Displaying publications 1 - 20 of 62 in total

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  1. Fulltext Predominance of G to A codon 12 mutation K-ras gene in Dukes' B colorectal cancer
    Zulhabri O, Rahman J, Ismail S, Isa MR, Wan Zurinah WN
    Singapore Med J, 2012 Jan;53(1):26-31.
    PMID: 22252179
    K-ras gene mutations in codons 12 and 13 are one of the earliest events in colon carcinogenesis.
    Matched MeSH terms: Colorectal Neoplasms/genetics*
  2. Fulltext Germline mutation analysis of MLH1 and MSH2 in Malaysian Lynch syndrome patients
    Zahary MN, Kaur G, Abu Hassan MR, Singh H, Naik VR, Ankathil R
    World J Gastroenterol, 2012 Feb 28;18(8):814-20.
    PMID: 22371642 DOI: 10.3748/wjg.v18.i8.814
    To investigate the protein expression profile of mismatch repair (MMR) genes in suspected cases of Lynch syndrome and to characterize the associated germline mutations.
    Matched MeSH terms: Colorectal Neoplasms/genetics*
  3. Mutations in mitochondrial NADH dehydrogenase subunit 1 (mtND1) gene in colorectal carcinoma
    Yusnita Y, Norsiah MD, Rahman AJ
    Malays J Pathol, 2010 Dec;32(2):103-10.
    PMID: 21329181 MyJurnal
    Mitochondrial Subunit ND1 (mtND1) gene is involved in the first step of the electron transport chain of oxidative phosphorylation (OXPHOS). Alteration of the electron transport components by mutations in mtDNA may compromise the normal electron flow. This could lead to an increase of bifurcation and generation of superoxidase radicals and increase oxidative stress in various types of cancer cells. Genomic DNA was extracted from thirty matched primary colorectal tumour tissues and matching non-tumour tissues. Blood samples were obtained from twenty-five normal people. The mtNDI coding region was amplified by step-down PCR. The purified products were then subjected to direct sequencing and subsequently, the DNA sequences obtained were compared with the revised Cambridge Reference Sequence (rCRS) and MITOMAP. From the analysis, the mtND1 gene showed 11 (45.8%) different mutations and also 13 (54.2%) polymorphisms. The heteroplasmic mutation A4123A/G (I273I/V) might have a pathogenic significance as it fulfills various pathogenic criteria. Three mutations, T3394C (Y30H), A3434G (Y43C) and C3497T (A64V) which occur in a highly conserved region were likely to alter the structure and function of the ND1 protein. We suggest that these mutations, and in combination with the polymorphic variance in mtDNA, may cause slight changes that generate subtly higher levels of toxic reactive oxygen species (ROS).
    Matched MeSH terms: Colorectal Neoplasms/genetics*
  4. Molecular alterations of Ras-Raf-mitogen-activated protein kinase and phosphatidylinositol 3-kinase-Akt signaling pathways in colorectal cancers from a tertiary hospital at Kuala Lumpur, Malaysia
    Yip WK, Choo CW, Leong VC, Leong PP, Jabar MF, Seow HF
    APMIS, 2013 Oct;121(10):954-66.
    PMID: 23992303 DOI: 10.1111/apm.12152
    Molecular alterations in KRAS, BRAF, PIK3CA, and PTEN have been implicated in designing targeted therapy for colorectal cancer (CRC). The present study aimed to determine the status of these molecular alterations in Malaysian CRCs as such data are not available in the literature. We investigated the mutations of KRAS, BRAF, and PTEN, the gene amplification of PIK3CA, and the protein expression of PTEN and phosphatidylinositol 3-kinase (PI3K) catalytic subunit (p110α) by direct DNA sequencing, quantitative real-time PCR, and immunohistochemistry, respectively, in 49 CRC samples. The frequency of KRAS (codons 12, 13, and 61), BRAF (V600E), and PTEN mutations, and PIK3CA amplification was 25.0% (11/44), 2.3% (1/43), 0.0% (0/43), and 76.7% (33/43), respectively. Immunohistochemical staining demonstrated loss of PTEN protein in 54.5% (24/44) of CRCs and no significant difference in PI3K p110α expression between CRCs and the adjacent normal colonic mucosa (p = 0.380). PIK3CA amplification was not associated with PI3K p110α expression level, but associated with male cases (100% of male cases vs 56% of female cases harbored amplified PIK3CA, p = 0.002). PI3K p110α expression was significantly higher (p = 0.041) in poorly/moderately differentiated carcinoma compared with well-differentiated carcinoma. KRAS mutation, PIK3CA amplification, PTEN loss, and PI3K p110α expression did not correlate with Akt phosphorylation or Ki-67 expression. KRAS mutation, PIK3CA amplification, and PTEN loss were not mutually exclusive. This is the first report on CRC in Malaysia showing comparable frequency of KRAS mutation and PTEN loss, lower BRAF mutation rate, higher PIK3CA amplification frequency, and rare PTEN mutation, as compared with published reports.
