Mutational analysis of FBXO7 gene in Parkinson's disease in a Taiwanese population

Mutations in the FBXO7 gene cause an autosomal-recessive early-onset parkinsonism with pyramidal tract signs. Its role in typical Parkinson's disease (PD) without pyramidal features is unclear. We assayed FBXO7 gene in 900 participants comprising 448 PD patients and 452 age- and sex-matched control subjects from Taiwan. The entire FBXO7 coding region and intron-exon boundaries were sequenced. We identified 2 novel missense substitutions, p.Ile87Thr and p.Asp328Arg, in a single heterozygous state in 2 early-onset PD patients individually (1.1% early-onset PD). These 2 variants were not observed in control subjects with a total of 904 normal alleles. Additionally, we also found 1 noncoding variant, exon 1 IVS-329C>T, modestly associated with PD. The frequency of the CT/TT genotype was higher in PD patients compared with control subjects (odds ratio, 1.43; 95% confidence interval, 1.02–2.01; p = 0.04). The clinical phenotypes of genetic variant carriers are similar to that seen in idiopathic PD. We conclude that FBXO7 gene contributes little to typical PD in our population. Further studies in other ethnic cohorts will be important to address its potential pathophysiological role in PD.     

Genetic polymorphisms of TP53-binding protein 1 (TP53BP1) gene and association with breast cancer risk

In the present study, we evaluated the association between the TP53BP1 Glu353Asp and T-885G polymorphisms and breast cancer risk as well as with the clinicopathological characteristics of the patients. Genotyping of these polymorphisms was performed on 387 breast cancer patients and 252 normal and healthy women who had no history of any malignancy using PCR-RFLP method in a hospital-based Malaysian population. Breast cancer risk was not observed among women who were heterozygous (OR(adj) = 0.887; 95% CI, 0.632-1.245) or homozygous (OR(adj) = 1.083; 95% CI, 0.595-1.969) for Asp allele, and those carriers of Asp allele (OR(adj) = 0.979; 95% CI, 0.771-1.243). Similarly, women who were TG heterozygotes (OR(adj) = 1.181; 95% CI, 0.842-1.658) or GG homozygotes (OR(adj) = 1.362; 95% CI, 0.746-2.486) and carriers of G allele (OR(adj) = 1.147; 95% CI, 0.903-1.458) were not associated with increased risk of breast cancer. Asp allele genotype was significantly associated with ER negativity (p = 0.0015) and poorly differentiated tumours (p = 0.008), but G allele genotype was not associated with the clinicopathological characteristics. In conclusion, Glu353Asp and T-885G polymorphic variants might not have an influence on breast cancer risk, thus might not be potential candidates for cancer susceptibility. Glu353Asp variant might be associated with tumour aggressiveness as defined by its association with ER negativity and poorly differentiated tumours.     

Toll-like receptor 4 Asp299Gly and Thr399Ile polymorphisms in gastric cancer of intestinal and diffuse histotypes

In the present study we investigated the potential role of Toll-like receptor 4 (TLR-4) Asp299Gly and Thr399Ile polymorphisms as risk factors in the development of gastric cancer. TLR-4 Asp299Gly and Thr399Ile polymorphisms were investigated in 171 Italian patients with sporadic gastric cancer and in 151 controls. Unconditional regression (odds ratio and 95% confidence intervals) were used to investigate the association of the studied polymorphisms with gastric cancer. TLR-4 Thr399Ile polymorphism is linked with an increased susceptibility to gastric cancer (P = 0.023 and hazard ratio = 3.62). No significant association for TLR-4 Asp299Gly polymorphism was found. In the subgroup of patients with intestinal-type gastric cancer, a significant risk of gastric cancer was associated with TLR-4 Thr399Ile genotype (P = 0.006). Our results demonstrated that TLR-4 Thr399Ile polymorphism is linked with an increased susceptibility to gastric cancer. An increased risk for intestinal gastric cancer in carriers of the TLR4 Thr399Ile allele was observed. Future epidemiological studies should consider the possible interactions between proinflammatory genotypes (such as TLR and interleukin-1R polymorphisms) and other risk factors for cancer such as dietary habits and/or exposure to environmental carcinogens.     

