Polymerase Chain Reaction-polyacrylamide Gel Electrophoresis Research Articles

An indel polymorphism in the 3' untranslated region of HMGB1 confers risk for hepatocellular carcinoma by regulating HMGB1 transcriptional activity in a Chinese population.

The present study aimed to assess the association of rs34000982 polymorphism located in the 3'untranslated region (3'UTR) of high mobility group box 1 (HMGB1) gene and the risk of hepatocellular carcinoma (HCC), and further to explore the underlying mechanism. Genomic DNA was extracted from peripheral blood of 320 patients with HCC and 360 matched controls. Rs34000982 polymorphism was genotyped by a polymerase chain reaction-polyacrylamide gel electrophoresis assay. The genotype-phenotype association of HMGB1 mRNA and protein expression in HCC tissues with different genotypes was detected by quantitative (q) PCR assay and western blot. Vectors containing the insertion (ins)/ins or deletion (del)/del genotype of the rs34000982 polymorphism were constructed and the HMGB1 transcriptional activity affected by the rs34000982 polymorphism was detected by the luciferase assay. It was identified that the ins/ins genotype of rs34000982 significantly increased the risk of HCC compared with the del/del genotype. Further the qPCR results demonstrated that the HMGB1 mRNA expression level in HCC tissues with ins/ins genotype was 2.24 times that of HCC tissues with ins/del and del/del genotypes and there was a similar trend at protein level. In addition, the insertion allele of rs34000982 disturbed the binding of miR-636 with the 3'UTR of HMGB1, thereby increasing HMGB1 transcriptional activity in vitro. These data suggest that the rs34000982 polymorphism may contribute to HCC susceptibility, in full or at least partially through the effect on HMGB1 transcriptional activity by disturbing the binding of miR-636 with the 3'UTR of HMGB1.

An indel polymorphism in the 3' untranslated region of JAK1 confers risk for hepatocellular carcinoma possibly by regulating JAK1 transcriptional activity in a Chinese population.

The purpose of the present study was to assess whether the rs112395617 polymorphism located in the Janus kinase 1 (JAK1) 3' untranslated region (3' UTR) was associated with the risk of hepatocellular carcinoma (HCC), and to explore the potential mechanism of action. Genomic DNA was extracted from peripheral blood of 290 patients with HCC and 320 controls. A polymerase chain reaction-polyacrylamide gel electrophoresis assay was used to genotype the rs112395617 polymorphism. Quantitative (q)PCR was used to detect the genotype-phenotype association between HCC tissues and different genotypes. Vectors containing the insertion (ins)/ins or deletion (del)/del genotype of the rs112395617 polymorphism were constructed, and the luciferase assay was used to detect the JAK1 transcriptional activity affected by the rs112395617 polymorphism. It was identified that, when compared with the ins/ins genotype, the del/del and del/ins genotypes of rs112395617 were significantly associated with a decreased risk of HCC. The qPCR results demonstrated that the JAK1 mRNA expression level with ins/ins and ins/del genotypes was increased by 3.36 and 1.75-fold compared with the del/del genotype in human HCC tissue samples. In addition, the 'AATT' insertion allele of rs112395617 disrupted the binding site for microRNA (miR)-431-5p, thereby increasing JAK1 transcription in vitro. These data suggest that the rs112395617 polymorphism may contribute to HCC susceptibility, in full or at least partially through an effect on JAK1 transcriptional activity by disrupting its binding with miR-431-5p.

Genetic linkage Analysis of DFNB1)GJB6 (and DFNB4 (SLC26A4) loci with Autosomal Recessive Non-Syndromic Hearing Loss (ARNSHL) in Kermanshah, a western province of Iran

