Effect of patient socioeconomic status on access to early-phase cancer trials

PURPOSE

Little is known about the influence of socioeconomic factors on patient access to cancer trials. Differences should be considered to ensure generalizability of trial results and equality of access.

METHODS

Phase I trials unit referrals at our center over 5 years, from 2007 to 2012, were reviewed. Socioeconomic status was defined by the Index of Multiple Deprivation (IMD; 1, least deprived; 5, most deprived). Multivariate analysis was performed comparing incident cancer cases with referred patients and those ultimately enrolled onto a trial.

RESULTS

Four hundred thirty patients were referred (median age, 62 years). Compared with 10,784 incident cases, referral was less likely for patients in the more-deprived quintiles compared with the least deprived (IMD 5: odds ratio [OR], 0.53; 95% CI, 0.38 to 0.74). Once reviewed in the unit, enrollment onto a trial was not affected (IMD 5: OR, 0.81; 95% CI, 0.40 to 1.63). Ethnicity analysis showed the nonwhite population was less likely to be recruited (OR, 0.48; 95% CI, 0.26 to 0.88). This relationship was lost with adjustment for age, sex, cancer type, and deprivation index.

CONCLUSION

We show for the first time to our knowledge that socioeconomic status affects early-phase cancer trial referrals. The least-deprived patients are almost twice as likely to be referred compared with the most deprived. This may be because more-deprived patients are less suitable for a trial-as a result of comorbidities, for example-or because of inequalities that could be addressed by patient or referrer education. Once reviewed at the unit, enrollment onto a trial is not affected by deprivation.

Trace metals, peroxidase activity, PAHs contents and ecophysiological changes in Quercus ilex leaves in the urban area of Caserta (Italy)

Trace metals and polycyclic aromatic hydrocarbons, severely affecting human, animal and plants health, highly contribute to the air pollution in urban areas mainly due to car traffic. In this study the air biomonitoring of the city of Caserta (South Italy) has been performed by using Quercus ilex L., a widespread ornamental plant in parks, gardens and avenues. The plant leaves from different sites within the urban area were collected and used to determine the concentrations of V, Cd, Cr, Pb, Ni, Cu, and PAHs as well as the free amino acid content and peroxidase enzyme activity as indices of the leaf physiological conditions. All the tested trace metals showed concentrations higher than the control site. Lead was positively correlated to Cd and Cr and showed, also, a positive trend with Ni and Cu that, in their turn, were highly correlated between them. Positive and significant correlations were evidenced between total PAHs and carcinogenic PAHs and negative correlations between those and all trace metals assayed except V. Cu and Cd contents evidence negative correlations with peroxidase activity, and the free amino acid contents. The PAHs, in particular Carc-PAHs, were negatively correlated to the tested heavy metals. POD was positively correlated only with V and negatively correlated with Cu and Cd.

A phase I study of S-222611 an oral reversible dual inhibitor of EGFR and HER2, in patients with solid tumors

