Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0376358 (prostate cancer)
 59,338 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An N-acetylation polymorphism is described that is expressed toward arylamine carcinogens in tumor target organs of an inbred rat model. High levels (rapid acetylator phenotype) of arylamine carcinogen N-acetyltransferase activity were observed in kidney, colon, prostate and urinary bladder cytosols derived from Fischer (F-344) inbred rats, the strain most commonly used for tumor bioassay studies and the strain most particularly used in arylamine-induced colon and prostate cancer studies. Significantly lower (slow acetylator phenotype) levels of arylamine carcinogen N-acetyltransferase activity were observed in corresponding tissue cytosols derived from Wistar-Kyoto inbred rats. Intermediate levels of arylamine carcinogen N-acetyltransferase activity significantly different from both the parental strains were observed in F1 hybrids of the parental strains, consistent with codominant expression of two alleles at a single gene locus. The arylamine substrates exhibiting the acetylator phenotype-dependent N-acetyltransferase activities included p-aminobenzoic acid, p-aminosalicylic acid, p-phenetidine, p-aminophenol, 2-aminofluorene, 3,2'-dimethyl-4-aminobiphenyl, beta-naphthylamine and 4-aminobiphenyl, but not procainamide. Highest levels of arylamine carcinogen N-acetyltransferase were expressed consistently in colon cytosol, but expression of the N-acetylation polymorphism toward arylamine carcinogens was observed in each (kidney, colon, prostate and urinary bladder) of the tumor target organs. The expression of the N-acetylation polymorphism in tumor target organs suggests that the inbred rat model will be useful in assessing the role of acetylator phenotype in arylamine-induced cancers of the colon and prostate.
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PMID:Extrahepatic expression of the N-acetylation polymorphism toward arylamine carcinogens in tumor target organs of an inbred rat model. 207 98

Hereditary peculiarities in individual responses to environmental chemicals are a common occurrence in human populations. Genetic variation in glutathione S-transferase, CYP1A2, N-acetyltransferase, and paraoxonase exemplify the relationship of metabolic variation to individual susceptibility to cancer and other toxicants of environmental origin. Heritable receptor protein variants, a subset of proteins of enormous pharmacogenetic potential that have not thus far been extensively explored from the pharmacogenetic standpoint, are also considered. Examples of interest that are considered include receptor variants associated with retinoic acid resistance in acute promyelocytic leukemia, with paradoxical responses to antiandrogens in prostate cancer, and with retinitis pigmentosa. Additional heritable protein variants of pharmacogenetic interest that result in antibiotic-induced deafness, glucocorticoid-remediable aldosteronism and hypertension, the long-QT syndrome, and beryllium-induced lung disease are also discussed. These traits demonstrate how knowledge of the molecular basis and mechanism of the variant response may contribute to its prevention in sensitive persons as well as to improved therapy for genetically conditioned disorders that arise from environmental chemicals.
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PMID:Influence of heredity on human sensitivity to environmental chemicals. 778 56

The role of two common polymorphisms of enzymes involved in the metabolism of drugs and carcinogens was studied in relation to prostate cancer. The gene encoding one of these enzymes (NAT2) is located in an area where frequent allelic loss occurs in prostate cancer. Mutations at the genes CYP2D6 and NAT2 were analysed by allele-specific polymerase chain reaction and restriction mapping in DNA from 94 subjects with prostate cancer and 160 male healthy control subjects. Eleven prostate specimens were analysed for genotype and enzymatic activities NAT2, CYP2D6 and CYP3A by using the enzyme-specific substrates sulphamethazine and dextromethorphan. Enzyme activities with substrate specificities corresponding to NAT2, CYP2D6 and CYP3A are present in human prostate tissue, with mean +/-s.d. activities of 4.8+/-4.4 pmol min(-1) mg(-1) protein, 156+/-91 and 112+/-72 nmol min(-1) mg(-1) protein respectively. The Km values for the prostate CYP2D6 and CYP3A enzyme activities corresponded to that of liver CYP2D6 and CYP3A activities, and the CYP2D6 enzyme activity is related to the CYP2D6 genotype. The N-acetyltransferase, in contrast, had a higher Km than NAT2 and was independent of the NAT2 genotype. The CYP2D6 and CYP3A enzymes, and an N-acetyltransferase activity that is independent of the regulation of the NAT2 gene, are expressed in human prostate tissue. The presence of carcinogen-metabolizing enzymes in human prostate with a high interindividual variability may be involved in the regulation of local levels of carcinogens and mutagens and may underlie interindividual differences in cancer susceptibility.
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PMID:Expression in human prostate of drug- and carcinogen-metabolizing enzymes: association with prostate cancer risk. 982 80

