Gene Expression and Regulation of Blastocyst Formation

Blastocyst formation is a crucial stage of early embryo development.Cell junction proteins and cell adhesion associated proteins are involved in the establishment of cell junction,and subsequently induce cell compaction,blastocyst formation,differentiation of trophectoderm and maintenance of blastocyst expansion.Genes regulating development and differentiation participate in embryo development and differentiation of inner cell mass and trophectoderm,which controls the transition from the undifferentiation to differentiation state.Furthermore,cytokine and growth factor have influence on the proliferation of cells of inner cell mass.In a word,many proteins and factors are involved in the gene expression and regulation of blastocyst formation.

Genetic engineering and lignin biosynthetic regulation in forest tree species

Genetic engineering of forest tree species is regarded as a strategy to reduce worldwide pressure on natural forests, to conserve genetic resources and ameliorate stress on global climate, and to meet growing demand for forest wood and timber products. Genetic engineering approaches toward the control or management of fungal pathogens, arthropod herbivores, bacterial and viral diseases, the use of pest resistance genes, and weed competitors are being studied. Although the production of transgenic trees is relatively recent and only a few species have been successfully genetically engineered in forest tree species, very useful and valuable information is available on the application of transgenic trees. Genes involved in important agricultural traits such as herbicide resistance, insect resistance, and wood quality have been isolated and have been used to genetically engineer trees. New technologies of plant molecular biology and genomics now make it possible high-efficient genetic improvement of forest trees. Genetic engineering promises to expand greatly the potential for genetic manipulation as new genes of commercial interest are discovered and utilized. Lignification is a process essential to the nature and evolution of vascular plants that is still poorly understood, even though it has been studied for more than a century. Recent studies on mutant and transgenic plants indicate that lignification may be far more flexible than previously realized. Rines with a mutation affecting the biosynthesis of the major lignin precursor, coniferyl alcohol, show a high level of an unusual subunit, dihydroconiferyl alcohol. It is also unusual as a plant polymer in that there are no plant enzymes for its degradation. These results have significant implications regarding the tradiational definition of lignin, and highlight the need for a better understanding of the lignin precursor biosynthetic pathway. In this review, we describe the progress made recently in genetic engineering of forest tree species.

Long Non-coding RNA ANRIL in Gene Regulation and Its Duality in Atherosclerosis

The antisense transcript long non-coding RNA（lnc RNA）（antisense non-coding RNA in the INK4 locus, ANRIL） is an antisense of the cyclin-dependent kinase inhibitor 2 B（CDKN2B） gene on chromosome 9 p21 that contains an overlapping 299-bp region and shares a bidirectional promoter with alternate open reading frame（ARF）. In the context of gene regulation, ANRIL is responsible for directly recruiting polycomb group（Pc G） proteins, including polycomb repressive complex-1（PRC-1） and polycomb repressive complex-2（PRC-2）, to modify the epigenetic chromatin state and subsequently inhibit gene expression in cis-regulation. On the other hand, previous reports have indicated that ANRIL is capable of binding to a specific site or sequence, including the Alu element, E2 F transcription factor 1（E2F1）, and CCCTC-binding factor（CTCF）, to achieve trans-regulation functions. In addition to its function in cell proliferation, adhesion and apoptosis, ANRIL is very closely associated with atherosclerosis-related diseases. The different transcripts and the SNPs that are related to atherosclerotic vascular diseases（ASVD-SNPs） are inextricably linked to the development and progression of atherosclerosis. Linear transcripts have been shown to be a risk factor for atherosclerosis, whereas circular transcripts are protective against atherosclerosis. Furthermore, ANRIL also acts as a component of the inflammatory pathway involved in the regulation of inflammation, which is considered to be one of the causes of atherosclerosis. Collectively, ANRIL plays an important role in the formation of atherosclerosis, and the artificial modification of ANRIL transcripts should be considered following the development of this disease.

