Efficient synthesis and anticancer evaluation of spider toxin peptide LVTX-8-based analogues with enhanced stability.

Cytotoxic peptides derived from spider venoms have been considered as promising candidates for anticancer treatment. The novel cell penetrating peptide LVTX-8, which is a 25-residue amphipathic α-helical peptide isolated from spider Lycosa vittata, exhibited potent cytotoxicity and is a potential precursor for further anticancer drug development. Nevertheless, LVTX-8 may be easily degraded by multiple proteases, inducing the proteolytic stability problem and short half-life. In this study, ten LVTX-8-based analogs were rationally designed and the efficient manual synthetic method was established by the DIC/Oxyma based condensation system. The cytotoxicity of synthetic peptides was systematically evaluated against seven cancer cell lines. Seven of the derived peptides exhibited high cytotoxicity towards tested cancer in vitro, which was better than or comparable to that of natural LVTX-8. In particular, both N-acetyl and C-hydrazide modified LVTX-8 (825) and the conjugate methotrexate (MTX)-GFLG-LVTX-8 (827) possessed more durable anticancer efficiency, higher proteolytic stability, as well as lower hemolysis. Finally, we confirmed that LVTX-8 could disrupt the integrity of cell membrane, target the mitochondria and reduce the mitochondrial membrane potential to induce the cell death. Taken together, the structural modifications were conducted on LVTX-8 for the first time and the stability significantly improved derivatives 825 and 827 may provide useful references for the modifications of cytotoxic peptides.

The relationship between blood IL-12p40 level and melanoma progression.

Cytokines such as Interleukin (IL)-12p70 ("IL-12") and IL-23 can influence tumor progression. We tested the hypothesis that blood levels of IL-12p40, the common subunit of both cytokines, are associated with melanoma progression. Blood from 2,048 white melanoma patients were collected at a single institution between March 1998 and March 2011. Plasma levels of IL-12p40 were determined for 573 patients (discovery), 249 patients (Validation 1) and 244 patients (Validation 2). Per 10-unit change of IL-12p40 level was used to investigate associations with melanoma patient outcome among all patients or among patients with early or advanced stage. Among stage I/II melanoma patients in the pooled data set, after adjustment for sex, age, stage and blood draw time from diagnosis, elevated IL-12p40 was associated with melanoma recurrence [hazard ratio (HR) = 1.04 per 10-unit increase in IL-12p40, 95% CI 1.02-1.06, p = 8.48 × 10(-5) ]; Elevated IL-12p40 was also associated with a poorer melanoma specific survival (HR = 1.06, 95% CI 1.03-1.09, p = 3.35 × 10(-5) ) and overall survival (HR = 1.05, 95% CI 1.03-1.08, p = 8.78×10(-7) ) in multivariate analysis. Among stage III/IV melanoma patients in the pooled data set, no significant association was detected between elevated IL-12p40 and overall survival, or with melanoma specific survival, with or without adjustment for the above covariates. Early stage melanoma patients with elevated IL-12p40 levels are more likely to develop disease recurrence and have a poorer survival. Further investigation with a larger sample size will be needed to determine the role of IL-12p40 in advanced stage melanoma patients.

Genome-wide association studies identify several new loci associated with pigmentation traits and skin cancer risk in European Americans.

