ABSTRACT
BACKGROUND: Total hip and knee arthroplasty (THA and TKA) are associated with significant blood loss and some patients require postoperative blood transfusion. While tranexamic acid has been studied extensively among this population, we tested the hypothesis that epsilon aminocaproic acid (EACA) can reduce blood loss and transfusion after joint arthroplasty. METHODS: In April 2014, our Veterans Affairs Medical Center introduced a protocol to administer EACA during THA and TKA. No antifibrinolytics were used previously. We retrospectively compared blood loss and incidence of transfusion among patients who underwent primary arthroplasty in the year before standardized administration of EACA with patients having the same procedures the following year. Blood loss was measured as delta hemoglobin (preoperative hemoglobin - hemoglobin on postoperative day 1). All patients undergoing primary THA or TKA were included. Patients having revision surgery were excluded. RESULTS: We identified 185 primary arthroplasty patients from the year before and 184 from the year after introducing the EACA protocol. There were no changes in surgical technique or attending surgeons during this period. Delta hemoglobin was significantly lower in the EACA group (2.7 ± 0.8 mg/dL) compared to the control group (3.4 ± 1.1 mg/dL) (P < .0001). The incidence of blood transfusion was also significantly lower in the EACA group (2.7%) compared to the control group (25.4%) (P < .0001). There was no difference in venous thromboembolic complications between groups. CONCLUSION: We demonstrated reductions in hemoglobin loss and transfusion following introduction of the EACA protocol in patients undergoing primary arthroplasty. EACA offers a lower cost alternative to TXA for reducing blood loss and transfusion in this population.
Subject(s)
Aminocaproic Acid/therapeutic use , Arthroplasty, Replacement, Hip , Arthroplasty, Replacement, Knee , Blood Loss, Surgical/prevention & control , Aged , Antifibrinolytic Agents/therapeutic use , Blood Transfusion , Body Mass Index , Female , Hemoglobins/analysis , Humans , Male , Middle Aged , Postoperative Hemorrhage/drug therapy , Postoperative Period , Retrospective Studies , Tranexamic Acid/therapeutic useABSTRACT
BACKGROUND: Current trends in pediatric cardiac surgery and anesthesiology include goal-directed allogeneic blood transfusion, but few studies address the transfusion of platelets and cryoprecipitate. We report a quality improvement initiative to reduce the transfusion of platelets and cryoprecipitate in infants having cardiac surgery with cardiopulmonary bypass (CPB). METHODS: Data from 50 consecutive patients weighing four to ten kilograms having cardiac surgery with CPB were prospectively collected after the institution of a policy to obtain each patient's platelet and fibrinogen levels during the rewarming phase of CPB. Data from 48 consecutive patients weighing four to ten kilograms having cardiac surgery with CPB prior to the implementation of the policy change were retrospectively collected. Demographics, laboratory values and blood product transfusion data were compared between the groups, using the Chi-square/Fisher's exact test or the T-Test/Wilcoxon Rank-Sum test, as appropriate. RESULTS: The results showed more total blood product exposures in the control group during the time from bypass through the first twenty-four post-operative hours (median of 2 units versus 1 unit in study group, p=0.012). During the time period from CPB separation through the first post-operative day, 67% of patients in the control group received cryoprecipitate compared to 32% in the study group (p=0.0006). There was no difference in platelet exposures between the groups. CONCLUSION: Checking laboratory results during the rewarming phase of CPB reduced cryoprecipitate transfusion by 50%. This reproducible strategy avoids empiric and potentially unnecessary transfusion in this vulnerable population.
Subject(s)
Blood Transfusion/methods , Cardiac Surgical Procedures , Cardiopulmonary Bypass , Blood Transfusion/economics , Cardiac Surgical Procedures/methods , Cardiopulmonary Bypass/methods , Cohort Studies , Factor VIII/therapeutic use , Fibrinogen/analysis , Fibrinogen/therapeutic use , Humans , Infant , Platelet Count , Platelet Transfusion/economics , Platelet Transfusion/methods , Retrospective StudiesABSTRACT
BACKGROUND: Current guidelines define severe aortic valve stenosis (AS) as an aortic valve area (AVA) ≤1.0 cm by the continuity equation and mean gradient (ΔPm) ≥ 40 mm Hg. However, these measurements can be discordant when classifying AS severity. Approximately one-third of patients with normal ejection fraction and severe AS by AVA have nonsevere AS by ΔPm when measured by preoperative transthoracic echocardiography (TTE). Given the use of positive pressure ventilation and general anesthesia in the pre-cardiopulmonary bypass (pre-CPB) period, we hypothesized that discordance between ΔPm and AVA during pre-CPB transesophageal echocardiography (TEE) would be higher than previously reported by TTE. METHODS: We retrospectively examined pre-CPB TEE data for patients who had aortic valve replacement, with or without coronary artery bypass grafting, from 2000 to 2012. Patients were excluded if they had ejection fraction <55%, emergency surgery, repeat sternotomy, moderate or severe mitral regurgitation, or severe aortic regurgitation. Only patients with both pre-CPB AVA and ΔPm measurements were included. Patients were grouped according to severity (mild, moderate, and severe) by AVA or ΔPm. Discordance was defined as disagreement between severities based on either parameter. RESULTS: A total of 277 patients met inclusion criteria. There were 227 patients with AVA ≤ 1.0 cm. The proportion of these patients with a ΔPm < 40 mm Hg was 54% (95% confidence interval, 47%-61%). The rate of discordance was significantly higher than the rate (37%; P < 0.001) found in previously reported analyses using TTE. Of the patients with a ΔPm ≥ 40 mm Hg, only 8% (n = 9/113) had a discordant AVA. In contrast, of the patients with ΔPm < 40 mm Hg, 80% (n = 131/164) had a discordant AVA. CONCLUSIONS: We confirmed our hypothesis that grading AS by ΔPm and AVA during pre-CPB TEE exhibits higher discordance than reported for TTE by others. It remains unclear whether these discrepancies reflect the effect of general anesthesia, imaging modality (TTE versus TEE) differences, inaccuracies in AS grading cutoffs when applied to pre-CPB TEE, or selection bias of the surgical population.
