Biomedical subjects

Z Zhu

Publications and source records attributed to Z Zhu.

At least 145 records · Page 8Linked to original sources

PubMed2000

Preliminary study of the in vitro growth inhibition of human bladder cancer cell line BIU-87 by arsenic trioxide.

To study the effects of arsenic trioxide (As2O3) on the in vitro growth of human bladder cancer cells and the mechanisms. The growth inhibition rates of human bladder cancer cell line BIU-87 by various concentrations of As2O3 were detected by using MTT method. Cell apoptosis was detected by in situ terminally labeled transferase technique and bcl-2 gene expression of BIU-87 cells was observed by SABC immunohistochemical method. The results showed that As2O3 could inhibit the growth of BIU-87 effectively in a dose-dependent manner. After drug's action, the apoptotic bladder cancer cells were obviously increased, which depended on the prolongation of the action time and Bcl-2 expression of BIU-87 cells was decreased significantly. It was suggested that As2O3 could significantly inhibit the growth of bladder human cancer cells. Inducing cell apoptosis by down-regulating the expression of bcl-2 gene might be one of its action mechanisms.

Antineoplastic Agents↗

PubMed2000

Effect of anoxic preconditioning on ATP-sensitive potassium channels in guinea-pig ventricular myocytes.

Ischemic or hypoxic preconditioning in experimental animals and humans is described. The mechanism of preconditioning may involve several endogenous substances released from ischemic or hypoxic tissues (such as adenosine, noradrenaline and bradykinin) that stimulate protein kinase C (PKC), which then phosphorylates ATP-sensitive potassium channels (K(ATP) channels). However, the effect of hypoxic preconditioning on K(ATP) channels in guinea-pig ventricular myocytes is unclear. The uncoupler carbonyl cyanide p-(trifluoromethoxy)phenylhydrazone (FCCP) has been shown to activate K(ATP) channels in isolated cardiac cells. In the present study we tested whether anoxic preconditioning (APC) could affect the opening of K(ATP) channels activated by metabolic inhibition (MI) induced by FCCP in cell-attached and inside-out patches from guinea-pig ventricular myocytes. We measured the channel activity as NP(o)i and calculated it using the formula Po=I/(Ni), where Po is open-state probability, I is the mean patch current carried by all K(ATP) channels activated in a particular patch for a certain period of time, N is the number of functioning channels in the patch, and i is the unitary current of the K(ATP) channels. In cell-attached membrane patches, after about 5 min of initiating MI, K(ATP) channels were activated at a holding potential of +40 mV (NP(o)i=3.70+/-0.9 pA); APC pretreatment (3 min of anoxia followed by 7 min of reoxygenation) before MI (APC+MI group) shortened the time to activate K(ATP) channels by MI (2.3+/-0.5 min) and increased the activity of K(ATP)currents (NP(o)i=8.4+/-0.5 pA). This effect of APC was eliminated by administration of a PKC blocker, chelerythrine (5 microM), for 5 min before the APC pretreatment. In the inside-out patches, the IC50 of intracellular ATP against the K(ATP) channels in the APC+MI group was significantly increased to 642 microM compared to that in the MI group (IC50 of intracellular ATP =252 microM). Chelerythrine inhibited the effect of APC on the sensitivity of K(ATP) channels to the intracellular ATP concentration (IC50 of [ATP]i=301 microM). Our results demonstrate that APC can increase and accelerate the opening of K(ATP) channels induced by MI, and decrease the sensitivity of K(ATP) channels to [ATP]i, which is mediated by promoting the activation of PKC induced by APC.

Adenosine Triphosphate↗

PubMed2000

IL-11 expression is increased in severe asthma: association with epithelial cells and eosinophils.

