SNHG15 promotes gallbladder cancer progression by enhancing the autophagy of tumor cell under nutrition stress.

Gallbladder cancer (GBC) is a major malignant carcinoma of the biliary tract with extremely poor prognosis. Currently, there is no useful therapy strategies for GBC treatment, indicating the unmet mechanism researches for GBC. In this study, our data showed that SNHG15 expression significantly up-regulated and its high expression associated with poor overall survival of patients suffer from GBC. Functional experiments showed that SNHG15 depletion delayed the proliferation and enhanced the apoptosis of GBC tumor cells under the nutrition stress condition, which further confirmed in the subcutaneous xenograft model and liver metastasis model. Mechanistically, SNHG15 could interact with AMPK and facilitate the phosphorylation of AMPK to Tuberous sclerosis complex TSC2, resulting in mTOR suppression and autophagy enhancement, and finally, conferring the GBC cell sustain proliferation under nutrition stress. Taken together, our findings revealed that SNHG15 promotes GBC tumor progression by enhancing the autophagy under poor nutrition tumor microenvironment, which could be a promising targets for GBC.

Development and validation of an MRI-radiomics nomogram for the prognosis of pancreatic ductal adenocarcinoma.

Objective: To develop and validate an MRI-radiomics nomogram for the prognosis of pancreatic ductal adenocarcinoma (PDAC). Background: "Radiomics" enables the investigation of huge amounts of radiological features in parallel by extracting high-throughput imaging data. MRI provides better tissue contrast with no ionizing radiation for PDAC. Methods: There were 78 PDAC patients enrolled in this study. In total, there were 386 radiomics features extracted from MRI scan, which were screened by the least absolute shrinkage and selection operator algorithm to develop a risk score. Cox multivariate regression analysis was applied to develop the radiomics-based nomogram. The performance was assessed by discrimination and calibration. Results: The radiomics-based risk-score was significantly associated with PDAC overall survival (OS) (P < 0.05). With respect to survival prediction, integrating the risk score, clinical data and TNM information into the nomogram exhibited better performance than the TNM staging system, radiomics model and clinical model. In addition, the nomogram showed fine discrimination and calibration. Conclusions: The radiomics nomogram incorporating the radiomics data, clinical data and TNM information exhibited precise survival prediction for PDAC, which may help accelerate personalized precision treatment. Clinical trial registration: clinicaltrials.gov, identifier NCT05313854.

A Gallbladder Cancer Survival Prediction Model Based on Multimodal Fusion Analysis.

BACKGROUND: Gallbladder cancer is the sixth most common malignant gastrointestinal tumor. Radical surgery is currently the only effective treatment, but patient prognosis is poor, with a 5-year survival rate of only 5-10%. Establishing an effective survival prediction model for gallbladder cancer patients is crucial for disease status assessment, early intervention, and individualized treatment approaches. The existing gallbladder cancer survival prediction model uses clinical data-radiotherapy and chemotherapy, pathology, and surgical scope-but fails to utilize laboratory examination and imaging data, limiting its prediction accuracy and preventing sufficient treatment plan guidance. AIMS: The aim of this work is to propose an accurate survival prediction model, based on the deep learning 3D-DenseNet network, integrated with multimodal medical data (enhanced CT imaging, laboratory test results, and data regarding systemic treatments). METHODS: Data were collected from 195 gallbladder cancer patients at two large tertiary hospitals in Shanghai. The 3D-DenseNet network extracted deep imaging features and constructed prognostic factors, from which a multimodal survival prediction model was established, based on the Cox regression model and incorporating patients' laboratory test and systemic treatment data. RESULTS: The model had a C-index of 0.787 in predicting patients' survival rate. Moreover, the area under the curve (AUC) of predicting patients' 1-, 3-, and 5-year survival rates reached 0.827, 0.865, and 0.926, respectively. CONCLUSIONS: Compared with the monomodal model based on deep imaging features and the tumor-node-metastasis (TNM) staging system-widely used in clinical practice-our model's prediction accuracy was greatly improved, aiding the prognostic assessment of gallbladder cancer patients.

Long-term exposure to genistein inhibits the proliferation of gallbladder cancer by downregulating the MCM complex.

