miR-593-5p inhibit cell proliferation by targeting PLK1 in non small cell lung cancer cells

A novel ferroptosis-related microRNA signature with prognostic value in osteosarcoma

The induction of ferroptosis is suggested to be a potential therapeutic strategy for cancers. MicroRNAs (miRNAs) are reported to play an important role in cell death processes. This study aims to construct and validate a risk model based on ferroptosis-related miRNAs (FR_miRNAs) to predict prognosis and identify novel therapeutic targets for osteosarcoma. Data from the Therapeutically Applicable Research to Generate Effective Treatments database are used as the training cohort. A prognostic signature based on two FR_miRNAs (miR-635 and miR-593) is developed using univariate Cox regression, least absolute shrinkage and selection operator regression, and multivariate Cox regression analyses. The area under the curve values of the prognostic signature to predict the 1-year, 2-year, 3-year, and 5-year overall survival rates in patients with osteosarcoma are 0.782, 0.781, 0.722, and 0.777, respectively, indicating a good predictive ability. Based on the risk score, patients are divided into low-risk and high-risk groups. Patients with high-risk scores are associated with poor survival. The risk level is determined to be an independent prognostic factor. A nomogram is established for predicting prognosis. The expression levels of PRNP (miR-635-related ferroptosis-related gene (FRG); P=0.024) and HILPDA (miR-593-related FRG; P=0.025) are significantly different between the low-risk and high-risk groups. All results are validated in an external cohort (GSE39040). The results of the functional assay reveal that miR-635 mimics inhibit osteosarcoma (OS) cell proliferation and migration, whereas miR-593 overexpression exerts the opposite effect. In conclusion, miR-635 and miR-593 exert contrasting regulatory effects on OS cell proliferation and migration.

Hsa_circ_0001535 inhibits the proliferation and migration of ovarian cancer by sponging miR-593-3p, upregulating PTEN expression

BACKGROUND

Hsa_circ_0001535 is involved in biological processes in various tumors. However, the biological effects and related mechanism of hsa_circ_0001535 in ovarian cancer (OC) is unclear. This work is aimed to probe the biological function and underlying mechanism of hsa_circ_0001535 in OC, especially sponged with mi-RNA, require further elucidation.

METHODS

Hsa_circ_0001535 expression in OC tissues and cell lines were examined by qRT-PCR. Hsa_circ_0001535 overexpression model was constructed by lentivirus-mediated transfection in two OC cell lines, and the biological functions of hsa_circ_0001535 were evaluated by CCK-8, transwell assay and Western blot. Dual luciferase reporter gene assay was respectively used to explore the relationship between hsa_circ_0001535 and miR-593-3p, as well as miR-593-3p and PTEN. The expression of miR-593-3p and PTEN were detected by qRT-PCR in two OC cell lines and OC tissues.

RESULTS

Hsa_circ_0001535 was down-regulated in OC tissues and cell lines. Hsa_circ_0001535 overexpression inhibited proliferation, migration and EMT marker expression in OC cells. Of interest, hsa_circ_0001535 targeted miR-593-3p and reduced its RNA level in OC cells. PTEN was a target gene of miR-593-3p, which was up-regulated by inhibiting miR-593-3p in OC cells. Furthermore, miR-593-3p mimic treatment reversed the up-regulation of PTEN by hsa_circ_0001535 overexpression in OC cells.

CONCLUSIONS

The above results showed that hsa_circ_0001535 acted as a molecular sponge for miR-593-3p to repress miR-593-3p expression, and promoted the expression of PTEN, thus inhibited proliferation and migration of OC cells. Our research provides a potential therapeutic target for ovarian cancer patients.

The mitotic spindle-related seven-gene predicts the prognosis and immune microenvironment of lung adenocarcinoma

PURPOSE

Abnormalities in the mitotic spindle have been linked to a variety of cancers. Data on their role in the onset, progression, and treatment of lung adenocarcinoma (LUAD) need to be explored.

