Polyamines play an important role in plant response to abiotic stress. S-adenosyl-l-methionine decarboxylase （SAMDC） is one of the key regulatory enzymes in the biosynthesis of polyamines. In order to better underst...Polyamines play an important role in plant response to abiotic stress. S-adenosyl-l-methionine decarboxylase （SAMDC） is one of the key regulatory enzymes in the biosynthesis of polyamines. In order to better understand the effect of regulation of polyamine biosynthesis on the tolerance of high-temperature stress in tomato, SAMDC cDNA isolated from Saccharomyces cerevisiae was introduced into tomato genome by means of Agrobacterium tumefaciens through leaf disc transformation. Transgene and expression was confirmed by Southern and Northern blot analyses, respectively. Transgenic plants expressing yeast SAMDC produced 1.7- to 2.4-fold higher levels of spermidine and spermine than wildtype plants under high temperature stress, and enhanced antioxidant enzyme activity and the protection of membrane lipid peroxidation was also observed. This subsequently improved the efficiency of CO2 assimilation and protected the plants from high temperature stress, which indicated that the transgenic tomato presented an enhanced tolerance to high temperature stress （38℃） compared with wild-type plants. Our results demonstrated clearly that increasing polyamine biosynthesis in plants may be a means of creating high temperature-tolerant germplasm.展开更多
多胺合成代谢关键酶鸟氨酸脱羧酶(ODC)和S-腺苷甲硫氨酸脱羧酶(Ado Met DC)与肿瘤的发生和转移密切相关。现有的ODC和Ado Met DC的抑制剂在临床实验中毒不良反应大或疗效不佳,将抑制剂和其他药物联用或通过计算机与实验相结合的方式开...多胺合成代谢关键酶鸟氨酸脱羧酶(ODC)和S-腺苷甲硫氨酸脱羧酶(Ado Met DC)与肿瘤的发生和转移密切相关。现有的ODC和Ado Met DC的抑制剂在临床实验中毒不良反应大或疗效不佳,将抑制剂和其他药物联用或通过计算机与实验相结合的方式开发小分子抑制剂有望为肿瘤治疗提供新的思路。展开更多
Objective：To generate recombinant adenovirus that could simultaneously express ornithine decarboxylase（ODC） and S-adenosylmethionine decarboxylase（AdoMetDC） antisenses specifically in prostate cancer cells,and ev...Objective：To generate recombinant adenovirus that could simultaneously express ornithine decarboxylase（ODC） and S-adenosylmethionine decarboxylase（AdoMetDC） antisenses specifically in prostate cancer cells,and evaluate its inhibitory effect on prostate cancer in vivo.Methods：Fragments of ODC and AdoMetDC genes were generated by PCR,cloned into the pPGL-PSES,and then recombined with pAdEasy-1 vectors in AdEasy-1 cells.Ad-PSES-ODC-AdoMetDCas virus was produced in HEK293 cells.Following transfection with Ad-PSES-ODC-AdoMetDCas,the levels of ODC or AdoMetDC were determined by RT-PCR and western blot assays.The effect of Ad-PSES-ODC-AdoMetDCas treatment on tumor formation and growth was evaluated in xenograft models of prostate cancers in vivo.Results：The plasmid pAdEasy-PSES-ODC-AdoMetDCas was successfully constructed and the recombinant Ad-PSES-ODC-AdoMetDCas adenovirus was produced.Transfection with Ad-PSES-ODC-AdoMetDCas adenovirus significantly inhibited the expression of ODC and AdoMetDC genes specifically in prostate DU145 cells,but not H1299,HT29 and HepG2 cancer cells,and disrupted the ability of DU145 cells to form solid prostate cancer in vivo.Intratumoral treatment with Ad-PSES-ODC-AdoMetDCas adenovirus significantly inhibited the growth of engrafted prostate tumors in vivo.Conclusion：The recombinant Ad-PSES-ODC-AdoMetDCas adenovirus specifically reduces the expression of both ODC and AdoMetDC genes in prostate cells and may be used for treatment of prostate cancers at the clinic.展开更多
基金Supported by the State Key Basic Research and Development Plan of China (2009CB119000)the National Natural Science Foundation of China(30571268)the Hi-Tech Research and Development Plan of China(G2006AA100108)
文摘Polyamines play an important role in plant response to abiotic stress. S-adenosyl-l-methionine decarboxylase （SAMDC） is one of the key regulatory enzymes in the biosynthesis of polyamines. In order to better understand the effect of regulation of polyamine biosynthesis on the tolerance of high-temperature stress in tomato, SAMDC cDNA isolated from Saccharomyces cerevisiae was introduced into tomato genome by means of Agrobacterium tumefaciens through leaf disc transformation. Transgene and expression was confirmed by Southern and Northern blot analyses, respectively. Transgenic plants expressing yeast SAMDC produced 1.7- to 2.4-fold higher levels of spermidine and spermine than wildtype plants under high temperature stress, and enhanced antioxidant enzyme activity and the protection of membrane lipid peroxidation was also observed. This subsequently improved the efficiency of CO2 assimilation and protected the plants from high temperature stress, which indicated that the transgenic tomato presented an enhanced tolerance to high temperature stress （38℃） compared with wild-type plants. Our results demonstrated clearly that increasing polyamine biosynthesis in plants may be a means of creating high temperature-tolerant germplasm.
基金supported by the National Natural Science Foundation of China(No.30900730)the grants from the Natural Science Foundation of Shangdong Province(No.Q2007D01)
文摘Objective：To generate recombinant adenovirus that could simultaneously express ornithine decarboxylase（ODC） and S-adenosylmethionine decarboxylase（AdoMetDC） antisenses specifically in prostate cancer cells,and evaluate its inhibitory effect on prostate cancer in vivo.Methods：Fragments of ODC and AdoMetDC genes were generated by PCR,cloned into the pPGL-PSES,and then recombined with pAdEasy-1 vectors in AdEasy-1 cells.Ad-PSES-ODC-AdoMetDCas virus was produced in HEK293 cells.Following transfection with Ad-PSES-ODC-AdoMetDCas,the levels of ODC or AdoMetDC were determined by RT-PCR and western blot assays.The effect of Ad-PSES-ODC-AdoMetDCas treatment on tumor formation and growth was evaluated in xenograft models of prostate cancers in vivo.Results：The plasmid pAdEasy-PSES-ODC-AdoMetDCas was successfully constructed and the recombinant Ad-PSES-ODC-AdoMetDCas adenovirus was produced.Transfection with Ad-PSES-ODC-AdoMetDCas adenovirus significantly inhibited the expression of ODC and AdoMetDC genes specifically in prostate DU145 cells,but not H1299,HT29 and HepG2 cancer cells,and disrupted the ability of DU145 cells to form solid prostate cancer in vivo.Intratumoral treatment with Ad-PSES-ODC-AdoMetDCas adenovirus significantly inhibited the growth of engrafted prostate tumors in vivo.Conclusion：The recombinant Ad-PSES-ODC-AdoMetDCas adenovirus specifically reduces the expression of both ODC and AdoMetDC genes in prostate cells and may be used for treatment of prostate cancers at the clinic.
