Molecular Mechanisms and Potential Rationale of Immunotherapy in Peritoneal Metastasis of Advanced Gastric Cancer

Effect of PRKD3 on cell cycle in gastric cancer progression and downstream regulatory networks

Protein kinase D3 (PRKD3), belonging to the protein kinase D family, significantly influences tumor development and progression. The role of PRKD3 in advancing gastric cancer (GC) and its effects on the cell cycle are not well understood, necessitating detailed investigation. Assessment of PRKD3 expression in both malignant and normal gastric tissues was performed using bioinformatics databases. The influence of PRKD3 on GC's malignant characteristics was evaluated through in vitro experiments utilizing cell line models of GC. Additionally, proteomic analyses were conducted to investigate the potential mechanisms of PRKD3 in GC progression. PRKD3 was notably overexpressed in GC tissues, correlating with adverse outcomes for patients. PRKD3 knockdown impaired GC cell malignancy, manifesting as a 2.12-fold decline in proliferation(p < 0.01), 2.64-fold suppression of migration(p < 0.01), 2.16-fold inhibition of invasion(p < 0.01), and G2/M phase arrest. Proteomic and Western blot analyses had revealed a substantial enrichment in differentially expressed proteins (DEPs) associated with tumor-related signaling pathways, including FoxO and p53, which was paralleled by significant alterations in the levels of key cell cycle proteins such as CDK1, CyclinB1, CHK1 and PLK1, with a 6.8-fold elevation in CHK1 levels(p < 0.05). The overexpression of PRKD3 was intricately linked with the aggressive behaviors of GC. Targeting PRKD3 activity offers potential for effective treatments of GC.

Gastric cancer peritoneal metastasis: a bibliometric study from 2000 to 2024 using VOSviewer software

Background

Gastric cancer remains a prevalent malignancy worldwide, with peritoneal metastasis being the predominant form of recurrence and metastasis, which are clear predictors of prognosis. The aim of this comprehensive bibliometric analysis was to assess the current status of the research landscape and to identify impending trends in gastric cancer peritoneal metastasis (GCPM).

Methods

Relevant studies of GCPM were retrieved from the Web of Science Core Collection database. Qualified articles were screened based on the inclusion and exclusion criteria for further analysis. The selected publications were then subjected to bibliometric analysis utilizing VOSviewer software.

Results

In total, 1,100 publications were included for analysis. The results revealed a consistent upward trend in the number of publications annually from 2000 to 2024, with an anticipated continuation of this growth in future research. The National Cancer Center Japan, emerged as the institution with the most publications and Professor Kodera and Annals of Surgical Oncology were identified as the most influential author and journal, respectively, in the domain of GCPM. In terms of international collaborations, the USA, Japan, and France were the most engaged countries. Yonemura was recognized as the most frequently cited author. Gastrectomy, systemic chemotherapy, and intraperitoneal therapy are the current research hotspots within this domain.

Conclusion

Research related to GCPM had rapidly increased over the past two decades. These findings identify the most influential countries, institutions, authors, journals, and academic collaboration networks, while also clarifying hotspots and future trends in GCPM research.

Efficacy and safety of different drugs in patients with HER2-positive gastric cancer: network meta-analysis

BACKGROUND

In the past decade, there has been a significant advancement in targeted therapy and immunotherapy, leading to the discovery of new drugs and changes in the treatment approach for patients with HER2-positive gastric cancer. Although several drugs are available for treating these patients, there is still no consensus on their selection, and there has been limited direct or indirect comparison among them.

OBJECTIVE

To address this gap, a network meta-analysis was conducted to assess the efficacy and safety of different drugs used in the treatment of HER2-positive gastric cancer.

METHODS

By searching through databases such as PubMed, Embase, Web of Science, and Cochrane Library, we identified 16 randomized controlled trials that involved a total of 4485 patients and utilized 9 different intervention measures.

