Combination of the MEK inhibitor pimasertib with BTK or PI3K-delta inhibitors is active in preclinical models of aggressive lymphomas.

BACKGROUND: Lymphomas are among the most common human cancers and represent the cause of death for still too many patients. The B-cell receptor with its downstream signaling pathways represents an important therapeutic target for B-cell lymphomas. Here, we evaluated the activity of the MEK1/2 inhibitor pimasertib as single agent and in combination with other targeted drugs in lymphoma preclinical models. MATERIALS AND METHODS: Cell lines derived mature B-cell lymphomas were exposed to increasing doses of pimasertib alone. Immunoblotting and gene expression profiling were performed. Combination of pimasertib with idelalisib or ibrutinib was assessed. RESULTS: Pimasertib as single agent exerted a dose-dependent antitumor activity across a panel of 23 lymphoma cell lines, although at concentrations higher than reported for solid tumors. Strong synergism was observed with pimasertib combined with the PI3K inhibitor idelalisib and the BTK inhibitor ibrutinib in cell lines derived from diffuse large B-cell lymphoma (DLBCL) and mantle cell lymphoma. The data were confirmed in an in vivo experiment treating DLBCL xenografts with pimasertib and ibrutinib. CONCLUSION: The data presented here provide the basis for further investigation of regimens including pimasertib in relapsed and refractory lymphomas.

A novel patient-derived tumorgraft model with TRAF1-ALK anaplastic large-cell lymphoma translocation.

Although anaplastic large-cell lymphomas (ALCL) carrying anaplastic lymphoma kinase (ALK) have a relatively good prognosis, aggressive forms exist. We have identified a novel translocation, causing the fusion of the TRAF1 and ALK genes, in one patient who presented with a leukemic ALK+ ALCL (ALCL-11). To uncover the mechanisms leading to high-grade ALCL, we developed a human patient-derived tumorgraft (hPDT) line. Molecular characterization of primary and PDT cells demonstrated the activation of ALK and nuclear factor kB (NFkB) pathways. Genomic studies of ALCL-11 showed the TP53 loss and the in vivo subclonal expansion of lymphoma cells, lacking PRDM1/Blimp1 and carrying c-MYC gene amplification. The treatment with proteasome inhibitors of TRAF1-ALK cells led to the downregulation of p50/p52 and lymphoma growth inhibition. Moreover, a NFkB gene set classifier stratified ALCL in distinct subsets with different clinical outcome. Although a selective ALK inhibitor (CEP28122) resulted in a significant clinical response of hPDT mice, nevertheless the disease could not be eradicated. These data indicate that the activation of NFkB signaling contributes to the neoplastic phenotype of TRAF1-ALK ALCL. ALCL hPDTs are invaluable tools to validate the role of druggable molecules, predict therapeutic responses and implement patient specific therapies.

Whole-exome sequencing in splenic marginal zone lymphoma reveals mutations in genes involved in marginal zone differentiation.

Splenic marginal zone lymphoma (SMZL) is a B-cell neoplasm whose molecular pathogenesis remains fundamentally unexplained, requiring more precise diagnostic markers. Previous molecular studies have revealed 7q loss and mutations of nuclear factor κB (NF-κB), B-cell receptor (BCR) and Notch signalling genes. We performed whole-exome sequencing in a series of SMZL cases. Results confirmed that SMZL is an entity distinct from other low-grade B-cell lymphomas, and identified mutations in multiple genes involved in marginal zone development, and others involved in NF-κB, BCR, chromatin remodelling and the cytoskeleton.

Large genomic aberrations detected by SNP array are independent prognosticators of a shorter time to first treatment in chronic lymphocytic leukemia patients with normal FISH.

BACKGROUND: Genomic complexity can predict the clinical course of patients affected by chronic lymphocytic leukemia (CLL) with a normal FISH. However, large studies are still lacking. Here, we analyzed a large series of CLL patients and also carried out the so far largest comparison of FISH versus single-nucleotide polymorphism (SNP) array in this disease. PATIENTS AND METHODS: SNP-array data were derived from a previously reported dataset. RESULTS: Seventy-seven of 329 CLL patients (23%) presented with a normal FISH. At least one large (>5 Mb) genomic aberration was detected by SNP array in 17 of 77 patients (22%); this finding significantly affected TTT. There was no correlation with the presence of TP53 mutations. In multivariate analysis, including age, Binet stage, IGHV genes mutational status and large genomic lesion, the latter three factors emerged as independent prognosticators. The concordance between FISH and SNP array varied between 84 and 97%, depending on the specific genomic locus investigated. CONCLUSIONS: SNP array detected additional large genomic aberrations not covered by the standard FISH panel predicting the outcome of CLL patients.

