Distinct subpopulations of epithelial ovarian cancer cells can differentially induce macrophages and T regulatory cells toward a pro-tumor phenotype

Immune Modulation of Innate and Adaptive Responses Restores Immune Surveillance and Establishes Antitumor Immunologic Memory

Current immunotherapies have proven effective in strengthening antitumor immune responses, but constant opposing signals from tumor cells and the surrounding microenvironment eventually lead to immune escape. We hypothesized that in situ release of antigens and regulation of both the innate and adaptive arms of the immune system would provide a robust and long-term antitumor effect by creating immunologic memory against tumors. To achieve this, we developed CARG-2020, a genetically modified virus-like vesicle (VLV) that is a self-amplifying RNA with oncolytic capacity and encodes immune regulatory genes. CARG-2020 carries three immune modulators: (i) the pleiotropic antitumor cytokine IL12, in which the subunits (p35 and p40) are tethered together; (ii) the extracellular domain (ECD) of the protumor IL17RA, which serves as a dominant-negative antagonist; and (iii) a shRNA targeting PD-L1. Using a mouse model of ovarian cancer, we demonstrated the oncolytic effect and immune-modulatory capacities of CARG-2020. By enhancing IL12 and blocking IL17 and PD-L1, CARG-2020 successfully reactivated immune surveillance by promoting M1, instead of M2, macrophage differentiation, inhibiting MDSC expansion and establishing a potent CD8+ T cell-mediated antitumoral response. Furthermore, we demonstrated that this therapeutic approach provided tumor-specific and long-term protection against the establishment of new tumors. Our results provide a rationale for the further development of this platform as a therapeutic modality for ovarian cancer patients to enhance antitumor responses and prevent a recurrence.

Immune modulation of innate and adaptive responses restores immune surveillance and establishes anti-tumor immunological memory

Current immunotherapies have proven effective in strengthening anti-tumor immune responses but constant opposing signals from tumor cells and surrounding microenvironment eventually lead to immune escape. We hypothesize that in situ release of antigens and regulation of both the innate and adaptive arms of the immune system will provide a robust and long-term anti-tumor effect by creating immunological memory against the tumor. To achieve this, we developed CARG-2020, a virus-like-vesicle (VLV). It is a genetically modified and self-amplifying RNA with oncolytic capacity and encodes immune regulatory genes. CARG-2020 carries three transgenes: 1 ) the pleiotropic antitumor cytokine IL-12 in which the subunits (p35 and p40) are tethered together; 2) the extracellular domain (ECD) of the pro- tumor IL-17RA, which can serve as a dominant negative antagonist; and 3) shRNA for PD-L1. Using a mouse model of ovarian cancer, we demonstrate the oncolytic effect and immune modulatory capacities of CARG-2020. By enhancing IL-12 and blocking IL-17 and PD-L1, CARG-2020 successfully reactivates immune surveillance by promoting M1 instead of M2 macrophage differentiation, inhibiting MDSC expansion, and establishing a potent CD8+ T cell mediated anti-tumoral response. Furthermore, we demonstrate that this therapeutic approach provides tumor-specific and long-term protection preventing the establishment of new tumors. Our results provide rationale for the further development of this platform as a therapeutic modality for ovarian cancer patients to enhance the anti-tumor response and to prevent recurrence.

Development of a Patient-Derived 3D Immuno-Oncology Platform to Potentiate Immunotherapy Responses in Ascites-Derived Circulating Tumor Cells

High-grade serous ovarian cancer (HGSOC) is responsible for the majority of gynecology cancer-related deaths. Patients in remission often relapse with more aggressive forms of disease within 2 years post-treatment. Alternative immuno-oncology (IO) strategies, such as immune checkpoint blockade (ICB) targeting the PD-(L)1 signaling axis, have proven inefficient so far. Our aim is to utilize epigenetic modulators to maximize the benefit of personalized IO combinations in ex vivo 3D patient-derived platforms and in vivo syngeneic models. Using patient-derived tumor ascites, we optimized an ex vivo 3D screening platform (PDOTS), which employs autologous immune cells and circulating ascites-derived tumor cells, to rapidly test personalized IO combinations. Most importantly, patient responses to platinum chemotherapy and poly-ADP ribose polymerase inhibitors in 3D platforms recapitulate clinical responses. Furthermore, similar to clinical trial results, responses to ICB in PDOTS tend to be low and positively correlated with the frequency of CD3+ immune cells and EPCAM+/PD-L1+ tumor cells. Thus, the greatest response observed with anti-PD-1/anti-PD-L1 immunotherapy alone is seen in patient-derived HGSOC ascites, which present with high levels of systemic CD3+ and PD-L1+ expression in immune and tumor cells, respectively. In addition, priming with epigenetic adjuvants greatly potentiates ICB in ex vivo 3D testing platforms and in vivo tumor models. We further find that epigenetic priming induces increased tumor secretion of several key cytokines known to augment T and NK cell activation and cytotoxicity, including IL-6, IP-10 (CXCL10), KC (CXCL1), and RANTES (CCL5). Moreover, epigenetic priming alone and in combination with ICB immunotherapy in patient-derived PDOTS induces rapid upregulation of CD69, a reliable early activation of immune markers in both CD4+ and CD8+ T cells. Consequently, this functional precision medicine approach could rapidly identify personalized therapeutic combinations able to potentiate ICB, which is a great advantage, especially given the current clinical difficulty of testing a high number of potential combinations in patients.

Generation of Stable Epithelial-Mesenchymal Hybrid Cancer Cells with Tumorigenic Potential

PURPOSE

Cancer progression, invasiveness, and metastatic potential have been associated with the activation of the cellular development program known as epithelial-to-mesenchymal transition (EMT). This process is known to yield not only mesenchymal cells, but instead an array of cells with different degrees of epithelial and mesenchymal phenotypes with high plasticity, usually referred to as E/M hybrid cells. The characteristics of E/M hybrid cells, their importance in tumor progression, and the key regulators in the tumor microenvironment that support this phenotype are still poorly understood.

METHODS

In this study, we established an in vitro model of EMT and characterized the different stages of differentiation, allowing us to identify the main genomic signature associated with the E/M hybrid state.

RESULTS

We report that once the cells enter the E/M hybrid state, they acquire stable anoikis resistance, invasive capacity, and tumorigenic potential. We identified the hepatocyte growth factor (HGF)/c-MET pathway as a major driver that pushes cells in the E/M hybrid state.

