AIM： To investigate the effect of （-）-epigallocatechin-3-gallate （EGCG） on growth of gastric cancer and its possible mechanism. METHODS： Heterotopic tumors were induced by subcutaneously injection of SGC-7901 ce...AIM： To investigate the effect of （-）-epigallocatechin-3-gallate （EGCG） on growth of gastric cancer and its possible mechanism. METHODS： Heterotopic tumors were induced by subcutaneously injection of SGC-7901 cells in nude mice. Tumor growth was measured by calipers in two dimensions. Tumor angiogenesis was determined with tumor microvessel density （MVD） by immunohistology. Vascular endothelial growth factor （VEGF） protein level and activation of signal transducer and activator of transcription 3 （Star3） were examined by Western blotting. VEGF mRNA expression was determined by RT-PCR and VEGF release in tumor culture medium by ELISA. VEGF-induced cell proliferation was studied by MTT assay, cell migration by gelatin modified Boyden chamber （Transwell） and in vitro angiogenesis by endothelial tube formation in Matrigel. RESULTS： Intraperitoneal injection of EGCG inhibited the growth of gastric cancer by 60.4%. MVD in tumor tissues treated with EGCG was markedly reduced. EGCG treatment reduced VEGF protein level in vitro and in vivo. Secretion and mRNA expression of VEGF in tumor cells were also suppressed by EGCG in a dose-dependent manner. This inhibitory effect was associated with reduced activation of Star3, but EGCG treatment did not change the total Star3 expression. EGCG also inhibited VEGF-induced endothelial cell proliferation, migration and tube formation. CONCLUSION： EGCG inhibits the growth of gastric cancer by reducing VEGF production and angiogenesis, and is a promising candidate for anti-angiogenic treatment of gastric cancer.展开更多
AIM: To demonstrate that (-)-Epigallocatechin-3-gallate (EGCG) inhibits vascular endothelial growth factor (VEGF) expression and angiogenesis induced by interleukin-6 (IL-6) via suppressing signal transducer and activ...AIM: To demonstrate that (-)-Epigallocatechin-3-gallate (EGCG) inhibits vascular endothelial growth factor (VEGF) expression and angiogenesis induced by interleukin-6 (IL-6) via suppressing signal transducer and activator of transcription 3 (Stat3) activity in gastric cancer. METHODS: Human gastric cancer (AGS) cells were treated with IL-6 (50 ng/mL) and EGCG at different concentrations. VEGF, total Stat3 and activated Stat3 protein levels in the cell lyses were examined by Western blotting, VEGF protein level in the conditionedmedium was measured by enzyme-linked immunosorbent assay, and the level of VEGF mRNA was evaluated by reverse transcription polymerase chain reaction (RTPCR). Stat3 nuclear translocation was determined by Western blotting with nuclear extract, and Stat3-DNA binding activity was examined with Chromatin immunoprecipitation (ChIP) assay. IL-6 induced endothelial cell proliferation was measured with 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazoliumbromide assay, in vitro angiogenesis was determined with endothelial cell tube formation assay in Matrigel, and IL-6-induced angiogenesis in vitro was measured with Matrigel plug assay. RESULTS: There was a basal expression and secretion of VEGF in AGS cells. After stimulation with IL-6, VEGF expression was apparently up-regulated and a 2.4-fold increase was observed. VEGF secretion in the conditioned medium was also increased by 2.8 folds. When treated with EGCG, VEGF expression and secretion were dose-dependently decreased. IL-6 also increased VEGF mRNA expression by 3.1 folds. EGCG treatment suppressed VEGF mRNA expression in a dose-dependent manner. EGCG dose-dependently inhibited Stat3 activation induced by IL-6, but did not change the total Stat3 expression. When treated with EGCG or AG490, VEGF expressions were reduced to the level or an even lower level in the tumor cells not stimulated with IL-6. However, PD98059 and LY294002 did not change VEGF expression induced by IL-6. EGCG inhibited Stat3 nucleus translocation, and Stat3-DNA bindi展开更多
It has been established that cancer can be promoted and exacerbated by inflammation.Hepatocellular carcinoma(HCC) is the fifth most common cancer worldwide,and its long-term prognosis remains poor.Although HCC is a co...It has been established that cancer can be promoted and exacerbated by inflammation.Hepatocellular carcinoma(HCC) is the fifth most common cancer worldwide,and its long-term prognosis remains poor.Although HCC is a complex and heterogeneous tumor with several genomic mutations,it usually develops in the context of chronic liver damage and inflammation,suggesting that understanding the mechanism(s) of inflammation-mediated hepatocarcinogenesis is essential for the treatment and prevention of HCC.Chronic liver damage induces a persistent cycle of necroinflammation and hepatocyte regeneration,resulting in genetic mutations in hepatocytes and expansion of initiated cells,eventually leading to HCC development.Recently,several inflammation-and stress-related signaling pathways have been identified as key players in these processes,which include the nuclear factor B,signal transducer and activator of transcription,and stress-activated mitogen-activated protein kinase pathways.Although these pathways may suggest potential therapeutic targets,they have a wide range of functions and complex crosstalk occurs among them.This review focuses on recent advances in our understanding of the roles of these signaling pathways in hepatocarcinogenesis.展开更多