3100

Background: S-222611 is a novel oral, potent, reversible tyrosine kinase inhibitor with antiproliferative activity in human tumor cell lines expressing EGFR and/or HER2 in vitro and in mouse xenograft models. We conducted the first study in patients (pts) with solid tumors expressing EGFR or HER2. Methods: Daily oral doses of S-222611 were escalated in successive cohorts from 100 mg to a maximum 1600 mg, using a 3 + 3 design. Full plasma pharmacokinetic (PK) profiles were obtained in all pts for 7 days after a single dose on Day 1 and for 24 h following 21 days of once daily dosing (Cycle 1). Trough PK samples were drawn weekly during the first 3 weeks of daily dosing. A CT scan was performed at baseline and every 8 weeks post-dose to assess response (RECIST). Results: Of 23 treated pts (16 male) aged 24-77y, 19 completed Cycle 1. One dose-limiting toxicity (DLT) has been seen to date, a rash at 1200 mg, which resolved on interruption and dose reduction. Other adverse events related to drug, diarrhea, rash, and nausea, were mild (grade 1 or 2) but more frequent at higher doses. Tumor responses have been seen over a wide range of doses. One complete clinical response was observed at 1200 mg in a pt with HER2 positive breast carcinoma previously treated with lapatinib and trastuzumab. Two pts showed confirmed partial responses (one with EGFR positive renal cell carcinoma at 200 mg daily and one with EGFR and HER2 positive esophageal carcinoma at 400 mg daily); 2 pts showed unconfirmed partial responses and 3 pts (with vaginal, gastric and pancreatic adenoCa) showed stable disease for >6 months (mo); 2 pts have been treated for >12 mo. Plasma Cmax, AUC and steady state concentrations increased with dose up to 1200 mg, exceeding those eliciting maximal responses in mice. The plasma t½ is >24 h. Conclusions: S-222611 was generally tolerated well in doses up to 1200 mg, with only one DLT; rash, diarrhea and nausea have been readily manageable. PK data support once daily dosing to achieve highly effective concentrations. A substantial proportion of patients with HER2 or EGFR expressing tumors have shown partial responses or stable disease (>6 mo) and one patient has shown a complete clinical response.

Heavy metal content in sediments along the Calore river: relationships with physical-chemical characteristics

In the present study, trace metals contents (V, Cr, Mn, Fe, Ni, Cu, Zn, Cd and Pb) and physico-chemical parameters (nitrogen, organic and inorganic carbon, pH and particle size) in sediments samples along the Calore river were analyzed in two seasons. Sediment samples were collected in ten sites upstream and downstream of the city of Benevento and its industrial area, the confluence of Sabato and Tammaro tributaries, and the confluence of Calore and Volturno rivers. The highest contents of trace metals were found, generally, in the sites immediately downstream of industrial area and of Benevento city. The sites on the Tammaro and Sabato also showed relatively high contents of Ni and, only for Sabato sites, of Cr, and Fe. With the exception of Cd, the heavy metal contents were highest in the last site of Calore river, which therefore is a source of pollution to the Volturno river. Besides the sites downstream of Benevento city showed the higher pH values and also the highest contents of fine particles size and organic matter. Positive correlations among trace metals, organic substance, particle size sediments were found. The data obtained in this study were analyzed with reference to Interim Sediment Quality Guidelines and indicated moderate-to-high pollution by some trace metals (V, Cr, Mn, Fe, Ni, Cu).

Unusual presentation for a patent ductus arteriosus

A 63-yr-old black female, with a 1-yr history of hepatitis C and ascites was referred to an expert centre with suspicion of portopulmonary hypertension (PPHTN). Her poor condition made a rapid diagnosis imperative and precluded a normal diagnostic work-up. Echocardiography confirmed severe pulmonary hypertension (PH). A hepatic scintigraphy and an abdominal echo-Doppler study excluded liver cirrhosis and portal hypertension. Cardiac magnetic resonance imaging showed marked dilation of the right ventricle with significant hypertrophy of the free wall, a finding that is uncommon in idiopathic pulmonary arterial hypertension or PPHTN. Right heart catheterisation demonstrated severe pre-capillary PH without response to acute vasodilator testing. Finally the patient underwent computed tomography angiography, which showed marked dilation of the pulmonary artery without thromboembolic disease and, unexpectedly, a partially calcified large patent ductus arteriosus. The correct diagnosis of the underlying cause of pulmonary arterial hypertension is essential. Patients with underlying heart defects may have an atypical presentation and be referred to expert centres with an incorrect diagnosis. A full investigation is necessary; careful examination of right ventricular anatomy can provide clues about the aetiology of PH, and it is important to exclude intra- and extracardiac shunts during haemodynamic studies.

