Summary： Senescence is an important obstacle to cancer development. Engaging a senescent response may be an effective way to cure acute myeloid leukemia （AML）. The aim of this study was to examine the effect of res...Summary： Senescence is an important obstacle to cancer development. Engaging a senescent response may be an effective way to cure acute myeloid leukemia （AML）. The aim of this study was to examine the effect of resveratrol-downregulated phosphorylated liver kinase B1 （pLKB1） on the senescence of acute myeloid leukemia （AML） stem cells. The protein expressions of pLKB 1 and Sirtuin 1 （SIRT1）, a regulator ofpLKB1, were measured in CD34＋CD38-KGla cells treated with resveratrol （40 μmol/L） or not by Western blotting. Senescence-related factors were examined, including p21 mRNA tested by real-time PCR, cell morphology by senescence-associated β-galactosidase （SA-β-gal） staining, cell pro- liferation by MTT assay and cell cycle by flow cytometry. Besides, apoptosis was flow cytometrically determined. The results showed that pLKB1 was highly expressed in CD34＋CD38- KGla cells, and resveratrol, which could downregulate pLKB1 through activation of SIRT1, induced senescence and apoptosis of CD34＋CD38- KGla cells. It was concluded that resveratrol-downregulated pLKB1 is in- volved in the senescence of AML stem cells.展开更多
AIM： To study the relationship between interleukin-lbeta （IL-1β） up-regulating tissue inhibitor of matrix metalloproteinase-1 （TIMMP-1） mRNA expression and phosphorylation of both c-jun N-terminal kinase （INK）...AIM： To study the relationship between interleukin-lbeta （IL-1β） up-regulating tissue inhibitor of matrix metalloproteinase-1 （TIMMP-1） mRNA expression and phosphorylation of both c-jun N-terminal kinase （INK） and p38 in rat heffatic stellate cells （HSC）. METHODS： RT-PCR was performed to measure the expression of TIMMP-1 mRNA in rat HSC. Western blot was performed to measure IL-1β-induced JNK and p38 activities in rat HSC. RESULTS： TIMMP-1 mRNA expression （1.191± 0.079） was much higher after treatment with IL-1β （10 ng/mL） for 24 h than in control group （0.545±0.091） （P〈0.01）. IL-1β activated INK and p38 in a time-dependent manner. After stimulation with IL-1β for 0, 5, 15, 30, 60 and 120 min, the INK activity was 0.982±0.299, 1.501±0.720, 2.133±0.882, 3.360±0.452, 2.181±0.789, and 1.385 ± 0.368, respectively. There was a significant difference in JNK activity at 15 min （P〈 0.01）, 30 min （P〈 0.01） and 60 min （P〈0.01） in comparison to that at 0 min. The p38 activity was 1.061±0.310, 2.050±0.863, 2.380±0.573, 2.973±0.953, 2.421±0.793, and 1.755 ± 0.433 at the 6 time points （0, 5, 15, 30, 60 and 120 min） respectively. There was a significant difference in p38 activity at 5 min （P〈0.05）, 15 min （P〈0.01）, 30 min （P〈0.01） and 60 min （P〈0.01） compared to that at 0 min. TIMMP-1 mRNA expression trended to decrease in 3 groups pretreated with different concentrations of SP600125 （10 μmol/L, 1.022±0.113; 20 μmol/L, 0.869±0.070; 40 μmol/L, 0.666±0.123）. Their decreases were all significant （P〈0.05, P〈0.01, P〈0.01） in comparison to control group （without SP600125 treatment, 1.163±0.107）. In the other 3 groups pretreated with different concentrations of SB203580 （10 μmol/L, 1.507±0.099; 20 μmol/L, 1.698±0.107; 40 μmol/L, 1.857±0.054）, the expression of TIMMP-1 mRNA increased. Their levels were higher than those in the control group （without SB203580 treatment, 1.027 ± 0.061） with a significant statistical significance （P〈 0.01）. CONCLUSION： IL-1β has a direct action on hepatic fibrosis by up-regulating TIMMP-1 mRNA expression in ratessionin in rate HSC.JNK and p38 mitogen-activated protein kinases （MAPKs） are involved in IL-1β-induced TIMMP-1 gene expression, and play a distinct role in this process, indicating that p38 and .INK pathways cooperatively mediate TIMP-1 mRNA expression in rat HSC.展开更多
