Lawrence Recht, MD

All Publications

• Visualization of rodent brain tumor angiogenesis and effects of antiangiogenic treatment using 3D Delta R-2-mu MRA ANGIOGENESIS Lin, C., Siow, T. Y., Lin, M., Hsu, Y., Tung, Y., Jang, T., Recht, L., Chang, C. 2013; 16 (4): 785-793

  Abstract

  Understanding of structural and functional characteristics of the vascular microenvironment in gliomas and the impact of antiangiogenic treatments is essential for developing better therapeutic strategies. Although a number of methods exist in which this process can be studied experimentally, no single noninvasive test has the capacity to provide information concerning both microvascular function and morphology. The purpose of present study is to demonstrate the feasibility of using a novel three-dimensional ΔR2-based microscopic magnetic resonance angiography (3D ΔR2-μMRA) technique for longitudinal imaging of tumor angiogenesis and monitoring the effects of antiangiogenic treatment in rodent brain tumor models. Using 3D ΔR2-μMRA, a generally consistent early pattern of vascular development in gliomas was revealed, in which a single feeding vessel was visualized first (arteriogenesis), followed by sprouting angiogenesis. Considerable variability of the tumor-associated vasculature was then noted at later stages of tumor evolution. ΔR2-μMRA revealed that anti-vascular endothelial growth factor treatment induced a rapid and significant alteration of the intratumoral angiogenic phenotype. In summary, 3D ΔR2-μMRA enables high-resolution visualization of tumor-associated vessels while simultaneously providing functional information on the tumor microvasculature. It can serve as a useful tool for monitoring both the temporal evolution of tumor angiogenesis and the impact of antiangiogenic therapies.

  View details for DOI 10.1007/s10456-013-9355-8

  View details for Web of Science ID 000324326900005

  View details for PubMedID 23736837

• Visualization of rodent brain tumor angiogenesis and effects of antiangiogenic treatment using 3D Delta R-2-mu MRA ANGIOGENESIS Lin, C., Siow, T. Y., Lin, M., Hsu, Y., Tung, Y., Jang, T., Recht, L., Chang, C. 2013; 16 (4): 785-793

  Abstract

  Understanding of structural and functional characteristics of the vascular microenvironment in gliomas and the impact of antiangiogenic treatments is essential for developing better therapeutic strategies. Although a number of methods exist in which this process can be studied experimentally, no single noninvasive test has the capacity to provide information concerning both microvascular function and morphology. The purpose of present study is to demonstrate the feasibility of using a novel three-dimensional ΔR2-based microscopic magnetic resonance angiography (3D ΔR2-μMRA) technique for longitudinal imaging of tumor angiogenesis and monitoring the effects of antiangiogenic treatment in rodent brain tumor models. Using 3D ΔR2-μMRA, a generally consistent early pattern of vascular development in gliomas was revealed, in which a single feeding vessel was visualized first (arteriogenesis), followed by sprouting angiogenesis. Considerable variability of the tumor-associated vasculature was then noted at later stages of tumor evolution. ΔR2-μMRA revealed that anti-vascular endothelial growth factor treatment induced a rapid and significant alteration of the intratumoral angiogenic phenotype. In summary, 3D ΔR2-μMRA enables high-resolution visualization of tumor-associated vessels while simultaneously providing functional information on the tumor microvasculature. It can serve as a useful tool for monitoring both the temporal evolution of tumor angiogenesis and the impact of antiangiogenic therapies.

  View details for DOI 10.1007/s10456-013-9355-8

  View details for Web of Science ID 000324326900005

  View details for PubMedID 23736837

• Central Nervous System Cancers Clinical Practice Guidelines in Oncology JOURNAL OF THE NATIONAL COMPREHENSIVE CANCER NETWORK Nabors, L. B., Ammirati, M., Bierman, P. J., Brem, H., Butowski, N., Chamberlain, M. C., DeAngelis, L. M., Fenstermaker, R. A., Friedman, A., Gilbert, M. R., Hesser, D., Holdhoff, M., Junck, L., Lawson, R., Loeffler, J. S., Maor, M. H., Moots, P. L., Morrison, T., Mrugala, M. M., Newton, H. B., Portnow, J., Raizer, J. J., Recht, L., Shrieve, D. C., Sills, A. K., Tran, D., Tran, N., Vrionis, F. D., Wen, P. Y., McMillian, N., Ho, M. 2013; 11 (9): 1114-1151

  View details for Web of Science ID 000324310800008

• Simultaneous perfusion and permeability measurements using combined spin- and gradient-echo MRI. Journal of cerebral blood flow and metabolism Schmiedeskamp, H., Andre, J. B., Straka, M., Christen, T., Nagpal, S., Recht, L., Thomas, R. P., Zaharchuk, G., Bammer, R. 2013; 33 (5): 732-743

  Abstract

  The purpose of this study was to estimate magnetic resonance imaging-based brain perfusion parameters from combined multiecho spin-echo and gradient-echo acquisitions, to correct them for T1-, T2-, and -related contrast agent (CA) extravasation effects, and to simultaneously determine vascular permeability. Perfusion data were acquired using a combined multiecho spin- and gradient-echo (SAGE) echo-planar imaging sequence, which was corrected for CA extravasation effects using pharmacokinetic modeling. The presented method was validated in simulations and brain tumor patients, and compared with uncorrected single-echo and multiecho data. In the presence of CA extravasation, uncorrected single-echo data resulted in underestimated CA concentrations, leading to underestimated single-echo cerebral blood volume (CBV) and mean transit time (MTT). In contrast, uncorrected multiecho data resulted in overestimations of CA concentrations, CBV, and MTT. The correction of CA extravasation effects resulted in CBV and MTT estimates that were more consistent with the underlying tissue characteristics. Spin-echo perfusion data showed reduced large-vessel blooming effects, facilitating better distinction between increased CBV due to active tumor progression and elevated CBV due to the presence of cortical vessels in tumor proximity. Furthermore, extracted permeability parameters were in good agreement with elevated T1-weighted postcontrast signal values.

  View details for DOI 10.1038/jcbfm.2013.10

  View details for PubMedID 23462570

• Metabolic response of glioma to dichloroacetate measured in vivo by hyperpolarized C-13 magnetic resonance spectroscopic imaging NEURO-ONCOLOGY Park, J. M., Recht, L. D., Josan, S., Merchant, M., Jang, T., Yen, Y., Hurd, R. E., Spielman, D. M., Mayer, D. 2013; 15 (4): 433-441

  Abstract

  The metabolic phenotype that derives disproportionate energy via glycolysis in solid tumors, including glioma, leads to elevated lactate labeling in metabolic imaging using hyperpolarized [1-(13)C]pyruvate. Although the pyruvate dehydrogenase (PDH)-mediated flux from pyruvate to acetyl coenzyme A can be indirectly measured through the detection of carbon-13 ((13)C)-labeled bicarbonate, it has proven difficult to visualize (13)C-bicarbonate at high enough levels from injected [1-(13)C]pyruvate for quantitative analysis in brain. The aim of this study is to improve the detection of (13)C-labeled metabolites, in particular bicarbonate, in glioma and normal brain in vivo and to measure the metabolic response to dichloroacetate, which upregulates PDH activity.An optimized protocol for chemical shift imaging and high concentration of hyperpolarized [1-(13)C]pyruvate were used to improve measurements of lactate and bicarbonate in C6 glioma-transplanted rat brains. Hyperpolarized [1-(13)C]pyruvate was injected before and 45 min after dichloroacetate infusion. Metabolite ratios of lactate to bicarbonate were calculated to provide improved metrics for characterizing tumor metabolism.Glioma and normal brain were well differentiated by lactate-to-bicarbonate ratio (P = .002, n = 5) as well as bicarbonate (P = .0002) and lactate (P = .001), and a stronger response to dichloroacetate was observed in glioma than in normal brain.Our results clearly demonstrate for the first time the feasibility of quantitatively detecting (13)C-bicarbonate in tumor-bearing rat brain in vivo, permitting the measurement of dichloroacetate-modulated changes in PDH flux. The simultaneous detection of lactate and bicarbonate provides a tool for a more comprehensive analysis of glioma metabolism and the assessment of metabolic agents as anti-brain cancer drugs.

