A novel panel of protein biomarkers for predicting response to thalidomide-based therapy in newly diagnosed multiple myeloma patients

Multiple myeloma (MM) is a heterogeneous group of disorders both genotypically and phenotypically. Response to thalidomide-based induction therapy in newly diagnosed patients varies significantly in published clinical trials. Proteomic analysis was performed on 39 newly diagnosed MM patients treated with a thalidomide-based regimen (22 responders; 17 non-responders) using immunodepletion, 2-D DIGE analysis and mass spectrometry. Zinc-α-2-glycoprotein (ZAG), vitamin D-binding protein (VDB), serum amyloid-A protein (SAA) and β-2-microglobulin (B2M) had statistically significant higher concentrations in non-responders compared to responders, while haptoglobin (Hp) had a lower concentration. ELISAs were used to validate the candidate protein biomarkers using unfractionated serum from 51 newly diagnosed MM patients (29 responders; 22 non-responders). Using logistic regression, the best possible area under the curve (AUC) was 0.96 using ZAG, VDB and SAA in combination. Leave-one-out-cross-validation (LOOCV) indicated an overall predictive accuracy of 84% with associated sensitivity and specificity values of 81.8 and 86.2%, respectively. Subsequently, 16 of 22 thalidomide-refractory patients successfully achieved complete response or very good partial response using second-line treatment suggesting that the biomarker profile is specific to thalidomide response rather than identifying patients with MM refractory to all therapies. Using a novel panel of predictive biomarkers, the feasibility of predicting response to thalidomide-based therapy in previously untreated MM has been demonstrated.     

Microenvironmental influence on pre-clinical activity of polo-like kinase inhibition in multiple myeloma: implications for clinical translation

Polo-like kinases (PLKs) play an important role in cell cycle progression, checkpoint control and mitosis. The high mitotic index and chromosomal instability of advanced cancers suggest that PLK inhibitors may be an attractive therapeutic option for presently incurable advanced neoplasias with systemic involvement, such as multiple myeloma (MM). We studied the PLK 1, 2, 3 inhibitor BI 2536 and observed potent (IC50<40 nM) and rapid (commitment to cell death <24 hrs) in vitro activity against MM cells in isolation, as well as in vivo activity against a traditional subcutaneous xenograft mouse model. Tumor cells in MM patients, however, don't exist in isolation, but reside in and interact with the bone microenvironment. Therefore conventional in vitro and in vivo preclinical assays don't take into account how interactions between MM cells and the bone microenvironment can potentially confer drug resistance. To probe this question, we performed tumor cell compartment-specific bioluminescence imaging assays to compare the preclinical anti-MM activity of BI 2536 in vitro in the presence vs. absence of stromal cells or osteoclasts. We observed that the presence of these bone marrow non-malignant cells led to decreased anti-MM activity of BI 2536. We further validated these results in an orthotopic in vivo mouse model of diffuse MM bone lesions where tumor cells interact with non-malignant cells of the bone microenvironment. We again observed that BI 2536 had decreased activity in this in vivo model of tumor-bone microenvironment interactions highlighting that, despite BI 2536's promising activity in conventional assays, its lack of activity in microenvironmental models raises concerns for its clinical development for MM. More broadly, preclinical drug testing in the absence of relevant tumor microenvironment interactions may overestimate potential clinical activity, thus explaining at least in part the gap between preclinical vs. clinical efficacy in MM and other cancers.     

Genome-wide association study identifies genetic loci associated with iron deficiency

