Kiel, Mark J. | Velusamy, Thirunavukkarasu | Betz, Bryan L. | Zhao, Lili | Weigelin, Helmut G. | Chiang, Mark Y. | Huebner-Chan, David R. | Bailey, Nathanael G. | Yang, David T. | Bhagat, Govind | Miranda, Roberto N. | Bahler, David W. | Medeiros, L. Jeffrey | Lim, Megan S. | Elenitoba-Johnson, Kojo S.J.
NOTCH2 mutations in splenic marginal zone lymphoma are associated with poor prognosis.
Splenic marginal zone lymphoma (SMZL), the most common primary lymphoma of spleen, is poorly understood at the genetic level. In this study, using whole-genome DNA sequencing (WGS) and confirmation by Sanger sequencing, we observed mutations identified in several genes not previously known to be recurrently altered in SMZL. In particular, we identified recurrent somatic gain-of-function mutations in NOTCH2, a gene encoding a protein required for marginal zone B cell development, in 25 of 99 (∼25%) cases of SMZL and in 1 of 19 (∼5%) cases of nonsplenic MZLs. These mutations clustered near the C-terminal proline/glutamate/serine/threonine (PEST)-rich domain, resulting in protein truncation or, rarely, were nonsynonymous substitutions affecting the extracellular heterodimerization domain (HD). NOTCH2 mutations were not present in other B cell lymphomas and leukemias, such as chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL; n = 15), mantle cell lymphoma (MCL; n = 15), low-grade follicular lymphoma (FL; n = 44), hairy cell leukemia (HCL; n = 15), and reactive lymphoid hyperplasia (n = 14). NOTCH2 mutations were associated with adverse clinical outcomes (relapse, histological transformation, and/or death) among SMZL patients (P = 0.002). These results suggest that NOTCH2 mutations play a role in the pathogenesis and progression of SMZL and are associated with a poor prognosis.
doi:10.1084/jem.20120910
PMCID: PMC3428949
PMID: 22891276
Yang, David P. | Kim, Jihyun | Syed, Neeraja | Tung, Young-john | Bhaskaran, Ambily | Mindos, Thomas | Mirsky, Rhona | Jessen, Kristjan R. | Maurel, Patrice | Parkinson, David B. | Kim, Haesun A.
Physical damage to the peripheral nerves triggers Schwann cell injury response in the distal nerves in an event termed Wallerian degeneration: the Schwann cells degrade their myelin sheaths and de-differentiate, reverting to a phenotype that supports axon regeneration and nerve repair. The molecular mechanisms regulating Schwann cell plasticity in the PNS remain to be elucidated. Using both in vivo and in vitro models for peripheral nerve injury, here we show that inhibition of p38 MAPK activity in mice blocks Schwann cell demyelination and de-differentiation following nerve injury, suggesting that the kinase mediates the injury signal that triggers distal Schwann cell injury response. In myelinating co-cultures, p38 MAPK also mediates myelin breakdown induced by Schwann cell growth factors, such as neuregulin and FGF-2. Furthermore, ectopic activation of p38 MAPK is sufficient to induce myelin breakdown and drives differentiated Schwann cells to acquire phenotypic features of immature Schwann cells. We also show that p38 MAPK concomitantly functions as a negative regulator of Schwann cell differentiation: enforced p38 MAPK activation blocks cAMP-induced expression of Krox 20 and myelin proteins, but induces expression of c-Jun. As expected of its role as a negative signal for myelination, inhibition of p38 MAPK in co-cultures promotes myelin formation by increasing the number as well as the length of individual myelin segments. Altogether, our data identify p38 MAPK as an important regulator of Schwann cell plasticity and differentiation.
doi:10.1523/JNEUROSCI.5812-11.2012
PMCID: PMC3369433
PMID: 22623660
Wallerian degeneration; dedifferentiation; MKK6; c-Jun; cAMP
Yang, David P. | Kim, Jihyun | Syed, Neeraja | Tung, Young-john | Bhaskaran, Ambily | Mindos, Thomas | Mirsky, Rhona | Jessen, Kristjan R. | Maurel, Patrice | Parkinson, David B. | Kim, Haesun A.
