151
|
Liu Y, Lou G, Wu W, Zheng M, Shi Y, Zhao D, Chen Z. Involvement of the NF-κB pathway in multidrug resistance induced by HBx in a hepatoma cell line. J Viral Hepat 2011; 18:e439-46. [PMID: 21914061 DOI: 10.1111/j.1365-2893.2011.01463.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
It is widely believed that hepatocellular cancer (HCC), especially HBV associated HCC, is highly resistant to chemotherapy. To investigate the molecular influence of HBx protein on multidrug resistance (MDR) in HCC and the potential role of the NF-κB pathway in this process. We established HBx-expressing cells by liposome-mediated transfection of the HBx into the HepG2 cell line. We found that HBx expression in HCC cells induces drug resistance against multiple drugs, a significantly lower apoptosis ratio in HepG2-HBx and HepG2.2.15 cells, compared with HepG2 and HepG2-3.1 cells (P < 0.05) after treating with 5-FU or adriamycin. And compared with the control group, the HBx-transfected cells showed a higher expression of MDR-associated and anti-apoptotic genes. Furthermore, we found that the NF-κB activity was remarkably high in the HBx-expressing cells as measured by p65 nuclear localization. In addition, the upregulated anti-apoptotic genes, Gadd45b and Survivin, in HBx-expressing HCC cells were downregulated by IMD-0354 treatment, which is the NF-κB pathway inhibitor. Taken together, these results suggest that HBx protein might be one of the causes for the occurrence of MDR in HCC, and the NF-κB pathway might be involved in this change.
Collapse
|
152
|
Yu CX, Regine W, Zheng M, Zhang J, Feigenberg SJ. Stereotactic radiosurgery for early-stage breast cancer: A new paradigm. J Clin Oncol 2011. [DOI: 10.1200/jco.2011.29.27_suppl.120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
120 Background: Stereotactic radiosurgery (SRS) has not been widely used for breast cancer partly due to: 1) the lack of a suitable immobilization device; and 2) the lack of a delivery system that can concentrate a high radiation dose noninvasively. We have developed a SRS system that effectively addresses these obstacles and demonstrated the dosimetric feasibility of simultaneously ablating the intact tumor and sterilizing the tumor bed. Methods: A breast immobilization device consists of a solid outer cup with embedded stereotactic frame and a porous inner cup; the two cups join at the chest wall side by a soft goggle-like lip for comfort. A negative pressure is applied to the space between the two cups to immobilize the breast tissues. 15 patients with surgical clips in their breast underwent a geometric reproducibility trial, in which the patients received two CT scans spaced 10-60 minutes while wearing the cup. A SRS delivery system uses 36 Co-60 sources that rotate around a focal point to produce 36 non-coplanar arcs. The breast cup is locked on the treatment couch with the patient in prone position. The couch moves dynamically during treatment, allowing the focal spots to “paint” the desired 3D dose distribution. Results: The reproducibility of the 42 available clips was 1.83 mm ± 1.08 mm (2 std) and patients reported good comfort. 8 treatment plans simultaneously delivering an ablative dose of 18Gy to an intact tumor plus a 3mm margin (CTV1) and 10Gy to the tumor bed (CTV2 = CTV1+1cm) have been developed and verified with measurements. The dose-volume histograms showed very uniform dose coverage with 98% of CTV1 receiving 18Gy and 100% of tumor bed receiving 10Gy. On average, only 21% of the normal breast receives greater than 5Gy, safe to deliver 3 fractions of such doses. Conclusions: A breast-specific SRS system has been developed. Dosimetric studies illustrated the feasibility of managing early-stage breast cancer with SRS. Clinical studies that will identify patients in whom current forms of surgery and postoperative radiation may be eliminated are planned, allowing completion of local therapies noninvasively within a few days rather than months.
Collapse
|
153
|
Kowalska AK, Zheng M, Derewenda U, Derewenda ZS. The crystal structure of the p27 component of human dynactin. Acta Crystallogr A 2011. [DOI: 10.1107/s0108767311094463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
|
154
|
Yu C, Feigenberg S, Yu Y, Zheng M, Wang C, Regine W. 775 poster STEREOTACTIC RADIOSURGERY FOR EARLY-STAGE BREAST CANCER: A NEW PARADIGM. Radiother Oncol 2011. [DOI: 10.1016/s0167-8140(11)70897-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
155
|
Jiang Q, Jiang G, Welty TE, Zheng M. Naloxone in the management of hepatic encephalopathy. J Clin Pharm Ther 2010; 35:333-41. [PMID: 20831534 DOI: 10.1111/j.1365-2710.2009.01120.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND/AIM This study aimed to assess the effectiveness and safety of naloxone in the management of hepatic encephalopathy (HE). METHODS Cochrane collaboration methodology was used in a meta-analysis of randomized controlled trials of naloxone therapy for HE. RESULTS Seventeen randomized trials were identified with 15 studies involving 1054 patients meeting criteria for inclusion. Naloxone use was associated with a significant improvement in HE [relative risk (RR) 1.46; 95% confidence interval (CI) 1.27-1.67; P = 0.0005]. This comparison showed statistical heterogeneity (P < 0.10, and χ2 = 44.93). Subgroup analysis indicated naloxone administered parenterally by intermittent or continuous infusions to be effective (RR 1.34; 95% CI 1.17-1.53; P < 0.0001). A significant in trials by infusion route (RR 1.42; 95% CI 1.19-1.69; P < 0.0001) interaction was observed. CONCLUSIONS Naloxone may improve HE. However, published data are limited.
