VIRMA promotes nasopharyngeal carcinoma, tumorigenesis, and metastasis by upregulation of E2F7 in an m6A-dependent manner.

The N6-methyladenosine (m6A) modification possesses new and essential roles in tumor initiation and progression by regulating mRNA biology. However, the role of aberrant m6A regulation in nasopharyngeal carcinoma (NPC) remains unclear. Here, through comprehensive analyses of NPC cohorts from the GEO database and our internal cohort, we identified that VIRMA, an m6A writer, is significantly upregulated in NPC and plays an essential role in tumorigenesis and metastasis of NPC, both in vitro and in vivo. High VIRMA expression served as a prognostic biomarker and was associated with poor outcomes in patients with NPC. Mechanistically, VIRMA mediated the m6A methylation of E2F7 3'-UTR, then IGF2BP2 bound, and maintained the stability of E2F7 mRNA. An integrative high-throughput sequencing approach revealed that E2F7 drives a unique transcriptome distinct from the classical E2F family in NPC, which functioned as an oncogenic transcriptional activator. E2F7 cooperated with CBFB-recruited RUNX1 in a non-canonical manner to transactivate ITGA2, ITGA5, and NTRK1, strengthening Akt signaling-induced tumor-promoting effect.

Gene expression profiling of epidermal cell types in C. elegans using Targeted DamID.

The epidermis of Caenorhabditis elegans is an essential tissue for survival because it contributes to the formation of the cuticle barrier as well as facilitating developmental progression and animal growth. Most of the epidermis consists of the hyp7 hypodermal syncytium, the nuclei of which are largely generated by the seam cells, which exhibit stem cell-like behaviour during development. How seam cell progenitors differ transcriptionally from the differentiated hypodermis is poorly understood. Here, we introduce Targeted DamID (TaDa) in C. elegans as a method for identifying genes expressed within a tissue of interest without cell isolation. We show that TaDa signal enrichment profiles can be used to identify genes transcribed in the epidermis and use this method to resolve differences in gene expression between the seam cells and the hypodermis. Finally, we predict and functionally validate new transcription and chromatin factors acting in seam cell development. These findings provide insights into cell type-specific gene expression profiles likely associated with epidermal cell fate patterning.

Integrated analysis reveals critical cisplatin-resistance regulators E2F7 contributed to tumor progression and metastasis in lung adenocarcinoma.

BACKGROUND: Drug resistance poses a significant challenge in cancer treatment, particularly as a leading cause of therapy failure. Cisplatin, the primary drug for lung adenocarcinoma (LUAD) chemotherapy, shows effective treatment outcomes. However, the development of resistance against cisplatin is a major obstacle. Therefore, identifying genes resistant to cisplatin and adopting personalized treatment could significantly improve patient outcomes. METHODS: By examining transcriptome data of cisplatin-resistant LUAD cells from the GEO database, 181 genes associated with cisplatin resistance were identified. Using univariate regression analysis, random forest and multivariate regression analyses, two prognostic genes, E2F7 and FAM83A, were identified. This study developed a prognostic model utilizing E2F7 and FAM83A as key indicators. The Cell Counting Kit 8 assay, Transwell assay, and flow cytometry were used to detect the effects of E2F7 on the proliferation, migration, invasiveness and apoptosis of A549/PC9 cells. Western blotting was used to determine the effect of E2F7 on AKT/mTOR signaling pathway. RESULTS: This study has pinpointed two crucial genes associated with cisplatin resistance, E2F7 and FAM83A, and developed a comprehensive model to assist in the diagnosis, prognosis, and evaluation of relapse risk in LUAD. Analysis revealed that patients at higher risk, according to these genetic markers, had elevated levels of immune checkpoints (PD-L1 and PD-L2). The prognostic and diagnosis values of E2F7 and FAM83A were further confirmed in clinical data. Furthermore, inhibiting E2F7 in lung cancer cells markedly reduced their proliferation, migration, invasion, and increased apoptosis. In vivo experiments corroborated these findings, showing reduced tumor growth and lung metastasis upon E2F7 suppression in lung cancer models. CONCLUSION: Our study affirms the prognostic value of a model based on two DEGs, offering a reliable method for predicting the success of tumor immunotherapy in patients with LUAD. The diagnostic and predictive model based on these genes demonstrates excellent performance. In vitro, reducing E2F7 levels shows antitumor effects by blocking LUAD growth and progression. Further investigation into the molecular mechanisms has highlighted E2F7's effect on the AKT/mTOR signaling pathway, underscoring its therapeutic potential. In the era of personalized medicine, this DEG-based model promises to guide clinical practice.

p53/E2F7 axis promotes temozolomide chemoresistance in glioblastoma multiforme.