Physical damage to the peripheral nerves triggers Schwann cell injury response in the distal nerves in an event termed Wallerian degeneration: the Schwann cells degrade their myelin sheaths and de-differentiate, reverting to a phenotype that supports axon regeneration and nerve repair. The molecular mechanisms regulating Schwann cell plasticity in the PNS remain to be elucidated. Using both in vivo and in vitro models for peripheral nerve injury, here we show that inhibition of p38 MAPK activity in mice blocks Schwann cell demyelination and de-differentiation following nerve injury, suggesting that the kinase mediates the injury signal that triggers distal Schwann cell injury response. In myelinating co-cultures, p38 MAPK also mediates myelin breakdown induced by Schwann cell growth factors, such as neuregulin and FGF-2. Furthermore, ectopic activation of p38 MAPK is sufficient to induce myelin breakdown and drives differentiated Schwann cells to acquire phenotypic features of immature Schwann cells. We also show that p38 MAPK concomitantly functions as a negative regulator of Schwann cell differentiation: enforced p38 MAPK activation blocks cAMP-induced expression of Krox 20 and myelin proteins, but induces expression of c-Jun. As expected of its role as a negative signal for myelination, inhibition of p38 MAPK in co-cultures promotes myelin formation by increasing the number as well as the length of individual myelin segments. Altogether, our data identify p38 MAPK as an important regulator of Schwann cell plasticity and differentiation.
doi:10.1523/JNEUROSCI.5812-11.2012
PMCID: PMC3369433
PMID: 22623660
Wallerian degeneration; dedifferentiation; MKK6; c-Jun; cAMP
doi:10.1155/2012/747416
PMCID: PMC3407656
PMID: 22851886
Water is an important route for human norovirus (HuNoV) transmission. Using magnetic beads conjugated with blood group-like antigens (HuNoV receptors), we developed a simple and rapid receptor-binding capture and magnetic sequestration (RBCMS) method and compared it to the existing negatively charged membrane absorption/elution (NCMAE) method for concentrating HuNoV from sewage effluent. RBCMS required 6-fold-less sample volume than the NCMAE method and also resulted in a significantly higher yield of HuNoV. The NCMAE and RBCMS concentrations of genogroup I (GI) HuNoV measured by quantitative reverse transcription-PCR (qRT-PCR) resulted in average threshold cycle (CT) values of 34.68 (8.68 copies, 252-fold concentration) versus 34.07 (13.05 copies, 477-fold concentration), respectively; the NCMAE and RBCMS concentrations of genogroup II (GII) HuNoV were measured as average CT values of 33.32 (24.7 copies, 239-fold concentration) versus 32.38 (46.9 copies, 333-fold concentration), respectively. The specificity of qRT-PCR was confirmed by traditional RT-PCR and an RNase I protection assay. The qRT-PCR signal from RBCMS-concentrated HuNoV treated with RNase I indicated that it was from encapsidated RNA and, probably, viable virus. In contrast, the qRT-PCR signal from NCMAE-concentrated HuNoV was not protected from RNase I and, likely, degradation. Both GI and GII HuNoV were detected from sewage effluent samples collected between April and July with average concentrations of 7.8 × 103 genomic copies per liter (gc/liter) and 4.3 × 104 gc/liter, respectively. No GI and <2% GII HuNoV were detected in sewage samples stored at room temperature for 4 weeks. We conclude that RBCMS requires less sample volume, has better recovery and sensitivity, and is faster than NCMAE for detection of HuNoV in sewage.
doi:10.1128/AEM.06875-11
PMCID: PMC3255735
PMID: 22101044
Activation of hedgehog (HH) pathway signaling is observed in many tumors. Due to a feedback loop, the HH receptor Patched (PTCH-1) is overexpressed in tumors with activated HH signaling. Therefore, we sought to radiolabel the PTCH-1 ligand sonic (SHH) for detection of cancer cells with canonical HH activity. Receptor binding of 131I-SHH was increased in cell lines with high HH pathway activation. Our findings also show that PTCH-1 receptor expression is decreased upon treatment with HH signaling inhibitors, and receptor binding of 131I-SHH is significantly decreased following treatment with cyclopamine. In vivo imaging and biodistribution studies revealed significant accumulation of 131I-SHH within tumor tissue as compared to normal organs. Tumor-to-muscle ratios were approximately 8 : 1 at 5 hours, while tumor to blood and tumor to bone were 2 : 1 and 5 : 1, respectively. Significant uptake was also observed in liver and gastrointestinal tissue. These studies show that 131I-SHH is capable of in vivo detection of breast tumors with high HH signaling. We further demonstrate that the hedgehog receptor PTCH-1 is downregulated upon treatment with hedgehog inhibitors. Our data suggests that radiolabeled SHH derivatives may provide a method to determine response to SHH-targeted therapies.
