Circular RNA circ-CSPP1 regulates CCNE2 to facilitate hepatocellular carcinoma cell growth via sponging miR-577

Epigenetic regulation of hepatocellular carcinoma progression: MicroRNAs as therapeutic, diagnostic and prognostic factors

Hepatocellular carcinoma (HCC), a significant challenge for public healthcare systems in developed Western countries including the USA, Canada, and the UK, is influenced by different risk factors including hepatitis virus infections, alcoholism, and smoking. The disruption in the balance of microRNAs (miRNAs) plays a vital function in tumorigenesis, given their function as regulators in numerous signaling networks. These miRNAs, which are mature and active in the cytoplasm, work by reducing the expression of target genes through their impact on mRNAs. MiRNAs are particularly significant in HCC as they regulate key aspects of the tumor, like proliferation and invasion. Additionally, during treatment phases such as chemotherapy and radiotherapy, the levels of miRNAs are key determinants. Pre-clinical experiments have demonstrated that altered miRNA expression contributes to HCC development, metastasis, drug resistance, and radio-resistance, highlighting related molecular pathways and processes like MMPs, EMT, apoptosis, and autophagy. Furthermore, the regulatory role of miRNAs in HCC extends beyond their immediate function, as they are also influenced by other epigenetic factors like lncRNAs and circular RNAs (circRNAs), as discussed in recent reviews. Applying these discoveries in predicting the prognosis of HCC could mark a significant advancement in the therapy of this disease.

Circular RNAs in hepatocellular carcinoma: biogenesis, function, and pathology

Hepatocellular carcinoma (HCC) is one of the most common causes of cancer-related death worldwide. Both genetic and environmental factors through a multitude of underlying molecular mechanisms participate in the pathogenesis of HCC. Recently, numerous studies have shown that circular RNAs (circRNAs), an emerging class of non-coding RNAs characterized by the presence of covalent bonds linking 3' and 5' ends, play an important role in the initiation and progression of cancers, including HCC. In this review, we outline the current status of the field of circRNAs, with an emphasis on the functions and mechanisms of circRNAs in HCC and its microenvironment. We also summarize and discuss recent advances of circRNAs as biomarkers and therapeutic targets. These efforts are anticipated to throw new insights into future perspectives about circRNAs in basic, translational and clinical research, eventually advancing the diagnosis, prevention and treatment of HCC.

Retraction Note: Long noncoding RNA LINC00968 inhibits proliferation, migration and invasion of lung adenocarcinoma through targeting miR-22-5p/CDC14A axis

[This retracts the article DOI: 10.1007/s13205-021-02981-8.].

Development and validation of a potential biomarker to improve the assessment of liver fibrosis progression in patients with chronic hepatitis B

We aimed to develop and validate a novel combined score to improve the assessment of liver fibrosis progression in patients with chronic hepatitis B (CHB). In this study, a total of 331 CHB patients from three cohorts who underwent liver biopsy were enrolled, and the Scheuer system was used for liver fibrosis classification. The combined score was derived by principal component analysis of key differentially expressed genes. For significant liver fibrosis (≥S2), the areas under the receiver operating characteristics curves (AUROCs) of the combined score were 0.838, 0.842, and 0.881 in the three cohorts, respectively. And for advanced liver fibrosis (≥S3), the AUROCs were 0.794, 0.801, and 0.901, respectively. Compared with the results of AUROCs for aspartate aminotransferase≥to≥platelet ratio (APRI) and fibrosis index based on four factors (FIB-4) in the validation cohorts, better clinical diagnostic value for assessing the progression of liver fibrosis was found in the combined score. Additionally, univariate ordered logistic regression analysis indicated that the combined score could serve as a more superior and stable risk factor than APRI and FIB-4 in the assessment of liver fibrosis. For CHB patients with normal alanine aminotransferase (ALT), our results further emphasized the diagnostic value of the combined score for significant fibrosis (≥S2) and advanced fibrosis (≥S3). Moreover, it was found that patients with the high combined score, who were associated with the advanced fibrosis stage, had higher levels of drug sensitivity and immune checkpoint expression. In conclusion, the novel combined score could serve as a potential biomarker and contribute to improving the assessment of fibrosis stage in CHB patients.

