DNA methylation in the arginase-nitric oxide synthase pathway is associated with exhaled nitric oxide in children with asthma.

RATIONALE: Genetic variation in arginase (ARG) and nitric oxide synthase (NOS) has been associated with exhaled nitric oxide (FeNO) levels in children. Little is known about whether epigenetic variation in these genes modulates FeNO. OBJECTIVES: To evaluate whether DNA methylation in ARG and NOS genes is associated with FeNO. METHODS: A subset of 940 participants in the Children's Health Study were selected for this study. Children were eligible if they had FeNO measurements and buccal cells collected on the same day. CpG loci located in the promoter regions of NOS1, NOS2A, NOS3, ARG1, and ARG2 genes were analyzed. Multiple loci in each gene were evaluated individually and averaged together. DNA methylation was measured using a bisulfite-polymerase chain reaction pyrosequencing assay. Linear regression models were used to investigate the association between DNA methylation and FeNO and whether associations differed by asthma status. MEASUREMENTS AND MAIN RESULTS: DNA methylation in ARG2 was significantly associated with FeNO. A 1% increase in average DNA methylation of ARG2 was associated with a 2.3% decrease in FeNO (95% confidence interval, -4 to -0.6). This association was significantly larger in children with asthma (%diff = -8.7%) than in children with no asthma (%diff = -1.6%; p(int) = 0.01). Differences in FeNO by asthma status were also observed for ARG1 (%diff(asthma) = -4.4%; %diff(non-asthma) = 0.3%; p(int) = 0.02). DNA methylation in NOS genes was not associated with FeNO. CONCLUSIONS: DNA methylation in ARG1 and ARG2 is associated with FeNO in children with asthma and suggests a possible role for epigenetic regulation of nitric oxide production.

The association of tumor microsatellite instability phenotype with family history of colorectal cancer.

Family history is a strong predictor of colorectal cancer risk; however, a diagnosis of colorectal cancer among first-degree relatives has not been systematically investigated as a function of the colorectal cancer molecular subtypes related to tumor microsatellite instability (MSI) status. We investigated whether the observable familial colorectal cancer risks differed according to tumor MSI subtypes, stratified as MSI-High (>30% instability), MSI-Low (<30% instability), and MSS (no instability). Data from 3,143 population-based colorectal cancer cases from five institutions were assessed for family history according to the Amsterdam criteria and the Bethesda guidelines, age at diagnosis, sex, tumor location, and MSI status. The distribution of patient characteristics by MSI status was compared using polytomous logistic regression. Overall, 2.8% colorectal cancer cases met the Amsterdam criteria and 37% met the Bethesda guidelines. There were 14% MSI-High, 13% MSI-Low, and 73% MSS colorectal cancers. MSI-High (P<0.0001) and MSI-Low tumors (P=0.01) were more proximally located than MSS tumors. MSI-High tumors were more common among females (P<0.001). The highest proportion of MSI-High tumors occurred in cases<40 years of age whereas the age-dependent distribution of MSI-Low tumors was unchanged. MSI-High tumors showed a statistically significant association with increasing numbers of first-degree relatives with colorectal cancer (P=0.002); this association disappeared, however, when MSI-High cases meeting Amsterdam criteria were removed from the analysis. MSI-Low tumors did not show a similar association with family history of colorectal cancer. Familial risk associated with MSI-High tumors is primarily driven by the Amsterdam-criteria patients. MSI-Low tumors may represent a distinct subtype of colorectal cancer with respect to certain epidemiologic variables studied here.

DNA methylation patterns of adult survivors of adolescent/young adult Hodgkin lymphoma compared to their unaffected monozygotic twin.

DNA methylation (DNAm) silences gene expression and may play a role in immune dysregulation that is characteristic of adolescent/young adult Hodgkin lymphoma (AYAHL). We used the Infinium HumanMethylation27 BeadChip to quantify DNAm in blood (N = 9 pairs, mean age 57.4 y) or saliva (N = 36 pairs, mean age 50.0 y) from long-term AYAHL survivors and their unaffected co-twins. Epigenetic aging (DNAm age) was calculated using previously described methods and compared between survivors and co-twins using paired t-tests and analyses were stratified by sample type, histology, sex, age at sample collection and time since diagnosis. Differences in blood DNAm age were observed between survivors and unaffected co-twins (64.1 vs. 61.3 years, respectively, p = .04), especially in females (p = .01); no differences in saliva DNAm age were observed. Survivors and co-twins had 74 (in blood DNA) and 6 (in saliva DNA) differentially methylated loci. Our results suggest persistent epigenetic aging in AYAHL survivors long after HL cure.

Impact of Chromosomal Rearrangement upon DNA Methylation Patterns in Leukemia.

Genomic instability, including genetic mutations and chromosomal rearrangements, can lead to cancer development. Aberrant DNA methylation occurs commonly in cancer cells. The aim of this study is to determine the effects of a specific chromosomal lesion the BCR-ABL translocation t(9:22), in establishing DNA methylation profiles in cancer. Materials and methods We compared DNA methylation of 1,505 selected promoter CpGs in chronic myelogenous leukemia (CML), acute lymphoblastic leukemia (ALL) with and without the Philadelphia chromosome t(9:22), CD34+ hematopoietic stem cells transfected with BCR-ABL, and other tumors without BCR-ABL (acute promyelocytic leukemia (APL) and gastrointestinal stromal tumors (GIST). In this study, the DNA methylation profile of CML was more closely related to APL, another myeloid leukemia, than Ph+ ALL. Although DNA methylation profiles were consistent within a specific tumor type, overall DNA methylation profiles were no influenced by BCR-ABL gene translocation in the cancers and tissues studied. We conclude that DNA methylation profiles may reflect the cell of origin in cancers rather than the chromosomal lesions involved in leukemogenesis.

