The availability of a well-characterized animal brain tumor model will play an important role in identifying treatments for human brain tumors. Wistar rats bearing 9L glioma cells can develop solid, well-circumcised t...The availability of a well-characterized animal brain tumor model will play an important role in identifying treatments for human brain tumors. Wistar rats bearing 9L glioma cells can develop solid, well-circumcised tumors, and may be a useful animal model for the evaluation of various therapeutic approaches for gliosarcomas. In this study, the 9L/Wistar rat glioma model was produced by intracerebral implantation of 9L^LUC glioma cells syngenic to Fischer 344 （F344） rats. Bioluminescence imaging showed that tumors progressively grew from day 7 to day 21 in 9L^LUC/F344 rats, and tumor regression was found in some 9L^LUC/Wistar rats. Hematoxylin-eosin staining verified that intracranial tumors were gliomas. Immunohistochemistry results demonstrated that no CD4- and CD8-positive cells were found in the syngeneic 9L^LUC/F344 model. However, many infiltrating CD4- and CD8-positive cells were observed within the tumors of the 9L^LUC/Wistar model. Our data suggests that compared with 9L/F344 rats, 9L glioma Wistar rats may not be suitable for evaluating brain glioma immunotherapies, even though the model induced an immune response and exhibited tumor regression.展开更多
Hypoxia is a typical feature of the tumor microenvironment,one of the most critical factors affecting cell behavior and tumor progression.However,the lack of tumor models able to precisely emulate natural brain tumor ...Hypoxia is a typical feature of the tumor microenvironment,one of the most critical factors affecting cell behavior and tumor progression.However,the lack of tumor models able to precisely emulate natural brain tumor tissue has impeded the study of the effects of hypoxia on the progression and growth of tumor cells.This study reports a three-dimensional(3D)brain tumor model obtained by encapsulating U87MG(U87)cells in a hydrogel containing type I collagen.It also documents the effect of various oxygen concentrations(1%,7%,and 21%)in the culture environment on U87 cell morphology,proliferation,viability,cell cycle,apoptosis rate,and migration.Finally,it compares two-dimensional(2D)and 3D cultures.For comparison purposes,cells cultured in flat culture dishes were used as the control(2D model).Cells cultured in the 3D model proliferated more slowly but had a higher apoptosis rate and proportion of cells in the resting phase(G0 phase)/gap I phase(G1 phase)than those cultured in the 2D model.Besides,the two models yielded significantly different cell morphologies.Finally,hypoxia(e.g.,1%O2)affected cell morphology,slowed cell growth,reduced cell viability,and increased the apoptosis rate in the 3D model.These results indicate that the constructed 3D model is effective for investigating the effects of biological and chemical factors on cell morphology and function,and can be more representative of the tumor microenvironment than 2D culture systems.The developed 3D glioblastoma tumor model is equally applicable to other studies in pharmacology and pathology.展开更多
The aggressive and invasive nature of brain tumors has hampered progress in the design and implementation of efficacious therapies. The recent success of targeted therapies in other tumor types makes this an attractiv...The aggressive and invasive nature of brain tumors has hampered progress in the design and implementation of efficacious therapies. The recent success of targeted therapies in other tumor types makes this an attractive area for research yet complicating matters is the ability of brain tumors to circumvent the targeted pathways to develop drug resistance. Effective therapies will likely need to target more than one signaling pathway or target multiple nodes within a given pathway. Key to identifying these targets is the elucidation of the driver and passenger molecules within these pathways. Animal models provide a useful tool with many advantages in the study of these pathways. These models provide a means to dissect the critical components of tumorigenesis, as well as serve as agents for preclinical testing. This review focuses on the use of the RCAS/tv-a mouse model of brain tumors and describes their unique ability to provide insight into the role of oncogene cooperation in tumor development and progression.展开更多
Background Treating intramedullary spinal cord gliomas is a big challenge because of limited options, high recurrence rate and poor prognosis. An intramedullary glioma model is prerequisite for testing new treatments....Background Treating intramedullary spinal cord gliomas is a big challenge because of limited options, high recurrence rate and poor prognosis. An intramedullary glioma model is prerequisite for testing new treatments. This paper describes the establishment of a rodent intramedullary glioma model and presents functional progression, neuroimaging and histopathological characterization of the tumour model. Methods Fischer344 rats （n=24） were randomized into two groups. Group 1 （n=16） received a 5 pl intramedullary implantation of 9L gliosarcomal （105） cells. Group 2 （n=8） received a 5 pl intramedullary injection of Dulbecco＇s modified Eagle medium. The rats were anesthetized, the spinous process of the T10 vertebra and the ligamentum flavum were removed to expose the T10-11 intervertebral space and an intramedullary injection was conducted into the spinal cord. The rats were evaluated preoperatively and daily postoperatively for neurological deficits using the Basso, Beattie and Bresnahan scale. High resolution magnetic resonance images were acquired preoperatively and weekly postoperatively. When score equal to 0, rats were sacrificed for histopathological examination. Results Rats implanted with 9L gliosarcoma cells had a statistically significant median onset of hind limb paraplegia at （16.0±0.4） days, compared with rats in the control group in which neurological deficits were absent. Imaging and pathological cross sections confirmed intramedullary 9L gliosarcoma invading the spinal cord. Rats in the control group showed no significant functional, radiological or histopathological findings of tumour. Conclusions Rats implanted with 9L cells regularly develop paraplegia in a reliable and reproducible manner. The progression of neurological deficits, neuroimaging and histopathological characteristics of intramedullary spinal cord gliomas in rats is comparable with the behaviour of infiltrative intramedullary spinal cord gliomas in patients.展开更多
