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Polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) are pathologically activated neutrophils that potently impair immunotherapy responses. The chemokine receptor CXCR4, a central regulator of hematopoiesis, represents an attractive PMN-MDSC target1. Here, we fused a secreted CXCR4 partial agonist TFF2 to mouse serum albumin (MSA) and demonstrated that TFF2-MSA peptide synergized with anti-PD-1 to induce tumor regression or eradication, inhibited distant metastases, and prolonged survival in multiple gastric cancer (GC) models. Using histidine decarboxylase (Hdc)-GFP transgenic mice to track PMN-MDSC in vivo , we found TFF2-MSA selectively reduced the immunosuppressive Hdc-GFP + CXCR4 hi tumor PMN-MDSCs while preserving proinflammatory neutrophils, thereby boosting CD8 + T cell-mediated anti-tumor response together with anti-PD-1. Furthermore, TFF2-MSA systemically reduced PMN-MDSCs and bone marrow granulopoiesis. In contrast, CXCR4 antagonism plus anti-PD-1 failed to provide a similar therapeutic benefit. In GC patients, expanded PMN-MDSCs containing a prominent CXCR4 + LOX-1 + subset are inversely correlated with the TFF2 level and CD8 + T cells in circulation. Collectively, our studies introduce a strategy of using CXCR4 partial agonism to restore anti-PD-1 sensitivity in GC by targeting PMN-MDSCs and granulopoiesis.

Diffuse-type gastric cancer (DGC) accounts for approximately one-third of gastric cancer diagnoses but is a more clinically aggressive disease with peritoneal metastases and inferior survival compared with intestinal-type gastric cancer (IGC). The understanding of the pathogenesis of DGC has been relatively limited until recently. Multiomic studies, particularly by The Cancer Genome Atlas, have better characterized gastric adenocarcinoma into molecular subtypes. DGC has unique molecular features, including alterations in CDH1, RHOA, and CLDN18-ARHGAP26 fusions. Preclinical models of DGC characterized by these molecular alterations have generated insight into mechanisms of pathogenesis and signaling pathway abnormalities. The currently approved therapies for treatment of gastric cancer generally provide less clinical benefit in patients with DGC. Based on recent phase II/III clinical trials, there is excitement surrounding Claudin 18.2-based and FGFR2b-directed therapies, which capitalize on unique biomarkers that are enriched in the DGC populations. There are numerous therapies targeting Claudin 18.2 and FGFR2b in various stages of preclinical and clinical development. Additionally, there have been preclinical advancements in exploiting unique therapeutic vulnerabilities in several models of DGC through targeting of the focal adhesion kinase (FAK) and Hippo pathways. These preclinical and clinical advancements represent a promising future for the treatment of DGC., (© 2024. The Author(s).)

Cyclin E overexpression as a result of CCNE1 amplification is a critical driver of genomic instability in gastric cancer, but its clinical implication is largely unknown. Thus, we integrated genomic, transcriptomic, and immune profiling analysis of 7,083 esophagogastric tumors and investigated the impact of CCNE1 amplification on molecular features and treatment outcomes. We identified CCNE1 amplification in 6.2% of esophageal adenocarcinoma samples, 7.0% of esophagogastric junction carcinoma, 4.2% of gastric adenocarcinoma samples, and 0.8% of esophageal squamous cell carcinoma. Metastatic sites such as lymph node and liver showed an increased frequency of CCNE1 amplification relative to primary tumors. Consistent with a chromosomal instability phenotype, CCNE1 amplification was associated with decreased CDH1 mutation and increased TP53 mutation and ERBB2 amplification. We observed no differences in immune biomarkers such as PD-L1 expression and tumor mutational burden comparing CCNE1-amplified and nonamplified tumors, although CCNE1 amplification was associated with changes in immune populations such as decreased B cells and increased M1 macrophages from transcriptional analysis. Real-world survival analysis demonstrated that patients with CCNE1-amplified gastric cancer had worse survival after trastuzumab for HER2-positive tumors, but better survival after immunotherapy. These data suggest that CCNE1-amplified gastric cancer has a distinct molecular and immune profile with important therapeutic implications, and therefore further investigation of CCNE1 amplification as a predictive biomarker is warranted., Significance: Advanced gastric cancer has a relatively dismal outcome with a 5-year overall survival of less than 10%. Furthermore, while comprehensive molecular analyses have established molecular subtypes within gastric cancers, biomarkers of clinical relevance in this cancer type are lacking. Overall, this study demonstrates that CCNE1 amplification is associated with a distinct molecular profile in gastric cancer and may impact response to therapy, including targeted therapy and/or immunotherapy., (© 2024 The Authors; Published by the American Association for Cancer Research.)

