Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.1.1.7 (acetylcholinesterase)
28,390 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Lambert-Eaton myasthenic syndrome (LEMS) is an idiopathic or paraneoplastic syndrome producing antibodies against presynaptic voltage-gated P/Q calcium channels. This decreases calcium entry into the presynaptic terminal, which prevents binding of vesicles to the presynaptic membrane and acetylcholine release. LEMS is most often associated with small cell lung cancer, although idiopathic presentations comprise approximately 40% of the cases. The most common initial complaint is proximal muscle weakness involving the lower extremities more than the upper extremities. Depressed deep tendon reflexes and autonomic dysfunction are frequently present. Involvement of the bulbar or respiratory muscles is rare. Diagnosis is confirmed by electrophysiological testing, which demonstrates small compound muscle action potentials and facilitation with exercise or 20-Hz repetitive stimulation. A serum test for voltage-gated calcium channel antibodies is commercially available. Treatment involves removing the cancer associated with the disease. If cancer is not found, immunosuppressive medications and acetylcholinesterase inhibitors are used with moderate success. Patients with idiopathic LEMS should be screened every 6 months with chest imaging for cancer.
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PMID:Lambert-Eaton myasthenic syndrome. 1525 11

Daytime sedation is a common and potentially dose-limiting side effect of the opiate analgesics. The psychostimulants, such as methylphenidate, are frequently prescribed to treat this problem, but their use may be limited by side effects, such as weight loss, anxiety, or insomnia, or tolerance to their antisedative effects. Medications which enhance intracerebral cholinergic activity may offer an alternative treatment approach, since functional deficits of acetylcholine may, in part, account for the sedative and mind-dulling effects of opiates. Preliminary studies with donepezil, a centrally acting acetylcholinesterase (AChE) inhibitor approved for use in Alzheimer's disease, have suggested at least short-term benefit in treating opiate-related sedation. In a retrospective study, we reviewed the results of donepezil treatment in 40 patients, 37 of whom had cancer, which in most cases was in an advanced stage. All patients were receiving chronic opiate treatment, and the majority were on a stable opiate dose in the 2 weeks preceding the initiation of donepezil. The average opiate dose was 844 mg in oral morphine equivalents. Seventy-three percent of the patients experienced moderate or greater improvement on the Clinical Global Improvement Scale. Evaluations on the Epworth Sleepiness Scale (ESS; 0-24), visual analog sleepiness scale (VAS; 0-100), and average pain levels (0-100), before and after donepezil treatment, were obtained on 19 patients. Prior to donepezil, ESS, VAS, and pain scores were 18.5, 76.3, and 47.4. After an average of 21 days of donepezil treatment, scores were 9.5 (P < 0.001), 39.5 (P < 0.001), and 36.6 (P = 0.07), respectively. The mean total duration of treatment for patients was 54.4 days, with most patients stopping donepezil due to progression to a terminal state. Patients were generally started on 5 mg/ day, but 17 patients required higher doses to achieve or maintain efficacy, the average treatment dose being 9.13 mg/day. We concluded from this study that centrally acting AChE inhibitors are promising agents in the treatment of sedation,and perhaps of other neuropsychological side effects associated with the use of opiate analgesics.
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PMID:Treatment of opiate-related sedation: utility of the cholinesterase inhibitors. 1535 44

Although FDA-approved Alzheimer's disease (AD) treatment strategies (cholinesterase inhibitors and memantine) offer proven benefits, providers recognize unmet needs beyond what is currently available. Consequently there is a significant use of anecdotal yet unproven combinations for treating AD in practice. Based on the best evidence, combination drug therapy is the standard of care for treating other medical conditions such as malignancies, human immunodeficiency virus (HIV), and hypertension. We review recent combination drug therapy studies in AD. To date, the best evidence-based combination strategy is for moderate-to-severe AD, in which the addition of memantine to stable donepezil therapy was found to benefit cognition, behavior, and function. In milder stages of AD, the benefit of combination drug therapy has not been demonstrated. This review highlights the urgent need to systematically test additional rational drug combinations and the need for future trials to enroll adequate sample sizes and utilize relevant and sensitive outcome measures.
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PMID:Combination drug therapy for Alzheimer's disease: what is evidence-based, and what is not? 1594 60

Although the involvement of cholinesterases (ChEs) in the removal of acetylcholine (ACh) at cholinergic synapses is firmly established, there is evidence to suggest that acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) take part in several cellular processes. The early expression of ChE genes during embryonic development and their role in morphogenesis and apoptosis have been explained on the basis of the non-cholinergic actions of ChEs. In addition, the effects of AChE and BuChE, their inhibitors and antisense oligonucleotides in proliferating cellular systems, together with the mitogenic actions of ACh, support a role for ChEs in cell cycle control. The anomalous expression of ChEs may increase cell proliferation and contribute to cancer growth or development. The aim of this report is to compile the available information on ChEs in cancerous tissues in order to stimulating the research to clarify the molecular mechanisms by which ChEs may participate in cancer. Future investigations may throw light into this intriguing issue which will be of benefit to humankind.
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PMID:Expression of cholinesterases in brain and non-brain tumours. 1625 70