This work presents an efficient method for volume rendering of glioma tumors from segmented 2D MRI Datasets with user interactive control, by replacing manual segmentation required in the state of art methods. The mos...This work presents an efficient method for volume rendering of glioma tumors from segmented 2D MRI Datasets with user interactive control, by replacing manual segmentation required in the state of art methods. The most common primary brain tumors are gliomas, evolving from the cerebral supportive cells. For clinical follow-up, the evaluation of the preoperative tumor volume is essential. Tumor portions were automatically segmented from 2D MR images using morphological filtering techniques. These segmented tumor slices were propagated and modeled with the software package. The 3D modeled tumor consists of gray level values of the original image with exact tumor boundary. Axial slices of FLAIR and T2 weighted images were used for extracting tumors. Volumetric assessment of tumor volume with manual segmentation of its outlines is a time-consuming process and is prone to error. These defects are overcome in this method. Authors verified the performance of our method on several sets of MRI scans. The 3D modeling was also done using segmented 2D slices with the help of medical software package called 3D DOCTOR for verification purposes. The results were validated with the ground truth models by the Radiologist.展开更多
Gliomas, the most aggressive form of brain cancer, are known for their widespread invasion into the tissue near the tumor lesion. Exponential models, which have been widely used in other types of cancers, cannot be us...Gliomas, the most aggressive form of brain cancer, are known for their widespread invasion into the tissue near the tumor lesion. Exponential models, which have been widely used in other types of cancers, cannot be used for the simulation of tumor growth, due to the diffusive behavior of glioma. Diffusive models that have been proposed in the last two decades seem to better approximate the expansion of gliomas. This paper covers the history of glioma diffusive modelling, starting from the simplified initial model in 90s and describing how this have been enriched to take into account heterogenous brain tissue, anisotropic migration of glioma cells and adjustable proliferation rates. Especially, adjustable proliferation rates are very important for modelling therapy plans and personalising therapy to different patients.展开更多
Glioma incidence rates in the United States are near 20000 new cases per year, with a median survival time of 14.6 mo for high-grade gliomas due to limited therapeutic options. The origins of these tumors and their ma...Glioma incidence rates in the United States are near 20000 new cases per year, with a median survival time of 14.6 mo for high-grade gliomas due to limited therapeutic options. The origins of these tumors and their many subtypes remain a matter of investigation. Evidence from mouse models of glioma and human clinical data have provided clues about the cell types and initiating oncogenic mutations that drive gliomagenesis, a topic we review here. There has been mixed evidence as to whether or not the cells of origin are neural stem cells, progenitor cells or differentiated progeny. Many of the existing murine models target cell populations defined by lineage-specific promoters or employ lineagetracing methods to track the potential cells of origin. Our ability to target specific cell populations will likely increase concurrently with the knowledge gleaned from an understanding of neurogenesis in the adult brain. The cell of origin is one variable in tumorigenesis, as oncogenes or tumor suppressor genes may differentially transform the neuroglial cell types. Knowledge of key driver mutations and susceptible cell types will allow us to understand cancer biology from a developmental standpoint and enable early interventional strategies and biomarker discovery.展开更多
Background: This paper describes the establishment of a rat intramedullary spinal cord tumor (IMSCT) model and histopathological characterization of the tumor model. Methods: Fourteen male Wistar rats were randomized ...Background: This paper describes the establishment of a rat intramedullary spinal cord tumor (IMSCT) model and histopathological characterization of the tumor model. Methods: Fourteen male Wistar rats were randomized into two groups. The rats in group 1 (control group, n = 7) received a 5 μl intramedullary injection of serum physiologic (SF). Those in group 2 (experimental group, n= 7) received a 5 μl intramedullary implantation of media containing 5 × 105 C6 glioma cells. The animals were sacrificed for histopathological examination at 21 days. Results: The control group showed normal functional and histopathological findings. The group 2 rats implanted with C6 glioblastoma cells developed hind-limb paraplegia. Pathological sections confirmed intramedullary C6 glioblastoma invading the spinal cord. Conclusions: A rat C6 IMSCT model was successfully established. This model may be useful in increasing understanding of intramedullary spinal cord gliomas in humans.展开更多
文摘The availability of a well-characterized animal brain tumor model will play an important role in identifying treatments for human brain tumors. Wistar rats bearing 9L glioma cells can develop solid, well-circumcised tumors, and may be a useful animal model for the evaluation of various therapeutic approaches for gliosarcomas. In this study, the 9L/Wistar rat glioma model was produced by intracerebral implantation of 9L^LUC glioma cells syngenic to Fischer 344 （F344） rats. Bioluminescence imaging showed that tumors progressively grew from day 7 to day 21 in 9L^LUC/F344 rats, and tumor regression was found in some 9L^LUC/Wistar rats. Hematoxylin-eosin staining verified that intracranial tumors were gliomas. Immunohistochemistry results demonstrated that no CD4- and CD8-positive cells were found in the syngeneic 9L^LUC/F344 model. However, many infiltrating CD4- and CD8-positive cells were observed within the tumors of the 9L^LUC/Wistar model. Our data suggests that compared with 9L/F344 rats, 9L glioma Wistar rats may not be suitable for evaluating brain glioma immunotherapies, even though the model induced an immune response and exhibited tumor regression.
