Long Non-Coding RNA Differentiation Antagonizing Nonprotein Coding RNA (DANCR) Promotes Proliferation and Invasion of Pancreatic Cancer by Sponging miR-214-5p to Regulate E2F2 Expression

CircRNAs in Pancreatic Cancer: New Tools for Target Identification and Therapeutic Intervention

We have reviewed the literature for circular RNAs (circRNAs) with efficacy in preclinical pancreatic-cancer related in vivo models. The identified circRNAs target chemoresistance mechanisms (n=5), secreted proteins and transmembrane receptors (n=15), transcription factors (n=9), components of the signaling- (n=11), ubiquitination- (n=2), autophagy-system (n=2), and others (n=9). In addition to identifying targets for therapeutic intervention, circRNAs are potential new entities for treatment of pancreatic cancer. Up-regulated circRNAs can be inhibited by antisense oligonucleotides (ASO), small interfering RNAs (siRNAs), short hairpin RNAs (shRNAs) or clustered regularly interspaced short-palindromic repeats-CRISPR associated protein (CRISPR-CAS)-based intervention. The function of down-regulated circRNAs can be reconstituted by replacement therapy using plasmids or virus-based vector systems. Target validation experiments and the development of improved delivery systems for corresponding agents were examined.

New evidence for a role of DANCR in cancers: a comprehensive review

Cancer remains a leading cause of mortality and poses a substantial threat to public health. Studies have revealed that Long noncoding RNA DANCR is a cytoplasmic lncRNA whose aberrant expression plays a pivotal role in various cancer types. Within tumour biology, DANCR exerts regulatory control over crucial processes such as proliferation, invasion, metastasis, angiogenesis, inflammatory responses, cellular energy metabolism reprogramming, and apoptosis. By acting as a competitive endogenous RNA for miRNAs and by interacting with proteins and mRNAs at the molecular level, DANCR contributes significantly to cancer progression. Elevated DANCR levels have also been linked to heightened resistance to anticancer drugs. Moreover, the detection of circulating DANCR holds promise as a valuable biomarker for aiding in the clinical differentiation of different cancer types. This article offers a comprehensive review and elucidation of the primary functions and molecular mechanisms through which DANCR influences tumours.

DNM3OS Enhances the Apoptosis and Senescence of Spermatogonia Associated with Nonobstructive Azoospermia by Providing miR-214-5p and Decreasing E2F2 Expression

Background

Nonobstructive azoospermia (NOA) is a complex disease characterized by the spermatogenic dysfunction of testicular tissues. The roles played by long noncoding RNAs (lncRNAs) in NOA pathogenesis have not been extensively studied.

Methods

Microarray assays were performed on samples of testicular biopsy tissue obtained from patients with NOA for the purpose of identifying differentially expressed lncRNAs and messenger RNA (mRNA) transcripts, and the results were verified by quantitative real-time polymerase chain reaction. Mouse-derived GC-1 spermatogonia (spg) cells undergoing treatment with Adriamycin (ADR) were used to investigate the biological functions of the selected lncRNAs in vitro. The target microRNAs (miRNAs) of lncRNAs and the target mRNAs of miRNAs were predicted by a bioinformatics analysis. Functional studies performed using the CCK-8 assay, EdU incorporation assay, apoptosis detection, and senescence-associated β-galactosidase (SA-β-Gal) staining were conducted using GC-1 spg cells.

Results

Totals of 2,652 lncRNAs and 2,625 mRNAs were found to be differentially expressed in the testicular tissue of NOA patients when compared with patients in a control group. Dynamin 3 opposite strand (DNM3OS) was a provider of pe-miR-214-5p that positively regulates miR-214-5p expression in GC-1 spg cells. The E2 factor (E2F) family of transcription factor 2 (E2F2) was initially predicted and subsequently verified to be a downstream gene of miR-214-5p. E2F2 expression was upregulated after DNM3OS knockdown in ADR-treated GC-1 spg cells. Moreover, knockdown of either DNM3OS or miR-214-5p significantly alleviated ADR-induced decreases in cellular activity and proliferation, as well as increases in apoptosis and senescence of mouse spermatogonial GC-1 spg cells.

