Background. Macrosomia has become a worldwide problem with the rapid economic growth in the past few years. However, the detailed mechanism of how the macrosomia happened remains unknown. Growing evidence indicates that miRNAs are involved in maintaining metabolic homeostasis. We hypothesized that serum miRNAs are potential biomarkers for macrosomia. Methods. We performed miRNAs profiling using TLDA chips in the discovery phase in two pooled samples from 30 cases and 30 controls, respectively. Individual qRT-PCR was conducted for the discovery phase samples. To confirm the results, we detected the miRNAs which were differentially expressed in the microarray assays and individual qRT-PCR in external validation phase with another 30 cases and 30 controls. Results. In the discovery stage, miR-194 and miR-376a expression levels were significantly different between macrosomia group and controls (P = 0.048 for miR-194 and P = 0.018 for miR-376a, resp.). Further evaluation of the two miRNAs on a total of 120 serum samples showed that the miR-376a remains significantly lower in macrosomia (P = 0.032). Receiver operating characteristic curve analyses showed that the area under curve for miR-376a was 67.8% (sensitivity = 96.7% and specificity = 40.0%). Conclusions. Serum miR-376a may serve as a potential noninvasive biomarker in detecting macrosomia.
Congenital heart disease (CHD) is the most common form of congenital human birth anomalies and a leading cause of perinatal and infant mortality. Some studies including our published genome-wide association study (GWAS) of CHD have indicated that genetic variants may contribute to the risk of CHD. Recently, Cordell et al. published a GWAS of multiple CHD phenotypes in European Caucasians and identified 3 susceptibility loci (rs870142, rs16835979 and rs6824295) for ostium secundum atrial septal defect (ASD) at chromosome 4p16. However, whether these loci at 4p16 confer the predisposition to CHD in Chinese population is unclear. In the current study, we first analyzed the associations between these 3 single nucleotide polymorphisms (SNPs) at 4p16 and CHD risk by using our existing genome-wide scan data and found all of the 3 SNPs showed significant associations with ASD in the same direction as that observed in Cordell’s study, but not with other subtypes- ventricular septal defect (VSD) and ASD combined VSD. As these 3 SNPs were in high linkage disequilibrium (LD) in Chinese population, we selected one SNP with the lowest P value in our GWAS scan (rs16835979) to perform a replication study with additional 1,709 CHD cases with multiple phenotypes and 1,962 controls. The significant association was also observed only within the ASD subgroup, which was heterogeneous from other disease groups. In combined GWAS and replication samples, the minor allele of rs16835979 remained significant association with the risk of ASD (OR = 1.22, 95% CI = 1.08–1.38, P = 0.001). Our findings suggest that susceptibility loci of ASD identified from Cordell’s European GWAS are generalizable to Chinese population, and such investigation may provide new insights into the roles of genetic variants in the etiology of different CHD phenotypes.
Single-nucleotide polymorphisms (SNPs) at 6q25.1 that are associated with breast cancer susceptibility have been identified in several genome-wide association studies (GWASs). However, the exact causal variants in this region have not been clarified.
In the present study, we genotyped six potentially functional single-nucleotide polymorphisms (SNPs) within the CCDC170 and ESR1 gene regions at 6q25.1 and accessed their associations with risk of breast cancer in a study of 1,064 cases and 1,073 cancer-free controls in Chinese women. The biological function of the risk variant was further evaluated by performing laboratory experiments.
Breast cancer risk was significantly associated with three SNPs located at 6q25.1—rs9383935 in CCDC170 and rs2228480 and rs3798758 in ESR1—with variant allele attributed odds ratios (ORs) of 1.38 (95% confidence interval (CI): 1.20 to 1.57, P = 2.21 × 10−6), 0.84 (95% CI: 0.72 to 0.98, P = 0.025) and 1.19 (95% CI: 1.04 to 1.37, P = 0.013), respectively. The functional variant rs9383935 is in high linkage disequilibrium (LD) with GWAS-reported top-hit SNP (rs2046210), but only rs9383935 showed a strong independent effect in conditional regression analysis. The rs9383935 risk allele A showed decreased activity of reporter gene in both the MCF-7 and BT-474 breast cancer cell lines, which might be due to an altered binding capacity of miR-27a to the 3′ untranslated region (3′ UTR) sequence of CCDC170. Real-time quantitative reverse transcription PCR confirmed the correlation between rs9383935 genotypes and CCDC170 expression levels.
