Lifetime risk of esophageal adenocarcinoma in patients with Barrett's esophagus.

AIM: To investigate the lifetime risk of development of esophageal adenocarcinoma and/or high-grade dysplasia in patients diagnosed with Barrett's esophagus. METHODS: Data were extracted from the United Kingdom National Barrett's Oesophagus Registry on date of diagnosis, patient age and gender of 7877 patients from who had been registered from 35 United Kingdom centers. Life expectancy was evaluated from United Kingdom National Statistics data based upon gender and age at year at diagnosis. These data were then used with published estimates of annual adenocarcinoma and high-grade dysplasia incidences from meta-analyses and large population-based studies to estimate overall lifetime risk of development of these study endpoints. RESULTS: The mean age at diagnosis of Barrett's esophagus was 61.6 years in males and 67.3 years in females. The mean life expectancy at diagnosis was 23.1 years in males, 20.7 years in females and 22.2 years overall. Using data from published meta-analyses, the lifetime risk of development of adenocarcinoma was between 1 in 8 and 1 in 14 and the lifetime risk of high-grade dysplasia or adenocarcinoma was 1 in 5 to 1 in 6. Using data from 3 large recent population-based cohort studies the lifetime risk of adenocarcinoma was between 1 in 10 and 1 in 37 and of the combined end-point of high-grade dysplasia and adenocarcinoma was between 1 in 8 and 1 in 20. Age at Barrett's esophagus diagnosis is reducing and life expectancy is increasing, which will partially counter-balance lower annual cancer incidence. CONCLUSION: There is a significant lifetime risk of development of high-grade dysplasia and adenocarcinoma in Barrett's esophagus.

Post-surgical chemotherapy versus surgery alone for resectable gastric cancer.

BACKGROUND: For gastric cancer surgery is the mainstay treatment. Chemotherapy seems to improve the survival results. But chemotherapy is not a complication-free therapy and its role has been questioned by some trials. OBJECTIVES: To determine whether post-surgical chemotherapy should be used routinely in resectable gastric cancer. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded (July 2013). SELECTION CRITERIA: Randomised controlled trials (RCT) comparing post-surgical chemotherapy versus surgery alone for resectable gastric cancer. DATA COLLECTION AND ANALYSIS: Two authors independently assessed trials for inclusion and independently extracted the data. We analysed the data with both the fixed-effect and the random-effects models using the RevMan analysis software. We calculated the hazard ratio (HR) with 95% confidence interval (CI) based on intention-to-treat or available case analysis. MAIN RESULTS: The authors identified 34 studies (7824 patients) reporting overall survival (OS) and only 15 reporting disease free survival (DFS) as well. Post-surgical chemotherapy showed an improvement in OS (HR 0.85; 95% CI 0.80 to 0.90) and an improvement in DFS (HR 0.79; 95% CI 0.72 to 0.87), although all the trials had a high risk of bias.The planned analysis of quality of life, return to work, and number of hospital admissions was impossible to complete as the outcome data for the analysis were not available from any trials. AUTHORS' CONCLUSIONS: Post-surgical chemotherapy should be used routinely for resectable gastric cancer where possible. Further RCTs are needed to determine the role at each stage of disease.

Cyclooxygenase/lipoxygenase shunting lowers the anti-cancer effect of cyclooxygenase-2 inhibition in colorectal cancer cells.