AIM: To investigate the dynamic expression of p-signal transducer and activator of transcription 3 (STAT3) and vascular endothelial growth factor (VEGF) in the formation of gastric tumors induced by drinking water con...AIM: To investigate the dynamic expression of p-signal transducer and activator of transcription 3 (STAT3) and vascular endothelial growth factor (VEGF) in the formation of gastric tumors induced by drinking water containing N-methyl-N’-nitro-N-nitrosoguanidine (MNNG) in Wistar rats. METHODS: One hundred and twenty Wistar rats were randomly divided into two groups (60 in each group): Control group and Model group. The rats in each group were then randomly divided into three groups (20 in each group): C/M15, C/M25 and C/M40 (15, 25 and 40 represent the number of feeding weeks from termination). Rats in the control group received normal drinking water and rats in the model group received drinking water containing 100 μg/mL MNNG. Stomach tissues were collected at the end of the 15<sup>th</sup>, 25<sup>th</sup> and 40<sup>th</sup> week, respectively, for microscopic measurement using hematoxylin and eosin staining. The expression of p-STAT3 and VEGF in different pathological types of gastric tissue, including normal, inflammation, atrophy, hyperplasia and gastric stromal tumor, was observed by immunohistochemistry and Western blot, and the corelation between p-STAT3 and VEGF was analyzed. RESULTS: (1) The expression of p-STAT3 in tissue with gastritis, atrophy, dysplasia and gastric stromal tumor were significantly increased in the model group compared with the control group (2.5 ± 1.0, 2.75 ± 0.36, 6.2 ± 0.45, 5.67 ± 0.55 vs 0.75 ± 0.36, P = 0.026, 0.035, 0.001, 0.002, respectively); the expression of p-STAT3 in tissue with dysplasia was higher than that in samples with gastritis or atrophy (6.2 ± 0.45 vs 2.5 ± 1.0, P = 0.006; 6.2 ± 0.45 vs 2.75 ± 0.36, P = 0.005, respectively); however, the expression of p-STAT3 in gastritis and atrophy was not significantly different (P > 0.05); (2) the expression of VEGF in tissue with gastritis, atrophy, dysplasia and gastric stromal tumor was significantly increased in the model group compared with normal g展开更多
Signaling pathways of gastric carcinogenesis and gastric cancer progression are being avidly studied to seek optimal treatment of gastric cancer. Among them, hepatocyte growth factor (HGF)/c-MET, phosphoinositide 3-ki...Signaling pathways of gastric carcinogenesis and gastric cancer progression are being avidly studied to seek optimal treatment of gastric cancer. Among them, hepatocyte growth factor (HGF)/c-MET, phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) and janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) pathways have been widely investigated. Their aberrant expression or mutation has been significantly associated with advanced stage or poor prognosis of gastric cancer. Recently, aberrations of immune checkpoints including programmed cell death-1/programmed cell death ligand-1 (PD-1/PD-L1) have been suggested as an important step in the formation of a microenvironment favorable for gastric cancer. Accomplishments in basic research have led to the development of novel agents targeting these signaling pathways. However, phase III studies of selective anti-HGF/c-MET antibodies and mTOR inhibitor failed to show significant benefits in terms of overall survival and progression-free survival. Few agents directly targeting STAT3 have been developed. However, this target is still critical issue in terms of chemoresistance, and SH2-containing protein tyrosine phosphatase 1 might be a significant link to effectively inhibit STAT3 activity. Inhibition of PD-1/PD-L1 showed durable efficacy in phase I studies, and phase III evaluation is warranted. Therapeutic strategy to concurrently inhibit multiple tyrosine kinases is a reasonable option, however, lapatinib needs to be further evaluated to identify good responders. Regorafenib has shown promising effectiveness in prolonging progression-free survival in a phase II study. In this topic highlight, we review the biologic roles and outcomes of clinical studies targeting these signaling pathways.展开更多
Objective:To explore the anti-inflammatory effects of ethyl lithospermate in lipopolysaccharide(LPS)-stimulated RAW 264.7 murine-derived macrophages and zebrafish,and its underlying mechanisms.Methods:3-[4,5-dimethylt...Objective:To explore the anti-inflammatory effects of ethyl lithospermate in lipopolysaccharide(LPS)-stimulated RAW 264.7 murine-derived macrophages and zebrafish,and its underlying mechanisms.Methods:3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazoliumbromide(MTT)assays were performed to investigate the toxicity of ethyl lithospermate at different concentrations(12.5–100μmol/L)in RAW 264.7 cells.The cells were stimulated with LPS(100 ng/mL)for 12 h to establish an inflammation model in vitro,the production of proinflammatory cytokines interleukin(IL)-6 and tumor necrosis factorα(TNF-α)were assessed by enzyme linked immunosorbent assay(ELISA).Western blot was used to ascertain the protein expressions of signal transducer and activator of transcription 3(STAT3),nuclear factor kappa B(NF-κB)p65,phospho-STAT3(p-STAT3,Tyr705),inhibitor of NF-κB(IκB)α,and phospho-IκBα(p-IκBα,Ser32),and confocal imaging was used to identify the nuclear translocation of NF-κB p65 and p-STAT3(Tyr705).Additionally,the yolk sacs of zebrafish(3 days post fertilization)were injected with 2 nL LPS(0.5 mg/mL)to induce an inflammation model in vivo.Survival analysis,hematoxylin-eosin(HE)staining,observation of neutrophil migration,and quantitative real-time polymerase chain reaction(qR T-PCR)were used to further study the anti-inflammatory effects of ethyl lithospermate and its probable mechanisms in vivo.Results:The non-toxic concentrations of ethyl lithospermate have been found to range from 12.5 to 100μmol/L.Ethyl lithospermate inhibited the release of IL-6 and TNF-α(P<0.05 or P<0.01),decreased IκBαdegradation and phosphorylation(P<0.05)as well as the nuclear translocation of NF-κB p65 and p-STAT3(Tyr705)in LPS-induced RAW 264.7 cells(P<0.01).Ethyl lithospermate also decreased inflammatory cells infiltration and neutrophil migration while increasing the survival rate of LPS-stimulated zebrafish(P<0.05 or P<0.01).In addition,ethyl lithospermate also inhibited the mR NA expression levels of of IL-6,TNF-α,IκBα,STAT3,and NF展开更多