Background: The addition of nivolumab to chemotherapy improves survival in patients with advanced oesophagogastric (oesophageal, gastric, or gastro-oesophageal junction) adenocarcinoma; however, outcomes remain poor. We assessed the safety and activity of regorafenib in combination with nivolumab and chemotherapy in the first-line treatment of advanced oesophagogastric adenocarcinoma., Methods: This investigator-initiated, single-arm, phase 2 trial in adult patients (aged ≥18 years) with previously untreated, HER2-negative, metastatic oesophagogastric adenocarcinoma was done at the Memorial Sloan Kettering Cancer Center (New York, NY, USA). Eligible patients had measurable disease or non-measurable disease that was evaluable (defined by Response Evaluation Criteria in Solid Tumours [RECIST] version 1.1) and Eastern Cooperative Oncology Group performance status of 0 or 1. Patients received FOLFOX chemotherapy (fluorouracil [400 mg/m 2 bolus followed by 2400 mg/m 2 over 48 h], leucovorin [400 mg/m 2 ], and oxaliplatin [85 mg/m 2 ]) and nivolumab (240 mg) intravenously on days 1 and 15, and oral regorafenib (80 mg) on days 1-21 of a 28-day cycle. Treatment was continued until disease progression (defined by RECIST version 1.1), unacceptable toxicity, or withdrawal of consent. The primary endpoint was 6-month progression-free survival in the per-protocol population (ie, all participants who received a dose of all study treatments). The regimen would be considered worthy of further investigation if at least 24 of 35 patients were progression free at 6 months. Safety was assessed in all participants who received at least one dose of any study treatment. This trial is registered with ClinicalTrials.gov, NCT04757363, and is now complete., Findings: Between Feb 11, 2021, and May 4, 2022, 39 patients were enrolled, received at least one dose of study drug, and were included in safety analyses. 35 patients were evaluable for 6-month progression-free survival. Median age was 57 years (IQR 52-66), nine (26%) patients were women, 26 (74%) were men, 28 (80%) were White, and seven (20%) were Asian. At data cutoff (March 3, 2023), median follow-up was 18·1 months (IQR 12·7-20·4). The primary endpoint was reached, with 25 (71%; 95% CI 54-85) of 35 patients progression free at 6 months. Nine (26%) of 35 patients had disease progression and one (3%) patient died; the death was unrelated to treatment. The most common adverse event of any grade was fatigue (36 [92%] of 39). The most common grade 3 or 4 adverse events were decreased neutrophil count (18 [46%]), hypertension (six [15%]), dry skin, pruritus, or rash (five [13%]), and anaemia (four [10%]). Serious treatment-related adverse events occurred in ten (26%) patients, which were acute kidney injury (three [8%]), hepatotoxicity (two [5%]), sepsis (two [5%]), dry skin, pruritus, or rash (one [3%]), nausea (one [3%]), and gastric perforation (one [3%]). There were no treatment-related deaths., Interpretation: Regorafenib can be safely combined with nivolumab and chemotherapy and showed promising activity in HER2-negative metastatic oesophagogastric cancer. A randomised, phase 3 clinical trial is planned., Funding: Bristol Myers Squibb, Bayer and National Institutes of Health/National Cancer Institute., Competing Interests: Declaration of interests SLC reports stock ownership in Pfizer, Moderna, and BioNTech. RHM reports consulting with PureTech Health, advisory board with IDEAYA Biosciences, and research funding from Nimbus Therapeutics. JFC reports an investigator role on a research study sponsored by Paige.AI. GYK reports consulting fees from AstraZeneca, Bristol-Myers Squibb, Merck, Pieris, and Zymeworks; and grants or contracts from AstraZeneca, Bristol-Myers Squibb, CARsgen, Zymeworks, Daiichi Sankyo, Oncolys, Pieris, and Adaptimmune. SBM reports honoraria from Natera, Bicara, Novartis, Basilea, Elevation Oncology, Purple Oncology, Pinetree Therapeutics, and Daiichi Sankyo; research support from Epic Sciences; grant funding from the Conquer Cancer Foundation; and research travel support from AstraZeneca outside of the submitted work. MAS reports consulting for Boston Scientific and Novo Nordisk. MEL reports ownership or equity interests with Apricity Health; intellectual property rights with John Wiley & Sons, and the Taylor & Francis Group; uncompensated provision of services for Oncoderm; and provision of services for Adgero Biopharmaceuticals, the American Academy of Dermatology, the American Society of Pediatric Hematology/Oncology, Apricity Health, AstraZeneca, Atlantic Canada Oncology Group, BGB Communications, Bicara Therapeutics, Deciphera, DelMar Pharmaceuticals, EMD Serono, GCO Global, Hoth Therapeutics, Incyte, Innovaderm Research, Johnson & Johnson, La Fonderie Ressources, La Roche-Posay, Loxo Oncology, Lutris Pharma, MJH Life Sciences, the Michigan Dermatological Society, NKMax America, NanOlogy, Novartis, Novartis Pharmaceuticals Corporation, Novocure, OnQuality Pharmaceuticals, Patient Resource, QED Therapeutics, RBC Consulting, RMEI Medical Education, Society for Immunotherapy of Cancer, Takeda Millennium, The Lynx Group, Tyra Biosciences, Varsona Pharmaceuticals, WebMD, Wolters Kluwer, and eSquared Communication Consulting. JS reports consulting for Paige.AI. MFB reports consulting for Eli Lilly and AstraZeneca (not related to this work). YYJ reports research funding from Bayer, Bristol Myers Squibb, Memorial Sloan Kettering Cancer Center Cycle for Survival, the United States Department of Defense, Eli Lilly, Fred's Team, Genentech/Roche, Merck, the National Cancer Institute, and RGENIX; advisory board or consulting with AbbVie, Amerisource Bergen, Ask-Gene Pharma, Arcus Biosciences, Astellas, Astra Zeneca, Basilea Pharmaceutica, Bayer, Bristol Myers Squibb, Clinical Care Options, Daiichi-Sankyo, Eli Lilly, Geneos Therapeutics, GlaxoSmithKline, Guardant Health, Imedex, Imugene, Lynx Health, Merck, Merck Serono, Mersana Therapeutics, Michael J Hennessy Associates, Paradigm Medical Communications, PeerView Institute, Pfizer, Research to Practice, RGENIX, Seagen, Silverback Therapeutics, and Zymeworks; and stock options in RGENIX. All other authors declare no competing interests., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Gastric cancer is a highly prevalent and lethal disease worldwide. Given the insidious nature of the presenting symptoms, patients are frequently diagnosed with advanced, unresectable disease. However, many patients will present with locally advanced gastric cancer (LAGC), which is often defined as the primary tumor extending beyond the muscularis propria (cT3-T4) or having nodal metastases (cN+) disease and without distant metastases (cM0). LAGC is typically treated with surgical resection and perioperative chemotherapy. The treatment of LAGC remains a challenge, given the heterogeneity of this disease, and the optimal multimodal treatment regimen may be different for different LAGC subtypes. However, many promising treatments are on the horizon based on knowledge of molecular subtypes and key biomarkers of LAGC, such as microsatellite instability, HER2, Claudin 18.2, FGFR2, and PD-L1. This review will expand upon the discussion of current standard neoadjuvant and adjuvant therapies for LAGC and explore the ongoing and future clinical trials for novel therapies, with information obtained from searches in PubMed and ClinicalTrials.gov.