BACKGROUND: IL-11 is a pleiotropic cytokine produced by a variety of stromal cells. Targeted overexpression of this cytokine in mice results in a remodeling of the airways and the development of airway hyperresponsiveness and airway obstruction. OBJECTIVES: Because these alterations mimic important pathologic and physiologic changes in the airways of some asthmatic patients, we investigated the expression of IL-11 messenger RNA (mRNA) within the airways of patients with mild to severe asthma and nonasthmatic control subjects. METHODS: Fiberoptic bronchoscopy to obtain bronchial biopsy specimens was performed on patients with mild (n = 13), moderate (n = 10), and severe (n = 9) asthma and on nonasthmatic control subjects (n = 9). RESULTS: These patients differed in their extent of airway fibrosis with types I and III collagens being noted in greater quantities in the biopsy specimens from the severe and moderate asthmatics than in those from controls (P <.05). IL-11 mRNA expression was observed in the epithelial and subepithelial layers of asthmatic and nonasthmatic control subjects. The number of cells within the epithelium and subepithelium expressing IL-11 mRNA was greater in those with moderate and severe asthma compared with mild asthma and nonasthmatic subjects (P <.001). There were also greater numbers of IL-11 mRNA-positive cells within the subepithelium in severe compared with moderate asthma (P <.001). Immunostaining for IL-11 within the airway tissues confirmed translation of the mRNA into IL-11-immunoreactive protein in airway epithelial cells. Colocalization of IL-11 mRNA and immunoreactivity with resident inflammatory cells demonstrated that this cytokine was also expressed by major basic protein-positive eosinophils. CONCLUSION: These results suggest that IL-11 is involved in the chronic remodeling seen in asthmatic airways and is associated with increasing severity of the disease.

Asthma↗

PubMed2000

Sonic hedgehog--regulated oligodendrocyte lineage genes encoding bHLH proteins in the mammalian central nervous system.

During development, basic helix-loop-helix (bHLH) proteins regulate formation of neurons from multipotent progenitor cells. However, bHLH factors linked to gliogenesis have not been described. We have isolated a pair of oligodendrocyte lineage genes (Olg-1 and Olg-2) that encode bHLH proteins and are tightly associated with development of oligodendrocytes in the vertebrate central nervous system (CNS). Ectopic expression of Olg-1 in rat cortical progenitor cell cultures promotes formation of oligodendrocyte precursors. In developing mouse embryos, Olg gene expression overlaps but precedes the earliest known markers of the oligodendrocyte lineage. Olg genes are expressed at the telencephalon-diencephalon border and adjacent to the floor plate, a source of the secreted signaling molecule Sonic hedgehog (Shh). Gain- and loss-of-function analyses in transgenic mice demonstrate that Shh is both necessary and sufficient for Olg gene expression in vivo.

Age Factors↗

PubMed2000

Creation of polarized cells coexpressing CYP3A4, NADPH cytochrome P450 reductase and MDR1/P-glycoprotein.

PURPOSE: To develop model polarized cell systems expressing cytochrome P4503A4. NADPH P450 reductase, and P-glycoprotein (Pgp). METHODS: LLC-PK1 and derivative L-MDR1 cells stably expressing Pgp, the product of the multidrug resistance gene (MDR1), were transfected stably using either a mammalian neomycin selectable expression vector (CYP3A4-Neo) or an episomal vector based on Epstein-Barr virus (CYP3A4-Hygro). These CYP3A4 expressing cells were compared with LLC-PK1, L-MDR1, or Caco-2 cells transduced with Adenovirus-3A4 vector (Ad3A4) with or without simultaneous Adenovirus-P450 Reductase (AdRed) transduction. Cells were characterized for expression of CYP3A4 protein and CYP3A4 mediated metabolism towards midazolam and testosterone. Analysis of membrane integrity and drug transport assays were performed to determine whether infection with recombinant Ad3A4 +/- AdRed affected Pgp function. RESULTS: The rank order of optimal CYP3A4 expression and activities in LLC-PKI and L-MDR1 cells from highest to lowest was cells cotransduced with Ad3A4 plus AdRed >> Ad3A4 >>> CYP3A4-Hygro > CYP3A4-Neo. Similarly, coexpression of Ad3A4 plus AdRed led to enhanced CYP3A4 mediated metabolism in Caco-2 cells over cells with Ad3A4 alone. Incubation of transwell cultured cells expressing Ad3A4/AdRed with midazolam led to readily detectable metabolite in the medium. In microsomes from Caco-2 and LLC-PK1 cells, each co-transduced with Ad3A4/AdRed, Vmax values for testosterone 6beta-hydroxylase activity ranged from 414 to 1350 pmoles/min/mg, respectively. For either Caco-2 or LLC-MDR1 cells, TEER values and the rate of apical to basal and basal to apical transport of vinblastine or digoxin were similar in cells with and without Ad3A4/Red transduction. CONCLUSIONS: Polarized cellular systems coexpressing Ad3A4, AdRed, and the MDR1/Pgp transporter were developed and characterized. The results document the utility of these polarized model systems for simultaneous drug transport/drug metabolism studies. Since the experimental approach can be adapted to study the interplay of multiple enzyme/ transporting systems, it may find significant application as a screening tool for the pharmaceutical industry and as a more basic research tool to study the kinetics of intestinal drug bioavailability.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2000

