Klotho gene polymorphisms are related to colorectal cancer susceptibility

Aim: The purpose of this study was to investigate the relationship of Klotho gene G-395A and C1818T polymorphisms with colorectal cancer (CRC) susceptibility. Methods: 125 CRC patients and 125 controls were enrolled in the study. G-395A and C1818T polymorphisms were genotyped with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technology. Haploview software was utilized to conduct linkage disequilibrium and haplotype analysis. Odds ratio (OR) and 95% confidence interval (95% CI) were used to analyze the correlation of genotypes and haplotypes with CRC susceptibility. Results: AA and GA genotypes of G-395A polymorphisms were related with CRC risk (AA: OR = 4.161, 95% CI = 1.437-12.053; GA: OR = 1.958, 95% CI = 1.133-3.385). The frequency of A allele was much higher in case group, compared with controls (31.2% vs.17.6%) and the value of OR AND 95% CI suggested that A allele served as a risk factor for CRC (OR = 2.123, 95% CI = 1.393-3.236). Haplotypes analysis indicated that A-C and A-T haplotypes were significantly associated with risk of CRC (OR = 1.822, 95% CI = 1.124-2.954; OR = 2.877, 95% CI = 1.340-6.176). Conclusion: G-395A polymorphism of Klotho gene could increase the risk of CRC.     

MTHFR polymorphisms and breast cancer risk

Introduction

Two functional single nucleotide polymorphisms (SNPs) in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene, C677T and A1298C, lead to decreased enzyme activity and affect chemosensitivity of tumour cells.

Material and methods

We evaluated these two common polymorphisms and breast cancer risk association in an Iranian sporadic breast cancer population-based case-control study of 294 breast cancer cases and 306 controls using a PCR-RFLP-based assay.

Results

Analyses of affected and controls show that homozygote genotype MTHFR 677CC has the highest frequency in both groups (28.3% in patients and 25.3% in control group). Genotype MTHFR 677CT and genotype MTHFR 1298AC were found to be statistically significant risk factors in our population (odds ratio: 1.6, 95% CI: 1.019-2.513, p = 0.041; and odds ratio: 2.575, 95% CI: 1.590-4.158, p = 0.001 respectively).

Conclusions

We can conclude based on the results of our study that a significant association between breast cancer and C677T and A1298C polymorphism might exist.     

CX3CR1 polymorphisms and the risk of age-related macular degeneration

Background: Age-related macular degeneration (AMD), a most common eye disease, can lead to irreversible visual impairment. Age, genetic and environmental factors have been implicated in AMD. Chemokine (C-X3-C motif) receptor 1 (CX3CR1) gene polymorphisms could influence the susceptibility of AMD. Methods: We tested the association between AMD and single nocleotide polymorphisms (SNPs) of CX3CR1 gene (rs3732378 and rs3732379) in 102 cases and 115 controls from China. Genotypes were determined by MassArray genotyping assay method. Association between CX3CR1 gene polymorphisms and AMD were examined by χ² test and logistic regression. Results: Genotype distribution of CX3CR1 gene polymorphisms were in accordance with HWE examination. No obvious differences were observed in the genotypes of rs3732378 polymorphism between case and control groups (P>0.05), but A allele of it could increase the risk of AMD (P=0.025, OR=2.391, 95% CI=1.092-5.237). Both TT genotype and T allele of rs3732379 were significantly associated with the susceptibility of AMD (P=8.663, OR=8.663, 95% CI=1.044-71.874; P=0.021, OR=2.076, 95% CI=1.104-3.903). Age, gender and smoking status were used as common confounders to adjust the association between CX3CR1 gene polymorphism and AMD risk. Then we found that rs3732378 had no obvious association with AMD susceptibility. TT genotype of rs3732379 related to the occurrence of AMD, but the association was not significant (P=0.050, OR=8.274, 95% CI=1.002-69.963). T allele of rs3732379 might increase the susceptibility of AMD (P=0.029, OR=2.033, 95% CI=1.077-3.838). Conclusion: T allele of rs3732379 might have a positive association with the susceptibility of AMD.     

