The miR-1224-5p/ELF3 Axis Regulates Malignant Behaviors of Pancreatic Cancer via PI3K/AKT/Notch Signaling Pathways

E74-like ETS transcription factor 3 expression and regulation in human intervertebral disc

Background

Intervertebral disc degeneration (IVDD) is one of the main causes of chronic low back pain. The degenerative process is often initiated by an imbalance between catabolic and anabolic pathways. Despite the large socio-economic impact, the initiation and progress of disc degeneration are poorly understood. Although intervertebral disc (IVD) and articular joint are not identical, their degenerative roads are remarkably similar. We, and another authors, previously demonstrated that E-74-like factor 3 (ELF3), a transcription factor induced by inflammatory mediators in various cell types including chondrocytes, is a central contributing factor for cartilage degradation. Thus, we aim to explore, for the first time, the expression, modulation, and the role of ELF3 in human IVD cells.

Methods

The presence of ELF3 in healthy and degenerated IVD tissues was initially determined by immunohistochemistry in annulus fibrosus (AF) and nucleus pulposus (NP). mRNA and protein expression were measured, respectively, by RT-qPCR and Western blot in AF and NP IVD cells harvested from healthy individuals and IVDD patients. Overexpression of ELF3 was performed by transfection of AF IVDD cells with pESE-1: ELF3 expression vector or pCI: empty vector.

Results

Our results unveiled, for the first time, the expression of ELF3 in IVD tissues. ELF3 is notably upregulated in degenerated tissues compared to those from healthy patients. In addition, the stimulation of IVDD AF cells with various proinflammatory stimuli, showed marked increase in both mRNA and protein expression of ELF3. ELF3 overexpression in AF IVDD cells resulted in the upregulation of proinflammatory and catabolic genes such as PTGS2, NOS2, LCN2, IL-6, MMP13, and ADAMTS-5; whereas, ELF3 silencing resulted in the opposite results.

Conclusions

Our results support a novel role for ELF3 as a pro-inflammatory and pro-catabolic transcriptional mediator, whose targeting in IVD tissues might be of potential therapeutic relevance in disc degeneration.

The function of the ELF3 gene and its mechanism in cancers

E74-like factor 3 (ELF3) is an important member of the E-twenty-six (ETS) transcription factor family. ELF3 is expressed in various types of cells and regulates a variety of biological behaviors, such as cell proliferation, differentiation, apoptosis, migration, and invasion, by binding to DNA to regulate the expression of other genes. In recent years, studies have shown that ELF3 plays an important role in the occurrence and development of many tumors and inflammation and immune related diseases. ELF3 has different functions and expression patterns in different tumors; it can function as a tumor suppressor gene or an oncogene, highlighting its dual effects of tumor promotion and inhibition. ELF3 also affects the levels of tumor immunity-related cytokines and is involved in the regulation and expression of multiple signaling pathways. In tumor therapy, ELF3 is a complex and multifunctional gene and has become a key focus of targeted treatment research. An in-depth study of the biological function of ELF3 can help to elucidate its role in biological processes and provide ideas and a basis for the development and clinical application of ELF3-related therapeutic methods. This review introduces the structure and physiological and cellular functions of the ELF3 gene, summarizes the mechanisms of action of ELF3 in different types of malignant tumors and its role in immune regulation, inflammation, etc., and discusses treatment methods for ELF3-related diseases, providing significant reference value for scholars studying the ELF3 gene and related diseases.

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.

Circ_0000115 Protects Against Cerebral Ischemia Injury by Suppressing Neuronal Apoptosis, Oxidative Stress and Inflammation by miR-1224-5p/Nos3 Axis In Vitro

Cerebral ischemia is a severe neurological disability related to neuronal apoptosis and cellular stress response. Circular RNAs (circRNAs) are emerging regulators of cerebral ischemia. Herein, this study proposed to probe the action of circ_0000115 in cerebral ischemia injury. The mouse neuroblastoma cells N2a and HT22 underwent oxygen-glucose deprivation (OGD) were used as a model of in vitro cerebral ischemia. Levels of genes and proteins were detected by qRT-PCR and western blotting. Cell proliferation and apoptosis were determined by EdU assay and flow cytometry. Western blotting was used to detect the protein level of pro-inflammatory factors. The oxidative stress injury was evaluated by detecting reactive oxygen species (ROS), malondialdehyde (MDA) and superoxide dismutase (SOD) generation. Dual-luciferase reporter and RIP assays were used to confirm the target relationship between miR-1224-5p and circ_0000115 or nitric oxide synthase 3 (NOS3). OGD exposure decreased circ_0000115 and NOS3 expression, and increased miR-1224-5p in N2a and HT22 cells in a time-dependent manner. Circ_0000115 silencing attenuated OGD-induced apoptosis, oxidative stress and inflammation in N2a and HT22 cells. Mechanistically, circ_0000115 directly sponged miR-1224-5p, which targeted NOS3. Furthermore, rescue experiments showed that miR-1224-5p overexpression abolished the neuroprotective effect of circ_0000115 in N2a and HT22 cells under OGD treatment. Besides that, silencing of miR-1224-5p protected N2a and HT22 cells against OGD-evoked injury, which was counteracted by NOS3 knockdown. Circ_0000115 protects N2a and HT22 cells against OGD-evoked neuronal apoptosis, inflammation, and oxidative stress via the miR-1224-5p/NOS3 axis, providing an exciting view of the pathogenesis of cerebral ischemia.