Galectin-1 and galectin-3 in chronic pancreatitis.

Galectin-1 and galectin-3 have important functions in cell-cell interactions, cell adhesion to extracellular matrix, the organization of extracellular matrix, and tissue remodeling. To assess their potential role in chronic pancreatitis (CP), we examined their expression by Northern blot analysis, in situ hybridization, immunohistochemistry, and Western blot analysis in normal and CP pancreatic tissues. Northern blot analysis revealed a 4.5-fold increase of galectin-1 mRNA (p < 0.01) and a 3.8-fold increase of galectin-3 mRNA (p < 0.01) in CP samples compared with normal controls. In situ hybridization analysis of normal pancreas indicated low abundance of galectin-1 mRNA in fibroblasts, whereas galectin-3 mRNA was moderately present in ductal cells. CP samples exhibited moderate to intense galectin-1 mRNA signals in fibroblasts, whereas galectin-3 mRNA signals were intense in the cells of ductular complexes and weak in the degenerating acinar cells. In addition, intense galectin-1 and galectin-3 mRNA signals were present in nerves of normal and CP samples. Immunohistochemistry showed a distribution pattern of galectin-1 and galectin-3 similar to that described for in situ hybridization. Relative quantification of galectin-1 and galectin-3 protein by immunoblotting revealed an increase of 3.2-fold and 3.0-fold, respectively, in CP compared with normal controls. There was a significant correlation between galectin-1 and fibrosis and between galectin-3 and fibrosis and the density of ductular complexes. Up-regulation of galectin-1 in fibroblasts and galectin-3 in ductular complexes suggests a role of these lectins in tissue remodeling in CP. Galectin-1 might participate in ECM changes, whereas galectin-3 seems to be involved in both ECM changes and ductular complex formation.

Adult↗

PubMed2000

Umbilical cord blood transplantation from unrelated HLA-matched donor in an adult with severe aplastic anemia.

A 23-year-old male suffering from severe aplastic anemia (SAA) weighing 60 kg was successfully treated by unrelated allo-CBSCT (cord blood stem cell transplantation). A six-loci HLA-identical umbilical cord blood (UCB) was infused after conditioning with low-dose cyclophosphamide (CTX) and antilymphocyte globulin (ALG). The prophylaxis of GVHD consisted of CsA and MTX. The infused cord blood provided 1.89 x 10(7) nucleated cells per kg, CD34-positive cells: 0.89%. Neutrophils >0.5 x 10(9)/l were reached 10 days after transplant, and platelets greater than 50.0 x 10(9)/l at day 26. RBC and platelet transfusion independence were reached on days 15 and 18. The patient developed grade 1 skin GVHD 10 months after engraftment of the donor cells. Microsatellite DNA fingerprinting indicated a stable and persistent donor-recipient mixed chimerism, whilst the circulating red cells remain of host origin.