  View details for DOI 10.1093/neuonc/nos319

  View details for Web of Science ID 000316965600005

  View details for PubMedID 23328814

  View details for PubMedCentralID PMC3607261

• ETIRINOTECAN PEGOL DNA Topoisomerase 1 Inhibitor Oncolytic DRUGS OF THE FUTURE Nagpal, S., Recht, L. D. 2013; 38 (4): 227-233

  View details for DOI 10.1358/dof.2013.38.4.1939287

  View details for Web of Science ID 000317927900003

• Steroid-Sparing Effect of Corticorelin Acetate in Peritumoral Cerebral Edema Is Associated With Improvement in Steroid-Induced Myopathy JOURNAL OF CLINICAL ONCOLOGY Recht, L., Mechtler, L. L., Wong, E. T., O'Connor, P. C., Rodda, B. E. 2013; 31 (9): 1182-1187

  Abstract

  To compare the safety and efficacy of corticorelin acetate (CrA) and placebo in patients with malignant brain tumors requiring chronic administration of dexamethasone (DEX) to control the signs and symptoms of peritumoral brain edema (PBE).Prospective, randomized, double-blind study of 200 patients with PBE on a stable dose of DEX. Initially, DEX dose was decreased by 50% over a 2-week period and then held at this level for 3 weeks. The primary end point was the proportion of patients who responded to treatment-patients who achieved a ≥ 50% DEX reduction from baseline and achieved stable or improved neurologic examination score and Karnofsky performance score at week 2, and then continued to respond at week 5.One hundred patients received subcutaneous injections of 1 mg twice per day of CrA and 100 patients received placebo for the duration of the study period. Although results did not attain statistical significance (at the P < .05 level), a clinically important difference in the proportion of responders between the CrA group (57.0%) and the placebo group (46.0%; P = .12) was observed. In addition, the maximum percent reduction in DEX dose achieved during the double-blind 12-week study was significantly greater in the CrA group (62.7%) than in placebo group (51.4%; P < .001). Patients receiving CrA demonstrated an improvement in myopathy and were less likely to develop signs of Cushing syndrome.CrA enables a reduction in steroid requirement for patients with PBE and is associated with a reduction in the incidence and severity of common steroid adverse effects, including myopathy.

  View details for DOI 10.1200/JCO.2012.43.9455

  View details for PubMedID 23382470

• Thrombin-cleaved Fragments of Osteopontin Are Overexpressed in Malignant Glial Tumors and Provide a Molecular Niche with Survival Advantage JOURNAL OF BIOLOGICAL CHEMISTRY Yamaguchi, Y., Shao, Z., Sharif, S., Du, X., Myles, T., Merchant, M., Harsh, G., Glantz, M., Recht, L., Morser, J., Leung, L. L. 2013; 288 (5): 3097-3111

  Abstract

  Osteopontin (OPN), which is highly expressed in malignant glioblastoma (GBM), possesses inflammatory activity modulated by proteolytic cleavage by thrombin and plasma carboxypeptidase B2 (CPB2) at a highly conserved cleavage site. Full-length OPN (OPN-FL) was elevated in cerebrospinal fluid (CSF) samples from all cancer patients compared with noncancer patients. However, thrombin-cleaved OPN (OPN-R) and thrombin/CPB2-double-cleaved OPN (OPN-L) levels were markedly increased in GBM and non-GBM gliomas compared with systemic cancer and noncancer patients. Cleaved OPN constituted ∼23 and ∼31% of the total OPN in the GBM and non-GBM CSF samples, respectively. OPN-R was also elevated in GBM tissues. Thrombin-antithrombin levels were highly correlated with cleaved OPN, but not OPN-FL, suggesting that the cleaved OPN fragments resulted from increased thrombin and CPB2 in this extracellular compartment. Levels of VEGF and CCL4 were increased in CSF of GBM and correlated with the levels of cleaved OPN. GBM cell lines were more adherent to OPN-R and OPN-L than OPN-FL. Adhesion to OPN altered gene expression, in particular genes involved with cellular processes, cell cycle regulation, death, and inflammation. OPN and its cleaved forms promoted motility of U-87 MG cells and conferred resistance to apoptosis. Although functional mutation of the RGD motif in OPN largely abolished these functions, OPN(RAA)-R regained significant cell binding and signaling function, suggesting that the SVVYGLR motif in OPN-R may substitute for the RGD motif if the latter becomes inaccessible. OPN cleavage contributes to GBM development by allowing more cells to bind in niches where they acquire anti-apoptotic properties.

  View details for DOI 10.1074/jbc.M112.362954

  View details for Web of Science ID 000314397900019

  View details for PubMedID 23204518

  View details for PubMedCentralID PMC3561533

• Advances in the management of glioblastoma: the role of temozolomide and MGMT testing. Clinical pharmacology : advances and applications Thomas, R. P., Recht, L., Nagpal, S. 2013; 5: 1-9

  Abstract

  Glioblastoma (GB) is one of the most lethal forms of cancer, with an invasive growth pattern that requires the use of adjuvant therapies, including chemotherapy and radiation, to prolong survival. Temozolomide (TMZ) is an oral chemotherapy with a limited side effect profile that has become the standard of care in GB treatment. While TMZ has made an impact on survival, tumor recurrence and TMZ resistance remain major challenges. Molecular markers, such as O6-methylguanine-DNA methyltransferase methylation status, can be helpful in predicting tumor response to TMZ, and therefore guides clinical decision making. This review will discuss the epidemiology and possible genetic underpinnings of GB, how TMZ became the standard of care for GB patients, the pharmacology of TMZ, the practical aspects of using TMZ in clinic, and how molecular diagnostics - particularly the use of O6-methylguanine-DNA methyltransferase status - affect clinical management.