Background: Patients (pts) with locally advanced gastric adenocarcinoma (LAGA) often receive neoadjuvant chemotherapy. A minority of patients do not respond to chemotherapy and thus may benefit from upfront surgery. Patient-derived organoids (PDOs) are an in vitro model that may mimic the chemotherapy response of the original tumors., Methods: PDOs were generated from endoscopic biopsies of LAGAs prior to the initiation of chemotherapy and treated with the two chemotherapy regimens: FLOT and FOLFOX. Cell proliferation was assayed after 3-6 days. Following chemotherapy, pts underwent surgical resection, and percent pathological necrosis was determined., Results: Successful PDOs were obtained from 13 of 24 (54%) LAGAs. Failure to generate PDOs were due to contamination (n = 3, 13%), early senescence (n = 3, 13%), and late senescence (n = 5, 21%). By H&E staining, there were significant similarities in tumor morphology and high concordance in immunohistochemical expression of 6 markers between tumors and derived PDOs. Four of 13 pts with successful PDOs did not undergo chemotherapy and surgery. For the remaining 9 pts, percent necrosis in resected tumors was ≤ 50% in 2 pts. The corresponding PDOs from these 2 pts were clearly chemoresistant outliers. The Pearson correlation coefficient between chemosensitivity of PDOs to FOLFOX (n = 2) or FLOT (n = 7) and percent tumor necrosis in resected tumors was 0.87 (p = 0.003)., Conclusions: PDOs from pts with LAGAs in many respects mimic the original tumors from which they are derived and may be used to predict resistance to neoadjuvant chemotherapy., Synopsis: Patient-derived organoids (PDOs) can serve as personalized in vitro models of patient tumors. In this study, PDOs from locally advanced gastric cancers were able to reliably predict resistance to neoadjuvant chemotherapy., (© 2023. The Society for Surgery of the Alimentary Tract.)

Gastric adenocarcinoma is by far the most common form of gastric cancer (GC) and is a highly lethal form of cancer arising from the gastric epithelium. GC is an important area of focus of the medical community, given its often late-stage of diagnosis and associated high mortality rate. While surgery and chemotherapy remain the primary treatments, attention has been drawn to the use of immunologic therapies, which have shown promise in the treatment of other malignancies. The role for immune-based therapies has become clearer as we obtain a greater understanding of the role of the immune system in gastric cancer formation and growth. A variety treatment to augment the immune system are under evaluation in clinical trials, and these include immune checkpoint inhibitors, antibody-drug conjugates, and immune cell-based therapies. Here, we review the immune landscape and immune-based therapies for GC.