The results of this study suggest that the functional variant rs9383935, located at the 3′ UTR of CCDC170, may be one candidate of the causal variants at 6q25.1 that modulate the risk of breast cancer.
Electronic supplementary material
The online version of this article (doi:10.1186/s13058-014-0422-x) contains supplementary material, which is available to authorized users.
Hand, foot and mouth disease, associated with enterovirus 71 (EV71) infections, has recently become an important public health issue throughout the world. Serum neutralizing antibodies are major indicators of EV71 infection and protective immunity. However, the potential for cross-reactivity of neutralizing antibodies for different EV71 genotypes and subgenotypes is unclear. Here we measured the cross-reactive neutralizing antibody titers against EV71 of different genotypes or subgenotypes in sera collected from EV71-infected children and vaccine-inoculated children in a phase III clinical trial (ClinicalTrials.gov Identifier: NCT01636245) using a new pseudovirus-based neutralization assay. Antibodies induced by EV71-C4a were cross-reactive for different EV71 genotypes, demonstrating that C4a is a good candidate strain for an EV71 vaccine. Our study also demonstrated that this new assay is practical for analyses of clinical samples from epidemiological and vaccine studies.
Certain pseudogenes may regulate their protein-coding cousins by competing for miRNAs and play an active biological role in cancer. However, few studies have focused on the association of genetic variations in pseudogenes with cancer prognosis. We selected six potentially functional single nucleotide polymorphisms (SNPs) in cancer-related pseudogenes, and performed a case-only study to assess the association between those SNPs and the prognosis of hepatocellular carcinoma (HCC) in 331 HBV-positive HCC patients without surgical treatment. Log-rank test and Cox proportional hazard models were used for survival analysis. We found that the A allele of rs9909601 in E2F3P1 was significantly associated with a better prognosis compared with the G allele [adjusted hazard ratio (HR) = 0.69, 95% confidence interval (CI) = 0.56–0.86, P = 0.001]. Additionally, this protective effect was more predominant for patients without chemotherapy and transcatheter hepatic arterial chemoembolization (TACE) treatment. Interestingly, we also detected a statistically significant multiplicative interaction between genotypes of rs9909601 and chemotherapy or TACE status on HCC survival (P for multiplicative interaction < 0.001). These findings indicate that rs9909601 in the pseudogene E2F3P1 may be a genetic marker for HCC prognosis in Chinese.
pseudogene; E2F3P1; SNP; hepatocellular carcinoma (HCC); prognosis
MiR-378 has been reported to be related to cell survival, tumor growth and angiogenesis and may participate in hepatocellular carcinoma (HCC) development and prognosis. Genetic variants in primary miR-378 (pri-miR-378) may impact miR-378 expression and contribute to HCC risk and survival. This study aimed to assess the associations between a genetic variant in primary miR-378 and HCC susceptibility and prognosis.
We conducted a case-control study to analyze the association of rs1076064 in pri-miR-378 with hepatocellular carcinoma risk in 1300 HCC patients with positive hepatitis B virus (HBV) and 1344 HBV carriers. Then, we evaluated the correlation between the polymorphism and hepatocellular carcinoma prognosis in 331 HCC patients at either intermediate or advanced stage without surgical treatment.
The variant genotypes of rs1076064 were associated with a decreased HCC risk in HBV carriers [Adjusted odds ratio (OR) = 0.90, 95% confidence intervals (CI) = 0.81–1.00, P = 0.047]. Moreover, HCC patients with the variant genotypes were associated with a better survival [Adjusted hazard ratio (HR) = 0.70, 95% CIs = 0.59–0.83, P<0.0001 in an additive genetic model]. The reporter gene assay showed that the variant G allele of rs1076064 exerted higher promoter activity than the A allele.
These findings indicate that rs1076064 may be a biomarker for HCC susceptibility and prognosis through altering pri-miR-378 transcription.
The Fever, Thrombocytopenia and Leukopenia Syndrome (FTLS) is caused by a bunyavirus known as the FTLS virus (FTLSV), which was recently discovered in China. We examined the epidemiological and etiological features of 637 laboratory-confirmed cases of FTLS with onset from January 2011 to December 2012 in Henan Province, China. The highest incidence of FTLS occurred between May and August: 76.5% of all laboratory-confirmed cases occurred during those four months. Of the laboratory-confirmed cases, 60.9% were in the 46–69 years old age groups; 96.1% (612/637) occurred in farmers; 98.1% (625/637) were reported from Xinyang Prefecture. During the same time period, 2047 cases were reported in China. The nucleotide and amino acid sequences of FTLSV strains identified during 2011–2012 in Henan Province were ≥96% identical. This findings provides insight for developing public-health interventions for the control and prevention of FTLS in epidemic area.
