Expression of costimulatory molecules B7-H1, B7-H4 and Foxp3+ Tregs in gastric cancer and its clinical significance

State-of-the-Art Advancements in Gastroesophageal Cancer Treatment: Harnessing Biomarkers for Precision Care

Gastroesophageal cancers (GECs) represent a significant clinical challenge. For early resectable GEC, the integration of immune checkpoint inhibitors into the perioperative chemotherapy and chemoradiation treatment paradigms are being explored and showing promising results. Frontline management of metastatic GEC is exploring the role of targeted therapies beyond PD-1 inhibitors, including anti-human epidermal growth factor receptor 2 agents, Claudin 18.2 inhibitors, and FGFR2 inhibitors, which have shown considerable efficacy in recent trials. Looking ahead, ongoing trials and emerging technologies such as bispecific antibodies, antibody-drug conjugates, and adoptive cell therapies like chimeric antigen receptor T cells are expected to define the future of GEC management. These advancements signify a paradigm shift toward personalized and immunotherapy-based approaches, offering the potential for improved outcomes and reduced toxicity for patients with GEC.

Prognostic Value of B7H4 Expression in Patients with Solid Cancers: A Systematic Review and Meta-Analysis

V-set domain-containing T-cell activation inhibitor 1 (aliases VTCN1, B7H4) participates in tumour immune escape by delivering inhibitory signals to T cells. The purpose of this article was to assess the B7H4 prognostic value in solid cancers. Three databases were searched for relevant articles. The main endpoints were overall survival (OS), disease-specific survival (DSS), progression-free survival (PFS), recurrence-free survival (RFS), and disease-free survival (DFS). Appropriate hazard ratios (HRs) were pooled. The R studio software (version 4.0.3) was used for data analysis. Thirty-one studies met the inclusion criteria. High expression of B7H4 was associated with worse OS (HR = 1.52, 95% CI: 1.37-1.68) but not with DSS (HR = 1.14, 95% CI: 0.49-2.63), RFS (HR = 1.77, 95% CI: 0.75-4.18), DFS (HR = 1.29, 95% CI: 0.8-2.09), or PFS (HR = 1.71, 95% CI: 0.91-3.2) in patients with solid cancers. High expression of B7H4 is associated with a poorer prognosis in patients with solid cancers. B7H4 is a promising prognostic biomarker and immunotherapeutic target for various solid cancers because of its activity in cancer immunity and tumourigenesis.

Integrated analysis of single-cell and bulk RNA-sequencing reveals a novel signature based on NK cell marker genes to predict prognosis and immunotherapy response in gastric cancer

Natural killer (NK) cells play essential roles in the tumor development, diagnosis, and prognosis of tumors. In this study, we aimed to establish a reliable signature based on marker genes in NK cells, thus providing a new perspective for assessing immunotherapy and the prognosis of patients with gastric cancer (GC). We analyzed a total of 1560 samples retrieved from the public database. We performed a comprehensive analysis of single-cell RNA-sequencing (scRNA-seq) data of gastric cancer and identified 377 marker genes for NK cells. By performing Cox regression analysis, we established a 12-gene NK cell-associated signature (NKCAS) for the Cancer Genome Atlas (TCGA) cohort, that assigned GC patients into a low-risk group (LRG) or a high-risk group (HRG). In the TCGA cohort, the areas under curve (AUC) value were 0.73, 0.81, and 0.80 at 1, 3, and 5 years. External validation of the predictive ability for the signature was then validated in the Gene Expression Omnibus (GEO) cohorts (GSE84437). The expression levels of signature genes were measured and validated in GC cell lines by real-time PCR. Moreover, NKCAS was identified as an independent prognostic factor by multivariate analysis. We combined this with a variety of clinicopathological characteristics (age, M stage, and tumor grade) to construct a nomogram to predict the survival outcomes of patients. Moreover, the LRG showed higher immune cell infiltration, especially CD8+ T cells and NK cells. The risk score was negatively associated with inflammatory activities. Importantly, analysis of the independent immunotherapy cohort showed that the LRG had a better prognosis and immunotherapy response when compared with the HRG. The identification of NK cell marker genes in this study suggests potential therapeutic targets. Additionally, the developed predictive signatures and nomograms may aid in the clinical management of GC.

Neoadjuvant atezolizumab plus chemotherapy in gastric and gastroesophageal junction adenocarcinoma: the phase 2 PANDA trial

Gastric and gastroesophageal junction (G/GEJ) cancers carry a poor prognosis, and despite recent advancements, most patients die of their disease. Although immune checkpoint blockade became part of the standard-of-care for patients with metastatic G/GEJ cancers, its efficacy and impact on the tumor microenvironment (TME) in early disease remain largely unknown. We hypothesized higher efficacy of neoadjuvant immunotherapy plus chemotherapy in patients with nonmetastatic G/GEJ cancer. In the phase 2 PANDA trial, patients with previously untreated resectable G/GEJ tumors (n = 21) received neoadjuvant treatment with one cycle of atezolizumab monotherapy followed by four cycles of atezolizumab plus docetaxel, oxaliplatin and capecitabine. Treatment was well tolerated. There were grade 3 immune-related adverse events in two of 20 patients (10%) but no grade 4 or 5 immune-related adverse events, and all patients underwent resection without treatment-related delays, meeting the primary endpoint of safety and feasibility. Tissue was obtained at multiple time points, allowing analysis of the effects of single-agent anti-programmed cell death ligand 1 (PD-L1) and the subsequent combination with chemotherapy on the TME. Twenty of 21 patients underwent surgery and were evaluable for secondary pathologic response and survival endpoints, and 19 were evaluable for exploratory translational analyses. A major pathologic response (≤10% residual viable tumor) was observed in 14 of 20 (70%, 95% confidence interval 46-88%) patients, including 9 (45%, 95% confidence interval 23-68%) pathologic complete responses. At a median follow-up of 47 months, 13 of 14 responders were alive and disease-free, and five of six nonresponders had died as a result of recurrence. Notably, baseline anti-programmed cell death protein 1 (PD-1)+CD8+ T cell infiltration was significantly higher in responders versus nonresponders, and comparison of TME alterations following anti-PD-L1 monotherapy versus the subsequent combination with chemotherapy showed an increased immune activation on single-agent PD-1/L1 axis blockade. On the basis of these data, monotherapy anti-PD-L1 before its combination with chemotherapy warrants further exploration and validation in a larger cohort of patients with nonmetastatic G/GEJ cancer. ClinicalTrials.gov registration: NCT03448835 .

Prognostic role and clinical significance of tumor-infiltrating lymphocyte (TIL) and programmed death ligand 1 (PD-L1) expression in gastric cancer: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

This study intended to evaluate the prognostic effects of programmed death-ligand 1 (PD-L1) and tumor-infiltrating lymphocytes (TILs) in survival and their associations with clinicopathological characteristics in patients with gastric cancer.

METHODS

PubMed, Scopus, ProQuest, Web of Science, and Ovid databases were searched to obtain the relevant studies. Eleven studies with 2298 patients were included in this study.

RESULTS

Like the level of TILs, there were no significant associations between PD-L1 expression and TNM stage, lymph node metastasis, vascular invasion, and tumor location (All p values ≥ 0.05). Furthermore, there was no significant association between PD-L1 expression with overall survival (OS) (HR = 0.76, 95% CI: 0.55 to 1.05, p value = 0.10) and disease-free survival (DFS) (HR = 0.62, 95% CI: 0.10 to 3.68, p value = 0.59). In the assessment of TILs presence and survival association, the analysis showed no association between TILs presence and overall survival (OS) (HR = 0.95, 95% CI: 0.62 to 1.45).

CONCLUSIONS

In conclusion, the study has revealed no prognostic effect of PD-L1 and TILs in gastric cancer patients.

PD-L1 Biomolecules Associated with Clinical Features in Non-Melanoma Skin Cancer

Background

Increasing evidence has indicated that several B7 family members play critical roles in the progress of many cancers. However, the clinical significance of the B7 family in cutaneous squamous cell carcinoma (cSCC) is still elusive. The purpose of this study is to investigate the potential role of B7-H1 biomolecules (PD-L1) in regulating the tumorigenesis and progression of cSCC, the most common non-melanoma skin cancer.

Methods

We collected transcriptome data of cSCC patients from TCGA databases (n = 496) and subjected the transcription data to bioinformatical analysis. Differential expression of B7-H1 genes with a grade-dependent pattern was identified. We collected paraffin sections of skin squamous carcinoma and analyzed by immunohistochemical staining. We further examined the PD-L1 levels of CD14+ cells in peripheral blood of each cSCC patient and normal subjects by flow cytometry.

Results

It was found that higher expression of PD-L1 was associated with poor prognosis of cSCC patients and shorter overall survival. These observations were further verified in the clinical paraffin sections and in peripheral blood T cells.