ABCB1 polymorphisms associated with osteonecrosis of the femeral head

Aims: This case-control study was conducted to investigate the relation of ATP-binding cassette subfamily B member 1 (ABCB1) C1236T and C3435T polymorphisms and non-traumatic osteonecrosis of the femeral head (ONFH). Methods: We gathered 113 ONFH patients and 116 controls in the study. The polymorphisms of ABCB1 were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technology. Odds ratio (OR) with 95% confidence interval (CI) were adopted to analyze the correlation between ABCB1 polymorphisms and ONFH. Results: In the study, we found that the frequency of C3435T TT genotype was much lower in case group, compared with that of controls (17.7% vs. 23.3%). Moreover, OR and 95% CI values indicated that C3435T TT genotype served as a protective factor for ONFH (OR=0.34, 95% CI=0.15-0.75). Meanwhile, the risk for the T allele carriers was much lower than C allele (OR=0.60, 95% CI=0.42-0.87). However, C1236T polymorphism showed no significant effects on the pathogenesis of ONFH. In the haplotype analysis, T-T haplotype appeared to be an inhibitor for ONFH (OR=0.45, 95% CI=0.23-0.87). Conclusions: Based on the results, ABCB1 polymorphisms were associated with the risk for ONFH.     

Association between EGFR polymorphisms and the risk of lung cancer

Target: The study aimed to investigate the role of epidermal growth factor receptor (EGFR) rs6965469 and rs763317 polymorphisms in the occurrence and development of lung cancer. Methods: We used polymerase chain reaction-ligation detection reaction (PCR-LDR) method to detect the genotypes of EGFR rs6965469 and rs763317 polymorphisms and the data were analyzed by GeneMapper software. Odds ratios (ORs) with 95% confidence intervals (CIs) was calculated by χ² test to estimate the significance difference of genotype and allele frequencies in case and control groups. ORs and 95% CIs were adjusted by logistic regression analysis with age, gender, drinking and smoking. The genotypes distributions of control group were tested by Hardy-Weinberg equilibrium (HWE). Results: The genotypes frequencies of controls for rs6965469 and rs763317 polymorphims were consistent with HWE. The distribution of rs6965469 TT genotype in two groups was significantly different (P<0.05) and TT genotype was associated with an increased risk of lung cancer (OR=6.92, 95% CI=1.33-36.00). AA genotype and A allele of rs763317 were also the susceptible factors of lung cancer. Individuals with AA genotype or A allele were more likely to suffer lung cancer (AA vs. GG: OR=7.20, 95% CI=1.33-39.07; A vs. G: OR=2.61, 95% CI=1.04-6.59). Conclusions: The EGFR rs6965469 and rs763317 polymorphisms may be risk factors for lung cancer.     

MSH3 rs26279 polymorphism increases cancer risk: a meta-analysis

Previous studies have investigated the association of mutS homolog 3 (MSH3) rs26279 G > A polymorphism with the risk of different types of cancers including colorectal cancer, breast cancer, prostate cancer, bladder cancer, thyroid cancer, ovarian cancer and oesophageal cancer. However, its association with cancer remains conflicting. We performed a comprehensive meta-analysis to derive a more precise estimation of the relationship between MSH3 rs26279 G > A polymorphism and cancer susceptibility. Systematically searching the PubMed and EMBASE databases yielded 11 publications with 12 studies of 3282 cases and 6476 controls. The strength of the association was determined by crude odds ratios (OR) and 95% confidence intervals (CI). Overall, pooled risk estimates demonstrated that MSH3 rs26279 G > A was significantly associated with an increased overall cancer risk under all the genetic models (GG vs. AA: OR = 1.27, 95% CI = 1.09-1.48, P = 0.002; AG vs. AA: OR = 1.10, 95% CI = 1.00-1.21, P = 0.045; GG vs. AG + AA: OR = 1.23, 95% CI = 1.06-1.42, P = 0.005; AG + GG vs. AA: OR = 1.13, 95% CI = 1.04-1.24, P = 0.006; G vs. A: OR = 1.13, 95% CI = 1.05-1.20, P = 0.001). The association was more evident for colorectal cancer and breast cancer. Moreover, the significant association was also observed in the following subgroups: Europeans, Asians, population-based studies, hospital-based studies, and studies comprising relatively large sample size (≥ 200). Our meta-analysis results demonstrated that MSH3 rs26279 G > A polymorphism is associated with an increased risk of overall cancer, especially for the colorectal cancer and breast cancer.     