Regulation of HIF-1 α to Expression of N-myc Downstream Regulated Gene 1 in Colorectal Carcinoma

Plasmid expressing small interfering RNA （siRNA） against HIF-1α （pSilence-2.1-U6-siRNA） was constructed and transfected into LS174T cells in hypoxia condition.After expression of siRNA against HIF-1 α in LS174T cells, expressions of HIF-1 α and N-myc downstream regulated gene 1 （NDRG1） gene were inhibited significantly. HIF-1 cta transcripts were positive in 67.7% （42/62） and 44.4% （8/18） of colorectal adenocarcinoma and adenoma, re- spectively. The mean percentage of cells with positive hybridization of HIF-1 α mRNA increases with the development from Duke stage A to stage C＋D （p〈 0.05）. The positive staining rate of NDRG1 protein was significant higher in than that in colorectal adenoma colorectal adenocarcinoma group group （p〈 0.05）. The level of HIF-1 a transcripts was positively correlated with the level of NDRG1 protein （p 〈 0.05） during colorectal tumor progression. HIF-1α and its down stream gene NDRG1 may play roles in tumor progression of human colorectal carcinoma.

Use of Rich BHI Medium Instead of Synthetic TMH Medium for Gene Regulation Study in Yersinia pestis

Objective This study is to verify the use of rich BHI medium to substitute synthetic media for gene regulation studies in Yersinia pestis. Methods The transcriptional regulation of rovA by PhoP or via temperature upshift, and that of pla by CRP were investigated when Y. pestis was cultured in BHI. After cultivation under 26 ~C, and with temperature shifting from 26 to 37 ~C, the wild-type （WT） strain or its phoP or crp null mutant （AphoP or Acrp, respectively） was subject to RNA isolation, and then the promoter activity of rovA or plo in the above strains was detected by the primer extension assay. The rovA promoter-proximal region was cloned into the pRW50 containing a promoterless lacZ gene. The recombinant LacZ reporter plasmid was transformed into WT and AphoP to measure the promoter activity of rovA in these two strains with the ^-Galactosidase enzyme assay system. Results When Y. pestis was cultured in BHI, the transcription of rovA was inhibited by PhoP and upon temperature upshift while that ofpla was stimulated by CRP. Conclusion The rich BHI medium without the need for modification to be introduced into the relevant stimulating conditions （which are essential to triggering relevant gene regulatory cascades）, can be used in lieu of synthetic TMH media to cultivate Y. pestis for gene regulation studies.

Direct somatic embryogenesis and related gene expression networks in leaf explants of Hippeastrum ‘Bangkok Rose’

Hippeastrum, a highly diverse genus in the Amaryllidaceae family, is a valuable ornamental bulbous flowering plant. Somatic embryogenesis(SE) is an efficient method for mass production of Hippeastrum plantlets. Previous studies have been devoted to the in vitro propagation of Hippeastrum, but the SE and its regulatory networks are rarely reported. In this study, we established a direct SE method of Hippeastrum Bangkok Rose' using leaf bases as explants. MS supplemented with 1.00 mg·L^(-1)NAA +1.00 mg·L^(-1)KT + 0.25 mg·L^(-1)TDZ was the optimal medium for SE. Histological observations showed that the bipolar somatic embryo originated from the epidermal cell layer and underwent initiation,globular, scutellar and coleoptile stages. During SE, endogenous hormones of IAA, CTK, ABA, and SA were highly accumulated. Transcriptomic analysis revealed the genes encoding auxin biosynthesis/metabolic enzymes and efflux carriers were induced, while the auxin receptor of TIR1 and ARF transcriptional repressor of Aux/IAA were down-regulated and up-regulated, respectively, leading to suppression of auxin signaling. In contrast, cytokine signaling was promoted at the early stage of SE, as biosynthesis, transport, and signaling components were up-regulated.Various stress-related genes were up-regulated at the early or late stages of SE. Chromatin remodeling could also be dynamically regulated via distinct expression enzymes that control histone methylation and acetylation during SE. Moreover, key SE regulators, including WOXs and SERKs were highly expressed along with SE. Overall, the present study provides insights into the SE regulatory mechanisms of the Hippeastrum.

Regulatory genes controlling neural stem cells differentiation into neurons

The recent progress in neural stem cells （NSCs） research has shed lights on possibility of repair and restoration of neuronal function in neurodegenerative diseases using stem cells. Induction of stem cells differentiate into mature neurons is critical to achieve the clinical applications of NSCs. At present, molecular mechanisms modulating NSC differentiation are not fully understood. Differentiation of stem cells into neuronal and glial cells involves an array of changes in expression of transcription factors. Transcription factors then trigger the expression of a variety of central nervous system （CNS） genes that lead NSCs to differentiate towards different cell types. In this paper, we summarized the recent findings on the gene regulation of NSCs differentiation into neuronal cells.

