Oncolytic adenovirus in treating malignant ascites: A phase II trial and longitudinal single-cell study.

Malignant ascites is a common complication resulting from the peritoneal spread of malignancies, and currently lacks effective treatments. We conducted a phase II trial (NCT04771676) to investigate the efficacy and safety of oncolytic adenovirus H101 and virotherapy-induced immune response in 25 patients with malignant ascites. Oncolytic virotherapy achieved an increased median time to repeat paracentesis of 45 days (95% confidence interval 16.5-73.5 days), compared with the preset control value of 13 days. Therapy was well-tolerated, with pyrexia, fatigue, nausea, and abdominal pain as the most common toxicities. Longitudinal single-cell profiling identified marked oncolysis, early virus replication, and enhanced CD8+ T cells-macrophages immune checkpoint crosstalk, especially in responsive patients. H101 also triggered a proliferative burst of CXCR6+ and GZMK+CD8+ T cells with promoted tumor-specific cytotoxicity. Further establishment of oncolytic virus-induced T cell expansion signature (OiTE) implicated the potential benefits for H101-responsive patients from subsequent anti-PD(L)1 therapy. Patients with upregulated immune-signaling pathways in tumor cells and a higher proportion of CLEC10A+ dendritic cells and GZMK+CD8+ T cells at baseline showed a superior response to H101 treatment. Our study demonstrates promising clinical responses and tolerability of oncolytic adenovirus in treating malignant ascites and provides insights into the relevant cellular processes following oncolytic virotherapy.

PD-L1+ neutrophils induced NETs in malignant ascites is a potential biomarker in HCC.

BACKGROUND: Since differentiating malignant ascites from benign ascites has always been a clinical difficult, recognition of novel biomarkers in malignant ascites of hepatocellular carcinoma (HCC) patients could be helpful for establishing a diagnosis for HCC patients with ascitic fluids. METHODS: Thirty-five HCC patients with malignant ascites and chronic liver diseases patients with benign ascites were enrolled. Serum and ascites specimens were collected to determine TAN subpopulations and NETs concentration. Then, the correlation between ascitic NETs levels and clinical features were analyzed, and ROC curves were generated to evaluate the diagnostic value of NETs. For in vitro study, fresh neutrophils were employed to explore the underlying mechanism of TAN polarization and NETs formation using RNAseq analysis. RESULTS: Significantly increased pro-tumor PD-L1+ TANs and higher lactate levels were measured in HCC ascites. RNAseq data showed that lactate regulated genes expression involving PD-L1 expression and NETs formation, suggesting that ascitic lactate might be responsible for tumor progression in TME. Then, NETs-related markers including calprotectin, dsDNA, CitH3, MPO and MPO-DNA were found dramatically elevated in malignant ascites. Next, correlation analysis revealed that ascitic NETs levels positively correlated with LDH, a classic ascitic biochemical indicator. Furthermore, we identified the diagnostic values of NETs in discriminating malignant ascites from benign ascites. CONCLUSIONS: Our findings highlighted that elevated ascitic NETs served as a biomarker in HCC patients with malignant ascites, which provided useful insights for both clinical and basic research for malignant ascites diagnosis and management.

The complex role of IL-10 in malignant ascites: a review.

The emergence of malignant ascites (MA) indicates poor prognoses in patients with ovarian, gastrointestinal, breast, and pancreatic cancer. Interleukin-10 (IL-10) is a pleiotropic cytokine with immunoregulatory effects in tumor microenvironment. The level of IL-10 in MA varied across cancer types and patients, influencing cancer progression and outcomes. Originating from various immune and cancer cells, IL-10 contributes to complex signaling pathways in MA. Systemic IL-10 administration, although the evidence of its efficacy on MA is limited, still emerges as a promising therapeutic strategy because it can increase CD8+ T cells cytotoxicity and invigorate exhausted CD8+ tumor infiltration lymphocytes (TILs) directly. IL-10 signaling blockade also demonstrates great potential when combined with other immunotherapies in MA treatment. We reviewed the levels, origins, and functions of IL-10 in malignant ascites and overviewed the current IL-10 signaling targeting therapies, aiming to provide insights for MA treatment.

