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1.
Respir Med ; 102(1): 32-41, 2008 Jan.
Article in English | MEDLINE | ID: mdl-17996436

ABSTRACT

The aim of these studies was to compare the efficacy and the safety of tiotropium, delivered via Respimat Soft Mist Inhaler (SMI), a novel multi-dose, propellant-free inhaler, with ipratropium pressurized metered-dose inhaler (pMDI) in chronic obstructive pulmonary disease (COPD) patients. Two identical, 12-week, multi-national, randomized, double-blind, double-dummy, parallel-group, active- and placebo-controlled studies were performed. COPD patients were randomized to treatment with either inhaled tiotropium (5 or 10 microg) via Respimat SMI administered once daily, ipratropium (36 microg) pMDI QID or placebo. The primary endpoint was the mean trough forced expiratory volume in 1s (FEV(1)) response after 12 weeks of treatment. Secondary endpoints included other spirometry measures and rescue medication use. A total of 719 patients were randomized; the majority were male (69%) with a mean pre-bronchodilator FEV(1) (% predicted) of 40.7%. The mean treatment differences between tiotropium 5 and 10 microg and placebo for the primary endpoint (mean trough FEV(1) response at week 12) were 0.118 and 0.149L, respectively (both P<0.0001). Treatment differences between tiotropium 5 and 10 microg and ipratropium were 0.064L (P=0.006) and 0.095L (P<0.0001). The increases in peak FEV(1), FEV(1) AUC((0-6h)) and FVC for both tiotropium doses were statistically superior to placebo (P<0.01) and higher than ipratropium. All active treatments significantly reduced the rescue medication use compared with placebo, but only tiotropium 10 microg was statistically superior to ipratropium (P=0.04). The incidence of adverse events was comparable across groups. In conclusion, tiotropium 5 and 10 microg daily, delivered via Respimat SMI, significantly improved lung function compared with ipratropium pMDI and placebo.


Subject(s)
Bronchodilator Agents/administration & dosage , Ipratropium/administration & dosage , Nebulizers and Vaporizers , Pulmonary Disease, Chronic Obstructive/drug therapy , Scopolamine Derivatives/administration & dosage , Adult , Aged , Bronchodilator Agents/adverse effects , Dose-Response Relationship, Drug , Double-Blind Method , Drug Administration Schedule , Female , Humans , Ipratropium/adverse effects , Male , Middle Aged , Scopolamine Derivatives/adverse effects , Tiotropium Bromide
2.
Pulm Pharmacol Ther ; 18(6): 397-404, 2005.
Article in English | MEDLINE | ID: mdl-16179215

ABSTRACT

BACKGROUND: The Global Initiative for Chronic Obstructive Lung Disease (GOLD) recommends long-acting bronchodilators as first-line maintenance treatment for patients with chronic obstructive pulmonary disease (COPD). A study was conducted comparing the long-acting anticholinergic tiotropium with the long-acting beta-agonist salmeterol to confirm the significant improvements in daytime bronchodilator efficacy seen with tiotropium in previous studies. METHODS: Randomized, double-blind, double-dummy, parallel-group study, comparing daytime bronchodilator efficacy of tiotropium 18 mcg once daily with salmeterol 50 mcg twice daily in patients with COPD. Serial spirometry was performed over 12 h after 12 weeks of treatment. Co-primary endpoints were average (over 12 h) and peak FEV1 at 12 weeks. RESULTS: 653 patients were randomized (328 tiotropium, 325 salmeterol): mean age 64 years; 66% male; mean baseline FEV1 1.05 l (37.7% predicted). After 12 weeks, the average post-dose FEV1 over 12 h was significantly higher with tiotropium compared with salmeterol (167 vs. 130 mL, respectively, p=0.03), as was peak FEV1 (262 vs. 216 ml, respectively, p=0.01). The average FEV1 responses from 0-6 h and 6-12 h were higher in the tiotropium group compared with salmeterol (p<0.05). Peak and average FVC were significantly higher with tiotropium compared with salmeterol (p<0.01). Morning pre-dose FEV1 responses were not significantly different; however, tiotropium demonstrated a significantly higher pre-dose FVC than salmeterol (p<0.05). CONCLUSION: Tiotropium demonstrated significantly greater post-dose improvements in spirometric parameters compared with salmeterol. These improvements were sustained over 12 h.


