Immunity and immune suppression in human ovarian cancer

A Syngeneic Mouse Model of Epithelial Ovarian Cancer Port Site Metastases

Epithelial ovarian cancer (EOC) is a deadly gynecologic malignancy, but animal models for the study of EOC pathophysiology and drug efficacy are limited. Based on the finding that women with EOC are at risk for metastasis at a trocar site after laparoscopy, we developed a syngeneic murine model of port-site metastasis of EOC. We leveraged the ID8 murine EOC cell line to induce intra-peritoneal tumors in mice. Once durable intraperitoneal tumor was confirmed with bioluminescence imaging, intra-abdominal wall tumors were induced by abdominal wall puncture with a hollow bore needle. This resulted in a robust system in which C57BL/6 mice developed metastatic deposits at a rate of 66.7% ± 10.77; no intra-abdominal wall metastases were seen in control samples (P = .0003, CI 41.16–90.84). Immunodeficient NOD SCID gamma mice developed puncture site metastases in 70% ± 10.0 of mice and also had no metastases documented in control sites (P = .002, CI 42.24–97.76). In addition we were able to demonstrate the presence of immune infiltrates within the metastatic deposits of C57BL/6 mice via IHC. Therefore, in this study we demonstrate the predictable development of invasive abdominal wall metastases in a syngeneic mouse model of EOC. This model enables studies of the metastatic process and provides a novel system in which to test the effect of therapies on a clinically-relevant model in an immune competent mouse.

Role of tumor microenvironment in the pathobiology of ovarian cancer: Insights and therapeutic opportunities

Ovarian cancer is the fifth most common cancer affecting women and at present, stands as the most lethal gynecologic malignancy. The poor disease outcome is due to the nonspecific symptoms and the lack of effective treatment at advanced stages. Thus, it is of utmost importance to understand ovarian carcinoma through several lenses and to dissect the role that the unique peritoneal tumor microenvironment plays in ovarian cancer progression and metastasis. This review seeks to highlight several determinants of this unique tumor microenvironment, their influence on disease outcome and ongoing clinical trials targeting these determinants.

One-Carbon Metabolism: Biological Players in Epithelial Ovarian Cancer

Metabolism is deeply involved in cell behavior and homeostasis maintenance, with metabolites acting as molecular intermediates to modulate cellular functions. In particular, one-carbon metabolism is a key biochemical pathway necessary to provide carbon units required for critical processes, including nucleotide biosynthesis, epigenetic methylation, and cell redox-status regulation. It is, therefore, not surprising that alterations in this pathway may acquire fundamental importance in cancer onset and progression. Two of the major actors in one-carbon metabolism, folate and choline, play a key role in the pathobiology of epithelial ovarian cancer (EOC), the deadliest gynecological malignancy. EOC is characterized by a cholinic phenotype sustained via increased activity of choline kinase alpha, and via membrane overexpression of the alpha isoform of the folate receptor (FRα), both of which are known to contribute to generating regulatory signals that support EOC cell aggressiveness and proliferation. Here, we describe in detail the main biological processes associated with one-carbon metabolism, and the current knowledge about its role in EOC. Moreover, since the cholinic phenotype and FRα overexpression are unique properties of tumor cells, but not of normal cells, they can be considered attractive targets for the development of therapeutic approaches.

Role of tumor microenvironment in ovarian cancer pathobiology

Ovarian cancer is the fifth most common cancer affecting the female population and at present, stands as the most lethal gynecologic malignancy. Poor prognosis and low five-year survival rate are attributed to nonspecific symptoms and below par diagnostic criteria at early phases along with a lack of effective treatment at advanced stages. It is thus of utmost importance to understand ovarian carcinoma through several lenses including its molecular pathogenesis, epidemiology, histological subtypes, hereditary factors, diagnostic approaches and methods of treatment. Above all, it is crucial to dissect the role that the unique peritoneal tumor microenvironment plays in ovarian cancer progression and metastasis. This review seeks to highlight several important aspects of ovarian cancer pathobiology as a means to provide the necessary background to approach ovarian malignancies in the future.

High numbers of myeloid derived suppressor cells in peripheral blood and ascitic fluid of cirrhotic and HCC patients

BACKGROUND

Hepatocellular carcinoma (HCC) is the 3rd most common cause of cancer-related death worldwide. It has evolved different immune escape mechanisms, which might include emergence of lymphoid and myeloid regulatory cells. Aim of this work: To determine the numbers of Myeloid-derived suppressor cells (MDSCs) in peripheral blood and ascitic fluid in cirrhosis and HCC and their relation to IFN-γ and α-fetoprotein (α-FP).

PATIENTS AND METHODS

Sixty individuals were enrolled in this study; forty cirrhotic patients with ascites; twenty without HCC (Group I), and twenty with HCC (group II) as well as twenty healthy individuals as a control group (group III). The phenotype and numbers of MDSCs were analyzed in peripheral blood of all the individuals and ascitic fluid of the patients using flow cytometry. Intracellular IFN-γ and serum alfa-fetoprotein were measured.

RESULTS

Significant increases in the relative and the mean number of peripheral blood MDSCs were found in the cirrhosis and HCC groups than in the control group, with the HCC group showing the highest number. MDSC count was negatively correlated with IFN-γ levels, while α-FP was positively correlated with MDSC% in the HCC group. MDSC count was low in ascitic fluid of both HCC and cirrhosis groups with no significant difference between the 2 groups.

CONCLUSION

A high frequency of MDSCs was detected in the peripheral blood of cirrhotic and HCC patients, indicating presence of immunosuppressive arms. These cells could be targeted to develop a new effective immunotherapy or an adjuvant to current therapies.

Different Lipid Regulation in Ovarian Cancer: Inhibition of the Immune System

Lipid metabolism is altered in several cancer settings leading to different ratios of intermediates. Ovarian cancer is the most lethal gynecological malignancy. Cancer cells disperse in the abdominal space and ascites occurs. T cells obtained from ascites are unable to proliferate after an antigenic stimulus. The proliferation of ascites-derived T cells can be restored after culturing the cells for ten days in normal culture medium. No pathway aberrancies were detected. The acellular fraction of ascites can inhibit the proliferation of autologous as well as allogeneic peripheral blood lymphocytes, indicating the presence of soluble factors that interfere with T cell functionality. Therefore, we analyzed 109 lipid mediators and found differentially regulated lipids in suppressive ascitic fluid compared to normal abdominal fluid. Our study indicates the presence of lipid intermediates in ascites of ovarian cancer patients, which coincidences with T cell dysfunctionality. Since the immune system in the abdominal cavity is compromised, this may explain the high seeding efficiency of disseminated tumor cells. Further research is needed to fully understand the correlation between the various lipids and T cell proliferation, which could lead to new treatment options.

