piperidines and Barrett-Esophagus

Molecular analysis of malignant transformation in Barrett's epithelium provides insight into the temporal nature and significance of individual genetic events during multistep esophageal carcinogenesis. Potential targets for intervention in esophageal neoplasms include mutations involving retinoblastoma (Rb) and p53 tumor-suppressor pathways as well as tyrosine kinase cascades, which are known to promote cell cycle progression. Data from recent experiments provide the preclinical rationale for novel pharmacologic interventions in established esophageal cancers, and suggest strategies for chemoprevention in patients at risk for the development of these neoplasms.

Topics: Adenocarcinoma; Adenoviridae; Antineoplastic Agents; Barrett Esophagus; Cell Transformation, Neoplastic; Esophageal Neoplasms; Flavonoids; Genes, p53; Genetic Vectors; Humans; Piperidines; Precancerous Conditions

Both gastric acid and duodenal juice have been implicated in Barrett's oesophagus. The aim of this study was to look at duodenal reflux in the oesophagus together with motility characteristics in a group of patients with Barrett's oesophagus and compare them with a mild oesophagitis group and to assess the effect of cisapride on any abnormalities.. A prospective study comparing the two groups of patients was carried out.. Twenty patients with histologically proven Barrett's oesophagus and 20 patients with Savary-Miller grade 2 oesophagitis were studied. Standard oesophageal manometric measurements were carried out and on a separate occasion duodenogastro-oesophageal reflux (DGOR) was measured over a 4-h period using a sodium ion selective electrode. Patients with more than 5% DGOR were given cisapride (10 mg four times daily) and the studies repeated after 7 days of treatment.. Barrett's patients showed more DGOR, 12.2% of the study time compared to 5.1% in the mild oesophagitis group, P = 0.012, but manometric findings were not significantly different. Sixteen patients were treated with cisapride. DGOR was reduced in 8 out of 12 Barrett's patients and 2 out of 4 oesophagitis patients, and proximal amplitude and distal oesophageal pressures were significantly elevated (P = 0.05 and P = 0.03, respectively).. Monitoring of sodium ions in the oesophagus shows that patients with Barrett's oesophagus have significantly more DGOR than patients with uncomplicated oesophagitis and cisapride may be effective in removal of this reflux.

Topics: Adult; Aged; Barrett Esophagus; Bile Acids and Salts; Cisapride; Duodenogastric Reflux; Electrodes; Esophagus; Female; Gastroesophageal Reflux; Gastrointestinal Agents; Humans; Intubation, Gastrointestinal; Male; Manometry; Middle Aged; Monitoring, Physiologic; Piperidines; Prospective Studies; Sodium

Role of cyclin dependent kinase 9(CDK9) as a potential target in esophageal adenocarcinoma (EAC) is unknown. We investigated CDK9 protein expression in EAC and Barrett's esophagus and role of CDK9 in oncogenic processes of EAC in vitro and in murine xenografts. The CDK9 expression was significantly higher in EAC as compared to Barrett's esophagus in patient samples. Stable shCDK9 in SKGT4 reduced proliferation by 37% at day 4, increased apoptosis at 48 hours and induced G1 cell cycle arrest at 48 hours (58.4% vs. 45.8%) compared to controls SKGT4 cells. SKGT4-shCDK9 cell-derived tumors were significantly smaller than control SKGT4-derived tumors in xenografts (72.89mm3 vs. 270mm3). Pharmaceutical inhibition of CDK9 by Flavopiridol (0.1µm for 48 hours) and CAN508 (20 and 40µm for 72 hours) induced significant reduction in proliferation and 2-fold increase in apoptosis in SKGT4, FLO1 and OE33 cells. In xenograft models, CAN508 (60 mg/kg/dayx10 days) and Flavopiridol (4mg/kg/dayx10 days) caused 50.8% and 63.1% reduction in xenograft tumors as compared to control on post-treatment day 21. Reduction of MCL-1 and phosphorylated RNA polymerase II was observed with transient shCDK9 in SKGT4 cells but not with stable shCDK9. CAN508 (20 and 40 µm) and Flavopiridol (0.1, 0.2 and 0.3 µm) for 4 hours showed reduction in MCL-1 mRNA (84% and 96%) and protein. Mcl-1 overexpression conferred resistance to Flavopiridol (0.2 µm or 0.4 µm for 48 hours) and CAN 508 (20 or 40µm for 72 hours). Chromatin immunoprecipitation demonstrated significant reduction of binding of transcriptional factor HIF-1α to MCL-1 promoter in FLO-1 cells by CDK9 inhibitors.

