Effects of DGAT1 gene on meat and carcass fatness quality in Chinese commercial cattle

Genetic parameters, genomic prediction, and identification of regulatory regions located on chromosome 14 for weight traits in Nellore cattle

This study aimed to investigate functional variants in chromosome 14 (BTA14) and its impact in genomic selection for birth weight (BW), weaning weight (WW), and yearling weight (YW) in Nellore cattle. Genetic parameter estimation and the weighted single-step genomic best linear unbiased prediction (WssGBLUP) analyses were performed. Direct additive heritability estimates were high for WW and YW, and moderate for BW. Trait-associated variants distributed across multiple regions on BTA14 were observed in the weighted single-step genome-wide association studies (WssGWAS) results, implying a polygenic genetic architecture for weight in different ages. Several genes have been found in association with the weight traits, including the CUB And Sushi multiple domains 3 (CSMD3), thyroglobulin (TG), and diacylglycerol O-acyltransferase 1 (DGAT1) genes. The variance explained per SNP was higher in six functional classes of gene regulatory regions (5UTR, CpG islands, downstream, upstream, long non-coding RNA, and transcription factor binding sites (TFBS)), highlighting their importance for weight traits in Nellore cattle. A marginal increase in accuracy was observed when the selected functional variants (SV) information was considered in the WssGBLUP method, probably because of the small number of SV available on BTA14. The identified genes, pathways, and functions contribute to a better understanding of the genetic and physiological mechanisms regulating weight traits in the Nellore breed.

Genetic Markers Related to Meat Quality Properties in Fattened HF and HF x Charolaise Steers

This study involved 45 Holstein and 60 Holstein-Charolaise steers, tailored with specific diets according to breed and rearing systems. DNA genotyping was conducted for DGAT1, LEP, SCD1, SREBF1, and TG genes to investigate their impact on carcass conformation traits, beef quality traits, and sensory quality traits. The results showed associations between the genetic variants and the analyzed traits. Specifically, DGAT1 was found to affect drip loss, meat brightness, and color saturation. The TG gene was associated with marbling and meat color. LEP influenced trim fat and pH levels, while SCD1 was linked to metabolic energy live weight gains, and pH levels. SREBF1 was related to fatness.

Differences in diacylglycerol acyltransferases expression patterns and regulation cause distinct hepatic triglyceride deposition in fish

Triglyceride (TAG) deposition in the liver is associated with metabolic disorders. In lower vertebrate, the propensity to accumulate hepatic TAG varies widely among fish species. Diacylglycerol acyltransferases (DGAT1 and DGAT2) are major enzymes for TAG synthesis. Here we show that large yellow croaker (Larimichthys crocea) has significantly higher hepatic TAG level than that in rainbow trout (Oncorhynchus mykiss) fed with same diet. Hepatic expression of DGATs genes in croaker is markedly higher compared with trout under physiological condition. Meanwhile, DGAT1 and DGAT2 in both croaker and trout are required for TAG synthesis and lipid droplet formation in vitro. Furthermore, oleic acid treatment increases DGAT1 expression in croaker hepatocytes rather than in trout and has no significant difference in DGAT2 expression in two fish species. Finally, effects of various transcription factors on croaker and trout DGAT1 promoter are studied. We find that DGAT1 is a target gene of the transcription factor CREBH in croaker rather than in trout. Overall, hepatic expression and transcriptional regulation of DGATs display significant species differences between croaker and trout with distinct hepatic triglyceride deposition, which bring new perspectives on the use of fish models for studying hepatic TAG deposition.

Identifying Genetic Architecture of Carcass and Meat Quality Traits in a Ningxiang Indigenous Pig Population

Ningxiang pig is a breed renowned for its exceptional meat quality, but it possesses suboptimal carcass traits. To elucidate the genetic architecture of meat quality and carcass traits in Ningxiang pigs, we assessed heritability and executed a genome-wide association study (GWAS) concerning carcass length, backfat thickness, meat color parameters (L.LD, a.LD, b.LD), and pH at two postmortem intervals (45 min and 24 h) within a Ningxiang pig population. Heritability estimates ranged from moderate to high (0.30~0.80) for carcass traits and from low to high (0.11~0.48) for meat quality traits. We identified 21 significant SNPs, the majority of which were situated within previously documented QTL regions. Furthermore, the GRM4 gene emerged as a pleiotropic gene that correlated with carcass length and backfat thickness. The ADGRF1, FKBP5, and PRIM2 genes were associated with carcass length, while the NIPBL gene was linked to backfat thickness. These genes hold the potential for use in selective breeding programs targeting carcass traits in Ningxiang pigs.

Acyl-CoA:diacylglycerol acyltransferase: Properties, physiological roles, metabolic engineering and intentional control

Acyl-CoA:diacylglycerol acyltransferase (DGAT, EC 2.3.1.20) catalyzes the last reaction in the acyl-CoA-dependent biosynthesis of triacylglycerol (TAG). DGAT activity resides mainly in membrane-bound DGAT1 and DGAT2 in eukaryotes and bifunctional wax ester synthase-diacylglycerol acyltransferase (WSD) in bacteria, which are all membrane-bound proteins but exhibit no sequence homology to each other. Recent studies also identified other DGAT enzymes such as the soluble DGAT3 and diacylglycerol acetyltransferase (EaDAcT), as well as enzymes with DGAT activities including defective in cuticular ridges (DCR) and steryl and phytyl ester synthases (PESs). This review comprehensively discusses research advances on DGATs in prokaryotes and eukaryotes with a focus on their biochemical properties, physiological roles, and biotechnological and therapeutic applications. The review begins with a discussion of DGAT assay methods, followed by a systematic discussion of TAG biosynthesis and the properties and physiological role of DGATs. Thereafter, the review discusses the three-dimensional structure and insights into mechanism of action of human DGAT1, and the modeled DGAT1 from Brassica napus. The review then examines metabolic engineering strategies involving manipulation of DGAT, followed by a discussion of its therapeutic applications. DGAT in relation to improvement of livestock traits is also discussed along with DGATs in various other eukaryotic organisms.

Identification of Candidate Genes Regulating Carcass Depth and Hind Leg Circumference in Simmental Beef Cattle Using Illumina Bovine Beadchip and Next-Generation Sequencing Analyses

Genome-wide association studies are a robust means of identifying candidate genes that regulate economically important traits in farm animals. The aim of this study is to identify single-nucleotide polymorphisms (SNPs) and candidate genes potentially related to carcass depth and hind leg circumference in Simmental beef cattle. We performed Illumina Bovine HD Beadchip (~670 k SNPs) and next-generation sequencing (~12 million imputed SNPs) analyses of data from 1252 beef cattle, to which we applied a linear mixed model. Using a statistical threshold (p = 0.05/number of SNPs identified) and adopting a false discovery rate (FDR), we identified many putative SNPs on different bovine chromosomes. We identified 12 candidate genes potentially annotated with the markers identified, including CDKAL1 and E2F3, related to myogenesis and skeletal muscle development. The identification of such genes in Simmental beef cattle will help breeders to understand and improve related traits, such as meat yield.

