Long noncoding RNA NR2F1-AS1 promotes the malignancy of non-small cell lung cancer via sponging microRNA-493-5p and thereby increasing ITGB1 expression

LncRNA NR2F1-AS1 as a potential biomarker for prognosis in cancer patients: meta and bioinformatics analysis

BACKGROUND

Previous studies have shown that the differential expression of lncRNA NR2F1-AS1 is closely related to the prognosis of cancer, but the conclusion is still controversial. Therefore, we conducted a meta-analysis and bioinformatics analysis to explore the correlation between LncRNA NR2F1-AS1 and cancer prognosis.

METHODS

From the beginning to January 25, 2023, we searched for correlational studies on PubMed, Embase, the Cochrane Library, and Web of Science. We used pooled hazard ratios (HRs) and odds ratios (ORs) with 95% confidence intervals (CIs) to determine the importance of LncRNA NR2F1-AS1 for survival and clinicopathological features of human cancers.

RESULTS

The meta-analysis of 637 patients in the 11 included articles showed that upregulation of LncRNA NR2F1-AS1 was associated with shorter overall survival (HR = 1.46,95%Cl 1.06-2.01, p = 0.02) in cancer patients. In addition, overexpression of LncRNA NR2F1-AS1 predicted TNM tumor stage (OR = 3.37, 95%Cl 2.07-5.48, p < 0.00001), and Distant metastasis (OR = 0.18, 95%Cl 0.06-0.48, p = 0.0007). However, the difference in age (OR = 1.10,95%Cl 0.71-1.71, p = 0.67), gender (OR = 1.26,95%Cl 0.79-2.00, p = 0.34), Lymph node metastasis (OR = 1.44,95%Cl 0.27-7.80, p = 0.67) or larger tumor size (OR = 1.56,95%Cl 0.48-5.08, p = 0.46) was not statistically significant.

CONCLUSION

Upregulation of LncRNA NR2F1-AS1 was associated with poor prognosis and advanced clinicopathologic features of tumor patients.

Non-coding RNA regulation of integrins and their potential as therapeutic targets in cancer

BACKGROUND

Integrins are integral to cell signalling and management of the extracellular matrix, and exquisite regulation of their expression is essential for a variety of cell signalling pathways, whilst disordered regulation is a key driver of tumour progression and metastasis. Most recently non-coding RNAs in the form of micro-RNA (miRNA) and long non-coding RNA (lncRNA) have emerged as a key mechanism by which tissue dependent gene expression is controlled. Whilst historically these molecules have been poorly understood, advances in 'omic' technologies and a greater understanding of non-coding regions of the genome have revealed that non-coding RNAs make up a large proportion of the transcriptome.

CONCLUSIONS AND PERSPECTIVES

This review examines the regulation of integrin genes by ncRNAs, provides and overview of their mechanism of action and highlights how exploitation of these discoveries is informing the development of novel chemotherapeutic agents in the treatment of cancer. MiRNA molecules have been the most extensively characterised and negatively regulate most integrin genes, classically regulating genes through binding to recognition sequences in the mRNA 3'-untranslated regions of gene transcripts. LncRNA mechanisms of action are now being elucidated and appear to be more varied and complex, and may counter miRNA molecules, directly engage integrin mRNA transcripts, and guide or block both transcription factors and epigenetic machinery at integrin promoters or at other points in integrin regulation. Integrins as therapeutic targets are of enormous interest given their roles as oncogenes in a variety of tumours, and emerging therapeutics mimicking ncRNA mechanisms of action are already being trialled.

Propofol-mediated circ_0000735 downregulation restrains tumor growth by decreasing integrin-β1 expression in non-small cell lung cancer

Propofol, an intravenous anesthetic agent, exerts an anti-tumor peculiarity in multifarious tumors. Circular RNA hsa_circ_0000735 (circ_0000735) is involved in non-small cell lung cancer (NSCLC) progression. The purpose of this study is to investigate whether propofol can curb NSCLC progression via regulating circ_0000735 expression. Cell viability, proliferation, apoptosis, and invasion were detected using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, 5-ethynyl-2'-deoxyuridine, flow cytometry, and transwell assays. Evaluation of protein levels was performed using western blotting or immunohistochemistry. Detection of circ_0000735 in tissue samples and cells was carried out using a real-time quantitative polymerase chain reaction. The molecular mechanisms associated with circ_0000735 were predicted by bioinformatics analysis and verified by dual-luciferase reporter assays. The relationship between propofol and circ_0000735 in vivo was verified by xenograft models. The results showed that circ_0000735 was overexpressed in NSCLC samples and cells. Propofol treatment overtly decreased circ_0000735 expression in NSCLC cells and repressed NSCLC cell viability, proliferation, invasion, and facilitated NSCLC cell apoptosis, but these effects mediated by propofol were counteracted by circ_0000735 overexpression. Circ_0000735 functioned as a miR-153-3p sponge and regulated integrin-β1 (ITGB1) expression via adsorbing miR-153-3p. ITGB1 overexpression reversed circ_0000735 silencing-mediated effects on NSCLC cell viability, proliferation, invasion, and apoptosis. In conclusion, propofol restrained NSCLC growth by downregulating circ_0000735, which functioned as a miR-153-3p sponge and regulated ITGB1 expression via adsorbing miR-153-3p. This study provides evidence to support that propofol curbs NSCLC progression by regulating circRNA expression.

