Molecular characterization and expression pattern analysis of a novel stress-responsive gene ‘BeSNAC1’ in Bambusa emeiensis

NAC transcription factors (TFs) are master regulators of environmental stresses exerting a crucial role in plant growth and development. However, the studies on NAC TFs from Bambusa emeiensis are scarce. In this investigation, a novel gene from B. emeiensis encoding NAC protein was cloned and characterized. The gene was isolated based on the amino acid sequence data of stress-responsive SNAC1 of rice, named ‘BeSNAC1 (accession no. MG763922)’. The full-length sequence of 1681 bp was found to contain an open-reading frame of 912 bp that encode a protein of 303 amino-acid residues. The multiple protein sequence alignments unveiled that BeSNAC1 contains a typical NAC domain. Additionally, the phylogenetic analysis showed that the corresponding protein belonged to the SNAC group, as it cladded with SNAC1, HvSNAC1, TaNAC2, SbSNAC1 and ZmSNAC1 proteins. Transactivation and subcellular localization assay disclosed that BeSNAC1 is a transcriptional activator localized in the cell nucleus.Moreover, the time-dependent expression pattern of BeSNAC1 was profiled under abscisic acid (ABA), polyethylene glycol 6000 (PEG-6000), NaCl, H2O2 and Na2SO4 treatments via a quantitative real-time polymerase chain reaction. The results revealed that the expression of BeSNAC1 was significantly upregulated in all treatments, a significant difference was observed under H2O2, NaCland ABA (P 0.001) and PEG and Na2SO4 (P < 0.01) treatments, respectively. Conclusively, our findings provide evidence that ‘BeSNAC1’ is a nuclear protein that might act as part of the transcription regulation complex and is involved in the ABA signalling pathway and abiotic stress tolerance mechanisms in B. emeiensis.

Role of vitamin D receptor in the regulation of gene expression

Vitamin D (VD) is a multifunctional nutrient which can be either synthesized or absorbed from the diet. It plays a pivotal role in systemic calcium and phosphate homeostasis, as well as in various physiological and pathological processes. VD is converted to the active form, 1,25-dihydroxyvitamin D (1,25-D3), by cytochrome P450 2R1 (CYP2R1)/CYP27A1 and CYP27B1 sequentially, and deactivated by multiple enzymes including CYP3A4. On the other hand, 1,25-D3 is capable of activating the transcription of genes in humans, mice and rats. The vitamin D receptor (VDR)-mediated transactivation of human and resembles that known for pregnane X receptor (PXR). Activated VDR forms a heterodimer with retinoid X receptor (RXR), recruits co-activators, translocates to the cell nucleus, binds to the specific vitamin D responsive elements (VDRE), and activates the gene transcription. In mice, intestinal mRNA levels, but not those of hepatic CYP3As, were induced by administration of VDR and PXR agonists. In rats, intestinal and mRNAs were induced by 1,25-D3 or lithocholic acid (LCA), whereas hepatic , but not and , was modulated to 1,25-D3 treatment. In general, the VDR-mediated regulation of CYP3A presents species and organ specificity.

Clinical Characteristics and Gene Mutations Analysis of a ALS10 Chinese Han Family / 中山大学学报(医学科学版)

[Objective] To explore the clinical features,genetic characters in family amyotrophic lateral sclerosis (ALS10)patients.[Methods] TARDBP gene mutations in Chinese Han family patients with ALS10 diagnosed by the First Affiliated Hospital of Sun Yat-sen University in 2013 was screened by high-throughput sequencing.[Results] There were 5 patients in three generations in this family.The initial symptoms in all affected members were distal limb muscle weakness and dystrophy at their 50 age.With a rapid progression of symptoms about 8 to 18 months.A homozygous missense mutation (c.892G＞A) were detected in TARDBP gene exon 6 of the propositus,as well as the other three family members without any clinical symptoms.[Conclusion] ALS10 is a faster progressive and shorter survival time FALS.Since there was no effective treatment in ALS10,hereditary consultation and prenatal diagnosis play an important role in disease prevention and hereditary.

Receptor activation of curcumin on human peroxisome proliferators-activated receptors γ1 / 中草药

Objective: To determine whether curcumin is a natural ligand for human peroxisome proliferators-activated receptors γ1 (hPPARγ1) by measuring the combination ability and internal activity. Methods: The combination ability was determined by radioactively labeled ligand binding experiment (RBCA), and the internal activity was estimated by trans-activation reporter gene test. Results: The combination ability of curcumin on hPPARγ1 showed that IC50 was (8.82 ± 0.74) μmol/L, and Ki was 0.72 μmol/L. The internal activity showed that EC50 was 7.3 μmol/L and Emax was 43.3. Conclusion: Curcumin has affinity and intrinsic activity with hPPARγ1, which suggests that curcumin may be a natural ligand of hPPARγ1.

