Journal of Histochemistry and Cytochemistry Priciples for Free Access to Science
  Search:   
    >> Advanced Search

Guidelines | Subscriptions | About | exPRESS - Current - Archive | Business Information | Contact
Originally published as JHC exPRESS on May 1, 2006.
doi:10.1369/jhc.6A6966.2006
This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
jhc.6A6966.2006v1
54/9/1015    most recent
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Schulz, S.
Right arrow Articles by Schulz, S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Schulz, S.
Right arrow Articles by Schulz, S.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati  
What's this?
Journal of Histochemistry and Cytochemistry
Volume 54 (9): 1015-1020, 2006
Copyright ©The Histochemical Society, Inc.

Immunolocalization of Full-length NK1 Tachykinin Receptors in Human Tumors

Stefan Schulz, Ralf Stumm, Christoph Röcken, Christian Mawrin and Solveig Schulz

Departments of Pharmacology and Toxicology (StS,RS), Pathology (CR), Neuropathology (CM), and Obstetrics and Gynecology (SoS), Otto-von-Guericke-University, Magdeburg, Germany

Correspondence to: Stefan Schulz, Dept. of Pharmacology and Toxicology, Otto-von-Guericke-University, Leipziger Strasse 44, 39120 Magdeburg, Germany. E-mail: Stefan.Schulz{at}Medizin.Uni-Magdeburg.de


   Summary
Top
 Summary
Introduction
 Materials and Methods
 Results
 Discussion
 Literature Cited
 
Biological effects of substance P (SP) are mediated by the neurokinin-1 (NK1) receptor that exists as a full-length and as a carboxy-terminally truncated isoform in humans. Although NK1 receptor mRNA and binding sites have been detected in certain malignancies, little is known about the cellular and subcellular localization of NK1 receptor protein in human neoplastic tissues. We developed and characterized a novel anti-peptide antibody to the carboxy-terminal region of the human full-length NK1 receptor. Specificity of the antiserum was demonstrated by (1) detection of a broad band migrating at molecular mass 70,000–90,000 Da in Western blots of membranes from NK1-expressing tissues; (2) cell-surface staining of NK1-transfected cells; (3) translocation of NK1 receptor immunostaining after SP exposure; and (4) abolition of tissue immunostaining by preadsorption of the antibody with its immunizing peptide. Distribution of NK1 receptors was investigated in 72 formalin-fixed, paraffin-embedded human tumors showing that NK1 receptors were frequently expressed in glioblastomas and breast and pancreatic carcinomas. Immunoreactive NK1 receptors were clearly confined to the plasma membrane and uniformly present on nearly all tumor cells. Development of this novel NK1 receptor antibody allows the efficient localization of NK1 receptor protein in human formalin-fixed, paraffin-embedded tissues. NK1 receptor visualization with this simple and rapid immunohistochemical method will facilitate identification of tumors with a sufficient receptor overexpression for diagnostic or therapeutic intervention using SP analogs. (J Histochem Cytochem 54:1015–1020, 2006)

Key Words: substance P • tachykinin • NK1 receptor • neoplasm • antibody • immunocytochemistry • Western blot


   Introduction
Top
 Summary
 Introduction
Materials and Methods
 Results
 Discussion
 Literature Cited
 
SUBSTANCE P (SP) is an undecapeptide belonging to the tachykinin family of peptides. SP is widely distributed in both central and peripheral nervous systems, where it plays a well-established role in neurotransmission, vasodilatation, and motor responses (Maggi et al. 1993Go). SP and neurokinin A (NKA) are derived from the preprotachykinin A gene, whereas neurokinin B (NKB) is derived from the preprotachykinin B gene. Biological action of tachykinin peptides is mediated by a family of three G-protein-coupled receptors, namely, NK1, NK2, and NK3, which are preferentially activated by SP, NKA, and NKB, respectively (Maggi et al. 1993Go). Two NK1 receptor isoforms have been reported in humans, a full-length receptor (NK1-Fl) and a truncated receptor (NK1-Tr) that lacks 100 residues in its cytoplasmic tail (Fong et al. 1992Go).

