Distinct tumor immune microenvironments in primary and metastatic lesions in gastric cancer patients

iRhom2 deficiency reduces sepsis-induced mortality associated with the attenuation of lung macrophages in mice

Sepsis has a high mortality rate and leads to multi-organ failure, including lung injury. Inactive rhomboid protease family protein (iRhom2) has been identified as accountable for the release of TNF-α, a crucial mediator in the development of sepsis. This study aimed to evaluate the role of iRhom2 in sepsis and sepsis-induced acute lung injury (ALI). TNF-α and IL-6 secretion in vitro by peritoneal macrophages from wild-type (WT) and iRhom2 knoukout (KO) mice was assessed by enzyme-linked immunosorbent assay. Cecal ligation and puncture (CLP)-induced murine sepsis model was used for in vivo experiments. To evaluate the role of iRhom2 deficiency on survival during sepsis, both WT and iRhom2 KO mice were monitored for 8 consecutive days following the CLP. For histologic and biochemical examination, the mice were killed 18 h after CLP. iRhom2 deficiency improved the survival of mice after CLP. iRhom2 deficiency decreased CD68+ macrophage infiltration in lung tissues. Multiplex immunohistochemistry revealed that the proportion of Ki-67+ CD68+ macrophages was significantly lower in iRhom2 KO mice than that in WT mice after CLP. Moreover, CLP-induced release of TNF-α and IL-6 in the serum were significantly inhibited by iRhom2 deficiency. iRhom2 deficiency reduced NF-kB p65 and IκBα phosphorylation after CLP. iRhom2 deficiency reduces sepsis-related mortality associated with attenuated macrophage infiltration and proliferation in early lung injury. iRhom2 may play a pivotal role in the pathogenesis of sepsis and early stage of sepsis-induced ALI. Thus, iRhom2 may be a potential therapeutic target for the management of sepsis and sepsis-induced ALI.

Molecular classification and intratumoral heterogeneity of gastric adenocarcinoma

Gastric cancers frequently harbor striking histological complexity and diversity between lesions as well as within single lesions, known as inter- and intratumoral heterogeneity, respectively. The latest World Health Organization Classification of Tumors designated more than 30 histological subtypes for gastric epithelial tumors, assigning 12 subtypes for gastric adenocarcinoma (GAD). Meanwhile, recent advances in genome-wide analyses have provided molecular aspects to the histological classification of GAD, and consequently revealed different molecular traits underlying these histological subtypes. Moreover, accumulating knowledge of comprehensive molecular profiles has led to establishing molecular classifications of GAD, which are often associated with clinical biomarkers for therapeutics and prognosis. However, most of our knowledge of GAD molecular profiles is based on inter-tumoral heterogeneity, and the molecular profiles underlying intratumoral heterogeneity are yet to be determined. In this review, recently established molecular classifications of GAD are introduced in the aspect of pathological diagnosis and are discussed in the context of intratumoral heterogeneity.

Enhanced Therapeutic Potential of Hybrid Exosomes Loaded with Paclitaxel for Cancer Therapy

The advancement of exosome studies has positioned engineered exosomes as crucial biomaterials for the development of advanced drug delivery systems. This study focuses on developing a hybrid exosome system by fusing mesenchymal stem cells (MSCs) exosomes with folate-targeted liposomes. The aim was to improve the drug loading capacity and target modification of exosome nanocarriers for delivering the first-line chemotherapy drug paclitaxel (PTX) and its effectiveness was assessed through cellular uptake studies to evaluate its ability to deliver drugs to tumor cells in vitro. Additionally, in vivo experiments were conducted using a CT26 tumor-bearing mouse model to assess the therapeutic efficacy of hybrid exosomes loaded with PTX (ELP). Cellular uptake studies demonstrated that ELP exhibited superior drug delivery capabilities to tumor cells in vitro. Moreover, in vivo experiments revealed that ELP significantly suppressed tumor growth in the CT26 tumor-bearing mouse model. Notably, for the first time, we examined the tumor microenvironment following intratumoral administration of ELP. We observed that ELP treatment activated CD4+ and CD8+ T cells, reduced the expression of M2 type tumor-associated macrophages (TAMs), polarized TAMs towards the M1 type, and decreased regulatory T cells (Tregs). Our research highlights the considerable therapeutic efficacy of ELP and its promising potential for future application in cancer therapy. The development of hybrid exosomes presents an innovative approach to enhance drug delivery and modulate the tumor microenvironment, offering exciting prospects for effective cancer treatment strategies.

