Ovarian Ascites Research Articles

Exosomal AHSG in ovarian cancer ascites inhibits malignant progression of ovarian cancer by p53/FAK/Src signaling.

The primary cause of mortality in patients with ovarian cancer (OC) is tumor metastasis. A comprehensive understanding of the mechanisms underlying metastasis in OC is essential for accurate prognosis prediction and the development of targeted therapeutic agents. Our findings indicate that alpha-2 Heremans Schmid glycoprotein (AHSG) is downregulated in OC exosomes. Consequently, the objective of this study was to identify novel prognostic markers and potential therapeutic targets for OC. Exosomes derived from OC cells and patient ascites were purified and applied to OC cells to assess their migratory ability using wound-healing and transwell assays. AHSG expression was enhanced by overexpressing lentivirus, and the resulting exosomes were isolated and co-cultured with OC cells to verify their effect on the migration ability of OC. Exosomes in ovarian malignant ascites have been demonstrated to promote OC metastasis. However, our findings indicate that AHSG is down-regulated in OC tissues and ascites exosomes. Furthermore, overexpression of AHSG in OC cells has been shown to markedly decrease their migratory ability, as well as reduce the migratory ability of cancer cells after co-culture of its exosomes with cancer cells. The low expression of AHSG in exosomes derived from OC tissues and ascites is associated with metastatic progression in OC patients. Additionally, cancer-derived AHSG can be transported to OC cells via exosomes, where it inhibits OC migration in vitro and in vivo by regulating the p53/FAK/Src signaling pathway. The present study demonstrated that AHSG, derived from cancer cells, exerts a negative regulatory effect on OC cell motility, migration, and metastasis. These findings suggest that AHSG is a potential candidate for OC treatment.

Characterization of latently infected EBV+ antibody-secreting B cells isolated from ovarian tumors and malignant ascites.

Intra-tumoral B cells mediate a plethora of immune effector mechanisms with key roles in anti-tumor immunity and serve as positive prognostic indicators in a variety of solid tumor types, including epithelial ovarian cancer (EOC). Several aspects of intra-tumoral B cells remain unclear, such as their state of activation, antigenic repertoires, and capacity to mature into plasma cells. B lymphocytes were isolated from primary EOC tissue and malignant ascites and were maintained in cell culture medium. The stably maintained cell lines were profiled with flow cytometry and B cell receptor sequencing. Secreted antibodies were tested with a human proteome array comprising more than 21,000 proteins, followed by ELISA for validation. Originating tumor samples were used for spatial profiling with chip cytometry. Antibody-secreting B lymphocytes were isolated from the ovarian tumor microenvironment (TME) of four different EOC patients. The highly clonal cell populations underwent spontaneous immortalization in vitro, were stably maintained in an antibody-secreting state, and showed presence of Epstein-Barr viral (EBV) proteins. All originating tumors had high frequency of tumor-infiltrating B cells, present as lymphoid aggregates, or tertiary lymphoid structures. The antigens recognized by three of the four cell lines are coil-coil domain containing protein 155 (CCDC155), growth factor receptor-bound protein 2 (GRB2), and pyruvate dehydrogenase phosphatase2 (PDP2), respectively. Anti-CCDC155 circulating IgG antibodies were detected in 9 of 20 (45%) of EOC patients' sera. Tissue analyses with multiparameter chip cytometry shows that the antibodies secreted by these novel human B cell lines engage their cognate antigens on tumor cells. These studies demonstrate that within the tumor-infiltrating lymphocyte population in EOC resides a low frequency population of antibody-secreting B cells that have been naturally exposed to EBV. Once stably maintained, these novel cell lines offer unique opportunities for future studies on intratumor B cell biology and new target antigen recognition, and for studies on EBV latency and/or viral reactivation in the TME of non-EBV related solid tumors such as the EOC.

ATR, CHK1 and WEE1 inhibitors cause homologous recombination repair deficiency to induce synthetic lethality with PARP inhibitors