PPARG,AGTR1, CXCL16 and LGALS2 polymorphisms are correlated with the risk for coronary heart disease

Purpose: Our study was designed to explore the interaction between genes of PPARG, AGTR1, CXCL16 and LGALS2 and further investigate the association between genes polymorphisms and coronary heart disease (CHD). Methods: 90 CHD patients and 80 healthy individuals were enrolled in our study. Gene chip technology was used for checking four single nucleotide polymorphisms (SNPs) (PPARG rs1152002, AGTR1 rs5186, CXCL16 rs3744700 and LGALS2 rs7291467). MDR software was used to analyze gene-gene interactions. Odds ratio (OR) with 95% confidence interval (CI) were employed to evaluate the association of genes and CHD risk. Results: Genotypes and alleles distribution in case and control groups showed significant difference (P<0.05). And there exists interaction among genes. The model of PPARG×CXCL16 showed effects on the occurrence of CHD (OR=2.92, 95% CI=1.44-5.94). Meanwhile, the PPARG×AGTR1×CXCL16×LGALS2 model was associated with CHD susceptibility (OR=3.97, 95% CI=2.01-7.84). Moreover, we found that PPARG×LGALS2×CXCL16, was the best interaction model and it could significantly increase the risk for CHD (OR=3.37, 95% CI=1.71-6.63). Conclusion: PPARG rs1152002, AGTR1 rs5186, CXCL16 rs3744700 and LGALS2 rs7291467 polymorphisms may be closely related to the development of CHD. Moreover, there exist gene-gene interactions among these susceptibility genes.     

CTLA-4 gene polymorphisms and susceptibility to chronic obstructive pulmonary disease

Objective: The aim of this study was to investigate whether four single nucleotide polymorphisms (SNPs) in CTLA-4 gene are associated with chronic obstructive pulmonary disease (COPD) in a Chinese population. Methods: Samples were collected from a Chinese population and analyzed for the association of SNPs in CTLA-4 gene with COPD in a case-control study. Four SNPs (rs231775, rs3087243, rs231725, rs5742909) in CTLA-4 gene were chosen and genotyped. The results were then analyzed using statistical methods. Results: We found that none of these four SNPs (rs231775, rs3087243, rs231725, rs5742909) in CTLA-4 gene were associated with the disease. Conclusion: Our data suggested that there was no significant association between these four SNPs in CTLA-4 gene and COPD susceptibility in a Chinese population.     

RET/PTC rearrangement in thyroid tumors

Rearrangement of the RET gene, also known as RET/PTC rearrangement, is the most common genetic alteration identified to date in thyroid papillary carcinomas. The prevalence of RET/PTC in papillary carcinomas shows significant geographic variation and is approx 35% in North America. RET/PTC is more common in tumors in children and young adults, and in papillary carcinomas associated with radiation exposure. There are at least 10 different types of RET/PTC, all resulting from the fusion of the tyrosine kinase domain of RET to the 5′ portion of different genes. RET/PTC1 and RET/PTC3 are the most common types, accounting for >90% of all rearrangements. There is some evidence that different types of RET/PTC may be associated with distinct biologic properties of papillary carcinomas. RET/PTC1 tends to be more common in tumors with typical papillary growth and microcarcinomas and to have a more benign clinical course, whereas RET/PTC3 in some populations shows a strong correlation with the solid variant of papillary carcinoma and more aggressive tumor behavior. RET/PTC has recently been found in hyalinizing trabecular adenomas of the thyroid gland, providing molecular evidence in favor of this tumor to be a variant of papillary carcinoma. The occurrence of RET/PTC in Hashimoto thyroiditis and thyroid follicular adenomas and hyperplastic nodules reported in several studies has not been confirmed in other observations and remains controversial.     