Assessment of programmed death-ligand 1 expression in primary tumors and paired lymph node metastases of gastric adenocarcinoma

BACKGROUND

Anti-programmed death-1/programmed death-ligand 1 (PD-1/PD-L1) immunotherapy has demonstrated promising results on gastric cancer (GC). However, PD-L1 can express differently between metastatic sites and primary tumors (PT).

AIM

To compare PD-L1 status in PT and matched lymph node metastases (LNM) of GC patients and to determine the correlation between the PD-L1 status and clinicopathological characteristics.

METHODS

We retrospectively reviewed 284 GC patients who underwent D2-gastrectomy. PD-L1 was evaluated by immunohistochemistry (clone SP142) using the combined positive score. All PD-L1+ PT staged as pN+ were also tested for PD-L1 expression in their LNM. PD-L1(-) GC with pN+ served as the comparison group.

RESULTS

Among 284 GC patients included, 45 had PD-L1+ PT and 24 of them had pN+. For comparison, 44 PD-L1(-) cases with pN+ were included (sample loss of 4 cases). Of the PD-L1+ PT, 54.2% (13/24 cases) were also PD-L1+ in the LNM. Regarding PD-L1(-) PT, 9.1% (4/44) had PD-L1+ in the LNM. The agreement between PT and LNM had a kappa value of 0.483. Larger tumor size and moderate/severe peritumoral inflammatory response were associated with PD-L1 positivity in both sites. There was no statistical difference in overall survival for PT and LNM according to the PD-L1 status (P = 0.166 and P = 0.837, respectively).

CONCLUSION

Intra-patient heterogeneity in PD-L1 expression was observed between the PT and matched LNM. This disagreement in PD-L1 status may emphasize the importance of considering different tumor sites for analyses to select patients for immunotherapy.

Pre-treatment inflamed tumor immune microenvironment is associated with FOLFIRINOX response in pancreatic cancer

Introduction

Pancreatic adenocarcinoma (PDAC) is an aggressive tumor with limited response to both chemotherapy and immunotherapy. Pre-treatment tumor features within the tumor immune microenvironment (TiME) may influence treatment response. We hypothesized that the pre-treatment TiME composition differs between metastatic and primary lesions and would be associated with response to modified FOLFIRINOX (mFFX) or gemcitabine-based (Gem-based) therapy.

Methods

Using RNAseq data from a cohort of treatment-naïve, advanced PDAC patients in the COMPASS trial, differential gene expression analysis of key immunomodulatory genes in were analyzed based on multiple parameters including tumor site, response to mFFX, and response to Gem-based treatment. The relative proportions of immune cell infiltration were defined using CIBERSORTx and Dirichlet regression.

Results

145 samples were included in the analysis; 83 received mFFX, 62 received Gem-based therapy. Metastatic liver samples had both increased macrophage (1.2 times more, p < 0.05) and increased eosinophil infiltration (1.4 times more, p < 0.05) compared to primary lesion samples. Further analysis of the specific macrophage phenotypes revealed an increased M2 macrophage fraction in the liver samples. The pre-treatment CD8 T-cell, dendritic cell, and neutrophil infiltration of metastatic samples were associated with therapy response to mFFX (p < 0.05), while mast cell infiltration was associated with response to Gem-based therapy (p < 0.05). Multiple immunoinhibitory genes such as ADORA2A, CSF1R, KDR/VEGFR2, LAG3, PDCD1LG2, and TGFB1 and immunostimulatory genes including C10orf54, CXCL12, and TNFSF14/LIGHT were significantly associated with worse survival in patients who received mFFX (p = 0.01). There were no immunomodulatory genes associated with survival in the Gem-based cohort.

Discussion

Our evidence implies that essential differences in the PDAC TiME exist between primary and metastatic tumors and an inflamed pretreatment TiME is associated with mFFX response. Defining components of the PDAC TiME that influence therapy response will provide opportunities for targeted therapeutic strategies that may need to be accounted for in designing personalized therapy to improve outcomes.