METHODS

The data were retrieved from The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), and Molecular Signatures Database (MSigDB), for the training cohort, external validation cohort, and the hallmark mitotic spindle gene set, respectively. Mitotic spindle genes linked to LUAD prognosis were identified and intersected with differentially expressed up-regulated genes in the training cohort. Nomogram prediction models were built based on least absolute shrinkage and selection operator (LASSO) regression, univariate cox, and multivariate cox analyses. The seven-gene immunological score was examined, as well as the correlation of immune checkpoints. The DLGAP5 and KIF15 expression in BEAS-2B, A549, H1299, H1975, and PC-9 cell lines was validated with western blot (WB).

RESULTS

A total of 965 differentially expressed up-regulated genes in the training cohort intersected with 51 mitotic spindle genes associated with LUAD prognosis. Finally, the seven-gene risk score was determined and integrated with clinical characteristics to construct the nomogram model. Immune cell correlation analysis revealed a negative correlation between seven-gene expression with B cell, endothelial cell (excluding LMNB1), and T cell CD8 + (p < 0.05). However, the seven-gene expression was positively correlated with multiple immune checkpoints (p < 0.05). The expression of DLGAP5 and KIF15 were significantly higher in A549, H1299, H1975, and PC-9 cell lines than that in BEAS-2B cell line.

CONCLUSION

High expression of the seven genes is positively correlated with poor prognosis of LUAD, and these genes are promising as prospective immunotherapy targets.

Non-Coding RNA-Dependent Regulation of Mitochondrial Dynamics in Cancer Pathophysiology

Mitochondria are essential organelles which dynamically change their shape and number to adapt to various environmental signals in diverse physio-pathological contexts. Mitochondrial dynamics refers to the delicate balance between mitochondrial fission (or fragmentation) and fusion, that plays a pivotal role in maintaining mitochondrial homeostasis and quality control, impinging on other mitochondrial processes such as metabolism, apoptosis, mitophagy, and autophagy. In this review, we will discuss how dysregulated mitochondrial dynamics can affect different cancer hallmarks, significantly impacting tumor growth, survival, invasion, and chemoresistance. Special emphasis will be given to emerging non-coding RNA molecules targeting the main fusion/fission effectors, acting as novel relevant upstream regulators of the mitochondrial dynamics rheostat in a wide range of tumors.

Transcription factor ZEB1 regulates PLK1-mediated SKA3 phosphorylation to promote lung cancer cell proliferation, migration and cell cycle

Lung cancer (LC) is one of the most common malignancies worldwide with low 5-year survival rate. The mechanism of spindle and kinetochore-associated complex subunit 3 (SKA3) in LC tumorgenesis remains largely unclear. The expression of SKA3 in LC cells was detected by quantitative PCR. Cell proliferation, migration and cell cycle were evaluated by functional assays including 5-ethynyl-2'-deoxyuridine, wound healing, transwell assays and flow cytometry analysis. Bioinformatics analysis, chromatin immunoprecipitation, luciferase reporter, co-immunoprecipitation and in vitro phosphorylation assays were applied to explore the interactions between zinc finger E-box binding homeobox 1 (ZEB1) and SKA3/polo-like kinase 1 (PLK1). SKA3 is highly expressed in LC cell lines and drives LC cell proliferation, migration and cell cycle. PLK1 also enhances the malignancy of LC cells. PLK1 can mediate SKA3 phosphorylation and enhance the stability of SKA3 protein, thus promoting LC progression. Besides, we found that transcription factor ZEB1 transcriptionally activates SKA3/PLK1 expression, contributing to LC cell malignancy. This study demonstrated that transcription factor ZEB1 modulates PLK1-mediated SKA3 phosphorylation to accelerate LC cell growth, migration and cycle, which might offer novel insight into LC treatment.

[miR-20a-5p inhibits proliferation of lung cancer A549 cells by down-regulating HOXB13]

OBJECTIVE

To investigate the molecular mechanism by which miR-20a-5p regulates HOXB13 gene expression and inhibits lung cancer cell proliferation.

