To aid preclinical development of novel therapeutics for myeloma, an in vivo model which recapitulates the human condition is required. An important feature of such a model is the interaction of myeloma cells with the bone marrow microenvironment, as this interaction modulates tumour activity and protects against drug-induced apoptosis. Therefore NOD/SCIDγcnull mice were injected intra-tibially with luciferase-tagged myeloma cells. Disease progression was monitored by weekly bioluminescent imaging (BLI) and measurement of paraprotein levels. Results were compared with magnetic resonance imaging (MRI) and histology. Assessment of model suitability for preclinical drug testing was investigated using bortezomib, melphalan and two novel agents. Cells engrafted at week 3, with a significant increase in BLI radiance occurring between weeks 5 and 7. This was accompanied by an increase in paraprotein secretion, MRI-derived tumour volume and CD138 positive cells within the bone marrow. Treatment with known anti-myeloma agents or novel agents significantly attenuated the increase in all disease markers. In addition, intra-tibial implantation of primary patient plasma cells resulted in development of myeloma within bone marrow. In conclusion, using both myeloma cell lines and primary patient cells, we have developed a model which recapitulates human myeloma by ensuring the key interaction of tumour cells with the microenvironment.
Biomarker identification is becoming increasingly important for the development of personalized or stratified therapies. Metabolomics yields biomarkers indicative of phenotype that can be used to characterize transitions between health and disease, disease progression and therapeutic responses. The desire to reproducibly detect ever greater numbers of metabolites at ever diminishing levels has naturally nurtured advances in best practice for sample procurement, storage and analysis. Reciprocally, since many of the available extensive clinical archives were established prior to the metabolomics era and were not processed in such an ‘ideal’ fashion, considerable scepticism has arisen as to their value for metabolomic analysis. Here we have challenged that paradigm.
We performed proton nuclear magnetic resonance spectroscopy-based metabolomics on blood serum and urine samples from 32 patients representative of a total cohort of 1970 multiple myeloma patients entered into the United Kingdom Medical Research Council Myeloma IX trial.
Using serial paired blood and urine samples we detected metabolite profiles that associated with diagnosis, post-treatment remission and disease progression. These studies identified carnitine and acetylcarnitine as novel potential biomarkers of active disease both at diagnosis and relapse and as a mediator of disease associated pathologies.
These findings show that samples conventionally processed and archived can provide useful metabolomic information that has important implications for understanding the biology of myeloma, discovering new therapies and identifying biomarkers potentially useful in deciding the choice and application of therapy.
Next generation DNA sequencing (NGS) technologies have revolutionized the pace at which whole genome and exome sequences can be generated. However, despite these advances, many of the methods for targeted resequencing, such as the generation of high-depth exome sequences, are somewhat limited by the relatively large amounts of starting DNA that are normally required. In the case of tumour analysis this is particularly pertinent as many tumour biopsies often return submicrogram quantities of DNA, especially when tumours are microdissected prior to analysis. Here, we present a method for exome capture and resequencing using as little as 50 ng of starting DNA. The sequencing libraries generated by this minimal starting amount (MSA-Cap) method generate datasets that are comparable to standard amount (SA) whole exome libraries that use three micrograms of starting DNA. This method, which can be performed in most laboratories using commonly available reagents, has the potential to enhance large scale profiling efforts such as the resequencing of tumour exomes.
The unfolded ensemble in aqueous solution represents the starting point of protein folding. Characterisation of this species is often difficult since the native state is usually predominantly populated at equilibrium. Previous work has shown that the four-helix protein, Im7 (immunity protein 7), folds via an on-pathway intermediate. While the transition states and folding intermediate have been characterised in atomistic detail, knowledge of the unfolded ensemble under the same ambient conditions remained sparse. Here, we introduce destabilising amino acid substitutions into the sequence of Im7, such that the unfolded state becomes predominantly populated at equilibrium in the absence of denaturant. Using far- and near-UV CD, fluorescence, urea titration and heteronuclear NMR experiments, we show that three amino acid substitutions (L18A–L19A–L37A) are sufficient to prevent Im7 folding, such that the unfolded state is predominantly populated at equilibrium. Using measurement of chemical shifts, 15N transverse relaxation rates and sedimentation coefficients, we show that the unfolded species of L18A–L19A–L37A deviates significantly from random-coil behaviour. Specifically, we demonstrate that this unfolded species is compact (Rh = 25 Å) relative to the urea-denatured state (Rh ≥ 30 Å) and contains local clusters of hydrophobic residues in regions that correspond to the four helices in the native state. Despite these interactions, there is no evidence for long-range stabilising tertiary interactions or persistent helical structure. The results reveal an unfolded ensemble that is conformationally restricted in regions of the polypeptide chain that ultimately form helices I, II and IV in the native state.
