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Lee KY, Leung KS, Ma SL, So HC, Huang D, Tang NLS, Wong MH. Genome-Wide Search for SNP Interactions in GWAS Data: Algorithm, Feasibility, Replication Using Schizophrenia Datasets. Front Genet 2020; 11:1003. [PMID: 33133133 PMCID: PMC7505102 DOI: 10.3389/fgene.2020.01003] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 08/06/2020] [Indexed: 11/13/2022] Open
Abstract
In this study, we looked for potential gene-gene interaction in susceptibility to schizophrenia by an exhaustive searching for SNP-SNP interactions in 3 GWAS datasets (phs000021:phg000013, phs000021:phg000014, phs000167) using our recently published algorithm. The search space for SNP-SNP interaction was confined to 8 biologically plausible ways of interaction under dominant-dominant or recessive-recessive modes. First, we performed our search of all pair-wise combination of 729,454 SNPs after filtering by SNP genotype quality. All possible pairwise interactions of any 2 SNPs (5 × 1011) were exhausted to search for significant interaction which was defined by p-value of chi-square tests. Nine out the top 10 interactions, protein coding genes were partnered with non-coding RNA (ncRNA) which suggested a new alternative insight into interaction biology other than the frequently sought-after protein-protein interaction. Therefore, we extended to look for replication among the top 10,000 interaction SNP pairs and high proportion of concurrent genes forming the interaction pairs were found. The results indicated that an enrichment of signals over noise was present in the top 10,000 interactions. Then, replications of SNP-SNP interaction were confirmed for 14 SNPs-pairs in both replication datasets. Biological insight was highlighted by a potential binding between FHIT (protein coding gene) and LINC00969 (lncRNA) which showed a replicable interaction between their SNPs. Both of them were reported to have expression in brain. Our study represented an early attempt of exhaustive interaction analysis of GWAS data which also yield replicated interaction and new insight into understanding of genetic interaction in schizophrenia.
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Affiliation(s)
- Kwan-Yeung Lee
- Department of Computer Science and Engineering, The Chinese University of Hong Kong, Hong Kong, China
| | - Kwong-Sak Leung
- Department of Computer Science and Engineering, The Chinese University of Hong Kong, Hong Kong, China
| | - Suk Ling Ma
- Department of Psychiatry, The Chinese University of Hong Kong, Hong Kong, China
| | - Hon Cheong So
- Department of Psychiatry, The Chinese University of Hong Kong, Hong Kong, China.,School of Biomedical Science, The Chinese University of Hong Kong, Hong Kong, China.,Hong Kong Branch of CAS Center for Excellence in Animal Evolution and Genetics, School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China.,KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research of Common Diseases, Kunming Institute of Zoology, The Chinese University of Hong Kong, Hong Kong, China.,Margaret K.L. Cheung Research Centre for Management of Parkinsonism, The Chinese University of Hong Kong, Hong Kong, China.,Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China.,Brain and Mind Institute, The Chinese University of Hong Kong, Hong Kong, China
| | | | - Nelson Leung-Sang Tang
- Hong Kong Branch of CAS Center for Excellence in Animal Evolution and Genetics, School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China.,Department of Chemical Pathology and Li Ka Shing Institute of Health Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China.,Functional Genomics and Biostatistical Computing Laboratory, CUHK Shenzhen Research Institute, Shenzhen, China
| | - Man-Hon Wong
- Department of Computer Science and Engineering, The Chinese University of Hong Kong, Hong Kong, China
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Wang R, Xu D, Liu R, Zhao L, Hu L, Wu P. Microsatellite and Single Nucleotide Polymorphisms in the Insulin-Like Growth Factor 1 Promoter with Insulin Sensitivity and Insulin Secretion. Med Sci Monit 2017; 23:3722-3736. [PMID: 28761040 PMCID: PMC5549718 DOI: 10.12659/msm.902956] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Background To investigate associations of the CA microsatellite and rs35767, rs5742612, and rs2288377 polymorphisms and the single nucleotide polymorphism (SNP) haplotypes with and without the CA microsatellite in the IGF1 promoter with insulin sensitivity and secretion. Material/Methods The CA microsatellite and SNPs were genotyped in 389 type 2 diabetes mellitus (T2DM) patients. A 75 g oral glucose tolerance test (OGTT) was given to all the participants. Associations of the genotypes and haplotypes with insulin sensitivity, insulin secretion, glucose tolerance, and insulin-like growth factor 1 (IGF1) were analyzed by ANCOVA (general linear model) and multiple linear regression, after controlling for gender, age, and BMI. Results The CA microsatellite, rs35767 polymorphisms, and SNP haplotypes with or without CA showed no significant association with metabolic parameters. The C allele of rs5742612 was found to be associated with decreased insulin sensitivity (HOMA-S index, β=−0.131, P=0.008; fasting insulin level, β=0.022, P=0.006) and increased insulin secretion (HOMA-B index, β=0.099, P=0.008; insulin AUC, β=0.112, P=0.012). The linear regression model also indicated that the A allele of rs2288377 was associated with decreased insulin sensitivity (HOMA-S index, β=−0.159, P=0.001; fasting insulin, β=0.143, P=0.001) and increased insulin secretion (HOMA-B index, β=0.114, P=0.017; insulin AUC, β=0.042, P=0.002). Conclusions The CA microsatellite and rs35767 have no genotype-related difference in insulin sensitivity or secretion. The rs5742612 and rs2288377 polymorphisms are significantly associated with insulin biology, with the TT genotype exhibiting higher insulin sensitivity and lower insulin secretion compared with carriers of the C allele and A allele, respectively, mostly attributed to the direct functional roles of the two loci.