2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is a heterocyclic amine identified in the human diet and in cigarette smoke that produces prostate tumors in the rat. PhIP is bioactivated by cytochrome P-450 enzymes to N-hydroxylated metabolites that undergo further activation by conjugation enzymes, including the N-acetyltransferases, NAT1 and NAT2. To investigate the role of prostate-specific expression of human N-acetyltransferase 2 (NAT2) on PhIP-induced prostate cancer, we constructed a transgenic mouse model that targeted expression of human NAT2 to the prostate. Following construction, prostate, liver, lung, colon, small intestine, urinary bladder, and kidney cytosols were tested for human NAT1- and NAT2-specific N-acetyltransferase activities. Human NAT2-specific N-acetyltransferase activities were 15-fold higher in prostate of transgenic mice versus control mice, but were equivalent between transgenic mice and control mice in all other tissues tested. Human NAT1-specific N-acetyltransferase activities did not differ between transgenic and control mice in any tissue tested. Prostate cytosols from transgenic and control mice did not differ in their capacity to catalyze the N-acetylation of 2-aminofluorene, the O-acetylation of N-hydroxy-2-aminofluorene and N-hydroxy-PhIP or the N,O-acetylation of N-hydroxy-2-acetylaminofluorene. Transgenic and control mice administered PhIP did not differ in PhIP-DNA adduct levels in the prostate. This study is the first to report transgenic expression of human NAT2 in the mouse. The results do not support a critical role for bioactivation of heterocyclic amine carcinogens by human N-acetyltransferase-2 in the prostate. However, the lack of an effect may relate to the level of overexpression achieved and the presence of endogenous mouse acetyltransferases and/or sulfotransferases.
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PMID:Prostate-specific human N-acetyltransferase 2 (NAT2) expression in the mouse. 1038 74

The development of prostate cancer is dependent on heredity, androgenic influences, and exposure to environmental agents. A high intake of dietary fat is associated with an increased risk of prostate cancer, either through influence on steroid hormone profiles or through production of carcinogenic compounds that require biotransformation by enzymes. The polymorphic glutathione S-transferase (GST), N-acetyltransferase (NAT), and cytochrome P450 (CYP) enzymes are of particular interest in prostate cancer susceptibility because of their ability to metabolize both endogenous and exogenous compounds, including dietary constituents. Association between different NAT2, CYP2D6, CYP2C19 and GSTP1 genotypes and prostate cancer was studied in a Swedish and Danish case-control study comprising 850 individuals. The combined Swedish and Danish study population was analysed by polymerase chain reaction for the NAT2 alleles *4, *5A, *5B, *5C, *6 and *7, and for the CYP2D6 alleles *l, *3 and *4. The Swedish subjects were also analysed for the CYP2C19 alleles *1 and *2, and the GSTP1 alleles *A, *B and *C. No association was found between prostate cancer and polymorphisms in NAT2, CYP2D6, CYP2C19 or GSTP1. An association between CYP2D6 poor metabolism and prostate cancer was seen among smoking Danes; odds ratio 3.10 (95% confidence interval 1.07; 8.93), P = 0.03, but not among smoking Swedes; odds ratio 1.19 (95% confidence interval 0.41; 3.42), P = 0.75. Smoking is not a known risk factor for prostate cancer, and the association between CYP2D6 poor metabolism and prostate cancer in Danish smokers may have arisen by chance.
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PMID:Polymorphisms in NAT2, CYP2D6, CYP2C19 and GSTP1 and their association with prostate cancer. 1047 Oct 65