Microbial activities and trace element contents in an urban soil

Soil biological properties are influenced by trace metals. The main sources of these pollutants in the urban areas are industrial plants, power stations, domestic heating systems and motor vehicles. The aim of this work was to evaluate, in relation to distance from urban roads, soil trace metal concentrations (Pb, Cu, Cr, Cd and V) and their influence on C-microbial biomass as well as on soil respiration and enzyme activities (phosphatase glucosidase, galactosidase, xylanase, cellulase, trealase, protease and invertase). The samplings were carried out at four sites, along a route that goes from Giannone Street to Passionisti Street, two heavily travelled roads at two different times of the year (spring and autumn). Heavy metal contents and microbial activities were highest at the sites near the roads. The highest values of microbial activities were found in the inner site; here, on the contrary, the lowest concentrations of heavy metals were measured. Significant and negative correlations were found between microbial activity and heavy metal contents.

Morphological and biochemical patterns in skeletal muscle apoptosis

Some neuromuscular disorders, such as Duchenne muscular dystrophy, hereditary inclusion body myopathy, malignant hyperthermia, alcoholic myopathy and mitochondrial myopathies are characterized by oxidative stress and loss of muscle fibres due to apoptosis. In this study we have analyzed muscle cell death in vitro utilizing C2C12 myoblasts and myotubes, inducing apoptosis by means of UVB irradiation. C2C12 cells were analysed by scanning and transmission electron microscopy (SEM, TEM) as well as by TUNEL reaction. DNA analysis was performed by gel electrophoresis and flow cytometry. MitoTracker red CMXRos and JC-1 fluorescent probes were also used to study mitochondrial behavior. Finally, caspase activity was investigated by means of Western blot, while caspase-9 and -3 inhibitor effects by means of SEM. SEM showed the typical membrane blebbing while TEM revealed the characteristic chromatin condensation. The TUNEL reaction presented a certain positivity too. Apoptotic and non-apoptotic nuclei in the same myotube were identified both by TUNEL and TEM. Gel electrophoresis never showed oligonucleosomal DNA fragmentation, in agreement with the cell cycle analysis performed by flow cytometry which did not reveal a sharp subdiploid peak. Mitochondrial response to UVB was later investigated and a decrease in mitochondrial functionality appeared. Caspase-9 and -3 cleavage, and, consequently, the activation of the caspase cascade, was also demonstrated by Western blot. Moreover a decrease in apoptotic cell number was noted after caspase-9 and-3 inhibitor treatment. All these results indicated that UVB irradiation induces apoptosis, both in myoblasts and in myotubes, the second being more resistant. DNA fragmentation, at least the nucleosomic type, does not occur. A certain double-strand cleavage appears in TUNEL analysis, as well as characteristic ultrastructural changes in chromatin.

ERK MAPK activation mediates the antiapoptotic signaling of melatonin in UVB-stressed U937 cells

The pineal gland hormone melatonin has been recently described to downregulate the intrinsic (or damage-induced) pathway of apoptosis in human leukocytes. These properties appear to depend on a specific mitochondrial signaling of melatonin which is associated with a lower generation of reactive oxygen species and a better control of redox-sensitive components such as the antiapoptotic protein Bcl-2. Other elements upstream in this signaling are expected to contribute regulatory roles that remain unexplored. The aim of this study was to investigate whether the extracellular signal-regulated kinase (ERK), which controls the balance between survival and death-promoting genes throughout the MAPK pathway, is involved in the antiapoptotic signaling of melatonin. Human monocytic U937 cells irradiated with UVB light were used as a model of stress-induced apoptosis. In this model we found that pharmacological concentrations of melatonin (1 mM) were able to decrease superoxide anion production, mitochondrial damage, and caspase-dependent apoptosis by improved Bcl-2 levels and decreased Cyt c release in the cytoplasm. Moreover, melatonin increased the phosphorylative activation of ERK 1/2 independently from the presence of UVB stress, and decreased the UVB-mediated activation of the stress kinases p38 MAPK and JNK. The ERK 1/2 inhibitor PD98059, but not the p38 MAPK inhibitor SB203580, abolished to different extents the effects that melatonin had on the UVB-induced ROS generation, mitochondrial dysfunction, and apoptosis. Using these inhibitors, a cross-talk effect between stress and survival-promoting kinases was tentatively identified, and confirmed the hierarchical role of ERK MAPK phosphorylation in the signaling of melatonin. In conclusion, melatonin sustains the activation of the survival-promoting pathway ERK MAPK which is required to antagonize UVB-induced apoptosis of U937 cells. This kinase mediates also the antioxidant and mitochondrial protection effects of this hormonal substance that may find therapeutic applications in inflammatory and immune diseases associated with leukocyte oxidative stress and accelerated apoptosis.

