LINC00667 promotes Wilms' tumor metastasis and stemness by sponging miR-200b/c/429 family to regulate IKK-β

LINC00667: A Novel Vital Oncogenic LincRNA

Long intergenic noncoding RNAs (lincRNAs) have a variety of properties that differ from those of messenger RNAs (mRNAs) encoding proteins. Long intergenic nonprotein coding RNA 667 (LINC00667) is a non-coding transcript located on chromosome 18p11.31. Recently, many studies have found that LINC00667 can enhance the progression of various cancers and play a key part in a lot of diseases, such as tumorigenesis. Therefore, LINC00667 can be recognized as a potential biomarker and therapeutic target. So, we reviewed the biological functions, relevant mechanisms, as well as clinical significance of LINC00667 in several human cancers in detail.

LncRNA LINC01339 Hinders the Development of Wilms' Tumor via MiR-135b-3p/ADH1C Axis

Wilms' tumor is a malignant renal cancer that arises within the pediatric urinary system. This study intended to investigate how a novel long non-coding RNA LINC01339 functions in the pathogenesis of Wilms' tumor. An elevated miR-135b-3p expression as well as reduced levels of LINC01339 and ADH1C were observed in Wilms' tumor. LINC01339 mediated ADH1C expression by directly binding to miR-135b-3p. The enforced LINC01339 or ADH1C markedly hindered cell growth and migration in Wilms' tumor. The LINC01339 overexpression also repressed the growth of Wilms' tumors in vivo, whereas miR-135b-3p overexpression exerted the opposite effects on Wilms' tumor cells in vitro. Additionally, upregulating miR-135b-3p reversed LINC01339's effects on the cellular processes of Wilms' tumor cells, whereas ADH1C overexpression offset the cancer-promoting influence of miR-135b-3p upregulation on Wilms' tumor progression. Therefore, LINC01339 prevents Wilms' tumor progression by modulating the miR-135b-3p/ADH1C axis. Our findings substantiate that the LINC01339/miR-135 b-3p/ADH1C regulatory axis has potential to be a target for the treatment of Wilms' tumor.

LncRNA LINC00667 gets involved in clear cell renal cell carcinoma development and chemoresistance by regulating the miR-143-3p/ZEB1 axis

BACKGROUND

Clear cell renal cell carcinoma (ccRCC) is identified as a malignant tumor in the urinary tract. The research was an attempt to probe the biological function and molecular mechanism of lncRNA LINC00667 in ccRCC development.

METHODS

qRT-PCR monitored LINC00667, miR-143-3p, and ZEB1 levels. The models of LINC00667, miR-143-3p, and ZEB1 overexpression or knockdown were constructed in ccRCC cells. Cell proliferation, apoptosis, migration, and invasion of the cells were detected. The levels of apoptosis-associated proteins and epithelial-mesenchymal transition (EMT)-related proteins, and ZEB1 were detected by WB. Dual-luciferase reporter assay and RNA pull-down assay identified the binding association between LINC00667 and miR-143-3p, miR-143-3p and ZEB1. Moreover, a xenograft tumor model in nude mice was used for evaluating tumor growth in vivo.

RESULTS

LINC00667 and ZEB1 displayed high expression in ccRCC tissues and cells. miR-143-3p was lowly expressed in ccRCC tissues and cells. LINC00667 targeted and repressed miR-143-3p, which inhibited ZEB1 expression in a targeted manner. Overexpression of LINC00667 facilitated ccRCC cell proliferation, migration, invasion and EMT and retarded apoptosis, whereas LINC00667 knockdown or miR-143-3p overexpression exerted reverse effects. The rescue experiments indicated that overexpressing miR-143-3p dampened LINC00667-mediated oncogenic effects. Overexpressing ZEB1 diminished miR-143-3p-mediated tumor-suppressive effects. In-vivo experiments displayed that overexpression of LINC00667 contributed to the tumor growth of ccRCC cells, in contrast to miR-143-3p overexpression, which restrained the tumor growth.

CONCLUSIONS

LINC00667 is up-regulated in ccRCC and enhances the ZEB1 expression by targeting miR-143-3p, which in turn accelerates ccRCC progression and induces chemoresistance.