BACKGROUND: Arachidonic acid metabolite, generated by cyclooxygenase (COX), is implicated in the colorectal cancer (CRC) pathogenesis. Inhibiting COX may therefore have anti-carcinogenic effects. Results from use of non-steroidal anti-inflammatory drugs inhibiting only COX have been conflicting. It has been postulated that this might result from the shunting of arachidonic acid metabolism to the 5-lipoxygenase (5-LOX) pathway. Cancer cell viability is promoted by 5-LOX through several mechanisms that are similar to those of cyclooxygenase-2 (COX-2). Expression of 5-LOX is upregulated in colorectal adenoma and cancer. The aim of this study was to investigate the shunting of arachidonic acid metabolism to the 5-LOX pathway by cyclooxygenase inhibition and to determine if this process antagonizes the anti-cancer effect in colorectal cancer cells. METHODS: Three colorectal cancer cell lines (HCA7, HT-29 & LoVo) expressing 5-LOX and different levels of COX-2 expression were used. The effects of aspirin (a non-selective COX inhibitor) and rofecoxib (COX-2 selective) on prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) secretion were quantified by ELISA. Proliferation and viability were studied by quantifying double-stranded DNA (dsDNA) content and metabolic activity. Apoptosis was determined by annexin V and propidium iodide staining using confocal microscopy, and caspase-3/7 activity by fluorescent substrate assay. RESULTS: COX inhibitors suppressed PGE2 production but enhanced LTB4 secretion in COX-2 expressing cell lines (P <0.001). The level of COX-2 expression in colorectal cancer cells did not significantly influence the anti-proliferative and pro-apoptotic effects of COX inhibitors due to the shunting mechanism. CONCLUSIONS: This study provides evidence of shunting between COX and 5-LOX pathways in the presence of unilateral inhibition, and may explain the conflicting anti-carcinogenic effects reported with use of COX inhibitors.

The relationship between smoking and severe dysplastic disease in patients with Barrett's columnar-lined oesophagus.

The aim of this study was to examine the relationship between smoking and oesophageal high-grade dysplasia (HGD) or adenocarcinoma (AC) in a large cohort of patients with Barrett's columnar-lined oesophagus (CLO). A total of 1280 patients diagnosed with CLO and registered with the UK National Barrett's Oesophagus Registry were included. Data, including smoking habits, were collected from the patient's notes and development of HGD or AC noted. Analysis was performed with SPSS using logistic regression for calculation of odds ratios (ORs) for development of HGD/AC. Data on smoking habits were available in 956 (74.6%) patients. There was no significant difference between smokers and nonsmokers in mean age (P=0.877) or length of follow-up (P=0.359). There was a significant risk of HGD/AC in patients with any history of smoking compared with those who had never smoked (P<0.001, OR 2.81). Ex-smokers of 10 years or more remained at a significantly higher risk of HGD/AC compared with those who had never smoked (P=0.001, OR 3.37). Current smokers were not at a significantly higher risk of HGD/AC compared with ex-smokers (P=0.857) nor were those who smoked at least 20 a day compared with those who smoked fewer than 20 a day (P=0.632). In patients with CLO, smoking appears to be a significant risk factor for the development of severe dysplastic disease; however, we did not observe a dose-dependent effect of smoking on progression of disease.

Endothelin-1 stimulates colon cancer adjacent fibroblasts.

Endothelin-1 (ET-1) is produced by and stimulates colorectal cancer cells. Fibroblasts produce tumour stroma required for cancer development. We investigated whether ET-1 stimulated processes involved in tumour stroma production by colonic fibroblasts. Primary human fibroblasts, isolated from normal tissues adjacent to colon cancers, were cultured with or without ET-1 and its antagonists. Cellular proliferation, migration and contraction were measured. Expression of enzymes involved in tumour stroma development and alterations in gene transcription were determined by Western blotting and genome microarrays. ET-1 stimulated proliferation, contraction and migration (p < 0.01 v control) and the expression of matrix degrading enzymes TIMP-1 and MMP-2, but not MMP-3. ET-1 upregulated genes for profibrotic growth factors and receptors, signalling molecules, actin modulators and extracellular matrix components. ET-1 stimulated colonic fibroblast cellular processes in vitro that are involved in developing tumour stroma. Upregulated genes were consistent with these processes. By acting as a strong stimulus for tumour stroma creation, ET-1 is proposed as a target for adjuvant cancer therapy.

Barrett's, blood groups and progression to oesophageal cancer: is nitric oxide the link?

