Citations

Abstract Phospholipase C epsilon (PLCε or PLC∈ 1) is a phosphoinositide-specific enzyme phospholipase C that converts phosphatidylinositol 4,5-biphosphate to two intracellular second messengers, diacylglycerol and inositol 1,4,5-trisphosphate, which regulate protein kinase C activity and calcium mobilization, respectively. These responses are involved in the regulation of cell growth, differentiation and oncogenesis. However, the involvement of PLCε in human carcinogenesis, particularly in esophageal cancer, was not been recognized until a susceptible SNP (rs2274223: A5780G:His1927Arg) was recently identified in a large genome-wide association study (GWAS). This SNP, located within exon 26 and C2 domain of the PLCε gene at chromosome 10q23, leads to a nonsynonymous alteration from CAC (A allele, encoding histidine) to CGC (G allele, encoding arginine), which was associated with an increased risk of both squamous cell carcinoma and esophagus-cardia gastric adenocarcinoma. In the current report, we demonstrate that the presence of the G allele (AG or GG) at this locus leads to increased PLCε mRNA and protein expression in human esophageal cancer tissues and in human esophageal cancer cell lines. The present of G allele also leads o a higher enzyme activity in esophageal cancer cells in vitro. Quantitative analysis of the C2 domain sequences revealed that A:G allelic imbalance is strongly associated with esophageal malignancy. Moreover, the analysis of 10,614 non-cancer subjects from high- and low-risk areas of China demonstrated that the presence of the G allele is strongly associated with moderate to severe esophagitis in the subjects from the high-risk areas of China: 77% of the severe esophagitis individuals in high-risk areas had AG/GG genotypes vs. only 37% of these subjects in low-risk areas (OR 6.03 with 95% CI 1.59-22.9 vs. OR 0.74 with 95% CI 0.33-1.64; p=0.008). These data suggest that the interaction of potential environmental factors with PLCε, particularly in individuals with AG or GG allele, not only exists in high-risk areas for esophageal cancer development in China, but also correlates with the severity of esophagitis. In conclusion, PLCε is likely to play a pivotal role in esophageal carcinogenesis: the presence of the 5780G allele may not only predict a high risk of future esophageal cancer development, but may also participate in esophageal cancer growth and progression by upregulating levels of PLCε mRNA, protein, and enzyme activity, ultimately leading to augmentation of the inflammatory process in esophageal epithelium. Thus, the 5780G allele in PLCε may constitute a promising biomarker for esophageal squamous carcinoma risk stratification, early detection, and progression prediction. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4704. doi:10.1158/1538-7445.AM2011-4704

Abstract Introduction: Genome-wide association studies of colorectal cancer have identified 18 risk variants that explain ∼25% of the hereditable risk of colorectal cancer. These variants are located in intronic, inter-genic or gene-desert regions. To uncover whether some of these variants may have a regulatory function on the expression of near-by genes, we conducted expression quantitative trait loci (eQTL) analyses of these 18 regions. Methods: DNA and RNA were extracted from 40 fresh-frozen paired colon tumor (microsatellite stable and CpG island methylator phenotype-negative) and adjacent normal tissue samples collected by the Colon Cancer Family Registry. Whole genome gene expression assessment was performed in the tumors and adjacent normal tissue with the Affymetrix GeneChip Human Exon 1.0 ST array. Genome-wide SNP data was generated with DNA extracted from the same normal tissue samples using the Affymetrix Genome-Wide Human SNP 6.0 array. Partek software was used to compare the expression levels by genotype for each gene spanning a 2 Mb region up- and down- stream of each of the 18 established risk variants for colorectal cancer. Results: Three of the 18 risk variants (rs10795668, rs4444235, rs9929218) demonstrated significant cis-eQTLs (FDR q-values<0.05). Specifically, differential gene expression was observed in genes neighboring rs10795668 at 10p14 (ATP5C1, q=0.024), rs4444235 at 14q22.2 (DLGAP5, q=0.041), and rs9929218 at 16q22.1 (NOL3, q=0.017; DDX28, q=0.046). In particular, DLGAP5 (discs, large (Drosophila) homolog-associated protein 5) at 14q22.2 and NOL3 (nucleolar protein 3) at 16q22 are interesting candidate genes for colorectal cancer. DLGAP5 encodes for a microtubule-associated protein and functions as a mitotic regulator that has been reported to be overexpressed in colon tumors. NOL3 (nucleolar protein 3) encodes for an anti-apoptotic protein that down-regulates the expression of caspase 2 and 8, and p53. NOL3 also appears to be overexpressed in colorectal tumors. Conclusion: In summary, these findings suggest putative functional activities for three established colorectal risk variants and highlight potentially interesting candidate genes for this malignancy. If confirmed, these results may help explain the total genetic risk of the disease, as well as further our understanding of the underlying biology of colorectal cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4732. doi:10.1158/1538-7445.AM2011-4732

