p53 exerts anticancer effects by regulating enhancer formation and activity

The abnormality of the p53 tumor suppressor is crucial in lung cancer development,because p53 regulates target gene promoters to combat cancer.Recent studies have shown extensive p53 binding to enhancer elements.However,whether p53 exerts a tumor suppressor role by shaping the enhancer landscape remains poorly understood.In the current study,we employed several functional genomics approaches to assess the enhancer activity at p53 binding sites throughout the genome based on our established TP53 knockout(KO)human bronchial epithelial cells(BEAS-2B).A total of 943 active regular enhancers and 370 super-enhancers(SEs)disappeared upon the deletion of p53,indicating that p53 modulates the activity of hundreds of enhancer elements.We found that one p53-dependent SE,located on chromosome 9 and designated as KLF4-SE,regulated the expression of the Krüppel-like factor 4(KLF4)gene.Furthermore,the deletion of p53 significantly decreased the KLF4-SE enhancer activity and the KLF4 expression,but increased colony formation ability in the nitrosamines 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone-induced cell transformation model.Subsequently,in TP53 KO cells,the overexpression of KLF4 partially reversed the increased clonogenic capacity caused by p53 deficiency.Consistently,KLF4 expression also decreased in lung cancer tissues and cell lines.It appeared that overexpression of KLF4 significantly suppressed the proliferation and migration of lung cancer cells.Collectively,our results suggest that the regulation of enhancer formation and activity by p53 is an integral component of the p53 tumor suppressor function.Therefore,our findings offer some novel insights into the regulation mechanism of p53 in lung oncogenesis and introduce a new strategy for screening therapeutic targets.

Research Progress on Application of Borneol As Permeation Enhancer in Functional Cosmetics

Borneol, as a traditional natural permeation enhancer, has been widely used to promote the transdermal absorption of active ingredients. In this review, the mechanism of borneol in promoting permeation by destroying the highly ordered lipid structure of the lipid layer and by destroying the hydrogen-bond network was described. The application of borneol in promoting the transdermal absorption of the active ingredients of traditional Chinese medicine and chemical drugs was introduced. The application of borneol as a natural ingredient added to functional cosmetics was summarized, and its effects on skin-spot treatment, acne skin care, eczema skin care, skin repair and anti-oxidation were introduced. Finally, the possible problems in the application of borneol in cosmetics were put forward, and the application prospect of borneol in the development of cosmetics was given.

Construction of retroviral vector carrying HSV tk gene under control of human AFP enhancer core sequence and human pgk promotor *

AIM Tenstruct retroviral vector bringing HSV tk gene under control by human AFP enhancer core sequence and human pgk promotor.

The Effects of Some Penetration Enhancers on the Transdermal Iontophoretic Delivery of Insulin in Vitro *

The effects of some commonly used penetration enhancers such as laurocapram (AZ), oleic acid (OA), poloxamer (POL) and propylene glycol (PG) on the in vitro transdermal iontophoretic delivery of insulin through full-thickness mouse skin were investigated. The results showed that AZ had a synergistic effect on iontophoretic ability to enhance skin permeation of insulin, and PG could further increase this effect. 5% AZ / PG increased the iontophoretic steady state flux of insulin by a factor of 2.75 compared to that treated with iontophoresis alone. OA did not further enhance iontophoretic effect to increase skin permeation of insulin. The combination of iontophoresis and some enhancer provided a novel idea and possibility for transdermal delivery of insulin.

Enhancer and super-enhancer: Positive regulators in gene transcription

Enhancer is a positive regulator for spatiotemporal development in eukaryotes. As a cluster, super-enhancer is closely related to cell identity- and fate-determined processes. Both of them function tightly depending on their targeted transcription factors, cofactors, and genes through distal genomic interactions. They have been recognized as critical components and played positive roles in transcriptional regulatory network or factory. Recent advances of next-generation sequencing have dramatically expanded our ability and knowledge to interrogate the molecular mechanism of enhancer and super-enhancer for transcription. Here, we review the history, importance, advances and challenges on enhancer and super-enhancer field.This will benefit our understanding of their function mechanism for transcription underlying precise gene expression.