Topics: Adenocarcinoma; Aged; Aged, 80 and over; Animals; Apoptosis; Barrett Esophagus; Carcinogenesis; Cell Line, Tumor; Cyclin-Dependent Kinase 9; Esophageal Neoplasms; Female; Flavonoids; Gene Expression Regulation, Neoplastic; Humans; Male; Mice, Nude; Middle Aged; Myeloid Cell Leukemia Sequence 1 Protein; Piperidines; RNA, Small Interfering; Xenograft Model Antitumor Assays

The cyclin-dependent kinase (cdk) inhibitor p27 preferentially inactivates cdk complexes required for progression through the G1/S transition. Loss of p27 is associated with aggressive behavior in a variety of tumors, including Barrett's associated adenocarcinoma (BAA). We have previously shown that gastroduodenal-esophageal reflux (GDER) together with N-methyl-N-benzylnitrosamine (MBN) induces Barrett's esophagus (BE) and malignant transformation of the esophageal mucosa in mice. This process is enhanced in a p27 null background. Here, we show that chronic flavopiridol administration sharply reduced the prevalence of BE in GDER/MBN-treated p27 knockout mice when compared to animals treated with diluent only (7 vs 26%, P=0.0079). Similarly, flavopiridol reduced the prevalence of BAA (11 vs 32%, P=0.0098) and overall cancer prevalence (15 vs 60%, P<0.0001). In addition, appropriate molecular targeting by flavopiridol in tumor cells was confirmed by downregulation of cyclin D1, a known target of this pan-cdk inhibitor. The results of this study represent the experimental basis for chemoprevention with cdk inhibitors in human BE and BAA.

Topics: Adenocarcinoma; Animals; Anticarcinogenic Agents; Barrett Esophagus; Carcinoma, Squamous Cell; Cell Cycle Proteins; Cell Transformation, Neoplastic; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p27; Esophageal Neoplasms; Flavonoids; Mice; Phosphorylation; Piperidines; Retinoblastoma Protein; Tumor Suppressor Proteins

Barrett's esophageal adenocarcinoma (BEAC) is a complication of gastroesophageal reflux disease, with no effective chemotherapy and poor prognosis. BEAC cells, like many other types of cancers, may reactivate telomerase to achieve unlimited proliferative potential, making telomerase a unique therapeutic target. The purpose of this study was to evaluate effects of telomerase inhibition on BEAC.. We examined the effect of a selective G-quadruplex intercalating telomerase inhibitor, 2,6-bis[3-(N-Piperidino)propionamido]anthracene-9,10-dione (PPA), on telomerase activity, telomere length, colony size distribution, and proliferative potential in 2 BEAC cell lines, BIC-1 and SEG-1.. Telomerase activity was >10-fold and >600-fold elevated in the adenocarcinoma cells as compared with normal gastric/intestinal cells and normal diploid fibroblasts, respectively. Telomeres were short, being less than 4 kilobase pair in both tumor cell lines. Exposure to PPA effectively inhibited telomerase activity and shortened telomeres. PPA also arrested cell proliferation and reduced colony number and size after a lag period of about 10 cell generations, consistent with the attrition of telomeres. The growth arrest was not due to senescence but was due to apoptosis. Expression analysis of the cells following PPA treatment did not show significant change in the expression of genes involved in cell-cycle proliferation and apoptosis. Exposure to PPA had no effect on proliferative potential of normal intestinal cells.. We conclude that telomerase inhibition by PPA induces cell growth arrest in BEAC cells and demonstrate the potential of telomerase inhibitors in chemoprevention and treatment of Barrett's-associated esophageal adenocarcinoma.

Topics: Adenocarcinoma; Anthraquinones; Apoptosis; Barrett Esophagus; Cell Division; Cell Line, Tumor; Enzyme Inhibitors; Esophageal Neoplasms; Gene Expression; Gene Expression Profiling; Humans; Piperidines; Stem Cells; Telomerase; Telomere

Topics: Barrett Esophagus; Bethanechol; Cisapride; Gastric Emptying; Gastroesophageal Reflux; Gastrointestinal Agents; Gastrointestinal Motility; Humans; Parasympathomimetics; Piperidines; Proton Pump Inhibitors; Recurrence

Although oesophagitis is the most common diagnosis made at upper gastrointestinal endoscopy, data on the longterm outcome of affected patients are sparse.. This study assessed the level of reflux symptoms, quality of life, drug consumption, and complications in patients at least 10 years after diagnosis of oesophagitis at one centre.. One hundred and fifty two patients with typical reflux symptoms and a first time diagnosis by endoscopy of grade I-III oesophagitis between 1981 and 1984, were followed up using a postal questionnaire and telephone interview.. Eighteen of 152 patients had died, 33 failed to respond, and 101 replied (mean follow up 11 years, range 121-160 months). Over 70% of patients still had heartburn at least daily (32%) or weekly (19%) or required daily acid suppression treatment (20%). Two patients (2%) had developed oesophageal strictures and one had Barrett's oesophagus. Two of eight quality of life scores (physical function and social function) measured by the Short Form-36 were significantly lower than Northern Ireland population scores.. Nearly three quarters of patients previously diagnosed as having oesophagitis still had significant morbidity related to gastro-oesophageal reflux disease more than 10 years after diagnosis. Some quality of life scores were significantly lower than those of the general population.

Topics: Adult; Aged; Aged, 80 and over; Antacids; Barrett Esophagus; Cisapride; Deglutition Disorders; Disease Progression; Esophagitis, Peptic; Female; Follow-Up Studies; Humans; Male; Metoclopramide; Middle Aged; Omeprazole; Piperidines; Quality of Life