BACKGROUND: Glioblastoma multiforme (GBM) is the most aggressive form of brain cancer, and chemoresistance poses a significant challenge to the survival and prognosis of GBM. Although numerous regulatory mechanisms that contribute to chemoresistance have been identified, many questions remain unanswered. This study aims to identify the mechanism of temozolomide (TMZ) resistance in GBM. METHODS: Bioinformatics and antibody-based protein detection were used to examine the expression of E2F7 in gliomas and its correlation with prognosis. Additionally, IC50, cell viability, colony formation, apoptosis, doxorubicin (Dox) uptake, and intracranial transplantation were used to confirm the role of E2F7 in TMZ resistance, using our established TMZ-resistance (TMZ-R) model. Western blot and ChIP experiments provided confirmation of p53-driven regulation of E2F7. RESULTS: Elevated levels of E2F7 were detected in GBM tissue and were correlated with a poor prognosis for patients. E2F7 was found to be upregulated in TMZ-R tumors, and its high levels were linked to increased chemotherapy resistance by limiting drug uptake and decreasing DNA damage. The expression of E2F7 was also found to be regulated by the activation of p53. CONCLUSIONS: The high expression of E2F7, regulated by activated p53, confers chemoresistance to GBM cells by inhibiting drug uptake and DNA damage. These findings highlight the significant connection between sustained p53 activation and GBM chemoresistance, offering the potential for new strategies to overcome this resistance.

Copper nanoparticles and silver nanoparticles impair lymphangiogenesis in zebrafish.

Lymphatic system distributes in almost all vertebrate tissues and organs, and plays important roles in the regulation of body fluid balance, lipid absorption and immune monitoring. Although CuNPs or AgNPs accumulation has been reported to be closely associated with delayed hatching and motor dysfunction in zebrafish embryos, their biological effects on lymphangiogenesis remain unknown. In this study, thoracic duct was observed to be partially absent in both CuNPs and AgNPs stressed zebrafish larvae. Specifically, CuNPs stress induced hypermethylation of E2F7/8 binding sites on CCBE1 promoters via their producing ROS, thereby leading to the reduction of binding enrichment of E2F7/8 on CCBE1 promoter and its subsequently reduced expression, then resulting in defective lymphatic vessel formation. Differently, AgNPs stress induced down-regulated CCBE1 expression via down-regulating mRNA and protein levels of E2F7/8 transcription factors, thereby resulting in defective lymphatic vessel formation. This study may be the first to demonstrate that CuNPs and AgNPs damaged lymphangiogenesis during zebrafish embryogenesis, mechanistically, CuNPs epigenetically regulated the expression of lymphangiogenesis regulator CCBE1 via hypermethylating its promoter binding sites of E2F7/8, while AgNPs via regulating E2F7/8 expression. Meanwhile, overexpression of ccbe1 mRNA effectively rescued the lymphangiogenesis defects in both AgNPs and CuNPs stressed larvae, while overexpression of e2f7/8 mRNA effectively rescued the lymphangiogenesis defects in AgNPs rather than CuNPs stressed larvae. The results in this study will shed some light on the safety assessment of nanomaterials applied in medicine and on the ecological security assessments of nanomaterials. Video Abstract.

Transcription factor E2F7 activates PKMYT1 to partially suppress adriamycin sensitivity in gastric cancer through the MAPK signaling pathway.

