Efficacy and predictive factors of transarterial chemoembolization combined with lenvatinib plus programmed cell death protein-1 inhibition for unresectable hepatocellular carcinoma

BACKGROUND The efficacy and safety of transarterial chemoembolization(TACE)combined with lenvatinib plus programmed cell death protein-1(PD-1)for unresectable hepato-cellular carcinoma(HCC)have rarely been evaluated and it is unknown which factors are related to efficacy.AIM To evaluate the efficacy and independent predictive factors of TACE combined with lenvatinib plus PD-1 inhibitors for unresectable HCC.METHODS This study retrospectively enrolled patients with unresectable HCC who received TACE/lenvatinib/PD-1 treatment between March 2019 and April 2022.Overall survival(OS)and progression-free survival(PFS)were determined.The objective response rate(ORR)and disease control rate(DCR)were evaluated in accordance with the modified Response Evaluation Criteria in Solid Tumors.Additionally,the prognostic factors affecting the clinical outcome were assessed.RESULTS One hundred and two patients were enrolled with a median follow-up duration of 12.63 months.The median OS was 26.43 months(95%CI:17.00-35.87),and the median PFS was 10.07 months(95%CI:8.50-11.65).The ORR and DCR were 61.76%and 81.37%,respectively.The patients with Barcelona Clinic Liver Cancer Classification(BCLC)B stage,early neutrophil-to-lymphocyte ratio(NLR)response(decrease),or early alpha-fetoprotein(AFP)response(decrease>20%)had superior OS and PFS than their counterparts.CONCLUSION This study showed that TACE/lenvatinib/PD-1 treatment was well tolerated with encouraging efficacy in patients with unresectable HCC.The patients with BCLC B-stage disease with early NLR response(decrease)and early AFP response(decrease>20%)may achieve better clinical outcomes with this triple therapy.

Roles of the tumor microenvironment in the resistance to programmed cell death protein 1 inhibitors in patients with gastric cancer

Despite the continuous developments and advancements in the treatment of gastric cancer(GC),which is one of the most prevalent types of cancer in China,the overall survival is still poor for most patients with advanced GC.In recent years,with the progress in tumor immunology research,attention has shifted toward immunotherapy as a therapeutic approach for GC.Programmed cell death protein 1(PD-1)inhibitors,as novel immunosuppressive medications,have been widely utilized in the treatment of GC.However,many patients are still resistant to PD-1 inhibitors and experience recurrence in the advanced stages of PD-1 immunotherapy.To reduce the occurrence of drug resistance and recurrence in GC patients receiving PD-1 immunotherapy,to maximize the clinical activity of immunosuppressive drugs,and to elicit a lasting immune response,it is essential to research the tumor microenvironment mechanisms leading to PD-1 inhibitor resistance in GC patients.This article reviews the progress in studying the factors influencing the resistance to PD-1 inhibitors in the GC tumor microenvironment,aiming to provide insights and a basis for reducing resistance to PD-1 inhibitors for GC patients in the future.

Efficacy of chemotherapy containing bevacizumab in patients with metastatic colorectal cancer according to programmed cell death ligand 1

BACKGROUND Bevacizumab,an anti-vascular endothelial growth factor(VEGF)monoclonal antibody,inhibits angiogenesis and reduces tumor growth.Serum VEGF-C,lactate dehydrogenase,and inflammatory markers have been reported as predictive markers related to bevacizumab treatment.Programmed cell death ligand 1(PD-L1)could act upon VEGF receptor 2 to induce cancer cell angiogenesis and metastasis.AIM To investigate the efficacy of bevacizumab-containing chemotherapy in patients with metastatic colorectal cancer(CRC)according to the expression of PD-L1.METHODS This analysis included CRC patients who received bevacizumab plus FOLFOX or FOLFIRI as first-line therapy between June 24,2014 and February 28,2022,at Samsung Medical Center(Seoul,South Korea).Analysis of patient data included evaluation of PD-L1 expression by the combined positive score(CPS).We analyzed the efficacy of bevacizumab according to PD-L1 expression status in patients with CRC.RESULTS A total of 124 patients was included in this analysis.Almost all patients were treated with bevacizumab plus FOLFIRI or FOLFOX as the first-line chemotherapy.While 77%of patients received FOLFOX,23%received FOLFIRI as backbone first-line chemotherapy.The numbers of patients with a PD-L1 CPS of 1 or more,5 or more,or 10 or more were 105(85%),64(52%),and 32(26%),respectively.The results showed no significant difference in progression-free survival(PFS)and overall survival(OS)with bevacizumab treatment between patients with PDL1 CPS less than 1 and those with PD-L1 CPS of 1 or more(PD-L1<1%vs PD-L1≥1%;PFS:P=0.93,OS:P=0.33),between patients with PD-L1 CPS less than 5 and of 5 or more(PD-L1<5%vs PD-L1≥5%;PFS:P=0.409,OS:P=0.746),and between patients with PD-L1 CPS less than 10 and of 10 or more(PD-L1<10%vs PD-L1≥10%;PFS:P=0.529,OS:P=0.568).CONCLUSION Chemotherapy containing bevacizumab can be considered as first-line therapy in metastatic CRC irrespective of PD-L1 expression.