Systematic Identification and Comparison of the Expressed Profiles of lncRNAs, miRNAs, circRNAs, and mRNAs with Associated Co-Expression Networks in Pigs with Low and High Intramuscular Fat

Intramuscular fat (IMF) content is a complex trait that affects meat quality and determines pork quality. In order to explore the potential mechanisms that affect the intramuscular fat content of pigs, a Large white × Min pigs F2 resource populations were constructed, then whole-transcriptome profile analysis was carried out for five low-IMF and five high-IMF F2 individuals. In total, 218 messenger RNA (mRNAs), 213 long non-coding RNAs (lncRNAs), 18 microRNAs (miRNAs), and 59 circular RNAs (circRNAs) were found to be differentially expressed in the longissimus dorsi muscle. Gene ontology analysis and Kyoto Encyclopedia of Genes and Genomes annotations revealed that these differentially expressed (DE) genes or potential target genes (PTGs) of DE regulatory RNAs (lncRNAs, miRNAs, and circRNAs) are mainly involved in cell differentiation, fatty acid synthesis, system development, muscle fiber development, and regulating lipid metabolism. In total, 274 PTGs were found to be differentially expressed between low- and high-IMF pigs, which indicated that some DE regulatory RNAs may contribute to the deposition/metabolism of IMF by regulating their PTGs. In addition, we analyzed the quantitative trait loci (QTLs) of DE RNAs co-located in high- and low-IMF groups. A total of 97 DE regulatory RNAs could be found located in the QTLs related to IMF. Co-expression networks among different types of RNA and competing endogenous RNA (ceRNA) regulatory networks were also constructed, and some genes involved in type I diabetes mellitus were found to play an important role in the complex molecular process of intramuscular fat deposition. This study identified and analyzed some differential RNAs, regulatory RNAs, and PTGs related to IMF, and provided new insights into the study of IMF formation at the level of the genome-wide landscape.

Association of DGAT1 With Cattle, Buffalo, Goat, and Sheep Milk and Meat Production Traits

Milk fatty acids are essential for many dairy product productions, while intramuscular fat (IMF) is associated with the quality of meat. The triacylglycerols (TAGs) are the major components of IMF and milk fat. Therefore, understanding the polymorphisms and genes linked to fat synthesis is important for animal production. Identifying quantitative trait loci (QTLs) and genes associated with milk and meat production traits has been the objective of various mapping studies in the last decade. Consistently, the QTLs on chromosomes 14, 15, and 9 have been found to be associated with milk and meat production traits in cattle, goat, and buffalo and sheep, respectively. Diacylglycerol O-acyltransferase 1 (DGAT1) gene has been reported on chromosomes 14, 15, and 9 in cattle, goat, and buffalo and sheep, respectively. Being a key role in fat metabolism and TAG synthesis, the DGAT1 has obtained considerable attention especially in animal milk production. In addition to milk production, DGAT1 has also been a subject of interest in animal meat production. Several polymorphisms have been documented in DGAT1 in various animal species including cattle, buffalo, goat, and sheep for their association with milk production traits. In addition, the DGAT1 has also been studied for their role in meat production traits in cattle, sheep, and goat. However, very limited studies have been conducted in cattle for association of DGAT1 with meat production traits in cattle. Moreover, not a single study reported the association of DGAT1 with meat production traits in buffalo; thus, further studies are warranted to fulfill this huge gap. Keeping in view the important role of DGAT1 in animal production, the current review article was designed to highlight the major development and new insights on DGAT1 effect on milk and meat production traits in cattle, buffalo, sheep, and goat. Moreover, we have also highlighted the possible future contributions of DGAT1 for the studied species.

Whole-Transcriptome Analysis of Preadipocyte and Adipocyte and Construction of Regulatory Networks to Investigate Lipid Metabolism in Sheep

Many local sheep breeds in China have poor meat quality. Increasing intramuscular fat (IMF) content can significantly improve the quality of mutton. However, the molecular mechanisms of intramuscular adipocyte formation and differentiation remain unclear. This study compared differences between preadipocytes and mature adipocytes by whole-transcriptome sequencing and constructed systematically regulatory networks according to the relationship predicted among the differentially expressed RNAs (DERs). Sequencing results showed that in this process, there were 1,196, 754, 100, and 17 differentially expressed messenger RNAs (mRNAs), long non-coding RNAs (lncRNAs), microRNAs (miRNAs), and circular RNAs (circRNAs), respectively. Gene Ontology analysis showed that most DERs enriched in Cell Part, Cellular Process, Biological Regulation, and Binding terms. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis found that the DERs primarily focused on Focal adhesion, phosphoinositide 3-kinase (PI3K)-Akt, mitogen-activated protein kinase (MAPK), peroxisome proliferator-activated receptor (PPAR) signaling pathways. Forty (40) DERs were randomly selected from the core regulatory network to verify the accuracy of the sequence data. The results of qPCR showed that the DER expression trend was consistent with sequence data. Four novel promising candidate miRNAs (miR-336, miR-422, miR-578, and miR-722) played crucial roles in adipocyte differentiation, and they also participated in multiple and important regulatory networks. We verified the expression pattern of the miRNAs and related pathways’ members at five time points in the adipocyte differentiation process (0, 2, 4, 6, 8, 10 days) by qPCR, including miR-336/ACSL4/LncRNA-MSTRG71379/circRNA0002331, miR-422/FOXO4/LncRNA-MSTRG54995/circRNA0000520, miR-578/IGF1/LncRNA-MSTRG102235/circRNA0002971, and miR-722/PDK4/LncRNA-MSTRG107440/circ RNA0002909. In this study, our data provided plenty of valuable candidate DERs and regulatory networks for researching the molecular mechanisms of sheep adipocyte differentiation and will assist studies in improving the IMF.

Allelic and genotypic frequencies for loci associated with meat quality in Mexican Braunvieh cattle

The objective was to estimate allelic and genotypic frequencies for loci associated with meat quality in a Mexican population of Braunvieh cattle. Information was obtained from 300 animals genotyped with the Genomic Profile Bovine LD chip of 30K and 50K SNPs. After the final edition, including quality control, the data contained information for 12 loci of the CAPN1, CAPN3, CAPN5, CAPN14, DGAT1, DGAT2, TG, ANK1, and MADH3 genes. Allelic and genotypic frequencies and Hardy-Weinberg equilibrium were estimated with the Cervus 3.0.7 software. The studied population markers were in Hardy-Weinberg equilibrium, except for those associated with CAPN1, DGAT1, and MADH3. Frequencies higher than those reported for other breeds were found for genotypes associated with meat softness, higher marbling score, lower quantity of saturated fatty acids, and lower shear force (CAPN1 and DGAT2). There were similarities with frequencies reported for Bos taurus breeds for the CAPN3 and TG genes. For the DGAT1 and ANK1 genes, the frequencies of the desired genotypes were low. A marker for DGAT1 and another for MADH3 were monomorphic. The results of this study are encouraging in terms of the potential of the Braunvieh population studied for breeding programs aiming to increase meat quality. The breed has strengths that could be used either by crossbreeding to generate heterozygous animals or by selection to increase frequencies of valuable alleles.