Background: Hearing Loss (HL) is the most common sensory disorder in human with an incidence of about one in 650 alive neonates. It is estimated that at least 50% of pre-lingual HL has a genetic basis. Almost 70% of genetic HL are non-syndromic (NSHL) and of NSHL cases, the autosomal recessive form (ARNSHL) comprises about 80%. Iranian population especially the Kurdish ethnicity with high consanguinity rate offers suitable opportunity for the study of ARNSHL. The aim of this study was to clarify the role of DFNB1 ( GJB6 ) and DFNB4 ( SLC26A4 ) loci in ARNSHL in Kermanshah, Iran. Methods : DFNB1 ( GJB6 ) and DFNB4 ( SLC26A4 ) loci were analysed in a cohort study on 28 ARNSHL families ( GJB2 - negative) from Kermanshah province in Iran. Genetic linkage analysis was applied on 140 samples from 140 individuals by polymerase chain reaction – polyacrylamide gel electrophoresis (PCR-PAGE) technique. Silver staining was used for visualizing the bands. At least, two informative screening markers were analyzed for each locus. Haplotypes were analyzed to determine linkage. Results: None of the families studied showed linkage to DFNB1 and DFNB4 loci. Conclusions : Our experiment, similar to previous studies, imply the absence of GJB6 mutations in Iran. None of the families showed linkage to DFNB4 locus. As it normally ranks second after DFNB1 in Iran and other parts of the world, more studies are warranted on more families to elucidate the role of this locus as well as other loci in etiogy of ARNSHL.

Association of genetic variations in RTN4 3'-UTR with risk for clear cell renal cell carcinoma.

Nogo proteins play an important role in the apoptosis of cells, especially in tumor cells. The present study was conducted to evaluate whether the TATC (rs71682980) and CAA (rs34917480) insertion/deletion polymorphisms of RTN4 3'-UTR are associated with clear cell renal cell carcinoma (ccRCC). These two polymorphisms were genotyped in 308 ccRCC patients and 466 healthy controls by polymerase chain reaction polyacrylamide gel electrophoresis (PCR-PAGE). Significantly reduced ccRCC risk was observed to be associated with the TATCins/ins genotype carriers (Versus TATCdel/del: adjusted OR 0.53, 95% CI 0.32-0.87, P = 0.022; Versus TATCdel/del-del/ins: adjusted OR 0.57, 95% CI 0.36-0.92, P = 0.017). After performing stratification analysis, the frequency of TATCins/ins genotype was observed to be significantly higher in patients with N0 compared the patients with N1 (P = 0.003). The present study provide evidence for the first time that the TATC insertion/deletion polymorphism in RTN4 3'-UTR may contributes to ccRCC risk in Chinese Han population.

Association of FoxP3 rs3761548 polymorphism with susceptibility to colorectal cancer in the Chinese population.

The aim of the present study was to determine the association of the Forkhead box P3 (FoxP3) rs3761548 polymorphism with the risk of colorectal cancer (CRC). Polymorphism genotyping was detected with polymerase chain reaction-polyacrylamide gel electrophoresis (PCR-PAGE), and data revealed that the AA, AC, and the combined A variant genotype (AA+AC) conferred a significantly greater risk of CRC [OR (95% CI) = 2.806 (1.726-4.563), 1.54 (1.121-2.11), and 1.797 (1.344-2.404), respectively]. Moreover, the A allele of rs3761548 was observed to be associated with higher susceptibility of CRC [OR (95% CI) = 1.792 (1.424-2.254)]. Unfortunately, no significant association was observed between the two subgroups after stratification by clinical characteristics including age; gender; tumor size, growth pattern, or differentiation; lymph node metastasis; and TNM pathological stage. Thus, we concluded that the FoxP3 gene polymorphism contributes to CRC susceptibility in a Chinese population.

Association of an insertion/deletion polymorphism in IL1A 3′-UTR with risk for cervical carcinoma in Chinese Han Women

Emerging evidence has demonstrated that polymorphisms of interleukin-1 (IL-1) may be involved in human tumorigenesis by regulating the production of this cytokine. Previous studies have investigated the association between two genetic variants (rs3783553 and rs17561) of IL1A and many diseases. The present study was conducted to evaluate whether these two variants are associated with cervical carcinoma (CC). These two polymorphisms were genotyped in 319 CC patients and 424 healthy controls by polymerase chain reaction polyacrylamide gel electrophoresis (PCR-PAGE) and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Significantly reduced CC risk was observed to be associated with the insertion allele of rs3783553 (P=0.014, OR=0.71, 95% CI=0.57–0.88). Stratification analysis based on different certain clinical features showed that patients with the heterozygous genotype were associated with a reduced predisposition advancing to clinical stage II-III or developing non-squamous cell carcinoma. Furthermore, patients with the insertion homozygous genotype were also associated with a reduced risk to have a poor tumor differentiation. No significant association was observed between rs17561 and CC. The present study provided evidence that the rs3783553 in IL1A 3′-UTR is inversely associated with CC risk, suggesting an important role IL-1α may play in cervical carcinogenesis.