AbstractThe biological role of vitamin D receptors (VDR), which are abundantly expressed in developing zebrafish (Danio rerio) as early as 48 h after fertilization, and before the development of a mineralized skeleton and mature intestine and kidney, is unknown. We probed the role of VDR in developing zebrafish biology by examining changes in expression of RNA by whole transcriptome shotgun sequencing (RNA-seq) in fish treated with picomolar concentrations of the VDR ligand and hormonal form of vitamin D3, 1α,25-dihydroxyvitamin D3 [1α,25(OH)2D3)].We observed significant changes in RNAs of transcription factors, leptin, peptide hormones, and RNAs encoding proteins of fatty acid, amino acid, xenobiotic metabolism, receptor-activator of NFκB ligand (RANKL), and calcitonin-like ligand receptor pathways. Early highly restricted, and subsequent massive changes in more than 10% of expressed cellular RNA were observed. At days post fertilization (dpf) 2 [24 h 1α,25(OH)2D3-treatment], only four RNAs were differentially expressed (hormone vs. vehicle). On dpf 4 (72 h treatment), 77 RNAs; on dpf 6 (120 h treatment) 1039 RNAs; and on dpf 7 (144 h treatment), 2407 RNAs were differentially expressed in response to 1α,25(OH)2D3. Fewer RNAs (n = 481) were altered in dpf 7 larvae treated for 24 h with 1α,25(OH)2D3vs. those treated with hormone for 144 h. At dpf 7, in 1α,25(OH)2D3-treated larvae, pharyngeal cartilage was larger and mineralization was greater. Changes in expression of RNAs for transcription factors, peptide hormones, and RNAs encoding proteins integral to fatty acid, amino acid, leptin, calcitonin-like ligand receptor, RANKL, and xenobiotic metabolism pathways, demonstrate heretofore unrecognized mechanisms by which 1α,25(OH)2D3 functions in vivo in developing eukaryotes.

Abstract Short constitutional telomere length has been associated with aging and cancer, but how telomere length is affected by other epidemiologic or environmental variables in health has not been thoroughly studied. Understanding these associations with telomere length in health is important for studies to evaluate the relationship of telomere length and diseases such as cancer. We measured peripheral blood leukocyte DNA telomere length with quantitative PCR in 1977 non-related healthy controls collected through the Colon Cancer Family Registry (an NCI cooperative group) and through the Mayo Biobank and Biobank for Gastrointestinal Health Research, two IRB approved prospective biospecimen collections based at Mayo Clinic, Rochester, MN. The controls were a median age of 50.6 years old, and 49.6% of the controls were male. Ninety-six percent of the controls were white; 1.8% were Asian, and <1% were either black, Pacific Islander, or Native American. Less than 1% of controls were Hispanic. On univariate analysis, as age increased, telomere length decreased (Pearson correlation coefficient = −0.07, 95% CI: −0.11, −0.03). Telomeres were longer in people who consumed more fruits (p<0.01) and vegetables (p<0.01); took aspirin on a regular basis (p<0.01); or had a family history of cancers of any type (p=0.05). Women had longer telomeres than men (p=0.03). Telomeres were shorter in people who consumed alcohol (p<0.01), took folate on a regular basis (p=0.01), or who consumed red meat (p<0.01). Statistical significance was not found in the following variables: tobacco use, diagnosis of diabetes, intake of calcium, use of hormone replacement therapy in women, or body mass index. On multivariate analysis, age, vegetable consumption, family history of colorectal cancer or any type of cancer, and folate intake were identified as being significantly associated with telomere length. Telomere length may be associated with multiple environmental and demographic variables in healthy individuals, and adjusting for these may be important for studies that test for an association between telomere length and diseases such as cancer. Citation Information: Cancer Prev Res 2011;4(10 Suppl):A82.