Background: Adriamycin resistance remains an obstacle to gastric cancer chemotherapy treatment. Objective: The objective of this study was to study the role and mechanism of transcription factor E2F7 in sensitivity to ADM chemotherapeutic agents in gastric cancer. Methods: Cell viability and cell sensitivity were assessed by CCK-8 and IC50 values of ADM were calculated. The impact of ADM on cellular proliferative capacity was assessed through colony formation assay. The binding relationship between E2F7 and PKMYT1 was then verified by dual luciferase assay and chromatin immunoprecipitation assay. ERK1/ERK2 and p-ERK1/p-ERK2 protein expression levels were detected by western blot. Results: In both gastric cancer tissue and ADM-resistant cells, a conspicuous upregulation of E2F7 and PKMYT1 was observed. Upregulated PKMYT1 was notably enriched in the MAPK signaling pathway. Enhanced levels of E2F7 were shown to not only drive gastric cancer cell proliferation but also engender a reduction in the sensitivity of these cells to ADM. Furthermore, PKMYT1 emerged as a downstream target of E2F7. Activation of E2F7 culminated in the transcriptional upregulation of PKMYT1, and silencing E2F7 reversed the inhibitory impact of PKMYT1 overexpression on ADM sensitivity in gastric cancer cells. Conclusion: E2F7/PKMYT1 axis might promote the proliferation and partially inhibit ADM sensitivity of gastric cancer cells by activating the MAPK pathway.

Natural compound So-2 suppresses triple-negative breast cancer through inducing ferroptosis via downregulating transcription factor E2F7.

Triple-negative breast cancer (TNBC), accounting for about 15∼18% of all breast cancers, is notorious for its poor prognosis, high rate of relapse and short overall survival. Because of lacking effective therapeutic targets or drugs, treatment of TNBC in clinical encounters great obstacle. Siegesbeckiaorientalis L. have been used as a traditional Chinese medicine "Xi-Xian-Cao" for centuries with multiple medicinal benefits including cancerous treatment. We have reported the isolation of twenty-seven germacranolides including So-2 from the aerial parts of S. orientalis with potent cytotoxicity against breast cancer cells. The studyaims to verified the anti-TNBC function of the natural compound So-2 both in vitro and vivo and uncover the underlying mechanism. The results showed that So-2 caused cell cycle arrest and suppress TNBC cell proliferation and migration. Also, So-2 was first identified to be a bona fide ferroptosis inducer in TNBC cells. So-2 effectively suppressed tumor growth of TNBC by using an orthotopic transplantation tumor model. We also characterized the oncogenic role of the transcription factor E2F7 in TNBC. E2F7 was demonstrated to be involved in the ferroptosis-inducing and tumor suppression effect of So-2. Altogether, So-2 exhibits inhibitory effect on TNBC both in vitro and vivo by inducing TNBC ferroptosis via downregulating the expression of E2F7. These findings provide valuable insight into the pathogenesis of TNBC. The natural compound So-2, isolated from Chinese traditional medicine, might be a prospective drug candidate in TNBC therapy.

Hsa-miR-195-5p Inhibits Autophagy and Gemcitabine Resistance of Lung Adenocarcinoma Cells via E2F7/CEP55.

Lung adenocarcinoma (LUAD) is a common malignancy. Many studies have shown that LUAD is resistant to gemcitabine chemotherapy, resulting in poor treatment outcomes in patients. We designed this study to reveal influences of hsa-miR-195-5p/E2F7/CEP55 axis on gemcitabine resistance and autophagy of LUAD cells. The expression data of LUAD-related mRNAs were downloaded from TCGA-LUAD database for differential expression analysis. The bioinformatics databases (hTFtarget, starBase and TargetScan) were used to predict the upstream and downstream regulatory molecules of E2F7. Then the binding relationships between E2F7 and regulatory molecules were verified by ChIP and dual-luciferase reporter assay. qRT-PCR and western blot were used to detect the mRNA and protein levels of has-miR-195-5p, E2F7, and CEP55. CCK-8 assay was used to analyze the half-maximal inhibitory concentration (IC50) and cell proliferation ability of LUAD cells after gemcitabine treatment. Apoptosis was detected by flow cytometry. Apoptosis/autophagy markers and LC3 aggregation were detected by western blot and immunofluorescence, respectively. Finally, the mouse transplantation model was constructed to verify the regulation mechanism in vivo. In LUAD cells and tissues, E2F7 and CEP55 were highly expressed, while has-miR-195-5p was relatively less expressed. The ChIP or dual-luciferase assays demonstrated the binding relationships of E2F7 to the CEP55 promoter region and has-miR-195-5p to the 3'-UTR of E2F7. Cell experiments demonstrated that overexpression of hsa-miR-195-5p stimulated LUAD cell apoptosis and inhibited autophagy and gemcitabine resistance, while further overexpression E2F7/CEP55 could reverse the impact by hsa-miR-195-5p overexpression. In vivo experiments identified that hsa-miR-195-5p/E2F7/CEP55 axis constrained the growth of LUAD tumor. Hsa-miR-195-5p promoted apoptosis, repressed proliferation, and autophagy via E2F7/CEP55 and reduced gemcitabine resistance in LUAD, indicating that hsa-miR-195-5p/E2F7/CEP55 may be a novel target for LUAD.