Subject(s)
Albuterol/analogs & derivatives , Bronchodilator Agents/pharmacology , Bronchodilator Agents/therapeutic use , Pulmonary Disease, Chronic Obstructive/drug therapy , Scopolamine Derivatives/pharmacology , Scopolamine Derivatives/therapeutic use , Aged , Albuterol/pharmacokinetics , Albuterol/pharmacology , Albuterol/therapeutic use , Bronchodilator Agents/pharmacokinetics , Double-Blind Method , Drug Administration Schedule , Female , Forced Expiratory Volume , Humans , Male , Middle Aged , Salmeterol Xinafoate , Scopolamine Derivatives/pharmacokinetics , Tiotropium Bromide , Treatment Outcome
3.
Ann Allergy Asthma Immunol ; 86(1): 19-27, 2001 Jan.
Article in English | MEDLINE | ID: mdl-11206232

ABSTRACT

BACKGROUND: Formoterol is a beta2-adrenergic agent which, when inhaled, produces rapid and long-lasting bronchodilatation. OBJECTIVE: The aim of this study was to compare the efficacy, safety, and tolerability of formoterol powder for inhalation delivered via the Aerolizer device with placebo and with albuterol delivered via metered-dose inhaler in patients with mild to moderate persistent asthma. METHODS: In a multicenter, double-blind, parallel-group study, 541 patients were randomized at 26 trial sites to receive either formoterol, 12 microg twice daily; formoterol, 24 microg twice daily; albuterol, 180 microg four times daily; or a placebo for 12 weeks. The effects of each treatment on lung function, asthma symptoms, and frequency of rescue albuterol use were evaluated. Adverse effects and clinical laboratory parameters were also evaluated. RESULTS: The bronchodilatory effects of formoterol were rapid in onset and persisted for 12 hours. Both formoterol doses were more effective than placebo and albuterol for objective measures of lung function. Morning and evening peak expiratory flow rates were more improved with formoterol, and formoterol provided significantly greater improvements in asthma symptom scores compared with both albuterol and placebo. Overall, patients taking formoterol used significantly less rescue medication than did those taking albuterol or placebo. Nocturnal awakenings occurred less often with formoterol than with placebo or albuterol. The therapeutic effects of formoterol were maintained over the entire 12 weeks of treatment. Adverse events were similar for all treatment groups, and clinical laboratory data were unremarkable. CONCLUSIONS: Rapid-onset, long-acting formoterol, administered via the Aerolizer inhaler, is an effective and safe treatment for patients with mild to moderate persistent asthma.


Subject(s)
Adrenergic beta-Agonists/administration & dosage , Albuterol/administration & dosage , Bronchodilator Agents/administration & dosage , Ethanolamines/administration & dosage , Administration, Inhalation , Adolescent , Adrenergic beta-Agonists/adverse effects , Adult , Aged , Albuterol/adverse effects , Albuterol/pharmacokinetics , Asthma/drug therapy , Bronchodilator Agents/adverse effects , Child , Ethanolamines/adverse effects , Ethanolamines/pharmacokinetics , Female , Forced Expiratory Volume , Formoterol Fumarate , Humans , Male , Middle Aged , Nebulizers and Vaporizers , Powders , Therapeutic Equivalency
4.
Psychoneuroendocrinology ; 26(1): 37-49, 2001 Jan.
Article in English | MEDLINE | ID: mdl-11070333

ABSTRACT

To date, there are few known predictors of stress-induced eating. The purpose of this study was to identify whether physiological and psychological variables are related to eating after stress. Specifically, we hypothesized that high cortisol reactivity in response to stress may lead to eating after stress, given the relations between cortisol with both psychological stress and mechanisms affecting hunger. To test this, we exposed fifty-nine healthy pre-menopausal women to both a stress session and a control session on different days. High cortisol reactors consumed more calories on the stress day compared to low reactors, but ate similar amounts on the control day. In terms of taste preferences, high reactors ate significantly more sweet food across days. Increases in negative mood in response to the stressors were also significantly related to greater food consumption. These results suggest that psychophysiological response to stress may influence subsequent eating behavior. Over time, these alterations could impact both weight and health.