Conclusion

Our study reveals that PD-L1 is a potential prognostic marker in clinical prognosis for cSCC patients and could be valuable for cSCC treatment.

Revisiting Inhibition Effects of miR-28 as a Metastasis Suppressor in Gastrointestinal Cancers

MicroRNAs are critical epigenetic regulators that can be used as diagnostic, prognostic, and therapeutic biomarkers for the treatment of various diseases, including gastrointestinal cancers, among a variety of cellular and molecular biomarkers. MiRNAs have also shown oncogenic or tumor suppressor roles in tumor tissue and other cell types. Studies showed that the dysregulation of miR-28 is involved in cell growth and metastasis of gastrointestinal cancers. MiR-28 plays a key role in controlling the physiological processes of cancer cells including growth and proliferation, migration, invasion, apoptosis, and metastasis. Therefore, miR-28 expression patterns can be used to distinguish patient subgroups. Based on the previous studies, miR-28 expression can be a suitable biomarker to detect tumor size and predict histological grade metastasis. In this review, we summarize the inhibitory effects of miR-28 as a metastasis suppressor in gastrointestinal cancers. miR-28 plays a role as a tumor suppressor in gastrointestinal cancers by regulating cancer cell growth, cell differentiation, angiogenesis, and metastasis. As a result, using it as a prognostic, diagnostic, and therapeutic biomarker in the treatment of gastrointestinal cancers can be a way to solve the problems in this field.

PD-L1 expression and CD8 positive lymphocytes in human neoplasms: A tissue microarray study on 11,838 tumor samples

BACKGROUND

Programmed death ligand 1 (PD-L1) is the target of immune checkpoint inhibitor therapies in a growing number of tumor types, but a unanimous picture on PD-L1 expression across cancer types is lacking.

MATERIALS AND METHODS

We analyzed immunohistochemical PD-L1 expression in 11,838 samples from 118 human tumor types and its relationship with tumor infiltrating CD8 positive lymphocytes.

RESULTS

At a cut-off level of 10% positive tumor cells, PD-L1 positivity was seen in 85 of 118 (72%) tumor types, including thymoma (100% positive), Hodgkin's lymphoma (93%), anaplastic thyroid carcinoma (76%), Kaposi sarcoma (71%), sarcomatoid urothelial carcinoma (71%), and squamous cell carcinoma of the penis (67%), cervix (65%), floor of the mouth (61%), the lung (53%), and pharynx (50%). In immune cells, PD-L1 positivity was detectable in 103 (87%) tumor types, including tumors of haematopoetic and lymphoid tissues (75% to 100%), Warthin tumors of the parotid glands (95%) and Merkel cell carcinoma (82%). PD-L1 positivity in tumor cells was significantly correlated with the number of intratumoral CD8 positive lymphocytes across all tumor types as well as in individual tumor types, including serous carcinoma of the ovary, invasive breast carcinoma of no special type, intestinal gastric adenocarcinoma, and liposarcoma (p< 0.0001 each).

CONCLUSIONS

PD-L1 expression in tumor and inflammatory cells is found in a wide range of human tumor types. Higher rates of tumor infiltrating CD8 positive lymphocytes in PD-L1 positive than in PD-L1 negative cancers suggest that the antitumor immune response may trigger tumoral PD-L1 expression.

Inflammation-Regulated Nanodrug Sensitizes Hepatocellular Carcinoma to Checkpoint Blockade Therapy by Reprogramming the Tumor Microenvironment

Immune checkpoint blockade (ICB) utilizing programmed death ligand-1 (PD-L1) antibody is a promising treatment strategy in solid tumors. However, in fact, more than half of hepatocellular carcinoma (HCC) patients are unresponsive to PD-L1-based ICB treatment due to multiple immune evasion mechanisms such as the hyperactivation of inflammation pathway, excessive tumor-associated macrophages (TAMs) infiltration, and insufficient infiltration of T cells. Herein, an inflammation-regulated nanodrug was designed to codeliver NF-κB inhibitor curcumin and PD-L1 antibody to reprogram the tumor microenvironment (TME) and activate antitumor immunity. The nanodrug accumulated in TME by an enhanced permeability and retention effect, where it left antibody to block PD-L1 on the membrane of tumor cells and TAMs due to pH-responsiveness. Simultaneously, a new curcumin-encapsulated nanodrug was generated, which was easily absorbed by either tumor cells or TAMs to inhibit the nuclear factor kappa-B (NF-κB) signal and related immunosuppressive genes. The inflammation-regulated nanodrug possessed good biocompatibility. Simultaneously, it reprogrammed TME effectively and exhibited an effective anticancer effect in immunocompetent mice. Overall, this study provided a potent strategy to improve the efficiency of ICB-based treatment for HCC.

Prognostic Value of Programmed Death Ligand-1 Expression in Solid Tumors Irrespective of Immunotherapy Exposure: A Systematic Review and Meta-Analysis

BACKGROUND

The programmed cell death-1/programmed cell death ligand-1 (PD-L1) pathway, which plays a crucial role in cancer immune surveillance, is the target of several approved immunotherapeutic agents and is used as a predictive biomarker in some solid tumors. However, its use as a prognostic marker (i.e., regardless of therapy used) is not established clearly with available data demonstrating inconsistent prognostic impact of PD-L1 expression in solid tumors.

METHODS

We conducted a systematic literature search of electronic databases and identified publications exploring the effect of PD-L1 expression on overall survival and/or disease-free survival. Hazard ratios were pooled in a meta-analysis using generic inverse-variance and random-effects modeling. We used the Deeks method to explore subgroup differences based on disease site, stage of disease, and method of PD-L1 quantification.

RESULTS

One hundred and eighty-six studies met the inclusion criteria. Programmed cell death ligand-1 expression was associated with worse overall survival (hazard ratio 1.33, 95% confidence interval 1.26-1.39; p < 0.001). There was significant heterogeneity between disease sites (subgroup p = 0.002) with pancreatic, hepatocellular, and genitourinary cancers associated with the highest magnitude of adverse outcomes. Programmed cell death ligand-1 was also associated with worse overall disease-free survival (hazard ratio 1.19, 95% confidence interval 1.09-1.30; p < 0.001). Stage of disease did not significantly affect the results (subgroup p = 0.52), nor did the method of quantification via immunohistochemistry or messenger RNA (subgroup p = 0.70).

CONCLUSIONS

High expression of PD-L1 is associated with worse survival in solid tumors albeit with significant heterogeneity among tumor types. The effect is consistent in early-stage and metastatic disease and is not sensitive to method of PD-L1 quantification. These data can provide additional information for the counseling of patients with cancer about prognosis.

Expression of Immune Checkpoints in Malignant Tumors: Therapy Targets and Biomarkers for the Gastric Cancer Prognosis

To increase the effectiveness of anticancer therapy based on immune checkpoint (IC) inhibition, some ICs are being investigated in addition to those used in clinic. We reviewed data on the relationship between PD-L1, B7-H3, B7-H4, IDO1, Galectin-3 and -9, CEACAM1, CD155, Siglec-15 and ADAM17 expression with cancer development in complex with the results of clinical trials on their inhibition. Increased expression of the most studied ICs—PD-L1, B7-H3, and B7-H4—is associated with poor survival; their inhibition is clinically significant. Expression of IDO1, CD155, and ADAM17 is also associated with poor survival, including gastric cancer (GC). The available data indicate that CD155 and ADAM17 are promising targets for immune therapy. However, the clinical trials of anti-IDO1 antibodies have been unsatisfactory. Expression of Galectin-3 and -9, CEACAM1 and Siglec-15 demonstrates a contradictory relationship with patient survival. The lack of satisfactory results of these IC inhibitor clinical trials additionally indicates the complex nature of their functioning. In conclusion, in many cases it is important to analyze the expression of other participants of the immune response besides target IC. The PD-L1, B7-H3, B7-H4, IDO1 and ADAM17 may be considered as candidates for prognosis markers for GC patient survival.

The Positive and Negative Immunoregulatory Role of B7 Family: Promising Novel Targets in Gastric Cancer Treatment

Gastric cancer (GC), with a heterogeneous nature, is the third leading cause of death worldwide. Over the past few decades, stable reductions in the incidence of GC have been observed. However, due to the poor response to common treatments and late diagnosis, this cancer is still considered one of the lethal cancers. Emerging methods such as immunotherapy with immune checkpoint inhibitors (ICIs) have transformed the landscape of treatment for GC patients. There are presently eleven known members of the B7 family as immune checkpoint molecules: B7-1 (CD80), B7-2 (CD86), B7-H1 (PD-L1, CD274), B7-DC (PDCD1LG2, PD-L2, CD273), B7-H2 (B7RP1, ICOS-L, CD275), B7-H3 (CD276), B7-H4 (B7x, B7S1, Vtcn1), B7-H5 (VISTA, Gi24, DD1α, Dies1 SISP1), B7-H6 (NCR3LG1), B7-H7 (HHLA2), and Ig-like domain-containing receptor 2 (ILDR2). Interaction of the B7 family of immune-regulatory ligands with the corresponding receptors resulted in the induction and inhibition of T cell responses by sending co-stimulatory and co-inhibitory signals, respectively. Manipulation of the signals provided by the B7 family has significant potential in the management of GC.