Regulation of cytokine signaling pathways by PIAS proteins

Cytokines activate multiple signal transduction pathways to regulate gene expression. STATs and NF-kB are two important families of transcription factors activated by cytokines. Abnormal regulation of STAT and NF-kB activities has been associated with human diseases. The protein inhibitor of activated STAT （PIAS） protein family has been proposed to interact with over 60 proteins, many of which are transcription factors involved in the immune system. PIAS proteins regulate transcription through several mechanisms, including blocking the DNA-binding activity of transcription factors, recruiting transcriptional co-repressors and promoting protein sumoylation. This article is to review the role of PIAS proteins in the regulation of STAT and NF-kB signaling pathways.

Expression and regulation of IL-22 in the IL-17.producing CD4+T lymphocytes

IL-22 is a novel cytokine in the IL-10 family that functions to promote innate immunity of tissues against infection. Although CD4＋ helper T lymphocytes （TH） were found as a source of IL-22, the regulation of this cytokine has been poorly understood. Here, we show that IL-22 is expressed at both mRNA and protein levels by a novel subset of TH cells that also makes IL-17. IL-22 and IL-17 were found to be coordinately regulated by TGFI3 and IL-6 during TH differentiation by real-time PCR as well as ELISA analysis. However, IL-22 does not regulate TH differentiation; exogenous IL-22 or an IL-22 antagonist had no effect on TH differentiation. These data demonstrate a novel cytokine expressed by IL-17-producing T cells, and suggest interaction and synergy of IL-22 and IL-l 7 signaling pathways in tissue inflammation and autoimmune diseases.

Circular RNAs in colorectal cancer:Possible roles in regulation of cancer cells

Colorectal cancer(CRC) is the third most commonly diagnosed cancer in the world and the fourth principal cause of cancer deaths worldwide. Currently, there is a lack of low cost and noninvasive screening tests for CRC, becoming a serious health problem. In this context, a potential biomarker for the early detection of CRC has recently gained attention. Circular RNAs(circ RNA), a re-discovered, abundant RNA specie, is a type of noncoding covalent closed RNAs formed from both exonic and intronic sequences. These circular molecules are widely expressed in cells, exceeding the abundance of the traditional linear m RNA transcript. They can regulate gene expression, acting as real sponges for mi RNAs and also regulate alternative splicing or act as transcriptional factors and inclusive encoding for proteins. However, little is known about circ RNA and its relationship with CRC. In this review, we focus on the biogenesis, function and role of these circ RNAs in relation to CRC, including their potential as a new biomarker.

Regulation of epithelium-specific Ets-like factors ESE-1 and ESE-3 in airway epithelial cells： potential roles in airway inflammation

Airway inflammation is the hallmark of many respiratory disorders, such as asthma and cystic fibrosis. Changes in airway gene expression triggered by inflammation play a key role in the pathogenesis of these diseases. Genetic linkage studies suggest that ESE-2 and ESE-3, which encode epithelium-specific Ets-domain-containing transcription factors, are candidate asthma susceptibility genes. We report here that the expression of another member of the Ets family transcription factors ESE-1, as well as ESE-3, is upregulated by the inflammatory cytokines interleukin-1β （IL-1β） and tumor necrosis factor-α （TNF-α） in bronchial epithelial cell lines. Treatment of these cells with IL-1β and TNF-α resulted in a dramatic increase in mRNA expression for both ESE-1 and ESE-3. We demonstrate that the induced expression is mediated by activation of the transcription factor NF-κB. We have characterized the ESE-1 and ESE-3 promoters and have identified the NF-κB binding sequences that are required for the cytokine-induced expression. In addition, we also demonstrate that ESE-1 upregulates ESE-3 expression and downregulates its own induction by cytokines. Finally, we have shown that in E/f3 （homologous to human ESE-1） knockout mice, the expression of the inflammatory cytokine interleukin-6 （IL-6） is downregulated. Our findings suggest that ESE-1 and ESE-3 play an important role in airway inflammation.

Regulated Gene Expression with Promoters Responding to Inducers

Genetically engineered transgenic animals and plants have proven to be extremely useful for analyzing biochemical and developmental processes.Promoters responding to chemical inducers will be powerful tools for basic research in molecular biology and biotechnological applications.Various chemical inducible systems based on activation and inactivation of the target gene had been described.The transfer of regulatory elements from prokaryotes,insects,and mammals has opened new avenues to construct chemically inducible promoters that differ in their ability to regulate the temporal and spatial expression patterns,and this will dramatically increase the application of transgenic technology.This review provides an overview on regulation of gene expression,promoter activating systems,promoter inactivation systems,inducible gene over expression,and inducible anti suppression.