Assays of natural killer (NK) cell ligation to target cells

Assays for natural killer cells have long been established in the flow repertoire, but successful application of a flow-based protocol requires attention to many details. This unit provides these details in a comprehensive manner. In particular, the assay is designed for simple bench-top cytometers, rather than for more complex research instruments. Following this protocol, even a novice user should be able to achieve successful completion of an NK assay.

Coexistence of mutations in PINK1 and mitochondrial DNA in early onset parkinsonism

AIMS AND BACKGROUND

Various genes have been identified for monogenic disorders resembling Parkinson's disease. The products of some of these genes are associated with mitochondria and have been implicated in cellular protection against oxidative damage. In the present study we analysed fibroblasts from a patient carrying the homozygous mutation p.W437X in the PTEN-induced kinase 1 (PINK1), which manifested a very early onset parkinsonism.

RESULTS

Patient's fibroblasts did not show variation in the mtDNA copy number or in the expression of the oxidative phosphorylation complexes. Sequence analysis of the patient's mtDNA presented two new missense mutations in the ND5 (m.12397A>G, p.T21A) and ND6 (m. 14319T>C, p.N119D) genes coding for two subunits of complex I. The two mutations were homoplasmic in both the patient and the patient's mother. Patient's fibroblasts resulted in enhanced constitutive production of the superoxide anion radical that was abrogated by inhibitor of the complex I. Moreover enzyme kinetic analysis of the NADH:ubiquinone oxidoreductase showed changes in the substrates affinity.

CONCLUSION

To our knowledge, this is the first report showing co-segregation of a Parkinson's disease related nuclear gene mutation with mtDNA mutation(s). Our observation might shed light on the clinical heterogeneity of the hereditary cases of Parkinson's disease, highlighting the hitherto unappreciated impact of coexisting mtDNA mutations in determining the development and the clinical course of the disease.

Zymographic analysis and characterization of MMP-2 and -9 forms in human sound dentin

The role and function of dentin matrix metalloproteinases (MMPs) are not well-understood, but they may play a key role in dentinal caries and the degradation of resin-bonded dentin matrices. To test the null hypothesis that MMP-9 is not found in dentin matrix, we used gelatin zymography to extract and isolate all molecular forms of gelatinolytic MMPs in demineralized mature sound dentin powder obtained from extracted human molars, characterizing and identifying the enzymes by Western blotting. Gelatinolytic MMPs were detected in extracts of demineralized dentin matrix and identified as MMP-2 and MMP-9. Acidic extracts (pH 2.3) yielded 3-8 times more MMP activity than did EDTA (pH 7.4). Their activation may contribute to dentin matrix degradation, which occurs during caries progression and following resin bonding. Inhibition of MMP-2 and -9 proteolytic activity may slow caries progression and increase the durability of resin-dentin bonds.

Nuclear phosphatidylinositol 3,4,5-trisphosphate, phosphatidylinositol 3-kinase, Akt, and PTen: emerging key regulators of anti-apoptotic signaling and carcinogenesis

