Glioblastoma multiforme （GBM） is the most aggressive primary brain tumor in adults.Current therapy includes surgery,radiation and chemotherapy with temozolomide （TMZ）.Major determinants of clinical response to TMZ...Glioblastoma multiforme （GBM） is the most aggressive primary brain tumor in adults.Current therapy includes surgery,radiation and chemotherapy with temozolomide （TMZ）.Major determinants of clinical response to TMZ include methylation status of the O6-methylguanine-DNA methyltransferase （MGMT） promoter and mismatch repair （MMR） status.Though the MGMT promoter is methylated in 45% of cases,for the first nine months of follow-up,TMZ does not change survival outcome.Furthermore,MMR deficiency makes little contribution to clinical resistance,suggesting that there exist unrecognized mechanisms of resistance.We generated paired GBM cell lines whose resistance was attributed to neither MGMT nor MMR.We show that,responding to TMZ,these cells exhibit a decoupling of DNA damage response （DDR） from ongoing DNA damages.They display methylation-resistant synthesis in which ongoing DNA synthesis is not inhibited.They are also defective in the activation of the S and G2 phase checkpoint.DDR proteins ATM,Chk2,MDC1,NBS1 and gammaH2AX also fail to form discrete foci.These results demonstrate that failure of DDR may play an active role in chemoresistance to TMZ.DNA damages by TMZ are repaired by MMR proteins in a futile,reiterative process,which activates DDR signaling network that ultimately leads to the onset of cell death.GBM cells may survive genetic insults in the absence of DDR.We anticipate that our findings will lead to more studies that seek to further define the role of DDR in ultimately determining the fate of a tumor cell in response to TMZ and other DNA methylators.展开更多
Objective： To summary the recent advances in molecular research of glioblastoma （GBM） and current trends in personalized therapy of this disease.Data Sources： Data cited in this review were obtained mainly from Pu...Objective： To summary the recent advances in molecular research of glioblastoma （GBM） and current trends in personalized therapy of this disease.Data Sources： Data cited in this review were obtained mainly from PubMed in English up to 2015, with keywords ＆quot;molecular＆quot;, ＆quot;genetics＆quot;, ＆quot;GBM＆quot;, ＆quot;isocitrate dehydrogenase＆quot;, ＆quot;telomerase reverse transcriptase＆quot;, ＆quot;epidermal growth factor receptor＆quot;, ＆quot;PTPRZ1-MET＆quot;, and ＆quot;clinical treatment＆quot;.Study Selection： Articles regarding the morphological pathology of GBM, the epidemiology of GBM, genetic alteration of GBM, and the development of treatment for GBM patients were identified, retrieved, and reviewed.Results： There is a large amount of data supporting the view that these recurrent genetic aberrations occur in a specific context of cellular origin, co-oncogenic hits and are present in distinct patient populations.Primary and secondary GBMs are distinct disease entities that affect different age groups of patients and develop through distinct genetic aberrations.These differences are important, especially because they may affect sensitivity to radio-and chemo-therapy and should thus be considered in the identification of targets for novel therapeutic approaches.Conclusion： This review highlights the molecular and genetic alterations of GBM, indicating that they are of potential value in the diagnosis and treatment for patients with GBM.展开更多
Epidermal growth factor receptor (EGFR) has been shown to play an important role in the malignant progression of diffuse astrocytomas. Numerous studies have investigated the clinical significance of overexpression and...Epidermal growth factor receptor (EGFR) has been shown to play an important role in the malignant progression of diffuse astrocytomas. Numerous studies have investigated the clinical significance of overexpression and amplification of the EGFR gene in these tumours with ambiguous results. The aim of this study was therefore to review the literature to get the current prognostic and diagnostic status. The PubMed database was used to search for papers in English in the time period 1987-2010 using the following keywords: astrocytoma, glioma, c-erbB1, EGFR, glioblastoma, HER1 and prognosis. Other inclusion criteria were: 1) studies with more than 50 patients;2) patient age over 18 years;3) tumour grading according to the latest World Health Organization (WHO) classification (2007) and 4) EGFR overexpression assessed by immunohistochemistry. A total of 47 publications were included and several reported positive correlations between both EGFR gene amplification and overexpression with histological malignancy grade and survival. The results are, however, encumbered with elements of uncertainty involving for instance methodological diversities and small number of patients. Larger studies with standardized procedures are necessary to fully clarify the clinical role of EGFR in human astrocytomas.展开更多