Cross-talk of GPCRs and RTKs and its effects on oncotherapy / 中国药理学通报

G protein-coupled receptors (GPCRs) are the largest cell surface receptor family, which mediates activities of almost all known cellular response to ligands, including hormones release, neurotransmitters and sensory input.GPCRs can promote development and progression of gastric cancer, colorectal cancer, lung cancer and breast cancer and other tumors.Tyrosine kinase receptors (RTKs) are another important family of membrane receptors, which can regulate cell proliferation, differentiation, migration and survival.Overexpression of RTKs has been found in many cancer cells.Therefore, GPCRs and RTKs are equally important in the clinical treatment of cancer therapeutic.However, GPCRs and RTKs are not independent, and they can use common signal transduction.The present study show that crosstalk between GPCRs and RTKs can facilitate migration of lung epithelial cells, increasing survival of nerve cells and promoting tumor occurrence and development.This article mainly focuses on crosstalk between GPCRs and RTKs and their roles in tumorigenesis and oncotherapy.

Steroid hormone receptors and prostate cancer: Role of structural dynamics in therapeutic targeting / 亚洲男科学杂志(英文版)

Steroid hormone receptors (SHRs) act in cell type- and gene-specific manner through interactions with coregulatory proteins to regulate numerous physiological and pathological processes at the level of gene regulation. Binding of steroid receptor modulator (SRM) ligand leads to allosteric changes in SHR to exert positive or negative effects on the expression of target genes. Due, in part, to the fact that current SRMs generally target ligand binding domain (LBD)/AF2 and neglect intrinsically disordered (ID) N-terminal domain (NTD)/AF1, clinically relevant SRMs lack selectivity and are also prone to the development of resistance over time. Therefore, to maximize the efficacy of SHR-based therapeutics, the possibility of developing unique modulators that act to control AF1 activity must be considered. Recent studies targeting androgen receptor′s (AR′s) ID AF1 domain for the castration-resistant prostate cancer has provided the possibility of therapeutically targeting ID NTD/AF1 surfaces by allosteric modulations to achieve desired effects. In this review article, we discuss how inter- and intra- molecular allosteric regulations controlled by AR′s structural flexibility and dynamics particularly the ID NTD/AF1 is an emerging area of investigation, which could be exploited for drug development and therapeutic targeting of prostate cancer.

Hepatitis B virus preS2 activates human acyl protein thioesterase 1 promoter / 重庆医学

Objective To investigate the trans‐regulative effect of hepatitis B virus (HBV) preS2 on the promoter of human acyl protein thioesterase 1 (APT1) gene .Methods The promoter sequence of human APT1 gene was identified applying the soft‐ware of bioinformatics .The APT1 promoter and HBV preS2 gene were amplified with PCR and cloned into pGL3 and pcDNA3 .1 (-) plasmids to construct the luciferase reporter gene plasmid of human APT1 gene promoter pGL3‐APT1 and the preS2 eukary‐otic expression plasmid pcDNA3 .1(-)‐preS2 ,respectively .The effect of the preS2 on the human APT1 gene promoter was exam‐ined by cotransfecting hepatocellular carcinoma cell HepG2 with pGL3‐APT1 and pcDNA3 .1(-)‐preS2 and measuring luciferase activities of the HepG2 cells .The statistical data were analyzed with independent‐samples t test .Results Both plasmids of pGL3‐APT1 and pcDNA3 .1(-)‐preS2 were confirmed by DNA sequencing to be accurately constructed as design .The luciferase activity of the pGL3‐APT1 was 1 .2 times (P<0 .01) that of the positive control plasmid pGL3‐Control .And the luciferase activity of the HepG2 cells cotransfected with pcDNA3 .1(-)‐preS2 and pGL3‐APT1 was 2 .6 times (P<0 .01) that of the HepG2 cells cotrans‐fected with the plasmid without preS2 gene pcDNA3 .1(-) and pGL3‐APT1 .Conclusion The human APT1 promoter cloned in the study has high promoter activity ;HBV preS2 activates human APT1 promoter .