CPT-11 (irinotecan, 7-ethyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxycamptothecin) is an anticancer prodrug that has been approved for the treatment of colon cancer. It is a member of the camptothecin class of drugs and activation to the active metabolite SN-38, is mediated by carboxylesterases (CE). SN-38 is a potent topoisomerase I poison and is highly effective at killing human tumor cells, with IC50 values in the low nM range. However, upon high dose administration of CPT-11 to cancer patients, a cholinergic syndrome is observed, that can be rapidly ameliorated by atropine. This suggests a direct interaction of the drug or its metabolites with acetylcholinesterase (AChE). Kinetic studies indicated that CPT-11 was primarily responsible for AChE inhibition with the 4-piperidinopiperidine moiety, the major determinant in the loss of enzyme activity. Structural analogs of 4-piperidinopiperidine however, did not inhibit AChE, including a benzyl piperazine derivate of CPT-11. These results suggest that novel anticancer drugs could be synthesized that do not inhibit AChE, or alternatively, that novel AChE inhibitors could be designed based around the camptothecin scaffold.
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PMID:Inhibition of acetylcholinesterase by the anticancer prodrug CPT-11. 1625 98

The probable involvement of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) in cancer and the relevance of cholinergic responses for lung cancer growth prompted us to study whether cholinesterase activity of human lung is altered by malignancy. Surgical pieces of non-small lung carcinomas (NSLC) and their adjacent non-cancerous tissues (ANCT) were analysed for AChE and BChE activities. AChE activity in adenocarcinoma (AC) was 7.80 +/- 5.59 nmol of substrate hydrolysed per min and per mg of protein (mU/mg), the same as in their ANCT (8.83 +/- 4.72 mU/mg; P = 0.823); in large cell carcinoma (LCC), 7.52 +/- 3.32 mU/mg, approximately 50% less than in their ANCT (15.39 +/- 5.66 mU/mg; P = 0.043); and in squamous cell carcinoma (SCC), 1.39 +/- 0.58 mU/mg, 80% less than in ANCT (6.08 +/- 2.88 mU/mg; P = 0.003). BChE activity was 5.85 +/- 3.20 mU/mg in AC and 9.56 +/- 3.38 mU/mg in ANCT (P = 0.022); 2.94 +/- 2.01 mU/mg in LCC and 6.50 +/- 6.63 mU/mg in ANCT (P = 0.068); and 4.49 +/- 2.30 mU/mg in SCC and ANCT 6.56 +/- 4.09 mU/mg (P = 0.026). Abundant AChE dimers and fewer monomers were identified in lung and, although their distribution was unaffected by cancer, the binding with concanavalin A revealed changes in AChE glycosylation between SCC and their ANCT. The fall in BChE activity affected all molecules, with a strong decrease of the amphiphilic tetramers. Western blotting revealed protein bands with the expected mass of the principal AChE subunits, and the deeper intensity of the protein signal in SCC than in healthy lung, in lanes loaded with the same units of AChE activity, supported an augment in the amount of AChE protein/unit of AChE activity in SCC. The increased availability of acetylcholine in neoplastic lung, resulting from the fall of cholinesterase activity, may enhance cholinergic signalling and contribute to tumour progression.
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PMID:Cholinesterase activity of human lung tumours varies according to their histological classification. 1627 77

One hundred and twenty-six cancer patients admitted consecutively to the Istituto Nazionale Tumori, Milan, were examined. Within 48 h of hospital admission and again after one week, each patient underwent a nutritional assessment including standard anthropometric and biochemical indices (weight loss, serum proteins, serum albumin, total iron binding capacity (TIBC), cholinesterase (CHE) and lymphocyte count). Calorie and protein intake were also calculated. Each patient was classified with respect to a threshold of normality for each variable (< 10% for weight loss, > 6 g/dL for serum proteins, 3.4 g/dL for serum albumin, >/= 250 mmg/dL for TIBC, >/= 1900 mU/dL for CHE, >/= 1500/nm for total lymphocytes count and 90% Recommended Dietary Allowances (RDA) for nutritional intake). The Mann-Whitney test was performed to assess the statistical significance of the variation between all the nutritional variables at admission and after 7 days of hospitalisation. The relative risk of developing malnutrition regarding a nutritional index after 7 days of hospitalisation was then calculated with reference to each nutritional variable at admission. The significance was tested by the chi square test. The analysis showed that patients who developed deterioration of a nutritional index during hospitalisation had, at admission, worse values of the variable which subsequently deteriorated. In particular, low levels of serum albumin and total iron binding capacity were the variables associated with the higher number of nutritional indices which deteriorated after 7 days of hospitalisation. These were followed by low values of cholinesterase, body weight, serum proteins and lymphocytes. No significant relationship was found between change of a nutritional variable and protein and calorie intake. The risk of developing relevant weight loss (relative risk (RR) = 3.52), hypoalbuminemia (RR = 2.38) and hypoproteinemia (RR = 2.6) during hospitalisation was significantly higher when CHE was below 1900 mU/mL at admission.
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PMID:Predictability of deterioration in marginally malnourished cancer patients during hospitalisation. 1683 90

