AIM: To evaluate antihepatoma effect of antisense phosphorothioate oligodeoxyribonucleotides (S-ODNs) targeted to alpha-fetoprotein (AFP) genes in vitro and in nude mice. METHODS: AFP gene expression was examined by i...AIM: To evaluate antihepatoma effect of antisense phosphorothioate oligodeoxyribonucleotides (S-ODNs) targeted to alpha-fetoprotein (AFP) genes in vitro and in nude mice. METHODS: AFP gene expression was examined by immunocytochemical method or enzyme-linked immunosorbent assay. Effect of S-ODNs on SMMC-7721 human hepatoma cell growth in vitro was determined using microculture tetrazolium assay. In vitro antitumor activities of S-ODNs were monitored by measuring tumor weight differences in treated and control mice bearing SMMC-7721 xenografts. Induction of cell apoptosis was evaluated by fluorescence-activated cell sorter (FACS) analysis. RESULTS: Antisense S-ODN treatment led to reduced AFP gene expression. Specific antisense S-ODNs, but not control S-ODNs, inhibited the growth of hepatoma cells in vitro. In vitro, only antisense S-ODNs exhibited obvious antitumor activities. FACS analysis revealed that the growth inhibition by antisense S-ODNs was associated with their cell apoptosis induction. CONCLUSION: Antisense S-ODNs targeted to AFP genes inhibit the growth of human hepatoma cells and solid hepatoma, which is related to their cell apoptosis induction.展开更多
ζ-Carotene desaturase(ZDS)is an important enzyme in carotenoid biosynthesis.Here,the Brassica oleracea var.alboglabra ZDS(Boa ZDS)gene was cloned from Chinese kale via reverse transcription-polymerase chain reaction(...ζ-Carotene desaturase(ZDS)is an important enzyme in carotenoid biosynthesis.Here,the Brassica oleracea var.alboglabra ZDS(Boa ZDS)gene was cloned from Chinese kale via reverse transcription-polymerase chain reaction(RT-PCR)and deposited in Gen Bank(accession number KY662297).The Boa ZDS gene contains an open reading frame of 1 686 bp that encodes a 561-amino acid protein.Sequence analysis indicates that the ZDS protein is apparently conserved during plant evolution and is most closely related to B.oleracea var.capitata and B.rapa.The promoter sequence of the Boa ZDS gene was predicted to harbor several cis-acting elements that are related to light and phytohormone responses.Semiquantitative RT-PCR analysis showed that Boa ZDS expression varied among different developmental stages and organs.Relative ZDS expression remained stable during germination and seedling stages and rapidly increased at the mature leaf stage.The leaves showed the highest ZDS expression levels compared to the other organs.ZDS expression decreased in all flower tissues during blooming.The fused protein of Boa ZDS was obtained by prokaryotic expression.Heterologous expression of Boa ZDS in Escherichia coli confirmed that Boa ZDS encodes a functionalζ-carotene desaturase that increases β-carotene accumulation in E.coli cells harboring a β-carotene-producing plasmid.The findings of the present study provide a molecular basis for the elucidation of ZDS gene function in Chinese kale.展开更多
The methylotrophic yeast Pichia pastoris(a.k.a.Komagataella phaffii)is one of the most commonly used hosts for industrial production of recombinant proteins.As a non-conventional yeast,P.pastoris has unique biological...The methylotrophic yeast Pichia pastoris(a.k.a.Komagataella phaffii)is one of the most commonly used hosts for industrial production of recombinant proteins.As a non-conventional yeast,P.pastoris has unique biological characteristics and its expression system has been well developed.With the advances in synthetic biology,more efforts have been devoted to developing P.pastoris into a chassis for the production of various high-value compounds,such as natural products.This review begins with the introduction of synthetic biology tools for the engineering of P.pastoris,including vectors,promoters,and terminators for heterologous gene expression as well as Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR-associated System(CRISPR/Cas)for genome editing.This review is then followed by examples of the production of value-added natural products in metabolically engineered P.pastoris strains.Finally,challenges and outlooks in developing P.pastoris as a synthetic biology chassis are prospected.展开更多
基金Supported by the National Postdoctoral Science Foundation of China,No.199711.