Associations between gene polymorphisms and selected meat traits in cattle - A review

Maintaining a high level of beef consumption requires paying attention not only to quantitative traits but also to the quality and dietary properties of meat. Growing consumer demands do not leave producers many options for how animals are selected for breeding and animal keeping. Meat and carcass fatness quality traits, which are influenced by multiple genes, are economically important in beef cattle breeding programs. The recent availability of genome sequencing methods and many previously identified molecular markers offer new opportunities for animal breeding, including the use of molecular information in selection programs. Many gene polymorphisms have thus far been analyzed and evaluated as potential candidates for molecular markers of meat quality traits. Knowledge of these markers can be further applied to breeding programs through marker-assisted selection. In this literature review, we discuss the most promising and well-described candidates and their associations with selected beef production traits.

Identification and validation of a novel candidate gene regulating net meat weight in Simmental beef cattle based on imputed next-generation sequencing

Objectives

Genome‐wide association studies (GWAS) represent a powerful approach to detecting candidate genes for economically important traits in livestock. Our aim was to identify promising candidate muscle development genes that affect net meat weight (NMW) and validate these candidate genes in cattle.

Materials and methods

Using a next‐generation sequencing (NGS) dataset, we applied ~ 12 million imputed single nucleotide polymorphisms (SNPs) from 1,252 Simmental cattle to detect genes influencing net meat yield by way of a linear mixed model method. Haplotype and linkage disequilibrium (LD) blocks were employed to augment support for identified genes. To investigate the role of MTPN in bovine muscle development, we isolated myoblasts from the longissimus dorsi of a bovine foetus and treated the cells during proliferation, differentiation and hypertrophy.

Results

We identified one SNP (rs100670823) that exceeded our stringent significance threshold (P = 8.58 × 10⁻⁸) for a putative NMW‐related quantitative trait locus (QTL). We identified a promising candidate gene, myotrophin (MTPN), in the region around this SNP Myotrophin had a stimulatory effect on six muscle‐related markers that regulate differentiation and myoblast fusion. During hypertrophy, myotrophin promoted myotube hypertrophy and increased myotube diameters. Cell viability assay and flow cytometry showed that myotrophin inhibited myoblast proliferation.

Conclusions

The present experiments showed that myotrophin increases differentiation and hypertrophy of skeletal muscle cells, while inhibiting their proliferation. Our examination of GWAS results with in vitro biological studies provides new information regarding the potential application of myotrophin to increase meat yields in cattle and helpful information for further studies.

Identification of muscle-specific candidate genes in Simmental beef cattle using imputed next generation sequencing

Genome-wide association studies (GWAS) have commonly been used to identify candidate genes that control economically important traits in livestock. Our objective was to detect potential candidate genes associated mainly with muscle development traits related to dimension of hindquarter in cattle. A next generation sequencing (NGS) dataset to imputed to 12 million single nucleotide polymorphisms (SNPs) (from 1252 Simmental beef cattle) were used to search for genes affecting hindquarter traits using a linear, mixed model approach. We also used haplotype and linkage disequilibrium blocks to further support our identifications. We identified 202 significant SNPs in the bovine BTA4 chromosome region associated with width of hind leg, based on a stringent statistical threshold (p = 0.05/ effective number of SNPs identified). After exploring the region around these SNPs, we found candidate genes that were potentially related to the associated markers. More importantly, we identified a region of approximately 280 Kb on the BTA4 chromosome that harbored several muscle specific candidate genes, genes to be in a potential region for muscle development. However, we also found candidate gene SLC13A1 on BTA4, which seems to be associated with bone disorders (such as chondrodysplasia) in Simmental beef cattle.

Integrated analysis of lncRNA and mRNA expression in rainbow trout families showing variation in muscle growth and fillet quality traits

Muscle yield and quality traits are important for the aquaculture industry and consumers. Genetic selection for these traits is difficult because they are polygenic and result from multifactorial interactions. To study the genetic architecture of these traits, phenotypic characterization of whole body weight (WBW), muscle yield, fat content, shear force and whiteness were measured in ~500 fish representing 98 families from a growth-selected line. RNA-Seq was used to sequence the muscle transcriptome of different families exhibiting divergent phenotypes for each trait. We have identified 240 and 1,280 differentially expressed (DE) protein-coding genes and long noncoding RNAs (lncRNAs), respectively, in fish families exhibiting contrasting phenotypes. Expression of many DE lncRNAs (n = 229) was positively correlated with overlapping, neighboring or distantly located protein-coding genes (n = 1,030), resulting in 3,392 interactions. Three DE antisense lncRNAs were co-expressed with sense genes known to impact muscle quality traits. Forty-four DE lncRNAs had potential sponge functions to miRNAs that affect muscle quality traits. This study (1) defines muscle quality associated protein-coding and noncoding genes and (2) provides insight into non-coding RNAs involvement in regulating growth and fillet quality traits in rainbow trout.

Novel genetic polymorphisms associated with carcass traits in grazing Texel sheep

Improving meat production traits has increased its importance in sheep breeding. We report novel associations of SNP present in genes related to lipid metabolism and growth with several carcass traits in purebred Texel lambs. Expected progeny differences (EPD) predictions from 461 animals from the Central Progeny Testing of Texel breed in Uruguay were used for the association analysis. Live weights at different stages, ultrasound and post-mortem traits were analyzed. Markers in several genes were associated with growth, carcass and meat quality traits. Among others: PPARGC1A with valuable cuts weight, hot carcass weight and carcass fatness; DGAT1 with live weights, fat thickness, rib-eye area and shoulder weight; CAST with birth weight and fat thickness; GHR with birth weight and carcass fatness, and GHRHR with live weights and fat thickness. Genotypic effects ranged from 0.035 to 0.923 (DGAT1 vs. weaning weight) units of phenotypic SD. Most of the associations described are novel in sheep breeding, deserving further analyses.

Detection of selection signatures in Piemontese and Marchigiana cattle, two breeds with similar production aptitudes but different selection histories

BACKGROUND

Domestication and selection are processes that alter the pattern of within- and between-population genetic variability. They can be investigated at the genomic level by tracing the so-called selection signatures. Recently, sequence polymorphisms at the genome-wide level have been investigated in a wide range of animals. A common approach to detect selection signatures is to compare breeds that have been selected for different breeding goals (i.e. dairy and beef cattle). However, genetic variations in different breeds with similar production aptitudes and similar phenotypes can be related to differences in their selection history.

