Gene Summary

Gene:TACR1; tachykinin receptor 1
Aliases: SPR, NK1R, NKIR, TAC1R
Summary:This gene belongs to a gene family of tachykinin receptors. These tachykinin receptors are characterized by interactions with G proteins and contain seven hydrophobic transmembrane regions. This gene encodes the receptor for the tachykinin substance P, also referred to as neurokinin 1. The encoded protein is also involved in the mediation of phosphatidylinositol metabolism of substance P. [provided by RefSeq, Sep 2008]
Databases:OMIM, VEGA, HGNC, Ensembl, GeneCard, Gene
Protein:substance-P receptor
Source:NCBIAccessed: 06 August, 2015


What does this gene/protein do?
Show (43)
Pathways:What pathways are this gene/protein implicaed in?
Show (2)

Cancer Overview

Research Indicators

Publications Per Year (1990-2015)
Graph generated 06 August 2015 using data from PubMed using criteria.

Literature Analysis

Mouse over the terms for more detail; many indicate links which you can click for dedicated pages about the topic.

  • Tachykinins
  • Substance P
  • Receptors, Neurokinin-1
  • Tryptophan
  • Dose-Response Relationship, Drug
  • Cell Division
  • Risk Factors
  • Receptors, Neurokinin-2
  • Cell Proliferation
  • Colorectal Cancer
  • Cell Survival
  • GTP-Binding Proteins
  • Neoplasm Metastasis
  • Bone Marrow Cells
  • Neurokinin A
  • Triazoles
  • TGFB1
  • Xenopus laevis
  • Neoplastic Cell Transformation
  • Morpholines
  • Chromosome 2
  • Neoplasm Proteins
  • Neoplasm Invasiveness
  • Cancer Gene Expression Regulation
  • Enzyme Inhibitors
  • Messenger RNA
  • Mice, Inbred BALB C
  • Zinc Fingers
  • Childhood Cancer
  • Cancer RNA
  • Breast Cancer
  • Brain, Astrocytoma, Childhood
  • Apoptosis
  • Tumor Markers
  • Signal Transduction
  • Transfection
  • Neurokinin-1 Receptor Antagonists
  • Up-Regulation
  • Gene Expression
  • Protein Precursors
Tag cloud generated 06 August, 2015 using data from PubMed, MeSH and CancerIndex

Specific Cancers (3)

Data table showing topics related to specific cancers and associated disorders. Scope includes mutations and abnormal protein expression.

Note: list is not exhaustive. Number of papers are based on searches of PubMed (click on topic title for arbitrary criteria used).

Latest Publications: TACR1 (cancer-related)

Dong J, Feng F, Xu G, et al.
Elevated SP/NK-1R in esophageal carcinoma promotes esophageal carcinoma cell proliferation and migration.
Gene. 2015; 560(2):205-10 [PubMed] Related Publications
BACKGROUND: Esophageal squamous cell carcinoma (ESCC) remains one of the most lethal malignant tumors, and currently there is no effective ways to manage the late stage disease. Therefore clarifying the mechanisms underlying the development of ESCC is of great importance to develop novel therapeutic agents. The present study focuses on the interaction between neurotransmitter substance P (SP) together with its receptor NK-1R and ESCC progression.
METHODS: The distribution of SP positive nerve fibers and expression of NK-1R were detected in ESCC tissue using immunohistochemistry. The effects of SP stimulation and blocking on the growth and migration of ESCC cells were measured by in vitro and in vivo assay.
RESULTS: A higher density of SP positive nerve fibers and elevated NK-1R expression on ESCC cells were observed. More importantly, the SP positive fiber density was correlated with tumor size and lymph node metastasis. SP promoted ESCC cell proliferation and migration by modulation of intracellular calcium levels.
CONCLUSION: NK-1R activation by SP stimulation promotes growth and migration of ESCC cells.

Park PJ, Lee TR, Cho EG
Substance P stimulates endothelin 1 secretion via endothelin-converting enzyme 1 and promotes melanogenesis in human melanocytes.
J Invest Dermatol. 2015; 135(2):551-9 [PubMed] Related Publications
Substance P (SP) is a well-known neuropeptide implicated in the wound-healing process. The wound occasionally causes a pigmented scar. In the present study, we examined whether increased levels of SP affected melanogenesis. When human melanocytes were treated with SP, the melanin content increased and the pigmentation process accelerated in a dose-dependent manner. In addition to melanogenesis-related genes, the expression of neurokinin 1 receptor, endothelin 1 (EDN1), and EDN receptor type B (EDNRB) also increased at both the messenger RNA and protein levels. Interestingly, secreted EDN1 was observed in the melanocyte culture medium, and this phenomenon was significantly enhanced by SP treatment. Through knockdown experiments using small interfering RNAs (siRNAs), we confirmed that endothelin-converting enzyme 1 (ECE1), EDN1, and EDNRB were involved in SP-induced pigmentation and found that EDN1 secretion was affected by ECE1 and EDN1 siRNAs, but not by EDNRB siRNA. These findings indicate that ECE1 is essential for EDN1 secretion in melanocytes and that EDNRB functions downstream of secreted EDN1 to increase the cAMP levels and activate the melanogenesis-related phosphorylation cascade. This study provides in vitro evidence for a melanogenic function of SP in the skin and suggests that the SP-related signal is a potent target for regulating stress- or wound-induced pigmentation.

Muñoz M, González-Ortega A, Salinas-Martín MV, et al.
The neurokinin-1 receptor antagonist aprepitant is a promising candidate for the treatment of breast cancer.
Int J Oncol. 2014; 45(4):1658-72 [PubMed] Related Publications
The substance P (SP)/neurokinin (NK)-1 receptor system plays an important role in the development of cancer. No in-depth studies of the involvement of this system in breast cancer (BC) have been carried out, and the action exerted by the drug aprepitant on BC cells is currently unknown. We show the involvement of this system in human BC cell lines: i) these cells express mRNA for the NK-1 receptor; ii) they overexpress NK-1 receptors; iii) the NK-1 receptor is involved in their viability; iv) SP induces their proliferation; v) NK-1 receptor antagonists block SP-induced mitogen stimulation of these cells; vi) the specific antitumor action of such antagonists on these cells occurs through the NK-1 receptor; and vii) BC cell death is due to apoptosis. We also found NK-1 receptors and SP in all human BC samples studied. The NK-1 receptor may be a promising target in the treatment of BC and NK-1 receptor antagonists could be candidates as a new antitumor drug in the treatment of BC.