    Matched MeSH terms: Colorectal Neoplasms/genetics*
  5. Fulltext A case-controlled validation study of a blood-based seven-gene biomarker panel for colorectal cancer in Malaysia
    Yip KT, Das PK, Suria D, Lim CR, Ng GH, Liew CC
    J Exp Clin Cancer Res, 2010;29:128.
    PMID: 20846378 DOI: 10.1186/1756-9966-29-128
    BACKGROUND: Colorectal cancer (CRC) screening is key to CRC prevention and mortality reduction, but patient compliance with CRC screening is low. We previously reported a blood-based test for CRC that utilizes a seven-gene panel of biomarkers. The test is currently utilized clinically in North America for CRC risk stratification in the average-risk North American population in order to improve screening compliance and to enhance clinical decision making.
    METHODS: In this study, conducted in Malaysia, we evaluated the seven-gene biomarker panel validated in a North American population using blood samples collected from local patients. The panel employs quantitative RT-PCR (qRT-PCR) to analyze gene expression of the seven biomarkers (ANXA3, CLEC4D, TNFAIP6, LMNB1, PRRG4, VNN1 and IL2RB) that are differentially expressed in CRC patients as compared with controls. Blood samples from 210 patients (99 CRC and 111 controls) were collected, and total blood RNA was isolated and subjected to quantitative RT-PCR and data analysis.
    RESULTS: The logistic regression analysis of seven-gene panel has an area under the curve (AUC) of 0.76 (95% confidence interval: 0.70 to 0.82), 77% specificity, 61% sensitivity and 70% accuracy, comparable to the data obtained from the North American investigation of the same biomarker panel.
    CONCLUSIONS: Our results independently confirm the results of the study conducted in North America and demonstrate the ability of the seven biomarker panel to discriminate CRC from controls in blood samples drawn from a Malaysian population.
    Matched MeSH terms: Colorectal Neoplasms/genetics*
  6. Pilot study of the sensitivity and specificity of the DNA integrity assay for stool-based detection of colorectal cancer in Malaysian patients
    Yehya AH, Yusoff NM, Khalid IA, Mahsin H, Razali RA, Azlina F, et al.
    Asian Pac J Cancer Prev, 2012;13(5):1869-72.
    PMID: 22901138
    BACKGROUND: To assess the diagnostic potential of tumor-associated high molecular weight DNA in stool samples of 32 colorectal cancer (CRC) patients compared to 32 healthy Malaysian volunteers by means of polymerase chain reaction (PCR).

    METHODS: Stool DNA was isolated and tumor-associated high molecular weight DNA (1.476 kb fragment including exons 6-9 of the p53 gene) was amplified using PCR and visualized on ethidium bromide-stained agarose gels.

    RESULTS: Out of 32 CRC patients, 18 were positive for the presence of high molecular weight DNA as compared to none of the healthy individuals, resulting in an overall sensitivity of 56.3% with 100% specificity. Out of 32 patients, 23 had tumor on the left side and 9 on the right side, 16 and 2 being respectively positive. This showed that high molecular weight DNA was significantly (p=0.022) more detectable in patients with left side tumor (69.6% vs 22.2%). Out of 32 patients, 22 had tumors larger than 1.0 cm, 18 of these (81.8%) being positive for long DNA as compared to not a single patient with tumor size smaller than 1.0 cm (p<0.001).

    CONCLUSION: We detected CRC-related high molecular weight p53 DNA in stool samples of CRC patients with an overall sensitivity of 56.3% with 100% specificity, with a strong tumor size dependence.