Drug-eluting beads chemoembolization combined with programmed cell death 1 inhibitor and lenvatinib for large hepatocellular carcinoma

BACKGROUND The combination of transarterial chemoembolization(TACE),lenvatinib,and programmed cell death 1(PD-1)inhibitor has been widely used in the treatment of advanced hepatocellular carcinoma(HCC)and has achieved promising results.However,there are few studies comparing whether drug-eluting beads TACE(DTACE)can bring more survival benefits to patients with large HCC compared to conventional TACE(C-TACE)in this triplet therapy.AIM To compare the efficacy and adverse events(AEs)of triple therapy comprising DTACE,PD-1 inhibitors,and lenvatinib(D-TACE-P-L)and C-TACE,PD-1 inhibitors,and lenvatinib(C-TACE-P-L)in patients with large HCC(maximum diameter≥5 cm),and analyze the prognostic factors.METHODS Following a comprehensive review of our hospital’s medical records,this retrospective study included 104 patients:50 received D-TACE-P-L,and 54 received CTACE-P-L.We employed Kaplan-Meier estimation to assess the median progression-free survival(PFS)between the two groups,utilized Cox multivariate regression analysis to identify prognostic factors,and applied theχ2 test to evaluate AEs.RESULTS The objective response rate(ORR)and median PFS were significantly higher in the D-TACE-P-L group compared to the C-TACE-P-L group(ORR:66.0%vs 44.4%,P=0.027;median PFS:6.8 months vs 5.0 months,P=0.041).Cox regression analysis identified treatment option,portal vein tumor thrombus,and hepatic vein invasion as protective factors for PFS.AEs were comparable between the two CONCLUSION D-TACE-P-L may have significantly better PFS and ORR for large HCC,while exhibiting similar AEs to C-TACE-PL.

Effectiveness and tolerability of programmed cell death protein-1 inhibitor+chemotherapy compared to chemotherapy for upper gastrointestinal tract cancers

BACKGROUND The combination of programmed cell death protein-1(PD-1)inhibitor and che-motherapy is approved as a standard first-or second-line treatment in patients with advanced oesophageal or gastric cancer.However,it is unclear whether this combination is superior to chemotherapy alone.AIM To assess the comparative effectiveness and tolerability of combining PD-1 inhibitors with chemotherapy vs chemotherapy alone in patients with advanced gastric cancer,gastroesophageal junction(GEJ)cancer,or oesophageal carcinoma.METHODS We searched the PubMed and Embase databases for studies that compared the efficacy and tolerance of PD-1 inhibitors in combination with chemotherapy vs chemotherapy alone in patients with advanced oesophageal or gastric cancer.We employed either random or fixed models to analyze the outcomes of each clinical trial,en-compassing data on overall survival(OS),progression-free survival(PFS),objective response rate,and adverse events(AEs).RESULTS Nine phase 3 clinical trials(7016 advanced oesophageal and gastric cancer patients)met the inclusion criteria.Our meta-analysis demonstrated that the pooled PD-1 inhibitor+chemotherapy group had a significantly longer OS than the chemotherapy-alone group[hazard ratio(HR)=0.76,95%confidence interval(CI):0.71-0.81];the pooled PFS result was consistent with that of OS(HR=0.67,95%CI:0.61-0.74).The count of patients achieving an objective response in the PD-1 inhibitor+chemotherapy group surpassed that of the chemotherapy-alone group[odds ratio(OR)=1.86,95%CI:1.59-2.18].AE incidence was also higher in the combination-therapy group than in the chemotherapy-alone group,regardless of whether≥grade 3 only(OR=1.30,95%CI:1.07-1.57)or all AE grades(OR=1.88,95%CI:1.39-2.54)were examined.We performed a subgroup analysis based on the programmed death-ligand 1(PD-L1)combined positive score(CPS)and noted extended OS and PFS durations within the CPS≥1,CPS≥5,and CPS≥10 subgroups of the PD-1 inhibitor+chemotherapy group.CONCLUSION In contrast to chemotherapy alone,the combination of PD-1 inhibitor and chemotherapy appears to present a more favorable option for initial or subsequent treatment in patients with gastric cancer,GEJ tumor,or oesophageal cancer.This holds true particularly for individuals with PD-L1 CPS scores of≥5 and≥10.