CONCLUSIONS

Herein, we provide a detailed characterization of the signaling pathway(s) promoting and the genes associated with the E/M hybrid state.

Immune Tumor Microenvironment in Ovarian Cancer Ascites

Ovarian cancer (OC) has a specific type of metastasis, via transcoelomic, and most of the patients are diagnosed at advanced stages with multiple tumors spread within the peritoneal cavity. The role of Malignant Ascites (MA) is to serve as a transporter of tumor cells from the primary location to the peritoneal wall or to the surface of the peritoneal organs. MA comprise cellular components with tumor and non-tumor cells and acellular components, creating a unique microenvironment capable of modifying the tumor behavior. These microenvironment factors influence tumor cell proliferation, progression, chemoresistance, and immune evasion, suggesting that MA play an active role in OC progression. Tumor cells induce a complex immune suppression that neutralizes antitumor immunity, leading to disease progression and treatment failure, provoking a tumor-promoting environment. In this review, we will focus on the High-Grade Serous Carcinoma (HGSC) microenvironment with special attention to the tumor microenvironment immunology.

Cisplatin increases immune activity of monocytes and cytotoxic T-cells in a murine model of epithelial ovarian cancer

Epithelial ovarian cancer (EOC) is an immunologically active malignancy, but thus far immune therapy has had limited success in clinical trials. One barrier to implementation of efficacious immune therapies is a lack of knowledge of the effect of chemotherapy on the monocyte-derived component of the immune infiltrate within the tumor. We utilized the ID8 murine EOC model to investigate alterations within tumor ascites that occur following administration of platinum chemotherapy. Cisplatin treatment resulted in a significant increase in monocytes within the ascites of tumor bearing mice. We identified that CD11b+ cells from the ascites of mice that have been treated with cisplatin elicits an increase in IFN-ɣ expression from CD8+ T-cells compared to CD11b+ cells from a mouse treated with vehicle control (604.0 pg/mL v. 4328.0 pg/mL; p < .0001). Splenocytes derived from tumor bearing mice released increase levels of IFN-ɣ after treatment with cisplatin when incubated with dendritic cells (DCs) and tumor antigen (62.0 v. 92.1 pg/mL; p = .03). Cisplatin induced an increase in T-cell and monocyte/macrophage activation markers (CD62L and CD301). Levels of IL-10, IL-6, and VEGF in the cell free ascites of mice treated with cisplatin decreased (p > .05). These results indicate that treatment with cisplatin leads to an increase of anti-tumor activity within the ascites related to alterations in the ascites monocytes. Further investigation of these findings in humans is necessary to identify how these cells behave in different patient subgroups and if there is a role for monocyte directed therapy in conjunction with T-cell directed therapy and/or chemotherapy.

Modeling the Early Steps of Ovarian Cancer Dissemination in an Organotypic Culture of the Human Peritoneal Cavity

The majority of ovarian cancer patients present clinically with wide-spread metastases throughout the peritoneal cavity, metastasizing to the mesothelium-lined peritoneum and visceral adipose depots within the abdomen. This unique metastatic tumor microenvironment is comprised of multiple cell types, including mesothelial cells, fibroblasts, adipocytes, macrophages, neutrophils, and T lymphocytes. Modeling advancements, including complex 3D systems and organoids, coupled with 2D cocultures, in vivo mouse models, and ex vivo human tissue cultures have greatly enhanced our understanding of the tumor-stroma interactions that are required for successful metastasis of ovarian cancer cells. However, advanced multifaceted model systems that incorporate frequency and spatial distribution of all cell types present in the tumor microenvironment of ovarian cancer are needed to enhance our knowledge of ovarian cancer biology in order to identify methods for preventing and treating metastatic disease. This review highlights the utility of recently developed modeling approaches, summarizes some of the resulting progress using these techniques, and suggests how these strategies may be implemented to elucidate signaling processes among cell types of the tumor microenvironment that promote ovarian cancer metastasis.

Transimmunization restores immune surveillance and prevents recurrence in a syngeneic mouse model of ovarian cancer

Ovarian cancer accounts for most deaths from gynecologic malignancies. Although more than 80% of patients respond to first-line standard of care, most of these responders present with recurrence and eventually succumb to carcinomatosis and chemotherapy-resistant disease. To improve patient survival, new modalities must, therefore, target or prevent recurrent disease. Here we describe for the first time a novel syngeneic mouse model of recurrent high-grade serous ovarian cancer (HGSOC), which allows immunotherapeutic interventions in a time course relevant to human carcinomatosis and disease course. Using this model, we demonstrate the efficacy of Transimmunization (TI), a dendritic cell (DC) vaccination strategy that uses autologous and physiologically derived DC loaded with autologous whole tumor antigens. TI has been proven successful in the treatment of human cutaneous T cell lymphoma and we report for the first time its in vivo efficacy against an intra-peritoneal solid tumor. Given as a single therapy, TI is able to elicit an effective anti-tumor immune response and inhibit immune-suppressive crosstalks with sufficient power to curtail tumor progression and establishment of carcinomatosis and recurrent disease. Specifically, TI is able to inhibit the expansion of tumor-associated macrophages as well as myeloid-derived suppressive cells consequently restoring T cell immune-surveillance. These results demonstrate the possible value of TI in the management of ovarian cancer and other intra-peritoneal tumors.

Tumor associated macrophages in the molecular pathogenesis of ovarian cancer

The tumor microenvironment is a critical factor that enhances cancer progression, drug resistance, and failure of therapeutic approaches. Several cellular and non-cellular factors are involved in cancer promotion. Among the several cell populations in the tumor microenvironment, macrophages, as one of the most abundant innate immune cells within the tumor milieu, have attracted extensive attention among several researchers because of their critical role in innate pathophysiology of multiple disorders, as well as ovarian cancer. High plasticity and consequent high ability to adapt to environmental alternations by adjusting their cellular metabolism and immunological phenotype is the notable characteristic of macrophages. Therefore, the critical function of tumor-associated macrophages in ovarian cancer is highlighted in the growing body of recent studies. In this article, we will comprehensively focus on significant impacts of the macrophages on ovarian cancer progression, by discussing the role of macrophages as one of the fundamental immune cells present in tumor milieu, in metabolic reprogramming of transformed cells, and involvement of these cells in the ovarian cancer initiation, progression, invasion, and angiogenesis. Moreover, we will summarise recent studies evaluating the effects of targeting macrophages in ovarian cancer.