    Matched MeSH terms: Colorectal Neoplasms/genetics
  7. Fulltext Somatic copy-neutral loss of heterozygosity and copy number abnormalities in Malaysian sporadic colorectal carcinoma patients
    Yam YY, Hoh BP, Othman NH, Hassan S, Yahya MM, Zakaria Z, et al.
    Genet. Mol. Res., 2013;12(1):319-27.
    PMID: 23420356 DOI: 10.4238/2013.February.7.1
    Colorectal cancer is one of the most common cancers in many countries, including Malaysia. The accumulation of genomic alterations is an important feature of colorectal carcinogenesis. A better understanding of the molecular events underlying the stages of colorectal carcinogenesis might be helpful in the detection and management of the disease. We used a commercially available single-nucleotide polymorphism genotyping array to detect both copy number abnormalities (CNAs) and copy-neutral loss of heterozygosity (LOH) in sporadic colorectal carcinomas. Matched tumor and normal tissues of 13 colorectal carcinomas (Dukes' stages A-D) were analyzed using a 250K single nucleotide polymorphism array. An additional assay was performed to determine the microsatellite instability status by using the National Cancer Institute-recommended BAT-26 panel. In general, copy number gain (92.3%) was most common, followed by copy number loss (53.8%) and copy-neutral LOH (46.2%). Frequent CNAs of gains and losses were observed on chromosomes 7p, 8, 13q, 17p, 18q, and 20q, and copy-neutral LOH was observed on chromosomes 2, 6, 12, 13q, 14q, 17, 20p, 19q, and 22q. Even though genomic alterations are associated with colorectal cancer progression, our results showed that DNA CNAs and copy-neutral LOH do not reflect disease progression in at least 50% tumors. Copy-neutral LOH was observed in both early and advanced tumors, which favors the involvement of these genomic alterations in the early stages of tumor development.
    Matched MeSH terms: Colorectal Neoplasms/genetics*
  8. Potential of dihydropyrimidine dehydrogenase genotypes in personalizing 5-fluorouracil therapy among colorectal cancer patients
    Teh LK, Hamzah S, Hashim H, Bannur Z, Zakaria ZA, Hasbullani Z, et al.
    Ther Drug Monit, 2013 Oct;35(5):624-30.
    PMID: 23942539 DOI: 10.1097/FTD.0b013e318290acd2
    Dihydropyrimidine dehydrogenase (DPD) is a pyrimidine catabolic enzyme involved in the initial and rate-limiting step of the catabolic pathway of toxic metabolites of 5-fluorouracil (5-FU). Several studies have reported that deficiency of DPD and polymorphisms of its gene are related to 5-FU toxicities and death. Association between serum concentration of 5-FU and its related toxicity has also been previously demonstrated. Hence, this study aims to understand the role of DPYD variants in serum level of 5-FU and the risk of developing toxicity to prevent adverse reactions and maximize therapy outcome for personalized medicine.
    Matched MeSH terms: Colorectal Neoplasms/genetics*
  9. Gender-specific association of NFKBIA promoter polymorphisms with the risk of sporadic colorectal cancer
    Tan SC, Suzairi MS, Aizat AA, Aminudin MM, Nurfatimah MS, Bhavaraju VM, et al.
    Med Oncol, 2013 Dec;30(4):693.
    PMID: 23996241 DOI: 10.1007/s12032-013-0693-6
    The inhibitory protein IκBα, encoded by the NFKBIA gene, plays an important role in regulating the activity of nuclear factor-kappa B, a transcription factor which has been implicated in the initiation and progression of cancers. This study aimed to evaluate the association of NFKBIA -826C>T (rs2233406) and -881A>G (rs3138053) polymorphisms with the risk of sporadic colorectal cancer (CRC) in Malaysian population. A case-control study comprising 474 subjects (237 CRC patients and 237 cancer-free controls) was carried out. The polymorphisms were genotyped from the genomic DNA of the study subjects employing PCR-RFLP, followed by DNA sequencing. The association between the polymorphic genotypes and CRC risk was evaluated by deriving odds ratios (ORs) and 95 % confidence intervals (CIs) using unconditional logistic regression analysis. The two polymorphisms were in complete and perfect linkage disequilibrium (D' = 1.0, r (2) = 1.0). Overall, no statistically significant CRC risk association was found for the polymorphisms (P > 0.05). A similar lack of association was observed when the data were stratified according to ethnicity (P > 0.05). However, stratification by gender revealed a significant inverse association between the heterozygous genotype of the polymorphisms and the risk of CRC among females (OR 0.53, 95 % CI 0.29-0.97, P = 0.04), but not among males (P > 0.05). In conclusion, the heterozygous genotype of the polymorphisms could contribute to a significantly decreased CRC risk among females, but not males, in the Malaysian population.
