We examine how changes in a surrogate marker of tumour vessel density correlate with response and resistance to anti-angiogenic therapy.
In metastatic renal cancer patients treated with anti-angiogenic tyrosine kinase inhibitors, arterial phase contrast-enhanced computed tomography was used to simultaneously measure changes in: (a) tumour size, and (b) tumour enhancement (a surrogate marker of tumour vessel density) within individual lesions.
No correlation between baseline tumour enhancement and lesion shrinkage was observed, but a reduction in tumour enhancement on treatment was strongly correlated with reduction in lesion size (r=0.654, P<0.0001). However, close examination of individual metastases revealed different types of response: (1) good vascular response with significant tumour shrinkage, (2) good vascular response with stabilisation of disease, (3) poor vascular response with stabilisation of disease and (4) poor vascular response with progression. Moreover, contrasting responses between different lesions within the same patient were observed. We also assessed rebound vascularisation in tumours that acquired resistance to treatment. The amplitude of rebound vascularisation was greater in lesions that had a better initial response to therapy (P=0.008).
Changes in a surrogate marker of tumour vessel density correlate with response and resistance to anti-angiogenic therapy. The data provide insight into the mechanisms that underlie response and resistance to this class of agent.
angiogenesis; metastasis; tyrosine kinase inhibitor; resistance; renal cell carcinoma
We used a combination of whole-genome sequencing and in vitro validation to show that mutations that activated at least two pro-growth/survival pathways mediated intrinsic resistance to BRAF inhibition in a melanoma patient. These data demonstrate how in-depth analysis can reveal intrinsic resistance to standard of care, providing an opportunity for alternative therapeutic strategies for patients who are likely to fail first-line treat-575 ment.
BRAF is mutated in ∼42% of human melanomas (COSMIC. http://www.sanger.ac.uk/genetics/CGP/cosmic/) and pharmacological BRAF inhibitors such as vemurafenib and dabrafenib achieve dramatic responses in patients whose tumours harbour BRAFV600 mutations. Objective responses occur in ∼50% of patients and disease stabilisation in a further ∼30%, but ∼20% of patients present primary or innate resistance and do not respond. Here, we investigated the underlying cause of treatment failure in a patient with BRAF mutant melanoma who presented primary resistance.
We carried out whole-genome sequencing and single nucleotide polymorphism (SNP) array analysis of five metastatic tumours from the patient. We validated mechanisms of resistance in a cell line derived from the patient's tumour.
We observed that the majority of the single-nucleotide variants identified were shared across all tumour sites, but also saw site-specific copy-number alterations in discrete cell populations at different sites. We found that two ubiquitous mutations mediated resistance to BRAF inhibition in these tumours. A mutation in GNAQ sustained mitogen-activated protein kinase (MAPK) signalling, whereas a mutation in PTEN activated the PI3 K/AKT pathway. Inhibition of both pathways synergised to block the growth of the cells.
Our analyses show that the five metastases arose from a common progenitor and acquired additional alterations after disease dissemination. We demonstrate that a distinct combination of mutations mediated primary resistance to BRAF inhibition in this patient. These mutations were present in all five tumours and in a tumour sample taken before BRAF inhibitor treatment was administered. Inhibition of both pathways was required to block tumour cell growth, suggesting that combined targeting of these pathways could have been a valid therapeutic approach for this patient.
BRAF; melanoma; mechanisms of resistance; intra-tumour heterogeneity; tumour evolution
Poly adenosine diphosphate (ADP)-ribose polymerase (PARP) is essential in cellular processing of DNA damage via the base excision repair pathway (BER). The PARP inhibition can be directly cytotoxic to tumour cells and augments the anti-tumour effects of DNA-damaging agents. This study evaluated the optimally tolerated dose of olaparib (4-(3--4-fluorophenyl) methyl-1(2H)-one; AZD2281, KU0059436), a potent PARP inhibitor, with dacarbazine and assessed safety, toxicity, clinical pharmacokinetics and efficacy of combination treatment.
Patients and methods:
Patients with advanced cancer received olaparib (20–200 mg PO) on days 1–7 with dacarbazine (600–800 mg m−2 IV) on day 1 (cycle 2, day 2) of a 21-day cycle. An expansion cohort of chemonaive melanoma patients was treated at an optimally tolerated dose. The BER enzyme, methylpurine-DNA glycosylase and its substrate 7-methylguanine were quantified in peripheral blood mononuclear cells.
