Plasma endothelial protein C receptor influences innate immune response in ovarian cancer by decreasing the population of natural killer and TH17 helper cells

EPCR deficiency ameliorates inflammatory arthritis in mice by suppressing the activation and migration of T cells and dendritic cells

OBJECTIVES

Endothelial protein C receptor (EPCR) is highly expressed in synovial tissues of patients with RA, but the function of this receptor remains unknown in RA. This study investigated the effect of EPCR on the onset and development of inflammatory arthritis and its underlying mechanisms.

METHODS

CIA was induced in EPCR gene knockout (KO) and matched wild-type (WT) mice. The onset and development of arthritis was monitored clinically and histologically. T cells, dendritic cells (DCs), EPCR and cytokines from EPCR KO and WT mice, RA patients and healthy controls (HCs) were detected by flow cytometry and ELISA.

RESULTS

EPCR KO mice displayed >40% lower arthritis incidence and 50% less disease severity than WT mice. EPCR KO mice also had significantly fewer Th1/Th17 cells in synovial tissues with more DCs in circulation. Lymph nodes and synovial CD4 T cells from EPCR KO mice expressed fewer chemokine receptors CXCR3, CXCR5 and CCR6 than WT mice. In vitro, EPCR KO spleen cells contained fewer Th1 and more Th2 and Th17 cells than WT and, in concordance, blocking EPCR in WT cells stimulated Th2 and Th17 cells. DCs generated from EPCR KO bone marrow were less mature and produced less MMP-9. Circulating T cells from RA patients expressed higher levels of EPCR than HC cells; blocking EPCR stimulated Th2 and Treg cells in vitro.

CONCLUSION

Deficiency of EPCR ameliorates arthritis in CIA via inhibition of the activation and migration of pathogenic Th cells and DCs. Targeting EPCR may constitute a novel strategy for future RA treatment.

Targeting the differentiation of gastric cancer cells (KATO‑III) downregulates epithelial‑mesenchymal and cancer stem cell markers

The aim of the present study was to analyze the acquisition of the differentiated phenotype in the human gastric signet ring cell adenoma cancer KATO-III cell line in vitro. The morphology of KATO-III cells was explored by microcinematography. Different cytokines secreted by both adherent and non-adherent KATO-III cells into medium were observed. The cancer stem cell phenotypes were identified by reverse transcription-quantitative polymerase chain reaction using primers (E-Cad, Slug, Snail, vimentin, NANOG, NESTIN, OCT3/4 and C-X-C motif chemokine receptor 4) or antibodies [cluster of differentiation (CD)90 and CD117] by flow cytometry (FACS). The influence of the induction media for the differentiation of mesenchymal cells was studied through viability and proliferation assays, by evaluating gene expression and the expression of markers via FACS. Cell viability and cell cycle distribution were evaluated following the treatment of KATO-III with acetyl salicylic acid and using the induction media as an inhibitor of epithelial-mesenchymal transition (EMT) and heparanase. A total of 3 phenotypes of KATO-III were observed (adherent, non-adherent and cell cluster), which have internal potential for cell transition into one of the other phenotypes. KATO-III was differentiated into adipocyte-, chondrocyte-, osteocyte- and neurocyte-like cells by the induction media. Identification of the induced cells was conducted using cell dyes. Reduced mRNA expression of EMT-associated molecules, stem cell markers and heparanase was observed with acetyl salicylic acid and induction media. An inhibitory effect of acetyl salicylic acid and the induction media was also noted in regard to cell proliferation. In addition, acetyl salicylic acid induced G0/G1 phase cell cycle arrest in KATO-III cells. In conclusion, the induction of the differentiation of cancer stem cells into non-proliferating cells offers the possibility for novel drug design to overcome the issues associated with metastasis, drug resistance and systemic toxicity with improved therapeutic efficacy.

Thrombopoietin Secretion by Human Ovarian Cancer Cells

The thrombopoietin (TPO) gene expression in human ovary and cancer cells from patients with ovarian carcinomatosis, as well as several cancer cell lines including MDA-MB231 (breast cancer), K562 and HL60 (Leukemic cells), OVCAR-3NIH and SKOV-3 (ovarian cancer), was performed using RT PCR, real-time PCR, and gene sequencing. Human liver tissues are used as controls. The presence of TPO in the cells and its regulation by activated protein C were explored by flow cytometry. TPO content of cell extract as well as plasma of a patient with ovarian cancer was evaluated by ELISA. The functionality of TPO was performed in coculture on the basis of the viability of a TPO-dependent cell line (Ba/F3), MTT assay, and Annexin-V labeling. As in liver, ovarian tissues and all cancer cells lines except the MDA-MB231 express the three TPO-1 (full length TPO), TPO-2 (12 bp deletion), and TPO-3 (116 pb deletion) variants. Primary ovarian cancer cells as well as cancer cell lines produce TPO. The thrombopoietin production by OVCAR-3 increased when cells are stimulated by aPC. OVCAR-3 cell's supernatant can replace exogenous TPO and inhibited TPO-dependent cell line (Ba/F3) apoptosis. The thrombopoietin produced by tumor may have a direct effect on thrombocytosis/thrombosis occurrence in patients with ovarian cancer.