  View details for DOI 10.2147/CPAA.S26586

  View details for PubMedID 23293540

• Alterations in Cerebrospinal Fluid Proteins in a Presymptomatic Primary Glioma Model PLOS ONE Whitin, J. C., Jang, T., Merchant, M., Yu, T. T., Lau, K., Recht, B., Cohen, H. J., Recht, L. 2012; 7 (11)

  Abstract

  Understanding the early relationship between brain tumor cells and their environment could lead to more sensitive biomarkers and new therapeutic strategies. We have been using a rodent model of neurocarcinogenesis in which all animals develop brain tumors by six months of age to establish two early landmarks in glioma development: the appearance of a nestin(+) cell at thirty days of age and the appearance of cellular hyperplasia between 60 and 120 days of age. We now report an assessment of the CSF proteome to determine the changes in protein composition that occur during this period.Nestin(+) cell clusters and microtumors were assessed in 63 ethylnitrosourea-exposed rats on 30, 60, and 90 days of age. CSF was obtained from the cisterna magna from 101 exposed and control rats at 30, 60, and 90 days and then analyzed using mass spectrometry. Differentially expressed peaks were isolated and identified.Nestin(+) cells were noted in all ethylnitrosourea-exposed rats assessed pathologically. Small microtumors were noted in 0%, 18%, and 67% of 30-, 60-, and 90-day old rats, respectively (p<0.05, Chi square). False Discovery Rate analysis of peak intensities showed that the number of true discoveries with p<0.05 increased markedly with increasing age. Isolation and identification of highly differentially detected proteins at 90 days of age revealed increases in albumin and a fragment of α1 macroglobulin and alterations in glutathionylated transthyretin.The presence of increased albumin, fragments of cerebrospinal fluid proteins, and glutathione breakdown in temporal association with the development of cellular hyperplasia, suggests that, similar to many other systemic cancers, inflammation and oxidative stress is playing an important early role in the host's response to brain tumor development and may be involved in affecting the early growth of brain tumor.

  View details for DOI 10.1371/journal.pone.0049724

  View details for Web of Science ID 000311333800047

  View details for PubMedID 23185417

  View details for PubMedCentralID PMC3501526

• Metabolite kinetics in C6 rat glioma model using magnetic resonance spectroscopic imaging of hyperpolarized [1-13C]pyruvate MAGNETIC RESONANCE IN MEDICINE Park, J. M., Josan, S., Jang, T., Merchant, M., Yen, Y., Hurd, R. E., Recht, L., Spielman, D. M., Mayer, D. 2012; 68 (6): 1886-1893

  Abstract

  In addition to an increased lactate-to-pyruvate ratio, altered metabolism of a malignant glioma can be further characterized by its kinetics. Spatially resolved dynamic data of pyruvate and lactate from C6-implanted female Sprague-Dawley rat brain were acquired using a spiral chemical shift imaging sequence after a bolus injection of a hyperpolarized [1-(13)C]pyruvate. Apparent rate constants for the conversion of pyruvate to lactate in three different regions (glioma, normal appearing brain, and vasculature) were estimated based on a two-site exchange model. The apparent conversion rate constant was 0.018 ± 0.004 s(-1) (mean ± standard deviation, n = 6) for glioma, 0.009 ± 0.003 s(-1) for normal brain, and 0.005 ± 0.001 s(-1) for vasculature, whereas the lactate-to-pyruvate ratio, the metabolic marker used to date to identify tumor regions, was 0.36 ± 0.07 (mean ± SD), 0.24 ± 0.07, and 0.12 ± 0.02 for glioma, normal brain, and vasculature, respectively. The data suggest that the apparent conversion rate better differentiate glioma from normal brain (P = 0.001, n = 6) than the lactate-to-pyruvate ratio (P = 0.02).

  View details for DOI 10.1002/mrm.24181

  View details for Web of Science ID 000311398600022

  View details for PubMedID 22334279

  View details for PubMedCentralID PMC3376665

• Preliminary use of differential scanning calorimetry of cerebrospinal fluid for the diagnosis of glioblastoma multiforme JOURNAL OF NEURO-ONCOLOGY Chagovetz, A. A., Jensen, R. L., Recht, L., Glantz, M., Chagovetz, A. M. 2011; 105 (3): 499-506

  Abstract

  Thermal stability signatures of complex molecule interaction in biological fluids can be measured using a new approach called differential scanning calorimetry (DSC). The thermal stability of plasma proteome has been described previously as a method of producing a disease-specific "signature," termed thermogram, in several neoplastic and autoimmune diseases. We describe the preliminary use of DSC performed on cerebrospinal fluid (CSF) as a diagnostic tool for the identification of patients with glioblastoma multiforme (GBM). Samples of CSF from nine patients with confirmed GBM were evaluated using DSC, and the thermogram signatures evaluated. These thermograms were compared with thermograms of CSF taken from patients with non-neoplastic conditions such as head trauma, hydrocephalus, or CSF leak. Further analysis was also performed on CSF from patients who had non-GBM neoplastic conditions such as carcinomatosis meningitis or central nervous system lymphoma or leukemia. The DSC thermograms of CSF of the patients with GBM were significantly different when compared with other neoplastic and non-neoplastic cases. The melting temperature of the major transition was shifted by 5°C, which makes it easily distinguishable from control cases. Our results are very preliminary, but it appears that the DSC of CSF has potential utility in diagnostics and monitoring disease progression in GBM patients.

  View details for DOI 10.1007/s11060-011-0630-5

  View details for Web of Science ID 000297803100005

  View details for PubMedID 21720810

• Chemerin158K Protein Is the Dominant Chemerin Isoform in Synovial and Cerebrospinal Fluids but Not in Plasma JOURNAL OF BIOLOGICAL CHEMISTRY Zhao, L., Yamaguchi, Y., Sharif, S., Du, X., Song, J. J., Lee, D. M., Recht, L. D., Robinson, W. H., Morser, J., Leung, L. L. 2011; 286 (45): 39520-39527

  Abstract

  Chemerin is a chemoattractant involved in immunity that may also function as an adipokine. Chemerin circulates as an inactive precursor (chem163S), and its activation requires proteolytic cleavages at its C terminus, involving proteases involved in coagulation, fibrinolysis, and inflammation. However, the key proteolytic steps in prochemerin activation in vivo remain to be established. Previously, we have shown that C-terminal cleavage of chem163S by plasmin to chem158K, followed by a carboxypeptidase cleavage, leads to the most active isoform, chem157S. To identify and quantify the in vivo chemerin isoforms in biological specimens, we developed specific ELISAs for chem163S, chem158K, and chem157S, using antibodies raised against peptides from the C terminus of the different chemerin isoforms. We found that the mean plasma concentrations of chem163S, chem158K, and chem157S were 40 ± 7.9, 8.1 ± 2.9, and 0.7 ± 0.8 ng/ml, respectively. The total level of cleaved and noncleaved chemerins in cerebrospinal fluids was ∼10% of plasma levels whereas it was elevated ∼2-fold in synovial fluids from patients with arthritis. On the other hand, the fraction of cleaved chemerins was much higher in synovial fluid and cerebrospinal fluid samples than in plasma (∼75%, 50%, and 18% respectively). Chem158K was the dominant chemerin isoform, and it was not generated by ex vivo processing, indicating that cleavage of prochemerin at position Lys-158, whether by plasmin or another serine protease, represents a major step in prochemerin activation in vivo. Our study provides the first direct evidence that chemerin undergoes extensive proteolytic processing in vivo, underlining the importance of measuring individual isoforms.