PurposePARP inhibitors (PARPi) are effective in homologous recombination repair (HRR) defective (HRD) cancers. To (re)sensitise HRR proficient (HRP) tumours to PARPi combinations with other drugs are being explored. Our aim was to determine the mechanism underpinning the sensitisation to PARPi by inhibitors of cell cycle checkpoint kinases ATR, CHK1 and WEE1.Experimental designA panel of HRD and HRP cells (including matched BRCA1 or 2 mutant and corrected pairs) and ovarian cancer ascites cells were used. Rucaparib (PARPi) induced replication stress (RS) and HRR (immunofluorescence microscopy for γH2AX and RAD51 foci, respectively), cell cycle changes (flow cytometry), activation of ATR, CHK1 and WEE1 (Western Blot for pCHK1S345, pCHK1S296 and pCDK1Y15, respectively) and cytotoxicity (colony formation assay) was determined, followed by investigations of the impact on all of these parameters by inhibitors of ATR (VE-821, 1 µM), CHK1 (PF-477736, 50 nM) and WEE1 (MK-1775, 100 nM).ResultsRucaparib induced RS (3 to10-fold), S-phase accumulation (2-fold) and ATR, CHK1 and WEE1 activation (up to 3-fold), and VE-821, PF-477736 and MK-1775 inhibited their targets and abrogated these rucaparib-induced cell cycle changes in HRP and HRD cells. Rucaparib activated HRR in HRP cells only and was (60-1,000x) more cytotoxic to HRD cells. VE-821, PF-477736 and MK-1775 blocked HRR and sensitised HRP but not HRD cells and primary ovarian ascites to rucaparib.ConclusionsOur data indicate that, rather than acting via abrogation of cell cycle checkpoints, ATR, CHK1 and WEE1 inhibitors cause an HRD phenotype and hence “induced synthetic lethality” with PARPi.

Overcoming effector T cell exhaustion in ovarian cancer ascites with a novel adenovirus encoding for a MUC1 bispecific antibody engager and IL-2 cytokine

T cell-focused cancer immunotherapy including checkpoint inhibitors and cell therapies has been rapidly evolving over the past decade. Nevertheless, there remains a major unmet medical need in oncology generally and immuno-oncology specifically. We have constructed an oncolytic adenovirus, Ad5/3-E2F-d24-aMUC1aCD3-IL-2 (TILT-322), which is armed with a human aMUC1aCD3 T cell engager and IL-2. TILT-322 treatment stimulated T cell cytotoxicity through the increased presence of granzyme-B, perforin, and interferon-gamma. Additional immune profiling indicated TILT-322 increased gamma delta T cell activation and impacted other cell types such as natural killer cells, and natural killer-like T cells that are traditionally involved in cancer immunotherapy. TILT-322 treatment also decreased the proportion of exhausted CD8+ T cells as demarked by immune checkpoint expression in ovarian ascites samples. Overall, our data showed that TILT-322 treatment led to an enhanced T cell activation and reversed T cell exhaustion translating into high antitumor efficacy when given locally or intravenously. The analysis of blood and tumors isolated from an in vivo patient-derived ovarian cancer xenograft model suggested TILT-322 mediated tumor control through improved T cell functions. Therefore, TILT-322 is a promising novel anti-tumor agent for clinical translation.

Tumor alkalization therapy: misconception or good therapeutics perspective? - the case of malignant ascites.

Tumor acidity has been identified as a key factor in promoting cancer progression, metastasis, and resistance. Tumor alkalization therapy has emerged as a potential strategy for cancer treatment. This article provides preclinical and clinical evidence for tumor alkalization therapy as a promising cancer treatment strategy. The potential of tumor alkalization therapy using sodium bicarbonate in the treatment of malignant ascites was studied. The concept of intraperitoneal perfusion with an alkalizing solution to increase the extracellular pH and its antitumor effect were explored. The significant extension in the overall survival of the Ehrlich ascites carcinoma mice treated with sodium bicarbonate solution compared to those treated with a sodium chloride solution was observed. In the sodium bicarbonate group, mice had a median survival of 30 days after tumor cell injection, which was significantly (p<0.05) different from the median survival of 18 days in the sodium chloride group and 14 days in the intact group. We also performed a case study of a patient with ovarian cancer malignant ascites resistant to previous lines of chemotherapy who underwent intraperitoneal perfusions with a sodium bicarbonate solution, resulting in a significant drop of CA-125 levels from 5600 U/mL to 2200 U/mL in and disappearance of ascites, indicating the potential effectiveness of the treatment. The preclinical and clinical results obtained using sodium bicarbonate perfusion in the treatment of malignant ascites represent a small yet significant contribution to the evolving field of tumor alkalization as a cancer therapy. They unequivocally affirm the good prospects of this concept.

The IGF-PAPP-A-Stanniocalcin Axis in Serum and Ascites Associates with Prognosis in Patients with Ovarian Cancer.