Toll-like receptor 4 gene polymorphisms and susceptibility to colorectal cancer: a meta-analysis and review

Introduction

Many case-control studies have investigated the association between toll-like receptor 4 (TLR4) Asp299Gly and Thr399Ile polymorphisms and risk of colorectal cancer (CRC). However, published data are still conflicting.

Material and methods

A systematic search was conducted in the electronic databases of PubMed, MEDLINE, EMBASE, Web of Science and CNKI between 2000 and 2014. The associations between TLR4 polymorphisms and CRC susceptibility were assessed by pooled odds ratios (ORs) and 95% confidence intervals (95% CI) in fixed or random effects models.

Results

In total nine case-control studies were identified in this meta-analysis. For TLR4 Asp299Gly polymorphism, 9 studies included 1198 cases and 1290 controls. The GG genotype carriers had higher risk for developing CRC than AA + GA genotype carriers (OR = 1.95, 95% CI: 1.00–3.77, p = 0.05). No association was found in other genetic models (p > 0.05). Analysis stratified by ethnicity showed no association in any genetic models among the Asian or Caucasian population. For TLR4 Thr399Ile polymorphism, 6 studies contained 619 cases and 632 controls. The overall analysis showed significantly increased risk in TT homozygote carriers compared to CC homozygote (OR = 4.99, 95% CI: 1.41–17.65, p = 0.01) and C carriers (TC + CC) (OR = 4.50, 95% CI: 1.27–15.87, p = 0.02). In terms of analyses stratified by race, a significant association was found in each genetic model among the Asian population, rather than the Caucasian group.

Conclusions

The GG homozygote carriers of TLR4 Asp299Gly and TT homozygote carriers of TLR4 Thr399Ile polymorphisms might be correlated with an increased risk of CRC, suggesting they may serve as genetic risk factors for CRC.     

Genetic polymorphism of p53, but not GSTP1, is association with susceptibility to esophageal cancer risk - A Meta-Analysis

A number of studies have evaluated two functional polymorphisms on p53 Arg72Pro and GSTP1 Ile105Val, in relation to esophageal cancer susceptibility. However, the results remain conflicting rather than conclusive. This meta-analysis on 2919 cases and 4074 controls for p53 Arg72Pro and 1885 cases and 2194 controls for GSTP1 Ile105Val from 13 published case-control studies showed that no significant general main effects for GSTP1 Ile105Val on esophageal cancer risk. However, we found that the p53 Arg72Pro was associated with an increased risk of esophageal cancer ((Pro/Arg +Pro/Pro) versus Arg/Arg: OR=1.20, 95%CI=1.06-1.36) without any between-study heterogeneity.In the stratified analysis by ethnicity, we found that the increased esophageal cancer risk associated with p53 Arg72Pro polymorphism was more evident in Asian group ((Pro/Arg +Pro/Pro) versus Arg/Arg: OR=1.35, 95%CI=1.14-1.60, P=0.09 for heterogeneity test), although we still failed to find any significant association between GSTP1 Ile105Val polymorphism and esophageal cancer risk in different ethnicity. These results suggest that p53 Arg72Pro polymorphism, but not GSTP1 Ile105Val, may contribute to esophageal cancer development, especially in Asian. Additional well-designed large studies were required for the validation of this association.     

Polymorphism of the homologous recombination repair genes RAD51 and XRCC3 in breast cancer

The RAD51 protein and its paralog, XRCC3, play an important role in the repair of DNA double-strand breaks (DSBs) by homologous recombination. Since DSBs may contribute to the pathogenesis of breast cancer and variability in DNA repair genes may be linked with some cancers, we performed a case-control study (135 cases and 175 controls) to check the association between the genotypes of the Thr241Met polymorphism of the XRCC3 gene and the 135G>C polymorphism of the RAD51 gene and breast cancer occurrence and progression. Genotypes were determined in peripheral blood lymphocytes by RFLP-PCR. We did not find any association between either polymorphism singly and breast cancer occurrence. Both polymorphisms were not related to tumor size, estrogen and progesterone receptors status, cancer type and grade. However, the Thr241Met genotype of the XRCC3 polymorphism slightly increased the risk of local metastasis in breast cancer patients (OR 2.56, 95% CI 1.27-5.17). The combined Thr241Met/135G>C genotype decreased the risk of breast cancer occurrence (OR 0.22, 95% CI 0.08-0.59). Our results suggest that the variability of the DNA homologous recombination repair genes RAD51 and XRCC3 may play a role in breast cancer occurrence and progression, but this role may be underlined by a mutual interaction between these genes.     