Subject(s)
Aortic Valve Stenosis/classification , Aortic Valve Stenosis/diagnostic imaging , Cardiopulmonary Bypass , Echocardiography, Transesophageal/classification , Echocardiography, Transesophageal/standards , Aged , Aged, 80 and over , Aortic Valve Stenosis/surgery , Female , Heart Valve Prosthesis Implantation/methods , Humans , Male , Middle Aged , Retrospective StudiesABSTRACT
BACKGROUND: Structured preoperative assessment has been reported to improve operating room efficiency as measured by metrics such as day of surgery cancellations (DOSCs). However, not all patients require comprehensive assessment; routine full assessments can result in unnecessary duplication of tests and investigations. Selective nurse screening under the supervision of anesthesiology may provide adequate information gathering in lower risk patients. This study is undertaken to assess if DOSC rates vary with different assessment processes. METHODS: At a single academic tertiary care hospital, from Jan 2 to May 31, 2013, the consecutive patients undergoing comprehensive preoperative assessment (CPA) and nurse screening (NS), as well as the patients not assessed by the anesthesiology-supervised preoperative process, were followed for the occurrence and reason for DOSC. The operating room schedule of all elective surgery patients was analyzed to allow calculation of rates of DOSCs. Reasons for cancellations were documented as one of ten structured reasons by preoperative holding area clerical staff. RESULTS: Overall, there were 14,893 elective surgery patients in this time period, with 183 DOSCs, giving a rate of 1.23 % (95 % CI 1.06, 1.42). Patients who received CPA numbered 5980; 29 of them had a DOSC, giving a rate of 0.48 % (95 % CI 0.33-0.70) (P < 0.0001 vs. no assessment). Patients receiving NS numbered 1840; 11 of them had a DOSC, giving a rate of 0.60 % (95 % CI 0.30-1.10) (P < 0.0001 vs. no assessment). The most common reason for cancellation was new medical condition. CONCLUSIONS: A very low DOSC rate can be achieved with a comprehensive preoperative process where some patients are selectively telephone screened by nurses, with complete assessment deferred to the anesthesiologist on the day of surgery.
ABSTRACT
Nonalcoholic fatty liver disease, a major cause of abnormal liver function, is often associated with obesity. Arginine (ARG) plays a role in modulating body weight/fat, but limited data exist as to the role of ARG in soy protein's ability to protect from liver steatosis. We investigated the role of native ARG in the soy protein isolate (SPI) in reducing liver steatosis in male obese Zucker rats. Rats (N=48; 6 weeks old) were randomly assigned to one of three diets for 8 or 16 weeks: the casein (CAS) diet as control (0.6% ARG), CAS diet supplemented to contain 1.3% ARG, or an SPI diet containing isoflavones (1.3% ARG). SPI and ARG rats gained significantly more weight (P<.05) than CAS rats after 16 weeks only. The SPI rats had lower liver steatosis scores after 8 and 16 weeks (P<.05 and P<.001, respectively) compared to CAS and ARG rats. SPI rats had lower serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels (P<.05) compared to CAS after 16 weeks, and AST was lower (P<.05) compared to ARG rats. After 16 weeks, the SPI rats had lower (P<.05) serum ALT and AST levels than at 8 weeks. Our results suggest that a longer period of SPI feeding results in lower liver steatosis and serum ALT and AST levels, while the ARG diet had no effect on steatosis or ALT and AST levels. We found that the SPI diet reduced (P<.001) serum tumor necrosis factor-α (TNF-α) compared to CAS and ARG diets after 8 and 16 weeks. The SPI diet significantly reduced (P<.001) interleukin-6 (IL-6) when compared to the CAS diet at 8 weeks, but there was no significant difference at 16 weeks. Based on the findings of our study, the protective effect of SPI in reducing liver steatosis is not modulated by its native arginine content.