Zhou Y, Zuo D, Wang M, et al.
Effect of truncated neurokinin-1 receptor expression changes on the interaction between human breast cancer and bone marrow-derived mesenchymal stem cells.
Genes Cells. 2014; 19(9):676-91 [PubMed] Related Publications
Previous studies in breast cancer cell lines showed that truncated neurokinin receptor-1 (NK1R-Tr) was able to promote malignant transformation of breast cells, and NK1R-Tr may contribute to tumor progression and promote distant metastasis in human breast cancer. A co-culture model of breast cancer and bone marrow-derived human mesenchymal stem (HMSC-bm) cells showed that HMSC-bm inhibited the growth of breast cancer cells and entered the bone marrow at early stages. Down-regulation of NK1R-Tr may be a key factor in maintaining the quiescent phenotype of breast cancer cells among bone marrow stroma. Stromal-derived factor (SDF)-1α expression was negatively correlated with NK1R-Tr expression in breast cancer cells. Secretion of SDF-1α by HMSC-bm may maintain the quiescent phenotype of breast cancer cells among bone marrow stroma by down-regulating NK1R-Tr expression. Transforming growth factor (TGF)-β1 expression was positively associated with NK1R-Tr expression in breast cancer cells. In a co-culture system, MDA-MB-231-TGF-β1I (TGF-β genes were suppressed using specific shRNA) cells were able to attach to HMSC-bm quickly, indicating that TGF-β1 was also a key factor for maintaining the quiescent phenotype of breast cancer cells in bone marrow stroma. However, the detailed mechanism still remained unclear and could involve other molecules, in addition to NK1R-Tr.

Meng F, DeMorrow S, Venter J, et al.
Overexpression of membrane metalloendopeptidase inhibits substance P stimulation of cholangiocarcinoma growth.
Am J Physiol Gastrointest Liver Physiol. 2014; 306(9):G759-68 [PubMed] Free Access to Full Article Related Publications
Substance P (SP) promotes cholangiocyte growth during cholestasis by activating its receptor, NK1R. SP is a proteolytic product of tachykinin (Tac1) and is deactivated by membrane metalloendopeptidase (MME). This study aimed to evaluate the functional role of SP in the regulation of cholangiocarcinoma (CCA) growth. NK1R, Tac1, and MME expression and SP secretion were assessed in human CCA cells and nonmalignant cholangiocytes. The proliferative effects of SP (in the absence/presence of the NK1R inhibitor, L-733,060) and of L-733,060 were evaluated. In vivo, the effect of L-733,060 treatment or MME overexpression on tumor growth was evaluated by using a xenograft model of CCA in nu/nu nude mice. The expression of Tac1, MME, NK1R, PCNA, CK-19, and VEGF-A was analyzed in the resulting tumors. Human CCA cell lines had increased expression of Tac1 and NK1R, along with reduced levels of MME compared with nonmalignant cholangiocytes, resulting in a subsequent increase in SP secretion. SP treatment increased CCA cell proliferation in vitro, which was blocked by L-733,060. Treatment with L-733,060 alone inhibited CCA proliferation in vitro and in vivo. Xenograft tumors derived from MME-overexpressed human Mz-ChA-1 CCA cells had a slower growth rate than those derived from control cells. Expression of PCNA, CK-19, and VEGF-A decreased, whereas MME expression increased in the xenograft tumors treated with L-733,060 or MME-overexpressed xenograft tumors compared with controls. The study suggests that SP secreted by CCA promotes CCA growth via autocrine pathway. Blockade of SP secretion and NK1R signaling may be important for the management of CCA.

Qiu J, Chen S, Su L, et al.
Cellular nucleic acid binding protein suppresses tumor cell metastasis and induces tumor cell death by downregulating heterogeneous ribonucleoprotein K in fibrosarcoma cells.
Biochim Biophys Acta. 2014; 1840(7):2244-52 [PubMed] Related Publications
BACKGROUND: Cellular nucleic acid binding protein (CNBP) has been implicated in vertebrate craniofacial development and in myotonic dystrophy type 2 (DM2) and sporadic inclusion body myositis (sIBM) human diseases by controlling cell proliferation and survival to mediate neural crest expansion. CNBP has been found to bind single-stranded nucleic acid and promote rearrangements of nucleic acid secondary structure in an ATP-independent manner, acting as a nucleic acid chaperone.
METHODS: A variety of methods were used, including cell viability assays, wound-scratch assays, chemotaxis assays, invasion assays, circular dichroic (CD) spectroscopy, NMR spectroscopy, chromatin immunoprecipitation, expression and purification of recombinant human CNBP, electrophoretic mobility shift assay (EMSA), surface plasmon resonance (SPR), fluorescence resonance energy transfer (FRET) analyses, luciferase reporter assay, Western blotting, and isothermal titration calorimetry (ITC).
RESULTS: Up-regulation of CNBP induced human fibrosarcoma cell death and suppressed fibrosarcoma cell motility and invasiveness. It was found that CNBP transcriptionally down-regulated the expression of heterogeneous ribonucleoprotein K (hnRNP K) through its conversion of a G-rich sequence into G-quadruplex in the promoter of hnRNP K. G-quadruplex stabilizing ligand tetra-(N-methyl-4-pyridyl) porphyrin (TMPyP4) could interact with and stabilize the G-quadruplex, resulting in downregulation of hnRNP K transcription.
CONCLUSIONS: CNBP overexpression caused increase of cell death and suppression of cell metastasis through its induction of G-quadruplex formation in the promoter of hnRNP K resulting in hnRNP K down-regulation.
GENERAL SIGNIFICANCE: The present result provided a new solution for controlling hnRNP K expression, which should shed light on new anticancer drug design and development.

González-Ortega A, Sánchez-Vaderrábanos E, Ramiro-Fuentes S, et al.
Uveal melanoma expresses NK-1 receptors and cyclosporin A induces apoptosis in human melanoma cell lines overexpressing the NK-1 receptor.
Peptides. 2014; 55:1-12 [PubMed] Related Publications
Substance P and neurokinin-1 (NK-1) receptor antagonists respectively induce proliferation and growth inhibition in human melanoma cell lines. The presence of NK-1 receptors in human melanoma cell lines and samples has been reported, but the presence of NK-1 receptors has not been demonstrated in uveal melanomas. It is known that melanoma express the tachykinin 1 receptor (TAC1R) gene. This gene is overexpressed in several human cancer cell lines, but such overexpression is currently unknown in human malignant melanoma cell lines (COLO 858, MEL HO, COLO 679). In this study, we attempt to demonstrate the overexpression of the TAC1R gene in such cells. We performed an in vitro study by real-time quantitative RT-PCR for TAC1R and found that the NK-1 receptor was overexpressed in the three human melanoma cell lines studied. Using a knockdown method, we demonstrate that the NK-1 receptor is involved in the viability of the COLO 858 melanoma cell line. Immunohistochemistry was also used to demonstrate NK-1 receptors in uveal melanoma samples. We observed that NK-1 receptors were present in the 21/21 uveal melanomas. In addition, cyclosporin A inhibited the growth of the three melanoma cell lines studied in a dose-dependent manner, and after the administration of this immunosuppresive drug apoptosis was observed. This indicates at least that the antitumor action of cyclosporin A is mediated by the NK-1 receptor. Our findings suggest that the NK-1 receptor could be a promising target in the treatment of human melanomas.

