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1.
Oncogene ; 41(39): 4446-4458, 2022 09.
Article in English | MEDLINE | ID: mdl-36008464

ABSTRACT

Colorectal cancer (CRC) is the second-most common malignant disease worldwide, and metastasis is the main culprit of CRC-related death. Metachronous metastases remain to be an unpredictable, unpreventable, and fatal complication, and tracing the molecular chain of events that lead to metastasis would provide mechanistically linked biomarkers for the maintenance of remission in CRC patients after curative treatment. We hypothesized, that Metastasis-associated in colorectal cancer-1 (MACC1) induces a secretory phenotype to enforce metastasis in a paracrine manner, and found, that the cell-free culture medium of MACC1-expressing CRC cells induces migration. Stable isotope labeling by amino acids in cell culture mass spectrometry (SILAC-MS) of the medium revealed, that S100A4 is significantly enriched in the MACC1-specific secretome. Remarkably, both biomarkers correlate in expression data of independent cohorts as well as within CRC tumor sections. Furthermore, combined elevated transcript levels of the metastasis genes MACC1 and S100A4 in primary tumors and in blood plasma robustly identifies CRC patients at high risk for poor metastasis-free (MFS) and overall survival (OS). Mechanistically, MACC1 strengthens the interaction of ß-catenin with TCF4, thus inducing S100A4 synthesis transcriptionally, resulting in elevated secretion to enforce cell motility and metastasis. In cell motility assays, S100A4 was indispensable for MACC1-induced migration, as shown via knock-out and pharmacological inhibition of S100A4. The direct transcriptional and functional relationship of MACC1 and S100A4 was probed by combined targeting with repositioned drugs. In fact, the MACC1-ß-catenin-S100A4 axis by statins (MACC1) and niclosamide (S100A4) synergized in inhibiting cancer cell motility in vitro and metastasis in vivo. The MACC1-ß-catenin-S100A4 signaling axis is causal for CRC metastasis. Selectively repositioned drugs synergize in restricting MACC1/S100A4-driven metastasis with cross-entity potential.


Subject(s)
Colonic Neoplasms , Colorectal Neoplasms , Hydroxymethylglutaryl-CoA Reductase Inhibitors , Rectal Neoplasms , Amino Acids/metabolism , Colonic Neoplasms/genetics , Colorectal Neoplasms/genetics , Gene Expression Regulation, Neoplastic , Humans , Niclosamide/pharmacology , Niclosamide/therapeutic use , Rectal Neoplasms/genetics , S100 Calcium-Binding Protein A4/genetics , S100 Calcium-Binding Protein A4/metabolism , Trans-Activators/genetics , beta Catenin/metabolism
2.
Lab Invest ; 100(10): 1288-1299, 2020 10.
Article in English | MEDLINE | ID: mdl-32601356

ABSTRACT

Histomorphology and immunohistochemistry are the most common ways of cancer classification in routine cancer diagnostics, but often reach their limits in determining the organ origin in metastasis. These cancers of unknown primary, which are mostly adenocarcinomas or squamous cell carcinomas, therefore require more sophisticated methodologies of classification. Here, we report a multiplex protein profiling-based approach for the classification of fresh frozen and formalin-fixed paraffin-embedded (FFPE) cancer tissue samples using the digital western blot technique DigiWest. A DigiWest-compatible FFPE extraction protocol was developed, and a total of 634 antibodies were tested in an initial set of 16 FFPE samples covering tumors from different origins. Of the 303 detected antibodies, 102 yielded significant correlation of signals in 25 pairs of fresh frozen and FFPE primary tumor samples, including head and neck squamous cell carcinomas (HNSC), lung squamous cell carcinomas (LUSC), lung adenocarcinomas (LUAD), colorectal adenocarcinomas (COAD), and pancreatic adenocarcinomas (PAAD). For this signature of 102 analytes (covering 88 total proteins and 14 phosphoproteins), a support vector machine (SVM) algorithm was developed. This allowed for the classification of the tissue of origin for all five tumor types studied here with high overall accuracies in both fresh frozen (90.4%) and FFPE (77.6%) samples. In addition, the SVM classifier reached an overall accuracy of 88% in an independent validation cohort of 25 FFPE tumor samples. Our results indicate that DigiWest-based protein profiling represents a valuable method for cancer classification, yielding conclusive and decisive data not only from fresh frozen specimens but also FFPE samples, thus making this approach attractive for routine clinical applications.