Subject(s)
Arginine/therapeutic use , Caseins/therapeutic use , Diet , Dietary Supplements , Liver/drug effects , Non-alcoholic Fatty Liver Disease/prevention & control , Soybean Proteins/therapeutic use , Alanine Transaminase/blood , Animals , Arginine/pharmacology , Aspartate Aminotransferases/blood , Caseins/pharmacology , Interleukin-6/blood , Isoflavones/pharmacology , Isoflavones/therapeutic use , Liver/enzymology , Male , Non-alcoholic Fatty Liver Disease/blood , Non-alcoholic Fatty Liver Disease/etiology , Obesity/complications , Rats, Zucker , Soybean Proteins/chemistry , Soybean Proteins/pharmacology , Tumor Necrosis Factor-alpha/bloodABSTRACT
Anastrozole is an aromatase inhibitor (AI) used as adjuvant therapy for breast cancer. Anastrozole is subject to direct glucuronidation catalyzed by UDP-glucuronosyltransferase1A4 (UGT1A4). Interindividual variability in anastrozole glucuronidation may be affected by UGT1A4 SNPs. Interplay between drug metabolizing genes such as UGT1A4 and transporter genes may also be affected by genetic variability. Thus, we hypothesize that genetic variability in MRPs could influence anastrozole glucuronidation. The correlation between UGT1A4 and MRP2 or MRP3 transporter gene expressions and the correlation between MRP2 or MRP3 mRNA and anastrozole glucuronidation were analyzed in normal human liver samples. MRP2 and MRP3 mRNA levels were significantly correlated with UGT1A4 mRNA, with anastrozole glucuronidation and with each other (p<0.05). The data also demonstrated that MRP2 SNPs are positively correlated with MRP2 mRNA expression, while there was no association between MRP3 SNPs from this study and MRP3 expression. Significant correlations (p<0.05) between certain MRP2 SNPs (3972C>T, 2366C>T and -24C>T) and anastrozole glucuronidation were observed. There were no observed correlations between MRP3 SNPs and anastrozole glucuronidation. MRP2 polymorphisms have been identified as playing a role in the disposition of other drugs, and the data presented here indicate for the first time that MRP2 SNPs could influence anastrozole metabolism and contribute to interindividual variation in treatment responses.
ABSTRACT
Tamoxifen (Tam) is a selective estrogen receptor modulator used to inhibit breast tumor growth. Tam can be directly N-glucuronidated via the tertiary amine group or O-glucuronidated after cytochrome P450-mediated hydroxylation. In this study, the glucuronidation of Tam and its hydroxylated and/or chlorinated derivatives [4-hydroxytamoxifen (4OHTam), toremifene (Tor), and 4-hydroxytoremifene (4OHTor)] was examined using recombinant human UDP-glucuronosyltransferases (UGTs) from the 1A subfamily and human hepatic microsomes. Recombinant UGT1A4 catalyzed the formation of N-glucuronides of Tam and its derivatives and was the most active UGT enzyme toward these compounds. Therefore, it was hypothesized that single nucleotide polymorphisms (SNPs) in the promoter region of UGT1A4 have the ability to significantly decrease the glucuronidation rates of Tam metabolites in the human liver. In vitro activity of 64 genotyped human liver microsomes was used to determine the association between the UGT1A4 promoter and coding region SNPs and the glucuronidation rates of Tam, 4OHTam, Tor, and 4OHTor. Significant decreases in enzymatic activity were observed in microsomes for individuals heterozygous for -163G/A and -217T/G. These alterations in glucuronidation may lead to prolonged circulating half-lives and may potentially modify the effectiveness of these drugs in the treatment of breast cancer.
