Therapeutic potential of NADPH oxidase 1/4 inhibitors.

The NADPH oxidase (NOX) family of enzymes produces ROS as their sole function and is becoming recognized as key modulators of signal transduction pathways with a physiological role under acute stress and a pathological role after excessive activation under chronic stress. The seven isoforms differ in their regulation, tissue and subcellular localization and ROS products. The most studied are NOX1, 2 and 4. Genetic deletion of NOX1 and 4, in contrast to NOX2, has revealed no significant spontaneous pathologies and a pathogenic relevance of both NOX1 and 4 across multiple organs in a wide range of diseases and in particular inflammatory and fibrotic diseases. This has stimulated interest in NOX inhibitors for therapeutic application. GKT136901 and GKT137831 are two structurally related compounds demonstrating a preferential inhibition of NOX1 and 4 that have suitable properties for in vivo studies and have consequently been evaluated across a range of disease models and compared with gene deletion. In contrast to gene deletion, these inhibitors do not completely suppress ROS production, maintaining some basal level of ROS. Despite this and consistent with most gene deletion studies, these inhibitors are well tolerated and slow or prevent disease progression in a range of models of chronic inflammatory and fibrotic diseases by modulating common signal transduction pathways. Clinical trials in patients with GKT137831 have demonstrated excellent tolerability and reduction of various markers of chronic inflammation. NOX1/4 inhibition may provide a safe and effective therapeutic strategy for a range of inflammatory and fibrotic diseases. LINKED ARTICLES: This article is part of a themed section on Redox Biology and Oxidative Stress in Health and Disease. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.12/issuetoc.

The NADPH oxidase NOX5 protects against apoptosis in ALK-positive anaplastic large-cell lymphoma cell lines.

Reactive oxygen species (ROS) are key modulators of apoptosis and carcinogenesis. One of the important sources of ROS is NADPH oxidases (NOXs). The isoform NOX5 is highly expressed in lymphoid tissues, but it has not been detected in any common Hodgkin or non-Hodgkin lymphoma cell lines. In diverse, nonlymphoid malignant cells NOX5 exerts an antiapoptotic effect. Apoptosis suppression is the hallmark feature of a rare type of lymphoma, termed anaplastic lymphoma kinase-positive (ALK(+)) anaplastic large-cell lymphoma (ALCL), and a major factor in the therapy resistance and relapse of ALK(+) ALCL tumors. We applied RT-PCR and Western blot analysis to detect NOX5 expression in three ALK(+) ALCL cell lines (Karpas-299, SR-786, SUP-M2). We investigated the role of NOX5 in apoptosis by small-interfering RNA (siRNA)-mediated gene silencing and chemical inhibition of NOX5 using FACS analysis and examining caspase 3 cleavage in Karpas-299 cells. We used immunohistochemistry to detect NOX5 in ALK(+) ALCL pediatric tumors. NOX5 mRNA was uniquely detected in ALK(+) ALCL cells, whereas cell lines of other lymphoma classes were devoid of NOX5. Transfection of NOX5-specific siRNA and chemical inhibition of NOX5 abrogated calcium-induced superoxide production and increased caspase 3-mediated apoptosis in Karpas-299 cells. Immunohistochemistry revealed focal NOX5 reactivity in pediatric ALK(+) ALCL tumor cells. These results indicate that NOX5-derived ROS contribute to apoptosis blockage in ALK(+) ALCL cell lines and suggest NOX5 as a potential pharmaceutical target to enhance apoptosis and thus to suppress tumor progression and prevent relapse in pediatric ALK(+) ALCL patients that resist classical therapeutic approaches.

An interesting case of a pituitary adenoma apoplexy mimicking an acute meningitis. Case report.

Apoplexy of a pituitary adenoma is a rare and under-diagnosed clinical occurrence. It results from either infarction or haemorrhage into an adenoma of the pituitary gland. Its clinical presentation more often includes rapid development of impaired consciousness, severe headache, visual disturbance and variable association of oculomotor nerve palsy. Meningeal irritation signs are considered very rare and usually not reported as presenting symptoms. A 33-year-old male suffered a pituitary macroadenoma apoplexy, clinically indistinguishable from an infectious meningitis at presentation. Three days after surgery, the patient developed a left ophthalmoplegia due to 3(rd) nerve palsy, which fully resolved within 2 months. A right pterional craniotomy was performed during which complete tumour removal was achieved. In conclusion the authors believe that, despite many reports in the literature, encouraging conservative management in pituitary apoplexy by administering intravenous steroids, surgery should be undertaken in order to avoid eventual visual field defects, relieve pituitary gland compression and prevent a possible recurrent apoplectic episode or tumor re-growth.