OBJECTIVE Glioblastomas(GBM) are the most malignant brain tumors in humans and have a very poor prognosis.New therapeutics are urgently needed.Here,we reported 2-methoxy-6-acetyl-7-methyljuglone(MAM)-induced cell deat...OBJECTIVE Glioblastomas(GBM) are the most malignant brain tumors in humans and have a very poor prognosis.New therapeutics are urgently needed.Here,we reported 2-methoxy-6-acetyl-7-methyljuglone(MAM)-induced cell death in U87 and U251 glioma cancer cells.METHODS Cells were cultured and treated with MAM,the cell viability was determined by MTT assay and LDH assay.Intracellular reactive oxygen species(ROS) generation was observed by DCF fluorescence.The protein expression was determined by Western blotting.RESULTS MAM induced glioma cancer cell death without caspase activation.The cell death induced by MAM was attenuated by the pharmacological or genetic blockage of necroptosis signaling,including RIP1 inhibitor necrostatin-1 s(Nec-1 s) and siRNA-mediated gene silencing of RIP1 and RIP3,but was unaffected by caspase inhibitor z-vad-fmk or necrosis inhibitor 2-(1 H-Indol-3-yl)-3-pentylamino-maleimide(IM54).MAM treated U87 and U251 glioma cancer cells induced RIP1/RIP3 complex formation,ROS level increased,ATP concentration decreased and loss of plasma membrane integrity,further confirmed this process was necroptosis.The essential role of ROS was confirmed by the protective effect of ROS scavenger NAC.Interestingly,MAM induced necroptosis both triggered by RIP1/RIP3 complex and ROS generation.Moreover,MAM induced necroptosis through cytosolic calcium(Ca2 +) accumulation and sustained c-Jun N-terminal kinase(JNK) activation.Both calcium chelator BAPTA-AM and JNK inhibitor SP600125 could attenuate cell death.Further,we found there exists a feedback loop between RIP1 and JNK activation.Finally,MAM induced necroptosis was inhibited by dicoumarol(a NQO1 inhibitor).Dicoumarol exposed glioma cancer cells were resistant to RIP1/RIP3 complex formation and ROS generation.MAM induced necroptosis was independent of MLKL.CONCLUSION MAM induced non-canonical necroptosis through the NQO1-dependent ROS and RIP1/RIP3 pathway.This study also provided new insights into the molecular regulation of necroptosis in human glioma cancer cell展开更多
Elevated levels of γ-synuclein(γ-syn)expression have been noted in the progression of glioblastomas,and also in the cerebrospinal fluid of patients diagnosed with neurodegenerative diseases.γ-Syn can be either inte...Elevated levels of γ-synuclein(γ-syn)expression have been noted in the progression of glioblastomas,and also in the cerebrospinal fluid of patients diagnosed with neurodegenerative diseases.γ-Syn can be either internalized from the extracellular milieu or expressed endogenously by human cortical astrocytes.Internalizedγ-syn results in increased cellular proliferation,brain derived neurotrophic factor release and astroprotection.However,the function of endogenousγ-syn in primary astrocytes,and the relationship to these two opposing disease states are unknown.γ-Syn is expressed by astrocytes in the human cortex,and to gain a better understanding of the role of endogenous γ-syn,primary human cortical astrocytes were treated with chimera RNA interference(RNAi)targeting γ-syn after release from cell synchronization.Quantitative polymerase chain reaction analysis demonstrated an increase in endogenousγ-syn expression 48 hours after release from cell synchronization,while RNAi reduced γ-syn expression to control levels.Immunocytochemistry of Ki67 and 5-bromodeoxyuridine showed chimera RNAi γ-syn knockdown reduced cellular proliferation at 24 and 48 hours after release from cell synchronization.To further investigate the consequence of γ-syn knockdown on the astrocytic cell cycle,phosphorylated histone H3 pSer10(pHH3)and phosphorylated cyclin dependent kinase-2 pTyr15(pCDK2)levels were observed via western blot analysis.The results revealed an elevated expression of pHH3,but not pCDK2,indicating γ-syn knockdown leads to disruption of the cell cycle and chromosomal compaction after 48 hours.Subsequently,flow cytometry with propidium iodide determined that increases in apoptosis coincided with γ-syn knockdown.Therefore,γ-syn exerts its effect to allow normal astrocytic progression through the cell cycle,as evidenced by decreased proliferation marker expression,increased pHH3,and mitotic catastrophe after knockdown.In this study,we demonstrated that the knockdown of γ-syn within primary human cortical astroc展开更多