AIM： To analyze the effects of NF-kB inhibition by antioxidant pyrrolidine dithiocarbamate （PDTC） or TNF inhibitor pentoxifylline （PTX） on liver regeneration after partial hepatectomy （PH）. METHODS： Saline, PD...AIM： To analyze the effects of NF-kB inhibition by antioxidant pyrrolidine dithiocarbamate （PDTC） or TNF inhibitor pentoxifylline （PTX） on liver regeneration after partial hepatectomy （PH）. METHODS： Saline, PDTC or PTX were injected 1 h before PH and rats were killed at 0.5 and 24 h after PH. Several control groups were used for comparison （injection control groups）. RESULTS： Compared to saline injected controls, NF-kB activation was absent 0.5 h after PH in rats treated with PDTC or PTX. At 24 h after PH, DNA synthesis and PCNA expression were identical in treated and control rats and thus occurred irrespectively of the status of NF-kB activation at 0.5 h. Signal transducer and activator of transcription 3 （Stat3） acUvatJon was observed already 0.5 h after PH in saline, PDTC or PTX group and was similar to Stat3 activation in response to injection without PH. CONCLUSION： These data strongly suggest that （1） NF-kB p65/p50 DNA binding produced in response to PH is not a signal necessary to initiate the liver regeneration, （2） star3 activation is a stress response unrelated to the activation of NF-kB. In conclusion, NF-kB activation is not critically required for the process of liver regeneration after PH.展开更多
Objective This study aimed to investigate how macrophage migration inhibitory factor(MIF)regulates the interaction of signal transducer and activator of transcription 1(STAT1)with CD74,and affects colon cancer prolife...Objective This study aimed to investigate how macrophage migration inhibitory factor(MIF)regulates the interaction of signal transducer and activator of transcription 1(STAT1)with CD74,and affects colon cancer proliferation and invasion.Methods After transfecting MIF small interfering RNA into the SW480 cell line,the expression of STAT1 and CD74 mRNA was detected by qRT-PCR and western blotting.Transwell and MTT assays were performed to detect the colon cancer cell invasion and proliferation ability.Co-immunoprecipitation was used to detect the interaction between CD74 and STAT1 proteins in the treated and control groups.Results The cellular biological assays(MTT and Transwell)showed that the proliferation and invasion ability of colon cancer cells decreased after MIF knockdown;the results showed significant statistical difference(P<0.05).The results of the co-immunoprecipitation assay suggested that MIF knockdown in colon cancer cells could inhibit the binding of CD74 and STAT1 proteins;statistical difference was observed between the two groups(P<0.05).Conclusion MIF can increase the proliferation and invasion of colon cancer cells by promoting the combination of CD74 and STAT1.展开更多
Pancreatic cancer is ranked as the fourth leading cause of cancer-related mortality and is predicted to become the second leading cause of cancer-related death by 2030.The cause of this high mortality rate is due to p...Pancreatic cancer is ranked as the fourth leading cause of cancer-related mortality and is predicted to become the second leading cause of cancer-related death by 2030.The cause of this high mortality rate is due to pancreatic ductal adenocarcinoma’s rapid progression and metastasis,and development of drug resistance.Today,cancer immunotherapy is becoming a strong candidate to not only treat various cancers but also to combat against chemoresistance.Studies have suggested that complement system pathways play an important role in cancer progression and chemoresistance,especially in pancreatic cancer.A recent report also suggested that several signaling pathways play an important role in causing chemoresistance in pancreatic cancer,major ones including nuclear factor kappa B,signal transducer and activator of transcription 3,c-mesenchymal-epithelial transition factor,and phosphoinositide-3-kinase/protein kinase B.In addition,it has also been proven that the complement system has a very active role in establishing the tumor microenvironment,which would aid in promoting tumorigenesis,progression,metastasis,and recurrence.Interestingly,it has been shown that the downstream products of the complement system directly upregulate inflammatory mediators,which in turn activate these chemo-resistant pathways.Therefore,targeting complement pathways could be an innovative approach to combat against pancreatic cancer drugs resistance.In this review,we have discussed the role of complement system pathways in pancreatic cancer drug resistance and a special focus on the complement as a therapeutic target in pancreatic cancer.展开更多