Anterior cervical corpectomy for cervical spondylotic myelopathy: experience and surgical results in a series of 70 consecutive patients.

Recently the debate over the management of cervical spondylotic myelopathy (CSM) has regained interest; more specifically whether treatment should be operative versus non-operative, raising the question about the real effectiveness of surgery in influencing the natural history of this pathology and about the choice of the most appropriate approach (anterior vs. posterior). The authors report a retrospective review of 70 consecutive patients who underwent elective anterior cervical corpectomy and fusion with iliac crest autograft or titanium mesh and placement of an anterior cervical plate for the treatment of CSM. The patients underwent pre-and postoperative evaluation, including history, and physical and neurological examination. Patients were also evaluated pre-and postoperatively using a modified version of the Japanese Orthopedics Association Scale (mJOA), which provides a fine semi-quantitative graded evaluation of overall function. Upon discharge home, patients were followed for an average of 42 months (range, 12-63 months). Following an anterior cervical decompression of the spinal cord, 94.2% of patients improved their functional status and 5.8% were unchanged; the mean preoperative mJOA score of all patients was 12.2, the postoperative was 15.4 and the amelioration was also documented by neurophysiological studies which showed an increase in amplitude and decrease in latency of somatosensory evoked potentials and motor evoked potential in 47 patients (67%). Older age and longer duration of preoperative symptoms both were not associated with a lower postoperative mJOA score (p < 0.47, p < 0.29, respectively). Single versus multiple level decompression was not predictive of a lower postoperative mJOA score (p < 0.18). Preoperative spinal cord low signal intensity changes on T1-weighted MRI were related to a lower postoperative mJOA score (p < 0.05), whereas spinal cord high-signal intensity changes on T2-weighted MRI were related to a higher postoperative mJOA score (p < 0.01); finally a lower preoperative mJOA score was highly predictive of a lower postoperative mJOA score (p < 0.0005). Anterior cervical corpectomy and fusion for CSM appears to be an effective procedure with a more favorable neurological improvement when compared to posterior decompressive laminectomy, minimally invasive procedures or non-surgical treatment. It is also a safe procedure even in the elderly population, with low morbidity and the potential for permanent spinal cord decompression and excellent bone stability.

The use of virtual fluoroscopy in managing acute type II odontoid fracture with anterior single-screw fixation. A safe, effective, elegant and fast form of treatment.

BACKGROUND: The management of odontoid fractures represents both a clinical and a technical challenge due to the singular anatomy and biomechanics of the region. At present there is still much controversy as far as any form of management (surgical vs. conservative) is concerned and in any case there is not sufficient evidence to support a standardized form of treatment. This study was designed to further evaluate safety and efficacy of anterior odontoid single-screw fixation and to better determine the usefulness of Image Guided Surgery Virtual Fluoroscopy in treating such cases assessing also its advantages over traditional fluoroscopy and CT-guided frameless stereotaxy in the upper cervical spine surgery. METHODS: This was a retrospective review of ten patients presented during a short period of 18 months with acute traumatic Type II odontoid fractures. Nine underwent fixation within a mean of 3 days after injury, whereas a patient had to be operated upon on the 22nd day due to poor alignment with conservative treatment and ongoing instability. All patients postoperatively were fitted in a collar and then followed-up with serial clinical and radiographic examinations. FINDINGS: Radiological signs of fusion were seen in 10 cases (100%) (mean follow-up: 16 months). No complications occurred during the surgical procedure, nor were any instrumentation failures recorded; all patients remained neurologically intact. CONCLUSIONS: We believe that anterior odontoid screw fixation using Image Guided Surgery virtual fluoroscopy is a safe, effective, less time consuming and low x-ray exposure technique and we recommend this as the preferred treatment method for acute Type II odontoid fractures. Moreover, the use of image guided technology affords more precision, confidence and safety enabling the surgeon to approach the upper cervical spine in an easier and faster way.

Temozolomide as first-line agent in treating high-grade gliomas: phase II study.

