Investigation on BRCA1 SNPs and its effects on mastitis in Chinese commercial cattle

Comparison of genetic diversity and phylogenetic structure of BRCA1 gene of some domestic and wild sheep breeds in different countries

BRCA1 gene plays an important role in DNA damage repair, cell cycle, and transcription process regulation; hence it's called gate keeper. The current research aims to perform bioinformatics analyzes of the BRCA1 gene of different breeds of domestic and wild sheep from 49 breeds in 14 countries using the NCBI genome database. The desired sequences were aligned using MEGA11 software and a phylogenetic tree was drawn by Neighbor-Joining method. The number of mutations, nucleotide diversity, and haploid diversity were also analyzed using Dnaspv5 software. The analyses showed 296 polymorphisms, which led to the creation of 45 different haplotypes with a haplotype diversity of 0.035. Nucleotide diversity and average nucleotide differences among breeds were estimated as 0.259 and 0.052, respectively. The average genetic distance within the population of countries was calculated as 0.052. The amount of sequence conservation in this research was 0.313 on average, which indicates the high polymorphism of this gene and the emergence of new proteins. Tajima's D value in Tajima's neutrality test was -2.421, which was significant (p < 0.05). One of the reasons for the high genetic diversity in Iran's wild sheep population is the existence of forests and open environments, which prevent genetic drift and reduce inbreeding.

Genetic polymorphisms in immune- and inflammation-associated genes and their association with bovine mastitis resistance/susceptibility

Bovine mastitis, the inflammation of the mammary gland, is a contagious disease characterized by chemical and physical changes in milk and pathological changes in udder tissues. Depressed immunity and higher expression of inflammatory cytokines with an elevated milk somatic cell count can be observed during mastitis in dairy cattle. The use of somatic cell count (SCC) and somatic cell score (SCS) as correlated traits in the indirect selection of animals against mastitis resistance is in progress globally. Traditional breeding for mastitis resistance seems difficult because of the low heritability (0.10-0.16) of SCC/SCS and clinical mastitis. Thus, genetic-marker-selective breeding to improve host genetics has attracted considerable attention worldwide. Moreover, genomic selection has been found to be an effective and fast method of screening for dairy cattle that are genetically resistant and susceptible to mastitis at a very early age. The current review discusses and summarizes the candidate gene approach using polymorphisms in immune- and inflammation-linked genes (CD4, CD14, CD46, TRAPPC9, JAK2, Tf, Lf, TLRs, CXCL8, CXCR1, CXCR2, C4A, C5, MASP2, MBL1, MBL2, LBP, NCF1, NCF4, MASP2, A2M, and CLU, etc.) and their related signaling pathways (Staphylococcus aureus infection signaling, Toll-like receptor signaling, NF-kappa B signaling pathway, Cytokine-cytokine receptor, and Complement and coagulation cascades, etc.) associated with mastitis resistance and susceptibility phenotypic traits (IL-6, interferon-gamma (IFN-γ), IL17, IL8, SCS, and SCC) in dairy cattle.

Polymorphisms of the IL-17A Gene Influence Milk Production Traits and Somatic Cell Score in Chinese Holstein Cows

The cow’s milk production characteristics are a significant economic indicator in the livestock industry. Serum cytokines such as interleukin-17 (IL-17) may be potential indicators for bovine mastitis concerning the milk somatic cell count (SCC) and somatic cell score (SCS). The current study aims to find previously undiscovered single nucleotide polymorphisms in the bovine (IL-17A) gene and further investigates their associations with milk production traits in Chinese Holstein cows. Twenty Chinese Holstein cows were randomly chosen from six farms in Jiangsu Province, China. The DNA was extracted from selected samples of bloods for PCR amplification Sequence analyses were used to find SNPs in the bovine (IL-17A) gene. The discovered five SNPs are g-1578A>G, g-1835G>A, and g-398T>A in the 5′UTR; g3164T>C and g3409G>C in the exon region. The genotyping of Holstein cows (n = 992) was performed based on Sequenom Mass ARRAY and SNP data. The connection between SNPs, milk production variables, and the somatic cell score was investigated using the least-squares method. Based on the results, SNP g-398T>A had a significant linkage disequilibrium with g3164T>C. SNPs were found to have significant (p < 0.05) correlations with the test-day milk yield. In conclusion, IL-17A affects cow’s milk production traits significantly.

