Ascites In Gastric Cancer Patients Research Articles

The PVDF-HFP/Ag NWs-based wide electrochemical stability window ECL system for miRNA 21 detection in gastric cancer ascites

Due to the limitation of the electrochemical stability window (ESW), the high potential usually led to more side reactions during the electrochemical reaction. Therefore, a novel electrochemiluminescence (ECL) sensor with wide ESW was constructed in this study. Poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP)/silver nanowires (Ag NWs) composite was used as the substrate of the ECL biosensor. PVDF-HFP was good mechanical strength, high temperature stability and electrochemical stability. Meanwhile, Ag NWs with excellent electrical conductivity, light transmission and flexibility were employed to improve the charge transfer efficiency in the PVDF-HFP and provide binding sites for biomolecules. The optimized ESW of PVDF-HFP/Ag NWs/GCE was up to 3.717 V. Furthermore, titanium nanoclusters (Ti NCs) were synthesized and used as the aggregation-induced ECL (AIECL) probe. In addition, the biosensor achieved the good quantitative detection of miRNA 21 in ascites of gastric cancer patients within the linear range of 1 fM − 1 nM.

CST1 inhibits ferroptosis and promotes gastric cancer metastasis by regulating GPX4 protein stability via OTUB1

Metastasis is an important factor contributing to poor prognosis in patients with gastric cancer; yet, the molecular mechanism leading to this cell behavior is still not well understood. In this study, we explored the role of cysteine protease inhibitor SN (Cystatin SN, CST1) in promoting gastric cancer metastasis. We hypothesized that CST1 could regulate gastric cancer progression by regulating GPX4 and ferroptosis. Whole transcriptome sequencing suggested that the expression of CST1 was significantly increased in metastatic cancer, and high CST1 expression was correlated with a worse prognosis. Our data further confirmed that the overexpression of CST1 may significantly promote the migration and invasion of gastric cancer cells in vitro and enhance liver, lung, and peritoneal metastasis of gastric cancer in nude mice. Meanwhile, high expression of CST1 promoted the epithelial-mesenchymal transition (EMT) of gastric cancer cells. Mechanistically, a co-immunoprecipitation experiment combined with mass spectrometry analysis confirmed that CST1 could interact with GPX4, a key protein regulating ferroptosis. CST1 relieves GPX4 ubiquitination modification by recruiting OTUB1, improving GPX4 protein stability and reducing intracellular reactive oxygen species (ROS), thereby inhibiting ferroptosis and, in turn, promoting gastric cancer metastasis. Moreover, clinical data suggested that CST1 is significantly increased in peripheral blood and ascites of gastric cancer patients with metastasis; multivariate Cox regression model analysis showed that CST1 was an independent risk factor for the prognosis of gastric cancer patients. Overall, our results elucidated a critical pathway through which high CST1 expression protects gastric cancer cells from undergoing ferroptosis, thus promoting its progression and metastasis. CST1 may be used as a new oncological marker and potential therapeutic target for gastric cancer metastasis.

Prevalence and Clinical Implications of Ascites in Gastric Cancer Patients after Curative Surgery.

We aimed to determine the frequency and clinical significance of ascites that developed during the follow-up period in patients who underwent curative resection for gastric cancer. The study included 577 patients with gastric cancer who underwent curative gastrectomy. Among them, 184 showed ascites in postoperative follow-up images. Benign ascites was observed in 131 of 490 patients without recurrence, 48 patients (of 87) with recurrence had malignancy-related ascites, and the remaining 5 patients had ascites only prior to recurrence. In most patients without recurrence (97.7%) and in 50% of patients with malignancy-related ascites, the ascites was small in volume and located in the pelvic cavity at the time that it was first identified. However, with the exception of nine patients, malignancy-related pelvic ascites occurred simultaneously or after obvious recurrence. Of those nine patients who had minimal pelvic ascites before obvious recurrence, only one had a clear association with a malignancy-related ascites. In the multivariate analysis, an age of ≤45 was the only independent risk factor for the occurrence of benign ascites. A small volume of pelvic ascites fluid is common in young gastric cancer patients who do not have recurrence after gastrectomy, regardless of sex. It is rare for ascites to be the first manifestation of recurrence.

