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1.  Effects of MDM2 promoter polymorphisms and p53 codon 72 polymorphism on risk and age at onset of squamous cell carcinoma of the head and neck 
Molecular carcinogenesis  2011;50(9):697-706.
Both p53 tumor suppressor and murine double minute 2 (MDM2) oncoprotein are crucial in carcinogenesis. We hypothesized that MDM2 promoter single nucleotide polymorphism (SNP)309, A2164G, and p53 codon 72 SNP are associated with risk and age at onset of squamous cell carcinoma of head and neck (SCCHN). We genotyped these SNPs in a study of 1,083 Caucasian SCCHN cases and 1,090 cancer-free controls. Although none of these SNPs individually had a significant effect on risk of SCCHN, nor did their combined putative risk genotypes (i.e. MDM2 SNP309 GT + GG, 2164 AA, and p53 codon 72 CC), we found that individuals with 2–3 risk genotypes had significantly increased risk of non-oropharyngeal cancer (OR = 1.42; 95% CI=1.07–1.88). This increased risk was more pronounced among young subjects, men, smokers, and drinkers. In addition, female patients carrying the MDM2 SNP309 GT and GG genotypes showed a 3-year (56.7 years) and 9-year (51.2 years) earlier age at onset of non-oropharyngeal cancer (Ptrend = 0.007), respectively, compared with those carrying the TT genotype (60.1 years). The youngest age (42.5 years) at onset of non-oropharyngeal cancer was observed in female patients with the combined MDM2 SNP309 GG and p53 codon 72 CC genotypes. The findings suggest that MDM2 SNP309, A2164G, and p53 codon 72 SNPs may collectively contribute to non-oropharyngeal cancer risk and that MDM2 SNP309 individually or in combination with p53 codon 72 may accelerate the development of non-oropharyngeal cancer in women. Further studies with large sample sizes are warranted to validate these results.
doi:10.1002/mc.20806
PMCID: PMC3142329  PMID: 21656578
squamous cell carcinoma of the head and neck; MDM2; p53; polymorphism; risk; age at onset
2.  Association between Single Nucleotide Polymorphisms in ERCC4 and Risk of Squamous Cell Carcinoma of the Head and Neck 
PLoS ONE  2012;7(7):e41853.
Background
Excision repair cross-complementation group 4 gene (ERCC4/XPF) plays an important role in nucleotide excision repair and participates in removal of DNA interstrand cross-links and DNA double-strand breaks. Single nucleotide polymorphisms (SNPs) in ERCC4 may impact repair capacity and affect cancer susceptibility.
Methodology/Principal Findings
In this case-control study, we evaluated associations of four selected potentially functional SNPs in ERCC4 with risk of squamous cell carcinoma of the head and neck (SCCHN) in 1,040 non-Hispanic white patients with SCCHN and 1,046 cancer-free matched controls. We found that the variant GG genotype of rs2276466 was significantly associated with a decreased risk of SCCHN (OR = 0.69, 95% CI 0.50–0.96), and that the variant TT genotype of rs3136038 showed a borderline significant decreased risk with SCCHN (OR = 0.76, 95% CI: 0.58–1.01) in the recessive model. Such protective effects were more evident in oropharyngeal cancer (OR = 0.61, 95% CI: 0.40–0.92 for rs2276466; OR = 0.69, 95% CI: 0.48–0.98 for rs3136038). No significant associations were found for the other two SNPs (rs1800067 and rs1799798). In addition, individuals with the rs2276466 GG or with the rs3136038 TT genotypes had higher levels of ERCC4 mRNA expression than those with the corresponding wild-type genotypes in 90 Epstein-Barr virus-transformed lymphoblastoid cell lines derived from Caucasians.
Conclusions
These results suggest that these two SNPs (rs2276466 and rs3136038) in ERCC4 may be functional and contribute to SCCHN susceptibility. However, our findings need to be replicated in further large epidemiological and functional studies.
doi:10.1371/journal.pone.0041853
PMCID: PMC3407112  PMID: 22848636
3.  Association between a Functional Polymorphism (-1195T>C) in the IGFBP5 Promoter and Head and Neck Cancer Risk 
Head & neck  2010;33(5):650-660.
Background
No studies have evaluated roles of insulin-like growth factor binding protein 5 (IGFBP-5) polymorphisms in risk of squamous cell carcinoma of the head and neck (SCCHN).