Adult↗

PubMed2000

High prevalence of complement component C6 deficiency among African-Americans in the south-eastern USA.

Complement component C6 is a part of the membrane attack complex that forms a pore-like structure in cell membranes following complement activation. Deficiency of terminal complement components including C6 predisposes individuals to infection with Neisseriae. Using polymerase chain reaction/single-strand conformation polymorphism analysis followed by DNA sequencing, we screened genomic DNA from 200 randomly chosen blacks and an equal number from whites for three loss-of-function C6 mutations. Ten blacks and two whites were found to be heterozygous for one of the mutations. Two of the mutations, 1195delC and 1936delG, were found exclusively in black individuals. A third previously undescribed mutation, 878delA, was found at equal frequency among the two groups. The difference between the two groups was significant (P = 0.027), indicating that C6 deficiency due to these three mutations is more common among blacks than whites in the local area, principally Jefferson County, Alabama. In addition, three previously undescribed point mutations, two of which result in amino acid substitutions, were identified within exon 6. A review of the county health department records over the past 6 years revealed a higher incidence of meningococcal meningitis in blacks due to serogroups Y and W-135 which paralleled the difference in the estimated prevalence of C6 deficiency. Among black residents of the county (n = 235 598) there were 15 cases of meningitis due to these two serogroups, compared with two cases in the white population (n = 422 604) (P = 0.002). We conclude that C6 deficiency is more common among blacks than whites in the south-eastern United States, with a frequency approaching 1 in 1600 black individuals.

Amino Acid Sequence↗

PubMed2000

An efficient route to the production of an IgG-like bispecific antibody.

Production of IgG-form bispecific antibody (BsAb-IgG) by co-expressing two antibodies in transfected cells is often inefficient owing to the unwanted pairing between the component heavy and light chains. We have developed an efficient method for the production of a novel IgG-like BsAb by using the natural dimerization mechanism between IgG heavy and light chains. Two single-chain Fv (scFv) of different specificity are fused to the constant domain of human kappa chain (C(L)) and the first constant domain of human heavy chain (C(H1)), to form two polypeptides, (scFv)(1)-C(L) and (scFv)(2)-C(H1)-C(H2)-C(H3), respectively. Co-expression of the two polypeptides in mammalian cells results in the formation of a covalently linked IgG-like hetero-tetramer, Bs(scFv)(4)-IgG, with dual specificity. Our approach yields a homogeneous bispecific IgG-like antibody product with each molecule containing four antigen binding sites, two for each of its target antigens. A Bs(scFv)(4)-IgG was prepared using two scFv antibodies each directed against a different epitope of a vascular endothelial growth factor receptor, the kinase insert domain-containing receptor (KDR). The Bs(scFv)(4)-IgG is capable of simultaneously binding to the two epitopes on the receptor. Further, the Bs(scFv)(4)-IgG also retains the antigen-binding efficacy and biological activity of its component antibodies.

Amino Acid Sequence↗

PubMed2000

Trafficking of varicella-zoster virus glycoprotein gI: T(338)-dependent retention in the trans-Golgi network, secretion, and mannose 6-phosphate-inhibitable uptake of the ectodomain.

The trans-Golgi network (TGN) is putatively the site where varicella-zoster virus is enveloped. gE is targeted to the TGN by selective retrieval from the plasmalemma in response to signaling sequences in its endodomain. gI lacks these sequences but forms a complex with gE. We now find that gI is targeted to the TGN and plasma membrane when expressed in Cos-7 cells; nevertheless, surface labeling revealed that gI is not retrieved from the plasma membrane. TGN targeting of gI depended on the T(338) of its endodomain and was lost when T(338) was deleted or mutated to A, S, or D. The endodomain of gI was sufficient, if it contained T(338), to target a fusion protein containing the ectodomain of the human interleukin-2 receptor to the TGN. A truncated protein consisting only of the gI ectodomain was secreted and taken up by nontransfected cells. This uptake of the secreted gI ectodomain was blocked by mannose 6-phosphate. Following cotransfection, both gI and gE were retrieved to the TGN from the plasma membrane in 26.7% of cells, neither gI nor gE was internalized in 18.3%, and gE was retrieved to the TGN while gI remained at the plasma membrane in 55%. We suggest that the T(338) of its endodomain is necessary to retain gI in the TGN; moreover, because gI and gE interact, the signaling sequences of each glycoprotein reinforce one another in ensuring that both glycoproteins are concentrated in the TGN yet remain on the cell surface.