Adipocyte microenvironment promotes Bclxl expression and confers chemoresistance in ovarian cancer cells

Resistance to mitochondria-initiated apoptosis is a hallmark of chemoresistant cancer stem cells including CD44+/MyD88+ epithelial ovarian cancer (EOC) stem cells. This is controlled by members of the Bcl₂ family of proteins, which function as rheostats of mitochondrial stability. We observed a differential expression profile of Bcl₂ family members comparing the chemoresistant EOC stem cells and the chemosensitive CD44-/MyD88- EOC cells. Chemoresistant EOC stem cells surprisingly express higher levels of the pro-apoptotic members Bak and Bax compared to the chemosensitive EOC cells. In addition, whereas chemosensitive EOC cells preferentially express Bcl₂, chemoresistant EOC stem cells preferentially express Bcl_xl. In the EOC stem cells, 40% knock-down of Bcl_xl expression was sufficient to induce the full activation of caspases and this can be reversed by concurrent knock-down of Puma. More importantly, we demonstrate that Bcl_xl expression levels in EOC cells is dynamic and can be regulated by microenvironments that are enriched with the pro-inflammatory cytokine IL-6 such as the cancer stem cell and adipocyte niches. Adipocyte-induced upregulation of Bcl_xl correlated with acquisition of chemoresistance and thus demonstrates how a specific microenvironment can regulate the expression of apoptotic proteins and confer chemoresistance.

Deoxyschizandrin, Isolated from Schisandra Berries, Induces Cell Cycle Arrest in Ovarian Cancer Cells and Inhibits the Protumoural Activation of Tumour-Associated Macrophages

Deoxyschizandrin, a major lignan of Schisandra berries, has been demonstrated to have various biological activities such as antioxidant, hepatoprotective, and antidiabetic effects. However, the anti-cancer effects of deoxyschizandrin are poorly characterized. In the present study, we investigated the anti-cancer effect of deoxyschizandrin on human ovarian cancer cell lines and tumour-associated macrophages (TAMs). Deoxyschizandrin induced G₀/G₁ phase cell cycle arrest and inhibited cyclin E expression in human ovarian cancer cells. Overexpression of cyclin E significantly reversed the deoxyschizandrin-induced cell growth inhibition. Interestingly, increased production of reactive oxygen species and decreased activation of Akt were observed in A2780 cells treated with deoxyschizandrin, and the antioxidant compromised the deoxyschizandrin-induced cell growth inhibition and Akt inactivation. Moreover, deoxyschizandrin-induced cell growth inhibition was markedly suppressed by Akt overexpression. In addition, deoxyschizandrin was found to inhibit the expression of the M2 phenotype markers CD163 and CD209 in TAMs, macrophages stimulated by the ovarian cancer cells. Moreover, expression and production of the tumour-promoting factors MMP-9, RANTES, and VEGF, which are highly enhanced in TAMs, was significantly suppressed by deoxyschizandrin treatment. Taken together, these data suggest that deoxyschizandrin exerts anti-cancer effects by inducing G₀/G₁ cell cycle arrest in ovarian cancer cells and reducing the protumoural phenotype of TAMs.

The use of natural compounds for the targeting and chemoprevention of ovarian cancer

Among gynaecological cancers, ovarian cancer represents the leading cause of death in women. Current treatment for ovarian cancer entails surgery followed by combined chemotherapy with platinum and taxane, which are associated, particularly cisplatin, with severe side effects. While this treatment approach appears to be initially effective in a high number of patients, nearly 70% of them suffer a relapse within a few months after initial treatment. Therefore, more effective and better-tolerated treatment options are clearly needed. In recent years, several natural compounds (such as curcumin, epigallocatechin 3-gallate (EGCG), resveratrol, sulforaphane and Withaferin-A), characterized by long-term safety and negligible and/or inexistent side effects, have been proposed as possible adjuvants of traditional chemotherapy. Indeed, several in vitro and in vivo studies have shown that phytocompounds can effectively inhibit tumor cell proliferation, stimulate autophagy, induce apoptosis, and specifically target ovarian cancer stem cells (CSCs), which are generally considered to be responsible for tumor recurrence in several types of cancer. Here we review current literature on the role of natural products in ovarian cancer chemoprevention, highlighting their effects particularly on the regulation of inflammation, autophagy, proliferation and apoptosis, chemotherapy resistance, and ovarian CSC growth.

Revisiting ovarian cancer microenvironment: a friend or a foe?

Development of ovarian cancer involves the co-evolution of neoplastic cells together with the adjacent microenvironment. Steps of malignant progression including primary tumor outgrowth, therapeutic resistance, and distant metastasis are not determined solely by genetic alterations in ovarian cancer cells, but considerably shaped by the fitness advantage conferred by benign components in the ovarian stroma. As the dynamic cancer topography varies drastically during disease progression, heterologous cell types within the tumor microenvironment (TME) can actively determine the pathological track of ovarian cancer. Resembling many other solid tumor types, ovarian malignancy is nurtured by a TME whose dark side may have been overlooked, rather than overestimated. Further, harnessing breakthrough and targeting cures in human ovarian cancer requires insightful understanding of the merits and drawbacks of current treatment modalities, which mainly target transformed cells. Thus, designing novel and precise strategies that both eliminate cancer cells and manipulate the TME is increasingly recognized as a rational avenue to improve therapeutic outcome and prevent disease deterioration of ovarian cancer patients.

Influence of ovarian cancer type I and type II microenvironment on the phenotype and function of monocyte-derived dendritic cells

PURPOSE

The aim of this study was to evaluate the influence of ovarian cancer cell lysates isolated from type I or type II ovarian cancer (OC) on the phenotype of monocyte-derived dendritic cells (Mo-DCs) and the cytokine profile. We also determined whether the Mo-DCs and tumor microenvironment, reflected by peritoneal fluid (PF) from type I or II ovarian cancer, could promote regulatory T cell (Tregs) differentiation from naive CD4⁺ lymphocytes in vitro.