  View details for DOI 10.1074/jbc.M111.258954

  View details for PubMedID 21930706

• Treatment and Prophylaxis of Hematologic Malignancy in the Central Nervous System CURRENT TREATMENT OPTIONS IN NEUROLOGY Nagpal, S., Recht, L. 2011; 13 (4): 400-412

  Abstract

  OPINION STATEMENT: Central nervous system (CNS) involvement is a serious, and frequently fatal, complication of acute leukemias and very aggressive lymphomas. In patients with no evidence of CNS involvement at the time of diagnosis, the decision to include CNS prophylaxis in the treatment regimen should be based on cytologic diagnosis and other risk factors. Patients with a risk of CNS relapse greater than 10% should receive CNS prophylaxis with high-dose systemic chemotherapy, intrathecal therapy, radiation, or a combination thereof. The most commonly used systemic and intrathecal chemotherapies are methotrexate and cytarabine. Liposomal cytarabine, which increases CNS bioavailability and decreases the number of lumbar punctures needed, is our preference for intrathecal therapy. We usually reserve radiation therapy for patients who may not tolerate other forms of CNS prophylaxis. Patients with evidence of CNS involvement, either at diagnosis or relapse, should be treated until CNS disease clearance or dose-limiting toxicity is reached. Recent studies suggest that autologous stem cell transplantation may offer longer survivals for patients with CNS involvement and should be considered for patients who can tolerate the procedure. The use of rituximab in CNS prophylaxis and treatment has not yet been clearly delineated, but initial reports indicate that this agent and others may soon be available as an effective and tolerable CNS-directed therapy for lymphomas.

  View details for DOI 10.1007/s11940-011-0128-7

  View details for Web of Science ID 000292402500007

  View details for PubMedID 21484261

• 5 '-AMP-activated protein kinase activity is elevated early during primary brain tumor development in the rat INTERNATIONAL JOURNAL OF CANCER Jang, T., Calaoagan, J. M., Kwon, E., Samuelsson, S., Recht, L., Laderoute, K. R. 2011; 128 (9): 2230-2239

  Abstract

  We found that adenosine 5'-monophosphate-activated protein kinase (AMPK), which is considered the "fuel sensor" of mammalian cells because it directly responds to the depletion of the fuel molecule ATP, is strongly activated by tumor-like hypoxia and glucose deprivation. We also observed abundant AMPK activity in tumor cells in vivo, using subcutaneous tumor xenografts prepared from cells transformed with oncogenic H-Ras. Such rapidly growing transplants of tumor cells, however, represent fully developed tumors that naturally contain energetically stressed microenvironments that can activate AMPK. Therefore, to investigate the induction of AMPK activity during experimental tumorigenesis, we used an established model of brain tumor (glioma) development in the offspring of rats exposed prenatally to the mutagen N-ethyl-N-nitrosourea. We observed that immunostaining for a specific readout of AMPK activity (AMPK-dependent phosphorylation of acetyl-CoA carboxylase) was prominent during N-ethyl-N-nitrosourea-initiated neurocarcinogenesis, from the occurrence of early hyperplasia (microtumors) to the emergence of large gliomas. Moreover, we observed that immunostaining for activating phosphorylation of AMPK correlated with the same stages of glioma development, notably in mitotic tumor cells in which the signal showed punctate as well as cytoplasmic patterns associated with spindle formation. Based on these observations, we propose that neurocarcinogenesis requires AMPK-dependent regulation of cellular energy metabolism.

  View details for DOI 10.1002/ijc.25558

  View details for Web of Science ID 000288176600024

  View details for PubMedID 20635388

  View details for PubMedCentralID PMC2992079

• Central Nervous System Cancers JOURNAL OF THE NATIONAL COMPREHENSIVE CANCER NETWORK Brem, S. S., Bierman, P. J., Brem, H., Butowski, N., Chamberlain, M. C., Chiocca, E. A., DeAngelis, L. M., Fenstermaker, R. A., Friedman, A., Gilbert, M. R., Hesser, D., Junck, L., Linette, G. P., Loeffler, J. S., Maor, M. H., Michael, M., Moots, P. L., Morrison, T., Mrugala, M., Nabors, L. B., Newton, H. B., Portnow, J., Raizer, J. J., Recht, L., Shrieve, D. C., Sills, A. K., Vrionis, F. D., Wen, P. Y. 2011; 9 (4): 352-400

  View details for Web of Science ID 000289121700003

  View details for PubMedID 21464144

• Time-lapse imaging of disease progression in deep brain areas using fluorescence microendoscopy NATURE MEDICINE Barretto, R. P., Ko, T. H., Jung, J. C., Wang, T. J., Capps, G., Waters, A. C., Ziv, Y., Attardo, A., Recht, L., Schnitzer, M. J. 2011; 17 (2): 223-U120

  Abstract

  The combination of intravital microscopy and animal models of disease has propelled studies of disease mechanisms and treatments. However, many disorders afflict tissues inaccessible to light microscopy in live subjects. Here we introduce cellular-level time-lapse imaging deep within the live mammalian brain by one- and two-photon fluorescence microendoscopy over multiple weeks. Bilateral imaging sites allowed longitudinal comparisons within individual subjects, including of normal and diseased tissues. Using this approach, we tracked CA1 hippocampal pyramidal neuron dendrites in adult mice, revealing these dendrites' extreme stability and rare examples of their structural alterations. To illustrate disease studies, we tracked deep lying gliomas by observing tumor growth, visualizing three-dimensional vasculature structure and determining microcirculatory speeds. Average erythrocyte speeds in gliomas declined markedly as the disease advanced, notwithstanding significant increases in capillary diameters. Time-lapse microendoscopy will be applicable to studies of numerous disorders, including neurovascular, neurological, cancerous and trauma-induced conditions.

  View details for DOI 10.1038/nm.2292

  View details for Web of Science ID 000286969900032

  View details for PubMedID 21240263

• Bevacizumab improves quality of life in patients with recurrent glioblastoma. Chemotherapy research and practice Nagpal, S., Harsh, G., Recht, L. 2011; 2011: 602812-?

  Abstract

  Objective. To quantify the benefits in survival and quality of life in patients receiving bevacizumab (BEV) for recurrent glioblastoma (GBM). Methods. This is a retrospective study of 40 adult patients with recurrent GBM treated between 2005 and 2009 at a single institution. All patients had initial treatment with surgery, radiation, and concurrent temozolomide, then monthly temozolomide. Over 250 charts were screened. Sufficient data was available for 20 patients treated with BEV and 20 patients who did not receive BEV at the time of recurrence. The independent living score (ILS), designed to reward long-term independent survival, was calculated for each patient. Results. The mean ILS was nearly double in the BEV group compared to the No-BEV group (15.0 versus 8.2, P = 0.002, t-test). Two months after initiation of therapy, the median steroid dose dropped by over 90% in patients treated with BEV, but doubled in the NoBEV group. Median survival from the time of recurrence was significantly affected: 10.6 months in the BEV group versus 4.2 months (P < 0.001, log rank survival) in the NoBEV group. Conclusions. BEV increases independent living and lengthens overall survival after GBM recurrence. Reduction in steroid dose may contribute to prolonged independence.

  View details for DOI 10.1155/2011/602812

  View details for PubMedID 22312554

  View details for PubMedCentralID PMC3263615

• VERUBULIN HYDROCHLORIDE Apoptosis Inducer Vascular Disrupting Agent Oncolytic DRUGS OF THE FUTURE Thomas, P., Recht, L. 2010; 35 (12): 993-997

  View details for DOI 10.1358/dof.2010.35.12.1543302

  View details for Web of Science ID 000289872400003

• Treatment and Prevention of Secondary CNS Lymphoma SEMINARS IN NEUROLOGY Nagpal, S., Glantz, M. J., Recht, L. 2010; 30 (3): 263-272

  Abstract

  Central nervous system (CNS) involvement in non-Hodgkin lymphoma is a serious, potentially preventable complication that can occur in 5 to 10% of patients. Its occurrence is directly correlated with pathologic aggressiveness and ranges from less than 3% in the indolent, less-aggressive histologies to as high as 50% in the very aggressive ones such as Burkitt lymphoma. Aggressive treatment once detected can improve neurologic outcome, but because it is often associated with contemporaneous systemic relapse, is rarely associated with long-term survival. Preventing its occurrence, therefore, remains an important goal of initial treatment. Despite there being some suggestive evidence that the addition of systemic rituximab and several intracerebrospinal fluid chemotherapy regimens may have decreased the incidence of CNS involvement, both optimal selection of those patients who should receive prophylaxis as well as the best prophylactic regimen remain active areas of investigation.

