Background:Gastric cancer(GC)is one of the most common malignancies,and intestinal-type GC is the main histopathologic type of GC in China.We previously reported that casein kinase 2 interacting protein 1(CKIP-1)acts ...Background:Gastric cancer(GC)is one of the most common malignancies,and intestinal-type GC is the main histopathologic type of GC in China.We previously reported that casein kinase 2 interacting protein 1(CKIP-1)acts as a candidate tumor suppressor in intestinal-type GC.CKIP-1 participates in the regulation of multiple signaling pathways,including the Wnt/b-catenin pathway,of which caudal-related homeobox 1(CDX1)may be a downstream target gene.The purpose of this study was to investigate the relationship between CKIP-1 and CDX1 in intestinal-type GC.Methods:Sixty-seven gastroscopy biopsy specimens and surgically resected gastric specimens were divided into four groups:gastric mucosa group,intestinal metaplasia(IM)group,dysplasia group,and intestinal-type GC group.The expression levels of CKIP-1 and CDX1 were detected in these groups and GC cell lines,and the correlations between these expression levels were analyzed.SGC7901 and BGC823 cells were divided into CKIP-1 shRNA groups and CKIP-1 over-expression groups,and CDX1 expression was detected.b-Catenin expression was detected in intestinal-type GC tissue samples and CKIP-1 shRNA and CKIP-1 overexpression SGC7901 cells,and its correlation with CKIP-1 expression in intestinal-type GC tissue was analyzed.The Wnt/b-catenin pathway inhibitor DKK-1 and activator LiCl were incubated with SGC7901 cells,BGC823 cells,and CKIP-1 shRNA and CKIP-1 over-expression SGC7901 and BGC823 cells,following which CDX1 and Ki-67 expression were detected.Results:The expression levels of CKIP-1 and CDX1 were lower in patients with intestinal-type GC than in patients with IM and dysplasia(both P<0.05).CKIP-1 and CDX1 expression levels were positively correlated in IM,dysplasia,and intestinal-type GC tissue and cell lines(r=0.771,P<0.01;r=0.597,P<0.01;r=0.654,P<0.01;r=0.811,P<0.01,respectively).CDX1 expression was decreased in the CKIP-1 shRNA groups and increased in the CKIP-1 over-expression groups of SGC7901 and BGC823 cells compared to that in the corresponding control groups(both P<0.05).CKIP-1 expression was negatively correlated with b-catenin expression in intestinal-typeGCpatients(r=0.458,P<0.01).Compared to the control group,b-catenin expression was increased in the CKIP-1 shRNA SGC7901 cell group and decreased in the CKIP-1 over-expression SGC7901 cell group(P<0.05).CDX1 expression was increased inSGC7901 andBGC823 cells treatedwithDKK-1,DKK-1 increasedCDX1 expression and decreased Ki-67 expression in the CKIP-1 shRNA group;the opposite result was observed in SGC7901 and BGC823 cells treated with LiCl,and LiCl decreased CDX1 expression and increased Ki-67 expression in the CKIP-1 over-expression group(both P<0.05).Conclusions:Through the Wnt/b-catenin signaling pathway,CKIP-1 may positively regulate CDX1 in intestinal-type GC.展开更多
The Ikaros gene encodes a zinc finger,DNA-binding protein that regulates gene transcription and chromatin remodeling.Ikaros is a master regulator of hematopoiesis and an established tumor suppressor.Moderate alteratio...The Ikaros gene encodes a zinc finger,DNA-binding protein that regulates gene transcription and chromatin remodeling.Ikaros is a master regulator of hematopoiesis and an established tumor suppressor.Moderate alteration of Ikaros activity (e.g.haploinsufficiency) appears to be sufficient to promote malignant transformation in human hematopoietic cells.This raises questions about the mechanisms that normally regulate Ikaros function and the potential of these mechanisms to contribute to the development of leukemia.The focus of this review is the regulation of Ikaros function by phosphorylation/dephosphorylation.Site-specific phosphorylation of Ikaros by casein kinase 2 (CK2) controls Ikaros DNA-binding ability and subcellular localization.As a consequence,the ability of Ikaros to regulate cell cycle progression,chromatin remodeling,target gene expression,and thymocyte differentiation are controlled by CK2.In addition,hyperphosphorylation of Ikaros by CK2 leads to decreased Ikaros levels due to ubiquitinmediated degradation.Dephosphorylation of Ikaros by protein phosphatase 1 (PP1) acts in opposition to CK2 to increase Ikaros stability and restore Ikaros DNA binding ability and pericentromeric localization.Thus,the CK2 and PP1 pathways act in concert to regulate Ikaros activity in hematopoiesis and as a tumor suppressor.This highlights the importance of these signal transduction pathways as potential mediators of leukemogenesis via their role in regulating the activities of Ikaros.展开更多
