Inhibition of EGR1 inhibits glioma proliferation by targeting CCND1 promoter

Comprehensive machine learning-based integration develops a novel prognostic model for glioblastoma

In this study, we developed a new prognostic model for glioblastoma (GBM) based on an integrated machine learning algorithm. We used univariate Cox regression analysis to identify prognostic genes by combining six GBM cohorts. Based on the prognostic genes, 10 machine learning algorithms were integrated into 117 algorithm combinations, and the artificial intelligence prognostic signature (AIPS) with the greatest average C-index was chosen. The AIPS was compared with 10 previously published models by univariate Cox analysis and the C-index. We compared the differences in prognosis, tumor immune microenvironment (TIME), and immunotherapy sensitivity between the high and low AIPS score groups. The AIPS based on the random survival forest algorithm with the highest average C-index (0.868) was selected. Compared with the previous 10 prognostic models, our AIPS has the highest C-index. The AIPS was closely linked to the clinical features of GBM. We discovered that patients in the low score group had improved prognoses, a more active TIME, and were more sensitive to immunotherapy. Finally, we verified the expression of several key genes by western blotting and immunohistochemistry. We identified an ideal prognostic signature for GBM, which might provide new insights into stratified treatment approaches for GBM patients.

Oxidative stress-induced EGR1 upregulation promotes NR4A3-mediated nucleus pulposus cells apoptosis in intervertebral disc degeneration

This study aimed to reveal the specific role of early growth response protein 1 (EGR1) and nuclear receptor 4A3 (NR4A3) in nucleus pulposus cells (NPCs) and the related molecular mechanism and to identify a new strategy for treating intervertebral disc degeneration (IVDD). Bioinformatics analysis was used to explore and predict IVDD-related differentially expressed genes, and chromatin immunoprecipitation sequencing (ChIP-seq) revealed NR4A3 as the EGR1 target gene. An in vitro NPC model induced by tributyl hydrogen peroxide (TBHP) and a rat model induced by fibrous ring acupuncture were established. Western blotting, quantitative real-time polymerase chain reaction (qRT-PCR), immunohistochemical staining, immunofluorescence staining, and flow cytometry were used to detect the effects of EGR1 and NR4A3 knockdown and overexpression on NPC apoptosis and the expression of extracellular matrix (ECM) anabolism-related proteins. Interactions between EGR1 and NR4A3 were analyzed via ChIP-qPCR and dual luciferase assays. EGR1 and NR4A3 expression levels were significantly higher in severely degenerated discs (SDD) than in mildly degenerated discs (MDD), indicating that these genes are important risk factors in IVDD progression. ChIP-seq and RNA-seq revealed NR4A3 as a direct downstream target of EGR1, and this finding was verified by ChIP-qPCR and dual luciferase reporter experiments. Remarkably, the rescue experiments showed that EGR1 promotes TBHP-induced NPC apoptosis and impairs ECM anabolism, dependent on elevated NR4A3 expression. In summary, the EGR1-NR4A3 axis mediates the progression of NPC apoptosis and ECM impairment and is a potential therapeutic target in IVDD.

miR-329b-5p Affects Sheep Intestinal Epithelial Cells against Escherichia coli F17 Infection

Diarrhea is the most common issue in sheep farms, typically due to pathogenic Escherichia coli (E. coli) infections, such as E. coli F17. microRNA, a primary type of non-coding RNA, has been shown to be involved in diarrhea caused by pathogenic E. coli. To elucidate the profound mechanisms of miRNA in E. coli F17 infections, methods such as E. coli F17 adhesion assay, colony counting assay, relative quantification of bacterial E. coli fimbriae gene expression, indirect immune fluorescence (IF), Cell Counting Kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU), Western blotting (WB), and scratch assay were conducted to investigate the effect of miR-329b-5p overexpression/knock-down on E. coli F17 susceptibility of sheep intestinal epithelial cells (IECs). The findings indicated that miR-329b-5p enhances the E. coli F17 resistance of sheep IECs to E.coli F17 by promoting adhesion between E. coli F17 and IEC, as well as IEC proliferation and migration. In summary, miR-329b-5p plays a crucial role in the defense of sheep IECs against E. coli F17 infection, providing valuable insights into its mechanism of action.

α-Hederin promotes ferroptosis and reverses cisplatin chemoresistance in non-small cell lung cancer

BACKGROUND

Cisplatin is a core chemotherapy regimen in non-small cell lung cancer (NSCLC). However, chemoresistance to cisplatin leads to a poor prognosis in NSCLC. α-Hederin is a natural compound extracted from Nigella sativa. The study aims to explore the effects of α-Hederin on cisplatin resistance in NSCLC.

METHODS

NSCLC cisplatin-resistant cell lines A549/DPP and PC-9 were cultured to evaluate the efficacy of α-Hederin in the treatment of NSCLC in vitro and in vivo. Metabolomics and RNA-seq analysis were used to determine the potential mechanisms of action of α-Hederin.

RESULTS

The results showed that α-Hederin inhibited cisplatin-resistant NSCLC cells proliferation and metastasis. Mice xenograft, orthotopic, and metastatic A549/DPP cell models also showed the anti-tumor effects of α-Hederin. The metabolomics and RNA-seq analysis results showed that α-Hederin activated DDIT3/ATF3 pathway and ferroptosis via silencing SLC7A11 and GPX4. Furthermore, α-Hederin enhanced the nuclear expression of EGR1. Bioinformatics and luciferase experiments confirmed that EGR1 binds to the miR-96-5p promoter region, inhibiting transcription. In addition, miR-96-5p directly suppressed the levels of DDIT3.

CONCLUSION

This study revealed that α-Hederin activated EGR1 nuclear translocation and directly repressed miR-96-5p. It also promoted DDIT3/ATF3-mediated ferroptosis and reversed cisplatin resistance in NSCLC.

Early growth response 1 promoted the invasion of glioblastoma multiforme by elevating HMGB1

BACKGROUND

Glioblastoma multiforme (GBM) is the most common and deadly glioma subtype. Early growth response 1 (EGR1) participates in the progression of several cancer types, but the expression and function of EGR1 in GBM was rarely investigated.

METHODS

The expressions of EGR1 in GBM were detected with qRT-PCR and immunohistochemistry in 12 pairs of fresh GBM tissues and 116 paraffin-embedded specimens. The patients were divided into high and low EGR1 groups according to the IHC score of EGR1, and the prognostic significances of different groups were evaluated with univariate and multivariate analyses. With in-vitro experiments, we assessed the role of EGR1 in the proliferation and invasion of GBM cells.

RESULTS

In our study, EGR1 was up-regulated in GBM tissues compared with tumor-adjacent normal tissues. High expression of EGR1 or HMGB1 were unfavorable prognostic biomarkers of GBM. Coexpression of EGR1 and HMGB1 could predict the prognosis of GBM more sensitively. EGR1 facilitated the proliferation and invasion of GBM cells. Moreover, EGR1 promoted the invasion, instead of proliferation, of GBM cells by elevating the expression of HMGB1.

CONCLUSIONS

ERG1 was a prognostic biomarker of GBM, and ERG1 and HMGB1 synergistically could predict the GBM prognosis more precisely. ERG1 could promote GBM cell invasion by inducing HMGB1 expression.