High IL-17 expression is associated with an unfavorable prognosis in thyroid cancer

Previous studies have indicated that cancer may be promoted and/or exacerbated by inflammation and infection. The cytokines produced by activated innate immune cells that stimulate tumor growth and progression are considered as important components in this process. The interleukin (IL)-23/T helper (Th)17 axis, which exerts marked pro-inflammatory effects, has emerged as an important mediator in inflammation-associated cancer. Increasing clinical evidence indicates that Th17 may promote or inhibit tumor progression, however, the function of Th17 in the pathogenesis of benign and malignant thyroid neoplasms remains unclear. The present study investigated the association between the IL-23/Th17 axis and neoplastic and non-neoplastic thyroid lesions using immunohistochemistry. A total of 131 thyroid biopsy specimens were analyzed, which revealed high IL-17 and IL-23 expression in differentiated thyroid cancer and medullary thyroid cancer tissues when compared with benign lesions, including follicular thyroid adenoma and goiter tissues. Furthermore, high IL-17 expression was associated with recurrence and mortality. These results indicate that the IL-23/Th17 axis exhibits a pivotal function in the development of thyroid neoplasms.

Activated protein C upregulates ovarian cancer cell migration and promotes unclottability of the cancer cell microenvironment

The objective of this study was to evaluate the role of activated protein C (aPC), known to be a physiological anticoagulant, in ovarian cancer cell activation as well as in loss of clotting of cancer ascitic fluid. The effect of aPC on an ovarian cancer cell line (OVCAR-3) was tested in regards to i) cell migration and adhesion with the use of adhesion and wound healing assays as well as a droplet test; ii) protein phosphorylation, evaluated by cyto-ELISA; iii) cell cycle modification assessed by flow cytometric DNA quantification; and iv) anticoagulant activity evaluated by the prolongation of partial thromboplastin time (aPTT) of normal plasma in the presence or absence of aPC-treated ovarian cancer cells. In addition, the soluble endothelial protein C receptor (sEPCR) was quantified by ELISA in ascitic fluid of patients with ovarian cancer. Our results showed that in the OVCAR-3 aPC-induced cells i) an increase in cell migration was noted, which was inhibited when anti-endothelial protein C receptor (EPCR) was added to the culture medium and which may act via MEK-ERK and Rho-GTPase pathways; ii) an increase in threonine, and to a lesser extent tyrosine phosphorylation; iii) cell cycle activation (G1 to S/G2); and iv) a 2-3-fold prolongation of aPTT of normal plasma. In the peritoneal fluid, the sEPCR concentration was 71±23 ng/ml. In conclusion, free aPC binds to membrane EPCR in ovarian cancer cells and induces cell migration via MEK-ERK and Rho-GTPase pathways. This binding could also explain the loss of clotting of peritoneal fluids.

Culture models to define key mediators of cancer matrix remodeling

High grade serous epithelial ovarian cancer (HG-SOC) is one of the most devastating gynecological cancers affecting women worldwide, with a poor survival rate despite clinical treatment advances. HG-SOC commonly metastasizes within the peritoneal cavity, primarily to the mesothelial cells of the omentum, which regulate an extracellular matrix rich in collagens type I, III, and IV along with laminin, vitronectin, and fibronectin. Cancer cells depend on their ability to penetrate and invade secondary tissue sites to spread, however a detailed understanding of the molecular mechanisms underlying these processes remain largely unknown. Given the high metastatic potential of HG-SOC and the associated poor clinical outcome, it is extremely important to identify the pathways and the components of which that are responsible for the progression of this disease. In vitro methods of recapitulating human disease processes are the critical first step in such investigations. In this context, establishment of an in vitro “tumor-like” micro-environment, such as 3D culture, to study early disease and metastasis of human HG-SOC is an important and highly insightful method. In recent years, many such methods have been established to investigate the adhesion and invasion of human ovarian cancer cell lines. The aim of this review is to summarize recent developments in ovarian cancer culture systems and their use to investigate clinically relevant findings concerning the key players in driving human HG-SOC.