Although in recent years deleterious BRCA1 mutations have been extensively studied as a prostate cancer risk factor, results are inconclusive. To assess the contribution of the BRCA1 Galician founder mutation c.211A>G in prostate cancer morbidity we conducted a case-control study. Moreover, to better elucidate whether deleterious BRCA1 mutations are involved in the development of prostate cancer, we performed a systematic review and a meta-analysis of BRCA1 studies on prostate cancer.

We present previously unknown evidence that the immunoglobulin heavy chain binding protein BIP/HSPA5, also known as glucose regulated protein (GRP)78, serving as a pivotal component of the pro-survival axis of the unfolded protein response (UPR) signalling network, is abundantly expressed in relapsed B-lineage acute lymphoblastic leukaemia (ALL) and contributes to chemotherapy resistance of leukaemic B-cell precursors. The resistance of B-lineage ALL cells to the standard anti-leukaemic drug vincristine was overcome by the HSPA5 inhibitor epigallocatechin gallate, which inhibits the anti-apoptotic function of HSPA5 by targeting its ATP-binding domain. Notably, chemotherapy-resistant B-lineage ALL cells underwent apoptosis within 48 h of exposure to a doxorubicin-conjugated cell-penetrating cyclic anti-HSPA5 peptide targeting surface-expressed HSPA5 molecules on leukaemia cells. The identification of the HSPA5 as a chemoresistance biomarker and molecular target for B-lineage ALL may lead to new anti-leukaemic treatment strategies that are much needed.

To evaluate the effect of the methylenetetrahydrofolate reductase C677T genetic polymorphism (MTHFR C677T) and folate intake on the risk of esophageal cancer.

Studies of the association between the cyclin D1 (CCND1) G870A genetic polymorphism and risk of colorectal cancer (CRC) have generated conflicting results. In order to derive a more precise estimation, a meta-analysis was here performed.

More than 1000 reports have been published in the past two decades on associations between variants in candidate genes and risk of breast cancer. Results have been generally inconsistent. We did a literature search and meta-analyses to provide a synopsis of the current understanding of the genetic architecture of breast-cancer risk.

p73 G4C14-A4T14 polymorphism has been hypothesised to be associated with the risk of cancer development by many epidemiological studies, however, the available results were conflicting. To derive a more precise estimation of association between the p73 G4C14-A4T14 polymorphism and risk of cancer, we performed a meta-analysis based on 8017 cancer cases and 11610 controls from 25 publications with 27 individual case-control studies. The odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of the association. Overall, We found that the variant AT/AT homozygote was associated with a significantly increased risk of all types of cancer (homozygote comparison: OR = 1.35, 95% CI = 1.11-1.65; recessive model comparison: OR = 1.32, 95% CI = 1.11-1.58). In the subgroup analyses by ethnicity/country, the results suggested that AT/AT genotype was significantly associated with risk of cancer development among Caucasians and Asians, especially for the Americans and Japanese. Moreover, when stratifying by types of cancer, significantly increased cancer risks were observed for colorectal cancer, 'head and neck cancers' and 'other cancers'. Interestingly, when stratifying by source of controls, a significantly elevated risk was found among hospital-based studies but not among population-based studies. Limiting the analysis to the studies within Hardy-Weinberg equilibrium, the results were persistent and robust. No publication bias was found in the present study. This meta-analysis suggests that the p73 -AT allele may be a low-penetrant risk factor for cancer development.

The Arg194Trp polymorphism in the X-ray repair cross-complementing group 1 (XRCC1) gene has been proved to be in association with cancer risk in Chinese Mainland population, but a large number of studies have reported inconclusive results. A more comprehensive and precise estimation of the relationship is needed to clear the way towards future studies. Thus, we performed a meta-analysis to analysis these associations. A total of 34 case-control studies in 34 articles were included in this meta-analysis. The results showed that the 194Trp/Trp homozygote had a 31% increased risk of cancer than 194Trp/Arg and 194Arg/Arg genotypes, OR was 1.31 and 95%CI was 1.13 to 1.53. In the subgroup analysis by cancer sites, the Arg194Trp polymorphism was associated with increased risks of lung cancer (OR = 1.27 and 95%CI: 1.07-1.50 for Trp/Trp versus Arg/Arg + Arg/Trp) and esophageal cancer (OR = 1.68 and 95%CI: 1.33-2.13 for Trp/Trp versus Arg/Arg + Arg/Trp). This meta-analysis suggested that the Arg194Trp polymorphism of the XRCC1 gene is a cancer susceptible factor among Chinese Mainland population. More intensive and deeper studies are needed to further reveal the mechanism between Arg194Trp polymorphisms of XRCC1 gene and cancer risks in Chinese Mainland population.

Methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms have been implicated in childhood acute lymphoblastic leukemia (ALL) risk, but previously published studies were inconsistent and recent meta-analyses were not adequate.

MicroRNAs (miRNAs) are a family of endogenous, small and noncoding RNAs that negatively regulate gene expression by suppressing translation or degrading mRNAs. Recently, many studies investigated the association between hsa-miR-196a2 rs11614913 polymorphism and cancer risk, which showed inconclusive results.

Defective microRNA (miRNA) biogenesis contributes to the development and progression of epithelial ovarian cancer (EOC). In this study, we examined the hypothesis that single nucleotide polymorphisms (SNP) in miRNA biogenesis genes may influence EOC risk. In an initial investigation, 318 SNPs in 18 genes were evaluated among 1,815 EOC cases and 1,900 controls, followed up by a replicative joint meta-analysis of data from an additional 2,172 cases and 3,052 controls. Of 23 SNPs from 9 genes associated with risk (empirical P < 0.05) in the initial investigation, the meta-analysis replicated 6 SNPs from the DROSHA, FMR1, LIN28, and LIN28B genes, including rs12194974 (G>A), an SNP in a putative transcription factor binding site in the LIN28B promoter region (summary OR = 0.90, 95% CI: 0.82-0.98; P = 0.015) which has been recently implicated in age of menarche and other phenotypes. Consistent with reports that LIN28B overexpression in EOC contributes to tumorigenesis by repressing tumor suppressor let-7 expression, we provide data from luciferase reporter assays and quantitative RT-PCR to suggest that the inverse association among rs12194974 A allele carriers may be because of reduced LIN28B expression. Our findings suggest that variants in LIN28B and possibly other miRNA biogenesis genes may influence EOC susceptibility.

Tumor necrosis factor-α (TNF-α) is an important pro-inflammatory cytokine in the development and progress in human cancer. TNF-α polymorphisms have been confirmed to influence the risk for several types of cancer, however, the associations between TNF-α polymorphisms and breast cancer (BC) remain controversial and ambiguous. The aim of this meta-analysis is to explore more precise estimations regarding this point. Electronic searches of several databases were conducted for all online publications on the associations between TNF-α-238, -308, -857, -863, -1031, -1210 polymorphisms and BC through March 2011. Odds ratios (OR) with 95% confidence intervals (95% CI) were calculated to assess the strength of these associations in fixed- and random-effect models with Review manager 5.0. A total of 17 studies with 44,442 BC patients and 49,926 controls involved were identified. This meta-analysis showed no significant association between TNF-α-308 polymorphism and BC (AA + GA vs. GG: OR = 0.95, 95% CI = 0.82-1.09) in overall and (OR = 1.44, 95% CI = 0.61-3.40) Asian populations, however, a negative association was shown in Caucasian subgroup (OR = 0.91, 95% CI = 0.85-0.97). As regards the TNF-α-238 polymorphism, the OR values (95% CI) were 0.99 (0.94-1.05), 0.94 (0.78-1.14), and 1.00 (0.95-1.05) for the overall, Asian, and Caucasian studies, respectively. No significant associations were found for other polymorphisms. Furthermore, there was a coincidence in the sensitivity analysis of these associations. No publication bias was detected in this study. To sum up, no significant associations were found between the TNF-α-308, -238, -857, -863, -1031, -1210 polymorphisms and the risk for BC in overall populations, whereas a negative association was found between TNF-α-308 polymorphism and BC in Caucasian populations.

Multiple epidemiological studies have investigated rs1136201, a non-synonymous polymorphism of the human epidermal growth factor receptor-2 gene (HER2) resulting in the substitution of valine for isoleucine at codon 655 (Ile655Val) of the HER2 protein, as a risk factor for breast cancer.

Glutathione S-transferase M1 (GSTM1), which plays an important role in detoxification pathways to protect against damage caused by reactive metabolites of chemicals, has been considered as potential gastric cancer susceptibility genes. However, the published data on the association between GSTM1 present/null polymorphism and gastric cancer risk are still inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. Totally, 44 studies including 5440 cases and 11607 controls were involved in the analysis. When all studies were pooled into the meta-analysis, obviously increased gastric cancer risk was found in null genotype carriers (OR=1.19, 95% CI: 1.08-1.33). When stratified by ethnicity, obviously evaluated risk was found in Asians (OR=1.31, 95% CI: 1.11-1.54) but not reached to statistically significance in Caucasians (OR=1.11, 95% CI: 0.96-1.28). In the subgroup analysis by hospital-based studies or population-based studies, statistically significantly elevated risk was found in hospital-based studies (OR=1.34, 95% CI: 1.07-1.67) but not reached to statistically significance in population-based studies (OR=1.11, 95% CI: 0.99-1.25). In summary, this meta-analysis result indicates that the GSTM1 null genotype is a low-penetrant risk factor for gastric cancer development in Asians.