E2F family play important roles in tumorigenesis.

Tumors are serious threats to human health. The transcription factors are regarded as the potential targets for tumor treatment. As an important family of transcription factors, E2F family transcription factors (E2Fs) play vital roles in cell proliferation and regulation. However, the expression feature, gene functions, and molecular interactions of E2Fs in tumorigenesis are not clear. In this study, the transcriptome data, mutation data, and protein-protein interaction data of 10 high-incidence tumors in China from the TCGA database were integrated and analyzed to explore the expression, structure, function, mutation, and phylogenetic characteristics of E2Fs. The results showed that E2F1 and E2F7 were regularly upregulated in the tumor samples. Moreover, E2Fs participated in the regulation of the cell cycle, cell aging, and other signaling pathways. As an important regulator, E2F1 interacted with more proteins than other E2Fs. At the same time, the genetic mutation types of E2Fs varied in tumor type and patient sex, of which gene amplification accounts for the largest proportion. Phylogenetic analysis showed that E2Fs were conserved in 41 species, including fruit flies, nematodes, and humans. Meanwhile, E2Fs had a tendency for gene expansion during evolution. In conclusion, this study clarified the expression pattern, mutation characteristics, and evolutionary trend of E2Fs in high-incidence tumors in China, and suggested that E2F family transcription factors could be novel diagnostic markers for tumor diseases. Furthermore, this work can provide a theoretical basis for the development of anti-tumor-targeted drugs.

RORα contributes to the maintenance of genome ploidy in the liver of mice with diet-induced nonalcoholic steatohepatitis.

Hepatic polyploidization is closely linked to the progression of nonalcoholic fatty liver disease (NAFLD); however, the underlying molecular mechanism is not clearly understood. In this study, we demonstrated the role of retinoic acid-related orphan receptor α (RORα) in the maintenance of genomic integrity, particularly in the pathogenesis of NAFLD, using the high-fat diet (HFD)-fed liver-specific RORα knockout (RORα-LKO) mouse model. First, we observed that the loss of hepatic retinoic acid receptor-related orphan receptor α (RORα) accelerated hepatocyte nuclear polyploidization after HFD feeding. In 70% partial hepatectomy experiments, enrichment of hepatocyte polyploidy was more obvious in the RORα-LKO animals, which was accompanied by early progression to the S phase and blockade of the G2/M transition, suggesting a potential role of RORα in suppressing hepatocyte polyploidization in the regenerating liver. An analysis of a publicly available RNA sequencing (RNA-seq) and chromatin immunoprecipitation-seq dataset, together with the Search Tool of the Retrieval of Interacting Genes/Proteins database resource, revealed that DNA endoreplication was the top-enriched biological process Gene Ontology term. Furthermore, we found that E2f7 and E2f8, which encode key transcription factors for DNA endoreplication, were the downstream targets of RORα-induced transcriptional repression. Finally, we showed that the administration of JC1-40, an RORα activator (5 mg/kg body wt), significantly reduced hepatic nuclear polyploidization in the HFD-fed mice. Together, our observations suggest that the RORα-induced suppression of hepatic polyploidization may provide new insights into the pathological polyploidy of NAFLD and may contribute to the development of therapeutic strategies for the treatment of NAFLD.NEW & NOTEWORTHY It has been reported that hepatic polyploidization is closely linked to the progression of NAFLD. Here, we showed that the genetic depletion of hepatic RORα in mice accelerated hepatocyte polyploidization after high-fat diet feeding. The mechanism could be the RORα-mediated repression of E2f7 and E2f8, key transcription factors for DNA endoreplication. Thus, preservation of genome integrity by RORα could provide a new insight for developing therapeutics against the disease.