A costimulatory molecule-related signature in regard to evaluation of prognosis and immune features for clear cell renal cell carcinoma

Costimulatory molecules have been proven to enhance antitumor immune responses, but their roles in clear cell renal cell carcinoma (ccRCC) remain unexplored. In this study, we aimed to explore the gene expression profiles of costimulatory molecule genes in ccRCC and construct a prognostic signature to improve treatment decision-making and clinical outcomes. We performed the first comprehensive analysis of costimulatory molecules in patients with ccRCC and identified 13 costimulatory molecule genes with prognostic values and diagnostic values. Consensus clustering analysis based on these 13 costimulatory molecular genes showed different distribution patterns and prognostic differences for the two clusters identified. Then, a costimulatory molecule-related signature was constructed based on these 13 costimulatory molecular genes, and validated in an external dataset, showing good performance for predicting a patient’s prognosis. The signature was an independent risk factor for ccRCC patients and was significantly correlated with patients’ clinical factors, which could be used as a complement for clinical factors. In addition, the signature was associated with the tumor immune microenvironment and the response to immunotherapy. Patients identified as high-risk based on our signature exhibited a high mutation frequency, a high level of immune cell infiltration, and an immunosuppressive microenvironment. High-risk patients tended to have high cytolytic activity scores and immunophenoscore of CTLA4 and PD1/PD-L1/PD-L2 blocker than low-risk patients, suggesting these patients may be more suitable for immunotherapy. Therefore, our signature could provide clinicians with prognosis predictions and help guide treatment for ccRCC patients.

Identification of a Costimulatory Molecule-Related Signature for Predicting Prognostic Risk in Prostate Cancer

Costimulatory molecules have been proven to enhance antitumor immune responses, but their roles in prostate cancer (PCa) remain unexplored. In this study, we aimed to explore the gene expression profiles of costimulatory molecule genes in PCa and construct a prognostic signature to improve treatment decision making and clinical outcomes. Five prognosis-related costimulatory molecule genes (RELT, TNFRSF25, EDA2R, TNFSF18, and TNFSF10) were identified, and a prognostic signature was constructed based on these five genes. This signature was an independent prognostic factor according to multivariate Cox regression analysis; it could stratify PCa patients into two subgroups with different prognoses and was highly associated with clinical features. The prognostic significance of the signature was well validated in four different independent external datasets. Moreover, patients identified as high risk based on our prognostic signature exhibited a high mutation frequency, a high level of immune cell infiltration and an immunosuppressive microenvironment. Therefore, our signature could provide clinicians with prognosis predictions and help guide treatment for PCa patients.

Effect of intraoperative blood transfusion on Treg and FOXP3 in patients with digestive tract malignancies and different ABO blood types

Background

Blood transfusion can cause immunosuppression and lead to worse outcomes in patients with digestive tract malignancies; however, the specific mechanism behind this is not completely understood. One theory is that increased numbers of regulatory CD3⁺CD4⁺CD25⁺FOXP3⁺ T cells (Tregs) and forkhead box protein-3 mRNA (FOXP3) expression in the blood after transfusion contribute to these outcomes. The effect of blood transfusion on immune function in patients with different ABO blood types is variable. This study investigates the effect of intraoperative blood transfusion on the number of Tregs and the expression of FOXP3 in the blood of patients with different ABO blood types and digestive tract malignancies.

Methods

Patients with digestive tract malignancies who underwent radical resection and received intraoperative blood transfusion were divided into four groups according to their blood types:blood group A, blood group B, blood group O and blood group AB (n = 20 for each group). Blood was collected from all patients before surgery, immediately after transfusion, 1 day after transfusion, and 5 days after transfusion. The number of Tregs was measured by flow cytometry. The expression of FOXP3 was detected by real time reverse transcription polymerase chain reaction (RT-PCR).

Results

There was no significant difference in the number of Tregs or expression of FOXP3 mRNA among patients with different blood types before surgery. However, the number of Tregs and the expression of FOXP3 increased after blood transfusion in all blood type groups. This increase was especially evident and statistically significant on the first day after blood transfusion when compared with measures obtained before the surgery. Measures returned to the preoperative level five days after surgery. There were significant differences in the increase of Tregs and expression of FOXP3 among patients with different blood types. The greatest increase was seen in patients with blood group B and the least in blood group A.

Conclusions

Intraoperative blood transfusion can lead to an increase in blood Tregs and FOXP3 expression in patients with digestive tract malignancies. Increases were greatest on the first day after surgery and differed among patients with different blood types. Increases were greatest in blood type B and least in blood type A.

Granulocyte-Macrophage Colony-Stimulating Factor-Activated Neutrophils Express B7-H4 That Correlates with Gastric Cancer Progression and Poor Patient Survival

Neutrophils are prominent components of gastric cancer (GC) tumors and exhibit distinct phenotypes in GC environment. However, the phenotype, regulation, and clinical relevance of neutrophils in human GC are presently unknown. Here, immunohistochemistry, real-time PCR, and flow cytometry analyses were performed to examine levels and phenotype of neutrophils in samples from 41 patients with GC, and also isolated, stimulated, and/or cultured neutrophils for in vitro regulation assays. Finally, we performed Kaplan-Meier plots for overall survival by using the log-rank test to evaluate the clinical relevance of neutrophils and their subsets. In our study, neutrophils in tumor tissues were significantly higher than those in nontumor tissues and were positively associated with tumor progression but negatively correlated with GC patient survival. Most intratumoral neutrophils showed an activated CD54⁺ phenotype and expressed high-level immunosuppressive molecule B7-H4. Tumor tissue culture supernatants from GC patients induced neutrophils to express CD54 and B7-H4 in both time-dependent and dose-dependent manners. Locally enriched CD54⁺ neutrophils and B7-H4⁺ neutrophils positively correlated with increased granulocyte-macrophage colony-stimulating factor (GM-CSF) detection ex vivo, and in vitro GM-CSF induced the expression of CD54 and B7-H4 on neutrophils in a time-dependent and dose-dependent manner. Moreover, GC tumor-derived GM-CSF activated neutrophils and induced neutrophil B7-H4 expression via Janus kinase (JAK)-signal transducer and activator of transcription 3 (STAT3) signaling pathway activation. Furthermore, higher intratumoral B7-H4⁺ neutrophil percentage/number was found in GC patients with advanced tumor node metastasis stage and reduced overall survival following surgery. Our results illuminate a novel regulating mechanism of B7-H4 expression on tumor-activated neutrophils in GC, suggesting that functional inhibition of these novel GM-CSF-B7-H4 pathways may be a suitable therapeutic strategy to treat the immune tolerance feature of GC.

Clinicopathological and prognostic significance of programmed death ligant-1 expression in gastric cancer: a meta-analysis

Background

Gastric cancer (GC) is a common malignant tumor with a high incidence in China. The use of immune checkpoint inhibitors has become the focus of tumor immunotherapy in recent years. This study was to investigate the clinicopathological and prognostic significance of programmed death ligant-1 (PD-L1) expression in GC.

Methods

We searched the PubMed, ScienceNet, EMbase, CNKI, and Wanfang databases for retrospective cohort studies on the clinicopathology and prognosis of PD-L1 expression in GC published between January 2010 and April 2020. The literature was first selected to extract data according to the inclusion and exclusion criteria, then a meta-analysis performed using Stata15.0 software. Publication bias and sensitivity analysis were carried out for the included studies.

Results

A total of 3,218 patients in 15 studies were included in the meta-analysis. The positive expression of PD-L1 was related to a decrease in the 3-year survival rate (HR =1.32, 95% CI: 1.02-1.49, P=0.028) and 5-year survival rate (HR =1.39, 95% CI: 1.14-1.69, P=0.001). The difference in PD-L1 expression was related to lymph node metastasis (OR =1.73, 95% CI: 1.18-2.54, P<0.001), but not to tumor stage (OR =1.28, 95% CI: 0.81-2.02, P=0.292).

Conclusions

The results show that PD-L1 is related to the prognosis of GC. Its high expression decreases the 3- and 5-year survival rates and promotes lymph node metastasis, but does not reflect tumor stage. The results may provide a theoretical basis for the choice of clinical immunotherapy in GC patients.