Mechanisms of STAT family mediated IDO regulation in dendritic cells / 国际肿瘤学杂志

Indoleamine 2,3-dioxygenase (IDO) is known as an endogenous immunosuppressive enzyme which plays a significant role in the process of tumor.IDO is not only found in tumor cells but also detected in dendritic cell (DC) in tumor microenvironment,which participates in the formation of tumor immune tolerance through expressing IDO enzyme.Signal transducer and activator of transcription (STAT) is the main signal protein family which participates in the IDO transcriptional regulation of DC.It is necessary to detail the signaling pathway in regulating IDO expression,which will help us develop high specific and more active IDO inhibitors and provide new options for anti-cancer targeted therapy.

Functional Interaction of HIF-1 and NF-kappaB Increasing the Transcriptional Activation of TNF-alpha Gene in Monocytes / 대한수혈학회지

BACKGROUND: Tumor necrosis factor alpha (TNF-alpha) is a pleiotropic cytokine fulfilling a broad variety of immunoregulatory functions. Monocytes and macrophages play a pivotal role in inflammation and immune regulation. NF-kappaB and HIF-1 are known to increase expression of the TNF-alpha gene in a separate way. METHODS: Human monocytic leukemia, U937 cells, were transfected using the standard electroporation method for intracellular expression of NF-kappaB and HIF-1. We performed analysis using the mammalian two-hybrid assay and co-immunoprecipitation assay for detection of protein interaction of both proteins. In addition, chromatin immunoprecipitation analysis was performed for examination of NF-kappaB and HIF-1 binding on the TNF-alpha gene promoter. RESULTS: Here we show that NF-kappaB and HIF-1 cooperatively induced an increase in expression of the TNF-alpha gene dependent on promoter activity by the direct protein interaction of these two transcription factors. Hypoxia signaling induced marked enhancement of the transactivation of TNF-alpha promoter by HIF-1 and NF-kappaB. A tandem NF-kappaB/HIF-1 binding site was identified within the TNF-alpha promoter, which acted as a strong enhancer element. Physical association of the Rel domain of NF-kappaB and the N-TD domain of HIF-1 was required. Hypoxia treatment also resulted in a significant increase in the protein interaction of NF-kappaB and HIF-1 in vivo. Both transcription factors were recruited on the chromatin TNF-alpha promoter dependent on hypoxia stimuli. CONCLUSION: The results of this study indicate that a variety of extracellular signals for activation of TNF-alpha gene expression might converge on the transcriptional regulation through the NF-kappaB/HIF-1 signaling pathway.

dBcAMP Induces Morphological Changes of Asrocytes through Epidermal Growth Factor Receptor / 中国医科大学学报

Objective To study the signaling transduction of dBcAMP induced morphological changes of astrocytes.Methods Morphological changes of primarily cultured mouse astrocytes induced by dBcAMP were studied by immunocytochemical technique.The signaling transduction pathways underlying those changes were further explored using specific inhibitors AG1478 and GM6001.Results Zn2＋-dependent metalloproteinase and epidermal growth factor receptor（EGFR）in astrocytes were involved in the morphological changes of astrocytes induced by dBcAMP.Conclusion dBcAMP-induced transactivation pathways were delineated in the morphological changes of astrocytes.

Effects of the splicing-specific protein on the regulatory elements of hepatitis B virus per se / 中华微生物学和免疫学杂志

Objective To investigate the effects of the novel protein,TPds encoded by the 2.2 kb doubly spliced variant of hepatitis B virus(HBV)genome on the regulatory elements of HBV.Methods HBV promoters and enhancers were amplified by PCR and respectively cloned into the plasmid pGL3-basic to construct the recombinant firefly luciferase reporter vectors including pGL3-BCP(harboring basal core promoter),pGL3-CP1601(core promoter with enhancer Ⅱ),pGL3-XP(minimal X gene promoter),pGL3 XP1071(X gene promoter with enhancer Ⅰ),pGL3-SP1(promoter of large surface antigen)and pGL3-SP2 (promoter of middle surface antigen).The recombinant reporter plasmids were respectively co-transfected with either the pcDNA3.1/HisC-TPds(TPd8 expression plasmid)or pcDNA3.1/HisC(empty control)into Huh7 hepatocytes by FuGENE6 transfection reagent.Cells were lysed 48 h post transfection,the intracellulax luciferase activities were monitored and calculated by SPSS11.5 software.Results As compared with the empty control of pcDNA3.1/HisC.the intracellular luciferase activities were elevated when the Huh7 hepatocytes were co-transfected by pcDNA3.1/HisC-TPds with one of the recombinant reporter plasmids as pGL3-CP1601,pGL3-XP1071,pGL3-SP1,or pGL3-SP2,while no changes with pGL3-BCP or pGL3-XP.Conduslon TPds could transactivate the HBV regulatory elements a8 promoter SP1,SP2.and enhancer Ⅰ,Ⅱ,while no influences on basal core promoter and minimal X gene promoter.