A review on the role of NR2F1-AS1 in the development of cancer

NR2F1-AS1 is a natural antisense transcript with prominent roles in the carcinogenesis. It acts as an oncogene in almost all types of cancers except for cervical and colorectal cancers. It can act as a molecular sponge for miR-17, miR-371a-3p, miR-363, miR-29a-3p, miR-493-5p, miR-190a, miR-140, miR-642a, miR-363, miR-493-5p, miR-483-3p, miR-485-5p, miR-146a-5p, miR-877-5p, miR-338-3 P and miR-423-5p to influence expression of several cancer-related genes. Thus, the sponging role of NR2F1-AS1 is the most appreciated route of its contribution in the carcinogenesis. In addition, NR2F1-AS1 affects activity of IGF-1/IGF-1R/ERK, PI3K/AKT/GSK-3β and Hedgehog pathways. The current narrative review aims at summarization of the results of studies that highlighted the role of NR2F1-AS1 in the carcinogenesis.

Micro-ribonucleic acids (miRNAs) and a proteomic profile in lung adenocarcinoma cases with brain metastasis

Background

Brain metastasis (BM) is the main cause of death of individuals with lung adenocarcinoma (LAC). Biomarkers with high sensitivity and specificity for the early detection and treatment of BM of LAC urgently need to be identified. In this study, we analyzed the pathogenesis of LAC-induced BM by detecting micro-ribonucleic acid (miRNA) and proteome expression differences between primary LAC lesion and BM tissue specimens to identify biomarkers of LAC-associated BM and develop potential therapeutic targets.

Methods

The miRNA and protein profiles of non-metastatic primary LAC and BM cases were examined to further explore the mechanism of BM. The roles and interactions of differential miRNAs and proteins were subject to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. The interactions of differential miRNAs and proteins were analyzed by R software and depicted using Cytoscape.

Results

Compared to the LAC tissue specimens, 16 and 4 miRNAs showed increased and reduced levels, respectively, in the BM tissue specimens, and 53 proteins were upregulated, and 35 proteins were downregulated. The enrichment pathway analysis showed the nuclear factor kappa B (NF-κB) signaling and the primary immunodeficiency pathways played important roles in the pathogenetic mechanisms of BM in LAC.

Conclusions

This study extended understandings of the regulatory network of miRNAs and proteins and provided novel insights into the pathogenic mechanisms of BM in LAC at the miRNA and protein levels.

Non-coding genome in small cell lung cancer between theoretical view and clinical applications

Small cell lung cancer (SCLC) is a highly aggressive cancer of the neuroendocrine system, characterized by poor differentiation, rapid growth, and poor overall survival (OS) of patients. Despite the recent advances in the treatment of SCLC recently, the 2-year survival rate of patients with the cancer is only 14-15%, occasioned by the acquired resistance to drugs and serious off-target effects. In humans, the coding region is only 2% of the total genome, and 20% of that is associated with human diseases. Beyond the coding genome are RNAs, promoters, enhancers, and other intricate elements. The non-coding regulatory regions, mainly the non-coding RNAs (ncRNAs), regulate numerous biological activities including cell proliferation, metastasis, and drug resistance. As such, they are potential diagnostic or prognostic biomarkers, and also potential therapeutic targets for SCLC. Therefore, understanding how non-coding elements regulate SCLC development and progression holds significant clinical implications. Herein, we summarized the recent discoveries on the relationship between the non-coding elements including long non-coding RNAs (lncRNA), microRNAs (miRNAs), circular RNA (circRNA), enhancers as well as promotors, and the pathogenesis of SCLC and their potential clinical applications.

The prognostic and immune infiltration role of ITGB superfamily members in non-small cell lung cancer

PURPOSE

We aimed to explore the prognostic value of integrin-β superfamily members (ITGBs) and their role in immune cell infiltration in non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

Study cases were acquired from The Cancer Genome Atlas database and The Human Protein Atlas. We then used R package and several online tools to analyze and visualize the roles of ITGBs in lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC).