Soy isoflavones are natural tyrosine kinase inhibitors closely associated with decreased morbidity and mortality of various tumors. The activation of tyrosine kinases such as ERBB2 is the mechanism by which cholecystitis transforms into gallbladder cancer (GBC), therefore, it is important to investigate the relationship between long-term exposure to soy isoflavones and the occurrence and progression of GBC. This case-control study (n = 85 pairs) found that the high level of plasma soy isoflavone-genistein (GEN) was associated with a lower risk of gallbladder cancer (≥326.00 ng/mL compared to ≤19.30 ng/mL, crude odds ratio 0.15, 95% CI 0.04-0.59; P for trend = 0.016), and that the level of GEN exposure negatively correlated with Ki67 expression in GBC tissue (n = 85). Consistent with these results, the proliferation of GBC cells was inhibited in the long-term exposure models of GEN in vitro and in vivo. The long-term exposure to GEN reduced the tyrosine kinase activity of ERBB2 and impaired the function of the PTK6-AKT-GSK3ß axis, leading to downregulation of the MCM complex in GBC cells. In summary, long-term exposure to GEN associated with soy products intake might play a certain role in preventing GBC and even inhibiting the proliferation of GBC cells.

Development and validation of a prognostic nomogram for gallbladder cancer patients after surgery.

BACKGROUND: Gallbladder cancer is associated with late diagnosis and poor prognosis. Current study aims to develop a prognostic nomogram for predicting survival of gallbladder cancer patients after surgery. METHODS: Two large cohorts were included in this analysis. One consisted of 1753 gallbladder cancer patients from the Surveillance, Epidemiology, and End Results (SEER) database, and the other consisted of 239 patients from Shanghai Renji hospital. Significant prognostic factors were identified and integrated to develop the nomogram. Then the model was subjected to bootstrap internal validation and external validation. RESULTS: Univariate and multivariate analysis indicated that age, tumor histology, T-stage, N-stage and M-stage were significant prognostic factors, which were all included to build the nomogram. The model showed good discrimination, with a concordance index (C-index) of 0.724 (95% CI, 0.708-0.740), and good calibration. Application of the nomogram in the validation cohort still presented good discrimination (C-index, 0.715 [95% CI 0.672-0.758]) and good calibration. In the primary cohort, the C-index of the nomogram was 0.724, which was significantly higher than the Nevin staging system (C-index = 0.671; P < 0.001) and the 8th TNM staging system (C-index = 0.682; P < 0.001). In the validation cohort, the C-index of the nomogram was 0.715, which was also higher than the Nevin staging system (C-index = 0.692; P < 0.05) and the 8th TNM staging system (C-index = 0.688; P = 0.06). CONCLUSIONS: The proposed nomogram resulted in more-accurate prognostic prediction for patients with gallbladder cancer after surgery.

In vivo Analysis of the Resistance of the Meshes to Escherichia coli Infection.

Background: The mesh infection is mostly related to the gram-negative bacteria, such as Escherichia coli (E. coli) for emergency surgery of incarcerated hernia. However, few study investigated the effects of E. coli concentration, mesh materials and antibiotic prophylaxis on mesh infection after hernioplasty. The aim of this study was to evaluate the bacterial resistance to E. coli for three different materials of mesh, and to measure the minimum E. coli concentration for mesh infection with and without antibiotic prophylaxis in a rat model. Methods: Three types of mesh (polytetrafluoroethylene, polypropylene, and biologic meshes) were used in the repair of an acute ventral hernia rat model in the setting of different concentrations of E. coli loads and antibiotics. At the 8th day after surgery, mesh samples were sent for microbiologic and histologic analyses. Results: The positive rates of bacterial culture increased with E. coli concentration. The biologic mesh showed better bacterial resistance compared to polytetrafluoroethylene mesh and polypropylene mesh when the concentration of E. coli ranges from 106 CFU/ml to 108 CFU/ml (P = 0.002 and P = 0.029, respectively). Prophylactical ceftriaxone treatment could not decrease the colonization rate of E. coli at 106 CFU/ml or 108 CFU/ml in each group (P > 0.05). The scores of neovascularization in polypropylene mesh and biologic mesh were similar, which was higher than that of polytetrafluoroethylene mesh (P < 0.05). Compared with other meshes, biologic mesh showed better tolerance to 106 CFU/ml E. coli with respect to inflammation, depth of inflammation, neovascularization, cellular repopulation and foreign body giant cells. Conclusion: The biologic mesh had better E. coli resistance compared to polytetrafluoroethylene mesh and polypropylene mesh when the E. coli concentration is higher than 106 CFU/ml in rats. Antibiotic prophylaxis was useful when the contamination was not particularly severe.

