LINC00472 Acts as a Tumor Suppressor in NSCLC through KLLN-Mediated p53-Signaling Pathway via MicroRNA-149-3p and MicroRNA-4270

Building endoplasmic reticulum stress-related LncRNAs signatures of lung adenocarcinoma

BACKGROUND

Endoplasmic reticulum stress (ERS) could be a strategy for treating malignant tumors. Moreover, long noncoding RNAs (lncRNAs) can promote tumorigenesis and progression, and forecast the prognosis of cancers. Nevertheless, the prognostic value of ERS-related lncRNAs has not been reported in lung adenocarcinoma (LUAD).

METHODS

The messenger RNA (mRNA), microRNA (miRNA) and lncRNA expression data related to LUAD were obtained in public databases (TCGA and GEO databases). Prognostic ERS-related differentially expressed lncRNAs (ERS-DELs) were obtained and used to build an ERS-related model by Cox regression analysis. Moreover, we further screened independent prognostic elements and built a nomogram. Furthermore, enrichment analysis of genes was conducted to investigate the functions. A lncRNA-miRNA-mRNA network was built to explore mechanism of lncRNAs. Finally, qRT-PCR was utilized to examine the expression levels of lncRNAs.

RESULTS

30 ERS-DELs were identified, and an ERS-related signature was built based on AF131215.2, LINC00472, LINC01352, RP1-78O14.1, RP11-253E3.3, RP11-98D18.9, and SNHG12. Gene set enrichment analysis indicated that genes in the high-risk group were chiefly focused on the regulation of mRNA binding, and genes in the low-risk group were significantly focused on protein localization to cilia. A lncRNA-miRNA-mRNA network, containing 7 signature lncRNAs, 23 miRNAs, and 128 mRNAs, was also established. Eventually, quantitative real-time polymerase chain reaction was used to confirm that seven prognostic lncRNAs had a consistent expression with the analysis.

CONCLUSIONS

An ERS-related signature containing seven prognostic lncRNAs was built, which offered new thinking concerning the role of ERS-related lncRNAs in LUAD.

The prognostic, diagnostic, and therapeutic impact of Long noncoding RNAs in gastric cancer

Gastric cancer (GC), ranking as the third deadliest cancer globally, faces challenges of late diagnosis and limited treatment efficacy. Long non-coding RNAs (lncRNAs) emerge as valuable treasured targets for cancer prognosis, diagnosis, and therapy, given their high specificity, convenient non-invasive detection in body fluids, and crucial roles in diverse physiological and pathological processes. Research indicates the significant involvement of lncRNAs in various aspects of GC pathogenesis, including initiation, metastasis, and recurrence, underscoring their potential as novel diagnostic and prognostic biomarkers, as well as therapeutic targets for GC. Despite existing challenges in the clinical application of lncRNAs in GC, the evolving landscape of lncRNA molecular biology holds promise for advancing the survival and treatment outcomes of gastric cancer patients. This review provides insights into recent studies on lncRNAs in gastric cancer, elucidating their molecular mechanisms and exploring the potential clinical applications in GC.

miR-4270 suppresses hepatocellular carcinoma progression by inhibiting DNMT3A-mediated methylation of HGFAC promoter

Background

miR-4270 is a regulatory factor has been linked with the progression of various cancers, such as nasopharyngeal carcinoma, hepatocellular carcinoma (HCC), and gastric cancer. However, the underlying mechanisms through which miR-4270 modulates HCC development are not fully understood.

Methods

miR-4270 expression levels were analyzed in various HCC cell lines and tissue samples. An online bioinformatics tool was then utilized to predict the miR-4270 target gene. The binding relationship between miR-4270 and its target gene DNMT3A was verified using dual-luciferase reporter and Ago2-RIP assays. Then, co-immunoprecipitation (Co-IP) and chromatin immunoprecipitation (ChIP) assays were conducted to investigate the association between DNMT3A and the hepatocyte growth factor activator (HGFAC) promoter region. To assess the methylation level of the HGFAC promoter, methylation-specific PCR (MSP) was employed. Furthermore, rescue analyses were carried out to evaluate the functional relevance of miR-4270 and HGFAC in the modulation of the malignant properties of HCC cells. Finally, HepG2 cells overexpressing miR-4270 were subcutaneously injected into nude mice to estimate the impact of miR-4270 on the xenograft tumor growth of HCC.

Results

A substantial miR-4270 downregulation was revealed in HCC patient samples and cell lines. miR-4270 upregulation suppressed both cell proliferation and invasion while promoting apoptosis. At the molecular level, miR-4270 was found to bind to the 3'untranslated region (3'UTR) of DNMT3A, thereby inhibiting DNMT3A-mediated methylation of the HGFAC promoter. Functional assays indicated that inhibition of miR-4270 stimulated HCC cell growth, an effect counteracted by overexpression of HGFAC. In vivo assays further verified that miR-4270 effectively suppressed the progression of HCC xenograft tumors.

Conclusions

miR-4270 was found to mitigate the malignant characteristics of HCC by inhibiting DNMT3A-mediated methylation of the HGFAC promoter, suggesting a potential therapeutic avenue for the management of HCC.

Roles of miR-4442 in Colorectal Cancer: Predicting Early Recurrence and Regulating Epithelial-Mesenchymal Transition

Early recurrence in patients with colorectal cancer (CRC) is associated with a poor prognosis. We aimed to identify circulating microRNAs that are biomarkers of early CRC recurrence and elucidate their functions. We identified miR-4442 as a candidate biomarker by microRNA array analysis comparing preoperative and postoperative plasma levels in patients with CRC, with and without recurrence. The association between preoperative plasma miR-4442 levels, clinicopathological features, and recurrence-free survival was analyzed in 108 patients with CRC after curative surgery. Furthermore, cell-function analyses were performed, and the involvement of miR-4442 in regulating epithelial-mesenchymal transition (EMT) was examined. Preoperatively plasma miR-4442 levels were associated with CRC recurrence and exhibited an incremental increase with earlier recurrence dates. Moreover, miR-4442 demonstrated high sensitivity and specificity as a potential biomarker for early CRC recurrence. The expression of miR-4442 in cancer tissues of patients with metastatic liver cancer from CRC was higher than in normal liver, CRC, and normal colorectal tissues. The overexpression of miR-4442 promoted the proliferative, migratory, and invasive activities of CRC cells, decreased levels of RBMS1 and E-cadherin, and increased levels of N-cadherin and Snail1. Plasma miR-4442 is a clinically useful biomarker for predicting the early recurrence of CRC. Furthermore, miR-4442 regulates EMT in CRC by directly targeting the messenger RNA of RBMS1.

Effect of miR-4270 Suppression on Migration in Hepatocellular Carcinoma Cell Line (HepG2)

Background

Liver transplantation and surgical resection are two major strategies for treatment of hepatocellular carcinoma (HCC) patients. One approach to treating HCC is the suppression of metastasis to other tissues. Herein, we aimed to study the effect of miR-4270 inhibitor on migration of HepG2 cells as well as activity of matrix metalloproteinase (MMP) these cells in order to find a strategy to suppress metastasis in future.