Subject(s)
Glucuronosyltransferase/genetics , Polymorphism, Single Nucleotide/genetics , Promoter Regions, Genetic/genetics , Tamoxifen/metabolism , Genotype , Humans , Hydroxylation/genetics , Microsomes, Liver/metabolism , Pharmacogenetics/methods , Tamoxifen/analogs & derivatives , Toremifene/metabolismABSTRACT
BACKGROUND: Sulfotransferase 1A1 (SULT1A1) gene expression is tissue specific, with little to no expression in normal breast epithelia. Expression in breast tumors has been documented, but the transcriptional regulation of SULT1A1 in human breast tissue is poorly understood. We identified Nuclear Factor I (NFI) as a transcription factor family involved in the regulation of SULT1A1 expression. METHODS: Transcription Factor Activation Profiling Plate Array assay was used to identify the possible transcription factors that regulate the gene expression of SULT1A1in normal breast MCF-10A cells and breast cancer ZR-75-1 cells. Expression levels of NFI-C and SULT1A1 were determined by real-time RT-PCR using total RNA isolated from 84 human liver samples. Expression levels of SULT1A1, NFI-A, NFI-B, NFI-C, and NFI-X were also determined in different human breast cancer cell lines (MCF-7, T-47D, ZR-75-1, and MDA-MB-231), in the transformed human epithelial cell line MCF-10A, and in ZR-75-1 cells that were transfected with siRNAs directed against NFI-A, NFI-B, NFI-C, or NFI-X for 48 h. The copy numbers of SULT1A1 in cell lines ZR-75-1, MCF-7, T-47D, MDA-MB-231, and MCF-10A were determined using a pre-designed Custom Plus TaqMan® Copy Number kit from Life Technologies. RESULTS: In normal human liver samples, SULT1A1 mRNA level was positively associated with NFI-C. In different human breast cancer and normal epithelial cell lines, SULT1A1 expression was positively correlated with NFI-B and NFI-C. SULT1A1 expression was decreased 41% and 61% in ZR-75-1 cells treated with siRNAs against NFI-A and NFI-C respectively. SULT1A1 gene expression was higher in cells containing more than one SULT1A1 copy numbers. CONCLUSIONS: Our data suggests that SULT1A1 expression is regulated by NFI, as well as SULT1A1 copy number variation in human breast cancer cell lines. These data provide a mechanistic basis for the differential expression of SULT1A1 in different tissues and different physiological states of disease.
ABSTRACT
OBJECTIVES: Accumulating evidence suggests that energy imbalance plays a role in pancreatic carcinogenesis. However, it remains unclear whether single-nucleotide polymorphisms (SNPs) in genes regulating energy homeostasis influence pancreatic cancer risk. We investigated this question in a case-control study conducted from 1994 to 1998. METHODS: Patients (n = 173) were ascertained from hospitals in the Twin Cities and Mayo Clinic, Minnesota. Control subjects (n = 476) were identified from the general population and frequency matched to patients by age and sex. Seven SNPs were evaluated in relation to pancreatic cancer using unconditional logistic regression. RESULTS: After adjustment for confounders, the leucine/proline or proline/proline genotype of the neuropeptide Y (NPY) gene rs16139 was associated with a lower risk than the leucine/leucine genotype (odds ratio, 0.40 [95% confidence interval, 0.15-0.91]). Conversely, an increased risk was observed for the glycine/arginine or arginine/arginine genotype of the adrenoceptor ß2, surface (ADRB2) gene rs1042713 as compared with the glycine/glycine genotype (odds ratio, 1.52 [95% confidence interval, 1.01-2.31]). CONCLUSIONS: This study first reveals that SNPs in genes modulating energy intake (NPY) and energy expenditure (ADRB2) altered pancreatic cancer risk. If confirmed by other studies, our findings may shed new light on the etiology and prevention of pancreatic cancer.
Subject(s)
Energy Metabolism/genetics , Genetic Predisposition to Disease/genetics , Pancreatic Neoplasms/genetics , Polymorphism, Single Nucleotide , Aged , Case-Control Studies , Female , Gene Frequency , Genotype , Ghrelin/genetics , Humans , Ion Channels/genetics , Leptin/genetics , Logistic Models , Male , Middle Aged , Minnesota , Mitochondrial Proteins/genetics , Neuropeptide Y/genetics , Receptors, Adrenergic, beta-2/genetics , Receptors, Adrenergic, beta-3/genetics , Receptors, Leptin/genetics , Risk Factors , Uncoupling Protein 3ABSTRACT
Fulvestrant (Faslodex™) is a pure antiestrogen that is effective in treating estrogen receptor-(ER) positive breast cancer tumors that are resistant to selective estrogen receptor modulators such as tamoxifen. Clinical trials investigating the utility of adding fulvestrant to other therapeutics have not been shown to affect cytochrome P450-mediated metabolism. Effects on phase II metabolism and drug resistance have not been explored. This study demonstrates that fulvestrant up regulates the expression of UDP glucuronosyltransferase 1A4 (UGT1A4) >2.5- and >3.5-fold in MCF7 and HepG2 cells, respectively. Up regulation occurred in a time- and concentration-dependent manner, and was inhibited by siRNA silencing of ERα. Fulvestrant also up regulates multidrug resistance-associated proteins (MRPs). There was an up regulation of MRP2 (1.5- and 3.5-fold), and MRP3 (5.5- and 4.5-fold) in MCF7 and HepG2 cell lines, respectively, and an up regulation of MRP1 (4-fold) in MCF7 cells. UGT1A4 mRNA up regulation was significantly correlated with UGT1A4 protein expression, anastrozole glucuronidation, ERα mRNA expression and MRP mRNA expression, but not with ERα protein expression. Genetic variants in the UGT1A4 promoter (-163A, -217G and -219T) reduced the basal activity of UGT1A4 by 40-60%. In silico analysis indicated that transcription factor c-Myb binding capacity may be affected by these variations. Luciferase activity assays demonstrate that silencing c-Myb abolished UGT1A4 up regulation by fulvestrant in promoters with the common genotype (-163G, -217 T and -219C) in MCF7 cells. These data indicate that fulvestrant can influence the disposition of other UGT1A4 substrates. These findings suggest a clinically significant role for UGT1A4 and MRPs in drug efficacy.