Methods
A hospital-based study of 1082 SCCHN patients and 1120 cancer-free controls was performed to investigate associations between two functional polymorphisms -1195T>C and -709G>C in the IGFBP5 promoter region and SCCHN risk.
Results
We demonstrated that the transcription factor AP-1 differentially bound to T or C variants at -1195 in the promoter to regulate the IGFBP5 promoter activity and that the C variant genotypes were associated with deferential risk of late-stage SCCHN, compared with the TT genotype, particularly for HPV-unrelated sites (adjusted OR, 2.21; 95% CI, 1.19-4.11 for CC vs. TT).
Conclusion
The IGFBP5 -1195T>C polymorphism is functional and may potentially be a biomarker for susceptibility to late-stage SCCHN.
doi:10.1002/hed.21514
PMCID: PMC3023825  PMID: 20949447
IGFBP5; head neck cancer; TNM stage; polymorphism; association
4.  A novel functional DEC1 promoter polymorphism −249T>C reduces risk of squamous cell carcinoma of the head and neck 
Carcinogenesis  2010;31(12):2082-2090.
Human DEC1 (deleted in esophageal cancer 1) gene is located on chromosome 9q, a region frequently deleted in various types of human cancers, including squamous cell carcinoma of the head and neck (SCCHN). However, only one epidemiological study has evaluated the association between DEC1 polymorphisms and cancer risk. In this hospital-based case–control study, four potentially functional single-nucleotide polymorphisms −1628 G>A (rs1591420), −606 T>C [rs4978620, in complete linkage disequilibrium with −249T>C (rs2012775) and −122 G>A(rs2012566)], c.179 C>T p.Ala60Val (rs2269700) and 3′ untranslated region-rs3750505 as well as the TP53 tumor suppressor gene codon 72 (Arg72Pro, rs1042522) polymorphism were genotyped in 1111 non-Hispanic Whites SCCHN patients and 1130 age-and sex-matched cancer-free controls. After adjustment for age, sex and smoking and drinking status, the variant −606CC (i.e. −249CC) homozygotes had a significantly reduced SCCHN risk (adjusted odds ratio = 0.71, 95% confidence interval = 0.52–0.99) compared with the −606TT homozygotes. Stratification analyses showed that a reduced risk associated with the −606CC genotype was more pronounced in subgroups of non-smokers, non-drinkers, younger subjects (defined as ≤57 years), carriers of the TP53 Arg/Arg (rs1042522) genotype, patients with oropharyngeal cancer or late-stage SCCHN. Further in silico analysis revealed that the −249 T-to-C change led to a gain of a transcription factor-binding site. Additional functional analysis showed that the −249T-to-C change significantly enhanced transcriptional activity of the DEC1 promoter and the DNA–protein-binding activity. We conclude that the DEC1 promoter −249 T>C (rs2012775) polymorphism is functional, modulating susceptibility to SCCHN among non-Hispanic Whites.
doi:10.1093/carcin/bgq198
PMCID: PMC2994282  PMID: 20935061
5.  The functional IGFBP7 promoter −418G>A polymorphism and Risk of Head and Neck Cancer 
Mutation research  2010;702(1):32-39.
Insulin-like growth factor binding protein 7 (IGFBP7) functions mostly independent of the IGF signaling pathway and acts as a tumor suppressor in multiple cancers, but roles of IGFBP7 genetic variants in cancer remains unknown. In a hospital-based study of 1,065 patients with squamous cell carcinoma of head and neck (SCCHN) and 1,112 cancer-free controls of non-Hispanic whites, we investigated associations between two putatively functional IGFBP7 promoter single nucleotide polymorphisms (SNPs) (−702G>C, rs11573014 and −418G>A, rs4075349) and SCCHN risk. A significantly lower SCCHN risk was observed in those subjects carrying −418AG (adjusted OR=0.82, 95% CI=0.67–0.99) and −418AG+AA (adjusted OR=0.82, 95% CI=0.69–0.99) genotypes than those carrying the −418GG genotype, but not for the −702G>C SNP. However, those subjects carrying two common homozygous genotypes of these two SNPs (−418GG and −702GG) had an increased risk (adjusted OR=1.21, 95% CI=1.00-0.1.46) than did those carrying variant genotypes (−418AG+AA and −702CG+CC). This increased risk was more evident in subgroups of never smokers and subjects with oral cancer. Further functional analysis showed that the IGFBP7 −418A allele had significantly higher promoter and DNA-protein binding activities than did the G allele, suggesting a tumor suppressor role of this allelic change in the SCCHN etiology. We conclude that the functional variant −418 G>C in the IGFBP7 promoter is associated with reduced risk of SCCHN, likely by enhancing the IGFBP7 promoter and DNA-protein binding activities. Larger studies are needed to validate our findings.