Conclusions

DNM3OS was found to regulate the apoptosis and senescence of spermatogonia by providing miR-214-5p and decreasing E2F2 expression, suggesting it as a novel target for gene therapy of male infertility.

miR-125b-5p, miR-155-3p, and miR-214-5p and Target E2F2 Gene in Oral Squamous Cell Carcinoma

It is known that E2F2 (E2F transcription factor 2) plays an important role as controller in the cell cycle. This study aimed to analyse the expression of the E2F2 gene and E2F2 protein and demonstrate E2F2 target microRNAs (miRNAs) candidates (miR-125b-5p, miR-155-3p, and miR-214-5p) in oral squamous cell carcinoma tumour and margin samples. The study group consisted 50 patients. The E2F2 gene and miRNAs expression levels were assessed by qPCR, while the E2F2 protein was assessed by ELISA. When analysing the effect of miRNAs expression on E2F2 gene expression and E2F2 protein level, we observed no statistically significant correlations. miR-125b-5p was downregulated, while miR-155-3p, and miR-214-5p were upregulated in tumour samples compared to margin. We observed a difference between the miR-125b-5p expression level in smokers and non-smokers in margin samples. Furthermore, HPV-positive individuals had a significantly higher miR-125b-5p and miR-214-5p expression level compared to HPV-negative patients in tumour samples. The study result showed that the E2F2 gene is not the target for analysed miRNAs in OSCC. Moreover, miR-155-3p and miR-125b-5p could play roles in the pathogenesis of OSCC. A differential expression of the analysed miRNAs was observed in response to tobacco smoke and HPV status.

The Emerging Role of RNA N6-Methyladenosine Modification in Pancreatic Cancer

Pancreatic cancer (PC) is one of the most common malignant cancers, ranking the seventh highest causes of cancer-related deaths globally. Recently, RNA N6-methyladenosine (m6A) is emerging as one of the most abundant RNA modifications in eukaryote cells, involved in multiple RNA processes including RNA translocation, alternative splicing, maturation, stability, and degradation. As reported, m6A was dynamically and reversibly regulated by its “writers”, “erasers”, and “readers”, Increasing evidence has revealed the vital role of m6A modification in the development of multiple types of cancers including PC. Currently, aberrant m6A modification level has been found in both PC tissues and cell lines. Moreover, abnormal expressions of m6A regulators and m6A-modified genes have been reported to contribute to the malignant development of PC. Here in this review, we will focus on the function and molecular mechanism of m6A-modulated RNAs including coding RNAs as well as non-coding RNAs. Then the m6A regulators will be summarized to reveal their potential applications in the clinical diagnosis, prognosis, and therapeutics of PC.

High Expression of Bloom Syndrome Helicase is a Key Factor for Poor Prognosis and Advanced Malignancy in Patients with Pancreatic Cancer: A Retrospective Study

BACKGROUND

Bloom syndrome helicase (BLM) is overexpressed in multiple types of cancers and its overexpression may induce genomic instability. This study aimed to determine the function of BLM expression in pancreatic cancer.

METHODS

BLM messenger RNA (mRNA) expression was analyzed using public datasets to determine its relationship with pancreatic cancer prognosis. Overall, 182 patients with pancreatic cancer who underwent radical resection at our institution were enrolled. BLM expression was evaluated by immunohistochemistry (IHC). We explored the effect of BLM on the proliferation, invasion, migration, and chemoresistance of pancreatic cancer cells via small-interfering RNAs and performed pathway analysis using gene set enrichment analysis.

RESULTS

BLM mRNA expression was higher in tumor tissue than in normal tissue and had a prognostic effect on overall survival (OS) and recurrence-free survival. The same results were validated by IHC. Multivariate analysis showed that high BLM expression was an independent poor prognostic factor for OS (hazard ratio [HR] 1.678, p = 0.029). In subgroup analysis, the effect of high BLM expression was more significant on OS in patients with younger age (HR 2.27, p = 0.006), male sex (HR 2.39, p = 0.002), high cancer antigen 19-9 level (HR 2.44, p = 0.001), advanced tumor stage (HR 2.25, p = 0.001), lymph node metastasis (HR 2.51, p = 0.001), nerve invasion (HR 2.07, p = 0.002), and adjuvant chemotherapy (HR 2.66, p < 0.001). In vitro, BLM suppression resulted in reduced tumor proliferation, invasion, migration, and chemoresistance. Mechanistically, BLM expression may be associated with E2F1 and E2F2.

CONCLUSION

BLM expression is a prognostic factor for patients with pancreatic cancer, especially in those with advanced malignancies and receiving chemotherapy.

The lncRNA DANCR promotes development of atherosclerosis by regulating the miR-214-5p/COX20 signaling pathway

BACKGROUND

Although long non-coding RNA differentiation antagonizing non-protein coding RNA (DANCR) has been reported to be involved in atherosclerosis (AS) development, its specific mechanism remains unclear.