► An unfolded variant of Im7 has been created in nondenaturing conditions. ► The variant is collapsed but lacks fixed secondary or tertiary structure. ► Transient helicity and collapse prime the protein towards folding.
TS1, transition state 1; TS2, transition state 2; ColE7, colicin E7; SSP, secondary structure propensity; smFRET, single-molecule Förster resonance energy transfer; Im7, immunity protein 7; EDTA, ethylenediaminetetraacetic acid; HSQC, heteronuclear single quantum coherence; AUC, analytical ultracentrifugation; ITC, isothermal titration calorimetry; BMRB, Biological Magnetic Resonance Data Bank; NOE, nuclear Overhauser enhancement; AABUF, average area buried upon folding; PDB, Protein Data Bank; protein folding; NMR; unfolded ensemble; denatured state; immunity protein
Unlike a number of amyloid-forming proteins, stefins, and in particular stefin B (cystatin B) form amyloids under conditions where the native state predominates. In order to trigger oligomerization processes, the stability of the protein needs to be compromised, favoring structural re-arrangement however, accelerating fibril formation is not a simple function of protein stability. We report here on how optimal conditions for amyloid formation lead to the destabilization of dimeric and tetrameric states of the protein in favor of the monomer. Small, highly localized structural changes can be mapped out that allow us to visualize directly areas of the protein which eventually become responsible for triggering amyloid formation. These regions of the protein overlap with the Cu (II)-binding sites which we identify here for the first time. We hypothesize that in vivo modulators of amyloid formation may act similarly to painstakingly optimized solvent conditions developed in vitro. We discuss these data in the light of current structural models of stefin B amyloid fibrils based on H-exchange data, where the detachment of the helical part and the extension of loops were observed.
Cu (II)-binding; precursors of amyloid; cystatin B; stefin B; proline isomerization
Myeloma bone disease (BD) not only impairs quality of life, but is also associated with impaired survival. Studies of the biology underlying BD support the notion that the increased osteoclastogenesis and suppressed osteoblastogenesis, is both a consequence and a necessity for tumour growth and clonal expansion. Survival and expansion of the myeloma clone is dependent on its interactions with bone elements, thus targeting these interactions should have antimyeloma activities. Indeed both experimental and clinical findings indicate that bone-targeted therapies not only improve BD, but also create an inhospitable environment for myeloma cell growth and survival, favouring improved clinical outcome. This review summarizes recent progress in our understandings of the biology of myeloma BD, highlighting the role of osteoclasts and osteoblasts in this process and how they can be targeted therapeutically. Unravelling the mechanisms underlying myeloma-bone interactions will facilitate the development of novel therapeutic agents to treat BD, which as a consequence are likely to improve the clinical outcome of myeloma patients.
Multiple myeloma; Bone disease; Osteoclast; Osteoblast; Therapy
Bisphosphonates are the standard of care for reducing the risk of skeletal-related events in patients with bone lesions from multiple myeloma. The MRC Myeloma IX study was designed to compare the effects of zoledronic acid versus clodronic acid in newly diagnosed patients with multiple myeloma. Here, we report the secondary outcomes relating to skeletal events.
Patients (≥18 years) with newly diagnosed multiple myeloma were enrolled from 120 centres in the UK and received intensive or non-intensive antimyeloma treatment. A computer-generated randomisation sequence was used to allocate patients in a 1:1 ratio, through an automated telephone service to intravenous zoledronic acid (4 mg every 21–28 days) or oral clodronic acid (1600 mg/day), and the drugs were continued at least until disease progression. No investigators, staff, or patients were masked to treatment allocation. The primary endpoints—overall survival, progression-free survival, and overall response rate—and adverse events have been reported previously. We assessed between-group differences with Cox proportional hazards models for time to first skeletal-related event and incidence of skeletal-related events. These were defined as fractures, spinal cord compression, radiation or surgery to bone, and new osteolytic lesions. Data were analysed until disease progression. Analyses were by intention to treat. This trial is registered, number ISRCTN68454111.