Pregnancy-associated plasma protein-A (PAPP-A) and PAPP-A2 modulate insulin-like growth factor (IGF) action and are inhibited by the stanniocalcins (STC1 and STC2). We previously demonstrated increased PAPP-A and IGF activity in ascites from women with ovarian carcinomas. In this prospective, longitudinal study of 107 women with ovarian cancer and ascites accumulation, we determined corresponding serum and ascites levels of IGF-1, IGF-2, PAPP-A, PAPP-A2, STC1, and STC2 and assessed their relationship with mortality. As compared to serum, we found highly increased ascites levels of PAPP-A (51-fold) and PAPP-A2 (4-fold). Elevated levels were also observed for IGF-1 (12%), STC1 (90%) and STC2 (68%). In contrast, IGF-2 was reduced by 29% in ascites. Patients were followed for a median of 38.4 months (range: 45 days to 8.9 years), during which 73 patients (68.2%) died. Overall survival was longer for patients with high serum IGF-1 (hazard ratio (HR) per doubling in protein concentration: 0.60, 95% CI: 0.40-0.90). However, patients with high ascites levels of IGF-1 showed a poorer prognosis (HR: 2.00 (1.26-3.27)). High serum and ascites IGF-2 levels were associated with increased risk of mortality (HR: 2.01 (1.22-3.30) and HR: 1.78 (1.24-2.54), respectively). Similarly, serum PAPP-A2 was associated with mortality (HR: 1.26 (1.08-1.48)). Our findings demonstrate the presence and activity of the IGF system in the local tumor ecosystem, which is likely a characteristic feature of malignant disease and plays a role in its peritoneal dissemination. The potential clinical implications are supported by our finding that serum levels of the proteins are associated with patient prognosis.

18F-FDG PET/CT features of Meigs syndrome induced by ovarian sex cord stromal tumors: a retrospective clinical study

The objective of this study was retrospectively to analyze the clinical characteristics and 18F-FDG PET/CT findings in Meigs syndrome (MS) patients. A total of 21 patients with MS induced by ovarian stromal tumors and 69 patients with pseudo-MS caused by ovarian cancer (OC-PMS) were subjected to evaluation using 18F-FDG PET/CT. Visual and semi-quantitative methods were employed to analyze the PET/CT findings. Visual analysis included recording whether the density of the primary tumor was uniform, whether there were cystic changes and calcifications, and the location of serous fluid accumulation. Semi-quantitative analysis involved the measurement of the tumor size, SUVmax, and SUVmean. No significant difference was observed in the size and density of primary tumors between the MS group and the OC-PMS group. However, the SUVmax and SUVmean of tumors in the MS group were found to be significantly lower than those in the OC-PMS group. The amount of serous cavity effusion caused by ovarian sex cord stromal tumors was found to be unrelated to the size of the tumor, SUVmax, and SUVmean but was positively correlated with the level of Ca125. MS patients have both benign ovarian tumors and ascites and/or pleural effusion, which may be accompanied by elevated Ca125 levels. This should be considered as one of the differential diagnoses for ovarian cancer. Understanding the PET/CT features of MS can facilitate the attainment of an accurate diagnosis before surgery.

Meigs Syndrome: A Comprehensive Review of Clinical Presentation, Diagnosis, and Management

Meigs Syndrome is a rare clinical entity characterized by the triad of benign ovarian tumor, ascites, and pleural effusion. This syndrome, often masquerading as malignant disease, presents a diagnostic challenge for healthcare professionals. In this comprehensive review, we aim to provide a detailed analysis of the clinical manifestations, diagnostic modalities, and management strategies of Meigs Syndrome. We explore the epidemiology of the syndrome, emphasizing its rarity, and discuss the various etiological theories that underlie its pathophysiology. Differential diagnoses, including malignant conditions that mimic Meigs Syndrome, are examined to guide accurate and timely diagnosis. An in-depth analysis of imaging techniques, such as ultrasound, computed tomography, and magnetic resonance imaging, is included, along with the significance of tumor markers and cytology in diagnosis. The cornerstone of treatment primarily involves surgical intervention, and we delve into the various surgical approaches and outcomes. Additionally, we shed light on the postoperative course and long-term prognosis of patients with Meigs Syndrome. This review aims to equip clinicians, radiologists, and surgeons with a comprehensive understanding of this uncommon condition to facilitate prompt recognition and effective management.