AIM: To investigate the role of protein kinase C(PKC)-δ activation in the pathogenesis of acute liver failure(ALF) in a well-characterized mouse model of D-galactosamine(D-Gal N)/lipopolysaccharide(LPS)-induced ALF.M...AIM: To investigate the role of protein kinase C(PKC)-δ activation in the pathogenesis of acute liver failure(ALF) in a well-characterized mouse model of D-galactosamine(D-Gal N)/lipopolysaccharide(LPS)-induced ALF.METHODS: BALB/c mice were randomly assigned to five groups, and ALF was induced in mice by intraperitoneal injection of D-Ga IN(600 mg/kg) and LPS(10 μg/kg). Kaplan-Meier method was used for survival analysis. Serum alanine aminotransferase(ALT) and aspartate aminotransferase(AST) levels at different time points within one week were determined using a multiparameteric analyzer. Serum levels of high-mobility group box 1(HMGB1), tumor necrosis factor(TNF)-α, interleukin(IL)-1β, IL-6, and IL-10 as well as nuclear factor(NF)-κB activity were determined by enzyme-linked immunosorbent assay. Hepatic morphological changes at 36 h after ALF induction were assessed by hematoxylin and eosin staining. Expression of PKC-δ in liver tissue and peripheral blood mononuclear cells(PBMCs) was analyzed by Western blot.RESULTS: The expression and activation of PKC-δ were up-regulated in liver tissue and PBMCs of mice with D-Gal N/LPS-induced ALF. Inhibition of PKC-δ activation with rottlerin significantly increased the survival rates and decreased serum ALT/AST levels at 6, 12 and 24 h compared with the control group(P < 0.001). Rottlerin treatment also significantly decreased serum levels of HMGB1 at 6, 12, and 24 h, TNF-α, IL-6 and IL-1 β at 12 h compared with the control group(P < 0.01). The inflammatory cell infiltration and necrosis in liver tissue were also decreased in the rottlerin treatment group. Furthermore, sphingosine kinase 1(Sph K1) dependent PKC-δ activation played an important role in promoting NF-κB activation and inflammatory cytokine production in ALF.CONCLUSION: Sph K1 dependent PKC-δ activation plays an important role in promoting NF-κB activation and inflammatory response in ALF, and inhibition of PKC-δ activation might be a potential therapeutic strategy for this disease.展开更多
目的:主要研究乙肝病毒(hepatitis B virus,HBV)感染肝细胞后,细胞周期激酶2(cyclin-dependent kinase 2,CDK2)调控宿主限制性因子SAMHD1(sterile alpha motif and histidine/aspartic acid domain-containing protein 1)磷酸化的分子...目的:主要研究乙肝病毒(hepatitis B virus,HBV)感染肝细胞后,细胞周期激酶2(cyclin-dependent kinase 2,CDK2)调控宿主限制性因子SAMHD1(sterile alpha motif and histidine/aspartic acid domain-containing protein 1)磷酸化的分子机制。方法:利用si RNA干扰技术,特异性处理肝癌细胞Huh7.0的对照组、干扰CDK1组和干扰CDK2组,分别用Southern blot检测这3组中乙肝病毒复制的变化,Western blot检测这3组中SAMHD1磷酸化水平的变化,流式细胞仪检测这3组中细胞周期的变化;进一步通过免疫共沉淀技术鉴定肝癌细胞中CDK2激酶和SAMHD1的相互作用。结果:在肝癌细胞Huh7.0中,与对照组相比,干扰CDK1组和干扰CDK2组的细胞周期明显有差异,分别停滞在G_2期(P=0.001)或G1期(P=0.001)。Western blot结果表明,干扰CDK2后,宿主限制性因子SAMHD1磷酸化水平下降48%,Southern blot结果表明病毒复制水平降低57%(P=0.003),而干扰CDK1后病毒复制水平没有明显变化(P=0.325)进一步通过免疫共沉淀发现在肝癌细胞Huh7.0中,CDK2激酶可与SAMHD1发生相互作用,并且相互作用发生在细胞核内。结论:HBV感染肝细胞后,募集CDK2调控宿主限制性因子SAMHD1的磷酸化,拮抗其抗病毒作用。展开更多