Correction to "Downregulation of FoxM1 inhibits the viability and invasion of gallbladder carcinoma cells, partially dependent on the induction of cellular senescence".

[This corrects the article on p. 9497 in vol. 20, PMID: 25071344.].

Transhepatic hilar approach for Bismuth types III and IV perihilar cholangiocarcinoma with long-term outcomes.

OBJECTIVE: To compare the outcomes of the transhepatic hilar approach and conventional approach for surgical treatment of Bismuth types III and IV perihilar cholangiocarcinoma. METHODS: We retrospectively reviewed the medical records of 82 patients who underwent surgical resection of Bismuth types III and IV perihilar cholangiocarcinoma from 2008 to 2016. The transhepatic hilar approach and conventional approach was used in 36 (43.9%) and 46 (56.1%) patients, respectively. Postoperative complications and overall survival were compared between the two approaches. RESULTS: Similar clinical features were observed between the patients treated by the conventional approach and those treated by the transhepatic hilar approach. The transhepatic hilar approach was associated with less intraoperative bleeding and a lower percentage of Clavien grade 0 to II complications than the conventional approach. However, the transhepatic hilar approach was associated with a higher R0 resection rate and better overall survival. Multivariate analysis showed that using the transhepatic hilar approach, the Memorial Sloan-Kettering Cancer Center classification, and R0 resection were independent risk factors for patient survival. CONCLUSION: The transhepatic hilar approach might be the better choice for surgical resection of Bismuth types III and IV perihilar cholangiocarcinoma because it is associated with lower mortality and improved survival.

Regional lymphadenectomy vs. extended lymphadenectomy for hilar cholangiocarcinoma (Relay-HC trial): study protocol for a prospective, multicenter, randomized controlled trial.

BACKGROUND: The prognostic benefits and safety of extended lymphadenectomy for hilar cholangiocarcinoma remain uncertain. The available evidence is still insufficient concerning its retrospective aspect. The aim of this study is to explore the clinical effect and safety of extended lymphadenectomy compared to regional lymphadenectomy in patients with hilar cholangiocarcinoma. METHODS: The Relay-HC trial is a prospective, multicenter, and randomized controlled trial. Seven hundred and thirty-four eligible patients with resectable perihilar cholangiocarcinoma across 15 tertiary hospitals in China will be randomly assigned (1:1) to receive either regional lymphadenectomy or extended lymphadenectomy. The primary objective is to determine the overall survival after the two approaches. Secondary objectives of the study include the evaluation of perioperative mortality, postoperative complication, and disease-free survival. This study has been approved by the ethics committee of each participating hospital. DISCUSSION: The Relay-HC trial is designed to investigate the prognostic benefits and safety of expanded lymphadenectomy for hilar cholangiocarcinoma. Currently, it has never been investigated in a prospective randomized controlled clinical trial. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR), ChiCTR1800015688 . Registered on 15 April 2018.

Subtypes of Barrett's oesophagus and oesophageal adenocarcinoma based on genome-wide methylation analysis.

OBJECTIVE: To identify and characterise DNA methylation subtypes in oesophageal adenocarcinoma (EAC) and its precursor Barrett's oesophagus (BE). DESIGN: We performed genome-wide DNA methylation profiling on samples of non-dysplastic BE from cancer-free patients (n=59), EAC (n=23), normal squamous oesophagus (n=33) and normal fundus (n=9), and identified methylation subtypes using a recursively partitioned mixture model. We assessed genomic alterations for 9 BE and 22 EAC samples with massively parallel sequencing of 243 EAC-associated genes, and we conducted integrative analyses with transcriptome data to identify epigenetically repressed genes. We also carried out in vitro experiments treating EAC cell lines with 5-Aza-2'-Deoxycytidine (5-Aza-dC), short hairpin RNA knockdown and anticancer therapies. RESULTS: We identified and validated four methylation subtypes of EAC and BE. The high methylator subtype (HM) of EAC had the greatest number of activating events in ERBB2 (p<0.05, Student's t-test) and the highest global mutation load (p<0.05, Fisher's exact test). PTPN13 was silenced by aberrant methylation in the HM subtype preferentially and in 57% of EACs overall. In EAC cell lines, 5-Aza-dC treatment restored PTPN13 expression and significantly decreased its promoter methylation in HM cell lines (p<0.05, Welch's t-test). Inhibition of PTPN13 expression in the SK-GT-4 EAC cell line promoted proliferation, colony formation and migration, and increased phosphorylation in ERBB2/EGFR/Src kinase pathways. Finally, EAC cell lines showed subtype-specific responses to topotecan, SN-38 and palbociclib treatment. CONCLUSIONS: We identified and characterised methylator subtypes in BE and EAC. We further demonstrated the biological and clinical relevance of EAC methylator subtypes, which may ultimately help guide clinical management of patients with EAC.