doi:10.1155/2012/639562
PMCID: PMC3395403
PMID: 22811598
The nitro group of 2-nitroimidazole (NIM) enters the tumor cells and is bioreductively activated and fixed in the hypoxia cells. 1,4,8,11-tetraazacyclotetradecane (N4) has shown to be a stable chelator for 99mTc. The present study was aimed to develop 99mTc-cyclam-2-nitroimidazole (99mTc-N4-NIM) for tumor hypoxia imaging. N4-NIM precursor was synthesized by reacting N4-oxalate and 1,3-dibromopropane-NIM, yielded 14% (total synthesis). Cell uptake of 99mTc-N4-NIM and 99mTc-N4 was obtained in 13762 rat mammary tumor cells and mesothelioma cells in 6-well plates. Tissue distribution of 99mTc-N4-NIM was evaluated in breast-tumor-bearing rats at 0.5–4 hrs. Tumor oxygen tension was measured using an oxygen probe. Planar imaging was performed in the tumor-bearing rat and rabbit models. Radiochemical purity of 99mTc-N4-NIM was >96% by HPLC. Cell uptake of 99mTc-N4-NIM was higher than 99mTc-N4 in both cell lines. Biodistribution of 99mTc-N4-NIM showed increased tumor-to-blood and tumor-to-muscle count density ratios as a function of time. Oxygen tension in tumor tissue was 6–10 mmHg compared to 40–50 mmHg in normal muscle tissue. Planar imaging studies confirmed that the tumors could be visualized clearly with 99mTc-N4-NIM in animal models. Efficient synthesis of N4-NIM was achieved. 99mTc-N4-NIM is a novel hypoxic probe and may be useful in evaluating cancer therapy.
doi:10.1155/2012/828139
PMCID: PMC3376529
PMID: 22719210
FAT10, also known as diubiquitin, has been implicated in the regulation of diverse cellular processes, including mitosis, immune response, and apoptosis. We seek to identify FAT10-targeted proteins, an essential step in elucidating the physiological function of FAT10. To this end, human FAT10 or its non-conjugatable derivative, FAT10ΔGG, was overexpressed in HEK293 cells. We observed a number of high molecular weight FAT10 conjugates in cells expressing wild-type FAT10, but not in FAT10ΔGG. The FAT10 conjugates are inducible by TNF-α and accumulated significantly when cells were treated with proteasome inhibitor, MG132. Among them, tumor suppressor p53 was found to be FATylated. The p53 transcriptional activity was found to be substantially enhanced in FAT10-overexpressing cells. In addition, overexpressing FAT10 in HEK293 cells also reduced the population of p53 which cross reacted with monoclonal anti-p53 antibody, PAB240, known to recognize only the transcriptionally inactive p53. FAT10 in the nucleus was found co-localized with p53 and altered its subcellular compartmentalization. Furthermore, overexpressing FAT10 led to a reduction in the size of promyelocytic leukemia nuclear bodies (PML-NBs) and altered their distribution in the nucleus. Based on these observations, a potential mechanism which correlates FATylation of p53 to its translocation and transcriptional activation is discussed.
doi:10.1016/j.abb.2011.02.017
PMCID: PMC3133660
PMID: 21396347
We have developed ethylenedicysteine-glucosamine (ECG) as an alternative to 18F-fluoro-2-deoxy-D-glucose (18F-FDG) for cancer imaging.
ECG localizes in the nuclear components of cells via the hexosamine biosynthetic pathway. This study was to evaluate the feasibility of imaging mesothelioma with
99mTc-ECG and 68Ga-ECG. ECG was synthesized from thiazolidine-4-carboxylic acid and 1,3,4,6-tetra-O-acetyl-2-amino-D-glucopyranose, followed by reduction in sodium and liquid ammonia to yield ECG (52%). ECG was chelated with 99mTc/tin (II) and 68Ga/69Ga chloride for in vitro and in vivo studies in mesothelioma. The highest tumor uptake of 99mTc-ECG is 0.47 at 30 min post injection, and declined to 0.08 at 240 min post injection. Tumor uptake (%ID/g), tumor/lung, tumor/blood, and
tumor/muscle count density ratios for 99mTc-ECG (30–240 min) were 0.47 ± 0.06 to 0.08 ± 0.01; 0.71 ± 0.07 to 0.85 ± 0.04; 0.47 ± 0.03 to 0.51 ± 0.01, and 3.49 ± 0.24 to 5.06 ± 0.25; for 68Ga-ECG (15–60 min) were 0.70 ± 0.06 to 0.92 ± 0.08; 0.64 ± 0.05 to 1.15 ± 0.08; 0.42 ± 0.03 to 0.67 ± 0.07, and 3.84 ± 0.52 to 7.00 ± 1.42; for 18F-FDG (30–180 min) were 1.86 ± 0.22 to 1.38 ± 0.35; 3.18 ± 0.44 to 2.92 ± 0.34, 4.19 ± 0.44 to 19.41 ± 2.05 and 5.75 ± 2.55 to 3.33 ± 0.65, respectively. Tumor could be clearly visualized with 99mTc-ECG and 68Ga-ECG in mesothelioma-bearing rats. 99mTc-ECG and 68Ga-ECG showed increased uptake in mesothelioma, suggesting they may be useful in diagnosing mesothelioma and also monitoring therapeutic response.