Lung cancer is featured with high mortality,with a 15%five-year survival rate worldwide.Genetic alterations,such as loss of function of tumor suppressor genes,frequently contribute to lung cancer initiation,progressio...Lung cancer is featured with high mortality,with a 15%five-year survival rate worldwide.Genetic alterations,such as loss of function of tumor suppressor genes,frequently contribute to lung cancer initiation,progression and metastasis.Liver kinase B1(LKB1),as a serine/threonine kinase and tumor suppressor,is frequently mutated and inactivated in non-small cell lung cancer(NSCLC).Recent studies have provided strong evidences that LKB1 loss promotes lung cancerigenesis process,especially lung cancer progression and metastasis.This review will summarize recent progress on how LKB1 modulates the process of lung cancerigenesis,emphasizing on LKB1 downstream signaling pathways and biological functions.We will further discuss the potential development of prognostic biomarkers or therapeutic targets in lung cancer clinic based on the molecular alteration associated with deregulated LKB1 signaling.展开更多
The high prevalence and mortality of lung cancer, together with a poor 5-year survival of only approximately 15%, emphasize the need for prognostic and predictive factors to improve patient treatment. C4.4A, a member ...The high prevalence and mortality of lung cancer, together with a poor 5-year survival of only approximately 15%, emphasize the need for prognostic and predictive factors to improve patient treatment. C4.4A, a member of the Ly6/uP AR family of membrane proteins, qualifies as such a potential informative biomarker in non-small cell lung cancer. Under normal physiological conditions, it is primarily expressed in suprabasal layers of stratified squamous epithelia. Consequently, it is absent from healthy bronchial and alveolar tissue, but nevertheless appears at early stages in the progression to invasivecarcinomas of the lung, i.e., in bronchial hyperplasia/metaplasia and atypical adenomatous hyperplasia. In the stages leading to pulmonary squamous cell carcinoma, expression is sustained in dysplasia, carcinoma in situ and invasive carcinomas, and this pertains to the normal presence of C4.4A in squamous epithelium. In pulmonary adenocarcinomas, a fraction of cases is positive for C4.4A, which is surprising, given the origin of these carcinomas from mucin-producing and not squamous epithelium. Interestingly, this correlates with a highly compromised patient survival and a predominant solid tumor growth pattern. Circumstantial evidence suggests an inverse relationship between C4.4A and the tumor suppressor LKB1. This might provide a link to the prognostic impact of C4.4A in patients with adenocarcinomas of the lung and could potentially be exploited for predicting the efficacy of treatment targeting components of the LKB1 pathway.展开更多
基金supported by grants from the National Natural Science Foundation of China(Nos.81370660,81170524)
文摘Summary： Senescence is an important obstacle to cancer development. Engaging a senescent response may be an effective way to cure acute myeloid leukemia （AML）. The aim of this study was to examine the effect of resveratrol-downregulated phosphorylated liver kinase B1 （pLKB1） on the senescence of acute myeloid leukemia （AML） stem cells. The protein expressions of pLKB 1 and Sirtuin 1 （SIRT1）, a regulator ofpLKB1, were measured in CD34＋CD38-KGla cells treated with resveratrol （40 μmol/L） or not by Western blotting. Senescence-related factors were examined, including p21 mRNA tested by real-time PCR, cell morphology by senescence-associated β-galactosidase （SA-β-gal） staining, cell pro- liferation by MTT assay and cell cycle by flow cytometry. Besides, apoptosis was flow cytometrically determined. The results showed that pLKB1 was highly expressed in CD34＋CD38- KGla cells, and resveratrol, which could downregulate pLKB1 through activation of SIRT1, induced senescence and apoptosis of CD34＋CD38- KGla cells. It was concluded that resveratrol-downregulated pLKB1 is in- volved in the senescence of AML stem cells.