  View details for DOI 10.1055/s-0030-1255222

  View details for Web of Science ID 000279572600007

  View details for PubMedID 20577933

• Murine Embryonic Stem Cell-Derived Pyramidal Neurons Integrate into the Cerebral Cortex and Appropriately Project Axons to Subcortical Targets JOURNAL OF NEUROSCIENCE Ideguchi, M., Palmer, T. D., Recht, L. D., Weimann, J. M. 2010; 30 (3): 894-904

  Abstract

  Although embryonic stem (ES) cells have been induced to differentiate into diverse neuronal cell types, the production of cortical projection neurons with the correct morphology and axonal connectivity has not been demonstrated. Here, we show that in vitro patterning is critical for generating neural precursor cells (ES-NPCs) competent to form cortical pyramidal neurons. During the first week of neural induction, these ES-NPCs begin to express genes that are specific for forebrain progenitors; an additional week of differentiation produces mature neurons with many features of cortical pyramidal neurons. After transplantation into the murine cerebral cortex, these specified ES-NPCs manifest the correct dendritic and axonal connectivity for their areal location. ES-NPCs transplanted into the deep layers of the motor cortex differentiate into layer 5 pyramidal neurons and extend axons to distant subcortical targets such as the pons and as far caudal as the pyramidal decussation and descending spinal tract and, importantly, do not extend axons to inappropriate targets such as the superior colliculus (SC). ES-NPCs transplanted into the visual cortex extend axons to the dorsal aspect of the SC and pons but avoid ventral SC and the pyramidal tract, whereas cells transplanted deep into the somatosensory cortex project axons to the ventral SC, avoiding the dorsal SC. Thus, these data establish that ES-derived cortical projection neurons can integrate into anatomically relevant circuits.

  View details for DOI 10.1523/JNEUROSCI.4318-09.2010

  View details for Web of Science ID 000273779200011

  View details for PubMedID 20089898

• Gender Disparity in the Rate of Partner Abandonment in Patients With Serious Medical Illness CANCER Glantz, M. J., Chamberlain, M. C., Liu, Q., Hsieh, C., Edwards, K. R., Van Horn, A., Recht, L. 2009; 115 (22): 5237-5242

  Abstract

  Life-threatening illness creates severe stress that may result in marital discord, separation, or divorce and may adversely impact treatment, quality of life, and survival. The few studies that are available to date have suggested that the risk of divorce is not higher in cancer patients, but to the authors' knowledge, no data exist to date that have examined the effect of gender on this rate.A total of 515 patients were prospectively identified as having either a malignant primary brain tumor (N = 214), a solid tumor with no nervous system involvement (N = 193), or multiple sclerosis (N = 108) who were married at the time of diagnosis. Basic demographic information and data regarding marital status were compiled. Patients were followed prospectively from enrollment until death or study termination.Women composed 53% of the patient population. Divorce or separation occurred at a rate similar to that reported in the literature (11.6%). There was, however, a greater than 6-fold increase in risk after diagnosis when the affected spouse was the woman (20.8% vs 2.9%; P < .001). Female gender was found to be the strongest predictor of separation or divorce in each cohort. Marriage duration at the time of illness was also correlated with separation among brain tumor patients (P = .0001). Patients with brain tumors who were divorced or separated were more likely to be hospitalized, and less likely to participate in a clinical trial, receive multiple treatment regimens, complete cranial irradiation, or die at home (P < .0001).Female gender was found to be a strong predictor of partner abandonment in patients with serious medical illness. When divorce or separation occurred, quality of care and quality of life were adversely affected.

  View details for DOI 10.1002/cncr.24577

  View details for Web of Science ID 000271564100017

  View details for PubMedID 19645027

• Understanding the Origins of Gliomas and Developing Novel Therapies: Cerebrospinal Fluid and Subventricular Zone Interplay SEMINARS IN ONCOLOGY Glantz, M., Kesari, S., Recht, L., Fleischhack, G., Van Horn, A. 2009; 36 (4): S17-S24

  Abstract

  Glioblastoma multiforme (GBM), the most common malignant primary brain tumor in adults, carries a poor prognosis, with median survival generally less than 1 year. Although initial therapy often eradicates the bulk of the tumor, disease recurrence, usually within 2 cm of the original tumor, is almost inevitable. This may be due to a failure of current therapies to eradicate viable chemotherapy- and radiotherapy-resistant neoplastic progenitor cells, which may then repopulate tumors. An increasing body of preclinical data suggests that these cells may correspond to stem cells derived from the subventricular zone (SVZ), which migrate to tumor sites and contribute to glioma growth and recurrence. Therapeutic targeting of SVZ stem cell populations via cerebrospinal fluid (CSF)-directed therapy may provide a means for limiting tumor recurrence. This approach has proved successful in the treatment of medulloblastoma, another brain tumor thought to be derived from stem cells. We discuss the rationale and design considerations for a clinical trial to evaluate the efficacy of CSF-directed therapy for preventing GBM recurrence.

  View details for DOI 10.1053/j.seminoncol.2009.05.003

  View details for Web of Science ID 000268899700003

  View details for PubMedID 19660679

• MOTEXAFIN GADOLINIUM COMBINED WITH PROMPT WHOLE BRAIN RADIOTHERAPY PROLONGS TIME TO NEUROLOGIC PROGRESSION IN NON-SMALL-CELL LUNG CANCER PATIENTS WITH BRAIN METASTASES: RESULTS OF A PHASE III TRIAL INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS Mehta, M. P., Shapiro, W. R., Phan, S. C., Gervais, R., Carrie, C., Chabot, P., Patchell, R. A., Glantz, M. J., Recht, L., Langer, C., Sur, R. K., Roa, W. H., Mahe, M. A., Fortin, A., Nieder, C., Meyers, C. A., Smith, J. A., Miller, R. A., Renschler, M. F. 2009; 73 (4): 1069-1076

  Abstract

  To determine the efficacy of motexafin gadolinium (MGd) in combination with whole brain radiotherapy (WBRT) for the treatment of brain metastases from non-small-cell lung cancer.In an international, randomized, Phase III study, patients with brain metastases from non-small-cell lung cancer were randomized to WBRT with or without MGd. The primary endpoint was the interval to neurologic progression, determined by a centralized Events Review Committee who was unaware of the treatment the patients had received.Of 554 patients, 275 were randomized to WBRT and 279 to WBRT+MGd. Treatment with MGd was well tolerated, and 92% of the intended doses were administered. The most common MGd-related Grade 3+ adverse events included liver function abnormalities (5.5%), asthenia (4.0%), and hypertension (4%). MGd improved the interval to neurologic progression compared with WBRT alone (15 vs. 10 months; p = 0.12, hazard ratio [HR] = 0.78) and the interval to neurocognitive progression (p = 0.057, HR = 0.78). The WBRT patients required more salvage brain surgery or radiosurgery than did the WBRT+MGd patients (54 vs. 25 salvage procedures, p < 0.001). A statistically significant interaction between the geographic region and MGd treatment effect (which was in the prespecified analysis plan) and between treatment delay and MGd treatment effect was found. In North American patients, where treatment was more prompt, a statistically significant prolongation of the interval to neurologic progression, from 8.8 months for WBRT to 24.2 months for WBRT+MGd (p = 0.004, HR = 0.53), and the interval to neurocognitive progression (p = 0.06, HR = 0.73) were observed.In the intent-to-treat analysis, MGd exhibited a favorable trend in neurologic outcomes. MGd significantly prolonged the interval to neurologic progression in non-small-cell lung cancer patients with brain metastases receiving prompt WBRT. The toxicity was acceptable.