METHODS

In this study, we investigated selection signatures between two Italian beef cattle breeds, Piemontese and Marchigiana, using genotyping data that was obtained with the Illumina BovineSNP50 BeadChip. The comparison was based on the fixation index (Fst), combined with a locally weighted scatterplot smoothing (LOWESS) regression and a control chart approach. In addition, analyses of Fst were carried out to confirm candidate genes. In particular, data were processed using the varLD method, which compares the regional variation of linkage disequilibrium between populations.

RESULTS

Genome scans confirmed the presence of selective sweeps in the genomic regions that harbour candidate genes that are known to affect productive traits in cattle such as DGAT1, ABCG2, CAPN3, MSTN and FTO. In addition, several new putative candidate genes (for example ALAS1, ABCB8, ACADS and SOD1) were detected.

CONCLUSIONS

This study provided evidence on the different selection histories of two cattle breeds and the usefulness of genomic scans to detect selective sweeps even in cattle breeds that are bred for similar production aptitudes.

The influence of vitamin D receptor genetic variants on bone mineral density and osteoporosis in Chinese postmenopausal women

Growing evidence indicates that the vitamin D receptor (VDR) gene is an important candidate gene for influencing the development of osteoporosis. The aim of the study was to evaluate the potential association between genetic variants of VDR gene and bone mineral density (BMD) and osteoporosis in Chinese postmenopausal women. The study included 970 Chinese postmenopausal women at the postmenopausal osteoporosis (482) and healthy controls (488). The BMD of lumbar spine (L_2–4 anterior-posterior view), femoral neck hip, and total hip was evaluated using the Norland XR-46 dual energy X-ray absorptiometry (DEXA). The genotypes of VDR genetic variants were determined by the created restriction site-PCR (CRS-PCR) and confirmed by DNA sequencing methods. Our data indicated that the VDR p.Glicine (Gly)14 alanine (Ala) and p.histidine (His) 305 glutanine (Gln) genetic variants were statistically associated with adjusted femoral neck hip BMD, adjusted lumbar spine BMD, and adjusted total hip BMD (P values < 0.05). Results from this study suggest that the VDR p.Gly14Ala and p.His305Gln genetic variants are significantly associated with BMD decrease in Chinese postmenopausal women and might be used as molecular markers for assessing the risk of BMD and osteoporosis.

The influence of XRCC1 genetic variants on lung cancer susceptibility in Chinese Han population

Growing evidence suggests that genetic variants of X-ray repair cross-complementing group 1 proteins (XRCC1) contribute to genetic effects on the development of lung cancer. This case-control study aims to evaluate the genetic effects of XRCC1 c.482C>T and c.1686C>G single nucleotide polymorphisms (SNPs) on lung cancer susceptibility. 391 lung cancer patients and 398 cancer-free controls were enrolled in this study. The genotypes of c.482C>T and c.1686C>G genetic variants were detected by the created restriction site-polymerase chain reaction (CRS-PCR), PCR-restriction fragment length polymorphism (PCR-RFLP) and DNA sequencing methods. The genetic effects on lung cancer susceptibility were evaluated using association analyses by the unconditional logistic regression model. Our data indicated that there were significant differences in the distribution of allelic and genotypic frequencies between lung cancer patients and cancer-free controls. The XRCC1 c.482C>T and c.1686C>G genetic variants were significantly associated with the susceptibility to lung cancer (for c.482C>T, TT versus (vs.) CC: OR=2.14, 95% CI 1.31-3.48, P=0.002; T vs. C: OR=1.37, 95% CI 1.10-1.69, P=0.004; for c.1686C>G, GG vs. CC: OR=2.53, 95% CI 1.46-4.38, P=0.001; G vs. C: OR=1.33, 95% CI 1.06-1.65, P=0.012). These preliminary results suggested that the XRCC1 c.482C>T and c.1686C>G genetic variants might play genetic effects on the susceptibility to lung cancer in the studied population.

The association between serum ApoE genetic polymorphism and serum lipid level in hemodialysis patients

Growing evidence indicates that apolipoprotein E (ApoE) is one of the most important candidate genes for influencing the development of hemodialysis (HD). This study aims to detect the potential association between serum ApoE genetic polymorphism and serum lipid level in HD. A total of 485 subjects were enrolled in this case-control study. The created restriction site polymerase chain reaction and DNA sequencing methods were used to investigate ApoE c.109G>A genetic polymorphism. Our data suggested that there were significant differences in the distribution of allelic and genotypic frequencies between HD patients and healthy controls. The levels of total cholesterol, triglyceride, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, ApoA-I, ApoB, ApoE, and lipoprotein (a) for genotype AA were different from genotype GG in HD patients and healthy controls. Our findings support that the ApoE c.109G>A genetic polymorphism might influence the development of HD and could be a risk factor for assessing HD.

The effects of serum apolipoprotein E genetic variants and concentration on serum lipid parameters in haemodialysis patients

Objectives

Many epidemiological studies demonstrate that the apolipoprotein E gene (ApoE) is an important candidate gene for playing key roles in the development of haemodialysis (HD). The purpose of this study is to evaluate the effects of ApoE genetic variants and concentration on serum lipid parameters in HD.

Methods

A total of 288 HD patients and 292 healthy controls were enrolled in this case–control study. The genotypes of ApoE genetic variants were investigated through the created restriction site-polymerase chain reaction and DNA-sequencing methods.

Key findings

Our data indicated that the levels of triglyceride, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, apolipoprotein A-I (ApoA-I), ApoB, ApoE, lipoprotein (a) (Lp(a)) of mutant genotypes in ApoE c.61G &gt; A and c.761T &gt; A genetic variants were different from those subjects with wild genotype in HD patients and healthy controls.

Conclusions

These preliminary results from this study suggest that the ApoE genetic variants and concentration could affect the serum lipid parameters in HD and could be risk factors for evaluating HD.

The association of MDM2 c.346G>A genetic variant with the risk of osteosarcoma in Chinese

Previous studies suggest that the MDM2 gene is one of the most important candidate genes for influencing the risk of osteosarcoma. This study aims to investigate the potential association of MDM2 c.346G>A genetic variant with the risk of osteosarcoma in Chinese. A total of 738 subjects were recruited in this study. The genotypes of MDM2 c.346G>A genetic variant were detected by the created restriction site-polymerase chain reaction. Our data suggest that the MDM2 c.346G>A genetic variant is associated with the increased risk of osteosarcoma in the homozygote comparison (AA vs. GG: odds ratio [OR]=2.36, 95% confidence interval [CI] 1.30-4.28, χ2=8.35, p=0.004), recessive model (AA vs.

GA/GG

OR=2.32, 95% CI 1.30-4.13, χ2=8.50, p=0.004), and allele comparison (A vs. G: OR=1.27, 95% CI 1.01-1.60, χ2=4.34, p=0.037). Results from this study indicated that the allele-A and genotype-AA of MDM2 c.346G>A genetic variant could be an increased risk factor for the susceptibility to osteosarcoma and might be used as a potential molecular marker for evaluating the risk of osteosarcoma.