doi:10.1016/j.mrgentox.2010.06.012
PMCID: PMC2939148  PMID: 20599521
IGFBP7; case-control study; tumor suppressor gene; head and neck cancer; promoter polymorphism
6.  Polymorphisms of Homologous Recombination Genes and Clinical Outcomes of Non-Small Cell Lung Cancer Patients Treated with Definitive Radiotherapy 
PLoS ONE  2011;6(5):e20055.
The repair of DNA double-strand breaks (DSBs) is the major mechanism to maintain genomic stability in response to irradiation. We hypothesized that genetic polymorphisms in DSB repair genes may affect clinical outcomes among non-small cell lung cancer (NSCLC) patients treated with definitive radio(chemo)therapy. We genotyped six potentially functional single nucleotide polymorphisms (SNPs) (i.e., RAD51 −135G>C/rs1801320 and −172G>T/rs1801321, XRCC2 4234G>C/rs3218384 and R188H/rs3218536 G>A, XRCC3 T241M/rs861539 and NBN E185Q/rs1805794) and estimated their associations with overall survival (OS) and radiation pneumonitis (RP) in 228 NSCLC patients. We found a predictive role of RAD51 −135G>C SNP in RP development (adjusted hazard ratio [HR] = 0.52, 95% confidence interval [CI], 0.31–0.86, P = 0.010 for CG/CC vs. GG). We also found that RAD51 −135G>C and XRCC2 R188H SNPs were independent prognostic factors for overall survival (adjusted HR = 1.70, 95% CI, 1.14–2.62, P = 0.009 for CG/CC vs. GG; and adjusted HR = 1.70; 95% CI, 1.02–2.85, P = 0.043 for AG vs. GG, respectively) and that the SNP-survival association was most pronounced in the presence of RP. Our study suggests that HR genetic polymorphisms, particularly RAD51 −135G>C, may influence overall survival and radiation pneumonitis in NSCLC patients treated with definitive radio(chemo)therapy. Large studies are needed to confirm our findings.
doi:10.1371/journal.pone.0020055
PMCID: PMC3102071  PMID: 21647442
7.  Polymorphisms in the SULF1 gene are associated with early age of onset and survival of ovarian cancer 
Background
SULF1 (sulfatase 1) selectively removes the 6-O-sulphate group from heparan sulfate, changing the binding sites for extracellular growth factors. SULF1 expression has been reported to be decreased in various cancers, including ovarian cancer. We hypothesized that single nucleotide polymorphisms (SNPs) of SULF1 would impact clinicopathologic characteristics.
Methods
We genotyped five common (minor allele frequency>0.05) regulatory SNPs with predicted functionalities (rs2623047 G>A, rs13264163 A>G, rs6990375 G>A, rs3802278 G>A, and rs3087714 C>T) in 168 patients with primary epithelial ovarian cancer, using the polymerase chain reaction-restriction fragment length polymorphism method.
Results
We found that rs2623047 G>A was significantly associated with an early age of onset of ovarian cancer in the G allele dose-response manner (P = 0.027; Ptrend = 0.007) and that rs2623047 GG/GA genotypes were associated with longer progression-free survival; rs6990375 G>A was also associated with the early age of onset in the A allele dose-response manner (P = 0.013; Ptrend= 0.009). The significant differences in age of disease onset persisted among carriers of haplotypes of rs2623047 and rs6990375 (P = 0.014; Ptrend = 0.004). In luciferase reporter gene assays, rs2623047 G allele showed a slightly higher promoter activity than the A allele in the SKOV3 tumorigenic cell line.
Conclusions
These findings suggest that genetic variations in SULF1 may play a role in ovarian cancer onset and prognosis. Further studies with large sample sizes and of the mechanistic relevance of SULF1 SNPs are warranted.
doi:10.1186/1756-9966-30-5
PMCID: PMC3025876  PMID: 21214932

Results 1-7 (7)