Downregulation of miR-7-5p Inhibits the Tumorigenesis of Esophagus Cancer via Targeting KLF4

The function of long non-coding RNA SNHG11 and its working mechanism in triple-negative breast cancer

Triple-negative breast cancer (TNBC) seriously affects woman's health. The present work is to study the working mechanism of lncRNA SNHG11 in TNBC. The expressions of SNHG11, microRNA (miR)- 7-5p, specificity protein 2 (SP2) and mucin 1 (MUC-1) in TNBC tissues and cells were detected. SNHG11, miR-7-5p and SP2 expressions were then evaluated for TNBC cell malignant behaviors. The relationships among SNHG11, miR-7-5p and SP2 were predicted and verified. Finally, the binding of the transcription factor SP2 to MUC-1 promoter was detected. Abnormally elevated SNHG11, SP2 and MUC-1 expressions were observed in cultured TNBC cells and tumor tissues. SNHG11 knockdown in TNBC cells. Silencing SP2 weakened the promoting effect of SNHG11 on TNBC progression. SNHG11 negatively regulated miR-7-5p expression and positively regulated SP2 expression. SP2 bound to the P2 site of MUC-1 promoter, and SP2 knockdown suppressed MUC-1 expression. It was demonstrated that lncRNA SNHG11 promoted TNBC cell malignant behaviors to facilitate TNBC progression. The study is first of its kinds to unravel the potential of lncRNA SNHG11 in relation to TNBC.

LncRNA ANRIL promotes HR repair through regulating PARP1 expression by sponging miR-7-5p in lung cancer

BACKGROUND

Radiotherapy is an important treatment for lung cancer, mainly by triggering DNA double-strand breaks to induce cell death. Blocking DNA damage repair can increase the radiosensitivity of tumor cells. Recent studies have identified long noncoding RNAs as key regulators in DNA damage repair. The lncRNA ANRIL was previously shown to be involved in homologous recombination (HR) repair, but its specific mechanism has not been fully elucidated.

METHODS

The downstream interacting miRNAs of ANRIL were predicted according to miRanda software. Fluorescence quantitative PCR was used to detect the expression levels of ANRIL and candidate miRNAs. Clone formation experiment and cell viability assays detect cell viability after ionizing radiation. Apoptosis assay was used to detect the apoptosis of cells after 8 h of ionizing radiation. Western blot analysis and immunofluorescence assays verified the protein expression levels of the downstream target molecule PARP1 of miR-7-5p and key molecules in the HR pathway. Fluorescent reporter gene experiments were used to verify the interaction between ANRIL and miR-7-5p and between miR-7-5p and PARP1.

RESULTS

Bioinformatics analysis and qPCR validation suggested that miR-7-5p might be a downstream molecule of ANRIL. The expression of miR-7-5p was up-regulated after knockdown of ANRIL, and the expression of miR-7-5p was down-regulated after overexpression of ANRIL. Meanwhile, there was a negative correlation between ANRIL and miR-7-5p expression changes before and after ionizing radiation. The luciferase reporter gene assay confirmed the existence of ANRIL binding site with miR-7-5p, and found that transfection of miR-7-5p inhibitor can reduce the radiation sensitivity of ANRIL-KD cells. A downstream target molecule of miR-7-5p related to HR repair, PARP1, was screened through website prediction. Subsequently, it was confirmed by Western blot and luciferase reporter assays that miR-7-5p could down-regulate the expression of PARP1, and there was a miR-7-5p binding site on the 3'UTR of PARP1 mRNA. This suggests that ANRIL may act as a competitive endogenous RNA to bind miR-7-5p and upregulate the expression of PARP1. Western blot and immunofluorescence staining were used to detect the expression changes of HR repair factors in ANRIL-KD cells after ionizing radiation, and it was found that knockdown of ANRIL can inhibit the expression of PARP1, BRCA1 and Rad51, hinder radiation-induced HR repair, and eventually result in resensitizing ANRIL-KD cells to ionizing radiation.

CONCLUSIONS

Our findings provide evidence that ANRIL targets the miR-7-5p/PARP1 axis to exert its regulatory effect on HR repair, suggesting that altering ANRIL expression may be a promising strategy to overcome radiation resistance.