RESULTS

We found that ITGBs were differentially expressed in NSCLC. In LUAD, high expression of ITGB1 and ITGB4 was an independent risk factor for poor prognosis, and ITGB7 was an independent protective factor for overall survival; in LUSC, high expression of ITGB1, 3, 5, and 6 was associated with poor prognosis, and ITGB8 was an independent protective factor for disease-specific survival. Protein-protein interaction networks for the most associated co-expressed genes revealed the following target genes of ITGBs: PTPRC, ITGAM, and ITGB2 in LUAD and FN1, PTPRC, and ITGB2 in LUSC. Gene ontology analysis revealed that functions related to adhesion, junction, and binding were highly enriched in LUAD and LUSC. ITGBs were significantly associated with immune cell infiltration and the expression of immunomodulation-related genes in LUAD and LUSC.

CONCLUSION

ITGBs were differentially expressed in NSCLC. ITGB1, 4, and 7 and ITGB1, 3, 5, 6, and 8 were found as prognostic markers in LUAD and LUSC, respectively. ITGBs were significantly associated with immune cell infiltration and the expression of immunomodulation-related genes.

Comprehensive Analysis of Subtypes and Identification of Key lncRNAs Based on Glutamine Metabolism-Related Long Noncoding RNAs

Background

Long noncoding RNAs (lncRNAs) are becoming a critical class of metabolic regulate molecule in cancer. Glutamine is a regulator that contributes to each of the core metabolic tasks in proliferating tumor cells. Thus, we aimed to evaluate the association of lncRNAs with glutamine metabolism in lung adenocarcinoma (LUAD).

Methods

Using single-sample gene set enrichment analysis (ssGSEA), LUAD specimens were assigned scores based on glutamine metabolism-related genes, and the shared common glutamine metabolism-related lncRNAs in three different LUAD data cohorts were identified. ConsensusClusterPlus was used to perform unsupervised clustering analysis in patients with LUAD. Key glutamine metabolism-related lncRNAs were identified by first-order partial correlation analysis.

Results

A total of 11 shared glutamine metabolism-associated lncRNAs were identified in three LUAD data cohorts, and LUAD patients were classified into three glutamine metabolism subtypes based on the expressions of the related genes. C1 exhibited shorter overall survival (OS), poor genomic instability, and inadequate infiltration of immune cell types in the tumor microenvironment (TME) and was representative of the immunodeficiency phenotype. C2 represented the immunosuppressive phenotype while C3 represented the immune activation phenotype, exhibiting the highest sensitivity to immunotherapy. Nine of the 11 lncRNAs were localized to the nucleus. Finally, three key lncRNAs, significantly enriched in multiple metabolic pathways, were screened and found to be remarkably related to the OS of LUAD.

Conclusion

We identified three glutamine metabolism subtypes of LUAD, which reflected different OS, genomic, and TME features, and identified three key glutamine metabolism-associated lncRNAs may contribute to further study of lncRNAs in cancer metabolism.

The Comprehensive Analysis Identified an Autophagy Signature for the Prognosis and the Immunotherapy Efficiency Prediction in Lung Adenocarcinoma

Background

Lung adenocarcinoma (LUAD) is a fatal malignancy in the world. Growing evidence demonstrated that autophagy-related genes regulated the immune cell infiltration and correlated with the prognosis of LUAD. However, the autophagy-based signature that can predict the prognosis and the efficiency of checkpoint immunotherapy in LUAD patients is yet to be discovered.

Methods

We used conventional autophagy-related genes to screen candidates for signature construction in TCGA cohort and 9 GEO datasets (tumor samples, n=2181; normal samples, n=419). An autophagy-based signature was constructed, its correlation with the prognosis and the immune infiltration of LUAD patients was explored. The prognostic value of the autophagy-based signature was validated in an independent cohort with 70 LUAD patients. Single-cell sequencing data was used to further characterize the various immunological patterns in tumors with different signature levels. Moreover, the predictive value of autophagy-based signature in PD-1 immunotherapy was explored in the IMvigor210 dataset. At last, the protective role of DRAM1 in LUAD was validated by in vitro experiments.

Results

After screening autophagy-related gene candidates, a signature composed by CCR2, ITGB1, and DRAM1 was established with the ATscore in each sample. Further analyses showed that the ATscore was significantly associated with immune cell infiltration and low ATscore indicated poor prognosis. Meanwhile, the prognostic value of ATscore was validated in our independent LUAD cohort. GSEA analyses and single-cell sequencing analyses revealed that ATscore was associated with the immunological status of LUAD tumors, and ATscore could predict the efficacy of PD-1 immunotherapy. Moreover, in vitro experiments demonstrated that the inhibition of DRAM1 suppressed the proliferation and migration capacity of LUAD cells.