doi:10.1155/2012/232863
PMCID: PMC3356907
PMID: 22645409
The purpose of this study was to develop an efficient way to synthesize 99mTc-O-[3-(1,4,8,11-tetraazabicyclohexadecane)-propyl]-tyrosine (99mTc-N4-Tyrosine), a novel amino acid-based radiotracer, and evaluate its potential in breast cancer gamma imaging. Precursor N4-Tyrosine was synthesized using a 5-step procedure, and its total synthesis yield was 38%. It was successfully labeled with 99mTc with high radiochemical purity (>95%). Cellular uptake of 99mTc-N4-Tyrosine was much higher than that of 99mTc-N4 and the clinical gold standard 18F-2-deoxy-2-fluoro-glucose (18F-FDG) in rat breast tumor cells in vitro. Tissue uptake and dosimetry estimation in normal rats revealed that 99mTc-N4-Tyrosine could be safely administered to humans. Evaluation in breast tumor-bearing rats showed that although 99mTc-N4-Tyrosine appeared to be inferior to 18F-FDG in distinguishing breast tumor tissue from chemical-induced inflammatory tissue, it had high tumor-to-muscle uptake ratios and could detect breast tumors clearly by planar scintigraphic imaging. 99mTc-N4-Tyrosine could thus be a useful radiotracer for use in breast tumor diagnostic imaging.
doi:10.1155/2012/671708
PMCID: PMC3303751
PMID: 22496612
Wuerzberger-Davis, Shelly M. | Chen, Yuhong | Yang, David T. | Kearns, Jeffrey D. | Bates, Paul W. | Lynch, Candace | Ladell, Nicholas C. | Yu, Mei | Podd, Andrew | Zeng, Hu | Huang, Tony T. | Wen, Renren | Hoffmann, Alexander | Wang, Demin | Miyamoto, Shigeki
SUMMARY
The N-terminal nuclear export sequence (NES) of inhibitor of nuclear factor kappa B (NF-κB) alpha (IκBα) promotes NF-κB export from the cell nucleus to the cytoplasm, but the physiological role of this export regulation remains unknown. Here we report the derivation and analysis of genetically targeted mice harboring a germline mutation in IκBα NES. Mature B cells in the mutant mice displayed nuclear accumulation of inactive IκBα complexes containing a NF-κB family member, cRel, causing their spatial separation from the cytoplasmic IκB kinase. This resulted in severe reductions in constitutive and canonical NF-κB activities, synthesis of p100 and RelB NF-κB members, noncanonical NF-κB activity, NF-κB target gene induction, and proliferation and survival responses in B cells. Consequently, mice displayed defective B cell maturation, antibody production, and formation of secondary lymphoid organs and tissues. Thus, IκBα nuclear export is essential to maintain constitutive, canonical, and noncanonical NF-κB activation potentials in mature B cells in vivo.
doi:10.1016/j.immuni.2011.01.014
PMCID: PMC3111750
PMID: 21333553
Background
Cancer biomarker studies utilizing the combination of tissue microarray and automated quantitative assessment of immunofluorescence (TMA-AQUA) have been successfully performed for various types of human carcinoma, but its performance characteristics have yet to be evaluated in human lymphoma.
Methods
A pilot TMA was constructed containing duplicate 1.5 mm cores from 15 cases of mantle cell lymphoma (MCL), 3 cases low-grade B-cell lymphoma, and 3 cases of benign lymphoid tissue. Protein expression of c-Myc, Cdc2, Cyclin D1, Ki-67, Mcm2, and p27 by immunofluorescence and chromagenic staining were evaluated by AQUA and visual scoring, respectively. Gene expression of cMYC, CDC2, and CCND1 was determined by quantitative nuclease protection assay (qNPA™).