Glioma risks associate with genetic polymorphisms of XRCC1 gene in Chinese population

Glioma is the most common type of primary brain tumors in adults. Previous evidence indicates that the X-ray repair cross-complementing group 1 gene (XRCC1) is an important candidate gene which influencing the pathogenesis of glioma. This study aims to assess the potential associations between glioma risks and genetic polymorphisms of XRCC1 gene. A total of 1,286 Chinese Han ethnic subjects consisting of 638 glioma patients and 648 controls were recruited in this case-control study. The genotyping of XRCC1 genetic polymorphisms (c.482C>T, c.1161G>A, and c.1804C>A) were conducted using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), created restriction site-PCR (CRS-PCR) and DNA sequencing methods. Our data indicated that the allelic and genotypic frequencies of these genetic polymorphisms in glioma patients were significantly different from those of controls. We detected that the alleles/genotypes were statistically associated with the increased risks of glioma (for c.482C>T, TT versus (vs.) CC: OR = 2.24, 95% CI = 1.48-3.39, P < 0.001; T vs. C: OR = 1.30, 95% CI = 1.09-1.53, P = 0.003; for c.1161G>A, AA vs. GG: OR = 1.62, 95% CI = 1.11-2.35, P = 0.012; A vs. G: OR = 1.19, 95% CI = 1.01-1.41, P = 0.040; for c.1804C>A, AA vs. CC: OR = 2.12, 95% CI = 1.45-3.11, P < 0.001; A vs. C: OR = 1.32, 95% CI = 1.12-1.56, P = 0.001). Our findings suggest that these genetic polymorphisms of XRCC1 gene may influence glioma risks in Chinese Han ethnic subjects, and might be potential molecular markers for evaluating glioma risks.

Association analysis between g.18873C>T and g.27522G>A genetic polymorphisms of OPG and bone mineral density in Chinese postmenopausal women

Several studies report that the OPG is an important candidate gene in the pathogenesis of osteoporosis. This study aimed to detect the potential association of OPG gene polymorphisms with osteoporosis in postmenopausal women. We recruited 928 subjects containing 463 with primary postmenopausal osteoporosis and 465 healthy volunteers as controls. The BMD of neck hip, lumbar spine (L_2–4), and total hip were assessed by dual-energy X-ray absorptiometry (DEXA). Through the created restriction site-polymerase chain reaction (CRS-PCR), PCR-restriction fragment length polymorphism (PCR-RFLP), and DNA sequencing methods, the g.18873C>T and g.27522G>A have been investigated. As for g.18873C>T, our data indicated that subjects with CC genotype have significantly higher BMD value than those of CT and TT genotypes (all P values < 0.05). As for g.27522G>A, the BMD values of subjects with GG genotype were significantly higher than those of GA and AA genotypes (all P values < 0.05). Our findings suggest that the OPG g.18873C>T and g.27522G>A genetic polymorphisms are associated with the decreased risk for osteoporosis in Chinese postmenopausal women.

Association analysis between 8-oxoguanine DNA glycosylase genetic variants and endometrial cancer susceptibility in Chinese Han population

Objectives

Numerous epidemiologic studies demonstrate that 8-oxoguanine DNA glycosylase gene (hOGG1) is an important candidate gene for the development of endometrial cancer (EC). The objective of this study is to evaluate the potential association between hOGG1 genetic variants and the susceptibility to EC.

Methods

In total, 218 EC patients and 243 cancer-free controls were recruited in this study.

Key findings

Our data indicate that the hOGG1 c.269C &gt; A and c.828A &gt; G genetic variants are statistically associated with the increased susceptibility to EC (for c.269C &gt; A, AA vs CC: odds ratio (OR) = 2.14, 95% confidence interval (CI), 1.21 to 3.78, P = 0.008; A vs C: OR = 1.43, 95% CI, 1.09 to 1.88, P = 0.010; for c.828A &gt; G, GG vs AA: OR = 2.31, 95% CI, 1.24 to 4.30, P = 0.008; G vs A: OR = 1.35, 95% CI, 1.03 to 1.78, P = 0.032). The A allele and AA genotype of c.269C &gt; A and G allele and GG genotype of c.828A &gt; G genetic variants could contribute to the susceptibility to EC.

Conclusion

Taken together, our findings suggest that the hOGG1 c.269C &gt; A and c.828A &gt; G genetic variants are significantly associated with EC susceptibility in Chinese Han populations and might be used as molecular markers for assessing the risk of EC.

The association between XRCC1 genetic polymorphisms and the risk of endometrial carcinoma in Chinese

Accumulated evidences report that X-ray repair cross-complementing group 1 gene (XRCC1) genetic polymorphisms play an important role in the development of endometrial carcinoma (EC). This study aims to evaluate the association of XRCC1 c.1161G>A and c.1804C>A genetic polymorphisms with the risk of EC. A total of 218 EC patients and 243 cancer-free controls were included in this study. The genotypes of XRCC1 genetic polymorphisms were determined by the created restriction site-polymerase chain reaction (CRS-PCR) and PCR-restriction fragment length polymorphism (PCR-RFLP) methods. We found that these two genetic polymorphisms were statistically associated with the risk of EC. As for c.1161G>A, in comparison with GG wild genotype, the AA genotype was significantly associated with the increased risk of EC (OR=2.36, 95% CI 1.28-4.37, χ(2)=7.71, P=0.005). As for c.1804C>A, the CC genotype significantly increased the risk of EC in comparison with CC wild genotype (OR=2.77, 95% CI 1.38-5.58, χ(2)=8.54, P=0.003). Our data indicate that the A allele of c.1161G>A and c.1804C>A genetic polymorphisms could contribute to increase the risk of EC (for c.1161G>A: A versus (vs.) G, OR=1.34, 95% CI 1.02-1.76, χ(2)=4.56, P=0.033; for c.1804C>A: A vs. C, OR=1.34, 95% CI 1.01-1.77, χ(2)=4.03, P=0.045). Our results indicate that the XRCC1 c.1161G>A and c.1804C>A genetic polymorphisms significantly influenced the risk of EC in Chinese populations, and might be used as molecular markers for evaluating EC risk.

Association between the c.3751G>a genetic variant of MDR1 and hepatocellular carcinoma risk in a Chinese Han population

The objective of this study was to evaluate the influence of a genetic variant in the multidrug resistance 1 gene (MDR1) on hepatocellular carcinoma (HCC) risk. This case-control study was conducted in a Chinese population of 645 HCC cases and 658 cancer-free controls. The genotype of the c.3751G>A genetic variant in the MDR1 gene was investigated by created restriction site-polymerase chain reaction (CRS-PCR) and DNA sequencing methods. Our data demonstrated significantly differences detected in the allelic and genotypic frequencies between HCC cases and those of cancer-free controls. Association analyses indicated that there were statistically increased risk of HCC in the homozygote comparison (AA versus (vs.) GG: OR = 2.22, 95% CI 1.51-3.27, χ(2) = 16.90, P < 0.001), dominant model (AA/GA vs. GG: OR = 1.25, 95% CI 1.00-1.55, χ(2) = 3.98, P = 0.046), recessive model (AA vs.

