By Donald Zuhn --
On Monday, Neuralstem, Inc. announced that the U.S. Patent and Trademark Office allowed U.S. Application No. 10/047,352 (U.S. Patent Publication No. 2002/0064873), entitled "Stable neural stem cell lines." The '352 application, which was allowed on January 13th, is directed to a method for establishing stable neural stem cell lines and neuronal progenitor lines. The timing of the '352 application's allowance is interesting in view of the recent announcement that the FDA has approved of Geron's Investigational New Drug (IND) application for the clinical trial of that company's human embryonic stem cell (hESC)-based therapeutic candidate in patients with acute spinal cord injury (see "Geron Gets Approval for First Human Clinical Trial Using Embryonic Stem Cells").
According to Neuralstem's press release, the patent issuing from the '352 application will cover methods of immortalizing any human neural stem cell using c-Myc-ER, a fusion protein of c-Myc and estrogen receptor (ER). The immortalized human neural stem cells can be grown for over 60 cell doublings. The claimed methods will allow for the production of commercial quantities of neural stem cells of the human brain and spinal cord, which can then be differentiated into human neurons and glia (a video of Neuralstem's process can be viewed here). Stable neural stem cells produced by the claimed methods can be used to treat diseases of the major central nervous system, including ischemic spastic paraplegia, traumatic spinal cord injury, Huntington's disease, and amyotrophic lateral sclerosis (ALS). In December, Neuralstem filed an IND application for ALS clinical trials using its stable neural stem cells, after showing in preclinical studies that the cells extended the life of rats with ALS.
The '352 application, which upon issuance will be Neuralstem's third U.S. patent, is a continuation of U.S. Application No. 09/398,897, which claims the benefit of U.S. Provisional Application No. 60/101,354 and is a continuation-in-part of U.S. Application No. 09/053,414, which is a continuation-in-part of U.S. Application No. 08/719,450, which issued as U.S. Patent No. 5,753,506. Independent claims 51 and 64 of the '352 application (which will issue as claims 1 and 13) recite:
a) culturing at least one neural precursor cell in a medium including a first mitogen selected from the group consisting of aFGF, bFGF, EGF, TGFα and combinations thereof;
b) introducing into the neural precursor cell in the medium including the first mitogen a recombinant DNA construct comprising a receptor ligand-regulated c-myc cDNA, wherein c-myc cDNA is fused with DNA encoding a ligand-binding domain of a nuclear receptor; and
c) expanding the neural precursor cell including the c-myc construct beyond thirty cell doublings prior to differentiation of said cell, wherein said expansion occurs in a medium containing the first mitogen and a second mitogen,
wherein said second mitogen is selected from the group consisting of aFGF, bFGF, EGF, TGFα, serum and combinations thereof, and
wherein said medium comprising the first mitogen and the second mitogen further comprises an amount of a c-myc-activating agent sufficient to maintain a stable cell line, wherein said c-myc-activating agent is capable of binding to the ligand-binding domain of said nuclear receptor.
64: A method of maintaining the capacity of a neural precursor cell line of a human to differentiate into neurons in vitro, wherein said cell line includes neural precursor cells capable of differentiating into neurons and glia, said method comprising:
a) preparing a culture comprising at least one neural precursor cell from said neural precursor cell line, wherein said culture includes at least one mitogen selected from the group consisting of aFGF, bFGF, EGF, TGFα and combinations thereof;
b) introducing into said neural precursor cell a recombinant DNA construct comprising a receptor ligand-regulated c-myc cDNA capable of expressing a chimeric c-myc protein fused with at least one nuclear receptor protein having a c-myc-activating ligand binding domain; and
c) expanding the undifferentiated modified neural precursor cell beyond thirty cell doublings in a medium comprising said mitogen and an amount of a c-myc-activating agent.
How to applie, as an ALS patient?
Posted by: i.r. | March 11, 2009 at 04:19 PM