Anti-PD-1 antibody HX008 combined with oxaliplatin plus capecitabine for advanced gastric or esophagogastric junction cancer: a multicenter, single-arm, open-label, phase Ib trial

Anti-PD-1 monoclonal antibody is approved as an option for third-line treatment of advanced gastric and gastroesophageal junction (G/GEJ) cancer in several countries, but no anti-PD-1 monoclonal antibody treatment is yet approved for first-line treatment of advanced G/GEJ cancer. We report a phase Ib trial of HX008, a highly selective, humanized anti-programmed death-1 monoclonal antibody, plus oxaliplatin and capecitabine as first-line treatment for advanced G/GEJ cancer. Patients with previously untreated, locally advanced or metastatic G/GEJ cancer were enrolled. All patients received HX008 3 mg/kg intravenously every 3 weeks, oxaliplatin 130 mg/m² intravenously on day 1 every 3 weeks (up to 6 cycles), and capecitabine 1000 mg/m² orally twice daily for 14 days continuous dosing followed by a 7-day break. The primary end point was the incidence of adverse events and serious adverse events. In total, 35 patients were enrolled. Median follow-up was 12.7 months. Most frequent (>10%) grade ≥3 treatment-related adverse events were anemia (27.5%), neutropenia (20%), thrombocytopenia (17.1%), leukopenia (17.1%) and fatigue (17.3%). Objective response rate was 60.0% (95% confidence interval [CI] 42.1-76.1%). Disease control rate was 77.1% (95% CI 59.9-89.6). Median time to response and duration of response were 1.4 months (range 1.3-2.9) and 12.3 months (range 1.4-17.9+), respectively. Median PFS was 9.2 months (95% CI 5.4-not reached). These results demonstrated that HX008 combined with oxaliplatin plus capecitabine was well tolerated and demonstrated encouraging efficacy as first-line treatment for advanced G/GEJ cancer. This study was registered in china, register number was CTR20181270.

Clinicopathological significance of the immunologic signature (PDL1, FOXP3+ Tregs, TILs) in early stage triple-negative breast cancer treated with neoadjuvant chemotherapy

Patients with breast cancer are appropriate candidates for neoadjuvant chemotherapy (NAC) to facilitate conservative surgery. The chemotherapeutic agents may exert their action by inducing the anti-tumor immune response. This study aimed to evaluate the tumor immune microenvironment including PD-L1, Foxp3+ Tregs, and TILs count in early stages TNBC patients (stage T1, T2) before and after neoadjuvant chemotherapy and their correlation with the clinical and pathological response. Fifty patients of TNBC patients were enrolled in this study; all of them received neoadjuvant chemotherapy. TILs count, Foxp3+ Tregs, and PD-L1 immunohistochemical expression were investigated in all cases before NAC and then evaluated in residual masses after surgery. Data on the clinical and pathological response to NAC were collected and then statistically analyzed. PDL1 expression was detected in 24% of all studied cases, all of them were node-positive (P < 0.002); while Foxp3+ Tregs expressed in 50% and high TILs in 28%. Pathological complete response (pCR) was achieved in 40% of patients and was associated with high TILs expression (P < 0.02) and absence of Foxp3+ Tregs and PDL1 (P < 0.001 for each). In conclusion, Pathologic complete response to NAC was associated with the immunological profile of TNBC. High TILs expression with concomitant decreased PD-L1 expression and low FOXP3+ Tregs is associated with favorable tumor prognosis. Combined therapeutic approaches aiming to PD-L1 block and Tregs depletion might improve treatment efficacy in TNBC.

Distinct roles of programmed death ligand 1 alternative splicing isoforms in colorectal cancer

Although anti–programmed death‐1 (PD‐1)/programmed death ligand 1 (PD‐L1) immunotherapy has achieved great success in some cancers, most colorectal cancer (CRC) patients remain unresponsive. Therefore, further clarification of the underlying mechanisms is needed to improve the therapy. In this study, we explored the distinct functions of different PD‐L1 alternative splicing isoforms in CRC. We investigated the biological functions in PD‐L1 knocked down/knockout cells, which were verified through overexpression of PD‐L1 isoforms a, b, and c. The roles of PD‐L1 isoforms in immune surveillance resistance was also analyzed. Meanwhile, we performed RNA‐seq to screen the downstream molecules regulated by PD‐L1 isoforms. Finally, we detected PD‐L1 and PD‐L1 isoforms levels in a cohort of serum samples, two cohorts of CRC tissue samples, and analyzed the correlation of PD‐L1 isoforms with PD‐1 blockade therapy response in two clinical CRC cases. The results indicated that PD‐L1 knockout inhibited proliferation, migration, and invasion, and isoform b exerted a more significant inhibitory effect on T cells than the other two isoforms. Moreover, isoform c could promote CRC progression through regulating epithelial‐mesenchymal transition. Clinical data showed that CRC patients with positive PD‐L1 expression were associated with poorer overall survival. High serum PD‐L1 level was associated with poor prognosis. The level of isoform b or c was negatively associated with prognosis, and a higher level of isoform b was associated with a good response to anti–PD‐1 therapy. In conclusion, isoform b should be considered as a biomarker for clinical responsiveness to anti–PD‐1/PD‐L1 immunotherapy; isoform c had a prometastatic role and is a new potential target for CRC therapy.

Genes Involved in the PD-L1 Pathway Might Associate with Radiosensitivity of Patients with Gastric Cancer

The PD-1/PD-L1 pathway plays an important role in the treatment of cancers as immune checkpoint. However, the association of genes involved in the PD-L1 pathway and radiosensitivity of gastric cancer has not been fully characterized. This study aims to explore the relationship between the expression levels of genes involved in the PD-L1 pathway and radiosensitivity for gastric cancer patients. A total of 367 patients with clinical survival information and radiotherapy information were obtained in The Cancer Genome Atlas (TCGA). Genes involved in the PD-L1 pathway were categorized into high and low expression level groups according to the median value. The Cox proportional hazards model was used to find the association between gene expression level and radiosensitivity. The results show that high expression levels of CD274, EGFR, RAF1, RPS6KB1, PIK3CA, MTOR, CHUK, NFKB1, TRAF6, FOS, NFATC1, and HIF1A were associated with radiosensitivity of gastric cancer. While low expression level of HRAS was also associated with radiosensitivity in gastric cancer. The rates of a new tumor event and disease progression were lower for radiosensitivity patients than other patients. The relationship between the expression level of CD274 and other genes involved in the PD-L1 pathway is significant. GO (Gene Ontology) analysis shows that the biological process of 13 genes was mainly related to innate immune response activating the cell surface receptor signaling pathway. KEGG analysis demonstrated that 13 genes in gastric cancer are mainly related to the PD-L1 expression and PD-1 checkpoint pathway in cancer. The correlation between the expression level of CD274 and other genes involved in the PD-L1 pathway is significant. The present study offered more evidence for using PD-L1 and genes involved in the PD-L1 pathway as potential biomarkers to predict radiosensitive patients with gastric cancer.

Emerging Multimodality Approaches to Treat Localized Esophageal Cancer

Esophageal cancer has a poor prognosis, with 5-year survival rates ranging from 20% to 35% in the nonmetastatic setting. Despite advances in surgical techniques and optimization of chemoradiotherapy regimens, overall survival benefits have been incremental at best. Esophageal cancer requires a concerted multidisciplinary approach, perhaps more so than any other tumor type given the integral role played by the esophagus in maintaining calorific intake and the propensity for early spread through the lymphatics. This review describes the latest in surgical techniques to minimize postoperative complications and examines previous and ongoing systemic therapy approaches. Strategies that harness a patient's own immune system hold great promise, and shifting checkpoint inhibitors from the metastatic setting to the neoadjuvant/adjuvant setting is currently being evaluated in phase II and III clinical trials. In addition, a much better understanding of the interplay between tumors and their immune microenvironment is clearly needed to better judge how best to engage each patient's immune system, and there will be likely demonstrable differences between early-stage tumors and metastatic disease. This review highlights emerging data, which demonstrate that, in addition to The Cancer Genome Atlas classification of esophageal squamous cell carcinoma having a distinct molecular makeup compared with esophageal adenocarcinoma, there are also differing responses to PD-1 inhibitors. Histology and the underlying immune milieu may have important ramifications for the management of localized disease in the future, above and beyond PD-L1 expression, microsatellite instability status, and tumor mutational burden.

Novel Frontiers of Treatment for Advanced Gastric or Gastroesophageal Junction Cancer (GC/GEJC): Will Immunotherapy Be a Future Direction?

