O6-methylguanine-DNA methyltransferase (MGMT) plays an important role in repairing alkylated DNA. MGMT activity as well as cellular sensitivity to 1- ( 4- amino- 2-methyl-5-pyrimidinyl) methyl-3- ( 2-chloroethyl)-3-ni...O6-methylguanine-DNA methyltransferase (MGMT) plays an important role in repairing alkylated DNA. MGMT activity as well as cellular sensitivity to 1- ( 4- amino- 2-methyl-5-pyrimidinyl) methyl-3- ( 2-chloroethyl)-3-nitrosourea (ACNU) of 20 Chinese tumor cell strains were assayed. A linear response between MGMT activity and ACNU sensitivity (D10) was observed. The lower the MGMT activity In the cells, the more the sensitivity to ACNU killing. It suggested that assay of MGMT activity in tumor biopsy could be used as a guide to predict the effectiveness of ACNU treatment in chemotherapy of human cancer.展开更多
To elucidate the structures of SLA-DR(swine leukocyte antigen DR)genes of three Chinese pig strains (Gz,Bm and Yn),the SLA-DRA and SLA-DRB cDNA were amplified by RT-PCR and subjected to determine the sequences.The who...To elucidate the structures of SLA-DR(swine leukocyte antigen DR)genes of three Chinese pig strains (Gz,Bm and Yn),the SLA-DRA and SLA-DRB cDNA were amplified by RT-PCR and subjected to determine the sequences.The whole structures of SLA-DRA alleles are identical among three strains,consisting of 759 nucleotides including an open reading frame(ORF),and are shared with those reported from NIH minipigs SLA-DRA^c and SLA-DRA^d.The same length of the ORF-containing SLA-DRB genes of three Chinese pig strains was also identified.They are composed of 801 nucleotides encoding a xenogeneic antigen molecule of 266 amino acid residues.The nucleotide sequences of the SLA-DRB genes,however,are different when compared either among the three strains or with the published data of SLA-DRB sequences,which allowed our novel SLA-DRB alleles receiving their accession numbers AY102479,AY102480 and AY102481 from the GenBank.This study further reveals that the phylogenic homologies of MHC DR or DR-like genes in structures of nucleotides and deduced amino acids between Chinese pigs(SLA)and human(HLA-DRB1*0901)are better than those between pigs and mice (H-2~b Eβ).High similarities were also found for DRα-DRβ heterodimers between Chinese pigs and human in terms of amino acids sequences critical for binding with human CD4 coreceptor molecule,which are better than those between SLA-DR and H-2 I-E molecules.A functional test indicated that,by cotransfection with Bm-DRA and Bm-DRB genes,the Bm-DR molecule-expressed L929 cells could stimulate human T cells quite well in a xenogeneic reaction in presence of human APCs.Cellular & Molecular Immunology.2004;1 (3):212-218.展开更多
文摘O6-methylguanine-DNA methyltransferase (MGMT) plays an important role in repairing alkylated DNA. MGMT activity as well as cellular sensitivity to 1- ( 4- amino- 2-methyl-5-pyrimidinyl) methyl-3- ( 2-chloroethyl)-3-nitrosourea (ACNU) of 20 Chinese tumor cell strains were assayed. A linear response between MGMT activity and ACNU sensitivity (D10) was observed. The lower the MGMT activity In the cells, the more the sensitivity to ACNU killing. It suggested that assay of MGMT activity in tumor biopsy could be used as a guide to predict the effectiveness of ACNU treatment in chemotherapy of human cancer.
基金supported by the grants from the National Natural Science Foundation of China(39993430-2)the National 863 Foundation(2003AA205009)the Foundation of Shanghai Sci-Tech Committee(04JC14085).
文摘To elucidate the structures of SLA-DR(swine leukocyte antigen DR)genes of three Chinese pig strains (Gz,Bm and Yn),the SLA-DRA and SLA-DRB cDNA were amplified by RT-PCR and subjected to determine the sequences.The whole structures of SLA-DRA alleles are identical among three strains,consisting of 759 nucleotides including an open reading frame(ORF),and are shared with those reported from NIH minipigs SLA-DRA^c and SLA-DRA^d.The same length of the ORF-containing SLA-DRB genes of three Chinese pig strains was also identified.They are composed of 801 nucleotides encoding a xenogeneic antigen molecule of 266 amino acid residues.The nucleotide sequences of the SLA-DRB genes,however,are different when compared either among the three strains or with the published data of SLA-DRB sequences,which allowed our novel SLA-DRB alleles receiving their accession numbers AY102479,AY102480 and AY102481 from the GenBank.This study further reveals that the phylogenic homologies of MHC DR or DR-like genes in structures of nucleotides and deduced amino acids between Chinese pigs(SLA)and human(HLA-DRB1*0901)are better than those between pigs and mice (H-2~b Eβ).High similarities were also found for DRα-DRβ heterodimers between Chinese pigs and human in terms of amino acids sequences critical for binding with human CD4 coreceptor molecule,which are better than those between SLA-DR and H-2 I-E molecules.A functional test indicated that,by cotransfection with Bm-DRA and Bm-DRB genes,the Bm-DR molecule-expressed L929 cells could stimulate human T cells quite well in a xenogeneic reaction in presence of human APCs.Cellular & Molecular Immunology.2004;1 (3):212-218.