Microvesicles (MVs) or shedding membrane vesicles have recently been described as a novel model of intercellular communication. Previously, MVs were considered as unnecessary or secreted cellular debris, but MVs have ...Microvesicles (MVs) or shedding membrane vesicles have recently been described as a novel model of intercellular communication. Previously, MVs were considered as unnecessary or secreted cellular debris, but MVs have lately been described as having roles in a variety of biological functions, such as cell homeostasis and the cellular processes involved in the oncogenesis of many types of tumors. Carrying several key molecules that contribute to tumor development and progression, similar to mRNAs, microRNAs and other non-coding RNAs, DNA and even small proteins, MVs can be considered as a ubiquitous form of novel cell communication that is present in most somatic cells. Although tumor-derived MVs have been demonstrated in different types of cancers, the literature data on MVs in primary central nervous system (CNS) tumors are relatively scarce. In this review, we address the involvement of MVs in diffuse astrocytomas, particularly glioblastomas, as well as oligodendrogliomas and medulloblastomas. We placed particular focus on the cellular crosstalk between tumor and “normal” cells, the putative mechanisms how the tumor microenvironment is modulated and the spread of aggressive phenotypes. Additionally, a better understanding of the participation of tumor-derived MVs in the regulation of key cancer pathways will offer new insights into tumor pathogenesis and the mechanisms of multidrug resistance, and may help to develop new strategies for novel therapies against these infiltrative CNS tumors.展开更多
目的探讨surv iv in在胶质母细胞瘤中的表达及与其凋亡、增殖和微血管密度(M VD)的相关性。方法应用免疫组织化学(SP)法检测42例份胶质母细胞瘤石蜡切片中surv iv in、K i-67和第8因子相关抗原(FⅧRA g)的表达情况,并用末端转移标记法...目的探讨surv iv in在胶质母细胞瘤中的表达及与其凋亡、增殖和微血管密度(M VD)的相关性。方法应用免疫组织化学(SP)法检测42例份胶质母细胞瘤石蜡切片中surv iv in、K i-67和第8因子相关抗原(FⅧRA g)的表达情况,并用末端转移标记法测定凋亡指数(A I)。结果surv iv in在胶质母细胞瘤中的表达阳性率为81.0%,而正常对照组中无1例阳性表达;surv iv in的表达与K i67及M VD呈正相关,而与A I负相关。结论surv iv in在胶质母细胞瘤的发生和发展中可能通过调控细胞的凋亡和增殖起着重要作用,并参与肿瘤血管的生成。可望成为诊断治疗的新靶点。展开更多
基金supported by NIH grants 5-P50-NS20023 and NS030245 (Darell D. Bigner)a grant from the Pediatric Brain Tumor Foundation (Henry S. Friedman)
文摘Glioblastoma multiforme （GBM） is the most aggressive primary brain tumor in adults.Current therapy includes surgery,radiation and chemotherapy with temozolomide （TMZ）.Major determinants of clinical response to TMZ include methylation status of the O6-methylguanine-DNA methyltransferase （MGMT） promoter and mismatch repair （MMR） status.Though the MGMT promoter is methylated in 45% of cases,for the first nine months of follow-up,TMZ does not change survival outcome.Furthermore,MMR deficiency makes little contribution to clinical resistance,suggesting that there exist unrecognized mechanisms of resistance.We generated paired GBM cell lines whose resistance was attributed to neither MGMT nor MMR.We show that,responding to TMZ,these cells exhibit a decoupling of DNA damage response （DDR） from ongoing DNA damages.They display methylation-resistant synthesis in which ongoing DNA synthesis is not inhibited.They are also defective in the activation of the S and G2 phase checkpoint.DDR proteins ATM,Chk2,MDC1,NBS1 and gammaH2AX also fail to form discrete foci.These results demonstrate that failure of DDR may play an active role in chemoresistance to TMZ.DNA damages by TMZ are repaired by MMR proteins in a futile,reiterative process,which activates DDR signaling network that ultimately leads to the onset of cell death.GBM cells may survive genetic insults in the absence of DDR.We anticipate that our findings will lead to more studies that seek to further define the role of DDR in ultimately determining the fate of a tumor cell in response to TMZ and other DNA methylators.