Abstract 2895: Extracellular vesicles derived from mesothelial cells promotes the migration and invasion of gastric cancer cells

Abstract Background: Peritoneal dissemination is one of common causes of poor prognosis of patients with gastric cancer (GC). The mechanism of peritoneal metastasis has not been fully elucidated. Recent studies have reported that extracellular vesicles (EVs) play an important role for the intercellular communication in GC microenvironment. The peritoneal dissemination possesses some intercellular communication steps between cancer cells and hostile cells including peritoneal mesothelial cells (PMCs), however, the effect of EVs derived from PMCs on GC cells has not been validated. In the present study, to clarify the intercellular communication we evaluated the effect of EVs from PMCs on the proliferation, migration and invasion of GC cells. Materials and Methods: Four GC cell lines (OCUM12, NUGC3, MKN45, MKN74) and 4 PMCs cell lines were used. PMCs cell lines were primary cultured from ascites of gastric cancer patients. The EVs derived from PMCs were isolated from conditioned medium of PMCs by ultracentrifugation. The EVs derived from PMCs were confirmed by the transmission electron microscope (TEM) using uranyl acetate and the western blotting using EV markers such as CD9, CD63, and CD81. The EVs derived from PMCs were fluorescently labelled using PKH26 and the uptakes of EVs were viewed under a fluorescence microscope. The effect of EVs from PMCs on the proliferation, migration and invasion of GC cells was evaluated by MTT assay, wound healing assay and Matrigel invasion assay respectively. Results: The EVs derived from PMCs showed typical morphology of EVs by TEM, and were positive for EV markers such as CD9, CD63, and CD81 in western blotting. The EVs derived from PMCs significantly suppressed the proliferation of GC cells. On the other hand, the EVs derived from PMCs significantly promoted the migration of OCUM12 and NUGC3 cells, but not MKN45 and MKN74 cells. Furthermore, The EVs derived from PMCs significantly promoted the invasion of OCUM12 and NUGC3 cells. PKH26 labelled EVs derived from PMCs were found in cytoplasm of OCUM12 and NUGC3 cells. Conclusion: The EVs derived from PMCs significantly promoted the migration and invasion of GC cells. The EVs derived from PMCs might be one of factors which associate with the intercellular communication steps in peritoneal dissemination possesses in GC. Citation Format: Atsushi Sugimoto, Masakazu Yashiro, Tomohisa Okuno, Yuichiro Miki, Gen Tsujio, Yurie Yamamoto, Tomohiro Sera, Shuhei Kushiyama, Sadaaki Nishimura, Kenji Kuroda, Shingo Togano, Masaichi Ohira. Extracellular vesicles derived from mesothelial cells promotes the migration and invasion of gastric cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2895.

Inflammation-driven senescence-associated secretory phenotype in cancer-associated fibroblasts enhances peritoneal dissemination

In the tumor microenvironment, senescent non-malignant cells, including cancer-associated fibroblasts (CAFs), exhibit a secretory profile under stress conditions; this senescence-associated secretory phenotype (SASP) leads to cancer progression and chemoresistance. However, the role of senescent CAFs in metastatic lesions and the molecular mechanism of inflammation-related SASP induction are not well understood. We show that pro-inflammatory cytokine-driven EZH2 downregulation maintains the SASP by demethylating H3K27me3 marks in CAFs and enhances peritoneal tumor formation of gastric cancer (GC) through JAK/STAT3 signaling in a mouse model. A JAK/STAT3 inhibitor blocks the increase in GC cell viability induced by senescent CAFs and peritoneal tumor formation. Single-cell mass cytometry revealed that fibroblasts exist in the ascites of GC patients with peritoneal dissemination, and the fibroblast population shows p16 expression and SASP factors at high levels. These findings provide insights into the inflammation-related SASP maintenance by histone modification and the role of senescent CAFs in GC peritoneal dissemination.

Prognostic significance of malignant ascites in gastric cancer patients with peritoneal metastasis: A systemic review and meta-analysis.