Curcumin reduces paclitaxel resistance in ovarian carcinoma cells by upregulating SNIP1 and inhibiting NFκB activity

The therapeutic activity of paclitaxel against ovarian carcinoma is relatively low due to the frequent occurrence of chemoresistance and disease recurrence. We found earlier that a combination of curcumin and paclitaxel reduces cell viability and promotes apoptosis in paclitaxel-resistant (i.e., taxol-resistant, Txr) ovarian cancer cells. In the present study, we first used RNA sequencing (RNAseq) analysis to identify genes that are upregulated in Txr cell lines but downregulated by curcumin in ovarian cancer cells. The nuclear factor kappa B (NFκB) signaling pathway was shown to be upregulated in Txr cells. Furthermore, based on the protein interaction database BioGRID, we found that Smad nuclear interacting protein 1 (SNIP1) may be involved in regulating the activity of NFκB in Txr cells. Accordingly, curcumin upregulated SNIP1 expression, which in turn downregulated the pro-survival genes Bcl-2 and Mcl-1. Using shRNA-guided gene silencing, we found that SNIP1 depletion reversed the inhibitory effect of curcumin on NFκB activity. Moreover, we identified that SNIP1 enhanced NFκB protein degradation, thereby suppressing NFκB/p65 acetylation, which is involved in the inhibitory effect of curcumin on NFκB signaling. The transcription factor early growth response protein 1 (EGR1) was shown to represent an upstream transactivator of SNIP1. Consequently, we show that curcumin inhibits NFκB activity by modulating the EGR1/SNIP1 axis to attenuate p65 acetylation and protein stability in Txr cells. These findings provide a new mechanism to account for the effects of curcumin in inducing apoptosis and reducing paclitaxel resistance in ovarian cancer cells.

Molecular mechanisms of microRNAs in glioblastoma pathogenesis

Glioblastoma (GBM) is human's most prevalent and severe brain cancer. Epigenetic regulators, micro(mi)RNAs, significantly impact cellular health and disease because of their wide range of targets and functions. The "epigenetic symphony" in which miRNAs perform is responsible for orchestrating the transcription of genetic information. The discovery of regulatory miRNA activities in GBM biology has shown that various miRNAs play a vital role in disease onset and development. Here, we summarize our current understanding of the current state-of-the-art and latest findings regarding the interactions between miRNAs and molecular mechanisms commonly associated with GBM pathogenesis. Moreover, by literature review and reconstruction of the GBM gene regulatory network, we uncovered the connection between miRNAs and critical signaling pathways such as cell proliferation, invasion, and cell death, which provides promising hints for identifying potential therapeutic targets for the treatment of GBM. In addition, the role of miRNAs in GBM patient survival was investigated. The present review, which contains new analyses of the previous literature, may lead to new avenues to explore in the future for the development of multitargeted miRNA-based therapies for GBM.

GDNF-RET signaling and EGR1 form a positive feedback loop that promotes tamoxifen resistance via cyclin D1

BACKGROUND

Rearranged during transfection (RET) tyrosine kinase signaling has been previously implicated in endocrine resistant breast cancer, however the mechanism by which this signaling cascade promotes resistance is currently not well described. We recently reported that glial cell-derived neurotrophic factor (GDNF)-RET signaling appears to promote a positive feedback loop with the transcription factor early growth response 1 (EGR1). Here we investigate the mechanism behind this feedback loop and test the hypothesis that GDNF-RET signaling forms a regulatory loop with EGR1 to upregulate cyclin D1 (CCND1) transcription, leading to cell cycle progression and tamoxifen resistance.

METHODS

To gain a better understanding of the GDNF-RET-EGR1 resistance mechanism, we studied the GDNF-EGR1 positive feedback loop and the role of GDNF and EGR1 in endocrine resistance by modulating their transcription levels using CRISPR-dCAS9 in tamoxifen sensitive (TamS) and tamoxifen resistant (TamR) MCF-7 cells. Additionally, we performed kinetic studies using recombinant GDNF (rGDNF) treatment of TamS cells. Finally, we performed cell proliferation assays using rGDNF, tamoxifen (TAM), and Palbociclib treatments in TamS cells. Statistical significance for qPCR and chromatin immunoprecipitation (ChIP)-qPCR experiments were determined using a student's paired t-test and statistical significance for the cell viability assay was a one-way ANOVA.

RESULTS

GDNF-RET signaling formed a positive feedback loop with EGR1 and also downregulated estrogen receptor 1 (ESR1) transcription. Upregulation of GDNF and EGR1 promoted tamoxifen resistance in TamS cells and downregulation of GDNF promoted tamoxifen sensitivity in TamR cells. Additionally, we show that rGDNF treatment activated GDNF-RET signaling in TamS cells, leading to recruitment of phospho-ELK-1 to the EGR1 promoter, upregulation of EGR1 mRNA and protein, binding of EGR1 to the GDNF and CCND1 promoters, increased GDNF protein expression, and subsequent upregulation of CCND1 mRNA levels. We also show that inhibition of cyclin D1 with Palbociclib, in the presence of rGDNF, decreases cell proliferation and resensitizes cells to TAM.

CONCLUSION

Outcomes from these studies support the hypotheses that GDNF-RET signaling forms a positive feedback loop with the transcription factor EGR1, and that GDNF-RET-EGR1 signaling promotes endocrine resistance via signaling to cyclin D1. Inhibition of components of this signaling pathway could lead to therapeutic insights into the treatment of endocrine resistant breast cancer.

CircCOL5A1 inhibits proliferation, migration, invasion, and extracellular matrix production of keloid fibroblasts by regulating the miR-877-5p/EGR1 axis

BACKGROUND

Circular RNA (circRNA) has been proved to mediate the biological functions of fibroblasts to participate in the regulation of keloid formation. However, the role of circCOL5A1 in keloid formation remains to be further confirmed.

METHODS

Primary keloid fibroblasts were isolated form keloid tissues. The expression of circCOL5A1, microRNA (miR)- 877-5p, and early growth response 1 (EGR1) were determined by quantitative real-time PCR. Transfection experiments were carried out to explore the effects of circCOL5A1, miR-877-5p, and EGR1 on cell functions. Cell proliferation, migration, invasion and apoptosis were detected using cell counting kit 8 assay, colony formation assay, transwell assay and flow cytometry. The protein levels of apoptosis markers, extracellular matrix (ECM) markers and EGR1 were measured by western blot analysis. The mechanism of circCOL5A1 was confirmed by RNA pull-down assay, dual-luciferase reporter assay and RIP assay.

RESULTS

Our data showed that circCOL5A1 was upregulated in keloid tissues and fibroblasts. Silencing of circCOL5A1 had an inhibition effect on proliferation, migration, invasion and ECM production, while had a promotion effect on apoptosis in keloid fibroblasts. MiR-877-5p could be sponged by circCOL5A1, and its overexpression could repress the biological functions of keloid fibroblasts. The rescue experiments showed that miR-877-5p inhibitor could reverse the suppressive effect of circCOL5A1 knockdown on the biological functions of keloid fibroblasts. In addition, EGR1 was a target of miR-877-5p, and its expression was positively regulated by circCOL5A1. The inhibition effect of miR-877-5p on the biological functions of keloid fibroblasts could be abolished by EGR1 overexpression.

CONCLUSION

In summary, circCOL5A1 facilitates keloid fibroblast proliferation, migration, invasion and ECM production through the miR-877-5p/EGR1 axis, thereby potentially promoting keloid formation.