Subject(s)
Blotting, Western/methods , Neoplasms/classification , Protein Array Analysis/methods , Algorithms , Biomarkers, Tumor/metabolism , Blotting, Western/statistics & numerical data , Cryopreservation , Formaldehyde , Humans , Neoplasm Proteins/metabolism , Neoplasms/diagnosis , Neoplasms/metabolism , Organ Specificity , Paraffin Embedding , Protein Array Analysis/statistics & numerical data , Support Vector Machine , Tissue Fixation
3.
PLoS Genet ; 15(3): e1008076, 2019 03.
Article in English | MEDLINE | ID: mdl-30925167

ABSTRACT

Organoid cultures derived from colorectal cancer (CRC) samples are increasingly used as preclinical models for studying tumor biology and the effects of targeted therapies under conditions capturing in vitro the genetic make-up of heterogeneous and even individual neoplasms. While 3D cultures are initiated from surgical specimens comprising multiple cell populations, the impact of tumor heterogeneity on drug effects in organoid cultures has not been addressed systematically. Here we have used a cohort of well-characterized CRC organoids to study the influence of tumor heterogeneity on the activity of the KRAS/MAPK-signaling pathway and the consequences of treatment by inhibitors targeting EGFR and downstream effectors. MAPK signaling, analyzed by targeted proteomics, shows unexpected heterogeneity irrespective of RAS mutations and is associated with variable responses to EGFR inhibition. In addition, we obtained evidence for intratumoral heterogeneity in drug response among parallel "sibling" 3D cultures established from a single KRAS-mutant CRC. Our results imply that separate testing of drug effects in multiple subpopulations may help to elucidate molecular correlates of tumor heterogeneity and to improve therapy response prediction in patients.


Subject(s)
Cell Culture Techniques/methods , Colorectal Neoplasms/metabolism , Proto-Oncogene Proteins p21(ras)/metabolism , Cell Line, Tumor , Cohort Studies , Colorectal Neoplasms/physiopathology , Drug Resistance, Neoplasm/genetics , Female , Genes, erbB-1 , Humans , MAP Kinase Signaling System/genetics , MAP Kinase Signaling System/physiology , Male , Mutation , Organoids/metabolism , Organoids/physiology , Protein Kinase Inhibitors , Proto-Oncogene Proteins p21(ras)/genetics , Proto-Oncogene Proteins p21(ras)/physiology , Signal Transduction , ras Proteins/genetics
4.
J Mol Med (Berl) ; 97(6): 761-775, 2019 06.
Article in English | MEDLINE | ID: mdl-30891616

ABSTRACT

Abnormal scarring is a major challenge in modern medicine. The central role of myofibroblasts and TGF-ß signaling in scarring is widely accepted, but effective treatment options are missing. Autologous fat grafting is a novel approach that has led to significant improvements in the functionality and appearance of scar tissue. While the underlying mechanism is unknown, the potential role of paracrine effects of adipocytes has been discussed. Hence, with the aim of unraveling the regenerative potential of adipocytes, their effects on in vitro differentiated myofibroblasts and on fibroblasts from hypertrophic scars were investigated. Exposure to adipocyte-conditioned medium significantly decreased the expression of the myofibroblast marker α-SMA and ECM components, indicating the occurrence of myofibroblast reprogramming. Further analysis demonstrated that myofibroblast reprogramming was triggered by BMP-4 and activation of PPARγ signaling initiating tissue remodeling. These findings may pave the way for novel therapeutic strategies for the prevention or treatment of hypertrophic scars. KEY MESSAGES: Adipocytes induce distinct regenerative effects in hypertrophic scar tissue. Adipocytes secrete several proteins which are involved in wound healing and regeneration. Adipocytes secrete BMP-4 which activates myofibroblast reprogramming. Mediators secreted by adipocytes directly and indirectly activate PPARγ which exerts distinct anti-fibrotic effects. These findings may pave the way for novel therapeutic strategies for the prevention or treatment of hypertrophic scars.


