Constitutive production of inflammatory cytokines is a characteristic of many human malignant cell lines; however, the in vitro and in vivo interdependence of these cytokines, and their significance to the human cancer microenvironment, are both poorly understood. Here, we describe for the first time how three key cytokine/chemokine mediators of cancer-related inflammation, TNF, CXCL12, and interleukin 6, are involved in an autocrine cytokine network, the “TNF network,” in human ovarian cancer. We show that this network has paracrine actions on angiogenesis, infiltration of myeloid cells, and NOTCH signaling in both murine xenografts and human ovarian tumor biopsies. Neutralizing antibodies or siRNA to individual members of this TNF network reduced angiogenesis, myeloid cell infiltration, and experimental peritoneal ovarian tumor growth. The dependency of network genes on TNF was shown by their downregulation in tumor cells from patients with advanced ovarian cancer following the infusion of anti-TNF antibodies. Together, the findings define a network of inflammatory cytokine interactions that are crucial to tumor growth and validate this network as a key therapeutic target in ovarian cancer. Cancer Res; 72(1); 66–75. ©2011 AACR.

Emerging evidence shows that the efficacy of chemotherapeutic drugs is reliant on their capability to induce immunogenic cell death (ICD), thus transforming dying tumor cells into antitumor vaccines. We wanted to uncover potential therapeutic strategies that target ovarian cancer by having a better understanding of the standard-of-care chemotherapy treatment. Here, we showed in ovarian cancer that paclitaxel induced ICD-associated damage-associated molecular patterns (DAMP, such as CALR exposure, ATP secretion, and HMGB1 release) in vitro and elicited significant antitumor responses in tumor vaccination assays in vivo. Paclitaxel-induced TLR4 signaling was essential to the release of DAMPs, which led to the activation of NF-κB–mediated CCL2 transcription and IkappaB kinase 2–mediated SNARE-dependent vesicle exocytosis, thus exposing CALR on the cell surface. Paclitaxel induced endoplasmic reticulum stress, which triggered protein kinase R–like ER kinase activation and eukaryotic translation initiation factor 2α phosphorylation independent of TLR4. Paclitaxel chemotherapy induced T-cell infiltration in ovarian tumors of the responsive patients; CALR expression in primary ovarian tumors also correlated with patients' survival and patient response to chemotherapy. These findings suggest that the effectiveness of paclitaxel relied upon the activation of antitumor immunity through ICD via TLR4 and highlighted the importance of CALR expression in cancer cells as an indicator of response to paclitaxel chemotherapy in ovarian cancer.

MicroRNAs (miRNAs) regulate mRNA stability and protein expression, and certain miRNAs have been demonstrated to act either as oncogenes or tumor suppressors. Differential miRNA expression signatures have been documented in many human cancers but the role of miRNAs in endometrioid endometrial cancer (EEC) remains poorly understood. This study identifies significantly dysregulated miRNAs of EEC cells, and characterizes their impact on the malignant phenotype. We studied the expression of 365 human miRNAs using Taqman low density arrays in EECs and normal endometriums. Candidate differentially expressed miRNAs were validated by quantitative real‐time PCR. Expression of highly dysregulated miRNAs was examined in vitro through the effect of anti‐/pre‐miRNA transfection on the malignant phenotype. We identified 16 significantly dysregulated miRNAs in EEC and 7 of these are novel findings with respect to EEC. Antagonizing the function of miR‐7, miR‐194 and miR‐449b, or overexpressing miR‐204, repressed migration, invasion and extracellular matrix‐adhesion in HEC1A endometrial cancer cells. FOXC1 was determined as a target gene of miR‐204, and two binding sites in the 3′‐untranslated region were validated by dual luciferase reporter assay. FOXC1 expression was inversely related to miR‐204 expression in EEC. Functional analysis revealed the involvement of FOXC1 in migration and invasion of HEC1A cells. Our results present dysfunctional miRNAs in endometrial cancer and identify a crucial role for miR‐204‐FOXC1 interaction in endometrial cancer progression. This miRNA signature offers a potential biomarker for predicting EEC outcomes, and targeting of these cancer progression‐ and metastasis‐related miRNAs offers a novel potential therapeutic strategy for the disease.

ELF3 is a negative regulator of epithelial-mesenchymal transition in ovarian cancer cells ELF3 is a negative regulator of epithelial-mesenchymal transition in ovarian cancer cells