CHRNA5 polymorphism and susceptibility to lung cancer in a Chinese population

Polymorphisms in the nicotinic acetylcholine receptor subunit CHRNA5 gene have been associated with lung cancer positive susceptibility in European and American populations. In the present hospital-based, case-control study, we determined whether polymorphism in rs503464 of CHRNA5 is associated with lung cancer risk in Chinese individuals. A single nucleotide polymorphism in CHRNA5 rs503464, c.-166T>A (hereafter T>A), was identified using TaqMan-MGB probes with sequencing via PCR in 600 lung cancer cases and 600 healthy individuals. Genotype frequencies for rs503464 (T>A) were in Hardy-Weinberg equilibrium for the control population. However, genotype frequencies were significantly different between cases and controls (P < 0.05), while allele frequencies were not significantly different between groups. Compared to homozygous genotypes (TT or AA), the risk of lung cancer in those with the heterozygous genotype (TA) was significantly lower (OR = 0.611, 95%CI = 0.486-0.768, P = 0.001). Using genotype AA as a reference, the risk of lung cancer for those with genotype TA was increased 1.5 times (OR = 1.496, 95%CI = 1.120-1.997, P = 0.006). However, no difference in risk was observed between T allele carriers and A allele carriers (OR = 0.914, 95%CI = 0.779-1.073, P = 0.270). Stratification analysis showed that the protective effect of TA was more pronounced in those younger than 60 years, nonsmokers, or those without a family history of cancer, as well as in patients with adenocarcinoma or squamous cell carcinoma in clinical stages III or IV (P < 0.05). Therefore, the heterozygous genotype c.-166T>A at rs503464 of CHRNA5 may be associated with reduced risk of lung cancer, thus representing a susceptibility allele in Chinese individuals.     

MicroRNA301 is a potential diagnostic biomarker for hepatocellular cancer

We explored microRNA301 diagnosis value in hepatocellular cancer (HCC), attempting to provide novel insights for early detection, effective prevention, and timely treatment. 42 patients with HCC and 38 controls composed of 9 liver cirrhosis (LC), 9 chronic hepatitis B (CHB) and 20 healthy individuals were investigated in the study. Serum microRNA301 expression levels were detected using fluorescent quantitative polymerase chain reaction (FQ-PCR) technology. ROC curve was performed to evaluate diagnosis value of microRNA301. Meanwhile, the correlations of microRNA301 levels with clinical characteristics were also analyzed. Significantly up-regulated expression of serum microRNA301 was seen in HCC patients compared with the controls (P < 0.05). We also noted that level changes of microRNA301 were associated with differentiation, alpha fetoprotein (AFP), portal vein-emboli and HasAg (P < 0.05), rather than age, gender and tumor size. Based on the area under ROC curve of 0.880, the critical value of microRNA301 was 2.3530 and the sensitivity and specificity were 88.1% and 70.3%, respectively. The results of this study revealed that microRNA301 might function as a potential diagnostic biomarker for HCC.     

CREB1 gene polymorphisms combined with environmental risk factors increase susceptibility to major depressive disorder (MDD)

Major depressive disorder (MDD) is one of the most severe psychiatric disorders. The objective of this study was to explore the effects of CREB1 gene polymorphisms on risk of developing MDD and the joint effects of gene-environment interactions. Genotyping was performed by Taqman allelic discrimination assay among 586 patients and 586 healthy controls. A significant impact on rs6740584 genotype distribution was found for childhood trauma (P = 0.015). We did not find an association of CREB1 polymorphisms with MDD susceptibility. However, we found a significantly increased risk associated with the interactions of CREB1 polymorphisms and drinking (OR = 11.67, 95% CI = 2.52-54.18; OR = 11.52, 95% CI = 2.55-51.95 for rs11904814; OR = 4.18, 95% CI = 1.87-9.38; OR = 5.02, 95% CI = 2.27-11.14 for rs6740584; OR = 7.58, 95% CI = 2.05-27.98; OR = 7.59, 95% CI = 2.12-27.14 for rs2553206; OR = 8.37, 95% CI = 3.02-23.23; OR = 7.84, 95% CI = 2.93-20.98 for rs2551941). We also noted that CREB polymorphisms combined with family harmony and childhood trauma conferred increased susceptibility for MDD. In conclusion, polymorphisms in the CREB gene may not be independently associated with MDD risk, but they are likely to confer increased susceptibility by interacting with environmental risk factors in the Chinese population.     

