Insights into composition/structure/function relationships of Doxil® gained from "high-sensitivity" differential scanning calorimetry

Thermotropic behavior of Doxil® and its generic, Lipodox®, was characterized using "high-sensitivity" differential scanning calorimetry (DSC). This is the first report that two distinct endotherms were observed in Doxil and Lipodox upon heating. The first (Tm at 51±2°C) is broad and of low enthalpy, representing the membrane lipid phase transition, which occurs despite having high (38mole%) cholesterol. The second (Tm at ∼70°C) is narrow, representing melting of the intraliposomal doxorubicin-sulfate nanocrystals. The thermograms of Doxil and Lipodox are practically identical. The membrane phase transition is similar to that of drug-free nanoliposomes of the same size and lipid composition as Doxil, suggesting lack of significant drug-membrane interaction. The melting endotherm of the intraliposomal nanocrystals is 2.0-2.5-fold narrower than that of the crystals formed in a solution of 250mM ammonium sulfate and >60mg/ml doxorubicin. This suggests that nanovolume of liposomes improves doxorubicin-sulfate crystallinity. Moreover, both phase transitions are reversible in cycled DSC scanning (15-90-15°C). This indicates an unexpected "non-leaky" phospholipid phase transition and excellent physical and chemical stabilities of Doxil after short exposure to high temperature. Reducing mole% of cholesterol results in a "leaky" membrane phase transition of higher enthalpy. Namely, high mole% cholesterol is essential for the resistance to drug leakage during phase transition. Pegylated liposomal doxorubicin in which HSPC was replaced by DPPC shows the same non-leaky phase transition but at a lower temperature, indicating this type of phase transition is not unique to Doxil. The presence of DSPE-PEG2k increases the cooperativity of the phase transition. High-sensitivity DSC helps illuminate composition/structure/function relationships of Doxil, and is useful for the equivalence/similarity studies.

Research output and the public health burden of cancer: is there any relationship?

PURPOSE

The relative distribution of research output across cancer sites is not well described. Here, we evaluate whether the volume of published research is proportional to the public health burden of individual cancers. We also explore whether research output is proportional to research funding.

METHODS

Statistics from the Canadian and American cancer societies were used to identify the top ten causes of cancer death in 2013. All journal articles and clinical trials published in 2013 by Canadian or U.S. authors for those cancers were identified. Total research funding in Canada by cancer site was obtained from the Canadian Cancer Research Alliance. Descriptive statistics and Pearson correlation coefficients were used to describe the relationship between research output, cancer mortality, and research funding.

RESULTS

We identified 19,361 publications and 2661 clinical trials. The proportion of publications and clinical trials was substantially lower than the proportion of deaths for lung (41% deaths, 15% publications, 16% clinical trials), colorectal (14%, 7%, 6%), pancreatic (10%, 7%, 5%), and gastroesophageal (7%, 5%, 3%) cancers. Conversely, research output was substantially greater than the proportion of deaths for breast cancer (10% deaths, 29% publications, 30% clinical trials) and prostate cancer (8%, 15%, 17%). We observed a stronger correlation between research output and funding (publications r = 0.894, p < 0.001; clinical trials r = 0.923, p < 0.001) than between research output and cancer mortality (r = 0.363, p = 0.303; r = 0.340, p = 0.337).

CONCLUSIONS

Research output is not well correlated with the public health burden of individual cancers, but is correlated with the relative level of research funding.

A long non-coding RNA interacts with Gfra1 and maintains survival of mouse spermatogonial stem cells

Spermatogonial stem cells (SSCs) are unique male germline stem cells that support spermatogenesis and male fertility. Long non-coding RNAs (lncRNA) have been identified as key regulators of stem cell fate; however, their role in SSCs has not been explored. Here, we report that a novel spermatogonia-specific lncRNA (lncRNA033862) is essential for the survival of murine SSCs. LncRNA033862 is expressed in early spermatogonia including SSC and was among 805 lncRNAs identified by global expression profiling as responsive to glial cell-derived neurotrophic factor (GDNF), a growth factor required for SSC self-renewal and survival. LncRNA033862 is an antisense transcript of the GDNF receptor alpha1 (Gfra1) that lacks protein coding potential and regulates Gfra1 expression levels by interacting with Gfra1 chromatin. Importantly, lncRNA033862 knockdown severely impairs SSC survival and their capacity to repopulate recipient testes in a transplantation assay. Collectively, our data provide the first evidence that long non-coding RNAs (lncRNAs) regulate SSC fate.