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Affiliation(s)
- Ruyao Wang
- Graduate School, Tianjin Medical University, Tianjin, China (mainland).,Department of Clinical Laboratory, Tianjin Union Medical Center, Tianjin, China (mainland)
| | - Dandan Xu
- Department of Clinical Laboratory, Tianjin Union Medical Center, Tianjin, China (mainland)
| | - Rui Liu
- Department of Clinical Laboratory, Tianjin Union Medical Center, Tianjin, China (mainland)
| | - Lijie Zhao
- Department of Clinical Laboratory, Tianjin Union Medical Center, Tianjin, China (mainland)
| | - Liling Hu
- Department of Clinical Laboratory, Tianjin Union Medical Center, Tianjin, China (mainland)
| | - Ping Wu
- Department of Clinical Laboratory, Tianjin Union Medical Center, Tianjin, China (mainland)
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Chen HY, Ma SL, Huang W, Ji L, Leung VHK, Jiang H, Yao X, Tang NLS. The mechanism of transactivation regulation due to polymorphic short tandem repeats (STRs) using IGF1 promoter as a model. Sci Rep 2016; 6:38225. [PMID: 27910883 PMCID: PMC5133613 DOI: 10.1038/srep38225] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 11/07/2016] [Indexed: 11/09/2022] Open
Abstract
Functional short tandem repeats (STR) are polymorphic in the population, and the number of repeats regulates the expression of nearby genes (known as expression STR, eSTR). STR in IGF1 promoter has been extensively studied for its association with IGF1 concentration in blood and various clinical traits and represents an important eSTR. We previously used an in-vitro luciferase reporter model to examine the interaction between STRs and SNPs in IGF1 promoter. Here, we further explored the mechanism how the number of repeats of the STR regulates gene transcription. An inverse correlation between the number of repeats and the extent of transactivation was found in a haplotype consisting of three promoter SNPs (C-STR-T-T). We showed that these adjacent SNPs located outside the STR were required for the STR to function as eSTR. The C allele of rs35767 provides a binding site for CCAAT/enhancer-binding-protein δ (C/EBPD), which is essential for the gradational transactivation property of eSTR and FOXA3 may also be involved. Therefore, we propose a mechanism in which the gradational transactivation by the eSTR is caused by the interaction of one or more transcriptional complexes located outside the STR, rather than by direct binding to a repeat motif of the STR.