FOCAD/miR-491-5p, downregulated by EGR1, function as tumor suppressor by inhibiting the proliferation and migration of gastric cancer cells

Gastric cancer is a common malignant tumor in China; however, its carcinogenesis remains unknown. Focadhesin (FOCAD) is a tumor suppressor gene in gliomas, its expression, role, and mechanism in gastric cancer have not been defined. The aim of the present study was to explore the expression pattern of FOCAD in human normal tissues and cancer tissues and elucidate the role and regulatory mechanism of Early Growth Response 1 (EGR1) in FOCAD and its intron, miR-491-5p, in gastric cancer. Immuno histochemical staining revealed that FOCAD is widely and highly expressed in normal gastric mucosa, but is absent in gastric cancer tissue. Based on an association analysis FOCAD expression was found to be negatively associated with lymph node metastasis (P = 0.004); higher FOCAD levels were associated with longer survival in patients with gastric cancer (P = 0.001). MTT, colony, Transwell chamber, and flow cytometry assays revealed that siFOCAD promoted cell proliferation, growth, and migration, and inhibited apoptosis. Furthermore, bioinformatic analysis, Fluorescence reporter gene and chromatin immunoprecipitation analyses confirmed that EGR1 binds to the promoter and negatively regulates FOCAD and miR-491-5p at the transcriptional level. The overexpression of EGR1 was also found to promote cell proliferation, growth, and migration, and inhibit apoptosis. Overall, FOCAD is specifically overexpressed in the gastric mucosa and is significantly downregulated in gastric cancer. To our knowledge, this is the first study to demonstrate that FOCAD is a tumor suppressor, higher FOCAD levels might be a better prognostic marker of gastric cancer, and FOCAD/miR-491-5p may be negatively regulated by EGR1.

PDGF signaling inhibits mitophagy in glioblastoma stem cells through N6-methyladenosine

Dysregulated growth factor receptor pathways, RNA modifications, and metabolism each promote tumor heterogeneity. Here, we demonstrate that platelet-derived growth factor (PDGF) signaling induces N⁶-methyladenosine (m⁶A) accumulation in glioblastoma (GBM) stem cells (GSCs) to regulate mitophagy. PDGF ligands stimulate early growth response 1 (EGR1) transcription to induce methyltransferase-like 3 (METTL3) to promote GSC proliferation and self-renewal. Targeting the PDGF-METTL3 axis inhibits mitophagy by regulating m⁶A modification of optineurin (OPTN). Forced OPTN expression phenocopies PDGF inhibition, and OPTN levels portend longer survival of GBM patients; these results suggest a tumor-suppressive role for OPTN. Pharmacologic targeting of METTL3 augments anti-tumor efficacy of PDGF receptor (PDGFR) and mitophagy inhibitors in vitro and in vivo. Collectively, we define PDGF signaling as an upstream regulator of oncogenic m⁶A regulation, driving tumor metabolism to promote cancer stem cell maintenance, highlighting PDGF-METTL3-OPTN signaling as a GBM therapeutic target.

CDC42EP3 promotes glioma progression via regulation of CCND1

Gliomas are the most common brain malignancies characterized by high degree of aggressiveness and high mortality. However, the underlying mechanism of glioma progression remains unclear. Here, we probed the role of CDC42EP3 (CDC42 effector protein 3) played in glioma development and its potential downstream mechanism. The expression of CDC42EP3 in tumor and normal brain tissues were examined through immunohistochemistry and we found the likelihood of CDC42EP3 overexpression was positively correlated with pathological grading. Patients with higher expression of CDC42EP3 were more likely to suffer from recurrence as well. Through constructing CDC42EP3-knockdown cell models, we discovered that silencing CDC42EP3 significantly restricted cell proliferation and migration but facilitated cell apoptosis in vitro. Inhibition on tumor growth mediated by CDC42EP3 depletion was further verified in vivo. Regarding downstream target of CDC42EP3, we found that it may positively regulate the expression of CCND1 through c-Myc-mediated transcription. Furthermore, our findings affirmed that effects of CDC42EP3 overexpression on cell proliferation, migration and apoptosis could be confined by depleting CCND1. In a word, this study reported the tumor-promoting role of CDC42EP3 in glioma progression which probably functioned through targeting CCND1.

Low EGR1 expression predicts poor prognosis in clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is resistant to conventional therapy due to the deletion of the von Hippel-Lindau (VHL) gene, and novel treatment options are urgently needed. Here, using tissue microarray analysis of 445 cancer tissues and 326 adjacent normal renal tissues obtained from patients with ccRCC, we present the early growth response-1 (EGR1) protein levels are significantly decreased in ccRCC cancer tissues. Consistently, the EGR1 mRNA expression also decreased in cancer tissues based on the transcriptomic data for 599 tumor and normal samples from The Cancer Genome Atlas. Moreover, Patients with ccRCC presenting low EGR1 expression are more prone to exhibit metastasis and a poor prognosis than those with high EGR1 expression. By multivariate Cox regression analysis, EGR1 is determined to serve as an independent prognostic factor for patients with ccRCC. Further cellular biochemical function analyses show that EGR1 may inhibit proliferation, invasion and metastasis of ccRCC. These findings will deepen our understanding of EGR1 function and shed light on precise treatment for ccRCC patients.

Prognostic role of EGR1 in breast cancer: a systematic review

EGR1 (early growth response 1) is dysregulated in many cancers and exhibits both tumor suppressor and promoter activities, making it an appealing target for cancer therapy. Here, we used a systematic multiomics analysis to review the expression of EGR1 and its role in regulating clinical outcomes in breast cancer (BC). EGR1 expression, its promoter methylation, and protein expression pattern were assessed using various publicly available tools. COSMIC-based somatic mutations and cBioPortal-based copy number alterations were analyzed, and the prognostic roles of EGR1 in BC were determined using Prognoscan and Kaplan-Meier Plotter. We also used bc-GenEx-Miner to investigate the EGR1 co-expression profile. EGR1 was more often downregulated in BC tissues than in normal breast tissue, and its knockdown was positively correlated with poor survival. Low EGR1 expression levels were also associated with increased risk of ER+, PR+, and HER2-BCs. High positive correlations were observed among EGR1, DUSP1, FOS, FOSB, CYR61, and JUN mRNA expression in BC tissue. This systematic review suggested that EGR1 expression may serve as a prognostic marker for BC patients and that clinicopathological parameters influence its prognostic utility. In addition to EGR1, DUSP1, FOS, FOSB, CYR61, and JUN can jointly be considered prognostic indicators for BC.

Oncogenic role of early growth response-1 in liver cancer through the regulation of the microRNA-675/sestrin 3 and the Wnt/β-catenin signaling pathway

Early growth response-1 (EGR1) is a multi-domain protein and an immediate early transcription factor that is induced during liver injury and controls the expression of a variety of genes implicated in metabolism, cell proliferation, and tumorigenesis. Liver cancer (LC) is a highly malignant disease with high mortality worldwide. This study focused on the function of EGR1 in LC development and the mechanism of action. Two LC-related datasets GSE101728 and GSE138178 downloaded from the Gene Expression Omnibus (GEO) database were used for identification of key genes involved in cancer progression. A microarray analysis was conducted to identify differentially expressed microRNAs (miRNAs) after EGR1 knockdown. The target gene of miR-675 was identified by integrated analysis. EGR1 and miR-675 were highly expressed, whereas sestrin 3 (SESN3) was poorly expressed in LC tissues and cells. High EGR1 expression was associated with poor liver function and disease severity in patients with LC. Knockdown of EGR1 weakened proliferation and invasiveness of LC cells. EGR1 bound to the miR-675 promoter and increased its transcription, and miR-675 bound to SESN3 mRNA to induce its downregulation. miR-675 upregulation promoted the malignance of LC cells, but further upregulation of SESN3 reduced invasiveness of cells. SESN3 was enriched in the Wnt/β-catenin signaling. EGR1 and miR-675 activated the Wnt/β-catenin through downregulating SESN3. This study demonstrated that EGR1 promotes the malignant behaviors of LC cells through mediating the miRNA-675/SESN3/Wnt/β-catenin axis.