A review of findings is given which relate to the levels of circulating melatonin as well as the urinary excretion of its main peripheral metabolite 6-sulphatoxymelatonin (aMT6s) in patients with different types of cancer as well as in tumor-bearing animals. Clinical results show that circulating melatonin tends to be depressed in patients with primary tumors of different histological types including both endocrine-dependent (mammary, endometrial, prostate cancer) and endocrine-independent tumors (lung, gastric, colorectal cancer). Reduction of melatonin is most pronounced in patients with advanced localized primary tumors, such as mammary and prostate cancer where a clear negative correlation with tumor-size exists. The phenomenon of a reduction of circulating melatonin appears to be a transient one since patients with recidives show a normalization of melatonin. Surgical removal of the primary tumor does, however, not lead to normalization indicating that complex systemic changes appear to be involved in the down-regulation of melatonin. It is unclear at present, whether circulating melatonin is depleted in cancer patients due to a reduced production by the pineal gland or due to certain peripheral metabolic processes, although no evidence for an enhanced hepatic degradation to aMT6s, the main peripheral metabolite of melatonin, was found. The reduction of circulating melatonin is accompanied by neuroendocrine changes affecting the circadian secretion of the adenohypophyseal hormones prolactin, somatotropin and thyroid-stimulating hormone. In contrast to the above-described types of tumors many patients with ovarian cancer show highly elevated levels of melatonin perhaps due to the production of tissue-specific growth factors that could affect pineal melatonin secretion. Experiments with tumor-bearing animals clearly demonstrate that nocturnal circulating melatonin is modulated due to malignant growth. Detailed investigations with chemically induced mammary tumors in rats and serial transplants derived thereof show that slow-growing and well-differentiated tumors containing epithelial cell elements (adenocarcinomas and carcinosarcomas) lead to an enhanced production of melatonin involving activation of the rate-limiting enzyme of pineal melatonin biosynthesis (serotonin N-acetyltransferase) probably due to elevation of the sympathetic tone in response to a stimulation of the cellular immune system by malignant growth. As opposed to that nocturnal melatonin is depleted in animals with fast-growing mammary tumor transplants when myoepithelial-mesenchymal conversion leads to pure sarcomas. The reduction of melatonin appears to be due to either a reduced availability of the precursor amino acid tryptophan because of a glucocorticoid-induced activation of the hepatic enzyme tryptophan 2,3-dioxygenase or a direct peripheral degradation of melatonin via indoleamine 2,3-dioxygenase expressed in tumor and/or other tissues. The significance of these clinical and experimental findings relating to melatonin is discussed both in terms of their practical application as a possible tumor marker and from a theoretical point of view to understand better the mechanisms involved in complex host-tumor interactions involving the neuroimmunoendocrine network.
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PMID:Melatonin in cancer patients and in tumor-bearing animals. 1072 Oct 63

N-acetyltransferase-1 (NAT1) and N-acetyltransferase-2 (NAT2) are important in the metabolism of aromatic and heterocyclic amine carcinogens that induce prostate tumors in the rat. We investigated the association of genetic polymorphisms in NAT1 and NAT2, alone and in combination, with human prostate cancer. Incident prostate cancer cases and controls in a hospital-based case-control study were frequency-matched for age, race, and referral pattern. The frequency of slow acetylator NAT1 genotypes (NAT1*14, *15, *17) was 5.8% in controls but absent in cases. In contrast, in comparison with all other NAT1 genotypes the putative rapid acetylator NAT1 genotype (NAT1*10) was significantly higher in prostate cancer cases than controls (OR, 2.17; 95% CI, 1.08-4.33; P = 0.03). Combinations of NAT1*10 with NAT2 slow acetylator genotypes (OR, 5.08; 95% CI, 1.56-16.5; P = 0.008) or with NAT2 very slow (homozygous NAT2*5) acetylator genotypes (OR, 7.50; 95% CI, 1.55-15.4; P = 0.016) further increased prostate cancer risk. The results of this small pilot study suggest increased susceptibility to prostate cancer for subjects with combinations of NAT1*10 and slow (particularly very slow) NAT2 acetylator genotypes. This finding should be investigated further in larger cohorts and in other ethnic populations.
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PMID:Association of prostate cancer with rapid N-acetyltransferase 1 (NAT1*10) in combination with slow N-acetyltransferase 2 acetylator genotypes in a pilot case-control study. 1235 49