Genetic variants in human microRNA (miRNA) genes may alter mature miRNA processing and/or target selection, and likely contribute to cancer susceptibility and disease progression. Previous studies have suggested that miR-101 may play important roles in the development of cancer by regulating key tumor-associated genes. However, the role of single nucleotide polymorphisms (SNPs) of miR-101 in breast cancer susceptibility remains unclear. In this study, we genotyped 11 SNPs of the miR-101 genes (including miR-101-1 and miR-101-2) in a case-control study of 1064 breast cancer cases and 1073 cancer-free controls. The results revealed that rs462480 and rs1053872 in the flank regions of pre-miR-101-2 were significantly associated with increased risk of breast cancer (rs462480 AC/CC vs AA: adjusted OR = 1.182, 95% CI: 1.030–1.357, P = 0.017; rs1053872 CG/GG vs CC: adjusted OR = 1.179, 95% CI: 1.040–1.337, P = 0.010). However, the remaining 9 SNPs were not significantly associated with risk of breast cancer. Additionally, combined analysis of the two high-risk SNPs revealed that subjects carrying the variant genotypes of rs462480 and rs1053872 had increased risk of breast cancer in a dose-response manner (Ptrend = 0.002). Compared with individuals with “0–1” risk allele, those carrying “2–4” risk alleles had 1.29-fold risk of breast cancer. In conclusion, these findings suggested that the SNPs rs462480 and rs1053872 residing in miR-101-2 gene may have a solid impact on genetic susceptibility to breast cancer, which may improve our understanding of the potential contribution of miRNA SNPs to cancer pathogenesis.
MiR-106b-25 cluster, hosted in intron 13 of MCM7, may play integral roles in diverse processes including immune response, tumorigenesis and progression. A single nucleotide polymorphism (SNP), rs999885, is located in the promoter region of MCM7. Our previous study showed that the A to G base change of rs999885 may provide an increased risk for HCC in HBV persistent carriers by altering the expression of the miR-106b-25 cluster. However, it is unknown whether rs999885 is associated with prognosis of intermediate or advanced HBV-related hepatocellular carcinoma (HCC) patients.
The SNP, rs999885, was genotyped by using the TaqMan allelic discrimination Assay in 414 intermediate or advanced HCC patients. Log-rank test and Cox proportional hazard models were used for survival analysis.
The variant genotypes of rs999885 were associated with a significantly decreased risk of death for intermediate or advanced HCC [additive model: adjusted hazard ratio (HR) = 0.76,95% confidence intervals (CI) = 0.59–0.97]. Further stepwise regression analysis suggested that rs999885 was an independently protective factor for the prognosis of HCC in the final model (additive model: adjusted HR = 0.72, 95% CI = 0.56–0.91, P = 0.007).
These findings indicate that the A to G base change of rs999885 may provide a protective effect on the prognosis of intermediate or advanced HCC in Chinese.
The activation of Toll-like receptors (TLRs) may be an important event in the immune evasion of tumor cell. Recently, numerous studies have investigated the associations between TLR2 −196 to −174 del and two SNPs of TLR4 (rs4986790 and rs4986791) and the susceptibility to different types of cancer; however, the results remain conflicting. The aim of this study was to assess the association between TLR2 and TLR4 polymorphisms and cancer risk in a meta-analysis with eligible published studies.
A dataset composed of 14627 cases and 17438 controls from 34 publications were included in a meta-analysis to evaluate the association between overall cancer risk or cancer-specific risk and three SNPs of TLRs (TLR2 −196 to −174 del, TLR4 rs4986790 and rs4986791). The results showed that all of these three polymorphisms were significantly associated with the increased cancer risk (dominant model: OR = 1.64, 95% CI: 1.04–2.60 for TLR2 −196 to −174 del; OR = 1.19, 95% CI: 1.01–1.41 for TLR4 rs4986790; and OR = 1.47, 95% CI: 1.120–1.80 for TLR4 rs4986791; respectively). In stratified analysis, we found the effect of TLR2 −196 to −174 del on cancer risk remained significant in the subgroup of Caucasians and South Asians, but not in East Asians. However, the association between rs4986791 and cancer risk was significant in both South Asians and East Asians, but not in Caucasians. Furthermore, the association between rs4986790 and cancer risk was statistically significant in digestive cancers (dominant model: OR = 1.76, 95% CI: 1.13–2.73) and female-specific cancers (dominant model: OR = 1.50, 95% CI: 1.16–1.94). However, no significant association with risk of digestive system cancers was observed for TLR2 −196 to −174 del and TLR4 rs4986791.