INTRODUCTION: Incidence of oesophageal adenocarcinoma (OAC) is increasing rapidly. OAC arises in columnar-lined oesophagus (CLO), a metaplastic change affecting some patients with gastro-oesophageal reflux disease (GORD). As yet there is no reliable method of identifying those at highest risk. Our earlier observation of an association between OAC and blood group O Rhesus negative, if confirmed, may help identify those at greatest risk. AIM AND METHODS: To assess the distribution of blood group and Rhesus D (RhD) factor in patients with GORD compared with the blood donating general population. GORD was categorized as nonerosive reflux (NER), erosive oesophagitis, CLO and OAC. The Rotherham Hospital database holds details of all GORD, CLO and OAC patients seen in the Gastroenterology Unit. Blood group information for patients with GORD was obtained from patients' records and the hospital's blood transfusion service. The blood group distribution in the general population was obtained from the National Blood Transfusion Service. The number of expected to observed patients in each blood group for each subtype was compared. RESULTS: Two thousand six hundred and ten NER, 2813 erosive oesophagitis, 568 CLO and 73 OAC patients had a recorded blood group. For RhD positive patients observed proportions in each blood group were similar to expected. The most striking difference was the marked excess of OAC in blood group O, Rhesus negative (P=0.002). CONCLUSION: CLO patients with blood group O, RhD negative carry a disproportionately higher risk of developing OAC. The mechanism is unknown but the finding has practical application in guiding risk stratification and intensity of surveillance.

Projections for oesophageal cancer incidence in England to 2033.

The United Kingdom has the highest age-standardized incidence of oesophageal cancer in Europe. This study projects the number of cases of oesophageal cancer arising in England over a 25-year period. Data from National Statistics were used to determine the number and incidence of oesophageal cancers diagnosed during 2001-2007 (separated by age and sex). These data were used with population projections to model the number of cancers that would develop in the future. Variant estimates were undertaken with high/low rates of migration and life expectancy and by varying the rate of change in the incidence of oesophageal cancer. The principal projection showed that, compared with the 2007 baseline, the number of oesophageal cancers in men is predicted to rise by 20% by 2014 and by 40% by 2020. In women, after an initial predicted decline, the number of cancers is predicted to rise above the 2007 baseline by 2012 and to be 5% higher by 2023. The variant projections showed that only a small effect was likely to be caused by changes in net migration (<1% change by 2030) and life expectancy (1% change by 2020). The effect of a 1% increase or decrease in the rate of change of incidence had a more marked effect (10% change by 2017 or 2018). None of the modelled scenarios resulted in an overall decrease in the number of projected cases because of the change in population demographics. The number of cases of oesophageal cancer in England is likely to continue to increase.

Inhibition of the p38 MAPK pathway sensitises human colon cancer cells to 5-fluorouracil treatment.

Colorectal cancer is the third most common cause of cancer-related deaths in the Western world. 5-Fluorouracil (5-FU) based chemotherapeutic regimes have been the mainstay of systemic treatment for disseminated colorectal cancer for many years. However, it only produces a 25% response rate due to the drug-resistance. The mitogen-activated protein kinase (MAPK) pathway is involved in the anti-apoptotic process; its activation provides cancer cells with a survival advantage to escape the apoptotic challenge. This study assessed whether the p38 MAPK pathway is involved in 5-FU resistance in colorectal cancer cells. 5-FU only or 5-FU combined with a p38 MAPK pathway inhibitor (SB203580) was used to treat 5-FU-resistant colorectal cancer cells. The effect of the treatment on cell viability, death and caspase activities was assessed. Western blotting was used to investigate the responses of apoptosis-related proteins following the treatment. Results showed that p38 MAPK inhibitor significantly increased colorectal cancer cell sensitivity to 5-FU. SB203580 in combination with 5-FU significantly reduced cell viability (P<0.01), and increased cell death and cellular caspase activity (P<0.01). Western blotting data revealed that SB203580 sensitises cancer cells to 5-FU due to an increase in Bax expression. These findings suggest that p38 MAPK is involved in cancer cell survival, and that the inhibition of p38 MAPK can enhance 5-FU to kill colorectal cancer cells.

Growth Factors and their receptors in cancer metastases.