Methods

HepG2 cells were treated with 0, 10, 20, 30, 40, 50, 60, 70, 80, and 90 nM of miR-4270 inhibitor, and then the cell viability was measured by trypan blue staining. Afterwards, cell migration and MMP activity of HepG2 cells were assessed by wound healing assay and zymography, respectively. The MMP gene expression was determined by real-time reverse transcription polymerase chain reaction.

Results

Results showed that miR-4270 inhibitor decreased the cell viability of HepG2 cells in a concentration-dependent manner. Also, inhibition of the miR-4270 reduced invasion, MMP activity, and expression of MMP genes in HepG2 cells, respectively.

Conclusion

Our findings suggest that miR-4270 inhibitor decreases in vitro migration, which could help find a new approach for HCC therapy patients.

Effect of miR-4270 Suppression on Migration in Hepatocellular Carcinoma Cell Line (HepG2)

Background

Liver transplantation and surgical resection are two major strategies for treatment of hepatocellular carcinoma (HCC) patients. One approach to treating HCC is the suppression of metastasis to other tissues. Herein, we aimed to study the effect of miR-4270 inhibitor on migration of HepG2 cells as well as activity of matrix metalloproteinase (MMP) these cells in order to find a strategy to suppress metastasis in future.

Methods

HepG2 cells were treated with 0, 10, 20, 30, 40, 50, 60, 70, 80, and 90 nM of miR-4270 inhibitor, and then the cell viability was measured by trypan blue staining. Afterwards, cell migration and MMP activity of HepG2 cells were assessed by wound healing assay and zymography, respectively. The MMP gene expression was determined by real-time reverse transcription polymerase chain reaction.

Results

Results showed that miR-4270 inhibitor decreased the cell viability of HepG2 cells in a concentration-dependent manner. Also, inhibition of the miR-4270 reduced invasion, MMP activity, and expression of MMP genes in HepG2 cells, respectively.

Conclusion

Our findings suggest that miR-4270 inhibitor decreases in vitro migration, which could help find a new approach for HCC therapy patients.

DDX17 induces epithelial-mesenchymal transition and metastasis through the miR-149-3p/CYBRD1 pathway in colorectal cancer

DEAD box helicase 17 (DDX17) has been reported to be involved in the initiation and development of several cancers. However, the functional role and mechanisms of DDX17 in colorectal cancer (CRC) malignant progression and metastasis remain unclear. Here, we reported that DDX17 expression was increased in CRC tissues compared with noncancerous mucosa tissues and further upregulated in CRC liver metastasis compared with patient-paired primary tumors. High levels of DDX17 were significantly correlated with aggressive phenotypes and worse clinical outcomes in CRC patients. Ectopic expression of DDX17 promoted cell migration and invasion in vitro and in vivo, while the opposite results were obtained in DDX17-deficient CRC cells. We identified miR-149-3p as a potential downstream miRNA of DDX17 through RNA sequencing analysis, and miR-149-3p displayed a suppressive effect on the metastatic potential of CRC cells. We demonstrated that CYBRD1 (a ferric reductase that contributes to dietary iron absorption) was a direct target of miR-149-3p and that miR-149-3p was required for DDX17-mediated regulation of CYBRD1 expression. Moreover, DDX17 contributed to the metastasis and epithelial to mesenchymal transition (EMT) of CRC cells via downregulation of miR-149-3p, which resulted in increased CYBRD1 expression. In conclusion, our findings not only highlight the significance of DDX17 in the aggressive development and prognosis of CRC patients, but also reveal a novel mechanism underlying DDX17-mediated CRC cell metastasis and EMT progression through manipulation of the miR-149-3p/CYBRD1 pathway.

Lung Cancer Subtype Diagnosis by Fusing Image-Genomics Data and Hybrid Deep Networks

Accurate diagnosis of cancer subtypes is crucial for precise treatment, because different cancer subtypes are involved with different pathology and require different therapies. Although deep learning techniques have made great success in computer vision and other fields, they do not work well on Lung cancer subtype diagnosis, due to the distinction of slide images between different cancer subtypes is ambiguous. Furthermore, they often over-fit to high-dimensional genomics data with limited samples, and do not fuse the image and genomics data in a sensible way. In this paper, we propose a hybrid deep network based approach LungDIG for Lung cancer subtype Diagnosis by fusing Image-Genomics data. LungDIG first tiles the tissue slide image into small patches and extracts the patch-level features by fine-tuning an Inception-V3 model. Since the patches may contain some false positives in non-diagnostic regions, it further designs a patch-level feature combination strategy to integrate the extracted patch features and maintain the diversity between different cancer subtypes. At the same time, it extracts the genomics features from Copy Number Variation data by an attention based nonlinear extractor. Next, it fuses the image and genomics features by an attention based multilayer perceptron (MLP) to diagnose cancer subtype. Experiments on TCGA lung cancer data show that LungDIG can not only achieve higher accuracy for cancer subtype diagnosis than state-of-the-art methods, but also have a high authenticity and good interpretability.

LncRNA SEMA3B-AS1 inhibits breast cancer progression by targeting miR-3940/KLLN axis

Long noncoding RNAs (lncRNAs) play crucial regulatory roles in the progression of various cancers. However, the functional roles of lncRNAs in breast cancer remain unclear. In this study, we investigated the functional role of a novel long noncoding RNA SEMA3B-AS1 (lncRNA SEAS1) in breast cancer progression and the underlying mechanisms. SEAS1 was downregulated in the triple-negative breast cancer (TNBC) tissues compared with the para-carcinoma tissues, which was associated with poor prognosis of TNBC patients. We demonstrated that SEAS1 knockdown significantly increased the proliferation, migration, and invasion of TNBC cell lines, whereas SEAS1 overexpression reversed these effects. Bioinformatics analysis demonstrated that microRNA (miR)-3940-3p was a potential target of SEAS1. Mechanistically, RNA immunoprecipitation (RIP) and luciferase reporter assays confirmed that lncRNA SEMA3B-AS1 acted as sponge for miR-3940-3p, preventing the degradation of its target gene KLLN, which acts as a tumor-inhibiter in TNBC. Moreover, RNA pulldown, mass spectrometry, ChIP, and luciferase reporter assays confirmed that SMAD3 directly interacted with the promoter of SEAS1 and suppressed its transcription, thereby promoting TNBC progression. The clinical samples of TNBC confirmed SEAS1 was correlated inversely with lymphatic and distant metastasis. In conclusion, our findings reveal a novel pathway for TNBC progression via SMAD3/lncRNA SEAS1/miR-3940-3p/KLLN axis, and suggest that SEAS1 may serve as a potential biomarker and therapeutic target for TNBC.

