Harnessing tumor angiogenesis to explore ovarian cancer immune suppression and address target-therapies outcomes

In 2020, ovarian cancer still remains the "Biggest Enemy" faced by Gynecology Oncologists, due to the lack of biological and clinical tools for early diagnosis, high recurrence rates despite the recent introduction of targeted-therapies for the management of advanced disease, and 5-year overall survival below 40%. In particular, high grade serous ovarian cancer (HGSOC), recently classified as a Type II ovarian carcinoma, still accounts alone for the 80% of all ovarian cancer deaths. In light of these numbers and to the urgent need to reduce mortality from high grade serous ovarian cancer, in 2015 an international group of opinion leaders summarized a comprehensive list of priority issues which are still considered as “unmet needs” in the understanding of high grade serous ovarian cancer. Among these issues, the Authors identify the following biological landscapes to be explored for HGSOC patients’s future prognosis change: 1) to exploit HGSOC patients’ immune response and interaction between host immune system and tumor microenvironment; 2) to analyse recurrent and end-stage disease samples, in order to shed light on acquired resistance mechanisms; 3) to integrate all –omics data on individual samples with immune and other tumor microenvironment components in primary and recurrent samples. As a consequence, the research work carried out during this international PhD programme, and here discussed, aimed to add answers to these universally recognized priority issues in ovarian cancer understanding. In particular, the leading research line developed and carried out aimed to explore the modulation of tumor-derived neoangiogenesis during ovarian cancer progression and the role of anti-angiogenetic agents in reverting tumor immune suppressive circuit thus triggering host’s anti-tumoral immunological response. The 3 research studies here presented* were both carried out in the context of the “OCTIPS Consortium”, a 7th Framework Program research Project, funded by the European Commission in 2012, which currently holds in its biobank at Charité Medical University (Berlin, Germany) one of the largest European collection of paired primary and recurrent ovarian cancers samples; and in the context of the “Laboratory of Tumor Immunology and Cell therapy Unit“ directed by Prof. Marianna Nuti, at Sapienza University (Rome, Italy).Im Jahr 2020, bleibt das Ovarialkarzinom noch der schlimmste der gyneco onkologische Erkrankungen wegen diesen Gruenden: 1. Fehlen einer wirksamen screeing Methode 2. hohe Rezidivrate, trotz der neuen “Target therapies” fuer die fortgeschrittenen Stadien dieser Krankheit 3. kurzes 5-Jahren gesamt-Ueberleben (<40%) Bei dem fortgeschrittenen seroesen Eierstockkrebs (high grade serous ovarian cancer, HGSOC), kuerzlich genauso bekannt wie “Ovarialkarzinoma Typ II”, liegt die Sterblichkeit bei 80% unter allen Todesfaelle vom Ovarialkarzinom. Im Jahr 2015, ist eine Liste von unbeantworteten Schwerpunkten in Ovarialkarzinoma von einer Internationalen Expertengruppe erstellt worden. Zu diesem Ziel, konzentrieren sich die Autoren auf den biologischen Hintergrund von HGSOC, wie folgt: 1) Beziehung zwischen die Tumor-Mikroumgebung und das Immunsystem 2) Gewebeanalysen zur Bestimmung von neu aufgetretenen Resistenz Mechanism 3) Integration mit omics Daten von Proben mit immunologische und andere Tumor mivroinironment Komponenten. Demensprechend ist die Forschung die waehrend diesem internationalen Phd Programm durchgefuehrt wurde, und hier discutiert wird, zur Vorstellung von Antworten zu diesen prioritaeren Fragestellungen zum Verstaendnis vom Ovarialkarzinom gerichtet. Die folgende Forschungslinien wurden entwickelt: Untersuchung der Modulation von der Tumor gesteuerte Neoangiogenese zur Zeit der Progession von Ovarialkarzinom und von der Rolle die von den antiagiogenteischen Medikamenten in der Aenderung der Tumor assoziierte immunologische Hemmung spielen. Die 3 Studien die hier vorgestellt werden* sind im Rahmen von dem “OCTIPS Consortium” einen Forschungsprojeckt der von der Europaeische Kommission 2012 finanziert wurde, durchgefuehrt worden. Die Biobank vom OPTICS Consortium ist einer der groessten in Europa und enthaelt Proben von Ovarialkarzinome zur Zeit der Diagnose sowie zur Zeit vom Rezidiv und befindet sich an der Charite’ Medical University (Berlin, Germany). Zusaetzlich hat es eine Kollaboration mit dem Laboratory of Tumor Immunology and Cell therapy Unit“ unter der Leitung von Frau Prof. Marianna Nuti, an der Universitaet Sapienza (Rom, Italien) gegeben