Lubricant Biodegradation Enhancers: Designed Chemistry and Engineered Technology

In recent decades, a growing worldwide trend of developing the biodegradable lubricants has been prevailing to form a specific field of green chemistry and green engineering. Enhancement of biodegradability of unreadily biodegradable petroleum-based lubricants has as such become an urgent must. For over a decade the authors have been focusing on the improvement of biodegradability of unreadily biodegradable lubricants such as petroleum-based lubricating oils and greases. A new idea of lubricant biodegradation enhancer was put forward by the authors with the aim to stimulate the biodegradation of unreadily biodegradable lubricants by incorporating the enhancer into the lubricants in order to turn the lubricants into greener biodegradable ones and to help in situ bioremediation of lubricant-contaminated environment. This manuscript summarizes our recent efforts relating to the chemistry and technology of biodegradation enhancers for lubricants. Firstly, the chemistry of lubricant biodegradation enhancers was designed based on the principles of bioremediation for the treatment of hydrocarbon contaminated environment. Secondly, the ability of the designed biodegradation enhancers for increasing the biodegradability of unreadily biodegradable industrial lubricants was investigated through biodegradability evaluation tests, microbial population analysis, and biodegradation kinetics modeling. Finally, the impact of biodegradation enhancers on some crucial performance characteristics of lubricants such as lubricity and oxidation stability was tested via tribological evaluation and oxidation determinations. Our results have shown that the designed chemistry of nitrogenous and/or phosphorous compounds such as lauroyl glutamine, oleoyl glycine, oleic diethanolamide phosphate and lauric diethanolamide borate was outstanding in boosting biodegradation of petroleum-based lubricants which was ascribed to increase the microbial population and decrease the oil-water interfacial tension during the biodegradation process. Lubricants doped with the biodegradation enhancers exhibited much better biodegradability and higher biodegradation rate in the surrounding soils which could be well modeled by the exponential biodegradation kinetics. Furthermore, as lubricant dopants, the biodegradation enhancers also provided excellent capability in reducing friction and wear and in retarding oxidation of lubricants. In the nature of things, lubricant biodegradation enhancers, which are multi-functional not only in the improvement of biodegradability, but also in the fortification of lubricity and in the inhibition of oxidation of lubricants, are expected to be promising as a new category of lubricant additives.

Characterization of enhancer trap and gene trap harboring Ac／Ds transposon in transgenic rice

Insertion mutagenesis has become one of the most popular methods for gene functions analysis.Here we report a two-element Ac/Ds transposon system containing enhancer trap and gene trap for gene tagging in rice.The excision of Ds element was examined by PCR amplification.The excision frequency of Ds element varied from 0% to 40% among 20 F2 populations derived from 11 different Ds parents.Southern blot analysis revealed that more than 70% of excised Ds elements reinserted into rice genome and above 70% of the reinserted Ds elements were located at different positions of the chromosome in rice.The result of histochemical GUS analysis indicated that 28% of enhancer trap and 22% of gene trap tagging plants displayed GUS activity in leaves, roots,flowers or seeds.The GUS positive lines will be useful for identifying gene function in rice.

Super enhancer inhibitors suppress MYC driven transcriptional amplification and tumor progression in osteosarcoma

Osteosarcoma is the most common primary bone sarcoma that mostly occurs in young adults. The causes of osteosarcoma are heterogeneous and still not fully understood. Identification of novel, important oncogenic factors in osteosarcoma and development of better, effective therapeutic approaches are in urgent need for better treatment of osteosarcoma patients. In this study, we uncovered that the oncogene MYC is significantly upregulated in metastastic osteosarcoma samples. In addition, high MYC expression is associated with poor survival of osteosarcoma patients. Analysis of MYC targets in osteosarcoma revealed that most of the osteosarcoma super enhancer genes are bound by MYC. Treatment of osteosarcoma cells with super enhancer inhibitors THZ1 and JQ1 effectively suppresses the proliferation, migration, and invasion of osteosarcoma cells. Mechanistically,THZ1 treatment suppresses a large group of super enhancer containing MYC target genes including CDK6 and TGFB2. These findings revealed that the MYC-driven super enhancer signaling is crucial for the osteosarcoma tumorigenesis and targeting the MYC/super enhancer axis represents as a promising therapeutic strategy for treatment of osteosarcoma patients.