Functional characteristics of DNA N6-methyladenine modification based on long-read sequencing in pancreatic cancer

Abnormalities of DNA modifications are closely related to the pathogenesis and prognosis of pancreatic cancer. The development of third-generation sequencing technology has brought opportunities for the study of new epigenetic modification in cancer. Here, we screened the N6-methyladenine (6mA) and 5-methylcytosine (5mC) modification in pancreatic cancer based on Oxford Nanopore Technologies sequencing. The 6mA levels were lower compared with 5mC and upregulated in pancreatic cancer. We developed a novel method to define differentially methylated deficient region (DMDR), which overlapped 1319 protein-coding genes in pancreatic cancer. Genes screened by DMDRs were more significantly enriched in the cancer genes compared with the traditional differential methylation method (P < 0.001 versus P = 0.21, hypergeometric test). We then identified a survival-related signature based on DMDRs (DMDRSig) that stratified patients into high- and low-risk groups. Functional enrichment analysis indicated that 891 genes were closely related to alternative splicing. Multi-omics data from the cancer genome atlas showed that these genes were frequently altered in cancer samples. Survival analysis indicated that seven genes with high expression (ADAM9, ADAM10, EPS8, FAM83A, FAM111B, LAMA3 and TES) were significantly associated with poor prognosis. In addition, the distinction for pancreatic cancer subtypes was determined using 46 subtype-specific genes and unsupervised clustering. Overall, our study is the first to explore the molecular characteristics of 6mA modifications in pancreatic cancer, indicating that 6mA has the potential to be a target for future clinical treatment.

The roles of lncRNAs and miRNAs in pancreatic cancer: a focus on cancer development and progression and their roles as potential biomarkers

Pancreatic ductal adenocarcinoma (PDAC) is among the most penetrative malignancies affecting humans, with mounting incidence prevalence worldwide. This cancer is usually not diagnosed in the early stages. There is also no effective therapy against PDAC, and most patients have chemo-resistance. The combination of these factors causes PDAC to have a poor prognosis, and often patients do not live longer than six months. Because of the failure of conventional therapies, the identification of key biomarkers is crucial in the early diagnosis, treatment, and prognosis of pancreatic cancer. 65% of the human genome encodes ncRNAs. There are different types of ncRNAs that are classified based on their sequence lengths and functions. They play a vital role in replication, transcription, translation, and epigenetic regulation. They also participate in some cellular processes, such as proliferation, differentiation, metabolism, and apoptosis. The roles of ncRNAs as tumor suppressors or oncogenes in the growth of tumors in a variety of tissues, including the pancreas, have been demonstrated in several studies. This study discusses the key roles of some lncRNAs and miRNAs in the growth and advancement of pancreatic carcinoma. Because they are involved not only in the premature identification, chemo-resistance and prognostication, also their roles as potential biomarkers for better management of PDAC patients.

Detailed role of microRNA-mediated regulation of PI3K/AKT axis in human tumors

The regulation of signal transmission and biological processes, such as cell proliferation, apoptosis, metabolism, migration, and angiogenesis are greatly influenced by the PI3K/AKT signaling pathway. Highly conserved endogenous non-protein-coding RNAs known as microRNAs (miRNAs) have the ability to regulate gene expression by inhibiting mRNA translation or mRNA degradation. MiRNAs serve key role in PI3K/AKT pathway as upstream or downstream target, and aberrant activation of this pathway contributes to the development of cancers. A growing body of research shows that miRNAs can control the PI3K/AKT pathway to control the biological processes within cells. The expression of genes linked to cancers can be controlled by the miRNA/PI3K/AKT axis, which in turn controls the development of cancer. There is also a strong correlation between the expression of miRNAs linked to the PI3K/AKT pathway and numerous clinical traits. Moreover, PI3K/AKT pathway-associated miRNAs are potential biomarkers for cancer diagnosis, therapy, and prognostic evaluation. The role and clinical applications of the PI3K/AKT pathway and miRNA/PI3K/AKT axis in the emergence of cancers are reviewed in this article.

Discovery of Transcription Factors Involved in the Maintenance of Resident Vascular Endothelial Stem Cell Properties

A resident vascular endothelial stem cell (VESC) population expressing CD157 has been identified recently in mice. Herein, we identified transcription factors (TFs) regulating CD157 expression in endothelial cells (ECs) that were associated with drug resistance, angiogenesis, and EC proliferation. In the first screening, we detected 20 candidate TFs through the CD157 promoter and gene expression analyses. We found that 10 of the 20 TFs induced CD157 expression in ECs. We previously reported that 70% of CD157 VESCs were side population (SP) ECs that abundantly expressed ATP-binding cassette (ABC) transporters. Here, we found that the 10 TFs increased the expression of several ABC transporters in ECs and increased the proportion of SP ECs. Of these 10 TFs, we found that six (Atf3, Bhlhe40, Egr1, Egr2, Elf3, and Klf4) were involved in the manifestation of the SP phenotype. Furthermore, the six TFs enhanced tube formation and proliferation in ECs. Single-cell RNA sequence data in liver ECs suggested that Atf3 and Klf4 contributed to the production of CD157+ VESCs in the postnatal period. We concluded that Klf4 might be important for the development and maintenance of liver VESCs. Our work suggests that a TF network is involved in the differentiation hierarchy of VESCs.