NK1 receptor mRNA and binding sites have been detected in a relatively high percentage in glioblastomas and breast and pancreatic cancers (Johnson et al. 1991Go; Hennig et al. 1995Go; Winkler et al. 1995Go; Ehlers et al. 2000Go; Singh et al. 2000Go; Friess et al. 2003Go). Activation of NK1 receptors by SP triggers signaling pathways, e.g., extracellular signal-regulated protein kinases (ERK1/2), which are potentially relevant for tumor growth and progression (Luo et al. 1996Go; Fukuhara et al. 1998Go; Palma et al. 1999bGo; Palma and Maggi 2000Go; Koon et al. 2004Go). Conversely, administration of NK1 receptor antagonists has been reported to inhibit tumor cell growth in vitro and in vivo (Palma et al. 1999aGo,2000Go; Munoz et al. 2004Go,2005Go).

Although expression of NK1 receptors in human tumors has been well documented, the exact cellular and subcellular sites of NK1 receptor in human neoplastic tissues still need to be fully elucidated. Expression of NK1 receptors has previously been detected using binding autoradiography or reverse transcription-polymerase chain reaction (RT-PCR) (Hennig et al. 1995Go; Ehlers et al. 2000Go; Singh et al. 2000Go). However, anatomical resolution of autoradiographic receptor binding is limited, and RT-PCR does not discriminate between receptor transcripts originating from individual target cells.

In the present study we have generated and characterized antibodies directed to the carboxy-terminal tail of the NK1-Fl receptor. We have also developed an immunohistochemical (IHC) protocol that allows efficient detection of this receptor in formalin-fixed, paraffin-embedded human tissues. Generation of this novel antibody enabled us to determine the cellular distribution of NK1 receptor proteins in a variety of human tumors.


   Materials and Methods
Top
 Summary
 Introduction
 Materials and Methods
Results
 Discussion
 Literature Cited
 
Patients, Tumors, and Tissue Preparation
Seventy two tumor specimens were retrieved from the archives of the Department of Pathology. All tissue specimens had been fixed in formalin and embedded in paraffin. The following tumors were investigated: colorectal adenocarcinoma (n=5), ductal pancreatic adenocarcinoma (n=5), ductal invasive breast carcinoma (n=5), ovarian carcinoma (n=10), prostate cancer (n=4), thyroid carcinoma (n=6), carcinoid (n=15), pancreatic insulinoma (n=8), growth-hormone-producing pituitary adenoma (n=4), pheochromocytoma (n=2), glioblastoma (n=4), and meningioma (n=4). In addition, several fresh tumor specimens were immediately frozen in liquid N2 and stored at –70C until Western blot analysis. The following tumors were investigated: breast carcinoma (n=4) and ovarian carcinoma (n=4).

Generation and Purification of Antipeptide Antibodies
Polyclonal antisera were generated against the carboxy-terminal tail of the NK1 receptor. Identity of the peptide was SSRSDSKTMTESFSFSSNVLS, which corresponds to amino acids 387–407 of the NK1-Fl receptor. The peptide was synthesized, purified, and coupled to keyhole limpet hemocyanin as described (Schulz et al. 2000Go). The conjugate was mixed 1:1 with Freund's adjuvant and injected into groups of three rabbits {9040–9042} for NK1 antisera production. Animals were injected at 4-week intervals, and serum was obtained 2 weeks after immunizations beginning with the second injection. Specificity of the antisera was initially tested using immunodot-blot analysis as described (Schulz et al. 2000Go). For subsequent analysis, antibodies were affinity purified against their immunizing peptide using the Sulfo-Link coupling gel according to manufacturer's instructions (Pierce; Rockford, IL).

Immunocytochemistry
Human embryonic kidney 293 (HEK-293) cells were stably transfected with the human NK1 receptor. Cells were grown on coverslips overnight and either not exposed or exposed to 1 µM SP (Bachem; Weil am Rhein, Germany). Cells were then fixed and incubated with 1 µg/ml anti-NK1 {9042} antibodies followed by cyanin 3.18-conjugated secondary antibodies (Amersham; Braunschweig, Germany). Specimens were mounted and examined using a Leica TCS-NT laser scanning confocal microscope (Leica; Wetzlar, Germany) as described (Pfeiffer et al. 2001Go).