FOXP3 genetic variant and risk of acute coronary syndrome in Chinese Han population

Coronary artery disease is the most common type of heart disease and a leading cause of morbidity and mortality all over the world. Acute coronary syndrome (ACS) is the most serious form of coronary artery disease. Recently, many studies indicated that genetic susceptibility may play a vital role in the pathogenesis of coronary heart disease including ACS. Forkhead/winged helix transcription factor (FOXP3) gene polymorphisms have been previously found to be associated with inflammatory diseases. To determine whether FOXP3 polymorphisms are associated with ACS, we examined the single nucleotide polymorphism rs3761548 of FOXP3 gene by polymerase chain reaction-polyacrylamide gel electrophoresis in 226 ACS patients and 259 unrelated healthy subjects. Our results showed that single nucleotide polymorphism rs3761548 had association with ACS in Chinese Han population. These data indicate that, for the first time, FOXP3 gene polymorphism may appear to play an important role in the susceptibility of ACS in Chinese Han population.

Genetic Variation in RTN4 3′-UTR and Susceptibility to Cervical Squamous Cell Carcinoma

Recent studies have suggested that RTN4 is a multifunctional gene, including inhibition of axonal regeneration, vascular remodeling, apoptosis, and tumor suppression. The TATC and CAA insertion/deletion polymorphisms of RTN4 3'-UTR have been linked to schizophrenia, depression, and dilated cardiomyopathy. To test whether these two polymorphisms are associated with cervical squamous cell carcinoma (CSCC), in this research, by using polymerase chain reaction-polyacrylamide gel electrophoresis, we determined the genotypes of the TATC and CAA polymorphisms in 336 CSCC patients and 450 unrelated control subjects. Allele frequencies of TATC and CAA polymorphisms were not significantly different between CSCC patients and control subjects (odds ratio [OR]=1.22, 95% confidence interval [CI]=0.98-1.50 for TATC; OR=0.95, 95% CI=0.76-1.18 for CAA). Decreased CSCC risk was associated with TATC polymorphism in a recessive model (OR=0.49, 95% CI=0.30-0.77), while no significant association was observed between CAA polymorphism and CSCC in different genetic models. Results of stratified analysis revealed that both TATC and CAA polymorphisms were associated with high clinical stage, and CAA polymorphism was also associated with positive parametrial invasion (OR=0.69, 95% CI=0.48-0.98). The present study provides evidence that TATC and CAA insertion/deletion polymorphisms are associated with CSCC, indicating that genetic variation in RTN4 3'-UTR contributes to the susceptibility to CSCC. It is necessary to confirm these findings in ethnically different populations and with a larger sample.

RNT4 3′-UTR Insertion/Deletion Polymorphisms Are Not Associated with Atrial Septal Defect in Chinese Han Population: A Brief Communication

Atrial septal defect (ASD) is a common type of congenital heart disease, which is defined as any communication through atrial septum. Several studies have revealed that genetic factors may influence the susceptibility of ASD. Recent studies have shown that reticulon 4 (RTN4) gene might be involved in some processes relevant to heart development, such as regulation of cell migration and vascular remodeling. This study aimed to evaluate RTN4 gene polymorphisms of CAA and TATC insertion/deletion in relation to the risk of ASD in Chinese Han population. A total of 175 ASD patients and 308 unrelated healthy controls were successfully investigated. The polymorphisms of patients were determined by polymerase chain reaction-polyacrylamide gel electrophoresis. There was no significant difference in the allele frequencies of CAA and TATC insertion/deletion in RNT4 gene between ASD patients and controls. The same results were seen in their genotypes. The present study suggests that CAA and TATC insertion/deletion polymorphisms of RNT4 gene may not be a useful marker to predict the susceptibility of ASD in Chinese Han population.