Clinical and molecular characterization of diffuse large B-cell lymphomas with 13q14.3 deletion.

BACKGROUND: Deletions at 13q14.3 are common in chronic lymphocytic leukemia and are also present in diffuse large B-cell lymphomas (DLBCL) but never in immunodeficiency-related DLBCL. To characterize DLBCL with 13q14.3 deletions, we combined genome-wide DNA profiling, gene expression and clinical data in a large DLBCL series treated with rituximab, cyclophosphamide, doxorubicine, vincristine and prednisone repeated every 21 days (R-CHOP21). PATIENTS AND METHODS: Affymetrix GeneChip Human Mapping 250K NspI and U133 plus 2.0 gene were used. MicroRNA (miRNA) expression was studied were by real-time PCR. Median follow-up of patients was 4.9 years. RESULTS: Deletions at 13q14.3, comprising DLEU2/MIR15A/MIR16, occurred in 22/166 (13%) cases. The deletion was wider, including also RB1, in 19/22 cases. Samples with del(13q14.3) had concomitant specific aberrations. No reduced MIR15A/MIR16 expression was observed, but 172 transcripts were significantly differential expressed. Among the deregulated genes, there were RB1 and FAS, both commonly deleted at genomic level. No differences in outcome were observed in patients treated with R-CHOP21. CONCLUSIONS: Cases with 13q14.3 deletions appear as group of DLBCL characterized by common genetic and biologic features. Deletions at 13q14.3 might contribute to DLBCL pathogenesis by two mechanisms: deregulating the cell cycle control mainly due RB1 loss and contributing to immune escape, due to FAS down-regulation.

Analysis of the host pharmacogenetic background for prediction of outcome and toxicity in diffuse large B-cell lymphoma treated with R-CHOP21.

Knowledge on the impact of pharmacogenetics in predicting outcome and toxicity in diffuse large B-cell lymphoma (DLBCL) is scant. We tested 106 consecutive DLBCL treated with R-CHOP21 for 19 single nucleotide polymorphisms (SNPs) from 15 genes potentially relevant to rituximab-CHOP (R-CHOP) pharmacogenetics. Associations of SNPs with event-free survival (EFS) and toxicity were controlled for multiple testing. Genotypic variants of nicotinamide adenine dinucleotide phosphate (NAD(P)H) oxidase p22phox (CYBA rs4673) and alpha1 class glutathione S-transferase (GSTA1 rs3957357) were independent predictors of EFS (CYBA rs4673 TT genotype: HR 2.06, P=0.038; GSTA1 rs3957357 CT/TT genotypes: HR 0.38, P=0.003), after adjusting for International Prognostic Index (IPI). CYBA rs4673 and GSTA1 rs3957357 also predicted outcome in DLBCL subgroups by IPI. Impact of SNPs on toxicity was evaluated in 658 R-CHOP21 courses utilizing generalized estimating equations. NCF4 rs1883112 was an independent predictor against hematologic (odds ratios (OR): 0.45; P=0.018), infectious (OR: 0.46; P=0.003) and cardiac toxicity (OR: 0.37; P=0.023). Overall, host SNPs affecting doxorubicin pharmacodynamics (CYBA rs4673) and alkylator detoxification (GSTA1 rs3957357) may predict outcome in R-CHOP21-treated DLBCL. Also, NCF4 rs1883112, a SNP of NAD(P)H oxidase p40phox, may have a function in protecting against hematologic and nonhematologic toxicity. These results highlight the need to improve characterization of the host genetic background for a better prognostication of DLBCL.

Evaluation of post-procedure changes in aneurysmal lumen following detachable coil-placement using multi-planar reconstruction of high-field (3.0T) magnetic resonance angiography.

