可体内、外示踪的BMP2真核表达载体的构建和表达

Objective To construct green fluorescent protein (GFP)-labeled pSELECT-GFP zeohBMP2 eukaryotic expression vector. Methods The encoding fragment of hBMP2 gene was obtained from a recombinant plasmid pcDNA3.1/CT-hBMP2 by using polymerase chain reaction (PCR). hBMP2 gene was inserted into pTA2-T-easy and pSELECT-GFPzeo-MCS eukaryotic expression vector, and then transferred into competence DHSα cells. After screening, pSELEC-GFPzeo-hBMP2 was obtained and identified by sequence analysis. The recombinant vector pSELECT-GFP zeo-rhBMP2 was transfected into CHO cells. The successful trasfection was verified by fluorescence microscope in 48-72 hours. The RT-PCR and immunofluorescence was used to confirm the hBMP2 expression. Western Blotting was used to detect the secretion of hBMP2.Results A 1216 bp fragment was obtained by PCR, the same as expectant fragment. The recombined pSE-LECT-GFPzeo-hBMP2 eukaryotic expression vector was identified by restriction mapping and sequence analysis. The results were identical with that of reported hBMP2 sequence (Genebank NM-001200). The successful transfection was verified by fluorescence microscope in 48-72 hours. The stable expression in eukaryotic cells was confirmed by immunofluorescence and RT-PCR which showed an obvious band between 1000-2000 bp. Western Blotting identified the immunogenicity of recombinant human BMP2 with the molecular weight of about 17×103. Conclusion The pSELECT-GFPzeo-hBMP2 eukaryotic expression vector was constructed successfully.     

Lentivirus-mediated SMO RNA interference inhibits SMO expression and cell proliferation,and affects the cell cycle in LNCaP and PC3 cancer cell lines

Smoothened （SMO） is an important member of the Hedgehog signaling pathway. We constructed a specific recombinant lentiviral vector for RNA interference,targeting the SMO gene （NM_005631） to observe its effect on SMO expression,cell proliferation and the cell cycle in the human androgen-sensitive prostate cancer cell line,LNCaP,and in the androgen-independent prostate cancer cell line,PC3. Four siRNA sequences were designed and inserted into a lentiviral vector pGCSIL-GFP to construct four recombinant vectors. The vector with the highest interfering efficiency was co-transfected with packaging vectors （pHelper1.0 and pHelper2.0） in 293T cells to assemble lentivirus particles by liposome for infecting LNCaP and PC3 cell lines,respectively. The expression level of SMO mRNA,tumor cell proliferation and cell cycle were measured by quantitative realtime polymerase chain reaction （qRT-PCR）,3-（4,5）-dimethylthiahiazo （-z-yl）-3,5-di-phenytetrazoliumromide （MTT） assay and flow eytometry,respectively. Sequence results showed that recombinant lentiviral vectors were constructed successfully.pGCSIL-GFP-723 had the highest interfering efficiency,named Lv-SIL-SMO723 after co-transfection,with which LNCaP and PC3 cell lines were infected. Compared with the control groups,results showed significantly decreased （P〈0.05） SMO mRNA expressions of LNCaP and PC3,lower mean percentage of S-phase cells and higher mean percentage of G_2/M phase cells,as well as obviously slow proliferation （P〈0.01） of LNCaP in the infected group. Yet,the proliferation of PC3 was not altered （P〉0.05）. In conclusion,the recombinant lentivirus particles were able to suppress SMO expression,regulate the cell cycle in the LNCaP and PC3 cell lines and markedly inhibit proliferation of LNCaP cells but not PC3 cells.     

靶向Survivin的siRNA联合吉西他滨抑制胰腺癌细胞增殖

Objective To construct the siRNA eukaryotic expression vector targeting Survivin gene, and investigate the chemotherapy sensitivity of pancreatic cancer line Panc-1 treated by gemcitabine. Methods The siRNA eukaryotic expression vector targeting Survivin gene was constructed. Panc-1 cells were transfected with negative control vector or siRNA vector and selected by G418, and the cell growth curve was drawn. The expression of Survivin mRNA and protein was detected by RT-PCR and Western blot respectively. Panc-1 cells or transfected cells were treated with gemcitabine for 24 h,and then the growth inhibition rate was measured by MTT assay, and cell apeptosis rate was measured by flow cytometry. Results The result of endonuclease digestion and DNA sequencing revealed that the recombinant plasmid psiRNA-Survivin was constructed successfully. Survivin mRNA and protein levels were reduced by 79.2% and 83.6% respectively in stably transfected Panc-1 cells as compared with control group, and the cell growth curve was much smoother, and the growth inhibition rate [ ( 24.6±4.5 ) % / (38.7±5.2 ) % ] and apoptosis rate of these cells [ ( 16.7±2.5 ) %/( 26.8±3.4 ) % ] were significantly increased after treatment by gemcitabine (P < 0.05 ). Conclusion The constructed siRNA eukaryotie expression vector targeting Survivin could decrease the Survivin expression,inhibit the growth of Panc-1 cells significantly,and increase the chemotherapy sensitivity to gemcitabine.     