A Novel miRNA-mRNA Axis Involves in Regulating Transcriptional Disorders in Pancreatic Adenocarcinoma

Background

Currently, there is still a lack of understanding about the mechanism and therapeutic targets of pancreatic adenocarcinoma (PAAD). The potential of miRNA-mRNA networks for the identification of regulatory mechanisms involved in PAAD development remains unexplored.

Methods

We compared differentially expressed miRNAs (DEMIs) and differentially expressed genes (DEGs) in PAAD and normal tissues from the Gene Expression Omnibus (GEO) database. Transcription factors (TFs) were obtained from FunRich. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses of DEGs and DEMIs were implemented using Database for Annotation, Visualization and Integrated Discovery (DAVID). Then, key miRNAs and targeted mRNAs were identified by assessment of their expression and prognosis in UALCAN and Kaplan-Meier plotters. In the last step, the candidate miRNA-mRNA selected was confirmed by real-time quantitative polymerase chain reaction (qRT-PCR).

Results

We distinguished 62 significant DEMIs, 1314 upregulated DEGs, and 1110 downregulated DEGs. The top 10 TFs were identified. In total, there were 160 hub genes obtained by intersecting the set of 2224 predicted targets with the set of significant DEGs. And we selected 8 key miRNAs. Furthermore, low expression of miR-455-3p in PAAD tissue was closely connected with poor prognosis, and only 5 target mRNAs were predicted to be increased in PAAD tissue with poor prognosis. Therefore, a novel miRNA-hub gene regulatory network in PAAD was constructed. Finally, in vitro experiments indicated that miR-455-3p expression was decreased in PAAD sample. HOXC4, DLG4, DYNLL1 and FBXO45 were validated by qRT-PCR as highly probable targets of miR-455-3p.

Conclusion

A novel miRNA-mRNA axis has been discovered that may be involved in the regulation of transcriptional disorders and affected the survival of PAAD patients, which would provide a novel strategy for the treatment of PAAD.

A novel regulatory loop miR-101/ANXA2/EGR1 mediates malignant characteristics of liver cancer stem cells

Increasing evidence suggests that liver cancer stem cells (LCSCs) are the cellular determinants that promote tumor recurrence and metastases. Aberrantly expressed miRNAs were identified in LCSCs and found to play a significant role in modulating biological characteristics of LCSCs. In this study, we implemented miRNA microarrays in CD133+ LCSCs and found miR-101 expression was downregulated. Increasing miR-101 expression repressed the metastasis and tumorigenic potential in LCSCs. Further investigations showed that ANXA2 was a novel target of miR-101. And we revealed that ANXA2 plays a critical role in acceleration of cell cycle and enhancing the migration and invasion abilities of LCSCs. Elevated ANXA2 increased activation of extracellular signal-regulated kinase (ERK) which regulated SOX2 and cell cycle-related kinases. Moreover, ERK phosphorylation inhibited the expression of early growth response 1 (EGR1) which in turn restrained the transcription of miR-101. In vivo experiments, overexpression of miR-101 produced potent inhibitory effects on the growth of LCSCs xenograft tumors as well as ANXA2 knockdown. Taken together, our findings suggest a novel regulatory loop miR-101/ANXA2/EGR1 in LCSCs and may serve as potential therapeutic targets in liver cancer.

Predictive Study of the Active Ingredients and Potential Targets of Codonopsis pilosula for the Treatment of Osteosarcoma via Network Pharmacology

Osteosarcoma (OS) is the most common type of primary bone tumor in children and adults. Dangshen (Codonopsis pilosula) is a traditional Chinese medicine commonly used in the treatment of OS worldwide. However, the molecular mechanisms of Dangshen in OS remain unclear. Hence, in this study, we aimed to systematically explore the underlying mechanisms of Dangshen in the treatment of OS. Our study adopted a network pharmacology approach, focusing on the identification of active ingredients, drug target prediction, gene collection, gene ontology (GO) enrichment, Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment, and other network tools. The network analysis identified 15 active compounds in Dangshen that were linked to 48 possible therapeutic targets related to OS. The results of the gene enrichment analysis show that Dangshen produces a therapeutic effect in OS likely by regulating multiple pathways associated with DNA damage, cell proliferation, apoptosis, invasion, and migration. Based on the network pharmacology approach, we successfully predicted the active compounds and their respective targets. In addition, we illustrated the molecular mechanisms that mediate the therapeutic effect of Dangshen in OS. These findings may aid in the development of novel targeted therapies for OS in the future.

EGR1/2 Inhibits Papillary Thyroid Carcinoma Cell Growth by Suppressing the Expression of PTEN and BAX

Early growth response (EGR) proteins have been reported to be involved in cell growth and apoptosis in a variety of cancer types and could inhibit tumor development. However, the role of EGR1/2 in papillary thyroid carcinoma (PTC) has not been elucidated. The expression pattern of EGR1/2 in adjacent tissues and cancer tissues and the clinical prognosis of EGR1/2 were analyzed by using the samples from TCGA database. The cell viability was detected by MTT assay. Luciferase reporter assay was used to demonstrate the binding of EGR1/2 to the target gene promotor region. Our results showed that EGR1/2 was significantly downregulated in tumor tissues and correlated with poor prognosis. Overexpression of EGR1/2 inhibited proliferation of IHH-4 and BCPAP cells, and knockdown of EGR1/2 showed a reverse effect. Overexpression of EGR1 or EGR2 promoted phosphatase and tension homolog (PTEN) or Bcl-2-associated X (BAX) expression, and EGR1 or EGR2 was able to directly bind to the promoter region of PTEN or BAX. In conclusion, we found that the altered expression of EGR1/2 affected the proliferation of PTC cells and regulated the expression of PTEN and BAX.

SOCS2 is a potential prognostic marker that suppresses the viability of hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer-associated mortality worldwide. Thus, there is an urgent requirement to identify novel diagnostic and prognostic biomarkers for this disease. The present study aimed to identify the hub genes associated with the progression and prognosis of patients with HCC. A total of three expression profiles of HCC tissues were extracted from the Gene Expression Omnibus (GEO) database, followed by the identification of differentially expressed genes (DEGs) using the GEO2R method. The identified DEGs were assessed for survival significance using Kaplan-Meier analysis. Among the 15 identified DEGs in HCC tissues [cytochrome P450 family 39 subfamily A member 1, cysteine rich angiogenic inducer 61, Fos proto-oncogene, forkhead transcription factor 1 (FOXO1), growth arrest and DNA damage inducible β, Inhibitor of DNA binding 1, interleukin-1 receptor accessory protein, metallothionein-1M, pleckstrin homology-like domain family A member 1, Rho family GTPase 3, serine dehydratase, suppressor of cytokine signaling 2 (SOCS2), tyrosine aminotransferase (TAT), S100 calcium-binding protein P and serine protease inhibitor Kazal-type 1 (SPINK1)]. Low expression levels of FOXO1, SOCS2 and TAT and high SPINK1 expression indicated poor survival outcomes for patients with HCC. In addition, SOCS2 was associated with distinct stages of HCC progression in patients and presented optimal diagnostic value. In vitro functional experiments indicated that overexpression of SOCS2 inhibited HCC cell proliferation and migration. Taken together, the results of the present study suggest that SOCS2 may act as a valuable prognostic marker that is closely associated with HCC progression.

EGR1 promotes stemness and predicts a poor outcome of uterine cervical cancer by inducing SOX9 expression

BACKGROUND

Early growth response-1 (EGR1) is a transcription factor involved in the progression of several cancer types. However, the expression and clinical significance of EGR1 in uterine cervical cancer (CC) have not been elucidated.