Subject(s)
Appetite , Eating , Hydrocortisone/blood , Stress, Physiological/physiopathology , Adult , Affect , Body Mass Index , Diet, Reducing , Educational Status , Energy Intake , Female , Food Preferences , Humans , Income , Premenopause
5.
Prostate ; 45(4): 350-4, 2000 Dec 01.
Article in English | MEDLINE | ID: mdl-11102961

ABSTRACT

BACKGROUND: Prostate-specific membrane antigen (PSMA) is a glutamate carboxypeptidase that cleaves terminal carboxy glutamates from both the neuronal dipeptide N-acetylaspartylglutamate (NAAG) and gamma-linked folate polyglutamate. The prostate enzyme has activity in both the membrane and cytosolic fractions termed PSMA and PSMA', respectively. METHODS: Using a NAAG hydrolytic radioenzymatic assay, we quantitated the enzymatic activity of PSMA and PSMA' in normal, benign prostatic hyperplasia (BPH), and prostate cancer (PC) tissues from radical prostatectomies. PSMA enzyme activity was evaluated in each tissue type and expressed per milligram protein and epithelial cell content. RESULTS: PSMA and PSMA' enzyme activities were significantly elevated in prostate cancer when compared to normal prostate tissue and BPH. Ratios of PSMA to PSMA' were also decreased in BPH as compared to cancerous and normal tissue. CONCLUSIONS: Prostate carcinogenesis is associated with an elevation in PSMA and PSMA' enzyme activity. In contrast, no such enhancement in PSMA activity is observed with benign neoplastic changes in BPH. Thus, the enhancement observed in prostate cancer is not simply related to a generalized prostatic hyperplasia, but is specific to its malignancy.


Subject(s)
Antigens, Surface , Carboxypeptidases/metabolism , Prostatic Neoplasms/enzymology , Cell Membrane/enzymology , Cytosol/enzymology , Dipeptides/metabolism , Glutamate Carboxypeptidase II , Humans , Male , Prostate/enzymology , Prostatectomy , Prostatic Hyperplasia/enzymology , Prostatic Neoplasms/surgery
6.
Prostate ; 44(1): 55-60, 2000 Jun 15.
Article in English | MEDLINE | ID: mdl-10861758

ABSTRACT

BACKGROUND: The polysulfonated napthlyurea suramin has shown significant antitumor activity in patients with hormone-refractory metastatic prostate cancer. The mechanism by which suramin exerts this effect is unknown. In 1993, prostate-specific membrane antigen (PSM) was identified as a prostate biomarker that is elevated in hormone-refractory and metastatic prostate cancer. PSM is a glutamate exocarboxypeptidase capable of cleaving the terminal alpha-linked glutamate from the dipeptide N-acetyl-aspartyl-glutamate (NAAG) and the gamma-linked glutamates from folate polyglutamate. METHODS: Using a NAAG hydrolytic radioenzymatic assay, we tested whether suramin had any effect on the enzymatic activity of PSM. RESULTS: We demonstrate that suramin potently inhibits the enzymatic activity of PSM with a K(i) = 15 nM and 68 nM for the membrane-associated and soluble forms of PSM, respectively. In addition, we show that suramin inhibition of PSM enzyme activity displays the kinetics of a classic competitive inhibitor. CONCLUSIONS: This is one of the most potent activities described for suramin to date and may represent a portion of its pharmacologic and/or toxicological mechanism of action.


Subject(s)
Antigens, Surface , Antineoplastic Agents/pharmacology , Carboxypeptidases/antagonists & inhibitors , Prostatic Neoplasms/enzymology , Suramin/pharmacology , Carboxypeptidases/metabolism , Chromatography, Ion Exchange , Dipeptides/chemistry , Dose-Response Relationship, Drug , Glutamate Carboxypeptidase II , Humans , Male , Phosphates/chemistry , Prostatic Neoplasms/drug therapy , Quisqualic Acid/chemistry , Scintillation Counting , Tumor Cells, Cultured
7.
Ann Allergy Asthma Immunol ; 84(4): 417-24, 2000 Apr.
Article in English | MEDLINE | ID: mdl-10795650