Aim Inducible nitric oxide synthase （iNOS） makes a great contribution to host defense and inflamma-tion. In many settings, lipopolysaccharide （LPS） induces iNOS expression through activation of the inhibitor of K...Aim Inducible nitric oxide synthase （iNOS） makes a great contribution to host defense and inflamma-tion. In many settings, lipopolysaccharide （LPS） induces iNOS expression through activation of the inhibitor of KB- α （IKB-α） -nuclear factor-KB （NF-KB） cascade, whereas interferon-γ （IFN-γ） acts through Janus kinase （ JAK）- signal transducer and activator of transcription 1 （ STAT1 ） signals. Heat shock factor 1 （ HSF1 ）, a major regulator of heat shock protein transcription, has been shown to regulate the production of pro-inflammatory cytokines such as tumor necrosis factor-α（TNF-α） and interleukin-6 （IL-6）. But it remains obscure whether and how HSF1 affects iNOS induction. Methods Western blot was used to measure the protein expression. The mRNA level was meas- ured by real time-PCR. Silence of HSF1 was achieved by small interfering RNA. Nitric oxide （NO） content and NF-KB binding activity were assayed by commercial kits. Chromatin immunoprecipitation （CHIP） was used to measure the binding activity of NF-KB and STAT1 to iNOS promoters. Results HSF1 inhibition or knockdown pre- vented the LPS- and/or IFN-γ-stimulated iNOS protein expression in cultured microglia. HSF1 inhibition blocked iNOS mRNA transcription. These inhibitory effects of HSF1 inhibition on iNOS expression were confirmed in brain tissues from endotoxemic mice. Further analysis showed that HSF1 inhibition had no effect on IKB-α degradation and NF-KB or STAT1 phosphorylation in LPS/IFN-γ-stimulated cells. The nuclear transport of active NF-KB or STAT1 was also not affected by HSF1 inhibition. But HSF1 inhibition reduced the binding of NF-KB and STAT1 to their DNA elements. In addition, HSF1 inhibition reduced NF-KB and STAT1 bindings to iNOS promoter inside the LPS/IFN-γ-stimulated cells. Conclusions This preventing effect of HSF1 inhibition on iNOS mRNA transcription presents the necessary role of HSF1 in iNOS induction.展开更多
Objectives： To investigate the mechanism of Liuwei Dihuang Pill （六味地黄丸, LDP） in treating postmenopausal osteoporosis （PMOP） with Shen （Kidney） yin deficiency. Methods： In this study, 205 cases of PMOP wer...Objectives： To investigate the mechanism of Liuwei Dihuang Pill （六味地黄丸, LDP） in treating postmenopausal osteoporosis （PMOP） with Shen （Kidney） yin deficiency. Methods： In this study, 205 cases of PMOP were divided into the PMOP Shen-yin deficiency group （Group A）, PMOP Shen-yang deficiency group （Group B）, PMOP without Shen deficiency group （Group C）, and control group （Group N）. Real-time polymerase chain reaction （RT-PCR） and Western blot techniques were used to observe the effects of LDP treatment on the cardiotrophin-like cytokine factor 1 （CLCF1）, ankyrin repeat and SOCS box containing 1 （ASB1）, and proldneticin 2 （PROK2） genes and the Janus kinase/signal transducer and activator of transcription （JAK/STAT） signaling pathway. Results： The mRNA （P〈0.05） and protein （P〈0.01） expression levels of the CLCF1 gone in Group A were significantly lower than the corresponding levels in Group N. After LDP treatment for 3 months, the mRNA expression levels of the CLCF1 gone were obviously up-regulated （P〈0.01）. After 6-month treatment, the expression levels of CLCF1 mRNA and protein were significantly up-regulated （both P〈0.01）, and the average bone density of the top femur had significantly increased （P〈0.05）. In vitro, CLCF1 overexpression resulted in a significant increase in the total protein and phosphorylated protein levels of JAK2 and STAT3. Conclusions： The CLCF1 gone is an important gone associated with PMOP Shen-yin deficiency and the therapeutic effects of LDP may be mediated by up-regulation of CLCF1 gone expression and activation of the JAK/STAT signaling pathway.展开更多
Retroperitoneal operations, such as radical prostatectomy, often damage the cavernous nerve, resulting in a high incidence of erectile dysfunction. Although improved nerve-sparing techniques have reduced the incidence...Retroperitoneal operations, such as radical prostatectomy, often damage the cavernous nerve, resulting in a high incidence of erectile dysfunction. Although improved nerve-sparing techniques have reduced the incidence of nerve injury, and the administration of phosphodiesterase type 5 inhibitors has revolutionized the treatment of erectile dysfunction, this problem remains a considerable challenge. In recent years, scientists have focused on brain-derived neurotrophic factor and vascular endothelial growth factor in the treatment of cavernous nerve injury in rat models. Results showed that both compounds were capable of enhancing the regeneration of the cavernous nerve and that activation of the Janus kinase （JAK）/signal transducer and activator of transcription （STAT） pathway played a major role in the process.展开更多
Numerous experimental and clinical studies indicate that chronic inflammation is closely related to the initiation, progression,and spread of cancer, in which proinflammatory cytokines, such as interleukin(IL)-6, IL-1...Numerous experimental and clinical studies indicate that chronic inflammation is closely related to the initiation, progression,and spread of cancer, in which proinflammatory cytokines, such as interleukin(IL)-6, IL-1β, and tumor necrosis factor-α(TNF-α), and transcription factors, such as nuclear factor-κB(NF-κB), and signal transducer and activator of transcription 3(STAT3), play pivotal roles. Stimulated by proinflammatory cytokines, NF-κB and STAT3 can modulate the expression of target genes, most of which are oncogenic ones, and promote the survival, proliferation, invasion, and metastasis of cancer cells. Now it is generally accepted that inflammation-related molecules and pathways are useful targets for the prevention and treatment of cancer. In this review, we summarize the relationship between chronic inflammation and cancer and describe some potentially useful agents including aspirin, meformin, statins, and some natural products(green tea catechins, andrographolide,curcumin) for their cancer prevention and treatment activities targeting chronic inflammation. The results of typical clinical studies are included, and the influences of these agents on the proinflammatory cytokines and inflammation-related pathways are discussed. Data from the present review support that agents targeting chronic inflammation may have a broad application prospect for the prevention and treatment of cancer in the future.展开更多