This meta-analysis presented additional evidence for the association between TLR2 and TLR4 polymorphisms and cancer risk. Further well-designed investigations with large sample sizes are required to confirm this conclusion.
Genetic variation may influence chemotherapy response and overall survival in cancer patients.
We conducted a genome-wide scan in 535 advanced-stage non–small cell lung cancer (NSCLC) patients from two independent cohorts (307 from Nanjing and 228 from Beijing). A replication was carried out on an independent cohort of 340 patients from Southeastern China followed by a second validation on 409 patients from the Massachusetts General Hospital (Boston, MA).
Consistent associations with NSCLC survival were identified for five single-nucleotide polymorphisms (SNP) in Chinese populations with P values ranging from 3.63 × 10−5 to 4.19 × 10−7 in the additive genetic model. The minor allele of three SNPs (rs7629386 at 3p22.1, rs969088 at 5p14.1, and rs3850370 at 14q24.3) were associated with worse NSCLC survival while 2 (rs41997 at 7q31.31 and rs12000445 at 9p21.3) were associated with better NSCLC survival. In addition, rs7629386 at 3p22.1 (CTNNB1) and rs3850370 at 14q24.3 (SNW1-ALKBH1-NRXN3) were further replicated in the Caucasian population.
In this three-stage genome-wide association studies, we identified five SNPs as markers for survival of advanced-stage NSCLC patients treated with first-line platinum-based chemotherapy in Chinese Han populations. Two of these SNPs, rs7629386 and rs3850370, could also be markers for survival among Caucasian patients.
A recent genome-wide association study (GWAS) has identified three new breast cancer susceptibility loci at 12p11, 12q24 and 21q21 in populations of European descent. However, because of the genetic heterogeneity, it is largely unknown for the role of these loci in the breast cancer susceptibility in the populations of non-European descent.
Here, we genotyped three variants (rs10771399 at 12p11, rs1292011 at 12q24 and rs2823093 at 21q21) in an independent case–control study with a total of 1792 breast cancer cases and 1867 cancer-free controls in a Chinese population. We found that rs10771399 and rs1292011 were significantly associated with risk of breast cancer with per-allele odds ratios (ORs) of 0.85 (95% confidence interval (CI): 0.76–0.96; P = 0.010) and 0.84 (95% CI: 0.76–0.95; P = 4.50×10−3), respectively, which was consistent with those reported in populations of European descent. Similar effects were observed between ER/PR positive and negative breast cancer for both loci. However, we did not found significant association between rs2823093 and breast cancer risk (OR = 0.97, 95%CI = 0.76–1.24; P = 0.795).
Our results indicate that genetic variants at 12p11 and 12q24 may also play an important role in breast cancer development in Chinese women.
A single nucleotide polymorphism (SNP) rs999737 at 14q24.1 was identified as a susceptibility marker of breast cancer in a genome-wide association study of the European population, which was also confirmed by some of the following studies in populations of European descent. However, rs999737 is very rare or nonpolymorphic in non-Europeans including Chinese, and the role of other genetic variants at 14q24.1 has not been evaluated in populations of non-European descent. In this study, we first selected 21 common tagging SNPs (minor allele frequency [MAF] >0.05 in the Chinese population) by searching the Hapmap database, covering a linage disequilibrium region of more than 70 Kb at 14q24.1, and then conducted a two-stage study (stage I: 878 cases and 900 controls; stage II: 914 cases and 967 controls) to investigate the associations between these tagging SNPs and risk of breast cancer in a Chinese population. In stage I, two SNPs (rs2842346 and rs17828907) were identified to be significantly associated with breast cancer risk (p=0.030 and 0.027 for genotype distributions, respectively). However, no significant associations were found between these two SNPs and breast cancer risk in either stage II or the combined dataset. These findings suggest that common variants at 14q24.1 might not be associated with the risk of breast cancer in the Chinese population, which will need the replication in additional larger studies.
TNFAIP2 is a crucial gene involved in apoptosis. Single nucleotide polymorphisms (SNPs) in its miRNA binding sites could modulate functions of the miRNA-target genes and thus risk of cancers. In this study, we investigated associations between potentially functional SNPs in the miRNA binding sites of the 3′UTR of TNFAIP2 and gastric cancer risk in a US population.