Conclusion

Our study identified a new autophagy-based signature that can predict the prognosis of LUAD patients, and this ATscore has potential applicative value in the checkpoint therapy efficiency prediction.

Circ_VANGL1 affects proliferation, migration, and invasion of colorectal cancer cells by regulating miR-493-5p/FXR1 axis

BACKGROUND

CircRNAs are abnormally expressed in colorectal cancer (CRC) tissues, cell lines, and plasma, and are closely related to the clinical malignant characteristics of CRC. However, the expression and functional mechanism of circ_VANGL1 in CRC are still unclear. We hypothesized that circ_VANGL1 affects the proliferation, migration, and invasion of CRC cells by regulating the miR-493-5p/fragile X-related gene 1 (FXR1) axis.

AIM

To investigate the effect of circ_VANGL1 on the prolife-ration, migration, and invasion of CRC cells and the possible mechanism involved.

METHODS

Western blot was used to detect the expression of FXR1 in CRC tissues and adjacent tissues. RT-qPCR was performed to detect the expression of circ_VANGL1 and miR-493-5p. CRC cells Caco-2 were cultured in vitro and divided into si-circ_VANGL1 group, si-NC group, miR-NC group, miR-493-5p mimic group, and si-circ_VANGL1 + miR-493-5p inhibitor group. CCK-8 and clone formation assays were performed to evaluate the proliferation ability of Caco-2 cells. Transwell assay was employed to evaluate the migration and invasion ability of Caco-2 cells. Dual luciferase reporter assay was used to detect the interaction between RNAs (circ_VANGL1 and miR-493-5p, miR-493-5p, and FXR1).

RESULTS

Compared with tumor adjacent tissues, the relative expression levels of circ_VANGL1 and FXR1 protein in CRC tissue were significantly increased (P < 0.05), but the relative level of miR-493-5p was significantly decreased (P < 0.05). Compared with the si-NC group, the inhibition rate of Caco-2 cells and the relative level of miR-493-5p in the si-circ_VANGL1 group were significantly increased (P < 0.05), but the expression of FXR1 protein, the number of colonies formed, and the migration and invasion ability were significantly reduced (P < 0.05). Compared with the miR-NC group, the inhibition rate of Caco-2 cells in the miR-493-5p mimic group was significantly increased (P < 0.05), but the expression of FXR1 protein, the number of colonies formed, and the migration and invasion ability were significantly reduced (P < 0.05). Circ_VANGL1 directly bound to miR-493-5p. Compared with the si-circ_VANGL1 group, the inhibition rate of Caco-2 cells in the si-circ_VANGL1 + miR-493-5p inhibitor group was significantly reduced (P < 0.05), but the expression of FXR1 protein, the number of colonies formed, and the migration and invasion ability were significantly increased (P < 0.05).

CONCLUSION

Silencing circ_VANGL1 inhibits the proliferation, migration, and invasion of CRC cells by regulating the miR-493-5p/FXR1 axis.

ZEB1-regulated lnc-Nr2f1 promotes the migration and invasion of lung adenocarcinoma cells

Numerous long non-coding RNAs (lncRNAs) are differentially expressed in cancer cells compared with normal cells and are involved in tumor progression and metastasis. Metastasis is initiated by the epithelial-to-mesenchymal transition (EMT) process, which can also be regulated by lncRNAs. Given that ZEB1 is an important transcription factor inducing EMT, we screened lncRNAs controlled by ZEB1 using RNA sequencing in murine lung adenocarcinoma cells. Among several lncRNAs regulated by ZEB1, we selected lnc-Nr2f1. Lnc-Nr2f1 is upregulated by ZEB1 and TGF-β, a potent EMT signal. Growth, migration, and invasion of lung adenocarcinoma cells were decreased after lnc-Nr2f1 knockdown and increased after lnc-Nr2f1 overexpression. Interestingly, lnc-Nr2f1 was transcriptionally controlled by NR2F1, a transcription factor that is transcribed in the antisense direction. NR2F1 was also upregulated and positively correlated with ZEB1, forming a ZEB1/NR2F1/lnc-Nr2f1 axis. Lnc-Nr2f1, in turn, promoted Twist2 transcription through direct binding to its genomic DNA region. Collectively, lnc-Nr2f1 was upregulated by ZEB1 and NR2F1, and promoted migration and invasion of lung adenocarcinoma cells via TWIST2 regulation.