Tumoral Intraductal Neoplasms of the Bile Ducts Comprise Morphologically and Genetically Distinct Entities

CONTEXT.—

Tumoral (grossly visible) intraductal neoplasms of the bile ducts are still being characterized.

OBJECTIVE.—

To investigate their morphologic, immunohistochemical, and molecular features.

DESIGN.—

Forty-one cases were classified as gastric-, intestinal-, pancreatobiliary-type intraductal papillary neoplasm (IPN), intraductal oncocytic papillary neoplasm (IOPN), or intraductal tubulopapillary neoplasm (ITPN) on the basis of histology. All neoplasms were subjected to targeted next-generation sequencing.

RESULTS.—

The mean age at diagnosis was 69 years (42-81 years); male to female ratio was 1.3. Most neoplasms (n = 23, 56%) were extrahepatic/large (mean size, 4.6 cm). The majority (n = 32, 78%) contained high-grade dysplasia, and 68% (n = 28) revealed invasion. All gastric-type IPNs (n = 9) and most ITPNs/IOPNs showed consistent colabeling for CK7/MUC6, which was less common among others (P = .004). Intestinal-type IPNs (n = 5) showed higher rates of CK20 expression than others (P < .001). Overall, the most commonly mutated genes included TP53 and APC, while copy number variants affected ELF3 and CDKN2A/B. All gastric-type IPNs contained an alteration affecting the Wnt signaling pathway; 7 of 9 (78%) showed aberrations in the MAPK pathway. Mutations in APC and KRAS were common in gastric-type IPNs as compared with others (P = .01 for both). SMAD4 was more frequently mutated in intestinal-type IPNs (P = .02). Pancreatobiliary-type IPNs (n = 14) exhibited frequent alterations in tumor suppressor genes including TP53, CDKN2A/B, and ARID2 (P = .04, P = .01 and P = .002, respectively). Of 6 IOPNs analyzed, 3 (50%) revealed ATP1B1-PRKACB fusion. ITPNs (n = 6) showed relatively few recurrent genetic aberrations. Follow-up information was available for 38 patients (median, 58.5 months). The ratio of disease-related deaths was higher for the cases with invasion (56% versus 10%).

CONCLUSIONS.—

Tumoral intraductal neoplasms of the bile ducts, similar to their counterparts in the pancreas, are morphologically and genetically heterogeneous.

Krüppel-like factor 10 modulates stem cell phenotypes of pancreatic adenocarcinoma by transcriptionally regulating notch receptors

BACKGROUND

Pancreatic adenocarcinoma (PDAC) is well known for its rapid distant metastasis and local destructive behavior. Loss of Krüppel-like factor 10 (KLF10) contributes to distant migration of PDAC. The role of KLF10 in modulating tumorigenesis and stem cell phenotypes of PDAC is unclear.

METHODS

Additional depletion of KLF10 in KC (LSL: Kras^G12D; Pdx1-Cre) mice, a spontaneous murine PDAC model, was established to evaluate tumorigenesis. Tumor specimens of PDAC patients were immune-stained of KLF10 to correlate with local recurrence after curative resection. Conditional overexpressing KLF10 in MiaPaCa and stably depleting KLF10 in Panc-1 (Panc-1-pLKO-shKLF10) cells were established for evaluating sphere formation, stem cell markers expression and tumor growth. The signal pathways modulated by KLF10 for PDAC stem cell phenotypes were disclosed by microarray analysis and validated by western blot, qRT-PCR, luciferase reporter assay. Candidate targets to reverse PDAC tumor growth were demonstrated in murine model.

RESULTS

KLF10, deficient in two-thirds of 105 patients with resected pancreatic PDAC, was associated with rapid local recurrence and large tumor size. Additional KLF10 depletion in KC mice accelerated progression from pancreatic intraepithelial neoplasia to PDAC. Increased sphere formation, expression of stem cell markers, and tumor growth were observed in Panc-1-pLKO-shKLF10 compared with vector control. Genetically or pharmacologically overexpression of KLF10 reversed the stem cell phenotypes induced by KLF10 depletion. Ingenuity pathway analysis and gene set enrichment analysis showed that Notch signaling molecules, including Notch receptors 3 and 4, were over-expressed in Panc-1-pLKO-shKLF10. KLF10 transcriptionally suppressed Notch-3 and -4 by competing with E74-like ETS transcription factor 3, a positive regulator, for promoter binding. Downregulation of Notch signaling, either genetically or pharmacologically, ameliorated the stem cell phenotypes of Panc-1-pLKO-shKLF10. The combination of metformin, which upregulated KLF10 expression via phosphorylating AMPK, and evodiamine, a non-toxic Notch-3 methylation stimulator, delayed tumor growth of PDAC with KLF10 deficiency in mice without prominent toxicity.

CONCLUSIONS

These results demonstrated a novel signaling pathway by which KLF10 modulates stem cell phenotypes in PDAC through transcriptionally regulating Notch signaling pathway. The elevation of KLF10 and suppression of Notch signaling may jointly reduce PDAC tumorigenesis and malignant progression.