Roles of lncRNAs in childhood cancer: Current landscape and future perspectives

According to World Health Organization (WHO), cancer is the leading cause of death for children and adolescents. Leukemias, brain cancers, lymphomas and solid tumors, such as neuroblastoma, ostesarcoma and Wilms tumors are the most common types of childhood cancers. Approximately 400,000 children and adolescents between the ages of 0 and 19 are diagnosed with cancer each year worldwide. The cancer incidence rates have been rising for the past few decades. Generally, the prognosis of childhood cancers is favorable, but the survival rate for many unresectable or recurring cancers is substantially worse. Although random genetic mutations, persistent infections, and environmental factors may serve as contributing factors for many pediatric malignancies, the underlying mechanisms are yet unknown. Long non-coding RNAs (lncRNAs) are a group of transcripts with longer than 200 nucleotides that lack the coding capacity. However, increasing evidence indicates that lncRNAs play vital regulatory roles in cancer initiation and development in both adults and children. In particular, many lncRNAs are stable in cancer patients' body fluids such as blood and urine, suggesting that they could be used as novel biomarkers. In support of this notion, lncRNAs have been identified in liquid biopsy samples from pediatric cancer patients. In this review, we look at the regulatory functions and underlying processes of lncRNAs in the initiation and progression of children cancer and discuss the potential of lncRNAs as biomarkers for early detection. We hope that this article will help researchers explore lncRNA functions and clinical applications in pediatric cancers.

The role of miR-200 family in the regulation of hallmarks of cancer

MiRNAs are short non-coding RNAs that regulate gene expression post-transcriptionally contributing to the development of different diseases including cancer. The miR-200 family consists of five members, miR-200a, miR-200b, miR-200c, miR-141, and miR-429. Their expression is dysregulated in cancer tissue and their level is altered in the body fluids of cancer patients. Moreover, the levels of miR-200 family members correlate with clinical parameters such as cancer patients' survival which makes them potentially useful as diagnostic and prognostic biomarkers. MiRNAs can act as either oncomiRs or tumor suppressor miRNAs depending on the target genes and their role in the regulation of key oncogenic signaling pathways. In most types of cancer, the miR-200 family acts as tumor suppressor miRNA and regulates all features of cancer. In this review, we summarized the expression pattern of the miR-200 family in different types of cancer and their potential utility as biomarkers. Moreover, we comprehensively described the role of miR-200 family members in the regulation of all hallmarks of cancer proposed by Hanahan and Weinberg with the focus on the epithelial-mesenchymal transition, invasiveness, and metastasis of tumor cells.

LncRNA OSTM1-AS1 acts as an oncogenic factor in Wilms' tumor by regulating the miR-514a-3p/MELK axis

Wilms' tumor (WT) is the most typical basic renal tumor in children and is associated with a high recurrence rate and improper diagnosis. Long noncoding RNAs (lncRNAs) play important roles in WT development. However, the impact of the OSTM1 antisense RNA 1 (OSTM1-AS1) lncRNA on WT remains largely unexplored. Differential expression of OSTM1-AS1, miR-514a-3p and maternal embryonic leucine zipper kinase (MELK) in mice with WT cells was assessed via quantitative reverse transcription-PCR and western blotting. Changes in the proliferation, migration and apoptosis of WT cells after OSTM1-AS1, miR-514a-3p or MELK knockdown were assessed using the cell counting kit-8, Transwell and caspase-3 activity assays, respectively. Additionally, the tumorigenicity of WT cells after OSTM1-AS1 knockdown in vivo was analyzed using a xenograft tumor assay. The association among OSTM1-AS1, MELK and miR-514a-3p was confirmed using the RNA binding protein immunoprecipitation and luciferase reporter assays. OSTM1-AS1 and MELK were upregulated in WT cells, whereas miR-514a-3p was downregulated. OSTM1-AS1 was mostly observed in the cytoplasm, and its knockout suppressed WT cell migration and proliferation in vitro , triggered apoptosis and attenuated tumor development in vivo . MiR-514a-3p was sponged by OSTM1-AS1, and miR-514a-3p interference counteracted the tumoricidal effect of OSTM1-AS1 knockdown. MiR-514a-3p reduced WT progression by downregulating the expression of MELK, which is the target gene of miR-514a-3p. lncRNA OSTM1-AS1 acts as an oncogenic factor in WT by releasing MELK through sponging miR-514a-3p and could be a useful target for WT diagnosis and therapy.

LINC00667 Promotes Progression of Esophageal Cancer Cells by Regulating miR-200b-3p/SLC2A3 Axis

BACKGROUND

Recently, more and more evidence indicated that the long non-coding RNA was strictly related to the occurrence and progression of human cancers, including esophageal cancer (EC). We observed that LINC00667 was increased in EC, but the function of LINC00667 was unclear. Therefore, the function and potential molecular mechanism of LINC00667 in the progression of EC need to be further studied.