Collapse
|
156
|
Shi D, Zheng Q, Chen D, Zhu L, Qin A, Fan J, Liao J, Xu Z, Lin Z, Norman P, Xu J, Nakamura T, Dai K, Zheng M, Jiang Q. Association of single-nucleotide polymorphisms in HLA class II/III region with knee osteoarthritis. Osteoarthritis Cartilage 2010; 18:1454-7. [PMID: 20691797 DOI: 10.1016/j.joca.2010.07.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2010] [Revised: 07/18/2010] [Accepted: 07/20/2010] [Indexed: 02/02/2023]
Abstract
OBJECTIVE A genome-wide association study and a replication using Japanese, Spanish and Greek Caucasian populations have recently indicated two single-nucleotide polymorphisms (SNPs) (rs7775228 and rs10947262) associated with knee Osteoarthritis (OA) susceptibility. We have further evaluated the association in knee OA subjects from Han Chinese and Australian Caucasian origin. METHODS Two independent case-control association studies were performed using Han Chinese and Australian Caucasian populations. The two SNPs were genotyped in patients who had primary symptomatic knee OA with radiographic confirmation and/or received total knee replacement surgery as well as in matched controls. They were subjected to statistic analyses. RESULTS A total of 991 OA patients and 1536 controls were genotyped. No significant difference was detected in genotype or allele frequencies of the two SNPs between knee OA and control groups in the two populations (all P>0.05). The association was also negative even after stratification by sex, body mass index (BMI) and Kellgren/Lawrence scores. The significant heterogeneity was detected between Chinese and Japanese (both P<0.05). In the Caucasian samples, no significant heterogeneity was detected (both P>0.05). The result of meta-analysis showed significant association between knee OA and rs10947262 in total subjects [summary OR=1.26, 95%confidence intervals (CI)=1.07-1.27, P=3 × 10(-8)] and in Caucasian samples (summary OR=1.28, 95%CI=1.04-1.57, P=0.02). CONCLUSION We demonstrated no association between the two SNPs in human leukocyte antigen (HLA) class II/III region and knee OA in Han Chinese population. A significant association was detected between SNP rs10947262 and knee OA in Caucasian subjects. Further replication studies are required to identify the impact of controversial association.
Collapse
|
157
|
Zhang JY, Wang XH, Wang LJ, Xu B, Zheng M. Effect of oxygenation of transperitoneal ventilation on the death time after asphyxiation in rabbits. Minerva Anestesiol 2010; 76:913-917. [PMID: 20838374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
BACKGROUND To observe the effects of transperitoneal ventilation on death time in asphyxiated rabbits. METHODS Twenty-four adult rabbits were randomly divided in three groups (N=8, each): control group (no transperitoneal ventilation), air group (transperitoneal ventilation with air) and oxygen group (transperitoneal ventilation with oxygen). All animals were anesthetized with pentobarbital (3%, 30 mg/kg) given via intramuscular injection. Autonomous breathing was maintained. Each rabbit's peritoneal cavity was punctured with two catheters, one of which was placed in the left lower abdomen and served as the inlet for gas; the other was placed in the right upper abdomen and served as the outlet for gas. Asphyxia was induced by clamping the rabbit's trachea; transperitoneal ventilation was then administered in the air group and the oxygen group. Rabbits' death times were recorded and their heart rate, blood pressure, PaO2, and PaCO2 were monitored and analyzed before asphyxia and every minute after asphyxia. RESULTS All animals died successively after asphyxia. The death time in the oxygen group was significantly longer than in the control group and the air group, with no significant difference between the control group and the air group. PaO2 of all three groups declined significantly and the levels of PaO2 within 1-4 minutes after asphyxia in the oxygen group were higher than in the other two groups. PaCO2 increased significantly in all groups with no significant difference among three groups within 1-3 minutes after asphyxia. The increase of PaCO2 at the fourth minute in the oxygen group was reduced in comparison to that observed in other groups. CONCLUSION These results suggest that transperitoneal ventilation can markedly prolong the death time of asphyxiated rabbits.
Collapse
|
158
|
Wang Y, Zheng M, Xiao J, Lu Y, Wang F, Lu J, Luo X, Zhu W, Jianga H, Chen K. Using support vector regression coupled with the genetic algorithm for predicting acute toxicity to the fathead minnow. SAR AND QSAR IN ENVIRONMENTAL RESEARCH 2010; 21:559-570. [PMID: 20818588 DOI: 10.1080/1062936x.2010.502300] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The potential toxicity of chemicals may present adverse effects to the environment and human health. The quantitative structure-activity relationship (QSAR) provides a useful method for hazard assessment. In this study, we constructed a QSAR model based on a highly heterogeneous data set of 571 compounds from the US Environmental Protection Agency, for predicting acute toxicity to the fathead minnow (Pimephales promelas). An approach coupling support vector regression (SVR) with the genetic algorithm (GA) was developed to build the model. The generated QSAR model showed excellent data fitting and prediction abilities: the squared correlation coefficients (r(2)) for the training set and the test set were 0.826 and 0.802, respectively. Only eight critical descriptors, most of which are closely related to the toxicity mechanism, were chosen by GA-SVR, making the derived model readily interpretable. In summary, the successful case reported here highlights that our GA-SVR approach can be used as a general machine learning method for toxicity prediction.
