Heterogeneity of neutrophils in cancer: one size does not fit all.

Neutrophils play an essential role in the defense against bacterial infections and orchestrate both the innate and adaptive immune responses. With their abundant numbers, diverse function and short life span, these cells are at the forefront of immune responses, and have gained attention in recent years because of their presence in tumor sites. Neutrophil involvement pertains to tumor cells' ability to construct a suitable tumor microenvironment (TME) that accelerates their own growth and malignancy, by facilitating their interaction with surrounding cells through the circulatory and lymphatic systems, thereby influencing tumor development and progression. Studies have indicated both pro- and anti-tumor properties of infiltrating neutrophils. The TME can exploit neutrophil function, recruitment, and even production, thus resulting in pro-tumor properties of neutrophils, including promotion of genetic instability, tumor cell proliferation, angiogenesis and suppression of anti-tumor or inflammatory response. In contrast, neutrophils can mediate anti-tumor resistance by direct cytotoxicity to the tumor cells or by facilitating anti-tumor functions via crosstalk with T cells. Here, we summarize current knowledge regarding the effects of neutrophil heterogeneity under homeostatic and tumor conditions, including neutrophil phenotype and function, in cancer biology.

Broadband Plasmonic NbN Photocatalysts for Enhanced Hydrogen Generation from Ammonia Borane under Visible-Near-Infrared Illumination.

The superior light-harvesting ability of plasmonic metallic nanostructures makes them uniquely suitable for applications in the light-driven chemical transformations relevant to renewable fuels. Here we demonstrate the use of niobium nitride (NbN) nanostructures as a nonprecious plasmonic photocatalyst for the highly efficient H2 generation from the hydrolytic decomposition of ammonia borane (AB). Porous nanostructured NbN with a hierarchical flower-like nanoarchitecture was synthesized to achieve strong broadband plasmonic absorption in the visible and near-infrared (NIR) regions. The plasmonic NbN absorbers, when loaded with an optimized amount (∼2 wt %) of nanoparticulate Ni as the catalytic centers, show notably enhanced activity toward AB decomposition for H2 evolution under both visible and NIR illumination, with the reaction rates being 4.6 (>420 nm) and 2.7 (>780 nm) times higher than that of the dark reaction. Further kinetic measurements and mechanistic investigations reveal that the photocatalytic activity originates from the plasmonic hot-carrier contributions.

Based on the Network Pharmacology to Investigate the Mechanism of Qingjie Fuzheng Granules against Colorectal Cancer.

Qingjie Fuzheng granules (QFG) exert an anticancer effect against colorectal cancers (CRC). However, the pharmacological molecular mechanisms are still unclear. This study was aimed to establish a simple method to predict targets of QFG against CRC by the network pharmacology strategy. 461 compounds and 1559 targets in QFG were enriched by BATMAN-TCM. 21 of the common targets were obtained by the groups of "Jun," "Chen," "Zuo," and "Shi" medicine in QFG. The enrichment analyses of GO functional terms, KEGG pathway, and OMIM/TTD diseases displayed the targets in the different and complementary effects of four functional medicines in QFG. Then, 613 differential targets for QFG in CRC were identified. GO functional terms and KEGG pathway analyses showed that QFG regulated the inflammatory function and lipid metabolic process. There were also targets that played a role in the binding to the receptors in membranes, in the activation of the transportation signal, and provided pain relief by regulation of the neural related pathways. Next, the protein-protein interaction network was analyzed, and the levels of the predicted targets in CRC primary tumor were explored, and 7 candidate targets of QFG against CRC were obtained. Furthermore, with real-time PCR and enzyme-linked immunosorbent assay (ELISA) analysis, downregulation of dopamine D2 receptor (DRD2) and interleukin-6 (IL-6), and upregulation of interleukin-10 (IL-10) were identified following the treatment of QFG. At last, the survival and prognosis of the potential targets of QFG in CRC patients were analyzed by GenomicScape, and IL-6 was suggested to be an index for the regulation of QFG in CRC. These results might elucidate the possible antitumor mechanism of QFG and highlight the candidate therapeutic targets and the application direction in clinical treatment for QFG.

Absorbable suture anchor and knotless anchor techniques produced similar outcomes in arthroscopic anterior talofibular ligament repair.