Tumor-derived microvesicles modulate antigen cross-processing via reactive oxygen species-mediated alkalinization of phagosomal compartment in dendritic cells

Dendritic cells (DCs) are the only antigen-presenting cells able to prime naïve T cells and cross-prime antigen-specific CD8+ T cells. Their functionality is a requirement for the induction and maintenance of long-lasting cancer immunity. Albeit intensively investigated, the in vivo mechanisms underlying efficient antigen cross-processing and presentation are not fully understood. Several pieces of evidence indicate that antigen transfer to DCs mediated by microvesicles (MVs) enhances antigen immunogenicity. This mechanism is also relevant for cross-presentation of those tumor-associated glycoproteins such as MUC1 that are blocked in HLA class II compartment when internalized by DCs as soluble molecules. Here, we present pieces of evidence that the internalization of tumor-derived MVs modulates antigen-processing machinery of DCs. Employing MVs derived from ovarian cancer ascites fluid and established tumor cell lines, we show that MV uptake modifies DC phagosomal microenvironment, triggering reactive oxygen species (ROS) accumulation and early alkalinization. Indeed, tumor MVs carry radical species and the MV uptake by DCs counteracts the chemically mediated acidification of the phagosomal compartment. Further pieces of evidence suggest that efficacious antigen cross-priming of the MUC1 antigen carried by the tumor MVs results from the early signaling induced by MV internalization and the function of the antigen-processing machinery of DCs. These results strongly support the hypothesis that tumor-derived MVs impact antigen immunogenicity by tuning the antigen-processing machinery of DCs, besides being carrier of tumor antigens. Furthermore, these findings have important implications for the exploitation of MVs as antigenic cell-free immunogen for DC-based therapeutic strategies

Tumor derived Microvesicles enhance cross-processing ability of clinical grade Dendritic Cells

Tumor cells release extracellular microvesicles (MVs) in the microenvironment to deliver biological signals to neighbouring cells as well as to cells in distant tissues. Tumor-derived MVs appear to play contradictory role promoting both immunosuppression and tumor growth and both evoking tumor specific immune response. Recent evidences indicate that tumor-derived MVs can positively impact Dendritic Cells (DCs) immunogenicity by reprogramming DC antigen processing machinery and intracellular signaling pathways, thus promoting anti-tumor response. DCs are considered pivot cells of the immune system due to their exclusive ability to coordinate the innate and acquired immune responses, cross-present exogenous antigens and prime naïve T cells. DCs are required for the induction and maintenance of long-lasting anti-tumor immunity and their exploitation has been extensively investigated for the design of anti-tumor vaccines. However, the clinical grade culture conditions that are required to generate DCs for therapeutic use can strongly affect their functions. Here, we investigated the immunomodulatory impact of MVs carrying the MUC1 tumor glycoantigen (MVsMUC1) as immunogen formulation on clinical grade DCs grown in X-VIVO 15 (X-DCs). Results indicated that X-DCs displayed reduced performance of the antigen processing machinery in term of diminished phagocytosis and acidification of the phagosomal compartment suggesting an altered immunogenicity of clinical grade DCs. Pulsing DCs with MVsMUC1 restored phagosomal alkalinization, triggering ROS increase. This was not observed when a soluble MUC1 protein was employed (rMUC1). Concurrently, MVsMUC1 internalization by X-DCs allowed MUC1 cross-processing. Most importantly, MVsMUC1 pulsed DCs activated IFNγ response mediated by MUC1 specific CD8+ T cells. These results strongly support the employment of tumor-derived MVs as immunogen platforms for the implementation of DC-based vaccine