RESULTS

Our results show a significant role of the ovarian cancer microenvironment reflected by PF from type I or II OC in the inhibition of the DC differentiation process. Interestingly, the percentage of cells co-expressing CD45 and CD14 antigens in the cultures stimulated with PF from both type I and type II OC was higher than in the control. Furthermore, the percentage of cells expressing CD1a, i.e., a marker of immature DCs, was significantly reduced in the cultures stimulated with PF from type I and type II OC. The results obtained show that ovarian cancer type II lysates induce differentiation of monocytes into macrophage-like cells with a CD1a⁺/HLA-DR⁺/CD83⁻ phenotype and significantly higher CD86/HLA-DR expression. We show that ovarian cancer type II Mo-DCs are able to prevent an immune response by release of IL-10, whereas OC type I Mo-DCs can promote the generation of Tregs.

CONCLUSIONS

We demonstrate that each type of ovarian cancer can induce a unique phenotype of DCs and differentiation of Tregs, both associated with immune-suppressive function, which may be an obstacle while developing effective anticancer dendritic cell vaccination.

Interleukin 21 inhibits cancer-mediated FOXP3 induction in naïve human CD4 T cells

IL-21 is known to promote anti-tumour immunity due to its ability to promote T cell responses and counteract Treg-mediated suppression. It has also been shown to limit Treg frequencies during tumour-antigen stimulations. However, whether this represents inhibition of FOXP3 induction in naïve CD4 T cells or curtailed expansion of natural Treg remains unclear. Moreover, whether this effect is maintained in an environment of tumour-derived immunosuppressive factors is not known. Here, we show that in the context of a number of cancers, naïve CD45RA+ CD4 T cells are induced to express high levels of FOXP3, and that FOXP3 expression correlates with inhibition of T cell proliferation. FOXP3 expression was most potently induced by tumours secreting higher levels of total and active TGFβ1 and this induction could be potently counteracted with IL-21, restoring T cell proliferation. We conclude that Treg induction in naïve T cells is a common phenomenon amongst a number of different cancers and that the ability of IL-21 to counteract this effect is further evidence of its promise in cancer therapy.

Preoperative Monocyte-to-Lymphocyte Ratio in Peripheral Blood Predicts Stages, Metastasis, and Histological Grades in Patients with Ovarian Cancer

PURPOSE: The monocyte-to-lymphocyte ratio (MLR) has been shown to be associated with the prognosis of various solid tumors. This study sought to evaluate the important value of the MLR in ovarian cancer patients. METHODS: A total of 133 ovarian cancer patients and 43 normal controls were retrospectively reviewed. The patients' demographics were analyzed along with clinical and pathologic data. The counts of peripheral neutrophils, lymphocytes, monocytes, and platelets were collected and used to calculate the MLR, neutrophil-to-lymphocyte ratio (NLR). and platelet-to-lymphocyte ratio (PLR). The optimal cutoff value of the MLR was determined by using receiver operating characteristic curve analysis. We compared the MLR, NLR, and PLR between ovarian cancer and normal control patients and among patients with different stages and different grades, as well as between patients with lymph node metastasis and non–lymph node metastasis. We then investigated the value of the MLR in predicting the stage, grade, and lymph node positivity by using logistic regression. The impact of the MLR on overall survival (OS) was calculated by Kaplan-Meier method and compared by log-rank test. RESULTS: Statistically significant differences in the MLR were observed between ovarian cancer patients and normal controls. However, no difference was found for the NLR and PLR. Highly significant differences in the MLR were found among patients with different stages (stage I-II and stage III-IV), grades (G1 and >G1), and lymph node metastasis status. The MLR was a significant and independent risk factor for lymph node metastasis, as determined by logistic regression. The optimal cutoff value of the MLR was 0.23. We also classified the data according to tumor markers (CA125, CA199, HE4, AFP, and CEA) and conventional coagulation parameters (International Normalized Ratio [INR] and fibrinogen). Highly significant differences in CA125, CA199, HE4, INR, fibrinogen levels, and lactate dehydrogenase were found between the low-MLR group (MLR ≤ 0.23) and the high-MLR group (MLR > 0.23). Correspondingly, dramatic differences were observed between the two groups in OS. CONCLUSION: Our results show that the peripheral blood MLR before surgery could be a significant predictor of advanced stages, advanced pathologic grades, and positive lymphatic metastasis in ovarian cancer patients.

Minireview: Regulatory T Cells and Ovarian Cancer

In the last 15 years, it has become apparent that ovarian cancer is recognized by the immune system, taking into account that T cell infiltration can be associated with increased overall survival. Several studies indicate that a correct combination of cluster of differentiation 8 and cluster of differentiation 4 T cells is key to fight tumor progression and that the presence of regulatory T cells (Tregs) infiltrating ovarian solid tumors (or present in ascites) is deleterious. Several markers that characterize Tregs include glucocorticoid-induced tumor necrosis factor receptor, cytotoxic T lymphocyte antigen-4, and forkhead box protein 3 (Foxp3). Research has shown that Tregs can infiltrate cancerous tissue and contribute to tumor growth by secreting immunosuppressive cytokines such as transforming growth factor beta and interleukin (IL)-10. Importantly, these cells might hamper the efficacy of immunotherapeutic approaches, thus strategies involving depletion or regulation of this population have been proposed and tested in experimental models. In this Minireview, we will discuss the relevance of Tregs in ovarian cancer and the experimental approaches destined to impair their immunosuppressive effects.

[Immunological aspects of ovarian cancer: Therapeutic perspectives]

Ovarian cancer is recognized by the immunological system of its host. Initially, it is effective to destroy and eliminate the cancer. But gradually, resistant tumor cells more aggressive and those able to protect themselves by inducing immune tolerance will be selected. Immunotherapy to be effective should consider both components of immune response with an action on cytotoxic immune effectors and action on tolerance mechanisms. The manipulations of the immune system should be cautious, because the immune effects are not isolated. A theoretically efficient handling may simultaneously cause an adverse effect which was not envisaged and could neutralize the benefits of treatment. Knowledge of tolerance mechanisms set up by the tumor is for the clinician a prerequisite before they prescribe these treatments. For each cancer, the knowledge of its immunological status is a prerequisite to propose adapted immunological therapies.