Western Blot Analysis
Membranes were prepared from stably transfected HEK-293 cells as well as from fresh tumor specimens. Cells and tissues were lysed in homogenization buffer (5 mM EDTA, 3 mM EGTA, 250 mM sucrose, 10 mM Tris-HCl, pH 7.6, containing 1 mM phenylmethylsulfonylfluoride, 1 µM pepstatin A, 10 µg/ml leupeptin, and 2 µg/ml aprotinin), and membranes were pelleted at 20,000 x g for 30 min at 4C. Membranes were then dissolved in lysis buffer (150 mM NaCl, 5 mM EDTA, 3 mM EGTA, 20 mM Hepes, pH 7.4, containing 4 mg/ml dodecyl-ß-maltoside and proteinase inhibitors as above) and incubated with 150 µl wheat germ lectin agarose beads (Amersham) for 90 min at 4C. Beads were washed five times in lysis buffer, and adsorbed glycoproteins were eluted with SDS sample buffer for 20 min at 60C. Samples were then subjected to 8% SDS polyacrylamide gel electrophoresis and immunoblotted onto nitrocellulose. Blots were incubated with 1 µg/ml anti-NK1 {9042} antibodies followed by peroxidase-conjugated secondary antibodies and enhanced chemiluminescence detection (Amersham). For adsorption controls, antibody was preincubated with 10 µg/ml of its cognate peptide for 2 hr at room temperature.

Immunohistochemistry
Seven-µm paraffin sections were cut and floated onto positively charged slides and IHC stained as described (Schulz et al. 2000Go,2004Go,2005Go; Mundschenk et al. 2003Go). Briefly, sections were dewaxed, microwaved in 10 mM citric acid (pH 6.0) for 20 min at 600 W, and subsequently incubated with anti-NK1 {9042} antibodies in concentrations ranging from 0.5 to 2 µg/ml overnight at 4C. Staining of primary antibody was detected using biotinylated goat anti-rabbit IgG followed by incubation with avidin-biotinylated peroxidase solution. Tissue was then rinsed and stained with 3,3'-diaminobenzidine–glucose oxidase for 15 min. Cell nuclei were lightly counterstained with hematoxylin. For IHC controls, primary antibody was omitted, replaced by preimmune sera, or adsorbed with several concentrations ranging from 1 to 10 µg/ml of homologous or heterologous peptides for 2 hr at room temperature. A tumor known to stain positively was included in each batch of staining as positive control.

Assessment of Staining Patterns
All slides were evaluated by two independent investigators. The presence or absence of staining and the depth of color were noted, as well as the number of cells showing a positive reaction and whether or not the staining was localized to the plasma membrane. Tumors were only categorized as positive when they exhibited a moderate to strong plasma membrane and/or cytoplasmic staining in the majority of tumor cells, which was easily visible with a low-power objective.


   Results
Top
 Summary
 Introduction
 Materials and Methods
 Results
Discussion
 Literature Cited
 
Characterization of NK1 Receptor Antibodies
Specificity of the antisera was monitored using Western blot analysis. When membrane preparations from stably transfected cells were electrophoretically separated and blotted onto nitrocellulose, the anti-NK1 {9042} antiserum detected a broad band migrating at molecular mass 70,000 to 90,000 Da only in cells transfected with its cognate receptor but not in cells transfected with an empty vector (Figure 1 ). Antisera were further characterized using immunofluorescent staining of transfected cells. When HEK-293 cells stably expressing NK1 were stained with the anti-NK1 antibody {9042}, prominent immunofluorescence localized at the level of the plasma membrane was detected (Figure 2A ). After incubation with SP, NK1 immunoreactivity (ir) was translocated from the plasma membrane into the cytosol indicating that the NK1 receptor was rapidly endocytosed in an agonist-dependent manner (Figure 2B). Next, the NK1 receptor antisera were tested for possible cross-reactivity with other proteins present in human tissues. When membrane preparations from human breast or ovarian carcinomas were electrophoretically separated and blotted onto nitrocellulose, the anti-NK1 antibody {9042} detected a broad band migrating at molecular mass 70,000 to 90,000 Da (Figures 3A and 3B). A few cases were observed in which this broad receptor band consisted of several narrower bands, suggesting that the NK1 receptor may exist in differently glycosylated forms (Figure 3B). All ir bands were completely abolished by preadsorption of the antibody with 10 µg/ml of its immunizing peptide (Figures 3A and 3B).