We conducted a case-control study of 301 gastric cancer patients and 313 cancer-free controls frequency-matched by age, sex and ethnicity. We genotyped four selected TNFAIP2 SNPs (rs8126 T>C, rs710100 G>A, rs1052912 G>A and rs1052823 G>T) and used the logistic regression analysis to assess associations of these SNPs with cancer risk.
The rs8126 CC genotype was associated with a significantly elevated risk of gastric cancer (adjusted OR = 2.00, 95% CI = 1.09–3.64 and P = 0.024), compared with the combined rs8126 TT+TC genotypes, particularly in current drinkers. However, none of other TNFAIP2 SNPs was associated with risk of gastric cancer.
Our data suggested that the TNFAIP2 miRNA binding site rs8126 T>C SNP may be a marker for susceptibility to gastric cancer, and this finding requires further validation by larger studies.
Runs of homozygosity (ROHs) are a class of important but poorly studied genomic variations and may be involved in individual susceptibility to diseases. To better understand ROH and its relationship with lung cancer, we performed a genome-wide ROH analysis of a subset of a previous genome-wide case-control study (1,473 cases and 1,962 controls) in a Han Chinese population. ROHs were classified into two classes, based on lengths, intermediate and long ROHs, to evaluate their association with lung cancer risk using existing genome-wide single nucleotide polymorphism (SNP) data. We found that the overall level of intermediate ROHs was significantly associated with a decreased risk of lung cancer (odds ratio = 0.63; 95% confidence interval: 0.51-0.77; P = 4.78×10−6 ), while the long ROHs seemed to be a risk factor of lung cancer. We also identified one ROH region at 14q23.1 that was consistently associated with lung cancer risk in the study. These results indicated that ROHs may be a new class of variation which may be associated with lung cancer risk, and genetic variants at 14q23.1 may be involved in the development of lung cancer.
lung cancer; runs of homozygosity (ROHs); genome-wide association study
Apoptosis plays a key role in inhibiting tumor growth, progression and resistance to anti-tumor therapy. We hypothesized that genetic variants in apoptotic genes may affect the prognosis of lung cancer. To test this hypothesis, we selected 38 potentially functional single nucleotide polymorphisms (SNPs) from 12 genes (BAX, BCL2, BID, CASP3, CASP6, CASP7, CASP8, CASP9, CASP10, FAS, FASLG and MCL1) involved in apoptosis to assess their prognostic significance in lung cancer in a Chinese case cohort with 568 non-small cell lung cancer (NSCLC) patients. Thirty-five SNPs passing quality control underwent association analyses, 11 of which were shown to be significantly associated with NSCLC survival (P < 0.05). After Cox stepwise regression analyses, 3 SNPs were independently associated with the outcome of NSCLC (BID rs8190315: P = 0.003; CASP9 rs4645981: P = 0.007 and FAS rs1800682: P = 0.016). A favorable survival of NSCLC was significantly associated with the genotypes of BID rs8190315 AG/GG (adjusted HR = 0.65, 95% CI: 0.49-0.88), CASP9 rs4645981 AA (HR = 0.22, 95% CI: 0.07-0.69) and FAS rs1800682 GG (adjusted HR = 0.67, 95% CI: 0.46-0.97). Time-dependent receptor operation curve (ROC) analysis revealed that the area under curve (AUC) at year 5 was significantly increased from 0.762 to 0.819 after adding the risk score of these 3 SNPs to the clinical risk score. The remaining 32 SNPs were not significantly associated with NSCLC prognosis after adjustment for these 3 SNPs. These findings indicate that BID rs8190315, CASP9 rs4645981 and FAS rs1800682 polymorphisms in the apoptotic pathway may be involved in the prognosis of NSCLC in the Chinese population.
apoptosis; polymorphisms; non-small cell lung cancer (NSCLC); prognosis
Adenocarcinoma (AC) and squamous cell carcinoma (SqCC) are two major histological subtypes of lung cancer. Genome-wide association studies (GWAS) have made considerable advances in the understanding of lung cancer susceptibility. Obvious heterogeneity has been observed between different histological subtypes of lung cancer, but genetic determinants in specific to lung SqCC have not been systematically investigated. Here, we performed the GWAS analysis specifically for lung SqCC in 833 SqCC cases and 3,094 controls followed by a two-stage replication in additional 2,223 lung SqCC cases and 6,409 controls from Chinese populations. We found that rs12296850 in SLC17A8-NR1H4 gene region at12q23.1 was significantly associated with risk of lung SqCC at genome-wide significance level [additive model: odds ratio (OR) = 0.78, 95% confidence interval (CI) = 0.72–0.84, P = 1.19×10−10]. Subjects carrying AG or GG genotype had a 26% (OR = 0.74, 95% CI = 0.67–0.81) or 32% (OR = 0.68, 95% CI = 0.56–0.83) decreased risk of lung SqCC, respectively, as compared with AA genotype. However, we did not observe significant association between rs12296850 and risk of lung AC in a total of 4,368 cases with lung AC and 9,486 controls (OR = 0.96, 95% CI = 0.90–1.02, P = 0.173). These results indicate that genetic variations on chromosome 12q23.1 may specifically contribute to lung SqCC susceptibility in Chinese population.