Author Correction: Targeting wild-type KRAS-amplified gastroesophageal cancer through combined MEK and SHP2 inhibition.

In the Supplementary Information originally published with this article, a lane was missing in the ß-actin blot in Supplementary Fig. 2. The lane has been added. The error has been corrected in the Supplementary Information associated with this article.

Targeting wild-type KRAS-amplified gastroesophageal cancer through combined MEK and SHP2 inhibition.

The role of KRAS, when activated through canonical mutations, has been well established in cancer1. Here we explore a secondary means of KRAS activation in cancer: focal high-level amplification of the KRAS gene in the absence of coding mutations. These amplifications occur most commonly in esophageal, gastric and ovarian adenocarcinomas2-4. KRAS-amplified gastric cancer models show marked overexpression of the KRAS protein and are insensitive to MAPK blockade owing to their capacity to adaptively respond by rapidly increasing KRAS-GTP levels. Here we demonstrate that inhibition of the guanine-exchange factors SOS1 and SOS2 or the protein tyrosine phosphatase SHP2 can attenuate this adaptive process and that targeting these factors, both genetically and pharmacologically, can enhance the sensitivity of KRAS-amplified models to MEK inhibition in both in vitro and in vivo settings. These data demonstrate the relevance of copy-number amplification as a mechanism of KRAS activation, and uncover the therapeutic potential for targeting of these tumors through combined SHP2 and MEK inhibition.

Synergistic effect of nutlin-3 combined with aspirin in hepatocellular carcinoma HepG2 cells through activation of Bcl-2/Bax signaling pathway.

Aspirin as an antitumor drug has been studied in various malignancies with regards to its effects on apoptosis, proliferation, metastasis and senescence of tumor cells. However, the clinical application is limited by its side effects. Nutlin­3 is a novel antitumor compound, which has not been clinically approved. The present study investigated the value of combining aspirin and nutlin­3 on hepatocellular carcinoma (HCC) cells. MTT was performed to detect the proliferation of HepG2 cells treated with aspirin or/and nutlin­3. Transwell invasion assays were performed to estimate the invasion ability of HepG2 cells treated with aspirin or/and nutlin­3. Then the apoptotic analysis of HepG2 cells evaluated the synergistic effect of aspirin and nutlin­3. Apoptosis markers, including B­cell lymphoma 2 (Bcl­2), Bcl­2­associated X protein (Bax), caspase­3, caspase­8 and caspase­9 were estimated by western blot analysis at various time points. In addition, a Xenograft mouse model was established by infection with HepG2 cells, and aspirin and/or nutlin­3 was administrated to verify the anti­apoptotic effect of the two drugs in vivo. A high dose of aspirin and nutlin­3 inhibit the proliferation and apoptosis of HepG2 cells. The antitumor effect was enhanced with the combined treatment of the two drugs, particularly in the group with a low concentration of aspirin and nutlin­3. Nutlin­3 was able to increase the level of Bax in HepG2 cells treated with aspirin significantly after treatment for 8 h. When treated with a low concentration of aspirin and nutlin­3, the level of Bax in HepG2 cells was enhanced for 2 h. In the animal model, tumor volume and tumor angiogenesis were significantly decreased in combination group compared with other groups (P<0.01). Although there were side effects in the group treated with aspirin alone, no side effects were observed in the combination group. Nutlin­3 enhanced the apoptotic effect of a low dose of aspirin by upregulating Bax expression in the HepG2 cell line and in vivo. The synergistic effect of nutlin­3 in aspirin antitumor therapy contributed to diminishing the dose of aspirin required and decreased the occurrence of adverse drug events in HCC through targeting the Bcl­2/Bax signaling pathway.

CDK4/6 or MAPK blockade enhances efficacy of EGFR inhibition in oesophageal squamous cell carcinoma.