Ischemic stroke can cause blood-brain barrier(BBB)injury,which worsens brain damage induced by stroke.Abnormal expression of tight junction proteins in endothelial cells(ECs)can increase intracellular space and BBB le...Ischemic stroke can cause blood-brain barrier(BBB)injury,which worsens brain damage induced by stroke.Abnormal expression of tight junction proteins in endothelial cells(ECs)can increase intracellular space and BBB leakage.Selective inhibition of mitogen-activated protein kinase,the negative regulatory substrate of mitogen-activated protein kinase phosphatase(MKP)-1,improves tight junction protein function in ECs,and genetic deletion of MKP-1 aggravates ischemic brain injury.However,whether the latter affects BBB integrity,and the cell type-specific mechanism underlying this process,remain unclear.In this study,we established an adult male mouse model of ischemic stroke by occluding the middle cerebral artery for 60 minutes and overexpressed MKP-1 in ECs on the injured side via lentiviral transfection before stroke.We found that overexpression of MKP-1 in ECs reduced infarct volume,reduced the level of inflammatory factors interleukin-1β,interleukin-6,and chemokine C-C motif ligand-2,inhibited vascular injury,and promoted the recovery of sensorimotor and memory/cognitive function.Overexpression of MKP-1 in ECs also inhibited the activation of cerebral ischemia-induced extracellular signal-regulated kinase(ERK)1/2 and the downregulation of occludin expression.Finally,to investigate the mechanism by which MKP-1 exerted these functions in ECs,we established an ischemic stroke model in vitro by depriving the primary endothelial cell of oxygen and glucose,and pharmacologically inhibited the activity of MKP-1 and ERK1/2.Our findings suggest that MKP-1 inhibition aggravates oxygen and glucose deprivation-induced cell death,cell monolayer leakage,and downregulation of occludin expression,and that inhibiting ERK1/2 can reverse these effects.In addition,co-inhibition of MKP-1 and ERK1/2 exhibited similar effects to inhibition of ERK1/2.These findings suggest that overexpression of MKP-1 in ECs can prevent ischemia-induced occludin downregulation and cell death via deactivating ERK1/2,thereby protecting the integrity of BBB,alleviating brain injury,and improving post-stroke prognosis.展开更多
基金This work was supported by the grants from the National Natural Science Foundation of China(No.81560088)Guizhou Provincial Science and Technology Foundation(No.[2019]1209).
文摘Background:Gastric cancer(GC)is one of the most common malignancies,and intestinal-type GC is the main histopathologic type of GC in China.We previously reported that casein kinase 2 interacting protein 1(CKIP-1)acts as a candidate tumor suppressor in intestinal-type GC.CKIP-1 participates in the regulation of multiple signaling pathways,including the Wnt/b-catenin pathway,of which caudal-related homeobox 1(CDX1)may be a downstream target gene.The purpose of this study was to investigate the relationship between CKIP-1 and CDX1 in intestinal-type GC.Methods:Sixty-seven gastroscopy biopsy specimens and surgically resected gastric specimens were divided into four groups:gastric mucosa group,intestinal metaplasia(IM)group,dysplasia group,and intestinal-type GC group.The expression levels of CKIP-1 and CDX1 were detected in these groups and GC cell lines,and the correlations between these expression levels were analyzed.SGC7901 and BGC823 cells were divided into CKIP-1 shRNA groups and CKIP-1 over-expression groups,and CDX1 expression was detected.b-Catenin expression was detected in intestinal-type GC tissue samples and CKIP-1 shRNA and CKIP-1 overexpression SGC7901 cells,and its correlation with CKIP-1 expression in intestinal-type GC tissue was analyzed.The Wnt/b-catenin pathway inhibitor DKK-1 and activator LiCl were incubated with SGC7901 cells,BGC823 cells,and CKIP-1 shRNA and CKIP-1 over-expression SGC7901 and BGC823 cells,following which CDX1 and Ki-67 expression were detected.Results:The expression levels of CKIP-1 and CDX1 were lower in patients with intestinal-type GC than in patients with IM and dysplasia(both P<0.05).CKIP-1 and CDX1 expression levels were positively correlated in IM,dysplasia,and intestinal-type GC tissue and cell lines(r=0.771,P<0.01;r=0.597,P<0.01;r=0.654,P<0.01;r=0.811,P<0.01,respectively).CDX1 expression was decreased in the CKIP-1 shRNA groups and increased in the CKIP-1 over-expression groups of SGC7901 and BGC823 cells compared to that in the corresponding control groups(both P<0.05).CKIP-1 expression was negatively correlated with b-catenin expression in intestinal-typeGCpatients(r=0.458,P<0.01).Compared to the control group,b-catenin expression was increased in the CKIP-1 shRNA SGC7901 cell group and decreased in the CKIP-1 over-expression SGC7901 cell group(P<0.05).CDX1 expression was increased inSGC7901 andBGC823 cells treatedwithDKK-1,DKK-1 increasedCDX1 expression and decreased Ki-67 expression in the CKIP-1 shRNA group;the opposite result was observed in SGC7901 and BGC823 cells treated with LiCl,and LiCl decreased CDX1 expression and increased Ki-67 expression in the CKIP-1 over-expression group(both P<0.05).Conclusions:Through the Wnt/b-catenin signaling pathway,CKIP-1 may positively regulate CDX1 in intestinal-type GC.