The correlation of IL-8 signaling pathway and EGFR pathway in MDA-231 cells of breast carcinoma / 中华微生物学和免疫学杂志

Objective To study the effect of IL-8 on cell proliferation and invasion,and to analyze the correlations between chemokine and epidermal growth factor receptor(EGFR)signaling pathways in breast carcinoma cells.Methods IL-8 secretion responded to treatment with rhEGF and anti-EGFR and expression of its receptors CXCR1,CXCR2 in MDA-231 cells were measured by ELISA and immunocytochemistry,respectively.Effect of rhIL-8 and neutralizing antibody on cell proliferation and invasion were analyzed by using MTT and matrigel invasion assay.EGFR transactivation stimulated with rhIL-8 and neutralizing an tibody was assessed by Western blot using anti-phosphotyrosine antibody.Results MDA-231 cells released hish level of IL-8 and two receptom of IL-8(CXCR1 and CXCR2)both expressed on cell membrane.Exogenous IL-8 and its neutralizing antibody did not significantly influence the proliferation of breast carcinoma cells,but rhIL-8 stimulated invasive activity in MDA-231 cells and its neutralizing antibody inhibited the in vasive activity(P＜0.05).EGF and anti-EGFR both inhibited the secretion of IL-8 in breast carcinoma cells,and IL-8 had no effect on EGFR phosphorylation,but anti-IL-8 induced transactivation of EGFR after 24h.Conclusion IL-8 contributes to tumor progression in breast carcinoma through its enhancement of in vasive activitv but not act as an autocrine growth factor.The correlation of competitive inhibition rather than cross-talk is found between G protein coupled receptor(GPCR)-mediated IL-8 signaling pathway and EGFR pathway in breast carcinoma.

Viral Transactivation of Transcription in Steroid Responsive Simple Nephrotic Syndrome Mediated by Nuclear Factor-Kappa B/Inhibitor Protein-Kappa B Signal Pathway / 实用儿科临床杂志

Objective To investigate the role of nuclear factor-kappa B(NF-?B)/inhibitor protein-kappa B(I?B) signal pathway in viral transactivation of transcription in steroid responsive simple nephrotic syndrome(SRSNS).Methods Children with SRSNS(inclu-ding active stage and remissive stage) were examined,and were compared to children with nephritic nephrosis,secondary glomerular di-seases,bronchiolitis and healthy children.Electro-mobility shift assays,reverse transcription-polymerase chain reaction(RT-PCR) and enzyme-linked immunosorbent assay(ELISA) were used to detect the activity of NF-?B,the gene expression of respiratory tract viruses (including respiratory syncytial virus and influenza virus) in peripheral blood mononuclear cells(PBMCs) and the levels of viral antibody in plasma,respectively.The protein levels of I?B? and IL-8 were measured through Western blot and ELISA in SRSNS at active stage and healthy children.Results Compared with SRSNS at remissive stage and other groups,the activity of NF?B in SRSNS at active stage was much higher.And there was a positive linear correlation trend between the activity of NF-?B and the gene expression of respiratory tract viruses in SRSNS at active stage.With healthy children,the level of IL-8 in plasma from SRSNS at active stage was significantly increased.There was a positive correlation between the activity of NF?B and the level of IL-8(r=0.88 P

Hypoxia activates the cyclin D1 promoter via the Jak2/STAT5b pathway in breast cancer cells