Treatment outcomes of gemcitabine plus nab-paclitaxel in pancreatic cancer patients with malignant ascites.

BACKGROUND: Gemcitabine plus nab-paclitaxel (GnP) therapy has been shown to improve the prognosis in patients with metastatic pancreatic cancer (PC); however, the efficacy and safety of GnP in PC patients with malignant ascites (MA) remains unknown. METHODS: We retrospectively investigated PC patients with peritoneal dissemination who had received GnP as first-line chemotherapy at our institution between March 2015 and August 2021. The following patient data were reviewed: patient characteristics, overall survival (OS), progression-free survival (PFS), objective response rate (ORR), adverse events (AEs), and relative dose intensity (RDI). The severity of MA was categorized based on the CT findings as grade 1 (small), grade 2 (moderate), or grade 3 (massive). RESULTS: A total of 189 patients were included; the study endpoints were compared between patients with each ascites grade and 41 patients without MA. The MA was classified as grade 1 in 85 patients, grade 2 in 41 patients, and grade 3 in 22 patients. In the patients with MA, the median OS, PFS and ORR were 11.2 months, 5.7 months and 24.3%, respectively. The OS and PFS decreased with increasing the severity of MA; in particular, patients with grade 2 and 3 showed a poorer prognosis. There were no differences in AEs, except for anorexia, or the RDI according to the severity of MA. CONCLUSION: GnP showed moderate efficacy with manageable safety profile in PC patients with MA. However, PC patients with moderate to massive ascites still have a dismal prognosis, and further development of effective treatments is needed.

Intensifying supportive care is associated with improved survival in gastric cancer patients with malignant ascites.

BACKGROUND: Gastric cancer patients with malignant ascites often have poor functional status and malnutrition that preclude receipt of systemic therapies. Thus, these patients have a very poor prognosis. Beginning in 2019, our multidisciplinary gastric cancer disease-oriented team implemented a more aggressive supportive care plan for gastric cancer patients with malignant ascites. The initiative included measures such as supplemental enteral nutrition, ascites drainage, and initiation of chemotherapy on an inpatient basis. We compared outcomes for gastric cancer patients who presented with synchronous malignant ascites treated before and after the implementation of the care plan. METHODS: We performed a retrospective review of our institutional database to identify patients diagnosed with gastric adenocarcinoma and synchronous malignant ascites between 2010 and 2022. We compared overall survival (OS) between patients diagnosed from 2010 to 2018, which will be referred to as the historical control era and patients diagnosed from 2019 to 2022, which will be called the aggressive supportive care era. RESULTS: Fifty-four patients were included in our analysis; 31 patients were treated in the historical control time frame, and 23 patients were treated during the aggressive supportive care era. Demographic, clinical, and pathologic characteristics were similar between groups. 3% of historical controls received supplemental tube feeds at diagnosis as compared to 30% of the aggressive supportive care cohort (p < 0.01). 3% of historical controls received their first cycle of chemotherapy in the inpatient setting versus 39% of patients treated during the aggressive supportive care era (p < 0.01). The median number of chemotherapy cycles received was 5 among historical controls and 9.5 among aggressive supportive care era patients (p = 0.02). There was no difference in the number of days spent as an inpatient between the two groups. The median OS for historical control patients was 5.4 months as compared with 10.4 months for patients treated during aggressive supportive care era (p = 0.04). CONCLUSIONS: Gastric cancer patients with synchronous malignant ascites treated during a timeframe when our multidisciplinary team implemented more aggressive supportive care measures had improved OS as compared with historic controls. Our results suggest that aggressive supportive measures for these patients with highly challenging clinical issues and poor prognosis can prolong survival. Specifically, initiation of chemotherapy in the inpatient setting and supplemental nutrition should be considered for patients at high risk for treatment intolerance.

