Genome-wide analysis of mitochondrial DNA copy number reveals loci implicated in nucleotide metabolism, platelet activation, and megakaryocyte proliferation.

Mitochondrial DNA copy number (mtDNA-CN) measured from blood specimens is a minimally invasive marker of mitochondrial function that exhibits both inter-individual and intercellular variation. To identify genes involved in regulating mitochondrial function, we performed a genome-wide association study (GWAS) in 465,809 White individuals from the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) consortium and the UK Biobank (UKB). We identified 133 SNPs with statistically significant, independent effects associated with mtDNA-CN across 100 loci. A combination of fine-mapping, variant annotation, and co-localization analyses was used to prioritize genes within each of the 133 independent sites. Putative causal genes were enriched for known mitochondrial DNA depletion syndromes (p = 3.09 × 10-15) and the gene ontology (GO) terms for mtDNA metabolism (p = 1.43 × 10-8) and mtDNA replication (p = 1.2 × 10-7). A clustering approach leveraged pleiotropy between mtDNA-CN associated SNPs and 41 mtDNA-CN associated phenotypes to identify functional domains, revealing three distinct groups, including platelet activation, megakaryocyte proliferation, and mtDNA metabolism. Finally, using mitochondrial SNPs, we establish causal relationships between mitochondrial function and a variety of blood cell-related traits, kidney function, liver function and overall (p = 0.044) and non-cancer mortality (p = 6.56 × 10-4).

Dysphagia, texture modification, the elderly and micronutrient deficiency: a review.

Dysphagia is an underlying symptom of many health issues affecting a person's ability to swallow. Being unable to swallow correctly may limit food intake and subsequently micronutrient status. The elderly may be the most at risk group of suffering dysphagia as well as most likely to be deficient in micronutrients. The use of texture-modified meals is a common approach to increasing dysphagia sufferer's food intake. The modification of food may affect the micronutrient content and currently there is a limited number of studies focusing on micronutrient content of texture-modified meals. This review considers the prevalence of dysphagia within the elderly UK community whilst assessing selected micronutrients. Vitamin B12, C, D, folate, zinc and iron, which are suggested to be most likely deficient in the general elderly UK population, were reviewed. Each micronutrient is considered in terms of prevalence of deficiency, metabolic function, food source and processing stability to provide an overview with respect to elderly dysphagia sufferers.

Genome-wide meta-analysis of variant-by-diuretic interactions as modulators of lipid traits in persons of European and African ancestry.

Hypertension (HTN) is a significant risk factor for cardiovascular morbidity and mortality. Metabolic abnormalities, including adverse cholesterol and triglycerides (TG) profiles, are frequent comorbid findings with HTN and contribute to cardiovascular disease. Diuretics, which are used to treat HTN and heart failure, have been associated with worsening of fasting lipid concentrations. Genome-wide meta-analyses with 39,710 European-ancestry (EA) individuals and 9925 African-ancestry (AA) individuals were performed to identify genetic variants that modify the effect of loop or thiazide diuretic use on blood lipid concentrations. Both longitudinal and cross sectional data were used to compute cohort-specific interaction results, which were then combined through meta-analysis in each ancestry. These ancestry-specific results were further combined through trans-ancestry meta-analysis. Analysis of EA data identified two genome-wide significant (p < 5 × 10-8) loci with single nucleotide variant (SNV)-loop diuretic interaction on TG concentrations (including COL11A1). Analysis of AA data identified one genome-wide significant locus adjacent to BMP2 with SNV-loop diuretic interaction on TG concentrations. Trans-ancestry analysis strengthened evidence of association for SNV-loop diuretic interaction at two loci (KIAA1217 and BAALC). There were few significant SNV-thiazide diuretic interaction associations on TG concentrations and for either diuretic on cholesterol concentrations. Several promising loci were identified that may implicate biologic pathways that contribute to adverse metabolic side effects from diuretic therapy.

Significant variation between SNP-based HLA imputations in diverse populations: the last mile is the hardest.