Considering the limited progress of chemotherapy and targeted therapy in improving the generally disappointing outcomes of advanced gastric or gastroesophageal junction cancer (GC/GEJC), immunotherapies have been gradually developed and advanced into novel frontiers of treatment for advanced GC/GEJC. Nevertheless, the response to immunotherapy was not always satisfactory, and the emergence of resistance was unavoidable. These factors prompt the development of different combination therapies and predictive and prognostic biomarkers of efficacy to improve the outcomes of patients with advanced GC/GEJC and to overcome drug resistance. This article discusses the advances of immune monotherapy, multiple current and ongoing clinical trials of immune combination therapy, immune-related adverse events, and various biomarkers in GC/GEJC.

Prognostic impacts of the combined positive score and the tumor proportion score for programmed death ligand-1 expression by double immunohistochemical staining in patients with advanced gastric cancer

BACKGROUND

The tumor proportion score (TPS) and combined positive score (CPS) have been developed to assess programmed death ligand 1 (PD-L1) expression in gastric cancer (GC). This study aimed to elucidate the role of TPS and CPS as prognostic biomarkers.

METHODS

A total of 191 patients with GC who received curative gastrectomy were retrospectively enrolled. Double immunohistochemistry of PD-L1 and ionized calcium binding adaptor molecule 1 was performed to clearly distinguish PD-L1 expression between tumor cells and macrophages. Survival analysis for PD-L1 expression by TPS and CPS was performed.

RESULTS

PD-L1 positivity was detected in 39 patients (20.4%) by TPS and in 137 patients (71.7%) by CPS. Patients with PD-L1 positivity by CPS experienced significantly shorter overall survival (OS) (P < 0.01) and relapse-free survival (RFS) (P = 0.01) than the other patients. In contrast, patients with either PD-L1 status by the TPS showed similar OS and RFS times. Multivariate Cox regression analysis for OS and RFS demonstrated that PD-L1 positivity by CPS was a significant independent factor for poor OS (hazard ratio [HR] 2.27, 95% confidence interval [CI] 1.27-4.37, P < 0.01) and RFS (HR 1.81, 95% CI 1.07-3.22, P = 0.03).

CONCLUSIONS

CPS was shown to be a more useful assessment method of determining PD-L1 expression than TPS as a prognostic biomarker. This suggests that the total number of PD-L1-expressing cells, including tumor and immune cells, is a more sensitive prognostic biomarker than the number of PD-L1-expressing tumor cells in GC.

Prognostic role of tumor-infiltrating lymphocytes in gastric cancer: a meta-analysis and experimental validation

INTRODUCTION

We performed a meta-analysis and an experimental validation to investigate the association between tumor infiltrating lymphocytes (TILs) and the outcome of gastric cancer (GC) patients to provide prognostic indicators for clinical practice.

MATERIAL AND METHODS

The relative literature of TILs in tumor tissue from patients with gastric cancer was searched from PubMed, Embase, NIH databases, from April 2000 to 31 December 2016. Studies on the prognostic value of TILs as CD3+, CD4+, CD8+, GrB+, and FOXP3+ lymphocytes for GC were retrieved, and also the related references were traced as supplements. Independent screening documents, extracting information and evaluating quality were implemented independently by 2 evaluators according to the inclusion and exclusion criteria, which were then analyzed by meta-analysis using STATA version 12.0 software.

RESULTS

The results indicated that high levels of intratumoral CD8+, CD3+ and CD4+ T cell infiltration were associated with better overall survival(OS) in gastric cancer patients, while high density of intratumoral FOXP3+ T cells was not closely associated with a worse outcome. Additionally, in our study, higher density of granzyme B+ (GrB+) T cell infiltration indicated an optimistic prognosis, and infiltration of a larger number of general TILs also suggested a favorable prognosis by log-rank test analysis.

CONCLUSIONS

This meta-analysis clarified that high levels of CD8+, CD3+, and CD4+ T cell infiltration in tumor tissue showed better OS in GC patients, whereas high density of FOXP3+ T cell infiltration may not be recognized as a negative prognostic factor. These results may provide some useful prognostic indicators for clinical application in gastric cancer.

Comprehensive understanding of B7 family in gastric cancer: expression profile, association with clinicopathological parameters and downstream targets

Objectives: B7 family members were identified as co-stimulators or co-inhibitors of the immune response and played important roles in cancer immunotherapy; however, their dysregulation in gastric cancer is still unclear.

Methods: Data were obtained from TCGA and GTEX database. B7 mutations, association with DNA methylation and affected proteins were analyzed in cBioportal. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis and Gene Ontology (GO) project was studied by DAVID to find the downstream signaling pathway and important metabolic process, respectively. Protein-protein interaction network was analyzed in STRING and Cytoscape. A total of 160 paired specimens in tissue microarray from patients with gastric cancer were used to detect the expression levels of seven B7 family members via immunohistochemical analysis.

Results: Bioinformatics studies revealed dysregulation of B7 members in gastric cancer. Gene and protein alteration were found in B7 family members. Furthermore, DNA methylation and gene alteration may be both involved in B7 member dysregulation in gastric cancer. Importantly, the high expression of B7-H6 is associated with good overall patient survival. B7 family members primarily affect the EGFR tyrosine kinase inhibitor resistance signaling pathway in gastric cancer and TP53 may be an important target of the family. The low expression of B7-1 and high expression of B7-H3 and B7-H7 were validated by IHC staining.

Conclusions: Our results provide insight into B7 family member expression in gastric cancer and stress their importance in stomach tumorigenesis, which may be beneficial for designing future cancer treatments.

Significant function and research progress of biomarkers in gastric cancer

Gastric cancer is one of the most common gastrointestinal tumor types, and the incidence and mortality rates are higher in men compared with women. Various studies have revealed that gastric cancer is a spectrum of tumor types, which have biological and genetic diversity. It has proven to be difficult to improve the overall survival and disease-free survival of patients with gastric cancer through the use of traditional surgery and chemoradiation, as gastric cancer is usually identified at an advanced stage. In consequence, the outcome is frequently poor. Thus, novel biomarkers and anticancer targets are required to improve the outcome. As the identification of biomarkers has increased due to advances in research and the greater availability of bioinformatics and functional genomics, the potential therapeutic regimens available have also increased concurrently. These advances have also improved the ability to predict responses to chemotherapy, targeted therapy and immunotherapy, whilst other biomarkers predict post-treatment survival and recurrence based on their expression. This review focuses closely on the important functions of biomarkers in the timely diagnosis and treatment of gastric cancer, in addition to the advances in the study of certain novel markers in gastric cancer.

B7-H4, a promising target for immunotherapy

The coinhibitory molecule B7-H4, an important member of the B7 family, is abnormally expressed in tumors, inflammation and autoimmune diseases. B7-H4 negatively regulates T cell immune response and promotes immune escape by inhibiting the proliferation, cytokine secretion, and cell cycle of T cells. Moreover, B7-H4 plays an extremely important role in tumorigenesis and tumor development including cell proliferation, invasion, metastasis, anti-apoptosis, etc. In addition, B7-H4 has the other biological functions, such as protection against type 1 diabetes (T1D) and islet cell transplantation. Therefore, B7-H4 has been identified as a novel marker or a therapeutic target for the treatment of tumors, inflammation, autoimmune diseases, and organ transplantation. Here, we summarized the expression profiles, physiological and pathological functions, and regulatory mechanisms of B7-H4, the signaling pathways involved, as well as B7-H4-based immunotherapy.

Programmed death-ligand 1 and survival in colorectal cancers: A meta-analysis

BACKGROUND

Programmed death-ligand 1 (PD-L1) is a programmed death 1 (PD-1) ligand that plays a pivotal role in the inhibition of the T-cell-mediated immune response. The expression of PD-L1 is associated with the prognosis and clinical outcomes of multiple tumors. However, the prognostic value of PD-L1 overexpression in colorectal cancer is still controversial. In this study, we sought to clarify this by presenting a meta-analysis of relevant studies.

METHODS

Databases including PubMed, Web of Science, and EMBASE were systematically searched for studies concerning the expression of PD-L1 and survival in colorectal cancer. The reported hazard ratios (HR) with 95% confidence intervals (CI) of overall survival, disease-free survival, and recurrence-free survival in the included studies were analyzed by fixed effects/random effects models.

RESULTS

Fifteen studies involving 3078 patients with colorectal cancer were included in our meta-analysis. Overexpression of PD-L1 was found to be associated with poor overall survival (HR 1.83; 95% CI 1.21, 2.79; P = 0.005) and poor recurrence-free survival (HR 2.78; 95% CI 1.43, 5.42; P = 0.003). However, no correlation was found between PD-L1 overexpression and poor disease-free survival (HR 1.23; 95% CI 0.83, 1.82; P = 0.305). Overexpression of PD-L1 indicating poor survival held true across different geographical areas, sample sizes, analysis types, sources of HRs, and cell types.

CONCLUSION

Overexpression of PD-L1 is associated with worse prognosis in patients with colorectal cancer and can guide physicians in the application of PD-1/PD-L1 immune checkpoint-targeted therapy.