Advances in the treatment of malignant ascites in China.

PURPOSE: Malignant ascites (MA) often occurs in recurrent abdominal malignant tumors, and the large amount of ascites associated with cancerous peritonitis not only leads to severe abdominal distension and breathing difficulties, but also reduces the patient's quality of life and ability to resist diseases, which usually makes it difficult to carry out anti-cancer treatment. The exploration of MA treatment methods is also a key link in MA treatment. This article is going to review the treatment of MA, to provide details for further research on the treatment of MA, and to provide some guidance for the clinical treatment of MA. METHOD: This review analyzes various expert papers and summarizes them to obtain the paper. RESULT: There are various treatment methods for MA, including systemic therapy and local therapy. Among them, systemic therapy includes diuretic therapy, chemotherapy, immunotherapy, targeted therapy, anti angiogenic therapy, CAR-T, and vaccine. Local therapy includes puncture surgery, peritoneal vein shunt surgery, acellular ascites infusion therapy, radioactive nuclide intraperitoneal injection therapy, tunnel catheter, and intraperitoneal hyperthermia chemotherapy. And traditional Chinese medicine treatment has also played a role in enhancing efficacy and reducing toxicity to a certain extent. CONCLUSION: Although there has been significant progress in the treatment of MA, it is still one of the clinical difficulties. Exploring the combination or method of drugs with the best therapeutic effect and the least adverse reactions to control MA is still an urgent problem to be solved.

Soluble factors in malignant ascites promote the metastatic adhesion of gastric adenocarcinoma cells.

BACKGROUND: Adenocarcinoma of the proximal stomach is the fastest rising malignancy in North America. It is commonly associated with peritoneal accumulation of malignant ascites (MA), a fluid containing cancer and inflammatory cells and soluble proteins. Peritoneal metastasis (PM) is the most common site of gastric cancer (GC) progression after curative-intent surgery and is the leading cause of death among GC patients. METHODS/RESULTS: Using a panel of gastric adenocarcinoma cell lines (human: MKN 45, SNU-5; murine: NCC-S1M), we demonstrate that prior incubation of GC cells with MA results in a significant (> 1.7-fold) increase in the number of cells capable of adhering to human peritoneal mesothelial cells (HPMC) (p < 0.05). We then corroborate these findings using an ex vivo PM model and show that MA also significantly enhances the ability of GC cells to adhere to strips of human peritoneum (p < 0.05). Using a multiplex ELISA, we identify MIF and VEGF as consistently elevated across MA samples from GC patients (p < 0.05). We demonstrate that agents that block the effects of MIF or VEGF abrogate the ability of MA to stimulate the adhesion of GC cells to adhere to human peritoneum and promote both ex vivo and in vivo metastases. CONCLUSION: Agents targeting MIF or VEGF may be relevant to the treatment or prevention of PM in GC patients.

Hyperthermic intrathoracic/intraperitoneal chemotherapy versus conventional intrapleural/intraperitoneal chemotherapy for the malignant effusion: a multi-center randomized clinical trial.

OBJECTIVE: To compare the efficacy and safety of hyperthermic intrathoracic/intraperitoneal chemotherapy versus conventional intrapleural/intraperitoneal chemotherapy in the treatment of malignant pleural or peritoneal effusion. METHODS: A randomized clinical trial was carried out in 8 cancer centers across China. Patients with malignant pleural or peritoneal effusion were randomly assigned to the study group or control group. Patients in the study group were treated with cisplatin-based hyperthermic intrathoracic chemotherapy (HITHOC) or hyperthermic intraperitoneal chemotherapy (HIPEC), while the control group was treated with conventional intrapleural or intraperitoneal chemotherapy using same chemotherapeutic regime as the study group. The objective response rate (ORR) was analyzed as primary outcome. Quality-of-life (QOL) score was recorded as secondary outcome using the questionnaire 30 (QLQ-C30) of the European Organization for Research and Treatment of Cancer (EORTC). The efficacy and safety of the two treatments were compared. RESULTS: Total 135 patients were recruited and randomized in this study, with 67 patients in the study group and 68 patients in the control group. The ORR in the study group (80.70%) was significantly higher than that in the control group (31.03%, p < 0.001). However, neither changes of QOL scores, nor incidence rates of adverse events were significantly different between the two groups (p = 0.076 and 0.197, respectively). CONCLUSION: Efficacy of HITHOC or HIPEC is superior to that of conventional modality for the treatment of malignant effusion with comparable side effects.

