Amycolatopsis mediterranei is used for industry-scale production of rifamycin, which plays a vital role in antimyco- bacterial therapy. As the first sequenced genome of the genus Amycolatopsis, the chromosome of strai...Amycolatopsis mediterranei is used for industry-scale production of rifamycin, which plays a vital role in antimyco- bacterial therapy. As the first sequenced genome of the genus Amycolatopsis, the chromosome of strain U32 comprising 10 236 715 base pairs, is one of the largest prokaryotic genomes ever sequenced so far. Unlike the linear topology found in streptomycetes, this chromosome is circular, particularly similar to that of Saccharopolyspora erythraea and Nocardia farcinica, representing their close relationship in phylogeny and taxonomy. Although the predicted 9 228 protein-coding genes in the A. mediterranei genome shared the greatest number of orthologs with those of S. erythraea, it was unexpectedly followed by Streptomyces coelicolor rather than N. farcinica, indicating the distinct metabolic characteristics evolved via adaptation to diverse ecological niches. Besides a core region analogous to that common in streptomycetes, a novel ＇quasicore＇ with typical core characteristics is defined within the non-core region, where 21 out of the total 26 gene clusters for secondary metabolite production are located. The rifamycin biosynthesis gene cluster located in the core encodes a cytochrome P450 enzyme essential for the conversion of rifamycin SV to B, revealed by comparing to the highly homologous cluster of the rifamycin B-producing strain S699 and further confirmed by genetic complementation. The genomic information of A. mediterranei demonstrates a metabolic network orchestrated not only for extensive utilization of various carbon sources and inorganic nitrogen compounds but also for effective funneling of metabolic intermediates into the secondary antibiotic synthesis process under the control of a seemingly complex regulatory mechanism.展开更多
Acidithiobacillus caldus is one of the dominant sulfur-oxidizing bacteria in bioleaching reactors. It plays the essential role in maintaining the high acidity and oxidation of reduced inorganic sulfur compounds during...Acidithiobacillus caldus is one of the dominant sulfur-oxidizing bacteria in bioleaching reactors. It plays the essential role in maintaining the high acidity and oxidation of reduced inorganic sulfur compounds during bioleaching process. In this report, the complete genome sequence of A. caldus SM-1 is presented. The genome is composed of one chromosome （2,932,225 bp） and four plasmids （pLAtcl, pLAtc2, pLAtc3, pLAtcm） and it is rich in repetitive sequences （accounting for 11% of the total genome）, which are often associated with transposable genetic elements. In particular, twelve copies of ISAtfe and thirty-seven copies of ISAtcl have been identified, suggesting that they are active transposons in the genome. A. caldus SM-1 encodes all enzymes for the central metabolism and the assimilation of carbon compounds, among which 29 proteins/enzymes were identifiable with proteomic tools. The SM-1 fixes CO2 via the classical Calvin-Bassham--Benson （CBB） cycle, and can operate complete Embden-Meyerhof pathway （EMP）, pentose phosphate pathway （PPP）, and gluconeogenesis. It has an incomplete tricarboxylic acid cycle （TCA）. Four putative transporters involved in carbohydrate uptake were identified. Taken together, the results suggested that SM-1 was able to assimilate carbohydrates and this was subsequently confirmed experimentally because addition of 1% glucose or sucrose in basic salt medium significantly increased the growth of SM-1. It was concluded that the complete genome of SM-1 provided fundamental data for further investigation of its physiology and genetics, in addition to the carbon metabolism revealed in this study.展开更多
In this study, the 454 pyrosequencing technology was used to analyze the DNA of the Microcystis aeruginosa symbiosis system from cyanobacterial algal blooms in Taihu Lake, China. We generated 183 228 reads with an ave...In this study, the 454 pyrosequencing technology was used to analyze the DNA of the Microcystis aeruginosa symbiosis system from cyanobacterial algal blooms in Taihu Lake, China. We generated 183 228 reads with an average length of 248 bp. Running the 454 assembly algorithm over our sequences yielded 22 239 significant contigs. After excluding the M. aeruginosa sequences, we obtained 1 322 assembled contigs longer than 1 000 bp. Taxonomic analysis indicated that four kingdoms were represented in the community: Archaea (n = 9; 0.01%), Bacteria (n = 98 921; 99.6%), Eukaryota (n = 373; 3.7%), and Viruses (n = 18; 0.02%). The bacterial sequences were predominantly Alphaproteobacteria (n = 41 805; 83.3%), Betaproteobacteria (n = 5 254; 10.5%) and Gammaproteobacteria (n = 1 180; 2.4%). Gene annotations and assignment of COG (clusters of orthologous groups) functional categories indicate that a large number of the predicted genes are involved in metabolic, genetic, and environmental information processes. Our results demonstrate the extraordinary diversity of a microbial community in an ectosymbiotic system and further establish the tremendous utility of pyrosequencing.展开更多
Nested in the environment of the nucleus of the cell, the 23 sets of chromosomes that comprise the human genome function as one integrated whole system, orchestrating the expression of thousands of genes underlying th...Nested in the environment of the nucleus of the cell, the 23 sets of chromosomes that comprise the human genome function as one integrated whole system, orchestrating the expression of thousands of genes underlying the biological characteristics of the cell, individual and the species. The extraction of meaningful information from this complex data set depends crucially upon the lens through which the data are examined. We present a biophysical perspective on genomic information encoded in single nucleotide polymorphisms (SNPs), and introduce metrics for modeling information encoded in the genome. Information, like energy, is considered to be a conserved physical property of the universe. The information structured in SNPs describes the adaptation of a human population to a given environment. The maintained order measured by the information content is associated with entropies, energies, and other state variables for a dynamic system in homeostasis. “Genodynamics” characterizes the state variables for genomic populations that are stable under stochastic environmental stresses. The determination of allelic energies allows the parameterization of specific environmental influences upon individual alleles across populations. The environment drives population-based genome variation. From this vantage point, the genome is modeled as a complex, dynamic information system defined by patterns of SNP alleles and SNP haplotypes.展开更多