OBJECTIVE

To investigate the expression, clinical significance and prognostic value of EGR1 in CC.

METHODS

The expression of EGR1 was detected in 13 CCs and paired adjacent tissues with qRT-PCR and in 144 CC tissues with immunohistochemistry (IHC). The IHC scores were used to divide the patients into subsets with low and high EGR1 expression. The correlations between the EGR1 expression and clinicopathological factors were analyzed with the chi-square test, and the prognostic significance of EGR1 expression was evaluated with univariate and multivariate analyses. The functions of EGR1 in the proliferation, invasion and stemness of CC cells were investigated, and the molecular mechanism was assessed by in vitro experiments.

RESULTS

High expression of EGR1 was significantly associated with low survival rates of CC. EGR1 is an independent prognostic biomarker of CC, and its high expression predicted a poor outcome. EGR1 facilitated stemness and thus promoted proliferation and invasion of CC cells. SOX9 played an essential role in the EGR1-induced progression of CC cells.

CONCLUSIONS

EGR1 is an independent prognostic biomarker of CC. High EGR1 expression promoted proliferation, invasion and stemness by increasing SOX9 expression in CC cells. Our results suggested that the EGR1-SOX9 axis may be a potential drug target and that blocking the EGR1-SOX9 axis may be a possible approach to treating CC.

M2 macrophage-derived exosomal microRNAs inhibit cell migration and invasion in gliomas through PI3K/AKT/mTOR signaling pathway

Background

Glioma, the most common primary brain tumor, account Preparing figures for 30 to 40% of all intracranial tumors. Herein, we aimed to study the effects of M2 macrophage-derived exosomal microRNAs (miRNAs) on glioma cells.

Methods

First, we identified seven differentially expressed miRNAs in infiltrating macrophages and detected the expression of these seven miRNAs in M2 macrophages. We then selected hsa-miR-15a-5p (miR-15a) and hsa-miR-92a-3p (miR-92a) for follow-up studies, and confirmed that miR-15a and miR-92a were under-expressed in M2 macrophage exosomes. Subsequently, we demonstrated that M2 macrophage-derived exosomes promoted migration and invasion of glioma cells, while exosomal miR-15a and miR-92a had the opposite effects on glioma cells. Next, we performed the target gene prediction in four databases and conducted target gene validation by qRT-PCR, western blot and dual luciferase reporter gene assays.

Results

The results revealed that miR-15a and miR-92a were bound to CCND1 and RAP1B, respectively. Western blot assays demonstrated that interference with the expression of CCND1 or RAP1B reduced the phosphorylation level of AKT and mTOR, indicating that both CCND1 and RAP1B can activate the PI3K/AKT/mTOR signaling pathway.

Conclusion

Collectively, these findings indicate that M2 macrophage-derived exosomal miR-15a and miR-92a inhibit cell migration and invasion of glioma cells through PI3K/AKT/mTOR signaling pathway.

Supplementary information

The online version contains supplementary material available at 10.1186/s12967-021-02766-w.

Identification of miRNAs as diagnostic and prognostic markers in hepatocellular carcinoma

The development of high-throughput technologies has yielded a large amount of data from molecular and epigenetic analysis that could be useful for identifying novel biomarkers of cancers. We analyzed Gene Expression Omnibus (GEO) DataSet micro–ribonucleic acid (miRNA) profiling datasets to identify miRNAs that could have value as diagnostic and prognostic biomarkers in hepatocellular carcinoma (HCC). We adopted several computing methods to identify the functional roles of these miRNAs. Ultimately, via integrated analysis of three GEO DataSets, three differential miRNAs were identified as valuable markers in HCC. Combining the results of receiver operating characteristic (ROC) analyses and Kaplan–Meier Plotter (KM) survival analyses, we identified hsa-let-7e as a novel potential biomarker for HCC diagnosis and prognosis. Then, we found via quantitative reverse-transcription polymerase chain reaction (RT-qPCR) that let-7e was upregulated in HCC tissues and that such upregulation was significantly associated with poor prognosis in HCC. The results of functional analysis indicated that upregulated let-7e promoted tumor cell growth and proliferation. Additionally, via mechanistic analysis, we found that let-7e could regulate mitochondrial apoptosis and autophagy to adjust and control cancer cell proliferation. Therefore, the integrated results of our bioinformatics analyses of both clinical and experimental data showed that let-7e was a novel biomarker for HCC diagnosis and prognosis and might be a new treatment target.

Upregulation of KIF11 in TP53 Mutant Glioma Promotes Tumor Stemness and Drug Resistance

Glioma is the most common type of primary brain malignancy with high morbidity and mortality, but little is known about its pathological mechanisms. Kinesin family member 11 (KIF11) is a key driver of malignancy in glioblastoma, a grade IV glioma, but its involvement in glioma chemoresistance remains to be determined. We accessed the TCGA open datasets, collected glioma tumor tissue samples, and analyzed the expression of KIF11 in glioma patients. Meanwhile, the correlation between KIF11 and survival outcomes was determined by the Kaplan-Meier analysis. The role of KIF11 in glioma tumor cell function was assessed in an in vitro knockdown and overexpressing system. Here, we found that KIF11 was upregulated in glioma tumors and negatively correlated with overall survival outcomes via analyzing the open datasets. KIF11 was negatively correlated with TP53 expression. Furthermore, KIF11 promoted the stemness in glioma cells, accompanied by increased cell proliferation and chemoresistance. Mechanistically, we found that KIF11 promoted cell cycle progression via upregulating cyclin expression.

Curcumin promotes osteogenic differentiation of human periodontal ligament stem cells by inducting EGR1 expression

OBJECTIVE

Human periodontal ligament stem cells (hPDLSCs) attract attention for the periodontal regeneration therapy. Curcumin may promote osteogenic differentiation of hPDLSCs. This research aims to elucidate whether Curcumin displays promoting osteogenic differentiation and its mechanism.

METHODS

The hPDLSCs were isolated from human periodontal ligament by immunomagnetic beads, identified with immumofluorescence. hPDLSCs were treated with 0, 5, 10, 20, 50, 100 μmol/L Curcumin. The early growth response gene 1 (EGR1) siRNA or plasmind were tranfected into the hPDLSCs. The viability, Alkaline Phosphatase (ALP) activity and mineralizaiton level of hPDLSCs were measured with 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-di-phenytetrazoliumromide (MTT) assay, ALP Assay Kit or Alizarin Red staining. The expression of EGR1, RUNX family transcription factor 2 (Runx2), bone gamma-carboxyglutamate protein (OC), secreted phosphoprotein 1 (OPN) and collagen type I alpha 1 chain (Collagen I), in hPDLSC were determined by Western blotting and quantitative reverse transcription-polymerase chain reaction.

RESULTS

The isolated hPDLSCs were spindle or irregular, arranged in radial shape and shown positive expression of STRO-1, CD146 and Vimentin. Curcumin 10 μmol/L treatment maximal promoting the cells viability, ALP activities, mineralization, and levels of Runx2, OC, OPN, Collagen I and EGR-1 in hPDLSCs. EGR-1 siRNA transfection inversed Curcumin's promoting effect on ALP activities, mineralization, and levels of Runx2, OC, OPN, Collagen I and EGR-1 in hPDLSCs. While the EGR-1 plasmid transfection enhanced Curcumin's promoting effect on these parameters of hPDLSCs.