Tumor cell expression of B7-H4 correlates with higher frequencies of tumor-infiltrating APCs and higher CXCL17 expression in human epithelial ovarian cancer

B7-H4, an immune suppressive member of the B7 family, is highly expressed in a wide variety of human malignancies making it an attractive immunotherapeutic target. However, the association between B7-H4 expression in the tumor microenvironment and the immune infiltrate has not been comprehensively examined. To evaluate the immune tumor microenvironment, we analyzed epithelial ovarian tumors from 28 patients using flow cytometry, immunohistochemistry, functional, and genomic analyses. We determined B7-H4 expression patterns and compared the immune infiltrates of tumors with high and low surface expression of B7-H4. Frequencies and phenotypes of tumor and immune cells were determined using multiple flow cytometry panels. Immunohistochemistry was used to analyze cellular infiltration and location. Publicly available datasets were interrogated to determine intratumoral cytokine and chemokine expression. We found that B7-H4 was predominantly expressed by tumor cells in the epithelial ovarian tumor microenvironment. Surface expression of B7-H4 on tumor cells was correlated with higher levels of infiltrating mature antigen-presenting cells. Further, expression of CXCL17, a monocyte and dendritic cell chemoattractant, correlated strongly with B7-H4 expression. T cells expressed activation markers, but T cells expressing a combination of markers associated with T cell activation/exhaustion phenotype were not prevalent. Overall, our data suggest that B7-H4 is associated with a pro-inflammatory tumor microenvironment.

B7x-from bench to bedside

B7x is an immune checkpoint molecule which belongs to the B7 family of ligands which includes PD-L1, PD-L2, B7-H3 and HHLA2. B7x belongs to the Immunoglobulin superfamily and its protein structure is similar to other members with a N terminus peptide, IgV and IgC like extracellular domain with four cysteine residues. Its receptor is yet to be identified. B7x inhibits T cell proliferation and expansion by IL-2 dependent and non-IL-2 dependent pathways. Even though high levels of B7x mRNA can be detected in most tissues its protein expression is highly limited suggesting significant post translational control. In vivo data, show that B7x plays an important role in limiting autoimmunity in the peripheral tissues and fine-tuning autoimmune responses. B7x is highly expressed in various cancers and in prostate cancer its expression is corelated with poorer outcomes. Local production of IL-6 and IL-10 in various cancers promotes B7x expression and tumor immune evasion. B7x is especially expressed in PD-L1 negative tumors suggesting that this may be an important method of immune evasion in these tumors. Currently drug development, targeting B7x through various mechanisms including monoclonal antibodies and antibody drug conjugates are in development in cancers and increasing B7x expression with fusion proteins in autoimmune diseases is underway.

The Importance of a Conjoint Analysis of Tumor-Associated Macrophages and Immune Checkpoints in Pancreatic Cancer

OBJECTIVES

Tumor-associated macrophages are dominant players in establishing the inmmunosuppressive microenvironment in pancreatic ductal adenocarcinoma (PDAC). Immune checkpoint inhibitor monotherapy has achieved limited clinical effectiveness. To date, the interaction of macrophages and checkpoint regulators and their correlation with clinicopathologic characteristics in PDAC have been largely unavailable.

METHODS

Macrophages and immune checkpoint expression were assessed by immunohistochemistry from 80 PDAC samples. Clinicopathologic features and the prognostic value of each marker were evaluated. In vitro changes in the expression of immune markers in cocultured macrophages and PDAC cells were detected by Western blot and immunosorbance assays.

RESULTS

The macrophages marker CD163 and the checkpoint marker programmed death-ligand 1 (PD-L1) remained as the independent prognostic factors for overall survival (hazard ratio, 2.543; P = 0.017 and hazard ratio, 2.389; P = 0.021). Furthermore, integrated analysis of CD163 and PD-L1 served as more optimal indicators of survival (P = 0.000). In vitro coculture of macrophages and PDAC cells significantly increased the expression of CD163 and PD-L1, compared with monocultured counterpart (P < 0.05).

CONCLUSIONS

Combined analysis of CD163 and PD-L1 was enhanced indicators of survival in PDAC patients. The interaction of macrophages and immune checkpoints implied the value of the combination therapy.

The emerging role of immunotherapy for esophageal cancer

PURPOSE OF REVIEW

The management of esophageal cancer has not changed significantly over the last decade. Survival rates remain poor in locally advanced and metastatic disease. Newer treatment modalities are desperately needed if we are to improve 5-year overall survival rates. Immunotherapeutic strategies hold great promise, but a much greater understanding of the immune microenvironment underlying squamous cell and esophageal adenocarcinoma is needed if we are to exploit the inherent cancer fighting capabilities of each patient's immune system.

RECENT FINDINGS

Here we describe current and future predictive biomarkers, provide a synopsis of the most significant trial results to date, and explain pivotal ongoing phase III trials.

SUMMARY

Recent findings suggest that esophageal squamous cell carcinoma may be more sensitive to single agent PD-1 inhibition than esophageal adenocarcinoma, and selecting patients according to PD-L1 combined positive score (CPS) of at least 10 or more may predict higher response rate. We await data indicating the optimal immuno-oncology (IO-IO) combinations that will allow more patients to respond, however it is likely that personalized immunotherapy may be required for the majority. At the present time, it is hoped that chemotherapy combined with PD-1 inhibition will be an optimal strategy, but we await confirmation from soon-to-be published phase III trials.

Forkhead box P3 gene silencing inhibits the expression of chemokines and chemokine receptors associated with cell growth, migration, and apoptosis in hepatocellular carcinoma cells

The aberrant expression of forkhead box P3 (FOXP3) leads to the formation of malignant tumors. FOXP3 expression levels are also elevated in hepatocellular carcinoma (HCC). The aim of the present study was to investigate the effects of FOXP3 silencing on cell proliferation, migration, apoptosis and chemokine/chemokine receptor expression in the MHCC-97H HCC cell line. Three FOXP3 short hairpin (sh)RNA constructs were designed: Sh-FOXP3-1-pGreenPuro, sh-FOXP3-2-pGreenPuro, and sh-FOXP3-3-pGreenPuro. MHCC-97H cells were transfected with shRNA-FOXP3, and the mRNA and protein expression levels of C-X-C motif chemokine (CXC) ligand 12 (CXCL12), CXCL11, CXC receptor 4 (CXCR4) and CXCR7 were measured. Cell Counting Kit-8, terminal deoxynucleotidyl-transferase-mediated dUTP nick end labeling and Transwell assays were used to evaluate cell proliferation, apoptosis and migration, respectively. Of the three FOXP3 lentivirus carriers constructed, sh-FOXP3-1 significantly reduced FOXP3 expression levels and was chosen for further experiments. sh-FOXP3-1 inhibited cell proliferation, promoted apoptosis and inhibited cell migration compared with the negative control. The mRNA and protein expression levels of CXCL12, CXCL11, CXCR4 and CXCR7 were decreased significantly in response to FOXP3 silencing. FOXP3 silencing may therefore inhibit cell growth, induce apoptosis and inhibit migration in HCC cells, possibly by impairing the chemokine/chemokine receptor axes.

Recent advances in the study of regulatory T cells in gastric cancer

Gastric cancer (GC), which features a complex pathogenesis and mechanism, remains refractory. FOXP3⁺ regulatory T cells (Tregs), which have been implicated in the progression of gastric cancer, play an immunosuppressive role in the tumor microenvironment. However, the prognostic value of Treg infiltration is still controversial in GC patients. Recently, the association of Tregs with the clinicopathological characteristics of GC patients, the prognostic value of Tregs alone or its combination with other factors to GC patients, the role of Tregs in GC tumor microenvironment, clinical applications and Tregs-targeted therapies for GC patients have become hot issues. In this review, we are going to discuss these scientific researches which focused on these topics.

Regulatory T cells and M2-polarized tumour-associated macrophages are associated with the oncogenesis and progression of oral squamous cell carcinoma

Regulatory T cells (Tregs) and tumour-associated macrophages (TAMs) contribute to the tumour microenvironment by inhibiting anti-tumour immune responses. This study was performed to investigate the roles of Tregs and TAMs in oral squamous cell carcinoma (OSCC) and oral epithelial precursor lesions (OEPL). The expression of Treg markers CD25 and FoxP3 and TAM markers CD163 and CD204 was investigated in 82 OSCC and 45 OEPL specimens, and their associations with clinicopathological parameters were analyzed. Correlations were found among CD25, FoxP3, CD163, and CD204 levels (P <  0.001), and these targets were up-regulated in OSCC compared to OEPL (P <  0.001). In OSCC, infiltration of Tregs and/or M2 TAMs was associated with sex and clinicopathological features, such as tumour size, nodal metastasis, tissue differentiation, stromal reaction, invasive behaviour, and invasive depth. In OEPL, CD25, FoxP3, CD163, and CD204 immunoreactivities were significantly associated with sex, postoperative recurrence, and cancerization to OSCC. This study is novel in showing that the infiltration of Tregs and M2 TAMs is significantly associated with the progression of premalignant lesions to OSCC. This suggests that these cells represent prognostic biomarkers for premalignant lesion progression and that immunotherapeutic approaches to control Treg/M2 TAM numbers could protect against progression to malignancy.