Collapse
|
159
|
LoRusso P, Krop IE, Burris HA, Vukelja SJ, Miller K, Zheng M, Chu Y, Lu M, Amler LC, Rugo HS. Quantitative assessment of diagnostic markers and correlations with efficacy in two phase II studies of trastuzumab-DM1 (T-DM1) for patients (pts) with metastatic breast cancer (MBC) who had progressed on prior HER2-directed therapy. J Clin Oncol 2010. [DOI: 10.1200/jco.2010.28.15_suppl.1016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
160
|
Bernaards C, Hegde P, Chen D, Holmgren E, Zheng M, Jubb AM, Koeppen H, Scherer SJ, Chen DS. Circulating vascular endothelial growth factor (VEGF) as a biomarker for bevacizumab-based therapy in metastatic colorectal, non-small cell lung, and renal cell cancers: Analysis of phase III studies. J Clin Oncol 2010. [DOI: 10.1200/jco.2010.28.15_suppl.10519] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
161
|
Zheng M, Li L, Tang YL, Liang XH. Biomarkers in tongue cancer: understanding the molecular basis and their clinical implications. Postgrad Med J 2010; 86:292-8. [DOI: 10.1136/pgmj.2009.086504] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
162
|
Zhang X, Liu HH, Weller P, Zheng M, Tao W, Wang J, Liao G, Monshouwer M, Peltz G. In silico and in vitro pharmacogenetics: aldehyde oxidase rapidly metabolizes a p38 kinase inhibitor. THE PHARMACOGENOMICS JOURNAL 2010; 11:15-24. [DOI: 10.1038/tpj.2010.8] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
163
|
Zhu G, Tang Y, Liang X, Zheng M, Yang J, Zhou H, Li L, Qin T. Role of hypoxia-inducible factor-1 alpha in the regulation of plasminogen activator activity in rat knee joint chondrocytes. Osteoarthritis Cartilage 2009; 17:1494-502. [PMID: 19490965 DOI: 10.1016/j.joca.2009.05.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2009] [Revised: 04/01/2009] [Accepted: 05/04/2009] [Indexed: 02/05/2023]
Abstract
OBJECTIVE To examine the effects of hypoxia-inducible factor-1alpha (HIF-1alpha) on the plasminogen activator's (PA) activity and on the expression of components of PA system in articular chondrocytes of rats. METHODS Chondrocytes from rat knee joint cartilage were cultured under normoxic, hypoxic, CoCl(2) simulated hypoxic, and interleukin-1beta (IL-1beta)-stimulated conditions. siRNA targeting HIF-1alpha was transfected into cells cultured under hypoxic, simulated hypoxic, and IL-1beta-stimulated conditions to silence HIF-1alpha. PA activity was determined by the hydrolysis of the chromogenic substrate H-D-Val-Leu-Lys-pNA (S-2251). The mRNA levels were measured by quantitative real-time reverse transcription polymerase chain reaction (RT-PCR). The intracellular/matrix-associate protein levels were detected by Western blot and the soluble protein levels were measured by enzyme linked immunosorbent assay (ELISA). Chromatin immunoprecipitation (CHIP) assay was performed to determine whether HIF-1alpha binds to the hypoxia response element (HRE) of target genes. RESULTS The enhancement of HIF-1alpha by CoCl(2) resulted in a decrease of PA activity, and the silence of HIF-1alpha by siRNA led to an increase of PA activity. The PA inhibitor-1 (PAI-1) mRNA and protein were increased by hypoxia or simulated hypoxia, which was reversed by the siRNA2-mediated silencing of HIF-1alpha. CHIP assay further confirmed that the induction of PAI-1 involved the binding of HIF-1alpha to the PAI-1 promoter, while the enhancement or silencing of HIF-1alpha did not affect the expression of urokinase type PA (uPA), tissue type PA (tPA) or uPA receptor (uPAR). Additionally, IL-1beta stimulated both HIF-1alpha and PAI-1 in articular chondrocytes, and the IL-1beta-mediated induction of PAI-1 was inhibited partly by HIF-1alpha silencing. CONCLUSION HIF-1alpha may inhibit the PA activity through stimulating the expression of PAI-1 in normal articular chondrocytes. The inhibition of HIF-1alpha in the PA activity of articular chondrocytes probably plays an important role in the maintenance of articular cartilage matrix.
Collapse
|
164
|
Ye SD, Zheng M, Zhao LL, Qian Y, Yao XM, Ren A, Li SM, Jing CY. Intensive insulin therapy decreases urinary MCP-1 and ICAM-1 excretions in incipient diabetic nephropathy. Eur J Clin Invest 2009; 39:980-5. [PMID: 19663918 DOI: 10.1111/j.1365-2362.2009.02203.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND Nowadays, intensive insulin treatment has been widely used in type 2 diabetics who have poor control of blood glucose, to reduce the risk of chronic complications of diabetes. Recently, some scholars have paid more attention to the pivotal role of inflammation involved in type 2 diabetes and its complications. Monocyte chemoattractant protein-1 (MCP-1) and intercellular adhesion molecule-1 (ICAM-1), which are two important inflammatory chemokines, have been documented to participate in the onset and development of type 2 diabetes and its complications, such as diabetic nephropathy (DN). DESIGN In the current study, we recruited 30 type 2 diabetics with microalbuminuria to be treated with multiple insulin injections daily for 2 weeks. Random spot urine samples (corrected for creatinine-Cr) were collected for the examination of urinary MCP-1, ICAM-1 and albumin (Alb) levels before and after the intensive insulin therapy. Changes in their levels were observed to test the hypothesis that type 2 diabetes with microalbuminuria is associated with elevated urinary concentrations of MCP-1 and ICAM-1, and intensive insulin therapy can result in a decline of Alb by reducing the inflammatory reaction. RESULTS The urinary MCP-1/Cr and urinary ICAM-1/Cr ratios in type 2 diabetic patients with microalbuminuria were much higher than those in normal controls, and intensive insulin treatment could decrease significantly the urinary MCP-1/Cr, ICAM-1/Cr and Alb/Cr ratios in type 2 diabetics with microalbuminuria. CONCLUSION Intensive insulin treatment may protect against renal injury in early DN by reducing the urinary MCP-1 and ICAM-1 excretions.
Collapse
|
165
|
Wang L, Shang H, Liu Y, Zheng M, Wu R, Phillips J, Bartels D, Deng X. A role for a cell wall localized glycine-rich protein in dehydration and rehydration of the resurrection plant Boea hygrometrica. PLANT BIOLOGY (STUTTGART, GERMANY) 2009; 11:837-48. [PMID: 19796361 DOI: 10.1111/j.1438-8677.2008.00187.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The acquisition of desiccation tolerance in dicotyledonous angiosperms requires the induction of a co-ordinated programme of genetic and biochemical processes during drying and the adaptive mechanisms are primarily protoplasmic in nature. Recent studies have shown that changes in cell wall structure and composition are also important for recovery after drying, however, the molecular mechanisms that underpin these adaptive responses are largely unknown. Here, the desiccation-tolerant plant Boea hygrometrica was used as a model system to investigate the changes in gene expression and cell wall adaptation that take place during extreme dehydration. A cDNA macroarry analysis of dehydration-inducible genes led to the identification of a gene encoding a glycine-rich protein (BhGRP1). The corresponding transcript was up-regulated during drying in B. hygrometrica leaves. In silico analysis revealed that BhGRP1 is targeted to the cell wall and this was confirmed in planta. Morphological changes in the cell wall architecture were also observed during the process of drying and re-watering. Concomitant with this observation, cell wall profiling by Fourier transform infrared spectroscopy indicated that protein levels increased upon desiccation and remained broadly similar upon re-watering. These findings suggest that the deposition of BhGRP1 may play a role in cell wall maintenance and repair during dehydration and rehydration in B. hygrometrica.