Aiming to identify novel genetic loci for pigmentation and skin cancer, we conducted a series of genome-wide association studies on hair color, eye color, number of sunburns, tanning ability and number of non-melanoma skin cancers (NMSCs) among 10 183 European Americans in the discovery stage and 4504 European Americans in the replication stage (for eye color, 3871 males in the discovery stage and 2496 males in the replication stage). We targeted novel chromosome regions besides the known ones for replication. As a result, we identified a new region downstream of the EDNRB gene on 13q22 associated with hair color and the strongest association was the single-nucleotide polymorphism (SNP) rs975739 (P = 2.4 × 10(-14); P = 5.4 × 10(-9) in the discovery set and P = 1.2 × 10(-6) in the replication set). Using blue, intermediate (including green) and brown eye colors as co-dominant outcomes, we identified the SNP rs3002288 in VASH2 on 1q32.3 associated with brown eye (P = 7.0 × 10(-8); P = 5.3 × 10(-5) in the discovery set and P = 0.02 in the replication set). Additionally, we identified a significant interaction between the SNPs rs7173419 and rs12913832 in the OCA2 gene region on brown eye color (P-value for interaction = 3.8 × 10(-3)). As for the number of NMSCs, we identified two independent SNPs on chr6 and one SNP on chromosome 14: rs12203592 in IRF4 (P = 7.2 × 10(-14); P = 1.8 × 10(-8) in the discovery set and P = 6.7 × 10(-7) in the replication set), rs12202284 between IRF4 and EXOC2 (P = 5.0 × 10(-8); P = 6.6 × 10(-7) in the discovery set and P = 3.0 × 10(-3) in the replication set) and rs8015138 upstream of GNG2 (P = 6.6 × 10(-8); P = 5.3 × 10(-7) in the discovery set and P = 0.01 in the replication set).

Teenage acne and cancer risk in US women: A prospective cohort study.

BACKGROUND: Acne reflects hormone imbalance and is a key component of several systemic diseases. We hypothesized that diagnosis of acne as a teenager might predict subsequent risk of hormone-related cancers. METHODS: We followed 99,128 female nurses in the Nurses' Health Study II cohort for 20 years (1989-2009) and used Cox proportional hazards models to estimate the hazard ratios (HRs) of 8 specific cancers (breast, thyroid, colorectal, ovarian, cervical, and endometrial cancers, melanoma, and non-Hodgkin lymphoma) for women with a history of severe teenage acne. RESULTS: After thoroughly adjusting for the previously known risk factors for each cancer, we found that among women with a history of severe teenage acne, the relative risk increased, with a multivariable-adjusted HR of 1.44 (95% confidence interval [CI], 1.03-2.01) for melanoma. We replicated this association in an independent melanoma case-control study of 930 cases and 1026 controls (multivariable-adjusted odds ratio, 1.27; 95% CI, 1.03-1.56). We also found that in both studies the individuals with teenage acne were more likely to have moles (52.7% vs 50.1%, P < .001 in the cohort study; and 55.2% vs 45.1%, P = .004 in the case-control study). CONCLUSIONS: Our findings suggest that a history of teenage acne might be a novel risk factor for melanoma independent from the known factors, which supports a need for continued investigation of these relationships.

Genetic polymorphisms in the microRNA binding-sites of the thymidylate synthase gene predict risk and survival in gastric cancer.

Thymidylate synthase (TYMS) plays a crucial role in folate metabolism as well as DNA synthesis and repair. We hypothesized that functional polymorphisms in the 3' UTR of TYMS are associated with gastric cancer risk and survival. In the present study, we tested our hypothesis by genotyping three potentially functional (at miRNA binding sites) TYMS SNPs (rs16430 6bp del/ins, rs2790 A>G and rs1059394 C>T) in 379 gastric cancer patients and 431 cancer-free controls. Compared with the rs16430 6bp/6bp + 6bp/0bp genotypes, the 0bp/0bp genotype was associated with significantly increased gastric cancer risk (adjusted OR = 1.72, 95% CI = 1.15-2.58). Similarly, rs2790 GG and rs1059394 TT genotypes were also associated with significantly increased risk (adjusted OR = 2.52, 95% CI = 1.25-5.10 and adjusted OR = 1.57, 95% CI = 1.04-2.35, respectively), compared with AA + AG and CC + CT genotypes, respectively. In the haplotype analysis, the T-G-0bp haplotype was associated with significantly increased gastric cancer risk, compared with the C-A-6bp haplotype (adjusted OR = 1.34, 95% CI = 1.05-1.72). Survival analysis revealed that rs16430 0bp/0bp and rs1059394 TT genotypes were also associated with poor survival in gastric cancer patients who received chemotherapy treatment (adjusted HR = 1.61, 95% CI = 1.05-2.48 and adjusted HR = 1.59, 95% CI = 1.02-2.48, respectively). These results suggest that these three variants in the miRNA binding sites of TYMS may be associated with cancer risk and survival of gastric cancer patients. Larger population studies are warranted to verify these findings.

