Available Technology
Immortalized drug-resistant cell line for propogating hES cells
Markets Addressed
Numerous research laboratories and companies throughout the world are targeting hES cells as sources of human cells for regenerative medicine to treat a variety of diseases from coronary ischemia to diabetes to spinal cord regeneration, and are utilizing hES cells to study processes of biological differentiation. This field of endeavor is exploding rapidly as the technical barriers are being overcome.
Although various chemically defined media for growing hES are being evaluated, the most efficient and viable way to culture hES cells such that they remain pluripotent is utilizing feeder cells. Cells used most commonly are mouse embryo fibroblast (“MEF”) cells. Disadvantages with MEF cells, however, are that hES cells are difficult or impossible to maintain in the pluripotent state, difficult to grow, and -- since MEF cells are not immortal -- the cells tend to be variable and remain poorly characterized. Similar issues have been reported with feeder cell lines of human origin.
Because of the robust and immortal nature of the MMM cell line, quality control studies that require culture reproducibility are feasible which will potentially pave the way for use in human subjects. In addition, the research market for feeders that can support pluripotent hES cells is significant.
Innovations and Advantages
Dr. Howard Green is world renowned for having developed the first use of cultured cells as therapeutics - keratinocytes for the regeneration of epidermis on severely burned patients. Recently, Dr. Green’s group has developed an immortalized cell line, known as MMM, which grows robustly and efficiently supports propagation of hES cells in culture.
The MMM line is a unique cell line derived from fibroblasts of 12-13 day old mouse embryos. After 24 serial subcultures, the line became established (immortalized). It is robust and grows very rapidly (Td=16 hours). It is very effective in supporting the growth of human embryonic stem (hES) cells. The MMM line has been made resistant to blasticidin and zeocin, which are the most efficient drugs available for selection of hES cells transfected with exogenous genes.
MMM cells were found to be superior to the commonly used MEFs for the maintenance of stem cell character of the hES line H9 when cocultivated (Iuchi et al., Differentiation, 74: 160, 2006). In addition, the hES line known as H1, which is very difficult to grow on MEFs, has been demonstrated to be serially cultivatable on MMM cells. The H1 cells are able to grow very well, and retain the stem cell property of pluripotentiality, as shown by the retention of nuclear Oct4 (Photo 1). The well-circumscribed borders of these colonies can also be seen by Differential Interference Contrast Microscopy (Photo 2).
The significant advantages of MMM cells for support of hES cells include –
• Indefinite lifespan (immortalized);
• Rapid growth rate;
• Better support of hES cells than MEFs;
• Excellent ability to support growth of difficult-to-grow hES lines, with maintenance of the pluripotential state;
• Their resistance to blasticidin and zeocin makes it possible to select, by drug treatment, for hES cells into which exogenous genes have been introduced, without killing the supporting MMM
Additional Information
Intellectual Property Status: Issued U.S. patent nos.: 7,413,900
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Inventor(s):
Green, Howard
Iuchi, Shiro
Kuri-Harcuch, Walid
Marsch-Moreno, Meytha
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For further information, please contact:
Grant Zimmermann, Director of Business Development
(617) 495-3067
Reference Harvard Case #2550