PURPOSE: The purpose of this study is to compare absorbable suture anchor with knotless anchor techniques for arthroscopic anterior talofibular ligament (ATFL) repair. METHOD: A multicenter retrospective study was performed with 185 patients, who had undergone an arthroscopic ATFL repair procedure using absorbable suture anchor or knotless anchor between May 2017 and October 2019. The follow-up time was a minimum of 18 months. Karlsson-Peterson score, visual analogue scale (VAS), and Cumberland ankle instability tool (CAIT) were evaluated. The complications were also recorded. RESULTS: One hundred and seven patients underwent one absorbable suture anchor repair procedure (Group A [A]), and the other seventy-eight patients underwent one knotless anchor repair procedure (Group B [B]). At the final follow-up, both Karlsson-Peterson score (A, pre 61.0 ± 8.0 vs post 93.5 ± 5.3, P < 0.001; B, pre 59.5 ± 8.2 vs post 92.4 ± 6.3, P < 0.001), VAS score (A, pre 5.0 ± 1.3 vs post 0.5 ± 0.7, P < 0.001; B, pre 5.5 ± 1.2 vs post 0.9 ± 1.0, P < 0.001), and CAIT score (A, pre 53.1 ± 12.0 vs post 93.1 ± 6.6, P < 0.001; B, pre 51.6 ± 12.0 vs post 93.1 ± 6.5, P < 0.001) improved significantly in both groups. There was no significant difference between the two groups regarding the Karlsson-Peterson score (A, pre 61.0 ± 8.0 vs B, pre 59.5 ± 8.2, n.s; A, post 93.5 ± 5.3 vs B, post 92.4 ± 6.3, n.s), CAIT score (A, pre 53.1 ± 12.0 vs B, pre 51.6 ± 12.0, n.s; A, post 93.1 ± 6.6 vs B, post 93.1 ± 6.5, n.s) and the change ranges of VAS (A, 4.5 ± 1.0 vs B, 4.6 ± 1.2, n.s). Anchor complications were easier to occur in Group B (0/107 vs 6/78, P = 0.007). Knot irritation slightly increased in Group A (10/107 vs 0/78, P = 0.006). No significant difference was found regarding total complication rates (A, 10/107 vs B, 6/78, n.s). CONCLUSION: Absorbable suture anchor and knotless anchor for arthroscopic ATFL repair produced similar clinical outcomes. The ankle stability scores increased significantly in both groups. However, the knotless anchor has a higher risk to loosen, deviated direction or break, while the absorbable suture anchor still has a slim chance of knot irritation. LEVEL OF EVIDENCE: III.

Identification of mini-chromosome maintenance 8 as a potential prognostic marker and its effects on proliferation and apoptosis in gastric cancer.

Mini-chromosome maintenance (MCM) proteins play important roles in initiating eukaryotic genome replication. The MCM family of proteins includes several members associated with the development and progression of certain cancers. We performed online data mining to assess the expression of MCMs in gastric cancer (GC) and the correlation between their expression and survival in patients with GC. Notably, MCM8 expression was undoubtedly up-regulated in GC, and higher expression correlated with shorter overall survival (OS) and progression-free survival (PFS) in patients with GC. However, the role of MCM8 in GC has not been previously explored. Our in vitro experiments revealed that MCM8 knockdown inhibited cell growth and metastasis. Moreover, MCM8 knockdown induced apoptosis. Mechanistically, the expression levels of Bax and cleaved caspase-3 were increased, whereas Bcl-2 expression decreased. Additionally, we demonstrated that MCM8 knockdown suppressed tumorigenesis in vivo. Overall, these results suggest that MCM8 plays a significant role in GC progression.

Recurrent GNAQ mutation encoding T96S in natural killer/T cell lymphoma.

Natural killer/T cell lymphoma (NKTCL) is a rare and aggressive malignancy with a higher prevalence in Asia and South America. However, the molecular genetic mechanisms underlying NKTCL remain unclear. Here, we identify somatic mutations of GNAQ (encoding the T96S alteration of Gαq protein) in 8.7% (11/127) of NKTCL patients, through whole-exome/targeted deep sequencing. Using conditional knockout mice (Ncr1-Cre-Gnaqfl/fl), we demonstrate that Gαq deficiency leads to enhanced NK cell survival. We also find that Gαq suppresses tumor growth of NKTCL via inhibition of the AKT and MAPK signaling pathways. Moreover, the Gαq T96S mutant may act in a dominant negative manner to promote tumor growth in NKTCL. Clinically, patients with GNAQ T96S mutations have inferior survival. Taken together, we identify recurrent somatic GNAQ T96S mutations that may contribute to the pathogenesis of NKTCL. Our work thus has implications for refining our understanding of the genetic mechanisms of NKTCL and for the development of therapies.

