miR-516b functions as a tumor suppressor by directly modulating CCNG1 expression in esophageal squamous cell carcinoma

MicroRNAs as the critical regulators of epithelial mesenchymal transition in pancreatic tumor cells

Pancreatic cancer (PC), as one of the main endocrine and digestive systems malignancies has the highest cancer related mortality in the world. Lack of the evident clinical symptoms and appropriate diagnostic markers in the early stages of tumor progression are the main reasons of the high mortality rate among PC patients. Therefore, it is necessary to investigate the molecular pathways involved in the PC progression, in order to introduce novel early diagnostic methods. Epithelial mesenchymal transition (EMT) is a critical cellular process associated with pancreatic tumor cells invasion and distant metastasis. MicroRNAs (miRNAs) are also important regulators of EMT process. In the present review, we discussed the role of miRNAs in regulation of EMT process during PC progression. It has been reported that the miRNAs mainly regulate the EMT process in pancreatic tumor cells through the regulation of EMT-specific transcription factors and several signaling pathways such as WNT, NOTCH, TGF-β, JAK/STAT, and PI3K/AKT. Considering the high stability of miRNAs in body fluids and their role in regulation of EMT process, they can be introduced as the non-invasive diagnostic markers in the early stages of malignant pancreatic tumors. This review paves the way to introduce a non-invasive EMT based panel marker for the early tumor detection among PC patients.

MicroRNAs: A novel signature in the metastasis of esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is a malignant epithelial tumor, characterized by squamous cell differentiation, it is the sixth leading cause of cancer-related deaths globally. The increased mortality rate of ESCC patients is predominantly due to the advanced stage of the disease when discovered, coupled with higher risk of metastasis, which is an exceedingly malignant characteristic of cancer, frequently leading to a high mortality rate. Unfortunately, there is currently no specific and effective marker to predict and treat metastasis in ESCC. MicroRNAs (miRNAs) are a class of small non-coding RNA molecules, approximately 22 nucleotides in length. miRNAs are vital in modulating gene expression and serve pivotal regulatory roles in the occurrence, progression, and prognosis of cancer. Here, we have examined the literature to highlight the intimate correlations between miRNAs and ESCC metastasis, and show that ESCC metastasis is predominantly regulated or regulated by genetic and epigenetic factors. This review proposes a potential role for miRNAs as diagnostic and therapeutic biomarkers for metastasis in ESCC metastasis, with the ultimate aim of reducing the mortality rate among patients with ESCC.

A novel link between circPDE3B and ferroptosis in esophageal squamous cell carcinoma progression

AIM

To unravel whether ferroptosis involves with the actions by circPDE3B-mediated facilitation of esophageal squamous cell carcinoma (ESCC) progression.

METHODS

Human ESCC tissues and cell lines were prepared for the evaluation of ferroptosis. Cellular iron, ROS, GSH, and MDA levels were measured to assess ferroptosis. Flow cytometry was employed to analyze apoptosis and cell cycle. Subcellular fractionation and fluorescence in situ hybridization (FISH) were conducted to validate the localization of circPDE3B. RNA pull-down, RNA immunoprecipitation (RIP), and luciferase assay were subjected to identify the molecular mechanisms. Nude mouse xenograft model was carried out to evaluate the function of circPDE3B/SLC7A11/CBS in vivo.

RESULTS

Increased circPDE3B in human ESCC specimens was positively correlated with ferroptosis-related molecules, SLC7A11 and CBS. Functionally, circPDE3B knockdown triggered ferroptosis, apoptosis, and cell cycle arrest in ESCC cells. Whereas, these effects were obviously blocked by miR-516b-5p inhibitor. Mechanistically, not only circPDE3B sponged miR-516b-5p to upregulate CBS, but also directly bound with HNRNPK to stabilize SLC7A11. In mice, depletion of circPDE3B restrained ESCC growth, while this was abolished by overexpression of CBS or SLC7A11.