Hypoxia, a common consequence of solid tumor growth in breast cancer or other cancers, serves to propagate a cascade of molecular pathways which include angiogenesis, glycolysis, and various cellcycle control proteins. As we have shown previously, hypoxia activates STAT5 (signal transducer and activator of transcription 5) and increases its binding activity to the GAS element in mammary epithelial cells. In this study we attempted to elucidate the mechanism by which cyclin D1 is regulated by the STAT5 protein under hypoxic conditions. Our data demonstrate that hypoxia (2% O2) or desferrioxamine (DFO) induces tyrosine and serine phosphorylation of STAT5 in human breast cancer cells (MCF-7) and mammary epithelial cells (HC11). Imunoprecipitation and subsequent Western analysis showed that Jak2 leads to the tyrosine phosphorylation and activation of STAT5a or STAT5b under hypoxic conditions. Using a transfected COS-7 cell model system, we demonstrate that the activity of a cyclin D1 promoter-luciferase construct increased under hypoxic conditions or DFO treatment. The activity of the STAT5b/cyclin D1 promoter increased significantly by 12 h of hypoxia, whereas the activity of the STAT5a/cyclin D1 promoter was unaffected under hypoxic conditions. These increases in promoter activity are predominantly mediated by the Jak2/ STAT5b signaling pathway. We have shown by EMSA that hypoxia induces STAT5 to bind to the cyclin D1 promoter (GAS-1) in MCF-7 and HC11 cells. These data suggest that STAT5b may mediate the transcriptional activation of cyclin D1 after hypoxic stimulation.

Identification of a putative transactivation domain in human Nanog

Nanog is a newly identified divergent homeodomain protein that directs the infinite propagation and sustains the pluripotency of embryonic stem cells. It has been reported that murine Nanog has two potent transactivation domains in N-terminal and C-terminal regions. Human Nanog (hNanog) polypeptide shares about 58% and 87% identity to the open reading frame and homeodomain of murine Nanog, respectively. However, the functional domains and molecular mechanisms of hNanog are poorly understood. In this study, for the first time, we presented that only C-terminus of hNanog contains a potent transactivation domain. Based on the amino acid sequences of homeobox domain, we roughly divided hNanog open reading frame into the three regions such as N-terminal, homeodomain and C-terminal regions and constructed either the fusion proteins between hNanog individual and Gal4 DNA binding domain or the context of native hNanog protein. Reporter assays by using reporter plamid containing Gal4 or Nanog binding site revealed that the only C-terminal region exhibited the significant fold induction of transactivation. However, interestingly, there was no significant activation through N-terminal region unlike murine Nanog, suggesting that C-terminal region may have more critical roles in the transcriptional activation of target genes. Taken together, the finding of a putative transactivation domain in hNanog may contribute to the further understanding of molecular mechanism on the regulation of downstream genes involved in self-renewal and pluripotency of human stem cells.

Study Progress of Biological Function of Hepatitis B Virus X Protein and Signal Transduction / 实用儿科临床杂志

Hepatitis B virus X protein(HBx) has a wide range of biological effects.It not only play important roles in the replication of the virus,but also in infects host cell proliferation and apoptosis,as well as the incidence of hepatocellular carcinoma.HBx trans-activation has a broad regulatory role in the virus itself and host genes.HBx,by interfering with multiple signaling pathways,affected a variety of biological characteristics of the host cell.

A Human Immunodeficiency Virus Type 1 (HIV-1) Tat Cofactor Absent in Rodent Cells is a TAR-associated Factor

BACKGROUND: Although Tat plays a role as a potent transactivator in the viral gene expression from the Human Immunodeficiency Virus type 1 long terminal repeat (HIV-1 LTR), it does not function efficiently in rodent cells implying the absence of a human specific factor essential for Tat-medicated transactivation in rodent cells. In previous experiments, we demonstrated that one of chimeric forms of TAR (transacting responsive element) of HIV-1 LTR compensated the restriction in rodent cells. METHODS: To characterize the nature of the compensation, we tested the effects of several upstream binding factors of HIV-1 LTR by simple substitution, and also examined the role of the configuration of the upstream binding factor(s) indirectly by constructing spacing mutants that contained insertions between Sp1 and TATA box on Tat-mediated transactivation. RESULTS: Human Sp1 had no effect whereas its associated factors displayed differential effects in human and rodent cells. In addition, none of the spacing mutants tested overcame the restriction in rodent cells. Rather, when the secondary structure of the chimeric HIV-1 TAR construct was destroyed, the compensation in rodent cells was disappeared. Interestingly, the proper interaction between Sp1 and TATA box binding proteins, which is essential for Tat-dependent transcription, was dispensable in rodent cells. CONCLUSION: This result suggests that the human-specific Tat cofactor acts to allow Tat to interact effectively in a ribonucleoprotein complex that includes Tat, cellular factors, and TAR RNA, rather than be associated with the HIV-1 LTR upstream DNA binding factors.