Fragile X CGG Repeat Variation in Tamil Nadu, South India: A Comparison of Radioactive and Methylation-Specific Polymerase Chain Reaction in CGG Repeat Sizing

Fragile X syndrome is the most frequent hereditary cause of mental retardation after Down syndrome. Expansion of CGG repeats in the 5' UTR of the fragile X mental retardation gene 1 (FMR1) causes gene inactivation in most of the cases. The FMR1 gene is classified into normal 5-44; gray zone 45-54; premutation 55 to <200; and full mutation ≥ 00 repeats. Precise sizing of FMR1 alleles is important to understand their variation, predisposition, and for genetic counseling. Meta-analysis reveals prevalence of premutation carriers as 1 in 259. No such reports are available in India. About 705 women from Tamil Nadu, South India, were screened for the FMR1 allelic variation by using radioactive polymerase chain reaction-polyacrylamide gel electrophoresis (PAGE) analysis. The women who were homozygous by radioactive polymerase chain reaction (rPCR) were reanalyzed by methylation-specific polymerase chain reaction (Ms-PCR) and GeneScan analysis. The techniques were validated and compared to arrive at a correction factor. Among 122 genotypes, 35 repeat variants ranging in size from 16 to 57 were observed. The most common repeat is 30 followed by 29. One in 353 women carried the premutation. No full mutations were observed. Screening populations with low frequency of premutations may not be applicable. Ms-PCR is more suitable for routine screening and clinical testing compared with rPCR-PAGE analysis.

NFKB1−94 Insertion/Deletion ATTG Polymorphism Contributes to Risk of Systemic Lupus Erythematosus

Growing evidence has shown that nuclear factor-κB (NF-κB) plays a key role in the initiation and progression of systemic lupus erythematosus (SLE) pathogenesis. A common polymorphism (-94 insertion/deletion ATTG, rs28362491) in the promoter region of NFKB1 gene was identified as functional. The -94del ATTG allele exhibited loss of binding to nuclear proteins and resulted in reduced promoter activity. We investigated the association between NFKB1 -94 insertion/deletion ATTG polymorphism and risk of SLE. A total of 224 SLE patients and 256 control subjects were genotyped using a polymerase chain reaction-polyacrylamide gel electrophoresis strategy and DNA sequencing. We found that the ATTG(1)/ATTG(2) genotype was associated with a significantly decreased risk of SLE (odds ratio=0.52, 95% confidence interval: 0.32-0.87, p=0.012). This finding indicates that the -94 insertion/deletion ATTG polymorphism may play pivotal roles in the development of SLE in the Chinese population. Further studies with larger sample size are warranted to confirm this finding, especially in different populations.

Analysis of RTN4 3′UTR Insertion/Deletion Polymorphisms in Ventricular Septal Defect in a Chinese Han Population

Congenital heart disease is the most common type of birth defect and the leading cause of infant mortality in the first year of life. Ventricular septal defect (VSD) is one of the most general congenital heart defects and is a defect in the wall between the right and left ventricles of the heart. The pathogenesis of VSD has been extensively investigated for many years, but it remains uncertain. To determine whether reticulon 4 gene (RTN4) 3'UTR insertion/deletion polymorphisms are associated with VSD, we genotyped the TATC and CAA insertion/deletion polymorphisms of RTN4 by polymerase chain reaction-polyacrylamide gel electrophoresis in 151 VSD patients and 308 unrelated healthy subjects in a Chinese Han population. No significant differences in 3'UTR TATC and CAA insertion/deletion polymorphisms genotype and allele frequencies were observed between the VSD and controls. These data indicate that, for the first time, RTN4 3'UTR insertion/deletion polymorphisms may not appear to play a role in the susceptibility of VSD in Chinese Han population.