The human genome is a complex, dynamic information system that encodes principles of life and living systems. These principles are incorporated in the structure of human genome sequence variation and are foundational ...The human genome is a complex, dynamic information system that encodes principles of life and living systems. These principles are incorporated in the structure of human genome sequence variation and are foundational for the continuity of life and human survival. Using first principles of thermodynamics and statistical physics, we have developed analogous “genodynamic tools” for population genomic studies. Characterizing genomic information through the lens of physics has allowed us to develop energy measures for modeling genome-environment interactions. In developing biophysical parameters for genome-environment homeostasis, we found that stable genomic free energy trades off low genomic energy (genomic conservation and increased order) and high genomic entropy (genomic variation) with an environmental potential that drives the variation. In our approach, we assert that common variants are dynamic sites in the genome of a population and that the stability of whole genome adaptation is reflected in the frequencies of maintained diversity in common variants for the population in its environment. In this paper, we address the relativity of whole genome adaptation towards homeostasis. By this we mean that adaptive forces are directly reflected in the frequency distribution of alleles and/or haplotypes of the population relative to its environment, with adaptive forces driving the genome towards homeostasis. The use of genomic energy units as a biophysical metric in DNA sequence variation analyses provides new insights into the foundations of population biology and diversity. Using our biophysical tools, population differences directly reflect the adaptive influences of the environment on populations.展开更多
As a living information and communications system, the genome encodes patterns in single nucleotide polymorphisms (SNPs) reflecting human adaptation that optimizes population survival in differing environments. This p...As a living information and communications system, the genome encodes patterns in single nucleotide polymorphisms (SNPs) reflecting human adaptation that optimizes population survival in differing environments. This paper mathematically models environmentally induced adaptive forces that quantify changes in the distribution of SNP frequencies between populations. We make direct connections between biophysical methods (e.g. minimizing genomic free energy) and concepts in population genetics. Our unbiased computer program scanned a large set of SNPs in the major histocompatibility complex region and flagged an altitude dependency on a SNP associated with response to oxygen deprivation. The statistical power of our double-blind approach is demonstrated in the flagging of mathematical functional correlations of SNP information-based potentials in multiple populations with specific environmental parameters. Furthermore, our approach provides insights for new discoveries on the biology of common variants. This paper demonstrates the power of biophysical modeling of population diversity for better understanding genome-environment interactions in biological phenomenon.展开更多
Objective： To investigate the effect of insulin-like growth factor 1 receptor （IGF1R） small interfering RNA （siRNA） on the growth of human liver cancer SMMC7721 cell xenograft in nude mice. Methods： siRNA target...Objective： To investigate the effect of insulin-like growth factor 1 receptor （IGF1R） small interfering RNA （siRNA） on the growth of human liver cancer SMMC7721 cell xenograft in nude mice. Methods： siRNA targeting IGF1R was designed, and plasmid SMMC7721-1GF1R-siRNA was constructed and transfected into SMMC7721 cells （SMMC7721-1GF1R-siRNA cells）; the cells transfected with SMMC7721-1GF1 R-mutation （SMMC7721-1GF1 R-mutation cells） were used as negative con- trol, and untransfected cells as empty control. Stable cell clones were screened by G418, and transplanted into nude mice to establish cancer xenograft. Tumor growth was monitored. Tumor morphology was observed with HE staining. The expression of IGF1R protein in tumor tissues was detected by Western blot. Microvessel density （MVD） in tumor tissues was detected by SP immunohistochemistry. Cell apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling （TUNEL） assay. Results： The tumor volume was significantly smaller in SMMC7721-1GF1R-siRNA group than in SMMC7721-1GF1R-mutation and SMMC7721 groups （P 〈 0.05）. Necrosis and cell apoptosis were found in SMMC7721- IGF1R-siRNA group. The expression of IGF1R protein was significantly lower in SMMC7721-1GF1R-siRNA group than in SMMC7721-1GF1R-mutation and SMMC7721 groups （P 〈 0.05）. MVD was significantly lower in SMMC7721-1GF1R-siRNA group than in SMMC7721-1GF1R-mutation and SMMC7721 groups （11.3 ± 4.4 vs. 36.7 ± 7.6 and 28.4 ±6.5, P 〈 0.05）. The apoptosis rate of tumor cells was significantly higher in SMMC7721-1GF1R-siRNA group than in SMMC7721-1GF1R-mutation and SMMC7721 groups [（50.2 ± 6.4）% vs. （5.4 ± 1.0）% or （6.0 ±2.1）%, P〈0.05]. Conclusion： IGF1R siRNA can inhibit the growth of SMMC7721 cell xenograft in nude mice.展开更多
Posttraumatic stress disorder (PTSD) is a psychiatric disorder found in individuals afflicted by a traumatic event. Multiple environmental and genetic factors can contribute to PTSD susceptibility. Since it is rare to...Posttraumatic stress disorder (PTSD) is a psychiatric disorder found in individuals afflicted by a traumatic event. Multiple environmental and genetic factors can contribute to PTSD susceptibility. Since it is rare to find members of the same family afflicted by the same catastrophic event, it is not practical to determine PTSD susceptibility genes by a gene linkage analysis. A natural disaster, such as the 2004 Tsunami, provided us with a rare chance for a genetic analysis of PTSD. To identify SNPs associated with PTSD susceptibility, we conducted a genome-association study (GWAS) in Thai-Tsunami survivors. Initial phase of the study with 396 chronic PTSD patients and 457 controls, we identified top ninety SNPs (P -4), which were further assessed in the second phase with 395 chronic PTSD patients and 798 controls. Two SNPs (rs267950 and rs954406), were identified in the second phase, and subjected to fine mapping using a data set from both phases. SNP rs267943 showed the strongest association with PTSD susceptibility and was in complete linkage disequilibrium with SNP rs267950 with P = 6.15 × 10-8, OR = 1.46 and 95% CI = 1.19 - 1.79, reaching genome-wide significance. SNP rs267943 is located on chromosome 5 in the intron of the death-associated protein 1 (DAP1) gene and, when linked to a synthetic promoter, could regulate transcription. To our knowledge, this is the first GWAS for PTSD susceptibility in an Asian population which could provide an important insight into the genetic contribution of PTSD and may lead to new treatment strategies for PTSD.展开更多
A crucial step for understanding human evolution is to identify the genomic changes that occurred during primate evolution,thus allowing investigators to reconstruct the ancestral states preceding the human condition....A crucial step for understanding human evolution is to identify the genomic changes that occurred during primate evolution,thus allowing investigators to reconstruct the ancestral states preceding the human condition.In the past several decades,the primate clade has been a research focus in genome sequencing due to its unique phylogenetic position and key importance.展开更多