The EMT-induced lncRNA NR2F1-AS1 positively modulates NR2F1 expression and drives gastric cancer via miR-29a-3p/VAMP7 axis

Deregulated lncRNAs play critical roles in tumorigenesis and tumor progression. NR2F1-AS1 is an antisense lncRNA of NR2F1. However, the biological function of NR2F1-AS1 in gastric cancer (GC) remains largely unclear. In this study, we revealed that NR2F1-AS1 and NR2F1 were both positively correlated with the degree of malignancy and predicted poor prognosis in two independent GC cohorts. Besides, NR2F1-AS1 and NR2F1 can respond to Epithelial-to-mesenchymal transition (EMT) signaling in GC, since their expression was increased by TGF-beta treatment and decreased after stable overexpression of OVOL2 in GC cell lines. NR2F1-AS1 and NR2F1 were highly co-expressed in pan-tissues and pan-cancers. Depletion of NR2F1-AS1 compromised the expression level of NR2F1 in GC cells. Furthermore, NR2F1-AS1 knockdown inhibited the proliferation, migration, invasion and G1/S transition of GC cells. More importantly, transcriptome sequencing revealed a novel ceRNA network composed of NR2F1-AS1, miR-29a-3p, and VAMP7 in GC. The overexpression of VAMP7 predicted poor prognosis in GC. Rescue assay confirmed that NR2F1-AS1 promotes GC progression through miR-29a-3p/VAMP7 axis. Our finding highlights that the aberrant expression of NR2F1-AS1 is probably due to the abnormal EMT signaling in GC. LncRNA NR2F1-AS1 plays crucial roles in GC progression by modulating miR-29a-3p/VAMP7 axis, suggesting that NR2F1-AS1 may serve as a potential therapeutic target in GC.

Long noncoding RNA NR2F1-AS1 stimulates the tumorigenic behavior of non-small cell lung cancer cells by sponging miR-363-3p to increase SOX4

Long noncoding RNA (lncRNA), specifically the upregulation of lncRNA NR2F1 antisense RNA 1 (NR2F1-AS1), has been involved in the progression of non-small cell lung cancer (NSCLC), but the mechanisms that underlie this remain unclear. In this study, the expression of NR2F1-AS1, miR-363-3p, and SOX4 was assessed in NSCLC cells. A loss-of-function assay was used to measure the tumorigenicity of NSCLC cells. The glycolysis and glutamine metabolism of NSCLC cells was also measured via extracellular acidification rate, consumption of glucose and glutamine, and production of lactate and ATP. The relationships among NR2F1-AS1, miR-363-3p, and SOX4 were detected via dual-luciferase reporter assay. HK-2, GLS1, and SOX4 levels were also analyzed. We found that both NSCLC tissues and cells had higher levels of NR2F1-AS1. Silencing of NR2F1-AS1 inhibited the tumorigenicity of cells in vitro and reduced the glycolysis and glutamine metabolism of NSCLC cells. Regarding its mechanism, NR2F1-AS1 positively regulated the SOX4 level by sponging miR-363-3p. Furthermore, miR-363-3p inhibition or SOX4 overexpression reversed the repressing role of sh-NR2F1-AS1 in the tumorigenicity of NSCLC cells. In summary, NR2F1-AS1 promotes the tumorigenicity of NSCLC cells by regulating miR-363-3p/SOX4.

LncRNA LINC00115 facilitates lung cancer progression through miR-607/ITGB1 pathway

Dysregulated long noncoding RNAs (lncRNAs) have potential roles in various cancer types. The objective of this study was to investigate the expression and the underlying role of long intergenic nonprotein coding RNA 115 (LINC00115) in lung cancer. The relative expression of LINC00115 and miR-607 in tumor tissues and cells was detected by real-time PCR. After overexpression or knockdown of LINC00115 expression in tumor cells, the changes in the proliferation, migration, and invasion capacities were detected via Counting Kit-8 (CCK-8) assay and transwell assays. The interplay among LINC00115, miR-607, and integrin β1 (ITGB1) was confirmed by bioinformatics analyses and luciferase reporter assay. In addition, tumor cells with LINC00115 knockdown were injected into nude mice to investigate the effect of LINC00115 on tumorigenesis in vivo. LINC00115 was highly expressed in tumor tissues and cells. LINC00115 promoted the malignant properties of tumor cells. Investigation to its molecular mechanism revealed that LINC00115 functioned as a competitive endogenous RNA (ceRNA), regulating the expression of ITGB1 by sponging miR-607 to affect tumor growth. The LINC00115/miR-607/ITGB1 signaling axis might be a novel therapeutic target in lung cancer.