Results
Protein expression between duplicate cores determined by AQUA showed excellent correlation for all markers (R = 0.79 to 0.94) and Cyclin D1 expression was significantly higher in MCL cases compared to non-MCL cases (p = 0.00019). Overall correlation of AQUA with scoring of chromagenic staining by two pathologists was good for all markers (R = 0.56 to 0.90), except Cdc2 (R = 0.25). Localization of expression to cytoplasmic and/or nuclear compartments was comparable to chromagenic staining patterns for all markers except Ki-67 and Mcm2, where a significant difference between nuclear and cytoplasmic expression could not be appreciated by AQUA, despite clear nuclear localization by chromagenic staining. Correlation of gene expression with protein expression was variable for CDC2, cMYC, and CCND1 (R = 0.32, 0.35, and 0.69).
Conclusions
TMA-AQUA has the potential to be successfully utilized as a high-throughput protein biomarker screening platform for MCL, however, appropriate target protein selection and antibody performance validation are factors that need to be considered.
doi:10.1097/PAI.0b013e3181ed47bc
PMCID: PMC3040491
PMID: 20881841
The Vav family of proteins are guanine nucleotide exchange factors which have been shown to be deregulated in several types of human cancer. There are three members of the Vav family that have been identified which are members of the Dbl domain superfamily and have specificity towards Rho/Rac GTPases. The Vav family plays an important role in normal hematologic system development and homeostasis, and Vav1 is largely restricted to the hematologic system. While Vav1 was originally identified as a proto-oncogene, several recent studies have shown that Vav family deletion leads to the development of T-cell malignancies in mice. In addition, Vav1 has been shown to play a role in the ATRA-mediated differentiation of promyelocytic leukemia cells. In this concise review, the gene structure and normal function of Vav1, as well as a possible role for Vav1 in the development of hematologic and other malignancies is reviewed.
PMCID: PMC3301436
PMID: 22432082
Vav1; guanine nucleotide exchange factor; lymphoma; leukemia
The control of dNTP concentrations is critical to the fidelity of DNA synthesis and repair. One level of regulation is through subcellular localization of ribonucleotide reductase. In S. cerevisiae, the small subunit, Rnr2-Rnr4, is nuclear while the large subunit, Rnr1, is cytoplasmic. In response to S-phase or DNA-damage, Rnr2-Rnr4 enters the cytoplasm to bind Rnr1, forming an active complex. We previously reported that Wtm1 anchors Rnr2-Rnr4 in the nucleus. Here, we identify DIF1 which regulates localization of Rnr2-Rnr4. Dif1 binds directly to the Rnr2-Rnr4 complex through a conserved Hug domain to drive nuclear import. Dif1 is both cell cycle- and DNA-damage regulated, the latter through the Mec1-Dun1 pathway. In response to DNA damage, Dun1 directly phosphorylates Dif1 to both inactivate and degrade Dif1, allowing Rnr2-Rnr4 to become cytoplasmic. We propose that Rnr2-Rnr4 nuclear localization is achieved by a dynamic combination of Wtm1-mediated nuclear retention to limit export, coupled with regulated nuclear import through Dif1.
doi:10.1016/j.molcel.2008.08.018
PMCID: PMC3245869
PMID: 18851834
Primary cardiac lymphoma is extremely uncommon. We report a case of a 54 year old Caucasian male with a history of non-small cell lung cancer treated by surgical resection who presented with chest pain and dyspnea on exertion. Computerized tomography (CT) imaging confirmed a 7.8×3.8 cm right atrial soft tissue mass infiltrating the lateral wall of the right atrium, and a 5 cm pericardiophrenic mass. Echocardiography confirmed a moderate pericardial effusion without tamponade physiology. Percutaneous biopsy of the pericardiophrenic mass revealed pathologic features diagnostic of NK/T-cell lymphoma. He received CHOP chemotherapy with some improvement in symptoms, but experienced radiographic progression after 2 cycles. He received palliative involved field radiotherapy but developed new sites of progressive disease within the abdomen and died shortly after completing radiotherapy. NK/T-cell lymphomas are aggressive tumors that may present with unusual extranodal disease sites. Prompt diagnosis with consideration for referral to a specialty center with experience in treatment of these rare tumors may offer the greatest potential for improving treatment outcomes.
doi:10.4081/hr.2011.e9
PMCID: PMC3238481
PMID: 22184541
Non-Hodgkin's lymphoma; oncological hematology; NK/T-cell lymphoma; cardiac.