Figure 1
View larger version (10K):
[in this window]
[in a new window]
  		Figure 1

Western blot analysis of the specificity of anti-NK1 antibodies. Membrane preparations from HEK-293 cells transfected with NK1 or empty vector (MOCK) were separated on 8% SDS-polyacrylamide gels and blotted onto nitrocellulose membranes. Membranes were then incubated with affinity-purified anti-NK1 {9042} antibodies at a concentration of 1 µg/ml. Blots were developed using enhanced chemiluminescence. Two additional experiments gave similar results. MOCK, empty vector; ordinate, migration of protein molecular mass markers (molecular mass x 10–3).

 

Figure 2
View larger version (28K):
[in this window]
[in a new window]
  		Figure 2

Characterization of anti-NK1 antibodies by immunofluorescent staining of transfected cells. (A,B) HEK-293 cells stably transfected to express NK1 were either not exposed (A) or exposed (B) to 1 µM SP for 30 min, subsequently fixed, and immunofluorescently stained with anti-NK1 {9042} antibody. Note that in untreated cells prominent immunofluorescence was localized at the level of the plasma membrane and that exposure to SP induced a rapid translocation of NK1 receptors from the plasma membrane into the cytosol. Representative results from one of three independent experiments are shown. SP, substance P. Bar = 20 µm.

 

Figure 3
View larger version (31K):
[in this window]
[in a new window]
  		Figure 3

Western blot analysis of the specificity of anti-NK1 antibodies in human tumors. (A) Membrane preparations from a breast carcinoma were separated on 8% SDS-polyacrylamide gels, blotted onto nitrocellulose, and incubated with 1 µg/ml anti-NK1 antibody {9042} in the absence (–) or presence (+) of 10 µg/ml peptide antigen. (B) Membrane preparations from an ovarian carcinoma were separated on 8% SDS-polyacrylamide gels, blotted onto nitrocellulose, and incubated with 1 µg/ml anti-NK1 antibody {9042} in the absence (–) or presence (+) of 10 µg/ml peptide antigen. Blots were developed using enhanced chemiluminescence. Representative results from one of three independent experiments are shown. Ordinate, migration of protein molecular mass markers (molecular mass x 10–3).

 
NK1 Receptor IHC Staining in Neoplastic Human Tissues
The anti-NK1 antibodies were then subjected to IHC staining of human tissues. Initial experiments showed that heat-induced epitope retrieval is required for efficient IHC staining of paraffin-embedded tissues (not shown). All three anti-NK1 antisera yielded essentially identical IHC staining patterns with prominent ir predominantly localized to the plasma membrane of the tumor cells, although with different staining intensity (Figure 4 ). Immunostaining for each antiserum was completely abolished by preadsorption with 10 µg/ml of the immunizing peptide (Figure 4B). The anti-NK1 antibody {9042} produced the most prominent immunostaining and was therefore used throughout the study. Prevalence of NK1 receptors in human neoplasms is summarized in Table 1 . Immunoreactive NK1 receptors were frequently detected in pancreatic adenocarcinomas (80%), breast carcinomas (75%), and glioblastomas (75%). In most of these tumors, ir NK1 receptors were homogeneously present on nearly all tumor cells (Figures 4A, 4C, 4F). However, a few tumors were observed with heterogeneous NK1 expression, i.e., tumor cells with strong to moderate NK1 receptor staining were seen next to tumor cells lacking ir NK1 receptors (Figures 4D and 4E). Immunoreactive NK1 receptors were also found in 4/10 ovarian carcinomas (40%), 2/6 thyroid carcinomas (30%), and 1/4 growth hormone-producing pituitary adenomas (25%). In contrast, ir NK1 receptors were not detected in neuroendocrine tumors including carcinoid or insulinoma. NK1 receptors were also not observed in meningiomas, pheochromocytomas, or prostate and colorectal cancer.


Figure 4
View larger version (93K):
[in this window]
[in a new window]
  		Figure 4

NK1 immunohistochemical (IHC) staining in human neoplastic tissues. NK1 IHC staining in pancreatic carcinoma (A,B,D,E), glioblastoma (C), and ovarian carcinoma (F). Sections were dewaxed, microwaved in citric acid, and incubated with affinity-purified anti-NK1 antibody {9042} at a concentration of 1 µg/ml. Sections were then sequentially treated with biotinylated anti-rabbit IgG and AB peroxidase solution. Sections were then developed with 3,3'-diaminobenzidine as chromogen (brown), and cell nuclei were lightly counterstained with hematoxylin (blue). Note that NK1 receptor immunoreactivity was predominantly localized homogeneously to the plasma membrane of nearly all tumor cells (A,C,F). In contrast, a few tumors were observed with heterogeneous NK1 expression, i.e., tumor cells with strong to moderate NK1 receptor staining were seen next to tumor cells lacking immunoreactive NK1 receptors (D,F). For adsorption controls, primary antibody was incubated with 10 µg/ml of the peptide used for immunizations (B). Representative results from one of three independent experiments are shown. +Peptide, peptide adsorption control. Bars: A,B,C,E,F = 50 µm; D = 100 µm.