Four single nucleotide polymorphism (SNP)-based human leukocyte antigen (HLA) imputation methods (e-HLA, HIBAG, HLA*IMP:02 and MAGPrediction) were trained using 1000 Genomes SNP and HLA genotypes and assessed for their ability to accurately impute molecular HLA-A, -B, -C and -DRB1 genotypes in the Human Genome Diversity Project cell panel. Imputation concordance was high (>89%) across all methods for both HLA-A and HLA-C, but HLA-B and HLA-DRB1 proved generally difficult to impute. Overall, <27.8% of subjects were correctly imputed for all HLA loci by any method. Concordance across all loci was not enhanced via the application of confidence thresholds; reliance on confidence scores across methods only led to noticeable improvement (+3.2%) for HLA-DRB1. As the HLA complex is highly relevant to the study of human health and disease, a standardized assessment of SNP-based HLA imputation methods is crucial for advancing genomic research. Considerable room remains for the improvement of HLA-B and especially HLA-DRB1 imputation methods, and no imputation method is as accurate as molecular genotyping. The application of large, ancestrally diverse HLA and SNP reference data sets and multiple imputation methods has the potential to make SNP-based HLA imputation methods a tractable option for determining HLA genotypes.

Large-scale pharmacogenomic study of sulfonylureas and the QT, JT and QRS intervals: CHARGE Pharmacogenomics Working Group.

Sulfonylureas, a commonly used class of medication used to treat type 2 diabetes, have been associated with an increased risk of cardiovascular disease. Their effects on QT interval duration and related electrocardiographic phenotypes are potential mechanisms for this adverse effect. In 11 ethnically diverse cohorts that included 71 857 European, African-American and Hispanic/Latino ancestry individuals with repeated measures of medication use and electrocardiogram (ECG) measurements, we conducted a pharmacogenomic genome-wide association study of sulfonylurea use and three ECG phenotypes: QT, JT and QRS intervals. In ancestry-specific meta-analyses, eight novel pharmacogenomic loci met the threshold for genome-wide significance (P<5 × 10-8), and a pharmacokinetic variant in CYP2C9 (rs1057910) that has been associated with sulfonylurea-related treatment effects and other adverse drug reactions in previous studies was replicated. Additional research is needed to replicate the novel findings and to understand their biological basis.

Generalization and fine mapping of European ancestry-based central adiposity variants in African ancestry populations.

BACKGROUND/OBJECTIVES: Central adiposity measures such as waist circumference (WC) and waist-to-hip ratio (WHR) are associated with cardiometabolic disorders independently of body mass index (BMI) and are gaining clinically utility. Several studies report genetic variants associated with central adiposity, but most utilize only European ancestry populations. Understanding whether the genetic associations discovered among mainly European descendants are shared with African ancestry populations will help elucidate the biological underpinnings of abdominal fat deposition. SUBJECTS/METHODS: To identify the underlying functional genetic determinants of body fat distribution, we conducted an array-wide association meta-analysis among persons of African ancestry across seven studies/consortia participating in the Population Architecture using Genomics and Epidemiology (PAGE) consortium. We used the Metabochip array, designed for fine-mapping cardiovascular-associated loci, to explore novel array-wide associations with WC and WHR among 15 945 African descendants using all and sex-stratified groups. We further interrogated 17 known WHR regions for African ancestry-specific variants. RESULTS: Of the 17 WHR loci, eight single-nucleotide polymorphisms (SNPs) located in four loci were replicated in the sex-combined or sex-stratified meta-analyses. Two of these eight independently associated with WHR after conditioning on the known variant in European descendants (rs12096179 in TBX15-WARS2 and rs2059092 in ADAMTS9). In the fine-mapping assessment, the putative functional region was reduced across all four loci but to varying degrees (average 40% drop in number of putative SNPs and 20% drop in genomic region). Similar to previous studies, the significant SNPs in the female-stratified analysis were stronger than the significant SNPs from the sex-combined analysis. No novel associations were detected in the array-wide analyses. CONCLUSIONS: Of 17 previously identified loci, four loci replicated in the African ancestry populations of this study. Utilizing different linkage disequilibrium patterns observed between European and African ancestries, we narrowed the suggestive region containing causative variants for all four loci.

Systematic evaluation of validated type 2 diabetes and glycaemic trait loci for association with insulin clearance.