GA/GG

OR = 2.14, 95% CI 1.47-3.09, χ(2) = 16.68, P < 0.001) and allele comparison (A vs. G: OR = 1.33, 95% CI 1.13-1.57, χ(2) = 11.66, P = 0.001). The allele-A and genotype-AA may contribute to HCC susceptibility. These preliminary findings suggest that the c.3751G>A genetic variant in the MDR1 gene is potentially related to HCC susceptibility in a Chinese Han population, and might be used as a molecular marker for evaluating HCC susceptibility.

Association of XRCC1 gene polymorphisms with susceptibility to gastric cancer in Chinese Han population

OBJECTIVES

Gastric cancer is one of the most frequently causing cancer-related deaths worldwide. The X-ray repair complementing group 1 gene (XRCC1) is an important candidate gene for influencing gastric cancer risk. This study aimed to evaluate the associations between XRCC1 genetic variants and gastric cancer susceptibility in Chinese Han population.

METHODS

Four hundred twenty-four gastric cancer patients and 430 cancer-free controls were enrolled. Two genetic variants (c.1254C>T and c.1779C>G) of XRCC1 gene were genotyped by created restriction site-polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism methods, respectively.

KEY FINDINGS

Results from this study indicated that the allele and genotype frequencies of these two genetic variants were statistically different between gastric cancer patients and cancer-free controls. The association analyses suggested that these two genetic variants were statistically associated with the increased risk of gastric cancer (for c.1254C>T, T versus C: odds ratio (OR) = 1.44, 95% confidence interval (CI) 1.17-1.77; for c.1779C>G, G versus C: OR = 1.51, 95% CI 1.22-1.86). The allele-T of c.1254C>T and allele-G c.1779C>G genetic variants may contribute to the susceptibility to gastric cancer in Chinese Han population.

CONCLUSION

Our data suggest that these two genetic variants might be used as molecular markers for evaluating the susceptibility to gastric cancer.

Association analysis between MTHFR genetic polymorphisms and the risk of congenital heart diseases in Chinese Han population

OBJECTIVES

Congenital heart diseases (CHD) are common birth defects in the world. The methylenetetrahydrofolate reductase (MTHFR) gene is one of the most important candidate genes for the development of CHD. This case-control study aimed to evaluate the effect of MTHFR c.382A>G and c.1129C>T genetic polymorphisms as risk factors for the development of CHD.

METHODS

A total of 230 CHD patients and 237 non-CHD controls were included in the present study. The genotyping of MTHFR c.382A>G and c.1129C>T genetic polymorphisms were detected by the polymerase chain reaction-restriction fragment length polymorphism and created restriction site-polymerase chain reaction methods, respectively.

KEY FINDINGS

The alleles/genotypes distribution from these two genetic polymorphisms were statistically associated with the increased risk of CHD (for c.382A>G, GG versus AA: odds ratio (OR) = 2.39, 95% confidence interval (CI), 1.27 to 4.52, P = 0.006; for c.1129C>T, TT versus CC: OR = 2.73, 95% CI, 1.33 to 5.62, P = 0.005). The allele G and genotype GG of c.382A>G and allele T and genotype TT of c.1129C>T genetic polymorphisms might contribute to CHD susceptibility.

CONCLUSION

These preliminary findings indicate that these two MTHFR genetic polymorphisms are related with the risk of CHD in Chinese Han population, and might be potentially utilized as molecular markers.

Association between CTLA-4 genetic polymorphisms and susceptibility to osteosarcoma in Chinese Han population

Osteosarcoma (OS) is the most common malignant primary bone tumor in the world. The cytotoxic T-lymphocyte antigen-4 gene (CTLA-4) is an important candidate gene for influencing the development of OS. This study aimed to investigate the potential association of CTLA-4 genetic polymorphisms with OS risk in Chinese Han population. A total of 415 OS patients and 431 healthy controls were enrolled in this study. The created restriction site-polymerase chain reaction (CRS-PCR) and DNA sequencing methods were used to detect the genotyping of CTLA-4 c.75G[C and c.326G[A genetic polymorphisms. We observed that the genotypes/alleles of c.75G[C and c.326G[A genetic polymorphisms were statistically associated with the increased risk of OS (for c.75G[C, CC versus (vs.) GG: OR 1.72, 95% CI 1.09–2.74; C vs. G: OR 1.30, 95% CI 1.06–1.60; for c.326G[A, AA vs. GG: OR 2.12, 95% CI 1.31–3.42; A vs. G: OR 1.31, 95% CI 1.07–1.61). The allele-C/genotype-CC of c.75G[C and allele-A/genotype-AA of c.326G[A may contribute to OS susceptibility. These data indicate that CTLA-4 genetic polymorphisms are potentially related to OS risk in Chinese Han population, and might be used as molecular markers for evaluating the risk of OS.

Genetic polymorphisms of XRCC1 gene and susceptibility to hepatocellular carcinoma in Chinese population

Hepatocellular carcinoma (HCC) is a common cancer in the worldwide. Accumulated evidences indicate that genetic polymorphisms of human X-ray repair complementing group 1 gene (XRCC1) are associated with the susceptibility to HCC. This study aims to investigate the potential association between XRCC1 c.482C>T and c.1178G>A genetic polymorphisms and the susceptibility to HCC. A total of 1,069 Chinese Han subjects consisting of 530 HCC patients and 539 cancer-free controls were recruited in this case-control study. The created restriction site-polymerase chain reaction and directly DNA sequencing methods were utilized to analyze the genotyping of XRCC1 genetic polymorphisms. Our data suggested that the XRCC1 c.482C>T and c.1178G>A genetic polymorphisms were statistically associated with the increased risks of HCC [for c.482C>T, TT vs. CC: OR 2.05, 95% CI 1.26-3.32, P = 0.003; T vs. C: OR 1.26, 95% CI 1.04-1.51, P = 0.017; for c.1178G>A, AA vs. GG: OR 2.15, 95% CI 1.26-3.67, P = 0.004; A vs. G: OR 1.33, 95% CI 1.10-1.61, P = 0.004]. The allele-T and genotype-TT of c.482C>T and allele-A and genotype-AA of c.1178G>A genetic polymorphisms may enhance the susceptibility to HCC. Our findings indicate that the studied XRCC1 genetic polymorphisms may influence the risk of HCC in Chinese populations and might be used as molecular markers for assessing the risk of HCC.