Metastatic, rather than primary tumours are responsible for ninety percent cancer deaths. Despite significant advances in the understanding of molecular and cellular mechanisms in tumour metastases, there are limitations in preventive treatment of metastatic tumours. Much evidence arising from laboratory and clinical studies suggests that growth factors and their receptors are implicated in cancer metastases development. We review the origin and production of growth factors and their receptors in all stages of cancer metastases including epithelial-mesenchymal transition, cancer cell invasion and migration, survival within the circulation, seeding at distant organs and metastatic tumour angiogenesis. The functions of growth factors and their receptors are also discussed. This review presents the efforts made in understanding this challenge to aid in the development of new treatment strategies for cancer metastases.

Lowering the apoptotic threshold in colorectal cancer cells by targeting mitochondria.

BACKGROUND: Colorectal cancer is the third most-common cancer and the second most-common cause of cancer related death in UK. Although chemotherapy plays significant role in the treatment of colorectal cancer, morbidity and mortality due to drug resistance and cancer metastasis are yet to be eliminated. Recently, doxycycline has been reported to have cytotoxic and anti-proliferating properties in various cancer cells. In this study, whether doxycycline was apoptosis threshold lowering agent in colorectal cancer cells by targeting mitochondria was answered. RESULTS: This study showed dose-dependent cytotoxic effects of cisplatin, oxaliplatin and doxycycline in HT29 colorectal cancer cells. Doxycycline showed inhibition of cytochrome-c-oxidase activity in these cells over a time-period. The pre-treatment of doxycycline reported statistically significant increased cytotoxicity of cisplatin and oxaliplatin compared to cisplatin and oxaliplatin alone. The caspase studies revealed significantly less expression and activity of caspase 3 in HT29 cells pre-treated with doxycycline compared to the cells treated with cisplatin and oxaliplatin alone. CONCLUSIONS: It was concluded that doxycycline lowered the apoptotic threshold in HT 29 cells by targeting mitochondria. This also raised possible caspase-independent mechanisms of apoptosis in HT29 cells when pre-treated with doxycycline however this needs further research work.

In vivo factors influencing tumour M2-pyruvate kinase level in human pancreatic cancer cell lines.

In tumour cells, the tetramer/dimer ratio of the pyruvate kinase isoenzyme type M2 (M2-PK) determines whether glucose carbons are degraded to lactate with production of energy (tetrameric form) or are channelled into synthetic processes (dimeric form). The influence of different tumour microenvironment conditions on the tetramer/dimer ratio of M2-PK and cell doublings were investigated in a non-metastatic and metastatic pancreatic cancer cell line. The metastatic Colo357 cells contained about fourfold more M2-PK protein and about 3.5-fold more dimeric M2-PK than the non-metastatic Panc-1 cells. In Colo357 cells hypoxia, glucose starvation as well as acidification induced an increase of the dimeric form of M2-PK, whereas in Panc-1 cells no effect on M2-PK was observed. Under hypoxia in Colo357 cells, the dimerization and inactivation of M2-PK results in an inhibition of cell proliferation, whereas under glucose starvation and acidification the dimerization of M2-PK allowed further cell doublings. M2-PK expression and the quaternary structure of M2-PK are influenced by the tumour metastatic potential. The quaternary structure of M2-PK may be differently affected by hypoxia, glucose starvation and acidification with severe consequences on cell doublings.

Pretreatment with insulin-like growth factor I protects skeletal muscle cells against oxidative damage via PI3K/Akt and ERK1/2 MAPK pathways.