Anti-Tumor Immunogenicity of the Oncolytic Virus CF33-hNIS-antiPDL1 against Ex Vivo Peritoneal Cells from Gastric Cancer Patients.

We studied the immunotherapeutic potential of CF33-hNIS-antiPDL1 oncolytic virus (OV) against gastric cancer with peritoneal metastasis (GCPM). We collected fresh malignant ascites (MA) or peritoneal washings (PW) during routine paracenteses and diagnostic laparoscopies from GC patients (n = 27). Cells were analyzed for cancer cell markers and T cells, or treated with PBS, CF33-GFP, or CF33-hNIS-antiPDL1 (MOI = 3). We analyzed infectivity, replication, cytotoxicity, CD107α upregulation of CD8+ and CD4+ T cells, CD274 (PD-L1) blockade of cancer cells by virus-encoded anti-PD-L1 scFv, and the release of growth factors and cytokines. We observed higher CD45-/large-size cells and lower CD8+ T cell percentages in MA than PW. CD45-/large-size cells were morphologically malignant and expressed CD274 (PD-L1), CD252 (OX40L), and EGFR. CD4+ and CD8+ T cells did not express cell surface exhaustion markers. Virus infection and replication increased cancer cell death at 15 h and 48 h. CF33-hNIS-antiPDL1 treatment produced functional anti-PD-L1 scFv, which blocked surface PD-L1 binding of live cancer cells and increased CD8+CD107α+ and CD4+CD107α+ T cell percentages while decreasing EGF, PDGF, soluble anti-PD-L1, and IL-10. CF33-OVs infect, replicate in, express functional proteins, and kill ex vivo GCPM cells with immune-activating effects. CF33-hNIS-antiPDL1 displays real potential for intraperitoneal GCPM therapy.

Feasibility of a fast-track randomized controlled trial of cell-free and concentrated ascites reinfusion therapy for patients with refractory malignant ascites.

BACKGROUND: Malignant ascites often causes discomfort in advanced cancer patients. Paracentesis is the most common treatment modality, but it requires frequently repeated treatment. Cell-free and concentrated ascites reinfusion therapy (CART) may prolong the paracentesis interval, but controlled trials are lacking. We assessed the feasibility of a randomized controlled trial of CART vs. paracentesis alone for patients with refractory malignant ascites. METHODS: This study was an open-label, fast-track, randomized controlled, feasibility trial. Patients admitted to four designated cancer hospitals who received no further anticancer treatments were eligible. Patients were randomly assigned 1:1 to a CART arm or control (simple paracentesis) arm. The feasibility endpoint was the percentage of patients who completed the study intervention. Secondary endpoints included paracentesis-free survival, patient's request on the questionnaire for paracentesis (PRO-paracentesis)-free survival (the period until the patients first reported that they would want paracentesis if indicated), and adverse events. RESULTS: We screened 953 patients for eligibility. Of 61 patients with refractory malignant ascites, 21 patients were determined as eligible. Finally, 20 patients consented and were allocated; 18 patients (90%, 95% CI: 68.3-98.8) completed the study intervention. All patients had an ECOG performance status of 3 or 4. The median drained ascites volume was 3,200 mL in the CART arm and 2,500 mL in the control arm. In the CART arm, the median reinfused albumin volume was 12.6 g. Median paracentesis-free survivals were 5 days (95% CI: 2-6) in the CART arm, and 6 days (3-9) in the control arm. Median PRO-paracentesis-free survivals were 4 days (2-5) and 5 days (1-9), respectively. A total of 73% of patients received paracentesis within 2 days from their first request for the next paracentesis. One patient in the CART arm developed Grade 1 fever. CONCLUSIONS: A fast-track randomized controlled trial of CART for patients with malignant ascites is feasible. The efficacy and safety of CART should be assessed in future trials. PRO-paracentesis-free survival may be a complementary outcome measure with paracentesis-free survival in future trials. TRIAL REGISTRATION: Registered at University Hospital Medical Information Network Clinical Trial Registry as UMIN000031029 . Registered on 28/01/2018.