Several DNA microarray based expression signatures for the different clinically relevant thyroid tumor entities have been described over the past few years. However, reproducibility of these signatures is generally low, mainly due to study biases, small sample sizes and the highly multivariate nature of microarrays. While there are new technologies available for a more accurate high throughput expression analysis, we show that there is still a lot of information to be gained from data deposited in public microarray databases. In this study we were aiming (1) to identify potential markers for papillary thyroid carcinomas through meta analysis of public microarray data and (2) to confirm these markers in an independent dataset using an independent technology.

IL-8-251A>T polymorphisms have been reported to influence the risk for breast cancer in many studies; however, the results still remain controversial and ambiguous. The aim of this study was to determine more precise estimations for the relationship between IL-8-251A>T polymorphisms and the risk for breast cancer.

Telomeres shorten with each cell division and are essential for chromosomal stability. Short telomeres in surrogate tissues (e.g., blood cells) are associated with increased cancer risk in several case-control studies, but findings are inconsistent in prospective studies.

Previous studies have found that common genetic variants on chromosome 8q24 are associated with the risk of developing colorectal neoplasia. We conducted a hospital-based case-control study, including 435 cases and 788 unrelated controls to investigate the associations between common variants on 8q24 and the risk of colorectal cancer in a Chinese population. We also evaluated the association of rs6983267 with colorectal neoplasia in the published literature via a meta-analysis study. We found that rs6983267 was significantly associated with the risk of colorectal cancer in the Chinese population, with an adjusted odds-ratio (OR) for the GT heterozygotes and GG homozygotes of 1.30 (95% CI= 0.98-1.71, P = 0.069) and 1.66 (95% CI = 1.18-2.34, P = 0.004), respectively, compared to the TT homozygotes, with a P-trend value of 0.003. No association was found for the other three loci (rs16901979, rs1447295 and rs7837688). In the meta-analysis of the published genetic association studies, the rs6983267 variant was found to be associated with an increased risk of colorectal neoplasia. The heterozygous GT carriers showed a 20% increased risk of colorectal neoplasia (OR= 1.20, 95% CI= 1.16-1.25; random effects model) with a summary OR for homozygous GG carriers of 1.39 (95% CI= 1.32-1.48; random effects model) compared to the TT genotype carriers. We found no significant differences between the association of rs6983267 and colorectal cancer and colorectal adenomas. In summary, our study confirms that the variant rs6983267 is a risk factor for colorectal neoplasia in various populations, including the Chinese population.

To investigate the association between TP53 Arg72Pro polymorphism and esophageal cancer (EC) risk using meta-analysis.

To evaluate the association between p53 codon 72 polymorphism and liver cancer risk by means of meta-analysis.

To address the association between variants and breast cancer, an increasing number of articles on genetic association studies, genome-wide association studies (GWASs), and related meta- and pooled analyses have been published. Such studies have prompted an updated assessment of the associations between gene variants and breast cancer risk. We searched PubMed, Medline, and Web of Science and retrieved a total of 87 meta- and pooled analyses, which addressed the associations between 145 gene variants and breast cancer. Analyses met the following criteria: (1) breast cancer was the outcome, (2) the articles were all published in English, and (3) in the recent published meta- and pooled analyses, the analyses with more subjects were selected. Among the 145 variants, 46 were significantly associated with breast cancer and the other 99 (in 62 genes) were not significantly associated with breast cancer. The summary ORs for the 46 significant associations (P < 0.05) were further assessed by the method of false-positive report probability (FPRP). Our results demonstrated that 10 associations were noteworthy: CASP8 (D302H), CHEK2 (*1100delC), CTLA4 (+49G>A), FGFR2 (rs2981582, rs1219648, and rs2420946), HRAS (rare alleles), IL1B (rs1143627), LSP1 (rs3817198), and MAP3K1 (rs889312). In addition, eight GWASs were identified, in which 25 loci were obtained (14 in nine genes, six near a gene or genes, and five intergenic loci). Of the 25 SNPs, 20 were noteworthy: C6orf97 (rs2046210 and rs3757318), FGFR2 (rs2981579, rs1219648, and rs2981582), LSP1 (rs909116), RNF146 (rs2180341), SLC4A7 (rs4973768), MRPS30 (rs7716600), TOX3 (rs3803662 and rs4784227), ZNF365 (rs10995190), rs889312, rs614367, rs13281615, rs13387042, rs11249433, rs1011970, rs614367, and rs1562430. In summary, in this review of genetic association studies, 31.7% of the gene-variant breast cancer associations were significant, and 21.7% of these significant associations were noteworthy. However, in GWASs, 80% of the significant associations were noteworthy.