  View details for DOI 10.1016/j.ijrobp.2008.05.068

  View details for Web of Science ID 000264257400017

  View details for PubMedID 18977094

• EGFRvIII expression and PTEN loss synergistically induce chromosomal instability and glial tumors NEURO-ONCOLOGY Li, L., Dutra, A., Pak, E., Labrie, J. E., Gerstein, R. M., Pandolfi, P. P., Recht, L. D., Ross, A. H. 2009; 11 (1): 9-21

  Abstract

  Glioblastomas often show activation of epidermal growth factor receptor (EGFR) and loss of PTEN (phosphatase and tensin homolog deleted on chromosome 10) tumor suppressor, but it is not known if these two genetic lesions act together to transform cells. To answer this question, we infected PTEN-/- neural precursor cells with a retrovirus encoding EGFRvIII, which is a constitutively activated receptor. EGFRvIII PTEN-/- cells formed highly mitotic tumors with nuclear pleomorphism, necrotic areas, and glioblastoma markers. The transformed cells showed increased cell proliferation, centrosome amplification, colony formation in soft agar, self-renewal, expression of the stem cell marker CD133, and resistance to oxidative stress and ionizing radiation. The RAS/mitogen-activated protein kinase (ERK) and phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) pathways were activated, and checkpoint kinase 1 (Chk1), the DNA damage regulator, was phosphorylated at S280 by Akt, suppressing Chk1 phosphorylation at S345 in response to ionizing irradiation. The PTEN-/- cells showed low levels of DNA damage in the absence of irradiation, which was increased by EGFRvIII expression. Finally, secondary changes occurred during tumor growth in mice. Cells from these tumors showed decreased tumor latencies and additional chromosomal aberrations. Most of these tumor lines showed translocations of mouse chromosome 15. Intracranial injections of one of these lines led to invasive, glial fibrillary acidic protein-positive, nestin-positive tumors. These results provide a molecular basis for the occurrence of these two genetic lesions in brain tumors and point to a role in induction of genomic instability.

  View details for DOI 10.1215/15228517-2008-081

  View details for Web of Science ID 000263296800003

  View details for PubMedID 18812521

  View details for PubMedCentralID PMC2718963

• Embryonic stem cell rescue of tremor and ataxia in myelin-deficient shiverer mice JOURNAL OF THE NEUROLOGICAL SCIENCES Low, H. P., Greco, B., Tanahashi, Y., Gallant, J., Jones, S. N., Billings-Gagliardi, S., Recht, L. D., Schwartz, W. J. 2009; 276 (1-2): 133-137

  Abstract

  Transplantation of neural precursor cells has been proposed as a possible approach for replacing missing or damaged central nervous system myelin. Neonatal and adult myelin-deficient shiverer (shi) mice, bearing a mutation of the myelin basic protein (MBP) gene, have been used extensively as hosts for testing cell engraftment, migration, and myelination, but relatively little progress has been made in reversing shi motor deficits. Here we describe a prenatal cell replacement strategy, showing that embryonic stem cells injected into shi blastocyst embryos can generate chimeric mice with strong and widespread immunoreactive MBP expression throughout the brain and a behavioral (motor) phenotype that appears essentially rescued.

  View details for DOI 10.1016/j.jns.2008.09.037

  View details for Web of Science ID 000263125200030

  View details for PubMedID 18996543

• A distinct phenotypic change in gliomas at the time of magnetic resonance imaging detection JOURNAL OF NEUROSURGERY Jang, T., Sathy, B., Hsu, Y., Merchant, M., Recht, B., Chang, C., Recht, L. 2008; 108 (4): 782-790

  Abstract

  Although gliomas remain refractory to treatment, it is not clear whether this characteristic is fixed at the time of its origin or develops later. The authors have been using a model of neurocarcinogenesis to determine whether a time exists during a glioma's evolution during which it is detectable but still curable, thus providing a justification for exploring the clinical merits of an early detection and treatment strategy. The authors recently reported the presence of 2 distinct cellular subsets, 1 expressing nestin and the other both glial fibrillary acidic protein (GFAP) and osteopontin (OPN), within all examined gliomas that developed after in utero exposure to ethylnitrosourea.In this study, the authors used magnetic resonance (MR) imaging to assess when these 2 subpopulations appeared during glioma evolution.Using T2-weighted and diffusion-weighted MR imaging, the authors observed that gliomas grew exponentially once detected at rates that were location-dependent. Despite large differences in growth rates, however, they determined by correlating histochemistry with imaging in a second series of animals, that all lesions initially detected on T2-weighted images contained both subsets of cells. In contrast, lesions containing only nestin-positive cells, which appeared on average 40 days before detection on MR images, were not detected.The sequential appearance of first the nestin-positive cells followed several weeks later by those expressing GFAP/OPN suggests that all gliomas arise through common early steps in this model. Furthermore, the authors hypothesize that the expression of OPN, a molecule associated with cancer aggressiveness, at the time of T2-weighted detection signals a time during glioma development when the lesion becomes refractory to treatment.

  View details for DOI 10.3171/JNS/2008/108/4/0782

  View details for Web of Science ID 000254326200023

  View details for PubMedID 18377259

• Optimizing therapy for patients with brain metastases SEMINARS IN ONCOLOGY Kuo, T., Recht, L. 2006; 33 (3): 299-306

  Abstract

  Brain metastases from systemic cancers are the most common malignant brain tumors encountered. Although prognosis remains poor, it is possible to stratify patients according to risk. Furthermore, an aggressive therapeutic approach for good-risk patients that includes a combination of either surgery or stereotactic radiosurgery (SRS) and whole brain radiation therapy (WBRT) can improve survival and decrease the risk of central nervous system progression.

  View details for DOI 10.1053/j.seminoncol.2006.03.005

  View details for Web of Science ID 000238731100003

  View details for PubMedID 16769418

• Osteopontin expression in intratumoral astrocytes marks tumor progression in gliomas induced by prenatal exposure to N-ethyl-N-nitrosourea AMERICAN JOURNAL OF PATHOLOGY Jang, T. C., Savarese, T., Low, H. P., Kim, S., Vogel, H., Lapointe, D., Duong, T., Litofsky, N. S., Weimann, J. M., Ross, A. H., Recht, L. 2006; 168 (5): 1676-1685

  Abstract

  To better study early events in glioma genesis, markers that reliably denote landmarks in glioma development are needed. In the present study, we used microarray analysis to compare the gene expression patterns of magnetic resonance imaging (MRI)-localized N-ethyl-N-nitrosourea (ENU)-induced tumors in rat brains with those of uninvolved contralateral side and normal brains. Our analysis identified osteopontin (OPN) as the most up-regulated gene in glioma. Using immunohistochemistry we then confirmed OPN expression in every tumor examined (n = 17), including those with diameters as small as 300 mum. By contrast, no OPN immunostaining was seen in normal brain or in brains removed from ENU-exposed rats before the development of glioma. Further studies confirmed that OPN was co-localized exclusively in intratumoral glial fibrillary acidic protein-expressing cells and was notably absent from nestin-expressing ones. In conjunction with this, we confirmed that both normal neurosphere cells and ENU-im-mortalized subventricular zone/striatal cells produced negligible amounts of OPN compared to the established rat glioma cell line C6. Furthermore, inducing OPN expression in an immortalized cell line increased cell proliferation. Based on these findings, we conclude that OPN overexpression in ENU-induced gliomas occurs within a specific subset of intratumoral glial fibrillary acidic protein-positive cells and becomes evident at the stage of tumor progression.