Synergistic Antitumoral Effect of Epigenetic Inhibitors and Gemcitabine in Pancreatic Cancer Cells

Epigenetic modifications could drive some of the molecular events implicated in proliferation, drug resistance and metastasis of pancreatic ductal adenocarcinoma (PDAC). Thus, epigenetic enzyme inhibitors could be the key to revert those events and transform PDAC into a drug-sensitive tumor. We performed a systematic study with five different epigenetic enzyme inhibitors (1, UVI5008, MS275, psammaplin A, and BIX01294) targeting either Histone Deacetylase (HDAC) 1 or 1/4, DNA methyltransferase 3a (DNMT3a), Euchromatic histone lysine methyltransferase 2 (EHMT2), or Sirtuin 1 (SIRT1), as well as one drug that restores the p53 function (P53R3), in three different human PDAC cell lines (SKPC-1, MIA PaCa-2, and BxPC-3) using 2D and 3D cell cultures. The synergistic effect of these antitumoral drugs with gemcitabine was tested and the most efficient combinations were characterized by RNA-seq. The inhibition of HDAC1/4 (MS275), HDAC1/4/SIRT1/DNMT3a (UVI5008) or EHMT2 (BIX01294) induced a significant reduction on the cell viability, even in gemcitabine-resistance cells. The combination of UVI5008 or MS275 with gemcitabine induced a synergistic effect at low concentration and the RNA-Seq analysis revealed some synergy candidate genes as potential biomarkers. Reverting aberrant epigenetic modifications in combination with gemcitabine offers an alternative treatment for PDAC patients, with an important reduction of the therapeutic dose.

E74-Like Factor 3 Promotes Endometrial Cancer Cell Proliferation, Migration and Invasion via Regulating Mucin 1/Hypoxia-Inducible Factor 1α Pathway

High expression of E74-like factor 3 (ELF3) has been reported in type 1 endometrial cancer (EC). Bioinformatics analysis predicted a positive correlation with ELF3 and mucin 1 (MUC1)/hypoxiainducible factor 1α (HIF-1α), a previously identified cancer-promoting pathway. This study focused on the MUC1/HIF-1α-involved action mechanism of ELF3 in EC. ELF3 expression in EC cell lines was measured by RT-qPCR and western blot analysis. Following the expression of ELF3 was silent, cell proliferation was examined using CCK-8 and colony formation assay, cell migration and invasion were observed using wound healing and transwell assays. The effect of ELF1 silencing on MUC1/HIF-1α expression was detected by western blot. Rescue experiments incorporating pcDNA3.1(+)/MUC1 explored the interaction between ELF3 and MUC1/HIF-1α in EC cell proliferation, migration and invasion. ELF3 was found to be expressed at a high level in EC cell lines, and the silencing of it effectively inhibited EC cell proliferation. Moreover, ELF silencing also inhibited the migration and invasion of EC cells. Consistent with the database prediction, a positive correlation between ELF3 and MUC1/HIF-1α was observed. More importantly, MUC1 overexpression abated the promotive effect of ELF3 silencing on EC cell proliferation, migration and invasion. ELF3 promotes EC cell proliferation, migration and invasion by regulating MUC1/HIF-1α pathway. Thus, ELF3 as well as MUC1/HIF-1α pathway may be particle targets in the treatment of EC.

The Role and Mechanism of microRNA-1224 in Human Cancer

microRNAs (miRNAs) are a type of small endogenous non-coding RNAs composed of 20-22 nucleotides, which can regulate the expression of a gene by targeting 3’ untranslated region (3’-UTR) of mRNA. Many studies have reported that miRNAs are involved in the occurrence and progression of human diseases, including malignant tumors. miR-1224 plays significant roles in different tumors, including tumor proliferation, metastasis, invasion, angiogenesis, biological metabolism, and drug resistance. Mostly, it serves as a tumor suppressor. With accumulating proofs of miR-1224, it can act as a potential bio-indicator in the diagnosis and prognosis of patients with cancer. In this article, we review the characteristics and research progress of miR-1224 and emphasize the regulation and function of miR-1224 in different cancer. Furthermore, we conclude the clinical implications of miR-1224. This review may provide new horizons for deeply understanding the role of miR-1224 as biomarkers and therapeutic targets in human cancer.

ELF3-induced miR-182 inhibits adipogenic differentiation in Graves' orbitopathy by targeting thyrotropin receptor

Introduction

Graves' orbitopathy (GO) is a common autoimmune disease, but its specific pathogenesis has not been fully elucidated. MicroRNAs (miRNAs) possess an important regulatory function in the occurrence and development of autoimmune diseases. In the present study, we explored the potential role of miR-182 in the diagnosis of GO.

Material and methods

The expression of miR-182, thyrotropin receptor (TSHR) and adipocytokines was ascertained by qRT-PCR assay. The triglyceride (TG) content was ascertained by ELISA assay. The lipid droplet content was identified by Oil Red O staining. The relationship between E74-like factor 3 (ELF3), miR-182 and TSHR was confirmed by ChIP, dual-luciferase reporter assay and RIP.

Results

The expression of miR-182 decreased, while TSHR increased, and adipocytokine (adiponectin, leptin, PPAR-γ, and AP2) levels were upregulated in preorbital adipose tissue of patients with GO and differential medium induced (DM-induced) 3T3-L1 cells. MiR-182 mimics inhibited adipocytokine expression, TG content and lipid droplets; however, miR-182 inhibitor had the opposite results. TSHR was a target gene of miR-182, and TSHR overexpression (oe-TSHR) reversed the effect of miR-182 mimics on adipogenic differentiation of 3T3-L1 by DM treatment. ELF3 transcription promoted miR-182 expression. Oe-ELF3 inhibited adipocytokine expression and reduced TG content and lipid droplets in DM-induced 3T3-L1 cells. MiR-182 inhibitor reversed the effect of oe-ELF3 on adipogenic differentiation in 3T3-L1.