OBJECTIVE To describe trends of primary efficacy and safety outcomes of islet transplantation in type 1 diabetes recipients with severe hypoglycemia from the Collaborative Islet Transplant Registry (CITR) from 1999 to 2010. RESEARCH DESIGN AND METHODS A total of 677 islet transplant-alone or islet-after-kidney recipients with type 1 diabetes in the CITR were analyzed for five primary efficacy outcomes and overall safety to identify any differences by early (1999–2002), mid (2003–2006), or recent (2007–2010) transplant era based on annual follow-up to 5 years. RESULTS Insulin independence at 3 years after transplant improved from 27% in the early era (1999–2002, n = 214) to 37% in the mid (2003–2006, n = 255) and to 44% in the most recent era (2007–2010, n = 208; P = 0.006 for years-by-era; P = 0.01 for era alone). C-peptide ≥0.3 ng/mL, indicative of islet graft function, was retained longer in the most recent era (P < 0.001). Reduction of HbA1c and resolution of severe hypoglycemia exhibited enduring long-term effects. Fasting blood glucose stabilization also showed improvements in the most recent era. There were also modest reductions in the occurrence of adverse events. The islet reinfusion rate was lower: 48% by 1 year in 2007–2010 vs. 60–65% in 1999–2006 (P < 0.01). Recipients that ever achieved insulin-independence experienced longer duration of islet graft function (P < 0.001). CONCLUSIONS The CITR shows improvement in primary efficacy and safety outcomes of islet transplantation in recipients who received transplants in 2007–2010 compared with those in 1999–2006, with fewer islet infusions and adverse events per recipient.

Abstract —The objective of the present study was to assess whether the influences of gender, age, or measures of body size on blood pressure are homogeneous among genotypes of the insertion/deletion (I/D) polymorphism of the gene that codes for angiotensin-converting enzyme (ACE). We studied a sample of 1875 non-Hispanic white individuals (988 female and 887 male subjects) between 5 and 90 years of age from the general population of Rochester, Minn. When statistical interactions between effects associated with the I/D polymorphism and age, height, and weight were not considered, there was no evidence of a significant relationship between variation in blood pressure level or diagnostic category (hypertension versus normotension) and variation in ACE genotype in either gender. However, in females 5 to 29.9 years of age, the linear regression relationships of systolic blood pressure level with age and weight and of diastolic blood pressure level with age were significantly heterogeneous among ACE genotypes. For these concomitant traits, the rank order of expected blood pressure levels associated with each genotype reversed from low values of the concomitant, in which blood pressure was lower for I/D heterozygotes than for II or DD homozygous, to high levels of the concomitant, in which blood pressure was higher for I/D heterozygotes than for II or DD homozygotes. In male subjects 50 to 90 years of age, the logistic regression relationship of the probability of having hypertension with height was also heterogeneous among ACE genotypes; it was statistically significant in II homozygotes but not statistically significant in either I/D heterozygotes or DD homozygotes. Findings of this study are consistent with the conclusion that the influence of variation in the ACE gene on interindividual variation in blood pressure is dependent on contexts that are indexed by gender, age, and measures of body size.

Background —Elevated blood pressure is a risk factor for cardiovascular, cerebrovascular, and renal diseases. Complex mechanisms of blood pressure regulation pose a challenge to identifying genetic factors that influence interindividual blood pressure variation in the population at large. Methods and Results —We performed a genome-wide linkage analysis of systolic blood pressure in humans using an efficient, highly discordant, full-sibling design. We identified 4 regions of the human genome that show statistical significant linkage to genes that influence interindividual systolic blood pressure variation (2p22.1 to 2p21, 5q33.3 to 5q34, 6q23.1 to 6q24.1, and 15q25.1 to 15q26.1). These regions contain a number of candidate genes that are involved in physiological mechanisms of blood pressure regulation. Conclusions —These results provide both novel information about genome regions in humans that influence interindividual blood pressure variation and a basis for identifying the contributing genes. Identification of the functional mutations in these genes may uncover novel mechanisms for blood pressure regulation and suggest new therapies and prevention strategies.

Background —Unstable angina (UA) is associated with systemic inflammation and with expansion of interferon-γ–producing T lymphocytes. The cause of T-cell activation and the precise role of activated T cells in plaque instability are not understood. Methods and Results —Peripheral blood T cells from 34 patients with stable angina and 34 patients with UA were compared for the distribution of functional T-cell subsets by flow cytometric analysis. Clonality within the T-cell compartment was identified by T-cell receptor spectrotyping and subsequent sequencing. Tissue-infiltrating T cells were examined in extracts from coronary arteries containing stable or unstable plaque. The subset of CD4 + CD28 null T cells was expanded in patients with UA and infrequent in patients with stable angina (median frequencies: 10.8% versus 1.5%, P <0.001). CD4 + CD28 null T cells included a large monoclonal population, with 59 clonotypes isolated from 20 UA patients. T-cell clonotypes from different UA patients used antigen receptors with similar sequences. T-cell receptor sequences derived from monoclonal T-cell populations were detected in the culprit but not in the nonculprit lesion of a patient with fatal myocardial infarction. Conclusions —UA is associated with the emergence of monoclonal T-cell populations, analogous to monoclonal gammopathy of unknown significance. Shared T-cell receptor sequences in clonotypes of different patients implicate chronic stimulation by a common antigen, for example, persistent infection. The unstable plaque but not the stable plaque is invaded by clonally expanded T cells, suggesting a direct involvement of these lymphocytes in plaque disruption.