BACKGROUNDRecent evidence indicates that malignant ascites may be associated with the high malignancy and poor prognosis of gastric cancer (GC) with peritoneal metastasis (PM), but no robust consensus has been reached until now.AIMTo evaluate the prognostic significance of malignant ascites in GC patients with PM.METHODSTwo independent authors conducted database searches. The searches were performed in the EMBASE, PubMed, and Cochrane Library databases, and the terms used to search included stomach neoplasms, GC, ascites, peritoneal effusion, survival, and survival analysis. Outcomes included overall survival and hazard ratios with 95% confidence intervals (CIs). Three pairs of comparisons for measuring survival were made: (1) Patients with ascites vs those without ascites; (2) Patients with massive ascites vs those with mild to moderate ascites; and (3) Patients with massive ascites vs those with no to moderate ascites.RESULTSFourteen articles including fifteen studies were considered in the final analysis. Among them, nine studies assessed the difference in prognosis between patients with and without malignant ascites. A pooled HR of 1.63 (95%CI: 1.47-1.82, P < 0.00001) indicated that GC patients with malignant ascites had a relatively poor prognosis compared to patients without ascites. We also found that the prognosis of GC patients with malignant ascites was related to the volume of ascites in the six other studies.CONCLUSIONGC patients with malignant ascites tend to have a worse prognosis, and the volume of ascites has an impact on GC outcomes.

Voltage-dependent calcium channel α2δ1 subunit is a specific candidate marker for identifying gastric cancer stem cells.

Purpose: Cancer stem cells (CSCs) are a subpopulation of cancer cells with self-renewal property and responsible for tumor malignancy, progression and drug resistance. Researches on CSC-specific markers in gastric cancer remain limited. Our current study explored the expression of voltage-dependent calcium channel α2δ1 subunit and the potential of using α2δ1 as a CSC marker in gastric cancer. We also compared the specificity of α2δ1 and CD44 in identifying gastric cancer stem cells (GCSCs).Materials and methods: Expression of α2δ1 was analyzed in gastric cancer cell lines, patient-derived xenograft (PDX) models and clinical samples of malignant ascites of gastric cancer patients. α2δ1+ gastric cancer cells were isolated from gastric cancer cell lines. CSC properties of α2δ1+ gastric cancer cells were then verified by subsequent tests both in vitro and in vivo.Results: The expression level of α2δ1 was found to differ drastically among gastric cancer cell lines, PDX models and clinical samples of malignant ascites. α2δ1+ gastric cancer cells sorted from HGC-27 and SGC-7901 cell lines demonstrated significant self-renewal properties, including tumorigenic capacity, sphere-formation capacity and asymmetric differentiation potential. Knockdown of α2δ1 in α2δ1+ HGC-27 significantly inhibited CSC properties and rendered HGC-27 more sensitive to chemotherapy. Flow cytometry showed that α2δ1+ gastric cancer cells accounted for a small fraction of CD44+ gastric cancer cells. Isolated CD44+α2δ1+ HGC-27 cells displayed more significant tumorigenic capacity and sphere-forming capacity compared with their CD44+α2δ1− counterparts.Conclusion: α2δ1+ gastric cancer cells possessed CSC properties. α2δ1 could be a proper marker in identifying GCSCs with superior specificity than CD44. The combination of α2δ1 and CD44 could be used to identify GCSCs with improved accuracy. Knockdown of α2δ1 combined with chemotherapy displayed higher therapeutic efficacy on gastric cancer cells, suggesting that α2δ1 could be a potential target for anticancer treatment.

Abstract 5200: Extracellular vesicles in the ascites from gastric cancer patients play critical roles to promote peritoneal dissemination in the intraperitoneal cancer microenvironment