Subject(s)
Adipocytes/cytology , Cellular Reprogramming , Cicatrix, Hypertrophic/pathology , Myofibroblasts/pathology , Regeneration , Actins/metabolism , Adipocytes/drug effects , Bone Morphogenetic Protein 4/pharmacology , Cell Differentiation/drug effects , Cellular Reprogramming/drug effects , Culture Media, Conditioned/pharmacology , Down-Regulation/drug effects , Humans , Male , Myofibroblasts/drug effects , PPAR gamma/metabolism , Regeneration/drug effects , Signal Transduction/drug effects , Stem Cells/cytology , Stem Cells/drug effects , Transforming Growth Factor beta/metabolism
5.
Nanoscale ; 7(6): 2777-83, 2015 Feb 14.
Article in English | MEDLINE | ID: mdl-25584968

ABSTRACT

We present a novel top-electrode spray-coating process for the solution-based deposition of silver nanowires (AgNWs) onto vacuum-processed small molecule organic electronic solar cells. The process is compatible with organic light emitting diodes (OLEDs) and organic light emitting thin film transistors (OLETs) as well. By modifying commonly synthesized AgNWs with a perfluorinated methacrylate, we are able to disperse these wires in a highly fluorinated solvent. This solvent does not dissolve most organic materials, enabling a top spray-coating process for sensitive small molecule and polymer-based devices. The optimized preparation of the novel AgNW dispersion and spray-coating at only 30 °C leads to high performance electrodes directly after the deposition, exhibiting a sheet resistance of 10.0 Ω â–¡(-1) at 87.4% transparency (80.0% with substrate). By spraying our novel AgNW dispersion in air onto the vacuum-processed organic p-i-n type solar cells, we obtain working solar cells with a power conversion efficiency (PCE) of 1.23%, compared to the air exposed reference devices employing thermally evaporated thin metal layers as the top-electrode.

6.
Adv Mater ; 25(29): 4006-13, 2013 Aug 07.
Article in English | MEDLINE | ID: mdl-23670954

ABSTRACT

High-efficiency white OLEDs fabricated on silver nanowire-based composite transparent electrodes show almost perfectly Lambertian emission and superior angular color stability, imparted by electrode light scattering. The OLED efficiencies are comparable to those fabricated using indium tin oxide. The transparent electrodes are fully solution-processable, thin-film compatible, and have a figure of merit suitable for large-area devices.


Subject(s)
Color , Lighting/instrumentation , Semiconductors , Energy Transfer , Equipment Design , Equipment Failure Analysis
7.
Front Oncol ; 1: 44, 2011.
Article in English | MEDLINE | ID: mdl-22649765

ABSTRACT

Sagopilone, a fully synthetic epothilone, is a microtubule-stabilizing agent optimized for high in vitro and in vivo activity against a broad range of tumor models, including those resistant to paclitaxel and other systemic treatments. Sagopilone development is accompanied by translational research studies to evaluate the molecular mode of action, to recognize mechanisms leading to resistance, to identify predictive response biomarkers, and to establish a rationale for combination with different therapies. Here, we profiled sagopilone activity in breast cancer cell lines. To analyze the mechanisms of mitotic arrest and apoptosis and to identify additional targets and biomarkers, an siRNA-based RNAi drug modifier screen interrogating 300 genes was performed in four cancer cell lines. Defects of the spindle assembly checkpoint (SAC) were identified to cause resistance against sagopilone-induced mitotic arrest and apoptosis. Potential biomarkers for resistance could therefore be functional defects like polymorphisms or mutations in the SAC, particularly in the central SAC kinase BUB1B. Moreover, chromosomal heterogeneity and polyploidy are also potential biomarkers of sagopilone resistance since they imply an increased tolerance for aberrant mitosis. RNAi screening further demonstrated that the sagopilone-induced mitotic arrest can be enhanced by concomitant inhibition of mitotic kinesins, thus suggesting a potential combination therapy of sagopilone with a KIF2C (MCAK) kinesin inhibitor. However, the combination of sagopilone and inhibition of the prophase kinesin KIF11 (EG5) is antagonistic, indicating that the kinesin inhibitor has to be highly specific to bring about the required therapeutic benefit.

