Circ_0016760 accelerates non-small-cell lung cancer progression through miR-646/AKT3 signaling in vivo and in vitro

CircWHSC1 (CircNSD2): A Novel Circular RNA in Multiple Cancers

Circular RNAs (circRNAs) are a type of non-coding RNA (ncRNA) that possesses a unique single-stranded circular structure. They are primarily formed through alternative splicing of pre-mRNA (messenger RNA). The primary biological function of circRNAs is to regulate gene expression at both the transcriptional and post-transcriptional levels. Recent studies have increasingly demonstrated a close association between the dysregulation of circRNAs and the progression of diverse cancers, where they can function as either tumor suppressors or oncogenes. circWHSC1 (circNSD2) is a circular ncRNA that originates from the first 2 exons of the Wolf-Hirschhorn syndrome candidate gene (WHSC1). As Chen 2019 discovery that circWHSC1 (circNSD2) functions as a sponge for miRNAs and promotes cancer, this circRNA has garnered significant interest among researchers. circWHSC1 (circNSD2) has been found to be up-regulated in various malignant tumors, including nasopharyngeal carcinoma, lung cancer, breast cancer, liver cancer, colorectal cancer, ovarian cancer, cervical cancer, and endometrial cancer. It exerts its effects on cancer by either inhibiting or promoting the expression of related genes through direct or indirect pathways, ultimately affecting cancer proliferation, invasion, and prognosis. This article provides a comprehensive review and discussion of the biological roles of circWHSC1 (circNSD2) and its target genes in various cancers, as well as the latest research progress on related molecular biological regulatory mechanisms. Furthermore, the potential significance of circWHSC1 (circNSD2) in future clinical applications and transformations is thoroughly analyzed and discussed.

[Overexpression of lncRNA FEZF1-AS1 promotes progression of non-small cell lung cancer via the miR-130a-5p/CCND1 axis]

OBJECTIVE

To explore the molecular mechanism by which FEZF1-AS1 overexpression promotes progression of nonsmall cell lung cancer (NSCLC) via the miR-130a-5p/CCND1 axis.

METHODS

TCGA database was used to analyze FEZF1-AS1 expression levels in NSCLC. FEZF1-AS1 expression was detected by qRT-PCR in clinical specimens of NSCLC tissues and NSCLC cell lines, and its correlation with clinical features of the patients were analyzed. The binding sites of FEZF1-AS1 with hsa-miR-130a-5p and those of hsa-miR-130a-5p with CCND1 were predicted. CCK8 assay, clone formation assay, scratch assay, and Transwell assay were employed to examine the effects of FEZF1-AS1 knockdown and hsa-miR-130a-5p inhibitor on proliferation, invasion, and migration abilities of lung cancer cell lines. Dual luciferase assay was used to verify the binding of FEZF1-AS1 with hsa-miR-130a-5p and the binding of hsa-miR-130a-5p with CCND1. Western blotting was performed to detect the changes in CCND1 protein expression level in H1299 and H358 cells following FEZF1-AS1 knockdown and treatment with hsa-miR-130a-5p inhibitor.

RESULTS

FEZF1-AS1 was highly expressed in NSCLC tissues in close correlation with lymph node metastasis and also in H1299 and H358 cell lines (all P < 0.05). FEZF1-AS1 knockdown obviously reduced proliferation, migration, and invasion abilities of NSCLC cells (P < 0.05). Dual luciferase assay confirmed the binding of hsa-miR-130a-5p with FEZF1-AS1 and CCND1 (P < 0.05), and hsa-miR-130a-5p inhibitor significantly inhibited proliferation, migration, and invasion of NSCLC cells (P < 0.05). FEZF1-AS1 knockdown significantly reduced CCND1 protein expression in NSCLC cells, and this effect was strongly inhibited by treatment with hsa-miR-130a-5p inhibitor (P < 0.05).

CONCLUSION

FEZF1-AS1 is highly expressed in NSCLC tissue in close correlation with lymph node metastasis to promote cancer progression through the miR-130a-5p/CCND1 axis.