When Thyroid Meets Ovary: A Case Report of Struma Ovarii

Struma Ovarii is not a common tumor. It is a mature ovarian teratoma, completely or predominantly composed of thyroid tissue. It belongs to a specialised monodermal variety. Struma ovarii may have an association with hyperthyroidism; however, it is a rare association and just in about 8% of cases. Its diagnosis is mostly delayed because most of the patients do not present any symptoms. Some patients may develop symptoms of specific conditions like ovarian torsion, hyperthyroidism, and ascites. Ultrasound, MRI, CT scan, and scintigraphic evaluation are necessary to differentiate benign from malignant variety. The first line treatment option is surgical removal. There are lesser chances that the tumor will recur and the quality of life is improved significantly. In this case report, we have discussed a unique case of struma ovarii. It was duly diagnosed and appropriate management was done. The tumor was different from malignant ovarian tumor on the basis of ascites and tumor marker assessments. Thyroid function investigations were also normal. The tumor is incidentally found on imaging in most cases. The definitive diagnosis is established by a histopathological study. The first line of treatment is surgical removal and it usually leads to a successful prognosis. We will determine the challenges that are faced to reach the diagnosis and management of this rare tumor. Misdiagnosis is common. The treatment options are debatable because it is a rare tumor. In fertile and young age groups, fertility conserving surgeries like ovarian cystectomy or unilateral salpingo-oophorectomy are advised. For the purpose of treatment, in postmenopausal cases, total abdominal hysterectomy with bilateral salpingo-oophorectomy may sometimes be indicated. The quality of life will improve if investigations are done early and appropriate management is done.

Krukenberg tumour in a patient with secondary infertility – case report

A patient with secondary infertility, diagnosed with an endometrial polyp and right ovarian cyst, was referred for hysterolaparoscopy treatment. The woman reported no symptoms. During the hospitalisation, in addition to the aforementioned issues, left ovarian lesions and ascites were identified. A 10 cm lesion in the right ovary exhibited abundant vascularity. Tumour markers (AFP, CEA, HE4, CA-125) and the ROMA algorithm were assessed and found to be within the normal range. Laparotomy revealed a high-grade malignant tumour of unknown origin confirmed by histological examination. Uterine resection with unchanged greater omentum was performed. Immunohistochemical tests revealed positive cytokeratin (CK) reaction, including CK7 and focal CK20, as well as a marker of proliferation Ki-67 in some cells (20–30%). Signet ring cells and positive mucicarmine stain reaction were detected. The histological evaluation confirmed a Krukenberg tumour originating most likely from the stomach. The patient was referred to the Maria Skłodowska-Curie Greater Poland Cancer for further treatment.

Ovarian cancer, malignant ascites and microenvironment. Literature review

Ovarian cancer (OC) is a heterogenous disease in terms of genetic mutations and tumor phenotypes and can be divided into I and II types. Type II high grade tumors are more common, accompanied by ascites, and are the main cause of cancer-related death in women. OC associated ascites is considered as valuable source of tumor material containing a wide range of dissolved components and cell populations. Over the past decades, the cellular and acellular components of ascites have been studied, but its effect on chemoresistance and the development of metastasis continues to be studied. This review describes the pathogenesis of ascites in OC, it’s cellular and acellular components, many of which are prognostic factors as well as markers of the effectiveness of anticancer therapy. Further study of the ascitic fluid composition in OC will help to identify not only prognostic factors, but also the points of application of targeted drugs and will improve the results of OC treatment.

Pregnancy Outcomes of Assisted Reproductive Technology (ART) Cycle Complicated by Ovarian Hyperstimulation Syndrome (OHSS): Case Series Study.

Ovarian hyperstimulation syndrome (OHSS) is a frequent, potentially lethal side effect of assisted reproductive technology (ART), distinguished by symptoms such as ovarian enlargement, ascites, and pleural effusion. This study is designed to study the effect of assisted reproductive technology (ART) cycle complicated by OHSS on pregnancy outcomes. A case series study at King Abdulaziz Medical City (KAMC) in Riyadh, Saudi Arabia, was executed to examine the pregnancy outcomes in in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) cycles. Fifteen patients were admitted to the IVF unit between January 2015 and December 2021. Data were retrieved from patients' medical records, and descriptive statistical methods were employed to analyze participants' data. The study assessed pregnancy outcomes for 15 female participants (mean age=31.1 years, SD=3.46) with a BMI range of 20-40 (mean BMI=29.6, SD=6.4), of whom 33.3% were classified as obese. The primary factor of infertility was anovulation (66.7%), followed by male factors (20%). About 26.7% of those affected by OHSS had moderate OHSS, and 73.3% had severe OHSS, with 100% of those with severe OHSS having undergone three embryo transfers. None of the participants developed gestational diabetes mellitus (DM), but one participant had high blood sugar levels (6.67% of total participants), with a mean glucose of 6.3±2.0. There were no instances of preeclampsia, gestational hypertension, abnormal placentas, or congenital abnormalities in newborns among the participants. Preterm deliveries were common, with 33.3% delivering between 32 and 37 weeks, 6.7% before 28 weeks, and 33.3% within 28-32 weeks. Overall, 73.3% of the participants experienced pregnancy, and the birth mode was almost evenly split between vaginal and cesarean birth. In conclusion, this research provides an exploration into the outcomes of pregnancies in women undergoing assisted reproductive technology treatments complicated by ovarian hyperstimulation syndrome. It shows anovulation as a prevalent cause of infertility and a noteworthy incidence of severe OHSS. Despite these challenges, a significant number of women were able to experience pregnancy, although preterm deliveries and abortions were common. The delivery methods were fairly balanced between vaginal birth and cesarean section. These findings underscore the necessity for more effective strategies to manage OHSS and improve pregnancy outcomes in ART procedures.