AIMS/HYPOTHESIS: Insulin clearance is a highly heritable trait, for which few quantitative trait loci have been discovered. We sought to determine whether validated type 2 diabetes and/or glycaemic trait loci are associated with insulin clearance. METHODS: Hyperinsulinaemic-euglycaemic clamps were performed in two Hispanic-American family cohorts totalling 1329 participants in 329 families. The Metabochip was used to fine-map about 50 previously identified loci for type 2 diabetes, fasting glucose, fasting insulin, 2 h glucose or HbA1c. This resulted in 17,930 variants, which were tested for association with clamp-derived insulin clearance via meta-analysis of the two cohorts. RESULTS: In the meta-analysis, 38 variants located within seven loci demonstrated association with insulin clearance (p < 0.001). The top signals for each locus were rs10241087 (DGKB/TMEM195 [TMEM195 also known as AGMO]) (p = 4.4 × 10(-5)); chr1:217605433 (LYPLAL1) (p = 3.25 × 10(-4)); rs2380949 (GLIS3) (p = 3.4 × 10(-4)); rs55903902 (FADS1) (p = 5.6 × 10(-4)); rs849334 (JAZF1) (p = 6.4 × 10(-4)); rs35749 (IGF1) (p = 6.7 × 10(-4)); and rs9460557 (CDKAL1) (p = 6.8 × 10(-4)). CONCLUSIONS/INTERPRETATION: While the majority of validated loci for type 2 diabetes and related traits do not appear to influence insulin clearance in Hispanics, several of these loci do show evidence of association with this trait. It is therefore possible that these loci could have pleiotropic effects on insulin secretion, insulin sensitivity and insulin clearance.

Insulin clearance: confirmation as a highly heritable trait, and genome-wide linkage analysis.

AIMS/HYPOTHESIS: We have previously documented a high heritability of insulin clearance in a Hispanic cohort. Here, our goal was to confirm the high heritability in a second cohort and search for genetic loci contributing to insulin clearance. METHODS: Hyperinsulinaemic-euglycaemic clamps were performed in 513 participants from 140 Hispanic families. Heritability was estimated for clamp-derived insulin clearance and a two-phase genome-wide linkage scan was conducted using a variance components approach. Linkage peaks were further investigated by candidate gene association analysis in two cohorts. RESULTS: The covariate-adjusted heritability of insulin clearance was 73%, indicating that the majority of the phenotypic variance is due to genetic factors. In the Phase 1 linkage scan, no signals with a logarithm of odds (LOD) score >2 were detected. In the Phase 2 scan, two linkage peaks with an LOD >2 for insulin clearance were identified on chromosomes 15 (LOD 3.62) and 20 (LOD 2.43). These loci harbour several promising candidate genes for insulin clearance, with 12 single nucleotide polymorphisms (SNPs) on chromosome 15 and six SNPs on chromosome 20 being associated with insulin clearance in both Hispanic cohorts. CONCLUSIONS/INTERPRETATION: In a second Hispanic cohort, we confirmed that insulin clearance is a highly heritable trait and identified chromosomal loci that harbour genes regulating insulin clearance. The identification of such genes may improve our understanding of how the body clears insulin, thus leading to improved risk assessment, diagnosis, prevention and therapy of diabetes, as well as of other hyperinsulinaemic disorders, such as the metabolic syndrome and polycystic ovary syndrome.

Candidate loci for insulin sensitivity and disposition index from a genome-wide association analysis of Hispanic participants in the Insulin Resistance Atherosclerosis (IRAS) Family Study.

AIMS/HYPOTHESIS: The majority of type 2 diabetes genome-wide association studies (GWAS) to date have been performed in European-derived populations and have identified few variants that mediate their effect through insulin resistance. The aim of this study was to evaluate two quantitative, directly assessed measures of insulin resistance, namely insulin sensitivity index (S(I)) and insulin disposition index (DI), in Hispanic-American participants using an agnostic, high-density single nucleotide polymorphism (SNP) scan, and to validate these findings in additional samples. METHODS: A two-stage GWAS was performed in Hispanic-American samples from the Insulin Resistance Atherosclerosis Family Study. In Stage 1, 317,000 SNPs were assessed using 229 DNA samples. SNPs with evidence of association with glucose homeostasis and adiposity traits were then genotyped on the entire set of Hispanic-American samples (n = 1,190). This report focuses on the glucose homeostasis traits: S(I) and DI. RESULTS: Although evidence of association did not reach genome-wide significance (p = 5 x 10(-7)), in the combined analysis SNPs had admixture-adjusted p values of p (ADD) = 0.00010-0.0020 with 8 to 41% differences in genotypic means for S(I) and DI. CONCLUSIONS/INTERPRETATION: Several candidate loci were identified that are nominally associated with S(I) and/or DI in Hispanic-American participants. Replication of these findings in independent cohorts and additional focused analysis of these loci is warranted.