TGF-β1 contributes to CD8+ Treg induction through p38 MAPK signaling in ovarian cancer microenvironment

CD8⁺ regulatory T cells (Tregs) contribute to cancer progression and immune evasion. We previously reported that CD8⁺ Tregs could be induced in vitro by co-culture of CD8⁺ T cells with the OC cell lines SKOV3/A2780. Here, we described the role of TGF-β1 in CD8⁺ Treg induction by the OC microenvironment. OC patients expressed high levels of TGF-β1, as did the co-culture supernatant from CD8⁺ T cells and SKOV3. Additionally, TGF-β1 levels were positively correlated with CD8⁺ Treg percentages in OC. Neutralization experiments, cytokine studies and proliferation assays revealed that the in vitro-induced CD8⁺Tregs depended at least partially on up-regulated expression of TGF-β1 to exert their suppressive function. CD8⁺ T cells cultured with SKOV3 exhibited marked activation of p38 MAPK than CD8⁺ T cells cultured alone, which could be inhibited by TGF-β1-neutralizing antibody. Moreover, the p38 specific inhibitor SB203580 dose-dependently blocked the TGF-β1 activated conversion of CD8⁺ T cells into CD8⁺ Tregs. These data suggested that in vitro-induction of CD8⁺ Tregs depended in part on TGF-β1 activation of p38 MAPK signaling. Therefore, p38 MAPK could be a therapeutic target in OC anti-tumor immunotherapy.

Epigenetic therapy activates type I interferon signaling in murine ovarian cancer to reduce immunosuppression and tumor burden

Ovarian cancer is the most lethal of all gynecological cancers, and there is an urgent unmet need to develop new therapies. Epithelial ovarian cancer (EOC) is characterized by an immune suppressive microenvironment, and response of ovarian cancers to immune therapies has thus far been disappointing. We now find, in a mouse model of EOC, that clinically relevant doses of DNA methyltransferase and histone deacetylase inhibitors (DNMTi and HDACi, respectively) reduce the immune suppressive microenvironment through type I IFN signaling and improve response to immune checkpoint therapy. These data indicate that the type I IFN response is required for effective in vivo antitumorigenic actions of the DNMTi 5-azacytidine (AZA). Through type I IFN signaling, AZA increases the numbers of CD45⁺ immune cells and the percentage of active CD8⁺ T and natural killer (NK) cells in the tumor microenvironment, while reducing tumor burden and extending survival. AZA also increases viral defense gene expression in both tumor and immune cells, and reduces the percentage of macrophages and myeloid-derived suppressor cells in the tumor microenvironment. The addition of an HDACi to AZA enhances the modulation of the immune microenvironment, specifically increasing T and NK cell activation and reducing macrophages over AZA treatment alone, while further increasing the survival of the mice. Finally, a triple combination of DNMTi/HDACi plus the immune checkpoint inhibitor α-PD-1 provides the best antitumor effect and longest overall survival, and may be an attractive candidate for future clinical trials in ovarian cancer.

Immune checkpoints, their control by immunotherapy and ovarian cancer

Immune checkpoints are new targets for manipulation of immunological control over malignant tumors. They provide an important means to manage especially recurrent and refractory cancers and those cancers where there is an unmet need such as recurrent melanoma, renal cell carcinoma and recurrent ovarian cancer. As a new development this subject is experiencing rapid progress and multiple avenues are opening up. However, there are many hurdles to overcome, requiring constant updating, especially for students of ovarian cancer, who are looking at it with much hope.

Cytokines in immunogenic cell death: Applications for cancer immunotherapy

Despite advances in treatments like chemotherapy and radiotherapy, metastatic cancer remains a leading cause of death for cancer patients. While many chemotherapeutic agents can efficiently eliminate cancer cells, long-term protection against cancer is not achieved and many patients experience cancer recurrence. Mobilizing and stimulating the immune system against tumor cells is one of the most effective ways to protect against cancers that recur and/or metastasize. Activated tumor specific cytotoxic T lymphocytes (CTLs) can seek out and destroy metastatic tumor cells and reduce tumor lesions. Natural Killer (NK) cells are a front-line defense against drug-resistant tumors and can provide tumoricidal activity to enhance tumor immune surveillance. Cytokines like IFN-γ or TNF play a crucial role in creating an immunogenic microenvironment and therefore are key players in the fight against metastatic cancer. To this end, a group of anthracyclines or treatments like photodynamic therapy (PDT) exert their effects on cancer cells in a manner that activates the immune system. This process, known as immunogenic cell death (ICD), is characterized by the release of membrane-bound and soluble factors that boost the function of immune cells. This review will explore different types of ICD inducers, some in clinical trials, to demonstrate that optimizing the cytokine response brought about by treatments with ICD-inducing agents is central to promoting anti-cancer immunity that provides long-lasting protection against disease recurrence and metastasis.

Immune Cell Population in Ovarian Tumor Microenvironment

Ovarian cancer, the third most common with highest mortality rates gynecological malignancy among women in China, is characterized by a unique tumor immune microenvironment. Immune-cell population infiltrated into the tumor tissue among patients with ovarian cancer are associated positively or negatively with antitumor activity. The imbalance between immune activation and immune suppression can result in oncogenesis and cancer progression. Therefore, intense investigation of the immunologic mechanism of ovarian cancer is urgently needed, and a comprehensive understanding of the network in which immune cells interact with the microenvironment, tumor cells and each other will greatly promote the development of more effective immunotherapies for ovarian cancer. In this review, we will focus on the main immune-cell population in ovarian tumor microenvironment, discuss their role in tumor progression and try to give the readers a new perspective in finding more promising therapeutic targets for cancers.

Target Therapies for Uterine Carcinosarcomas: Current Evidence and Future Perspectives

Carcinosarcomas (CS) in gynecology are very infrequent and represent only 2-5% of uterine cancers. Despite surgical cytoreduction and subsequent chemotherapy being the primary treatment for uterine CS, the overall five-year survival rate is 30 ± 9% and recurrence is extremely common (50-80%). Due to the poor prognosis of CS, new strategies have been developed in the last few decades, targeting known dysfunctional molecular pathways for immunotherapy. In this paper, we aimed to gather the available evidence on the latest therapies for the treatment of CS. We performed a systematic review using the terms "uterine carcinosarcoma", "uterine Malignant Mixed Müllerian Tumors", "target therapies", "angiogenesis therapy", "cancer stem cell therapy", "prognostic biomarker", and "novel antibody-drug". Based on our results, the differential expression and accessibility of epithelial cell adhesion molecule-1 on metastatic/chemotherapy-resistant CS cells in comparison to normal tissues and Human Epidermal Growth Factor Receptor 2 (HER2) open up new possibilities in the field of target therapy. Nevertheless, future investigations are needed to clarify the impact of these new therapies on survival rate and medium-/long-term outcomes.

Immune Checkpoint Blockers and Ovarian Cancer

Although the idea, called "cancer immunotherapy," is very appealing and has previously been shown to work in several mouse models of cancer, it has in general been very difficult to translate cancer immunotherapy approaches to humans. Because of this frustration, by the 1990s, many scientists and biotechnology companies had given up on the idea of cancer immunotherapy. After few years, first detection T-cell suppression of effect of cytotoxic T-lymphocyte antigen-4 (CTLA4) molecule was established. Antibody (Ab) to CTLA4 could increase T-cell starting a completely new age of tumor immunology. Immune checkpoints are new ways in manipulation of immunological control over malignant tumors. It has lent an important measure to manage, especially recurrent and refractory cancers and those cancer where there is an unmet need like recurrent melanoma, renal cell carcinoma, and recurrent ovarian cancer. As a new development, this subject is experiencing rapid progress, and multiple avenues are opening up. Although there are many hurdles to overcome this needs constant updating, especially for students of ovarian cancer who are looking at it with much hope.