Therapeutic effect of a VSIG4-specific mAb EU103 in a preclinical model of patient-derived ascites of ovarian cancer.

e14516 Background: V-set and immunoglobulin domain-containing 4 (VSIG4) is one of the B7 family-related proteins that includes PD-L1, VISTA, and CTLA4 ligand. VSIG4 overexpression is correlated with poor prognosis in patients with ovarian cancer, lung cancer, gastric cancer, high-grade glioma, and multiple myeloma. VSIG4 is also known to function as a receptor for complements and the negative regulation of T cell proliferation. Although VSIG4 is highly expressed in tissue-resident macrophages and tumor-associated macrophages (TAM), its role in the tumor microenvironment (TME) is not fully elucidated. Methods: We previously developed a therapeutic antibody, EU103, in a humanized form of a VSIG4-specific antibody. Most importantly, we demonstrated that EU103 directly acts on the tumor-associated macrophages (TAM) and mechanistically induces repolarization of TAM to tumor killing M1 macrophages and blocks VSIG4-mediated T cell suppression, eventually leading to CD8+ T cell proliferation and tumor suppression in a PBMC-humanized human lung cancer mouse model. Results: Expanding our previous findings with the therapeutic potential of EU103 in a non-small cell lung carcinoma (NSCLC), here, we also proved its therapeutic effect in human ovarian cancer. Firstly, TAMs isolated from ovarian cancer patients express high levels of VSIG4 with immunosuppressive M2 macrophage phenotype. Secondly, EU103 treatment of the TAMs in in vitro studies induces M2-to-M1 conversion and activation of T cells in the ascites leading to ovarian tumor cell killing in a dose-dependent manner. Thirdly, in vivo therapeutic efficacy of EU103 in ovarian cancer, especially through M2-to-M1 conversion, is also verified in both CD34+ cell and peripheral blood mononuclear cell (PBMC) humanized mouse models. Finally, we validate the results above by treating ovarian cancer patient-derived ascites with EU103. Conclusions: Almost 300,000 women are diagnosed with ovarian cancer worldwide each year, and ovarian cancer ranks fifth in cancer deaths among women. In the United States alone, we expect approximately 20,000 new diagnoses and more than 12,000 deaths for this year. Given our findings in this study and clinical significance, we propose here the therapeutic potential of EU103, previously developed by our proprietary antibody discovery and engineering technology, in ovarian cancer.

Abstract 5153: The role of CCL22-specific CD4 T cells in modulating the immunosuppressive tumor microenvironment in ovarian cancer