Polymorphisms at the microRNA binding-site of the stem cell marker gene CD133 modify susceptibility to and survival of gastric cancer.

CD133 is one of the most common stem cell markers, and functional single nucleotide polymorphisms (SNPs) of CD133 may modulate its gene functions and thus cancer risk and patient survival. We hypothesized that potentially functional CD133 SNPs are associated with gastric cancer (GC) risk and survival. To test this hypothesis, we conducted a case-control study of 371 GC patients and 313 cancer-free controls frequency-matched by age, sex, and ethnicity. We genotyped four selected, potentially functional CD133 SNPs (rs2240688A>C, rs7686732C>G, rs10022537T>A, and rs3130C>T) and used logistic regression analysis for associations of these SNPs with GC risk and Cox hazards regression analysis for survival. We found that compared with the miRNA binding site rs2240688 AA genotype, AC + CC genotypes were associated with significantly increased GC risk (adjusted OR = 1.52, 95% CI = 1.09-2.13); for another miRNA binding site rs3130C>T SNP, the TT genotype was associated with significantly reduced GC risk (adjusted OR = 0.68, 95% CI = 0.48-0.97), compared with CC + CT genotypes. In all patients, the risk rs3130 TT variant genotype was significantly associated with overall survival (OS) (adjusted P(trend) = 0.016 and 0.007 under additive and recessive models, respectively). These findings suggest that these two CD133 miRNA binding site variants, rs2240688 and rs3130, may be potential biomarkers for genetic susceptibility to GC and possible predictors for survival in GC patients but require further validation by larger studies.

Genetic variant rs16430 6bp > 0bp at the microRNA-binding site in TYMS and risk of sporadic breast cancer risk in non-Hispanic white women aged ≤ 55 years.

Thymidylate synthase (TYMS) is involved in the folate metabolism and provision of nucleotides needed for DNA synthesis and repair. Thus, functional genetic variants in TYMS may alter cancer risk. In the study, we evaluated associations of three germline variants (rs2790 A > G, rs16430 6 bp > 0 bp, and rs1059394 C > T) in the predicted miRNA-binding sites of TYMS with risk of sporadic breast cancer in non-Hispanic white women aged ≤ 55. We found that carriers of the rs16430 0 bp variant allele had an increased risk of breast cancer [adjusted odd ratio (OR) = 1.37, 95% confidence interval (CI): 1.08-1.73; P = 0.010], compared with carriers of the 6 bp/6 bp genotype. This increased risk was more evident in older subjects (OR = 1.47, 95% CI = 1.06-2.03, P = 0.022), never smokers (OR = 1.67, 95% CI = 1.23-2.25, P < 0.001), never drinkers (OR = 1.44, 95% CI = 1.01-2.05, P = 0.043), and estrogen receptor-positive patients (OR = 1.46, 95% CI = 1.11-1.92, P = 0.006), regardless of tumor stages. The results are consistent with the functional analyses of rs16430 as previously reported, which showed that the 0 bp allele had a decrease in both luciferase activity by ∼ 70% and mRNA levels by ∼ 50% compared with the 6bp allele. Additionally, the rs16430 variant was predicted to influence the binding activity of miR-561. Taken together, these findings indicate that the TYMS rs16430 may contribute to the etiology of sporadic breast cancer in non-Hispanic white women aged ≤ 55 yr. Further validation in large population-based or cohort studies is needed.

Potentially functional variants in the core nucleotide excision repair genes predict survival in Japanese gastric cancer patients.