CONCLUSION

Curcumin promotes the osteogenic differentiation of hPDLSCs, which may work through the EGR1. Curcumin may be a promising medicine for periodontitis treatment and periodontal regeneration.

MiR-124-3p reduces angiotensin II-dependent hypertension by down-regulating EGR1

Through previous literature studies, we found that miR-124-3p may be associated with hypertension. Therefore, we investigated the relationship between miR-124-3p and hypertension in Human Umbilical Vein Endothelial Cells (HUVECs) induced by angiotensin II (AngII). AngII-induced HUVECs model was constructed and the expression of miR-124-3p was detected by qRT-PCR. After transfected cells, apoptosis and ROS production were detected by flow cytometry, caspase-3 kit, and DCFH-DA staining. The target genes of miR-124-3p were predicted and verified by TargrtScan, Luciferase assay, qRT-PCR, and western blot. After silencing Early growth response factor 1 (siEGR1), its effects on apoptosis and ROS production were explored. Finally, the rescue experiments were conducted to explore the mechanism of miR-124-3p to reduce hypertension. MiR-124-3p was underexpressed in the cell model. In Ang II-induced HUVECs, the number of apoptosis increased, the content of caspase-3 was higher, and ROS production increased. However, these effects could be partially inhibited by miR-124-3p mimic. EGR1 was down-regulated by miR-124-3p, and siEGR1 was able to inhibit apoptosis and ROS production of cell model. In the final rescue experiments, miR-124-3p partially reversed the effect of Ang-II on the viability, migration, invasion and apoptosis and ROS production in HUVECs by down-regulating EGR1. MiR-124-3p inhibits Ang II-induced apoptosis and ROS production in HUVECs by down-regulating EGR1.

Bioinformatic analysis reveals MIR502 as a potential tumour suppressor in ovarian cancer

BACKGROUND

Ovarian cancer (OC) is a major cause of death among women due to the lack of early screening methods and its complex pathological progression. Increasing evidence has indicated that microRNAs regulate gene expression in tumours by interacting with mRNAs. Although the research regarding OC and microRNAs is extensive, the vital role of MIR502 in OC remains unclear.

METHODS

We integrated two microRNA expression arrays from GEO to identify differentially expressed genes. The Kaplan-Meier method was used to screen for miRNAs that had an influence on survival outcome. Upstream regulators of MIR502 were predicted by JASPAR and verified by ChIP-seq data. The LinkedOmics database was used to study genes that were correlated with MIR502. Gene Set Enrichment Analysis (GSEA) was conducted for functional annotation with GO and KEGG pathway enrichment analyses by using the open access WebGestalt tool. We constructed a PPI network by using STRING to further explore the core proteins.

RESULTS

We found that the expression level of MIR502 was significantly downregulated in OC, which was related to poor overall survival. NRF1, as an upstream regulator of MIR502, was predicted by JASPAR and verified by ChIP-seq data. In addition, anti-apoptosis and pro-proliferation genes in the Hippo signalling pathway, including CCND1, MYC, FGF1 and GLI2, were negatively regulated by MIR502, as shown in the GO and KEGG pathway enrichment results. The PPI network further demonstrated that CCND1 and MYCN were at core positions in the development of ovarian cancer.

CONCLUSIONS

MIR502, which is regulated by NRF1, acts as a tumour suppressor gene to accelerate apoptosis and suppress proliferation by targeting the Hippo signalling pathway in ovarian cancer.

Ca2+ as a therapeutic target in cancer

Ca2+ is a ubiquitous and dynamic second messenger molecule that is induced by many factors including receptor activation, environmental factors, and voltage, leading to pleiotropic effects on cell function including changes in migration, metabolism and transcription. As such, it is not surprising that aberrant regulation of Ca2+ signals can lead to pathological phenotypes, including cancer progression. However, given the highly context-specific nature of Ca2+-dependent changes in cell function, delineation of its role in cancer has been a challenge. Herein, we discuss the distinct roles of Ca2+ signaling within and between each type of cancer, including consideration of the potential of therapeutic strategies targeting these signaling pathways.

Epidermal growth factor regulates the development of stem and progenitor Leydig cells in rats

Epidermal growth factor (EGF) has many physiological roles. However, its effects on stem and progenitor Leydig cell development remain unclear. Rat stem and progenitor Leydig cells were cultured with different concentrations of EGF alone or in combination with EGF antagonist, erlotinib or cetuximab. EGF (1 and 10 ng/mL) stimulated the proliferation of stem Leydig cells on the surface of seminiferous tubules and isolated CD90⁺ stem Leydig cells and progenitor Leydig cells but it blocked their differentiation. EGF also exerted anti‐apoptotic effects of progenitor Leydig cells. Erlotinib and cetuximab are able to reverse EGF‐mediated action. Gene microarray and qPCR of EGF‐treated progenitor Leydig cells revealed that the down‐regulation of steroidogenesis‐related proteins (Star and Hsd3b1) and antioxidative genes. It was found that EGF acted as a proliferative agent via increasing phosphorylation of AKT1. In conclusion, EGF stimulates the proliferation of rat stem and progenitor Leydig cells but blocks their differentiation.

SNGH16 regulates cell autophagy to promote Sorafenib Resistance through suppressing miR-23b-3p via sponging EGR1 in hepatocellular carcinoma

OBJECTIVE

Tumor cells could acquire drug resistance through cell autophagy. This study aimed to explore the role of SNHG16 in sorafenib-resistant HCC cells and its mechanism with miR-23b-3p.

METHODS

The sorafenib-resistant Hep3B cell model was established. The SNHG16 and miR-23b-3p gene expressions were determined in normal HCC and sorafenib-resistant HCC tissues. Detection of the expression of SNHG16 and miR-23b-3p and its respective correlation with survival rate were performed. Target genes to SNHG16 and miR-23b-3p were predicted, and verified by dual-fluorescent reporter assay. The effects of SNHG16 and miR-23b-3p on SNHG16, miR-23b-3p, EGR1 expression, viability, apoptosis as well as LC3II/LC3 expression in Hep3B and Hep3B/So cells were detected by qRT-PCR, CCK-8, flow cytometry, and western blot. In in vivo studies, the NOD/SCID mice model was established to explore the effects of Hep3B and Hep3B/So cells with inhibited SNHG16 or miR-23b-3p on tumor size, EGR1 expression, and autophagy.

RESULTS

High SNHG16 expression in HCC-resistant tissues and low miR-23b-3p expression in all HCC tissues were detected, and the two were negatively correlated. Low SNHG16 and high miR-23b-3p were related to a high survival rate of HCC patients. Moreover, SNHG16 overexpression promoted Hep3B/So cell viability and autophagy, suppressed apoptosis by inhibiting miR-23b-3p expression through up-regulating EGR1, however, the effect of si-SNHG16 was opposite. In in vivo studies, miR-23b-3p inhibitor suppressed the high sorafenib sensitivity in Hep3B/So cells caused by SNHG16 silencing through promoting viability, autophagy, and suppressing apoptosis.

CONCLUSION

SNHG16 promotes Hep3B/So cell viability, autophagy, and inhibits apoptosis to maintain its resistance to sorafenib through regulating the expression of miR-23b-3p via sponging EGR1.

Super-enhancers: A new frontier for glioma treatment

Glioma is the most common primary malignant tumor in the human brain. Although there are a variety of treatments, such as surgery, radiation and chemotherapy, glioma is still an incurable disease. Super-enhancers (SEs) are implicated in the control of tumor cell identity, and they promote oncogenic transcription, which supports tumor cells. Inhibition of the SE complex, which is required for the assembly and maintenance of SEs, may repress oncogenic transcription and impede tumor growth. In this review, we discuss the unique characteristics of SEs compared to typical enhancers, and we summarize the recent advances in the understanding of their properties and biological role in gene regulation. Additionally, we highlight that SE-driven lncRNAs, miRNAs and genes are involved in the malignant phenotype of glioma. Most importantly, the application of SE inhibitors in different cancer subtypes has introduced new directions in glioma treatment.