RESULTS

Based on the current evidence, compared with chemotherapy alone, the hazard ratio (HR) of overall survival (OS) and progression-free survival (PFS) in gastric cancer patients treated with nivolumab were [hazard ratio (HR): 2.61 95%confidence interval (CI) (1.51, 4.51)] and [hazard ratio (HR): 2.01 95% confidence interval (CI) (1.18, 3.42)], respectively. Compared with chemotherapy alone, the hazard ratio (HR) of overall survival (OS) and progression-free survival (PFS) in gastric cancer patients treated with trastuzumab deruxtecan were [hazard ratio (HR): 1.7 95% confidence interval (CI) (1.13, 2.56)] and [hazard ratio (HR): 2.13 95% confidence interval (CI) (1.42, 3.22)], respectively. It is suggested that nivolumab and trastuzumab deruxtecan can effectively prolong overall survival (OS) and progression-free survival(PFS) in patients with HER2-positive gastric cancer, while also reducing the risk of adverse events to some extent. Therefore, these two regimens, nivolumab and trastuzumab deruxtecan, are considered to be effective and safe options for the treatment of patients with HER2-positive gastric cancer.

CONCLUSIONS

In previous studies, trastuzumab-based chemotherapy has been a common treatment for HER2-positive gastric cancer. To a certain extent, our study provides a reliable direction for future treatment options for HER2-positive gastric cancer.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42023420941.

Paclitaxel hyperthermia suppresses gastric cancer migration through MiR-183-5p/PPP2CA/AKT/GSK3β/β-catenin axis

BACKGROUND

Gastric cancer (GC), a prevalent malignant tumor which is a leading cause of death from malignancy around the world. Peritoneal metastasis accounts for the major cause of mortality in patients with GC. Despite hyperthermia intraperitoneal chemotherapy (HIPEC) improves the therapeutic effect of GC, it's equivocal about the mechanism under HIPEC.

METHODS

MiR-183-5p expression was sifted from miRNA chip and detected in both GC patients and cell lines by qRT-PCR. Gene interference and rescue experiments were performed to identified biological function in vitro and vivo. Next, we affirmed PPP2CA as targeted of miR-183-5p by dual luciferase reporter assay. Finally, the potential relationship between HIPEC and miR-183-5p was explored.

RESULTS

MiR-183-5p is up-regulated in GC and associated with advanced stage and poor prognosis. MiR-183-5p accelerate GC migration in vitro which is influenced by miR-183-5p/PPP2CA/AKT/GSK3β/β-catenin Axis. HIPEC exerts migration inhibition via attenuating miR-183-5p expression.

CONCLUSION

MiR-183-5p can be used as a potential HIPEC biomarker in patients with CC.

Peritoneal Washing Cytology Positivity in Gastric Cancer: Role of Lymph Node Metastasis as a Risk Factor

PURPOSE

Peritoneal washing cytology (PWC) is a widely used diagnostic tool for detecting peritoneal metastasis of advanced gastric cancer. However, the prognosis of patients with positive PWC remains poor even after gastrectomy, and treatments vary among institutions and eras. In this study, we identified the clinical factors that can help predict cytology-positive (CY(+)) gastric cancer.

MATERIALS AND METHODS

We retrospectively reviewed the national data of patients with gastric cancer from 2019, as provided by the Information Committee of the Korean Gastric Cancer Association. Of the 13,447 patients with gastric cancer, 3,672 underwent PWC. Based on cytology results, we analyzed the clinicopathological characteristics and assessed the possibility of CY(+) outcomes in relation to T and N stages.

RESULTS

Of the 3,270 patients who underwent PWC without preoperative chemotherapy, 325 were CY(+), whereas 2,945 were negative. CY(+) was more commonly observed in patients with Borrmann type IV gastric cancer, an undifferentiated histological type, and advanced pathological stages. Multivariate analysis revealed Borrmann type IV (odds ratio [OR], 1.821), tumor invasion to T3-4 (OR, 2.041), and lymph node metastasis (OR, 3.155) as independent predictors of CY(+). Furthermore, for circular tumor location, the N stage emerged as a significant risk factor for CY(+), particularly when the tumor was located on the posterior wall (PW) side.