The optimal combination to proceed to phase II was defined as 100 mg bd olaparib with 600 mg m−2 dacarbazine. Dose-limiting toxicities were neutropaenia and thrombocytopaenia. There were two partial responses, both in patients with melanoma.
This study defined a tolerable dose of olaparib in combination with dacarbazine, but there were no responses in chemonaive melanoma patients, demonstrating no clinical advantage over single-agent dacarbazine at these doses.
chemotherapy; dacarbazine; melanoma; PARP; resistance
Chemotherapy-induced febrile neutropenia is a medical emergency complicating the treatment of many cancer patients. It is associated with considerable morbidity and mortality, as well as impacting on healthcare resources.
A prospective study of all cases of chemotherapy-induced febrile neutropenia in the South West London Cancer Network was conducted over a 4-month period. Factors including demographics, treatment history, management of febrile neutropenia and outcome were recorded.
Results and conclusi:
Our results reflect those of the recent National Chemotherapy Advisory Group (NCEPOD, 2008)/National Confidential Enquiry into Patient Outcomes and Death reports (NCAG, 2009) and highlight the need for network-wide clinical care pathways to improve outcomes in this area.
neutropenic sepsis; chemotherapy; infection; febrile neutropenia
Optimum efficacy is the primary goal for any cancer therapy, and entails controlling tumour growth and prolonging survival as far as possible. The prognosis for patients with metastatic renal cell carcinoma (mRCC) has greatly improved with the introduction of targeted therapies. This review examines the development and efficacy of targeted agents for the management of mRCC, the challenges offered by their rapid emergence, and discusses how mRCC treatment may evolve in the future. Improvements in progression-free survival and overall survival rates, observed with targeted agents, indicate that it may now be possible to change mRCC from a rapidly fatal and largely untreatable condition into a chronic disease. The major challenges to further advances in targeted therapy for mRCC include overcoming drug resistance, identifying the most effective sequence or combination of targeted agents, optimising clinical trial design and managing the cost of treatment.
chronic disease; combinatorial therapy; renal cell carcinoma; sequential therapy; sunitinib malate; targeted agents
There is clinical evidence to suggest that tumour necrosis factor-α (TNF-α) may be a therapeutic target in renal cell carcinoma (RCC). Multi-targeted kinase inhibitors, such as sorafenib and sunitinib, have become standard of care in advanced RCC. The anti-TNF-α monoclonal antibody infliximab and sorafenib have differing cellular mechanisms of action. We conducted a phase I/II trial to determine the safety and efficacy of infliximab in combination with sorafenib in patients with advanced RCC.
Eligible patients were systemic treatment-naive or had received previous cytokine therapy only. Sorafenib and infliximab were administered according to standard schedules. The study had two phases: in phase I, the safety and toxicity of the combination of full-dose sorafenib and two dose levels of infliximab were evaluated in three and three patients, respectively, and in phase II, further safety, toxicity and efficacy data were collected in an expanded patient population.
Acceptable safety was reported for the first three patients (infliximab 5 mg kg−1) in phase 1. Sorafenib 400 mg twice daily and infliximab 10 mg kg−1 were administered to a total of 13 patients (three in phase 1 and 10 in phase 2). Adverse events included grade 3 hand–foot syndrome (31%), rash (25%), fatigue (19%) and infection (19%). Although manageable, toxicity resulted in 75% of the patients requiring at least one dose reduction and 81% requiring at least one dose delay of sorafenib. Four patients were progression-free at 6 months (PFS6 31%); median PFS and overall survival were 6 and 14 months, respectively.
Sorafenib and infliximab can be administered in combination, but a significant increase in the numbers of adverse events requiring dose adjustments of sorafenib was observed. There was no evidence of increased efficacy compared with sorafenib alone in advanced RCC. The combination of sorafenib and infliximab does not warrant further evaluation in patients with advanced RCC.
renal cell carcinoma; sorafenib; infliximab
We report a case of a 44-year old female who presented to her physician complaining of mild dyspnea. A follow-up chest X-ray and chest computed tomography scan revealed a giant bilateral intrathoracic mass, filling the right thoracic cavity and extending across the anterior mediastinum into the left chest cavity. This large mass caused a marked shift in the midline structures, displacing the heart to the left hemi-thorax. The patient underwent surgical removal of the thoracic and breast mass, with histologic examination confirming the diagnosis of a giant intrathoracic lipoma, weighing 4,320 grams and measured 34 × 28 × 11 cm. It is the largest intrathoracic lipoma documented in the modern literature.