Amino Acid Sequence↗

PubMed2000

Airway hyperresponsiveness and airway obstruction in transgenic mice. Morphologic correlates in mice overexpressing interleukin (IL)-11 and IL-6 in the lung.

Understanding the sources of variation in airway reactivity and airflow is important for unraveling the pathophysiology of asthma, obstructive lung disease, and other pulmonary disorders. Transgenic expression of two closely related cytokines in the mouse lung produced opposite effects on these parameters. Interleukin (IL)-6 did not alter basal airways resistance and decreased methacholine responsiveness, whereas IL-11 caused airways obstruction and increased airway responses to methacholine. To clarify these differences we examined histologic sections and used morphometry to compare bronchiolar and parenchymal dimensions in 1- to 2-mo-old transgenic mice expressing IL-6 or IL-11 and littermate control mice. Both transgenic strains showed similar emphysema-like airspace enlargement, nodular peribronchiolar collections of mononuclear cells, thickening of airway walls, and subepithelial airway fibrosis. When compared with littermate control mice, the IL-6 mice showed an approximately 50% increase in the caliber of their bronchioles and an increase in airway wall thickness that was in proportion to the increase in the size of their airways. In contrast, the remodeling response was more robust in the IL-11 transgenic mice. It was also seen in airways with normal external and luminal diameters and thus was out of proportion to the caliber of their airways. These results support the hypothesis that structural alterations and resulting caliber changes of respiratory airways can have important effects on airway physiology and reactivity.

Airway Obstruction↗

PubMed2000

Respiratory syncytial virus stimulation of vascular endothelial cell growth Factor/Vascular permeability factor.

We hypothesized that respiratory syncytial virus (RSV)-induced pathologies could be mediated, in part, by vascular active cytokines elaborated during virus infection. To address this hypothesis, we determined whether RSV stimulated vascular endothelial cell growth factor (VEGF)/vascular permeability factor (VPF) elaboration in vitro. Supernatants from unstimulated A549 cells and normal human bronchial epithelial cells contained modest levels of VEGF. In contrast, supernatants from RSV-infected cells contained elevated levels of VEGF/VPF. This stimulation was seen after as little as 2 h, was still prominent after 48 h, and, by immunoblot, was specific for the 165- and 121-amino acid isoforms of VEGF/VPF. It was not associated with significant cell cytotoxicity or alterations in VEGF messenger RNA. It did, however, require new protein biosynthesis. In accordance with these findings, the 165- and 121-amino acid isoforms of VEGF/VPF were also found in the nasal washings from patients with RSV infections. These studies demonstrate that RSV is a potent stimulator of VEGF/VPF elaboration and that, in vitro, this stimulation is mediated via a noncytotoxic translational and/or post-translational biosynthetic mechanism. VEGF/VPF may play an important role in the pathogenesis of RSV-induced disorders.

Cell Line↗

PubMed2000

Inducible targeting of IL-13 to the adult lung causes matrix metalloproteinase- and cathepsin-dependent emphysema.