Implications of the Organ-Specific Immune Environment for Immune Priming Effect of Radiotherapy in Metastatic Setting

With the development of immune checkpoint inhibitors (ICIs), the tumour immune microenvironment (TIME) has been increasingly considered to improve cancer management. The TIME of metastatic lesions is strongly influenced by the underlying immune contexture of the organ in which they are located. The metastatic location itself appears to be an important prognostic factor in predicting outcomes after ICI treatment in cancer patients. Patients with liver metastases are less likely to respond to ICIs than patients with metastases in other organs, likely due to variations in the metastatic TIME. Combining additional treatment modalities is an option to overcome this resistance. Radiotherapy (RT) and ICIs have been investigated together as an option to treat various metastatic cancers. RT can induce a local and systemic immune reaction, which can promote the patient's response to ICIs. Here, we review the differential impact of the TIME according to metastatic location. We also explore how RT-induced TIME modifications could be modulated to improve outcomes of RT-ICI combinations.

Real-world clinical outcomes of the combination of anti-PD-1 antibody, trastuzumab, and chemotherapy for HER2-positive gastric/gastroesophageal junction cancer

BACKGROUND

Previous clinical trials indicated the addition of anti-PD-1 antibody remarkably improved the efficacy of trastuzumab and chemotherapy in patients with HER2-positive gastric/gastroesophageal junction (GEJ) cancer. However, no real-world experiences have been reported yet.

METHODS

We retrospectively analyzed 1212 patients with gastric/GEJ cancer treated at Nanjing Drum Tower Hospital between 2019 and 2022. Among 138 patients with HER2-positive gastric/GEJ cancer, 47 patients receiving at least two doses of the combination regimen with anti-PD-1 antibody, trastuzumab, and chemotherapy were recruited in the study population, and 38 out of 47 patients with measurable disease were included in the efficacy population. Progression-free survival (PFS), objective response rate (ORR), disease control rate (DCR), and toxicity profiles were reported.

RESULTS

In the study population, 37 (78.7%) received the study therapy as a first-line treatment. In the efficacy population, the ORR and DCR were 76.3% and 94.7%, respectively. The overall median PFS was 9.1 months (95% confidence interval [CI] 6.3-11.9 months). For the first-line treatment, the mPFS was 10 months, and 7 months for the second-line. Among 14 patients who failed the study treatment, three (21.4%) developed brain metastasis as the first failure site. No significant association was found between PFS and the expression of PD-L1. 22.2% of patients developed grade 3 treatment-related adverse events (TRAEs). No treatment-related grade ≥4 adverse events or deaths occurred.

CONCLUSION

This real-world study validated the combination regimen's high efficacy and good tolerance in patients with HER2-positive gastric/GEJ cancer. An increased incidence of brain metastasis was observed in patients who failed this regimen.

A Standardized Pathology Report for Gastric Cancer: 2nd Edition

The first edition of 'A Standardized Pathology Report for Gastric Cancer' was initiated by the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists and published 17 years ago. Since then, significant advances have been made in the pathologic diagnosis, molecular genetics, and management of gastric cancer (GC). To reflect those changes, a committee for publishing a second edition of the report was formed within the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists. This second edition consists of two parts: standard data elements and conditional data elements. The standard data elements contain the basic pathologic findings and items necessary to predict the prognosis of GC patients, and they are adequate for routine surgical pathology service. Other diagnostic and prognostic factors relevant to adjuvant therapy, including molecular biomarkers, are classified as conditional data elements to allow each pathologist to selectively choose items appropriate to the environment in their institution. We trust that the standardized pathology report will be helpful for GC diagnosis and facilitate large-scale multidisciplinary collaborative studies.

A standardized pathology report for gastric cancer: 2nd edition

The first edition of 'A Standardized Pathology Report for Gastric Cancer' was initiated by the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists and published 17 years ago. Since then, significant advances have been made in the pathologic diagnosis, molecular genetics, and management of gastric cancer (GC). To reflect those changes, a committee for publishing a second edition of the report was formed within the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists. This second edition consists of two parts: standard data elements and conditional data elements. The standard data elements contain the basic pathologic findings and items necessary to predict the prognosis of GC patients, and they are adequate for routine surgical pathology service. Other diagnostic and prognostic factors relevant to adjuvant therapy, including molecular biomarkers, are classified as conditional data elements to allow each pathologist to selectively choose items appropriate to the environment in their institution. We trust that the standardized pathology report will be helpful for GC diagnosis and facilitate large-scale multidisciplinary collaborative studies.