Improved Electrochemical Performance Based on Nanostructured SnS2@CoS2-rGO Composite Anode for Sodium-Ion Batteries.

A promising anode material composed of SnS2@CoS2 flower-like spheres assembled from SnS2 nanosheets and CoS2 nanoparticles accompanied by reduced graphene oxide (rGO) was fabricated by a facile hydrothermal pathway. The presence of rGO and the combined merits of SnS2 and CoS2 endow the SnS2@CoS2-rGO composite with high conductivity pathways and channels for electrons and with excellent properties as an anode material for sodium-ion batteries (SIBs). A high capacity of 514.0 mAh g-1 at a current density of 200 mA g-1 after 100 cycles and a good rate capability can be delivered. The defined structure and good sodium-storage performance of the SnS2@CoS2-rGO composite demonstrate its promising application in high-performance SIBs.

Platelet-derived growth factor receptor alpha (PDGFRα) is overexpressed in NK/T-cell lymphoma and mediates cell survival.

Nasal-type natural killer/T-cell lymphoma (NKTCL) is a subtype of non-Hodgkin lymphoma (NHL) that is clinically aggressive and has a poor prognosis. Platelet-derived growth factor receptors (PDGFRs) and their ligands (PDGFs) play important roles in angiogenesis, cancer cell proliferation, survival, migration and poor prognosis in various tumours. However, the significance of PDGFRs in NKTCL remains unknown. Herein, the present study aimed to investigate the important role of PDGFRα in pathogenesis, progression and prognisis of NKTCL. Firstly, we performed immunohistochemical staining, qRT-PCR and western blotting to determine PDGFRα expression in formalin-fixed, paraffin-embedded tissue sections from 78 NKTCL cases and in cell lines. Secondly, correlations between PDGFRα expression and NKTCL clinical parameters and prognosis were analysed. Moreover, a biological assessment of PDGFRα blockade in two NKTCL cell lines was conducted through proliferation assay, cell-cycle evaluation and apoptosis detection by flow cytometry analyses. Furthermore, we detected in vivo activity of imatinib in mouse model of NKTCL. We found that the expression of PDGFRα was significantly higher in NKTCL tissues compared to the reactive lymphoid hyperplasia of the nasopharynx (P = 0.028). High PDGFRα expression was strongly associated with a high LDH level (P = 0.028) and III-IV stage (P = 0.013). NKTCL patients with high PDGFRα expression displayed a reduced median overall survival time and progression-free survival time when compared with those with low PDGFRα expression (P = 0.011, P = 0.005, respectively). Cox multivariate analysis showed that III-IV stage (P = 0.024) and high PDGFRα expression (P = 0.003) were independent prognostic factors in NKTCL patients. Biological assessment assays in two NKTCL cell lines revealed that a specific PDGFR antagonist, imatinib, inhibited cell viability, blocked cell cycle progression at G0/G1 stage and induced apoptosis. Similarly, the in vivo assay showed that imatinib delayed mouse model tumour growth. In conclusion, NKTCL tumour cells have prominent PDGFRα expression, which can serve as a candidate prognostic marker. PDGFR antagonists have significant biological effect on NKTCL and may be useful therapeutic agents for treatment of NKTCL.

Function of FEZF1 during early neural differentiation of human embryonic stem cells.

The understanding of the mechanism underlying human neural development has been hampered due to lack of a cellular system and complicated ethical issues. Human embryonic stem cells (hESCs) provide an invaluable model for dissecting human development because of unlimited self-renewal and the capacity to differentiate into nearly all cell types in the human body. In this study, using a chemical defined neural induction protocol and molecular profiling, we identified Fez family zinc finger 1 (FEZF1) as a potential regulator of early human neural development. FEZF1 is rapidly up-regulated during neural differentiation in hESCs and expressed before PAX6, a well-established marker of early human neural induction. We generated FEZF1-knockout H1 hESC lines using CRISPR-CAS9 technology and found that depletion of FEZF1 abrogates neural differentiation of hESCs. Moreover, loss of FEZF1 impairs the pluripotency exit of hESCs during neural specification, which partially explains the neural induction defect caused by FEZF1 deletion. However, enforced expression of FEZF1 itself fails to drive neural differentiation in hESCs, suggesting that FEZF1 is necessary but not sufficient for neural differentiation from hESCs. Taken together, our findings identify one of the earliest regulators expressed upon neural induction and provide insight into early neural development in human.