The miR-4732-5p/XPR1 axis suppresses the invasion, metastasis, and epithelial-mesenchymal transition of lung adenocarcinoma via the PI3K/Akt/GSK3β/Snail pathway

The roles of microRNAs (miRNAs) in the occurrence, metastasis, and prognosis of lung adenocarcinoma (LUAD) have been drawing extensive attention from researchers. The aim of this study is to identify the effects of miR-4732-5p on the migration, invasion, and metastasis of LUAD. In this study, we found that the expression of miR-4732-5p was decreased in LUAD based on the data derived from The Cancer Genome Atlas (TCGA) database, tissues, and cell lines. LUAD patients with a low expression of miR-4732-5p exhibited a lower survival rate. Meanwhile, miR-4732-5p could directly target xenotropic and polytropic retrovirus receptor 1 (XPR1), and elevated XPR1 was observed in LUAD mRNA microarrays, Gene Expression Omnibus (GEO), and The Human Protein Atlas (HPA) database. Overexpression of miR-4732-5p significantly inhibits the migration, invasion, and metastasis of LUAD in vitro and in vivo, which can be reversed by overexpression of XPR1. We also found that the PI3K/Akt/GSK3β/Snail pathway induced by EGF induced EMT could be inhibited by miR-4732-5p overexpression and XPR1 knockdown. The migration and invasion of LUAD could be converted by cytoskeletal rearrangements, and the polymerization of EGF induced F-actin in A549 cells could be inhibited by elevated miR-4732-5p. Our results suggest that miR-4732-5p exerts anti-tumor effects on the invasion and metastasis of LUAD by regulating XPR1 in vivo and in vitro, indicating that the miR-4732-5p/XPR1 axis may be a potential target for LUAD therapeutic intervention.

Functional Screen for microRNAs Suppressing Anchorage-Independent Growth in Human Cervical Cancer Cells

The progression of anchorage-dependent epithelial cells to anchorage-independent growth represents a critical hallmark of malignant transformation. Using an in vitro model of human papillomavirus (HPV)-induced transformation, we previously showed that acquisition of anchorage-independent growth is associated with marked (epi)genetic changes, including altered expression of microRNAs. However, the laborious nature of the conventional growth method in soft agar to measure this phenotype hampers a high-throughput analysis. We developed alternative functional screening methods using 96- and 384-well ultra-low attachment plates to systematically investigate microRNAs regulating anchorage-independent growth. SiHa cervical cancer cells were transfected with a microRNA mimic library (n = 2019) and evaluated for cell viability. We identified 84 microRNAs that consistently suppressed growth in three independent experiments. Further validation in three cell lines and comparison of growth in adherent and ultra-low attachment plates yielded 40 microRNAs that specifically reduced anchorage-independent growth. In conclusion, ultra-low attachment plates are a promising alternative for soft-agar assays to study anchorage-independent growth and are suitable for high-throughput functional screening. Anchorage independence suppressing microRNAs identified through our screen were successfully validated in three cell lines. These microRNAs may provide specific biomarkers for detecting and treating HPV-induced precancerous lesions progressing to invasive cancer, the most critical stage during cervical cancer development.

Long non-coding RNA LINC00472 inhibits oral squamous cell carcinoma via miR-4311/GNG7 axis

Emerging studies indicate that long non-coding RNAs play important roles in oral squamous cell carcinoma (OSCC). However, the function of the majority of long non-coding RNAs is still unclear. Recently, LINC00472 has been reported to play crucial roles in multiple cancers. However, the role of LINC00472 in oral squamous cell carcinoma (OSCC) is still not clear. This study found that LncRNA LINC00472 was significantly down-regulated in several squamous cell carcinoma cancer tissues and OSCC cell lines. Over-expression of LINC00472 in OSCC cells inhibited OSCC progression and alleviated OSCC immune responses. Additionally, we confirmed that LINC00472 functioned as an hsa-miR-4311 sponge and regulated the expression of GNG7 (guanine nucleotide-binding protein, gamma 7). Also, we found that LINC00472 over-expression could suppress xenograft tumor growth in vivo. Our study provides evidence that LINC00472 plays an essential role in inhibiting oral squamous cell carcinoma progression and affecting immune responses by directly binding to hsa-miR-4311 to regulate the expression of GNG7 positively.

LINC00472 suppresses oral squamous cell carcinoma growth by targeting miR-455-3p/ELF3 axis

LINC00472 is reported to play a role in suppressing tumors in cancers such as lung cancer and hepatocellular carcinoma, among others. We made investigations into the effects of LINC00472 in oral squamous cell carcinoma (OSCC) progression to explore the underlying molecular mechanisms. By qRT-PCR, we assessed the LINC00472 expression in OSCC tissues and cells and performed functional analysis to investigate how LINC00472/miR-455-3p/ELF3 impacts OSCC cell proliferation, apoptosis, and cell cycle. The role that LINC00472 plays in OSCC tumor growth was examined by establishing a xenograft model. Down-regulation of LINC00472 occurred in tissues and cells of an OSCC tumor. LINC00472 overexpression caused OSCC cell proliferation to be inhibited, cell apoptosis to be promoted, and cell cycle arrest to be induced. As a competing endogenous RNA (ceRNA), LINC00472 can block miR-455-3p function and further promote ELF3 expression. The overexpression of miR-455-3p or ELF3 knockdown was shown to be capable of reversing the anti-tumor effects of LINC00472 in OSCC. In vivo experiments confirmed the tumor-suppressing role of LINC00472 in the progression of OSCC. In short, we found that the novel LINC00472 inhibits OSCC growth via the miR-455-3p/ELF3 axis. LINC00472 and its targeted miR-455-3p/ELF3 axis may represent valuable targets for treating OSCC.

Long Noncoding RNA 00472: A Novel Biomarker in Human Diseases

Long non-coding RNAs (lncRNAs) play important roles in human diseases. They control gene expression levels and influence various biological processes through multiple mechanisms. Functional abnormalities in lncRNAs are strongly associated with occurrence and development of various diseases. LINC00472, which is located on chromosome 6q13, is involved in several human diseases, particularly cancers of the breast, lung, liver, osteosarcoma, bladder, colorectal, ovarian, pancreatic and stomach. Importantly, LINC00472 can be used as a biomarker for breast cancer cell sensitivity to chemotherapeutic regimens, including doxorubicin. LINC00472 is regulated by microRNAs and several signaling pathways. However, the significance of LINC00472 in human diseases has not been clearly established. In this review, we elucidate on the significance of LINC00472 in various human diseases, indicating that LINC00472 may be a diagnostic, prognostic as well as therapeutic target for these diseases.

Crosstalk between Circulatory Microenvironment and Vascular Endothelial Cells in Acute Myocardial Infarction

Background

The reason of high mortality of acute myocardial infarction (AMI) was the lack of exploring the cellular and molecular mechanism of AMI. Therefore, we explored the crosstalk among cells, as well as its potential molecular mechanism of mediating AMI.

