Inhibition of vascular adhesion protein-1 enhances the anti-tumor effects of immune checkpoint inhibitors.

Modulation of the immunosuppressive tumor microenvironment (TME) is essential for enhancing the anti-tumor effects of immune checkpoint inhibitors (ICIs). Adhesion molecules and enzymes such as vascular adhesion protein-1 (VAP-1), which are expressed in some cancers and tumor vascular endothelial cells, may be involved in the generation of an immunosuppressive TME. In this study, the role of VAP-1 in TME was investigated in 2 murine colon cancer models and human cancer cells. Intraperitoneal administration of the VAP-1-specific inhibitor U-V296 inhibited murine tumor growth by enhancing IFN-γ-producing tumor antigen-specific CD8+ T cells. U-V296 exhibited significant synergistic anti-tumor effects with ICIs. In the TME of mice treated with U-V296, the expression of genes associated with M2-like macrophages, Th2 cells (Il4, Retnla, and Irf4), angiogenesis (Pecam1), and fibrosis (Acta2, Loxl2) were significantly decreased, and the Th1/Th2 balance was increased. H2 O2 , an enzymatic product of VAP-1, which promoted the production of IL-4 by mouse Th2 and inhibited IFN-γ by mouse Th1 and human tumor-infiltrating lymphocytes, was decreased in tumors and CD31+ tumor vascular endothelial cells in the TMEs of mice treated with VAP-1 inhibitor. TCGA database analysis showed that VAP-1 expression was a negative prognostic factor in human cancers, exhibiting a significant positive correlation with IL-4, IL4R, and IL-13 expression and a negative correlation with IFN-γ expression. These results indicated that VAP-1 is involved in the immunosuppressive TMEs through H2 O2 -associated Th2/M2 conditions and may be an attractive target for the development of combination cancer immunotherapy with ICIs.

Role of Eosinophil Relative Count and Neutrophil-to-Lymphocyte Ratio in the Assessment of Severity of Atopic Dermatitis.

The aim of this study is to elucidate the relationship between 2 different types of severity-indicating parameters (i.e. between subjective and objective severity-indicating parametersin patients with atopic dermatitis. The disease severity of 55 patients with atopic dermatitis was assessed using 7 subjective parameters indicating severity, including visual analogue scale for itch, Patient-Oriented Eczema Measure, 5-D itch scale, Dermatology Life Quality Index, Eczema Area and Severity Index, body surface area, and Investigator Global Assessment, and 8 objective parameters indicating severity, including eosinophil relative count, neutrophil-to-lymphocyte ratio, lactate dehydrogenase, and thymus and activation-regulated chemokine. Five subjective parameters reflecting itch correlated significantly with eosinophil relative count, but not with neutrophil-to-lymphocyte ratio. In contrast, 2 subjective parameters, mainly reflecting the degree of inflammation and area of affected regions, correlated significantly with neutrophil-to-lymphocyte ratio. The eosinophil relative count may correlate with the degree of itch, while the neutrophil-to-lymphocyte ratio may correlate with the degree of inflammation and the area of the affected region. The eosinophil relative count and neutrophil-to-lymphocyte ratio may thus be stand-alone parameters from each other in the assessment of the severity of atopic dermatitis.

Phosphorylation of STAT1 serine 727 enhances platinum resistance in uterine serous carcinoma.

Uterine serous carcinoma (USC) is a highly aggressive histological subtype of endometrial cancers harboring highly metastatic and chemoresistant features. Our previous study showed that STAT1 is highly expressed in USC and acts as a key molecule that is positively correlated with tumor progression, but it remains unclear whether STAT1 is relevant to the malicious chemorefractory nature of USC. In the present study, we investigated the regulatory role of STAT1 toward platinum-cytotoxicity in USC. STAT1 suppression sensitized USC cells to increase cisplatin-mediated apoptosis (p < 0.001). Furthermore, phosphorylation of STAT1 was prominently observed on serine-727 (pSTAT1-Ser727), but not on tyrosine-701, in the nucleus of USC cells treated with cisplatin. Mechanistically, the inhibition of pSTAT1-Ser727 by dominant-negative plasmid elevated cisplatin-mediated apoptosis by increasing intracellular accumulation of cisplatin through upregulation of CTR1 expression. TBB has an inhibitory effect on casein kinase 2 (CK2), which phosphorylate STAT1 at serine residues. Sequential treatment with TBB and cisplatin on USC cells greatly reduced nuclear pSTAT1-Ser727, enhanced intracellular accumulation of cisplatin, and subsequently increased apoptosis. Tumor load was significantly reduced by combination therapy of TBB and cisplatin in in vivo xenograft models (p < 0.001). Our results collectively suggest that pSTAT1-Ser727 may play a key role in platinum resistance as well as tumor progression in USC. Thus, targeting the STAT1 pathway via CK2 inhibitor can be a novel method for attenuating the chemorefractory nature of USC.