Metastatic colonization is the primary cause of death from colorectal cancer (CRC). We employed genome-scale in vivo short hairpin RNA (shRNA) screening and validation to identify 26 promoters of CRC liver colonization. Among these genes, we identified a cluster that contains multiple targetable genes, including ITPR3, which promoted liver-metastatic colonization and elicited similar downstream gene expression programs. ITPR3 is a caffeine-sensitive inositol 1,4,5-triphosphate (IP3) receptor that releases calcium from the endoplasmic reticulum and enhanced metastatic colonization by inducing expression of RELB, a transcription factor that is associated with non-canonical NF-κB signaling. Genetic, cell biological, pharmacologic, and clinical association studies revealed that ITPR3 and RELB drive CRC colony formation by promoting cell survival upon substratum detachment or hypoxic exposure. RELB was sufficient to drive colonization downstream of ITPR3. Our findings implicate the ITPR3/calcium/RELB axis in CRC metastatic colony formation and uncover multiple clinico-pathologically associated targetable proteins as drivers of CRC metastatic colonization., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Purpose: Paclitaxel plus ramucirumab is a standard second-line regimen for patients with advanced gastric adenocarcinoma, but clinical benefit remains modest. One potential resistance mechanism to VEGFR2 inhibition is activation of the PDGF/PDGFR pathway, which can be blocked by the selective inhibitor crenolanib. Therefore, we performed a phase I/Ib study of crenolanib in combination with paclitaxel/ramucirumab., Methods: Patients with metastatic esophagogastric adenocarcinoma refractory to first-line therapy received escalating doses of crenolanib [60 mg twice daily (BID) to 100 mg three times daily (TID)] in combination with paclitaxel 80 mg/m 2 intravenously on days 1, 8 and 15 and ramucirumab 8 mg/kg intravenously on days 1 and 15 of a 28-day cycle. The primary objective was to determine the maximally tolerated dose (MTD) of crenolanib. Additional patients were enrolled in the dose expansion cohort to assess 6-month progression-free survival (PFS) at the MTD., Results: We enrolled 19 patients in the dose escalation phase and 8 patients in the dose expansion phase at the MTD of crenolanib 100 mg BID. Common grade 3/4 treatment-emergent adverse events included leukopenia (19%), anemia (11%) and neutropenia (11%). In the 14 patients treated at the MTD, 6-month PFS was 43% [95% confidence interval (CI) 23-78%] and the objective response rate (ORR) was 42% (95% CI 15-72%). The trial was terminated early due to withdrawal of crenolanib by the sponsor., Conclusions: The addition of crenolanib to paclitaxel/ramucirumab is safe and well-tolerated at a dose level up to 100 mg BID., Clinical Trial Registration: NCT03193918. June 19, 2017., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: Comprehensive genomic profiling has defined key oncogenic drivers and distinct molecular subtypes in esophagogastric cancer; however, the number of clinically actionable alterations remains limited. To establish preclinical models for testing genomically driven therapeutic strategies, we generated and characterized a large collection of esophagogastric cancer patient-derived xenografts (PDXs)., Materials and Methods: We established a biobank of 98 esophagogastric cancer PDX models derived from primary tumors and metastases. Clinicopathologic features of each PDX and the corresponding patient sample were annotated, including stage at diagnosis, treatment history, histology, and biomarker profile. To identify oncogenic DNA alterations, we analyzed and compared targeted sequencing performed on PDX and parent tumor pairs. We conducted xenotrials in genomically defined models with oncogenic drivers., Results: From April 2010 to June 2019, we implanted 276 patient tumors, of which 98 successfully engrafted (35.5%). This collection is enriched for PDXs derived from patients with human epidermal growth factor receptor 2-positive esophagogastric adenocarcinoma (62 models, 63%), the majority of which were refractory to standard therapies including trastuzumab. Factors positively correlating with engraftment included advanced stage, metastatic origin, intestinal-type histology, and human epidermal growth factor receptor 2-positivity. Mutations in TP53 and alterations in receptor tyrosine kinases ( ERBB2 and EGFR ), RAS/PI3K pathway genes, cell-cycle mediators ( CDKN2A and CCNE1 ), and CDH1 were the predominant oncogenic drivers, recapitulating clinical tumor sequencing. We observed antitumor activity with rational combination strategies in models established from treatment-refractory disease., Conclusion: The Memorial Sloan Kettering Cancer Center PDX collection recapitulates the heterogeneity of esophagogastric cancer and is a powerful resource to investigate mechanisms driving tumor progression, identify predictive biomarkers, and develop therapeutic strategies for molecularly defined subsets of esophagogastric cancer., Competing Interests: Daniela MolenaHonoraria: Bristol Myers Squibb/Pfizer, MerckConsulting or Advisory Role: Johnson & Johnson, UroGen pharma, Boston Scientific, AstraZeneca/MedImmune Steven B. MaronStock and Other Ownership Interests: Calithera BiosciencesConsulting or Advisory Role: Natera, Basilea, Daichi Sankyo, Bicara Therapeutics, NovartisResearch Funding: Roche/Genentech (Inst), Guardant Health (Inst)Travel, Accommodations, Expenses: Bayer David R. JonesConsulting or Advisory Role: Merck, AstraZeneca Jaclyn F. HechtmanEmployment: NeoGenomics LaboratoriesStock and Other Ownership Interests: NeoGenomics LaboratoriesHonoraria: WebMD, Illumina, BayerConsulting or Advisory Role: Cor2Ed, Axiom Healthcare Strategies, BayerResearch Funding: Bayer, Lilly, Boehringer Ingelheim David B. SolitThis author is a member of the JCO Precision Oncology Editorial Board. Journal policy recused the author from having any role in the peer review of this manuscript.Stock and Other Ownership Interests: Scorpion Therapeutics, Vividion Therapeutics, Fore BiotherapeuticsConsulting or Advisory Role: Pfizer, Lilly, BridgeBio Pharma, Scorpion Therapeutics, Vividion Therapeutics, Syros Pharmaceuticals Yelena Y. JanjigianStock and Other Ownership Interests: RgenixConsulting or Advisory Role: Pfizer, Merck, Bristol Myers Squibb, Merck Serono, Daiichi Sankyo, Rgenix, Bayer, Imugene, AstraZeneca, Lilly, Zymeworks, Basilea Pharmaceutical, Michael J. Hennessy Associates, Paradigm, Seattle GeneticsResearch Funding: Bayer (Inst), Rgenix (Inst), Bristol Myers Squibb (Inst), Merck (Inst), Lilly (Inst), NCI (Inst), Department of Defense (Inst), Cycle for Survival (Inst), Fred's Team (Inst), Genentech/Roche (Inst)Other Relationship: Clinical Care Options, Axis Medical Education, Research to PracticeNo other potential conflicts of interest were reported.