Conclusions

ELF3/miR-182/TSHR axis alleviated Graves' orbitopathy by inhibiting adipogenic differentiation.

Anticancer activity of ursolic acid on retinoblastoma cells determined by bioinformatics analysis and validation

Background

This article aims to explore whether ursolic acid (UA) inhibits the progression of retinoblastoma (Rb) by regulating stearoyl-CoA desaturase (SCD).

Methods

The Gene Expression Omnibus (GEO) database was used to filter the chip, then the GEO2R software was used to analyze the microarray data (GSE97508, GSE24673, and GSE110811). Gene set enrichment analysis (GSEA) was used to analyze the relationship between the expression level of SCD and the proliferation, migration, invasion, and inflammation in Rb patients. SO-RB50 and Y79 cell proliferation, migration, and invasion were assessed by the CCK-8 assay, the colony formation assay, the Transwell assay, and the wound scratch test. The protein expression levels of SCD were measured by western blot. The mRNA expression levels of IL-8, IL-6, CXCL1, and CCL2 were measured by RT-qPCR. The protein expression levels of IL-8 and IL-6 were measured by ELISA. A xenograft nude mouse model was established to evaluate the effect of UA on tumor growth in male BALB/c mice.

Results

The expression levels of SCD were related to cell proliferation, migration, invasion, and inflammation. UA inhibited SO-RB50 and Y79 cell proliferation, migration, and invasion. At the same time, UA suppressed tumor growth in the xenograft nude mouse model. Overexpression of SCD promoted SO-RB50 and Y79 cell proliferation, migration, invasion, and inflammation, while SCD knockout inhibited SO-RB50 and Y79 cell proliferation, migration, invasion, and inflammation. Importantly, UA inhibited the proliferation, migration, and invasion of Rb cells through SCD inhibition.

Conclusions

UA inhibited the proliferation, migration, and invasion of Rb cells through SCD. This provides a new scientific basis for targeted therapy of Rb.

miR-34c-5p mediates the cellular malignant behaviors of oral squamous cell carcinoma through targeted binding of TRIM29

Background

This investigation examined the effects of the microRNA miR-34c-5p on the proliferation, migration, and invasion of oral squamous cell carcinoma (OSCC) and the mechanisms involved.

Methods

The Gene Expression Omnibus (GEO) database was used to filter the chips, and the GEO2R software (https://www.ncbi.nlm.nih.gov/geo/geo2r/) was used to analyze the microarray data (GSE28100 and GSE45238). Gene set enrichment analysis (GSEA) was used to study the relationship between the expression of miR-34c-5p and the distant metastasis and pathological grade of OSCC. The correlation between TRIM29 (tripartite motif containing 29) expression and the malignant clinical phenotype of OSCC was also examined. The mRNA and protein expression levels of miR-34c-5p and TRIM29 were measured by real time quantitative reverse transcription polymerase chain reaction (RT-qPCR) and Western blot analysis. The proliferation, migration, invasion and apoptosis of the human oral squamous carcinoma cell lines CAL-27 and Tca8113 was assessed by performing cell-counting kit-8 (CCK-8) assays, colony formation assays, transwell tests, wound scratch tests and flow cytometry. Luciferase reporter assays were used to predict the relationship between miR-34c-5p and TRIM29. A xenograft nude model was established and used to evaluate the effect of miR-34c-5p on tumor growth in female BALB/c mice.

Results

The expression of miR-34c-5p was significantly correlated with the proliferation, migration, and metastasis of OSCC. Overexpression of miR-34c-5p promoted the proliferation, migration, and invasion of CAL-27 and Tca8113 cells, and suppressed their apoptosis. Inversely, low expression of miR-34c-5p suppressed the proliferation, migration, and invasion of CAL-27 and Tca8113 cells, and promoted their apoptosis. Overexpression of miR-34c-5p promoted tumor growth in the xenograft nude mice model. The expression of TRIM29 was related to malignant clinical phenotype of OSCC. Overexpression of TRIM29 inhibited the proliferation, migration and invasion of CAL-27 and Tca8113 cell, and induced their apoptosis. TRIM29 knockout had just the opposite effect. Importantly, miR-34c-5p binds to TRIM29 and inhibited TRIM29 expression.

Conclusions

MiR-34c-5p regulates the proliferation, migration, invasion, and apoptosis of OSCC through targeted binding of TRIM29. This may represent a novel therapeutic target for the treatment of patients with OSCC.