Functional genetic variants of DNA repair genes may alter the host DNA repair capacity, and thus influence efficiency of therapies. We genotyped eight potentially functional single nucleotide polymorphisms (SNPs) in genes (i.e. ERCC1, XPA, XPC, XPD and XPG) involved in the nucleotide excision repair (NER) pathway in 496 Japanese gastric cancer patients, and assessed overall survival and recurrence-free survival. The combined effects of risk genotypes of these eight SNPs in Japanese patients were further replicated in 356 North-American gastric cancer patients. In Japanese patients, we found that the XPC rs2228000 TT genotype was associated with shorter overall survival [hazards ratio (HR) = 1.75, 95% confidence interval (95% CI) = 1.07-2.86] and recurrence-free survival (HR = 2.17, 95% CI = 1.19-3.95), compared with CC/CT genotypes, and the XPG rs17655 CC genotype was associated with shorter overall survival (HR = 1.60, 95% CI = 1.08-2.36), compared with GG/CG genotypes. The number of observed risk genotypes in the combined analysis was associated with shorter overall survival and recurrence-free survival in a dose-response manner (P(trend) = 0.006 and P(trend) < 0.000) in Japanese patients; specifically, compared with those with ≤1 risk genotypes, those with ≥2 risk genotypes showed markedly shorter overall survival (HR = 1.79, 95% CI = 1.18-2.70) and recurrence-free survival (HR = 2.80, 95% CI = 1.66-4.73). The association between ≥2 risk genotypes and shorter overall survival was not significant (HR = 1.26, 95% CI = 0.82-1.94) in North-American patients, but the trends were similar in these two groups of patients. These data show that functional SNPs in NER core genes may impact survival in Japanese gastric cancer patients.

A functional variant at the miR-885-5p binding site of CASP3 confers risk of both index and second primary malignancies in patients with head and neck cancer.

Caspases are important regulators and executioners in the apoptosis pathways and play crucial roles in carcinogenesis. We tested the hypothesis that functional variants of CASP genes are associated with risk of squamous cell carcinoma of the head and neck (SCCHN) and second primary malignancy (SPM). We genotyped 7 selected, potentially functional single nucleotide polymorphisms (SNPs) located in the microRNA binding sites of the 3' untranslational region (UTR; 2 in CASP3, 1 in CASP6, and 4 in CASP7) and evaluated their associations first with risk of SCCHN in 1066 patients with SCCHN and 1074 cancer-free control subjects and then with SPM in 846 patients in the same non-Hispanic white study population. We found that compared with the CASP3 TT genotype of rs1049253, the variant TC/CC genotypes were associated with significantly increased risk of SCCHN (adjusted odds ratio=1.29 and 95% confidence interval=1.07-1.56) and SPM (adjusted hazard ratio=1.79 and 95% CI=1.02-3.16) and worse SPM-free survival (log-rank P = 0.020), but no associations were found for the other 6 SNPs. We then performed additional experiments to seek functional relevance of the rs1049253 SNP. First, the luciferase activity and miR-885-5p mimic transfection tests suggested that CASP3 was the target of miR-885-5p and that rs1049253T>C resulted in altered regulation of the CASP3 expression. Second, the rs1049253 CC genotype was associated with reduced levels of CASP3 mRNA in peripheral blood mononuclear cells from 118 SCCHN patients and 103 cancer-free control subjects and lower levels of CASP3 protein expression in 11 head and neck cancer cell lines, compared with the TT genotype. Taken together, our data suggest that the miR-885-5p binding site rs1049253T>C SNP in the 3'-UTR of CASP3 modulates CASP3 expression at both mRNA and protein levels and thus contributes to SCCHN susceptibility.

Synergistic Effect of Styrene and Carbon Black on the Fatigue Properties of Styrene-Butadiene Rubber Composites.