Comprehensive discovery of subsample gene expression components by information explanation: therapeutic implications in cancer

BACKGROUND

De novo inference of clinically relevant gene function relationships from tumor RNA-seq remains a challenging task. Current methods typically either partition patient samples into a few subtypes or rely upon analysis of pairwise gene correlations that will miss some groups in noisy data. Leveraging higher dimensional information can be expected to increase the power to discern targetable pathways, but this is commonly thought to be an intractable computational problem.

METHODS

In this work we adapt a recently developed machine learning algorithm for sensitive detection of complex gene relationships. The algorithm, CorEx, efficiently optimizes over multivariate mutual information and can be iteratively applied to generate a hierarchy of relatively independent latent factors. The learned latent factors are used to stratify patients for survival analysis with respect to both single factors and combinations. These analyses are performed and interpreted in the context of biological function annotations and protein network interactions that might be utilized to match patients to multiple therapies.

RESULTS

Analysis of ovarian tumor RNA-seq samples demonstrates the algorithm's power to infer well over one hundred biologically interpretable gene cohorts, several times more than standard methods such as hierarchical clustering and k-means. The CorEx factor hierarchy is also informative, with related but distinct gene clusters grouped by upper nodes. Some latent factors correlate with patient survival, including one for a pathway connected with the epithelial-mesenchymal transition in breast cancer that is regulated by a microRNA that modulates epigenetics. Further, combinations of factors lead to a synergistic survival advantage in some cases.

CONCLUSIONS

In contrast to studies that attempt to partition patients into a small number of subtypes (typically 4 or fewer) for treatment purposes, our approach utilizes subgroup information for combinatoric transcriptional phenotyping. Considering only the 66 gene expression groups that are found to both have significant Gene Ontology enrichment and are small enough to indicate specific drug targets implies a computational phenotype for ovarian cancer that allows for 366 possible patient profiles, enabling truly personalized treatment. The findings here demonstrate a new technique that sheds light on the complexity of gene expression dependencies in tumors and could eventually enable the use of patient RNA-seq profiles for selection of personalized and effective cancer treatments.

The Unique Molecular and Cellular Microenvironment of Ovarian Cancer

The reciprocal interplay of cancer cells and host cells is an indispensable prerequisite for tumor growth and progression. Cells of both the innate and adaptive immune system, in particular tumor-associated macrophages (TAMs) and T cells, as well as cancer-associated fibroblasts enter into a malicious liaison with tumor cells to create a tumor-promoting and immunosuppressive tumor microenvironment (TME). Ovarian cancer, the most lethal of all gynecological malignancies, is characterized by a unique TME that enables specific and efficient metastatic routes, impairs immune surveillance, and mediates therapy resistance. A characteristic feature of the ovarian cancer TME is the role of resident host cells, in particular activated mesothelial cells, which line the peritoneal cavity in huge numbers, as well as adipocytes of the omentum, the preferred site of metastatic lesions. Another crucial factor is the peritoneal fluid, which enables the transcoelomic spread of tumor cells to other pelvic and peritoneal organs, and occurs at more advanced stages as a malignancy-associated effusion. This ascites is rich in tumor-promoting soluble factors, extracellular vesicles and detached cancer cells as well as large numbers of T cells, TAMs, and other host cells, which cooperate with resident host cells to support tumor progression and immune evasion. In this review, we summarize and discuss our current knowledge of the cellular and molecular interactions that govern this interplay with a focus on signaling networks formed by cytokines, lipids, and extracellular vesicles; the pathophysiologial roles of TAMs and T cells; the mechanism of transcoelomic metastasis; and the cell type selective processing of signals from the TME.

Establishment of specific cytotoxic T lymphocyte culture system and its inhibitory effect on ovarian cancer

The present study aimed to establish a novel method for efficiently inducing cytotoxic T lymphocytes (CTLs) in vitro, in order to develop an immune-based therapy for suppressing and killing ovarian cancer cells with a high safety and efficacy. Peripheral blood mononuclear cells (PBMCs) were stimulated with CpG oligodeoxynucleotide (CpGODN) and ginsenoside Rg1, which were united as an immune adjuvant, and human epidermal growth factor receptor 2 (HER2/neu) antigen peptide, in order to establish a specific CTL culture system in vitro. Chromosome karyotype analysis, growth curve construction and flow cytometric analysis of immune phenotypes, including cluster of differentiation (CD)3, CD4 and CD8, were performed to characterize the stimulated PBMCs in vitro. Subsequently, SKOV3 ovarian cancer cells were treated with the specific CTL culture system in vitro, and MTT assays were performed to test the inhibitory and lethal effects of the CTLs on SKOV3 cells. The number of CTLs was significantly increased from day 7 of stimulation with the specific mixture (CpGODN, ginsenoside Rg1 and HER2/neu) (P<0.01), and plateaued on day 19. Following activation, the number of CD3⁺, CD3⁺CD4⁺ and CD3⁺CD8⁺ cells was significantly increased (P<0.01). The lymphocyte karyotype did not change following exposure to antigen. After treatment with the specific CTL system, the number of SKOV3 cells in the experimental group was significantly reduced compared with that in the control group (P<0.01). The results of the present study suggested that two novel immune adjuvants, CpGODN and ginsenoside Rg1, could be combined with the HER2/neu antigen peptide to establish a specific CTL culture system in vitro. This system demonstrated a high antigen specificity, safety and proliferative ability, and exerted significant lethal and inhibitory effects on SKOV3 cells in vitro.

The transcriptional signature of human ovarian carcinoma macrophages is associated with extracellular matrix reorganization

Macrophages occur as resident cells of fetal origin or as infiltrating blood monocyte-derived cells. Despite the critical role of tumor-associated macrophages (TAMs) in tumor progression, the contribution of these developmentally and functionally distinct macrophage subsets and their alteration by the tumor microenvironment are poorly understood. We have addressed this question by comparing TAMs from human ovarian carcinoma ascites, resident peritoneal macrophages (pMPHs) and monocyte-derived macrophages (MDMs). Our study revealed striking a similarity between TAMs and pMPHs, which was considerably greater that the resemblance of TAMs and MDMs, including their transcriptomes, their inflammation-related activation state, the presence of receptors mediating immune functions and the expression of tumor-promoting mediators. Consistent with these results, TAMs phagocytized bacteria, presented peptide antigens and activated cytotoxic T cells within their pathophysiological environment. These observations support the notion that tumor-promoting properties of TAMs may reflect, at least to some extent, normal features of resident macrophages rather than functions induced by the tumor microenvironment. In spite of these surprising similarities between TAMs and pMPHs, bioinformatic analyses identified a TAM-selective signature of 30 genes that are upregulated relative to both pMPHs and MDMs. The majority of these genes is linked to extracellular matrix (ECM) remodeling, supporting a role for TAMs in cancer cell invasion and ovarian cancer progression.

Metabolic risk factors and mechanisms of disease in epithelial ovarian cancer: A review

OBJECTIVE

Epithelial ovarian cancer continues to be the deadliest gynecologic malignancy. Patients with both diabetes mellitus and obesity have poorer outcomes, yet research correlating metabolic abnormalities, such as metabolic syndrome, to ovarian cancer risk and outcomes is lacking. This article reviews the literature regarding metabolic derangements and their relationship to epithelial ovarian cancer, with a focus on potential mechanisms behind these associations.

METHODS

PubMed and Google Scholar were searched for articles in the English language regarding epithelial ovarian cancer, obesity, diabetes mellitus, and metabolic syndrome, with a focus on studies conducted since 1990.