Exosomal-mediated transfer of APCDD1L-AS1 induces 5-fluorouracil resistance in oral squamous cell carcinoma via miR-1224-5p/nuclear receptor binding SET domain protein 2 (NSD2) axis

Oral squamous cell carcinoma (OSCC) poses a threat to public health worldwide. LncRNA APCDD1L-AS1 has been reported to participate in tumorigenesis and development of acquired chemoresistance. However, the role of APCDD1L-AS1 in 5-fluorouracil (5-FU) resistance regulation within OSCC is still obscure. In this study, 5-FU-resistant cell models were established with OSCC cell lines (HSC-3 and HN-4). Gene expressions and protein levels were detected by RT-qPCR and Western blotting, respectively. CCK-8, colony forming, and flow cytometry were utilized to measure IC50 value, cell viability, and cell apoptosis of 5-FU-resistant OSCC cells. Dual-luciferase reporter assay and RIP assay were applied to identify the associations between miR-1224-5p and APCDD1L-AS1 or NSD2. Herein, high APCDD1L-AS1 expression was shown in OSCC tissues and cells resistant to 5-FU and related to the worse prognosis of OSCC patients. APCDD1L-AS1 knockdown impaired 5-FU resistance in 5-FU-resistant OSCC cells by reducing IC₅₀ value, suppressing cell viability, and accelerating cell apoptosis. Besides, extracellular APCDD1L-AS1 could be transferred to sensitive cells via exosome incorporation, thereby transmitting 5-FU resistance in OSCC cells. Besides, miR-1224-5p was a molecular target of APCDD1L-AS1 and directly targeted NSD2 in 5-FU-resistant cells. MiR-1224-5p exhibited a much lower level in 5-FU-resistant tissues and increased 5-FU sensitivity in 5-FU-resistant OSCC cells. Moreover, NSD2 upregulation neutralized the influence of blocking APCDD1L-AS1 in HSC-3/5-FU and HN-4/5-FU cells on 5-FU resistance. To sum up, our study demonstrated that exosomal APCDD1L-AS1 conferred resistance to 5-FU in HSC-3/5-FU and HN-4/5-FU cells via the miR-1224-5p/NSD2 axis, thus providing a novel target for OSCC chemoresistance.

Splice and Dice: Intronic microRNAs, Splicing and Cancer

Introns span only a quarter of the human genome, yet they host around 60% of all known microRNAs. Emerging evidence indicates the adaptive advantage of microRNAs residing within introns is attributed to their complex co-regulation with transcription and alternative splicing of their host genes. Intronic microRNAs are often co-expressed with their host genes, thereby providing functional synergism or antagonism that is exploited or decoupled in cancer. Additionally, intronic microRNA biogenesis and the alternative splicing of host transcript are co-regulated and intertwined. The importance of intronic microRNAs is under-recognized in relation to the pathogenesis of cancer.

The Immune-Related Gene ELF3 is a Novel Biomarker for the Prognosis of Ovarian Cancer

Background

Ovarian cancer (OC) is a fatal gynaecological malignancy. The study aimed to conduct a comprehensive study to determine the role of ELF3 in OC through bioinformatic analysis.

Methods

Kruskal-Wallis test, Wilcoxon sign-rank test, and logistic regression were used to evaluate the relationship between clinical characteristics and ELF3 expression. Kaplan-Meier method and Cox regression analysis were used to evaluate the prognostic factors. Gene set enrichment analysis (GSEA) and immuno-infiltration analysis were used to evaluate the significant involvement of ELF3 in function.

Results

High ELF3 expression in OC was associated with age (P< 0.001). High ELF3 expression predicted a poorer overall survival (OS) (HR: 1.37; 95% CI: 1.05-1.78; P=0.019) and disease specific survival (DSS) (HR: 1.43; 95% CI: 1.08-1.89; P=0.013). And ELF3 expression (HR: 1.779; 95% CI: 1.281-2.472; P<0.001) was independently correlated with OS in OC patients. GSEA demonstrated that pathways including GPCR-ligand binding, neuronal system, signaling by WNT, translation, neuroactive ligand-receptor interaction, and TCF dependent signaling in response to WNT were differentially enriched in ELF3 low expression phenotype. Immune infiltration analysis showed that ELF3 expression was correlated with immune infiltrates.

Conclusion

ELF3 expression in OC patients was significantly associated with poor survival and immune infiltration and a promising prognostic biomarker in OC.

Upregulation of KLK8 Predicts Poor Prognosis in Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is a growing cause of cancer-related mortality worldwide. Kallikrein-related peptidase 8 (KLK8) has potential clinical values in many cancers. However, the clinicopathological significances of KLK8 in PDAC remain unknown. We explored the relationship of KLK8 to clinicopathological features of PDAC based on public databases. KLK8 expression was examined in human PDAC tissues. Cell proliferation and apoptosis were evaluated in KLK8-overexpressed human pancreatic cancer cell lines Mia-paca-2 and Panc-1. The related signaling pathways of KLK8 involved in pancreatic cancer progression were analyzed by gene set enrichment analysis (GSEA) and further verified in in vitro studies. We found that KLK8 was up-regulated in tumor tissues in the TCGA-PAAD cohort, and was an independent prognostic factor for both overall survival and disease-free survival of PDAC. KLK8 mRNA and protein expressions were increased in PDAC tissues compared with para-cancerous pancreas. KLK8 overexpression exerted pro-proliferation and anti-apoptotic functions in Mia-paca-2 and Panc-1 cells. GSEA analysis showed that KLK8 was positively associated with PI3K-Akt-mTOR and Notch pathways. KLK8-induced pro-proliferation and anti-apoptotic effects in Mia-paca-2 and Panc-1 cells were attenuated by inhibitors for PI3K, Akt, and mTOR, but not by inhibitor for Notch. Furthermore, overexpression of KLK8 in Mia-paca-2 and Panc-1 cells significantly increased epidermal growth factor (EGF) levels in the culture media. EGF receptor (EGFR) inhibitor could block KLK8-induced activation of PI3K/Akt/mTOR pathway and attenuate pro-proliferation and anti-apoptotic of KLK8 in Mia-paca-2 and Panc-1 cells. In conclusion, KLK8 overexpression exerts pro-proliferation and anti-apoptotic functions in pancreatic cancer cells via EGF signaling-dependent activation of PI3K/Akt/mTOR pathway. Upregulated KLK8 in PDAC predicts poor prognosis and may be a potential therapeutic target for PDAC.