Inositol lipid-derived second messengers have long been known to have an important regulatory role in cell physiology. Phosphatidylinositol 3-kinase (PI3K) synthesizes the second messenger 3,4,5'-phosphatidylinositol trisphosphate (Ptdlns 3,4,5P3) which controls a multitude of cell functions. Down-stream of PI3K/PtdIns 3,4,5P3 is the serine/threonine protein kinase Akt (protein kinase B, PKB). Since the PI3K/ PtdIns 3,4,5P3 /Akt pathway stimulates cell proliferation and suppresses apoptosis, it has been implicated in carcinogenesis. The lipid phosphatase PTEN is a negative regulator of this signaling network. Until recently, it was thought that this signal transduction cascade would promote its anti-apoptotic effects when activated in the cytoplasm. Several lines of evidence gathered over the past 20 years, have highlighted the existence of an autonomous nuclear inositol lipid cycle, strongly suggesting that lipids are important components of signaling pathways operating at the nuclear level. PI3K, PtdIns(3,4,5)P3, Akt, and PTEN have been identified within the nucleus and recent findings suggest that they are involved in cell survival also by operating in this organelle, through a block of caspase-activated DNase and inhibition of chromatin condensation. Here, we shall summarize the most updated and intriguing findings about nuclear PI3K/ PtdIns(3,4,5)P3/Akt/PTEN in relationship with carcinogenesis and suppression of apoptosis.

Mutual cross-talk between reactive oxygen species and nuclear factor-kappa B: molecular basis and biological significance

Reactive oxygen species (ROS) are emerging as key effectors in signal transduction. This role of ROS is especially evident in the pathways leading to programmed cell death (PCD) elicited in response to certain stress stimuli and cytokines. In these pathways, cytotoxic ROS signaling appears to be mediated in part by activation of the c-Jun-N-terminal kinase (JNK) mitogen-activated protein kinase (MAPK) cascade. Another pathway that is under ROS-mediated control in some systems is that leading to activation of transcription factor nuclear factor-kappa B (NF-kappaB), which is a central regulator of immunity, inflammation and cell survival. Remarkably, new evidence has unveiled the existence of a reciprocal, negative control that NF-kappaB exerts on ROS and JNK activities. This NF-kappaB-imposed restraint on ROS and JNK signaling is crucial for antagonism of PCD elicited by the proinflammatory cytokine tumor necrosis factor (TNF)alpha and likely other triggers. Effectors of this antagonistic cross-talk between NF-kappaB and ROS/JNK pathways have recently been identified. Because of the key roles that the prosurvival function of NF-kappaB plays in organismal physiology and disease, gaining a further mechanistic understanding of this cross-talk and NF-kappaB-dependent survival may be key to developing new therapies for the treatment of widespread human illnesses, such as cancer and chronic inflammatory conditions.

Barriers to stroke thrombolysis in a geographically defined population

OBJECTIVE

Barriers to thrombolysis are rather assessed for hospitalized stroke patients than among geographically defined populations. In a population-based approach, we assessed (1) the utilization rate of stroke thrombolysis in the community, and (2) the significance of the chosen stroke care provider as a potential barrier to thrombolysis.

METHODS

We performed a databank-based post-hoc analysis, derived from data ascertained in a prospective, population-based stroke study among the permanent residents of the canton Basel-City, Switzerland. For the cohort with an onset assessment interval (OAI) < or =3 h, we compared thrombolyzed with non-thrombolyzed patients concerning demographic variables, the National Institutes of Health stroke scale (NIHSS) score, OAI, risk factors, and the type of stroke care provider. For patients without thrombolysis despite an OAI < or =3 h, barriers to thrombolysis were compiled.

RESULTS

Among 269 patients, 49 had an OAI < or =3 h (18% of all patients and 38% of those 128 patients with exactly known time of onset). Fourteen patients received thrombolysis, amounting to a utilization rate of 5.2% (95% CI 2.9-8.6) for all patients and 29% (95% CI 17-43) for the OAI < or =3-hour cohort. For the latter, thrombolyzed differed from non-thrombolyzed patients in higher NIHSS score and type of stroke care provider, but not in demographic variables, OAI, or risk factors. Fourteen of 40 patients (35%) primarily admitted to the stroke unit received thrombolysis, compared with none of 9 patients primarily treated elsewhere (p < 0.04). In the OAI < or =3-hour cohort, mild or regressing stroke severity (48%), admission to hospitals not offering thrombolysis (20%), computed tomography or laboratory contraindications (17%) and severe comorbidity (14%) were barriers to thrombolysis.

