Expression of oestrogen receptor β and prognosis of colorectal cancer

BACKGROUND

Previous studies suggest that sex steroids influence colorectal cancer (CRC) carcinogenesis. The oestrogen receptor β (ERβ) is the predominantly expressed ER in the colon and loss of ERβ in CRC has been associated with advanced cancer stages.

METHODS

Information on vital status by the end of 2009 was obtained for 1262 CRC patients recruited between 2003 and 2007. The ERβ expression was immunohistochemically measured and associations of ERβ scores with overall survival (OS), disease-specific survival (DSS) and disease-free survival (DFS) were evaluated using Cox proportional hazard models adjusted for prognostic factors, such as tumour stage and second primary tumours.

RESULTS

Of the 1101 tumour samples with successful measurement, 535 were ERβ negative (48.6%), 381 (34.6%) showed moderate and 185 (16.8%) showed high ERβ expression. Compared with high ERβ expression, lack of ERβ was associated with higher cancer stages as well as greater tumour extent. In multivariate analyses, ERβ negativity was associated with an increased hazard ratio for death (HR=1.61, 95% CI 1.09-2.40, P=0.02), death attributed to CRC (HR=1.54, 95% CI 0.99-2.39, P=0.06) as well as a poorer DFS (DFS HR=1.64, 95% CI 1.23-3.36, P=0.04). The associations were stronger in stage I-III patients (OS HR=2.20, 95% CI 1.28-4.06, P=0.007, DSS HR=2.38, 95% CI 1.20-5.39, P=0.02, respectively).

CONCLUSIONS

Lack of ERβ expression is associated with advanced cancer stages and independently associated with poor survival.

Notch1 signaling promotes survival of glioblastoma cells via EGFR-mediated induction of anti-apoptotic Mcl-1

The Notch1-mediated signaling pathway has a central role in the maintenance of neural stem cells and contributes to growth and progression of glioblastomas, the most frequent malignant brain tumors in adults. Here, we demonstrate that the Notch1 receptor promotes survival of glioblastoma cells by regulation of the anti-apoptotic Mcl-1 protein. Notch1-dependent regulation of Mcl-1 occurs cell type dependent at a transcriptional or post-translational level and is mediated by the induction of epidermal growth factor receptor (EGFR). Inhibition of the Notch1 pathway overcomes apoptosis resistance and sensitizes glioblastoma cells to apoptosis induced by ionizing radiation, the death ligand TRAIL (tumor necrosis factor-related apoptosis-inducing ligand) or the Bcl-2/Bcl-XL inhibitor ABT-737. In conclusion, targeting Notch1 might represent a promising novel strategy in the treatment of glioblastomas.

Cuffed endotracheal tubes in children reduce sevoflurane and medical gas consumption and related costs

BACKGROUND

This study aims to evaluate sevoflurane and anaesthetic gas consumption using uncuffed vs. cuffed endotracheal tubes (ETT) in paediatric surgical patients.

METHODS

Uncuffed or cuffed ETT were used in paediatric patients (newborn to 5 years) undergoing elective surgery in a randomized order. Duration of assessment, lowest possible fresh gas flow (minimal allowed FGF: 0.5 l/min) and sevoflurane concentrations used were recorded. Consumption and costs for sevoflurane and medical gases were calculated.

RESULTS

Seventy children (35 uncuffed ETT/35 cuffed ETT), aged 1.73 (0.01-4.80) years, were enrolled. No significant differences in patient characteristics, study period and sevoflurane concentrations used were found between the two groups. Lowest possible FGF was significantly lower in the cuffed ETT group [1.0 (0.5-1.0) l/min] than in the uncuffed ETT group [2.0 (0.5-4.3) l/min], P<0.001. Sevoflurane consumption per patient was 16.1 (6.4-82.8) ml in the uncuffed ETT group and 6.2 (1.1-14.9) ml in the cuffed ETT group, P=0.003. Medical gas consumption was 129 (53-552) l in the uncuffed ETT group vs. 46 (9-149) l in the cuffed ETT group, P<0.001. The total costs for sevoflurane and medical gases were 13.4 (6.0-67.3)euro/patient in the uncuffed ETT group and 5.2 (1.0-12.5)euro/patient in the cuffed ETT group, P<0.001.

CONCLUSIONS

The use of cuffed ETT in children significantly reduced the costs of sevoflurane and medical gas consumption during anaesthesia. Increased costs for cuffed compared with uncuffed ETT were completely compensated by a reduction in sevoflurane and medical gas consumption.

