially expressed circRNAs and candidate circRNAs in the transformation of oral leukoplakia (OLK) to oral squamous cell carcinoma (OSCC). We performed high-throughput circRNA sequencing in six cases of normal oral mucosal (NOM) tissues, six cases of OLK tissues, and six cases of OSCC tissues. Ten circRNAs with significant differential expression were verified by qRT-PCR. Enzyme tolerance assay and Sanger sequencing were performed on the screened target circRNA hsa_circ_0060927, and a qRT-PCR assay of hsa_circ_0060927 was performed in three tissues (24 cases in each group); this was followed by an ROC analysis. The ceRNA network was predicted using TargetScan and miRanda. MiR-195-5p and TRIM14 were selected as the downstream research objects of hsa_circ_0060927. The sponge mechanism of hsa_circ_0060927 was detected by AGO2 RIP. The interaction between hsa_circ_0060927 and miR-195-5p was verified by RNA pull-down assay and dual luciferase reporter gene assay. The expressions of hsa_circ_0060927, miR-195-5p, and TRIM14 were verified by normal oral epithelial primary cells and cell lines of LEUK1, SCC9, and SCC25. The hsa_circ_0060927 overexpressed plasmid and miR-195-5p mimics were constructed to transfection LEUK1 to detect the changes in cell proliferation, apoptosis, and migration. The results of qRT-PCR validation were consistent with the sequencing results. Hsa_circ_0060927 is a true circRNA with trans-splicing sites. The expression of hsa_circ_0060927 increased in NOM, OLK, and OSCC. Overexpression of hsa_circ_0060927 enhanced the ability of cell proliferation and migration, and decreased cell apoptosis capacity. The prediction of ceRNA network suggested that hsa_circ_0060927 could regulate the target gene TRIM14 through sponging miR-195-5p. AGO2 RIP indicated that hsa_circ_0060927 had a sponge mechanism. RNA pull-down and dual luciferase reporter gene assay suggested that hsa_circ_0060927 interacted with miR-195-5p. Hsa_circ_0060927 was positively correlated with the expression of TRIM14, and could relieve the inhibition of miR-195-5p on TRIM14 to regulate cell proliferation, apoptosis, and migration of LEUK1 cells. Hsa_circ_0060927 acted as a potential key ceRNA to sponge downstream miR-195-5p and promote OLK carcinogenesis by upregulating TRIM14. Hsa_circ_0060927 was expected to be a molecular marker for the prevention and treatment of OLK carcinogenesis through the hsa_circ_0060927/miR-195-5p/TRIM14 axis.

Xu S ，Song Y ，Shao Y ，Zhou H ... -  《Frontiers in Oncology》

Hsa_circ_0008309 May Be a Potential Biomarker for Oral Squamous Cell Carcinoma.

Li B ，Wang F ，Li X ，Sun S ，Shen Y ，Yang H ... -  《-》

Expression profile and bioinformatics analysis of circular RNAs in acute ischemic stroke in a South Chinese Han population.

Li S ，Chen L ，Xu C ，Qu X ，Qin Z ，Gao J ，Li J ，Liu J ... -  《Scientific Reports》

Decreased expression of hsa_circ_0072387 as a valuable predictor for oral squamous cell carcinoma.

Increasing evidence points toward the key function of circular RNAs (circRNAs) in various carcinomas. This study aimed to identify aberrant expression of hsa_circ_0072387 in oral squamous cell carcinoma and probe its clinical significance. Real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was used to assess hsa_circ_0072387 expression levels in 63 paired OSCC tissues and three OSCC cell lines. The area under the receiver operator characteristic (ROC) curve was plotted to assess any potential clinical significance. Our data showed that hsa_circ_0072387 expression in OSCC was significantly downregulated compared with adjacent normal tissues (p < 0.001). Compared to human normal oral keratinocyte cell, the levels of hsa_circ_0072387 were lower in three OSCC cell lines (SCC25, SCC15, CAL27). More significantly, hsa_circ_0072387 expression was associated with the TNM stage in OSCC (p = 0.050). The area under the ROC curve reached up to 0.746. Based on bioinformatics, hsa-miR-129-3p, hsa-miR-141-3p, and hsa-miR-29-3p were predicted to be potential miRNAs binding with hsa_circ_0072387. Furthermore, hsa-miR-129-3p, hsa-miR-141-3p, and hsa-miR-29-3p were involved in multiple tumor-related signaling pathways. Our finding suggested that lower expression of has_circ_0072387 could be a key circRNA in OSCC and serve as a potential biomarker in OSCC diagnosis and therapeutic targets.

Dou Z ，Li S ，Ren W ，Wang Q ，Liu J ，Kong X ，Gao L ，Zhi K ... -  《-》