Allogeneic hematopoietic cell transplantation (allo-HCT) is a potentially curative procedure for a large number of diseases. However, the greatest barriers to the success of allo-HCT are relapse and graft-versus-host-disease (GVHD). Many studies have examined the reconstitution of the immune system after allo-HCT and searched for factors associated with clinical outcome. Serum biomarkers have also been studied to predict the incidence and prognosis of GVHD. However, the use of multiparametric immunophenotyping has been less extensively explored: studies usually focus on preselected and predefined cell phenotypes and so do not fully exploit the richness of flow cytometry data. Here we aimed to identify cell phenotypes present 30 days after allo-HCT that are associated with clinical outcomes in 37 patients participating in a trial relating to the prevention of GVHD, derived from 82 flow cytometry markers and 13 clinical variables. To do this we applied variable selection methods in a competing risks modeling framework, and identified specific subsets of T, B, and NK cells associated with relapse. Our study demonstrates the value of variable selection methods for mining rich, high dimensional clinical data and identifying potentially unexplored cell subpopulations of interest.

DEAD box RNA helicases regulate diverse facets of RNA biology. Proteins of this family carry out essential cellular functions, and emerging literature is revealing additional roles in immune defense. Using RNA interference screening, we identified an evolutionarily conserved antiviral role for the helicase DDX56 against the alphavirus Sindbis virus (SINV), a mosquito-transmitted pathogen that infects humans. Depletion of DDX56 enhanced infection in Drosophila and human cells. Furthermore, we found that DDX56 also controls the emerging alphavirus chikungunya virus (CHIKV) through an interferon-independent mechanism. Using cross-linking immunoprecipitation (CLIP-Seq), we identified a predicted stem-loop on the viral genomic RNA bound by DDX56. Mechanistically, we found that DDX56 levels increase in the cytoplasm during CHIKV infection. In the cytoplasm, DDX56 impacts the earliest step in the viral replication cycle by binding and destabilizing the incoming viral genomic RNA, thereby attenuating infection. Thus, DDX56 is a conserved antiviral RNA binding protein that controls alphavirus infection. IMPORTANCE Arthropod-borne viruses are diverse pathogens and include the emerging virus chikungunya virus, which is associated with human disease. Through genetic screening, we found that the conserved RNA binding protein DDX56 is antiviral against chikungunya virus in insects and humans. DDX56 relocalizes from the nucleus to the cytoplasm, where it binds to a stem-loop in the viral genome and destabilizes incoming genomes. Thus, DDX56 is an evolutionarily conserved antiviral factor that controls alphavirus infection., (Copyright © 2020 Taschuk et al.)