Programmed cell death 1 inhibitor sintilimab plus concurrent chemoradiotherapy for locally advanced pancreatic adenocarcinoma

BACKGROUND Pancreatic adenocarcinoma,a malignancy that arises in the cells of the pancreas,is a devastating disease with unclear etiology and often poor prognosis.Locally advanced pancreatic cancer,a stage where the tumor has grown significantly but has not yet spread to distant organs,presents unique challenges in treatment.This article aims to discuss the current strategies,challenges,and future directions in the management of locally advanced pancreatic adenocarcinoma(LAPC).AIM To investigate the feasibility and efficacy of programmed cell death 1(PD-1)inhibitor sintilimab plus concurrent chemoradiotherapy for LAPC.METHODS Eligible patients had LAPC,an Eastern cooperative oncology group performance status of 0 or 1,adequate organ and marrow functions,and no prior anticancer therapy.In the observation group,participants received intravenous sintilimab 200 mg once every 3 wk,and received concurrent chemoradiotherapy(concurrent conventional fractionated radiotherapy with doses planning target volume 50.4 Gy and gross tumor volume 60 Gy in 28 fractions and oral S-140 mg/m2 twice daily on days 1-14 of a 21-d cycle and intravenous gemcitabine 1000 mg/m2 on days 1 and 8 of a 21-d cycle for eight cycles until disease progression,death,or unacceptable toxicity).In the control group,participants only received concurrent chemoradiotherapy.From April 2020 to November 2021,64 participants were finally enrolled with 34 in the observation group and 30 in the control group.RESULTS Thirty-four patients completed the scheduled course of chemoradiotherapy,while 32(94.1%)received sintilimab plus concurrent chemoradiotherapy with 2 patients discontinuing sintilimab in the observation group.Thirty patients completed the scheduled course of chemoradiotherapy in the control group.Based on the Response Evaluation Criteria in Solid Tumors guidelines,the analysis of the observation group revealed that a partial response was observed in 11 patients(32.4%),stable disease was evident in 19 patients(55.9%),and 4 patients(11.8%)experienced progressive disease;a partial response was observed in 6(20.0%)patients,stable disease in 18(60%),and progressive disease in 6(20%)in the control group.The major toxic effects were leukopenia and nausea.The incidence of severe adverse events(AEs)(grade 3 or 4)was 26.5%(9/34)in the observation group and 23.3%(7/30)in the control group.There were no treatment-related deaths.The observation group demonstrated a significantly longer median overall survival(22.1 mo compared to 15.8 mo)(P<0.05)and progression-free survival(12.2 mo vs 10.1 mo)(P<0.05)in comparison to the control group.The occurrence of severe AEs did not exhibit a statistically significant difference between the observation group and the control group(P>0.05).CONCLUSION Sintilimab plus concurrent chemoradiotherapy was effective and safe for LAPC patients,and warrants further investigation.

Advances on biological evaluation methods of programmed cell death protein-1/ligand-1 inhibitors

Immuno-oncology represents a groundbreaking and well-established field within cancer treatment.Among the various immuno-oncology targets,the exploration of programmed cell death-1/ligand-1 for drug discovery has proven to be one of the most successful endeavors.Remarkably,it took nearly 30 years from the initial target identification to the clinical approval of monoclonal antibodies.Providing suitable and reliable bioassays for drug candidate evaluation is of paramount importance throughout the early stages of drug discovery,from lead compound identification to in vivo efficacy testing.This assay review aims to shed light on diverse assays reported in the literature for testing antagonism activity and efficacy of programmed cell death-1/ligand-1 inhibitors.Each of these assays possesses inherent advantages and can be applied in different research scenarios.The insights presented in this summary can serve as a valuable resource for scientists in this field,aiding in the selection of appropriate assays for their specific investigations.