METHODS

Quantitative real-time PCR was used to investigate the levels of LINC00667, miR-200b-3p, and SLC2A3. The levels of protein involved in cell cycle, cell apoptosis, epithelial-mesenchymal transition, as well as SLC2A3 were quantitatived by western blot. The role of LINC00667 in the proliferative, migratory and invasive capabilities of EC cells were measured by cell counting kit-8 assay, EdU assay, flow cytometry assay, wound healing assay and transwell assay, respectively. Interaction between LINC00667 and miR-200b-3p or miR-200b-3p and SLC2A3 were confirmed using a luciferase reporter assay.

RESULTS

In this work, we found that LINC00667 expression was up-regulated in EC cell lines, and LINC00667 knockdown inhibited cell proliferation, migration, and invasion in EC cells. In addition, it showed that LINC00667 functioned as competitive endogenous RNA for miR-200b-3p by the DIANA-LncBase database. Moreover, we used targetscan online software to predict SLC2A3 as a target gene of miR-200b-3p. Subsequently, rescue experiments confirmed that knocking out SLC2A3 could reverse the inhibitory effect of miR-200b-3p on EC cells transfected with sh-LINC00667.

CONCLUSION

Herein, we revealed the novel mechanism of LINC00667 on regulating metastasis-related gene by sponge regulatory axis during EC metastasis. Our results demonstrated that LINC00667 plays a critical role in metastatic EC by mediating sponge regulatory axis miR-200b-3p/SLC2A3. To explore function of LINC00667/miR-200b-3p/SLC2A3 axis may provide an informative biomarker of malignancy and a highly selective anti-EC therapeutic target.

N6-methyladenine- induced LINC00667 promoted breast cancer progression through m6A/KIAA1429 positive feedback loop

Increasing evidence supports that N⁶-methyladenine (m⁶A) and long noncoding RNAs (lncRNAs) both act as master regulators involved in breast cancer (BC) tumorigenesis at epigenetic modification level. Here, our research tries to unveil the interaction of m⁶A and lncRNAs on BC progression and explore the underlying regulatory mechanism. In the current study, we found that LINC00667 was m⁶A-modified lncRNA, which was up-regulated upon the overexpression of KIAA1429. The high expression of LINC00667 was correlated with the prognosis of BC patients. Bio-functional assays indicated that LINC00667 promoted the proliferation and migration of BC cells. Mechanistic assays illustrated that KIAA1429 targeted the m⁶A modification site of LINC00667 and enhanced its mRNA stability. Moreover, LINC00667 positively regulated the KIAA1429 via sponging miR-556-5p, forming a KIAA1429/m⁶A/LINC00667/miR-556-5p feedback loop. Collectively, the central findings of our study suggest that KIAA1429-induced LINC00667 exerted its functions as an oncogene in BC progression through m⁶A-dependent feedback loop.

Metastatic EMT Phenotype Is Governed by MicroRNA-200-Mediated Competing Endogenous RNA Networks

Epithelial–mesenchymal transition (EMT) is a fundamental physiologically relevant process that occurs during morphogenesis and organ development. In a pathological setting, the transition from epithelial toward mesenchymal cell phenotype is hijacked by cancer cells, allowing uncontrolled metastatic dissemination. The competing endogenous RNA (ceRNA) hypothesis proposes a competitive environment resembling a large-scale regulatory network of gene expression circuits where alterations in the expression of both protein-coding and non-coding genes can make relevant contributions to EMT progression in cancer. The complex regulatory diversity is exerted through an array of diverse epigenetic factors, reaching beyond the transcriptional control that was previously thought to single-handedly govern metastatic dissemination. The present review aims to unravel the competitive relationships between naturally occurring ceRNA transcripts for the shared pool of the miRNA-200 family, which play a pivotal role in EMT related to cancer dissemination. Upon acquiring more knowledge and clinical evidence on non-genetic factors affecting neoplasia, modulation of the expression levels of diverse ceRNAs may allow for the development of novel prognostic/diagnostic markers and reveal potential targets for the disruption of cancer-related EMT.