Sumarheni S, Hong SS, Josserand V, et al.
Human full-length coagulation factor X and a GLA domain-derived 40-mer polypeptide bind to different regions of the adenovirus serotype 5 hexon capsomer.
Hum Gene Ther. 2014; 25(4):339-49 [PubMed] Free Access to Full Article Related Publications
The interaction of human adenovirus (HAdV)-C5 and many other adenoviruses with blood coagulation factors (e.g., human factor X, FX) involves the binding of their GLA domain to the hexon capsomers, resulting in high levels of hepatotropism and potential hepatotoxicity. In this study, we tested the possibility of preventing these undesirable effects by using a GLA-mimicking peptide as a competitor. An FX GLA domain-derived, 40-mer polypeptide carrying 12 carboxyglutamate residues was synthesized (GLA(mim)). Surface plasmon resistance (SPR) analysis showed that GLA(mim) reacted with free and capsid-embedded hexon with a nanomolar affinity. Unexpectedly, GLA(mim) failed to compete with FX for hexon binding, and instead significantly increased the formation of FX-hexon or FX-adenovirion complexes. This observation was confirmed by in vitro cell transduction experiments using HAdV-C5-Luciferase vector (HAdV5-Luc), as preincubation of HAdV5-Luc with GLA(mim) before FX addition resulted in a higher transgene expression compared with FX alone. HAdV-C5 virions complexed with GLA(mim) were analyzed by cryoelectron microscopy. Image reconstruction demonstrated the bona fide hexon-GLA(mim) interaction, as for the full-length FX, although with considerable differences in stoichiometry and relative location on the hexon capsomer. Three extra densities were found at the periphery of each hexon, whereas one single FX molecule occupied the central cavity of the hexon trimeric capsomer. A refined analysis indicated that each extra density is found at the expected location of one highly variable loop 1 of the hexon, involved in scavenger receptor recognition. HAdV5-Luc complexed with a bifunctional GLA(mim)RGD peptide showed a lesser hepatotropism, compared with control HAdV5-Luc alone, and efficiently targeted αβ-integrin-overexpressing tumor cells in an in vivo mouse tumor model. Collectively, our findings open new perspectives in the design of adenoviral vectors for biotherapy.

Liu P, Cai Z, Kang JW, et al.
Intracellular routing in breast cancer cells of streptavidin-conjugated trastuzumab Fab fragments linked to biotinylated doxorubicin-functionalized metal chelating polymers.
Biomacromolecules. 2014; 15(3):715-25 [PubMed] Related Publications
We describe the synthesis of a heterotelechelic metal-chelating polymer (Bi-MCP-Dox), a polyacrylamide with a number average degree of polymerization DPn = 50 (PDI = 1.2), with biotin (Bi) and doxorubicin (Dox) as functional chain ends and diethylenetriaminepentaacetic acid (DTPA) pendant groups as the binding sites for metal ions. We compared its behavior in cell-uptake experiments with a similar polymer (Bi-MCP) without Dox. These MCPs were complexed with trastuzumab Fab (tmFab) fragments covalently linked to streptavidin (SAv) to form tmFab-SAv-Bi-MCP-Dox and tmFab-SAv-Bi-MCP via the strong affinity between Bi and SAv. tmFab targets human epidermal growth factor receptor-2 (HER2), which is overexpressed on certain human breast cancer cells. Surface plasmon resonance (SPR) experiments with the extracellular domain (ECD) of HER2 showed that incorporation of the MCPs in these complexes had no significant effect on the association or dissociation rate with the HER2 ECD and the dissociation constants. The tmFab-complexed MCPs were subsequently labeled with (111)In (an Auger electron emitting radionuclide). Auger electrons can cause lethal DNA double strand breaks (DSBs) but only if they are emitted intracellularly and especially, in close proximity to the nucleus. To evaluate the cellular and nuclear uptake of tmFab-SAv-Bi-MCP-Dox, we incubated HER2+ SK-BR-3 human breast cancer cells with the complexes saturated with stable In(3+) and visualized their distribution by confocal fluorescence microscopy, monitoring the fluorescence of Dox. In parallel, we carried out cell fractionation studies on tmFab-SAv-Bi-MCP-Dox and on tmFab-SAv-Bi-MCP labeled with (111)In. Both radiolabeled complexes showed cell internalization and nuclear localization. We conclude that metal-chelating polymers with this composition appear to encourage internalization, nuclear uptake, and chromatin (DNA) binding of trastuzumab fragments modified with streptavidin in human breast cancer cells expressing HER2. Further study is needed to understand the impact of polymer charge on cellular uptake and distribution to intracellular compartments.

Berger M, Neth O, Ilmer M, et al.
Hepatoblastoma cells express truncated neurokinin-1 receptor and can be growth inhibited by aprepitant in vitro and in vivo.
J Hepatol. 2014; 60(5):985-94 [PubMed] Related Publications
BACKGROUND & AIMS: Multidrug resistance presents a major problem in hepatoblastoma (HB), and new anti-tumor strategies are desperately needed. The substance P (SP)/neurokinin-1 receptor (NK1R) complex has been discovered to be pivotal in the development of a variety of human cancers, and NK1R antagonists, such as the clinical drug aprepitant, are promising future anticancer agents. Yet, the role of the SP/NK1R complex as a potential anticancer target in HB is unknown.
METHODS: Human HB cell lines HepT1, HepG2, and HuH6, human tumor samples from 17 children with HB as well as mice xenografted with human HB cell line HuH6 were analyzed regarding the SP/NK1R complex as a potential new anti-tumor target in HB.
RESULTS: Therapeutic targeting with the NK1R antagonists aprepitant, L-733,060, and L-732,138 led to growth inhibition and apoptosis in HepT1, HepG2, and HuH6 cells in a dose-dependent manner. Intriguingly, HB cells predominantly expressed the truncated splice variant of NK1R. Human fibroblasts showed only dismal NK1R expression and were significantly more resistant. Stimulation of HB cells with SP, NK1R's natural ligand, caused increased growth rates and abrogated the anti-proliferative effect of NK1R antagonists. Expression analysis of 17 human HB samples confirmed the clinical relevance of NK1R. Most importantly, oral treatment of a HuH6 xenograft mouse model with 80mg/kg/day aprepitant for 24days resulted in a striking reduction of tumor growth, as evidenced by reduced tumor volume and weight, lowered tumor-specific alpha-fetoprotein (AFP) serum levels, and decreased number of Ki-67 positive cells. Furthermore, aprepitant treatment inhibited in vivo angiogenesis.
CONCLUSIONS: For the first time, we describe the NK1R in its truncated splice variant as a potent target in human HB and an inhibitory effect in vivo and in vitro by NK1R antagonists. Therefore, NK1R antagonists should be considered promising new candidates for innovative therapeutic strategies against HB.