Roles of genetic variants in the PI3K/PTEN pathways in susceptibility to colorectal carcinoma and clinical outcomes treated with FOLFOX regimen

The genetic or abnormal activation of PI3K/PTEN signaling pathway play an important role with regard to disease progression in variety of human malignancies. Experimental and epidemiologic studies indicated that the genetic polymorphisms in the PTEN, PI3K genes are associated with cancer risk, yet little evidence exists for those 2 genes and colorectal cancer (CRC) risk. To address this, we evaluated whether PTEN rs701848, PIK3CA rs2699887 variants are associated with CRC susceptibility, clinicopathological parameters and clinical outcomes in CRC patients treated with FOLFOX (Oxaliplatin, Leucovorin, 5-Fluorouracil) regimen. A case-control study was performed in 780 CRC patients and 764 healthy controls using the TaqMan assay method. A significant increased risk of CRC was observed in patients carrying PTEN rs701848 TC or CC genotype (adjusted OR=1.306, 95% CI=1.030-1.655, P=0.027; adjusted OR=1.543, 95% CI=1.148-2.075, P=0.004, respectively), TC/CC genotype (adjusted OR=1.367, 95% CI=1.090-1.714, P=0.043) in the dominant model, and C allele (adjusted OR=1.229, 95% CI=1.067-1.416, P=0.004). However, no association was detected between rs2699887 in the PIK3CA gene and CRC risk. A significant association was found between pathological grade (Dukes A and B vs. Dukes C and D) and PIK3CA rs2699887 genotypes. Furthermore, Kaplan-Meier analysis revealed that PTEN rs701848 genotypes were significantly associated with the overall survival (OS) of CRC patients treated with FOLFOX regimen (n=780). Individuals carrying PTEN rs701848 TC or TC/CC genotypes showed significantly longer median survival time (MST) than TT genotype and significant hazard ratio (TC: adjusted HR=0.523, 95% CI=0.325-0.840, P=0.007; TC/CC: adjusted HR=0.545, 95% CI=0.351-0.845, P=0.007). Therefore, rs701848 polymorphism in the PTEN gene is associated with susceptibility to CRC, and C allele of rs701848 showed significant independent better prognosis of CRC patients treated with FOLFOX regimen. These results indicate that rs701848 in the PTEN gene might be a candidate pharmacogenomic factor to assess the susceptibility and prognosis in CRC patients.     

Role of GSTP1 Ile105Val and XRCC1 Arg194Trp,Arg280His and Arg399Gln gene polymorphisms in the clinical outcome of advanced non-small cell lung cancer

We conducted a study to investigate the association between the clinical outcome and GSTP1 Ile105Val and XRCC1 Arg194Trp, Arg280His and Arg399Gln gene polymorphisms in advanced NSCLC patients with cisplatin-based chemotherapy. Between January 2010 and December 2012, a total of 206 patients with advanced NSCLC were histopathologically confirmed were included into analysis. By logistic regression analysis, individuals carrying the AG and GG genotypes of GSTP1 Ile105Val were associated with better response to chemotherapy when compared with the AA genotype, and the adjusted Ors (95% CI) were 2.06 (1.10-3.86) and 4.89 (1.52-18.33), respectively. The TT genotype of XRCC1 Arg194Trp was correlated with better response to chemotherapy compared to the CC genotype, and the adjusted OR (95% CI) was 3.23 (1.20-9.30). By Cox Hazard Proportional Model, the GG genotype of GSTP1 Ile105Val and the TT genotype of XRCC1 Arg194Trp were found to be associated with lower risk of death from all causes when compared with the wide-type genotype, and the adjusted HRs (95% CI) were 0.05 (0.01-0.18) and 0.20 (0.07-0.62), respectively. Moreover, individuals carrying both the G/A+G/G genotype of GSTP1 Ile105Val and the G/A+A/A of XRCC1 Arg194Trp were associated with heavy greater CR+PR response to chemotherapy (OR=2.98, 95% CI=1.39-6.42), and also correlated with longer overall survival of advanced NSCLC (HR=0.19, 95% CI=0.05-0.61). In conclusion, we found that the GSTP1 Ile105Val and XRCC1 Arg194Trp were associated with better response to chemotherapy and longer survival of advanced NSCLC, compared to the wide-type genotype.     