A Human Immunodeficiency Virus Type 1 (HIV-1) Tat Cofactor Absent in Rodent Cells is a TAR-associated Factor

BACKGROUND: Although Tat plays a role as a potent transactivator in the viral gene expression from the Human Immunodeficiency Virus type 1 long terminal repeat (HIV-1 LTR), it does not function efficiently in rodent cells implying the absence of a human specific factor essential for Tat-medicated transactivation in rodent cells. In previous experiments, we demonstrated that one of chimeric forms of TAR (transacting responsive element) of HIV-1 LTR compensated the restriction in rodent cells. METHODS: To characterize the nature of the compensation, we tested the effects of several upstream binding factors of HIV-1 LTR by simple substitution, and also examined the role of the configuration of the upstream binding factor(s) indirectly by constructing spacing mutants that contained insertions between Sp1 and TATA box on Tat-mediated transactivation. RESULTS: Human Sp1 had no effect whereas its associated factors displayed differential effects in human and rodent cells. In addition, none of the spacing mutants tested overcame the restriction in rodent cells. Rather, when the secondary structure of the chimeric HIV-1 TAR construct was destroyed, the compensation in rodent cells was disappeared. Interestingly, the proper interaction between Sp1 and TATA box binding proteins, which is essential for Tat-dependent transcription, was dispensable in rodent cells. CONCLUSION: This result suggests that the human-specific Tat cofactor acts to allow Tat to interact effectively in a ribonucleoprotein complex that includes Tat, cellular factors, and TAR RNA, rather than be associated with the HIV-1 LTR upstream DNA binding factors.

Prokaryotic expression and bioinformatics analysis of NS5A transactivating protein 7 of hepatitis C virus / 解放军医学杂志

Objective To construct prokaryotic expression vector of NS5A transactivating protein 7 of hepatitis C virus (NS5ATP7), induce the expression of NS5ATP7 in E. coli, and to predict its structure and function by bioinformatics analysis. Methods NS5ATP7 gene was amplified by reverse transcription PCR (RT-PCR) using HepG2 cells mRNA as template, and was ligated into pGEM-T cloning vector. After verifying the sequence of the inserted fragment by restriction enzyme digestion identification and sequencing, NS5ATP7 was cloned into inducible prokaryotic expression vector pET-32a(+) and transfected into competent E. coli BL21. The protein expression was induced with IPTG and the product was analyzed by SDS-PAGE and Western blotting hybridization. The structure and function of NS5ATP7 were predicted using bioinformatics techniques. Results NS5ATP7 gene with about 891bp was amplified by RT-PCR, which was coincident with that we expected, and it was then inserted into expression vector pET-32a(+). Under the induction of IPTG, the recombinant NS5ATP7 was expressed successfully. SDS-PAGE and Western blotting assay showed that this recombinant protein possessed good immunogenicity. Bioinformatics method such as ExPASy, TMHMM and SignalP analysis indicated that NS5ATP7 was full of helices, had neither transmembranous structure nor signal peptide. Conclusions The recombinant NS5ATP7 gene could be successfully expressed in prokaryotic expression system of E. coli, which might lay the foundation of studying the immunogenicity and biological charactersitics of the NS5ATP7. Bioinformatics analysis may provide a new method to analyze the structure and function of a new protein.

The study on genes trans-regulated by XTP4 using suppression subtractive hybridization technique / 解放军医学杂志

Objective To explore the influence of XTP4 on genomic expression profile of hepatocyte through screening and cloning of genes trans-regulated by XTP4-expressing plasmid. Methods The expressive vector pcDNA3.1(-)-XTP4 was constructed by routine molecular biological methods, and suppression subtractive hybridization (SSH) method was employed to detect the mRNA differentially expressed by the HepG2 cells transfected with pcDNA3.1(-)-XTP4 and pcDNA3.1(-), respectively, using lipofectamine. The twice enriched PCR products were subcloned into T/A vectors to set up the subtractive library. Amplification of the library was carried out in E. coli strain JM109. The screened cDNA were sequenced and analyzed in GenBank with Blast search after PCR. Results The amplified subtractive library containd 21 positive clones. Colony PCR analysis showed that there were 16 clones containing 200-1000bp inserts. Sequence analysis was performed and 9 kinds of encoding sequences were achieved. These genes trans-regulated by XTP4 protein involved in hepatic fibrogenesis, tumorgenesis, mitochondrial function, and cell growth regulation. Conclusions The findings obtained by SSH provide significant data for a preliminary understanding of the biological function of a new identified gene-XTP4. These results will pave the way for the study of the molecular mechanism of the transactivating effects of HBxAg and the development of new therapy for chronic hepatitis B.