Identification of a novel necroptosis-associated miRNA signature for predicting the prognosis in head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is one of the most aggressive malignancies that have a poor prognosis. Necroptosis has been demonstrated in recent years to be a form of inflammatory cell death occurring in multicellular organism, which plays complex roles in cancer. However, the expression of necroptosis-related miRNAs and genes in HNSCC and their correlations with prognosis remain unclear. In this study, R software was used to screen differentially expressed miRNAs downloaded from The Cancer Genome Atlas. A prognostic model containing six necroptosis-related miRNAs (miR-141-3p, miR-148a-3p, miR-331-3p, miR-543, miR-425-5p, and miR-7-5p) was generated, whose risk score was validated as an independent prognostic factor for HNSCC. Target genes of the key miRNAs were obtained from TargetScan, miRDB, and miRTarBase, and 193 genes in the intersection of the three databases were defined as consensus genes. Kyoto Encyclopedia of Genes and Genomes and Gene Ontology analyses indicated that the composition of the tumor microenvironment as well as specific pathways may be closely related to necroptosis in HNSCC. Nine key genes were also obtained by the MCODE and cytoHubba plug-ins of Cytoscape: PIK3CD, NRAS, PTK2, IRS2, IRS1, PARP1, KLF4, SMAD2, and DNMT1. A prognostic model formed by the key gene was also established, which can efficiently predict the overall survival of HNSCC patients. In conclusion, necroptosis-related miRNAs and genes play important roles in tumor development and metastasis and can be used to predict the prognosis of HNSCC.

LINC02389/miR-7-5p Regulated Cisplatin Resistance of Non-Small-Cell Lung Cancer via Promoting Oxidative Stress

Background

Non-small-cell lung cancer (NSCLC) is one of the most common malignancies worldwide, and cisplatin-based chemotherapy is the main treatment for NSCLC. However, cisplatin resistance of NSCLC cells is a major challenge for NSCLC treatment.

Materials and Methods

qRT-PCR and Western blot were performed to detect the expression of LINC02389 and miR-7-5p in NSCLC tissues and cell lines. Cell counting kit-8 (CCK-8) assay and flow cytometry assay were applied to exam cell proliferation and apoptosis rate of NSCLC cells. The interaction between LINC02389 and miR-7-5p was verified by dual luciferase reporter gene assay, RNA pull-down assay, and RNA immunoprecipitation (RIP) assay. Additionally, cisplatin-resistant NSCLC cells were generated to assess the biological function of LINC02389 and miR-7-5p in cisplatin resistance of NSCLC.

Results

LINC02389 was highly expressed in NSCLC tissues and was correlated with poor prognosis of NSCLC patients. Knockdown of LINC02389 inhibited cell proliferation and promoted cell apoptosis of NSCLC, whereas miR-7-5p knockdown exerted the opposite effects. Moreover, LINC02389 negatively regulated the expression of miR-7-5p. In addition, LINC02389 was overexpressed, yet miR-7-5p was downregulated in cisplatin-resistant NSCLC cells compared with their parental cells. Moreover, oxidative stress biomarkers were overexpressed in cisplatin-resistant cells and were regulated by LINC02389. Besides, LINC02389 could reverse the inhibitory effect of cisplatin on NSCLC cells, which was partially reversed by attenuating the expression of miR-7-5p.

Conclusion

Our research firstly demonstrated that lncRNA LINC02389 acted as an oncogene to promote progression, oxidative stress, and cisplatin resistance through sponging miR-7-5p and may provide therapeutic targets for NSCLC.

Dysregulation of miR-204-5p/APLN axis affects malignant progression and cell stemness of esophageal cancer

OBJECTIVE

This study attempted to investigate the mechanism of miR-204-5p and its downstream gene in regulating bio-functions of esophageal cancer (EC).

METHODS

Bioinformatics analysis was performed to select the mature miRNAs, mRNAs, and clinical data of EC. The miRNA-mRNA regulatory axis was predicted through bioinformatics and used Dual-luciferase analysis to verify the interaction between miR-204-5p and APLN. qRT-PCR was applied to analyze expression of miR-204-5p and APLN mRNA. Western blot was utilized to detect APLN protein expression. Functional assays like CCK-8, wound healing, Transwell, and stem cell sphere formation assays were launched to confirm proliferative, migratory, invasive and stemness of cells in different treatment groups.