MTHFR 677 C>T and 1298 A>C polymorphisms and the age of onset of colorectal cancer in hereditary nonpolyposis colorectal cancer

Hereditary non-polyposis colorectal cancer (HNPCC) or Lynch syndrome is characterized by inactivating germline mutations in DNA mismatch repair genes resulting in an increased risk of developing an epithelial malignancy. There is considerable variability in disease expression observed in this syndrome, which is thought to be due to a combination of genetic and environmental factors. Alterations in the kinetics of methylene tetrahydrofolate reductase (MTHFR) due to the presence of polymorphisms in the MTHFR gene have been associated with an increased risk of colorectal cancer (CRC). Two common single nucleotide polymorphisms (SNPs) located within the MTHFR gene, 677 C>T and 1298 A>C, that alter the function of the encoded protein have been the focus of many studies on CRC risk outside the context of an inherited predisposition to disease. In this report, a total of 417 HNPCC participants were genotyped for the 677 C>T and 1298 A>C SNPs to determine whether there exists an association with the age of disease onset of CRC. Genotyping of both SNPs was performed by TaqMan® assay technology. Associations in disease risk were further investigated using Kaplan–Meier survival analysis and Cox hazard regression. The average ages of disease diagnosis were found to be different between individuals harbouring either one of the MTHFR polymorphisms. Both Kaplan–Meier and Cox hazard regression analyses revealed a more complex relationship between the two polymorphisms and the age of CRC onset. The Kaplan–Meier survival analysis revealed that compound heterozygotes for the two SNPs developed CRC 10 years later compared with those carrying only wild-type alleles.     

Correlation between LSP1 polymorphisms and the susceptibility to breast cancer

Objective: The present study aimed at assessing the relationship between Leukocyte-specific protein 1 gene (LSP1) polymorphisms (rs569550 and rs592373) and the pathogenesis of breast cancer (BC). Methods: 70 BC patients and 72 healthy subjects were enrolled in the study. Rs569550 and rs592373 polymorphisms were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Odds ratio (OR) with 95% confidence interval (CI) were calculated by the chi-squared test to assess the relationship between LSP1 polymorphisms and BC risk. Linkage disequilibrium (LD) and haplotypes were also analyzed by HaploView software. Results: Genotype distribution of the control was in accordance with Hardy-Weinberg equilibrium (HWE). The homozygous genotype TT and T allele of rs569550 could significantly increase the risk of BC (TT vs. GG: OR=3.17, 95% CI=1.23-8.91; T vs. G: OR=1.63, 95% CI=1.01-2.64). For rs592373, mutation homozygous genotype CC and C allele were significantly associated with BC susceptibility (CC vs. TT: OR=4.45, 95% CI=1.38-14.8; C vs. T: OR=1.70, 95% CI=1.03-2.81). LD and haplotypes analysis of rs569550 and rs592373 polymorphisms showed that T-C haplotype was a risk factor for BC (T-C vs. G-T: OR=1.74, 95% CI=1.04-2.92). Conclusion: LSP1 rs569550 and rs592373 polymorphisms are both risk factors for BC.     