文摘AIM： To study the relationship between interleukin-lbeta （IL-1β） up-regulating tissue inhibitor of matrix metalloproteinase-1 （TIMMP-1） mRNA expression and phosphorylation of both c-jun N-terminal kinase （INK） and p38 in rat heffatic stellate cells （HSC）. METHODS： RT-PCR was performed to measure the expression of TIMMP-1 mRNA in rat HSC. Western blot was performed to measure IL-1β-induced JNK and p38 activities in rat HSC. RESULTS： TIMMP-1 mRNA expression （1.191± 0.079） was much higher after treatment with IL-1β （10 ng/mL） for 24 h than in control group （0.545±0.091） （P〈0.01）. IL-1β activated INK and p38 in a time-dependent manner. After stimulation with IL-1β for 0, 5, 15, 30, 60 and 120 min, the INK activity was 0.982±0.299, 1.501±0.720, 2.133±0.882, 3.360±0.452, 2.181±0.789, and 1.385 ± 0.368, respectively. There was a significant difference in JNK activity at 15 min （P〈 0.01）, 30 min （P〈 0.01） and 60 min （P〈0.01） in comparison to that at 0 min. The p38 activity was 1.061±0.310, 2.050±0.863, 2.380±0.573, 2.973±0.953, 2.421±0.793, and 1.755 ± 0.433 at the 6 time points （0, 5, 15, 30, 60 and 120 min） respectively. There was a significant difference in p38 activity at 5 min （P〈0.05）, 15 min （P〈0.01）, 30 min （P〈0.01） and 60 min （P〈0.01） compared to that at 0 min. TIMMP-1 mRNA expression trended to decrease in 3 groups pretreated with different concentrations of SP600125 （10 μmol/L, 1.022±0.113; 20 μmol/L, 0.869±0.070; 40 μmol/L, 0.666±0.123）. Their decreases were all significant （P〈0.05, P〈0.01, P〈0.01） in comparison to control group （without SP600125 treatment, 1.163±0.107）. In the other 3 groups pretreated with different concentrations of SB203580 （10 μmol/L, 1.507±0.099; 20 μmol/L, 1.698±0.107; 40 μmol/L, 1.857±0.054）, the expression of TIMMP-1 mRNA increased. Their levels were higher than those in the control group （without SB203580 treatment, 1.027 ± 0.061） with a significant statistical significance （P〈 0.01）. CONCLUSION： IL-1β has a direct action on hepatic fibrosis by up-regulating TIMMP-1 mRNA expression in ratessionin in rate HSC.JNK and p38 mitogen-activated protein kinases （MAPKs） are involved in IL-1β-induced TIMMP-1 gene expression, and play a distinct role in this process, indicating that p38 and .INK pathways cooperatively mediate TIMP-1 mRNA expression in rat HSC.