Adverse effects of cell-free and concentrated ascites reinfusion therapy for malignant ascites: a single-institute experience.

BACKGROUND: Cell-free and concentrated ascites reinfusion therapy (CART) is a strategy for improving various intractable symptoms due to refractory ascites, including hypoalbuminemia. CART has recently been applied in the treatment of cancer patients. This study was performed to assess the safety of CART in a single cancer institute. METHODS: We retrospectively reviewed 233 CART procedures that were performed for 132 cancer patients in our institute. RESULTS: The median weight of ascites before and after concentration was 4,720 g and 490 g (median concentration rate, 10.0-fold), The median amounts of total protein and albumin were 64.0 g and 32.6 g (median recovery rates, 44.9% and 49.0%), respectively. Thirty-three adverse events (AEs) were observed in 22 (9.4%) of 233 procedures; 30 of these events occurred after reinfusion. The most common reinfusion-related AEs were fever (13 events) and chills (10 events). Univariate analyses revealed no significant relationships between the frequency of AEs and age, sex, appearance of ascites, weight of harvested and concentrated ascites, the ascites processing rate (filtration and concentration), weight of saline used for membrane cleaning, amount of calculated total protein for infusion, or prophylaxis against AEs; the reinfusion rate of ≥ 125 mL/h or ≥ 10.9 g/h of total protein affected the frequency of AEs, regardless of the prophylactic use of steroids. CONCLUSIONS: The observed AEs were mainly mild reactions after reinfusion, which were related to a reinfusion rate of volume ≥ 125 mL/h, a simple indicator in practice, or total protein ≥ 10.9 g/h. Although our study was retrospective in nature and undertaken in a single institute, this information may be helpful for the management of cancer patients with refractory malignant ascites using CART.

Cost-effectiveness of tunneled peritoneal catheters versus repeat paracenteses for recurrent ascites in gynecologic malignancies.

OBJECTIVE: To compare the cost-effectiveness of tunneled peritoneal catheter (TPC) versus repeated large-volume paracentesis (LVP) for patients with recurrent ascites secondary to gynecological malignancy. METHODS: A retrospective cohort study was performed at a single institution from 2016 through 2019 of patients with recurrent ascites from gynecologic malignancies that underwent either TPC or LVP. Data on procedural complications and hospital admissions were extracted. A cost-effectiveness analysis with Markov modeling was performed comparing TPC and LVP. Statistical analyses include base case calculation, Monte Carlo simulations and deterministic sensitivity analyses. RESULTS: There were no significant differences between the cohorts in the average number of hospital days (p = 0.21) or emergency department visits (p = 0.69) related to ascites. Palliative care was more often involved in the care of patients who had a TPC. The base case calculation showed TPC to be the more cost-effective strategy with a slightly lower health benefit (0.22980 versus 0.22982 QALY) and lower cost ($3043 versus $3868) relative to LVP (ICER of LVP compared to TPC: $44,863,103/QALY). Probabilistic sensitivity analysis showed TPC was the more cost-effective strategy in 8028/10,000 simulations. Deterministic sensitivity analysis showed TPC to be more cost-effective if its complication risk was >0.81% per 22 days or its procedural cost of TPC insertion was >$1997. When varying the cost of complications, TPC was more cost-effective if the cost of its complication was less than $49,202. CONCLUSIONS: TPC is the more cost-effective strategy when compared to LVP in patients with recurrent ascites from gynecological malignancy.