Oesophageal squamous cell carcinoma is a deadly disease where systemic therapy has relied upon empiric chemotherapy despite the presence of genomic alterations pointing to candidate therapeutic targets, including recurrent amplification of the gene encoding receptor tyrosine kinase epidermal growth factor receptor (EGFR). Here, we demonstrate that EGFR-targeting small-molecule inhibitors have efficacy in EGFR-amplified oesophageal squamous cell carcinoma (ESCC), but may become quickly ineffective. Resistance can occur following the emergence of epithelial-mesenchymal transition and by reactivation of the mitogen-activated protein kinase (MAPK) pathway following EGFR blockade. We demonstrate that blockade of this rebound activation with MEK (mitogen-activated protein kinase kinase) inhibition enhances EGFR inhibitor-induced apoptosis and cell cycle arrest, and delays resistance to EGFR monotherapy. Furthermore, genomic profiling shows that cell cycle regulators are altered in the majority of EGFR-amplified tumours and a combination of cyclin-dependent kinase 4/6 (CDK4/6) and EGFR inhibitors prevents the emergence of resistance in vitro and in vivo. These data suggest that upfront combination strategies targeting EGFR amplification, guided by adaptive pathway reactivation or by co-occurring genomic alterations, should be tested clinically.

Induction of renal artery hyperresponsiveness by alpha1-adrenoceptor in hepatorenal syndrome.

OBJECTIVE: To investigate the potential role of alpha1-adrenoceptor (α1-AR) in the pathogenesis of hepatorenal syndrome. METHODS: Hepatorenal syndrome was induced in male rats by intraperitoneal injection of D-galactosamine and orally treatment with α1-AR antagonist tamsulosin. Hyperresponsiveness of the renal artery contraction was evaluated by the laser-Doppler flowmetry and multimyograph system, while renal blood flow (cortical and medullary perfusion) was simultaneously measured. Renal artery ring segment tone was recorded with the myograph system, and concentration-response curves were obtained by cumulative administration of agonists. RESULTS: This model developed acute renal and liver failure without renal damage in pathology, accompanied by significant hyperresponsiveness of renal artery contraction. After hepatorenal syndrome, plasma concentrations of tumor necrosis factor-α increased by two-fold, and α1-AR was significantly activated in the renal artery. Concentration-dependent vasoconstriction induced by noradrenaline was significantly decreased in the renal arteries of hepatorenal syndrome rat because of gradually decreased renal blood flow. Administration of tamsulosin prevented renal failure when given before the onset of liver injury, but it had no effect on liver injury by itself. CONCLUSION: α1-AR expression is positively associated with renal vasoconstriction induced by renal artery hyperresponsiveness in HRS. Therefore, α1-AR may be a potential target in the treatment of HRS.

Sox2 Suppresses Gastric Tumorigenesis in Mice.

Sox2 expression marks gastric stem and progenitor cells, raising important questions regarding the genes regulated by Sox2 and the role of Sox2 itself during stomach homeostasis and disease. By using ChIP-seq analysis, we have found that the majority of Sox2 targets in gastric epithelial cells are tissue specific and related to functions such as endoderm development, Wnt signaling, and gastric cancer. Unexpectedly, we found that Sox2 itself is dispensable for gastric stem cell and epithelial self-renewal, yet Sox2(+) cells are highly susceptible to tumorigenesis in an Apc/Wnt-driven mouse model. Moreover, Sox2 loss enhances, rather than impairs, tumor formation in Apc-deficient gastric cells in vivo and in vitro by inducing Tcf/Lef-dependent transcription and upregulating intestinal metaplasia-associated genes, providing a mechanistic basis for the observed phenotype. Together, these data identify Sox2 as a context-dependent tumor suppressor protein that is dispensable for normal tissue regeneration but restrains stomach adenoma formation through modulation of Wnt-responsive and intestinal genes.

Prognostic significance of neutrophil to lymphocyte ratio in patients with gallbladder carcinoma.

BACKGROUND: Numerous literature suggest that the preoperative neutrophil to lymphocyte ratio (NLR) is correlated to the prognosis of various cancers. However, the prognostic significance of NLR in gallbladder carcinoma (GBC) remains to be determined. METHODS: Data from 316 GBC patients with surgical treatment were reviewed retrospectively. A receiver operating characteristic (ROC) curve was performed to determine an optimal cut-off value for NLR. The Kaplan-Meier method and Cox regression proportional hazard model were performed to evaluate prognostic factors. RESULTS: The optimal cut-off point for NLR was 2.61 according to the ROC curve. According to the univariable analysis, NLR, differentiation and TNM stage were associated with GBC prognosis. GBC patients with NLR > 2.61 have worsened 5-year overall survival (OS) compared to patients with NLR ≤ 2.61 (P < 0.001). Multiple analyses indicated that NLR (hazard ratio (HR) 1.65; 95 percent confidence interval (95% CI) 1.25-2.17), differentiation (HR 1.25; 95% CI 0.97-1.62) and TNM stage (HR 3.79; 95% CI 2.09-6.87) were independent prognostic factors for GBC. GBC patients in stage III/IV, NLR > 2.61 exhibited worse OS compared to patients with NLR ≤ 2.61 (P < 0.05). A prognostic evaluation model based on the independent prognostic factors was established. CONCLUSION: NLR is associated with GBC prognosis and is a potential prognostic marker for GBC, not only preoperatively but also postoperatively.