Linkage of Crohn's disease-related serological phenotypes: NFKB1 haplotypes are associated with anti-CBir1 and ASCA, and show reduced NF-kappaB activation.

BACKGROUND AND AIMS: Genetics studies of the serum expression of antibodies to microbial antigens may yield important clues to the pathogenesis of Crohn's disease. Our aim was to conduct a linkage study using expression of anti-CBir1, anti-I2, anti-OmpC and ASCA as quantitative traits. METHODS: Expression of antibodies to microbial antigens was measured by enzyme-linked immunosorbant assay (ELISA) and a standard approximately 10 cM whole genome microsatellite study was conducted. Single nucleotide polymorphism genotyping was performed using either Illumina or TaqMan MGB technology. Nuclear factor Kappa B (NF-kappaB) activation in cells from Epstein-Barr virus (EBV)-transformed cell lines was assessed using an electrophoretic mobility shift assay and protein was measured using ELISA and western blotting. RESULTS: Evidence for linkage to anti-CBir1 expression was detected on human chromosome 4 (logarithm of odds (LOD) 1.82 at 91 cM). We therefore directly proceeded to test the association of haplotypes in NFKB1, a candidate gene. One haplotype, H1, was associated with anti-CBir1 (p = 0.003) and another, H3, was associated with ASCA (p = 0.023). Using cell lines from Crohn's disease patients with either H1 or H3, NF-kappaB activation and NF-kappaB p105 and p50 production were significantly lower for patients with H1 compared to patients with H3. CONCLUSIONS: These results suggest that NFKB1 haplotypes induce dysregulation of innate immune responses by altering NF-kappaB expression. The results also show the use of EBV-transformed lymphoblastoid cell lines to conduct phenotypic studies of genetic variation.

Genetic variants in the region harbouring IL2/IL21 associated with ulcerative colitis.

OBJECTIVES: Genetic susceptibility is known to play a large part in the predisposition to the inflammatory bowel diseases (IBDs) known as Crohn's disease (CD) and ulcerative colitis (UC). The IL2/IL21 locus on 4q27 is known to be a common risk locus for inflammatory disease (shown in coeliac disease, type 1 diabetes, rheumatoid arthritis, systemic lupus erythematosus and psoriasis), while the roles that interleukin 2 (IL2) and IL21 play in the immune response also make them attractive candidates for IBD. The objective of this study was to test for association between the IL2/IL21 locus and the IBDs. METHODS: The four single nucleotide polymorphisms (SNPs) in the IL2/IL21 locus most associated with coeliac disease were genotyped in 1590 subjects with IBD and 929 controls from The Netherlands, and then replicated in a North American cohort (2387 cases and 1266 controls) and an Italian cohort (805 cases and 421 controls), yielding a total of 4782 cases (3194 UC, 1588 CD) and 2616 controls. Allelic association testing and a pooled analysis using a Cochran-Mantel-Haenszel test were performed. RESULTS: All four SNPs were strongly associated with UC in all three cohorts and reached genome-wide significance in the pooled analysis (rs13151961 p = 1.35 x 10(-10), rs13119723 p = 8.60 x 10(-8), rs6840978 p = 3.0 7x 10(-8), rs6822844 p = 2.77 x 10(-9)). A moderate association with CD was also found in the pooled analysis (p value range 0.0016-9.86 x 10(-5)). CONCLUSIONS: A strong association for the IL2/IL21 locus with UC was found, which also confirms it as a general susceptibility locus for inflammatory disease.