CONCLUSION

In summary, circPDE3B promotes ESCC progression by suppressing ferroptosis through recruiting HNRNPK/SLC7A11 and miR-516b-5p/CBS axes.

Investigating the regulatory role of miRNAs as silent conductors in the management of pathogenesis and therapeutic resistance of pancreatic cancer

Pancreatic cancer (PC) has the greatest mortality rate of all the main malignancies. Its advanced stage and poor prognosis place it at the bottom of all cancer sites. Hence, emerging biomarkers can enable precision medicine where PC therapy is tailored to each patient. This highlights the need for new, highly sensitive and specific biomarkers for early PC diagnosis. Prognostic indicators are also required to stratify PC patients. To avoid ineffective treatment, adverse events, and expenses, biomarkers are also required for patient monitoring and identifying responders to treatment. There is substantial evidence that microRNAs (miRs, miRNAs) play a critical role in regulating mRNA and, as a consequence, protein expression in normal and malignant tissues. Deregulated miRNA profiling in PC can help with diagnosis, treatment planning, and prognosis. Furthermore, knowledge of the primary effector genes and downstream pathways in PC can help pinpoint potential miRNAs for use in treatment. Different miRNA expression profiles may serve as diagnostic, prognostic markers, and therapeutic targets across the spectrum of malignant pancreatic illness. Dysregulation of miRNAs has been linked to the malignant pathophysiology of PC through affecting many cellular functions such as increasing invasive and proliferative prospect, supporting angiogenesis, cell cycle aberrance, apoptosis elusion, metastasis promotion, and low sensitivity to particular treatments. Accordingly, in the current review, we summarize the recent advances in the roles of oncogenic and tumor suppressor (TS) miRNAs in PC and discuss their potential as worthy diagnostic and prognostic biomarkers for PC, as well as their significance in PC pathogenesis and anticancer drug resistance.

Combined inhibition of histone deacetylase and cytidine deaminase improves epigenetic potency of decitabine in colorectal adenocarcinomas

BACKGROUND

Targeting the epigenome of cancerous diseases represents an innovative approach, and the DNA methylation inhibitor decitabine is recommended for the treatment of hematological malignancies. Although epigenetic alterations are also common to solid tumors, the therapeutic efficacy of decitabine in colorectal adenocarcinomas (COAD) is unfavorable. Current research focuses on an identification of combination therapies either with chemotherapeutics or checkpoint inhibitors in modulating the tumor microenvironment. Here we report a series of molecular investigations to evaluate potency of decitabine, the histone deacetylase inhibitor PBA and the cytidine deaminase (CDA) inhibitor tetrahydrouridine (THU) in patient derived functional and p53 null colon cancer cell lines (CCCL). We focused on the inhibition of cell proliferation, the recovery of tumor suppressors and programmed cell death, and established clinical relevance by evaluating drug responsive genes among 270 COAD patients. Furthermore, we evaluated treatment responses based on CpG island density.

RESULTS

Decitabine caused marked repression of the DNMT1 protein. Conversely, PBA treatment of CCCL recovered acetylation of histone 3 lysine residues, and this enabled an open chromatin state. Unlike single decitabine treatment, the combined decitabine/PBA treatment caused > 95% inhibition of cell proliferation, prevented cell cycle progression especially in the S and G2-phase and induced programmed cell death. Decitabine and PBA differed in their ability to facilitate re-expression of genes localized on different chromosomes, and the combined decitabine/PBA treatment was most effective in the re-expression of 40 tumor suppressors and 13 genes typically silenced in cancer-associated genomic regions of COAD patients. Furthermore, this treatment repressed expression of 11 survival (anti-apoptotic) genes and augmented expression of X-chromosome inactivated genes, especially the lncRNA Xist to facilitate p53-mediated apoptosis. Pharmacological inhibition of CDA by THU or its gene knockdown prevented decitabine inactivation. Strikingly, PBA treatment recovered the expression of the decitabine drug-uptake transporter SLC15A1, thus enabling high tumor drug-loads. Finally, for 26 drug responsive genes we demonstrated improved survival in COAD patients.

