Although it is believed that glioma is derived from brain tumor stem cells, the source and molecular signal pathways of these cells are still unclear. In this study, we used stable doxycycline-inducible transgenic mou...Although it is believed that glioma is derived from brain tumor stem cells, the source and molecular signal pathways of these cells are still unclear. In this study, we used stable doxycycline-inducible transgenic mouse brain tumor models （c-myc/SV40Tag＋/Tet-on＋） to explore the malignant trans- formation potential of neural stem cells by observing the differences of neural stem cells and brain tumor stem cells in the tumor models. Results showed that chromosome instability occurred in brain tumor stem cells. The numbers of cytolysosomes and autophagosomes in brain tumor stem cells and induced neural stem cells were lower and the proliferative activity was obviously stronger than that in normal neural stem cells. Normal neural stem cells could differentiate into glial fibrillary acidic protein-positive and microtubule associated protein-2-positive cells, which were also negative for nestin. However, glial fibrillary acidic protein/nestin, microtubule associated protein-2/nestin, and glial fibrillary acidic protein/microtubule associated protein-2 double-positive cells were found in induced neural stem cells and brain tumor stem cells. Results indicate that induced neural stem cells are similar to brain tumor stem cells, and are possibly the source of brain tumor stem cells.展开更多
Objective:To investigate the interference and expression of human glial cell line-derived neurotrophic factor(hCDNF) and soluble TNF alpha(sTMFRⅠ) receptor genes in neural stem cells and to evaluate the roles of thes...Objective:To investigate the interference and expression of human glial cell line-derived neurotrophic factor(hCDNF) and soluble TNF alpha(sTMFRⅠ) receptor genes in neural stem cells and to evaluate the roles of these proteins in the genetic treatment of spinal cord injury.Methods:Full-length of GDNF cDNA(538 bp) and sTMFRⅠcDNA(504 bp) were inserted into the early 1 region of adenovirus genomic DNA respectively and were immediated by the human cytomegalovirus(gene promoter/enhancer). These adenoviruses were propagated in HEK293 cells via homologous recombination for 7-10 days in vivo,then they were used to infect human neural stem ceils.The infection and expression of gene were tested under immunofluorescence.ELISA and Westem-blot after 48 hours.Results:Almost all the cultured cells showed the nestin immunofluorescence positive staining,which was the characteristics of neural stem cell.A great quantity of EGFP and KFP were observed in neural stem cells,which indicated the expression of GDNF and sTMFRⅠ.After transfection of GDNF and sTMFRⅠgenes,many neural stem cells show GFAP and tubulin immunofluorescence positive staining,which meant that most neural stem cells differentiated into neuron at that condition.Conclusions:The infective efficiency of adenovirus is greatly acceptable to neural stem cell,thus adenovirus provide a useful vector for exogenous GDNF and sTMFRⅠgenes expressing in neural stem cells,which is useful for differentiation of neural stem cell.展开更多
Hepatocellular carcinoma(HCC) is the most common primary malignancy of the liver. It is the second leading cause of cancer-related deaths worldwide, with a very poor prognosis. In the United States, there has been onl...Hepatocellular carcinoma(HCC) is the most common primary malignancy of the liver. It is the second leading cause of cancer-related deaths worldwide, with a very poor prognosis. In the United States, there has been only minimal improvement in the prognosis for HCC patients over the past 15 years. Details of the molecular mechanisms and other mechanisms of HCC progression remain unclear. Consequently, there is an urgent need for better understanding of these mechanisms. HCC is often diagnosed at advanced stages, and most patients will therefore need systemic therapy, with sorafenib being the most common at the present time. However, sorafenib therapy only minimally enhances patient survival. This review provides a summary of some of the known mechanisms that either cause HCC or contribute to its progression. Included in this review are the roles of viral hepatitis, non-viral hepatitis, chronic alcohol intake, genetic predisposition and congenital abnormalities, toxic exposures, and autoimmune diseases of the liver. Well-established molecular mechanisms of HCC progression such as epithelial-mesenchymal transition, tumor-stromal interactions and the tumor microenvironment, cancer stem cells, and senescence bypass are also discussed. Additionally, we discuss the roles of circulating tumor cells,immunomodulation, and neural regulation as potential new mechanisms of HCC progression. A better understanding of these mechanisms could have implications for the development of novel and more effective therapeutic and prognostic strategies, which are critically needed.展开更多