The BMP signaling pathway leads to enhanced proliferation in serous ovarian cancer-A potential therapeutic target.

Members of the transforming growth factor-ß (TGF-ß) superfamily transduce signals via SMAD proteins. SMAD2 and SMAD3 mediate TGF-ß signaling, whereas SMAD1, SMAD5, and SMAD8/9 transduce bone morphogenetic protein (BMP) signals. We would like to identify the function of BMP/SMAD5 signaling in serous ovarian cancer. The protein levels of total SMAD5 and phosphorylated SMAD5 (pSMAD5) were examined by immunohistochemical analysis using clinical serous ovarian cancer samples. Following treatment with either recombinant BMP2 (rBMP2) or Dorsomorphin (DM), western blotting was performed to observe pSMAD5 protein in the cytoplasm and the nucleus, separately. Cell proliferation was detected in SMAD5 knockdown serous ovarian cancer cell lines cultured with DM or rBMP2. The impact of DM or rBMP2 on tumor growth was observed in a mouse model of serous ovarian cancer. An inverse correlation was observed between pSMAD5 levels in the nucleus and the prognosis of patients with serous ovarian cancer. The treatment of SK-OV-3 with rBMP2 stimulated pSMAD5 translocation from the cytoplasm to the nucleus, and the addition of DM inhibited this effect. The proliferation of ovarian cancer cell lines was enhanced by BMP2 and suppressed by DM via SMAD5 in vitro. In vitro and in vivo experiments clearly demonstrated BMP2-stimulated proliferation of serous ovarian cancer and inhibition of this effect by DM. Our data suggests that BMP/SMAD5 signaling plays an important role and, therefore, becomes a potential therapeutic target in serous ovarian cancer. © 2015 Wiley Periodicals, Inc.

Invasion of uterine cervical squamous cell carcinoma cells is facilitated by locoregional interaction with cancer-associated fibroblasts via activating transforming growth factor-beta.

OBJECTIVE: Local invasion is a common pattern of spread in uterine cervical squamous cell carcinoma (CSCC). Although transforming growth factor-beta (TGF-ß) facilitates invasion of various types of cancer cells, the role of the TGF-ß pathway in CSCC is unclear. In this study, we analyzed the role of TGF-ß signaling in the progression of CSCC. METHODS: Immunohistochemistry was used to examine the expression of TGF-ß pathway molecules in 67 CSCC samples with clinicopathological data. Activation of the TGF-ß pathway was investigated following co-culture of CSCC cells and cervical cancer-associated fibroblasts (CCAFs). RESULTS: Clinicopathological analysis of CSCC samples revealed that prominent expression of TGF-ß receptor-2 was more frequent in CSCC with lymphovascular space invasion (LVSI) than without LVSI (p < 0.01). Lymph node metastasis was more frequent in cases in which phosphorylated SMAD3 (pSMAD3) was localized exclusively at the boundary of tumor clusters (n = 9, p < 0.05). Recombinant TGF-ß1 increased pSMAD3 expression and enhanced cellular invasion (p < 0.005) in CSCC cells, which was attenuated by an inhibitor of the TGF-ß receptor (p < 0.005). Enhanced pSMAD3 expression and invasion was also observed when conditioned media from CSCC cells co-cultured with CCAFs were administered. Luciferase assays showed that this medium contained a large amount of active TGF-ß. Along with TGF-ß activation, thrombospondin-1 was upregulated in both CSCC cells and CCAFs, while thrombospondin-1 silencing in either CSCC cells or CCAFs repressed the activity of TGF-ß. Thrombospondin-1 was prominently expressed in cases with pSMAD3 boundary staining (p < 0.05). CONCLUSIONS: These results suggest that interaction between CSCC cells and surrounding CCAFs activates TGF-ß via thrombospondin-1 secretion to facilitate CSCC invasion.

Menstrual cyclic change of metastin/GPR54 in endometrium.

