Poly-adenosine diphosphate ribose polymerase inhibitors(PARPi)lead to synthetic lethality when used in cancers harbouring a BRCA mutation or homologous recombination deficiency.There are now four PARPi approved by the...Poly-adenosine diphosphate ribose polymerase inhibitors(PARPi)lead to synthetic lethality when used in cancers harbouring a BRCA mutation or homologous recombination deficiency.There are now four PARPi approved by the Food and Drug Administration for therapeutic use is ovarian and breast cancer.In addition to this,there is data supporting its use in pancreatic adenocarcinoma and prostate cancer.However,development of resistance to PARPi limits the duration of response.Key mechanisms found to date include:(1)restoration of homologous recombination;(2)changes in PARP1;(3)suppression of non-homologous end joining;(4)replication fork protection;and(5)drug concentration.Gaining a better understanding of resistance mechanisms may guide combination therapies to overcome the resistance and improve the efficacy of PARPi.The purpose of this review is to describe the resistance mechanisms to PARPi and discuss their early detection.展开更多
Berberine(BBR) is a natural alkaloid isolated from the Coptis Chinensis.While this plant has been used in Ay-urvedic and Chinese medicine for more than 2500 years,interest in its effects in metabolic and cardiovascula...Berberine(BBR) is a natural alkaloid isolated from the Coptis Chinensis.While this plant has been used in Ay-urvedic and Chinese medicine for more than 2500 years,interest in its effects in metabolic and cardiovascular disease has been growing in the Western world in the last decade.Many papers have been published in these years reporting beneficial effects in carbohydrate and lip-id metabolism,endothelial function and the cardiovascu-lar system.In this review,we report a detailed analysis of the scientific literature regarding this topic,describing the effects and the underlying mechanisms of BBR on carbohydrate and lipid metabolism,endothelial function and the cardiovascular system.展开更多
AIM To investigate the effect of metformin on activated hepatic stellate cells(HSCs) and the possible signaling pathways involved. METHODS A fibrotic mouse model was generated by intraperitoneal injection of carbon te...AIM To investigate the effect of metformin on activated hepatic stellate cells(HSCs) and the possible signaling pathways involved. METHODS A fibrotic mouse model was generated by intraperitoneal injection of carbon tetrachloride(CCl_4) and subsequent treatment with or without metformin. The level of fibrosis was detected by hematoxylin-eosin staining, Sirius Red staining, and immunohistochemistry. The HSC cell line LX-2 was used for in vitro studies. The effect of metformin on cell proliferation(CCK8 assay),motility(scratch test and Transwell assay), contraction(collagen gel contraction assay), extracellular matrix(ECM) secretion(Western blot), and angiogenesis(ELISA and tube formation assay) was investigated. We also analyzed the possible signaling pathways involved by Western blot analysis.RESULTS Mice developed marked liver fibrosis after intraperitoneal injection with CCl_4 for 6 wk. Metformin decreased the activation of HSCs, reduced the deposition of ECM, and inhibited angiogenesis in CCl_4-treated mice. Platelet-derived growth factor(PDGF) promoted the fibrogenic response of HSCs in vitro, while metformin inhibited the activation, proliferation, migration, and contraction of HSCs, and reduced the secretion of ECM. Metformin decreased the expression of vascular endothelial growth factor(VEGF) in HSCs through inhibition of hypoxia inducible factor(HIF)-1α in both PDGF-BB treatment and hypoxic conditions, and it down-regulated VEGF secretion by HSCs and inhibited HSC-based angiogenesis in hypoxic conditions in vitro. The inhibitory effects of metformin on activated HSCs were mediated by inhibiting the Akt/mammalian target of rapamycin(m TOR) and extracellular signal-regulated kinase(ERK) pathways via the activation of adenosine monophosphate-activated protein kinase(AMPK).CONCLUSION Metformin attenuates the fibrogenic response of HSCs in vivo and in vitro, and may therefore be useful for the treatment of chronic liver diseases.展开更多
The adenosine monophosphate-activated protein kinase (AMPK) and p70 ribosomal S6 kinase-1 pathway may serve as a key signaling flow that regulates energy metabolism; thus, this pathway becomes an attractive target for...The adenosine monophosphate-activated protein kinase (AMPK) and p70 ribosomal S6 kinase-1 pathway may serve as a key signaling flow that regulates energy metabolism; thus, this pathway becomes an attractive target for the treatment of liver diseases that result from metabolic derangements. In addition, AMPK emerges as a kinase that controls the redox-state and mitochondrial function, whose activity may be modulated by antioxidants. A close link exists between fuel metabolism and mitochondrial biogenesis. The relationship between fuel metabolism and cell survival strongly implies the existence of a shared signaling network, by which hepatocytes respond to challenges of external stimuli. The AMPK pathway may belong to this network. A series of drugs and therapeutic candidates enable hepatocytes to protect mitochondria from radical stress and increase cell viability, which may be associated with the activation of AMPK, liver kinase B1, and other molecules or components. Consequently, the components downstream of AMPK may contribute to stabilizing mitochondrial membrane potential for hepatocyte survival. In this review, we discuss the role of the AMPK pathway in hepatic energy metabolism and hepatocyte viability. This information may help identify ways to prevent and/or treat hepatic diseases caused by the metabolic syndrome. Moreover, clinical drugs and experimental therapeutic candidates that directly or indirectly modulate the AMPK pathway in distinct manners are discussed here with particular emphasis on their effects on fuel metabolism and mitochondrial function.展开更多
文摘Poly-adenosine diphosphate ribose polymerase inhibitors(PARPi)lead to synthetic lethality when used in cancers harbouring a BRCA mutation or homologous recombination deficiency.There are now four PARPi approved by the Food and Drug Administration for therapeutic use is ovarian and breast cancer.In addition to this,there is data supporting its use in pancreatic adenocarcinoma and prostate cancer.However,development of resistance to PARPi limits the duration of response.Key mechanisms found to date include:(1)restoration of homologous recombination;(2)changes in PARP1;(3)suppression of non-homologous end joining;(4)replication fork protection;and(5)drug concentration.Gaining a better understanding of resistance mechanisms may guide combination therapies to overcome the resistance and improve the efficacy of PARPi.The purpose of this review is to describe the resistance mechanisms to PARPi and discuss their early detection.