文摘Although it is believed that glioma is derived from brain tumor stem cells, the source and molecular signal pathways of these cells are still unclear. In this study, we used stable doxycycline-inducible transgenic mouse brain tumor models （c-myc/SV40Tag＋/Tet-on＋） to explore the malignant trans- formation potential of neural stem cells by observing the differences of neural stem cells and brain tumor stem cells in the tumor models. Results showed that chromosome instability occurred in brain tumor stem cells. The numbers of cytolysosomes and autophagosomes in brain tumor stem cells and induced neural stem cells were lower and the proliferative activity was obviously stronger than that in normal neural stem cells. Normal neural stem cells could differentiate into glial fibrillary acidic protein-positive and microtubule associated protein-2-positive cells, which were also negative for nestin. However, glial fibrillary acidic protein/nestin, microtubule associated protein-2/nestin, and glial fibrillary acidic protein/microtubule associated protein-2 double-positive cells were found in induced neural stem cells and brain tumor stem cells. Results indicate that induced neural stem cells are similar to brain tumor stem cells, and are possibly the source of brain tumor stem cells.
基金Shenzhen Science and Technology Project(No.201103061)
文摘Objective:To investigate the interference and expression of human glial cell line-derived neurotrophic factor(hCDNF) and soluble TNF alpha(sTMFRⅠ) receptor genes in neural stem cells and to evaluate the roles of these proteins in the genetic treatment of spinal cord injury.Methods:Full-length of GDNF cDNA(538 bp) and sTMFRⅠcDNA(504 bp) were inserted into the early 1 region of adenovirus genomic DNA respectively and were immediated by the human cytomegalovirus(gene promoter/enhancer). These adenoviruses were propagated in HEK293 cells via homologous recombination for 7-10 days in vivo,then they were used to infect human neural stem ceils.The infection and expression of gene were tested under immunofluorescence.ELISA and Westem-blot after 48 hours.Results:Almost all the cultured cells showed the nestin immunofluorescence positive staining,which was the characteristics of neural stem cell.A great quantity of EGFP and KFP were observed in neural stem cells,which indicated the expression of GDNF and sTMFRⅠ.After transfection of GDNF and sTMFRⅠgenes,many neural stem cells show GFAP and tubulin immunofluorescence positive staining,which meant that most neural stem cells differentiated into neuron at that condition.Conclusions:The infective efficiency of adenovirus is greatly acceptable to neural stem cell,thus adenovirus provide a useful vector for exogenous GDNF and sTMFRⅠgenes expressing in neural stem cells,which is useful for differentiation of neural stem cell.
文摘Hepatocellular carcinoma(HCC) is the most common primary malignancy of the liver. It is the second leading cause of cancer-related deaths worldwide, with a very poor prognosis. In the United States, there has been only minimal improvement in the prognosis for HCC patients over the past 15 years. Details of the molecular mechanisms and other mechanisms of HCC progression remain unclear. Consequently, there is an urgent need for better understanding of these mechanisms. HCC is often diagnosed at advanced stages, and most patients will therefore need systemic therapy, with sorafenib being the most common at the present time. However, sorafenib therapy only minimally enhances patient survival. This review provides a summary of some of the known mechanisms that either cause HCC or contribute to its progression. Included in this review are the roles of viral hepatitis, non-viral hepatitis, chronic alcohol intake, genetic predisposition and congenital abnormalities, toxic exposures, and autoimmune diseases of the liver. Well-established molecular mechanisms of HCC progression such as epithelial-mesenchymal transition, tumor-stromal interactions and the tumor microenvironment, cancer stem cells, and senescence bypass are also discussed. Additionally, we discuss the roles of circulating tumor cells,immunomodulation, and neural regulation as potential new mechanisms of HCC progression. A better understanding of these mechanisms could have implications for the development of novel and more effective therapeutic and prognostic strategies, which are critically needed.