Gastric cancer is the fourth most common cancer in the world and the second leading cause of cancer-related death. More than 80% of diagnoses occur at the middle to late stage of the disease, highlighting an urgent ne...Gastric cancer is the fourth most common cancer in the world and the second leading cause of cancer-related death. More than 80% of diagnoses occur at the middle to late stage of the disease, highlighting an urgent need for novel biomarkers detectable at earlier stages. Recently, aberrantly expressed microRNAs (miRNAs) have received a great deal of attention as potential sensitive and accurate biomarkers for cancer diagnosis and prognosis. This review summarizes the current knowledge about potential miRNA biomarkers for gastric cancer that have been reported in the publicly available literature between 2008 and 2013. Available evidence indicates that aberrantly expressed miRNAs in gastric cancer correlate with tumorigenesis, tumor proliferation, distant metastasis and invasion. Furthermore, tissue and cancer types can be classified using miRNA expression profiles and next-generation sequencing. As miRNAs in plasma/serum are well protected from RNases, they remain stable under harsh conditions. Thus, potential functions of these circulating miRNAs can be deduced and may implicate their diagnostic value in cancer detection. Circulating miRNAs, as well as tissue miRNAs, may allow for the detection of gastric cancer at an early stage, prediction of prognosis, and monitoring of recurrence and/or lymph node metastasis. Taken together, the data suggest that the participation of miRNAs in biomarker development will enhance the sensitivity and specificity of diagnostic and prognostic tests for gastric cancer. (C) 2014 Baishideng Publishing Group Inc. All rights reserved.展开更多
Objective To investigate whether the common variants 45T/G and 276G/T in APM1 gene were associated with hypertension combined with obesity （HO） and related clinical features in Chinese Han population. Methods A case...Objective To investigate whether the common variants 45T/G and 276G/T in APM1 gene were associated with hypertension combined with obesity （HO） and related clinical features in Chinese Han population. Methods A case-control study design was applied. Common polymorphisms of 45T/G and 276G/T were genotyped by PCR product sequencing in 484 cases with HO and 502 controls with normal blood presure and BMI 〈 25. Results The genotype and allele frequencies of 45T/G, 276G/T, and haplotype defined by the two variants in cases did not differ from those in controls. The means of blood pressure, BMI and waist-hip ratio did not differ among genotypes of the two polymorphisms and haplotypes. Among lipid profiles, only serum high-density lipoprotein cholesterol （HDL-C） levels were significantly lower in T allele carders than that in non-T carriers after adjusting possible confounding factors （1.21 vs 1.32 mmol/L, P=0.0001）. Condusion Polymorphisms of 45T/G and 276G/T in APM1 gene are not associated with hypertension or obesity, or their clinical features in Chinese Han population. Common polymorphism of 45T/G might be associated with serum HDL-C levels in Chinese.展开更多
AIM:To investigate the role of hepatitis B virus (HBV) replication in the development of hepatocellular carcinoma (HCC), a nested case-control study was performed to study the relationship between HBV DNA level and ri...AIM:To investigate the role of hepatitis B virus (HBV) replication in the development of hepatocellular carcinoma (HCC), a nested case-control study was performed to study the relationship between HBV DNA level and risk of HCC. METHODS:One hundred and seventy cases of HCC and 276 control subjects free of HCC and cirrhosis were selected for this study. Serum HBV DNA level was measured using fluorescein quantitative polymerase chain reaction at study entry and the last visit. RESULTS:In a binary unconditional logistic regression analysis adjusted for age, cigarette smoking, alcohol consumption and family history of chronic liver diseases, the adjusted odds ratios (95% confidence intervals) of HCC in patients with increasing HBV DNA level were 2.834 (1.237-6.492), 48.403 (14.392-162.789), 42.252 (14.784-120.750), and 14.819 (6.992-31.411) for HBV DNA levels ≥ 104 to < 105; ≥ 105 to < 106; ≥ 106 to < 107; ≥ 107 copies/mL, respectively. Forty-six HCC cases were selected to compare the serums viral loads of HBV DNA at study entry with those at the last visit. The HBV DNA levels measured at the two time points did not differ significantly.CONCLUSION:The findings of this study provide strong longitudinal evidence of an increased risk of HCC associated with persistent elevation of serum HBV DNA level in the 104-107 range.展开更多
To elucidate the molecular pathology underlying the development of hepatocellular carcinoma (HCC), we used 41 highly polymorphic microsatellite markers to examine 55 HCC and corresponding non-tumor liver tissues on ch...To elucidate the molecular pathology underlying the development of hepatocellular carcinoma (HCC), we used 41 highly polymorphic microsatellite markers to examine 55 HCC and corresponding non-tumor liver tissues on chromosome 9, 16 and 17. Loss-of-heterozygosity (LOH) is observed with high frequency on chromosomal region 17p13 (36/55, 65%), 9p21-p23 (28/55, 51%), 16q21-q23 (27/55, 49%) in tumors. Meanwhile, microsatellite instability is rarely found in these microsatellite loci. Direct sequencing was performed to detect the tentative mutation of tumor suppressor genes in these regions: p53, MTS1/p16, and CDH1/E-cadherin. Within exon 5-9 of p53 gene, 14 out of 55 HCC specimens (24%) have somatic mutations, and nucleotide deletion of this gene is reported in HCC for the first time. Mutation in MTS1/pl6 is found only in one tumor case. We do not find mutations in CDH1/E-cadherin. Furthermore, a statistically significant correlation is present between p53 gene mutation and loss of chromosome region 16q21q23 and 9p21-p23, which indicates that synergism between p53 inactivation and deletion of 16q21-q23 and 9p21-p23 may play a role in the pathogenesis of HCC. Genetic aberration in hepatocellular展开更多
Objective To study the association of the apolipoprotein B gene polymorphisms with essential hypertension in Northern Chinese Han population. Methods XbaI and EcoRl polymorphisms of the apolipoprotein B （APOB） gene ...Objective To study the association of the apolipoprotein B gene polymorphisms with essential hypertension in Northern Chinese Han population. Methods XbaI and EcoRl polymorphisms of the apolipoprotein B （APOB） gene were genotyped by polymerase chain reaction （PCR） and restriction fragment-length polymorphism （RFLP） method in 503 unrelated hypertensive patients and 490 healthy controls recruited from international collaborative study of cardiovascular disease in Asia （InterAsia）. Results The difference in the genotypic distributions could be neglected across the groups. The prevalence of X＋ allele in healthy controls （4.8%） was less frequent in Chinese, and there was no significant difference in the frequency of the X＋ allele between cases （5.7%） and controls （P=0.38）. The observed E- allele frequencies were closely similar among groups （5.9% in cases vs 5.0% in controls, P=0.39）. Logitstic regression analyses revealed that the lack of association still persisted after adjustment of other environmental factors. Haplotype analysis showed that X-E＋ was most frequent and no haplotype could significantly contribute to essential hypertension. Conclusion The APOB gene XbaI and EcoRI polymorphisms are not associated with essential hypertension in the Northern Chinese Han population. Future studies on single nucleotide polymorphisms in larger samples are needed to further investigate the possible contribution of the APOB gene to essential hypertension.展开更多