8.
Dev Biol ; 334(2): 468-80, 2009 Oct 15.
Article in English | MEDLINE | ID: mdl-19682983

ABSTRACT

Salamanders have the remarkable ability to regenerate many body parts following catastrophic injuries, including a fully functional spinal cord following a tail amputation. The molecular basis for how this process is so exquisitely well-regulated, assuring a faithful replication of missing structures every time, remains poorly understood. Therefore a study of microRNA expression and function during regeneration in the axolotl, Ambystoma mexicanum, was undertaken. Using microarray-based profiling, it was found that 78 highly conserved microRNAs display significant changes in expression levels during the early stages of tail regeneration, as compared to mature tissue. The role of miR-196, which was highly upregulated in the early tail blastema and spinal cord, was then further analyzed. Inhibition of miR-196 expression in this context resulted in a defect in regeneration, yielding abnormally shortened tails with spinal cord defects in formation of the terminal vesicle. A more detailed characterization of this phenotype revealed downstream components of the miR-196 pathway to include key effectors/regulators of tissue patterning within the spinal cord, including BMP4 and Pax7. As such, our dataset establishes miR-196 as an essential regulator of tail regeneration, acting upstream of key BMP4 and Pax7-based patterning events within the spinal cord.


Subject(s)
Body Patterning/physiology , MicroRNAs/physiology , Regeneration/physiology , Spinal Cord/physiology , Tail/physiology , 3' Untranslated Regions , Ambystoma mexicanum/physiology , Amino Acid Sequence , Animals , Body Patterning/genetics , Bone Morphogenetic Protein 4/physiology , Cell Movement , Gene Expression Profiling , Gene Expression Regulation, Developmental , Genes, Homeobox , Hedgehog Proteins/antagonists & inhibitors , Hedgehog Proteins/immunology , Hedgehog Proteins/physiology , Molecular Sequence Data , PAX7 Transcription Factor/physiology , Peptide Fragments/chemistry , Peptide Fragments/immunology , Regeneration/genetics , Tail/injuries , Wound Healing/genetics , Wound Healing/physiology
9.
Nature ; 450(7172): 1096-9, 2007 Dec 13.
Article in English | MEDLINE | ID: mdl-18075594

ABSTRACT

All metazoan eukaryotes express microRNAs (miRNAs), roughly 22-nucleotide regulatory RNAs that can repress the expression of messenger RNAs bearing complementary sequences. Several DNA viruses also express miRNAs in infected cells, suggesting a role in viral replication and pathogenesis. Although specific viral miRNAs have been shown to autoregulate viral mRNAs or downregulate cellular mRNAs, the function of most viral miRNAs remains unknown. Here we report that the miR-K12-11 miRNA encoded by Kaposi's-sarcoma-associated herpes virus (KSHV) shows significant homology to cellular miR-155, including the entire miRNA 'seed' region. Using a range of assays, we show that expression of physiological levels of miR-K12-11 or miR-155 results in the downregulation of an extensive set of common mRNA targets, including genes with known roles in cell growth regulation. Our findings indicate that viral miR-K12-11 functions as an orthologue of cellular miR-155 and probably evolved to exploit a pre-existing gene regulatory pathway in B cells. Moreover, the known aetiological role of miR-155 in B-cell transformation suggests that miR-K12-11 may contribute to the induction of KSHV-positive B-cell tumours in infected patients.