Association of PTEN gene polymorphisms with liver cancer risk

Objective: To find out if there are any relationship between three single nucleotide polymorphisms (SNPs) of phosphatase and tensin homolog (PTEN) gene (rs1234213, rs1234220, and rs2299939) and the susceptibility of liver cancer. Methods: Genotypes of the three SNPs in the PTEN gene were achieved utilizing polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Comparison of genotypes and alleles distribution differences between the case and the control subjects was accomplished with χ² test. The analysis of linkage disequilibrium (LD) and haplotypes of the three SNPs was performed using SHEsis software. We adopted odds ratios (ORs) with 95% confidence intervals (95% CIs) to show the relative risk of liver cancer. Results: TC genotype and C allele of rs1234220 polymorphism showed much more frequently in cases than in controls, reflecting that the TC genotype and the C allele may be linked to the increased risk of liver cancer (OR=2.225, 95% CI=1.178-4.204; OR=1.941, 95% CI=1.124-3.351). Rs2299939 polymorphism showed an opposite result that the GT genotype probably reduce the risk of liver cancer (OR=0.483, 95% CI=0.259-0.900). Statistical significance was not found in the distribution differences of the genotypes of rs1234213 between two groups. LD and haplotype analysis results of the three SNPs showed that the T-C-G haplotype frequency was much higher in cases than in healthy objects, which proved that the T-C-G haplotype might be a susceptibility haplotype for liver cancer (OR=3.750, 95% CI=1.396-10.077). Conclusions: PTEN gene polymorphisms might relate to liver cancer risk.     

Glutathione S-transferase P1 Ile105Val Polymorphism and Oral Cancer Risk: A Meta-Analysis

Objective The glutathione S-transferase P1 (GSTP1) gene has been suggested to play an important role in the pathogenesis of oral cancer. However, the results have been inconsistent. In this study, we performed a meta-analysis to clarify the association of GSTP1 Ile105Val polymorphisms with oral cancer risk.Methods Published literature from PubMed and EMBASE were retrieved. Pooled odds ratio (OR) with 95% confidence interval (CI) was calculated using fixed- or random-effects model.Results 13 studies (1803 oral cancer cases and 2998 controls) for GSTP1 Ile105Val polymorphism were included in the meta-analysis. The results indicated that there was no significant association between GSTP1 Ile105Val polymorphism and oral cancer in the overall population (OR=1.30, 95%CI=0.92-1.38, I²=48.0%, p for heterogeneity=0.027). Further subgroup analysis by ethnicity suggested that GSTP1 Ile105Val polymorphism was significantly associated with oral cancer only in East Asians (OR=1.64, 95%CI=1.16-2.31, I²=0.0%, p for heterogeneity=0.525), but not in Caucasians (OR=1.16, 95%CI=0.73-1.82, I²=7.5%, p for heterogeneity=0.299), Africans (OR=1.10, 95%CI=0.37-3.28), South Asians (OR=1.20, 95%CI=0.69-2.08, I²=74.3%, p for heterogeneity=0.021) and mixed population (OR=0.91, 95%CI=0.70-1.20, I²=39.7%, p for heterogeneity=0.174).Conclusions The present meta-analysis has limited evidence to support the association of GSTP1 Ile105Val polymorphism with HCC risk in the overall population. However, GSTP1 Ile105Val polymorphism might be associated with risk of oral cancer in East Asians.     

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.     

Arg462Gln and Asp541Glu polymorphisms in ribonuclease L and prostate cancer risk: a meta-analysis

Objective

The association between ribonuclease L (RNASEL) gene polymorphisms and prostate cancer risk has been widely reported, but the results of these studies remained controversial and underpowered. We performed a meta-analysis of 28 studies to evaluate the association between Arg462Gln and Asp541Glu polymorphisms in the RNASEL gene and prostate cancer risk.

Methods

Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated to assess the association between RNASEL polymorphisms and prostate cancer risk.