BACKGROUND The diagnostic and economic value of carcinoembryonic antigen(CEA),carbohydrate antigen 19-9(CA19-9)and CA72-4 for gastrointestinal malignant tumors lacked evaluation in a larger scale.AIM To reassess the d...BACKGROUND The diagnostic and economic value of carcinoembryonic antigen(CEA),carbohydrate antigen 19-9(CA19-9)and CA72-4 for gastrointestinal malignant tumors lacked evaluation in a larger scale.AIM To reassess the diagnostic and economic value of the three tumor biomarkers.METHODS A retrospective analysis of all 32857 subjects who underwent CEA,CA19-9,CA72-4,gastroscopy and colonoscopy from October 2006 to May 2018 was conducted.Then,we assessed the discrimination and clinical usefulness.Total cost,cost per capita and cost-effectiveness ratios were used to evaluate the economic value of two schemes(gastrointestinal endoscopy for all people without blood tests vs both gastroscopy and colonoscopy when blood tests were positive).RESULTS The analysis of 32857 subjects showed that CEA was a qualified biomarker for colorectal cancer(CRC),while the diagnostic efficiencies of CA72-4 were catastrophic for all gastrointestinal cancers(GICs).Regarding early diagnosis,only CEA could be used for early CRC.The combination of biomarkers didn’t greatly increase the area under the curve.The economic indicators of CEA were superior to those of CA19-9,CA72-4 and any combination.At the threshold of 1.8μg/L to 10.4μg/L,all four indicators of CEA were lower than those in the scheme that conducted gastrointestinal endoscopy only.Subgroup analysis implied that the health checkup of CEA for people above 65 years old was economically valuable.CONCLUSION CEA had qualified diagnostic value for CRC and superior economic value for GICs,especially for elderly health checkup subjects.CA72-4 was not suitable as a diagnostic biomarker.展开更多
Leptospirosis is a widespread zoonotic disease caused by pathogenic spirochetes of the genus Leptospira that infects humans and a wide range of animals. By combining computational prediction and high-accuracy tandem m...Leptospirosis is a widespread zoonotic disease caused by pathogenic spirochetes of the genus Leptospira that infects humans and a wide range of animals. By combining computational prediction and high-accuracy tandem mass spectra, we revised the genome annotation of Leptospira interrogans serovar Lai, a free-living pathogenic spirochete responsible for leptospirosis, providing substantial peptide evidence for novel genes and new gene boundaries. Subsequently, we presented a high-coverage proteome analysis of protein expression and multiple posttranslational modifications （PTMs）. Approximately 64.3% of the predicted L. interrogans proteins were cataloged by detecting 2 540 proteins. Meanwhile, a profile of multiple PTMs was concurrently established, containing in total 32 phosphorylated, 46 acetylated and 155 methylated proteins. The PTM systems in the serovar Lai show unique features. Unique eukaryotic-like features of L. interrogans protein modifications were demonstrated in both phosphorylation and arginine methylation. This systematic analysis provides not only comprehensive information of high-coverage protein expression and multiple modifications in prokaryotes but also a view suggesting that the evolutionarily primitive L. interrogans shares significant similarities in protein modification systems with eukaryotes.展开更多
The goal of the Human Genome Project (HGP) is to determine a complete and high-quality sequence of the human genome. China, as one of the six member states, takes a region between 3pter and D3S3397 of the human chromo...The goal of the Human Genome Project (HGP) is to determine a complete and high-quality sequence of the human genome. China, as one of the six member states, takes a region between 3pter and D3S3397 of the human chromosome 3 as its share of this historic project, referred as “Beijing Region”. The complete sequence of this region comprises of 17.4 megabasepairs (Mb) with an average GC content of 42% and an average recombination rate of 2.14 cM/Mb. Within Beijing Region, 122 known and 20 novel genes are identified, as well as 42607 single nucleotide polymorphisms (SNPs). Comprehensive analyses also reveal: (i) gene density and GC-content of Beijing Region are in agreement with human cytogenetic maps, i.e. G-minus bands are GC-rich and of a high gene density, whereas G-plus bands are GC-poor and of a relatively low gene density; (ii) the average recombination rate within Beijing Region is rela-tively high compared with other regions of chromosome 3, with the highest recombination rate of 6.06 cM/Mb in the subtelomeric area; (iii) it is most likely that a large gene, associated with the mammary gland, may reside in the 1.1 Mb gene-poor area near the telomere; (iv) many dis-ease-related genes are genetically mapped to Beijing Region, including those associated with cancers and metabolic syndromes. All make Beijing Region an important target for in-depth mo-lecular investigations with a purpose of medical applications.展开更多
AIM: To identify genes associated with gastric pre-cancerous lesions in Helicobacter pylori (H. pylori )susceptible ethnic Malays. METHODS: Twenty-three Malay subjects with H. pylori infection and gastric precancerous...AIM: To identify genes associated with gastric pre-cancerous lesions in Helicobacter pylori (H. pylori )susceptible ethnic Malays. METHODS: Twenty-three Malay subjects with H. pylori infection and gastric precancerous lesions identified during endoscopy were included as "cases". Thirtyseven Malay subjects who were H. pylori negative and had no precancerous lesions were included as "controls". Venous blood was collected for genotyping with Affymetrix 50K Xba1 kit. Genotypes with call rates < 90% for autosomal single nucleotide polymorphisms (SNPs) were excluded. For each precancerous lesion, associated SNPs were identified from Manhattan plots, and only SNPs with a χ2 P value < 0.05 and Hardy Weinberg Equilibrium P value > 0.5 was considered as significant markers. RESULTS: Of the 23 H. pylori -positive subjects recruited, one sample was excluded from further analysis due to a low genotyping call rate. Of the 22 H. pylori positive samples, atrophic gastritis only was present in 50.0%, complete intestinal metaplasia was present in 18.25%, both incomplete intestinal metaplasia and dysplasia was present in 22.7%, and dysplasia only was present in 9.1%. SNPs rs9315542 (UFM1 gene), rs6878265 (THBS4 gene), rs1042194 (CYP2C19 gene) and rs10505799 (MGST1 gene) were significantly associated with atrophic gastritis, complete intestinal metaplasia, incomplete metaplasia with foci of dysplasia and dysplasia, respectively. Allele frequencies in "cases" vs "controls" for rs9315542, rs6878265, rs1042194 and rs10505799 were 0.4 vs 0.06, 0.6 vs 0.01, 0.6 vs 0.01 and 0.5 vs 0.02, respectively. CONCLUSION: Genetic variants possibly related to gastric precancerous lesions in ethnic Malays susceptible to H. pylori infection were identified for testing in subsequent trials.展开更多
基金This paper is dedicated to the late Professor JS Chiao, who initiated the research in China for rifamycin production employing A. mediterranei more than 30 years ago and who continued the endeavor to resolve the mechanism of the ＇nitrate stimulating effect＇ up to the last breath of his life. This work was supported by the National Natural Science Foundation of China （30830002）, the National High Technology Research and Development Program of China （2007AA021301, 2007AA021503）, and the Research Unit Fund of Li Ka Shing Institute of Health Sciences （7103506）.
