Hyperactivation of DNA repairing pathway is highly associated with the chemosensitivity and chemoresistance of cancer cells.In this manuscript,guided by cascaded one strain many compounds-global natural products socia...Hyperactivation of DNA repairing pathway is highly associated with the chemosensitivity and chemoresistance of cancer cells.In this manuscript,guided by cascaded one strain many compounds-global natural products social molecular networking(OSMAC-GNPS)strategy,a pair of epimeric environmental-induced metabolites were isolated from Aspergillus sp.EGF 15-0-3.Structurally,sterpiperazines A(1)and B(2)represent the first steroid-based indole alkaloids with unprecedented backbones.Biologically,compound 1 could be identified as a novel tyrosyl-DNA phosphodiesterase 1(Tdp1)inhibitor with a unique mechanism distinct from the reported modulators,and was able to significantly enhance the sensitivity of NCI-H460 cells to the clinic chemotherapeutic drug through inhibiting the DNA repairment and enhanced the DNA damage of cancer cells.展开更多
Prenatal caffeine exposure(PCE)leads to intrauterine growth retardation and altered glucose homeostasis after birth,but the underlying mechanism remains unclear.This study aims to investigate the alteration of pancrea...Prenatal caffeine exposure(PCE)leads to intrauterine growth retardation and altered glucose homeostasis after birth,but the underlying mechanism remains unclear.This study aims to investigate the alteration of pancreatic development and insulin biosynthesis in the PCE female offspring and explore the intrauterine programming mechanism.Pregnant rats were orally treated with 120 mg/(kg·day)of caffeine from gestational day(GD)9 to 20.Results showed that fetal pancreaticβ-cells in the PCE group exhibited reduced mass and impaired insulin synthesis function,as evidenced by decreased expression of developmental and functional genes and reduced pancreatic insulin content.At postnatal week(PW)12,the PCE offspring exhibited glucose intolerance,diminishedβ-cell mass,and lower blood insulin levels.However,by PW28,glucose tolerance showed some improvement.Both in vivo and in vitro findings collectively indicated that excessive serum corticosterone(CORT)levels of the PCE fetuses may act through the activation of the pancreatic glucocorticoid receptor(GR)and recruitment of histone deacetylase 9(HDAC9),leading to H3K9 deacetylation in promoter and downregulation of insulin-like growth factor 1(IGF1),thereby inhibiting pancreatic islet morphogenesis and insulin synthesis in fetal rats.Furthermore,the PCE offspring after birth exhibited decreased blood CORT levels,increased H3K9 acetylation in promoter and upregulated gene expression of the pancreatic IGF1 promoter region,accompanied by elevated insulin biosynthesis.However,when exposed to chronic stress,the above changes were totally reversed.Conclusively,“glucocorticoid-insulin like growth factor 1(GC-IGF1)axis”programming may be involved in pancreaticβ-cell dysplasia and dysfunction in the PCE female offspring.展开更多
Quadratic 0-1 problems with linear inequality constraints are briefly considered in this paper.Global optimality conditions for these problems,including a necessary condition and some sufficient conditions,are present...Quadratic 0-1 problems with linear inequality constraints are briefly considered in this paper.Global optimality conditions for these problems,including a necessary condition and some sufficient conditions,are presented.The necessary condition is expressed without dual variables.The relations between the global optimal solutions of nonconvex quadratic 0-1 problems and the associated relaxed convex problems are also studied.展开更多
In this paper,quadratic 0-1 programming problem (I) is considered, in terms of its features quadratic 0-1 programming problem is solved by linear approxity heurstic algrothm and a developed tabu search ahgrothm .