CONCLUSION

The combined decitabine/PBA/THU drug treatment improved drug potency considerably, and given their existing regulatory approval, our findings merit prospective clinical trials for the triple combination in COAD patients.

Circular RNAs: pivotal role in the leukemogenesis and novel indicators for the diagnosis and prognosis of acute myeloid leukemia

Acute myeloid leukemia (AML) is an aggressive hematological malignancy and affected patients have poor overall survival (OS) rates. Circular RNAs (circRNAs) are a novel class of non-coding RNAs (ncRNAs) with a unique loop structure. In recent years, with the development of high-throughput RNA sequencing, many circRNAs have been identified exhibiting either up-regulation or down-regulation in AML patients compared with healthy controls. Recent studies have reported that circRNAs regulate leukemia cell proliferation, stemness, and apoptosis, both positively and negatively. Additionally, circRNAs could be promising biomarkers and therapeutic targets in AML. In this study, we present a comprehensive review of the regulatory roles and potentials of a number of dysregulated circRNAs in AML.

The hsa-miR-516a-5p and hsa-miR-516b-5p microRNAs reduce the migration and invasion on T98G glioblastoma cell line

microRNAs (miRNAs) are involved in numerous functions and processes in the brain and other organs through the regulation of gene and protein expression. miRNA dysregulation is associated with the development of several diseases, including the brain and Central Nervous System cancer (CNS). The hsa-miR-516a-5p and hsa-miR-516b-5p are involved in proliferation, migration, and invasion in different tumor models, but their antitumor effect has not been evaluated in cancer of CNS. Therefore, we aimed to assess the effect of the miRNAs hsa-miR-516a-5p and miRNA hsa-miR-516b-5p on the Glioblastoma cell line (T98G). We used synthetic miRNA mimics to induce the overexpression of both miRNAs in the cell line, which was corroborated by RT-qPCR. Next, we evaluated the effect on proliferation, migration, and invasion using the CyQuant direct kit, ThinCert ™ inserts and invasion BioCoat ™ Matrigel® Invasion Chambers. We found upregulation of these miRNAs induced significant changes on the migration and invasion processes of T98G cells, but not affected the proliferation rate. These results suggest that both microRNAs could be playing an important role in the control of tumor progression towards metastasis. The bioinformatics analysis showed that target genes for these miRNAs are involved in different biological processes such as in cell adhesion molecule binding and cell junction disassembly, which are important for cancer progression. Further studies and experimental validation are needed to identify the genes regulated by microRNAs.

Lidocaine represses the malignant behavior of lung carcinoma cells via the circ_PDZD8/miR-516b-5p/GOLT1A axis

Lung carcinoma is the most prevalent malignancy in adults. Lidocaine (Lido) has been confirmed to exert an anti-tumor role in many human cancers. However, the role and underlying mechanism of Lido in lung carcinoma remain poorly understood. Cell proliferation ability, migration, invasion, and apoptosis were measured by Colony formation, 5-ethynyl-2'-deoxyuridine (EdU), Cell Counting Kit-8 (CCK-8), transwell, and flow cytometry assays. Circ_PDZD8, microRNA-516b-5p (miR-516b-5p), and Golgi transport 1A (GOLT1A) levels were detected by real-time quantitative polymerase chain reaction (RT-qPCR). Protein levels of proliferating cell nuclear antigen (PCNA) and GOLT1A were examined by western blot assay. The binding relationship between miR-516b-5p and circ_PDZD8 or GOLT1A was predicted by circular RNA Interactome or Starbase 3.0 and then verified by a dual-luciferase reporter assay. The biological roles of circ_PDZD8 and Lido on lung carcinoma cell growth were examined by the xenograft tumor model in vivo. Lido suppressed proliferation, migration, invasion, and induced apoptosis in lung carcinoma cells. Circ_PDZD8 and GOLT1A were increased, miR-516b-5p was decreased in lung carcinoma tissues and cell lines. Their expression presented the opposite trend in Lido-triggered lung carcinoma cells. Circ_PDZD8 might overturn the repression of Lido on cell growth ability and metastasis in this tumor. Mechanically, circ_PDZD8 might regulate GOLT1A expression by sponging miR-516b-5p. Circ_PDZD8 weakened the anti-lung carcinoma effect of Lido in vivo. Circ_PDZD8 might mitigate the inhibitory effect of Lido on tumor cell malignancy by modulating the miR-516b-5p/GOLT1A axis, providing a novel insight for lung carcinoma treatment.