ABSTRACT
Anastrozole belongs to the nonsteroidal triazole-derivative group of aromatase inhibitors. Recently, clinical trials demonstrated improved antitumoral efficacy and a favorable toxicity with third-generation aromatase inhibitors, compared with tamoxifen. Anastrozole is predominantly metabolized by phase I oxidation with the potential for further phase II glucuronidation. It also, however, is subject to direct N-glucuronidation by UDP-glucuronosyltransferase 1A4 (UGT1A4). Anastrozole pharmacokinetics vary widely among patients, but pharmacogenomic studies of patients treated with anastrozole are sparse. In this study, we examined individual variability in the glucuronidation of anastrozole and its association with UGT1A4 promoter and coding region polymorphisms. In vitro assays using liver microsomal preparations from individual subjects (n = 96) demonstrated 235-fold variability in anastrozole glucuronidation. Anastrozole glucuronidation was correlated (r = 0.99; P < 0.0001) with lamotrigine glucuronidation (a diagnostic substrate for UGT1A4) and with UGT1A4 mRNA expression levels in human liver microsomes (r = 0.99; P < 0.0001). Recombinant UGT1A4 catalyzed anastrozole glucuronidation, which was inhibited by hecogenin (IC50 = 15 µM), a UGT1A4 specific inhibitor. The promoter region of UGT1A4 is polymorphic, and compared with those homozygous for the common allele, lower enzymatic activity was observed in microsomes from individuals heterozygous for -163G
Subject(s)
Aromatase Inhibitors/pharmacokinetics
, Gene Expression Regulation, Enzymologic/genetics
, Glucuronosyltransferase/genetics
, Inactivation, Metabolic/genetics
, Nitriles/pharmacokinetics
, Polymorphism, Single Nucleotide/genetics
, Triazoles/pharmacokinetics
, Anastrozole
, Anticonvulsants/pharmacokinetics
, Genotype
, Glucuronosyltransferase/antagonists & inhibitors
, Glucuronosyltransferase/biosynthesis
, Humans
, In Vitro Techniques
, Lamotrigine
, Microsomes, Liver/metabolism
, Sapogenins/pharmacology
, Triazines/pharmacokinetics
ABSTRACT
Toremifene (TOR) is a selective estrogen receptor modulator used in adjuvant therapy for breast cancer and in clinical trials for prostate cancer prevention. The chemical structure of TOR differs from that of tamoxifen (TAM) by the presence of a chlorine atom in the ethyl side chain, resulting in a more favorable toxicity spectrum with TOR. In addition, some patients who fail on TAM therapy benefit from high-dose TOR therapy. Several studies have indicated that functional genetic variants in the TAM metabolic pathway influence response to therapy, but pharmacogenomic studies of patients treated with TOR are lacking. In this study, we examined individual variability in sulfation of 4-hydroxy TOR (4-OH TOR) (the active metabolite of TOR) in human liver cytosols from 104 subjects and found approximately 30-fold variation in activity. 4-OH TOR sulfation was significantly correlated (r = 0.98, P < 0.0001) with ß-naphthol sulfation (diagnostic for SULT1A1) but not with 17ß estradiol sulfation, a diagnostic substrate for SULT1E1(r = 0.09, P = 0.34). Examination of recombinant sulfotransferases (SULTs) revealed that SULT1A1 and SULT1E1 catalyzed 4-OH TOR sulfation, with apparent Km values of 2.6 and 6.4 µM and Vmax values of 8.5 and 5.5 nmol x min(-1) x mg protein(-1), respectively. 4-OH TOR sulfation was inhibited by 2,6-dichloro-4-nitrophenol (IC50 = 2.34 ± 0.19 µM), a specific inhibitor of SULT1A1. There was also a significant association between SULT1A1 genotypes and copy number and 4-OH TOR sulfation in human liver cytosols. These results indicate that variability in sulfation could contribute to response to TOR in the treatment of breast and prostate cancer.