Copper stress impairs angiogenesis and lymphangiogenesis during zebrafish embryogenesis by down-regulating pERK1/2-foxm1-MMP2/9 axis and epigenetically regulating ccbe1 expression.

Molecular transport and cell circulation between tissues and organs through blood and lymphatic vessels are essential for physiological homeostasis in vertebrates. Despite the report of its association with vessel formation in solid tumors, the biological effects of Copper (Cu) accumulation on angiogenesis and lymphangiogenesis during embryogenesis are still unknown. In this study, we unveiled that intersegmental blood circulation was partially blocked in Cu2+-stressed zebrafish embryos and cell migration and tube formation were impaired in Cu2+-stressed mammalian HUVECs. Specifically, Cu2+-stressed embryos showed down-regulation in the expression of amotl2 and its downstream pERK1/2-foxm1-MMP2/9 regulatory axis, and knockdown/knockout of foxm1 in zebrafish embryos phenocopied angiogenesis defects, while FOXM1 knockdown HUVECs phenocopied cell migration and tube formation defects, indicating that excessive Cu2+-induced angiogenesis defects and blocked cell migration via down-regulating amotl2-pERK1/2-foxm1-MMP2/9 regulatory axis in both embryos and mammalian cells. Additionally, thoracic duct was revealed to be partially absent in Cu2+-stressed zebrafish embryos. Specifically, Cu2+-stressed embryos showed down-regulation in the expression of ccbe1 (a gene with pivotal function in lymphangiogenesis) due to the hypermethylation of the E2F7/8 binding sites on ccbe1 promoter to reduce their binding enrichment on the promoter, contributing to the potential mechanisms for down-regulation of ccbe1 and the formation of lymphangiogenesis defects in Cu2+-stressed embryos and mammalian cells. These integrated data demonstrate that Cu2+ stress impairs angiogenesis and lymphangiogenesis via down-regulation of pERK1/2-foxm1-MMP2/9 axis and epigenetic regulation of E2F7/8 transcriptional activity on ccbe1 expression, respectively.

E2F7 promotes mammalian target of rapamycin inhibitor resistance in hepatocellular carcinoma after liver transplantation.

The mammalian target of rapamycin (mTOR) pathway is frequently deregulated and has critical roles in cancer progression. mTOR inhibitor has been widely used in several kinds of cancers and is strongly recommended in patients with hepatocellular carcinoma (HCC) after liver transplantation (LT). However, the poor response to mTOR inhibitors due to resistance remains a challenge. Hypoxia-associated resistance limits the therapeutic efficacy of targeted drugs. The present study established models of HCC clinical samples and cell lines resistance to mTOR inhibitor sirolimus and screened out E2F7 as a candidate gene induced by hypoxia and promoting sirolimus resistance. E2F7 suppressed mTOR complex 1 via directly binding to the promoter of the TSC1 gene and stabilizes hypoxia-inducible factor-1α activating its downstream genes, which are responsible for E2F7-dependent mTOR inhibitor resistance. Clinically, low E2F7 expression could be an effective biomarker for recommending patients with HCC for anti-mTOR-based therapies after LT. Targeting E2F7 synergistically inhibited HCC growth with sirolimus in vivo. E2F7 is a promising target to reverse mTOR inhibition resistance. Collectively, our study points to a role for E2F7 in promoting mTOR inhibitor resistance in HCC and emphasizes its potential clinical significance in patients with HCC after LT.

E2F7 enhances hepatocellular carcinoma growth by preserving the SP1/SOX4/Anillin axis via repressing miRNA-383-5p transcription.