METHODS

DANCR expression levels in blood samples of AS patients and oxidized low-density lipoprotein (ox-LDL) treated vascular smooth muscle cells (VSMCs) and human umbilical vein endothelial cells (HUVECs) were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The small interfering RNA targeting DANCR (si-DANCR) was used to silence DANCR expression. Cell viability was assessed by CCK-8 assay. Cell apoptosis was evaluated by flow cytometry. Levels of inflammatory cytokines, anti-oxidative enzyme superoxide dismutase (SOD) activity, and malonaldehyde (MDA) were detected by specific commercial kits. An animal AS model was established to confirm the role of DANCR/microR-214-5p/COX20 (the chaperone of cytochrome c oxidase subunit II COX2) in AS development.

RESULTS

DANCR was significantly increased in the blood samples of AS patients and ox-LDL treated VSMCs and HUVECs. DANCR downregulation obviously increased viability and reduced apoptosis of ox-LDL-treated VSMCs and HUVECs. Meanwhile, DANCR downregulation reduced the levels of inflammatory cytokines, including interleukin (IL)-6 (IL-6), IL-1beta (IL-1β), IL-6 and tumor necrosis factor (TNF)-alpha (TNF-α) and MDA while increasing the SOD level in ox-LDL-treated VSMCs and HUVECs. DANCR regulated COX20 expression by acting as a competing endogenous RNA (ceRNA) of miR-214-5p. Rescue experiments demonstrated that miR-214-5p downregulation obviously attenuated si-DANCR-induced protective effects on ox-LDL-caused endothelial injury.

CONCLUSIONS

Our results revealed that DANCR promoted AS progression by targeting the miR-214-5p/COX20 axis, suggesting that DANCR might be a potential therapeutic target for AS.

CircCUL2 suppresses retinoblastoma cells by regulating miR-214-5p/E2F2 Axis

The aim of this study was to investigate the effect of circCUL2 on the proliferation, invasion and migration of retinoblastoma cells by regulating the miR-214-5p/E2F2 axis. qRT-PCR and western blot were performed to detect the expressions of circCUL2, miR-214-5p and E2F2 in tumor tissues and adjacent normal tissues from retinoblastoma patients, and in normal human retinal epithelial cells ARPE-19 and human retinoblastoma cells Y79 and SO-Rb50. qRT-PCR and western blot were performed for the detection of RNA levels of circCUL2 and miR-214-5p and the mRNA and protein levels of E2F2, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay for cell proliferation ability, Transwell assay for cell invasion ability, and scratch assay for cell migration ability. Luciferase dual reporter assay was used to detect the targeting relationship between circCUL2 and miR-214-5p, and between miR-214-5p and E2F2. CircCUL2 and E2F2 were lowly expressed, while miR-214-5p was highly expressed in retinoblastoma tumor tissues and cells. Transfection with pcDNA3.1-CUL2 or miR-214-5p inhibitor inhibited the proliferation, invasion and migration of Y79 and SO-Rb50 cells compared with the negative control; while transfection with sh-CUL2 or miR-214-5p mimics promoted the proliferation, invasion and migration of Y79 and SO-Rb50 cells. CircCUL2 negatively regulated miR-214-5p, while miR-214-5p negatively regulated E2F2. Overexpression of miR-214-5p or silencing of E2F2 in SO-Rb50 cells partially reversed the inhibitory effect of circCUL2 on the proliferation, invasion and migration of retinoblastoma cells. CircCUL2 inhibited the proliferation, invasion and migration of retinoblastoma cells by regulating the miR-214-5p/E2F2 axis.

Prognostic Value of E2F Transcription Factor Expression in Pancreatic Adenocarcinoma

Background

Pancreatic adenocarcinoma (PAAD) is one of the deadliest types of cancer. In the early stages, patients often have atypical symptoms, making diagnosis difficult. The prognosis of diagnosed patients is very poor and treating PAAD is challenging. Therefore, determining reliable risk factors related to PAAD development is critical for improving patient prognosis. E2F family transcription factors (TFs) are essential regulators of DNA synthesis and cell cycle progression in eukaryotic cells, and they have been identified as prognostic biomarkers associated with multiple cancer types. However, further research is necessary to establish the prognostic relevance of these TFs in PAAD patients.

Material/Methods

We assessed PAAD patient transcriptional and outcome data using the TIMER, ONCOMINE, STRING, GEPIA, cBioPortal, Kaplan-Meier Plotter, GSCALite, and starBase databases.