Metastin/kisspeptin is encoded by KISS1 and functions as an endogenous ligand of GPR54. Interaction of metastin with GPR54 suppresses metastasis and also regulates release of gonadotropin-releasing hormone, which promotes secretion of estradiol (E2) and progesterone (P4). We have previously demonstrated epigenetic regulation of GPR54 in endometrial cancer and the potent role of metastin peptides in inhibiting metastasis in endometrial cancer. However, little is known about how the metastin-GPR54 axis is regulated in the endometrium, the precursor tissue of endometrial cancer. Endometrial stromal cells (ESCs) and endometrial glandular cells (EGCs) within the endometrium show morphological changes when exposed to E2 and P4. In this study, we show that metastin expression is induced in ESCs through decidualization, but is repressed in glandular components of atypical endometrial hyperplasia (AEH) and endometrial cancer relative to EGCs. The promoter of GPR54 is unmethylated in normal endometrium and in AEH. These results indicate metastin may function in decidualized endometrium to prepare for adequate placentation but this autocrine secretion of metastin is deregulated during oncogenesis to enable tumor cells to spread.

Utilization of genomic signatures to identify high-efficacy candidate drugs for chemorefractory endometrial cancers.

Endometrial cancer, one of the most common gynecologic malignancies, is increasing in Japan, nearly doubling over the last decade. High-grade disease patients are often resistant to conventional chemotherapy with platinum agents; therefore, discovery of efficacious new drugs in this setting is required to benefit chemorefractory cases. The 50% growth-inhibitory (GI50) concentration of 27 clinically relevant drugs was measured in the NCI60 panel of cell lines. Gene expression data were analyzed using Bayesian binary regression, to first generate a response signature for each drug and then to calculate individual susceptibility scores using in vivo endometrial cancer data (GSE2109; http://www.ncbi.nlm.nih.gov/geo) and in vitro data (GSE25458), as well as to identify candidate drugs for chemorefractory cases. Using these candidates, cell proliferation, apoptosis and caspase assays were performed in vitro. The tumor growth-inhibitory effect of the candidate was also assessed in vivo using nude mice. Through microarray analysis, fludarabine and temsirolimus showed higher susceptibility scores in high-grade cases compared to cisplatin, doxorubicin and paclitaxel. Fludarabine significantly inhibited cell proliferation and increased apoptosis in the cisplatin-resistant endometrial cancer cell line, HEC1A, relative to HEC50B (p < 0.001). Fludarabine treatment also enhanced caspase-3/7 activity in HEC1A relative to HEC50B cells (p < 0.001), and inhibited the growth of HEC1A xenograft tumors relative to cisplatin (p < 0.05). These results support that identification and use of genomic signatures can lead to identification of new therapeutic candidates that may prove beneficial to chemoresistant cases. Fludarabine may be useful in targeting high-grade, chemorefractory endometrial cancer.

The effect of the type of dietary protein on the development of ovarian cancer.

We evaluated whether different dietary protein qualities (isocaloric diets involving animal (casein) or plant protein (soy protein) could inhibit the ovarian cancer growth in mice and improve their prognosis and whether chemotherapy had different tumor reducing effects on these mice. In the mice of the 20% plant protein group, the ovarian cancer growth at 5 weeks after tumor implantation was clearly reduced in comparison to the mice in the 20% animal protein group (p< 0.001). The serum levels of insulin and IGF-1 levels were both lower in the mice of the 20% plant protein group than in the mice of the 20% animal protein group (p<0.001 and p<0.01, respectively). Immunohistochemistry revealed that the level of eukaryotic initiation factor 4E-binding protein 1 (p-4EBP1) activity-one of the major downstream effectors of the mTOR pathway -of the plant protein group was significantly weaker than that of the animal protein group (p<0.001). The prognosis of the 20% plant protein group was better than that of the 20% animal protein group (log-rank test, p=0.0062). The ovarian cancer growth in the 20% plant protein plus cisplatin treatment group was not significantly reduced in comparison to the 20% animal protein plus cisplatin treatment group. Our findings suggest that a diet high in plant protein reduces the growth of human ovarian cancer cells in mice compared to a diet high in animal protein, -possibly through the lack of activation of the IGF/Akt/mTOR pathway, and leads to a better prognosis with or without cisplatin treatment.

Metabolic alterations caused by HNF1ß expression in ovarian clear cell carcinoma contribute to cell survival.

HNF1ß is expressed exclusively in ovarian clear cell carcinoma (OCCC) and not in other ovarian cancers, regarded as a hallmark of this tumor. This implies its central role in the unique character of OCCC, including resistance to chemotherapy, but its exact role and influence in cancer biology or the molecular bases of its function are largely unknown. Using comprehensive metabolome analysis of HNF1ß_shRNA-stable cell lines, we show here that HNF1ß drastically alters intracellular metabolism, especially in direction to enhance aerobic glycolysis, so called the "Warburg effect". The consequence of the metabolic change contributed cell survival under stresses such as hypoxia and chemo-reagent, only when sufficient glucose supply was available. Augmented cell survival was based on the reduced ROS activity derived from metabolic alteration such as shift from oxidative phosphorylation to glycolysis and increased intracellular anti-oxidant, glutathione (GSH). One of the cystine transporters, rBAT is likely to play a major role in this GSH increase. These data suggest that HNF1ß, possibly induced by stressful microenvironment in the endometriotic cyst, confers survival advantage to the epithelial cells, which leads to the occurrence of OCCC, a chemo-resistant phenotype of ovarian cancer.