MicroRNA‑628‑5p inhibits cell proliferation and induces apoptosis in colorectal cancer through downregulating CCND1 expression levels

MicroRNA (miR)-628-5p serves as an antitumor gene in a variety of cancers; however, the role of miR-628-5p in colorectal cancer remains largely unclear. The purpose of this study was to investigate the role and mechanism of miR-628-5p in colorectal cancer. Reverse transcription-quantitative PCR (RT-qPCR), colony formation assays and flow cytometric analysis were used to determine the expression levels of miR-628-5p in colorectal cancer tissues and cell lines, and the proliferative ability of colorectal cancer cells. TargetScan version 7.2 and dual-luciferase reporter assay were performed to predict and confirm miR-628-5p target genes. The expression levels of cyclin D1 (CCND1) and related genes were determined using RT-qPCR or/and western blotting analysis. miR-628-5p mimics and CCND1 plasmids were used to overexpress miR-628-5p and CCND1; it was demonstrated that the expression levels of miR-628-5p were significantly downregulated in colorectal cancer tissues and cell lines. miR-628-5p mimic-transfected cells inhibited the proliferation and induced apoptosis of HT-29 cells. CCND1, a downstream effector of miR-628-5p, promoted the proliferation and suppressed apoptosis of HT-29 cells, and the effects were reversed by miR-628-5p mimics. In conclusion, the present study suggested that colorectal cancer progression may be regulated through the miR-628-5p/CCND1 axis, and miR-628-5p could be used as a potential diagnostic and prognostic biomarker for colorectal cancer.

Expression and prognostic analyses of early growth response proteins (EGRs) in human breast carcinoma based on database analysis

Background

Early growth response proteins (EGRs), as a transcriptional regulatory family, are involved in the process of cell growth, differentiation, apoptosis, and even carcinogenesis. However, the role of EGRs in tumors, their expression levels, and their prognostic value remain unclear.

Methods

Using the Oncomine database, Kaplan–Meier Plotter, bcGenExMiner v4.2, cBioPortal, and other tools, the association between the survival data of breast carcinoma (BC) patients and transcriptional levels of four EGRs was investigated.

Results

According to the Oncomine database, in comparison to normal tissues, the expression level of EGR2/3 mRNA in BC tissues was decreased, but there was no difference in the expression level of EGR4 mRNA. On the basis of the Scarff-Bloom-Richardson (SBR) grading system, the downregulated expression level of EGR1/2/3 and upregulated expression level of EGR4 were correlated with an increased histological differentiation level, with significant differences (p < 0.05). Kaplan–Meier curves suggest that a reduction in EGR2/3 mRNA expression is related to recurrence-free survival (RFS) in BC patients. In addition, the mRNA expression level of EGR1/2/3 was related to metastatic relapse-free survival (MRFS) in BC patients with metastatic recurrence (p < 0.05).

Conclusion

EGR1/2/3 can be utilized as an important factor for evaluating prognosis and may be relevant to diagnosis. EGR4 may play a role in the occurrence and development of BC. The specific function and mechanism of EGRs in BC deserve further study.

Transcription factor early growth response-1 plays an oncogenic role in salivary gland pleomorphic adenoma

OBJECTIVES

Although abnormal expression of early growth response-1 (Egr1) has been revealed in various human solid tumors, the functions and potential mechanisms of Egr1 in the progression of salivary gland pleomorphic adenoma (SGPA) are not entirely understood.

RESULTS

An elevated expression of Egr1 was observed both in the human salivary gland pleomorphic adenoma tissues and tumor-initiating cell (TIC) cells, when compared with control group. By loss-of-function assay, the proliferation and invasion capacities of TICs were inhibited, while the cell apoptosis was promoted, which were further evidenced by the protein expression analysis of several key apoptosis-related regulators. Furthermore, TICs with Mithramycin A (an Egr1 inhibitor) treatment achieved the same effects of endogenous Egr1 knockdown.

CONCLUSIONS

All these data collectively suggest that Egr1 act as an oncogenic factor in salivary gland pleomorphic adenoma, which may be a potential target for the treatment of SGPA.

Targets and mechanisms of sulforaphane derivatives obtained from cruciferous plants with special focus on breast cancer - contradictory effects and future perspectives

Breast cancer is the most common type of cancer among women. Therefore, discovery of new and effective drugs with fewer side effects is necessary to treat it. Sulforaphane (SFN) is an organosulfur compound obtained from cruciferous plants, such as broccoli and mustard, and it has the potential to treat breast cancer. Hence, it is vital to find out how SFN targets certain genes and cellular pathways in treating breast cancer. In this review, molecular targets and cellular pathways of SFN are described. Studies have shown SFN inhibits cell proliferation, causes apoptosis, stops cell cycle and has anti-oxidant activities. Increasing reactive oxygen species (ROS) produces oxidative stress, activates inflammatory transcription factors, and these result in inflammation leading to cancer. Increasing anti-oxidant potential of cells and discovering new targets to reduce ROS creation reduces oxidative stress and it eventually reduces cancer risks. In short, SFN effectively affects histone deacetylases involved in chromatin remodeling, gene expression, and Nrf2 anti-oxidant signaling. This review points to the potential of SFN to treat breast cancer as well as the importance of other new cruciferous compounds, derived from and isolated from mustard, to target Keap1 and Akt, two key regulators of cellular homeostasis.

Impact of chronically alternating light-dark cycles on circadian clock mediated expression of cancer (glioma)-related genes in the brain

Disruption of the circadian rhythm is a risk factor for cancer, while glioma is a leading contributor to mortality worldwide. Substantial efforts are being undertaken to decrypt underlying molecular pathways. Our understanding of the mechanisms through which disrupted circadian rhythm induces glioma development and progression is incomplete. We, therefore, examined changes in the expression of glioma-related genes in the mouse brain after chronic jetlag (CJL) exposure. A total of 22 candidate tumor suppressor (n= 14) and oncogenes (n= 8) were identified and analyzed for their interaction with clock genes. Both the control and CJL groups were investigated for the expression of candidate genes in the nucleus accumbens, hippocampus, prefrontal cortex, hypothalamus, and striatum of wild type, Bmal1-/- and Cry1/2 double knockout male mice. We found significant variations in the expression of candidate tumor suppressor and oncogenes in the brain tissues after CJL treatment in the wild type, Bmal1-/- and Cry1/2 double knockout mice. In response to CJL treatment, some of the genes were regulated in the wild type, Bmal1-/- and Cry1/2 similarly. However, the expression of some of the genes indicated their association with the functional clock. Overall, our result suggests a link between CJL and gliomas risk at least partially dependent on the circadian clock. However, further studies are needed to investigate the molecular mechanism associated with CJL and gliomas.