ABSTRACT

BACKGROUND: Although inhaled glucocorticoids are recommended for all stages of persistent asthma, compliance with long-term therapy is often poor, leading to significant morbidity and mortality. A simplified, once-daily dosing regimen may foster improved compliance. OBJECTIVE: To compare the efficacy and safety of once-daily (AM) administration of mometasone furoate dry powder inhaler (MF DPI) 200 microg and 400 microg with placebo in patients with asthma previously maintained only on short-acting inhaled beta-adrenergic receptor agonists. METHODS: This was a 12-week, double-blind, placebo-controlled, parallel group study. The mean change from baseline to endpoint (last treatment visit) for FEV1 was the primary efficacy variable. RESULTS: At endpoint, both doses of MF DPI were significantly more effective than placebo (P < or = .05) in improving FEV1. Based on morning peak expiratory flow rate, once-daily MF DPI 400 microg was more effective than placebo (P < or = .001) at endpoint. Both active treatments also demonstrated improvement at endpoint in asthma symptom scores, physician-evaluated response to therapy and use of rescue medication. Although both MF DPI dosages were efficacious, MF DPI 400 microg provided additional improvement in some measures of pulmonary function (eg, morning PEFR) when these agents were administered once daily in the morning. Both doses of MF DPI were well tolerated and treatment-related adverse events occurred at a similar incidence among the three treatment groups. CONCLUSIONS: The results of this study indicate that once-daily (AM) MF DPI provides a convenient and effective treatment option for patients with mild or moderate persistent asthma.


Subject(s)
Anti-Asthmatic Agents/therapeutic use , Anti-Inflammatory Agents/therapeutic use , Asthma/drug therapy , Pregnadienediols/therapeutic use , Adolescent , Adult , Aged , Anti-Asthmatic Agents/administration & dosage , Anti-Inflammatory Agents/administration & dosage , Child , Double-Blind Method , Drug Administration Schedule , Female , Humans , Male , Middle Aged , Mometasone Furoate , Pregnadienediols/administration & dosage , Quality of Life , Respiratory Function Tests , Treatment Outcome
8.
Prostate ; 39(1): 28-35, 1999 Apr 01.
Article in English | MEDLINE | ID: mdl-10221263

ABSTRACT

BACKGROUND: The prostate cancer marker prostate-specific membrane antigen (PSM) is highly homologous to the brain enzyme N-acetylated alpha-linked acidic dipeptidase (NAALADase). NAALADase is known to cleave terminal carboxy glutamates from both the neuronal peptide N-acetylaspartylglutamate (NAAG) and folate polyglutamate. In this report, we compare the NAAG hydrolyzing activity of NAALADase and the prostate enzyme PSM. METHODS: Using a NAAG hydrolytic radioenzymatic assay, we compared the pharmacological and kinetic properties of the brain and prostate enzymes. RESULTS: Eight normal prostate tissues from different species exhibited NAAG hydrolyzing activity. Among 14 cancer cell lines examined, activity was observed in human LNCaP, PC-82, and rat Dunning G and AT-1 cells. Brain exhibited membrane-localized activity exclusively, while the prostate enzyme had activity in both membrane and cytosolic fractions. The only observed pharmacological difference was the sensitivity to their putative substrates, folate polyglutamate and NAAG. Kinetically, the soluble form of the prostate enzyme had two catalytic sites, while the membrane-bound form exhibited single site kinetics with a lower Vmax than the brain enzyme, which may suggest a less active hydrolase in the prostate. CONCLUSIONS: The brain enzyme NAALADase and the prostate enzyme PSM are remarkably similar. The importance of the differences in substrate specificities and kinetic parameters remains to be elucidated.


Subject(s)
Antigens, Neoplasm/metabolism , Antigens, Surface , Brain/enzymology , Carboxypeptidases/metabolism , Prostatic Neoplasms/enzymology , Animals , Glutamate Carboxypeptidase II , Humans , Kinetics , Male , Rats , Rats, Sprague-Dawley , Tumor Cells, Cultured
9.
Clin Cancer Res ; 5(12): 4242-8, 1999 Dec.
Article in English | MEDLINE | ID: mdl-10632366

