Construction of adenovirus-mediated anti-sense RNA targeting K-ras exon 1 in SW1990 cell line / 第二军医大学学报

Objective: To construct an adenovirus-mediated anti-sense RNA targeting K-ras exon 1 of SW1990 cell line and observe its effect on cell proliferation and apoptosis after transferred into SW1990 cell line. Methods: K-ras exon 1 cDNA was cloned into shuttle vector pShuttle-CMV and the resultant plasmid was confirmed by enzyme digestion and PCR. Clones with inverted insertion were selected and co-transferred into E. coli BJ5183 with an adenoviral backbone plasmid pAdEasy-1 to produce recombinant plasmid by homologous recombination. Recombinants were then selected and transfected into 293 cell line to produce recombinant adenovirus. Recombinant adenovirus production was confirmed by PCR analysis and was amplified and purified; the virus titer was determined. Ad-LacZ was used to infect SW1990 cells and the infection efficiency was observed by X-gal staining. SW1990 cells was infected with the recombinant adenovirus and their proliferation and apoptosis were determined by MTT and annexin V/PI FCM assay. Results: A 282 bp target gene fragment was acquired by PCR; the titer of recombinant adenovirus was 7.6 × 108 pfu/ml before purification by CsCl2 gradient centrifugation and 5.0 × 1910 pfu/ml after CsCl2 gradient centrifugation. When the recombinant adenovirus was at 100 MOI, the infection efficiency of SW1990 cells nearly reached 100%. The transfection of recombinant adenovirus significantly inhibited SW1990 cell proliferation (P<0.05), with a maximal inhibitory rate of 40.5% 4-5 days after infection; it also significantly increased SW1990 cell apoptosis, with the apoptotic rate being (22.54 ± 5.38) % 72 hours after infection. Conclusion: We have successfully constructed an anti-sense RNA adenovirus vector targeting K-ras exon 1 of SW1990 cell line, paving a way for the anti-sense K-ras gene therapy of pancreatic carcinoma.

Biomarcadores genotóxicos no monitoramento de estuários com diferentes níveis de contaminação utilizando peixes coletados in situ / Genotoxic biomarkers for monitoring estuarine with different levels of contamination using fish collected in situ

Algumas áreas do canal de Piaçaguera, localizado na Baixada Santista, SP-Brasil, apresenta alto nível contaminação por hidrocarbonetos policíclicos aromáticos (HPA) entre outros contaminantes nos sedimentos. O objetivo do presente estudo foi verificar diferentes biomarcadores de exposição em bile e de efeitos genotóxicos em sangue de peixes, coletados in situ, que poderiam ser utilizados como ferramenta de monitoramento. O canal de Bertioga foi selecionado como região de referência. Embora não seja uma região sem nenhuma interferência de contaminantes, os sedimentos apresentam baixos valores para HPA, metais e atividade mutagênica. A espécie Mugil curema foi selecionada por ser freqüentemente encontrada em ambas as regiões de estudo. Observamos que os peixes coletados no canal de Piaçaguera apresentaram maior porcentagem de micronúcleos e danos ao DNA (ensaio cometa) no sangue quando comparados com a região de referência. Para o teste de micronúcleo, realizamos leituras de 1000 e 4000 células/indivíduo e não foram observadas diferenças estatísticas, sugerindo que o número de 1000 células poderia ser suficiente para gerar dados confiáveis para a espécie Mugil curema. A avaliação de mutagenicidade da bile foi realizada pelo teste Salmonella/microssoma combinado à extração de bile utilizando Blue rayon (BR) com as linhagens TA98, TA100 e YG1041 com e sem S9 (ativação metabólica). As maiores respostas mutagênicas foram observadas para os peixes coletados no canal de Piaçaguera. A mutagenicidade com a linhagem YG1041 na presença de S9 foi mais elevada quando comparado à mutagenicidade observada na ausência de S9 e também em comparação com a sua linhagem parental TA98, indicando a provável presença de compostos da classe das aminas aromáticas na bile como responsáveis pelos efeitos observados. A quantificação de metabólitos equivalentes de HPA foi realizada por HPLC/fluorescência na bile bruta e embora os resultados não se correlacionem com a mutagenicidade, altos níveis também foram encontrados para os peixes coletados no canal de Piaçaguera em comparação com Bertioga. O protocolo de amplificação do gene ras para a espécie Mugil curema foi estabelecido e os genes foram seqüenciados para verificação da presença de mutações. Não foram observadas mutações nos poucos peixes analisados e mais estudos são necessários para verificar a utilização deste biomarcador. O teste de micronúcleo, ensaio cometa e análise de mutagencidade em bile extraída por Blue rayon parecem ser ferramentas biológicas adequadas para monitoramento da qualidade ambiental de estuários contaminados