Collapse
|
166
|
Zhang R, Ma L, Zheng M, Ren J, Wang T, Meng Y, Zhao J, Jia L, Yao L, Han H, Li K, Yang A. Survivin knockdown by short hairpin RNA abrogates the growth of human hepatocellular carcinoma xenografts in nude mice. Cancer Gene Ther 2009; 17:275-88. [PMID: 19876077 DOI: 10.1038/cgt.2009.68] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Abnormal high activation of survivin is involved in carcinogenesis of various types of cancer. Survivin has been shown to promote cell proliferation in human hepatocellular carcinoma (HCC). Survivin-targeting approaches have become a promising strategy for treating HCC. Here, we used a reporter system to screen effective survivin siRNA sequences. The effect of vector-based survivin short hairpin RNA (shRNA) on the malignant phenotype of HCC cells in vitro and in vivo was determined, and an adenovirus-mediated shRNA expression vector was developed to decrease survivin expression of the established HCC tumor in nude mice. In vitro study showed that stable survivin knockdown inhibited cancer cell proliferation, enhanced apoptotic susceptibility, arrested cell cycle in the G1 phase and resulted in apparent mitotic catastrophe. Moreover, cells stably expressing survivin shRNA showed decreased tumorigenicity in nude mice. An additional in vivo study showed that intratumoral injection of adenovirus-delivered survivin shRNA suppressed tumor growth by spontaneous apoptosis of cancer cells and significantly prolonged animal survival. In conclusion, we proved the therapeutic potential of survivin shRNA for the treatment of HCC. And our results indicated that adenovirus-delivered shRNA may serve as a novel therapeutic for HCC.
Collapse
|
167
|
Zheng M, Shafer S, Liao G, Liu HH, Peltz G. Computational Genetic Mapping in Mice: The Ship Has Sailed. Sci Transl Med 2009; 1:3ps4. [DOI: 10.1126/scitranslmed.3000377] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
|
168
|
Zheng M, Wang J, Lubinski J, Flint OP, Krishna R, Yao M, Pursley JM, Thakur A, Boulton DW, Santone KS, Barten DM, Anderson JJ, Felsenstein KM, Hansel SB. Studies on the pharmacokinetics and metabolism of a gamma-secretase inhibitor BMS-299897, and exploratory investigation of CYP enzyme induction. Xenobiotica 2009; 39:544-55. [PMID: 19480557 DOI: 10.1080/00498250902928555] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BMS-299897 is a gamma-secretase inhibitor that was effective in reducing amyloid beta-peptide (A beta) in transgenic mice and guinea pigs. Therefore, pharmacokinetic and drug metabolism studies were conducted in animals to support its clinical development. The compound appeared to have low to intermediate total body clearance and was orally bioavailable (24-100%). The oral absorption of BMS-299897 from solid dosage forms appeared to be dissolution rate-limited. BMS-299897 was distributed into extravascular space (V(ss) >or= 1.3 l kg(-1)), including brain (brain-to-plasma ratio = 0.13-0.50). BMS-299897 appeared to be a P-glycoprotein (P-gp) substrate as the brain-to-plasma ratio was two-fold higher in the mdr1a knockout mouse as compared with the wild-type. Apparent autoinduction by BMS-299897 was observed in murine and rat efficacy and toxicity studies. In vitro, BMS-299897 was a weaker inducer of cytochrome P450 3A4 (CYP3A4) and a weaker transactivator of human pregnane X receptor (hPXR) as compared with rifampicin. Induction of human UGT1A and UGT2B was evaluated in primary human hepatocytes, but the results were inconclusive. A low potential for autoinduction in humans was predicted at a clinical dose of 250 mg and the prediction was consistent with the findings from a clinical multiple-dose study with BMS-299897 in probable Alzheimer's patients.
Collapse
|
169
|
Liang X, Zhou H, Tang Y, Yang X, Yang J, Zhu G, Zheng M, Zhang C. RNA interference targeting urokinase-type plasminogen activator receptor inhibits tumour growth of oral squamous cell carcinoma in vivo. Int J Oral Maxillofac Surg 2009. [DOI: 10.1016/j.ijom.2009.03.479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
170
|
Man XY, Yang XH, Cai SQ, Bu ZY, Wu XJ, Lu ZF, Zheng M. Expression and localization of vascular endothelial growth factor and vascular endothelial growth factor receptor-2 in human epidermal appendages: a comparison study by immunofluorescence. Clin Exp Dermatol 2009; 34:396-401. [PMID: 19309374 DOI: 10.1111/j.1365-2230.2008.03104.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND Vascular endothelial growth factor (VEGF) promotes angiogenesis and plays important roles in neovascularization and development of tissues. VEGF receptors (VEGFRs) are high-affinity receptors for VEGF and are originally considered specific to endothelial cells. We have previously shown that keratinocytes from human normal skin express VEGFRs. This poses the question of whether these receptors are also expressed by epidermal appendages, as epidermal appendages are lined with epithelial cells. OBJECTIVE To investigate the expression of VEGFR-2 compare with VEGF in epidermal appendages, including hair follicles, eccrine sweat glands and sebaceous glands. METHODS Monoclonal antibodies to VEGF and VEGFR-2 were used for immunohistochemical examination of cryostat-cut sections of normal human skin specimens from 11 donors undergoing cosmetic surgery. RESULTS Immunoreactivities for VEGF and VEGFR-2 principally showed parallel intense expression in anagen hair follicle (including outer root sheat, inner root sheath, dermal papillae epidermal matrix), sebaceous glands (ductal and secretory portions) and eccrine sweat glands (ductal and secretory portions), respectively. In particular, abundant expression of VEGF was found in the follicular basement membrane zone surrounding the bulb matrix and in the ductal and secretory portions of eccrine sweat glands. CONCLUSION A potential VEGF/VEGFR-2 autocrine pathway may be defined by the coexpression of VEGF and VEGFR-2 in human skin epidermal appendages.