Pretreatment 14-3-3 epsilon level is predictive for advanced extranodal NK/T cell lymphoma therapeutic response to asparaginase-based chemotherapy.

PURPOSE: The aim of the present study was to identify the potential relevant biomarkers to predict the therapeutic response of advanced extranodal natural killer/T cell lymphoma(ENKTL) treated with asparaginase-based treatment. EXPERIMENTAL DESIGN: Proteomic technology is used to identify differentially expressed proteins between chemotherapy-resistant and chemotherapy-sensitive patients. Then enzyme-linked immunosorbent assay is used to validate the predictive value of selective biomarkers. RESULTS: A total of 61 upregulated and 22 downregulated proteins are identified in chemotherapy-resistant patients compared with chemotherapy-sensitive patients. Furthermore, they validated that pretreatment high level 14-3-3 epsilon(ε)(≥61.95 ng/mL, 84.0 and 95.2% for sensitivity and specificity, respectively) is associated with poor 2-year overall survival (OS) (5.3 vs 68.8%, p<0.0001) and PFS (4.5 vs 76.9%, p<0.0001). In multivariate survival analysis, pretreatment high level 14-3-3 epsilon significantly is correlated with both inferior OS (p = 0.033) and PFS (p = 0.005). CONCLUSION AND CLINICAL RELEVANCE: These findings indicate that pretreatment high level 14-3-3 epsilon is an independent predictor of chemotherapy-resistance and poor prognosis for patients with advanced ENKTL in the era of asparaginase.

[Lipopolysaccharide promotes the proliferation of CD4(+) T cells by modulating the survive and cytokine secretion of dendritic cells].

Objective To explore the mechanism modulating the function of dendritic cells (DCs) and promoting the T cell response by lipopolysaccharide (LPS). Methods Splenic DCs were purified with anti-CD11c immunomagnetic beads. After DCs were stimulated with LPS, the expressions of co-stimulatory molecules CD80 and CD86 on the DCs were detected by flow cytometry. The protein levels of pro-inflammatory cytokines interleukin 4 (IL-4), IL-5, IL-6, IL-12p40, IL-12p70 and tumor necrosis factor alpha (TNF-α) in the culture supernatant were measured by ELISA. The apoptotic levels of DCs which were labeled with annexinV-FITC/PI were determined by flow cytometry. The phosphorylation level of nuclear factor κB P65 (NF-κB P65) was assessed by phos-flow. The mRNA levels of variable genes in microarray were determined by real-time PCR. The proliferation of CD4(+) T cells which were co-cultured with OVA323-329-treated DCs was analyzed by flow cytometry. Results The purity of DCs reached over 93% after isolation. LPS up-regulated the expressions of CD80 and CD86 and enhanced DCs-mediated proliferation of CD4(+) T cells. In addition, LPS increased the protein levels of IL-12p40, TNF-α and IL-6, and inhibited the apoptosis of DCs through the NF-κB signaling pathway. Conclusion LPS could enhance DC-mediated proliferation of CD4(+) T cells by modulating the DCs survival and cytokine secretion.

S100A9 and ORM1 serve as predictors of therapeutic response and prognostic factors in advanced extranodal NK/T cell lymphoma patients treated with pegaspargase/gemcitabine.

Pegaspargase combined with gemcitabine have greatly improved the outcomes of advanced extranodal NK/T cell lymphoma (ENKL). However, patients frequently undergo recurrent disease due to chemoresistance, and few predictive parameters are available. The present study explored potential biomarkers to predict the therapeutic response of advanced ENKL treated with pegaspargase/gemcitabine and evaluate the prognostic significance. Through serum proteomic analysis, we identified 61 upregulated and 22 downregulated proteins in nonresponders compared with responders. We further validated that patients with unfavourable treatment outcomes displayed higher levels of S100A9 and ORM1 via enzyme-linked immunosorbent assay (ELISA). Moreover, the sensitivity and specificity for detecting refractory patients were 81.5% and 71.4% for S100A9 > 62 ng/ml, 85.2% and 77.1% for ORM1 > 1436 ug/ml, 100% and 57.1% for S100A9 combined with ORM1. Furthermore, in multivariate analysis elevated levels of S100A9 were associated with poor 2-year OS (40.2% vs. 76.6%, RR = 2.92, p = 0.005) and 2-year PFS (33.1% vs. 61.1%, RR = 2.61 p = 0.011). High ORM1 also predicted inferior 2-year OS (38.7% vs.76.1, RR = 2.46, p = 0.023) and 2-year PFS (18.4% vs. 73.2%, RR = 2.86, p = 0.009). Our results indicated that S100A9 and ORM1 could serve as reliable predictors of therapeutic response and independent prognostic factors of survival in advanced ENKL patients treated with pegaspargase/gemcitabine.