During HCV DAA Therapy Plasma Mip1B, IP10, and miRNA Profile Are Distinctly Associated with Subsequent Diagnosis of Hepatocellular Carcinoma: A Pilot Study

Background: Hepatitis C virus (HCV) therapy lowers risk of hepatocellular carcinoma (HCC). Little is known about factors driving/preceding HCC in treated persons. MicroRNAs (miRNAs) and long non-coding RNAs (lncRNAs) regulate host response and pathogenesis of disease. We investigated plasma levels of these RNAs and select serum markers before, during, and after HCV therapy, preceding HCC. Methods: Of 187 DAA treated HCV patients where therapy oriented longitudinal sampling was performed at a time without HCC diagnosis, 9 were subsequently diagnosed with HCC within 2 years of therapy. They were matched with 7 patients not diagnosed with HCC over the same time period. RNASeq was performed on plasma, and serum was assessed for biomarkers of inflammation by ELISA. Results: HCC diagnosis was 19 months (6-28) after therapy start in the HCC group. 73 and 63 miRs were differentially expressed at baseline (before DAA therapy) and 12 weeks after DAA therapy comparing HCC and non-HCC groups. Several lncRNA- showed differential expression as well. Several miRNA suppressors of cancer-related pathways, lncRNA- and mRNA-derived stabilized short RNAs were consistently absent in the plasma of patients who developed HCC. Serum IP10, and MCP-1 level was higher in the HCC group 12 weeks after therapy, and distinct miRNAs correlated with IP10 and MCP-1. Finally, in a focused analysis of 8 miRNAs best associated with HCC we observed expression of mi576 and mi-5189 correlation with expression of a select group of PBMC mRNA. Conclusions: These results are consistent with complex interplay between RNA-mediated host immune regulation and cancer suppression, strikingly skewed 12 weeks following therapy, prior to HCC diagnosis.

The function and regulation network mechanism of circRNA in liver diseases

Circular RNA (circRNA), a new type of endogenous non-coding RNA, is abundantly present in eukaryotic cells, and characterized as stable high conservation and tissue specific expression. It has been generated increasing attention because of their close association with the progress of diseases. The liver is the vital organ of humans, while it is prone to acute and chronic diseases due to the influence of multiple pathogenic factors. Moreover, hepatocellular carcinoma (HCC) is the one of most common cancer and the leading cause of cancer death worldwide. Overwhelming evidences indicate that some circRNAs are differentially expressed in liver diseases, such as, HCC, chronic hepatitis B, hepatic steatosis and hepatoblastoma tissues, etc. Additionally, these circRNAs are related to proliferation, invasion, migration, angiogenesis, apoptosis, and metastasis of cell in liver diseases and act as oncogenic agents or suppressors, and linked to clinical manifestations. In this review, we briefly summarize the biogenesis, characterization and biological functions, recent detection and identification technologies of circRNA, and regulation network mechanism of circRNA in liver diseases, and discuss their potential values as biomarkers or therapeutic targets for liver diseases, especially on HCC.

Circular RNA hsa_circ_0000073 Enhances Osteosarcoma Cells Malignant Behavior by Sponging miR-1252-5p and Modulating CCNE2 and MDM2

Objective: An increasing number of studies have demonstrated that circular RNAs (circRNAs) are involved in tumor progression. However, the role of hsa_circ_0000073 in osteosarcoma (OS) is still not fully elucidated.

Methods: Quantitative reverse transcription-polymerase chain reaction or Western blot was used to detect the gene expression. GeneChip analysis, bioinformatics, luciferase reporter, and RNA immunoprecipitation assays were adopted to predict and verify the relationships between genes. Counting Kit-8 Assay, clone formation assay, wound-healing assay, transwell assays, cell cycle assays, and in vivo tumorigenesis were used to evaluate cell function.

Results: hsa_circ_0000073 was highly expressed in OS cell lines and could promote OS progression, including proliferation, migration, invasion, and cell cycle in vitro as well as tumorigenesis in vivo. Mechanically, hsa_circ_0000073 could readily downregulate the expression of CCNE2 and MDM2 through miR-1252-5p. Rescue experiments validated miR-1252-5p mimics, or CCNE2/MDM2 short hairpin RNA could reverse the hsa_circ_0000073 overexpressing-induced impairment of malignant tumor behavior.