PARP inhibition: a promising therapeutic target in ovarian cancer

Ovarian cancer is burdened by the highest mortality rate among gynecological cancers. Gold standard is represented by the association of platinum-taxane -based chemotherapy and radical surgery. Despite several adjustments occurred in cytotoxic drug in last decades, most patients continue to relapse, and no significant enhancement has been reached in the overall survival. The development of drug resistance and the recurrence of disease have prompted the investigations of other targets that can be used in the treatment of ovarian cancers. Among such targets, polyadenosine diphosphate-ribose polymerase (PARP) represents a novel way to target specific patways involved in tumor growth. PARP accelerates the reaction of the polyADP-ribosylation of proteins implicated in DNA repair. PARP inhibitors have shown activity in cancers with BRCA mutations, with other deficient DNA repair genes or signaling pathways that modulate DNA repair, or in association with DNA damaging agents not involved in DNA repair dysfunction. A number of inhibitors for PARP has been developed, and such drugs are under investigation in clinical trials to identify their impact in the treatment of ovarian cancers. This review aims to summarize the recent researches and clinical progress on PARP inhibitors as novel target agents in ovarian cancer

Triple peptide vaccination as consolidation treatment in women affected by ovarian and breast cancer: clinical and immunological data of a phase I/II clinical trial

Vaccination with priming and expansion of tumour reacting T cells is an important therapeutic option to be used in combination with novel checkpoint inhibitors to increase the specificity of the T cell infiltrate and the efficacy of the treatment. In this phase I/II study, 14 high-risk disease-free ovarian (OC) and breast cancer (BC) patients after completion of standard therapies were vaccinated with MUC1, ErbB2 and carcinoembryonic antigen (CEA) HLA-A2+-restricted peptides and Montanide. Patients were subjected to 6 doses of vaccine every two weeks and a recall dose after 3 months. ECOG grade 2 toxicity was observed at the injection site. Eight out of 14 patients showed specific CD8+ T cells to at least one antigen. None of 4 patients vaccinated for compassionate use showed a CD8 activation. An OC patient who suffered from a lymph nodal recurrence, showed specific anti-ErbB2 CD8+ T cells in the bulky aortic lymph nodes suggesting homingof the activated T cells. Results confirm that peptide vaccination strategy is feasible, safe and well tolerated. In particular OC patients appear to show a higher response rate compared to BC patients. Vaccination generates a long-lasting immune response, which is strongly enhanced by recall administrations. The clinical outcome of patients enrolled in the trial appears favourable, having registered no deceased patients with a minimum follow-up of 8 years. These promising data, in line with the results of similar studies, the high compliance of patients observed and the favourable toxicity profile, support future trials of peptide vaccination in clinically disease-free patients who have completed standard treatments

Monoclonal Antibodies in Gynecological Cancer: A Critical Point of View

During the last decades, several improvements in treating gynecological malignancies have been achieved. In particular, target therapies, mostly monoclonal antibodies, have emerged as an attractive option for the treatment of these malignancies. In fact, various molecular-targeted agents have been developed for a variety of malignancies with the objective to interfere with a precise tumor associated receptor, essential for cancer cell survival or proliferation, blocking its function, of the cancer cells. Alternatively, monoclonal antibodies have been developed to block immune suppression or enhance functions of immune effector cells. So far, several monoclonal antibodies have been tested for clinical efficacy for the treatment of gynecological cancers. Antibodies against Vascular Endothelial Growth Factor (VEGF) and Epidermal Growth Factor Receptor (EGFR) have been used in different neoplasms such as ovarian and cervical cancer. Catumazumab, a bivalent antibody against CD3 and EpCAM, is effective in the treatment of neoplastic ascites. Other antibodies are peculiar for specific cancer-associated antigen such as Oregovomab against CA125 or Farletuzumab against the folate receptor. Here we describe the preclinical and clinical experience gained up to now with monoclonal antibodies in tumors of the female genital tract and trace future therapeutic and research venues