Subject(s)
Arylsulfotransferase/genetics , Arylsulfotransferase/metabolism , Genetic Variation/physiology , Pharmacogenetics , Tamoxifen/analogs & derivatives , Toremifene/metabolism , Adolescent , Adult , Aged , Aged, 80 and over , Child , Female , Humans , Liver/metabolism , Male , Middle Aged , Pharmacogenetics/methods , Protein Isoforms/genetics , Protein Isoforms/metabolism , Selective Estrogen Receptor Modulators/metabolism , Tamoxifen/metabolism , Young AdultABSTRACT
Although substantial nutrition transition, characterized by an increased intake of energy, animal fat, and red meats, has occurred during the last several decades in East Asia, few studies have systematically evaluated temporal trends in cancer incidence or mortality among populations in this area. Therefore, we sought to investigate this question with tremendous public health implications. Data on mortality rates of cancers of the breast, colon, prostate, esophagus, and stomach for China (1988-2000), Hong Kong (1960-2006), Japan (1950-2006), Korea (1985-2006), and Singapore (1963-2006) were obtained from WHO. Joinpoint regression was used to investigate trends in mortality of these cancers. A remarkable increase in mortality rates of breast, colon, and prostate cancers and a precipitous decrease in those of esophageal and stomach cancers have been observed in selected countries (except breast cancer in Hong Kong) during the study periods. For example, the annual percentage increase in breast cancer mortality was 5.5% (95% confidence interval: 3.8, 7.3%) for the period 1985-1993 in Korea, and mortality rates for prostate cancer significantly increased by 3.2% (95% confidence interval: 3.0, 3.3%) per year from 1958 to 1993 in Japan. These changes in cancer mortality lagged â¼ 10 years behind the inception of the nutrition transition toward a westernized diet in selected countries or regions. There have been striking changes in mortality rates of breast, colon, prostate, esophageal, and stomach cancers in East Asia during the last several decades, which may be at least in part attributable to the concurrent nutrition transition.
Subject(s)
Breast Neoplasms/mortality , Colonic Neoplasms/mortality , Esophageal Neoplasms/mortality , Nutritional Status , Prostatic Neoplasms/mortality , Stomach Neoplasms/mortality , Asia, Eastern/epidemiology , Female , Humans , Male , Mortality/trends , Singapore/epidemiologyABSTRACT
BACKGROUND: In estrogen responsive MCF-7 cells, estradiol (E2) binding to ERα leads to transcriptional regulation of genes involved in the control of cell proliferation and survival. MicroRNAs (miRNAs) have emerged as key post-transcriptional regulators of gene expression. The aim of this study was to explore whether miRNAs were involved in hormonally regulated expression of estrogen responsive genes. METHODS: Western blot and QPCR were used to determine the expression of estrogen responsive genes and miRNAs respectively. Target gene expression regulated by miRNAs was validated by luciferase reporter assays and transfection of miRNA mimics or inhibitors. Cell proliferation was evaluated by MTS assay. RESULTS: E2 significantly induced bcl-2, cyclin D1 and survivin expression by suppressing the levels of a panel of miRNAs (miR-16, miR-143, miR-203) in MCF-7 cells. MiRNA transfection and luciferase assay confirmed that bcl-2 was regulated by miR-16 and miR-143, cyclinD1 was modulated by miR-16. Importantly, survivin was found to be targeted by miR-16, miR-143, miR-203. The regulatory effect of E2 can be either abrogated by anti-estrogen ICI 182, 780 and raloxifene pretreatment, or impaired by ERα siRNA, indicating the regulation is dependent on ERα. In order to investigate the functional significance of these miRNAs in estrogen responsive cells, miRNAs mimics were transfected into MCF-7 cells. It revealed that overexpression of these miRNAs significantly inhibited E2-induced cell proliferation. Further study of the expression of the miRNAs indicated that miR-16, miR-143 and miR-203 were highly expressed in triple positive breast cancer tissues, suggesting a potential tumor suppressing effect of these miRNAs in ER positive breast cancer. CONCLUSIONS: These results demonstrate that E2 induces bcl-2, cyclin D1 and survivin by orchestrating the coordinate downregulation of a panel of miRNAs. In turn, the miRNAs manifest growth suppressive effects and control cell proliferation in response to E2. This sheds a new insight into the integral post-transcriptional regulation of cell proliferation and survival genes by miRNAs, a potential therapeutic option for breast cancer.