Menegazzi M, Mariotto S, Dal Bosco M, et al.
Direct interaction of natural and synthetic catechins with signal transducer activator of transcription 1 affects both its phosphorylation and activity.
FEBS J. 2014; 281(3):724-38 [PubMed] Related Publications
Our previous studies showed that (-)-epigallocatechin-3-gallate (EGCG) inhibits signal transducer activator of transcription 1 (STAT1) activation. Since EGCG may be a promising lead compound for new anti-STAT1 drug design, 15 synthetic catechins, characterized by the (-)-gallocatechin-3-gallate stereochemistry, were studied in the human mammary MDA-MB-231 cell line to identify the minimal structural features that preserve the anti-STAT1 activity. We demonstrate that the presence of three hydroxyl groups of B ring and one hydroxyl group in D ring is essential to preserve their inhibitory action. Moreover, a possible molecular target of these compounds in the STAT1 pathway was investigated. Our results demonstrate a direct interaction between STAT1 protein and catechins displaying anti-STAT1 activity. In particular, surface plasmon resonance (SPR) analysis and molecular modeling indicate the presence of two putative binding sites (a and b) with different affinity. Based on docking data, site-directed mutagenesis was performed, and interaction of the most active catechins with STAT1 was studied with SPR to test whether Gln518 on site a and His568 on site b could be important for the catechin-STAT1 interaction. Data indicate that site b has higher affinity for catechins than site a as the highest affinity constant disappears in the H568A-STAT1 mutant. Furthermore, Janus kinase 2 (JAK2) kinase assay data suggest that the contemporary presence in vitro of STAT1 and catechins inhibits JAK2-elicited STAT1 phosphorylation. The very tight catechin-STAT1 interaction prevents STAT1 phosphorylation and represents a novel, specific and efficient molecular mechanism for the inhibition of STAT1 activation.

Muñoz M, Berger M, Rosso M, et al.
Antitumor activity of neurokinin-1 receptor antagonists in MG-63 human osteosarcoma xenografts.
Int J Oncol. 2014; 44(1):137-46 [PubMed] Related Publications
Osteosarcoma is a highly malignant bone tumor in children and adolescents. Aprepitant is a selective high‑affinity antagonist of the human neurokinin‑1 (NK‑1) receptor (NK1R) with robust antitumor activity. No data exist on the presence of NK1R in osteosarcoma and whether this tumor responds to NK1R antagonists. Here, we analyzed the expression of NK1R in the human osteosarcoma cell line MG-63 with western blot analysis and PCR and found significant expression both at the protein and mRNA levels. We further studied the growth inhibitory capacity of aprepitant and other NK1R antagonists on MG-63 in vitro using an MTS cytotoxicity assay and DAPI staining. All antagonists induced tumor growth inhibition and apoptosis. Synergism was observed for the combination of L-733,060 with common cytostatic drugs in MG-63, but not in non-malignant HEK293 cells. Pretreatment of HEK293 with L-733,060 prior to exposure to cytostatic drugs partially protected HEK293 cells from inhibition by these drugs. Furthermore, nanomolar concentrations of substance P (SP), the natural ligand of the NK1R, increased the growth rate of MG‑63 cells and micromolar concentrations of aprepitant inhibited SP-induced growth in a dose‑dependent manner. In vivo, a xenograft for MG-63 was created in nude mice and treated with peritumoral s.c. injections of fosaprepitant, which resulted in a significant reduction of tumor volume. Collectively, we demonstrated for the first time that the NK1R is expressed in human osteosarcoma cell line MG‑63 and that this receptor can be targeted with NK1R antagonists both in vitro as well as in vivo.

Lange I, Geerts D, Feith DJ, et al.
Novel interaction of ornithine decarboxylase with sepiapterin reductase regulates neuroblastoma cell proliferation.
J Mol Biol. 2014; 426(2):332-46 [PubMed] Free Access to Full Article Related Publications
Ornithine decarboxylase (ODC) is the sentinel enzyme in polyamine biosynthesis. Both ODC and polyamines regulate cell division, proliferation, and apoptosis. Sepiapterin reductase (SPR) catalyzes the last step in the biosynthesis of tetrahydrobiopterin (BH4), an essential cofactor of nitric oxide synthase, and has been implicated in neurological diseases but not yet in cancer. In this study, we present compelling evidence that native ODC and SPR physically interact, and we defined the individual amino acid residues involved in both enzymes using in silico protein-protein docking simulations. The resulting heterocomplex is a surprisingly compact structure, featuring two energetically and structurally equivalent binding modes both in monomer and in dimer conformations. The novel interaction between ODC and SPR proteins was confirmed under physiological conditions by co-immunoprecipitation and co-localization in neuroblastoma (NB) cells. Importantly, we showed that siRNA (small interfering RNA)-mediated knockdown of SPR expression significantly reduced endogenous ODC enzyme activity in NB cells, thus demonstrating the biological relevance of the ODC-SPR interaction. Finally, in a cohort of 88 human NB tumors, we found that high SPR mRNA expression correlated significantly with poor survival prognosis using a Kaplan-Meier analysis (log-rank test, P=5 × 10(-4)), suggesting an oncogenic role for SPR in NB tumorigenesis. In conclusion, we showed that ODC binds SPR and thus propose a new concept in which two well-characterized biochemical pathways converge via the interaction of two enzymes. We identified SPR as a novel regulator of ODC enzyme activity and, based on clinical evidence, present a model in which SPR drives ODC-mediated malignant progression in NB.

Wang Y, Ren X, Deng C, et al.
Mechanism of the inhibition of the STAT3 signaling pathway by EGCG.
Oncol Rep. 2013; 30(6):2691-6 [PubMed] Related Publications
Signal transducer and activator of transcription 3 (STAT3) is an oncogene that promotes cell survival, proliferation, and motility. In the present study, we explored the mechanism involved in the inhibition by epigallocatechin-3-gallate (EGCG) of STAT3 signaling as detected by surface plasmon resonance (SPR)-binding assays and in silico docking. Stat3‑binding assay indicated that EGCG significantly interrupted Stat3 peptide binding at micromolar concentrations, and the docking experiments indicated that EGCG had a strong interaction with Arg-609, one of the key residues in the STAT3 SH2 domain that contributes greatly to Stat3 and phosphorylated peptide binding. Following treatment of the hepatocellular carcinoma cell lines BEL-7402 and QGY-7703 with EGCG, in vitro, EGCG significantly suppressed cell proliferation as detected by MTT assay, induced apoptosis as detected by flow cytometry, dramatically lowered the expression levels of phosphorylated Stat3 proteins (p-Stat3) as determined by immunoblot detection, and inhibited the expression of multiple genes including Bcl-xL, c-Myc, VEGF and cyclin D1 as demonstrated by RT-PCR analysis. In conclusion, our research data indicate that the anticancer function of green tea results from the inhibition of the STAT3 signaling pathway by EGCG.