TRX-E-002-1 Induces c-Jun-Dependent Apoptosis in Ovarian Cancer Stem Cells and Prevents Recurrence In Vivo

Chemoresistance is a major hurdle in the management of patients with epithelial ovarian cancer and is responsible for its high mortality. Studies have shown that chemoresistance is due to the presence of a subgroup of cancer cells with stemness properties and a high capacity for tumor repair. We have developed a library of super-benzopyran analogues to generate potent compounds that can induce cell death in chemoresistant cancer stem cells. TRX-E-002-1 is identified as the most potent analogue and can induce cell death in all chemoresistant CD44(+)/MyD88(+) ovarian cancer stem cells tested (IC50 = 50 nmol/L). TRX-E-002-1 is also potent against spheroid cultures formed from cancer stem cells, chemosensitive CD44(-)/MyD88(-) ovarian cancer cells, and heterogeneous cultures of ovarian cancer cells. Cell death was associated with the phosphorylation and increased levels of c-Jun and induction of caspases. In vivo, TRX-E-002-1 given as daily intraperitoneal monotherapy at 100 mg/kg significantly decreased intraperitoneal tumor burden compared with vehicle control. When given in combination with cisplatin, animals receiving the combination of cisplatin and TRX-E-002-1 showed decreased tumor burden compared with each monotherapy. Finally, TRX-E-002-1 given as maintenance treatment after paclitaxel significantly delayed disease recurrence. Our results suggest that TRX-E-002-1 may fill the current need for better therapeutic options in the control and management of recurrent ovarian cancer and may help improve patient survival. Mol Cancer Ther; 15(6); 1279-90. ©2016 AACR.

Secretion of cytokines and heat shock protein (HspA1A) by ovarian cancer cells depending on the tumor type and stage of disease

Epithelial ovarian cancer is a heterogeneous disease comprising several tumor types that each have multiple histopathological features and different biological behaviors. Recent morphologic and molecular genetic studies have allowed for the categorization of various types of ovarian cancer into two groups: type I and type II. Type I tumors are low-grade and are genetically more stable, while type II tumors are high-grade and genetically unstable. The determination of the type of ovarian cancer may have implications in terms of the appropriate therapeutic strategy because different prognoses and responses to chemotherapeutic agents are observed. Therefore, the current challenge is better recognition of the features of cancer cells, which may result in more individualized therapy. The aim of the current studies was to compare the ability of ovarian cancer cells isolated from tumors, which were classified as type I or type II ovarian cancer, to release pro-inflammatory and immunosuppressive cytokines and heat shock protein (HspA1A). These factors are known to facilitate tumor cell survival, invasion and metastasis. Our studies demonstrated that ovarian cancer cells isolated from patients with type II tumors released high levels of immunosuppressive cytokines (i.e., interleukin 10 and transforming growth factor β) and HspA1A in vitro. Conversely, ovarian cancer cells obtained from of type I tumors were significantly less active. We did not observe any difference in the ability of the isolated cancer cells to secrete pro-inflammatory cytokines, regardless of the type of ovarian cancer. In this study, we found that cancer cells from patients with type II tumors demonstrated more intense activity in regards to survival and metastasis, which should be considered during therapy.

Microenvironmental effects limit efficacy of thymoquinone treatment in a mouse model of ovarian cancer

Background

Ovarian cancer is the most lethal gynecologic malignancy, with limited treatment options for chemoresistant disease. An important link between inflammation and peritoneal spread of ovarian cancer is NF-κB signaling. Thymoquinone (TQ) exerts multiple anti-tumorigenic cellular effects, including NF-κB inhibition. We aimed to investigate the therapeutic potential of TQ in an established murine syngeneic model of ovarian cancer.

Methods

ID8-NGL mouse ovarian cancer cells stably expressing an NF-κB reporter transgene were injected intra-peritoneally into C57BL/6 mice, and mice were treated with TQ or vehicle for 10 or 30 days. TQ was combined with the macrophage depleting drug, liposomal clodronate, in selected experiments. Effects on peritoneal tumor burden were measured by volume of ascites, number of peritoneal implants and mesenteric tumor mass. NF-κB reporter activity and markers of proliferation and apoptosis were measured in tumors and in confirmatory in vitro experiments. Protein or mRNA expression of M1 (anti-tumor) and M2 (pro-tumor) macrophage markers, and soluble cytokine profiles, were examined from harvested ascites fluid, peritoneal lavages and/or tumor sections. 2-tailed Mann–Whitney tests were used for measuring differences between groups in in vivo experiments.

Results

Consistent with its effects in vitro, TQ reduced proliferation and increased apoptosis in ID8-NGL tumors after 10 and 30 day treatment. Prolonged TQ treatment did not significantly alter tumor number or mass compared to vehicle, but rather exerted an overall deleterious effect by stimulating ascites formation. Increased ascites was accompanied by elevated NF-κB activity in tumors and macrophages, increased pro-tumor M2 macrophages and expression of pro-tumorigenic soluble factors such as VEGF in ascites fluid, and increased tumor infiltration of M2 macrophages. In contrast, a 10 day exposure to TQ produced no ascites, and reduced tumor NF-κB activity, M2 macrophages and soluble VEGF levels. Peritoneal macrophage depletion by clodronate significantly reduced tumor burden. However, TQ-stimulated ascites was further enhanced by co-treatment with clodronate, with macrophages present overwhelmingly of the M2 phenotype.

Conclusions

Our findings show that pro-tumorigenic microenvironmental effects limited the efficacy of TQ in a syngeneic mouse model of ovarian cancer, and provide caution regarding its potential use in clinical trials in ovarian cancer patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s12943-015-0463-5) contains supplementary material, which is available to authorized users.

TWIST and ovarian cancer stem cells: implications for chemoresistance and metastasis

The transcription factor TWIST1 is a highly evolutionally conserved basic Helix-Loop-Helix (bHLH) transcription factor that functions as a master regulator of gastrulation and mesodermal development. Although TWIST1 was initially associated with embryo development, an increasing number of studies have shown TWIST1 role in the regulation of tissue homeostasis, primarily as a regulator of inflammation. More recently, TWIST1 has been found to be involved in the process of tumor metastasis through the regulation of Epithelial Mesenchymal Transition (EMT). The objective of this review is to examine the normal functions of TWIST1 and its role in tumor development, with a particular focus on ovarian cancer. We discuss the potential role of TWIST1 in the context of ovarian cancer stem cells and its influence in the process of tumor formation.