METHODS

The expression levels of HOXB13 mRNA and protein in lung cancer A549 cells transfected with HOXB13 overexpression plasmid or HOXB13 siRNA were detected with real-time fluorescence quantitative PCR (qRT-PCR) and Western blotting. CCK-8 and EdU assays were used to examine the effect of modulation of HOXB13 expression on cell proliferation. We screened possible binding miRNAs of HOXB13 by bioinformatics analysis. In A549 cells transfected with miR-20a-5p mimic or miR-20a-5p inhibitor, the expression level of miR-20a-5p was detected by qRT-PCR and the protein expression of HOXB13 was determined with Western blotting. CCK-8 and EdU assays were used to assess the effect of miR-20a-5p overexpression on the proliferation of A549 cells. miR-20a-5p mimic and HOXB13 overexpression plasmids were co-transfected into A549 cells, and the changes in cell proliferation were evaluated with CCK-8 and EdU assays.

RESULTS

HOXB13 overexpression obviously promoted the proliferation of A549 cells (P < 0.05). miR-20a-5p was identified as the potential binding miRNA of HOXB13. Overexpression of miR-20a-5p in A549 cells significantly decreased the expression of HOXB13 protein (P < 0.05), while interference of miR-20a-5p obviously increased HOXB13 expression (P < 0.05). The results of cell proliferation experiment showed that miR-20a-5p and HOXB13 had opposite effects on cell proliferation, and the cells overexpressing both miR-20a-5p and HOXB13 showed a lower proliferation activity than the cells overexpressing HOXB13 but higher than the cells overexpressing miR-20a-5p alone (P < 0.05).

CONCLUSION

miR-20a-5p inhibits proliferation of lung cancer cells by down-regulating the expression of HOXB13.

miR-200a-3p promoted cell proliferation and metastasis by downregulating SOX17 in non-small cell lung cancer cells

Lung cancer has high mortality and incidence rates in which non-small cell lung cancer (NSCLC) is the primary type of lung cancer that accounts for about 80%-85% of total patients. It has been demonstrated that microRNAs (miRNAs) are critical in the incidence and progression of tumors, while the role and inner mechanism of miR-200a-3p, one type of essential miRNAs, in NSCLC have yet to be revealed. Herein, we investigated the in vitro and vivo pro-/antiproliferative influence of miR-200a-3p on NSCLC cells and utilized bioinformatic programs to further predict the SOX17 gene as miR-200a-3p's potential target. A double luciferase reporter gene experiment was performed to confirm that miR-200a-3p interacts with the SOX17 3'-UTR region specifically. On the basis of the results of Western blot and quantitative reverse-transcription polymerase chain reaction (qRT-PCR), miR-200a-3p impacted the posttranscriptional levels of SOX17 rather than influencing its mRNA expression. In the end, we found that overexpressed SOX17 can reverse miR-200a-3p's impact on NSCLC cell proliferation and metastasis. Therefore, this study demonstrated that miR-200a-3p influences NSCLC cell proliferation and metastasis by modulating the levels of SOX17.

MiR-769-5p, Which Targets HDGF, Inhibits Cell Proliferation and Invasion in Nonsmall Cell Lung Cancer

MiR-769-5p regulates tumor correlative genes, which plays a critical role in the progression of various types of tumor. However, the precise regulatory mechanism of miR-769-5p on nonsmall cell lung cancer (NSCLC) is unknown. This study was to discover the role and underlying mechanisms of miR-769-5p in NSCLC. MiR-769-5p expression was shown to be reduced, according to our findings. MiR-769-5p overexpression inhibited NSCLC cell proliferation while promoting NSCLC cell apoptosis. Furthermore, NSCLC cell migration and invasion were reduced when miR-769-5p was overexpressed. Furthermore, HDGF was confirmed as a miR-769-5p target gene that was negatively regulated by miR-769-5p. Furthermore, more research revealed that HDGF overexpression reduced the inhibitory effect of miR-769-5p on NSCLC cell biofunction. Finally, miR-769-5p inhibited NSCLC cell proliferation and invasion by targeting HDGF, indicating that NSCLC could benefit from miR-769-5p as a diagnostic and prognostic biomarker.