Differentially expressed genes in hepatocellular carcinoma induced by woodchuck hepatitis B virus in mice

INTRODUCTIONHepatocellular carcinoma(HCC)is one of the major causes of death in the word.The mechanism of carcinogenesis is unknown,although it is widely accepted that HBV and HCV are clsely related to liver cancer[1-5[1-5].Previously,a variety of studies have described the differences in gene expression which distinguished tumor from nontumor[6-11].Cloning of the genes,especially the genes associated with HBV and HCV,is still very important to account for the development of liver cancer.

Molecular aspects of carcinogenesis in pancreatic cancer

BACKGROUND:Pancreatic cancer(PCa)is one of the most aggressive human solid tumors,with rapid growth and metastatic spread as well as resistance to chemotherapeutic drugs,leading rapidly to virtually incurable disease.Over the last 20 years,however,significant advances have been made in our understanding of the molecular biology of PCa,with a focus on the cytogenetic abnormalities in PCa cell growth and differentiation. DATA SOURCES:A MEDLINE search and manual cross- referencing were utilized to identify published data for PCa molecular biology studies between 1986 and 2008, with emphasis on genetic alterations and developmental oncology. RESULTS:Activation of oncogenes,deregulation of tumor suppressor and genome maintenance genes,upregulation of growth factors/growth factor receptor signaling cascade systems,and alterations in cytokine expression,have been reported to play important roles in the process of pancreatic carcinogenesis.Alterations in the K-ras proto- oncogene and the p16INK4a,p53,FHIT,and DPC4 tumor suppressor genes occur in a high percentage of tumors. Furthermore,a variety of growth factors are expressed at increased levels.In addition,PCa often exhibits alterations in growth inhibitory pathways and evades apoptosis through p53 mutations and aberrant expression of apoptosis-regulating genes,such as members of the Bcl family.Additional pathways in the development of an aggressive phenotype,local infiltration and metastasis are still under ongoing genetic research.The present paper reviews recent studies on the pathogenesis of PCa,and includes a brief reference to alterations reported for other types of pancreatic tumor. CONCLUSIONS:Advances in molecular genetics and biology have improved our perception of the pathogenesis of PCa.However,further studies are needed to better understand the fundamental changes that occur in PCa,thus leading to better diagnostic and therapeutic management.

Alterations in metastatic properties of hepatocellular carcinoma cell following H-ras oncogene transfection

AIM: To demonstrate the relationship between H-ras oncogene and hepatocellular carcinoma (HCC) metastasis. METHODS: Activated H-ras oncogene was transfected into SMMC 7721, a cell line derived from human HCC, by calcium phosphate transfection method. Some metastasis-related parameters were detected in vitro, including adhesion assay, migration assay, expression of collagenase IV(c IV ase) and epidermal growth factor receptor (EGFR). RESULTS: The abilities of H-ras-transfected cell clones in adhesion to laminin (LN) or fibronectin (FN), migration, c IV ase secretion increased markedly, and the expression of EGFR elevated moderately. More importantly, these alterations were consistent positively with the expression of p21, the protein product of H-ras oncogene. CONCLUSION: H-ras oncogene could induce the metastatic phenotype of HCC cell in vitro to raise its metastatic potential.

N-myc downstream regulated gene 1 inhibition of tumor progression in Caco2 cells

BACKGROUND Invasion and migration are the irreversible stages of colorectal cancer(CRC).The key is to find a sensitive,reliable molecular marker that can predict the migration of CRC at an early stage.N-myc downstream regulated gene 1(NDRG1)is a multifunctional gene that has been tentatively reported to have a strong relationship with tumor invasion and migration,however the current molecular role of NDRG1 in CRC remains unknown.AIM To explore the role of NDRG1 in the development of CRC.METHODS NDRG1 stably over-expressed Caco2 cell line was established by lentiviral infection and NDRG1 knock-out Caco2 cell line was established by CRISPR/Cas9.Furthermore,the mRNA and protein levels of NDRG1 in Caco2 cells after NDRG1 over-expression and knockout were detected by real-time polymerase chain reaction and western blot.The cell proliferation rate was measured by the cell counting kit-8 method;cell cycle and apoptosis were detected by flow cytometry;invasion and migration ability were detected by the 24-transwell method.RESULTS NDRG1 over-expression inhibited Caco2 proliferation and the cell cycle could be arrested at the G1/S phase when NDRG1 was over-expressed,while the number of cells in the G2 phase was significantly increased when NDRG1 was knocked out.This suggests that NDRG1 inhibited the proliferation of Caco2 cells by arresting the cell cycle in the G1/S phase.Our data also demonstrated that NDRG1 promotes early cell apoptosis.Invasion and migration of cells were extensively inhibited when NDRG1 was over-expressed.CONCLUSION NDRG1 inhibits tumor progression in Caco2 cells which may represent a potential novel therapeutic strategy for the treatment of CRC.