E2F family participates in most human malignancies by activating the transcription of the cell cycle-related genes. Whereas, as a specifical atypical member of this family, E2F7 was described as a repressor against its downstream genes and exerted oscillatory and controversial functions in cancers. Our previous study identified a molecular interaction promoting hepatocellular carcinoma (HCC) growth induced by SOX4 and Anillin. Meanwhile, we preliminarily identified SP1 as the upstream activator of SOX4. Intriguingly, we observed that the repressive E2F7 presents a remarkable high expression in HCC, and is positively correlated and involved in the same pathway with the potentially SP1/SOX4/Anillin axis. However, their exact interaction or mechanism controlling tumor progress between these genes has not been illustrated. Thus, we focused on this point in this study and attempted to improve the potential regulating axis in HCC cell proliferation and tumor growth for promoting tumor prevention and control. The expression profile of E2F7 in HCC tissues and tumor cells was detected along with the related candidate genes, through real-time quantitative polymerase chain reaction assay, the Western blot analysis, and the immunohistochemistry assay, combined with bioinformatics analysis of the HCC information from the the Cancer Genome Altas and Gene Expression Omnibus data sets. The correlation between E2F7 and HCC patients' clinicopathologic features was explored. Gain-of and loss-of-function assays were conducted both in vitro and in vivo along with the rescue experiment, for revealing the relative genes' functions in HCC progress. The ChIP and the dual-luciferase reporter assays were performed to verify the transcriptional regulating profile between E2F7 and SP1/SOX4/Anillin axis. E2F7 was upregulated in HCC and significantly correlated with SP1/SOX4/Anillin axis. High E2F7 expression is associated with dismal clinicopathologic features and poor survival of the patients. E2F7 depletion potently impaired SP1/SOX4/Anillin expression and significantly inhibited HCC growth. Furthermore, intensive exploration demonstrated that E2F7 preserves high SP1 levels by abrogating miR-383-5p in a transcriptional way. Atypical E2F7 is an important repressive transcription factor commonly upregulated in the HCC environment. E2F7 facilitates HCC growth by repressing miR-383-5p transcription and sequentially promoting SP1/SOX4/Anillin axis. Our findings provide us with probable targets for HCC prevention and therapeutic treatment.

Dihydroartemisinin ameliorates chronic nonbacterial prostatitis and epithelial cellular inflammation by blocking the E2F7/HIF1α pathway.

OBJECTIVE: Chronic nonbacterial prostatitis (CNP) has remained one of the most prevalent urological diseases, particularly in older men. Dihydroartemisinin (DHA) has been identified as a semi-synthetic derivative of artemisinin that exhibits broad protective effects. However, the role of DHA in inhibiting CNP inflammation and prostatic epithelial cell proliferation remains largely unknown. MATERIALS AND METHODS: CNP animal model was induced by carrageenan in C57BL/6 mouse. Enzyme linked immunosorbent assay (ELISA), Real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot were used to examine inflammatory cytokines and proliferation genes expression. Immunofluorescence and immunochemistry staining were used to detect and E2F7 expression. Human prostatic epithelial cells (HPECs) and RWPE-1 was induced by lipopolysaccharide (LPS) to mimic CNP model in vitro. Cell proliferation was determined using MTS assay. RESULTS: DHA significantly alleviated the rough epithelium and inhibited multilamellar cell formation in the prostatic gland cavity and prostatic index induced by carrageenan. In addition, DHA decreased the expression of TNF-α and IL-6 inflammatory factors in prostatitis tissues and in LPS-induced epithelial cells. Upregulation of transcription factor E2F7, which expression was inhibited by DHA, was found in CNP tissues, human BPH tissues and LPS-induced epithelial cells inflammatory response. Mechanically, we found that depletion of E2F7 by shRNA inhibited epithelial cell proliferation and LPS-induced inflammation while DHA further enhance these effects. Furthermore, HIF1α was transcriptional regulated by E2F7 and involved in E2F7-inhibited CNP and cellular inflammatory response. Interestingly, we found that inhibition of HIF1α blocks E2F7-induced cell inflammatory response but does not obstruct E2F7-promoted cell growth. CONCLUSION: The results revealed that DHA inhibits the CNP and inflammation by blocking the E2F7/HIF1α pathway. Our findings provide new evidence for the mechanism of DHA and its key role in CNP, which may provide an alternative solution for the prevention and treatment of CNP.