The increase in the styrene content in styrene-butadiene rubber (SBR) can improve the abrasion performance and cutting resistance of rubber, which has received attention in the tire industry. The fatigue performance is the main evaluation index of rubber materials applied to tires. In this study, the effect of the styrene content and its interaction with carbon black (CB) on the dynamic fatigue performance and mechanism of SBR were investigated. The results indicated that the dynamic fatigue life of the rubber composite materials was prolonged with increasing styrene content; furthermore, it showed a trend of increasing and then decreasing with increasing CB content. At a certain CB content, styrene and CB displayed a synergistic effect on improving the dynamic fatigue life of the composite materials. The dynamic fatigue performance of SBR40/CB20 was the best. The expansion of the fatigue cracks followed the secondary cracking mechanism, which consumed a large amount of strain energy and slowed the development of the main crack. However, when the CB content exceeded 40 phr, the mechanism transformed to main crack self-propagation and the fatigue life decreased.

Functional repeats (TGYCC)n in the p53-inducible gene 3 (PIG3) promoter and susceptibility to squamous cell carcinoma of the head and neck.

A polymorphic pentanucleotide microsatellite sequence (TGYCC)n within the p53-inducible gene 3 (PIG3) promoter is correlated with the extent of transcriptional activation by p53 and thought to modulate susceptibility to cancer. Using a PCR-silver staining-based single-strand conformation assay, we visualized variant genotypes of the PIG3 promoter (TGYCC)n motif in a subset of 100 subjects for each of four ethnic groups: non-Hispanic whites, African Americans, Hispanic Americans and Native Chinese. We found that PIG3 (TGYCC)15 was the most common allele but less frequent in non-Hispanic whites (0.660) than in Chinese (0.785) (P = 0.016). In an additional study of 616 patients with squamous cell carcinoma of the head and neck (SCCHN) and 623 cancer-free controls in a non-Hispanic white population, we found that compared with those who were PIG3 (TGYCC)15 homozygotes, subjects without the PIG3 (TGYCC)15 allele had a significantly increased SCCHN risk [adjusted odds ratio (OR) = 1.34; 95% CI = 1.04-1.73 for heterozygotes and OR = 1.69; 95% CI = 1.18-2.44 for variant homozygotes] in an allele-dose response manner (P = 0.002). Consistently, subsequent luciferase reporter assay revealed that the wild-type (TGYCC)15 allele had the highest p53-mediated transcriptional activity, compared with the other (TGYCC)n motifs. Our data suggest that the PIG3 variant polymorphic repeats alleles other than (TGYCC)15 may affect p53 binding and thus may be a marker for susceptibility to SCCHN, but our findings need to be validated in larger studies.

Association between functional polymorphisms in genes involved in the MAPK signaling pathways and cutaneous melanoma risk.

Genome-wide association studies (GWASs) have mainly focused on top significant single nucleotide polymorphisms (SNPs), most of which did not have clear biological functions but were just surrogates for unknown causal variants. Studying SNPs with modest association and putative functions in biologically plausible pathways has become one complementary approach to GWASs. To unravel the key roles of mitogen-activated protein kinase (MAPK) pathways in cutaneous melanoma (CM) risk, we re-evaluated the associations between 47 818 SNPs in 280 MAPK genes and CM risk using our published GWAS dataset with 1804 CM cases and 1026 controls. We initially found 105 SNPs with P ≤ 0.001, more than expected by chance, 26 of which were predicted to be putatively functional SNPs. The risk associations with 16 SNPs around DUSP14 (rs1051849) and a previous reported melanoma locus MAFF/PLA2G6 (proxy SNP rs4608623) were replicated in the GenoMEL dataset (P < 0.01) but failed in the Australian dataset. Meta-analysis showed that rs1051849 in the 3' untranslated regions of DUSP14 was associated with a reduced risk of melanoma (odds ratio = 0.89, 95% confidence interval: 0.82-0.96, P = 0.003, false discovery rate = 0.056). Further genotype-phenotype correlation analysis using the 90 HapMap lymphoblastoid cell lines from Caucasians showed significant correlations between two SNPs (rs1051849 and rs4608623) and messenger RNA expression levels of DUSP14 and MAFF (P = 0.025 and P = 0.010, respectively). Gene-based tests also revealed significant SNPs were over-represented in MAFF, PLA2G6, DUSP14 and other 16 genes. Our results suggest that functional SNPs in MAPK pathways may contribute to CM risk. Further studies are warranted to validate our findings.