Genome-wide identification of functional enhancers and their potential roles in pig breeding

Background:The pig is an economically important livestock species and is a widely applied large animal model in medical research.Enhancers are critical regulatory elements that have fundamental functions in evolution,development and disease.Genome-wide quantification of functional enhancers in the pig is needed.Results:We performed self-transcribing active regulatory region sequencing(STARR-seq)in the porcine kidney epithelial PK15 and testicular ST cell lines,and reliably identified 2576 functional enhancers.Most of these enhancers were located in repetitive sequences and were enriched within silent and lowly expressed genes.Enhancers poorly overlapped with chromatin accessibility regions and were highly enriched in chromatin with the repressive histone modification H3K9me3,which is different from predicted pig enhancers detected using ChIP-seq for H3K27ac or/and H3K4me1 modified histones.This suggests that most pig enhancers identified with STARR-seq are endogenously repressed at the chromatin level and may function during cell type-specific development or at specific developmental stages.Additionally,the PPP3CA gene is associated with the loin muscle area trait and the QKI gene is associated with alkaline phosphatase activity that may be regulated by distal functional enhancers.Conclusions:In summary,we generated the first functional enhancer map in PK15 and ST cells for the pig genome and highlight its potential roles in pig breeding.

Novel chemical permeation enhancers for transdermal drug delivery

Transdermal drug delivery has been accepted as a potential non-invasive route of drug administration,with advantages of prolonged therapeutic action,decreased side effect,easy use and better patient compliance.However,development of transdermal products is primarily hindered by the low permeability of the skin.To overcome this barrier effect,numerous new chemicals have been synthesized as potential permeation enhancers for transdermal drug delivery.In this review,we presented an overview of the investigations in this field,and further implications on selection or design of suitable permeation enhancers for transdermal drug delivery were also discussed.

Effects of CMV Enhancer on Activity and Specificity of Bovine MyoG Gene Promoter

Connected a segment of CMV enhancer to the front of MyoG gene promoter and then constructed the corresponding dual luciferase expression vector pGL3-CMV-MyoGpro. We set four eukaryotic expression vectors including pGL3-CMV, pGL3MyoGpro, pGL3-CMV-MyoGpro, and pGL3-Basic which contained CMV promoter, MyoG promoter, CMV-MyoG synthesis promoter, and a promoterless negative control, respectively. Then the four vectors and internal control Renilla luciferase report gene vector phRL-TK were transfected into bovine skeletal muscle satellite cells, mouse C2C12 cells and bovine fetal fibroblast cells to detect the promoter activity with dual luciferase report system. The results showed that CMV enhancer could significantly improve the transcription activity of bovine MyoG gene promoter in muscle satellite cells and mouse C2C12 cells, and it had certain specificity. This study provided experimental materials for increasing the high expression of exogenous gene in bovine muscle cells, and also laid the molecular theoretical basis for obtaining the high specific promoter of bovine muscle and the transgenic beef cattle.

Protein hairy enhancer of split-1 expression during differentiation of muscle-derived stem cells into neuron-like cells

Muscle-derived stem cells were isolated from the skeletal muscle of Sprague-Dawley neonatal rats aged 3 days old. Cells at passage 5 were incubated in Dulbecco＇s modified Eagle＇s medium supplemented with 10% （v/v） fetal bovine serum, 20 IJg/L nerve growth factor, 20 pg/L basic fibroblast growth factor and 1% （v/v） penicillin for 6 days. Cells presented with long processes, similar to nerve cells. Connections were formed between cell processes. Immunocytochemical staining with neuron specific enolase verified that cells differentiated into neuron-like cells. Immunofluorescence cytochemistry and western blot results revealed that the expression of protein hairy enhancer of split-1 was significantly reduced. These results indicate that low expression of protein hairy enhancer of split-1 participates in the differentiation of muscle-derived stem cells into neuron-like cells.

Genotype-dependent activation or repression of HBV enhancer Ⅱ by transcription factor COUP-TF1

AIM: To study the expression of HBV enhancer Ⅱ by transcription factor COUP-TF1. METHODS: In order to study the regulation of HBV variants in the vicinity of the NRRE we cloned luciferase constructs containing the HBV enhancer Ⅱ from variants and from HBV genotypes A and D and cotransfected them together with expression vectors for COUP-TF1 into HepG2 cells. RESULTS: Our fi ndings show that enhancer Ⅱ of HBV genotype A is also repressed by COUP-TF1. In contrast, two different enhancer Ⅱ constructs of HBV genotype D were activated by COUP-TF1. The activation was independent of the NRRE because a natural variant with a deletion of nt 1763-1770 was still activated by COUP- TF1. CONCLUSION: Regulation of transcription of the HBV genome seems to differ among HBV genomes derived from different genotypes. These differences in transcriptional control among HBV genotypes may be the molecular basis for differences in the clinical course among HBV genotypes.