Programmed death ligand-1 expression and its prognostic role in esophageal squamous cell carcinoma

AIM To investigate the expression and prognostic role of programmed death ligand-1(PD-L1) in locally advanced esophageal squamous cell carcinoma(ESCC).METHODS A total of 200 patients with ESCC who underwent radical esophagectomy with standard lymphadenectomy as the initial definitive treatment in Seoul National University Hospital from December 2000 to April 2013 were eligible for this analysis. Tissue microarrays were constructed by collecting tissue cores from surgical specimens, and immunostained with antibodies directed against PD-L1, p16, and c-Met. Medical records were reviewed retrospectively to assess clinical outcomes. Patients were divided into two groups by PD-L1 status, and significant differences in clinicopathologic characteristics between the two groups were assessed. RESULTS Tumor tissues from 67 ESCC patients(33.5%) were PDL1-positive. Positive p16 expression was observed in 21 specimens(10.5%). The H-score for c-Met expression was ≥ 50 in 42 specimens(21.0%). Although PDL1-positivity was not significantly correlated with any clinical characteristics including age, sex, smoking/alcoholic history, stage, or differentiation, H-scores for c-Met expression were significantly associated with PDL1-positivity(OR = 2.34, 95%CI: 1.16-4.72, P = 0.017). PD-L1 expression was not significantly associated with a change in overall survival(P = 0.656). In contrast, the locoregional relapse rate tended to increase(P = 0.134), and the distant metastasis rate was significantly increased(HR = 1.72, 95%CI: 1.01-2.79, P = 0.028) in patients with PD-L1-positive ESCC compared to those with PD-L1-negative ESCC.CONCLUSION PD-L1 expression is positively correlated with c-Met expression in ESCC. PD-L1 may play a critical role in distant failure and progression of ESCC.

Inhibition of MYC suppresses programmed cell death ligand-1 expression and enhances immunotherapy in triple-negative breast cancer

Background:Cancer immunotherapy has emerged as a promising strategy against triple-negative breast cancer(TNBC).One of the immunosuppressive pathways involves programmed cell death-1(PD-1)and programmed cell death ligand-1(PD-L1),but many patients derived little benefit from PD-1/PD-L1 checkpoint blockades treatment.Prior research has shown that MYC,a master transcription amplifier highly expressed in TNBC cells,can regulate the tumor immune microenvironment and constrain the efficacy of immunotherapy.This study aims to investigate the regulatory relationship between MYC and PD-L1,and whether a cyclin-dependent kinase(CDK)inhibitor that inhibits MYC expression in combination with anti-PD-L1 antibodies can enhance the response to immunotherapy.Methods:Public databases and TNBC tissue microarrays were used to study the correlation between MYC and PD-L1.The expression of MYC and PD-L1 in TNBCs was examined by quantitative real-time polymerase chain reaction and Western blotting.A patient-derived tumor xenograft(PDTX)model was used to evaluate the influence of a CDK7 inhibitor THZ1 on PD-L1 expression.Cell proliferation and migration were detected by 5-ethynyl-2′-deoxyuridine(EdU)cell proliferation and cell migration assays.Tumor xenograft models were established for in vivo verification.Results:A high MYC expression level was associated with a poor prognosis and could alter the proportion of tumor-infiltrating immune cells(TIICs).The positive correlation between MYC and PD-L1 was confirmed by immunostaining samples from 165 TNBC patients.Suppression of MYC in TNBC caused a reduction in the levels of both PD-L1 messenger RNA and protein.In addition,antitumor immune response was enhanced in the TNBC cancer xenograft mouse model with suppression of MYC by CDK7 inhibitor THZ1.Conclusions:The combined therapy of CDK7 inhibitor THZ1 and anti-PD-L1 antibody appeared to have a synergistic effect,which might offer new insight for enhancing immunotherapy in TNBC.

Myricetin inhibits interferon-γ-induced programmed death ligand-1 and indoleamine 2,3-dioxygenase 1 expression in lung cancer cells

OBJECTIVE Programmed death ligand-1(PD-L1)and indoleamine 2,3-dioxygenase 1(IDO1)are immune checkpoints which can be induced by interferon-γ(IFN-γ)in the tumor microenvironment,leading to immune escape of tumors.Myricetin(MY)is a flavonoid distributed in many edible and medicinal plants.The aim of this study is to clarify the effect and the mechanism of MY on inhibiting IFN-γ-induced PD-L1 and IDO1 in lung cancer cells.METHODS Expressions of PD-L1 and major histocompatibility complex-I(MHC-I)were evaluated by flow cytometry and Western blotting,and the expression of IDO1 was measured by Western blotting.qRT-PCR was used to detect their mRNA levels.The function of T cells was evaluated using a co-culture system consist of lung cancer cells and the Jurkat-PD-1 T cell line that overexpressing PD-1.Molecular docking analysis,Western blotting and immunofluorescence were used for mechanism study.RESULTS MY potently inhibited IFN-γ-induced PD-L1 and IDO1 expression in human lung cancer cells,while didn't show obvious effect on the expression of MHC-I.In addition,MY restored the survival,proliferation,CD69 expression and interleukin-2(IL-2)secretion of Jurkat-PD-1 T cells suppressed by IFN-γ-treated lung cancer cells in the co-culture system.Mechanistically,IFN-γup-regulated PD-L1 and IDO1 at the transcriptional level through the JAK-STAT-IRF1 axis,which was targeted and inhibited by MY.CONCLUSION Our research revealed a new insight into the anti-tumor effects of MY which inhibited IFN-γ-induced PD-L1 and IDO1 expression,supporting the potential of MY in anti-tumor immunotherapy.