Association between a rare novel TP53 variant (rs78378222) and melanoma, squamous cell carcinoma of head and neck and lung cancer susceptibility in non-Hispanic Whites.

Recently, several studies have investigated the association between a newly reported rare functional single nucleotide polymorphism (SNP) in TP53 (rs78378222) and cancer risk, but generated inconsistent findings. The present study further investigated this association with risk of melanoma, squamous cell carcinoma of head and neck (SCCHN) and lung cancer. Using volunteers of non-Hispanic Whites recruited for three large case-control studies, we genotyped the TP53 rs78378222 SNP in 1329 patients with melanoma, 1096 with SCCHN, 1013 with lung cancer and 3000 cancer-free controls. Overall, we did not observe any variant homozygotes in this study population, nor significant associations between the TP53 rs78378222AC genotype or C allele and risk for melanoma (P = 0.680 and 0.682 respectively) and lung cancer (P = 0.379 and 0.382 respectively), but a protection against SCCHN (P = 0.008 and 0.008 respectively), compared with the AA genotype or A allele. An additional meta-analysis including 19,423 cancer patients and 54,050 controls did not support such a risk association either. Our studies did not provide statistical evidence of an association between this rare TP53 variant and increased risk of melanoma, nor of lung cancer, but a possible protection against SCCHN.

Genome-wide association study identifies novel alleles associated with risk of cutaneous basal cell carcinoma and squamous cell carcinoma.

We conducted a genome-wide association study on cutaneous basal cell carcinoma (BCC) among 2045 cases and 6013 controls of European ancestry, with follow-up replication in 1426 cases and 4845 controls. A non-synonymous SNP in the MC1R gene (rs1805007 encoding Arg151Cys substitution), a previously well-documented pigmentation gene, showed the strongest association with BCC risk in the discovery set (rs1805007[T]: OR (95% CI) for combined discovery set and replication set [1.55 (1.45-1.66); P= 4.3 × 10(-17)]. We identified that an SNP rs12210050 at 6p25 near the EXOC2 gene was associated with an increased risk of BCC [rs12210050[T]: combined OR (95% CI), 1.24 (1.17-1.31); P= 9.9 × 10(-10)]. In the locus on 13q32 near the UBAC2 gene encoding ubiquitin-associated domain-containing protein 2, we also identified a variant conferring susceptibility to BCC [rs7335046 [G]; combined OR (95% CI), 1.26 (1.18-1.34); P= 2.9 × 10(-8)]. We further evaluated the associations of these two novel SNPs (rs12210050 and rs7335046) with squamous cell carcinoma (SCC) risk as well as melanoma risk. We found that both variants, rs12210050[T] [OR (95% CI), 1.35 (1.16-1.57); P= 7.6 × 10(-5)] and rs7335046 [G] [OR (95% CI), 1.21 (1.02-1.44); P= 0.03], were associated with an increased risk of SCC. These two variants were not associated with melanoma risk. We conclude that 6p25 and 13q32 are novel loci conferring susceptibility to non-melanoma skin cancer.

Genome-wide association study identifies nidogen 1 (NID1) as a susceptibility locus to cutaneous nevi and melanoma risk.