doi:10.1155/2011/673697
PMCID: PMC3134862
PMID: 21765636
Objective. This study was aimed to study tissue distribution and tumor imaging potential of 68Ga-glycopeptide (GP) in tumor-bearing rodents by PET. Methods. GP was synthesized by conjugating glutamate peptide and chitosan. GP was labeled with 68Ga chloride for in vitro and in vivo studies. Computer outlined region of interest (counts per pixel) of the tumor and muscle (at the symmetric site) was used to determine tumor-to-muscle count density ratios. To ascertain the feasibility of 68Ga-GP in tumor imaging in large animals, PET/CT imaging of 68Ga-GP and 18F-FDG were conducted in New Zealand white rabbits bearing VX2 tumors. Standard uptake value of tumors were determined by PET up to 45 min. To determine blood clearance and half-life of 68Ga-GP, blood samples were collected from 10 seconds to 20 min. Results. Radiochemical purity of 68Ga-GP determined by instant thin-layer chromatography was >95%. Tumor uptake values (SUV) for 68Ga-GP and 18F-FDG in New Zealand white rabbits bearing VX2 tumors were 3.25 versus 7.04. PET images in tumor-bearing rats and rabbits confirmed that 68Ga-GP could assess tumor uptake. From blood clearance curve, the half-life of 68Ga-GP was 1.84 hr. Conclusion Our data indicate that it is feasible to use 68Ga-GP to assess tumor angiogenesis.
doi:10.1155/2011/267206
PMCID: PMC3085313
PMID: 21541212
Purpose. This study was to develop an efficient synthesis of 99mTc-O-[3-(1,4,8,11-tetraazabicyclohexadecane)-propyl]-α-methyl tyrosine (99mTc-N4-AMT) and evaluate its potential in cancer imaging. Methods. N4-AMT was synthesized by reacting N4-oxalate and 3-bromopropyl AMT (N-BOC, ethyl ester). In vitro cellular uptake kinetics of 99mTc-N4-AMT was assessed in rat mammary tumor cells. Tissue distribution of the radiotracer was determined in normal rats at 0.5–4 h, while planar imaging was performed in mammary tumor-bearing rats at 30–120 min. Results. The total synthesis yield of N4-AMT was 14%. Cellular uptake of 99mTc-N4-AMT was significantly higher than that of 99mTc-N4. Planar imaging revealed that 99mTc-N4-AMT rendered greater tumor/muscle ratios than 99mTc-N4. Conclusions. N4-AMT could be synthesized with a considerably high yield. Our in vitro and in vivo data suggest that 99mTc-N4-AMT, a novel amino acid-based radiotracer, efficiently enters breast cancer cells, effectively distinguishes mammary tumors from normal tissues, and thus holds the promise for breast cancer imaging.
doi:10.1155/2011/276907
PMCID: PMC3085329
PMID: 21541217
Members of the neuregulin-1 (Nrg1) growth factor family play important roles during Schwann cell development. Recently, it has been shown that the membrane-bound type III isoform is required for Schwann cell myelination. Interestingly, however, Nrg1 type II, a soluble isoform, inhibits the process. The mechanisms underlying these isoform-specific effects are unknown. It is possible that myelination requires juxtacrine Nrg1 signaling provided by the membrane-bound isoform, whereas paracrine stimulation by soluble Nrg1 inhibits the process. To investigate this, we asked whether Nrg1 type III provided in a paracrine manner would promote or inhibit myelination. We found that soluble Nrg1 type III enhanced myelination in Schwann cell-neuron co-cultures. It improved myelination of Nrg1 type III+/− neurons and induced myelination on normally non-myelinated sympathetic neurons. However, soluble Nrg1 type III failed to induce myelination on Nrg1 type III−/− neurons. To our surprise, low concentrations of Nrg1 type II also elicited a similar pro-myelinating effect. At high doses, however, both type II and III isoforms inhibited myelination and increased c-Jun expression in a manner dependent on Mek/Erk activation. These results indicate that paracrine Nrg1 signaling provides concentration-dependent bi-functional effects on Schwann cell myelination. Further, our studies suggest that there may be two distinct steps in Schwann cell myelination: an initial phase dependent on juxtacrine Nrg1 signaling and a later phase that can be promoted by paracrine stimulation.