CONCLUSIONS

Lymph node metastasis significantly affects CY(+) outcomes, particularly when the tumor is located on the PW side. Therefore, PWC should be considered not only in suspected serosal exposure cases but also in cases of lymph node metastasis.

Characterizing the Immune Environment in Peritoneal Carcinomatosis: Insights for Novel Immunotherapy Strategies

BACKGROUND OR PURPOSE

Carcinomatosis, a distinct pattern of metastatic cancer in the peritoneal cavity, poses challenges for treatment and has limited therapeutic options. Understanding the immune environment of peritoneal surface malignancies is crucial for developing effective immunotherapeutic approaches. This study characterizes soluble immune mediators in the peritoneal fluid of patients with and without carcinomatosis to identify targets for novel treatment strategies.

PATIENTS AND METHODS

Serum and peritoneal fluid samples were collected from surgical patients, and a multianalyte analysis was performed using the Luminex platform. Patient characteristics, tumor sites, and sample collection details were recorded. Soluble immune mediator levels were measured and compared between peritoneal fluid and serum samples and among clinical subgroups. Statistical analysis was conducted to assess differences in analyte concentrations and correlations between samples.

RESULTS

There were 39 patients included in the study, with varying surgical indications. Significant differences were observed in soluble immune mediator levels between peritoneal fluid and serum, with peritoneal fluid exhibiting lower concentrations. Carcinomatosis was associated with elevated levels of proinflammatory mediators, including IL-6 and IL-8, while adaptive immune response markers were low in peritoneal fluid.

CONCLUSIONS

The peritoneal immune microenvironment in carcinomatosis favors innate immunity, presenting a challenging environment for effective antitumor response. High levels of proinflammatory mediators suggest potential targets for intervention, such as the IL-6 axis, FGF2, IL-8, and CCL2; these could be explored as potential mitigators of malignant ascites and enhance anti-tumor immune responses. These findings provide valuable insights for developing immunotherapy strategies and improving outcomes in patients with peritoneal carcinomatosis.

Tumor-mesothelium HOXA11-PDGF BB/TGF β1-miR-181a-5p-Egr1 feedforward amplifier circuity propels mesothelial fibrosis and peritoneal metastasis of gastric cancer

A proportion of gastric cancer (GC) patients suffer from peritoneal metastasis (PM) in the late stage of tumor and these patients have a poor prognosis. To provide more care for GC patient with PM, a deeper exploration of the molecular characteristics of GC-PM is needed. Here we performed the in vitro and in vivo study to illustrate the effect of HOXA11 over-expressed GC cells on peritoneal mesothelial cells (HMrSV5), transcriptomics analyses of HMrSV5 cells co-cultured with HOXA11 over-expressed GC cells, counterparts or alone, cytokine array analyses of serum-free culture medium of HOXA11 over-expressed GC cells, we validated our findings through genetic manipulation of HMrSV5 cells and neutralizing antibodies targeting cytokines secreted by HOXA11 over-expressed GC cells in vitro, as well as utilized human peritoneal metastatic lesions to validate expression of potential targets. We identified that HOXA11 over-expressed GC cells strongly propelled mesothelial fibrosis in vivo and in vitro, and HOXA11 regulated paracrine and autocrine of PDGF BB and TGF β1 in GC cells to propel mesothelial fibrosis. Meanwhile, HOXA11 over-expressed GC cells drove PDGF BB and TGF β1 secretion to activate developmental-process related genes in HMrSV5 cells, including Egr1, which processes dependent on miR-181a-5p. Then, Egr1 could mediate peritoneal mesothelial fibrosis. Correspondingly, Egr1 over-expressed HMrSV5 cells supported migration and peritoneal dissemination of GC cells. Together our results suggest that a feedforward amplifier circuity governing GC cells and mesothelial cells in peritoneum contribute to peritoneal metastasis of GC cells.