文摘Amycolatopsis mediterranei is used for industry-scale production of rifamycin, which plays a vital role in antimyco- bacterial therapy. As the first sequenced genome of the genus Amycolatopsis, the chromosome of strain U32 comprising 10 236 715 base pairs, is one of the largest prokaryotic genomes ever sequenced so far. Unlike the linear topology found in streptomycetes, this chromosome is circular, particularly similar to that of Saccharopolyspora erythraea and Nocardia farcinica, representing their close relationship in phylogeny and taxonomy. Although the predicted 9 228 protein-coding genes in the A. mediterranei genome shared the greatest number of orthologs with those of S. erythraea, it was unexpectedly followed by Streptomyces coelicolor rather than N. farcinica, indicating the distinct metabolic characteristics evolved via adaptation to diverse ecological niches. Besides a core region analogous to that common in streptomycetes, a novel ＇quasicore＇ with typical core characteristics is defined within the non-core region, where 21 out of the total 26 gene clusters for secondary metabolite production are located. The rifamycin biosynthesis gene cluster located in the core encodes a cytochrome P450 enzyme essential for the conversion of rifamycin SV to B, revealed by comparing to the highly homologous cluster of the rifamycin B-producing strain S699 and further confirmed by genetic complementation. The genomic information of A. mediterranei demonstrates a metabolic network orchestrated not only for extensive utilization of various carbon sources and inorganic nitrogen compounds but also for effective funneling of metabolic intermediates into the secondary antibiotic synthesis process under the control of a seemingly complex regulatory mechanism.
基金supported by the National Science Foundation of China(No.30870039)the National Basic Research Program of China(973 Program,No.2010CB630903)
文摘Acidithiobacillus caldus is one of the dominant sulfur-oxidizing bacteria in bioleaching reactors. It plays the essential role in maintaining the high acidity and oxidation of reduced inorganic sulfur compounds during bioleaching process. In this report, the complete genome sequence of A. caldus SM-1 is presented. The genome is composed of one chromosome （2,932,225 bp） and four plasmids （pLAtcl, pLAtc2, pLAtc3, pLAtcm） and it is rich in repetitive sequences （accounting for 11% of the total genome）, which are often associated with transposable genetic elements. In particular, twelve copies of ISAtfe and thirty-seven copies of ISAtcl have been identified, suggesting that they are active transposons in the genome. A. caldus SM-1 encodes all enzymes for the central metabolism and the assimilation of carbon compounds, among which 29 proteins/enzymes were identifiable with proteomic tools. The SM-1 fixes CO2 via the classical Calvin-Bassham--Benson （CBB） cycle, and can operate complete Embden-Meyerhof pathway （EMP）, pentose phosphate pathway （PPP）, and gluconeogenesis. It has an incomplete tricarboxylic acid cycle （TCA）. Four putative transporters involved in carbohydrate uptake were identified. Taken together, the results suggested that SM-1 was able to assimilate carbohydrates and this was subsequently confirmed experimentally because addition of 1% glucose or sucrose in basic salt medium significantly increased the growth of SM-1. It was concluded that the complete genome of SM-1 provided fundamental data for further investigation of its physiology and genetics, in addition to the carbon metabolism revealed in this study.
基金Supported by the Knowledge Innovation Program of Chinese Academy of Sciences (No. KSCX2-YW-G-073)
文摘In this study, the 454 pyrosequencing technology was used to analyze the DNA of the Microcystis aeruginosa symbiosis system from cyanobacterial algal blooms in Taihu Lake, China. We generated 183 228 reads with an average length of 248 bp. Running the 454 assembly algorithm over our sequences yielded 22 239 significant contigs. After excluding the M. aeruginosa sequences, we obtained 1 322 assembled contigs longer than 1 000 bp. Taxonomic analysis indicated that four kingdoms were represented in the community: Archaea (n = 9; 0.01%), Bacteria (n = 98 921; 99.6%), Eukaryota (n = 373; 3.7%), and Viruses (n = 18; 0.02%). The bacterial sequences were predominantly Alphaproteobacteria (n = 41 805; 83.3%), Betaproteobacteria (n = 5 254; 10.5%) and Gammaproteobacteria (n = 1 180; 2.4%). Gene annotations and assignment of COG (clusters of orthologous groups) functional categories indicate that a large number of the predicted genes are involved in metabolic, genetic, and environmental information processes. Our results demonstrate the extraordinary diversity of a microbial community in an ectosymbiotic system and further establish the tremendous utility of pyrosequencing.
文摘Nested in the environment of the nucleus of the cell, the 23 sets of chromosomes that comprise the human genome function as one integrated whole system, orchestrating the expression of thousands of genes underlying the biological characteristics of the cell, individual and the species. The extraction of meaningful information from this complex data set depends crucially upon the lens through which the data are examined. We present a biophysical perspective on genomic information encoded in single nucleotide polymorphisms (SNPs), and introduce metrics for modeling information encoded in the genome. Information, like energy, is considered to be a conserved physical property of the universe. The information structured in SNPs describes the adaptation of a human population to a given environment. The maintained order measured by the information content is associated with entropies, energies, and other state variables for a dynamic system in homeostasis. “Genodynamics” characterizes the state variables for genomic populations that are stable under stochastic environmental stresses. The determination of allelic energies allows the parameterization of specific environmental influences upon individual alleles across populations. The environment drives population-based genome variation. From this vantage point, the genome is modeled as a complex, dynamic information system defined by patterns of SNP alleles and SNP haplotypes.