 

View this table:
[in this window]
[in a new window]
  		Table 1

Prevalence of NK1 receptors in human tumors

 

   Discussion
Top
 Summary
 Introduction
 Materials and Methods
 Results
 Discussion
Literature Cited
 
It is well established that NK1 receptors are overexpressed in certain malignancies including glioblastomas and breast and pancreatic carcinomas; however, little is known about their cellular and subcellular localization in human neoplastic tissues. We therefore generated antibodies that exert selective specificity for the human NK1-Fl receptor. We show that the cytoplasmic tail of this receptor can serve as an epitope for the generation of antisera that effectively stain formalin-fixed, paraffin-embedded human tissues. Several lines of evidence indicate that this antibody specifically detects its targeted tachykinin receptor and does not crossreact. First, in Western blots of membranes from transfected cells, the anti-NK1 antibody detected a band migrating at molecular mass 70,000 to 90,000 Da only in NK1-transfected cells but not in cells transfected with an empty vector. Second, the anti-NK1 antibody revealed prominent cell surface staining of NK1-transfected cells. This immunostaining translocated from the cell surface into the cytosol after agonist exposure indicating rapid endocytosis of the NK1 receptor. Third, in Western blots of membranes from receptor-expressing tumors, the anti-NK1 antibody detected a broad band migrating at molecular mass 70,000 to 90,000 Da, which corresponds to a glycosylated form of the receptor. Fourth, tissue immunostaining of the anti-NK1 antiserum was completely abolished by preadsorption with homologous but not heterologous peptides. Finally, it should be noted that three of three NK1 antisera yielded similar results.

Availability of NK1 receptor antibodies will facilitate further basic morphological investigation of NK1 expression in human normal and neoplastic tissues. The IHC NK1 receptor evaluation offers several major advantages. This method can analyze NK1 receptors in routinely processed archival paraffin-embedded material of any diagnostic pathology center. It requires only an immunopathological laboratory to perform the test, which can be carried out without costly and time-consuming receptor autoradiography (Hennig et al. 1995Go). IHC evaluation of the complete NK1 receptor status of a given tumor specimen can be accomplished in <24 hr. Although one could expect the IHC NK1 receptor determination to be less sensitive than receptor autoradiography with 125I-labeled SP, sensitivity of the anti-NK1 {9042} antibody generated and characterized in this study was sufficiently high to detect this receptor in human tumors known to express NK1 receptors in a high percentage, e.g., glioblastomas and breast and pancreatic carcinomas (Hennig et al. 1995Go; Ehlers et al. 2000Go; Singh et al. 2000Go; Friess et al. 2003Go). In addition, the IHC NK1 receptor determination provided a better histological quality and cellular resolution compared with receptor autoradiography. Thus, previously unappreciated cellular localizations of NK1 receptors were uncovered, i.e., heterogeneous expression of NK1 receptors in a subpopulation of pancreatic carcinomas.

SP can affect the growth of human tumor cells in vivo and in vitro. Whereas growth-promoting activities have been reported for SP, growth-inhibiting properties have been found for NK1 antagonists in various tumor models (Luo et al. 1996Go; Fukuhara et al. 1998Go; Palma et al. 1999aGo,bGo,2000Go; Palma and Maggi 2000Go; Koon et al. 2004Go; Munoz et al. 2004Go,2005Go). It is therefore very tempting to suggest the use of NK1 antagonists for treatment of a subset of human malignancies. The present findings also suggest that NK1 receptors could be promising molecular targets for tumor imaging and targeted radiotherapy using radiolabeled SP analogs (Breeman et al. 1996Go; Reubi et al. 2005Go).