Garcia-Recio S, Fuster G, Fernandez-Nogueira P, et al.
Substance P autocrine signaling contributes to persistent HER2 activation that drives malignant progression and drug resistance in breast cancer.
Cancer Res. 2013; 73(21):6424-34 [PubMed] Related Publications
ERBB receptor transmodulation by heterologous G-protein-coupled receptors (GPCR) generates functional diversity in signal transduction. Tachykinins are neuropeptides and proinflammatory cytokines that promote cell survival and cancer progression by activating several GPCRs. In this work, we found that the pain-associated tachykinin Substance P (SP) contributes to persistent transmodulation of the ERBB receptors, EGFR and HER2, in breast cancer, acting to enhance malignancy and therapeutic resistance. SP and its high-affinity receptor NK-1R were highly expressed in HER2(+) primary breast tumors (relative to the luminal and triple-negative subtypes) and were overall correlated with poor prognosis factors. In breast cancer cell lines and primary cultures derived from breast cancer samples, we found that SP could activate HER2. Conversely, RNA interference-mediated attenuation of NK-1R, or its chemical inhibition, or suppression of overall GPCR-mediated signaling, all strongly decreased steady-state expression of EGFR and HER2, establishing that their basal activity relied upon transdirectional activation by GPCR. Thus, SP exposure affected cellular responses to anti-ERBB therapies. Our work reveals an important oncogenic cooperation between NK-1R and HER2, thereby adding a novel link between inflammation and cancer progression that may be targetable by SP antagonists that have been clinically explored.

Kogelberg H, Miranda E, Burnet J, et al.
Generation and characterization of a diabody targeting the αvβ6 integrin.
PLoS One. 2013; 8(9):e73260 [PubMed] Free Access to Full Article Related Publications
The αvβ6 integrin is up-regulated in cancer and wound healing but it is not generally expressed in healthy adult tissue. There is increasing evidence that it has a role in cancer progression and will be a useful target for antibody-directed cancer therapies. We report a novel recombinant diabody antibody fragment that targets specifically αvβ6 and blocks its function. The diabody was engineered with a C-terminal hexahistidine tag (His tag), expressed in Pichia pastoris and purified by IMAC. Surface plasmon resonance (SPR) analysis of the purified diabody showed affinity in the nanomolar range. Pre-treatment of αvβ6-expressing cells with the diabody resulted in a reduction of cell migration and adhesion to LAP, demonstrating biological function-blocking activity. After radio-labeling, using the His-tag for site-specific attachment of (99m)Tc, the diabody retained affinity and targeted specifically to αvβ6-expressing tumors in mice bearing isogenic αvβ6 +/- xenografts. Furthermore, the diabody was specifically internalized into αvβ6-expressing cells, indicating warhead targeting potential. Our results indicate that the new αvβ6 diabody has a range of potential applications in imaging, function blocking or targeted delivery/internalization of therapeutic agents.

Shen C, Jo SY, Liao C, et al.
Targeting recruitment of disruptor of telomeric silencing 1-like (DOT1L): characterizing the interactions between DOT1L and mixed lineage leukemia (MLL) fusion proteins.
J Biol Chem. 2013; 288(42):30585-96 [PubMed] Free Access to Full Article Related Publications
The MLL fusion proteins, AF9 and ENL, activate target genes in part via recruitment of the histone methyltransferase DOT1L (disruptor of telomeric silencing 1-like). Here we report biochemical, biophysical, and functional characterization of the interaction between DOT1L and MLL fusion proteins, AF9/ENL. The AF9/ENL-binding site in human DOT1L was mapped, and the interaction site was identified to a 10-amino acid region (DOT1L865-874). This region is highly conserved in DOT1L from a variety of species. Alanine scanning mutagenesis analysis shows that four conserved hydrophobic residues from the identified binding motif are essential for the interactions with AF9/ENL. Binding studies demonstrate that the entire intact C-terminal domain of AF9/ENL is required for optimal interaction with DOT1L. Functional studies show that the mapped AF9/ENL interacting site is essential for immortalization by MLL-AF9, indicating that DOT1L interaction with MLL-AF9 and its recruitment are required for transformation by MLL-AF9. These results strongly suggest that disruption of interaction between DOT1L and AF9/ENL is a promising therapeutic strategy with potentially fewer adverse effects than enzymatic inhibition of DOT1L for MLL fusion protein-associated leukemia.

Muñoz M, Coveñas R
Involvement of substance P and the NK-1 receptor in cancer progression.
Peptides. 2013; 48:1-9 [PubMed] Related Publications
Many data suggest the deep involvement of the substance P (SP)/neurokinin (NK)-1 receptor system in cancer: (1) Tumor cells express SP, NK-1 receptors and mRNA for the tachykinin NK-1 receptor; (2) Several isoforms of the NK-1 receptor are expressed in tumor cells; (3) the NK-1 receptor is involved in the viability of tumor cells; (4) NK-1 receptors are overexpressed in tumor cells in comparison with normal ones and malignant tissues express more NK-1 receptors than benign tissues; (5) Tumor cells expressing the most malignant phenotypes show an increased percentage of NK-1 receptor expression; (6) The expression of preprotachykinin A is increased in tumor cells in comparison with the levels found in normal cells; (7) SP induces the proliferation and migration of tumor cells and stimulates angiogenesis by increasing the proliferation of endothelial cells; (8) NK-1 receptor antagonists elicit the inhibition of tumor cell growth; (9) The specific antitumor action of NK-1 receptor antagonists on tumor cells occurs through the NK-1 receptor; (10) Tumor cell death is due to apoptosis; (11) NK-1 receptor antagonists inhibit the migration of tumor cells and neoangiogenesis. The NK-1 receptor is a therapeutic target in cancer and NK-1 receptor antagonists could be considered as broad-spectrum antitumor drugs for the treatment of cancer. It seems that a common mechanism for cancer cell proliferation mediated by SP and the NK-1 receptor is triggered, as well as a common mechanism exerted by NK-1 receptor antagonists on tumor cells, i.e. apoptosis.

Zhou Y, Zhao L, Xiong T, et al.
Roles of full-length and truncated neurokinin-1 receptors on tumor progression and distant metastasis in human breast cancer.
Breast Cancer Res Treat. 2013; 140(1):49-61 [PubMed] Related Publications
Substance P (SP) regulates various physiologic and pathophysiologic responses predominantly by acting through its primary receptor, the neurokinin-1 receptor (NK1R). There are two naturally occurring forms of NK1R: full-length NK1R-FL and truncated NK1R-Tr. SP-coupled NK1R can directly or indirectly regulate the proliferation and metastatic progression of many types of human cancer cells. However, the exact roles played by the two isoforms of NK1R in breast carcinogenesis still remain largely unclear. In the present study, we first examined the expression profile of total NK1Rs, NK1R-FL and NK1R-Tr in multiple breast cancer cell lines as well as in breast tumor samples. We found that total NK1Rs are present in normal, benign and breast tumor tissues; while, NK1R-FL expression are significantly decreased in tumor specimens, particularly in metastatic carcinomas. More interestingly, NK1R-FL is highly expressed in nontumorigenic HBL-100 breast cells, whereas MDA-MB-231, MCF-7 and T47D breast cancer cells express only NK1R-Tr. To further investigate potential implications of NK1R-FL and NK1R-Tr in the malignant phenotypes of breast cancer, we studied the impacts of ectopically overexpressed NK1R-FL and NK1R-Tr in MDA-MB-231 and HBL-100 cells, respectively. Our in vitro and in vivo data showed that NK1R-FL expression was inversely associated with proliferation, invasiveness and metastasis of MDA-MB-231 cells, but overexpression of NK1R-Tr was able to promote malignant transformation of HBL-100 cells and NK1R-Tr may contribute to tumor progression and promote distant metastasis in human breast cancer. A long-term treatment of NK1R antagonist ASN-1377642 exerted antitumor action in breast cancer cells with NK1R-Tr high expression.