CONCLUSION

In this geographically defined population, every 20th stroke patient received thrombolysis. Only a minority of patients had an OAI < or =3 h, rendering late admission the most common barrier to thrombolysis. In the OAI < or =3-hour cohort, admission to hospitals not offering thrombolysis prompted exclusion from thrombolysis as often as established contraindications. Thus, acute stroke patients should solely be brought to hospitals providing thrombolysis.

Melatonin reduces early changes in intramitochondrial cardiolipin during apoptosis in U937 cell line

Cardiolipin (CL) is found exclusively in the inner mitochondrial membrane. CL deficiency leads to an alteration in the stability of mitochondrial membranes, to an increased permeability as well as a decreased respiratory rate, and therefore to mitochondria which are completely dysfunctional. It is known that reactive oxygen species (ROS) cause a decrease and a variation in CL content, concomitantly the formation of the mitochondrial permeability transition pore facilitates the release of cytochrome c (cyt c) into the cytosol. Melatonin (Mel), the secretory product of the pineal gland, is a potent and efficient endogenous radical scavenger. It has been shown to protect, various biomolecules, such as DNA, membrane lipids, and cytosolic proteins from oxidative damage. To evaluate the protective role of Mel, we have studied U937 cells treated with UV-B irradiation. In our model, the administration of 1mM Mel before UV-B irradiation showed a significant protection from apoptotic cell death, in particular, mitochondrial structure and function were preserved through apoptotic pathways when cells were preincubated with 1mM Mel before UV-B exposure. The cardiolipin-sensitive probe 10-nonyl acridine orange (NAO) was used to monitor changes in mitochondrial lipids. Our data suggest that the Mel treatment protects CL from ROS and this suggests a possible link with the reduction of the apoptotic phenomenon.

Human decidual natural killer cells as a source and target of macrophage migration inhibitory factor

The human uterine mucosa of early pregnancy is largely populated by CD56(bright) natural killer (NK) cells (uterine (u) NK cells). The specific functions of these cells are still unknown, but their interaction and response to foetal trophoblasts are thought to be important for the establishment of a successful pregnancy. The study reported herein shows that uNK cells respond to, and produce, macrophage migration inhibitory factor (MIF), a cytokine highly expressed in the human placenta and in the cyclic and pregnant endometrium. Recombinant human MIF reduced in a dose-dependent manner the cytolytic activity of purified uNK cells against K562 cells. RT-PCR, Western blot analysis and ELISA demonstrated the synthesis and secretion of the cytokine by uNK cells. Double immunofluorescence staining showed the presence of MIF in uterine CD56 + cells. Finally, neutralization of the endogenous cytokine by a polyclonal antibody resulted in a sharp increase in the cytolytic activity of uNK cells. These findings indicate the existence of a previously unrevealed paracrine and autocrine action of MIF on uNK cells and support its contribution to the immune privilege at the maternal-foetal interface.

Role of the JNK pathway in NMDA-mediated excitotoxicity of cortical neurons

Excitotoxic insults induce c-Jun N-terminal kinase (JNK) activation, which leads to neuronal death and contributes to many neurological conditions such as cerebral ischemia and neurodegenerative disorders. The action of JNK can be inhibited by the D-retro-inverso form of JNK inhibitor peptide (D-JNKI1), which totally prevents death induced by N-methyl-D-aspartate (NMDA) in vitro and strongly protects against different in vivo paradigms of excitotoxicity. To obtain optimal neuroprotection, it is imperative to elucidate the prosurvival action of D-JNKI1 and the death pathways that it inhibits. In cortical neuronal cultures, we first investigate the pathways by which NMDA induces JNK activation and show a rapid and selective phosphorylation of mitogen-activated protein kinase kinase 7 (MKK7), whereas the only other known JNK activator, mitogen-activated protein kinase kinase 4 (MKK4), was unaffected. We then analyze the action of D-JNKI1 on four JNK targets containing a JNK-binding domain: MAPK-activating death domain-containing protein/differentially expressed in normal and neoplastic cells (MADD/DENN), MKK7, MKK4 and JNK-interacting protein-1 (IB1/JIP-1).