Results

PAAD tumor tissues exhibited increased expression of E2F1/3/5/7/8 relative to that in normal tissues, while the expression of E2F2/3/6/8 was associated with a more advanced tumor stage. Survival analyses indicated that PAAD patients expressing higher levels of E2F1/2/3/7/8 exhibited shorter overall survival (OS) and disease-free survival (DFS) than patients expressing lower levels of these TFs. In addition, E2F4 and E2F6 overexpression was associated with poorer DFS and OS, respectively. We also found that the expression of E2Fs was significantly correlated with immune infiltrates, including CD8+ T cells, CD4+ T cells, B cells, dendritic cells, neutrophils, and macrophages.

Conclusions

Our study may provide new insights into the optimal choice of immunotherapy and promising novel targets for therapeutic intervention in PAAD patients.

Long non-coding RNA TMPO-AS1 promotes cell proliferation, migration, invasion and epithelial-to-mesenchymal transition in gallbladder carcinoma by regulating the microRNA-1179/E2F2 axis

Gallbladder carcinoma (GBC), which is a common tumor of the biliary system, poses a serious threat to human life and health. The present study aimed to investigate the molecular mechanism of the long non-coding (lnc)RNA thymopoietin antisense transcript 1 (TMPO-AS1)/microRNA (miRNA/miR)-1179/E2F transcription factor 2 (E2F2) axis in GBC. The viability, proliferation, migration, invasion and epithelial-to-mesenchymal transition (EMT) of GBC cell lines were assessed via the Cell Counting Kit-8, colony formation, Transwell migration and invasion, immunofluorescence and western blot assays. In the present study, lncRNA TMPO-AS1 was significantly upregulated in clinical GBC tissues and cell lines, and was highly expressed in stage III+IV patients with GBC compared with stage I+II patients with GBC. In addition, the overall survival rate of patients with low TMPO-AS1 expression levels was higher than those with high TMPO-AS1 expression levels. Furthermore, TMPO-AS1 knockdown inhibited the viability, proliferation, migration, invasion and EMT of GBC cell lines. In addition, miR-1179 expression was downregulated in clinical GBC tissues and cell lines, and negatively correlated with TMPO-AS1 expression. The results revealed that miR-1179 is a target of TMPO-AS1, which was confirmed via the dual-luciferase reporter assay and RNA pull-down analysis. Overexpression of miR-1179 inhibited the viability, proliferation, migration, invasion and EMT of GBC cell lines. Furthermore, E2F2 was verified as a direct target of miR-1179 by binding to its 3'-untranslated region. E2F2 expression was significantly upregulated in clinical GBC tissues and cell lines, and negatively correlated with miR-1179 expression. Notably, E2F2 knockdown partially hindered the effects of TMPO-AS1/miR-1179 on the proliferation and metastasis of GBC cell lines. Taken together, the results of the present study suggest that TMPO-AS1 potentially plays a tumor-promoting role in the occurrence and development of GBC, which may be achieved by regulating the miR-1179/E2F2 axis.

LncRNA FTX promotes the malignant progression of colorectal cancer by regulating the miR-214-5p-JAG1 axis

Background

Long non-coding RNAs (lncRNAs) have recently been found to be vital regulators of various cancers, including colorectal cancer (CRC). It has been previously reported that the dysregulated expression of lncRNA Five prime to Xist (FTX) is involved in carcinogenesis. However, the role of lncRNA FTX in the progression of CRC is still unclear.

Methods

Fluorescence in situ hybridization (FISH) was used to detect the expression of lncRNA FTX and miR-214-5p in CRC tissues. Cell Counting Kit-8 assay, transwell assay, wound-healing assay, and proliferation assay were used to explore the function of lncRNA FTX in CRC cells. Quantitative real-time polymerase chain reaction (qRT-PCR), western blotting, and luciferase reporter assay were used to confirm the relationship between lncRNA FTX and miR-214-5p-jagged canonical Notch ligand 1 (JAG1). We further explored the role of lncRNA FTX in vivo using xenograft tumor assay.

Results

lncRNA FTX was found to be upregulated in CRC tissues by FISH. The downregulation of endogenous lncRNA FTX expression inhibited CRC cell proliferation, migration, and invasion. Mechanistically, lncRNA FTX sequestered miR-214-5p and thus released its repression on JAG1, driving the malignant progression of CRC.

Conclusions

These findings give rise to a new perspective, the lncRNA FTX-miR-214-5p-JAG1 regulatory axis, in exploring the cancer-promoting mechanism of lncRNA FTX in CRC.