Methods

The gene expression profile of peripheral blood, endothelial, platelets and mononuclear cells were applied to differentially expressed genes (DEGs) analysis. ClusterProfiler and the package of gene set enrichment analysis (GSEA) were applied to explore the potential functional pathways of DEGs in 3 types of intravascular cells (endothelial, platelets and mononuclear cells) and peripheral blood. Subsequently, we extracted the surface receptors, secreted proteins and extracellular matrix from the up-regulated DEGs to explore their potential interactions mechanism of AMI by crosstalk and pivot analysis.

Findings

A total 11 common regulated DEGs (CDEGs) were identified, which might be potential biomarkers for AMI diagnosis. The abnormal pathways involved in DEGs of 3 types of intravascular cells and peripheral blood were shown, which also verified by GSEA. Afterwards, it was found that there was crosstalk in 3 types of intravascular cells and peripheral blood. Furthermore, we constructed a cell–cell interaction map among cells in AMI regulated by exosome lncRNA, which was involved in the development of AMI. Finally, we identified 8 hub genes, which might be potential biomarkers of AMI.

Interpretation

The result of this study can not only be used as a reference for subsequent experiments and further exploration, but also contribute to the development of novel cell and molecular therapies.

Urinary exosomal long noncoding RNAs serve as biomarkers for early detection of non-small cell lung cancer

Objective: Increasing the efficiency of early diagnosis using noninvasive biomarkers is crucial for enhancing the survival rate of lung cancer patients. We explore the differential expression of non-small cell lung cancer (NSCLC)-related long noncoding RNAs (lncRNAs) in urinary exosomes in NSCLC patients and normal controls to diagnose lung cancer.

Methods: A differential expression analysis between NSCLC patients and healthy controls was performed using microarrays. Gene ontology (GO) term and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were used to predict potential functions of lncRNAs in NSCLC. quantitative real-time PCR (QT-PCR) was used to verify microarray results.

Results: A total of 640 lncRNAs (70 up- and 570 down-regulated) were differentially expressed in NSCLC patients in comparison to healthy controls. Six lncRNAs were detected by QT-PCR. GO term and KEGG pathway analyses showed that differential lncRNAs were enriched in cellular component organization or biogenesis, as well as other biological processes and signaling pathways, such as the PI3K-AKT, FOXO, p53, and fatty acid biosynthesis.

Conclusions: The differential lncRNAs in urinary exosomes are potential diagnostic biomarkers of NSCLC. The lncRNAs enriched in specific pathways may be associated with tumor cell proliferation, tumor cell apoptosis, and the cell cycle involved in the pathogenesis of NSCLC.

Anticancer roles of let-7f-1-3p in non-small cell lung cancer via direct targeting of integrin β1

Lung cancer is one of the most common types of cancer, with the highest mortality rate worldwide. MicroRNAs play notable roles in the chemotherapeutic effects of anticancer drugs. The present study used reverse transcription-quantitative PCR, western blotting and cell migration and invasion assays to reveal the role of let-7f-1-3p in non-small cell lung cancer (NSCLC) and explore the effect of let-7f-1-3p on doxorubicin (DOX) treatment. It was demonstrated that the levels of let-7f-1-3p in carcinoma tissues were lower compared with those in paracarcinoma tissues. Thus, let-7f-1-3p may act as a suppressor gene. The present study also explored the role of let-7f-1-3p in A549 and NCI-H1975 cells. Results revealed that let-7f-1-3p could inhibit the viability, migration and invasion of NSCLC cells and induce their apoptosis. Integrin β1 acted as a target gene regulated by let-7f-1-3p. This suggested that let-7f-1-3p could enhance DOX-inhibited cell viability, migration and invasion in vitro. Overall, the present study demonstrated that let-7f-1-3p may act as a target for drug design and lung cancer therapy.

LINC00472 suppressed by ZEB1 regulates the miR-23a-3p/FOXO3/BID axis to inhibit the progression of pancreatic cancer

The tumour-suppressive role of LINC00472 has been extensively reported in various human cancers such as lung, colon and ovarian cancers, yet its function in pancreatic cancer remains unidentified. Here, the current research aimed to explore the role and regulatory axis mediated by LINC00472 in the progression of pancreatic cancer. RT-qPCR was adopted to determine LINC00472 expression in the harvested pancreatic cancer tissues and adjacent normal tissues. Loss-of-function and gain-of-function experiments were performed to examine the effects of LINC00472 on proliferation and apoptosis in vitro and tumorigenesis in vivo. Immunoblotting was performed to detect the expression of several proliferation and apoptosis-related proteins. Bioinformatic analysis, dual-luciferase reporter assay and RNA pull-down were conducted to profile the relationships between LINC00472 and miR-23a-3p, between miR-23a-3p and FOXO3 and between FOXO3 and BID. The LINC00472 expression was down-regulated by ZEB1 in the pancreatic cancer cells and tissues. LINC00472 could competitively bind to miR-23a-3p to enhance the expression of FOXO3, which consequently could promote the BID expression, thereby suppressing proliferation and promoting the apoptosis of pancreatic cancer cells. Meanwhile, the inhibitory role of LINC00472 in tumorigenesis was validated in vivo, and the LINC00472-mediated miR-23a-3p/FOXO3/BID axis was also demonstrated in the nude mouse tumour formation model. The study substantiated the antitumour activity of LINC00472 in pancreatic cancer and proposed a regulatory axis in which LINC00472 competitively binds to miR-23a-3p to enhance the FOXO3 expression and promote BID expression. Consequently, these findings provide theoretical basis for developing potential targets for the treatment of pancreatic cancer.

Gene expression profiling after LINC00472 overexpression in an NSCLC cell line

Lung cancer accounts for a large proportion of cancer-related deaths worldwide. Personalized therapeutic medicine based on the genetic characteristics of non-small cell lung cancer (NSCLC) is a promising field, and discovering clinically applicable biomarkers of NSCLC is required. LINC00472 is a long non-coding RNA and has been recently suggested to be a biomarker of NSCLC, but little is known of its mechanism in NSCLC. Thus, the current study was performed to document changes in gene expression after LINC00472 overexpression in NSCLC cells. As a result of cell viability and migration assay, LINC00472 downregulated cell survival, proliferation, and motility. Transcriptome sequencing analysis showed 3,782 genes expression were changed in LINC00472 overexpressing cells. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed most genes were associated with intracellular metabolism. The PPP1R12B, RGS5, RBM5, RBL2, LDLR and PTPRM genes were upregulated by LINC00472 overexpression and these genes functioned as tumor suppressors in several cancers. In contrast, SPSB1, PCNA, CD24, CDK5, CDC25A, and EIF4EBP1 were downregulated by LINC00472, and they functioned as oncogenes in various cancers. Consequently, the function of LINC00472 in tumorigenesis might be related to changes in the expressions of other oncogenes and tumor suppressors.