A genome-wide association scan for acute insulin response to glucose in Hispanic-Americans: the Insulin Resistance Atherosclerosis Family Study (IRAS FS).

AIMS/HYPOTHESIS: This study sought to identify genes and regions in the human genome that are associated with the acute insulin response to glucose (AIRg), an important predictor of type 2 diabetes, in Hispanic-American participants from the Insulin Resistance Atherosclerosis Family Study (IRAS FS). METHODS: A two-stage genome-wide association scan (GWAS) was performed in IRAS FS Hispanic-American samples. In the first stage, 317K single nucleotide polymorphisms (SNPs) were assessed in 229 Hispanic-American DNA samples from 34 families from San Antonio, TX, USA. SNPs with the most significant associations with AIRg were genotyped in the entire set of IRAS FS Hispanic-American samples (n = 1,190). In chromosomal regions with evidence of association, additional SNPs were genotyped to capture variation in genes. RESULTS: No individual SNP achieved genome-wide levels of significance (p < 5 x 10(-7)); however, two regions (chromosomes 6p21 and 20p11) had multiple highly ranked SNPs that were associated with AIRg. Additional genotyping in these regions supported the initial evidence of variants contributing to variation in AIRg. One region resides in a gene desert between PXT1 and KCTD20 on 6p21, while the region on 20p11 has several viable candidate genes (ENTPD6, PYGB, GINS1 and RP4-691N24.1). CONCLUSIONS/INTERPRETATION: A GWAS in Hispanic-American samples identified several candidate genes and loci that may be associated with AIRg. These associations explain a small component of variation in AIRg. The genes identified are involved in phosphorylation and ion transport, and provide preliminary evidence that these processes are important in beta cell response.

MAST3: a novel IBD risk factor that modulates TLR4 signaling.

Inflammatory bowel disease (IBD) is a chronic disorder caused by multiple factors in a genetically susceptible host. Significant advances in the study of genetic susceptibility have highlighted the importance of the innate immune system in this disease. We previously completed a genome-wide linkage study and found a significant locus (IBD6) on chromosome 19p. We were interested in identifying the causal variant in IBD6. We performed a two-stage association mapping study. In stage 1, 1530 single-nucleotide polymorphisms (SNPs) were selected from the HapMap database and genotyped in 761 patients with IBD. Among the SNPs that passed the threshold for replication, 26 were successfully genotyped in 754 additional patients (stage 2). One intronic variant, rs273506, located in the microtubule-associated serine/threonine-protein kinase gene-3 (MAST3), was found to be associated in both stages (pooled P=1.8 x 10(-4)). We identified four MAST3 coding variants, including a non-synonymous SNP rs8108738, correlated to rs273506 and associated with IBD. To test whether MAST3 was expressed in cells of interest, we performed expression assays, which showed abundant expression of MAST3 in antigen-presenting cells and in lymphocytes. The knockdown of MAST3 specifically decreased Toll-like receptor-4-dependent NF-kappaB activity. Our findings are additional proofs of the pivotal role played by modulators of NF-kappaB activity in IBD pathogenesis.

An SNP linkage scan identifies significant Crohn's disease loci on chromosomes 13q13.3 and, in Jewish families, on 1p35.2 and 3q29.

Inflammatory bowel disease (IBD) is a complex genetic disorder of two major phenotypes, Crohn's disease (CD) and ulcerative colitis (UC), with increased risk in Ashkenazi Jews. Twelve genome-wide linkage screens have identified multiple loci, but these screens have been of modest size and have used low-density microsatellite markers. We, therefore, performed a high-density single-nucleotide polymorphism (SNP) genome-wide linkage study of 993 IBD multiply affected pedigrees (25% Jewish ancestry) that contained 1709 IBD-affected relative pairs, including 919 CD-CD pairs and 312 UC-UC pairs. We identified a significant novel CD locus on chromosome 13p13.3 (peak logarithm of the odds (LOD) score=3.98) in all pedigrees, significant linkage evidence on chromosomes 1p35.1 (peak LOD score=3.5) and 3q29 (peak LOD score=3.19) in Jewish CD pedigrees, and suggestive loci for Jewish IBD on chromosome 10q22 (peak LOD score=2.57) and Jewish UC on chromosome 2q24 (peak LOD score=2.69). Nominal or greater linkage evidence was present for most previously designated IBD loci (IBD1-9), notably, IBD1 for CD families at chromosome 16q12.1 (peak LOD score=4.86) and IBD6 in non-Jewish UC families at chromosome 19p12 (peak LOD score=2.67). This study demonstrates the ability of high information content adequately powered SNP genome-wide linkage studies to identify loci not observed in multiple microsatellite-based studies in smaller cohorts.