Clinical characteristics and outcomes in those with primary extrahepatic malignancy and malignant ascites.

BACKGROUND: Malignancy-related ascites accounts for approximately 10% of causes of ascites. Our AIM was to characterize the ascites fluid and correlate clinical outcomes in those with extrahepatic malignancy and ascites. METHODS: 241 subjects with extrahepatic solid tumors and ascites were reviewed from 1/1/2000 to 12/31/2019, 119 without liver metastasis and 122 with liver metastasis. RESULTS: Ascites fluid consistent with peritoneal carcinomatosis (PC) was most common, 150/241 (62%), followed by fluid reflecting the presence of portal hypertension (PH), 69/241 (29%). 22/241 (9%) had low SAAG and low ascites fluid total protein, with evidence of PC on cytology and or imaging in 20/22. Lung cancer was the most common malignancy in subjects with ascites due to PC at 36/150 (24%), pancreatic cancer was the most common in subjects with ascites with features of PH at 16/69 (23%). Chemotherapy or immunotherapy alone was the most common management approach. Significantly higher 5-year, 3-year and 1-year mortality rate were noted in subjects with evidence of PC on cytology/imaging versus subjects with no evidence of PC, and in subjects with liver metastasis compared to subjects without liver metastasis. Subjects with pancreatic cancer and evidence of PC on cytology/imaging had higher 1 and 5-year mortality rates compared to subjects without PC. CONCLUSIONS: Ascites in solid tumor malignancy is most commonly due to PC. We also observed ascites fluid with characteristics of PH in 29% of subjects. Higher mortality rates in subjects with peritoneal carcinomatosis and liver metastasis were noted. These findings may help inform prognosis and treatment strategies.

MS275 as Class I HDAC inhibitor displayed therapeutic potential on malignant ascites by iTRAQ-based quantitative proteomic analysis.

BACKGROUND: Malignant ascites is a manifestation of end stage events in a variety of cancers and is associated with significant morbidity. Epigenetic modulators play a key role in cancer initiation and progression, among which histone deacetylases (HDACs) are considered as one of the most important regulators for various cancer development, such as liver cancer, ovarian cancer, and pancreatic cancer et al. Thus, in this paper, we sought to explore the therapeutic effect of HDAC inhibitor on malignant ascites. METHODS: In this report, we tested the therapeutic effect of different isoform selective HDAC inhibitors (Class I HDACI MS275, Class IIa HDACI MC1568, pan-HDAC inhibitors SAHA) on malignant ascites in vitro and in vivo. We further used proteome analysis to find the potential mechanisms for malignant ascites therapy. RESULTS: Among the different isoform-selective HDAC inhibitors, the class I selective HDACI, MS275, exhibited preferential inhibition on various ascites cells. MS275 could induce cell cycle arrest in G0/G1 phase and promote apoptosis on ascites cells. Through proteome analysis, we found MS275 could downregulate proteins related to cell cycle progression, such as CDK4, CDC20, CCND1; MS275 could upregulate pro-apoptosis proteins such as PAPR1, LMNB2 and AIFM1; in addition, MS275 could change the expression of tumorigenic proteins related to the specific malignant ascites bearing tumors, such as TSP1 and CDK4 for bladder cancer. We then confirmed that abemaciclib (CDK4/6 selective inhibitor) could inhibit the proliferation of ascites cells, and the combination of abemaciclib and MS275 had synergistic anti-tumor effect. Finally, we found that MS275 could in vivo inhibit malignant ascites progression (ascites volume: 2.9 ± 1.0 mL vs 7.5 ± 1.2 mL, p < 0.01), tumor growth, and prolong 66% of the life-span when compared with the untreated group. CONCLUSION: This present research revealed that the class I selective HDAC inhibitor, MS275, could effectively inhibit malignant ascites development and tumor growth via multiple pathways. These results indicated that HDACI could have great potential for clinical therapy of malignant ascites.