We conducted a genome-wide association study on the number of melanocytic nevi reported by 9136 individuals of European ancestry, with follow-up replication in 3581 individuals. We identified the nidogen 1 (NID1) gene on 1q42 associated with nevus count (two linked single nucleotide polymorphisms with r(2) > 0.9: rs3768080 A allele associated with reduced count, P = 6.5 × 10(-8); and rs10754833 T allele associated with reduced count, P = 1.5 × 10(-7)). We further determined that the rs10754833 [T] was associated with a decreased melanoma risk in 2368 melanoma cases and 7432 controls [for CT genotype: odds ratio (OR) = 0.86, 95% confidence interval (CI) = 0.75-0.99, P = 0.04; for TT genotype: OR = 0.84, 95% CI = 0.71-0.98, P = 0.03]. Expression level of the NID1 locus was 2-fold higher for the rs10754833 T allele carriers than that with the CC genotype (P = 0.017) in the 87 HapMap CEU cell lines. The NID1 gene is a biologically plausible locus for nevogenesis and melanoma development, with decreased expression levels of NID1 in benign nevi (P = 3.5 × 10(-6)) and in primary melanoma (P = 4.6 × 10(-4)) compared with the normal skin.

Genome-wide association study identifies novel loci predisposing to cutaneous melanoma.

We performed a multistage genome-wide association study of melanoma. In a discovery cohort of 1804 melanoma cases and 1026 controls, we identified loci at chromosomes 15q13.1 (HERC2/OCA2 region) and 16q24.3 (MC1R) regions that reached genome-wide significance within this study and also found strong evidence for genetic effects on susceptibility to melanoma from markers on chromosome 9p21.3 in the p16/ARF region and on chromosome 1q21.3 (ARNT/LASS2/ANXA9 region). The most significant single-nucleotide polymorphisms (SNPs) in the 15q13.1 locus (rs1129038 and rs12913832) lie within a genomic region that has profound effects on eye and skin color; notably, 50% of variability in eye color is associated with variation in the SNP rs12913832. Because eye and skin colors vary across European populations, we further evaluated the associations of the significant SNPs after carefully adjusting for European substructure. We also evaluated the top 10 most significant SNPs by using data from three other genome-wide scans. Additional in silico data provided replication of the findings from the most significant region on chromosome 1q21.3 rs7412746 (P = 6 × 10(-10)). Together, these data identified several candidate genes for additional studies to identify causal variants predisposing to increased risk for developing melanoma.

Obesity-related genetic variants, human pigmentation, and risk of melanoma.

Previous biological studies showed evidence of a genetic link between obesity and pigmentation in both animal models and humans. Our study investigated the individual and joint associations between obesity-related single nucleotide polymorphisms (SNPs) and both human pigmentation and risk of melanoma. Eight obesity-related SNPs in the FTO, MAP2K5, NEGR1, FLJ35779, ETV5, CADM2, and NUDT3 genes were nominally significantly associated with hair color among 5,876 individuals of European ancestry. The genetic score combining 35 independent obesity-risk loci was significantly associated with darker hair color (beta-coefficient per ten alleles = 0.12, P value = 4 × 10(-5)). However, single SNPs or genetic scores showed non-significant association with tanning ability. We further examined the SNPs at the FTO locus for their associations with pigmentation and risk of melanoma. Among the 783 SNPs in the FTO gene with imputation R (2) quality metric >0.8 using the 1,000 genome data set, ten and three independent SNPs were significantly associated with hair color and tanning ability respectively. Moreover, five independent FTO SNPs showed nominally significant association with risk of melanoma in 1,804 cases and 1,026 controls. But none of them was associated with obesity or in linkage disequilibrium with obesity-related variants. FTO locus may confer variation in human pigmentation and risk of melanoma, which may be independent of its effect on obesity.

Genome-wide gene-environment interaction analysis for asbestos exposure in lung cancer susceptibility.