GBE attenuates arsenite-induced hepatotoxicity by regulating E2F1-autophagy-E2F7a pathway and restoring lysosomal activity.

Arsenic is an environmental toxicant. Its overdose can cause liver damage. Autophagy has been reported to be involved in arsenite (iAs3+ ) cytotoxicity and plays a dual role in cell proliferation and cell death. However, the effect and molecular regulative mechanisms of iAs3+ on autophagy in hepatocytes remains largely unknown. Here, we found that iAs3+ exposure lead to hepatotoxicity by inducing autophagosome and autolysosome accumulation. On the one hand, iAs3+ promoted autophagosome synthesis by inhibiting E2F1/mTOR pathway in L-02 human hepatocytes. On the other, iAs3+ blocked autophagosome degradation partially via suppressing the expression of INPP5E and Rab7 as well as impairing lysosomal activity. More importantly, autophagosome and autolysosome accumulation induced by iAs3+ increased the protein level of E2F7a, which could further inhibit cell viability and induce apoptosis of L-02 cells. The treatment of Ginkgo biloba extract (GBE) effectively reduced autophagosome and autolysosome accumulation and thus alleviated iAs3+ -induced hepatotoxicity. Moreover, GBE could also protect lysosomal activity, promote the phosphorylation level of E2F1 (Ser364 and Thr433) and Rb (Ser780) as well as suppress the protein level of E2F7a in iAs3+ -treated L-02 cells. Taken together, our data suggested that autophagosome and autophagolysosome accumulation play a critical role for iAs3+ -induced hepatotoxicity, and GBE is a promising candidate for intervening iAs3+ induced liver damage by regulating E2F1-autophagy-E2F7a pathway and restoring lysosomal activity.

miR-129-5p inhibits proliferation, migration, and invasion in rectal adenocarcinoma cells through targeting E2F7.

microRNAs (miRNAs), a kind of small noncoding RNAs, are considered able to regulate expression of genes and mediate RNA silencing. miR-129-5p was shown to be a cancer-related miRNA. However, the influence of miR-129-5p in rectal adenocarcinoma (READ) development remains to be determined. Based on the TCGA data, downregulation of miR-129-5p in READ samples was observed. Manual restoration of the miR-129-5p in SW1463 and SW480 cell lines significantly inhibited invasion, migration, and proliferation of READ cell lines, while the apoptosis ability was enhanced. Meanwhile, we found E2F7 acted as a potential target of miR-129-5p and was upregulated in READ samples. E2F7 upregulation reversed the repression of miR-129-5p on READ development. Finally, in vivo experiments showed that inhibition of tumor growth in nude mice was achieved through upregulating miR-129-5p. Overall, our findings suggest increasing of miR-129-5p leads to the suppression of READ progression through regulating the expression of E2F7, which may provide novel insights into the treatment of READ.

MiR-10b inhibits migration and invasion of pancreatic ductal adenocarcinoma via regulating E2F7.

BACKGROUND: Abnormal microRNAs (miRNAs) expression is closely related to the development and poor prognosis of pancreatic ductal adenocarcinoma (PDAC). We aimed to elucidate the invasive mechanism and clinical significance of miR-10b in PDAC. METHODS: The RNA sequence data of pancreatic cancer were extracted from the TCGA database. R packages were performed to analyze the differential expression of RNAs. TargetScan, picTar, and miRanda were used to predict the target gene of miRNA. The expression level of the selected candidate was tested by western blot and RT-PCR in PDAC cells and tissues. Scrape and Transwell assays were determined the effect of candidate molecules on cell migration and invasion. The gain of function and loss of function was achieved by co-culture with mimics and vector. Luciferase reporters were generated based on the psiCHECK2 vector. The relative luciferase activity was measured with the Dual-Luciferase Reporter Assay System and Infinate M200 PRO microplate reader. RESULTS: Based on the TCGA data and bioinformatics analysis, we obtained seven differentially expressed miRNAs. Both TCGA data and our center clinical date indicated that miR-10b was contributed to the poor survival of PDAC. Based on the target gene prediction database, we found that E2F7 was a target mRNA of miR-10b. In subsequent experiments in molecular biology, miR-10b expression was downregulated in PDAC cells and tissues, while E2F7 was upregulated. Scrape and Transwell assay indicated that miR-10b could inhibit the invasion and migration of PDAC. MiR-10b was confirmed to be by the E2F7 targeting site by dual-luciferase report. Moreover, rescue experiments prove that miR-10b could inhibit the invasion and migration of PDAC cells by regulating E2F7 expression. CONCLUSION: Our results suggest that miR-10b could inhibit the progression of PDAC by regulating E2F7 expression and acts as an independent prognostic risk factor for PDAC.