Adding insulin glargine vs. NPH insulin to metformin results in a more efficient postprandial beta-cell protection in individuals with type 2 diabetes

AIM

Postprandial release of intact proinsulin (IP) is an independent marker for beta-cell dysfunction in patients with type 2 diabetes. This open-label, parallel-group, two-arm, pilot study compared the beta-cell protective effect of adding insulin glargine (GLA) vs. NPH insulin to ongoing metformin.

MATERIAL AND METHODS

Overall, 28 insulin-naive type 2 diabetes subjects (mean +/- SD age, 61.5 +/- 6.7 years; diabetes duration, 9.8 +/- 6.5 years; HbA1c, 7.1 +/- 0.5%; BMI, 30.7 +/- 4.3 kg/m(2)) treated with metformin and sulfonylurea were randomized to add once-daily GLA or NPH at bedtime. At baseline and after 3 months, subjects received a standardized breakfast, lunch and dinner, with pre- and postprandial blood sampling to measure plasma IP, total insulin and blood glucose (BG).

RESULTS

Insulin dose after 3 months was comparable in both groups (GLA vs. NPH: 23.6 +/- 13.4 vs. 23.3 +/- 12.7; p = NS ). Both treatments significantly reduced fasting BG levels (GLA: 158 +/- 19 to 121 +/- 23 mg/dl; NPH: 156 +/- 34 to 119 +/- 29 mg/dl; both p < 0.01 vs. baseline). Fasting and postprandial BG levels did not differ between groups. IP levels decreased in both groups (p < 0.05 at all timepoints). Although IP release after breakfast did not differ between treatments, GLA induced a greater reduction in IP release after lunch (p = 0.08) and dinner (p = 0.04). Total plasma insulin levels did not differ between groups.

CONCLUSIONS

Adding basal insulin to metformin reduces postprandial beta-cell load. While GLA and NPH had comparable effects at breakfast, GLA reduces beta-cell stress more effectively at dinner, and with a trend at lunch, most probably because of its longer lasting pharmacodynamic profile.

Alzheimer's-associated Abeta oligomers show altered structure, immunoreactivity and synaptotoxicity with low doses of oleocanthal

It now appears likely that soluble oligomers of amyloid-beta1-42 peptide, rather than insoluble fibrils, act as the primary neurotoxin in Alzheimer's disease (AD). Consequently, compounds capable of altering the assembly state of these oligomers (referred to as ADDLs) may have potential for AD therapeutics. Phenolic compounds are of particular interest for their ability to disrupt Abeta oligomerization and reduce pathogenicity. This study has focused on oleocanthal (OC), a naturally-occurring phenolic compound found in extra-virgin olive oil. OC increased the immunoreactivity of soluble Abeta species, when assayed with both sequence- and conformation-specific Abeta antibodies, indicating changes in oligomer structure. Analysis of oligomers in the presence of OC showed an upward shift in MW and a ladder-like distribution of SDS-stable ADDL subspecies. In comparison with control ADDLs, oligomers formed in the presence of OC (Abeta-OC) showed equivalent colocalization at synapses but exhibited greater immunofluorescence as a result of increased antibody recognition. The enhanced signal at synapses was not due to increased synaptic binding, as direct detection of fluorescently-labeled ADDLs showed an overall reduction in ADDL signal in the presence of OC. Decreased binding to synapses was accompanied by significantly less synaptic deterioration assayed by drebrin loss. Additionally, treatment with OC improved antibody clearance of ADDLs. These results indicate oleocanthal is capable of altering the oligomerization state of ADDLs while protecting neurons from the synaptopathological effects of ADDLs and suggest OC as a lead compound for development in AD therapeutics.

Functional characterisation of decoy receptor 3 in Crohn's disease

AIMS

Both epithelial barrier dysfunction and apoptosis resistance of immune cells contribute to the pathogenesis of Crohn's disease. The soluble decoy receptor 3 (DcR3) acts in an anti-apoptotic manner by neutralising the death ligand CD95L. Here, we investigated the possible involvement of DcR3 in Crohn's disease.

METHODS

The epithelial fraction of human small intestinal mucosa samples was obtained by laser microdissection. Expression of DcR3 was examined by global gene expression profiling, quantitative reverse transcription polymerase chain reaction, immunoblot analysis, and immunohistochemistry. DcR3 concentrations in the serum of patients with Crohn's disease were measured by enzyme-linked immunosorbent assay. Apoptosis assays were performed to study the effects of DcR3 in intestinal epithelial cells and lamina propria T cells.