    Matched MeSH terms: Colorectal Neoplasms/genetics*
  10. Gene symbol: APC. Disease: colorectal cancer
    Tan LP, Ng BK, Balraj P, Poh BH, Lim PK, Peh SC
    Hum Genet, 2005 Dec;118(3-4):539-40.
    PMID: 16521263
    Matched MeSH terms: Colorectal Neoplasms/genetics*
  11. No difference in the occurrence of mismatch repair defects and APC and CTNNB1 genes mutation in a multi-racial colorectal carcinoma patient cohort
    Tan LP, Ng BK, Balraj P, Lim PK, Peh SC
    Pathology, 2007 Apr;39(2):228-34.
    PMID: 17454753
    BACKGROUND AND AIMS: Colorectal cancers of different subtypes involve different pathogenic pathways like the Wnt and the mutator pathways. In this study, we screened 73 colorectal cancer cases from a multi-racial group for genetic and expression profile defects with the aim of correlating these with patients' clinicopathological characteristics.
    METHODS: Mutation screening of the entire coding region of APC and exon 3 of CTNNB1, loss of heterozygosity (LOH) of APC, and microsatellite instability (MSI) status were assessed for 44 patients with available paired frozen normal and tumour tissues. In addition, 29 cases with available paraffin embedded tumour blocks were screened for mutation in exon 3 of CTNNB1, the APC mutation cluster region (codon 1286-1513), and hMLH1, hMSH2, hMSH6 protein expressions by immunohistochemistry method.
    RESULTS: In our study, 15/73 cases showed APC mutations (20.5%), 1/73 cases had CTNNB1 mutation (1.4%), 5/32 cases had APC LOH (15.6%), and 16/70 (22.9%) cases revealed at least some form of mismatch repair (MMR) defect. Tumour grade (poor differentiation) was found to correlate significantly with right-sided tumour and mucinous histology (p = 0.01879 and 0.00320, respectively). Patients of younger age (below 45 years) more often had tumours of mucinous histology (p = 0.00014), while patients of older age (above 75 years) more often had tumours on the right side of the colon (p = 0.02448). Tumours of the mucinous histology subtype often had MMR defects (p = 0.02686). There was no difference in the occurrence of APC and CTNNB1 mutations and MMR defects found within our multi-racial colorectal cancer patient cohort.
    CONCLUSION: Our findings support the notion that racial factor may not be related to the occurrence of MMR defects and APC and CTNNB1 mutations in our multi-racial patient cohort.
    Matched MeSH terms: Colorectal Neoplasms/genetics*
  12. Novel 2-Benzoyl-6-(2,3-Dimethoxybenzylidene)-Cyclohexenol Confers Selectivity toward Human MLH1 Defective Cancer Cells through Synthetic Lethality
    Song DSS, Leong SW, Ng KW, Abas F, Shaari K, Leong CO, et al.
    SLAS Discov, 2019 06;24(5):548-562.
    PMID: 30897027 DOI: 10.1177/2472555219831405
    DNA mismatch repair (MMR) deficiency has been associated with a higher risk of developing colorectal, endometrial, and ovarian cancer, and confers resistance in conventional chemotherapy. In addition to the lack of treatment options that work efficaciously on these MMR-deficient cancer patients, there is a great need to discover new drug leads for this purpose. In this study, we screened through a library of commercial and semisynthetic natural compounds to identify potential synthetic lethal drugs that may selectively target MLH1 mutants using MLH1 isogenic colorectal cancer cell lines and various cancer cell lines with known MLH1 status. We identified a novel diarylpentanoid analogue, 2-benzoyl-6-(2,3-dimethoxybenzylidene)-cyclohexenol, coded as AS13, that demonstrated selective toxicity toward MLH1-deficient cancer cells. Subsequent analysis suggested AS13 induced elevated levels of oxidative stress, resulting in DNA damage where only the proficient MLH1 cells were able to be repaired and hence escaping cellular death. While AS13 is modest in potency and selectivity, this discovery has the potential to lead to further drug development that may offer better treatment options for cancer patients with MLH1 deficiency.