Circular RNA cerebellar degeneration-related protein 1 antisense RNA (Circ-CDR1as) downregulation induced by dexmedetomidine treatment protects hippocampal neurons against hypoxia/reoxygenation injury through the microRNA-28-3p (miR-28-3p)/tumor necrosis factor receptor-associated factor-3 (TRAF3) axis

Cerebral ischemia/reperfusion (CI/R) injury results in serious brain tissue damage, thereby leading to long-term disability and mortality. It has been reported that dexmedetomidine (DEX) exerted neuroprotective effects in CI/R injury. Herein, we intended to investigate whether and how circular RNA (circRNA) cerebellar degeneration-related protein 1 antisense RNA (circ-CDR1as) was involved in the DEX-mediated protection on hippocampal neurons. In our work, the mouse hippocampal neuronal cells (HT-22) were used to construct a hypoxia/reperfusion (H/R) model for CI/R injury. Cell proliferation and apoptosis were evaluated by CCK-8 and flow cytometry. Gene expressions were detected by RT-qPCR. Levels of pro-inflammatory cytokines (TNF-α, IL-6, and IL-1β) were measured by ELISA. The association between miR-28-3p and circ-CDR1as or TRAF3 was verified by dual-luciferase assay. The results indicated that DEX alleviated HT-22 cell dysfunction induced by H/R treatment. In addition, circ-CDR1as was downregulated after DEX treatment and reversed the effects of DEX on the proliferation, apoptosis, and inflammatory responses of H/R-treated HT-22 cells. Circ-CDR1as positively regulated TRAF3 expression via interaction with miR-28-3p in HT-22 cells. Circ-CDR1as aggravated H/R-treated HT-22 cell dysfunction through targeting miR-28-3p. Furthermore, TRAF3 inhibition partly abolished the effect of circ-CDR1as overexpression on cellular activities of H/R-treated HT-22 cells. To sum up, our findings, for the first time, demonstrated that DEX exerted neuroprotective effects on hippocampal neurons against H/R treatment via the circ-CDR1as/miR-28-3p/TRAF3 regulatory network, providing novel therapeutic targets for DEX administration in CI/R treatment.

Dendrimer-modified gold nanorods as a platform for combinational gene therapy and photothermal therapy of tumors

Background

The exploitation of novel nanomaterials combining diagnostic and therapeutic functionalities within one single nanoplatform is challenging for tumor theranostics.

Methods

We synthesized dendrimer-modified gold nanorods for combinational gene therapy and photothermal therapy (PTT) of colon cancer. Poly(amidoamine) dendrimers (PAMAM, G3) grafted gold nanorods were modified with GX1 peptide (a cyclic 7-mer peptide, CGNSNPKSC). The obtained Au NR@PAMAM-GX1 are proposed as a gene delivery vector to gene (FAM172A, regulates the proliferation and apoptosis of colon cancer cells) for the combination of photothermal therapy (PTT) and gene therapy of Colon cancer cells (HCT-8 cells). In addition, the CT imaging function of Au NR can provide imaging evidence for the diagnosis of colon cancer.

Results

The results display that Au NR@PAMAM-GX1 can specifically deliver FAM172A to cancer cells with excellent transfection efficiency. The HCT-8 cells treated with the Au NR@PAMAM-GX1/FAM172A under laser irradiation have a viability of 20.45%, which is much lower than the survival rate of other single-mode PTT treatment or single-mode gene therapy. Furthermore, animal experiment results confirm that Au NR@PAMAM-GX1/FAM172A complexes can achieve tumor thermal imaging, targeted CT imaging, PTT and gene therapy after tail vein injection.

Conclusion

Our findings demonstrate that the synthesized Au NR@PAMAM-GX1 offer a facile platform to exert antitumor and improve the diagnostic level of tumor.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-02105-3.

Knockdown of lncRNA PVT1 inhibits the proliferation and accelerates the apoptosis of colorectal cancer cells via the miR‑761/MAPK1 axis