NR2F1-AS1/miR-190a/PHLDB2 Induces the Epithelial-Mesenchymal Transformation Process in Gastric Cancer by Promoting Phosphorylation of AKT3

The median survival time of patients with advanced gastric cancer (GC) who received radiotherapy and chemotherapy was <1 year. Epithelial–mesenchymal transformation (EMT) gives GC cells the ability to invade, which is an essential biological mechanism in the progression of GC. The long non-coding RNA (lncRNA)-based competitive endogenous RNA (ceRNA) system has been shown to play a key role in the GC-related EMT process. Although the AKT pathway is essential for EMT in GC, the relationship between AKT3 subtypes and EMT in GC is unclear. Here, we evaluated the underlying mechanism of ceRNA involving NR2F1-AS1/miR-190a/PHLDB2 in inducing EMT by promoting the expression and phosphorylation of AKT3. The results of bioinformatics analysis showed that the expression of NR2F1-AS1/miR-190a/PHLDB2 in GC was positively associated with the pathological features, staging, poor prognosis, and EMT process. We performed cell transfection, qRT-PCR, western blot, cell viability assay, TUNEL assay, Transwell assay, cell morphology observation, and double luciferase assay to confirm the regulation of NR2F1-AS1/miR-190a/PHLDB2 and its effect on EMT transformation. Finally, GSEA and GO/KEGG enrichment analysis identified that PI3K/AKT pathway was positively correlated to NR2F1-AS1/miR-190a/PHLDB2 expression. AKT3 knockout cells were co-transfected with PHLDB2-OE, and the findings revealed that AKT3 expression and phosphorylation were essential for the PHLDB2-mediated EMT process. Thus, our results showed that NR2F1-AS1/miR-190a/PHLDB2 promoted the phosphorylation of AKT3 to induce EMT in GC cells. This study provides a comprehensive understanding of the underlying mechanism involved in the EMT process as well as the identification of new EMT markers.

Circ_PIP5K1A regulates cisplatin resistance and malignant progression in non-small cell lung cancer cells and xenograft murine model via depending on miR-493-5p/ROCK1 axis

Background

Chemoresistance limits the therapeutic effect of cisplatin (DDP) on non-small cell lung cancer (NSCLC). Circular RNAs (circRNAs) function as important regulators in chemoresistance. This study aimed to explore the regulation of circRNA Phosphatidylinositol-4-Phosphate 5-Kinase Type 1 Alpha (circ_PIP5K1A) in DDP resistance.

Methods

The expression analysis of circ_PIP5K1A, micoRNA-493-5p (miR-493-5p) and Rho Associated Coiled-Coil Containing Protein Kinase 1 (ROCK1) was conducted through reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Cell sensitivity was determined using 3-(4,5-dimethylthiazol-2-y1)-2,5-diphenyl tetrazolium bromide (MTT) assay. Cell proliferation and cell viability were evaluated by colony formation assay and MTT assay, respectively. Cell cycle and apoptosis detection was performed via flow cytometry. Cell motility was examined by transwell migration or invasion assay. Dual-luciferase reporter assay was applied to confirm the target binding. ROCK1 protein level was assayed via Western blot. In vivo assay was carried out using xenograft model in mice.

Results

Circ_PIP5K1A level was abnormally increased in DDP-resistant NSCLC tissues and cells. Silencing circ_PIP5K1A reduced DDP resistance, proliferation, cell cycle progression and cell motility in DDP-resistant NSCLC cells. Circ_PIP5K1A directly interacted with miR-493-5p in NSCLC cells. The function of circ_PIP5K1A was dependent on the negative regulation of miR-493-5p. MiR-493-5p directly targeted ROCK1 and circ_PIP5K1A regulated the ROCK1 level via acting as a sponge of miR-493-5p. Overexpression of miR-493-5p inhibited chemoresistance and cancer progression by downregulating ROCK1 expression in DDP-resistant NSCLC cells. Circ_PIP5K1A regulated DDP sensitivity in vivo via the miR-493-5p/ROCK1 axis.

Conclusion

These findings suggested that circ_PIP5K1A upregulated the ROCK1 expression to promote DDP resistance and cancer progression in NSCLC by sponging miR-493-5p.

The Effect and Mechanism of lncRNA NR2F1-As1/miR-493-5p/MAP3K2 Axis in the Progression of Gastric Cancer

Background

LncRNA NR2F1-AS1 has been identified as an oncogene in some human tumors, such as breast cancer, nonsmall cell lung cancer, and esophageal squamous cell carcinoma. Nonetheless, whether NR2F1-AS1 is involved in the progression of gastric cancer (GC) remains unknown.