Assessment of Disease-Related Therapeutic Protein Drug-Drug Interaction for Etrolizumab in Patients With Moderately to Severely Active Ulcerative Colitis

The efficacy and safety of etrolizumab, a humanized IgG1 mAb, were evaluated in patients with ulcerative colitis (UC) in a phase 2 study (EUCALYPTUS). The current study assessed the risk of therapeutic protein drug-drug interaction (TP-DDI) of etrolizumab on CYP3A activity in patients with UC. Literature review was performed to compare serum proinflammatory cytokine levels and pharmacokinetic (PK) parameters of CYP3A substrate drugs between patients with inflammatory bowel disease (IBD) and healthy subjects. Treatment effect of etrolizumab on CYP3A activity was evaluated by measuring colonic CYP3A4 mRNA expression and serum C-reactive protein (CRP) in EUCALYPTUS patients. Literature data suggested similar levels between IBD patients and healthy subjects for serum proinflammatory cytokines and PK parameters of CYP3A substrate drugs. Additionally, treatment with etrolizumab did not change colonic CYP3A4 mRNA expression or serum CRP levels in UC patients. In conclusion, our results indicate a low TP-DDI risk for etrolizumab in UC patients, particularly on medications metabolized by CYP3A.

High expression of HIF-2α and its anti-radiotherapy effect in lung cancer stem cells

Hypoxia-inducible factor-2 alpha (HIF-2α) has been shown to regulate cell stemness, although the expression and effects of HIF-2α in lung cancer stem cells remained unclear. This study investigated HIF-2α expression in lung cancer stem cells, as well as the relationship between HIF-2α expression and radioresistance in lung cancer cells. Stem-like cells (CD133(+)) in the non-small-cell lung cancer cell line A549 were enriched by serum-free culture conditions, and CD133(+) cells were sorted via fluorescence-activated cell sorting. A549 cells were treated with middle-infrared radiation, and the level of HIF-2α expression was determined by a quantitative polymerase chain reaction assay and western blot analysis. The level of HIF-2α expression in tissue sections from 50 cases of clinically confirmed non-small-cell lung cancer was determined via immunohistochemical analysis, and its correlation with prognosis after radiotherapy was analyzed. HIF-2α levels in CD133(+) cells were significantly higher than those in CD133(-) cells (P = 0.032). However, after radiation treatment, these levels were significantly upregulated in both CD133(+) and CD133(-) cells (P = 0.031 and P = 0.023, respectively). After irradiation, the proportions of apoptotic, dead, and autophagic CD133(+) A549 cells were considerably lower than those of CD133(-) A549 cells (P < 0.05). Furthermore, the recovery of carcinoembryonic antigen to pre-radiation levels was more rapid in lung cancer patients with high levels of HIF-2α expression, and these patients had shorter survival times (P = 0.018). HIF-2α is highly expressed in lung cancer stem cells, which may lead to radioresistance. In conclusion, HIF-2α is a potential prognostic marker for lung cancer.

Clinical research on dendritic cell vaccines to prevent postoperative recurrence and metastasis of liver cancer

We aimed to evaluate dendritic cell (DC) tumor vaccines for preventing liver cancer recurrence and metastasis. DCs were induced from mononuclear cells in the peripheral blood with recombinant human granulocyte macrophage colony stimulating factor (rhGM-CSF) and recombinant human interleukin 4 (rhIL-4), followed by sensitization with lysis of autologous liver cancer cells. One hundred and sixty patients with hepatocellular carcinoma were randomly divided into two groups of 80. One group was treated postoperatively with six cycles of the DC tumor vaccine. The other group was treated postoperatively with six cycles of FOLFOX 6, beginning 1 week after surgery. After treatment with DC tumor vaccines, the levels of CD3+, CD4+, and CD8+, the ratio of CD4+ to CD8+ DC, and the serum levels of IL-12 and IFN-γ were significantly increased both in comparison to the pre-treatment levels (P < 0.001) and to the chemotherapy group (P < 0.001). After a postoperative follow-up of 18 months, the metastatic recurrence rate in the DC tumor vaccine group was significantly lower than that in the chemotherapy group (17.50 vs 48.75%, P < 0.005), and the survival rate of the patients in the DC tumor vaccine group was higher than that of the chemotherapy treatment group (86.25 vs 52.50%, P < 0.005). Treatment with DC tumor vaccines was safe and feasible. It can enhance the immunity of the patients, reduce the rates of metastasis and recurrence, and improve survival rates. This is a promising treatment for the prevention of postoperative recurrence in patients with liver cancer.