MiR-3663-3p participates in the anti-hepatocellular carcinoma proliferation activity of baicalein by targeting SH3GL1 and negatively regulating EGFR/ERK/NF-κB signaling

Baicalein is a purified flavonoid that exhibits anticancer effects in hepatocellular carcinoma (HCC). However, its underlying molecular mechanisms remain largely unclear. In this study, we found that baicalein inhibited HCC cell growth, induced apoptosis, and blocked cell cycle arrest at the S phase in vitro, as well as reduced HCC tumor volume and weight in vivo. Quantitative reverse transcriptase-PCR (qRT-PCR) results suggested that miR-3663-3p was downregulated in HCC tissues. After baicalein treatment, miR-3663-3p expression was upregulated in HCC cells. Transfection of miR-3663-3p suppressed HCC cell proliferation and colony formation, increased the proportion of apoptotic cells in vitro, and reduced the volume and weight of tumors in vivo. The results of dual-luciferase reporter assay showed that miR-3663-3p could directly bind to the 3'-UTR of SH3GL1. SH3GL1 overexpression partly reduced the growth-inhibiting effect of miR-3663-3p. Both baicalein treatment and miR-3663-3p overexpression downregulated the expression of SH3GL1 and inactivated the Erk1/2, p-NF-κB/p65, and EGFR signaling pathways. Overall, our data suggest that baicalein may act as a novel HCC suppressor, and that the miR-3663-3p/SH3GL1/EGFR/ERK/NF-κB pathway plays a vital role in HCC progression. Thus, baicalein treatment or miR-3663-3p induction may be a promising strategy for HCC therapy.

Crosstalk between miRNAs and signaling pathways involved in pancreatic cancer and pancreatic ductal adenocarcinoma

Pancreatic cancer (PC) is the seventh leading cause of cancer-related deaths worldwide with 5-year survival rates below 8%. Most patients with PC and pancreatic ductal adenocarcinoma (PDAC) die after relapse and cancer progression as well as resistance to treatment. Pancreatic tumors contain a high desmoplastic stroma that forms a rigid mass and has a potential role in tumor growth and metastasis. PC initiates from intraepithelial neoplasia lesions leading to invasive cancer through various pathways. These lesions harbor particular changes in signaling pathways involved in the tumorigenesis process. These events affect both the epithelial cells, including the tumor and the surrounding stroma, and eventually lead to the formation of complex signaling networks. Genetic studies of PC have revealed common molecular features such as the presence of mutations in KRAS gene in more than 90% of patients, as well as the inactivation or deletion mutations of some tumor suppressor genes including TP53, CDKN2A, and SMAD4. In recent years, studies have also identified different roles of microRNAs in PC pathogenesis as well as their importance in PC diagnosis and treatment, and their involvement in various signaling pathways. In this study, we discussed the most common pathways involved in PC and PDAC as well as their role in tumorigenesis and progression. Furthermore, the miRNAs participating in the regulation of these signaling pathways in PC progression are summarized in this study. Therefore, understanding more about pathways involved in PC can help with the development of new and effective therapies in the future.

Context Matters: NOTCH Signatures and Pathway in Cancer Progression and Metastasis

The Notch signaling pathway is a critical player in embryogenesis but also plays various roles in tumorigenesis, with both tumor suppressor and oncogenic activities. Mutations, deletions, amplifications, or over-expression of Notch receptors, ligands, and a growing list of downstream Notch-activated genes have by now been described for most human cancer types. Yet, it often remains unclear what may be the functional impact of these changes for tumor biology, initiation, and progression, for cancer therapy, and for personalized medicine. Emerging data indicate that Notch signaling can also contribute to increased aggressive properties such as invasion, tumor heterogeneity, angiogenesis, or tumor cell dormancy within solid cancer tissues; especially in epithelial cancers, which are in the center of this review. Notch further supports the “stemness” of cancer cells and helps define the stem cell niche for their long-term survival, by integrating the interaction between cancer cells and the cells of the tumor microenvironment (TME). The complexity of Notch crosstalk with other signaling pathways and its roles in cell fate and trans-differentiation processes such as epithelial-to-mesenchymal transition (EMT) point to this pathway as a decisive player that may tip the balance between tumor suppression and promotion, differentiation and invasion. Here we not only review the literature, but also explore genomic databases with a specific focus on Notch signatures, and how they relate to different stages in tumor development. Altered Notch signaling hereby plays a key role for tumor cell survival and coping with a broad spectrum of vital issues, contributing to failed therapies, poor patient outcome, and loss of lives.