Effect of the Histone Methyltransferase Specific Probe BRD4770 on Metabolic Profiling of the Endophytic Fungus Diaporthe longicolla

The endophytic fungus Diaporthe longicolla was isolated from the stem of Saraca asoca (Roxb.) Willd., commonly known as Ashok plant in India and Sri Lanka. Since no reports are available regarding epigenetic modulations by BRD4770 in microbial entities, D. longicolla was treated with different concentrations of BRD4770 for this purpose and evaluated for its antioxidant and antibacterial potential against five human pathogenic bacteria, Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), Shigella boydii, Klebsiella pneumoniae, and Escherichia coli. The crude extract obtained from cultures treated with 100 nM concentration of BRD4770 showed increased antioxidant activity and inhibition zone against S. aureus and MRSA, compared to the non-treated control. The composition of the non-treated and treated crude extract was analyzed, and induced compounds were identified with the help of Gas chromatography-mass spectrometry (GC-MS) and LC-ESI-MS/MS. LC-ESI-MS/MS analysis showed that berberine (antibacterial)-, caffeine-, and theobromine (antioxidant)-like compounds were induced in the BRD4770-treated crude extract. The presence of particular absorbance at a wavelength of 346.5 nm for berberine, 259.4 nm for caffeine, and 278.4 nm for theobromine in the reverse-phase high-performance liquid chromatography (HPLC) analysis of both BRD4770-treated crude metabolites and standard solution of the above compounds strongly supported the increased antibacterial and antioxidant activities that may be due to inducing the alterations in bioactivities of the BRD4770-treated culture.

Mining for the association of bovine mastitis linked genes to pathological signatures and Pathways

Background: Bovine mastitis is a common infectious disease with a serious threat to the dairy industry and public health. Mastitis is a polygenetic trait under the control of many genes. In the current study, our research attempted to address the role of mastitis-associated genes in various signalings including parasitic, viral, cancer and fungal diseases by using online bioinformatics software. Methods: We selected mastitis-associated genes from already published data and using online bioinformatics tools including DAVID and String classify the pathological role of relevant genes. A Venn diagram was used to show the status of overlapping genes among different biological function processes. Result: This study revealed that the genes gathered in published resources of mastitis were significantly correlated with Influenza A, Chagas disease, Leishmaniasis, Toxoplasmosis, Tuberculosis, Cancer signaling, Hepatitis B, Type I &II diabetes mellitus and Prion diseases biological pathways. Based on our findings, we concluded that mastitis-linked genes could be used as markers for many other diseases. Moreover, the Bioinformatics tools applied in the current study might be helpful in screening the genes involved in one disease and their association with other diseases as well.

In-Silico Analyses of Nonsynonymous Variants in the BRCA1 Gene

BReast CAncer gene 1 (BRCA1)-a tumor suppressor gene plays an important role in the DNA repair mechanism. Several BRCA1 variants perturb its structure and function, including synonymous and nonsynonymous single nucleotide polymorphisms (SNPs). In the present study, we performed in-silico analyses of nonsynonymous SNPs (nsSNPs) of the BRCA1 gene. In total, 122 nsSNPs were retrieved from the NCBI SNP database and in-silico analyses were performed using computational prediction tools: SIFT, PROVEAN, Mutation Taster, PolyPhen-2, MutPred, and ConSurf. Of these tools, SIFT, PROVEAN, and Mutation Taster predicted 61 out of 122 nsSNPs as "damaging", based on structural homology analysis. PolyPhen-2 classified 22 nsSNPs as "probably damaging". These nsSNPs were further analyzed by MutPred to predict basic molecular mechanisms of amino acid alteration. ConSurf analysis predicted eleven conserved amino acid residues with structural and functional consequences. We identified five amino acid residues in the RING finger domain (L22, C39, H41, C44, and C47) and two in the BRCT domain (P1771 and I1707) with the potential to deter the BRCA1 protein function. This study provides insights into the effect of nsSNPs and amino acid substitutions in BRCA1.