基金supported by the National Natural Science Foundation of China (No. 52275291)the Fundamental Research Funds for the Central Universitiesthe Program for Innovation Team of Shaanxi Province,China (No. 2023-CX-TD-17)
文摘Hypoxia is a typical feature of the tumor microenvironment,one of the most critical factors affecting cell behavior and tumor progression.However,the lack of tumor models able to precisely emulate natural brain tumor tissue has impeded the study of the effects of hypoxia on the progression and growth of tumor cells.This study reports a three-dimensional(3D)brain tumor model obtained by encapsulating U87MG(U87)cells in a hydrogel containing type I collagen.It also documents the effect of various oxygen concentrations(1%,7%,and 21%)in the culture environment on U87 cell morphology,proliferation,viability,cell cycle,apoptosis rate,and migration.Finally,it compares two-dimensional(2D)and 3D cultures.For comparison purposes,cells cultured in flat culture dishes were used as the control(2D model).Cells cultured in the 3D model proliferated more slowly but had a higher apoptosis rate and proportion of cells in the resting phase(G0 phase)/gap I phase(G1 phase)than those cultured in the 2D model.Besides,the two models yielded significantly different cell morphologies.Finally,hypoxia(e.g.,1%O2)affected cell morphology,slowed cell growth,reduced cell viability,and increased the apoptosis rate in the 3D model.These results indicate that the constructed 3D model is effective for investigating the effects of biological and chemical factors on cell morphology and function,and can be more representative of the tumor microenvironment than 2D culture systems.The developed 3D glioblastoma tumor model is equally applicable to other studies in pharmacology and pathology.
基金the National Institutes of Health(NIH),the Texas Higher Education Coordination Board,and the Goldhirsh Foundation for supporting our research using the RCAS mouse modelLynette Mooreis supported by an American Cancer Society Postdoctoral FellowshipKristen Holmes is supportedby the NIH Pharmacoinformatic Training Grantfellow ship
文摘The aggressive and invasive nature of brain tumors has hampered progress in the design and implementation of efficacious therapies. The recent success of targeted therapies in other tumor types makes this an attractive area for research yet complicating matters is the ability of brain tumors to circumvent the targeted pathways to develop drug resistance. Effective therapies will likely need to target more than one signaling pathway or target multiple nodes within a given pathway. Key to identifying these targets is the elucidation of the driver and passenger molecules within these pathways. Animal models provide a useful tool with many advantages in the study of these pathways. These models provide a means to dissect the critical components of tumorigenesis, as well as serve as agents for preclinical testing. This review focuses on the use of the RCAS/tv-a mouse model of brain tumors and describes their unique ability to provide insight into the role of oncogene cooperation in tumor development and progression.