Comprehensive Analysis of Regulatory Network for LINC00472 in Clear Cell Renal Cell Carcinoma

Renal cell carcinoma (RCC) accounts for about 2% to 3% of adult malignancies, and clear cell renal cell carcinoma (ccRCC) is the most common and aggressive type of kidney cancer. It accounts for 75% of all kidney tumors. Although new targeted drugs continue to appear, they are still not suitable for all patients. Therefore, an in-depth study of the molecular mechanism of the development of ccRCC and exploration of new targets for the treatment of ccRCC will help to achieve precise treatment for ccRCC. With the development of molecular research, the study of long noncoding RNA (LncRNA) has given us a new understanding of tumors. Although LncRNA does not encode proteins, it directly interacts with proteins in various signaling pathways and affects cell functions. Therefore, it is of great significance to study the mechanism of LncRNA in ccRCC. The expression level of Linc00472 in ccRCC tissues is significantly lower than adjacent normal tissues, and its low expression is closely related to Furman's high grade. The low expression of Linc00472 is associated with poor prognosis in patients with ccRCC. The results of protein interaction and functional enrichment analysis indicate that genes upregulated in renal clear cell carcinoma may play a major role. Analysis of target gene prediction results showed that Linc00472 may be used as ceRNA in the miR-24-3p-HLA-DPB1 pathway, miR-24-3p-CXCL9 pathway, miR-221-3p-C3aR1-VEGFR2 pathway, miR-17-5p-HLA-DQA1/HLA-DQB1 pathway, and miR-17-5p-C3aR1/C5aR1-VEGFR2 pathway which play important functions. In addition, the regulatory relationship between miR-24-3p and TNFR2 (TNFRSF1B), CD36, and COL4A1 should also be noted. The value of Linc00472 in the diagnosis and treatment of ccRCC is worthy of further study.

Potential prognostic biomarkers related to immunity in clear cell renal cell carcinoma using bioinformatic strategy

The clear cell renal cell carcinoma (ccRCC) is the main pathological subtype of renal cell carcinoma. Immune system evasion, one hallmark of cancer, contributes to cancer cells in escaping from the attack of immune cells. In order to identify potential prognostic biomarkers in ccRCC patients and immune cells fraction, we collected and downloaded profiles from The Cancer Genome Atlas (TCGA) database and Gene Expression Omnibus (GEO) database. We obtained 2 modules significantly associated with tumor stage and immune cells; functional enrichment analysis showed that genes in the module ‘yellow’ were significantly enriched in proteins targeting to membrane and ribosome, as well as the oxidative phosphorylation pathway, while genes in the module ‘green’ mainly participate in molecular functions associated with immunity like activation of T cells. Four LncRNAs (LINC00472, AL590094.1, AL365203.3, and AC147651.3) and RPL27A and RPL22L1 in the module ‘yellow’ and two lncRNAs (LINC00426 and AC129507.2) and five protein-coding genes (CSF1, NOD2, ITGAE, CD7, and PDCD1) in the module ‘green’ represented independent prognostic values in patients with ccRCC. Expression of LINC0042, NOD2, CD7, and PDCD1 were significantly correlated with ratio of immune cells (like T cells CD8 and resting mast cells). LINC00426, with significant correlation with immune cell fraction, shows potential prognostic value in ccRCC patients. Our findings provide a strategy in exploring biomarkers with prognostic significance and significant association with the fraction of immune cells.

LINC00472 regulates vascular smooth muscle cell migration and proliferation via regulating miR-149-3p

LncRNAs are one group of gene modulators functioning via several mechanisms in pathological and physiological conditions. We noted that LINC00472 expression level is elevated in atherosclerotic coronary tissues compared with normal coronary artery samples. LINC00472 is also upregulated in vascular smooth muscle cells (VSMCs) induced by TNF-α and PDGF-BB. Ectopic expression of LINC00472 induced VSMC migration and proliferation. The predicted binding sequence between miR-149-3p and LINC00472 was analyzed by LncBase Predicted. Overexpression of miR-149-3p decreases the luciferase activity of wild-type reporter plasmid, but not the mutant one. Ectopic expression of LINC00472 suppresses the expression of miR-149-3p in VSMCs. Furthermore, we demonstrated that miR-149-3p expression is decreased in atherosclerotic coronary tissues. MiR-149-3p was downregulated in VSMCs induced by TNF-α and PDGF-BB. Overexpression of LINC00472 induces VSMC migration and proliferation via regulating miR-149-3p. These data suggested that LINC00472 acts a critical role in the migration and proliferation of VSMCs partly via modulating miR-149-3p.

Methylation-dependent MCM6 repression induced by LINC00472 inhibits triple-negative breast cancer metastasis by disturbing the MEK/ERK signaling pathway

Long noncoding RNAs (lncRNAs) have been identified to be dysregulated in multiple cancer types, which are speculated to be of vital significance in regulating several hallmarks of cancer biology. Triple-negative breast cancer (TNBC) is acknowledged as an aggressive subtype of breast cancer. In this study, we found the lncRNA LINC00472 was poorly expressed in TNBC tissues and cells. Overexpression of LINC00472 could inhibit the proliferation, invasion and migration of MDA-MB-231 cells. On the contrary, minichromosome maintenance complex component 6 (MCM6) was highly expressed in TNBC tissues and MDA-MB-231 cells due to suppressed methylation. LINC00472 induced site-specific DNA methylation and reduced the MCM6 expression by recruiting DNA methyltransferases into the MCM6 promoter. Since the restoration of MCM6 weakened the tumor-suppressive effect of LINC00472 on MDA-MB-231 cells, LINC00472 potentially acted as a tumor suppressor by inhibiting MCM6. In addition, in vivo experiments further substantiated that overexpression of LINC00472 inhibited tumor growth and metastasis to lungs by decreasing the expression of MCM6. Overall, the present study demonstrated that LINC00472-mediated epigenetic silencing of MCM6 contributes to the prevention of tumorigenesis and metastasis in TNBC, providing an exquisite therapeutic target for TNBC.

Genome-wide Identification of Differently Expressed lncRNAs, mRNAs, and circRNAs in Patients with Osteoarthritis

Background:

Osteoarthritis (OA), one of the most important causes leading to joint disability, was considered as an untreatable disease. A series of genes were reported to regulate the pathogenesis of OA, including microRNAs, Long non-coding RNAs and Circular RNA. So far, the expression profiles and functions of lncRNAs, mRNAs, and circRNAs in OA are not fully understood.

Objective:

The present study aimed to identify differentially expressed genes in OA.

Methods:

The present study conducted RNA-seq to identify differentially expressed genes in OA. Ontology (GO) analysis was used to analyze the Molecular Function and Biological Process. KEGG pathway analysis was used to perform the differentially expressed lncRNAs in biological pathways.

