Bioinformatics analysis of genes related to chromophobe renal cell carcinoma / 中国医师杂志

Objective:Bioinformatics was used to analyze the gene expression profile of renal chromophobe cell carcinoma (RCCC) to find out the key genes of RCCC.Methods:Chromophobe renal cell carcinoma gene chip data GSE15641 and GSE11151 were downloaded from the GEO database. Using R software packages such as " Affy" and " limma" in R software to screen differentially expressed genes, combining with David and STRING online bioinformatics tools to analyze the regulatory network of differentially expressed genes and construct protein-protein interaction (PPI) network, the Hub gene was screened through the Cytohubba plug-in of Cytoscape software.Results:A total of 261 differentially expressed genes were screened, including 194 down-regulated genes and 67 up-regulated genes. Gene enrichment (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were performed to explore their biological functions. In GO enrichment analysis, biological processes were mainly enriched in cell secretion, gluconeogenesis and cell proliferation regulation; in cell composition, they were mainly enriched in exosomes, plasma membranes and their components; in molecular function, they were mainly enriched in heparin binding; in KEGG pathway analysis, they were mainly enriched in metabolic pathway, antibody biosynthesis pathway and renin angiotensin system pathway. PPI network was constructed by using online bioinformatics tools. The top 10 Hub genes were screened by using cytohubba plug-in in Cytoscape software, which were pipecolic acid and sarcosine oxidase (PIPOX), hydroxyacid oxidase 2 (HAO2), kynurenine 3-monooxygenase (KMO), solute carrier family 2 member 2 (SLC2A2), formimidoyltransferase cyclodeaminase (FTCD), angiogenin (ANG), APOBEC1 complementation factor (A1CF), aldehyde dehydrogenase 8 family member A1 (ALDH8A1), vitamin D binding protein (GC), histidine rich glycoprotein (HRG).Conclusions:Bioinformatics analysis of differentially expressed genes in renal chromophobe cell carcinoma can effectively explore the interaction information of these differentially expressed genes, and provide new ideas for the treatment of renal chromophobe cell carcinoma.

Expression, purification of recombinant human cryptochrome I and its application in preparation of protective agent for radiotherapy / 生物工程学报

Radiotherapy is a treatment for cancer with undesired by-effects. In order to develop a new radiation protective agent that could reduce the by-effects, we tried to express and purify human cryptochrome 1 (hCRY1). The coding sequence of hCRY1 was inserted into prokaryotic expression plasmid pET28a(+), and this protein was purified from Escherichia coli BL21(DE3) after IPTG induction, ultrasonication, inclusion body dissolution, gradient dialysis, nickel column purification and ultrafiltration. The yield of hCRY1 in 1 L E. coli culture (LB medium) was about 10-15 mg. The radiation protective efficiency of hCRY1 was monitored by detecting X-ray-induced H2A.X foci in HaCaT cells. The results of immunofluorescence show that hCRY1 significantly reduces X-ray stimulated DNA damage response. The apoptosis of HaCaT cell was also detected, and the repression of H2A.X foci formation was not due to hCRY1's cytotoxity. All these data suggest a potential application of recombinant hCRY1 as a protective agent for radiotherapy.

Producing Ad-IFN gamma by suspension culture of HEK293 cells in a disposable bioreactor / 生物工程学报

Adenovirus vectors are promising delivery systems for gene therapy. We established a new process for clinic trial of recombinant adenovirus vectors using a novel disposable bioreactor. The suspension HEK293 cells were inoculated into a 5 L disposable bioreactor with parameters control of pH, DO, agitation and temperature. After 6 days of a fed-batch culture, the final cell density reached 2.0 x 10(6) cells/mL. The culture was infected with Ad-IFNγ at an MOI of 30. The harvest was performed at approximately 48 h post-infection and crude viral lysate was obtained after 3 freeze/thaw cycles and centrifugation. The maximum titers of crude viral lysate was 1.49 x 10(13) Infectious units (IFU) and the bulk product specific was 3,800 IFU/cell. Purified Ad-IFNγ by anion-exchange chromatography and the final recovery of infectious unit reached 35.9%. The result demonstrates that an efficient and stable process of producing Ad-IFNγ using a disposable fed-batch bioreactor is established.