0-1 programming is a special case of the integer programming, which is commonly encountered in many optimization problems. Neural network and its general energy function are presented for 0-1 optimization problem. The...0-1 programming is a special case of the integer programming, which is commonly encountered in many optimization problems. Neural network and its general energy function are presented for 0-1 optimization problem. Then, the 0-1 optimization problems are solved by a neural network model with transient chaotic dynamics (TCNN). Numerical simulations of two typical 0-1 optimization problems show that TCNN can overcome HNN's main drawbacks that it suffers from the local minimum and can search for the global optimal solutions in to solveing 0-1 optimization problems.展开更多
To gain superior computational efficiency, it might be necessary to change the underlying philosophy of the simplex method. In this paper, we propose a Phase-1 method along this line. We relax not only the conventiona...To gain superior computational efficiency, it might be necessary to change the underlying philosophy of the simplex method. In this paper, we propose a Phase-1 method along this line. We relax not only the conventional condition that some function value increases monotonically, but also the condition that all feasible variables remain feasible after basis change in Phase-1. That is, taking a purely combinatorial approach to achieving feasibility. This enables us to get rid of ratio test in pivoting, reducing computational cost per iteration to a large extent. Numerical results on a group of problems are encouraging.展开更多
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...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.展开更多
BACKGROUND Hepatocellular carcinoma(HCC)is an inflammation-associated tumor with a dismal prognosis.Immunotherapy has become an important treatment strategy for HCC,as immunity is closely related to inflammation in th...BACKGROUND Hepatocellular carcinoma(HCC)is an inflammation-associated tumor with a dismal prognosis.Immunotherapy has become an important treatment strategy for HCC,as immunity is closely related to inflammation in the tumor microenvir-onment.Inflammation regulates the expression of programmed death ligand-1(PD-L1)in the immunosuppressive tumor microenvironment and affects im-munotherapy efficacy.Interleukin-17A(IL-17A)is involved in the remodeling of the tumor microenvironment and plays a protumor or antitumor role in different tumors.We hypothesized that IL-17A participates in tumor progression by affe-cting the level of immune checkpoint molecules in HCC.The upregulation of PD-L1 expression in HCC cells by IL-17A was assessed by reverse transcription PCR,western blotting,and flow cytometry.Mechanistic studies were conducted with gene knockout models and pathway inhibitors.The function of IL-17A in immune evasion was explored through coculture of T cells and HCC cells.The effects of IL-17A on the malignant biological behaviors of HCC cells were evaluated in vitro,and the antitumor effects of an IL-17A inhibitor and its synergistic effects with a PD-L1 inhibitor were studied in vivo.RESULTS IL-17A upregulated PD-L1 expression in HCC cells in a dose-dependent manner,whereas IL-17A receptor knockout or treatment with a small mothers against decapentaplegic 2 inhibitor diminished the PD-L1 expression induced by IL-17A.IL-17A enhanced the survival of HCC cells in the coculture system.IL-17A increased the viability,G2/M ratio,and migration of HCC cells and decreased the apoptotic index.Cyclin D1,VEGF,MMP9,and Bcl-1 expression increased after IL-17A treatment,whereas BAX expression decreased.The combination of IL-17A and PD-L1 inhibitors showed synergistic antitumor efficacy and increased cluster of differentiation 8+T lymphocyte infiltration in an HCC mouse model.CONCLUSION IL-17A upregulates PD-L1 expression via the IL-17A receptor/phosphorylation-small mothers against decapenta-plegic 2 signaling pathway in HCC cells.Blocking IL-17A enhances the therapeutic efficacy of PD-L1 antibodies in HCC in vivo.展开更多
基金supported by the National Natural Science Foundation of China(Nos.82273845,82304331,and 82360695)Guangxi Natural Science Foundation project(No.2023GXNSFBA026305).
文摘Hyperactivation of DNA repairing pathway is highly associated with the chemosensitivity and chemoresistance of cancer cells.In this manuscript,guided by cascaded one strain many compounds-global natural products social molecular networking(OSMAC-GNPS)strategy,a pair of epimeric environmental-induced metabolites were isolated from Aspergillus sp.EGF 15-0-3.Structurally,sterpiperazines A(1)and B(2)represent the first steroid-based indole alkaloids with unprecedented backbones.Biologically,compound 1 could be identified as a novel tyrosyl-DNA phosphodiesterase 1(Tdp1)inhibitor with a unique mechanism distinct from the reported modulators,and was able to significantly enhance the sensitivity of NCI-H460 cells to the clinic chemotherapeutic drug through inhibiting the DNA repairment and enhanced the DNA damage of cancer cells.
基金supported by grants from the National Key Research and Development Program of China(2020YFA0803900)the National Natural Science Foundation of China(U23A20407,82414020,81703631)the Hubei Provincial Natural Science Foundation of China(2024AFB742)。
文摘Prenatal caffeine exposure(PCE)leads to intrauterine growth retardation and altered glucose homeostasis after birth,but the underlying mechanism remains unclear.This study aims to investigate the alteration of pancreatic development and insulin biosynthesis in the PCE female offspring and explore the intrauterine programming mechanism.Pregnant rats were orally treated with 120 mg/(kg·day)of caffeine from gestational day(GD)9 to 20.Results showed that fetal pancreaticβ-cells in the PCE group exhibited reduced mass and impaired insulin synthesis function,as evidenced by decreased expression of developmental and functional genes and reduced pancreatic insulin content.At postnatal week(PW)12,the PCE offspring exhibited glucose intolerance,diminishedβ-cell mass,and lower blood insulin levels.However,by PW28,glucose tolerance showed some improvement.Both in vivo and in vitro findings collectively indicated that excessive serum corticosterone(CORT)levels of the PCE fetuses may act through the activation of the pancreatic glucocorticoid receptor(GR)and recruitment of histone deacetylase 9(HDAC9),leading to H3K9 deacetylation in promoter and downregulation of insulin-like growth factor 1(IGF1),thereby inhibiting pancreatic islet morphogenesis and insulin synthesis in fetal rats.Furthermore,the PCE offspring after birth exhibited decreased blood CORT levels,increased H3K9 acetylation in promoter and upregulated gene expression of the pancreatic IGF1 promoter region,accompanied by elevated insulin biosynthesis.However,when exposed to chronic stress,the above changes were totally reversed.Conclusively,“glucocorticoid-insulin like growth factor 1(GC-IGF1)axis”programming may be involved in pancreaticβ-cell dysplasia and dysfunction in the PCE female offspring.