Conclusion: hsa_circ_0000073 functions as a tumor promoter in OS to increase malignant tumor behavior through sponging miR-1252-5p and regulating CCNE2 and MDM2 expression, which could be a novel target for OS therapy.

Circ_0072995 Promotes Proliferation and Invasion via Regulating miR-1253/EIF4A3 Signaling in HCC

Background

Hepatocellular carcinoma (HCC) is a major threat for human health. This work aimed to determine the potential function of circ_0072995 in HCC progression and its molecular mechanism.

Methods

qRT-PCR was conducted to analyze circ_0072995 expression. CCK8 and colony formation assays were utilized to detect cell proliferation. Transwell assay was performed to determine migration and invasion. Interactions among circ_0072995, miR-1253 and EIF4A3 (Eukaryotic Translation Initiation Factor 4A3) were predicted through bioinformatics methods and confirmed via luciferase reporter assay and RNA pulldown assay.

Results

circ_0072995 expression was upregulated in HCC tissues. Circ_0072995 high level was associated with poor prognosis. Circ_0072995 knockdown impaired proliferation, migration, invasion and survival. MiR-1253 was sponged by circ_0072995 and targeted EIF4A3 directly. Circ_0072995 inhibited miR-1253 to upregulate EIF4A3 level.

Conclusion

Circ_0072995 exerted tumorigenic roles to enhance HCC progression through activating EIF4A3 by sponging miR-1253.

circMYC promotes cell proliferation, metastasis, and glycolysis in cervical cancer by up-regulating MET and sponging miR-577

OBJECTIVE

To analyze the role of circMYC in cervical cancer.

METHODS

Protein and RNA expression was detected by RT-qPCR and western blotting. Transwell, CCK8, and colony formation assays were used for measuring metastasis, cell viability, and proliferation, respectively. Lactate production, glucose uptake, and ATP generation were examined to evaluate cell glycolysis. Interactions between circMYC, miR-577, and MET were determined by RNA pull-down and immunoprecipitation, and dual-luciferase reporter assays. Xenografts were established in mice to evaluate the functions of circMYC in vivo.

RESULTS

circMYC was overexpressed in tumor tissue, which was related to poor prognosis. CircMYC knockdown reduced proliferation, colony formation, metastasis, and glycolysis in cervical cancer cells as well as inhibiting tumor growth in vivo. Mechanistically, circMYC targeted miR-577, and the effects of circMYC knockdown could be reversed by miR-577 inhibition. Moreover, miR-577 downregulated the expression of MET. Therefore, the oncogenic role of circMYC in cervical cancer was achieved by sponging miR-577 and maintaining MET expression.

CONCLUSION

circMYC promotes cervical cancer progression through regulation of the miR-577/MET axis. circMYC may thus be a potential target for diagnosing and treating cervical cancer.

Identification of circRNA circ-CSPP1 as a potent driver of colorectal cancer by directly targeting the miR-431/LASP1 axis

Colorectal cancer (CRC) is the third most common malignancy worldwide. Circular RNAs (circRNAs) have been implicated in cancer biology. The purpose of the current work is to investigate the precise parts of circRNA centrosome and spindle pole-associated protein 1 (circ-CSPP1) in the progression of CRC. Our data showed that circ-CSPP1 was significantly overexpressed in CRC tissues and cells. The knockdown of circ-CSPP1 attenuated cell proliferation, migration, invasion and promoted apoptosis in vitro and weakened tumor growth in vivo. circ-CSPP1 directly targeted miR-431, and circ-CSPP1 knockdown modulated CRC cell progression in vitro via upregulating miR-431. Moreover, LIM and SH3 protein 1 (LASP1) was a functional target of miR-431 in modulating CRC cell malignant progression. Furthermore, circ-CSPP1 in CRC cells functioned as a posttranscriptional regulator on LASP1 expression by targeting miR-431. Our present study identified the oncogenic role of circ-CSPP1 in CRC partially by the modulation of the miR-431/LASP1 axis, providing evidence for circ-CSPP1 as a promising biomarker for CRC management.