ABSTRACT

The efficacy of systemic chemotherapy for non-small cell lung cancer (NSCLC) has improved with newer agents. However, the response rates and prolonged survival times achieved by chemotherapy remain modest, and these small gains are obtained at the cost of significant toxicity. In this study, the efficacy of a controlled release formulation of paclitaxel was compared with conventional paclitaxel in animals with human lung cancer xenografts. Paclitaxel (10%) was encapsulated in a proprietary polymer in the form of microspheres (PACLIMER Delivery System). Tumor nodules comprised of two different cell lines (A549 and H1299) were treated by a single i.p. or intratumoral administration of conventionally formulated paclitaxel or a single intratumoral injection of the PACLIMER Delivery System. In vitro testing demonstrated that paclitaxel was released slowly from the microspheres with >80% released after 90 days. Direct comparison of the highest dose for all formulations (24 mg/kg) showed that for nodules comprised of either NSCLC cell line, growth of the PACLIMER Delivery System-treated nodules were inhibited significantly more than the groups treated with conventional paclitaxel or the vehicle controls. Tumor volume doubling times for A549 and H1299 nodules treated with PACLIMER Delivery System were 60 and 35 days, respectively, compared with 10 and 11 days, respectively, in the nodules treated with the conventional paclitaxel by intratumoral administration. We conclude that intratumoral administration of the PACLIMER Delivery System may substantially increase the efficacy of paclitaxel for the therapy of local-regional NSCLC.


Subject(s)
Antineoplastic Agents, Phytogenic/administration & dosage , Carcinoma, Non-Small-Cell Lung/drug therapy , Drug Delivery Systems , Growth Inhibitors/administration & dosage , Lung Neoplasms/drug therapy , Paclitaxel/administration & dosage , Animals , Antineoplastic Agents, Phytogenic/chemistry , Carcinoma, Non-Small-Cell Lung/pathology , Delayed-Action Preparations , Growth Inhibitors/chemistry , Humans , Injections, Intralesional , Injections, Intraperitoneal , Lung Neoplasms/pathology , Mice , Mice, Inbred BALB C , Mice, Nude , Microspheres , Neoplasm Transplantation , Paclitaxel/chemistry , Transplantation, Heterologous , Tumor Cells, Cultured
10.
Oncogene ; 17(5): 577-83, 1998 Aug 06.
Article in English | MEDLINE | ID: mdl-9704923

ABSTRACT

Progesterone receptor (PR) is an estrogen-stimulated gene which has a CpG island that is heavily methylated in a significant fraction of estrogen receptor (ER)-negative/PR-negative human breast cancers and cell lines, including MDA-MB-231 cells. Treatment of MDA-MB-231 cells with the demethylating agent, 5-aza-2'-deoxycytidine (deoxyC) led to demethylation and expression of ER and PR. However, simultaneous treatment with antiestrogen prevented PR transcription, suggesting that demethylation of PR alone is not sufficient to reactivate the PR gene. To examine the effects of ER on the methylation status of the PR CpG island, we stably transfected MDA-MB-231 cells with an inducible expression vector for ER. Surprisingly, in two cell clones, we found that induction of PR gene expression by ligand-bound ER does not require demethylation of the PR CpG island. In contrast, induction of PR transcription was inhibited by blocking the interaction of ER with SRC-1A, a coactivator of ER function. For the first time, we show that a transcription factor with the potential to remodel heterochromatin can activate gene expression without altering the methylation status of the CpG island. These results raise the possibility that demethylation and histone acetylation are distinct but complementary mechanisms for destabilizing heterochromatin and activating transcription.


Subject(s)
CpG Islands , DNA Methylation , Gene Expression Regulation , Receptors, Progesterone/genetics , Azacitidine/analogs & derivatives , Azacitidine/pharmacology , DNA Modification Methylases/antagonists & inhibitors , Decitabine , Estradiol/analogs & derivatives , Estradiol/pharmacology , Estrogen Antagonists/pharmacology , Fulvestrant , Histone Acetyltransferases , Humans , Nuclear Receptor Coactivator 1 , Receptors, Estrogen/metabolism , Receptors, Steroid/genetics , Receptors, Steroid/metabolism , Transcription Factors/genetics , Transcription Factors/metabolism , Tumor Cells, Cultured
11.
Cancer Res ; 58(12): 2515-9, 1998 Jun 15.
Article in English | MEDLINE | ID: mdl-9635570

ABSTRACT

Southern analysis has shown that DNA from 25% of primary estrogen receptor (ER) alpha-negative breast tumors displays aberrant methylation at one site within the ER gene CpG island. To examine more sites and increase sensitivity, we developed a methylation-specific PCR assay to map methylation of the entire ER CpG island. The island was unmethylated in normal breast tissue and ER-positive breast cancer cell lines, but extensively methylated in all ER-negative cell lines and breast tumors examined. In addition, some of the ER-positive/progesterone receptor-negative and ER-positive/progesterone receptor-positive tumors (about 70% and 35%, respectively) displayed methylation of the ER CpG island, suggesting that this heterogeneity within tumor cell populations could potentially shed light on the etiology of ER-negative recurrent tumors arising from ER-positive tumors.