Abstract Background: CCL22, a macrophage-derived chemokine, is overexpressed in ovarian cancer and exerts immunosuppressive functions by the recruitment of regulatory T cells (Tregs) to the tumor microenvironment (TME). Our research group described naturally occurring T cells specific for an MHC class I epitope derived from CCL22. CD8+ CCL22-specific T cells isolated from cancer patients could recognize CCL22-expressing cells and decrease the levels of CCL22 in ovarian ascites in vitro. Expansion of CCL22-specific CD8+ T cells in animal models of cancer by peptide vaccination led to a therapeutic anti-tumor effect by reducing Treg recruitment into the TME. In this study we aimed at characterizing CD4+ CCL22-specific T cells and their potential for modulating the tumor microenvironment in ovarian cancer. Methods: CCL22-responses were screened with a library of overlapping 20mer peptides covering the entire sequence of CCL22 in PBMCs from healthy donors and ovarian cancer patients. CCL22-specific T cells were isolated from PBMCs and ovarian ascites for functional characterization through IFNγ ELISpot and ICS against peptides and CCL22-expressing target cells. Cytokine secretion was measured with protein multiplex immunoassays. Vaccination and therapeutic efficacy were evaluated in BALB/c CT26 and 4T1 syngeneic models. Results: We identified an immunogenic region in the CCL22 protein sequence and detected CD4 T-cell responses against CCL22-derived peptides in healthy donors and ovarian cancer patients through IFNγ ELISpot. CCL22-specific CD4+ cells have also been identified ex vivo in the ascites fluid from patients with ovarian cancer. We isolated and expanded CCL22-specific CD4+ T-cell clones from the ovarian ascites and demonstrated their reactivity against CCL22-producing cell lines. Furthermore, the stimulation of CCL22-specific CD4+ T cells in the PBMC culture and ascites samples was associated with a modulation of the cytokine environments. Additionally, vaccination with surrogate murine 20mer and MHC-II restricted CCL22-derived peptides lead to successful induction of specific T-cell responses in the spleens and draining lymph nodes of vaccinated animals. Activation of such CCL22-specific CD4 T cell responses was associated with a therapeutic effect seen as reduction of the tumor growth in different models of cancer. Conclusion: This study provides evidence for the ability of pro-inflammatory CD4+ CCL22-specific T cells to modulate the tumor microenvironment, particularly in ovarian cancer. Altogether we provide the rationale for the development of a CCL22-based immune modulatory vaccination for ovarian cancer. Citation Format: Ines Lecoq, Evelina Martinenaite, Marie C. Westergaard, Inge Marie Svane, Mads H. Andersen. The role of CCL22-specific CD4 T cells in modulating the immunosuppressive tumor microenvironment in ovarian cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5153.

Abstract 1994: Sustained delivery of PARP inhibitor Talazoparib for the treatment of BRCA deficient ovarian cancer

Abstract Ovarian cancer has long been known to be the deadliest cancer associated with the female reproductive system. More than 15% of ovarian cancer patients have a defective BRCA-mediated homologous recombination repair pathway that can be therapeutically targeted with PARP inhibitors, such as Talazoparib (TLZ). The expansion of TLZ clinical approval beyond breast cancer has been hindered due to the highly potent systemic side effects resembling chemotherapeutics. Here we report the development of a novel TLZ-loaded PLGA implant (InCeT-TLZ) that sustainedly releases TLZ over 25 days directly into the peritoneal cavity (i.p.) to treat BRCA-mutated metastatic ovarian cancer (mOC). Methods: InCeT-TLZ was fabricated by dissolving TLZ and PLGA in chloroform followed by extrusion and evaporation. Drug loading and release were confirmed by HPLC. The detailed structure of InCeT-TLZ was checked by scanning electron microscopy. The in vivo therapeutic efficacy of InCeT-TLZ was carried out in a murine Brca2-/-p53R172H/-Pten-/- genetically engineered peritoneally metastatic ovarian cancer model. Treatment started 7 days post tumor inoculation. All mice were monitored by IVIS imaging once a week to confirm and track tumor growth. On day 8, mice with tumors (4-5 mm in diameter) were divided into 4 groups: PBS i.p. injection (50 μl, three times a week), empty implant i.p. implantation (2.5 mm, every 25 days), TLZ i.p. injection (0.33 mg/kg of TLZ by i.p. injection three times a week), and InCeT-TLZ i.p. implantation (2.5 mm, equal to a total amount of 10 i.p. injection doses, every 25 days). Body weight was recorded three times a week as an indicator of treatment tolerance and efficacy. Mice were sacrificed when the body weight increased by 50% of the initial weight. Results and Conclusion: The drug-loaded PLGA implant was developed for the sustained and local delivery of TLZ to treat high-grade serous ovarian cancer with a loading efficiency of 26.75 μg/mm. Implants can be easily placed into the peritoneal cavity of patients or animals with an 18-gauge clinical needle. The extended survival in InCeT-TLZ treated mice compared to the TLZ injection group indicated that the slow release of TLZ maximizes PARP inhibitor therapy in the peritoneal cavity for disseminated cancer treatment. Decrease in ascites formation within the intraperitoneal cavity of the InCeT-TLZ group suggests a promising treatment for ovarian cancer-associated ascites and disease progression. Histopathology following peritoneal InCeT-TLZ implantation showed no toxicity in any surrounding organs at risk. This approach would offer new sustained therapy options for substantially enhancing the therapeutic window, increasing cure rates, reducing mortality and suffering, and offering major enhancements in quality of life for the thousands of women diagnosed with OC yearly. Citation Format: Shicheng Yang, Needa Brown, Abigail L. Campbell, Kushi Aggarwal, Daniela M. Dinulescu, Srinivas Sridhar. Sustained delivery of PARP inhibitor Talazoparib for the treatment of BRCA deficient ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1994.