MiR-1224-5p Activates Autophagy, Cell Invasion and Inhibits Epithelial-to-Mesenchymal Transition in Osteosarcoma Cells by Directly Targeting PLK1 Through PI3K/AKT/mTOR Signaling Pathway

Background

Osteosarcoma (OS) is one of the most common malignant bone tumors with a poor overall prognosis. MiR-1224-5p plays an important role in cancer, but its function and mechanism in OS have not been studied.

Materials and Methods

The expression of miR-1224-5p and PLK1 was detected by qRT-PCR in OS cells, adjacent tissues, and cell lines. Dual-luciferase reporter gene assay was used to verify the interaction between miR-1224-5p and PLK1. The expression of miR-1224-5p and PLK1 was intervened by transfection with miR-1224-5p mimic, NC mimic, pc-NC and PLK1, respectively. MTT, colony formation assay, Transwell and flow cytometry were used to observe the cell proliferation, invasion and apoptosis. Western blot was used to detect the expression levels of PLK1, PI3K/AKT/mTOR signaling pathway-related proteins, autophagy-related proteins, and epithelial-mesenchymal transition (EMT)-related proteins in the cells.

Results

We found that miR-1224-5p was down-regulated and PLK1 expression was up-regulated in OS tissues and cells. On the other hand, it is further confirmed that PLK1 was a target gene of miR-1224-5p. Overexpression of miR-1224-5p inhibited the proliferation, invasion while promoted the apoptosis of OS cells, whereas overexpression of PLK1 promoted the proliferation, invasion and inhibited the apoptosis of OS cells. In the miR-1224-5p group (overexpression of miR-1224-5p), PI3K, AKT, and mTOR protein phosphorylation levels were significantly reduced, while autophagic activity was significantly activated, and the degree of EMT was significantly reduced. But the results in the PLK1 group (overexpression of PLK1) were the opposite. In addition, overexpression of miR-1224-5p reversed the effect of PLK1 upregulation on OS cells.

Conclusion

MiR-1224-5p targets PLK1 to inhibit PI3K/AKT/mTOR signaling pathway, thus mediating the proliferation, invasion, apoptosis, autophagy and EMT in OS cells.

MicroRNA-23b-3p promotes pancreatic cancer cell tumorigenesis and metastasis via the JAK/PI3K and Akt/NF-κB signaling pathways

MicroRNA (miR)-23b-3p plays an important role in tumor growth, proliferation, invasion and migration in pancreatic cancer (PC). However, the function and mechanistic role of miR-23b-3p in the development of PC remains largely unknown. In the present study, the miR-23b-3p levels in the serum of patients with PC were found to be elevated, and the phosphorylation levels of Janus kinase (JAK)2, PI3K, Akt and NF-κВ were found to be upregulated. In addition, miR-23b-3p was induced in response to interleukin-6 (IL-6), which is known to be involved in the progression of PC. Overexpression of miR-23b-3p, on the other hand, activated the JAK/PI3K and Akt/NF-κB signaling pathways in PC cells, as evidenced by miR-23b-3p-induced upregulation of phosphorylated (p-)JAK2, p-PI3K, p-Akt and p-NF-κВ, as well as the downregulation of PTEN; and these effects were found to be reversible by miR-23b-3p inhibition. Furthermore, miR-23b-3p was found to downregulate PTEN by directly targeting the 3′-untranslated region of PTEN mRNA. Notably, in an in vivo xenograft mouse model, overexpression of miR-23b-3p accelerated PC cell-derived tumor growth, activated the JAK/Akt/NF-κВ signaling pathway and promoted liver metastasis. In contrast, knockdown of miR-23b-3p suppressed tumor growth and metastasis as well as JAK/Akt/NF-κВ signaling activity. In vivo imaging of the mice further confirmed the metastasis promoting role of miR-23b-3p in PC. These results suggested that miR-23b-3p enhances PC cell tumorigenesis and metastasis, at least, partially via the JAK/PI3K and Akt/NF-κB signaling pathways. Therefore, targeting miR-23b-3p or the JAK/PI3K and Akt/NF-κB signalings may be potential therapeutic strategy against PC.

MicroRNA‑214 promotes the EMT process in melanoma by downregulating CADM1 expression

Melanoma is a malignant skin cancer type associated with a high mortality rate, but its treatment is currently not ideal. Both microRNA (miR)-214 and cell adhesion molecule 1 (CADM1) are differentially expressed in melanoma, but their role in this cancer type remains unknown. Therefore, the aim of the present study was to investigate the role of CADM1 and miR-214 in melanoma to identify novel targets for its treatment. The expression levels of CADM1 and miR-214 in cells were detected by reverse transcription-quantitative PCR (RT-qPCR). Moreover, cell viability, migration and invasion were measured by MTT, wound healing and Transwell assays, respectively. In addition, the relative expression levels of epithelial-mesenchymal transition (EMT)-related proteins in cells were detected by RT-qPCR and western blotting. It was found that the expression of CADM1 was inhibited in melanoma cells, while miR-214 expression was increased during melanoma tumorigenesis. Furthermore, miR-214 mimics promoted the viability, migration and invasion of melanoma cells. It was also demonstrated that the downregulation of CADM1 reversed the inhibitory effect of the miR-214 inhibitor in melanoma. Moreover, overexpression of CADM1 inhibited the EMT process in melanoma, while the miR-214 inhibitor suppressed the EMT process. The results also indicated that miR-214 promoted the EMT process by downregulating CADM1, which may represent a novel mechanism for the progression of melanoma.