Long Non-coding RNA DANCR in Cancer: Roles, Mechanisms, and Implications

Long non-coding RNA (lncRNA) DANCR (also known as ANCR)—differentiation antagonizing non-protein coding RNA, was first reported in 2012 to suppress differentiation of epithelial cells. Emerging evidence demonstrates that DANCR is a cancer-associated lncRNA abnormally expressed in many cancers (e.g., lung cancer, gastric cancer, breast cancer, hepatocellular carcinoma). Increasing studies suggest that the dysregulation of DANCR plays critical roles in cancer cell proliferation, apoptosis, migration, invasion, and chemoresistance in vitro and tumor growth and metastasis in vivo. Mechanistic analyses show that DANCR can serve as miRNA sponges, stabilize mRNAs, and interact with proteins. Recent research reveals that DANCR can be detected in many body fluids such as serum, plasma, and exosomes, providing a quick and convenient method for cancer monitor. Thus DANCR can be used as a promising diagnostic and prognostic biomarker and therapeutic target for various types of cancer. This review focuses on the role and mechanism of DANCR in cancer progression with an emphasis on the clinical significance of DANCR in human cancers.

Comprehensive Analysis of the Expression and Prognosis for E2Fs in Human Clear Cell Renal Cell Carcinoma

Background

E2F transcription factors is a family of transcription factors, and lots of studies have shown that they play a key role in the occurrence and development of many tumors. However, the association between expression, prognostic value, and immune infiltration in the tumor microenvironment of the eight E2Fs members in ccRCC is still unclear.

Method

s. We used online databases, such as ONCOMINE, UALCAN, Kaplan–Meier plotter, GEPIA, Metascape, TIMER, and cBioPortal, to analyze the effect of mRNA expression of E2Fs family members in ccRCC on the prognosis of patients and the relationship with immune infiltration.

Results

Except for E2F5, other seven members of the family of E2Fs mRNA expression levels in ccRCC tissues were significantly higher than control tissues. And the high expression of E2Fs mRNA in ccRCC patients was related to cancer stage and tumor grade. Survival analysis results suggested that elevated mRNA expression levels of E2F1/2/3/4/7/8 were significantly related to the shorter overall survival (OS) in ccRCC patients (P = 3.9E – 06), while high mRNA expression of E2F6 is not related to OS (P = 0.061). Mutations of E2Fs were correlated with shorter OS of ccRCC patients (P = 7.094E – 5). In addition, mRNA expression of E2F1/2/3/4/7/8 was positively correlated with infiltration of six types of immune cells, including B cells, CD8+ T cells, CD4+ T cells, macrophages, neutrophils, and dendritic cells.

Conclusions

These results indicate that E2F1/2/3/4/7/8 may be used as a prognostic marker for the survival of ccRCC patients and laid the foundation for studying the immune infiltration role of E2Fs family members in tumors.

Krüppel-like factor 5-induced overexpression of long non-coding RNA DANCR promotes the progression of cervical cancer via repressing microRNA-145-3p to target ZEB1

Long non-coding RNA (lncRNA) differentiation antagonizing non-protein coding RNA (DANCR) participates in the development of diverse cancers. Nevertheless, the impact of DANCR on cervical cancer (CC) remains largely unknown. This study aims to explore the effects of DANCR sponging microRNA-145-3p (miR-145-3p) on CC. Expression of KLF5, DANCR, miR-145-3p, and zinc finger E-box binding homeobox 1 (ZEB1) in CC and adjacent normal tissues was determined. Human CC cell lines were, respectively, treated with silenced DANCR or miR145-3p mimic/inhibitor. Then, the viability, migration, invasion, and apoptosis of CC cells were measured. The cell growth in vivo was observed as well. Chromatin immunoprecipitation assay was performed to analyze the binding of KLF5 and DANCR promoter. Interaction among DANCR, miR-145-3p, and ZEB1 was assessed. KLF5, DANCR, and ZEB1 were upregulated but miR-145-3p was downregulated in CC tissues. KLF5 activated DANCR expression and the high DANCR expression was related to tumor staging, infiltrating muscle depth and lymphatic metastasis of CC patients. Reduced DANCR or elevated miR-145-3p repressed malignant behaviors of CC cells. The tumor diameter and weight were also repressed by DANCR silencing or miR-145-3p elevation. The effect of DANCR knockdown on CC cells could be reversed by miR-145-3p inhibitor. MiR-145-3p was targeted by DANCR and ZEB1 was targeted by miR-145-3p. KLF5-induced overexpression of DANCR promotes CC progression via suppressing miR-145-3p to target ZEB1. This study may provide potential targets for CC treatment.