Polymorphism in DNA repair gene BRCA1 associated with clinical mastitis and production traits in indigenous dairy cattle

The present study was conducted on Karan Fries cows to identify SNPs in breast cancer 1 (BRCA1) gene and their association with inflammation of mammary gland and production traits. Chi square analysis showed significant association of both SNPs i.e. G43737229T (P < 0.01) and G43761121A (P < 0.05) with incidence of clinical mastitis. Logistic modeling showed that GG genotype cows of G43737229T SNP was less susceptible to mastitis in comparison to TT genotype cows as the odds ratio of TT against GG for the non-incidence of mastitis was less i.e. 0.23. Whereas, cows with genotype AA of G43761121A SNP were less prone to clinical mastitis in comparison to GG genotype cows. G-T haplotype and GGTT combined genotype exhibited maximum mastitis incidences. Least squares analysis revealed significant association of G43737229T SNP with total milk yield (P < 0.01), 305 days milk yield (P < 0.01) and lactation length (P < 0.05). The TT and GT genotyped Karan Fries cows were associated with higher milk yields during first and second lactation, as well as with first lactation length. These observations on SNPs, genotypes and combined genotypes of BRCA1 gene and their differential association with the incidence of mastitis and production traits can be utilized as an aid to selection for simultaneous improvement of both antagonistic traits.

Genome-wide association study of milk and reproductive traits in dual-purpose Xinjiang Brown cattle

Background

Dual-purpose cattle are more adaptive to environmental challenges than single-purpose dairy or beef cattle. Balance among milk, reproductive, and mastitis resistance traits in breeding programs is therefore more critical for dual-purpose cattle to increase net income and maintain well-being. With dual-purpose Xinjiang Brown cattle adapted to the Xinjiang Region in northwestern China, we conducted genome-wide association studies (GWAS) to dissect the genetic architecture related to milk, reproductive, and mastitis resistance traits. Phenotypic data were collected for 2410 individuals measured during 1995–2017. By adding another 445 ancestors, a total of 2855 related individuals were used to derive estimated breeding values for all individuals, including the 2410 individuals with phenotypes. Among phenotyped individuals, we genotyped 403 cows with the Illumina 150 K Bovine BeadChip.

Results

GWAS were conducted with the FarmCPU (Fixed and random model circulating probability unification) method. We identified 12 markers significantly associated with six of the 10 traits under the threshold of 5% after a Bonferroni multiple test correction. Seven of these SNPs were in QTL regions previously identified to be associated with related traits. One identified SNP, BovineHD1600006691, was significantly associated with both age at first service and age at first calving. This SNP directly overlapped a QTL previously reported to be associated with calving ease. Within 160 Kb upstream and downstream of each significant SNP identified, we speculated candidate genes based on functionality. Four of the SNPs were located within four candidate genes, including CDH2, which is linked to milk fat percentage, and GABRG2, which is associated with milk protein yield.

Conclusions

These findings are beneficial not only for breeding through marker-assisted selection, but also for genome editing underlying the related traits to enhance the overall performance of dual-purpose cattle.

DNA G-quadruplexes: functional significance in plant and farm animal science

G-quadruplexes (G4s) are non-canonical structures that can be formed in DNA and RNA sequences which carry four short runs of guanines. They are distributed in the whole genome but are enriched in gene promoter regions, gene UTRs and chromosome telomeres. The whole array of their functional roles is not fully explored yet but there is solid evidence supporting their implication in a number of processes like regulation of transcription, replication and telomere organization, among others. During the last decade, there is an increased research interest for G4s that has resulted in a better understanding of their role in several physiological and pathological conditions. On the other hand, these structures are poorly studied in plant species and animals of agricultural interest. Here, we summarize the current methods that are used for studying G4s, we review the studies concerning plants and farm animals and we discuss the advantages of a more thorough inclusion of G4s research in the agricultural sciences.