LncRNA LINC00667 aggravates the progression of hepatocellular carcinoma by regulating androgen receptor expression as a miRNA-130a-3p sponge

Emerging studies have found long noncoding RNAs, widely expressed in eukaryotes, crucial regulators in the progression of human cancers, including hepatocellular carcinoma (HCC). Although the long intergenic noncoding RNA 667 (LINC00667) can promote the progression of a variety of cancer types, the expression pattern, the role in cancer progression, and the molecular mechanism involved in HCC remain unclear. This study aims to investigate the function and mechanism of LINC00667 in HCC progression. The effects of LINC00667 silencing in cell proliferation, cell migration, and cell invasion, and androgen receptor (AR) expression were determined with loss-of-function phenotypic analysis in Huh-7 and HCCLM3 cells, and subsequently testified in vivo in tumor growth. We found that the expression of LINC00667 was upregulated in HCC tissues and cell lines. Upregulation of LINC00667 was significantly associated with the unfavorable prognosis of HCC in our study patients. On the other hand, low expression of LINC00667 significantly inhibited the cell proliferation, cell migration and cell invasion of HCC in vitro and tumor growth in vivo. This inhibitory effect could be counteracted by miR-130a-3p inhibitor. LINC00667 reduced the inhibition of AR expression by miR-130a-3p, which correlated with the progression of HCC. Our finding suggests LINC00667 is a molecular sponge in the miR-130s-3p/AR signal pathway in the progression of HCC, in which it relieves the repressive function of miR-130a-3p on the AR expression. This indicates LINC00667 functions as a tumor promotor in promoting HCC progression through targeting miR-130a-3p/AR axis, making a novel biomarker and potential therapeutic target for HCC.

Prognostic Signature of Immune Genes and Immune-Related LncRNAs in Neuroblastoma: A Study Based on GEO and TARGET Datasets

Background

The prognostic value of immune-related genes and lncRNAs in neuroblastoma has not been elucidated, especially in subgroups with different outcomes. This study aimed to explore immune-related prognostic signatures.

Materials and Methods

Immune-related prognostic genes and lncRNAs were identified by univariate Cox regression analysis in the training set. The top 20 C-index genes and 17 immune-related lncRNAs were included in prognostic model construction, and random forest and the Least Absolute Shrinkage and Selection Operator (LASSO) regression algorithms were employed to select features. The risk score model was constructed and assessed using the Kaplan-Meier plot and the receiver operating characteristic curve. Functional enrichment analysis of the immune-related lncRNAs was conducted using the STRING database.

Results

In GSE49710, five immune genes (CDK4, PIK3R1, THRA, MAP2K2, and ULBP2) were included in the risk score five genes (RS5_G) signature, and eleven immune-related lncRNAs (LINC00260, FAM13A1OS, AGPAT4-IT1, DUBR, MIAT, TSC22D1-AS1, DANCR, MIR137HG, ERC2-IT1, LINC01184, LINC00667) were brought into risk score LncRNAs (RS_Lnc) signature. Patients were divided into high/low-risk score groups by the median. Overall survival and event/progression-free survival time were shortened in patients with high scores, both in training and validation cohorts. The same results were found in subgroups. In grouping ability assessment, the area under the curves (AUCs) in distinguishing different groups ranged from 0.737 to 0.94, better in discriminating MYCN status and high risk in training cohort (higher than 0.9). Multivariate Cox analysis demonstrated that RS5_G and RS_Lnc were the independent risk factors for overall and event/progression-free survival (all p-values <0.001). Correlation analysis showed that RS5_G and RS_Lnc were negatively associated with aDC, CD8+ T cells, but positively correlated with Th2 cells. Functional enrichment analyzes demonstrated that immune-related lncRNAs are mainly enriched in cancer-related pathways and immune-related pathways.

Conclusion

We identified the immune-related prognostic signature RS5_G and RS_Lnc. The predicting and grouping ability is close to being even better than those reported in other studies, especially in subgroups. This study provided prognostic signatures that may help clinicians to choose optimal treatment strategies and showed a new insight for NB treatment. These results need further biological experiments and clinical validation.

MiR-200a with CDC7 as a direct target declines cell viability and promotes cell apoptosis in Wilm's tumor via Wnt/β-catenin signaling pathway