Oxidative stress has an important role in the pathogenesis of many muscle diseases. The major contributors to oxidative stress in muscle tissue are reactive oxygen species such as oxygen ions, free radicals, and peroxides. Insulin-like growth factor I (IGF-I) has been shown to increase muscle mass and promote muscle cell proliferation, differentiation, and survival. We, therefore, hypothesized that IGF-I might also be cytoprotective for muscle cells during oxidative stress. Exogenous hydrogen peroxide (H(2)O(2)) was used to induce oxidative stress/damage in two types of skeletal muscle cells. Apoptotic pathways were assessed after the oxidative damage and the effects of IGF-I on oxidative stress in muscle cells were examined. Different IGF-I sub-pathways were analyzed with measurement of the expression of pro-and anti-apoptotic proteins. It was found that H(2)O(2) diminishes muscle cell viability and induces a caspase-independent apoptotic cell death. Pretreatment with IGF-I protects muscle cells from H(2)O(2)-induced cell death and enhances muscle cells survival. This effect appears to result from the promotion of the anti-apoptotic protein, Bcl2. Further investigation shows that protection is via an IGF-I sub-pathway: PI3K/Akt and ERK1/2 MAPK pathways. Protecting muscle cells from oxidative damage presents a potential application in the treatment of the muscle wasting, which appears in many muscle pathologies including Duchenne muscle dystrophy and sarcopenia.

Ischemic preconditioning of small bowel mitigates the late phase of reperfusion injury: heme oxygenase mediates cytoprotection.

BACKGROUND: Ischemia and reperfusion (IR) injury of the intestine is a major cause of morbidity and mortality following small bowel transplantation. The current study evaluates the effect of ischemic preconditioning (IPC) on the intestinal microcirculation in the late phase of IR injury of the intestine. METHODS: Sixty rats were randomly allocated to 5 study groups (n = 12 per group): (1) sham, (2) IR (3) IPC, (4) pyrrolidine dithiocarbamate (PDTC) (HO-1 inducer), and (5) zinc protoporhyrin (ZnPP) (HO-1 inhibitor). Mucosal perfusion and leukocyte-endothelial interactions were measured with the aid of an intravital microscope. At the end of the experiments, blood samples for lactate dehydrogenase (LDH) levels and biopsies of ileum for histologic evaluation were obtained. RESULTS: IPC significantly improved the mucosal perfusion and decreased the leukocyte-endothelial interactions. Histologic examination showed that ileal mucosa was significantly less injured in the IPC and PDTC groups as compared with the IR group. CONCLUSIONS: IPC protects the intestine from late reperfusion injury. HO-1 is involved in this protection. These findings may be of significant importance in clinical small bowel transplantation.

[The role of insulin-like growth factors (IGF) in cell division processes and in malignancy]. / Az inzulinszeru növekedési faktor (IGF) szerepe a sejtosztódási folyamatokban és a daganatokban.

Extensive research is being carried out to identify the role of insulin-like growth factor (IGF) in cellular development and tumorigenesis. There is substantial experimental and clinical evidence now that IGF and the related signalling pathways have important roles in regulating cellular proliferation, promoting cellular differentiation and anti-apoptotic effect. Significant amount of IGF is produced locally by neoplastic tissue, which gets into the circulation and adds to the naturally liver-generated and circulating amount. The IGF binding proteins (IGFBP) modulate the bioavailability of IGFs. Upon ligand binding to the receptor, the intrinsic tyrosine kinase activity initiates the phosphatidylinositol-3-kinase (PI3-K) and p38 mitogen activated protein kinase (MAPK) pathway; these have a summon effect on cell cycle. The ligand and the receptor biosynthesis are reviewed, as well as the signal transduction system and the IGF' role in neoplasm. Finally, the therapeutic modalities are surveyed with the preclinical drug's main features.

Growth factors enhance endothelial progenitor cell proliferation under high-glucose conditions.