文摘Quadratic 0-1 problems with linear inequality constraints are briefly considered in this paper.Global optimality conditions for these problems,including a necessary condition and some sufficient conditions,are presented.The necessary condition is expressed without dual variables.The relations between the global optimal solutions of nonconvex quadratic 0-1 problems and the associated relaxed convex problems are also studied.
文摘In this paper,quadratic 0-1 programming problem (I) is considered, in terms of its features quadratic 0-1 programming problem is solved by linear approxity heurstic algrothm and a developed tabu search ahgrothm .
基金This project was supported by the National Natural Science Foundation of China (79970042).
文摘0-1 programming is a special case of the integer programming, which is commonly encountered in many optimization problems. Neural network and its general energy function are presented for 0-1 optimization problem. Then, the 0-1 optimization problems are solved by a neural network model with transient chaotic dynamics (TCNN). Numerical simulations of two typical 0-1 optimization problems show that TCNN can overcome HNN's main drawbacks that it suffers from the local minimum and can search for the global optimal solutions in to solveing 0-1 optimization problems.
文摘To gain superior computational efficiency, it might be necessary to change the underlying philosophy of the simplex method. In this paper, we propose a Phase-1 method along this line. We relax not only the conventional condition that some function value increases monotonically, but also the condition that all feasible variables remain feasible after basis change in Phase-1. That is, taking a purely combinatorial approach to achieving feasibility. This enables us to get rid of ratio test in pivoting, reducing computational cost per iteration to a large extent. Numerical results on a group of problems are encouraging.
文摘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.
基金Supported by the Natural Science Foundation of Gansu Province,No.21JR7RA373 and No.24JRRA295.
文摘BACKGROUND Hepatocellular carcinoma(HCC)is an inflammation-associated tumor with a dismal prognosis.Immunotherapy has become an important treatment strategy for HCC,as immunity is closely related to inflammation in the tumor microenvir-onment.Inflammation regulates the expression of programmed death ligand-1(PD-L1)in the immunosuppressive tumor microenvironment and affects im-munotherapy efficacy.Interleukin-17A(IL-17A)is involved in the remodeling of the tumor microenvironment and plays a protumor or antitumor role in different tumors.We hypothesized that IL-17A participates in tumor progression by affe-cting the level of immune checkpoint molecules in HCC.The upregulation of PD-L1 expression in HCC cells by IL-17A was assessed by reverse transcription PCR,western blotting,and flow cytometry.Mechanistic studies were conducted with gene knockout models and pathway inhibitors.The function of IL-17A in immune evasion was explored through coculture of T cells and HCC cells.The effects of IL-17A on the malignant biological behaviors of HCC cells were evaluated in vitro,and the antitumor effects of an IL-17A inhibitor and its synergistic effects with a PD-L1 inhibitor were studied in vivo.RESULTS IL-17A upregulated PD-L1 expression in HCC cells in a dose-dependent manner,whereas IL-17A receptor knockout or treatment with a small mothers against decapentaplegic 2 inhibitor diminished the PD-L1 expression induced by IL-17A.IL-17A enhanced the survival of HCC cells in the coculture system.IL-17A increased the viability,G2/M ratio,and migration of HCC cells and decreased the apoptotic index.Cyclin D1,VEGF,MMP9,and Bcl-1 expression increased after IL-17A treatment,whereas BAX expression decreased.The combination of IL-17A and PD-L1 inhibitors showed synergistic antitumor efficacy and increased cluster of differentiation 8+T lymphocyte infiltration in an HCC mouse model.CONCLUSION IL-17A upregulates PD-L1 expression via the IL-17A receptor/phosphorylation-small mothers against decapenta-plegic 2 signaling pathway in HCC cells.Blocking IL-17A enhances the therapeutic efficacy of PD-L1 antibodies in HCC in vivo.