Association analysis between the c.1804C>A genetic polymorphism of XRCC1 gene and risk of hepatocellular carcinoma in Chinese population

Hepatocellular carcinoma (HCC) is a common liver malignancy in the world. The X-ray repair cross-complementing group 1 gene (XRCC1) is one of the most important candidate genes for influencing HCC risk. The purpose of this study was to evaluate the association between genetic polymorphisms of XRCC1 and HCC risk. A total of 592 HCC patients and 594 healthy controls were recruited in this case-control study. The c.1804C>A genetic polymorphism of XRCC1 gene was genotyped by the created restriction site-polymerase chain reaction and DNA sequencing methods. Our data suggested that the c.1804C>A genetic polymorphism of XRCC1 gene was significantly associated with the increased risk of HCC in the homozygote comparison (AA vs. CC: odds ratio (OR) 1.92, 95% confidence interval (CI) 1.25-2.94, P=0.003), recessive model (AA vs.

CA/CC

OR 1.93, 95% CI 1.28-2.92, P=0.002), and allele comparison (A vs. C: OR 1.20, 95% CI 1.00-1.42, P=0.045). The allele A and genotype AA might contribute to the susceptibility to HCC. Our findings support that c.1804C>A genetic polymorphism of XRCC1 gene plays a genetic influence on the susceptibility to HCC in the studied population.

Association between the g.14461A>G genetic polymorphism of the TLR4 gene and type 2 diabetes mellitus risk in a Chinese population

OBJECTIVE

Toll-like receptor 4 (TLR4) is an important candidate gene for mediating the susceptibility to type 2 diabetes mellitus (T2DM). The purpose of this study was to investigate the association between the TLR4 gene polymorphisms and T2DM susceptibility.

METHODS

A total of 671 T2DM patients and 677 healthy controls were recruited in this study. The created restriction site-polymerase chain reaction and DNA sequencing methods have been used to analyze the TLR4 gene polymorphisms.

RESULTS

One novel genetic polymorphism (g.14461A>G) was found. Our data indicated that the g.14461A>G genetic polymorphism was significantly associated with the increased susceptibility to T2DM in a homozygote comparison (GG vs. AA: odds ratio [OR]=2.09, 95% confidence interval [CI] 1.44-3.04, p<0.001), dominant model (GG/AG vs. AA: OR=1.27, 95% CI 1.03-1.57, p=0.028), recessive model (GG vs.

AG/AA

OR=1.98, 95% CI 1.39-2.83, p<0.001), and allele contrast (G vs. A: OR=1.33, 95% CI 1.13-1.57, p=0.001). The allele-G might be the risk allele for enhancing the susceptibility to T2DM.

CONCLUSION

These preliminary findings suggest that the g.14461A>G genetic polymorphism of the TLR4 gene is potentially related to the susceptibility to T2DM in the studied population.

Investigation on XRCC1 genetic polymorphism and its relationship with breast cancer risk factors in Chinese women

Breast cancer (BC) remains one of the most common cancers among women. The human X-ray repair cross-complementing 1 (XRCC1) gene plays key roles in base excision repair, and genetic polymorphisms of XRCC1 may be associated with the susceptibility to BC. This study aimed to evaluate the relationship between the XRCC1 genetic polymorphisms and BC susceptibility. A total of 354 BC patients and 366 cancer-free controls were enrolled in this study. Data about the risk factors of BC were collected using questionnaires. The XRCC1 genetic polymorphism was determined using created restriction site-polymerase chain reaction (CRS-PCR) and DNA sequencing methods. No significant differences in the allelic and genotypic frequencies of c.1804C>A genetic polymorphism were detected between cases and controls. The distributions of BC patients' risk factors were not significantly different between CC, CA, and AA genotypes. These findings indicate that the c.1804C>A genetic polymorphism of XRCC1 gene is not significantly associated with BC susceptibility in the Chinese women.

Association between the g.296596G > A genetic variant of RELN gene and susceptibility to autism in a Chinese Han population

Autism is a childhood neuro-developmental disorder, and Reelin (RELN) is an important candidate gene for influencing autism. This study aimed at investigating the influence of genetic variants of the RELN gene on autism susceptibility. In this study, 205 autism patients and 210 healthy controls were recruited and the genetic variants of the RELN gene were genotyped by the created restriction site-polymerase chain reaction (CRS-PCR) method. The influence of genetic variants on autism susceptibility was analyzed by association analysis, and the g.296596G > A genetic variant in exon10 of the RELN gene was detected. The frequencies of allele/genotype in autistic patients were significantly different from those in healthy controls, and a statistically significant association was detected between this genetic variant and autism susceptibility. Our data lead to the inference that the g.296596G > A genetic variant in the RELN gene has a potential influence on autism susceptibility in the Chinese Han population.

Association analysis between MDR1 genetic variant and breast cancer risk factors in Chinese Han population

The multidrug resistance 1 gene (MDR1) is an important candidate gene for influencing breast cancer susceptibility. This study aimed to evaluate the association between MDR1 genetic variants and breast cancer susceptibility. A total of 340 breast cancer patients and 348 cancer-free controls were enrolled in this study. The patients' general characteristics and related risk factors of breast cancer were collected by questionnaires. The c.4125A>C genetic variant was genotyped through created restriction site polymerase chain reaction method. Our data suggest that there are no significant differences in the allelic and genotypic frequencies between breast cancer patients and cancer-free controls. Moreover, the distribution of breast cancer patients' risk factors is not different among AA, AC, and CC genotypes. These preliminary results suggest that the c.4125A>C genetic variant is not significantly associated with breast cancer susceptibility.

Association study of single nucleotide polymorphisms in XRCC1 gene with the risk of gastric cancer in Chinese population

Gastric cancer is one of highly cancer-related deaths in the world. Previous evidence suggests that the X-ray repair cross-complementing group 1 gene (XRCC1) is one of the most important candidate genes for influencing gastric cancer risk. The objective of this study was to detect the potential association of genetic variants in XRCC1 gene with gastric cancer risk in Chinese Han population. In total, we enrolled 395 gastric cancer patients and 398 cancer-free controls in this study. The genotyping of c.910A>G and c.1804C>A genetic variants in XRCC1 gene were investigate by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and created restriction site-PCR (CRS-PCR) methods, respectively. We found the genotypes/alleles from these two genetic variants were statistically associated with the increased risk of gastric cancer (for c.910A>G, GG versus (vs.) AA: OR = 2.00, 95% CI 1.21-3.31; AG vs. AA: OR = 1.50, 95% CI 1.12-2.02; GG/AG vs. AA: OR = 1.59, 95% CI 1.20-2.10; GG vs.

AG/AA

OR = 1.68, 95% CI 1.03-2.73; G vs. A: OR = 1.47, 95% CI 1.18-1.83; for c.1804C>A, AA vs. CC: OR = 2.68, 95% CI 1.46-4.94; AA vs.

CA/CC

OR = 2.62, 95% CI 1.44-4.76; A vs. C: OR = 1.33, 95% CI 1.06-1.66). The allele-G of c.910A>G and allele-A of c.1804C>A genetic variants may contribute to gastric cancer susceptibility. These preliminary results indicate that these XRCC1 genetic variants are potentially related to gastric cancer susceptibility in Chinese Han population, and might be used as molecular markers.