BACKGROUND: Placement of detachable coil(s) for intracranial aneurysms has become one of the standard methods of management. Although detailed analysis of post-procedure changes in aneurysmal lumen is essential, technical difficulties often limit such evaluation. Development of higher magnetic field systems is steadily widening clinical usage of magnetic resonance imaging (MRI) primarily due to its significantly higher signal to noise ratio. OBJECTIVE: In this study, we evaluated a multi-planar reconstruction (MPR) technique of magnetic resonance angiography (MRA) on a 3.0T system in an attempt to develop a routine method of post-procedure evaluation following detachable coil placement. METHODS: Eleven patients with an intracranial aneurysm following placement of a Guglielmi detachable coil (GDC) participated in the study. Time of flight (TOF) magnetic resonance angiography (MRA) was obtained immediately after, and up to two years after coil embolisation utilising a GE 3.0T system. Data was analysed using standard maximum intensity projection (MIP) as well as the MPR technique and the results were compared to conventional catheter angiography. RESULTS: The study demonstrated that, compared to MIP, MPR can provide further information of alteration in aneurysm lumen, especially in analysis of: 1) jet of blood flow, 2) thrombus formation, 3) neck remnant or re-filling of blood, 4) location and shape of coils including compaction, and 5) coil protrusion into the parent artery. CONCLUSIONS: Combined MPR/MIP analysis of high-field MRA appears to be a powerful non-invasive method for evaluating GDC-treatment that can potentially replace conventional catheter angiography in many clinical situations.

Planum temporale: where spoken and written language meet.

Functional magnetic resonance imaging studies on spoken versus written language processing were performed in 20 right-handed normal volunteers on a high-field (3.0-tesla) system. The areas activated in common by both auditory (listening) and visual (reading) language comprehension paradigms were mapped onto the planum temporale (20/20), primary auditory region (2/20), superior temporal sulcus area (2/20) and planum parietale (3/20). The study indicates that the planum temporale represents a common traffic area for cortical processing which needs to access the system of language comprehension. The destruction of this area can result in comprehension deficits in both spoken and written language, i.e. a classical case of Wernicke's aphasia.

Brain strategies for reading in the second language are determined by the first language.

Brain activation associated with reading was investigated in ten normal Japanese volunteers (five highly literate in both Japanese and English) and ten American native English speakers (five highly literate in both English and Japanese) in order to determine the neuroanatomic substrates employed in reading the first language (L1), and to determine the effect of L1 on the neurosubstrates involved in reading the second language (L2). The study was performed using blood oxygenation level dependent (BOLD) contrast functional magnetic resonance imaging (fMRI) on a high-field (3.0T) system specifically optimized for fMRI. The activation patterns in Japanese subjects reading Japanese (L1) were substantially different from the patterns obtained in American subjects reading English text (L1). The activation patterns reading L2 were virtually identical to the patterns seen when reading L1 in both Japanese and English natives highly literate in both language systems. The results demonstrated that the neuroanatomical substrates underlying the cognitive processing of reading are differentially determined based on the language system. The study further indicates that the cognitive processes for reading in the second language involve the same cortical structures employed for the first language, supporting the hypothesis that the second language represents the cognitive extension of the first language.

1H magnetic resonance spectroscopic imaging of permanent focal cerebral ischemia in rat: longitudinal metabolic changes in ischemic core and rim.

The purpose of this study was to determine whether regional differences in metabolites can be seen chronologically in permanent focal cerebral ischemia using 1H magnetic resonance spectroscopic imaging (MRSI), and whether these changes reflect pathological outcome. Regional variation in metabolites after permanent focal ischemia were investigated longitudinally in rats using 1H MRSI for a total of 7 days and then compared to histopathological findings. Four hours after the induction of ischemia, N-acetyl-L-aspartate (NAA) levels in the lateral caudo-putamen and the somatosensory cortex, core ischemic regions, decreased 22 and 40%, respectively. This reduction in NAA was coupled with a marked rise in lactate. In the medial caudo-putamen, the ischemic rim, however, NAA was preserved in spite of a marked increase in lactate. By 24 h post ischemia, the levels of NAA in medial caudo-putamen (ischemic rim in caudate) also decreased significantly. However NAA in cingulated cortex (ischemic rim in cortex) decreased more gradually between 24 and 48 h. This regional difference can reflect the severity of metabolic derangement in the acute stage. After 96 h following ischemia, the levels of all metabolites detected by 1H MRSI had decreased and the levels of NAA decline reflected the severity of histopathological damage. In conclusion, the regional metabolic differences could be assessed by 1H MRSI chronologically, and the depth of NAA decline reflected histopathological changes in the chronic stage.