KEYNOTE-585: Phase III study of perioperative chemotherapy with or without pembrolizumab for gastric cancer

BACKGROUND

Surgical resection is the only curative treatment option for gastric cancer. Despite widespread adoption of multimodality perioperative treatment strategies, 5-year overall survival rates remain low. In patients with advanced gastric or gastroesophageal junction adenocarcinoma, pembrolizumab has demonstrated promising efficacy and manageable safety as monotherapy in previously treated patients and as first-line therapy in combination with cisplatin and 5-fluorouracil. Combining chemotherapy with pembrolizumab in the neoadjuvant/adjuvant setting may benefit patients with locally advanced, resectable disease.

AIM

To describe the design and rationale for the global, multicenter, randomized, double-blind, Phase III KEYNOTE-585 study to evaluate the efficacy and safety of pembrolizumab plus chemotherapy compared with placebo plus chemotherapy as neoadjuvant/adjuvant treatment for localized gastric or gastroesophageal junction adenocarcinoma. ClinicalTrials.gov : NCT03221426.

Safety and efficacy of nivolumab in combination with S-1/capecitabine plus oxaliplatin in patients with previously untreated, unresectable, advanced, or recurrent gastric/gastroesophageal junction cancer: interim results of a randomized, phase II trial (ATTRACTION-4)

BACKGROUND

Nivolumab is approved as an option for third- or later-line treatment of advanced gastric/gastroesophageal junction (G/GEJ) cancer in several countries after ATTRACTION-2. To further improve the therapeutic efficacy of first-line therapy, exploration of a nivolumab-chemotherapy combination is warranted. In part 1 (phase II) of ATTRACTION-4, the safety and efficacy of nivolumab combined with S-1 plus oxaliplatin (SOX) or capecitabine plus oxaliplatin (CapeOX) as first-line therapy for unresectable advanced or recurrent human epidermal growth factor receptor 2 (HER2)-negative G/GEJ cancer were evaluated.

PATIENTS AND METHODS

Patients were randomized (1 : 1) to receive nivolumab (360 mg intravenously every 3 weeks) plus SOX (S-1, 40 mg/m2 orally twice daily for 14 days followed by 7 days off; oxaliplatin, 130 mg/m2 intravenously on day 1 every 3 weeks) or CapeOX (capecitabine, 1000 mg/m2 orally twice daily for 14 days followed by 7 days off; oxaliplatin, 130 mg/m2 intravenously on day 1 every 3 weeks) until disease progression, unacceptable toxicity, or consent withdrawal.

RESULTS

Of 40 randomized patients, 39 (nivolumab plus SOX, 21; nivolumab plus CapeOX, 18) and 38 (21 and 17, respectively) comprised the safety and efficacy populations, respectively. Most frequent (>10%) grade 3/4 treatment-related adverse events were neutropenia (14.3%) in the nivolumab plus SOX group, and neutropenia (16.7%), anemia, peripheral sensory neuropathy, decreased appetite, type 1 diabetes mellitus, and nausea (11.1% each) in the nivolumab plus CapeOX group. No treatment-related death occurred. Objective response rate was 57.1% (95% confidence interval 34.0-78.2) with nivolumab plus SOX and 76.5% (50.1-93.2) with nivolumab plus CapeOX. Median overall survival was not reached (NR) in both groups. Median progression-free survival was 9.7 months (5.8-NR) and 10.6 months (5.6-12.5), respectively.

CONCLUSION

Nivolumab combined with SOX/CapeOX was well tolerated and demonstrated encouraging efficacy for unresectable advanced or recurrent HER2-negative G/GEJ cancer. ATTRACTION-4 has proceeded to part 2 (phase III) to compare nivolumab plus SOX/CapeOX versus placebo plus SOX/CapeOX.

CLINICALTRIALS.GOV ID

NCT02746796.

Pembrolizumab alone or in combination with chemotherapy as first-line therapy for patients with advanced gastric or gastroesophageal junction adenocarcinoma: results from the phase II nonrandomized KEYNOTE-059 study

BACKGROUND

The multicohort, phase II, nonrandomized KEYNOTE-059 study evaluated pembrolizumab ± chemotherapy in advanced gastric/gastroesophageal junction cancer. Results from cohorts 2 and 3, evaluating first-line therapy, are presented.

METHODS

Patients ≥ 18 years old had previously untreated recurrent or metastatic gastric/gastroesophageal junction adenocarcinoma. Cohort 3 (monotherapy) had programmed death receptor 1 combined positive score ≥ 1. Cohort 2 (combination therapy) received pembrolizumab 200 mg on day 1, cisplatin 80 mg/m² on day 1 (up to 6 cycles), and 5-fluorouracil 800 mg/m² on days 1-5 of each 3-week cycle (or capecitabine 1000 mg/m² twice daily in Japan). Primary end points were safety (combination therapy) and objective response rate per Response Evaluation Criteria in Solid Tumors version 1.1 by central review, and safety (monotherapy).

RESULTS

In the combination therapy and monotherapy cohorts, 25 and 31 patients were enrolled; median follow-up was 13.8 months (range 1.8-24.1) and 17.5 months (range 1.7-20.7), respectively. In the combination therapy cohort, grade 3/4 treatment-related adverse events occurred in 19 patients (76.0%); none were fatal. In the monotherapy cohort, grade 3-5 treatment-related adverse events occurred in seven patients (22.6%); one death was attributed to a treatment-related adverse event (pneumonitis). The objective response rate was 60.0% [95% confidence interval (CI), 38.7-78.9] (combination therapy) and 25.8% (95% CI 11.9-44.6) (monotherapy).

CONCLUSIONS

Pembrolizumab demonstrated antitumor activity and was well tolerated as monotherapy and in combination with chemotherapy in patients with previously untreated advanced gastric/gastroesophageal junction adenocarcinoma.

CLINICAL TRIAL

ClinicalTrials.gov NCT02335411.

PD-L1 monoclonal antibody-conjugated nanoparticles enhance drug delivery level and chemotherapy efficacy in gastric cancer cells

Background

Docetaxel (DOC) is widely used as a chemotherapy drug for various tumors, including gastric cancer (GC), but the clinical application of DOC has been limited due to the hydrophobicity of the drug. We aimed to formulate a multifunctional nanoparticle (NP) system to reduce the side effects of the chemotherapy agent, to promote synergistic therapeutic effects, and to achieve targeted delivery of the therapy.

Methods

The polyethylene glycol-poly(ε-caprolactone) NPs (PEG-PCL NPs) were prepared by a ring opening copolymerization technique and were then conjugated with a programmed death-ligand 1 (PD-L1) monoclonal antibody (mAb). The effects of the surface coating on particle size, size distribution, zeta potential, drug encapsulation efficiency, loading capacity, and the drug release kinetics were investigated. By using a panel of PD-L1-expressing human GC cell lines and PD-L1-overexpressing cells, we studied cellular uptake, cytotoxic effects, and cellular apoptosis in the presence of PD-L1 mAb-conjugated NPs.

Results

The characterization of the structure and biological functions of DOC-PEG-PCL-mAb NPs was investigated in vitro. X-ray photoelectron spectroscopy validated the presence of the PD-L1 mAbs on the NP surface. The cellular uptake analysis showed that the antibody-conjugated NPs achieved significantly higher cellular uptake. The results of an in vitro cytotoxicity experiment on three GC lines further proved the targeting effects of the antibody conjugation. In addition, we found that the DOC-PEG-PCL-mAb NPs induced cell apoptosis and enhanced G2-M arrest in cancer cells, indicating the inhibition of microtubule synthesis. When compared with the control groups, DOC-PEG-PCL-mAb NPs are more effective in inhibiting PD-L1 expression in GC cells.

Conclusion

Our results reported here highlight the biological and clinical potential of DOC-PEG-PCL-mAb NPs using PD-L1 mAbs in GC treatment.