The existence of multiple inherited disorders of iron metabolism in man, rodents and other vertebrates suggests genetic contributions to iron deficiency. To identify new genomic locations associated with iron deficiency, a genome-wide association study (GWAS) was performed using DNA collected from white men aged≥25 y and women≥50 y in the Hemochromatosis and Iron Overload Screening (HEIRS) Study with serum ferritin (SF)≤12 μg/L (cases) and iron replete controls (SF>100 μg/L in men, SF>50 μg/L in women). Regression analysis was used to examine the association between case-control status (336 cases, 343 controls) and quantitative serum iron measures and 331,060 single nucleotide polymorphism (SNP) genotypes, with replication analyses performed in a sample of 71 cases and 161 controls from a population of white male and female veterans screened at a US Veterans Affairs (VA) medical center. Five SNPs identified in the GWAS met genome-wide statistical significance for association with at least one iron measure, rs2698530 on chr. 2p14; rs3811647 on chr. 3q22, a known SNP in the transferrin (TF) gene region; rs1800562 on chr. 6p22, the C282Y mutation in the HFE gene; rs7787204 on chr. 7p21; and rs987710 on chr. 22q11 (GWAS observed P<1.51×10(-7) for all). An association between total iron binding capacity and SNP rs3811647 in the TF gene (GWAS observed P=7.0×10(-9), corrected P=0.012) was replicated within the VA samples (observed P=0.012). Associations with the C282Y mutation in the HFE gene also were replicated. The joint analysis of the HEIRS and VA samples revealed strong associations between rs2698530 on chr. 2p14 and iron status outcomes. These results confirm a previously-described TF polymorphism and implicate one potential new locus as a target for gene identification.     

The Inability of Primary School to Introduce Children to the Theory of Biological Evolution

A great number of research papers in the English literature of science education present difficulties pupils have in understanding natural selection. Studies show that children have essentialist and teleological intuitive ideas when dealing with organisms and that these biases hinder their ability to understand the theory of evolution by natural selection. Consequently, it is interesting to ascertain if and how the school education offered today deals with the problem, i.e., helps the children confront these biases. To that purpose, this study answered the two following research questions: (a) How is biological evolution presented—from the past to the present day—in the official documentation of primary school education, namely the science curricula and the textbooks of Greece? and (b) what are the conceptions held by Greek primary school teachers of the concepts of evolutionary theory and relevant issues that they have to teach? Our research found that not only are the intuitive ideas not “confronted” but they are also “affirmed” in Greek primary education. This phenomenon, as some other international studies have shown, must not be only a Greek one. A drastic change in the content and structure of primary school curricula and the training of educators is necessary in order to improve and facilitate the teaching of biological evolution.     

Mechanistic simulations of inflammation: current state and future prospects

Inflammation is a normal, robust physiological process. It can also be viewed as a complex system that senses and attempts to resolve homeostatic perturbations initiated from within the body (for example, in autoimmune disease) or from the outside (for example, in infections). Virtually all acute and chronic diseases are either driven or modulated by inflammation. The complex interplay between beneficial and harmful arms of the inflammatory response may underlie the lack of fully effective therapies for many diseases. Mathematical modeling is emerging as a frontline tool for understanding the complexity of the inflammatory response. A series of articles in this issue highlights various modeling approaches to inflammation in the larger context of health and disease, from intracellular signaling to whole-animal physiology. Here we discuss the state of this emerging field. We note several common features of inflammation models, as well as challenges and prospects for future studies.     

The Impact of Autonomic Dysfunction on Survival in Patients with Dementia with Lewy Bodies and Parkinson's Disease with Dementia

Introduction

Autonomic dysfunction is a well-known feature in neurodegenerative dementias, especially common in α-synucleinopathies like dementia with Lewy bodies and Parkinson''s disease with dementia. The most common symptoms are orthostatic hypotension, incontinence and constipation, but its relevance in clinical practice is poorly understood. There are no earlier studies addressing the influence of autonomic dysfunction on clinical course and survival. The aim of this study was to investigate the frequency of the three most common features of autonomic dysfunction and analyze how it affects survival.

Methods

Thirty patients with dementia with Lewy bodies and Parkinson''s disease with dementia were included in this prospective, longitudinal follow-up study. Presence of incontinence and constipation was recorded at baseline. Blood pressure was measured at baseline, after 3 months and after 6 months according to standardized procedures, with 5 measurements during 10 minutes after rising. Orthostatic hypotension was defined using consensus definitions and persistent orthostatic hypotension was defined as 5 or more measurements with orthostatic hypotension. Difference in survival was analyzed 36 months after baseline.