doi:10.1523/JNEUROSCI.1681-09.2010
PMCID: PMC2870719
PMID: 20427670
Nrg1 type III; GGF; Ras/Raf/Erk; c-Jun; Krox 20; remyelination
The purpose of this study was to determine whether the Bcr-Abl tyrosine kinase can be assessed by gamma imaging using an 111Indium-labeled anti-phosphotyrosine antibody, and if the response to treatment with imatinib could be detected using this imaging technique. Anti-phosphotyrosine antibody (APT) was labeled with indium (111In) using ethylenedicysteine (EC) as a chelator. To determine if 111In-EC-APT could assess a non-receptor tyrosine kinase, xenografts of the human chronic myelogenous leukemia (CML) cell line K562 were used. Gamma scintigraphy of the tumor-bearing mice, before and after imatinib treatment, was obtained 1, 24, and 48 hours after they were given 111In-EC-APT (100 uCi/mouse, i.v.). 111In-EC-APT is preferentially taken up by Bcr-Abl-bearing tumor cells when compared to 111In-EC-BSA or 111In-EC-IgG1 controls, and comparable to the level of uptake of 111In-EC-Bcr-Abl. Imatinib treatment resulted in decreased expression of phosphorylated Bcr-Abl by Western blot analysis, which correlated with early (four days after starting imatinib) kinase down-regulation as assessed by imaging using 111In-EC-APT. The optimal time to imaging was 24 and 48 hours after injection of 111In-EC-APT. Although tumor regression was insignificant on day 4 after starting imatinib treatment, it was marked by day 14. 111In-EC-APT can assess intracellular phosphokinase activity, and down-regulation of phosphokinase activity predates tumor regression. This technique may therefore be useful in the clinic to detect the presence of phosphokinase activity, and for early prediction of response.
doi:10.1158/1535-7163.MCT-08-0656
PMCID: PMC2679515
PMID: 19258427
111In-EC-APT; CML; Bcr-Abl; anti-phosphotyrosine antibody; imatinib
Apoptosis is a form of programmed cell death necessary for the regulation of the size of organs in adult life. Disruption of apoptotic pathways has been suggested as an important regulatory mechanism in prostatic tumours. The aim of this study was to examine the expression of apoptosis-regulating genes bcl-2 and p53 using immunohistochemistry, and the Gleason score in core needle biopsy specimens of prostate adenocarcinoma. We studied bcl-2 and p53 expression in 30 cases of low-, 30 cases of intermediate- and 20 cases of high-grade prostate adenocarcinoma. Overexpression of bcl-2 and p53 were noted in 54 and 61 of 80 patients (67.5 and 76.25%), respectively. The statistical analysis of the present data suggested that there is significant relation between p53 and bcl-2 expression, and Gleason score in prostate cancer. Thus, immunohistochemistry is a useful investigative parameter in assessing apoptosis to analyse the prognosis of prostatic tumours.
doi:10.3892/etm_00000061
PMCID: PMC3445942
PMID: 22993553
prostate; adenocarcinoma; apoptosis; immunohistochemistry
Abou-Ghazal, Mohamed | Yang, David S. | Qiao, Wei | Reina-Ortiz, Chantal | Wei, Jun | Kong, Ling-Yuan | Fuller, Gregory N. | Hiraoka, Nobuyoshi | Priebe, Waldemar | Sawaya, Raymond | Heimberger, Amy B.
Purpose
The signal transducer and activator of transcription 3 (STAT3) is frequently overexpressed in most cancers, propagates tumorigenesis and is a key regulator of immune suppression in cancer patients. We sought to determine the incidence of phosphorylated STAT3 (p-STAT3) expression in malignant gliomas of different pathologic types, whether p-STAT3 expression is a negative prognostic factor, and whether p-STAT3 expression influences the inflammatory response within gliomas.
Methods
Using immunohistochemical analysis, we measured the incidence of p-STAT3 expression in 129 patients with gliomas of various pathologic types in a glioma tissue microarray. We categorized our results according to the total number of p-STAT3–expressing cells within the gliomas and correlated this number with the number of infiltrating T cells and T regulatory cells (Tregs). We then evaluated the association between p-STAT3 expression and median survival time using univariate and multivariate analyses.
Results
We did not detect p-STAT3 expression in normal brain tissues or low-grade astrocytomas. We observed significant differences in the incidence of p-STAT3 expression between the different grades of astrocytomas and different pathologic glioma types. p-STAT3 expression was associated with the population of tumor-infiltrating immune cells but not with that of Tregs. On univariate analysis, we found that p-STAT3 expression within anaplastic astrocytomas was a negative prognostic factor.