A novel nomogram based on the prognostic nutritional index for predicting postoperative outcomes in patients with stage I-III gastric cancer undergoing robotic radical gastrectomy

BACKGROUND

The inflammation and nutrition status are crucial factors influencing the outcome of patients with gastric cancer. This study aims to investigate the prognostic value of the preoperative prognostic nutritional index (PNI) in patients with stage I-III gastric cancer undergoing robotic radical gastrectomy combined with Enhanced Recovery after Surgery (ERAS), and further to create a clinical prognosis prediction model.

STUDY

525 patients with stage I-III gastric cancer who underwent ERAS combined with RRG from July 2010 to June 2018 were included in this work, and were divided randomly into training and validating groups in a 7-to-3 ratio. The association between PNI and overall survival (OS) was assessed by Kaplan-Meier analysis and the log-rank test. Independent risk factors impacting postoperative survival were analyzed with the Cox proportional hazards regression model. A nomogram for predicting OS was constructed based on multivariate analysis, and its predictive performance was evaluated using Harrell's concordance index (C-index), calibration plots, ROC curve, decision curve analysis (DCA), and time-dependent ROC curve analysis.

RESULTS

Survival analyses revealed the presence of a significant correlation between low preoperative PNI and shortened postoperative survival (P = 0.001). According to multivariate analysis, postoperative complications (P < 0.001), pTNM stage (II: P = 0.007; III: P < 0.001), PNI (P = 0.048) and lymph node ratio (LNR) (P = 0.003) were independent prognostic factors in patients undergoing ERAS combined with RRG. The nomogram constructed based on PNI, pTNM stage, complications, and LNR was superior to the pTNM stage model in terms of predictive performance. The C-indexes of the nomogram model were respectively 0.765 and 0.754 in the training and testing set, while AUC values for 1-year, 3-year, and 5-year OS were 0.68, 0.71, and 0.74 in the training set and 0.60, 0.67, and 0.72 in the validation set.

CONCLUSION

Preoperative PNI is an independent prognostic factor for patients with stage I-III gastric cancer undergoing ERAS combined with robotic radical gastrectomy. Based on PNI, we constructed a nomogram for predicting postoperative outcomes of gastric cancer patients, which might be utilized clinically.

Pancancer Analysis of Revealed TDO2 as a Biomarker of Prognosis and Immunotherapy

Background

Tryptophan 2,3-dioxygenase (TDO) encoded by TDO2, a rate-limiting enzyme in the kynurenine pathway, catabolizes tryptophan to kynurenine, evades immune surveillance, and promotes tumor growth. Although accumulating evidence suggests a crucial role of TDO2 during tumor formation and development, systematic evaluation of TDO2 across human cancers has rarely been reported.

Methods

To shed more light on the role of TDO2 in human cancer, we explored the expression profiles of TDO2 and identified its prognostic value in pancancer analysis through TCGA, CCLE, and GTEx databases. We further utilized TCGA data to evaluate the association between TDO2 and tumor immunological features, such as mismatch repair (MMR), tumor immune infiltration, immune checkpoint-related genes, tumor mutational burden (TMB), microsatellite instability (MSI), and DNA methyltransferase (DNMT).

Results

TDO2 exhibited different expression levels in various cancer cell lines. Frequently, TDO2 was detected to be highly expressed in the majority of cancers. In addition, high TDO2 expression was correlated with an unfavorable prognosis for patients in KIRP, LGG, TGCT, and UVM. Moreover, high TDO2 expression level positively correlated with higher immune infiltration, especially dendritic cells. Additionally, there is a close relationship between TDO2 and immune checkpoint-related gene markers, such as LAIR1, CD276, NRP1, CD80, and CD86. Finally, correlation analysis has demonstrated a high-correlation between TDO2 and TMB, MSI, MMR, and DNMT of multiple cancer types.