文摘The human genome is a complex, dynamic information system that encodes principles of life and living systems. These principles are incorporated in the structure of human genome sequence variation and are foundational for the continuity of life and human survival. Using first principles of thermodynamics and statistical physics, we have developed analogous “genodynamic tools” for population genomic studies. Characterizing genomic information through the lens of physics has allowed us to develop energy measures for modeling genome-environment interactions. In developing biophysical parameters for genome-environment homeostasis, we found that stable genomic free energy trades off low genomic energy (genomic conservation and increased order) and high genomic entropy (genomic variation) with an environmental potential that drives the variation. In our approach, we assert that common variants are dynamic sites in the genome of a population and that the stability of whole genome adaptation is reflected in the frequencies of maintained diversity in common variants for the population in its environment. In this paper, we address the relativity of whole genome adaptation towards homeostasis. By this we mean that adaptive forces are directly reflected in the frequency distribution of alleles and/or haplotypes of the population relative to its environment, with adaptive forces driving the genome towards homeostasis. The use of genomic energy units as a biophysical metric in DNA sequence variation analyses provides new insights into the foundations of population biology and diversity. Using our biophysical tools, population differences directly reflect the adaptive influences of the environment on populations.
文摘As a living information and communications system, the genome encodes patterns in single nucleotide polymorphisms (SNPs) reflecting human adaptation that optimizes population survival in differing environments. This paper mathematically models environmentally induced adaptive forces that quantify changes in the distribution of SNP frequencies between populations. We make direct connections between biophysical methods (e.g. minimizing genomic free energy) and concepts in population genetics. Our unbiased computer program scanned a large set of SNPs in the major histocompatibility complex region and flagged an altitude dependency on a SNP associated with response to oxygen deprivation. The statistical power of our double-blind approach is demonstrated in the flagging of mathematical functional correlations of SNP information-based potentials in multiple populations with specific environmental parameters. Furthermore, our approach provides insights for new discoveries on the biology of common variants. This paper demonstrates the power of biophysical modeling of population diversity for better understanding genome-environment interactions in biological phenomenon.
文摘Objective： To investigate the effect of insulin-like growth factor 1 receptor （IGF1R） small interfering RNA （siRNA） on the growth of human liver cancer SMMC7721 cell xenograft in nude mice. Methods： siRNA targeting IGF1R was designed, and plasmid SMMC7721-1GF1R-siRNA was constructed and transfected into SMMC7721 cells （SMMC7721-1GF1R-siRNA cells）; the cells transfected with SMMC7721-1GF1 R-mutation （SMMC7721-1GF1 R-mutation cells） were used as negative con- trol, and untransfected cells as empty control. Stable cell clones were screened by G418, and transplanted into nude mice to establish cancer xenograft. Tumor growth was monitored. Tumor morphology was observed with HE staining. The expression of IGF1R protein in tumor tissues was detected by Western blot. Microvessel density （MVD） in tumor tissues was detected by SP immunohistochemistry. Cell apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling （TUNEL） assay. Results： The tumor volume was significantly smaller in SMMC7721-1GF1R-siRNA group than in SMMC7721-1GF1R-mutation and SMMC7721 groups （P 〈 0.05）. Necrosis and cell apoptosis were found in SMMC7721- IGF1R-siRNA group. The expression of IGF1R protein was significantly lower in SMMC7721-1GF1R-siRNA group than in SMMC7721-1GF1R-mutation and SMMC7721 groups （P 〈 0.05）. MVD was significantly lower in SMMC7721-1GF1R-siRNA group than in SMMC7721-1GF1R-mutation and SMMC7721 groups （11.3 ± 4.4 vs. 36.7 ± 7.6 and 28.4 ±6.5, P 〈 0.05）. The apoptosis rate of tumor cells was significantly higher in SMMC7721-1GF1R-siRNA group than in SMMC7721-1GF1R-mutation and SMMC7721 groups [（50.2 ± 6.4）% vs. （5.4 ± 1.0）% or （6.0 ±2.1）%, P〈0.05]. Conclusion： IGF1R siRNA can inhibit the growth of SMMC7721 cell xenograft in nude mice.
文摘Posttraumatic stress disorder (PTSD) is a psychiatric disorder found in individuals afflicted by a traumatic event. Multiple environmental and genetic factors can contribute to PTSD susceptibility. Since it is rare to find members of the same family afflicted by the same catastrophic event, it is not practical to determine PTSD susceptibility genes by a gene linkage analysis. A natural disaster, such as the 2004 Tsunami, provided us with a rare chance for a genetic analysis of PTSD. To identify SNPs associated with PTSD susceptibility, we conducted a genome-association study (GWAS) in Thai-Tsunami survivors. Initial phase of the study with 396 chronic PTSD patients and 457 controls, we identified top ninety SNPs (P -4), which were further assessed in the second phase with 395 chronic PTSD patients and 798 controls. Two SNPs (rs267950 and rs954406), were identified in the second phase, and subjected to fine mapping using a data set from both phases. SNP rs267943 showed the strongest association with PTSD susceptibility and was in complete linkage disequilibrium with SNP rs267950 with P = 6.15 × 10-8, OR = 1.46 and 95% CI = 1.19 - 1.79, reaching genome-wide significance. SNP rs267943 is located on chromosome 5 in the intron of the death-associated protein 1 (DAP1) gene and, when linked to a synthetic promoter, could regulate transcription. To our knowledge, this is the first GWAS for PTSD susceptibility in an Asian population which could provide an important insight into the genetic contribution of PTSD and may lead to new treatment strategies for PTSD.
基金supported by the National Natural Science Foundation of China(31822048)Strategic Priority Research Program of the Chinese Academy of Sciences(XDPB17)。
文摘A crucial step for understanding human evolution is to identify the genomic changes that occurred during primate evolution,thus allowing investigators to reconstruct the ancestral states preceding the human condition.In the past several decades,the primate clade has been a research focus in genome sequencing due to its unique phylogenetic position and key importance.