Collapse
|
171
|
Cheng Y, He KB, Duan FK, Zheng M, Ma YL, Tan JH. Measurement of semivolatile carbonaceous aerosols and its implications: a review. ENVIRONMENT INTERNATIONAL 2009; 35:674-681. [PMID: 19201473 DOI: 10.1016/j.envint.2008.11.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2008] [Revised: 11/23/2008] [Accepted: 11/27/2008] [Indexed: 05/27/2023]
Abstract
Measurement of carbonaceous aerosols is complicated by positive and negative artifacts. An organic denuder with high efficiency for removing gaseous organics is an effective approach to eliminate the positive artifact, and it is a precondition for the accurate determination of SVOC by an adsorbent backup filter. Evaluations of different configurations of the organic denuder, and SVOC determined by different denuder-based samplers, both integrated and semi-continuous, are reviewed. A new equation for determination of the denuder efficiency is estimated, considering the efficiency of removing both the gaseous organics that could be adsorbed by the quartz and the gaseous passing through the quartz that could be subsequently adsorbed by the backup adsorbent filter. The origin of OC on the backup quartz filter, behind either quartz or Teflon filter, is quantitatively evaluated by the denuder-based method based on the data published. The backup-OC is shown to be dominated by either gaseous organics passing through the front filter or the evaporated particulate organic carbon depending on the sampling environment.
Collapse
|
172
|
Khripin C, Zheng M, Jagota A. Deposition and meniscus alignment of DNA–CNT on a substrate. J Colloid Interface Sci 2009; 330:255-65. [DOI: 10.1016/j.jcis.2008.10.073] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2008] [Revised: 10/15/2008] [Accepted: 10/24/2008] [Indexed: 11/17/2022]
|
173
|
Hochwald S, Nyberg C, Zheng M, Zheng D, Magis A, Ostrov D, Cance W, Golubovskaya V. 41: A Novel Small Molecule Inhibitor of FAK Decreases Growth of Human Pancreatic Cancer. J Surg Res 2009. [DOI: 10.1016/j.jss.2008.11.068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
174
|
Zheng M, Ng OT, Teo BW. Aortic and mitral valve endocarditis caused by Gemella morbillorum in a haemodialysis patient. Singapore Med J 2008; 49:e385-e387. [PMID: 19122942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Gemella morbillorum is part of the commensal flora of the upper respiratory tract, intestinal tract and genitourinary tract. On rare occasions, it causes endocarditis. We report a 67-year-old Chinese man with end-stage renal disease on maintenance intermittent haemodialysis, who developed Gemella morbillorum endocarditis complicated by severe aortic and mitral regurgitation. Most cases of Gemella morbillorum endocarditis have satisfactory outcomes with antibiotics or surgical treatment.
Collapse
|
175
|
Yang X, Chen P, Huang Y, Liu X, Zheng M, Zhang G, Xu R. The timing of first cleavage of different cloned and IVF embryos with oocytes recovered by ovum pickup. J Zool (1987) 2008. [DOI: 10.1111/j.1469-7998.2008.00490.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
176
|
Torrens ON, Zheng M, Kikkawa JM. Energy of K-momentum dark excitons in carbon nanotubes by optical spectroscopy. PHYSICAL REVIEW LETTERS 2008; 101:157401. [PMID: 18999637 DOI: 10.1103/physrevlett.101.157401] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2007] [Indexed: 05/27/2023]
Abstract
Phonon sideband optical spectroscopy determines the energy of the dark K-momentum exciton for (6,5) carbon nanotubes. One-phonon sidebands appear in absorption and emission, split by two zone-boundary (K-point) phonons. Their average energy locates the E11 K-momentum exciton 36 meV above the E11 bright level, higher than available theoretical estimates. A model for exciton-phonon coupling shows the absorbance sideband depends sensitively on the K-momentum exciton effective mass and has minimal contributions from zone-center phonons, which dominate the Raman spectra of carbon nanotubes.
Collapse
|
177
|
Ma J, Zheng M, Shen Y, Wang L, Wang L, Zhu Y, Zhang X. Effects of cilostazol on thrombospondin-1 (TSP-1) expression changes in the myocardium of diabetic rats. J Int Med Res 2008; 36:800-9. [PMID: 18652777 DOI: 10.1177/147323000803600423] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Myocardial protective effects of the phosphodiesterase 3 inhibitor, cilostazol, in streptozotocin-induced diabetic rats were investigated. Four weeks after induction of diabetes, we measured thrombospondin-1 (TSP-1) expression in the left ventricular myocardium. Microstructural and ultrastructural changes were also analysed. Four weeks after the induction of diabetes there were significant differences in body weight and blood glucose between the control, diabetic and cilostazol-treated diabetic animals. TSP-1 expression was significantly increased in the myocardium of diabetic rats compared with the control group. Although significantly higher than the control group, TSP-1 expression was significantly lower in the cilostazol group compared with the diabetes group. There were obvious ultrastructural changes in the myocardium of diabetic rats, which were rarely seen in cilostazol-treated diabetic rats. In conclusion, this study provides experimental evidence that cilostazol treatment of diabetic rats effectively prevents pathological myocardial alterations, possibly via the down-regulation of TSP-1 expression.
Collapse
|
178
|
Song D, Wang F, Dukovic G, Zheng M, Semke ED, Brus LE, Heinz TF. Direct measurement of the lifetime of optical phonons in single-walled carbon nanotubes. PHYSICAL REVIEW LETTERS 2008; 100:225503. [PMID: 18643430 DOI: 10.1103/physrevlett.100.225503] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2007] [Revised: 10/31/2007] [Indexed: 05/26/2023]
Abstract
Time-resolved anti-Stokes Raman spectroscopy has been applied to probe the dynamics of optical phonons created in single-walled carbon nanotubes by femtosecond laser excitation. From measurement of the decay of the anti-Stokes Raman signal in semiconducting nanotubes of (6,5) chiral index, a room-temperature lifetime for G-mode phonons of 1.1+/-0.2 ps has been determined. This lifetime, which reflects the anharmonic coupling of the G-mode phonons to lower-frequency phonons, is important in assessing the role of nonequilibrium phonon populations in high-field transport phenomena.