Subject(s)
Gene Expression Regulation , Herpesvirus 8, Human/genetics , MicroRNAs/genetics , RNA, Viral/genetics , Sequence Homology, Nucleic Acid , 3' Untranslated Regions/genetics , 3' Untranslated Regions/metabolism , B-Lymphocytes/metabolism , B-Lymphocytes/pathology , Basic-Leucine Zipper Transcription Factors/genetics , Basic-Leucine Zipper Transcription Factors/metabolism , Cell Line , Cell Transformation, Viral/genetics , Fanconi Anemia Complementation Group Proteins/genetics , Fanconi Anemia Complementation Group Proteins/metabolism , Gene Expression Profiling , Humans , MicroRNAs/metabolism , Proto-Oncogene Proteins c-fos/genetics , Proto-Oncogene Proteins c-fos/metabolism , RNA, Viral/metabolism , Substrate Specificity
10.
Nat Methods ; 4(4): 337-44, 2007 Apr.
Article in English | MEDLINE | ID: mdl-17351622

ABSTRACT

RNA interference (RNAi) has become an important technique for loss-of-gene-function studies in mammalian cells. To achieve reliable results in an RNAi experiment, efficient and specific silencing triggers are required. Here we present genome-wide data sets for the production of endoribonuclease-prepared short interfering RNAs (esiRNAs) for human, mouse and rat. We used an algorithm to predict the optimal region for esiRNA synthesis for every protein-coding gene of these three species. We created a database, RiDDLE, for retrieval of target sequences and primer information. To test this in silico resource experimentally, we generated 16,242 esiRNAs that can be used for RNAi screening in human cells. Comparative analyses with chemically synthesized siRNAs demonstrated a high silencing efficacy of esiRNAs and a 12-fold reduction of downregulated off-target transcripts as detected by microarray analysis. Hence, the presented esiRNA libraries offer an efficient, cost-effective and specific alternative to presently available mammalian RNAi resources.


Subject(s)
Endoribonucleases/genetics , Genomic Library , Genomics/methods , RNA Interference , RNA, Small Interfering/genetics , Animals , Humans , Reverse Transcriptase Polymerase Chain Reaction , Sensitivity and Specificity , Transcription, Genetic , Transfection , Untranslated Regions , User-Computer Interface
11.
Methods Enzymol ; 392: 242-77, 2005.
Article in English | MEDLINE | ID: mdl-15644186

ABSTRACT

During the past five years, RNA interference (RNAi) has emerged as arguably the best functional genomics tool available to date, providing direct, causal links between individual genes and loss-of-function phenotypes through robust, broadly applicable, and readily upscalable methodologies. Originally applied experimentally in C. elegans and Drosophila, RNAi is now widely used in mammalian cell systems also. The development of commercially available libraries of short interfering RNAs (siRNAs) and other RNAi silencing reagents targeting entire classes of human genes provide the opportunity to carry out genome-scale screens to discover and characterize gene functions directly in human cells. A key challenge of these studies, also faced by earlier genomics or proteomics approaches, resides in reaching an optimal balance between the necessarily high throughput and the desire to achieve the same level of detailed analysis that is routine in conventional small-scale studies. This chapter discusses technical aspects of how to perform such screens, what parameters to monitor, and which readouts to apply. Examples of homogenous assays and multiplexed high-content microscopy-based screens are demonstrated.


Subject(s)
Genomics , RNA Interference , Apoptosis , Automation , Cell Division , Cell Line, Tumor , Genes, Reporter , Humans , RNA, Small Interfering/genetics
12.
Oncogene ; 23(51): 8384-91, 2004 Nov 01.
Article in English | MEDLINE | ID: mdl-15517020

