Dear Wayne,
I am writing this note to inform you of recent development in my research activity.
(1) I agreed to provide the HB1.F3 human neural stem cell line and its sub lines to
Evan Snyder to be implanted in the brain of monkey Parkinson disease (PD) models. Dr. Eugene Redmond of Yale and Dr. Ted Teng of Harvard at
the Primate Center in St Kitts will conduct the brain transplantation. In addition to F3 parental cell line, F3.LacZ and F3.eGFP (both cell lines carry cell-specific tags so that one can identify grafted cells in the animal brain), F3.TH.GTP (this cell line makes L-DOPA 2000 times over parental F3 cells; L-DOPA is a precursor molecule of dopamine which is short supply in PD patients' brain), F3.GDNF (GDNF is a neurotrophic factor well known to protect host neurons in PD patient's brain) and F3.Nurr1 (Nurr1 is a master gene to induce dopaminergic neurons). I have already sent F3, F3.LacZ and F3.eGFP cell lines to Snyder. In the month of October, I will provide him with F3.TH.GTP, F3.GDNF and F3.Nurr1 cell lines to be propagated and implanted in PD monkeys.
(2) Dr. Karen Aboody (
City of Hope Medical Center -One of the most active cancer hospital in the world located outside of Los Angeles) and
Dr. Peter Black (Chief of Neurosurgery at the Brigham and Women’s Hospital-Harvard and one of the top brain tumour specialists) are currently using F3.CD (cytosine deaminase,
a suicide gene) cell line we previously developed for brain tumour treatment. F3 human NSC showed extensive migratory and tumour-tropic properties, and could be used for treatment of invasive brain tumours. Intracranial injection of human F3.CD Neural Stem Cells (NSCs) carrying a suicide gene cytosine deaminase (CD) resulted in a significant anti-tumour response in rat glioma models. Moreover, intravascularly delivered human NSCs used to target human primary and metastatic tumours in animal models of neuroblastoma and breast cancer show promise. Dr. Mary Danks of St Jude Children's Medical Center in Memphis USA, is conducting a neuroblastoma study and
Dr. Carlotta Glackin of the City of Hope Medical Center is performing a breast cancer.
(3) We will concentrate our research effort during the next 6 months to develop sub lines of the new human NSC cell line, HB2.G2. We generated this new cell line by the use of Tet-on-v-myc system. We required a v-myc oncogene to produce our human neural stem cell line F3, and so there is a risk of these cells developing a brain tumour once transplanted into a patients' brain. For that reason, we used the Tet-on-v-myc system by which activates v-myc only in the presence of tetracycline. In the absence of tetracycline, NSCs will not increase in number but differentiate into neurons. We have already generated sub lines of G2 including G2.eGFP, G2.LacZ and G2.BDNF (G2.BDNF was grafted into rat model of stroke and improved clinical outcome markedly).
(4) We have generated a new human bone marrow
mesenchymal stem cell lines using a retoroviral vector carrying v-myc, and we have successfully produced bone, cartilage, fat cells and neurons from these bone marrow stem cells. We will collaborate with other investigators to develop pancreatic insulin producers, heart muscle cells and liver parenchymal cells from these human bone marrow stem cells.
The following is an abstract of my presentation at the Annual meeting of the Japanese Neuropathology Society in Nagoya in May 2004:
IMMORTALIZED HUMAN NEURAL STEM CELL LINE GENETICALLY MODIFIED FOR BRAIN REPAIR
Seung Up Kim, MD, PhD
Brain Disease Research Center, Ajou University School of Medicine, Suwon, Korea; Department of Neurology, University of British Columbia, Vancouver, Canada
Cell replacement and gene transfer to the diseased or injured CNS have provided the basis for the development of potentially powerful new therapeutic strategies for a broad spectrum of human neurological diseases including Parkinson disease (PD), Huntington disease (HD), amyotrophic lateral sclerosis (ALS), Alzheimer disease (AD), stroke and spinal cord injury. In PD and HD, previous studies have documented improvements in motor and cognition performance in patients following fetal human brain cell transplantation. However, ethical, religious and logistic difficulties associated with the use of fetal tissues limit wide adoption of this approach. An ideal source of cell therapy in neurological diseases is human neural stem cells (NSCs) that could integrate into host brain tissue and differentiate into neurons or glial cells in response to environmental cues. Successful application of in vivo gene transfer to the CNS will depend on the identification of suitable cells that can serve as carriers for a wide range of potentially therapeutic transgenes and provide platforms for functionally efficient expression and secretion of transgene products. Immortalized NSCs have recently been introduced as potentially interesting candidates for this purpose.
We have previously generated stable cell lines of human NSCs from primary cultures of human fetal telencephalon via transfection with a retroviral vector encoding v-myc oncogene. One of the cell lines, HB1.F3, expresses nestin and ABCG2, both cell type-specific markers for neural stem cells and normal human karyotype of 46XX without any chromosomal abnormality. F3 NSC cell line has the ability to self-renew, differentiate into cells of neuronal and glail lineage (Cho et al., Neuroreport 13, 1447, 01), and integrate into the damaged CNS loci upon transplantation into the brain of animal models of stroke (Jeong et al., Stroke 34, 2258, 03; Chu et al., Brain Res 1016, 145, 04), HD (Ryu et al., Neurobiol Disease 16, 145, 04) and lysosomal storage disease (Meng et al., J Neurosci Res 74, 266, 03).
In animal models of PD, F3 NSC cell line was transduced to carry tyrosine hydroxylase (TH) and GTP cyclohydrolase I (GTPCHI), via retrovirally mediated procedures. HPLC analysis indicated that the level of L-DOPA produced by the F3.TH.GTP is 62 ng/hr/106 cells, a 2000-fold increase over parental F3 cell line. L-DOPA producing NSCs were transplanted into the striatum of PD rats to replace missing dopaminergic neurons, and the results indicated that there was a marked improvement in amphetamine-induced turning behavior and a good survival of TH-positive cells in the PD animals.
Human NSCs generated by us showed extensive migratory and tumor-tropic properties, and was used for the treatment of invasive tumors. NSCs meet two major challenges facing current gene therapy strategies: effective delivery and distribution of a therapeutic agent throughout the tumor masses. Recently we have demonstrated that the intracranial injection of human F3.CD NSCs carrying a suicide gene, cytosine deaminase (CD) resulted in a significant anti-tumor response in rat glioma models. In addition, intravascularly delivered human NSCs targeting human primary and metastatic tumors in animal models of neuroblastoma and breast cancer showed promise.
The results of the present study have particular relevance to cell therapy in neurodegenerative diseases including PD, HD, ALS and AD and also for stroke and spinal cord injury. NSC transplantation has the great potential to prevent or restore anatomic or functional deficits associated with CNS injury or disease via cell replacement, release of specific neurotransmitters, and production of molecules that promote neuronal growth and regeneration.
Grants from KOSEF/ BDRC-Ajou University and Canadian Myelin Research Initiative supported this research.
Regards, Seung Kim, MD
posted by Canadian Myelin Research Initiative at 10:26 PM
