Objective:A high-fat,low-carbohydrate ketogenic diet has been used to treat malignant glioma,in which the Raf/MEK/ERK signaling pathway is overactivated.However,whether the Raf/MEK/ERK signaling pathway is involved in...Objective:A high-fat,low-carbohydrate ketogenic diet has been used to treat malignant glioma,in which the Raf/MEK/ERK signaling pathway is overactivated.However,whether the Raf/MEK/ERK signaling pathway is involved in the therapeutic effect of ketone bodies remains unknown.In this study,we investigated the effects of a major ketone body,3-hydroxybutyric acid(3-HBA),on the proliferation and metastasis of malignant glioblastoma cells and the underlying mechanism.Methods:Two human malignant glioblastoma cell lines(U87 and U251)were treated with different concentrations of 3-HBA with or without the Raf inhibitor PAF C-16 for 24 h.Cell proliferation,cell cycle,cell invasion,and phospholipase D1(PLD1)activity were determined.Protein and gene expression levels of Raf/MEK/ERK signaling pathway members were examined.Results:3-HBA significantly decreased cell proliferation,invasion,and intracellular PLD1 activity in both U87 and U251 glioblastoma cell lines.3-HBA treatment significantly increased the proportion of cells in the G1 phase and decreased the proportion of cells in S phase in U87 cells.In the U251 line,the proportion of treated cells in S phase was increased and proportion of cells in G2 was decreased.3-HBA treatment also significantly decreased the protein expression levels of Raf,MEK,p-MEK,ERK,p-ERK,and PLD1 while increasing p53 expression;an effect that was similar to treatment with the Raf inhibitor.Co-treatment of 3-HBA with the Raf inhibitor further enhanced the effects of the 3-HBA in both cell lines.Conclusion:We confirmed that a ketogenic microenvironment can inhibit glioma cell proliferation and invasion by downregulating the expression of PLD1 through the Raf/MEK/ERK signaling pathway.展开更多
BACKGROUND Gastrointestinal stromal tumors(GISTs)are the most common mesenchymal tumors of the gastrointestinal tract.Tyrosine kinase inhibitors,such as imatinib,have been used as first-line therapy for the treatment ...BACKGROUND Gastrointestinal stromal tumors(GISTs)are the most common mesenchymal tumors of the gastrointestinal tract.Tyrosine kinase inhibitors,such as imatinib,have been used as first-line therapy for the treatment of GISTs.Although these drugs have achieved considerable efficacy in some patients,reports of resistance and recurrence have emerged.Extracellular signal-regulated kinase 1/2(ERK1/2)protein,as a member of the mitogen-activated protein kinase(MAPK)family,is a core molecule of this signaling pathway.Nowadays,research reports on the important clinical and prognostic value of phosphorylated-ERK(P-ERK)and phosphorylated-MAPK/ERK kinase(P-MEK)proteins closely related to raf kinase inhibitor protein(RKIP)have gradually emerged in digestive tract tumors such as gastric cancer,colon cancer,and pancreatic cancer.However,literature on the expression of these downstream proteins combined with RKIP in GIST is scarce.This study will focus on this aspect and search for answers to the problem.AIM To detect the expression of RKIP,P-ERK,and P-MEK protein in GIST and to analyze their relationship with clinicopathological characteristics and prognosis of this disease.Try to establish a new prognosis evaluation model using RKIP and PERK in combination with analysis and its prognosis evaluation efficacy.METHODS The research object of our experiment was 66 pathologically diagnosed GIST patients with complete clinical and follow-up information.These patients received surgical treatment at China Medical University Affiliated Hospital from January 2015 to January 2020.Immunohistochemical method was used to detect the expression of RKIP,PERK,and P-MEK proteins in GIST tissue samples from these patients.Kaplan-Meier method was used to calculate the survival rate of 63 patients with complete follow-up data.A Nomogram was used to represent the new prognostic evaluation model.The Cox multivariate regression analysis was conducted separately for each set of risk evaluation factors,based on two risk classification systems[the new risk grade model vs the modified National Institutes of Health(NIH)2008 risk classification system].Receiver operating characteristic(ROC)curves were used for evaluating the accuracy and efficiency of the two prognostic evaluation systems.RESULTS In GIST tissues,RKIP protein showed positive expression in the cytoplasm and cell membrane,appearing as brownish-yellow or brown granules.The expression of RKIP was related to GIST tumor size,NIH grade,and mucosal invasion.P-ERK protein exhibited heterogeneous distribution in GIST cells,mainly in the cytoplasm,with occasional presence in the nucleus,and appeared as brownish-yellow granules,and the expression of P-ERK protein was associated with GIST tumor size,mitotic count,mucosal invasion,and NIH grade.Meanwhile,RKIP protein expression was negatively correlated with P-ERK expression.The results in COX multivariate regression analysis showed that RKIP protein expression was not an independent risk factor for tumor prognosis.However,RKIP combined with P-ERK protein expression were identified as independent risk factors for prognosis with statistical significance.Furthermore,we establish a new prognosis evaluation model using RKIP and P-ERK in combination and obtained the nomogram of the new prognosis evaluation model.ROC curve analysis also showed that the new evaluation model had better prognostic performance than the modified NIH 2008 risk classification system.CONCLUSION Our experimental results showed that the expression of RKIP and P-ERK proteins in GIST was associated with tumor size,NIH 2008 staging,and tumor invasion,and P-ERK expression was also related to mitotic count.The expression of the two proteins had a certain negative correlation.The combined expression of RKIP and P-ERK proteins can serve as an independent risk factor for predicting the prognosis of GIST patients.The new risk assessment model incorporating RKIP and P-ERK has superior evaluation efficacy and is worth further practical application to validate.展开更多
基金supported by the Clinical Innovation Guidance Plan of the Department of Science and Technology of Hunan Province(No.2018SK51502)a Postgraduate Scientific Research Innovation Project of Hunan Province(No.CX20210977)+1 种基金Key Guiding Subjects of the Hunan Provincial Health Commission(No.20201912)the Natural Science Foundation of Hunan Province(Nos.2020JJ8029,2018JJ3461).