Multiple blocks in the engagement of oxidative phosphorylation in putative ovarian cancer stem cells: implication for maintenance therapy with glycolysis inhibitors

Survival rate in ovarian cancer has not improved since chemotherapy was introduced a few decades ago. The dismal prognosis is mostly due to disease recurrence where majority of the patients succumb to the disease. The demonstration that tumors are comprised of subfractions of cancer cells displaying heterogeneity in stemness potential, chemoresistance, and tumor repair capacity suggests that recurrence may be driven by the chemoresistant cancer stem cells. Thus to improve patient survival, novel therapies should eradicate this cancer cell population. We show that in contrast to the more differentiated ovarian cancer cells, the putative CD44+/MyD88+ ovarian cancer stem cells express lower levels of pyruvate dehydrogenase, Cox–I, Cox-II, and Cox–IV, and higher levels of UCP2. Together, this molecular phenotype establishes a bioenergetic profile that prefers the use of glycolysis over oxidative phosphorylation to generate ATP. This bioenergetic profile is conserved in vivo and therefore a maintenance regimen of 2-deoxyglucose administered after Paclitaxel treatment is able to delay the progression of recurrent tumors and decrease tumor burden in mice. Our findings strongly suggest the value of maintenance with glycolysis inhibitors with the goal of improving survival in ovarian cancer patients.

Trophoblast induces monocyte differentiation into CD14+/CD16+ macrophages

PROBLEM

During early pregnancy, macrophages and trophoblast come into close contact during placenta development, and regulated cross talk between these cellular compartments is crucial for maintaining a healthy pregnancy. As trophoblast cells constitutively secrete many chemokines and cytokines, we hypothesize that trophoblast-secreted factors can differentiate monocytes into a decidual phenotype. In this study, we describe a unique macrophage phenotype, following monocytes' exposure to trophoblast-soluble factors.

METHOD OF STUDY

Peripheral blood monocytes were treated with or without conditioned media (CM) from first trimester trophoblast cells. Phenotypic changes and phagocytic capacity were determined by flow cytometry. Cytokine and chemokine production was determined by multiplex analysis.

RESULTS

Monocytes exposed to trophoblast factors undergo morphologic changes characterized by a gain in size and complexity and acquire a unique phenotype characterized by gain of CD14 surface expression as well as CD16. The presence of CD14+/CD16+ macrophages was confirmed in normal decidua. These cells secrete higher levels of IL-1b, IL-10, and IP-10 and have increased capacity for phagocytosis.

CONCLUSION

We demonstrate that trophoblast-secreted factors can induce monocyte differentiation into a unique macrophage phenotype. These findings suggest that the microenvironment of the placenta can modulate the phenotype of macrophages present at the decidua.

Ovulation and extra-ovarian origin of ovarian cancer

The mortality rate of ovarian cancer remains high due to late diagnosis and recurrence. A fundamental step toward improving detection and treatment of this lethal disease is to understand its origin. A growing number of studies have revealed that ovarian cancer can develop from multiple extra-ovarian origins, including fallopian tube, gastrointestinal tract, cervix and endometriosis. However, the mechanism leading to their ovarian localization is not understood. We utilized in vitro, ex vivo, and in vivo models to recapitulate the process of extra-ovarian malignant cells migrating to the ovaries and forming tumors. We provided experimental evidence to support that ovulation, by disrupting the ovarian surface epithelium and releasing chemokines/cytokines, promotes the migration and adhesion of malignant cells to the ovary. We identified the granulosa cell-secreted SDF-1 as a main chemoattractant that recruits malignant cells towards the ovary. Our findings revealed a potential molecular mechanism of how the extra-ovarian cells can be attracted by the ovary, migrate to and form tumors in the ovary. Our data also supports the association between increased ovulation and the risk of ovarian cancer. Understanding this association will lead us to the development of more specific markers for early detection and better prevention strategies.

Tumor-associated macrophages contribute to tumor progression in ovarian cancer

Ovarian cancer is the leading cause of death in women with gynecological malignancy and improvements in current treatments are needed. As with many other solid cancers, the ovarian tumor microenvironment is emerging as a key player in tumor progression and a potential therapeutic target. The tumor microenvironment contains several non-malignant cell types that are known to contribute to tumor progression and metastasis. Included in this population of non-malignant cells are several different types of immune cells, of which tumor-associated macrophages (TAMs) are the most abundant. An increasing amount of evidence is emerging to suggest that TAMs display a unique activation profile in ovarian tumors and are able to create an immunosuppressive microenvironment, allowing tumors to evade immune detection and promoting tumor progression. Therefore, an increased understanding of how these immune cells interact with tumor cells and the microenvironment will greatly benefit the development of more effective immunotherapies to treat ovarian cancer. This review focuses on the role of TAMs in the ovarian tumor microenvironment and how they promote tumor progression.

The therapeutic potential of class I selective histone deacetylase inhibitors in ovarian cancer

Epithelial ovarian cancer remains the deadliest gynecologic malignancy. Despite advances in treatment, new approaches are needed. Histone deacetylases (HDACs) are a family of enzymes that regulate gene expression by removing acetyl groups from lysine residues on histones and non-histone proteins. Inhibition of HDACs with small molecules has led to the development of histone deacetylase inhibitors (HDACi) that are in clinical use, primarily for hematologic malignancies. Although clinical trials with HDACi as single agents in solid tumors have been disappointing, data from independent labs and recent work by our group show that class I selective HDACi have potent anti-tumor effects in pre-clinical models of ovarian cancer. This review summarizes the role of HDACs in ovarian cancer and the potential niche for selective class I HDACi, particularly HDAC3 in ovarian cancer therapy.

Tracking NF-κB activity in tumor cells during ovarian cancer progression in a syngeneic mouse model

Background

Nuclear factor-kappa B (NF-kappaB) signaling is an important link between inflammation and peritoneal carcinomatosis in human ovarian cancer. Our objective was to track NF-kappaB signaling during ovarian cancer progression in a syngeneic mouse model using tumor cells stably expressing an NF-kappaB reporter.

Methods

ID8 mouse ovarian cancer cells stably expressing an NF-kappaB-dependent GFP/luciferase (NGL) fusion reporter transgene (ID8-NGL) were generated, and injected intra-peritoneally into C57BL/6 mice. NGL reporter activity in tumors was non-invasively monitored by bioluminescence imaging and measured in luciferase assays in harvested tumors. Ascites fluid or peritoneal lavages were analyzed for inflammatory cell and macrophage content, and for mRNA expression of M1 and M2 macrophage markers by quantitative real-time RT-PCR. 2-tailed Mann-Whitney tests were used for measuring differences between groups in in vivo experiments.