基金Supported by The National Natural Science Foundation of ChinaNo.81160065
文摘AIM: To investigate the role of protein kinase C(PKC)-δ activation in the pathogenesis of acute liver failure(ALF) in a well-characterized mouse model of D-galactosamine(D-Gal N)/lipopolysaccharide(LPS)-induced ALF.METHODS: BALB/c mice were randomly assigned to five groups, and ALF was induced in mice by intraperitoneal injection of D-Ga IN(600 mg/kg) and LPS(10 μg/kg). Kaplan-Meier method was used for survival analysis. Serum alanine aminotransferase(ALT) and aspartate aminotransferase(AST) levels at different time points within one week were determined using a multiparameteric analyzer. Serum levels of high-mobility group box 1(HMGB1), tumor necrosis factor(TNF)-α, interleukin(IL)-1β, IL-6, and IL-10 as well as nuclear factor(NF)-κB activity were determined by enzyme-linked immunosorbent assay. Hepatic morphological changes at 36 h after ALF induction were assessed by hematoxylin and eosin staining. Expression of PKC-δ in liver tissue and peripheral blood mononuclear cells(PBMCs) was analyzed by Western blot.RESULTS: The expression and activation of PKC-δ were up-regulated in liver tissue and PBMCs of mice with D-Gal N/LPS-induced ALF. Inhibition of PKC-δ activation with rottlerin significantly increased the survival rates and decreased serum ALT/AST levels at 6, 12 and 24 h compared with the control group(P < 0.001). Rottlerin treatment also significantly decreased serum levels of HMGB1 at 6, 12, and 24 h, TNF-α, IL-6 and IL-1 β at 12 h compared with the control group(P < 0.01). The inflammatory cell infiltration and necrosis in liver tissue were also decreased in the rottlerin treatment group. Furthermore, sphingosine kinase 1(Sph K1) dependent PKC-δ activation played an important role in promoting NF-κB activation and inflammatory cytokine production in ALF.CONCLUSION: Sph K1 dependent PKC-δ activation plays an important role in promoting NF-κB activation and inflammatory response in ALF, and inhibition of PKC-δ activation might be a potential therapeutic strategy for this disease.
基金the National Basic Research Program of China(Grant No.2010CB912102)the National Natural Science Foundation of China(Grant Nos.30871284,30971461 and 30971495)the Science and Technology Commission of Shanghai Municipality(No.09JC1416300)。
文摘Lung cancer is featured with high mortality,with a 15%five-year survival rate worldwide.Genetic alterations,such as loss of function of tumor suppressor genes,frequently contribute to lung cancer initiation,progression and metastasis.Liver kinase B1(LKB1),as a serine/threonine kinase and tumor suppressor,is frequently mutated and inactivated in non-small cell lung cancer(NSCLC).Recent studies have provided strong evidences that LKB1 loss promotes lung cancerigenesis process,especially lung cancer progression and metastasis.This review will summarize recent progress on how LKB1 modulates the process of lung cancerigenesis,emphasizing on LKB1 downstream signaling pathways and biological functions.We will further discuss the potential development of prognostic biomarkers or therapeutic targets in lung cancer clinic based on the molecular alteration associated with deregulated LKB1 signaling.
基金Supported by Copenhagen University Hospital(Rigshospitalets Forskningspuljer)The Danish National Research Foundation(Danish-Chinese Centre for Proteases and Cancer)Harboefonden,Torben og Alice Frimodts Fond,Fabrikant Einar Willumsens Mindelegat,Holger Rabitz and hustrus Legat,The Lundbeck Foundation.
文摘The high prevalence and mortality of lung cancer, together with a poor 5-year survival of only approximately 15%, emphasize the need for prognostic and predictive factors to improve patient treatment. C4.4A, a member of the Ly6/uP AR family of membrane proteins, qualifies as such a potential informative biomarker in non-small cell lung cancer. Under normal physiological conditions, it is primarily expressed in suprabasal layers of stratified squamous epithelia. Consequently, it is absent from healthy bronchial and alveolar tissue, but nevertheless appears at early stages in the progression to invasivecarcinomas of the lung, i.e., in bronchial hyperplasia/metaplasia and atypical adenomatous hyperplasia. In the stages leading to pulmonary squamous cell carcinoma, expression is sustained in dysplasia, carcinoma in situ and invasive carcinomas, and this pertains to the normal presence of C4.4A in squamous epithelium. In pulmonary adenocarcinomas, a fraction of cases is positive for C4.4A, which is surprising, given the origin of these carcinomas from mucin-producing and not squamous epithelium. Interestingly, this correlates with a highly compromised patient survival and a predominant solid tumor growth pattern. Circumstantial evidence suggests an inverse relationship between C4.4A and the tumor suppressor LKB1. This might provide a link to the prognostic impact of C4.4A in patients with adenocarcinomas of the lung and could potentially be exploited for predicting the efficacy of treatment targeting components of the LKB1 pathway.