Circular RNA circ_0040823 inhibits the proliferation of acute myeloid leukemia cells and induces apoptosis by regulating miR-516b/PTEN

OBJECTIVE

Endogenous circular RNAs (circRNAs) and microRNAs (miRNAs) have been shown to regulate the pathogenesis of acute myeloid leukemia (AML). The current study aimed to identify the role of circRNA 0040823 (circ_0040823) in AML.

METHODS

Microarray datasets were analyzed to identify differentially expressed circRNAs in AML patients. Peripheral blood samples were obtained from healthy volunteers and AML patients for the measurement of circ_0040823 and miR-516b levels. The overexpression or knockdown of a target gene in AML cells was achieved by the transfection with lentiviral vectors or small interfering RNAs. BALB/c nude mice were inoculated with AML cells and monitored for tumor growth. Dual-luciferase reporter assay, RNA immunoprecipitation, and RNA pull-down assay were used to determine the binding relationship between circRNA and miRNA.

RESULTS

circ_0040823 was significantly downregulated in AML patients and leukemia cells. Overexpression of circ_0040823 inhibited AML cell proliferation, and induced apoptosis and cell cycle arrest. Upregulation of circ_0040823 also repressed the growth of xenograft tumors in vivo. circ_0040823 acted as a miR-516b sponge and regulated key cellular events in leukemia cells via downregulating miR-516b. Moreover, tumor suppressor phosphatase and tensin homolog (PTEN) was a downstream target of miR-516b. The inhibition of miR-516b impaired the proliferation capacity of leukemia cells and induced apoptosis, while PTEN deficiency attenuated these effects.

CONCLUSION

This study showed that circ_0040823 inhibited proliferation and induced apoptosis of AML cells by sponging miR-516b, thereby diminishing the regulatory effect of miR-516b on PTEN. These findings identified circ_0040823/miR-516b/PTEN as a new therapeutic target for AML.

High-throughput sequencing identified circular RNA circUBE2K mediating RhoA associated bladder cancer phenotype via regulation of miR-516b-5p/ARHGAP5 axis

Bladder cancer (BC) is known as a common and lethal urinary malignancy worldwide. Circular RNAs (circRNAs), an emerging non-coding RNA, participate in carcinogenesis process of several cancers including BC. In this study, high-throughput sequencing and RT-qPCR were applied to discover and validate abnormal high expression of circUBE2K in BC tissues. Fluorescence in situ hybridization (FISH) was used to detect hsa_circ_0009154 (circUBE2K) expression and subcellular localization in BC tissues. High circUBE2K predicted unfavorable prognoses in BCs, as well as correlated with clinical features. CCK8, transwell, EdU and wound healing assays demonstrated down-regulating circUBE2K decreased BC cell phenotype as proliferation, invasion, and migration, respectively. Further studies showed that circUBE2K promoted BC progression via sponging miR-516b-5p and enhancing ARHGAP5 expression through regulating RhoA activity. Dual-luciferase reporter, FISH and RNA pulldown assays were employed to verify the relationships among circUBE2K/miR-516b-5p/ARHGAP5/RhoA axis. Down-regulating miR-516b-5p or overexpressing ARHGAP5 restored RhoA activity mediated BC cell properties after silencing circUBE2K. Subcutaneous xenograft and metastasis model identified circUBE2K significantly increased BC cell metastasis and proliferation in-vivo. Taken together, we found that circUBE2K is a tumor-promoting circRNA in BC that functions as a ceRNA to regulate ARHGAP5 expression via sponging miR-516b-5p.