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Affiliation(s)
- Holly Y Chen
- Department of Chemical Pathology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
| | - Suk Ling Ma
- Department of Psychiatry, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
| | - Wei Huang
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Department of Pharmaceutics, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Lindan Ji
- Department of Biochemistry and Molecular Biology, Zhejiang Provincial Key Laboratory of Pathophysiology, Ningbo University School of Medicine, Ningbo, China
| | - Vincent H K Leung
- Department of Chemical Pathology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
| | - Honglin Jiang
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA
| | - Xiaoqiang Yao
- School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Nelson L S Tang
- Department of Chemical Pathology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.,School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China.,Laboratory of Genetics of Disease Susceptibility, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.,Functional Genomics and Biostatistical Computing laboratory, Shenzhen Research Institute, The Chinese University of Hong Kong, China.,KIZ/CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Kunming, China
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Kwasniewski W, Gozdzicka-Jozefiak A, Kotarska M, Polak G, Barczynski B, Broniarczyk J, Nowak W, Wolun-Cholewa M, Kwasniewska A, Kotarski J. Analysis of cytosine-adenine repeats in P1 promoter region of IGF-1 gene in peripheral blood cells and cervical tissue samples of females with cervical intraepithelial lesions and squamous cervical cancer. Mol Med Rep 2014; 11:766-74. [PMID: 25384883 PMCID: PMC4262512 DOI: 10.3892/mmr.2014.2916] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 09/12/2014] [Indexed: 01/18/2023] Open
Abstract
High oncogenic risk human papillomaviruses (HPVs) are closely associated with cancer of the cervix. However, HPV infection alone may not be sufficient to cause cervical cancer, and other factors or cofactors may have a cumulative effect on the risk of progression from cervical HPV infection to cancer. The present study investigates the cytosine-adenine (CA) repeat polymorphism in the P1 promoter region of the insulin-like growth factor-1 (IGF-1) gene among cervical precancerous and cancer patients and healthy control females. The association between these polymorphisms, tissue and blood serum levels of IGF-1, and cervical cancer risk and progression is evaluated. The material for analysis consisted of blood cells and postoperative tissues from patients diagnosed with low-grade squamous intraepithelial lesions (L-SILs), high-grade squamous intraepithelial lesions (H-SILs) and invasive cervical cancer (ICC). A polymerase chain reaction amplification and the sequencing of DNA were used for the identification of (CA)n repeats in the IGF-1 P1 region and detection of HPV DNA. The blood serum concentration of IGF was determined by enzyme-linked immunosorbent assay. The identification of the IGF-1 protein in the cervical tissues was performed by immunohistochemical analysis. The range of the length of the CA repeats in the study DNA was 11 to 21. However, the most common allele length and genotype in the control and study patients from serum and tissues was 19 CA repeats and a homozygous genotype of CA19/19. Statistically significant differences in the concentration of IGF-1 in the blood serum were observed between H-SILs and controls, only (p=0.047). However, the concentration of IGF-1 in the group of females with CA19/19, CA19<19 and CA19>19 was significantly higher in the group of patients with H-SIL (P=0.041) and ICC (P=0.048) in comparison with the control group. An association was detected between CA repeat length <19 and/or >19, IGF concentration in blood serum and tissues and the development of cervical cancer.
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Affiliation(s)
- Wojciech Kwasniewski
- Department of Gynecological Oncology and Gynecology, Medical University of Lublin, Lublin 20-081, Poland
| | | | - Maria Kotarska
- Rush Medical College, Rush Medical Center, Chicago, IL 606-12, USA
| | - Grzegorz Polak
- Department of Gynecological Oncology and Gynecology, Medical University of Lublin, Lublin 20-081, Poland
| | - Bartlomiej Barczynski
- Department of Gynecological Oncology and Gynecology, Medical University of Lublin, Lublin 20-081, Poland
| | - Justyna Broniarczyk
- Department of Molecular Virology, Adam Mickiewicz University, Poznan 61-614, Poland
| | - Witold Nowak
- Molecular Biology Techniques Laboratory, Adam Mickiewicz University, Poznan 61-614, Poland
| | - Maria Wolun-Cholewa
- Department of Cell Biology, Poznan University of Medical Sciences, Poznan 60-806, Poland
| | - Anna Kwasniewska
- Department of Obstetrics and Gynecology, Medical University of Lublin, Lublin 20-081, Poland
| | - Jan Kotarski
- Department of Gynecological Oncology and Gynecology, Medical University of Lublin, Lublin 20-081, Poland
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Wit JM, Ranke MB, Albertsson-Wikland K, Carrascosa A, Rosenfeld RG, Van Buuren S, Kristrom B, Schoenau E, Audi L, Hokken-Koelega ACS, Bang P, Jung H, Blum WF, Silverman LA, Cohen P, Cianfarani S, Deal C, Clayton PE, de Graaff L, Dahlgren J, Kleintjens J, Roelants M. Personalized approach to growth hormone treatment: clinical use of growth prediction models. Horm Res Paediatr 2014; 79:257-70. [PMID: 23735882 DOI: 10.1159/000351025] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Accepted: 04/02/2013] [Indexed: 11/19/2022] Open
Abstract
The goal of growth hormone (GH) treatment in a short child is to attain a fast catch-up growth toward the target height (TH) standard deviation score (SDS), followed by a maintenance phase, a proper pubertal height gain, and an adult height close to TH. The short-term response variable of GH treatment, first-year height velocity (HV) (cm/year or change in height SDS), can either be compared with GH response charts for diagnosis, age and gender, or with predicted HV based on prediction models. Three types of prediction models have been described: the Kabi International Growth Hormone Study models, the Gothenburg models and the Cologne model. With these models, 50-80% of the variance could be explained. When used prospectively, individualized dosing reduces the variation in growth response in comparison with a fixed dose per body weight. Insulin-like growth factor-I-based dose titration also led to a decrease in the variation. It is uncertain whether adding biochemical, genetic or proteomic markers may improve the accuracy of the prediction. Prediction models may lead to a more evidence-based approach to determine the GH dose regimen and may reduce the drug costs for GH treatment. There is a need for user-friendly software programs to make prediction models easily available in the clinic.