Results

In ID8-NGL cells, responsiveness of the reporter to NF-kappaB activators and inhibitors was confirmed in vitro and in vivo. ID8-NGL tumors in C57BL/6 mice bore histopathological resemblance to human high-grade serous ovarian cancer and exhibited similar peritoneal disease spread. Tumor NF-kappaB activity, measured by the NGL reporter and by western blot of nuclear p65 expression, was markedly elevated at late stages of ovarian cancer progression. In ascites fluid, macrophages were the predominant inflammatory cell population. There were elevated levels of the M2-like pro-tumor macrophage marker, mannose-receptor, during tumor progression, and reduced levels following NF-kappaB inhibition with thymoquinone.

Conclusions

Our ID8-NGL reporter syngeneic model is suitable for investigating changes in tumor NF-kappaB activity during ovarian cancer progression, how NF-kappaB activity influences immune cells in the tumor microenvironment, and effects of NF-kappaB-targeted treatments in future studies.

Effect of culture conditions on the phenotype of THP-1 monocyte cell line

PROBLEM

Macrophage function has many implications in a variety of diseases. Understanding their biology becomes imperative when trying to elucidate immune cell interactions with their environment, and in vitro cell lines allow researchers to manipulate these interactions. A common cell line used is THP-1, a promyeloid cell line suggestive to outside factors, and therefore sensitive to culture conditions. In this study, we describe how culture conditions can alter THP-1 morphology and in turn affect their response to differentiation stimuli.

METHOD OF STUDY

THP-1 cells were cultured in two conditions and treated with phorbol 12-myristate 13-acetate (PMA) or MCSF. CD14 surface expression was determined by flow cytometry and cytokine/chemokine production determined by multiplex analysis.

RESULTS

Culture conditions of THP-1 affect their response to PMA. Highly confluent THP-1 cells differentiate into a heterogeneous population responsive to PMA as seen by an increase in CD14 expression. However, these cells, cultured in low confluence, remain as a homogenous population and do not gain CD14. Additionally, there are major differences in the constitutive cytokine profile.

CONCLUSION

We demonstrate that the culture conditions of THP-1 cells can alter their response PMA. This suggests that culture techniques may account for the discrepancy in the literature of both basal THP-1 phenotype and their response to PMA.

The analysis of metallothionein immunoreactivity in stromal fibroblasts and macrophages in cases of uterine cervical carcinoma with respect to both the local and distant spread of the disease

PROBLEM

The tumor microenvironment is made up of tissue that is responsible for the growth and progression of the tumor as well as its ability to initiate metastases. The cancer cells on the front of the tumor together with the macrophages and fibroblasts help to constitute the aggressive phenotype of the tumor. The presence of this aggressive phenotype is indicated by the local infiltration of cancer cells and by the development of lymph node metastases. In cases of uterine cancer, the extent of the local and distant spread of the disease is crucial for determining the type of therapeutic strategy to be applied - surgery alone, surgery followed by radio-chemotherapy, or radio-chemotherapy alone. In the interest of trying to improve the patient's quality of life, different studies supporting the therapeutic model of surgery alone have been conducted. While the cancer cells on the tumor front together with the macrophages and the fibroblasts help to constitute the aggressive phenotype of the tumor, metallothionein (MT) has been shown to have both pro-proliferative and anti-apoptotic activities and to participate in microenvironment remodeling. The aim of the current study was to determine the levels of MT immunoreactivity in the uterine cervical cancer cells as well as in the stromal fibroblasts and macrophages of the tumor microenvironment with respect to the depth of the local invasion and the extent of the distant metastases, so that its potential predictive value as a therapeutic strategy for cervical cancer can be ascertained.

METHODS

We determined the levels of immunoreactivity of MT in a total of 57 carcinoma tissue samples (in the tumor front, in its central part, and in the macrophages and fibroblasts present within the tumor microenvironment). The patients from whom the samples derived were divided into groups with respect to the presence of lymph node metastases (distant spread) and to the depth of invasion (local spread) in relation to the FIGO stage.

RESULTS

Metallothionein immunoreactivity was observed in uterine cervical cancer cells; it was also identified in the fibroblasts and macrophages found within the microenvironments of the tumors of patients suffering from the disease. The MT immunoreactivity level significantly increased within the whole cancer nest in relation to the FIGO stage (intensity of the local spread of the disease). Similarly, the infiltration of MT-positive CAFs and TAMs statistically significantly increased in relation to the FIGO stage.

CONCLUSION

The level of MT immunoreactivity found in the fibroblasts and macrophages within the tumor microenvironment seems to be indicative of the intensity of the remodeled cervical tumor microenvironment, and this in turn may be related to the local advancement of the disease. Moreover, it appears that the intensity of the metallothionein immunoreactivity in the immunoreactivity profile of the cervical tumor may be linked to both the depth of the local invasion and the extent of the distant advancement of the disease.

Interaction of monocytes/macrophages with ovarian cancer cells promotes angiogenesis in vitro

It has been established that macrophages and endothelial cells infiltrate peritoneum in the vicinity of tumor implants of epithelial ovarian cancer (EOC). This study investigates whether the interaction of ovarian cancer cells and tumor-associated macrophages could promote the involvement of endothelial cells in angiogenesis. Macrophage phenotypes were detected by fluorescence-activated cell sorting, and cytokine/chemokine secretion was measured by enzyme linked immunosorbent assay. The effect of co-culture of ovarian cancer cells and tumor-associated macrophage (TAM) cells on endothelial cell migration and tube formation was investigated. Signaling pathway mediators were also evaluated for their potential roles in endothelial cell activation by ovarian cancer cells co-cultured with TAM cells. Our results showed that higher expression of interleukin-8 (IL-8) expression associated with 54.26 ± 34.46% of TAM infiltration of peritoneum was significantly higher than 16.58 ± 17.74% of CD3(+) T-cell by immunofluorescence co-staining and confocal microscopy. THP-1 cells exhibited M2-polarized phenotype markers with high proportion of CD68(+) , CD206(+) and CD204(+) markers after phorbol 12-myristate 13-acetate (PMA) treatment, After co-culturing with TAM cells in a transwell chamber system, EOC cells (SKOV3) increased their IL-8 expression at the level of mRNA and protein. After exposure to the conditioned medium obtained by co-culturing TAM and SKOV3 cells, the migration and tube formation of endothelial cells were enhanced significantly. Furthermore, the upregulation of IL-8 expression in ovarian cancer cells induced by macrophages could be inhibited by pyrollidine dithiocarbamate, an inhibitor of nuclear factor (NF)- κB signal pathway. We suggest that the interaction of ovarian cancer cells and tumor-associated macrophages enhances the ability of endothelial cells to promote the progression of ovarian cancer.