Previous genome-wide association studies (GWAS) strongly suggested the importance of genetic susceptibility for lung cancer. However, the studies specific to different histological subtypes of lung cancer were limited. We performed the GWAS analysis specifically for lung squamous cell carcinoma (SqCC) with 570,009 autosomal SNPs in 833 SqCC cases and 3,094 controls and replicated in additional 2,223 lung SqCC cases and 6,409 controls from Chinese populations (822 SqCC cases and 2,243 controls for the first replication stage and 1,401 SqCC cases and 4,166 controls for the second replication stage). We found a novel association at rs12296850 (SLC17A8-NR1H4) on12q23.1. However, rs12296850 didn't show significant association with risk of lung adenocacinoma (AC) in 4,368 lung AC cases and 9,486 controls. These results indicate that genetic variations on chromosome 12q23.1 may specifically contribute to lung SqCC susceptibility in Chinese population.
Xeroderma pigmentosum group G (XPG) protein is essential for the nucleotide excision repair (NER) system, and genetic variations in XPG/ERCC5 that affect DNA repair capacity may contribute to the risk of tobacco-induced cancers, including squamous cell carcinoma of the head and neck (SCCHN). We investigated the association between XPG/ERCC5 polymorphisms and risk of squamous cell carcinoma of the head and neck (SCCHN).
We genotyped 12 tagging and potentially functional single nucleotide polymorphisms (SNPs) of XPG/ERCC5 in a case-control study of 1,059 non-Hispanic white patients with SCCHN and 1,066 cancer-free age-and sex matched controls and evaluated their associations with SCCHN risk.
Multivariate logistic regression showed that only an intronic tagging SNP (rs4150351A/C) of XPG/ERCC5 was associated with a decreased risk of SCCHN (adjusted OR=0.76, 95% CI=0.62–0.92 for AC vs. AA; adjusted OR=0.81, 95% CI=0.67–0.98 for AC/CC vs. AA), but this association was nonsignificnant after corrections by the permutation test (empirical P=0.105). In the genotype-phenotype correlation analysis using peripheral lymphocytes from 44 SCCHN patients, we found that rs4150351 AC/CC was associated with a statistically significant increase in XPG/ERCC5 mRNA expression.
These findings suggest that genetic variation in XPG/ERCC5 may not affect the SCCHN risk, although rs4150351 C variant genotypes were associated with the increased expression of XPG/ERCC5 mRNA and nonsignificantly decreased risk of SCCHN. Larger population-based and additional functional studies are warranted to validate our findings.
ERCC5; polymorphism; SCCHN; risk
Poly(ADP-ribose) polymerase-1 (PARP-1 catalyzes poly(ADP-ribosyl)ation to various proteins involved in many cellular processes, including DNA damage detection and repair, and cell proliferation and death. PARP-1 has been implicated in human carcinogenesis, but the association between the most-studied PARP-1 V762A polymorphism (rs1136410) and risk of various cancers was reported with inconclusive results.
To assess the association between the PARP-1 V762A polymorphism and cancer risk.
A meta-analysis of 21 studies with 12027 cancer patients and 14106 cancer-free controls was conducted to evaluate the strength of the association using odds ratio (OR) with 95% confidence interval (CI).
Overall, no significant association was found between the PARP-1 V762A polymorphism and cancer risk. In the stratified analyses, however, it was found that the variant A allele of the PARP-1 V762A polymorphism was associated with an increased risk of cancer among Asian populations (VA+AA vs.VV: OR = 1.11, 95% CI: 1.01-1.23; Pheterogeneity = 0.210) but a decreased risk of cancer (VA+AA vs.VV: OR =0.89, 95% CI: 0.80-1.00; Pheterogeneity = 0.004), among Caucasian populations, especially for glioma risk (OR = 0.79, 95% CI: 0.69-0.90; Pheterogeneity = 0.800).