Identification of differentially expressed genes in normal mucosa,adenoma and adenocarcinoma of colon by SSH

AIM: To construct subtracted cDNA libraries and further identify differentially expressed genes that are related to the development of colorectal carcinoma(CRC). METHODS: Suppression subtractive hybridization(SSH) was done on cDNAs of normal mucosa, adenoma and adenocarcinoma tissues from the same patient. Three subtracted cDNA libraries were constructed and then hybridized with forward and backward subtracted probes for differential screening. Positive clones from each subtracted cDNA library were selected for sequencing and BLAST analysis. Finally, virtual Northern Blot confirmed such differential expression. RESULTS: By this way, there were about 3-4 X 10(2) clones identified in each subtracted cDNA library, in which about 85% positive clones were differentially screened. Sequencing and BLAST homology search revealed some clones containing sequences of known gene fragments and several possibly novel genes showing few or no sequence homologies with any known sequences in the database. CONCLUSION: All results confirmed the effectiveness and sensitivity of SSH. The differentially expressed genes during the development of CRC can be used to shed light on the pathogenesis of CRC and be useful genetic markers for early diagnosis and therapy.

Cloning of differentially expressed genes in human hepatocellular carcinoma and nontumor liver

INTRODUCTIONThe mechanism of hepatocellular carcinoma(HCC)is still unclear,although some genes have been found to play a role in the transformation of liver cells,and a variety of studies have described differences in gene expression which distinguished tumor from nontumor[1-6].The new genes,especially the functional genes directly related with tumor are still worth being found.The purpose of our study is to find the different genes between human liver tumor and normal tissues using suppression subtractive hybridization.

Transcriptional regulation of adult neural stem/progenitor cells: tales from the subventricular zone

In rodents,well characterized neurogenic niches of the adult brain,such as the subventricular zone of the lateral ventricles and the subgranular zone of the hippocampus,support the maintenance of neural/stem progenitor cells(NSPCs)and the production of new neurons throughout the lifespan.The adult neurogenic process is dependent on the intrinsic gene expression signatures of NSPCs that make them competent for self-renewal and neuronal differentiation.At the same time,it is receptive to regulation by various extracellular signals that allow the modulation of neuronal production and integration into brain circuitries by various physiological stimuli.A drawback of this plasticity is the sensitivity of adult neurogenesis to alterations of the niche environment that can occur due to aging,injury or disease.At the core of the molecular mechanisms regulating neurogenesis,several transcription factors have been identified that maintain NSPC identity and mediate NSPC response to extrinsic cues.Here,we focus on REST,Egr1 and Dbx2 and their roles in adult neurogenesis,especially in the subventricular zone.We review recent work from our and other laboratories implicating these transcription factors in the control of NSPC proliferation and differentiation and in the response of NSPCs to extrinsic influences from the niche.We also discuss how their altered regulation may affect the neurogenic process in the aged and in the diseased brain.Finally,we highlight key open questions that need to be addressed to foster our understanding of the transcriptional mechanisms controlling adult neurogenesis.

Methylation status of c-fms oncogene in HCC and its relationship with clinical pathology

INTRODUCTIONThe mechanism that DNA hypomethylation leads toactivation of oncogene and occurrence of malignantneoplasm is being increasingly recognized byresearchers. Normal DNA methylation playsimportant role in stabilizing the phenotype of cell.DNA methylation status reduction and/or patternalteration are related to activation and abnormallyhigh expression of some oncogenes and cellularmalignancy[1-6]. c-fms oncogene encodes for colonystimulating factor 1 receptor (CSF-1R)[7], c-fms/CSF-1R was highly expressed in hepatocellularcarcinoma (HCC) tissue, but the mechanismremained obscure[8,9].