ABSTRACT

High-throughput, human cell-based applications of RNA-mediated interference (RNAi) have emerged in recent years as perhaps the most powerful of a 'second wave' of functional genomics technologies. The available reagents and methodologies for RNAi screening studies now enable a wide range of different scopes and scales of investigation, from single-parameter assays applied to focused subsets of genes, to comprehensive genome-wide surveys based on rich, multiparameter readouts. As such, RNAi-based screens are offering important new avenues for the discovery and validation of novel therapeutic targets for several disease areas, including oncology. By enabling a 'clean' determination of gene function, that is the creation of direct causal links between gene and phenotype in human cells, RNAi investigations promise levels of pathophysiological relevance, efficiency, and range of applicability never before possible on this scale. The field of oncology, with its many assays using readily transfectable cell lines, has offered particularly fertile ground for showcasing the potential of RNAi-based genomics. However, like any other technology before it, RNAi is not without its own challenges, limitations, and caveats. Many of these issues stem directly from the choice of silencing reagent to be used in such studies, and the design of the overall screening strategy. Here, we discuss the basic design issues, potential advantages, and technical challenges of large-scale RNAi screens based on the use of chemically synthesized siRNA libraries.


Subject(s)
Gene Library , Genomics , Medical Oncology , RNA Interference/physiology , RNA, Small Interfering , Humans
13.
Int J Cancer ; 112(2): 259-64, 2004 Nov 01.
Article in English | MEDLINE | ID: mdl-15352038

ABSTRACT

Epidemiological evidence shows high red meat consumption to increase the risk of colorectal cancer, while the consumption of fruit and vegetables has been shown to be protective. Many genes have been identified that encode for enzymes involved in the metabolism of dietary carcinogens or anti-carcinogens. A study of 500 incident colorectal cancer cases and population controls, matched for age, sex and general practitioner, was conducted in the United Kingdom to investigate whether 6 such genes (CYP1A1, GSTT1, GSTM1, GSTP1, EPHX1 and NQO1) modify the relationship between diet and disease risk. Usual diet was estimated using a detailed questionnaire administered by interview. Fruit and vegetable consumption were both found to protect against colorectal cancer, while overall meat and red meat consumption were found to increase risk. There was some evidence of interaction between GSTT1 and vegetable consumption (p=0.006, not adjusted for multiple tests) but no evidence of interaction with GSTM1. The protective effect of vegetables was only seen in those with deficient or intermediate GSTT1 predicted phenotype [OR 0.3, 95% confidence interval (0.1, 0.6), and OR 0.6 (0.4, 0.96), OR 1.4 (0.3, 2.4) for those with fast phenotype], and a similar result was observed for cruciferous vegetables. There was also weak evidence of interaction between red meat intake and GSTT1 (p=0.06), GSTP1 (p=0.16, with p=0.02 after adjustment for potential confounders) and NQO1 predicted phenotype (p=0.01). Because of the multiple hypotheses tested in our study, these findings require independent confirmation.


Subject(s)
Colorectal Neoplasms/etiology , Colorectal Neoplasms/genetics , Diet , Fruit , Genetic Predisposition to Disease , Glutathione Transferase/genetics , Metabolism , Vegetables , Aged , Carcinogens/metabolism , Case-Control Studies , Female , Genotype , Glutathione Transferase/pharmacology , Humans , Male , Middle Aged , Phenotype , Risk Factors , United Kingdom
14.
Br J Clin Pharmacol ; 55(1): 68-76, 2003 Jan.
Article in English | MEDLINE | ID: mdl-12534642