It is believed that the human NK1 gene could generate NK1-Fl and NK1-Tr transcripts (Fong et al. 1992Go). NK1-Fl and NK1-Tr have identical ligand-binding domains but differ in length of their cytoplasmic tails. Specifically, the cytoplasmic tail of NK1-Tr lacks 100 residues, a region that functions as a substrate for phosphorylation by G-protein-coupled receptor kinases in NK1-Fl. Consequently, NK1-Tr shows a reduced capacity to undergo SP-induced internalization and desensitization (Fong et al. 1992Go). Interestingly, overexpression of NK1-Tr has recently been shown to promote malignant transformation of breast cells (Patel et al. 2005Go). Given that the antibody raised and characterized here is directed to the end of the cytoplasmic tail of the NK1-Fl receptor, it was not possible to detect NK1-Tr in the present study.

In conclusion, we have generated and extensively characterized anti-NK1 antibodies. Development of this novel antibody enabled us to visualize NK1-Fl receptors in human formalin-fixed, paraffin-embedded tissues. It is now possible to determine the exact cellular and subcellular sites of NK1 receptor protein in normal human and neoplastic tissues. Rapid immunocytochemical NK1 receptor visualization may also be helpful to identify those tumors with sufficient receptor overexpression for diagnostic or therapeutic intervention.


   Acknowledgments
 
We thank Beate Peter and Dana Mayer for skillful technical assistance.


   Footnotes
 
Received for publication March 12, 2006; accepted April 19, 2006


   Literature Cited
Top
 Summary
 Introduction
 Materials and Methods
 Results
 Discussion
 Literature Cited
 

Breeman WA, VanHagen MP, Visser-Wisselaar HA, van der Pluijm ME, Koper JW, Setyono-Han B, Bakker WH, et al. (1996) In vitro and in vivo studies of substance P receptor expression in rats with the new analog [indium-111-DTPA-Arg1]substance P. J Nucl Med 37:108–117[Abstract/Free Full Text]

Ehlers RA, Kim S, Zhang Y, Ethridge RT, Murrilo C, Hellmich MR, Evans DB, et al. (2000) Gut peptide receptor expression in human pancreatic cancers. Ann Surg 231:838–848[CrossRef][Medline]

Fong TM, Anderson SA, Yu H, Huang RR, Strader CD (1992) Differential activation of intracellular effector by two isoforms of human neurokinin-1 receptor. Mol Pharmacol 41:24–30[Abstract]

Friess H, Zhu Z, Liard V, Shi X, Shrikhande SV, Wang L, Lieb K, et al. (2003) Neurokinin-1 receptor expression and its potential effects on tumor growth in human pancreatic cancer. Lab Invest 83:731–742[Medline]

Fukuhara S, Shimizu M, Matsushima H, Mukai H, Munekata E (1998) Signaling pathways via NK1 receptors and their desensitization in an AR42J cell line. Peptides 19:1349–1357[CrossRef][Medline]

Hennig IM, Laissue JA, Horisberger U, Reubi JC (1995) Substance-P receptors in human primary neoplasms: tumoral and vascular localization. Int J Cancer 61:786–792[Medline]

Johnson CL, Johnson CG, Stauderman KA, Buck SH (1991) Characterization of substance P receptors in human astrocytoma cells. Ann NY Acad Sci 632:410–412[Medline]

Koon HW, Zhao D, Na X, Moyer MP, Pothoulakis C (2004) Metalloproteinases and transforming growth factor-alpha mediate substance P-induced mitogen-activated protein kinase activation and proliferation in human colonocytes. J Biol Chem 279:45519–45527[Abstract/Free Full Text]

Luo W, Sharif TR, Sharif M (1996) Substance P-induced mitogenesis in human astrocytoma cells correlates with activation of the mitogen-activated protein kinase signaling pathway. Cancer Res 56:4983–4991[Abstract/Free Full Text]

Maggi CA, Patacchini R, Rovero P, Giachetti A (1993) Tachykinin receptors and tachykinin receptor antagonists. J Auton Pharmacol 13:23–93[Medline]

Mundschenk J, Unger N, Schulz S, Hollt V, Steinke R, Lehnert H (2003) Somatostatin receptor subtypes in human pheochromocytoma: subcellular expression pattern and functional relevance for octreotide scintigraphy. J Clin Endocrinol Metab 88:5150–5157[Abstract/Free Full Text]

Munoz M, Perez A, Rosso M, Zamarriego C, Rosso R (2004) Antitumoral action of the neurokinin-1 receptor antagonist L-733 060 on human melanoma cell lines. Melanoma Res 14:183–188[CrossRef][Medline]