Colorectal cancer (CRC) is associated with high morbidity rates. Long non‑coding RNAs (lncRNAs) participate in the development of CRC. However, the potential roles of lncRNA plasmacytoma variant translocation 1 (PVT1) in CRC remain unknown. Therefore, the aim of the present study was to investigate the potential roles of PVT1 in CRC. Reverse transcription‑quantitative PCR and western blot analyses were conducted to determine the mRNA and protein expression levels. The cellular behaviors were detected using 5‑Ethynyl‑2'‑deoxyuridine, Cell Counting Kit‑8 and flow cytometry assays. The interaction between PVT1 and microRNA (miR)‑761 or MAPK1 was confirmed using a dual‑luciferase reporter assay. Moreover, the Pearson's method was applied for correlation analysis. The results demonstrated that the expression levels of PVT1 and MAPK1 were upregulated, while miR‑761 was downregulated in CRC tissues. The expression of PVT1 was positively correlated with MAPK1 and negatively correlated with miR‑761. In addition, PVT1 sponged miR‑761 to upregulate MAPK1 expression. It was found that the knockdown of PVT1 expression inhibited the proliferation and promoted the apoptosis of CRC cells, which was more potent in cells transfected with miR‑761. The regulatory role of small interfering RNA‑PVT1 on the expression of apoptosis‑related genes was reduced by MAPK1. Collectively, the present results suggested that knockdown of PVT1 may inhibit the progression of CRC by regulating the miR‑761/MAPK1 axis, which may provide a promising biomarker for the treatment of CRC.

Evaluation of the roles and regulatory mechanisms of PD-1 target molecules in NSCLC progression

Background

Targeted programmed cell death protein 1 (PD-1) therapy could effectively improve the long-term prognosis of patients with non-small cell lung cancer (NSCLC). The role of PD-1 targets in the progression of NSCLC has not been fully revealed.

Methods

The differentially expressed genes (DEGs) in patients’ blood after NSCLC treatment with PD-1 blocker nivolumab in the GSE141479 dataset were analyzed by GEO2R and identified in the TCGA database. The mechanism of action involved in the PD-1 target molecules via the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). The protein-protein interaction (PPI) network shows the relationship between PD-1 target molecules. The factors affecting the prognosis of NSCLC patients were identified via the COX regression analysis and survival analysis to build the risk model and nomogram.

Results

There were 64 DEGs in patients’ blood after nivolumab treatment and 48 DEGs in NSCLC tissues. The PD-1 target molecules involved cell proliferation, DNA replication, cell cycle, lung cancer, and other cellular processes. The prognostic factors CCNA2, CHEK1, DLGAP5, E2F8, FOXM1, HIST1H2BH, HJURP, MKI67, PLK1, TPX2, and TYMS, and the independent factors HIST1H2BH and PLK1, influenced the prognosis of NSCLC patients. HIST1H2BH and PLK1 were overexpressed in LUAD and LUSC tissues. The elevated expression levels of HIST1H2BH and PLK1 were related to the overall survival (OS) and the progression-free survival of NSCLC patients. High-risk NSCLC patients had a poor prognosis and were an independent factor influencing the poor prognosis of NSCLC patients. The high-risk model group was enriched with signaling mechanisms such as cell cycle, DNA replication, and homologous recombination.

Conclusions

The risk model based on PD-1 target molecules was helpful to assess the prognosis of NSCLC patients. HIST1H2BH and PLK1 might become prognostic biomarkers of NSCLC patients.

Bioinformatics analysis of key genes in triple negative breast cancer and validation of oncogene PLK1

Background

Breast cancer is the most common malignancy in women. Triple-negative breast cancer (TNBC) refers to a special subtype that is deficient in the expression of estrogen (ER), progesterone (PR), and human epidermal growth factor receptor 2 (HER-2). In this study, a variety of bioinformatics analysis tools were used to screen Hub genes related to the occurrence and development of triple negative breast cancer, and their biological functions were analyzed.

Methods

Gene Expression Omnibus (GEO) breast cancer microarray data GSE62931 was selected as the research object. The differentially expressed genes (DEGs) were screened and the protein-protein interaction (PPI) network of DEGs was constructed using bioinformatics tools. The Hub genes were also screened. The Gene Ontology (GO) knowledgebase and the Kyoto Encyclopedia of Genes and Genomes (KEGG) were used for biological enrichment analysis. The Gene Expression Profiling Interactive Analysis (GEPIA) online tool was used to verify the expression of the screened genes and patient survival. The effects of polo-like kinase 1 (PLK1) on the proliferation, invasion, migration, and dryness of breast cancer cells were verified using cell counting kit 8 (CCK-8), transwell migration assays, scratch tests, and clone formation tests. An animal model of subcutaneous xenotransplantation of breast cancer was established to evaluate the effect of PLK1 on the proliferation of breast cancer.