FEM1A and FEM1B: novel candidate genes for polycystic ovary syndrome.

BACKGROUND: Human homologs (FEM1A, FEM1B, FEM1C) of nematode sex determination genes are candidate genes for polycystic ovary syndrome (PCOS). We previously identified a FEM1A mutation (H500Y) in a woman with PCOS; FEM1B has been implicated in insulin secretion. METHODS: Women with and without PCOS (287 cases, 187 controls) were genotyped for H500Y and six FEM1A single nucleotide polymorphisms (SNPs), five FEM1B SNPs and five FEM1C SNPs. SNPs and haplotypes were determined and tested for association with PCOS and component phenotypes. RESULTS: No subject carried the FEM1A H500Y mutation. FEM1A SNPs rs8111933 (P = 0.001) and rs12460989 (P = 0.046) were associated with an increased likelihood of PCOS whereas FEM1A SNP rs1044386 was associated with a reduced probability of PCOS (P = 0.013). FEM1B SNP rs10152450 and a linked SNP were associated with a reduced likelihood of PCOS (P = 0.005), and lower homeostasis model assessment (HOMA) for beta-cell function (HOMA-%B, P = 0.011) and lower HOMA for insulin resistance (HOMA-IR, P = 0.018). FEM1B SNP rs12909277 was associated with lower HOMA-%B (P = 0.008) and lower HOMA-IR (P = 0.037). Haplotype associations were consistent with SNP results, and also revealed association of FEM1B haplotype TGAGG with increased HOMA-%B (P = 0.007) and HOMA-IR (P = 0.024). FEM1C variants were not associated with PCOS. CONCLUSIONS: This study presents evidence suggesting a role for FEM1A and FEM1B in the pathogenesis of PCOS. Only FEM1B variants were associated with insulin-related traits in PCOS women, consistent with prior evidence linking this gene to insulin secretion. Replication of these associations and mechanistic studies will be necessary to establish the role of these genes in PCOS.

Sequence of a mouse embryo cDNA clone encoding proteolipid subunit 9 (P1) of the mitochondrial H(+)-ATP synthase.

A cDNA clone to an abundantly expressed mRNA in cleavage stage mouse embryos has been sequenced and identified as encoding subunit 9 (P1) of the mitochondrial H(+)-ATP synthase. The deduced amino acid sequence of the mature subunit 9 protein differs in a single residue from the corresponding rat, ovine, bovine and human subunits.

A locus for spondylocarpotarsal synostosis syndrome at chromosome 3p14.

Spondylocarpotarsal synostosis syndrome is a rare autosomal recessive disorder characterised by vertebral fusions, frequently manifesting as an unsegmented vertebral bar, as well as fusions of the carpal and tarsal bones. In a study of three consanguineous families and one non-consanguineous family, linkage analysis was used to establish the chromosomal location of the disease gene. Linkage analysis localised the disease gene to chromosome 3p14. A maximum lod score of 6.49 (q = 0) was obtained for the marker at locus D3S3532 on chromosome 3p. Recombination mapping narrowed the linked region to the 5.7 cM genetic interval between the markers at loci D3S3724 and D3S1300. A common region of homozygosity was found between the markers at loci D3S3724 and D3S1300, defining a physical interval of approximately 4 million base pairs likely to contain the disease gene. Identification of the gene responsible for this disorder will provide insight into the genes that play a role in the formation of the vertebral column and joints.

Comparison of volatiles of cultured and wild sea bream (Sparus aurata) during storage in ice by dynamic headspace analysis/gas chromatography-mass spectrometry.

