Matrigel growth

Matrigel (growth factor reduced), Becton Dickinson. 

Rotating culture vessels such as simulated microgravity systems are primarily used to study 3-D tumor growth and differentiation. However, mixed cell populations combined with matrix proteins can be used to generate a complex microenvironment in which cell-cell interactions and invasion can be measured (95). A similar system has also been described for the coculture of endothelial cells, myofibroblasts, and tumor cell clusters embedded in Matrigel . Differential labeling of the cell populations enables their invasion and the effects of inhibitors to be measured (96). 

To prevent cell leakage, allow the needle to remain in the injection site for approximately 5-10 s after cell implantation, and then slowly remove the needle. This should prevent cell leakage, allow the Matrigel to harden, and minimize inconsistency in tumor growth. 

Vukicevic, S. et al. 1992. Identification of multiple active growth factors in basement membrane Matrigel suggests caution in interpretation of cellular activity related to extracellular activity related to extracellular matrix components. Exp. Cell Res. 202, 1-8. 

It is interesting to note that from co-injection experiments with Matrigel , it has emerged that the cooperative effects of host fibroblasts is exerted not only through direct secretion of growth factors, but also by release of proteases that can liberate growth factors adsorbed to the extracellular matrix, making them available to the cancer cells (Noel et al., 1998). 

A simple variation on the method described above was used by Tullberg et al. (1989) to select B16 melanoma cells of increased invasive (and metastatic) ability. Filters with pores of 10 /.tm are employed to avoid a selection for pore penetration, and coated with a thick layer (approximately 1 fim) of Matrigel , a reconstituted BM derived from EHS tumors (see Chapter 4 for more details). Cells are plated on the coated filters at a density that is lower than that used for the migration selection, since in this case the time it takes for the cells to migrate can be considerably higher, and excessive growth on the upper side of the filter has to be prevented. Optimal conditions have to be empirically determined for each cell line. Cells that have invaded and passed to the underside of the filter are collected and expanded as described above, and further selections can be made to obtain a fairly homogenous cell population of increased invasive potential, from which clones can be derived. 

Fridman, R., Kibbey, M. C., Royce, L. S., Zain, M., Sweeney M, Jicha, D. L., Yannelli, J. R., Martin, G. R. and Kleinman, H. K. (1991). Enhanced tumor growth of both primary and established human and murine tumor cells in athymic mice after coinjection with matrigel. J. Natl. Cancer Inst. 83,769-774. 

Taub, M., Wang, Y, Szczesny, T. M. and Kleinman, H. K. (1990). Epidermal growth factor or transforming growth factor a is required for kidney tubuloge-nesis in matrigel cultures in serum-free medium. Proc. Natl. Acad. Sci. USA 87,4002-4006. 

Table 2. Effects of royal jelly on die weight and hemoglobin content of the gels 5 days after implantation into mice of Matrigel supplemented with acidic fibroblast growth factor (aFGF) and heparin...

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