Conclusions
p-STAT3 expression is common within gliomas of both the astrocytic and oligodendroglial lineages and portends poor survival in patients with anaplastic astrocytomas. p-STAT3 expression differs significantly between gliomas of different pathologic types and grades and correlated with the degree of immune infiltration.
doi:10.1158/1078-0432.CCR-08-1329
PMCID: PMC2605668
PMID: 19088040
gliomas; p-STAT3; T lymphocytes; T regulatory cells; prognosis
Corpus-predominant infection with Helicobacter pylori (HP) results in the activation of programmed cell death pathways in surface, parietal, and chief cells. At present, mechanisms that regulate these pathways to result in HP-associated pathology are not fully understood. Because it is not known which survival and death pathways are present in gastric epithelial cells, we used an antibody panel to evaluate the expression of BCL-2 family prosurvival proteins or multi-Bcl-2 homology (BH)-domains (group 1) or BH3-only (group-2) proapoptotic proteins in the stomachs of uninfected or HP-infected C57BL/6 mice. This strategy identified BCL-2, BAK, and BAD as the major prosurvival and proapoptotic proteins, in surface cells and BAD as the only BCL-2 family protein expressed in parietal cells. Chief cells express altogether different effectors, including BCL-XL/BCL-2, for survival but have no constitutively expressed proapoptotic proteins. In model chief cells, however, the group 1 proapoptotic protein BCL-XS was expressed after exposure to proinflammatory cytokines concomitant with reduced viability, demonstrating that chief cells can transcriptionally regulate the induction of proapoptotic proteins to execute apoptosis. During HP infection, no additional BCL-2 family proteins were expressed in epithelial cells, whereas those present either remained unchanged or were reduced as cell deletion occurred over time. Additional studies demonstrated that the posttranslational regulation of BAD in surface and parietal cells was negatively affected by HP infection, a result that may be directly related to an increase in apoptosis during infection. Thus, gastric epithelial cells express cell-specific prosurvival and proapoptotic pathways. From the results presented here, mechanisms that regulate HP-related changes in the survival and death profile of gastric epithelial cells can be predicted and then tested, with the ultimate goal of elucidating important therapeutic targets to inhibit the progression of HP-related pathology in the stomach.
doi:10.1038/labinvest.2008.84
PMCID: PMC2766781
PMID: 18779780
apoptosis; BAD; BCL-X; gastric
Schechter, Naomi R. | Erwin, William D. | Yang, David J. | Kim, E. Edmund | Munden, Reginald F. | Forster, Kenneth | Taing, Lina C. | Cox, James D. | Macapinlac, Homer A. | Podoloff, Donald A.
Purpose
To assess the radiation dosimetry and biodistribution of 99mTc-labeled ethylene dicysteine deoxyglucose (99mTc-EC-DG) in patients with non-small-cell lung cancer (NSCLC).
Methods
Serial whole-body scans were acquired 0, 2, 4, 6 and 24 h after injection of 99mTc-EC-DG (925 MBq) in seven NSCLC patients. Radiation dosimetry, blood clearance and SPECT imaging of the primary tumor were assessed.
Results
The critical organ was the bladder wall, with average radiation absorbed dose over all seven patients of 2.47×10−2 mGy/MBq. The average effective dose equivalent and effective dose were 6.20×10−3 mSv/MBq (6.89 mSv/1,110 MBq) and 5.90×10−3 mSv/MBq (6.54 mSv/1,110 MBq), respectively. The primary tumor was visualized with SPECT in six patients. On final pathology, one patient had a granuloma, which did not enhance with 99mTc-EC-DG.
Conclusion
99mTc-EC-DG has acceptable dosimetric and biodistribution properties as a diagnostic tumor-imaging agent. Future studies are planned to evaluate its diagnostic potential.
doi:10.1007/s00259-009-1135-8
PMCID: PMC2758190
PMID: 19396440
EC-DG; Lung cancer; SPECT; Glucosamine; Deoxyglucose
Background
Early detection of cellular events is important to predict the outcome of the patients. This study was aimed to use 99mTc EC-annexin V to image tumor cells undergoing apoptosis.
Methods
In ten patients with breast cancer, scintigraphic images and dosimetric estimates were obtained after administering 99mTc EC-annexin V.
Results
Nine of the 10 cases showed detectable 99mTc EC-annexin V uptake in tumor. Higher values of T/N ratios are associated with patient after treatment.
Conclusions
Apoptosiscan be quantified using 99mTc EC-annexin V.
doi:10.1016/j.apradiso.2008.01.012
PMCID: PMC2562036
PMID: 18308577