RESULTS

Obesity, type II diabetes mellitus, and metabolic syndrome have been associated with poor outcomes in epithelial ovarian cancer. More studies investigating the relationship between metabolic syndrome and epithelial ovarian cancer are needed. A variety of pathologic factors may contribute to cancer risk in patients with metabolic derangements, including altered adipokine and cytokine expression, altered immune responses to tumor cells, and changes in pro-tumorigenic signaling pathways.

CONCLUSION

More research is needed to examine the effects of metabolic syndrome on epithelial ovarian cancer risk and mortality, as well as the underlying pathophysiologies in patients with obesity, diabetes mellitus, and metabolic syndrome that may be targeted for therapeutic intervention.

IL-27 induces the expression of IDO and PD-L1 in human cancer cells

IL-27 is a member of the IL-12 family that is produced by macrophages and dendritic cells. IL-27 inhibits the growth and invasiveness of different cancers and therefore represents a potential anti-tumor agent. By contrast, it may exert immune-regulatory properties in different biological systems. We reported that IL-27 induces the expression of the IL-18 inhibitor IL-18BP, in human Epithelial Ovarian Cancer (EOC) cells, thus potentially limiting the immune response. Here, we tested whether IL-27 may modulate other immune-regulatory molecules involved in EOC progression, including Indoleamine 2,3-dioxygenase (IDO) and Programmed Death-Ligand (PD-L)1. IDO and PD-L1 were not constitutively expressed by EOC cells in vitro, but IL-27 increased their expression through STAT1 and STAT3 tyrosine phosphorylation. Differently, cells isolated from EOC ascites showed constitutive activation of STAT1 and STAT3 and IDO expression. These findings, together with the expression of IL-27 in scattered leukocytes in EOC ascites and tissues, suggest a potential role of IL-27 in immune-regulatory networks of EOC. In addition, IL-27 induced IDO or PD-L1 expression in monocytes and in human PC3 prostate and A549 lung cancer cells. A current paradigm in tumor immunology is that tumor cells may escape from immune control due to “adaptive resistance” mediated by T cell-secreted IFN-γ, which induces PD-L1 and IDO expression in tumor cells. Our present data indicate that also IL-27 has similar activities and suggest that the therapeutic use of IL-27 as anti-cancer agent may have dual effects, in some tumors.

A phase 1/2 study combining gemcitabine, Pegintron and p53 SLP vaccine in patients with platinum-resistant ovarian cancer

Purpose

Preclinical tumor models show that chemotherapy has immune modulatory properties which can be exploited in the context of immunotherapy. The purpose of this study was to determine the feasibility and immunogenicity of combinations of such an immunomodulatory chemotherapeutic agent with immunotherapy, p53 synthetic long peptide (SLP) vaccine and Pegintron (IFN-α) in patients with platinum-resistant p53-positive epithelial ovarian cancer (EOC).

Experimental design

This is a phase 1/2 trial in which patients sequential 6 cycles of gemcitabine (1000 mg/kg² iv; n = 3), gemcitabine with Pegintron before and after the first gemcitabine cycle (Pegintron 1 μg/kg sc; n = 6), and gemcitabine and Pegintron combined with p53 SLP vaccine (0.3 mg/peptide, 9 peptides; n = 6). At baseline, 22 days after the 2^nd and 6^th cycle, blood was collected for immunomonitoring. Toxicity, CA-125, and radiologic response were evaluated after 3 and 6 cycles of chemotherapy.

Results

None of the patients enrolled experienced dose-limiting toxicity. Predominant grade 3/4 toxicities were nausea/vomiting and dyspnea. Grade 1/2 toxicities consisted of fatigue (78%) and Pegintron-related flu-like symptoms (72%). Gemcitabine reduced myeloid-derived suppressor cells (p = 0.0005) and increased immune-supportive M1 macrophages (p = 0.04). Combination of gemcitabine and Pegintron stimulated higher frequencies of circulating proliferating CD4+ and CD8+ T-cells but not regulatory T-cells. All vaccinated patients showed strong vaccine-induced p53-specific T-cell responses.

Conclusion

Combination of gemcitabine, the immune modulator Pegintron and therapeutic peptide vaccination is a viable approach in the development of combined chemo-immunotherapeutic regimens to treat cancer.

MALDI mass spectrometry imaging: A cutting-edge tool for fundamental and clinical histopathology

Histopathological diagnoses have been done in the last century based on hematoxylin and eosin staining. These methods were complemented by histochemistry, electron microscopy, immunohistochemistry (IHC), and molecular techniques. Mass spectrometry (MS) methods allow the thorough examination of various biocompounds in extracts and tissue sections. Today, mass spectrometry imaging (MSI), and especially matrix-assisted laser desorption ionization (MALDI) imaging links classical histology and molecular analyses. Direct mapping is a major advantage of the combination of molecular profiling and imaging. MSI can be considered as a cutting edge approach for molecular detection of proteins, peptides, carbohydrates, lipids, and small molecules in tissues. This review covers the detection of various biomolecules in histopathological sections by MSI. Proteomic methods will be introduced into clinical histopathology within the next few years.

The role of reproductive hormones in epithelial ovarian carcinogenesis

Epithelial ovarian cancer comprises ∼85% of all ovarian cancer cases. Despite acceptance regarding the influence of reproductive hormones on ovarian cancer risk and considerable advances in the understanding of epithelial ovarian carcinogenesis on a molecular level, complete understanding of the biologic processes underlying malignant transformation of ovarian surface epithelium is lacking. Various hypotheses have been proposed over the past several decades to explain the etiology of the disease. The role of reproductive hormones in epithelial ovarian carcinogenesis remains a key topic of research. Primary questions in the field of ovarian cancer biology center on its developmental cell of origin, the positive and negative effects of each class of hormones on ovarian cancer initiation and progression, and the role of the immune system in the ovarian cancer microenvironment. The development of the female reproductive tract is dictated by the hormonal milieu during embryogenesis. Intensive research efforts have revealed that ovarian cancer is a heterogenous disease that may develop from multiple extra-ovarian tissues, including both Müllerian (fallopian tubes, endometrium) and non-Müllerian structures (gastrointestinal tissue), contributing to its heterogeneity and distinct histologic subtypes. The mechanism underlying ovarian localization, however, remains unclear. Here, we discuss the role of reproductive hormones in influencing the immune system and tipping the balance against or in favor of developing ovarian cancer. We comment on animal models that are critical for experimentally validating existing hypotheses in key areas of endocrine research and useful for preclinical drug development. Finally, we address emerging therapeutic trends directed against ovarian cancer.

Cancer-testis antigen cyclin A1 is broadly expressed in ovarian cancer and is associated with prolonged time to tumor progression after platinum-based therapy

BACKGROUND

Cyclin A1 is essential for male gametopoiesis. In acute myeloid leukemia, it acts as a leukemia-associated antigen. Cyclin A1 expression has been reported in several epithelial malignancies, including testicular, endometrial, and epithelial ovarian cancer (EOC). We analyzed Cyclin A1 expression in EOC and its correlation with clinical features to evaluate Cyclin A1 as a T-cell target in EOC.

METHODS

Cyclin A1 mRNA expression in EOC and healthy tissues was quantified by microarray analysis and quantitative real-time PCR (qRT-PCR). Protein expression in clinical samples was assessed by immunohistochemistry (IHC) and was correlated to clinical features.