  View details for DOI 10.2353/ajpath.2006.050400

  View details for PubMedID 16651633

• Tumor necrosis factor-alpha-induced protein 3 as a putative regulator of nuclear factor-kappa B-mediated resistance to O-6-alkylating agents in human glioblastomas JOURNAL OF CLINICAL ONCOLOGY Bredel, M., Bredel, C., Juric, D., Duran, G. E., Yu, R. X., Harsh, G. R., Vogel, H., Recht, L. D., Scheck, A. C., Sikic, B. I. 2006; 24 (2): 274-287

  Abstract

  Pre-existing and acquired drug resistance are major obstacles to the successful treatment of glioblastomas.We used an integrated resistance model and genomics tools to globally explore molecular factors and cellular pathways mediating resistance to O6-alkylating agents in glioblastoma cells.We identified a transcriptomic signature that predicts a common in vitro and in vivo resistance phenotype to these agents, a proportion of which is imprinted recurrently by gene dosage changes in the resistant glioblastoma genome. This signature was highly enriched for genes with functions in cell death, compromise, and survival. Modularity was a predominant organizational principle of the signature, with functions being carried out by groups of interacting molecules in overlapping networks. A highly significant network was built around nuclear factor-kappaB (NF-kappaB), which included the persistent alterations of various NF-kappaB pathway elements. Tumor necrosis factor-alpha-induced protein 3 (TNFAIP3) was identified as a new regulatory component of a putative cytoplasmic signaling cascade that mediates NF-kappaB activation in response to DNA damage caused by O6-alkylating agents. Expression of the corresponding zinc finger protein A20 closely mirrored the expression of the TNFAIP3 transcript, and was inversely related to NF-kappaB activation status in the resistant cells. A prediction model based on the resistance signature enabled the subclassification of an independent, validation cohort of 31 glioblastomas into two outcome groups (P = .037) and revealed TNFAIP3 as part of an optimized four-gene predictor associated significantly with patient survival (P = .022).Our results offer strong evidence for TNFAIP3 as a key regulator of the cytoplasmic signaling to activate NF-kappaB en route to O6-alkylating agent resistance in glioblastoma cells. This pathway may be an attractive target for therapeutic modulation of glioblastomas.

  View details for DOI 10.1200/JCO.2005.02.9405

  View details for PubMedID 16365179

• Functional network analysis reveals extended gliomagenesis pathway maps and three novel MYC-interacting genes in human gliomas CANCER RESEARCH Bredel, M., Bredel, C., Juric, D., Harsh, G. R., Vogel, H., Recht, L. D., Sikic, B. I. 2005; 65 (19): 8679-8689

  Abstract

  Gene expression profiling has proven useful in subclassification and outcome prognostication for human glial brain tumors. The analysis of biological significance of the hundreds or thousands of alterations in gene expression found in genomic profiling remains a major challenge. Moreover, it is increasingly evident that genes do not act as individual units but collaborate in overlapping networks, the deregulation of which is a hallmark of cancer. Thus, we have here applied refined network knowledge to the analysis of key functions and pathways associated with gliomagenesis in a set of 50 human gliomas of various histogenesis, using cDNA microarrays, inferential and descriptive statistics, and dynamic mapping of gene expression data into a functional annotation database. Highest-significance networks were assembled around the myc oncogene in gliomagenesis and around the integrin signaling pathway in the glioblastoma subtype, which is paradigmatic for its strong migratory and invasive behavior. Three novel MYC-interacting genes (UBE2C, EMP1, and FBXW7) with cancer-related functions were identified as network constituents differentially expressed in gliomas, as was CD151 as a new component of a network that mediates glioblastoma cell invasion. Complementary, unsupervised relevance network analysis showed a conserved self-organization of modules of interconnected genes with functions in cell cycle regulation in human gliomas. This approach has extended existing knowledge about the organizational pattern of gene expression in human gliomas and identified potential novel targets for future therapeutic development.

  View details for DOI 10.1158/0008-5472

  View details for PubMedID 16204036

• High-resolution genome-wide mapping of genetic alterations in human glial brain tumors CANCER RESEARCH Bredel, M., Bredel, C., Juric, D., Harsh, G. R., Vogel, H., Recht, L. D., Sikic, B. I. 2005; 65 (10): 4088-4096

  Abstract

  High-resolution genome-wide mapping of exact boundaries of chromosomal alterations should facilitate the localization and identification of genes involved in gliomagenesis and may characterize genetic subgroups of glial brain tumors. We have done such mapping using cDNA microarray-based comparative genomic hybridization technology to profile copy number alterations across 42,000 mapped human cDNA clones, in a series of 54 gliomas of varying histogenesis and tumor grade. This gene-by-gene approach permitted the precise sizing of critical amplicons and deletions and the detection of multiple new genetic aberrations. It has also revealed recurrent patterns of occurrence of distinct chromosomal aberrations as well as their interrelationships and showed that gliomas can be clustered into distinct genetic subgroups. A subset of detected alterations was shown predominantly associated with either astrocytic or oligodendrocytic tumor phenotype. Finally, five novel minimally deleted regions were identified in a subset of tumors, containing putative candidate tumor suppressor genes (TOPORS, FANCG, RAD51, TP53BP1, and BIK) that could have a role in gliomagenesis.

  View details for PubMedID 15899798

• Amplification of whole tumor genomes and geneby-gene mapping of genomic aberrations from limited sources of fresh-frozen and paraffin-embedded DNA JOURNAL OF MOLECULAR DIAGNOSTICS Bredel, M., Bredel, C., Juric, D., Kim, Y., Vogel, H., Harsh, G. R., Recht, L. D., Pollack, J. R., Sikic, B. I. 2005; 7 (2): 171-182

  Abstract

  Sufficient quantity of genomic DNA can be a bottleneck in genome-wide analysis of clinical tissue samples. DNA polymerase Phi29 can be used for the random-primed amplification of whole genomes, although the amplification may introduce bias in gene dosage. We have performed a detailed investigation of this technique in archival fresh-frozen and formalin-fixed/paraffin-embedded tumor DNA by using cDNA microarray-based comparative genomic hybridization. Phi29 amplified DNA from matched pairs of fresh-frozen and formalin-fixed/paraffin-embedded tumor samples with similar efficiency. The distortion in gene dosage representation in the amplified DNA was nonrandom and reproducibly involved distinct genomic loci. Regional amplification efficiency was significantly linked to regional GC content of the template genome. The biased gene representation in amplified tumor DNA could be effectively normalized by using amplified reference DNA. Our data suggest that genome-wide gene dosage alterations in clinical tumor samples can be reliably assessed from a few hundred tumor cells. Therefore, this amplification method should lend itself to high-throughput genetic analyses of limited sources of tumor, such as fine-needle biopsies, laser-microdissected tissue, and small paraffin-embedded specimens.

