Immune deficiency is one of the best characterized and strongest known risk factors for non-Hodgkin lymphoma (NHL). We studied the association between single nucleotide polymorphisms (SNPs) in integrin genes that are important components in human innate immunity and the risk of NHL in a population-based case–control study of women in Connecticut, USA. A total of 373 tag SNPs in 33 gene regions were included in the analysis of 448 cases and 525 controls. The ADAM19 rs11466782 SNP was associated with an increased risk of lymphoma (OR, 1.73; 95 % CI, 1.28–2.35; P additive = 0.0004), and the ICAM3 rs2304240 (OR, 0.67; 95 % CI, 0.52–0.86; P additive = 0.002) and the PTGDR rs708486 SNPs (OR, 0.75; 95 % CI, 0.63–0.90; P additive = 0.002) were associated with reduced risk of lymphoma. Two gene regions (ADAM19 (P=0.009) and ICAM3 (P=0.009)) displayed global associations with lymphoma risk at the P<0.01 level. While our results suggest that genetic polymorphisms in integrin genes may play a role in the genesis of lymphoma in women, they should be viewed as exploratory until they are replicated in additional populations.

The balance between Th1 and Th2 activity is critical in lymphoid cell development and differentiation. Immune dysfunction underlies lymphomagenesis, so an alteration in the regulation of key Th1/Th2 cytokines may lead to the development of non-Hodgkin lymphoma (NHL). To study the impact of polymorphism in Th1/Th2 cytokines on NHL risk, we analyzed 145 tag single nucleotide polymorphisms (SNPs) in 17 Th1/Th2 cytokine and related genes in three population-based case-control studies (1,946 cases and 1,808 controls). Logistic regression was used to compute odds ratios (OR) for NHL and four major NHL subtypes in relation to tag SNP genotypes and haplotypes. A gene-based analysis adjusting for the number of tag SNPs genotyped in each gene showed significant associations with risk of NHL combined and one or more NHL subtypes for Th1 (IL12A and IL12RB1) and Th2 (IL4, IL10RB, and IL18) genes. The strongest association was for IL12A rs485497, which plays a central role in bridging the cellular and humoral pathways of innate resistance and antigen-specific adaptive immune responses (allele risk OR=1.17; P(trend)=0.00099). This SNP was also associated specifically with risk of follicular lymphoma (allele risk OR=1.26; P(trend)=0.0012). These findings suggest that genetic variation in Th1/Th2 cytokine genes may contribute to lymphomagenesis.

The presence of pancreatic cancer (PC) in melanoma-prone families has been consistently associated with an increased frequency of CDKN2A mutations, the major high-risk susceptibility gene identified for melanoma. However, the precise relationship between CDKN2A, melanoma and PC remains unknown. We evaluated a recently identified PC susceptibility gene PALB2 using both sequencing and tagging to determine whether PALB2 might explain part of the relationship between CDKN2A, melanoma, and PC. No disease-related mutations were identified from sequencing PALB2 in multiple pancreatic cancer patients or other mutation carrier relatives of PC patients from the eight melanoma-prone families with CDKN2A mutations and PC. In addition, no significant associations were observed between 11 PALB2 tagging SNPs and melanoma risk in 23 melanoma-prone families with CDKN2A mutations or the subset of 11 families with PC or PC-related CDKN2A mutations. The results suggested that PALB2 does not explain the relationship between CDKN2A, melanoma, and pancreatic cancer in these melanoma-prone families.

The genetic basis of chronic lymphocytic leukemia (CLL) has not been elucidated to date. Although it is the most common hematological malignancy in Caucasians, it is uncommon among Asians. A recent genome-wide scan of CLL in Caucasians identified 6 variants showing strong association. We attempted to replicate these findings in 71 cases of CLL and 1273 controls in Hong Kong Chinese. Three of the 6 variants were significantly associated with CLL. The rs872071 variant (Odds Ratio (95% Confidence Interval) = 1.78 (1.25–2.53), p = 0.0013) in the IRF4 gene region showed the strongest association, similar to that reported in the United Kingdom study. Polymorphisms in SP140 and ACOXL and were also associated with risk of CLL. Further, the mean allele frequencies of the 6 variants were moderately (59%) to extremely (0.5%) lower in the Chinese population compared with Caucasians. These results suggest that variants in three loci may contribute to risk of CLL among Chinese.

We conducted a genome-wide association study of gastric cancer (GC) and esophageal squamous cell carcinoma (ESCC) in ethnic Chinese subjects in which we genotyped 551,152 single nucleotide polymorphisms (SNPs). We report a combined analysis of 2,240 GC cases, 2,115 ESCC cases, and 3,302 controls drawn from five studies. In logistic regression models adjusted for age, sex, and study, multiple variants at 10q23 had genome-wide significance for GC and ESCC independently. A notable signal was rs2274223, a nonsynonymous SNP located in PLCE1, for GC (P=8.40×10−9; per allele odds ratio (OR) = 1.31) and ESCC (P=3.85×10−9; OR = 1.34). The association with GC differed by anatomic subsite. For tumors located in the cardia the association was stronger (P=4.19 × 10−15; OR= 1.57) and for those located in the noncardia stomach it was absent (P=0.44; OR=1.05). Our findings at 10q23 could provide insight into the high incidence rates of both cancers in China.