RESULTS

MiR-204-5p was lowly expressed while its target gene APLN was highly expressed in tumor tissues. Besides, miR-204-5p overexpression hindered proliferation, invasion, migration, and stemness of EC cells. Additionally, dual-luciferase assay verified the interaction of miR-204-5p and APLN. MiR-204-5p could downregulate APLN level and its overexpression reduced the effect of APLN on EC cell functions.

CONCLUSION

Dysregulation of miR-204-5p/APLN axis was linked with malignant progression of EC. MiR-204-5p/APLN may be an underlying candidate for the design of anticarcinogens.

MicroRNAs and Corresponding Targets in Esophageal Cancer as Shown In Vitro and In Vivo in Preclinical Models

Squamous cell carcinoma of the esophagus is associated with a dismal prognosis. Therefore, identification of new targets and implementation of new treatment modalities are issues of paramount importance. Based on a survey of the literature, we identified microRNAs conferring antitumoral activity in preclinical in vivo experiments. In the category of miRs targeting secreted factors and transmembrane receptors, four miRs were up-regulated and 10 were down-regulated compared with five out of nine in the category transcription factors, and six miRs were down-regulated in the category enzymes, including metabolic enzymes. The down-regulated miRs have targets which can be inhibited by small molecules or antibody-related entities, or re-expressed by reconstitution therapy. Up-regulated miRs have targets which can be reconstituted with small molecules or inhibited with antagomirs.

Five genes involved in circular RNA-associated competitive endogenous RNA network correlates with metastasis in papillary thyroid carcinoma

This study aimed to identify potential circular RNA (circRNA), microRNA (miRNA) and mRNA biomarkers as well as their underlying regulatory mechanisms in papillary thyroid carcinoma (PTC). Three microarray datasets from the Gene Expression Omnibus database as well as expression data and clinical phenotype from The Cancer Genome Atlas (TCGA) were downloaded, followed by differential expression, functional enrichment, protein-protein interaction (PPI), and module analyses. The support vector machine (SVM)-recursive feature elimination (RFE) algorithm was used to screen the key circRNAs. Finally, the mRNA-miRNA-circRNA regulatory network and competitive endogenous RNA (ceRNA) network were constructed. The prognostic value and clinical correlations of key mRNAs were investigated using TCGA dataset, and their expression was validated using the UALCAN database. A total of 1039 mRNAs, 18 miRNAs and 137 circRNAs were differentially expressed in patients with PTC. A total of 37 key circRNAs were obtained using the SVM-RFE algorithm, whereas 46 key mRNAs were obtained from significant modules in the PPI network. A total of 11 circRNA-miRNA pairs and 40 miRNA-mRNA pairs were predicted. Based on these interaction pairs, 46 circRNA-miRNA-mRNA regulatory pairs were integrated, of which 8 regulatory pairs in line with the ceRNA hypothesis were obtained, including two circRNAs (circ_0004053 and circ_0028198), three miRNAs (miR-199a-5p, miR-199b-5p, and miR-7-5p), and five mRNAs, namely APOA2, CCL20, LPAR5, MFGE8, and TIMP1. Survival analysis showed that LPAR5 expression was associated with patient survival. APOA2 expression showed significant differences between metastatic and non-metastatic tumors, whereas CCL20, LPAR5, MFGE8 and TIMP1 showed significant differences between metastatic and non-metastatic lymph nodes. Overall, we identified several potential targets and regulatory mechanisms involved in PTC. APOA2, CCL20, LPAR5, MFGE8, and TIMP1 may be correlated with PTC metastasis.

RETRACTED: Bone marrow mesenchymal stem cells-derived exosomal microRNA-19b-3p targets SOCS1 to facilitate progression of esophageal cancer

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. Concern was raised about the reliability of the Western blot results in Figs. 1D, 2K, 3C/F/G, 4B+H and 5B+H, which appear to have the same eyebrow shaped phenotype as many other publications tabulated here (https://docs.google.com/spreadsheets/d/149EjFXVxpwkBXYJOnOHb6RhAqT4a2llhj9LM60MBffM/edit#gid=0). The journal requested the corresponding author comment on these concerns and provide the raw data. However the authors were not able to satisfactorily fulfil this request and therefore the Editor-in-Chief decided to retract the article.