BACKGROUND: The purpose of this study was to investigate the impact of growth regulators, including growth hormone (GH), insulin-like growth factor 1 (IGF-1), and mechano growth factor (MGF), on endothelial progenitor cell (EPC) proliferation at different glucose concentrations. MATERIAL/METHODS: EPCs were isolated and cultured from peripheral blood samples of healthy volunteers and immunocytochemically characterized after 7 days. The effects of glucose and growth regulators on EPC proliferation were determined with the Alamar Blue and Trypan Blue assays. The effect of glucose supplementation at 2.5, 11.1, and 25.0 mM was examined using cells seeded at densities of 15000, 30000, and 45000 cells/ml. RESULTS: For the GH-treated cells, enhancement of EPC proliferation was detected in the samples supplemented with 11.1 and 25.0 mM glucose. A slight elevation in EPC proliferation was only observed in the IGF-1-treated cells supplemented with 25.0 mM glucose. Significant enhancement of EPC proliferation was observed in MGF-treated cells supplemented with 11.1 and 25.0 mM glucose. All three growth factors demonstrated enhancement of cellular proliferation when the cells were supplemented with 25.0 mM glucose. No enhancement of EPC proliferation by the growth factors was detected in any of the cells supplemented with 2.5 mM glucose. CONCLUSIONS: GH, IGF-1, and MGF enhance EPC proliferation under 25.0 mM glucose conditions. The presence of these growth regulators in EPC culture may contribute to protecting EPCs from high-glucose conditions. This action may be of therapeutic relevance contributing to beneficial cardiovascular effects for diabetic patient.

In vitro small intestinal epithelial cell growth on a nanocomposite polycaprolactone scaffold.

Tissue engineering of the small intestine remains experimental despite worldwide attempts to develop a functional substitute for short bowel syndrome. Most published studies have reported predominant use of PLLA (poly-L-lactide acid)/PGA (polyglycolic acid) copolymer as the scaffold material, and studies have been limited by in vivo experiments. This lack of progress has inspired a fresh perspective and provoked further investigation and development in this field of tissue engineering. In the present paper, we exploit a relatively new nanocomposite of POSS (polyhedral oligomeric silsesquioxane) and PCL [poly(caprolactone-urea)urethane] as a material to develop porous scaffolds using a solvent casting/particulate leaching technique to fabricate porous scaffolds in different pore sizes and porosities. Scaffolds were characterized for pore morphology and porosity using scanning electron microscopy and micro-computed tomography. Rat intestinal epithelial cells were then seeded on to the polymer scaffolds for an in vitro study of cell compatibility and proliferation, which was assessed by Alamar Blue and lactate dehydrogenase assays performed for 21 days post-seeding. The results obtained demonstrate that POSS-PCL nanocomposite was produced as a macroporous scaffold with porosity over the range of 40-80% and pore size over the range of 150-250 microm. This scaffold was shown to support epithelial cell proliferation and growth. In conclusion, as a further step in investigating small intestinal tissue engineering, the nanocomposite employed in this study may prove to be a useful alternative to poly(lactic-co-glycolic acid) in the future.

Routinely diagnosed low-grade dysplasia in Barrett's oesophagus: a population-based study of natural history.

AIMS: To examine the natural history of columnar-lined oesophagus with routinely diagnosed low-grade dysplasia and ascertain the risk of oesophageal adenocarcinoma development. METHODS AND RESULTS: A multicentre retrospective cohort study of 283 patients with low-grade dysplasia. Follow-up data were obtained from examination of hospital records. One hundred and forty-four patients had biopsies prior to low-grade dysplasia diagnosis and 217 had follow-up biopsies after index low-grade dysplasia diagnosis. In these patients the incidence of high-grade dysplasia and adenocarcinoma combined was 4.6% per annum and of adenocarcinoma alone was 2.7% per annum. At most recent follow-up, 43 (19.8%) had persistent low-grade dysplasia, 37 (17.1%) had changes indefinite for dysplasia and 108 (49.8%) had non-dysplastic columnar-lined oesophagus. When prevalent cases were excluded (those occurring within 1 year of index low-grade dysplasia diagnosis), the annual incidence of high-grade dysplasia and adenocarcinoma combined was 2.2% and of adenocarcinoma alone was 1.4%. The relative risk for adenocarcinoma development in low-grade dysplasia compared with non-dysplastic columnar-lined oesophagus was 2.871 (P = 0.002). CONCLUSIONS: Low-grade dysplasia has a threefold increased risk of progression to cancer compared with non-dysplastic epithelium, but in the majority of patients dysplasia is not subsequently detected.