Phase I/II Clinical Study of PRaG Regimen Combined With Intraperitoneal Infusion of PD-1 Inhibitor for Advanced Refractory Solid Tumors With Cancerous Ascites (PRaG4.0P Study)

Objective: The prognosis of malignant tumors with peritoneal metastases and cancerous ascites has generally been poor, with limited treatment options. The PRaG regimen, which comprised of hypofractionated radiotherapy, programmed cell death-1 (PD-1) inhibitor, and granulocyte-macrophage colony-stimulating factor (GM-CSF), showed a survival advantage in patients with advanced solid tumors who failed at least the first line of standard systemic treatment. Intraperitoneal infusion of PD-1 inhibitors may be a novel therapeutic strategy for managing malignant ascites. Integrating the PRaG regimen with intraperitoneal perfusion of a PD-1 inhibitor might control malignant ascites and provide further survival benefits in these patients. This proposed study aims to investigate the safety and efficacy of intraperitoneal infusion of serplulimab in combination with the PRaG regimen in patients with simultaneous advanced solid tumors and cancerous ascites who fail at least the first-line treatment. Methods: This proposed study is a prospective, single-arm, open-label, multicenter clinical trial. All eligible patients will receive 2 cycles of intensive treatment, a combination of PRaG regimen with an intraperitoneal infusion of PD-1 inhibitor. The patients who are beneficially treated with intensive treatment will receive consolidation treatment every 2 weeks until ascites disappear, disease progression occurs, intolerable toxicity occurs, or for up to 1 year. Phase I of this study will be conducted using a modified 3 + 3 design. The dose of intraperitoneal infusion of PD-1 inhibitor for phase II will be determined according to dose-limiting toxicity evaluation in the phase I study. Conclusion: This prospective, open-label, multicenter study will potentially lead to intraperitoneal perfusion of a PD-1 inhibitor being a new strategy for malignant ascites patients and provide a meaningful efficacy and safety of the combination of PRaG regimen with an intraperitoneal infusion of PD-1 inhibitor for these patients.

Immune profile of patients with peritoneal carcinomatosis selected for CRS-HIPEC therapy

Cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) is a treatment option for peritoneal carcinomatosis (PC) from colorectal cancer (CRC), which is otherwise a terminal stage of disease. Nevertheless, survival outcomes are only marginally superior to other treatments. This fact highlights the need for better strategies to control intra-abdominal disease recurrence after CRS-HIPEC, including the complementary use of immunotherapies. The aim of this study was therefore to investigate the immune phenotype of T cells in patients with PC. Fifty three patients with CRC (34 patients with PC and 19 patients without PC) were enrolled in a prospective study (clinicaltrials.gov: NCT04108936). Peripheral blood and omental fat were collected to isolate peripheral blood mononuclear cells (PBMCs) and adipose tissue mononuclear cells (ATMCs). These cells were analysed by flow cytometry using a panel focused upon T cell memory differentiation and exhaustion markers. We found a more naïve profile for CD8+ T cells in peripheral blood and intra-abdominal fat of PC patients compared to comparator group (CG) patients. Furthermore, there was an over-representation of CD4+ T cells expressing inhibitory receptors in adipose tissue of PC patients, but not in blood. Our description of intraperitoneal T cell subsets gives us a better understanding of how peritoneal carcinomatosis shapes local immune responses.

