Effects of hsa_circ_0000711 expression level on proliferation and apoptosis of hepatoma cells

Analysis of circRNA profiles and clinical value in Stevens-Johnson syndrome and toxic epidermal necrolysis

Severe cutaneous adverse drug reactions, including Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), are challenging to be early diagnosed and evaluate their prognoses. This investigation aimed to analyse the expression profiles of SJS/TEN in peripheral blood mononuclear cells (PBMC) and assess the correlation between circular RNA (circRNA) and disease severity. Sixteen SJS/TEN patients and sixteen controls were enrolled and serum samples of both groups were obtained. CircRNA expression profiles in three SJS/TEN patients and three controls were detected by RNA sequencing and bioinformatic analyses were then performed. The differentially expressed circRNAs were verified by quantitative polymerase chain reaction (qPCR). Then, analysing the correlation of circRNAs with the toxic epidermal necrolysis-specific severity of illness score (SCORTEN) and the epidermal detachment area. A total of 134 circRNAs were differentially expressed in the PBMCs of SJS/TEN individuals, according to our results. The qPCR showed that three circRNAs (hsa_circ_0000711, hsa_circ_0083619 and hsa_circ_0005615) were down-regulated, and one circRNA (hsa_circ_0003028) was up-regulated, which were compatible with the sequencing findings. The concentration of hsa_circ_0083619 was closely associated with the SCORTEN scale (r = -0.581, p = 0.037) and the epidermal detachment area (r = -0.576, p = 0.039). The circRNA-miRNA-mRNA prediction network was used to construct the hsa_circ_0083619/miR-18a-5p/BCL2L10 axis. The hsa_circ_0083619 could serve as a disease severity indicator for SJS/TEN. Through bioinformatics analysis, we speculated that hsa_circ_0083619/miR-18a-5p/BCL2L10 axis might play a role in SJS/TEN pathogenesis.

Role of hsa_circ_0066966 in proliferation and migration of hepatitis B virus-related liver cancer cells

A large proportion of liver cancer cases is caused by hepatitis B virus (HBV) infection. In recent years, an increasing number of reports have indicated that circular RNAs (circRNAs) exert regulatory effects in cancer development, whereas the role of circRNAs in HBV-positive liver cancer requires further investigation. In the present study, abnormally expressed circRNAs were identified in HBV-positive liver cancer cells through microarray analysis. A total of 1,493 differentially expressed circRNAs [absolute fold-change (FC) ≥2] in HBV-positive liver cancer cells were detected, of which 171 were upregulated and 1,322 were downregulated. Subsequently, Gene Ontology enrichment analysis indicated that the genes of dysregulated circRNAs were mainly involved in regulating Sertoli cell differentiation and development, as well as telomeric DNA binding. Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed that most of these genes were enriched in cancer-related signaling pathways, including the MAPK and Hippo signaling pathways. Next, the expression levels of the top-10 dysregulated circRNAs were verified in HBV-positive liver cancer cells through reverse transcription-quantitative PCR. Among them, hsa_circ_0066966 had the highest absolute Log₂FC value and was abnormally increased in HBV-positive liver cancer cells. Functional experiments further verified that knockdown of hsa_circ_0066966 had a significant inhibitory effect on the proliferation and migration of HBV-positive liver cancer cells. By contrast, overexpression of hsa_circ_0066966 in HBV-negative liver cancer cells resulted in the opposite effect. In conclusion, in the present study, comprehensive circRNA profiling in HBV-positive liver cancer cells indicated that hsa_circ_0066966 may regulate the progression of HBV-positive liver cancer.

Circular RNAs Sparkle in the Diagnosis and Theranostics of Hepatocellular Carcinoma

Exonic circular RNAs (circRNAs) are a novel subgroup of non-coding RNAs, which are generated by a back-splicing mechanism of the exons or introns. Unlike the linear RNA, circRNA forms a covalently closed loop, and it normally appears more abundant than the linear products of its host gene. Due to the relatively high specificity and stability of circular RNAs in tissues and body fluid, circular RNAs have attracted widely scientific interest for its potential application in cancer diagnosis and as a guide for preclinical therapy, especially for hard-to-treat cancers with high heterogeneity, such as hepatocellular carcinoma (HCC). Thus, we summarize the updated knowledge of circular RNAs, including the mechanism of the generation of endogenous circular RNAs and their regulatory, diagnostic, and therapeutic roles in HCC.