Results:

Hierarchical clustering revealed a total of 943 mRNAs, 518 lncRNAs, and 300 circRNAs, which were dysregulated in OA compared to normal samples. Furthermore, we constructed differentially expressed mRNAs mediated protein-protein interaction network, differentially expressed lncRNAs mediated trans-regulatory networks, and competitive endogenous RNA (ceRNA) to reveal the interaction among these genes in OA. Bioinformatics analysis revealed that these dysregulated genes were involved in regulating multiple biological processes, such as wound healing, negative regulation of ossification, sister chromatid cohesion, positive regulation of interleukin-1 alpha production, sodium ion transmembrane transport, positive regulation of cell migration, and negative regulation of inflammatory response. To the best of our knowledge, this study for the first time, revealed the expression pattern of mRNAs, lncRNAs and circRNAs in OA.

Conclusion:

This study provided novel information to validate these differentially expressed RNAs may be as possible biomarkers and targets in OA.

MicroRNA‑149‑3p inhibits cell proliferation by targeting AKT2 in oral squamous cell carcinoma

MicroRNAs (miRs) exhibit oncogenic or tumor suppressive functions that contribute to the initiation and development of various types of human cancer. miR-149-3p has been reported to serve multiple roles in the regulation of proliferation, apoptosis and metastasis. However, the effects and detailed mechanism of miR-149-3p in oral squamous cell carcinoma (OSCC) remain unclear. In the present study, miR-149-3p mimic, mimic control, miR-149-3p inhibitor and inhibitor control were transiently transfected into Cal27 and SCC-9 cells. The viability, proliferation and apoptosis of OSCC cells were determined using Cell Counting Kit-8, colony formation and Annexin V assays, respectively. The mRNA expression levels of miR-149-3p and AKT2 were determined by reverse transcription-quantitative PCR. The protein expression levels of AKT2, cleaved caspase-3 and cleaved PARP were examined by western blot analysis. The binding of miR-149-3p to the AKT2 3′-untranslated region was evaluated by a dual luciferase reporter assay. In the present study, overexpression of miR-149-3p reduced the viability and proliferation of OSCC cells. By contrast, increased cell viability and proliferation was observed in miR-149-3p-deficient OSCC cells. Dual luciferase reporter assay indicated that miR-149-3p significantly decreased the luciferase activity of the wild-type AKT2 3′-untranslated region. Moreover, overexpression of miR-149-3p downregulated the mRNA and protein expression levels of AKT2, suggesting that miR-149-3p was a negative modulator of AKT2. Restoration of AKT2 efficiently reversed the miR-149-3p-mediated reduction in the proliferative capacity of OSCC cells. In addition, miR-149-3p enhanced the sensitivity of OSCC cells to the chemotherapeutic drug 5-fluorouracil. Taken together, the current findings revealed an inhibitory effect of miR-149-3p on the proliferation of OSCC cells through the post-transcriptional suppression of AKT2, and indicated a potential chemosensitizing function of miR-149-3p for the treatment of patients with OSCC.

miR-4270 Modulates the Irradiation-Sensitivity of Nasopharyngeal Carcinoma Cells through Modulation of p53 in Vivo

The lowered sensitivity to irradiation considerably impacted on the prognosis of nasopharyngeal carcinoma treatments. This study aimed to explore the functions of miR-4270 in nasopharyngeal carcinoma. Bioinformatic analysis was performed online accessing GSE139164 dataset to screen the top 30 differential microRNAs in nasopharyngeal carcinoma patients with radio-sensitivity. Cancer cell lines, 6-10B and 5-8F, were cultured and measured for expression of miR-4270 and TP53 (the gene of the tumor suppressor protein p53) with the normal nasopharyngeal epithelial cells as a control. The miR-4270 expression was regulated in cells via the introduction of miR-4270 inhibitor or mimic in different concentrations (25, 50, 100 nmol/L). Targetscan predicted the target of miR-4270 and the bindings while luciferase was used to confirm this. CCK8 methods were used to evaluate the irradiation sensitivity of the cells after exposure to increasing X-Ray irradiation. RT-PCR detected the RNA expression and Western blot examined the protein expression of p53. Flow cytometry detected the cell apoptosis rates respectively. miR-4270 is among the top differential microRNAs between the radio-sensitive and -resistant patients. In vivo, miR-4270 expression was lower in cancer cell lines. The inhibition of miR-4270 raised the cell sensitivity to irradiation. miR-4270 negatively mediated TP53 and targeted TP53. Additionally, p53 increased cell sensitivity to irradiation and modulated by miR-4270 in nasopharyngeal carcinoma cells. In conclusion, this study first reports that miR-4270 is lower in the radio-sensitive patients and modulated the irradiation-sensitivity of nasopharyngeal carcinoma cells through modulation of p53 in vivo.

Long non-coding RNAs as potential biomarkers in the prognosis and diagnosis of lung cancer: A review and target analysis

Long non-coding RNAs (lncRNA) have been emerged as a novel class of molecular regulators in cancer. They are dysregulated in many types of cancer; however, there is not enough knowledge available on their expression and functional profiles. Lung cancer is the leading cause of the cancer deaths worldwide. Generally, lncRNAs may be associated with lung tumor pathogenesis and they may act as biomarkers for the cancer prognosis and diagnosis. Compared to other invasive prognostic and diagnostic methods, detection of lncRNAs might be a user-friendly and noninvasive method. In this review article, we selected 27 tumor-associated lncRNAs by literature reviewing to further discussing in detail for using as diagnostic and prognostic biomarkers in lung cancer. Also, in an in silico target analysis, the "Experimentally supported functional regulation" approach of the LncTarD web tool was used to identifying the target genes and regulatory mechanisms of the selected lncRNAs. The reports on diagnostic and prognostic potential of all selected lncRNAs were discussed. However, the target genes and regulatory mechanisms of the 22 lncRNAs were identified by in silico analysis and we found the pathways that are controlled by each target group of lncRNAs. They use epigenetic mechanisms, ceRNA mechanisms, protein interaction and sponge mechanism. Also, 10, 23, 5, and 28 target genes for each of these mechanisms were identified, respectively. Finally, each group of target genes controls 50, 12, 7, and 2 molecular pathways, respectively. In conclusion, LncRNAs could be used as biomarkers in lung cancer due to their roles in control of several signaling pathways related to lung tumors. Also, it seems that lncRNAs, which use epigenetic mechanisms for modulating a large number of pathways, could be considered as important subjects for lung cancer-related diagnostic and prognostic biomarkers.

