AIM: To identify the precise location of putative tumor suppressor genes (TSGs) on the short arm of chromo- some 8 in patients with hepatocellular carcinoma (HCC). METHODS: We used 16 microsatellite markers informativ...AIM: To identify the precise location of putative tumor suppressor genes (TSGs) on the short arm of chromo- some 8 in patients with hepatocellular carcinoma (HCC). METHODS: We used 16 microsatellite markers informative in Japanese patients, which were selected from 61 pub- lished markers, on 8p, to analyze the frequency of loss of heterozygosity (LOH) in each region in 33 cases (56 lesions) of HCC. RESULTS: The frequency of LOH at 8p23.2-21 with at least one marker was 63% (20/32) in the informative cases. More specifically, the frequency of LOH at 8p23.2, 8p23.1, 8p22, and 8p21 was 6%, 52%, 47%, and 13% in HCC cases. The LOH was significantly more frequent at 8p23.1 and 8p22 than the average (52% vs 22%, P = 0.0008; and 47% vs 22%, P = 0.004, respectively) or others sites, such as 8p23.2 (52% vs 6%, P = 0.003; 47% vs 22%, P = 0.004) and 8p21 (52% vs 13%, P = 0.001; 47% vs 13%, P = 0.005) in liver cancer on the basis of cases. Notably, LOH frequency was significantly higher at D8S277, D8S503, D8S1130, D8S552, D8S254 and D8S258 than at the other sites. However, no allelic loss was detected at any marker on 8p in the lesions of nontumor liver tissues. CONCLUSION: Deletion of 8p, especially the loss of 8p23.1-22, is an important event in the initiation or promotion of HCC. Our results should be useful in identi- fying critical genes that might lie at 8p23.1-22.展开更多
Oxidation and reduction of some amino acids are one of the molecular mechanisms for regulating the function of proteins. The oxidation of methionine (Met) to methionine sulfoxide (Met(O)) results in decreasing or loss...Oxidation and reduction of some amino acids are one of the molecular mechanisms for regulating the function of proteins. The oxidation of methionine (Met) to methionine sulfoxide (Met(O)) results in decreasing or loss of the biological activity of related proteins. It was found that peptide methionine sulfoxide reductase (msrA) can reduce Met(O) to Met and therefore restored the biological function of the oxidized proteins. To reveal the methionine oxidation-reduction mechanism in human body, in this study, the cDNA sequence of bovine msrA was used as an information-probe to screen the human EST database. Based on a contig assembled from homologous ESTs, a 1 256-bp human MSRA cDNA was cloned from several human cDNA libraries. The cDNA contains an open reading frame (ORF) of 705 bp in length, which encodes 235 amino acid residues. Homology comparison revealed that human MSRA shares 88% and 61% identities with bovine and Escherichia coli msrA protein respectively. Expression pattern analysis revealed a展开更多
文摘AIM: To identify the precise location of putative tumor suppressor genes (TSGs) on the short arm of chromo- some 8 in patients with hepatocellular carcinoma (HCC). METHODS: We used 16 microsatellite markers informative in Japanese patients, which were selected from 61 pub- lished markers, on 8p, to analyze the frequency of loss of heterozygosity (LOH) in each region in 33 cases (56 lesions) of HCC. RESULTS: The frequency of LOH at 8p23.2-21 with at least one marker was 63% (20/32) in the informative cases. More specifically, the frequency of LOH at 8p23.2, 8p23.1, 8p22, and 8p21 was 6%, 52%, 47%, and 13% in HCC cases. The LOH was significantly more frequent at 8p23.1 and 8p22 than the average (52% vs 22%, P = 0.0008; and 47% vs 22%, P = 0.004, respectively) or others sites, such as 8p23.2 (52% vs 6%, P = 0.003; 47% vs 22%, P = 0.004) and 8p21 (52% vs 13%, P = 0.001; 47% vs 13%, P = 0.005) in liver cancer on the basis of cases. Notably, LOH frequency was significantly higher at D8S277, D8S503, D8S1130, D8S552, D8S254 and D8S258 than at the other sites. However, no allelic loss was detected at any marker on 8p in the lesions of nontumor liver tissues. CONCLUSION: Deletion of 8p, especially the loss of 8p23.1-22, is an important event in the initiation or promotion of HCC. Our results should be useful in identi- fying critical genes that might lie at 8p23.1-22.
文摘Oxidation and reduction of some amino acids are one of the molecular mechanisms for regulating the function of proteins. The oxidation of methionine (Met) to methionine sulfoxide (Met(O)) results in decreasing or loss of the biological activity of related proteins. It was found that peptide methionine sulfoxide reductase (msrA) can reduce Met(O) to Met and therefore restored the biological function of the oxidized proteins. To reveal the methionine oxidation-reduction mechanism in human body, in this study, the cDNA sequence of bovine msrA was used as an information-probe to screen the human EST database. Based on a contig assembled from homologous ESTs, a 1 256-bp human MSRA cDNA was cloned from several human cDNA libraries. The cDNA contains an open reading frame (ORF) of 705 bp in length, which encodes 235 amino acid residues. Homology comparison revealed that human MSRA shares 88% and 61% identities with bovine and Escherichia coli msrA protein respectively. Expression pattern analysis revealed a