    Matched MeSH terms: Colorectal Neoplasms/genetics
  13. Fulltext Mapping a Circular RNA-microRNA-mRNA-Signaling Regulatory Axis That Modulates Stemness Properties of Cancer Stem Cell Populations in Colorectal Cancer Spheroid Cells
    Rengganaten V, Huang CJ, Tsai PH, Wang ML, Yang YP, Lan YT, et al.
    Int J Mol Sci, 2020 Oct 23;21(21).
    PMID: 33114016 DOI: 10.3390/ijms21217864
    Spheroidal cancer cell cultures have been used to enrich cancer stem cells (CSC), which are thought to contribute to important clinical features of tumors. This study aimed to map the regulatory networks driven by circular RNAs (circRNAs) in CSC-enriched colorectal cancer (CRC) spheroid cells. The spheroid cells established from two CRC cell lines acquired stemness properties in pluripotency gene expression and multi-lineage differentiation capacity. Genome-wide sequencing identified 1503 and 636 circRNAs specific to the CRC parental and spheroid cells, respectively. In the CRC spheroids, algorithmic analyses unveiled a core network of mRNAs involved in modulating stemness-associated signaling pathways, driven by a circRNA-microRNA (miRNA)-mRNA axis. The two major circRNAs, hsa_circ_0066631 and hsa_circ_0082096, in this network were significantly up-regulated in expression levels in the spheroid cells. The two circRNAs were predicted to target and were experimentally shown to down-regulate miR-140-3p, miR-224, miR-382, miR-548c-3p and miR-579, confirming circRNA sponging of the targeted miRNAs. Furthermore, the affected miRNAs were demonstrated to inhibit degradation of six mRNA targets, viz. ACVR1C/ALK7, FZD3, IL6ST/GP130, SKIL/SNON, SMAD2 and WNT5, in the CRC spheroid cells. These mRNAs encode proteins that are reported to variously regulate the GP130/Stat, Activin/Nodal, TGF-β/SMAD or Wnt/β-catenin signaling pathways in controlling various aspects of CSC stemness. Using the CRC spheroid cell model, the novel circRNA-miRNA-mRNA axis mapped in this work forms the foundation for the elucidation of the molecular mechanisms of the complex cellular and biochemical processes that determine CSC stemness properties of cancer cells, and possibly for designing therapeutic strategies for CRC treatment by targeting CSC.
    Matched MeSH terms: Colorectal Neoplasms/genetics*
  14. Fulltext Role of genetic & environment risk factors in the aetiology of colorectal cancer in Malaysia
    Ramzi NH, Chahil JK, Lye SH, Munretnam K, Sahadevappa KI, Velapasamy S, et al.
    Indian J Med Res, 2014 Jun;139(6):873-82.
    PMID: 25109722
    Colorectal cancer (CRC) is second only to breast cancer as the leading cause of cancer-related deaths in Malaysia. In the Asia-Pacific area, it is the highest emerging gastrointestinal cancer. The aim of this study was to identify single nucleotide polymorphisms (SNPs) and environmental factors associated with CRC risk in Malaysia from a panel of cancer associated SNPs.
    Matched MeSH terms: Colorectal Neoplasms/genetics*
  15. Fulltext Diagnostic Accuracy of FOBT and Colorectal Cancer Genetic Testing: A Systematic Review & Meta-Analysis
    Ramdzan AR, Abd Rahim MA, Mohamad Zaki A, Zaidun Z, Mohammed Nawi A
    Ann Glob Health, 2019 05 15;85(1).
    PMID: 31099505 DOI: 10.5334/aogh.2466
    INTRODUCTION: Colorectal cancer (CRC) is the second leading cause of cancer related death in the world after lung cancer. Early detection of CRC leads to improvement in cancer survival rate. In recent years, efforts have been made to discover a non-invasive screening marker of higher sensitivity and specificity. Fecal occult blood testing (FOBT) and genetic testing become alternative modalities to screen CRC in the population other than colonoscopy. The aim of this systematic review and meta-analysis is to determine the diagnostic accuracy, sensitivity and specificity of FOBT and genetic testing as screening tools in colorectal cancer.