Detection of functional polymorphisms in the hsp70 gene and association with cold stress response in Inner-Mongolia Sanhe cattle

The genetic mechanisms underlying the cattle resilience to severe cold temperatures are still unknown. In this study, we observed that four blood biochemical parameters were significantly altered, i.e., blood adrenocorticotropic hormone (ACTH), triiodothyronine (T3), thyroxine (T4), and potassium (K+) after expose to - 32 °C for 3 h. This was observed using 105 healthy Sanhe heifers with similar weight (398.17 ± 34.06 kg) and age (19.30 ± 4.91 months). A total of 20 single nucleotide polymorphisms (SNPs) were identified in 5'-flanking region of the hsp70 gene in Sanhe cattle, while only 10 SNPs were segregating when comparing genetic variations between Sanhe cattle and 285 Chinese Holstein samples. Statistically significant associations between the genomic markers SNP-42-, SNP-105+, SNP-181+, and SNP-205+ with blood T3 and between SNP-105+ and blood T4 were observed by applying the general linear model procedure and Bonferroni t test. Furthermore, we demonstrated that the T alleles of SNP-42- and SNP-205+ in the GC box and Kozak sequence of the hsp70 gene, respectively, significantly decreased the green fluorescent proteins activity in vitro GFP reporter assays. These findings suggest that these two SNPs are causative polymorphisms involved in the regulation of hsp70 promoter activity and might contribute to the observed association between the hsp70 gene and T3 and T4 levels in Sanhe cattle. Thus, hsp70 gene is a promising candidate gene to be validated in independent cattle populations and functional studies related to cold stress resilience in cattle.

Genome-wide genetic structure and differentially selected regions among Landrace, Erhualian, and Meishan pigs using specific-locus amplified fragment sequencing

As typical Chinese indigenous pig breeds, Erhualian and Meishan have been widely used to produce new strain or breed in the world. However, the genetic basis of characteristics of these pig breeds is still limited. Moreover, considering cost and output of sequencing, it is necessary to further develop cost-effective method for pig genome screening. To contribute on this issue, we developed a SLAF-seq (specific-locus amplified fragment sequencing) method for pigs and applied it to analyze the genetic difference among Landrace, Erhualian, and Meishan pigs. A total of 453.75 million reads were produced by SLAF-seq. After quality-control, 165,670 SNPs (single nucleotide polymorphisms) were used in further analysis. The results showed that Landrace had distinct genetic relationship compared to Erhualian (F_ST = 0.5480) and Meishan (F_ST = 0.5800), respectively, while Erhualian and Meishan held the relatively close genetic relationship (F_ST = 0.2335). Furthermore, a genome-wide scanning revealed 268 differentially selected regions (DSRs) with 855 genes and 256 DSRs with 347 genes between Landrace and the two Chinese indigenous pig breeds and between Erhualian and Meishan, respectively. This study provides a new cost-effective method for pig genome study and might contribute to a better understanding on the formation mechanism of genetic difference among pigs with different geographical origins.

The Bos taurus-Bos indicus balance in fertility and milk related genes

Numerical approaches to high-density single nucleotide polymorphism (SNP) data are often employed independently to address individual questions. We linked independent approaches in a bioinformatics pipeline for further insight. The pipeline driven by heterozygosity and Hardy-Weinberg equilibrium (HWE) analyses was applied to characterize Bos taurus and Bos indicus ancestry. We infer a gene co-heterozygosity network that regulates bovine fertility, from data on 18,363 cattle with genotypes for 729,068 SNP. Hierarchical clustering separated populations according to Bos taurus and Bos indicus ancestry. The weights of the first principal component were subjected to Normal mixture modelling allowing the estimation of a gene’s contribution to the Bos taurus-Bos indicus axis. We used deviation from HWE, contribution to Bos indicus content and association to fertility traits to select 1,284 genes. With this set, we developed a co-heterozygosity network where the group of genes annotated as fertility-related had significantly higher Bos indicus content compared to other functional classes of genes, while the group of genes associated with milk production had significantly higher Bos taurus content. The network analysis resulted in capturing novel gene associations of relevance to bovine domestication events. We report transcription factors that are likely to regulate genes associated with cattle domestication and tropical adaptation. Our pipeline can be generalized to any scenarios where population structure requires scrutiny at the molecular level, particularly in the presence of a priori set of genes known to impact a phenotype of evolutionary interest such as fertility.

