Citations

Significance Tumor cells adapt to hypoxia by modulating energy production and utilization. Endocytosis is an energy-consuming process that is suppressed during hypoxia. Our studies show that Dynamin 2 (DNM2), a key component of endocytic machinery, is transcriptionally suppressed by HIF-1. Genetic and pharmacological inactivation of DNM2 stabilized HIF-1α and HIF-2α. Furthermore, miR-199a, which is encoded from the opposite strand of DNM2 , exerts reciprocal negative regulation upon HIF-1α and HIF-2α. Overexpression of miR-199a decreased HIF-1α and HIF-2α, cell migration, and metastasis. These findings establish a regulatory loop between endocytic pathway and hypoxic response in tumor cells.

AbstractObjectiveElevations in uric acid (UA) and the associated hyperuricaemia are commonly observed secondary to treatment with thiazide diuretics. We sought to identify novel single nucleotide polymorphisms (SNPs) associated with hydrochlorothiazide (HCTZ)‐induced elevations in UA and hyperuricaemia.MethodsA genome‐wide association study of HCTZ‐induced changes in UA was performed in Caucasian and African American participants from the pharmacogenomic evaluation of antihypertensive responses (PEAR) study who were treated with HCTZ monotherapy. Suggestive SNPs were replicated in Caucasians and African Americans from the PEAR study who were treated with HCTZ add‐on therapy. Replicated regions were followed up through expression and pathway analysis.ResultsFive unique gene regions were identified in African Americans (LUC7L2, ANKRD17/COX18, FTO, PADI4 and PARD3B), and one region was identified in Caucasians (GRIN3A). Increases in UA of up to 1.8 mg dL−1 were observed following HCTZ therapy in individuals homozygous for risk alleles, with heterozygotes displaying an intermediate phenotype. Several risk alleles were also associated with an increased risk of HCTZ‐induced clinical hyperuricaemia. A composite risk score, constructed in African Americans using the ‘top’ SNP from each gene region, was strongly associated with HCTZ‐induced UA elevations (P = 1.79 × 10−7) and explained 11% of the variability in UA response. Expression studies in RNA from whole blood revealed significant differences in expression of FTO by rs4784333 genotype. Pathway analysis showed putative connections between many of the genes identified through common microRNAs.ConclusionSeveral novel gene regions were associated with HCTZ‐induced UA elevations in African Americans (LUC7L2, COX18/ANKRD17, FTO, PADI4 and PARD3B), and one region was associated with these elevations in Caucasians (GRIN3A).

New Findings What is the central question of this study? The aim of the study was to evaluate the effect of acute induced systemic inflammation on endothelial function, wave reflection and arterial function in older adults. What is the main finding and its importance? Acute inflammation induced by influenza vaccination did not affect endothelial function in older adults. These findings have never been shown in older adults, and they emphasize the importance of vascular function during systemic arterial inflammation. Acute inflammation reduces flow‐mediated vasodilatation and increases arterial stiffness in young healthy individuals. However, this response has not been studied in older adults. The aim of this study, therefore, was to evaluate the effect of acute induced systemic inflammation on endothelial function and wave reflection in older adults. Furthermore, an acute bout of moderate‐intensity aerobic exercise can be anti‐inflammatory. Taken together, we tested the hypothesis that acute moderate‐intensity endurance exercise, immediately preceding induced inflammation, would be protective against the negative effects of acute systemic inflammation on vascular function. Fifty‐nine healthy volunteers between 55 and 75 years of age were randomized to an exercise or a control group. Both groups received a vaccine (induced inflammation) and sham (saline) injection in a counterbalanced crossover design. Inflammatory markers, endothelial function (flow‐mediated vasodilatation) and measures of wave reflection and arterial stiffness were evaluated at baseline and at 24 and 48 h after injections. There were no significant differences in endothelial function and arterial stiffness between the exercise and control group after induced inflammation. The groups were then analysed together, and we found significant differences in the inflammatory markers 24 and 48 h after induction of acute inflammation compared with sham injection. However, flow‐mediated vasodilatation, augmentation index normalized for heart rate (AIx75) and β‐stiffness did not change significantly. Our results suggest that acute inflammation induced by influenza vaccination did not affect endothelial function in older adults.