Abstract 2936: INCA33890, a novel PD-1×TGFꞵR2 bispecific antibody conditionally antagonizes TGFꞵ signaling in primary immune cells co-expressing PD-1

Abstract Transforming growth factor-β (TGFβ) signaling is common in many solid tumors and is initiated by binding of the high affinity canonical ligands TGFβ1, 2, οr 3 to TGFβR2, which forms a heteromeric receptor complex with TGFβR1 (Derynck et al, Nature Review Clinical Oncology 2020). Activation of the pathway results in potent suppression of immune cell-mediated anti-tumor immunity and has been reported to predict poor response to PD-(L)1 targeted therapy in patients (Mariathasan et al, Nature 2018; Kieffer et al, Cancer Discovery 2020). However, TGFβ drug development has been hampered by the occurrence of adverse events. INCA33890 is a dual PD-1 and TGFβR2 binding bispecific Biclonics® antibody, developed to antagonize the TGFβ signaling pathway specifically in cells co-expressing PD-1 and TGFBR2. Additionally, it potently antagonizes the PD-1 axis independently of TGFβR2 co-expression. The cell-selective action of INCA33890 was designed to mitigate risks of the known adverse effects associated with TGFβ-pathway inhibition in tissues requiring active TGFβ signaling. ΙΝCΑ33890 mediates its specificity through a PD-1 binding arm with a &amp;gt;10-fold higher affinity relative to the TGFβR2 binding arm. Consistent with this profile, in isogenic Jurkat cells expressing TGFβR2 ± PD-1, INCA33890 potently inhibits TGFβ1-induced pSMAD activation in a PD-1-correlated manner. Additionally, in two independent PD-1 reporter assays, INCA33890 inhibited SHP recruitment and enhanced NFAT activation with a potency within an order of magnitude to that of pembrolizumab. In mixed lymphocyte reaction assays with exhausted primary human T-cells, INCA33890 was found to induce a similar level of anti-tumor cytokine production as the combination of pembrolizumab and an anti-TGFβR2 antagonist mAb. Treatment of primary ovarian ascites with INCA33890 ex vivo induced IFNγ production in all donors tested, while pembrolizumab had no activity. Similarly, in human CD34+ cell-engrafted NSG mice, INCA33890 significantly inhibited the growth of human MDA-MB-231 and A375 subcutaneous xenograft tumors, whereas pembrolizumab or an anti-TGFβR2 antibody had little or no monotherapy activity. INCA33890 had a balanced pharmacokinetic and potency profile and was well tolerated in NHPs at exposures required for pharmacodynamic and tumor growth inhibiting activity in rodents. Encouragingly, there was no evidence of adverse effects in NHPs due to TGFβ-pathway blockade. Collectively, these results provide compelling data for an effective and specific approach to simultaneously antagonizing TGFβ and PD-1 signaling in tumors. Clinical development of INCA33890 in checkpoint inhibitor-resistant and other cancers has been initiated. Citation Format: Liang-Chuan S. Wang, Rinse Klooster, Ashwini Kulkarni, Amaya Garcia de Vinuesa, Maxim Soloviev, Linda JA Hendriks, Lu Huo, Michael Weber, Arpita Mondal, Yonghong Zhao, Shane Harvey, Xin He, Hong Chang, April Horsey, Alla Volgina, Yue Zhang, Veethika Pandey, Yan-Ou Yang, Jonathan Rios-Doria, Evgeniy Eruslanov, Daniel J. Powell, Steven M. Albelda, John de Kruif, Horacio Nastri, Cecile Geuijen, Patrick A. Mayes. INCA33890, a novel PD-1×TGFꞵR2 bispecific antibody conditionally antagonizes TGFꞵ signaling in primary immune cells co-expressing PD-1 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2936.

Generation and Culturing of High-Grade Serous Ovarian Cancer Patient-Derived Organoids.