CircPRKCI-miR-545/589-E2F7 axis dysregulation mediates hydrogen peroxide-induced neuronal cell injury.

Excessive oxidative stress induces significant injury and cytotoxicity to neuronal cells. The current study tested expression and the potential function of the circular RNA PRKCI (circPRKCI) in oxidative stress-injured neuronal cells. In cultured SH-SY5Y neuronal cells, hydrogen peroxide (H2O2) downregulated circPRKCI expression, causing accumulation of miR-545 and miR-589, but reduction of their target, the transcription factor E2F7. Importantly, ectopic overexpression of circPRKCI in SH-SY5Y cells significantly attenuated H2O2-induced cytotoxicity. Conversely, siRNA-mediated knockdown of circPRKCI induced SH-SY5Y cell death and apoptosis. Further studies demonstrated that H2O2-induced cytotoxicity in SH-SY5Y cells was inhibited by miR-545/589 inhibitors, but mimicked by miR-545/589 mimics. Importantly, CRISPR/Cas9-mediated knockout (KO) of E2F7 induced potent SH-SY5Y cell death and apoptosis. Furthermore, transfection of circPRKCI siRNA or miR-545/589 mimics were ineffective in E2F7 KO cells. In the primary human neurons, H2O2 stimulation similarly induced circPRKCI downregulation, miR-545/589 accumulation and E2F7 reduction. Moreover, H2O2-induced death and apoptosis in the primary neurons were significantly inhibited by circPRKCI overexpression or miR-545/589 inhibitors. Taken together, our results show that dysregulation of circPRKCI-miR-545/589-E2F7 axis mediated H2O2-induced neuronal cell injury. Targeting this novel cascade could be a fine strategy to protect neurons from oxidative stress.

microRNA-935 is reduced in non-small cell lung cancer tissue, is linked to poor outcome, and acts on signal transduction mediator E2F7 and the AKT pathway.

BACKGROUND: A potential role for microRNA-935 (miR-935) has been identified in several cancers but not in non-small cell lung cancer (NSCLC). We hypothesised changes in miR-935 in NSCLC, and proposed mechanisms that may further explain its role in carcinogenesis. METHODS: NSCLC tissue and nearby normal tissue was obtained from 101 patients and was probed by qRT-PCR for miR-935 expression. The role of miR-935 and a potential target (signal transduction factor E2F7) was determined in cell lines by a dual luciferase assay. The function of miR-935 was investigated through metabolic activity (MTT) and transwell migration assays. Western blot and immunocytochemical assays examined protein expression level. Growth of miR-935 transfected or untransfected cells was measured via xenograft tumour formation. RESULTS: miR-935 was reduced in cancer tissue and was related to lymph node metastases, tumour node metastasis status and poor prognosis (all p < 0.02). In vitro, miR-935 suppressed cell proliferation, migration and invasion in NSCLC cells through targeting E2F7. Furthermore, E2F7 was upregulated in NSCLC tissue associated with poor prognosis (p = 0.0203) of NSCLC patients. miR-935 suppressed the epithelial-mesenchymal transition and AKT pathways in NSCLC and inhibited the tumour growth in vivo. CONCLUSION: Altered miR-935 in lung cancer biopsy tissue may be a diagnostic tool and could direct treatment. Involvement in carcinogenesis is implied by its suppression of the development of NSCLC via targeting E2F7 and inhibiting AKT pathway.