Circ_0006168 Promotes the Migration, Invasion and Proliferation of Esophageal Squamous Cell Carcinoma Cells via miR-516b-5p-Dependent Regulation of XBP1

Background

Circular RNAs (circRNAs) exert important roles in carcinogenesis. Here, we aimed to uncover the working mechanism of circ_0006168 in esophageal squamous cell carcinoma (ESCC) development.

Methods

Western blot assay and real-time quantitative polymerase chain reaction (RT-qPCR) were used to determine protein and RNA expression, respectively. Wound healing assay and transwell migration assay were performed to assess cell migration ability, whereas cell invasion ability was evaluated by transwell invasion assay. 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and colony formation assay were utilized to analyze cell proliferation ability. Xenograft tumor model was utilized to assess the role of X-box binding protein 1 (XBP1) in xenograft tumor growth in vivo. Dual-luciferase reporter assay, RNA immunoprecipitation (RIP) assay and RNA pull down assay were used to verify intermolecular interactions.

Results

XBP1 silencing suppressed the migration, invasion and proliferation of ESCC cells in vitro and restrained the xenograft tumor growth in vivo. MicroRNA-516b-5p (miR-516b-5p) interacted with the 3ʹ untranslated region (3ʹUTR) of XBP1 in ESCC cells. MiR-516b-5p overexpression inhibited the proliferation and motility of ESCC cells. MiR-516b-5p was a molecular target of circ_0006168 in ESCC cells. The interference of circ_0006168 restrained the motility and proliferation of ESCC cells. Circ_0006168 acted as miR-516b-5p sponge to up-regulate XBP1 expression in ESCC cells. MiR-516b-5p silencing or the accumulation of XBP1 largely rescued the proliferation ability and motility in circ_0006168-silenced ESCC cells.

Conclusion

In conclusion, circ_0006168 contributed to ESCC development through promoting the proliferation and motility of ESCC cells via mediating miR-516b-5p/XBP1 axis.

A multi-omics study on cutaneous and uveal melanoma

AIM

To present the multi-omics landscape of cutaneous melanoma (CM) and uveal melanoma (UM) from The Cancer Genome Atlas (TCGA).

METHODS

The differentially expressed genes (DEGs) between CM and UM were found and integrated into a gene ontology enrichment analysis. Besides, the differentially expressed miRNAs were also identified. We also compared the methylation level of CM with UM and identified the differentially methylated regions to integrate with the DEGs to display the relationship between the gene expression and DNA methylation. The differentially expressed transcription factors (TFs) were identified.

RESULTS

Though CM had more mutational burden than UM, they shared several similarities such as the same rankings in diverse variant types. Except GNAQ and GNA11, the other top 18 mutated genes of the combined group were mostly detected in CM instead of UM. On the transcriptomic level, 4610 DEGs were found and integrated into a gene ontology enrichment analysis. We also identified 485 differentially expressed miRNAs. The methylation analysis showed that UM had a significantly higher methylation level than CM. The integration of differentially methylated regions and DEGs demonstrated that most DEGs were downregulated in UM and the hypo- and hypermethylation presented no obvious difference within these DEGs. Finally, 116 hypermethylated TFs and 114 hypomethylated TFs were identified as differentially expressed TFs in CM when compared with UM.

CONCLUSION

This multi-omics study on comparing CM with UM confirms that they differ in all analyzed levels. Of notice, the results also offer new insights with implications for elucidating certain unclear problems such as the distinct role of epithelial mesenchymal transition in two melanomas, the different metastatic routes of CM and UM and the liver tropism of metastatic UM.