Cigarette smoke exposure is the major cause of chronic obstructive pulmonary disease (COPD). However, only a minority of smokers develop significant COPD, and patients with asthma or asthma-like airway hyperresponsiveness or eosinophilia experience accelerated loss of lung function after cigarette smoke exposure. Pulmonary inflammation is a characteristic feature of lungs from patients with COPD. Surprisingly, the mediators of this inflammation and their contributions to the pathogenesis and varied natural history of COPD are not well defined. Here we show that IL-13, a critical cytokine in asthma, causes emphysema with enhanced lung volumes and compliance, mucus metaplasia, and inflammation, when inducibly overexpressed in the adult murine lung. MMP-2, -9, -12, -13, and -14 and cathepsins B, S, L, H, and K were induced by IL-13 in this setting. In addition, treatment with MMP or cysteine proteinase antagonists significantly decreased the emphysema and inflammation, but not the mucus in these animals. These studies demonstrate that IL-13 is a potent stimulator of MMP and cathepsin-based proteolytic pathways in the lung. They also demonstrate that IL-13 causes emphysema via a MMP- and cathepsin-dependent mechanism(s) and highlight common mechanisms that may underlie COPD and asthma.

Animals↗

PubMed2000

Autocrine stimulation of VEGFR-2 activates human leukemic cell growth and migration.

Emerging data suggest that VEGF receptors are expressed by endothelial cells as well as hematopoietic stem cells. Therefore, we hypothesized that functional VEGF receptors may also be expressed in malignant counterparts of hematopoietic stem cells such as leukemias. We demonstrate that certain leukemias not only produce VEGF but also express functional VEGFR-2 in vivo and in vitro, resulting in the generation of an autocrine loop that may support leukemic cell survival and proliferation. Approximately 50% of freshly isolated leukemias expressed mRNA and protein for VEGFR-2. VEGF(165) induced phosphorylation of VEGFR-2 and increased proliferation of leukemic cells, demonstrating these receptors were functional. VEGF(165) also induced the expression of MMP-9 by leukemic cells and promoted their migration through reconstituted basement membrane. The neutralizing mAb IMC-1C11, specific to human VEGFR-2, inhibited leukemic cell survival in vitro and blocked VEGF(165)-mediated proliferation of leukemic cells and VEGF-induced leukemic cell migration. Xenotransplantation of primary leukemias and leukemic cell lines into immunocompromised nonobese diabetic mice resulted in significant elevation of human, but not murine, VEGF in plasma and death of inoculated mice within 3 weeks. Injection of IMC-1C11 inhibited proliferation of xenotransplanted human leukemias and significantly increased the survival of inoculated mice. Interruption of signaling by VEGFRs, particularly VEGFR-2, may provide a novel strategy for inhibiting leukemic cell proliferation.

Animals↗

PubMed2000

IL-13 stimulates vascular endothelial cell growth factor and protects against hyperoxic acute lung injury.

Hyperoxia is an important cause of acute lung injury. To determine whether IL-13 is protective in hyperoxia, we compared the survival in 100% O(2) of transgenic mice that overexpress IL-13 in the lung and of nontransgenic littermate controls. IL-13 enhanced survival in 100% O(2). One hundred percent of nontransgenic mice died in 4-5 days, whereas 100% of IL-13-overexpressing mice lived for more than 7 days, and many lived 10-14 days. IL-13 also stimulated VEGF accumulation in mice breathing room air, and it interacted with 100% (2) to increase VEGF accumulation further. The 164-amino acid isoform was the major VEGF moiety in bronchoalveolar lavage from transgenic mice in room air, whereas the 120- and 188-amino acid isoforms accumulated in these mice during hyperoxia. In addition, antibody neutralization of VEGF decreased the survival of IL-13-overexpressing mice in 100% (2). These studies demonstrate that IL-13 has protective effects in hyperoxic acute lung injury. They also demonstrate that IL-13, alone and in combination with 100% (2), stimulates pulmonary VEGF accumulation, that this stimulation is isoform-specific, and that the protective effects of IL-13 are mediated, in part, by VEGF.

Animals↗

PubMed2000

Nonperturbative analysis of cross coupling in corrugated metal films.