Correlation between survivin genetic polymorphisms and lung cancer susceptibility

Aims: The purpose of the study was to analyze the relationship of survivin polymorphisms including -31G/C, -625G/C, 9194A/G and 9809T/C with the susceptibility to lung cancer. Methods: Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to test the polymorphisms of -31G/C, -625G/C, 9194A/G and 9809T/C in 104 patients with lung cancer and 104 healthy controls. Then, linkage disequilibrium and haplotypes were analyzed by HaploView software. The differences of genotype, allele and haplotype frequencies in case and control group were assessed via chi-square test. Odds ratio (OR) with 95% CI were used to evaluate the correlation of survivin polymorphisms with lung cancer. Results: Genotype distribution of each polymorphism site in control group was in agreement with Hardy-Weinberg equilibrium (HWE) (P>0.05). The frequency of -31G/C CC genotype and C allele in case group were much higher than that of controls, respectively (CC: 33.6% vs. 22.1%; C: 57.2% vs. 46.6%) and CC genotype as well as C allele were appeared to be risk factors for lung cancer. Meanwhile, 9194A/G GG genotype could increase the risk for lung cancer (OR=2.86, 95% CI=1.14-7.20). The risk of G allele carriers for lung caner was higher than that of A allele (OR=1.63, 95% CI=1.08-2.47). The haplotypes analysis indicated that CGGC and GCAT were associated with the susceptibility to lung cancer (OR=2.79, 95% CI=1.58-4.92; OR=2.36, 95% CI=1.29-4.30). Conclusions: Survivin -31G/C and 9194A/G polymorphisms were associated with the risk of lung cancer. The CGGC and GCAT haplotypes carriers were more likely to develop lung cancer.     

Relationship between hWAPL polymorphisms and cervical cancer susceptibility

Purpose: To analyze the correlation of the polymorphisms of human wing-apart like (hWAPL) gene (rs7083506 and rs11202058) with the susceptibility to cervical cancer. Besides, the relationship of haplotypes between the polymorphisms with cervical cancer susceptibility was analyzed. Methods: Taqman probe genotyping method was adopted to detect the genotype distribution of hWAPL rs7083506 and rs11202058 polymorphisms in 117 cervical cancer patients and 128 healthy controls. Linkage disequilibrium and haplotypes were analyzed by Haploview software. χ² test was utilized to analyze the differences of genotype, allele and haplotype frequencies between the case and control groups. Results: Correlation analysis of hWAPL rs7083506 and rs11202058 polymorphisms with cervical cancer susceptibility was based on the five genetic models. TT genotype of rs7083506 increased the susceptibility of cervical cancer in TT vs. CC model and TT vs. CT+TT model (OR=2.249, 95% CI=1.018-4.970; OR=2.287, 95% CI=1.069-4.896). For rs11202058, the A allele increased the cervical cancer susceptibility (A vs. G, OR=1.502, 95% CI=1.005-2.245). No significant correlation was observed between rs11202058 genotypes and cervical cancer susceptibility. We performed the haplotype analysis between the two polymorphisms, and found that T-A haplotype significantly correlated with cervical cancer, the susceptibility of cervical cancer increased to 1.78 times. Conclusions: Rs7083506 and rs11202058 polymorphisms of hWAPL and their haplotype T-A were associated with cervical cancer.     

Genotyping analysis of 3 RET polymorphisms demonstrates low somatic mutation rate in Chinese Hirschsprung disease patients

Background: Genetic mosaicism has been reported for both coding and non-coding sequences in the RET gene in Hirschsprung disease (HSCR) patients. This study aimed to investigate somatic mutation rate in Chinese population by comparing both homozygous genotype percentage and risk allele frequency of 3 RET single nucleotide polymorphisms (SNPs) among blood and colon samples. Methods: DNA was extracted from 59 HSCR blood samples, 59 control blood samples and 76 fresh frozen colon tissue samples (grouped into ganglionic, transitional and aganglionic level). Genotype status of rs2435357 and rs2506030 was examined by competitive allele specific hydrolysis probes (Taqman) PCR technology, and rs2506004 was examined by Sanger sequencing. Homozygous genotype percentage and risk allele frequency were calculated for each type of sample and compared by chi-square test. P<0.05 was regarded as being statistically significant. Results: Colon tissue DNA samples showed similar frequency of SNPs as that of the blood DNA samples in HSCR patients, both of which are significantly higher than the control blood group (rs2435357 TT genotype: 71.2%, 74.7% versus 22.0% in HSCR blood, HSCR colon and control blood DNA respectively, P=0.000; rs2506004 AA genotype: 72.4%, 83.1% versus 25.5%, P=0.000; rs2506030 GG genotype: 79.7%, 77.2% versus 54.2%, P=0.000 and 0.004). With respect to DNA extracted from ganglionic, transitional and aganglionic levels, no statistically significant difference was demonstrated in those 3 regions (rs2435357: P=0.897; rs2506004: P=0.740; rs2506030: P=0.901). Conclusion: Our data does not support the notion that high frequency of somatic changes as an underlying etiology of Chinese HSCR population.     