A number of studies report a high frequency of double primary cancers of the bladder and prostate. The coincidence was as high as 70% for prostate cancers in patients with bladder cancer, and 3.4% for bladder cancers in patients with prostate cancer. Two studies reviewing medical records reported a significant risk of bladder cancer after prostate cancer and of prostate cancer after bladder cancer. Only 1 of 3 cancer registry studies reported a significantly increased risk of prostate cancer after bladder cancer, and 3 of 11 studies reported a significantly increased risk in bladder cancer after prostate cancer. There was an association between DNA repair and N-acetyltransferase polymorphisms and risk of prostate and bladder cancer. These data suggest that these cancers may share a common carcinogenic process or that these patients are particularly susceptible to both cancers. Because of the association between these cancers, patients who are diagnosed with prostate or bladder cancer should be followed closely for the detection of the second urologic malignancy.
Clin Prostate Cancer 2004 Sep
PMID:Double primary cancers of the prostate and bladder: a literature review. 1547 90

Arylamine carcinogens and drugs are N-acetylated by cytosolic N-acetyltransferase (NAT), which uses acetyl-coenzyme A as a cofactor. NAT plays an initial role in the metabolism of these arylamine compounds. 2-Aminofluorene is one of the arylamine carcinogens which have been demonstrated to undergo N-acetylation in laboratory animals and humans. Our previous study showed that human cancer cell lines (colon cancer, colo 205; liver cancer, Hep G2; bladder cancer, T24; leukemia, HL-60; prostate cancer, LNCaP; osteogenic sarcoma, U-2 OS; malignant melanoma, A375.S2) displayed NAT activity, which was affected by aloe-emodin in human leukemia cells. The purpose of this study was to determine whether aloe-emodin could affect the enzyme activity and gene expression of NAT at the mRNA and protein levels in malignant human melanoma A375.S2 cells. The results showed that aloe-emodin inhibited NAT1 activity (decreased N-acetylation of 2-aminofluorene) in intact cells in a dose-dependent manner. The effect of aloe-emodin on NAT1 at the protein level was determined by Western blotting and the mRNA levels were examined by polymerase chain reaction (PCR) and cDNA microarray. These results clearly indicate that aloe-emodin inhibits the mRNA expression and enzyme activity of NAT1 in A375.S2 cells.
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PMID:Effect of inhibition of aloe-emodin on N-acetyltransferase activity and gene expression in human malignant melanoma cells (A375.S2). 1631 33

Associations between genotypes of phase 2 enzymes and cancer risk are extracted from epidemiological studies, namely case-control studies. Variant alleles in glutathione S-transferase (GST), UDP-glucuronosyltransferase (UGT), sulfotransferase (SULT), and N-acetyltransferase (NAT) have been used as molecular genetic biomarkers of risk. GSTM(my)1 has been associated with an increased risk of colorectal cancer, lung cancer, and bladder cancer and GSTP(pi)1 with prostate cancer. UGT1A1*28 and *37 are both associated with an increased risk of breast cancer as is SULT1A1*2. The presence of UGT1A1*28 results in an increased risk of ovarian cancer and NAT2 of colorectal and lung cancer. A high frequency of SULT1A1*1 has been identified in patients with breast cancer; the role in colorectal cancer is more controversial. This chapter discusses the balance between carcinogen activation and detoxification in relation to phase 2 enzymes.
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PMID:Cancer and molecular biomarkers of phase 2. 1639 74


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