Temozolomide is an alkylating agent with activity in the treatment of melanoma metastatic to the brain. Lomustine is a nitrosurea that crosses the blood brain barrier and there is evidence to suggest that temozolomide may reverse resistance to lomustine. A multicentre phase I/II study was conducted to assess the maximum-tolerated dose (MTD), safety and efficacy of the combination of temozolomide and lomustine in melanoma metastatic to the brain. Increasing doses of temozolomide and lomustine were administered in phase I of the study to determine the MTD. Patients were treated at the MTD in phase II of the study to six cycles, disease progression or unacceptable toxicity. Twenty-six patients were enrolled in the study. In phase I of the study, the MTD was defined as temozolomide 150 mg m−2 days 1–5 every 28 days and lomustine 60 mg m–2 on day 5 every 56 days. Dose-limiting neutropaenia and thrombocytopaenia were observed at higher doses. Twenty patients were treated at this dose in phase II of the study. No responses to therapy were observed. Median survival from starting chemotherapy was 2 months. The combination of temozolomide and lomustine in patients with brain metastases from melanoma does not demonstrate activity. The further evaluation of this combination therefore is not warranted.
cerebral metastases; melanoma; chemotherapy; lomustine; temozolomide
To assess thiamine status by analysis of plasma, erythrocytes and urine in type 1 and type 2 diabetic patients and links to markers of vascular dysfunction.
Diabetic patients (26 type 1 and 48 type 2) with and without microalbuminuria and 20 normal healthy control volunteers were recruited. Erythrocyte activity of transketolase, the concentrations of thiamine and related phosphorylated metabolites in plasma, erythrocytes and urine, and markers of metabolic control and vascular dysfunction were determined.
Plasma thiamine concentration was decreased 76% in type 1 diabetic patients and 75% in type 2 diabetic patients: normal volunteers 64.1 (95% CI 58.5–69.7) nmol/l, type 1 diabetes 15.3 (95% CI 11.5–19.1) nmol/l, p < 0.001, and type 2 diabetes 16.3 (95% CI 13.0–9.6) nmol/l, p < 0.001. Renal clearance of thiamine was increased 24-fold in type 1 diabetic patients and 16-fold in type 2 diabetic patients. Plasma thiamine concentration correlated negatively with renal clearance of thiamine (r = −0.531, p < 0.001) and fractional excretion of thiamine (r = −0.616, p < 0.001). Erythrocyte transketolase activity correlated negatively with urinary albumin excretion (r = −0.232, p < 0.05). Thiamine transporter protein contents of erythrocyte membranes of type 1 and type 2 diabetic patients were increased. Plasma thiamine concentration and urinary excretion of thiamine correlated negatively with soluble vascular adhesion molecule-1 (r = −0.246, p < 0.05, and −0.311, p < 0.01, respectively).
Low plasma thiamine concentration is prevalent in patients with type 1 and type 2 diabetes, associated with increased thiamine clearance. The conventional assessment of thiamine status was masked by increased thiamine transporter content of erythrocytes.
Adhesion molecules; Microalbuminuria; Thiamine; Type 1 diabetes; Type 2 diabetes
Background: Evidence for disease modifying activity of low dose corticosteroid treatment in rheumatoid arthritis is contradictory. Studies showing radiological benefit suggest that continued treatment is required to sustain the effect.
Objective: To evaluate the effect of low dose oral prednisolone in early rheumatoid arthritis on disease activity over two years.
Design: Double blind placebo controlled trial.
Methods: Patients with rheumatoid arthritis, duration <3 years (n = 167), were started on a disease modifying antirheumatic drug (DMARD; sulphasalazine) and allocated by stratified randomisation to prednisolone 7 mg/day or placebo. Primary outcome measure was radiological damage, assessed by the modified Sharp method. Clinical benefit was a secondary outcome. A proactive approach to identifying and treating corticosteroid adverse events was adopted. Patients who discontinued sulphasalazine were offered an alternative DMARD.
Results: 90 of 257 patients eligible for the study refused to participate (more women than men). Of those enrolled, 84% were seropositive for rheumatoid factor, median age 56 years, median disease duration 12 months, female to male ratio 1.8:1. Prednisolone was given to 84 patients; of these 73% continued prednisolone and 70% sulphasalazine at 2 years. Of the 83 patients on placebo, 80% continued placebo and 64% sulphasalazine at 2 years. There were no significant differences in radiological score or clinical and laboratory measures at 0 and 2 years.