RESULTS

Cyclin A1 protein was homogeneously expressed in 43 of 62 grade 3 tumor samples and in 1 of 10 grade 2 specimens (p < 0.001). Survival analysis showed longer time to progression (TTP) among patients with at least moderate Cyclin A1 expression (univariate: p = 0.018, multivariate: p = 0.035). FIGO stage, grading, age, macroscopic residual tumor after debulking, and peritoneal carcinomatosis / distant metastasis had no impact on TTP or overall survival (OS).

CONCLUSION

Cyclin A1 is highly expressed in most EOCs. The mechanism behind the prolonged TTP in patients with high Cyclin A1 expression warrants further investigation. The frequent, selectively high expression of Cyclin A1 in EOC makes it a promising target for T-cell therapies.

Prognostic Role of Serum Antibody Immunity to p53 Oncogenic Protein in Ovarian Cancer: A Systematic Review and a Meta-Analysis

Objective

Serum p53 autoantibodies (p53-AAbs) are the product of an endogenous immune response against p53 overexpression driven by the ovarian tumour. The p53-AAbs are detectable only in a subset of patients. To date, the evidence of an association between the presence of p53-AAbs and ovarian cancer outcomes has been poorly investigated.

Methods

A systematic literature search was performed to identify eligible studies investigating the association of serum p53-AAbs and overall survival (OS) and disease free survival (DFS). Associations between presence of serum p53-AAbs and baseline tumour characteristics were also evaluated. Pooled hazard ratios (HRs) and corresponding 95% confidence intervals (CI) were computed to estimate the prognostic impact of serum p53-AAbs. Heterogeneity between studies was assessed.

Results

A total of 583 patients (7 studies) for OS and 356 patients (4 studies) for DFS were included in the meta-analysis. Presence of p53-AAbs was not associated to OS (pooled uni- multivariate HR = 1.09; 95% CI: 0.55–2.16), and a large heterogeneity was found. When only multivariate HRs were pooled together (4 studies), presence of p53-AAbs was significantly associated to a better OS (pooled HR = 0.57; 95% CI: 0.40–0.81), and no significant heterogeneity was observed. A reduced DFS was associated to p53-AAbs (pooled uni- multivariate HR = 1.37; 95% CI: 0.83–2.25), though not significantly and with a moderate heterogeneity.

Conclusions

The prognostic significance of serum p53-AAbs in ovarian cancer was diverging according to uni or multivariate models used. Since the results of this work were based on only few investigations, large prospective studies are needed to better define the role of antibody immunity against p53.

Regulatory T cells, inherited variation, and clinical outcome in epithelial ovarian cancer

The immune system constitutes one of the host factors modifying outcomes in ovarian cancer. Regulatory T cells (Tregs) are believed to be a major factor in preventing the immune response from destroying ovarian cancers. Understanding mechanisms that regulate Tregs in the tumor microenvironment could lead to the identification of novel targets aimed at reducing their influence. In this study, we used immunofluorescence-based microscopy to enumerate Tregs, total CD4 T cells, and CD8(+) cytotoxic T cells in fresh frozen tumors from over 400 patients with ovarian cancer (>80 % high-grade serous). We sought to determine whether Tregs were associated with survival and genetic variation in 79 genes known to influence Treg induction, trafficking, or function. We used Cox regression, accounting for known prognostic factors, to estimate hazard ratios (HRs) associated with T cell counts and ratios. We found that the ratios of CD8 T cells and total CD4 T cells to Tregs were associated with improved overall survival (CD8/Treg HR 0.84, p = 0.0089; CD4/Treg HR 0.88, p = 0.046) and with genetic variation in IL-10 (p = 0.0073 and 0.01, respectively). In multivariate analyses, the associations between the ratios and overall survival remained similar (IL-10 and clinical covariate-adjusted CD8/Treg HR 0.85, p = 0.031; CD4/Treg HR 0.87, p = 0.093), suggesting that this association was not driven by variation in IL-10. Thus, integration of novel tumor phenotyping measures with extensive clinical and genetic information suggests that the ratio of T cells to Tregs may be prognostic of outcome in ovarian cancer, regardless of inherited genotype in genes related to Tregs.

Murine lung cancer induces generalized T-cell exhaustion

BACKGROUND

Cancer is known to modulate tumor-specific immune responses by establishing a microenvironment that leads to the upregulation of T-cell inhibitory receptors, resulting in the progressive loss of function and eventual death of tumor-specific T-cells. However, the ability of cancer to impact the functionality of the immune system on a systemic level is much less well characterized. Because cancer is known to predispose patients to infectious complications including sepsis, we hypothesized that the presence of cancer alters pathogen-directed immune responses on a systemic level.

MATERIALS AND METHODS

We assessed systemic T-cell coinhibitory receptor expression, cytokine production, and apoptosis in mice with established subcutaneous lung cancer tumors and in unmanipulated mice without cancer.

RESULTS

Results indicated that the frequencies of programmed death-1-positive, B and T lymphocyte attenuator-positive, and 2B4(+) cells in both the CD4(+) and CD8(+) T-cell compartments were increased in mice with localized cancer relative to non-cancer controls, and the frequencies of both CD4(+) and CD8(+) T-cells expressing multiple different inhibitory receptors were increased in cancer animals relative to non-cancer controls. Additionally, 2B4(+)CD8(+) T-cells in cancer mice exhibited reduced interleukin-2 and interferon-γ, whereas B and T lymphocyte attenuator-positive CD8(+) T-cells in cancer mice exhibited reduced interleukin-2 and tumor necrosis factor. Conversely, CD4(+) T-cells in cancer animals demonstrated an increase in the frequency of annexin V(+) apoptotic cells.

CONCLUSIONS

Taken together, these data suggest that the presence of cancer induces systemic T-cell exhaustion and generalized immune suppression.

Differential antigen expression profile predicts immunoreactive subset of advanced ovarian cancers

The presence and composition of lymphocytes characterizing an immune response has been connected to prognosis in advanced ovarian cancer. Our aim is to establish novel associations between prognosis and the expression of immune-related genes through a focused screen utilizing publicly available high-throughput assays. We consider transcriptome profiles from n=1137 advanced ovarian cancer patients observed in four separate studies divided into discovery/validation sets (n=503/n=634). We focus on a subset of lymphocyte markers, antigen presentation and processing genes, T cell receptor associated co-stimulatory/repressor genes and cancer testis (CT) antigens. We modeled differential expression and co-expression using these subsets and tested for association with overall survival. Fifteen of 64 immune-related genes are associated with survival of which 5 are reproduced in the validation set. The expression of these genes defines an immunoreactive (IR) subgroup of patients with a favorable prognosis. Phenotypic characterization of the immune compartment signal includes upregulation of markers of CD8+ T-cell activation in these patients. Using multivariate model building, we find that the expression of 6 CT antigens can predict IR status in the discovery and validation sets. These analyses confirm that a genomic approach can reproducibly detect lymphocyte signals in tumor tissue suggesting a novel way to study the tumor microenvironment. Our search has identified new candidate prognostic markers associated with immune components and uncovered preliminary evidence of prognostic subgroups associated with different immune mechanisms.

Cytotoxicity of human endogenous retrovirus K-specific T cells toward autologous ovarian cancer cells

PURPOSE

To determine whether HERV-K envelope (ENV) protein could function as a tumor-associated antigen and elicit specific T-cell responses against autologous ovarian cancer cells.