Expression of Cell Division Cycle Protein 45 in Tissue Microarrays and the CDC45 Gene by Bioinformatics Analysis in Human Hepatocellular Carcinoma and Patient Outcomes

Background

Hepatocellular carcinoma (HCC) causes a heavy disease burden worldwide. Cell division cycle 45 (Cdc45) and its encoding gene (CDC45) have been studied for a long time, but their expression patterns and roles in liver carcinogenesis and advanced HCC deterioration are still incompletely understood. This study integrated tissue microarray and bioinformatics analyses to explore the expression and clinical value of CDC45 and Cdc45 in HCC.

Material/Methods

In HCC, the expression and relationships with clinic-pathological parameters of CDC45 and Cdc45 were investigated by integrating the RNA-sequencing data, downloaded from The Cancer Genome Atlas and Oncomine databases, and tissue microarray with immunohistochemistry staining. Co-expressed genes and genetic alterations of CDC45 separately obtained from Oncomine and cBioPortal databases were identified to shed light on the potential mechanisms of CDC45 in HCC.

Results

CDC45 and Cdc45 were both overexpressed in HCC tissues, and the CDC45 level progressively increased from stage I to III. The survival outcomes of the group with high CDC45 expression were significantly worse compared with the group with low expression. Amplification and deep deletion were 2 major significant alteration types in HCC patients, and the outcomes were worse in patients with altered versus unaltered CDC45. NUDT1, E2F1, CCNE2, MCM5, and CENPM were identified as the most significantly co-expressed genes.

Conclusions

CDC45 and Cdc45 were both upregulated in HCC, and increased expression levels and genetic alternations of CDC45 were correlated with worse prognosis in HCC patients. CDC45 may promote HCC by co-expressing with NUDT1, E2F1, CCNE2, MCM5, and CENPM.

Recent Update on the Role of Circular RNAs in Hepatocellular Carcinoma

After being overlooked for decades, circular RNAs (circRNAs) have recently generated considerable interest. circRNAs play a role in a variety of normal and pathological biological processes, including hepatocarcinogenesis. Many circRNAs contribute to hepatocarcinogenesis through sponging of microRNAs (miRs) and disruption of cellular signaling pathways that play a part in control of cell proliferation, metastasis and apoptosis. In most cases, overexpressed circRNAs sequester miRs to cause de-repressed translation of mRNAs that encode oncogenic proteins. Conversely, low expression of circRNAs has also been described in hepatocellular carcinoma (HCC) and is associated with inhibited production of tumor suppressor proteins. Other functions of circRNAs that contribute to hepatocarcinogenesis include translation of truncated proteins and acting as adapters to regulate influence of transcription factors on target gene expression. circRNAs also affect hepatocyte transformation indirectly. For example, the molecules regulate immune surveillance of cancerous cells and influence the liver fibrosis that commonly precedes HCC. Marked over- or under-expression of circRNA expression in HCC, with correlating plasma concentrations, has diagnostic utility and assays of these RNAs are being developed as biomarkers of HCC. Although knowledge in the field has recently surged, the myriad of described effects suggests that not all may be vital to hepatocarcinogenesis. Nevertheless, investigation of the role of circRNAs is providing valuable insights that are likely to contribute to improved management of a serious and highly aggressive cancer.

Circular RNAs in gastrointestinal cancer: Current knowledge, biomarkers and targeted therapy (Review)

Circular RNAs (circRNAs) are a type of endogenous non‑coding RNAs that are connected at the 3' and 5' ends by exon or intron cyclization, which forms a covalently closed loop. They are stable, well conserved, exhibit specific expression in mammalian cells and can function as microRNA (miRNA or miR) sponges to regulate the target genes of miRNAs, which influences biological processes. Such as tumor proliferation, invasion, metastasis, apoptosis and tumor stage. circRNAs represent promising candidates for clinical diagnosis and treatment. In the present review, the biogenesis, classification and functions of circRNAs in tumors are briefly summarized and discussed. In addition, the participation of circRNAs in signal transduction pathways regulating gastrointestinal cancer cellular functions is highlighted.