Abstract Although gastric cancer often develops peritoneal dissemination, the underlying mechanism of peritoneal metastasis is still unclear. Extracellular vesicles (EVs) are known to play roles in cell-cell communication. Here, we investigated the existence of EVs in peritoneal ascites of gastric cancer patients and explored their roles in the intraperitoneal cancer microenvironment. We found that EVs actually existed in peritoneal ascites of advanced gastric cancer patients. On the other hand, immune-fluorescent assay of the ascites by using antibodies against CD14 (Monocytes) and CD45 (Leukocytes) revealed that many macrophages existed along with the cancer cells in the peritoneal cavity. EVs purified from peritoneal ascites with cancer dissemination made peripheral blood mononuclear cells-derived macrophages M2-like phenotype which was confirmed by their morphology and expression of CD163/206 (M2 marker). Next, we purified EVs from the culture medium of gastric cancer cell lines. Gastric cancer-derived EVs induced the M2- differentiation in macrophages and the differentiated macrophages promoted migration ability of gastric cancer cells. Finally, we observed that gastric cancer-derived EVs induced apoptosis of cultured mesothelial cells in vitro. These results suggested that EVs in the ascites of gastric cancer patients are possibly derived from gastric cancer and play critical roles in the intraperitoneal cancer microenvironment by affecting the macrophages phenotype and inducing apoptosis in the mesothelial cells, which would be in part the underlying mechanism of peritoneal metastasis. Citation Format: Atene Ito, shunsuke kagawa, Shuichi Sakamoto, Kazuya Kuwada, Satoru Kikuchi, Shinji Kuroda, Ryuichi Yoshida, Hiroshi Tazawa, Toshiyoshi Fujiwara. Extracellular vesicles in the ascites from gastric cancer patients play critical roles to promote peritoneal dissemination in the intraperitoneal cancer microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5200.

Elevated alpha1-acid glycoprotein in gastric cancer patients inhibits the anticancer effects of paclitaxel, effects restored by co-administration of erythromycin.

Paclitaxel (PTX) which easily elutes into ascites is widely used to treat gastric cancer patients with peritoneal carcinomatosis (PC), but clinical outcomes are suboptimal. Increased concentrations of α1-acid glycoprotein (AGP), an important drug-binding protein, have been reported in the plasma and ascites of cancer patients. This study sought to clarify whether AGP binds to PTX and alters its anticancer effects. AGP concentrations were measured in the serum and ascites of gastric cancer patients with PC and in the serum of healthy volunteers. The in vitro effects of AGP and AGP plus erythromycin (EM) on PTX were evaluated by MTT assays in the gastric cancer cell lines. We also measured AGP concentrations in the ascites of PC model mice and examined the effects of EM plus PTX on PC. The mean AGP concentrations in the serum and ascites of gastric cancer patients with PC were 1524 and 834 μg/mL, respectively, higher than the mean AGP concentration of 650 μg/mL observed in the sera of healthy volunteers. AGP > 400 μg/mL significantly suppressed the cell growth inhibitory effect of PTX in vitro, but the co-administration of EM restored it. Elevated AGP concentrations were observed in the ascites of PC model mice. Administration of PTX alone did not markedly diminish PC, whereas co-administration of PTX and EM significantly reduced PC (p = 0.011). AGP is an important regulatory factor modulating the anticancer activity of intraperitoneal PTX. The co-administration of PTX and EM may be effective in treating gastric cancer patients with PC.

Cell-free and Concentrated Ascites Reinfusion Therapy (CART) for management of massive malignant ascites in gastric cancer patients with peritoneal metastasis treated with intravenous and intraperitoneal administration of Paclitaxel with Oral S-1.

e15042 Background: Peritoneal metastasis is the most frequent and life-threatening types of metastasis in gastric cancer (GC). Massive malignant ascites are often associated with peritoneal metasta...

Cell-free and concentrated ascites reinfusion therapy (CART) for management of massive malignant ascites in gastric cancer patients with peritoneal metastasis treated with intravenous and intraperitoneal paclitaxel with oral S-1