EXPERIMENTAL DESIGN

The expression of HERV-K transcripts and ENV protein, the presence of serum antibodies against HERV-K, reverse transcriptase (RT) activities, and cellular immune responses in primary ovarian cancer tissues and patient blood samples were analyzed and compared with samples from patients with benign ovarian diseases and normal female donors.

RESULTS

Ovarian cancer cells in primary tumors and ascites expressed markers of cancer stem cells and markers of both mesenchymal and epithelial cells. Expression of HERV transcripts and HERV-K ENV protein and reverse transcriptase activities were higher in ovarian cancer compared with adjacent normal and benign tissues. The ovarian cancer patient plasma also had high reverse transcriptase activities and the ovarian cancer patient sera contained HERV-K immunoreactive antibodies. HERV-K-specific T cells generated from autologous dendritic cells pulsed with HERV-K ENV antigens exhibited phenotypes and functions consistent with a cellular immune response including T-cell proliferation, IFNγ production, and HERV-K-specific cytotoxic T lymphocyte (CTL) activity. Significantly higher CTL lysis of autologous tumor cells than of uninvolved normal cells was demonstrated in patients with ovarian cancer than patients with benign diseases and further enhanced lysis was observed if T regulatory cells were depleted.

CONCLUSION

Endogenous retroviral gene products in ovarian cancer may represent a potentially valuable new pool of tumor-associated antigens for targeting of therapeutic vaccines to ovarian cancer. Clin Cancer Res; 21(2); 471-83. ©2014 AACR.

Molecular profiling and clinical outcome of high-grade serous ovarian cancer presenting with low- versus high-volume ascites

Epithelial ovarian cancer consists of multiple histotypes differing in etiology and clinical course. The most prevalent histotype is high-grade serous ovarian cancer (HGSOC), which often presents at an advanced stage frequently accompanied with high-volume ascites. While some studies suggest that ascites is associated with poor clinical outcome, most reports have not differentiated between histological subtypes or tumor grade. We compared genome-wide gene expression profiles from a discovery cohort of ten patients diagnosed with stages III-IV HGSOC with high-volume ascites and nine patients with low-volume ascites. An upregulation of immune response genes was detected in tumors from patients presenting with low-volume ascites relative to those with high-volume ascites. Immunohistochemical studies performed on tissue microarrays confirmed higher expression of proteins encoded by immune response genes and increased tumorinfiltrating cells in tumors associated with low-volume ascites. Comparison of 149 advanced-stage HGSOC cases with differential ascites volume at time of primary surgery indicated low-volume ascites correlated with better surgical outcome and longer overall survival. These findings suggest that advanced stage HGSOC presenting with low-volume ascites reflects a unique subgroup of HGSOC, which is associated with upregulation of immune related genes, more abundant tumor infiltrating cells and better clinical outcomes.

Phenotypic T cell exhaustion in a murine model of bacterial infection in the setting of pre-existing malignancy

While much of cancer immunology research has focused on anti-tumor immunity both systemically and within the tumor microenvironment, little is known about the impact of pre-existing malignancy on pathogen-specific immune responses. Here, we sought to characterize the antigen-specific CD8⁺ T cell response following a bacterial infection in the setting of pre-existing pancreatic adenocarcinoma. Mice with established subcutaneous pancreatic adenocarcinomas were infected with Listeria monocytogenes, and antigen-specific CD8⁺ T cell responses were compared to those in control mice without cancer. While the kinetics and magnitude of antigen-specific CD8⁺ T cell expansion and accumulation was comparable between the cancer and non-cancer groups, bacterial antigen-specific CD8⁺ T cells and total CD4⁺ and CD8⁺ T cells in cancer mice exhibited increased expression of the coinhibitory receptors BTLA, PD-1, and 2B4. Furthermore, increased inhibitory receptor expression was associated with reduced IFN-γ and increased IL-2 production by bacterial antigen-specific CD8⁺ T cells in the cancer group. Taken together, these data suggest that cancer's immune suppressive effects are not limited to the tumor microenvironment, but that pre-existing malignancy induces phenotypic exhaustion in T cells by increasing expression of coinhibitory receptors and may impair pathogen-specific CD8⁺ T cell functionality and differentiation.

Orthotopic, syngeneic mouse model to study the effects of epithelial-stromal interaction

One of the difficulties in studying ovarian cancer historically has been the lack of a suitable animal model that replicates the human disease. Mouse models that utilize intraperitoneal implantation of tumorigenic cells lack interaction between the transformed ovarian epithelial cells and the ovarian stroma, which we have shown to be an integral component in replicating the etiology seen in human epithelial ovarian cancer (Greenaway, Gynecol Oncol 108:385-394, 2008). Xenograft models generally require the use of immunocompromised hosts, which then eliminates the influence of the immune system in disease progression, which also has been shown to be an important part of the progression of epithelial ovarian cancer (EOC). In this chapter, we describe the generation and optimization of an orthotopic, syngeneic mouse model and illustrate the importance of facilitating epithelial-stromal cell interaction to more closely replicate human EOC.

In vitro ovarian cancer model based on three-dimensional agarose hydrogel

To establish a typical tumor model of ovarian cancer which may be more representative and reliable than traditional monolayer culture and pellet, agarose was used as cell vehicle to engineering tumor. Selection of agarose is based on its successful application in tissue engineering with both amenable mechanical and biological properties. In this study, ovarian cancer cell line SKOV3 was encapsulated in agarose hydrogel with cell aggregates and two-dimensional culture as controls. In vitro cell proliferation was assessed by MTT and cell viability was examined at time points of 2, 4, and 6 days. The expression of tumor malignancy markers including matrix metalloproteinase 2, matrix metalloproteinase 9, hypoxia-inducible factor-1α, and vascular endothelial growth factor–A was assessed by real-time polymerase chain reaction. The results showed that cells proliferated more rapidly in three-dimensional agarose culture than controls. Furthermore, upregulation of matrix metalloproteinase 9 and matrix metalloproteinase 2 activity and increased expression of vascular endothelial growth factor–A and hypoxia-inducible factor-1α were shown in agarose-engineered tumors. All the evidences demonstrated that agarose may provide a more favorable environment for cancer cell growth, mimicking the in vivo environment for tumor generation. The novel in vitro tumor model may be useful for the further investigation of anticancer therapeutics.

Chemokine receptors in epithelial ovarian cancer

Ovarian carcinoma is the deadliest gynecologic malignancy with very poor rate of survival, and it is characterized by the presence of vast incurable peritoneal metastasis. Studies of the role of chemokine receptors, a family of proteins belonging to the group of G protein-coupled receptors, in ovarian carcinoma strongly placed this family of membrane receptors as major regulators of progression of this malignancy. In this review, we will discuss the roles that chemokine-receptor interactions play to support angiogenesis, cell proliferation, migration, adhesion, invasion, metastasis, and immune evasion in progression of ovarian carcinoma. Data regarding the role that the chemokine receptors play in the disease progression accumulated insofar strongly suggest that this family of proteins could be good therapeutic targets against ovarian carcinoma.

[Immunotherapy in epithelial ovarian carcinoma: hope and reality]

INTRODUCTION

Epithelial ovarian carcinoma (EOC) has a worst prognosis with little progress in terms of survival for the last two decades. Immunology received little interest in EOC in the past, but now appears very important in the natural history of this cancer. This review is an EOC immunology state of art and focuses on the place of immunotherapy in future.