Cross Sections for the Exclusive Photon Electroproduction on the Proton and Generalized Parton Distributions

Unpolarized and beam-polarized fourfold cross sections (d^{4}σ/dQ^{2}dx_{B}dtdϕ) for the ep→e^{'}p^{'}γ reaction were measured using the CLAS detector and the 5.75-GeV polarized electron beam of the Jefferson Lab accelerator, for 110 (Q^{2},x_{B},t) bins over the widest phase space ever explored in the valence-quark region. Several models of generalized parton distributions (GPDs) describe the data well at most of our kinematics. This increases our confidence that we understand the GPD H, expected to be the dominant contributor to these observables. Through a leading-twist extraction of Compton form factors, these results support the model predictions of a larger nucleon size at lower quark-momentum fraction x_{B}.

Challenges and considerations for development of therapeutic proteins in pediatric patients

Target specificity and generally good tolerability of therapeutic proteins (TPs) present desirable treatment opportunities for pediatric patients. However, little is known on the ontogeny of processes related to the pharmacokinetics (PK) and disposition of TPs. The science, regulatory requirements and strategy of developing TPs for children are evolving. Our current review of TPs, (with focus on monoclonal antibodies and fusion proteins) that were approved for pediatric use indicates that dose-selection for pediatric pivotal studies is often based on adult PK information alone. This approach might not be sufficient if more complex PK properties than simple linear PK are present. Body weight-based dosing for pediatric patients directly scaled down from adult dosing can lead to under-exposure in young pediatric patients who are usually in the lowest body-weight range. Tiered-fixed dosing can be reasonably effective for TPs in achieving comparable exposure in children over a wide age range. The uniqueness of the pediatric population, the practical challenges in conducting clinical studies in this population, as well as regulations from health authorities warrant including pharmacometrics as an integral component of pediatric drug development. We propose a framework distinct from previous proposals, to guide clinical pharmacology strategy for pediatric drug development specifically for TPs.

Surgical resection and peri-operative chemotherapy for colorectal cancer liver metastases: A population-based study

BACKGROUND

Most literature describing surgery for colorectal cancer (CRC) liver metastases (LM) comes from high volume centres. Here, we report management and outcomes achieved in routine clinical practice.

METHODS

All cases of CRC in Ontario who underwent resection of LM in 1994-2009 were identified using the population-based Ontario Cancer Registry. Electronic treatment records identified chemotherapy delivery. Temporal trends are described for 3 periods: 1994-1999, 2000-2004, 2005-2009. We describe volume of resected CRCLM as a ratio of incident cases per CRCLM resection. Overall (OS) and cancer-specific survival (CSS) are measured from time of LM resection.

RESULTS

2717 patients underwent resection of CRCLM. Between 1994 and 2009 there was a 78% increase in case volume; from one resection for every 48 incident cases to one resection for every 27 incident cases, p < 0.001. Use of peri-operative chemotherapy increased over study periods from 44% (306/700), to 52% (429/830), to 65% (777/1187, p < 0.001). Chemotherapy utilization rates varied across geographic regions (range 43%-69%, p < 0.001). Post-operative mortality rates at 30 and 90 days were 2.5% and 4.3% respectively. Five year OS during the study periods was 36% (95% CI 32-39%), 40% (95% CI 36-43%), and 46% (95% CI 43-49%) (p < 0.001); CSS was 38% (95% CI 35-42%), 42% (95% CI 38-45%), 49% (95% CI 44-53%) (p < 0.001). The temporal improvement in OS/CSS persisted on adjusted analyses.

CONCLUSIONS

Outcomes of patients with resected CRCLM in routine practice is comparable to those reported from high volume centres. Survival improved over the study period despite a greater proportion of patients with CRC undergoing liver resection.

The anti-inflammatory effect and potential mechanism of cardamonin in DSS-induced colitis