Long noncoding RNAs: role and contribution in pancreatic cancer

Noncoding RNAs are proclaimed to be expressed in various cancer types and one such type is found to be pancreatic ductal adenocarcinoma (PDAC). The long noncoding RNAs (LncRNAs) affect the migration, invasion, and growth of tumor cells by playing important roles in the process of epigenesis, post-transcription, and transcriptional regulation along with the maintenance of apoptosis and cell cycle. It is quite subtle whether the alterations in lncRNAs would impact PDAC progression and development. This review throws a spotlight on the lncRNAs associated with tumor functions: MALAT-1, HOTAIR, HOXA13, H19, LINC01559, LINC00460, SNHG14, SNHG16, DLX6-AS1, MSC-AS1, ABHD11-AS1, DUXAP8, DANCR, XIST, DLEU2, etc. are upregulated lncRNAs whereas GAS5, HMlincRNA717, MIAT, LINC01111, lncRNA KCNK15-AS1, etc. are downregulated lncRNAs inhibiting the invasion and progression of PDAC. These data provided helps in the assessment of lncRNAs in the development, metastasis, and occurrence of PDAC and also play a vital role in the evolution of biomarkers and therapeutic agents for the treatment of PDAC.

Low miR-214-5p Expression Correlates With Aggressive Subtypes of Pediatric ALCL With Non-Common Histology

The unsatisfactory cure rate of relapsing ALK-positive Anaplastic Large-Cell Lymphoma (ALCL) of childhood calls for the identification of new prognostic markers. Here, the small RNA landscape of pediatric ALK-positive ALCL was defined by RNA sequencing. Overall, 121 miRNAs were significantly dysregulated in ALCL compared to non-neoplastic lymph nodes. The most up-regulated miRNA was miR-21-5p, whereas miR-19a-3p and miR-214-5p were reduced in ALCL. Characterization of miRNA expression in cases that relapsed after first line therapy disclosed a significant association between miR-214-5p down-regulation and aggressive non-common histology. Our results suggest that miR-214-5p level may help to refine the prognostic stratification of pediatric ALK-positive ALCL.

Mechanisms of circular RNA circ_0066147 on pancreatic cancer progression

Background

The purpose of the study was to explore the precise parts of circ_0066147 (circular RNA [circRNA] scm-like with four mbt domains 1, circSFMBT1) in pancreatic cancer (PC) progression.

Methods

Ribonuclease R assay was used to confirm the stability of circ_0066147. circ_0066147, miR-326 and E2F transcription factor 2 (E2F2) expression levels was detected by quantitative reverse-transcription polymerase chain reaction or Western blot. Cell proliferation, apoptosis, migration and invasion abilities were assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide, flow cytometry, wound-healing and transwell assays, respectively. Targeted relationships among circ_0066147, miR-326 and E2F2 were verified by the dual-luciferase reporter or RNA pull-down assay.

Results

circ_0066147 expression was upregulated in PC tissues and cells. circ_0066147 knockdown inhibited PC cell proliferation, migration, invasion and enhanced apoptosis in vitro, as well as weakened tumor growth in vivo. Mechanistically, circ_0066147 directly targeted miR-326 and circ_0066147 modulated E2F2 expression by miR-326. miR-326 mediated the regulation of circ_0066147 in PC cell behaviors in vitro. Furthermore, E2F2 was a functional target of miR-326 in modulating PC cell behaviors in vitro.

Conclusion

circ_0066147 regulated PC malignant progression in part depending on the miR-326/E2F2 axis, illuminating circ_0066147 was a potential prognostic marker and therapeutic target for PC management.

miR-214-5p targeted by LncRNA DANCR mediates TGF-β signaling pathway to accelerate proliferation, migration and inhibit apoptosis of prostate cancer cells

OBJECTIVE

This research was designed to probe into the regulatory mechanism of long non-coding RNA (LncRNA) differentiation antagonizing non-protein coding RNA (DANCR) in potential applications and molecular mechanisms of prostate carcinoma (PC).

METHODS

The DANCR and miR-214-5p levels in PC tissues and cell lines were tested via real-time PCR, and those of transforming growth factor-β (TGF-β) signaling pathway related proteins were evaluated via Western Blot (WB). Cell proliferation, migration, apoptosis and the regulatory relationship between target genes were assessed via MTT method, scratch test, flow cytometry, dual-luciferase report, RNA co-immunoprecipitation and RNA pull-down test, respectively.