Subject(s)
Breast Neoplasms/genetics , CpG Islands/genetics , DNA Methylation , DNA, Neoplasm/genetics , Receptors, Estrogen/genetics , Adult , Aged , Aged, 80 and over , DNA, Neoplasm/metabolism , Female , Genetic Markers/genetics , Humans , Middle Aged , Polymerase Chain Reaction/methods , Tumor Cells, Cultured
13.
J Mammary Gland Biol Neoplasia ; 3(1): 85-94, 1998 Jan.
Article in English | MEDLINE | ID: mdl-10819507

ABSTRACT

Hormone responsiveness is a critical determinant of breast cancer progression and management, and the response to endocrine therapy is highly correlated with the estrogen receptor (ER)3 and progesterone receptor (PR) status of tumor cells. Thus, key areas of study in breast cancer are those mechanisms that regulate ER and PR expression in normal and malignant breast tissues. One-third of all breast cancers lack ER and PR; these conditions are associated with less differentiated tumors and poorer clinical outcome. In addition, approximately one-half of ER-positive tumors lack PR protein and patients with this phenotype are less likely to respond to hormonal therapies than those whose tumors express both receptors. Since PR is induced by ER; its presence is a marker of a functional ER. In this review, we will discuss possible mechanisms for loss of ER and PR gene expression, especially structural changes within each gene including deletions, polymorphisms or methylation. Improved understanding of the pathways that lead to loss of ER and/or PR proteins should allow the development of better predictive indicators as well as novel therapeutic approaches to target these hormone-independent cancers.


Subject(s)
Breast Neoplasms/genetics , Gene Expression Regulation, Neoplastic , Receptors, Estrogen/genetics , Receptors, Progesterone/genetics , DNA Methylation , Female , Humans , Mutation
14.
Harefuah ; 135(1-2): 8-9, 88, 87, 1998 Jul.
Article in Hebrew | MEDLINE | ID: mdl-10909522

ABSTRACT

270 consecutive electroencephalograms (EEGs) performed in a psychiatric hospital were reviewed. 194 (75%) were within normal limits but 66 (25%) showed diffuse generalized slowing. The contribution of the abnormal EEGs to diagnosis and treatment was evaluated by retrospective file review. In none of the cases with abnormal EEGs was there a relationship to diagnosis or treatment.


Subject(s)
Electroencephalography , Psychotic Disorders/physiopathology , Hospital Bed Capacity, 300 to 499 , Hospitals, Psychiatric , Humans , Israel , Reference Values , Retrospective Studies
15.
Clin Cancer Res ; 2(5): 805-10, 1996 May.
Article in English | MEDLINE | ID: mdl-9816234

ABSTRACT

Hormonal factors have a profound influence on the development, treatment, and outcome of breast cancer. The absence of steroid hormone receptors is highly correlated with resistance to antihormonal treatments. Work in cultured human breast cancer cell lines has shown that the absence of estrogen receptor (ER) gene expression in ER- cells is associated with extensive methylation of the ER gene 5' CpG island, and treatment with agents that demethylate the ER gene CpG island results in the production of functional ER protein. The current study shows that CpG islands in the 5' region of the ER and progesterone receptor (PR) genes are methylated in a significant fraction of primary human breast cancer tissues. The ER CpG island is methylated at the methylation-sensitive NotI restriction site in 9 of 39 (25%) of primary ER- breast cancers but remains unmethylated in 53 ER+ breast cancers and 9 normal breast specimens. Three methylation-sensitive restriction sites in the PR gene CpG island are not methylated in normal breast specimens and PR+ human breast cancers but are hypermethylated in 40% of PR- human breast tumors. These data demonstrate that methylation of the ER and PR gene CpG islands is associated with the lack of ER and PR gene expression in a significant fraction of human breast cancers.