ABSTRACT

AIMS: Several single nucleotide polymorphisms (SNPs) of the cytochrome P450 enzyme 1A2 gene (CYP1A2) have been reported. Here, frequencies, linkage disequilibrium and phenotypic consequences of six SNPs are described. METHODS: From genomic DNA, 114 British Caucasians (49 colorectal cancer cases and 65 controls) were genotyped for the CYP1A2 polymorphisms -3858G-->A (allele CYP1A2*1C), -2464T-->delT (CYP1A2*1D), -740T-->G (CYP1A2*1E and *1G), -164A-->C (CYP1A2*1F), 63C-->G (CYP1A2*2), and 1545T-->C (alleles CYP1A2*1B, *1G, *1H and *3), using polymerase chain reaction-restriction fragment length polymorphism assays. All patients and controls were phenotyped for CYP1A2 by h.p.l.c. analysis of urinary caffeine metabolites. RESULTS: In 114 samples, the most frequent CYP1A2 SNPs were 1545T-->C (38.2% of tested chromosomes), -164A-->C (CYP1A2*1F, 33.3%) and -2464T-->delT (CYP1A2*1D, 4.82%). The SNPs were in linkage disequilibrium: the most frequent constellations were found to be -3858G/-2464T/-740T/-164A/63C/1545T (61.8%), -3858G/-2464T/-740T/-164C/63C/1545C (33.3%), and -3858G/-2464delT/-740T/-164A/63C/1545C (3.51%), with no significant frequency differences between cases and controls. In the phenotype analysis, lower caffeine metabolic ratios were detected in cases than in controls. This was significant in smokers (n = 14, P = 0.020), and in a subgroup of 15 matched case-control pairs (P = 0.007), but it was not significant in nonsmokers (n = 100, P = 0.39). There was no detectable association between CYP1A2 genotype and caffeine phenotype. CONCLUSIONS: (i) CYP1A2 polymorphisms are in linkage disequilibrium. Therefore, only -164A-->C (CYP1A2*1F) and -2464T-->delT (CYP1A2*1D) need to be analysed in the routine assessment of CYP1A2 genotype; (ii) in vivo CYP1A2 activity is lower in colorectal cancer patients than in controls, and (iii) CYP1A2 genotype had no effect on phenotype (based on the caffeine metabolite ratio). However, this remains to be confirmed in a larger study.


Subject(s)
Caffeine/metabolism , Colorectal Neoplasms/genetics , Cytochrome P-450 CYP1A2/genetics , Aged , Aged, 80 and over , Colorectal Neoplasms/metabolism , Gene Frequency , Humans , Linkage Disequilibrium , Middle Aged , Phenotype , Polymerase Chain Reaction/methods , Polymorphism, Genetic
15.
Carcinogenesis ; 23(11): 1839-49, 2002 Nov.
Article in English | MEDLINE | ID: mdl-12419832

ABSTRACT

Susceptibility to colorectal cancer, one of the most common forms of cancer in the Western world, has been associated with several environmental and dietary risk factors. Dietary exposure to food derived heterocyclic amine carcinogens and polycyclic aromatic hydrocarbons have been proposed as specific risk factors. Many polymorphic Phase I and Phase II drug metabolizing enzymes are responsible for the metabolism and disposition of these compounds and it is therefore possible that inheritance of specific allelic variants of these enzymes may influence colorectal cancer susceptibility. In a multicenter case-control study, 490 colorectal cancer patients and 593 controls (433 matched case-control pairs) were genotyped for common polymorphisms in the cytochrome P450 (CYP1A1, CYP1A2, CYP1B1, CYP2A6, CYP2C9, CYP2C19 and CYP2D6), glutathione S-transferase (GSTM1, GSTP1 and GSTT1), sulfotransferase (SULT1A1 and SULT1A2), N-acetyl transferase 2 (NAT2), NAD(P)H:quinone oxidoreductase (NQO1), methylenetetrahydrofolate reductase (MTHFR), and microsomal epoxide hydrolase (EPHX1) genes. Matched case-control analysis identified alleles associated with higher colorectal cancer risk as carriage of CYP1A1*2C (OR = 2.15, 95% CI 1.36-3.39) and homozygosity for GSTM1*2/*2 (OR = 1.53, 95% CI 1.16-2.02). In contrast, inheritance of the CYP2A6*2 (OR = 0.51, 95% CI 0.28-1.06), CYP2C19*2 (OR = 0.72, 95% CI 0.52-0.98) and the EPHX1(His113) alleles were associated with reduced cancer risk. We found no association with colorectal cancer risk with NAT2 genotype or any of the other polymorphic genes associated with the metabolism and disposition of heterocyclic amine carcinogens. This data suggests that heterocyclic amines do not play an important role in the aetiology of colorectal cancer but that exposure to other carcinogens such as polycyclic aromatic hydrocarbons may be important determinants of cancer risk.