文摘Berberine(BBR) is a natural alkaloid isolated from the Coptis Chinensis.While this plant has been used in Ay-urvedic and Chinese medicine for more than 2500 years,interest in its effects in metabolic and cardiovascular disease has been growing in the Western world in the last decade.Many papers have been published in these years reporting beneficial effects in carbohydrate and lip-id metabolism,endothelial function and the cardiovascu-lar system.In this review,we report a detailed analysis of the scientific literature regarding this topic,describing the effects and the underlying mechanisms of BBR on carbohydrate and lipid metabolism,endothelial function and the cardiovascular system.
基金Supported by National Natural Science Foundation of China,No.81370590
文摘AIM To investigate the effect of metformin on activated hepatic stellate cells(HSCs) and the possible signaling pathways involved. METHODS A fibrotic mouse model was generated by intraperitoneal injection of carbon tetrachloride(CCl_4) and subsequent treatment with or without metformin. The level of fibrosis was detected by hematoxylin-eosin staining, Sirius Red staining, and immunohistochemistry. The HSC cell line LX-2 was used for in vitro studies. The effect of metformin on cell proliferation(CCK8 assay),motility(scratch test and Transwell assay), contraction(collagen gel contraction assay), extracellular matrix(ECM) secretion(Western blot), and angiogenesis(ELISA and tube formation assay) was investigated. We also analyzed the possible signaling pathways involved by Western blot analysis.RESULTS Mice developed marked liver fibrosis after intraperitoneal injection with CCl_4 for 6 wk. Metformin decreased the activation of HSCs, reduced the deposition of ECM, and inhibited angiogenesis in CCl_4-treated mice. Platelet-derived growth factor(PDGF) promoted the fibrogenic response of HSCs in vitro, while metformin inhibited the activation, proliferation, migration, and contraction of HSCs, and reduced the secretion of ECM. Metformin decreased the expression of vascular endothelial growth factor(VEGF) in HSCs through inhibition of hypoxia inducible factor(HIF)-1α in both PDGF-BB treatment and hypoxic conditions, and it down-regulated VEGF secretion by HSCs and inhibited HSC-based angiogenesis in hypoxic conditions in vitro. The inhibitory effects of metformin on activated HSCs were mediated by inhibiting the Akt/mammalian target of rapamycin(m TOR) and extracellular signal-regulated kinase(ERK) pathways via the activation of adenosine monophosphate-activated protein kinase(AMPK).CONCLUSION Metformin attenuates the fibrogenic response of HSCs in vivo and in vitro, and may therefore be useful for the treatment of chronic liver diseases.
基金Supported by The National Research Foundation of Korea Grant,Funded by the Korea Government(MEST),No.2010-0001706,South Korea
文摘The adenosine monophosphate-activated protein kinase (AMPK) and p70 ribosomal S6 kinase-1 pathway may serve as a key signaling flow that regulates energy metabolism; thus, this pathway becomes an attractive target for the treatment of liver diseases that result from metabolic derangements. In addition, AMPK emerges as a kinase that controls the redox-state and mitochondrial function, whose activity may be modulated by antioxidants. A close link exists between fuel metabolism and mitochondrial biogenesis. The relationship between fuel metabolism and cell survival strongly implies the existence of a shared signaling network, by which hepatocytes respond to challenges of external stimuli. The AMPK pathway may belong to this network. A series of drugs and therapeutic candidates enable hepatocytes to protect mitochondria from radical stress and increase cell viability, which may be associated with the activation of AMPK, liver kinase B1, and other molecules or components. Consequently, the components downstream of AMPK may contribute to stabilizing mitochondrial membrane potential for hepatocyte survival. In this review, we discuss the role of the AMPK pathway in hepatic energy metabolism and hepatocyte viability. This information may help identify ways to prevent and/or treat hepatic diseases caused by the metabolic syndrome. Moreover, clinical drugs and experimental therapeutic candidates that directly or indirectly modulate the AMPK pathway in distinct manners are discussed here with particular emphasis on their effects on fuel metabolism and mitochondrial function.