靶向Survivin的siRNA联合吉西他滨抑制胰腺癌细胞增殖

Objective To construct the siRNA eukaryotic expression vector targeting Survivin gene, and investigate the chemotherapy sensitivity of pancreatic cancer line Panc-1 treated by gemcitabine. Methods The siRNA eukaryotic expression vector targeting Survivin gene was constructed. Panc-1 cells were transfected with negative control vector or siRNA vector and selected by G418, and the cell growth curve was drawn. The expression of Survivin mRNA and protein was detected by RT-PCR and Western blot respectively. Panc-1 cells or transfected cells were treated with gemcitabine for 24 h,and then the growth inhibition rate was measured by MTT assay, and cell apeptosis rate was measured by flow cytometry. Results The result of endonuclease digestion and DNA sequencing revealed that the recombinant plasmid psiRNA-Survivin was constructed successfully. Survivin mRNA and protein levels were reduced by 79.2% and 83.6% respectively in stably transfected Panc-1 cells as compared with control group, and the cell growth curve was much smoother, and the growth inhibition rate [ ( 24.6±4.5 ) % / (38.7±5.2 ) % ] and apoptosis rate of these cells [ ( 16.7±2.5 ) %/( 26.8±3.4 ) % ] were significantly increased after treatment by gemcitabine (P < 0.05 ). Conclusion The constructed siRNA eukaryotie expression vector targeting Survivin could decrease the Survivin expression,inhibit the growth of Panc-1 cells significantly,and increase the chemotherapy sensitivity to gemcitabine.     

靶向Survivin的siRNA联合吉西他滨抑制胰腺癌细胞增殖

Objective To construct the siRNA eukaryotic expression vector targeting Survivin gene, and investigate the chemotherapy sensitivity of pancreatic cancer line Panc-1 treated by gemcitabine. Methods The siRNA eukaryotic expression vector targeting Survivin gene was constructed. Panc-1 cells were transfected with negative control vector or siRNA vector and selected by G418, and the cell growth curve was drawn. The expression of Survivin mRNA and protein was detected by RT-PCR and Western blot respectively. Panc-1 cells or transfected cells were treated with gemcitabine for 24 h,and then the growth inhibition rate was measured by MTT assay, and cell apeptosis rate was measured by flow cytometry. Results The result of endonuclease digestion and DNA sequencing revealed that the recombinant plasmid psiRNA-Survivin was constructed successfully. Survivin mRNA and protein levels were reduced by 79.2% and 83.6% respectively in stably transfected Panc-1 cells as compared with control group, and the cell growth curve was much smoother, and the growth inhibition rate [ ( 24.6±4.5 ) % / (38.7±5.2 ) % ] and apoptosis rate of these cells [ ( 16.7±2.5 ) %/( 26.8±3.4 ) % ] were significantly increased after treatment by gemcitabine (P < 0.05 ). Conclusion The constructed siRNA eukaryotie expression vector targeting Survivin could decrease the Survivin expression,inhibit the growth of Panc-1 cells significantly,and increase the chemotherapy sensitivity to gemcitabine.     

Green fluorescent protein as marker in chondrocytes overexpressing human insulin-like growth factor-1 for repair of articular cartilage defects in rabbits

Objective:To label the primary articular chondrocytes overexpressing human insulin-like growth factor (hIGF-1) with green fluorescent protein (GFP) for repair of articular cartilage defects in rabbits. Methods: GFP cDNA was inserted into pcDNA3. 1-hIGF-1 to label the expression vector. The recombinant vector, pcGI, a mammalian expression vector with multiple cloning sites under two respective cytomegalovirus promoters/enhancers, was transfected into the primary articular chondrocytes with the help of lipofectamine. After the positive cell clones were selected by G418, G418-resistant chondrocytes were cultured in medium for 4 weeks. The stable expression of hIGF-1 in the articular chondrocytes was determined by in situ hybridization and immunocytochemical analysis and the GFP was confirmed under a fluorescence microscope. Methyl thiazolyl tetrazolium ( MTT) and flow cytometer methods were employed to determine the effect of transfection on proliferation of chondrocytes. Gray value was used to analyze quantitatively the expression of type II collagen. Results: The expression of hIGF-1 and GFP was confirmed in transfected chondrocytes by in situ hybridization, immunocytochemical analysis and fluorescence microscope observation. Green articular chondrocytes overexpressing hIGF-1 could expand and maintain their chondrogenic phenotypes for more than 4 weeks. After the transfection of IGF-1, the proliferation of chondrocytes was enhanced and the chondrocytes could effectively maintain the expression of typeⅡcollagen. Conclusions: The hIGF-1 eukaryotic expression vector containing GFP marker gene has been successfully constructed. GFP, which can be visualized in real time and in situ, is stably expressed in articular chondrocytes overexpressing hIGF-1. The labeled articular chondrocytes overexpressing hIGF-1 can be applied in cell-mediated gene therapy as well as for other biomedical purposes of transgenic chondrocytes.     