RESULTS

DANCR was up-regulated in PC patients' serum and cell lines, while miR-214-5p was opposite, showing negative correlation. Besides, DANCR was significantly correlated with PSA, Gleason score and T stage in PC patients. The area under the curve (AUC) of DANCR and miR-214-5p for diagnosing PC was not less than 0.850, while the AUC for predicting poor prognosis was more than 0.800. Cox analysis results also revealed that the two might be prognostic indicators of PC patients. We found that DANCR high levels or miR-214-5p low levels were related to PC patients' poor prognosis. Up-regulating DANCR or down-regulating miR-214-5p could promote PC cells' malignant proliferation and migration, prevent apoptosis, and activate TGF-β signaling pathway, while reverse treatment of DANCR or miR-214-5p can reverse the above results. DANCR regulates miR-214-5p in a targeted manner, and DANCR over-expression can reduce the cancer inhibitory effect of miR-214-5p on PC cells.

CONCLUSION

DANCR-miR-214-5p-TGF-β axis regulatory network plays a key regulatory part in PC progression. It may provide new strategies for the screening and treatment of patients.

Comprehensive Analysis of Prognostic and Immune Infiltrates for E2F Transcription Factors in Human Pancreatic Adenocarcinoma

Background

E2F transcription factors (E2Fs) are a group of genes encoding a family of transcription factors in higher eukaryotes. They are involved in a variety of cellular functions and are up-regulated in many tissues and organs. However, the expression level, genetic variation, molecular mechanism, and biological function of different E2Fs in PAAD and its relationship with the prognosis and immune infiltration in patients with PAAD have not been fully elucidated.

Methods

In this study, we investigated the mRNA expression level, genetic variation, prognostic value and gene–gene interaction network of E2Fs in PAAD using the Oncomine, GEPIA, Kaplan Meier plotter, cBioPortal, GeneMANIA, STRING and Metascape database. Then, the relationship between E2Fs expression and tumor immune invasion was studied by using the TIMER database. Finally, we confirmed the expression of E2Fs in PAAD by IHC.

Results

The transcription levels of E2F1/3/5/8 are obviously up-regulated in PAAD and the high expression of E2F2/3/6/8 was apparently associated with the tumor stage of patients with PAAD. The abnormal expression of E2F1/2/3/4/5/7/8 in PAAD patients is related to the clinical outcome of PAAD patients. We also found that PAAD tissues have higher expression levels of E2F1/3/5/8 compared with adjacent normal tissues. The function of E2Fs and its neighboring genes is mainly related to the transcription initiation of the RNA polymerase II promoter. The functions of E2Fs and its neighboring proteins are mainly related to cell cycle, virus carcinogenesis, FoxO signaling pathway, TGF-β signaling pathway, transcriptional disorders in cancer and Wnt signaling pathway. We also found that the expression of E2Fs was significantly correlated with immune infiltrates, including B cells, CD8+ T cells, CD4+T cells, neutrophils, macrophages, and dendritic cells.

Conclusions

Our study may provide new insights into the choice of immunotherapy targets and prognostic biomarkers in PAAD patients.

The functional roles of long noncoding RNA DANCR in Human Cancers

Long noncoding RNAs (lncRNAs) have been wildly explored in various cellular processes and their aberrant expression could lead to tumorigenesis, development and progression. Differentiation antagonizing non-protein coding RNA (DANCR), a well-known lncRNA that is aberrant expression in various tumors, including hepatocellular carcinoma, gastric cancer, colorectal cancer, breast cancer, lung cancer and glioma and so on, in which it functions as oncogene mainly, contributing to cancer development and progression. High expressed DANCR is correlated with poor prognosis. In the present review, we summarize recent progression concerning the role, potential clinical utilities and underlying molecular mechanisms of DANCR related to occurrence and development of multiple cancers.

Long Non-Coding Small Nucleolar RNA Host Genes (SNHGs) in Endocrine-Related Cancers

Long non-coding RNAs (lncRNAs) are emerging regulators of a diverse range of biological processes through various mechanisms. Genome-wide association studies of tumor samples have identified several lncRNAs, which act as either oncogenes or tumor suppressors in various types of cancers. Small nucleolar RNAs (snoRNAs) are predominantly found in the nucleolus and function as guide RNAs for the processing of transcription. As the host genes of snoRNAs, lncRNA small nucleolar RNA host genes (SNHGs) have been shown to be abnormally expressed in multiple cancers and can participate in cell proliferation, tumor progression, metastasis, and chemoresistance. Here, we review the biological functions and emerging mechanisms of SNHGs involved in the development and progression of endocrine-related cancers including thyroid cancer, breast cancer, pancreatic cancer, ovarian cancer and prostate cancer.