DNA Methylation Readers and Cancer: Mechanistic and Therapeutic Applications

DNA methylation is a major epigenetic process that regulates chromatin structure which causes transcriptional activation or repression of genes in a context-dependent manner. In general, DNA methylation takes place when methyl groups are added to the appropriate bases on the genome by the action of "writer" molecules known as DNA methyltransferases. How these methylation marks are read and interpreted into different functionalities represents one of the main mechanisms through which the genes are switched "ON" or "OFF" and typically involves different types of "reader" proteins that can recognize and bind to the methylated regions. A tightly balanced regulation exists between the "writers" and "readers" in order to mediate normal cellular functions. However, alterations in normal methylation pattern is a typical hallmark of cancer which alters the way methylation marks are written, read and interpreted in different disease states. This unique characteristic of DNA methylation "readers" has identified them as attractive therapeutic targets. In this review, we describe the current state of knowledge on the different classes of DNA methylation "readers" identified thus far along with their normal biological functions, describe how they are dysregulated in cancer, and discuss the various anti-cancer therapies that are currently being developed and evaluated for targeting these proteins.

KLF5 functions in proliferation, differentiation, and apoptosis of chicken satellite cells

KLF5 is an important regulator of cell proliferation, differentiation, and apoptosis in mammals. Little is known about the function of KLF5 in the regulation of chicken. Hence, qPCR was used to detect the expression of KLF5 in different tissues of chicken. And chicken skeletal muscle satellite cells (SMSCs) were transfected KLF5-specific small interfering RNA (siRNA) to assay SMSCs' proliferation, differentiation, and apoptosis. The results showed that KLF5 expressed higher in skeletal muscle than in the other tissues of chicken. Knockdown of KLF5 significantly inhibited the differentiation and increased apoptosis of chicken SMSCs, but it had no significant effect on proliferation of SMSCs. These results indicate that KLF5 plays an essential role during myogenesis, which will affect muscle repair and muscle regeneration, and may ameliorate muscle aging or sarcopenia.

MicroRNA-466 inhibits osteosarcoma cell proliferation and induces apoptosis by targeting CCND1

Emerging pieces of evidence indicate that microRNA-466 (miR-466) serves as a tumor suppressor in several human tumors, including colorectal cancer and prostate cancer. However, whether miR-466 is involved in osteosarcoma (OS) progression remains largely unknown. The present study demonstrated that miR-466 was significantly downregulated in OS tissues and cell lines. Furthermore, it was revealed that the expression of miR-466 was negatively correlated with OS severity. Moreover, low miR-466 expression in patients with OS predicted poor prognosis. Through functional experiments, miR-466 overexpression significantly inhibited the proliferation and cell cycle of OS cells while inducing cellular apoptosis. In terms of mechanism, it was revealed that CCND1 was a target of miR-466 in OS cells. miR-466 overexpression suppressed CCND1 expression in OS cells. A reverse association was observed between the expression levels of miR-466 and CCND1 in OS tissues. Furthermore, CCND1 restoration in OS cells significantly rescued the effects of miR-466 on cellular proliferation and apoptosis. Overall, the results of the present study demonstrated that miR-466 suppressed OS progression by targeting CCND1, suggesting that miR-466 may be a promising biomarker and therapeutic target for OS prognosis and treatment.

Enhanced efficacy of histone deacetylase inhibitor combined with bromodomain inhibitor in glioblastoma

Background

Glioblastoma (GBM) is the most common and most malignant primary brain cancer in adults. Despite multimodality treatment, the prognosis is still poor. Therefore, further work is urgently required to discover novel therapeutic strategies for GBM treatment.

Methods

The synergistic effects of cotreatment with the histone deacetylase (HDAC) inhibitor panobinostat and bromodomain inhibitor JQ1 or OTX015 were validated using cell viability assays in GBM cell lines. Furthermore, the inhibitory mechanisms were investigated via an EdU proliferation assay, an apoptosis assay, qPCR, Western blot and RNAseq analyses.

Results

We found that the cotreatment with panobinostat and JQ1 or OTX015 synergistically inhibited cell viability in GBM cells. The cotreatment with panobinostat and JQ1 or OTX015 markedly inhibited cell proliferation and induced apoptosis in GBM cells. Compared with treatment with each drug alone, the cotreatment with panobinostat and JQ1 induced more profound caspase 3/7 activation and cytotoxicity. Mechanistic investigation showed that combination of panobinostat with JQ1 or OTX015 results in stronger repression of GBM-associated oncogenic genes or pathways as well as higher induction of GBM-associated tumor-suppressive genes.

Conclusion

Our study demonstrated that HDAC inhibitor and bromodomain inhibitor had synergistical efficacy against GBM cells. The cotreatment with HDAC inhibitor and bromodomain inhibitor warrants further attention in GBM therapy.

Gene profiling involved in fate determination of salivary gland type in mouse embryogenesis

Salivary gland (SG) development involves dynamic epithelial-mesenchymal interactions resulting in the formation of highly branched epithelial structures that produce and secrete saliva. The SG epithelium differentiates into saliva-producing terminal buds, i.e., acini, and transporting ducts. Most studies on the salivary gland have focused on branching morphogenesis; however, acinar cell differentiation underlying the determination of serous or mucous salivary glands is unclear. The objective of this study was to identify the mesenchymal signaling molecules involved in the epithelial differentiation of the salivary gland type as serous or mucous. Salivary glands undergoing stage-specific development, including the parotid gland (PG) and the sublingual gland (SLG) at embryonic day 14.5 (E14.5) were dissected. The glands were treated with dispase II to separate the epithelium and the mesenchyme. RNA from mesenchyme was processed for microarray analysis. Thereafter, microarray data were analyzed to identify putative candidate molecules involved in salivary gland differentiation and confirmed via quantitative reverse transcription polymerase chain reaction. The microarray analysis revealed the expression of 31,873 genes in the PG and SLG mesenchyme. Of the expressed genes 21,026 genes were found to be equally expressed (Fold change 1.000) in both PG and SLG mesenchyme. The numbers of genes expressed over onefold in the PG and SLG mesenchyme were found to be 5247 and 5600 respectively. On limiting the fold-change cut off value over 1.5 folds, only 214 and 137 genes were expressed over 1.5 folds in the PG and the SLG mesenchyme respectively. Our findings suggest that differential expression patterns of the mesenchymal signaling molecules are involved in fate determination of the salivary acinar cell types during mouse embryogenesis. In the near future, functional evaluation of the candidate genes will be performed using gain- and loss-of-function mutation studies during in vitro organ cultivation.

Bufalin Induces Apoptosis and Improves the Sensitivity of Human Glioma Stem-Like Cells to Temozolamide

Glioma is the most common malignant tumor of the central nervous system, and it is characterized by high relapse and fatality rates and poor prognosis. Bufalin is one of the main ingredients of Chan-su, a traditional Chinese medicine (TCM) extracted from toad venom. Previous studies revealed that bufalin exerted inhibitory effects on a variety of tumor cells. To demonstrate the inhibitory effect of bufalin on glioma cells and glioma stem-like cells (GSCs) and discuss the underlying mechanism, the proliferation of glioma cells was detected by MTT and colony formation assays following treatment with bufalin. In addition, we investigated whether bufalin inhibits or kills GSCs using flow cytometry, Western blotting, and reverse transcription polymerase chain reaction analysis (RT-PCR). Finally, we investigated whether bufalin could improve the therapeutic effect of temozolomide (TMZ) and discussed the underlying mechanism. Taken together, our data demonstrated that bufalin inhibits glioma cell growth and proliferation, inhibits GSC proliferation, and kills GSCs. Bufalin was found to induce the apoptosis of GSCs by upregulating the expression of the apoptotic proteins cleaved caspase 3 and poly(ADP-ribose) polymerase (PARP) and by downregulating the expression of human telomerase reverse transcriptase, which is a marker of telomerase activity. Bufalin also improved the inhibitory effect of TMZ on GSCs by activating the mitochondrial apoptotic pathway. These results suggest that bufalin damages GSCs, induces apoptosis, and enhances the sensitivity of GSCs to TMZ.