The purpose of this investigation was to evaluate in a randomised crossover study the effects on nutritional status of two isonitrogenous-isocaloric regimens of total parenteral nutrition (TPN) in 12 severely cachectic cancer patients. The regimens consisted of (1) G: 50 kcal of glucose.kg(-1).day(-1) + 2g amino-acids.kg(-1).day(-1) (2) GL: 30 kcal glucose and 20 kcal lipids.kg(-1) + 2g amino-acids.kg(-1).day(-1). Regimens G and GL were delivered sequentially for a period of 10 days each. Six patients (Group A) were randomised to receive regimen G first and regimen GL subsequently. In Group B patients the regimens alternated in the opposite way. The following nutritional variables were measured before TPN, after regimen G and after regimen GL: weight, arm circumference, arm muscle circumference, triceps skin fold, serum proteins, serum albumin, cholinesterase, transferrin, pre-albumin, retinol-binding protein, peripheral lymphocytes, cumulative nitrogen balance and mean urinary excretion of creatinine and 3-methylhistidine. The data showed that body weight and retinol-binding protein significantly increased with both G and GL regimens. No difference was found in the remaining variables, not even when comparing regimen G to GL. Increase in retinol-binding protein and in nitrogen balance were significantly better in the first period of treatment than in the second. These results show that the two regimens had a similar impact on the nutritional status of the cachectic cancer patients and choice between a glucose or a glucose-fat TPN should depend mainly on tolerance of the patients, duration and cost of therapy.
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PMID:Comparison of glucose vs. Glucose fat solutions in cancer patients: A controlled crossover study. 1683 80

Previous studies have shown that the cholinergic system plays a pivotal rule in small cell lung cancer (SCLC) cell growth through an autocrine loop that activates the nicotinic cholinergic receptor, which together with the activation of this receptor by nicotine links SCLC evolution with tobacco use. Non-small cell lung cancer (NSCLC) is the most common form of lung cancer and is also linked to tobacco use. Here we describe the presence of molecules of the cholinergic system in NSCLC samples and cell lines and investigate the implications of the cholinergic system in cell growth regulation. Cholino-acetyltransferase (ChAT), vesicular acetylcholine transporter (VAChT) and acetylcholinesterase (AChE) were observed in NSCLC tumor biopsies and in NSCLC cell lines. Polymeric alkylpyridinium salts (poly-APS) are AChE inhibitors isolated from the crude extract of the marine sponge, Reniera sarai. These metabolites were characterized as a mixture of two polymers of 3-octylpyridinium, including 29 and 99 monomeric units. Exposure of normal lung fibroblast and NSCLC cell lines to poly-APS revealed a selective cytotoxicity for cancer cells as compared to the normal fibroblast cell lines. FACS analysis indicated poly-APS induced apoptosis in NSCLC cells but not in normal lymphocytes. Non-toxic doses of poly-APS also potently reduced NSCLC cell-cell adhesion in suspension cultures. The limited toxicity of poly-APS on normal cells was confirmed by injection in the caudal vein of mice. No overt effects on health parameters, such as weight gain and physical behavior, were observed, and histological analysis of major organs did not reveal differences between the treated animals as compared to controls. These data demonstrate that NSCLC cells express cholinergic molecules that may be involved in cell growth regulation and that the cholinesterase inhibitor, poly-APS, shows selective toxicity toward NSCLC cells while having no apparent toxicity towards normal cells and tissue in vitro and in vivo.
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PMID:Marine sponge-derived polymeric alkylpyridinium salts as a novel tumor chemotherapeutic targeting the cholinergic system in lung tumors. 1708 75

Environmental substances seem to be involved in the etiology of breast cancers. Many studies have found an association between human cancer and exposure to agricultural pesticides such as the organophosphorous pesticides. Parathion is a cholinesterase inhibitor that induces the hydrolysis of body choline esters, including acetylcholine at cholinergic synapses. The primary target of action in insects is the nervous system whereby pesticides inhibit the release of the enzyme acetylcholinesterase at the synaptic junction. Atropine is a parasympatholytic alkaloid used as an antidote to acetylcholinesterase inhibitors. The aim of this study was to determine the effect of parathion and atropine on cell transformation of human breast epithelial cells in vitro. These studies showed that parathion alone was able to induce malignant transformation of an immortalized human breast epithelial cell line, MCF-10F as indicated by increased cell proliferation, anchorage independency and invasive capabilities. There was also an increase in c-kit, Trio, Rho-A, Rac-3, EGFR, Notch-4, Dvl-2, Ezrin, beta catenin and mutant p53 protein expression in the parathion-treated cells. However, atropine significantly inhibited this increase. In a human cell cycle array of 96 genes, 13 of them were altered by parathion treatment. Among the genes affected were the cyclins, such as cyclin D3, the cyclin-dependent kinases (CDKs) such as CDK41 and the minichromosome maintenance deficient (MCM) MCM2 and MCM3. It is suggested that parathion influences human breast epithelial cell transformation and is an initiator factor in the transformation process in breast cancer.
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PMID:Gene expression signature of parathion-transformed human breast epithelial cells. 1739 78


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