Chemically defined medium for the culture of cancer stem cell (CSC) containing cell populations

1. A chemically defined medium for 3D tumorsphere culture, comprising water, at least one carbon source, one or more vitamins, one or more salts, one or more fatty acids, one or more buffer components, and trace elements:

aluminum (Al), in a concentration in a range of 1.5 nM to 15 nM;

barium (Ba), in a concentration in a range of 1.5 nM to 15 nM;

bromine (Br), in a concentration in a range of 0.4 nM to 4 nM;

cadmium (Cd), in a concentration in a range of 4 nM to 40 nM;

cobalt (Co), in a concentration in a range of 1 nM to 10 nM;

chromium (Cr), in a concentration in a range of 0.5 nM to 5 nM;

germanium (Ge), in a concentration in a range of 2 nM to 20 nM;

iodine (I), in a concentration in a range of 0.25 nM to 2.5 nM;

fluorine (F), in a concentration in a range of 12 nM to 120 nM;

nickel (Ni), in a concentration in a range of 0.2 nM to 2 nM;

manganese (Mn), in a concentration in a range of 0.1 nM to 1 nM;

molybdenum (Mo), in a concentration in a range of 0.7 nM to 7 nM;

rubidium (Rb), in a concentration in a range of 4 nM to 40 nM;

selenium (Se) in a concentration in a range of 40 nM to 400 nM;

silver (Ag), in a concentration in a range of 0.3 nM to 3 nM;

silicon (Si), in a concentration in a range of 130 nM to 1.3 μM;

tin (Sn), in a concentration in a range of 0.1 nM to 1 nM;

vanadium (V), in a concentration in a range of 2 nM to 22 nM; and

zirconium (Zr), in a concentration in a range of 3.5 nM to 35 nM,

wherein the medium is serum-free.

2. The chemically defined cell culture medium of claim 1 , wherein the chemically defined cell culture medium does not comprise any growth factor.

3. The chemically defined cell culture medium of claim 1 , comprising one or more growth factors.

4. The chemically defined medium according to claim 3 , wherein the one or more growth factors are selected from the group consisting of epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), transforming growth factor (TGF), interleukin 6 (IL-6), interleukin 8 (IL-8), and leukemia inhibitory factor (LIF).

5. The chemically defined medium according to claim 4 , wherein the chemically defined cell culture medium comprises EGF and bFGF.

6. The chemically defined medium according to claim 1 , wherein the one or more fatty acids are selected from the group consisting of arachidonic acid, linolenic acid, linoleic acid, oleic acid, myristic acid, palmitic acid, and stearic acid, each in a concentration sufficient to support cancer stem cell proliferation and/or maintenance.

7. The chemically defined medium according to claim 6 , comprising at least two of the fatty acids.

8. The chemically defined medium according to claim 7 , comprising at least three of the fatty acids.

9. The chemically defined medium according to claim 1 , further comprising at least one surfactant.

10. The chemically defined medium according to claim 9 , comprising two nonionic surfactants polysorbate 80 and Poloxamer 188.

11. The chemically defined medium according to claim 9 , wherein the surfactant is a nonionic surfactant selected from the group consisting of polysorbates and Poloxamer 188.

12. The chemically defined medium according to claim 1 , further comprising insulin, transferrin, and/or albumin, each in a concentration sufficient to support cancer stem cell proliferation and/or maintenance.

13. The chemically defined medium according to claim 1 , wherein the buffer components are selected from the group consisting of HEPES, inorganic bicarbonate, inorganic phosphate, and 3-(N-Morpholino)propanesulfonic acid (MOPS).

14. The chemically defined medium according to claim 1 , comprising at least three buffer components.

15. The chemically defined medium according to claim 1 , further comprising cholesterol and/or tocopherol acetate.

16. A method of culturing cancer stem cells, comprising culturing cancer stem cells in the chemically defined medium according to claim 1 .

17. The method according to claim 16 , wherein the culturing of cancer stem cells is performed as 3D suspension culture.

18. A cell culture system, comprising cancer cells, in particular cancer stem cells, and a chemically defined medium according to claim 1 .