Conclusion

Therefore, our results suggest that TDO2 can function as a potential prognostic biomarker due to its role in tumor immunity regulation.

Tumor-derived IL-8 facilitates lymph node metastasis of gastric cancer via PD-1 up-regulation in CD8+ T cells

Background

The pretherapeutic serum interleukin-8 (sIL-8) levels have been revealed to be increased in about half of patients with locally advanced gastric cancer. However, the roles of IL-8 in lymph node metastasis (LNM) and the underlying mechanisms remain unclear.

Methods

146 patients with primary gastric carcinoma were enrolled in this study. ELISA was used to measure IL-8 levels. The CD4/CD8 ratio and programmed cell death-1 (PD-1) expression of T cells in primary tumor tissues, tumor-draining lymph nodes (TDLNs) and non-draining lymph nodes (NDLNs) were assayed with flow cytometry. Protein expression of the molecules was determined with immunohistochemistry, western blotting or immunoprecipitation. The gastric cancer mouse tumor model with LNM was utilized to determine the role of IL-8 in regulation of tumor metastasis and progression.

Results

The elevated sIL-8 levels were associated with LNM and poor prognosis in gastric cancer. Furthermore, sIL-8 was identified to be prominently produced by gastric cancer-associated fibroblasts (CAFs). Elevated IL-8 can up-regulate PD-1 expression in CD8⁺ T cells, resulting in immunosuppression in primary tumors and TDLNs, which enhances LNM of gastric cancer. Molecularly, IL-8 increases PD-1 expression through JAK2/STAT3 signaling activation, and inhibits its ubiquitination via Fbxo38 down-regulation. In addition, the in vivo studies in mouse gastric cancer model demonstrated that IL-8 promotes LNM via PD-1 up-regulation in CD8⁺ T cells.

Conclusion

The present study elucidates the pro-metastatic role of elevated IL-8 in gastric cancer, and provides novel insights to enhance immune checkpoint blockade therapy for anti-PD-1 in gastric cancer.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00262-022-03223-3.

Dissecting the Role of Immune Checkpoint Regulation Patterns in Tumor Microenvironment and Prognosis of Gastric Cancer

Many studies suggest that immune checkpoint molecules play a vital role in tumor progression and immune responses. However, the impact of the comprehensive regulation pattern of immune checkpoint molecules on immune responses, tumor microenvironment (TME) formation, and patient prognosis is poorly understood. In this study, we evaluated immune checkpoint regulation patterns in 1,174 gastric cancer (GC) samples based on 31 immune checkpoint genes (ICGs). Three distinct immune checkpoint regulation patterns with significant prognostic differences were ultimately identified. Moreover, GC patients were divided into two subgroups according to immune checkpoint score (ICscore). Patients with lower ICscore were characterized by a favorable prognosis and enhanced immune infiltration as well as an increased tumor mutation burden, non-recurrence, and microsatellite instability-high. Collectively, this study indicated that immune checkpoint regulation patterns were essential to forming the diversity of TME and a better understanding of that will contribute to assessing the characteristics of TME in GC, which intends to improve the development of immunotherapy.

Mapping the genomic diaspora of gastric cancer

Gastric cancer (GC) is a leading contributor to global cancer incidence and mortality. Pioneering genomic studies, focusing largely on primary GCs, revealed driver alterations in genes such as ERBB2, FGFR2, TP53 and ARID1A as well as multiple molecular subtypes. However, clinical efforts targeting these alterations have produced variable results, hampered by complex co-alteration patterns in molecular profiles and intra-patient genomic heterogeneity. In this Review, we highlight foundational and translational advances in dissecting the genomic cartography of GC, including non-coding variants, epigenomic aberrations and transcriptomic alterations, and describe how these alterations interplay with environmental influences, germline factors and the tumour microenvironment. Mapping of these alterations over the GC life cycle in normal gastric tissues, metaplasia, primary carcinoma and distant metastasis will improve our understanding of biological mechanisms driving GC development and promoting cancer hallmarks. On the translational front, integrative genomic approaches are identifying diverse mechanisms of GC therapy resistance and emerging preclinical targets, enabled by technologies such as single-cell sequencing and liquid biopsies. Validating these insights will require specifically designed GC cohorts, converging multi-modal genomic data with longitudinal data on therapeutic challenges and patient outcomes. Genomic findings from these studies will facilitate 'next-generation' clinical initiatives in GC precision oncology and prevention.