MATERIAL AND METHODS

A systematic review of published studies was performed. Medline baseline interrogation was performed with the following keywords: "Ovarian carinoma, immunotherapy, T-lymphocyte, regulator T-lymphocyte, dendritic cells, macrophage, antigen, chemotherapy, surgery, clinical trials". Identified publications (English or French) were assessed for the understanding of EOC immunology and the place of conventional treatment and immunotherapy strategy.

RESULTS

Intratumoral infiltration by immune cells is a strong prognotic factor in EOC. Surgery and chemotherapy in EOC decrease imunosuppression in patients. The antitumoral immunity is a part of the therapeutic action of surgery and chemotherapy. Until now, immunotherapy gave some disappointing results, but the new drugs that target the tolerogenic tumoral microenvironnement rise and give a new hope in the treatment of cancer.

CONCLUSION

Immunology controls the EOC natural history. The modulation of immunosuppressive microenvironment associated with the stimulation of antitumoral immunity could be the next revolution in the treatment of cancer.

The ratios of CD8+ T cells to CD4+CD25+ FOXP3+ and FOXP3- T cells correlate with poor clinical outcome in human serous ovarian cancer

Ovarian cancer is an immune reactive malignancy with a complex immune suppressive network that blunts successful immune eradication. This suppressive microenvironment may be mediated by recruitment or induction of CD4⁺ regulatory T cells (Tregs). Our study sought to investigate the association of tumor-infiltrating CD4⁺CD25⁺FOXP3⁺ Tregs, and other immune factors, with clinical outcome in serous ovarian cancer patients. We performed immunofluorescence and quantification of intraepithelial tumor-infiltrating triple positive Tregs (CD4⁺CD25⁺FOXP3⁺), as well as CD4⁺CD25⁺FOXP3^-, CD3⁺ and CD8⁺ T cells in tumor specimens from 52 patients with high stage serous ovarian carcinoma. Thirty-one of the patients had good survival (i.e. > 60 months) and 21 had poor survival of < 18 months. Total cell counts as well as cell ratios were compared among these two outcome groups. The total numbers of CD4⁺CD25⁺FOXP3⁺ Tregs, CD4⁺CD25⁺FOXP3^-, CD3⁺ and CD8⁺ cells were not significantly different between the groups. However, higher ratios of CD8⁺/CD4⁺CD25⁺FOXP3⁺ Treg, CD8⁺/CD4⁺ and CD8/CD4⁺CD25⁺FOXP3^- cells were seen in the good outcome group when compared to the patients with poor outcome. These data show for the first time that the ratios of CD8⁺ to both CD4⁺CD25⁺FOXP3⁺ Tregs and CD4⁺CD25⁺FOXP3^- T cells are associated with disease outcome in ovarian cancer. The association being apparent in ratios rather than absolute count of T cells suggests that the effector/suppressor ratio may be a more important indicator of outcome than individual cell count. Thus, immunotherapy strategies that modify the ratio of CD4⁺CD25⁺FOXP3⁺ Tregs or CD4⁺CD25⁺FOXP3^- T cells to CD8⁺ effector cells may be useful in improving outcomes in ovarian cancer.

Aiming to immune elimination of ovarian cancer stem cells

Ovarian cancer accounts for only 3% of all cancers in women, but it causes more deaths than any other gynecologic cancer. Treatment with chemotherapy and cytoreductive surgery shows a good response to the therapy. However, in a large proportion of the patients the tumor grows back within a few years. Cancer stem cells, that are less responsive to these treatments, are blamed for this recurrence of disease. Immune therapy either cellular or humoral is a novel concept to treat cancer. It is based on the notice that immune cells invade the tumor. However, the tumor invest heavily to escape from immune elimination by recruiting several immune suppressive mechanisms. These processes are normally in place to limit excessive immune activation and prevent autoimmune phenomena. Here, we discuss current knowledge about the immune (suppressive) status in ovarian cancer. Moreover, we discuss the immunological targets of ovarian cancer stem cells.

The role of interleukin-6 in the evolution of ovarian cancer: clinical and prognostic implications--a review

An increasing number of studies emphasize the role of inflammation and metabolic changes in the induction of cancer-related symptoms, which can affect cancer evolution and prognosis. These changes result from the interactions between the tumor and the host. To date, however, markers of this peculiar condition, which can help clinicians to manage patients better, have still not been identified with certainty. Epithelial ovarian cancer (EOC) appears to be particularly appropriate to study these interactions because of its biological characteristics, its peculiar evolution, and the relevant scientific evidence available. Immunosuppression, anemia, depression, and weight loss affect the evolution of EOC and appear to be directly related to the immune-metabolic changes. In light of the aforementioned evidence, our review will focus on interleukin-6 (IL-6) and its role as potential marker of the patients' immune-metabolic status, to better monitor disease outcome and identify the most appropriate therapeutic strategy in EOC. Furthermore, leptin will be discussed as a sensor of the changes of energy metabolism induced by IL-6.

The IL-18 antagonist IL-18-binding protein is produced in the human ovarian cancer microenvironment

PURPOSE

Interleukin (IL)-18 is an immune-enhancing cytokine, which induces IFN-γ production, T-helper 1 responses, and antitumor effects. In turn, IFN-γ stimulates IL-18-binding protein production, which blocks IL-18 activity. In view of the potential use of IL-18 in epithelial ovarian cancer (EOC) immunotherapy, here, we studied IL-18BP expression and its regulation by cytokines in EOC cells in vitro and in vivo.

EXPERIMENTAL DESIGN

Expression and production of IL-18BP in EOC cell lines, primary ovarian carcinomas, and the corresponding normal tissues, patients' serum, and ascites were investigated by immunochemistry, ELISA, screening of gene expression profiles, and reverse-transcription PCR.

RESULTS

Analysis of gene expression profiles revealed that IL18BP mRNA is increased in EOC tumors compared with normal ovary cells. Release of IL-18BP was detectable in EOC sera and to a greater extent in the ascites, indicating production at the tumor site. Indeed, immunochemical analyses on cells isolated from the ascites and on tumor sections indicated that IL-18BP is expressed in both tumor cells and tumor-associated leukocytes, which displayed a CD3-CD20-NKp46-CD13+CD14low phenotype. EOC cell lines do not constitutively express IL-18BP. However, its release is inducible both by IFN-γ stimulation in vitro and by xenotransplantation of EOC cells in immune-deficient mice, suggesting a role for the microenvironment. In vitro experiments and immunochemistry indicated that IL-27 is also involved in IL-18BP upregulation in EOC cell lines and primary cells through STAT1 activation. Together, these data indicate that IL-18BP, which is produced in EOC in response to microenvironmental factors, may inhibit endogenous or exogenous IL-18 activity.

Ovarian cancer molecular pathology

Ovarian cancer (OVC) is the fourth leading cause of cancer mortality among women in Europe and the United States. Its early detection is difficult due to the lack of specificity of clinical symptoms. Unfortunately, late diagnosis is a major contributor to the poor survival rates for OVC, which can be attributed to the lack of specific sets of markers. Aside from patients sharing a strong family history of ovarian and breast cancer, including the BRCA1 and BRCA2 tumor suppressor genes mutations, the most used biomarker is the Cancer-antigen 125 (CA-125). CA-125 has a sensitivity of 80 % and a specificity of 97 % in epithelial cancer (stage III or IV). However, its sensitivity is 30 % in stage I cancer, as its increase is linked to several physiological phenomena and benign situations. CA-125 is particularly useful for at-risk population diagnosis and to assess response to treatment. It is clear that alone, CA-125 is inadequate as a biomarker for OVC diagnosis. There is an unmet need to identify additional biomarkers. Novel and more sensitive proteomic strategies such as MALDI mass spectrometry imaging studies are well suited to identify better markers for both diagnosis and prognosis. In the present review, we will focus on such proteomic strategies in regards to OVC signaling pathways, OVC development and escape from the immune response.