Zhang Z, Miao L, Lv C, et al.
Wentilactone B induces G2/M phase arrest and apoptosis via the Ras/Raf/MAPK signaling pathway in human hepatoma SMMC-7721 cells.
Cell Death Dis. 2013; 4:e657 [PubMed] Free Access to Full Article Related Publications
Hepatocellular carcinoma (HCC) is generally acknowledged as the most common primary malignant tumor, and it is known to be resistant to conventional chemotherapy. Wentilactone B (WB), a tetranorditerpenoid derivative extracted from the marine algae-derived endophytic fungus Aspergillus wentii EN-48, has been shown to trigger apoptosis and inhibit metastasis in HCC cell lines. However, the mechanisms of its antitumor activity remain to be elucidated. We report here that WB could significantly induce cell cycle arrest at G2 phase and mitochondrial-related apoptosis, accompanying the accumulation of reactive oxygen species (ROS). Additionally, treatment with WB induced phosphorylation of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), but not p38 MAP kinase. Among the pathway inhibitors examined, only SP600125 (JNK inhibitor) markedly reversedWB-induced apoptosis, and only U0126 (ERK inhibitor) significantly blocked WB-triggered G2 phase arrest. We also found that WB treatment increased both Ras and Raf activation, and transfection of cells with dominant-negative Ras (RasN17) abolishedWB-induced apoptosis and G2 phase arrest in SMMC-7721 cells. Furthermore, the results of inverse docking (INVDOCK) analysis suggested that WB could bind to Ras-GTP, and the direct binding affinity was also confirmed by surface plasmon resonance (SPR). Finally, in vivo, WB suppressed tumor growth in mouse xenograft models. Taken together, these results indicate that WB induced G2/M phase arrest and apoptosis in human hepatoma SMMC-7721 cells via the Ras/Raf/ERK and Ras/Raf/JNK signaling pathways, and this agent may be a potentially useful compound for developing anticancer agents for HCC.

Madura F, Rizkallah PJ, Miles KM, et al.
T-cell receptor specificity maintained by altered thermodynamics.
J Biol Chem. 2013; 288(26):18766-75 [PubMed] Free Access to Full Article Related Publications
The T-cell receptor (TCR) recognizes peptides bound to major histocompatibility molecules (MHC) and allows T-cells to interrogate the cellular proteome for internal anomalies from the cell surface. The TCR contacts both MHC and peptide in an interaction characterized by weak affinity (KD = 100 nM to 270 μM). We used phage-display to produce a melanoma-specific TCR (α24β17) with a 30,000-fold enhanced binding affinity (KD = 0.6 nM) to aid our exploration of the molecular mechanisms utilized to maintain peptide specificity. Remarkably, although the enhanced affinity was mediated primarily through new TCR-MHC contacts, α24β17 remained acutely sensitive to modifications at every position along the peptide backbone, mimicking the specificity of the wild type TCR. Thermodynamic analyses revealed an important role for solvation in directing peptide specificity. These findings advance our understanding of the molecular mechanisms that can govern the exquisite peptide specificity characteristic of TCR recognition.

Misawa K, Kanazawa T, Misawa Y, et al.
Frequent promoter hypermethylation of tachykinin-1 and tachykinin receptor type 1 is a potential biomarker for head and neck cancer.
J Cancer Res Clin Oncol. 2013; 139(5):879-89 [PubMed] Related Publications
AIM: The aim of this study was to define TAC1 and TACR1 methylation profiles for head and neck squamous cell carcinoma (HNSCC) tumors at diagnosis and follow-up and to evaluate their prognostic significance and value as a biomarker of recurrence.
MATERIALS AND METHODS: TAC1 and TACR1 expression was measured in a panel of cell lines by quantitative RT-PCR. The TAC1 and TACR1 promoter methylation status was determined by quantitative methylation-specific PCR.
RESULTS: Methylation was associated with TAC1 and TACR1 transcription inhibition. TAC1 methylation in 49/100 (49 %) of HNSCC tumor specimens significantly correlated with p16 methylation (P = 0.010), E-cadherin methylation (P = 0.041), galanin methylation (P = 0.037), and disease-free survival (P = 0.002). Stage III and IV patients manifesting TAC1 hypermethylation had significantly shorter survivals than did patients without TAC1 methylation (P = 0.022). TACR1 methylation in 34/100 (34 %) cases was significantly correlated with galanin methylation (P = 0.014) and GALR1 methylation (P = 0.004). TAC1 promoter hypermethylation was statistically correlated with reduced disease-free survival (log-rank test, P = 0.002). In multivariate logistic-regression analysis, methylation of TAC1 and of the gene pair TAC1 and TACR1 was associated with an odds ratio for recurrence of 3.35 (95 % CI, 1.37-8.19; P = 0.008) and 5.09 (95 % CI, 1.44-18.02; P = 0.011), respectively.
CONCLUSION: CpG hypermethylation is a likely mechanism of TAC1 and TACR1 gene inactivation, supporting the hypothesis that TAC1 and TACR1 play a role in the tumorigenesis of HNSCC and that this hypermethylation may serve as an important biomarker.

Li X, Ma G, Ma Q, et al.
Neurotransmitter substance P mediates pancreatic cancer perineural invasion via NK-1R in cancer cells.
Mol Cancer Res. 2013; 11(3):294-302 [PubMed] Free Access to Full Article Related Publications
Pancreatic cancer significantly affects the quality of life due to the severe abdominal pain. However, the underlying mechanism is not clear. This study aimed to determine the relationship between Substance P (SP) and pancreatic cancer perineural invasion (PNI) as well as the mechanism of SP mediating pancreatic cancer PNI, which causes pain in patients with pancreatic cancer. Human pancreatic cancer cells and newborn dorsal root ganglions (DRG) were used to determine the expression of SP or NK-1R in pancreatic cancer cells and DRGs cells by QT-PCR and Western blotting. The effects of SP on pancreatic cancer cell proliferation and invasion were analyzed using MTT assay and Transwell Matrigel invasion assay, respectively. Alterations in the neurotropism of pancreatic cancer cells were assessed by coculture system, which mimics the interaction of tumor/neuron in vivo. SP is not only widely distributed in the neurite outgrowth from newborn DRGs but also expressed in MIA PaCa-2 and BxPC-3 cells. NK-1R is found to be overexpressed in the pancreatic cancer cell lines examined. SP induces cancer cell proliferation and invasion as well as the expression of matrix metalloproteinase (MMP)-2 in pancreatic cancer cells, and NK-1R antagonists inhibit these effects. Furthermore, SP promotes neurite outgrowth and the migration of pancreatic cancer cell cluster to the DRGs, which is blocked by NK-1R antagonists in the coculture model. Our results suggest that SP plays an important role in the development of pancreatic cancer metastasis and PNI, and blocking the SP/NK-1R signaling system is a novel strategy for the treatment of pancreatic cancer.