Clinical practice guideline for the treatment of malignant ascites: section summary in Clinical Practice Guideline for peritoneal dissemination (2021).

Patients with peritoneal dissemination (PD) caused by abdominal malignancies are often associated with massive ascites, which shows extremely dismal prognosis because of the discontinuation of systemic chemotherapy mostly due to poor performance status. Many treatment methods, such as simple drainage, peritoneovenous shunting (PVS) and cell-free and concentrated reinfusion therapy (CART), have been used for symptom relief. However, the clinical efficacies of these methods have not been fully investigated yet. Recently, we developed the Clinical Practice Guideline for PD caused by various malignancies according to "Minds Clinical Practice Guideline Development Guide 2017". In this guideline, we systematically reviewed information on clinical diagnosis and treatments for PD using PubMed databases (2000 - 2020), and clarified the degree of recommendation for clinical questions (CQ). The evidence level was divided into groups by study design and quality. The literature level and a body of evidence were evaluated in reference to the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system. Based on the results of systematic review, the strength of the recommendations was evaluated at a consensus meeting of the Guideline Committee. This is the English synopsis of the part of treatment of malignant ascites in Clinical Practice Guideline for PD, 2021 in Japanese. The guidelines summarize the general aspect of the treatment of malignant ascites and statements with recommendation strengths, evidence levels, agreement rates and future perspective for four raised clinical questions.

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.

Spheroid Formation and Peritoneal Metastasis in Ovarian Cancer: The Role of Stromal and Immune Components.

Ovarian cancer (OC) is one of the most common gynecological cancers, with the worst prognosis and the highest mortality rate. Peritoneal dissemination (or carcinomatosis) accompanied by ascites formation is the most unfavorable factor in the progression and recurrence of OC. Tumor cells in ascites are present as either separate cells or, more often, as cell aggregates, i.e., spheroids which promote implantation on the surface of nearby organs and, at later stages, metastases to distant organs. Malignant ascites comprises a unique tumor microenvironment; this fact may be of relevance in the search for new prognostic and predictive factors that would make it possible to personalize the treatment of patients with OC. However, the precise mechanisms of spheroid formation and carcinomatosis are still under investigation. Here, we summarize data on ascites composition as well as the activity of fibroblasts and macrophages, the key stromal and immune components, in OC ascites. We describe current knowledge about the role of fibroblasts and macrophages in tumor spheroid formation, and discuss the specific functions of fibroblasts, macrophages and T cells in tumor peritoneal dissemination and implantation.

[Effect of Kansui Radix stir-fried with vinegar on fecal metabolomics in Walker-256 rats with ascites].

Utilizing metabolomics technology, this study explored the change of fecal endogenous metabolites in Walker-256 rats with malignant ascites after the administration with Kansui Radix(KR) stir-fried with vinegar(VKR), sought the potential biomarkers in feces which were related to the treatment of malignant ascites by VKR and revealed the biological mechanism of water-expelling effect of VKR. Ultra-fast liquid chromatography-quadrupole-time-of-flight mass spectrometry(UFLC-Q-TOF-MS) was employed to detect the feces of rats in all groups. Principle component analysis(PCA) and partial least squares discriminant analysis(PLS-DA) were conducted to achieve pattern recognition. Combining t-test and variable importance in the projection(VIP) enabled the screening of potential biomarkers for the malignant ascites. Metabolic pathway analysis was accomplished with MetaboAnalyst. Correlation analysis was finally conducted integrating the sequencing data of gut microbiota to elucidate the mechanism underlying the water-expelling effect of VKR. The results showed that both KR and VKR could restore the abnormal metabolism of model rats to some extent, with VKR being inferior to KR in the regulation. Eleven potential biomarkers were identified to be correlated with the malignant ascites and five metabolic pathways were then enriched. Four kinds of gut microbiota were significantly related to the potential biomarkers. The water-expelling effect of VKR may be associated with the regulation of phenylalanine metabolism, biosynthesis of phenylalanine, tyrosine and tryptophan, tryptophan metabolism, glycerophospholipid metabolism, and glycosylphosphatidylinositol(GPI)-anchor biosynthesis. This study can provide a scientific basis for comprehensive understandings of the interaction between gut microbiota and host which has relation to the water-expelling effect of VKR and guide the reasonable clinical application of VKR.