Background: Angiogenesis is critical to gastroesophageal adenocarcinoma growth and metastasis. Regorafenib is a multikinase inhibitor targeting angiogenic and stromal receptor tyrosine kinases. We evaluated whether regorafenib augments the antitumor effect of first-line chemotherapy in metastatic esophagogastric cancer., Materials and Methods: Patients with previously untreated metastatic gastroesophageal adenocarcinoma received 5-fluorouracil, leucovorin, and oxaliplatin (mFOLFOX6) every 14 days and regorafenib 160 mg daily on days 4 to 10 of each 14-day cycle. The primary endpoint was 6-month progression-free survival (PFS). To identify predictive biomarkers of outcome, we examined correlations between genomic characteristics of sequenced pretreatment tumors and PFS., Results: Between August 2013 and November 2014, 36 patients with metastatic esophagogastric cancer were accrued to this single-center phase II study (NCT01913639). The most common grade 3-4 treatment-related adverse events were neutropenia (36%), leucopenia (11%) and hypertension (8%). The 6-month PFS was 53% (95% confidence interval [CI], 38%-71%), the objective response rate was 54% (95% CI, 37%-70%), and the disease control rate was 77% (95% CI, 67%-94%). Next-generation sequencing did not identify any genomic alterations significantly correlated with response, and there was no association between homologous recombination deficiency and PFS with platinum-based chemotherapy., Conclusion: Regorafenib (one week on-one week off schedule) is well tolerated in combination with first-line FOLFOX but does not improve 6-month PFS relative to historical control., Implications for Practice: Prognosis for metastatic esophagogastric cancer remains poor despite modern systemic therapy regimens. This phase II trial indicates that the combination of regorafenib and FOLFOX is well tolerated but does not add to the efficacy of first-line chemotherapy in metastatic esophagogastric cancer. Notably, recently reported data suggest potential synergy between regorafenib and the PD-1 inhibitor nivolumab. As this study demonstrates that regorafenib plus FOLFOX is safe, and combined chemotherapy and immunotherapy show favorable toxicity profiles, future studies combining immunotherapy with regorafenib and chemotherapy may be feasible., (© AlphaMed Press 2019.)

Intricate systems of checkpoints such as the programmed cell death protein 1 (PD-1)/programmed death ligand 1 (PD-L1) axis regulate adaptive immune responses to protect against tissue damage. However, diverse cancers can exploit these pathways to evade or suppress antitumor immunity, leading to tumor progression. Correspondingly, immune checkpoint inhibitors that block PD-1/PD-L1 signaling have shown marked therapeutic efficacy in certain cancers, such as Hodgkin lymphoma. Reed-Sternberg cells, the hallmark cells of Hodgkin lymphoma, commonly overexpress PD-1 ligands, and recent clinical trials have demonstrated impressive response rates with the PD-1 inhibitors nivolumab and pembrolizumab in relapsed or refractory Hodgkin lymphoma, leading to their FDA approval in this setting. Current efforts are underway to improve clinical responses by incorporating PD-1 inhibitors into earlier treatment regimens and identifying therapeutic agents that synergize with PD-1 inhibitors. This review summarizes our understanding of the PD-1/PD-L1 axis in Hodgkin lymphoma, recent clinical studies of anti-PD-1 monotherapy and promising combination immunotherapy in the pipeline., (Copyright © 2018 the Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the European Hematology Association.)

Graft-versus-host disease (GVHD) is a major cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Lymphocyte trafficking via chemokine receptors such as CCR5 plays a critical role in alloreactive responses, and previous data suggest that CCR5 blockade with maraviroc results in a low incidence of visceral GVHD. However, the full scope of clinical and immunologic effects of CCR5 blockade in HSCT has not been described. We compared a cohort of patients enrolled on a trial of reduced-intensity allo-HSCT with standard GVHD prophylaxis plus maraviroc to a contemporary control cohort receiving standard GVHD prophylaxis alone. Maraviroc treatment was associated with a lower incidence of acute GVHD without increased risk of disease relapse, as well as reduced levels of gut-specific markers. At day 30, maraviroc treatment increased CCR5 expression on T cells and dampened T-cell activation in peripheral blood without impairing early immune reconstitution or increasing risk for infections. Patients who developed acute GVHD despite maraviroc prophylaxis showed increased T-cell activation, naive T-cell skewing, and elevated serum CXCL9 and CXCL10 levels. Collectively, these data suggest that maraviroc effectively protects against GVHD by modulating alloreactive donor T-cell responses, and that CXCR3 signaling may be an important resistance mechanism to CCR5 blockade in GVHD., (© 2017 by The American Society of Hematology.)