Independent component-cross correlation-sequential epoch (ICS) analysis of high field fMRI time series: direct visualization of dual representation of the primary motor cortex in human.

A new technique for functional magnetic resonance imaging (fMRI) time series analysis is presented. The technique referred to here as independent component-cross correlation-sequential epoch (ICS) analysis is a hybrid technique of two standard methodologies of biological signal analysis, namely, data driven methods, represented by independent component analysis, and hypothesis driven methods, represented by a general linear model. The technique successfully identified four functionally discrete areas within the primary sensorimotor cortex (SMI) in normal human subjects based on blood oxygenation level dependent (BOLD) contrast functional magnetic resonance imaging (fMRI) time series performed on a high field (3.0 T) system. Each of the four areas identified corresponded to the four physiological subdivisions of SMI, recognized in primates to be essential for voluntary hand motion, namely, 4 anterior (MI-4a) and 4 posterior (MI-4p) of the primary motor cortex, and 3a and the 'classical' (Brodmann areas 1, 2, and 3b) primary sensory cortex, respectively. ICS analysis appears to be a highly reliable and versatile technique for fMRI time series analysis.

Perceptual processing of stereopsis in humans: high-field (3.0-tesla) functional MRI study.

Cortical activation associated with stereopsis was studied in eight right-handed neurosurgeons professionally trained in stereoscopic vision. The activation map associated with viewing three-dimensional images, as contrasted to viewing the corresponding two-dimensional images of identical contents (images of MR angiography), showed consistent activation in the cortex adjacent to the intraparietal sulcus. The study further demonstrated a dominant role of the right hemisphere in perceptual processing of stereopsis in humans.

Clinical application of three-dimensional anisotropy contrast magnetic resonance axonography. Technical note.

The utility of three-dimensional anisotropy contrast (3DAC) magnetic resonance (MR) axonography, a method sensitive to neuronal fibers and their directionality, was investigated in the clinical setting using a 3-tesla MR imaging system based on a General Electric Signa platform. The study focused on healthy volunteers and patients with common structural central nervous system disorders, namely chronic infarction, brainstem cavernous hemangioma, supratentorial meningioma, and astrocytoma. Three orthogonal anisotropic diffusion-weighted images were first obtained. Three primary colors were each assigned to a diffusion-weighted image, respectively, and the images were subsequently combined into a single-color image in full-color spectrum (3DAC MR axonography image). Fiber-tract definition in the cerebral peduncle of the midbrain of healthy volunteers showed intersubject variation, with two general patterns recognized: dispersed (60% of cases) and compact (40% of cases). Pathological alterations in the fiber tracts were readily identified in cases involving wallerian degeneration of the pyramidal tract, as illustrated in the cases of chronic infarction. Displacement of major tracts, such as the medial lemniscus or corticospinal tract, as well as fiber directionality, was also easily recognized in cases of mass lesions. As an imaging method uniquely capable of providing information regarding axonal connectivity, 3DAC MR axonography appears to have promising potential for routine clinical application.

High-field (3.0 T) functional MRI sequential epoch analysis: an example for motion control analysis.

The widely accepted method of blood oxygenation level dependent functional magnetic resonance imaging (BOLD-fMRI) is a subtractive approach of state related analysis based on pictorial statistics, analogous to its predecessor, H2O(15) positron emission tomography (H2O(15)-PET). Although BOLD-fMRI has been shown to have several definite advantages over H2O(15)-PET, it has also been found to be much more artifact prone. This is primarily due to pixel misalignment of raw image data. Furthermore, similar to H2O(15)-PET, conventional means for pictorial analysis in BOLD-fMRI tends to be limited by the relatively low specificity of the observed activation. To overcome this limitation, we investigated a technique for BOLD-fMRI, sequential epoch analysis (SEA), on a high-field (3.0 T) system. The method allows for experimental designs comparable to neurophysiological techniques in primates and enables determination of activation of a selected cerebral cortical region of interest corresponding to a specific task. Utilizing SEA, we successfully identified a specific area within the premotor cortex which is activated complementary to the contralateral hand motion. The findings have strong implications regarding the neurological substrate responsible for the well described clinical phenomenon of physiological mirror movements in infants. The current study validated SEA BOLD-fMRI on a high-field system as a complementary method in the pictorial analysis of conventional fMRI, effectively offsetting the inherent problems of the conventional method, principally pixel misalignment and the relatively low specificity of the observed activation.