Circ_0079593 facilitates proliferation, metastasis, glucose metabolism and inhibits apoptosis in melanoma by regulating the miR-516b/GRM3 axis

Many studies confirm that circular RNA (circRNA) plays an important regulatory role in the malignant progression of cancer, including melanoma. However, the role of a novel circRNA, circ_0079593, in melanoma is unclear. The expression levels of circ_0079593 and miR-516b were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation was measured by cell counting kit-8 (CCK-8) assay, and cell migration and invasion were evaluated using transwell assay. Meanwhile, western blot (WB) analysis was employed to determine the levels of proliferation and metastasis-related proteins, as well as metabotropic glutamate receptor 3 (GRM3) protein. Furthermore, cell apoptosis was tested by detecting the cell apoptosis rate and Caspase-3 activity. The glucose consumption and lactate production of cells were measured to evaluate cell glucose metabolism. Moreover, dual-luciferase reporter assay and biotin-labeled RNA pull-down assay were used to confirm the interaction between miR-516b and circ_0079593 or GRM3. In addition, mice xenograft models were constructed to explore the effect of circ_0079593 on melanoma tumor growth in vivo. Our results discovered that circ_0079593 was highly expressed in melanoma, and its silencing suppressed melanoma cell proliferation, migration, invasion, glucose metabolism and promoted apoptosis. Moreover, we found that circ_0079593 could serve as a sponge of miR-516b, and miR-516b could target GRM3 in melanoma. The rescue experiments revealed that both miR-516b inhibitor and GRM3 overexpression could reverse the inhibition effect of circ_0079593 knockdown on melanoma progression. Additionally, in vivo experiments also revealed that circ_0079593 interference suppressed melanoma tumor growth. Our study concluded that circ_0079593 accelerated melanoma progression via upregulating GRM3 by sponging miR-516b, which suggested that circ_0079593 had the potential to be a new therapeutic biomarker for melanoma.

Dysregulated circRNA_100876 contributes to proliferation and metastasis of colorectal cancer by targeting microRNA-516b (miR-516b)

Colorectal cancer (CRC) is globally one of the most common malignant tumors. Increasing number of studies indicate that circular RNAs (circRNAs) play a significant role in the initiation and progression of CRC. However, the role of circRNA_100876 in CRC progression remains unclear. In this study, we investigated the expression and function of circRNA_100876 in CRC progression. The expression of circRNA_100876 and microRNA-516b (miR-516b) was compared in normal and CRC tissues using quantitative real-time polymerase chain reaction (RT-qPCR). In addition, proliferation, metastasis, and apoptosis of the cells were analyzed using Cell Counting Kit-8 (CCK-8) assay, Transwell assay, and flow cytometry, respectively. The relationship between circRNA_100876 and miR-516b was further verified using dual-luciferase reporter assay. Our data showed that circRNA_100876 was highly expressed in CRC tumor tissues, and the high expression gtransition (EMT)-related proteins. Furthermore, we found that the addition of miR-516b reversed the anti-tumor effect induced by the downregulation of circRNA_100876. In conclusion, this study revealed that circRNA_100876 is overexpressed in CRC tissues and represents a promising therapeutic target for CRC.

STAT1-induced upregulation of lncRNA LINC01123 predicts poor prognosis and promotes the progression of endometrial cancer through miR-516b/KIF4A