文摘Objective:A high-fat,low-carbohydrate ketogenic diet has been used to treat malignant glioma,in which the Raf/MEK/ERK signaling pathway is overactivated.However,whether the Raf/MEK/ERK signaling pathway is involved in the therapeutic effect of ketone bodies remains unknown.In this study,we investigated the effects of a major ketone body,3-hydroxybutyric acid(3-HBA),on the proliferation and metastasis of malignant glioblastoma cells and the underlying mechanism.Methods:Two human malignant glioblastoma cell lines(U87 and U251)were treated with different concentrations of 3-HBA with or without the Raf inhibitor PAF C-16 for 24 h.Cell proliferation,cell cycle,cell invasion,and phospholipase D1(PLD1)activity were determined.Protein and gene expression levels of Raf/MEK/ERK signaling pathway members were examined.Results:3-HBA significantly decreased cell proliferation,invasion,and intracellular PLD1 activity in both U87 and U251 glioblastoma cell lines.3-HBA treatment significantly increased the proportion of cells in the G1 phase and decreased the proportion of cells in S phase in U87 cells.In the U251 line,the proportion of treated cells in S phase was increased and proportion of cells in G2 was decreased.3-HBA treatment also significantly decreased the protein expression levels of Raf,MEK,p-MEK,ERK,p-ERK,and PLD1 while increasing p53 expression;an effect that was similar to treatment with the Raf inhibitor.Co-treatment of 3-HBA with the Raf inhibitor further enhanced the effects of the 3-HBA in both cell lines.Conclusion:We confirmed that a ketogenic microenvironment can inhibit glioma cell proliferation and invasion by downregulating the expression of PLD1 through the Raf/MEK/ERK signaling pathway.
基金Natural Science Foundation of Liaoning Province,No.2020-MS-148。
文摘BACKGROUND Gastrointestinal stromal tumors(GISTs)are the most common mesenchymal tumors of the gastrointestinal tract.Tyrosine kinase inhibitors,such as imatinib,have been used as first-line therapy for the treatment of GISTs.Although these drugs have achieved considerable efficacy in some patients,reports of resistance and recurrence have emerged.Extracellular signal-regulated kinase 1/2(ERK1/2)protein,as a member of the mitogen-activated protein kinase(MAPK)family,is a core molecule of this signaling pathway.Nowadays,research reports on the important clinical and prognostic value of phosphorylated-ERK(P-ERK)and phosphorylated-MAPK/ERK kinase(P-MEK)proteins closely related to raf kinase inhibitor protein(RKIP)have gradually emerged in digestive tract tumors such as gastric cancer,colon cancer,and pancreatic cancer.However,literature on the expression of these downstream proteins combined with RKIP in GIST is scarce.This study will focus on this aspect and search for answers to the problem.AIM To detect the expression of RKIP,P-ERK,and P-MEK protein in GIST and to analyze their relationship with clinicopathological characteristics and prognosis of this disease.Try to establish a new prognosis evaluation model using RKIP and PERK in combination with analysis and its prognosis evaluation efficacy.METHODS The research object of our experiment was 66 pathologically diagnosed GIST patients with complete clinical and follow-up information.These patients received surgical treatment at China Medical University Affiliated Hospital from January 2015 to January 2020.Immunohistochemical method was used to detect the expression of RKIP,PERK,and P-MEK proteins in GIST tissue samples from these patients.Kaplan-Meier method was used to calculate the survival rate of 63 patients with complete follow-up data.A Nomogram was used to represent the new prognostic evaluation model.The Cox multivariate regression analysis was conducted separately for each set of risk evaluation factors,based on two risk classification systems[the new risk grade model vs the modified National Institutes of Health(NIH)2008 risk classification system].Receiver operating characteristic(ROC)curves were used for evaluating the accuracy and efficiency of the two prognostic evaluation systems.RESULTS In GIST tissues,RKIP protein showed positive expression in the cytoplasm and cell membrane,appearing as brownish-yellow or brown granules.The expression of RKIP was related to GIST tumor size,NIH grade,and mucosal invasion.P-ERK protein exhibited heterogeneous distribution in GIST cells,mainly in the cytoplasm,with occasional presence in the nucleus,and appeared as brownish-yellow granules,and the expression of P-ERK protein was associated with GIST tumor size,mitotic count,mucosal invasion,and NIH grade.Meanwhile,RKIP protein expression was negatively correlated with P-ERK expression.The results in COX multivariate regression analysis showed that RKIP protein expression was not an independent risk factor for tumor prognosis.However,RKIP combined with P-ERK protein expression were identified as independent risk factors for prognosis with statistical significance.Furthermore,we establish a new prognosis evaluation model using RKIP and P-ERK in combination and obtained the nomogram of the new prognosis evaluation model.ROC curve analysis also showed that the new evaluation model had better prognostic performance than the modified NIH 2008 risk classification system.CONCLUSION Our experimental results showed that the expression of RKIP and P-ERK proteins in GIST was associated with tumor size,NIH 2008 staging,and tumor invasion,and P-ERK expression was also related to mitotic count.The expression of the two proteins had a certain negative correlation.The combined expression of RKIP and P-ERK proteins can serve as an independent risk factor for predicting the prognosis of GIST patients.The new risk assessment model incorporating RKIP and P-ERK has superior evaluation efficacy and is worth further practical application to validate.