基金Supported by the grants from the National Natural Science Foundation of China, No. 30571833the Natural Science Foundation of Guangdong Province, China, No. 05001785
文摘AIM： To investigate the effect of （-）-epigallocatechin-3-gallate （EGCG） on growth of gastric cancer and its possible mechanism. METHODS： Heterotopic tumors were induced by subcutaneously injection of SGC-7901 cells in nude mice. Tumor growth was measured by calipers in two dimensions. Tumor angiogenesis was determined with tumor microvessel density （MVD） by immunohistology. Vascular endothelial growth factor （VEGF） protein level and activation of signal transducer and activator of transcription 3 （Star3） were examined by Western blotting. VEGF mRNA expression was determined by RT-PCR and VEGF release in tumor culture medium by ELISA. VEGF-induced cell proliferation was studied by MTT assay, cell migration by gelatin modified Boyden chamber （Transwell） and in vitro angiogenesis by endothelial tube formation in Matrigel. RESULTS： Intraperitoneal injection of EGCG inhibited the growth of gastric cancer by 60.4%. MVD in tumor tissues treated with EGCG was markedly reduced. EGCG treatment reduced VEGF protein level in vitro and in vivo. Secretion and mRNA expression of VEGF in tumor cells were also suppressed by EGCG in a dose-dependent manner. This inhibitory effect was associated with reduced activation of Star3, but EGCG treatment did not change the total Star3 expression. EGCG also inhibited VEGF-induced endothelial cell proliferation, migration and tube formation. CONCLUSION： EGCG inhibits the growth of gastric cancer by reducing VEGF production and angiogenesis, and is a promising candidate for anti-angiogenic treatment of gastric cancer.
基金Supported by National Natural Science Foundation of China, Grant, No. 30571833Natural Science Foundation of Guangdong Province, 05001785China Postdoctoral Science Foundation 20100470963
文摘AIM: To demonstrate that (-)-Epigallocatechin-3-gallate (EGCG) inhibits vascular endothelial growth factor (VEGF) expression and angiogenesis induced by interleukin-6 (IL-6) via suppressing signal transducer and activator of transcription 3 (Stat3) activity in gastric cancer. METHODS: Human gastric cancer (AGS) cells were treated with IL-6 (50 ng/mL) and EGCG at different concentrations. VEGF, total Stat3 and activated Stat3 protein levels in the cell lyses were examined by Western blotting, VEGF protein level in the conditionedmedium was measured by enzyme-linked immunosorbent assay, and the level of VEGF mRNA was evaluated by reverse transcription polymerase chain reaction (RTPCR). Stat3 nuclear translocation was determined by Western blotting with nuclear extract, and Stat3-DNA binding activity was examined with Chromatin immunoprecipitation (ChIP) assay. IL-6 induced endothelial cell proliferation was measured with 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazoliumbromide assay, in vitro angiogenesis was determined with endothelial cell tube formation assay in Matrigel, and IL-6-induced angiogenesis in vitro was measured with Matrigel plug assay. RESULTS: There was a basal expression and secretion of VEGF in AGS cells. After stimulation with IL-6, VEGF expression was apparently up-regulated and a 2.4-fold increase was observed. VEGF secretion in the conditioned medium was also increased by 2.8 folds. When treated with EGCG, VEGF expression and secretion were dose-dependently decreased. IL-6 also increased VEGF mRNA expression by 3.1 folds. EGCG treatment suppressed VEGF mRNA expression in a dose-dependent manner. EGCG dose-dependently inhibited Stat3 activation induced by IL-6, but did not change the total Stat3 expression. When treated with EGCG or AG490, VEGF expressions were reduced to the level or an even lower level in the tumor cells not stimulated with IL-6. However, PD98059 and LY294002 did not change VEGF expression induced by IL-6. EGCG inhibited Stat3 nucleus translocation, and Stat3-DNA bindi
基金Supported by A fellowship from the Daiichi Sankyo Foundation of Life Science,to Nakagawa H
文摘It has been established that cancer can be promoted and exacerbated by inflammation.Hepatocellular carcinoma(HCC) is the fifth most common cancer worldwide,and its long-term prognosis remains poor.Although HCC is a complex and heterogeneous tumor with several genomic mutations,it usually develops in the context of chronic liver damage and inflammation,suggesting that understanding the mechanism(s) of inflammation-mediated hepatocarcinogenesis is essential for the treatment and prevention of HCC.Chronic liver damage induces a persistent cycle of necroinflammation and hepatocyte regeneration,resulting in genetic mutations in hepatocytes and expansion of initiated cells,eventually leading to HCC development.Recently,several inflammation-and stress-related signaling pathways have been identified as key players in these processes,which include the nuclear factor B,signal transducer and activator of transcription,and stress-activated mitogen-activated protein kinase pathways.Although these pathways may suggest potential therapeutic targets,they have a wide range of functions and complex crosstalk occurs among them.This review focuses on recent advances in our understanding of the roles of these signaling pathways in hepatocarcinogenesis.