Lower cancer incidence in Amsterdam-I criteria families without mismatch repair deficiency: familial colorectal cancer type X.

CONTEXT: Approximately 60% of families that meet the Amsterdam-I criteria (AC-I) for hereditary nonpolyposis colorectal cancer (HNPCC) have a hereditary abnormality in a DNA mismatch repair (MMR) gene. Cancer incidence in AC-I families with MMR gene mutations is reported to be very high, but cancer incidence for individuals in AC-I families with no evidence of an MMR defect is unknown. OBJECTIVE: To determine if cancer risks in AC-I families with no apparent deficiency in DNA MMR are different from cancer risks in AC-I families with DNA MMR abnormalities. DESIGN, SETTING, AND PARTICIPANTS: Identification (1997-2001) of 161 AC-I pedigrees from multiple population- and clinic-based sources in North America and Germany, with families grouped into those with (group A) or without (group B) MMR deficiency by tumor testing. A total of 3422 relatives were included in the analyses. MAIN OUTCOME MEASURES: Cancer incidence in groups A and B (excluding the 3 affected members used to define each pedigree as AC-I) and computed age- and sex-adjusted standardized incidence ratios (SIRs) using Surveillance, Epidemiology, and End Results data. RESULTS: Group A families from both population- and clinic-based series showed increased incidence of the HNPCC-related cancers. Group B families showed increased incidence only for colorectal cancer (SIR, 2.3; 95% confidence interval, 1.7-3.0) and to a lesser extent than group A (SIR, 6.1; 95% confidence interval, 5.2-7.2) (P<.001). CONCLUSIONS: Families who fulfill AC-I criteria but who have no evidence of a DNA MMR defect do not share the same cancer incidence as families with HNPCC-Lynch syndrome (ie, hereditary MMR deficiency). Relatives in such families have a lower incidence of colorectal cancer than those in families with HNPCC-Lynch syndrome, and incidence may not be increased for other cancers. These families should not be described or counseled as having HNPCC-Lynch syndrome. To facilitate distinguishing these entities, the designation of "familial colorectal cancer type X" is suggested to describe this type of familial aggregation of colorectal cancer.

NOS1 methylation and carotid artery intima-media thickness in children.

BACKGROUND: Nitric oxide (NO) plays an important role in cardiovascular health by maintaining and regulating vascular tone and blood flow. Epigenetic regulation of NO synthase (NOS), the genes responsible for NO production, may affect cardiovascular disease, including the development of atherosclerosis in children. METHODS AND RESULTS: We measured percentage DNA methylation using bisulfite conversion and pyrosequencing assays on DNA from buccal cells provided by 377 participants of the Children's Health Study on whom carotid artery intima-media thickness (CIMT) measurements were also collected. We examined a total of 16 CpG loci located within NOS1, NOS2A, NOS3, ARG1, and ARG2 genes responsible for NO production. CIMT was measured using high-resolution B-mode carotid ultrasound. The association between percentage DNA methylation in ARG and NOS genes with CIMT was evaluated using linear regression adjusted for sex, ethnicity, body mass index, age at CIMT, town of residence, and experimental plate for pyrosequencing reactions. Differences in the association by ethnicity and ancestral group were also evaluated. For a 1% increase in average DNA methylation of NOS1, CIMT increased by 1.2 µm (P=0.02). This association was greater in Hispanic children of Native American descent (ß=2.3; P=0.004) than in non-Hispanic whites (ß=0.3; P=0.71) or Hispanic whites (ß=1.0; P=0.35). CONCLUSIONS: DNA methylation of NOS1 has a plausible role in atherogenesis through regulation of NO production, although ancestry may alter the magnitude of this association.

Copy number variation in the Framingham Heart Study.

In this paper we test for association between copy number variation and diabetes in a subset of individuals from the Framingham Heart Study. We used the 500 k SNP data and called copy number variation using two algorithms: the genome alteration detection algorithm of Pique-Regi et al. and the software Golden Helix. We then tested for association between copy number and diabetes using a gene-based analysis. Our results show little evidence of association between copy number and diabetes status. Furthermore, our results indicate a relatively poor level of agreement between copy number calls resulting from the two programs. We then examined potential causes for this difference in results and the implications for future studies.

Morbid obesity adversely impacts pelvic floor function in females seeking attention for weight loss surgery.

PURPOSE: This study was designed to determine the impact of excess body mass on the prevalence of pelvic floor disorders in morbidly obese females. METHODS: A total of 358 morbidly obese females (body mass index (BMI) >or= 35 kg/m(2)) completed two validated, condition-specific, quality of life questionnaires of pelvic floor dysfunction, which assessed stress/impact in three main domains of pelvic floor disorders: pelvic organ prolapse, colorectal-anal, and urogenital incontinence. Prevalence and severity scores in the study population were compared with data from 37 age-matched nonobese controls (BMI 35 kg/m(2) did not show increased adverse impacts on pelvic floor disorders symptoms. CONCLUSION: More than 90 percent of morbidly obese females experience some degree of pelvic floor disorders, and 50 percent of these females report that symptoms adversely impact quality of life. In morbidly obese females, obesity is as important as obstetric history in predicting pelvic floor dysfunction.