Expression characteristics of peripheral lymphocyte programmed death 1 and FoxP3+ Tregs in gastric cancer during surgery and chemotherapy

BACKGROUND Programmed death 1(PD-1)and CD4^(+)CD25^(+)FoxP3^(+)expression in peripheral blood T-cells has been previously reported in various types of cancer.However,the specific variation tendency during surgery and chemotherapy,as well as their relationship in gastric cancer patients,still remain unclear.Understanding this aspect may provide some novel insights for future studies on tumor recurrence and tumor immune escape,and also serve as a reference for determining the optimal timing and dose of clinical anti-PD-1 antibodies.AIM To observe and analyze the expression characteristics of peripheral lymphocyte PD-1 and FoxP3^(+)regulatory T cells(FoxP3^(+)Tregs)before and after surgery or chemotherapy in gastric cancer patients.METHODS Twenty-nine stomach cancer patients undergoing chemotherapy after a D2 gastrectomy provided 10 mL peripheral blood samples at each phase of the perioperative period and during chemotherapy.This study also included 29 agematched healthy donors as a control group.PD-1 expression was detected on lymphocytes,including CD4^(+)CD8^(+)CD45RO^(+),CD4^(+)CD45RO^(+),and CD8^(+)CD45RO^(+)lymphocytes as well as regulatory T cells.RESULTS We observed a significant increase of PD-1 expression on immune subsets and a larger number of FoxP3^(+)Tregs in gastric cancer patients(P<0.05).Following D2 gastrectomy,peripheral lymphocytes PD-1 expression and the number of FoxP3^(+)Tregs notably decrease(P<0.05).However,during postoperative chemotherapy,we only observed a decrease in PD-1 expression on lymphocytes in the CD8^(+)CD45RO^(+)and CD8^(+)CD45RO^(+)populations.Additionally,linear correlation analysis indicated a positive correlation between PD-1 expression and the number of CD4^(+)CD45RO^(+)FoxP3high activated Tregs(aTregs)on the total peripheral lymphocytes(r=0.5622,P<0.0001).CONCLUSION The observed alterations in PD-1 expression and the activation of regulatory T cells during gastric cancer treatment may offer novel insights for future investigations into tumor immune evasion and the clinical application of anti-PD-1 antibodies in gastric cancer.

Immune-related adverse events induced by programmed death protein-1 inhibitors from the perspective of lymphoma immunotherapy

Lymphoma,which is highly malignant,stems from lymph nodes and lymphoid tissue.Lymphoma cells express programmed death-ligand 1/2(PD-L1/PD-L2),which binds with programmed cell death 1 protein(PD-1)to establish inhibitory signaling that impedes the normal function of T cells and allows tumor cells to escape immune system surveillance.Recently,immune checkpoint inhibitor immunotherapies such as PD-1 inhibitors(nivolumab and pembrolizumab)have been introduced into the lymphoma treatment algorithm and have shown remarkable clinical efficacy and greatly improve prognosis in lymphoma patients.Accordingly,the number of lymphoma patients who are seeking treatment with PD-1 inhibitors is growing annually,which results in an increasing number of patients developing immune-related adverse events(irAEs).The occurrence of irAEs inevitably affects the benefits provided by immunotherapy,particularly when PD-1 inhibitors are applied.However,the mechanisms and characteristics of irAEs induced by PD-1 inhibitors in lymphoma need further investigation.This review article summarizes the latest research advances in irAEs during treatment of lymphoma with PD-1 inhibitors.A comprehensive understanding of irAEs incurred in immunotherapy can help to achieve better efficacy with PD-1 inhibitors in lymphoma.