Small interfering RNA-based molecular therapy of cancers / 癌症

RNA interference (RNAi) has become a gold standard for validating gene function in basic life science research and provides a promising therapeutic modality for cancer and other diseases. This mini-review focuses on the potential of small interfering RNAs (siRNAs) in anticancer treatment, including the establishment and screening of cancer-associated siRNA libraries and their applications in anticancer drug target discovery and cancer therapy. This article also describes the current delivery approaches of siRNAs using lipids, polymers, and, in particular, gold nanoparticles to induce significant gene silencing and tumor growth regression.

Immunological efficiency induced by HIV-1 p24 DNA combined with P24 protein / 生物工程学报

New strategies to improve vaccine efficacy against human immunodeficiency virus type 1 (HIV-1) are still required. DNA vaccines, exhibiting potential advantages over conventional vaccines for their simplicity and versatility, can induce specific humoral and cellular immune responses. We developed a recombinant pVAX1 DNA vector carrying p24 gene of HIV-1. The results showed that pVAX1 mediated gene possessed the ability of effective expression in both transfected 293T cells and BALB/c mice. And pVAX1-p24 DNA prime and boost immunization can induce significant P24-specific humoral immune responses and cellular immune responses in BALB/c mice. Furthermore, immunization with pVAX1-p24 DNA prime and protein boost induced 7.3 to 8.0-fold greater p24-specific humoral responses than pVAX1-p24 DNA prime and boost, while the cellular immune responses induced by combined immunization was lower. The results suggested that pVAX1-p24 DNA and P24 protein vaccine is a promising HIV-1 vaccine, and the selections of the immunization strategies are important for the immunization results.

Recombinant human endostatin improves tumor vasculature and alleviates hypoxia in Lewis lung carcinoma / 中华放射肿瘤学杂志

Objective To investigate whether recombinant human endostatin can create a time window of vascular normalization prior to vascular pruning to alleviate hypoxia in Lewis lung carcinoma in mice. Methods Kinetic changes in morphology of tumor vasculature in response to recombinant human endostatin were detected under a confocal microscope with immunofluorescent staining in Lewis lung carcinomas in mice. The hypoxic cell fraction of different time was assessed with immunohistochemical staining . Effects on tumor growth were monitored as indicated in the growth curve of tumors . Results Compared with the control group vascularity of the tumors was reduced over time by recombinant human endostatin treatment and significantly regressed for 9 days. During the treatment, pericyte coverage increased at day 3, increased markedly at day 5, and fell again at day 7. The vascular basement membrane was thin and closely associated with endothelial cells after recombinant human endostatin treatment, but appeared thickened, loosely associated with endothelial cells in control tumors. The decrease in hypoxic cell fraction at day 5 after treatment was also found. Tumor growth was not accelerated 5 days after recombinant human endostatin treatment. Conclusions Recombinant human endostatin can normalize tumor vasculature within day 3 to 7, leading to improved tumor oxygenation. The results provide important experimental basis for combining recombinant human endostatin with radiation therapy in human tumors.

Silencing suppressors: viral weapons for countering host cell defenses

RNA silencing is a conserved eukaryotic pathway involved in the suppression of gene expression via sequence-specific interactions that are mediated by 21-23 nt RNA molecules. During infection, RNAi can act as an innate immune system to defend against viruses. As a counter-defensive strategy, silencing suppressors are encoded by viruses to inhibit various stages of the silencing process. These suppressors are diverse in sequence and structure and act via different mechanisms. In this review, we discuss whether RNAi is a defensive strategy in mammalian host cells and whether silencing suppressors can be encoded by mammalian viruses. We also review the modes of action proposed for some silencing suppressors.

Polyethylenimine and minicircle DNA based gene transfer / 生物工程学报

Polyethylenimine (PEI) is one of the most characterized non-viral vectors. It can condense DNA in a good manner and achieve high transfection efficiency. Minicircle DNA (mc-DNA) is a novel kind of supercoiled DNA which is devoid of bacterial backbone. mc-DNA is superior to conventional DNA for its higher transfection efficiency and longer time-span. In this study, we combined PEI and mc-DNA in gene delivery system. We investigated the physicochemical and biochemical effects of this non-viral system and further explore its potential in tumor gene therapy. mc-DNA was obtained by recombination of parental plasmid in the presence of L-arabinose, and complexed with PEI. The results of transmission electron microscopy and scanning electron microscopy showed that the particles were spherical and homogeneous. Through gel retardation assay and MTT assay, we found that there were no obvious differences in binding capability of PEI to mc-DNA and plasmid DNA, as well as in cytotoxicity. The results of dynamic light scattering showed that the size of PEI/mc-DNA was about 68 nm, a slight larger than that of PEI/plasmid DNA. Furthermore, the tumor cells transfected with mc-GFP showed higher GFP expression level than that of conventional plasmid. The same results were achieved in the cells treated with tumor-suppressor gene pten, assayed by RT-PCR and Western blot. It indicates that the system of PEI/minicircle DNA is promising in gene transfer.

