CircKIF5B Promotes Hepatocellular Carcinoma Progression by Regulating the miR-192 Family/XIAP Axis

hsa_circ_0000518 stimulates the malignant progression of hepatocellular carcinoma via regulating ITGA5 to activate the Warburg effect

Studies have shown that the abnormal expression of circular RNA (circRNA) is inextricably linked to hepatocellular carcinoma (HCC). Recently, hsa_circ_0000518 (circ_0000518) was discovered in many cancer progressions. However, its function in HCC is still unclear. Through GEO database analysis combined with gene expression detection of HCC related clinical samples and cell lines, we identified that circ_0000518 was abnormally overexpressed in HCC. Cell and animal model experiments jointly indicated that circ_0000518 can stimulate HCC cell proliferation, migration, invasion and suppress apoptosis. Furthermore, we also found that knocking down the circ_0000518 could inhibit the Warburg effect in HCC cells. Mechanistically, circ_0000518 was found to be primarily localized in the cytoplasm, and sponge hsa-miR-326 (miR-326) promoted integrin alpha 5 (ITGA5) expression. In addition, circ_0000518 could enhance the stability of HuR-mediated ITGA5 mRNA, thereby activating the Warburg effect. In conclusion, this study elucidated that circ_0000518 was a cancer-promoting circRNA, which could enhance ITGA5 expression through competing endogenous RNAs (ceRNA) and RNA Binding Protein (RBP) mechanisms, thus facilitating the development of HCC. It provides a meaningful diagnostic and therapeutic target for HCC.

Overexpression of circZNF720 Inhibits Hepatocellular Carcinoma Progression by Regulating miR-421/MAPK9

Hepatocellular carcinoma (HCC) is characterized by high incidence, high death rate and poor long term prognosis. Abnormal expression of circular RNA (circRNA) has been demonstrated to be closely associated with malignant progression of HCC. However, the effect of circZNF720 on HCC is largely incompletely understood. This study sought to explore the effect of circZNF720 on the progression of HCC by CCK-8, transwell, and flow cytometry experiments. The prognosis of circZNF720 on patients was analyzed by Kaplan-Meier curve. Then, the regulatory mechanisms among circZNF720, miR-421, and MAPK9 were identified by qRT-PCR, dual-luciferase reporter assay, and RIP analysis, respectively. The outcomes of this study disclosed that circZNF720 was lowly expressed in HCC, and this low expression was strongly linked with a poor prognosis for HCC patients. Overexpression of circZNF720 inhibited the proliferation, migration, and invasion of cells, and increased the apoptosis of cells. Mechanistic studies revealed that circZNF720 targeted miR-421 and regulated the development of HCC by acting as a sponge for miRNAs. In addition, MAPK9 was a downstream target of miR-421, and circZNF720 introduction hampered HCC progression by upregulating MAPK9 expression through sponging miR-421. In conclusion, circZNF720 restrained HCC progression by targeting miR-421/MAPK9. This study provides a novel target for the treatment of HCC.

CircFOXO3 mediates hypoxia-induced autophagy of endometrial stromal cells in endometriosis

Endometriosis is a benign gynecological disease that shares some common features of malignancy. Autophagy plays vital roles in endometriosis and influences endometrial cell metastasis, and hypoxia was identified as the initiator of this pathological process through hypoxia inducible factor 1 alpha (HIF-1α). A newly discovered circular RNA FOXO3 (circFOXO3) is critical in cell autophagy, migration, and invasion of various diseases and is reported to be related to hypoxia, although its role in endometriosis remains to be elucidated up to now. In this study, a lower circFOXO3 expression in ectopic endometrium was investigated. Furthermore, we verified that circFOXO3 could regulate autophagy by downregulating the level of p53 protein to mediate the migration and invasion of human endometrial stromal cells (T HESCs). Additionally, the effects of HIF-1α on circFOXO3 and autophagy were examined in T HESCs. Notably, overexpression of HIF-1α could induce autophagy and inhibit circFOXO3 expression, whereas overexpressing of circFOXO3 under hypoxia significantly inhibited hypoxia-induced autophagy. Mechanistically, the direct combination between HIF-1α and HIF-1α-binding site on adenosine deaminase 1 acting on RNA (ADAR1) promoter increased the level of ADAR1 protein, which bind directly with circFOXO3 pre-mRNA to block the cyclization of circFOXO3. All these results support that hypoxia-mediated ADAR1 elevation inhibited the expression of circFOXO3, and then autophagy was induced upon loss of circFOXO3 via inhibition of p53 degradation, participating in the development of endometriosis.