Tumor-Derived Microvesicles Enhance Cross-Processing Ability of Clinical Grade Dendritic Cells

Tumor cells release extracellular microvesicles (MVs) in the microenvironment to deliver biological signals to neighboring cells as well as to cells in distant tissues. Tumor-derived MVs appear to play contradictory role promoting both immunosuppression and tumor growth and both evoking tumor specific immune response. Recent evidences indicate that tumor-derived MVs can positively impact Dendritic Cells (DCs) immunogenicity by reprogramming DC antigen processing machinery and intracellular signaling pathways, thus promoting anti-tumor response. DCs are considered pivot cells of the immune system due to their exclusive ability to coordinate the innate and acquired immune responses, cross-present exogenous antigens, and prime naïve T cells. DCs are required for the induction and maintenance of long-lasting anti-tumor immunity and their exploitation has been extensively investigated for the design of anti-tumor vaccines. However, the clinical grade culture conditions that are required to generate DCs for therapeutic use can strongly affect their functions. Here, we investigated the immunomodulatory impact of MVs carrying the MUC1 tumor glycoantigen (MVsMUC1) as immunogen formulation on clinical grade DCs grown in X-VIVO 15 (X-DCs). Results indicated that X-DCs displayed reduced performance of the antigen processing machinery in term of diminished phagocytosis and acidification of the phagosomal compartment suggesting an altered immunogenicity of clinical grade DCs. Pulsing DCs with MVsMUC1 restored phagosomal alkalinization, triggering ROS increase. This was not observed when a soluble MUC1 protein was employed (rMUC1). Concurrently, MVsMUC1 internalization by X-DCs allowed MUC1 cross-processing. Most importantly, MVsMUC1 pulsed DCs activated IFNγ response mediated by MUC1 specific CD8+ T cells. These results strongly support the employment of tumor-derived MVs as immunogen platforms for the implementation of DC-based vaccines

Exploring the clonal evolution of CD133/aldehyde-dehydrogenase-1 (ALDH1)-positive cancer stem-like cells from primary to recurrent high-grade serous ovarian cancer (HGSOC). A study of the Ovarian Cancer Therapy–Innovative Models Prolong Survival (OCTIPS) Consortium

Background High-grade serous ovarian cancer (HGSOC) causes 80% of all ovarian cancer (OC) deaths. In this setting, the role of cancer stem-like cells (CSCs) is still unclear. In particular, the evolution of CSC biomarkers from primary (pOC) to recurrent (rOC) HGSOCs is unknown. Aim of this study was to investigate changes in CD133 and aldehyde dehydrogenase-1 (ALDH1) CSC biomarker expression in pOC and rOC HGSOCs. Methods Two-hundred and twenty-four pOC and rOC intrapatient paired tissue samples derived from 112 HGSOC patients were evaluated for CD133 and ALDH1 expression using immunohistochemistry (IHC); pOCs and rOCs were compared for CD133 and/or ALDH1 levels. Expression profiles were also correlated with patients' clinicopathological and survival data. Results Some 49.1% of the patient population (55/112) and 37.5% (42/112) pOCs were CD133+ and ALDH1+ respectively. CD133+ and ALDH1+ samples were detected in 33.9% (38/112) and 36.6% (41/112) rOCs. CD133/ALDH1 coexpression was observed in 23.2% (26/112) and 15.2% (17/112) of pOCs and rOCs respectively. Pairwise analysis showed a significant shift of CD133 staining from higher (pOCs) to lower expression levels (rOCs) (p < 0.0001). Furthermore, all CD133 + pOC patients were International Federation of Gynaecology and Obstetrics (FIGO)-stage III/IV (p < 0.0001) and had significantly worse progression-free interval (PFI) (p = 0.04) and overall survival (OS) (p = 0.02). On multivariate analysis, CD133/ALDH1 coexpression in pOCs was identified as independent prognostic factor for PFI (HR: 1.64; 95% CI: 1.03–2.60; p = 0.036) and OS (HR: 1.71; 95% CI: 1.01–2.88; p = 0.045). Analysis on 52 pts patients with known somatic BRCA status revealed that BRCA mutations did not influence CSC biomarker expression. Conclusions The study showed that CD133/ALDH1 expression impacts HGSOC patients' survival and first suggests that CSCs might undergo phenotypic change during the disease course similarly to non stem-like cancer cells, providing also a first evidence that there is no correlation between CSCs and BRCA status