Methods

The expression patterns of NR2F1-AS1, MAP3K2, and miR-493-5p in GC tissues and cells were detected by RT-qPCR. The protein expression of MAP3K2 was assessed by the Western blotting assay. The MTT assay and flow cytometry were performed to measure cell proliferation and cell apoptosis in GC cells. The transwell assay was adopted to assess cell migration in GC cells. The relationship between NR2F1-AS1, MAP3K2, and miR-493-5p was verified by a dual-luciferase reporter assay.

Results

The increased NR2F1-AS1 and MAP3K2 expressions were discovered in GC tissues and cells compared with control groups. Knockdown of NR2F1-AS1 and MAP3K2 dramatically suppressed cell proliferation and migration, while it enhanced cell apoptosis in GC cells. In addition, NR2F1-AS1 was found to be a sponge of miR-493-5p, and MAP3K2 was a downstream gene of miR-493-5p. Moreover, the expression of MAP3K2 was notably reduced by miR-493-5p, and NR2F1-AS1 counteracted the inhibition of miR-493-5p.

Conclusion

Thus, NR2F1-AS1 was verified to regulate GC cell progression by sponging miR-493-5p to upregulate MAP3K2 expression.

STAT3 activates the transcription of lncRNA NR2F1-AS1 to promote the progression of melanoma via regulating the miR-493-5p/GOLM1 axis

BACKGROUND

Long non-coding RNAs (lncRNAs) are vital regulators during the biological processes of melanoma. The present study aimed to uncover biological functions of lncRNA termed NR2F1 antisense RNA 1 (NR2F1-AS1) in melanoma and the potential mechanisms.

METHODS

Relative levels of NR2F1-AS1 and miR-493-5p in a total of 137 paired primary melanoma tissues and corresponding non-tumor tissues, as well as three melanoma cell lines, were examined by a real-time polymerase chain reaction. The clinical significance of NR2F1-AS1 expression was analyzed statistically. The STAT3 binding motif in the promoter region of NR2F1-AS1 was identified by JASPAR (http://jaspar.genereg.net). The association between STAT3 and NR2F1-AS1 was determined by dual-luciferase reporter and chromatin immunoprecipitation assays. The effects of NR2F1-AS1 on cell proliferation, migration and were measured by cell counting kit-8 (CCK-8), Edu, transwell and wound healing assays. Dual-luciferase reporter and RNA pull-down assays were applied to validate the interaction among NR2F1-AS1, miR-493-5p and GOLM1. Furthermore, in vivo experiments were conducted to demonstrate the oncogenic role of NR2F1-AS1 in melanoma.

RESULTS

Up-regulated NR2F1-AS1 and down-regulated miR-493-5p were detected in melanoma tumors and cells. The overexpression of NR2F1-AS1 was induced by STAT3. High NR2F1-AS1 expression was correlated to advanced tumor stage and poor prognosis of melanoma. Functional studies using CCK-8, Edu, transwell and wound healing assays revealed that the proliferative, migratory and invasive capacities of melanoma cells were attenuated by the by inhibition of NR2F1-AS1. Moreover, NR2F1-AS1 was able to up-regulate GOLM1 through recognizing and binding miR-493-5p. Furthermore, knockdown of miR-493-5p distinctly reversed these inhibitory effects of NR2F1-AS1 down-regulation on the tumorigenesis and progression of melanoma.

CONCLUSIONS

Our findings demonstrate a key role for NR2F1-AS1 in melanoma progression via targeting miR-493-5p/GOLM1 axis.

Transcriptome Analysis of Ivosidenib-Mediated Inhibitory Functions on Non-Small Cell Lung Cancer

Ivosidenib is an isocitrate dehydrogenase mutant inhibitor that the US Food and Drug Administration recently approved for the treatment of leukemia. Studies suggested that ivosidenib may inhibit the progression of non-small cell lung cancer (NSCLC). In the present study, we explored RNAs and their potential regulatory mechanisms by which ivosidenib treats NSCLC cells. We used MTT assays, Transwell assays, and flow cytometry to measure the anti-tumor effects of ivosidenib in NSCLC cells. We performed whole transcriptome sequencing to determine differentially expressed mRNAs (DE-mRNAs) and non-coding RNAs (ncRNA). We used GO and KEGG pathway enrichment analyses to identify the functions and potential mechanisms. According to miRNA target interactions, we constructed a competing endogenous network. Ivosidenib inhibited the proliferation, invasion, and migration of NSCLC cells and inhibited tumor growth in vivo. We identified 212 DE-mRNAs, four DE-miRNAs, and 206 DE-lncRNAs in ivosidenib-treated NSCLC cells compared to untreated NSCLC cells. DE-mRNAs were significantly enriched in the cancer-associated pathways, including the TGF-β signaling pathway, the PI3K-Akt signaling pathway, the Jak-STAT signaling pathway, the MAPK signaling pathway, the Rap1 signaling pathway, and cell adhesion molecules. Based on the competing endogenous RNA hypothesis, we constructed lncRNA-miRNA-mRNA networks to elucidate the regulatory relationships between mRNA and ncRNA. We found that qRT-PCR results showed corresponding expression trends of differential genes with sequencing data. Our results provide insights into the molecular basis of ivosidenib suppression of NSCLC.