Genetic polymorphisms of XRCC1 gene and susceptibility to gastric cancer in Chinese Han population

This study aims to evaluate whether the c.1471G > A and c.1686C > G genetic polymorphisms of XRCC1 gene influencing gastric cancer susceptibility. A total of 813 subjects with Chinese Han ethnicity were enrolled. Our data suggest that the allele and genotype frequencies are significantly different from gastric cancer patients with cancer-free controls. We find that c.1471G > A and c.1686C > G genetic polymorphisms statistically increase the risk of gastric cancer. Our findings indicate these two genetic polymorphisms are related with the susceptibility to gastric cancer, and could be used as molecular markers for detecting gastric cancer in Chinese Han ethnicity.

Association of XRCC1 gene single nucleotide polymorphisms and susceptibility to pancreatic cancer in Chinese

The human X-ray repair cross-complementing group 1 gene (XRCC1) is an important candidate gene for affecting pancreatic cancer (PC) risk. The objective of this study was to detect whether the c.1471G > A and c.1686C > G polymorphisms of XRCC1 gene influence PC risk. The association of XRCC1 genetic variants with PC risk was analyzed in 328 PC patients and 350 controls by the polymerase chain reaction-restriction fragment length polymorphism and created restriction site-polymerase chain reaction method. Our data suggested that the genotypes and alleles from these two genetic variants were statistically associated with PC risk. For c.1471G > A, the AA genotype was associated with the decreased risk of developing PC compared to GG wild genotype (odds ratio (OR) = 0.43, 95% confidence intervals (CI) 0.26-0.70, chi-squared (χ(2)) = 11.91, P = 0.001). For c.1686C > G, the risk of PC was significantly lower for GG genotype in comparing to CC wild genotype (OR = 0.48, 95% CI 0.29-0.81, χ(2) = 7.98, P = 0.005). The A allele of c.1471G > A and G allele of c.1686C > G genetic variants could contribute to decrease the risk of PC (for c.1471G > A: A vs G, OR = 0.65, 95% CI 0.52-0.82, χ(2) = 13.71, P < 0.001, for c.1686C > G: G vs C, OR = 0.70, 95% CI 0.55-0.88, χ(2) = 9.42, P = 0.002). Our findings indicate that the c.1471G > A and c.1686C > G polymorphisms of XRCC1 gene are associated with PC risk in Chinese population.

Association study of single nucleotide polymorphisms in XRCC1 gene with risk of hepatocellular carcinoma in Chinese Han population

Hepatocellular carcinoma (HCC) is one of the most frequently causing cancer-related deaths worldwide. Previous evidence suggests that the X-ray repair cross-complementing group 1 gene (XRCC1) is an important candidate gene for influencing the risk of HCC. The aim of this study was to assess the association of XRCC1 genetic polymorphisms with the risk of HCC in Chinese Han population. A total of 1314 subjects, including 651 HCC patients and 663 healthy controls, were enrolled in this case-control study. Two genetic variants (c.1254C>T and c.1517G>C) in XRCC1 gene were genotyped by created restriction site-polymerase chain reaction (CRS-PCR) and PCR-restriction fragment length polymorphism (PCR-RFLP) methods. Our data indicated that the allele and genotype frequencies of these two genetic variants were statistical difference in HCC cases and healthy controls. Association analyses suggested that these two genetic variants were statistically associated with the increased risk of HCC in all genetic models (for c.1254C>T, TT versus CC: OR = 2.30, 95% CI 1.61–3.28; CT versus CC: OR = 1.32, 95% CI 1.05–1.67; TT/CT versus CC: OR = 1.50, 95% CI 1.20–1.86; TT versus CT/CC: OR = 2.00, 95% CI 1.43–2.80; T versus C: OR = 1.47, 95% CI 1.25–1.73; for c.1517G>C, CC versus GG: OR = 1.90, 95% CI 1.34–2.69; GC versus GG: OR = 1.56, 95% CI 1.24–1.97; CC/GC versus GG: OR = 1.63, 95% CI 1.31–2.03; CC versus GC/GG: OR = 1.52, 95% CI 1.10–2.11; C versus G: OR = 1.45, 95% CI 1.23–1.70). The allele-T of c.1254C>T and allele-C of c.1517G>C genetic variants may contribute to HCC susceptibility in Chinese Han population.

The relationship between osteoprotegerin gene polymorphisms and bone mineral density in Chinese postmenopausal women

Previous evidence supports that the osteoprotegerin (OPG) gene is one of the most important candidate genes for influencing the pathogenesis of osteoporosis. The objective of this study was to investigate the relationship between OPG gene polymorphisms and osteoporosis in Chinese postmenopausal women. A total of 764 subjects were included in this study. The bone mineral density (BMD) in the lumbar spine (L2-4), neck hip and total hip was determined by dual-energy X-ray absorptiometry (DEXA). The g.19190C>A and g.25602A>G SNPs were detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), created restriction site PCR (CRS-PCR) and DNA sequencing methods. As for g.19190C>A, our data suggested that the BMD value of lumbar spine (L2-4), neck hip and total hip for subjects with CC genotype was significantly higher than that of CA and AA genotypes (P<0.05). No significant difference was detected between the association of g.25602A>G genotypes with spine BMD and neck hip BMD, while total hip BMD almost reached the significant level (P=0.063). These findings provide more evidence that the SNPs in OPG gene could affect BMD and osteoporosis, and the allele-A of g.19190C>A and allele-G of g.25602A>G genetic variants are associated with increased risk for osteoporosis in Chinese postmenopausal women.

Association between single genetic polymorphisms of MDR1 gene and gastric cancer susceptibility in Chinese

Gastric cancer is a common cancer worldwide. The multidrug resistance 1 gene (MDR1) is one of the most important candidate genes for influencing gastric cancer susceptibility. This study aimed to analyze the association between genetic variants of MDR1 gene and the susceptibility to gastric cancer in Chinese Han population. A total of 365 gastric cancer patients and 367 cancer-free controls were enrolled in this study. The single genetic polymorphisms (SNPs) of MDR1 gene were genotyped by the created restriction site-polymerase chain reaction method. Our data suggested that the allele and genotype frequencies of c.159G > T and c.1564A > T were statistically different between gastric cancer patients and cancer-free controls. Association analyses indicated that these two SNPs were statistically associated with the increased risk of gastric cancer (for c.159G > T, TT versus (vs.) GG: OR 2.34, 95 % CI 1.31-4.19; TT vs.

GT/GG

OR 2.32, 95 % CI 1.32-4.08; T vs. G: OR 1.27, 95 % CI 1.01-1.59; for c.1564A > T, TT vs. AA: OR 2.27, 95 % CI 1.31-3.93; TT vs.

AT/AA

OR 2.21, 95 % CI 1.30-3.75; T vs. A: OR 1.30, 95 % CI 1.04-1.62). The allele-T of both these two SNPs may contribute to the susceptibility to gastric cancer in Chinese Han population. The c.159G > T and c.1564A > T genetic variants might be used as molecular markers for detecting gastric cancer susceptibility.