Collapse
|
179
|
Chou S, Son H, Zheng M, Saito R, Jorio A, Dresselhaus G, Dresselhaus M. Finite length effects in DNA-wrapped carbon nanotubes. Chem Phys Lett 2007. [DOI: 10.1016/j.cplett.2007.06.091] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
180
|
Giles FJ, le Coutre P, Bhalla K, Rosti G, Ossenkoppele G, Alimena G, Weitzman A, Zheng M, Kantarjian H. A phase II study of nilotinib administered to patients with imatinib resistant or intolerant chronic myelogenous leukemia (CML) in chronic phase (CP), accelerated phase (AP) or blast crisis (BC) who also failed dasatinib. J Clin Oncol 2007. [DOI: 10.1200/jco.2007.25.18_suppl.7038] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
7038 Background: Nilotinib and dasatinib are two new second generation tyrosine kinase inhibitors used in the treatment of imatinib-resistant/intolerant CML. There is limited data regarding the efficacy and safety of these therapies when given sequentially. Methods: This phase II open-label study was designed to evaluate the safety and efficacy of nilotinib at a dose of 400mg BID in CML-CP, -AP, and -BC pts who previously received and either failed or were intolerant to imatinib and dasatinib. Results: A total of 42 pts are reported - CP (16), AP (9), and BC (17 total; 13 myeloid, 4 lymphoid). Overall 10 (24%) pts had extramedullary disease at baseline. For all pts, median time from first diagnosis was 16.8 (0.6–265) months. The median duration of nilotinib exposure was 81 days with median dose intensity of 800mg/day. A total of 13 (31%) pts with dasatinib failure remain on treatment, 29 (69%) discontinued (6 for AEs, 16 for disease progression). CP: Of the 16 pts, 5 (31%) had a MCyR (3 complete, 2 partial). Complete hematologic response (CHR) was reported in 5/13 (39%) pts without CHR at baseline. Disease progression only occurred in 2 pts. AP: 2/9 (22%) pts had a return to chronic phase (RTC), 6 pts were not evaluable and there was 1 death. Disease progression occurred in 5 pts. BC: 3/17 (18%) achieved CHR, 1 (6%) had RTC, and 4 (24%) pts had disease progression. For all pts, the most common Grade 3/4 AEs reported were thrombocytopenia (26%), neutropenia (24%), and anemia (7%) pts. Conclusions: Nilotinib has significant clinical activity in CML-CP, AP, and BC patients who have failed imatinib and dasatinib. Nilotinib is safe and well tolerated, consistent with its kinase selectivity profile. No significant financial relationships to disclose.
Collapse
|
181
|
Zheng M, Iwasaki T, Friesen WO. Systems approach to modeling the neuronal CPG for leech swimming. CONFERENCE PROCEEDINGS : ... ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL CONFERENCE 2007; 2006:703-6. [PMID: 17271774 DOI: 10.1109/iembs.2004.1403255] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
This paper proposes a mathematical model of the neuronal central pattern generator (CPG) for leech swimming. The model is developed through the "systems approach" where dynamical components and their connections are first identified through input/output data from physiological experiments and then integrated into a chain of nonlinear oscillators. Our approach leads to a model of moderate complexity when compared with existing models developed through biophysical principles. We show through numerical simulations that our model can successfully reproduce the phase coordination observed in the isolated nerve cord of the leech CPG. As a byproduct, a prediction is obtained for the intrinsic period gradient along the nerve cord.
Collapse
|
182
|
Liu B, Hayes R, Yi Y, Mmbaga J, Checkel M, Zheng M. Three dimensional modelling of methane ignition in a reverse flow catalytic converter. Comput Chem Eng 2007. [DOI: 10.1016/j.compchemeng.2006.07.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
183
|
Jia Q, Zheng M, Zhu Y, Li J, Xu C. Effects of organophilic montmorillonite on hydrogen bonding, free volume and glass transition temperature of epoxy resin/polyurethane interpenetrating polymer networks. Eur Polym J 2007. [DOI: 10.1016/j.eurpolymj.2006.10.016] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
184
|
Cai F, Li C, Wu J, Min Q, Ouyang C, Zheng M, Ma S, Yu W, Lin F. Modulation of the oxidative stress and nuclear factor kappaB activation by theaflavin 3,3'-gallate in the rats exposed to cerebral ischemia-reperfusion. Folia Biol (Praha) 2007; 53:164-172. [PMID: 17976306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The major pathobiological mechanisms of IR injury include excitotoxicity, oxidative stress, and inflammation. TF3, a major constituent of black tea, possesses biological functions such as anti-oxidative and anti-inflammatory activities. The purpose of this study was to verify the neuronal protective potential of TF3 and its mechanisms against cerebral IR injury in rats. TF3 administration (10 and 20 mg.kg-1) ameliorated the infarct volume. TF3 also decreased the content of MDA and NO. TF3 significantly increased the activity of SOD and GSH-Px, which were reduced by IR injury. Administration of TF3 decreased mRNA and protein expression of COX-2 and iNOS. DNA binding and Western blotting revealed an increase in NF-kappaB activation and IkappaB depletion in IR brain tissue. Pretreatment with TF3 markedly inhibited IRinduced increase in nuclear localization of NF-kappaB, and preserved IkappaB in the cytoplasm. The results show that TF3 exerts protective effects against cerebral IR injury by reducing oxidative stress and modulating the NF-kappaB activation.
Collapse
|
185
|
Torrens ON, Milkie DE, Zheng M, Kikkawa JM. Photoluminescence from intertube carrier migration in single-walled carbon nanotube bundles. NANO LETTERS 2006; 6:2864-7. [PMID: 17163720 DOI: 10.1021/nl062071n] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Photoluminescence (PL) identifies spectroscopic signatures of intertube transfer of optically pumped carriers in single-walled carbon nanotube (SWNT) ensembles. Resonant photoexcitation of large band gap SWNTs produces strong PL from smaller band gap SWNTs. Magnetic alignment measurements associate the energy-transfer PL peaks with the formation of SWNT bundles, suggesting that efficient coupling results from physical contact.
Collapse
|
186
|
Zheng M, Friesen WO, Iwasaki T. Systems-level modeling of neuronal circuits for leech swimming. J Comput Neurosci 2006; 22:21-38. [PMID: 16998641 DOI: 10.1007/s10827-006-9648-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2005] [Revised: 06/07/2006] [Accepted: 06/30/2006] [Indexed: 10/24/2022]
Abstract
This paper describes a mathematical model of the neuronal central pattern generator (CPG) that controls the rhythmic body motion of the swimming leech. The systems approach is employed to capture the neuronal dynamics essential for generating coordinated oscillations of cell membrane potentials by a simple CPG architecture with a minimal number of parameters. Based on input/output data from physiological experiments, dynamical components (neurons and synaptic interactions) are first modeled individually and then integrated into a chain of nonlinear oscillators to form a CPG. We show through numerical simulations that the values of a few parameters can be estimated within physiologically reasonable ranges to achieve good fit of the data with respect to the phase, amplitude, and period. This parameter estimation leads to predictions regarding the synaptic coupling strength and intrinsic period gradient along the nerve cord, the latter of which agrees qualitatively with experimental observations.