Identification of nuclear export signal in KLLN suggests potential role in proteasomal degradation in cancer cells

Germline and somatic promoter hypermethylation of KLLN has been found in diverse heritable and sporadic cancers, respectively. KLLN has many identified tumor suppressor functions, and when first reported, was thought to be exclusively nuclear. Here, we report on KLLN localization in both the nucleus and cytoplasm and the identification of a putative nuclear export signal (NES) sequence. KLLN overexpression in colon and breast cancer cells showed both nuclear and cytoplasmic presence. Inhibition of the CRM1 export pathway increased nuclear sequestration of KLLN, confirming the prediction of an NES sequence. Point mutations introduced in the predicted NES sequence decreased the strength of the NES and increased the nuclear sequestration of KLLN. Contrary to expectations, the transcription regulation and cellular proliferation functions of KLLN were unaffected by increased KLLN nuclear sequestration. Instead, increased nuclear KLLN correlated with increased nuclear sequestration of TRIM25 and decreased inhibitory phosphorylation of MDM2. Computational analysis of The Cancer Genome Atlas (TCGA) dataset showed positive correlation among KLLN, TRIM25 and MDM2 expression; pathway analysis of the common genes downstream of these three genes revealed protein degradation as one of the top canonical pathways. Together, our observations suggest that CRM1 pathway-based nuclear export of KLLN may impact proteasomal degradation.

Long non-coding RNA maternally expressed gene regulates cigarette smoke extract induced lung inflammation and human bronchial epithelial apoptosis via miR-149-3p

Chronic obstructive pulmonary disease (COPD) has become a significant public health risk. Long non-coding RNAs (lncRNAs) have been identified as important factors involved in the proliferation, apoptosis and inflammatory cytokine expression of lung cells. Peripheral blood samples from 66 subjects (18 non-smokers, 24 smokers without COPD and 28 smokers with COPD) and HBE135-E6E7 cell treated with cigarette smoke extract (CSE) or not were used as the research object. The aim of the present study was to investigate the underlying mechanism of lncRNA maternally expressed gene 3 (MEG3) in COPD. Following transfection with microRNA (miR)-149-3p mimics, miR-negative control mimics, miR-149-3p inhibitor, miR-negative control inhibitor, small interfering (si)RNA targeting MEG3 (si-MEG3) and si-negative control (si-NC), levels of MEG3 and microRNA (miR)-149-3p were detected using reverse transcription-quantitative PCR, Proliferation and apoptosis were examined using the Cell Counting Kit-8 and flow cytometry assays, respectively. Enzyme-linked immunosorbent assay (ELISA) was performed to detect the expression of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). Protein levels of B-cell lymphoma-2 (Bcl-2), cleaved-caspase-3, cleaved-caspase-9, phosphorylated (p)-p65, total (t)-p65, p-lkBα and t-lkBα were measured by western blotting. Luciferase assay was conducted to examine the relationship between MEG3 and miR-149-3p. LncRNA MEG3 was highly expressed, whereas miR-149-3p expression was downregulated in smokers with COPD peripheral blood samples, compared with non-smokers and smokers without COPD samples. Compared with untreated human bronchial epithelial (HBE) cells, MEG3 expression was increased in cigarette smoke extract (CSE)-treated HBE cells. Compared with CSE-treated HBE cells transfected with si-NC, MEG3 knockdown promoted cell proliferation and inhibited apoptosis in CSE-treated HBE cells transfected with si-MEG3, and it also decreased the levels of IL-6, TNF-α, Bcl-2 and increased cleaved-caspase-3 and cleaved-caspase-9 in CSE-treated HBE cells transfected with si-MEG3. The luciferase assay demonstrated that miR-149-3p has target sites for MEG3. MEG3 was demonstrated to regulate the NF-κB signaling pathway by sponging miR-149-3p in CSE-treated HBE cells. In conclusion, these findings suggested that MEG3 promoted proliferation and inhibited apoptosis by regulating the NF-κB signal pathway via miR-149-3p in CSE-treated HBE cells. These results provide an insight for further verification and understanding of the molecular basis of COPD.

Down-regulation of long noncoding RNA LINC00472 alleviates sepsis-induced acute hepatic injury by regulating miR-373-3p/TRIM8 axis

BACKGROUND

The long noncoding RNAs (lncRNAs) have been confirmed to be involved in sepsis-induced organ injury. Here, we first investigated the functional role and the underlying mechanism of lncRNA LINC00472 in sepsis-induced acute hepatic injury (AHI).

METHODS

Human liver THLE-3 cells were treated with lipopolysaccharide (LPS) to mimic sepsis-induced AHI in vitro; intraperitoneal injection of LPS in rats were used as an in vivo model of AHI induced by sepsis. The expressions of LINC00472, miR-373-3p, and TRIM8 mRNA were detected by qRT-PCR. The effects of LINC00472 and miR-373-3p on the viability of THLE-3 cells were assessed by CCK-8 assay. Dual-luciferase reporter and RNA immunoprecipitation (RIP) assays were performed to determine the binding relationship between LINC00472 and miR-373-3p as well as between miR-373-3p and TRIM8. The expressions of apoptosis-related proteins and TRIM8 were detected by Western blot; the levels of ALT, AST, TNF-α, IL-6, and IL-10 in the serum of rats were measured using ELSA assay.

RESULTS

LINC00472 and TRIM8 were significantly upregulated in liver tissues and THLE-3 cells in sepsis-induced AHI models, while miR-373-3p was downregulated. Silencing of LINC00472 promoted cell viability and suppressed cell apoptosis in LPS-treated THLE-3 cells, whereas upregulation of LINC00472 had the opposite effect. Moreover, LINC00472 served as a sponge for miR-373-3p and negatively regulated its expression. miR-373-3p mimics could promote THLE-3 cell viability and suppress cell apoptosis. Additionally, TRIM8 was a direct target of miR-373-3p, which was downregulated in LINC00472-silenced cells and upregulated by the miR-373-3p inhibitor. Further, the co-transfection of miR-373-3p inhibitor reversed the effects of LINC00472 knockdown on cell viability and apoptosis. Downregulation of LINC00472 in rats restored the levels of ALT, AST, IL-6, IL-10, and TNF-α.

CONCLUSION

Downregulation of LINC00472 ameliorates sepsis-induced AHI by regulating the miR-373-3p/TRIM8 axis.

Identification of a prognostic LncRNA signature for ER-positive, ER-negative and triple-negative breast cancers

PURPOSE

The development of multi-gene signatures has led to improvements in identification of breast cancer patients at high risk of recurrence. The prognostic power of commercially available gene signatures is mostly restricted to estrogen receptor (ER)-positive breast cancer. On the contrary, immune-related gene signatures predict prognosis only in ER-negative breast cancer. This study aimed to develop a better prognostic signature for breast cancer.

METHODS

The expressions of long non-coding RNA (lncRNA) genes from 30 independent microarray datasets with a total of 4813 samples were analyzed. A prognostic lncRNA signature was developed based on likelihood-ratio Cox regression analysis. Survival analysis was used to compare the prognostic efficiencies of our signature and 10 previously reported prognostic gene signatures.