Cultured and wild sea bream were compared for differences in their volatile components over a 23 day storage period in ice. A total of 60 compounds in cultured and 78 compounds in wild sea bream were tentatively identified (in addition to this, there were 23 unknowns in cultured and 29 unknowns in wild sea bream volatiles). These included aldehydes, ketones, alcohols, aromatics, terpenes, furans, sulfur-containing compounds, an acid, and miscellaneous compounds. Although selection of best fish is a subjective matter, more aldehydes, ketones, aromatics, and terpenes were found in wild sea bream as compared to that of its cultured counterpart. Both sea bream samples exhibited complex volatile profiles over the entire storage period. The combination of several classes of volatile compounds, dependent upon their concentrations and odor thresholds, is responsible for the distinctive and unique flavor of fresh cultured and wild sea bream. Relative concentrations of several compounds (trimethylamine, piperidine, methanethiol, dimethyl disulfide, dimethyl trisulfide, 1-penten-3-ol, 3-methyl-1-butanol, and acetic acid) increased continually throughout the storage period, and these may have the potential to be used as indicators of sea bream quality.

Somatostatin analogs affect proliferation of human thyroid carcinoma cell lines in vitro.

Antiproliferative effects of somatostatin (SRIH) analogs were investigated in human thyroid carcinoma cell lines. Membrane preparations from six human thyroid cell lines, including follicular (RO 87-M-1 and RO 82-W-1), papillary (NPA87), and anaplastic (RO 90-D-1) carcinomas, a follicular adenoma, as well as benign and malignant human thyroid tissues, contained high affinity SRIH-binding sites. Ligand-binding studies ([125I]Tyr11-SRIH) demonstrated mean dissociation constants ranging from 114-224 pmol/L, and 20-154 fmol/mg membrane protein mean receptor sites, in cell lines. Four cell lines were grown for 3 days in monolayers with SRIH analogs (octreotide or MK0678) at concentrations from 0.05-100 nmol/L in serum-free medium to assess changes in cell numbers. At the highest dose, MK0678 produced dose-dependent inhibition of growth in RO 87-M-1 and NPA87, each to about 70% of that in control cells. Octreotide produced dose-dependent stimulation of growth in RO 87-M-1 cells, but caused growth inhibition in NPA87 cells, with loss of effect at the highest dose. RO 82-W-1 did not respond to MK0678, yet caused biphasic inhibition with octreotide (75% and 45% of control cell numbers at 0.05 and 100 nmol/L doses, respectively). Anaplastic cells, RO 90-D-1, did not respond to either analog despite similar ligand binding. Addition of epidermal growth factor (100 micrograms/L) or TSH (200 mU/L) increased the sensitivity of RO 87-M-1 cells to growth inhibition by the lowest dose of MK0678, producing biphasic dose-response curves. In conclusion, the present data demonstrate specific SRIH binding to membranes of thyroid carcinoma cells and tissues as well as discordant growth effects of different SRIH analogs on the same cell lines. This may be a result of differential stimulation and regulation of distinct SRIH receptor subtypes.

Antineoplastic activity of taxol against human anaplastic thyroid carcinoma cell lines in vitro and in vivo.

Anaplastic thyroid carcinoma is a rapidly fatal neoplasm that fails to adequately respond to any known chemotherapeutic regimen. We tested taxol (paclitaxel) against six human anaplastic thyroid carcinoma cell lines (DRO-90, ARO-81, KAT-4, KAT-18, SW-1736, and BHT-101). Each cell line monolayer culture, in log phase growth, was treated with taxol concentrations ranging from 0.001-5.0 mumol/L. Cell numbers, after 24-, 48-, and 72-h growth periods in separate experiments, were expressed as percentages of control cell numbers without taxol. All cell lines showed maximal inhibition with 0.05 mumol/L taxol at 3-28% of control cell numbers. Greater inhibition was seen with longer growth periods. Three cell lines (DRO-90, ARO-81, and KAT-4) were grown as sc xenograft tumors in nude mice for 18-26 days. Treatment groups received sc taxol injections in sites distant from the tumors, whereas control mice received vehicle. All taxol-treated xenografts were inhibited to near-starting volume or disappeared, whereas control xenograft volumes increased 9- to 59-fold. These results suggest that taxol may have beneficial clinical effects in anaplastic thyroid carcinoma patients.