STAT1 drives tumor progression in serous papillary endometrial cancer.

Recent studies of the interferon-induced transcription factor STAT1 have associated its dysregulation with poor prognosis in some cancers, but its mechanistic contributions are not well defined. In this study, we report that the STAT1 pathway is constitutively upregulated in type II endometrial cancers. STAT1 pathway alteration was especially prominent in serous papillary endometrial cancers (SPEC) that are refractive to therapy. Our results defined a "SPEC signature" as a molecular definition of its malignant features and poor prognosis. Specifically, we found that STAT1 regulated MYC as well as ICAM1, PD-L1, and SMAD7, as well as the capacity for proliferation, adhesion, migration, invasion, and in vivo tumorigenecity in cells with a high SPEC signature. Together, our results define STAT1 as a driver oncogene in SPEC that modulates disease progression. We propose that STAT1 functions as a prosurvival gene in SPEC, in a manner important to tumor progression, and that STAT1 may be a novel target for molecular therapy in this disease.

PD-L1 on tumor cells is induced in ascites and promotes peritoneal dissemination of ovarian cancer through CTL dysfunction.

PURPOSE: Ovarian cancer often progresses by disseminating to the peritoneal cavity, but how the tumor cells evade host immunity during this process is poorly understood. Programmed cell death 1 ligand 1 (PD-L1) is known to suppress immune system and to be expressed in cancer cells. The purpose of this study is to elucidate the function of PD-L1 in peritoneal dissemination. EXPERIMENTAL DESIGN: Ovarian cancer cases were studied by microarray and immunohistochemistry. PD-L1 expression in mouse ovarian cancer cell line in various conditions was assessed by flow cytometry. PD-L1-overexpression cell line and PD-L1-depleted cell line were generated, and cytolysis by CTLs was analyzed, and alterations in CTLs were studied by means of timelapse and microarray. These cell lines were injected intraperitoneally to syngeneic immunocompetent mice. RESULTS: Microarray and immunohistochemistry in human ovarian cancer revealed significant correlation between PD-L1 expression and peritoneal positive cytology. PD-L1 expression in mouse ovarian cancer cells was induced upon encountering lymphocytes in the course of peritoneal spread in vivo and coculture with lymphocytes in vitro. Tumor cell lysis by CTLs was attenuated when PD-L1 was overexpressed and promoted when it was silenced. PD-L1 overexpression inhibited gathering and degranulation of CTLs. Gene expression profile of CTLs caused by PD-L1-overexpressing ovarian cancer was associated with CTLs exhaustion. In mouse models, PD-L1 depletion resulted in inhibited tumor growth in the peritoneal cavity and prolonged survival. CONCLUSION: PD-L1 expression in tumor cell promotes peritoneal dissemination by repressing CTL function. PD-L1-targeted therapy is a promising strategy for preventing and treating peritoneal dissemination.

GPR54 is a target for suppression of metastasis in endometrial cancer.

Invasion into deep myometrium and/or lymphovascular space is a well-known risk factor for endometrial cancer metastasis, resulting in poor prognosis. It is therefore clinically important to identify novel molecules that suppress tumor invasion. Reduced expression of the metastasis suppressor, kisspeptin (KISS1), and its endogenous receptor, GPR54, has been reported in several cancers, but the significance of the KISS1/GPR54 axis in endometrial cancer metastasis has not been clarified. Metastin-10 is the minimal bioactive sequence of genetic products of KISS1. Clinicopathological analysis of 92 endometrial cancers revealed overall survival is improved in cancers with high expression of GPR54 (P < 0.05) and that GPR54 expression is associated with known prognostic factors including FIGO stage, grade, and deep myometrial invasion. Through RNAi and microarray analyses, metastin-10 was predicted to suppress metastasis of GPR54-expressing endometrial cancers in vivo. Methylation analysis revealed GPR54 is epigenetically regulated. Metastin-GPR54 axis function was restored following treatment with the DNA hypomethylating agent 5-aza-DC. These data suggest that metastin-10 may be effective at inhibiting the metastatic spread of endometrial cancers in combination with demethylating agents to induce GPR54 expression.