TLR2 enhances ovarian cancer stem cell self-renewal and promotes tumor repair and recurrence

Primary ovarian cancer is responsive to treatment, but chemoresistant recurrent disease ensues in majority of patients. Recent compelling evidence demonstrates that a specific population of cancer cells, the cancer stem cells, initiates and sustains tumors. It is therefore possible that this cell population is also responsible for recurrence. We have shown previously that CD44+/MyD88+ epithelial ovarian cancer stem cells (CD44+/MyD88+ EOC stem cells) are responsible for tumor initiation. In this study, we demonstrate that this population drives tumor repair following surgery- and chemotherapy-induced tumor injury. Using in vivo and in vitro models, we also demonstrate that during the process of tumor repair, CD44+/MyD88+ EOC stem cells undergo self-renewal as evidenced by upregulation of stemness-associated genes. More importantly, we show that a pro-inflammatory microenvironment created by the TLR2-MyD88-NFκB pathway supports EOC stem cell-driven repair and self-renewal. Overall, our findings point to a specific cancer cell population, the CD44+/MyD88+ EOC stem cells and a specific pro-inflammatory pathway, the TLR2-MyD88-NFκB pathway, as two of the required players promoting tumor repair, which is associated with enhanced cancer stem cell load. Identification of these key players is the first step in elucidating the steps necessary to prevent recurrence in EOC patients.

The duplicitous origin of ovarian cancer

The past few decades have seen many advances in the treatment of a variety of cancers. Unfortunately, for ovarian cancer, which is the most lethal type of gynecologic malignancy, no new therapeutic approach has been successfully introduced since the 1990s. Ovarian cancer is usually detected in later stages, when remission rates are high and tumors are resistant to chemotherapy. Little is known about the primary lesion in ovarian cancer. Recently, it has been shown that the origin of ovarian cancer can be cells from adjacent tissue or cells from other primary tumors, which make their way to the ovaries due to the unique nature of their microenvironment during ovulation. The tumor in ovarian cancer is heterogeneous and hierarchically organized. In this review, we discuss the role of ovarian cancer stem cells in the process of tumor formation and recurrence. We propose the need to shift the paradigm away from the classification of ovarian cancer as a single disease with a single cellular origin. Understanding the complexity of the disease will facilitate devising new methods for fighting this cancer and improving the life of many women inflicted with the disease.

[Immunological analogies between ovarian cancer and pregnancy]

During pregnancy an environment allowing installation of tolerance toward the fetus is set up locally at the materno-fetal interface. Numerous effectors of immunity are involved in this tolerance (NK cell, T cell, Macrophages, dendritic cell). Specific mechanisms during pregnancy attract locally these immunological cells. In the decidua, they are educated toward tolerance. These mechanisms evolve during the pregnancy because at the end of the pregnancy, tolerance is broken to prepare and activate the labor. Ovarian tumors, after having surmounted the immunosurveillance, like trophoblast, chair the installation of a tolerance of their host facilitating the development of the disease. The blocking of these mechanisms of tolerance coupled with activation of mechanisms of defenses offer new perspectives in the treatment of the ovarian cancer. The authors suggest showing the analogies of the tolerance observed during ovarian cancer and pregnancy. The knowledge of the orchestration of the physiological mechanisms observed during pregnancy will offer new therapeutic targets.

Involvement of autophagy in ovarian cancer: a working hypothesis

Autophagy is a lysosomal-driven catabolic process that contributes to preserve cell and tissue homeostases through the regular elimination of damaged, aged and redundant self-constituents. In normal cells, autophagy protects from DNA mutation and carcinogenesis by preventive elimination of pro-oxidative mitochondria and protein aggregates. Mutations in oncogenes and oncosuppressor genes dysregulate autophagy. Up-regulated autophagy may confer chemo- and radio-resistance to cancer cells, and also a pro-survival advantage in cancer cells experiencing oxygen and nutrient shortage. This fact is the rationale for using autophagy inhibitors along with anti-neoplastic therapies. Yet, aberrant hyper-induction of autophagy can lead to cell death, and this phenomenon could also be exploited for cancer therapy. The actual level of autophagy in the cancer cell is greatly affected by vascularization, inflammation, and stromal cell infiltration. In addition, small non-coding microRNAs have recently emerged as important epigenetic modulators of autophagy. The present review focuses on the potential involvement of macroautophagy, and on its genetic and epigenetic regulation, in ovarian cancer pathogenesis and progression.

Peripheral blood immune cell methylation profiles are associated with nonhematopoietic cancers

BACKGROUND

Blood leukocytes from patients with solid tumors exhibit complex and distinct cancer-associated patterns of DNA methylation. However, the biologic mechanisms underlying these patterns remain poorly understood. Because epigenetic biomarkers offer significant clinical potential for cancer detection, we sought to address a mechanistic gap in recently published works, hypothesizing that blood-based epigenetic variation may be due to shifts in leukocyte populations.

METHODS

We identified differentially methylated regions (DMR) among leukocyte subtypes using epigenome-wide DNA methylation profiling of purified peripheral blood leukocyte subtypes from healthy donors. These leukocyte-tagging DMRs were then evaluated using epigenome-wide blood methylation data from three independent case-control studies of different cancers.

RESULTS

A substantial proportion of the top 50 leukocyte DMRs were significantly differentially methylated among head and neck squamous cell carcinoma (HNSCC) cases and ovarian cancer cases compared with cancer-free controls (48 and 47 of 50, respectively). Methylation classes derived from leukocyte DMRs were significantly associated cancer case status (P < 0.001, P < 0.03, and P < 0.001) for all three cancer types: HNSCC, bladder cancer, and ovarian cancer, respectively and predicted cancer status with a high degree of accuracy (area under the curve [AUC] = 0.82, 0.83, and 0.67).

CONCLUSIONS

These results suggest that shifts in leukocyte subpopulations may account for a considerable proportion of variability in peripheral blood DNA methylation patterns of solid tumors.

IMPACT

This illustrates the potential use of DNA methylation profiles for identifying shifts in leukocyte populations representative of disease, and that such profiles may represent powerful new diagnostic tools, applicable to a range of solid tumors.