1960 patients were randomly assigned and analysed—981 in the zoledronic acid group and 979 in the clodronic acid group. This trial is fully enrolled, and follow-up continues. At a median follow-up of 3·7 years (IQR 2·9–4·7), patients in the zoledronic acid group had a lower incidence of skeletal-related events than did those in the clodronic acid group (265 [27%] vs 346 [35%], respectively; hazard ratio 0·74, 95% CI 0·62–0·87; p=0·0004). Zoledronic acid was also associated with a lower risk of any skeletal-related event in the subsets of patients with (233 [35%] of 668 vs 292 [43%] of 682 with clodronic acid; 0·77, 0·65–0·92; p=0·0038) and without bone lesions at baseline (29 [10%] of 302 vs 48 [17%] of 276 with clodronic acid; 0·53, 0·33–0·84; p=0·0068). Fewer patients in the zoledronic acid group had vertebral fractures than did those in the clodronic acid group (50 [5%] in the zoledronic acid group vs 88 [9%] in the clodronic acid group; p=0·0008), other fractures (45 [5%] vs 66 [7%]; p=0·04), and new osteolytic lesions (46 [5%] vs 95 [10%]; p<0·0001).
The results of this study support the early use of zoledronic acid rather than clodronic acid in patients with newly diagnosed multiple myeloma for the prevention of skeletal-related events, irrespective of bone disease status at baseline.
Medical Research Council (London, UK), Novartis, Schering Health Care, Chugai, Pharmion, Celgene, and Ortho Biotech.
Both the upper (endocervix and uterus) and lower (ectocervix and vagina) female genital tract mucosa are considered to be target sites for sexual transmission of HIV. There are a few reports on the T cell and antigen-presenting cell distribution in human endometrial tissue however, there is little known about the expression of the HIV co-receptor CCR5 and HIV-binding C-type lectin receptors on endometrial cell subsets. We therefore assessed endometrial tissue sections from HIV seronegative women undergoing hysterectomy of a benign and non-inflammatory cause for phenotypic characterization of potential HIV target cells and receptors by immunohistochemistry. Langerin was expressed on intraepithelial CD1a+CD4+ and CD11c+CD4+ Langerhans cells. Furthermore, CCR5+CD4+CD3+ T cells, DC-SIGN+MR+CD11c+ myeloid dendritic cells and MR+CD68+ macrophages were found within or adjacent to the epithelium of the uterine lumen. In addition, occasional CD123+ BDCA-2+ plasmacytoid dendritic cells were detected deep in the endometrial stroma. Both T cells and several antigen-presenting cells were detected in lymphoid aggregate formations in close proximity to the epithelial lining. The finding of intraepithelial and stromal Langerin+ cells as well as CCR5+ CD4+ T cells is novel for human endometrium.
The study exploits a natural human experimental model of subsistence farmers experiencing chronic and seasonally modified food shortages and infectious burden. Two seasons existed, one of increased deprivation and infections (Jul-Dec), another of abundance and low infections (Jan-Jun); referred to as the hungry/high infection and harvest/low infection seasons respectively. Prior analysis showed a 10-fold excess in infectious disease associated mortality in young adults born in the hungry/high infection versus harvest/low infection season, and reduced thymic output and T cell counts in infancy. Here we report findings on the role of early life stressors as contributors to the onset of T cell immunological defects in later life.
We hypothesised that season of birth effects on thymic function and T cell immunity would be detectable in young adults since Kaplan-Meier survival curves indicated this to be the time of greatest mortality divergence. T cell subset analyses by flow-cytometry, sjTRECs, TCRVβ repertoire and telomere length by PCR, were performed on samples from 60 males (18-23 y) selected to represent births in the hungry/high infection and harvest/low infection
Total lymphocyte counts were normal and did not differ by birth season. CD3+ and CD4+ but not CD8+ counts were lower for those born during the hungry/high infection season. CD8+ telomere length also tended to be shorter. Overall, CD8+ TCRVβ repertoire skewing was observed with 'public' expressions and deletions seen in TCRVβ12/22 and TCRVβ24, respectively but no apparent effect of birth season.