Organoids are 3D dynamic tumor models that can be grown successfully from patient-derived ovarian tumor tissue, ascites, or pleural fluid and aid in the discovery of novel therapeutics and predictive biomarkers for ovarian cancer. These models recapitulate clonal heterogeneity, the tumor microenvironment, and cell-cell and cell-matrix interactions. Additionally, they have been shown to match the primary tumor morphologically, cytologically, immunohistochemically, and genetically. Thus, organoids facilitate research on tumor cells and the tumor microenvironment and are superior to cell lines. The present protocol describes distinct methods to generate patient-derived ovarian cancer organoids from patient tumors, ascites, and pleural fluid samples with a higher than 97% success rate. The patient samples are separated into cellular suspensions by both mechanical and enzymatic digestion. The cells are then plated utilizing a basement membrane extract (BME) and are supported with optimized growth media containing supplements specific to the culturing of high-grade serous ovarian cancer (HGSOC). After forming initial organoids, the PDOs can sustain long-term culture, including passaging for expansion for subsequent experiments.

Meigs Syndrome: A Case Report and Literature Review

Introduction: Meigs syndrome is defined by the presence of an ovarian benign tumor, ascites, and pleural effusion. The restoration of normal conditions following the removal of the ovarian mass is typical. Although an increase in CA 125 has been reported in association with Meigs syndrome, a level above 1000 IU/mL is unusual, and there is no clear association between patients’ or tumor/cancer characteristics and CA 125 increment to the best of our knowledge. Materials and methods: We conducted a review of Meigs syndrome cases associated with high CA 125 levels and then divided and compared all cases found in the literature and the one described in the text, taking into account the increase of CA 125 = 1000 IU/mL, to identify any possible factor influencing the CA 125 increase. Results: A 55-year-old woman with Meigs syndrome (hydrothorax, ovarian fibroma, and ascites) presented CA 125 of 1713 IU/mL. In our review, we found 43 articles that collected 55 cases of Meigs syndrome with an increase in CA 125 of 25% or more than 1000 IU/mL. Considering two groups, divided considering the CA 125 value of 1000 IU/mL, we found that the presence of bilateral masses and ascites over 2 L represented independent risk factors for high elevation of CA 125. Conclusion: The presence of bilateral mass and an increase in ascites were associated with an increase in CA 125 of 1000 IU/mL, which could be useful in maintaining a benign lesion hypothesis even if the definitive diagnosis could not be made until after surgery, at histological evaluation.

Meigs syndrome: a case report and literature review

Introduction: Meigs syndrome is defined by the presence of an ovarian benign tumor, ascites, and pleural effusion. The restoration of normal conditions following the removal of the ovarian mass is typical. Although an increase in CA 125 has been reported in association with Meigs syndrome, a level above 1000 IU/mL is unusual, and there is no clear association between patients’ or tumor/cancer characteristics and CA 125 increment to the best of our knowledge. Materials and methods: We conducted a review of Meigs syndrome cases associated with high CA 125 levels and then divided and compared all cases found in the literature and the one described in the text, taking into account the increase of CA 125 = 1000 IU/mL, to identify any possible factor influencing the CA 125 increase. Results: A 55-year-old woman with Meigs syndrome (hydrothorax, ovarian fibroma, and ascites) presented CA 125of 1713 IU/mL. In our review, we found 43 articles that collected 55 cases of Meigs syndrome with an increase inCA 125 of 25% or more than 1000 IU/mL. Considering two groups, divided considering the CA 125 value of 1000IU/mL, we found that the presence of bilateral masses and ascites over 2 L represented independent risk factors for high elevation of CA 125. Conclusion: The presence of bilateral mass and an increase in ascites were associated with an increase in CA125 of 1000 IU/mL, which could be useful in maintaining a benign lesion hypothesis even if the definitive diagnosis could not be made until after surgery, at histological evaluation.

Friend and foe: the regulation network of ascites components in ovarian cancer progression.

The tumor microenvironment (TME) and its complex role in cancer progression have been hotspots of cancer research in recent years. Ascites, which occurs frequently in patients with ovarian cancer especially in advanced stages, represents a unique TME. Malignant ascites contains abundant cellular and acellular components that play important roles in tumorigenesis, growth, metastasis, and chemoresistance of ovarian cancer through complex molecular mechanisms and signaling pathways. As a valuable liquid biopsy sample, ascites fluid is also of great significance for the prognostic analysis of ovarian cancer. The components of ovarian cancer ascites are generally considered to comprise tumor-promoting factors; however, in recent years studies have found that ascites also contains tumor-suppressing factors, raising new perspectives on interactions between ascites and tumors. Malignant ascites directly constitutes the ovarian cancer microenvironment, therefore, the study of its components will aid in the development of new therapeutic strategies. This article reviews the current research on tumor-promoting and tumor-suppressing factors and molecular mechanisms of their actions in ovarian cancer-derived ascites and therapeutic strategies targeting ascites, which may provide references for the development of novel therapeutic targets for ovarian cancer in the future.