Immunity of human epithelial ovarian carcinoma: the paradigm of immune suppression in cancer

Epithelial ovarian cancer (EOC) is a significant cause of cancer-related mortality in women, and there has been no substantial decrease in the death rates due to EOC in the last three decades. Thus, basic knowledge regarding ovarian tumor cell biology is urgently needed to allow the development of innovative treatments for EOC. Traditionally, EOC has not been considered an immunogenic tumor, but there is evidence of an immune response to EOC in patients. Clinical data demonstrate that an antitumor immune response and immune evasion mechanisms are correlated with a better and lower survival, respectively, providing evidence for the immunoediting hypothesis in EOC. This review focuses on the immune response and immune suppression in EOC. The immunological roles of chemotherapy and surgery in EOC are also described. Finally, we detail pilot data supporting the efficiency of immunotherapy in the treatment of EOC and the emerging concept that immunomodulation aimed at counteracting the immunosuppressive microenvironment must be associated with immunotherapy strategies.

Dendritic cell immunotherapy in ovarian cancer

Ovarian cancer is one of the most frequent gynecological malignancies. However, as there is no effective screening method to detect early disease, it is usually only diagnosed when already widespread in the abdomen. The majority of patients diagnosed with advanced-stage disease will relapse and require additional therapy. In the search for additional effective treatments for the management of recurrent disease, researchers have focused on the potential usefulness of immunotherapeutic modulation by administering autologous immune cells, such as dendritic cells (DCs), to stimulate antitumor host responses. With the ultimate goal of improved survival, this review addresses mechanisms in ovarian cancer that may limit the expansion of antitumor immunity, discusses the parameters to be considered for optimal DC immunotherapy, outlines evaluation methodology used to monitor the success of treatment regimens and reviews reported DC immunotherapy trials in ovarian cancer.

Functional OCT4-specific CD4+ and CD8+ T cells in healthy controls and ovarian cancer patients

The identification of growth and differentiation pathways that are responsible for the proliferation and survival of cancer stem cells (CSCs) has opened avenues for the discovery of novel therapeutic targets. In the initial phase of an anticancer immune response, T cells specific for tumor-associated antigens develop in patients and, at least under selected circumstances, are able to eliminate malignant cells. However, it remains unknown whether CSC-specific T cells are also operational. We found naturally occurring multifunctional CD4⁺ and CD8⁺ T cells specific for the stem cell marker OCT4 among the peripheral blood mononuclear cells (PBMCs) of both healthy individuals and ovarian cancer patients. Moreover, lymphocytes isolated from the ascites of patients affected by ovarian malignancies also contained OCT4-specific T cells. OCT4-reactive CD4⁺ T cells did not produce interferon γ (IFNγ) and IFNγ-inducible protein 10 (IP-10) but were capable of proliferation upon stimulation with dendritic cells (DCs) loaded with an OCT4-derived peptide or OCT4 mRNA. OCT4-reactive CD8⁺ cells did not proliferate in response to a similar challenge, yet produced IP-10 as well as sufficient amounts of IFNγ to induce IP-10 . Furthermore, CD8⁺ cytotoxic T cells were able to release their lysosomal components, as indicated by the mobilization of CD107a. These results demonstrate the existence of anti-CSC specific T cells in ovarian cancer patients.

Inherited variants in regulatory T cell genes and outcome of ovarian cancer

Although ovarian cancer is the most lethal of gynecologic malignancies, wide variation in outcome following conventional therapy continues to exist. The presence of tumor-infiltrating regulatory T cells (Tregs) has a role in outcome of this disease, and a growing body of data supports the existence of inherited prognostic factors. However, the role of inherited variants in genes encoding Treg-related immune molecules has not been fully explored. We analyzed expression quantitative trait loci (eQTL) and sequence-based tagging single nucleotide polymorphisms (tagSNPs) for 54 genes associated with Tregs in 3,662 invasive ovarian cancer cases. With adjustment for known prognostic factors, suggestive results were observed among rarer histological subtypes; poorer survival was associated with minor alleles at SNPs in RGS1 (clear cell, rs10921202, p=2.7×10(-5)), LRRC32 and TNFRSF18/TNFRSF4 (mucinous, rs3781699, p=4.5×10(-4), and rs3753348, p=9.0×10(-4), respectively), and CD80 (endometrioid, rs13071247, p=8.0×10(-4)). Fo0r the latter, correlative data support a CD80 rs13071247 genotype association with CD80 tumor RNA expression (p=0.006). An additional eQTL SNP in CD80 was associated with shorter survival (rs7804190, p=8.1×10(-4)) among all cases combined. As the products of these genes are known to affect induction, trafficking, or immunosuppressive function of Tregs, these results suggest the need for follow-up phenotypic studies.

Oncolytic virotherapy for ovarian cancer

In the past two decades, more than 20 viruses with selective tropism for tumor cells have been developed as oncolytic viruses (OVs) for treatments of a variety of malignancies. Of these viruses, eleven have been tested in human ovarian cancer models in preclinical studies. So far, nine phase I or II clinical trials have been conducted or initiated using four different types of OVs in patients with recurrent ovarian cancers. In this article, we summarize the different OVs that are being assessed as therapeutics for ovarian cancer. We also present an overview of recent advances in identification of key genetic or immune-response pathways involved in tumorigenesis of ovarian cancer, which provides a better understanding of the tumor specificities and oncolytic properties of OVs. In addition, we discuss how next-generation OVs could be genetically modified or integrated into multimodality regimens to improve clinical outcomes based on recent advances in ovarian cancer biology.

Lentinan enhances the efficacy of the DCF regimen in patients with advanced gastric cancer: an analysis of 40 cases

AIM: To evaluate whether lentinan enhances the curative effects of the DCF (docetaxel, cisplatin and fluorouracil) regimen in patients with advanced gastric cancer.

METHODS: Eighty patients with stages III and IV gastric cancer who were treated at our hospital between January 2007 and December 2008 were randomly divided into two groups to receive DCF chemotherapy alone or DCF chemotherapy in combination with lentinan. The curative effects, routine blood parameters, lymphocyte subsets and quality of life were compared between the two groups.

RESULTS: The disease control rate was significantly higher in the lentinan plus DCF group than in the DCF group (87.5% vs 75.0%, P < 0.05), while the incidence of side effects (including neutropenia, leukopenia, anemia, thrombocytopenia and infection) was significantly lower in the lentinan plus DCF group than in the DCF group (P < 0.05). No significant differences were noted in routine blood parameters, lymphocyte subsets and quality of life before chemotherapy between the two groups (all P > 0.05). After chemotherapy, the numbers of WBC, lymphocytes, CD3⁺, CD4⁺, CD8⁺, NK cells and quality of life were significantly improved in the lentinan plus DCF group compared to the DCF group (all P < 0.05).

CONCLUSION: Lentinan significantly enhanced the efficacy and safety of the DCF regimen in patients with advanced gastric cancer.