文摘AIM: To investigate the dynamic expression of p-signal transducer and activator of transcription 3 (STAT3) and vascular endothelial growth factor (VEGF) in the formation of gastric tumors induced by drinking water containing N-methyl-N’-nitro-N-nitrosoguanidine (MNNG) in Wistar rats. METHODS: One hundred and twenty Wistar rats were randomly divided into two groups (60 in each group): Control group and Model group. The rats in each group were then randomly divided into three groups (20 in each group): C/M15, C/M25 and C/M40 (15, 25 and 40 represent the number of feeding weeks from termination). Rats in the control group received normal drinking water and rats in the model group received drinking water containing 100 μg/mL MNNG. Stomach tissues were collected at the end of the 15<sup>th</sup>, 25<sup>th</sup> and 40<sup>th</sup> week, respectively, for microscopic measurement using hematoxylin and eosin staining. The expression of p-STAT3 and VEGF in different pathological types of gastric tissue, including normal, inflammation, atrophy, hyperplasia and gastric stromal tumor, was observed by immunohistochemistry and Western blot, and the corelation between p-STAT3 and VEGF was analyzed. RESULTS: (1) The expression of p-STAT3 in tissue with gastritis, atrophy, dysplasia and gastric stromal tumor were significantly increased in the model group compared with the control group (2.5 ± 1.0, 2.75 ± 0.36, 6.2 ± 0.45, 5.67 ± 0.55 vs 0.75 ± 0.36, P = 0.026, 0.035, 0.001, 0.002, respectively); the expression of p-STAT3 in tissue with dysplasia was higher than that in samples with gastritis or atrophy (6.2 ± 0.45 vs 2.5 ± 1.0, P = 0.006; 6.2 ± 0.45 vs 2.75 ± 0.36, P = 0.005, respectively); however, the expression of p-STAT3 in gastritis and atrophy was not significantly different (P > 0.05); (2) the expression of VEGF in tissue with gastritis, atrophy, dysplasia and gastric stromal tumor was significantly increased in the model group compared with normal g
文摘Signaling pathways of gastric carcinogenesis and gastric cancer progression are being avidly studied to seek optimal treatment of gastric cancer. Among them, hepatocyte growth factor (HGF)/c-MET, phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) and janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) pathways have been widely investigated. Their aberrant expression or mutation has been significantly associated with advanced stage or poor prognosis of gastric cancer. Recently, aberrations of immune checkpoints including programmed cell death-1/programmed cell death ligand-1 (PD-1/PD-L1) have been suggested as an important step in the formation of a microenvironment favorable for gastric cancer. Accomplishments in basic research have led to the development of novel agents targeting these signaling pathways. However, phase III studies of selective anti-HGF/c-MET antibodies and mTOR inhibitor failed to show significant benefits in terms of overall survival and progression-free survival. Few agents directly targeting STAT3 have been developed. However, this target is still critical issue in terms of chemoresistance, and SH2-containing protein tyrosine phosphatase 1 might be a significant link to effectively inhibit STAT3 activity. Inhibition of PD-1/PD-L1 showed durable efficacy in phase I studies, and phase III evaluation is warranted. Therapeutic strategy to concurrently inhibit multiple tyrosine kinases is a reasonable option, however, lapatinib needs to be further evaluated to identify good responders. Regorafenib has shown promising effectiveness in prolonging progression-free survival in a phase II study. In this topic highlight, we review the biologic roles and outcomes of clinical studies targeting these signaling pathways.