ITGB1-DT Facilitates Lung Adenocarcinoma Progression via Forming a Positive Feedback Loop With ITGB1/Wnt/β-Catenin/MYC

Lung adenocarcinoma (LUAD) is the main histological type of lung cancer, which is the leading cause of cancer-related deaths. Long non-coding RNAs (lncRNAs) were recently revealed to be involved in various cancers. However, the clinical relevance and potential biological roles of most lncRNAs in LUAD remain unclear. Here, we identified a prognosis-related lncRNA ITGB1-DT in LUAD. ITGB1-DT was upregulated in LUAD and high expression of ITGB1-DT was correlated with advanced clinical stages and poor overall survival and disease-free survival. Enhanced expression of ITGB1-DT facilitated LUAD cellular proliferation, migration, and invasion, and also lung metastasis in vivo. Knockdown of ITGB1-DT repressed LUAD cellular proliferation, migration, and invasion. ITGB1-DT interacted with EZH2, repressed the binding of EZH2 to ITGB1 promoter, reduced H3K27me3 levels at ITGB1 promoter region, and therefore activated ITGB1 expression. Through upregulating ITGB1, ITGB1-DT activated Wnt/β-catenin pathway and its downstream target MYC in LUAD. The expressions of ITGB1-DT, ITGB1, and MYC were positively correlated with each other in LUAD tissues. Intriguingly, ITGB1-DT was found as a transcriptional target of MYC. MYC directly transcriptionally activated ITGB1-DT expression. Thus, ITGB1-DT formed a positive feedback loop with ITGB1/Wnt/β-catenin/MYC. The oncogenic roles of ITGB1-DT were reversed by depletion of ITGB1 or inhibition of Wnt/β-catenin pathway. In summary, these findings revealed ITGB1-DT as a prognosis-related and oncogenic lncRNA in LUAD via activating the ITGB1-DT/ITGB1/Wnt/β-catenin/MYC positive feedback loop. These results implicated ITGB1-DT as a potential prognostic biomarker and therapeutic target for LUAD.

Long Non-Coding RNA LINC00239 Functions as a Competitive Endogenous RNA by Sponging microRNA-484 and Enhancing KLF12 Expression to Promote the Oncogenicity of Colorectal Cancer

Background

Long intergenic non-protein coding RNA 239 (LINC00239) is an oncogenic long non-coding RNA in acute myeloid leukemia. We aimed to determine LINC00239 expression in colorectal cancer (CRC) and examine the influences of LINC00239 on tumor behaviors of CRC cells. Furthermore, the mechanism underlying the actions of LINC00239 in CRC was unveiled in detail.

Materials and Methods

Quantitative real-time polymerase chain reaction was used to detect LINC00239 expression in CRC tissues and cell lines. CRC cell proliferation, apoptosis, migration, and invasion were investigated by cell counting kit-8 assays, flow cytometry, and cell migration and invasion assays, respectively. Tumor xenograft experiments were performed to evaluate the tumor growth of CRC cells in vivo. The interactions among LINC00239, microRNA-484 (miR-484), and kruppel-like factor 12 (KLF12) were analyzed by bioinformatics prediction, RNA immunoprecipitation and luciferase reporter assay.

Results

LINC00239 was upregulated in CRC tissues and cell lines. LINC00239 knockdown impaired CRC cell proliferation, migration, and invasion and promoted apoptosis in vitro. Additionally, LINC00239 deficiency inhibited CRC growth in vivo. Mechanistically, LINC00239 functioned as a competing endogenous RNA by directly sponging miR-484, thereby enhancing KLF12 expression. Rescue experiments further corroborated that miR-484 inhibition or KLF12 overexpression reversed the inhibitory actions of LINC00239 knockdown in CRC cells.

Conclusion

The LINC00239/miR-484/KLF12 pathway executed critical roles in CRC oncogenicity and may provide potential targets for CRC treatments.