interleukin-8 and Liposarcoma--Myxoid

Inflammatory mediators present in the tumor milieu may promote cancer progression and are considered promising targets of novel biological therapies. We previously reported that the marine antitumor agent trabectedin, approved in Europe in 2007 for soft tissue sarcomas and in 2009 for ovarian cancer, was able to downmodulate the production of selected cytokines/chemokines in immune cells. Patients with myxoid liposarcoma (MLS), a subtype characterized by the expression of the oncogenic transcript FUS-CHOP, are highly responsive to trabectedin. The drug had marked antiproliferative effects on MLS cell lines at low nanomolar concentrations. We tested the hypothesis that trabectedin could also affect the inflammatory mediators produced by cancer cells. Here, we show that MLS express several cytokines, chemokines, and growth factors (CCL2, CCL3, CCL5, CXCL8, CXCL12, MIF, VEGF, SPARC) and the inflammatory and matrix-binder protein pentraxin 3 (PTX3), which build up a prominent inflammatory environment. In vitro treatment with noncytotoxic concentrations of trabectedin selectively inhibited the production of CCL2, CXCL8, IL-6, VEGF, and PTX3 by MLS primary tumor cultures and/or cell lines. A xenograft mouse model of human MLS showed marked reduction of CCL2, CXCL8, CD68+ infiltrating macrophages, CD31+ tumor vessels, and partial decrease of PTX3 after trabectedin treatment. Similar findings were observed in a patient tumor sample excised after several cycles of therapy, indicating that the results observed in vitro might have in vivo relevance. In conclusion, trabectedin has dual effects in liposarcoma: in addition to direct growth inhibition, it affects the tumor microenvironment by reducing the production of key inflammatory mediators.

Topics: Animals; Antigens, CD; Antigens, Differentiation, Myelomonocytic; Antineoplastic Agents, Alkylating; C-Reactive Protein; Cell Cycle; Cell Death; Cell Line, Tumor; Chemokine CCL2; Dioxoles; Humans; Immunohistochemistry; Inflammation Mediators; Interleukin-6; Interleukin-8; Liposarcoma, Myxoid; Macrophages; Mice; Serum Amyloid P-Component; Tetrahydroisoquinolines; Trabectedin; Vascular Endothelial Growth Factor A; Xenograft Model Antitumor Assays

FUS (also called TLS), EWSR1 and TAF15 (also called TAF2N) are related genes involved in tumor type-specific fusion oncogenes in human malignancies. The FUS-DDIT3 fusion oncogene results from a t(12;16)(q13;p11) chromosome translocation and has a causative role in the initiation of myxoid/round cell liposarcomas (MLS/RCLS). The FUS-DDIT3 protein induces increased expression of the CAAT/enhancer-binding protein (C/EBP) and nuclear factor-kappaB (NF-kappaB)-controlled gene IL8, and the N-terminal FUS part is required for this activation. Chromatin immunoprecipitation analysis showed that FUS-DDIT3 binds the IL8 promoter. Expression studies of the IL8 promoter harboring a C/EBP-NF-kappaB composite site pinpointed the importance of NF-kappaB for IL8 expression in FUS-DDIT3-expressing cells. We therefore probed for possible interaction of FUS-DDIT3 with members of the NF-kappaB family. The nuclear factor NFKBIZ colocalizes with FUS-DDIT3 in nuclear structures, and immunoprecipitation experiments showed that FUS-DDIT3 binds the C-terminal of NFKBIZ. We also report that additional NF-kappaB-controlled genes are upregulated at the mRNA level in FUS-DDIT3-expressing cell lines and they can be induced by NFKBIZ. Taken together, the results indicate that FUS-DDIT3 deregulates some NF-kappaB-controlled genes through interactions with NFKBIZ. Similar mechanisms may be a part of the transformation process in other tumor types carrying FUS, EWSR1 and TAF15 containing fusion oncogenes.

Topics: Acute-Phase Proteins; Adaptor Proteins, Signal Transducing; Binding Sites; CCAAT-Enhancer-Binding Proteins; Cell Line, Tumor; Cell Nucleus; Fibrosarcoma; Humans; I-kappa B Proteins; Interleukin-6; Interleukin-8; Lipocalin-2; Lipocalins; Liposarcoma, Myxoid; Neoplasm Proteins; NF-kappa B; Nuclear Proteins; Oncogene Proteins, Fusion; Promoter Regions, Genetic; Protein Binding; Protein Interaction Mapping; Proto-Oncogene Proteins; RNA-Binding Protein FUS; Transcription Factor CHOP; Transcription, Genetic