基金Supported by Grants from the National Natural Science Foundation of China,No.30900745the National High-Tech Research and Development Program(863 Program),No.2012AA020103
文摘Gastric cancer is the fourth most common cancer in the world and the second leading cause of cancer-related death. More than 80% of diagnoses occur at the middle to late stage of the disease, highlighting an urgent need for novel biomarkers detectable at earlier stages. Recently, aberrantly expressed microRNAs (miRNAs) have received a great deal of attention as potential sensitive and accurate biomarkers for cancer diagnosis and prognosis. This review summarizes the current knowledge about potential miRNA biomarkers for gastric cancer that have been reported in the publicly available literature between 2008 and 2013. Available evidence indicates that aberrantly expressed miRNAs in gastric cancer correlate with tumorigenesis, tumor proliferation, distant metastasis and invasion. Furthermore, tissue and cancer types can be classified using miRNA expression profiles and next-generation sequencing. As miRNAs in plasma/serum are well protected from RNases, they remain stable under harsh conditions. Thus, potential functions of these circulating miRNAs can be deduced and may implicate their diagnostic value in cancer detection. Circulating miRNAs, as well as tissue miRNAs, may allow for the detection of gastric cancer at an early stage, prediction of prognosis, and monitoring of recurrence and/or lymph node metastasis. Taken together, the data suggest that the participation of miRNAs in biomarker development will enhance the sensitivity and specificity of diagnostic and prognostic tests for gastric cancer. (C) 2014 Baishideng Publishing Group Inc. All rights reserved.
文摘Objective To investigate whether the common variants 45T/G and 276G/T in APM1 gene were associated with hypertension combined with obesity （HO） and related clinical features in Chinese Han population. Methods A case-control study design was applied. Common polymorphisms of 45T/G and 276G/T were genotyped by PCR product sequencing in 484 cases with HO and 502 controls with normal blood presure and BMI 〈 25. Results The genotype and allele frequencies of 45T/G, 276G/T, and haplotype defined by the two variants in cases did not differ from those in controls. The means of blood pressure, BMI and waist-hip ratio did not differ among genotypes of the two polymorphisms and haplotypes. Among lipid profiles, only serum high-density lipoprotein cholesterol （HDL-C） levels were significantly lower in T allele carders than that in non-T carriers after adjusting possible confounding factors （1.21 vs 1.32 mmol/L, P=0.0001）. Condusion Polymorphisms of 45T/G and 276G/T in APM1 gene are not associated with hypertension or obesity, or their clinical features in Chinese Han population. Common polymorphism of 45T/G might be associated with serum HDL-C levels in Chinese.
基金The National High Technology Research and Development Program of China 863 Project, No. 2006AA02Z4C5
文摘AIM:To investigate the role of hepatitis B virus (HBV) replication in the development of hepatocellular carcinoma (HCC), a nested case-control study was performed to study the relationship between HBV DNA level and risk of HCC. METHODS:One hundred and seventy cases of HCC and 276 control subjects free of HCC and cirrhosis were selected for this study. Serum HBV DNA level was measured using fluorescein quantitative polymerase chain reaction at study entry and the last visit. RESULTS:In a binary unconditional logistic regression analysis adjusted for age, cigarette smoking, alcohol consumption and family history of chronic liver diseases, the adjusted odds ratios (95% confidence intervals) of HCC in patients with increasing HBV DNA level were 2.834 (1.237-6.492), 48.403 (14.392-162.789), 42.252 (14.784-120.750), and 14.819 (6.992-31.411) for HBV DNA levels ≥ 104 to < 105; ≥ 105 to < 106; ≥ 106 to < 107; ≥ 107 copies/mL, respectively. Forty-six HCC cases were selected to compare the serums viral loads of HBV DNA at study entry with those at the last visit. The HBV DNA levels measured at the two time points did not differ significantly.CONCLUSION:The findings of this study provide strong longitudinal evidence of an increased risk of HCC associated with persistent elevation of serum HBV DNA level in the 104-107 range.
基金supported by the Chinese High-Tech Program(863)Chinese Key Basic Research Project(973)the National Natural Science Foundation of China.Gratitude was extended to Prof.Zhu CHEN for his suggestion and direction of this work.
文摘To elucidate the molecular pathology underlying the development of hepatocellular carcinoma (HCC), we used 41 highly polymorphic microsatellite markers to examine 55 HCC and corresponding non-tumor liver tissues on chromosome 9, 16 and 17. Loss-of-heterozygosity (LOH) is observed with high frequency on chromosomal region 17p13 (36/55, 65%), 9p21-p23 (28/55, 51%), 16q21-q23 (27/55, 49%) in tumors. Meanwhile, microsatellite instability is rarely found in these microsatellite loci. Direct sequencing was performed to detect the tentative mutation of tumor suppressor genes in these regions: p53, MTS1/p16, and CDH1/E-cadherin. Within exon 5-9 of p53 gene, 14 out of 55 HCC specimens (24%) have somatic mutations, and nucleotide deletion of this gene is reported in HCC for the first time. Mutation in MTS1/pl6 is found only in one tumor case. We do not find mutations in CDH1/E-cadherin. Furthermore, a statistically significant correlation is present between p53 gene mutation and loss of chromosome region 16q21q23 and 9p21-p23, which indicates that synergism between p53 inactivation and deletion of 16q21-q23 and 9p21-p23 may play a role in the pathogenesis of HCC. Genetic aberration in hepatocellular
基金This work was funded by the National Basic Research Program of China (No. 2006CB503805)the Ministry of Science and Technology of The People’s Republic of China (No.2006AA02Z170,2006AA020706)Beijing Natural Science Foundation (No.7061006).
文摘Objective To study the association of the apolipoprotein B gene polymorphisms with essential hypertension in Northern Chinese Han population. Methods XbaI and EcoRl polymorphisms of the apolipoprotein B （APOB） gene were genotyped by polymerase chain reaction （PCR） and restriction fragment-length polymorphism （RFLP） method in 503 unrelated hypertensive patients and 490 healthy controls recruited from international collaborative study of cardiovascular disease in Asia （InterAsia）. Results The difference in the genotypic distributions could be neglected across the groups. The prevalence of X＋ allele in healthy controls （4.8%） was less frequent in Chinese, and there was no significant difference in the frequency of the X＋ allele between cases （5.7%） and controls （P=0.38）. The observed E- allele frequencies were closely similar among groups （5.9% in cases vs 5.0% in controls, P=0.39）. Logitstic regression analyses revealed that the lack of association still persisted after adjustment of other environmental factors. Haplotype analysis showed that X-E＋ was most frequent and no haplotype could significantly contribute to essential hypertension. Conclusion The APOB gene XbaI and EcoRI polymorphisms are not associated with essential hypertension in the Northern Chinese Han population. Future studies on single nucleotide polymorphisms in larger samples are needed to further investigate the possible contribution of the APOB gene to essential hypertension.
基金The study was reviewed and approved by the Zhongshan Hospital of Fudan University Institutional Review Board(Approval No.B2018-234).