BackgroundMassive malignant ascites originating from peritoneal metastasis of gastric cancer is difficult to control and resistant to chemotherapy. Cell-free and Concentrated Ascites Reinfusion Therapy (CART) is one of the types of apheresis therapy, by which filtered and concentrated ascites containing albumin and globulin is reinfused intravenously to patients. We retrospectively studied the feasibility of intraperitoneal (IP) chemotherapy combined with CART in gastric cancer patients with massive malignant ascites. MethodsPaclitaxel (PTX) was administered via an IP access port implanted in the subcutaneous space. If patient had massive ascites at the start of treatment, paracentesis was performed through a percutaneous IP catheter and then CART was performed. PTX was administered through the catheter until the ascites diminished. ResultsA total of 127 CART procedures in 30 patients were analyzed. The average volume of processed ascites was 3.1 L, which was concentrated to 0.33 L containing 85.5 g protein on average. Significant increases in urine volume, serum total protein and albumin level were found after the CART. Increase in body temperature (0.3 °C), decrease in platelet count (3.8 × 104/μl), and changes in blood pressure (2 mm Hg) were found after the CART procedure, but no clinically significant adverse event was experienced. The median survival time and 1-year survival of 30 patients who received IP chemotherapy combined with the CART procedure was 10.2 months and 43.3% respectively. ConclusionsIP chemotherapy combined with CART might be a promising strategy for patients with massive malignant ascites originating from peritoneal metastasis of gastric cancer.

High antitumor activity of pladienolide B and its derivative in gastric cancer

The antitumor activity of pladienolide B, a novel splicing inhibitor, against gastric cancer is totally unknown and no predictive biomarker of pladienolide B efficacy has been reported. We investigated the antitumor activity of pladienolide B and its derivative on gastric cancer cell lines and primary cultured cancer cells from carcinomatous ascites of gastric cancer patients. The effect of pladienolide B and its derivative on six gastric cancer cell lines was investigated using a MTT assay and the mean IC50 values determined to be 1.6 ± 1.2 (range, 0.6–4.0) and 1.2 ± 1.1 (range, 0.4–3.4) nM, respectively, suggesting strong antitumor activity against gastric cancer. The mean IC50 value of pladienolide B derivative against primary cultured cells from 12 gastric cancer patients was 4.9 ± 4.7 nM, indicative of high antitumor activity. When 18 SCID mice xenografted with primary cultured cells from three patients were administered the pladienolide B derivative intraperitoneally, all tumors completely disappeared within 2 weeks after treatment. Histological examination revealed a pathological complete response for all tumors. In the xenograft tumors after treatment with pladienolide B derivative, immature mRNA were detected and apoptotic cells were observed. When the expressions of cell-cycle proteins p16 and cyclin E in biopsied gastric cancer specimens were examined using immunohisctochemistry, positivities for p16 and cyclin E were significantly and marginally higher, respectively, in the low-IC50 group compared with the high-IC50 group, suggesting the possibility that they might be useful as predictive biomarkers for pladienolide B. In conclusion, pladienolide B was very active against gastric cancer via a mechanism involving splicing impairment and apoptosis induction.

Pharmacokinetics of docetaxel in gastric cancer patients with malignant ascites

The purpose of this study was to investigate whether intravenous (i.v.) administration allowed docetaxel to penetrate ascites in gastric cancer patients with peritoneal dissemination. Twelve patients with disseminated gastric carcinoma were enrolled in the study. All patients received docetaxel-containing drug regimens: i.v. administration of 40 mg/m(2) docetaxel in 6 patients, and 60 mg/m(2) in the remainder. Docetaxel concentrations in the plasma and ascites were measured. Docetaxel was detected in the ascites of 4 patients in the 40 mg/m(2) group and 5 patients in the 60 mg/m(2) group. The highest concentration of docetaxel in plasma was detected at immediately after administration (median: 1,660 ng/mL, 501-2,560 ng/mL), after which it gradually decreased. The highest concentration of docetaxel in ascites was observed at ~7 h after administration and varied among cases (median: 18 ng/mL, 11-52 ng/mL). Intravenous administration allows to penetrate ascites in gastric cancer patients with peritoneal dissemination.

Lentivirus-mediated RNA silencing of c-Met markedly suppresses peritoneal dissemination of gastric cancer in vitro and in vivo