PD-L1 and immune infiltrates are differentially expressed in distinct subgroups of gastric cancer

This study investigates the association of PD-L1 expression and immune cell infiltrates and their impact on clinical outcome, in addition to their overlap with microsatellite instability (MSI), HER2 and ATM molecular subgroups of gastric cancer (GC). PD-L1 membrane expression on tumour cells (TC) and infiltrating immune cells (IC), CD3 + T-lymphocytes, CD8+ cytotoxic T-cells, ATM and HER2 were assessed by immunohistochemistry (IHC) in the ACRG (Asian Cancer Research Group) GC cohort (N = 380). EBV status was determined using in situ hybridization and MSI status was performed using PCR and MLH1 IHC. The PD-L1 segment was associated with increased T-cell infiltrates, while the MSI-high segment was enriched for PD-L1, CD3, and CD8. Multivariate analysis confirmed PD-L1 positivity, high CD3 and high CD8 as independent prognostic factors for both disease-free survival and overall survival (all p < 0.05). Patients with MSI-high tumours had better overall survival by both univariate and multivariate analysis. The ATM-low and HER2-high subgroups differed markedly in their immune profile; the ATM-low subgroups enriched for MSI, PD-L1 positivity and CD8 + T-cells, while the HER2 segment was enriched for MSS, with no enrichment for immune markers. Hence, we demonstrate a molecular profiling approach that can divide GC into four molecular subgroups, namely ATM-low, HER2-high, PD-L1 positive and MSI-high with differing levels of immune infiltrates and prognostic significance which may help to stratify patients for response to targeted therapies.

Evolving Treatment Strategies and Outcomes in Advanced Gastric Cancer with Peritoneal Metastasis

Gastric cancer (GC) has a predilection to metastasize to the peritoneum, denoting a poor prognosis. Treatment strategies available for advanced GC have significantly evolved over time and can be categorized into systemic, regional, and surgical. Although systemic therapies have been the mainstay for the treatment of advanced GC, their ability in achieving long-term survival in patients with peritoneal involvement is modest at best. This article describes advances in combined modality treatment of peritoneal metastases, specifically with an emphasis on peritoneal-directed therapies.

PD-L1 expression and the prognostic significance in gastric cancer: a retrospective comparison of three PD-L1 antibody clones (SP142, 28-8 and E1L3N)

Background

Immunohistochemistry (IHC) for programmed cell death ligand 1 (PD-L1) displays staining diversity. We compared IHC staining of PD-L1 in gastric cancer (GC) by using three commercially available antibody clones, and analyzed the correlation with the prognosis.

Methods

IHC using PD-L1 antibodies (clones SP142, 28–8 and E1L3N) in 315 formalin-fixed paraffin-embedded samples was qualitatively compared at the 1, 5 and 10% cut-off by two pathologists on total, tumor and immune/stromal cells. We used computer – assisted scoring to quantitatively analyze and compare the “H-score” of PD-L1 expression in 66 samples on total cells. The antibody clone SP142 was selected to investigate the infiltration of PD-L1⁺CD8⁺ T cells using automated quantitative immunofluorescence analyses (n = 50) and the prognostic significance. The prognoses were assessed by log-rank test.

Results

PD-L1 clones SP142 and 28–8 displayed great concordance by qualitative (κ = 0.816, 0.810 for total cells and tumor cells at the 5% cut-off) and quantitative analyses (R² = 0.7991, 0.8187 for positive percentage and “H-score”). PD-L1 clone SP142 showed the highest positivity in immune/stromal cells staining (18.41%) compared to 28–8 (7.62%), while clone E1L3N showed poor staining in both tumor and immune/stromal cells. Clone SP142, but not 28–8 and E1L3N, predicted a worse prognosis at the 5% cut-off (p = 0.0243). Both the clone SP142 and 28–8 had high inter-pathologist correlation for tumor staining (R² = 0.9805 and R² = 0.9853), but a moderate correlation for stromal/immune cell staining (R² = 0.5653 and R² = 0.5745). Furthermore, a higher density of PD-L1⁺CD8⁺ T cells was correlated with a shorter survival time (R² = 0.0909, p = 0.0352).

Conclusions

PD-L1 antibody clone SP142 was superior in cell staining, particularly in immune/stromal cell and prognosis. These findings are important for selection of PD-L1 antibody clones in the future diagnostic test.

Electronic supplementary material

The online version of this article (10.1186/s13000-018-0766-0) contains supplementary material, which is available to authorized users.

Prognostic role of tumor-infiltrating lymphocytes in gastric cancer: A systematic review and meta-analysis

BACKGROUND

The potential prognostic value of tumor-infiltrating lymphocytes (TILs) in gastric cancer remains controversial. This meta-analysis examines the association between TILs and survival outcomes in gastric cancer.

METHODS

Twenty-two eligible studies were identified using the PubMed and Google Scholar databases. The combined sample size of the 22 studies was 2941, and the median sample size of the individual studies was 122 patients (52-220). The main clinical outcomes examined were overall cancer survival (OCS) and overall cancer relapse-free survival (OCRFS).

RESULTS

Tumor tissue CD3(+) TILs, indicative of pan-T-cell expression, had a positive effect on survival with a hazard ratio (HR) of 0.64 (95% confidence interval [CI] 0.52-0.78) for OCS, as did the non-FOXP3(+) T-cell subgroup with an HR of 0.66 (95% CI 0.57-0.75), particularly in CD8(+) lymphocytes (HR = 0.63, 95% CI 0.48-0.83). On the contrary, high FOXP3(+) T-cell expression was correlated with reduced OCS, with an HR of 1.75 (95% CI 1.26-2.42). Analysis of the seven studies evaluating OCRFS revealed improved OCRFS with infiltration of non-FOXP3(+) TILs with an HR of 0.59 (95% CI 0.42-0.81) but not FOXP3(+) T lymphocytes with an HR of 1.82 (95% CI 1.30-2.53).

CONCLUSION

The results from this meta-analysis suggest that high expression of TILs, mainly by CD8 lymphocytes, may be a potential prognostic biomarker in patients with gastric cancer.

Tristetraprolin Overexpression in Gastric Cancer Cells Suppresses PD-L1 Expression and Inhibits Tumor Progression by Enhancing Antitumor Immunity

The RNA-binding protein tristetraprolin (TTP) binds to adenosine-uridine AU-rich elements in the 3'-untranslated region of messenger RNAs and facilitates rapid degradation of the target mRNAs. Therefore, it regulates the expression of multiple cancer and immunity-associated transcripts. Furthermore, a lack of TTP in cancer cells influences cancer progression and predicts poor survival. Although the functions of TTP on cancer cells have previously been researched, the mechanism of TTP on the interaction between cancer cells with their microenvironment remains undiscovered. In this study, we admed to determine the role of cancer cell TTP during the interaction between tumor and immune cells, specifically regulatory T cells (Tregs). We evaluate the capability of TTP to modulate the antitumor immunity of GC and explored the underlying mechanism. The overexpression of TTP in GC cells dramatically increased peripheral blood mononuclear lymphocyte (PBML) -mediated cytotoxicity against GC cells. Increased cytotoxicity against TTP-overexpressed GC cells by PBMLs was determined by Treg development and infiltration. Surprisingly, we found the stabilization of programmed death-ligand 1 (PD-L1) mRNA was declining while TTP was elevated. The PD-L1 protein level was reduced in TTP-abundant GC cells. PD-L1 gas been found to play a pivotal role in Treg development and functional maintenance in immune system. Taken together, our results suggest the overexpression of TTP in GC cells not only affects cell survival and apoptosis but also increases PBMLs -mediated cytotoxicity against GC cells to decelerate tumor progression. Moreover, we identified PD-L1 as a critical TTP-regulated factor that contributes to inhibiting antitumor immunity.

Comprehensive molecular profiling of the B7 family in gastrointestinal cancer

OBJECTIVES

B7 family has been identified as co-stimulatory or co-inhibitory molecules on T-cell response and plays an important role in tumour mortality and malignancy. In this study, the expression pattern of B7 family in gastrointestinal (GI) cancer was examined. Its upstream regulating mechanism, downstream targets and association with clinical parameters were also studied.

MATERIALS AND METHODS

The expression level of B7 members was analysed by FIREHOUSE. The gene mutation, DNA methylation, association with clinical parameters and downstream network of B7 members were analysed in cBioportal. The mutation frequency was analysed by Catalogue of Somatic Mutations in Cancer (COSMIC) analysis. The phylogenetic tree was constructed in MEGA7. The interaction protein domain analysis was performed by Pfam 31.0.

RESULTS

Differential expression of B7 family molecules was detected in different kinds of GI cancer. High-frequency gene alteration was found in tumour samples. There was negative correlation of promoter methylation and mRNA expression of B7 family members in tumour samples, suggesting the epigenetic basis of B7 family gene deregulation in GI cancer. The overexpression of B7-H1 in pancreatic cancer, B7-H5 in oesophageal cancer and B7-H6 in liver cancer were significantly associated with worse overall survival. Finally, by network analysis, we identified some potential interacting proteins for B7-1/2 and B7-H1/DC.

CONCLUSIONS

Overall, our study suggested that B7 member deregulation was strongly involved in GI cancer tumorigenesis.