文摘Background Treating intramedullary spinal cord gliomas is a big challenge because of limited options, high recurrence rate and poor prognosis. An intramedullary glioma model is prerequisite for testing new treatments. This paper describes the establishment of a rodent intramedullary glioma model and presents functional progression, neuroimaging and histopathological characterization of the tumour model. Methods Fischer344 rats （n=24） were randomized into two groups. Group 1 （n=16） received a 5 pl intramedullary implantation of 9L gliosarcomal （105） cells. Group 2 （n=8） received a 5 pl intramedullary injection of Dulbecco＇s modified Eagle medium. The rats were anesthetized, the spinous process of the T10 vertebra and the ligamentum flavum were removed to expose the T10-11 intervertebral space and an intramedullary injection was conducted into the spinal cord. The rats were evaluated preoperatively and daily postoperatively for neurological deficits using the Basso, Beattie and Bresnahan scale. High resolution magnetic resonance images were acquired preoperatively and weekly postoperatively. When score equal to 0, rats were sacrificed for histopathological examination. Results Rats implanted with 9L gliosarcoma cells had a statistically significant median onset of hind limb paraplegia at （16.0±0.4） days, compared with rats in the control group in which neurological deficits were absent. Imaging and pathological cross sections confirmed intramedullary 9L gliosarcoma invading the spinal cord. Rats in the control group showed no significant functional, radiological or histopathological findings of tumour. Conclusions Rats implanted with 9L cells regularly develop paraplegia in a reliable and reproducible manner. The progression of neurological deficits, neuroimaging and histopathological characteristics of intramedullary spinal cord gliomas in rats is comparable with the behaviour of infiltrative intramedullary spinal cord gliomas in patients.
文摘This work presents an efficient method for volume rendering of glioma tumors from segmented 2D MRI Datasets with user interactive control, by replacing manual segmentation required in the state of art methods. The most common primary brain tumors are gliomas, evolving from the cerebral supportive cells. For clinical follow-up, the evaluation of the preoperative tumor volume is essential. Tumor portions were automatically segmented from 2D MR images using morphological filtering techniques. These segmented tumor slices were propagated and modeled with the software package. The 3D modeled tumor consists of gray level values of the original image with exact tumor boundary. Axial slices of FLAIR and T2 weighted images were used for extracting tumors. Volumetric assessment of tumor volume with manual segmentation of its outlines is a time-consuming process and is prone to error. These defects are overcome in this method. Authors verified the performance of our method on several sets of MRI scans. The 3D modeling was also done using segmented 2D slices with the help of medical software package called 3D DOCTOR for verification purposes. The results were validated with the ground truth models by the Radiologist.
文摘Gliomas, the most aggressive form of brain cancer, are known for their widespread invasion into the tissue near the tumor lesion. Exponential models, which have been widely used in other types of cancers, cannot be used for the simulation of tumor growth, due to the diffusive behavior of glioma. Diffusive models that have been proposed in the last two decades seem to better approximate the expansion of gliomas. This paper covers the history of glioma diffusive modelling, starting from the simplified initial model in 90s and describing how this have been enriched to take into account heterogenous brain tissue, anisotropic migration of glioma cells and adjustable proliferation rates. Especially, adjustable proliferation rates are very important for modelling therapy plans and personalising therapy to different patients.
基金Supported by The Medical Scientist Training Program at NYU School of Medicine to Modrek ASNYSTEM Institutional training grant#CO26880 to Bayin NS+1 种基金NIH/NINDS(1 R21 NS087241-01)the NYU Cancer Institute Developmental Projects Program and the NYU Clinical and Translational Science Institute(NYU CTSA grant#UL1TR000038 from the National Center for the Advancement of Translational Science NCATS,NIH)to Placantonakis DG
文摘Glioma incidence rates in the United States are near 20000 new cases per year, with a median survival time of 14.6 mo for high-grade gliomas due to limited therapeutic options. The origins of these tumors and their many subtypes remain a matter of investigation. Evidence from mouse models of glioma and human clinical data have provided clues about the cell types and initiating oncogenic mutations that drive gliomagenesis, a topic we review here. There has been mixed evidence as to whether or not the cells of origin are neural stem cells, progenitor cells or differentiated progeny. Many of the existing murine models target cell populations defined by lineage-specific promoters or employ lineagetracing methods to track the potential cells of origin. Our ability to target specific cell populations will likely increase concurrently with the knowledge gleaned from an understanding of neurogenesis in the adult brain. The cell of origin is one variable in tumorigenesis, as oncogenes or tumor suppressor genes may differentially transform the neuroglial cell types. Knowledge of key driver mutations and susceptible cell types will allow us to understand cancer biology from a developmental standpoint and enable early interventional strategies and biomarker discovery.
文摘Background: This paper describes the establishment of a rat intramedullary spinal cord tumor (IMSCT) model and histopathological characterization of the tumor model. Methods: Fourteen male Wistar rats were randomized into two groups. The rats in group 1 (control group, n = 7) received a 5 μl intramedullary injection of serum physiologic (SF). Those in group 2 (experimental group, n= 7) received a 5 μl intramedullary implantation of media containing 5 × 105 C6 glioma cells. The animals were sacrificed for histopathological examination at 21 days. Results: The control group showed normal functional and histopathological findings. The group 2 rats implanted with C6 glioblastoma cells developed hind-limb paraplegia. Pathological sections confirmed intramedullary C6 glioblastoma invading the spinal cord. Conclusions: A rat C6 IMSCT model was successfully established. This model may be useful in increasing understanding of intramedullary spinal cord gliomas in humans.