The potential role of circular RNAs -regulated PI3K signaling in non-small cell lung cancer: Molecular insights and clinical perspective

Non-small cell lung cancer (NSCLC), accounting for more than 80% of all cases, is the predominant form of lung cancer and the leading cause of cancer-related deaths worldwide. Significant progress has been made in diagnostic techniques, surgical interventions, chemotherapy protocols, and targeted therapies at the molecular level, leading to enhanced treatment outcomes in patients with NSCLC. Extensive evidence supports the use of circular RNAs (circRNAs), a specific category of naturally occurring non-coding small RNAs (ncRNAs), for the diagnosis, monitoring of treatment efficacy, and assessment of survival in NSCLC. CircRNAs have been identified to play significant roles in various aspects of cancer formation, either as tumor suppressors or tumor promoters, contributing to cancer development through several signaling pathways, including the phosphoinositide 3-kinases (PI3Ks) pathway. This pathway is well-established because of its regulatory role in essential cellular processes. CircRNAs regulate the PI3K/AKT pathway by targeting diverse cellular elements. This review aims to provide insight into the involvement of several circRNAs linked to the PI3K/AKT pathway in NSCLC.

Circular RNA in Non-small Cell Lung Carcinoma: Identification of Targets and New Treatment Modalities

Despite availability of several treatment options for non-small cell lung cancer (NSCLC), such as surgery, chemotherapy, radiation, targeted therapy and immunotherapy, the survival rate of patients for five years is in the range of 22%. Therefore, identification of new targets and treatment modalities for this disease is an important issue. In this context, we screened the PubMed database for up-regulated circular RNAs (circRNAs) which promote growth of NSCLC in preclinical models in vitro as well as in vivo xenograft models in immuno-compromised mice. This approach led to potential targets for further validation and inhibition with small molecules or antibody-derived entities. In case of preclinical validation, the corresponding circRNAs can be inhibited with small interfering RNAs (siRNA) or short hairpin RNAs (shRNA). The identified circRNAs act by sponging microRNAs (miRs) preventing cleavage of the mRNA of the corresponding targets. We identified nine circRNAs up-regulating transmembrane receptors, five circRNAs increasing expression of secreted proteins, nine circRNAs promoting expression of components of signaling pathways, six circRNAs involved in regulation of splicing and RNA processing, six circRNAs up-regulating actin-related and RNA processing components, seven circRNAs increasing the steady-state levels of transcription factors, two circRNAs increasing high-mobility group proteins, four circRNAs increasing components of the epigenetic modification system and three circRNAs up-regulating protein components of additional systems.

The Multifunctional Nature of the MicroRNA/AKT3 Regulatory Axis in Human Cancers

Serine/threonine kinase (AKT) signaling regulates diverse cellular processes and is one of the most important aberrant cell survival mechanisms associated with tumorigenesis, metastasis, and chemoresistance. Targeting AKT has become an effective therapeutic strategy for the treatment of many cancers. AKT3 (PKBγ), the least studied isoform of the AKT family, has emerged as a major contributor to malignancy. AKT3 is frequently overexpressed in human cancers, and many regulatory oncogenic or tumor suppressor small non-coding RNAs (ncRNAs), including microRNAs (miRNAs), have recently been identified to be involved in regulating AKT3 expression. Therefore, a better understanding of regulatory miRNA/AKT3 networks may reveal novel biomarkers for the diagnosis of patients with cancer and may provide invaluable information for developing more effective therapeutic strategies. The aim of this review was to summarize current research progress in the isoform-specific functions of AKT3 in human cancers and the roles of dysregulated miRNA/AKT3 in specific types of human cancers.

Macrophages depletion alleviates lung injury by modulating AKT3/GXP4 following ventilator associated pneumonia

Background

AKT3 appears to play a role in lung cancer. However, its role in ventilator-associated pneumonia is still unclear. Therefore, this study aimed to investigate the role of AKT3 in macrophages during ventilator-associated pneumonia.

Methods

The mRNA level of AKT3, Data from The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), The data is analyzed using the Xiantao academic analysis tool. Additionally, the roles of AKT3 in ventilator-associated pneumonia (VAP) were investigated through in vivo experiments.

Results

AKT3 was differentially expressed in various normal and tumor tissues. Functional enrichment analysis indicated the immunomodulatory function and inflammatory response of AKT3 in lung cancer. Depletion of macrophages protected against lung epithelial cells and significantly decreased MMP9, MMP19, FTH, and FTL expression levels and increased GPX4 expression levels, while partially reversing the changes in macrophage. Mechanistically, macrophage depletion attenuates ferroptosis of lung epithelial cells by modulating AKT3 following VAP.