VNTR polymorphism in intron 4 of the eNOS gene and the risk of ischemic stroke in a South Indian population

Ischemic stroke is a leading cause of death throughout the world. An increasing number of studies have suggested that genetic factors are important in the stroke risk. The aim of our study was to investigate whether the Variable Number of Tandem Repeats (VNTR) polymorphism in intron 4 of the endothelial nitric oxide synthase (eNOS) gene is associated with ischemic stroke in a South Indian population. 357 patients and 283 controls were enrolled in this case–control study. The ischemic stroke patients were classified according to TOAST classification. The eNOS gene polymorphism was determined by polymerase chain reaction–polyacrylamide gel electrophoresis. The genotypes were confirmed by sequencing the PCR products. There were significant differences in the genotype and allele frequencies of eNOS polymorphism between the patients with ischemic stroke and healthy controls ( p = 0.000). Multiple logistic regression analysis with forward stepwise selection using the potential confounders (sex, age, diabetes, hypertension, smoking and alcoholism) and eNOS gene variant revealed that the VNTR polymorphism in intron 4 of the eNOS gene is significantly [adjusted odds ratio = 6.23, 95%CI (4.30–9.29), p = 0.000] associated with ischemic stroke in the South Indian population from Andhra Pradesh. We did not find significant association of this polymorphism with any specific stroke subtype. Further hypertensives bearing 4a allele in high frequency are more predisposed to stroke.

A Functional Promoter Polymorphism inNFKB1Increases Susceptibility to Endometriosis

Numerous proinflammatory cytokines, such as TNFalpha and IL-6, which are nuclear factor kappaB (NF-kappaB) target genes, have been shown to promote proliferation in endometriotic cells, and several other genes involved in promoting growth are also NF-kappaB target genes. The aim of this study was to investigate whether the functional insertion/deletion polymorphism (-94 insertion/deletion ATTG) in the promoter of nuclear factor kappaB gene (NFKB1) is associated with susceptibility to endometriosis. Polymerase chain reaction-polyacrylamide gel electrophoresis method was used to genotype the NFKB1 -94 insertion/deletion ATTG polymorphism in 206 women with endometriosis and 365 ethnicity-matched healthy control women. The genotyping method was confirmed by the DNA sequencing analysis. Genotype at the -94 insertion/deletion ATTG polymorphism in the NFKB1 promoter was in Hardy-Weinberg equilibrium in either case or control subjects. The frequency of the ATTG(2)/ATTG(2) genotype and ATTG(2) allele in the endometriosis was significantly higher than that of control subjects (59.7% vs. 37%, odds ratio = 3.069, p < 0.001 for ATTG(2)/ATTG(2) genotype; 75.2% vs. 59.7%, odds ratio = 2.049, p < 0.001 for ATTG(2) allele), indicating that the -94 insertion/deletion ATTG polymorphism in the NFKB1 promoter was associated with endometriosis. This study suggests that the functional -94 insertion/deletion ATTG polymorphism in the promoter of NFKB1 is associated with an increased risk for endometriosis.

The genetic polymorphisms of 6 short tandem repeat loci in native Han population in Jiangxi province

To investigate the genetic polymorphisms of 6 short tandem repeats (STR) loci, namely, D6S1043, D2S1772, D7S3048, D22-GATA198B05, D8S1132 and D11S2368 in native Han population of Jiangxi province, China. Two hundred and twelve blood samples of unrelated subjects of Han population in Jiangxi province were collected. Genotyping was performed by using multiplex polymerase chain reaction-polyacrylamide gel electrophoresis. Thirteen alleles and 52 genotypes in the D6S1043 locus, 13 alleles and 66 genotypes in D2S1772, 12 alleles and 48 genotypes in D7S3048, 11 alleles and 44 genotypes in D22-GATA198B05, 10 alleles and 38 genotypes in D8S1132, 10 alleles and 41 genotypes in D11S2368 locus, were detected in the 212 subjects. The observed heterozygosity (h) in D6S1043, D2S1772, D7S3048, D22-GATA198B05, D8S1132 and D11S2368 loci ranged from 0.8019 to 0.8774. The expected heterozygosity (H) varied from 0.8553 to 0.8896. The discriminating power (DP) ranged from 0.9559 to 0.9735. The probability of exclusion (PE) ranged from 0.7053 to 0.7751. The polymorphism information content (PIC) varied from 0.8452 to 0.8774. All the 6 loci were of Hardy-Weinberg equilibrium. The genetic polymorphism of the 6 STR loci in Han population of Jiangxi province was high. The allelic distribution data at the 6 loci are valuable in population study, individual identification and paternity test for this population.