This meta-analysis found evidence for an association of the PARP-1 V 762A polymorphism with increased risk of cancer among Asians but decreased risk of cancer among Caucasians, particularly of glioma. Further well designed studies with large sample sizes of different ethnic populations and different cancer types are warranted to confirm these findings.
DNA repair; Case-control study; Meta-analysis; Polymorphism; Susceptibility
The phosphatidylinositol 3-kinase (PI3K)/PTEN/AKT/mTOR and Ras/Raf/MEK/ERK pathways have been implicated in endometrial tumorigenesis. In this candidate pathway analysis, we investigated associations between genetic variations in these two pathways and both risk and clinical outcomes of endometrial cancer.
We genotyped a total of 48 potentially functional SNPs in 11 key genes (AKT1, AKT2, AKT3, BRAF, FRAP1, KRAS, PDPK1, PIK3CA, PIK3CB, PIK3R1, and PTEN) with the Sequenom genotyping platform in 115 endometrial cancer patients and 230 cancer-free women to evaluate their associations with risk, survival, and recurrence of endometrial cancer.
We found the following: (1) PIK3CA rs6443624 and rs9838411 variants either borderline or significantly decreased risk of endometrial cancer in a dominant model (adjusted odds ratio [OR], 0.62; 95% CI, 0.39–1.00 and 0.59; 95% CI, 0.36–0.95, respectively). Furthermore, there was a statistically significant multiplicative interaction (Pint = 0.036) between these two loci in risk of endometrial cancer. In contrast, the AKT1 rs2498801 genotype significantly increased risk of endometrial cancer (adjusted OR, 1.94; 95% CI, 1.02–3.67 in a recessive model). (2) In Cox regression analyses, three SNPs (PIK3R1 rs1862162, AKT2 rs892119, and PIK3CA rs2699887) showed significant associations with survival of endometrial cancer patients. (3) KRAS rs7312175 and PIK3CA rs6443624 had significant effects on recurrence of endometrial cancer individually and combined in a locus–dosage manner (adjusted Ptrend = 0.003).
These results suggest that common genetic variations in these pathways may modulate risk and clinical outcomes of endometrial cancer. Further replication and functional studies are needed to confirm these findings.
PI3K/PTEN/AKT/mTOR and RAS/RAF/MEK/ERK pathways; Polymorphisms; Endometrial cancer risk; Survival; Recurrence
Recent studies reported associations of the relative telomere length (RTL) and TERT variants with risk of several cancers, which has not been comprehensively investigated in squamous cell carcinoma of the head and neck (SCCHN).
We detected RTL in peripheral blood lymphocytes and genotyped six selected functional single nucleotide polymorphisms (SNPs) of the TERT gene in 888 SCCHN cases and 885 cancer-free controls of non-Hispanic whites.
Overall, we did not observe significant associations between RTL and SCCHN risk (adjusted OR, 0.97; 95% CI, 0.80–1.17 for below versus above the median; Ptrend = 0.618) nor between the six TERT SNPs and SCCHN risk. We also found no associations between RTL and TERT SNPs.
Our results suggest that RTL and TERT functional polymorphisms may not play a major role in the etiology of SCCHN. Large prospective studies are needed to validate our findings.
Although our results suggest no association among RTL, TERT functional polymorphisms, and SCCHN risk, this study may contribute to future meta-analysis.
genetic polymorphisms; Telomere length; TERT; head and neck cancer; molecular epidemiology
Although the role of TNFAIP2 is still unclear, it is an important gene involved in apoptosis, and there are single-nucleotide polymorphisms (SNPs) at its microRNA (miRNA)-binding sites that could modulate miRNA target gene function. In this study, we evaluated associations of four selected SNPs (rs8126 T > C, rs710100 G > A, rs1052912 G > A and rs1052823 G > T) in the miRNA-binding sites of the 3′ untranslated region (UTR) with squamous cell carcinoma of the head and neck (SCCHN) risk in 1077 patients with SCCHN and 1073 cancer-free controls in a non-Hispanic White population. We found that, compared with the rs8126 TT genotype, the variant C allele were associated with increased SCCHN risk in an allele dose–response manner (adjusted odds ratio = 1.48 and 95% confidence interval = 1.06–2.05 for CC, respectively; Ptrend = 0.009). No significant associations were seen for the other three SNPs (rs710100 G > A, rs1052912 G > A and rs1052823 G > T). Additionally, we identified that the rs8126 T > C SNP is within the miR-184 seed binding region in the 3′ UTR of TNFAIP2. Further functional analyses showed that the rs8126 variant C allele led to significantly lower luciferase activity, compared with the T allele. In the genotype–phenotype correlation analysis of peripheral blood mononuclear cells from 64 SCCHN patients, the rs8126 CC genotype was associated with reduced expression of TNFAIP2 messenger RNA. Taken together, these findings indicate that the miR-184 binding site SNP (rs8126 T > C) in the 3′ UTR of TNFAIP2 is functional by modulating TNFAIP2 expression and contributes to SCCHN susceptibility. Larger replication studies are needed to confirm our findings.