Fratelli M, Fisher JN, Paroni G, et al.
New insights into the molecular mechanisms underlying sensitivity/resistance to the atypical retinoid ST1926 in acute myeloid leukaemia cells: the role of histone H2A.Z, cAMP-dependent protein kinase A and the proteasome.
Eur J Cancer. 2013; 49(6):1491-500 [PubMed] Related Publications
ST1926 is an atypical retinoid and a promising anti-tumour agent with selective apoptotic activity on the leukaemic blast. The anti-tumour activity of the compound has been associated with its capacity to induce DNA double stranded breaks. Target profiling by affinity chromatography coupled to mass spectrometry led to the identification of histone H2A.Z as a protein capable of binding ST1926 specifically. The result was confirmed by studies involving Surface Plasmon Resonance (SPR). This indicates that H2A.Z is a primary target of ST1926 and links the perturbations of the histone pathway observed by microarray analysis to the DNA damage and apoptotic responses caused by the atypical retinoid. Comparison of the whole-genome gene-expression profiles of the ST1926-sensitive NB4 and the ST1926-resistant NB4.437r cell lines demonstrated differential expression of numerous genes. Network analysis of the data indicated enrichment of the cellular pathways controlling cAMP (cyclic adenosine-monophosphate)-dependent signal transduction, proteasome-dependent protein degradation and nuclear histones in NB4.437r cells. Pharmacological inhibition of cAMP-dependent protein kinase A with H89 partially reverted resistance of NB4.437r cells to ST1926. Conversely, inhibition of the proteasome with MG132 or bortezomib blocked the apoptotic response afforded by ST1926 in the NB4 cell line. This last effect was associated with a dramatic reduction in the DNA damage caused by the atypical retinoid. The results corroborate the idea that DNA damage is an important determinant of ST1926 apoptotic activity. More importantly, they demonstrate a proactive role of the proteasome in the DNA damaging and ensuing apoptotic response observed upon the challenge of acute myeloid leukaemia cells with ST1926.

Garg R, Kapoor V, Mittal M, et al.
Abnormal expression of PI3K isoforms in patients with tobacco-related oral squamous cell carcinoma.
Clin Chim Acta. 2013; 416:100-6 [PubMed] Related Publications
BACKGROUND: The phosphatidylinositol 3-kinase (PI3K) signaling regulates several cellular functions such as motility, proliferation, angiogenesis and survival.
METHODS: Since there is no information on expression of PI3K isoforms in oral cancer, we studied the expression of different isoforms of PI3K (p110α, p110γ, PI3K-C2, Vps34p and p85α) in tumor samples and PBMC by RT and q-RTPCR and serum levels of PI3K p110α by SPR and ELISA techniques in 108 patients with tobacco-related oral squamous cell carcinoma (OSCC) and 46 normal subjects.
RESULTS: We observed significantly higher PI3K p110α (p<0.0001) and lower (p<0.0001) vesicular sorting protein 34p (Vps34p) mRNA both in PBMC and tissue samples of oral cancer patients as compared to the normal controls. Other PI3K isoforms did not show such change. Circulating PI3K p110α levels were higher in patients (p<0.0001) as compared to healthy subjects, the SPR data showed direct correlation with advancing stage of the disease. PI3K p110α was overexpressed in tumor samples but not in the normal buccal mucosa.
CONCLUSIONS: Upregulation of circulating PI3K p110α isoform and its direct correlation with increasing tumor load in OSCC patients indicates that it may be a significant prognostic indicator and a suitable target for therapeutic/chemo-preventive strategies for tobacco-related OSCC.

Mou L, Kang Y, Zhou Y, et al.
Neurokinin-1 receptor directly mediates glioma cell migration by up-regulation of matrix metalloproteinase-2 (MMP-2) and membrane type 1-matrix metalloproteinase (MT1-MMP).
J Biol Chem. 2013; 288(1):306-18 [PubMed] Free Access to Full Article Related Publications
Neurokinin-1 receptor (NK1R) occurs naturally on human glioblastomas. Its activation mediates glioma cell proliferation. However, it is unknown whether NK1R is directly involved in tumor cell migration. In this study, we found human hemokinin-1 (hHK-1), via NK1R, dose-dependently promoted the migration of U-251 and U-87 cells. In addition, we showed that hHK-1 enhanced the activity of MMP-2 and the expression of MMP-2 and MT1-matrix metalloproteinase (MMP), which were responsible for cell migration, because neutralizing the MMPs with antibodies decreased cell migration. The involved mechanisms were then investigated. In U-251, hHK-1 induced significant calcium efflux; phospholipase C inhibitor U-73122 reduced the calcium mobilization, the up-regulation of MMP-2 and MT1-MMP, and the cell migration induced by hHK-1, which meant the migration effect of NK1R was mainly mediated through the G(q)-PLC pathway. We further demonstrated that hHK-1 boosted rapid phosphorylation of ERK, JNK, and Akt; inhibition of ERK and Akt effectively reduced MMP-2 induction by hHK-1. Meanwhile, inhibition of ERK, JNK, and Akt reduced the MT1-MMP induction. hHK-1 stimulated significant phosphorylation of p65 and c-JUN in U-251. Reporter gene assays indicated hHK-1 enhanced both AP-1 and NF-κB activity; inhibition of ERK, JNK, and Akt dose-dependently suppressed the NF-κB activity; only the inhibition of ERK significantly suppressed the AP-1 activity. Treatment with specific inhibitors for AP-1 or NF-κB strongly blocked the MMP up-regulation by hHK-1. Taken together, our data suggested NK1R was a potential regulator of human glioma cell migration by the up-regulation of MMP-2 and MT1-MMP.

Muñoz M, González-Ortega A, Rosso M, et al.
The substance P/neurokinin-1 receptor system in lung cancer: focus on the antitumor action of neurokinin-1 receptor antagonists.
Peptides. 2012; 38(2):318-25 [PubMed] Related Publications
The last decades have seen no significant progress in extending the survival of lung cancer patients and there is an urgent need to improve current therapies. The substance P (SP)/neurokinin-1 receptor (NK-1R) system plays an important role in the development of cancer: SP and NK-1R antagonists respectively induce cell proliferation and inhibition in human cancer cell lines. No study of the involvement of this system in non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC) cells has been carried out in depth. Here, we demonstrate the involvement of the SP/NK-1R system in human H-69 (SCLC) and COR-L23 (NSCLC) cell lines: (1) they express isoforms of the NK-1R and mRNA for the NK-1R; (2) they overexpress the tachykinin 1 gene; (3) the NK-1R is involved in their viability; (4) SP induces their proliferation; (5) NK-1R antagonists (Aprepitant (Emend), L-733,060, L-732,138) inhibit the growth of both cell lines in a concentration-dependent manner; (6) the specific antitumor action of these antagonists against such cells occurs through the NK-1R; and (7) lung cancer cell death is due to apoptosis. We also demonstrate the presence of NK-1Rs and SP in all the human SCLC and NSCLC samples studied. Our findings indicate that the NK-1R may be a promising new target in the treatment of lung cancer and that NK-1R antagonists could be new candidate antitumor drugs in the treatment of SCLC and NSCLC.