DANCR: an emerging therapeutic target for cancer

The discovery of long non-coding RNAs (lncRNAs) revolutionized the current framework for understanding the molecular mechanisms of tumorigenesis and stimulated the search for targeted cancer treatments. Among lncRNAs, differentiation antagonizing non-protein-coding RNA (DANCR) is a newly identified oncogenic gene that is upregulated in diverse cancer types and has a critical role in cancer progression. Herein, we summarize current knowledge regarding DANCR regulatory functions related to cancer cell proliferation, invasion, metastasis, and chemo-resistance. We also synthesize the effects of DANCR on cancer stemness features, the epithelial-mesenchymal transition (EMT), and angiogenesis, which are essential for the progression of malignant cancer cells. Mechanically, the interaction between DANCR and its targets including microRNAs (miRNAs), mRNAs, and proteins are also elucidated. Finally, we propose DANCR-based therapeutic approaches to provide novel insights about cancer treatment.

MiR-214-3p exacerbates kidney damages and inflammation induced by hyperlipidemic pancreatitis complicated with acute renal injury

AIMS

Acute pancreatitis (AP) is usually complicated with multiple organ insufficiency, including renal injury. Hyperlipidemia is regarded as a risk factor to induce AP. High-fat diet-induced hyperlipidemic pancreatitis (HP) increased nowadays and showed more severe symptoms and complications than other AP. However, detailed mechanisms or mediators involved in HP complicated with acute renal injury were less studied. Here, we aimed to study how miR-214 expresses in the HP and whether miR-214 has functions to regulate pathological kidney damages induced by HP.

MAIN METHODS

Sprague-Dawley rats were adopted to establish HP model complicated with acute renal injury through long-term high-fat diet and sodium taurocholic injection. Models were injected with LV-rno-miR-214-3p or LV-anti-rno-miR-214-3p to exogenously regulate miR-214-3p to study its impacts on HP via a series of molecular and histological experiments.

KEY FINDINGS

MiR-214-3p was found to be up-regulated in the kidney, pancreas and serum of HP rats and also could intensify the pathological alterations, kidney and pancreas damages and fibrosis induced by HP. Inflammatory response in HP was enhanced when miR-214-3p was overexpressed. Besides, miR-214-3p up-regulation was showed to inhibit PTEN expression but increased P-Akt levels in the HP kidney, which might be a possible mechanism to induce severe symptoms of pancreatitis. Knockdown of miR-214-3p showed opposite effects.

SIGNIFICANCE

MiR-214-3p is indicated to exacerbate the tissue damages and inflammatory response caused by HP complicated with acute renal injury, which may provide a novel therapeutic perspective targeting miR-214-3p to treat HP with acute renal injury.

Long Non-coding RNA DANCR as an Emerging Therapeutic Target in Human Cancers

Long noncoding RNAs (lncRNAs) are emerging as important regulators of numerous biological processes, especially in cancer development. Aberrantly expressed and specifically located in tumor cells, they exert distinct functions in different cancers via regulating multiple downstream targets such as chromatins, RNAs, and proteins. Differentiation antagonizing non-protein coding RNA (DANCR) is a cytoplasmic lncRNA that generally works as a tumor promoter. Mechanically, DANCR promotes the functions of vital components in the oncogene network by sponging their corresponding microRNAs or by interacting with various regulating proteins. DANCR's distinct expression in tumor cells and collective involvement in pro-tumor pathways make it a promising therapeutic target for broad cancer treatment. Herein, we summarize the functions and molecular mechanism of DANCR in human cancers. Furthermore, we introduce the use of CRISPR/Cas9, antisense oligonucleotides and small interfering RNAs as well as viral, lipid, or exosomal vectors for onco-lncRNA targeted treatment. Conclusively, DANCR is a considerable promoter of cancers with a bright prospect in targeted therapy.

Long noncoding RNA FLVCR1-AS1 aggravates biological behaviors of glioma cells via targeting miR-4731-5p/E2F2 axis

Long noncoding RNAs (lncRNAs) display essential roles in cancer progression. FLVCR1-AS1 is a rarely investigated lncRNAs involved in various human cancers, such as hepatocellular carcinoma and lung cancer. However, its function in glioma has not been clarified. In our study, we found that FLVCR1-AS1 was highly expressed in glioma tissues and cell lines. And upregulation of FLVCR1-AS1 predicted poor prognosis in patients with glioma. Moreover, FLVCR1-AS1 knockdown inhibited proliferation, migration and invasion of glioma cells. Through bioinformatics analysis, we identified that FLVCR1-AS1 was a sponge for miR-4731-5p to upregulate E2F2 expression. Moreover, rescue assays indicated that FLVCR1-AS1 modulated E2F2 expression to participate in glioma progression. Altogether, our research demonstrates that the FLVCR1-AS1/miR-4731-5p/E2F2 axis is a novel signaling in glioma and may be a potential target for tumor therapy.