ABSTRACT
BACKGROUND: Gastroenteropancreatic neuroendocrine carcinomas (GEP-NECs) are biologically aggressive tumors, associated with a very poor survival. Due to their rarity, our knowledge on GEP-NEC biology is very limited. The aim of this study was to establish a GEP-NEC cell line model that might contribute to a better understanding of this rare malignant disease to further develop novel therapeutic approaches in preclinical studies. METHODS: Small cell neuroendocrine cancer cell line NEC-DUE3 was derived from a lymph node metastasis of a neuroendocrine carcinoma (NEC) located at the anal canal. Morphological characteristics and the expression of neuroendocrine markers were comprehensively investigated. For genetic profiling, NEC-DUE3 cells were analyzed by DNA fingerprinting. Chromosomal aberrations were mapped by array comparative genomic hybridization. NEC-DUE3 cell tumorigenicity was evaluated in vivo and the sensitivity to chemotherapeutic agents was assessed in vitro. RESULTS: NEC-DUE3 cells were characterized by the expression of molecular markers that are commonly observed in GEP-NECs, were sensitive to treatment with cisplatin, and able to form tumors in immunodeficient mice. CONCLUSION: We established and characterized the first small cell GEP-NEC cell line that may serve as a valuable tool to create a better understanding of the biology of these rare tumors and to develop novel treatment strategies.
Subject(s)
Anal Canal/pathology , Anus Neoplasms/pathology , Carcinoma, Neuroendocrine/pathology , Cell Line, Tumor , Female , HumansABSTRACT
Follicular thyroid cancer's (FTC) excellent long-term prognosis is mainly dependent on postoperative radioactive iodine (RAI) treatment. However, once the tumour becomes refractory, the 10-year disease-specific survival rate drops below 10%. The aim of our study was to evaluate the prognostic and biological role of the TRAIL system in FTC and to elucidate the influence of small-molecule-mediated antagonisation of inhibitor of apoptosis proteins (IAPs) on TRAIL sensitivity in vitro Tissue microarrays were constructed from forty-four patients with histologically confirmed FTC. Expression levels of TRAIL and its receptors were correlated with clinicopathological data and overall as well as recurrence-free survival. Non-iodine-retaining FTC cell lines TT2609-bib2 and FTC133 were treated with recombinant human TRAIL alone and in combination with Smac mimetics GDC-0152 or Birinapant. TRAIL-R2/DR5 as well as TRAIL-R3/DcR1 and TRAIL-R4/DcR2 were significantly higher expressed in advanced tumour stages. Both decoy receptors were negatively associated with recurrence-free and overall survival. TRAIL-R4/DcR2 additionally proved to be an independent negative prognostic marker in FTC (HR = 1.446, 95% CI: 1.144-1.826; P < 0.001). In vitro, the co-incubation of Birinapant or GDC-0152 with rh-TRAIL-sensitised FTC cell lines for TRAIL-induced apoptosis, through degradation of cIAP1/2. The TRAIL system plays an important role in FTC tumour biology. Its decoy receptors are associated with poor prognosis as well as earlier recurrence. The specific degradation of cIAP1/2 sensitises FTC cells to TRAIL-induced apoptosis and might highlight a new point of attack in patients with RAI refractory disease.
Subject(s)
Adenocarcinoma, Follicular/metabolism , Inhibitor of Apoptosis Proteins/metabolism , Receptors, TNF-Related Apoptosis-Inducing Ligand/metabolism , TNF-Related Apoptosis-Inducing Ligand/metabolism , Thyroid Neoplasms/metabolism , Adolescent , Adult , Aged , Aged, 80 and over , Apoptosis , Cell Line, Tumor , Female , Humans , Male , Middle Aged , Young AdultABSTRACT
Follicular thyroid carcinoma's (FTC) overall good prognosis deteriorates if the tumour fails to retain radioactive iodine. Therefore, new druggable targets are in high demand for this subset of patients. Here, we investigated the prognostic and biological role of survivin and XIAP in FTC. Survivin and XIAP expression was investigated in 44 FTC and corresponding non-neoplastic thyroid specimens using tissue microarrays. Inhibition of both inhibitor of apoptosis proteins (IAP) was induced by shRNAs or specific small molecule antagonists and functional changes were investigated in vitro and in vivo. Survivin and XIAP were solely expressed in FTC tissue. Survivin expression correlated with an advanced tumour stage and recurrent disease. In addition, survivin proved to be an independent negative prognostic marker. Survivin or XIAP knockdown caused a significant reduction in cell viability and proliferation, activated caspase3/7 and was associated with a reduced tumour growth in vivo. IAP-targeting compounds induced a decrease of cell viability, proliferation and cell cycle activity accompanied by an increase in apoptosis. Additionally, YM155 a small molecule inhibitor of survivin expression significantly inhibited tumour growth in vivo. Both IAPs demonstrate significant functional implications in the oncogenesis of FTCs and thus prove to be viable targets in patients with advanced FTC.
Subject(s)
Adenocarcinoma, Follicular/metabolism , Biomarkers, Tumor , Survivin/metabolism , Thyroid Neoplasms/metabolism , X-Linked Inhibitor of Apoptosis Protein/metabolism , Adenocarcinoma, Follicular/genetics , Adenocarcinoma, Follicular/mortality , Adenocarcinoma, Follicular/pathology , Animals , Cell Line, Tumor , Cell Survival , Disease Models, Animal , Female , Gene Expression , Gene Knockout Techniques , Humans , Imidazoles/pharmacology , Immunohistochemistry , Male , Mice , Naphthoquinones/pharmacology , Neoplasm Staging , Prognosis , Survivin/antagonists & inhibitors , Survivin/genetics , Thyroid Neoplasms/genetics , Thyroid Neoplasms/mortality , Thyroid Neoplasms/pathology , X-Linked Inhibitor of Apoptosis Protein/genetics , Xenograft Model Antitumor AssaysABSTRACT
Gastroenteropancreatic neuroendocrine neoplasms (GEP-NEN) represent a rare and heterogenous tumor entity. Importantly, the highly proliferative subgroup of neuroendocrine carcinoma (GEP-NEC) is characterized by high resistance to conventional chemotherapy. Consequently, there is an urgent need to identify novel therapeutic targets, especially for GEP-NEC. Thus, we focused on Inhibitor of apoptosis protein (IAP) family members survivin and XIAP that orchestrate inhibition of apoptosis, induce resistance against chemotherapeutics and facilitate tumor metastasis. Copy number gains (CNGs) could be detected by microarray comparative genomic hybridization for survivin and XIAP in 60 % and 26.7 % of all GEP-NENs, respectively. Immunohistochemical staining of tissue specimens from 77 consecutive patients with GEP-NEN demonstrated increased survivin protein expression levels in tissue specimens of highly proliferative GEP-NEC or GEP-NEN located in the stomach and colon. In contrast, XIAP overexpression was associated with advanced tumor stages. Knockdown of survivin and XIAP markedly reduced cell proliferation and tumor growth. In vitro, YM155 induced apoptotic cell death accompanied by a reduction in cell proliferation and inhibited GEP-NEC xenograft growth. Taken together, our data provide evidence for a biological relevance of these IAPs in GEP-NEN and support a potential role of survivin as therapeutic target especially in the subgroup of aggressive GEP-NEC.