Heterogeneity and evolution of tumour immune microenvironment in metastatic gastroesophageal adenocarcinoma

BACKGROUND

Tumour immune microenvironment heterogeneity is prevalent in numerous cancers and can negatively impact immunotherapy response. Immune heterogeneity and evolution in gastroesophageal adenocarcinoma (GEA) have not been studied in the past.

METHODS

Together with a multi-region sampling of normal, primary and metastatic tissues, we performed whole exome sequencing, TCR sequencing as well as immune cell infiltration estimation through deconvolution of gene expression signals.

RESULTS

We discovered high TCR repertoire and immune cell infiltration heterogeneity among metastatic sites, while they were homogeneous among primary and normal samples. Metastatic sites shared high levels of abundant TCR clonotypes with blood, indicating immune surveillance via blood. Metastatic sites also had low levels of tumour-eliminating immune cells and were undergoing heavy immunomodulation compared to normal and primary tumour tissues. There was co-evolution of neo-antigen and TCR repertoire, but only in patients with late diverging mutational evolution. Co-evolution of TCR repertoire and immune cell infiltration was seen in all except one patient.

CONCLUSIONS

Our findings revealed immune heterogeneity and co-evolution in GEA, which may inform immunotherapy decision-making.

Tumor-infiltrating CD8+ T cell antitumor efficacy and exhaustion: molecular insights

Host immunity has an essential role in the clinical management of cancers. Therefore, it is advantageous to choose therapies that can promote tumor cell death and concurrently boost host immunity. The dynamic tumor microenvironment (TME) determines whether an antineoplastic drug will elicit favorable or disparaging immune responses from tumor-infiltrating lymphocytes (TILs). CD8+ T cells are one of the primary tumor-infiltrating immune cells that deliver antitumor responses. Here, we review the influence of various factors in the TME on CD8+ T cell exhaustion and survival, and possible strategies for restoring CD8+ T cell effector function through immunotherapy.

Heterogeneity of Response and Immune System Activity during Treatment with Nivolumab in Hepatocellular Carcinoma: Results from a Single-Institution Retrospective Analysis

Simple Summary

Immunotherapy is an emerging treatment in hepatocellular carcinoma, both alone and in combination. The advent of this new approach raises challenges for the interpretation of response assessment due to the peculiar patterns of mixed responses, pseudoprogression and hyperprogression. Furthermore, there are no criteria to drive selection of treatment strategy. We analyzed data from the first 10 patients treated with nivolumab in our institution and we identified different patterns of response according to the lesion’s site. Furthermore, we analyzed blood samples from the first four patients, and found differences, between a patient with shorter survival and the other three, that may provide insight into mechanisms underlying the different activities of nivolumab. Although we analyzed data from a small number of patients, our results can help to understand mechanisms of immunotherapy activity in order to define the most appropriate treatment strategy for each patient.

Abstract

Treatment of hepatocellular carcinoma (HCC) is rapidly evolving, with many new therapeutic options; in particular, immunotherapy (IT) is acquiring a major role, even in combination regimens. Despite these promising results, an important limitation is the lack of prognostic and predictive factors that prevent provision of a tool for patient stratification in order to select the most appropriate strategy. Furthermore, response assessment can be challenging with IT due to peculiar patterns such as mixed responses or pseudoprogression. We analyzed biological and clinical features from the first 10 HCC patients treated with nivolumab in our institution. Analysis of patterns of response in CT assessment revealed complete response in pulmonary lesions, along with heterogeneous behavior in the liver and other organ lesions. Peripheral blood mononuclear cells (PBMC) analysis in the first four patients showed unique alterations in a patient with poor prognosis, both at baseline (lower percentage of effector T cells, higher percentage of natural killer T [NK/T] cells) and during treatment with nivolumab (decrease in nonclassical monocytes, increase in monocytic myeloid-derived suppressor cells [MO-MDSC]), suggesting a possible prognostic role for these features. Although obtained in a small cohort of patients, our results open a new perspective for understanding mechanisms underlying IT outcomes in HCC patients.