Collapse
|
187
|
Gao L, Zheng M, Zhang B, Liu W. Polychlorinated dibenzo-p-dioxins and dibenzofurans in mussels and Gammarus spp. from Dongting Lake in People's Republic of China. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2006; 77:406-10. [PMID: 17033868 DOI: 10.1007/s00128-006-1080-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2006] [Accepted: 07/24/2006] [Indexed: 05/12/2023]
|
188
|
Chada S, Mhashilkar AM, Liu Y, Nishikawa T, Bocangel D, Zheng M, Vorburger SA, Pataer A, Swisher SG, Ramesh R, Kawase K, Meyn RE, Hunt KK. mda-7 gene transfer sensitizes breast carcinoma cells to chemotherapy, biologic therapies and radiotherapy: correlation with expression of bcl-2 family members. Cancer Gene Ther 2006; 13:490-502. [PMID: 16282987 DOI: 10.1038/sj.cgt.7700915] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Current therapies used in the treatment of breast cancer are limited by systemic toxicity, rapid drug metabolism and intrinsic and acquired drug resistance. We have previously shown that adenoviral-mediated transfer of the melanoma differentiation-associated gene-7 (mda-7) elicits growth inhibition and apoptosis in various tumor types. Here, we evaluate the effects of Ad-mda7, alone and in combination with other therapies, against a panel of nine breast tumor cell lines and their normal counterparts; we report selective Ad-mda7-mediated p53-independent growth inhibition, G2/M cell cycle arrest, and apoptosis. In vivo, Ad-mda7 induced p53-independent tumor growth inhibition (P<0.004) in multiple xenograft models. We then evaluated the combination of Ad-mda7 with agents commonly used to treat breast cancer: radiotherapy (XRT), Tamoxifen, Taxotere, Adriamycin, and Herceptin. These agents exhibit diverse modes of action, including formation of bulky adducts, inhibition of DNA replication (Adriamycin, XRT), damage to microtubules (Taxotere), nonsteroidal estrogen antagonists (Tamoxifen), or Her2/neu receptor blockade (Herceptin). Treated with conventional anticancer drugs or radiation, MDA-7-expressing cells display additive or synergistic cytotoxicity and apoptosis that correlates with decreased BCL-2 expression and BAX upregulation. In vivo, animals that received Ad-mda7 and XRT underwent significant reduction of tumor growth (P<0.002). This is the first report of the synergistic effects of Ad-mda7 combined with chemotherapy or radiotherapy on human breast carcinoma cells.
Collapse
|
189
|
Luo J, Zheng M, Zhao X, Huo C, Yang L. Simplified expression for estimating release rate of hazardous gas from a hole on high-pressure pipelines. J Loss Prev Process Ind 2006. [DOI: 10.1016/j.jlp.2005.06.029] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
190
|
Bocangel D, Zheng M, Mhashilkar A, Liu Y, Ramesh R, Hunt KK, Chada S. Combinatorial synergy induced by adenoviral-mediated mda-7 and Herceptin in Her-2+ breast cancer cells. Cancer Gene Ther 2006; 13:958-68. [PMID: 16783343 DOI: 10.1038/sj.cgt.7700972] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The melanoma differentiation-associated gene-7 (mda-7) is a member of the interleukin-10 cytokine family and a novel tumor suppressor gene. Adenoviral-mediated mda-7 (Ad-mda7) gene transfer has tumor-specific growth inhibitory and proapoptotic effects in a broad spectrum of cancer cells. In breast cancer cells, adenoviral-induced mda-7 expression triggers antiproliferative effects by downregulation of survival signals, such as Bcl-2 and Akt. The anti-human epidermal growth factor receptor-2 (Her-2) monoclonal antibody, Trastuzumab (Herceptin), increases the sensitivity of Her-2/neu-overexpressing breast cancer cells to chemotherapeutic agents and radiotherapy. In this study, we evaluate the effects of treatment with Ad-mda7 and Herceptin combination therapy in a panel of Her-2/neu-overexpressing cell lines, and in established tumors in nude mice. Compared to individual treatments, the combination of Ad-mda7 and Herceptin elicits supra-additive antitumor activity in Her-2/neu-overexpressing tumor cell lines: increased cell death, cell cycle block and apoptosis. The Ad-mda7 and Herceptin interaction was shown to be synergistic by isobologram analysis. Ad-mda7 does not alter cell surface Her-2/neu levels, but the combination of Ad-mda7+Herceptin results in increased expression of cell surface E-cadherin with concomitant translocation of beta-catenin from the nucleus to the cell membrane. In vivo, the combination of Ad-mda7 and Herceptin showed significantly increased antitumor activity (P<0.003) against Her-2/neu-overexpressing tumors. These data suggest that the combination of Ad-mda7 with Herceptin may be a novel therapy for breast cancer patients whose tumors overexpress Her-2/neu. The observed synergistic effect may improve treatment options for otherwise poorly responsive, Her-2-positive, breast cancer patients.
Collapse
|
191
|
Turan Y, Zheng M. Purification and characterization of an intracellular beta-glucosidase from the methylotrophic yeast Pichia pastoris. BIOCHEMISTRY (MOSCOW) 2006; 70:1363-8. [PMID: 16417459 DOI: 10.1007/s10541-005-0270-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Pichia pastoris beta-glucosidase was purified to apparent homogeneity by salting out with ammonium sulfate, gel filtration, and ion-exchange chromatography with Q-Sepharose and CM-Sepharose. The enzyme is a tetramer (275 kD) made up of four identical subunits (70 kD). The pH optimum is 7.3, and it is fairly stable in the pH range 5.5-9.5. The temperature optimum is 40 degrees C. The purified beta-glucosidase is effectively active on p-/o-nitrophenyl-beta-D-glucopyranosides (p-/o-NPG) and 4-methylumbelliferyl-beta-D-glucopyranoside (4-MUG) with Km values of 0.12, 0.22, and 0.096 mM and Vmax values of 10.0, 11.7, and 6.2 micromol/min per mg protein, respectively. It also exhibits different levels of activity against p-nitrophenyl-1-thio-beta-D-glucopyranoside, cellobiose, gentiobiose, amygdalin, prunasin, salicin, and linamarin. The enzyme is competitively inhibited by gluconolactone, p-/o-nitrophenyl-beta-D-fucopyranosides (p-/o-NPF), and glucose against p-NPG as substrate. o-NPF is the most effective inhibitor of the enzyme activity with Ki value of 0.41 mM. The enzyme is more tolerant to glucose inhibition with Ki value of 7.2 mM for p-NPG. Pichia pastoris has been employed as a host for the functional expression of heterologous beta-glucosidases and the risk of high background beta-glucosidase activity is discussed.