RESULTS

DcR3 is over-expressed in the epithelial layer of ileum specimens in patients with Crohn's disease, both at actively inflamed and non-active sites. DcR3 serum levels are significantly elevated in patients with active and non-active Crohn's disease as compared to healthy controls. The expression of DcR3 in intestinal epithelial cells is induced by tumour necrosis factor alpha. Increased DcR3 expression is associated with activation of nuclear factor kappa B (NF-kappaB) and results in protection of intestinal epithelial cells and lamina propria T cells from CD95L-induced apoptosis.

CONCLUSIONS

DcR3 may promote inflammation in Crohn's disease by inhibiting CD95L-induced apoptosis of epithelial and immune cells as well as by inducing NF-kappaB activation.

[Procedural analgesia : concepts and practice]

The effect of severe pain and its hazardous stress-related cardiocirculatory consequences have been well documented for the perisurgical setting. Independently of surgical intervention however, even short and simple measures (e.g. thorax drain removal, repositioning a limb fracture) and longer diagnostic procedures such as MRI are potentially very painful or stressful to the patient. Though longer diagnostic procedures are frequently supported by systemic medication, short interventions regularly lack this aspect. Specific challenges result from the need to counteract sometimes great changes in pain intensity. Moreover procedural analgesia represents a multidisciplinary measure not restricted to anaesthesiology, as most of these measures are performed without anaesthesia. To avoid endangering the patient, the choice of drugs and patient monitoring have to meet certain professional and technical standards. Competence in respiratory management is of paramount importance. This paper outlines these requirements and serves as an orientation outside the anaesthesiological speciality.

The PEA-15/PED protein protects glioblastoma cells from glucose deprivation-induced apoptosis via the ERK/MAP kinase pathway

PEA-15 (phosphoprotein enriched in astrocytes 15 kDa) is a death effector domain-containing protein, which is involved in the regulation of apoptotic cell death. Since PEA-15 is highly expressed in cells of glial origin, we studied the role of PEA-15 in human malignant brain tumors. Immunohistochemical analysis of PEA-15 expression shows strong immunoreactivity in astrocytomas and glioblastomas. Phosphorylation of PEA-15 at Ser(116) is found in vivo in perinecrotic areas in glioblastomas and in vitro after glucose deprivation of glioblastoma cells. Overexpression of PEA-15 induces a marked resistance against glucose deprivation-induced apoptosis, whereas small interfering RNA (siRNA)-mediated downregulation of endogenous PEA-15 results in the sensitization to glucose withdrawal-mediated cell death. This antiapoptotic activity of PEA-15 under low glucose conditions depends on its phosphorylation at Ser(116). Moreover, siRNA-mediated knockdown of PEA-15 abolishes the tumorigenicity of U87MG glioblastoma cells in vivo. PEA-15 regulates the level of phosphorylated extracellular-regulated kinase (ERK)1/2 in glioblastoma cells and the PEA-15-dependent protection from glucose deprivation-induced cell death requires ERK1/2 signaling. PEA-15 transcriptionally upregulates the Glucose Transporter 3, which is abrogated by the inhibition of ERK1/2 phosphorylation. Taken together, our findings suggest that Ser(116)-phosphorylated PEA-15 renders glioma cells resistant to glucose deprivation-mediated cell death as encountered in poor microenvironments, for example in perinecrotic areas of glioblastomas.

[The anti-diabetic drug troglitazone sensitizes colon cancer cells to TRAIL-induced apoptosis by down-regulating FLIP]

AIMS

Induction of apoptosis by the death ligand TRAIL might be a promising therapeutic approach in colorectal cancer therapy. However, some colon cancer cells are resistant to TRAIL because of the expression of anti-apoptotic proteins, such as FLIP. We studied the role of FLIP for apoptosis resistance in colon cancer and developed an approach to overcome the resistance to TRAIL.

METHODS

The mechanisms of TRAIL-induced cell death in colon cancer cells were studied by Western blot analysis, apoptosis assays, transient and stable transfections, siRNA-mediated knockdown, and FACS analysis.