Results

A significantly increased prostate cancer risk was found for the Arg462Gln polymorphism in Africans (Gln/Gln vs Arg/Arg: OR = 2.50, 95%CI = 1.28-4.87; Gln/Gln vs Gln/Arg + Arg/Arg: OR = 2.54, 95%CI = 1.30-4.95), but not in Europeans and Asians. Additionally, the Asp541Glu polymorphism was associated with increased total prostate cancer risk (Glu-allele vs Asp-allele: OR = 1.04, 95%CI = 1.01-1.07; Glu/Glu vs Asp/Asp: OR = 1.22, 95%CI = 1.03-1.46; Glu/Glu vs Glu/Asp + Asp/Asp: OR = 1.09, 95%CI = 1.02-1.16). In the stratified analysis for the Asp541Glu polymorphism, there was a significantly increased prostate cancer risk in Africans and Europeans, and in hospital-based prostate cancer cases.

Conclusion

The meta-analysis results showed evidence that RNASEL Arg462Gln and Asp541Glu polymorphisms are associated with prostate cancer risk and could be low-penetrance prostate cancer susceptibility biomarkers.     

Impact of Toll-like receptor 4 polymorphisms on risk of cancer

Toll-like receptor 4 (TLR4) is one of the key immune system effectors playing the main role in recognition of viruses and bacteria. Dysregulation of the TLR4 signaling owing to single nucleotide polymorphisms (SNPs) may alter the ligand binding and balance between pro- and anti-inflammatory cytokines, thereby modulating the risk of chronic inflammation and cancer. TLR4 polymorphisms may be associated with at least nine types of cancer. The most intensively investigating TLR4 polymorphisms are Asp299Gly (rs4986790) and Thr399Ile (rs4986791). It seems to be that Asp299Gly and Thr399Ile are related to increased risk of precancerous gastric lesions, and, possibly, gastric cancer. Thr399Ile also may be connected with gallbladder cancer, and both of these polymorphisms apparently have no impact on risk of prostate cancer. However, the data about many SNPs and their associations with different types of cancer are conflicting, and further large, well-designed, comprehensive studies in various populations are necessary for solution of this problem. The short list of TLR4 SNPs for further investigation may include TLR4_896A/G (Asp299Gly, rs4986790), TLR4_1196C/T (Thr399Ile, rs4986791), Thr135Ala, TLR4_1859 G/A (rs11536858), TLR4_2032T/C (rs10116253), TLR4_2437A/G (rs1927914), TLR4_2856T/C (rs10759932), TLR4_3725 G/C (rs11536889), TLR4_7764 G/A (rs1927911), TLR4_11350G/C, TLR4_11912 G/T (rs2149356), TLR4_16649G/C (rs7873784), and TLR4_17050T/C (rs11536891).     

Toll-like 4 receptor variant, Asp299Gly, and reduced risk of hemorrhagic cystitis after hematopoietic stem cell transplantation

Hemorrhagic cystitis (HC) is a major cause of morbidity after hematopoietic stem cell transplantation. Toll-like receptor 4 (TLR4) is a pattern recognition receptor of the innate immune system and induces inflammation. Individuals with the single nucleotide polymorphisms Thr399Ile (rs4986791) or Asp299Gly (rs4986790) of TLR4 show diminished inflammatory responsiveness to endotoxins. The genotype of TLR4 was determined in 166 children who underwent allogeneic hematopoietic stem cell transplantation and in their donors. Asp299Gly was present in 21 patients (13%) and 24 donors (14%). Thr399Ile was found in 22 patients (13%) and 25 donors (15%). The incidence of HC was significantly lower in patients with Asp299Gly (0% vs 23%; P = .009) and in patients who underwent transplantation from a donor with Asp299Gly (4% vs 23%; P = .05). The trend was the same for Thr399Ile-donor positive (8% vs 22%; P = .17), recipient positive (9% vs 22%; P = .25), donor or recipient positive (8% vs 23%; P = .04). Multivariate analysis revealed age, conditioning with busulfan, and absence of Asp299Gly as independent risk factors for HC. In conclusion, the TLR4 Asp299Gly variant seems to confer protection against hemorrhagic cystitis. This study provides the first indication that the innate immune system through TLR4 signaling pathway plays a role in the pathogenesis of HC after hematopoietic stem cell transplantation.     