We conclude that, although thymic function was unchanged, the CD4+ and CD3+ counts, and CD8+ telomere length results suggested that aspects of adult T cell immunity were under the influence of early life stressors. The endemicity of CMV and HBV suggested that chronic infections may modulate immunity through T cell repertoire development. The overall implications being that, this population is at an elevated risk of premature immunosenescence possibly driven by a combination of nutritional and infectious burden.
Structure of the Ire1 autophosphorylation complex and implications for the unfolded protein response
In the endoplasmic reticulum, unfolded proteins stimulate Ire1 autophosphorylation and RNase activity. The crystal structure of the dephosphorylated kinase/RNase domain of human Ire1 bound to ADP provides insight into the autophosphorylation reaction.
Ire1 (Ern1) is an unusual transmembrane protein kinase essential for the endoplasmic reticulum (ER) unfolded protein response (UPR). Activation of Ire1 by association of its N-terminal ER luminal domains promotes autophosphorylation by its cytoplasmic kinase domain, leading to activation of the C-terminal ribonuclease domain, which splices Xbp1 mRNA generating an active Xbp1s transcriptional activator. We have determined the crystal structure of the cytoplasmic portion of dephosphorylated human Ire1α bound to ADP, revealing the ‘phosphoryl-transfer' competent dimeric face-to-face complex, which precedes and is distinct from the back-to-back RNase ‘active' conformation described for yeast Ire1. We show that the Xbp1-specific ribonuclease activity depends on autophosphorylation, and that ATP-competitive inhibitors staurosporin and sunitinib, which inhibit autophosphorylation in vitro, also inhibit Xbp1 splicing in vivo. Furthermore, we demonstrate that activated Ire1α is a competent protein kinase, able to phosphorylate a heterologous peptide substrate. These studies identify human Ire1α as a target for development of ATP-competitive inhibitors that will modulate the UPR in human cells, which has particular relevance for myeloma and other secretory malignancies.
autophosphorylation; dimerisation; inhibition; signal transduction; UPR
This review presents an overview of the most recent data using the novel agents thalidomide, bortezomib, and lenalidomide in the treatment of multiple myeloma and summarizes European treatment practices incorporating these novel agents.
The treatment of multiple myeloma (MM) has undergone significant developments in recent years. The availability of the novel agents thalidomide, bortezomib, and lenalidomide has expanded treatment options and has improved the outcome of patients with MM. Following the introduction of these agents in the relapsed/refractory setting, they are also undergoing investigation in the initial treatment of MM. A number of phase III trials have demonstrated the efficacy of novel agent combinations in the transplant and nontransplant settings, and based on these results standard induction regimens are being challenged and replaced. In the transplant setting, a number of newer induction regimens are now available that have been shown to be superior to the vincristine, doxorubicin, and dexamethasone regimen. Similarly, in the front-line treatment of patients not eligible for transplantation, regimens incorporating novel agents have been found to be superior to the traditional melphalan plus prednisone regimen. Importantly, some of the novel agents appear to be active in patients with high-risk disease, such as adverse cytogenetic features, and certain comorbidities, such as renal impairment. This review presents an overview of the most recent data with these novel agents and summarizes European treatment practices incorporating the novel agents.
Multiple myeloma; Thalidomide; Bortezomib; Lenalidomide
Myeloma is a clonal malignancy of plasma cells. Poor prognosis risk is currently identified by clinical and cytogenetic features. However, these indicators do not capture all prognostic information. Gene expression analysis can be used to identify poor prognosis patients and this can be improved by combination with information about DNA level changes.
Using SNP-based gene mapping in combination with global gene expression analysis we have identified homozygous deletions in genes and networks that are relevant to myeloma pathogenesis and outcome.
We identified 170 genes with homozygous deletions and corresponding loss of expression. Deletion within the “Cell Death” network was over-represented and cases with these deletions have impaired overall survival. From further analysis of these events, we have generated an expression-based signature associated with shorter survival in 258 patients and confirmed this signature in data from 2 independent groups totalling 800 patients. We defined a gene expression signature of 97 cell death genes that reflects prognosis confirmed this in two independent data sets.
We developed a simple 6-gene expression signature from the 97-gene signature that can be used to identify poor prognosis myeloma in the clinical environment. The signature can form the basis of future trials aimed at improving the outcome of poor prognosis myeloma.