Conclusions: Low dose prednisolone conferred no radiological or clinical benefit on patients maintained on a DMARD over two years. Low dose corticosteroids have no role in the routine management of rheumatoid arthritis treated with conventional disease modifying drugs.
Chronic ethanol consumption induces hepatocellular retention of nascent proteins leading to hepatomegaly. While the molecular mechanisms behind this impairment are undefined, it has been predicted that protein retention results from a disruption of vesicle-mediated secretory processes. Small GTP-binding proteins (rab proteins) have recently been implicated in the regulation of vesicular trafficking in eukaryotic cells. Our objectives were to identify intracellular sites of ethanol-induced protein retention and to determine whether the distribution of secretory rab proteins was altered by ethanol. Transport of hepatic proteins along the secretory pathway in livers from control and ethanol-fed rats was analyzed using subcellular fractionation and immunoprecipitation in the context of in vivo pulse-chase experiments. We show that pre-Golgi and Golgi compartments, as well as secretory vesicles, are sites of ethanol-induced retention of nascent soluble and transmembrane secretory proteins. These results are supported by immunofluorescence localization of hepatic proteins on liver sections. Further, immunoblot analyses of hepatic subcellular fractions from ethanol-damaged livers indicate a dramatic reduction in the association of rab2 with a Golgi compartment as compared with controls. In contrast, rab6 and alpha-mannosidase II, Golgi marker proteins, appear unchanged. These studies provide a detailed analysis of the intracellular site of ethanol-induced protein retention in the hepatocyte and lend novel insight into a potential mechanism behind this impairment. The effects of ethanol exposure on rab proteins and Golgi function are discussed.
Overheating may cause terminal apnoea and cot death. Rectal temperature and breathing patterns were examined in normal infants at home during the first 6 months of life. Twenty one infants had continuous overnight rectal temperature and breathing recordings for 429 nights (mean 20.4 nights, range 7-30) spaced over the first six months of life. Periods when breathing was 'regular' were directly marked on single night records. Sleep state was determined from respiratory variables. 'Regular' breathing was a reliable marker of 'quiet' sleep (specificity 93%). The duration of 'quiet' sleep increased from 6 to 22 minutes from two weeks to three months of age and then remained static, as did the proportion of sleep spent in the quiet phase (9% to 34%). Rectal temperature fell during 66% of quiet sleep and usually rose during rapid eye movement (REM) sleep. The drop in rectal temperature was maximal at the start of quiet sleep, whereas the maximum rise during REM sleep was reached after 10 to 15 minutes. Oscillations in rectal temperature are associated with changes in sleep and breathing state. The maturation of rectal temperature patterns during the first six months of life are closely related to a maturation of sleep state and breathing patterns.
Earlier studies demonstrated that dietary omega-3 polyunsaturated fatty acid (PUFA) supplementation attenuates the chemotactic response of neutrophils and the generation of leukotriene (LT) B4 by neutrophils stimulated with calcium ionophore; however, the mechanisms and relationship of these effects were not examined. Neutrophils and monocytes from eight healthy individuals were examined before and after 3 and 10 wk of dietary supplementation with 20 g SuperEPA daily, which provides 9.4 g eicosapentaenoic acid (EPA) and 5 g docosahexaenoic acid. The maximal neutrophil chemotactic response to LTB4, assessed in Boyden microchambers, decreased by 69% after 3 wk and by 93% after 10 wk from prediet values. The formation of [3H]inositol tris-phosphate (IP3) by [3H]inositol-labeled neutrophils stimulated by LTB4 decreased by 71% after 3 wk (0.033 +/- 0.013% [3H] release, mean +/- SEM) and by 90% after 10 wk (0.011 +/- 0.011%) from predict values (0.114 +/- 0.030%) as quantitated by beta-scintillation counting after resolution on HPLC. LTB4-stimulated neutrophil chemotaxis and IP3 formation correlated significantly (P < 0.0001); each response correlated closely and negatively with the EPA content of the neutrophil phosphatidylinositol (PI) pool (P = 0.0003 and P = 0.0005, respectively). Neither the affinities and densities of the high and low affinity LTB4 receptors on neutrophils nor LTB4-mediated diglyceride formation changed appreciably during the study. Similar results were observed in neutrophils activated with platelet-activating factor (PAF). The summed formation of LTB4 plus LTB5 was selectively inhibited in calcium ionophore-stimulated neutrophils and was also inhibited in zymosan-stimulated neutrophils. The inhibition of the summed formation of LTB4 plus LTB5 in calcium ionophore-stimulated neutrophils and in zymosan-stimulated neutrophils did not correlate significantly with the EPA content of the PI pool. The data indicate that dietary omega-3 PUFA supplementation inhibits the autoamplification of the neutrophil inflammatory response by decreasing LTB4 formation through the inactivation of the LTA epoxide hydrolase and independently by inhibiting LTB4- (and PAF) stimulated chemotaxis by attenuating the formation of IP3 by the PI-selective phospholipase C. This is the initial demonstration that dietary omega-3 PUFA supplementation can suppress signal transduction at the level of the PI-specific phospholipase C in humans.