基金Supported by Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme (No.GDHVPS2018)Young Elite Scientists Sponsorship Program by the China Association of Chinese Medicine (No.2019-QNRC2-C14)。
文摘Objective:To explore the anti-inflammatory effects of ethyl lithospermate in lipopolysaccharide(LPS)-stimulated RAW 264.7 murine-derived macrophages and zebrafish,and its underlying mechanisms.Methods:3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazoliumbromide(MTT)assays were performed to investigate the toxicity of ethyl lithospermate at different concentrations(12.5–100μmol/L)in RAW 264.7 cells.The cells were stimulated with LPS(100 ng/mL)for 12 h to establish an inflammation model in vitro,the production of proinflammatory cytokines interleukin(IL)-6 and tumor necrosis factorα(TNF-α)were assessed by enzyme linked immunosorbent assay(ELISA).Western blot was used to ascertain the protein expressions of signal transducer and activator of transcription 3(STAT3),nuclear factor kappa B(NF-κB)p65,phospho-STAT3(p-STAT3,Tyr705),inhibitor of NF-κB(IκB)α,and phospho-IκBα(p-IκBα,Ser32),and confocal imaging was used to identify the nuclear translocation of NF-κB p65 and p-STAT3(Tyr705).Additionally,the yolk sacs of zebrafish(3 days post fertilization)were injected with 2 nL LPS(0.5 mg/mL)to induce an inflammation model in vivo.Survival analysis,hematoxylin-eosin(HE)staining,observation of neutrophil migration,and quantitative real-time polymerase chain reaction(qR T-PCR)were used to further study the anti-inflammatory effects of ethyl lithospermate and its probable mechanisms in vivo.Results:The non-toxic concentrations of ethyl lithospermate have been found to range from 12.5 to 100μmol/L.Ethyl lithospermate inhibited the release of IL-6 and TNF-α(P<0.05 or P<0.01),decreased IκBαdegradation and phosphorylation(P<0.05)as well as the nuclear translocation of NF-κB p65 and p-STAT3(Tyr705)in LPS-induced RAW 264.7 cells(P<0.01).Ethyl lithospermate also decreased inflammatory cells infiltration and neutrophil migration while increasing the survival rate of LPS-stimulated zebrafish(P<0.05 or P<0.01).In addition,ethyl lithospermate also inhibited the mR NA expression levels of of IL-6,TNF-α,IκBα,STAT3,and NF
基金Supported by a grant from Glaxo-Smithkline, Belgium, a grant from Astra Zeneca, Belgium, and a grant (3-4598) of FRSM,Belgium
文摘AIM： To analyze the effects of NF-kB inhibition by antioxidant pyrrolidine dithiocarbamate （PDTC） or TNF inhibitor pentoxifylline （PTX） on liver regeneration after partial hepatectomy （PH）. METHODS： Saline, PDTC or PTX were injected 1 h before PH and rats were killed at 0.5 and 24 h after PH. Several control groups were used for comparison （injection control groups）. RESULTS： Compared to saline injected controls, NF-kB activation was absent 0.5 h after PH in rats treated with PDTC or PTX. At 24 h after PH, DNA synthesis and PCNA expression were identical in treated and control rats and thus occurred irrespectively of the status of NF-kB activation at 0.5 h. Signal transducer and activator of transcription 3 （Stat3） acUvatJon was observed already 0.5 h after PH in saline, PDTC or PTX group and was similar to Stat3 activation in response to injection without PH. CONCLUSION： These data strongly suggest that （1） NF-kB p65/p50 DNA binding produced in response to PH is not a signal necessary to initiate the liver regeneration, （2） star3 activation is a stress response unrelated to the activation of NF-kB. In conclusion, NF-kB activation is not critically required for the process of liver regeneration after PH.
文摘Objective This study aimed to investigate how macrophage migration inhibitory factor(MIF)regulates the interaction of signal transducer and activator of transcription 1(STAT1)with CD74,and affects colon cancer proliferation and invasion.Methods After transfecting MIF small interfering RNA into the SW480 cell line,the expression of STAT1 and CD74 mRNA was detected by qRT-PCR and western blotting.Transwell and MTT assays were performed to detect the colon cancer cell invasion and proliferation ability.Co-immunoprecipitation was used to detect the interaction between CD74 and STAT1 proteins in the treated and control groups.Results The cellular biological assays(MTT and Transwell)showed that the proliferation and invasion ability of colon cancer cells decreased after MIF knockdown;the results showed significant statistical difference(P<0.05).The results of the co-immunoprecipitation assay suggested that MIF knockdown in colon cancer cells could inhibit the binding of CD74 and STAT1 proteins;statistical difference was observed between the two groups(P<0.05).Conclusion MIF can increase the proliferation and invasion of colon cancer cells by promoting the combination of CD74 and STAT1.
文摘Pancreatic cancer is ranked as the fourth leading cause of cancer-related mortality and is predicted to become the second leading cause of cancer-related death by 2030.The cause of this high mortality rate is due to pancreatic ductal adenocarcinoma’s rapid progression and metastasis,and development of drug resistance.Today,cancer immunotherapy is becoming a strong candidate to not only treat various cancers but also to combat against chemoresistance.Studies have suggested that complement system pathways play an important role in cancer progression and chemoresistance,especially in pancreatic cancer.A recent report also suggested that several signaling pathways play an important role in causing chemoresistance in pancreatic cancer,major ones including nuclear factor kappa B,signal transducer and activator of transcription 3,c-mesenchymal-epithelial transition factor,and phosphoinositide-3-kinase/protein kinase B.In addition,it has also been proven that the complement system has a very active role in establishing the tumor microenvironment,which would aid in promoting tumorigenesis,progression,metastasis,and recurrence.Interestingly,it has been shown that the downstream products of the complement system directly upregulate inflammatory mediators,which in turn activate these chemo-resistant pathways.Therefore,targeting complement pathways could be an innovative approach to combat against pancreatic cancer drugs resistance.In this review,we have discussed the role of complement system pathways in pancreatic cancer drug resistance and a special focus on the complement as a therapeutic target in pancreatic cancer.