基金Supported by (in part) An NIH R01 HL095120 grant,a St.Baldrick’s Foundation Career Development Award,the Four Diamonds Fund of the Pennsylvania State University College of Medicine,and the John Wawrynovic Leukemia Research Scholar Endowment (SD)
文摘The Ikaros gene encodes a zinc finger,DNA-binding protein that regulates gene transcription and chromatin remodeling.Ikaros is a master regulator of hematopoiesis and an established tumor suppressor.Moderate alteration of Ikaros activity (e.g.haploinsufficiency) appears to be sufficient to promote malignant transformation in human hematopoietic cells.This raises questions about the mechanisms that normally regulate Ikaros function and the potential of these mechanisms to contribute to the development of leukemia.The focus of this review is the regulation of Ikaros function by phosphorylation/dephosphorylation.Site-specific phosphorylation of Ikaros by casein kinase 2 (CK2) controls Ikaros DNA-binding ability and subcellular localization.As a consequence,the ability of Ikaros to regulate cell cycle progression,chromatin remodeling,target gene expression,and thymocyte differentiation are controlled by CK2.In addition,hyperphosphorylation of Ikaros by CK2 leads to decreased Ikaros levels due to ubiquitinmediated degradation.Dephosphorylation of Ikaros by protein phosphatase 1 (PP1) acts in opposition to CK2 to increase Ikaros stability and restore Ikaros DNA binding ability and pericentromeric localization.Thus,the CK2 and PP1 pathways act in concert to regulate Ikaros activity in hematopoiesis and as a tumor suppressor.This highlights the importance of these signal transduction pathways as potential mediators of leukemogenesis via their role in regulating the activities of Ikaros.
基金supported by Research Start-up Funding of Shenzhen Traditional Chinese Medicine Hospital,No.2021-07(to FB)Sanming Project of Medicine in Shenzhen,No.SZZYSM 202111011(to XDQ and FB)+1 种基金Key Discipline Established by Zhejiang Province,Jiaxing City Jointly-Pain Medicine,No.2019-ss-ttyx(to LSX)Jiaxing Key Laboratory of Neurology and Pain Medicine,No.[2014]81(to LSX)。
文摘Ischemic stroke can cause blood-brain barrier(BBB)injury,which worsens brain damage induced by stroke.Abnormal expression of tight junction proteins in endothelial cells(ECs)can increase intracellular space and BBB leakage.Selective inhibition of mitogen-activated protein kinase,the negative regulatory substrate of mitogen-activated protein kinase phosphatase(MKP)-1,improves tight junction protein function in ECs,and genetic deletion of MKP-1 aggravates ischemic brain injury.However,whether the latter affects BBB integrity,and the cell type-specific mechanism underlying this process,remain unclear.In this study,we established an adult male mouse model of ischemic stroke by occluding the middle cerebral artery for 60 minutes and overexpressed MKP-1 in ECs on the injured side via lentiviral transfection before stroke.We found that overexpression of MKP-1 in ECs reduced infarct volume,reduced the level of inflammatory factors interleukin-1β,interleukin-6,and chemokine C-C motif ligand-2,inhibited vascular injury,and promoted the recovery of sensorimotor and memory/cognitive function.Overexpression of MKP-1 in ECs also inhibited the activation of cerebral ischemia-induced extracellular signal-regulated kinase(ERK)1/2 and the downregulation of occludin expression.Finally,to investigate the mechanism by which MKP-1 exerted these functions in ECs,we established an ischemic stroke model in vitro by depriving the primary endothelial cell of oxygen and glucose,and pharmacologically inhibited the activity of MKP-1 and ERK1/2.Our findings suggest that MKP-1 inhibition aggravates oxygen and glucose deprivation-induced cell death,cell monolayer leakage,and downregulation of occludin expression,and that inhibiting ERK1/2 can reverse these effects.In addition,co-inhibition of MKP-1 and ERK1/2 exhibited similar effects to inhibition of ERK1/2.These findings suggest that overexpression of MKP-1 in ECs can prevent ischemia-induced occludin downregulation and cell death via deactivating ERK1/2,thereby protecting the integrity of BBB,alleviating brain injury,and improving post-stroke prognosis.