Abstract Increased Ras activity levels due to active mutations of Ras are critical for tumorigenesis. These oncogenic Ras mutations are considered to be locked in a permanent “On” state and “constitutively active”. Yet, surprisingly, expression of oncogenic Ras at physiologically levels in genetically engineered mice with “knock-in” mutant Ras has little effect on most cells. Here, we demonstrated that oncogenic K-Ras is not at all constitutively active. Rather, oncogenic K-Ras can be readily activated by upstream stimulants such as diet-induced hormones (eg. Cholecystokinin) and inflammatory stimuli (eg. PGE2 or LPS). However, unlike wild-type Ras, oncogenic K-Ras is very slow to inactivate. This effect on oncogenic K-Ras signaling kinetics leads to dramatically amplified levels of Ras activity initiated by physiologic stimuli. Sustained increase of Ras activity involves a feed-forward loop in which increased Ras activity generates more inflammatory mediators which act as Ras stimulants. High Ras activity led to acinar cell senescence and generated inflammation and fibrosis resembling the histological features of chronic inflammation with abundant precancerous lesions that spontaneously progressed to cancer only in animals expressing physiologic levels of oncogenic Ras. In summary, oncogenic Ras is not constitutively active but predisposes cells to pathological alterations dependent upon Ras activity levels. Since a large population of normal healthy humans harbors Ras mutations, in addition to targeting Ras downstream signaling pathways a reduction of factors that can activate Ras signaling may provide an important alternative cancer preventive value. These data also provide a mechanistic explanation for the link between inflammation, Ras and cancer and provide insights for cancer prevention. Citation Format: Ji Baoan, Huang Haojie, Liu Yan, Daniluk Jaroslaw, Logsdon Craig. Targeting oncogenic Ras activation for cancer prevention. [abstract]. In: Proceedings of the Eleventh Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2012 Oct 16-19; Anaheim, CA. Philadelphia (PA): AACR; Cancer Prev Res 2012;5(11 Suppl):Abstract nr A31.

Context: The BRAF V600E mutation (BRAF-MUT) confers an aggressive phenotype in papillary thyroid carcinoma, but unidentified additional genomic abnormalities may be required for full phenotypic expression. Objective: RNA sequencing (RNA-Seq) was performed to identify genes differentially expressed between BRAF-MUT and BRAF wild-type (BRAF-WT) tumors and to correlate changes to patient clinical status. Design: BRAF-MUT and BRAF-WT tumors were identified in patients with T1N0 and T2–3N1 tumors evaluated in a referral medical center. Gene expression levels were determined (RNA-Seq) and fusion transcripts were detected. Multiplexed capture/detection and digital counting of mRNA transcripts (nCounter, NanoString Technologies) validated RNA-Seq data for immune system-related genes. Patients: BRAF-MUT patients included nine women, three men; nine were TNM stage I and three were stage III. Three (25%) had tumor infiltrating lymphocytes. BRAF-WT included five women, three men; all were stage I, and five (62.5%) had tumor infiltrating lymphocytes. Results: RNA-Seq identified 560 of 13 085 genes differentially expressed between BRAF-MUT and BRAF-WT tumors. Approximately 10% of these genes were related to MetaCore immune function pathways; 51 were underexpressed in BRAF-MUT tumors, whereas 4 (HLAG, CXCL14, TIMP1, IL1RAP) were overexpressed. The four most differentially overexpressed immune genes in BRAF-WT tumors (IL1B; CCL19; CCL21; CXCR4) correlated with lymphocyte infiltration. nCounter confirmed the RNA-Seq expression level data. Eleven different high-confidence fusion transcripts were detected (four interchromosomal; seven intrachromosomal) in 13 of 20 tumors. All in-frame fusions were validated by RT-PCR. Conclusion: BRAF-MUT papillary thyroid cancers have reduced expression of immune/inflammatory response genes compared with BRAF-WT tumors and correlate with lymphocyte infiltration. In contrast, HLA-G and CXCL14 are overexpressed in BRAF-MUT tumors. Sixty-five percent of tumors had between one and three fusion transcripts. Functional studies will be required to determine the potential role of these newly identified genomic abnormalities in contributing to the aggressiveness of BRAF-MUT and BRAF-WT tumors.