文摘Aim Inducible nitric oxide synthase （iNOS） makes a great contribution to host defense and inflamma-tion. In many settings, lipopolysaccharide （LPS） induces iNOS expression through activation of the inhibitor of KB- α （IKB-α） -nuclear factor-KB （NF-KB） cascade, whereas interferon-γ （IFN-γ） acts through Janus kinase （ JAK）- signal transducer and activator of transcription 1 （ STAT1 ） signals. Heat shock factor 1 （ HSF1 ）, a major regulator of heat shock protein transcription, has been shown to regulate the production of pro-inflammatory cytokines such as tumor necrosis factor-α（TNF-α） and interleukin-6 （IL-6）. But it remains obscure whether and how HSF1 affects iNOS induction. Methods Western blot was used to measure the protein expression. The mRNA level was meas- ured by real time-PCR. Silence of HSF1 was achieved by small interfering RNA. Nitric oxide （NO） content and NF-KB binding activity were assayed by commercial kits. Chromatin immunoprecipitation （CHIP） was used to measure the binding activity of NF-KB and STAT1 to iNOS promoters. Results HSF1 inhibition or knockdown pre- vented the LPS- and/or IFN-γ-stimulated iNOS protein expression in cultured microglia. HSF1 inhibition blocked iNOS mRNA transcription. These inhibitory effects of HSF1 inhibition on iNOS expression were confirmed in brain tissues from endotoxemic mice. Further analysis showed that HSF1 inhibition had no effect on IKB-α degradation and NF-KB or STAT1 phosphorylation in LPS/IFN-γ-stimulated cells. The nuclear transport of active NF-KB or STAT1 was also not affected by HSF1 inhibition. But HSF1 inhibition reduced the binding of NF-KB and STAT1 to their DNA elements. In addition, HSF1 inhibition reduced NF-KB and STAT1 bindings to iNOS promoter inside the LPS/IFN-γ-stimulated cells. Conclusions This preventing effect of HSF1 inhibition on iNOS mRNA transcription presents the necessary role of HSF1 in iNOS induction.
基金Supported by National Natural Science Foundation of China(Nos.81173280,81302995,81403420)Fujian Medical Innovation project(No.2011-CX-30)+1 种基金Science and Technology Department of Fujian Province autonomous non-profit research institutes topics project(No.2011R1038-5)Fujian Academy of Traditional Chinese autonomous topics Project(No.2012fjzyyk-5)
文摘Objectives： To investigate the mechanism of Liuwei Dihuang Pill （六味地黄丸, LDP） in treating postmenopausal osteoporosis （PMOP） with Shen （Kidney） yin deficiency. Methods： In this study, 205 cases of PMOP were divided into the PMOP Shen-yin deficiency group （Group A）, PMOP Shen-yang deficiency group （Group B）, PMOP without Shen deficiency group （Group C）, and control group （Group N）. Real-time polymerase chain reaction （RT-PCR） and Western blot techniques were used to observe the effects of LDP treatment on the cardiotrophin-like cytokine factor 1 （CLCF1）, ankyrin repeat and SOCS box containing 1 （ASB1）, and proldneticin 2 （PROK2） genes and the Janus kinase/signal transducer and activator of transcription （JAK/STAT） signaling pathway. Results： The mRNA （P〈0.05） and protein （P〈0.01） expression levels of the CLCF1 gone in Group A were significantly lower than the corresponding levels in Group N. After LDP treatment for 3 months, the mRNA expression levels of the CLCF1 gone were obviously up-regulated （P〈0.01）. After 6-month treatment, the expression levels of CLCF1 mRNA and protein were significantly up-regulated （both P〈0.01）, and the average bone density of the top femur had significantly increased （P〈0.05）. In vitro, CLCF1 overexpression resulted in a significant increase in the total protein and phosphorylated protein levels of JAK2 and STAT3. Conclusions： The CLCF1 gone is an important gone associated with PMOP Shen-yin deficiency and the therapeutic effects of LDP may be mediated by up-regulation of CLCF1 gone expression and activation of the JAK/STAT signaling pathway.
文摘Retroperitoneal operations, such as radical prostatectomy, often damage the cavernous nerve, resulting in a high incidence of erectile dysfunction. Although improved nerve-sparing techniques have reduced the incidence of nerve injury, and the administration of phosphodiesterase type 5 inhibitors has revolutionized the treatment of erectile dysfunction, this problem remains a considerable challenge. In recent years, scientists have focused on brain-derived neurotrophic factor and vascular endothelial growth factor in the treatment of cavernous nerve injury in rat models. Results showed that both compounds were capable of enhancing the regeneration of the cavernous nerve and that activation of the Janus kinase （JAK）/signal transducer and activator of transcription （STAT） pathway played a major role in the process.
基金supported by the National Natural Science Foundation of China(91329000&91129000)
文摘Numerous experimental and clinical studies indicate that chronic inflammation is closely related to the initiation, progression,and spread of cancer, in which proinflammatory cytokines, such as interleukin(IL)-6, IL-1β, and tumor necrosis factor-α(TNF-α), and transcription factors, such as nuclear factor-κB(NF-κB), and signal transducer and activator of transcription 3(STAT3), play pivotal roles. Stimulated by proinflammatory cytokines, NF-κB and STAT3 can modulate the expression of target genes, most of which are oncogenic ones, and promote the survival, proliferation, invasion, and metastasis of cancer cells. Now it is generally accepted that inflammation-related molecules and pathways are useful targets for the prevention and treatment of cancer. In this review, we summarize the relationship between chronic inflammation and cancer and describe some potentially useful agents including aspirin, meformin, statins, and some natural products(green tea catechins, andrographolide,curcumin) for their cancer prevention and treatment activities targeting chronic inflammation. The results of typical clinical studies are included, and the influences of these agents on the proinflammatory cytokines and inflammation-related pathways are discussed. Data from the present review support that agents targeting chronic inflammation may have a broad application prospect for the prevention and treatment of cancer in the future.