Natural course of chronic hepatitis B is characterized by changing patterns of programmed death type-1 of CD8-positive T cells

AIM:To investigate if and how programmed death type-1(PD-1)expression affects the natural course of hepatitis B virus(HBV)infection. METHODS:Sixty-four patients in different natural stages of chronic HBV infection were enrolled in this study.PD-1 expression in total T cells was detected by flow cytometry.Levels of total CD8+T cell responses and proliferation in relation to PD-1 expression levels were analyzed with intracellular staining and PD-1/ PD-L1 blockage. RESULTS:The PD-1 expression in T cells was dynamically changed during the natural course of chronic HBV infection,did not significantly increase in the immune tolerance phase,and returned to normal in the inactive virus carrier stage.Blockage of the PD-1/PD-L1 pathway could not affect the T-cell response in the immune tolerance and inactive virus carrier stages of chronic HBV infection.However,it could significantly restore the T-cell response in the immune clearance stage of chronic HBV infection.Furthermore,the PD-1 expression level in T cells was associated with the alanine aminotransferase level during the immune clearance stage of chronic HBV infection. CONCLUSION:The PD-l/PD-L1 pathway plays a different role in T-cell response during the natural course of chronic HBV infection.

Use of programmed cell death protein ligand 1 assay to predict the outcomes of non-small cell lung cancer patients treated with immune checkpoint inhibitors

The recent discovery of immune checkpoints inhibitors, especially anti-programmed cell death protein 1(PD-1)and anti-programmed cell death protein ligand 1(PD-L1) monoclonal antibodies, has opened new scenarios in the management of non-small cell lung cancer(NSCLC) and this new class of drugs has achieved a rapid development in the treatment of this disease. However, considering the costs of these drugs and the fact that only a subset of patients experience long-term disease control, the identification of predictive biomarkers for the selection of candidates suitable for treatment has become a priority. The research focused mainly on the expression of the PD-L1 receptor on both tumor cells and/or immune infiltrates determined by immunohistochemistry(IHC). However, different checkpoint inhibitors were tested, different IHC assays were used, different targets were considered(tumor cells, immune infiltrates or both) and different expression thresholds were employed in clinical trials. In some trials the assay was used prospectively to select the patients, while in other trials it was evaluated retrospectively. Some confusion emerges, which makes it difficult to easily compare the literature data and to translate them in practice management. This mini-review shows the possibilities and pitfalls of the PD-L1 expression to predict the activity and efficacy of anti PD1/PD-L1 monoclonal antibodies in the treatment of NSCLC.

Programmed cell death, antioxidant response and oxidative stress in wheat f lag leaves induced by chemical hybridization agent SQ-1

Male sterility induced by a chemical hybridization agent （CHA） is an important tool for utilizing crop heterosis. Leaves, especially the flag leaves, as CHA initial recipients play a decisive role in inducing male sterility. To investigate effects of different treatment times of CHA-SQ-1 used, morphological, biochemical and physiological responses of wheat flag leaves were detected in thistudy. CHA induced programmed cell death （PCD） as shown in terminal deoxynucleotidyl transferase-mediated dUTP nick end-labelling （TUNEL） and DNA laddering analysis. In the early phase, CHA-SQ-1 trig- gered organelle changes arid PCD in wheat leaves accompanied by excess production of reactive oxygen species （O2- and H202） and down-regulation of the activities of superoxide dismutase （SOD）, catalase （CAT） and guaiacol peroxidase （POD）. Meanwhile, leaf cell DNAs showed ladder-like patterns on agarose gel, indicating that CHA-SQ-1 led to the activation of the responsible endonuclease. The oxidative stress assays showed that lipid peroxidation was strongly activated and photosynthesis was obviously inhibited in SQ-l-induced leaves. However, CHA contents in wheat leaves gradually reduced along with the time CHA-SQ-1 applied. Young flags returned to an oxidative/antioxidative balance and ultimately developed into mature green leaves. These results provide explanation of the relations between PCD and anther abortion and practical application of CHA for hybrid breeding.

Comprehensive insights into the effects and regulatory mechanisms of immune cells expressing programmed death-1/programmed death ligand 1 in solid tumors

The programmed cell death-1(PD-1)/programmed cell death ligand 1(PD-L1)signaling pathway is an important mechanism in tumor immune escape,and expression of PD-L1 on tumor cells has been reported more frequently.However,accumulating evidence suggests that PD-1/PD-L1 is also widely expressed on immune cells,and that regulation is also critical for tumor immune responses.In this review,we emphasized that under solid tumor conditions,the immunoregulatory effects of immune cells expressing PD-1 or PD-L1,affected the prognoses of cancer patients.Therefore,a better understanding of the mechanisms that regulate PD-1 or PD-L1 expression on immune cells would provide clear insights into the increased efficacy of anti-PD antibodies and the development of novel tumor immunotherapy strategies.