Genetic regulation of ionizing radiation sensitivity and breast cancer risk

Genetic variability in DNA repair may contribute to hypersensitivity to ionizing radiation (IR) and susceptibility to breast cancer. We used samples collected from a clinic-based breast cancer case-control study to test the working hypothesis that amino acid substitution variants of DNA repair genes may contribute to prolonged cell-cycle delay following IR and breast cancer risk. Fluorescence-activated cell sorter (FACS) analysis was used to measure cell-cycle delay. PCR-restriction fragment length polymorphism (RFLP) assays were used to determine four genotypes of three DNA repair genes: XRCC1, 194 Arg/Trp and 399 Arg/Gln; XRCC3, 241 Thr/Met; and APE1, 148 Asp/Glu. The data showed that breast cancer patients had a significantly higher delay index than that of controls (P < 0.001); the means +/- SD for cases and controls were 36.0 +/- 13.1 (n = 118) and 31.4 +/- 11.5 (n = 225), respectively. There was a significant dose-response relationship between delay index, categorized into quartiles, and an increasing risk of breast cancer (crude odds ratios: 1.00, 1.00, 1.27, and 2.46, respectively; P(trend) = 0.002). In controls, prolonged cell-cycle delay was significantly associated with the number of variant alleles in APE1 Asp148Glu and XRCC1 Arg399Gln genotypes (P(trend) = 0.001). Although larger studies are needed to validate the results, our data suggest that an inherited hypersensitivity to IR may contribute to human breast carcinogenesis.     

Glyoxalase I Ala111Glu gene polymorphism: No association with breast cancer risk but correlated with absence of progesterone receptor

The aim of the present study was to evaluate the association between the Glyoxalase I (GLOI) Ala111Glu polymorphism and breast cancer risk among the major Malaysian ethnic groups, the Malays, Chinese and Indians, as well as clinico‐pathological characteristics of these patients. Genotyping of GLOI gene was performed on blood samples obtained from 387 patients and 252 normal healthy women who had no history of any malignancy using the polymerase chain reaction‐restriction fragment length polymorphism (PCR‐RFLP) method. The genotype and allele frequencies of GLOI polymorphism were not significantly different between the patients and normal individuals among the Malays (P= 0.721, 0.402), Chinese (P= 0.208, 0.079) and Indians (P= 0.612, 0.349), respectively. The Malay, Chinese and Indian women who were Glu/Glu homozygotes (P= 0.419, 0.093, 0.367), Ala/Glu heterozygotes (P= 0.648, 0.182, 0.402) and carriers of Glu allele (P= 0.402, 0.079, 0.349), respectively, were not associated with breast cancer risk. The Glu allele genotype was significantly associated with absence of progesterone receptor (P= 0.036). Thus, the polymorphic variant of the GLOI gene might not be a useful genetic marker to identify Malaysian Malay, Chinese or Indian women who could be at greater risk of developing breast cancer.     

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.     

The FAS ligand promoter polymorphism,rs763110 (?844C>T), contributes to cancer susceptibility: evidence from 19 case–control studies

The potentially functional polymorphism, rs763110 (−844C>T), in the promoter region of the FAS ligand (FASL) gene, has been implicated in cancer risk, but individually published studies show inconclusive results. To derive a more precise estimation of the association between the FASL rs763110 and risk of cancer, we performed a meta-analysis of 19 published studies that included 11 105 cancer cases and 11 372 controls. We used odds ratios (ORs) and 95% confidence intervals (CIs) to assess the strength of the associations. Overall, the rs763110 CT and TT variant genotypes were associated with a significantly reduced cancer risk of all cancer types in different genetic models (homozygote comparison: OR=0.80, 95% CI: 0.68–0.95, P_{heterogeneity}=0.001; heterozygote comparison: OR=0.82, 95% CI: 0.72–0.95, P_{heterogeneity}<0.001; dominant model comparison: OR=0.82, 95% CI: 0.71–0.94, P_{heterogeneity}<0.001; and recessive model comparison: OR=0.88, 95% CI: 0.81–0.96, P_{heterogeneity}=0.074). In the stratified analyses, the risk remained for studies of the smoking-related cancers and Asian populations, or population-based studies in all the genetic models. Although some modest bias could not be eliminated, this meta-analysis suggests that the FASL rs763110 T allele has a possible protective effect on cancer risk.