UNLABELLED: Temozolomide a recent, oral, second generation alkylating agent is a chemotherapeutic with demonstrated efficacy for the treatment of high-grade gliomas; its efficacy has been demonstrated in both pre-clinical and phase I and II studies. The goal of this study is to determine the activity and safety of temozolomide in improving overall survival (OS), progression-free survival (PFS) and health-related quality of life (HQL) in patient with malignant gliomas. Forty-two patients with newly diagnosed glioblastoma, anaplastic astrocytoma and anaplastic oligodendroglioma were studied. The mean follow-up period was 12 months. The overall response rate (only responsive patient) for all histological groups was 40%, 10 patients (24%) showed a stabilization of disease. The median PFS and OS was respectively 8.35 and 14.1 months: time to progression was 34 week ranging from 21 to 47. In all patients, treatment with temozolomide was associated with improvement of performance status including the patient showing disease progression: Karnofski score improved in all patients by a minimum of 10, with a median of 20 at 6 months. No patient stopped the treatment due to side-effects, no major adverse events were recorded. CONCLUSION: Temozolomide appears to be an ideal, first-line, single-agent, with a safe profile and demonstrated HQL benefits in patients with high-grade gliomas.

Polyamine metabolism in primary human colon adenocarcinoma cells (SW480) and their lymph node metastatic derivatives (SW620).

The natural polyamines are multifunctional constituents of all eucaryotic cells. The objective of this work was to compare aspects of polyamine metabolism in two related cell lines with the idea to investigate whether metabolic differences can be attributed to functional differences of the cells. The human colon carcinoma-derived cell lines SW480 and SW620 were chosen as models. SW480 cells were isolated from the primary tumour, SW620 cells from a lymph node of the same patient. SW620 cells grow faster, and the key regulatory enzymes of polyamine biosynthesis (ODC and AdoMetDC) are more active in the metastatic cells. Moreover, their ability to accumulate polyamines from the environment is more important than of SW480 cells. Likewise polyamine concentrations were markedly higher in SW620 cells, although they are much smaller than SW480 cells, and have a particularly small cytoplasmic space. Both cell lines show a striking diminution of ODC and AdoMetDC activities and changes in the polyamine patterns at the transition from exponential to non-exponential growth--most probably as a consequence of high cell density. Depletion of putrescine and spermidine due to inactivation of ODC by DFMO causes accumulation of cells in G1, and a proportional decrease of S-phase cells in both cell lines. Based on morphologic and other criteria SW480 and SW620 cells were typified as poorly differentiated. In agreement with their low grade of differentiation they exhibit a low alkaline phosphatase activity. However, the time-dependent decrease of alkaline phosphatase is not typical of differentiation patterns of other adenocarcinoma-derived cell lines or of normal enterocytes. The high capacity of de novo polyamine biosynthesis and of polyamine uptake is presumably a prerequisite for the rapid growth and invasiveness. The fact that these properties were more accentuated in the case of SW620 cells and paralleled enhanced metastatic properties indicate relationships between basic parameters of polyamine metabolism and malignancy.

Cytotoxic effects of the polyamine oxidase inactivator MDL 72527 to two human colon carcinoma cell lines SW480 and SW620.

N1,N4-bis(2,3-butadienyl)-1,4-butanediamine (MDL 72527) was considered to be a selective inactivator of FAD-dependent tissue polyamine oxidase. Recently MDL 72527 was reported to induce apoptosis in transformed hematopoietic cells through lysosomotropic effects. Since it is the only useful inhibitor of polyamine oxidase available at present, the re-evaluation of its properties seemed important. Human colon carcinoma-derived SW480 cells and their lymph node metastatic derivatives (SW620) were chosen for our study because they differ in various aspects of polyamine metabolism but have similar polyamine oxidase activities. MDL 72527 inhibited cell growth in a concentration-dependent manner, depleted intracellular polyamine pools, and caused the accumulation of N1-acetyl derivatives of spermidine and spermine. SW620 cells were more sensitive to the drug than were SW480 cells. At 150 micromol/L MDL 72527, SW620 cells accumulated in S-phase of the cell cycle, showed decreased polyamine transport rate, and showed no increase of polyamine N1-acetyltransferase activity. In contrast, SW480 cells were not arrested in a particular phase of the cell cycle, showed enhanced polyamine uptake, and showed a mild induction of acetyltransferase. The results suggest that MDL 72527 retains its value as a selective tool in short-term experiments only at concentrations not exceeding those necessary for the inactivation of polyamine oxidase. At concentrations above 50 micromol/L and at exposure times longer than 24 h, it may derange cell functions nonspecifically, and thus blur the results of studies intended to elucidate polyamine oxidase functions.