'Musical brain' revealed by high-field (3 Tesla) functional MRI.

The cortical areas subserving music literacy were investigated using high-field (3 Tesla) functional magnetic resonance imaging (fMRI). The activation pattern associated specifically with music score reading was compared with that associated with reading text in a subject's primary and secondary language. While the areas of activation were predominantly identical for all three reading modalities, there were areas within the occipital cortex activated exclusively by music score reading. Grand analysis of the activation patterns of eight pianists unequivocally identified that the principal cortical area needed for music literacy is the cortex flanking the right transverse occipital sulcus (musical brain).

Computed tomography-negative acute thalamic hematoma.

A case of acute thalamic hematoma not detected by computed tomography (CT) but unequivocally diagnosed by magnetic resonance imaging (MRI) is presented. A 79-year-old woman presented with acute left hemiparesis. The results of CT obtained on admission as well as on the seventh hospital day were negative for a hematoma. By contrast, serial MRIs exhibited chronological changes in the relaxation properties characteristics of acute hematoma in the thalamus. The case illustrates that contrary to widespread practice, CT cannot absolutely be relied on for the detection of acute intracerebral hematoma.

Aldose reductase and sorbitol dehydrogenase activities in diabetic brain: in vivo kinetic studies using 19F 3-FDG NMR in rats.

The effects of diabetes mellitus on the kinetic constants of aldose reductase and sorbitol dehydrogenase in rat brain were investigated non-invasively in vivo using the 3-fluoro-3-deoxy-D-glucose (3-FDG) 19-fluorine (19F) nuclear magnetic resonance (NMR) method. While forward flux or both aldose reductase and sorbitol dehydrogenase (k1 and k2) were significantly increased, there was no corresponding increase in reverse flux (k3 and k4), and leakage of fructose (k5) was negligible. These findings indicate that the enzymatic kinetics of aldose reductase sorbitol (ARS) in diabetic brain undergo alteration favoring intracellular sorbitol and fructose accumulation, the frequently implicated biochemical basis of diabetic complications.

Magnetic resonance axonography of the rat spinal cord: postmortem effects.

The recent development of magnetic resonance (MR) axonography, which uses three-dimensional anisotropy contrast (3DAC), a new algorithm for the treatment of an apparent diffusion tensor, has provided an unprecedented opportunity for visualizing the anatomical details of the spinal cord in live animals. In this study, the authors investigated the sensitivity of the 3DAC method in detecting pathological conditions by obtaining chronological MR axonography of the rat spinal cord immediately after induction of cardiac arrest. The results clearly demonstrated that 3DAC is highly sensitive to any perturbation of physiological conditions. Trichromatic coefficient analyses indicated postmortem changes observed pictorially are indeed due to loss of anisotropy. The study further indicated the presence of at least two independent factors responsible for observed physiological anisotropy. Considering its rather simple implementation process and high anatomical resolution as well as its sensitivity to pathological alteration, MR axonography based on the 3DAC method appears to be the ideal noninvasive imaging technique for assessment of the spinal cord in biomedicine.

Guanidinoethane sulfate is neuroprotective towards delayed CA1 neuronal death in gerbils.

The potential neuroprotective effects of guanidinoethane sulfate (GES) on delayed neuronal death of hippocampal CA1 neurons were investigated using a gerbil model of forebrain ischemia. Neuronal densities of CA1 neurons in the saline control group (255.1 +/- 11.7 cells/mm) and guanidinoethane sulfate pretreated control group (249.0 +/- 9.4 cells/mm) showed no significant differences. By contrast, in animals subjected to ischemia, CA1 neurons of the guanidinoethane sulfate pretreated group showed a significantly higher number of surviving neurons (61.1 +/- 55.11 cells/mm) compared to the saline group (17.75 +/- 12.73 cells/mm) (p < 0.05, t-test). The study indicated that although partial, guanidinoethane sulfate is neuroprotective towards gerbil hippocampal CA1 neurons against ischemic insult.