Results

A total of 824 DEGs were screened by GSE62931 microarray data; 405 of which were up-regulated and 419 of which were down-regulated. Functional enrichment analysis showed that these DEGs were mainly enriched in cancer-related pathways and were primarily involved in biological processes (BP) such as cell and mitotic division. From the Hub gene screening, PLK1 was further identified as the Hub gene associated with TNBC. Cell and animal experiments indicated that PLK1 promotes the proliferation, invasion, migration, and clone formation of breast cancer cells.

Conclusions

Gene chip combined with bioinformatics methods can effectively analyze the DEGs related to the occurrence and development of breast cancer, and the screening of PLK1 can provide theoretical guidance for further research on the molecular mechanism of breast cancer and the screening of molecular markers.

Silencing of miR-23a attenuates hydrogen peroxide (H2O2) induced oxidative damages in ARPE-19 cells by upregulating GLS1: an in vitro study

BACKGROUND

Oxidative damages contributes to age-related macular degeneration (AMD) caused vision blindness, but the molecular mechanisms are still largely unknown.

OBJECTIVES

This study managed to investigate this issue by conducting in vitro experiments.

METHODS

Oxidative stress were evaluated by L-012 dye, DHE staining and MDA assay. CCK-8 and colony formation assay were conducted to examine cell proliferation. Cell death was evaluated by trypan blue staining and Annexin V-FITC/PI double staining method through flow cytometry (FCM). The binding sites of miR-23a and GLS1 mRNA were predicted by online miRDB database and validated by dual-luciferase reporter gene system. Real-Time qPCR for miR-23a levels and Western Blot for protein expressions.

RESULTS

The retinal pigment epithelial (RPE) cells (ARPE-19) were subjected to hydrogen peroxide (H2O2) stimulation to simulate AMD progression in vitro, and we identified a novel miR-23a/glutaminase-1 (GLS1) pathway that regulated H2O2 induced oxidative damages in ARPE-19 cells. Mechanistically, H2O2 induced oxidative stress, inhibited cell proliferation and induced cell death in ARPE-19 cells in a dose- and time-dependent manner. Also, H2O2 stimulation hindered cell invasion, migration and glutamine uptake in ARPE-19 cells. Interestingly, we proved that H2O2 increased miR-23a levels, while downregulated glutaminase-1 (GLS1) in ARPE-19 cells, and miR-23a targeted 3' untranslated region (3'UTR) of GLS1 mRNA for GLS1 degradation. Finally, our data suggested that silencing miR-23a upregulated GLS1 to reverse the detrimental effects of H2O2 treatment on ARPE-19 cells.

CONCLUSIONS

In general, analysis of the data suggested that miR-23a ablation upregulated GLS1 to attenuate H2O2 stimulation induced oxidative damages in ARPE-19 cells in vitro, and this study broadened our knowledge in this field, which might help to provide novel theranostic signatures for AMD.

Progress in Delivery of siRNA-Based Therapeutics Employing Nano-Vehicles for Treatment of Prostate Cancer

Prostate cancer (PCa) accounts for a high number of deaths in males with no available curative treatments. Patients with PCa are commonly diagnosed in advanced stages due to the lack of symptoms in the early stages. Recently, the research focus was directed toward gene editing in cancer therapy. Small interfering RNA (siRNA) intervention is considered as a powerful tool for gene silencing (knockdown), enabling the suppression of oncogene factors in cancer. This strategy is applied to the treatment of various cancers including PCa. The siRNA can inhibit proliferation and invasion of PCa cells and is able to promote the anti-tumor activity of chemotherapeutic agents. However, the off-target effects of siRNA therapy remarkably reduce its efficacy in PCa therapy. To date, various carriers were designed to improve the delivery of siRNA and, among them, nanoparticles are of importance. Nanoparticles enable the targeted delivery of siRNAs and enhance their potential in the downregulation of target genes of interest. Additionally, nanoparticles can provide a platform for the co-delivery of siRNAs and anti-tumor drugs, resulting in decreased growth and migration of PCa cells. The efficacy, specificity, and delivery of siRNAs are comprehensively discussed in this review to direct further studies toward using siRNAs and their nanoscale-delivery systems in PCa therapy and perhaps other cancer types.