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Affiliation(s)
- J M Wit
- Department of Pediatrics, Leiden University Medical Center, NL-2300 Leiden, The Netherlands.
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Chen HY, Huang W, Leung VHK, Fung SLM, Ma SL, Jiang H, Tang NLS. Functional interaction between SNPs and microsatellite in the transcriptional regulation of insulin-like growth factor 1. Hum Mutat 2013; 34:1289-97. [PMID: 23757194 DOI: 10.1002/humu.22363] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Accepted: 05/28/2013] [Indexed: 11/11/2022]
Abstract
A CA-repeat microsatellite in insulin-like growth factor 1 (IGF1) promoter was associated with interindividual variation of circulating IGF1 level. Previously, we reported that such association was due to variation of haplotype unit in a linkage disequilibrium block composed of microsatellite and single-nucleotide polymorphisms (SNPs), suggesting the presence of an interaction between them. In this study, reporter assays were performed to investigate the regulatory effect and interaction of genetic variants on gene expression. We used an in vitro system to compare the transcriptional activities of haplotypes (rs35767:T>C, the CA-repeat microsatellite, rs5742612:T>C, and rs2288377:T>A) in evolutionarily conserved region of IGF1 promoter. In haplotype C-T-T, a longer microsatellite had a lower transcriptional activity (17.6 ± 2.4-fold for 17 repeats and 8.3 ± 1.1-fold for 21 repeats), whereas in haplotype T-C-A, such trend could not be observed, as the microsatellite with 21 repeats had the highest transcriptional activity (17.5 ± 2.3-fold). Because the microsatellite and SNPs affected the transcriptional activity of each other, there may be an interaction between them in the regulation of IGF1 expression. For the first time, we demonstrated that a noncoding microsatellite polymorphism could act as a functional unit and interact with SNPs in the regulation of transcription in human genome.
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Affiliation(s)
- Holly Y Chen
- Department of Chemical Pathology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
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Tsuchiya N, Narita S, Inoue T, Saito M, Numakura K, Huang M, Hatakeyama S, Satoh S, Saito S, Ohyama C, Arai Y, Ogawa O, Habuchi T. Insulin-like growth factor-1 genotypes and haplotypes influence the survival of prostate cancer patients with bone metastasis at initial diagnosis. BMC Cancer 2013; 13:150. [PMID: 23530598 PMCID: PMC3622563 DOI: 10.1186/1471-2407-13-150] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Accepted: 03/18/2013] [Indexed: 12/01/2022] Open
Abstract
Background The insulin-like growth factor-1 (IGF-1) plays an important role in growth of prostate cancer (PCa) cells and facilitating the development and progression of PCa. This study aimed to evaluate the association of polymorphisms in three linkage disequilibrium (LD) blocks of the IGF-1 on the survival of metastatic PCa patients. Methods A total of 215 patients with bone metastases at initial presentation were included in this study. The cytosine-adenine (CA) repeat polymorphism and rs12423791 were selected as representative polymorphisms in the LD blocks 1 and 2, respectively. Haplotype in the LD block 3 was analyzed using two tag single nucleotide polymorphisms (SNPs), rs6220 and rs7136446. Cancer-specific survival rate was estimated from the Kaplan-Meier curve, and the survival data were compared using the log-rank test. Results Cancer-specific survival was significantly associated with the CA repeat polymorphism, rs12423791, and rs6220 (P = 0.013, 0.014, and 0.014, respectively). Although rs7136446 had no significant association with survival, the haplotype in the LD block 3 was significantly associated with cancer-specific survival (P = 0.0003). When the sum of the risk genetic factors in each LD block (19-repeat allele, C allele of rs12423791, or C-T haplotype) was considered, patients with all the risk factors had significantly shorter cancer specific-survival than those with 0–2 risk factors (P = 0.0003). Conclusions Polymorphisms in the IGF-1, especially a haplotype in the LD block 3, are assumed to be genetic markers predicting the outcome of metastatic PCa.