Conclusion

Collectively, this study suggests the need for further validation of the immunoregulatory function of AKT3 in lung cancer. Additionally, macrophage depletion mitigates lung injury by modulating the AKT3/GPX4 pathway in the context of VAP.

EIF4A3-induced circular RNA SCAP facilitates tumorigenesis and progression of non-small-cell lung cancer via miR-7/SMAD2 signaling

The eukaryotic translation initiation factor 4A (eIF4A) family determines transcription efficiency by directly binding to precursor RNAs. One member, EIF4A3, modulates the expression of circRNAs. Circular RNA SCAP (circSCAP), a newly found circRNA, has been implicated in atherosclerosis. Yet, how circSCAP regulates cancer development and progression remains understudied. Here, we investigated the function of circSCAP and the molecular mechanism in the tumorigenesis and progression of non-small-cell lung cancer (NSCLC). CircSCAP was upregulated in both NSCLC tissues and cell lines and was mainly located in the cytoplasm. CircSCAP expression was promoted by EIF4A3, which was associated with poor prognosis in patients with NSCLC. CircSCAP sponged miR-7 to upregulate small mothers against decapentaplegic 2 (SMAD2). CircSCAP knockdown undermined cell proliferation, migration, and invasion abilities in NSCLC cell lines (SPCA1 and A549), which was rescued by either inhibiting miR-7 or overexpressing SMAD2. Moreover, circSCAP knockdown upregulated E-cadherin, while downregulating N-cadherin, Vimentin, and MMP9 in SPCA1 and A549 cells, which were abolished by either inhibiting miR-7 or overexpressing SMAD2. Additionally, miR-7 was markedly downregulated, whereas SMAD2 was significantly upregulated in NSCLC tissues. MiR-7 expression was inversely correlated with circSCAP and SMAD2 expression in NSCLC tissues. In conclusion, this study demonstrates that circSCAP is significantly upregulated in NSCLC cell lines and tissues and elucidates that circSCAP facilitates NSCLC progression by sponging miR-7 and upregulating SMAD2. The study provides a novel molecular target for early diagnosis and treatment of NSCLC.

High Expression of circ_0001821 Promoted Colorectal Cancer Progression Through miR-600/ISOC1 Axis

It has been reported that circRNAs play an important regulatory role in the progression of colorectal cancer (CRC). However, the molecular role of circ_0001821 in CRC development is unclear. In this study, we aimed to investigate the regulatory role and molecular mechanisms of circ_0001821 in CRC. Reverse transcription-quantitative PCR and western blot assays were used to detect the expression of circ_0001821, miR-600 and isochorismatase domain containing 1 (ISOC1) in CRC tissues as well as its cell lines. Colony formation assay and EDU assay were used to detect the proliferative capacity of cells. Transwell assay was used to assess cell migration and invasion ability. Flow cytometry was used to analyze cell apoptosis. ELISA was used to measure the glycolytic capacity of cells. Dual-luciferase reporter assay and RNA pull-down assay were used to analyze the relationships between circ_0001821, miR-600 and ISOC1. Animal experimentation was used to validate the functional study of circ_0001821 in vivo. Immunohistochemistry (IHC) of Ki67 staining analysis was conducted to assess tumor growth. Circ_0001821 and ISOC1 were significantly increased in CRC tissues and its cell lines, and miR-600 was significantly decreased in CRC tissues and its cell lines. Silencing circ_0001821 inhibited cell proliferation, migration, invasion and glycolytic capacity, while inducing apoptosis. And it could inhibit tumor growth in vivo. Circ_0001821 could act as a sponge for miR-600 to regulate CRC processes. ISOC1 was identified as a downstream regulator of miR-600, also miR-600 could regulate the expression of ISOC1. In addition, circ_0001821 could regulate ISOC1 expression changes through miR-600. Mechanistically, either miR-600 inhibitor or overexpression of ISOC1 could reverse the effects of knockdown of circ_0001821 on cell biological properties. Circ_0001821 regulated the developmental process of CRC through miR-600/ISOC1 axis.