文摘Objective： To summary the recent advances in molecular research of glioblastoma （GBM） and current trends in personalized therapy of this disease.Data Sources： Data cited in this review were obtained mainly from PubMed in English up to 2015, with keywords ＆quot;molecular＆quot;, ＆quot;genetics＆quot;, ＆quot;GBM＆quot;, ＆quot;isocitrate dehydrogenase＆quot;, ＆quot;telomerase reverse transcriptase＆quot;, ＆quot;epidermal growth factor receptor＆quot;, ＆quot;PTPRZ1-MET＆quot;, and ＆quot;clinical treatment＆quot;.Study Selection： Articles regarding the morphological pathology of GBM, the epidemiology of GBM, genetic alteration of GBM, and the development of treatment for GBM patients were identified, retrieved, and reviewed.Results： There is a large amount of data supporting the view that these recurrent genetic aberrations occur in a specific context of cellular origin, co-oncogenic hits and are present in distinct patient populations.Primary and secondary GBMs are distinct disease entities that affect different age groups of patients and develop through distinct genetic aberrations.These differences are important, especially because they may affect sensitivity to radio-and chemo-therapy and should thus be considered in the identification of targets for novel therapeutic approaches.Conclusion： This review highlights the molecular and genetic alterations of GBM, indicating that they are of potential value in the diagnosis and treatment for patients with GBM.
文摘Epidermal growth factor receptor (EGFR) has been shown to play an important role in the malignant progression of diffuse astrocytomas. Numerous studies have investigated the clinical significance of overexpression and amplification of the EGFR gene in these tumours with ambiguous results. The aim of this study was therefore to review the literature to get the current prognostic and diagnostic status. The PubMed database was used to search for papers in English in the time period 1987-2010 using the following keywords: astrocytoma, glioma, c-erbB1, EGFR, glioblastoma, HER1 and prognosis. Other inclusion criteria were: 1) studies with more than 50 patients;2) patient age over 18 years;3) tumour grading according to the latest World Health Organization (WHO) classification (2007) and 4) EGFR overexpression assessed by immunohistochemistry. A total of 47 publications were included and several reported positive correlations between both EGFR gene amplification and overexpression with histological malignancy grade and survival. The results are, however, encumbered with elements of uncertainty involving for instance methodological diversities and small number of patients. Larger studies with standardized procedures are necessary to fully clarify the clinical role of EGFR in human astrocytomas.
基金supported by Science and Technology Development Fund of Macao Special Administrative Region (078/2016/A2) and Research Fund of University of Macao (MYRG2016-00043-1CMS-QRCM)
文摘OBJECTIVE Glioblastomas(GBM) are the most malignant brain tumors in humans and have a very poor prognosis.New therapeutics are urgently needed.Here,we reported 2-methoxy-6-acetyl-7-methyljuglone(MAM)-induced cell death in U87 and U251 glioma cancer cells.METHODS Cells were cultured and treated with MAM,the cell viability was determined by MTT assay and LDH assay.Intracellular reactive oxygen species(ROS) generation was observed by DCF fluorescence.The protein expression was determined by Western blotting.RESULTS MAM induced glioma cancer cell death without caspase activation.The cell death induced by MAM was attenuated by the pharmacological or genetic blockage of necroptosis signaling,including RIP1 inhibitor necrostatin-1 s(Nec-1 s) and siRNA-mediated gene silencing of RIP1 and RIP3,but was unaffected by caspase inhibitor z-vad-fmk or necrosis inhibitor 2-(1 H-Indol-3-yl)-3-pentylamino-maleimide(IM54).MAM treated U87 and U251 glioma cancer cells induced RIP1/RIP3 complex formation,ROS level increased,ATP concentration decreased and loss of plasma membrane integrity,further confirmed this process was necroptosis.The essential role of ROS was confirmed by the protective effect of ROS scavenger NAC.Interestingly,MAM induced necroptosis both triggered by RIP1/RIP3 complex and ROS generation.Moreover,MAM induced necroptosis through cytosolic calcium(Ca2 +) accumulation and sustained c-Jun N-terminal kinase(JNK) activation.Both calcium chelator BAPTA-AM and JNK inhibitor SP600125 could attenuate cell death.Further,we found there exists a feedback loop between RIP1 and JNK activation.Finally,MAM induced necroptosis was inhibited by dicoumarol(a NQO1 inhibitor).Dicoumarol exposed glioma cancer cells were resistant to RIP1/RIP3 complex formation and ROS generation.MAM induced necroptosis was independent of MLKL.CONCLUSION MAM induced non-canonical necroptosis through the NQO1-dependent ROS and RIP1/RIP3 pathway.This study also provided new insights into the molecular regulation of necroptosis in human glioma cancer cell