Subject(s)
Breast Neoplasms/genetics , CpG Islands , DNA Methylation , Receptors, Estrogen/genetics , Receptors, Progesterone/genetics , Female , Gene Expression , Humans , Tumor Cells, Cultured
16.
Cancer Res ; 55(22): 5195-9, 1995 Nov 15.
Article in English | MEDLINE | ID: mdl-7585573

ABSTRACT

Expression of the Ca(2+)-dependent, homotypic cell:cell adhesion molecule, E-cadherin (E-cad), suppresses tumor cell invasion and metastasis in experimental tumor models. Decreased E-cad expression is common in poorly differentiated, advanced-stage carcinomas. These data implicate E-cad as an "invasion suppressor" gene. The mechanism by which E-cad is silenced in advanced stage carcinomas is unclear. In this report, we show that: (a) the 5' CpG island of E-cad is densely methylated in E-cad-negative breast and prostate carcinoma cell lines and primary breast carcinoma tissue but is unmethylated in normal breast tissue; (b) treatment with the demethylating agent, 5-aza-2'-deoxycytidine, partially restores E-cad RNA and protein levels in E-cad-negative breast and prostate carcinoma cell lines; and (c) and E-cad promoter/CAT construct is expressed in both E-cad-positive and -negative breast and prostate carcinoma cell lines, indicating that these cells have the active transcriptional machinery necessary for E-cad expression. Our data demonstrate that frequent loss of E-cad expression in human breast and prostate carcinomas results from hypermethylation of the E-cad promoter region.


Subject(s)
Breast Neoplasms/genetics , Cadherins/genetics , DNA/metabolism , Gene Expression Regulation, Neoplastic , Prostatic Neoplasms/genetics , Base Sequence , Female , Humans , Male , Methylation , Molecular Sequence Data , Tumor Cells, Cultured
17.
Cancer Res ; 55(20): 4525-30, 1995 Oct 15.
Article in English | MEDLINE | ID: mdl-7553621

ABSTRACT

The tumor suppressor gene CDKN2/p16/MTS1, located on chromosome 9p21, is frequently inactivated in many human cancers through homozygous deletion. Recently, we have reported another pathway of inactivation that involves loss of transcription associated with de novo methylation of a 5' CpG island of CDKN2/p16 in lung cancers, gliomas, and head and neck squamous cell carcinomas. We now show that this aberrant CpG island methylation also occurs frequently in cell lines of breast cancer (33%), prostate cancer (60%), renal cancer (23%), and colon cancer (92%) and is associated with loss of transcription. Primary tumors of the breast (31%) and colon (40%) also displayed de novo methylation of this CpG island. This alteration of p16 in colon cancer was particularly striking, since inactivation does not occur through homozygous deletion in this tumor type. Our data show that in tumors, de novo methylation of the 5' CpG island is a frequent mode of inactivation of CDKN2/p16 and also firmly demonstrate that CDKN2/p16 is one of the most frequently altered genes in human neoplasia.


Subject(s)
Carrier Proteins/genetics , CpG Islands , Genes, Tumor Suppressor , Cyclin-Dependent Kinase Inhibitor p16 , DNA, Neoplasm/genetics , Gene Expression Regulation, Neoplastic , Humans , Methylation , Promoter Regions, Genetic , RNA, Neoplasm/genetics , Restriction Mapping , Sequence Deletion
18.
Cancer Res ; 55(11): 2279-83, 1995 Jun 01.
Article in English | MEDLINE | ID: mdl-7538900

ABSTRACT

Approximately one third of breast cancers grow independently of estrogen, lack detectable estrogen receptor (ER) protein, and rarely respond to hormonal treatment. Previous studies correlated the lack of ER gene expression in ER-negative breast tumor cells with hypermethylation of a CpG island in the 5' region of the ER gene. In order to determine whether demethylation of the ER gene in the ER-negative human breast cancer cell line MDA-MB-231 could affect ER transcription, cells were treated with two inhibitors of DNA methylation, 5-azacytidine or 5-aza-2'-deoxycytidine. DNA from cells treated with either drug became partially demethylated at several methylation-sensitive restriction enzyme sites, including HhaI, NotI, and SacII, within the ER CpG island. This demethylation correlated with reexpression of the ER gene as detected by reverse transcriptase-PCR and production of ER protein as detected by Western blot analysis. ER produced in drug-treated cells was functionally active as demonstrated by its ability to activate transcription of estrogen-responsive genes. These results suggest that DNA methylation of the ER CpG island may play a role in suppression of ER gene expression in ER-negative breast cancer cells.