文摘AIM: To evaluate antihepatoma effect of antisense phosphorothioate oligodeoxyribonucleotides (S-ODNs) targeted to alpha-fetoprotein (AFP) genes in vitro and in nude mice. METHODS: AFP gene expression was examined by immunocytochemical method or enzyme-linked immunosorbent assay. Effect of S-ODNs on SMMC-7721 human hepatoma cell growth in vitro was determined using microculture tetrazolium assay. In vitro antitumor activities of S-ODNs were monitored by measuring tumor weight differences in treated and control mice bearing SMMC-7721 xenografts. Induction of cell apoptosis was evaluated by fluorescence-activated cell sorter (FACS) analysis. RESULTS: Antisense S-ODN treatment led to reduced AFP gene expression. Specific antisense S-ODNs, but not control S-ODNs, inhibited the growth of hepatoma cells in vitro. In vitro, only antisense S-ODNs exhibited obvious antitumor activities. FACS analysis revealed that the growth inhibition by antisense S-ODNs was associated with their cell apoptosis induction. CONCLUSION: Antisense S-ODNs targeted to AFP genes inhibit the growth of human hepatoma cells and solid hepatoma, which is related to their cell apoptosis induction.
基金supported by National Natural Science Foundation of China(31500247)Key Project of Department of Education of Sichuan Province(14ZA0016)Natural Science Foundation of Zhejiang Province(LZ15C150001)
文摘ζ-Carotene desaturase(ZDS)is an important enzyme in carotenoid biosynthesis.Here,the Brassica oleracea var.alboglabra ZDS(Boa ZDS)gene was cloned from Chinese kale via reverse transcription-polymerase chain reaction(RT-PCR)and deposited in Gen Bank(accession number KY662297).The Boa ZDS gene contains an open reading frame of 1 686 bp that encodes a 561-amino acid protein.Sequence analysis indicates that the ZDS protein is apparently conserved during plant evolution and is most closely related to B.oleracea var.capitata and B.rapa.The promoter sequence of the Boa ZDS gene was predicted to harbor several cis-acting elements that are related to light and phytohormone responses.Semiquantitative RT-PCR analysis showed that Boa ZDS expression varied among different developmental stages and organs.Relative ZDS expression remained stable during germination and seedling stages and rapidly increased at the mature leaf stage.The leaves showed the highest ZDS expression levels compared to the other organs.ZDS expression decreased in all flower tissues during blooming.The fused protein of Boa ZDS was obtained by prokaryotic expression.Heterologous expression of Boa ZDS in Escherichia coli confirmed that Boa ZDS encodes a functionalζ-carotene desaturase that increases β-carotene accumulation in E.coli cells harboring a β-carotene-producing plasmid.The findings of the present study provide a molecular basis for the elucidation of ZDS gene function in Chinese kale.
基金supported by the National Key Research and Development Program of China(2018YFA0901800)the Natural Science Foundation of China(21808199)the Natural Science Foundation of Zhejiang Province(LR20B060003).
文摘The methylotrophic yeast Pichia pastoris(a.k.a.Komagataella phaffii)is one of the most commonly used hosts for industrial production of recombinant proteins.As a non-conventional yeast,P.pastoris has unique biological characteristics and its expression system has been well developed.With the advances in synthetic biology,more efforts have been devoted to developing P.pastoris into a chassis for the production of various high-value compounds,such as natural products.This review begins with the introduction of synthetic biology tools for the engineering of P.pastoris,including vectors,promoters,and terminators for heterologous gene expression as well as Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR-associated System(CRISPR/Cas)for genome editing.This review is then followed by examples of the production of value-added natural products in metabolically engineered P.pastoris strains.Finally,challenges and outlooks in developing P.pastoris as a synthetic biology chassis are prospected.