Cardamonin is a naturally occurring chalcone with strong anti-inflammatory activity. However, the direct effect of cardamonin on intestinal inflammation remains elusive. In the present study, we found that cardamonin markedly ameliorated dextran sulfate sodium-induced mouse body weight loss, diarrhea, colon shortening, spleen swelling, and histological damage, which correlated with a decline in the activity of myeloperoxidase and the production of nitric oxide, tumor necrosis factor-α and interleukin-6 in the colon. The upregulation of toll-like receptor 4 after dextran sulfate sodium treatment was associated with an increase in the activation of myeloid differentiation factor 88, interleukin-1 receptor-associated kinase-1, nuclear factor-κB (NF-κB) p65, inhibitor κBα, and inhibitor κB kinase-α/β, as well as the mitogen-activated protein kinase molecules of extracellular signal-regulated kinase and c-Jun NH2-terminal kinase, and this upregulation was reversed by cardamonin administration. Moreover, cardamonin blocked the nuclear translocation of NF-κB p65, inhibited NF-κB-luciferase activity, and downregulated NF-κB target genes expression. The present study clearly demonstrates a beneficial effect of cardamonin on experimental inflammatory bowel disease via a mechanism associated with suppression of toll-like receptor 4 expression and inactivation of NF-κB and mitogen-activated protein kinase pathways. This study may give insight into the further evaluation of the therapeutic potential of cardamonin or its derivatives for human inflammatory bowel disease.

Expression level and distribution of HMGB1 in Sombati's cell model and kainic acid-induced epilepsy model

OBJECTIVE

Observe the expression and distribution of HMGB1 in Sombati's cell model and kainic acid-induced epileptic rats' model.

MATERIALS AND METHODS

Dissociated hippocampal neurons from neonatal SD rats and cultured those for 9 days, then changed medium to Mg2+-free medium for 3 hours to induce Sombati's cell model. The expression level of HMGB1 in the neurons was detected at 24h and 72h by Western Blotting. Appropriate kainic acid was injected into the lateral ventricles to induced epileptic rats' model in vivo trial, the expression level and distribution of HMGB1 at 24h and 72h were established by immunohistochemistry.

RESULTS

The expression level of HMGB1 showed significantly different between model group and control group both in vitro and in vivo trials. At 24h, the expression level of HMGB1 in the model group was lower than the control group (p < 0.05), and became higher than the control group at 72h (p < 0.05). From the in vivotrial, a nucleus-to-cytoplasm translocation was also discovered.

CONCLUSIONS

This investigation indicates that HMGB1 plays a crucial role in the pathophysiology of epilepsy, by altering its quantity and distribution.

Immune memory responses to HBV vaccine 13-18 years after primary vaccination

The aim of this study was to evaluate the immune memory response 13-18 years after an hepatitis B virus (HBV) vaccine by performing a specific in vitro stimulation experiment. Thirty healthy volunteers who had been inoculated 13-18 years ago with the HBV vaccine were collected from the physical examination center. Peripheral blood mononuclear cells were stimulated with 50 ng/mL recombinant HBsAg. An ELISA kit was used for the detection of antibodies that were produced by these cells in vitro. It was found that even 13-18 years after inoculation with the HBV vaccine, an anamnestic antibody response still existed, and was not correlated with the serum antibody levels (r = -0.177, P = 0.377). In conclusion, our data showed that the individuals after inoculation, including those with anti-HBs <10 IU/L as well as those individuals in whom the antibody was not detected, retained immune memory, which may be the main role of memory B cells.

Neonatal Overfeeding in Female Mice Predisposes the Development of Obesity in their Male Offspring via Altered Central Leptin Signalling

The prevalence of obesity among child-bearing women has increased significantly. The adverse consequences of maternal obesity on the descendants have been well accepted, although few studies have examined the underlying mechanisms. We investigated whether neonatal overfeeding in female mice alters metabolic phenotypes in the offspring and whether hypothalamic leptin signalling is involved. Neonatal overfeeding was induced by reducing the litter size to three pups per litter, in contrast to normal litter size of 10 pups per litter. Normal and neonatally overfed female mice were bred with normal male mice, and offspring of overfeeding mothers (OOM) and control mothers (OCM) were generated. We examined body weight, daily food intake, leptin responsiveness and the number of positive neurones for phosphorylated-signal transducer and activator of transcription 3 (pSTAT3) along with neuropeptide Y (NPY) in the arcuate nucleus of the hypothalamus (ARH) and NPY in the nucleus tractus solitarius (NTS) of the brain stem. The body weight and daily food intake of OOM were significantly higher than those of OCM. Leptin significantly reduced food intake and increased the number of pSTAT3 positive neurones in the ARH of OCM mice, whereas no significant changes in food intake and pSTAT3 neurones were found in leptin-treated OOM mice. The number of NPY neurones in the ARH and NTS of the OOM mice was significantly higher than that of OCM mice. The results of the present study indicate that the obese phenotype from mothers can be passed onto the subsequent generation, which is possibly associated with hypothalamic leptin resistance.

Use of multisequence 3.0-T MRI to detect severe traumatic brain injury and predict the outcome

OBJECTIVE

The aim of this study was to evaluate multisequence 3.0-T MRI in the detection of severe traumatic brain injury (sTBI) and in predicting the outcome.