The over-expression of FGFR4 could influence the features of gastric cancer cells and inhibit the efficacy of PD173074 and 5-fluorouracil towards gastric cancer.

The aim was to investigate the function of fibroblast growth factor receptor 4 (FGFR4) in gastric cancer (GC) and explore the treatment value of agent targeted to FGFR4. Function assays in vitro and in vivo were performed to investigate the discrepancy of biological features among the GC cells with different expression of FGFR4. GC cells were treated with the single and combination of PD173074 (PD, an inhibitor of FGFR4) and 5-fluorouracil (5-Fu). The invasion ability were stronger, and the apoptosis rates were lower in MGC803 and BGC823 cells treated with FGFR4-LV5 (over-expression of FGFR4 protein) (P < 0.05). The proliferation ability of GC cells is reduced when treated by the single and combination of 5-Fu and PD while that of the FGFR4-LV5 group was less inhibited compared with control group (P < 0.05). The apoptosis rates are remarkably increased in GC cells treated with the single and combination of 5-Fu and PD (P < 0.05). However, the apoptosis rate obviously is reduced in GC cells treated with FGFR4-LV5 compared with control group (P < 0.05). The expression of PCNA and Bcl-XL is remarkably decreased, and the expression of Caspase-3 and cleaved Caspase-3 is obviously increased in GC cells treated with the single and combination of 5-Fu and PD. The tumor volumes of nude mice in FGFR4-LV5 group were much more increased (P < 0.05). The over-expression of FGFR4 enhanced the proliferation ability of GC in vitro and in vivo. The combination of 5-Fu and PD exerted synergetic effect in weakening the proliferation ability and promoting apoptosis in GC cells, while the over-expression of FGFR4 might inhibit the efficacy of two drugs.

MSX2 mediates entry of human pluripotent stem cells into mesendoderm by simultaneously suppressing SOX2 and activating NODAL signaling.

How BMP signaling integrates into and destabilizes the pluripotency circuitry of human pluripotent stem cells (hPSCs) to initiate differentiation into individual germ layers is a long-standing puzzle. Here we report muscle segment homeobox 2 (MSX2), a homeobox transcription factor of msh family, as a direct target gene of BMP signaling and a master mediator of hPSCs' differentiation to mesendoderm. Enforced expression of MSX2 suffices to abolish pluripotency and induce directed mesendoderm differentiation of hPSCs, while MSX2 depletion impairs mesendoderm induction. MSX2 is a direct target gene of the BMP pathway in hPSCs, and can be synergistically activated by Wnt signals via LEF1 during mesendoderm induction. Furthermore, MSX2 destabilizes the pluripotency circuitry through direct binding to the SOX2 promoter and repression of SOX2 transcription, while MSX2 controls mesendoderm lineage commitment by simultaneous suppression of SOX2 and induction of NODAL expression through direct binding and activation of the Nodal promoter. Interestingly, SOX2 can promote the degradation of MSX2 protein, suggesting a mutual antagonism between the two lineage-specifying factors in the control of stem cell fate. Together, our findings reveal crucial new mechanisms of destabilizing pluripotency and directing lineage commitment in hPSCs.

Evaluation of bone marrow involvement in extranodal NK/T cell lymphoma by FDG-PET/CT.

Evaluation of bone marrow involvement (BMI) by conventional bone marrow biopsy (BMB) can generate false-negative results if marrow disease is focal. The sensitivity of 18F-2-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (FDG-PET/CT) in assessing BMI in extranodal NK/T cell lymphoma (ENKL) has not been determined. We retrospectively collected clinical data from a series of 55 patients with newly diagnosed ENKL, who have received both FDG-PET/CT and BMB prior to treatment. BMB results were used as reference standard. Twelve patients (21.8 %) were considered positive lymphomatous infiltration by FDG-PET/CT (PET-CT/BM+), and five patients (9 %) were identified positive by BMB (BMB/BM+). There was a discordant result in seven patients who were PET-CT/BM+ but BMB/BM-. The sensitivity and specificity of FDG-PET/CT for identifying BMI were 100 and 86 %, respectively. Then, we analyzed the overall survival (OS) and progression-free survival (PFS) of patients who were PET-CT/BM+ and PET-CT/BM-. The median follow-up time was 16 months (range, 3 to 43 months). PET-CT/BM+ patients possessed worse 2-year OS than PET-CT/BM- patients (84.8 vs 67.9 %, P < 0.05). The estimated 2-year PFS for PET-CT/BM- and PET-CT/BM+ patients were 72.7 and 41.9 % (P < 0.05), respectively. However, it was hard to conclude that patients who were PET-CT/BM+ had similar survivals to advanced-stage patients due to the low number of patients who were PET-CT/BM+. In conclusion, FDG-PET/CT can complementally detect positive BMI patients missed by BMB in ENKL. The utility of FDG-PET/CT for defining bone marrow status has important prognostic value.