Subject(s)
Breast Neoplasms/genetics , Estradiol/pharmacology , Estrogens/pharmacology , MicroRNAs/metabolism , Blotting, Western , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Cell Line, Tumor , Cell Proliferation/drug effects , Cyclin D/metabolism , Female , Gene Expression Regulation, Neoplastic , Genes, bcl-2/drug effects , Humans , Inhibitor of Apoptosis Proteins/metabolism , MicroRNAs/antagonists & inhibitors , MicroRNAs/genetics , Polymerase Chain Reaction/methods , SurvivinABSTRACT
To investigate whether polymorphisms in genes related to oxidative stress act alone or in combination with antioxidants to modulate pancreatic cancer risk. Cases (n=189), ages ≥ 20 years, were ascertained in 1994-1998 from all hospitals in the Twin Cities and the Mayo Clinic. Controls (n=486) were randomly selected from the general population and frequency matched to cases by age and sex. After adjustment for confounders, individuals who were homozygous or heterozygous for the variant allele of SOD2 polymorphism (Ala16Val, rs4880) experienced a 43% lower risk than those who were homozygous for the wild-type allele [OR (95% CI): 0.57 (0.37, 0.89)]. Conversely, an increased risk was observed for the variant allele of hOGG1 polymorphism (Ser326Cys, rs1052133) compared with the wild-type allele [OR (95% CI) for Ser/Cys or Cys/Cys vs. Ser/Ser: 1.57 (1.04, 2.39)]. The protective effect of the variant allele of SOD2 was more pronounced among subjects with a low dietary intake (
ABSTRACT
The effect of feeding grape pomace on certain metabolic parameters associated with high fructose (HF) feeding was studied. Forty male growing Sprague-Dawley rats were randomly assigned into groups: (1) control; (2) HF; (3) HF with low-level (1.5% of diet) grape pomace (HF+LP), and (4) HF with high-level (5.0% of diet) grape pomace (HF+HP). The HF+LP and HF+HP diets provided 115 and 218 mg of procyanidins/kg, respectively. Compared with the controls, HF-fed animals consumed less and were smaller, whereas animals in the HF+LP and HF+HP groups were in between. A similar trend was observed for abdominal fat and abdominal fat as a percentage of body weight. No change in heart or kidney weight occurred. Liver weight as a percentage of body weight was higher for animals when fructose was included in the diet compared with those on control diet, and inclusion of grape pomace had no effect. Fasting plasma glucose, insulin, and triglyceride levels tended to be higher in animals fed HF diet, and grape pomace reduced their levels to values similar to the control animals. Compared with control animals, HF-fed animals had higher weekly postprandial plasma triglycerides, which were reduced by feeding grape pomace, but no change in plasma cholesterol was observed. Glucose intolerance was observed in animals fed HF diet and was accompanied by a 25% increase in homeostatic model assessment (HOMA) of insulin resistance. Inclusion of grape pomace increased glucose tolerance and insulin sensitivity. No significant change (P>.1) in HOMA of ß-cell function or Quantitative Insulin-Sensitivity Check Index was observed. Overall, HF diet did not produce as strong a response of metabolic syndrome as has been shown in the literature. The inclusion of grape pomace in the diet was effective in modulating some aspects of metabolic parameters associated with metabolic syndrome, and the higher level of grape pomace in the diet produced a slightly better response than the lower level.
Subject(s)
Fructose/administration & dosage , Metabolic Syndrome/metabolism , Plant Extracts/pharmacology , Vitis/chemistry , Animals , Blood Glucose/drug effects , Body Weight/drug effects , Diet , Fasting , Fruit/chemistry , Glucose Intolerance/physiopathology , Glucose Tolerance Test , Insulin/blood , Insulin Resistance , Insulin-Secreting Cells/drug effects , Insulin-Secreting Cells/metabolism , Liver/metabolism , Male , Rats , Rats, Sprague-Dawley , Triglycerides/bloodABSTRACT
Fulvestrant (Faslodex™) is a pure antiestrogen that is approved to treat hormone receptor-positive metastatic breast cancer in postmenopausal women. Previous studies have demonstrated that fulvestrant metabolism in humans involves cytochromes P450 and UDP-glucuronosyltransferases (UGTs). To date, fulvestrant sulfation has not been characterized. This study examined fulvestrant sulfation with nine recombinant sulfotransferases and found that only SULT1A1 and SULT1E1 displayed catalytic activity toward this substrate, with K(m) of 4.2 ± 0.99 and 0.2 ± 0.16 µM, respectively. In vitro assays of 104 human liver cytosols revealed marked individual variability that was highly correlated with ß-naphthol sulfation (SULT1A1 diagnostic substrate; r = 0.98, P < 0.0001), but not with 17ß-estradiol sulfation (SULT1E1 diagnostic substrate; r = 0.16, P = 0.10). Fulvestrant sulfation was correlated with both SULT1A1*1/2 genotype (P value = 0.023) and copy number (P < 0.0001). These studies suggest that factors influencing SULT1A1/1E1 tissue expression and/or enzymatic activity could influence the efficacy of fulvestrant therapy.
ABSTRACT
Sulfotransferase isoform 1A1 (SULT1A1) is the most highly expressed hepatic sulfotransferase and is involved in the biotransformation of a wide variety of endo- and xenobiotics. A common single nucleotide polymorphism (SNP) in the coding region of SULT1A1, several proximal promoter SNPs, and copy number variation (CNV) are associated with altered enzymatic activity, but these variants do not fully account for the observed variation of SULT1A1 activity in human populations. In order to identify additional SNPs modulating SULT1A1 activity, we examined the 3'-untranslated region (UTR) of SULT1A1 in 97 liver samples. Direct sequencing revealed that two SNPs in the 3'-UTR (902A > G [rs6839] and 973C > T [rs1042157]) and one SNP in the 3'-flanking region (1307G > A [rs4788068]) were common. These SNPs are in absolute linkage disequilibrium with each other and in tight linkage with SULT1A1 1/2 (linkage coefficient D' 0.83) and are significantly associated with SULT1A1 messenger RNA (p = 0.001, 0.029, 0.021) and enzymatic activity (p = 0.022, 0.012, 0.027). We then examined the collective effects of 3'-UTR SNPs, SULT1A1 1/2, and CNV on SULT1A1 activity in 498 Caucasian and 127 African-American subjects by haplotype analysis. This analysis revealed that SULT1A1 1/2 does not contribute to the variation in SULT1A1 enzymatic activity when the 3'-UTR SNPs are included in the statistical model. Two major haplotypes (ACG and GTA) were significantly correlated with SULT1A1 activity, and when stratified by copy number, the SULT1A1 3'-UTR SNPs remain significantly associated with SULT1A1 enzymatic activity in Caucasians, but not in African-Americans. Subsequent functional characterization revealed that a microRNA, miR-631, regulates SULT1A1 expression in a genotype-specific manner.