Growth arrest- and DNA-damage-inducible 45beta gene inhibits c-Jun N-terminal kinase and extracellular signal-regulated kinase and decreases IL-1beta-induced apoptosis in insulin-producing INS-1E cells

AIMS/HYPOTHESIS

IL-1beta is a candidate mediator of apoptotic beta cell destruction, a process that leads to type 1 diabetes and progression of type 2 diabetes. IL-1beta activates beta cell c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK) and p38, all of which are members of the mitogen-activated protein kinase (MAPK) family. Inhibition of JNK prevents IL-1beta-mediated beta cell destruction. In mouse embryo fibroblasts and 3DO T cells, overexpression of the gene encoding growth arrest and DNA-damage-inducible 45beta (Gadd45b) downregulates pro-apoptotic JNK signalling. The aim of this study was to investigate if Gadd45b prevents IL-1beta-induced beta cell MAPK signalling and apoptosis.

MATERIALS

Rat insulinoma INS-1E cells and mouse beta-TC3 cells stably expressing Gadd45b were generated. The effects of Gadd45b expression on signalling by JNK, ERK and p38 were assessed by Western blotting and kinase assays. Apoptosis rate was measured by terminal deoxynucleotidyl-mediated dUTP-biotin nick end-labelling (TUNEL) and an ELISA designed to detect apoptotic nucleosomes. Expression of endogenous Gadd45b mRNA was measured by RT-PCR.

RESULTS

In INS-1E and beta-TC3 cells, expression of Gadd45b inhibited IL-1beta-induced activation of JNK and ERK, but augmented IL-1beta-mediated p38 activity. IL-1beta-induced nitric oxide production and decreases in insulin content and secretion were reduced by GADD45beta. IL-1beta-induced apoptosis was reduced by GADD45beta by up to 77%. Although IL-1beta stimulated the time-dependent induction of endogenous Gadd45b in INS-1E cells and rat islets, expression levels were lower in these cells than in IL-1beta-exposed NIH-3T3 and 3DO T cells.

CONCLUSIONS/INTERPRETATION

Inadequate induction of Gadd45b, which encodes a novel beta cell JNK and ERK inhibitor, may in part explain the pro-apoptotic response of beta cells to IL-1beta.

Regulation by the cAMP cascade of oxygen free radical balance in mammalian cells

A study is presented of the effect of the cAMP cascade on oxygen metabolism in mammalian cell cultures. Serum-starvation of the cell cultures resulted in depression of the forward NADH-ubiquinone oxidoreductase activity of complex I, decreased content of glutathione, and enhancement of the cellular level of H2O2. Depressed transcription of cytosolic Cu/Zn-SOD 1, mitochondrial glutathione peroxidase and catalase was also observed. Activation of the cAMP cascade reversed the depression of the activity of complex I and the accumulation of H2O2. The effect of cAMP involved the cAMP-dependent protein kinase.

The NF-κB-mediated control of the JNK cascade in the antagonism of programmed cell death in health and disease

NF-kappaB/Rel transcription factors have recently emerged as crucial regulators of cell survival. Activation of NF-kappaB antagonizes programmed cell death (PCD) induced by tumor necrosis factor-receptors (TNF-Rs) and several other triggers. This prosurvival activity of NF-kappaB participates in a wide range of biological processes, including immunity, lymphopoiesis and development. It is also crucial for pathogenesis of various cancers, chronic inflammation and certain hereditary disorders. This participation of NF-kappaB in survival signaling often involves an antagonism of PCD triggered by TNF-R-family receptors, and is mediated through a suppression of the formation of reactive oxygen species (ROS) and a control of sustained activation of the Jun-N-terminal kinase (JNK) cascade. Effectors of this antagonistic activity of NF-kappaB on this ROS/JNK pathway have been recently identified. Indeed, further delineating the mechanisms by which NF-kappaB promotes cell survival might hold the key to developing new highly effective therapies for treatment of widespread human diseases.