Novel SNPs in IL-17F and IL-17A genes associated with somatic cell count in Chinese Holstein and Inner-Mongolia Sanhe cattle

Background

Bovine mastitis is the most common and costly disease of lactating cattle worldwide. Apart from milk somatic cell count (SCC) and somatic cell score (SCS), serum cytokines such as interleukin-17 (IL-17) and interleukin-4 (IL-4) may also be potential indicators for bovine mastitis. The present study was designed to investigate the effects of single nucleotide polymorphisms (SNPs) in bovine IL-17F and IL-17A genes on SCC, SCS and serum cytokines in Chinese Holstein and Inner-Mongolia Sanhe cattle, and to compare the mRNA expression variations of the cows with different genotypes.

Results

A total of 464 lactating cows (337 Holstein and 127 Inner-Mongolia Sanhe cattle) were screened for SNPs identification and the data were analyzed using fixed effects of herd, parity, season and year of calving by general linear model procedure. The results revealed that SNP g.24392436C > T in IL-17F and SNP g.24345410A > G in IL-17A showed significant effects on SCC and IL-4 in Holstein (n = 337) and on IL-17 and IL-4 in Sanhe cattle (n = 127). The homozygous GG genotype of SNP g.24345410A > G had significantly higher mRNA expression compared with the heterozygous AG genotype.

Conclusions

The results indicate that IL-17F and IL-17A could be powerful candidate genes of mastitis resistance and the significant SNPs might be useful genetic markers against mastitis in both dairy and dual purpose cattle.

Electronic supplementary material

The online version of this article (doi:10.1186/s40104-016-0137-1) contains supplementary material, which is available to authorized users.

Designing of an artificial neural network model to evaluate the association of three combined Y-specific microsatellite loci on the actual and predicted postthaw motility in crossbred bull semen

The freezing of bull semen significantly hamper the motility of sperm which reduces the conception rate in dairy cattle. The prediction of postthaw motility (PTM) before freezing will be useful to take the decision on discarding or freezing of the germplasm. The artificial neural network (ANN) methodology found to be useful in prediction and classification problems related to animal science, and hence, the present study was undertaken to compare the efficiency of ANN in prediction of PTM on the basis of the number of ejaculates, volume, and concentration of sperms. The combined effect of Y-specific microsatellite alleles on the actual and predicted PTM was also studied. The results revealed that the prediction accuracy of PTM based on the semen quality parameters was comparatively lower because of higher variability in the data set. The ANN gave better prediction accuracy (34.88%) than the multiple regression analysis models (32.04%). The root mean square error was lower for ANN (8.4353) than that in the multiple regression analysis (8.6168). The haplotype or combined effect of microsatellite alleles on actual and predicted PTM was found to be highly significant (P < 0.01). On the basis of results, it was concluded that the ANN methodology can be used for prediction of PTM in crossbred bulls.

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 of MDR1 gene polymorphisms with susceptibility to hepatocellular carcinoma in the Chinese population

OBJECTIVE

The objective of this study was to evaluate the association of MDR1 gene polymorphisms with susceptibility to hepatocellular carcinoma (HCC).

METHODS

A total of 689 HCC patients and 680 cancer-free subjects were enrolled. Human MDR1 gene polymorphisms were investigated by created restriction site- polymerase chain reaction (CRS-PCR) and DNA sequencing methods. Multiple logistic regression models were applied to estimate the association between MDR1 gene polymorphisms and susceptibility to HCC.

RESULTS

We detected a novel c.4125A>C polymorphism and our findings suggested that this variant was significantly associated with susceptibility to HCC. A significantly increased susceptibility to HCC was noted in the homozygote comparison (CC versus AA: OR=1.621, 95% CI 1.143-2.300, χ2=7.4095, P=0.0065), recessive model (CC versus AC+AA: OR=1.625, 95% CI 1.167-2.264, χ2=8.3544, P=0.0039) and allele contrast (C versus A: OR=1.185, 95% CI 1.011-1.389, χ2=4.4046, P=0.0358). However, no significant increase was observed in the heterozygote comparison (AC versus AA: OR=0.995, 95% CI 0.794-1.248, χ2=0.0017, P=0.9672) and dominant model (CC+AC versus AA: OR=1.106, 95% CI 0.894-1.369, χ2=0.8560, P=0.3549).

CONCLUSIONS

These findings suggest that the c.4125A>C polymorphism of the MDR1 gene might contribute to susceptibility to HCC in the Chinese population. Further work will be necessary to clarify the relationship between the c.4125A>C polymorphism and susceptibility to HCC on larger populations of diverse ethnicity.