Collapse
|
192
|
Iwasaki T, Zheng M. Sensory feedback mechanism underlying entrainment of central pattern generator to mechanical resonance. BIOLOGICAL CYBERNETICS 2006; 94:245-61. [PMID: 16404611 DOI: 10.1007/s00422-005-0047-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2005] [Accepted: 11/21/2005] [Indexed: 05/06/2023]
Abstract
Rhythmic body motions observed in animal locomotion are known to be controlled by neuronal circuits called central pattern generators (CPGs). It appears that CPGs are energy efficient controllers that cooperate with biomechanical and environmental constraints through sensory feedback. In particular, the CPGs tend to induce rhythmic motion of the body at a natural frequency, i.e., the CPGs are entrained to a mechanical resonance by sensory feedback. The objective of this paper is to uncover the mechanism of entrainment resulting from the dynamic interaction of the CPG and mechanical system. We first develop multiple CPG models for the reciprocal inhibition oscillator (RIO) and examine through numerical experiments whether they can be entrained to a simple pendulum. This comparative study identifies the neuronal properties essential for the entrainment. We then analyze the simplest model that captures the essential dynamics via the method of harmonic balance. It is shown that robust entrainment results from a strong, positive-feedback coupling of a lightly damped mechanical system and the RIO consisting of neurons with the complete adaptation property.
Collapse
|
193
|
Wang D, Li H, Yuan H, Zheng M, Bai C, Chen L, Pei X. Humanin delays apoptosis in K562 cells by downregulation of P38 MAP kinase. Apoptosis 2006; 10:963-71. [PMID: 16151632 DOI: 10.1007/s10495-005-1191-x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Humanin (HN) is a newly identified neuroprotective peptide. In this study, we investigated its antiapoptotic effect and the potential mechanisms in K562 cells. Upon serum deprivation, expression of HN in K562 cells decreased and its intracellular distribution changed from cytoplasm to cell membrane. In HN stably transfected K562 cells, apoptosis was delayed compared with control vector transfected cells as measured by flow cytometry. Furthermore, analysis of different mitogen-activated protein (MAP) kinases activity revealed that extracellular signal-regulated kinase (ERK) pathway was inhibited while p38 signaling was activated following serum deprivation in K562 cells. And in HN transfected K562 cells, ERK downregulation was not affected, but p38 activation was suppressed, which may responsible for the delayed apoptosis in these cells. Activation of the ERK signaling pathway by phorbol myristate 13-acetate (PMA) and sorbitol protected K562 cells from serum deprivation induced apoptosis. Additionally, overexpression of HN reduced megakaryocytic differentiation of K562 cells. The present data outline the role of ERK and p38 MAP kinases in serum deprivation induced apoptosis in K562 cells and figure out p38 signaling pathway as molecular target for HN delaying apoptosis in K562 cells.
Collapse
|
194
|
Zhang Z, Zheng M, Bindas J, Schwarzenberger P, Kolls J. Critical Role of Interleukin-17 and Interleukin-17 Receptor Signaling in Tnbs-Induced Colitis. J Investig Med 2006. [DOI: 10.1177/108155890605401s152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
195
|
Zhang Z, Zheng M, Bindas J, Schwarzenberger P, Kolls JK. 4 CRITICAL ROLE OF INTERLEUKIN-17 AND INTERLEUKIN-17 RECEPTOR SIGNALING IN Trinitrobenzene Sulfonic Acid-INDUCED COLITIS. J Investig Med 2006. [DOI: 10.2310/6650.2005.x0004.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
196
|
Jia QM, Zheng M, Xu CZ, Chen HX. The mechanical properties and tribological behavior of epoxy resin composites modified by different shape nanofillers. POLYM ADVAN TECHNOL 2006. [DOI: 10.1002/pat.710] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
197
|
Zhang Z, Zheng M, Bindas J, Schwarzenberger P, Kolls JK. 269 CRITICAL ROLE OF INTERLEUKIN-17 AND INTERLEUKIN-17 RECEPTOR SIGNALING IN TNBS-INDUCED COLITIS. J Investig Med 2006. [DOI: 10.2310/6650.2005.x0004.268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
198
|
Wood D, Robertson B, Zheng M, Fick D, Ackland T. 363 Advances in the treatment of chondral defects of the knee using autologous chondrocyte implantation. J Sci Med Sport 2005. [DOI: 10.1016/s1440-2440(17)30860-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
199
|
Weibing X, Jun L, Zheng M, Fengtao Y, Hexiang Z. Effect of 2.1 MPa and 4.1 MPa H2O2 exposure on auditory brain stem evoked potential in mice. Undersea Hyperb Med 2005; 32:391-6. [PMID: 16457087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Brain auditory evoked potential (BAEP) in mice exposed to hyperbaric H2O2 pressure was monitored to reveal the correlation between altered synaptic transmission and hydrogen narcosis or isobaric HPNS. Inter peak latencies and wave amplitudes were selected as indices of assessment. The animals were exposed either to He-O2 or H2-O2 at 2.1 MPa and 4.1 MPa. Results showed that synaptic transmission was inhibited to various extents. The inhibition was partly due to the narcotic effect of hydrogen, which was added to the effect caused by hydrostatic pressure. On the other hand, asymmetrical reaction of each segment in the neuro-network might be responsible for the occurrence of HPNS.
Collapse
|
200
|
Borek D, Chen Y, Zheng M, Otwinowski Z. High symmetry involved in cellular regulation. Acta Crystallogr A 2005. [DOI: 10.1107/s0108767305089774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|