Regional Immunotherapy for Peritoneal Carcinomatosis in Gastroesophageal Cancer: Emerging Strategies to Re-Condition a Maladaptive Tumor Environment

Peritoneal carcinomatosis originating from gastric/gastroesophageal junction cancer (GC-PC) occurs in a defined subset of gastric cancer patients with unique clinical, pathologic, molecular and immunologic characteristics that create significant obstacles to effective treatment with modern therapy. Although systemic chemo- and immuno- therapy have yielded disappointing results in GC-PC, recent advances in the characterization of GC-PC and peritoneal immune biology present new opportunities for targeted therapeutics. In this review article, we discuss the distinct properties of GC-PC and the peritoneal immune environment as they pertain to current and investigative treatment strategies. We discuss pre-clinical studies and clinical trials relevant to the modulation of the peritoneal environment as a therapeutic intervention in GC-PC. Finally, we present a road map for future combinatorial strategies based on the conception of the peritoneal cavity as a bioreactor. Within this isolated compartment, prevailing immunosuppressive conditions can be altered through regional interventions toward an adaptive phenotype that would support the effectiveness of regionally delivered cellular therapy products. It is hoped that novel combination strategies would promote efficacy not only in the sequestered peritoneal environment, but also via migration into the circulation of tumor-reactive lymphocytes to produce durable systemic disease control, thereby improving oncologic outcome and quality of life in patients with GC-PC.

PRSS2 regulates EMT and metastasis via MMP-9 in gastric cancer

Serine protease 2 (PRSS2) is upregulated in gastric cancer tissues, correlates with poor prognosis and promotes migration and invasion of gastric cancer cells. However, the exact mechanism by which PRSS2 promotes metastasis in gastric cancer is unclear. We examined serum PRSS2 levels in healthy controls and gastric cancer patients by enzyme linked immunosorbent assay (ELISA) and analyzed the correlation between PRSS2 serum level with the clinicopathological characteristics of gastric cancer patients and matrix metalloproteinase-9 (MMP-9) expression. A lentiviral MMP-9 overexpression vector was constructed and used to transfect gastric cancer cells with stable silencing of PRSS2, and migration, invasion and epithelial-mesenchymal transition (EMT) of gastric cancer cells were examined. High serum PRSS2 levels were detected in gastric cancer patients and associated with lymphatic metastasis and TNM stage. Serum PRSS2 was positively correlated with serum MMP-9 level. PRSS2 silencing inhibited EMT, and knock-down of PRSS2 partially abrogated cell metastasis and EMT caused by overexpression of MMP-9. These results suggest that PRSS2 promotes the migration and invasion of gastric cancer cells through EMT induction by MMP-9. Our findings suggest that PRSS2 may be a potential early diagnostic marker and therapeutic target of gastric cancer.

GRB10 is a novel factor associated with gastric cancer proliferation and prognosis

GRB10 and its family members GRB7 and GRB14 were important adaptor proteins. They regulated many cellular functions by interacting with various tyrosine kinase receptors and other phosphorus-containing amino acid proteins. More and more studies have shown that the abnormal expression of GRB10 is closely related to the occurrence and development of cancer. In our current research, expression data for 33 cancers from the TCGA database was downloaded for analysis. It was found that GRB10 was up-regulated in cholangiocarcinoma, colon adenocarcinoma, head and neck squamous carcinoma, renal chromophobe, clear renal carcinoma, hepatocellular carcinoma, lung adenocarcinoma, lung squamous carcinoma, gastric adenocarcinoma and thyroid carcinoma. Especially in gastric cancer, the high GRB10 expression was closely associated with poorer overall survival. Further research showed that the knockdown of GRB10 inhibited proliferation and migration ability in gastric cancer. Also, there was a potential binding site for miR-379-5p on the 3'UTR of GRB10. Overexpression of miR-379-5p in gastric cancer cells reduced GRB10-regulated gastric cancer proliferation and migration capacity. In addition, we found that tumor growth was slower in a mice xenograft model with knock down of GRB10 expression. These findings suggested that miR-379-5p suppresses gastric cancer development by downregulating GRB10 expression. Therefore, miR-379-5p and GRB10 were expected to be potential targets for the treatment of gastric cancer.