    METHODS: A literature search of PubMed, ScienceDirect, and Scopus was carried out. The search strategy was restricted to human subjects and studies are published in English. Data on sensitivity and specificity were extracted and pooled. Heterogeneity was assumed at significance level of p < 0.10 and was tested by chi squared. Degree of heterogeneity was quantified using the I2 statistic, and values of less than 25% is considered as homogenous. All analyses were performed using the software Meta-Disc.

    RESULTS: A total of eleven studies were suitable for data synthesis and analysis. Five studies were analyzed for the accuracy of genetic testing, the pooled estimate for sensitivity and specificity were 71% (95% CI: 66, 75%) and 95% (95% CI: 93, 97%) respectively. Another group of studies which had been evaluated for the accuracy of FOBT, the pooled sensitivity was 31% (95% CI: 25, 38%) while the pooled specificity was 87% (95% CI: 86, 89%).

    CONCLUSIONS: FOBTs is recommended to use as population-based screening tools for colorectal cancer while genetic testing should be focusing on patients with moderate and high risk individuals.

    Matched MeSH terms: Colorectal Neoplasms/genetics*
  16. Fulltext Physical activity and risks of breast and colorectal cancer: a Mendelian randomisation analysis
    Papadimitriou N, Dimou N, Tsilidis KK, Banbury B, Martin RM, Lewis SJ, et al.
    Nat Commun, 2020 01 30;11(1):597.
    PMID: 32001714 DOI: 10.1038/s41467-020-14389-8
    Physical activity has been associated with lower risks of breast and colorectal cancer in epidemiological studies; however, it is unknown if these associations are causal or confounded. In two-sample Mendelian randomisation analyses, using summary genetic data from the UK Biobank and GWA consortia, we found that a one standard deviation increment in average acceleration was associated with lower risks of breast cancer (odds ratio [OR]: 0.51, 95% confidence interval [CI]: 0.27 to 0.98, P-value = 0.04) and colorectal cancer (OR: 0.66, 95% CI: 0.48 to 0.90, P-value = 0.01). We found similar magnitude inverse associations for estrogen positive (ER+ve) breast cancer and for colon cancer. Our results support a potentially causal relationship between higher physical activity levels and lower risks of breast cancer and colorectal cancer. Based on these data, the promotion of physical activity is probably an effective strategy in the primary prevention of these commonly diagnosed cancers.
    Matched MeSH terms: Colorectal Neoplasms/genetics*
  17. Dietary cocoa protects against colitis-associated cancer by activating the Nrf2/Keap1 pathway
    Pandurangan AK, Saadatdoust Z, Esa NM, Hamzah H, Ismail A
    Biofactors, 2015 Jan-Feb;41(1):1-14.
    PMID: 25545372 DOI: 10.1002/biof.1195
    Colorectal cancer (CRC) is the third most common malignancy in males and the second most common cancer worldwide. Chronic colonic inflammation is a known risk factor for CRC. Cocoa contains many polyphenolic compounds that have beneficial effects in humans. The objective of this study is to explore the antioxidant properties of cocoa in the mouse model of azoxymethane (AOM)/dextran sulfate sodium (DSS)-induced colitis-associated cancer, focusing on the activation of Nrf2 signaling. Mice were treated with AOM/DSS and randomized to receive either a control diet or a 5 and 10% cocoa diet during the study period. On day 62 of the experiment, the entire colon was processed for biochemical and histopathological examination and further evaluations. Increased levels of malondialdehyde (MDA) were observed in AOM/DSS-induced mice; however, subsequent administration of cocoa decreased the MDA. Enzymatic and nonenzymatic antioxidants, such as superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase, were decreased in the AOM/DSS mice. Cocoa treatment increases the activities/levels of enzymatic and nonenzymatic antioxidants. Inflammatory mediators, such as inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2, were elevated during AOM/DSS-induction, and treatment with 5 and 10% cocoa effectively decreases the expression of iNOS and COX-2. The NF-E2-related factor 2 and its downstream targets, such as NQO1 and UDP-GT, were increased by cocoa treatment. The results of our study suggest that cocoa may merit further clinical investigation as a chemopreventive agent that helps prevent CAC.
    Matched MeSH terms: Colorectal Neoplasms/genetics
  18. Dietary non-nutritive factors in targeting of regulatory molecules in colorectal cancer: an update
    Pandurangan AK, Esa NM
    Asian Pac J Cancer Prev, 2013;14(10):5543-52.