To investigate the expression of c-Met in peritoneal free cancer cells isolated from human gastric cancer ascites, and its relationship to peritoneal dissemination of gastric cancer. Peritoneal free cancer cells (PFCCs) were isolated from ascites specimens of gastric cancer patients. c-Met expression in PFCCs was detected with immunocytochemistry. In human gastric cancer cell line SGC7901, c-Met expression was detected using RT-PCR and Western blot, and was suppressed with lentivirus-mediated RNAi. The proliferation of SGC7901 cells was measured using MTT assay, and the invasion ability was detected with invasion assay. The adhesion of SGC7901 cells to peritoneum was observed in human peritoneal mesothelial cells (HPMCs) monolayer in vitro and in mice in vivo. PFCCs were isolated from ascites of 6 out of 10 gastric cancer patients. c-Met expression in PFCCs was detected in 5 of the 6 gastric cancer patients. In SGC7901 cells, Lentivirus-mediated RNAi significantly reduced both c-Met mRNA and protein expression, which resulted in suppressing the cell proliferation, invasion and adhesion to peritoneum. The expression of α3β1 integrin and E-cadherin was significantly inhibited in SGC7901 cells transfected with Lenti-miRNAc-Met. In the peritoneal dissemination model of gastric cancer, intraperitoneal injection of Lenti-miRNAc-Met markedly suppressed the tumor Progression of SGC7901 cells. c-Met is expressed in PFCCs from the ascites of gastric cancer patients. Down-regulation of c-Met expression markedly suppresses the multistep process of peritoneal dissemination, thus may be a potential target for the treatment of gastric cancer.

Induction of a tumour-specific CTL response by exosomes isolated from heat-treated malignant ascites of gastric cancer patients

Purpose: Tumour cell-derived exosomes may represent a novel type of cancer vaccine. However, the immunogenicity of exosomes derived from tumour cells has been shown to be poor. Therefore, in this study, exosome immunogenicity following heat treatment of exosomes from malignant ascites obtained from gastric cancer patients was evaluated.Materials and methods: Tumour-derived exosomes were isolated from heat-treated and untreated malignant ascites of gastric cancer patients using serial centrifugation and sucrose gradient ultracentrifugation. Next, in vitro experiments were performed to investigate the influence of heat treatment on exosome immunogenicity.Results: Exosomes from heat-treated malignant ascites of gastric cancer patients (HS exosomes) were found to contain higher concentrations of heat shock proteins, Hsp70 and Hsp60, than exosomes derived from untreated malignant ascites obtained from gastric cancer patients. Additional in vitro studies suggest that exosomes derived from heat-treated malignant ascites are able to promote dendritic cell (DC) maturation and induce a tumour-specific cytotoxic T lymphocyte (CTL) response.Conclusions: Overall, these results demonstrate that exposure to heat stress can improve the immunogenicity of exosomes obtained from malignant ascites of gastric cancer patients.

Analysis of pO2 in malignant ascites of patients with peritoneal dissemination of gastric cancer.

63 Background: Peritoneal metastasis is considered to develop from carcinoma cells detached from the serosal surface of the primary site and dispersed in the peritoneal cavity. And oxygen is one of the most important environmental factors for tumor development. To investigate the oxygenation condition in the abdominal cavity, that is largely unknown, we collected ascitic fluid from patients with peritoneal dissemination of gastric cancer and measured pO2 of it. Methods: In 19 patients with peritoneal dissemination of gastric cancer, who had a considerable amount of ascites and was receiving systemic and/or intraperitoneal chemotherapy, ascitic fluid was collected at the bedside in room air, and its pH, pCO2 and pO2 were measured using a blood gas analyzer immediately. Results: In 19 patients, pH of malignant ascites was significantly lower than that of arterial blood (7.39 ± 0.069 vs 7.44 ± 0.025 mmHg, p &lt; 0.05). pCO2 tended to be higher in ascites than in arterial blood. Unexpectedly, pO2 in malignant ascites showed relatively high values (85.47 ± 23.31 mmHg), which were mostly the same as that of arterial blood (97.19 ± 10.40 mmHg, p = 0.149), and appeared to be higher than that in solid tumor tissue. Conclusions: Malignant ascites in gastric cancer patients showed an unexpectedly high oxygen tension, which was almost the same as that of arterial blood. The hyperpermeability condition may enable efficient oxygen delivery to peritoneal fluid via the microvessels lining the peritoneal cavity. Since the oxygen level critically affects the sensitivity of tumor cells to chemotherapeutic agents through metabolic transformation, aerobic conditions may be beneficial for the progression of peritoneal metastasis and also clinically important in considering the efficacy of chemotherapy. No significant financial relationships to disclose.