The high incidence of lung cancer in Xuanwei County, China has been attributed to exposure to indoor smoky coal emissions that contain polycyclic aromatic hydrocarbons. The inflammatory response induced by coal smoke components may promote lung tumor development. We studied the association between single nucleotide polymorphisms (SNP) in genes involved in innate immunity and lung cancer risk in a population-based case-control study (122 cases and 122 controls) in Xuanwei. A total of 1,360 tag SNPs in 149 gene regions were included in the analysis. FCER2 rs7249320 was the most significant SNP (OR: 0.30; 95% CI: 0.16–0.55; P, 0.0001; false discovery rate value, 0.13) for variant carriers. The gene regions ALOX12B/ALOX15B and KLK2 were associated with increased lung cancer risk globally (false discovery rate value < 0.15). In addition, there were positive interactions between KLK15 rs3745523 and smoky coal use (OR: 9.40; P interaction = 0.07), and between FCER2 rs7249320 and KLK2 rs2739476 (OR: 10.77; P interaction = 0.003). Our results suggest that genetic polymorphisms in innate immunity genes may play a role in the carcinogenesis of lung cancer caused by polycyclic aromatic hydrocarbon-containing coal smoke. Integrin/receptor and complement pathways as well as IgE regulation are particular noteworthy.

Benzene is an established human hematotoxicant and leukemogen but its mechanism of action is unclear. To investigate the role of single-nucleotide polymorphisms (SNPs) on benzene-induced hematotoxicity, we analyzed 1395 SNPs in 411 genes using an Illumina GoldenGate assay in 250 benzene-exposed workers and 140 unexposed controls. Highly significant findings clustered in five genes (BLM, TP53, RAD51, WDR79 and WRN) that play a critical role in DNA repair and genomic maintenance, and these regions were then further investigated with tagSNPs. One or more SNPs in each gene were associated with highly significant 10–20% reductions (P values ranged from 0.0011 to 0.0002) in the white blood cell (WBC) count among benzene-exposed workers but not controls, with evidence for gene–environment interactions for SNPs in BLM, WRN and RAD51. Further, among workers exposed to benzene, the genotype-associated risk of having a WBC count <4000 cells/μl increased when using individuals with progressively higher WBC counts as the comparison group, with some odds ratios >8-fold. In vitro functional studies revealed that deletion of SGS1 in yeast, equivalent to lacking BLM and WRN function in humans, caused reduced cellular growth in the presence of the toxic benzene metabolite hydroquinone, and knockdown of WRN using specific short hairpin RNA increased susceptibility of human TK6 cells to hydroquinone toxicity. Our findings suggest that SNPs involved in DNA repair and genomic maintenance, with particular clustering in the homologous DNA recombination pathway, play an important role in benzene-induced hematotoxicity.

Common genetic variation may play an important role in altering lung cancer risk. We conducted a pathway-based candidate gene evaluation to identify genetic variations that may be associated with lung cancer in a population-based case–control study in Xuan Wei, China (122 cases and 111 controls). A total of 1260 single-nucleotide polymorphisms (SNPs) in 380 candidate genes for lung cancer were successfully genotyped and assigned to one of 10 pathways based on gene ontology. Logistic regression was used to assess the marginal effect of each SNP on lung cancer susceptibility. The minP test was used to identify statistically significant associations at the gene level. Important pathways were identified using a test of proportions and the rank truncated product methods. The cell cycle pathway was found as the most important pathway (P = 0.044) with four genes significantly associated with lung cancer (PLA2G6 minP = 0.001, CCNA2 minP = 0.006, GSK3β minP = 0.007 and EGF minP = 0.013), after adjusting for multiple comparisons. Interestingly, most cell cycle genes that were associated with lung cancer in this analysis were concentrated in the AKT signaling pathway, which is essential for regulation of cell cycle progression and cellular survival, and may be important in lung cancer etiology in Xuan Wei. These results should be viewed as exploratory until they are replicated in a larger study.

Genome-wide association studies are discovering relationships between single nucleotide polymorphisms (SNPs) and breast cancer, but the functions of these SNPs are unknown and environmental exposures are likely to be important. We assessed whether breast cancer risk SNPs interacted with ionizing radiation, a known breast carcinogen, among 859 cases and 1083 controls nested in the United States Radiologic Technologists cohort. Among eleven Breast Cancer Association Consortium risk SNPs, we found that the genotype-associated breast cancer risk varied significantly by radiation dose for rs2107425 in the H19 gene (pinteraction=0.001). H19 is a maternally expressed imprinted mRNA that is closely involved in regulating the IGF2 gene and could exert its influence by this or by some other radiation-related pathway.