HOXD13 methylation status is a prognostic indicator in breast cancer

Homeobox protein Hox-D13 is encoded by HOXD13 gene which is frequently methylated in cancer and has been recognized as a tumor suppressor in pancreatic cancer. In this study, we examined HOXD13 mRNA expression in 40 pairs of breast cancers and corresponding normal breast tissues. Bisulfite sequencing of HOXD13 promoter was performed in 6 pairs of breast tumors and corresponding normal breast tissues to examine the potential HOXD13 CpG methylated sites. HOXD13 DNA methylation frequency analysis was performed using MethyLight in 196 pairs of breast cancers and corresponding normal breast samples. DNA methylation status and clinico-pathological features were investigated. Kaplan-Meier survival analysis and Cox proportional hazards models were utilized to assess the effect of methylation status on overall survival. We found that 60% (24/40) of breast cancers showed low HOXD13 mRNA expression when compared with corresponding normal breast tissue. The predicted CpG island was located in the -1325 bp to +675 bp region. Next, the -332 bp site in HOXD13 gene promoter was further examined and in 57.7% (113/196) samples methylation was detected at this site. HOXD13 methylation was correlated with larger tumor size (P = 0.004), but not with other clinico-pathological parameters. In addition, patients with methylated -HOXD13 promoter had worse overall survival (OS) (P = 0.005). Based on our results we conclude that HOXD13 methylation is a common event in primary breast cancer and is associated with poor survival of breast cancer patients. HOXD13 methylation could therefore potentially be used as a prognostic factor for breast cancer.     

MTHFR genetic polymorphism increases the risk of preterm delivery

Aims: This study aimed to investigate the association between the methylene tetrahydrofolate reductase (MTHFR) gene C677T and A1298C polymorphisms and premature delivery susceptibility. Methods: With matched age and gender, 108 premature delivery pregnant women as cases and 108 healthy pregnant women as controls were recruited in this case-control study. The cases and controls had same gestational weeks. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was adopted to analyze C677T and A1298C polymorphisms of the participants. Linkage disequilibrium (LD) and haplotype analysis were conducted by Haploview software. The differences for frequencies of gene type, allele and haplotypes in cases and controls were tested by chi-square test. The relevant risk of premature delivery was represented by odds ratios (ORs) with 95% confidence intervals (95% CIs). Results: TT gene type frequency of C677T polymorphsim was higher in cases than the controls (P=0.004, OR=3.077, 95% CI=1.469-6.447), so was allele T (P=0.002, OR=1.853, 95% CI=1.265-2.716). Whereas, CC gene type of A1298C polymorphism had a lower distribution in cases than the controls (P=0.008, OR=0.095, 95% CI=0.012-0.775), so was allele C (P=0.047, OR=0.610, 95% CI=0.384-0.970). Haplotype analysis and linkage disequilibrium test conducted on the alleles of two polymorphisms in MTHFR gene, we discovered that haplotype T-A had a higher distribution in cases, which indicated that susceptible haplotype T-A was the candidate factor for premature delivery. Conclusions: Gene type TT of MTHFR C677T polymorphism might make premature delivery risk rise while gene type CC of A1298C polymorphism might have protective influence on premature delivery.