IMPROVE OPTICAL CLEARING OF SKIN IN VITRO WITH PROPYLENE GLYCOL AS A PENETRATION ENHANCER

In order to enhance the optical clearing effect of topically applied optical clearing agents(OCAs),we evaluated the effect of propylene glycol(PG)as a chemical penetration enhancer(PE)on optical clearing of skin in vitro by observation and measurement of optical-transmittance and diffuse-reflectance spectra.Three OCAs,i.e.,glycerol,D-sorbitol and PEG400,and two other penetration enhancers,Azone and Thiazone,were used in this study.The results indicated that the decrease of reduced scattering coefficient caused by OCA/PG was larger than that by pure OCA,and the change by OCA/water was the least after the same treatment time.There were significant differences for the reduced scattering coefficient at 630 nm after 120 min application of agents between OCA and OCA/PG.The efficacy of optical clearing caused by OCA/PG depended on the OCA itself.When PEG400 was mixed with three different PEs,we found the optical clearing were different.The penetration enhancing ability of PG was much better compared to Azone,and suboptimal to Thiazone.Also,this study provides evidence for the use of PG as a PE in order to improve skin optical clearing.

Targeting Enhancer of Zeste Homolog 2 as a promising strategy for cancer treatment

Polycomb group proteins represent a global silencing system involved in development regulation.In specific,they regulate the transition from proliferation to differentiation,contributing to stem-cell maintenance and inhibiting an inappropriate activation of differentiation programs.Enhancer of Zeste Homolog 2(EZH2) is the catalytic subunit of Polycomb repressive complex 2,which induces transcriptional inhibition through the tri-methylation of histone H3,an epigenetic change associated with gene silencing.EZH2 expression is high in precursor cells while its level decreases in differentiated cells.EZH2 is upregulated in various cancers with high levels associated with metastatic cancer and poor prognosis.Indeed,aberrant expression of EZH2 causes the inhibition of several tumor suppressors and differentiation genes,resulting in an uncontrolled proliferation and tumor formation.This editorial explores the role of Polycomb repressive complex 2 in cancer,focusing in particular on EZH2.The canonical function of EZH2 in gene silencing,the non-canonical activities as the methylation of other proteins and the role in gene transcriptional activation,were summarized.Moreover,mutations of EZH2,responsible for an increased methyltransferase activity in cancer,were recapitulated.Finally,various drugs able to inhibit EZH2 with different mechanism were described,specifically underscoring the effects in several cancers,in order to clarify the role of EZH2 and understand if EZH2 blockade could be a new strategy for developing specific therapies or a way to increase sensitivity of cancer cells to standard therapies.

VARIATION ANALYSIS OF HPV16 CELL-TYPE-SPECIFIC ENHANCER IN CERVICAL CARCINOMA

Objective To investigate the cell-type-specific enhancer (CTSE) in HPV16 and its variation in cervical carcinoma. Methods CTSEs were detected by polymerase chain reaction (PCR) in 58 cervical carcinoma from Shaanxi province; in addition variation of CTSEs was analyzed through single-strand conformation polymorphisms (SSCP). Results HPV16 CTSEs were detectable in 34 of 58 (57%) specimens and mutant rate was 41%(14/34) and the main mutations of chosen randomly variant CTSE (CTSEv) happened at YY1 binding sites in addition to glucocoticoid response elements (GRE). Conclusion CTSE in some specimens of Shaanxi province was obviously different from that in HPV16 wild type and variant CTSE might affect the transcriptional regulation of LCR on viral P97, which regulates over-expression of viral oncogenes in cervical carcinoma.

Lithium:from mood stabilizer to putative cognitive enhancer

The monovalent cation lithium,whose introduction in psychiatry dates back at the end of the 1940s,remains the first-line agent in the management of patients with bipolar disorder（BD）.It is effective in the treatment of moderate-to-severe acute mania,prophylactic for recurrent manic and depressive episodes,and reduces the risk of suicide.

Influence of chemical penetration enhancers on skin permeability of ellagic acid-loaded niosomes