RNA degradation is tightly regulated to selectively target aberrant RNAs, including viral RNA, but this regulation is incompletely understood. Through RNAi screening in Drosophila cells, we identified the 3'-to-5' RNA exosome and two components of the exosome cofactor TRAMP (Trf4/5-Air1/2-Mtr4 polyadenylation) complex, dMtr4 and dZcchc7, as antiviral against a panel of RNA viruses. We extended our studies to human orthologs and found that the exosome as well as TRAMP components hMTR4 and hZCCHC7 are antiviral. While hMTR4 and hZCCHC7 are normally nuclear, infection by cytoplasmic RNA viruses induces their export, forming a cytoplasmic complex that specifically recognizes and induces degradation of viral mRNAs. Furthermore, the 3' untranslated region (UTR) of bunyaviral mRNA is sufficient to confer virus-induced exosomal degradation. Altogether, our results reveal that signals from viral infection repurpose TRAMP components to a cytoplasmic surveillance role where they selectively engage viral RNAs for degradation to restrict a broad range of viruses., (© 2016 Molleston et al.; Published by Cold Spring Harbor Laboratory Press.)

Innate lymphoid cells (ILCs) are critical for maintaining epithelial barrier integrity at mucosal surfaces; however, the tissue-specific factors that regulate ILC responses remain poorly characterized. Using mice with intestinal epithelial cell (IEC)-specific deletions in either inhibitor of κB kinase (IKK)α or IKKβ, two critical regulators of NFκB activation, we demonstrate that IEC-intrinsic IKKα expression selectively regulates group 3 ILC (ILC3)-dependent antibacterial immunity in the intestine. Although IKKβ(ΔIEC) mice efficiently controlled Citrobacter rodentium infection, IKKα(ΔIEC) mice exhibited severe intestinal inflammation, increased bacterial dissemination to peripheral organs, and increased host mortality. Consistent with weakened innate immunity to C. rodentium, IKKα(ΔIEC) mice displayed impaired IL-22 production by RORγt(+) ILC3s, and therapeutic delivery of rIL-22 or transfer of sort-purified IL-22-competent ILCs from control mice could protect IKKα(ΔIEC) mice from C. rodentium-induced morbidity. Defective ILC3 responses in IKKα(ΔIEC) mice were associated with overproduction of thymic stromal lymphopoietin (TSLP) by IECs, which negatively regulated IL-22 production by ILC3s and impaired innate immunity to C. rodentium. IEC-intrinsic IKKα expression was similarly critical for regulation of intestinal inflammation after chemically induced intestinal damage and colitis. Collectively, these data identify a previously unrecognized role for epithelial cell-intrinsic IKKα expression and TSLP in regulating ILC3 responses required to maintain intestinal barrier immunity., (© 2015 Giacomin et al.)

DEAD-box helicases play essential roles in RNA metabolism across species, but emerging data suggest that they have additional functions in immunity. Through RNAi screening, we identify an evolutionarily conserved and interferon-independent role for the DEAD-box helicase DDX17 in restricting Rift Valley fever virus (RVFV), a mosquito-transmitted virus in the bunyavirus family that causes severe morbidity and mortality in humans and livestock. Loss of Drosophila DDX17 (Rm62) in cells and flies enhanced RVFV infection. Similarly, depletion of DDX17 but not the related helicase DDX5 increased RVFV replication in human cells. Using crosslinking immunoprecipitation high-throughput sequencing (CLIP-seq), we show that DDX17 binds the stem loops of host pri-miRNA to facilitate their processing and also an essential stem loop in bunyaviral RNA to restrict infection. Thus, DDX17 has dual roles in the recognition of stem loops: in the nucleus for endogenous microRNA (miRNA) biogenesis and in the cytoplasm for surveillance against structured non-self-elements., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Autophagy has been implicated as a component of host defense, but the significance of antimicrobial autophagy in vivo and the mechanism by which it is regulated during infection are poorly defined. Here we found that antiviral autophagy was conserved in flies and mammals during infection with Rift Valley fever virus (RVFV), a mosquito-borne virus that causes disease in humans and livestock. In Drosophila, Toll-7 limited RVFV replication and mortality through activation of autophagy. RVFV infection also elicited autophagy in mouse and human cells, and viral replication was increased in the absence of autophagy genes. The mammalian Toll-like receptor adaptor, MyD88, was required for anti-RVFV autophagy, revealing an evolutionarily conserved requirement for pattern-recognition receptors in antiviral autophagy. Pharmacologic activation of autophagy inhibited RVFV infection in mammalian cells, including primary hepatocytes and neurons. Thus, autophagy modulation might be an effective strategy for treating RVFV infection, which lacks approved vaccines and therapeutics., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Autophagy is a highly conserved degradative pathway that has rapidly emerged as a critical component of immunity and host defense. Studies have implicated autophagy genes in restricting the replication of a diverse array of pathogens, including bacteria, viruses and protozoans. However, in most cases, the in vivo role of antimicrobial autophagy against pathogens has been undefined. Drosophila provides a genetically tractable model system that can be easily adapted to study autophagy in innate immunity, and recent studies in flies have demonstrated that autophagy is an essential antimicrobial response against bacteria and viruses in vivo. These findings reveal striking conservation of antimicrobial autophagy between flies and mammals, and in particular, the role of pathogen-associated pattern recognition in triggering this response. This review discusses our current understanding of antimicrobial autophagy in Drosophila and its potential relevance to human immunity., (Copyright © 2013 S. Karger AG, Basel.)