EXPRESSION AND BIOLOGICAL ACTIVITY ANALYSIS OF RECOMBINANT ADENOVIRUS EXPRESSION VECTOR FOR RECEPTOR TrkC OF NEUROTROPHIN-3 / 解剖学报

Objective To detect the expression and the biological activity of a recombinant adenovirus expression vector carrying human neurotrophin-3 (NT-3) receptor TrkC gene (Adeno-TrkC) in neural stem cells. Methods The expression of TrkC mRNA in 293 cells infected with Adeno-TrkC was detected by RT-PCR, and the expression of TrkC protein in neural stem cells infected by Adeno-TrkC was detected with immunocytochemistry and Western blotting. The effects of human neurotrophin_3 (NT-3) on the neural stem cells infected by Adeno-TrkC differentiating into neuron-like cells and astrocyte-like cells in vitro were observed. Results The transcription of TrkC mRNA and the expression of TrkC protein was detected in 293 cells and neural stem cells infected by Adeno-TrkC. This kind of TrkC was able to make more neural stem cells differenting into neuron-like cells in vitro with its ligand NT-3 and the percentage of neuron-like cell’s differentiation was 55

Combinative grafting neural stem cells and NT-3 genetically modified Schwann cells to promote the injured neurons'survival and axonal regeneration of the transected spinal cord rat / 中华显微外科杂志

Objective To explore the effects of neurotrophin-3 genetically modified Schwann cells(NT-3-SCs) and neural stem cells(NSCs) combinative transplantation to promote the neurons'survival and axonal regeneration of the spinal cord transected rat. Methods After the transected spinal cord injury(SCI) model was established in SD rats,NT-3-SCs or LacZ report gene modified Scwhann cells(LacZ-SCs) were combinative transplanted with NSCs into the transected site.60 days later,fluorogold(FG) was injected into the caudal spinal cord fo the transected site.7days after FG injected,the sacrifice,cryosection and morphology serious studies were performed to observe the FG labeled neurons in the rostral spinal cord(RSC) of transected site,red nuclei(RN) and the sensorimotor cortex(SMC);The survival neurons in the L_1 Clark's nuclei(CN),RN and SMC were couut,and regenerated axons within or near the transected spinal cord observed. Results From more to less,the order of groups of the survival neurons in the CN,RN and SMC was NT-3-SCS & NSCs group,LacZ-SCs & NSCs group,experimental control group.In the NT-3-SCs & NSCs group and LacZ-SCs & NSCs group,there were 5-HT,CGRP and SP positive axons within or near the transected spinal cord.And some FGlabeled cells were found in RSC,RN and SMC. Conclusion Combinative grafting NSCs and NT-3-SCs could promote the neurons'survival and axonal regeneration of the spinal cord injured rat.

NT-3 genetically modified Schwann cells promote neural stem cells to differentiate into neuron-like cells / 中国病理生理杂志

AIM: To explore the effects of neurotrophin-3 (NT-3)-genetically modified Schwann cells (NT-3-SCs) on differentiation of neural stem cells (NSCs) into the neuron-like cells. METHODS: The NSCs were co-cultured with NT-3-SCs. Report gene LacZ genetically modified Schwann cells (LacZ-SCs) and normal SCs respectively in vitro. 7 d later, the differentiation of NSCs was studied by immunohistochemistry, and the percentage of neuron-like cells was calculated. RESULTS: NSCs differentiated to the GFAP-positive cells (glial-like cells) and NF-positive cells (neuron-like cells) in vitro. Compared to the normal SCs, NT-3-SCs more efficiently promoted NSCs to differentiate into the neuron-like cells. The effect of LacZ-SCs was as the same to the normal SCs. CONCLUSION: NT-3-SCs promote NSCs to differentiate into the neuron-like cells. [