基金supported by grants from the Connecticut Partnership in Innovation and Education(PIE)Fellowship(to TL)the University of Hartford College of Arts and Sciences Dean’s Fund(to TL,FA,AOK)
文摘Elevated levels of γ-synuclein(γ-syn)expression have been noted in the progression of glioblastomas,and also in the cerebrospinal fluid of patients diagnosed with neurodegenerative diseases.γ-Syn can be either internalized from the extracellular milieu or expressed endogenously by human cortical astrocytes.Internalizedγ-syn results in increased cellular proliferation,brain derived neurotrophic factor release and astroprotection.However,the function of endogenousγ-syn in primary astrocytes,and the relationship to these two opposing disease states are unknown.γ-Syn is expressed by astrocytes in the human cortex,and to gain a better understanding of the role of endogenous γ-syn,primary human cortical astrocytes were treated with chimera RNA interference(RNAi)targeting γ-syn after release from cell synchronization.Quantitative polymerase chain reaction analysis demonstrated an increase in endogenousγ-syn expression 48 hours after release from cell synchronization,while RNAi reduced γ-syn expression to control levels.Immunocytochemistry of Ki67 and 5-bromodeoxyuridine showed chimera RNAi γ-syn knockdown reduced cellular proliferation at 24 and 48 hours after release from cell synchronization.To further investigate the consequence of γ-syn knockdown on the astrocytic cell cycle,phosphorylated histone H3 pSer10(pHH3)and phosphorylated cyclin dependent kinase-2 pTyr15(pCDK2)levels were observed via western blot analysis.The results revealed an elevated expression of pHH3,but not pCDK2,indicating γ-syn knockdown leads to disruption of the cell cycle and chromosomal compaction after 48 hours.Subsequently,flow cytometry with propidium iodide determined that increases in apoptosis coincided with γ-syn knockdown.Therefore,γ-syn exerts its effect to allow normal astrocytic progression through the cell cycle,as evidenced by decreased proliferation marker expression,increased pHH3,and mitotic catastrophe after knockdown.In this study,we demonstrated that the knockdown of γ-syn within primary human cortical astroc
文摘Microvesicles (MVs) or shedding membrane vesicles have recently been described as a novel model of intercellular communication. Previously, MVs were considered as unnecessary or secreted cellular debris, but MVs have lately been described as having roles in a variety of biological functions, such as cell homeostasis and the cellular processes involved in the oncogenesis of many types of tumors. Carrying several key molecules that contribute to tumor development and progression, similar to mRNAs, microRNAs and other non-coding RNAs, DNA and even small proteins, MVs can be considered as a ubiquitous form of novel cell communication that is present in most somatic cells. Although tumor-derived MVs have been demonstrated in different types of cancers, the literature data on MVs in primary central nervous system (CNS) tumors are relatively scarce. In this review, we address the involvement of MVs in diffuse astrocytomas, particularly glioblastomas, as well as oligodendrogliomas and medulloblastomas. We placed particular focus on the cellular crosstalk between tumor and “normal” cells, the putative mechanisms how the tumor microenvironment is modulated and the spread of aggressive phenotypes. Additionally, a better understanding of the participation of tumor-derived MVs in the regulation of key cancer pathways will offer new insights into tumor pathogenesis and the mechanisms of multidrug resistance, and may help to develop new strategies for novel therapies against these infiltrative CNS tumors.
文摘目的探讨surv iv in在胶质母细胞瘤中的表达及与其凋亡、增殖和微血管密度(M VD)的相关性。方法应用免疫组织化学(SP)法检测42例份胶质母细胞瘤石蜡切片中surv iv in、K i-67和第8因子相关抗原(FⅧRA g)的表达情况,并用末端转移标记法测定凋亡指数(A I)。结果surv iv in在胶质母细胞瘤中的表达阳性率为81.0%,而正常对照组中无1例阳性表达;surv iv in的表达与K i67及M VD呈正相关,而与A I负相关。结论surv iv in在胶质母细胞瘤的发生和发展中可能通过调控细胞的凋亡和增殖起着重要作用,并参与肿瘤血管的生成。可望成为诊断治疗的新靶点。