[Chemical ingredient groups B and C in Kansui Radix stir-fried with vinegar affect diversity of gut microbiota in rat model of malignant ascites induced by Walker-256 cells].

This study aims to explore the effects of chemical ingredient groups B and C in Kansui Radix stir-fried with vinegar on the diversity of gut microbiota in the rat model of malignant ascites, identify the key differential microbial taxa, and reveal the biological mechanism of water-expelling effect of the two chemical ingredient groups. The rat model of malignant ascites induced by Walker-256 cells was established, and phenolphthalein was used as the positive drug. The rats were orally administrated with corresponding agents for consecutive 7 days. On day 6, fresh feces samples were collected from the rats, and 16 S rDNA high-throughput sequencing and GC-MS were employed to determine the composition of gut microbiota and the content of short-chain fatty acids, respectively. On day 7, serum and intestinal tissue samples were collected for the determination of related indicators. Compared with the control group, the model group showed decreased feces volume and urine volume(P<0.01), increased volume of ascites and levels of Na~+, K~+, and Cl~- in urine(P<0.01), down-regulated mRNA and protein levels of intestinal AQP8(P<0.01), lowered abundance of beneficial Lactobacillus(P<0.01) while risen abundance of potential pathogenic Lachnospiraceae and Anaeroplasma(P<0.01), and reduced content of short-chain fatty acids(P<0.01). Compared with the model group, administration with chemical ingredient groups B and C alleviated all the above indicators(P<0.01). In conclusion, chemical ingredient groups B and C in Kansui Radix stir-fried with vinegar could alleviate the disordered gut microbiota in rats with malignant ascites to expel water through increasing the abundance of beneficial Lactobacillus and reducing the abundance of harmful Lachnospiraceae and Anaeroplasma. This study can provide a reference for the reasonable clinical application of Kansui Radix stir-fried with vinegar.

Autotaxin in ascites promotes peritoneal dissemination in pancreatic cancer.

Peritoneal dissemination and malignant ascites in pancreatic ductal adenocarcinoma (PDAC) patients represent a major clinical issue. Lysophosphatidic acid (LPA) is a lipid mediator that modulates the progression of various cancers. Based on the increasing evidence showing that LPA is abundant in malignant ascites, we focused on autotaxin (ATX), which is a secreted enzyme that is important for the production of LPA. This study aimed to elucidate the importance of the ATX-LPA axis in malignant ascites in PDAC and to determine whether ATX works as a molecular target for treating peritoneal dissemination. In a PDAC peritoneal dissemination mouse model, the amount of ATX was significantly higher in ascites than in serum. An in vitro study using two PDAC cell lines, AsPC-1 and PANC-1, showed that ATX-LPA signaling promoted cancer cell migration via the activation of the downstream signaling, and this increased cell migration was suppressed by an ATX inhibitor, PF-8380. An in vivo study showed that PF-8380 suppressed peritoneal dissemination and decreased malignant ascites, and these results were validated by the biological analysis as well as the in vitro study. Moreover, there was a positive correlation between the amount of ATX in ascites and the degree of disseminated cancer progression. These findings demonstrated that ATX in ascites works as a promotor of peritoneal dissemination, and the targeting of ATX must represent a useful and novel therapy for peritoneal dissemination of PDAC.