A monoclonal antibody, LC-1, recognizing lung cancer associated common antigens was obtained in authors’ laboratory. Its single chain Fv fragment (ScFv) named LC-1 ScFv was constructed based on recombinant phage disp...A monoclonal antibody, LC-1, recognizing lung cancer associated common antigens was obtained in authors’ laboratory. Its single chain Fv fragment (ScFv) named LC-1 ScFv was constructed based on recombinant phage displayed techniques. For expression on cell membrane, LC-1 ScFv was cloned into pDisplay vector, which directed the cloned gene to express as cell membrane bound protein. The resulting plasmid was sequenced and then introduced by the lipofectin method into a lung adenocarcinoma cell line SPC-A-1. G418 resistant cells were obtained by G418 selection. After transfection, LC-1 ScFv expression was observed by Western blot analysis and the expression of cognate antigens was down-regulated as shown in ELISA assay. SPC-A-1-pDisplay-ScFv cells grew in vitro at lower speed than the control intact cells and the cells transfected with vacant vector. Flow cytometry analysis detected a substantial increase in G1 phase and decrease in S phase in population of SPC-A-1-pDisplay-ScFv cells compared to SPC-A -1 and SPC-A1-pDisplay cells. Semi-quantitative RT-PCR analysis showed that c-myc expression was down-regulated in SPC-A-1-pDisplay-ScFv cells. It seems that the antigens recognized by LC-1 may be in some way involved in a growth stimulating pathway and the antibody blocking of the function of the antigens shut down the pathway and thus down-regulate the expression of c-myc and growth of the cells.展开更多
目的建立并确证一种快速、灵敏、高效的测定生物样品中SphK1活性的液质联用(LC-MS/MS)分析方法。方法采用C17-Sph作为底物,通过测定产物C17-S1P的生成量来评价SphK1的活性进行体外酶促反应。终止反应后,生物样品经液-液萃取,真空干燥,复...目的建立并确证一种快速、灵敏、高效的测定生物样品中SphK1活性的液质联用(LC-MS/MS)分析方法。方法采用C17-Sph作为底物,通过测定产物C17-S1P的生成量来评价SphK1的活性进行体外酶促反应。终止反应后,生物样品经液-液萃取,真空干燥,复溶,进行LC-MS/MS分析。通过测定产物C17-S1P的生成量来评价SphK1的活性。结果 C17-S1P标准曲线的线性范围为10～1 000 ng mL-1,相关系数r2>0.998,最低检测限(LLOQ)为10 ng mL-1。HEK293细胞转染了野生型SphK(SphKWT)后,SphK1活性显著增加。相反HEK293细胞转染了突变型SphK(SphKG82D)后,SphK1活性接近正常水平。结论该方法能够灵敏快速地测量SphK1活性,为研究SphK1信号通路及其相应靶标药物提供了有效的分析手段。展开更多
基金This work was supperted by Sciense and Tech-nology Promoting FOundation of Shanghai No.984419071.
文摘A monoclonal antibody, LC-1, recognizing lung cancer associated common antigens was obtained in authors’ laboratory. Its single chain Fv fragment (ScFv) named LC-1 ScFv was constructed based on recombinant phage displayed techniques. For expression on cell membrane, LC-1 ScFv was cloned into pDisplay vector, which directed the cloned gene to express as cell membrane bound protein. The resulting plasmid was sequenced and then introduced by the lipofectin method into a lung adenocarcinoma cell line SPC-A-1. G418 resistant cells were obtained by G418 selection. After transfection, LC-1 ScFv expression was observed by Western blot analysis and the expression of cognate antigens was down-regulated as shown in ELISA assay. SPC-A-1-pDisplay-ScFv cells grew in vitro at lower speed than the control intact cells and the cells transfected with vacant vector. Flow cytometry analysis detected a substantial increase in G1 phase and decrease in S phase in population of SPC-A-1-pDisplay-ScFv cells compared to SPC-A -1 and SPC-A1-pDisplay cells. Semi-quantitative RT-PCR analysis showed that c-myc expression was down-regulated in SPC-A-1-pDisplay-ScFv cells. It seems that the antigens recognized by LC-1 may be in some way involved in a growth stimulating pathway and the antibody blocking of the function of the antigens shut down the pathway and thus down-regulate the expression of c-myc and growth of the cells.
文摘目的建立并确证一种快速、灵敏、高效的测定生物样品中SphK1活性的液质联用(LC-MS/MS)分析方法。方法采用C17-Sph作为底物,通过测定产物C17-S1P的生成量来评价SphK1的活性进行体外酶促反应。终止反应后,生物样品经液-液萃取,真空干燥,复溶,进行LC-MS/MS分析。通过测定产物C17-S1P的生成量来评价SphK1的活性。结果 C17-S1P标准曲线的线性范围为10～1 000 ng mL-1,相关系数r2>0.998,最低检测限(LLOQ)为10 ng mL-1。HEK293细胞转染了野生型SphK(SphKWT)后,SphK1活性显著增加。相反HEK293细胞转染了突变型SphK(SphKG82D)后,SphK1活性接近正常水平。结论该方法能够灵敏快速地测量SphK1活性,为研究SphK1信号通路及其相应靶标药物提供了有效的分析手段。