Munoz M, Rosso M, Perez A, Covenas R, Rosso R, Zamarriego C, Piruat JI (2005) The NK1 receptor is involved in the antitumoural action of L-733,060 and in the mitogenic action of substance P on neuroblastoma and glioma cell lines. Neuropeptides 39:427–432[CrossRef][Medline]

Palma C, Bigioni M, Irrissuto C, Nardelli F, Maggi CA, Manzini S (2000) Anti-tumour activity of tachykinin NK1 receptor antagonists on human glioma U373 MG xenograft. Br J Cancer 82:480–487[CrossRef][Medline]

Palma C, Maggi CA (2000) The role of tachykinins via NK1 receptors in progression of human gliomas. Life Sci 67:985–1001[CrossRef][Medline]

Palma C, Nardelli F, Manzini S (1999a) Correlation between binding characteristics and functional antagonism in human glioma cells by tachykinin NK1 receptor antagonists. Eur J Pharmacol 374:435–443[CrossRef][Medline]

Palma C, Nardelli F, Manzini S, Maggi CA (1999b) Substance P activates responses correlated with tumour growth in human glioma cell lines bearing tachykinin NK1 receptors. Br J Cancer 79:236–243[CrossRef][Medline]

Patel HJ, Ramkissoon SH, Patel PS, Rameshwar P (2005) Transformation of breast cells by truncated neurokinin-1 receptor is secondary to activation by preprotachykinin-A peptides. Proc Natl Acad Sci USA 102:17436–17441[Abstract/Free Full Text]

Pfeiffer M, Koch T, Schroder H, Klutzny M, Kirscht S, Kreienkamp HJ, Hollt V, et al. (2001) Homo- and heterodimerization of somatostatin receptor subtypes. Inactivation of sst(3) receptor function by heterodimerization with sst(2A). J Biol Chem 276:14027–14036[Abstract/Free Full Text]

Reubi JC, Macke HR, Krenning EP (2005) Candidates for peptide receptor radiotherapy today and in the future. J Nucl Med 46(suppl 1):67–75S[Abstract/Free Full Text]

Schulz S, Pauli SU, Handel M, Dietzmann K, Firsching R, Hollt V (2000) Immunohistochemical determination of five somatostatin receptors in meningioma reveals frequent overexpression of somatostatin receptor subtype sst2A. Clin Cancer Res 6:1865–1874[Abstract/Free Full Text]

Schulz S, Rocken C, Mawrin C (2005) Immunohistochemical localization of CCK1 cholecystokinin receptors in normal and neoplastic human tissues. J Clin Endocrinol Metab 90:6149–6155[Abstract/Free Full Text]

Schulz S, Rocken C, Mawrin C, Weise W, Hollt V (2004) Immunocytochemical identification of VPAC1, VPAC2, and PAC1 receptors in normal and neoplastic human tissues with subtype-specific antibodies. Clin Cancer Res 10:8235–8242[Abstract/Free Full Text]

Singh D, Joshi DD, Hameed M, Qian J, Gascon P, Maloof PB, Mosenthal A, et al. (2000) Increased expression of preprotachykinin-I and neurokinin receptors in human breast cancer cells: implications for bone marrow metastasis. Proc Natl Acad Sci USA 97:388–393[Abstract/Free Full Text]

Winkler A, Papsdorf G, Odarjuk J, Siems WE, Fickel J, Melzig MF (1995) Expression and characterization of the substance P (NK1) receptor in the rat pituitary and AtT20 mouse pituitary tumor cells. Eur J Pharmacol 291:51–55[CrossRef][Medline]


Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati    What's this?


This article has been cited by other articles:


Home page
 IOVSHome page
M. Munoz, M. Rosso, R. Covenas, I. Montero, M. A. Gonzalez-Moles, and M. J. Robles
Neurokinin-1 Receptors Located in Human Retinoblastoma Cell Lines: Antitumor Action of Its Antagonist, L-732,138
Invest. Ophthalmol. Vis. Sci., June 1, 2007; 48(6): 2775 - 2781.
[Abstract] [Full Text] [PDF]

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
jhc.6A6966.2006v1
54/9/1015    most recent
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Schulz, S.
Right arrow Articles by Schulz, S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Schulz, S.
Right arrow Articles by Schulz, S.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati  
What's this?


Guidelines | Subscriptions | About | exPRESS - Current - Archive | Business Information | Contact