A battery of psychometric tests was administered to 85 patients with epilepsy, of whom 26 were untreated, 40 received carbamazepine monotherapy and 19 took carbamazepine with another anticonvulsant. Carbamazepine alone had little effect on performance, but carbamazepine polypharmacy produced significant impairment. Increasing concentrations of carbamazepine (four tests) and its active metabolite, carbamazepine 10,11 epoxide (seven tests), correlated with decreasing performance in the monotherapy patients.
Thirty-five patients with rheumatoid arthritis were randomly allocated to either Seatone (green-lipped mussel extract) or placebo in order to assess the former's claimed effectiveness in rheumatoid disease. After six months there was no significant improvement in any laboratory or clinical measurement of disease activity in the Seatone group. The patients on active drug fared no better than those on placebo. These results suggest that Seatone is not effective in rheumatoid arthritis.
Swarm cells of Thiothrix nivea were found to possess a group of fimbriae at one pole. The other pole either was bare or possessed from one to three fimbriae. By using this polarity as a marker, it was found that the initial step in attachment of swarm cells involves the fimbriated pole and that this initial step is followed by the production of holdfast material.
The Saccharomyces cerevisiae CRY1 gene encodes ribosomal protein rp59, a component of the 40S ribosomal subunit. Mutations in CRY1 can confer resistance to the alkaloid cryptopleurine, an inhibitor of the elongation step of translation. The nucleotide sequence of the cloned CRY1 gene was determined. The predicted amino acid sequence shows that CRY1 encodes a 14,561-dalton polypeptide that has 88% amino acid sequence homology to the hamster or human S14 ribosomal protein responsible for emetine resistance and 45% homology to Escherichia coli ribosomal protein S11. Analysis of the DNA sequences upstream from CRY1 revealed the presence of three sequences, HOMOL1 (consensus, A/TACATCC/TG/ATA/GCA), RPG (consensus, ACCCA/GTACATT/CT/A), and a thymine-rich sequence, found upstream of more than 20 other cloned yeast genes encoding components of the translational apparatus. We exploited the ability to assay the expression of CRY1 in vivo by using the cryptopleurine resistance phenotype to demonstrate that these three consensus sequences are necessary for the transcription of CRY1. We previously showed that the upstream promoter element of the yeast RP39A gene consists of these identical sequence motifs. Therefore, we suggest that these three sequences define a consensus promoter element for the genes encoding the yeast translational apparatus. CRY1 is one of several hundred yeast genes, including ribosomal protein genes, whose expression is transiently decreased 10-fold upon heat shock. We found that the HOMOL1 and RPG consensus sequences are not necessary for the heat shock response of CRY1.
Using cloned DNA from the vicinity of the yeast mating type locus (MAT) as a probe, the wild type allele of the cryptopleurine resistance gene CRY1 has been isolated by the technique of chromosome walking and has been shown to be identical to the gene for ribosomal protein 59. A recessive cryR1 allele has also been cloned, using the integration excision method. The genetic distance from MAT to CRY1 is 2.2 cM, while the physical distance is 21 kb, giving a ratio of about 10 kb/cM for this interval. The phenotypic expression of both plasmid borne alleles of the gene can be detected in vivo. The use of this gene as a hybridization probe to examine RNA processing defects in the rna 2, rna 3, rna 4, rna 8, and rna 11 mutants is also discussed.
We investigated the influence of temperature, in the range of 45 to 5 C, on the rate of oxidation of glucose and citrate by intact cells and cell-free extracts of psychrophilic Bacillus psychrophilus and mesophilic B. thuringiensis. Both glucose and endogenous oxidation by whole and disrupted cells of the psychrophile decreased more slowly with decrease in temperature than did glucose and endogenous oxidation by whole and disrupted cells of the mesophile. Similar results were obtained for the oxidation of citrate by cell-free extracts. Since substrate permeability is not involved in the oxidative metabolism of the cell-free extracts, we concluded that the internal enzymes of the psychrophile differ from those of the mesophile.