METHODS

32 patients with sTBI were prospectively enrolled, and multisequence 3.0-T MRI was performed 4-8 weeks post injury. Quantitative data were recorded on each sequence. The ability to display the parenchymal lesions was compared with that of 64-slice spiral CT. The clinical and radiological results were correlated with the Glasgow Outcome Scale Extended scores 6 months after injury.

RESULTS

3.0-T MRI could display more lesions than CT, especially when the lesion was deeply located. The lesion volumes and diffuse axonal injury (DAI) scores were different between good and poor outcome groups on fluid attenuated inversion recovery (p < 0.05). The apparent diffusion coefficient (ADC) values of the splenium of the corpus callosum and brain stem were also different (p < 0.05). Patients with unfavourable outcome showed a significantly higher volume of haemorrhage on susceptibility-weighted imaging than those with favourable outcomes and had haemorrhages generally located more deeply. Logistic regression analysis revealed that the location of haemorrhage and the ADC values of the splenium of the corpus callosum were independent risk factors for poor outcome, with an overall predictive accuracy of 91.4%.

CONCLUSION

The joint use of conventional and advanced sequences of 3.0-T MRI can comprehensively detect the pathological changes occurring after sTBI. Haemorrhagic and non-haemorrhagic DAIs in deep structures strongly suggest poor outcome.

ADVANCES IN KNOWLEDGE

This article improves the understanding of advanced MRI sequences in the detection of patients with sTBI and prediction of prognosis.

Covalent modification of DNA by α, β-unsaturated aldehydes derived from lipid peroxidation: Recent progress and challenges

Oxidative stress-induced lipid peroxidation (LPO) has been associated with human physiology and pathophysiology. LPO generates an array of oxidation products and among them reactive lipid aldehydes have received intensive research attentions due to their roles in modulating functions of biomolecules through covalent modification. Thus, covalent modification of DNA by these reactive lipid electrophiles has been postulated to be partially responsible for the biological roles of LPO. In this review, we summarized recent progress and challenges in studying the roles of covalent modification of DNA including nuclear and mitochondrial DNA by reactive lipid metabolites from LPO. We focused on the novel mechanistic insights into generation of lipid aldehydes from cellular membranes especially mitochondria through LPO. Recent advances in the technological front using mass spectrometry have also been highlighted in the settings of studying DNA damage caused by LPO and its biological relevance.

A Phase II study of the efficacy and safety of rontalizumab (rhuMAb interferon-α) in patients with systemic lupus erythematosus (ROSE)

OBJECTIVES

To examine the safety and efficacy of rontalizumab, a humanised IgG1 anti-interferon α (anti-IFN-α) monoclonal antibody, in patients with moderate-to-severe systemic lupus erythematosus (SLE).

METHODS

Patients with active SLE were randomised (2:1) to 750 mg intravenous rontalizumab every 4 weeks or placebo (Part 1), and 300 mg subcutaneous rontalizumab every 2 weeks or placebo (Part 2).

BACKGROUND

Hydroxychloroquine and corticosteroids were allowed. Patients taking immunosuppressants at baseline were required per protocol to discontinue. Efficacy end points included reduction in disease activity by British Isles Lupus Disease Activity Group (BILAG)-2004 (primary), and SLE response index (SRI, secondary) at Week 24. Efficacy was also examined by an exploratory measure of IFN-regulated gene expression (interferon signature metric, ISM).

RESULTS

Patients (n=238) received rontalizumab (n=159) or placebo (n=79). At baseline, the mean Safety of Estrogens in Lupus Erythematosus National Assessment version of the SLE Disease Activity Index (SELENA-SLEDAI) score in all cohorts was ~10, and 75.6% of patients had a high ISM (ISM-High). Efficacy response rates by BILAG and SRI were similar between rontalizumab and placebo groups. However, in the exploratory subgroup of ISM-Low patients, SRI response was higher and steroid use was lower in the rontalizumab-treated patients. There was also a reduction in SELENA-SLEDAI flare index rates (HR 0.61, 0.46 to 0.81, p=0.004) in this subgroup. Adverse events were similar between placebo and rontalizumab groups.

CONCLUSIONS

The primary and secondary end points of this trial were not met in all patients or in patients with high ISM scores. In an exploratory analysis, rontalizumab treatment was associated with improvements in disease activity, reduced flares and decreased steroid use in patients with SLE with low ISM scores.

TRIAL REGISTRATION NUMBER

NCT00962832.