MicroRNAs (miRNAs) have been reported to play a key role in oncogenesis. Genetic variations in miRNA processing genes and miRNA binding sites may affect the biogenesis of miRNA and the miRNA-mRNA interactions, hence promoting tumorigenesis. In the present study, we hypothesized that potentially functional polymorphisms in miRNA processing genes may contribute to head and neck cancer (HNC) susceptibility. To test this hypothesis, we genotyped three SNPs at miRNA binding sites of miRNA processing genes (rs1057035 in 3′UTR of DICER, rs3803012 in 3′UTR of RAN and rs10773771 in 3′UTR of HIWI) with a case-control study including 397 HNC cases and 900 controls matched by age and sex in Chinese. Although none of three SNPs was significantly associated with overall risk of HNC, rs1057035 in 3′UTR of DICER was associated with a significantly decreased risk of oral cancer (TC/CC vs. TT: adjusted OR = 0.65, 95% CI = 0.46–0.92). Furthermore, luciferase activity assay showed that rs1057035 variant C allele led to significantly lower expression levels as compared to the T allele, which may be due to the relatively high inhibition of hsa-miR-574-3p on DICER mRNA. These findings indicated that rs1057035 located at 3′UTR of DICER may contribute to the risk of oral cancer by affecting the binding of miRNAs to DICER. Large-scale and well-designed studies are warranted to validate our findings.
Recent genome-wide association studies (GWAS) have found a single nucleotide polymorphism (SNP, rs2274223 A>G) in PLCE1 to be associated with risk of gastric adenocarcinoma. In the present study, we validated this finding and also explored the risk associated with another unreported potentially functional SNP (rs11187870 G>C) of PLCE1 in a hospital-based case-control study of 1059 patients with pathologically confirmed gastric adenocarcinoma and 1240 frequency-matched healthy controls.
We determined genotypes of these two SNPs by the Taqman assay and used logistic regression models to estimate odds ratios (ORs) and 95% confidence intervals (95% CI). We found that a significant higher gastric adenocarcinoma risk was associated with rs2274223 variant G allele (adjusted OR = 1.35, 95% CI = 1.14–1.60 for AG+GG vs. AA) and rs11187870 variant C allele (adjusted OR = 1.26, 95% CI = 1.05–1.50 for CG+CC vs. GG). We also found that the number of combined risk alleles (i.e., rs2274223G and rs11187870C) was associated with risk of gastric adenocarcinoma in an allele-dose effect manner (Ptrend = 0.0002). Stratification analysis indicated that the combined effect of rs2274223G and rs11187870C variant alleles was more evident in subgroups of males, non-smokers, non-drinkers and patients with gastric cardia adenocarcinoma. Further real-time PCR results showed that expression levels of PLCE1 mRNA were significantly lower in tumors than in adjacent noncancerous tissues (0.019±0.002 vs. 0.008±0.001, P<0.05).
Our results further confirmed that genetic variations in PLCE1 may contribute to gastric adenocarcinoma risk in an eastern Chinese population.
Although tobacco and alcohol consumption are the major risk factors of head and neck cancer (HNC), genetic variations of genes involved in several biological pathways, such as DNA repair genes, may affect an individual’s susceptibility to HNC. However, few studies have investigated the associations between polymorphisms in DNA repair genes and HNC risk in the Chinese population. Thus, we genotyped five common, non-synonymous single-nucleotide polymorphisms (SNPs) [APEX1 (Asp148Glu), XRCC1 (Arg399Gln), ADPRT (Val762Ala), XPD (Lys751Gln) and XPG (His1104Asp)] in a hospital-based, case-control study of 397 HNC cases and 900 cancer-free controls in China. The results showed that none of the five SNPs in the DNA repair pathway was significantly associated with HNC risk, suggesting that these polymorphisms may not play a major role in HNC susceptibility in this Chinese population.
DNA repair; polymorphisms; head and neck cancer; risk