MiR-200a acts as a key role in tumor malignant progression. This work purposed to assess the function of miR-200a in Wilm's tumor. Based on bioinformatics analysis, the expression, prognostic value and related pathways of miR-200a and CDC7 (a potential downstream molecule of miR-200a) in Wilm's tumor were analyzed. qRT-PCR was conducted to confirm the miR-200a level in Wilm's tumor cells. The luciferase reporter assay was carried out to verify the binding of miR-200a to 3'-UTR of CDC7. Then, the impacts of miR-200a and CDC7 on cell viability and apoptosis were measured using CCK-8 and flow cytometry assays. Also, western blot was applied to measure the expression of CDC7 as well as Wnt/β-catenin signaling pathway-related proteins and apoptosis proteins. Herein, we revealed that miR-200a was lowly expressed in Wilm's tumor tissues and cells and the low miR-200a expression is closely bound up with death and poor outcomes. Moreover, miR-200a directly targeted and inhibited CDC7 in Wilm's tumor cells. Biological function experiments illustrated that overexpression of miR-200a reduced the viability and elevated the apoptosis of Wilm's tumor cells, while overexpression of CDC7 reversed the inhibitory impact of miR-200a on cell viability and the promoting impact of miR-200a on cell apoptosis. Besides, we revealed that miR-200a/CDC7 axis can decrease the expression of β-Catenin, Cyclin D1 and C-Myc as well as the phosphorylation of GSK-3β, thus inhibiting the Wnt/β-catenin signaling pathway. Furthermore, blocking the Wnt/β-catenin signaling pathway caused an increase on cell apoptosis, while overexpression of CDC7 can reverse these impacts. Collectively, miR-200a/CDC7 axis involved in regulating the malignant phenotype of Wilm's tumor through Wnt/β-catenin signaling pathway, which provides a theoretical basis for targeted molecular therapy of Wilm's tumor.

Yin Yang 1-induced LINC00667 up-regulates pyruvate dehydrogenase kinase 1 to promote proliferation, migration and invasion of cholangiocarcinoma cells by sponging miR-200c-3p

Cholangiocarcinoma (CCA) is one of the most aggressive and lethal malignancies. Long noncoding RNAs (lncRNAs) are being found to play crucial roles in CCA progression. This work aims to investigate the roles of long intergenic non-protein coding RNA 667 (LINC00667) in progression of CCA. RT-qPCR and western blot were applied to detect gene expression. Clinical correlation and survival were analyzed by statistical methods. Overexpression and RNA interference approaches were used to investigate the effects of LINC00667 on CCA cells. Tumor xenograft assay was performed to detect the function of LINC00667 in vivo. Transcriptional regulation and competing endogenous RNA (ceRNA) mechanism were predicted via bioinformatics analysis. ChIP, luciferase reporter, and Ago2 RIP assays further confirmed the predicted results. Our data indicated that LINC00667 was highly expressed in CCA tissues and cells, and transcription factor Yin Yang 1 (YY1) induced LINC00667 expression in CCA cells. Up-regulated LINC00667 was significantly associated with lymph node metastasis, advanced TNM stage, and poor prognosis. Knockdown of LINC00667 suppressed the proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) of CCA cells, while overexpression of LINC00667 acquired opposite effects. Moreover, knockdown of LINC00667 inhibited tumor growth in vivo. In addition, LINC00667 was demonstrated to function as a ceRNA for miR-200c-3p, and then LINC00667 up-regulated pyruvate dehydrogenase kinase 1 (PDK1) to promote CCA development by inhibiting miR-200c-3p. These findings identified a pivotal role of LINC00667 in tumorigenesis and development of CCA. Targeting the YY1/LINC00667/miR-200c-3p/PDK1 axis may provide a new therapeutic strategy for CCA treatment.

Nobiletin in Cancer Therapy: How This Plant Derived-Natural Compound Targets Various Oncogene and Onco-Suppressor Pathways

Cancer therapy is a growing field, and annually, a high number of research is performed to develop novel antitumor drugs. Attempts to find new antitumor drugs continue, since cancer cells are able to acquire resistance to conventional drugs. Natural chemicals can be considered as promising candidates in the field of cancer therapy due to their multiple-targeting capability. The nobiletin (NOB) is a ubiquitous flavone isolated from Citrus fruits. The NOB has a variety of pharmacological activities, such as antidiabetes, antioxidant, anti-inflammatory, hepatoprotective, and neuroprotective. Among them, the antitumor activity of NOB has been under attention over recent years. In this review, we comprehensively describe the efficacy of NOB in cancer therapy. NOB induces apoptosis and cell cycle arrest in cancer cells. It can suppress migration and invasion of cancer cells via the inhibition of epithelial-to-mesenchymal transition (EMT) and EMT-related factors such as TGF-β, ZEB, Slug, and Snail. Besides, NOB inhibits oncogene factors such as STAT3, NF-κB, Akt, PI3K, Wnt, and so on. Noteworthy, onco-suppressor factors such as microRNA-7 and -200b undergo upregulation by NOB in cancer therapy. These onco-suppressor and oncogene pathways and mechanisms are discussed in this review.