There has been a recent renewal of interest in anomalously high energy transfer through otherwise opaque metal film geometries. One of the earliest such systems, that of surface plasmon cross coupling in a sinusoidally corrugated continuous metal film, was studied by Gruhlke et al. [Phys. Rev. Lett. 56, 2838 (1986)]. We show that it is possible to use a nonperturbative method to accurately predict this coupling, and we use this method to analyze both intrinsic coupling in symmetric structures and grating-assisted cross coupling in asymmetric structures.

Journal Article↗

PubMed2000

The difference in the carboxy-terminal sequence is responsible for the difference in the activity of chicken and rat liver fructose-2,6-bisphosphatase.

The fructose-2,6-bisphosphatase domain of the bifunctional chicken liver enzyme 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase shares approximately 95% amino acid sequence homology with that of the rat enzyme. However, these two enzymes are significantly different in their phosphatase activities. In this report, we show that the COOH-terminal 25 amino acids of the two enzymes are responsible for the different enzymatic activities. Although these 25 amino acids are not required for the phosphatase activity, their removal diminishes the differences in the activities between the two enzymes. In addition, two chimeric molecules (one consisting of the catalytic core of the chicken bisphosphatase domain and the rat COOH-terminal 25 amino acids, and the other consisting of most of the intact chicken enzyme and the rat COOH-terminal 25 amino acids) showed the same kinetic properties as the rat enzyme. Furthermore, substitution of the residues Pro456Pro457Ala458 of the chicken enzyme with GluAlaGlu, the corresponding sequence in the rat liver enzyme, yields a chicken enzyme that behaves like the rat enzyme. These results demonstrate that the different bisphosphatase activities of the chicken and rat liver bifunctional enzymes can be attributed to the differences in their COOH-terminal amino acid sequences, particularly the three residues.

Amino Acid Sequence↗

PubMed2000

Neurotensin receptor-1 mRNA analysis in normal pancreas and pancreatic disease.

By autoradiography, neurotensin (NT) binding is specifically detectable in pancreatic cancer, but not in the normal pancreas, chronic pancreatitis (CP), or other pancreatic disorders. In the present study, we investigated whether this is due to NT receptor-1 (NTR-1) mRNA up-regulation and whether NTR-1 mRNA could also be used as a specific diagnostic marker and treatment target in pancreatic cancer. Fifteen normal pancreas tissue samples, 20 CP samples, and 30 pancreatic cancer samples were studied. Expression and localization of NTR-1 mRNA was investigated by Northern blot analysis and in situ hybridization. Furthermore, consecutive tissue sections were analyzed for NTR-1 mRNA expression and NT binding. By Northern blot analysis, NTR-1 mRNA expression was 4.4-fold (P < 0.01) and 3.0-fold (P < 0.01) higher in pancreatic cancer and CP tissue samples, respectively, compared with normal controls. There was no difference in NTR-1 mRNA levels between CP and cancer samples (P > 0.05). In pancreatic cancer, the NTR-1 mRNA levels were higher in advanced tumor stage (stages III and IV) than early tumor stage (stages I and II; P < 0.05), but no difference was found between well/moderately differentiated (grades 1 and 2) and poorly differentiated/undifferentiated cancers (grades 3 and 4; P > 0.05). By in situ hybridization, NTR-1 mRNA signals were weakly present in the cytoplasm of acinar and ductal cells of the normal pancreas. Moderate to intense NTR-1 mRNA signals were present in the cytoplasm of acinar cells dedifferentiating into tubular complexes and degenerating acinar cells of CP samples. In the cancer samples, NTR-1 mRNA was moderately to intensely expressed in the cytoplasm of cancer cells. When on consecutive tissue sections NTR-1 mRNA expression was compared with the presence of NTR-1, measured by receptor autoradiography, a correlation was found in carcinomas but not in CP samples, in which no receptors were detectable by autoradiography. The enhanced expression of NTR-1 mRNA in pancreatic cancer cells further suggests that neuroendocrine hormones might modulate pancreas cancer cell behavior. However, its relatively high levels in CP excludes NTR-1 mRNA as a specific parameter for pancreatic cancer and for the differentiation of pancreatic cancer from CP.

Adult↗