RESULTS

The anti-apoptotic protein FLIP is expressed in the majority of colon carcinoma. Stable over-expression of FLIP renders colon carcinoma cells resistant to the death ligand, TRAIL. siRNA-mediated down-regulation of FLIP sensitizes the cells to TRAIL-induced apoptosis. FLIP-expressing colon cancer cells can be sensitized to TRAIL-induced apoptosis by the anti-diabetic drug troglitazone. Troglitazone induces a pronounced reduction in protein expression levels of FLIP. The troglitazone-dependent down-regulation of FLIP occurs on a post-translational level and involves the accelerated FLIP degradation by the proteasome. Moreover, troglitazone suppresses the expression of the anti-apoptotic protein, survivin, and induces the cell surface expression of the TRAIL receptor 2.

CONCLUSIONS

The anti-apoptotic FLIP protein plays an important role in apoptosis resistance of colon carcinoma cells. Troglitazone down-regulates FLIP and sensitizes the cells to TRAIL-induced apoptosis. A combined treatment with troglitazone and TRAIL might be a promising experimental therapy for some forms of colorectal cancer because troglitazone sensitizes tumor cells to TRAIL-induced apoptosis via various mechanisms, thereby minimizing the risk of acquired tumor cell resistance.

[The PEA-15 protein induces resistance against glucose deprivation-induced cell death via the ERK/MAP kinase pathway]

PEA-15 (Phosphoprotein enriched in astrocytes 15 kD) is a death effector domain-containing protein, which is involved in the regulation of apoptotic cell death. Since PEA-15 is highly expressed in cells of glial origin, we studied the role of PEA-15 in human malignant brain tumors. Immunohistochemical analysis of PEA-15 expression shows strong immunoreactivity in astrocytomas and glioblastomas. Phosphorylation of PEA-15 at Ser116 is found in vivo in perinecrotic areas in glioblastomas and in vitro after glucose deprivation of glioblastoma cells. Overexpression of PEA-15 induces a marked resistance against glucose deprivation-induced apoptosis, whereas siRNA-mediated down-regulation of endogenous PEA-15 results in the sensitization to glucose withdrawal-mediated cell death. This anti-apoptotic activity of PEA-15 under low glucose conditions depends on its phosphorylation at Ser116 Moreover, siRNA-mediated knockdown of PEA-15 abolishes the tumorigenicity of U87MG glioblastoma cells in vivo. PEA-15 regulates the level of phosphorylated ERK1/2 in glioblastoma cells and the PEA-15-dependent protection from glucose deprivation-induced cell death requires ERK1/2 signaling. PEA-15 transcriptionally up-regulates the glucose transporter 3, which is abrogated by the inhibition of ERK1/2 phosphorylation. Taken together, our findings suggest that Ser116-phosphorylated PEA-15 renders glioma cells resistant to glucose deprivation-mediated cell death as encountered in poor microenvironments, e.g. in perinecrotic areas of glioblastomas.

[Minimally invasive adrenalectomy for pheochromocytoma: routine or risk?]

BACKGROUND

As a result of intraoperative catecholamine secretion with hemodynamic changes, larger tumor size, and marked neovascularization, adrenalectomy is more challenging and prone to complications for pheochromocytoma than for other adrenal diseases. The aim of this study was to examine the relative intraoperative risk of cardiovascular complications with the minimally invasive approach.

PATIENTS AND METHODS

Between February 1992 and May 2005, 82 operations were performed on 71 pheochromocytoma patients at our clinic. Of them, nine adrenalectomies were bilateral, one was trilateral, and two patients had recurrent procedures. Another five patients were included whose first operations took place before 1992. Thirty-six procedures were carried out conventionally (35 transperitoneally, one retroperitoneally) and 46 were endoscopic (28 transperitoneally, 18 retroperitoneally). There was no conversion to open procedure.

RESULTS

The median age at the time of surgery was 45 (24-75) years, and the median history of symptoms was 12 months (0-180). The openly resected pheochromocytomas were significantly larger than those in endoscopic operations: 5.5 cm (1-19 cm) vs 3.5 cm (0.5-8 cm) (P=0.0011). Compared with patients undergoing conventional procedures, those operated on endoscopically showed higher intraoperative systolic and diastolic blood pressures and peaks of more than 200 mmHg, although these differences were statistically insignificant. Multivariate analysis identified gender (P=0.0107), operative approach (P=0.0153), age (P=0.0364), and tumor size (P=0.0484) as factors with a possible influence on intraoperative hemodynamic alterations. Postoperative hospital stay was significantly shorter following endoscopic adrenalectomy (P=0.0001).

CONCLUSION

Endoscopic adrenalectomy for pheochromocytoma is suitable as a routine operation and harbors no increased risk of cardiovascular complications, making it the method of choice. The open procedure should be reserved for extraadrenal tumors or large tumors with the suspicion of malignancy.