Innate immunity is highly conserved and relies on pattern recognition receptors (PRRs) such as Toll-like receptors (identified through their homology to Drosophila Toll) for pathogen recognition. Although Drosophila Toll is vital for immune recognition and defense, roles for the other eight Drosophila Tolls in immunity have remained elusive. Here we have shown that Toll-7 is a PRR both in vitro and in adult flies; loss of Toll-7 led to increased vesicular stomatitis virus (VSV) replication and mortality. Toll-7, along with additional uncharacterized Drosophila Tolls, was transcriptionally induced by VSV infection. Furthermore, Toll-7 interacted with VSV at the plasma membrane and induced antiviral autophagy independently of the canonical Toll signaling pathway. These data uncover an evolutionarily conserved role for a second Drosophila Toll receptor that links viral recognition to autophagy and defense and suggest that other Drosophila Tolls may restrict specific as yet untested pathogens, perhaps via noncanonical signaling pathways., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Background: Structured noncoding RNAs perform many functions that are essential for protein synthesis, RNA processing, and gene regulation. Structured RNAs can be detected by comparative genomics, in which homologous sequences are identified and inspected for mutations that conserve RNA secondary structure., Results: By applying a comparative genomics-based approach to genome and metagenome sequences from bacteria and archaea, we identified 104 candidate structured RNAs and inferred putative functions for many of these. Twelve candidate metabolite-binding RNAs were identified, three of which were validated, including one reported herein that binds the coenzyme S-adenosylmethionine. Newly identified cis-regulatory RNAs are implicated in photosynthesis or nitrogen regulation in cyanobacteria, purine and one-carbon metabolism, stomach infection by Helicobacter, and many other physiological processes. A candidate riboswitch termed crcB is represented in both bacteria and archaea. Another RNA motif may control gene expression from 3'-untranslated regions of mRNAs, which is unusual for bacteria. Many noncoding RNAs that likely act in trans are also revealed, and several of the noncoding RNA candidates are found mostly or exclusively in metagenome DNA sequences., Conclusions: This work greatly expands the variety of highly structured noncoding RNAs known to exist in bacteria and archaea and provides a starting point for biochemical and genetic studies needed to validate their biologic functions. Given the sustained rate of RNA discovery over several similar projects, we expect that far more structured RNAs remain to be discovered from bacterial and archaeal organisms.

Cyclic di-guanosine monophosphate (di-GMP) is a circular RNA dinucleotide that functions as a second messenger in diverse species of bacteria to trigger wide-ranging physiological changes, including cell differentiation, conversion between motile and biofilm lifestyles, and virulence gene expression. However, the mechanisms by which cyclic di-GMP regulates gene expression have remained a mystery. We found that cyclic di-GMP in many bacterial species is sensed by a riboswitch class in messenger RNA that controls the expression of genes involved in numerous fundamental cellular processes. A variety of cyclic di-GMP regulons are revealed, including some riboswitches associated with virulence gene expression, pilus formation, and flagellum biosynthesis. In addition, sequences matching the consensus for cyclic di-GMP riboswitches are present in the genome of a bacteriophage.

We have identified a highly conserved RNA motif located upstream of genes encoding molybdate transporters, molybdenum cofactor (Moco) biosynthesis enzymes, and proteins that utilize Moco as a coenzyme. Bioinformatics searches have identified 176 representatives in gamma-Proteobacteria, delta-Proteobacteria, Clostridia, Actinobacteria, Deinococcus-Thermus species and DNAs from environmental samples. Using genetic assays, we demonstrate that a Moco RNA in Escherichia coli associated with the Moco biosynthetic operon controls gene expression in response to Moco production. In addition, we provide evidence indicating that this conserved RNA discriminates against closely related analogues of Moco. These results, together with extensive phylogenetic conservation and typical gene control structures near some examples, indicate that representatives of this structured RNA represent a novel class of riboswitches that sense Moco. Furthermore, we identify variants of this RNA that are likely to be triggered by the related tungsten cofactor (Tuco), which carries tungsten in place of molybdenum as the metal constituent.

Written examinations are widely used for assessment in clinical clerkships and for licensure and specialty board certification, as opposed to assessment based on actual performance with patients. This reliance on written examinations is due to their ease of use and perceived objectivity and occurs despite the fact that the examinations assess few components of clinical competence. Simulated patients can standardize the presentation of a patient problem; and, if the patients are employed in an assessment in a manner parallel to the design of written test items, the assessment can have an objectivity similar to that enjoyed by written tests. Such an assessment allows the major components of clinical competence to be tested. The results and feasibility of using simulated patients in a multiple-station assessment of an entire senior class in January 1986 are described. A second assessment was administered to a different senior class in December 1986. This latter assessment was designed in collaboration with another medical school that administered the same assessment to its senior students in March 1987.