  View details for PubMedID 15858140

• Isolation of immortalized, INK4a/ARF-deficient cells from the subventricular zone after in utero N-ethyl-N-nitrosourea exposure JOURNAL OF NEUROSURGERY Savarese, T. M., Jang, T., Low, H. P., Salmonsen, R., Litofsky, N. S., Matijasevic, Z., Ross, A. H., Recht, L. D. 2005; 102 (1): 98-108

  Abstract

  Brain tumors, including gliomas, develop several months after rats are exposed in utero to N-ethyl-N-nitroso-urea (ENU). Although pathological changes cannot be detected until these animals are several weeks old, the process that eventually leads to glioma formation must begin soon after exposure given the rapid clearance of the carcinogen and the observation that transformation of brain cells isolated soon after exposure occasionally occurs. This model can therefore potentially provide useful insights about the early events that precede overt glioma formation. The authors hypothesized that future glioma cells arise from stem/progenitor cells residing in or near the subventricular zone (SVZ) of the brain.Cells obtained from the SVZ or corpus striatum in ENU-exposed and control rats were cultured in an epidermal growth factor (EGF)-containing, chemically defined medium. Usually, rat SVZ cells cultured in this manner (neurospheres) are nestin-positive, undifferentiated, and EGF-dependent and undergo cell senescence. Consistent with these prior observations, control SVZ cells undergo senescence by the 12th to 15th doubling (20 of 20 cultures). In contrast, three of 15 cultures of cells derived from the SVZs of individual ENU-treated rats continue to proliferate for more than 60 cell passages. Each of these nestin-expressing immortalized cell lines harbored a common homozygous deletion spanning the INK4a/ARF locus and was unable to differentiate into neural lineages after exposure to specific in vitro stimuli. Nevertheless, unlike the rat C6 glioma cell line, these immortalized cell lines demonstrate EGF dependence and low clonogenicity in soft agar and did not form tumors after intracranial transplantation.Data in this study indicated that immortalized cells may represent glioma precursors that reside in the area of the SVZ after ENU exposure that may serve as a reservoir for further genetic and epigenetic hits that could eventually result in a full glioma phenotype.

  View details for Web of Science ID 000226292300015

  View details for PubMedID 15658102

• Prevention and treatment of central nervous system involvement by non-Hodgkin's lymphoma: A review of the literature SEMINARS IN NEUROLOGY Colocci, N., Glantz, M., Recht, L. 2004; 24 (4): 395-404

  Abstract

  Direct invasion of the central nervous system (CNS) occurs in 5% of all patients with non-Hodgkin's lymphoma, either at the time of presentation, as a solitary site of relapse, or during the course of progressive disease. Over the last several years, several studies, mostly retrospective, have analyzed risk factors associated with this complication as well as various methods to both treat and prevent it. A systematic review of the literature reveals that although a profile of a patient at particularly high risk for developing disease can be identified, treatments are for the most part ineffective at improving survival in patients with CNS lymphoma, and there is no high-quality evidence that prophylaxis prevents its occurrence. A randomized controlled trial to assess the value of prophylaxis in this disease is warranted, and suggestions for how such a trial might be designed are included in this review.

  View details for Web of Science ID 000226151200007

  View details for PubMedID 15637651

• Treatment of neoplastic meningitis: what is the standard of care? Expert review of neurotherapeutics Recht, L., Phuphanich, S. 2004; 4 (4): S11-7

  Abstract

  This discussion will focus on defining the standard of care for neoplastic meningitis, including: What is the role of radiation therapy? What are first-line pharmacotherapeutic agents? Is combination therapy useful? What is the role of corticosteroids?

  View details for PubMedID 15853550

• Aberrant nestin expression during ethylnitrosourea-(ENU)-induced neurocarcinogenesis NEUROBIOLOGY OF DISEASE Jang, T. C., Litofsky, N. S., Smith, T. W., Ross, A. H., Recht, L. D. 2004; 15 (3): 544-552

  Abstract

  Nestin is a unique intermediate filament protein. While it is robustly expressed in developing brain, postnatal expression is limited to the brain's subventricular zone (SVZ) and endothelial cells. Reexpression occurs, however, under several pathological conditions, including injury and neoplasia. We hypothesized that nestin would be a sensitive marker of early neoplasia after transplacental exposure of rats to ethylnitrosourea (ENU). Rats of various ages were administered bromodeoxyuridine (BudR) before sacrifice, and brain sections were examined for proliferative cells and several immunohistochemical markers, including nestin. Additional rats were examined after a stab wound injury to assess the expression of two of these markers, GFAP and nestin, in reactive astrocytes. All ENU-induced brain tumors (n = 9) were classified as gliomas (astrocytomas or oligoastrocytomas) based on their histology and immunophenotype. Nestin expression was noted in all tumors examined and was present in tumor cells as well as endothelial cells. During tumor development, we consistently noted nestin-expressing cells bearing multiple processes distributed throughout brain parenchyma. Both single cells and multiple cell clusters were observed as early as postnatal day 30 in all ENU-exposed brains examined (n = 11). Such distinctive nestin-expressing cells were not seen in nestin-stained control brains or ENU-exposed brains stained for GFAP or vimentin, nor was such a cell seen in a stab wound model used to assess reactive astrocytosis. While the number of these clusters was highly variable among rats, their size increased between 30 and 90 days. The data suggest that these nestin-expressing cells represent an early stage of the neoplastic process. It remains to be determined whether these cells become apparent at 30 days of age due to "dedifferentiation" of a local resident astrocyte or astrocyte precursor cell or migration of a relatively undifferentiated precursor/stem cell from the SVZ.

  View details for DOI 10.1016/j.nbd.2003.11.016

  View details for Web of Science ID 000220796700013

  View details for PubMedID 15056462

• Differentiation prevents assessment of neural stem cell pluripotency after blastocyst injection STEM CELLS Greco, B., Low, H. P., Johnson, E. C., Salmonsen, R. A., Gallant, J., Jones, S. N., Ross, A. H., Recht, L. D. 2004; 22 (4): 600-608

  Abstract

  Earlier studies reported that neural stem (NS) cells injected into blastocysts appeared to be pluripotent, differentiating into cells of all three germ layers. In this study, we followed in vitro green fluorescent protein (GFP)-labeled NS and embryonic stem (ES) cells injected into blastocysts. Forty-eight hours after injection, significantly fewer blastocysts contained GFP-NS cells than GFP-ES cells. By 96 hours, very few GFP-NS cells remained in blastocysts compared with ES cells. Moreover, 48 hours after injection, GFP-NS cells in blastocysts extended long cellular processes, ceased expressing the NS cell marker nestin, and instead expressed the astrocytic marker glial fibrillary acidic protein. GFP-ES cells in blastocysts remained morphologically undifferentiated, continuing to express the pluripotent marker stage-specific embryonic antigen-1. Selecting cells from the NS cell population that preferentially formed neurospheres for injection into blastocysts resulted in identical results. Consistent with this in vitro behavior, none of almost 80 mice resulting from NS cell-injected blastocysts replaced into recipient mothers were chimeric. These results strongly support the idea that NS cells cannot participate in chimera formation because of their rapid differentiation into glia-like cells. Thus, these results raise doubts concerning the pluripotency properties of NS cells.

  View details for Web of Science ID 000223066800016

  View details for PubMedID 15277705