Impact of BRCA Mutation Status on Tumor Dissemination Pattern, Surgical Outcome and Patient Survival in Primary and Recurrent High-Grade Serous Ovarian Cancer:A Multicenter Retrospective Study by the Ovarian Cancer Therapy-Innovative Models Prolong Survival (OCTIPS) Consortium

Background: This study seeks to evaluate the impact of breast cancer (BRCA) gene status on tumor dissemination pattern, surgical outcome and survival in a multicenter cohort of paired primary ovarian cancer (pOC) and recurrent ovarian cancer (rOC). Patients and Methods: Medical records and follow-up data from 190 patients were gathered retrospectively. All patients had surgery at pOC and at least one further rOC surgery at four European high-volume centers. Patients were divided into one cohort with confirmed mutation for BRCA1 and/or BRCA2 (BRCAmut) and a second cohort with BRCA wild type or unknown (BRCAwt). Patterns of tumor presentation, surgical outcome and survival data were analyzed between the two groups. Results: Patients with BRCAmut disease were on average 4 years younger and had significantly more tumor involvement upon diagnosis. Patients with BRCAmut disease showed higher debulking rates at all stages. Multivariate analysis showed that only patient age had significant predictive value for complete tumor resection in pOC. At rOC, however, only BRCAmut status significantly correlated with optimal debulking. Patients with BRCAmut disease showed significantly prolonged overall survival (OS) by 24.3 months. Progression-free survival (PFS) was prolonged in the BRCAmut group at all stages as well, reaching statistical significance during recurrence. Conclusions: Patients with BRCAmut disease showed a more aggressive course of disease with earlier onset and more extensive tumor dissemination at pOC. However, surgical outcome and OS were significantly better in patients with BRCAmut disease compared with patients with BRCAwt disease. We therefore propose to consider BRCAmut status in regard to patient selection for cytoreductive surgery, especially in rOC

Characterisation of tumor microvessel density during progression of high-grade serous ovarian cancer: clinico-pathological impact. An OCTIPS Consortium study.

Background: High-grade serous ovarian cancer (HGSOC) intratumoural vasculature evolution remains unknown. The study investigated changes in tumour microvessel density (MVD) in a large cohort of paired primary and recurrent HGSOC tissue samples and its impact on patients’ clinico-pathological outcome. Methods: A total of 222 primary (pOC) and recurrent (rOC) intra-patient paired HGSOC were assessed for immunohistochemical expression of angiogenesis-associated biomarkers (CD31, to evaluate MVD, and VEGF-A). Expression profiles were compared between pOCs and rOCs and correlated with patients' data. Results: High intratumoural MVD and VEGF-A expression were observed in 75.7% (84/111) and 20.7% (23/111) pOCs, respectively. MVDhighand VEGF(+)samples were detected in 51.4% (57/111) and 20.7% (23/111) rOCs, respectively. MVDhigh/VEGF(+)co-expression was found in 19.8% (22/111) and 8.1% (9/111) of pOCs and rOCs, respectively (p = 0.02). Pairwise analysis showed no significant change in MVD (p = 0.935) and VEGF-A (p = 0.121) levels from pOCs to rOCs. MVDhighpOCs were associated with higher CD3(+)(p = 0.029) and CD8(+)(p = 0.013) intratumoural effector TILs, while VEGF(+)samples were most frequently encountered among BRCA-mutated tumours (p = 0.019). Multivariate analysis showed VEGF and MVD were not independent prognostic factors for OS. Conclusions: HGSOC intratumoural vasculature did not undergo significant changes during disease progression. High concentration of CD31(+)vessels seems to promote recruitment of effector TILs. The study also provides preliminary evidence of the correlation between VEGF-positivity and BRCA status