Perturbation by geraniol of cell membrane permeability and signal transduction pathways in human colon cancer cells.

Geraniol, a natural component of plant essential oils, has antiproliferative effects on human colon cancer cells. To obtain more insight into its mechanism of action, we studied its effect on the resting membrane potential and on the expression of proteins involved in cell signaling pathways. Since geraniol is a well known inhibitor of mevalonate metabolism, the effect of mevalonate supplementation on geraniol-triggered growth inhibition was also determined. Geraniol (400 microM) induced membrane depolarization with a decrease of membrane resistance due to local perforation of the cell membrane. Incubation of Caco-2 cells with geraniol (400 microM) for 6 h caused a 60% reduction of protein kinase C (PKC) activity. After 16 h of incubation, geraniol decreased by 50% the amount of active forms of p44/p42 extracellular signal-regulated protein kinases (ERK). Mevalonate supplementation did not reverse inhibition of cell growth by geraniol. These results indicate that the antiproliferative effect of geraniol on Caco-2 cells was not related to a limitation of the mevalonate pool but was directly linked to the perturbation of cell membrane function leading to the reduction of PKC activity and to the decreased expression of p44/p42 ERK active forms.

Geraniol, a component of plant essential oils, sensitizes human colonic cancer cells to 5-Fluorouracil treatment.

Differentiation of human colonic cancer cells at confluency has been correlated to their increased resistance to chemotherapeutic agents. The aim of this study was to determine whether blocking Caco-2 cell differentiation could sensitize the cells to 5-fluorouracil (5-FU) treatment. We show that in cells at confluency, geraniol (400 microM) prevented the formation of brush-border membranes and inhibited the expression of intestinal hydrolases (sucrase, lactase, alkaline phosphatase). The antiproliferative effect of geraniol (400 microM) together with 5-FU (5 microM) was twice that of 5-FU alone. The cytotoxicity induced by 5-FU was enhanced in the presence of geraniol, as shown by a 50% increase of lactate dehydrogenase release in the culture medium. These effects are related to enhanced intracellular accumulation of 5-FU in the presence of geraniol as shown by a 2-fold increase in intracellular 5-[6-(3)H]FU (1.5 microCi/ml). It is concluded that geraniol sensitizes colonic cancer cells to 5-FU treatment, by increasing the cytotoxicity of the drug, and that this results from the facilitated transport of 5-FU and the blockade of the morphological and functional differentiation of the cancer cells.

Geraniol, a component of plant essential oils, inhibits growth and polyamine biosynthesis in human colon cancer cells.

Geraniol and other monoterpenes found in essential oils of fruits and herbs have been suggested to represent a new class of agents for cancer chemoprevention. As a first step in clarifying the mode of action of geraniol on colon carcinogenesis, we studied its effects on the growth of a human colon cancer cell line (Caco-2). Geraniol (400 microM) caused a 70% inhibition of cell growth, with cells accumulating in the S transition phase of the cell cycle, and concomitant inhibition of DNA synthesis. No signs of cytotoxicity or apoptosis were detected. Geraniol caused a 50% decrease of ornithine decarboxylase activity, a key enzyme of polyamine biosynthesis, which is enhanced in cancer growth. This led to a 40% reduction of the intracellular pool of putrescine. Geraniol also activated the intracellular catabolism of polyamines, indicated by enhanced polyamine acetylation. These observations indicate that polyamine metabolism is presumably a target in the antiproliferative properties of geraniol.

Spinal meningiomas in pregnancy: report of two cases and review of the literature.

Although meningiomas of the spinal district are frequently found, first presentation of these growths during pregnancy is extremely rare. Few cases have been reported in the literature up to now. In a series of 122 spinal meningiomas operated-on at our institution over the period 1962-1994, first neurological symptoms and signs became evident during pregnancy in two cases. Considering this noteworthy, the hydrodynamic and hormone-mediated mechanisms regarding meningioma growth during pregnancy and a review of the pertinent literature are discussed.