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Affiliation(s)
- Norihiko Tsuchiya
- Department of Urology, Akita University Graduate School of Medicine, 1-1-1 Hondo, Akita 010-8543, Japan
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Sawaya SM, Lennon D, Buschiazzo E, Gemmell N, Minin VN. Measuring microsatellite conservation in mammalian evolution with a phylogenetic birth-death model. Genome Biol Evol 2012; 4:636-47. [PMID: 22593552 PMCID: PMC3516246 DOI: 10.1093/gbe/evs050] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Microsatellites make up ∼3% of the human genome, and there is increasing evidence that some microsatellites can have important functions and can be conserved by selection. To investigate this conservation, we performed a genome-wide analysis of human microsatellites and measured their conservation using a binary character birth--death model on a mammalian phylogeny. Using a maximum likelihood method to estimate birth and death rates for different types of microsatellites, we show that the rates at which microsatellites are gained and lost in mammals depend on their sequence composition, length, and position in the genome. Additionally, we use a mixture model to account for unequal death rates among microsatellites across the human genome. We use this model to assign a probability-based conservation score to each microsatellite. We found that microsatellites near the transcription start sites of genes are often highly conserved, and that distance from a microsatellite to the nearest transcription start site is a good predictor of the microsatellite conservation score. An analysis of gene ontology terms for genes that contain microsatellites near their transcription start site reveals that regulatory genes involved in growth and development are highly enriched with conserved microsatellites.
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Affiliation(s)
- Sterling M Sawaya
- Centre for Reproduction and Genomics, Department of Anatomy and Structural Biology, University of Otago, Dunedin, New Zealand
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Keku TO, Vidal A, Oliver S, Hoyo C, Hall IJ, Omofoye O, McDoom M, Worley K, Galanko J, Sandler RS, Millikan R. Genetic variants in IGF-I, IGF-II, IGFBP-3, and adiponectin genes and colon cancer risk in African Americans and Whites. Cancer Causes Control 2012; 23:1127-38. [PMID: 22565227 DOI: 10.1007/s10552-012-9981-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Accepted: 04/23/2012] [Indexed: 01/29/2023]
Abstract
PURPOSE Evaluating genetic susceptibility may clarify effects of known environmental factors and also identify individuals at high risk. We evaluated the association of four insulin-related pathway gene polymorphisms in insulin-like growth factor-1 (IGF-I) (CA)( n ) repeat, insulin-like growth factor-2 (IGF-II) (rs680), insulin-like growth factor-binding protein-3 (IGFBP-3) (rs2854744), and adiponectin (APM1 rs1501299) with colon cancer risk, as well as relationships with circulating IGF-I, IGF-II, IGFBP-3, and C-peptide in a population-based study. METHODS Participants were African Americans (231 cases and 306 controls) and Whites (297 cases, 530 controls). Consenting subjects provided blood specimens and lifestyle/diet information. Genotyping for all genes except IGF-I was performed by the 5'-exonuclease (Taqman) assay. The IGF-I (CA)(n) repeat was assayed by PCR and fragment analysis. Circulating proteins were measured by enzyme immunoassays. Odds ratios (ORs) and 95 % confidence intervals (CIs) were calculated by logistic regression. RESULTS The IGF-I (CA)( 19 ) repeat was higher in White controls (50 %) than African American controls (31 %). Whites homozygous for the IGF-I (CA)(19) repeat had a nearly twofold increase in risk of colon cancer (OR = 1.77; 95 % CI = 1.15-2.73), but not African Americans (OR = 0.73, 95 % CI 0.50-1.51). We observed an inverse association between the IGF-II Apa1 A-variant and colon cancer risk (OR = 0.49, 95 % CI 0.28-0.88) in Whites only. Carrying the IGFBP-3 variant alleles was associated with lower IGFBP-3 protein levels, a difference most pronounced in Whites (p-trend <0.05). CONCLUSIONS These results support an association between insulin pathway-related genes and elevated colon cancer risk in Whites but not in African Americans.
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Affiliation(s)
- Temitope O Keku
- Department of Medicine, Center for Gastrointestinal Biology and Disease, School of Medicine, University of North Carolina, Chapel Hill, 27599-7032, USA.
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