Prognostic value of programmed death.1, programmed death-ligand 1, programmed death-ligand 2 expression, and CD8(+) T cell density in primary tumors and metastatic lymph nodes from patients with stage T1.4N+M0 gastric adenocarcinoma

Background: Anti-programmed death-1/programmed death-ligand 1(PD-1/PD-L1) immunotherapy has been proved to be effective on gastric cancer in ongoing clinical trials. However, the value of PD-L1 in predicting responses of patients with gastric cancer to anti-PD-1/PD-L1 immunotherapy is controversial. Some studies suggested that intra-and inter-tumoral heterogeneity of PD-L1 expression might explain the controversy.This study aimed to analyze the expression of PD-L1, PD-L2, and PD-1 as well as CD8(+) T-cell density in primary tumors and lymph nodes from patients with stage T1-4 N+M0 gastric adenocarcinoma to explore the heterogeneity of PD-1 signaling pathway molecules.Methods: In primary tumors and metastatic as well as non-metastatic lymph nodes from patients with stage T1-4 N+M0 gastric adenocarcinoma, we detected PD-L1 and PD-L2 expression with immunohistochemistry. CD8(+)T-cell density in primary tumors and PD-1 expression on CD8(+)T cells were detected with immunofluorescence. Univariate analysis was used to determine the prognostic values of them. Cox proportional hazard regression model was used to identify independent risk factors that affect patients' overall survival and disease-free survival.Results: Among 119 eligible patients who had undergone surgical resection, the positive rate of PD-L1 was higher in metastatic lymph nodes than in primary tumors(45.4% vs. 38.7%, P = 0.005); the positive rate of PD-1 on CD8(+)T cells was significantly higher in primary tumors and metastatic lymph nodes than in tumor-free lymph nodes(both P < 0.001). The intensity of PD-1 expression on CD8(+) T cells in primary tumors and in metastatic lymph nodes were stronger than that in tumor-free lymph nodes from the same patient. Beside, the positive rate of PD-L2 did not show any differences between primary tumors and metastatic lymph nodes. In multivariate analysis, PD-L1 expression,PD-L2 expression, a low density of CD8(+) T cells in primary tumors, and PD-1 expression on CD8(+) T cells in primary tumors were associated with poor prognosis.Conclusion: The expression of PD-L1 is heterogeneous in primary tumors and in metastatic lymph nodes from patients with stageT1-4 N+M0 gastric adenocarcinoma, which might explain the inconsistent results in assessing the prognostic value of PD-L1 expression in previous studies.

Expression and clinical value of programmed cell death-ligand 1(PD-L1)in diffuse large B cell lymphoma:a retrospective study

Background: The programmed cell death-1(PD-1)/programmed cell death-ligand 1(PD-L1) pathway inhibits the activation of T cells and plays a crucial role in the negative regulation of cellular and humoral immune responses.Diffuse large B-cell lymphoma(DLBCL) is the most common lymphoid malignancy in adults. In the present study, we aimed to detect the expression of PD-L1 in DLBCL and to analyze its relationship with prognosis.Methods: We reviewed medical records of 204 newly diagnosed DLBCL patients in Sun Yat-sen University Cancer Center between October 2005 and August 2012. The expression of PD-L1 in tumor tissues from these 204 patients was detected using immunohistochemical(IHC) assay. The expression of anaplastic lymphoma kinase(ALK), CD5,CD30, and C-Myc in tumor specimens from 109 patients was detected using IHC, and Epstein-Barr virus(EBV)-encoded RNAs(EBERs) were detected using fluorescence in situ hybridization. The Spearman method was used for correlation analysis. The Kaplan-Meier method with log-rank test was used for univariate analysis. Cox proportional hazards model was used for multivariate analysis.Results: Of the 204 patients, 100(49.0%) were PD-L1-positive in tumor cells and 44(21.6%) were PD-L1-positive in tumor microenvironment. PD-L1 expression in tumor cells and tumor microenvironment were more common in the non-germinal center B-cell-like(GCB) subtype than in the GCB subtype(P = 0.02 and P= 0.04). Patients with PD-L1 expression in tumor microenvironment were more likely to be resistant to first-line chemotherapy when compared with the patients without PD-L1 expression in tumor microenvironment(P = 0.03). PD-L1 expression in tumor microenvironment was negatively correlated with C-Myc expression(r =-0.20, P = 0.04). No correlations were detected between PD-L1 expression and the expression of ALK, CD5, and CD30 as well as EBERs. The 5-year overall survival(OS)rates were 50.0% and 67.3% in patients with and without PD-L1 expression in tumor cells(P = 0.02). PD-L1 expression in tumor cells was an independent risk predictor for OS(P < 0.01).Conclusions: PD-L1 expression is more common in the non-GCB subtype than in the GCB subtype. PD-L1 expression in tumor microenvironment has a negative correlation with C-Myc. PD-L1 positivity predicts short survival in DLBCL patients. For patients with PD-L1 expression, more strategy such as anti-PD-L1 antibody treatment should be recommended.