A functional insertion/deletion polymorphism in the promoter region of the NFKB1 gene increases susceptibility for prostate cancer

Among men, cancers of the prostate, lung and bronchus, and colon and rectum account for about 50% of all newly diagnosed cancers, and prostate cancer alone accounts for about 25% of incident cases. Nuclear factor-κB (NF-κB)-activation plays a critical role in prostate cancer by NF-κB inhibitor kinase β pathway–mediated inflammatory-induced tumorigenesis. A functional insertion/deletion polymorphism (–94 insertion/deletion ATTG) in the promoter of the NFKB1 gene, which encodes the p50 subunit of NF-κB, was identified recently. A total of 117 prostate cancer patients and 143 control subjects were recruited in this study. The NFKB1 –94 insertion/deletion ATTG genotype was determined using polymerase chain reaction-polyacrylamide gel electrophoresis. The frequency of the ATTG 2 allele in prostate cancer patients was significantly higher than that in the controls (63.7 vs. 54.5%; P = 0.035, OR = 1.461). Prostate cancer patients with a history of prostatitis have a 2.275 times higher risk for prostate cancer, compared to the control group ( P = 0.001). The functional NFKB1 promoter polymorphism is associated with increased risk of prostate cancer.

POSSIBLE BIOCHEMICAL EVENTS CRITICALLY INVOLVED IN ACUTE RENAL CELL INJURY

INTRODUCTION AND OBJECTIVE: Among men, cancers of the prostate, lung and bronchus, and colon and rectum account for about 50% of all newly diagnosed cancers and prostate cancer alone accounts for about 25% of incident cases. Nuclear factorB (NFB) -activation plays a critical role in prostate cancer by NFB inhibitor kinase pathway mediated inflammatory-induced tumorigenesis. A functional insertion/ deletion polymorphism (-94 insertion/deletion ATTG) in the promoter of NFKB1 gene, which encodes the p50 subunit of NFB, was recently identified. METHODS: A total of 117 prostate cancer patients and 143 control subjects were recruited in this study. The NFKB1 -94 insertion/ deletion ATTG genotype was determined using polymerase chain reaction-polyacrylamide gel electrophoresis. RESULTS: The frequency of ATTG2 allele in prostate cancer patients was significantly higher than that in controls (63.7% vs. 54.5 P = 0.035, OR = 1.461). Prostate cancer patients with prostatitis history have 2.275 times higher risks for prostate cancer, compared to the control group (P = 0.001). CONCLUSIONS: The functional NFKB1 promoter polymorphism is associated with increased risk of prostate cancer.

Comprehensive loss of heterozygosity analysis and identification of a novel hotspot at 3p21 in salivary gland neoplasms

We sought to assess loss of heterozygosity (LOH) profiles of 3p, 6q, 8q, 10q, 12q, 13q, and 17p and to identify the tumor suppressor genes involved in salivary gland neoplasms. LOH analysis was performed using 26 microsatellite markers by polymerase chain reaction-polyacrylamide gel electrophoresis method in 20 benign and 6 malignant salivary gland tumors. Overall, LOH was detected in at least one informative locus in 18 of 20 (90%) of benign tumors and in all of 6 cases of malignant tumors. High LOH frequencies were revealed at the loci D3S1307 (22%, 3p26), D3S966 (41%, 3p21), D6S255 (27%, 6q25), D8S166 (25%, 8q12), D8S199 (21%, 8q24), and D10S1765 (28%, 10q23) in benign tumors, defining the hotspot regions for putative tumor suppressor genes. The hotspot regions defined by the present study suggest that new tumor suppressor genes related to the development of salivary gland tumors may reside at several chromosomal loci, including loci at 3p, 6q, 8q and 10q.