Subject(s)
3' Untranslated Regions/genetics , Arylsulfotransferase/genetics , Gene Expression Regulation, Enzymologic , Polymorphism, Single Nucleotide/genetics , Adult , Aged , Aged, 80 and over , Arylsulfotransferase/metabolism , Blood Platelets/enzymology , Cytosol/enzymology , Enzyme Activation/genetics , Female , Genotype , Humans , Linkage Disequilibrium , Liver/enzymology , Male , MicroRNAs/genetics , Middle AgedABSTRACT
BACKGROUND: Presence of xenotropic murine leukemia virus-related virus and chronic inflammation in prostate tumor suggests that inflammation plays a role in prostate cancer etiology. This study investigated whether variants in inflammatory genes act alone or interact with plasma antioxidants to influence prostate cancer risk in a population-based case-control study in Central Arkansas. METHODS: Cases (n = 193) were men, aged 40-80, diagnosed with prostate cancer in three major hospitals in 1998-2003, and controls (n = 197) were matched to cases by age, race, and county of residence. RESULTS: After adjustment for confounders, polymorphisms in COX-2 (rs689466) and IL-8 (rs4073) were not significantly associated with prostate cancer risk. However, apparent interactions were observed between these genetic variants and plasma antioxidants on the risk of this malignancy. The protective effect of the mutant allele of the COX-2 polymorphism was more pronounced among subjects with high plasma levels of beta-cryptoxanthin, lycopene, beta-carotene, or selenium (>or=median) [e.g., OR (95% CI): 0.37 (0.15, 0.86) (AG/GG vs. AA) for beta-cryptoxanthin]. Conversely, the promoting effect of the variant allele of the IL-8 polymorphism was more remarkable in subjects with low plasma levels of Lutein/zeaxanthin, beta-cryptoxanthin, and beta-carotene (Subject(s)
Antioxidants/analysis
, Cyclooxygenase 2/genetics
, Inflammation/genetics
, Interleukin-8/genetics
, Prostatic Neoplasms/genetics
, Adult
, Aged
, Aged, 80 and over
, Case-Control Studies
, Chromatography, High Pressure Liquid
, Genetic Predisposition to Disease
, Genotype
, Humans
, Male
, Middle Aged
, Oligonucleotide Array Sequence Analysis
, Polymorphism, Single Nucleotide
, Prostatic Neoplasms/blood
, Risk Factors
ABSTRACT
OBJECTIVES: To investigate whether polymorphisms in genes involved in the repair of oxidative DNA damage, modulate, and/or interact with antioxidants to influence prostate cancer risk in a population-based case-control study in Central Arkansas. Accumulating evidence indicates that oxidative stress plays a role in prostate carcinogenesis. METHODS: Cases (n = 193) included men aged 40-80 years, diagnosed with prostate cancer in 3 major hospitals in 1998-2003, and controls (n = 197) were matched to cases by age, race, and county of residence. RESULTS: After adjustment for confounders, subjects who were heterozygous or homozygous for the variant allele of the hOGG1 Ser326Cys polymorphism appeared to experience a lower risk of prostate cancer than those who were homozygous for the wild-type allele (odds ratio [OR] (95% confidence interval [CI]): 0.72 (0.46-1.10)]. Conversely, a significant increased risk was observed for individuals who carried 1 or 2 copies of the variant allele of the XRCC1 Arg399Gln polymorphism, compared with those who only harbored the wild-type allele (OR [95% CI]: 1.56 [1.01-2.45]). The above-mentioned associations were generally more pronounced among subjects with low plasma carotenoids or alpha-tocopherol (Subject(s)
Antioxidants/analysis
, DNA Glycosylases/genetics
, DNA-Binding Proteins/genetics
, Polymorphism, Genetic
, Prostatic Neoplasms/blood
, Prostatic Neoplasms/genetics
, Adult
, Aged
, Aged, 80 and over
, Case-Control Studies
, DNA Repair
, Humans
, Male
, Middle Aged
, Risk Factors
, X-ray Repair Cross Complementing Protein 1