Long non-coding RNAs (lncRNAs) have been proposed as suppressors or promoters in many tumor processes. LncRNA LINC01123 (LINC01123) was a newly identified lncRNA which was firstly functionally analyzed in lung cancer. However, its expression and function in other tumor types were rarely reported. In this study, we firstly confirmed that LINC01123 was highly expressed in both endometrial cancer (EC) tissues and cell lines using bioinformatics analysis and RT-CPR. Then, we preliminarily analyzed the mechanisms involved in overexpression of LINC01123 in EC, finding that STAT1 could bind directly to the LINC01123 promoter region and activate its transcription. Clinical research with 106 patients indicated that high expression of LINC01123 was associated with advanced clinical progression and poor clinical outcome of EC patients. Functionally, knockdown of LINC01123 suppressed the proliferation, migration and invasion of EC cells, and promoted apoptosis. Mechanistically, we observed that LINC01123 may act as an endogenous sponge by competing for miR-516b, thereby regulating KIF4A. Overall, our study revealed a novel LINC01123/miR-516b/KIF4A pathway regulatory axis in EC pathogenesis. LINC01123 may be a novel prognostic biomarker and therapeutic target in EC.Abbreviations: EC: Endometrial cancer; LncRNA: Long non-coding RNA; EMT: epithelial-mesenchymal transition; miRNA: microRNA; qRT-PCR: Quantitative real-time polymerase chain reaction; SPSS: Statistical Package for Social Sciences; Chip: chromatin-immunoprecipitation, TCGA: The Cancer Genome Atlas; CCK-8: Cell Counting Kit-8; KIF4A: Chromosome-associated kinesin KIF4A.

MicroRNA-122-5p inhibits cell proliferation, migration and invasion by targeting CCNG1 in pancreatic ductal adenocarcinoma

Background

Pancreatic ductal adenocarcinoma (PDAC) is a lethal human malignancy, and previous researches support the contribution of microRNA (miRNA) to cancer progression. MiR-122-5p is reported to participate in the regulation of various cancers, while the function of miR-122-5p in PDAC remains unclear. In this study, we investigated the precise mechanism of miR-122-5p involved in PDAC pathogenesis.

Methods

The expression levels of miR-122-5p were detected in human PDAC tissues and cell lines by miRNA RT-PCR. The effects of miR-122-5p on cell proliferation were explored by MTT assays, colony formation assays and flow cytometry assays. The ability of migration and invasion was determined by transwell assays. Dual Luciferase reporter assay was performed to validate the direct interaction between miR-122-5p and its target gene. The related molecules of cell cycle, apoptosis and epithelial–mesenchymal transition (EMT) were examined with qRT-PCR and western blot. In addition, xenograft mouse models were applied to explore the effects of miR-122-5p in vivo.

Results

MiR-122-5p was underexpressed, while CCNG1 was highly expressed in PDAC tissues and cells. MiR-122-5p was negatively correlated with TNM stage, tumor size and lymph node metastasis in PDAC patients. Overexpression of miR-122-5p suppressed the proliferation, migration and invasion in vitro and inhibited tumorigenesis in vivo. Furthermore, CCNG1 was a direct target of miR-122-5p. Upregulated CCNG1 could partially reverse the effects caused by miR-122-5p. Moreover, miR-122-5p inhibited EMT through downregulation of CCNG1.

Conclusion

Overexpression of miR-122-5p could inhibit cell proliferation, migration, invasion, and EMT by downregulating CCNG1 in PDAC, suggesting a potential therapeutic target for PDAC.

Emerging Role of Non-Coding RNAs in Esophageal Squamous Cell Carcinoma

Esophageal squamous cell carcinoma (ESCC) is a highly prevalent tumor and is associated with ethnicity, genetics, and dietary intake. Non-coding RNAs (ncRNAs), specifically microRNAs (miRNAs), long ncRNAs (lncRNAs), and circular RNAs (circRNAs) have been reported as functional regulatory molecules involved in the development of many human cancers, including ESCC. Recently, several ncRNAs have been detected as oncogenes or tumor suppressors in ESCC progression. These ncRNAs influence the expression of specific genes or their associated signaling pathways. Moreover, interactions of ncRNAs are evident in ESCC, as miRNAs regulate the expression of lncRNAs, and further, lncRNAs and circRNAs function as miRNA sponges to compete with the endogenous RNAs. Here, we discuss and summarize the findings of recent investigations into the role of ncRNAs (miRNAs, lncRNAs, and circRNAs) in the development and progression of ESCC and how their interactions regulate ESCC development.

lncRNA LINC01494 Promotes Proliferation, Migration And Invasion In Glioma Through miR-122-5p/CCNG1 Axis

Background

Long noncoding RNAs (lncRNAs) are recognized as key effectors in tumor, including glioma. LINC01494 is an uncharacterized novel lncRNA. In this research, we aimed to investigate the function of LINC01494 in glioma.