Navarro P, Ramkissoon SH, Shah S, et al.
An indirect role for oncomir-519b in the expression of truncated neurokinin-1 in breast cancer cells.
Exp Cell Res. 2012; 318(20):2604-15 [PubMed] Free Access to Full Article Related Publications
Neurokinin 1 (NK1) encodes full-length (NK1-FL) and truncated (NK1-Tr) receptors, with distinct 3' UTR. NK1-Tr exerts oncogenic functions and is increased in breast cancer (BC). Enhanced transcription of NK1 resulted in higher level of NK1-Tr. The 3' UTR of these two transcripts are distinct with NK1-Tr terminating at a premature stop codon. NK1-Tr mRNA gained an advantage over NK1-FL with regards to translation. This is due to the ability of miR519B to interact with sequences within the 3' UTR of NK1-FL, but not NK1-Tr since the corresponding region is omitted. MiR519b suppressed the translation of NK1-FL in T47D and MDA-MB-231 resulting in increased NK1-Tr protein. Cytokines can induce the transcription of NK1. However, our studies indicated that translation appeared to be independent of cytokine production by the BC cells (BCCs). This suggested that transcription and translation of NK1 might be independent. The findings were validated in vivo. MiR-519b suppressed the growth of MDA-MB-231 in 7/10 nude BALB/c. In total, increased NK1-Tr in BCCs is due to enhanced transcription and suppressed translation of NK1-FL by miR-519b to reduced tumor growth. In summary, we report on miRNA as a method to further regulate the expression of a spiced variant to promote oncogenesis. In addition, the findings have implications for therapy with NK1 antagonists. The oncogenic effect of NK1-Tr must be considered to improve the efficacy of current drugs to NK1.

Yu Y, Pan Y, Jin M, et al.
Association of genetic variants in tachykinins pathway genes with colorectal cancer risk.
Int J Colorectal Dis. 2012; 27(11):1429-36 [PubMed] Related Publications
PURPOSE: This study aims to explore the associations of polymorphisms in tachykinin, precursor 1 (TAC1), tachykinin receptor 1 (TACR1), and tachykinin receptor 2 (TACR2) genes and their interactions with the risk of colorectal cancer (CRC) among Chinese population.
METHODS: A population-based case-control study which included 394 cases and 393 cancer-free controls was carried out. A total of 19 tagSNPs in the three genes were chosen based on HapMap and NCBI datasets and genotyped by SNPshot assay. Multiple logistic regression models were applied to evaluate the associations of SNPs with CRC after adjustment for potential covariates. Furthermore, generalized multifactor dimensionality reduction (GMDR) method was used to test the interactive effect among three genes on CRC.
RESULTS: Compared with those carrying rs3755457 CC/CT or rs12477554 TT/CT genotype, individuals carrying homozygous variants had higher risk of colorectal cancer (adjusted OR = 1.80, 95 % CI = 1.03-3.13, P = 0.039 for rs3755457; adjusted OR = 1.73, 95 % CI = 1.07-2.79, P = 0.024 for rs12477554). As for rs10198644, GG genotype was associated with a 1.72-fold (95 % CI = 0.37-0.88) decreased risk when compared with the common CC genotype. Moreover, the GMDR analysis indicated that the best interactive model included five polymorphisms: rs2072100 (TAC1), rs10198644 (TACR1), rs2193409 (TACR1), rs3771810 (TACR1), and rs4644560 (TACR2).
CONCLUSIONS: Our study suggests that tachykinins pathway genes may participate in the development of CRC and the potential interactions among the three genes on CRC may exist, which has to be confirmed in future larger studies.

Malmberg J, Perols A, Varasteh Z, et al.
Comparative evaluation of synthetic anti-HER2 Affibody molecules site-specifically labelled with 111In using N-terminal DOTA, NOTA and NODAGA chelators in mice bearing prostate cancer xenografts.
Eur J Nucl Med Mol Imaging. 2012; 39(3):481-92 [PubMed] Related Publications
PURPOSE: In disseminated prostate cancer, expression of human epidermal growth factor receptor type 2 (HER2) is one of the pathways to androgen independence. Radionuclide molecular imaging of HER2 expression in disseminated prostate cancer might identify patients for HER2-targeted therapy. Affibody molecules are small (7 kDa) targeting proteins with high potential as tracers for radionuclide imaging. The goal of this study was to develop an optimal Affibody-based tracer for visualization of HER2 expression in prostate cancer.
METHODS: A synthetic variant of the anti-HER2 Z(HER2:342) Affibody molecule, Z(HER2:S1), was N-terminally conjugated with the chelators DOTA, NOTA and NODAGA. The conjugated proteins were biophysically characterized by electrospray ionization mass spectroscopy (ESI-MS), circular dichroism (CD) spectroscopy and surface plasmon resonance (SPR)-based biosensor analysis. After labelling with (111)In, the biodistribution was assessed in normal mice and the two most promising conjugates were further evaluated for tumour targeting in mice bearing DU-145 prostate cancer xenografts.
RESULTS: The HER2-binding equilibrium dissociation constants were 130, 140 and 90 pM for DOTA-Z(HER2:S1), NOTA-Z(HER2:S1) and NODAGA-Z(HER2:S1), respectively. A comparative study of (111)In-labelled DOTA-Z(HER2:S1), NOTA-Z(HER2:S1) and NODAGA-Z(HER2:S1) in normal mice demonstrated a substantial influence of the chelators on the biodistribution properties of the conjugates. (111)In-NODAGA-Z(HER2:S1) had the most rapid clearance from blood and healthy tissues. (111)In-NOTA-Z(HER2:S1) showed high hepatic uptake and was excluded from further evaluation. (111)In-DOTA-Z(HER2:S1) and (111)In-NODAGA-Z(HER2:S1) demonstrated specific uptake in DU-145 prostate cancer xenografts in nude mice. The tumour uptake of (111)In-NODAGA-Z(HER2:S1), 5.6 ± 0.4%ID/g, was significantly lower than the uptake of (111)In-DOTA-Z(HER2:S1), 7.4 ± 0.5%ID/g, presumably because of lower bioavailability due to more rapid clearance. (111)In-NODAGA-Z(HER2:S1) provided higher tumour-to-blood ratio, but somewhat lower tumour-to-liver, tumour-to-spleen and tumour-to-bone ratios.
CONCLUSION: Since distant prostate cancer metastases are situated in bone or bone marrow, the higher tumour-to-bone ratio is the most important. This renders (111)In-DOTA-Z(HER2:S1) a preferable agent for imaging of HER2 expression in disseminated prostate cancer.

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