Subject(s)
Adenocarcinoma/chemically induced , Carcinogens/adverse effects , Cell Transformation, Neoplastic/chemically induced , Colorectal Neoplasms/chemically induced , Diet/adverse effects , Adenocarcinoma/enzymology , Adenocarcinoma/epidemiology , Adenocarcinoma/genetics , Aged , Aged, 80 and over , Alleles , Amines/adverse effects , Amines/pharmacokinetics , Arylamine N-Acetyltransferase/genetics , Arylamine N-Acetyltransferase/physiology , Biotransformation , Carcinogens/pharmacokinetics , Case-Control Studies , Cell Transformation, Neoplastic/genetics , Colorectal Neoplasms/enzymology , Colorectal Neoplasms/epidemiology , Colorectal Neoplasms/genetics , Cytochrome P-450 Enzyme System/genetics , Cytochrome P-450 Enzyme System/physiology , England , Epoxide Hydrolases/genetics , Epoxide Hydrolases/physiology , Female , Genetic Predisposition to Disease , Genotype , Glutathione Transferase/genetics , Glutathione Transferase/physiology , Heterocyclic Compounds/adverse effects , Heterocyclic Compounds/pharmacokinetics , Humans , Isoenzymes/genetics , Isoenzymes/physiology , Male , Methylenetetrahydrofolate Reductase (NADPH2) , Middle Aged , NAD(P)H Dehydrogenase (Quinone)/genetics , NAD(P)H Dehydrogenase (Quinone)/physiology , Oxidoreductases Acting on CH-NH Group Donors/genetics , Oxidoreductases Acting on CH-NH Group Donors/physiology , Polycyclic Aromatic Hydrocarbons/adverse effects , Polycyclic Aromatic Hydrocarbons/pharmacokinetics , Sulfotransferases/genetics , Sulfotransferases/physiology
16.
Clin Pharmacol Ther ; 72(4): 438-52, 2002 Oct.
Article in English | MEDLINE | ID: mdl-12386646

ABSTRACT

OBJECTIVES: The genetically polymorphic enzyme cytochrome P450 (CYP) 2D6 contributes to the biotransformation of the antipsychotic drug haloperidol. The impact of the polymorphism on haloperidol pharmacokinetics, adverse events, and efficacy was prospectively evaluated under naturalistic conditions in 172 unselected psychiatric inpatients with acute psychotic symptoms. METHODS: Serum trough levels of haloperidol and reduced haloperidol of patients receiving clinically adjusted doses were analyzed on days 3, 14, and 28 after hospital admission. Adverse events such as extrapyramidal symptoms were assessed by standardized rating scales. Efficacy was documented by recording the change in positive and negative schizophrenic symptoms. These parameters were correlated with the CYP2D6 genotype determined by polymerase chain reaction analysis for alleles *1 to *15 and *17. RESULTS: The serum concentrations showed wide interindividual variation. Reduced haloperidol trough levels and haloperidol total clearance correlated significantly with the number of active CYP2D6 genes. In addition, body weight and smoking had significant effects on haloperidol kinetics, whereas age, gender, and comedication showed only slight effects. The ratings for pseudoparkinsonism were significantly higher in poor metabolizers of substrates of CYP2D6. On the other hand, there was a trend toward lower therapeutic efficacy with increasing number of active CYP2D6 genes. CONCLUSIONS: Treatment with haloperidol should be avoided in extremely slow and extremely rapid metabolizers of CYP2D6 substrates. Both genotyping and blood concentration measurement explained only a fraction of the adverse events; about 20 patients would have to be genotyped to achieve a significant benefit in 1 patient. It is interesting that genotyping was at least as good a predictor of adverse events as the measured drug concentrations.


Subject(s)
Cytochrome P-450 CYP2D6/genetics , Haloperidol/pharmacokinetics , Polymorphism, Genetic/genetics , Adult , Cytochrome P-450 CYP2D6/metabolism , Dose-Response Relationship, Drug , Female , Genotype , Haloperidol/blood , Haloperidol/therapeutic use , Humans , Linear Models , Male , Multivariate Analysis , Prospective Studies , Schizophrenia/blood , Schizophrenia/drug therapy , Schizophrenia/genetics , Severity of Illness Index , Statistics, Nonparametric , Treatment Outcome
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