靶向性蛋白激酶B1和环氧合酶-2 shRNA腺病毒载体的构建和在人胃癌细胞的表达

Objective To construct a short hairpin RNA (shRNA) adenovirus vector targeting protein kinase BI (PKB1/Akt1) and cyclooxygenase-2 (COX-2) and observe their expression in human gastric carcinoma cell line SGC-7901. Methods Akt1 and COX-2 shRNA expression frames were sub-cloned to pGSadeno adenovirus vector by homologous recombination technology to construct pGSadeno-Aktl + COX-2 ( pGSadeno-A + C) vector. Furthermore after screening and amplification,recombinant ade-novirus vector was digested with Pacl and transfected into HEK293 cells. The replication adenovirus rAd5-A + C was packed and amplified in the HEK293 cells, and its titer was detected. After human SGC-7901 cells in vitro were transfected by rAd5-A + C,Akt1 and COX-2 mRNA and protein expression levels were detected by real-time PCR and Western blot respectively. Compared with rAdS-A + C,SGC-7901 and gen-eral rAd5-HK were selected as the negative controls. Results The recombinant adenovirus rAd5-A + C was constructed successfully and its titer reached 1.0 ×1010 pfu/ml. Aktl and COX-2 mRNA expression was downregulated significantly, and their ACt values ( 12.26±0.05 and 5.41±0.09 respectively ) were higher than rAd5-HK group (10.63±0.02 and 3.75 +0.08 respectively) and control group (10.57± 0.02 and 3.73±0.08 respectively) (P <0.01 ). There was no significant difference between rAd5-HK and control groups (P >0.05). Aktl and COX-2 protein expression was downregulated by 70.5% and 63.7% respectively ( P < 0.01 ) in rAd5-HK group as compared with control group ( P > 0.05 ). Conclu-sion The shRNA aclenovirus vector targeting Akt1 and COX-2 can specifically inhibit Akt1 and COX-2 expression,and this may be a new strategy in gastric carcinoma gene therapy targeting Akt1 and COX-2.     

Glial fibrillary acidic protein and neurofilament protein in medulloblastoma

Medulloblastoma is the most common primitive neuroectodermal tumor (PNET) with the potential to differentiate along glial or neuronal lines. Thirty cases of medulloblastoma were tested by the peroxidase-antiperoxidase (PAP) method with anti-GFAP serum (DAKO) and by the avidin-biotin peroxidase complex (ABC) method with 68kd subunit of anti-NF antibody. All the cases were classified into three subtypes based on these immunohistochemical findings and were analyzed in relation to clinico-pathological features. Fifteen of thirty medulloblastomas contained GFAP positive cells, seventeen showed cells reacting to NF. The reactions for both proteins were present in eight medulloblastomas (PNET-BD, bipotential differentiation). Seventeen medulloblastomas reacted to only one protein (PNET-MD, monopotential differentiation). No reaction for either was found in five cases (PNET-NOS, not otherwise specified). The two year survival rate was 12.5% for PNET-BD compared to 49.2% for PNET-MD and 53.3% for PNET-NOS. Nine variables, i.e. age, tumor stage, metastatic stage, operation, radiotherapy, chemotherapy, histology, GFAP and NF, were analyzed using Cox's proportional hazard model. This revealed that the significant factors were tumor stage (p = 0.0002), GFAP (p = 0.0008) and operation (p less than 0.05). In conclusion, GFAP is the most important histological factor for prognosis and medulloblastoma without glial differentiation has a much better prognosis than one with glial differentiation.     

Angiogenic protein therapy

Therapeutic angiogenesis, in the form of growth factor protein administration or gene therapy, has emerged as a new method of treatment for patients with severe, inoperable coronary artery disease. Improved myocardial perfusion and function after the administration of angiogenic growth factors has been demonstrated in animal models of chronic myocardial ischemia. A recent clinical study reported beneficial long-term effects of therapeutic angiogenesis using FGF-2 protein in terms of freedom from angina and myocardial perfusion on nuclear imaging and suggested that protein angiogenic therapy has the potential to extend treatment options to patients who are not optimal candidates for conventional methods of myocardial revascularization. The ultimate role that angiogenesis will play in the treatment of ischemic heart disease will, however, be determined from adequately powered, randomized, double-blind, placebo-controlled trials. It is likely that endogenous antiangiogenic influences, intrinsic lack of response of patients with severe endothelial dysfunction, and other limitations will have to be overcome before angiogenesis becomes standard therapy for the treatment of coronary artery disease.     

Plasma protein derivatives

Plasma protein derivatives produced from human plasma include albumin, blood coagulation factors, immuno globulins, haptoglobin, and c1-inactivator and have been widely used clinically. However, the HIV-tainted blood scandal in which HIV was transmitted to many Japanese patients through blood coagulation factors, must be remembered. The safety of blood products has increased since then in response to that event. Because blood products are provided by volunteer donors, there is a risk of contamination by unknown pathogens and they must be used appropriately. In addition, blood products including plasma derivatives are defined as "special biological products" and regulated by the new Medicine Act. All physicians who prescribe plasma derivatives should understand not only their clinical use but also social expectations and legal regulations.