Vaccinia virus (VACV) uses microtubules for export of virions to the cell surface and this process requires the viral protein F12. Here we show that F12 has structural similarity to kinesin light chain (KLC), a subunit of the kinesin-1 motor that binds cargo. F12 and KLC share similar size, pI, hydropathy and cargo-binding tetratricopeptide repeats (TPRs). Moreover, molecular modeling of F12 TPRs upon the crystal structure of KLC2 TPRs showed a striking conservation of structure. We also identified multiple TPRs in VACV proteins E2 and A36. Data presented demonstrate that F12 is critical for recruitment of kinesin-1 to virions and that a conserved tryptophan and aspartic acid (WD) motif, which is conserved in the kinesin-1-binding sequence (KBS) of the neuronal protein calsyntenin/alcadein and several other cellular kinesin-1 binding proteins, is essential for kinesin-1 recruitment and virion transport. In contrast, mutation of WD motifs in protein A36 revealed they were not required for kinesin-1 recruitment or IEV transport. This report of a viral KLC-like protein containing a KBS that is conserved in several cellular proteins advances our understanding of how VACV recruits the kinesin motor to virions, and exemplifies how viruses use molecular mimicry of cellular components to their advantage.
Vaccinia virus (VACV), the vaccine used to eradicate smallpox, exploits the host cell motor kinesin-1 to export virus particles to the cell surface. We demonstrate that the VACV F12 protein has structural similarity with kinesin light chain (KLC) and facilitates viral transport using a kinesin binding sequence (KBS) that is conserved in several neuronal proteins. Dysfunction of some of these neuronal proteins can contribute to diseases, such as Alzheimer's. Mutation of the KBS in protein F12 showed it is essential for kinesin recruitment to virions and for virion transport to the cell surface. These findings enhance our understanding of how viruses hijack the host cell transport system, demonstrate conservation of a kinesin binding motif in cellular and viral proteins and identify targets for drug development.
Inflammation and immune activation have repeatedly been suggested as pathogentic factors in irritable bowel syndrome (IBS). The driving force for immune activation in IBS remains unknown. The aim of our study was to find out if the obligate intracellular pathogen Chlamydia could be involved in the pathogenesis of IBS.
We studied 65 patients (61 females) with IBS and 42 (29 females) healthy controls in which IBS had been excluded. Full thickness biopsies from the jejunum and mucosa biopsies from the duodenum and the jejunum were stained with a monoclonal antibody to Chlamydia lipopolysaccharide (LPS) and species-specific monoclonal antibodies to C. trachomatis and C. pneumoniae. We used polyclonal antibodies to chromogranin A, CD68, CD11c, and CD117 to identify enteroendocrine cells, macrophages, dendritic, and mast cells, respectively.
Chlamydia LPS was present in 89% of patients with IBS, but in only 14% of healthy controls (p < 0.001) and 79% of LPS-positive biopsies were also positive for C. trachomatis major outer membrane protein (MOMP). Staining for C. pneumoniae was negative in both patients and controls. Chlamydia LPS was detected in enteroendocrine cells of the mucosa in 90% of positive biopsies and in subepithelial macrophages in 69% of biopsies. Biopsies taken at different time points in 19 patients revealed persistence of Chlamydia LPS up to 11 years. The odds ratio for the association of Chlamydia LPS with presence of IBS (43.1; 95% CI: 13.2-140.7) is much higher than any previously described pathogenetic marker in IBS.
We found C. trachomatis antigens in enteroendocrine cells and macrophages in the small bowel mucosa of patients with IBS. Further studies are required to clarify if the presence of such antigens has a role in the pathogenesis of IBS.
Identifying mutations that stabilize proteins is challenging because most substitutions are destabilizing. In addition to being of immense practical utility, the ability to evolve protein stability in vivo may indicate how evolution has formed today's protein sequences. Here we describe a genetic selection that directly links the in vivo stability of proteins to antibiotic resistance. It allows the identification of stabilizing mutations within proteins. The large majority of mutants selected for improved antibiotic resistance are stabilized both thermodynamically and kinetically, indicating that similar principles govern stability in vivo and in vitro. The approach requires no prior structural or functional knowledge and allows selection for stability without a need to maintain function. Mutations that enhance thermodynamic stability of the protein Im7 map overwhelmingly to surface residues involved in binding to colicin E7, implying that evolutionary pressures that drive Im7-E7 complex formation may have compromised the stability of the isolated Im7 protein.