Results

There was a high frequency of persistent orthostatic blood pressure (50%), constipation (30%) and incontinence (30%). Patients with persistent orthostatic hypotension had a significantly shorter survival compared to those with no or non-persistent orthostatic hypotension (Log rank x² = 4.47, p = 0.034). Patients with constipation and/or urinary incontinence, in addition to persistent orthostatic hypotension, had a poorer prognosis compared to those with isolated persistent orthostatic hypotension or no orthostatic hypotension (Log rank x² = 6.370, p = 0.041).

Discussion

According to our findings, the identification of autonomic dysfunction seems to be of great importance in clinical practice, not only to avoid falls and other complications, but also as a possible predictor of survival.     

Ultra-structural identification of interstitial cells of Cajal in the zebrafish Danio rerio

The interstitial cells of Cajal (ICCs) are important mediators of gastrointestinal (GI) motility because of their role as pacemakers in the GI tract. In addition to their function, ICCs are also structurally distinct cells most easily identified by their ultra-structural features and expression of the tyrosine kinase receptor c-KIT. ICCs have been described in mammals, rodents, birds, reptiles, and amphibians, but there are no reports at the ultra-structural level of ICCs within the GI tract of an organism from the teleost lineage. We describe the presence of cells in the muscularis of the zebrafish intestine; these cells have similar features to ICCs in other vertebrates. The ICC-like cells are associated with the muscularis, are more electron-dense than surrounding smooth muscle cells, possess long cytoplasmic processes and mitochondria, and are situated opposing enteric nervous structures. In addition, immunofluorescent and immunoelectron-microscopic studies with antibodies targeting the zebrafish ortholog of a putative ICC marker, c-KIT (kita), showed c-kit immunoreactivity in zebrafish ICCs. Taken together, these data represent the first ultra-structural characterization of cells in the muscularis of the zebrafish Danio rerio and suggest that ICC differentiation in vertebrate evolution dates back to the teleost lineage.     

d-Propranolol protects against oxidative stress and progressive cardiac dysfunction in iron overloaded rats

d-Propranolol (d-Pro: 2-8?mg·(kg body mass)(-1)·day(-1)) protected against cardiac dysfunction and oxidative stress during 3-5?weeks of iron overload (2?mg Fe-dextran·(g body mass)(-1)·week(-1)) in Sprague-Dawley rats. At 3?weeks, hearts were perfused in working mode to obtain baseline function; red blood cell glutathione, plasma 8-isoprostane, neutrophil basal superoxide production, lysosomal-derived plasma N-acetyl-β-galactosaminidase (NAGA) activity, ventricular iron content, and cardiac iron deposition were assessed. Hearts from the Fe-treated group of rats exhibited lower cardiac work (26%) and output (CO, 24%); end-diastolic pressure rose 1.8-fold. Further, glutathione levels increased 2-fold, isoprostane levels increased 2.5-fold, neutrophil superoxide increased 3-fold, NAGA increased 4-fold, ventricular Fe increased 4.9-fold; and substantial atrial and ventricular Fe-deposition occurred. d-Pro (8?mg) restored heart function to the control levels, protected against oxidative stress, and decreased cardiac Fe levels. After 5?weeks of Fe treatment, echocardiography revealed that the following were depressed: percent fractional shortening (%FS, 31% lower); left ventricular (LV) ejection fraction (LVEF, 17%), CO (25%); and aortic pressure maximum (P(max), 24%). Mitral valve E/A declined by 18%, indicating diastolic dysfunction. Cardiac CD11b+ infiltrates were elevated. Low d-Pro (2?mg) provided modest protection, whereas 4-8?mg greatly improved LVEF (54%-75%), %FS (51%-81%), CO (43%-78%), P(max) (56%-100%), and E/A?>100%; 8?mg decreased cardiac inflammation. Since d-Pro is an antioxidant and reduces cardiac Fe uptake as well as inflammation, these properties may preserve cardiac function during Fe overload.