    PMID: 24289544
    Colorectal cancer (CRC), a complex multi-step process involving progressive disruption of homeostatic mechanisms controlling intestinal epithelial proliferation/inflammation, differentiation, and programmed cell death, is the third most common malignant neoplasm worldwide. A number of promising targets such as inducible nitric acid (iNOS), cyclooxygenase (COX)-2, NF-E2-related factor 2 (Nrf2), Wnt/β-catenin, Notch and apoptotic signaling have been identified by researchers as useful targets to prevent or therapeutically inhibit colon cancer development. In this review article, we aimed to explore the current targets available to eliminate colon cancer with an update of dietary and non-nutritional compounds that could be of potential use for interaction with regulatory molecules to prevent CRC.
    Matched MeSH terms: Colorectal Neoplasms/genetics*
  19. Fulltext Genetic variation in the ADIPOQ gene, adiponectin concentrations and risk of colorectal cancer: a Mendelian Randomization analysis using data from three large cohort studies
    Nimptsch K, Song M, Aleksandrova K, Katsoulis M, Freisling H, Jenab M, et al.
    Eur J Epidemiol, 2017 May;32(5):419-430.
    PMID: 28550647 DOI: 10.1007/s10654-017-0262-y
    Higher levels of circulating adiponectin have been related to lower risk of colorectal cancer in several prospective cohort studies, but it remains unclear whether this association may be causal. We aimed to improve causal inference in a Mendelian Randomization meta-analysis using nested case-control studies of the European Prospective Investigation into Cancer and Nutrition (EPIC, 623 cases, 623 matched controls), the Health Professionals Follow-up Study (HPFS, 231 cases, 230 controls) and the Nurses' Health Study (NHS, 399 cases, 774 controls) with available data on pre-diagnostic adiponectin concentrations and selected single nucleotide polymorphisms in the ADIPOQ gene. We created an ADIPOQ allele score that explained approximately 3% of the interindividual variation in adiponectin concentrations. The ADIPOQ allele score was not associated with risk of colorectal cancer in logistic regression analyses (pooled OR per score-unit unit 0.97, 95% CI 0.91, 1.04). Genetically determined twofold higher adiponectin was not significantly associated with risk of colorectal cancer using the ADIPOQ allele score as instrumental variable (pooled OR 0.73, 95% CI 0.40, 1.34). In a summary instrumental variable analysis (based on previously published data) with higher statistical power, no association between genetically determined twofold higher adiponectin and risk of colorectal cancer was observed (0.99, 95% CI 0.93, 1.06 in women and 0.94, 95% CI 0.88, 1.01 in men). Thus, our study does not support a causal effect of circulating adiponectin on colorectal cancer risk. Due to the limited genetic determination of adiponectin, larger Mendelian Randomization studies are necessary to clarify whether adiponectin is causally related to lower risk of colorectal cancer.
    Matched MeSH terms: Colorectal Neoplasms/genetics*
  20. Fulltext Investigating meta-approaches for reconstructing gene networks in a mammalian cellular context
    Nazri A, Lio P
    PLoS One, 2012;7(1):e28713.
    PMID: 22253694 DOI: 10.1371/journal.pone.0028713
    The output of state-of-the-art reverse-engineering methods for biological networks is often based on the fitting of a mathematical model to the data. Typically, different datasets do not give single consistent network predictions but rather an ensemble of inconsistent networks inferred under the same reverse-engineering method that are only consistent with the specific experimentally measured data. Here, we focus on an alternative approach for combining the information contained within such an ensemble of inconsistent gene networks called meta-analysis, to make more accurate predictions and to estimate the reliability of these predictions. We review two existing meta-analysis approaches; the Fisher transformation combined coefficient test (FTCCT) and Fisher's inverse combined probability test (FICPT); and compare their performance with five well-known methods, ARACNe, Context Likelihood or Relatedness network (CLR), Maximum Relevance Minimum Redundancy (MRNET), Relevance Network (RN) and Bayesian Network (BN). We conducted in-depth numerical ensemble simulations and demonstrated for biological expression data that the meta-analysis approaches consistently outperformed the best gene regulatory network inference (GRNI) methods in the literature. Furthermore, the meta-analysis approaches have a low computational complexity. We conclude that the meta-analysis approaches are a powerful tool for integrating different datasets to give more accurate and reliable predictions for biological networks.
    Matched MeSH terms: Colorectal Neoplasms/genetics
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