Asbestos exposure is a known risk factor for lung cancer. Although recent genome-wide association studies (GWASs) have identified some novel loci for lung cancer risk, few addressed genome-wide gene-environment interactions. To determine gene-asbestos interactions in lung cancer risk, we conducted genome-wide gene-environment interaction analyses at levels of single nucleotide polymorphisms (SNPs), genes and pathways, using our published Texas lung cancer GWAS dataset. This dataset included 317 498 SNPs from 1154 lung cancer cases and 1137 cancer-free controls. The initial SNP-level P-values for interactions between genetic variants and self-reported asbestos exposure were estimated by unconditional logistic regression models with adjustment for age, sex, smoking status and pack-years. The P-value for the most significant SNP rs13383928 was 2.17×10(-6), which did not reach the genome-wide statistical significance. Using a versatile gene-based test approach, we found that the top significant gene was C7orf54, located on 7q32.1 (P = 8.90×10(-5)). Interestingly, most of the other significant genes were located on 11q13. When we used an improved gene-set-enrichment analysis approach, we found that the Fas signaling pathway and the antigen processing and presentation pathway were most significant (nominal P < 0.001; false discovery rate < 0.05) among 250 pathways containing 17 572 genes. We believe that our analysis is a pilot study that first describes the gene-asbestos interaction in lung cancer risk at levels of SNPs, genes and pathways. Our findings suggest that immune function regulation-related pathways may be mechanistically involved in asbestos-associated lung cancer risk.

Serum microRNA profiling and breast cancer risk: the use of miR-484/191 as endogenous controls.

It has been demonstrated that there are abundant stable microRNAs (miRNAs) in plasma/serum, which can be detected and are potentially disease specific. However, the lack of suitable endogenous controls for serum miRNA detection is the restriction for the widely usage of this kind of biomarkers and for the between-laboratory comparison of the findings. We first systematically screened for endogenous control miRNAs (ECMs) by testing 10 pooling samples (using both Solexa sequencing and TaqMan low density array) and 50 individual samples (using quantitative reverse transcription-PCR) of different cancer traits and healthy controls. Then we assessed serum miRNAs used as potential biomarkers for breast cancer risk prediction based on a two-stage case-control analysis, including 48 breast cancer patients and 48 controls for the discovery stage and 76 breast cancer patients and 76 controls for validation. We identified two candidate ECMs (miRNA-191 and miRNA-484). Normalized by the two ECMs, we found four miRNAs (miR-16, miR-25, miR-222 and miR-324-3p) that were consistently differentially expressed between breast cancer cases and controls. The area under the receiver operating characteristic curve is 0.954 for the four-miRNA signature in the discovery stage (sensitivity = 0.917 and specificity = 0.896) and 0.928 in the validation stage (sensitivity = 0.921 and specificity = 0.934). In conclusion, the four-miRNA signature from serum may serve as a non-invasive prediction biomarker for breast cancer. Furthermore, we proposed the combination of miRNA-484 and miRNA-191 as endogenous control for serum miRNA detection, at least for most common cancers.

Polymorphisms of the vascular endothelial growth factor gene and severe radiation pneumonitis in non-small cell lung cancer patients treated with definitive radiotherapy.

Vascular endothelial growth factor (VEGF) is a major mediator of angiogenesis and lung cancer progression. We hypothesized that VEGF polymorphisms may modulate the risk of radiation pneumonitis (RP) in non-small cell lung cancer (NSCLC) patients treated with definitive radiotherapy. We genotyped three potentially functional VEGF single nucleotide polymorphisms (-460 T > C [rs833061], -634 G > C [rs2010963] and +936 C > T [rs3025039]) and estimated the associations of their genotypes and haplotypes with severe radiation pneumonitis (RP ≥grade 3) in 195 NSCLC patients. We found that the VEGF genotypes of rs2010963 and rs3025039 single nucleotide polymorphisms as well as the -460C/-634G/+936C haplotype were predictors of RP development (adjusted hazard ratio [adjHR] = 2.33, 95% confidence interval [CI], 1.01-5.37, P = 0.047 for CC vs GG genotypes; adjHR = 28.13, 95% CI, 5.24-151.02, P < 0.001 for TT vs CC genotypes; and adjHR = 2.51, 95% CI, 1.27-4.98, P = 0.008 for T-C-T vs C-G-C haplotypes). In addition, there was a trend towards reduced RP risk in patients carrying an increased number of protective VEGF genotypes. Our data suggest that VEGF polymorphisms can modulate the risk of radiation pneumonitis in NSCLC patients treated with definitive radiotherapy. Large and independent studies are needed to confirm our findings.