Long noncoding RNA CBR3 antisense RNA 1 promotes the aggressive phenotypes of non‑small‑cell lung cancer by sponging microRNA‑509‑3p and competitively upregulating HDAC9 expression

Long noncoding RNA CBR3 antisense RNA 1 (CBR3‑AS1) plays significant roles in the initiation and progression of osteosarcoma. The aim of the present study was to investigate the involvement of CBR3‑AS1 in the development of non‑small cell lung cancer (NSCLC). Reverse transcription‑quantitative PCR was performed to detect CBR3‑AS1 expression in NSCLC tissues and cell lines. The impacts of CBR3‑AS1 on cellular proliferation, apoptosis, migration and invasiveness in vitro, and tumor growth in vivo, were investigated using the Cell Counting Kit‑8 assay, flow cytometry, Transwell migration and invasion assays, and tumor xenograft model‑based analysis, respectively. The results indicated that CBR3‑AS1 was markedly upregulated in NSCLC tissues and cell lines. High CBR3‑AS1 expression was correlated with larger tumor size, advanced TNM stage, increased incidence of lymph node metastasis and shorter overall survival times in patients with NSCLC. Furthermore, CBR3‑AS1‑knockdown notably suppressed cellular proliferation, migration and invasiveness in vitro, and also promoted apoptosis and suppressed tumorigenicity in vivo. Mechanistic investigation demonstrated that CBR3‑AS1 functions as a competing endogenous RNA for microRNA‑509‑3p (miR‑509‑3p) in NSCLC cells. Furthermore, miR‑509‑3p exerted tumor‑suppressive effects in NSCLC, and histone deacetylase 9 (HDAC9) was identified as a direct target of miR‑509‑3p. HDAC9 expression was suppressed by CBR3‑AS1 depletion, which was abolished by miR‑509‑3p inhibition. Further rescue experiments revealed that increasing the output of the miR‑509‑3p/HDAC9 axis counteracted the CBR3‑AS1 depletion‑induced inhibitory effects on NSCLC cells. Collectively, the results of the present study indicate that the CBR3‑AS1/miR‑509‑3p/HDAC9 pathway exerts tumor‑promoting actions in NSCLC oncogenesis and progression, suggesting that this pathway is an effective target for the management of NSCLC.

Circular RNA circ_0000284 plays an oncogenic role in the progression of non-small cell lung cancer through the miR-377-3p-mediated PD-L1 promotion

Background

Circular RNAs (circRNAs), a subgroup of non-coding RNAs, are recognized as pivotal mediators in various types of cancers. CircRNA_0000284 (circ_0000284) was manifested to participate in the development of non-small cell lung cancer (NSCLC). The novel functional mechanism of circ_0000284 in NSCLC was investigated in our current study.

Methods

We exploited quantitative real-time polymerase chain reaction (qRT-PCR) to analyze the relative RNA (circRNA, miRNA and mRNA) expression. The assessment of cell proliferation and colony formation was executed by Cell Counting Kit-8 (CCK-8) and colony formation assay, respectively. Transwell assay was implemented to examine cell migration and invasion. All protein levels were assayed using western blot. The role of circ_0000284 in vivo was evaluated via xenograft model. The target relation was estimated by dual-luciferase reporter and RNA immunoprecipitation (RIP) assays.

Results

As for the biological characterization, circ_0000284 was highly stable and localized in the cytoplasm. Circ_0000284 was up-regulated in NSCLC and could predict poor prognosis of NSCLC patients. Both in vitro and in vivo, down-regulation of circ_0000284 refrained tumorigenesis of NSCLC. Besides, microRNA-377-3p (miR-377-3p) was a miRNA target of circ_0000284, and targeted programmed death-ligand 1 (PD-L1). Circ_0000284 was a cancer-promoting circRNA in NSCLC via regulating the miR-377-3p/PD-L1 axis.

Conclusion

Thus, our results unraveled that circ_0000284 facilitated the progression of NSCLC by up-regulating the PD-L1 expression as a competing endogenous RNA (ceRNA) of miR-377, possibly developing a different perspective in understanding the molecular pathogenesis of NSCLC.