Key PointsMGUS patients have significantly increased cortical bone porosity and reduced bone strength relative to matched controls.

Although mosaic autosomal chromosomal abnormalities are being increasingly detected as part of high-density genotyping studies, the clinical correlates are unclear. From an electronic medical record (EMR)–based genome-wide association study (GWAS) of peripheral arterial disease, log-R-ratio and B-allele-frequency data were used to identify mosaic autosomal chromosomal abnormalities including copy number variation and loss of heterozygosity. The EMRs of patients with chromosomal abnormalities and those without chromosomal abnormalities were reviewed to compare clinical characteristics. Among 3336 study participants, 0.75% (n = 25, mean age = 74.8 ± 10.7 years, 64% men) had abnormal intensity plots indicative of autosomal chromosomal abnormalities. A hematologic malignancy was present in 8 patients (32%), of whom 4 also had a solid organ malignancy while 2 patients had a solid organ malignancy only. In 50 age- and sex-matched participants without chromosomal abnormalities, there was a lower rate of hematologic malignancies (2% vs 32%, P < .001) but not solid organ malignancies (20% vs 24%, P = .69). We also report the clinical characteristics of each patient with the observed chromosomal abnormalities. Interestingly, among 5 patients with 20q deletions, 4 had a myeloproliferative disorder while all 3 men in this group had prostate cancer. In summary, in a GWAS of 3336 adults, 0.75% had autosomal chromosomal abnormalities and nearly a third of them had hematologic malignancies. A potential novel association between 20q deletions, myeloproliferative disorders, and prostate cancer was also noted.

Study ObjectiveTo assess the relationship of the 33 single nucleotide polymorphisms (SNPs) previously associated with fasting glucose in Caucasians in genome‐wide association studies (GWAS) with glucose response to antihypertensive drugs shown to increase risk for hyperglycemia and diabetes.DesignRandomized, multicenter clinical trial.PatientsA total of 456 Caucasian men and women with uncomplicated hypertension.Measurements and Main ResultsThe Pharmacogenomic Evaluation of Antihypertensives Responses study evaluated blood pressure and glucose response in uncomplicated hypertensive patients randomized to either atenolol or hydrochlorothiazide (HCTZ) monotherapy, followed by combination therapy with both agents. Association of these SNPs with atenolol‐ or HCTZ‐induced glucose response was evaluated in 456 Caucasian patients using linear regression adjusting for age, sex, body mass index, baseline glucose, baseline insulin, and principal component for ancestry.The SNP rs340874 in the 5′ region of PROX1 gene was significantly associated with atenolol‐induced glucose change (p=0.0013). Participants harboring the C allele of this SNP had greater glucose elevation after approximately 9 weeks of atenolol monotherapy (β = +2.39 mg/dl per C allele), consistent with the direction of effect in fasting glucose GWAS, that showed the C allele is associated with higher fasting glucose.ConclusionThese data suggest that PROX1 SNP rs340874, discovered in fasting glucose GWAS, may also be a pharmacogenetic risk factor for antihypertensive‐induced hyperglycemia. β‐blockers and thiazides may interact with genetic risk factors to increase risk for dysglycemia and diabetes.

This session will focus on lessons learned when developing solutions for real world problems in healthcare. Human factors (HF) practitioners bring unique knowledge, methods, and perspectives to work with clinicians to address numerous defects in the worksystem but require problem-solving skills that focus on solutions. The HF contribution may be in the area of process improvement (e.g., prevention of patient falls), systems design (e.g., designing crashcart), or identification of design flaws so robust intervention may be deployed (e.g., glucose meters). Six human factors practitioners who work within healthcare systems will present real world challenges which were discovered by HF methods, or which have heavy HF implications, but where direct HF influence on design lead to the ultimate effective solution. The session will be designed to lead to a discussion about how HF methods were adapted to individual problems at hand and to focus on developing solutions.