Subject(s)
Breast Neoplasms/genetics , Breast Neoplasms/ultrastructure , Gene Expression Regulation, Neoplastic/physiology , Receptors, Estrogen/genetics , Receptors, Estrogen/metabolism , Antineoplastic Agents/pharmacology , Azacitidine/analogs & derivatives , Azacitidine/pharmacology , Base Sequence , Breast Neoplasms/metabolism , Cytosine/metabolism , DNA, Neoplasm/drug effects , DNA, Neoplasm/genetics , DNA, Neoplasm/metabolism , Decitabine , Gene Expression/drug effects , Gene Expression Regulation, Neoplastic/drug effects , Guanine/metabolism , Humans , Methylation , Molecular Sequence Data , RNA, Messenger/genetics , RNA, Messenger/metabolism , Receptors, Estrogen/physiology , Tumor Cells, Cultured
19.
Radiology ; 195(1): 47-52, 1995 Apr.
Article in English | MEDLINE | ID: mdl-7892494

ABSTRACT

PURPOSE: To determine the optimal cutoff level of fluorine-18-labeled fluorodeoxyglucose (FDG) uptake in the differentiation of low-grade from high-grade cerebral tumors at position emission tomography (PET). MATERIALS AND METHODS: The authors retrospectively reviewed images from PET, magnetic resonance imaging, and computed tomography performed in 58 consecutive patients with histologically proved brain tumors. There were 32 high-grade tumors (20 gliomas) and 26 low-grade tumors (18 gliomas). RESULTS: The best cutoff level of FDG uptake ratios in the differentiation of high-grade from low-grade tumors was 1.5 for tumor-to-white matter (T/WM) ratios and 0.6 for tumor-to-cortex (T/C) ratios. These levels were the same when only gliomas were analyzed and when all tumors were analyzed. When a T/WM ratio of more than 1.5 was considered indicative of a high-grade tumor, the sensitivity and specificity were 94% and 77%, respectively. The results were similar for the T/C ratio. CONCLUSION: Cutoff levels of 1.5 for the T/WM FDG uptake ratio and 0.6 for the T/C ratio are useful in the differentiation of low-grade from high-grade gliomas with PET.


Subject(s)
Brain Neoplasms/diagnostic imaging , Deoxyglucose/analogs & derivatives , Fluorine Radioisotopes , Glioma/diagnostic imaging , Tomography, Emission-Computed , Adult , Brain/diagnostic imaging , Brain/pathology , Brain Neoplasms/pathology , Diagnosis, Differential , Female , Fluorodeoxyglucose F18 , Glioma/pathology , Humans , Magnetic Resonance Imaging , Male , Retrospective Studies , Sensitivity and Specificity , Tomography, X-Ray Computed
20.
Arch Biochem Biophys ; 315(2): 548-54, 1994 Dec.
Article in English | MEDLINE | ID: mdl-7986102

ABSTRACT

This study investigates the role of polymorphic or nonbilayer lipids in the function of an integral membrane protein which is a key component of the mitochondrial energy transduction apparatus. The adenine nucleotide translocator (AdNT) has been isolated from rat heart mitochondria and reconstituted into ATP-containing liposomes composed of dioleoylphosphatidylcholine (DOPC), dioleoylphosphatidylethanolamine (DOPE), and cardiolipin (CL). CL content was held constant at 11.1 mol%; the ratio of DOPC:DOPE was varied to manipulate R0, the intrinsic radius of curvature of the bilayer [S. M. Gruner (1985) Proc. Natl. Acad. Sci. USA 82, 3665-3669]. Translocator activity was determined fluorometrically, using a coupled enzyme system to measure ADP-induced efflux of ATP. Specific activity was calculated based on the number of functional translocators in each preparation, quantified using the tight-binding inhibitor carboxyatractylate (CAT). AdNT specific activity was a smooth function of R0, with a maximum at a lipid composition similar to that of the inner mitochondrial membrane. Protein incorporation was constant at DOPC:DOPE ratios > 1, but appeared to increase at ratios < or = 1. The fraction of reconstituted AdNT incorporated in the native mitochondrial orientation, estimated from inhibition by 10 microM CAT, was independent of lipid composition and > 85%. Leakage of encapsulated ATP increased at low R0 values both in the presence and absence of protein.


Subject(s)
Mitochondria, Heart/chemistry , Mitochondrial ADP, ATP Translocases/chemistry , Animals , Cardiolipins/chemistry , In Vitro Techniques , Liposomes , Membrane Lipids , Permeability , Phosphatidylcholines/chemistry , Phosphatidylethanolamines/chemistry , Rats , Structure-Activity Relationship
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