Identification and verification of a prognostic autophagy-related gene signature in hepatocellular carcinoma

This study aimed to investigate the potential of autophagy-related genes (ATGs) as a prognostic signature for HCC and explore their relationships with immune cells and immune checkpoint molecules. A total of 483 samples were collected from the GEO database (n = 115) and The Cancer Genome Atlas (TCGA) database (n = 368). The GEO dataset was used as the training set, while the TCGA dataset was used for validation. The list of ATGs was obtained from the human autophagy database (HADB). Using Cox regression and LASSO regression methods, a prognostic signature based on ATGs was established. The independent use of this prognostic signature was tested through subgroup analysis. Additionally, the predictive value of this signature for immune-related profiles was explored. Following selection through univariate Cox regression analysis and iterative LASSO Cox analysis, a total of 11 ATGs were used in the GEO dataset to establish a prognostic signature that stratified patients into high- and low-risk groups based on survival. The robustness of this prognostic signature was validated using an external dataset. This signature remained a prognostic factor even in subgroups with different clinical features. Analysis of immune profiles revealed that patients in the high-risk group exhibited immunosuppressive states characterized by lower immune scores and ESTIMATE scores, greater tumour purity, and increased expression of immune checkpoint molecules. Furthermore, this signature was found to be correlated with the infiltration of different immune cell subpopulations. The results suggest that the ATG-based signature can be utilized to evaluate the prognosis of HCC patients and predict the immune status within the tumour microenvironment (TME). However, it is important to note that this study represents a preliminary attempt to use ATGs as prognostic indicators for HCC, and further validation is necessary to determine the predictive power of this signature.

circELMOD3 increases and stabilizes TRIM13 by sponging miR-6864-5p and direct binding to inhibit HCC progression

Many circular RNAs (circRNAs) have been identified to be associated with hepatocellular carcinoma (HCC) progression. We aim to explore the diagnostic potential, functions, and mechanism of circELMOD3 in HCC. Differentially expressed circRNAs in HCC and its paired adjacent tissues were identified by RNA sequencing. circELMOD3 was downregulated in HCC tissues and was related to clinicopathological characteristics of HCC patients. Additionally, plasma circELMOD3 was shown to be a highly sensitive and non-invasive biomarker to distinguish HCC from healthy controls. Functional assays showed that circELMOD3 inhibited proliferation and induced apoptosis of HCC cells both in vitro and in vivo. Mechanistically, RNA antisense purification (RAP) and luciferase reporter assays verified that circELMOD3 functioned as a sponge for miR-6864-5p leading to increased expression of its target gene TRIM13. Interestingly, RNA stability test demonstrated that circELMOD3 overexpression led to enhanced stability of its directly bound TRIM13 mRNA, which in turn co-activated the p53 signaling pathway.

Roles of microRNA-192 in diabetic nephropathy: the clinical applications and mechanisms of action

Diabetic nephropathy (DN) is one of the most common and intractable microvascular complications of diabetes worldwide, serving as the main cause of terminal renal disease. Due to the lack of early specific symptoms and diagnostic markers, DN severely threatens the sufferer's life. MicroRNA-192 (miR-192) was early identified in human renal cortical tissue and stored and excreted in urine as microvesicles. MiR-192 was found to be involved in the development of DN. For the first time, the present review summarized all the current evidence on the topic of the roles of miR-192 in DN. Finally, 28 studies (ten clinical trials and eighteen experimental studies) were eligible for thorough reviewing. Most of the clinical trials (7/10, 70%) indicated miR-192 might be a protective factor for DN development and progression, while the majority of experimental studies (14/18, 78%) suggested miR-192 might be a pathogenic factor for DN. Mechanistically, miR-192 interacts with various direct targeted proteins (i.e., ZEB1, ZEB2, SIP1, GLP1R, and Egr1) and signaling cascades (i.e., SMAD/TGF-β and PTEN/PI3K/AKT), together contribute to the pathogenesis of DN through epithelial-to-mesenchymal transition (EMT), extracellular matrix deposition, and fibrosis formation. The current review highlights the dual role of miR-192 in the development of DN. Low serum miR-192 expression could be applied for the early prediction of DN (the early stage of DN), while the high miR-192 level in renal tissues and urine may imply the progression of DN (the late stage of DN). Further investigations are still warranted to illustrate this inconsistent phenomenon, which may facilitate promoting the therapeutic applications of miR-192 in predicting and treating DN.

Inhibition of circular RNA ASPH reduces the proliferation and promotes the apoptosis of hepatic stellate cells in hepatic fibrosis

Circular RNAs (circRNAs) are a newly identified form of non-coding RNA that play a crucial role in various pathological processes. However, the expression profile and function of circRNAs in hepatic fibrosis (HF) remain largely unknown. In this study, we showed that a novel circRNA ASPH (circASPH) mediates HF by targeting the miR-139-5p/Notch1 axis. We investigated the expression profile of circRNAs in hepatocyte exosomes of mice with HF using circRNA-sequencing and found significant upregulation of circASPH. Loss- and gain-of-function analysis of circASPH was performed to assess its role in HF. Furthermore, we performed luciferase reporter assay, RNA pull-down, and fluorescence in situ hybridization analyses and confirmed that circASPH directly binds to miR-139-5p. We also found that circASPH was upregulated in liver fibrogenesis. Downregulation of circASPH expression inhibited hepatic stellate cell (HSC) activation and proliferation, induced apoptosis, and attenuated mouse liver fibrogenic injury. Mechanistically, circASPH directly targeted miR-139-5p to regulate the expression of Notch1 in HF. Thus, downregulation of circASPH may suppress the activation of HSCs and HF through the circASPH/miR-139-5p/Notch1 axis. Our findings indicated that circASPH may be a potential biomarker for HF diagnosis and therapy.