文摘BACKGROUND The diagnostic and economic value of carcinoembryonic antigen(CEA),carbohydrate antigen 19-9(CA19-9)and CA72-4 for gastrointestinal malignant tumors lacked evaluation in a larger scale.AIM To reassess the diagnostic and economic value of the three tumor biomarkers.METHODS A retrospective analysis of all 32857 subjects who underwent CEA,CA19-9,CA72-4,gastroscopy and colonoscopy from October 2006 to May 2018 was conducted.Then,we assessed the discrimination and clinical usefulness.Total cost,cost per capita and cost-effectiveness ratios were used to evaluate the economic value of two schemes(gastrointestinal endoscopy for all people without blood tests vs both gastroscopy and colonoscopy when blood tests were positive).RESULTS The analysis of 32857 subjects showed that CEA was a qualified biomarker for colorectal cancer(CRC),while the diagnostic efficiencies of CA72-4 were catastrophic for all gastrointestinal cancers(GICs).Regarding early diagnosis,only CEA could be used for early CRC.The combination of biomarkers didn’t greatly increase the area under the curve.The economic indicators of CEA were superior to those of CA19-9,CA72-4 and any combination.At the threshold of 1.8μg/L to 10.4μg/L,all four indicators of CEA were lower than those in the scheme that conducted gastrointestinal endoscopy only.Subgroup analysis implied that the health checkup of CEA for people above 65 years old was economically valuable.CONCLUSION CEA had qualified diagnostic value for CRC and superior economic value for GICs,especially for elderly health checkup subjects.CA72-4 was not suitable as a diagnostic biomarker.
文摘Leptospirosis is a widespread zoonotic disease caused by pathogenic spirochetes of the genus Leptospira that infects humans and a wide range of animals. By combining computational prediction and high-accuracy tandem mass spectra, we revised the genome annotation of Leptospira interrogans serovar Lai, a free-living pathogenic spirochete responsible for leptospirosis, providing substantial peptide evidence for novel genes and new gene boundaries. Subsequently, we presented a high-coverage proteome analysis of protein expression and multiple posttranslational modifications （PTMs）. Approximately 64.3% of the predicted L. interrogans proteins were cataloged by detecting 2 540 proteins. Meanwhile, a profile of multiple PTMs was concurrently established, containing in total 32 phosphorylated, 46 acetylated and 155 methylated proteins. The PTM systems in the serovar Lai show unique features. Unique eukaryotic-like features of L. interrogans protein modifications were demonstrated in both phosphorylation and arginine methylation. This systematic analysis provides not only comprehensive information of high-coverage protein expression and multiple modifications in prokaryotes but also a view suggesting that the evolutionarily primitive L. interrogans shares significant similarities in protein modification systems with eukaryotes.
文摘The goal of the Human Genome Project (HGP) is to determine a complete and high-quality sequence of the human genome. China, as one of the six member states, takes a region between 3pter and D3S3397 of the human chromosome 3 as its share of this historic project, referred as “Beijing Region”. The complete sequence of this region comprises of 17.4 megabasepairs (Mb) with an average GC content of 42% and an average recombination rate of 2.14 cM/Mb. Within Beijing Region, 122 known and 20 novel genes are identified, as well as 42607 single nucleotide polymorphisms (SNPs). Comprehensive analyses also reveal: (i) gene density and GC-content of Beijing Region are in agreement with human cytogenetic maps, i.e. G-minus bands are GC-rich and of a high gene density, whereas G-plus bands are GC-poor and of a relatively low gene density; (ii) the average recombination rate within Beijing Region is rela-tively high compared with other regions of chromosome 3, with the highest recombination rate of 6.06 cM/Mb in the subtelomeric area; (iii) it is most likely that a large gene, associated with the mammary gland, may reside in the 1.1 Mb gene-poor area near the telomere; (iv) many dis-ease-related genes are genetically mapped to Beijing Region, including those associated with cancers and metabolic syndromes. All make Beijing Region an important target for in-depth mo-lecular investigations with a purpose of medical applications.
基金Supported by Fundamental Research Grant Scheme(FRGS)203/PPSP/6171121,1001/PPSP/812016 and 1001/PPSP/8122022 of Universiti Sains MalaysiaThe National Science Foundation of China grants,No.30971577and No.31171218+5 种基金the Shanghai Rising-Star Program,No.11QA1407600the Science Foundation of the Chinese Academy of Sciences(CAS)(KSCX2-EW-Q-1-11KSCX2-EW-R-01-05KSCX2-EW-J-15-05)the support of the National Program for Top-notch Young Innovative Talentsthe support of K.C. Wong Education Foundation, Hong Kong
文摘AIM: To identify genes associated with gastric pre-cancerous lesions in Helicobacter pylori (H. pylori )susceptible ethnic Malays. METHODS: Twenty-three Malay subjects with H. pylori infection and gastric precancerous lesions identified during endoscopy were included as "cases". Thirtyseven Malay subjects who were H. pylori negative and had no precancerous lesions were included as "controls". Venous blood was collected for genotyping with Affymetrix 50K Xba1 kit. Genotypes with call rates < 90% for autosomal single nucleotide polymorphisms (SNPs) were excluded. For each precancerous lesion, associated SNPs were identified from Manhattan plots, and only SNPs with a χ2 P value < 0.05 and Hardy Weinberg Equilibrium P value > 0.5 was considered as significant markers. RESULTS: Of the 23 H. pylori -positive subjects recruited, one sample was excluded from further analysis due to a low genotyping call rate. Of the 22 H. pylori positive samples, atrophic gastritis only was present in 50.0%, complete intestinal metaplasia was present in 18.25%, both incomplete intestinal metaplasia and dysplasia was present in 22.7%, and dysplasia only was present in 9.1%. SNPs rs9315542 (UFM1 gene), rs6878265 (THBS4 gene), rs1042194 (CYP2C19 gene) and rs10505799 (MGST1 gene) were significantly associated with atrophic gastritis, complete intestinal metaplasia, incomplete metaplasia with foci of dysplasia and dysplasia, respectively. Allele frequencies in "cases" vs "controls" for rs9315542, rs6878265, rs1042194 and rs10505799 were 0.4 vs 0.06, 0.6 vs 0.01, 0.6 vs 0.01 and 0.5 vs 0.02, respectively. CONCLUSION: Genetic variants possibly related to gastric precancerous lesions in ethnic Malays susceptible to H. pylori infection were identified for testing in subsequent trials.