The prognostic value of programmed cell death ligand 1expression in non-Hodgkin lymphoma:a meta-analysis

Objective: Although the prognostic value of programmed cell death-ligand 1(PD-L1) expression in non-Hodgkin lymphoma(NHL) has been evaluated in many studies, the results remain controversial. To investigate the prognostic role of PD-L1 expression and the association between PD-L1 expression and clinicopathological features of NHL, we performed a meta-analysis.Methods: The Pub Med, EMBASE, and Cochrane Library databases were searched up to November 30, 2017. The hazard ratio(HR), 95% confidence interval(CI), and odds ratios(OR) with 95% CIs were combined to evaluate the association of PD-L1 expression with overall survival(OS) and clinicopathological features. Review manager 5.3 and STATA 12.0 were used in this meta-analysis.Results: A total of 2,005 patients across nine studies were enrolled in our meta-analysis, and the pooled results showed that high PD-L1 expression was associated with a poor prognosis(HR=2.04, 95% CI: 1.18–3.54, P=0.01). In the subgroup analysis according to histology types, pooled results demonstrated that an increased PD-L1 expression was an unfavorable prognostic factor for diffuse large B-cell lymphoma(HR=1.92, 95% CI: 1.06–3.48, P=0.03) but not for natural killer/T-cell lymphoma(HR=2.41, 95%CI: 0.47–12.22, P=0.29). Pooled ORs indicated that PD-L1 expression was higher in NHL with international prognostic indices of≥3. However, PD-L1 expression had no correlation with gender, age, disease stage, lactate dehydrogenase level, B symptoms, and germinal center B-cell-like lymphoma.Conclusions: High PD-L1 expression was a poor prognostic biomarker in patients with NHL. Because of our limited sample size,high-quality studies with larger sample sizes are needed to validate our results.

Programmed cell death-1 inhibitor-related sclerosing cholangitis:A systematic review

BACKGROUND Programmed cell death-1(PD-1)inhibitor has been indicated for many types of malignancies.However,these inhibitors also cause immune-related adverse events.Hepatobiliary disorder is a phenotype of immune-related adverse event affecting 0%–4.5%of patients treated with PD-1 inhibitors.Recent studies have reported PD-1 inhibitor-related sclerosing cholangitis(SC);however,the associated clinical and pathological features are unclear.AIM To evaluate the clinical and pathological features of PD-1 inhibitor-related SC through a systematic review of the literature.METHODS The review,conducted using electronic databases in PubMed,was restricted to the period from January 2014 to September 2019 and focused on case reports/series on PD-1 inhibitor-related SC published in English.We scanned the references of the selected literature to identify any further relevant studies.Six cases previously studied by us,including three that have not yet been published,were included in this review.RESULTS Thirty-one PD-1 inhibitor-related SC cases were evaluated.Median age of patients was 67 years(range,43–89),with a male to female ratio of 21:10.The main disease requiring PD-1 inhibitor treatment was non-small cell lung cancer.Agents that caused PD-1 inhibitor-related SC were nivolumab(19 cases),pembrolizumab(10 cases),avelumab(1 case),and durvalumab(1 case).The median number of cycles until PD-1 inhibitor-related SC onset was 5.5(range,1–27).Abdominal pain or discomfort(35.5%,11/31)was the most frequent symptom.Blood serum tests identified liver dysfunction with a notable increase in biliary tract enzymes relative to hepatic enzymes,and a normal level of serum immunoglobulin G4.Biliary dilation without obstruction(76.9%,20/26),diffuse hypertrophy of the extrahepatic biliary tract(90.5%,19/21),and multiple strictures of the intrahepatic biliary tract(30.4%,7/23)were noted.In 11/23(47.8%)cases,pathological examination indicated that CD8+T cells were the dominant inflammatory cells in the bile duct or peribiliary tract.Although corticosteroids were mainly used for PD inhibitor-related SC treatment,the response rate was 11.5%(3/26).CONCLUSION Some clinical and pathological features of PD-1 inhibitor-related SC were revealed.To establish diagnostic criteria for PD-1 inhibitor-related SC,more cases need to be evaluated.