p53 polymorphism and p21WAF1/CIP1 haplotype in the intestinal gastric cancer and the precancerous lesions.

The development of intestinal gastric carcinoma involves several precancerous stages. The environmental factor plays an important role in gastric carcinogenesis, while the host's genetic makeup may influence the susceptibility to cancer. In this study we investigated correlations of the p53 variations at codon 72 and p21(WAF1/CIP1) haplotype with the risk of intestinal gastric carcinoma. Forty-eight intestinal gastric carcinoma cases (GC), 96 chronic atrophic gastritis (CAG), 96 intestinal metaplasia (IM) and 96 dysplasia (DYS) controls were enrolled in this study. The p53 codon 72 proline allele carriers were found to be more susceptible to progress to GC than to IM (OR = 2.22, 95%CI = 1.05-4.70, P = 0.038). Patients carrying homozygous p21(WAF1/CIP1) haplotype A, which contains the serine at codon 31, the cytidine at the 16th base of the second intron, and the cytidine at the 70th base of the exon 3 were more prone to develop GC than to reach the IM or DYS stage (IM versus GC, OR = 3.35, 95%CI = 1.11-10.15; DYS versus GC, OR = 3.27, 95%CI = 1.09-9.80, P = 0.035). The combination of p53 codon 72 variation with the p21(WAF1/CIP1) haplotype further distinguished the risk of GC from IM precancerous lesion (OR = 9.31, 95% CI = 1.77-48.85, P = 0.08). These results suggest that p53 and/or p21(WAF1/CIP1) genotype may influence the progression during gastric tumorigenesis.

[Analysis on the SARS-CoV genome of PUMC01 isolate].

OBJECTIVE: To perform variation and phylogenetics analysis on the SARS-CoV genome sequence (PUMC01) isolated in the Peking Union Medical College Hospital. METHODS: The cDNA library of SARS-CoV (PUMC01 isolate) was constructed by means of random-priming strategy. Random selected plasmid was sequenced and the genome sequence of SARS-CoV-PUMC01 was assembled by conventional methods (The Genebank Accession No. of SARS-CoV-PUMC01 is AY350750). The variation and phylogenetics analysis were performed by comparing the PUMC01 sequence with other SARS-CoV isolates. RESULTS: Ten variation sites were found by comparing PUMC01 isolate with Tor2 and Urbani isolates. In phylogenetic analysis of 18 SARS-CoV isolates, two classes were observed and there is different differential time between these two classes and the different isolates in each class. CONCLUSIONS: The evidence of phylogenetic analysis of different SARS-CoV isolates from different region is instructive for understanding the clinical relations between the different isolates and the transmission chain of SARS-CoV.

[Association of child absence epilepsy with T-STAR gene].

OBJECTIVE: To investigate the Association of child absence epilepsy with T-STAR gene. METHODS: PCR was conducted on the DNA of peripheral blood white cells from 48 children with child absence epilepsy (CAE), 47 male and 49 female, aged 2.9 approximately 14, of Han nationality in Northern China and 48 healthy children in the same area to amplify the exons of T-STAR gene The PCR products underwent sequencing to identify the possible mutations. RESULTS: No mutation was found in the exons of the T-STAR gene, however, 3 single nucleotide polymorphisms (SNPs) were found. A case-control study was carried out, using SNP1 and SNP2. There was no significant difference in genotype frequency of the 2 SNPs between the CAE group and control group (SNA1: chi(2) = 2.965, df = 1, P = 0.085; SNP2: chi(2) = 2.965, df = 1, P = 0.085). There was no significant difference in allele frequency of the 2 SNPs between the CAE group and control group too (SNA1: chi(2) = 3.185, df = 2, P = 0.203; SNP2: chi(2) = 3.185, df = 2, P = 0.203). CONCLUSION: T-STAR may not be a susceptibility gene for CAE in Chinese populations.

Esophageal cancer in Chinese population: no polymorphism in codon 149 of P21(Waf1/Cip1) cyclin dependent kinase gene.

It has recently been suggested that people of the Indian population who carried the codon 149 polymorphism (GAT-->GGT) of P21(Waf1/Cip1) gene were more susceptible to esophageal cancer and oral cancer than the individuals without that polymorphism. Since esophageal cancer is a high incident neoplasm in China, we analysed the same codon of P21(Waf1/Cip1) in the Chinese population. Blood samples from 80 esophageal cancer patients and 80 normal blood donors were collected for DNA extraction. Methods of Polymerase Chain Reaction (PCR) and direct sequencing were used for detection of the polymorphism in codon 149 of P21(Waf1/Cip1). Bioinformatics analysis was also thoroughly performed for this gene. No polymorphism was found in all samples tested. Bioinformatics analysis revealed that the so-called polymorphism of codon 149 reported previously was a wrong one. In conclusion, no polymorphism exists in codon 149 of P21(Waf1/Cip1). It is not appropriate to use it as a susceptible site of the gene in cancer study.

[Annotation of complete genomic sequence of 3p24-p25 478 kb of human DNA].

OBJECTIVE: To annotate the human genome 3p24-p25 478 kb complete sequence. METHODS: The protein-coding genes in the genomic sequence were identified by using ab initio gene finding, homology-based similarity database searching and all or partial mRNA aligning with genomic sequence, and the content feature of the genomic sequence were analyzed by using EMBOSS package. RESULTS: Two known genes SLC6A1 and SLC6A11 were identified; as well as the GC content of this genomic sequence was 47% and 3 putative CpG islands were predicted in the genomic sequence, located in 130,685-131,516 bp, 307,090-307,870 bp and 415,585-416,308 bp, respectively. CONCLUSIONS: The methods, as mentioned above, might be used for annotating the biological information in the genomic sequence, such as gene structure, GC content, CpG island.