Some areas of the Piaçaguera channel at Baixada Santista, SP, Brazil present high levels of polycyclic aromatic hydrocarbons (PAHs) among other contaminants in the sediment. The aim of the present study was to verify if biomarkers of exposure in bile and effect in blood of fishes collected in the field could be used as a monitoring tool. We selected Bertioga channel as a reference area. Although it is not a pristine area, the sediment presents low values of PAHs, metals and mutagenic activity. We selected the fish species Mugil curema, because they are frequently found in both areas during the entire year. We observed that the fish collected at the Piaçaguera channel showed a higher percentage of micronuclei and DNA damage (comet assay) in blood when compared to the Bertioga channel. The micronucleus readings were done in 1000 and 4000 cells/fish and no statistical difference was observed, suggesting that the number of 1000 cells would be sufficient to generate reliable data for the species Mugil curema , in the studied area. The mutagenicity of the bile was performed using the Salmonella/microsome assay combined with Blue rayon (BR) extraction with TA98, TA100 and YG1041 strains with and without rat liver S9. We observed that the mutagenic responses were higher in fish collected in Piaçaguera. The mutagenicity in YG1041 with S9 in fishes collected in the Piaçaguera channel was higher when compared to the mutagenicity observed in the absence of S9 and also higher than the response with the parental strain TA98. The results suggest that mutagenic polycyclic compounds, probably from the class of the aromatic amines are causing the observed effect. PAH metabolites-equivalent were also determined using HPLC/fluorescence in crude bile, and although the results did not correlate with the mutagenicity, higher levels were observed in fish collected in the Piaçaguera channel when compared to Bertioga. A protocol for amplification of the ras gene for the Mugil curema species was established and gene sequenced. No mutations were observed in the liver of the few fishes analyzed, and more studies are required to verify the utility of this biomarker in this fish. The micronuclei, comet assay and mutagenicity in bile extracted with blue rayon seem to be suitable biological tools to monitor the environmental quality of contaminated estuaries

Mutation of ras gene and overexpresion of PCNA as prognostic parameters in gallbladder cancer / 中国普通外科杂志

Objective To estimative the relationship between ras gene mutation,PCNA overexpression and the recurrence and prognosis of gallbladder cancer.Methods PCNA was studied by ABC immunohistology, ras gene mutation by PCR-RELP analysis.Results Histology,Nevin staging and operative methods were relevant to the prognosis of gallbladder cancer.The patient with stag IV,V gallbladder cancer had a poor prognosis;radical operations could prolong patients survival time.The mortal risk of patients with ras gene mutation was 1.62 times higher than that without ras gene mutation,with high overexpression of PCNA was 2.2 times higher than that with low expression of PCNA. Conclusions Differentiation degree, Nevin′s staging, mutation of ras gene and overexpresion of PCNA could be the prognostic factors in gallbladder cancer,and could help to select the operative procedure and to eluvate the surrival.

Construction of adenovirus-mediated anti-sense RNA targeting K-ras exon 1 in SW1990 cell line / 第二军医大学学报

Objective:To construct an adenovirus-mediated anti-sense RNA targeting K-ras exon 1 of SW1990 cell line and observe its effect on ceil proliferation and apoptosis after transferred into SW1990 cell line.Methods:K-ras exon 1 cDNA was cloned into shuttle vector pShuttle-CMV and the resultant plasmid was confirmed by enzyme digestion and PCR.Clones with inverted insertion were selected and co-transferred into E.coli BJ5183 with an adenoviral backbone plasmid pAdEasy-1 to produce recombinant plasmid by homologous recombination.Recombinants were then selected and transfected into 293 cell line to produce recombinant adenovirus.Recombinant adenovirus production was confirmed by PCR analysis and was amplified and purified;the virus titer was determined.Ad-LacZ was used to infect SW1990 cells and the infection efficiency was observed by X-gal staining.SW1990 cells was infected with the recombinant adenovirus and their proliferation and apoptosis were determined by MTT and annexin V/PI FCM assay.Results:A 282 bp target gene fragment was acquired by PCR;the titer of recombinant adenovirus was 7.6?10~8 pfu/ml before purification by CsCl_2 gradient centrifugation and 5.0?10~(10)pfu/ml after CsCl_2 gradient centrifugation.When the recombinant adenovirus was at 100 MOI,the infection efficiency of SW1990 cells nearly reached 100%.The transfection of recombinant adenovirus significantly inhibited SW1990 cell proliferation(P