Pre-operative TNM staging of primary colorectal cancer by (18)F-FDG PET-CT or PET: a meta-analysis including 2283 patients.

The aim of the present study was to perform a meta-analysis to assess the diagnostic value of fluorine-18 fluorodeoxyglucose ((18)F-FDG) PET-CT/PET in the pre-operative evaluation of TNM staging in patients with primary colorectal cancer (CRC). The Medline, Embase and Web of Knowledge were searched for studies assessing the diagnostic value of (18)F-FDG PET-CT/PET in the pre-operative evaluation of TNM staging in CRC patients. We pooled the sensitivity, specificity, positive and negative Likelihood ratio (LR+ and LR-) and Diagnostic Odds Ratio (DOR) and constructed summary receiver operating characteristic curves. A total of 28 studies including 2283 CRC patients were analyzed. The pre-operative tumor detecting rate of PET-CT was 95.35%, which was superior to CT (P < 0.05). The pooled sensitivity and specificity of pre-operative T staging by PET-CT/PET was 0.73 (95% CI: 0.65-0.81) and 0.99 (95% CI: 0.98-0.99), which the AUC and Q* were 0.96 and 0.91, respectively. Concerning pre-operative N staging, the pooled sensitivity and specificity of PET-CT/PET were 0.62 and 0.70, which the AUC and Q* were 0.76 and 0.70, respectively. As for M staging, the pooled sensitivity and specificity of PET-CT/PET were 0.91 (95% CI: 0.80-0.96) and 0.95 (95% CI: 0.91-0.98), which the AUC and Q* were 0.96 and 0.91, respectively. (18)F-FDG PET-CT/PET had good performance in the pre-operative tumor detecting rate, T staging and M staging in patients with primary CRC, which might alter the therapeutic strategy. However, the diagnostic value of (18)F-FDG PET-CT/PET in pre-operative N staging in CRC patients was not ideal.

Effectiveness of gemcitabine, pegaspargase, cisplatin, and dexamethasone (DDGP) combination chemotherapy in the treatment of relapsed/refractory extranodal NK/T cell lymphoma: a retrospective study of 17 patients.

The prognosis of extranodal nature killer (NK)/T cell lymphoma (ENKL) is dismal because of its aggressive course and multidrug resistance. Currently, for patients with relapsed/refractory ENKL, L-asparaginase-based regimens such as L-asparaginase, ifosfamide, methotrexate, etoposide, and dexamethasone (SMILE) or L-asparaginase, methotrexate, and dexamethasone (AspaMetDex) are recommended. We retrospectively investigated the efficacy and safety of gemcitabine, pegaspargase, cisplatin, and dexamethasone (DDGP) combination chemotherapy in the treatment of 17 relapsed/refractory ENKL patients. Clinical data from these patients were collected and analyzed. The primary end point was overall response rate (ORR). All patients were subjected to 2 to 6 cycles of DDGP chemotherapy, and the median number of cycles of DDGP regimen administrated was four. The ORR was 88.2 % (15/17), with nine patients (52.9 %) achieved complete response (CR) and six patients (35.3 %) achieved partial response (PR). The median follow-up time was 17 months (range 2-28 months). The 1-year overall survival (OS) rate and 1-year progression-free survival (PFS) were 82.4 and 64.7 %, respectively. For those CR responders, the median PFS was 17 months. Grade 3/4 neutropenia occurred in nine patients (52.9 %) and grade 3/4 thrombocytopenia occurred in six patients (35.3 %). DDGP combination chemotherapy produces favorable outcomes in relapsed/refractory ENKL, and more attention should be paid to treatment-related myelosuppression. Further prospective trials are expected to define the efficacy.