RESULTS

Cox regression analysis on 30 independent datasets showed that the 6-lncRNA signature identified in this study performed as well as five commercially available signatures in recurrence prediction for ER-positive breast cancer. In ER-negative breast cancer, this lncRNA signature was as prognostic as three immune-related gene signatures. Moreover, our lncRNA signature also demonstrated a good capacity to predict recurrence risk for triple-negative breast cancer. Function analysis showed that several lncRNAs in this signature were probably involved in cell proliferation and immune processes.

CONCLUSIONS

A six-LncRNA signature was identified that is prognostic for ER-positive, ER-negative, and triple-negative breast cancers and thus deserves further validation in prospective studies.

Functional Significance of Mirna-149 in Lung Cancer: Can it be Utilized as a Potential Biomarker or a Therapeutic Target?

Accumulating evidence has documented the significance of miR-149 as a promising tumor-suppressive non-coding RNA that play critical roles in regulating genes involved in cancer growth and metastasis. Notably, the ability of miR-149 to be utilized as a potential biomarker in the diagnosis/prognosis or a therapeutic target has also been explored using various cellular and preclinical models, as well as in clinical settings of lung cancer. While the applicability of miR-149 in assessing tumor progression has been suggested, its potential in predicting treatment outcomes is needed to be verified in diverse settings of lung cancer patients. The current review presents an overview of the functional significance of miR-149 with ongoing challenges in non-small cell lung cancer.

Long Non-Coding RNAs As Epigenetic Regulators in Cancer

Long noncoding RNAs (lncRNAs) constitute large portions of the mammalian transcriptome which appeared as a fundamental player, regulating various cellular mechanisms. LncRNAs do not encode proteins, have mRNA-like transcripts and frequently processed similar to the mRNAs. Many investigations have determined that lncRNAs interact with DNA, RNA molecules or proteins and play a significant regulatory function in several biological processes, such as genomic imprinting, epigenetic regulation, cell cycle regulation, apoptosis, and differentiation. LncRNAs can modulate gene expression on three levels: chromatin remodeling, transcription, and post-transcriptional processing. The majority of the identified lncRNAs seem to be transcribed by the RNA polymerase II. Recent evidence has illustrated that dysregulation of lncRNAs can lead to many human diseases, in particular, cancer. The aberrant expression of lncRNAs in malignancies contributes to the dysregulation of proliferation and differentiation process. Consequently, lncRNAs can be useful to the diagnosis, treatment, and prognosis, and have been characterized as potential cancer markers as well. In this review, we highlighted the role and molecular mechanisms of lncRNAs and their correlation with some of the cancers.

microRNA-4270-5p inhibits cancer cell proliferation and metastasis in hepatocellular carcinoma by targeting SATB2

Hepatocellular carcinoma (HCC) remains a lethal cancer type for both males and females. MicroRNAs (miRNAs) contribute to the initiation, development and metastasis of cancer. Although several miRNAs have been identified as drivers or suppressors of HCC, the molecular mechanisms of many miRNAs have not been investigated. Currently, we discovered that miR-4270-5p was a significantly downregulated miRNA in HCC. We revealed that miR-4270-5p overexpression inhibited cell proliferation and invasion of HCC cells. The data manifested that miR-4270-5p directly targeted SATB2, a key regulator of epithelial mesenchymal transition (EMT), in HCC cells and reversed the EMT process. The rescue experiments suggested that SATB2 overexpression reversed the biological function of miR-4270-5p in HCC cells. Clinical data indicated that SATB2 expression was negatively correlated with miR-4270-5p levels in HCC patients. Our findings provided potential targets for prognosis and treatment of patients with HCC.

Circular RNA hsa_circ_0014130 Inhibits Apoptosis in Non-Small Cell Lung Cancer by Sponging miR-136-5p and Upregulating BCL2

Previous studies indicated that circular RNAs (circRNA) played vital roles in the development of non-small cell lung cancer (NSCLC). Although hsa_circ_0014130 might be a potential NSCLC biomarker, its function in NSCLC remains unknown. Thus, this study aimed to investigate the role of hsa_circ_0014130 in the progression of NSCLC. The levels of hsa_circ_0014130 in NSCLC tissues and adjacent normal tissues were determined by qRT-PCR. In addition, the expressions of Bcl-2 and cleaved caspase-3 in A549 cells were detected with Western blot analysis. Meanwhile, the dual luciferase reporter system assay was used to determine the interaction of hsa_circ_0014130 and miR-136-5p or Bcl-2 and miR-136-5p in NSCLC, respectively. The level of hsa_circ_0014130 was significantly upregulated in NSCLC tissues. Downregulation of hsa_circ_0014130 markedly inhibited the proliferation and invasion of A549 cells via inducing apoptosis. In addition, downregulation of hsa_circ_0014130 inhibited the tumorigenesis of subcutaneous A549 xenograft in mice in vivo. Meanwhile, mechanistic analysis indicated that downregulation of hsa_circ_0014130 decreased the expression of miR-136-5p-targeted gene Bcl-2 via acting as a competitive "sponge" of miR-136-5p. In this study, we found that hsa_circ_0014130 was upregulated in NSCLC tissues. In addition, hsa_circ_0014130 functions as a tumor promoter in NSCLC to promote tumor growth through upregulating Bcl-2 partially via "sponging" miR-136-5p. IMPLICATIONS: In conclusion, hsa_circ_0014130 might function as a prognostic factor for patients with NSCLC and might be a therapeutic target for the treatment of NSCLC in future.

Circular RNA Expression Profiles and the Pro-tumorigenic Function of CircRNA_10156 in Hepatitis B Virus-Related Liver Cancer

Liver cancer is one of the most common malignant tumors in the world. Circular RNAs (circRNAs) perform important functions in cancer progression and are regarded as prospective biomarkers for cancer diagnosis and therapy. Here, we used the high-throughput RNA sequencing technology in conjunction with bioinformatics tools to profile circRNA expression in patients with HBV-related liver cancer. A total of 13,124 circRNAs were identified in HBV-related liver cancer, approximately 86.25% of which were sense-overlapping circRNAs. Moreover, 2,996 circRNAs exhibited different expression patterns between liver cancer tissues and matched pericancerous tissues. Function annotation indicated that these aberrantly expressed circRNAs were primarily engaged in cellular processes and cancer-associated pathways. Notably, the circRNA-miRNA interaction networks showed that 6,020 circRNAs were predicted to target 1,654 miRNAs. Quantitative RT-PCR (qRT-PCR) assay indicated that ten randomly selected circRNAs displayed consistent expression patterns with the sequencing results. We further predicted that circRNA_10156 might work as a molecular sponge of miR-149-3p, which served an important function in tumor development. Consequently, our results demonstrated that depletion of circRNA_10156 upregulated miR-149-3p, reduced Akt1 expression, and suppressed liver cancer cell proliferation. The present study will facilitate the elucidation of biological functions of circRNAs in the progression of HBV-related liver cancer providing prospective biomarkers and therapeutic targets for this disease. Our findings also reveal that circRNA_10156 might represent a promising therapeutic target for liver cancer management.