TY - JOUR
T1 - TrkC signaling is activated in adenoid cystic carcinoma and requires NT-3 to stimulate invasive behavior
AU - Ivanov, S. V.
AU - Panaccione, A.
AU - Brown, B.
AU - Guo, Y.
AU - Moskaluk, C. A.
AU - Wick, M. J.
AU - Brown, J. L.
AU - Ivanova, A. V.
AU - Issaeva, N.
AU - El-Naggar, A. K.
AU - Yarbrough, W. G.
N1 - Funding Information:
This study was supported by funds from the Adenoid Cystic Carcinoma Research Foundation to SI and WGY and by the NIH Challenge Grant 5RC1DE020332-02 from the National Institute of Dental and Craniofacial Research to WGY. This work was also supported in part by the Vanderbilt Ingram Cancer Center, the Vanderbilt Bill Wilkerson Center for Otolaryngology and Communication Sciences, the Robert J Kleberg Jr and Helen C Kleberg Foundation, and by an endowment to the Barry Baker Laboratory for Head and Neck Oncology.
PY - 2013/8/8
Y1 - 2013/8/8
N2 - Treatment options for adenoid cystic carcinoma (ACC) of the salivary gland, a slowly growing tumor with propensity for neuroinvasion and late recurrence, are limited to surgery and radiotherapy. Based on expression analysis performed on clinical specimens of salivary cancers, we identified in ACC expression of the neurotrophin-3 receptor TrkC/NTRK3, neural crest marker SOX10, and other neurologic genes. Here, we characterize TrkC as a novel ACC marker, which was highly expressed in 17 out of 18 ACC primary-tumor specimens, but not in mucoepidermoid salivary carcinomas or head and neck squamous cell carcinoma. Expression of the TrkC ligand NT-3 and Tyr-phosphorylation of TrkC detected in our study suggested the existence of an autocrine signaling loop in ACC with potential therapeutic significance. NT-3 stimulation of U2OS cells with ectopic TrkC expression triggered TrkC phosphorylation and resulted in Ras, Erk 1/2 and Akt activation, as well as VEGFR1 phosphorylation. Without NT-3, TrkC remained unphosphorylated, stimulated accumulation of phospho-p53 and had opposite effects on p-Akt and p-Erk 1/2. NT-3 promoted motility, migration, invasion, soft-agar colony growth and cytoskeleton restructuring in TrkC-expressing U2OS cells. Immunohistochemical analysis demonstrated that TrkC-positive ACC specimens also show high expression of Bcl2, a Trk target regulated via Erk 1/2, in agreement with activation of the TrkC pathway in real tumors. In normal salivary gland tissue, both TrkC and Bcl2 were expressed in myoepithelial cells, suggesting a principal role for this cell lineage in the ACC origin and progression. Sub-micromolar concentrations of a novel potent Trk inhibitor AZD7451 completely blocked TrkC activation and associated tumorigenic behaviors. Pre-clinical studies on ACC tumors engrafted in mice showed efficacy and low toxicity of AZD7451, validating our in vitro data and stimulating more research into its clinical application. In summary, we describe in ACC a previously unrecognized pro-survival neurotrophin signaling pathway and link it with cancer progression.
AB - Treatment options for adenoid cystic carcinoma (ACC) of the salivary gland, a slowly growing tumor with propensity for neuroinvasion and late recurrence, are limited to surgery and radiotherapy. Based on expression analysis performed on clinical specimens of salivary cancers, we identified in ACC expression of the neurotrophin-3 receptor TrkC/NTRK3, neural crest marker SOX10, and other neurologic genes. Here, we characterize TrkC as a novel ACC marker, which was highly expressed in 17 out of 18 ACC primary-tumor specimens, but not in mucoepidermoid salivary carcinomas or head and neck squamous cell carcinoma. Expression of the TrkC ligand NT-3 and Tyr-phosphorylation of TrkC detected in our study suggested the existence of an autocrine signaling loop in ACC with potential therapeutic significance. NT-3 stimulation of U2OS cells with ectopic TrkC expression triggered TrkC phosphorylation and resulted in Ras, Erk 1/2 and Akt activation, as well as VEGFR1 phosphorylation. Without NT-3, TrkC remained unphosphorylated, stimulated accumulation of phospho-p53 and had opposite effects on p-Akt and p-Erk 1/2. NT-3 promoted motility, migration, invasion, soft-agar colony growth and cytoskeleton restructuring in TrkC-expressing U2OS cells. Immunohistochemical analysis demonstrated that TrkC-positive ACC specimens also show high expression of Bcl2, a Trk target regulated via Erk 1/2, in agreement with activation of the TrkC pathway in real tumors. In normal salivary gland tissue, both TrkC and Bcl2 were expressed in myoepithelial cells, suggesting a principal role for this cell lineage in the ACC origin and progression. Sub-micromolar concentrations of a novel potent Trk inhibitor AZD7451 completely blocked TrkC activation and associated tumorigenic behaviors. Pre-clinical studies on ACC tumors engrafted in mice showed efficacy and low toxicity of AZD7451, validating our in vitro data and stimulating more research into its clinical application. In summary, we describe in ACC a previously unrecognized pro-survival neurotrophin signaling pathway and link it with cancer progression.
KW - Bcl2
KW - TrkC
KW - invasion
KW - migration
KW - neurotrophin-3
KW - salivary adenoid cystic carcinoma
UR - http://www.scopus.com/inward/record.url?scp=84881474156&partnerID=8YFLogxK
U2 - 10.1038/onc.2012.377
DO - 10.1038/onc.2012.377
M3 - Article
C2 - 23027130
AN - SCOPUS:84881474156
SN - 0950-9232
VL - 32
SP - 3698
EP - 3710
JO - Oncogene
JF - Oncogene
IS - 32
ER -