Influence of thymidylate synthase gene polymorphisms on the survival of colorectal cancer patients receiving adjuvant 5-fluorouracil

The present study aimed to prospectively investigate the influence of thymidylate synthase (TS) polymorphisms (5'-TSER, 3'-TSUTR) on the disease-free survival (DFS) and overall survival (OS) of patients with colorectal cancer (CRC) who were treated with adjuvant 5-fluorouracil (5-FU) therapy. Patients were followed up for 19+/-14 months (median+/-SD). TS genotypes were determined from the peripheral blood mononuclear cells of 166 patients by polymerase chain reaction-polyacrylamide gel electrophoresis and restriction fragment length polymorphism methods. 5'-TSER 3R homozygotes showed significantly longer DFS (P = 0.048) and OS (P = 0.009). The 5'-TSER and 3'-TSUTR genotype combination groups showed a significant difference for DFS (P = 0.039) and OS (P = 0.029). Significantly better DFS (P = 0.049) and OS (P = 0.043) were observed for 6 bp/6 bp genotypes in 5'-TSER heterozygotes (n = 80). Based on this, and on hazard ratios obtained by Cox regression analysis of the DFS of genotype-combinations, the patients were classified as belonging to prognostic groups A and B. The DFS and OS of these two groups showed a highly significant difference (P = 0.002 and 0.001). In the multivariate Cox regression model, beside tumour location, the prognostic classification (groups A and B) proved to be an independent prognostic factor. Our data suggest that those TS genotypes and their combinations (group A: 3R/3R with any 3'-TSUTR genotype and 2R/3R with 6 bp/6 bp), which have been reported earlier as having high TS expression, predict significantly longer DFS and OS. We found that a combination of germline TS polymorphisms is an independent prognostic marker in selecting CRC patients with worse prognosis, and it may be worthwhile to examine whether these patients would benefit from an alternative therapy.

Pentanucleotide TTTTA repeat polymorphism of apolipoprotein(a) gene and plasma lipoprotein(a) are associated with ischemic and hemorrhagic stroke in Chinese: a multicenter case-control study in China.

It is still inconclusive whether high plasma lipoprotein(a) [Lp(a)] level is a risk factor for stroke. Small sample size and different ethnic groups and methodologies might be contributors to the conflicts in study results. The purpose of the present study was to investigate the association between plasma Lp(a) levels, pentanucleotide TTTTA repeat (PNTR) polymorphism of the apolipoprotein(a) [apo(a)] gene, and Chinese stroke in a case-control study. We recruited 1825 cases with stroke (44.3% cerebral atherothrombosis, 28.3% lacunar infarction, and 27.3% intracerebral hemorrhage) and 1817 controls from 7 centers in China. Lp(a) concentrations were quantified by enzyme-linked immunosorbent assay. The PNTR polymorphism of the apo(a) gene was determined by polymerase chain reaction-polyacrylamide gel electrophoresis. Conditional multivariate logistic regression analysis was used to identify independent risk factors for stroke and its subtypes. Lp(a) levels were significantly higher in cases than in controls (median, 28.5 versus 23.1 mg/dL; P<0.001), leading to a 1.97-fold (95% CI, 1.64 to 2.37) increase in risk for overall stroke, 2.0-fold (95% CI, 1.59 to 2.52) increase for atherothrombotic type, 2.05-fold increase (95% CI, 1.59 to 2.63) for lacunar type, and 1.64-fold increase (95% CI, 1.21 to 2.21) for hemorrhagic type. The number of PNTR negatively correlated with Lp(a) levels. Low-number repeats (sum of both alleles <16) of apo(a) PNTR were associated with both atherothrombotic stroke (odds ratio, 1.41; 95% CI, 1.04 to 1.91) and hemorrhagic stroke (odds ratio, 1.62; 95% CI, 1.09 to 2.37). Our results indicate for the first time that low numbers of apo(a) PNTR and plasma Lp(a) levels are independently associated with both ischemic and hemorrhagic stroke in Chinese.