Deletions of chromosome 1 have been described in 7-40% of cases of myeloma with inconsistent clinical consequences. CDKN2C at 1p32.3 has been identified in myeloma cell lines as the potential target of the deletion. We tested the clinical impact of 1p deletion and used high resolution techniques to define to role of CDKN2C in primary patient material.
We analyzed 515 cases of monoclonal gammopathy of undetermined significance (MGUS), smoldering multiple myeloma (SMM) and newly diagnosed multiple myeloma (MM) using fluorescence in situ hybridization (FISH) for deletions of CDNK2C. In 78 myeloma cases, we carried out Affymetrix SNP mapping and U133 plus 2.0 expression arrays. In addition, we performed mutation, methylation and western blotting analysis.
By FISH we identified deletion of 1p32.3 (CDKN2C) in 3/66 MGUS (4.5%), 4/39 SMM (10.3%) and 55/369 MM cases (15%). We examined the impact of copy number change at CDKN2C on overall survival (OS), and found that the cases with either hemizygous or homozygous deletion of CDKN2C had a worse OS compared to cases which were intact at this region (22 months vs. 38 months; P = 0.003). Using gene mapping we identified three homozygous deletions (HD) at 1p32.3, containing CDKN2C, all of which lacked expression of CDKN2C. Cases with HD of CDKN2C were the most proliferative myelomas, defined by an expression-based proliferation index, consistent with its biological function as a cyclin-dependent kinase inhibitor.
Our results suggest that deletions of CDKN2C are important in the progression and clinical outcome of myeloma.
CDKN2C gene; Homozygous deletion; Multiple Myeloma; mapping array; expression array
We have engaged in an international program designated the Bank On A Cure, which has established DNA banks from multiple cooperative and institutional clinical trials, and a platform for examining the association of genetic variations with disease risk and outcomes in multiple myeloma.
We describe the development and content of a novel custom SNP panel that contains 3404 SNPs in 983 genes, representing cellular functions and pathways that may influence disease severity at diagnosis, toxicity, progression or other treatment outcomes. A systematic search of national databases was used to identify non-synonymous coding SNPs and SNPs within transcriptional regulatory regions. To explore SNP associations with PFS we compared SNP profiles of short term (less than 1 year, n = 70) versus long term progression-free survivors (greater than 3 years, n = 73) in two phase III clinical trials.
Quality controls were established, demonstrating an accurate and robust screening panel for genetic variations, and some initial racial comparisons of allelic variation were done. A variety of analytical approaches, including machine learning tools for data mining and recursive partitioning analyses, demonstrated predictive value of the SNP panel in survival. While the entire SNP panel showed genotype predictive association with PFS, some SNP subsets were identified within drug response, cellular signaling and cell cycle genes.
A targeted gene approach was undertaken to develop an SNP panel that can test for associations with clinical outcomes in myeloma. The initial analysis provided some predictive power, demonstrating that genetic variations in the myeloma patient population may influence PFS.
In rural Gambia, birth season predicts infection-related adult mortality, providing evidence that seasonal factors in early life may programme immune development. This study tested whether lymphocyte subpopulations assessed by automated full blood count and flow cytometry in cord blood and at 8, 16 and 52 weeks in rural Gambian infants (N = 138) are affected by birth season (DRY = Jan-Jun, harvest season, few infections; WET = Jul-Dec, hungry season, many infections), birth size or micronutrient status.
Geometric mean cord and postnatal counts were higher in births occurring in the WET season with both season of birth and season of sampling effects. Absolute CD3+, CD8+, and CD56+ counts, were higher in WET season births, but absolute CD4+ counts were unaffected and percentage CD4+ counts were therefore lower. CD19+ counts showed no association with birth season but were associated with concurrent plasma zinc status. There were no other associations between subpopulation counts and micronutrient or anthropometric status.
These results demonstrate a seasonal influence on cell counts with a disproportionate effect on CD8+ and CD56+ relative to CD4+ cells. This seasonal difference was seen in cord blood (indicating an effect in utero) and subsequent samples, and is not explained by nutritional status. These findings are consistent with the hypothesis than an early environmental exposure can programme human immune development.