This study aimed to develop niosomes of ellagic acid(EA),a potent antioxidant phytochemical substance,for dermal delivery and to investigate the influence of chemical penetration enhancers on the physicochemical properties of EA-loaded niosomes.The EA niosomes were prepared by reverse phase evaporation method using Span 60,Tween 60 and cholesterol as vesicle forming agents and Solulan C24 as a steric stabilizer.Polyethylene glycol 400(PEG)was used as a solubilizer while dimethylsulfoxide(DMSO)or Nmethyl-2-pyrrolidone(NMP)was used as a skin penetration enhancer.It was found that the mean particle sizes of EA-loaded niosomes were in the range of 312e402 nm with PI values of lower than 0.4.The niosomes were determined to be spherical multilamellar vesicles as observed by transmission electron microscope and optical microscopy.All niosomes were stable after 4 months storage at 4
C.In vitro skin permeation through human epidermis revealed that the skin enhancers affected the penetration of EA from the niosomes at 24 h.The DMSO niosomes showed the highest EA amount in epidermis;whereas the NMP niosomes had the highest EA amount in the acceptor medium.Concomitantly,the skin distribution by confocal laser scanning microscopy showed the high fluorescence intensity of the DMSO niosomes and NMP niosomes at a penetration depth of between 30e90 mm(the epidermis layer)and 90e120 mm(the dermis layer)under the skin,respectively.From the results,it can be concluded that the DMSO niosomes are suitable for epidermis delivery of EA while the NMP niosomes can be used for dermis delivery of EA.

Enhancer of zeste homolog 2 contributes to apoptosis by inactivating janus kinase 2/signal transducer and activator of transcription signaling in inflammatory bowel disease

BACKGROUND Inflammatory bowel disease(IBD)is a prevalent worldwide health problem featured by relapsing,chronic gastrointestinal inflammation.Enhancer of zeste homolog 2(EZH2)is a critical epigenetic regulator in different pathological models,such as cancer and inflammation.However,the role of EZH2 in the IBD development is still obscure.AIM To explore the effect of EZH2 on IBD progression and the underlying mechanism.METHODS The IBD mouse model was conducted by adding dextran sodium sulfate(DSS),and the effect of EZH2 on DSS-induced colitis was assessed in the model.The function of EZH2 in regulating apoptosis and permeability was evaluated by Annexin V-FITC Apoptosis Detection Kit,transepithelial electrical resistance analysis,and Western blot analysis of related markers,including Zona occludens 1,claudin-5,and occludin,in NCM460 and fetal human colon(FHC)cells.The mechanical investigation was performed by quantitative reverse transcriptionpolymerase chain reaction,Western blot analysis,and chromatin immunoprecipitation assays.RESULTS The colon length was inhibited in the DSS-treated mice and was enhanced by the EZH2 depletion in the system.DSS treatment caused a decreased histological score in the mice,which was reversed by EZH2 depletion.The inflammatory cytokines,such as tumor necrosis factor-α,interleukin-6,and interleukin-1β,were induced in the DSS-treated mice,in which the depletion of EZH2 could reverse this effect.Moreover,the tumor necrosis factor-αtreatment induced the apoptosis of NCM460 and FHC cells,in which EZH2 depletion could reverse this effect in the cells.Moreover,the depletion of EZH2 attenuated permeability of colonic epithelial cells.Mechanically,the depletion of EZH2 or EZH2 inhibitor GSK343 was able to enhance the expression and the phosphorylation of janus kinase 2(JK2)and signal transducer and activator of transcription in the NCM460 and FHC cells.Specifically,EZH2 inactivated JAK2 expression by regulating histone H3K27me3.JAK2 inhibitor TG101348 was able to reverse EZH2 knockdownmediated colonic epithelial cell permeability and apoptosis.CONCLUSION Thus,we concluded that EZH2 contributed to apoptosis and inflammatory response by inactivating JAK2/signal transducer and activator of transcription signaling in IBD.EZH2 may be applied as a potential target for IBD therapy.

Procollagen C-proteinase enhancer 1 promotes physiologic retinal angiogenesis via regulating the process of collagen

AIM:To investigate the role of procollagen C-proteinase enhancer 1(PCPE1)in retinal angiogenesis and relevant mechanisms.METHODS:The Pcolce1-knockout(KO)mice were used to explore the effect of PCPE1 on retinal angiogenesis in vivo.Pcolce1 si RNA were designed,cell count kit 8(CCK8)assays and tube formation assays were performed to investigate the cell proliferation and tube formation abilities of retinal microvascular endothelial cells(h RMECs)in vitro.Mouse embryo fibroblasts(MEF)cells were isolated and cultured to analyze the effect of PCPE1 on enhancing procollagen cleavage.RESULTS:In vivo studies showed that the retinal vascular density of Pcolce1-/-mice was significantly lower than that of the control group.Furthermore,silencing of Pcolce1 inhibited cell proliferation and tube formation abilities of h RMECs in vitro.Additionally,much more procollagen was found in Pcolce1-/-MEF cells,compared to wild type MEF cells.CONCLUSION:PCPE1 may promote physiological retinal angiogenesis by regulating the processing of collagen,which may provide a potential therapeutic target of retinal vascular disease.