Assessing the clinical utility of genomic expression data across human cancers.

Cancer molecular profiling provides better understanding of tumor mechanisms and helps to improve the existing cancer management. Here we present the gene expression signatures from ~9000 human tumors with clinical information across 32 malignancies from The Cancer Genome Atlas project (TCGA). Major predictors from the RNA sequencing data that were significantly correlated with cancer survival were identified. The expression level of these prognostic genes revealed significant genomic pathways that were clinically relevant to survival outcomes across human cancers. Furthermore, it is shown that in most cancer types, combinations of these genomic signatures with clinical information might yield improved predictions. Thus, with respect to clinical utility, our study reveals the promising values of genomic data from the pan-cancer perspective.

Association between telomere length and survival in cancer patients: a meta-analysis and review of literature.

The relationship between telomere length and cancer survival has been widely studied. To gain a deeper insight, we reviewed the published studies. A total of 29 studies evaluated telomere length in the peripheral blood; 22 studies evaluated telomere length in the tumor tissue. First, in the peripheral blood studies, for solid tumor patients with shortened telomere length, the combined hazard ratios (HRs) for mortality and tumor progression were 1.21 (95%CI, 1.10-1.32) and 1.71 (95%CI, 1.37-2.13), respectively. Meanwhile, in hematology malignancy, the combined HRs for mortality and tumor progression were 2.83 (95%CI, 2.14-3.74) and 2.65 (95%CI, 2.18-3.22), respectively. Second, in the studies that use tumor tissue, for patients with shortened telomeres, the combined HRs for mortality and tumor progression were 1.26 (95%CI, 0.95-1.66) and 1.65 (95%CI, 1.26-2.15), respectively. In the studies that calculate the telomere length ratios of tumor tissue to adjacent normal mucosa, for patients with lower telomere length ratios, the combined HRs were 0.66 (95%CI, 0.53-0.83) and 0.74 (95%CI, 0.41-1.32) for mortality and tumor progression, respectively. In conclusion, shortened telomere in peripheral blood and tumor tissue might indicate poor survival for cancer patients. However, by calculating the telomere length ratios of tumor tissue to adjacent normal mucosa, the lower ratio might indicate better survival.

Abundant PD-L1 expression in Epstein-Barr Virus-infected gastric cancers.

Gastric cancer (GC) is a deadly disease with limited treatment options. Recent studies with PD-1 inhibition have shown promising results in GC, but key questions remain regarding which GC subclass may respond best. In other cancers, expression of the PD-1 ligand PD-L1 has been shown to identify cancers with greater likelihood of response to PD-1 blockade. We here show with immunohistochemistry that Epstein-Barr Virus (EBV)+ GCs (n = 32) have robust PD-L1 expression not seen in other GCs. In EBV+ GC, we observed PD-L1 staining in tumor cells in 50% (16/32) and immune cells in 94% (30/32) of cases. Among EBV-negative GCs, PD-L1 expression within tumors cells was observed only in cases with microsatellite instability (MSI), although 35% of EBV-/MSS GCs possessed PD-L1 expression of inflammatory cells. Moreover, distinct classes of GC showed different patterns of PD-L1+ immune cell infiltrations. In both EBV+ and MSI tumors, PD-L1+ inflammatory cells were observed to infiltrate the tumor. By contrast, such cells remained at the tumor border of EBV-/MSS GCs. Consistent with these findings, we utilized gene expression profiling of GCs from The Cancer Genome Atlas study to demonstrate that an interferon-γ driven gene signature, an additional proposed marker of sensitivity to PD-1 therapy, were enriched in EBV+ and MSI GC. These data suggest that patients with EBV+ and MSI GC may have greater likelihood of response to PD-1 blockade and that EBV and MSI status should be evaluated as variables in clinical trials of these emerging inhibitors.