Methods

Gene relative expression was analyzed by qRT-PCR method. CCK8, colony formation and Transwell assay was used to determine cell proliferation, migration and invasion. Bioinformatics analyses were used to predict the target of LINC01494 and miR-122-5p. Luciferase reporter assay was utilized to validate the interactions between LINC01494 and miR-122-5p or CCNG1 and miR-122-5p.

Results

LINC01494 was identified as a significantly upregulated lncRNA in glioma through bioinformatics analysis. Furthermore, LINC01494 upregulation indicated poor prognosis. Meanwhile, in vitro investigation indicated that silencing LINC01494 with siRNAs obviously inhibited the proliferation, cell cycle, migration and invasion of glioma cells. Besides, it is found that LINC01494 expression was negatively correlated with miR-122-5p. We demonstrated that LINC01494 inhibited miR-122-5p to upregulate CCNG1 expression through direct interaction. Rescue assay further demonstrated that LINC01494/miR-122-5p/CCNG1 signaling cascade plays a critical role in regulating glioma cell proliferation, migration and invasion.

Conclusion

Taken together, our findings demonstrated the essential function and molecular mechanism of LINC01494 in glioma progression.

SNHG8 is upregulated in esophageal squamous cell carcinoma and directly sponges microRNA-411 to increase oncogenicity by upregulating KPNA2

Background

The long noncoding RNA, small nucleolar RNA host gene 8 (SNHG8), is upregulated in multiple human cancer types. However, whether SNHG8 is aberrantly expressed in esophageal squamous cell carcinoma (ESCC) and its biological functions have yet to be elucidated. Thus, we aimed to determine the expression status of SNHG8 in ESCC, explore the effects of SNHG8 on the oncogenicity of ESCC, and investigate the potential underlying mechanisms.

Methods

SNHG8 expression in ESCC tissues and cell lines was determined via reverse-transcription quantitative polymerase chain reaction. The actions of SNHG8 on the malignant characteristics of ESCC were explored using CCK-8 assay, flow-cytometric analysis, Transwell migration and invasion assays, and tumor xenografts in nude mice.

Results

SNHG8 expression was significantly higher in ESCC tissues and cell lines. High SNHG8 expression was revealed to closely correlate with primary tumor invasion depth, lymph node metastases, TNM stage, and worse overall survival among patients with ESCC. Functional investigation showed that ablation of SNHG8 notably restricted ESCC cell proliferation, migration, and invasion while inducing apoptosis in vitro and hindered tumor growth in vivo. In the meantime, SNHG8 acted as a molecular sponge of microRNA-411 (miR-411) in ESCC. Furthermore, miR-411 exerted a tumor-suppressive effect on ESCC cells, and karyopherin alpha 2 (KPNA2) turned out to be a direct target gene of miR-411. Restoring KPNA2 expression neutralized the inhibitory effects of miR-411 overexpression on the malignant behaviors of ESCC cells. Moreover, silencing of miR-411 abrogated the influence of SNHG8 downregulation in ESCC cells.

Conclusion

SNHG8 may play oncogenic roles in the malignancy of ESCC by sponging miR-411 to increase KPNA2 expression. The SNHG8–miR-411–KPNA2 pathway may be a novel target for the treatment of patients with ESCC and offer potential biomarkers for the diagnosis and prognosis of ESCC.