This paper explores the possible association between antibiotics prescribed in infancy and allergic disorders, mainly eczema and asthma, in childhood.
No-one fully understands why childhood asthma and eczema have become so common. Some authorities suggest that there may be an association between eczema and asthma and antibiotics prescribed in childhood; however, others disagree.
The available literature was reviewed to examine the links between prescribed antibiotics and childhood eczema and asthma.
Some, but not all, research indicates that antibiotic administration in pregnancy, childbirth or infancy may be linked to childhood asthma and eczema, but much uncertainty remains. None of the papers identified stated the doses of antibiotics prescribed. In addition, we were unable to locate studies reporting the interactions between antibiotics and the developing immune system.
Health care professionals should be selective when prescribing antibiotics. Further prospective work is needed to guide the prescribing of antibiotics in childbirth and infancy.
Allergic disorders; antibiotics; prescribing; adverse drug reactions; evidence based practice.
The introduction of bortezomib, a novel first-in-class proteasome inhibitor, has been a major break through in the treatment of multiple myeloma. It is currently approved for the treatment of myeloma in the relapsed setting post transplant or as a second line treatment in patients unsuitable for transplantation. In pre-clinical studies bortezomib showed a number of different anti-myeloma effects including disruption of the cell cycle and induction of apoptosis, alteration of the bone marrow microenvironment and inhibition of nuclear factor kappa B (NFκB). Due to its novel mechanism of action, bortezomib has been shown to induce responses in previously refractory patients (including those with poor risk cytogenetics), and results in an increased progression free and overall survival in relapsed patients when compared with dexamethasone treatment alone. It is well tolerated and can be administered in the outpatient setting with manageable toxicities. Peripheral neuropathy is the most common dose limiting toxicity and thrombocytopenia can generally be managed with platelet transfusions without reducing or omitting doses. Bortezomib shows a synergistic effect in combination with dexamethasone and also sensitises myeloma cells to the effects of other chemotherapeutic agents with major response rates of over 50% being shown in the relapsed setting. Initial data from ongoing trials in front line therapy are encouraging with response rates of 80%–90% when bortezomib is given in combination with other agents and importantly, the ability to mobilize peripheral blood stem cells is not impaired.
myeloma; bortezomib; proteasome inhibition; treatment
Current population screening for vascular disease is neither efficient nor effective. Peter Elwood and colleagues believe we should have a public information strategy highlighting the benefits (and risks) of aspirin for older people, but Colin Baigent argues that the evidence of benefit is not yet strong enough
Bortezomib is a highly selective, reversible inhibitor of the 26S proteasome that is indicated for single-agent use in the treatment of patients with multiple myeloma who have received at least 2 prior therapies and are progressing on their most recent therapy. Clinical investigations have been completed or are under way to evaluate the safety and efficacy of bortezomib alone or in combination with chemotherapy in multiple myeloma, both at relapse and presentation, as well as in other cancer types. The antiproliferative, proapoptotic, antiangiogenic, and antitumor activities of bortezomib result from proteasome inhibition and depend on the altered degradation of a host of regulatory proteins. Exposure to bortezomib has been shown to stabilize p21, p27, and p53, as well as the proapoptotic Bid and Bax proteins, caveolin-1, and inhibitor κB-α, which prevents activation of nuclear factor κB-induced cell survival pathways. Bortezomib also promoted the activation of the proapoptotic c-Jun-NH2 terminal kinase, as well as the endoplasmic reticulum stress response. The anticancer effects of bortezomib as a single agent have been demonstrated in xenograft models of multiple myeloma, adult T-cell leukemia, lung, breast, prostate, pancreatic, head and neck, and colon cancer, and in melanoma. In these preclinical in vivo studies, bortezomib treatment resulted in decreased tumor growth, angiogenesis, and metastasis, as well as increased survival and tumor apoptosis. In several in vitro and/or in vivo cancer models, bortezomib has also been shown to enhance the antitumor properties of several antineoplastic treatments. Importantly, bortezomib was generally well tolerated and did not appear to produce additive toxicities when combined with other therapies in the dosing regimens used in these preclinical in vivo investigations. These findings provide a rationale for further clinical trials using bortezomib alone or in combination regimens with chemotherapy, radiation therapy, immunotherapy, or novel agents in patients with hematologic malignancies or solid tumors.